WorldWideScience

Sample records for activity current hypotheses

  1. The Etiology and Pathogenesis of Chronic Rhinosinusitis: a Review of Current Hypotheses.

    Lam, Kent; Schleimer, Robert; Kern, Robert C

    2015-07-01

    Chronic rhinosinusitis (CRS) is a broad clinical syndrome that is characterized by prolonged mucosal inflammation of the nose and paranasal sinuses, and is typically divided into two subtypes based on the presence or absence of nasal polyps. The etiology and pathogenesis of both forms remain areas of active research. Over the last 15 years, a number of hypotheses have been proposed to explain all or part of the clinical CRS spectrum. These hypotheses reflect the concept that CRS results from a dysfunctional interplay between individual host characteristics and factors exogenous to the host. Six broad theories on CRS etiology and pathogenesis are discussed as follows: (1) the "fungal hypothesis," (2) the "superantigen hypothesis," (3) the "biofilm hypothesis," and (4) the "microbiome hypothesis," all of which emphasize key environmental factors, and (5) the "eicosanoid hypothesis" and (6) the "immune barrier hypothesis," which describe specific host factors. These theories are reviewed, and the evidence supporting them is critically appraised. PMID:26143392

  2. Current UNSCEAR Activities

    UNSCEAR stands for United Nation Scientific Committee of Effects of Atomic Radiation. It has been in service for 55 years. It reports to the General Assembly. Its role is to assess global levels and effects of ionizing radiation and to provide scientific basis UNSCEAR in Africa: Egypt joined UNSCEAR in 1955 while Sudan joined in 1973. UNSCEAR in IRPA-11: Norman Gentner (Canada), the Scientific Secretary from 2001- 2005 gave a presentation about UNSCEAR. It was in Madrid, Spain 2004 UNSCEAR in second IRPA Africa’S Congress: This was in Egypt 2007. Abel Gonzalez (Argentina) who is a Member of UNSCEAR gave two presentations. i.e. a refresher course (UNSCEAR ) and a general lecture about UNSCEAR activities UNSCEAR in IRPA-12: Was held in 2008 and Malcolm Crick (UNSCEAR Scientific secretary) from 2005 gave a lecture entitled „Epistemology of radiation protection status of levels and effects of ionizing radiation.. UNSCEAR at IRPA Egypt workshop was held in Egypt January 2010 and Gomaa presented Malcolm Crick lecture to IRPA-12 to the participants of IRPA Egypt workshop January 2010. UNSCEAR Latest publications: Among the publications are:- UNSCEAR 2006 Report: Effects of ionizing radiation” 5 UNSCEAR 2008 Report: Sources and effects of ionizing radiation”. The 57 Session of UNSCEAR activities: a. The activities included reporting to the General Assembly on three levels. Part -1: Report on session deliberations Part-2: Scientific Report: Summary of low-dose radiation effects on health Part-3: Response to paragraph 13 of resolution 64/85 b. There were also discussions on some documents which included: -Assessment of levels of radiation from electrical energy production -Uncertainty in radiation risk estimation - Health effects attributable to radiation exposure -Methodology for estimating exposures due to discharges -Summary of radiation effects on health -Improving data collection, analysis and dissemination At the end of the lecture, there was an invitation for

  3. Sex, drugs, and rock 'n' roll: hypothesizing common mesolimbic activation as a function of reward gene polymorphisms.

    Blum, Kenneth; Werner, Tonia; Carnes, Stefanie; Carnes, Patrick; Bowirrat, Abdalla; Giordano, John; Oscar-Berman, Marlene; Gold, Mark

    2012-01-01

    The nucleus accumbens, a site within the ventral striatum, plays a prominent role in mediating the reinforcing effects of drugs of abuse, food, sex, and other addictions. Indeed, it is generally believed that this structure mandates motivated behaviors such as eating, drinking, and sexual activity, which are elicited by natural rewards and other strong incentive stimuli. This article focuses on sex addiction, but we hypothesize that there is a common underlying mechanism of action for the powerful effects that all addictions have on human motivation. That is, biological drives may have common molecular genetic antecedents, which if impaired, lead to aberrant behaviors. Based on abundant scientific support, we further hypothesize that dopaminergic genes, and possibly other candidate neurotransmitter-related gene polymorphisms, affect both hedonic and anhedonic behavioral outcomes. Genotyping studies already have linked gene polymorphic associations with alcohol and drug addictions and obesity, and we anticipate that future genotyping studies of sex addicts will provide evidence for polymorphic associations with specific clustering of sexual typologies based on clinical instrument assessments. We recommend that scientists and clinicians embark on research coupling the use of neuroimaging tools with dopaminergic agonistic agents to target specific gene polymorphisms systematically for normalizing hyper- or hypo-sexual behaviors. PMID:22641964

  4. Multiple Hypotheses Video OCR

    Chen, Datong; Luettin, Juergen

    2000-01-01

    In this paper, we present a method to improve video OCR with multiple character hypotheses. The text regions in video need to be binarized before work as the input of current OCR system. Tranditional binarization do not use any structural information about the text. Based on a certain statistic model, we define a binarization method, which is called observation function, that should satisfy a certain condition. We then present a method to construct an observation function by computing binariz...

  5. Perceptions as Hypotheses

    Gregory, R. L.

    1980-07-01

    Perceptions may be compared with hypotheses in science. The methods of acquiring scientific knowledge provide a working paradigm for investigating processes of perception. Much as the information channels of instruments, such as radio telescopes, transmit signals which are processed according to various assumptions to give useful data, so neural signals are processed to give data for perception. To understand perception, the signal codes and the stored knowledge or assumptions used for deriving perceptual hypotheses must be discovered. Systematic perceptual errors are important clues for appreciating signal channel limitations, and for discovering hypothesis-generating procedures. Although this distinction between `physiological' and `cognitive' aspects of perception may be logically clear, it is in practice surprisingly difficult to establish which are responsible even for clearly established phenomena such as the classical distortion illusions. Experimental results are presented, aimed at distinguishing between and discovering what happens when there is mismatch with the neural signal channel, and when neural signals are processed inappropriately for the current situation. This leads us to make some distinctions between perceptual and scientific hypotheses, which raise in a new form the problem: What are `objects'?

  6. Intelligence Current in Creative Activities

    Shi, Jiannong

    2004-01-01

    In this paper, the term 'intelligence current' is further explained and the problems found in relationships between (among) creativity, intelligence, attitude and environmental factors are discussed, according to the systematic model of creativity previously developed by the author. In this model, the performance of an individual's creativity is…

  7. Does bipolar pacemaker current activate blood platelets?

    Gjesdal, Grunde; Hansen, Annebirthe Bo; Brandes, Axel

    2009-01-01

    platelets and muscle cells contain actin and myosin filaments, and both cells are activated following calcium influx. Muscle cells open their calcium channels and contract when exposed to an electric current. Current through a bipolar pacemaker lead will expose a small volume of blood, including platelets......, to the depolarizing current. Platelet activation may ensue, resulting in aggregation, release reaction, and contraction. In contrast, a unipolar pacemaker system will not depolarize blood, but transmit current directly into the myocardium, and the current afterward passes through other tissues before...

  8. DENSITY CURRENTS IN ACTIVATED SLUDGE SECONDARY CLARIFIERS

    Density currents form in activated sludge secondary clarifiers because the mixed liquor has a density greater than the treated wastewater in the clarifier. This causes the mixed liquor to plunge to the bottom of the clarifier establishing relatively high velocity currents within ...

  9. A linear combination of pharmacophore hypotheses as a new tool in search of new active compounds--an application for 5-HT1A receptor ligands.

    Dawid Warszycki

    Full Text Available This study explores a new approach to pharmacophore screening involving the use of an optimized linear combination of models instead of a single hypothesis. The implementation and evaluation of the developed methodology are performed for a complete known chemical space of 5-HT1AR ligands (3616 active compounds with K i < 100 nM acquired from the ChEMBL database. Clusters generated from three different methods were the basis for the individual pharmacophore hypotheses, which were assembled into optimal combinations to maximize the different coefficients, namely, MCC, accuracy and recall, to measure the screening performance. Various factors that influence filtering efficiency, including clustering methods, the composition of test sets (random, the most diverse and cluster population-dependent and hit mode (the compound must fit at least one or two models from a final combination were investigated. This method outmatched both single hypothesis and random linear combination approaches.

  10. Testing statistical hypotheses

    Lehmann, E L

    2005-01-01

    The third edition of Testing Statistical Hypotheses updates and expands upon the classic graduate text, emphasizing optimality theory for hypothesis testing and confidence sets. The principal additions include a rigorous treatment of large sample optimality, together with the requisite tools. In addition, an introduction to the theory of resampling methods such as the bootstrap is developed. The sections on multiple testing and goodness of fit testing are expanded. The text is suitable for Ph.D. students in statistics and includes over 300 new problems out of a total of more than 760. E.L. Lehmann is Professor of Statistics Emeritus at the University of California, Berkeley. He is a member of the National Academy of Sciences and the American Academy of Arts and Sciences, and the recipient of honorary degrees from the University of Leiden, The Netherlands and the University of Chicago. He is the author of Elements of Large-Sample Theory and (with George Casella) he is also the author of Theory of Point Estimat...

  11. Pathophysiology of duchenne muscular dystrophy: current hypotheses.

    Deconinck, Nicolas; Dan, Bernard

    2007-01-01

    Duchenne muscular dystrophy is a devastating inherited neuromuscular disorder that affects one in 3300 live male births. Although the responsible gene and its product, dystrophin, have been characterized for more than 15 years, and a mouse model (mdx) has been developed, comprehensive understanding of the mechanism leading from the absence of dystrophin to the muscular degeneration is still debated. First, dystrophin is considered a key structural element in the muscle fiber, and the primary ...

  12. Urinary plasmin activates collecting duct ENaC current in preeclampsia

    Buhl, KB; Friis, Ulla Glenert; Svenningsen, Per; Gulaveerasingam, Ambika; Ovesen, Per; Frederiksen-Møller, Britta; Jespersen, Bente; Bistrup, Claus; Jensen, Linda Boye

    2012-01-01

    In nephrotic syndrome, plasminogen is aberrantly filtered from plasma to the urinary space and activated along the tubular system. In vitro, plasmin increases ENaC current by proteolytic cleavage of the γ-subunit. It was hypothesized that preeclampsia is associated with plasmin-dependent ability of...

  13. Electric current-induced lymphatic activation.

    Kajiya, Kentaro; Matsumoto-Okazaki, Yuko; Sawane, Mika; Fukada, Kaedeko; Takasugi, Yuya; Akai, Tomonori; Saito, Naoki; Mori, Yuichiro

    2014-12-01

    The lymphatic system in skin plays important roles in drainage of wastes and in the afferent phase of immune response. We previously showed that activation of vascular endothelial growth factor receptor (VEGFR), specifically the VEGFC/VEGFR-3 pathway, attenuates oedema and inflammation by promoting lymphangiogenesis, suggesting a protective role of lymphatic vessels against skin inflammation. However, it remains unknown how physical stimuli promote lymphatic function. Here, we show that lymphatic endothelial cells (LECs) are activated by direct-current (DC) electrical stimulation, which induced extension of actin filaments of LECs, increased calcium influx into LECs, and increased phosphorylation of p38 mitogen-activated protein kinase (MAPK). An inhibitor of focal adhesion kinase, which plays a role in cellular adhesion and motility, diminished the DC-induced extension of F-actin and abrogated p38 phosphorylation. Time-lapse imaging revealed that pulsed-DC stimulation promoted proliferation and migration of LECs. Overall, these results indicate that electro-stimulation activates lymphatic function by activating p38 MAPK. PMID:25308203

  14. Current activities at the MIT Research Reactor

    The MIT Research Reactor (MITR) is a MW nuclear research reactor that is owned and operated by the Massachusetts Institute of Technology to further its educational and research goals at both the undergraduate and graduate level. The reactor first achieved criticality in 1958. It was largely rebuilt in 1973/1974 by MIT staff and students, and its current license expires in August 1999. The current facility, which is designated as the MITR-H, uses a compact core with finned, aluminum-clad, plate-type fuel that is cooled and moderated by light water and reflected by heavy water. The reactor core can hold twenty-seven fuel elements. However, the normal configuration is twenty-four elements. A maximum of four fuel elements can be replaced with in-core experimental facilities. A unique feature of the MITR-II's design is that fixed absorber plates can be inserted in the upper half of the core. These cause the flux to peak in the lower half which benefits experimenters and also facilitates a fuel strategy that involves inversion of fuel elements midway through their life cycle. The MITR-II currently operates continuously for four weeks followed by shutdown of a few days for maintenance. This paper provides an overview of current activities at the MITR including preparations for re-licensing. The status of an on-going Phase-I clinical trial of boron neutron capture therapy for both glioblastoma multiforme and metastatic melanoma is described as well as the design of a fission converter facility for BNCT. Environmental research using neutron activation analysis is summarized as well as in-pile research focussed on LWR water chemistry and structural materials. (author)

  15. On active current selection for Lagrangian profilers

    Jouffroy, Jerome; Zhou, Qiuyang; Zielinski, Oliver

    2013-01-01

    Autonomous Lagrangian profilers are now widely used as measurement and monitoring platforms, notably in observation programs as Argo. In a typical mode of operation, the profilers drift passively at their parking depth before making a vertical profile to go back to the surface. This paper presents...... simple and computationally-efficient control strategies to actively select and use ocean currents so that a profiler can autonomously reach a desired destination. After briefly presenting a typical profiler and possible mechanical modifications for a coastal environment, we introduce simple mathematical...

  16. Pederson Current Dissipation In Emerging Active Regions

    Leake, James E.; Linton, M. G.

    2011-05-01

    Pederson current dissipation in emerging active regions. Certain regions of the solar atmosphere, such as the photosphere and chromosphere, as well as prominences, contain a significant amount of neutral atoms, and a complete description of the plasma requires including the effects of partial ionization. In the chromosphere the dissipation of Pederson currents is important for the evolution of emerging magnetic fields. Due to the relatively high number density in the chromosphere, the ion-neutral collision time-scale is much smaller than timescales associated with flux emergence. Hence we use a single-fluid approach to model the partially ionized plasma. Looking at both the emergence of large-scale sub-surface structures, and the emergence and reconnection of undulatory fields, we investigate the effect of Pederson current dissipation on the state of the emerging field, on magnetic reconnection and on dissipative heating of the atmosphere. Specifically we examine the effect of motions across fieldlines in the partially ionized regions, and how this can increase the free energy supplied to the corona by flux emergence. We also look at reconnection associated with flux emergence in the partially ionized atmosphere, and how this can account for observed small-scale brightenings (Ellerman Bombs).

  17. Alternating Current Influences Anaerobic Electroactive Biofilm Activity.

    Wang, Xin; Zhou, Lean; Lu, Lu; Lobo, Fernanda Leite; Li, Nan; Wang, Heming; Park, Jaedo; Ren, Zhiyong Jason

    2016-09-01

    Alternating current (AC) is known to inactivate microbial growth in suspension, but how AC influences anaerobic biofilm activities has not been systematically investigated. Using a Geobacter dominated anaerobic biofilm growing on the electrodes of microbial electrochemical reactors, we found that high frequency AC ranging from 1 MHz to 1 kHz (amplitude of 5 V, 30 min) showed only temporary inhibition to the biofilm activity. However, lower frequency (100 Hz, 1.2 or 5 V) treatment led to 47 ± 19% permanent decrease in limiting current on the same biofilm, which is attributed to the action of electrohydrodynamic force that caused biofilm damage and loss of intercellular electron transfer network. Confocal microscopy images show such inactivation mainly occurred at the interface between the biofilm and the electrode. Reducing the frequency further to 1 Hz led to water electrolysis, which generated gas bubbles that flushed all attached cells out of the electrode. These findings provide new references on understanding and regulating biofilm growth, which has broader implications in biofouling control, anaerobic waste treatment, energy and product recovery, and general understanding of microbial ecology and physiology. PMID:27485403

  18. GIS interoperability: current activities and military implications

    Lam, Sylvia

    1997-07-01

    Geographic information systems (GIS) are gaining importance in military operations because of their capability to spatially and visually integrate various kinds of information. In an era of limited resources, geospatial data must be shared efficiently whenever possible. The military-initiated Global Geospatial Information and Services (GGI&S) Project aims at developing the infrastructure for GIS interoperability for the military. Current activities in standardization and new technology have strong implications on the design and development of GGI&S. To facilitate data interoperability at both the national and international levels, standards and specifications in geospatial data sharing are being studied, developed and promoted. Of particular interest to the military community are the activities related to the NATO DIGEST, ISO TC/211 Geomatics standardization and the industry-led Open Geodata Interoperability Specifications (OGIS). Together with new information technology, standardization provides the infrastructure for interoperable GIS for both civilian and military environments. The first part of this paper describes the major activities in standardization. The second part presents the technologies developed at DREV in support of the GGI&S. These include the Open Geospatial Datastore Interface (OGDI) and the geospatial data warehouse. DREV has been working closely with Defence Geomatics and private industry in the research and development of new technology for the GGI&S project.

  19. Current activities at the MIT research reactor

    The MIT Research Reactor (MITR) is a 5 MW nuclear research reactor that is owned and operated by the Massachusetts Institute of Technology to further its educational and research goals at both the undergraduate and graduate level. The facility (MITR-II) uses finned, aluminum-clad, plate-type fuel that is cooled and moderated by light water and reflected by heavy water. This paper provides an overview of current activities at the MITR including: (1) The current operating license will expire in August 1999. A decision has been made to pursue a power upgrade to the maximum level (6-7 MW) that can be safely supported by the existing heat removal equipment. Preparation of relicensing documents and results of thermal hydraulic studies are reviewed. (2) The status of an on-going phase-I clinical trial of BNCT for both glioblastoma multiform and metastatic melanoma will be reported. (3) A fission converter facility has been designed for advanced BNCT clinical trials and for routine therapy. This facility will provide a high quality epithermal neutron beam which is capable of treating a patient in a few minutes. Construction of the facility is currently in progress. The facility's design is summarized. (4) A recent study that was completed at the MIT-II using NAA is reported. This study entailed evaluation of the air quality in Upstate New York from October 1991 through September 1993. (5) A number of unique experimental water loop facilities for the study of light water power reactor coolant chemistry have been installed and operated in the MITR-II. The capabilities and the research objectives addressed by these facilities are summarized. (author)

  20. Current activities at the MIT research reactor

    Hu, Lin Wen; Bernard, John A.; Harling, Otto K.; Kohse, Gordon E.; Olmez, Ilhan [MIT, Cambridge (United States)

    1998-07-01

    The MIT Research Reactor (MITR) is a 5 MW nuclear research reactor that is owned and operated by the Massachusetts Institute of Technology to further its educational and research goals at both the undergraduate and graduate level. The facility (MITR-II) uses finned, aluminum-clad, plate-type fuel that is cooled and moderated by light water and reflected by heavy water. This paper provides an overview of current activities at the MITR including: (1) The current operating license will expire in August 1999. A decision has been made to pursue a power upgrade to the maximum level (6-7 MW) that can be safely supported by the existing heat removal equipment. Preparation of relicensing documents and results of thermal hydraulic studies are reviewed. (2) The status of an on-going phase-I clinical trial of BNCT for both glioblastoma multiform and metastatic melanoma will be reported. (3) A fission converter facility has been designed for advanced BNCT clinical trials and for routine therapy. This facility will provide a high quality epithermal neutron beam which is capable of treating a patient in a few minutes. Construction of the facility is currently in progress. The facility's design is summarized. (4) A recent study that was completed at the MIT-II using NAA is reported. This study entailed evaluation of the air quality in Upstate New York from October 1991 through September 1993. (5) A number of unique experimental water loop facilities for the study of light water power reactor coolant chemistry have been installed and operated in the MITR-II. The capabilities and the research objectives addressed by these facilities are summarized. (author)

  1. Current activities at the Finnish TRIGA reactor

    The FiR 1 reactor, a 250 kW TRIGA reactor, with its subsystems has experienced a large renovation work. The main purpose of the upgrading has been to install the new Boron Neutron Capture Therapy (BNCT) irradiation facility. The epithermal neutrons are produced from the fast fission neutrons by a moderator block consisting of Al+AlF3 (FLUENTAL), which showed to be the optimum material for this purpose. The BNCT work dominates the current utilisation of the reactor: four days per week for BNCT purposes and only one day per week for neutron activation analysis and isotope production. The first ten patients have already been irradiated during a period of about twelve months. The Council of State (government) granted at the end of last year a new operating license for the reactor for twelve years. There is a special condition in the new license. One has now about four years' time to achieve a binding agreement between VTT and the Nuclear Power Plants about the possibility to use the final disposal facility of the Nuclear Power Plants for the spent fuel. If this will not happen, one intends to use the USDOE alternative with the well-known time limits. Recently it was started a project to study the possibilities and limitations to increase the power of the reactor to 500 kW or more. In the BNC Therapy in some cases there is the need to increase the penetration depth of the neutrons. This can be arranged by filtering low energy neutrons away from the epithermal beam. The only way to compensate the loss of neutron intensity caused by the filter is to increase the power of the reactor. (authors)

  2. On Active Current Selection for Lagrangian Profilers

    J. Jouffroy

    2013-01-01

    Full Text Available Autonomous Lagrangian profilers are now widely used as measurement and monitoring platforms, notably in observation programs as Argo. In a typical mode of operation, the profilers drift passively at their parking depthbefore making a vertical profile to go back to the surface. This paperpresents simple and computationally-efficient control strategies to activelyselect and use ocean currents so that a profiler can autonomously reach adesired destination. After briefly presenting a typical profiler andpossible mechanical modifications for a coastal environment, we introducesimple mathematical models for the profiler and the currents it will use. Wethen present simple feedback controllers that, using the direction of thecurrents and taking into account the configuration of the environment(coastal or deep-sea, is able to steer the profiler to any desiredhorizontal location. To illustrate the approach, a few results are presentedusing both simulated currents and real current velocity profiles from theNorth Sea.

  3. Active Debris Removal: Current Status of Activities in CNES

    Bonnal, Christophe; Ruault, Jean-Marc; Desjean, Marie-Christine

    2013-08-01

    Most of the ongoing studies led at worldwide level, mainly through IADC Actions, conclude that in order to keep a stable Low Earth Orbit environment in the coming decades, it may be necessary to retrieve some 5 to 10 large objects annually. These operations, known as Active Debris Removal (ADR), raise a huge amount of difficulties in numerous domains: political, legal, insurance, defense, financing and, last but not least, technical questions. The current paper aims at reviewing the current status of the ADR activities led by CNES both at National and Multi-lateral level. The first question which is raised is that of the high level requirements to be applied. What are the requirements coming from the operators; do we want to stabilize the environment, decrease it or could we accept some increase over the years; when do we have to act; can we baseline random reentry of such large objects or do we have to stick to controlled destructive reentries?… There may not yet be clear answers to these points, so efforts at international level are required. The second part of the paper deals with the potential solutions at system level. Numerous possibilities can be identified, depending on the size of the launcher and of the strategy selected to de-orbit the debris. Large space tugs visiting some 10 debris or small dedicated chasers launched as piggyback are among the solutions which have been traded. The currently preferred solution is described in details. The third part of the paper is devoted to the chaser-debris operations themselves, following five key functions; - the long range rendezvous, - the short range rendezvous up to contact, - the mechanical interfacing of the debris, - its control by the chaser, when required, - the de-orbiting maneuver itself. For each of these functions, the current status of available technologies is described, enabling the identification of the most critical ones requiring additional R&T effort and subsequent demonstrations. Among them

  4. Active Power Filter Using Predicted Current Control

    Xiaojie, Y.; Pivoňka, P.; Valouch, Viktor

    2001-01-01

    Roč. 46, č. 1 (2001), s. 41-50. ISSN 0001-7043 Institutional research plan: CEZ:AV0Z2057903 Keywords : active power filter * control strategy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  5. Current activities at the DELTA THz beamline

    In addition to an InSb Bolometer, which detects laser-induced coherent THz pulses at the synchrotron light source DELTA since June 2011, a Fourier transform infrared spectrometer is currently being commissioned. Furthermore, a fast hot-electron bolometer has been used in cooperation with the Karlsruhe Institute of Technology to study the evolution of the laser-induced electron density modulation over several revolutions in the storage ring.

  6. Current activities at the DELTA THz beamline

    Ungelenk, Peter; Hoener, Markus; Huck, Holger; Khan, Shaukat; Molo, Robert; Schick, Andreas; Zeinalzadeh, Maryam [Center for Synchrotron Radiation (DELTA), TU Dortmund University, 44227 Dortmund (Germany)

    2013-07-01

    In addition to an InSb Bolometer, which detects laser-induced coherent THz pulses at the synchrotron light source DELTA since June 2011, a Fourier transform infrared spectrometer is currently being commissioned. Furthermore, a fast hot-electron bolometer has been used in cooperation with the Karlsruhe Institute of Technology to study the evolution of the laser-induced electron density modulation over several revolutions in the storage ring.

  7. Cardiac allograft immune activation: current perspectives

    Chang D; Kobashigawa J

    2014-01-01

    David Chang, Jon Kobashigawa Cedars-Sinai Heart Institute, Los Angeles, CA, USA Abstract: Heart transplant remains the most durable option for end-stage heart disease. Cardiac allograft immune activation and heart transplant rejection remain among the main complications limiting graft and recipient survival. Mediators of the immune system can cause different forms of rejection post-heart transplant. Types of heart transplant rejection include hyperacute rejection, cellular rejection, antibod...

  8. A voltage-activated proton current in human cardiac fibroblasts

    A voltage-activated proton current in human cardiac fibroblasts, measured using the whole-cell recording configuration of the patch-clamp technique, is reported. Increasing the pH of the bathing solution shifted the current activation threshold to more negative potentials and increased both the current amplitude and its rate of activation. Changing the pH gradient by one unit caused a 51 mV shift in the reversal potential of the current, demonstrating a high selectivity for protons of the channel carrying the current. Extracellularly applied Zn2+ reversibly inhibited the current. Activation of the current contributes to the resting membrane conductance under conditions of intracellular acidosis. It is proposed that this current in cardiac fibroblasts is involved in the regulation of the intracellular pH and the membrane potential under physiological conditions as well as in response to pathological conditions such as ischemia

  9. Testing statistical hypotheses of equivalence

    Wellek, Stefan

    2010-01-01

    Equivalence testing has grown significantly in importance over the last two decades, especially as its relevance to a variety of applications has become understood. Yet published work on the general methodology remains scattered in specialists' journals, and for the most part, it focuses on the relatively narrow topic of bioequivalence assessment.With a far broader perspective, Testing Statistical Hypotheses of Equivalence provides the first comprehensive treatment of statistical equivalence testing. The author addresses a spectrum of specific, two-sided equivalence testing problems, from the

  10. Properties of the calcium-activated chloride current in heart

    1992-01-01

    We used the whole cell patch clamp technique to study transient outward currents of single rabbit atrial cells. A large transient current, IA, was blocked by 4-aminopyridine (4AP) and/or by depolarized holding potentials. After block of IA, a smaller transient current remained. It was completely blocked by nisoldipine, cadmium, ryanodine, or caffeine, which indicates that all of the 4AP-resistant current is activated by the calcium transient that causes contraction. Neither calcium- activated...

  11. Current Russian activities in P and T

    Russian activities aimed at setting up the future fuel cycle of nuclear power with reasonably minimised quantities of radwaste for disposal, are carried out by Minatom as part of General Strategy for development of RF nuclear power. Task named 'Transmutation' was set up in 2001, to develop a scenario for transition to the fuel cycle of future large-scale nuclear power. This presentation describes the transmutation nuclear fuel cycle, scenarios studies, partitioning assumptions, fuel reprocessing alternatives. Minor actinides (MA) irradiation results are shown together with the optimisation of transmutation modes. Nuclear data from available nuclear data libraries ENDF/B-IV and JENDL-3.2, and BROND were verified for MA. The following alternative P and T concepts are discussed: subcritical blankets with a accelerator driven target; dedicated transmutation blankets for fission reactors; and integral fuel cycle concepts (molten salt reactor)

  12. Cardiac allograft immune activation: current perspectives

    Chang D

    2014-12-01

    Full Text Available David Chang, Jon Kobashigawa Cedars-Sinai Heart Institute, Los Angeles, CA, USA Abstract: Heart transplant remains the most durable option for end-stage heart disease. Cardiac allograft immune activation and heart transplant rejection remain among the main complications limiting graft and recipient survival. Mediators of the immune system can cause different forms of rejection post-heart transplant. Types of heart transplant rejection include hyperacute rejection, cellular rejection, antibody-mediated rejection, and chronic rejection. In this review, we will summarize the innate and adaptive immune responses which influence the post-heart transplant recipient. Different forms of rejection and their clinical presentation, detection, and immune monitoring will be discussed. Treatment of heart transplant rejection will be examined. We will discuss potential treatment strategies for preventing rejection post-transplant in immunologically high-risk patients with antibody sensitization. Keywords: heart transplant, innate immunity, adaptive immunity, rejection, immunosuppression

  13. DISTRIBUTION OF ELECTRIC CURRENTS IN SOLAR ACTIVE REGIONS

    There has been a long-standing debate on the question of whether or not electric currents in solar active regions are neutralized. That is, whether or not the main (or direct) coronal currents connecting the active region polarities are surrounded by shielding (or return) currents of equal total value and opposite direction. Both theory and observations are not yet fully conclusive regarding this question, and numerical simulations have, surprisingly, barely been used to address it. Here we quantify the evolution of electric currents during the formation of a bipolar active region by considering a three-dimensional magnetohydrodynamic simulation of the emergence of a sub-photospheric, current-neutralized magnetic flux rope into the solar atmosphere. We find that a strong deviation from current neutralization develops simultaneously with the onset of significant flux emergence into the corona, accompanied by the development of substantial magnetic shear along the active region's polarity inversion line. After the region has formed and flux emergence has ceased, the strong magnetic fields in the region's center are connected solely by direct currents, and the total direct current is several times larger than the total return current. These results suggest that active regions, the main sources of coronal mass ejections and flares, are born with substantial net currents, in agreement with recent observations. Furthermore, they support eruption models that employ pre-eruption magnetic fields containing such currents

  14. Distribution of Electric Currents in Solar Active Regions

    Török, Tibor; Titov, Viacheslav S; Archontis, Vasilis; Mikić, Zoran; Linton, Mark G; Dalmasse, Kévin; Aulanier, Guillaume; Kliem, Bernhard

    2014-01-01

    There has been a long-lasting debate on the question of whether or not electric currents in solar active regions are neutralized. That is, whether or not the main (or direct) coronal currents connecting the active region polarities are surrounded by shielding (or return) currents of equal total value and opposite direction. Both theory and observations are not yet fully conclusive regarding this question, and numerical simulations have, surprisingly, barely been used to address it. Here we quantify the evolution of electric currents during the formation of a bipolar active region by considering a three-dimensional magnetohydrodynamic simulation of the emergence of a sub-photospheric, current-neutralized magnetic flux rope into the solar atmosphere. We find that a strong deviation from current neutralization develops simultaneously with the onset of significant flux emergence into the corona, accompanied by the development of substantial magnetic shear along the active region's polarity inversion line. After t...

  15. Testing competing hypotheses about single trial fMRI

    Hansen, Lars Kai; Purushotham, Archana; Kim, Seong-Ge

    We use a Bayesian framework to compute probabilities of competing hypotheses about functional activation based on single trial fMRI measurements. Within the framework we obtain a complete probabilistic picture of competing hypotheses, hence control of both type I and type II errors....

  16. NOS CO-OPS Active Currents Data, 6-Minute

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has surface Active Currents data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). WARNING: These raw data have not...

  17. Consciousness, biology and quantum hypotheses.

    Baars, Bernard J; Edelman, David B

    2012-09-01

    , unpredictable and highly valued life events, such as evading predators, gathering critical information, seeking mates and hunting prey. Attentional selection of conscious events can be observed behaviorally in animals showing coordinated receptor orienting, flexible responding, alertness, emotional reactions, seeking, motivation and curiosity, as well as behavioral surprise and cortical and autonomic arousal. Brain events corresponding to attentional selection are prominent and widespread. Attention generally results in conscious experiences, which may be needed to recruit widespread processing resources in the brain. Many neuronal processes never become conscious, such as the balance system of the inner ear. An air traveler may "see" the passenger cabin tilt downward as the plane tilts to descend for a landing. That visual experience occurs even at night, when the traveler has no external frame of spatial reference. The passenger's body tilt with respect to gravity is detected unconsciously via the hair cells of the vestibular canals, which act as liquid accelerometers. However, that sensory activity is not experienced directly. It only becomes conscious via vision and the body senses. The vestibular sense is therefore quite different from visual perception, which "reports" accurately to a conscious field of experience, so that we can point accurately to a bright star on a dark night. Vestibular input is also precise but unconscious. Conscious cognition is therefore a distinct kind of brain event. Many of its features are well established, and must be accounted for by any adequate theory. No non-biological examples are known. Penrose and Hameroff have proposed that consciousness may be viewed as a fundamental problem in quantum physics. Specifically, their 'orchestrated objective reduction' (Orch-OR) hypothesis posits that conscious states arise from quantum computations in the microtubules of neurons. However, a number of microtubule-associated proteins are found in both

  18. Consciousness, biology and quantum hypotheses

    Baars, Bernard J.; Edelman, David B.

    2012-09-01

    , unpredictable and highly valued life events, such as evading predators, gathering critical information, seeking mates and hunting prey. Attentional selection of conscious events can be observed behaviorally in animals showing coordinated receptor orienting, flexible responding, alertness, emotional reactions, seeking, motivation and curiosity, as well as behavioral surprise and cortical and autonomic arousal. Brain events corresponding to attentional selection are prominent and widespread. Attention generally results in conscious experiences, which may be needed to recruit widespread processing resources in the brain. Many neuronal processes never become conscious, such as the balance system of the inner ear. An air traveler may “see” the passenger cabin tilt downward as the plane tilts to descend for a landing. That visual experience occurs even at night, when the traveler has no external frame of spatial reference. The passenger's body tilt with respect to gravity is detected unconsciously via the hair cells of the vestibular canals, which act as liquid accelerometers. However, that sensory activity is not experienced directly. It only becomes conscious via vision and the body senses. The vestibular sense is therefore quite different from visual perception, which “reports” accurately to a conscious field of experience, so that we can point accurately to a bright star on a dark night. Vestibular input is also precise but unconscious. Conscious cognition is therefore a distinct kind of brain event. Many of its features are well established, and must be accounted for by any adequate theory. No non-biological examples are known. Penrose and Hameroff have proposed that consciousness may be viewed as a fundamental problem in quantum physics. Specifically, their ‘orchestrated objective reduction’ (Orch-OR) hypothesis posits that conscious states arise from quantum computations in the microtubules of neurons. However, a number of microtubule-associated proteins are found

  19. Inferred flows of electric currents in solar active regions

    Techniques to identify sources of major current systems in active regions and their channels of flow are explored. Measured photospheric vector magnetic fields together with high resolution white light and H-alpha photographs provide the data base to derive the current systems in the photosphere and chromosphere of a solar active region. Simple mathematical constructions of active region fields and currents are used to interpret these data under the assumptions that the fields in the lower atmosphere (below 200 km) may not be force free but those in the chromosphere and higher are. The results obtained for the complex active region AR 2372 are: (1) Spots exhibiting significant spiral structure in the penumbral filaments were the source of vertical currents at the photospheric surface; (2) Magnetic neutral lines where the transverse magnetic field was strongly sheared were channels along which a strong current system flowed; (3) The inferred current systems produced a neutral sheet and oppositely-flowing currents in the area of the magnetic delta configuration that was the site of flaring

  20. Necessary Condition Hypotheses in Operations Management

    Dul, Jan; Hak, Tony; Goertz, Gary; Voss, Chris

    2010-01-01

    textabstractPurpose – To show that necessary condition hypotheses are important in operations management, and to present a consistent methodology for building and testing them. Necessary condition hypotheses (“X is necessary for Y”) express conditions that must be present in order to have a desired outcome (e.g. “success”), and to prevent guaranteed failure. These hypotheses differ fundamentally from the common co-variational hypotheses (“more X results in more Y”) and require another methodo...

  1. CURRENT AND KINETIC HELICITY OF LONG-LIVED ACTIVITY COMPLEXES

    We study long-lived activity complexes and their current helicity at the solar surface and their kinetic helicity below the surface. The current helicity has been determined from synoptic vector magnetograms from the NSO/SOLIS facility, and the kinetic helicity of subsurface flows has been determined with ring-diagram analysis applied to full-disk Dopplergrams from NSO/GONG and SDO/HMI. Current and kinetic helicity of activity complexes follow the hemispheric helicity rule with mainly positive values (78%; 78%, respectively, with a 95% confidence level of 31%) in the southern hemisphere and negative ones (80%; 93%, respectively, with a 95% confidence level of 22% and 14%, respectively) in the northern hemisphere. The locations with the dominant sign of kinetic helicity derived from Global Oscillation Network Group (GONG) and SDO/HMI data are more organized than those of the secondary sign even if they are not part of an activity complex, while locations with the secondary sign are more fragmented. This is the case for both hemispheres even for the northern one where it is not as obvious visually due to the large amount of magnetic activity present as compared to the southern hemisphere. The current helicity shows a similar behavior. The dominant sign of current helicity is the same as that of kinetic helicity for the majority of the activity complexes (83% with a 95% confidence level of 15%). During the 24 Carrington rotations analyzed here, there is at least one longitude in each hemisphere where activity complexes occur repeatedly throughout the epoch. These ''active'' longitudes are identifiable as locations of strong current and kinetic helicity of the same sign

  2. Consciousness, biology and quantum hypotheses

    Baars, Bernard J.; Edelman, David B.

    2012-09-01

    , unpredictable and highly valued life events, such as evading predators, gathering critical information, seeking mates and hunting prey. Attentional selection of conscious events can be observed behaviorally in animals showing coordinated receptor orienting, flexible responding, alertness, emotional reactions, seeking, motivation and curiosity, as well as behavioral surprise and cortical and autonomic arousal. Brain events corresponding to attentional selection are prominent and widespread. Attention generally results in conscious experiences, which may be needed to recruit widespread processing resources in the brain. Many neuronal processes never become conscious, such as the balance system of the inner ear. An air traveler may “see” the passenger cabin tilt downward as the plane tilts to descend for a landing. That visual experience occurs even at night, when the traveler has no external frame of spatial reference. The passenger's body tilt with respect to gravity is detected unconsciously via the hair cells of the vestibular canals, which act as liquid accelerometers. However, that sensory activity is not experienced directly. It only becomes conscious via vision and the body senses. The vestibular sense is therefore quite different from visual perception, which “reports” accurately to a conscious field of experience, so that we can point accurately to a bright star on a dark night. Vestibular input is also precise but unconscious. Conscious cognition is therefore a distinct kind of brain event. Many of its features are well established, and must be accounted for by any adequate theory. No non-biological examples are known. Penrose and Hameroff have proposed that consciousness may be viewed as a fundamental problem in quantum physics. Specifically, their ‘orchestrated objective reduction’ (Orch-OR) hypothesis posits that conscious states arise from quantum computations in the microtubules of neurons. However, a number of microtubule-associated proteins are found

  3. IS THE CURRENT LACK OF SOLAR ACTIVITY ONLY SKIN DEEP?

    The Sun is a variable star whose magnetic activity and total irradiance vary on a timescale of approximately 11 years. The current activity minimum has attracted considerable interest because of its unusual duration and depth. This raises the question: what might be happening beneath the surface where the magnetic activity ultimately originates? The surface activity can be linked to the conditions in the solar interior by the observation and analysis of the frequencies of the Sun's natural seismic modes of oscillation-the p modes. These seismic frequencies respond to changes in activity and are probes of conditions within the Sun. The Birmingham Solar-Oscillations Network (BiSON) has made measurements of p-mode frequencies over the last three solar activity cycles, and so is in a unique position to explore the current unusual and extended solar minimum. We show that the BiSON data reveal significant variations of the p-mode frequencies during the current minimum. This is in marked contrast to the surface activity observations, which show little variation over the same period. The level of the minimum is significantly deeper in the p-mode frequencies than in the surface observations. We observe a quasi-biennial signal in the p-mode frequencies, which has not previously been observed at mid- and low-activity levels. The stark differences in the behavior of the frequencies and the surface activity measures point to activity-related processes occurring in the solar interior, which are yet to reach the surface, where they may be attenuated.

  4. Is the current lack of solar activity only skin deep?

    Broomhall, A -M; Elsworth, Y; Fletcher, S T; New, R; 10.1088/0004-637X/700/2/L162

    2009-01-01

    The Sun is a variable star whose magnetic activity and total irradiance vary on a timescale of approximately 11 years. The current activity minimum has attracted considerable interest because of its unusual duration and depth. This raises the question: what might be happening beneath the surface where the magnetic activity ultimately originates? The surface activity can be linked to the conditions in the solar interior by the observation and analysis of the frequencies of the Sun's natural seismic modes of oscillation - the p modes. These seismic frequencies respond to changes in activity and are probes of conditions within the Sun. The Birmingham Solar-Oscillations Network (BiSON) has made measurements of p-mode frequencies over the last three solar activity cycles, and so is in a unique position to explore the current unusual and extended solar minimum. We show that the BiSON data reveal significant variations of the p-mode frequencies during the current minimum. This is in marked contrast to the surface ac...

  5. The origin of net electric currents in solar active regions

    Dalmasse, K; Démoulin, P; Kliem, B; Török, T; Pariat, E

    2015-01-01

    There is a recurring question in solar physics about whether or not electric currents are neutralized in active regions (ARs). This question was recently revisited using three-dimensional (3D) magnetohydrodynamic (MHD) numerical simulations of magnetic flux emergence into the solar atmosphere. Such simulations showed that flux emergence can generate a substantial net current in ARs. Another source of AR currents are photospheric horizontal flows. Our aim is to determine the conditions for the occurrence of net vs. neutralized currents with this second mechanism. Using 3D MHD simulations, we systematically impose line-tied, quasi-static, photospheric twisting and shearing motions to a bipolar potential magnetic field. We find that such flows: (1) produce both {\\it direct} and {\\it return} currents, (2) induce very weak compression currents - not observed in 2.5D - in the ambient field present in the close vicinity of the current-carrying field, and (3) can generate force-free magnetic fields with a net current...

  6. Solar Flare Activity and Variability of Electric Current Helicity

    2002-01-01

    Recent study using Huairou vector magnetograph data shows that dur ing flare activity, the current helicity exhibits rapid and substantial variations and,in some cases, a recovering phase. We considered various representative the mag netic confgurations. First, interacting twisted magnetic flux tubes are analyzed separately for positive, negative and mixed-sign helicity regions. The results show that the helicity during flares decreases in positive-sign, and increases in negative sign regions. Then, flaring arcade also shows that the magnitude of the helicity decreases after flares. We also investigated current sheets formed by sheared mag netic field and showed that the current helicity (with either positive and negative signs) vanishes after reconnection. The emergence of twisted flux tubes which can trigger flares may be another source of flare-associated variability of current helicity.We demorstrate the relevance of current helicity to the description of flare activity by compming its variation with that of shear angle in the active region AR 6891.

  7. Current status of research and related activities in NAA application

    Ab. Khalik bin Haji Wood [Malaysia Institute for Nuclear Technology Research, Bangi, Selangor (Malaysia)

    1999-10-01

    Current activities of Analytical Chemistry Group of MINT (Malaysia Institute for Nuclear Technology Research) laboratory for elemental analysis of trace amounts in environmental samples such as air particulate matter (on air filter), soils/sediments, water, flora/fauna, oil sludge/waste sludge, and tailing/blasting slag and others, utilizing particularly NAA (Neutron Activation Analysis) method are reviewed. The laboratory participates in the IAEA-organized Interlaboratory Comparison Studies to ensure the analytical system. Other activities include analytical chemistry services with ICP-mass spectrometry and GC/GCMS to compliment the NAA and, moreover, air and marine pollution studies with participation in the UNDP/RCA/IAEA project. (S. Ohno)

  8. Current status of research and related activities in NAA application

    Current activities of Analytical Chemistry Group of MINT (Malaysia Institute for Nuclear Technology Research) laboratory for elemental analysis of trace amounts in environmental samples such as air particulate matter (on air filter), soils/sediments, water, flora/fauna, oil sludge/waste sludge, and tailing/blasting slag and others, utilizing particularly NAA (Neutron Activation Analysis) method are reviewed. The laboratory participates in the IAEA-organized Interlaboratory Comparison Studies to ensure the analytical system. Other activities include analytical chemistry services with ICP-mass spectrometry and GC/GCMS to compliment the NAA and, moreover, air and marine pollution studies with participation in the UNDP/RCA/IAEA project. (S. Ohno)

  9. Revision of a few hypotheses on speleogenesis.

    Choppy Jacques

    2000-01-01

    Quite often, as we know better karst phenomena and the evolution of the karst environment, several hypotheses on speleogenesis appeared to be flimsy. Some of these hypotheses, concerning processes playing a part in the creation of karst forms, exceed the limits of their field. Others suggest hydraulic mechanisms, and interventions of geological or geographical factors likely to be questioned. Hypotheses relating to the evolution of karst, as well as the classification of karst types, suffer f...

  10. Electroconvulsive treatment: hypotheses about mechanisms of action

    Roar Fosse

    2013-08-01

    Full Text Available No consensus has been reached on the mode of action of electroconvulsive treatment (ECT. We suggest that two features may aid in the delineation of the involved mechanisms. First, when effective, ECT would be likely to affect brain functions that are typically altered in its primary recipient group, people with severe depression. Central among these are the frontal and temporal lobes, the hypothalamus-pituitary-adrenal (HPA stress axis, and the mesocorticolimbic dopamine system. Second, the involved mechanisms should be affected for a time period that matches the average endurance of clinical effects, which is indicated to be several days to a few weeks. To identify effects upon frontal and temporal lobe functioning we reviewed human studies using EEG, PET, SPECT, and fMRI. Effects upon the HPA axis and the dopamine system were assessed by reviewing both human and animal studies. The EEG studies indicate that ECT decelerates neural activity in the frontal and temporal lobes (increased delta and theta wave activity for weeks to months. Comparable findings are reported from PET and SPECT studies, with reduced cerebral blood flow (functional deactivation for weeks to months after treatment. The EEG deceleration and functional deactivation following ECT are statistically associated with reduced depression scores. FMRI studies indicate that ECT flattens the pattern of activation and deactivation that is associated with cognitive task performance and alters cortical functional connectivity in the ultra slow frequency range. A common finding from human and animal studies is that electroconvulsive treatment acutely activates both the HPA axis and the dopamine system. In considering this evidence, we hypothesize that ECT affects the brain in a similar manner as severe stress or brain trauma which activates the HPA axis and the dopamine system and may compromise frontotemporal functions.

  11. Calcium release-activated calcium current in rat mast cells.

    Hoth, M; Penner, R

    1993-06-01

    1. Whole-cell patch clamp recordings of membrane currents and fura-2 measurements of free intracellular calcium concentration ([Ca2+]i) were used to study the biophysical properties of a calcium current activated by depletion of intracellular calcium stores in rat peritoneal mast cells. 2. Calcium influx through an inward calcium release-activated calcium current (ICRAC) was induced by three independent mechanisms that result in store depletion: intracellular infusion of inositol 1,4,5-trisphosphate (InsP3) or extracellular application of ionomycin (active depletion), and intracellular infusion of calcium chelators (ethylene glycol bis-N,N,N',N'-tetraacetic acid (EGTA) or 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA)) to prevent reuptake of leaked-out calcium into the stores (passive depletion). 3. The activation of ICRAC induced by active store depletion has a short delay (4-14 s) following intracellular infusion of InsP3 or extracellular application of ionomycin. It has a monoexponential time course with a time constant of 20-30 s and, depending on the complementary Ca2+ buffer, a mean normalized amplitude (at 0 mV) of 0.6 pA pF-1 (with EGTA) and 1.1 pA pF-1 (with BAPTA). 4. After full activation of ICRAC by InsP3 in the presence of EGTA (10 mM), hyperpolarizing pulses to -100 mV induced an instantaneous inward current that decayed by 64% within 50 ms. This inactivation is probably mediated by [Ca2+]i, since the decrease of inward current in the presence of the fast Ca2+ buffer BAPTA (10 mM) was only 30%. 5. The amplitude of ICRAC was dependent on the extracellular Ca2+ concentration with an apparent dissociation constant (KD) of 3.3 mM. Inward currents were nonsaturating up to -200 mV. 6. The selectivity of ICRAC for Ca2+ was assessed by using fura-2 as the dominant intracellular buffer (at a concentration of 2 mM) and relating the absolute changes in the calcium-sensitive fluorescence (390 nm excitation) with the calcium current integral

  12. Current NDT activities at Cekmece Nuclear Research and Training Center

    Full text: Non-destructive testing (NDT) activities at Cekmece Nuclear Research and Training Center (CNAEM) has been initiated in the Industrial Application Department of the Center which was established in 1976 as the Radioisotope Applications Group for Industry. The Department started its first NDT activity with industrial radiography. The NDT activities have been developed by the support of various national (State Planning Organization (DPT)) and international (IAEA and UNDP) projects. Today, there are five basic NDT techniques (radiography, ultrasonic, magnetic particle, liquid penetrant and eddy current) used in the Industrial Application Department. The Department arranges routinely NDT qualification courses according to ISO 9712 and TS EN 473 standards for level 1 and 2 for Turkish Industry. It also carries out national DPT and IAEA Technical Co-operation projects and gives NDT services in the laboratory and in the field. Digital radiography and digital ultrasonic techniques are being used in advanced NDT applications. This paper describes the NDT activities of CNAEM

  13. Fast inhibition of glutamate-activated currents by caffeine.

    Nicholas P Vyleta

    Full Text Available BACKGROUND: Caffeine stimulates calcium-induced calcium release (CICR in many cell types. In neurons, caffeine stimulates CICR presynaptically and thus modulates neurotransmitter release. METHODOLOGY/PRINCIPAL FINDINGS: Using the whole-cell patch-clamp technique we found that caffeine (20 mM reversibly increased the frequency and decreased the amplitude of miniature excitatory postsynaptic currents (mEPSCs in neocortical neurons. The increase in mEPSC frequency is consistent with a presynaptic mechanism. Caffeine also reduced exogenously applied glutamate-activated currents, confirming a separate postsynaptic action. This inhibition developed in tens of milliseconds, consistent with block of channel currents. Caffeine (20 mM did not reduce currents activated by exogenous NMDA, indicating that caffeine block is specific to non-NMDA type glutamate receptors. CONCLUSIONS/SIGNIFICANCE: Caffeine-induced inhibition of mEPSC amplitude occurs through postsynaptic block of non-NMDA type ionotropic glutamate receptors. Caffeine thus has both pre and postsynaptic sites of action at excitatory synapses.

  14. Improving Industrial Energy Quality by an Active Current Filter

    Reyes–Trujillo E

    2010-10-01

    Full Text Available The growing number of non-linear loads on industrial applications has produced an important impact on the quality of electric power supply due to the increasing of the voltage and current harmonic distortion, and low power factor. In order to solve this, arrangements of capacitors and reactors, known as passive filters have been used. However these filters may produce resonance problems with network impedance, over compensation of reactive power at fundamental frequency, and poor flexibility for dynamic compensation of different frequency harmonic components. As a solution to the problems mentioned above, the active filters have been developed, whose features can be adapted in a dynamic and adjustable way on the requirements of the system to compensate. This paper presents the modelling and simulation results of an active current filter, used to reduce the harmonic distortion and to improve the power factor in an electric industrial system. A six-pulse diode converter has been used as non-linear passive load. During the analysis, it was observed that the total current harmonic distortion (THD was reduced from 16.47% to 0.46%, and the power factor in the distribution bus has improved from 0.5 to 0.95.The waveforms of a three-phase thyristor converter with a DC machine as active non-linear load are shown.

  15. HyQue: evaluating hypotheses using Semantic Web technologies

    Callahan Alison

    2011-05-01

    Full Text Available Abstract Background Key to the success of e-Science is the ability to computationally evaluate expert-composed hypotheses for validity against experimental data. Researchers face the challenge of collecting, evaluating and integrating large amounts of diverse information to compose and evaluate a hypothesis. Confronted with rapidly accumulating data, researchers currently do not have the software tools to undertake the required information integration tasks. Results We present HyQue, a Semantic Web tool for querying scientific knowledge bases with the purpose of evaluating user submitted hypotheses. HyQue features a knowledge model to accommodate diverse hypotheses structured as events and represented using Semantic Web languages (RDF/OWL. Hypothesis validity is evaluated against experimental and literature-sourced evidence through a combination of SPARQL queries and evaluation rules. Inference over OWL ontologies (for type specifications, subclass assertions and parthood relations and retrieval of facts stored as Bio2RDF linked data provide support for a given hypothesis. We evaluate hypotheses of varying levels of detail about the genetic network controlling galactose metabolism in Saccharomyces cerevisiae to demonstrate the feasibility of deploying such semantic computing tools over a growing body of structured knowledge in Bio2RDF. Conclusions HyQue is a query-based hypothesis evaluation system that can currently evaluate hypotheses about the galactose metabolism in S. cerevisiae. Hypotheses as well as the supporting or refuting data are represented in RDF and directly linked to one another allowing scientists to browse from data to hypothesis and vice versa. HyQue hypotheses and data are available at http://semanticscience.org/projects/hyque.

  16. Quantitative linking hypotheses for infant eye movements.

    Daniel Yurovsky

    Full Text Available The study of cognitive development hinges, largely, on the analysis of infant looking. But analyses of eye gaze data require the adoption of linking hypotheses: assumptions about the relationship between observed eye movements and underlying cognitive processes. We develop a general framework for constructing, testing, and comparing these hypotheses, and thus for producing new insights into early cognitive development. We first introduce the general framework--applicable to any infant gaze experiment--and then demonstrate its utility by analyzing data from a set of experiments investigating the role of attentional cues in infant learning. The new analysis uncovers significantly more structure in these data, finding evidence of learning that was not found in standard analyses and showing an unexpected relationship between cue use and learning rate. Finally, we discuss general implications for the construction and testing of quantitative linking hypotheses. MATLAB code for sample linking hypotheses can be found on the first author's website.

  17. Current developments in uranium exploration activities in Egypt

    Current developments in uranium exploration activities since 1993 are summarized, with a brief history of uranium exploration in Egypt. New target for these exploration activities are also outlined. Previous exploration techniques used were: airborne radiometric and magnetic surveys, ground radiometric surveys, regional and detailed geologic mapping, exploratory mining works at the Wadi level, limited diamond drilling, as well as all supplementary laboratory works. Most of these activities were concentrated on the Eastern Desert terrains, particularly in granitic rocks. Main discoveries are four uranium occurrences in Pan African younger granites in addition to one at the contact of bostonite and felsite dykes in metasediments and one in psammitic gneisses in the Eastern Desert, as well as one in siltstone in a Paleozoic sedimentary basin within granitic rocks in Sinai. Two new activities are now underway: exploratory drilling programs in the uranium occurrences in the Eastern Desert and Sinai with newly acquired equipment, and experimental heap leaching of the low grade uranium ores at the site. In addition, some other techniques have been strengthened and updated such as well logging, airborne spectrometric surveys and ground geophysical surveys. Exploration activities have been recently directed also to new target areas in sedimentary formations and intracratonic sedimentary basins. The possibility of the occurrence of unconformity related deposits are also considered. (author). 8 refs, 9 figs

  18. Data Mining Activities for Bone Discipline - Current Status

    Sibonga, J. D.; Pietrzyk, R. A.; Johnston, S. L.; Arnaud, S. B.

    2008-01-01

    The disciplinary goals of the Human Research Program are broadly discussed. There is a critical need to identify gaps in the evidence that would substantiate a skeletal health risk during and after spaceflight missions. As a result, data mining activities will be engaged to gather reviews of medical data and flight analog data and to propose additional measures and specific analyses. Several studies are briefly reviewed which have topics that partially address these gaps in knowledge, including bone strength recovery with recovery of bone mass density, current renal stone formation knowledge, herniated discs, and a review of bed rest studies conducted at Ames Human Research Facility.

  19. Overall review on waste management in Finland - Current regulatory activities

    The Finnish Centre for Radiation and Nuclear Safety is a competent authority responsible for the surveillance of the safety of nuclear installations. Its regulatory duties include surveillance of waste management operations and facilities under construction as well as safety related appraisal of future waste management concepts. The current activities of the Centre in the waste management field are concentrated on formulation of criteria for reactor waste disposal, surveillance of the construction of an interim storage for spent fuel and evaluation of the technical concepts and the preliminary site selection process for spent fuel disposal

  20. Selective Harmonic Current Mitigation with Shunt Active Power Filter

    Hansen, Steffan; Lascu, Cristian; Asiminoaei, Lucian;

    2007-01-01

    drawbacks, the paper shows that the last two methods have a more compact mathematical representation which may extend to straightforward DSP implementation. However, the first method, i.e. selective compensation in harmonic dq-frame, is more flexible and allows a better tuning and adjustment, which is of a......The paper presents three methods of selective harmonic compensation with shunt Active Power Filters in different reference frames: harmonic dq-frame, stationary frame and fundamental dq-frame; and shows that the last two methods are derived from the first one. By analyzing their advantages and...... great importance in practice. For experimental tests only the selective harmonic control in fundamental dq-frame is presented, to demonstrate the selectiveness harmonic current compensation. The experimental results are performed in laboratory conditions on a 7 kVA Active Filter prototype, indicating a...

  1. Using Transcranial tDCS to test cognitive hypotheses

    Nazbanou Nozari

    2014-04-01

    Full Text Available Transcranial Direct Current Stimulation (tDCS is used increasingly often for testing cognitive hypotheses. It is, however, often ignored that many assumptions regarding how the neural tissue reacts to stimulation have only been verified in the motor domain. Extrapolating these assumptions to the cognitive domain has a set of unique issues which, if ignored, can lead to incorrect interpretations. In this talk I will review a number of common pitfalls in using tDCS for testing a cognitive hypothesis, and discuss some solutions for better-controlled designs. I will address the following issues: 1- Making an incorrect assumption about the nature of the effect: It is often assumed that anodal stimulation has “excitatory” and cathodal stimulation has “inhibitory” effects. Results are then interpreted in light of this assumption. Obviously, if the assumption is incorrect, the interpretation of the results too will be incorrect. I will discuss how the effects of polarity can change as a function of a number of design parameters, and the dangers of making a priori assumptions about the direction of stimulation effects, especially when employing a new design. 2- Choosing an inappropriate montage: By definition, tDCS requires two electrodes, although we are often only interested in stimulating one brain region. Where the second (reference electrode is placed may not be of theoretical interest to us, but it can have serious consequences for our effects of interest. For one thing the path of the direct current changes as a function of where the reference electrode is placed. This affects the density of the current, as well as the regions that undergo stimulation. Moreover, the region directly under the reference electrode is very likely to be affected by stimulation. Therefore, sometimes the changes in behavior may be due to the unanticipated effects at the reference electrode site, as opposed to the hypothesized effects at the target electrode site

  2. HIV-1 Tat protein increases microglial outward K(+ current and resultant neurotoxic activity.

    Jianuo Liu

    Full Text Available Microglia plays a crucial role in the pathogenesis of HIV-1-associated neurocognitive disorders. Increasing evidence indicates the voltage-gated potassium (Kv channels are involved in the regulation of microglia function, prompting us to hypothesize Kv channels may also be involved in microglia-mediated neurotoxic activity in HIV-1-infected brain. To test this hypothesis, we investigated the involvement of Kv channels in the response of microglia to HIV-1 Tat protein. Treatment of rat microglia with HIV-1 Tat protein (200 ng/ml resulted in pro-inflammatory microglial activation, as indicated by increases in TNF-α, IL-1β, reactive oxygen species, and nitric oxide, which were accompanied by enhanced outward K(+ current and Kv1.3 channel expression. Suppression of microglial Kv1.3 channel activity, either with Kv1.3 channel blockers Margatoxin, 5-(4-Phenoxybutoxypsoralen, or broad-spectrum K(+ channel blocker 4-Aminopyridine, or by knockdown of Kv1.3 expression via transfection of microglia with Kv1.3 siRNA, was found to abrogate the neurotoxic activity of microglia resulting from HIV-1 Tat exposure. Furthermore, HIV-1 Tat-induced neuronal apoptosis was attenuated with the application of supernatant collected from K(+ channel blocker-treated microglia. Lastly, the intracellular signaling pathways associated with Kv1.3 were investigated and enhancement of microglial Kv1.3 was found to correspond with an increase in Erk1/2 mitogen-activated protein kinase activation. These data suggest targeting microglial Kv1.3 channels may be a potential new avenue of therapy for inflammation-mediated neurological disorders.

  3. Current activities handbook: formerly utilized sites remedial action program

    None

    1981-02-27

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the activities each of the thirteen state legislatures potentially affected by the Formerly Utilized Sites Remedial Action Program. It contains a description of the state legislative procedural rules and a schedule of each legislative session; a summary of pending relevant legislation; the name and telephone number of legislative and state agency contacts; and the full text of all bills identified.

  4. Current activities handbook: formerly utilized sites remedial action program

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the activities each of the thirteen state legislatures potentially affected by the Formerly Utilized Sites Remedial Action Program. It contains a description of the state legislative procedural rules and a schedule of each legislative session; a summary of pending relevant legislation; the name and telephone number of legislative and state agency contacts; and the full text of all bills identified

  5. Radio Astronomy in Malaysia: Current Status and Outreach Activities

    Hashim, N.; Abidin, Z. Z.; Ibrahim, U. F. S. U.; Umar, R.; Hassan, M. S. R.; Rosli, Z.; Hamidi, Z. S.; Ibrahim, Z. A.

    2011-12-01

    In this paper, we will present the current status of radio astronomical research and outreach in Malaysia. We will also present a short history of our research group, which is currently the only radio astronomical facility in Malaysia. Our group is called the Radio Cosmology Research Lab and was established in 2005 by Dr Zamri Zainal Abidin and Prof Dr Zainol Abidin Ibrahim. We will discuss the future plans for this group including our keen interest in being part of a more global network of radio astronomers. We are already an active member of the South-East Asia Astronomy Network (SEAAN) and aims to have a radio astronomical facility in order to join the Global Very Long Baseline Interferometer (VLBI) as well becoming a research hub for the future Square Kilometer Array (SKA) project. We will also present some of the scientific goals of our group including providing a platform for radio astronomers to be able to do observations of weak and high red-shifted radio objects such as galaxy clusters and supernovae.

  6. Validating Inductive Hypotheses by Mode Inference

    王志坚

    1993-01-01

    Sme criteria based on mode inference for validating inductive hypotheses are presented in this paper.Mode inference is caried out mechanically,thus such kind of validation can result in low overhead in consistency check and high efficiency in performance.

  7. Dental Hypotheses: Seeks to Publish Hypotheses from All Areas of Dentistry

    Rossomando, Edward F.

    2010-01-01

    Starting a new open access journal in a rapid growing scientific panorama is a severe challenge. However, the first issue of dental hypotheses is now history and the even skeptics can appreciate that dental hypotheses is a success - it is a journal of high quality that provides an outlet for publication of articles that encourage readers to question dental paradigms. But dental hypotheses readers might have noticed that the majority of the articles published in the first issue of dental hypot...

  8. Testing anatomically specified hypotheses in functional imaging using cytoarchitectonic maps.

    Eickhoff, Simon B; Heim, Stefan; Zilles, Karl; Amunts, Katrin

    2006-08-15

    The statistical inference on functional imaging data is severely complicated by the embedded multiple testing problem. Defining a region of interest (ROI) where the activation is hypothesized a priori helps to circumvent this problem, since in this case the inference is restricted to fewer simultaneous tests, rendering it more sensitive. Cytoarchitectonic maps obtained from postmortem brains provide objective, a priori ROIs that can be used to test anatomically specified hypotheses about the localization of functional activations. We here analyzed three methods for the definition of ROIs based on probabilistic cytoarchitectonic maps. (1) ROIs defined by the volume assigned to a cytoarchitectonic area in the summary map of all areas (maximum probability map, MPM), (2) ROIs based on thresholding the individual probabilistic maps and (3) spherical ROIs build around the cytoarchitectonic center of gravity. The quality with which the thus defined ROIs represented the respective cytoarchitectonic areas as well as their sensitivity for detecting functional activations was subsequently statistically evaluated. Our data showed that the MPM method yields ROIs, which reflect most adequately the underlying anatomical hypotheses. These maps also show a high degree of sensitivity in the statistical analysis. We thus propose the use of MPMs for the definition of ROIs. In combination with thresholding based on the Gaussian random field theory, these ROIs can then be applied to test anatomically specified hypotheses in functional neuroimaging studies. PMID:16781166

  9. Mechanistic Mathematical Modeling Tests Hypotheses of the Neurovascular Coupling in fMRI.

    Lundengård, Karin; Cedersund, Gunnar; Sten, Sebastian; Leong, Felix; Smedberg, Alexander; Elinder, Fredrik; Engström, Maria

    2016-06-01

    Functional magnetic resonance imaging (fMRI) measures brain activity by detecting the blood-oxygen-level dependent (BOLD) response to neural activity. The BOLD response depends on the neurovascular coupling, which connects cerebral blood flow, cerebral blood volume, and deoxyhemoglobin level to neuronal activity. The exact mechanisms behind this neurovascular coupling are not yet fully investigated. There are at least three different ways in which these mechanisms are being discussed. Firstly, mathematical models involving the so-called Balloon model describes the relation between oxygen metabolism, cerebral blood volume, and cerebral blood flow. However, the Balloon model does not describe cellular and biochemical mechanisms. Secondly, the metabolic feedback hypothesis, which is based on experimental findings on metabolism associated with brain activation, and thirdly, the neurotransmitter feed-forward hypothesis which describes intracellular pathways leading to vasoactive substance release. Both the metabolic feedback and the neurotransmitter feed-forward hypotheses have been extensively studied, but only experimentally. These two hypotheses have never been implemented as mathematical models. Here we investigate these two hypotheses by mechanistic mathematical modeling using a systems biology approach; these methods have been used in biological research for many years but never been applied to the BOLD response in fMRI. In the current work, model structures describing the metabolic feedback and the neurotransmitter feed-forward hypotheses were applied to measured BOLD responses in the visual cortex of 12 healthy volunteers. Evaluating each hypothesis separately shows that neither hypothesis alone can describe the data in a biologically plausible way. However, by adding metabolism to the neurotransmitter feed-forward model structure, we obtained a new model structure which is able to fit the estimation data and successfully predict new, independent validation data

  10. Singularity hypotheses a scientific and philosophical assessment

    Moor, James; Søraker, Johnny; Steinhart, Eric

    2012-01-01

    Singularity Hypotheses: A Scientific and Philosophical Assessment offers authoritative, jargon-free essays and critical commentaries on accelerating technological progress and the notion of technological singularity. It focuses on conjectures about the intelligence explosion, transhumanism, and whole brain emulation. Recent years have seen a plethora of forecasts about the profound, disruptive impact that is likely to result from further progress in these areas. Many commentators however doubt the scientific rigor of these forecasts, rejecting them as speculative and unfounded. We therefore invited prominent computer scientists, physicists, philosophers, biologists, economists and other thinkers to assess the singularity hypotheses. Their contributions go beyond speculation, providing deep insights into the main issues and a balanced picture of the debate.

  11. Current activities at the FiR 1 TRIGA reactor

    The FiR 1 -reactor, a 250 kW Triga reactor, has been in operation since 1962. The main purpose to run the reactor is now the Boron Neutron Capture Therapy (BNCT). The epithermal neutrons needed for the irradiation of brain tumor patients are produced from the fast fission neutrons by a moderator block consisting of Al+AlF3 (FLUENTAL), which showed to be the optimum material for this purpose. Twenty-one patients have been treated since May 1999, when the license for patient treatment was granted to the responsible BNCT treatment organization. The treatment organization has a close connection to the Helsinki University Central Hospital. The BNCT work dominates the current utilization of the reactor: three days per week for BNCT purposes and only two days per week for other purposes such as the neutron activation analysis and isotope production. In the near future the back end solutions of the spent fuel management will have a very important role in our activities. The Finnish Parliament ratified in May 2001 the Decision in Principle on the final disposal facility for spent fuel in Olkiluoto, on the western coast of Finland. There is a special condition in our operating license. We have now about two years' time to achieve a binding agreement between VTT and the Nuclear Power Plant Companies about the possibility to use the final disposal facility of the Nuclear Power Plants for our spent fuel. If this will not happen, we have to make the agreement with the USDOE with the well-known time limits. At the moment it seems to be reasonable to prepare for both spent fuel management possibilities: the domestic final disposal and the return to the USA offered by USDOE. Because the cost estimates of the both possibilities are on the same order of magnitude, the future of the reactor itself will determine, which of the spent fuel policies will be obeyed. In a couple of years' time it will be seen, if the funding of the reactor and the incomes from the BNC treatments will cover

  12. Current radar responsive tag development activities at Sandia National Laboratories.

    Plummer, Kenneth W.; Ormesher, Richard C.

    2003-09-01

    Over the past ten years, Sandia has developed RF radar responsive tag systems and supporting technologies for various government agencies and industry partners. RF tags can function as RF transmitters or radar transponders that enable tagging, tracking, and location determination functions. Expertise in tag architecture, microwave and radar design, signal analysis and processing techniques, digital design, modeling and simulation, and testing have been directly applicable to these tag programs. In general, the radar responsive tag designs have emphasized low power, small package size, and the ability to be detected by the radar at long ranges. Recently, there has been an interest in using radar responsive tags for Blue Force tracking and Combat ID (CID). The main reason for this interest is to allow airborne surveillance radars to easily distinguish U.S. assets from those of opposing forces. A Blue Force tracking capability would add materially to situational awareness. Combat ID is also an issue, as evidenced by the fact that approximately one-quarter of all U.S. casualties in the Gulf War took the form of ground troops killed by friendly fire. Because the evolution of warfare in the intervening decade has made asymmetric warfare the norm rather than the exception, swarming engagements in which U.S. forces will be freely intermixed with opposing forces is a situation that must be anticipated. Increasing utilization of precision munitions can be expected to drive fires progressively closer to engaged allied troops at times when visual de-confliction is not an option. In view of these trends, it becomes increasingly important that U.S. ground forces have a widely proliferated all-weather radar responsive tag that communicates to all-weather surveillance. The purpose of this paper is to provide an overview of the recent, current, and future radar responsive research and development activities at Sandia National Laboratories that support both the Blue Force Tracking

  13. Nuclear fuel manufacturing. Current activities and prospects at INR Pitesti

    Development of the CANDU nuclear fuel is currently conducted world wide onto two principal directions: - increasing the service span of the current type of fuel and improving the efficiency of burnup in reactor; - reducing the costs of fuel manufacturing by improving the design and manufacturing technologies in condition of increasing fuel performance. In parallel, a research program, RAAN, is undergoing, concerning the development of advanced CANDU type fuels (SEU, RU, DUPIC, Th), aiming at reducing the overall costs per fuel cycle. In the INR TRIGA reactor a large number of experimental fuel elements manufactured in INR were irradiated under different conditions specific to the CANDU reactor operation. Post irradiation investigations both destructive and non-destructive were carried out in the hot cells at INR Pitesti. The experimental results were used in order to optimize and evaluate the fuel project, to check the fuel manufacturing technologies as well as to certify the computational codes. The local thermo-mechanical analyses by final element methods, modelling the SCC phenomenon, probabilistic evaluation of performance parameters of the fuel, constitute new directions in the modelling and developing computational code. The developed codes were submitted to a thorough validation process to comply with the quality assurance. The excellent results obtained in INR were confirmed by participation in the FUMEX International Exercises of computer code intercomparison, organized by IAEA Vienna. Progress was also recorded in establishing the behaviour of fuel elements failed during reactor operation and the effect their maintenance in the reactor core could have upon the power reactor operation. A system-expert variant was worked out able for a short term analysis of the decisions referring to removing the failing element at Cernavoda NPP. As advanced CANDU fuel is concerned, until now preliminary variants for a fuel bundle with 43 elements containing slightly

  14. Causes of bat fatalities at wind turbines: Hypotheses and predictions

    Cryan, P.M.; Barclay, R.M.R.

    2009-01-01

    Thousands of industrial-scale wind turbines are being built across the world each year to meet the growing demand for sustainable energy. Bats of certain species are dying at wind turbines in unprecedented numbers. Species of bats consistently affected by turbines tend to be those that rely on trees as roosts and most migrate long distances. Although considerable progress has been made in recent years toward better understanding the problem, the causes of bat fatalities at turbines remain unclear. In this synthesis, we review hypothesized causes of bat fatalities at turbines. Hypotheses of cause fall into 2 general categoriesproximate and ultimate. Proximate causes explain the direct means by which bats die at turbines and include collision with towers and rotating blades, and barotrauma. Ultimate causes explain why bats come close to turbines and include 3 general types: random collisions, coincidental collisions, and collisions that result from attraction of bats to turbines. The random collision hypothesis posits that interactions between bats and turbines are random events and that fatalities are representative of the bats present at a site. Coincidental hypotheses posit that certain aspects of bat distribution or behavior put them at risk of collision and include aggregation during migration and seasonal increases in flight activity associated with feeding or mating. A surprising number of attraction hypotheses suggest that bats might be attracted to turbines out of curiosity, misperception, or as potential feeding, roosting, flocking, and mating opportunities. Identifying, prioritizing, and testing hypothesized causes of bat collisions with wind turbines are vital steps toward developing practical solutions to the problem. ?? 2009 American Society of Mammalogists.

  15. Dental Hypotheses: Seeks to Publish Hypotheses from All Areas of Dentistry

    Edward F. Rossomando

    2010-07-01

    Full Text Available Starting a new open access journal in a rapid growing scientific panorama is a severe challenge. However, the first issue of dental hypotheses is now history and the even skeptics can appreciate that dental hypotheses is a success - it is a journal of high quality that provides an outlet for publication of articles that encourage readers to question dental paradigms. But dental hypotheses readers might have noticed that the majority of the articles published in the first issue of dental hypotheses concern clinical dentistry. However, dental hypotheses editors recognize that there are many other areas in dentistry that present challenges and that our readers may offer suggestions for their solution. Some of these challenges relate to: dental education; digital dental technology; teledentistry and access to dental care; dental practice issues, such as, dental office design, dental office management, the slow rate of acceptance of innovative technology in the dental office; and issues related to innovation and dental entrepreneurship including intellectual property protection. Nevertheless, the dental profession faces many challenges - in many areas - and with the publication of dental hypotheses our profession has a venue for presentation of possible solutions. If you have developed a hypothesis that might help, please share it with your colleagues. As many have noted, the intellectual power of the global village in which we now live is formidable. The internet has provided the technology to bring us together and dental hypotheses has provided the venue. Please use it. New radical, speculative and non-mainstream scientific ideas are always welcome.

  16. Constant conditional entropy and related hypotheses

    Constant entropy rate (conditional entropies must remain constant as the sequence length increases) and uniform information density (conditional probabilities must remain constant as the sequence length increases) are two information theoretic principles that are argued to underlie a wide range of linguistic phenomena. Here we revise the predictions of these principles in the light of Hilberg’s law on the scaling of conditional entropy in language and related laws. We show that constant entropy rate (CER) and two interpretations for uniform information density (UID), full UID and strong UID, are inconsistent with these laws. Strong UID implies CER but the reverse is not true. Full UID, a particular case of UID, leads to costly uncorrelated sequences that are totally unrealistic. We conclude that CER and its particular cases are incomplete hypotheses about the scaling of conditional entropies. (letter)

  17. Assessing hypotheses about nesting site occupancy dynamics

    Bled, Florent; Royle, J. Andrew; Cam, Emmanuelle

    2011-01-01

    Hypotheses about habitat selection developed in the evolutionary ecology framework assume that individuals, under some conditions, select breeding habitat based on expected fitness in different habitat. The relationship between habitat quality and fitness may be reflected by breeding success of individuals, which may in turn be used to assess habitat quality. Habitat quality may also be assessed via local density: if high-quality sites are preferentially used, high density may reflect high-quality habitat. Here we assessed whether site occupancy dynamics vary with site surrogates for habitat quality. We modeled nest site use probability in a seabird subcolony (the Black-legged Kittiwake, Rissa tridactyla) over a 20-year period. We estimated site persistence (an occupied site remains occupied from time t to t + 1) and colonization through two subprocesses: first colonization (site creation at the timescale of the study) and recolonization (a site is colonized again after being deserted). Our model explicitly incorporated site-specific and neighboring breeding success and conspecific density in the neighborhood. Our results provided evidence that reproductively "successful'' sites have a higher persistence probability than "unsuccessful'' ones. Analyses of site fidelity in marked birds and of survival probability showed that high site persistence predominantly reflects site fidelity, not immediate colonization by new owners after emigration or death of previous owners. There is a negative quadratic relationship between local density and persistence probability. First colonization probability decreases with density, whereas recolonization probability is constant. This highlights the importance of distinguishing initial colonization and recolonization to understand site occupancy. All dynamics varied positively with neighboring breeding success. We found evidence of a positive interaction between site-specific and neighboring breeding success. We addressed local

  18. A Laboratory Activity on the Eddy Current Brake

    Molina-Bolivar, J. A.; Abella-Palacios, A. J.

    2012-01-01

    The aim of this paper is to introduce a simple and low-cost experimental setup that can be used to study the eddy current brake, which considers the motion of a sliding magnet on an inclined conducting plane in terms of basic physical principles. We present a set of quantitative experiments performed to study the influence of the geometrical and…

  19. Current distribution and magnetohydrodynamic activity in TEXTOR tokamak

    The plasma current distribution has been determined by the Faraday rotation method, especially inside the q = 1 radius. The profiles, sometimes of non monotonic slope at rational surfaces, are marginally stable to kink, and tearing mode instability, and are partially determined by transport related to the island structures or the periodic island ''reconnection'' processes. Report consists of 21 viewgraphs

  20. Get Current: Switch on Clean Energy Activity Book

    None

    2014-06-01

    Switching on clean energy technologies means strengthening the economy while protecting the environment. This activity book for all ages promotes energy awareness, with facts on different types of energy and a variety of puzzles in an energy theme.

  1. Specific activity 137Cs at fishes of Ukraine current state

    Specific activity of 137Cs at fishes of reservoirs of 30 kilometers ChNPP zone (Pripyat river and its bays, lakes, cool-ing-pond of ChNPP, etc.), water basins of Dneprovsky cascade, Shatsky lakes and Black sea near town Sudak is investigated during 2010 - 2012. Levels of specific activity of 137Cs at fishes in many respects are defined by flowage of the reservoir. Normally, the flowage of the reservoir is more, the levels of specific activity of 137Cs at fishes are less. The greatest specific activity of 137Cs at fishes was registered in the north of Ukraine in closed and half-closed reservoirs of 30 kilometers ChNPP zone - to 32000 Bqk/kg. In the southern direction activity of 137Cs at fishes decreases from 4,8 to 78,5 Bq/kg in Kyiv water basin to 1 - 6 Bq/kg, in the Kahovsky water basin and to 0,6 - 1,9 Bq/kg in the Black sea. In large reservoirs the greatest specific activity of 137Cs, as a rule, is registered in fishes of the higher trophic levels

  2. Improving Industrial Energy Quality by an Active Current Filter

    Reyes–Trujillo E; Rodríguez–Rivas J.J; Robles–García J.

    2010-01-01

    The growing number of non-linear loads on industrial applications has produced an important impact on the quality of electric power supply due to the increasing of the voltage and current harmonic distortion, and low power factor. In order to solve this, arrangements of capacitors and reactors, known as passive filters have been used. However these filters may produce resonance problems with network impedance, over compensation of reactive power at fundamental frequency, and poor flexibility ...

  3. Limits on hypothesizing new quantum numbers

    According to a recent theorem, for a general quantum-mechanical system undergoing a process, one can tell from measurements on this system whether or not it is characterized by a quantum number, the existence of which is unknown to the observer, even though the detecting equipment used by the observer is unable to distinguish among the various possible values of the ''secret'' quantum number and hence always averages over them. The present paper deals with situations in which this averaging is avoided and hence the ''secret'' quantum number remains ''secret.'' This occurs when a new quantum number is hypothesized in such a way that all the past measurements pertain to the system with one and the same value of the ''secret'' quantum number, or when the new quantum number is related to the old ones by a specific dynamical model providing a one-to-one correspondence. In the first of these cases, however, the one and the same state of the ''secret'' quantum number needs to be a nondegenerate one. If it is degenerate, the theorem can again be applied. This last feature provides a tool for experimentally testing symmetry breaking and the reestablishment of symmetries in asymptotic regions. The situation is illustrated on historical examples like isospin and strangeness, as well as on some contemporary schemes involving spaces of higher dimensionality

  4. Ensemble evaluation of hydrological model hypotheses

    Krueger, Tobias; Freer, Jim; Quinton, John N.; MacLeod, Christopher J. A.; Bilotta, Gary S.; Brazier, Richard E.; Butler, Patricia; Haygarth, Philip M.

    2010-07-01

    It is demonstrated for the first time how model parameter, structural and data uncertainties can be accounted for explicitly and simultaneously within the Generalized Likelihood Uncertainty Estimation (GLUE) methodology. As an example application, 72 variants of a single soil moisture accounting store are tested as simplified hypotheses of runoff generation at six experimental grassland field-scale lysimeters through model rejection and a novel diagnostic scheme. The fields, designed as replicates, exhibit different hydrological behaviors which yield different model performances. For fields with low initial discharge levels at the beginning of events, the conceptual stores considered reach their limit of applicability. Conversely, one of the fields yielding more discharge than the others, but having larger data gaps, allows for greater flexibility in the choice of model structures. As a model learning exercise, the study points to a "leaking" of the fields not evident from previous field experiments. It is discussed how understanding observational uncertainties and incorporating these into model diagnostics can help appreciate the scale of model structural error.

  5. Current activities on safety improvement at Ukrainian NPPs

    This report describes general development status of the national programs on safety improvement of the Ukrainian NPPs, basic approaches adopted for planning and implementation of safety improvement works, and state of implementation of principal technical activities aimed at safety improvement of Ukrainian NPPs. (author)

  6. Teacher Feedback during Active Learning: Current Practices in Primary Schools

    van den Bergh, Linda; Ros, Anje; Beijaard, Douwe

    2013-01-01

    Background: Feedback is one of the most powerful tools, which teachers can use to enhance student learning. It appears dif?cult for teachers to give qualitatively good feedback, especially during active learning. In this context, teachers should provide facilitative feedback that is focused on the development of meta-cognition and social learning.…

  7. Icing Branch Current Research Activities in Icing Physics

    Vargas, Mario

    2009-01-01

    Current development: A grid block transformation scheme which allows the input of grids in arbitrary reference frames, the use of mirror planes, and grids with relative velocities has been developed. A simple ice crystal and sand particle bouncing scheme has been included. Added an SLD splashing model based on that developed by William Wright for the LEWICE 3.2.2 software. A new area based collection efficiency algorithm will be incorporated which calculates trajectories from inflow block boundaries to outflow block boundaries. This method will be used for calculating and passing collection efficiency data between blade rows for turbo-machinery calculations.

  8. Wall conditioning for ITER: Current experimental and modeling activities

    Douai, D., E-mail: david.douai@cea.fr [CEA, IRFM, Association Euratom-CEA, 13108 St. Paul lez Durance (France); Kogut, D. [CEA, IRFM, Association Euratom-CEA, 13108 St. Paul lez Durance (France); Wauters, T. [LPP-ERM/KMS, Association Belgian State, 1000 Brussels (Belgium); Brezinsek, S. [FZJ, Institut für Energie- und Klimaforschung Plasmaphysik, 52441 Jülich (Germany); Hagelaar, G.J.M. [Laboratoire Plasma et Conversion d’Energie, UMR5213, Toulouse (France); Hong, S.H. [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Lomas, P.J. [CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Lyssoivan, A. [LPP-ERM/KMS, Association Belgian State, 1000 Brussels (Belgium); Nunes, I. [Associação EURATOM-IST, Instituto de Plasmas e Fusão Nuclear, 1049-001 Lisboa (Portugal); Pitts, R.A. [ITER International Organization, F-13067 St. Paul lez Durance (France); Rohde, V. [Max-Planck-Institut für Plasmaphysik, 85748 Garching (Germany); Vries, P.C. de [ITER International Organization, F-13067 St. Paul lez Durance (France)

    2015-08-15

    Wall conditioning will be required in ITER to control fuel and impurity recycling, as well as tritium (T) inventory. Analysis of conditioning cycle on the JET, with its ITER-Like Wall is presented, evidencing reduced need for wall cleaning in ITER compared to JET–CFC. Using a novel 2D multi-fluid model, current density during Glow Discharge Conditioning (GDC) on the in-vessel plasma-facing components (PFC) of ITER is predicted to approach the simple expectation of total anode current divided by wall surface area. Baking of the divertor to 350 °C should desorb the majority of the co-deposited T. ITER foresees the use of low temperature plasma based techniques compatible with the permanent toroidal magnetic field, such as Ion (ICWC) or Electron Cyclotron Wall Conditioning (ECWC), for tritium removal between ITER plasma pulses. Extrapolation of JET ICWC results to ITER indicates removal comparable to estimated T-retention in nominal ITER D:T shots, whereas GDC may be unattractive for that purpose.

  9. Bactericidal activity of high voltage pulsed current (HVPC in vitro

    Kramer, Axel

    2006-08-01

    Full Text Available The positive effect of electrical stimulation (ES on wound healing has been shown in vitro and in vivo. Based on increased blood flow, protein denaturation and stimulation of cellular defence, an antibacterial effect of ES is to be expected. Although the antibacterial effect of ES already has been demonstrated in vitro, little attention has been paid to the direct antibacterial effect of changing polarity of the applied current. The aim of this study was to investigate the antibacterial effect of positive and negative monophasic high voltage pulsed current (HVPV on typical gram positive and gram negative pathogens of chronic wounds.Using the WoundEL®-System, three gram negative (E. coli, P. aeruginosa, K. pneumoniae and three gram positive (S. aureus, S. epidermidis, E. faecium organisms were tested against positive and negative polarity HVPV. All tested organisms were significantly (P < 0.01 reduced by ES. The reduction differed significantly (P = 0.02 between positive and negative polarity, with the highest log10 RF achieved with positive polarity. Using positive polarity, the maximum RF was measured for Escherichia coli (median log10 RF 0.83; 25th percentile 0.59, 75th percentile 0.98, the lowest for Staphylococcus epidermidis (median log10 RF 0.20; 25th percentile 0.17, 75th percentile 0.24. Yet, there was no significant difference with positive ES against gram positive (P = 0.35 or gram negative (P = 0.71 organisms.

  10. Wall conditioning for ITER: Current experimental and modeling activities

    Wall conditioning will be required in ITER to control fuel and impurity recycling, as well as tritium (T) inventory. Analysis of conditioning cycle on the JET, with its ITER-Like Wall is presented, evidencing reduced need for wall cleaning in ITER compared to JET–CFC. Using a novel 2D multi-fluid model, current density during Glow Discharge Conditioning (GDC) on the in-vessel plasma-facing components (PFC) of ITER is predicted to approach the simple expectation of total anode current divided by wall surface area. Baking of the divertor to 350 °C should desorb the majority of the co-deposited T. ITER foresees the use of low temperature plasma based techniques compatible with the permanent toroidal magnetic field, such as Ion (ICWC) or Electron Cyclotron Wall Conditioning (ECWC), for tritium removal between ITER plasma pulses. Extrapolation of JET ICWC results to ITER indicates removal comparable to estimated T-retention in nominal ITER D:T shots, whereas GDC may be unattractive for that purpose

  11. Current activities of the Yersinia effector protein YopM.

    Höfling, Sabrina; Grabowski, Benjamin; Norkowski, Stefanie; Schmidt, M Alexander; Rüter, Christian

    2015-05-01

    Yersinia outer protein M (YopM) belongs to the group of Yop effector proteins, which are highly conserved among pathogenic Yersinia species. During infection, the effectors are delivered into the host cell cytoplasm via the type 3 secretion system to subvert the host immune response and support the survival of Yersinia. In contrast to the other Yop effectors, YopM does not possess a known enzymatic activity and its molecular mechanism(s) of action remain(s) poorly understood. However, YopM was shown to promote colonization and dissemination of Yersinia, thus being crucial for the pathogen's virulence in vivo. Moreover, YopM interacts with several host cell proteins and might utilize them to execute its anti-inflammatory activities. The results obtained so far indicate that YopM is a multifunctional protein that counteracts the host immune defense by multiple activities, which are at least partially independent of each other. Finally, its functions seem to be also influenced by differences between the specific YopM isoforms expressed by Yersinia subspecies. In this review, we focus on the global as well as more specific contribution of YopM to virulence of Yersinia during infection and point out the various extra- and intracellular molecular functions of YopM. In addition, the novel cell-penetrating ability of recombinant YopM and its potential applications as a self-delivering immunomodulatory therapeutic will be discussed. PMID:25865799

  12. RSG-GAS. Current and strategic plan of future activities

    The Multi Purpose Reactor G.A. Siwabessy, so-called RSG-GAS, is the third research reactor built in Indonesia and operated by National Nuclear Energy of Indonesia (BATAN). This MTR type reactor achieved its first criticality in July 1987. Since then it has been operated about 77.300 hours. It uses LEU fuel in the form of U3O8-Al at the beginning, but then converted to silicide fuel, U3Si2-Al by a density of 2.96 g/cm3 preserving its nominal power of 30 MW and average flux of 2.5x1014 n/cm2 sec. In the last two years the reactor is operated more than 3.500 hours per year. Several equipments have been refurbished due to ageing. The reactor is operated mainly for serving radioisotopes production, neutron activation analysis (NAA), neutron beam experiments and general irradiation for research and development activities. The future activities of the RSG-GAS reactor will be prioritized first on increasing the reliability and availability of the reactor operation to assure the fulfillment of the demand of the isotope production, along with the improvement of neutron beam instruments and NAA facilities to increase its utilization. In this context, the collaboration in the utilization of RSG-GAS for many application with the countries in the region is also expected. The human resource development for the new recruited RSG-GAS staff is also a challenge and become a priority. (author)

  13. Ant Abundance along a Productivity Gradient: Addressing Two Conflicting Hypotheses.

    Udi Segev

    Full Text Available The number of individuals within a population or community and their body size can be associated with changes in resource supply. While these relationships may provide a key to better understand the role of abiotic vs. biotic constraints in animal communities, little is known about the way size and abundance of organisms change along resource gradients. Here, we studied this interplay in ants, addressing two hypotheses with opposite predictions regarding variation in population densities along resource gradients- the 'productivity hypothesis' and the 'productivity-based thinning hypothesis'. The hypotheses were tested in two functional groups of ground-dwelling ants that are directly primary consumers feeding on seeds: specialized seed-eaters and generalist species. We examined variations in colony density and foraging activity (a size measurement of the forager caste in six ant assemblages along a steep productivity gradient in a semi-arid region, where precipitation and plant biomass vary 6-fold over a distance of 250km. An increase in the density or foraging activity of ant colonies along productivity gradients is also likely to affect competitive interactions among colonies, and consequently clinal changes in competition intensity were also examined. Ant foraging activity increased with productivity for both functional groups. However, colony density revealed opposing patterns: it increased with productivity for the specialized seed-eaters, but decreased for the generalist species. Competition intensity, evaluated by spatial partitioning of species at food baits and distribution of colonies, was uncorrelated with productivity in the specialized seed-eaters, but decreased with increasing productivity in the generalists. Our results provide support for two contrasting hypotheses regarding the effect of resource availability on the abundance of colonial organisms- the 'productivity hypothesis' for specialized seed-eaters and the 'productivity

  14. Ant Abundance along a Productivity Gradient: Addressing Two Conflicting Hypotheses.

    Segev, Udi; Kigel, Jaime; Lubin, Yael; Tielbörger, Katja

    2015-01-01

    The number of individuals within a population or community and their body size can be associated with changes in resource supply. While these relationships may provide a key to better understand the role of abiotic vs. biotic constraints in animal communities, little is known about the way size and abundance of organisms change along resource gradients. Here, we studied this interplay in ants, addressing two hypotheses with opposite predictions regarding variation in population densities along resource gradients- the 'productivity hypothesis' and the 'productivity-based thinning hypothesis'. The hypotheses were tested in two functional groups of ground-dwelling ants that are directly primary consumers feeding on seeds: specialized seed-eaters and generalist species. We examined variations in colony density and foraging activity (a size measurement of the forager caste) in six ant assemblages along a steep productivity gradient in a semi-arid region, where precipitation and plant biomass vary 6-fold over a distance of 250km. An increase in the density or foraging activity of ant colonies along productivity gradients is also likely to affect competitive interactions among colonies, and consequently clinal changes in competition intensity were also examined. Ant foraging activity increased with productivity for both functional groups. However, colony density revealed opposing patterns: it increased with productivity for the specialized seed-eaters, but decreased for the generalist species. Competition intensity, evaluated by spatial partitioning of species at food baits and distribution of colonies, was uncorrelated with productivity in the specialized seed-eaters, but decreased with increasing productivity in the generalists. Our results provide support for two contrasting hypotheses regarding the effect of resource availability on the abundance of colonial organisms- the 'productivity hypothesis' for specialized seed-eaters and the 'productivity-based thinning

  15. A laboratory activity on the eddy current brake

    The aim of this paper is to introduce a simple and low-cost experimental setup that can be used to study the eddy current brake, which considers the motion of a sliding magnet on an inclined conducting plane in terms of basic physical principles. We present a set of quantitative experiments performed to study the influence of the geometrical and electromagnetic properties of the magnet on the magnetic drag force. This video-based experiment is ideal for the study of kinematic graphs and the application of Newton's laws. Video motion analysis software enables students to make precise measurements of the magnet's position at incremental times during its motion, thus allowing them to quantify electromagnetic induction phenomena. The equipment needed for this experiment and data collection software are present in most physics teaching laboratories or are inexpensive and available. (paper)

  16. Current status of neutron activation analysis in HANARO Research Reactor

    The facilities for neutron activation analysis in the HANARO (Hi-flux Advanced Neutron Application Research Reactor) are described and the main applications of NAA (Neutron Activation Analysis) are reviewed. The sample irradiation tube, automatic and manual pneumatic transfer system were installed at three irradiation holes of HANARO at the end of 1995. The performance of the NAA facility was examined to identify the characteristics of the tube transfer system, irradiation sites and custom-made polyethylene irradiation capsule. The available thermal neutron fluxes at irradiation sites are in the range of 3 x 1013 - 1 x 1014 n/cm2·s and cadmium ratios are in 15 - 250. For an automatic sample changer for gamma-ray counting, a domestic product was designed and manufactured. An integrated computer program (Labview) to analyse the content was developed. In 2001, PGNAA (Prompt Gamma Neutron Activation Analysis) facility has been installed using a diffracted neutron beam of ST1. NAA has been applied in the trace component analysis of nuclear, geological, biological, environmental and high purity materials, and various polymers for research and development. The improvement of analytical procedures and establishment of an analytical quality control and assurance system were studied. Applied research and development for the environment, industry and human health by NAA and its standardization were carried out. For the application of the KOLAS (Korea Laboratory Accreditation Scheme), evaluation of measurement uncertainty and proficiency testing of reference materials were performed. Also to verify the reliability and to validate analytical results, intercomparison studies between laboratories were carried out. (author)

  17. Current status of neutron activation analysis in HANARO Research Reactor

    Chung, Yong Sam; Moon, Jong Hwa; Sohn, Jae Min [Korea Atomic Energy Research Institute, Daejeon (Korea)

    2003-03-01

    The facilities for neutron activation analysis in the HANARO (Hi-flux Advanced Neutron Application Research Reactor) are described and the main applications of NAA (Neutron Activation Analysis) are reviewed. The sample irradiation tube, automatic and manual pneumatic transfer system were installed at three irradiation holes of HANARO at the end of 1995. The performance of the NAA facility was examined to identify the characteristics of the tube transfer system, irradiation sites and custom-made polyethylene irradiation capsule. The available thermal neutron fluxes at irradiation sites are in the range of 3 x 10{sup 13} - 1 x 10{sup 14} n/cm{sup 2}{center_dot}s and cadmium ratios are in 15 - 250. For an automatic sample changer for gamma-ray counting, a domestic product was designed and manufactured. An integrated computer program (Labview) to analyse the content was developed. In 2001, PGNAA (Prompt Gamma Neutron Activation Analysis) facility has been installed using a diffracted neutron beam of ST1. NAA has been applied in the trace component analysis of nuclear, geological, biological, environmental and high purity materials, and various polymers for research and development. The improvement of analytical procedures and establishment of an analytical quality control and assurance system were studied. Applied research and development for the environment, industry and human health by NAA and its standardization were carried out. For the application of the KOLAS (Korea Laboratory Accreditation Scheme), evaluation of measurement uncertainty and proficiency testing of reference materials were performed. Also to verify the reliability and to validate analytical results, intercomparison studies between laboratories were carried out. (author)

  18. Hypotheses on the functional roles of chaotic transitory dynamics

    Tsuda, Ichiro

    2009-03-01

    In contrast to the conventional static view of the brain, recent experimental data show that an alternative view is necessary for an appropriate interpretation of its function. Some selected problems concerning the cortical transitory dynamics are discussed. For the first time, we propose five scenarios for the appearance of chaotic itinerancy, which provides typical transitory dynamics. Second, we describe the transitory behaviors that have been observed in human and animal brains. Finally, we propose nine hypotheses on the functional roles of such dynamics, focusing on the dynamics embedded in data and the dynamical interpretation of brain activity within the framework of cerebral hermeneutics.

  19. Current activities of post-irradiation examination at KAERI

    A wide range of post-irradiation examination (PIE) for the nuclear fuels irradiated at NPPs with different design characteristics have been carried out at PIEF at KAERI. The examination was conducted to evaluate the irradiation performances as well as the fuel integrities. The input data leading to the design upgrades of the nuclear fuels have mostly been obtained from the PIE of the irradiated fuels. A comprehensive non-destructive and destructive examination equipment are incorporated with the hot cell examination system. The main activity of PIEF is concentrated on the commercial nuclear fuel examination as the IMEF focused on the HANARO irradiated fuel and material examination. Recently, the above mentioned two facilities put great concentrations on the examination of the structural components of the fuel assembly such as skeleton, spacer grid and hold down spring elements to cope with the safety requirements of fuel integrities to meet a highly extended burn up conditions. In this paper, a brief and general activity of the both facilities and the future scope of work are introduced. (author)

  20. Current status of active tests at Rokkasho reprocessing plant

    At Rokkasho Reprocessing Plant (RRP), the first commercial reprocessing plant in Japan, the test operation has been carried out step by step with 'water and steam', 'chemical products', 'depleted uranium' and 'spent fuels' toward the planned start of the commercial operation. Water Test was performed as the final stage of plant construction work and functioning of each equipment was tested with water and steam. In Chemical Test the performance of each equipment and unit was verified with chemical products such as nitric acid. In Uranium Test with depleted uranium, function and performance of equipment such as the sharing machine and the dissolver was verified. All its tests were completed by 22 January 2006. Active Test has been performed with spent fuels for the verification of safety functions and performances of equipment and facilities related to the processing of fission products and of plutonium, which had not been tested previously. Active Test which has been in progress since 31 March 2006 is divided into 5 steps, and Step 1, Step 2 and Step 3 are already completed. (authors)

  1. Current research and service activities of AFRRI's biological dosimetry program

    Full text: The long-range goal of the Armed Forces Radiobiology Research Institute's (AFRRI) Biological Dosimetry Team is to develop validated radiation bio dosimeters. Our objectives are (1) to establish definitive clinical bioassays for rapid, high-throughput radiation exposure analyses and (2) to develop complimentary triage-type radiation exposure assessment bioassays to support medical treatment decisions. The experimental approach involves two steps. The first is to establish a reference laboratory that uses conventional bioassays for definitive analyses of biological samples. The second step is to develop a validated and forward deployable biological dosimetry capability for rapid radiation dose assessment with an emphasis on the use of molecular biology-based diagnostic platforms. The conventional lymphocyte metaphase-spread dicentric assay was established at AFRRI in accordance with international harmonized protocols and applied to estimate radiation exposure doses in several overexposure accidents. Currently, novel interphase cell-based cytological bioassay that detects cells with chromosomal type aberrations and radiation responsive molecular bio markers (i.e., gene expression, protein) are being validated and optimized for rapid radiation exposure assessment applications. In addition the Biological Assessment Tool (BAT), a radiation casualty management software application, was developed. Available at AFRRI's website (www.afrri.usuhs.mil), BAT permits the recording and communication of relevant radiological and medical information for radiation accidents. These research and service efforts contribute to an improved diagnostic response for accidental overexposures and also have applications in other research fields including radiation therapy and toxicology

  2. Current activities of safety improvements at Ukrainian NPPs

    The basic idea leading the program of safety improvements at Ukrainian NPPs is further development of nuclear power required to ensure at least 40% of country's energy supply. Activities concerning safety improvements of Ukrainian NPPs involved four reactor types: WWER-1000 (V-5) large series, WWER-1000 (V-302, V-338) small series, WWER-400 (V-213) and RBMK (second generation). Most significant safety improvements covered reactor core integrity, reactor components and cooling systems integrity, instrumentation and control system, power supply, internal hazards. Additional measures related to WWER-440 were concerned with feedwater supply, instrumentation and control systems, and containment. Improvements related to Chernobylsk NPP unit 3 involved supervision, control and protection systems; safety assessment and supporting systems; fire safety. The role of quality assurance and training is emphasised when operational safety is concerned. Planned safety upgrading measures are mentioned

  3. Testing Hypotheses About Glacial Cycles Against the Observational Record

    Kaufmann, Robert; Juselius, Katarina

    2013-01-01

    biological activity reduces CO2 concentrations. Glacial variations in ice volume, as proxied by are driven by changes in CO2 concentrations, global and high latitude solar insolation, latitudinal gradients in solar insolation, and the atmospheric concentration of CO2. The model is able to quantify the......We estimate an identified cointegrated vector autoregression (CVAR) model of the climate system to test hypotheses about the physical mechanisms that may drive glacial cycles during the late Pleistocene. Results indicate that a permanent doubling of CO2 generates a 11.1oC rise in Antarctic...... temeprature. Large variations in atmospheric CO2 over glacial cycles are driven by changes in sea ice and sea surface temperature in southern oceans and marine biological activity. The latter can be represented by a two-step process in which iron dust increases biological activity and the increase in...

  4. Profiles for voltage-activated currents are multiphasic, not curvilinear

    Nissen, Per

    2016-01-01

    Data for voltage-activation of a potassium channel (Matulef et al. Proc Natl Acad Sci USA 110: 17886-17891. 2013) were, as conventionally done, fitted by the authors by a Boltzmann function, i.e. by a curvilinear profile. Reanalysis of the data reveals however that this interpretation must be rejected in favor of a multiphasic profile, a series of straight lines separated by discontinuous transitions, quite often in the form of noncontiguities (jumps). In contrast to the generally very poor fits to the Boltzmann profiles, the fits to multiphasic profiles are very good. (For the four replicates, the average deviations from the Boltzmann curves were 10- to 100-fold larger than the deviations from the multiphasic profiles.) The difference in the median values was statistically highly significant, P<0.001 in most cases. For the mean values the deviations from the Boltzmann curve were 20-fold larger than the deviations from the multiphasic profile, and the difference in the median values was also highly signifi...

  5. Current trends in the structure-activity relationships of sialyltransferases.

    Audry, Magali; Jeanneau, Charlotte; Imberty, Anne; Harduin-Lepers, Anne; Delannoy, Philippe; Breton, Christelle

    2011-06-01

    Sialyltransferases (STs) represent an important group of enzymes that transfer N-acetylneuraminic acid (Neu5Ac) from cytidine monophosphate-Neu5Ac to various acceptor substrates. In higher animals, sialylated oligosaccharide structures play crucial roles in many biological processes but also in diseases, notably in microbial infection and cancer. Cell surface sialic acids have also been found in a few microorganisms, mainly pathogenic bacteria, and their presence is often associated with virulence. STs are distributed into five different families in the CAZy database (http://www.cazy.org/). On the basis of crystallographic data available for three ST families and fold recognition analysis for the two other families, STs can be grouped into two structural superfamilies that represent variations of the canonical glycosyltransferase (GT-A and GT-B) folds. These two superfamilies differ in the nature of their active site residues, notably the catalytic base (a histidine or an aspartate residue). The observed structural and functional differences strongly suggest that these two structural superfamilies have evolved independently. PMID:21098518

  6. Overview of current Russian activities in P and T area

    The general policy of radioactive waste management is consistent with the long-term plans for nuclear power development adopted in each country. Russian activities aimed at setting up in the future a fuel cycle of nuclear power with reasonably minimized quantities of Radwaste subject disposal are being carried out by Minatom as part of the general Strategy for development of national nuclear power. Several key missions of this Strategy deserve special mention: in the next 20-40 years, construction of advanced thermal reactors which will run on enriched uranium until the economically acceptable reserves of natural uranium are exhausted; reprocessing of all spent fuel of thermal reactors to separate plutonium and long-lived nuclides; development of a new generation of fast reactors which will meet the requirements placed on innovative reactors for large-scale electricity production (economic efficiency, safety, minimized Radwaste, proliferation resistance); after 2030, deployment of a system of innovative fast reactors, using plutonium separated from spent fuel of thermal reactors, and solution with their help of the totality of problems associated with transmutation of long-lived nuclides. Task named ''Transmutation'' was set up in 2001, within the general Minatom programme, to develop a scenario for transition to the fuel cycle of future large-scale nuclear power as part of the above Strategy and to resolve the technological problems of minimising the quantities of long-lived nuclides generated in the closed fuel cycle and subject to final disposal. (author)

  7. Dysfunctional amygdala activation and connectivity with the prefrontal cortex in current cocaine users

    Crunelle, C.L.; Kaag, A.M.; Munkhof, H.E. van den; Reneman, L.; Homberg, J.R.; Sabbe, B.; Brink, W. van den; Wingen, G. van

    2015-01-01

    OBJECTIVES: Stimulant use is associated with increased anxiety and a single administration of dexamphetamine increases amygdala activation to biologically salient stimuli in healthy individuals. Here, we investigate how current cocaine use affects amygdala activity and amygdala connectivity with the

  8. Action-related auditory ERP attenuation: Paradigms and hypotheses.

    Horváth, János

    2015-11-11

    A number studies have shown that the auditory N1 event-related potential (ERP) is attenuated when elicited by self-induced or self-generated sounds. Because N1 is a correlate of auditory feature- and event-detection, it was generally assumed that N1-attenuation reflected the cancellation of auditory re-afference, enabled by the internal forward modeling of the predictable sensory consequences of the given action. Focusing on paradigms utilizing non-speech actions, the present review summarizes recent progress on action-related auditory attenuation. Following a critical analysis of the most widely used, contingent paradigm, two further hypotheses on the possible causes of action-related auditory ERP attenuation are presented. The attention hypotheses suggest that auditory ERP attenuation is brought about by a temporary division of attention between the action and the auditory stimulation. The pre-activation hypothesis suggests that the attenuation is caused by the activation of a sensory template during the initiation of the action, which interferes with the incoming stimulation. Although each hypothesis can account for a number of findings, none of them can accommodate the whole spectrum of results. It is suggested that a better understanding of auditory ERP attenuation phenomena could be achieved by systematic investigations of the types of actions, the degree of action-effect contingency, and the temporal characteristics of action-effect contingency representation-buildup and -deactivation. This article is part of a Special Issue entitled SI: Prediction and Attention. PMID:25843932

  9. Testing Alternative Hypotheses about Animal Behavior.

    Baker, William P.; Lang, Michael; Lawson, Anton E.

    Research indicates that the effectiveness of instruction in the elementary classroom is enhanced when it incorporates materials that actively engage students in the generation of scientific explanations. To this end, this document describes an exercise that allows Kindergarten students to explore the basic principles of animal behavior in an…

  10. How the mainstream limits the spreading of alternative hypotheses

    Kalenda, Pavel

    2014-05-01

    that prof. Djuric had tried for more than 10 years to publish this article in various peer-reviewed journals. So, prof. Djuric got into the official book (list) of "scientific dissidents" among hundreds of other professors and doctors of science (De Climont 2012). These "scientific dissidents" do not have access to established journals and may possibly publish privately or at best on the web in marginal journals whose list was published by De Climont (2012). Such a marginal journal in the field of geophysics and geology is New Concepts in Global Tectonics. This journal has been established because the current hypothesis about the movement of the continents due to convection currents in the mantle becomes under the weight of new observation quite untenable. 4) Scientific consensus History has known many hypotheses that were accepted as proven truth but later, in the light of new knowledge, they completely failed. - No one has the right to decide which scientific hypotheses will be accepted and which will not get into print. Perhaps the worst situation is in climatology (due to global effects and impacts), when the plenary session of IPCC consensually stated that the current global warming was mainly due to the human activity. References De Climont, J. (2012): The worldwide list of dissident scientists. http://astrojan.hostei.com/droa.htm. Djurič, J. (2006): Unification Of Gravitation And Electromagnetism. http://jovandjuric.tripod.com/ David H. Douglass, John R. Christy, Benjamin D. Pearson and S. Fred Singer (2007): A comparison of tropical temperature trends with model predictions. International Journal of Climatology, Volume 28, Issue 13, 15 November 2008, Pages: 1693-1701. http://onlinelibrary.wiley.com/doi/10.1002/joc.1651/pdf. Einstein, A. : List of scientific publications by Albert Einstein. /wiki/List_of_scientific_publications_by_Albert_Einstein. Kolínský, P., Valenta, J. and Gaždová, R. (2012): Seismicity, groundwater level variations and earth tides in

  11. How the mainstream limits the spreading of alternative hypotheses

    Kalenda, Pavel

    2014-05-01

    that prof. Djuric had tried for more than 10 years to publish this article in various peer-reviewed journals. So, prof. Djuric got into the official book (list) of "scientific dissidents" among hundreds of other professors and doctors of science (De Climont 2012). These "scientific dissidents" do not have access to established journals and may possibly publish privately or at best on the web in marginal journals whose list was published by De Climont (2012). Such a marginal journal in the field of geophysics and geology is New Concepts in Global Tectonics. This journal has been established because the current hypothesis about the movement of the continents due to convection currents in the mantle becomes under the weight of new observation quite untenable. 4) Scientific consensus History has known many hypotheses that were accepted as proven truth but later, in the light of new knowledge, they completely failed. - No one has the right to decide which scientific hypotheses will be accepted and which will not get into print. Perhaps the worst situation is in climatology (due to global effects and impacts), when the plenary session of IPCC consensually stated that the current global warming was mainly due to the human activity. References De Climont, J. (2012): The worldwide list of dissident scientists. http://astrojan.hostei.com/droa.htm. Djurič, J. (2006): Unification Of Gravitation And Electromagnetism. http://jovandjuric.tripod.com/ David H. Douglass, John R. Christy, Benjamin D. Pearson and S. Fred Singer (2007): A comparison of tropical temperature trends with model predictions. International Journal of Climatology, Volume 28, Issue 13, 15 November 2008, Pages: 1693-1701. http://onlinelibrary.wiley.com/doi/10.1002/joc.1651/pdf. Einstein, A. : List of scientific publications by Albert Einstein. /wiki/List_of_scientific_publications_by_Albert_Einstein. Kolínský, P., Valenta, J. and Gaždová, R. (2012): Seismicity, groundwater level variations and earth tides in

  12. How Journalists Describe Their Stories: Hypotheses and Assumptions in Newsmaking.

    Stocking, S. Holly; LaMarca, Nancy

    1990-01-01

    Interviews newspaper reporters to show that journalists, like scientists, usually have hypotheses in mind in working a story. Finds, however, that unlike those of scientists, journalists' hypotheses were both explicit and implicit. (MG)

  13. The Innovative Construction of Team Culture in the Hypothesized Organization

    Li Song

    2009-01-01

    Along with the globalization and the technological advancement, more hypothesized organization as well as hypothesized enterprises of more forms will appear. This article mainly analyzes the innovative construction of team culture in the hypothesized organization, and it explores in every detail the construction of team culture from five aspects: the team role transformation in the hypothesized organization’s team culture, the member coordination, the knowledge management, the study efficienc...

  14. Psychohistorical Hypotheses on Japan's History of Hostility Towards China.

    Wang, Bo; Rudmin, Floyd

    2016-01-01

    The accelerating tensions and military posturing between Japan and China have created a serious crisis with a danger of a catastrophic war. The purpose of this paper is to summarize the events of the current crisis, and to put it in the context of Japan's long history of hostility to China and repeated attempts at conquest. The historical record shows that Japan has attacked China at least seven times, even though China has never attacked Japan. The irrationality of Japan's behavior is demonstrated by the repetition of this hostile behavior despite the enormous human and economic costs that Japan has suffered because of it. The irrationality of Japan's militarism suggests that psychological explanations may be required to understand this phenomenon. Several hypotheses are proposed, including 1) projected paranoid aggression, 2) collective Zeigarnik compulsion, 3) perceived weakness exciting aggression, 4) national inferiority feelings, 5) cultural narcissism, and 6) Oedipal-like hatred of a parent culture. PMID:27480012

  15. "Caged calcium" in Aplysia pacemaker neurons. Characterization of calcium-activated potassium and nonspecific cation currents

    1989-01-01

    We have studied calcium-activated potassium current, IK(Ca), and calcium-activated nonspecific cation current, INS(Ca), in Aplysia bursting pacemaker neurons, using photolysis of a calcium chelator (nitr-5 or nitr-7) to release "caged calcium" intracellularly. A computer model of nitr photolysis, multiple buffer equilibration, and active calcium extrusion was developed to predict volume-average and front-surface calcium concentration transients. Changes in arsenazo III absorbance were used to...

  16. Photonic Network R&D Activities in Japan-Current Activities and Future Perspectives

    Kitayama, Ken-Ichi; Miki, Tetsuya; Morioka, Toshio; Tsushima, Hideaki; Koga, Masafumi; Mori, Kazuyuki; Araki, Soichiro; Sato, Ken-Ichi; Onaka, Hiroshi; Namiki, Shu; Aoyama, Tomonori

    2005-10-01

    R&D activities on photonic networks in Japan are presented. First, milestones in current ongoing R&D programs supported by Japanese government agencies are introduced, including long-distance and wavelength division multiplexing (WDM) fiber transmission, wavelength routing, optical burst switching (OBS), and control-plane technology for IP backbone networks. Their goal was set to evolve a legacy telecommunications network to IP-over-WDM networks by introducing technologies for WDM and wavelength routing. We then discuss the perspectives of so-called PHASE II R&D programs for photonic networks over the next 5 years until 2010, by focusing on the report that has been recently issued by the Photonic Internet Forum (PIF), a consortium that has major carriers, telecom vendors, and Japanese academics as members. The PHASE II R&D programs should serve to establish a photonic platform to provide abundant bandwidth on demand, at any time on a real-time basis, through the customer's initiative to promote bandwidth-rich applications, such as grid computing, real-time digital-cinema streaming, medical and educational applications, and network storage in e-commerce.

  17. A survey of etiologic hypotheses among testicular cancer researchers

    Stang, A; Trabert, B; Rusner, C;

    2015-01-01

    Basic research results can provide new ideas and hypotheses to be examined in epidemiological studies. We conducted a survey among testicular cancer researchers on hypotheses concerning the etiology of this malignancy. All researchers on the mailing list of Copenhagen Testis Cancer Workshops and...... plausibility of the suggested etiologic hypotheses on a scale of 1 (very implausible) to 10 (very plausible). This report describes the methodology of the survey, the score distributions by individual hypotheses, hypothesis group, and the participants' major research fields, and discuss the hypotheses that...... etiologic hypotheses that include factors related to endocrine disruption, DNA damage, inflammation, and nutrition during pregnancy. The survey results may stimulate a multidisciplinary discussion about new etiologic hypotheses of testicular cancer....

  18. Principle Component Analysis of Birkeland Currents Determined by the Active Magnetosphere and Planetary Electrodynamics Response Experiment

    Milan, S. E.; Carter, J. A.; Korth, H.; Anderson, B. J.

    2015-12-01

    Principle Component Analysis is performed on northern and southern hemisphere Birkeland or field-aligned current (FAC) measurements from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). PCA identifies the patterns in the FACs that respond coherently to different aspects of geomagnetic activity. The region 1 and 2 current system is shown to be the most reproducible feature of the currents, followed by cusp currents associated with magnetic tension forces on newly-reconnected field lines. The cusp currents are strongly modulated by season, indicating that their strength is regulated by the ionospheric conductance at the foot of the field lines. PCA does not identify a pattern that is clearly characteristic of a substorm current wedge. Rather, a superposed epoch analysis of the currents associated with substorms demonstrates that there is not a single mode of response, but a complicated and subtle mixture of different patterns. Other interhemispheric differences are discussed.

  19. Principal component analysis of Birkeland currents determined by the Active Magnetosphere and Planetary Electrodynamics Response Experiment

    Milan, S. E.; Carter, J. A.; Korth, H.; Anderson, B. J.

    2015-12-01

    Principal component analysis is performed on Birkeland or field-aligned current (FAC) measurements from the Active Magnetosphere and Planetary Electrodynamics Response Experiment. Principal component analysis (PCA) identifies the patterns in the FACs that respond coherently to different aspects of geomagnetic activity. The regions 1 and 2 current system is shown to be the most reproducible feature of the currents, followed by cusp currents associated with magnetic tension forces on newly reconnected field lines. The cusp currents are strongly modulated by season, indicating that their strength is regulated by the ionospheric conductance at the foot of the field lines. PCA does not identify a pattern that is clearly characteristic of a substorm current wedge. Rather, a superposed epoch analysis of the currents associated with substorms demonstrates that there is not a single mode of response, but a complicated and subtle mixture of different patterns.

  20. Principal component analysis of Birkeland currents determined by the Active Magnetosphere and Planetary Electrodynamics Response Experiment

    Milan, S E; Korth, H; Anderson, B J

    2016-01-01

    Principal component analysis is performed on Birkeland or field-aligned current (FAC) measurements from the Active Magnetosphere and Planetary Electrodynamics Response Experiment. Principal component analysis (PCA) identifies the patterns in the FACs that respond coherently to different aspects of geomagnetic activity. The regions 1 and 2 current system is shown to be the most reproducible feature of the currents, followed by cusp currents associated with magnetic tension forces on newly reconnected field lines. The cusp currents are strongly modulated by season, indicating that their strength is regulated by the ionospheric conductance at the foot of the field lines. PCA does not identify a pattern that is clearly characteristic of a substorm current wedge. Rather, a superposed epoch analysis of the currents associated with substorms demonstrates that there is not a single mode of response, but a complicated and subtle mixture of different patterns.

  1. Current status of neutron activation analysis using the Dalat Nuclear Research Reactor

    Nguyen Van Suc; Nguyen Mong Sinh [Nuclear Research Institute, Dalat (Viet Nam)

    1999-10-01

    Neutron activation analysis is one of the most sensitive, rapid, accurated methods for determination of trace elements in different materials. A review is made of the current status of the activities and the results in studying and developing NAA (Neutron Activation Analysis) at the Dalat Nuclear Research Institute and applying this method to different sectors of science and technology in Vietnam. (author)

  2. Parent's Interests, Current Involvement and Level of Parental Involvement in School Activities.

    Gbadamosi, Tara; Lin, Huey-Ling

    This study examined what school activities parents were involved in and the relationship between parents' interests and level of participation. Parents completed self-report questionnaires examining activities they were currently involved in and activities they would like to do in their children's classrooms. Out of 208 surveys distributed, 114…

  3. Hypotheses of cancer weakening and origin.

    Chan, John Cheung Yuen

    2015-01-01

    Approximately 2.7 billion years ago, cyanobacteria began producing oxygen by photosynthesis. Any free oxygen they produced was chemically captured by dissolved iron or organic matter. There was no ozone layer to protect living species against the radiation from space. Eukaryotic cells lived in water, under hypoxic environments, and metabolized glucose by fermentation. The Great Oxygenation Event (GOE) describes the point when oxygen sinks became saturated. This massive oxygenation of the Earth occurred approximately half a billion years ago. Species that evolved after the GOE are characterized by aerobic metabolism. Mammals evolved approximately a few hundred million years ago, with the ancient eukaryotic genes deeply embedded in their genome. Many genes have been exchanged by horizontal gene transfer (HGT) throughout the history of cellular evolution. Mammals have been invaded by viruses, and while viral genetic relics are embedded in mammalian junk genes, not all junk genes are genetic relics of viruses. These viral relics have been inactivated through evolution and have little impact on mammalian life. However, there is evidence to suggest that these viral genetic relics are linked to cancer. This hypothesis states that cancer develops when cell reproduction becomes defective because of the active involvement of viral genes, in a process similar to genetic engineering. Cancer cells are amalgamations of genetically modified organisms (GMOs). There are two main groups in cancer development. One group of cells arises by genetic engineering of a viral genetic relic, such as endogenous retroviruses (ERVs), which evolved after oxygenation of the atmosphere. This group is referred to here as genetically modified organisms from viral genes (GMOV). GMOVs may be inhibited by anticancer drugs. The second group arises by engineering of the genes of ancient eukaryotes, which existed prior to the oxygenation of the Earth. This second group is referred to as genetically

  4. Evolutionary origins of human handedness: evaluating contrasting hypotheses.

    Cochet, Hélène; Byrne, Richard W

    2013-07-01

    Variation in methods and measures, resulting in past dispute over the existence of population handedness in nonhuman great apes, has impeded progress into the origins of human right-handedness and how it relates to the human hallmark of language. Pooling evidence from behavioral studies, neuroimaging and neuroanatomy, we evaluate data on manual and cerebral laterality in humans and other apes engaged in a range of manipulative tasks and in gestural communication. A simplistic human/animal partition is no longer tenable, and we review four (nonexclusive) possible drivers for the origin of population-level right-handedness: skilled manipulative activity, as in tool use; communicative gestures; organizational complexity of action, in particular hierarchical structure; and the role of intentionality in goal-directed action. Fully testing these hypotheses will require developmental and evolutionary evidence as well as modern neuroimaging data. PMID:23546932

  5. Evaluating alternative stem cell hypotheses for adultcorneal epithelial maintenance

    John D West; Natalie J Dorà; Natalie J Dorà,

    2015-01-01

    In this review we evaluate evidence for three differenthypotheses that explain how the corneal epitheliumis maintained. The limbal epithelial stem cell (LESC)hypothesis is most widely accepted. This proposes thatstem cells in the basal layer of the limbal epithelium,at the periphery of the cornea, maintain themselvesand also produce transient (or transit) amplifying cells(TACs). TACs then move centripetally to the centre ofthe cornea in the basal layer of the corneal epitheliumand also replenish cells in the overlying suprabasallayers. The LESCs maintain the corneal epitheliumduring normal homeostasis and become more active torepair significant wounds. Second, the corneal epithelialstem cell (CESC) hypothesis postulates that, duringnormal homeostasis, stem cells distributed throughoutthe basal corneal epithelium, maintain the tissue.According to this hypothesis, LESCs are present in thelimbus but are only active during wound healing. We alsoconsider a third possibility, that the corneal epithelium ismaintained during normal homeostasis by proliferationof basal corneal epithelial cells without any input fromstem cells. After reviewing the published evidence,we conclude that the LESC and CESC hypotheses areconsistent with more of the evidence than the thirdhypothesis, so we do not consider this further. The LESCand CESC hypotheses each have difficulty accountingfor one main type of evidence so we evaluate the twokey lines of evidence that discriminate between them.Finally, we discuss how lineage-tracing experimentshave begun to resolve the debate in favour of theLESC hypothesis. Nevertheless, it also seems likely thatsome basal corneal epithelial cells can act as long-termprogenitors if limbal stem cell function is compromised.Thus, this aspect of the CESC hypothesis may have alasting impact on our understanding of corneal epithelialmaintenance, even if it is eventually shown that stemcells are restricted to the limbus as proposed by the

  6. Sticky Genomes: Using NGS Evidence to Test Hybrid Speciation Hypotheses

    Morgan-Richards, Mary; Hills, Simon F. K.; Biggs, Patrick J.; Trewick, Steven A.

    2016-01-01

    Hypotheses of hybrid origin are common. Here we use next generation sequencing to test a hybrid hypothesis for a non-model insect with a large genome. We compared a putative hybrid triploid stick insect species (Acanthoxyla geisovii) with its putative paternal diploid taxon (Clitarchus hookeri), a relationship that provides clear predictions for the relative genetic diversity within each genome. The parental taxon is expected to have comparatively low allelic diversity that is nested within the diversity of the hybrid daughter genome. The scale of genome sequencing required was conveniently achieved by extracting mRNA and sequencing cDNA to examine expressed allelic diversity. This allowed us to test hybrid-progenitor relationships among non-model organisms with large genomes and different ploidy levels. Examination of thousands of independent loci avoids potential problems produced by the silencing of parts of one or other of the parental genomes, a phenomenon sometimes associated with the process of stabilisation of a hybrid genome. Transcript assembles were assessed for evidence of paralogs and/or alternative splice variants before proceeding. Comparison of transcript assemblies was not an appropriate measure of genetic variability, but by mapping reads back to clusters derived from each species we determined levels of allelic diversity. We found greater cDNA sequence diversity among alleles in the putative hybrid species (Acanthoxyla geisovii) than the non-hybrid. The allelic diversity within the putative paternal species (Clitachus hookeri) nested within the hybrid-daughter genome, supports the current view of a hybrid-progenitor relationship for these stick insect species. Next generation sequencing technology provides opportunities for testing evolutionary hypotheses with non-model organisms, including, as here, genomes that are large due to polyploidy. PMID:27187689

  7. Hypotheses for Near-Surface Exchange of Methane on Mars

    Hu, Renyu; Bloom, A. Anthony; Gao, Peter; Miller, Charles E.; Yung, Yuk L.

    2016-07-01

    The Curiosity rover recently detected a background of 0.7 ppb and spikes of 7 ppb of methane on Mars. This in situ measurement reorients our understanding of the Martian environment and its potential for life, as the current theories do not entail any geological source or sink of methane that varies sub-annually. In particular, the 10-fold elevation during the southern winter indicates episodic sources of methane that are yet to be discovered. Here we suggest a near-surface reservoir could explain this variability. Using the temperature and humidity measurements from the rover, we find that perchlorate salts in the regolith deliquesce to form liquid solutions, and deliquescence progresses to deeper subsurface in the season of the methane spikes. We therefore formulate the following three testable hypotheses. The first scenario is that the regolith in Gale Crater adsorbs methane when dry and releases this methane to the atmosphere upon deliquescence. The adsorption energy needs to be 36 kJ/mol to explain the magnitude of the methane spikes, higher than existing laboratory measurements. The second scenario is that microorganisms convert organic matter in the soil to methane when they are in liquid solutions. This scenario does not require regolith adsorption, but entails extant life on Mars. The third scenario is that deep subsurface aquifers produce the bursts of methane. Continued in situ measurements of methane and water, as well as laboratory studies of adsorption and deliquescence, will test these hypotheses and inform the existence of the near-surface reservoir and its exchange with the atmosphere.

  8. Active power compensator of the current harmonics based on the instantaneous power theory

    Marian GAICEANU

    2005-12-01

    Full Text Available The quality of the electrical current becomes a major concern. The proliferation of the power electronic converters, which are used extensively to control electrical apparatus in industrial and commercial applications (dc and ac variable speed motor drives, induction furnaces, power line conditioners, and industrial power supplies, is at the origin of the AC current distribution network pollution and the reactive power demand. These power electronic converters typically draw non-sinusoidal currents from the utility, causing interference with adjacent sensitive loads and limit the utilization of the available electrical supply. The quality of the electrical current thus becomes a significant concern for the distributors of energy and their customers. Recent progress as regards technology of the power electronics brings a capacity of compensation and correction of the harmonic distortion generated by the nonlinear loads. In this paper a parallel active filter prototype capable of reducing the total harmonic distortion in the supply for most current source or adjustable speed drive type loads is presented. A 33 kVA active power filter was developed for harmonic and reactive power compensation based on the instantaneous power theory. The active filter configuration requires the measurement of both the load and filter currents. Experimental results from a prototype active power filter confirm the suitability of the proposed approach. The actual 33kVA prototype converter has been built and tested in the SIEI S.p.A. (Italy laboratory under the Marie Curie Post Doctoral research. The active power compensator is controlled by a high performance DSP platform, resulting in the following active filter features: source current reduction up to the 25th harmonic, 10% THD achievable for current source type loads, efficiency above 97%, does not cause resonance with other loads, operation in the presence of unbalanced loads, reactive power and harmonics

  9. HARMONIC CURRENT COMPENSATION IN SELF EXCITED INDUCTION GENERATOR USING ACTIVE FILTER

    K, Premalatha

    2015-01-01

    The Self-Excited Induction Generator (SEIG) is more suitable for wind energy conversion systems in remotely located areas. The system consists of squirrel cage induction machine coupled with wind turbine through a gear box, Voltage Source Converter (VSC) as active power filter, fixed capacitor bank and diode rectifier with RL load.  SEIG feeding nonlinear load causes current harmonics in the generator current. This paper focuses on minimizing the current harmonics to some extent using shunt A...

  10. Green Compact Temperature Evolution during Current-Activated Tip-Based Sintering (CATS) of Nickel

    Khaled Morsi; Samuel K. Kassegne; Ahmed El Desouky; Kee S. Moon

    2013-01-01

    Current-activated tip-based sintering (CATS) is a novel process where spark plasma sintering conditions are applied through an electrically conducting tip on a locally controlled area on a green powder compact/bed. The localization of electric current in CATS allows for unique temporal and spatial current and temperature distributions within the tip and powder compact. In this paper, special experimental setups were used to monitor the temperature profiles in the tip and at multiple locations...

  11. Thermally-Activated Magnetic Reversal Induced by a Spin-Polarized Current

    Myers, E. B.; Albert, F. J.; Saneky, J. C.; Bonet, E.; Buhrman, R. A.; Ralph, D. C.

    2002-01-01

    We have measured the statistical properties of magnetic reversal in nanomagnets driven by a spin-polarized current. Like reversal induced by a magnetic field, spin-transfer-driven reversal near room temperature exhibits the properties of thermally-activated escape over an effective barrier. However, the spin-transfer effect produces qualitatively different behaviors than an applied magnetic field. We discuss an effective current vs. field phase diagram. If the current and field are tuned so t...

  12. North-south asymmetry of solar dynamo in the current activity cycle

    Kitchatinov, L. L.; Khlystova, A. I.

    2014-01-01

    An explanation is suggested for the north-south asymmetry of the polar magnetic field reversal in the current cycle of solar activity. The contribution of the Babcock-Leighton mechanism to the poloidal field generation is estimated using sunspot data for the current activity cycle. Estimations are performed separately for the northern and southern hemispheres. The contribution of the northern hemisphere exceeded considerably that of the southern hemisphere during the initial stage of the cycl...

  13. A case control study of premorbid and currently reported physical activity levels in chronic fatigue syndrome

    Buchwald Dedra

    2006-11-01

    Full Text Available Abstract Background Patients with chronic fatigue syndrome typically report high levels of physical activity before becoming ill. Few studies have examined premorbid and current activity levels in chronically fatigued patients. Methods In a case-control study, 33 patients with chronic, unexplained, disabling fatigue attending a university-based clinic specializing in fatigue were compared to 33 healthy, age- and sex-matched controls. Patients rated their activity levels before their illness and currently, using scales designed for this purpose. Controls reported their level of activity of 2 years previously and currently. Chi-square analyses, Student's t tests, and Wilcoxon signed rank tests were used in pair matched analyses. Results Compared to healthy controls, patients with chronic, unexplained fatigue rated themselves as more active before their illness (p ≤ 0.001 and less active currently (p ≤ 0.001. The patients also reported they currently stood or walked less than the controls (median [inter-quartile range] = 4 2345 versus 9 [7.5–12] hours, p ≤ 0.001, and spent more time reclining (median [inter-quartile range] = 12 10111213141516 versus 8 [8–9.5] hours, p ≤ 0.001. These differences remained significant for the subset of patients who met strict criteria for chronic fatigue syndrome or fibromyalgia. Conclusion Patients with chronic, unexplained, disabling fatigue reported being more active before becoming ill than healthy controls. This finding could be explained by greater premorbid activity levels that could predispose to illness, or by an overestimation of previous activity. Either possibility could influence patients' perceptions of their current activity levels and their judgments of recovery. Perceived activity should be addressed as part of management of the illness.

  14. Duration differences of corticostriatal responses in striatal projection neurons depend on calcium activated potassium currents

    Mario Alberto Arias-García

    2013-10-01

    Full Text Available The firing of striatal projection neurons (SPNs exhibits afterhyperpolarizing potentials (AHPs that determine discharge frequency. They are in part generated by Ca2+-activated K+-currents involving BK and SK components. It has previously been shown that suprathreshold corticostriatal responses are more prolonged and evoke more action potentials in direct pathway SPNs (dSPNs than in indirect pathway SPNs (iSPNs. In contrast, iSPNs generate dendritic autoregenerative responses. Using whole cell recordings in brain slices, we asked whether the participation of Ca2+-activated K+-currents plays a role in these responses. Secondly, we asked if these currents may explain some differences in synaptic integration between dSPNs and iSPNs. Neurons obtained from BAC D1 and D2 GFP mice were recorded. We used charybdotoxin and apamin to block BK and SK channels, respectively. Both antagonists increased the depolarization and delayed the repolarization of suprathreshold corticostriatal responses in both neuron classes. We also used NS 1619 and NS 309 (CyPPA, to enhance BK and SK channels, respectively. Current enhancers hyperpolarized and accelerated the repolarization of corticostriatal responses in both neuron classes. These drugs made evident that the contribution of Ca2+-activated K+-currents was different in dSPNs as compared to iSPNs: in dSPNs their activation was slower as though calcium took a diffusion delay to activate them. In contrast, their activation was fast and then sustained in iSPNs as though calcium flux activates them at the moment of entry. The blockade of Ca2+-activated K+-currents made iSPNs to look as dSPNs. Conversely, their enhancement made dSPNs to look as iSPNs. It is concluded that Ca2+-activated K+-currents are a main intrinsic determinant causing the differences in synaptic integration between corticostriatal polysynaptic responses between dSPNs and iSPNs.

  15. Early and current physical activity: relationship with intima-media thickness and metabolic variables in adulthood

    Manoel C. S. Lima

    2014-10-01

    Full Text Available Background: It is unclear whether early physical activity has a greater influence on intima-media thickness and metabolic variables than current physical activity. Objective: To analyze the relationship between current and early physical activity, metabolic variables, and intima-media thickness measures in adults. Method: The sample was composed of 55 healthy subjects of both sexes (33 men and 22 women. Total body fat and trunk fat were estimated by dual-energy X-ray absorptiometry. Carotid and femoral intima-media thickness were measured using a Doppler ultrasound device. A 12-hour fasting blood sample collection was taken (fasting glucose and lipid profile. Early physical activity was assessed through face-to-face interview, and the current physical activity was assessed by pedometer (Digi-Walker Yamax, SW200, which was used for a period of seven days. Results: Current physical activity was negatively related to total cholesterol (rho=-0.31, while early physical activity was negatively related to triglycerides (rho=-0.42, total cholesterol (rho=-0.28, very low density lipoprotein (rho=-0.44, and carotid intima-media thickness (rho=-0.50. In the multivariate model, subjects engaged in sports activities during early life had lower values of very low density lipoprotein (b=-8.74 [b=-16.1; -1.47] and carotid intima-media thickness (b=-0.17 [95%CI: -0.28; -0.05]. Conclusion: Early 95%CI physical activity has a significant influence on carotid intima-media thickness, regardless of the current physical activity.

  16. Current studies of biological materials using instrumental and radiochemical neutron activation analysis

    Instrumental neutron activation analysis still remains the preferred option when analysing the trace element distribution in a wide rage of materials by neutron activation analysis. However, when lower limits of detection are required or major interferences reduce the effectiveness of this technique, radiochemical neutron activation analysis is applied. This paper examines the current use of both methods and the development of rapid radiochemical techniques for analysis of the biological materials, hair, cow's milk, human's milk, milk powder, blood and blood serum

  17. Hypotheses for near-surface exchange of methane on Mars

    Hu, Renyu; Gao, Peter; Miller, Charles E; Yung, Yuk L

    2016-01-01

    The Curiosity rover recently detected a background of 0.7 ppb and spikes of 7 ppb of methane on Mars. This in situ measurement reorients our understanding of the Martian environment and its potential for life, as the current theories do not entail any geological source or sink of methane that varies sub-annually. In particular, the 10-fold elevation during the southern winter indicates episodic sources of methane that are yet to be discovered. Here we suggest a near-surface reservoir could explain this variability. Using the temperature and humidity measurements from the rover, we find that perchlorate salts in the regolith deliquesce to form liquid solutions, and deliquescence progresses to deeper subsurface in the season of the methane spikes. We therefore formulate the following three testable hypotheses. The first scenario is that the regolith in Gale Crater adsorbs methane when dry and releases this methane to the atmosphere upon deliquescence. The adsorption energy needs to be 36 kJ/mol to explain the m...

  18. EVOLUTION OF CURRENTS OF OPPOSITE SIGNS IN THE FLARE-PRODUCTIVE SOLAR ACTIVE REGION NOAA 10930

    Analysis of a time series of high spatial resolution vector magnetograms of the active region NOAA 10930 available from the Solar Optical Telescope SpectroPolarimeter on board Hinode revealed that there is a mixture of upward and downward currents in the two footpoints of an emerging flux rope. The flux emergence rate is almost the same in both the polarities. We observe that along with an increase in magnetic flux, the net current in each polarity increases initially for about three days after which it decreases. This net current is characterized by having exactly opposite signs in each polarity while its magnitude remains almost the same most of the time. The decrease of the net current in both the polarities is due to the increase of current having a sign opposite to that of the net current. The dominant current, with the same sign as the net current, is seen to increase first and then decreases during the major X-class flares. Evolution of non-dominant current appears to be a necessary condition for flare initiation. The above observations can be plausibly explained in terms of the superposition of two different force-free states resulting in a non-zero Lorentz force in the corona. This Lorentz force then pushes the coronal plasma and might facilitate the magnetic reconnection required for flares. Also, the evolution of the net current is found to follow the evolution of magnetic shear at the polarity inversion line.

  19. Adaptive Current Control with PI-Fuzzy Compound Controller for Shunt Active Power Filter

    Juntao Fei

    2013-01-01

    Full Text Available An adaptive control technology and PI-fuzzy compound control technology are proposed to control an active power filter (APF. AC side current compensation and DC capacitor voltage tracking control strategy are discussed and analyzed. Model reference adaptive controller for the AC side current compensation is derived and established based on Lyapunov stability theory; proportional and integral (PI fuzzy compound controller is designed for the DC side capacitor voltage control. The adaptive current controller based on PI-fuzzy compound system is compared with the conventional PI controller for active power filter. Simulation results demonstrate the feasibility and satisfactory performance of the proposed control strategies. It is shown that the proposed control method has an excellent dynamic performance such as small current tracking error, reduced total harmonic distortion (THD, and strong robustness in the presence of parameters variation and nonlinear load.

  20. In silico generation of alternative hypotheses using causal mapping (CMAP.

    Gabriel E Weinreb

    Full Text Available Previously, we introduced causal mapping (CMAP as an easy to use systems biology tool for studying the behavior of biological processes that occur at the cellular and molecular level. CMAP is a coarse-grained graphical modeling approach in which the system of interest is modeled as an interaction map between functional elements of the system, in a manner similar to portrayals of signaling pathways commonly used by molecular cell biologists. CMAP describes details of the interactions while maintaining the simplicity of other qualitative methods (e.g., Boolean networks.In this paper, we use the CMAP methodology as a tool for generating hypotheses about the mechanisms that regulate molecular and cellular systems. Furthermore, our approach allows competing hypotheses to be ranked according to a fitness index and suggests experimental tests to distinguish competing high fitness hypotheses. To motivate the CMAP as a hypotheses generating tool and demonstrate the methodology, we first apply this protocol to a simple test-case of a three-element signaling module. Our methods are next applied to the more complex phenomenon of cortical oscillations observed in spreading cells. This analysis produces two high fitness hypotheses for the mechanism that underlies this dynamic behavior and suggests experiments to distinguish the hypotheses. The method can be widely applied to other cellular systems to generate and compare alternative hypotheses based on experimentally observed data and using computer simulations.

  1. Cancellation analysis of current density in solar active region NOAA10019

    De Vita Gaetano

    2015-01-01

    Full Text Available Solar flares are often associated with changes in the fine magnetic structure of the emitting active region. Such topological modification results in variations of both the scaling properties of the fields’ fluctuations, and the fractal dimension of the associated gradients. The use of cancellation analysis of the current density has been attempted for the identification and quantitative estimation of such changes. The characteristics of the magnetic vector as measured by THEMIS telescope for the active region NOAA10019 have been studied in this paper, suggesting the presence of disrupted current filaments. The variation of the fractal dimension of the current structures, and in particular their smoothing, is discussed in relationship with occurrence of one flare in the active region.

  2. A Palladium-Binding Deltarhodopsin for Light-Activated Conversion of Protonic to Electronic Currents.

    Soto-Rodríguez, Jessica; Hemmatian, Zahra; Josberger, Erik E; Rolandi, Marco; Baneyx, François

    2016-08-01

    Fusion of a palladium-binding peptide to an archaeal rhodopsin promotes intimate integration of the lipid-embedded membrane protein with a palladium hydride protonic contact. Devices fabricated with the palladium-binding deltarhodopsin enable light-activated conversion of protonic currents to electronic currents with on/off responses complete in seconds and a nearly tenfold increase in electrical signal relative to those made with the wild-type protein. PMID:27185384

  3. Current activities and lessons learned in the construction of nuclear power plants in Finland

    The full text of publication follows. Finland's Radiation and Nuclear Safety Authority (STUK) is responsible for regulation and inspection of nuclear power construction and operation. The Finnish private utility Teollisuuden Voima Oy (TVO) was granted a construction license for the Olkiluoto 3 pressurised water reactor (type EPR, European pressurised water reactor) on 2005 and operation is currently scheduled to start in 2013. This paper will focus on the current construction activities and lessons learned during the construction of OL3 in Finland. (author)

  4. Vortex-activation energy and critical-currents of YBaCuO thin films

    Douwes, H.; Kes, P. H.

    1994-02-01

    We have performed magnetization experiments using torque-magnetometry, on YBaCuO thin films with and without screw dislocations. Assuming a current dependent activation barrier for flux-creep U( j) = Ucln( jc/ j), the pin potential Uc and the critical-current density jc were determined at different temperatures and fields. Screw dislocations are seen to give rise to a sharp increase of Uc and a saturation of jc at small fields.

  5. Vortex-activation energy and critical-currents of YBaCuO thin films

    We have performed magnetization experiments using torque-magnetometry, on YBaCuO thin films with and without screw dislocations. Assuming a current dependent activation barrier for flux-creep U(j) = Ucln(jc/j), the pin potential Uc and the critical-current density jc were determined at different temperatures and fields. Screw dislocations are seen to give rise to a sharp increase of Uc and a saturation of jc at small fields. (orig.)

  6. Carrier phase shifted SPWM based on current sourced multi-modular converter for active power filter

    王立乔; 李建林; 张仲超

    2004-01-01

    A novel current-source active power filter(APF)based on multi-modular converter with carrier phase-shifted SPWM(CPS-SPWM)technique is proposed.With this technique,the effect of equivalent high switching frequency converter is obtained with low switching frequency converter.It is very promising in current-source APF that adopt superconducting magnetic energy storage component.

  7. Stereo-Based Tracking-by-Multiple Hypotheses Framework for Multiple Vehicle Detection and Tracking

    Young-Chul Lim

    2013-07-01

    Full Text Available In this paper, we present a tracking‐by‐multiple hypotheses framework to detect and track multiple vehicles accurately and precisely. The tracking‐by‐ multiple hypotheses framework consists of obstacle detection, vehicle recognition, visual tracking, global position tracking, data association and particle filtering. The multiple hypotheses are from obstacle detection, vehicle recognition and visual tracking. The obstacle detection detects all the obstacles on the road. The vehicle recognition classifies the detected obstacles as vehicles or non-vehicles. 3D feature‐based visual tracking estimates the current target state using the previous target state. The multiple hypotheses should be linked to corresponding tracks to update the target state. The hierarchical data association method assigns multiple tracks to the correct hypotheses with multiple similarity functions. In the particle filter framework, the target state is updated using the Gaussian motion model and the observation model with associated multiple hypotheses. The experimental results demonstrate that the proposed method enhances the accuracy and precision of the region of interest.

  8. Characterization of the hyperpolarization-activated chloride current in dissociated rat sympathetic neurons.

    Clark, S; Jordt, S E; Jentsch, T J; Mathie, A

    1998-02-01

    1. Dissociated rat superior cervical ganglion (SCG) neurons have been shown to possess a hyperpolarization-activated inwardly rectifying chloride current. The current was not altered by changes in external potassium concentration, replacing external cations with NMDG (N-methyl-D-glucamine) or by addition of 10 mM caesium or barium ions. 2. The reversal potential of the current was altered by changing external anions. The anion selectivity of the current was Cl- > Br- > I- > cyclamate. All substituted permeant anions also blocked the current. 3. The current was blocked by DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid), 9AC (anthracene-9-carboxylic acid) and NPPB (5-nitro-2-(3-phenylpropylamino)benzoic acid) but was unaffected by SITS (4-acetamido-4'-isothiocyanatostilbene- 2,2'-disulphonic acid) and niflumic acid. The effective blockers were voltage dependent; DIDS and NPPB were more effective at depolarized potentials while 9AC was more effective at hyperpolarized potentials. 4. The current was enhanced by extracellular acidification and reduced by extracellular alkalinization. Reducing external osmolarity was without effect in conventional whole-cell recording but enhanced current amplitude in those perforated-patch recordings where little current was evident in control external solution. 5. The current in SCG neurons was blocked by external cadmium and zinc. ClC-2 chloride currents expressed in Xenopus oocytes were also sensitive to block by these divalent ions and by DIDS but the sensitivity of ClC-2 to block by cadmium ions was lower than that of the current in SCG neurons. 6. Reverse transcriptase-polymerase chain reaction (RT-PCR) experiments showed the presence of mRNA for ClC-2 in SCG neurons but not in rat cerebellar granule cells which do not possess a hyperpolarization-activated Cl- current. 7. The data suggest that ClC-2 may be functionally expressed in rat SCG neurons. This current may play a role in regulating the internal chloride

  9. Ways of experiencing participation and factors affecting the current activity level after non-reconstructed ACL injury

    Österberg, Annika; Kvist, Joanna; Abrandt Dahlgren, Madeleine

    2011-01-01

    Current assessment methods after an ACL injury do not consider how the individuals themselves experience their participation in activities or what factors they think have affected their current activity level.

  10. Current-induced strength degradation of activated carbon spheres in carbon supercapacitors

    Sun, Yuan; Chen, Rong; Lipka, Stephen M.; Yang, Fuqian

    2016-05-01

    Activated carbon microspheres (ACSs), which are prepared using hydrothermal synthesis and ammonia activation, are used as the active materials in the anode and cathode of electric double layer capacitors (EDLCs). The ACS-based EDLCs of symmetrical electrodes exhibit good stability and a high degree of reversibility over 2000 charge-discharge cycles for electric current up to 10 A g‑1. The ACSs maintain a nongraphitized carbon structure after over 2000 charge-discharge cycles. Nanoindentation experiments are performed on the ACSs, which are electrochemically cycled in a voltage window of 0–1 V at three electric currents of 0.5, 5, and 10 A g‑1. For the same indentation load, both the contact modulus and indentation hardness of the ACSs decrease with the increase of the electric current used in the electrical charging and discharging. These results suggest that there exists strength degradation introduced by the electric current. A larger electric current will cause more strength degradation than a smaller electric current.

  11. Compensation of Disturbed Load Currents Using Active Power Filter and Generalized Non-active Power Theory

    Lettl, J.; Šimek, Petr; Valouch, Viktor

    Prague: Electromagnetics Academy, 2015, s. 2500-2505. ISSN 1559-9450. [Progress In Electromagnetics Research Symposium Proceedings. Prague (CZ), 06.07.2015-09.07.2015] Institutional support: RVO:61388998 Keywords : disturbed load * GNP (Generalized Non-active Power) * parallel compensation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering www.piers.org

  12. High Performance Current Controller for Selective Harmonic Compensation in Active Power Filters

    Lascu, Cristian; Asiminoaei, Lucian; Boldea, I.;

    2007-01-01

    A new current control scheme for selective harmonic compensation is proposed for shunt active power filters. The method employs an array of resonant current controllers, one for the fundamental, and one for each harmonic, implemented in fundamental reference frame in order to reduce the overall...... computational effort. The proposed controller design is based on the pole-zero cancellation technique, taking into account the load transfer function at each harmonic frequency. Two design methods are provided, which give controller transfer functions with superior frequency response. The complete current...... is supported by experimental results on a 7.6-kVA laboratory filter, indicating a reduction in current THD factor from 34% to 2%, while the highest harmonic compensated is the 37th harmonic current....

  13. Effect of New O-Superfamily Conotoxin on Voltage-Activated Currents of Hippocampal Neurons

    李湛; 何湘平; 戴秋云; 黄培堂; 谢佐平

    2004-01-01

    The effects of a new O-superfamily conotoxin, SO3, on sodium current (/Na), transient A-type potassium currents (/A), and delayed rectified potassium currents (/K), were examined in cultured rat hippocampal neurons using the whole-cell patch clamp technique. Addition of SO3 caused a concentration-dependent,rapidly developing, and reversible inhibition of voltage-activated currents. The IC50 values for the blockage of /Na, /A, and /K were calculated as 0.49, 33.9, and 7.6 μmol/L, respectively. The determined Hill coefficients were 1.7, 0.6, and 1.2, respectively. These results indicate that SO3 can selectively inhibit neuronal sodium and potassium currents.

  14. Current and Future Research in Active Control of Lightweight, Flexible Structures Using the X-56 Aircraft

    Ryan, John J.; Bosworth, John T.; Burken, John J.; Suh, Peter M.

    2014-01-01

    The X-56 Multi-Utility Technology Testbed aircraft system is a versatile experimental research flight platform. The system was primarily designed to investigate active control of lightweight flexible structures, but is reconfigurable and capable of hosting a wide breadth of research. Current research includes flight experimentation of a Lockheed Martin designed active control flutter suppression system. Future research plans continue experimentation with alternative control systems, explore the use of novel sensor systems, and experiments with the use of novel control effectors. This paper describes the aircraft system, current research efforts designed around the system, and future planned research efforts that will be hosted on the aircraft system.

  15. North-south asymmetry of solar dynamo in the current activity cycle

    Kitchatinov, L L

    2014-01-01

    An explanation is suggested for the north-south asymmetry of the polar magnetic field reversal in the current cycle of solar activity. The contribution of the Babcock-Leighton mechanism to the poloidal field generation is estimated using sunspot data for the current activity cycle. Estimations are performed separately for the northern and southern hemispheres. The contribution of the northern hemisphere exceeded considerably that of the southern hemisphere during the initial stage of the cycle. This is the probable reason for the earlier reversal of the northern polar field. The estimated contributions of the Babcock-Leighton mechanism are considerably smaller than similar estimations for the previous activity cycles. A relatively weak (<1G) large-scale polar field can be expected for the next activity minimum.

  16. Site characterization and the method of multiple working hypotheses

    Geologic investigations are necessary to determine whether a site is suitable for repository development and, if suitable, whether the site complies with regulatory requirements. Geologic processes and events often cannot be characterized without some degree of residual uncertainty. The method of multiple working hypotheses (MWH) is an approach in which alternative explanations for natural processes and/or events are identified, tested, and evaluated. This paper reports that in practice, several hypotheses may remain viable after all reasonable studies have been completed. Within the context of waste management and civil construction projects, all viable hypotheses that correspond with potential natural hazards must be analyzed in terms of adverse consequences to public health and safety, including radiological safety. For the repository licensing process, viable hypotheses remaining after the evaluation of data and quantification of uncertainty must be analyzed with regard to their consequences related to waste isolation. This approach can be used to determine whether additional studies are necessary to complete the license application

  17. Induction of self awareness in dreams through frontal low current stimulation of gamma activity.

    Voss, Ursula; Holzmann, Romain; Hobson, Allan; Paulus, Walter; Koppehele-Gossel, Judith; Klimke, Ansgar; Nitsche, Michael A

    2014-06-01

    Recent findings link fronto-temporal gamma electroencephalographic (EEG) activity to conscious awareness in dreams, but a causal relationship has not yet been established. We found that current stimulation in the lower gamma band during REM sleep influences ongoing brain activity and induces self-reflective awareness in dreams. Other stimulation frequencies were not effective, suggesting that higher order consciousness is indeed related to synchronous oscillations around 25 and 40 Hz. PMID:24816141

  18. The Friedman's and Mishkin's Hypotheses (Re)Considered

    Christian BORDES; Maveyraud, Samuel

    2008-01-01

    This paper o¤ers to investigate both the Friedman's and Mishkin's hypotheses on the consequences of inflation on output growth. To this end, we first base these hypotheses in a unified framework. Second, in an empirical work based on OECD countries, we distinguish between short-medium and long run and between headline and core inflation. We get two main results. First, nominal uncertainty and inflation are positively linked. Second, headline inflation negatively Granger causes out- put gap (U...

  19. Feeding activity of mussels Mytilus edulis related to near-bed currents and phytoplankton biomass

    Dolmer, Per

    The feeding activity of blue mussels Mytilus edulis was investigated in the field and related to near-bottom current velocities and the phytoplankton biomass in the near-bottom water layers for four days. The body content of Chl-a in mussels and their shell gap size were used as indices of...

  20. Research of resisting of the biological active point for constant and alternative current

    S. N. Peregudov

    2008-05-01

    Full Text Available Is conducted research of resistance of biologically active point (BAT on a direct and variable current. Research results are presented. The estimation of intercommunication between resistance of skin and by an electromagnetic radiation in BAT is done. Is shown possibility of the use of experimental information for diagnostics of the state of human to the organism.

  1. ANALYSIS ON CORRELATIONS BETWEEN SUBSURFACE KINETIC HELICITY AND PHOTOSPHERIC CURRENT HELICITY IN ACTIVE REGIONS

    An investigation on correlations between photospheric current helicity and subsurface kinetic helicity is carried out by analyzing vector magnetograms and subsurface velocities for two rapidly developing active regions. The vector magnetograms are from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager (SDO/HMI) observed Stokes parameters, and the subsurface velocity is from time-distance data-analysis pipeline using HMI Dopplergrams. Over a span of several days, the evolution of the weighted current helicity shows a tendency similar to that of the weighted subsurface kinetic helicity, attaining a correlation coefficient above 0.60 for both active regions. Additionally, there seems to be a phase lag between the evolutions of the unweighted current and subsurface kinetic helicities for one of the active regions. The good correlation between these two helicities indicates that there is some intrinsic connection between the interior dynamics and photospheric magnetic twistedness inside active regions, which may help to interpret the well-known hemispheric preponderance of current-helicity distribution.

  2. Physiological consequences of transient outward K(+) current activation during heart failure in the canine left ventricle

    Cordeiro, Jonathan M; Callø, Kirstine; Moise, N Sydney; Kornreich, Bruce; Giannandrea, Dana; Di Diego, José M; Olesen, Søren-Peter; Antzelevitch, Charles

    2012-01-01

    Background: Remodeling of ion channel expression is well established in heart failure (HF). We determined the extent to which I(to) is reduced in tachypacing-induced HF and assessed the ability of an I(to) activator (NS5806) to recover this current. Method and results: Whole-cell patch clamp was ...

  3. Active and reactive power control of a current-source PWM-rectifier using space vectors

    Salo, M.; Tuusa, H. [Tampere University of Technology (Finland). Department of Electrical Engineering, Power Electronics

    1997-12-31

    In this paper the current-source PWM-rectifier with active and reactive power control is presented. The control system is realized using space vector methods. Also, compensation of the reactive power drawn by the line filter is discussed. Some simulation results are shown. (orig.) 8 refs.

  4. Analysis on Correlations between Subsurface Kinetic Helicity and Photospheric Current Helicity in Active Regions

    Gao, Yu; Zhang, Hongqi

    2012-01-01

    An investigation on correlations between photospheric current helicity and subsur- face kinetic helicity is carried out by analyzing vector magnetograms and subsurface velocities for two rapidly developing active regions. The vector magnetograms are from the SDO/HMI (Solar Dynamics Observatory / Helioseismic and Magnetic Im- ager) observed Stokes parameters, and the subsurface velocity is from time-distance data-analysis pipeline using HMI Dopplergrams. Over a span of several days, the evo- lution of the weighted current helicity shows a tendency similar to that of the weighted subsurface kinetic helicity, attaining a correlation coefficient above 0.60 for both ac- tive regions. Additionally, there seems to be a phase lag between the evolutions of the unweighted current and subsurface kinetic helicities for one of the active regions. The good correlation between these two helicities indicate that there is some intrinsic con- nection between the interior dynamics and photospheric magnetic twistedness inside ac...

  5. Green Compact Temperature Evolution during Current-Activated Tip-Based Sintering (CATS of Nickel

    Khaled Morsi

    2013-04-01

    Full Text Available Current-activated tip-based sintering (CATS is a novel process where spark plasma sintering conditions are applied through an electrically conducting tip on a locally controlled area on a green powder compact/bed. The localization of electric current in CATS allows for unique temporal and spatial current and temperature distributions within the tip and powder compact. In this paper, special experimental setups were used to monitor the temperature profiles in the tip and at multiple locations on the surface of nickel powder compacts. A variation in the initial green density was found to have a significant effect on the maximum temperature in the tip as well as the temperature distribution across the powder compact. In general, the lowest green density specimens displayed the best conditions for localized densification. The concept of effective current density is introduced and results are discussed in relation to the densification parameter.

  6. Differential effects of the transient outward K(+) current activator NS5806 in the canine left ventricle

    Calloe, Kirstine; Soltysinska, Ewa; Jespersen, Thomas;

    2009-01-01

    -clamp techniques. NS5806 activation of K(v)4.3 current was also studied in CHO-K1 cells and Xenopus laevis oocytes. In CHO-K1 cells co-transfected with K(v)4.3 and KChIP2, NS5806 (10 microM) caused a 35% increase in current amplitude and a marked slowing of current decay with tau increasing from 7.0+/-0.4 to 10...... in Epi and Mid cells. The KChIP2 gradient was confirmed at the protein level by Western blot. Our results suggest that NS5806 augments I(to) by increasing current density and slowing decay and that both depend on the presence of KChIP2. I(to) and its augmentation by NS5806 are greatest in Epi and Mid...

  7. Voltage Quality Enhancement and Fault Current Limiting with Z-Source based Series Active Filter

    F. Gharedaghi

    2011-11-01

    Full Text Available In this study, series active filter or dynamic voltage restorer application is proposed for reduction of downstream fault current in addition to voltage quality enhancement. Recently, the application of Z-source inverter is proposed in order to optimize DVR operation. This inverter makes DVR to operate appropriately when the energy storage device’s voltage level severely falls. Here, the Z-source inverter based DVR is proposed to compensate voltage disturbance at the PCC and to reduce the fault current in downstream of DVR. By calculating instantaneous current magnitude in synchronous frame, control system recognizes if the fault exists or not, and determines whether DVR should compensate voltage disturbance or try to reduce the fault current. The proposed system is simulated under voltage sag and swell and short circuit conditions. The simulation results show that the system operates correctly under voltage sag and short circuit conditions.

  8. Mitigation of Wind Power Fluctuation by Active Current Control of Variable Speed Wind Turbines

    Zhang, Yunqian; Chen, Zhe; Hu, Weihao; Cheng, Ming

    2013-01-01

    Wind shear and tower shadow are the sources of power fluctuation of grid connected wind turbines during continuous operation. This paper presents a simulation model of a MW-level doubly fed induction generator (DFIG) based variable speed wind turbine with a partial-scale back-to-back power...... converter in Simulink. A simple and effective method of wind power fluctuations mitigation by active current control of DFIG is proposed. It smoothes the generator output active power oscillations by adjusting the active current of the DFIG, such that the power oscillation is stored as the kinetic energy of...... the wind turbine. The simulations are performed on the NREL 1.5MW upwind reference wind turbine model. The simulation results are presented and discussed to demonstrate the validity of the proposed control method....

  9. Thermal activation of current in an inhomogeneous Schottky diode with a Gaussian distribution of barrier height

    This paper investigates the thermal activation behaviour of current in an inhomogeneous Schottky diode with a Gaussian distribution of barrier height by numerical simulation. The analytical Gaussian distribution model predicted that the I-V-T curves may intersect with the possibility of the negative thermal activation of current, but may be contradictory to the thermionic emission mechanism in a Schottky diode. It shows that the cause of the unphysical phenomenon is related to the incorrect calculation of current across very low barriers. It proposes that junction voltage Vj, excluding the voltage drop across series resistance from the external bias, is a crucial parameter for correct calculation of the current across very low barriers. For correctly employing the thermionic emission model, Vj needs to be smaller than the barrier height ø. With proper scheme of series resistance connection where the condition of Vj > ø is guaranteed, I-V-T curves of an inhomogeneous Schottky diode with a Gaussian distribution of barrier height have been simulated, which demonstrate normal thermal activation. Although the calculated results exclude the intersecting possibility of I-V-T curves with an assumption of temperature-independent series resistance, it shows that the intersecting is possible when the series resistance has a positive temperature coefficient. Finally, the comparison of our numerical and analytical results indicates that the analytical Gaussian distribution model is valid and accurate in analysing I-V-T curves only for small barrier height inhomogeneity. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  10. Calcium-activated chloride currents in primary cultures of rabbit distal convoluted tubule.

    Bidet, M; Tauc, M; Rubera, I; de Renzis, G; Poujeol, C; Bohn, M T; Poujeol, P

    1996-10-01

    Chloride (Cl-) conductances were studied in primary cultures of rabbit distal convoluted tubule (very early distal "bright" convoluted tubule, DCTb) by the whole cell patch-clamp technique. We identified a Cl- current activated by 2 microM extracellular ionomycin. The kinetics of the macroscopic current were time dependent for depolarizing potentials with a slow developing component. The steady state current presented outward rectification, and the ion selectivity sequence was I- > Br- > > Cl > glutamate. The current was inhibited by 0.1 mM 5-nitro-2-(3-phenylpropyl-amino)benzoic acid, 1 mM 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, and 1 mM diphenylamine-2-carboxylate. To identify the location of the Cl- conductance, 6-methoxy-N-(3-sulfopropyl)quinolinium fluorescence experiments were carried out in confluent cultures developed on collagen-coated permeable filters. Cl- removal from the apical solution induced a Cl- efflux that was stimulated by 10 microM forskolin. Forskolin had no effect on the basolateral Cl- permeability Cl- substitution in the basolateral solution induced an efflux stimulated by 2 microM ionomycin or 50 microM extracellular ATP Ionomycin had no effect on the apical Cl- fluxes. Thus cultured DCTb cells exhibit Ca(2+)-activated Cl- channels located in the basolateral membrane. This Cl- permeability was active at a resting membrane potential and could participate in the Cl- reabsorption across the DCTb in control conditions. PMID:8898026

  11. Flux Emergence in the Solar Active Region NOAA 11158: The Evolution of Net Current

    Vemareddy, P; Karthikreddy, S

    2015-01-01

    We present a detailed investigation on the evolution of observed net vertical current using a time series of vector magnetograms of the active region (AR) NOAA 11158 obtained from Helioseismic Magnetic Imager. We also discuss the relation of net current to the observed eruptive events. The AR evolved from $\\beta\\gamma$ to $\\beta\\gamma\\delta$ configuration over a period of 6 days. The AR had two sub-regions of activity with opposite chirality: one dominated by sunspot rotation producing a strong CME, the other showing large shear motions producing a strong flare. The net current in each polarity over the CME producing sub-region increased to a maximum and then decreased when the sunspots got separated. The time profile of net current in this sub-region followed the time profile of the rotation rate of the S-polarity sunspot of the same sub-region. The net current in the flaring sub-region showed a sudden increase at the time of the strong flare and remained unchanged till the end of the observation, while the ...

  12. A Metabolic Biofuel Cell: Conversion of Human Leukocyte Metabolic Activity to Electrical Currents

    Cui X Tracy

    2011-05-01

    Full Text Available Abstract An investigation of the electrochemical activity of human white blood cells (WBC for biofuel cell (BFC applications is described. WBCs isolated from whole human blood were suspended in PBS and introduced into the anode compartment of a proton exchange membrane (PEM fuel cell. The cathode compartment contained a 50 mM potassium ferricyanide solution. Average current densities between 0.9 and 1.6 μA cm-2 and open circuit potentials (Voc between 83 and 102 mV were obtained, which were both higher than control values. Cyclic voltammetry was used to investigate the electrochemical activity of the activated WBCs in an attempt to elucidate the mechanism of electron transfer between the cells and electrode. Voltammograms were obtained for the WBCs, including peripheral blood mononuclear cells (PBMCs - a lymphocyte-monocyte mixture isolated on a Ficoll gradient, a B lymphoblastoid cell line (BLCL, and two leukemia cell lines, namely K562 and Jurkat. An oxidation peak at about 363 mV vs. SCE for the PMA (phorbol ester activated primary cells, with a notable absence of a reduction peak was observed. Oxidation peaks were not observed for the BLCL, K562 or Jurkat cell lines. HPLC confirmed the release of serotonin (5-HT from the PMA activated primary cells. It is believed that serotonin, among other biochemical species released by the activated cells, contributes to the observed BFC currents.

  13. Enhanced Stability of Capacitor-Current Feedback Active Damping for LCL-Filtered Grid Converters

    Xin, Zhen; Wang, Xiongfei; Loh, Poh Chiang;

    2015-01-01

    The proportional capacitor-current feedback active damping method has been widely used to suppress the LCL-filter resonance. However, the time delay in the damping control loop may lead to non-minimum phase or even unstable responses when the resonance frequency varies in a wide range. To improve...... the robustness of damping, this paper proposes an improved damping controller with the capacitor current feedback loop, which is based on the second-order generalized integrator, instead of a proportional gain, which can effectively mitigate the detrimental effect of the time delay. Robustness of the...

  14. DOPAMINE RECEPTOR ACTIVATION CAN REDUCE VOLTAGE-GATED Na+ CURRENT BY MODULATING BOTH ENTRY INTO AND RECOVERY FROM INACTIVATION

    Hayashida, Yuki; Ishida, Andrew T.

    2004-01-01

    We tested whether dopamine receptor activation modulates the voltage-gated Na+ current of goldfish retinal ganglion cells, using a fast voltage-clamp amplifier, perforated-patch whole-cell mode, and a physiological extracellular Na+ concentration. As found in other cells, activators of D1-type dopamine receptors and of protein kinase A reduced the amplitude of current activated by depolarizations from resting potential, without altering the current kinetics or activation range. However, D1-ty...

  15. Flux emergence in the solar active region NOAA 11158: the evolution of net current

    We present a detailed investigation of the evolution of observed net vertical current using a time series of vector magnetograms of the active region (AR) NOAA 11158 obtained from the Helioseismic and Magnetic Imager. We also discuss the relation of net current to the observed eruptive events. The AR evolved from the βγ to βγδ configuration over a period of six days. The AR had two sub-regions of activity with opposite chirality: one dominated by sunspot rotation producing a strong CME, and the other showing large shear motions producing a strong flare. The net current in each polarity over the CME producing sub-region increased to a maximum and then decreased when the sunspots were separated. The time profile of net current in this sub-region followed the time profile of the rotation rate of the south-polarity sunspot in the same sub-region. The net current in the flaring sub-region showed a sudden increase at the time of the strong flare and remained unchanged until the end of the observation, while the sunspots maintained their close proximity. The systematic evolution of the observed net current is seen to follow the time evolution of total length of strongly sheared polarity inversion lines in both of the sub-regions. The observed photospheric net current could be explained as an inevitable product of the emergence of a twisted flux rope, from a higher pressure confinement below the photosphere into the lower pressure environment of the photosphere. (paper)

  16. In vitro - in vivo correlations for endocrine activity of a mixture of currently used pesticides

    Two pesticide mixtures were investigated for potential endocrine activity. Mix 3 consisted of bitertanol, propiconazole, and cypermethrin, and Mix 5 included malathion and terbuthylazine in addition to the three pesticides in Mix 3. All five single pesticides and the two mixtures were investigated for their ability to affect steroidogenesis in vitro in H295R cells. The pesticides alone and both mixtures affected steroidogenesis with both mixtures causing increase in progesterone and decrease in testosterone. For Mix 5 an increase in estradiol was seen as well, indicating increased aromatase activity. The two mixtures were also investigated in pregnant rats dosed from gestational day 7 to 21, followed by examination of dams and fetuses. Decreased estradiol and reduced placental testosterone were seen in dams exposed to Mix 5. Also a significant increase in aromatase mRNA-levels in female adrenal glands was found for Mix5. However, either of the two mixtures showed any effects on fetal hormone levels in plasma or testis, or on anogenital distance. Overall, potential aromatase induction was found for Mix 5 both in vitro and in vivo, but not for Mix 3, an effect likely owed to terbuthylazine in Mix 5. However, the hormonal responses in vitro were only partly reflected in vivo, probably due to some toxicokinetic issues, as the pesticide levels in the amniotic fluid also were found to be negatively affected by the number of compounds present in the mixtures. Nonetheless, the H295R assay gives hints on conceivable interference with steroidogenesis, thus generating hypotheses on in vivo effects. - Highlights: • The study examines the endocrine disrupting potential of mixtures of pesticides. • All single pesticides and both mixtures affected steroidogenesis in vitro. • Potential aromatase induction was found for Mix 5 both in vitro and in vivo. • The hormonal responses in vitro were only partly reflected in vivo

  17. A self-sensing active magnetic bearing based on a direct current measurement approach.

    Niemann, Andries C; van Schoor, George; du Rand, Carel P

    2013-01-01

    Active magnetic bearings (AMBs) have become a key technology in various industrial applications. Self-sensing AMBs provide an integrated sensorless solution for position estimation, consolidating the sensing and actuating functions into a single electromagnetic transducer. The approach aims to reduce possible hardware failure points, production costs, and system complexity. Despite these advantages, self-sensing methods must address various technical challenges to maximize the performance thereof. This paper presents the direct current measurement (DCM) approach for self-sensing AMBs, denoting the direct measurement of the current ripple component. In AMB systems, switching power amplifiers (PAs) modulate the rotor position information onto the current waveform. Demodulation self-sensing techniques then use bandpass and lowpass filters to estimate the rotor position from the voltage and current signals. However, the additional phase-shift introduced by these filters results in lower stability margins. The DCM approach utilizes a novel PA switching method that directly measures the current ripple to obtain duty-cycle invariant position estimates. Demodulation filters are largely excluded to minimize additional phase-shift in the position estimates. Basic functionality and performance of the proposed self-sensing approach are demonstrated via a transient simulation model as well as a high current (10 A) experimental system. A digital implementation of amplitude modulation self-sensing serves as a comparative estimator. PMID:24030681

  18. A Self-Sensing Active Magnetic Bearing Based on a Direct Current Measurement Approach

    Carel P. du Rand

    2013-09-01

    Full Text Available Active magnetic bearings (AMBs have become a key technology in various industrial applications. Self-sensing AMBs provide an integrated sensorless solution for position estimation, consolidating the sensing and actuating functions into a single electromagnetic transducer. The approach aims to reduce possible hardware failure points, production costs, and system complexity. Despite these advantages, self-sensing methods must address various technical challenges to maximize the performance thereof. This paper presents the direct current measurement (DCM approach for self-sensing AMBs, denoting the direct measurement of the current ripple component. In AMB systems, switching power amplifiers (PAs modulate the rotor position information onto the current waveform. Demodulation self-sensing techniques then use bandpass and lowpass filters to estimate the rotor position from the voltage and current signals. However, the additional phase-shift introduced by these filters results in lower stability margins. The DCM approach utilizes a novel PA switching method that directly measures the current ripple to obtain duty-cycle invariant position estimates. Demodulation filters are largely excluded to minimize additional phase-shift in the position estimates. Basic functionality and performance of the proposed self-sensing approach are demonstrated via a transient simulation model as well as a high current (10 A experimental system. A digital implementation of amplitude modulation self-sensing serves as a comparative estimator.

  19. A new compensation current real-time computing method for power active filter based on double linear construction algorithm

    LI Zicheng; SUN Yukun

    2006-01-01

    Considering the detection principle that "when load current is periodic current, the integral in a cycle for absolute value of load current subtracting fundamental active current is the least", harmonic current real-time detection methods for power active filter are proposed based on direct computation, simple iterative algorithm and optimal iterative algorithm. According to the direct computation method, the amplitude of the fundamental active current can be accurately calculated when load current is placed in stable state. The simple iterative algorithm and the optimal iterative algorithm provide an idea about judging the state of load current. On the basis of the direct computation method, the simple iterative algorithm, the optimal iterative algorithm and precise definition of the basic concepts such as the true amplitude of the fundamental active current when load current is placed in varying state, etc., the double linear construction idea is proposed in which the amplitude of the fundamental active current at the moment of the sample is accurately calculated by using the first linear construction and the condition which disposes the next sample is created by using the second linear construction. On the basis of the double linear construction idea, a harmonic current real-time detection method for power active filter is proposed based on the double linear construction algorithm. This method has the characteristics of small computing quantity, fine real-time performance, being capable of accurately calculating the amplitude of the fundamental active current and so on.

  20. Myocardial perfusion imaging in Denmark: activity from 1997 to 2001 and current practice

    Petersen, Claus Leth; Kjaer, Andreas

    2003-01-01

    A questionnaire was sent to all departments of nuclear medicine in Denmark (n=20) asking for details of myocardial perfusion imaging (MPI), including the number of patients examined each year from 1997 to 2001 and the current clinical and technical practice. All (100%) departments replied, and the...... survey thus covers all MPI performed in Denmark during the period in question. The number of MPI studies (examined patients) was 2,531 in 1997 (0.47 MPI/1,000/year) and 4,961 (0.93 MPI/1,000/year) in 2001, which is a doubling in activity in 5 years. Nineteen (95%) of the Danish departments performed MPI...... in 2001, and 14 (74%) of these reported that activity had increased over the past 5 years. MPI activity was unevenly distributed between hospitals and regions. In 2001, the university hospitals in the central Copenhagen region (capital) accounted for the highest MPI activity (2.00/1,000/year), while...

  1. Effect of Direct-Current Electric Field on Enzymatic Activity and the Concentration of Laccase.

    Wang, Chunxing; Zhang, Huiling; Ren, Dajun; Li, Qian; Zhang, Shuqin; Feng, Tao

    2015-09-01

    This work investigates the effect of direct-current electric field on the extracellular enzymatic activity, concentration and other experimental parameters of laccase from Trametes versicolor. The results showed that laccase could significantly contribute to the change of pH at the end of graphite electrode. In addition, it increased the electrical conductivity of the water. In the experiment, the optimum pH and catalytic pH range for laccase activity were 3.0 and pH 2.5-4.0. The application of 6 V direct current showed significant effects on the laccase enzyme activity. The activity of laccase was enhanced in the anodic region, but at the same time was strongly inhibited at the cathode. The electric charge characteristics of laccase were changed when exposed to electric field, and some laccases molecules moved to the anode, which produced a slight migration phenomenon. This study is the basis of combination of laccase and electrical technology, at the same time, providing a new direction of enhancing laccase activity. Compared to immobilization, using electric field is simple, no chemical additives, and great potential. PMID:26063937

  2. The current e-marketing activities of SME. Case Fotomina Ltd

    Ben Othman, Jelena

    2010-01-01

    This thesis explores the current e-marketing activities of Fotomina Ltd and suggests possible improvements. The topic of this thesis has an important applied perspective for small and medium sized businesses. The e-marketing activities in the case of Fotomina were planned with an eye on the lack of resources young businesses usually have. While working on the thesis it was noticed that e-marketing literature is centred on large businesses with a lot of resources and a variety of ways to opera...

  3. Central European MetEor NeTwork: Current status and future activities

    Srba, J.; Koukal, J.; Ferus, M.; Lenža, L.; Gorková, S.; Civiš, S.; Simon, J.; Csorgei, T.; Jedlièka, M.; Korec, M.; Kaniansky, S.; Polák, J.; Spurný, M.; Brázdil, T.; Mäsiar, J.; Zima, M.; Delinèák, P.; Popek, M.; Bahýl, V.; Piffl, R.; Èechmánek, M.

    2016-06-01

    The Central European video Meteor Network (CEMeNt) established in 2010 is a platform for cross-border cooperation in the field of video meteor observations between Czech Republic and Slovakia. During five years of operation the CEMeNt network went through an extensive development. In total, 37 video systems were working on 20 permanent stations located in Czech Republic and Slovakia during 2015. In this paper we summarize CEMeNt current status and introduce some future activities.

  4. Analysis on Correlations between Subsurface Kinetic Helicity and Photospheric Current Helicity in Active Regions

    Gao, Yu; Zhao, Junwei; Zhang, Hongqi

    2012-01-01

    An investigation on correlations between photospheric current helicity and subsur- face kinetic helicity is carried out by analyzing vector magnetograms and subsurface velocities for two rapidly developing active regions. The vector magnetograms are from the SDO/HMI (Solar Dynamics Observatory / Helioseismic and Magnetic Im- ager) observed Stokes parameters, and the subsurface velocity is from time-distance data-analysis pipeline using HMI Dopplergrams. Over a span of several days, the evo- l...

  5. Calcium-activated chloride current amplifies the response to urine in mouse vomeronasal sensory neurons

    Yang, Chun; Delay, Rona J.

    2010-01-01

    The vomeronasal organ (VNO) is an odor detection system that mediates many pheromone-sensitive behaviors. Vomeronasal sensory neurons (VSNs), located in the VNO, are the initial site of interaction with odors/pheromones. However, how an individual VSN transduces chemical signals into electrical signals is still unresolved. Here, we show that a Ca2+-activated Cl− current contributes ∼80% of the response to urine in mouse VSNs. Using perforated patch clamp recordings with gramicidin, which leav...

  6. Electric current activated/assisted sintering (ECAS): a review of patents 1906–2008

    Salvatore Grasso, Yoshio Sakka and Giovanni Maizza

    2009-01-01

    The electric current activated/assisted sintering (ECAS) is an ever growing class of versatile techniques for sintering particulate materials. Despite the tremendous advances over the last two decades in ECASed materials and products there is a lack of comprehensive reviews on ECAS apparatuses and methods. This paper fills the gap by tracing the progress of ECAS technology from 1906 to 2008 and surveys 642 ECAS patents published over more than a century. It is found that the ECAS technology w...

  7. The physical education teacher as a physical activity promoter: Current developments

    Cloes, Marc

    2014-01-01

    The current society needs to fight against the growing of sedentary lifestyles among the population all around the world. The school environment is identified as a pillar of the multisectorial approach that should be implemented to avoid that children who born today do not live less longer than their parents. The presentation will focus on four topics: (1) The role of school in physical activity (PA) promotion; (2) The dimensions of PA at school; (3) The action that physical education (PE) te...

  8. Landscape moderation of biodiversity patterns and processes - eight hypotheses

    Tscharntke, T.; Tylianakis, J.M.; Rand, T.A.; Didham, R.K.; Fahrig, L.; Batáry, P.; Bengtsson, J.; Clough, Y.; Crist, T.O.; Dormann, C.F.; Ewers, R.M.; Fründ, J.; Holt, R.D.; Holzschuh, A.; Klein, A.M.; Kleijn, D.; Kremen, C.; Landis, D.A.; Laurance, W.; Lindenmayer, D.; Scherber, C.; Sodhi, N.; Steffan-Dewenter, I.; Thies, C.; Van der Putten, W.H.; Westphal, C.

    2012-01-01

    Understanding how landscape characteristics affect biodiversity patterns and ecological processes at local and landscape scales is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest eight hypotheses, which

  9. Relative effects at work : Bayes factors for order hypotheses

    Braeken, J.; Mulder, J.; Wood, S.

    2015-01-01

    Assessing the relative importance of predictors has been of historical importance in a variety of disciplines including management, medicine, economics, and psychology. When approaching hypotheses on the relative ordering of the magnitude of predicted effects (e.g., the effects of discrimination fro

  10. Bayes Factor Approaches for Testing Interval Null Hypotheses

    Morey, Richard D.; Rouder, Jeffrey N.

    2011-01-01

    Psychological theories are statements of constraint. The role of hypothesis testing in psychology is to test whether specific theoretical constraints hold in data. Bayesian statistics is well suited to the task of finding supporting evidence for constraint, because it allows for comparing evidence for 2 hypotheses against each another. One issue…

  11. Addressing Moderated Mediation Hypotheses: Theory, Methods, and Prescriptions

    Preacher, Kristopher J.; Rucker, Derek D.; Hayes, Andrew F.

    2007-01-01

    This article provides researchers with a guide to properly construe and conduct analyses of conditional indirect effects, commonly known as moderated mediation effects. We disentangle conflicting definitions of moderated mediation and describe approaches for estimating and testing a variety of hypotheses involving conditional indirect effects. We…

  12. Sapwood allocation in tropical trees: a test of hypotheses

    Schippers, P.; Vlam, M.; Zuidema, P.A.; Sterck, F.J.

    2015-01-01

    Carbon allocation to sapwood in tropical canopy trees is a key process determining forest carbon sequestration, and is at the heart of tree growth and dynamic global vegetation models (DGVM). Several allocation hypotheses exist including those applying assumptions on fixed allocation, pipe model, an

  13. Toward Valid Measurement of Stephen Pepper's World Hypotheses.

    Johnson, John A.

    Two measures of the "world hypotheses" of Stephen Pepper were mailed to 100 sociobiologists, 87 behaviorists, 79 personality psychologists, and 45 human developmentalists. The World Hypothesis Scale (WHS) was designed to measure Pepper's four world views: (1) formism; (2) mechanism; (3) organicism; and (4) contextualism. The Organicism-Mechanism…

  14. Testing statistical hypotheses about capability indices Cp amd Cpk

    Michálek, Jiří

    Torino : Enbis, 2007. s. 39-40. [ENBIS-DEINDE 2007. 11.04.2007-13.04.2007, Torino] R&D Projects: GA MŠk(CZ) 1M06047 Institutional research plan: CEZ:AV0Z10750506 Keywords : Capability index * densuty function * testing hypotheses * confidence interval Subject RIV: BB - Applied Statistics, Operational Research

  15. Beta-receptor activation increases sodium current in guinea pig heart

    Hong-wei WANG; Zhi-fang YANG; Yin ZHANG; Jian-min YANG; Yuan-mou LIU; Ci-zhen LI

    2009-01-01

    Aim: To study the influence of β-receptor activation on sodium channel current and the physiological significance of increased sodium current with regard to the increased cardiac output caused by sympathetic excitation.Methods: Multiple experimental approaches, including ECG, action potential recording with conventional microelectrodes, whole-cell current measurements, single-channel recordings, and pumping-force measurements, were applied to guinea pig hearts and isolated ventricular myocytes.Results: Isoprenaline was found to dose-dependently shorten QRS waves, increase the amplitude and the Vmaxof action potentials, aug-ment the fast sodium current, and increase the occurrence frequencies and open time constants of the long-open and burst modes of the sodium channel. Increased levels of membrane-permeable cAMP have similar effects. In the presence of a calcium channel blocker, TTX reversed the increased pumping force produced by isoprenaline.Conclusion: Beta-adrenergic modulation increases the inward sodium current and accelerates the conduction velocity within the ventri-cles by changing the sodium channel modes, which might both be conducive to the synchronous contraction of the heart and enhance its pumping function.

  16. Photospheric electric current and transition region brightness within an active region

    Distributions of vertical electric current density (Jsub(z)) calculated from vector measurements of the photospheric magnetic field are compared with ultraviolet spectroheliograms to investigate whether resistive heating is an important source of enhanced emission in the transition region. The photospheric magnetic fields in Active Region 2372 were measured on 6 and 7 April, 1980 with the MSFC vector magnetograph; ultraviolet wavelength spectroheliograms (Lα and Nv 1239 A) were obtained with the UVSP experiment aboard the Solar Maximum Mission satellite. Spatial registration of the Jsub(z) (5 arc sec resolution) and UV (3 arc sec resolution) maps indicates that the maximum current density is cospatial with a minor but persistent UV enhancement, but there is little detected current associated with other nearby bright areas. We conclude that although resistive heating may be important in the transition region, the currents responsible for the heating are largely unresolved in our measurements and have no simple correlation with the residual current measured on 5 arc sec scales. (orig.)

  17. Use of Computational Modeling to Evaluate Hypotheses About the Molecular and Cellular Mechanisms of Bystander Effects

    Zhao, Yuchao; Conolly, Rory B; Andersen, Melvin E.

    2006-11-21

    This report describes the development of a computational systems biology approach to evaluate the hypotheses of molecular and cellular mechanisms of adaptive response to low dose ionizing radiation. Our concept is that computational models of signaling pathways can be developed and linked to biologically based dose response models to evaluate the underlying molecular mechanisms which lead to adaptive response. For development of quantitatively accurate, predictive models, it will be necessary to describe tissues consisting of multiple cell types where the different types each contribute in their own way to the overall function of the tissue. Such a model will probably need to incorporate not only cell type-specific data but also spatial information on the architecture of the tissue and on intercellular signaling. The scope of the current model was more limited. Data obtained in a number of different biological systems were synthesized to describe a chimeric, “average” population cell. Biochemical signaling pathways involved in sensing of DNA damage and in the activation of cell cycle checkpoint controls and the apoptotic path were also included. As with any computational modeling effort, it was necessary to develop these simplified initial descriptions (models) that can be iteratively refined. This preliminary model is a starting point which, with time, can evolve to a level of refinement where large amounts of detailed biological information are synthesized and a capability for robust predictions of dose- and time-response behaviors is obtained.

  18. Open Augmented Reality Standards: Current Activities in Standards- Development Organizations%Open Augmented Reality Standards: Current Activities in Standards- Development Organizations

    Christine Perey

    2012-01-01

    Augmented reality (AR) has emerged from research laboratories and is now being accepted in other domains as an attractive way of visualizing information. Before AR can be used in the mass market, there are a number of obstacles that need to be overcome. Several of these can be overcome by adopting open standards. A global grassroots community seeking open, interoperable AR content and experiences began to take shape in early 2010. This community is working collaboratively to reduce the barriers to the flow of data from content provider to AR end user. Standards development organizations and industry groups that provide open interfaces for AR meet regularly to provide updates, identify complementary work, and seek harmonization. The community also identifies deployer and implementer needs, communicates requirements, and discusses emerging challenges that could be resolved with standards. In this article, we describe current activities in international standards-development organizations. We summarize the AR standards gap analysis and shed light on special considerations for using standards in mobile AR.

  19. A transient outward potassium current activator recapitulates the electrocardiographic manifestations of Brugada syndrome

    Calloe, Kirstine; Cordeiro, Jonathan M; Di Diego, José M;

    2008-01-01

    AIMS: Transient outward potassium current (I(to)) is thought to be central to the pathogenesis of the Brugada syndrome (BrS). However, an I((to)) activator has not been available with which to validate this hypothesis. Here, we provide a direct test of the hypothesis using a novel I(to) activator...... endocardium, and accentuated the ECG J-wave, leading to the development of phase 2 re-entry and polymorphic ventricular tachycardia (n = 9). Although sodium and calcium channel blockers are capable of inducing BrS only in right ventricular (RV) wedge preparations, the I(to) activator was able to induce the....... Our findings also suggest that a genetic defect leading to a gain of function of I(to) could explain variants of BrS, in which ST-segment elevation or J-waves are evident in both right and left ECG leads....

  20. An overview of currently available methods and future trends for physical activity

    Alexander Kiško

    2013-12-01

    Full Text Available Background: Methodological limitations make comparison of various instruments difficult, although the number of publications on physical activity assessment has extensively increased. Therefore, systematization of techniques and definitions is essential for the improvement of knowledge in the area. Objective: This paper systematically describes and compares up-to-date methods that assess habitual physical activity and discusses main issues regarding the use and interpretation of data collected with these techniques. Methods: A general outline of the measures and techniques described above is presented in review form, along with their respective definition, usual applications, positive aspects and shortcomings. Results and conclusions: The various factors to be considered in the selection of physical activity assessment methods include goals, sample size, budget, cultural and social/environmental factors, physical burden for the subject, and statistical factors, such as accuracy and precision. It is concluded that no single current technique is able to quantify all aspects of physical activity under free-living conditions, requiring the use of complementary methods. In not too distant future, devices will take advantage of consumer technologies, such as mobile phones, GPS devices. It is important to perform other activities, such as detecting and responding to physical activity in a real time, creating new opportunities in measurement, remote compliance monitoring, data-driven discovery and intervention.

  1. Extraction of activation energies from temperature dependence of dark currents of SiPM

    Engelmann, E.; Vinogradov, S.; Popova, E.; Wiest, F.; Iskra, P.; Gebauer, W.; Loebner, S.; Ganka, T.; Dietzinger, C.; Fojt, R.; Hansch, W.

    2016-02-01

    Despite several advantages of Silicon Photomultipliers (SiPM) over Photomultiplier Tubes (PMT) like the increased photon detection efficiency (PDE), the compact design and the insensitivity to magnetic fields, the dark count rate (DCR) of SiPM is still a large drawback. Decreasing of the SiPM dark count rate has become a modern task, which could lead to an enormous enhancement of the application range of this promising photo-detector. The main goal of this work is to gain initial information on the dark generation and identify the dominating contributions to dark currents. The chosen approach to fulfill this task is to extract characteristic activation energies of the contributing mechanisms from temperature dependent investigations of dark currents and DCR. Since conventional methods are not suited for a precise analysis of activation energies, a new method has to be developed. In this paper, first steps towards the development of a reliable method for the analysis of dark currents and dark events are presented.

  2. Gradient Descent Learning for Utility Current Compensation using Active Regenerative PWM Filter

    R. Balamurugan

    2011-01-01

    Full Text Available Problem statement: Harmonic analysis is a primary matter of power quality assessment. Its main intention is to check the utility whether it is delivering the loads without any deviations in voltages and currents. The problem is due to proliferation of Electronic converters and power electronics which gave birth to numerous new applications, offering unmatched comfort to the customers. Approach: Harmonics should be maintained within the limits said in standards like IEEE 519 and others such as IEEE 1159 for safeguarding the utility. This was provided by many mitigation technologies like passive, shunt and series filtering, active conditioners, but they were lack of some demerits like huge cost, many controllers and circuit components. So for controlling the harmonic loads the converter with four quadrant characteristics was implemented and this converter act as shunt active filter as well as rectifier simultaneously without any additional circuitry. For having better harmonic reduction in addition, many controllers like p-q Theorem based controller, Fuzzy and gradient descent based neural network is also used. Results: The simulation results gives the compared source current wave forms for various controllers with individual harmonic mitigations. Conclusion: The pure utility current is obtained by using this intelligent neural filter without any additional components and without any extra controllers than the conventional methods.

  3. Non-neutralized Electric Current Patterns in Solar Active Regions: Origin of the Shear-Generating Lorentz Force

    Georgoulis, Manolis K; Mikic, Zoran

    2012-01-01

    Using solar vector magnetograms of the highest available spatial resolution and signal-to-noise ratio we perform a detailed study of electric current patterns in two solar active regions: a flaring/eruptive, and a flare-quiet one. We aim to determine whether active regions inject non-neutralized (net) electric currents in the solar atmosphere, responding to a debate initiated nearly two decades ago that remains inconclusive. We find that well-formed, intense magnetic polarity inversion lines (PILs) within active regions are the only photospheric magnetic structures that support significant net current. More intense PILs seem to imply stronger non-neutralized current patterns per polarity. This finding revises previous works that claim frequent injections of intense non-neutralized currents by most active regions appearing in the solar disk but also works that altogether rule out injection of non-neutralized currents. In agreement with previous studies, we also find that magnetically isolated active regions re...

  4. New hybrid active power filter for harmonic current suppression and reactive power compensation

    Biricik, Samet; Cemal Ozerdem, Ozgur; Redif, Soydan; Sezai Dincer, Mustafa

    2016-08-01

    In the case of undistorted and balanced grid voltages, low ratio shunt active power filters (APFs) can give unity power factors and achieve current harmonic cancellation. However, this is not possible when source voltages are distorted and unbalanced. In this study, the cost-effective hybrid active power filter (HAPF) topology for satisfying the requirements of harmonic current suppression and non-active power compensation for industry is presented. An effective strategy is developed to observe the effect of the placement of power capacitors and LC filters with the shunt APF. A new method for alleviating the negative effects of a nonideal grid voltage is proposed that uses a self-tuning filter algorithm with instantaneous reactive power theory. The real-time control of the studied system was achieved with a field-programmable gate array (FPGA) architecture, which was developed using the OPAL-RT system. The performance result of the proposed HAPF system is tested and presented under nonideal supply voltage conditions.

  5. Density-matrix renormalization-group study of current and activity fluctuations near nonequilibrium phase transitions.

    Gorissen, Mieke; Hooyberghs, Jef; Vanderzande, Carlo

    2009-02-01

    Cumulants of a fluctuating current can be obtained from a free-energy-like generating function, which for Markov processes equals the largest eigenvalue of a generalized generator. We determine this eigenvalue with the density-matrix renormalization group for stochastic systems. We calculate the variance of the current in the different phases, and at the phase transitions, of the totally asymmetric exclusion process. Our results can be described in the terms of a scaling ansatz that involves the dynamical exponent z . We also calculate the generating function of the dynamical activity (total number of configuration changes) near the absorbing-state transition of the contact process. Its scaling properties can be expressed in terms of known critical exponents. PMID:19391693

  6. Active current sheets and hot flow anomalies in Mercury's bow shock

    Uritsky, V M; Boardsen, S A; Sundberg, T; Raines, J M; Gershman, D J; Collinson, G; Sibeck, D; Khazanov, G V; Anderson, B J; Korth, H

    2013-01-01

    Hot flow anomalies (HFAs) represent a subset of solar wind discontinuities interacting with collisionless bow shocks. They are typically formed when the normal component of motional (convective) electric field points toward the embedded current sheet on at least one of its sides. The core region of an HFA contains hot and highly deflected ion flows and rather low and turbulent magnetic field. In this paper, we report first observations of HFA-like events at Mercury identified over a course of two planetary years. Using data from the orbital phase of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission, we identify a representative ensemble of active current sheets magnetically connected to Mercury's bow shock. We show that some of these events exhibit unambiguous magnetic and particle signatures of HFAs similar to those observed earlier at other planets, and present their key physical characteristics. Our analysis suggests that Mercury's bow shock does not only mediate the flo...

  7. Accumulation of slowly activating delayed rectifier potassium current (IKs) in canine ventricular myocytes

    Stengl, Milan; Volders, Paul G A; Thomsen, Morten Bækgaard; Spätjens, Roel L H M G; Sipido, Karin R; Vos, Marc A

    In guinea-pig ventricular myocytes, in which the deactivation of slowly activating delayed rectifier potassium current (IKs) is slow, IKs can be increased by rapid pacing as a result of incomplete deactivation and subsequent current accumulation. Whether accumulation of IKs occurs in dogs, in which...... revealed that the accumulation of canine IKs could occur, but only at rather short interpulse intervals (<100 ms). With action potential (AP) clamp commands of constant duration (originally recorded at rate of 2 Hz), an accumulation was only found at interpulse intervals close to 0 ms. Transmembrane...... potential recordings with high-resistance microelectrodes revealed, however, that at the fastest stimulation rates with normally captured APs (5 Hz) the interpulse interval exceeded 50 ms. This suggested that no IKs accumulation occurs, which was supported by the lack of effect of an IKs blocker, HMR 1556...

  8. Calcium-activated chloride current expression in axotomized sensory neurons: what for?

    Mathieu Boudes

    2012-03-01

    Full Text Available Calcium-activated chloride currents (CaCCs are activated by an increase in intracellular calcium concentration. Peripheral nerve injury induces the expression of CaCCs in a subset of adult sensory neurons in primary culture including mechano-and proprioceptors, though not nociceptors. Functional screenings of potential candidate genes established that Best1 is a molecular determinant for CaCC expression among axotomized sensory neurons, while Tmem16a accounts for inflammation-induced CaCC expression in nociceptors. In nociceptors, such CaCCs are preferentially activated under receptor-induced calcium mobilization contributing to cell excitability and pain. In axotomized mechano- and proprioceptors, CaCC activation does not promote electrical activity and prevents firing, a finding consistent with electrical silencing for growth competence of adult sensory neurons. In favor of a role in the process of neurite growth, CaCC expression is temporally correlated to neurons displaying a regenerative mode of growth. This perspective focuses on the molecular identity and role of CaCC in axotomized sensory neurons and the future directions to decipher the cellular mechanisms regulating CaCC during neurite (regrowth.

  9. Tonotopic Organization of the Hyperpolarization-activated Current (Ih in the Mammalian Medial Superior Olive

    Simon Lehnert

    2013-07-01

    Full Text Available Abstract Neuronal membrane properties can largely vary even within distinct morphological cell classes. The mechanisms and functional consequences of this diversity, however, are little explored. In the medial superior olive (MSO, a brainstem nucleus that performs binaural coincidence detection, membrane properties at rest are largely governed by the hyperpolarization-activated inward current (Ih which enables the temporally precise integration of excitatory and inhibitory inputs. Here, we report that Ih density varies along the putative tonotopic axis of the MSO with Ih being largest in ventral, high-frequency processing neurons. Also Ih half-maximal activation voltage and time constant are differentially distributed such that Ih of the putative high-frequency processing neurons activate faster and at more depolarized levels. Intracellular application of saturating concentrations of cyclic AMP removed the regional difference in hyperpolarization-activated cyclic nucleotide gated (HCN channel activation, but not Ih density. Experimental data in conjunction with a computational model suggest that increased Ih levels are helpful in counteracting temporal summation of phase-locked inhibitory inputs which is particularly prominent in high-frequency neurons.

  10. Should unfolded histograms be used to test hypotheses?

    Cousins, Robert D; Sun, Yipeng

    2016-01-01

    In many analyses in high energy physics, attempts are made to remove the effects of detector smearing in data by techniques referred to as "unfolding" histograms, thus obtaining estimates of the true values of histogram bin contents. Such unfolded histograms are then compared to theoretical predictions, either to judge the goodness of fit of a theory, or to compare the abilities of two or more theories to describe the data. When doing this, even informally, one is testing hypotheses. However, a more fundamentally sound way to test hypotheses is to smear the theoretical predictions by simulating detector response and then comparing to the data without unfolding; this is also frequently done in high energy physics, particularly in searches for new physics. One can thus ask: to what extent does hypothesis testing after unfolding data materially reproduce the results obtained from testing by smearing theoretical predictions? We argue that this "bottom-line-test" of unfolding methods should be studied more commonl...

  11. EVOLUTION OF RELATIVE MAGNETIC HELICITY AND CURRENT HELICITY IN NOAA ACTIVE REGION 11158

    Both magnetic and current helicities are crucial ingredients for describing the complexity of active-region magnetic structure. In this Letter, we present the temporal evolution of these helicities contained in NOAA active region 11158 during five days from 2011 February 12 to 16. The photospheric vector magnetograms of the Helioseismic and Magnetic Imager on board the Solar Dynamic Observatory were used as the boundary conditions for the coronal field extrapolation under the assumption of nonlinear force-free field, from which we calculated both relative magnetic helicity and current helicity. We construct a time-altitude diagram in which altitude distribution of the magnitude of current helicity density is displayed as a function of time. This diagram clearly shows a pattern of upwardly propagating current helicity density over two days prior to the X2.2 flare on February 15 with an average propagation speed of ∼36 m s–1. The propagation is synchronous with the emergence of magnetic flux into the photosphere, and indicative of a gradual energy buildup for the X2.2 flare. The time profile of the relative magnetic helicity shows a monotonically increasing trend most of the time, but a pattern of increasing and decreasing magnetic helicity above the monotonic variation appears prior to each of two major flares, M6.6 and X2.2, respectively. The physics underlying this bump pattern is not fully understood. However, the fact that this pattern is apparent in the magnetic helicity evolution but not in the magnetic flux evolution makes it a useful indicator in forecasting major flares.

  12. Geotectonic hypotheses at the beginning of the 21st century

    Strutinski, C.; Stan, R.; Puste, A.

    2003-01-01

    In this contribution to the volume honouring Ott Ch. Hilgenberg the main directions of thought in the field of geotectonics at the beginning of the 21st century are reviewed. However, because of its seminal importance for the geological thinking during most of the last century, the Wegener (continental drift) hypothesis is also included and opens the review. It is followed by the critical presentation of Plate tectonics and the hypotheses of Earth expansion, Surge tectonics and Wrench tectoni...

  13. Binary hypotheses for bipolar mass loss in transients

    Fitzpatrick, Benedict John Russell; Podsiadlowski, Philipp

    2012-01-01

    We investigate binary hypotheses for the formation of bipolar nebulae using the smoothed particle hydrodynamics code Gadget-2. In the general case, we present a parameter study of mass loss from very simple common envelope models, which seems to show a strongly bipolar trend for sufficiently oblate envelopes and low enough spiral-in injection energy. The density profiles of the envelopes produce differing structure within the ejecta. We also investigate 3 specific bipolar ma...

  14. f-divergences: Sufficiency, deficiency and testing of hypotheses

    Vajda, Igor; Liese, F.

    Toronto : Nova Publishers, 2008 - (Barnett, N.; Dragomir, S.), s. 113-149 ISBN 1-60021-943-8. - (Advances in Mathematical Inequalities) R&D Projects: GA MŠk(CZ) 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : divergence * sufficiency * testing errors * information gain * deficiency * exponential rate Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2009/SI/vajda-fdivergences sufficiency deficiency and testing of hypotheses.pdf

  15. Furious Frederich: Nietzsche’s neurosyphilis diagnosis and new hypotheses

    Charles André; André Rangel Rios

    2015-01-01

    The causes of Friedrich Nietzsche’s mental breakdown in early 1889 and of the subsequent slow decay to end-stage dementia along ten years will possibly remain open to debate. The diagnosis of syphilitic dementia paralytica, based only on medical anamnesis and physical examination, was considered indisputable by Otto Binswanger. On the other hand, taking into account recently described diseases, selectively collected evidence lend some support to alternative hypotheses: basal forebrain meningi...

  16. Single Phase Current-Source Active Rectifier for Traction: Control System Design and Practical Problems

    Jan Michalik

    2006-01-01

    Full Text Available This research has been motivated by industrial demand for single phase current-source active rectifier dedicated for reconstruction of older types of dc machine locomotives. This paper presents converters control structure design and simulations. The proposed converter control is based on the mathematical model and due to possible interaction with railway signaling and required low switching frequency employs synchronous PWM. The simulation results are verified by experimental tests performed on designed laboratory prototype of power of 7kVA

  17. Localization of endocardial ectopic activity by means of noninvasive endocardial surface current density reconstruction

    Localization of the source of cardiac ectopic activity has direct clinical benefits for determining the location of the corresponding ectopic focus. In this study, a recently developed current-density (CD)-based localization approach was experimentally evaluated in noninvasively localizing the origin of the cardiac ectopic activity from body-surface potential maps (BSPMs) in a well-controlled experimental setting. The cardiac ectopic activities were induced in four well-controlled intact pigs by single-site pacing at various sites within the left ventricle (LV). In each pacing study, the origin of the induced ectopic activity was localized by reconstructing the CD distribution on the endocardial surface of the LV from the measured BSPMs and compared with the estimated single moving dipole (SMD) solution and precise pacing site (PS). Over the 60 analyzed beats corresponding to ten pacing sites (six for each), the mean and standard deviation of the distance between the locations of maximum CD value and the corresponding PSs were 16.9 mm and 4.6 mm, respectively. In comparison, the averaged distance between the SMD locations and the corresponding PSs was slightly larger (18.4 ± 3.4 mm). The obtained CD distribution of activated sources extending from the stimulus site also showed high consistency with the endocardial potential maps estimated by a minimally invasive endocardial mapping system. The present experimental results suggest that the CD method is able to locate the approximate site of the origin of a cardiac ectopic activity, and that the distribution of the CD can portray the propagation of early activation of an ectopic beat.

  18. Potassium currents inhibition by gambierol analogs prevents human T lymphocyte activation.

    Rubiolo, J A; Vale, C; Martín, V; Fuwa, H; Sasaki, M; Botana, L M

    2015-07-01

    Gambierol is a marine polycyclic ether toxin, produced along with ciguatoxin congeners by the dinoflagellate Gambierdiscus toxicus. We have recently reported that two truncated skeletal analogs of gambierol comprising the EFGH- and BCDEFGH-rings of the parent compound showed similar potency to gambierol on voltage-gated potassium channels (Kv) inhibition in neurons. Gambierol and its truncated analogs share the main crucial elements for biological activity, which are the C28=C29 double bond within the H-ring and the unsaturated side chain. Since Kv channels are critical for the regulation of calcium signaling, proliferation, secretion and migration in human T lymphocytes, we evaluated the activity of both the tetracyclic and heptacyclic analogs of gambierol on potassium currents in resting T lymphocyte and their effects on interleukin-2 (IL-2) release and gene expression in activated T lymphocytes. The results presented in this work clearly demonstrate that both truncated analogs of gambierol inhibit Kv channels present in resting T lymphocytes (Kv1.3) and prevented lymphocyte activation by concanavalin A. The main effects of the heptacyclic and tetracyclic analogs of gambierol in human T cells are: (1) inhibition of potassium channels in resting and concanavalin-activated T cells in the nanomolar range, (2) inhibition of IL-2 release from concanavalin-activated T cells and (3) negatively affect the expression of genes involved in cell proliferation and immune response observed in concanavalin-activated lymphocytes. These results together with the lack of toxicity in this cellular model, indicates that both analogs of gambierol have additional potential for the development of therapeutic tools in autoimmune diseases. PMID:25155189

  19. Active Protection System for AFV application – Current trends and future requirement – A study report

    Vivek.R

    2012-07-01

    Full Text Available A combat vehicle is a self-propelled weaponplatform. Light Weight and high performance arethe key factors for the design of a combat vehicle.Most of the weight is distributed to structuralarmour purposes. Rolled Homogenous Armour(RHA steel and composite armour played adominant role to counter these threats. But thethreat to the combat vehicles has increasedmanifold due to advancement in weapontechnologies and there is a necessity of protectingthe vehicles from these threats. The protections bymeans of RHA steel will lead to increase in weight,which affects the mobility of the vehicle. Hencethere is a need to adopt active protectiontechnologies to effectively counter the incominganti-tank threats/ ammunitions before hitting thevehicle thereby enhancing its survivability. Thispaper highlights the current trends and futurerequirement in the field of Active Protectiontechnologies.

  20. Strategic Classification and Examination of the Development of Current Airline Alliance Activities

    Wang, Zhi H.; Evans, Michael

    2002-01-01

    Previous research argues that despite the fact that strategic alliances have become an important feature of the world airline industry, little rigorous analysis has been done on the effects of these alliances. This is partially because there is a lack of precise definitions to specify different types of airline alliances in the literature. This research identifies several categories of airline alliances through a strategic classification of the current alliance activities involving the major airlines for the period 1989 to 1999. The classification enables this research to examine how strategic alliance activities are evolving, particularly to compare how airlines in North America, the European Union and the Asia Pacific region have committed to different alliances. Findings show that there is a significant difference between the number and scope of alliances adopted in the three aviation markets. These findings facilitate research to further analyse the impact of market liberalization on various formations of strategic airline alliances.

  1. The role of observational uncertainties in testing model hypotheses

    Westerberg, I. K.; Birkel, C.

    2012-12-01

    Knowledge about hydrological processes and the spatial and temporal distribution of water resources is needed as a basis for managing water for hydropower, agriculture and flood-protection. Conceptual hydrological models may be used to infer knowledge on catchment functioning but are affected by uncertainties in the model representation of reality as well as in the observational data used to drive the model and to evaluate model performance. Therefore, meaningful hypothesis testing of the hydrological functioning of a catchment requires such uncertainties to be carefully estimated and accounted for in model calibration and evaluation. The aim of this study was to investigate the role of observational uncertainties in hypothesis testing, in particular whether it was possible to detect model-structural representations that were wrong in an important way given the uncertainties in the observational data. We studied the relatively data-scarce tropical Sarapiqui catchment in Costa Rica, Central America, where water resources play a vital part for hydropower production and livelihood. We tested several model structures of varying complexity as hypotheses about catchment functioning, but also hypotheses about the nature of the modelling errors. The tests were made within a learning framework for uncertainty estimation which enabled insights into data uncertainties, suitable model-structural representations and appropriate likelihoods. The observational uncertainty in discharge data was estimated from a rating-curve analysis and precipitation measurement errors through scenarios relating the error to, for example, canopy interception, wind-driven rain and the elevation gradient. The hypotheses were evaluated in a posterior analysis of the simulations where the performance of each simulation was analysed relative to the observational uncertainties for the entire hydrograph as well as for different aspects of the hydrograph (e.g. peak flows, recession periods, and base flow

  2. Monitoring the excitability of neocortical efferent neurons to direct activation by extracellular current pulses.

    Swadlow, H A

    1992-08-01

    1. Extracellular action potentials were recorded from antidromically activated efferent neurons in visual, somatosensory, and motor cortex of the awake rabbit using low-impedance metal microelectrodes. Efferent neurons were also activated by current pulses delivered near the soma [juxtasomal current pulses (JSCPs)] through the recording microelectrode. Action potentials generated by JSCPs were not directly observed (because of the stimulus artifact), but were inferred with the use of a collision paradigm. Efferent populations studied include callosal neurons [CC (n = 80)], ipsilateral corticocortical neurons [C-IC (n = 21)], corticothalamic neurons of layer 6 [CF-6 (n = 57)], and descending corticofugal neurons of layer 5 [CF-5, corticotectal neurons of the visual cortex (n = 48)]. 2. Most CC neurons (45/46) and all C-IC (8/8) and CF-6 neurons (39/39) were directly activated by JSCPs at near-threshold intensities. Some CF-5 neurons (9/38), however, showed evidence of indirect activation. All efferent classes had similar current thresholds (means 1.85-2.10 microA) to direct activation by JSCPs, and thresholds were inversely related to extracellular spike amplitude. For each neuron, the range of JSCP intensities that generated response probabilities of between 0.2 and 0.8 was measured, and this "range of uncertainty" was significantly greater in CF-5 neurons (mean 32.7% of threshold) than in CC (mean 19.0%) or CF-6 (mean 20.4%) neurons. 3. Several factors indicate that the threshold of efferent neurons to JSCPs is very sensitive to excitatory and inhibitory synaptic inputs. Iontophoretic applications of gamma-aminobutyric acid (GABA) increased the threshold to JSCPs, and glutamate reduced the threshold. Electrical stimulation of afferent pathways at intensities just below threshold for eliciting action potentials resulted in a dramatic decrease in JSCP threshold. This initial short-latency threshold decrease was specific to stimulation of particular afferent pathways

  3. Alternative splicing at C terminus of Ca(V)1.4 calcium channel modulates calcium-dependent inactivation, activation potential, and current density.

    Tan, Gregory Ming Yeong; Yu, Dejie; Wang, Juejin; Soong, Tuck Wah

    2012-01-01

    The Ca(V)1.4 voltage-gated calcium channel is predominantly expressed in the retina, and mutations to this channel have been associated with human congenital stationary night blindness type-2. The L-type Ca(V)1.4 channel displays distinct properties such as absence of calcium-dependent inactivation (CDI) and slow voltage-dependent inactivation (VDI) due to the presence of an autoinhibitory domain (inhibitor of CDI) in the distal C terminus. We hypothesized that native Ca(V)1.4 is subjected to extensive alternative splicing, much like the other voltage-gated calcium channels, and employed the transcript scanning method to identify alternatively spliced exons within the Ca(V)1.4 transcripts isolated from the human retina. In total, we identified 19 alternative splice variations, of which 16 variations have not been previously reported. Characterization of the C terminus alternatively spliced exons using whole-cell patch clamp electrophysiology revealed a splice variant that exhibits robust CDI. This splice variant arose from the splicing of a novel alternate exon (43*) that can be found in 13.6% of the full-length transcripts screened. Inclusion of exon 43* inserts a stop codon that truncates half the C terminus. The Ca(V)1.4 43* channel exhibited robust CDI, a larger current density, a hyperpolarized shift in activation potential by ∼10 mV, and a slower VDI. Through deletional experiments, we showed that the inhibitor of CDI was responsible for modulating channel activation and VDI, in addition to CDI. Calcium currents in the photoreceptors were observed to exhibit CDI and are more negatively activated as compared with currents elicited from heterologously expressed full-length Ca(V)1.4. Naturally occurring alternative splice variants may in part contribute to the properties of the native Ca(V)1.4 channels. PMID:22069316

  4. Current topics in active and intelligent food packaging for preservation of fresh foods.

    Lee, Seung Yuan; Lee, Seung Jae; Choi, Dong Soo; Hur, Sun Jin

    2015-11-01

    The purpose of this review is to provide an overview of current packaging systems, e.g. active packaging and intelligent packaging, for various foods. Active packaging, such as modified atmosphere packaging (MAP), extends the shelf life of fresh produce, provides a high-quality product, reduces economic losses, including those caused by delay of ripening, and improves appearance. However, in active packaging, several variables must be considered, such as temperature control and different gas formulations with different product types and microorganisms. Active packaging refers to the incorporation of additive agents into packaging materials with the purpose of maintaining or extending food product quality and shelf life. Intelligent packaging is emerging as a potential advantage in food processing and is an especially useful tool for tracking product information and monitoring product conditions. Moreover, intelligent packaging facilitates data access and information exchange by altering conditions inside or outside the packaging and product. In spite of these advantages, few of these packaging systems are commercialized because of high cost, strict safety and hygiene regulations or limited consumer acceptance. Therefore more research is needed to develop cheaper, more easily applicable and effective packaging systems for various foods. PMID:25892577

  5. An 11 μ w, two-electrode transimpedance biosignal amplifier with active current feedback stabilization.

    Inan, O T; Kovacs, G T A

    2010-04-01

    A novel two-electrode biosignal amplifier circuit is demonstrated by using a composite transimpedance amplifier input stage with active current feedback. Micropower, low gain-bandwidth product operational amplifiers can be used, leading to the lowest reported overall power consumption in the literature for a design implemented with off-the-shelf commercial integrated circuits (11 μW). Active current feedback forces the common-mode input voltage to stay within the supply rails, reducing baseline drift and amplifier saturation problems that can be present in two-electrode systems. The bandwidth of the amplifier extends from 0.05-200 Hz and the midband voltage gain (assuming an electrode-to-skin resistance of 100 kΩ) is 48 dB. The measured output noise level is 1.2 mV pp, corresponding to a voltage signal-to-noise ratio approaching 50 dB for a typical electrocardiogram (ECG) level input of 1 mVpp. Recordings were taken from a subject by using the proposed two-electrode circuit and, simultaneously, a three-electrode standard ECG circuit. The residual of the normalized ensemble averages for both measurements was computed, and the power of this residual was 0.54% of the power of the standard ECG measurement output. While this paper primarily focuses on ECG applications, the circuit can also be used for amplifying other biosignals, such as the electroencephalogram. PMID:23853316

  6. Current research activity in the measurement of thorium and the identification of future research needs

    A pre-requisite in the setting and enforcement of regulatory limits for exposure to thorium in the workplace is that thorium and its progeny can be accurately measured. Literature surveys have shown that the majority of thorium measurements were performed using either a radiochemical technique, such as alpha or gamma spectroscopy, or ICP-MS. For many methods, there was a separation step to isolate and pre-concentrate thorium from the sample matrix. Thorium was most commonly measured in geological matrices and industrial materials. A survey of current research activity was performed through distribution of a questionnaire to laboratories and national centres. From the responses, four areas of current activity were identified: (i) development of methods for low level thorium determination, (ii) biological monitoring and metabolism of thorium, (iii) environmental monitoring for thorium, and (iv) health risks from X ray contract media. Two key areas for priority research were identified by the thorium Thematic Network: namely sample preparation methods and for traceable standards and reference materials for thorium analysis. (author)

  7. How doctors generate diagnostic hypotheses: a study of radiological diagnosis with functional magnetic resonance imaging.

    Marcio Melo

    Full Text Available BACKGROUND: In medical practice, diagnostic hypotheses are often made by physicians in the first moments of contact with patients; sometimes even before they report their symptoms. We propose that generation of diagnostic hypotheses in this context is the result of cognitive processes subserved by brain mechanisms that are similar to those involved in naming objects or concepts in everyday life. METHODOLOGY AND PRINCIPAL FINDINGS: To test this proposal we developed an experimental paradigm with functional magnetic resonance imaging (fMRI using radiological diagnosis as a model. Twenty-five radiologists diagnosed lesions in chest X-ray images and named non-medical targets (animals embedded in chest X-ray images while being scanned in a fMRI session. Images were presented for 1.5 seconds; response times (RTs and the ensuing cortical activations were assessed. The mean response time for diagnosing lesions was 1.33 (SD ±0.14 seconds and 1.23 (SD ±0.13 seconds for naming animals. 72% of the radiologists reported cogitating differential diagnoses during trials (3.5 seconds. The overall pattern of cortical activations was remarkably similar for both types of targets. However, within the neural systems shared by both stimuli, activation was significantly greater in left inferior frontal sulcus and posterior cingulate cortex for lesions relative to animals. CONCLUSIONS: Generation of diagnostic hypotheses and differential diagnoses made through the immediate visual recognition of clinical signs can be a fast and automatic process. The co-localization of significant brain activation for lesions and animals suggests that generating diagnostic hypotheses for lesions and naming animals are served by the same neuronal systems. Nevertheless, diagnosing lesions was cognitively more demanding and associated with more activation in higher order cortical areas. These results support the hypothesis that medical diagnoses based on prompt visual recognition of

  8. Electric Current Activated Combustion Synthesis and Chemical Ovens Under Terrestrial and Reduced Gravity Conditions

    Unuvar, C.; Fredrick, D.; Anselmi-Tamburini, U.; Manerbino, A.; Guigne, J. Y.; Munir, Z. A.; Shaw, B. D.

    2004-01-01

    Combustion synthesis (CS) generally involves mixing reactants together (e.g., metal powders) and igniting the mixture. Typically, a reaction wave will pass through the sample. In field activated combustion synthesis (FACS), the addition of an electric field has a marked effect on the dynamics of wave propagation and on the nature, composition, and homogeneity of the product as well as capillary flow, mass-transport in porous media, and Marangoni flows, which are influenced by gravity. The objective is to understand the role of an electric field in CS reactions under conditions where gravity-related effects are suppressed or altered. The systems being studied are Ti+Al and Ti+3Al. Two different ignition orientations have been used to observe effects of gravity when one of the reactants becomes molten. This consequentially influences the position and concentration of the electric current, which in turn influences the entire process. Experiments have also been performed in microgravity conditions. This process has been named Microgravity Field Activated Combustion Synthesis (MFACS). Effects of gravity have been demonstrated, where the reaction wave temperature and velocity demonstrate considerable differences besides the changes of combustion mechanisms with the different high currents applied. Also the threshold for the formation of a stable reaction wave is increased under zero gravity conditions. Electric current was also utilized with a chemical oven technique, where inserts of aluminum with minute amounts of tungsten and tantalum were used to allow observation of effects of settling of the higher density solid particles in liquid aluminum at the present temperature profile and wave velocity of the reaction.

  9. Fuzzy Hypotheses Testing in the Framework of Fuzzy Logic

    Holeňa, Martin

    2004-01-01

    Roč. 145, - (2004), s. 229-252. ISSN 0165-0114 R&D Projects: GA AV ČR IAA1030004; GA MŠk OC 274.001 Grant ostatní: COST(XE) Action 274 TARSKI Institutional research plan: CEZ:AV0Z1030915 Keywords : non-classical logics * fuzzy predicate calculus * basic fuzzy logic * generalized quantifiers * fuzzy statistics and data analysis * vague hypotheses * vague significance level * method Guha Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.734, year: 2004

  10. CURRENT STATUS OF RESEARCH PROJECT ACTIVITIES IN MEDICAL UNIVERSITIES IN BULGARIA.

    Svetoslav Garov

    2013-07-01

    Full Text Available Introduction: In Bulgaria there are five medical universities: in the cities of Sofia, Plovdiv, Varna, Pleven and Stara Zagora. Their main mission is training specialists in the fields of medicine and health care, increasing their qualification by means of postgraduate education and performing research activities. One of medical universities’ top priorities is encouraging research activities mainly aimed at preparation and implementation of research projects. Aim: The purpose of our study is to examine the current status of research project activities in Bulgarian medical universities.Material and methods: In order to define the science competitions related to Bulgarian medical universities we have applied a documentary and sociological approach. Results: Research projects that Bulgarian medical universities can apply for are divided into two groups – national and international. The most significant international projects are European ones since Bulgaria is an EU member state and this allows us to participate in such projects. Conclusion: Universities should strive for establishing even better conditions for encouraging application for research projects aimed at developing competent and experienced staff, even though the majority of them may not obtain approval for financing.The changes in the situation regarding Bulgarian science require the implementation and development of more research staff motivated to improve their knowledge and skills in the relevant dynamically changing competition and project field.

  11. Overview of PV activities in Japan: current status and future prospects

    In Japan, activities for dissemination of PV systems have expanded among the national and local governments, industries, academic circles, nonprofit organizations (NPOs), and consumers ever since the Japanese Government laid out the Basic Guidelines for New Energy Introduction in 1994. Particularly, the continuous dissemination programs by the Ministry of Economy, Trade, and Industry (METI) based on the size of PV market has greatly contributed Japan PV industries and the successful creation of the initial market of PV systems. Cumulative installed PV capacity increased from 31.2 MW in 1994 to 859.6 MW in 2003, and 1 GW level is already in sight for 2004. As a result, solar cell/ module manufactures, housing industry, utilities, METI and other ministries and agencies, local governments, NPOs, end-users, etc. are actively promoting deployment of PV systems and the PV market is activated toward achieving 4,820 MW of the target capacity for 2010. The purpose of this paper is to provide an overview of the dissemination process of PV systems by sector and current status of Japan PV market and to forecast the future development to establish the self-sustainable PV market from the perspective of measures and policies, systems, the industrial structure and the PV market. (authors)

  12. Evaluation of silver-titanium implants activated by low intensity direct current for orthopedic infection control: An in vitro and in vivo study.

    Cavanaugh, Daniel L; Tan, Zhuo George; Norris, James P; Hardee, Amelia; Weinhold, Paul S; Dahners, Laurence E; Orndorff, Paul E; Shirwaiker, Rohan A

    2016-07-01

    Silver is an alternative antimicrobial of interest for the prophylaxis of prosthetic infections and electrical activation is known to augment its oligodynamic efficacy. In this study, we evaluated the in vitro and in vivo efficacy of a silver (Ag)-titanium (Ti) implant activated by 30 µA direct current compared with three controls - passive Ag-Ti, active Ti-Ti, and passive Ti-Ti. We hypothesized that the experimental group would provide better resistance to pathogenic colonization on the implant. Modified Kirby-Bauer technique was used to evaluate in vitro efficacy of the four groups against five bacteria and one fungus. For in vivo evaluation, forty-eight rats were divided into four groups. The implant was secured in a wound cavity along the posterior margin of the femur. The wound was inoculated with 7.5 × 10(5) CFU of Staphylococcus aureus. Rats were euthanized 14 days postsurgery and quantitative cultures were performed on the implant segments and the wound cavity tissue. In vitro tests showed that the growth of all six pathogens was inhibited around the active Ag anodes of the experimental group. In vivo, none of the four groups were able to prevent wound infection, but the experimental group resulted in reduced colonization. The mean bacterial loads on Ti segments were significantly lower in the implants which also had an Ag segment (p = 0.0007), and this effect was more pronounced with electrical activation (p = 0.0377). The results demonstrate the antimicrobial potential of LIDC-activated Ag-Ti implants. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1023-1031, 2016. PMID:25996127

  13. On the Modeling of Electrical Effects Experienced by Space Explorers During Extra Vehicular Activities: Intracorporal Currents, Resistances, and Electric Fields

    Cela, Carlos J.; Loizos, Kyle; Lazzi, Gianluca; Hamilton, Douglas; Lee, Raphael C.

    2011-01-01

    Recent research has shown that space explorers engaged in Extra Vehicular Activities (EVAs) may be exposed, under certain conditions, to undesired electrical currents. This work focuses on determining whether these undesired induced electrical currents could be responsible for involuntary neuromuscular activity in the subjects, possibly caused by either large diameter peripheral nerve activation or reflex activity from cutaneous afferent stimulation. An efficient multiresolution variant of the admittance method along with a millimeter-resolution model of a male human body were used to calculate induced electric fields, resistance between contact electrodes used to simulate the potential exposure condition, and currents induced in the human body model. Results show that, under realistic exposure conditions using a 15V source, current density magnitudes and total current injected are well above previously reported startle reaction thresholds. This indicates that, under the considered conditions, the subjects could experience involuntary motor response.

  14. Myocardial perfusion imaging in Denmark: activity from 1997 to 2001 and current practice

    A questionnaire was sent to all departments of nuclear medicine in Denmark (n=20) asking for details of myocardial perfusion imaging (MPI), including the number of patients examined each year from 1997 to 2001 and the current clinical and technical practice. All (100%) departments replied, and the survey thus covers all MPI performed in Denmark during the period in question. The number of MPI studies (examined patients) was 2,531 in 1997 (0.47 MPI/1,000/year) and 4,961 (0.93 MPI/1,000/year) in 2001, which is a doubling in activity in 5 years. Nineteen (95%) of the Danish departments performed MPI in 2001, and 14 (74%) of these reported that activity had increased over the past 5 years. MPI activity was unevenly distributed between hospitals and regions. In 2001, the university hospitals in the central Copenhagen region (capital) accounted for the highest MPI activity (2.00/1,000/year), while the non-university hospitals in general had the lowest activity rate (0.73/1,000/year). The most pronounced increment found in the period was observed in the university hospitals outside Copenhagen, where activity increased by 300% from 0.44/1,000/year in 1997 to 1.33/1,000/year in 2001. All departments providing MPI used tomographic acquisition technique and all departments used technetium tracers. The more sophisticated techniques of MPI - gated acquisition, attenuation correction and iterative reconstruction - were used in 74%, 32% and 42% of departments, respectively. The stress mode in perfusion studies was dipyridamole/adenosine in 76%, exercise in 18% and dobutamine in 6%. Despite these encouraging figures, MPI activity for 2001 remained well below what is recommended by other national and international societies. The anticipated further increase in nuclear cardiology is encouraging, but the nuclear medicine community needs to address the issues that prevent it from keeping up with demand. In general, the restricted camera time and the limited number of trained personnel

  15. Attribution of detected changes in streamflow using multiple working hypotheses

    S. Harrigan

    2013-10-01

    Full Text Available This paper revisits a widely cited study of the Boyne catchment in the east of Ireland that attributed a change in streamflow during the mid-1970s to increased precipitation linked to a shift in the North Atlantic Oscillation. Using the method of Multiple Working Hypotheses we explore a wider set of potential drivers of hydrological change. Rainfall-runoff models are employed to reconstruct streamflow to isolate the effect of climate taking account of both model structure and parameter uncertainty. The Mann–Kendall test for monotonic trend and Pettitt change point test are applied to explore signatures of change. Different to earlier work, arterial drainage and the simultaneous onset of field drainage in the 1970s and early 1980s were inferred to be the predominant driver of change within the Boyne. There is evidence that a change in precipitation regime is also present, albeit to a lesser extent. This new explanation posits that multiple drivers acting simultaneously were responsible for the observed change. This work highlights the utility of the Multiple Working Hypotheses framework in moving towards more rigorous attribution, which is an important part of managing unfolding impacts on hydrological systems.

  16. On Consistent Nonparametric Statistical Tests of Symmetry Hypotheses

    Jean-François Quessy

    2016-05-01

    Full Text Available Being able to formally test for symmetry hypotheses is an important topic in many fields, including environmental and physical sciences. In this paper, one concentrates on a large family of nonparametric tests of symmetry based on Cramér–von Mises statistics computed from empirical distribution and characteristic functions. These tests possess the highly desirable property of being universally consistent in the sense that they detect any kind of departure from symmetry as the sample size becomes large. The asymptotic behaviour of these test statistics under symmetry is deduced from the theory of first-order degenerate V-statistics. The issue of computing valid p-values is tackled using the multiplier bootstrap method suitably adapted to V-statistics, yielding elegant, easy-to-compute and quick procedures for testing symmetry. A special focus is put on tests of univariate symmetry, bivariate exchangeability and reflected symmetry; a simulation study indicates the good sampling properties of these tests. Finally, a framework for testing general symmetry hypotheses is introduced.

  17. Transcranial Direct Current Stimulation Modulates Cortical Neuronal Activity in Alzheimer's Disease

    Marceglia, Sara; Mrakic-Sposta, Simona; Rosa, Manuela; Ferrucci, Roberta; Mameli, Francesca; Vergari, Maurizio; Arlotti, Mattia; Ruggiero, Fabiana; Scarpini, Elio; Galimberti, Daniela; Barbieri, Sergio; Priori, Alberto

    2016-01-01

    Quantitative electroencephalography (qEEG) showed that Alzheimer's disease (AD) is characterized by increased theta power, decreased alpha and beta power, and decreased coherence in the alpha and theta band in posterior regions. These abnormalities are thought to be associated with functional disconnections among cortical areas, death of cortical neurons, axonal pathology, and cholinergic deficits. Since transcranial Direct Current Stimulation (tDCS) over the temporo-parietal area is thought to have beneficial effects in patients with AD, in this study we aimed to investigate whether tDCS benefits are related to tDCS-induced changes in cortical activity, as represented by qEEG. A weak anodal current (1.5 mA, 15 min) was delivered bilaterally over the temporal-parietal lobe to seven subjects with probable AD (Mini-Mental State Examination, MMSE score >20). EEG (21 electrodes, 10–20 international system) was recorded for 5 min with eyes closed before (baseline, t0) and 30 min after anodal and cathodal tDCS ended (t1). At the same time points, patients performed a Word Recognition Task (WRT) to assess working memory functions. The spectral power and the inter- and intra-hemispheric EEG coherence in different frequency bands (e.g., low frequencies, including delta and theta; high frequencies, including alpha and beta) were calculated for each subject at t0 and t1. tDCS-induced changes in EEG neurophysiological markers were correlated with the performance of patients at the WRT. At baseline, qEEG features in AD patients confirmed that the decreased high frequency power was correlated with lower MMSE. After anodal tDCS, we observed an increase in the high-frequency power in the temporo-parietal area and an increase in the temporo-parieto-occipital coherence that correlated with the improvement at the WRT. In addition, cathodal tDCS produced a non-specific effect of decreased theta power all over the scalp that was not correlated with the clinical observation at the WRT

  18. Feeding activity of mussels Mytilus edulis related to near-bed currents and phytoplankton biomass

    Dolmer, Per

    . During day 3 and day 4 the near-bed current velocities increased to 6.5 and 3.9 cm s(-1). respectively, and the Chl-a was homogeneously distributed in the water column. Now only 17 and 25% of the mussels had closed valves and they accumulated a larger amount of Chl-a. The actual population filtration...... rates were estimated from the density of active mussels times the estimated filtration rates (based on the gap size of the mussels and literature values for corresponding filtration rates). Actual population filtration rates ranged from 6.4 to 22.8 m(3) m(-2) d(-1) on days 1 and 3, respectively......, corresponding to 27 and 98% of the estimated population filtration capacity. (C) 2000 Elsevier Science B.V. All rights reserved....

  19. Inclusive pedagogy in Australian universities: A review of current policies and professional development activities

    Danielle Hitch

    2015-03-01

    Full Text Available This article reports on activities undertaken by Australian universities to support academic staff to provide inclusive teaching. The findings of two lines of inquiry are reported - a desktop audit of the presence of inclusive teaching or universal design for learning (UDL in publically available policies and procedures documents, and a survey of the methods adopted to build staff capacity to provide inclusive teaching and learning. Just over a third (34.21% of Australian universities referred to inclusive teaching or UDL in their policies and procedures. A wide range of current practices in professional development for inclusive teaching was reported, with the most frequent being one-off workshops focussing on accommodating specific groups of students. Improved institutional support through policies, procedures and professional development would enable Australian higher education teachers to provide quality inclusive teaching to all students.

  20. LOCAL TWIST AND CURRENT HELICITY DISTRIBUTIONS OF ACTIVE REGION NOAA 10930

    Hinode high-quality vector magnetograms and G-band data are utilized to study the distributions of local twist α z and current helicity hc on the active region of NOAA 10930. The new findings are as follows. (1) The patches of positive and negative helicities were intermixed showing a mesh pattern in the umbra and a thread pattern in the penumbra. (2) For its main stable sunspot (MSS), there was a positive-helicity patch accounting for ∼43% of the umbra area surrounding the inner umbra, which had a predominantly negative helicity. For its minor rotating sunspot (MRS), there was a negative-helicity patch appearing in the umbra. (3) The fine distributions of α z and hc on a penumbral filament indicated that it may be possible for the two opposite helicities to coexist in a filament and their magnitudes were nearly equivalent.

  1. OECD/NEA expert group on uncertainty analysis for criticality safety assessment: current activities - 295

    The expert group (EG) on Uncertainty Analysis for Criticality Safety Assessment (UACSA) was established within the OECD/NEA Working Party on Nuclear Criticality Safety in December 2007 to promote exchange of information on related topics; compare methods and software tools for uncertainty analysis; test their performance; and assist in selection/development of safe and efficient methodologies. At the current stage, the work of the group is focused on approaches for validation of criticality calculations. With the diversity of the approaches to validate criticality calculations, a thorough description of each approach and assessment of its performance is useful to the criticality safety community. Developers, existing and potential practitioners as well as reviewers of assessments using those approaches should benefit from this effort. Exercise Phase I was conducted in order to illustrate predictive capabilities of criticality validation approaches, which include similarity assessment, definition of keff bias and bias uncertainty, and selection of benchmarks. The approaches and results of the exercises will be thoroughly documented in a pending state-of-the-art report from the EG. This paper provides an overview of current and future activities for the EG, a summary of the participant-contributed validation approaches, and a synthesis of the results for the exercises. (authors)

  2. 76 FR 45262 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    2011-07-28

    ... Collection; Comment Request; Current Good Manufacturing Practices and Related Regulations for Blood and Blood... current good manufacturing practice (CGMP) and related regulations for blood and blood components; and... of information technology. Current Good Manufacturing Practices and Related Regulations for Blood...

  3. Current activities and future trends in reliability analysis and probabilistic safety assessment in Hungary

    In Hungary reliability analysis (RA) and probabilistic safety assessment (PSA) of nuclear power plants was initiated 3 years ago. First, computer codes for automatic fault tree analysis (CAT, PREP) and numerical evaluation (REMO, KITT1,2) were adapted. Two main case studies - detailed availability/reliability calculation of diesel sets and analysis of safety systems influencing event sequences induced by large LOCA - were performed. Input failure data were taken from publications, a need for failure and reliability data bank was revealed. Current and future activities involves: setup of national data bank for WWER-440 units; full-scope level-I PSA of PAKS NPP in Hungary; operational safety assessment of particular problems at PAKS NPP. In the present article the state of RA and PSA activities in Hungary, as well as the main objectives of ongoing work are described. A need for international cooperation (for unified data collection of WWER-440 units) and for IAEA support (within Interregional Program INT/9/063) is emphasized. (author)

  4. Current status of information transfer activity on food irradiation and consumer attitudes in Japan

    Furuta, Masakazu

    2004-09-01

    For the purpose of public education of radiation and radiation-related technology towards school kids and their parents through efficient information transfer, ''RADIATION FAIR—the relationship between daily life and radiation" has been successfully held at Kintetsu Department Store, one of the major departmental stores in downtown Osaka, the second largest city in Japan during summer vacation in every August for 19 years. Currently various irradiated products available in our daily life including irradiated potatoes and spices were displayed together with explanatory panels and attractions. The number of participants has increased every year and constantly exceeded 20,000 in recent years. This activity has become a good medium for the consumer to recognize the quality of the irradiated potatoes which has been distributed in the market since 1974, and irradiated spices, the next candidate for the clearance under examination by Japanese government. Taking advantage of this opportunity, we have demonstrated toward the participants that irradiation-decontaminated spices are superior to conventional heat-treated ones in aromatic quality as well as conducting survey of the visitor's feeling on radiation and irradiated foods. These activities would be potentially effective to facilitate public acceptance of irradiation decontamination of spices.

  5. Current status of information transfer activity on food irradiation and consumer attitudes in Japan

    For the purpose of public education of radiation and radiation-related technology towards school kids and their parents through efficient information transfer, 'RADIATION FAIR - the relationship between daily life and radiation' has been successfully held at Kintetsu Department Store, one of the major departmental stores in downtown Osaka, the second largest city in Japan during summer vacation in every August for 19 years. Currently various irradiated products available in our daily life including irradiated potatoes and spices were displayed together with explanatory panels and attractions. The number of participants has increased every year and constantly exceeded 20,000 in recent years. This activity has become a good medium for the consumer to recognize the quality of the irradiated potatoes which has been distributed in the market since 1974, and irradiated spices, the next candidate for the clearance under examination by Japanese government. Taking advantage of this opportunity, we have demonstrated toward the participants that irradiation-decontaminated spices are superior to conventional heat-treated ones in aromatic quality as well as conducting survey of the visitor's feeling on radiation and irradiated foods. These activities would be potentially effective to facilitate public acceptance of irradiation decontamination of spices

  6. Current research activities for landmine detection by nuclear technique in Libya

    This paper gives a description to the current research activity carried by the research team which is concerned with the application of nuclear techniques for landmine detection. The activities are technically and financially supported by the IAEA through a TC project Lib/1/006. The IAEA has provided the project with two 3He detectors and some electronic equipment to install a detection system based on measuring thermal neutrons backscattered from the buried object. Also a detection system based on measuring the γ rays emitted from the hidden object through the interrogation of its elemental nuclei by fast and thermal neutrons will be installed. Theoretical and experimental studies are performed when neutrons of different energies are used. Calculations are performed using a Monte Carlo MCNP or Geant-3 Code. This code is used to assess the thermal neutron flux backscattered from plain soil and soil embedded with landmines of different amount of explosive. Measurements are performed to measure the backscattered thermal neutrons from a landmine with different amount of explosive material which is buried in ground at different depths. The obtained results are presented in the form of displayed spectra for γ rays and thermal neutron fluxes of landmines buried at different depth in ground. The analyses of the obtained data can be used to show the strength and weakness of the applied methods for landmine detection in different environmental conditions. (author)

  7. An Overview of the Current Research Activities for Landmine Detection by Nuclear Techniques in Libya

    This paper gives a description for the current research activity carried by the research team which is concerned with the application of nuclear techniques for landmine detection. The activities are technically and financially supported by the IAEA through a TC project LIB / 1 / 006. The IAEA has provided the project with two 3He detectors and some electronic equipment to install a detection system based on measuring thermal neutrons backscattered from the buried object. Also a detection system based on measuring the gamma-rays emitted from the hidden object through the interrogation of its elemental nuclei by fast and thermal neutrons was installed. Further, theoretical studies were performed to calculate the spectra of fast neutrons and gamma-rays emitted from the buried objects when neutrons of different energies are used. Calculations were performed using a Monte Carlo Code MCNP IV or GEANT. This code was also used to assess the thermal neutron flux backscattered from plain soil and soil embedded with landmines with different amount of explosive material and buried in the ground at different depths. The measured and calculated results are presented in the form of displayed spectra for gamma-rays and thermal neutron fluxes for landmines buried at different depth in the ground. The analyses of the obtained data can be used to show the strength and weakness of the applied methods for landmine detection in different environmental conditions. (author)

  8. Current and future activities of the Observatoire de Haute Provence in Education and Public Outreach

    Boër, M.; Ducerf, D.

    The Haute Provence Observatory OHP is an observation station located 100km North of Marseille France It performs both astronomical observations and routine atmospheric measurements in the NDSC Network for Data on Stratospheric Changes and several other geophysics national and international networks The site offers also a program directed to the general public the teachers the pupils and the students at all levels In the past two years we reinforced these activities following few guidelines enhance the scientific diffusion activities towards the general public by presenting an exhibition a stronger program for the teachers and the implementation of a project oriented program for the high school and university students We participate also to a curriculum for planetarium attendants We are currently defining the general long term plan for the observatory including a strong EPO program taking advantages of the site visitors facilities guesthouse research group EPO personnel This program will be oriented to the general space and planetary sciences and is prepared in cooperation with both the academic and regional authorities

  9. Purification of Active Myrosinase from Plants by Aqueous Two-Phase Counter-Current Chromatography

    Wade, Kristina L.; Ito, Yoichiro; Ramarathnam, Aarthi; Holtzclaw, W. David; Fahey, Jed W.

    2014-01-01

    Introduction Myrosinase (thioglucoside glucohydrolase; E.C. 3.2.1.147), is a plant enzyme of increasing interest and importance to the biomedical community. Myrosinase catalyses the formation of isothiocyanates such as sulforaphane (frombroccoli) and 4-(α-l-rhamnopyranosyloxy)benzyl isothiocyanate (from moringa), which are potent inducers of the cytoprotective phase-2 response in humans, by hydrolysis of their abundant glucosinolate (β-thioglucoside N-hydroxysulphate) precursors. Objective To develop an aqueous two-phase counter-current chromatography (CCC) system for the rapid, three-step purification of catalytically active myrosinase. Methods A high-concentration potassium phosphate and polyethylene glycol biphasic aqueous two-phase system (ATPS) is used with a newly developed CCC configuration that utilises spiral-wound, flat-twisted tubing (with an ovoid cross-section). Results Making the initial crude plant extract directly in the ATPS and injecting only the lower phase permitted highly selective partitioning of the myrosinase complex before a short chromatography on a spiral disk CCC. Optimum phase retention and separation of myrosinase from other plant proteins afforded a 60-fold purification. Conclusion Catalytically active myrosinase is purified from 3-day broccoli sprouts, 7-day daikon sprouts, mustard seeds and the leaves of field-grown moringa trees, in a CCC system that is predictably scalable. PMID:25130502

  10. Logarithmic InGaAs detectors with global shutter and active dark current reduction

    Ni, Yang; Arion, Bogdan; Bouvier, Christian; Noguier, Vincent

    2015-05-01

    In this paper, we present newly developed logarithmic InGaAs detectors with global shuttering and also an active dark current reduction technique to ensure ambient temperature operation without TEC for industrial applications. The newly released detectors come with both VGA (15um pitch) and QVGA (25um pitch) resolutions, giving the possibility to use lens less than 1-inch size. The logarithmic response is obtained by using solar-cell mode InGaAs photodiodes. The VGA and QVGA ROICs have 3 analog memories inside each pixel which permit, except the classic ITR, IWR and CDS modes, a new differential imaging mode which can be a useful feature in active imaging systems. The photodiode frontend circuit, in pure voltage mode, is made with non-inverting amplifier instead of CTIA. The reason of this choice is that the exposure time can be shortened without need of excessive power consumption as in CTIA front-end. We think that this arrangement associated with true CDS could match the noise performance of CTIA based one. VGA and QVGA ROICs have been designed and manufactured by using 0.18um 1P4M CMOS process. Both ROIC have been tested with success and match the design targets. The first batch of both detectors is under fabrication and will be presented during the conference.

  11. Pharmacological profile of the ATP-mediated increase in L-type calcium current amplitude and activation of a non-specific cationic current in rat ventricular cells.

    Scamps, F.; Vassort, G

    1994-01-01

    1. The pharmacological profile of the ATP-induced increase in ICa amplitude and of ATP activation of a non-specific cationic current, IATP, was investigated in rat ventricular cells. 2. The EC50 values for ICa increase and IATP activation were 0.36 microM and 0.76 microM respectively. Suramin (10 microM) and cibacron blue (1 microM) competitively antagonized both effects of ATP. 3. The rank order of efficacy and potency of ATP analogues in increasing ICa amplitude was 2-methylthio-ATP approxi...

  12. Lithium ions in nanomolar concentration modulate glycine-activated chloride current in rat hippocampal neurons.

    Solntseva, E I; Bukanova, J V; Kondratenko, R V; Skrebitsky, V G

    2016-03-01

    Lithium salts are successfully used to treat bipolar disorder. At the same time, according to recent data lithium may be considered as a candidate medication for the treatment of neurodegenerative disorders. The mechanisms of therapeutic action of lithium have not been fully elucidated. In particular, in the literature there are no data on the effect of lithium on the glycine receptors. In the present study we investigated the effect of Li(+) on glycine-activated chloride current (IGly) in rat isolated pyramidal hippocampal neurons using patch-clamp technique. The effects of Li(+) were studied with two glycine concentrations: 100 μM (EC50) and 500 μM (nearly saturating). Li(+) was applied to the cell in two ways: first, by 600 ms co-application with glycine through micropipette (short application), and, second, by addition to an extracellular perfusate for 10 min (longer application). Li(+) was used in the range of concentrations of 1 nM-1 mM. Short application of Li(+) caused two effects: (1) an acceleration of desensitization (a decrease in the time of half-decay, or "τ") of IGly induced by both 100 μM and 500 μM glycine, and (2) a reduction of the peak amplitude of the IGly, induced by 100 μM, but not by 500 μM glycine. Both effects were not voltage-dependent. Dose-response curves for both effects were N-shaped with two maximums at 100 nM and 1 mM of Li(+) and a minimum at 1 μM of Li(+). This complex form of dose-response may indicate that the process activated by high concentrations of lithium inhibits the process that is sensitive to low concentrations of lithium. Longer application of Li(+)caused similar effects, but in this case 1 μM lithium was effective and the dose-effect curves were not N-shaped. The inhibitory effect of lithium ions on glycine-activated current suggests that lithium in low concentrations is able to modulate tonic inhibition in the hippocampus. This important property of lithium should be considered when using this drug as a

  13. Optimum testing of multiple hypotheses in quantum detection theory

    Yuen, H. P.; Kennedy, R. S.; Lax, M.

    1975-01-01

    The problem of specifying the optimum quantum detector in multiple hypotheses testing is considered for application to optical communications. The quantum digital detection problem is formulated as a linear programming problem on an infinite-dimensional space. A necessary and sufficient condition is derived by the application of a general duality theorem specifying the optimum detector in terms of a set of linear operator equations and inequalities. Existence of the optimum quantum detector is also established. The optimality of commuting detection operators is discussed in some examples. The structure and performance of the optimal receiver are derived for the quantum detection of narrow-band coherent orthogonal and simplex signals. It is shown that modal photon counting is asymptotically optimum in the limit of a large signaling alphabet and that the capacity goes to infinity in the absence of a bandwidth limitation.

  14. Testing composite parametrical hypotheses without applying the reduction

    Vlasov, V.; Vlasova, S.; Tolokonsky, A.

    2016-01-01

    Usually when the parametrical hypotheses are being tested the Wald reduction from composite hypothesis to the simple one is used. However, in order to apply the reduction method it is needed to know the distribution law of unknown parameter. Practically such a law cannot be determined precisely using the experimental data. First of all, it requires long supervision over the controlled stationary process to provide an inalterability of probability characteristics of the process. In practice the modifications in technological process could be made, and therefore the probability characteristics of the process can also change. Using the example of exponential distribution the algorithm of testing composite parametrical hypothesis about the distribution parameter which does not exceed the declared threshold value without use of reduction is considered in article. Such approach is based on the fact that the partition boundary of the sample space depends monotonously on unknown value of the interest parameter.

  15. Minimal hypotheses for particle definition in curved space-time

    In the interaction of a quantum field with a classical gravitational field, it is asked if it is possible to interpret quantum states in terms of particles, and if so, how the properties of the plane waves would be generalized to curved space-time. The Quantum Equivalance Principle, which ascribes a different particle definition to each different spatial hypersurface, is discussed. If specified symmetries hold over space-time it can be expected that the functions G1 x0 (x,x') verifying the above hypothesis were the same over a certain kind of hypersurface. A global momentum space can then be associated with those surfaces and a particle model will then exist. This model is constructed in a flat expanding universe and is then compared to other models in the literature. The hypotheses lead to DeWitt's kernel

  16. Telocytes and Their Extracellular Vesicles—Evidence and Hypotheses

    Cretoiu, Dragos; Xu, Jiahong; Xiao, Junjie; Cretoiu, Sanda M.

    2016-01-01

    Entering the new millennium, nobody believed that there was the possibility of discovering a new cellular type. Nevertheless, telocytes (TCs) were described as a novel kind of interstitial cell. Ubiquitously distributed in the extracellular matrix of any tissue, TCs are regarded as cells with telopodes involved in intercellular communication by direct homo- and heterocellular junctions or by extracellular vesicle (EVs) release. Their discovery has aroused the interest of many research groups worldwide, and many researchers regard them as potentially regenerative cells. Given the experience of our laboratory, where these cells were first described, we review the evidence supporting the fact that TCs release EVs, and discuss alternative hypotheses about their future implications. PMID:27529228

  17. Political Participation Online: The Replacement and the Mobilisation Hypotheses Revisited

    Jensen, Jakob Linaa

    2013-01-01

    This article discusses the state of political participation online more than ten years after the Internet’s great popular breakthrough as an everyday medium. Denmark is used as a case study to critically re-examine the frequently discussed replacement and mobilisation hypotheses on behalf of the ...... participation, efficacy and social capital seem to have less impact on online political participation. In the end, these findings are related to more overall discussions on the democratising potential of the Internet....... Internet. The pure replacement hypothesis is rejected. Instead, it is found that the Internet still supplements rather than replaces other media, even among heavy Internet users. The Internet is one among several media used by ‘media omnivores’, and political participation online supplements rather than...

  18. About hypotheses and paradigms: exploring the Discreetness-Chance Paradigm.

    Kaellis, Eugene

    2006-01-01

    Hypotheses generally conform to paradigms which, over time, change, usually tardily, after they have become increasingly difficult to sustain under the impact of non-conforming evidence and alternative hypotheses, but more important, when they no longer are comfortably ensconced in the surrounding social-economic-political-cultural milieu. It is asserted that this milieu is the most important factor in shaping scientific theorizing. Some examples are cited: the rejection of the evidence that the world orbits around the sun (suspected by Pythagoras) in favor of centuries-long firm adherence to the Ptolemaic geocentric system; the early acceptance of Natural Selection in spite of its tautological essence and only conjectural supporting evidence, because it justified contemporaneous social-political ideologies as typified by, e.g., Spencer and Malthus. Economic, social, and cultural factors are cited as providing the ground, i.e., ideational substrate, for what is cited as the Discreetness-Chance Paradigm (DCP), that has increasingly dominated physics, biology, and medicine for over a century and which invokes small, discrete packets of energy/matter (quanta, genes, microorganisms, aberrant cells) functioning within an environment of statistical, not determined, causality. There is speculation on a possible paradigmatic shift from the DCP, which has fostered the proliferation, parallel with ("splitting") taxonomy, of alleged individual disease entities, their diagnoses, and, when available, their specific remedies, something particularly prominent in, e.g., psychiatry's Diagnostic and Statistical Manual, a codified compendium of alleged mental and behavioral disorders, but evident in any textbook of diagnosis and treatment of physical ailments. This presumed paradigm shift may be reflected in Western medicine, presently increasingly empirical and atomized, towards a growing acceptance of a more generalized, subject-oriented, approach to health and disease, a non

  19. Hypotheses about geoglyphs at Nasca, Peru: new discoveries

    Jaroslav Klokočník

    2016-07-01

    Full Text Available The known hypotheses about the reasons why the geoglyphs in the Nasca and Palpa region of Peru were created are many: roads/paths, rituals/ceremonials, use of hallucinogens, astronomical meaning, influence of extraterrestrials, underground water… and so on. We present a new hypothesis, formulated by J. Sonnek (first published in 2011 in the context of all previous hypotheses.1 Sonnek explains the geoglyphs as tidied work areas for the production of rope and nets, although he goes much further than Stierlin. This eccentric hypothesis now has not only experimental but also archaeological and ethnographical support, which is presented here. Geoglyphs of a special shape were discovered in the pampas; they may represent technical objects – different types of ‘rope twisters’. Following this idea, Sonnek made technical devices (using today’s materials and tested them in practice; they work perfectly, see his YouTube videos.2 In November 2012, wooden pieces, which may be the remnants of ropemaking, were collected from the pampa near the towns of Nasca and Palpa, in vicinity of these hypothetic ropemaking places. Radiocarbon testing by 14C standardized radio-carbon age according to Stuiver-Polach convention and Accelerator Mass Spectroscopy (AMS of these wood pieces shows the age to be in a wide range from Early Nasca to the 17th century (and to our epoch with a fake geoglyph, too, thus supporting (but surely not proving the new hypothesis. Moreover, in the Quechua language, the word huasca, waskha (read: uasca means a rope or cord or place where these are produced. This word is very similar to ‘nasca’.

  20. The use of extremal hypotheses as a means of predicting alluvial channel dimensions for river restoration

    Tranmer, A.; Goodwin, P.

    2013-12-01

    In designing fluvial infrastructure and restoration projects the question often arises, what are the cross sectional characteristics of width, depth, roughness, and slope necessary to ensure no net aggradation or degradation occurs within a given reach of river? Current fluvial design utilizes empirical and numerical methods to calculate the required slope and geometry of alluvial channels; however, no solution has been proposed that fully incorporates the necessary 3-dimensional mechanics of open channels due to the complicated processes and feedbacks that occur during mobile bed conditions. This is further compounded by numerous local geologic constraints and perturbations that must be considered, which interrupt the evolution towards a balance of deposition and erosion, or the condition of dynamic-equilibrium. However, given the moderate success of power law relations, such as regime theory and hydraulic geometry, it is evident self-organizing processes are present in watersheds that scale channel size and sinuosity to some average condition in order to maintain a balance of fluid and sediment flux from the upstream catchment. Extremal hypotheses have been developed as an alternative to solving the reach scale 3-dimensional conservation laws for fluid and sediment, to provide a first order means of predicting channel dimensions in an objective and reproducible manner. This study evaluates the performance of extremal hypotheses in identifying the trend towards dynamic-equilibrium over unique spatial gradients in 2 gravel-bed river systems. Using a location-for-time-substitution approach, extremal hypotheses were examined over a longitudinal gradient of channel evolution towards reaches found to be near equilibrium in an unconfined, transport-limited river in the undisturbed rain forest of Chilean Patagonia and a supply-limited, semi-confined canyon system in Central Idaho, USA. Field data from these two sites imply alluvial systems attempt to minimize their

  1. Eruptive history, current activity and risk estimation using geospatial information in the Colima volcano, Mexico

    Suarez-Plascencia, C.; Camarena-Garcia, M.; Nunez-Cornu, F. J.; Flores-Peña, S.

    2013-12-01

    avocado orchards and fruits like blueberries, raspberries, and blackberries within the radius of 15 km from the crater. The population dynamics in the Colima volcano area had a population of 552,954 inhabitants in 2010, and a growth at an annual rate of 1.6 percent of the total population. 60 percent of the populations live in 105 towns with a population less than 250 inhabitants. Also, the region showed an increase in vulnerability for the development of economic activities, supported by the highway, railway, natural gas pipelines and electrical infrastructure that connect to the Port of Manzanillo to Guadalajara city. With the use of geospatial information quantify the vulnerability, together with the hazard maps and exposure, enabled us to build the following volcanic risk maps: a) Exclusion areas and moderate hazard for explosive events (ballistic) and pyroclastic flows, b) Hazard map of lahars and debris flow, and c) Hazard map of ash-fall. The geospatial database, a GIS mapping and current volcano monitoring, are the basis of the Operational Plan Colima Volcano. Civil Protection by the state of Jalisco and the updating of urban development plans of municipalities converge on the volcano. These instruments of land planning will help reduce volcanic risk in the region.

  2. Stress-Activated Electric Currents in the Earth Crust: How they Can and Cannot Flow (Invited)

    Freund, F. T.; Bleier, T. E.; Bortnik, J.; Dahlgren, R.

    2010-12-01

    Dormant electronic charge carriers exist in rocks. They “wake up” when stresses are applied: electrons e’ and positive holes, h., the latter being defect electrons in the oxygen anion sublattice of minerals [1, 2]. The h. can flow out of the stressed subvolume. They can spread into the unstressed surrounding, turning the rocks into p-type semiconductors. They travel fast and far using energy levels at the upper edge of the valence bands. Contrary to the h., the co-activated electrons e’ cannot flow out and propagate through unstressed rocks: they are stuck in the activation volume. The situation is akin to that in an electrochemical battery except that, in the “rock battery”, the positive charge carriers are not cations but positive holes h.. In the laboratory it is easy to close the battery circuit by offering the electrons a metal contact and connecting the stressed and unstressed rock with a metal wire. This is useful to demonstrate the functioning of the “rock battery”. In the field the h. outflow from a stressed rock volume is restricted as long as there is no return path. This is an important point when we try to understand why pre-earthquake EM emission is widely considered “unreliable” [3, 4]. However, there are at least three conditions, under which circuit closure can be achieved in the field under realistic pre-earthquake situations: (i) via n-type conducting rocks; (ii) via electrolytic conductivity of water; and (iii) via the air when the air above the epicentral region becomes highly ionized. We report on examples where these three conditions might have allowed large currents to flow and strong EM signals to be emitted. [1] Freund, F.T. et al.: Electric currents streaming out of stressed igneous rocks - A step towards understanding pre-earthquake low frequency EM emissions, Phys. Chem. Earth 31, 389-396 (2006). [2] Freund, F.T.: Charge generation and propagation in rocks, J. Geodyn. 33, 545-572 (2002). [3] Johnston, M.J.S. and

  3. Certainties, doubts and hypotheses in porcine reproductive and respiratory syndrome virus immunobiology.

    Darwich, Laila; Díaz, Ivan; Mateu, Enric

    2010-12-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most costly pathogens for the swine industry. Since its emergence some 20 years ago, much has been learned about the immunobiology of PRRSV. Although vaccines are available, they do not provide full and universal protection against PRRSV infection. In the present review, current knowledge on the virus's immunobiology will be discussed including: role of viral receptors, innate immune response to the virus, regulation of the immune response by PRRSV, and the characteristics and role of adaptive immunity. In addition, some hypotheses for future research in this area are presented. PMID:20659507

  4. Transcranial Direct Current Stimulation Modulates Neuronal Activity and Learning in Pilot Training.

    Choe, Jaehoon; Coffman, Brian A; Bergstedt, Dylan T; Ziegler, Matthias D; Phillips, Matthew E

    2016-01-01

    Skill acquisition requires distributed learning both within (online) and across (offline) days to consolidate experiences into newly learned abilities. In particular, piloting an aircraft requires skills developed from extensive training and practice. Here, we tested the hypothesis that transcranial direct current stimulation (tDCS) can modulate neuronal function to improve skill learning and performance during flight simulator training of aircraft landing procedures. Thirty-two right-handed participants consented to participate in four consecutive daily sessions of flight simulation training and received sham or anodal high-definition-tDCS to the right dorsolateral prefrontal cortex (DLPFC) or left motor cortex (M1) in a randomized, double-blind experiment. Continuous electroencephalography (EEG) and functional near infrared spectroscopy (fNIRS) were collected during flight simulation, n-back working memory, and resting-state assessments. tDCS of the right DLPFC increased midline-frontal theta-band activity in flight and n-back working memory training, confirming tDCS-related modulation of brain processes involved in executive function. This modulation corresponded to a significantly different online and offline learning rates for working memory accuracy and decreased inter-subject behavioral variability in flight and n-back tasks in the DLPFC stimulation group. Additionally, tDCS of left M1 increased parietal alpha power during flight tasks and tDCS to the right DLPFC increased midline frontal theta-band power during n-back and flight tasks. These results demonstrate a modulation of group variance in skill acquisition through an increasing in learned skill consistency in cognitive and real-world tasks with tDCS. Further, tDCS performance improvements corresponded to changes in electrophysiological and blood-oxygenation activity of the DLPFC and motor cortices, providing a stronger link between modulated neuronal function and behavior. PMID:26903841

  5. An automated framework for hypotheses generation using literature

    Abedi Vida

    2012-08-01

    Full Text Available Abstract Background In bio-medicine, exploratory studies and hypothesis generation often begin with researching existing literature to identify a set of factors and their association with diseases, phenotypes, or biological processes. Many scientists are overwhelmed by the sheer volume of literature on a disease when they plan to generate a new hypothesis or study a biological phenomenon. The situation is even worse for junior investigators who often find it difficult to formulate new hypotheses or, more importantly, corroborate if their hypothesis is consistent with existing literature. It is a daunting task to be abreast with so much being published and also remember all combinations of direct and indirect associations. Fortunately there is a growing trend of using literature mining and knowledge discovery tools in biomedical research. However, there is still a large gap between the huge amount of effort and resources invested in disease research and the little effort in harvesting the published knowledge. The proposed hypothesis generation framework (HGF finds “crisp semantic associations” among entities of interest - that is a step towards bridging such gaps. Methodology The proposed HGF shares similar end goals like the SWAN but are more holistic in nature and was designed and implemented using scalable and efficient computational models of disease-disease interaction. The integration of mapping ontologies with latent semantic analysis is critical in capturing domain specific direct and indirect “crisp” associations, and making assertions about entities (such as disease X is associated with a set of factors Z. Results Pilot studies were performed using two diseases. A comparative analysis of the computed “associations” and “assertions” with curated expert knowledge was performed to validate the results. It was observed that the HGF is able to capture “crisp” direct and indirect associations, and provide knowledge

  6. Landscape moderation of biodiversity patterns and processes - eight hypotheses.

    Tscharntke, Teja; Tylianakis, Jason M; Rand, Tatyana A; Didham, Raphael K; Fahrig, Lenore; Batáry, Péter; Bengtsson, Janne; Clough, Yann; Crist, Thomas O; Dormann, Carsten F; Ewers, Robert M; Fründ, Jochen; Holt, Robert D; Holzschuh, Andrea; Klein, Alexandra M; Kleijn, David; Kremen, Claire; Landis, Doug A; Laurance, William; Lindenmayer, David; Scherber, Christoph; Sodhi, Navjot; Steffan-Dewenter, Ingolf; Thies, Carsten; van der Putten, Wim H; Westphal, Catrin

    2012-08-01

    Understanding how landscape characteristics affect biodiversity patterns and ecological processes at local and landscape scales is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest eight hypotheses, which we hope will encourage more systematic research on the role of landscape composition and configuration in determining the structure of ecological communities, ecosystem functioning and services. We organize the eight hypotheses under four overarching themes. Section A: 'landscape moderation of biodiversity patterns' includes (1) the landscape species pool hypothesis-the size of the landscape-wide species pool moderates local (alpha) biodiversity, and (2) the dominance of beta diversity hypothesis-landscape-moderated dissimilarity of local communities determines landscape-wide biodiversity and overrides negative local effects of habitat fragmentation on biodiversity. Section B: 'landscape moderation of population dynamics' includes (3) the cross-habitat spillover hypothesis-landscape-moderated spillover of energy, resources and organisms across habitats, including between managed and natural ecosystems, influences landscape-wide community structure and associated processes and (4) the landscape-moderated concentration and dilution hypothesis-spatial and temporal changes in landscape composition can cause transient concentration or dilution of populations with functional consequences. Section C: 'landscape moderation of functional trait selection' includes (5) the landscape-moderated functional trait selection hypothesis-landscape moderation of species trait selection shapes the functional role and trajectory of community assembly, and (6) the landscape-moderated insurance hypothesis-landscape complexity provides spatial and temporal insurance, i.e. high resilience and stability of ecological processes in changing environments. Section D: 'landscape constraints on

  7. 76 FR 31342 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    2011-05-31

    ... in the Federal Register of September 29, 1978 (43 FR 45014), and are now an integral and familiar... Collection; Comment Request; Current Good Manufacturing Practice Regulations for Finished Pharmaceuticals... Current Good Manufacturing Practice (CGMP) Regulations for Finished Pharmaceuticals. DATES: Submit...

  8. Control of plasma properties in a short direct-current glow discharge with active boundaries

    Adams, S. F. [Air Force Research Laboratory, WPAFB, Ohio 45433 (United States); Demidov, V. I., E-mail: vladimir.demidov@mail.wvu.edu [Air Force Research Laboratory, WPAFB, Ohio 45433 (United States); West Virginia University, Morgantown, West Virginia 26506 (United States); Bogdanov, E. A.; Kudryavtsev, A. A. [St. Petersburg State University, St. Petersburg 199034 (Russian Federation); Koepke, M. E. [West Virginia University, Morgantown, West Virginia 26506 (United States); Kurlyandskaya, I. P. [St. Petersburg University of State Fire Service of EMERCOM RF, Murmansk Branch, Murmansk 183040 (Russian Federation)

    2016-02-15

    To demonstrate controlling electron/metastable density ratio and electron temperature by applying negative voltages to the active (conducting) discharge wall in a low-pressure plasma with nonlocal electron energy distribution function, modeling has been performed in a short (lacking the positive-column region) direct-current glow discharge with a cold cathode. The applied negative voltage can modify the trapping of the low-energy part of the energetic electrons that are emitted from the cathode sheath and that arise from the atomic and molecular processes in the plasma within the device volume. These electrons are responsible for heating the slow, thermal electrons, while production of slow electrons (ions) and metastable atoms is mostly due to the energetic electrons with higher energies. Increasing electron temperature results in increasing decay rate of slow, thermal electrons (ions), while decay rate of metastable atoms and production rates of slow electrons (ions) and metastable atoms practically are unchanged. The result is in the variation of electron/metastable density ratio and electron temperature with the variation of the wall negative voltage.

  9. Noninvasive reconstruction of cardiac electrical activity: update on current methods, applications and challenges.

    Cluitmans, M J M; Peeters, R L M; Westra, R L; Volders, P G A

    2015-06-01

    Electrical activity at the level of the heart muscle can be noninvasively reconstructed from body-surface electrocardiograms (ECGs) and patient-specific torso-heart geometry. This modality, coined electrocardiographic imaging, could fill the gap between the noninvasive (low-resolution) 12-lead ECG and invasive (high-resolution) electrophysiology studies. Much progress has been made to establish electrocardiographic imaging, and clinical studies appear with increasing frequency. However, many assumptions and model choices are involved in its execution, and only limited validation has been performed. In this article, we will discuss the technical details, clinical applications and current limitations of commonly used methods in electrocardiographic imaging. It is important for clinicians to realise the influence of certain assumptions and model choices for correct and careful interpretation of the results. This, in combination with more extensive validation, will allow for exploitation of the full potential of noninvasive electrocardiographic imaging as a powerful clinical tool to expedite diagnosis, guide therapy and improve risk stratification. PMID:25896779

  10. Current activities in support of CANDU plant life management: an industry perspective

    The current focus of the CANDU industry is to position the nuclear option as a cost competitive, safe and reliable means of electricity production. To achieve its goal the CANDU industry as a whole is undertaking steps to improve further its performance and safety of its nuclear power plants. A number of programs have been planned and implemented particularly for plants in the mid-life range. Some of these programs include life assessment studies of critical systems, Structures and Components (SSCS), refurbishment and upgrading programs and monitoring and periodic inspection programs. Some elements of the programs have been in place from station start up and some are being instituted as part of the aging management and performance improvement program. The industry recognizes that the key to sustaining high performance over the life of the plant is the implementation of an integrated aging management program that encompasses all elements of plant operation and maintenance. A systematically implemented program on optimized maintenance and inspection strategy, standardized work processes, component rehabilitation programs, and applying lessons learned are some of the elements of a sustainable high performance and an effective plant life assurance program. The paper will describe the elements of an integrated program, the multiphase approach defined for CANDU PLIM and some of the activities undertaken by the industry to further improve and sustain plant safety, reliability and performance. (author)

  11. The IAEA international project on innovative nuclear reactors and fuel cycles (INPRO): current and future activities

    Upon resolutions of the IAEA General Conference in 2000, the IAEA initiated International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO). The objective of INPRO, which comprises two phases, is to support sustainable deployment and use of nuclear technology to meet the global energy needs in the next 50 years and beyond. During Phase I, work is subdivided into two sub phases. Phase 1A focused on determining user requirements in the areas of economics, environment, safety, proliferation resistance, and recommendations in the area of so-called crosscutting issues, which are legal, institutional, and infrastructure issues accompanying the deployment of nuclear power, and is targeted at developing a methodology and guidelines for the assessment of various nuclear reactor and fuel cycle concepts and approaches. Phase 1A was finalised in June 2003 with its results now available as IAEA TECDOC-1362. Phase 1B has started in July 2003. During this phase interested Member States are performing case studies to validate the INPRO methodology and, later on, to assess selected innovative nuclear energy systems using the updated INPRO methodology. In accordance with the INPRO Terms of Reference, after successful completion of Phase I, Phase II may be initiated to examine the feasibility of commencing international projects on innovative nuclear energy systems. The paper contains a description of the current and future activities of INPRO and summarizes the outcome of the project.(author)

  12. Modeling body size evolution in Felidae under alternative phylogenetic hypotheses

    José Alexandre Felizola Diniz-Filho

    2009-01-01

    Full Text Available The use of phylogenetic comparative methods in ecological research has advanced during the last twenty years, mainly due to accurate phylogenetic reconstructions based on molecular data and computational and statistical advances. We used phylogenetic correlograms and phylogenetic eigenvector regression (PVR to model body size evolution in 35 worldwide Felidae (Mammalia, Carnivora species using two alternative phylogenies and published body size data. The purpose was not to contrast the phylogenetic hypotheses but to evaluate how analyses of body size evolution patterns can be affected by the phylogeny used for comparative analyses (CA. Both phylogenies produced a strong phylogenetic pattern, with closely related species having similar body sizes and the similarity decreasing with increasing distances in time. The PVR explained 65% to 67% of body size variation and all Moran's I values for the PVR residuals were non-significant, indicating that both these models explained phylogenetic structures in trait variation. Even though our results did not suggest that any phylogeny can be used for CA with the same power, or that “good” phylogenies are unnecessary for the correct interpretation of the evolutionary dynamics of ecological, biogeographical, physiological or behavioral patterns, it does suggest that developments in CA can, and indeed should, proceed without waiting for perfect and fully resolved phylogenies.

  13. Exploration of miRNA families for hypotheses generation.

    Kamanu, T.K.

    2013-10-15

    Technological improvements have resulted in increased discovery of new microRNAs (miRNAs) and refinement and enrichment of existing miRNA families. miRNA families are important because they suggest a common sequence or structure configuration in sets of genes that hint to a shared function. Exploratory tools to enhance investigation of characteristics of miRNA families and the functions of family-specific miRNA genes are lacking. We have developed, miRNAVISA, a user-friendly web-based tool that allows customized interrogation and comparisons of miRNA families for hypotheses generation, and comparison of per-species chromosomal distribution of miRNA genes in different families. This study illustrates hypothesis generation using miRNAVISA in seven species. Our results unveil a subclass of miRNAs that may be regulated by genomic imprinting, and also suggest that some miRNA families may be species-specific, as well as chromosome- and/or strand-specific.

  14. Testing vs. Believing Hypotheses: Magical Ideation in the Judgement of Contingencies.

    Brugger, P; Graves, R E

    1997-11-01

    This paper examines the idea that an important dimension of human cognition is the amount of objective evidence required for perception of meaningful patterns. At the clinical extreme of this dimension are patients with hallucinations and delusions who experience perception with no external evidence and see connections between objectively unrelated events. Also, normal individuals exhibit considerable variation along this continuum. The theory proposed here predicts that normal subjects with low evidential criteria will be more likely to accept causal explanations, not only for everyday ''paranormal'' coincidences, but also for random contingencies in a laboratory experiment. This prediction was confirmed when 40 students completed a differential reinforcement of low rates (DRL) task designed to induce superstitious behaviour and were then questioned about their hypotheses concerning the contingencies for successful performance. Participants scoring high on the Magical Ideation scale (indicating greater belief in paranormal phenomena) tested fewer hypotheses during the task, and they ended up believing in more hypotheses regarding illusory contingencies than did their low-scoring peers. We proposed that a continuum of hypothesis-testing behaviour underlies the schizotypy continuum, with ''positive'' schizotypal traits reflecting a Type I error bias and ''negative'' traits a Type II error bias. Differential activation patterns within frontal-limbic networks are tentatively suggested as a physiological correlate of the behavioural continuum. PMID:25419793

  15. Capacities and current activities of the Cyclotron and Nuclear Medicine Department of NRCAM

    Full text: The Cyclotron and Nuclear Medicine Department at the Nuclear Research Center for Agriculture and Medicine (NRCAM) has a cyclotron accelerator - model Cyclone 30 - which is a fixed frequency, dual beam extraction system with capabilities to produce proton beam in 15-30 MeV range of energy and deuteron beam in 7-15 MeV range of energy, with maximum output current of 500 μA and 150 μA, respectively. This Department consists of some laboratories and sections, such as: electro-chemical lab., inorganic-chemistry lab., labeling lab., radioisotopes production hot labs, quality control section, nuclear medicine section, etc. According to these facilities, this Department is capable to produce various radioisotopes and radiopharmaceuticals, with high quality and quantity in accordance to the international standards, which are widely used in nuclear medicine, such as 201Tl, 67Ga, 81mKr, 111In, 18FDG, 123I, 103Pd, 57Co. From these radioisotopes and radiopharmaceuticals the 201Tl, 67Ga, 81mKr are routinely produced and sent weekly to about 35 hospitals and nuclear medicine centers around the country. In order to achieve the knowledge of the routine production of 103Pd and 57Co radioisotopes, a technical cooperation (TC) project was defined under the support of the IAEA (IRA/04/032). There are also some new TC projects being proposed and to be submitted to the IAEA for support, e.g. proposed TC projects on 'Production of 123I through a new technique of bombarding the 123Te isotope with proton', and on 'Achieving the knowledge of producing the seed form of 103Pd for brachytherapy'. With regard to international safety principles, radiation protection and environmental protection rules, the Department aims to choose the quality management standard system ISO 9001-2000 for its radiopharmaceutical production. In this article we are going to introduce the Cyclotron and Nuclear Medicine Department at NRCAM, its facilities, current activities and future goals as well as

  16. Frontier Science in the Polar Regions: Current Activities of the Polar Research Board

    Brown, L. M.

    2011-12-01

    The National Academies (the umbrella term for the National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council) is a private, nonprofit organization chartered by Congress in 1863. The Polar Research Board (PRB) is the focal point within the Academies for providing advice on issues related to the Arctic, Antarctic, and cold regions in general. Tasks within the PRB mission include: providing a forum for the polar science community to address research needs and policy issues; conducting studies and workshops on emerging scientific and policy issues in response to requests from federal agencies and others; providing program reviews, guidance, and assessments of priorities; and facilitating communication on polar issues among academia, industry, and government. The PRB also serves as the US National Committee to two international, nongovernmental polar science organizations: the Scientific Committee on Antarctic Research (SCAR) and the International Arctic Science Committee (IASC). The polar regions are experiencing rapid changes in environment and climate, and the PRB has a number of completed and ongoing studies that will enhance scientific understanding of these issues. This poster will illustrate current PRB activities as well as results from two recently released reports: Frontiers in Understanding Climate Change and Polar Ecosystems and Future Science Opportunities in Antarctica and the Southern Ocean. In the former, a set of frontier research questions are developed to help scientists understand the impacts of climate change on polar ecosystems. The report builds on existing knowledge of climate change impacts and highlights the next big topics to be addressed in the coming decades. In addition, a number of methods and technologies are identified that will be useful to advance future research in polar ecosystem science. In the latter, changes to important science conducted on Antarctica and the surrounding

  17. The current uranium exploration activities of the Power Reactor and Nuclear Fuel Development Corporation (PNC), Japan

    As of November 1996, Japan's total installed commercial nuclear power generation capacity was 42 GW(e), accounting for 34% of total electric energy generation. By 2010, Japan intends to have an installed electricity generation capacity of 70.5 GW(e). This will increase the country's demand for nat Ural uranium from 7,700 t U in 1994 (13% of the world consumption) to 13,800 t U in 2010 (17%-19% of the world projected consumption). However, Japan's known uranium resources at Ningyo-Toge and Tono deposits, are estimated at roughly only 6,600 t U. The Long-term Programme for Research, Development and Utilization of Nuclear Energy (adopted in 1994) calls for diversification through long-term purchasing contracts, independent exploration and involvement in mining vent Ures, with the objective of ensuring independence and stability in Japan's development and utilization of nuclear energy. The Power Reactor and Nuclear Fuel Development Corporation (PNC) has been commissioned to carry out the task of independent exploration. PNC is carrying out exploration projects in Canada, Australia, USA and China targeting unconformity related type deposits with an eye to privatizing them. Currently about 40,000 t U of uranium resources are held by PNC. PNC has been carrying out the following related activities: (1) Reference surveys on uranium resources to delineate the promising areas; (2) Development of uranium exploration technology; (3) Information surveys on the nuclear industries to project long-term supply and demand; (4) International Cooperation programme on uranium exploration with Asian countries. (author)

  18. Modeling the forest transition: forest scarcity and ecosystem service hypotheses.

    Satake, Akiko; Rudel, Thomas K

    2007-10-01

    An historical generalization about forest cover change in which rapid deforestation gives way over time to forest restoration is called "the forest transition." Prior research on the forest transition leaves three important questions unanswered: (1) How does forest loss influence an individual landowner's incentives to reforest? (2) How does the forest recovery rate affect the likelihood of forest transition? (3) What happens after the forest transition occurs? The purpose of this paper is to develop a minimum model of the forest transition to answer these questions. We assume that deforestation caused by landowners' decisions and forest regeneration initiated by agricultural abandonment have aggregated effects that characterize entire landscapes. These effects include feedback mechanisms called the "forest scarcity" and "ecosystem service" hypotheses. In the forest scarcity hypothesis, forest losses make forest products scarcer, which increases the economic value of forests. In the ecosystem service hypothesis, the environmental degradation that accompanies the loss of forests causes the value of ecosystem services provided by forests to decline. We examined the impact of each mechanism on the likelihood of forest transition through an investigation of the equilibrium and stability of landscape dynamics. We found that the forest transition occurs only when landowners employ a low rate of future discounting. After the forest transition, regenerated forests are protected in a sustainable way if forests regenerate slowly. When forests regenerate rapidly, the forest scarcity hypothesis expects instability in which cycles of large-scale deforestation followed by forest regeneration repeatedly characterize the landscape. In contrast, the ecosystem service hypothesis predicts a catastrophic shift from a forested to an abandoned landscape when the amount of deforestation exceeds the critical level, which can lead to a resource degrading poverty trap. These findings imply

  19. PreBötzinger complex and pacemaker neurons: hypothesized site and kernel for respiratory rhythm generation

    Rekling, J C; Feldman, J L

    1998-01-01

    , progress has been made In particular, a site in the ventrolateral medulla, the preBötzinger Complex, is hypothesized to contain neuronal circuits generating respiratory rhythm. Lesions or disruption of synaptic transmission within the preBötzinger Complex, either in vivo or in vitro, can abolish...... respiratory activity. Furthermore, the persistence of respiratory rhythm following interference with postsynaptic inhibition and the subsequent discovery of neurons with endogenous bursting properties within the preBötzinger Complex have led to the hypothesis that rhythmogenesis results from synchronized...

  20. Assaults on Inmates and Staff by Perpetrators of Intimate Partner Homicide: An Examination of Competing Hypotheses.

    Sorensen, Jonathan R; Vigen, Mark P; Woods, S O; Williams, Bradley D

    2015-11-01

    The current study presents the results of an analysis of serious and assaultive prison rule violating behavior among male perpetrators of intimate partner homicide (IPH). Data on prison rule violations were collected from a sample of 189 inmates convicted of IPH in a large, southern prison system. The study focused on the degree of continuity in violent behavior among IPH offenders from the community to the prison setting. The current study tested hypotheses derived from both the feminist perspective (FP) and the general violence perspective (GVP). As a group, IPH offenders were better behaved in prison than other incarcerated homicide offenders, thereby offering some support for the FP. However, the lower level of assaultive behavior among the group was not universal. Characteristics associated with continued violent offending in the prison environment were the same as those found in previous studies of incarcerated homicide offenders, thereby lending greater support to the GVP. PMID:25516133

  1. Effects of lanthanum on calcium-activated K~+ currents and its kinetics in MC3T3 cells

    2010-01-01

    Using the whole cell patch-clamp technique,we studied the effects of La3+ on calcium-activated K+ currents and its kinetics of activation and inactivation in non-excitable MC3T3 cells.Our results showed that the calcium-activated outward K+ currents were promoted with increasing concentration of Ca2+ in the pipette solution and a voltage- and Ca2+-dependent manner.La3+ in the bath solution inhibited the currents in a concentration-dependent manner and the inhibition EC50 was 8.23 ± 1.45 μmol/L.At the concentration of 50 μmol/L,La3+ significantly changed the Vh of the activation curve and shifted the activation curve to more positive potentials,but shifted the inactivation curve to more negative potentials.It had no effect on the slope factor k of the activation and inactivation curves.Potassium currents inhibition could induce a series of physiological and molecular biological functions,presumably because of its ability to depolarize the plasma membrane and enhance cell excitability,resulting in increasing Ca2+ influx and cytoplast Ca2+ concentration.This process may be one of the molecular mechanisms by which La3+ affects the cell growth and function of MC3T3 cells.

  2. 76 FR 21407 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Current...

    2011-04-15

    ...; Current Population Survey--Basic Labor Force ACTION: Notice. SUMMARY: The Department of Labor (DOL) is..., ``Current Population Survey--Basic Labor Force,'' to the Office of Management and Budget (OMB) for review..._PRA_PUBLIC@dol.gov . SUPPLEMENTARY INFORMATION: The labor force data collected in the...

  3. A cyclic GMP-dependent calcium-activated chloride current in smooth-muscle cells from rat mesenteric resistance arteries

    Matchkov, Vladimir; Aalkjær, Christian; Nilsson, Holger

    2004-01-01

    We have previously demonstrated the presence of a cyclic GMP (cGMP)-dependent calcium-activated inward current in vascular smooth-muscle cells, and suggested this to be of importance in synchronizing smooth-muscle contraction. Here we demonstrate the characteristics of this current. Using...... conventional patch-clamp technique, whole-cell currents were evoked in freshly isolated smooth-muscle cells from rat mesenteric resistance arteries by elevation of intracellular calcium with either 10 mM caffeine, 1 microM BAY K8644, 0.4 microM ionomycin, or by high calcium concentration (900 nM) in the....... Under conditions of high calcium in the patch-pipette solution, a current similar to the latter could be identified also in the mesenteric artery smooth-muscle cells. We conclude that smooth-muscle cells from rat mesenteric resistance arteries have a novel cGMP-dependent calcium-activated chloride...

  4. The L1=L2 Hypotheses: A Reconsideration

    Ellis, Rod

    1985-01-01

    Discusses the L1=L2 hypothesis which states that, all other things except knowledge of language being equal, first language acquisition is the same as second language acquisition. Reviews the evidence for and against the hypothesis, looks at current research and considers the general distinction between formal and informal learning. (SED)

  5. Comparative Study of two PWM techniques for Three Phase Shunt Hybrid Active Power Filter to Suppress Line Current Harmonics

    SELVAMUTHUKUMARAN Rajasekar; NATARAJAN Muraly; PERIANAYAGAM Ajay-D-VimalRaj; MAHALINGAM Sudhakaran

    2010-01-01

    This paper investigates the performanceand comparison of two pulse-width-modulation (PWM)techniques by employing direct current control strategyapplied to three phase shunt hybrid active power filter(SHAPF). The objective of SHAPF is to eliminate linecurrent harmonics and to incur reactive powercompensation. The direct current control strategy isimplemented using Standard PWM (S-PWM) and aModified PWM (M-WM), in order to compensatecurrent harmonic and reactive power generated bydifferent load...

  6. Active Harmonic Filtering Using Current-Controlled, Grid-Connected DG Units With Closed-Loop Power Control

    Jinwei He,; Yun Wei Li,; Blaabjerg, Frede; Xiongfei Wang,

    2014-01-01

    The increasing application of nonlinear loads may cause distribution system power quality issues. In order to utilize distributed generation (DG) unit interfacing converters to actively compensate harmonics, this paper proposes an enhanced current control approach, which seamlessly integrates system harmonic mitigation capabilities with the primary DG power generation function. As the proposed current controller has two well-decoupled control branches to independently control fundamental and ...

  7. Curie's hypotheses concerning radioactivity and the origin of the elements

    Pierre Curie gave two hypotheses at first; (1) It can be supposed that the radioactive substances borrow the energy, which they release, from an external radiation, and their radiation would then be a secondary radiation, (2) It can be supposed that the radioactive substances draw from themselves the energy which they release. The second hypothesis has shown the more fertile in explaining the properties of the radioactive substances. Consequently, the first hypothesis became more or less forgotten. It appears, however, the first hypothesis should play an important role in explaining the phenomena concerning the origin of the elements. The Oklo Phenomenon has demonstrated that a nuclear fire had once existed on our planet earth and formation of heavy elements was occurring in nature. The author pointed out that the difference in the isotopic compositions of xenon found in meteorites, lunar samples and in the earth's atmosphere can only be explained as due to the alterations of the isotropic compositions of xenon by combined effect of (a) mass-fractionation, (b) spallation, and (c) stellar temperature neutron-capture reactions. The strange xenon components are not isotopically pure substance. Instead, xenon-HL is a mixture of the 244Pu fission xenon and the xenon whose isotopic compositions is severely altered by a combined effect of the processes (a), (b) and (c) mentioned above. These results also indicate that C1 carbonaceous chondrites, which is generally as the most primitive sample of the solar system material, began to retain its xenon 5.1 billion years ago, when the plutonium to uranium ratio in the solar system was as high as almost 0.6 (atom/atom), while the C2 carbonaceous chondrite began to retain their xenon about 150 million years later and the ordinary chondrites and achondrite about 500 to 600 million years later. This means that the birth of the solar system began soon after the last supernova exploded about 5.1 billion years ago, and the generally

  8. Curie's hypotheses concerning radioactivity and the origin of the elements

    Pierre Curie gave two hypotheses at first; (1) It can be supposed that the radioactive substances borrow the energy, which they release, from an external radiation, and their radiation would then be a secondary radiation, (2) It can be supposed that the radioactive substances draw from themselves the energy which they release. The second hypothesis has shown the more fertile in explaining the properties of the radioactive substances. Consequently, the first hypothesis became more or less forgotten. It appears, however, the first hypothesis should play an important role in explaining the phenomena concerning the origin of the elements. The Oklo Phenomenon has demonstrated that a nuclear fire had once existed on our planet earth and formation of heavy elements was occurring in nature. The author pointed out that the difference in the isotopic compositions of xenon found in meteorites, lunar samples and in the earth's atmosphere can only be explained as due to the alterations of the isotropic compositions of xenon by combined effect of (a) mass-fractionation, (b) spallation, and (c) stellar temperature neutron-capture reactions. The strange xenon components are not isotopically pure substance. Instead, xenon-HL is a mixture of the 244Pu fission xenon and the xenon whose isotopic compositions is severely altered by a combined effect of the processes (a), (b) and (c) mentioned above. These results also indicate that C1 carbonaceous chondrites, which is generally as the most primitive sample of the solar system material, began to retain its xenon 5.1 billion years ago, when the plutonium to uranium ratio in the solar system was as high as almost 0.6 (atom/atom), while the C2 carbonaceous chondrite began to retain their xenon about 150 million years later and the ordinary chondrites and achondrite about 500 to 600 million years later. This means that the birth of the solar system began soon after the last supernova exploded about 5.1 billion years ago, and the generally

  9. The Europa Imaging System (EIS): Investigating Europa's geology, ice shell, and current activity

    Turtle, Elizabeth; Thomas, Nicolas; Fletcher, Leigh; Hayes, Alexander; Ernst, Carolyn; Collins, Geoffrey; Hansen, Candice; Kirk, Randolph L.; Nimmo, Francis; McEwen, Alfred; Hurford, Terry; Barr Mlinar, Amy; Quick, Lynnae; Patterson, Wes; Soderblom, Jason

    2016-07-01

    NASA's Europa Mission, planned for launch in 2022, will perform more than 40 flybys of Europa with altitudes at closest approach as low as 25 km. The instrument payload includes the Europa Imaging System (EIS), a camera suite designed to transform our understanding of Europa through global decameter-scale coverage, topographic and color mapping, and unprecedented sub- meter-scale imaging. EIS combines narrow-angle and wide-angle cameras to address these science goals: • Constrain the formation processes of surface features by characterizing endogenic geologic structures, surface units, global cross-cutting relationships, and relationships to Europa's subsurface structure and potential near-surface water. • Search for evidence of recent or current activity, including potential plumes. • Characterize the ice shell by constraining its thickness and correlating surface features with subsurface structures detected by ice penetrating radar. • Characterize scientifically compelling landing sites and hazards by determining the nature of the surface at scales relevant to a potential lander. EIS Narrow-angle Camera (NAC): The NAC, with a 2.3°° x 1.2°° field of view (FOV) and a 10-μμrad instantaneous FOV (IFOV), achieves 0.5-m pixel scale over a 2-km-wide swath from 50-km altitude. A 2-axis gimbal enables independent targeting, allowing very high-resolution stereo imaging to generate digital topographic models (DTMs) with 4-m spatial scale and 0.5-m vertical precision over the 2-km swath from 50-km altitude. The gimbal also makes near-global (>95%) mapping of Europa possible at ≤50-m pixel scale, as well as regional stereo imaging. The NAC will also perform high-phase-angle observations to search for potential plumes. EIS Wide-angle Camera (WAC): The WAC has a 48°° x 24°° FOV, with a 218-μμrad IFOV, and is designed to acquire pushbroom stereo swaths along flyby ground-tracks. From an altitude of 50 km, the WAC achieves 11-m pixel scale over a 44-km

  10. Spatial and Statistical Evolution of Electrical Current Density in Active Region 12158 Producing an X-class Flare

    Kang, Jihye; Magara, Tetsuya; Inoue, Satoshi; Kubo, Yuki; Nishizuka, Naoto

    2016-05-01

    The formation of a current sheet in the solar corona where an intense electric current flows is one of the important processes leading to the onset of a solar flare. In this work, we investigate the temporal development of the distribution of electric current density derived from a time series of nonlinear force-free (NLFF) fields in active region 12158 (AR12158) which produces an X-class flare on 2014 September 10. A preflare NLFF field, where an intense electric current flows, reproduces an observed inverse-S shaped sigmoidal structure. The statistical distribution of electric current density has a double power-law profile during the evolution of AR12158. We discuss several key parameters of the double power-law profile and the time variations in them, which might be used as a quantitative indicator of flare onset.

  11. Na+,K(+)-ATPase pump currents in giant excised patches activated by an ATP concentration jump.

    Friedrich, T.; Bamberg, E; Nagel, G

    1996-01-01

    The giant-patch technique was used to study the Na+,K(+)-ATPase in excised patches from rat or guinea pig ventricular myocytes. Na+,K(+)-pump currents showed a saturable ATP dependence with aK(m) of approximately 150 microM at 24 degrees C. The pump current can be completely abolished by ortho-vanadate. Dissociation of vanadate from the enzyme in the absence of extracellular Na+ was slow, with a Koff of 3.10(-4) S-1 (K1 approximately 0.5 microM, at 24 degrees C). Stationary currents were mark...

  12. NON-NEUTRALIZED ELECTRIC CURRENT PATTERNS IN SOLAR ACTIVE REGIONS: ORIGIN OF THE SHEAR-GENERATING LORENTZ FORCE

    Georgoulis, Manolis K. [Research Center for Astronomy and Applied Mathematics of the Academy of Athens, 4 Soranou Efesiou Street, Athens GR-11527 (Greece); Titov, Viacheslav S.; Mikic, Zoran [Predictive Science, Inc., 9990 Mesa Rim Road, San Diego, CA 92121 (United States)

    2012-12-10

    Using solar vector magnetograms of the highest available spatial resolution and signal-to-noise ratio, we perform a detailed study of electric current patterns in two solar active regions (ARs): a flaring/eruptive and a flare-quiet one. We aim to determine whether ARs inject non-neutralized (net) electric currents in the solar atmosphere, responding to a debate initiated nearly two decades ago that remains inconclusive. We find that well-formed, intense magnetic polarity inversion lines (PILs) within ARs are the only photospheric magnetic structures that support significant net current. More intense PILs seem to imply stronger non-neutralized current patterns per polarity. This finding revises previous works that claim frequent injections of intense non-neutralized currents by most ARs appearing in the solar disk but also works that altogether rule out injection of non-neutralized currents. In agreement with previous studies, we also find that magnetically isolated ARs remain globally current-balanced. In addition, we confirm and quantify the preference of a given magnetic polarity to follow a given sense of electric currents, indicating a dominant sense of twist in ARs. This coherence effect is more pronounced in more compact ARs with stronger PILs and must be of sub-photospheric origin. Our results yield a natural explanation of the Lorentz force, invariably generating velocity and magnetic shear along strong PILs, thus setting a physical context for the observed pre-eruption evolution in solar ARs.

  13. Dengue vaccine: hypotheses to understand CYD-TDV-induced protection.

    Guy, Bruno; Jackson, Nicholas

    2016-01-01

    Dengue virus (DENV) is a human pathogen with a large impact on public health. Although no vaccine against DENV is currently licensed, a recombinant vaccine - chimeric yellow fever virus-DENV tetravalent dengue vaccine (CYD-TDV) - has shown efficacy against symptomatic dengue disease in two recent Phase III clinical trials. Safety observations were also recently reported for these trials. In this Opinion article, we review the data from recent vaccine clinical trials and discuss the putative mechanisms behind the observed efficacy of the vaccine against different forms of the disease, focusing on the interactions between the infecting virus, pre-existing host immunity and vaccine-induced immune responses. PMID:26639777

  14. Hypotheses for near-surface exchange of methane on Mars

    Hu, Renyu; Bloom, A. Anthony; Gao, Peter; Miller, Charles E.; Yung, Yuk L.

    2016-01-01

    The Curiosity rover recently detected a background of 0.7 ppb and spikes of 7 ppb of methane on Mars. This in situ measurement reorients our understanding of the Martian environment and its potential for life, as the current theories do not entail any geological source or sink of methane that varies sub-annually. In particular, the 10-fold elevation during the southern winter indicates episodic sources of methane that are yet to be discovered. Here we suggest a near-surface reservoir could ex...

  15. 75 FR 11623 - Agency Information Collection Activities: Notice of Request for Extension of Currently Approved...

    2010-03-11

    ... regarding resource allocation; program emphasis; marketing and promotion activities; training; and... this information to monitor the contractors-employment and training of minorities and women in...

  16. Participation of a persistent sodium current and calcium-activated nonspecific cationic current to burst generation in trigeminal principal sensory neurons.

    Tsuruyama, Kentaro; Hsiao, Chie-Fang; Chandler, Scott H

    2013-10-01

    The properties of neurons participating in masticatory rhythmogenesis are not clearly understood. Neurons within the dorsal trigeminal principal sensory nucleus (dPrV) are potential candidates as components of the masticatory central pattern generator (CPG). The present study examines in detail the ionic mechanisms controlling burst generation in dPrV neurons in rat (postnatal day 8-12) brain stem slices using whole cell and perforated patch-clamp methods. Nominal extracellular Ca(2+) concentration transformed tonic discharge in response to a maintained step pulse of current into rhythmical bursting in 38% of nonbursting neurons. This change in discharge mode was suppressed by riluzole, a persistent Na(+) current (INaP) antagonist. Veratridine, which suppresses the Na(+) channel inactivation mechanism, induced rhythmical bursting in nonbursting neurons in normal artificial cerebrospinal fluid, suggesting that INaP contributes to burst generation. Nominal extracellular Ca(2+) exposed a prominent afterdepolarizing potential (ADP) following a single spike induced by a 3-ms current pulse, which was suppressed, but not completely blocked, by riluzole. Application of BAPTA, a Ca(2+) chelator, intracellularly, or flufenamic acid, a Ca(2+)-activated nonspecific cationic channel (ICAN) antagonist, extracellularly to the bath, suppressed rhythmical bursting and the postspike ADP. Application of drugs to alter Ca(2+) release from endoplasmic reticulum also suppressed bursting. Finally, voltage-clamp methods demonstrated that nominal Ca(2+) facilitated INaP and induced ICAN. These data demonstrate for the first time that the previously observed induction in dPrV neurons of rhythmical bursting in nominal Ca(2+) is mediated by enhancement of INaP and onset of ICAN, which are dependent on intracellular Ca(2+). PMID:23883859

  17. Human female orgasm as evolved signal: a test of two hypotheses.

    Ellsworth, Ryan M; Bailey, Drew H

    2013-11-01

    We present the results of a study designed to empirically test predictions derived from two hypotheses regarding human female orgasm behavior as an evolved communicative trait or signal. One hypothesis tested was the female fidelity hypothesis, which posits that human female orgasm signals a woman's sexual satisfaction and therefore her likelihood of future fidelity to a partner. The other was sire choice hypothesis, which posits that women's orgasm behavior signals increased chances of fertilization. To test the two hypotheses of human female orgasm, we administered a questionnaire to 138 females and 121 males who reported that they were currently in a romantic relationship. Key predictions of the female fidelity hypothesis were not supported. In particular, orgasm was not associated with female sexual fidelity nor was orgasm associated with male perceptions of partner sexual fidelity. However, faked orgasm was associated with female sexual infidelity and lower male relationship satisfaction. Overall, results were in greater support of the sire choice signaling hypothesis than the female fidelity hypothesis. Results also suggest that male satisfaction with, investment in, and sexual fidelity to a mate are benefits that favored the selection of orgasmic signaling in ancestral females. PMID:23857519

  18. Ethnic density effects on psychological distress among Latino ethnic groups: an examination of hypothesized pathways.

    Bécares, Laia

    2014-11-01

    Studies among US Latinos provide the most consistent evidence of ethnic density effects. However, most studies conducted to date have focused on Mexican Americans, and it is not clear whether ethnic density effects differ across Latino sub-groups, generational status, or measures of ethnic density. In addition, the mechanisms behind ethnic density are not well understood. This study uses a multi-group structural equation modeling approach to analyze the Latino sample from the National Latino and Asian-American Study (n=1940) and examine ethnic density effects on psychological distress among Latino sub-groups, and explore two hypothesized mechanisms: increased neighborhood cohesion and reduced exposure to interpersonal racism. Results of the main effects between ethnic density and health, and of the hypothesized mechanisms, show clear differences across Latino ethnic groups, generational categories and measures of ethnic density. Findings highlight that ethnic density effects and their mechanisms depend on the current and historical context of Latino sub-groups, including reasons for migration and rights upon arrival. PMID:25305475

  19. Neural reflex pathways in intestinal inflammation: hypotheses to viable therapy.

    Willemze, Rose A; Luyer, Misha D; Buurman, Wim A; de Jonge, Wouter J

    2015-06-01

    Studies in neuroscience and immunology have clarified much of the anatomical and cellular basis for bidirectional interactions between the nervous and immune systems. As with other organs, intestinal immune responses and the development of immunity seems to be modulated by neural reflexes. Sympathetic immune modulation and reflexes are well described, and in the past decade the parasympathetic efferent vagus nerve has been added to this immune-regulation network. This system, designated 'the inflammatory reflex', comprises an afferent arm that senses inflammation and an efferent arm that inhibits innate immune responses. Intervention in this system as an innovative principle is currently being tested in pioneering trials of vagus nerve stimulation using implantable devices to treat IBD. Patients benefit from this treatment, but some of the working mechanisms remain to be established, for instance, treatment is effective despite the vagus nerve not always directly innervating the inflamed tissue. In this Review, we will focus on the direct neuronal regulatory mechanisms of immunity in the intestine, taking into account current advances regarding the innervation of the spleen and lymphoid organs, with a focus on the potential for treatment in IBD and other gastrointestinal pathologies. PMID:25963513

  20. Activity-dependent increases in local oxygen consumption correlate with postsynaptic currents in the mouse cerebellum in vivo

    Mathiesen, Claus; Caesar, Kirsten; Thomsen, Kirsten Engelund;

    2011-01-01

    metabolism via mitochondrial signaling, but whether this also occurs in the intact brain is unknown. Here we applied a pharmacological approach to dissect the effects of ionic currents and cytosolic Ca(2+) rises of neuronal origin on activity-dependent rises in CMRO(2). We used two-photon microscopy and...

  1. Active damping of LLCL-filter resonance based on LC-trap voltage and capacitor current feedback

    Huang, Min; Wang, Xiongfei; Loh, Poh Chiang;

    2015-01-01

    paper, different feedback coefficients like the proportional, derivative, integral, high pass and low pass feedback coefficients of the filter capacitor current and the LC-trap circuit voltage are investigated for damping the filter resonance. Active damping methods are analyzed by using the concept of...

  2. Active harmonic filtering using current-controlled, grid-connected DG units with closed-loop power control

    He, Jinwei; Li, Yun Wei; Blaabjerg, Frede;

    2014-01-01

    The increasing application of nonlinear loads may cause distribution system power quality issues. In order to utilize distributed generation (DG) unit interfacing converters to actively compensate harmonics, this paper proposes an enhanced current control approach, which seamlessly integrates...... voltage detection are not necessary for the proposed harmonic compensation method. Moreover, a closed-loop power control scheme is employed to directly derive the fundamental current reference without using any phase-locked loops (PLL). The proposed power control scheme effectively eliminates the impacts...... of steady-state fundamental current tracking errors in the DG units. Thus, an accurate power control is realized even when the harmonic compensation functions are activated. In addition, this paper also briefly discusses the performance of the proposed method when DG unit is connected to a grid with...

  3. 75 FR 57467 - Agency Information Collection Activities: Renewal of Currently Approved Collection (3064-0137...

    2010-09-21

    ... on the renewal of an existing information collection, as required by the PRA. On July 1, 2010 (75 FR... collection: Interagency Guidance on Asset Securitization Activities. (OMB No. 3064-0137). No comments were... Securitization Activities. OMB Number: 3064-0137. Form Number: None. Frequency of Response: On occasion....

  4. Current Situation and Analysis of Geography Teachers' Active Learning Knowledge and Usage in Turkey

    Tuna, Fikret

    2012-01-01

    In parallel to the developments in the approach to education, the secondary education geography curriculum in Turkey was renewed in 2005. This new programme encourages the use of active learning methods and techniques in the classroom by adopting the idea that students should construct and interpret knowledge by actively participating in the…

  5. CNTF inhibits high voltage activated Ca2+ currents in fetal mouse cortical neurones

    Holm, Ninna R; Christophersen, Palle; Hounsgaard, Jørn;

    2002-01-01

    h. CNTF reduced the current of all pharmacological subtypes of Ca channels as shown by use of selective blockers of L, N, and P/Q type Ca channels (nifedipine, omega-conotoxin MVIIA, omega-agatoxin IVA). The Ca channel depression was mediated via the CNTF receptor, because enzymatic cleavage of the...... alpha-subunit glycerophosphatidylinositol anchor of the receptor eliminated the response. The CNTF effect was not elicited through pertussis toxin-sensitive G proteins. Other neurotrophic factors like neurotrophin-3 and insulin-like growth factor-I had no effect on the Ca2+ currents. These results may...

  6. Pickles and Ice Cream! Food Cravings in Pregnancy: Hypotheses, Preliminary Evidence, and Directions for Future Research

    Natalia C. Orloff

    2014-09-01

    Full Text Available Women in the United States experience an increase in food cravings at two specific times during their life, 1 perimenstrually and 2 prenatally. The prevalence of excess gestational weight gain (GWG is a growing concern due to its association with adverse health outcomes in both mothers and children. To the extent that prenatal food cravings may be a determinant of energy intake in pregnancy, a better understanding of craving etiology could be crucial in addressing the issue of excessive GWG. This paper reviews the available literature to corroborate and/or dispute some of the most commonly accepted hypotheses regarding the causes of food cravings during pregnancy, including a role of 1 hormonal changes, 2 nutritional deficits, 3 pharmacologically active ingredients in the desired foods, and 4 cultural and psychosocial factors. An existing model of perimenstrual chocolate craving etiology serves to structure the discussion of these hypotheses. The main hypotheses discussed receive little support, with the notable exception of a postulated role of cultural and psychosocial factors. The presence of cravings during pregnancy is a common phenomenon across different cultures, but the types of foods desired and the adverse impact of cravings on health may be culture-specific. Various psychosocial factors appear to correlate with excess GWG, including the presence of restrained eating. Findings strongly suggest that more research be conducted in this area. We propose that future investigations fall into one of the four following categories: 1 validation of food craving and eating-related measures specifically in pregnant populations, 2 use of ecological momentary assessment to obtain real time data on cravings during pregnancy, 3 implementation of longitudinal studies to address causality between eating disorder symptoms, food cravings, and gestational weight gain, and 4 development of interventions to ensure proper prenatal nutrition and prevent excess

  7. Current Statistics System Fails to Reflect New Changes in International Trade Activities

    万光彩; 刘莉

    2007-01-01

    Today developed countries mainly participate in international trade via their foreign affiliates and intermediate goods are more frequently traded as a result of increasingly deepening international divisions of labour.Against this background,the current trade statistical system that is characterized by the statistical principle of cross-border trade and production,and the custom’s registration data collection method,greatly exaggerate the trade imbalance between China and America. Consequently,it is necessary for the Chinese nation to overcome the shortcomings of the current statistical system so as to evaluate more fairly the trade imbalance between China and America by referring to the Ownership-Based Framework of the complimentary statistical system under the US Current Account.This article, on the basis of the statistical principle of oumership,attempts to regulate the distorted trade imbalance resulting from the current trade statistical system,and aims for an increased understanding of the trade imbalance between China and America from a theoretical background,as well as from the points of view of practitioners and decision makers.

  8. AI and sensor applications in 'smart homes':current research activity and applications in domestic homes

    Bausch, Nils; Tewkesbury, Giles

    2013-01-01

    This paper introduces the current research in the area of Smart Homes and then introduces a modelling approach for a domestic home. The modelling approach for a domestic home in the second part of this paper investigates the inherent properties of a house, which could facilitate further research into energy flow, timing methods and optimization.

  9. 78 FR 69134 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Current...

    2013-11-18

    ...; Current Population Survey--Displaced Worker, Job Tenure, and Occupational Mobility Supplement ACTION... displacement, job tenure, and occupational mobility will enable analysts to obtain a more complete picture of... published in the Federal Register on July 29, 2013 (78 FR 50450). Interested parties are encouraged to...

  10. Grid-Current-Feedback Active Damping for LCL Resonance in Grid-Connected Voltage-Source Converters

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2016-01-01

    adding a virtual impedance across the grid-side inductance. This added impedance is more precisely represented by a series RL branch in parallel with a negative inductance. The negative inductance helps to mitigate phase lag caused by time delays found in a digitally controlled system. The mitigation of......This paper investigates active damping of LCL-filter resonance in a grid-connected voltage-source converter with only grid-current feedback control. Basic analysis in the s-domain shows that the proposed damping technique with a negative high-pass filter along its damping path is equivalent to...... phase-lag, in turn, helps to shrink the region of nonminimum-phase behavior caused by negative virtual resistance inserted unintentionally by most digitally implemented active damping techniques. The presented high-pass-filtered active damping technique with a single grid-current feedback loop is thus a...

  11. Analysis and design of grid-current-feedback active damping for LCL resonance in grid-connected voltage source converters

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2014-01-01

    This paper investigates the active damping of LCL-filter resonance within single-loop grid current control of grid-connected voltage source converters. First, the basic analysis in the continuous s-domain reveals that the grid-current-feedback active damping forms a virtual impedance across the...... grid-side inductor, and the use of a high-pass filter with a negative sign shapes the virtual impedance by an RL damper paralleled by a negative inductance. It is further found that such a negative virtual inductance plays a critical role in mitigating the phase lag caused by the time delay in a...... digital control system. The instability induced by the negative virtual resistance, which is commonly experienced in the feedback-type active damping, can thus be avoided. A systematic design method of the highpass filter is also proposed by the help of root locus analysis in the discrete z-domain. Lastly...

  12. Information on current status of equipment and activities for extension of NPP Kozloduy life time

    The NPP Kozloduy personnel activities are described directed to undertake measures to overcome the difficulties entailed by equipment failures and human errors in order to avoid recurrent emergency events and to reduce their total numbers. 12 figs, 2 tabs

  13. 77 FR 71018 - Agency Information Collection Activities; Extension of a Currently Approved Collection; Comment...

    2012-11-28

    ... Office of Juvenile Justice and Delinquency Prevention Agency Information Collection Activities; Extension... Juvenile Justice and Delinquency Prevention, Office of Justice Programs, Department of Justice. ACTION: 30... the collection: The Office of Juvenile Justice and Delinquency Prevention, Office of Justice...

  14. Aging and stress: past hypotheses, present approaches and perspectives.

    Garrido, Pedro

    2011-02-01

    Brain aging has been suggested to be conditioned by an excessive glucocortioid secretion leading to damages on brain areas involved not only in cognitive and emotional processes but also in the control of the activity of the hypothalamic-pituitary adrenal axis. This review describes some of the hypothesis that try to explain the relation between the dysregulation of the stress response and brain aging, focusing on corticosterone but also on neurotransmission in the hippocampus, the prefrontal cortex and the amygdala. Moreover, different molecular factors can account for an enhanced vulnerability of the aged brain to stress exposure, specially for resilience. Among them, good candidates could be those mechanisms determining the levels of corticosterone in the brain, several molecules downstream glucocorticoid receptor activation (ie: heat shock proteins, BAG-1) or even the epigenetic programming of the HPA axis in early stages. In conclusion, genetic and environmental factors (early life stress, chronic stress during adulthood) can produce an enhanced vulnerability and a reduced resilience of the brain to subsequent stress exposures or to metabolic challenges leading, in turn, to an unsuccessful aging of the brain. However, results obtained with the use of the environmental enrichment model in animals, added to several results in humans also described in this review suggest that positive environmental factors (cognitive-demanding tasks or physical exercise) can help to maintain neuronal plasticity during aging and to protect the brain against the damaging effects of stress exposure. PMID:22396868

  15. Therapeutic mechanisms of classic hallucinogens in the treatment of addictions: from indirect evidence to testable hypotheses.

    Bogenschutz, Michael P; Pommy, Jessica M

    2012-01-01

    Alcohol and drug addiction are major public health problems, and existing treatments are only moderately effective. Although there has been interest for over half a century in the therapeutic use of classic hallucinogens to treat addictions, clinical research with these drugs was halted at an early stage in the early 1970s, leaving many fundamental questions unanswered. In the past two decades, clinical research on classic hallucinogens has resumed, although addiction treatment trials are only now beginning. The purpose of this paper is to provide a targeted review of the research most relevant to the therapeutic potential of hallucinogens, and to integrate this information with current thinking about addiction and recovery. On the basis of this information, we present a heuristic model which organizes a number of hypotheses that may be tested in future research. We conclude that existing evidence provides a convincing rationale for further research on the effects of classic hallucinogens in the treatment of addiction. PMID:22761106

  16. Covariation between personalities and individual differences in coping with stress: Converging evidence and hypotheses

    Claudio CARERE, Doretta CARAMASCHI, Tim W. FAWCETT

    2010-12-01

    Full Text Available In the past decade there has been a profusion of studies highlighting covariation between individual differences in stress physiology and behavioural profiles, here called personalities. Such individual differences in ways of coping with stress are relevant both in biomedicine, since different personalities may experience a different stress and disease vulnerability, and in behavioural ecology, since their adaptive value and evolutionary maintenance are the subject of debate. However, the precise way in which individual stress differences and personalities are linked is unclear. Here we provide an updated overview of this covariation across different species and taxa, consider its functional significance and present working hypotheses for how behavioural and physiological responses to stress might be causally linked, affecting life-history traits such as dispersal and life-span [Current Zoology 56 (6: 728–740, 2010].

  17. Local membrane deformations activate Ca2+-dependent K+ and anionic currents in intact human red blood cells.

    Agnieszka Dyrda

    Full Text Available BACKGROUND: The mechanical, rheological and shape properties of red blood cells are determined by their cortical cytoskeleton, evolutionarily optimized to provide the dynamic deformability required for flow through capillaries much narrower than the cell's diameter. The shear stress induced by such flow, as well as the local membrane deformations generated in certain pathological conditions, such as sickle cell anemia, have been shown to increase membrane permeability, based largely on experimentation with red cell suspensions. We attempted here the first measurements of membrane currents activated by a local and controlled membrane deformation in single red blood cells under on-cell patch clamp to define the nature of the stretch-activated currents. METHODOLOGY/PRINCIPAL FINDINGS: The cell-attached configuration of the patch-clamp technique was used to allow recordings of single channel activity in intact red blood cells. Gigaohm seal formation was obtained with and without membrane deformation. Deformation was induced by the application of a negative pressure pulse of 10 mmHg for less than 5 s. Currents were only detected when the membrane was seen domed under negative pressure within the patch-pipette. K(+ and Cl(- currents were strictly dependent on the presence of Ca(2+. The Ca(2+-dependent currents were transient, with typical decay half-times of about 5-10 min, suggesting the spontaneous inactivation of a stretch-activated Ca(2+ permeability (PCa. These results indicate that local membrane deformations can transiently activate a Ca(2+ permeability pathway leading to increased [Ca(2+](i, secondary activation of Ca(2+-sensitive K(+ channels (Gardos channel, IK1, KCa3.1, and hyperpolarization-induced anion currents. CONCLUSIONS/SIGNIFICANCE: The stretch-activated transient PCa observed here under local membrane deformation is a likely contributor to the Ca(2+-mediated effects observed during the normal aging process of red blood cells, and

  18. Co-injection Current Transformer: An Active Device in the AGS Facility Safety System

    Reece, R. K.; Smith, G. A.

    1997-05-01

    The AGS facility can change operating parameters (particle, intensity, extraction mode, etc.) in a pulse-to-pulse mode. This will soon become essential in order to fill the RHIC accelerator rings interleaved with providing beam to the fixed target experiments at the AGS. However, since the AGS intensity for fixed targets is much greater than that required for RHIC, a means of ensuring that only the proper beam and intensity is extracted to RHIC has been developed. A beam current transformer in the AGS accelerator chain will detect the beam intensity and provide the necessary permits for extraction to RHIC only if the beam intensity is below a specified threshold. System details of this dual, redundant current transformer, as well as the system constraints imposed by the various safety requirements, will be presented. The interdependence of these two issues and evolution of the overall design will also be described.

  19. A highly calcium-selective cation current activated by intracellular calcium release in MDCK cells.

    Delles, C; Haller, T; Dietl, P

    1995-08-01

    1. The whole-cell patch clamp technique and fluorescence microscopy with the Ca2+ indicators fura-2 and fluo-3 were used to measure the whole-cell current and the free intracellular Ca2+ concentration ([Ca2+]i) in Madin-Darby canine kidney (MDCK) cells. 2. In a Ca(2+)-free bath solution, thapsigargin (TG) caused a transient increase of [Ca2+]i. Subsequent addition of Ca2+ caused a long lasting elevation of [Ca2+]i. 3. In a Ca(2+)-free bath solution, extracellular application of TG, ATP or ionomycin, or intracellular application of inositol 1,4,5-trisphosphate (IP3), caused a small but significant inward current (Iin) and a transient outward Ca(2+)-dependent K+ current (IK(Ca)), consistent with intracellular Ca2+ release. Subsequent addition of Ca2+ induced a prominent Iin with a current density of -4.2 +/- 0.7 pA pF-1. This Iin was unaffected by inositol 1,3,4,5-tetrakisphosphate (IP4). 4. Na+ replacement by mannitol, N-methyl-D-glucamine+ (NMG+), aminomethylidin-trimethanol+ (Tris+) or choline+ reduced Iin by 54, 65, 52 and 56%, respectively. This indicates an apparent Ca2+ selectivity over Na+ of 26:1. Iin was, however, unaffected by replacing Cl- with gluconate- or by the K+ channel blocker charybdotoxin (CTX). 5. Iin was completely blocked by La3+ (IC50 = 0.77 microM). Consistently, La3+ completely reversed the TG-induced elevation of [Ca2+]i. SK&F 96365 (1-[3-(4-methoxyphenyl)-propoxyl]-1-(4-methoxy-phenyl)-ethyl-1H-im idazole) HCl did not inhibit the TG-induced Iin. It did, however, exhibit a biphasic effect on [Ca2+]i, consisting of an initial Ca2+ decay and a subsequent Ca2+ elevation. La3+ completely reversed the SK&F 96365-induced elevation of [Ca2+]i. 6. In the absence of Na+, Iin was dependent on the bath Ca2+ concentration (EC50 = 1.02 mM). Ca2+ replacement by Ba2+ or Mn2+ resulted in a reduction of Iin by 95 and 94%, respectively. 7. From these experiments we conclude that Ca2+ release from intracellular Ca2+ stores, induced by different independent

  20. Actions of arginine polyamine on voltage and ligand-activated whole cell currents recorded from cultured neurones.

    Scott, R. H.; Sweeney, M. I.; Kobrinsky, E. M.; Pearson, H. A.; Timms, G. H.; Pullar, I A; Wedley, S.; Dolphin, A. C.

    1992-01-01

    1. Toxins from invertebrates have proved useful tools for investigation of the properties of ion channels. In this study we describe the actions of arginine polyamine which is believed to be a close analogue of FTX, a polyamine isolated from the American funnel web spider, Agelenopsis aperta. 2. Voltage-activated Ca2+ currents and Ca(2+)-dependent Cl- currents recorded from rat cultured dorsal root ganglion neurones were reversibly inhibited by arginine polyamine (AP; 0.001 to 100 microM). Lo...

  1. Current Status of Activation Analysis Using Tsing Hua Open-Pool Reactor

    Activation analysis may be considered to be one of the most practical applications in the utilization of research reactor. One of the obvious advantages of this method is its high sensitivity for many elements. Using the average research reactor, it is feasible to determine the content of element in various matrices, to an order of as low as 0,001 microgram. Although the detection, sensitivities of other analytical methods also have been improved very much in recent years by using newly developed instruments, these methods can rival the activation analysis in sensitivity for only a certain limited number of elements. Thus, at present, the technique of activation analysis seems to offer the highest sensitivity for the greatest number of elements

  2. Changes in solar oscillation frequencies during the current activity maximum analysis and interpretation

    Dziembowski, W A; Goode, Philip R.

    2001-01-01

    We describe systematic changes in the centroid frequencies and the splitting coefficients as found using data from MDI on board SOHO, covering cycle 23. The data allow us to construct a seismic map of the evolving solar activity -- covering all latitudes. At lower latitudes, the temporal evolution closely tracks that of {\\it butterfly diagram}. The additional information from higher latitudes in the map is of a significant activity in the polar region, peaking at activity minimum in 1996. The most plausible source of solar oscillation frequency changes over the solar cycle is the evolution of the radial component of the small-scale magnetic field. The amplitude of the required mean field changes is about 100 G at the photosphere, and increasing going inward.

  3. Voltage- and current-activated metal–insulator transition in VO2-based electrical switches: a lifetime operation analysis

    Aurelian Crunteanu, Julien Givernaud, Jonathan Leroy, David Mardivirin, Corinne Champeaux, Jean-Christophe Orlianges, Alain Catherinot and Pierre Blondy

    2010-01-01

    Full Text Available Vanadium dioxide is an intensively studied material that undergoes a temperature-induced metal–insulator phase transition accompanied by a large change in electrical resistivity. Electrical switches based on this material show promising properties in terms of speed and broadband operation. The exploration of the failure behavior and reliability of such devices is very important in view of their integration in practical electronic circuits. We performed systematic lifetime investigations of two-terminal switches based on the electrical activation of the metal–insulator transition in VO2 thin films. The devices were integrated in coplanar microwave waveguides (CPWs in series configuration. We detected the evolution of a 10 GHz microwave signal transmitted through the CPW, modulated by the activation of the VO2 switches in both voltage- and current-controlled modes. We demonstrated enhanced lifetime operation of current-controlled VO2-based switching (more than 260 million cycles without failure compared with the voltage-activated mode (breakdown at around 16 million activation cycles. The evolution of the electrical self-oscillations of a VO2-based switch induced in the current-operated mode is a subtle indicator of the material properties modification and can be used to monitor its behavior under various external stresses in sensor applications.

  4. Tea and human health: biomedical functions of tea active components and current issues.

    Chen, Zong-mao; Lin, Zhi

    2015-02-01

    Originating in China, tea and tea planting have spread throughout the world since the middle of the Tang dynasty. Now people from 160 countries in the world are accustomed to tea drinking. A brief history of tea's medicinal role in China and its spread to the world are introduced. The effectiveness of tea active components and tea drinking on major human diseases, including cancer, metabolic syndrome, cardiovascular disease, and neurodegenerative diseases, is discussed. Also presented are some related issues, such as the bioavailability of tea active components, the new formulations of tea polyphenols, and the safety for consumers of dietary supplements containing tea polyphenols. PMID:25644464

  5. [Consciousness functions in psychoses. Concepts, empirism and hypotheses].

    Hemmingsen, R

    1991-04-15

    Schizophrenia may be described as a disease where speech, bodily language and social responsiveness are obvious expressions of a deteriorated ability to interact with the surroundings in a precise and relevant way. The lack of precision and relevance pertains to perception and recall as well as communication and action. The deficient potential for activation of the prefrontal cerebral cortex is a neurobiological correlate to the lesion of precise and relevant planning and expression. Impairment of formal thought and language in schizophrenia are suggested to result from a developmental disorder pertaining to language and concept formation (apperception). In reactive psychoses with dissociative disturbances of consciousness there is an inefficient capacity for adapting to external reality; thus relevant conscious planning and interaction with the outside world are impaired. Clinically a distractibility of a tematic nature ensues. Except for catastrophic events, psychotic reactions cannot be predicted from analysis of the actual experience--neither concerning the external nor the internal aspects of conscious awareness. Sometimes, however, previous events relating to the formation of the self may add explanatory value to the analysis of reactive psychosis. In some cases biological predisposition is the decisive determinant. The normal discrimination between sense-perception and imagination has a counterpart in the dichotomy of awareness of the outside world versus awareness of the self. The following are examples of psychotic experience where the normal ability for dichotomic discrimination may be damaged: Illusions of affect, hallucinations, Schneider's first rank symptoms, "Anwesenheit" and consciousness of time.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2024342

  6. Ocean's Skeletal Structures, Hypotheses and Interpretation of the Phenomenon

    Rantsev-Kartinov, V A

    2004-01-01

    An analysis of databases of photographic images of ocean's surface, taken from various altitudes and for various types of rough ocean surface, revealed the presence of an ocean's skeletal structures (OSS). The OSSs differ from the formerly found skeletal structures (SS) only by the fact that OSS, in their interior, are filled in with closely packed blocks of a smaller size, up to thin capillaries of tens of micron in size. According to suggested hypothesis, the structure-forming dust is produced due to volcanic activity and atmospheric electricity. Such SS may fall on the ocean surface and produce an OSS. This idea is supported by the adsorption of air bubbles in the water by the SS to give a partial flotation of SS. In the sea water, various substances in different phase states of matter are in touch. This suggests the hypothesis, for the possibility of the action of surface tension even on the blocks of SS which is immersed in the sea. This phenomenon results in the aggregation of blocks deposited from the ...

  7. THE CURRENT STAGE OF TRANSNATIONALIZATION WORLD ECONOMY AND ACTIVITIES IN UKRAINE TNC

    В.Є. НАМОНЮК

    2011-12-01

    Full Text Available  In the article the essence of transnational corporations is considered, the principal trends of trans-nationalization of world economy at the present stage are estimated, the main indicators and areas of TNCs activities in the world and in Ukraine are determined, the Ukrainian investment climate is analysed.

  8. 77 FR 37063 - Agency Information Collection Activities: Extension, Without Change, of a Currently Approved...

    2012-06-20

    ... SECURITY United States Immigration and Customs Enforcement Agency Information Collection Activities...-0026). The Department of Homeland Security, U.S. Immigration and Customs Enforcement (ICE), will submit... Homeland Security (DHS), John Ramsay, Program (Forms) Manager, U.S. Immigration and Customs...

  9. 77 FR 11148 - Agency Information Collection Activities: Extension, Without Change, of a Currently Approved...

    2012-02-24

    ... SECURITY United States Immigration and Customs Enforcement Agency Information Collection Activities...-0026. The Department of Homeland Security, U.S. Immigration and Customs Enforcement (ICE), will submit... Homeland Security (DHS), John Ramsay, Program (Forms) Manager, U.S. Immigration and Customs...

  10. An Assessment of the Current LEO Debris Environment and the Need for Active Debris Removal

    Liou, Jer-Chyi

    2010-01-01

    The anti-satellite test on the Fengun-1 C weather satellite in early 2007 and the collision between Iridium 33 and Cosmos 2251 in 2009 dramatically altered the landscape of the human-made orbital debris environment in the low Earth orbit (LEO). The two events generated approximately 5500 fragments large enough to be tracked by the U.S. Space Surveillance Network. Those fragments account for more than 60% increase to the debris population in LEO. However, even before the ASAT test, model analyses already indicated that the debris population (for those larger than 10 cm) in LEO had reached a point where the population would continue to increase, due to collisions among existing objects, even without any future launches. The conclusion implies that as satellites continue to be launched and unexpected breakup events continue to occur, commonly-adopted mitigation measures will not be able to stop the collision-driven population growth. To remediate the debris environment in LEO, active debris removal must be considered. This presentation will provide an updated assessment of the debris environment after the Iridium 33/Cosmos 2251 collision, an analysis of several future environment projections based on different scenarios, and a projection of collision activities in LEO in the near future. The need to use active debris removal to stabilize future debris environment will be demonstrated and the effectiveness of various active debris removal strategies will be quantified.

  11. Measuring disease activity in Crohn's disease: what is currently available to the clinician

    D’Incà R

    2014-05-01

    Full Text Available Renata D'Incà, Roberta Caccaro Department of Surgical, Oncological and Gastroenterological Sciences, Gastroenterology Section, University of Padua, Padua, Italy Abstract: Crohn's disease (CD is a chronic inflammatory bowel disease characterized by a relapsing-remitting clinical behavior and dominated by intestinal inflammation. Being a chronic disorder that with time develops into a disabling disease, it is important to monitor the severity of inflammation to assess the efficacy of medication, rule out complications, and prevent progression. This is particularly true now that the goals of treatment are mucosal healing and deep remission. Endoscopy has always been the gold standard for assessing mucosal activity in CD, but its use is limited by its invasiveness and its inability to examine the small intestine, proximal to the terminal ileum. Enteroscopy and the less invasive small bowel capsule endoscopy enable the small bowel to be thoroughly explored and scores are emerging for classifying small bowel disease activity. Cross-sectional imaging techniques (ultrasound, magnetic resonance, computed tomography are emerging as valid tools for monitoring CD patients, assessing inflammatory activity in the mucosa and the transmucosal extent of the disease, and for excluding extra-intestinal complications. Neither endoscopy nor imaging are suitable for assessing patients frequently, however. Noninvasive markers such as C-reactive protein, and fecal biomarkers such as calprotectin and lactoferrin, are therefore useful to confirm the inflammatory burden of the disease and to identify patients requiring further investigations. Keywords: activity, biomarkers, Crohn, endoscopy, imaging, monitoring

  12. Preliminary overview of current nation-wide research activities related to surface mine land reclamation

    Streib, Dr., Donald L.; Major, Robert L.; Carter, Ralph P.

    1976-04-01

    A total of five federal agencies and departments are funding reclamation research associated with understanding the environmental and socio-economic impacts of the surface mining of coal. Each organization, depending upon its preconceived mission, approaches the funding from a slightly different direction. While much of the current reclamation research is addressing interesting and real site-specific problems, almost all of it has been initiated without a comprehensive national research plan. Duplication and overlap, disorganization, aggravation, and poor coordination are common faults. There is a strong belief that no one in the government is cognizant of the total reclamation research effort. There does not exist a clear statement of the problems in a regional or national context. It is impossible even to obtain a good estimate regarding the amount of land disturbed each year by surface coal mining. Also, extraction practices of uranium, oil shale, and other mineral mining require closer scrutiny to determine the research efforts required to minimize environmental, health and socio-economic impacts. There is a need to develop a coherent national program that can begin to piece together the patchwork efforts currently underway and identify the information needed to plan and implement a national land reclamation program that can assess the environmental impacts of coal development and provide cost-effective techniques for reclaiming and rehabilitating mined land to productive end use. Much of the past and current research information has not been transferred from the researcher to the user. Therefore, in many instances programs are being initiated to gather information that has already been developed. Any effort that does not assign the highest priority to the transfer of research data to the user is useless. Separate abstracts were prepared for two included reports.

  13. Current status and issues of nuclear human resource development/General activities of Japan nuclear human resource development network

    The Japan Nuclear Human Resource Development Network (JN-HRD Net) was established in November 2010 with the aim of developing a framework for mutual cooperation and information sharing among nuclear-related organizations. Although the tasks and goals of developing human resources in the nuclear field have been shifted since the accident at the Tokyo Electric Power Company (TEPCO) Fukushima Daiichi Nuclear Power Plant, the necessity of fostering capable personnel in this field stays unchanged and the importance of our network activities has further emphasized. The meeting of JN-HRD Net was held on the 5th of February 2013, where its activities by each field were reported and views and opinions were actively exchanged between more than 90 participants. This paper briefly describes current status and issues of JN-HRD Net and its general activities conducted by the JN-HRD Net secretariat. (J.P.N.)

  14. Antiarrhythmic properties of a rapid delayed-rectifier current activator in rabbit models of acquired long QT syndrome

    Diness, Thomas G; Yeh, Yung-Hsin; Qi, Xiao Yan; Chartier, Denis; Tsuji, Yukiomi; Hansen, Rie S; Olesen, Søren-Peter; Grunnet, Morten; Nattel, Stanley

    2008-01-01

    AIMS: Impaired repolarization in cardiac myocytes can lead to long QT syndrome (LQTS), with delayed repolarization and increased susceptibility to Torsades de Pointes (TdP) arrhythmias. Current pharmacological treatment of LQTS is often inadequate. This study sought to evaluate the antiarrhythmic...... effect of a novel compound (NS1643) that activates the rapid delayed-rectifier K+ current, I(Kr), in two rabbit models of acquired LQTS. METHODS AND RESULTS: We used two clinically relevant in vivo rabbit models of TdP in which we infused NS1643 or vehicle: (i) three-week atrioventricular block with...... ventricular bradypacing; (ii) dofetilide-induced I(Kr) inhibition in methoxamine-sensitized rabbits. In addition, we studied effects on ionic currents in cardiomyocytes with I(Kr) suppressed by bradycardia remodelling or dofetilide exposure. Bradypaced rabbits developed QT interval prolongation, spontaneous...

  15. Biological Activities and Bioavailability of Mangosteen Xanthones: A Critical Review of the Current Evidence

    Mark L. Failla

    2013-08-01

    Full Text Available Mangosteen (Garcinia mangostana L. is a tropical tree native to Southeast Asia that produces a fruit whose pericarp contains a family of tricyclic isoprenylated polyphenols referred to as xanthones. Numerous in vitro studies have shown that these xanthones possess anti-oxidant, anti-proliferative, pro-apoptotic, anti-inflammatory and anti-carcinogenic activities. Aggressive marketing of such health promoting benefits has resulted in mangosteen’s classification as a “superfruit”. This has led to sales of mangosteen containing beverages in USA alone exceeding $200 million in 2008 despite very limited animal and human studies. This review will (a critically address recent reports of in vivo studies on the bioavailability and metabolism of mangosteen xanthones, (b update the in vitro and in vivo data on anti-cancer and anti-inflammatory activities of mangosteen xanthones, and (c suggest needed areas of inquiry regarding the absorption, metabolism and efficacy of mangosteen xanthones.

  16. Effects of currently used pesticides in assays for estrogenicity, androgenicity, and aromatase activity in vitro

    Andersen, Helle Raun; Vinggaard, Anne; Rasmussen, Thomas Høj;

    2002-01-01

    Twenty-four pesticides were tested for interactions with the estrogen receptor (ER) and the androgen receptor (AR) in transactivation assays. Estrogen-like effects on MCF-7 cell proliferation and effects on CYP19 aromatase activity in human placental microsomes were also investigated. Pesticides ...... to the natural ligands, the integrated response in the organism might be amplified by the ability of the pesticides to act via several mechanism and the frequent simultaneous exposure to several pesticides.......Twenty-four pesticides were tested for interactions with the estrogen receptor (ER) and the androgen receptor (AR) in transactivation assays. Estrogen-like effects on MCF-7 cell proliferation and effects on CYP19 aromatase activity in human placental microsomes were also investigated. Pesticides...... to their frequent use in Danish greenhouses. In addition, the metabolite mercaptodimethur sulfoxide, the herbicide tribenuron-methyl, and the organochlorine dieldrin, were included. Several of the pesticides, dieldrin, endosulfan, methiocarb, and fenarimol, acted both as estrogen agonists and...

  17. Modern sedentary activities promote overconsumption of food in our current obesogenic environment.

    Chaput, J-P; Klingenberg, L; Astrup, A; Sjödin, A M

    2011-05-01

    Achieving body-weight stability is certainly challenging in today's obesogenic environment. Every day we are surrounded and affected by stimuli that act on our behaviour. A common feature of these stimuli is that they increase our comfort and well-being, but unfortunately they promote a positive caloric balance. Intriguingly, the preponderance of sedentary lifestyles is not only a matter of the amount of calories expended. A careful examination of modern sedentary activities reveals that they also promote overconsumption of food. This is particularly the case with television viewing, video game playing, cognitive working, music listening and short sleeping. Moreover, the increased food intake in the absence of hunger observed with the practice of these modern-life activities emphasizes that the hedonic value of food intake plays an important role. These observations suggest that our quest for reward and pleasure is not fine tuned to our biology, and the development of coping strategies is needed. PMID:20576006

  18. The Current State-Of-The-Art In Active Region Seismology

    Moradi, Hamed

    2012-01-01

    Helioseismology is the study of the variations in the internal structure and properties of the dynamics of the Sun from measurements of its surface oscillations. With the 2010 launch of the Solar Dynamics Observatory (SDO) we are undoubtedly approaching a new dawn for local helioseismology, as the extent and quality of raw surface oscillation data has never been better. However, advances in theory and modelling are still required to fully utilise these data, especially in magnetic active regi...

  19. Current Status of Trace Metal Pollution in Soils Affected by Industrial Activities

    Ehsanul Kabir; Sharmila Ray; Ki-Hyun Kim; Hye-On Yoon; Eui-Chan Jeon; Yoon Shin Kim; Yong-Sung Cho; Seong-Taek Yun; Richard J. C. Brown

    2012-01-01

    There is a growing public concern over the potential accumulation of heavy metals in soil, owing to rapid industrial development. In an effort to describe the status of the pollutions of soil by industrial activities, relevant data sets reported by many studies were surveyed and reviewed. The results of our analysis indicate that soils were polluted most significantly by metals such as lead, zinc, copper, and cadmium. If the dominant species are evaluated by the highest mean concentration obs...

  20. A Self-Sensing Active Magnetic Bearing Based on a Direct Current Measurement Approach

    Du Rand, Carel P.; George van Schoor; Niemann, Andries C.

    2013-01-01

    Active magnetic bearings (AMBs) have become a key technology in various industrial applications. Self-sensing AMBs provide an integrated sensorless solution for position estimation, consolidating the sensing and actuating functions into a single electromagnetic transducer. The approach aims to reduce possible hardware failure points, production costs, and system complexity. Despite these advantages, self-sensing methods must address various technical challenges to maximize the performance the...

  1. Noninvasive reconstruction of cardiac electrical activity: update on current methods, applications and challenges

    Cluitmans, M.J.M.; Peeters, R.L.M.; Westra, R.L.; Volders, P. G. A.

    2015-01-01

    Electrical activity at the level of the heart muscle can be noninvasively reconstructed from body-surface electrocardiograms (ECGs) and patient-specific torso-heart geometry. This modality, coined electrocardiographic imaging, could fill the gap between the noninvasive (low-resolution) 12-lead ECG and invasive (high-resolution) electrophysiology studies. Much progress has been made to establish electrocardiographic imaging, and clinical studies appear with increasing frequency. However, many ...

  2. Head-cloaca controlled current stunning: assessment of brain and heart activity and meat quality.

    Lambooij, E; Reimert, H G M; Workel, L D; Hindle, V A

    2012-01-01

    1. Behavioural and neural responses of 65 broilers to head-to-cloaca electrical stunning were evaluated and meat quality was assessed on two groups of 25 broilers stunned either head to cloaca, or in a conventional water bath method. 2. On the EEG recordings, a general epileptiform insult was observed when applying a current of 100 mA (100 Hz) or 70 mA (70 Hz) for 1·5 s. This general epileptiform insult shows a tonic, clonic and exhaustion phase followed by spikes of alpha, beta, theta and delta waves with duration of on average 34 ± 12 s and 39 ± 23 s respectively. These birds may have been unconscious for 20 s or longer, according to the correlation dimension analyses. 3. The heart rate decreased significantly (P < 0·05) after stunning and recovered after 60 s. 4. Within a confidence limit of 95%, taking into account the number of animals with a reliable EEG, the chance of an effective stun of all broilers lies between 0·9 and 1·0 with a current of 70 mA (100 Hz for 1·5 s; n = 28) and with 100 mA (100 Hz for 1·5 s; n = 27). 5. The shear force of breast fillets was slightly lower (P < 0·01) 4 d post mortem compared with the conventional water bath stunned group (set at 100 mA, 100 Hz for 10 s). The percentage of fillets and legs without blood splashes was higher, and the percentage with severe blood splashes lower-to-none, for carcases stunned head-cloaca. 6. It can be concluded that broilers are effectively stunned with the head-cloaca method by using a controlled current of 70 mA or 100 mA for 1·5 s. The fillets and legs of bird stunned head-cloaca showed fewer blood splashes in the muscles compared with birds stunned in a conventional water bath. PMID:22646781

  3. Antagonistic regulation of swelling-activated Cl− current in rabbit ventricle by Src and EGFR protein tyrosine kinases

    Ren, Zuojun; Baumgarten, Clive M.

    2005-01-01

    Regulation of swelling-activated Cl− current (ICl,swell) is complex, and multiple signaling cascades are implicated. To determine whether protein tyrosine kinase (PTK) modulates ICl,swell and to identify the PTK involved, we studied the effects of a broad-spectrum PTK inhibitor (genistein), selective inhibitors of Src (PP2, a pyrazolopyrimidine) and epidermal growth factor receptor (EGFR) kinase (PD-153035), and a protein tyrosine phosphatase (PTP) inhibitor (orthovanadate). ICl,swell evoked ...

  4. Doubly Fed Induction Generator Based Wind Turbine Associated to a Shunt Active Power Filter for Current Harmonics Mitigation

    Samira Dib,

    2011-04-01

    Full Text Available Integration of wind turbine based on doubly fed induction generator (DFIG into the electrical grid has become an important part of electrical generation in many countries and its importance is continuing to increase. The advantages of using a DFIG instead of other generators are already well known. A few of them are variousspeed generations, the decoupled control of active and reactive power and high power capacity. However, the ever-growing proliferation of power electronics based devices for source conditioning and motion control in modern industrial applications has increased the occurrence of harmonic currents in distribution systems. This harmonics have harmful and costly effects on DFIG such as, the increase of stator and rotor core losses and the increase of the operating temperature. In this paper, a shunt active power filter (SAPF is proposed to mitigate current harmonics generated by nonlinear loads and keeps the current at the point of common coupling (PCC sinusoidal. The simulation results using MATLAB/SIMULINK show a good performance of the SAPF for current harmonics mitigation.

  5. The current state-of-the-art in active region seismology

    Moradi, H.

    2012-12-01

    Helioseismology is the study of the variations in the internal structure and properties of the dynamics of the Sun from measurements of its surface oscillations. With the 2010 launch of the Solar Dynamics Observatory (SDO) we are undoubtedly approaching a new dawn for local helioseismology, as the extent and quality of raw surface oscillation data has never been better. However, advances in theory and modelling are still required to fully utilise these data, especially in magnetic active regions and sunspots, where the physics is poorly understood.

  6. Optimized Laser Thermal Annealing on Germanium for High Dopant Activation and Low Leakage Current

    Shayesteh, Maryam; O' Connell, Dan; Gity, Farzan;

    2014-01-01

    In this paper, state-of-the-art laser thermal annealing is used to fabricate Ge diodes. We compared the effect of laser thermal annealing (LTA) and rapid thermal annealing (RTA) on dopant activation and electrical properties of phosphorus and Arsenic-doped n +/p junctions. Using LTA, high carrier...... implant conditions. On the other hand, RTA revealed very high I on/I off ratio ∼ 107 and n ∼ 1, at the cost of high dopant diffusion and lower carrier concentrations which would degrade scalability and access resistance....

  7. Observing Dynamics in Large-Scale Birkeland Currents with the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE)

    Anderson, B. J.; Korth, H.; Waters, C. L.; Barnes, R. J.; Olson, C.

    2015-12-01

    The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) provides continuous global observations of the magnetic perturbations that predominantly reflect Birkeland currents. The data are acquired by avionics magnetometers of the Iridium satellites and allow measurements from 66 satellites in near-polar circular, low altitude orbits. The configuration of the Iridium satellite constellation determines the longitude sampling spacing of ~ 2 hours and the re-sampling cadence of the system which is 9 minutes. From 2008 to 2013 the AMPERE system was developed which included new flight software on the Iridium satellites to allow telemetry of higher rate data to the ground and the Science Data Center to derive Birkeland current perturbations from the data and invert these signals to derive the global distributions of the currents using data windows of ten minutes. There were many challenges in developing AMPERE including automating inter-calibration between satellites and the baseline determination and removals. The results of AMPERE provide stunning confirmation of many of the statistical estimates for the distribution of currents but more significantly open a new window to understand their instantaneous distribution and dynamics. Examples of new features of the currents and their dynamics revealed by AMPERE are presented. In addition, prospects for new data products and increased data quality anticipated from AMPERE-NEXT to be implemented on the Iridium-NEXT generation of satellites are discussed.

  8. Working Group 1: Current plans of various organisations for lunar activities

    Balsiger, H.; Pilcher, C.

    1994-01-01

    Summaries of presentations by representatives of several space agencies and the International Academy of Astronautics concerning lunar activities are presented. Participating space agencies reported two different types of lunar planning, long term planning and scenarios and lunar missions competing within regular programs. The long term plans of the various agencies look remarkably similar. They all involve a phased approach (coincidentally all incorporating four phases) and all address three prime scientific elements: science of, on, and from the Moon. The missions under consideration by the second group of agencies could readily fit as elements in the longer term program. There is great interest in lunar astronomy. There is a great deal of potential infrastructure and lunar transport capability already available. There is also a wide range of interesting technological developments that could form part of a lunar program. A well concerted and coordinated international effort could lead to an affordable program. Recommendations are: an international conference on lunar exploration should be held every other year; an electronic network should be established for the daily exchange of information; and a mechanism should be established for regular working level coordination of activities.

  9. Current issues and related activities in seismic hazard analysis in Korea

    Seo, Jeong-Moon [Korea Atomic Energy Research Inst., Taejon (Korea, Republic of); Lee, Jong-Rim; Chang, Chun-Joong

    1997-03-01

    This paper discusses some technical issues identified from the seismic hazard analyses for probabilistic safety assessment on the operating Korean nuclear power plants and the related activities to resolve the issues. Since there are no strong instrumental earthquake records in Korea, the seismic hazard analysis is mainly dependent on the historical earthquake records. Results of the past seismic hazard analyses show that there are many uncertainties in attenuation function and intensity level and that there is a need to improve statistical method. The identification of the activity of the Yangsan Fault, which is close to nuclear power plant sites, has been an important issue. But the issue has not been resolved yet in spite of much research works done. Recently, some capable faults were found in the offshore area of Gulupdo Island in the Yellow Sea. It is anticipated that the results of research on both the Yangsan Fault and reduction of uncertainty in seismic hazard analysis will have an significant influence on seismic design and safety assessment of nuclear power plants in the future. (author)

  10. Direct-current Stimulation and Multi-electrode Array Recording of Seizure-like Activity in Mice Brain Slice Preparation.

    Lu, Hsiang-Chin; Chang, Wei-Jen; Chang, Wei-Pang; Shyu, Bai-Chuang

    2016-01-01

    Cathodal transcranial direct-current stimulation (tDCS) induces suppressive effects on drug-resistant seizures. To perform effective actions, the stimulation parameters (e.g., orientation, field strength, and stimulation duration) need to be examined in mice brain slice preparations. Testing and arranging the orientation of the electrode relative to the position of the mice brain slice are feasible. The present method preserves the thalamocingulate pathway to evaluate the effect of DCS on anterior cingulate cortex seizure-like activities. The results of the multichannel array recordings indicated that cathodal DCS significantly decreased the amplitude of the stimulation-evoked responses and duration of 4-aminopyridine and bicuculline-induced seizure-like activity. This study also found that cathodal DCS applications at 15 min caused long-term depression in the thalamocingulate pathway. The present study investigates the effects of DCS on thalamocingulate synaptic plasticity and acute seizure-like activities. The current procedure can test the optimal stimulation parameters including orientation, field strength, and stimulation duration in an in vitro mouse model. Also, the method can evaluate the effects of DCS on cortical seizure-like activities at both the cellular and network levels. PMID:27341682

  11. Strategic implications of the current surge of merger and alliance activity in the energy industry

    The transformation that has taken place in Canada's natural gas industry since the 1985 deregulation was reviewed. The 1985 'Halloween Agreement' was pivotal in deregulating the wholesale gas commodity business and paved the way for a truly competitive market for natural gas in Canada. Results of deregulation have been significantly lower prices for natural gas and a tripling of the natural gas market in Canada. Currently, natural gas represents 31 per cent of total energy consumption in Canada and approximately 22 per cent in the United States. New suppliers and industry players have entered the market to widen the choice and competition of energy products and services. Apart from the competition that resulted from deregulation, the convergence of the gas and electricity industries was considered to have been the most significant development. Ramifications of the gas-electricity convergence were reviewed. While the final outcome of the convergence in terms of the number and size of the companies operating in the market will not be known for some time, the de facto globalization of the natural gas business by reason of its interplay and offplay in regional markets with other forms of energy, is a well known fact. Further convergence, such as oil/natural gas/electricity was predicted

  12. Neutron Flux and Activation Calculations for a High Current Deuteron Accelerator

    Coniglio, Angela; Sandri, Sandro

    2005-01-01

    Neutron analysis of the first Neutral Beam (NB) for the International Thermonuclear Experimental Reactor (ITER) was performed to provide the basis for the study of the following main aspects: personnel safety during normal operation and maintenance, radiation shielding design, transportability of the NB components in the European countries. The first ITER NB is a medium energy light particle accelerator. In the scenario considered for the calculation the accelerated particles are negative deuterium ions with maximum energy of 1 MeV. The average beam current is 13.3 A. To assess neutron transport in the ITER NB structure a mathematical model of the components geometry was implemented into MCNP computer code (MCNP version 4c2. "Monte Carlo N-Particle Transport Code System." RSICC Computer Code Collection. June 2001). The neutron source definition was outlined considering both D-D and D-T neutron production. FISPACT code (R.A. Forrest, FISPACT-2003. EURATOM/UKAEA Fusion, December 2002) was used to assess neutron...

  13. Panel: Current Status of Knowledge and Recommendations for Further Related Activities

    This Panel consists of two parts, in the first part the participants attempt to summarise their views on the current status and knowledge of SFI and its importance for the LMFBR safety case and in the second part they try to agree on recommendations for future actions. The first question tackled was: what progress has been made since the Ispra meeting which was a little over two years ago - in answering the question: 'what role does SFI play in LMFBR safety'? The second question approached was: 'Is it possible to identify SFI areas which are not yet covered by the present research and development programme? Finally 4 recommendations were proposed: 1. to have another meeting of the same nature as this one and the previous ones in two years' time; 2. to create a group dealing with the fundamental science with a view to further the safety of the LMFBR. This group would meet more regularly and would not require, and that is the important thing, approval from-CSNI every time it meets; 3. to discontinue the group on calculational models; 4. to publish at least one to two newsletters between this SFI meeting and the next SFI meeting in two years

  14. Identification of Candidates for Active Surveillance: Should We Change the Current Paradigm?

    Alcover, Joan; Filella, Xavier

    2015-12-01

    Active surveillance (AS) has been claimed to avoid overtreatment of prostate cancer (PCa). It remains unclear which patients may benefit from AS. One way to clarify this is to improve the definition of insignificant PCa. PSA and Gleason score--the basic instruments used to select patients for AS--suffer from systematic errors. The nomograms used to define insignificant PCa are based on patients whose disease was classified before changes were introduced in the 2005 Consensus Conference on Gleason Grading; thus, the experience obtained cannot be directly applied to today's patients. Additionally, despite the standardization of prostate-specific antigen assays promoted by the World Health Organization, differences persist and could lead to misclassification of patients. These factors lead to an incorrect classification of patients into risk groups. Although new variables would increase risk group classification, the necessary first step is to optimize the use of both prostate-specific antigen serum levels and Gleason score. PMID:26194410

  15. In vitro - in vivo correlations for endocrine activity of a mixture of currently used pesticides

    Taxvig, Camilla; Hadrup, Niels; Boberg, Julie; Petersen, Marta Axelstad; Bossi, Rossana; Bonefeld-Jørgensen, Eva Cecilie; Vinggaard, Anne Marie

    2013-01-01

    Two pesticide mixtures were investigated for potential endocrine activity. Mix 3 consisted of bitertanol, propiconazole, and cypermethrin, and Mix 5 included malathion and terbuthylazine in addition to the three pesticides in Mix 3.All five single pesticides and the two mixtures were investigated...... for their ability to affect steroidogenesis in vitro in H295R cells. The pesticides alone and both mixtures affected steroidogenesis with both mixtures causing increase in progesterone and decrease in testosterone. For Mix 5 an increase in estradiol was seen as well, indicating increased aromatase...... in Mix 5. However, the hormonal responses in vitro were only partly reflected in vivo, probably due to some toxicokinetic issues, as the pesticide levels in the amniotic fluid also were found to be negatively affected by the number of compounds present in the mixtures. Nonetheless, the H295R assay...

  16. Review of dismantling activities in Europe and worldwide: Current state and perspectives

    This analysis adopts deliberately the point of view of 'dismantling companies' and aims to draw up a coherent overview of the presentations made per country or major contractors. Aside from the programs, or intentions, that may have been published, its goal is to take stock of the actions undertaken in the last few years and the significant changes that have been observed. In view of the diversity of the 'business models', depending on whether research institutes, major electrical power companies or industrial companies in charge of fuel-related activities are involved, the objective of this presentation is also to assess the solutions retained on both a technical and industrial level for the entire 'de-construction sector'. In conclusion, this presentation seeks to highlight the major challenges that open dismantling industry will have to meet. (author)

  17. Current states for developing the prompt gamma neutron activation analysis system at HANARO

    Fabrication and performance test of major components used for the Prompt Gamma Neutron Activation Analysis system at HANARO have been completed. Thermal neutron extraction device consists of pyrolytic graphite crystals and a manual type two-axis goniometer. To focus neutron at the sample position graphite crystals can be tilted to concave mirror type. The tilting angle corresponding to the focusing condition was determined by reflecting parallel light. Collimator is composed of alternating layers of borated plastic, lead and polyethylene. As a shield surrounding collimator, heavy concrete mixed with B4C power was fabricated and neutron and gamma-ray shields for diffracted beam line have been completed. Presently, measurements of diffracted beam characteristics and neutron focusing effect are on the way with graphite crystals, collimator and surrounding shield installed

  18. Activity-Based Costing for Pathology Examinations and Comparison with the Current Pricing System in Turkey

    Ferda AK ERGÜN

    2013-01-01

    Full Text Available Objective: To demonstrate the real cost data of the pathology examinations by using the activity-based costing method and to contribute to the financial planning of the departments, health managers and also the social security institution.Material and Method: Forty-four examinations selected from the Healthcare Implementation Notification system list and performed at the Ankara University Faculty of Medicine Pathology Department during September 2010 were studied. The analysis and the real cost calculations were done according to the duration of the procedures. Calculated costs were compared with the Healthcare Implementation Notification system and Medicare price lists.Results: The costs of the pathology tests listed within the same pricing levels in the Healthcare Implementation Notification system list showed great differences. The minimum and maximum costs in level 1, 2, 3, and 4 were 15,98-80,15 TL, 15,95-258,59 TL, 42,38- 236,87 TL, and 124,42-406,76 TL, respectively. Medicare price levels were more consistent with the real costs of the examinations compared to the Healthcare Implementation Notification system price list.Conclusion: The prices of the pathology examination listed at different levels in the Healthcare Implementation Notification system lists do not cover the real costs of the work done. The principal parameters of Activity-Based Costing system are more suitable for making the most realistic cost categorization. Although the prices could differ between countries, the Medicare system categories are more realistic than the Healthcare Implementation Notification system. The Healthcare Implementation Notification system list needs to be revised in order to reflect the real costs of the pathology examinations.

  19. Current Activities of the Ministry of Mines, Islamic Republic of Afghanistan

    Adel, M.

    2008-12-01

    Beginning in late 2001, the Afghanistan government started developing plans for the revitalization of the Natural Resources sector. This revitalization included the rebuilding and reorganization of the capabilities of the Ministry of Mines and Industries (now the Ministry of Mines) and the Afghan Geological Survey and several other Afghan ministries. The initial focus was on the development of new mining and hydrocarbon laws, which were supported by the World Bank. Concurrent with these activities was the recognized need to identify, organize and compile existing data and information on the natural resources of the country. This has been followed by the use of these data and information to provide preliminary assessments of the oil and gas resources, mineral resources, water resources, coal resources, and earthquake hazards, all based on existing data. A large part of these assessment efforts required the development of a geospatial infrastructure through the use of satellite imagery and other remote sensing technologies. Institutional and capacity building were integral parts of all efforts. With the assessment and law activities ongoing, the Ministry of Mine has now turned to the development of a leasing framework, which address the critical need of transparency of leasing, lease management, and royalty collection. This new leasing system was implemented in spring 2008 with the leasing of the Aynak Copper Deposit, which is located about 25 miles south of Kabul. At the moment, a second world class mineral deposit is being considered for leasing within the next year. Oil and gas lease tracts are also under development in the northern oil and gas basins of Afghanistan. With the support of the Afghan government, the U.S. Geological Survey (USGS) has recently completed the gathering of new data and information in support of the Natural Resources Sector. These data gathering missions include gravity, magnetics, radar, and hyperspectral data, which were gathered through

  20. Characterization of low latitude GPS-TEC during current low solar activity phase and implications

    Complete text of publication follows. The low latitude ionosphere exhibits several variabilities such as diurnal, 27 days solar rotation, seasonal, annual, and solar cycle dependent variation. Apart from these, the atmosphere-ionosphere interaction is also responsible for dynamics and variability of electron density in different ionospheric regions. Total electron content (TEC) is an important parameter for characterization and modeling of low latitude ionosphere. GPS has provided us with an opportunity to study the ionosphere with better spatial and temporal resolution and coverage. The crest of equatorial ionization anomaly (EIA) exhibits maximum variability during quiet periods all over the globe. We analyze and present four years of GPS-TEC data from October, 2004 to October, 2008 recorded at Udaipur, near the crest of EIA in India, using a GPS receiver GSV4004A. The data has been analyzed only for the geomagnetically quiet periods and the results have been presented in terms of variation in the location of the EIA crest in Indian zone, from year 2004 to 2008 during decreasing solar activity and in terms of diurnal, monthly, seasonal and solar flux variation of low latitude TEC. Our study suggests that the crest of EIA has shifted equatorward with the declining solar activity. Substantial shift in the crest of EIA has important implications for systems like SBAS for GPS positioning, which use TEC models. Also, it indicates the variability in EEJ. From the statistical analysis of the data, it is found that the variation in TEC shows good correlation with solar 10.7 cm flux for the concerned period.

  1. Current activities and challenges of the European network for inspection and qualification (ENIQ)

    Martin, Oliver [European Commission, Joint Research Centre (JRC), Petten (Netherlands). Institute for Energy and Transport (IET); Martin, Etienne [EDF, St Denis (France). Direction Production Ingenierie; Booler, Russ [AMEC Clean Energy Europe, Warrington (United Kingdom); Zetterwall, Tommy [Swedish Qualification Centre, Taeby (Sweden); Walker, Tony [Rolls-Royce Submarines, Derby (United Kingdom)

    2014-10-15

    This article describes the development of the European Network for Inspection and Qualification (ENIQ) since the previous presentation of the network in the 2011 April/May edition of this journal, covering mainly the new technical challenges facing the network and resulting projects as well as the establishment of the new Task Group for Inspection Qualification Bodies. ENIQ is a utility-driven network dealing with the reliability and effectiveness of non-destructive testing (NDT) for nuclear power plants (NPP). ENIQ is recognised as one of the main contributors to today's global qualification codes and guidelines for in-service inspection (ISI) and has published nearly 50 documents. Among them are the 'European Methodology for Qualification of Non-Destructive Testing', the first qualification methodology based on technical justifications, the 'European Framework Document for Risk-Informed In-Service Inspection (RI-ISI)', and various recommend practices. In addition ENIQ has carried out two pilot studies and a number of surveys. In 2012, ENIQ joined the European based R and D association on Gen II and III reactors, NUGENIA, making ENIQ its 8{sup th} technical area. Following the entry into NUGENIA, ENIQ members have updated the ENIQ roadmap and included a number of new technical challenges facing its members in the near future. Also ENIQ established a third task group in 2013, the Task Group for Inspection Qualification Bodies (TGIQB), which should serve as an exchange forum for inspection qualification bodies. ENIQ is currently preparing or performing new projects and studies to tackle these challenges and new recommended practices and reports are likely to evolve from these projects, which will enable ENIQ to maintain its role as one of the main contributors to today's global qualification codes and guidelines for ISI.

  2. Ocean Science for Decision-Making: Current Activities of the National Research Council's Ocean Studies Board

    Roberts, S.; Glickson, D.; Mengelt, C.; Forrest, S.; Waddell, K.

    2012-12-01

    The National Research Council is a private, nonprofit organization chartered by Congress in 1916 as an expansion of the U.S. National Academy of Sciences. Its mission is to improve the use of science in government decision making and public policy, increase public understanding, and promote the acquisition and dissemination of knowledge in matters involving science, engineering, technology, and health. Within the National Research Council, the Ocean Studies Board (OSB) mission is to explore the science, policies, and infrastructure needed to understand, manage, and conserve coastal and marine environments and resources. OSB undertakes studies and workshops on emerging scientific and policy issues at the request of federal agencies, Congress, and others; provides program reviews and guidance; and facilitates communication on oceanographic issues among different sectors. OSB also serves as the U.S. National Committee to the international, nongovernmental Scientific Committee on Oceanic Research (SCOR). OSB has produced reports on a wide range of topics of interest to researchers and educators, the federal government, the non-profit sector, and industry. Recent reports have focused on ecosystem services in the Gulf of Mexico after the Deepwater Horizon oil spill, sea level rise on the U.S. west coast, scientific ocean drilling needs and accomplishments, requirements for sustained ocean color measurements, critical infrastructure for ocean research, tsunami warning and preparedness, ocean acidification, and marine and hydrokinetic power resource assessments. Studies that are currently underway include responding to oil spills in the Arctic, evaluating the effectiveness of fishery stock rebuilding plans, and reviewing the National Ocean Acidification Research Plan. OSB plays an important role in helping create policy decisions and disseminating important information regarding various aspects of ocean science.

  3. Currently used pesticides and their mixtures affect the function of sex hormone receptors and aromatase enzyme activity

    Kjeldsen, Lisbeth Stigaard; Ghisari, Mandana; Bonefeld-Jørgensen, Eva Cecilie, E-mail: ebj@mil.au.dk

    2013-10-15

    The endocrine-disrupting potential of pesticides is of health concern, since they are found ubiquitously in the environment and in food items. We investigated in vitro effects on estrogen receptor (ER) and androgen receptor (AR) transactivity, and aromatase enzyme activity, of the following pesticides: 2-methyl-4-chlorophenoxyacetic acid (MCPA), terbuthylazine, iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulfuron-methyl, chlormequat chloride, bitertanol, propiconazole, prothioconazole, mancozeb, cypermethrin, tau fluvalinate, malathion and the metabolite ethylene thiourea (ETU). The pesticides were analyzed alone and in selected mixtures. Effects of the pesticides on ER and AR function were assessed in human breast carcinoma MVLN cells and hamster ovary CHO-K1 cells, respectively, using luciferase reporter gene assays. Effects on aromatase enzyme activity were analyzed in human choriocarcinoma JEG-3 cells, employing the classical [{sup 3}H]{sub 2}O method. Five pesticides (terbuthylazine, propiconazole, prothioconazole, cypermethrin and malathion) weakly induced the ER transactivity, and three pesticides (bitertanol, propiconazole and mancozeb) antagonized the AR activity in a concentration-dependent manner. Three pesticides (terbuthylazine, propiconazole and prothioconazole) weakly induced the aromatase activity. In addition, two mixtures, consisting of three pesticides (bitertanol, propiconazole, cypermethrin) and five pesticides (terbuthylazine, bitertanol, propiconazole, cypermethrin, malathion), respectively, induced the ER transactivity and aromatase activity, and additively antagonized the AR transactivity. In conclusion, our data suggest that currently used pesticides possess endocrine-disrupting potential in vitro which can be mediated via ER, AR and aromatase activities. The observed mixture effects emphasize the importance of considering the combined action of pesticides in order to assure proper estimations of related health effect risks

  4. Currently used pesticides and their mixtures affect the function of sex hormone receptors and aromatase enzyme activity

    The endocrine-disrupting potential of pesticides is of health concern, since they are found ubiquitously in the environment and in food items. We investigated in vitro effects on estrogen receptor (ER) and androgen receptor (AR) transactivity, and aromatase enzyme activity, of the following pesticides: 2-methyl-4-chlorophenoxyacetic acid (MCPA), terbuthylazine, iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulfuron-methyl, chlormequat chloride, bitertanol, propiconazole, prothioconazole, mancozeb, cypermethrin, tau fluvalinate, malathion and the metabolite ethylene thiourea (ETU). The pesticides were analyzed alone and in selected mixtures. Effects of the pesticides on ER and AR function were assessed in human breast carcinoma MVLN cells and hamster ovary CHO-K1 cells, respectively, using luciferase reporter gene assays. Effects on aromatase enzyme activity were analyzed in human choriocarcinoma JEG-3 cells, employing the classical [3H]2O method. Five pesticides (terbuthylazine, propiconazole, prothioconazole, cypermethrin and malathion) weakly induced the ER transactivity, and three pesticides (bitertanol, propiconazole and mancozeb) antagonized the AR activity in a concentration-dependent manner. Three pesticides (terbuthylazine, propiconazole and prothioconazole) weakly induced the aromatase activity. In addition, two mixtures, consisting of three pesticides (bitertanol, propiconazole, cypermethrin) and five pesticides (terbuthylazine, bitertanol, propiconazole, cypermethrin, malathion), respectively, induced the ER transactivity and aromatase activity, and additively antagonized the AR transactivity. In conclusion, our data suggest that currently used pesticides possess endocrine-disrupting potential in vitro which can be mediated via ER, AR and aromatase activities. The observed mixture effects emphasize the importance of considering the combined action of pesticides in order to assure proper estimations of related health effect risks. - Highlights:

  5. Ethanol inhibition of N-methyl-D-aspartate-activated current in mouse hippocampal neurones: whole-cell patch-clamp analysis

    Peoples, Robert W.; White, Geoffrey; Lovinger, David M.; Weight, Forrest F

    1997-01-01

    The action of ethanol on N-methyl-D-aspartate (NMDA)-activated ion current was studied in mouse hippocampal neurones in culture using whole-cell patch-clamp recording.Ethanol inhibited NMDA-activated current in a voltage-independent manner, and did not alter the reversal potential of NMDA-activated current.Concentration–response analysis of NMDA- and glycine-activated current revealed that ethanol decreased the maximal response to both agonists without affecting their EC50 values.The polyamin...

  6. Role of arachidonic acid in hyposmotic membrane stretch-induced increase in calcium-activated potassium currents in gastric myocytes

    Meng YANG; Wen-xie XU; Xing-lan LI; Hui-ying XU; Jia-bin SUN; Bin MEI; Hai-feng ZHENG; Lian-hua PIAO; De-gang XING; Zhai-liu LI

    2005-01-01

    Aim: To study effects of arachidonic acid (AA) and its metabolites on the hyposmotic membrane stretch-induced increase in calcium-activated potassium currents (IKCa) in gastric myocytes. Methods: Membrane currents were recorded by using a conventional whole cell patch-clamp technique in gastric myocytes isolated with collagenase. Results: Hyposmotic membrane stretch and AA increased both IK(Ca) and spontaneous transient outward currents significantly.Exogenous AA could potentiate the hyposmotic membrane stretch-induced increase in IK(Ca). The hyposmotic membrane stretch-induced increase in IK(Ca) was significantly suppressed by dimethyleicosadienoic acid (100 μmol/L in pipette solution), an inhibitor of phospholipase A2. Nordihydroguaiaretic acid, a lipoxygenase inhibitor, significantly suppressed AA and hyposmotic membrane stretch-induced increases in IK(Ca). External calcium-free or gadolinium chloride, a blocker of stretch-activated channels, blocked the AA-induced increase in IK(Ca) significantly, but it was not blocked by nicardipine, an L-type calcium channel blocker. Ryanodine, a calcium-induced calcium release agonist, completely blocked the AA-induced increase in IK(Ca); however, heparin, a potent inhibitor of inositol triphosphate receptor, did not block the AA-induced increase in IK(Ca). Conclusion:Hyposmotic membrane stretch may activate phospholipase A2, which hydrolyzes membrane phospholipids to ultimately produce AA; AA as a second messenger mediates Ca2+ influx, which triggers Ca2+-induced Ca2+ release and elicits activation of IK(Ca) in gastric antral circular myocytes of the guinea pig.

  7. Disrupted coupling of gating charge displacement to Na+ current activation for DIIS4 mutations in hypokalemic periodic paralysis.

    Mi, Wentao; Rybalchenko, Volodymyr; Cannon, Stephen C

    2014-08-01

    Missense mutations at arginine residues in the S4 voltage-sensor domains of NaV1.4 are an established cause of hypokalemic periodic paralysis, an inherited disorder of skeletal muscle involving recurrent episodes of weakness in conjunction with low serum K(+). Expression studies in oocytes have revealed anomalous, hyperpolarization-activated gating pore currents in mutant channels. This aberrant gating pore conductance creates a small inward current at the resting potential that is thought to contribute to susceptibility to depolarization in low K(+) during attacks of weakness. A critical component of this hypothesis is the magnitude of the gating pore conductance relative to other conductances that are active at the resting potential in mammalian muscle: large enough to favor episodes of paradoxical depolarization in low K(+), yet not so large as to permanently depolarize the fiber. To improve the estimate of the specific conductance for the gating pore in affected muscle, we sequentially measured Na(+) current through the channel pore, gating pore current, and gating charge displacement in oocytes expressing R669H, R672G, or wild-type NaV1.4 channels. The relative conductance of the gating pore to that of the pore domain pathway for Na(+) was 0.03%, which implies a specific conductance in muscle from heterozygous patients of ∼ 10 µS/cm(2) or 1% of the total resting conductance. Unexpectedly, our data also revealed a substantial decoupling between gating charge displacement and peak Na(+) current for both R669H and R672G mutant channels. This decoupling predicts a reduced Na(+) current density in affected muscle, consistent with the observations that the maximal dV/dt and peak amplitude of the action potential are reduced in fibers from patients with R672G and in a knock-in mouse model of R669H. The defective coupling between gating charge displacement and channel activation identifies a previously unappreciated mechanism that contributes to the reduced

  8. Substantial depletion of the intracellular Ca2+ stores is required for macroscopic activation of the Ca2+ release-activated Ca2+ current in rat basophilic leukaemia cells.

    Fierro, L; Parekh, A B

    2000-01-15

    1. Tight-seal whole-cell patch clamp experiments were performed to examine the ability of different intracellular Ca2+ mobilising agents to activate the Ca2+ release-activated Ca2+ current (ICRAC) in rat basophilic leukaemia (RBL-1) cells under conditions of weak cytoplasmic Ca2+ buffering. 2. Dialysis with a maximal concentration of inositol 1,4,5-trisphosphate (IP3) routinely failed to activate macroscopic ICRAC in low buffer (0.mM EGTA, BAPTA or dimethyl BAPTA), whereas it activated the current to its maximal extent in high buffer (10 mM EGTA). Dialysis with a poorly metabolisable analogue of IP3, with ionomycin, or with IP3 and ionomycin all failed to generate macroscopic ICRAC in low Ca2+ buffering conditions. 3. Dialysis with the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pump blocker thapsigargin was able to activate ICRAC even in the presence of low cytoplasmic Ca2+ buffering, albeit at a slow rate. Exposure to IP3 together with the SERCA blockers thapsigargin, thapsigargicin or cyclopiazonic acid rapidly activated ICRAC in low buffer. 4. Following activation of ICRAC by intracellular dialysis with IP3 and thapsigargin in low buffer, the current was very selective for Ca2+ (apparent KD of 1 mM) Sr2+ and Ba2+ were less effective charge carriers and Na+ was not conducted to any appreciable extent. The ionic selectivity of ICRAC was very similar in low or high intracellular Ca2+ buffer. 5. Fast Ca2+-dependent inactivation of ICRAC occurred at a similar rate and to a similar extent in low or high Ca2+ buffer. Ca2+-dependent inactivation is not the reason why macroscopic ICRAC cannot be seen under conditions of low cytoplasmic Ca2+ buffering. 6. ICRAC could be activated by combining IP3 with thapsigargin, even in the presence of 100 microM Ca2+ and the absence of any exogenous Ca2+ chelator, where ATP and glutamate represented the only Ca2+ buffers in the pipette solution. 7. Our results suggest that a threshold exists within the IP3-sensitive Ca2+ store

  9. Current issues in the X-ray properties of active galactic nuclei

    Some issues raised by soft X-ray spectra and hours variability observations of active galactic nuclei (AGN), made possible by improved energy calibration of the Einstein IPC and the launch of Exosat into a unique 72-hour highly elliptical orbit, are presented. Explanations for steep soft excesses in quasars include the emission from the hot tail of an accretion disk spectrum, and from optically thin bremsstrahlung at 1-2 x 10 to the 6th K from a large volume. Mechanisms for the approximately 1.0 slope in the 0.2-4 keV soft IPC X-ray band quasars include direct synchrotron emission, unsaturated Comptonization of an arbitrary seed spectrum, and synchro-Compton scattering from the infrared. The Exosat observation of NGC 4051 revealed six 1-hour cycles with spectral changes during the variations. AGN time variations may now be able to limit emission models through studying, for example, the lag times between soft and hard variations. 47 references

  10. Forum for Arctic Modeling and Observational Synthesis (FAMOS): Past, current, and future activities

    Proshutinsky, A.; Steele, M.; Timmermans, M.-L.

    2016-06-01

    The overall goal of the Forum for Arctic Modeling and Observational Synthesis (FAMOS) community activities reported in this special issue is to enhance understanding of processes and mechanisms driving Arctic Ocean marine and sea ice changes, and the consequences of those changes especially in biogeochemical and ecosystem studies. Major 2013-2015 FAMOS accomplishments to date are: identification of consistent errors across Arctic regional models; approaches to reduce these errors, and recommendations for the most effective coupled sea ice-ocean models for use in fully coupled regional and global climate models. 2013-2015 FAMOS coordinated analyses include many process studies, using models together with observations to investigate: dynamics and mechanisms responsible for drift, deformation and thermodynamics of sea ice; pathways and mechanisms driving variability of the Atlantic, Pacific and river waters in the Arctic Ocean; processes of freshwater accumulation and release in the Beaufort Gyre; the fate of melt water from Greenland; characteristics of ocean eddies; biogeochemistry and ecosystem processes and change, climate variability, and predictability. Future FAMOS collaborations will focus on employing models and conducting observations at high and very high spatial and temporal resolution to investigate the role of subgrid-scale processes in regional Arctic Ocean and coupled ice-ocean and atmosphere-ice-ocean models.

  11. Current Status of Trace Metal Pollution in Soils Affected by Industrial Activities

    Ehsanul Kabir

    2012-01-01

    Full Text Available There is a growing public concern over the potential accumulation of heavy metals in soil, owing to rapid industrial development. In an effort to describe the status of the pollutions of soil by industrial activities, relevant data sets reported by many studies were surveyed and reviewed. The results of our analysis indicate that soils were polluted most significantly by metals such as lead, zinc, copper, and cadmium. If the dominant species are evaluated by the highest mean concentration observed for different industry types, the results were grouped into Pb, Zn, Ni, Cu, Fe, and As in smelting and metal production industries, Mn and Cd in the textile industry, and Cr in the leather industry. In most cases, metal levels in the studied areas were found to exceed the common regulation guideline levels enforced by many countries. The geoaccumulation index (Igeo, calculated to estimate the enrichment of metal concentrations in soil, showed that the level of metal pollution in most surveyed areas is significant, especially for Pb and Cd. It is thus important to keep systematic and continuous monitoring of heavy metals and their derivatives to manage and suppress such pollution.

  12. Geological fieldwork 1999 : a summary of field activities and current research. 25 ed.

    NONE

    2000-01-01

    This document presents a report of activities and projects carried out in 1999 by the British Columbia Geological Survey (GSB). It also includes contributions by associated earth scientists in British Columbia. Highlights include: initiation of the Ancient Pacific Margin NATMAP project for mineral deposit studies, identification of regions with potential for plutonic-related gold deposits, a project for identifying the control on volcanogenic massive sulphide (VMS) mineralization, an innovative assessment to identify potential copper or gold-rich iron oxide deposits, coal quality and washability studies to understand the nature of coal deposits, gemstone potential and mineral occurrences within the province. Geoscience databases are continually being upgraded by the GSB for mineral occurrences (MINFILE), assessment report files, and regional geochemical samples. In addition, the GSB audits digital terrain data submitted by forest companies and makes this information available over the Internet as terrain and soil maps are used on a regular basis in mineral exploration as an aid in geochemical surveys. refs., tabs., figs.

  13. Leptospirosis--current risk factors connected with human activity and the environment.

    Wasiński, Bernard; Dutkiewicz, Jacek

    2013-01-01

    Leptospirosis is a widespread although recently neglected zoonosis recognized worldwide. The disease seems to be underestimated, especially in countries located in the temperate climatic zone. The presented article concerns the main characteristics of leptospirosis and describes formerly known and recently observed environmental, occupational and recreational risk factors significant in the spreading and pathogenesis of the disease. The aspects of epidemiology significant in the temperate climatic zone are emphasized. The majority of cited articles present cases of the disease reported from Europe or North America. Climatic changes (warming) and extreme weather events such as floods are potential risk factors of leptospirosis. Also, some socio-economic phenomena, such as the intensive migration of people resulting in the transfer of the infections acquired in tropical countries, or worsening of economic status in the cities, increase the probability of disease. Apart from the danger connected with rodents, which are the main vectors of leptospires, occurrence of the disease in dogs and cats can generate a higher risk of infection for humans. Infections may also be acquired during various types of agricultural work and during recreational activities, such as swimming. The results of recent investigations show that ticks are also potential vectors of leptospires. The more frequent emergence of leptospirosis in countries located in the temperate climatic zone emphasize the need to verify knowledge related to the risk of its appearance, and to consider this disease during diagnostic processes. PMID:23772568

  14. Current activities of chemical applications of Tsing Hua Open-pool Reactor

    Tsing Hua Open-pool Reactor (THOR) is a swiming pool type research reactor operated and maintained by the University. The functions of THOR are two folds, i.e. (1) teaching and training of nuclear scientists and engineers, and (2) promotion of peaceful uses of atomic energy in Taiwan. Thus, besides the educational program THOR has been offering neutron irradiation service on regular schedule (30 hrs. per week full power operation at 1 MW with neutron flux of ca. 2 x 1012 n cm-2 sec.-1 since 1963). Among many other projects chemical application of THOR has been one of the important program implimented in early days. Following two projects have been set up with rather limited budget: (1) Production and supply of short-lived radioisotopes (both general purpose and medical use) for domestic use. (2) Application of neutron activation analysis in the fields of environmental, geological, biological and material science. It turned out that quite fruitful results have been obtained. It is the purpose of this paper to describe in detail some of the characteristic aspects on the utilization of THOR in the field of chemical application. (author)

  15. A Simple Assay to Screen Antimicrobial Compounds Potentiating the Activity of Current Antibiotics

    Iqbal, Junaid; Kazmi, Shahana Urooj; Khan, Naveed Ahmed

    2013-01-01

    Antibiotic resistance continues to pose a significant problem in the management of bacterial infections, despite advances in antimicrobial chemotherapy and supportive care. Here, we suggest a simple, inexpensive, and easy-to-perform assay to screen antimicrobial compounds from natural products or synthetic chemical libraries for their potential to work in tandem with the available antibiotics against multiple drug-resistant bacteria. The aqueous extract of Juglans regia tree bark was tested against representative multiple drug-resistant bacteria in the aforementioned assay to determine whether it potentiates the activity of selected antibiotics. The aqueous extract of J. regia bark was added to Mueller-Hinton agar, followed by a lawn of multiple drug-resistant bacteria, Salmonella typhi or enteropathogenic E. coli. Next, filter paper discs impregnated with different classes of antibiotics were placed on the agar surface. Bacteria incubated with extract or antibiotics alone were used as controls. The results showed a significant increase (>30%) in the zone of inhibition around the aztreonam, cefuroxime, and ampicillin discs compared with bacteria incubated with the antibiotics/extract alone. In conclusion, our assay is able to detect either synergistic or additive action of J. regia extract against multiple drug-resistant bacteria when tested with a range of antibiotics. PMID:23865073

  16. A Simple Assay to Screen Antimicrobial Compounds Potentiating the Activity of Current Antibiotics

    Junaid Iqbal

    2013-01-01

    Full Text Available Antibiotic resistance continues to pose a significant problem in the management of bacterial infections, despite advances in antimicrobial chemotherapy and supportive care. Here, we suggest a simple, inexpensive, and easy-to-perform assay to screen antimicrobial compounds from natural products or synthetic chemical libraries for their potential to work in tandem with the available antibiotics against multiple drug-resistant bacteria. The aqueous extract of Juglans regia tree bark was tested against representative multiple drug-resistant bacteria in the aforementioned assay to determine whether it potentiates the activity of selected antibiotics. The aqueous extract of J. regia bark was added to Mueller-Hinton agar, followed by a lawn of multiple drug-resistant bacteria, Salmonella typhi or enteropathogenic E. coli. Next, filter paper discs impregnated with different classes of antibiotics were placed on the agar surface. Bacteria incubated with extract or antibiotics alone were used as controls. The results showed a significant increase (>30% in the zone of inhibition around the aztreonam, cefuroxime, and ampicillin discs compared with bacteria incubated with the antibiotics/extract alone. In conclusion, our assay is able to detect either synergistic or additive action of J. regia extract against multiple drug-resistant bacteria when tested with a range of antibiotics.

  17. Control of plasma properties in a short direct current glow discharge with active boundaries

    Demidov, Vladimir; Adams, Steven; Bogdanov, Yevgeny; Koepke, Mark; Kudryavtsev, Anatoly; Kurlyandskaya, Iya

    2015-11-01

    To demonstrate controlling electron and metastable density ratio and electron temperature by applying negative voltages to the active (conducting) discharge wall in a low-pressure plasma with nonlocal electron energy distribution function, modeling has been performed in a short (without positive column) dc glow discharge with a cold cathode. The applied negative voltage can modify trapping the low-energy part of the energetic electrons emitted from the cathode sheath and arising from the atomic and molecular processes in the plasma within the device volume. Those electrons are responsible for heating the slow, thermal electrons, while production of slow electrons (ions) and metastable atoms is mostly due to energetic electrons with higher energies. Increasing electron temperature results in increasing decay rate of slow, thermal electrons, while decay rate of metastable atoms and production rates of slow electrons and metastable atoms practically are unchanged. The result is in variation of electron and metastable density ratio and electron temperature with variation of the wall negative voltage. A part of this research was performed, while one of the authors (VID) held a National Research Council Research Associateship Award at AFRL. The work was also partially supported by SPbGU (Grant No. 11.38.658.2013) and ITMO University (Grant No. 713577).

  18. Current practice of public involvement activities in biomedical research and innovation: a systematic qualitative review.

    Jonas Lander

    Full Text Available BACKGROUND: A recent report from the British Nuffield Council on Bioethics associated 'emerging biotechnologies' with a threefold challenge: 1 uncertainty about outcomes, 2 diverse public views on the values and implications attached to biotechnologies and 3 the possibility of creating radical changes regarding societal relations and practices. To address these challenges, leading international institutions stress the need for public involvement activities (PIAs. The objective of this study was to assess the state of PIA reports in the field of biomedical research. METHODS: PIA reports were identified via a systematic literature search. Thematic text analysis was employed for data extraction. RESULTS: After filtering, 35 public consultation and 11 public participation studies were included in this review. Analysis and synthesis of all 46 PIA studies resulted in 6 distinguishable PIA objectives and 37 corresponding PIA methods. Reports of outcome translation and PIA evaluation were found in 9 and 10 studies respectively (20% and 22%. The paper presents qualitative details. DISCUSSION: The state of PIAs on biomedical research and innovation is characterized by a broad range of methods and awkward variation in the wording of objectives. Better comparability of PIAs might improve the translation of PIA findings into further policy development. PIA-specific reporting guidelines would help in this regard. The modest level of translation efforts is another pointer to the "deliberation to policy gap". The results of this review could inform the design of new PIAs and future efforts to improve PIA comparability and outcome translation.

  19. Applying quantitative structure–activity relationship approaches to nanotoxicology: Current status and future potential

    The potential (eco)toxicological hazard posed by engineered nanoparticles is a major scientific and societal concern since several industrial sectors (e.g. electronics, biomedicine, and cosmetics) are exploiting the innovative properties of nanostructures resulting in their large-scale production. Many consumer products contain nanomaterials and, given their complex life-cycle, it is essential to anticipate their (eco)toxicological properties in a fast and inexpensive way in order to mitigate adverse effects on human health and the environment. In this context, the application of the structure–toxicity paradigm to nanomaterials represents a promising approach. Indeed, according to this paradigm, it is possible to predict toxicological effects induced by chemicals on the basis of their structural similarity with chemicals for which toxicological endpoints have been previously measured. These structure–toxicity relationships can be quantitative or qualitative in nature and they can predict toxicological effects directly from the physicochemical properties of the entities (e.g. nanoparticles) of interest. Therefore, this approach can aid in prioritizing resources in toxicological investigations while reducing the ethical and monetary costs that are related to animal testing. The purpose of this review is to provide a summary of recent key advances in the field of QSAR modelling of nanomaterial toxicity, to identify the major gaps in research required to accelerate the use of quantitative structure–activity relationship (QSAR) methods, and to provide a roadmap for future research needed to achieve QSAR models useful for regulatory purposes

  20. On the Current Solar Magnetic Activity in the Light of Its Behaviour During the Holocene

    Inceoglu, F.; Simoniello, R.; Knudsen, M. F.; Karoff, C.; Olsen, J.; Turck-Chièze, S.

    2016-01-01

    Solar modulation potential (SMP) reconstructions based on cosmogenic nuclide records reflect changes in the open solar magnetic field and can therefore help us obtain information on the behaviour of the open solar magnetic field over the Holocene period. We aim at comparing the Sun's large-scale magnetic field behaviour over the last three solar cycles with variations in the SMP reconstruction through the Holocene epoch. To achieve these objectives, we use the IntCal13 14C data to investigate distinct patterns in the occurrences of grand minima and maxima during the Holocene period. We then check whether these patterns might mimic the recent solar magnetic activity by investigating the evolution of the energy in the Sun's large-scale dipolar magnetic field using the Wilcox Solar Observatory data. The cosmogenic radionuclide data analysis shows that {≈} 71 % of grand maxima during the period from 6600 BC to 1650 AD were followed by a grand minimum. The characteristics of the occurrences of grand maxima and minima are consistent with the scenario in which the dynamical non-linearity induced by the Lorentz force leads the Sun to act as a relaxation oscillator. This finding implies that the probability for these events to occur is non-uniformly distributed in time, as there is a memory in their driving mechanism, which can be identified via the back-reaction of the Lorentz force.

  1. On the current solar magnetic activity in the light of its behaviour during the Holocene

    Inceoglu, F; Knudsen, M F; Karoff, C; Olsen, J; Turck-Chièze, S

    2015-01-01

    Solar modulation potential (SMP) reconstructions based on cosmogenic nuclide records reflect changes in the open solar magnetic field and can therefore help us obtain information on the behaviour of the open solar magnetic field over the Holocene period. We aim at comparing the Sun's large-scale magnetic field behaviour over the last three solar cycles with variations in the SMP reconstruction through the Holocene epoch. To achieve these objectives, we use the IntCal13 $^{14}$C data to investigate distinct patterns in the occurrences of grand minima and maxima during the Holocene period. We then check whether these patterns might mimic the recent solar magnetic activity by investigating the evolution of the energy in the Sun's large-scale dipolar magnetic field using the Wilcox Solar Observatory data. The cosmogenic radionuclide data analysis shows that $\\sim$71\\% of grand maxima during the period from 6600 BC to 1650 AD were followed by a grand minimum. The occurrence characteristics of grand maxima and mini...

  2. Applying quantitative structure-activity relationship approaches to nanotoxicology: current status and future potential.

    Winkler, David A; Mombelli, Enrico; Pietroiusti, Antonio; Tran, Lang; Worth, Andrew; Fadeel, Bengt; McCall, Maxine J

    2013-11-01

    The potential (eco)toxicological hazard posed by engineered nanoparticles is a major scientific and societal concern since several industrial sectors (e.g. electronics, biomedicine, and cosmetics) are exploiting the innovative properties of nanostructures resulting in their large-scale production. Many consumer products contain nanomaterials and, given their complex life-cycle, it is essential to anticipate their (eco)toxicological properties in a fast and inexpensive way in order to mitigate adverse effects on human health and the environment. In this context, the application of the structure-toxicity paradigm to nanomaterials represents a promising approach. Indeed, according to this paradigm, it is possible to predict toxicological effects induced by chemicals on the basis of their structural similarity with chemicals for which toxicological endpoints have been previously measured. These structure-toxicity relationships can be quantitative or qualitative in nature and they can predict toxicological effects directly from the physicochemical properties of the entities (e.g. nanoparticles) of interest. Therefore, this approach can aid in prioritizing resources in toxicological investigations while reducing the ethical and monetary costs that are related to animal testing. The purpose of this review is to provide a summary of recent key advances in the field of QSAR modelling of nanomaterial toxicity, to identify the major gaps in research required to accelerate the use of quantitative structure-activity relationship (QSAR) methods, and to provide a roadmap for future research needed to achieve QSAR models useful for regulatory purposes. PMID:23165187

  3. Three Financing Constraint Hypotheses and Inventory Investment: New Tests With Time and Sectoral Heterogeneity

    Robert E. Carpenter; Steven M. Fazzari; Petersen, Bruce C

    1995-01-01

    Over the last decade, research has shown that financing constraints have an important impact on many aspects of firm behavior and aggregate fluctuations. This paper undertakes a critical comparison of the three main financing constraint hypotheses- -the bank lending, collateral, and internal finance hypotheses. To discriminate between hypotheses, we extend existing methodology by focusing on time and sectoral heterogeneity in high-frequency (quarterly) firm data. We find evidence consistent w...

  4. Personal Bankruptcy: Reconciling Adverse Events and Strategic Timing Hypotheses Using Heterogeneity in Filing Types

    Li Gan; Tarun Sabarwal; Shuoxun Zhang

    2010-01-01

    The strategic timing and adverse events hypotheses of personal bankruptcy have received particular attention. Existing research focuses on proving or disproving either hypothesis, using a strict interpretation of the role of financial benefit in the filing decision. Using a more realistic framework in which financial benefit may affect the filing decision in both hypotheses, we show that endogeneity of financial benefit is a distinguishing factor between the two hypotheses. Using two differen...

  5. Observation of SOL Current Correlated with MHD Activity in NBI-heated DIII-D Tokamak Discharges

    This work investigates the potential roles played by the scrape-off-layer current (SOLC) in MHD activity of tokamak plasmas, including effects on stability. SOLCs are found during MHD activity that are: (1) slowly growing after a mode-locking-like event, (2) oscillating in the several kHz range and phase-locked with magnetic and electron temperature oscillations, (3) rapidly growing with a sub-ms time scale during a thermal collapse and a current quench, and (4) spiky in temporal behavior and correlated with spiky features in Da signals commonly identified with the edge localized mode (ELM). These SOLCs are found to be an integral part of the MHD activity, with a propensity to flow in a toroidally non-axisymmetric pattern and with magnitude potentially large enough to play a role in the MHD stability. Candidate mechanisms that can drive these SOLCs are identified: (a) toroidally non-axisymmetric thermoelectric potential, (b) electromotive force (EMF) from MHD activity, and (c) flux swing, both toroidal and poloidal, of the plasma column. An effect is found, stemming from the shear in the field line pitch angle, that mitigates the efficacy of a toroidally non-axisymmetric SOLC to generate a toroidally non-axisymmetric error field. Other potential magnetic consequences of the SOLC are identified: (i) its error field can introduce complications in feedback control schemes for stabilizing MHD activity and (ii) its toroidally non-axisymmetric field can be falsely identified as an axisymmetric field by the tokamak control logic and in equilibrium reconstruction. The radial profile of a SOLC observed during a quiescent discharge period is determined, and found to possess polarity reversals as a function of radial distance

  6. Observation of SOL Current Correlated with MHD Activity in NBI-heated DIII-D Tokamak Discharges

    H. Takahashi; E.D. Fredrickson; M.J. Schaffer; M.E. Austin; T.E. Evans; L.L. Lao; J.G. Watkins

    2004-03-26

    This work investigates the potential roles played by the scrape-off-layer current (SOLC) in MHD activity of tokamak plasmas, including effects on stability. SOLCs are found during MHD activity that are: (1) slowly growing after a mode-locking-like event, (2) oscillating in the several kHz range and phase-locked with magnetic and electron temperature oscillations, (3) rapidly growing with a sub-ms time scale during a thermal collapse and a current quench, and (4) spiky in temporal behavior and correlated with spiky features in Da signals commonly identified with the edge localized mode (ELM). These SOLCs are found to be an integral part of the MHD activity, with a propensity to flow in a toroidally non-axisymmetric pattern and with magnitude potentially large enough to play a role in the MHD stability. Candidate mechanisms that can drive these SOLCs are identified: (a) toroidally non-axisymmetric thermoelectric potential, (b) electromotive force (EMF) from MHD activity, and (c) flux swing, both toroidal and poloidal, of the plasma column. An effect is found, stemming from the shear in the field line pitch angle, that mitigates the efficacy of a toroidally non-axisymmetric SOLC to generate a toroidally non-axisymmetric error field. Other potential magnetic consequences of the SOLC are identified: (i) its error field can introduce complications in feedback control schemes for stabilizing MHD activity and (ii) its toroidally non-axisymmetric field can be falsely identified as an axisymmetric field by the tokamak control logic and in equilibrium reconstruction. The radial profile of a SOLC observed during a quiescent discharge period is determined, and found to possess polarity reversals as a function of radial distance.

  7. Influence of a voltage compensation type active superconducting fault current limiter on the transient stability of power system

    Chen, L.; Tang, Y. J.; Shi, J.; Chen, N.; Song, M.; Cheng, S. J.; Hu, Y.; Chen, X. S.

    2009-10-01

    We have proposed a voltage compensation type active superconducting fault current limiter (SFCL). In this paper, the influence of the SFCL on the transient stability of power system is investigated. For the typical one-machine infinite-bus system, the power-angle characteristics of generator with SFCL are studied in different working conditions, and the transient physical process is analyzed. Using MATLAB SIMULINK, the power-angle swing curves are simulated under different current-limiting modes, fault types and fault clearance times. The results show that the proposed SFCL can effectively reduce the transient swing amplitude of rotor and extend the critical clearance time under mode 1, compared with mode 2 and mode 3 having few effects on enhancing the transient stability.

  8. Influence of a voltage compensation type active superconducting fault current limiter on the transient stability of power system

    Chen, L., E-mail: stclchen1982@yahoo.com.c [R and D Center of Applied Superconductivity, Huazhong University of Science and Technology, Wuhan 430074 (China); Tang, Y.J.; Shi, J.; Chen, N.; Song, M.; Cheng, S.J. [R and D Center of Applied Superconductivity, Huazhong University of Science and Technology, Wuhan 430074 (China); Hu, Y.; Chen, X.S. [State Grid Electric Power Research Institute, Wuhan 430074 (China)

    2009-10-15

    We have proposed a voltage compensation type active superconducting fault current limiter (SFCL). In this paper, the influence of the SFCL on the transient stability of power system is investigated. For the typical one-machine infinite-bus system, the power-angle characteristics of generator with SFCL are studied in different working conditions, and the transient physical process is analyzed. Using MATLAB SIMULINK, the power-angle swing curves are simulated under different current-limiting modes, fault types and fault clearance times. The results show that the proposed SFCL can effectively reduce the transient swing amplitude of rotor and extend the critical clearance time under mode 1, compared with mode 2 and mode 3 having few effects on enhancing the transient stability.

  9. Influence of a voltage compensation type active superconducting fault current limiter on the transient stability of power system

    We have proposed a voltage compensation type active superconducting fault current limiter (SFCL). In this paper, the influence of the SFCL on the transient stability of power system is investigated. For the typical one-machine infinite-bus system, the power-angle characteristics of generator with SFCL are studied in different working conditions, and the transient physical process is analyzed. Using MATLAB SIMULINK, the power-angle swing curves are simulated under different current-limiting modes, fault types and fault clearance times. The results show that the proposed SFCL can effectively reduce the transient swing amplitude of rotor and extend the critical clearance time under mode 1, compared with mode 2 and mode 3 having few effects on enhancing the transient stability.

  10. Thrombolysis by intravenous tissue plasminogen activator (t-PA). Current status and future direction

    In Japan, the intravenous tissue plasminogen activator (t-PA) Alteplase (0.6 mg/kg) administration of the within 3 h of the onset of acute ischemic stroke was approved for therapeutic use in the year 2006. t-PA induces thrombolysis in patients with acute ischemic stroke, and this method has gradually gained recognition among physicians and the general population. However, the number of patients who were treated using Alteplase is low (4,000-5,000 patients/year), and this figure accounts for only 2-3% of the annual number of cases of ischemic stroke. There is little doubt that Alteplase treatment is a potentially effective modality for some patients with acute ischemic stroke. The post-marketing surveillance of 4,749 Japanese patients treated using Alteplase showed that 33% of the patients had modified Rankin scale (mRS) scores of 0-1, 17% of patients died and 4.5% presented with symptomatic intracerebral hemorrhage (ICH); these results were comparable to those from other countries. The expansion of the therapeutic time window has been a matter of concern. The investigators of the European Cooperative Acute Stroke Study (ECASS) have reported that there was significant improvement in the clinical outcomes of patients with acute ischemie stroke when Alteplase was administered 3-4.5 h after the onset of the symptoms. Mismatches in perfusion- and diffusion-weighted (DW) magnetic resonance imaging (MRI) images have been used for selecting patients 3 h after the onset of symptoms, and the findings from MRI, dwimages (DWI) and MR angiography are practical predictors of t-PA therapy within 3 h of onset. The Middle Cerebral Artery Embolism Local Fibrinolytic Intervention Trial (MELT) Japan study showed that local intra-arterial fibrinolysis is effective in patients with embolic MCA occlusion within 6 h of the onset of symptoms. Combining the initiation of intravenous t-PA administration with further intra-arterial fibrinolysis or mechanical thrombolectomy may improve the

  11. Recruitment processes in Baltic sprat - A re-evaluation of GLOBEC Germany hypotheses

    Voss, Rüdiger; Peck, Myron A.; Hinrichsen, Hans-Harald; Clemmesen, Catriona; Baumann, Hannes; Stepputtis, Daniel; Bernreuther, Matthias; Schmidt, Jörn O.; Temming, Axel; Köster, Fritz W.

    2012-12-01

    The GLOBEC Germany program (2002-2007) had the ambitious goal to resolve the processes impacting the recruitment dynamics of Baltic sprat (Sprattus sprattus L.) by examining various factors affecting early life history stages. At the start of the research program, a number of general recruitment hypotheses were formulated, i.e. focusing on (1) predation, (2) food availability, (3) physical parameters, (4) the impact of current systems, and finally (5) the importance of top-down vs bottom-up effects. The present study synthesizes the results of field sampling (2002 and 2003), laboratory experiments, and modeling studies to re-evaluate these hypotheses for the Baltic sprat stock. Recruitment success was quite different in the 2 years investigated. Despite a lower spawning stock biomass in 2003, the total number of recruits was almost 2-fold higher that year compared to 2002. The higher recruitment success in 2003 could be attributed to enhanced survival success during the post-larval/juvenile stage, a life phase that appears to be critical for recruitment dynamics. In the state of the Baltic ecosystem during the period of investigation, we consider bottom-up control (e.g. temperature, prey abundance) to be more important than top-down control (predation mortality). This ranking in importance does not vary seasonally. Prevailing water circulation patterns and the transport dynamics of larval cohorts have a strong influence on sprat recruitment success. Pronounced transport to coastal areas is detrimental for year-class strength particularly at high sprat stock sizes. A suggested mechanism is density-dependant regulation of survival via intra- and inter-specific competition for prey in coastal areas. A documented change in larval vertical migration behavior between the early 1990s and early 2000s increased the transport potential to the coast, strengthening the coupling between inter-annual differences in the magnitude and direction of wind-driven surface currents and

  12. Study on Current Levels of Physical Activity and Sedentary Behavior among Middle School Students in Beijing, China.

    Jiali Duan

    Full Text Available This study aimed to determine current levels of physical activity and sedentary behavior in middle school students on the basis of grade, sex, student attitudes toward physical education, and residence location.In 2013, a cross-sectional study of 1793 students aged 12 to 15 years was conducted across eight middle schools in Beijing, China. Four schools were selected from an urban district and another four schools were from a suburban district. Physical activity and sedentary behavior data were collected using the commonly used school-based Chinese version of the China Health and Nutrition Survey.The mean age of sampled students was 13.3 ± 1.0 years; 51.5% were boys. Approximately 76.6% of students reported having three 45-minute physical education classes every week. A total of 35.6% students spent ≥ 1 h/day performing moderate to vigorous physical activity (MVPA during school, and 34.9% spent ≥ 1 h/day in MVPA outside school time. Approximately half (49.7% of the students engaged in reading, writing, or drawing for ≥ 2 h/day, and 42.9% reported screen time for ≥ 2 h/day. Although boys spent more time engaged in physical activity than girls did, they also spent more time exhibiting sedentary behavior. Each 10-unit increase in attitudes toward physical education was associated with an increased odds of 1.15 (95%CI: 1.09-1.20 for spending more than 1 h/day on MVPA. Students in suburban schools reported engaging in physical activity less when compared with those in urban schools.The majority of our students did not meet the current physical activity recommendations, and about half of the students spent excessive time engaging in sedentary behaviors. Findings from this study highlight a positive association between student attitudes toward physical education and physical activity. Studies are needed to further explore the role of student attitudes toward physical education in promoting physical activity among Chinese students.

  13. A Component-Minimized Single-Phase Active Power Decoupling Circuit with Reduced Current Stress to Semiconductor Switches

    Tang, Yi; Blaabjerg, Frede

    2015-01-01

    This letter proposes a novel circuit topology which can realize the power decoupling function without adding additional active switches into the circuit. The dc-link capacitor of a full bridge rectifier is split into two identical parts and the midpoint is connected to one leg through a filter...... component, e.g. inductors or film capacitors for ripple energy storage because this task can be accomplished by the dc-link capacitors, and therefore its implementation cost can be minimized. Another unique feature of the proposed topology is that the current stress of power semiconductors can be reduced...

  14. Transient Receptor Potential Vanilloid 4 Inhibits γ-Aminobutyric Acid-Activated Current in Hippocampal Pyramidal Neurons

    Hong, Zhiwen; Tian, Yujing; Qi, Mengwen; Li, Yingchun; Du, Yimei; Chen, Lei; Liu, Wentao; Chen, Ling

    2016-01-01

    The balance between excitatory and inhibitory neurotransmitter systems is crucial for the modulation of neuronal excitability in the central nervous system (CNS). The activation of transient receptor potential vanilloid 4 (TRPV4) is reported to enhance the response of hippocampal glutamate receptors, but whether the inhibitory neurotransmitter system can be regulated by TRPV4 remains unknown. γ-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the CNS. Here, we show that application of transient receptor potential vanilloid 4 (TRPV4) synthetic (GSK1016790A or 4α-PDD) or endogenous agonist (5,6-EET) inhibited GABA-activated current (IGABA) in hippocampal CA1 pyramidal neurons, which was blocked by specific antagonists of TRPV4 and of GABAA receptors. GSK1016790A increased the phosphorylated AMP-activated protein kinase (p-AMPK) and decreased the phosphorylated protein kinase B (p-Akt) protein levels, which was attenuated by removing extracellular calcium or by a calcium/calmodulin-dependent protein kinase kinase-β antagonist. GSK1016790A-induced decrease of p-Akt protein level was sensitive to an AMPK antagonist. GSK1016790A-inhibited IGABA was blocked by an AMPK antagonist or a phosphatidyl inositol 3 kinase (PI3K) agonist. GSK1016790A-induced inhibition of IGABA was also significantly attenuated by a protein kinase C (PKC) antagonist but was unaffected by protein kinase A or calcium/calmodulin-dependent protein kinase II antagonist. We conclude that activation of TRPV4 inhibits GABAA receptor, which may be mediated by activation of AMPK and subsequent down-regulation of PI3K/Akt signaling and activation of PKC signaling. Inhibition of GABAA receptors may account for the neuronal hyperexcitability caused by TRPV4 activation.

  15. Functional relations between locomotor performance traits in spiders and implications for evolutionary hypotheses

    Taylor Phillip W

    2010-11-01

    Full Text Available Abstract Background Locomotor performance in ecologically relevant activities is often linked to individual fitness. Recent controversy over evolution of extreme sexual size dimorphism (SSD in spiders centres on the relationship between size and locomotor capacity in males. Advantages for large males running over horizontal surfaces and small males climbing vertically have been proposed. Models have implicitly treated running and climbing as functionally distinct activities and failed to consider the possibility that they reflect common underlying capacities. Findings We examine the relationship between maximum climbing and running performance in males of three spider species. Maximum running and climbing speeds were positively related in two orb-web spiders with high SSD (Argiope keyserlingi and Nephila plumipes, indicating that for these species assays of running and climbing largely reveal the same underlying capacities. Running and climbing speeds were not related in a jumping spider with low SSD (Jacksonoides queenslandica. We found no evidence of a performance trade-off between these activities. Conclusions In the web-spiders A. keyserlingi and N. plumipes good runners were also good climbers. This indicates that climbing and running largely represent a single locomotor performance characteristic in these spiders, but this was not the case for the jumping spider J. queenslandica. There was no evidence of a trade-off between maximum running and climbing speeds in these spiders. We highlight the need to establish the relationship between apparently disparate locomotor activities when testing alternative hypotheses that yield predictions about different locomotor activities. Analysis of slopes suggests greater potential for an evolutionary response on performance in the horizontal compared to vertical context in these spiders.

  16. Defect generation and activation processes in HfO2 thin films: Contributions to stress-induced leakage currents

    An important source of degradation in thin dielectric material layers is the generation and migration of oxygen vacancies. We investigated the formation of Frenkel pairs (FPs) in HfO2 as the first structural step for the creation of new defects as well as the migration of preexisting and newly built oxygen vacancies by nudged elastic band (NEB) calculations and stress induced leakage current (SILC) experiments. The analysis indicates, that for neutral systems no stable intimate FPs are built, whereas for the charge states q = ± 2 FPs are formed at threefold and at fourfold coordinated oxygen lattice sites. Their generation and annihilation rate are in equilibrium according to the Boltzmann statistics. Distant FPs (stable defects) are unlikely to build due to high formation energies and therefore cannot be accounted for the measured gate leakage current increase of nMOSFETs under constant voltage stress. The negatively charged oxygen vacancies were found to be very immobile in contrast to positively charged V0's with a low migration barrier that coincides well with the experimentally obtained activation energy. We show that rather the activation of preexisting defects and migration towards the interface than the defect generation are the cause for the gate oxide degradation. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Defect generation and activation processes in HfO{sub 2} thin films: Contributions to stress-induced leakage currents

    Oettking, Rolf; Leitsmann, Roman; Lazarevic, Florian; Plaenitz, Philipp [AQcomputare, Business Unit MATcalc, Chemnitz (Germany); Kupke, Steve; Roll, Guntrade; Slesazeck, Stefan [NaMLab gGmbH, Dresden (Germany); Nadimi, Ebrahim [AQcomputare, Business Unit MATcalc, Chemnitz (Germany); K.N. Toosi University of Technology, Faculty of Electrical Engineering, Tehran (Iran, Islamic Republic of); Trentzsch, Martin [Globalfoundries Dresden, Dresden (Germany); Mikolajick, Thomas [Technische Universitaet Dresden, Fakultaet Elektrotechnik und Informationstechnik, Institut fuer Halbleiter- und Mikrosystemtechnik, Dresden (Germany)

    2015-03-01

    An important source of degradation in thin dielectric material layers is the generation and migration of oxygen vacancies. We investigated the formation of Frenkel pairs (FPs) in HfO{sub 2} as the first structural step for the creation of new defects as well as the migration of preexisting and newly built oxygen vacancies by nudged elastic band (NEB) calculations and stress induced leakage current (SILC) experiments. The analysis indicates, that for neutral systems no stable intimate FPs are built, whereas for the charge states q = ± 2 FPs are formed at threefold and at fourfold coordinated oxygen lattice sites. Their generation and annihilation rate are in equilibrium according to the Boltzmann statistics. Distant FPs (stable defects) are unlikely to build due to high formation energies and therefore cannot be accounted for the measured gate leakage current increase of nMOSFETs under constant voltage stress. The negatively charged oxygen vacancies were found to be very immobile in contrast to positively charged V{sub 0}'s with a low migration barrier that coincides well with the experimentally obtained activation energy. We show that rather the activation of preexisting defects and migration towards the interface than the defect generation are the cause for the gate oxide degradation. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Effects of Atractylodes Macrocephala on the Cytomembrane Ca2+-activated K+ Currents in Cells of Human Pregnant Myometrial Smooth Muscles

    Xiaoli ZHANG; Lin WANG; Long XU; Li ZOU

    2008-01-01

    The study examined the inhibitory effect of Atractylodes macrocephala (AM) on the uterine contraction during premature delivery and explored its electrophysiological mechanism by studying the effects of AM on the Ca2+-activated K+ currents of pregnant human myometrial smooth muscle cells with or without the treatment with interleukin-6. Single cells were acutely isolated from pregnant human myometrial smooth muscles. Whole-cell Ca2+-activated K+ currents were recorded by using an Axopatchl-D amplifier. The cells were divided into three groups: group A in which AM was added into perfusate, group B, in which intefleukin-6 was added into perfusate) and group C in which AM was added into perfusate after addition of interleukin-6. IL-6 10 ng/mL inhibited Bkca by 36.9%±13.7% as compared with control (P<0.01). AM at 2 mg/mL raised Bkca by 36.7%±22.6% or 45.2%±13.7% with or without the treatment of IL-6, respectively (P<0.01). It is concluded that AM was able to enhance the Bkca of pregnant human myometrial smooth muscle cells treated or un- treated with interleukin-6 and its effect on the Bkca IL-treated cells was stronger that its effect on Bkca of untreated cells. Our results suggested that AM can help to maintain the membrane potentials and the resting status of pregnant human myometrial smooth muscle cells.

  19. From geospatial observations of ocean currents to causal predictors of spatio-economic activity using computer vision and machine learning

    Popescu, Florin; Ayache, Stephane; Escalera, Sergio; Baró Solé, Xavier; Capponi, Cecile; Panciatici, Patrick; Guyon, Isabelle

    2016-04-01

    The big data transformation currently revolutionizing science and industry forges novel possibilities in multi-modal analysis scarcely imaginable only a decade ago. One of the important economic and industrial problems that stand to benefit from the recent expansion of data availability and computational prowess is the prediction of electricity demand and renewable energy generation. Both are correlates of human activity: spatiotemporal energy consumption patterns in society are a factor of both demand (weather dependent) and supply, which determine cost - a relation expected to strengthen along with increasing renewable energy dependence. One of the main drivers of European weather patterns is the activity of the Atlantic Ocean and in particular its dominant Northern Hemisphere current: the Gulf Stream. We choose this particular current as a test case in part due to larger amount of relevant data and scientific literature available for refinement of analysis techniques. This data richness is due not only to its economic importance but also to its size being clearly visible in radar and infrared satellite imagery, which makes it easier to detect using Computer Vision (CV). The power of CV techniques makes basic analysis thus developed scalable to other smaller and less known, but still influential, currents, which are not just curves on a map, but complex, evolving, moving branching trees in 3D projected onto a 2D image. We investigate means of extracting, from several image modalities (including recently available Copernicus radar and earlier Infrared satellites), a parameterized representation of the state of the Gulf Stream and its environment that is useful as feature space representation in a machine learning context, in this case with the EC's H2020-sponsored 'See.4C' project, in the context of which data scientists may find novel predictors of spatiotemporal energy flow. Although automated extractors of Gulf Stream position exist, they differ in methodology

  20. Why do niches develop in Caesarean uterine scars? Hypotheses on the aetiology of niche development

    Vervoort, A.J.M.W.; Uittenbogaard, L.B.; Hehenkamp, W.J.K.; Brölmann, H.A.M.; Mol, B.W.J.; Huirne, J.A.F.

    2015-01-01

    Caesarean section (CS) results in the occurrence of the phenomenon ‘niche’. A ‘niche’ describes the presence of a hypoechoic area within the myometrium of the lower uterine segment, reflecting a discontinuation of the myometrium at the site of a previous CS. Using gel or saline instillation sonohysterography, a niche is identified in the scar in more than half of the women who had had a CS, most with the uterus closed in one single layer, without closure of the peritoneum. An incompletely healed scar is a long-term complication of the CS and is associated with more gynaecological symptoms than is commonly acknowledged. Approximately 30% of women with a niche report spotting at 6–12 months after their CS. Other reported symptoms in women with a niche are dysmenorrhoea, chronic pelvic pain and dyspareunia. Given the association between a niche and gynaecological symptoms, obstetric complications and potentially with subfertility, it is important to elucidate the aetiology of niche development after CS in order to develop preventive strategies. Based on current published data and our observations during sonographic, hysteroscopic and laparoscopic evaluations of niches we postulate some hypotheses on niche development. Possible factors that could play a role in niche development include a very low incision through cervical tissue, inadequate suturing technique during closure of the uterine scar, surgical interventions that increase adhesion formation or patient-related factors that impair wound healing or increase inflammation or adhesion formation. PMID:26409016

  1. Daydreaming Style Moderates the Relation between Working Memory and Mind Wandering: Integrating Two Hypotheses

    Marcusson-Clavertz, David; Cardeña, Etzel; Terhune, Devin Blair

    2016-01-01

    Mind wandering--mentation unrelated to one's current activity and surroundings--is a ubiquitous phenomenon, but seemingly competing ideas have been proposed regarding its relation to executive cognitive processes. The control-failure hypothesis postulates that executive processes prevent mind wandering, whereas the global availability hypothesis…

  2. Evolution of microgastropods (Ellobioidea, Carychiidae: integrating taxonomic, phylogenetic and evolutionary hypotheses

    Weigand Alexander M

    2013-01-01

    Full Text Available Abstract Background Current biodiversity patterns are considered largely the result of past climatic and tectonic changes. In an integrative approach, we combine taxonomic and phylogenetic hypotheses to analyze temporal and geographic diversification of epigean (Carychium and subterranean (Zospeum evolutionary lineages in Carychiidae (Eupulmonata, Ellobioidea. We explicitly test three hypotheses: 1 morphospecies encompass unrecognized evolutionary lineages, 2 limited dispersal results in a close genetic relationship of geographical proximally distributed taxa and 3 major climatic and tectonic events had an impact on lineage diversification within Carychiidae. Results Initial morphospecies assignments were investigated by different molecular delimitation approaches (threshold, ABGD, GMYC and SP. Despite a conservative delimitation strategy, carychiid morphospecies comprise a great number of unrecognized evolutionary lineages. We attribute this phenomenon to historic underestimation of morphological stasis and phenotypic variability amongst lineages. The first molecular phylogenetic hypothesis for the Carychiidae (based on COI, 16S and H3 reveals Carychium and Zospeum to be reciprocally monophyletic. Geographical proximally distributed lineages are often closely related. The temporal diversification of Carychiidae is best described by a constant rate model of diversification. The evolution of Carychiidae is characterized by relatively few (long distance colonization events. We find support for an Asian origin of Carychium. Zospeum may have arrived in Europe before extant members of Carychium. Distantly related Carychium clades inhabit a wide spectrum of the available bioclimatic niche and demonstrate considerable niche overlap. Conclusions Carychiid taxonomy is in dire need of revision. An inferred wide distribution and variable phenotype suggest underestimated diversity in Zospeum. Several Carychium morphospecies are results of past taxonomic

  3. Recent and current activities of the OECD/NEA Working Group on Fuel Safety (NEA/CSNI). Recent and Current Activities of the Working Group on Fuel Safety (NEA/CSNI)

    The Working Group on Fuel Safety (WGFS) is part of the Committee on the Safety of Nuclear Installations (CSNI) of the Nuclear Energy Agency and has the main mission of advancing the current understanding and addressing fuel safety issues. Recent and current activities of the working group have addressed mainly the loss of coolant accident (LOCA), the reactivity initiated accident (RIA), the fuel safety criteria and leaking fuel issues, as well as Fukushima-related fuel topics. In the area of LOCA, the group issued different documents, the most notable being a very comprehensive state of the art report [NEA/CSNI/R (2009)15]. Regarding RIA, some documents were finalised and issued in the recent years, as well as a state of the art report [NEA/CSNI/R (2010)1]. The question of leaking fuel and how it is handled in the reactors is an activity that is just starting. Of particular interest to people developing new fuel concepts is the Nuclear Fuel Safety Criteria Technical Review - Second Edition [NEA/CSNI/R (2012)3]. This document provides a broad overview of the numerous criteria used in the NEA member countries to demonstrate to safe use of fuel in light water reactors. The WGFS has started discussions about fuel related issues raised by the Fukushima accident, in particular, hydrogen production. New concepts have been proposed to solve these issues but it appears that these concepts will need to go through a long qualification process to assess their adequacy for the different situations considered in the evaluation of fuel safety, from normal operation to accident conditions

  4. Upgrade of the ESA DRAMA OSCAR Tool: Analysis of Disposal Strategies Considering Current Standards for Future Solar and Geomagnetic Activity

    Braun, V.; Sanchez-Ortiz, N.; Gelhaus, J.; Kebschull, C.; Flegel, S.; Mockel, M.; Wiedemann, C.; Krag, H.; Vorsmann, P.

    2013-08-01

    In 2008 the UN General Assembly adopted resolution 62/217, endorsing the space debris mitigation guidelines (SDMG) of the UN Committee on the Peaceful Uses of Outer Space (UNCOPUOS). These guidelines contain recommendations for satellite operators to implement measures for various mission phases in order to reduce the further accumulation of space debris in space and especially within the protected regions. These are defined within the SDMG as being the LEO region (up to 2,000 km altitude) and the GEO region (∼200 km in altitude around the GEO altitude and ∼15 degrees latitude). In the first version of ESA's DRAMA tool suite, OSCAR (Orbital SpaceCraft Active Removal) was designed as a tool to allow users the analysis of different disposal stragies for spacecraft in the LEO and GEO region. The upgrade of the ESA DRAMA tool suite by TUBS and DEIMOS under ESA/ESOC contract included the development of a renewed version of the existing OSCAR tool, allowing in its current version the consideration of different future solar and geomagnetic activity scenarios and besides the already known disposal systems (chemical and electric propulsion, as well as electrodynamic tether) the analysis of the orbital evolution using drag augmentation devices. One of the primary goals was to implement techniques recommended by current standards. The recommendations from the SDMG were used for the definition of the critical regions as well as compliance criteria, the user may check his disposal strategy against. For satellites operating in GEO, the ISO 26872:2010 (Space Systems - Disposal of satellites operating at geosynchronous altitude) standard was accounted for. For the generation of future solar and geomagnetic activity, the standards ISO 27852:2011 (Space Systems -Estimation of orbit lifetime) and the ECSS-E-ST-10-04C (Space engineering - Space environment) have been considered and recommended modeling approaches were implemented. In this paper, the OSCAR tool is presented, giving

  5. Effects of novel subtype selective M-current activators on spinal reflexes in vitro: Comparison with retigabine.

    Vicente-Baz, Jorge; Lopez-Garcia, Jose A; Rivera-Arconada, Ivan

    2016-10-01

    The activation of Kv7 channels and the resulting M-current is a powerful mechanism to control neuronal excitability with profound effects in pain pathways. Despite the lack of specific data on the expression and role of these channels in nociceptive processing, much attention has been paid at exploring their potential value as targets for analgesia. Here we have characterized the spinal actions of two novel subunit selective Kv7 activators, ICA-069673 and ML213, and compared their effects to those of retigabine that acts with similar affinity on all neuronal Kv7 channels. Spinal reflexes were recorded in a mouse spinal cord in vitro preparation to allow the testing of the compounds on native spinal pathways at known concentrations. As retigabine, novel compounds depressed spinal segmental transmission with particularly strong effects on wind up, showing an adequate pro-analgesic profile. ML213 presented the highest potency. In contrast to retigabine, the effects of ICA-069673 and ML213 were blocked by XE-991 even at the highest concentrations used, suggesting specific effect on Kv7 channels. In addition, the effects of ICA-069673 on repetitive stimulation are consistent with a mode of action involving state or activity dependent interaction with the channels. Compared to retigabine, novel Kv7 openers maintain strong depressant effects on spinal nociceptive transmission showing an improved specificity on Kv7 channels. The differential effects obtained with these Kv7 openers may indicate the existence of several Kv7 conformations in spinal circuits. PMID:27263036

  6. Impacts Of Radiatively-Active Aerosols On Mars’ Current Climate: Simulation Results With The NASA ARC Mars GCM

    Hollingsworth, Jeffery L.; Kahre, M. A.; Haberle, R. M.; Montmessin, F.; Herin, B.; Laamoumi, F.; Wilson, R. J.; Schaeffer, J.

    2010-10-01

    Recent upgrades to the NASA Ames Research Center (ARC) Mars general circulation model (GCM) include a fundamentally new and modernized radiative transfer package which permits radiative effects and interactions of suspended atmospheric aerosols (e.g., water ice clouds, water vapor, dust, and their mutual interactions) to influence the net diabatic heating rate within the atmosphere. Such aerosols are critically important in determining the nature of atmospheric thermal structure and hence the overall climate of the planet. Our Mars GCM simulations indicate that radiatively-active water ice clouds profoundly affect the seasonal and annual mean climate in a variety of ways. In particular, preliminary results suggest that the bulk thermal structure and resultant (i.e., balanced) circulation patterns are strongly modified near the surface and aloft. Generally speaking, we find a bulk warming of the atmosphere in upper layers, a cooling of the atmosphere in the lower and near-surface regions, and, increases in the mean pole-to-equator temperature contrasts (i.e., stronger mean polar vortices). A variety of results from our baseline and control simulations (i.e., where the radiative/physical effects are examined in isolation and when combined) will be presented. Comparisons with MGS/TES and MRO/MCS measurements indicate better agreement between the model's simulated climate compared to that observed. Using a state-of-the-art Mars GCM, these results highlight important effects radiatively-active aerosols have on physical and dynamical processes active in the current climate of Mars.

  7. The role of the medial longitudinal fasciculus in horizontal gaze: tests of current hypotheses for saccade-vergence interactions

    Chen, Athena L.; Ramat, Stefano; Serra, Alessandro; King, Susan A.; Leigh, R. John

    2010-01-01

    Rapid shifts of the point of visual fixation between equidistant targets require equal-sized saccades of each eye. The brainstem medial longitudinal fasciculus (MLF) plays a cardinal role in ensuring that horizontal saccades between equidistant targets are tightly yoked. Lesions of the MLF—internuclear ophthalmoparesis (INO)—cause horizontal saccades to become disjunctive: adducting saccades are slow, small, or absent. However, in INO, convergence movements may remain intact. We studied horiz...

  8. Use of spatial analysis to test hypotheses on plant recruitment in a hyper-arid ecosystem.

    Jan J Quets

    Full Text Available Mounds originating from wind-blown sediment accumulation beneath vegetation (nebkhas often indicate land degradation in dry areas. Thus far, most nebkha research has focused on individual plants. Here, we aimed to explore population-scale processes (up to scales of about 100 m that might explain an observed nebkha landscape pattern. We mapped the Rhazya stricta Decne. population in a 3 ha study site in a hyper-arid region of Saudi Arabia. We compared the spatial patterns of five different cohorts (age classes of observed nebkha host plants to those expected under several hypothesized drivers of recruitment and intraspecific interaction. We found that all R. stricta cohorts had a limited fractional vegetation cover and established in large-scale clusters. This clustering weakened with cohort age, possibly indicating merging of neighboring vegetation patches. Different cohort clusters did not spatially overlap in most cases, indicating that recruitment patterns changed position over time. Strong indications were found that the main drivers underlying R. stricta spatial configurations were allogenic (i.e. not driven by vegetation and dynamic. Most likely these drivers were aeolian-driven sand movement or human disturbance which forced offspring recruitment in spatially dynamic clusters. Competition and facilitation were likely active on the field site too, but apparently had a limited effect on the overall landscape structure.

  9. Use of spatial analysis to test hypotheses on plant recruitment in a hyper-arid ecosystem.

    Quets, Jan J; Temmerman, Stijn; El-Bana, Magdy I; Al-Rowaily, Saud L; Assaeed, Abdulaziz M; Nijs, Ivan

    2014-01-01

    Mounds originating from wind-blown sediment accumulation beneath vegetation (nebkhas) often indicate land degradation in dry areas. Thus far, most nebkha research has focused on individual plants. Here, we aimed to explore population-scale processes (up to scales of about 100 m) that might explain an observed nebkha landscape pattern. We mapped the Rhazya stricta Decne. population in a 3 ha study site in a hyper-arid region of Saudi Arabia. We compared the spatial patterns of five different cohorts (age classes) of observed nebkha host plants to those expected under several hypothesized drivers of recruitment and intraspecific interaction. We found that all R. stricta cohorts had a limited fractional vegetation cover and established in large-scale clusters. This clustering weakened with cohort age, possibly indicating merging of neighboring vegetation patches. Different cohort clusters did not spatially overlap in most cases, indicating that recruitment patterns changed position over time. Strong indications were found that the main drivers underlying R. stricta spatial configurations were allogenic (i.e. not driven by vegetation) and dynamic. Most likely these drivers were aeolian-driven sand movement or human disturbance which forced offspring recruitment in spatially dynamic clusters. Competition and facilitation were likely active on the field site too, but apparently had a limited effect on the overall landscape structure. PMID:24614307

  10. Comparison of morphology of active cyclic steps created by turbidity currents on Squamish Delta, British Columbia, Canada with flume experiments

    Yokokawa, Miwa; Yamamoto, Shinya; Higuchi, Hiroyuki; Hughes Clarke, John E.; Izumi, Norihiro

    2015-04-01

    Upper-flow-regime bedforms, such as cyclic steps and antidunes, have been reported to be formed by turbidity currents. Their formative conditions are, however, not fully understood because of the difficulty of field surveys in the deep sea. Field observations of turbidity currents and seabed topography on the Squamish delta in Howe Sound, British Columbia, Canada have been undertaken which found bedwaves actively migrating in the upstream direction in channels formed on the prodelta slope. Their topography and behavior suggest that they are cyclic steps formed by turbidity currents. Because Squamish delta is as shallow as around 150 m, and easy to access compared with general submarine canyons, it is thought to be one of the best places for studying characteristics of cyclic steps formed by turbidity currents through field observations. In this study, we have analyzed configurations of cyclic steps with the use of data obtained in the field observation of 2011, and compare them with the data from the flume experiments. On the prodelta slope, three major active channels are clearly developed. In addition to the sonar survey, a 600 kHz ADCP was installed in 150m of water just seaward of the termination of the North Channel. In addition, 1200kHz ADCP and 500kHz M3s are suspended from the research vessel in 60 m of water and 300 m distance from the delta edge. We selected images showing large daily differences. The steps move vigorously at the upper 600m parts of the prodelta slope, so that we measured the steps in this area. From the profiles perpendicular to the bedwave crest lines through the center of channels, wavelength and wave height for each step, mean slope were measured on the software for quantitative image analyses manually. Wave steepness for each step was calculated using the wavelength and wave height measured as above. The mean slope ranges from 6.8° ~ 2.7° (more proximal, steeper), mean wavelength and wave heights of steps range from 24.5 to 87.6m

  11. Measurement of the total active 8B solar neutrino flux at the Sudbury Neutrino Observatory with enhanced neutral current sensitivity

    The Sudbury Neutrino Observatory (SNO) has precisely determined the total active (vx)8B solar neutrino flux without assumptions about the energy dependence of the ve survival probability. The measurements were made with dissolved NaCl in the heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21+-0.27 (stat)+-0.38(syst)x10-6 cm-2s-1, in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Δm2 = 7.1+1.2-0.6 x 10-5 eV2 and θ 32.5+2.4-2.3 degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations

  12. Local membrane deformations activate Ca2+-dependent K+ and anionic currents in intact human red blood cells

    Dyrda, Agnieszka; Cytlak, Urszula; Ciuraszkiewicz, Anna;

    2010-01-01

    flow, as well as the local membrane deformations generated in certain pathological conditions, such as sickle cell anemia, have been shown to increase membrane permeability, based largely on experimentation with red cell suspensions. We attempted here the first measurements of membrane currents......-activated transient PCa observed here under local membrane deformation is a likely contributor to the Ca(2+)-mediated effects observed during the normal aging process of red blood cells, and to the increased Ca(2+) content of red cells in certain hereditary anemias such as thalassemia and sickle cell anemia.......BACKGROUND: The mechanical, rheological and shape properties of red blood cells are determined by their cortical cytoskeleton, evolutionarily optimized to provide the dynamic deformability required for flow through capillaries much narrower than the cell's diameter. The shear stress induced by such...

  13. Measurement of the Total Active 8B Solar Neutrino Flux at the Sudbury Neutrino Observatory with Enhanced Neutral Current Sensitivity

    Ahmed, S N; Beier, E W; Bellerive, A; Biller, S D; Boger, J; Boulay, M G; Bowler, M G; Bowles, T J; Brice, S J; Bullard, T V; Chan, Y D; Chen, M; Chen, X; Cleveland, B T; Cox, G A; Dai, X; Dalnoki-Veress, F; Doe, P J; Dosanjh, R S; Doucas, G; Dragowsky, M R; Duba, C A; Duncan, F A; Dunford, M; Dunmore, J A; Earle, E D; Elliott, S R; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Fleurot, F; Formaggio, J A; Fowler, M M; Frame, K; Fulsom, B G; Gagnon, N; Graham, K; Grant, D R; Hahn, R L; Hall, J C; Hallin, A L; Hallman, E D; Hamer, A S; Handler, W B; Hargrove, C K; Harvey, P J; Hazama, R; Heeger, K M; Heintzelman, W J; Heise, J; Helmer, R L; Hemingway, R J; Hime, A; Howe, M A; Jagam, P; Jelley, N A; Klein, J R; Kos, M S; Krumins, A V; Kutter, T; Kyba, C C M; Labranche, H; Lange, R; Law, J; Lawson, I T; Lesko, K T; Leslie, J R; Levine, I; Luoma, S; MacLellan, R; Majerus, S; Mak, H B; Maneira, J; Marino, A D; McCauley, N; McDonald, A B; McGee, S; McGregor, G; Miin, C; Miknaitis, K K S; Miller, G G; Moffat, B A; Nally, C W; Nickel, B G; Noble, A J; Norman, E B; Oblath, N S; Okada, C E; Ollerhead, R W; Orrell, J L; Oser, S M; Ouellet, C V; Peeters, S J M; Poon, A W P; Robertson, B C; Robertson, R G H; Rollin, E; Rosendahl, S S E; Rusu, V L; Schwendener, M H; Simard, O; Simpson, J J; Sims, C J; Sinclair, D; Skensved, P; Smith, M W E; Starinsky, N; Stokstad, R G; Stonehill, L C; Tafirout, R; Takeuchi, Y; Tesic, G; Thomson, M; Thorman, M; Van Berg, R; Van de Water, R G; Virtue, C J; Wall, B L; Waller, D; Waltham, C E; Wan Chan Tseung, H; Wark, D L; West, N; Wilhelmy, J B; Wilkerson, J F; Wilson, J R; Wouters, J M; Yeh, M; Zuber, K

    2004-01-01

    The Sudbury Neutrino Observatory (SNO) has precisely determined the total active (nu_x) 8B solar neutrino flux without assumptions about the energy dependence of the nu_e survival probability. The measurements were made with dissolved NaCl in the heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27 (stat) +/- 0.38 (syst) x10^6 cm^{-2}s^{-1}, in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Delta m^{2} = 7.1^{+1.2}_{-0.6}x10^{-5} ev^2 and theta = 32.5^{+2.4}_{-2.3} degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

  14. Microstructural Degradation of Ni/YSZ Electrodes in Solid Oxide Electrolysis Cells under High Current

    Chen, Ming; Liu, Yi-Lin; Bentzen, Janet Jonna;

    2013-01-01

    current densities below −0.75 A/cm2. The formation of ZrO2 nano-particles deteriorates Ni percolation and presumably decreases the number of active triple phase boundaries (TPBs) and is therefore considered a degradation phenomenon. It is hypothesized that the degradation of the Ni surface is a result of...

  15. The weak currents

    The main facts known on the structure of the weak hadronic current are given. An attempt is made to elucidate the physical meaning of different hypotheses such as C.V.C., PCAC, SU(3) and angle theta, chiral algebra, which have led to progress in the understanding of weak interactions. The central problem to overcome in order to specify the structure of the hadronic current is the fact that gaps remain in the knowledge of strong interactions. However a solution has been found by assuming that the weak current is a combination of the currents associated with exact or approximate symmetries of strong interactions

  16. The missing matter problem: from the dark matter search to alternative hypotheses

    S. Capozziello; Consiglio, L.; Laurentis, M. De; De Rosa, G; Donato, C. Di

    2011-01-01

    Dark matter is among the most important open problems in both astrophysics and particle physics. We review the status of art of dark matter search at theoretical and experimental level discussing also alternative hypotheses.

  17. Remitted depression studies as tests of the cognitive vulnerability hypotheses of depression onset: a critique and conceptual analysis.

    Just, N; Abramson, L Y; Alloy, L B

    2001-02-01

    Investigations of cognitive patterns among individuals who have recovered from a depressive episode (i.e., remitted depressives) have figured importantly in evaluations of the validity of the vulnerability hypotheses of the cognitive theories of depression. However, we suggest that remitted depression studies as typically conducted and interpreted are inadequate tests of the cognitive vulnerability hypotheses of depression onset for four reasons: (1) remitted depression studies are based on the erroneous assumption that cognitive vulnerability should be an immutable trait; (2) remitted depression studies use a logically "backward" participant selection strategy in which participants are selected on the basis of the "dependent" variable (depression) and then compared on the "independent" variable (cognitive vulnerability), which is likely to result in heterogeneity of cognitive vulnerability among both the remitted depressed as well as the nondepressed groups given the causal relations specified in the cognitive theories of depression; (3) many remitted depression studies have ignored the possible activating role of stress in the cognitive vulnerability-stress theories, particularly Beck's theory, and thus, may attempt to assess cognitive vulnerability at a time when it is not operative (i.e., priming hypothesis); and (4) remitted depression studies inappropriately use postmorbid participants to test causal hypotheses, and therefore, are ambiguous about whether negative cognitive styles observed in remitted depressed persons are vulnerabilities as opposed to consequences of depression (i.e., scar hypothesis). As a remedy, we advocate the use of a theory-guided behavioral high-risk strategy to more adequately test the cognitive vulnerability hypotheses of depression onset. PMID:11148896

  18. BANKING INDUSTRY, MARKET STRUCTURE AND EFFICIENCY: THE REVISITED MODEL TO INTERMEDIARY HYPOTHESES

    Sami Mensi

    2011-01-01

    The object of this article is to propose a new conception of the structure-conductperformance/ efficient structure relationship. Alongside standard hypotheses, we retain two intermediary hypotheses, named modified efficient structure hypothesis and hybrid efficiency/collusion hypothesis. The models are estimated using a random effects estimating procedure over a sample of Tunisian commercial banks during the period 1990-2005. The results about the variable efficiency cannot reject the efficie...

  19. Sparsity hypotheses for robust estimation of the noise standard deviation in various signal processing applications.

    Pastor, Dominique; Socheleau, Franc¸ois-Xavier; Aïssa-El-Bey, Abdeldjalil

    2009-01-01

    This paper concerns the problem of estimating the noise standard deviation in different signal processing applications. The presented estimator derives from recent results in robust statistics based on sparsity hypotheses. More specifically, these theoretical results make the link between a standard problem in robust statistics (the estimation of the noise standard deviation in presence of outliers) and sparsity hypotheses. The estimator derived from these theoretical results can be applied t...

  20. All in the Family: Comparing Siblings to Test Causal Hypotheses Regarding Environmental Influences on Behavior

    Lahey, Benjamin B.; D’Onofrio, Brian M

    2010-01-01

    Psychologists in both basic and applied fields are keenly interested in the environmental influences that shape our lives. Therefore, researchers test causal hypotheses to construct models of environmental influences that can withstand attempts at refutation. Randomized experiments provide the strongest tests of causal hypotheses, but are not always feasible and their assumptions cannot always be met. In such cases, a number of quasi-experimental research designs can be used to substantially ...

  1. Changing paradigms in cranio-facial regeneration: current and new strategies for the activation of endogenous stem cells

    Luigi eMele

    2016-02-01

    Full Text Available Craniofacial area represent a unique district of human body characterized by a very high complexity of tissues, innervation and vascularization, and being deputed to many fundamental function such as eating, speech, expression of emotions, delivery of sensations such as taste, sight and earing. For this reasons, tissue loss in this area following trauma or for example oncologic resection, have a tremendous impact on patients’ quality of life. In the last 20 years regenerative medicine has emerged as one of the most promising approach to solve problem related to trauma, tissue loss, organ failure etc. One of the most powerful tools to be used for tissue regeneration is represented by stem cells, which have been successfully implanted in different tissue/organs with exciting results. Nevertheless both autologous and allogeneic stem cell transplantation raise many practical and ethical concerns that make this approach very difficult to apply in clinical practice. For this reason different cell free approaches have been developed aiming to the mobilization, recruitment and activation of endogenous stem cells into the injury site avoiding exogenous cells implant but instead stimulating patients’ own stem cells to repair the lesion. To this aim many strategies have been used including functionalized bioscaffold, controlled release of stem cell chemoattractants, growth factors, BMPs, Platelet–Rich-Plasma and other new strategies such as ultrasound wave and laser are just being proposed. Here we review all the current and new strategies used for activation and mobilization of endogenous stem cells in the regeneration of craniofacial tissue.

  2. Changing Paradigms in Cranio-Facial Regeneration: Current and New Strategies for the Activation of Endogenous Stem Cells.

    Mele, Luigi; Vitiello, Pietro Paolo; Tirino, Virginia; Paino, Francesca; De Rosa, Alfredo; Liccardo, Davide; Papaccio, Gianpaolo; Desiderio, Vincenzo

    2016-01-01

    Craniofacial area represent a unique district of human body characterized by a very high complexity of tissues, innervation and vascularization, and being deputed to many fundamental function such as eating, speech, expression of emotions, delivery of sensations such as taste, sight, and earing. For this reasons, tissue loss in this area following trauma or for example oncologic resection, have a tremendous impact on patients' quality of life. In the last 20 years regenerative medicine has emerged as one of the most promising approach to solve problem related to trauma, tissue loss, organ failure etc. One of the most powerful tools to be used for tissue regeneration is represented by stem cells, which have been successfully implanted in different tissue/organs with exciting results. Nevertheless, both autologous and allogeneic stem cell transplantation raise many practical and ethical concerns that make this approach very difficult to apply in clinical practice. For this reason different cell free approaches have been developed aiming to the mobilization, recruitment, and activation of endogenous stem cells into the injury site avoiding exogenous cells implant but instead stimulating patients' own stem cells to repair the lesion. To this aim many strategies have been used including functionalized bioscaffold, controlled release of stem cell chemoattractants, growth factors, BMPs, Platelet-Rich-Plasma, and other new strategies such as ultrasound wave and laser are just being proposed. Here we review all the current and new strategies used for activation and mobilization of endogenous stem cells in the regeneration of craniofacial tissue. PMID:26941656

  3. Reward-related dorsal striatal activity differences between former and current cocaine dependent individuals during an interactive competitive game.

    Hyatt, Christopher J; Assaf, Michal; Muska, Christine E; Rosen, Rivkah I; Thomas, Andre D; Johnson, Matthew R; Hylton, Jennifer L; Andrews, Melissa M; Reynolds, Brady A; Krystal, John H; Potenza, Marc N; Pearlson, Godfrey D

    2012-01-01

    Cocaine addiction is characterized by impulsivity, impaired social relationships, and abnormal mesocorticolimbic reward processing, but their interrelationships relative to stages of cocaine addiction are unclear. We assessed blood-oxygenation-level dependent (BOLD) signal in ventral and dorsal striatum during functional magnetic resonance imaging (fMRI) in current (CCD; n = 30) and former (FCD; n = 28) cocaine dependent subjects as well as healthy control (HC; n = 31) subjects while playing an interactive competitive Domino game involving risk-taking and reward/punishment processing. Out-of-scanner impulsivity-related measures were also collected. Although both FCD and CCD subjects scored significantly higher on impulsivity-related measures than did HC subjects, only FCD subjects had differences in striatal activation, specifically showing hypoactivation during their response to gains versus losses in right dorsal caudate, a brain region linked to habituation, cocaine craving and addiction maintenance. Right caudate activity in FCD subjects also correlated negatively with impulsivity-related measures of self-reported compulsivity and sensitivity to reward. These findings suggest that remitted cocaine dependence is associated with striatal dysfunction during social reward processing in a manner linked to compulsivity and reward sensitivity measures. Future research should investigate the extent to which such differences might reflect underlying vulnerabilities linked to cocaine-using propensities (e.g., relapses). PMID:22606228

  4. Changing Paradigms in Cranio-Facial Regeneration: Current and New Strategies for the Activation of Endogenous Stem Cells

    Mele, Luigi; Vitiello, Pietro Paolo; Tirino, Virginia; Paino, Francesca; De Rosa, Alfredo; Liccardo, Davide; Papaccio, Gianpaolo; Desiderio, Vincenzo

    2016-01-01

    Craniofacial area represent a unique district of human body characterized by a very high complexity of tissues, innervation and vascularization, and being deputed to many fundamental function such as eating, speech, expression of emotions, delivery of sensations such as taste, sight, and earing. For this reasons, tissue loss in this area following trauma or for example oncologic resection, have a tremendous impact on patients' quality of life. In the last 20 years regenerative medicine has emerged as one of the most promising approach to solve problem related to trauma, tissue loss, organ failure etc. One of the most powerful tools to be used for tissue regeneration is represented by stem cells, which have been successfully implanted in different tissue/organs with exciting results. Nevertheless, both autologous and allogeneic stem cell transplantation raise many practical and ethical concerns that make this approach very difficult to apply in clinical practice. For this reason different cell free approaches have been developed aiming to the mobilization, recruitment, and activation of endogenous stem cells into the injury site avoiding exogenous cells implant but instead stimulating patients' own stem cells to repair the lesion. To this aim many strategies have been used including functionalized bioscaffold, controlled release of stem cell chemoattractants, growth factors, BMPs, Platelet–Rich-Plasma, and other new strategies such as ultrasound wave and laser are just being proposed. Here we review all the current and new strategies used for activation and mobilization of endogenous stem cells in the regeneration of craniofacial tissue. PMID:26941656

  5. Reward-related dorsal striatal activity differences between former and current cocaine dependent individuals during an interactive competitive game.

    Christopher J Hyatt

    Full Text Available Cocaine addiction is characterized by impulsivity, impaired social relationships, and abnormal mesocorticolimbic reward processing, but their interrelationships relative to stages of cocaine addiction are unclear. We assessed blood-oxygenation-level dependent (BOLD signal in ventral and dorsal striatum during functional magnetic resonance imaging (fMRI in current (CCD; n = 30 and former (FCD; n = 28 cocaine dependent subjects as well as healthy control (HC; n = 31 subjects while playing an interactive competitive Domino game involving risk-taking and reward/punishment processing. Out-of-scanner impulsivity-related measures were also collected. Although both FCD and CCD subjects scored significantly higher on impulsivity-related measures than did HC subjects, only FCD subjects had differences in striatal activation, specifically showing hypoactivation during their response to gains versus losses in right dorsal caudate, a brain region linked to habituation, cocaine craving and addiction maintenance. Right caudate activity in FCD subjects also correlated negatively with impulsivity-related measures of self-reported compulsivity and sensitivity to reward. These findings suggest that remitted cocaine dependence is associated with striatal dysfunction during social reward processing in a manner linked to compulsivity and reward sensitivity measures. Future research should investigate the extent to which such differences might reflect underlying vulnerabilities linked to cocaine-using propensities (e.g., relapses.

  6. Current and calcium responses to local activation of axonal NMDA receptors in developing cerebellar molecular layer interneurons.

    Bénédicte Rossi

    Full Text Available In developing cerebellar molecular layer interneurons (MLIs, NMDA increases spontaneous GABA release. This effect had been attributed to either direct activation of presynaptic NMDA receptors (preNMDARs or an indirect pathway involving activation of somato-dendritic NMDARs followed by passive spread of somatic depolarization along the axon and activation of axonal voltage dependent Ca(2+ channels (VDCCs. Using Ca(2+ imaging and electrophysiology, we searched for preNMDARs by uncaging NMDAR agonists either broadly throughout the whole field or locally at specific axonal locations. Releasing either NMDA or glutamate in the presence of NBQX using short laser pulses elicited current transients that were highly sensitive to the location of the spot and restricted to a small number of varicosities. The signal was abolished in the presence of high Mg(2+ or by the addition of APV. Similar paradigms yielded restricted Ca(2+ transients in interneurons loaded with a Ca(2+ indicator. We found that the synaptic effects of NMDA were not inhibited by blocking VDCCs but were impaired in the presence of the ryanodine receptor antagonist dantrolene. Furthermore, in voltage clamped cells, bath applied NMDA triggers Ca(2+ elevations and induces neurotransmitter release in the axonal compartment. Our results suggest the existence of preNMDARs in developing MLIs and propose their involvement in the NMDA-evoked increase in GABA release by triggering a Ca(2+-induced Ca(2+ release process mediated by presynaptic Ca(2+ stores. Such a mechanism is likely to exert a crucial role in various forms of Ca(2+-mediated synaptic plasticity.

  7. Testing hypotheses of soil organic matter dynamics in a mechanistic reactive transport model

    Riley, W. J.; Maggi, F.; Guerry, N.; Torn, M. S.; Kleber, M.

    2012-12-01

    The range of processes hypothesized to be important for long-term soil organic matter dynamics far exceeds the capabilities of current land models integrated in regional- to global-scale climate models. Yet SOM stability and CO2 fluxes from soils to the atmosphere are critical for future projections of climate. Recent syntheses of processes that may influence the trajectory of future soil C storage emphasize mineral interactions, enzyme dynamics, microbial population dynamics, transport, and interactions with plants and nutrient cycles. We contend that evaluating the relative importance of these processes requires a numerical modelling structure that allows for consistent comparison with observations, uncertainty characterization, and as mechanistic as possible a representation of the processes. We will describe a detailed spatially-resolved 3-dimensional reactive transport solver (TOUGHREACT) that represents abiotic and biotic SOM transformations and multi-phase flows. The modelling framework allows for explicit representation of (1) SOM interactions with minerals and their temperature, pH, and redox dependencies; (2) multiple microbial groups with different survival strategies and environmental sensitivities; (3) aqueous, gaseous, and sorbed phases; and (4) disaggregation of litter inputs, depolymerisation productions, and microbial bodies into an arbitrary number of SOM functional groups. The model accurately represented vertically-resolved bulk SOM in grassland and forest ecosystems using a baseline set of parameters. After testing, we used the model to investigate the relative impact of various mechanisms affecting SOM storage. Model predictions highlight the importance of sorption, aqueous transport, and microbial dynamics for the slow turnover of SOM that is observed below the rooting zone. We will also describe (1) model structural and parametric uncertainty; (2) methods to extract low-order model representations from the detailed reactive transport

  8. Call transmission efficiency in native and invasive anurans: competing hypotheses of divergence in acoustic signals.

    Llusia, Diego; Gómez, Miguel; Penna, Mario; Márquez, Rafael

    2013-01-01

    Invasive species are a leading cause of the current biodiversity decline, and hence examining the major traits favouring invasion is a key and long-standing goal of invasion biology. Despite the prominent role of the advertisement calls in sexual selection and reproduction, very little attention has been paid to the features of acoustic communication of invasive species in nonindigenous habitats and their potential impacts on native species. Here we compare for the first time the transmission efficiency of the advertisement calls of native and invasive species, searching for competitive advantages for acoustic communication and reproduction of introduced taxa, and providing insights into competing hypotheses in evolutionary divergence of acoustic signals: acoustic adaptation vs. morphological constraints. Using sound propagation experiments, we measured the attenuation rates of pure tones (0.2-5 kHz) and playback calls (Lithobates catesbeianus and Pelophylax perezi) across four distances (1, 2, 4, and 8 m) and over two substrates (water and soil) in seven Iberian localities. All factors considered (signal type, distance, substrate, and locality) affected transmission efficiency of acoustic signals, which was maximized with lower frequency sounds, shorter distances, and over water surface. Despite being broadcast in nonindigenous habitats, the advertisement calls of invasive L. catesbeianus were propagated more efficiently than those of the native species, in both aquatic and terrestrial substrates, and in most of the study sites. This implies absence of optimal relationship between native environments and propagation of acoustic signals in anurans, in contrast to what predicted by the acoustic adaptation hypothesis, and it might render these vertebrates particularly vulnerable to intrusion of invasive species producing low frequency signals, such as L. catesbeianus. Our findings suggest that mechanisms optimizing sound transmission in native habitat can play a less

  9. Sliding mode controller for four leg shunt active power filter to eliminating zero sequence current, compensating harmonics and reactive power with fixed switching frequency

    Chebabhi Ali

    2015-01-01

    Full Text Available In this paper, the four leg inverter controlled by the three dimensional space vector modulation (3D SVM is used as the shunt active power filter (SAPF for compensating the three phase four wire electrical network, by using the four leg inverter with 3D SVM advantages to eliminated zero sequence current, fixed switching frequency of inverter switches, and reduced switching losses. This four leg inverter is employed as shunt active power filter to minimizing harmonic currents, reducing magnitude of neutral wire current, eliminating zero sequence current caused by nonlinear single phase loads and compensating reactive power, and a nonlinear sliding mode control technique (SMC is proposed for harmonic currents and DC bus voltage control to improve the performances of the three phase four wire four leg shunt active power filter based on Synchronous Reference Frame (SRF theory in the dq0 axes, and to decoupling the four leg SAPF mathematical model.

  10. Daydreaming style moderates the relation between working memory and mind wandering: Integrating two hypotheses.

    Marcusson-Clavertz, David; Cardeña, Etzel; Terhune, Devin Blair

    2016-01-01

    Mind wandering—mentation unrelated to one’s current activity and surroundings—is a ubiquitous phenomenon, but seemingly competing ideas have been proposed regarding its relation to executive cognitive processes. The control-failure hypothesis postulates that executive processes prevent mind wandering, whereas the global availability hypothesis proposes that mind wandering requires executive resources, and thus an excess of such resources enables mind wandering. Here, we examined whether these...

  11. Active induction balance method for metal detector sensing head utilizing transmitter-bucking and dual current source

    A central problem in a design of frequency domain electromagnetic induction sensors used in landmine detection is an effective suppression of a direct inductive coupling between the transmitter and the receiver coil (induction balance, IB). In sensing heads based on the transmitter-bucking configuration, IB is achieved by using two concentric transmitter coils with opposing exciter fields in order to create a central magnetic cavity for the receiver coil. This design has numerous advantages over other IB methods in terms of detection sensitivity, spatial resolution, sensor dimensions and suitability for model-based measurements. However, very careful design and precise sensing head geometry are required if a single excitation source is used for driving both transmitter coils. In this paper we analyze the IB sensitivity to small perturbations of geometrical properties of coils. We propose a sensor design with dual current source and active induction balance scheme which overcomes the limitations of geometry-based balancing and potentially provides more efficient compensation of soil effects.

  12. Significance exaggerated of the activity of the construction in Spain; inflection and current decline? The difficult to their sostenibilitiy

    José María Serrano

    2010-04-01

    Full Text Available For some time the activity of the construction, in its different sections, (housings, works with non residential ends, transport, public works… has had special significance inside the productive system in Spain. During the last decade it has reached an exaggerated weight, so much in their participation in the GDP like of people occupied in her. The some regions that proportion represents exaggerated ends. The current economic crisis has affected with intensity to the group of the sector of the construction, making more intense the consequences of the economic recession. Everything it, is not only as a consequence of a crisis of the situation. Rather she is due to structural reasons. It seems probable that, from now on, the group of the Spanish economic system, it should be articulated with a new organization, a new productive model, where the construction only means a more reduced part of the same one. That is easy to say, but very difficult of getting it. It represents a great challenge face to the future.

  13. Antimigraine drug, zolmitriptan, inhibits high-voltage activated calcium currents in a population of acutely dissociated rat trigeminal sensory neurons

    Matsuzawa Yoshiyasu

    2006-03-01

    Full Text Available Abstract Background Triptans, 5-HT1B/ID agonists, act on peripheral and/or central terminals of trigeminal ganglion neurons (TGNs and inhibit the release of neurotransmitters to second-order neurons, which is considered as one of key mechanisms for pain relief by triptans as antimigraine drugs. Although high-voltage activated (HVA Ca2+ channels contribute to the release of neurotransmitters from TGNs, electrical actions of triptans on the HVA Ca2+ channels are not yet documented. Results In the present study, actions of zolmitriptan, one of triptans, were examined on the HVA Ca2+ channels in acutely dissociated rat TGNs, by using whole-cell patch recording of Ba2+ currents (IBa passing through Ca2+ channels. Zolmitriptan (0.1–100 μM reduced the size of IBa in a concentration-dependent manner. This zolmitriptan-induced inhibitory action was blocked by GR127935, a 5-HT1B/1D antagonist, and by overnight pretreatment with pertussis toxin (PTX. P/Q-type Ca2+ channel blockers inhibited the inhibitory action of zolmitriptan on IBa, compared to N- and L-type blockers, and R-type blocker did, compared to L-type blocker, respectively (p 1B/1D receptor linked to Gi/o pathway. Conclusion It is concluded that this zolmitriptan inhibition of HVA Ca2+ channels may explain the reduction in the release of neurotransmitters including CGRP, possibly leading to antimigraine effects of zolmitriptan.

  14. R and D appropriability, opportunity, and market structure: new evidence on some Schumpeterian hypotheses

    Levin, R.C.; Cohen, W.M.; Mowery, D.C.

    1985-05-01

    One of the largest bodies of literature in the field of industrial organization is devoted to the interpretation and testing of several hypotheses advanced by Joseph Schumpeter (1950) concerning innovation and industrial market structure. One set of hypotheses focuses on the role of firm size as a determinant of R and D spending and the rate of technological advance. Another set focuses on the effect of market concentration on R and D and technological advance. In this paper, the latter set of hypotheses is reexamined at the industry level, using new data on R and D appropriability and technological opportunity collected by Leven et al. (1984) in a survey of R and D executives in 130 industries. 6 references.

  15. Healthy migrant and salmon bias hypotheses: a study of health and internal migration in China.

    Lu, Yao; Qin, Lijian

    2014-02-01

    The existing literature has often underscored the "healthy migrant" effect and the "salmon bias" in understanding the health of migrants. Nevertheless, direct evidence for these two hypotheses, particularly the "salmon bias," is limited. Using data from a national longitudinal survey conducted between 2003 and 2007 in China, we provide tests of these hypotheses in the case of internal migration in China. To examine the healthy migrant effect, we study how pre-migration self-reported health is associated with an individual's decision to migrate and the distance of migration. To test the salmon bias hypothesis, we compare the self-reported health of migrants who stay in destinations and who return or move closer to home villages. The results provide support for both hypotheses. Specifically, healthier individuals are more likely to migrate and to move further away from home. Among migrants, those with poorer health are more likely to return or to move closer to their origin communities. PMID:24565140

  16. A New Robust Decoupled Control of the Stator Active and Reactive Currents for Grid-Connected Doubly-Fed Induction Generators

    Ahmad Bashar Ataji; Yushi Miura; Toshifumi Ise; Hiroki Tanaka

    2016-01-01

    This paper addresses the grid-connected variable speed doubly-fed induction generator, and proposes a new decoupled control to replace the conventional decoupled active and reactive powers (P-Q) control. The proposed decoupled control is based on decoupling the stator active and reactive currents, in contrast with the conventional decoupled P-Q control, which is based on decoupling the stator active and reactive powers by forcing the stator d- or q-voltage to zero. The proposed decoupled cont...

  17. MLE of capability index Cp and its application in testing hypotheses

    Michálek, Jiří

    Cagliari, Sardinie : TILAPIA Communications, 2009 - (Mola, F.; Conversano, C.; Vinzi, V.; Fisher, N.). s. 46-47 ISBN 978-88-89744-13-0. [EURISBIS 09. European Regional Meeting of International Society for Business and Industrial Statistics. 30.05.2009-03.06.2009, Cagliari] R&D Projects: GA MŠk(CZ) 1M06047 Institutional research plan: CEZ:AV0Z10750506 Keywords : Capability index Cp * Maximal likelihood estimate * Testing hypotheses Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2009/SI/michalek-mle of capability index cp and its application in testing hypotheses.pdf

  18. Study design, objectives, hypotheses, main findings, health consequences for the population exposed, rationale of future research

    Trnovec, T.; Kocan, A. [Slovak Medical Univ., Bratislava (Slovakia); Bencko, V. [Charles Univ., Prague (Czech Republic); Langer, P. [Institute of Experimental Endocrinology SAS, Bratislava (Slovakia); Berg, M. van den [Rijksuniversiteit Utrecht (Netherlands); Bergman, A. [Stockholm Univ. (Sweden); Hustak, M. [Air Force Military Hospital, Kosics (Slovakia)

    2004-09-15

    In Slovakia, the Chemko Chemical Company, based in Strazske, in the Michalovce district, produced PCBs between 1959 and 1984, in the amount of more than 21,000 tons of commercial mixtures (Delor 103, 104, 105, 106, Delotherm DK and DH, Hydelor 137). PCBs were used for similar industrial purposes as in the west. Improper disposal from the Chemko plant via release of effluent directly into the Laborec River resulted in long-term contamination of sediment. As a result eastern Slovakia, the Michalovce district in particular, is recognized as one of the areas all over the world most heavily polluted with PCBs. Historical studies show that blood and adipose PCB levels were higher in Czechoslovakia than elsewhere in the 1970's and 1980's. Current data indicate that persons who eat locally raised food - pork, beef, poultry, eggs - in this district have elevated serum concentrations of PCBs. Environmental exposure to organochlorines in the Michalovce district indicate association with higher rates of certain cancers, but an inverse association with risk of breast cancer. An increased prevalence of thyroid disorders in the polluted area was also reported. This ''experimental setting in nature'' has attracted international scientific teams and two projects in the area are ongoing: Evaluating Human Health Risk from Low-dose and Long-term PCB Exposure, 5{sup th} FP Project QLK4-2000-00488, 2001- 2004; PCBRISK (http://www.pcbrisk.sk/) and Early Childhood Development and PCB Exposures in Slovakia, NCI/NIH, R01-CA96525 University of California, Davis, USA. This paper is serving as an introduction to papers of a session reporting on various health outcomes associated with PCB exposure. The objectives of the PCBRISK project were targeted at an evaluation of the human health risks of low-dose and long-term exposure to a group of persistent organochlorine pollutants, including polychlorinated biphenyls (PCBs) and their metabolites, organochlorine

  19. Why are Nitrogen Concentrations in Plant Tissues Lower under Elevated CO2? A Critical Examination of the Hypotheses

    Daniel R. Taub; Xianzhong Wang

    2008-01-01

    Plants grown under elevated atmospheric [CO2] typically have decreased tissue concentrations of N compared with plants grown under current ambient [CO2]. The physiological mechanisms responsible for this phenomenon have not been definitely established, although a considerable number of hypotheses have been advanced to account for it. In this review we discuss and critically evaluate these hypotheses. One contributing factor to the decreases in tissue N concentrations clearly is dilution of N by increased photosynthetic assimilation of C. In addition, studies on intact plants show strong evidence for a general decrease in the specific uptake rates (uptake per unit mass or length of root) of N by roots under elevated CO2. This decreased root uptake appears likely to be the result both of decreased N demand by shoots and of decreased ability of the soil-root system to supply N. The best-supported mechanism for decreased N supply is a decrease in transpiration-driven mass flow of N in soils due to decreased stomatal conductance at elevated CO2, although some evidence suggests that altered root system architecture may also play a role. There is also limited evidence suggesting that under elevated CO2, plants may exhibit increased rates of N loss through volatilization and/or root exudation, further contributing to lowering tissue N concentrations.

  20. Effects of unsaturated fatty acids on calcium-activated potassium current in gastric myocytes of guinea pigs

    Hai-Feng Zheng; Xiang-Lan Li; Zheng-Yuan Jin; Jia-Bin Sun; Zai-Liu Li; Wen-Xie Xu

    2005-01-01

    AIM: To investigate the effects of exogenous unsaturated fatty acids on calcium-activated potassium current [Ik(Ca)]in gastric antral circular myocytes of guinea pigs.METHODS: Gastric myocytes were isolated by collagenase from the antral circular layer of guinea pig stomach. The whole-cell patch clamp technique was used to record Ik(Ca)in the isolated single smooth muscle cells with or without different concentrations of arachidonic acid (AA), linoleic acid (LA), and oleic acid (OA).RESULTS: AA at concentrations of 2,5 and 10 μmol/L markedly increased IK(ca)in a dose-dependent manner. LA at concentrations of 5, 10 and 20 μmol/L also enhanced IK(Ca)in a dose-dependent manner. The increasing potency of AA, LA, and oleic acid (OA) on Ik(Ca) at the same concentration(10 μmol/L) was in the order of AA>LA>OA. AA (10 μmol/L)-induced increase of Ik(Ca) was not blocked by H-7 (10 μmol/L), an inhibitor of protein kinase C (PKC), or indomethacin (10 μmol/L),an inhibitor of the cyclooxygenase pathway, and 17-octadecynoic acid (10 μmol/L), an inhibitor of the cytochrome P450 pathway, but weakened by nordihydroguaiaretic acid(10 μmol/L), an inhibitor of the lipoxygenase pathway.CONCLUSION: Unsaturated fatty acids markedly increase Ik(Ca), and the enhancing potencies are related to the number of double bonds in the fatty acid chain. The lipoxygenase pathway of unsaturated fatty acid metabolism is involved in the unsaturated fatty acid-induced increase of IK(Ca) in gastric antral circular myocytes of guinea pigs.

  1. Transcranial direct current stimulation over the supplementary motor area modulates the preparatory activation level in the human motor system

    Carlsen, Anthony N.; Eagles, Jeremy S.; MacKinnon, Colum D.

    2016-01-01

    Transcranial direct current stimulation (tDCS) is a non-invasive stimulation method that can induce transient polarity-specific neuroplastic changes in cortical excitability lasting up to 1 h post-stimulation. While excitability changes with stimulation over the primary motor cortex have been well documented, the functional effects of stimulation over premotor regions are less well understood. In the present experiment, we tested how cathodal and anodal tDCS applied over the region of the supplementary motor area (SMA) affected preparation and initiation of a voluntary movement. Participants performed a simple reaction time (RT) task requiring a targeted wrist-extension in response to a go-signal. In 20% of RT trials a startling acoustic stimulus (SAS) was presented 500 ms prior to the “go” signal in order to probe the state of motor preparation. Following the application of cathodal, anodal, or sham tDCS (separate days) over SMA for 10 min, participants performed blocks of RT trials at 10 min intervals. While sham stimulation did not affect RT or incidence of early release by the SAS, cathodal tDCS led to a significant slowing of RT that peaked 10 min after the end of stimulation and was associated with a marked decrease in the incidence of movement release by the SAS. In contrast, anodal tDCS resulted in faster RTs, but the incidence of release was unchanged. These results are consistent with the SMA playing a role in the pre-planning of movements and that modulating its activity with tDCS can lead to polarity-specific changes in motor behavior. PMID:25446764

  2. Effect of gating currents of ion channels on the collective spiking activity of coupled Hodgkin-Huxley neurons

    2009-01-01

    Based on the coupled stochastic Hodgkin-Huxley neurons, we numerically studied the effect of gating currents of ion channels, as well as coupling and the number of neurons, on the collective spiking rate and regularity in the coupled system. It was found, for a given coupling strength and with a relatively large number of neurons, when gating currents are applied, the collective spiking regularity decreases; meanwhile, the collective spiking rate increases, indicating that gating currents can aggravate the de-synchronization of the spikings of all neurons. However, gating currents caused hardly any effect in the spiking of any individual neuron of the coupled system. This result, different from the reduction of the spiking rate by gating currents in a single neuron, provides a new insight into the effect of gating cur-rents on the global information processing and signal transduction in real neural systems.

  3. Pharmacological Analysis of the Activation and Receptor Properties of the Tonic GABACR Current in Retinal Bipolar Cell Terminals

    Jones, Stefanie M.; Palmer, Mary J

    2011-01-01

    GABAergic inhibition in the central nervous system (CNS) can occur via rapid, transient postsynaptic currents and via a tonic increase in membrane conductance, mediated by synaptic and extrasynaptic GABA(A) receptors (GABA(A)Rs) respectively. Retinal bipolar cells (BCs) exhibit a tonic current mediated by GABA(C)Rs in their axon terminal, in addition to synaptic GABA(A)R and GABA(C)R currents, which strongly regulate BC output. The tonic GABA(C)R current in BC terminals (BCTs) is not dependen...

  4. Conditional knockout of TMEM16A/anoctamin1 abolishes the calcium-activated chloride current in mouse vomeronasal sensory neurons.

    Amjad, Asma; Hernandez-Clavijo, Andres; Pifferi, Simone; Maurya, Devendra Kumar; Boccaccio, Anna; Franzot, Jessica; Rock, Jason; Menini, Anna

    2015-04-01

    Pheromones are substances released from animals that, when detected by the vomeronasal organ of other individuals of the same species, affect their physiology and behavior. Pheromone binding to receptors on microvilli on the dendritic knobs of vomeronasal sensory neurons activates a second messenger cascade to produce an increase in intracellular Ca(2+) concentration. Here, we used whole-cell and inside-out patch-clamp analysis to provide a functional characterization of currents activated by Ca(2+) in isolated mouse vomeronasal sensory neurons in the absence of intracellular K(+). In whole-cell recordings, the average current in 1.5 µM Ca(2+) and symmetrical Cl(-) was -382 pA at -100 mV. Ion substitution experiments and partial blockade by commonly used Cl(-) channel blockers indicated that Ca(2+) activates mainly anionic currents in these neurons. Recordings from inside-out patches from dendritic knobs of mouse vomeronasal sensory neurons confirmed the presence of Ca(2+)-activated Cl(-) channels in the knobs and/or microvilli. We compared the electrophysiological properties of the native currents with those mediated by heterologously expressed TMEM16A/anoctamin1 or TMEM16B/anoctamin2 Ca(2+)-activated Cl(-) channels, which are coexpressed in microvilli of mouse vomeronasal sensory neurons, and found a closer resemblance to those of TMEM16A. We used the Cre-loxP system to selectively knock out TMEM16A in cells expressing the olfactory marker protein, which is found in mature vomeronasal sensory neurons. Immunohistochemistry confirmed the specific ablation of TMEM16A in vomeronasal neurons. Ca(2+)-activated currents were abolished in vomeronasal sensory neurons of TMEM16A conditional knockout mice, demonstrating that TMEM16A is an essential component of Ca(2+)-activated Cl(-) currents in mouse vomeronasal sensory neurons. PMID:25779870

  5. Local alternatives in testing hypotheses on parameters of Gibbs random fields

    Janžura, Martin

    Lisabon : ISI, 2007, s. 1117-1117. [Session of the International Statistical Institute /56./. Lisabon (PT), 22.08.2007-29.08.2007] R&D Projects: GA ČR GA201/06/1323 Institutional research plan: CEZ:AV0Z10750506 Keywords : testing hypotheses * local alternative * Gibbs random fields Subject RIV: BA - General Mathematics

  6. Williams Syndrome Hypersociability: A Neuropsychological Study of the Amygdala and Prefrontal Cortex Hypotheses

    Capitao, Liliana; Sampaio, Adriana; Fernandez, Montse; Sousa, Nuno; Pinheiro, Ana; Goncalves, Oscar F.

    2011-01-01

    Individuals with Williams syndrome display indiscriminate approach towards strangers. Neuroimaging studies conducted so far have linked this social profile to structural and/or functional abnormalities in WS amygdala and prefrontal cortex. In this study, the neuropsychological hypotheses of amygdala and prefrontal cortex involvement in WS…

  7. A Refined Computer Harassment Paradigm: Validation, and Test of Hypotheses about Target Characteristics

    Siebler, Frank; Sabelus, Saskia; Bohner, Gerd

    2008-01-01

    A refined computer paradigm for assessing sexual harassment is presented, validated, and used for testing substantive hypotheses. Male participants were given an opportunity to send sexist jokes to a computer-simulated female chat partner. In Study 1 (N = 44), the harassment measure (number of sexist jokes sent) correlated positively with…

  8. Investigating Moderator Hypotheses in Aging Research: Statistical, Methodological, and Conceptual Difficulties with Comparing Separate Regressions

    Newsom, Jason T.; Prigerson, Holly G.; Schulz, Richard; Reynolds, Charles F., III

    2003-01-01

    Many topics in aging research address questions about group differences in prediction. Such questions can be viewed in terms of interaction or moderator effects, and use of appropriate methods to test these hypotheses are necessary to arrive at accurate conclusions about age differences. This article discusses the conceptual, methodological, and…

  9. Testing Alternative Hypotheses Regarding the Association between Behavioral Inhibition and Language Development in Toddlerhood

    Watts, Ashley K. Smith; Patel, Deepika; Corley, Robin P.; Friedman, Naomi P.; Hewitt, John K.; Robinson, JoAnn L.; Rhee, Soo H.

    2014-01-01

    Studies have reported an inverse association between language development and behavioral inhibition or shyness across childhood, but the direction of this association remains unclear. This study tested alternative hypotheses regarding this association in a large sample of toddlers. Data on behavioral inhibition and expressive and receptive…

  10. Support for major hypotheses in invasion biology is uneven and declining

    Jeschke, J.M.; Aparicio, L.G.; Haider, S.; Heger, T.; Lortie, C. J.; Pyšek, Petr; Strayer, D.L.

    2012-01-01

    Roč. 2012, č. 14 (2012), s. 1-20. ISSN 1619-0033 R&D Projects: GA ČR(CZ) GAP504/11/1028 Institutional support: RVO:67985939 Keywords : biological invasions * hypotheses * testing Subject RIV: EF - Botanics

  11. Improving the Readability of ASR Results for Lectures Using Multiple Hypotheses and Sentence-Level Knowledge

    Fujii, Yasuhisa; Yamamoto, Kazumasa; Nakagawa, Seiichi

    This paper presents a novel method for improving the readability of automatic speech recognition (ASR) results for classroom lectures. Because speech in a classroom is spontaneous and contains many ill-formed utterances with various disfluencies, the ASR result should be edited to improve the readability before presenting it to users, by applying some operations such as removing disfluencies, determining sentence boundaries, inserting punctuation marks and repairing dropped words. Owing to the presence of many kinds of domain-dependent words and casual styles, even state-of-the-art recognizers can only achieve a 30-50% word error rate for speech in classroom lectures. Therefore, a method for improving the readability of ASR results is needed to make it robust to recognition errors. We can use multiple hypotheses instead of the single-best hypothesis as a method to achieve a robust response to recognition errors. However, if the multiple hypotheses are represented by a lattice (or a confusion network), it is difficult to utilize sentence-level knowledge, such as chunking and dependency parsing, which are imperative for determining the discourse structure and therefore imperative for improving readability. In this paper, we propose a novel algorithm that infers clean, readable transcripts from spontaneous multiple hypotheses represented by a confusion network while integrating sentence-level knowledge. Automatic and manual evaluations showed that using multiple hypotheses and sentence-level knowledge is effective to improve the readability of ASR results, while preserving the understandability.

  12. Utility of Krashen's Five Hypotheses in the Saudi Context of Foreign Language Acquisition/Learning

    Gulzar, Malik Ajmal; Gulnaz, Fahmeeda; Ijaz, Attiya

    2014-01-01

    In the last twenty years, the paradigm that has dominated the discipline of language teaching is the SLA theory and Krashen's five hypotheses which are still proving flexible to accommodate earlier reforms. This paper reviews second language acquisition (SLA) theory to establish an understanding of its role in the EFL/ESL classrooms. Other areas…

  13. Lee Smolin Five Great Problems and Their Solution without Ontological Hypotheses

    Quznetsov G.

    2011-01-01

    Full Text Available Solutions of Lee Smolin Five Great Problems from his book The Trouble with Physics: the Rise of String Theory, the Fall of a Science, and What Comes Next are described. These solutions are obtained only from the properties of probability without any ontological hypotheses.

  14. Lee Smolin Five Great Problems and Their Solution without Ontological Hypotheses

    Quznetsov G.

    2011-01-01

    Solutions of Lee Smolin Five Great Problems from his book {\\it The Trouble with Physics: the Rise of String Theory, the Fall of a Science, and What Comes Next} are described. This solutions is obtained only from the properties of probability without any ontological hypotheses.

  15. Lee Smolin Five Great Problems and Their Solution without Ontological Hypotheses

    Quznetsov G.

    2011-01-01

    Full Text Available Solutions of Lee Smolin Five Great Problems from his book The Trouble with Physics: the Rise of String Theory, the Fall of a Science, and What Comes Next are described. These solutions are obtained only from the properties of probability without any onto- logical hypotheses.

  16. Why Consumers Choose Managed Mutual Funds over Index Funds: Hypotheses from Consumer Behavior.

    Lichtenstein, Donald R.; Kaufmann, Patrick J.; Bhagat, Sanjai

    1999-01-01

    Using the literature of psychology, consumer behavior, and behavioral finance, a series of hypotheses is presented that account for consumer choices of managed over index mutual funds. Results indicate a need for consumer education to increase awareness of the benefits of index investing. (SK)

  17. Aggression among Children with ADHD, Anxiety, or Co-Occurring Symptoms: Competing Exacerbation and Attenuation Hypotheses

    Becker, Stephen P.; Luebbe, Aaron M.; Stoppelbein, Laura; Greening, Leilani; Fite, Paula J.

    2012-01-01

    Competing hypotheses for explaining the role of anxiety in the relation between attention-deficit/hyperactivity disorder (ADHD) symptoms and childhood aggression were evaluated. Two studies tested whether anxiety exacerbated, attenuated, or had no effect on the relation between ADHD and aggression subtypes among psychiatrically hospitalized…

  18. Coping with the Stigma of Mental Illness: Empirically-Grounded Hypotheses from Computer Simulations

    Kroska, Amy; Har, Sarah K.

    2011-01-01

    This research demonstrates how affect control theory and its computer program, "Interact", can be used to develop empirically-grounded hypotheses regarding the connection between cultural labels and behaviors. Our demonstration focuses on propositions in the modified labeling theory of mental illness. According to the MLT, negative societal…

  19. Bullying Victimization and Adolescent Self-Harm: Testing Hypotheses from General Strain Theory

    Hay, Carter; Meldrum, Ryan

    2010-01-01

    Self-harm is widely recognized as a significant adolescent social problem, and recent research has begun to explore its etiology. Drawing from Agnew's (1992) social psychological strain theory of deviance, this study considers this issue by testing three hypotheses about the effects of traditional and cyber bullying victimization on deliberate…

  20. Light on Trial: Using a Courtroom Drama to Compare Competing Scientific Hypotheses

    Smith, Frank A.

    2006-01-01

    A narrative in the form of a courtroom trial is used to compare evidence on the nature of light as part of an introductory college physics course. Prosecuting and defense attorneys present evidence for and against competing wave and particle hypotheses for light behavior while students play the roles of jurors. (Contains 5 figures.)

  1. Delinquency and peer acceptance in adolescence: a within-person test of Moffitt's hypotheses.

    Rulison, Kelly L; Kreager, Derek A; Osgood, D Wayne

    2014-11-01

    We tested 2 hypotheses derived from Moffitt's (1993) taxonomic theory of antisocial behavior, both of which are central to her explanation for the rise in delinquency during adolescence. We tested whether persistently delinquent individuals become more accepted by their peers during adolescence and whether individuals who abstain from delinquent behavior become less accepted. Participants were 4,359 adolescents from 14 communities in the PROSPER study, which assessed friendship networks and delinquency from 6th (M = 11.8 years) to 9th (M = 15.3 years) grade. We operationalized peer acceptance as number of nominations received (indegree centrality), attractiveness as a friend (adjusted indegree centrality), and network bridging potential (betweenness centrality) and tested the hypotheses with multilevel modeling. Contrary to Moffitt's hypothesis, persistently delinquent youths did not become more accepted between early and middle adolescence, and although abstainers were less accepted in early adolescence, they became more accepted over time. Results were similar for boys and girls; when differences occurred, they provided no support for Moffitt's hypotheses for boys and were opposite of her hypotheses for girls. Sensitivity analyses in which alternative strategies and additional data were used to identify persistently delinquent adolescents produced similar results. We explore the implications of these results for Moffitt's assertions that social mimicry of persistently antisocial adolescents leads to increases in delinquency and that social isolation leads to abstention. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:25243328

  2. Delinquency and Peer Acceptance in Adolescence: A Within-Person Test of Moffitt’s Hypotheses

    Rulison, Kelly L; Kreager, Derek A.; Osgood, D. Wayne

    2015-01-01

    We tested two hypotheses derived from Moffitt’s (1993) taxonomic theory of antisocial behavior, both of which are central to her explanation for the rise in delinquency during adolescence. Specifically, we tested whether persistently delinquent individuals become more accepted by their peers during adolescence and whether individuals who abstain from delinquent behavior become less accepted. Participants were 4,359 adolescents from 14 communities in the PROSPER study, which assessed friendship networks and delinquency from 6th (M = 11.8 years) to 9th (M = 15.3 years) grade. We operationalized peer acceptance as: number of nominations received (indegree centrality), attractiveness as a friend (adjusted indegree centrality), and network bridging potential (betweenness centrality) and tested the hypotheses using multilevel modeling. Contrary to Moffitt’s hypothesis, persistently delinquent youth did not become more accepted between early and middle adolescence, and although abstainers were less accepted in early adolescence, they became more accepted over time. Results were similar for boys and girls; when differences occurred, they provided no support for Moffitt’s hypotheses for boys and were opposite of her hypotheses for girls. Sensitivity analyses using alternative strategies and additional data to identify persistently delinquent adolescents produced similar results. We explore the implications of these results for Moffitt’s assertions that social mimicry of persistently antisocial adolescents leads to increases in delinquency and that social isolation leads to abstention. PMID:25243328

  3. Similarity and Difference in Multicultural Counseling: Considering the Attraction and Repulsion Hypotheses.

    Speight, Suzette L.; Vera, Elizabeth M.

    1997-01-01

    Summarizes issues relevant to empirical investigations of client and counselor preferences. Explores the effects of similarity and difference on relationship development and focuses on the attraction and repulsion hypotheses' applicability to multicultural counseling research and theory. It is hoped that differences between counseling and social…

  4. hKCNE4 inhibits the hKCNQ1 potassium current without affecting the activation kinetics

    Grunnet, Morten; Olesen, Søren-Peter; Klaerke, Dan A; Jespersen, Thomas

    2005-01-01

    All five members of the KCNE beta-subunit family are capable of modulating the KCNQ1 potassium current. We have previously published that the murine variant of KCNE4 inhibits the human KCNQ1 current [J. Physiol. 542 (2002) 119]. Recently, this finding has been challenged by Teng et al., stating...

  5. Centripetal versus centrifugal bias in visual line bisection: focusing attention on two hypotheses.

    McCourt, M E; Garlinghouse, M; Slater, J

    2000-01-01

    to the activation-orientation theory [M. Kinsbourne: Acta Psychologica 33, 193-201 (1970)]. When the range of line position exceeds the aperture of focal attention, we hypothesize that observers adopt a strategy in which attention is dynamically scanned in the direction of azimuthally displaced lines. The effects of attentional scanning on line bisection performance are quite robust. The centripetal scanning proposed to occur for widely displaced lines is consistent with the centripetal pattern of bisection error in this condition. PMID:10702377

  6. A brief report on the statistical study of net electric current in solar active regions with longitudinal fields of opposite polarity

    Yu Gao

    2013-01-01

    Dynamic processes occurring in solar active regions are dominated by the solar magnetic field.As of now,observations using a solar magnetograph have supplied us with the vector components of a solar photospheric magnetic field.The two transverse components of a photospheric magnetic field allow us to compute the amount of electric current.We found that the electric current in areas with positive (negative) polarity due to the longitudinal magnetic field have both positive and negative signs in an active region,however,the net current is found to be an order-ofmagnitude less than the mean absolute magnitude and has a preferred sign.In particular,we have statistically found that there is a systematic net electric current from areas with negative (positive) polarity to areas with positive (negative) polarity in solar active regions in the northern (southern) hemisphere,but during the solar minimum this tendency is reversed over time at some latitudes.The result indicates that there is weak net elecTRic current in areas of solar active regions with opposite polarity,thus providing further details about the hemispheric helicity rule found in a series of previous studies.

  7. The Seismic Broad Band Western Mediterranean (wm) Network and the Obs Fomar Pool: Current state and Obs activities.

    Pazos, Antonio; Davila, Jose Martin; Buforn, Elisa; Bezzeghoud, Mourad; Harnafi, Mimoun; Mattesini, Mauricio; Caldeira, Bento; Hanka, Winfried; El Moudnib, Lahcen; Strollo, Angelo; Roca, Antoni; Lopez de Mesa, Mireya; Dahm, Torsten; Cabieces, Roberto

    2016-04-01

    The Western Mediterranean (WM) seismic network started in 1996 as an initiative of the Royal Spanish Navy Observatory (ROA) and the Universidad Complutense de Madrid (UCM), with the collaboration of the GeoForschungsZentrum (GFZ) of Potsdam. A first broad band seismic station (SFUC) was installed close to Cádiz (South Spain). Since then, additional stations have been installed in the Ibero-Moghrebian region. In 2005, the "WM" code was assigned by the FDSN and new partners were jointed: Evora University (UEVO, Portugal), the Scientifique Institute of Rabat (ISRABAT, Morocco), and GFZ. Now days, the WM network is composed by 15 BB stations, all of them with Streckaisen STS-2 or STS-2.5 sensors, Quanterra or Earthdata digitizers and SeiscomP. Most them have co-installed a permanent geodetic GPS stations, and some them also have an accelerometer. There are 10 stations deployed in Spanish territory (5 in the Iberian peninsula, 1 in Balearic islands and 4 in North Africa Spanish places) with VSAT or Internet communications, 2 in Portugal (one of them without real time), and 3 in Morocco (2 VSAT and 1 ADSL). Additionally, 2 more stations (one in South Spain and one in Morocco) will be installed along this year. Additionally ROA has deployed a permanent real time VBB (CMG-3T: 360s) station at the Alboran Island. Due to the fact that part of the seismic activity is located at marine areas, and also because of the poor geographic azimuthal coverage at some zones provided by the land stations (specially in the SW of the San Vicente Cape area), ROA and UCM have acquired six broad band "LOBSTERN" OBS, manufactured by KUM (Kiel, Germany), conforming the OBS FOMAR pool. Three of them with CMG-40T sensor and the other with Trillium 120. These OBS were deployed along the Gibraltar strait since January to November 2014 to study the microseismicity in the Gibraltar strait area. In September 2015 FOMAR network has been deployed in SW of the San Vicente Cape for 8 months as a part of

  8. Search for active neutrino disappearance using neutral-current interactions in the MINOS long-baseline experiment

    We have measured the rates and spectra of neutral-current neutrino interactions in the MINOS detectors, which are separated by 734 km. A depletion in the rate at the far site would indicate mixing between νμ and a sterile particle. The depletion of the total neutral-current event rate at the far site is limited to be below 17% at 90% confidence level without νe appearance. Assuming oscillations occur at a single mass-squared splitting, a fit to the neutral- and charged-current energy spectra shows the fraction of νμ oscillating to a sterile neutrino is 0.28-0.28+0.25(stat.+syst.). Including νe appearance at the current experimental upper bound limits the depletion to be below 21% at 90% confidence level and the fit fraction of νμ oscillating to a sterile neutrino is 0.43-0.27+0.23(stat.+syst.)

  9. MMS Spacecraft Observation of Near Tail Thin Current Sheets: Their Locations, Conditions for Formation and Relation to Geomagnetic Activity

    Zhao, C.; Russell, C. T.; Strangeway, R. J.; Anderson, B. J.; Baumjohann, W.; Bromund, K. R.; Chutter, M.; Fischer, D.; Kepko, L.; Le Contel, O.; Leinweber, H. K.; Magnes, W.; Nakamura, R.; Plaschke, F.; Slavin, J. A.; Torbert, R. B.

    2015-12-01

    During the commissioning phase of the MMS mission, when the apogee (~12Re) of MMS orbit swept from the pre-midnight to the dusk section of the magnetosphere, the four spacecraft probed the dynamic region of the near-Earth magnetotail. The MMS fleet encountered many structures with unambiguously small-scale spatial gradient in magnetic field (comparable to the separation of the fleet), indicating the existence of very thin current sheets in this near-tail region. During this commissioning phase, the MMS spacecraft were in a string of pearls configuration, not ideally suitable for "curlometer" determination of the current density. Thus the current density and thickness of the sheets are only roughly determined using reasonable assumptions. In this study we correlate the current sheet's location and thickness with solar wind conditions and the ground magnetic field records.

  10. Conditional knockout of TMEM16A/anoctamin1 abolishes the calcium-activated chloride current in mouse vomeronasal sensory neurons

    Amjad, Asma; Hernandez-Clavijo, Andres; Pifferi, Simone; Maurya, Devendra Kumar; Boccaccio, Anna; Franzot, Jessica; Rock, Jason; Menini, Anna

    2015-01-01

    Pheromones are substances released from animals that, when detected by the vomeronasal organ of other individuals of the same species, affect their physiology and behavior. Pheromone binding to receptors on microvilli on the dendritic knobs of vomeronasal sensory neurons activates a second messenger cascade to produce an increase in intracellular Ca2+ concentration. Here, we used whole-cell and inside-out patch-clamp analysis to provide a functional characterization of currents activated by C...

  11. Prioritization of anti-malarial hits from nature: chemo-informatic profiling of natural products with in vitro antiplasmodial activities and currently registered anti-malarial drugs

    Egieyeh, Samuel Ayodele; Syce, James; Malan, Sarel F.; Christoffels, Alan

    2016-01-01

    Background A large number of natural products have shown in vitro antiplasmodial activities. Early identification and prioritization of these natural products with potential for novel mechanism of action, desirable pharmacokinetics and likelihood for development into drugs is advantageous. Chemo-informatic profiling of these natural products were conducted and compared to currently registered anti-malarial drugs (CRAD). Methods Natural products with in vitro antiplasmodial activities (NAA) we...

  12. Historical hypotheses of chimpanzee tool use behaviour in relation to natural and human-induced changes in an East African rain forest1

    Gruber, Thibaud

    2014-01-01

    Chimpanzees and humans have co-existed in Africa for millennia. The forests inhabited by chimpanzees have experienced numerous changes in recent time, most notably during the last 12,000 years, as the current interglacial age started. In this article, I will study the case of Western Ugandan forests to describe the different factors, natural and human-induced, which affect a tropical forest, and draw hypotheses on the influence of these changes on chimpanzee cultural behaviour. Before colonia...

  13. A modular modelling framework for hypotheses testing in the simulation of urbanisation

    Cottineau, Clementine; Chapron, Paul; Coyrehourcq, Sebastien Rey; Pumain, Denise

    2015-01-01

    In this paper, we present a modelling experiment developed to study systems of cities and processes of urbanisation in large territories over long time spans. Building on geographical theories of urban evolution, we rely on agent-based models to 1/ formalise complementary and alternative hypotheses of urbanisation and 2/ explore their ability to simulate observed patterns in a virtual laboratory. The paper is therefore divided into two sections : an overview of the mechanisms implemented to represent competing hypotheses used to simulate urban evolution; and an evaluation of the resulting model structures in their ability to simulate - efficiently and parsimoniously - a system of cities (the Former Soviet Union) over several periods of time (before and after the crash of the USSR). We do so using a modular framework of model-building and evolutionary algorithms for the calibration of several model structures. This project aims at tackling equifinality in systems dynamics by confronting different mechanisms wi...

  14. NegaWatt 2011-2050 scenario - Hypotheses and method. Technical report, May 2014

    This report proposes an analysis of the negaWatt 2011 scenario. It describes in detail the methodology adopted to elaborate this prospective scenario, and presents the major part of the hypotheses which structure this scenario. A first part presents the approach and methodology (constraints, scenario, model). The second part addresses the issue of energy saving and energy efficiency through a sector-based analysis (housing and office building, transports, industrial and agricultural production). The third part studies the substitution by renewable energies through a supply analysis: energy production based on biomass, renewable energies, and fissile and fossil energies. It outlines the major role of grids in the supply-demand balance. The results of the negaWatt 2011 scenario are presented in terms of final energy, primary energies, and impact on greenhouse gas emissions. Hypotheses and results related to the different sectors (building, transports, industry and agriculture, energy production) are given in appendix

  15. The scientific role of hypotheses and the reasoning of college students in physics problem solving

    Jenaro Guisasola; Mikel Ceberio; José Luis Zubimendi

    2003-01-01

    This paper attempts to explore how freshmen college students in engineering state hypoteses to build their own problem solving structure when dealing with physics problems. From the constructivist perspective of the teaching and learning process hypotheses stating plays a fundamental role to check the coherence of students' ideas against the theoretical framework. The main instruments to accede to students' reasoning were their written solutions to four problematic situations in which they we...

  16. Self-Selection and Learning-by-Exporting Hypotheses: Micro Level Evidence

    Rehman, Naqeeb Ur

    2016-01-01

    This aim of this empirical paper is to investigate the self-selection and learning-by-exporting hypotheses. This study addresses the reverse causality between innovation, productivity and exporting using micro level data on 29 countries from Eurasia and Central and Eastern Europe (CEE). CDM estimation results suggest that innovation and productivity positively influence the firm’s exporting and vice versa. This study has supported the self-selection and learning-by-exporting hy...

  17. Multi-Hypotheses Tracking using the Dempster-Shafer Theory. Application to ambiguous road context.

    Gruyer, Dominique; DEMMEL, Sébastien; MAGNIER, Valentin; Belaroussi, Rachid

    2016-01-01

    This paper presents a Multi-Hypotheses Tracking (MHT) approach that allows solving ambiguities that arise with previous methods of associating targets and tracks within a highly volatile vehicular environment. The previous approach based on the Dempster-Shafer Theory assumes that associations between tracks and targets are unique; this was shown to allow the formation of ghost tracks when there was too much ambiguity or conflict for the system to take a meaningful decision. The MHT a...

  18. Why Announce Leadership Contributions? An Experimental Study of the Signaling and Reciprocity Hypotheses

    Potters, J.J.M.; Sefton, M.; Vesterlund, L.

    2001-01-01

    Why do fundraisers announce initial contributions to their charity?Potential explanations are that these announcements cause future donors to increase their contributions, either because they want to reciprocate the generosity of earlier donors, or because the initial contributions are seen as a signal of the charity's quality.Using experimental methods we investigate these two hypotheses.When only the first donor is informed of the public good's quality, subjects not only copy the initial co...

  19. Delayed Ettringite Formation:Suggestion of a Global Mechanism in Order to Link Previous Hypotheses

    BRUNETAUD, X; DIVET, L; Damidot, D.

    2004-01-01

    Ettringite observed in macroscopic paste cracks during DEF is often held responsible for concrete deterioration. However, some authors have raised the hypothesis of an homogeneous paste expansion resulting from ettringite crystallisation in the C-S-H porosity, which does not attribute any mechanical effects to the subsequent formation of ettringite crystals in the voids. Thus the role of ettringite is still controversial.In this paper, we are tempting to link the two previous hypotheses in a ...

  20. Molecular Data are Transforming Hypotheses on the Origin and Diversification of Eukaryotes

    Tekle, Yonas I.; Parfrey, Laura Wegener; Katz, Laura A

    2009-01-01

    The explosion of molecular data has transformed hypotheses on both the origin of eukaryotes and the structure of the eukaryotic tree of life. Early ideas about the evolution of eukaryotes arose through analyses of morphology by light microscopy and later electron microscopy. Though such studies have proven powerful at resolving more recent events, theories on origins and diversification of eukaryotic life have been substantially revised in light of analyses of molecular data including gene an...

  1. Experimental basis of the hypotheses on the mechanism of skeletal muscle contraction

    Grazi, Enrico

    2012-01-01

    With time clever hypotheses may be accepted as “facts” without being supported by solid experimental evidence. In our opinion this happened with muscle contraction where pure suggestions still occupy the scene and delay the progress of the research. Among these suggestions are: 1. the believe that viscosity is irrelevant in the economy of muscle contraction, 2. the concept of the drag stroke, 3. some interpretations of the significance of the Huxley-Simmons manoeuvre, 4. the definition of the...

  2. Basing the treatment of stereotypic and self-injurious behaviors on hypotheses of their causes.

    Repp, A C; Felce, D; Barton, L E

    1988-01-01

    Stereotypic and self-injurious behaviors are common forms of maladaptive responding demonstrated by severely handicapped persons. Various review papers suggest that no single treatment procedure is universally effective. Although there may be many reasons for this finding, one could be that people engage in these behaviors for various reasons, and that procedures that are incompatible with the cause of the behavior are unlikely to be effective. These studies also suggest many hypotheses for t...

  3. Managerial diseconomies of scale: Literature survey and hypotheses anchored in transaction cost economics

    Staffan Canback

    1998-01-01

    This working paper tests Oliver Williamson’s proposition that transaction cost economics can explain the limits of firm size. A review of the relevant literature corroborates Williamson’s theoretical framework and five hypotheses are formulated: (1) Bureaucratic failure, in the form of atmospheric consequences, bureaucratic insularity, incentive limits and communication distortion, increases with firm size; (2) Large firms exhibit economies of scale; (3) Diseconomies of scale from bureaucrati...

  4. Testing Behavioral Hypotheses Using an Integrated Model of Grocery Store Shopping Path and Purchase Behavior

    Hui, Sam K.; Bradlow, Eric T; Peter S. Fader

    2009-01-01

    We examine three sets of established behavioral hypotheses about consumers' in-store behavior using field data on grocery store shopping paths and purchases. Our results provide field evidence for the following empirical regularities. First, as consumers spend more time in the store, they become more purposeful--they are less likely to spend time on exploration and more likely to shop/buy. Second, consistent with "licensing" behavior, after purchasing virtue categories, consumers are more lik...

  5. h(odor): Interactive Discovery of Hypotheses on the Structure-Odor Relationship in Neuroscience

    Bosc, Guillaume; Plantevit, Marc; Boulicaut, Jean-François; Bensafi, Moustafa; Kaytoue, Mehdi

    2016-01-01

    International audience From a molecule to the brain perception, olfaction is a complex phenomenon that remains to be fully understood in neuroscience. Latest studies reveal that the physico-chemical properties of volatile molecules can partly explain the odor perception. Neuroscientists are then looking for new hypotheses to guide their research: physico-chemical descriptors distinguishing a subset of perceived odors. To answer this problem, we present the platform h(odor) that implements ...

  6. Delinquency and Peer Acceptance in Adolescence: A Within-Person Test of Moffitt’s Hypotheses

    Rulison, Kelly L.; Kreager, Derek A.; Osgood, D. Wayne

    2014-01-01

    We tested two hypotheses derived from Moffitt’s (1993) taxonomic theory of antisocial behavior, both of which are central to her explanation for the rise in delinquency during adolescence. Specifically, we tested whether persistently delinquent individuals become more accepted by their peers during adolescence and whether individuals who abstain from delinquent behavior become less accepted. Participants were 4,359 adolescents from 14 communities in the PROSPER study, which assessed friendshi...

  7. Testing fine sediment connectivity hypotheses using fallout radionuclide tracers in a small catchment with badlands. Vallcebre Research Catchments (NE Spain)

    Gallart, Francesc; Latron, Jérôme; Vuolo, Diego; Martínez-Carreras, Núria; Pérez-Gallego, Nuria; Ferrer, Laura; Estrany, Joan

    2016-04-01

    In the Vallcebre Research Catchments (NE Spain), results obtained during over 20 years showed that badlands are the primary sources of sediments to the drainage network. Parent lutitic rocks are weathered during winter producing regoliths, which are eroded from badland surfaces mainly during summer intense rainstorms. Even if the produced sediments are mainly fine, due to the ephemeral nature of summer runoff events most of them are deposited on the stream beds, where they may remain during some time (months to years). Within the MEDhyCON project, a fallout radionuclides (FRNs) tracing experiment (i.e., excess lead 210 (Pbx-210) and beryllium 7 (Be-7)) is being carried out in order to investigate sediment connectivity. A simplified Pbx-210 balance model on badland surfaces suggested a seasonal sawtooth-like activity pattern: FRN being accumulated in regoliths from October to June and depleted in summer. Early summer erosion events would produce the sediments with the highest activity whereas late summer events would produce sediments with the lowest activity coming from the deeper regolith horizons. These findings lead us to launch two sediment transfer connectivity hypotheses analysing respectively the temporal and spatial variability of the Pb-210 activities within the fine sediments at the small catchment scale: (1) The temporal variability of suspended sediment activities at the gauging stations is a measure of sediment transfer immediacy, ergo connectivity. Hence, a high variability in suspended sediment activities, mimicking regolith activity temporal pattern would indicate high connectivity, whereas a low variability, meaning that sediments are mostly pooled in a large and slowly moving stock, would indicate low connectivity. (2) In a drainage system where fine sediments temporarily remain on the dry stream bed, the ratio between fine sediment activities at the sources and fine in-stream sediment activities downstream is a measure of sediment connectivity

  8. Risk, innovation, electricity infrastructure and construction cost overruns: Testing six hypotheses

    This study investigates the frequency and magnitude of cost and time overruns occurring during the construction of 401 electricity projects built between 1936 and 2014 in 57 countries. In aggregate, these projects required approximately $820 billion in investment, and amounted to 325,515 MW of installed capacity and 8495 km of transmission lines. We use this sample of projects to test six hypotheses about construction cost overruns related to (1) diseconomies of scale, (2) project delays, (3) technological learning, (4) regulation and markets, (5) decentralization and modularity, and (6) normalization of results to scale. We find that nuclear reactors are the riskiest technology in terms of mean cost escalation as a percentage of budget and frequency; that hydroelectric dams stand apart for their mean cost escalation in total dollars; that many of the hypotheses grounded in the literature appear wrong; and that financing, partnerships, modularity, and accountability may have more to do with overruns than technology. - Highlights: • Many hypotheses about construction overruns grounded in the literature appear wrong. • Nuclear reactors are the most prone to cost overruns as a percentage of budget and frequency. • Hydroelectric dams stand apart for their mean cost escalation in total dollars. • Solar and wind energy systems are least at risk to cost overruns

  9. Using computational fluid dynamics to test functional and ecological hypotheses in fossil taxa

    Rahman, Imran

    2016-04-01

    Reconstructing how ancient organisms moved and fed is a major focus of study in palaeontology. Traditionally, this has been hampered by a lack of objective data on the functional morphology of extinct species, especially those without a clear modern analogue. However, cutting-edge techniques for characterizing specimens digitally and in three dimensions, coupled with state-of-the-art computer models, now provide a robust framework for testing functional and ecological hypotheses even in problematic fossil taxa. One such approach is computational fluid dynamics (CFD), a method for simulating fluid flows around objects that has primarily been applied to complex engineering-design problems. Here, I will present three case studies of CFD applied to fossil taxa, spanning a range of specimen sizes, taxonomic groups and geological ages. First, I will show how CFD enabled a rigorous test of hypothesized feeding modes in an enigmatic Ediacaran organism with three-fold symmetry, revealing previously unappreciated complexity of pre-Cambrian ecosystems. Second, I will show how CFD was used to evaluate hydrodynamic performance and feeding in Cambrian stem-group echinoderms, shedding light on the probable feeding strategy of the latest common ancestor of all deuterostomes. Third, I will show how CFD allowed us to explore the link between form and function in Mesozoic ichthyosaurs. These case studies serve to demonstrate the enormous potential of CFD for addressing long-standing hypotheses for a variety of fossil taxa, opening up an exciting new avenue in palaeontological studies of functional morphology.

  10. Beyond current guidelines: reduction in minimum administered radiopharmaceutical activity with preserved diagnostic image quality in pediatric hepatobiliary scintigraphy

    Fahey, Frederic; Markelewicz, Robert; Grant, Frederick; Drubach, Laura; Treves, S. Ted [Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging, Boston Children' s Hospital, Boston, MA (United States); Harvard Medical School, Joint Program in Nuclear Medicine, Boston (United States); Zukotynski, Katherine [University of Toronto, Department of Medical Imaging, Sunnybrook Health Sciences Centre, Toronto (Canada); Harvard Medical School, Joint Program in Nuclear Medicine, Boston (United States); Zurakowski, David [Boston Children' s Hospital, Departments of Anesthesia and Surgery, Boston (United States); Falone, Anthony; Vitello, Marie; Cao, Xinhua [Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging, Boston Children' s Hospital, Boston, MA (United States); Vija, A.H.; Bhattacharya, Manojeet; Ding, Xinhong [Siemens Medical Solutions USA, Inc., Molecular Imaging, Malvern, PA (United States); Bar-Sever, Zvi [Schneider Children' s Medical Center, Petach Tikvah (Israel); Tel-Aviv University, Tel-Aviv (Israel); Gelfand, Michael [Cincinnati Children' s Hospital, Cincinnati, OH (United States)

    2014-12-15

    To determine if the minimum administered radiopharmaceutical activity for hepatobiliary scintigraphy can be reduced while preserving diagnostic image quality using enhanced planar processing (EPP). A total of 40 infants between 10 and 270 days old (body mass 2.2 - 6.5 kg) had hepatobiliary scintigraphy during the period 2004 - 2010 following the intravenous administration of either {sup 99m}Tc-mebrofenin (18 patients) or {sup 99m}Tc-disofenin (22 patients). Due to the small size of these patients, they all received the minimum administered activity of 18.5 MBq consistent with the North American Consensus Guidelines. Six nuclear medicine physicians subjectively graded the acceptability of the image quality for clinical interpretation using a four-point scale (not acceptable, fair, good, excellent). Each physician independently graded seven image sets including the original study (full activity) and simulated reduced activity studies using binomial subsampling (50 % of full activity, 25 % of full activity and activity reduced by weight), with and without EPP. For full-activity studies, 98 % were deemed acceptable by the six physicians for clinical interpretation. The percentages of acceptable 50 % reduced activity studies with and without EPP were not significantly different from the percentage of acceptable full-activity studies (P = 0.193 and P = 0.998, respectively). The percentage of acceptable 25 % reduced activity studies without EPP was significantly different from the percentage of acceptable full-activity studies (P < 0.001); however, this difference vanished when EPP was applied (P = 0.482). The activity reduced by weight ranged from 1.85 to 4.81 MBq (10 % to 26 % of full dose) and the percentages of acceptable studies with and without EPP were significantly different from the percentage of acceptable full-activity studies (P < 0.001 and P = 0.02, respectively). Clinically interpretable hepatobiliary scintigraphy images can be obtained in infants when the

  11. Beyond current guidelines: reduction in minimum administered radiopharmaceutical activity with preserved diagnostic image quality in pediatric hepatobiliary scintigraphy

    To determine if the minimum administered radiopharmaceutical activity for hepatobiliary scintigraphy can be reduced while preserving diagnostic image quality using enhanced planar processing (EPP). A total of 40 infants between 10 and 270 days old (body mass 2.2 - 6.5 kg) had hepatobiliary scintigraphy during the period 2004 - 2010 following the intravenous administration of either 99mTc-mebrofenin (18 patients) or 99mTc-disofenin (22 patients). Due to the small size of these patients, they all received the minimum administered activity of 18.5 MBq consistent with the North American Consensus Guidelines. Six nuclear medicine physicians subjectively graded the acceptability of the image quality for clinical interpretation using a four-point scale (not acceptable, fair, good, excellent). Each physician independently graded seven image sets including the original study (full activity) and simulated reduced activity studies using binomial subsampling (50 % of full activity, 25 % of full activity and activity reduced by weight), with and without EPP. For full-activity studies, 98 % were deemed acceptable by the six physicians for clinical interpretation. The percentages of acceptable 50 % reduced activity studies with and without EPP were not significantly different from the percentage of acceptable full-activity studies (P = 0.193 and P = 0.998, respectively). The percentage of acceptable 25 % reduced activity studies without EPP was significantly different from the percentage of acceptable full-activity studies (P < 0.001); however, this difference vanished when EPP was applied (P = 0.482). The activity reduced by weight ranged from 1.85 to 4.81 MBq (10 % to 26 % of full dose) and the percentages of acceptable studies with and without EPP were significantly different from the percentage of acceptable full-activity studies (P < 0.001 and P = 0.02, respectively). Clinically interpretable hepatobiliary scintigraphy images can be obtained in infants when the minimum

  12. Study of the MHD activity of a tokamak plasma in the lower hybrid frequency wave current generating regime

    Confinement by noninductive currents was investigated in experiments on MHD instability in a tokamak plasma. The change of dependence of plasma current density and resistivity as a function of electron temperature (parameters which govern the evolution of MHD instability) is stressed. Experiments on the PETULA-B tokamak allowed the determination of the nature of the instabilities (characterization of the numbers m and n for resistance tearing modes; characterization of sawtooth instabilities). Instabilities are analyzed as a function of discharges in plasma current generation by hybrid waves. On PETULA-B, the stabilisation takes two forms: stabilization of sawtooths in correlation with mode excitation (m=2, n=1); and stabilization of sawtooths by mode saturation (m=1, n=1)

  13. Activity-dependent increases in local oxygen consumption correlate with postsynaptic currents in the mouse cerebellum in vivo

    Mathiesen, Claus; Caesar, Kirsten; Thomsen, Kirsten Engelund;

    2011-01-01

    Evoked neural activity correlates strongly with rises in cerebral metabolic rate of oxygen (CMRO(2)) and cerebral blood flow (CBF). Activity-dependent rises in CMRO(2) fluctuate with ATP turnover due to ion pumping. In vitro studies suggest that increases in cytosolic Ca(2+) stimulate oxidative...

  14. Activity-dependent increases in local oxygen consumption correlate with post-synaptic currents in the mouse cerebellum in vivo

    Mathiesen, Claus; Caesar, Kirsten; Thomsen, Kirsten Joan;

    2011-01-01

    Evoked neural activity correlates strongly with rises in cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow. Activity-dependent rises in CMRO2 fluctuate with ATP turnover due to ion pumping. In vitro studies suggest that increases in cytosolic Ca2+ stimulate oxidative metabolism via...

  15. A Comparison of Professional-Level Faculty and Student Perceptions of Active Learning: Its Current Use, Effectiveness, and Barriers

    Miller, Cynthia J.; Metz, Michael J.

    2014-01-01

    Active learning is an instructional method in which students become engaged participants in the classroom through the use of in-class written exercises, games, problem sets, audience-response systems, debates, class discussions, etc. Despite evidence supporting the effectiveness of active learning strategies, minimal adoption of the technique has…

  16. Transitionality in addiction: A "temporal continuum" hypotheses involving the aberrant motivation, the hedonic dysregulation, and the aberrant learning.

    Patrono, Enrico; Gasbarri, Antonella; Tomaz, Carlos; Nishijo, Hisao

    2016-08-01

    Addiction is a chronic compulsion and relapsing disorder. It involves several brain areas and circuits, which encode vary functions such as reward, motivation, and memory. Drug addiction is defined as a "pathological pattern of use of a substance", characterized by the loss of control on drug-taking-related behaviors, the pursuance of those behaviors even in the presence of negative consequences, and a strong motivated activity to assume substances. Three different theories guide experimental research on drug addiction. Each of these theories consider singles features, such as an aberrant motivation, a hedonic dysregulation, and an aberrant habit learning as the main actor to explain the entire process of the addictive behaviors. The major goal of this study is to present a new hypotheses of transitionality from a controlled use to abuse of addictive substances trough the overview of the three different theories, considering all the single features of each single theory together on the same "temporal continuum" from use to abuse of addictive substances. Recently, it has been suggested that common neural systems may be activated by natural and pharmacological stimuli, raising the hypotheses that binge-eating disorders could be considered as addictive behaviors. The second goal of this study is to present evidences in order to highlight a possible psycho-bio-physiological superimposition between drug and "food addiction". Finally, interesting questions are brought up starting from last findings about a theoretical/psycho-bio-physiological superimposition between drug and "food addiction" and their possibly same transitionality along the same "temporal continuum" from use to abuse of addictive substances in order to investigate new therapeutic strategies based on new therapeutic strategies based on the individual moments characterizing the transition from the voluntary intake of substances to the maladaptive addictive behavior. PMID:27372858

  17. High extracellular Ca2+ stimulates Ca2+-activated Cl- currents in frog parathyroid cells through the mediation of arachidonic acid cascade.

    Yukio Okada

    Full Text Available Elevation of extracellular Ca(2+ concentration induces intracellular Ca(2+ signaling in parathyroid cells. The response is due to stimulation of the phospholipase C/Ca(2+ pathways, but the direct mechanism responsible for the rise of intracellular Ca(2+ concentration has remained elusive. Here, we describe the electrophysiological property associated with intracellular Ca(2+ signaling in frog parathyroid cells and show that Ca(2+-activated Cl(- channels are activated by intracellular Ca(2+ increase through an inositol 1,4,5-trisphophate (IP(3-independent pathway. High extracellular Ca(2+ induced an outwardly-rectifying conductance in a dose-dependent manner (EC(50 ∼6 mM. The conductance was composed of an instantaneous time-independent component and a slowly activating time-dependent component and displayed a deactivating inward tail current. Extracellular Ca(2+-induced and Ca(2+ dialysis-induced currents reversed at the equilibrium potential of Cl(- and were inhibited by niflumic acid (a specific blocker of Ca(2+-activated Cl(- channel. Gramicidin-perforated whole-cell recording displayed the shift of the reversal potential in extracellular Ca(2+-induced current, suggesting the change of intracellular Cl(- concentration in a few minutes. Extracellular Ca(2+-induced currents displayed a moderate dependency on guanosine triphosphate (GTP. All blockers for phospholipase C, diacylglycerol (DAG lipase, monoacylglycerol (MAG lipase and lipoxygenase inhibited extracellular Ca(2+-induced current. IP(3 dialysis failed to induce conductance increase, but 2-arachidonoylglycerol (2-AG, arachidonic acid and 12S-hydroperoxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12(S-HPETE dialysis increased the conductance identical to extracellular Ca(2+-induced conductance. These results indicate that high extracellular Ca(2+ raises intracellular Ca(2+ concentration through the DAG lipase/lipoxygenase pathway, resulting in the activation of Cl(- conductance.

  18. Current density and catalyst-coated membrane resistance distribution of hydro-formed metallic bipolar plate fuel cell short stack with 250 cm2 active area

    Haase, S.; Moser, M.; Hirschfeld, J. A.; Jozwiak, K.

    2016-01-01

    An automotive fuel cell with an active area of 250 cm2 is investigated in a 4-cell short stack with a current and temperature distribution device next to the bipolar plate with 560 current and 140 temperature segments. The electrical conductivities of the bipolar plate and gas diffusion layer assembly are determined ex-situ with this current scan shunt module. The applied fuel cell consists of bipolar plates constructed of 75-μm-thick, welded stainless-steel foils and a graphitic coating. The electrical conductivities of the bipolar plate and gas diffusion layer assembly are determined ex-situ with this module with a 6% deviation in in-plane conductivity. The current density distribution is evaluated up to 2.4 A cm-2. The entire cell's investigated volumetric power density is 4.7 kW l-1, and its gravimetric power density is 4.3 kW kg-1 at an average cell voltage of 0.5 V. The current density distribution is determined without influencing the operating cell. In addition, the current density distribution in the catalyst-coated membrane and its effective resistivity distribution with a finite volume discretisation of Ohm's law are evaluated. The deviation between the current density distributions in the catalyst-coated membrane and the bipolar plate is determined.

  19. Why Be a Shrub? A Basic Model and Hypotheses for the Adaptive Values of a Common Growth Form.

    Götmark, Frank; Götmark, Elin; Jensen, Anna M

    2016-01-01

    Shrubs are multi-stemmed short woody plants, more widespread than trees, important in many ecosystems, neglected in ecology compared to herbs and trees, but currently in focus due to their global expansion. We present a novel model based on scaling relationships and four hypotheses to explain the adaptive significance of shrubs, including a review of the literature with a test of one hypothesis. Our model describes advantages for a small shrub compared to a small tree with the same above-ground woody volume, based on larger cross-sectional stem area, larger area of photosynthetic tissue in bark and stem, larger vascular cambium area, larger epidermis (bark) area, and larger area for sprouting, and faster production of twigs and canopy. These components form our Hypothesis 1 that predicts higher growth rate for a small shrub than a small tree. This prediction was supported by available relevant empirical studies (14 publications). Further, a shrub will produce seeds faster than a tree (Hypothesis 2), multiple stems in shrubs insure future survival and growth if one or more stems die (Hypothesis 3), and three structural traits of short shrub stems improve survival compared to tall tree stems (Hypothesis 4)-all hypotheses have some empirical support. Multi-stemmed trees may be distinguished from shrubs by more upright stems, reducing bending moment. Improved understanding of shrubs can clarify their recent expansion on savannas, grasslands, and alpine heaths. More experiments and other empirical studies, followed by more elaborate models, are needed to understand why the shrub growth form is successful in many habitats. PMID:27507981

  20. Why Be a Shrub? A Basic Model and Hypotheses for the Adaptive Values of a Common Growth Form

    Götmark, Frank; Götmark, Elin; Jensen, Anna M.

    2016-01-01

    Shrubs are multi-stemmed short woody plants, more widespread than trees, important in many ecosystems, neglected in ecology compared to herbs and trees, but currently in focus due to their global expansion. We present a novel model based on scaling relationships and four hypotheses to explain the adaptive significance of shrubs, including a review of the literature with a test of one hypothesis. Our model describes advantages for a small shrub compared to a small tree with the same above-ground woody volume, based on larger cross-sectional stem area, larger area of photosynthetic tissue in bark and stem, larger vascular cambium area, larger epidermis (bark) area, and larger area for sprouting, and faster production of twigs and canopy. These components form our Hypothesis 1 that predicts higher growth rate for a small shrub than a small tree. This prediction was supported by available relevant empirical studies (14 publications). Further, a shrub will produce seeds faster than a tree (Hypothesis 2), multiple stems in shrubs insure future survival and growth if one or more stems die (Hypothesis 3), and three structural traits of short shrub stems improve survival compared to tall tree stems (Hypothesis 4)—all hypotheses have some empirical support. Multi-stemmed trees may be distinguished from shrubs by more upright stems, reducing bending moment. Improved understanding of shrubs can clarify their recent expansion on savannas, grasslands, and alpine heaths. More experiments and other empirical studies, followed by more elaborate models, are needed to understand why the shrub growth form is successful in many habitats. PMID:27507981