WorldWideScience

Sample records for bottom current activity

  1. Glaciomarine sedimentation and bottom current activity on the north-western and northern continental margins of Svalbard during the late Quaternary

    Science.gov (United States)

    Chauhan, Teena; Noormets, Riko; Rasmussen, Tine L.

    2016-04-01

    Palaeo-bottom current strength of the West Spitsbergen Current (WSC) and the influence of the Svalbard-Barents Sea Ice Sheet (SBIS) on the depositional environment along the northern Svalbard margins are poorly known. Two gravity cores from the southern Yermak Plateau and the upper slope north of Nordaustlandet, covering marine isotope stage (MIS) 1 to MIS 5, are investigated. Five lithofacies, based on grain size distribution, silt/clay ratio, content and mean of sortable silt (SS), are distinguished to characterise the contourite-dominated sedimentary environments. In addition, depositional environments are described using total organic carbon (TOC), total sulphur (TS) and calcium carbonate (CaCO3) contents of sediments. Facies A, containing coarse SS, suggests strong bottom current activity and good bottom water ventilation conditions as inferred from low TOC content. This facies was deposited during the glacial periods MIS 4, MIS 2 and during the late Holocene. Facies B is dominated by fine SS indicating weak bottom current and poor ventilation (cf. high TOC content of 1.2-1.6%), and correlates with the MIS 4/3 and MIS 2/1 transition periods. With an equal amount of clay and sand, fine SS and high content of TOC, facies C indicates reduced bottom current strength for intervals with sediment supply from proximal sources such as icebergs, sea ice or meltwater discharge. This facies was deposited during the last glacial maximum. Facies D represents mass-flow deposits on the northern Svalbard margin attributed to the SBIS advance at or near the shelf edge. Facies E sediments indicating moderate bottom current strength were deposited during MIS 5 and MIS 3, and during parts of MIS 2. This first late Quaternary proxy record of the WSC flow and sedimentation history from the northern Svalbard margin suggests that the oceanographic conditions and ice sheet processes have exerted first-order control on sediment properties.

  2. Morphology and distribution of Oligocene and Miocene pockmarks in the Danish North Sea -implications for bottom current activity and fluid migration

    DEFF Research Database (Denmark)

    Andresen, Katrine Juul; Huuse, Mads; Clausen, O.R.

    2008-01-01

    This study gives the first description of 33 mid-Oligocene and 646 late Miocene pockmarks mapped in the Danish part of the central North Sea. The pockmarks are all highly elongated, with average long- and short axes of 2.5 km and 700 m, and average internal depth of 30 m. The Miocene pockmarks...... development, only influenced by fluid expulsion and subsequent erosion by bottom currents. Group B pockmarks are influenced by bottom current erosion, current and gas winnowing and possibly authigenic carbonate precipitation. Group C pockmarks represent a further development from Group B pockmarks...... with further winnowing, carbonate precipitation and removal of seafloor sediment to form the ring-shape. Current erosion has exerted the major influence on the final geometry of 83% of the pockmarks. The pockmarks occur above gas-mature Jurassic source rocks, modelled to be in the generative window during...

  3. Spectral characteristics of mesoscale variability of the bottom currents in the Ocean

    Science.gov (United States)

    Morozov, E. G.; Neiman, V. G.

    2016-11-01

    We performed spectral analysis of variations in the bottom currents on the basis of direct measurements in a number of regions of the entire Atlantic Ocean. We compared the spectra of the atmospheric pressure fluctuations at sea level and fluctuations of current velocities in the bottom layer. A significant energy of current fluctuations near the bottom with a synoptic period in the range 10-15 days that exceeds similar energies in the other regions of the ocean was found in the region of the Newfoundland energetically active zone, where increased cyclonic activity in the atmosphere is observed.

  4. Deep water bottom current deposition in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    There are some active bottom currents on the northern continental slope of the South China Sea (SCS). Reflection seismic profiles show that the bottom current channels occur in the water depth range of 1000 to 2700 m,extending from the NE to the SW,leading to accumulation of discontinuous drifts with higher sedimentation rates on the eastern side of the channel. The stacking pattern of the layers sug-gests that these drifts propagated southwestward,following the direction of the bottom currents. One sedimentary drift to the southeast of the Dongsha Islands has the highest sedimentation rate of 97cm/ka in the last 12 ka. The sedimentary characteristics of the sediment layers indicate that these bottom currents are most likley caused by the water movement of a branch of the West Pacific Ocean Current,which enters the northern SCS via the Bashi Strait. Once formed,the bottom currents trans-port sediments along the northern slope of SCS southwestward and finally disappear into the central basin of the SCS. Due to the bottom current activity,the deep-sea sedimentary process in the northern SCS is complex.

  5. EFFECTS OF WAVE-CURRENT INTERACTIONS ON BOTTOM STRESS AND CURRENTS

    Institute of Scientific and Technical Information of China (English)

    Yin Bao-shu; Yang De-zhou; Lin Xiang; Hou Yi-jun; Cheng Ming-hua; Will Perrie

    2003-01-01

    This paper presents a high-resolution (2′×2′) numerical model of coastal coupled wave-current interaction with explicit consideration of the effects of wave-current interaction on bottom stress. For two selected storms with measured data in the Yellow River coastal area of the Bohai Sea, it is shown that the bottom stress calculated by using a coupled wave-current model is increased, as one would expect, compared with the bottom stress computed with an uncoupled current model. Moreover, the current velocity field is also changed, but the corresponding current directions show less influence in the two simulations. The extents of changes in bottom stress and current velocity vary with storm intensities. The results further imply that the coupled wave-current model should be used as the basis for simulating the current velocity and sea level in the near shore region.

  6. Ocean Bottom Seismometers technology: current state and future outlook

    Science.gov (United States)

    Ilinskiy, Dmitry; Ganzha, Oleg

    2016-04-01

    conditions, since it minimizes working time, hence cuts the costs related to the expensive ship time. One of the major factors of success is the development of a reliable pop-up mechanism, which includes not only unfailing hydro-acoustic communication, but also a reliable disconnector, both electrochemical and mechanical that could be used in salt and sweet waters. The extensive operational experience helped us to determine the reasons for non-emersion of the stations. The main problem was a sucking of instruments by muddy bottom sediments, and a simple spring assembly can release the station from the anchor with high probability Secondly, the newly developed software provides the great opportunity to reduce considerably the processing and interpretation time cycle. The calculation of forward kinematic problems can be performed on the notebook in seconds. Visualization tools render color images of gathers with various processing parameters. All mentioned above are proved by real data acquired by GNS during active and passive seismic surveys in deep and shallow waters. GNS has the pool of 65 OBS for large scale crustal 2D/3D active or passive experiments in any part World Ocean.

  7. Eddy current testing system for bottom mounted instrumentation welds

    Directory of Open Access Journals (Sweden)

    Kobayashi Noriyasu

    2015-01-01

    Full Text Available The capability of eddy current testing (ECT for the bottom mounted instrumentation (BMI weld area of reactor vessel in a pressurized water reactor was demonstrated by the developed ECT system and procedure. It is difficult to position and move the probe on the BMI weld area because the area has complexly curved surfaces. The space coordinates and the normal vectors at the scanning points were calculated as the scanning trajectory of probe based on the measured results of surface shape on the BMI mock-up. The multi-axis robot was used to move the probe on the mock-up. Each motion-axis position of the robot corresponding to each scanning point was calculated by the inverse kinematic algorithm. In the mock-up test, the probe was properly contacted with most of the weld surfaces. The artificial stress corrosion cracking of approximately 6 mm in length and the electrical-discharge machining slit of 0.5 mm in length, 1 mm in depth and 0.2 mm in width given on the weld surface were detected. From the probe output voltage, it was estimated that the average probe tilt angle on the surface under scanning was 2.6°.

  8. Sedimentation and near-bottom currents in the South-Western Atlantic

    Science.gov (United States)

    Emelyanov, Emelyan M.

    2008-01-01

    The aims of the paper are: 1) to study the bottom relief and Late Quaternary bottom sediments of the South-Western Atlantic from the Amazon cone to the Vema Channel and Rio Grande Rise, and 2) to reconstruct recent and palaeo-Antarctic near-bottom currents (AABW). For this purpose, we used three main Parasound seismic profiles: 30 cores (up to 500 cm in length), the nanoplankton stratigraphy of 9 cores from the Brazilian lithological profile (along 24 °W), and literature sources. No soft sedimentes were found in the Vema channel; the bottom of the channel is acoustically "hard". Our geological data confirm that AABW flows mainly through this channel. The velocity of this flow should be higher than 100 cm.s-1. Only this strong current is able to rewash not only soft Holocene sediments, but also consolidated Quaternary deposits. Soft layered sediments occur at a depth less than 4200 m in the Hunter channel. Consequently, the AABW is able to flow from the Argentine Basin to the Brazil Basin only at a depth of more than 4200 m in this channel. Brown red clay or yellowish gray miopelagic clay prevail in the Brazil Deep. The age of red clay in the cores is different: Early or Late Pleistocene, or Holocene. Clay was rewashed and re-deposited in many areas of the deep. This means that the hydrodynamics sometimes was very active at a depth of 4000-5000 m in the Brazil Deep. The presence of conturite and turbidite interlayers in the red clay of the S. America continental base confirms the occurrence of a strong jet of the AABW (Deep Western Boundary current - DWBC) here. Antarctic and other diatoms were brought by AABW from Antarctica up to 10-5 °S. An unusual Pleistocene Ethmodiscus rex ooze was discovered at the latitude of 20 °S. Our data confirm the occurrence in the area between 10-5 °S of two mid-oceanic channels, one of them (EMOC) being located on a large sedimentary swell. The AABW in the cross-section from the Amazon River to the MAR flows through the Nara

  9. A low-power current self-adjusted VCO using a bottom PMOS current source

    Science.gov (United States)

    Zhixiong, Sheng; Fengqi, Yu

    2014-09-01

    This paper presents the design and implementation of a current self-adjusted VCO with low power consumption. In the proposed VCO, a bottom PMOS current source instead of a top one is adopted to decrease the tail noise. A current self-adjusted technique without additional external control signals is taken to ensure the VCO starts up in the whole band while keeping the power consumption relatively low. Meanwhile, the phase noise of the VCO at the low frequency (high Cvar) can be reduced by the technique. The circuit is implemented in 0.18 μm CMOS technology. The proposed VCO exhibits low power consumption of < 1.6 mW at a 1.5 V supply voltage and a tuning range from 11.79 to 12.53 GHz. The measured phase noise at 1 MHz offset from the frequency 11.79 GHz is -104.7 dBc/Hz, and the corresponding FOM is -184.2 dBc/Hz.

  10. Bottom currents and shelf sediments, southwest of Britain

    Science.gov (United States)

    Hamilton, D.; Sommerville, J. H.; Stanford, P. N.

    1980-04-01

    The shelf sediments southwest of Britain range from large boulders to muddy fine sands. The large boulders, which occur in patches, were probably dropped from icebergs. A reworked basal bed forms an extensive pavement over which well to very well sorted medium to fine sands are transported, whilst muddy sediments occur between sandbanks. Measurements of boundary layer currents show that the threshold friction velocities for the sands are exceeded by maximum tidal flows over most of the area. Repeated selective entrainment by tidal currents, in a virtually closed sediment system, is proposed as the mechanism for the formation of these very well sorted mobile sands, which have a mean size close to that of the most easily entrained grains and size frequency distributions approaching log-normality.

  11. Net currents in the wave bottom boundary layer: on waveshape streaming and progressive wave streaming

    NARCIS (Netherlands)

    Kranenburg, W.M.; Ribberink, J.S.; Uittenbogaard, R.E.; Hulscher, S.J.M.H.

    2012-01-01

    The net current (streaming) in a turbulent bottom boundary layer under waves above a flat bed, identified as potentially relevant for sediment transport, is mainly determined by two competing mechanisms: an onshore streaming resulting from the horizontal non-uniformity of the velocity field under pr

  12. Generalized Mean-Flow Theory of Wave-Current-Bottom Interactions

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The interaction between waves, currents and bottoms in estuarine and coastal regions is ubiquitious, in particular the dynamic mechanism of waves on large-scale slowly varying currents. The wave action concept may be extended and applicated to the study of the mechanism. Considering the effects of moving bottoms and starting from the Navier-Stokes equation of motion of a viscous fluid including the Coriolis force, a generalized mean-flow model theory for the nearshore region, that is, a set of mean-flow equations and their generalized wave action equation involving the three new kinds of actions termed respectively as the current wave action, the bottom wave action and the dissipative wave action which can be applied to arbitrary depth over moving bottoms and ambient currents with a typical vertical structure, is developed by vertical integration and time-averaging over a wave period, thus extending the classical concept, wave action, from the ideal averaged flow conservative system to the real averaged flow dissipative dynamical system, and having a large range of application.

  13. Experiments on Interaction Between Current-Induced Vibration and Scour of Submarine Pipelines on Sandy Bottom

    Institute of Scientific and Technical Information of China (English)

    SHEN Zhonghan; LIU Yubiao; LI Qingping; HUANG Qinghua; ZHU Farong

    2000-01-01

    In order to understand the dynamic behavior of submarine pipelines exposed to current and the mechanism of the interaction between current-induced vibration and scour of pipelines on a sandy bottom, an experimental investigation is conducted with a small scale model. A test model which can be testedin the flume is set up by taking into account the typical working conditions of the pipelines and by applying the similarity theory. The interactions between the shape of the scour hole and the behavior of the pipeline as well as the flow patterns of the current are detailed, and the interaction mechanism outlined.The effect of vibration of the pipeline on the development of dynamic scour at different stages is found out. The proposed experimental method and test results provide an effective means for design of marine pipelines against scouring.

  14. Pliocene-Quaternary contourite depositional system along the south-western Adriatic margin: changes in sedimentary stacking pattern and associated bottom currents

    Science.gov (United States)

    Pellegrini, Claudio; Maselli, Vittorio; Trincardi, Fabio

    2016-02-01

    The Pliocene-Quaternary history of the south-western Adriatic margin, represented by a complex contourite depositional system, records the palaeoceanography of the basin and the interactions between oceanographic processes and the uneven slope morphology that resulted from tectonic deformation. Three main stages can be recognized: (1) during the Pliocene, a giant sediment drift formed on the southern flank of the slope-transverse Gondola anticline that focused and accelerated the flow of slope-parallel bottom currents; (2) since the early to middle Pleistocene transition, a reorganization of bottom-current pathways led to a sharp change in the sedimentary architecture of the margin that became dominated by the growth of contourite deposits; (3) as of 350 ka, landward-migrating contourites on the outer shelf (less than 120 m water depth) reflect the presence of bottom currents also in shallow waters. This analysis of the sedimentary stacking pattern of the contourite depositional system that developed along the south-western Adriatic margin since the Pliocene enables disentangling the processes that controlled changes in bottom-current activity, demonstrating that bottom-current deposits constitute the bulk of depositional sequences at the Milankovitch timescale.

  15. Characterizing Wave- and Current-Induced Bottom Shear Stress: U.S. Middle Atlantic Bight

    Science.gov (United States)

    Dalyander, S.; Butman, B.

    2011-12-01

    The combined action of waves and currents at the seabed creates bottom shear stress, impacting local geology, habitat, and anthropogenic use. In this study, a methodology is developed to characterize the magnitude of benthic disturbance based on spatially and seasonally-resolved statistics (mean, standard deviation, 95th percentile) of wave-current bottom shear stress. The frequency of stress forcing is used to distinguish regions dominated by storms (return interval longer than 33 hours) from those dominated by the tides (periods shorter than 33 hours). In addition, the relative magnitude of the contribution to stress from waves, tides, and storm-driven currents is investigated by comparing wave stress, tidal current stress, and stress from the residual current (currents with tides removed), as well as through cross-correlation of wave and current stress. The methodology is applied to numerical model time-series data for the Middle Atlantic Bight (MAB) off the U.S. East Coast for April 2010 to April 2011; currents are provided from the Integrated Ocean Observing System (IOOS) operational hydrodynamic forecast Experimental System for Predicting Shelf and Slope Optics (ESPreSSO) and waves are provided from a Simulating WAves Nearshore (SWAN) hindcast developed for this project. Spatial resolution of the model is about 5 km and time-series wave and current data are at 1 and 2-hours respectively. Regions of the MAB delineated by stress characteristics include a tidally-dominated shallow region with relative high stress southeast of Massachusetts over Nantucket Shoals; a coastal band extending offshore to about 30 m water depth dominated by waves; a region dominated by waves and wind-driven currents offshore of the Outer Banks of North Carolina; and a low stress region southeast of Long Island, approximately coincident with an area of fine-grained sediments called the "Mud Patch". Comparison of the stress distribution with surface sediment texture data shows that

  16. Variations in the Holocene North Atlantic Bottom Current Strength in the Charlie Gibbs Fracture Zone

    Science.gov (United States)

    Kissel, C.; Van Toer, A.; Cortijo, E.; Turon, J.

    2011-12-01

    The changes in the strength of the North Atlantic bottom current during the Holocene period is presented via the study of cores located at the western termination of the northern deep channel of the Charlie-Gibbs fracture zone. This natural roughly E-W corridor is bathed by the Iceland-Scotland overflow water (ISOW) when it passes westward out of the Iceland Basin into the western North Atlantic basin. At present, it is also described as the place where southern sourced silicate-rich Lower Deep Water (LDW) derived from the Antarctic Bottom Waters (AABW) are passing westward, mixing with the ISOW. We conducted a deep-water multiproxy analysis on two nearby cores, coupling magnetic properties, anisotropy, sortable silt and benthic foraminifera isotopes. The first core had been taken by the R. V. Charcot in 1977 and the second one is a CASQ core taken during the IMAGES-AMOCINT MD168- cruise in the framework of the 06-EuroMARC-FP-008 Project on board the R.V. Marion Dufresne (French Polar Institute, IPEV) in 2008. The radiocarbon ages indicate an average sedimentation rate of about 50 cm/kyr through middle and late Holocene allowing a data resolution ranging from 40 to 100 years depending on the proxy. In each core, we observe long-term and short-term changes in the strength of the bottom currents. On the long term, a decrease in the amount of magnetic particles (normalized by the carbonate content) is first from 10 kyr to 8.6 kyr and then between 6 and 2 kyrs before reaching a steady state. Following Kissel et al. (2009), this indicates a decrease in the ISOW strength. The mean sortable silt shows exactly the same pattern indicating that not only the intensity of the ISOW but the whole deep water mass bathing the sites has decreased. On the short term, a first very prominent event centered at about 8.4 kyr (cal. ages) is marked by a pronounced minima in magnetic content and the smaller mean sortable silt sizes. This is typical for an abrupt reduction in deep flow

  17. On the numerical resolution of the bottom layer in simulations of oceanic gravity currents

    Directory of Open Access Journals (Sweden)

    N. Laanaia

    2010-06-01

    Full Text Available The role of an increased numerical vertical resolution, leading to an explicit resolution of the bottom Ekman layer dynamics, is investigated. Using the hydrostatic ocean model NEMO-OPA9, we demonstrate that the dynamics of an idealised gravity current (on an inclined plane, is well captured when a few (around five sigma-coordinate levels are added near the ocean floor. Such resolution allows to considerably improve the representation of the descent and transport of the gravity current and the Ekman dynamics near the ocean floor, including the important effect of Ekman veering, which is usually neglected in today's simulations of the ocean dynamics.

    Results from high resolution simulations (with σ and z-coordinates are compared to simulations with a vertical resolution commonly employed in today's ocean models. The latter show a downslope transport that is reduced by almost an order of magnitude and the decrease in the along slope transport is reduced six-fold. We strongly advocate for an increase of the numerical resolution at the ocean floor, similar to the way it is done at the ocean surface and at the lower boundary in atmospheric models.

  18. On the numerical resolution of the bottom layer in simulations of oceanic gravity currents

    Directory of Open Access Journals (Sweden)

    N. Laanaia

    2010-03-01

    Full Text Available The role of an increased numerical vertical resolution, leading to an explicit resolution of the bottom Ekman layer dynamics, is investigated. Using the hydrostatic ocean model NEMO-OPA9, we demonstrate that the dynamics of an idealised gravity current (on an inclined plane, is well captured when a few (around five sigma-coordinate levels are added near the ocean floor. Such resolution allows to considerably improve the representation of the descent and transport of the gravity current and the Ekman dynamics near the ocean floor, including the important effect of Ekman veering, which is usually neglected in today's simulations of the ocean dynamics.

    Results from high resolution simulations (with σ and z-coordinates are compared to simulations with a vertical resolution commonly employed in today's ocean models. The latter show a downslope transport that is reduced by almost an order of magnitude and the decrease in the along slope transport is reduced six-fold. We strongly advocate for an increase of the numerical resolution at the ocean floor, similar to the way it is done at the ocean surface and at the lower boundary in atmospheric models.

  19. Characteristics of low-frequency components of the near-bottom current in the Chinese Pioneer Area

    Institute of Scientific and Technical Information of China (English)

    LIANG Chujin; HOU Yijun; CHEN Qi; DONG Ruzhou; DONG Lixian

    2004-01-01

    Two deep-sea moorings were deployed respectively in the east area and the west area of Chinese Pioneer Area (CPA) in the tropic east Pacific to monitor the regional deep-sea dynamics below 600 meters above bottom (mab) from July 1997 to Oct. 1999. Results of statistics, spectral estimate and correlation analysis of the low-passed velocity data show that time scales of low-frequency components of the near-bottom currents are 25~120 days, in which 51-day period dominates the lower band of the frequency domain. Topographic features have obvious effect on low-frequency currents below 50 mab; modulations of the bottom-intensified sheared mean flow to the low-frequency currents are the dynamic mechanism of the frequency shift that occurs in both the east-area and the west-area.

  20. Current Research Activities.

    Science.gov (United States)

    1975-02-01

    King, Frederick Van Zee , James Kisker, Dale Walline, Paul 9 Krogslund, Kathy Watkins, J. Boyce I, SUMMARY OF CURRENT RESEARCH I. Dynamics and...group from the University of Mexico set up arrays of seismo- meters to detect the sound waves generated by the explosions at sea. By combining our...instruments have been used also to supplement sonobuoy data in an extensive survey of crustal structure near the East Pacific Rise off Mexico , in some

  1. Continuous river discharge monitoring with bottom-mounted current profilers at narrow tidal estuaries

    Science.gov (United States)

    Garel, E.; D'Alimonte, D.

    2017-02-01

    The objective of this study is to verify whether accurate and continuous estimates of freshwater discharge at the mouth of a narrow estuary with a single channel can be obtained from a bottom-mounted current profiler (ADCP). The focus is on moderate- to high-discharge events that significantly affect the water circulation corresponding to low river flow conditions. Observations at the Guadiana Estuary (southern Iberia) indicate lateral subtidal flow variability, constant cross-channel area, and quasi-steady response of the axial velocity to discharge events. Based on the concept of maximum entropy, the mean and maximum channel velocities were related by a constant ratio, Ω, using data from three cross-channel surveys. This relationship was then used to estimate the freshwater discharge at the mouth based on the maximum velocity obtained from the detided ADCP velocity profiles. This approach was possible because the ADCP was deployed near the position of maximum current velocity, that is, over the deepest part of the channel. The results show good correspondence with observations, indicating that the entropy model can complete or substitute the records from upstream gauged stations that do not include the contribution from downstream tributaries. A Multilayer Perceptron neural net (MLP) based on the entropy approach was then implemented with the purpose of estimating the discharge when Ω is unknown. This latter analysis showsthat the relationship between maximum velocity and discharge is quasi-stationary. Consequently, the MLP can successfully estimate freshwater runoff if the training data represent all statistical properties of the river discharge dynamics. The results also indicate that Ω may vary not only with concomitant hydrographic conditions, but also with the recent (i.e., several days prior) discharge magnitude.

  2. Bottom currents observed in and around a submarine valley on the continental slope of the northern South China Sea

    Science.gov (United States)

    Wu, Lunyu; Xiong, Xuejun; Li, Xiaolong; Shi, Maochong; Guo, Yongqing; Chen, Liang

    2016-12-01

    Bottom currents at about 1000 m depth in and around a submarine valley on the continental slope of the northern South China Sea were studied by a 14-month long experiment from July 2013 to September 2014. The observations reveal that bottom currents are strongly influenced by the topography, being along valley axis or isobaths. Power density spectrum analysis shows that all the currents have significant peaks at diurnal and semi-diurnal frequencies. Diurnal energy is dominant at the open slope site, which is consistent with many previous studies. However, at the site inside the valley the semi-diurnal energy dominates, although the distance between the two sites of observation is quite small (11 km) compared to a typical horizontal first-mode internal tide wavelength (200 km). We found this phenomenon is caused by the focusing of internal waves of certain frequencies in the valley. The inertial peak is found only at the open slope site in the first deployment but missing at the inside valley site and the rest of the deployments. Monthly averaged residual currents reveal that the near-bottom currents on the slope flow southwestward throughout the year except in August and September, 2013, from which we speculate that this is a result of the interaction between a mesoscale eddy and the canyon/sag topography. Currents inside the valley within about 10 mab basically flow along slope and in the layers above the 10 mab the currents are northwestward, that is, from the deep ocean to the shelf. The monthly mean current vectors manifest an Ekman layer-like vertical structure at both sites, which rotate counter-clockwise looking from above.

  3. Bottom Currents Observed in and Around a Submarine Valley on the Continental Slope of the Northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    WU Lunyu; XIONG Xuejun; LI Xiaolong; SHI Maochong; GUO Yongqing; CHEN Liang

    2016-01-01

    Bottom currents at about 1000m depth in and around a submarine valley on the continental slope of the northern South China Sea were studied by a 14-month long experiment from July 2013 to September 2014. The observations reveal that bottom currents are strongly influenced by the topography, being along valley axis or isobaths. Power density spectrum analysis shows that all the currents have significant peaks at diurnal and semi-diurnal frequencies. Diurnal energy is dominant at the open slope site, which is consistent with many previous studies. However, at the site inside the valley the semi-diurnal energy dominates, although the distance between the two sites of observation is quite small (11km) compared to a typical horizontal first-mode internal tide wavelength (200km). We found this phenomenon is caused by the focusing of internal waves of certain frequencies in the valley. The inertial peak is found only at the open slope site in the first deployment but missing at the inside valley site and the rest of the de-ployments. Monthly averaged residual currents reveal that the near-bottom currents on the slope flow southwestward throughout the year except in August and September, 2013, from which we speculate that this is a result of the interaction between a mesoscale eddy and the canyon/sag topography. Currents inside the valley within about 10mab basically flow along slope and in the layers above the 10mab the currents are northwestward, that is, from the deep ocean to the shelf. The monthly mean current vectors manifest an Ek-man layer-like vertical structure at both sites, which rotate counter-clockwise looking from above.

  4. Novel Method for Sizing Metallic Bottom Crack Depth Using Multi-frequency Alternating Current Potential Drop Technique

    Directory of Open Access Journals (Sweden)

    Li Yuting

    2015-10-01

    Full Text Available Potential drop techniques are of two types: the direct current potential drop (DCPD technique and alternating current potential drop (ACPD technique, and both of them are used in nondestructive testing. ACPD, as a kind of valid method in sizing metal cracks, has been applied to evaluate metal structures. However, our review of most available approaches revealed that some improvements can be done in measuring depth of metal bottom crack by means of ACPD, such as accuracy and sensitivity of shallow crack. This paper studied a novel method which utilized the slope of voltage ratio-frequency curve to solve bottom crack depth by using a simple mathematic equation based on finite element analysis. It is found that voltage ratio varies linearly with frequency in the range of 5-15 Hz; this range is slightly higher than the equivalent frequency and lower than semi-permeable frequency. Simulation and experiment show that the novel method can measure the bottom crack depth accurately.

  5. Simulation for Path Planning of SLOCUM Glider in Near-bottom Ocean Currents Using Heuristic Algorithms and Q-Learning

    Directory of Open Access Journals (Sweden)

    Utkarsh Gautam

    2015-05-01

    Full Text Available Addressing the need for exploration of benthic zones utilising autonomous underwater vehicles, this paper presents a simulation for an optimised path planning from the source node to the destination node of the autonomous underwater vehicle SLOCUM Glider in near-bottom ocean environment. Near-bottom ocean current data from the Bedford Institute of Oceanography, Canada, have been used for this simulation. A cost function is formulated to describe the dynamics of the autonomous underwater vehicle in near-bottom ocean currents. This cost function is then optimised using various biologically-inspired algorithms such as genetic algorithm, Ant Colony optimisation algorithm and particle swarm optimisation algorithm. The simulation of path planning is also performed using Q-learning technique and the results are compared with the biologically-inspired algorithms. The results clearly show that the Q-learning algorithm is better in computational complexity than the biologically-inspired algorithms. The ease of simulating the environment is also more in the case of Q-learning techniques. Hence this paper presents an effective path planning technique, which has been tested for the SLOCUM glider and it may be extended for use in any standard autonomous underwater vehicle.Defence Science Journal, Vol. 65, No. 3, May 2015, pp.220-225, DOI: http://dx.doi.org/10.14429/dsj.65.7855

  6. Sediment movement along the U.S. east coast continental shelf-I. Estimates of bottom stress using the Grant-Madsen model and near-bottom wave and current measurements

    Science.gov (United States)

    Lyne, V.D.; Butman, B.; Grant, W.D.

    1990-01-01

    Bottom stress is calculated for several long-term time-series observations, made on the U.S. east coast continental shelf during winter, using the wave-current interaction and moveable bed models of Grant and Madsen (1979, Journal of Geophysical Research, 84, 1797-1808; 1982, Journal of Geophysical Research, 87, 469-482). The wave and current measurements were obtained by means of a bottom tripod system which measured current using a Savonius rotor and vane and waves by means of a pressure sensor. The variables were burst sampled about 10% of the time. Wave energy was reasonably resolved, although aliased by wave groupiness, and wave period was accurate to 1-2 s during large storms. Errors in current speed and direction depend on the speed of the mean current relative to the wave current. In general, errors in bottom stress caused by uncertainties in measured current speed and wave characteristics were 10-20%. During storms, the bottom stress calculated using the Grant-Madsen models exceeded stress computed from conventional drag laws by a factor of about 1.5 on average and 3 or more during storm peaks. Thus, even in water as deep as 80 m, oscillatory near-bottom currents associated with surface gravity waves of period 12 s or longer will contribute substantially to bottom stress. Given that the Grant-Madsen model is correct, parameterizations of bottom stress that do not incorporate wave effects will substantially underestimate stress and sediment transport in this region of the continental shelf. ?? 1990.

  7. Sediment movement along the U.S. east coast continental shelf—I. Estimates of bottom stress using the Grant-Madsen model and near-bottom wave and current measurements

    Science.gov (United States)

    Lyne, Vincent D.; Butman, Bradford; Grant, William D.

    1990-05-01

    Bottom stress is calculated for several long-term time-series observations, made on the U.S. east coast continental shelf during winter, using the wave-current interaction and moveable bed models of GRANT and MADSEN (1979, Journal of Geophysical Research, 84, 1797-1808; 1982, Journal of Geophysical Research, 87, 469-482). The wave and current measurements were obtained by means of a bottom tripod system which measured current using a Savonius rotor and vane and waves by means of a pressure sensor. The variables were burst sampled about 10% of the time. Wave energy was reasonably resolved, although aliased by wave groupiness, and wave period was accurate to 1-2 s during large storms. Errors in current speed and direction depend on the speed of the mean current relative to the wave current. In general, errors in bottom stress caused by uncertainties in measured current speed and wave characteristics were 10-20%. During storms, the bottom stress calculated using the Grant-Madsen models exceeded stress computed from conventional drag laws by a factor of about 1.5 on average and 3 or more during storm peaks. Thus, even in water as deep as 80 m, oscillatory near-bottom currents associated with surface gravity waves of period 12 s or longer will contribute substantially to bottom stress. Given that the Grant-Madsen model is correct, parameterizations of bottom stress that do not incorporate wave effects will substantially underestimate stress and sediment transport in this region of the continental shelf.

  8. Nonlocal impacts of the Loop Current on cross-slope near-bottom flow in the northeastern Gulf of Mexico

    Science.gov (United States)

    Nguyen, Thanh-Tam; Morey, Steven L.; Dukhovskoy, Dmitry S.; Chassignet, Eric P.

    2015-04-01

    Cross-slope near-bottom motions near De Soto Canyon in the northeastern Gulf of Mexico are analyzed from a multidecadal ocean model simulation to characterize upwelling and downwelling, important mechanisms for exchange between the deep ocean and shelf in the vicinity of the 2010 BP Macondo well oil spill. Across the continental slope, large-scale depression and offshore movement of isopycnals (downwelling) occur more frequently when the Loop Current impinges upon the West Florida Shelf slope farther south. Upwelling and onshore movement of isopycnals occurs with roughly the same likelihood regardless of Loop Current impingement on the slope. The remote influence of Loop Current on the De Soto Canyon region downwelling is a consequence of a high-pressure anomaly that extends along the continental slope emanating from the location of Loop Current impact.

  9. Bottom current processes along the Iberian continental margin; Procesos sedimentarios por corrientes de fondo a lo largo del margen continental iberico

    Energy Technology Data Exchange (ETDEWEB)

    Llave, E.; Hernandez-Molina, F. J.; Ercilla, G.; Roque, C.; Van Rooij, D.; Garcia, M.; Juan, C.; Mena, A.; Brackenridge, R.; Jane, G.; Stow, D.; Gomez-Ballesteros, M.

    2015-07-01

    The products of bottom current circulation around the Iberian continental margin are characterised by large erosional and depositional features formed under a variety of geological and oceanographic contexts. The Iberian margins are influenced by several water masses that mainly interact along the upper and middle con- tinental slopes, as well as along the lower slope with the abyssal plains being influenced to a lesser extent. The main depositional features occur along the Ceuta Contourite Depositional System (CDS) within the SW Alboran Sea, in the Gulf of Cadiz (the most studied so far), the western margins of the Portugal/Galician mar- gin, the Ortegal Spur and the Le Danois Bank or Cachucho. Moreover, erosional contourite features have also been recently indentified, most notably terraces, abraded surfaces, channels, furrows and moats. The majority of these features are formed under the influence of the Mediterranean water masses, especially by the interaction of the Mediterranean Outflow Water (MOW) with the seafloor. The MOW is characterized as relatively warm (13 degree centigrade) and with a high salinity (∼36.5), giving it a high density relative to the surrounding water masses, hence constituting an important contribution to the global thermohaline circulation, making it one of the most studied water masses surrounding Iberia. The development of both depositional and ero- sional contourite features does not only depend on the bottom-current velocity but also on several other important controlling factors, including: 1) local margin morphology affected by recent tectonic activity; 2) multiple sources of sediment supply; 3) water-mass interphases interacting with the seafloor; and 4) glacioeustatic changes, especially during the Quaternary, when the increasing influence of the bottom cur- rent has been observed during the cold stages. The main objective of this special volume contribution is to provide a review and description of the regional along

  10. Turbulent structures dependent on tidal currents in the bottom boundary layer of the Venice Lagoon

    Energy Technology Data Exchange (ETDEWEB)

    Cavazzoni, S.; Crosera, F.

    The time series of horizontal and vertical turbulent velocity fluctuations u', w' have been recorded by means of an electromagnetic currentmeter in proximity of the bottom of a channel feeding the Venetian Lagoon. Simultaneous surface gradients have been recorded at two tide gauge stations, one upstream and the other downstream of the chosen test site. The time series of u', w' and u'w' values have been analysed using standard digital methods and, for each record, spectra, cross-spectra, co-spectra, quadrature spectra, phase and coherence of u' and w' have been computed. This analysis allows us to determine temporal and spatial dimensions of turbulent structures that give the greatest contribution to Reynolds stress (- rhoanti u'anti w', where rho is the water density). These structures that seem to be dependent on longitudinal surface gradients are primarily responsible for vertical momentum transport and, consequently, for the lift-up and transport of sediments. Statistic distributions of u', w' and u'w' values indicate that the greatest turbulent structures are those with u'w'<0 and with u'<0 predominating.

  11. Effects of wire-bottom caging on heart rate, activity and body temperature in telemetry-implanted rats.

    Science.gov (United States)

    Giral, Marta; García-Olmo, Dolores C; Kramer, Klaas

    2011-10-01

    Some experimental procedures are associated with placement of animals in wire-bottom cages. The goal of this study was to evaluate stress-related physiological parameters (heart rate [HR], body temperature [BT], locomotor activity [LA], body weight [BW] and food consumption) in rats under two housing conditions, namely in wire-bottom cages and in bedding-bottom cages. Telemetry devices were surgically implanted in male Sprague-Dawley rats. HR, BT and LA were recorded at 5 min intervals. Analysis under each housing condition was performed from 16:00 to 08:00 h of the following day (4 h light, 12 h dark). During almost all of the light phase, the HR of rats housed in wire-bottom cages remained high (371 ± 35 bpm; mean ± SD; n = 6) and was significantly different from that of rats housed in bedding-bottom cages (340 ± 29 bpm; n = 6; P wire-bottom cages, BT tended to fluctuate more widely during the dark phase. LA decreased when animals were housed in wire-bottom cages, in particular during the dark phase. Moreover, there was a significant difference with respect to the gain in BW: BW of rats housed in bedding-bottom cages increased 12 ± 2 g, whereas that of rats in wire-bottom cages decreased by 2 ± 3 g (P wire-bottom cages overnight leads to immediate alterations of HR, BW and LA, which might be related to a stress response.

  12. Optimal Environmental Conditions and Anomalous Ecosystem Responses: Constraining Bottom-up Controls of Phytoplankton Biomass in the California Current System

    Science.gov (United States)

    Jacox, Michael G.; Hazen, Elliott L.; Bograd, Steven J.

    2016-06-01

    In Eastern Boundary Current systems, wind-driven upwelling drives nutrient-rich water to the ocean surface, making these regions among the most productive on Earth. Regulation of productivity by changing wind and/or nutrient conditions can dramatically impact ecosystem functioning, though the mechanisms are not well understood beyond broad-scale relationships. Here, we explore bottom-up controls during the California Current System (CCS) upwelling season by quantifying the dependence of phytoplankton biomass (as indicated by satellite chlorophyll estimates) on two key environmental parameters: subsurface nitrate concentration and surface wind stress. In general, moderate winds and high nitrate concentrations yield maximal biomass near shore, while offshore biomass is positively correlated with subsurface nitrate concentration. However, due to nonlinear interactions between the influences of wind and nitrate, bottom-up control of phytoplankton cannot be described by either one alone, nor by a combined metric such as nitrate flux. We quantify optimal environmental conditions for phytoplankton, defined as the wind/nitrate space that maximizes chlorophyll concentration, and present a framework for evaluating ecosystem change relative to environmental drivers. The utility of this framework is demonstrated by (i) elucidating anomalous CCS responses in 1998-1999, 2002, and 2005, and (ii) providing a basis for assessing potential biological impacts of projected climate change.

  13. Optimal Environmental Conditions and Anomalous Ecosystem Responses: Constraining Bottom-up Controls of Phytoplankton Biomass in the California Current System.

    Science.gov (United States)

    Jacox, Michael G; Hazen, Elliott L; Bograd, Steven J

    2016-06-09

    In Eastern Boundary Current systems, wind-driven upwelling drives nutrient-rich water to the ocean surface, making these regions among the most productive on Earth. Regulation of productivity by changing wind and/or nutrient conditions can dramatically impact ecosystem functioning, though the mechanisms are not well understood beyond broad-scale relationships. Here, we explore bottom-up controls during the California Current System (CCS) upwelling season by quantifying the dependence of phytoplankton biomass (as indicated by satellite chlorophyll estimates) on two key environmental parameters: subsurface nitrate concentration and surface wind stress. In general, moderate winds and high nitrate concentrations yield maximal biomass near shore, while offshore biomass is positively correlated with subsurface nitrate concentration. However, due to nonlinear interactions between the influences of wind and nitrate, bottom-up control of phytoplankton cannot be described by either one alone, nor by a combined metric such as nitrate flux. We quantify optimal environmental conditions for phytoplankton, defined as the wind/nitrate space that maximizes chlorophyll concentration, and present a framework for evaluating ecosystem change relative to environmental drivers. The utility of this framework is demonstrated by (i) elucidating anomalous CCS responses in 1998-1999, 2002, and 2005, and (ii) providing a basis for assessing potential biological impacts of projected climate change.

  14. Current, temperature, salinity, and other data from bottom instrument packages off Wrightsville Beach, North Carolina, from 02 April 1996 to 22 May 1996 (NODC Accession 0066099)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Measurements of bottom currents and waves to investigate the flow field and sediment transport in a rippled scour depression offshore of Wrightsville Beach, NC.

  15. Effects of transient bottom water currents and oxygen concentrations on benthic exchange rates as assessed by eddy correlation measurements

    DEFF Research Database (Denmark)

    Holtappels, Moritz; Glud, Ronnie N.; Doris, Daphne

    2013-01-01

    Eddy correlation (EC) measurements in the benthic boundary layer (BBL) allow estimating benthic O2 uptake from a point distant to the sediment surface. This noninvasive approach has clear advantages as it does not disturb natural hydrodynamic conditions, integrates the flux over a large foot......-print area and allows many repetitive flux measurements. A drawback is, however, that the measured flux in the bottom water is not necessarily equal to the flux across the sediment-water interface. A fundamental assumption of the EC technique is that mean current velocities and mean O2 concentrations......, which is comparable to the O2 uptake of shelf sediments. Second, the case of transient velocities was examined with a 2D k-ε turbulence model demonstrating that the vertical flux can be biased by 30–100% for several hours during changing current velocities from 2 to 10 cm s−1. Results are compared...

  16. Current trends, innovations and issues in nursing education to cater for the bottom billion nurses

    Directory of Open Access Journals (Sweden)

    Pek-Hong Lim

    2012-07-01

    Full Text Available Nurse education is undergoing a processof transition. Nurses worldwide are working towardsachievement of higher levels of education and trainingthrough an improved education system. Current trendsand innovations in nursing education are emerging toprepare more nurses and to deliver education to studentsacross geographical boundaries while taking intoconsideration their work and family responsibilities. Thecurrent trends and innovations in nursing educationrange from full time face-to-face interactions to distanceeducation programmes. Teaching approaches such asblended learning, online or e-Learning have providednurses with an avenue for continuing education fordevelopment and progression in their career pathways.Every nurse aspires to reach her highest potential. Whilethe current trends and innovations in nursing educationprovides the flexibility for nurses to continue learningand upgrade their professional qualifications, there areissues to be considered in catering to the needs of thebottom billion nurses. An exploration of related issueswill include views from different perspectives, such asthat of the institution/provider, instructor/facilitatorand student/learner involved in the development andimplementation of the related education programmes.

  17. Effects of transient bottom water currents and oxygen concentrations on benthic exchange rates as assessed by eddy correlation measurements

    Science.gov (United States)

    Holtappels, Moritz; Glud, Ronnie N.; Donis, Daphne; Liu, Bo; Hume, Andrew; WenzhöFer, Frank; Kuypers, Marcel M. M.

    2013-03-01

    correlation (EC) measurements in the benthic boundary layer (BBL) allow estimating benthic O2 uptake from a point distant to the sediment surface. This noninvasive approach has clear advantages as it does not disturb natural hydrodynamic conditions, integrates the flux over a large foot-print area and allows many repetitive flux measurements. A drawback is, however, that the measured flux in the bottom water is not necessarily equal to the flux across the sediment-water interface. A fundamental assumption of the EC technique is that mean current velocities and mean O2 concentrations in the bottom water are in steady state, which is seldom the case in highly dynamic environments like coastal waters. Therefore, it is of great importance to estimate the error introduced by nonsteady state conditions. We investigated two cases of transient conditions. First, the case of transient O2 concentrations was examined using the theory of shear flow dispersion. A theoretical relationship between the change of O2 concentrations and the induced vertical O2 flux is introduced and applied to field measurements showing that changes of 5-10 μM O2 h-1 result in transient EC-fluxes of 6-12 mmol O2 m-2 d-1, which is comparable to the O2 uptake of shelf sediments. Second, the case of transient velocities was examined with a 2D k-ɛ turbulence model demonstrating that the vertical flux can be biased by 30-100% for several hours during changing current velocities from 2 to 10 cm s-1. Results are compared to field measurements and possible ways to analyze and correct EC-flux estimates are discussed.

  18. Agglutinated Foraminifera indicate a deep bottom current over the Hovgaard Ridge, West of Spitsbergen

    Science.gov (United States)

    Kaminski, Michael; Frank, Niessen

    2015-04-01

    The Hovgård Ridge is situated in Fram Strait, west of Spitsbergen. The ridge either represents a submerged fragment of continental crust or an upwarped fragmant of ocean crust within the Fram Strait. Its crest rises to a water depth of approx. 1170 m. During Expedition 87 of the Icebreaker POLARSTERN in August 2014, a sediment-echosounding profile was recorded and a boxcore station was collected from the crest of Hovgård Ridge at 1169 m water depth. The surficial sediment at this station consists of dark yellowish brown pebbly-sandy mud with a minor admixture of biogenic components in the coarse fraction. Patches of large tubular foraminifera and isolated pebbles were clearly visible on the sediment surface. The sediment surface of the boxcore was covered with patches of large (>1 mm diameter) large tubular astrorhizids belonging mostly to the species Astrorhiza crassatina Brady, with smaller numbers of Saccorhiza, Hyperammina, and Psammosiphonella. Non-tubular species consist mainly of opportunistic forms such as Psammosphaera and Reophax. The presence of large suspension-feeding tubular genera as well as opportunistic forms, as well as sediment winnowing, point to the presence of a deep current at this locality that is strong enough to disturb the benthic fauna. This is confirmed by data obtained from sediment echosounding, which exhibit lateral variation of relative sedimentation rates within the Pleistocene sedimentary drape covering the ridge indicative of winnowing in a south-easterly direction.

  19. Smart Novel Semi-Active Tuned Mass Damper for Fixed-Bottom and Floating Offshore Wind (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Tsouroukdissian, Arturo [Alstom Renewable US LLC

    2016-05-02

    The intention of this paper is to present the results of a novel smart semi-active tuned mass damper (SA-TMD), which mitigates unwanted loads for both fixed-bottom and floating offshore wind systems. (Presentation Format).

  20. Sedimentary record of postglacial variability in near-bottom currents, sediment supply and ice rafting on the continental shelf off SW Spitsbergen

    Science.gov (United States)

    Sternal, B.; Szczuciński, W.; Forwick, M.; ZajÄ czkowski, M.; Lorenc, S.; Vorren, T. O.

    2012-04-01

    The continental shelf off the west coast of southern Spitsbergen is influenced by the northward-flowing water masses (warmer and more saline Atlantic Water carried by the West Spitsbergen Current and colder, fresher Arctic Water carried by the East Spitsbergen Current), as well as ice rafting. The present study was conducted to identify the influence of these factors on the sedimentary environment and to decipher temporal variations in the intensity of bottom currents, ice rafting off and glacial activity on southwestern Spitsbergen during the past 14,000 years. The study is based on a multiproxy analyses of one gravity core from the outer continental shelf (148 m water depth) in decadal to centennial resolution. Age control was obtained on a basis of ten AMS 14C dates along with 210Pb and 137Cs datings. To infer the style of sedimentation and the sediment supply the core was measured for magnetic susceptibility, X-rayed, analysed for grain-size distribution of bulk sediment and for coarse sand fraction components. The assessment of ice rafting intensity was based on coarse sand fraction counting (IRD), whereas to assume the type of ice rafting, whether by icebergs or sea ice, the analysis of quartz grains roundness was performed. Moreover, relative velocity of bottom currents was estimated by grain-size analysis of sortable silt fraction. We distinguish seven intervals: c. 14,000 - 12,600 cal yr BP - Bølling/Allerød (unit 1); 12,600 - 11,500 cal yr BP - Younger Dryas (unit 2) and 11,500 cal yr BP to present - Holocene (units 3 - 7). The smallest mean sortable silt values, reflecting relatively low bottom current velocity, occurred from the Bølling/Allerød to the early Younger Dryas and after ~0.5 cal ka BP. Increased velocities were inferred for the early Holocene as well as period between 8.8 - 7.8 cal yr BP. The IRD was present throughout the entire record indicating continuous supply of a material delivered from ice rafting, with variable dominance of

  1. Active inrush-current limiter

    Science.gov (United States)

    Kichak, R. A.

    1977-01-01

    By stretching turn-on time from approximately 1 to 200 ms, effects of inrush current (and of associated large current spikes) and current rate of rise (dl/dt) are made potentially less severe. Limiter arrangement consists of time-variable impedance connected in series between input dc power source return and power circuit of converter.

  2. Comparison of bottom-track to global positioning system referenced discharges measured using an acoustic Doppler current profiler

    Science.gov (United States)

    Wagner, C.R.; Mueller, D.S.

    2011-01-01

    A negative bias in discharge measurements made with an acoustic Doppler current profiler (ADCP) can be caused by the movement of sediment on or near the streambed. The integration of a global positioning system (GPS) to track the movement of the ADCP can be used to avoid the systematic negative bias associated with a moving streambed. More than 500 discharge transects from 63 discharge measurements with GPS data were collected at sites throughout the US, Canada, and New Zealand with no moving bed to compare GPS and bottom-track-referenced discharges. Although the data indicated some statistical bias depending on site conditions and type of GPS data used, these biases were typically about 0.5% or less. An assessment of differential correction sources was limited by a lack of data collected in a range of different correction sources and different GPS receivers at the same sites. Despite this limitation, the data indicate that the use of Wide Area Augmentation System (WAAS) corrected positional data is acceptable for discharge measurements using GGA as the boat-velocity reference. The discharge data based on GPS-referenced boat velocities from the VTG data string, which does not require differential correction, were comparable to the discharges based on GPS-referenced boat velocities from the differentially-corrected GGA data string. Spatial variability of measure discharges referenced to GGA, VTG and bottom-tracking is higher near the channel banks. The spatial variability of VTG-referenced discharges is correlated with the spatial distribution of maximum Horizontal Dilution of Precision (HDOP) values and the spatial variability of GGA-referenced discharges is correlated with proximity to channel banks. ?? 2011 Published by Elsevier B.V.

  3. Friction and mixing effects on potential vorticity for bottom current crossing a marine strait: an application to the Sicily Channel (central Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    F. Falcini

    2014-11-01

    Full Text Available We discuss here the evolution of vorticity and potential vorticity (PV for a bottom current crossing a marine channel in shallow-water approximation, focusing on the effect of friction and mixing. We argue that bottom current vorticity is prone to significant sign changes and oscillations due to topographic effects when, in particular, the current flows over the sill of a channel. These vorticity variations are, however, modulated by frictional effects due to seafloor roughness and morphology. Such behavior is also reflected in the PV spatial evolution, which shows an abrupt peak around the sill region. Our theoretical findings are discussed by means of in situ hydrographic data related to the Eastern Mediterranean Deep Water, i.e., a dense, bottom water vein that flows northwestward, along the Sicily Channel (Mediterranean Sea. Indeed, the narrow sill of this channel implies that friction and entrainment need to be considered. Small tidal effects in the Sicily Channel allow for a steady theoretical approach. Our diagnoses on vorticity and PV allow us to obtain general insights about the effect of mixing and friction on the pathway and internal structure of bottom-trapped currents flowing through channels and straits, and to discuss spatial variability of the frictional coefficient. Our approach significantly differs from other PV-constant approaches previously used in studying the dynamics of bottom currents flowing through rotating channels.

  4. Holocene ice dynamics and bottom-water formation associated with Cape Darnley polynya activity recorded in Burton Basin, East Antarctica

    Science.gov (United States)

    Borchers, Andreas; Dietze, Elisabeth; Kuhn, Gerhard; Esper, Oliver; Voigt, Ines; Hartmann, Kai; Diekmann, Bernhard

    2016-03-01

    A multi-proxy study including sedimentological, mineralogical, biogeochemical and micropaleontological methods was conducted on sediment core PS69/849-2 retrieved from Burton Basin, MacRobertson Shelf, East Antarctica. The goal of this study was to depict the deglacial and Holocene environmental history of the MacRobertson Land-Prydz Bay region. A special focus was put on the timing of ice-sheet retreat and the variability of bottom-water formation due to sea ice formation through the Holocene. Results from site PS69/849-2 provide the first paleo-environmental record of Holocene variations in bottom-water production probably associated to the Cape Darnley polynya, which is the second largest polynya in the Antarctic. Methods included end-member modeling of laser-derived high-resolution grain size data to reconstruct the depositional regimes and bottom-water activity. The provenance of current-derived and ice-transported material was reconstructed using clay-mineral and heavy-mineral analysis. Conclusions on biogenic production were drawn by determination of biogenic opal and total organic carbon. It was found that the ice shelf front started to retreat from the site around 12.8 ka BP. This coincides with results from other records in Prydz Bay and suggests warming during the early Holocene optimum next to global sea level rise as the main trigger. Ice-rafted debris was then supplied to the site until 5.5 cal. ka BP, when Holocene global sea level rise stabilized and glacial isostatic rebound on MacRobertson Land commenced. Throughout the Holocene, three episodes of enhanced bottom-water activity probably due to elevated brine rejection in Cape Darnley polynya occured between 11.5 and 9 cal. ka BP, 5.6 and 4.5 cal. ka BP and since 1.5 cal. ka BP. These periods are related to shifts from warmer to cooler conditions at the end of Holocene warm periods, in particular the early Holocene optimum, the mid-Holocene warm period and at the beginning of the neoglacial. In

  5. Dense water cascading, bottom currents and sediment wave formation at the exit of the Bari canyon (Southern Adriatic Sea, Italy)

    Science.gov (United States)

    Langone, Leonardo; Miserocchi, Stefano; Boldrin, Alfredo; Turchetto, Margherita; Foglini, Federica; Trincardi, Fabio

    2010-05-01

    The dense water forming in the North Adriatic (NAdDW) spreading southward along the Italian continental shelf, sinks in the Southern Adriatic basin through particular cascading events. Such events are seasonal, occurring specially in April, with variable intensity. These phenomena control the water mass mixing, the deep ocean ventilation, the behaviour of deep ecosystems, the formation of complex erosive and depositional bedforms and the abyssal export and burial of nutrients and carbon. Because of the NadDW formation is linked to climate factors (frequency, duration and size of Bura winds), the temporal variations of the NadDW dispersion into the Southern Adriatic allow to make inferences of the impact of recent climate changes on the ecosystems of the deep Mediterranean Sea. Previous research projects (EuroStrataform, HERMES) acquired a large data set of bathymetric, side-scan sonar (TOBI) and Chirp sonar profiles, which were used to build detailed morpho-bathymetric maps of the Southern Adriatic margin. There, the seabed is extremely complex, characterized by a large variety of bedforms (sediment waves, erosive scours, longitudinal furrows and giant comet marks). A branch of the cascading NAdDW is confined and accelerated through the Bari canyon where it produces a strong current capable of reaching down-slope velocities greater than 60 cm s-1 near the bottom at ~600 m of water depth, eroding the canyon thalweg and entraining large amounts of fine-grained sediment. At the exit of the canyon, in water depth greater than 800 m, the current becomes less confined, spreads laterally and generates an 80-km2-wide field of mud waves; these bedforms migrate up current and show amplitudes up to 50 m and wavelengths of about 1 km. Cruise IMPACT-09 of RV Urania was carried out in the Southern Adriatic Sea from 17-30 March 2009 with main scope of studying the impact of NadDW cascading events on the deep ecosystems of the Southern Adriatic. Experiments planned in the cruise

  6. Pre-stimulus activity predicts the winner of top-down vs. bottom-up attentional selection.

    Directory of Open Access Journals (Sweden)

    Ali Mazaheri

    Full Text Available Our ability to process visual information is fundamentally limited. This leads to competition between sensory information that is relevant for top-down goals and sensory information that is perceptually salient, but task-irrelevant. The aim of the present study was to identify, from EEG recordings, pre-stimulus and pre-saccadic neural activity that could predict whether top-down or bottom-up processes would win the competition for attention on a trial-by-trial basis. We employed a visual search paradigm in which a lateralized low contrast target appeared alone, or with a low (i.e., non-salient or high contrast (i.e., salient distractor. Trials with a salient distractor were of primary interest due to the strong competition between top-down knowledge and bottom-up attentional capture. Our results demonstrated that 1 in the 1-sec pre-stimulus interval, frontal alpha (8-12 Hz activity was higher on trials where the salient distractor captured attention and the first saccade (bottom-up win; and 2 there was a transient pre-saccadic increase in posterior-parietal alpha (7-8 Hz activity on trials where the first saccade went to the target (top-down win. We propose that the high frontal alpha reflects a disengagement of attentional control whereas the transient posterior alpha time-locked to the saccade indicates sensory inhibition of the salient distractor and suppression of bottom-up oculomotor capture.

  7. Pre-stimulus activity predicts the winner of top-down vs. bottom-up attentional selection.

    Science.gov (United States)

    Mazaheri, Ali; DiQuattro, Nicholas E; Bengson, Jesse; Geng, Joy J

    2011-02-28

    Our ability to process visual information is fundamentally limited. This leads to competition between sensory information that is relevant for top-down goals and sensory information that is perceptually salient, but task-irrelevant. The aim of the present study was to identify, from EEG recordings, pre-stimulus and pre-saccadic neural activity that could predict whether top-down or bottom-up processes would win the competition for attention on a trial-by-trial basis. We employed a visual search paradigm in which a lateralized low contrast target appeared alone, or with a low (i.e., non-salient) or high contrast (i.e., salient) distractor. Trials with a salient distractor were of primary interest due to the strong competition between top-down knowledge and bottom-up attentional capture. Our results demonstrated that 1) in the 1-sec pre-stimulus interval, frontal alpha (8-12 Hz) activity was higher on trials where the salient distractor captured attention and the first saccade (bottom-up win); and 2) there was a transient pre-saccadic increase in posterior-parietal alpha (7-8 Hz) activity on trials where the first saccade went to the target (top-down win). We propose that the high frontal alpha reflects a disengagement of attentional control whereas the transient posterior alpha time-locked to the saccade indicates sensory inhibition of the salient distractor and suppression of bottom-up oculomotor capture.

  8. On active current selection for Lagrangian profilers

    DEFF Research Database (Denmark)

    Jouffroy, Jerome; Zhou, Qiuyang; Zielinski, Oliver

    2013-01-01

    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...... models for the profiler and the currents it will use. We then present simple feedback controllers that, using the direction of the currents and taking into account the configuration of the environment (coastal or deep-sea), is able to steer the profiler to any desired horizontal location. To illustrate...... the approach, a few results are presented using both simulated currents and real current velocities from the North Sea....

  9. "Bottom-up" transparent electrodes.

    Science.gov (United States)

    Morag, Ahiud; Jelinek, Raz

    2016-11-15

    Transparent electrodes (TEs) have attracted significant scientific, technological, and commercial interest in recent years due to the broad and growing use of such devices in electro-optics, consumer products (touch-screens for example), solar cells, and others. Currently, almost all commercial TEs are fabricated through "top-down" approaches (primarily lithography-based techniques), with indium tin oxide (ITO) as the most common material employed. Several problems are encountered, however, in this field, including the cost and complexity of TE production using top-down technologies, the limited structural flexibility, high-cost of indium, and brittle nature and low transparency in the far-IR spectral region of ITO. Alternative routes based upon bottom-up processes, have recently emerged as viable alternatives for production of TEs. Bottom up technologies are based upon self-assembly of building blocks - atoms, molecules, or nanoparticles - generating thin patterned films that exhibit both electrical conductivity and optical transparency. In this Feature Article we discuss the recent progress in this active and exciting field, including bottom-up TE systems produced from carbon materials (carbon nanotubes, graphene, graphene-oxide), silver, gold, and other metals. The current hurdles encountered for broader use of bottom-up strategies along with their significant potential are analyzed.

  10. Oceanic Density Fronts Steering Bottom-Current Induced Sedimentation Deduced from a 50 ka Contourite-Drift Record and Numerical Modeling (off NW Spain)

    Science.gov (United States)

    Hanebuth, T. J. J.; Zhang, W.; Hofmann, A. L.; Lowemark, L. A.; Schwenk, T.

    2015-12-01

    How bottom-near hydrographic and sedimentary processes control the formation of bottom-current related confined deep-sea depocenters remains widely speculative. The geological approach of this study uses a transect of sediment cores and sediment echosounder profiles across a whole contourite system off NW Spain. This "mounded patch"-type contourite drift (18 km long, 20 km wide) with a 150-m deep moat has formed around an 800-m high structural obstacle. Past deposition was characterized by alternating calm and high-energy bottom-flow conditions. Calm conditions (Last Glacial period: 27-17 cal ka BP; late Holocene times: current-influenced deposition of fine-grained sediments (10 µm) over the entire basin. In contrast, waxing-and-waning high-energy conditions (D/O events during Marine Isotope Stage 3; the Deglacial/early Holocene time interval at 17-4 cal ka BP) resulted in coarse grained (70 µm) deposition. Process-based numerical modelling demonstrates that pulse-like oceanic density fronts travelling within the transition zone of two water masses (Labrador Sea Water, Mediterranean Outflow Water) provide a powerful mechanism for contouritic deposition, rather than the core of a water mass itself. These gravity-driven density fronts lead to local re-suspension of sand from the moat and to subsequent upward transport over the crest. Here, the oceanic density fronts produce additional km-scale eddies. These migrating eddies provide an efficient mechanism for further widespread sediment re-distribution. In comparison with paleoceanographic reconstructions, a downward migration or expansion of the Mediterranean Outflow Water by about 300 m led most probably to such temporary contouritic sand deposition. We finally propose a conceptual model to explain how seafloor obstacles redirect and perturbate bottom currents. This model proposes water mass transition zone as an important high-energy medium, for oceanic density fronts to travel. On the respective time scale, the

  11. Current, temperature, backscatter, and other data from bottom instrument packages deployed from the RV Oceanus and other platforms in support of sediment transport observation in the Middle Atlantic Bight from 11 December 1975 to 30 October 1980 (NODC Accession 0066005)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A series of studies to assess environmental hazards to petroleum development in the Middle Atlantic Bight. Long-term observations of currents and near-bottom...

  12. Smart Novel Semi-Active Tuned Mass Damper for Fixed-Bottom and Floating Offshore Wind (Paper)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Tsouroukdissian, Arturo [Alstom Renewable US LLC (GE Subsidiary); Lackner, Mathew [University of Massachusetts; Cross-Whiter, John [Glosten Associates; Park, Se Myung [University of Massachusetts; Pourazarm, Pariya [University of Massachusetts; La Cava, William [University of Massachusetts; Lee, Sungho [Glosten Associates

    2016-05-02

    The intention of this paper is to present the results of a novel smart semi-active tuned mass damper (SA-TMD), which mitigates unwanted loads for both fixed-bottom and floating offshore wind systems. The paper will focus on the most challenging water depths for both fixed-bottom and floating systems. A close to 38m Monopile and 55m Tension Leg Platform (TLP) will be considered. A technical development and trade-off analysis will be presented comparing the new system with existing passive non-linear TMD (N-TMD) technology and semi-active. TheSATMD works passively and activates itself with low power source under unwanted dynamic loading in less than 60msec. It is composed of both variable stiffness and damping elements coupled to a central pendulum mass. The analysis has been done numerically in both FAST(NREL) and Orcaflex (Orcina), and integrated in the Wind Turbine system employing CAD/CAE. The results of this work will pave the way for experimental testing to complete the technology qualification process. The load reductions under extreme and fatigue cases reach up significant levels at tower base, consequently reducing LCOE for fixed-bottom to floating wind solutions. The nacelle acceleration is reduced substantially under severe random wind and sea states, reducing the risks of failure of electromechanical components and blades at the rotor nacelle assembly. The SA-TMD system isa new technology that has not been applied previously in wind solutions. Structural damping devices aim to increase offshore wind turbine system robustness and reliability, which eases multiple substructures installations and global stability.

  13. Current Activities of the ASME Subgroup NUPACK

    Energy Technology Data Exchange (ETDEWEB)

    Gerald M. Foster; D. Keith Morton; Paul McConnell

    2007-10-01

    Current activities of the American Society of Mechanical Engineers (ASME), Section III Subgroup on Containment Systems for Spent Fuel High-Level Waste Transport Packagings (also known as Subgroup NUPACK) are reviewed with emphasis on the recent revision of Subsection WB. Also, brief insightson new proposals for the development of rules for internal support structures and for a strain-based acceptance criteria are provided.

  14. Evidence for the Late Cenozoic Antarctic Ice Sheet evolution and bottom current dynamics in the central-western Ross Sea outer margin, Antarctica

    Science.gov (United States)

    Kim, Sookwan; De Santis, Laura; Kuk Hong, Jong; Cottlerle, Diego; Petronio, Lorenzo; Colizza, Ester; Bergamasco, Andrea; Kim, Young-Gyun; Kang, Seung-Goo; Kim, Hyoungjun; Kim, Suhwan; Wardell, Nigel; Geletti, Riccardo; McKay, Robert; Jin, Young Keun; Kang, Sung-Ho

    2016-04-01

    Sedimentary records in polar continental margins provide clues for understanding paleo-depositional environments, related to ice sheet evolution and bottom-water current dynamics, during times of past climate and global sea level changes. Previous seismostratigraphic studies of the Ross Sea embayment, Antarctica, illustrated its general stratigraphic framework and the distribution of glacial sedimentary features over the continental shelf, since the onset of Antarctic ice-sheets at the Eocene-Oligocene boundary (~34.0 Ma). In contrast, there are a fewer studies for the outer continental margin, where continuous sedimentary deposits generally preserve the record of past climate cycles with minimum hiatus, comparing to the inner- and mid-continental shelf, where grounding ice streams eroded most of the sediments. Here we present a seismostratigraphic analysis of 2-D multichannel seismic reflection profiles, from the Central Basin located in the central-western Ross Sea outer margin. A glacial prograding wedge developed at the mouth of the Joides Basin since early-middle Miocene times (RSU4: ~14.0 Ma). And the Central Basin was filled with stacked debris-flow deposits and turbidites. The sediment depocenter shifted from the Central Basin toward the slope in the Pliocene (after RSU2: ~3.3 Ma). Pliocene foreset beds are steep and pinch out at the base of the continental slope. Bottom current controlled sediment drifts well developed since the middle Miocene, along the western slope of the central Basin and on the basement highs These areas are far from the mouth of the Joides trough, where most of the glacial sediment is deposited, and they are also more elevated than the basinal areas, where gravity flow maximum thickness accumulated. Along the western slope of the central Basin and over the basement highs, the signature in the sediments of the action of bottom current reworking and shaping the sea floor can be then clearly recognized. We present the sediment drifts

  15. Alternating Current Influences Anaerobic Electroactive Biofilm Activity.

    Science.gov (United States)

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

    2016-09-06

    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.

  16. Bottom Simulating Reflector and Gas Seepage in Okinawa Trough: Evidence of Gas Hydrate in an Active Back-Arc Basin

    Institute of Scientific and Technical Information of China (English)

    Luan Xiwu; Kelin Wang; Roy Hyndman; Eleanor Willoughby

    2008-01-01

    To look for gas hydrate, 22 multi-channel and 3 single-channel seismic lines on the East China Sea (ECS) shelf slope and at the bottom of the Okinawa Trough were examined. It was found that there was indeed bottom simulating reflector (BSR) occurrence, but it is very rare. Besides several BSRs, a gas seepage was also found. As shown by the data, both the BSR and gas seepage are all related with local geological structures, such as mud diapir, anticline, and fault-controlled graben-like structure. However, similar structural "anomalies" are quite common in the tectonically very active Okinawa Trough region, but very few of them have developed BSR or gas seepage. The article points out that the main reason is probably the low concentration of organic carbon of the sediment in this area. It was speculated that the rare occurrence of gas hydrates in this region is governed by structure-controlled fluid flow. Numerous faults and fractures form a network of high-permeability channels in the sediment and highly fractured igneous basement to allow fluid circulation and ventilation. Fluid flow in this tectonic environment is driven primarily by thermal buoyancy and takes place on a wide range of spatial scales. The fluid flow may play two roles to facilitate hydrate formation:to help gather enough methane into a small area and to modulate the thermal regime.

  17. New Neighbors from 2MASS: Activity and Kinematics at the Bottom of the Main Sequence

    Science.gov (United States)

    Gizis, John E.; Monet, David G.; Reid, I. Neill; Kirkpatrick, J. Davy; Liebert, James; Williams, Rik J.

    2000-08-01

    We have combined 2MASS and POSS II data in a search for nearby ultracool (later than M6.5) dwarfs with Ksmass function that is smooth across the stellar/substellar limit. We show the observed frequency of Hα emission peaks at ~100% for M7 dwarfs and then decreases for cooler dwarfs. In absolute terms, however, as measured by the ratio of Hα to bolometric luminosity, none of the ultracool M dwarfs can be considered very active compared to earlier M dwarfs, and we show that the decrease that begins at spectral type M6 continues to the latest L dwarfs. We find that flaring is common among the coolest M dwarfs and estimate the frequency of flares at 7% or higher. We show that the kinematics of relatively active (EW>6 Å) ultracool M dwarfs are consistent with an ordinary old disk stellar population, while the kinematics of inactive ultracool M dwarfs are more typical of a 0.5 Gyr old population. The early L dwarfs in the sample have kinematics consistent with old ages, suggesting that the hydrogen-burning limit is near spectral types L2-L4. We use the available data on M and L dwarfs to show that chromospheric activity drops with decreasing mass and temperature and that at a given (M8 or later) spectral type, the younger field (brown) dwarfs are less active than many of the older, more massive field stellar dwarfs. Thus, contrary to the well-known stellar age-activity relationship, low activity in field ultracool dwarfs can be an indication of comparative youth and substellar mass.

  18. New Neighbors from 2MASS Activity and Kinematics at the Bottom of the Main Sequence

    CERN Document Server

    Gizis, J E; Reid, I N; Kirkpatrick, J D; Liebert, J; Williams, R J; Gizis, John E.; Monet, David G.; Liebert, James; Williams, Rik J.

    2000-01-01

    We have combined 2MASS and POSS II data in a search for nearby ultracool (later than M6.5) dwarfs with K_s6 Angstroms) ultracool M dwarfs are consistent with an ordinary old disk stellar population, while the kinematics of inactive ultracool M dwarfs are more typical of a 0.5 Gyr old population. The early L dwarfs in the sample have kinematics consistent with old ages, suggesting that the hydrogen burning limit is near spectral types L2-L4. We use the available data on M and L dwarfs to show that chromospheric activity drops with decreasing mass and temperature, and that at a given (M8 or later) spectral type, the younger field (brown) dwarfs are less active than many of the older, more massive field stellar dwarfs. Thus, contrary to the well-known stellar age-activity relationship, low activity in field ultracool dwarfs can be an indication of comparative youth and substellar mass.

  19. Bottom production

    Energy Technology Data Exchange (ETDEWEB)

    Baines, J.; Baranov, S.P.; Bartalini, P.; Bay, A.; Bouhova, E.; Cacciari, M.; Caner, A.; Coadou, Y.; Corti, G.; Damet, J.; Dell-Orso, R.; De Mello Neto, J.R.T.; Domenech, J.L.; Drollinger, V.; Eerola, P.; Ellis, N.; Epp, B.; Frixione, S.; Gadomski, S.; Gavrilenko, I.; Gennai, S.; George, S.; Ghete, V.M.; Guy, L.; Hasegawa, Y.; Iengo, P.; Jacholkowska, A.; Jones, R.; Kharchilava, A.; Kneringer, E.; Koppenburg, P.; Korsmo, H.; Kramer, M.; Labanca, N.; Lehto, M.; Maltoni, F.; Mangano, M.L.; Mele, S.; Nairz, A.M.; Nakada, T.; Nikitin, N.; Nisati, A.; Norrbin, E.; Palla, F.; Rizatdinova, F.; Robins, S.; Rousseau, D.; Sanchis-Lozano, M.A.; Shapiro, M.; Sherwood, P.; Smirnova, L.; Smizanska, M.; Starodumov, A.; Stepanov, N.; Vogt, R.

    2000-03-15

    In the context of the LHC experiments, the physics of bottom flavoured hadrons enters in different contexts. It can be used for QCD tests, it affects the possibilities of B decays studies, and it is an important source of background for several processes of interest. The physics of b production at hadron colliders has a rather long story, dating back to its first observation in the UA1 experiment. Subsequently, b production has been studied at the Tevatron. Besides the transverse momentum spectrum of a single b, it has also become possible, in recent time, to study correlations in the production characteristics of the b and the b. At the LHC new opportunities will be offered by the high statistics and the high energy reach. One expects to be able to study the transverse momentum spectrum at higher transverse momenta, and also to exploit the large statistics to perform more accurate studies of correlations.

  20. Bottom Production

    CERN Document Server

    Nason, P; Schneider, O; Tartarelli, F; Vikas, P; Baines, J T M; Baranov, S P; Bartalini, P; Bay, A; Bouhova-Thacker, E; Cacciari, M; Caner, A; Coadou, Y; Corti, G; Damet, J; Dell'Orso, R; De Mello-Neto, J R T; Domenech, J L; Drollinger, V; Eerola, Paule Anna Mari; Ellis, Nick; Epp, B; Frixione, Stefano; Gadomski, S; Gavrilenko, I; Gennai, Simone; George, S; Ghete, V M; Guy, L P; Hasegawa, Y; Iengo, R; Jacholkowska, A; Jones, R; Kharchilava, A I; Kneringer, E; Koppenburg, P; Korsmo, M; Krämer, M; Labanca, N; Lehto, M H; Maltoni, F; Mangano, Michelangelo L; Mele, S; Nairz, A; Nakada, Tatsuya; Nikitin, N V; Nisati, A; Norrbin, E; Palla, Fabrizio; Rizatdinova, F K; Robins, S A; Rousseau, D; Sanchis-Lozano, M A; Shapiro, M; Sherwood, P; Smirnova, L; Smizanska, M; Starodumov, Andrei; Stepanov, N; Voft, R

    2000-01-01

    We review the prospects for bottom production physics at the LHC. Members of the working group who has contributed to this document are: J. Baines, S.P. Baranov, P. Bartalini, A. Bay, E. Bouhova, M. Cacciari, A. Caner, Y. Coadou, G. Corti, J. Damet, R. Dell'Orso, J.R.T. De Mello Neto, J.L. Domenech, V. Drollinger, P. Eerola, N. Ellis, B. Epp, S. Frixione, S. Gadomski, I. Gavrilenko, S. Gennai, S. George, V.M. Ghete, L. Guy, Y. Hasegawa, P. Iengo, A. Jacholkowska, R. Jones, A. Kharchilava, E. Kneringer, P. Koppenburg, H. Korsmo, M. Kraemer, N. Labanca, M. Lehto, F. Maltoni, M.L. Mangano, S. Mele, A.M. Nairz, T. Nakada, N. Nikitin, A. Nisati, E. Norrbin, F. Palla, F. Rizatdinova, S. Robins, D. Rousseau, M.A. Sanchis-Lozano, M. Shapiro, P. Sherwood, L. Smirnova, M. Smizanska, A. Starodumov, N. Stepanov, R. Vogt

  1. On the Use of Coupled Wind, Wave, and Current Fields in the Simulation of Loads on Bottom-Supported Offshore Wind Turbines during Hurricanes: March 2012 - September 2015

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eungsoo [Univ. of Texas, Austin, TX (United States); Manuel, Lance [Univ. of Texas, Austin, TX (United States); Curcic, Milan [Univ. of Miami, Coral Gables, FL (United States); Chen, Shuyi S. [Univ. of Miami, Coral Gables, FL (United States); Phillips, Caleb [National Renewable Energy Lab. (NREL), Golden, CO (United States); Veers, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-06-01

    In the United States, potential offshore wind plant sites have been identified along the Atlantic seaboard and in the Gulf of Mexico. It is imperative that we define external conditions associated with hurricanes and severe winter storms and consider load cases for which wind turbines may need to be designed. We selected two hurricanes, Ike (2008) and Sandy (2012), and investigated the effect these tropical storms would have on bottom-supported offshore wind turbines that were hypothetically in or close to their path as they made landfall. For realistic turbine loads assessment, it is important that the coupled influences of the changing wind, wave, and current fields are simulated throughout the evolution of the hurricanes. We employed a coupled model--specifically, the University of Miami Coupled Model (UMCM)--that integrates atmospheric, wave, and ocean components to produce needed wind, wave, and current data. The wind data are used to generate appropriate vertical wind profiles and full wind velocity fields including turbulence; the current field over the water column is obtained by interpolated discrete output current data; and short-crested irregular second-order waves are simulated using output directional wave spectra from the coupled model. We studied two monopile-supported offshore wind turbines sited in 20 meters of water in the Gulf of Mexico to estimate loads during Hurricane Ike, and a jacket space-frame platform-supported offshore wind turbine sited in 50 meters of water in the mid-Atlantic region to estimate loads during Hurricane Sandy. In this report we discuss in detail how the simulated hurricane wind, wave, and current output data are used in turbine loads studies. In addition, important characteristics of the external conditions are studied, including the relative importance of swell versus wind seas, aerodynamic versus hydrodynamic forces, current velocity effects, yaw control options for the turbine, hydrodynamic drag versus inertia forces

  2. Plutonium and Uranium Atom Ratios and Activity Levels in Cochiti Lake Bottom Sediments Provided by Pueblo de Cochiti

    Energy Technology Data Exchange (ETDEWEB)

    Gallaher, B.M.; Efurd, D.W.; Rokop, D.J.; Benjamin, T.M.

    1999-05-01

    Historical operations at the Los Alamos National Laboratory have contaminated stream sediments with plutonium and other radionuclides. A small portion of these contaminated sediments has been carried by floods into the Rio Grande drainage system, eventually to be trapped by Cochiti Lake located on Pueblo de Cochiti lands approximately 8 km downstream of the Laboratory. In this study, lake bottom sediment samples provided by the Pueblo de Cochiti were analyzed by thermal ionization mass spectrometry to determine plutonium and uranium activity levels and isotopic atom ratios. This specialized analytical method allows us to take isotopic fingerprints of radionuclides found in the sediment and to determine how much plutonium and uranium came from the Laboratory and how much was deposited by worldwide fallout or is natural. Two distinct types of samples were processed: segments of a continuous vertical core of the entire accumulated sediment sequence and other samples from across the lake bottom at the water/sediment interface. Based on measurement of the {sup 240}Pu/{sup 239}Pu atom ratio, Laboratory-derived plutonium is present in eight of nine samples at the core site. On a depth-weighted basis, approximately one-half of the {sup 239}Pu and {sup 240}Pu came from early operations at the Laboratory; the remaining plutonium came from fallout dispersed by above-ground nuclear tests. In contrast to the core site, the samples from the other locations showed little or no evidence of Laboratory-derived plutonium, with more than 90 percent of the plutonium attributable to fallout. The overall amount of plutonium in all the samples is of the same magnitude as other reservoirs in the region. The net increase in plutonium over upstream reservoirs unaffected by Laboratory activities is a maximum of 0.014 pCi/g or 3.5 times. All of the samples reflect natural uranium compositions. Laboratory-derived uranium is not identifiable, presumably because the sediment contains abundant

  3. On Active Current Selection for Lagrangian Profilers

    Directory of Open Access Journals (Sweden)

    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.

  4. The Evolution of the Electric Current during the Formation and Eruption of Active-region Filaments

    Science.gov (United States)

    Wang, Jincheng; Yan, Xiaoli; Qu, Zhongquan; Xue, Zhike; Xiang, Yongyuan; Li, Hao

    2016-02-01

    We present a comprehensive study of the electric current related to the formation and eruption of active region filaments in NOAA AR 11884. The vertical current on the solar surface was investigated by using vector magnetograms (VMs) observed by HMI on board the Solar Dynamics Observatory. To obtain the electric current along the filament's axis, we reconstructed the magnetic fields above the photosphere by using nonlinear force-free field extrapolation based on photospheric VMs. Spatio-temporal evolutions of the vertical current on the photospheric surface and the horizontal current along the filament's axis were studied during the long-term evolution and eruption-related period, respectively. The results show that the vertical currents of the entire active region behaved with a decreasing trend and the magnetic fields also kept decreasing during the long-term evolution. For the eruption-related evolution, the mean transverse field strengths decreased before two eruptions and increased sharply after two eruptions in the vicinity of the polarity inversion lines underneath the filament. The related vertical current showed different behaviors in two of the eruptions. On the other hand, a very interesting feature was found: opposite horizontal currents with respect to the current of the filament's axis appeared and increased under the filament before the eruptions and disappeared after the eruptions. We suggest that these opposite currents were carried by the new flux emerging from the photosphere bottom and might be the trigger mechanism for these filament eruptions.

  5. Estimation of Emissions from Sugarcane Field Burning in Thailand Using Bottom-Up Country-Specific Activity Data

    Directory of Open Access Journals (Sweden)

    Wilaiwan Sornpoon

    2014-09-01

    Full Text Available Open burning in sugarcane fields is recognized as a major source of air pollution. However, the assessment of its emission intensity in many regions of the world still lacks information, especially regarding country-specific activity data including biomass fuel load and combustion factor. A site survey was conducted covering 13 sugarcane plantations subject to different farm management practices and climatic conditions. The results showed that pre-harvest and post-harvest burnings are the two main practices followed in Thailand. In 2012, the total production of sugarcane biomass fuel, i.e., dead, dry and fresh leaves, amounted to 10.15 million tonnes, which is equivalent to a fuel density of 0.79 kg∙m−2. The average combustion factor for the pre-harvest and post-harvest burning systems was determined to be 0.64 and 0.83, respectively. Emissions from sugarcane field burning were estimated using the bottom-up country-specific values from the site survey of this study and the results compared with those obtained using default values from the 2006 IPCC Guidelines. The comparison showed that the use of default values lead to underestimating the overall emissions by up to 30% as emissions from post-harvest burning are not accounted for, but it is the second most common practice followed in Thailand.

  6. Overview of Current Activities in Combustion Instability

    Science.gov (United States)

    2015-10-02

    9/23/2015 14. ABSTRACT Briefing Charts/Viewgraph 15. SUBJECT TERMS N/A 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18...CSTD Approved for public release; distribution unlimited 14 ALREST phase II Multifidelity Tools and Methodologies Phase I VISP SPACE Current gen  HF ...Current gen  HF ,  productional Next gen  HF F i d e l i t y High fidelity Cost  ALREST phase II Experiments  Approved for public release

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

    DEFF Research Database (Denmark)

    Dolmer, Per

    2000-01-01

    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 filtration activity. During days 1 and 2 the near-bed current velocities were low (1.2-2.1 cm s(-1)), and the near-bed phytoplankton biomass was at the same time lower than near the water surface. Between 44 and 69% of the mussels had closed shells and accumulated only small amounts of Chl-a in the body...... 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...

  8. Transient sodium current at subthreshold voltages: activation by EPSP waveforms.

    Science.gov (United States)

    Carter, Brett C; Giessel, Andrew J; Sabatini, Bernardo L; Bean, Bruce P

    2012-09-20

    Tetrodotoxin (TTX)-sensitive sodium channels carry large transient currents during action potentials and also "persistent" sodium current, a noninactivating TTX-sensitive current present at subthreshold voltages. We examined gating of subthreshold sodium current in dissociated cerebellar Purkinje neurons and hippocampal CA1 neurons, studied at 37°C with near-physiological ionic conditions. Unexpectedly, in both cell types small voltage steps at subthreshold voltages activated a substantial component of transient sodium current as well as persistent current. Subthreshold EPSP-like waveforms also activated a large component of transient sodium current, but IPSP-like waveforms engaged primarily persistent sodium current with only a small additional transient component. Activation of transient as well as persistent sodium current at subthreshold voltages produces amplification of EPSPs that is sensitive to the rate of depolarization and can help account for the dependence of spike threshold on depolarization rate, as previously observed in vivo.

  9. Cardiac allograft immune activation: current perspectives

    Directory of Open Access Journals (Sweden)

    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

  10. DISTRIBUTION OF ELECTRIC CURRENTS IN SOLAR ACTIVE REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    Török, T.; Titov, V. S.; Mikić, Z. [Predictive Science, Inc., 9990 Mesa Rim Road, Suite 170, San Diego, CA 92121 (United States); Leake, J. E. [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Archontis, V. [School of Mathematics and Statistics, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS (United Kingdom); Linton, M. G. [U.S. Naval Research Lab, 4555 Overlook Avenue, SW Washington, DC 20375 (United States); Dalmasse, K.; Aulanier, G. [LESIA, Observatoire de Paris, CNRS, UPMC, Univ. Paris Diderot, 5 place Jules Janssen, F-92190 Meudon (France); Kliem, B. [Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam (Germany)

    2014-02-10

    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.

  11. Integrated Monitoring of the Soya Warm Current Using HF Ocean Radars, Satellite Altimeters, Coastal Tide Gauges, and a Bottom-Mounted ADCP

    Science.gov (United States)

    Ebuchi, N.; Fukamachi, Y.; Ohshima, K. I.; Wakatsuchi, M.

    2007-12-01

    The Soya Warm Current (SWC) is a coastal boundary current, which flows along the coast of Hokkaido in the Sea of Okhotsk. The SWC flows into the Sea of Okhotsk from the Sea of Japan through the Soya/La Perouse Strait, which is located between Hokkaido, Japan, and Sakhalin, Russia. It supplies warm, saline water in the Sea of Japan to the Sea of Okhotsk and largely affects the ocean circulation and water mass formation in the Sea of Okhotsk, and local climate, environment and fishery in the region. However, the SWC has never been continuously monitored due to the difficulties involved in field observations related to, for example, severe weather conditions in the winter, political issues at the border strait, and conflicts with fishing activities in the strait. Detailed features of the SWC and its variations have not yet been clarified. In order to monitor variations in the SWC, three HF ocean radar stations were installed around the strait. The radar covers a range of approximately 70 km from the coast. It is shown that the HF radars clearly capture seasonal and subinertial variations of the SWC. The velocity of the SWC reaches its maximum, approximately 1 m/s, in summer, and weakens in winter. The velocity core is located 20 to 30 km from the coast, and its width is approximately 50 km. The surface transport by the Soya Warm Current shows a significant correlation with the sea level difference along the strait, as derived from coastal tide gauge records. The cross-current sea level difference, which is estimated from the sea level anomalies observed by the Jason-1 altimeter and a coastal tide gauge, also exhibits variation in concert with the surface transport and along-current sea level difference.

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

    Data.gov (United States)

    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...

  13. Bottom friction optimization for a better barotropic tide modelling

    Science.gov (United States)

    Boutet, Martial; Lathuilière, Cyril; Son Hoang, Hong; Baraille, Rémy

    2015-04-01

    At a regional scale, barotropic tides are the dominant source of variability of currents and water heights. A precise representation of these processes is essential because of their great impacts on human activities (submersion risks, marine renewable energies, ...). Identified sources of error for tide modelling at a regional scale are the followings: bathymetry, boundary forcing and dissipation due to bottom friction. Nevertheless, bathymetric databases are nowadays known with a good accuracy, especially over shelves, and global tide models performances are better than ever. The most promising improvement is thus the bottom friction representation. The method used to estimate bottom friction is the simultaneous perturbation stochastic approximation (SPSA) which consists in the approximation of the gradient based on a fixed number of cost function measurements, regardless of the dimension of the vector to be estimated. Indeed, each cost function measurement is obtained by randomly perturbing every component of the parameter vector. An important feature of SPSA is its relative ease of implementation. In particular, the method does not require the development of tangent linear and adjoint version of the circulation model. Experiments are carried out to estimate bottom friction with the HYbrid Coordinate Ocean Model (HYCOM) in barotropic mode (one isopycnal layer). The study area is the Northeastern Atlantic margin which is characterized by strong currents and an intense dissipation. Bottom friction is parameterized with a quadratic term and friction coefficient is computed with the water height and the bottom roughness. The latter parameter is the one to be estimated. Assimilated data are the available tide gauge observations. First, the bottom roughness is estimated taking into account bottom sediment natures and bathymetric ranges. Then, it is estimated with geographical degrees of freedom. Finally, the impact of the estimation of a mixed quadratic/linear friction

  14. Both barium and calcium activate neuronal potassium currents

    Energy Technology Data Exchange (ETDEWEB)

    Ribera, A.B.; Spitzer, N.C.

    1987-09-01

    Amphibian spinal neurons in culture possess both rapidly inactivating and sustained calcium-dependent potassium current components, similar to those described for other cells. Divalent cation-dependent whole-cell outward currents were isolated by subtracting the voltage-dependent potassium currents recorded from Xenopus laevis neurons in the presence of impermeant cadmium from the currents produced without cadmium but in the presence of permeant divalent cations. These concentrations of permeant ions were low enough to avoid contamination by macroscopic inward currents through calcium channels. Calcium-dependent potassium currents were reduced by 1 ..mu..M tetraethylammonium. These currents can also be activated by barium or strontium. Barium as well as calcium activated outward currents in young neurons (6-8 hr) and in relatively mature neurons (19-26 hr in vitro). However, barium influx appeared to suppress the sustained voltage-dependent potassium current in most cells. Barium also activated at least one class of potassium channels observed in excised membrane patches, whole blocking others. The blocking action may have masked and hindered detection of the stimulatory action of barium in other systems.

  15. Cathodic protection for the bottoms of above ground storage tanks

    Energy Technology Data Exchange (ETDEWEB)

    Mohr, John P. [Tyco Adhesives, Norwood, MA (United States)

    2004-07-01

    Impressed Current Cathodic Protection has been used for many years to protect the external bottoms of above ground storage tanks. The use of a vertical deep ground bed often treated several bare steel tank bottoms by broadcasting current over a wide area. Environmental concerns and, in some countries, government regulations, have introduced the use of dielectric secondary containment liners. The dielectric liner does not allow the protective cathodic protection current to pass and causes corrosion to continue on the newly placed tank bottom. In existing tank bottoms where inadequate protection has been provided, leaks can develop. In one method of remediation, an old bottom is covered with sand and a double bottom is welded above the leaking bottom. The new bottom is welded very close to the old bottom, thus shielding the traditional cathodic protection from protecting the new bottom. These double bottoms often employ the use of dielectric liner as well. Both the liner and the double bottom often minimize the distance from the external tank bottom. The minimized space between the liner, or double bottom, and the bottom to be protected places a challenge in providing current distribution in cathodic protection systems. This study examines the practical concerns for application of impressed current cathodic protection and the types of anode materials used in these specific applications. One unique approach for an economical treatment using a conductive polymer cathodic protection method is presented. (author)

  16. Suppression of spontaneous epileptiform activity with applied currents.

    Science.gov (United States)

    Nakagawa, M; Durand, D

    1991-12-20

    It has been well established that both applied and endogenous electric fields can modulate neuronal activity in various preparations. In this paper, we present the effects of applied currents on spontaneous epileptiform activity in the CA1 region of the rat hippocampus. A computer-controlled system was designed to detect the spontaneous abnormal activity and then apply current pulses of programmable amplitude with monopolar electrodes in the stratum pyramidale. The epileptiform activity was generated by subperfusion of the neural tissue with an elevated potassium artificial cerebrospinal fluid (CSF) solution. Extracellular recordings showed that the interictal bursts could be fully suppressed in 90% of the slices by subthreshold currents with an average amplitude of 12.5 microA. Intracellular recordings showed that the anodic currents generated hyperpolarization of the somatic membrane thereby suppressing neuronal firing. This inhibitory effect of applied current pulses is important for the understanding of electric field effects on abnormal neuronal activity and could be an effective means of preventing the spread of epileptiform activity.

  17. Active current control in wind power plants during grid faults

    DEFF Research Database (Denmark)

    Martinez, Jorge; Kjær, Phillip C.; Rodriguez, Pedro;

    2010-01-01

    , wind turbines usually have solutions that enable the turbines to control the generation of reactive power during faults. This paper addresses the importance of using an optimal injection of active current during faults in order to fulfil these grid codes. This is of relevant importance for severe......Modern wind power plants are required and designed to ride through faults in electrical networks, subject to fault clearing. Wind turbine fault current contribution is required from most countries with a high amount of wind power penetration. In order to comply with such grid code requirements...... faults, causing low voltages at the point of common coupling. As a consequence, a new wind turbine current controller for operation during faults is proposed. It is shown that to achieve the maximum transfer of reactive current at the point of common coupling, a strategy for optimal setting of the active...

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

    Science.gov (United States)

    Newman, Cynthia M.

    2002-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  20. Current concepts of active vasodilation in human skin

    Science.gov (United States)

    Wong, Brett J.; Hollowed, Casey G.

    2017-01-01

    ABSTRACT In humans, an increase in internal core temperature elicits large increases in skin blood flow and sweating. The increase in skin blood flow serves to transfer heat via convection from the body core to the skin surface while sweating results in evaporative cooling of the skin. Cutaneous vasodilation and sudomotor activity are controlled by a sympathetic cholinergic active vasodilator system that is hypothesized to operate through a co-transmission mechanism. To date, mechanisms of cutaneous active vasodilation remain equivocal despite many years of research by several productive laboratory groups. The purpose of this review is to highlight recent advancements in the field of cutaneous active vasodilation framed in the context of some of the historical findings that laid the groundwork for our current understanding of cutaneous active vasodilation.

  1. Comparison of excitatory currents activated by different transmitters on crustacean muscle. II. Glutamate-activated currents and comparison with acetylcholine currents present on the same muscle.

    Science.gov (United States)

    Lingle, C; Auerbach, A

    1983-04-01

    The properties of glutamate-activated excitatory currents on the gm6 muscle from the foregut of the spiny lobsters Panulirus argus and interruptus and the crab Cancer borealis were examined using either noise analysis, analysis of synaptic current decays, or slow iontophoretic currents. The properties of acetylcholine currents activated in nonjunctional regions of the gm6 muscle were also examined. At 12 degrees C and -80 mV, the predominant time constant of power spectra from glutamate-activated current noise was approximately 7 ms and the elementary conductance was approximately 34 pS. At 12 degrees C and -80 mV, the predominant time constant of acetylcholine-activated channels was approximately 11 ms with a conductance of approximately 12 pS. Focally recorded glutamatergic extracellular synaptic currents on the gm6 muscle decayed with time constants of approximately 7-8 ms at 12 degrees C and -80 mV. The decay time constant was prolonged e-fold about every 225-mV hyperpolarization in membrane potential. The Q10 of the time constant of the synaptic current decay was approximately 2.6. The voltage dependence of the steady-state conductance increase activated by iontophoretic application of glutamate has the opposite direction of the steady-state conductance activated by cholinergic agonists when compared on the gm6 muscles. The glutamate-activated conductance increase is diminished with hyperpolarization. The properties of the marine crustacean glutamate channels are discussed in relation to glutamate channels in other organisms and to the acetylcholine channels found on the gm6 muscle and the gm1 muscle of the decapod foregut (Lingle and Auerbach, 1983).

  2. Identifying the computational requirements of an integrated top-down-bottom-up model for overt visual attention within an active vision system.

    Directory of Open Access Journals (Sweden)

    Sebastian McBride

    Full Text Available Computational visual attention systems have been constructed in order for robots and other devices to detect and locate regions of interest in their visual world. Such systems often attempt to take account of what is known of the human visual system and employ concepts, such as 'active vision', to gain various perceived advantages. However, despite the potential for gaining insights from such experiments, the computational requirements for visual attention processing are often not clearly presented from a biological perspective. This was the primary objective of this study, attained through two specific phases of investigation: 1 conceptual modeling of a top-down-bottom-up framework through critical analysis of the psychophysical and neurophysiological literature, 2 implementation and validation of the model into robotic hardware (as a representative of an active vision system. Seven computational requirements were identified: 1 transformation of retinotopic to egocentric mappings, 2 spatial memory for the purposes of medium-term inhibition of return, 3 synchronization of 'where' and 'what' information from the two visual streams, 4 convergence of top-down and bottom-up information to a centralized point of information processing, 5 a threshold function to elicit saccade action, 6 a function to represent task relevance as a ratio of excitation and inhibition, and 7 derivation of excitation and inhibition values from object-associated feature classes. The model provides further insight into the nature of data representation and transfer between brain regions associated with the vertebrate 'active' visual attention system. In particular, the model lends strong support to the functional role of the lateral intraparietal region of the brain as a primary area of information consolidation that directs putative action through the use of a 'priority map'.

  3. Identifying the computational requirements of an integrated top-down-bottom-up model for overt visual attention within an active vision system.

    Science.gov (United States)

    McBride, Sebastian; Huelse, Martin; Lee, Mark

    2013-01-01

    Computational visual attention systems have been constructed in order for robots and other devices to detect and locate regions of interest in their visual world. Such systems often attempt to take account of what is known of the human visual system and employ concepts, such as 'active vision', to gain various perceived advantages. However, despite the potential for gaining insights from such experiments, the computational requirements for visual attention processing are often not clearly presented from a biological perspective. This was the primary objective of this study, attained through two specific phases of investigation: 1) conceptual modeling of a top-down-bottom-up framework through critical analysis of the psychophysical and neurophysiological literature, 2) implementation and validation of the model into robotic hardware (as a representative of an active vision system). Seven computational requirements were identified: 1) transformation of retinotopic to egocentric mappings, 2) spatial memory for the purposes of medium-term inhibition of return, 3) synchronization of 'where' and 'what' information from the two visual streams, 4) convergence of top-down and bottom-up information to a centralized point of information processing, 5) a threshold function to elicit saccade action, 6) a function to represent task relevance as a ratio of excitation and inhibition, and 7) derivation of excitation and inhibition values from object-associated feature classes. The model provides further insight into the nature of data representation and transfer between brain regions associated with the vertebrate 'active' visual attention system. In particular, the model lends strong support to the functional role of the lateral intraparietal region of the brain as a primary area of information consolidation that directs putative action through the use of a 'priority map'.

  4. The spatial extent of the Deep Western Boundary Current into the Bounty Trough: new evidence from parasound sub-bottom profiling

    Science.gov (United States)

    Horn, Michael; Uenzelmann-Neben, Gabriele

    2016-06-01

    Deep currents such as the Pacific Deep Western Boundary Current (DWBC) are strengthened periodically in Milankovitch cycles. We studied periodic fluctuations in seismic reflection pattern and reflection amplitude in order to detect cycles in the sedimentary layers of Bounty Trough and bounty fan, east of New Zealand. There, the occurrence of the obliquity frequency is caused only by the DWBC. Therefore, it provides direct evidence for the spatial extent of the DWBC. We can confirm the extent of the DWBC west of the outer sill, previously only inferred via erosional features at the outer sill. Further, our data allow an estimation of the extent of the DWBC into the Bounty Trough, limiting the DWBC presence to east of 178.15°E. Using the presented method a larger dataset will allow a chronological and areal mapping of sedimentation processes and hence provide information on glacial/interglacial cycles.

  5. Increasing sediment accumulation rates in La Fonera (Palamós) submarine canyon axis and their relationship with bottom trawling activities

    Science.gov (United States)

    Puig, P.; Martín, J.; Masqué, P.; Palanques, A.

    2015-10-01

    Previous studies conducted in La Fonera (Palamós) submarine canyon (NW Mediterranean) found that trawling activities along the canyon flanks cause resuspension and transport of sediments toward the canyon axis. 210Pb chronology supported by 137Cs dating applied to a sediment core collected at 1750 m in 2002 suggested a doubling of the sediment accumulation rate since the 1970s, coincident with the rapid industrialization of the local trawling fleet. The same canyon area has been revisited a decade later, and new data are consistent with a sedimentary regime shift during the 1970s and also suggest that the accumulation rate during the last decade could be greater than expected, approaching ~2.4 cm yr-1 (compared to ~0.25 cm yr-1 pre-1970s). These results support the hypothesis that commercial bottom trawling can substantially affect sediment dynamics and budgets on continental margins, eventually initiating the formation of anthropogenic depocenters in submarine canyon environments.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Improving Industrial Energy Quality by an Active Current Filter

    Directory of Open Access Journals (Sweden)

    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.

  8. Wave refraction in the presence of currents and variations of the marine bottom; Refraccion del oleaje en presencia de corrientes y variaciones del fondo marino

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Hernandez, G.; Silva Casarin, R. [Instituto de Ingenieria, UNAM, Mexico, D.F. (Mexico)

    2001-03-01

    A method for solving the wave refraction phenomena through a computational model, which solves the wave height and propagation angle from deep to shallow water including wave breaking, is shown. The program considers the shoaling and refraction effects, wave-currents interaction and the non-linearity assumption. The numerical model is based in two principles: the irrotationality of the wave number, which is reduced to the Snell's law for planar bathymetry, and the conservation of wave action, which is reduced to the energy conservation concept when no current interaction occurs. The two-step Lax-Wendroff differential method was used to calculate and solve the entire computational grid. Three different examples that help represent the whole method are shown; the first case is based on an idealized plane and horizontal bathymetry, the second case is the experimental model developed by Berkhoff (1982), and finally the Noda (1974) example is reproduced. [Spanish] Se presenta un modelo numerico para estudiar el fenomeno de la refraccion del oleaje inducida por la presencia de corrientes, cambios batimetricos, rotura y disipacion. El modelo calcula sobre una malla computacional la altura y la direccion local del oleaje. El programa considera los efectos de asomeramiento, refraccion, interaccion oleaje-corriente y su no-linearidad. Los principios que utiliza el modelo son dos; la irrotacionalidad del numero de onda, que para batimetria plana se reduce a la ley de Snell y el principio de conservacion de la accion de ondas, que se simplifica al concepto de la conservacion de la energia cuando no existen corrientes. El metodo diferencial que se utiliza para el calculo e interpolacion de datos sobre la malla de discretizacion es Lax-Wendroff en dos pasos. Se muestran tres casos que ayudan a representar el metodo en su totalidad: el primero se modela con base en una batimetria idealizada, plana y horizontal, el segundo se simula a partir del medolo experimental de

  9. Improved Active Harmonic Current Elimination Based on Voltage Detection.

    Directory of Open Access Journals (Sweden)

    Tianyuan Tan

    Full Text Available With the increasing penetration of power electronic equipment in modern residential distribution systems, harmonics mitigation through the distributed generation (DG interfacing converters has received significant attention. Among recently proposed methods, the so-called active resonance damper (ARD and harmonic voltage compensator (HVC based on voltage detection can effectively reduce the harmonic distortions in selected areas of distribution systems. However, it is found out that when traditional ARD algorithm is used to eliminate harmonic current injected by non-linear loads, its performance is constrained by stability problems and can at most eliminate half of the load harmonic currents. Thus, inspired by the duality between ARD and HVC, this paper presents a novel improved resistive active power filter (R-APF algorithm based on integral-decoupling control. The design guideline for its parameters is then investigated through carefully analyzing the closed-loop poles' trajectory. Computer studies demonstrate that the proposed algorithm can effectively mitigate the load harmonic currents and its performance is much better than traditional ARD based on proportional control.

  10. Cardiac activation mapping using ultrasound current source density imaging (UCSDI).

    Science.gov (United States)

    Olafsson, Ragnar; Witte, Russell S; Jia, Congxian; Huang, Sheng-Wen; Kim, Kang; O'Donnell, Matthew

    2009-03-01

    We describe the first mapping of biological current in a live heart using ultrasound current source density imaging (UCSDI). Ablation procedures that treat severe heart arrhythmias require detailed maps of the cardiac activation wave. The conventional procedure is time-consuming and limited by its poor spatial resolution (5-10 mm). UCSDI can potentially improve on existing mapping procedures. It is based on a pressure-induced change in resistivity known as the acousto-electric (AE) effect, which is spatially confined to the ultrasound focus. Data from 2 experiments are presented. A 540 kHz ultrasonic transducer (f/# = 1, focal length = 90 mm, pulse repetition frequency = 1600 Hz) was scanned over an isolated rabbit heart perfused with an excitation-contraction decoupler to reduce motion significantly while retaining electric function. Tungsten electrodes inserted in the left ventricle recorded simultaneously the AE signal and the low-frequency electrocardiogram (ECG). UCSDI displayed spatial and temporal patterns consistent with the spreading activation wave. The propagation velocity estimated from UCSDI was 0.25 +/- 0.05 mm/ms, comparable to the values obtained with the ECG signals. The maximum AE signal-to-noise ratio after filtering was 18 dB, with an equivalent detection threshold of 0.1 mA/ cm(2). This study demonstrates that UCSDI is a potentially powerful technique for mapping current flow and biopotentials in the heart.

  11. Adaptive Current Control Method for Hybrid Active Power Filter

    Science.gov (United States)

    Chau, Minh Thuyen

    2016-09-01

    This paper proposes an adaptive current control method for Hybrid Active Power Filter (HAPF). It consists of a fuzzy-neural controller, identification and prediction model and cost function. The fuzzy-neural controller parameters are adjusted according to the cost function minimum criteria. For this reason, the proposed control method has a capability on-line control clings to variation of the load harmonic currents. Compared to the single fuzzy logic control method, the proposed control method shows the advantages of better dynamic response, compensation error in steady-state is smaller, able to online control is better and harmonics cancelling is more effective. Simulation and experimental results have demonstrated the effectiveness of the proposed control method.

  12. Mapping of sea bottom topography

    Science.gov (United States)

    Calkoen, C. J.; Wensink, G. J.; Hesselmans, G. H. F. M.

    1992-01-01

    Under suitable conditions the bottom topography of shallow seas is visible in remote sensing radar imagery. Two experiments were performed to establish which remote sensing technique or combination yields optimal imaging of bottom topography and which hydro-meteorological conditions are favorable. A further goal is to gain experience with these techniques. Two experiments were performed over an area in the North Sea near the measuring platform Meetpost Noordwijk (MPN). The bottom topography in the test area is dominated by sand waves. The crests of the sand waves are perpendicular to the coast line and the dominating (tidal-)current direction. A 4x4 sq km wide section of the test area was studied in more detail. The first experiment was undertaken on 16 Aug. 1989. During the experiment the following remote sensing instruments were used: Landsat-Thematic Mapper, and NASA/JPL Airborne Imaging Radar (AIR). The hydro-meteorological conditions; current, wind, wave, and air and water temperature were monitored by MPN, a ship of Rijkswaterstaat (the OCTANS), and a pitch-and-roll WAVEC-buoy. The second experiment took place on 12 July 1992. During this experiment data were collected with the NASA/JPL polarimetric synthetic aperture radar (SAR), and a five-band helicopter-borne scatterometer. Again the hydro-meteorological conditions were monitored at MPN and the OCTANS. Furthermore, interferometric radar data were collected.

  13. Spring Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Spring Bottom Trawl Survey was initiated in 1968 and covered an area from Cape Hatteras, NC, to Nova Scotia, Canada, at depths >27m....

  14. Winter Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Winter Bottom Trawl Survey was initiated in 1992 and covered offshore areas from the Mid-Atlantic to Georges Bank. Inshore strata were covered...

  15. Fall Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Fall Bottom Trawl Survey was initiated in 1963 and covered an area from Hudson Canyon, NY to Nova Scotia, Canada. Throughout the years,...

  16. Data Mining Activities for Bone Discipline - Current Status

    Science.gov (United States)

    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.

  17. The effect of Peltier heat during current activated densification

    Science.gov (United States)

    Becker, A.; Angst, S.; Schmitz, A.; Engenhorst, M.; Stoetzel, J.; Gautam, D.; Wiggers, H.; Wolf, D. E.; Schierning, G.; Schmechel, R.

    2012-07-01

    It is shown that current-activated pressure-assisted densification (CAPAD) is sensitive to the Peltier effect. Under CAPAD, the Peltier effect leads to a significant redistribution of heat within the sample during the densification. The densification of highly p-doped silicon nanoparticles during CAPAD and the properties of the obtained samples are investigated experimentally and by computer simulation. Both, simulation and experiments, indicate clearly a higher temperature on the cathode side and a decreasing temperature from the center to the outer shell. Furthermore, computer simulations provide additional insights into the temperature profile which explain the anisotropic properties of the measured sample.

  18. Aspects of calcium-activated chloride currents: a neuronal perspective.

    Science.gov (United States)

    Scott, R H; Sutton, K G; Griffin, A; Stapleton, S R; Currie, K P

    1995-06-01

    Ca(2+)-activated Cl- channels are expressed in a variety of cell types, including central and peripheral neurones. These channels are activated by a rise in intracellular Ca2+ close to the cell membrane. This can be evoked by cellular events such as Ca2+ entry through voltage- and ligandgated channels or release of Ca2+ from intracellular stores. Additionally, these Ca(2+)-activated Cl currents (ICl(Ca)) can be activated by raising intracellular Ca2+ through artificial experimental procedures such as intracellular photorelease of Ca2+ from "caged" photolabile compounds (e.g. DM-nitrophen) or by treating cells with Ca2+ ionophores. The potential changes that result from activation of Ca(2+)-activated Cl- channels are dependent on resting membrane potential and the equilibrium potential for Cl-. Ca2+ entry during a single action potential is sufficient to produce substantial after potentials, suggesting that the activity of these Cl- channels can have profound effects on cell excitability. The whole cell ICl(Ca) can be identified by sensitivity to increased Ca2+ buffering capacity of the cell, anion substitution studies and reversal potential measurements, as well as by the actions of Cl- channel blockers. In cultured sensory neurones, there is evidence that the ICl(Ca) deactivates as Ca2+ is buffered or removed from the intracellular environment. To date, there is no evidence in mammalian neurones to suggest these Ca(2+)-sensitive Cl- channels undergo a process of inactivation. Therefore, ICl(Ca) can be used as a physiological index of intracellular Ca2+ close to the cell membrane. The ICl(Ca) has been shown to be activated or prolonged as a result of metabolic stress, as well as by drugs that disturb intracellular Ca2+ homeostatic mechanisms or release Ca2+ from intracellular stores. In addition to sensitivity to classic Cl- channel blockers such as niflumic acid, derivatives of stilbene (4,4'diisothiocyanostilbene-2,2'-disulphonic acid, 4-acetamido-4

  19. Charmed Bottom Baryon Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Zachary S; Detmold, William; Meinel, Stefan; Orginos, Kostas

    2014-11-01

    The spectrum of doubly and triply heavy baryons remains experimentally unexplored to a large extent. Although the detection of such heavy particle states may lie beyond the reach of exper- iments for some time, it is interesting compute this spectrum from QCD and compare results between lattice calculations and continuum theoretical models. Several lattice calculations ex- ist for both doubly and triply charmed as well as doubly and triply bottom baryons. Here, we present preliminary results from the first lattice calculation of doubly and triply heavy baryons including both charm and bottom quarks. We use domain wall fermions for 2+1 flavors (up down and strange) of sea and valence quarks, a relativistic heavy quark action for the charm quarks, and non-relativistic QCD for the heavier bottom quarks. We present preliminary results for the ground state spectrum.

  20. Current Reactor Physics Benchmark Activities at the Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    John D. Bess; Margaret A. Marshall; Mackenzie L. Gorham; Joseph Christensen; James C. Turnbull; Kim Clark

    2011-11-01

    The International Reactor Physics Experiment Evaluation Project (IRPhEP) [1] and the International Criticality Safety Benchmark Evaluation Project (ICSBEP) [2] were established to preserve integral reactor physics and criticality experiment data for present and future research. These valuable assets provide the basis for recording, developing, and validating our integral nuclear data, and experimental and computational methods. These projects are managed through the Idaho National Laboratory (INL) and the Organisation for Economic Co-operation and Development Nuclear Energy Agency (OECD-NEA). Staff and students at the Department of Energy - Idaho (DOE-ID) and INL are engaged in the development of benchmarks to support ongoing research activities. These benchmarks include reactors or assemblies that support Next Generation Nuclear Plant (NGNP) research, space nuclear Fission Surface Power System (FSPS) design validation, and currently operational facilities in Southeastern Idaho.

  1. Bottom pressure, vertical acoustic round-trip travel time, and near-bottom currents data collected by Current-and-Pressure-recording Inverted Echo Sounders (CPIES), as part of the Kuroshio Extension System Study (KESS), from 26 April 2004 to 25 June 2006 in the Kuroshio Extension east of Japan (NODC Accession 0073269)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains Current and Pressure recording Inverted Echo Sounder (CPIES) measurements collected during the Kuroshio Extension System Study (KESS) under...

  2. DOE ORDER 435.1, IMPLEMENTATION AND COMPLIANCE DECLARATION AT THE SAVANNAH RIVER SITE AND ACROSS THE DOE COMPLEX IN CONTRAST TO CURRENT PUSHBACK EFFORTS FROM THE ''TOP-TO-BOTTOM'' REVIEW

    Energy Technology Data Exchange (ETDEWEB)

    GOLDSTON, WELFORD T.; SMITH, WINCHESTER IV

    2003-02-27

    DOE issued Order 435.1, ''Radioactive Waste Management,'' on July 9, 1999 for immediate implementation. The requirements for Low Level Mixed, Transuranic, and High Level Waste have been completely rewritten. The entire DOE complex has been struggling with how to implement these new requirements within the one year required timeframe. This paper will chronicle the implementation strategy and actual results of the work to carry out that strategy at the Savannah River Site. DOE-SR and the site contractors worked closely together to implement each of the new requirements across the SRS, crossing many barriers and providing innovative solutions to the many problems that surfaced throughout the year. The results are that SRS declared compliance with all of the requirements of the Order within the prescribed timeframe. The challenge included all waste types in SRS facilities and programs that handle LLW, MLLW, TRU, and HLW. This paper will describe the implementation details for development of Radioactive Waste Management Basis for each facility, Identification of Wastes with No Path to Disposal, Waste Incidental to Reprocessing Determinations, Low Level Waste 90-Day Staging and One Year Limits for Storage Programs, to name a few of the requirements that were addressed by the SRS 435.1 Implementation Team. This paper will trace the implementation, problems (both technical and administrative), and the current pushback efforts associated with the DOE ''Top-to-Bottom'' review.

  3. A Search for Coronal Emission at the Bottom of the Main-Sequence: Stars and Brown Dwarf Candidates with Spectral Types Later than M7 and the Rotation-Activity Relation

    Science.gov (United States)

    Stringfellow, Guy

    2004-01-01

    This program intended to test whether the lowest mass stars at the bottom end of the main sequence and the lower mass brown dwarfs have coronae. If they have coronae, what are the coronal characteristics and what drives them? In the classical dynamo picture, the closed magnetic loop structure is generated near the boundary of the convective envelope and the radiative core. Stars with mass below 0.30 Msun however are fully convective, and the nature of the dynamo responsible for the generation of the coronae in this regime is poorly understood. Previous results from the ROSAT mission (e.g., Fleming et al. 1993, 1995; Schmitt et al. 1995) had confirmed three very important characteristics of M-star coronae: (1) a very high percentage of all M dwarfs have coronae (of order 85% in the local 7 pc sample), (2) those M dwarfs showing high chromospheric activity, such as having the Balmer series in emission or large/numerous optical flaring, indeed exhibit the highest coronal activity, and (3) that the maximum saturation boundary in X-ray luminosity, which amounts to 0.0001-0.001 for Lx/Lbol for the dMe stars, extends down to the current detection limit, through spectral types M7. It was likely that the incompleteness noted for result (1) above was simply a detection limit problem; for more distant sources, the X-ray fainter dM stars will drop below detection thresholds before the more X-ray luminous dMe stars. The latest stars for which direct detection of the corona had been successful were of spectral type dM7 (e.g., VB8, LHS 3003). This program proposed to obtain ROSAT HRI observations for a large number of the coolest known (at that time) stars at the bottom of the main-sequence, which had spectral types of M9 or later. Three stars were approved for observations with ROSAT-HRI totaling 180 ksec. The goal was to obtain X-ray detections or low upper limits for the three approved stars.

  4. Both barium and calcium activate neuronal potassium currents.

    OpenAIRE

    Ribera, A B; Spitzer, N C

    1987-01-01

    Amphibian spinal neurons in culture possess both rapidly inactivating and sustained calcium-dependent potassium current components, similar to those described for other cells. Divalent cation-dependent whole-cell outward currents were isolated by subtracting the voltage-dependent potassium currents recorded from Xenopus laevis neurons in the presence of impermeant cadmium (100-500 microM) from the currents produced without cadmium but in the presence of permeant divalent cations (50-100 micro...

  5. Proton activity of the Sun in current solar cycle 24

    CERN Document Server

    Li, Chuan; Fang, Cheng

    2014-01-01

    We present a study of 7 large solar proton events (SPEs) of current solar cycle 24 (from 2009 January up to date). They were recorded by GOES spacecraft with highest proton fluxes over 200 pfu for energies $>$10 MeV. In situ particle measurements show that: (1) The profiles of the proton fluxes are highly dependent of the locations of their solar sources, namely flares or coronal mass ejections (CMEs); (2) The solar particle release (SPR) times fall in the decay phase of the flare emission, and are in accordance with the times when the CMEs travel to an average height of 7.9 solar radii; (3) The time differences between the SPR and the flare peak are also dependent of the locations of the solar active regions (ARs). The results tend to support the concept of proton acceleration by the CME-driven shock, even though there exists a possibility of particle acceleration at flare site with subsequent perpendicular diffusion of accelerated particles in the interplanetary magnetic field (IMF). We derive the integral ...

  6. Fundamental Active Current Adaptive Linear Neural Networks for Photovoltaic Shunt Active Power Filters

    Directory of Open Access Journals (Sweden)

    Muhammad Ammirrul Atiqi Mohd Zainuri

    2016-05-01

    Full Text Available This paper presents improvement of a harmonics extraction algorithm, known as the fundamental active current (FAC adaptive linear element (ADALINE neural network with the integration of photovoltaic (PV to shunt active power filters (SAPFs as active current source. Active PV injection in SAPFs should reduce dependency on grid supply current to supply the system. In addition, with a better and faster harmonics extraction algorithm, the SAPF should perform well, especially under dynamic PV and load conditions. The role of the actual injection current from SAPF after connecting PVs will be evaluated, and the better effect of using FAC ADALINE will be confirmed. The proposed SAPF was simulated and evaluated in MATLAB/Simulink first. Then, an experimental laboratory prototype was also developed to be tested with a PV simulator (CHROMA 62100H-600S, and the algorithm was implemented using a TMS320F28335 Digital Signal Processor (DSP. From simulation and experimental results, significant improvements in terms of total harmonic distortion (THD, time response and reduction of source power from grid have successfully been verified and achieved.

  7. 垃圾焚烧炉渣活性激发及对水泥性能的影响%Stimulation of MSWI Bottom Ash Activity and Effects on Cement Performance

    Institute of Scientific and Technical Information of China (English)

    李相国; 宋留庆; 马保国; 方晨炜; 汪杰

    2012-01-01

    The author studied properties of cement that partially replaced by MWIS bottom ash as a cement admixture, and investigated slag cement' s activity of stimulating and environmental safety. The results show that: MWIS bottom ash is of weak activity, with bottom ash replaces cement increases, water for cement standard consistency slowly increased, setting time slightly extended, but has little effect on cement strength reduced. The dosage of MWIS bottom ash in PO 42.5 cement even reached 25 %. PO 32. 5 cement production requirements can be satisfied. In the aspects of stimulating the activity, the added of Ca-based activators into cement can improve the early and late strength (CaCl2 will result in late strength's retraction), Conversely, Na-based activators will reduce the intensity. MWIS bottom ash as cement admixture reduces the shrinkage of cement paste. MWIS bottom ash dosage of 35%, the mortar test block dissolution of heavy metal content is much lower than the limit of maximum allowable concentration of national standard and will not bring secondary pollution to the environment%通过外掺法研究了城市生活垃圾焚烧炉渣用作水泥混合材对水泥性能的影响,同时考察了炉渣活性激发和炉渣水泥的环境安全性.实验结果表明:炉渣具有较弱的火山灰活性,随着其掺入量的增加,水泥标准稠度用水量增加,凝结时间延长,水泥强度下降,当PO 42.5水泥中炉渣掺量达到25%时仍能达到PO 32.5水泥生产要求.在炉渣活性激发方面,钙系列激发剂能够提高炉渣水泥的早期和后期强度(CaCl2会使后期强度倒缩),钠系列激发剂均会降低其强度.炉渣的掺入能够降低水泥净浆化学收缩率.在炉渣掺量35%时,砂浆试块的重金属极限溶出含量远低于国家标准最高允许浓度,不会对环境带来二次污染.

  8. Cortical hyperpolarization-activated depolarizing current takes part in the generation of focal paroxysmal activities

    Science.gov (United States)

    Timofeev, Igor; Bazhenov, Maxim; Sejnowski, Terrence; Steriade, Mircea

    2002-01-01

    During paroxysmal neocortical oscillations, sudden depolarization leading to the next cycle occurs when the majority of cortical neurons are hyperpolarized. Both the Ca2+-dependent K+ currents (IK(Ca)) and disfacilitation play critical roles in the generation of hyperpolarizing potentials. In vivo experiments and computational models are used here to investigate whether the hyperpolarization-activated depolarizing current (Ih) in cortical neurons also contributes to the generation of paroxysmal onsets. Hyperpolarizing current pulses revealed a depolarizing sag in ≈20% of cortical neurons. Intracellular recordings from glial cells indirectly indicated an increase in extracellular potassium concentration ([K+]o) during paroxysmal activities, leading to a positive shift in the reversal potential of K+-mediated currents, including Ih. In the paroxysmal neocortex, ≈20% of neurons show repolarizing potentials originating from hyperpolarizations associated with depth-electroencephalogram positive waves of spike-wave complexes. The onset of these repolarizing potentials corresponds to maximal [K+]o as estimated from dual simultaneous impalements from neurons and glial cells. Computational models showed how, after the increased [K+]o, the interplay between Ih, IK(Ca), and a persistent Na+ current, INa(P), could organize paroxysmal oscillations at a frequency of 2–3 Hz. PMID:12089324

  9. A bottom hole motor

    Energy Technology Data Exchange (ETDEWEB)

    Kibishcher, G.B.; Karpenko, V.K.; Pogorelov, V.P.

    1982-01-01

    A bottom hole motor is proposed which includes a body, a push rod with a piston, a spindle, a mechanism for converting the reciprocal movement of the piston into rotation of the shaft and pump and drain cavities. In order to simplify the design the push rod is made with radial openings above and below the piston, while the shaft is made with two longitudinal channels at the level of the radial openings of the push rod on the diametrically opposite sides. The cavity of one channel is constantly connected with the pump cavity, while the other is permanently connected with the drain cavity.

  10. Top-Down and Bottom-Up Approaches in Engineering 1 T Phase Molybdenum Disulfide (MoS2 ): Towards Highly Catalytically Active Materials.

    Science.gov (United States)

    Chua, Chun Kiang; Loo, Adeline Huiling; Pumera, Martin

    2016-09-26

    The metallic 1 T phase of MoS2 has been widely identified to be responsible for the improved performances of MoS2 in applications including hydrogen evolution reactions and electrochemical supercapacitors. To this aim, various synthetic methods have been reported to obtain 1 T phase-rich MoS2 . Here, the aim is to evaluate the efficiencies of the bottom-up (hydrothermal reaction) and top-down (chemical exfoliation) approaches in producing 1 T phase MoS2 . It is established in this study that the 1 T phase MoS2 produced through the bottom-up approach contains a high proportion of 1 T phase and demonstrates excellent electrochemical and electrical properties. Its performance in the hydrogen evolution reaction and electrochemical supercapacitors also surpassed that of 1 T phase MoS2 produced through a top-down approach.

  11. Monitoring the onset, propagation, associated bedform migration, and wake of active turbidity currents on the Squamish prodelta slope

    Science.gov (United States)

    Hughes Clarke, J. E.; Pratomo, D. G.; Videira Marques, C. R.

    2012-12-01

    . Multibeam water column imagery is used to view the onset, development and decay of turbidity currents in channels on the Squamish prodelta slope. The 2011 program consisted of daily resurveys for a period of 120 days during the freshet period. The initial focus was on resolving bathymetric surface change. Typical morphologic change indicated intermittent upslope migration of in-channel bedforms, sometimes, but not always, associated with an upper slope discrete slide scar. As a serendipitous byproduct, it was found that the deep scattering layer in the fjord was occasionally perturbed by what appeared to be bottom-following intrusive flows. A distally-located, seabed-mounted ADCP confirmed 20 discrete turbidity current events. Surface lowered, optical backscatter profiles indicated that these intrusions were correlated with near-seabed turbidity peaks. In 2012, a week-long program was implemented using hourly resurveys of the channels around the low water spring tide periods. Repetitive underway optical backscatter and CTD profiles were collected extending along the active channels from the delta lip to 1000m offshore. These established the sediment load and relative buoyancy of the surface plume and the fact that the enhanced acoustic volume scattering below represented a descending rain of suspended sediments into the higher density saline lower layers. For several of the events, that descending plume was seen to markedly increase in turbidity close to the seabed, indicating a transition to hyperpycnal conditions. A drop of salinity was also associated with those near seabed high turbidity layers. Those events were followed by the onset of a turbidity current as interpreted from the acoustic volume scattering. The period of upslope bedform migration was restricted to the onset of basal turbidity and first appearance of the flow in the acoustic volume scattering. In the wake of the active flow, an anomalously low acoustic scattering cloud would appear above the

  12. Get Current: Switch on Clean Energy Activity Book

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Icing Branch Current Research Activities in Icing Physics

    Science.gov (United States)

    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.

  14. Power-Integrated Circuit Active Leakage Current Detector

    Directory of Open Access Journals (Sweden)

    M. F. Bulacio

    2012-01-01

    Full Text Available Most of the failures of induction motors become insulation faults, causing a permanent damage. Using differential current transformers, a system capable of insulation fault detection was developed, based on the differential relay protection scheme. Both signal injection and fault detection circuitry were integrated in a single chip. The proposed scheme is faster than other existing protection and not restricted to protect induction motors, but several other devices (such as IGBTs and systems. This paper explains the principle of operation of fault protection scheme and analyzes an integrated implementation through simulations and experimental results. A power-integrated circuit (PIC implementation is presented.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Current status of pyrazole and its biological activities.

    Science.gov (United States)

    Naim, Mohd Javed; Alam, Ozair; Nawaz, Farah; Alam, Md Jahangir; Alam, Perwaiz

    2016-01-01

    Pyrazole are potent medicinal scaffolds and exhibit a full spectrum of biological activities. This review throws light on the detailed synthetic approaches which have been applied for the synthesis of pyrazole. This has been followed by an in depth analysis of the pyrazole with respect to their medical significance. This follow-up may help the medicinal chemists to generate new leads possessing pyrazole nucleus with high efficacy.

  17. Proton currents constrain structural models of voltage sensor activation

    Science.gov (United States)

    Randolph, Aaron L; Mokrab, Younes; Bennett, Ashley L; Sansom, Mark SP; Ramsey, Ian Scott

    2016-01-01

    The Hv1 proton channel is evidently unique among voltage sensor domain proteins in mediating an intrinsic ‘aqueous’ H+ conductance (GAQ). Mutation of a highly conserved ‘gating charge’ residue in the S4 helix (R1H) confers a resting-state H+ ‘shuttle’ conductance (GSH) in VGCs and Ci VSP, and we now report that R1H is sufficient to reconstitute GSH in Hv1 without abrogating GAQ. Second-site mutations in S3 (D185A/H) and S4 (N4R) experimentally separate GSH and GAQ gating, which report thermodynamically distinct initial and final steps, respectively, in the Hv1 activation pathway. The effects of Hv1 mutations on GSH and GAQ are used to constrain the positions of key side chains in resting- and activated-state VS model structures, providing new insights into the structural basis of VS activation and H+ transfer mechanisms in Hv1. DOI: http://dx.doi.org/10.7554/eLife.18017.001 PMID:27572256

  18. A laboratory activity on the eddy current brake

    Science.gov (United States)

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

    2012-05-01

    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 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.

  19. Index of current water-resources activities in Ohio, 1985

    Science.gov (United States)

    Eberle, Michael

    1985-01-01

    This report summarizes the U. S. Geological Survey 's Water Resources Division 's program in Ohio in 1985. The work of the Ohio District is carried out through the District office in Columbus and a field office in New Philadelphia. Collection of basic data needed for continuing determination and evaluation of the quantity, quality, and use of Ohio 's water resources is the responsibility of the District 's Hydrologic Surveillance Section. The Hydrologic Investigations Section conducts analytical and interpretive water-resource appraisals describing the occurrence, availability, and the physical, chemical, and biological characteristics of surface and groundwater. In addition to introductory material describing the structure of the Ohio District, information is presented on current projects, sites at which basic surface- and groundwater data are collected , and reports of Ohio 's water resources published by the U.S. Geological Survey and cooperating agencies. (USGS)

  20. Processing NPP Bottoms by Ferrocyanide Precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Savkin, A. E.; Slastennikov Y. T.; Sinyakin O. G.

    2002-02-25

    The purpose of work is a laboratory test of a technological scheme for cleaning bottoms from radionuclides by use of ozonization, ferrocyanide precipitation, filtration and selective sorption. At carrying out the ferrocyanide precipitation after ozonization, the specific activity of bottoms by Cs{sup 137} is reduced in 100-500 times. It has been demonstrated that the efficiency of ferrocyanide precipitation depends on the quality of consequent filtration. Pore sizes of a filter has been determined to be less than 0.2 {micro}m for complete separation of ferrocyanide residue. The comparison of two technological schemes for cleaning bottoms from radionuclides, characterized by presence of the ferrocyanide precipitation stage has been performed. Application of the proposed schemes allows reducing volumes of radioactive waste in many times.

  1. Bottom-Up Earley Deduction

    CERN Document Server

    Erbach, G

    1995-01-01

    We propose a bottom-up variant of Earley deduction. Bottom-up deduction is preferable to top-down deduction because it allows incremental processing (even for head-driven grammars), it is data-driven, no subsumption check is needed, and preference values attached to lexical items can be used to guide best-first search. We discuss the scanning step for bottom-up Earley deduction and indexing schemes that help avoid useless deduction steps.

  2. Antimicrobial activity of carvacrol: current progress and future prospectives.

    Science.gov (United States)

    Nostro, Antonia; Papalia, Teresa

    2012-04-01

    During the last few years the scientific community has shown a considerable interest in the study of plant materials as sources of new compounds to be processed into antimicrobial agents. In this context, carvacrol, a monoterpenic phenol, has emerged for its wide spectrum activity extended to food spoilage or pathogenic fungi, yeast and bacteria as well as human, animal and plant pathogenic microorganisms including drug-resistant and biofilm forming microorganisms. The antibacterial activity of carvacrol has been attributed to its considerable effects on the structural and functional properties of cytoplasmatic membrane. The data reported in this review provide an overview of the published literature regarding the antimicrobial properties of carvacrol and the recent patents claimed in order to highlight its future applications as a new antimicrobial agent. These could concern either the natural preservation in the cosmetic and food industries or an alternative which supports the conventional antimicrobial protocols. Interestingly, carvacrol alone or associated with one or more synergistic products could be incorporated in different formulations for biomedical and food packaging applications. However, more detailed safety investigations and in vivo studies should be carried out so that this molecule could be used in the future.

  3. Application and interpretation of current autophagy inhibitors and activators

    Institute of Scientific and Technical Information of China (English)

    Ya-ping YANG; Li-fang HU; Hui-fen ZHENG; Cheng-jie MAO; Wei-dong HU; Kang-ping XIONG; Fen WANG

    2013-01-01

    Aut ophagy is the major intracellular degradation system,by which cytoplasmic materials are delivered to and degraded in the lysosome.As a quality control mechanism for cytoplasmic proteins and organelles,autophagy plays important roles in a variety of human diseases,including neurodegenerative diseases,cancer,cardiovascular disease,diabetes and infectious and inflammatory diseases.The discovery of ATG genes and the dissection of the signaling pathways involved in regulating autophagy have greatly enriched our knowledge on the occurrence and development of this lysosomal degradation pathway.In addition to its role in degradation,autophagy may also promote a type of programmed cell death that is different from apoptosis,termed type II programmed cell death.Owing to the dual roles of autophagy in cell death and the specificity of diseases,the exact mechanisms of autophagy in various diseases require more investigation.The application of autophagy inhibitors and activators will help us understand the regulation of autophagy in human diseases,and provide insight into the use of autophagy-targeted drugs.In this review,we summarize the latest research on autophagy inhibitors and activators and discuss the possibility of their application in human disease therapy.

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

    CERN Document Server

    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. Nanoelectronics: Thermoelectric Phenomena in «Bottom-Up» Approach

    Directory of Open Access Journals (Sweden)

    Yu.A. Kruglyak

    2014-04-01

    Full Text Available Thermoelectric phenomena of Seebeck and Peltier, quality indicators and thermoelectric optimization, ballistic and diffusive phonon heat current are discussed in the frame of the «bottom-up» approach of modern nanoelectronics.

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

    NARCIS (Netherlands)

    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

  7. The Current Case of Quinolones: Synthetic Approaches and Antibacterial Activity.

    Science.gov (United States)

    Naeem, Abdul; Badshah, Syed Lal; Muska, Mairman; Ahmad, Nasir; Khan, Khalid

    2016-03-28

    Quinolones are broad-spectrum synthetic antibacterial drugs first obtained during the synthesis of chloroquine. Nalidixic acid, the prototype of quinolones, first became available for clinical consumption in 1962 and was used mainly for urinary tract infections caused by Escherichia coli and other pathogenic Gram-negative bacteria. Recently, significant work has been carried out to synthesize novel quinolone analogues with enhanced activity and potential usage for the treatment of different bacterial diseases. These novel analogues are made by substitution at different sites--the variation at the C-6 and C-8 positions gives more effective drugs. Substitution of a fluorine atom at the C-6 position produces fluroquinolones, which account for a large proportion of the quinolones in clinical use. Among others, substitution of piperazine or methylpiperazine, pyrrolidinyl and piperidinyl rings also yields effective analogues. A total of twenty six analogues are reported in this review. The targets of quinolones are two bacterial enzymes of the class II topoisomerase family, namely gyrase and topoisomerase IV. Quinolones increase the concentration of drug-enzyme-DNA cleavage complexes and convert them into cellular toxins; as a result they are bactericidal. High bioavailability, relative low toxicity and favorable pharmacokinetics have resulted in the clinical success of fluoroquinolones and quinolones. Due to these superior properties, quinolones have been extensively utilized and this increased usage has resulted in some quinolone-resistant bacterial strains. Bacteria become resistant to quinolones by three mechanisms: (1) mutation in the target site (gyrase and/or topoisomerase IV) of quinolones; (2) plasmid-mediated resistance; and (3) chromosome-mediated quinolone resistance. In plasmid-mediated resistance, the efflux of quinolones is increased along with a decrease in the interaction of the drug with gyrase (topoisomerase IV). In the case of chromosome

  8. The Current Case of Quinolones: Synthetic Approaches and Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Abdul Naeem

    2016-03-01

    Full Text Available Quinolones are broad-spectrum synthetic antibacterial drugs first obtained during the synthesis of chloroquine. Nalidixic acid, the prototype of quinolones, first became available for clinical consumption in 1962 and was used mainly for urinary tract infections caused by Escherichia coli and other pathogenic Gram-negative bacteria. Recently, significant work has been carried out to synthesize novel quinolone analogues with enhanced activity and potential usage for the treatment of different bacterial diseases. These novel analogues are made by substitution at different sites—the variation at the C-6 and C-8 positions gives more effective drugs. Substitution of a fluorine atom at the C-6 position produces fluroquinolones, which account for a large proportion of the quinolones in clinical use. Among others, substitution of piperazine or methylpiperazine, pyrrolidinyl and piperidinyl rings also yields effective analogues. A total of twenty six analogues are reported in this review. The targets of quinolones are two bacterial enzymes of the class II topoisomerase family, namely gyrase and topoisomerase IV. Quinolones increase the concentration of drug-enzyme-DNA cleavage complexes and convert them into cellular toxins; as a result they are bactericidal. High bioavailability, relative low toxicity and favorable pharmacokinetics have resulted in the clinical success of fluoroquinolones and quinolones. Due to these superior properties, quinolones have been extensively utilized and this increased usage has resulted in some quinolone-resistant bacterial strains. Bacteria become resistant to quinolones by three mechanisms: (1 mutation in the target site (gyrase and/or topoisomerase IV of quinolones; (2 plasmid-mediated resistance; and (3 chromosome-mediated quinolone resistance. In plasmid-mediated resistance, the efflux of quinolones is increased along with a decrease in the interaction of the drug with gyrase (topoisomerase IV. In the case of

  9. Activation processes on GaAs photocathode by different currents of oxygen source

    Science.gov (United States)

    Miao, Zhuang; Shi, Feng; Cheng, Hongchang; Wang, Shufei; Zhang, Xiaohui; Yuan, Yuan; Chen, Chang

    2015-04-01

    In order to know the influence of activation processes on GaAs photocathodes, three GaAs samples were activated by a fixed current of cesium source and different currents of oxygen source. The current of caesium source is same during activation to ensure initial adsorption of caesium quantum is similar, which is the base to show the difference during alternation activation of caesium and oxygen. Analysed with the activation data, it is indicated that Cs-to-O current ratio of 1.07 is the optimum ratio to obtain higher sensitivity and better stability. According to double dipole model, stable and uniform double dipole layers of GaAs-O-Cs:Cs-O-Cs are formed and negative electron affinity is achieved on GaAs surface by activation with cesium and oxygen. The analytical result is just coincident with the model. Thus there is an efficient technological method to improve sensitivity and stability of GaAs photocathode.

  10. Modulatory effect of substance P on GABA-activated currents from rat dorsal root ganglion

    Institute of Scientific and Technical Information of China (English)

    Jun-qiang SI; Zhi-qin ZHANG; Chun-xia LI; Li-feng WANG; Yun-lei YANG; Zhi-wang LI

    2004-01-01

    AIM: To explore the modulatory effect of substance P (SP) on GABA-activated current of dorsal root ganglion (DRG) neurons in rat. METHODS: The whole-cell patch-clamp technique was used to record SP- and GABAactivated currents in neurons freshly dissociated from rat DRG neurons. Drugs were applied by rapid solution exchange. RESULTS: Application of SP (28/41, 68.5 %) and GABA (36/41, 88.2 %) could induce concentrationdependent inward current in some cells. SP-(10 μmol/L) and GABA (100 μmol/L)-activated inward currents were (244±83) pA (n=9) and (1.8±0.5) nA (n=13), respectively. The majority of GABA-activated current had obvious three processes, the peak value (Ip), the steady state (Iss) and the desensitization (Ia). The desensitization of GABAactivated current was a biphasic process, including fast and slow desensitization. However, pre-application of SP (0.001-1 μmol/L) could inhibit the GABA-activated inward current which was identified to be GABAA receptormediated current. The inhibitory effects were concentration-dependent. The inhibitory effect of SP on the peak value of GABA-activated current was more than the steady state of GABA-activated current. The inhibition of GABA-activated current by SP (0.1 μmol/L) was related to the time after application of SP, the inhibition of GABAactivated currents by SP reached the peak at about 4 min (49.8 %±7.2 %, n=7, P<0.01) and took about 12 min to get a full recovery. The inhibition of GABA-activated currents by SP was almost completely removed after blockade of PKC by H-7 with the re-patch clamp. CONCLUSION: Pre-application of SP exerts a more strong inhibitory effect on the peak value of GABA-activated current than the steady state of GABA-activated current.

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

    Science.gov (United States)

    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.

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

    CERN Document Server

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  16. A NEW METHOD TO CALCULATE COMPENSATION CURRENT IN PARALLEL ACTIVE POWER FILTER

    Directory of Open Access Journals (Sweden)

    Ahmet ALTINTAŞ

    2004-03-01

    Full Text Available Nowadays, active power filter plays an important role in reducing harmonic current and reactive power in power lines. The reliability and effectiveness of an active power filter depends basically on three characteristics. These are the modulation method, the design characteristics of the PWM modulator and the method implemented to generate compensation current. For the last one, there are many proposed methods. Most of them complicated and hence difficult to implement and adjust. In this study, a new method to calculate compensation current is improved and tested in single-phase parallel active power filter controlled by microcontroller. Experimental and simulation results are presented in the paper.

  17. Bottom dwelling animals: Benthos

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.

    the intertidal (shore and beach), sub tidal and offshore region. The coastal zone has the highest marine resources, the greatest concentration and diversity of marine life and critical habitats. It also has the most serious threats from the land-based activities...

  18. Selective regulation of current densities underlies spontaneous changes in the activity of cultured neurons.

    Science.gov (United States)

    Turrigiano, G; LeMasson, G; Marder, E

    1995-05-01

    We study the electrical activity patterns and the expression of conductances in adult stomatogastric ganglion (STG) neurons as a function of time in primary cell culture. When first plated in culture, these neurons had few active properties. After 1 d in culture they produced small action potentials that rapidly inactivated during maintained depolarization. After 2 d in culture they fired large action potentials tonically when depolarized, and their properties resembled very closely the properties of STG neurons pharmacologically isolated in the ganglion. After 3-4 d in culture, however, their electrical properties changed and they fired in bursts when depolarized. We characterized the currents expressed by these neurons in culture. They included two TTX-sensitive sodium currents, a calcium current, a delayed-rectifier-like current, a calcium-dependent potassium current, and two A-type currents. The changes in firing properties with time in culture were accompanied by an increase in inward and decrease in outward current densities. A single-compartment conductance-based model of an STG neuron was constructed by fitting the currents measured in the biological neurons. When the current densities in the model neuron were matched to those measured for the biological neurons in each activity state, the model neuron closely reproduced each state, indicating that the changes in current densities are sufficient to account for the changes in intrinsic properties. These data indicate that STG neurons isolated in culture change their intrinsic electrical properties by selectively adjusting the magnitudes of their ionic conductances.

  19. Muscarinic modulation of sodium current by activation of protein kinase C in rat hippocampal neurons.

    Science.gov (United States)

    Cantrell, A R; Ma, J Y; Scheuer, T; Catterall, W A

    1996-05-01

    Phosphorylation of brain Na+ channels by protein kinase C (PKC) decreases peak Na+ current and slows macroscopic inactivation, but receptor-activated modulation of Na+ currents via the PKC pathway has not been demonstrated. We have examined modulation of Na+ channels by activation of muscarinic receptors in acutely-isolated hippocampal neurons using whole-cell voltage-clamp recording. Application of the muscarinic agonist carbachol reduced peak Na+ current and slowed macroscopic inactivation at all potentials, without changing the voltage-dependent properties of the channel. These effects were mediated by PKC, since they were eliminated when the specific PKC inhibitor (PKCI19-36) was included in the pipette solution and mimicked by the extracellular application of the PKC activator, OAG. Thus, activation of endogenous muscarinic receptors on hippocampal neurons strongly modulates Na+ channel activity by activation of PKC. Cholinergic input from basal forebrain neurons may have this effect in the hippocampus in vivo.

  20. 75 FR 4612 - Agency Information Collection Activities: Notice of Request for Extension of Currently Approved...

    Science.gov (United States)

    2010-01-28

    ... construction time and traffic congestion; C. The development of engineering design criteria for innovative... Federal Highway Administration Agency Information Collection Activities: Notice of Request for Extension of Currently Approved Information Collection AGENCY: Federal Highway Administration (FHWA),...

  1. [Resource activation in clinical psychology and psychotherapy: review of theoretical issues and current research].

    Science.gov (United States)

    Groß, L J; Stemmler, M; de Zwaan, M

    2012-08-01

    This review summarises theoretical issues and current research on working with clients' resources and strengths in clinical psychology and psychotherapy. Resource activation is considered as an important common factor in psychotherapy. In general, resource activation means an explicit focus on resources, strengths and potentials of the clients. After defining the term resources, considerations with regard to therapeutic attitude, principles of resource activation, approaches to resource diagnostics and different research strategies are presented. Current research focuses especially on the relation between resource activation and process variables in out-patient treatment.

  2. Interleaved Buck Converter with Variable Number of Active Phases and a Predictive Current Sharing Scheme

    DEFF Research Database (Denmark)

    Jakobsen, Lars Tønnes; Garcia, O.; Oliver, J. A.

    2008-01-01

    The efficiency of an interleaved Buck converter is typically low at light load conditions because of the switching losses in each of the switching stages. Improvements in the converter efficiency can be achieved by dynamically changing the number of active phases depending on the load current. Th...... and shows that the predictive current equalisation scheme can equalise the phase currents in a single PWM period....

  3. Genetic activation of BK currents in vivo generates bidirectional effects on neuronal excitability.

    Science.gov (United States)

    Montgomery, Jenna R; Meredith, Andrea L

    2012-11-13

    Large-conductance calcium-activated potassium channels (BK) are potent negative regulators of excitability in neurons and muscle, and increasing BK current is a novel therapeutic strategy for neuro- and cardioprotection, disorders of smooth muscle hyperactivity, and several psychiatric diseases. However, in some neurons, enhanced BK current is linked with seizures and paradoxical increases in excitability, potentially complicating the clinical use of agonists. The mechanisms that switch BK influence from inhibitory to excitatory are not well defined. Here we investigate this dichotomy using a gain-of-function subunit (BK(R207Q)) to enhance BK currents. Heterologous expression of BK(R207Q) generated currents that activated at physiologically relevant voltages in lower intracellular Ca(2+), activated faster, and deactivated slower than wild-type currents. We then used BK(R207Q) expression to broadly augment endogenous BK currents in vivo, generating a transgenic mouse from a circadian clock-controlled Period1 gene fragment (Tg-BK(R207Q)). The specific impact on excitability was assessed in neurons of the suprachiasmatic nucleus (SCN) in the hypothalamus, a cell type where BK currents regulate spontaneous firing under distinct day and night conditions that are defined by different complements of ionic currents. In the SCN, Tg-BK(R207Q) expression converted the endogenous BK current to fast-activating, while maintaining similar current-voltage properties between day and night. Alteration of BK currents in Tg-BK(R207Q) SCN neurons increased firing at night but decreased firing during the day, demonstrating that BK currents generate bidirectional effects on neuronal firing under distinct conditions.

  4. Effect of Calcium-Activated Chloride Current Blockade on the Delayed Afterdepolarizations. Simulation Study

    Science.gov (United States)

    2007-11-02

    dog and rabbit ventricular cells [4, 6]. The ionic nature of Iti is still subject to debate. Several authors propose two ionic currents to contribute to...activated Cl currents in the heart: a computer model. Computers in Cardiology 1999; 26: 109-112. Julio Gomis-Tena Dolz U.P.V. Departamento de Ingeniería

  5. Active Damping of LLCL-Filter Resonance Based on LC-Trap Voltage or Current Feedback

    DEFF Research Database (Denmark)

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

    2016-01-01

    . Active damping is presently more efficient, and can easily be realized by feeding back a state variable. For the LCL-filter, the variable is usually its middle capacitor current. However, with computational delays considered, a simple proportional damper cannot be used with the capacitor current. Instead...

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Sensory deprivation regulates the development of the hyperpolarization-activated current in auditory brainstem neurons.

    Science.gov (United States)

    Hassfurth, Benjamin; Magnusson, Anna K; Grothe, Benedikt; Koch, Ursula

    2009-10-01

    Hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels are highly expressed in the superior olivary complex, the primary locus for binaural information processing. This hyperpolarization-activated current (I(h)) regulates the excitability of neurons and enhances the temporally precise analysis of the binaural acoustic cues. By using the whole-cell patch-clamp technique, we examined the properties of I(h) current in neurons of the lateral superior olive (LSO) and the medial nucleus of the trapezoid body (MNTB) before and after hearing onset. Moreover, we tested the hypothesis that I(h) currents are actively regulated by sensory input activity by performing bilateral and unilateral cochlear ablations before hearing onset, resulting in a chronic auditory deprivation. The results show that after hearing onset, I(h) currents are rapidly upregulated in LSO neurons, but change only marginally in neurons of the MNTB. We also found a striking difference in maximal current density, voltage dependence and activation time constant between the LSO and the MNTB in mature-like animals. Following bilateral cochlear ablations before hearing onset, the I(h) currents were scaled up in the LSO and scaled down in the MNTB. Consequently, in the LSO this resulted in a depolarized resting membrane potential and a lower input resistance of these neurons. This type of activity-dependent homeostatic change could thus result in an augmented response to the remaining inputs.

  8. Cell cycle-dependent activity of the volume- and Ca2+-activated anion currents in Ehrlich lettre ascites cells

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjaer; Bergdahl, Andreas; Christophersen, Palle

    2007-01-01

    Recent evidence implicates the volume-regulated anion current (VRAC) and other anion currents in control or modulation of cell cycle progression; however, the precise involvement of anion channels in this process is unclear. Here, Cl- currents in Ehrlich Lettre Ascites (ELA) cells were monitored...... during cell cycle progression, under three conditions: (i) after osmotic swelling (i.e., VRAC), (ii) after an increase in the free intracellular Ca2+ concentration (i.e., the Ca2+-activated Cl- current, CaCC), and (iii) under steady-state isotonic conditions. The maximal swelling-activated VRAC current......+ in the pipette), was unaltered from G0 to G1, but decreased in early S phase. A novel high-affinity anion channel inhibitor, the acidic di-aryl-urea NS3728, which inhibited both VRAC and CaCC, attenuated ELA cell growth, suggesting a possible mechanistic link between cell cycle progression and cell cycle...

  9. Negative-shift activation, current reduction and resurgent currents induced by β-toxins from Centruroides scorpions in sodium channels.

    Science.gov (United States)

    Schiavon, Emanuele; Pedraza-Escalona, Martha; Gurrola, Georgina B; Olamendi-Portugal, Timoteo; Corzo, Gerardo; Wanke, Enzo; Possani, Lourival D

    2012-02-01

    The β-toxins purified from the New World scorpion venoms of the Centruroides species affect several voltage-gated sodium channels (VGSCs) and thus are essential tools not only for the discrimination of different channel sub-types but also for studying the structure-function relationship between channels and toxins. This communication reports the results obtained with four different peptides purified from three species of Centruroides scorpions and assayed on seven distinct isoforms of VGSC (Na(v)1.1-Na(v)1.7) by specific functional analysis conducted through single cell electrophysiology. The toxins studied were CssII from Centruroides suffusus suffusus, Cll1 and Cll2 from Centruroides limpidus limpidus and a novel toxin from Centruroides noxius, which was characterized for the first time here. It has 67 amino acid residues and four disulfide bridges with a molecular mass of 7626 Da. Three different functional features were identified: current reduction of macroscopic conductance, left shift of the voltage-dependent activation and induction of resurgent currents at negative voltages following brief, strong depolarizations. The isoforms which revealed to be more affected resulted to be Na(v)1.6 > 1.1 > 1.2 and, for the first time, a β-toxin is here shown to induce resurgent current also in isoforms different from Na(v)1.6. Additionally, these results were analyzed with molecular modelling. In conclusion, although the four toxins have a high degree of identity, they display tri-modal function, each of which shows selectivity among the different sub-types of Na+ -channels. Thus, they are invaluable as tools for structure-function studies of β-toxins and offer a basis for the design of novel ion channel-specific drugs.

  10. The steady-state performance of a controlled current active filter

    Energy Technology Data Exchange (ETDEWEB)

    Duke, R.M. (Univ. of Canterbury, Christchurch (New Zealand). Dept. of Electrical and Electronic Engineering); Round, S.D. (Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Electrical Engineering)

    1993-04-01

    An active filter that uses a high-frequency D-class asynchronous switching inverter for power system current distortion compensation is described. The distortion compensation technique involves deriving a signal corresponding to the distortion component of load current, and inverting and amplifying this signal for addition back to the supply current to cancel the load current distortion. A synthetic sinusoid is used to determine the distortion component in the time domain. Extensive computed and experimental results, illustrating the system's steady-state performance and ability to reduce the current harmonic distortion components, are presented. An intelligent controller is proposed to maintain the active filter's performance at the optimal operating point under varying load conditions.

  11. Low-level electrical currents and brain indicators of behavioral activation

    Directory of Open Access Journals (Sweden)

    F. Lolas

    1977-12-01

    Full Text Available Distinguishing between slow brain potential correlates of arousal and activation on the basis of their functional role and temporal involvement during a reaction-time task, data are presented which suggest that weak electrical polarizing currents applied to the head in human subjects modify predominantly activation indicators rather than arousal ones.

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

    DEFF Research Database (Denmark)

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

    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...

  13. Characterization of bottom sediments from Osaka Bay, Japan

    Science.gov (United States)

    Tokunaga, S.; Hoshika, A.; Tatsumoto, H.

    1995-06-01

    The physical, chemical, and dewatering characteristics of 19 bottom sediments from Osaka Bay, Japan, have been analyzed to aid in the development of sediments in the coastal bay area. The sediments in the east near Osaka Port were highly polluted from the influence of human activities and were difficult to dewater. These sediments were composed of fine particles, low in pH, zetapotential, and initial settling rate, and were high in ignition loss, metal concentrations, compression volume, specific resistance, cake water content, and drying index. However, the sediments near Akashi Channel showed the reverse where they are affected by strong tidal current. A correlation analysis has been made of all the parameters. There are significant relationships between all the dewatering parameters. Therefore, sediments difficult to dewater by gravity settling are also difficult to dewater by vacuum filtration and solar evaporation. Sediments containing fine particles and pollutants are difficult to dewater. Several forms of pollutants can occur in the sediments.

  14. Hyperpolarization-Activated Current, , in Mathematical Models of Rabbit Sinoatrial Node Pacemaker Cells

    Directory of Open Access Journals (Sweden)

    Arie O. Verkerk

    2013-01-01

    Full Text Available A typical feature of sinoatrial (SA node pacemaker cells is the presence of an ionic current that activates upon hyperpolarization. The role of this hyperpolarization-activated current, , which is also known as the “funny current” or “pacemaker current,” in the spontaneous pacemaker activity of SA nodal cells remains a matter of intense debate. Whereas some conclude that plays a fundamental role in the generation of pacemaker activity and its rate control, others conclude that the role of is limited to a modest contribution to rate control. The ongoing debate is often accompanied with arguments from computer simulations, either to support one's personal view or to invalidate that of the antagonist. In the present paper, we review the various mathematical descriptions of that have been used in computer simulations and compare their strikingly different characteristics with our experimental data. We identify caveats and propose a novel model for based on our experimental data.

  15. Current Limitations and Recommendations to Improve Testing for the Environmental Assessment of Endocrine Active Substances

    DEFF Research Database (Denmark)

    Coady, Katherine K; Biever, Ronald C; Denslow, Nancy D

    2016-01-01

    evaluate whether a chemical possesses endocrine activity and whether this activity can result in adverse outcomes either to humans or the environment. Current test systems include in silico, in vitro and in vivo techniques focused on detecting potential endocrine activity, and in vivo tests that collect...... apical data to detect possible adverse effects. These test systems are currently designed to robustly assess endocrine activity and/or adverse effects in the estrogen, androgen, and thyroid hormone signaling pathways; however, there are some limitations of current test systems for evaluating endocrine...... existing test methods are resource intensive in regard to time, cost, and use of animals. However, based on recent experiences, there are opportunities to improve approaches to, and guidance for existing test methods, and reduce uncertainty. For example, in vitro high throughput screening could be used...

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

    2005-01-01

    This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearised versions of the model are analysed to determine how gain, time constants and right half plane zeros (caused by the shrink-and-swell phenomenon) depend on the steam flow load. Furthermore...... the interactions in the system are inspected to analyse potential benefit from using a multivariable control strategy in favour of the current strategy based on single loop theory. An analysis of the nonlinear model is carried out to further determine the nonlinear characteristics of the boiler system...

  18. Niflumic acid reduces the hyperpolarization-activated current (I(h)) in rod photoreceptor cells.

    Science.gov (United States)

    Satoh, T O; Yamada, M

    2001-08-01

    We examined the effects of niflumic acid (NFA), a chloride channel blocker, on the hyperpolarization-activated current (I(h)) in newt rod photoreceptors. At 100 microM, NFA delayed the activation of I(h) induced by hyperpolarizing voltage pulses to -83 mV from a holding potential of -43 mV, and reduced the steady-state current. However, reduction by NFA was weakened when I(h) was activated by hyperpolarizing steps to -123 mV, suggesting that these effects were voltage-dependent. The suppressive effects of NFA on I(h) were accompanied by a negative shift in activation voltage. NFA also delayed the relaxation of I(h) tail currents, showing that this drug also inhibited deactivation of the current. The reversal potential and the fully activated conductance were not affected. These observations suggest that NFA reduces I(h) by modifying the gating kinetics of the underlying channels. The suppressive actions of NFA remained when intracellular Ca2+ was strongly chelated, and the failure of suppression by NFA in inside-out patches suggests that the agent may act on the I(h) channel from the extracellular side. These results, obtained in rod photoreceptors, are consistent with similar effects of NFA on I(f) in cardiac myocytes, suggesting that both currents share similar pharmacological properties.

  19. Culture from the Bottom Up

    Science.gov (United States)

    Atkinson, Dwight; Sohn, Jija

    2013-01-01

    The culture concept has been severely criticized for its top-down nature in TESOL, leading arguably to its falling out of favor in the field. But what of the fact that people do "live culturally" (Ingold, 1994)? This article describes a case study of culture from the bottom up--culture as understood and enacted by its individual users.…

  20. Building from the Bottom Up

    Science.gov (United States)

    2003-05-01

    through billions of years of prebiotic and molecular selection and evolution, there are bio-organic by Shuguang Zhang Building from the bottom up... Health , Du Pont-MIT Alliance, and the Whitaker Foundation. I also gratefully acknowledge Intel Corporation Academic Program for the generous donation

  1. Three-dimensional ventricular activation imaging by means of equivalent current source modeling and estimation.

    Science.gov (United States)

    Liu, Z; Liu, C; He, B

    2006-01-01

    This paper presents a novel electrocardiographic inverse approach for imaging the 3-D ventricular activation sequence based on the modeling and estimation of the equivalent current density throughout the entire myocardial volume. The spatio-temporal coherence of the ventricular excitation process is utilized to derive the activation time from the estimated time course of the equivalent current density. At each time instant during the period of ventricular activation, the distributed equivalent current density is noninvasively estimated from body surface potential maps (BSPM) using a weighted minimum norm approach with a spatio-temporal regularization strategy based on the singular value decomposition of the BSPMs. The activation time at any given location within the ventricular myocardium is determined as the time point with the maximum local current density estimate. Computer simulation has been performed to evaluate the capability of this approach to image the 3-D ventricular activation sequence initiated from a single pacing site in a physiologically realistic cellular automaton heart model. The simulation results demonstrate that the simulated "true" activation sequence can be accurately reconstructed with an average correlation coefficient of 0.90, relative error of 0.19, and the origin of ventricular excitation can be localized with an average localization error of 5.5 mm for 12 different pacing sites distributed throughout the ventricles.

  2. Paralleling power MOSFETs in their active region: Extended range of passively forced current sharing

    Science.gov (United States)

    Niedra, Janis M.

    1989-01-01

    A simple passive circuit that improves current balance in parallelled power MOSFETs that are not precisely matched and that are operated in their active region from a common gate drive are exhibited. A nonlinear circuit consisting of diodes and resistors generates the differential gate potential required to correct for unbalance while maintaining low losses over a range of current. Also application of a thin tape wound magnetic core to effect dynamic current balance is reviewed, and a simple theory is presented showing that for operation in the active region the branch currents tend to revert to their normal unbalanced values even if the core is not driven into saturation. Results of several comparative experiments are given.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. FCCP depolarizes plasma membrane potential by activating proton and Na+ currents in bovine aortic endothelial cells.

    Science.gov (United States)

    Park, Kyu-Sang; Jo, Inho; Pak, Kim; Bae, Sung-Won; Rhim, Hyewhon; Suh, Suk-Hyo; Park, Jin; Zhu, Hong; So, Insuk; Kim, Ki Whan

    2002-01-01

    We investigated the effects of carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP), a protonophore and uncoupler of mitochondrial oxidative phosphorylation in mitochondria, on plasma membrane potential and ionic currents in bovine aortic endothelial cells (BAECs). The membrane potential and ionic currents of BAECs were recorded using the patch-clamp technique in current-clamp and voltage-clamp modes, respectively. FCCP activated ionic currents and depolarized the plasma membrane potential in a dose-dependent manner. Neither the removal of extracellular Ca2+ nor pretreatment with BAPTA/AM affected the FCCP-induced currents, implying that the currents are not associated with the FCCP-induced intracellular [Ca2+]i increase. FCCP-induced currents were significantly influenced by the changes in extracellular or intracellular pH; the increased proton gradient produced by lowering the extracellular pH or intracellular alkalinization augmented the changes in membrane potential and ionic currents caused by FCCP. FCCP-induced currents were significantly reduced under extracellular Na+-free conditions. The reversal potentials of FCCP-induced currents under Na+-free conditions were well fitted to the calculated equilibrium potential for protons. Interestingly, FCCP-induced Na+ transport (subtracted currents, I(control)- I(Na+-free) was closely dependent on extracellular pH, whereas FCCP-induced H+transport was not significantly affected by the absence of Na+. These results suggest that the FCCP-induced ionic currents and depolarization, which are strongly dependent on the plasmalemmal proton gradient, are likely to be mediated by both H+ and Na+ currents across the plasma membrane. The relationship between H+ and Na+ transport still needs to be determined.

  5. β-pompilidotoxin modulates spontaneous activity and persistent sodium currents in spinal networks.

    Science.gov (United States)

    Magloire, V; Czarnecki, A; Anwander, H; Streit, J

    2011-01-13

    The origin of rhythm generation in mammalian spinal cord networks is still poorly understood. In a previous study, we showed that spontaneous activity in spinal networks takes its origin in the properties of certain intrinsically spiking interneurons based on the persistent sodium current (INaP). We also showed that depolarization block caused by a fast inactivation of the transient sodium current (INaT) contributes to the generation of oscillatory activity in spinal cord cultures. Recently, a toxin called beta-pompilidotoxin (β-PMTX) that slows the inactivation process of tetrodotoxin (TTX)-sensitive sodium channels has been extracted from the solitary wasp venom. In the present study, we therefore investigated the effect of β-PMTX on rhythm generation and on sodium currents in spinal networks. Using intracellular recordings and multielectrode array (MEA) recordings in dissociated spinal cord cultures from embryonic (E14) rats, we found that β-PMTX reduces the number of population bursts and increases the background asynchronous activity. We then uncoupled the network by blocking all synaptic transmission (APV, CNQX, bicuculline and strychnine) and observed that β-PMTX increases both the intrinsic activity at individual channels and the number of intrinsically activated channels. At the cellular level, we found that β-PMTX has two effects: it switches 58% of the silent interneurons into spontaneously active interneurons and increases the firing rate of intrinsically spiking cells. Finally, we investigated the effect of β-PMTX on sodium currents. We found that this toxin not only affects the inactivation of INaT but also increases the peak amplitude of the persistent sodium current (INaP). Altogether, theses findings suggest that β-PMTX acting on INaP and INaT enhances intrinsic activity leading to a profound modulation of spontaneous rhythmic activity in spinal networks.

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

    Institute of Scientific and Technical Information of China (English)

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  9. Effects of SDPNFLRF-amide (PF1) on voltage-activated currents in Ascaris suum muscle.

    Science.gov (United States)

    Verma, S; Robertson, A P; Martin, R J

    2009-02-01

    Helminth infections are of significant concern in veterinary and human medicine. The drugs available for chemotherapy are limited in number and the extensive use of these drugs has led to the development of resistance in parasites of animals and humans (Geerts and Gryseels, 2000; Kaplan, 2004; Osei-Atweneboana et al., 2007). The cyclooctadepsipeptide, emodepside, belongs to a new class of anthelmintic that has been released for animal use in recent years. Emodepside has been proposed to mimic the effects of the neuropeptide PF1 on membrane hyperpolarization and membrane conductance (Willson et al., 2003). We investigated the effects of PF1 on voltage-activated currents in Ascaris suum muscle cells. The whole cell voltage-clamp technique was employed to study these currents. Here we report two types of voltage-activated inward calcium currents: transient peak (I(peak)) and a steady-state (I(ss)). We found that 1microM PF1 inhibited the two calcium currents. The I(peak) decreased from -146nA to -99nA (P=0.0007) and the I(ss) decreased from -45nA to -12nA (P=0.002). We also found that PF1 in the presence of calcium increased the voltage-activated outward potassium current (from 521nA to 628nA (P=0.004)). The effect on the potassium current was abolished when calcium was removed and replaced with cobalt; it was also reduced at a higher concentration of PF1 (10microM). These studies demonstrate a mechanism by which PF1 decreases the excitability of the neuromuscular system by modulating calcium currents in nematodes. PF1 inhibits voltage-activated calcium currents and potentiates the voltage-activated calcium-dependent potassium current. The effect on a calcium-activated-potassium channel appears to be common to both PF1 and emodepside (Guest et al., 2007). It will be of interest to investigate the actions of emodepside on calcium currents to further elucidate the mechanism of action.

  10. Evaluation of reference current extraction methods for DSP implementation in active power filters

    Energy Technology Data Exchange (ETDEWEB)

    Vardar, K.; Akpinar, E.; Suergevil, T. [Dokuz Eylul University, Department of Electrical and Electronics Engineering, Kaynaklar Kampusu, 35160 Buca, Izmir (Turkey)

    2009-10-15

    Generation of current references constitutes an important part in the control of active power filters (APFs) used in power system, since any inaccuracy in reference currents yields to incorrect compensation. In this paper, harmonic detection methods for generating reference currents have been evaluated on the basis of three-phase balanced and unbalanced load currents processed in the digital signal processor (DSP). The advantages and disadvantages of several methods found in the literature have been discussed on the basis of simulation results. Three of these methods have been programmed in the TMS320F2812 digital signal processor (DSP) unit and their performances are evaluated from the viewpoint of practical considerations. Finally, instantaneous reactive power method to estimate the APF reference currents is implemented and its practical results obtained under balanced and unbalanced loads are given. (author)

  11. Spatial autocorrelation in the response of soft-bottom marine benthos to gas extraction activities: the case of amphipods in the Ionian Sea.

    Science.gov (United States)

    Fiorentino, Dario; Caruso, Tancredi; Terlizzi, Antonio

    2012-08-01

    The spatial distributions of marine fauna and of pollution are both highly structured, and thus the resulting high levels of autocorrelation may invalidate conclusions based on classical statistical approaches. Here we analyse the close correlation observed between proxies for the disturbance associated with gas extraction activities and amphipod distribution patterns around four hydrocarbon platforms. We quantified the amount of variation independently accounted for by natural environmental variables, proxies for the disturbance caused by platforms, and spatial autocorrelation. This allowed us to demonstrate how each of these three factors significantly affects the community structure of amphipods. Sophisticated statistical techniques are required when taking into account spatial autocorrelation; nevertheless our data demonstrate that this approach not only enables the formulation of robust statistical inferences but also provides a much deeper understanding of the subtle interactions between human disturbance and natural factors affecting the structure of marine invertebrates communities.

  12. Active power filter for medium voltage networks with predictive current control

    Energy Technology Data Exchange (ETDEWEB)

    Verne, Santiago A.; Valla, Maria I. [Laboratorio de Electronica Industrial, Control e Instrumentacion (LEICI), Facultad de Ingenieria, Universidad Nacional de La Plata and CONICET, La Plata (Argentina)

    2010-12-15

    A transformer less Shunt Active Power Filter (SAPF) for medium voltage distribution networks based on Multilevel Diode Clamped Inverter is presented in this paper. Converter current control is based on a Model Predictive strategy, which gives very fast current response. Also, the algorithm includes voltage balancing capability which is essential for proper converter operation. The presented current control algorithm is naturally applicable to converters with an arbitrary number of levels with reduced computational effort by virtue of the incorporation of switching restrictions which are necessary for reliable converter operation. The performance of the proposed algorithm is evaluated by means of computer simulations. (author)

  13. Current Research Activities in Drive System Technology in Support of the NASA Rotorcraft Program

    Science.gov (United States)

    Handschuh, Robert F.; Zakrajsek, James J.

    2006-01-01

    Drive system technology is a key area for improving rotorcraft performance, noise/vibration reduction, and reducing operational and manufacturing costs. An overview of current research areas that support the NASA Rotorcraft Program will be provided. Work in drive system technology is mainly focused within three research areas: advanced components, thermal behavior/emergency lubrication system operation, and diagnostics/prognostics (also known as Health and Usage Monitoring Systems (HUMS)). Current research activities in each of these activities will be presented. Also, an overview of the conceptual drive system requirements and possible arrangements for the Heavy Lift Rotorcraft program will be reviewed.

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

    Science.gov (United States)

    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. Single channel currents of different amplitude activated by glutamate in a tonic (slow) crayfish muscle.

    Science.gov (United States)

    Finger, W; Pareto, A

    1987-09-11

    Single channel currents were recorded by means of the patch-clamp technique from a tonic (slow) crayfish muscle in the presence of 5 mM glutamate. The experiments were carried out with 'Gigaohm-seals' in the 'cell-attached' mode at 15-17 degrees C. Five classes of single channel currents with different mean amplitudes were resolved: i1 = -0.75 +/- 0.43 (S.D.) pA, i2 = -1.4 +/- 0.4 pA, i3 = -3.5 +/- 0.63 pA, i4 = -8.5 +/- 0.92 pA and i5 approximately equal to 2 X i4, i2, i3 and i4 were recorded at resting membrane potential, Eo approximately equal to -80 mV (pipette potential Vp = 0), while i1 and i5 were recorded at 40 mV hyperpolarized to Eo (Vp = +40 mV). The current most frequently seen was i4 which is the excitatory glutamate-activated single channel current recorded previously by Franke et al. The membrane reversal potentials and channel conductances for i2 and i4 were estimated to be +60 mV (Eo + 140 mV), 13 pS for i2 and +40 mV (Eo + 120 mV), 80 pS for i4. It was assumed that up to 40 i1 currents could superpose in a single patch to generate a DC current of up to -30 pA with current fluctuations the intensity of which increased with the DC current amplitude. Often variable combinations of i1 to i4 currents could be recorded simultaneously in a single patch. In particular, simultaneous activity of i1, i4; i2, i4 and i3, i4 currents was observed in different single patches.

  16. Pharmacological activation of rapid delayed rectifier potassium current suppresses bradycardia-induced triggered activity in the isolated guinea pig heart

    DEFF Research Database (Denmark)

    Hansen, Rie Schultz; Olesen, Søren-Peter; Grunnet, Morten

    2007-01-01

    arrhythmias. We present here data that support that NS3623 affects native I(Kr) and report the effects that activating this potassium current have in the intact guinea pig heart. In Langendorff-perfused hearts, the compound showed a concentration-dependent shortening of action potential duration, which...

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

    Science.gov (United States)

    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.

  18. Archive of Digital Boomer Sub-bottom Data Collected During USGS Field Activities 97LCA01, 97LCA02, and 97LCA03, West-Central and East Coast Florida, February through July 1997

    Science.gov (United States)

    Forde, Arnell S.; Dadisman, Shawn V.; Metz, Patricia A.; Tihansky, Ann B.; Davis, Jeffrey B.; Wiese, Dana S.

    2011-01-01

    From February through July of 1997, the U.S. Geological Survey (USGS) conducted geophysical surveys of several Florida water bodies as part of the USGS Lakes and Coastal Aquifers (LCA) study. These areas include Lakes Dosson, Halfmoon and Round in west-central Florida and Sebastian Inlet and Indian River Lagoon on the east coast of the State. Field activity 97LCA01 was conducted in cooperation with the Southwest Florida Water Management District (SWFWMD), and field activities 97LCA02 and 97LCA03 were conducted in cooperation with the St. Johns River Water Management District (SJRWMD). This report serves as an archive of unprocessed digital boomer sub-bottom data, trackline maps, navigation files, Geographic Information System (GIS) files, observer's logbook, and formal Federal Geographic Data Committee (FGDC) metadata. Filtered and gained (showing a relative increase in signal amplitude) digital images of the seismic profiles are also provided. Refer to the Acronyms page for expansions of acronyms and abbreviations used in this report.

  19. Temperature dependence of rapidly adapting mechanically activated currents in rat dorsal root ganglion neurons.

    Science.gov (United States)

    Jia, Zhanfeng; Ling, Jennifer; Gu, Jianguo G

    2012-08-01

    Rapidly adapting mechanically activated channels (RA) are expressed on somatosensory neurons and thought to play a role in mechanical transduction. Because mechanical sensations can be significantly affected by temperatures, we examined thermal sensitivity of RA currents in cultured dorsal root ganglion (DRG) neurons to see if RA channel activity is highly temperature-dependent. RA currents were evoked from DRG neurons by membrane displacements and recorded by the whole-cell patch-clamp recording technique. We found that RA currents were significantly enhanced by warming temperatures from 22 to 32 °C and reduced by cooling temperatures from 24 to 14 °C. RA channel activation exhibited steep temperature-dependence with a large temperature coefficient (Q10>5) and a high activation energy (Ea>30 kcal/mol). We further showed that RA channel activation by mechanical stimulation led to membrane depolarization, which could result in action potential firing at 22 °C or 32 °C but not at 14 °C. Taken together, our results provide the measurements of thermal dynamics and activation energy of RA channels, and suggest that a high energy barrier is present for RA channels to open. These findings are in agreement with temperature sensitivity of mechanical sensations in mammals.

  20. Osteoclast spreading kinetics are correlated with an oscillatory activation of a calcium-dependent potassium current.

    Science.gov (United States)

    Espinosa, Leon; Paret, Laurent; Ojeda, Carlos; Tourneur, Yves; Delmas, Pierre D; Chenu, Chantal

    2002-10-01

    Cell movement and spreading involve calcium-dependent processes and ionic channel activation. During bone resorption, osteoclasts alternate between spread, motile and resorptive phases. We investigated whether the electrical membrane properties of osteoclasts were linked to their membrane morphological changes. Rabbit osteoclasts were recorded by time-lapse videomicroscopy performed simultaneously with patch-clamp whole cell and single channel recordings. Original image analysis methods were developed and used to demonstrate for the first time an oscillatory activation of a spontaneous membrane current in osteoclasts, which is directly correlated to the membrane movement rate. This current was identified as a calcium-dependent potassium current (IK(Ca)) that is sensitive to both charybdotoxin and apamin and was generated by a channel with unitary conductance of approximately 25+/-2 pS. Blockade of this current also decreased osteoclast spreading and inhibited bone resorption in vitro, demonstrating a physiological role for this current in osteoclast activity. These results establish for the first time a temporal correlation between lamellipodia formation kinetics and spontaneous peaks of IK(Ca), which are both involved in the control of osteoclast spreading and bone resorption.

  1. Cesium blockade of delayed outward currents and electrically induced pacemaker activity in mammalian ventricular myocardium.

    Science.gov (United States)

    Meier, C F; Katzung, B G

    1981-05-01

    The effects of Cs+, 5-25 mM, were studied in cat and guinea pig papillary muscles using voltage clamp and current clamp techniques. In solutions containing normal K+, the major effects of Cs+ were depolarization of the resting potential and reduction of the delayed outward current (ixl) between -80 and -20 mV. Both inward and outward portions of the isochronal current voltage relation (l-s clamps) were reduced by extracellular Cs+. This resulted in a substantial reduction of inward rectification and, by subtraction from the normal I-V relationship, the definition of a Cs+-sensitive component of current. Under current clamp conditions, 5-10 mM Cs+ produced a dose-dependent slowing of repetitive firing induced by depolarization. At higher concentrations (25 mM) the resting potential was depolarized and repetitive activity could not be induced by further depolarization. However, release of hyperpolarizing pulses was followed by prolonged bursts of repetitive action potentials, suggesting partial reversal of blockade or participation of another pacemaker process. The experimental results and a numerical simulation show that under readily attainable conditions, reduction in an outward pacemaker current may slow pacemaker activity.

  2. Slamming Testing of Facetted Bottom

    Science.gov (United States)

    2013-11-26

    Technical Report DATES COVERED (From - To) 01 May 2010-31 Aug2013 4. TITLE AND SUBTITLE Slamming Testing of Facetted Bottom 5a. CONTRACT NUMBER...of fast craft are due to slamming , or hydrodynamic impact. A 9 meter long steel / composite hybrid slamming load test facility has been employed for...the purpose of furthering understanding of the slamming phenomenon. This craft is heavily instrumented with strain gages, accelerometers, cameras, an

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Frequency Response Analysis of Current Controllers for Selective Harmonic Compensation in Active Power Filters

    DEFF Research Database (Denmark)

    Lascu, C.; Asiminoaei, L.; Boldea, I.;

    2009-01-01

    This paper compares four current control structures for selective harmonic compensation in active power filters. All controllers under scrutiny perform the harmonic compensation by using arrays of resonant controllers, one for the fundamental and one for each harmonic of interest, in order to ach...

  5. Urinary plasmin activates collecting duct ENaC current in preeclampsia

    DEFF Research Database (Denmark)

    Buhl, KB; Friis, Ulla Glenert; Svenningsen, Per;

    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...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    DEFF Research Database (Denmark)

    Cordeiro, Jonathan M; Callø, Kirstine; Moise, N Sydney

    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 ...

  8. Active Flow Control of Lifting Surface With Flap-Current Activities and Future Directions

    Science.gov (United States)

    Ahmadi, G.; Marzocca, P.; Jha, R.; Alstorm, B.; Obied, S.; Kabir, P.; Shahrabi, A.

    2010-01-01

    The main objective is to develop effective control strategies for separation control of an airfoil with a single hinge flap. The specific objectives are: Develop an active control architecture for flow control around an airfoil with flap. Design, fabricate, a wind tunnel test of a high lift wing (with flap) with integrated actuators and sensors. Design, development and fabrication of synthetic jet actuators. Develop appropriate control strategy for application to the airfoil. Wind tunnel testing of the high lift wing at various angles of attack and flap positions with closed loop control.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Research on Proximity Magnetic Field Influence in Measuring Error of Active Electronic Current Transformers

    Directory of Open Access Journals (Sweden)

    Wu Weijiang

    2016-01-01

    Full Text Available The principles of the active electronic current transformer (ECT are introduced, and the mechanism of how a proximity magnetic field can influence the measuring of errors is analyzed from the perspective of the sensor section of the ECT. The impacts on active ECTs created by three-phase proximity magnetic field with invariable distance and variable distance are simulated and analyzed. The theory and simulated analysis indicate that the active ECTs are sensitive to proximity magnetic field under certain conditions. According to simulated analysis, a product structural design and the location of transformers at substation sites are suggested for manufacturers and administration of power supply, respectively.

  11. Inhibition of the hyperpolarization-activated current (if) of rabbit SA node myocytes by niflumic acid.

    Science.gov (United States)

    Accili, E A; DiFrancesco, D

    1996-03-01

    The effects of the amphiphilic substance niflumic acid (NFA) were examined in myocytes isolated from the sino-atrial node of the rabbit heart. NFA (50 and 500 microM), for 30-60 s, produced a reversible negative chronotropic effect by reducing the rate of diastolic depolarization, suggesting an inhibitory effect on the hyperpolarization-activated pacemaker current (if). NFA (from 0.05 to 500 microM) inhibited if by modifying the current kinetics, without alteration of the conductance. This was shown by evidence indicating that: (1) NFA inhibited if during hyperpolarizing pulses to the mid-point of if activation but not at fully activating voltages; (2) the slope and reversal potential of the fully activated current/voltage (I/V) relation were not altered by NFA, indicating no change in slope conductance or ion selectivity; and (3) hyperpolarizing ramp protocols confirmed the lack of action of 50 microM NFA on the fully activated current and a shift of approximately -8 mV. Although similar to inhibition by acetylcholine (ACh), inhibition by NFA was only partly additive with the action of ACh and was not altered by atropine or pertussis toxin, both of which eliminated the action of ACh. The effect of NFA was present after stimulation of adenylate cyclase by forskolin and after inhibition of phosphodiesterase by isobutylmethylxanthine (IBMX). In cell-attached patch measurements, NFA applied externally did not affect if measured in the patch. Finally, application of NFA to the cytoplasmic side of excised patches did not alter the current in the absence or presence of adenosine 3',5'-cyclic monophosphate (cAMP). These results suggest an external, membrane-delimited action of NFA on if.

  12. Hyperpolarization-Activated Current Induces Period-Doubling Cascades and Chaos in a Cold Thermoreceptor Model

    Science.gov (United States)

    Xu, Kesheng; Maidana, Jean P.; Caviedes, Mauricio; Quero, Daniel; Aguirre, Pablo; Orio, Patricio

    2017-01-01

    In this article, we describe and analyze the chaotic behavior of a conductance-based neuronal bursting model. This is a model with a reduced number of variables, yet it retains biophysical plausibility. Inspired by the activity of cold thermoreceptors, the model contains a persistent Sodium current, a Calcium-activated Potassium current and a hyperpolarization-activated current (Ih) that drive a slow subthreshold oscillation. Driven by this oscillation, a fast subsystem (fast Sodium and Potassium currents) fires action potentials in a periodic fashion. Depending on the parameters, this model can generate a variety of firing patterns that includes bursting, regular tonic and polymodal firing. Here we show that the transitions between different firing patterns are often accompanied by a range of chaotic firing, as suggested by an irregular, non-periodic firing pattern. To confirm this, we measure the maximum Lyapunov exponent of the voltage trajectories, and the Lyapunov exponent and Lempel-Ziv's complexity of the ISI time series. The four-variable slow system (without spiking) also generates chaotic behavior, and bifurcation analysis shows that this is often originated by period doubling cascades. Either with or without spikes, chaos is no longer generated when the Ih is removed from the system. As the model is biologically plausible with biophysically meaningful parameters, we propose it as a useful tool to understand chaotic dynamics in neurons. PMID:28344550

  13. Characteristics of chloride currents activated by noradrenaline in rabbit ear artery cells.

    Science.gov (United States)

    Amédée, T; Large, W A; Wang, Q

    1990-09-01

    1. Responses to noradrenaline were studied in isolated rabbit ear artery cells with the nystatin method of whole-cell patch-clamp recording. With this technique it was possible to obtain reproducible responses to noradrenaline which was not possible with traditional whole-cell recording. 2. With NaCl as the major constituent of the bathing solution (potassium-free pipette and external solutions) the reversal potential (Er) of the noradrenaline-evoked current was about 0 mV. When external chloride was replaced by thiocyanate, iodide, nitrate and bromide, Er was shifted to more negative potentials which indicates that a chloride conductance increase contributes to the current activated by noradrenaline. 3. When sodium was substituted by Tris, N-methyl-D-glucamine, choline or barium, Er of the noradrenaline-evoked current did not alter. This result suggests that a cation conductance is not implicated in the response to noradrenaline recorded with the nystatin method of whole-cell recording. 4. The chloride current activated by noradrenaline was blocked by the selective alpha 1-adrenoceptor antagonist prazosin but was not affected by the alpha 2-adrenoceptor antagonist yohimbine. 5. When cells were exposed to zero calcium bathing solutions the amplitude of the current elicited by noradrenaline was unaffected when measured within 1-2 min in zero calcium conditions. Continued exposure to 0 Ca + 1 mM-EGTA solution reversibly abolished the chloride current to noradrenaline. 6. In the presence of caffeine, which releases Ca2+ from internal stores and itself induced an inward current (at a holding potential of -50 mV), noradrenaline did not elicit a current. These data suggest that the chloride current evoked by noradrenaline results from an increase in intracellular concentration of calcium derived from internal stores. 7. The chloride channel blocking agents 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS; 0.5 mM) and furosemide (0.5 mM) produced partial

  14. Development of Bottom Oil Recovery Systems. Revised

    Science.gov (United States)

    2014-02-01

    Athos I), open-ocean (T/V Prestige), and oil-field deep ocean drilling (Deepwater Horizon) related spills, the problems associated with tracking... mud . Probably the least sensitive bottom types are sand and mud bottoms in areas that already suffer from pollution such as industrial areas. Note...Capping Coral Reef Sea Grass Beds Kelp Forest Rocky Bottom Sand Mud Recommended Provisional Not Recommended Development of Bottom Oil Recovery Systems

  15. Long Wave Dynamics along a Convex Bottom

    CERN Document Server

    Didenkulova, Ira; Soomere, Tarmo

    2008-01-01

    Long linear wave transformation in the basin of varying depth is studied for a case of a convex bottom profile in the framework of one-dimensional shallow water equation. The existence of travelling wave solutions in this geometry and the uniqueness of this wave class is established through construction of a 1:1 transformation of the general 1D wave equation to the analogous wave equation with constant coefficients. The general solution of the Cauchy problem consists of two travelling waves propagating in opposite directions. It is found that generally a zone of a weak current is formed between these two waves. Waves are reflected from the coastline so that their profile is inverted with respect to the calm water surface. Long wave runup on a beach with this profile is studied for sine pulse, KdV soliton and N-wave. Shown is that in certain cases the runup height along the convex profile is considerably larger than for beaches with a linear slope. The analysis of wave reflection from the bottom containing a s...

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

    DEFF Research Database (Denmark)

    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 proposed...

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

    DEFF Research Database (Denmark)

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

    2002-01-01

    Neurotrophic factors yield neuroprotection by mechanisms that may be related to their effects as inhibitors of apoptosis as well as their effects on ion channels. The effect of ciliary neurotrophic factor (CNTF) on high-threshold voltage-activated Ca channels in cultured fetal mouse brain cortical...... neurones was investigated. Addition of CNTF into serum-free growth medium resulted in delayed reduction of the Ca2+ currents. The currents decreased to 50% after 4 h and stabilized at this level during incubation with CNTF for 48 h. Following removal of CNTF the inhibition was completely reversed after 18...

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Measurements of direct CP violating asymmetries in charmless decays of strange bottom mesons and bottom baryons.

    Science.gov (United States)

    Aaltonen, T; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Apresyan, A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bauer, G; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Brisuda, A; Bromberg, C; Brucken, E; Bucciantonio, M; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Dagenhart, D; d'Ascenzo, N; Datta, M; de Barbaro, P; De Cecco, S; De Lorenzo, G; Dell'orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, M; Dorigo, T; Ebina, K; Elagin, A; Eppig, A; Erbacher, R; Errede, D; Errede, S; Ershaidat, N; Eusebi, R; Fang, H C; Farrington, S; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Funakoshi, Y; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Halkiadakis, E; Hamaguchi, A; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hatakeyama, K; Hays, C; Heck, M; Heinrich, J; Herndon, M; Hewamanage, S; Hidas, D; Hocker, A; Hopkins, W; Horn, D; Hou, S; Hughes, R E; Hurwitz, M; Husemann, U; Hussain, N; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirby, M; Klimenko, S; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kuhr, T; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leo, S; Leone, S; Lewis, J D; Lin, C-J; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, Q; Liu, T; Lockwitz, S; Lockyer, N S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maeshima, K; Makhoul, K; Maksimovic, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Martínez, M; Martínez-Ballarín, R; Mastrandrea, P; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Potamianos, K; Poukhov, O; Prokoshin, F; Pronko, A; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Rescigno, M; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rubbo, F; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Sakurai, Y; Santi, L; Sartori, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M P; Schmitt, M

    2011-05-06

    We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb(-1) of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A(CP)(B(s)(0)→K(-)π(+))=+0.39±0.15(stat)±0.08(syst), and bottom baryons, A(CP)(Λ(b)(0)→pπ(-))=+0.03±0.17(stat)±0.05(syst) and A(CP)(Λ(b)(0)→pK(-))=+0.37±0.17(stat)±0.03(syst). In addition, we measure CP violation in B(0)→K(+)π(-) decays with 3.5σ significance, A(CP)(B(0)→K(+)π(-))=-0.086±0.023(stat)±0.009(syst), in agreement with the current world average. Measurements of branching fractions of B(s)(0)→K(+)K(-) and B(0)→π(+)π(-) decays are also updated.

  20. A method for treating bottom ash

    NARCIS (Netherlands)

    Rem, P.C.; Van Craaikamp, H.; Berkhout, S.P.M.; Sierhuis, W.; Van Kooy, L.A.

    2007-01-01

    A method for treating bottom ash from a waste incineration plant. The invention relates in particular to a method for treating bottom ash from a domestic waste incineration plant. In accordance with the invention bottom ash having a size ranging up to 2 mm is treated by removing a previously determi

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

    Institute of Scientific and Technical Information of China (English)

    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.

  2. Transcranial alternating current stimulation enhances individual alpha activity in human EEG.

    Directory of Open Access Journals (Sweden)

    Tino Zaehle

    Full Text Available Non-invasive electrical stimulation of the human cortex by means of transcranial direct current stimulation (tDCS has been instrumental in a number of important discoveries in the field of human cortical function and has become a well-established method for evaluating brain function in healthy human participants. Recently, transcranial alternating current stimulation (tACS has been introduced to directly modulate the ongoing rhythmic brain activity by the application of oscillatory currents on the human scalp. Until now the efficiency of tACS in modulating rhythmic brain activity has been indicated only by inference from perceptual and behavioural consequences of electrical stimulation. No direct electrophysiological evidence of tACS has been reported. We delivered tACS over the occipital cortex of 10 healthy participants to entrain the neuronal oscillatory activity in their individual alpha frequency range and compared results with those from a separate group of participants receiving sham stimulation. The tACS but not the sham stimulation elevated the endogenous alpha power in parieto-central electrodes of the electroencephalogram. Additionally, in a network of spiking neurons, we simulated how tACS can be affected even after the end of stimulation. The results show that spike-timing-dependent plasticity (STDP selectively modulates synapses depending on the resonance frequencies of the neural circuits that they belong to. Thus, tACS influences STDP which in turn results in aftereffects upon neural activity.The present findings are the first direct electrophysiological evidence of an interaction of tACS and ongoing oscillatory activity in the human cortex. The data demonstrate the ability of tACS to specifically modulate oscillatory brain activity and show its potential both at fostering knowledge on the functional significance of brain oscillations and for therapeutic application.

  3. Current control for a shunt hybrid active power filter using recursive integral PI

    Institute of Scientific and Technical Information of China (English)

    Wei ZHAO; An LUO; Ke PENG; Xia DENG

    2009-01-01

    This paper presents a current control method for a shunt hybrid active power filter(HAPF) using recursive integral Pl algorithm.The method improves the performance of the HAPF system by reducing the influence of detection accuracy,time delay of instruction current calculation and phase displacement of output filter.Fuzzy logic based set-point weighing algorithm is combined in the control scheme to enhance its robustness and anti-interference ability.The proposed algorithm is easy to implement for engineering applications and easy to compute.Experiment results have verified the validity of the proposed controller.Furthermore,the proposed recursive integral PI algorithm can also be applied in the control of periodic current as in AC drivers.

  4. Methods for Management of Innovation Activity Risks in the Current Conditions

    Directory of Open Access Journals (Sweden)

    Pysmak Viktoriia O.

    2016-03-01

    Full Text Available The article considers theoretical foundations of management of innovation activity risks. Relevance of the selected topic of research in connection with both volatile external environment and crisis developments in the country's economy has been substantiated. A semantic analysis of the concept of «risk» has been done, showing the presence of both positive and negative sides of risk situations. A scheme for enterprise management in the light of implementing innovation activity has been elaborated. An improved classification of innovation activity has been provided, creating the opportunity to focus on identifying risks in the process of allocating a specific direction of innovation activity. The main stages of identification and analysis of risks of innovation activity has been allocated. Methods for management of innovation activity risks in the current conditions have been developed. A concept of «system for management of innovation activity risks» has been formulated, its major features for enterprise has been outlined. The main requirements for a system for management of innovation activity risks have been allocated.

  5. Modulation of membrane currents and mechanical activity by niflumic acid in rat vascular smooth muscle.

    Science.gov (United States)

    Kirkup, A J; Edwards, G; Green, M E; Miller, M; Walker, S D; Weston, A H

    1996-12-12

    The effects of niflumic acid on whole-cell membrane currents and mechanical activity were examined in the rat portal vein. In freshly dispersed portal vein cells clamped at -60 mV in caesium (Cs+)-containing solutions, niflumic acid (1-100 microM) inhibited calcium (Ca2+)-activated chloride currents (IC1(Ca)) induced by caffeine (10 mM) and by noradrenaline (10 microM). In a potassium (K+)-containing solution and at a holding potential of - 10 mV, niflumic acid (10-100 microM) induced an outward K+ current (IK(ATP)) which was sensitive to glibenclamide (10-30 microM). At concentrations < 30 microM and at a holding potential of -2 mV, niflumic acid had no effect on the magnitude of the caffeine- or noradrenaline-stimulated current (IBK(Ca)) carried by the large conductance, Ca(2+)-sensitive K+ channel (BKCa). However, at a concentration of 100 microM, niflumic acid significantly inhibited IBK(Ca)) evoked by caffeine (10 mM) but not by NS1619 (1-(2'-hydroxy-5'-trifluoromethylphenyl)-5-trifluoromethyl-2(3 H) benzimidazolone; 20 microM). In Cs(+)-containing solutions, niflumic acid (10-100 microM) did not inhibit voltage-sensitive Ca2+ currents. In intact portal veins, niflumic acid (1-300 microM) inhibited spontaneous mechanical activity, an action which was partially antagonised by glibenclamide (1-10 microM), and contractions produced by noradrenaline (10 microM), an effect which was glibenclamide-insensitive. It is concluded that inhibition of ICl(Ca) and stimulation of IK(ATP) both contribute to the mechano-inhibitory actions of niflumic acid in the rat portal vein.

  6. Activation of protein kinase C inhibits potassium currents in cultured endothelial cells.

    Science.gov (United States)

    Zhang, H; Weir, B; Daniel, E E

    1995-04-01

    The effect of protein kinase C on potassium channels in cultured endothelial cells was investigated by using whole-cell patch-clamp techniques. Activation of protein kinase C by phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDBu), but not phorbol 12-monomyristate (PMM), an inactive analogue of phorbol esters, depressed an outward calcium-dependent potassium current. The inhibitory actions of PMA and PDBu could be reversed by the kinase inhibitor H-7. Cyclopiazonic acid, an inhibitor of the sarcoplasmic reticulum calcium pump, and LP-805, a novel vasodilator which also releases endothelium-derived relaxing factors, activated the outward calcium-dependent potassium conductance. PMA and PDBu, but not PMM, reduced the outward conductance induced by cyclopiazonic acid and LP-805. These effects of PMA and PDBu on potassium currents may be mediated either by phosphorylation of ion channels, or by decreasing intracellular calcium concentration.

  7. Development and Application of CDOS Series Catalysts for Bottoms Cracking

    Institute of Scientific and Technical Information of China (English)

    Wang Mingjin; Xu Mingde; Zhu Yuxia

    2013-01-01

    Development of CDOS catalyst for bottoms cracking is based on DOSY zeolite, which is characterized by high metal tolerance. The results of DOSY tests have shown that the catalyst has better activity retention at high metal content in the feed. The performance of catalyst tested in the bench scale was superior over that of the reference catalyst. The results of catalyst application have shown that the CDOS series catalysts have better bottoms cracking activity, high metal tolerance, excellent dry gas selectivity, and enhanced liquid yield.

  8. Control of spontaneous firing patterns by the selective coupling of calcium currents to calcium-activated potassium currents in striatal cholinergic interneurons.

    Science.gov (United States)

    Goldberg, Joshua A; Wilson, Charles J

    2005-11-02

    The spontaneous firing patterns of striatal cholinergic interneurons are sculpted by potassium currents that give rise to prominent afterhyperpolarizations (AHPs). Large-conductance calcium-activated potassium (BK) channel currents contribute to action potential (AP) repolarization; small-conductance calcium-activated potassium channel currents generate an apamin-sensitive medium AHP (mAHP) after each AP; and bursts of APs generate long-lasting slow AHPs (sAHPs) attributable to apamin-insensitive currents. Because all these currents are calcium dependent, we conducted voltage- and current-clamp whole-cell recordings while pharmacologically manipulating calcium channels of the plasma membrane and intracellular stores to determine what sources of calcium activate the currents underlying AP repolarization and the AHPs. The Cav2.2 (N-type) blocker omega-conotoxin GVIA (1 microM) was the only blocker that significantly reduced the mAHP, and it induced a transition to rhythmic bursting in one-third of the cells tested. Cav1 (L-type) blockers (10 microM dihydropyridines) were the only ones that significantly reduced the sAHP. When applied to cells induced to burst with apamin, dihydropyridines reduced the sAHPs and abolished bursting. Depletion of intracellular stores with 10 mM caffeine also significantly reduced the sAHP current and reversibly regularized firing. Application of 1 microM omega-conotoxin MVIIC (a Cav2.1/2.2 blocker) broadened APs but had a negligible effect on APs in cells in which BK channels were already blocked by submillimolar tetraethylammonium chloride, indicating that Cav2.1 (Q-type) channels provide the calcium to activate BK channels that repolarize the AP. Thus, calcium currents are selectively coupled to the calcium-dependent potassium currents underlying the AHPs, thereby creating mechanisms for control of the spontaneous firing patterns of these neurons.

  9. A Mathematical Model of Neonatal Rat Atrial Monolayers with Constitutively Active Acetylcholine-Mediated K+ Current.

    Science.gov (United States)

    Majumder, Rupamanjari; Jangsangthong, Wanchana; Feola, Iolanda; Ypey, Dirk L; Pijnappels, Daniël A; Panfilov, Alexander V

    2016-06-01

    Atrial fibrillation (AF) is the most frequent form of arrhythmia occurring in the industrialized world. Because of its complex nature, each identified form of AF requires specialized treatment. Thus, an in-depth understanding of the bases of these arrhythmias is essential for therapeutic development. A variety of experimental studies aimed at understanding the mechanisms of AF are performed using primary cultures of neonatal rat atrial cardiomyocytes (NRAMs). Previously, we have shown that the distinct advantage of NRAM cultures is that they allow standardized, systematic, robust re-entry induction in the presence of a constitutively-active acetylcholine-mediated K+ current (IKACh-c). Experimental studies dedicated to mechanistic explorations of AF, using these cultures, often use computer models for detailed electrophysiological investigations. However, currently, no mathematical model for NRAMs is available. Therefore, in the present study we propose the first model for the action potential (AP) of a NRAM with constitutively-active acetylcholine-mediated K+ current (IKACh-c). The descriptions of the ionic currents were based on patch-clamp data obtained from neonatal rats. Our monolayer model closely mimics the action potential duration (APD) restitution and conduction velocity (CV) restitution curves presented in our previous in vitro studies. In addition, the model reproduces the experimentally observed dynamics of spiral wave rotation, in the absence and in the presence of drug interventions, and in the presence of localized myofibroblast heterogeneities.

  10. Sedentary behaviour and physical activity in South Asian women: time to review current recommendations?

    Directory of Open Access Journals (Sweden)

    Indu Waidyatilaka

    Full Text Available OBJECTIVE: Our aims were to describe activity and sedentary behaviours in urban Asian women, with dysglycaemia (diagnosed at recruitment, and without dysglycaemia and examine the relative contribution of these parameters to their glycaemic status. METHODS: 2800 urban women (30-45 years were selected by random cluster sampling and screened for dysglycaemia for a final sample of 272 newly diagnosed, drug naive dysglycaemic and 345 normoglycaemic women. Physical activity and sedentary behaviours were assessed by the International Physical Activity Questionnaire (IPAQ. Demographic data, diet and anthropometry were recorded. Logistic regression analysis assessed contribution of all parameters to dysglycaemia and exposure attributable fractions were calculated. RESULTS: The mean energy expenditure on walking (2648.5±1023.7 MET-min/week and on moderate and vigorous physical activity (4342.3±1768.1 MET-min/week for normoglycemic women and dysglycaemic women (walking;1046.4±728.4 MET-min/week, moderate and vigorous physical activity; 1086.7±1184.4 MET-min/week was above the recommended amount of physical activity per week. 94.3% of women spent >1000 MET-minutes/week on activity. Mean sitting and TV time for normoglycaemic and dysglycaemic women were 154.3±62.8, 38.4±31.9, 312.6±116.7 and 140.2±56.5 minutes per day respectively. Physical activity and sedentary behaviour contributed to dysglycaemia after adjustment for family history, diet, systolic blood pressure and Body Mass Index. Exposure attributable fractions for dysglycaemia were; lower physical activity: 78%, higher waist circumference: 94%, and TV viewing time: 85%. CONCLUSIONS: Urban South Asian women are at risk of dysglycaemia at lower levels of sedentary behaviour and greater physical activity than western populations, indicating the need for re-visiting current physical activity guidelines for South Asians.

  11. Predictive current control of permanent magnet synchronous motor based on linear active disturbance rejection control

    Science.gov (United States)

    Li, Kunpeng

    2017-01-01

    The compatibility problem between rapidity and overshooting in the traditional predictive current control structure is inevitable and difficult to solve by reason of using PI controller. A novel predictive current control (PCC) algorithm for permanent magnet synchronous motor (PMSM) based on linear active disturbance rejection control (LADRC) is presented in this paper. In order to displace PI controller, the LADRC strategy which consisted of linear state error feedback (LSEF) control algorithm and linear extended state observer (LESO), is designed based on the mathematic model of PMSM. The purpose of LSEF is to make sure fast response to load mutation and system uncertainties, and LESO is designed to estimate the uncertain disturbances. The principal structures of the proposed system are speed outer loop based on LADRC and current inner loop based on predictive current control. Especially, the instruction value of qaxis current in inner loop is derived from the control quantity which is designed in speed outer loop. The simulation is carried out in Matlab/Simulink software, and the results illustrate that the dynamic and static performances of proposed system are satisfied. Moreover the robust against model parameters mismatch is enhanced obviously.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  14. An analytical model of capped turbulent oscillatory bottom boundary layers

    Science.gov (United States)

    Shimizu, Kenji

    2010-03-01

    An analytical model of capped turbulent oscillatory bottom boundary layers (BBLs) is proposed using eddy viscosity of a quadratic form. The common definition of friction velocity based on maximum bottom shear stress is found unsatisfactory for BBLs under rotating flows, and a possible extension based on turbulent kinetic energy balance is proposed. The model solutions show that the flow may slip at the top of the boundary layer due to capping by the water surface or stratification, reducing the bottom shear stress, and that the Earth's rotation induces current and bottom shear stress components perpendicular to the interior flow with a phase lag (or lead). Comparisons with field and numerical experiments indicate that the model predicts the essential characteristics of the velocity profiles, although the agreement is rather qualitative due to assumptions of quadratic eddy viscosity with time-independent friction velocity and a well-mixed boundary layer. On the other hand, the predicted linear friction coefficients, phase lead, and veering angle at the bottom agreed with available data with an error of 3%-10%, 5°-10°, and 5°-10°, respectively. As an application of the model, the friction coefficients are used to calculate e-folding decay distances of progressive internal waves with a semidiurnal frequency.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Somatostatinergic modulation of firing pattern and calcium-activated potassium currents in medium spiny neostriatal neurons.

    Science.gov (United States)

    Galarraga, E; Vilchis, C; Tkatch, T; Salgado, H; Tecuapetla, F; Perez-Rosello, T; Perez-Garci, E; Hernandez-Echeagaray, E; Surmeier, D J; Bargas, J

    2007-05-11

    Somatostatin is synthesized and released by aspiny GABAergic interneurons of the neostriatum, some of them identified as low threshold spike generating neurons (LTS-interneurons). These neurons make synaptic contacts with spiny neostriatal projection neurons. However, very few somatostatin actions on projection neurons have been described. The present work reports that somatostatin modulates the Ca(2+) activated K(+) currents (K(Ca) currents) expressed by projection cells. These actions contribute in designing the firing pattern of the spiny projection neuron; which is the output of the neostriatum. Small conductance (SK) and large conductance (BK) K(Ca) currents represent between 30% and 50% of the sustained outward current in spiny cells. Somatostatin reduces SK-type K(+) currents and at the same time enhances BK-type K(+) currents. This dual effect enhances the fast component of the after hyperpolarizing potential while reducing the slow component. Somatostatin then modifies the firing pattern of spiny neurons which changed from a tonic regular pattern to an interrupted "stuttering"-like pattern. Semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) tissue expression analysis of dorsal striatal somatostatinergic receptors (SSTR) mRNA revealed that all five SSTR mRNAs are present. However, single cell RT-PCR profiling suggests that the most probable receptor in charge of this modulation is the SSTR2 receptor. Interestingly, aspiny interneurons may exhibit a "stuttering"-like firing pattern. Therefore, somatostatin actions appear to be the entrainment of projection neurons to the rhythms generated by some interneurons. Somatostatin is then capable of modifying the processing and output of the neostriatum.

  17. A persistent sodium current contributes to oscillatory activity in heart interneurons of the medicinal leech.

    Science.gov (United States)

    Opdyke, C A; Calabrese, R L

    1994-12-01

    1. Normal activity in bilateral pairs of heart interneurons, from ganglia 3 or 4, in the medicinal leech (Hirudo medicinalis) is antiphasic due to their reciprocally inhibitory connections. However, Ca(++)-free Co(++)-containing salines lead to synchronous oscillations in these neurons. 2. Internal TEA+ allows expression of full plateaus during Co++ induced oscillations in heart interneurons; these plateaus are not blocked by Cs+. Similar plateaus are also observed with internal TEA+ alone, but under these conditions activity in heart interneurons from ganglia 3 or 4 is antiphasic. 3. Plateaus in heart interneurons induced by Co++ and internal TEA+ involve a conductance increase. 4. A voltage-dependent inward current, IP, showing little inactivation, was isolated using single-electrode voltage-clamp in heart interneurons. This current is carried at least in part by Na+; the current is reduced when external Na+ is reduced and is carried by Li++ when substituted for Na+. 5. Calcium channel blockers such as La3+ and Co++ block neither the TEA+ induced plateaus nor IP, suggesting that Na+ is not using Ca++ channels. Moreover, IP is enhanced by Ca(++)-free CO(++)-containing salines. Thus, IP is correlated with the TEA(+)- and Co(++)-induced plateau behavior.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. SIMULATION STUDY OF IMAGING OF UNDERWATER BOTTOM TOPOGRAPHY BY SYNTHETIC APERTURE RADAR

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Interaction between current and underwater bottom topography modulates roughness of the sea surface, which in turn yields variation of the radar scattering echo. By using the mechanism, this paper presents a simulation model for Synthetic Aperture Radar (SAR) imaging of underwater bottom topography. The numerical simulations experiments were made using the Princeton Ocean Model (POM) and analytical expression theory of SAR Image in Mischief sea area. It is concluded that the SAR image is better visual when water depth of underwater bottom topography is shallow or gradient of underwater bottom topography is high.

  20. A General Linear Wave Theory for Water Waves Propagating over Uneven Porous Bottoms

    Institute of Scientific and Technical Information of China (English)

    锁要红; 黄虎

    2004-01-01

    Starting from the widespread phenomena of porous bottoms in the near shore region, considering fully the diversity of bottom topography and wave number variation, and including the effect of evanescent modes, a general linear wave theory for water waves propagating over uneven porous bottoms in the near shore region is established by use of Green's second identity. This theory can be reduced to a number of the most typical mild-slope equations currently in use and provide a reliable research basis for follow-up development of nonlinear water wave theory involving porous bottoms.

  1. Modeling and stabilization results for a charge or current-actuated active constrained layer (ACL) beam model with the electrostatic assumption

    Science.gov (United States)

    Özer, Ahmet Özkan

    2016-04-01

    An infinite dimensional model for a three-layer active constrained layer (ACL) beam model, consisting of a piezoelectric elastic layer at the top and an elastic host layer at the bottom constraining a viscoelastic layer in the middle, is obtained for clamped-free boundary conditions by using a thorough variational approach. The Rao-Nakra thin compliant layer approximation is adopted to model the sandwich structure, and the electrostatic approach (magnetic effects are ignored) is assumed for the piezoelectric layer. Instead of the voltage actuation of the piezoelectric layer, the piezoelectric layer is proposed to be activated by a charge (or current) source. We show that, the closed-loop system with all mechanical feedback is shown to be uniformly exponentially stable. Our result is the outcome of the compact perturbation argument and a unique continuation result for the spectral problem which relies on the multipliers method. Finally, the modeling methodology of the paper is generalized to the multilayer ACL beams, and the uniform exponential stabilizability result is established analogously.

  2. Bottom-pressure observations of deep-sea internal hydrostatic and non-hydrostatic motions

    NARCIS (Netherlands)

    van Haren, H.

    2013-01-01

    In the ocean, sloping bottom topography is important for the generation and dissipation of internal waves. Here, the transition of such waves to turbulence is demonstrated using an accurate bottom-pressure sensor that was moored with an acoustic Doppler current profiler and high-resolution thermisto

  3. The nepheloid bottom layer and water masses at the shelf break of the western Ross Sea

    Science.gov (United States)

    Capello, Marco; Budillon, Giorgio; Cutroneo, Laura; Tucci, Sergio

    2009-06-01

    In the austral summers of 2000/2001 and 2002/2003 the Italian CLIMA Project carried out two oceanographic cruises along the northwestern margin of the Ross Sea, where the Antarctic Bottom Water forms. Here there is an interaction between the water masses on the sea floor of the outer shelf and slope with a consequent evolution of benthic nepheloid layers and an increase in total particulate matter. We observed three different situations: (a) the presence of triads (bottom structures characterized by a concomitant jump in turbidity, temperature, and salinity data) and high re-suspension phenomena related to the presence of the Circumpolar Deep Water and its mixing with cold, salty shelf waters associated with gravity currents; (b) the absence of triads with high re-suspension, implying that when the gravity currents are no longer active the benthic nepheloid layer may persist until the suspended particles settle to the sea floor, suggesting that the turbidity data can be used to study recent gravity current events; and (c) the absence of turbidity and sediment re-suspension phenomena supports the theory that a steady situation had been re-established and the current interaction no longer occurred or had finished sometime before.

  4. Bottom mounted seabed mooring frame for high current field

    Digital Repository Service at National Institute of Oceanography (India)

    AshokKumar, K.; Chandramohan, P.; Pednekar, P.S.; Diwan, S.G

    stream_size 48088 stream_content_type text/plain stream_name INCHOE_Proc_2004_2_812.pdf.txt stream_source_info INCHOE_Proc_2004_2_812.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 G56G49... G50 G51G114G100G32G73G110G100G105G97G110G32G78G97G116G105G111G110G97G108G32G67G111G110G102G101G114G101G110G99G101G32G111G110G32G72G97G114G98G111G117G114G32G38G32G79G99G101G97G110G32G69G110G103G105G110G101G101G114G105G110G103G44 G78G73G79G44G32G71G111...

  5. Dilution in a Dense Bottom Jet in Cross Currents

    DEFF Research Database (Denmark)

    Petersen, O.; Larsen, Torben

    1998-01-01

    A 3-dimensional numerical model describing the dilution in the near field around dense vertical jets in a cross flow is formulated and validated against laboratory experiments. The validation shows that the model reproduces the flow pattern well, though the dilution is underestimated by 20......%. The model is applied to a case study where the dilution from two vertical jets at an angle in shallow water is described. It is demonstrated that a 20% increase in dilution is possible. It is concluded that the model may become a valuable tool in diffusor design....

  6. Combined Wave and Current Bottom Boundary Layers: A Review

    Science.gov (United States)

    2016-03-01

    formation during an energetic storm. They noted that the sedi- ment first became dilated due to water entrainment, followed by erosion during the most...suggested by Businger et al. (1971), who developed their eddy viscosity for thermally stratified atmospheric boundary layers, was shown to be valid for

  7. Dilution in a Dense Bottom Jet in Cross Currents

    DEFF Research Database (Denmark)

    Petersen, O.; Larsen, Torben

    1998-01-01

    A 3-dimensional numerical model describing the dilution in the near field around dense vertical jets in a cross flow is formulated and validated against laboratory experiments. The validation shows that the model reproduces the flow pattern well, though the dilution is underestimated by 20%. The ......%. The model is applied to a case study where the dilution from two vertical jets at an angle in shallow water is described. It is demonstrated that a 20% increase in dilution is possible. It is concluded that the model may become a valuable tool in diffusor design....

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

    Science.gov (United States)

    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.

  9. Hysteresis Current Control Based Shunt Active Power Filter for Six Pulse Ac/Dc Converter

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Pandey

    2017-02-01

    Full Text Available In this paper the simulation of Shunt Active power Filter using P-Q theory and PI controller has been presented. This SAPF compensates the harmonic currents drawn by three phase six pulse AC/DC converter. The process of compensation is done by calculating the instantaneous reactive power losses using p-q theory and the PI controller to reduce the ripple voltage of the dc capacitor of the PWM-VSI. This approach is different from conventional approach and provides very effective solution. In this simulation we use hysteresis band current controller (HCC for switching the VSI inverter. The simulation has been done for both steady state and transient conditions

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

    CERN Document Server

    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...

  11. Role of persistent sodium current in bursting activity of mouse neocortical networks in vitro.

    Science.gov (United States)

    van Drongelen, Wim; Koch, Henner; Elsen, Frank P; Lee, Hyong C; Mrejeru, Ana; Doren, Erin; Marcuccilli, Charles J; Hereld, Mark; Stevens, Rick L; Ramirez, Jan-Marino

    2006-11-01

    Most types of electrographic epileptiform activity can be characterized by isolated or repetitive bursts in brain electrical activity. This observation is our motivation to determine mechanisms that underlie bursting behavior of neuronal networks. Here we show that the persistent sodium (Na(P)) current in mouse neocortical slices is associated with cellular bursting and our data suggest that these cells are capable of driving networks into a bursting state. This conclusion is supported by the following observations. 1) Both low concentrations of tetrodotoxin (TTX) and riluzole reduce and eventually stop network bursting while they simultaneously abolish intrinsic bursting properties and sensitivity levels to electrical stimulation in individual intrinsically bursting cells. 2) The sensitivity levels of regular spiking neurons are not significantly affected by riluzole or TTX at the termination of network bursting. 3) Propagation of cellular bursting in a neuronal network depended on excitatory connectivity and disappeared on bath application of CNQX (20 microM) + CPP (10 microM). 4) Voltage-clamp measurements show that riluzole (20 microM) and very low concentrations of TTX (50 nM) attenuate Na(P) currents in the neural membrane within a 1-min interval after bath application of the drug. 5) Recordings of synaptic activity demonstrate that riluzole at this concentration does not affect synaptic properties. 6) Simulations with a neocortical network model including different types of pyramidal cells, inhibitory interneurons, neurons with and without Na(P) currents, and recurrent excitation confirm the essence of our experimental observations that Na(P) conductance can be a critical factor sustaining slow population bursting.

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

    Directory of Open Access Journals (Sweden)

    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

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

    DEFF Research Database (Denmark)

    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...... 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...

  14. Bottom-linked innovation: Collaboration between middle managers and employees

    DEFF Research Database (Denmark)

    Kristensen, Catharina Juul

    2017-01-01

    Employee-driven innovation is gaining ground as a strategy for developing sustainable organisations in the public and private sector. This type of innovation is characterised by active employee participation, and the bottom-up perspective is often emphasised. This article explores an issue that has...

  15. Pronase acutely modifies high voltage-activated calcium currents and cell properties of Lymnaea neurons.

    Science.gov (United States)

    Hermann, P M; Lukowiak, K; Wildering, W C; Bulloch, A G

    1997-12-01

    Pronase E ('pronase') is one of the proteolytic enzymes that are used in preparative procedures such as cell isolation and to soften the sheath of invertebrate ganglia. Although several effects of proteolytic enzymes on the physiology of non-neuronal tissues have been described, the effects of these enzymes on central neurons have received little attention. We examined the effects of bath-applied pronase on neurons in the Lymnaea central nervous system and in vitro. Pronase caused action potential broadening in neurons that exhibit a shoulder on the repolarization phase of their action potentials. This effect of pronase was accompanied by, although unrelated to, a depolarization and decrease in action potential interval. Some, but not all, effects of pronase in the central nervous system were reversible. For example, the decreases in membrane potential and action potential interval were both reversed after approximately 1 h of washing with saline. However, the effect of pronase on the action potential duration was not reversed after a period of 90 min. The modulation of action potential width prompted us to examine Ca2+ currents. Exposure to pronase resulted in an increase in both peak and late high voltage-activated Ca2+ currents in isolated neurons. Pronase neither changed the inactivation rate nor caused a shift in the current-voltage relationship of the current. The changes in action potential duration could be prevented by application of 0.1 mM Cd2+, indicating that the action potential broadening caused by pronase depends on Ca2+ influx. This is the first systematic study of the acute and direct actions of pronase on Ca2+ currents and cell properties both in the CNS and in vitro.

  16. What are the implications of rapid global warming for landslide-triggered turbidity current activity?

    Science.gov (United States)

    Clare, Michael; Peter, Talling; James, Hunt

    2014-05-01

    A geologically short-lived (~170kyr) episode of global warming occurred at ~55Ma, termed the Initial Eocene Thermal Maximum (IETM). Global temperatures rose by up to 8oC over only ~10kyr and a massive perturbation of the global carbon cycle occurred; creating a negative carbon isotopic (~-4% δ13C) excursion in sedimentary records. This interval has relevance to study of future climate change and its influence on geohazards including submarine landslides and turbidity currents. We analyse the recurrence frequency of turbidity currents, potentially initiated from large-volume slope failures. The study focuses on two sedimentary intervals that straddle the IETM and we discuss implications for turbidity current triggering. We present the results of statistical analyses (regression, generalised linear model, and proportional hazards model) for extensive turbidite records from an outcrop at Zumaia in NE Spain (N=285; 54.0 to 56.5 Ma) and based on ODP site 1068 on the Iberian Margin (N=1571; 48.2 to 67.6 Ma). The sedimentary sequences provide clear differentiation between hemipelagic and turbiditic mud with only negligible evidence of erosion. We infer dates for turbidites by converting hemipelagic bed thicknesses to time using interval-averaged accumulation rates. Multi-proxy dating techniques provide good age constraint. The background trend for the Zumaia record shows a near-exponential distribution of turbidite recurrence intervals, while the Iberian Margin shows a log-normal response. This is interpreted to be related to regional time-independence (exponential) and the effects of additive processes (log-normal). We discuss how a log-normal response may actually be generated over geological timescales from multiple shorter periods of random turbidite recurrence. The IETM interval shows a dramatic departure from both these background trends, however. This is marked by prolonged hiatuses (0.1 and 0.6 Myr duration) in turbidity current activity in contrast to the

  17. An overview of current activities at the National Solar Thermal Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, C.P.; Klimas, P.C.

    1992-01-01

    This paper is a description of the United States Department of Energy's National Solar Thermal Test Facility, highlighting current test programs. In the central receiver area, research underway supports commercialization of molten nitrate salt technology, including receivers, thermal energy transport, and corrosion experiments. Concentrator research includes large-area, glass-metal heliostats and stretched-membrane heliostats and dishes. Test activities in support of dish-Stirling systems with reflux receivers are described. Research on parabolic troughs includes characterization of several receiver configurations. Other test facility activities include solar detoxification experiments, design assistance testing of commercially-available solar hardware, and non-DOE-funded work, including thermal exposure tests and. testing of volumetric and PV central receiver concepts.

  18. An overview of current activities at the National Solar Thermal Test Facility

    Science.gov (United States)

    Cameron, C. P.; Klimas, P. C.

    This paper is a description of the United States Department of Energy's National Solar Thermal Test Facility, highlighting current test programs. In the central receiver area, research underway supports commercialization of molten nitrate salt technology, including receivers, thermal energy transport, and corrosion experiments. Concentrator research includes large-area, glass-metal heliostats and stretched-membrane heliostats and dishes. Test activities in support of dish-Stirling systems with reflux receivers are described. Research on parabolic troughs includes characterization of several receiver configurations. Other test facility activities include solar detoxification experiments, design assistance testing of commercially-available solar hardware, and non-DOE-funded work, including thermal exposure tests and testing of volumetric and PV central receiver concepts.

  19. An overview of current activities at the National Solar Thermal Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, C.P.; Klimas, P.C.

    1992-10-01

    This paper is a description of the United States Department of Energy`s National Solar Thermal Test Facility, highlighting current test programs. In the central receiver area, research underway supports commercialization of molten nitrate salt technology, including receivers, thermal energy transport, and corrosion experiments. Concentrator research includes large-area, glass-metal heliostats and stretched-membrane heliostats and dishes. Test activities in support of dish-Stirling systems with reflux receivers are described. Research on parabolic troughs includes characterization of several receiver configurations. Other test facility activities include solar detoxification experiments, design assistance testing of commercially-available solar hardware, and non-DOE-funded work, including thermal exposure tests and. testing of volumetric and PV central receiver concepts.

  20. A plea for Global Health Action bottom-up

    Directory of Open Access Journals (Sweden)

    Ulrich Laaser

    2016-10-01

    Full Text Available This opinion piece focuses on global health action by hands-on bottom-up practice: Initiation of an organizational framework and securing financial efficiency are – however - essential, both clearly a domain of well trained public health professionals. Examples of action are cited in the four main areas of global threats: planetary climate change, global divides and inequity, global insecurity and violent conflicts, global instability and financial crises. In conclusion a stable health systems policy framework would greatly enhance success. However, such organisational framework dries out if not linked to public debates channelling fresh thoughts and controversial proposals: the structural stabilisation is essential but has to serve not to dominate bottom-up activities. In other words a horizontal management is required, a balanced equilibrium between bottom-up initiative and top-down support. Last not least rewarding voluntary and charity work by public acknowledgement is essential.

  1. The activity intensities reached when playing active tennis gaming relative to sedentary gaming, tennis game-play, and current activity recommendations in young adults.

    Science.gov (United States)

    Scanlan, Aaron T; Arkinstall, Hayley; Dalbo, Vincent J; Humphries, Brendan J; Jennings, Cameron T; Kingsley, Michael I C

    2013-09-01

    Although active gaming is popular and can increase energy expenditure in young adults, its efficacy as a prescriptive exercise tool is not well understood. This study aimed to: (a) compare the activity intensities experienced by young adults while playing active tennis gaming with conventional sedentary gaming, tennis game-play, and current activity recommendations for health; and (b) identify changes in activity intensities across playing time. After habitualization, 10 active young adults (age: 20.2 ± 0.4 years; stature: 1.74 ± 0.03 m; body mass: 67.7 ± 3.3 kg) completed 3 experimental trials (sedentary gaming, active tennis gaming, and tennis game-play) on separate days in a randomized order. Heart rate (HR) and metabolic equivalents (METs) were averaged across 5 minutes and 10 minutes intervals, and the entire 20 minutes bout within each condition. Active gaming produced greater intensities across 5-10, 10-15, and 15-20 minutes time intervals compared with sedentary gaming (p Tennis game-play elicited greater HR (67 ± 5% HR(max)) and METs (5.0 ± 0.2) responses than both sedentary (40 ± 2% HR(max), 1.1 ± 0.1 METs) and active gaming (45 ± 2% HR(max), 1.4 ± 0.1 METs) (p tennis game-play produced activity intensities meeting current recommendations for health benefit. Lower HR intensities were reached across 0-5 minutes than during later time intervals during active gaming (6%) and tennis game-play (9%) (p tennis game-play and insufficient to contribute toward promoting and maintaining good health in young adults. These data suggest that active tennis gaming should not be recommended by exercise professionals as a substitute for actual sports participation in young adults.

  2. Review of current activities to model and measure the orbital debris environment in low-earth orbit

    Science.gov (United States)

    Reynolds, R. C.

    A very active orbital debris program is currently being pursued at the NASA/Johnson Space Center (JSC), with projects designed to better define the current environment, to project future environments, to model the processes contributing to or constraining the growth of debris in the environment, and to gather supporting data needed to improve the understanding of the orbital debris problem and the hazard it presents to spacecraft. This paper is a review of the activity being conducted at JSC, by NASA, Lockheed Engineering and Sciences Company, and other support contractors, and presents a review of current activity, results of current research, and a discussion of directions for future development.

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

    Science.gov (United States)

    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.

  4. A hyperpolarization-activated inward current alters swim frequency of the pteropod mollusk Clione limacina.

    Science.gov (United States)

    Pirtle, Thomas J; Willingham, Kyle; Satterlie, Richard A

    2010-12-01

    The pteropod mollusk, Clione limacina, exhibits behaviorally relevant swim speed changes that occur within the context of the animal's ecology. Modulation of C. limacina swimming speed involves changes that occur at the network and cellular levels. Intracellular recordings from interneurons of the swim central pattern generator show the presence of a sag potential that is indicative of the hyperpolarization-activated inward current (I(h)). Here we provide evidence that I(h) in primary swim interneurons plays a role in C. limacina swimming speed control and may be a modulatory target. Recordings from central pattern generator swim interneurons show that hyperpolarizing current injection produces a sag potential that lasts for the duration of the hyperpolarization, a characteristic of cells possessing I(h). Following the hyperpolarizing current injection, swim interneurons also exhibit postinhibitory rebound (PIR). Serotonin enhances the sag potential of C. limacina swim interneurons while the I(h) blocker, ZD7288, reduces the sag potential. Furthermore, a negative correlation was found between the amplitude of the sag potential and latency to PIR. Because latency to PIR was previously shown to influence swimming speed, we hypothesize that I(h) has an effect on swimming speed. The I(h) blocker, ZD7288, suppresses swimming in C. limacina and inhibits serotonin-induced acceleration, evidence that supports our hypothesis.

  5. Hyperpolarization-activated current (I(h in ganglion-cell photoreceptors.

    Directory of Open Access Journals (Sweden)

    Matthew J Van Hook

    Full Text Available Intrinsically photosensitive retinal ganglion cells (ipRGCs express the photopigment melanopsin and serve as the primary retinal drivers of non-image-forming visual functions such as circadian photoentrainment, the pupillary light reflex, and suppression of melatonin production in the pineal. Past electrophysiological studies of these cells have focused on their intrinsic photosensitivity and synaptic inputs. Much less is known about their voltage-gated channels and how these might shape their output to non-image-forming visual centers. Here, we show that rat ipRGCs retrolabeled from the suprachiasmatic nucleus (SCN express a hyperpolarization-activated inwardly-rectifying current (I(h. This current is blocked by the known I(h blockers ZD7288 and extracellular cesium. As in other systems, including other retinal ganglion cells, I(h in ipRGCs is characterized by slow kinetics and a slightly greater permeability for K(+ than for Na(+. Unlike in other systems, however, I(h in ipRGCs apparently does not actively contribute to resting membrane potential. We also explore non-specific effects of the common I(h blocker ZD7288 on rebound depolarization and evoked spiking and discuss possible functional roles of I(h in non-image-forming vision. This study is the first to characterize I(h in a well-defined population of retinal ganglion cells, namely SCN-projecting ipRGCs.

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

    Science.gov (United States)

    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.

  7. Nitric oxide activates leak K+ currents in the presumed cholinergic neuron of basal forebrain.

    Science.gov (United States)

    Kang, Youngnam; Dempo, Yoshie; Ohashi, Atsuko; Saito, Mitsuru; Toyoda, Hiroki; Sato, Hajime; Koshino, Hisashi; Maeda, Yoshinobu; Hirai, Toshihiro

    2007-12-01

    Learning and memory are critically dependent on basal forebrain cholinergic (BFC) neuron excitability, which is modulated profoundly by leak K(+) channels. Many neuromodulators closing leak K(+) channels have been reported, whereas their endogenous opener remained unknown. We here demonstrate that nitric oxide (NO) can be the endogenous opener of leak K(+) channels in the presumed BFC neurons. Bath application of 1 mM S-nitroso-N-acetylpenicillamine (SNAP), an NO donor, induced a long-lasting hyperpolarization, which was often interrupted by a transient depolarization. Soluble guanylyl cyclase inhibitors prevented SNAP from inducing hyperpolarization but allowed SNAP to cause depolarization, whereas bath application of 0.2 mM 8-bromoguanosine-3',5'-cyclomonophosphate (8-Br-cGMP) induced a similar long-lasting hyperpolarization alone. These observations indicate that the SNAP-induced hyperpolarization and depolarization are mediated by the cGMP-dependent and -independent processes, respectively. When examined with the ramp command pulse applied at -70 mV under the voltage-clamp condition, 8-Br-cGMP application induced the outward current that reversed at K(+) equilibrium potential (E(K)) and displayed Goldman-Hodgkin-Katz rectification, indicating the involvement of voltage-independent K(+) current. By contrast, SNAP application in the presumed BFC neurons either dialyzed with the GTP-free internal solution or in the presence of 10 muM Rp-8-bromo-beta-phenyl-1,N(2)-ethenoguanosine 3',5'-cyclic monophosphorothioate sodium salt, a protein kinase G (PKG) inhibitor, induced the inward current that reversed at potentials much more negative than E(K) and close to the reversal potential of Na(+)-K(+) pump current. These observations strongly suggest that NO activates leak K(+) channels through cGMP-PKG-dependent pathway to markedly decrease the excitability in BFC neurons, while NO simultaneously causes depolarization by the inhibition of Na(+)-K(+) pump through ATP

  8. Area-intensive bottom culture production of blue mussels, Mytilus edulis (L.)

    DEFF Research Database (Denmark)

    Christensen, Helle Torp

    it is therefore necessary to focus on area-intensive production methods for mussel exploitation. For that purpose bottom culture production of blue mussels is relevant. Despite a long tradition for bottom culturing in Europe the method is still de-pendent on natural conditions, such as recruitment, food...... insights in biological mechanisms can be used as a tool to develop and optimize bottom culture production methods. The study was addressed through the following questions: 1) How can the seed mussel source in bottom culturing be supported? 2) How can survival of mussels in bottom culturing be improved...... column have the potential to become an alternative seed source for mussel production in bottom cultures. When compared to mussels collected from natural benthic mussel beds, suspended mussels had an active predator response by developing a significantly stronger attach-ment to the substrate and having...

  9. Perceptual learning: top to bottom.

    Science.gov (United States)

    Amitay, Sygal; Zhang, Yu-Xuan; Jones, Pete R; Moore, David R

    2014-06-01

    Perceptual learning has traditionally been portrayed as a bottom-up phenomenon that improves encoding or decoding of the trained stimulus. Cognitive skills such as attention and memory are thought to drive, guide and modulate learning but are, with notable exceptions, not generally considered to undergo changes themselves as a result of training with simple perceptual tasks. Moreover, shifts in threshold are interpreted as shifts in perceptual sensitivity, with no consideration for non-sensory factors (such as response bias) that may contribute to these changes. Accumulating evidence from our own research and others shows that perceptual learning is a conglomeration of effects, with training-induced changes ranging from the lowest (noise reduction in the phase locking of auditory signals) to the highest (working memory capacity) level of processing, and includes contributions from non-sensory factors that affect decision making even on a "simple" auditory task such as frequency discrimination. We discuss our emerging view of learning as a process that increases the signal-to-noise ratio associated with perceptual tasks by tackling noise sources and inefficiencies that cause performance bottlenecks, and present some implications for training populations other than young, smart, attentive and highly-motivated college students.

  10. RyR2 modulates a Ca2+-activated K+ current in mouse cardiac myocytes.

    Directory of Open Access Journals (Sweden)

    Yong-Hui Mu

    Full Text Available In cardiomyocytes, Ca2+ entry through voltage-dependent Ca2+ channels (VDCCs binds to and activates RyR2 channels, resulting in subsequent Ca2+ release from the sarcoplasmic reticulum (SR and cardiac contraction. Previous research has documented the molecular coupling of small-conductance Ca2+-activated K+ channels (SK channels to VDCCs in mouse cardiac muscle. Little is known regarding the role of RyRs-sensitive Ca2+ release in the SK channels in cardiac muscle. In this study, using whole-cell patch clamp techniques, we observed that a Ca2+-activated K+ current (IK,Ca recorded from isolated adult C57B/L mouse atrial myocytes was significantly decreased by ryanodine, an inhibitor of ryanodine receptor type 2 (RyR2, or by the co-application of ryanodine and thapsigargin, an inhibitor of the sarcoplasmic reticulum calcium ATPase (SERCA (p<0.05, p<0.01, respectively. The activation of RyR2 by caffeine increased the IK,Ca in the cardiac cells (p<0.05, p<0.01, respectively. We further analyzed the effect of RyR2 knockdown on IK,Ca and Ca2+ in isolated adult mouse cardiomyocytes using a whole-cell patch clamp technique and confocal imaging. RyR2 knockdown in mouse atrial cells transduced with lentivirus-mediated small hairpin interference RNA (shRNA exhibited a significant decrease in IK,Ca (p<0.05 and [Ca2+]i fluorescence intensity (p<0.01. An immunoprecipitated complex of SK2 and RyR2 was identified in native cardiac tissue by co-immunoprecipitation assays. Our findings indicate that RyR2-mediated Ca2+ release is responsible for the activation and modulation of SK channels in cardiac myocytes.

  11. Arbuscular mycorrhizal symbiosis and active ingredients of medicinal plants: current research status and prospectives.

    Science.gov (United States)

    Zeng, Yan; Guo, Lan-Ping; Chen, Bao-Dong; Hao, Zhi-Peng; Wang, Ji-Yong; Huang, Lu-Qi; Yang, Guang; Cui, Xiu-Ming; Yang, Li; Wu, Zhao-Xiang; Chen, Mei-Lan; Zhang, Yan

    2013-05-01

    Medicinal plants have been used world-wide for thousands of years and are widely recognized as having high healing but minor toxic side effects. The scarcity and increasing demand for medicinal plants and their products have promoted the development of artificial cultivation of medicinal plants. Currently, one of the prominent issues in medicinal cultivation systems is the unstable quality of the products. Arbuscular mycorrhiza (AM) affects secondary metabolism and the production of active ingredients of medicinal plants and thus influence the quality of herbal medicines. In this review, we have assembled, analyzed, and summarized the effects of AM symbioses on secondary metabolites of medicinal plants. We conclude that symbiosis of AM is conducive to favorable characteristics of medicinal plants, by improving the production and accumulation of important active ingredients of medicinal plants such as terpenes, phenols, and alkaloids, optimizing the composition of different active ingredients in medicinal plants and ultimately improving the quality of herbal materials. We are convinced that the AM symbiosis will benefit the cultivation of medicinal plants and improve the total yield and quality of herbal materials. Through this review, we hope to draw attention to the status and prospects of, and arouse more interest in, the research field of medicinal plants and mycorrhiza.

  12. Transcranial Direct Current Stimulation Modulates Neurogenesis and Microglia Activation in the Mouse Brain

    Directory of Open Access Journals (Sweden)

    Anton Pikhovych

    2016-01-01

    Full Text Available Transcranial direct current stimulation (tDCS has been suggested as an adjuvant tool to promote recovery of function after stroke, but the mechanisms of its action to date remain poorly understood. Moreover, studies aimed at unraveling those mechanisms have essentially been limited to the rat, where tDCS activates resident microglia as well as endogenous neural stem cells. Here we studied the effects of tDCS on microglia activation and neurogenesis in the mouse brain. Male wild-type mice were subjected to multisession tDCS of either anodal or cathodal polarity; sham-stimulated mice served as control. Activated microglia in the cerebral cortex and neuroblasts generated in the subventricular zone as the major neural stem cell niche were assessed immunohistochemically. Multisession tDCS at a sublesional charge density led to a polarity-dependent downregulation of the constitutive expression of Iba1 by microglia in the mouse cortex. In contrast, both anodal and, to an even greater extent, cathodal tDCS induced neurogenesis from the subventricular zone. Data suggest that tDCS elicits its action through multifacetted mechanisms, including immunomodulation and neurogenesis, and thus support the idea of using tDCS to induce regeneration and to promote recovery of function. Furthermore, data suggest that the effects of tDCS may be animal- and polarity-specific.

  13. Measurements of Direct CP Violating Asymmetries in Charmless Decays of Strange Bottom Mesons and Bottom Baryons

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, T.; Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U. /Dubna, JINR

    2011-03-01

    We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb{sup -1} of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A{sub CP}(B{sub s}{sup 0} {yields} K{sup -}{pi}{sup +}) = +0.39 {+-} 0.15 (stat) {+-} 0.08 (syst), and botton baryons, A{sub CP}({Lambda}{sub b}{sup 0} {yields} p{pi}{sup -}) = + 0.03 {+-} 0.17 (stat) {+-} 0.05 (syst) and A{sub CP} ({Lambda}{sub b}{sup 0} {yields} pK{sup -}) = +0.37 {+-} 0.17 (stat) {+-} 0.03 (syst). In addition, they measure CP violation in B{sup 0} {yields} K{sup +}{pi}{sup -} decays with 3.5{sigma} significance, A{sub CP} (B{sup 0} {yields} K{sup +}{pi}{sup -}) = -0.086 {+-} 0.023 (stat) {+-} 0.009 (syst), in agreement with the current world average. Measurements of branching fractions of B{sub s}{sup 0} {yields} K{sup +}K{sup -} and B{sup 0} {yields} {pi}{sup +}{pi}{sup -} decays are also updated.

  14. Spintronics in the «Bottom-up» Approach

    Directory of Open Access Journals (Sweden)

    Yu.A. Kruglyak

    2014-11-01

    Full Text Available Basic topics of spintronics such as spin valve, interface resistance due to the mismatch of conduction modes, spin potentials, non-local spin voltage, spin moment and its transport, Landau-Lifshitz-Gilbert equation, and explanation on its basis why a magnet has an “easy axis”, nanomagnet dynamics by spin current, polarizers and analyzers of spin current, diffusion equation for ballistic transport and current in terms of non-equilibrium potentials are discussed in the frame of the “bottom-up” approach of modern nanoelectronics.

  15. Wet physical separation of MSWI bottom ash

    NARCIS (Netherlands)

    Muchova, L.

    2010-01-01

    Bottom ash (BA) from municipal solid waste incineration (MSWI) has high potential for the recovery of valuable secondary materials. For example, the MSWI bottom ash produced by the incinerator at Amsterdam contains materials such as non-ferrous metals (2.3%), ferrous metals (8-13%), gold (0.4 ppm),

  16. Development of Castables for Gass Tank Bottom

    Institute of Scientific and Technical Information of China (English)

    YUANLin; CHENShengling

    1998-01-01

    The production and use of zircon corundum refractory castables were analyzed.The superior properties and applied effect of castables for glass tank bottom were demonstrated.The results show that those castables have excellent molten glass corrosion resistance (MGCR) and enable glass tank bot-tom to form a seal mass.

  17. Development of Crashworthy Bottom and Side Structures

    DEFF Research Database (Denmark)

    Naar, H.; Kujala, P.; Simonsen, Bo Cerup;

    2002-01-01

    structures. The first structure is a conventional double bottom. In the second structure (presently protected through a patent) the bottom plating is stiffened with hat-profiles instead of bulb profiles. In the third structure the outer shell is an all-steel sandwich panel. In the fourth structure the bottom......The purpose of this work is to compare the resistance to damage of various types of double bottom structures in a stranding event. The results can also be interpreted as the crashworthiness of side structures penetrated by a striking vessel in a collision event. The comparative analyses are made...... by use of a commercial, explicit finite element program. The ship bottom is loaded with a conical indenter with a rounded tip, which is forced laterally into the structures in different positions. The aim is to compare resistance forces, energy absorption and penetration to fracture for four different...

  18. The oscillations of ship lock bottom

    Directory of Open Access Journals (Sweden)

    N.Yu. Kuzmin

    2012-06-01

    Full Text Available The article deals with the dynamic characteristics of the ship lock. The accurate design relations intended to study the natural and forced vibrations of the bottom of the ship lock are provided. The degree of filling of the lock, as well as the added mass of water is considered. The various coupling conditions of the bottom and walls of buildings are taken into account. A concrete example of the calculation is given.An exact, in the framework of the adopted design scheme, solution of the problem of the own and forced vibrations of the bottom of the ship lock is found. The frequency of the first five tones of vibrations and the associated mass of liquid according to thickness of the structure and coupling conditions of the bottom and sides of the lock are analyzed. A significant effect of liquids on low-frequency part of the spectrum and the dynamic response of the bottom is determined.

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

    Directory of Open Access Journals (Sweden)

    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. A role of stretch-activated potassium currents in the regulation of uterine smooth muscle contraction

    Institute of Scientific and Technical Information of China (English)

    Iain L O BUXTON; Nathanael HEYMAN; Yi-ying WU; Scott BARNETT; Craig ULRICH

    2011-01-01

    Rates of premature birth are alarming and threaten societies and healthcare systems worldwide. Premature labor results in premature birth in over 50% of cases. Preterm birth accounts for three-quarters of infant morbidity and mortality. Children that survive birth before 34 weeks gestation often face life-long disability. Current treatments for preterm labor are wanting. No treatment has been found to be generally effective and none are systematically evaluated beyond 48 h. New approaches to the treatment of preterm labor are desperately needed. Recent studies from our laboratory suggest that the uterine muscle is a unique compartment with regulation of uterine relaxation unlike that of other smooth muscles. Here we discuss recent evidence that the mechanically activated 2-pore potassium channel, TREK-1, may contribute to contraction-relaxation signaling in uterine smooth muscle and that TREK-1 gene variants associated with human labor and preterm labor may lead to a better understanding of preterm labor and its possible prevention.

  1. 76 FR 31342 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2011-05-31

    ... Collection; Comment Request; Current Good Manufacturing Practice Regulations for Finished Pharmaceuticals... Current Good Manufacturing Practice (CGMP) Regulations for Finished Pharmaceuticals. DATES: Submit either... of information technology. Current Good Manufacturing Practice Regulations for...

  2. 75 FR 40840 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2010-07-14

    ... Collection; Comment Request; Current Good Manufacturing Practice in Manufacturing, Packaging, Labeling, or... information collection provisions of FDA's regulations regarding current good manufacturing practice (CGMP... appropriate, and other forms of information technology. Current Good Manufacturing Practice in......

  3. 78 FR 17215 - Agency Information Collection Activities: Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2013-03-20

    ... Collection; Comment Request; Current Good Manufacturing Practice for Positron Emission Tomography Drugs... regulations on current good manufacturing practice (CGMP) for positron emission tomography (PET) drugs. DATES... of information technology. Current Good Manufacturing Practice for Positron Emission Tomography...

  4. 75 FR 73101 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2010-11-29

    ... Collection; Comment Request; Current Good Manufacturing Practice Regulations for Medicated Feeds AGENCY: Food... appropriate, and other forms of information technology. Current Good Manufacturing Practice Regulations for... current good manufacturing practice (cGMP) regulations for drugs, including medicated feeds....

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

    Science.gov (United States)

    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

  6. Cutaneous retinal activation and neural entrainment in transcranial alternating current stimulation: A systematic review.

    Science.gov (United States)

    Schutter, Dennis J L G

    2016-10-15

    Transcranial alternating current stimulation (tACS) applies exogenous oscillatory electric field potentials to entrain neural rhythms and is used to investigate brain-function relationships and its potential to enhance perceptual and cognitive performance. However, due to current spread tACS can cause cutaneous activation of the retina and phosphenes. Several lines of evidence suggest that retinal phosphenes are capable of inducing neural entrainment, making the contributions of central and peripheral stimulation to the effects in the brain difficult to disentangle. In this literature review, the importance of this issue is further illustrated by the fact that photic stimulation can have a direct impact on perceptual and cognitive performance. This leaves open the possibility that peripheral photic stimulation can at least in part explain the central effects that are attributed to tACS. The extent to which phosphene perception contributes to the effects of exogenous oscillatory electric fields in the brain and influence perception and cognitive performance needs to be examined to understand the working mechanisms of tACS in neurophysiology and behaviour.

  7. A monovalent ion-selective cation current activated by noradrenaline in smooth muscle cells of rabbit ear artery.

    Science.gov (United States)

    Wang, Q; Hogg, R C; Large, W A

    1993-04-01

    Membrane currents were recorded with the perforated-patch method with a low-chloride (35 mM) pipette solution in isolated smooth muscle cells of the rabbit ear artery. At a holding potential of -50 mV in potassium-free conditions spontaneous inward single-channel currents were observed and noradrenaline evoked a noisy inward current, which appeared to be comprised of the spontaneous currents. The reversal potential (Vr) of the spontaneous channel and noradrenaline-induced current was not affected in anion-substitution experiments but Vr was altered when external Na+ was replaced with choline or TRIS. The relationship between clamp potential and spontaneous single-channel current amplitude was linear and the mean unitary conductance was 28 pS. Caffeine, which releases calcium from the sarcoplasmic reticulum, and the calcium ionophore ionomycin activated the cation current and also blocked the response to noradrenaline. Spontaneous channel current activity and the noradrenaline-induced current were blocked when external NaCl was replaced with 89 mM CaCl2. The response to noradrenaline was blocked by prazosin but was not affected by yohimbine and therefore the response is mediated by alpha 1-adrenoceptors. It is concluded that in rabbit ear artery smooth muscle cells there is a calcium-activated cation channel of 28 pS conductance, which is relatively impermeable to calcium but can be activated by noradrenaline.

  8. Transcranial direct current stimulation improves ipsilateral selective muscle activation in a frequency dependent manner.

    Directory of Open Access Journals (Sweden)

    Kazumasa Uehara

    Full Text Available Failure to suppress antagonist muscles can lead to movement dysfunction, such as the abnormal muscle synergies often seen in the upper limb after stroke. A neurophysiological surrogate of upper limb synergies, the selectivity ratio (SR, can be determined from the ratio of biceps brachii (BB motor evoked potentials to transcranial magnetic stimulation prior to forearm pronation versus elbow flexion. Surprisingly, cathodal transcranial direct current stimulation (c-TDCS over ipsilateral primary motor cortex (M1 reduces (i.e. improves the SR in healthy adults, and chronic stroke patients. The ability to suppress antagonist muscles may be exacerbated at high movement rates. The aim of the present study was to investigate whether the selective muscle activation of the biceps brachii (BB is dependent on altering frequency demands, and whether the c-tDCS improvement of SR is dependent on task frequency. Seventeen healthy participants performed repetitive isometric elbow flexion and forearm pronation at three rates, before and after c-tDCS or sham delivered to ipsilateral left M1. Ipsilateral c-tDCS improved the SR in a frequency dependent manner by selectively suppressing BB antagonist excitability. Our findings confirm that c-tDCS is an effective tool for improving selective muscle activation, and provide novel evidence for its efficacy at rates of movement where it is most likely to benefit task performance.

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

    Science.gov (United States)

    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.

  10. Implementation of an active instructional design for teaching the concepts of current, voltage and resistance

    Science.gov (United States)

    Orlaineta-Agüero, S.; Del Sol-Fernández, S.; Sánchez-Guzmán, D.; García-Salcedo, R.

    2017-01-01

    In the present work we show the implementation of a learning sequence based on an active learning methodology for teaching Physics, this proposal tends to promote a better learning in high school students with the use of a comic book and it combines the use of different low-cost experimental activities for teaching the electrical concepts of Current, Resistance and Voltage. We consider that this kind of strategy can be easily extrapolated to higher-education levels like Engineering-college/university level and other disciplines of Science. To evaluate this proposal, we used some conceptual questions from the Electric Circuits Concept Evaluation survey developed by Sokoloff and the results from this survey was analysed with the Normalized Conceptual Gain proposed by Hake and the Concentration Factor that was proposed by Bao and Redish, to identify the effectiveness of the methodology and the models that the students presented after and before the instruction, respectively. We found that this methodology was more effective than only the implementation of traditional lectures, we consider that these results cannot be generalized but gave us the opportunity to view many important approaches in Physics Education; finally, we will continue to apply the same experiment with more students, in the same and upper levels of education, to confirm and validate the effectiveness of this methodology proposal.

  11. A current model of neural circuitry active in forming mental images.

    Science.gov (United States)

    Brodziak, Andrzej

    2013-12-12

    My aim here is to formulate a compact, intuitively understandable model of neural circuits active in imagination that would be consistent with the current state of knowledge, but that would be simple enough to be able to use for teaching. I argue that such a model should be based on the recent idea of "concept neurons" and circuits of 2 separate loops necessary for recalling mental images and consolidation of memory traces of long-term memory. This paper discusses the role of the hippocampus and temporal lobe, emphasizing the essential importance of recurrent pathways and oscillations occurring in the upper layers of hierarchical neural structures, as well as oscillations in thalamo-cortical loops. The elaborated model helps explain specific processes such as imagining future situations, novel objects, and anticipated action, as well as imagination concerning oneself, which is indispensable for the sense of identity and self-awareness. I attempt to present this compact, simple model of neural circuitry active in imagination by using some intuitive, demonstrative figures.

  12. Bottom-up assembly of metallic germanium.

    Science.gov (United States)

    Scappucci, Giordano; Klesse, Wolfgang M; Yeoh, LaReine A; Carter, Damien J; Warschkow, Oliver; Marks, Nigel A; Jaeger, David L; Capellini, Giovanni; Simmons, Michelle Y; Hamilton, Alexander R

    2015-08-10

    Extending chip performance beyond current limits of miniaturisation requires new materials and functionalities that integrate well with the silicon platform. Germanium fits these requirements and has been proposed as a high-mobility channel material, a light emitting medium in silicon-integrated lasers, and a plasmonic conductor for bio-sensing. Common to these diverse applications is the need for homogeneous, high electron densities in three-dimensions (3D). Here we use a bottom-up approach to demonstrate the 3D assembly of atomically sharp doping profiles in germanium by a repeated stacking of two-dimensional (2D) high-density phosphorus layers. This produces high-density (10(19) to 10(20) cm(-3)) low-resistivity (10(-4)Ω · cm) metallic germanium of precisely defined thickness, beyond the capabilities of diffusion-based doping technologies. We demonstrate that free electrons from distinct 2D dopant layers coalesce into a homogeneous 3D conductor using anisotropic quantum interference measurements, atom probe tomography, and density functional theory.

  13. To the Bottom of the Sbottom

    CERN Document Server

    Han, Tao; Wu, Yongcheng; Zhang, Bin; Zhang, Huanian

    2015-01-01

    In the search for bottom squark (sbottom) in SUSY at the LHC, the common practice has been to assume a $100\\%$ decay branching fraction for a given search channel. In realistic MSSM scenarios, there are often more than one significant decay modes to be present, which significantly weaken the current sbottom search limits at the LHC. On the other hand, the combination of the multiple decay modes offers alternative discovery channels for sbottom searches. In this paper, we present the sbottom decays in a few representative mass parameter scenarios. We then analyze the sbottom signal for the pair production in QCD with one sbottom decaying via $\\tilde{b}\\rightarrow b \\chi_1^0,\\ b \\chi_2^0$, and the other one decaying via $\\tilde{b} \\rightarrow t \\chi_1^\\pm$. With the gaugino subsequent decaying to gauge bosons or a Higgs boson $\\chi_2^0 \\rightarrow Z \\chi_1^0,\\ h \\chi_1^0$ and $\\chi_1^\\pm \\rightarrow W^\\pm \\chi_1^0$, we study the reach of those signals at the 14 TeV LHC with 300 ${\\rm fb^{-1}}$ integrated lumino...

  14. CHARACTERISTICS OF SLUDGE BOTTOM MESH

    Directory of Open Access Journals (Sweden)

    Kamil Szydłowski

    2016-05-01

    Full Text Available The main aim of the study was to assess the selected heavy metals pollution of bottom sediments of small water bodies of different catchment management. Two ponds located in Mostkowo village were chosen for investigation. The first small water reservoir is surrounded by the cereal fields, cultivated without the use of organic and mineral fertilizers (NPK. The second reservoir is located in a park near rural buildings. Sediment samples were collected by the usage of KC Denmark sediments core probe. Samples were taken from 4 layers of sediment, from depth: 0–5, 5–10, 10–20 and 20–30 cm. Sampling was made once during the winter period (2014 year when ice occurred on the surface of small water bodies, from three points. The material was prepared for further analysis according to procedures used in soil science. The content of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn were determined by atomic absorption spectrometry by usage of ASA ICE 3000 Thermo Scientific after prior digestion in the mixture (5: 1 of concentrated acids (HNO3 and HClO4. Higher pH values ​​were characteristic for sediments of pond located in a park than in pond located within the agricultural fields. In both small water bodies the highest heavy metal concentrations occurred in the deepest points of the research. In the sediments of the pond located within crop fields the highest concentration of cadmium, copper, lead and zinc were observed in a layer of 0–5 cm, wherein the nickel and chromium in a layer of 20–30 cm. In the sediments of the pond, located in the park the highest values ​​occurred at the deepest sampling point in the layer taken form 10–20 cm. Sediments from second reservoir were characterized by the largest average concentrations of heavy metals, except the lead content in sediment form the layer of 10–20 cm. According to the geochemical evaluation of sediments proposed by Bojakowska and Sokołowska [1998], the majority of samples belongs to Ist

  15. Tsunami Energy, Ocean-Bottom Pressure, and Hydrodynamic Force from Stochastic Bottom Displacement

    Science.gov (United States)

    Ramadan, Khaled T.; Omar, M. A.; Allam, Allam A.

    2017-03-01

    Tsunami generation and propagation due to a randomly fluctuating of submarine earthquake modeled by vertical time-dependent of a stochastic bottom displacement are investigated. The increase in oscillations and amplitude in the free surface elevation are controlled by the noise intensity parameter of the stochastic bottom displacement. Evolution of kinetic and potential energy of the resulting waves by the stochastic bottom displacement is examined. Exchange between potential and kinetic energy was achieved in the propagation process. The dynamic ocean-bottom pressure during tsunami generation is investigated. As the vertical displacement of the stochastic bottom increases, the peak amplitude of the ocean-bottom pressure increases through the dynamic effect. Time series of the maximum tsunami wave amplitude, kinetic and potential energy, wave and ocean-bottom pressure gauges and the hydrodynamic force caused by the stochastic source model under the effect of the water depth of the ocean are investigated.

  16. Pipeline bottoming cycle study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    The technical and economic feasibility of applying bottoming cycles to the prime movers that drive the compressors of natural gas pipelines was studied. These bottoming cycles convert some of the waste heat from the exhaust gas of the prime movers into shaft power and conserve gas. Three typical compressor station sites were selected, each on a different pipeline. Although the prime movers were different, they were similar enough in exhaust gas flow rate and temperature that a single bottoming cycle system could be designed, with some modifications, for all three sites. Preliminary design included selection of the bottoming cycle working fluid, optimization of the cycle, and design of the components, such as turbine, vapor generator and condensers. Installation drawings were made and hardware and installation costs were estimated. The results of the economic assessment of retrofitting bottoming cycle systems on the three selected sites indicated that profitability was strongly dependent upon the site-specific installation costs, how the energy was used and the yearly utilization of the apparatus. The study indicated that the bottoming cycles are a competitive investment alternative for certain applications for the pipeline industry. Bottoming cycles are technically feasible. It was concluded that proper design and operating practices would reduce the environmental and safety hazards to acceptable levels. The amount of gas that could be saved through the year 2000 by the adoption of bottoming cycles for two different supply projections was estimated as from 0.296 trillion ft/sup 3/ for a low supply projection to 0.734 trillion ft/sup 3/ for a high supply projection. The potential market for bottoming cycle equipment for the two supply projections varied from 170 to 500 units of varying size. Finally, a demonstration program plan was developed.

  17. From Nose to Brain: Un-Sensed Electrical Currents Applied in the Nose Alter Activity in Deep Brain Structures

    OpenAIRE

    Weiss, Tali; Shushan, Sagit; Ravia, Aharon; Hahamy, Avital; Secundo, Lavi; Weissbrod, Aharon; Ben-Yakov, Aya; Holtzman, Yael; Cohen-Atsmoni, Smadar; Roth, Yehudah; Sobel, Noam

    2016-01-01

    Rules linking patterns of olfactory receptor neuron activation in the nose to activity patterns in the brain and ensuing odor perception remain poorly understood. Artificially stimulating olfactory neurons with electrical currents and measuring ensuing perception may uncover these rules. We therefore inserted an electrode into the nose of 50 human volunteers and applied various currents for about an hour in each case. This induced assorted non-olfactory sensations but never once the perceptio...

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

    Science.gov (United States)

    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.

  19. Evaluation of nitrofurantoin activity against the urinary isolates in the current scenario of antimicrobial resistance

    Directory of Open Access Journals (Sweden)

    Rajkumar Manojkumar Singh

    2015-01-01

    Full Text Available Introduction: Urinary tract infections (UTIs caused by antibiotic-resistant isolates have become a major health hazard in recent years as they are very difficult to treat, causing an increase in morbidity and mortality. Nitrofurantoin has been used successfully for decades for the prophylaxis and treatment of uncomplicated cystitis but the increased emergence of antibiotic resistance has made nitrofurantoin a suitable candidate for the treatment of UTI caused by multidrug-resistant pathogens. This study was taken up with the aim to determine the activity of nitrofurantoin against the wide range of resistant urinary gram-negative and gram-positive isolates. Materials and Methods: A total of 440 nonduplicate, gram-negative, and gram-positive uropathogens obtained between July 2013 and December 2014 from 3,780 fresh midstream urine samples were subjected to the VITEK-2 compact system for identification and antimicrobial susceptibility testing. Phenotypic methods for the detection of different beta-lactamases [extended spectrum beta-lactamases, AmpC beta-lactamases, metallo-beta-lactamases, and inhibitor-resistant beta-lactamases (IRT] and methicillin-resistance staphylococci [methicillin-resistant Staphylococcus aureus (MRSA and methicillin-resistant coagulase-negative staphylococci (MRCNS] were employed. Results: High activity of nitrofurantoin was observed against MRCNS (96% followed by MRSA (95%, extended spectrum beta-lactamases (ESBLs (70%, IRT (66%, and vancomycin-resistant enterococci (VRE (66%. However, the sensitivity rate was lowered to 38% and 32% for metallo-beta-lactamases (MBLs and AmpC beta-lactamases, respectively. Conclusion: In view of the current incidence of antibiotic resistance among community uropathogens and based on efficacy, cost-effectiveness, and low impact on promoting resistance, nitrofurantoin should be considered as a reasonable alternative to trimethoprim-sulfamethoxazole (TMP-SMX and fluoroquinolones for the first

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

    DEFF Research Database (Denmark)

    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...... and current source density analysis to study real-time Ca(2+) dynamics and transmembrane ionic currents in relation to CMRO(2) in the mouse cerebellar cortex in vivo. We report a direct correlation between CMRO(2) and summed (i.e., the sum of excitatory, negative currents during the whole stimulation period...

  1. What a drag: Quantifying the global impact of chronic bottom trawling on continental shelf sediment

    Science.gov (United States)

    Oberle, Ferdinand K.J.; Storlazzi, Curt; Hanebuth, Till J.J.

    2016-01-01

    Continental shelves worldwide are subject to intense bottom trawling that causes sediment to be resuspended. The widely used traditional concepts of modern sedimentary transport systems on the shelf rely only on estimates for naturally driven sediment resuspension such as through storm waves, bottom currents, and gravity-driven flows but they overlook a critical anthropogenic factor. The strong influence of bottom trawling on a source-to-sink sediment budget is explored on the NW Iberian shelf. Use of Automated Information System vessel tracking data provides for a high-resolution vessel track reconstruction and the accurate calculation of the spatial distribution of bottom trawling intensity and associated resuspended sediment load. The mean bottom trawling-induced resuspended sediment mass for the NW Iberian shelf is 13.50 Mt yr− 1, which leads to a six-fold increase in off-shelf sediment transport when compared to natural resuspension mechanisms. The source-to-sink budget analysis provides evidence that bottom trawling causes a rapid erosion of the fine sediment on human time scales. Combining global soft sediment distribution data of the shelves with worldwide bottom trawling intensity estimates we show that the bottom trawling-induced resuspended sediment mass amounts to approximately the same mass of all sediment entering the shelves through rivers. Spatial delineations between natural and anthropogenic sediment resuspension areas are presented to aid in marine management questions.

  2. What a drag: Quantifying the global impact of chronic bottom trawling on continental shelf sediment

    Science.gov (United States)

    Oberle, Ferdinand K. J.; Storlazzi, Curt D.; Hanebuth, Till J. J.

    2016-07-01

    Continental shelves worldwide are subject to intense bottom trawling that causes sediment to be resuspended. The widely used traditional concepts of modern sedimentary transport systems on the shelf rely only on estimates for naturally driven sediment resuspension such as through storm waves, bottom currents, and gravity-driven flows but they overlook a critical anthropogenic factor. The strong influence of bottom trawling on a source-to-sink sediment budget is explored on the NW Iberian shelf. Use of Automated Information System vessel tracking data provides for a high-resolution vessel track reconstruction and the accurate calculation of the spatial distribution of bottom trawling intensity and associated resuspended sediment load. The mean bottom trawling-induced resuspended sediment mass for the NW Iberian shelf is 13.50 Mt yr- 1, which leads to a six-fold increase in off-shelf sediment transport when compared to natural resuspension mechanisms. The source-to-sink budget analysis provides evidence that bottom trawling causes a rapid erosion of the fine sediment on human time scales. Combining global soft sediment distribution data of the shelves with worldwide bottom trawling intensity estimates we show that the bottom trawling-induced resuspended sediment mass amounts to approximately the same mass of all sediment entering the shelves through rivers. Spatial delineations between natural and anthropogenic sediment resuspension areas are presented to aid in marine management questions.

  3. Momentum balance in the shallow water equations on bottom discontinuities

    Science.gov (United States)

    Valiani, A.; Caleffi, V.

    2017-02-01

    This work investigates the topical problem of balancing the shallow water equations over bottom steps of different heights. The current approaches in the literature are essentially based on mathematical analysis of the hyperbolic system of balance equations and take into account the relevant progresses in treating the non-conservative form of the governing system in the framework of path-conservative schemes. An important problem under debate is the correct position of the momentum balance closure when the bottom elevation is discontinuous. Cases of technical interest are systematically analysed, consisting of backward-facing steps and forward-facing steps, tackled supercritical and subcritical flows; critical (sonic) conditions are also analysed and discussed. The fundamental concept governing the problem and supported by the present computations is that the energy-conserving approach is the only approach that is consistent with the classical shallow water equations formulated with geometrical source terms and that the momentum balance is properly closed if a proper choice of a conventional depth on the bottom step is performed. The depth on the step is shown to be included between the depths just upstream and just downstream of the step. It is also shown that current choices (as given in the literature) of the depth on (or in front of) the step can lead to unphysical configurations, similar to some energy-increasing solutions.

  4. Landfilling: Bottom Lining and Leachate Collection

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Manfredi, Simone; Kjeldsen, Peter

    2011-01-01

    , whether composed of soils or geosynthetic barriers, are able to prevent leachate emission to the environment for a relatively long time (50 years or longer), it should be realized that no liner is 100% efficient. However, modern lining systems, which include composite liners and multiple (double, or even......The critical element of a landfill, which is essential for the protection of the environment in general, and prevention of contamination of the underlying soils and groundwater in particular, is the bottom lining system. The major focus of the bottom lining system development is to prevent leachate......, as well as the migration of landfill gas, preventing contact between gas and groundwater. The bottom lining system is composed of a relatively impermeable liner or lining system. This very low hydraulic conductivity system controls the movement of the leachate out of the landfill. The bottom lining system...

  5. Modulating activity in the orbitofrontal cortex changes trustees' cooperation: A transcranial direct current stimulation study.

    Science.gov (United States)

    Wang, Guangrong; Li, Jianbiao; Yin, Xile; Li, Shuaiqi; Wei, Mengxing

    2016-04-15

    Trust is one of the most important factors in human society, as it pervades almost all domains of the society. The trusting behavior of trustors is dependent on the belief about the cooperative (reciprocal) level of trustees. Thence what are the motives underlying the cooperative behavior? An important explanation is that guilt aversion can motivate cooperative behavior. The right orbitofrontal cortex (OFC) is the guilt-specific region, while there is little understanding on the causal effect of this network. We explored the causal effect of the OFC on cooperative behavior using transcranial direct current stimulation (tDCS). Sixty participants played the trust game as trustees, and they received either anodal tDCS over the right OFC and simultaneously cathodal electrode over the right dorsolateral prefrontal cortex (DLPFC), or sham stimulation. Experimental results showed that participants as trustees transferred back more money in the tDCS treatment than sham stimulation. This suggests that the activity of the right OFC has causal effects on cooperative behavior.

  6. [Current situation and measures to promote anti-doping activities in Japan].

    Science.gov (United States)

    Asakawa, Shin

    2011-01-01

    After the Ministry of Edcation, Culture, Sports, Science and Technology of Japan has ratified the UNESCO "International Convention Fight against Doping in Sport" in December 2006, the government increased its support to Anti-Doping activities. About 5 years ago, the total number of doping control samples a year in Japan was around 2000, and this number was not enough to demonstrate Japanese athletes' cleanness to the rest of the world. However, after the government's ratification of the UNESCO international convention, the government increased its support both financially and politically. By receiving the increased support from the government, testing number has increased and reached 5000 samples a year. 5 years ago, our target athletes range was only international level athletes who compete in the Olympics or international events. As we expanded our testing numbers, the target range of the athletes was also expanded and national level athletes also became our targets. As a result, athletes without having adequate knowledge about anti-doping regulations became our target. This situation caused inadvertent anti-doping rule violation cases. Most of those anti-doping rule violations were the result of taking over-the-counter medicines, etc. In order to cope with those inadvertent anti-doping rule violation problems, we, Japan Anti-Doping Agency launched "Sport Pharmacist Project" in cooperation with Japan Pharmaceutical Association. In this project, we provide anti-doping information/regulation to the pharmacists and make those pharmacists knowledgeable about the current anti-doping rules and regulations.

  7. Modulation of physiological mirror activity with transcranial direct current stimulation over dorsal premotor cortex.

    Science.gov (United States)

    Beaulé, Vincent; Tremblay, Sara; Lafleur, Louis-Philippe; Ferland, Marie C; Lepage, Jean-François; Théoret, Hugo

    2016-11-01

    Humans have a natural tendency towards symmetrical movements, which rely on a distributed cortical network that allows for complex unimanual movements. Studies on healthy humans using rTMS have shown that disruption of this network, and particularly the dorsal premotor cortex (dPMC), can result in increased physiological mirror movements. The aim of the present set of experiments was to further investigate the role of dPMC in restricting motor output to the contralateral hand and determine whether physiological mirror movements could be decreased in healthy individuals. Physiological mirror movements were assessed before and after transcranial direct current stimulation (tDCS) over right and left dPMC in three conditions: bilateral, unilateral left and unilateral right stimulation. Mirror EMG activity was assessed immediately before, 0, 10 and 20 min after tDCS. Results show that physiological mirroring increased significantly in the hand ipsilateral to cathodal stimulation during bilateral stimulation of the dPMC, 10 and 20 min after stimulation compared to baseline. There was no significant modulation of physiological mirroring in the hand ipsilateral to anodal stimulation in the bilateral condition or following unilateral anodal or unilateral cathodal stimulation. The present data further implicate the dPMC in the control of unimanual hand movements and show that physiological mirroring can be increased but not decreased with dPMC tDCS.

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

    Directory of Open Access Journals (Sweden)

    Salvatore Grasso, Yoshio Sakka and Giovanni Maizza

    2009-01-01

    Full Text Available 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 was pioneered by Bloxam (1906 GB Patent No. 9020 who developed the first resistive sintering apparatus. The patents were searched by keywords or by cross-links and were withdrawn from the Japanese Patent Office (342 patents, the United States Patent and Trademark Office (175 patents, the Chinese State Intellectual Property Office of P.R.C. (69 patents and the World Intellectual Property Organization (12 patents. A subset of 119 (out of 642 ECAS patents on methods and apparatuses was selected and described in detail with respect to their fundamental concepts, physical principles and importance in either present ECAS apparatuses or future ECAS technologies for enhancing efficiency, reliability, repeatability, controllability and productivity. The paper is divided into two parts, the first deals with the basic concepts, features and definitions of basic ECAS and the second analyzes the auxiliary devices/peripherals. The basic ECAS is classified with reference to discharge time (fast and ultrafast ECAS. The fundamental principles and definitions of ECAS are outlined in accordance with the scientific and patent literature.

  9. TOPICAL REVIEW: Electric current activated/assisted sintering (ECAS): a review of patents 1906-2008

    Science.gov (United States)

    Grasso, Salvatore; Sakka, Yoshio; Maizza, Giovanni

    2009-10-01

    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 was pioneered by Bloxam (1906 GB Patent No. 9020) who developed the first resistive sintering apparatus. The patents were searched by keywords or by cross-links and were withdrawn from the Japanese Patent Office (342 patents), the United States Patent and Trademark Office (175 patents), the Chinese State Intellectual Property Office of P.R.C. (69 patents) and the World Intellectual Property Organization (12 patents). A subset of 119 (out of 642) ECAS patents on methods and apparatuses was selected and described in detail with respect to their fundamental concepts, physical principles and importance in either present ECAS apparatuses or future ECAS technologies for enhancing efficiency, reliability, repeatability, controllability and productivity. The paper is divided into two parts, the first deals with the basic concepts, features and definitions of basic ECAS and the second analyzes the auxiliary devices/peripherals. The basic ECAS is classified with reference to discharge time (fast and ultrafast ECAS). The fundamental principles and definitions of ECAS are outlined in accordance with the scientific and patent literature.

  10. Cytotoxicity, Bactericidal, and Antioxidant Activity of Sodium Alginate Hydrosols Treated with Direct Electric Current

    Directory of Open Access Journals (Sweden)

    Żaneta Król

    2017-03-01

    Full Text Available The aim of the study was to investigate the effect of using direct electric current (DC of 0, 200, and 400 mA for five minutes on the physiochemical properties, cytotoxicity, antibacterial, and antioxidant activity of sodium alginate hydrosols with different sodium chloride concentrations. The pH, oxidation-reduction potential (ORP, electrical conductivity (EC, and available chlorine concentration (ACC were measured. The effect of sodium alginate hydrosols treated with DC on Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Micrococcus luteus, Escherichia coli, Salmonella enteritidis, Yersinia enterocolitica, Pseudomonas fluorescence, and RAW 264.7 and L929 cells was investigated. Subsequently, the antioxidant properties of hydrosols were evaluated by determining the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH and ferric reducing antioxidant power (FRAP. The results have shown that after applying 400 mA in hydrosol samples with 0.1% and 0.2% NaCl all tested bacteria were inactivated. The ACC concentration of C400 samples with NaCl was equal to 13.95 and 19.71 mg/L, respectively. The cytotoxicity analysis revealed that optimized electric field conditions and the addition of sodium chloride allow for the avoidance of toxicity effects on normal cells without disturbing the antibacterial effects. Due to the presence of oxidizing substances, the DPPH of variants treated with DC was lower than the DPPH of control samples.

  11. How Service Innovation Boosts Bottom Lines

    Directory of Open Access Journals (Sweden)

    Claude Legrand

    2013-09-01

    Full Text Available In the national quest for ground-breaking R&D discoveries and inventions, service innovation is frequently ignored at considerable cost to an organization’s bottom line and a nation’s productivity. For the fact is that innovation applied systematically to all activities outside of R&D can make the difference between uninspiring results and substantial growth in every sector. Many countries, in particular in Europe, have recognized the importance of service innovation and are devoting considerable resources to research, the capture of best practices, and the measurement of progress and success. Given the physiognomy of the modern economy, it does not make sense for leaders in the Canadian public sector to devote all available innovation investment dollars to science and technology R&D. This article explores why service innovation is not yet a priority on the innovation agenda in Canada and why we should correct the dangerous misconception that there is just one “innovation gap” that needs to be addressed. It provides practical recommendations that public and private sector leaders can use to take advantage of this under-valued, high-potential innovation opportunity and calls for the creation of a national service innovation resource to support enterprises of all sizes as a means to improve Canadian productivity.

  12. 75 FR 72827 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2010-11-26

    ... Collection; Comment Request; Current Good Manufacturing Practice Regulations for Type A Medicated Articles... appropriate, and other forms of information technology. Current Good Manufacturing Practice Regulations for... authority to issue current good manufacturing practice (cGMP) regulations for drugs, including type...

  13. Implementing collaborative improvement - top-down, bottom-up or both?

    DEFF Research Database (Denmark)

    Kaltoft, Rasmus; Boer, Harry; Caniato, Federico

    2007-01-01

    , the study identifies three different implementation approaches. The bottom-up learning-by-doing approach starts at a practical level, with simple improvement activities, and aims at gradually developing a wide range of CoI knowledge, skills and initiatives. The top-down directive approach starts......The research presented in this article was aimed at increasing the current understanding of the process of developing Collaborative Improvement (CoI) in Extended Manufacturing Enterprises (EME). Based on action research in three EMEs involving a total of 13 companies from five European countries...... with aligning the partners' CoI objectives and an assessment of their collaboration and CoI maturity in order to provide a common platform before actually starting improvement activities. The laissez-faire approach builds on shared goals/vision, meetings on equal terms and joint work, in a non-directive and non...

  14. Principle and Control Design of Active Ground-Fault Arc Suppression Device for Full Compensation of Ground Current

    DEFF Research Database (Denmark)

    Wang, Wen; Zeng, Xiangjun; Yan, Lingjie;

    2017-01-01

    Traditional ground-fault arc suppression devices mainly deal with capacitive component of ground current and have weak effect on the active and harmonic ones, which limits the arc suppression performance. The capacitive current detection needed in them suffers from low accuracy and robustness....... The commonly-used large-capacity reactive component may bring about overvoltage because of possible resonance with the distributed phase-to-ground capacitance. To solve these problems, an active ground-fault arc suppression device is presented. It employs a topology based on single-phase inverter to inject...... current into the neutral without any large-capacity reactors, and thus avoids the aforementioned overvoltage. It compensates all the active, reactive and harmonic components of the ground current to reliably extinguish the ground-fault arcs. A dual-loop voltage control method is proposed to realize arc...

  15. Numerical tsunami modeling and the bottom relief

    Science.gov (United States)

    Kulikov, E. A.; Gusiakov, V. K.; Ivanova, A. A.; Baranov, B. V.

    2016-11-01

    The effect of the quality of bathymetric data on the accuracy of tsunami-wave field calculation is considered. A review of the history of the numerical tsunami modeling development is presented. Particular emphasis is made on the World Ocean bottom models. It is shown that the modern digital bathymetry maps, for example, GEBCO, do not adequately simulate the sea bottom in numerical models of wave propagation, leading to considerable errors in estimating the maximum tsunami run-ups on the coast.

  16. Bottom Interaction in Ocean Acoustic Propagation

    Science.gov (United States)

    2015-09-30

    to thousands of kilometers in the deep ocean where the sound channel is not bottom limited. The specific goal is to study the role of bottom...They are barely observable when the ambient noise and PE predicted arrivals are loud (such as in the sound 2 channel), but become the dominant...obvious seafloor feature. Figures 2 to 5 show maps of the transmission locations that excite BDSRs. Essentially no BDSR arrivals are observed on the

  17. Vector-like bottom quarks in composite Higgs models

    DEFF Research Database (Denmark)

    Gillioz, M.; Grober, R.; Kapuvari, A.;

    2014-01-01

    Like many other models, Composite Higgs Models feature the existence of heavy vector-like quarks. Mixing effects between the Standard Model fields and the heavy states, which can be quite large in case of the top quark, imply deviations from the SM. In this work we investigate the possibility...... of heavy bottom partners. We show that they can have a significant impact on electroweak precision observables and the current Higgs results if there is a sizeable mixing with the bottom quark. We explicitly check that the constraints from the measurement of the CKM matrix element V-tb are fulfilled...... be applied to other models with similar particle content. Furthermore, the constraints from direct searches for heavy states at the LHC and from the Higgs search results have been included in our analysis. The best agreement with all the considered constraints is achieved for medium to large compositeness...

  18. MERCURY CONTENT IN BOTTOM SEDIMENTS OF MID-FIELD PONDS

    Directory of Open Access Journals (Sweden)

    Kamil Szydłowski

    2016-09-01

    Full Text Available Two mid-field ponds located in the agricultural catchment was chosen for the investigations. Total of 24 samples of bottom sediments were collected. The samples were taken from sediment layers: 0–5 (W1, 5–10 (W2, 10–20 (W3 and 20–30 (W4 cm, with three points at once during the 2014 winter period. Mercury content in the samples was determined by analyzer AMA 254. Higher pH (active acidity was recorded in sediments in pond located in a rural park than pond located within agricultural crops. Bottom sediment in mid-field pond (No. 1 had higher values of organic carbon averaging 22.70% than in the pond located in a rural park (No. 2, where organic carbon content averaged 4.59%. The mercury content in bottom sediments ranged from 0.02 to 0.41 mg ⋅ kg-1. The examined sediments were classified (at points P1, P2, P3 and P4 as uncontaminated sediments (Class I and at points S1 and S2 were classified as moderately polluted sediments (Class II. Bottom sediments classified as class I and II can be disposed in the aquatic and terrestrial environments. Mercury concentrations in samples collected from both banks of the pond No. 1 and 2 differ significantly (Tukey test p ≤ 0.05 than those in the samples collected from central part of the ponds. Chemical analysis of the individual layers of bottom sediments in ponds showed that the largest accumulation of mercury occurred in a layer W1 (0–5 cm in pond No. 2 (at point S2.

  19. Social and ethical checkpoints for bottom-up synthetic biology, or protocells

    OpenAIRE

    2009-01-01

    An alternative to creating novel organisms through the traditional “top-down” approach to synthetic biology involves creating them from the “bottom up” by assembling them from non-living components; the products of this approach are called “protocells.” In this paper we describe how bottom-up and top-down synthetic biology differ, review the current state of protocell research and development, and examine the unique ethical, social, and regulatory issues raised by bottom-up synthetic biology....

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

    Science.gov (United States)

    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

  1. Current state of in situ subsurface remediation by activated carbon-based amendments.

    Science.gov (United States)

    Fan, Dimin; Gilbert, Edward J; Fox, Tom

    2017-02-21

    The last decade has seen a growing interest in applying activated carbon (AC)-based amendments for in situ subsurface remediation of organic contaminants such as chlorinated solvents and petroleum hydrocarbons. This remedial technology has been promoted by several major AC-based product vendors on the market. These products involve impregnation or co-application of chemical or biological additives to facilitate various contaminant degradation processes in conjunction with contaminant adsorption. During field applications, rapid contaminant removal and limited rebound after emplacement have often been reported and considered as two major advantages for this remedial technology. Nevertheless, questions remain to be answered regarding its true effectiveness and longevity given the lack of subsequent field characterizations and evidence of the degradation process, especially biodegradation. Additional uncertainties reside in how subsurface heterogeneity may affect the design, implementation and performance monitoring of this technology. In light of these uncertainties, this review presents an independent analysis that focuses on both the scientific and practical aspects of AC-based remedial technology for in situ subsurface remediation by gathering and synthesizing the scientific knowledge and practical lessons from a broad range of contaminant removal processes involving adsorption and/or degradation. The analysis showed that the scientific soundness of combining adsorption and degradation proposed for all the AC-based products is well supported by the literature on ex situ treatment. However, the in situ effectiveness might be affected by additional factors, such as geological heterogeneity, amendment transport and distribution, and total contaminant mass, which require more thorough and quantitative evaluation. Overall, the technology may provide a viable tool in addressing major remediation challenges encountered in current practice, such as mitigation of back

  2. Analysis of All-Carbon Brick Bottom and Ceramic Cup Synthetic Hearth Bottom

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hong-bo; CHENG Shu-sen; ZHAO Min-ge

    2007-01-01

    One of the bottlenecks of the blast furnace (BF) campaign is the life length of hearth bottom. The basic reason for the erosion of hearth bottom is its direct contact with hot metal. According to the theory of heat transfer, models of BF hearth bottom are built based on the actual examples using software and VC language, and the calculated results are in good agreement with the data of BF dissection after blowing out. The temperature distribution and the capability of the resistance to erosion for different structures of hearth bottom are analyzed, especially the two prevalent kinds of hearth bottom arrangements called "the method of heat transfer" for all-carbon brick bottom and "the method of heat isolation" for ceramic synthetic hearth bottom. Features of the two kinds of hearth bottoms are analyzed. Also the different ways of protecting the hearth bottom are clarified, according to some actual examples. After that, the same essence of prolonging life, and the fact that the existence of a "protective skull" with low thermal conductivity between the hot metal and brick layers is of utmost importance are shown.

  3. Bottom-feeding for blockbuster businesses.

    Science.gov (United States)

    Rosenblum, David; Tomlinson, Doug; Scott, Larry

    2003-03-01

    Marketing experts tell companies to analyze their customer portfolios and weed out buyer segments that don't generate attractive returns. Loyalty experts stress the need to aim retention programs at "good" customers--profitable ones- and encourage the "bad" ones to buy from competitors. And customer-relationship-management software provides ever more sophisticated ways to identify and eliminate poorly performing customers. On the surface, the movement to banish unprofitable customers seems reasonable. But writing off a customer relationship simply because it is currently unprofitable is at best rash and at worst counterproductive. Executives shouldn't be asking themselves, How can we shun unprofitable customers? They need to ask, How can we make money off the customers that everyone else is shunning? When you look at apparently unattractive segments through this lens, you often see opportunities to serve those segments in ways that fundamentally change customer economics. Consider Paychex, a payroll-processing company that built a nearly billion-dollar business by serving small companies. Established players had ignored these customers on the assumption that small companies couldn't afford the service. When founder Tom Golisano couldn't convince his bosses at Electronic Accounting Systems that they were missing a major opportunity, he started a company that now serves 390,000 U.S. customers, each employing around 14 people. In this article, the authors look closely at bottom-feeders--companies that assessed the needs of supposedly unattractive customers and redesigned their business models to turn a profit by fulfilling those needs. And they offer lessons other executives can use to do the same.

  4. Painful faces-induced attentional blink modulated by top-down and bottom-up mechanisms

    OpenAIRE

    2015-01-01

    Pain-related stimuli can capture attention in an automatic (bottom-up) or intentional (top-down) fashion. Previous studies have examined attentional capture by pain-related information using spatial attention paradigms that involve mainly a bottom-up mechanism. In the current study, we investigated the pain information–induced attentional blink (AB) using a rapid serial visual presentation (RSVP) task, and compared the effects of task-irrelevant and task-relevant pain distractors. Relationshi...

  5. Cutaneous retinal activation and neural entrainment in transcranial alternating current stimulation: A systematic review

    NARCIS (Netherlands)

    Schutter, D.J.L.G.

    2016-01-01

    Transcranial alternating current stimulation (tACS) applies exogenous oscillatory electric field potentials to entrain neural rhythms and is used to investigate brain-function relationships and its potential to enhance perceptual and cognitive performance. However, due to current spread tACS can cau

  6. Application of hybrid supercapacitor using granule Li4Ti5O12/activated carbon with variation of current density

    Science.gov (United States)

    Lee, Byung-Gwan; Lee, Seung-Hwan

    2017-03-01

    We report the electrochemical performance of asymmetric hybrid supercapacitors composed of granule Li4Ti5O12 as an anode and activated carbon as a cathode with different current densities. It is demonstrated that the hybrid supercapacitors show good initial discharge capacities were ranged from 39.8 to 46.4 F g-1 in the current densities range of 0.3-1 A g-1. The performance degradation is proportional to the current density due to quick gassing, resulting from H2O and HF formation. In particular, the hybrid supercapacitors show the pretty good cycling stability of 97.4%, even at the high current density of 0.8 A g-1, which are among most important performance in the real application for energy storage devices. Therefore, we believe that hybrid supercapacitors using granule Li4Ti5O12/activated carbon are eligible for the promising next generation energy devices.

  7. Modulation by extracellular pH of low- and high-voltage-activated calcium currents of rat thalamic relay neurons.

    Science.gov (United States)

    Shah, M J; Meis, S; Munsch, T; Pape, H C

    2001-03-01

    The effects of changes in the extracellular pH (pH(o)) on low-voltage- (LVA) and high-voltage- (HVA) activated calcium currents of acutely isolated relay neurons of the ventrobasal thalamic complex (VB) were examined using the whole cell patch-clamp technique. Modest extracellular alkalinization (pH 7.3 to 7.7) reversibly enlarged LVA calcium currents by 18.6 +/- 3.2% (mean +/- SE, n = 6), whereas extracellular acidification (pH 7.3 to 6.9) decreased the current by 24.8 +/- 3.1% (n = 9). Normalized current amplitudes (I/I(7.3)) fitted as a function of pH(o) revealed an apparent pK(a) of 6.9. Both, half-maximal activation voltage and steady-state inactivation were significantly shifted to more negative voltages by 2-4 mV on extracellular alkalinization and to more positive voltages by 2-3 mV on extracellular acidification, respectively. Recovery from inactivation of LVA calcium currents was not significantly affected by changes in pH(o). In contrast, HVA calcium currents were less sensitive to changes in pH(o). Although extracellular alkalinization increased maximal HVA current by 6.0 +/- 2.0% (n = 7) and extracellular acidification decreased it by 11.9 +/- 0.02% (n = 11), both activation and steady-state inactivation were only marginally affected by the moderate changes in pH(o) used in the present study. The results show that calcium currents of thalamic relay neurons exhibit different pH(o) sensitivity. Therefore activity-related extracellular pH transients might selectively modulate certain aspects of the electrogenic behavior of thalamic relay neurons.

  8. [Blocking action of Nephila clavata spider toxin on ionic currents activated by glutamate and its agonists in isolated hippocampal neurons].

    Science.gov (United States)

    Kiskin, N I; Kliuchko, E M; Kryshtal', O A; Tsyndrenko, A Ia; Akaike, N

    1989-01-01

    The blocking action of the Nephila clavata spider neurotoxin was studied using the concentration clamp method in isolated neurons of the rat hippocampus. Crude venom JSTX blocked L-glutamate-, quisqualate- and kainate-activated ionic currents mediated by activation of the non-N-methyl-D-aspartate (non-NMDA) membrane receptors. Ionic currents elicited by all agonists were depressed by crude JSTX venom to 34-35% of its initial amplitude with no recovery during prolonged washing. An active fraction of JSTX venom blocked ionic currents almost completely, but its action was partially reversible. The concentration dependences of blocking kinetics allowed determining the rate constants of JSTX interaction with glutamate receptors. It is supposed that JSTX blocks the non-NMDA ionic channels in some of their open states and may be one of useful tools in further biochemical and electrophysiological characterization of the glutamate-mediated synaptic transmission.

  9. The SEDIBUD (Sediment Budgets in Cold Environments) Programme: Current activities and future key tasks

    Science.gov (United States)

    Beylich, A. A.; Lamoureux, S. F.; Decaulne, A.

    2012-04-01

    Projected climate change in cold regions is expected to alter melt season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. Similarly, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active layer depths. These effects will undoubtedly change surface environments in cold regions and alter the fluxes of sediments, nutrients and solutes, but the absence of quantitative data and coordinated process monitoring and analysis to understand the sensitivity of the Earth surface environment is acute in cold climate environments. The International Association of Geomorphologists (I.A.G./A.I.G.)SEDIBUD (Sediment Budgets in Cold Environments) Programme was formed in 2005 to address this existing key knowledge gap. SEDIBUD currently has about 400 members worldwide and the Steering Committee of this international programme is composed of ten scientists from eight different countries: Achim A. Beylich (Chair) (Norway), Armelle Decaulne (Secretary) (France), John C. Dixon (USA), Scott F. Lamoureux (Vice-Chair) (Canada), John F. Orwin (Canada), Jan-Christoph Otto (Austria), Irina Overeem (USA), Thorsteinn Saemundsson (Iceland), Jeff Warburton (UK), Zbigniew Zwolinski (Poland). The central research question of this global group of scientists is to: Assess and model the contemporary sedimentary fluxes in cold climates, with emphasis on both particulate and dissolved components. Initially formed as European Science Foundation (ESF) Network SEDIFLUX (2004-2006), SEDIBUD has further expanded to a global group of researchers with field research sites located in polar and alpine regions in the northern and southern hemisphere. Research carried out at each of the close to 50 defined SEDIBUD key test sites varies by programme, logistics and available resources, but typically represent interdisciplinary collaborations of

  10. Time variable bottom water outflow in the Northwestern Weddell Sea

    Science.gov (United States)

    Kanzow, Torsten; Rohardt, Gerd

    2015-04-01

    The Antarctic Bottom Water (AABW) has shown widespread warming in recent decades, with implications for sea level rise and global heat uptake. Anomalously warm AABW has recently been reported to have reached the Brazil basin in the South Atlantic, while the warming further south partly seems to have come to a halt. The Weddell Sea represents the primary source of Antarctic Bottom Water (AABW) formation in the Southern Ocean. More than 60% of the AABW are supplied by Weddell Sea Deep Water, of which Weddell Sea Bottom Water (WSBW) is the main source. WSBW descends down the continental slope along the western margin of the Weddell Sea as a northward flowing plume, thereby entraining warmer ambient waters. The plume has been observed using moored current meters and temperature sensors between 1989 and 1998 and between 2005 and 2012 near the tip of the Antarctic Peninsula, complemented by repeated cross-slope CTD sections along the mooring array. In this study we extend the WSBW volume transport and temperature time series of Fahrbach et al. (2001) originally covering the 1989-1998 interval by the more recent period. We will report on both seasonal to inter-annual variability and possible longer-term trends in both volume transport and temperature of WSBW. The results will be discussed in the context of changes in the source areas of WSBW, such as the breakup of parts of the Larsen Ice Shelf on the eastern Arctic Peninsula, possibly fueling the formation dense water on the shelf.

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

    DEFF Research Database (Denmark)

    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...... 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 harmonic DG currents, local nonlinear load harmonic current detection and distribution system harmonic...... 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...

  12. Generalized stability regions of current control for LCL-filtered grid-connected converters without passive or active damping

    DEFF Research Database (Denmark)

    Tang, Yi; Yoon, Changwoo; Zhu, Rongwu;

    2015-01-01

    This paper investigates the stability regions of current control for LCL-filtered grid-connected converters, where no active or passive damping is required to stabilize the closed-loop control system. It is already identified in the literature that if the LCL resonance frequency is placed within 1...... the resonance frequency could be larger than 1/2 of the sampling frequency, and derives the complete stability regions for both grid and converter current control. Interestingly, it is found that for any given LCL-filter design, there will always be one stable current control design without any damping, which...

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

    DEFF Research Database (Denmark)

    Matchkov, Vladimir; Aalkjær, Christian; Nilsson, Holger

    2004-01-01

    -PET-cGMP or with a peptide inhibitor of PKG, or with the nonhydrolysable ATP analogue AMP-PNP. Under biionic conditions, the anion permeability sequence of the channel was SCN- > Br- > I- > Cl- > acetate > F- >> aspartate, but the conductance sequence was I- > Br- > Cl- > acetate > F- > aspartate = SCN-. The current had...... 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 current, which...

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

    Science.gov (United States)

    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

  15. cGMP activates a pH-sensitive leak K+ current in the presumed cholinergic neuron of basal forebrain.

    Science.gov (United States)

    Toyoda, Hiroki; Saito, Mitsuru; Sato, Hajime; Dempo, Yoshie; Ohashi, Atsuko; Hirai, Toshihiro; Maeda, Yoshinobu; Kaneko, Takeshi; Kang, Youngnam

    2008-05-01

    In an earlier study, we demonstrated that nitric oxide (NO) causes the long-lasting membrane hyperpolarization in the presumed basal forebrain cholinergic (BFC) neurons by cGMP-PKG-dependent activation of leak K+ currents in slice preparations. In the present study, we investigated the ionic mechanisms underlying the long-lasting membrane hyperpolarization with special interest in the pH sensitivity because 8-Br-cGMP-induced K+ current displayed Goldman-Hodgkin-Katz rectification characteristic of TWIK-related acid-sensitive K+ (TASK) channels. When examined with the ramp command pulse depolarizing from -130 to -40 mV, the presumed BFC neurons displayed a pH-sensitive leak K+ current that was larger in response to pH decrease from 8.3 to 7.3 than in response to pH decrease from 7.3 to 6.3. This K+ current was similar to TASK1 current in its pH sensitivity, whereas it was highly sensitive to Ba(2+), unlike TASK1 current. The 8-Br-cGMP-induced K+ currents in the presumed BFC neurons were almost completely inhibited by lowering external pH to 6.3 as well as by bath application of 100 microM Ba(2+), consistent with the nature of the leak K+ current expressed in the presumed BFC neurons. After 8-Br-cGMP application, the K+ current obtained by pH decrease from 7.3 to 6.3 was larger than that obtained by pH decrease from pH 8.3 to 7.3, contrary to the case seen in the control condition. These observations strongly suggest that 8-Br-cGMP activates a pH- and Ba(2+)-sensitive leak K+ current expressed in the presumed BFC neurons by modulating its pH sensitivity.

  16. Sediment transport in the presence of large reef bottom roughness

    Science.gov (United States)

    Pomeroy, Andrew; Lowe, Ryan J.; Ghisalberti, Marco; Storlazzi, Curt; Symonds, Graham; Roelvink, Dano

    2017-01-01

    The presence of large bottom roughness, such as that formed by benthic organisms on coral reef flats, has important implications for the size, concentration, and transport of suspended sediment in coastal environments. A 3 week field study was conducted in approximately 1.5 m water depth on the reef flat at Ningaloo Reef, Western Australia, to quantify the cross-reef hydrodynamics and suspended sediment dynamics over the large bottom roughness (∼20–40 cm) at the site. A logarithmic mean current profile consistently developed above the height of the roughness; however, the flow was substantially reduced below the height of the roughness (canopy region). Shear velocities inferred from the logarithmic profile and Reynolds stresses measured at the top of the roughness, which are traditionally used in predictive sediment transport formulations, were similar but much larger than that required to suspend the relatively coarse sediment present at the bed. Importantly, these stresses did not represent the stresses imparted on the sediment measured in suspension and are therefore not relevant to the description of suspended sediment transport in systems with large bottom roughness. Estimates of the bed shear stresses that accounted for the reduced near-bed flow in the presence of large roughness vastly improved the relationship between the predicted and observed grain sizes that were in suspension. Thus, the impact of roughness, not only on the overlying flow but also on bed stresses, must be accounted for to accurately estimate suspended sediment transport in regions with large bottom roughness, a common feature of many shallow coastal ecosystems.

  17. Precious Metals in Municipal Solid Waste Incineration Bottom Ash

    Energy Technology Data Exchange (ETDEWEB)

    Muchova, Lenka; Bakker, Erwin; Rem, Peter [Faculty of Civil Engineering and Geosciences, Materials and Environment, TU Delft (Netherlands)], E-mail: P.C.REM@TUDELFT.NL

    2009-04-15

    Municipal solid waste incineration (MSWI) bottom ash contains economically significant levels of silver and gold. Bottom ashes from incinerators at Amsterdam and Ludwigshafen were sampled, processed, and analyzed to determine the composition, size, and mass distribution of the precious metals. In order to establish accurate statistics of the gold particles, a sample of heavy non-ferrous metals produced from 15 tons of wet processed Amsterdam ash was analyzed by a new technology called magnetic density separation (MDS). Amsterdam's bottom ash contains approximately 10 ppm of silver and 0.4 ppm of gold, which was found in particulate form in all size fractions below 20 mm. The sample from Ludwigshafen was too small to give accurate values on the gold content, but the silver content was found to be identical to the value measured for the Amsterdam ash. Precious metal value in particles smaller than 2 mm seems to derive mainly from waste of electrical and electronic equipment (WEEE), whereas larger precious metal particles are from jewelry and constitute the major part of the economic value. Economical analysis shows that separation of precious metals from the ash may be viable with the presently high prices of non-ferrous metals. In order to recover the precious metals, bottom ash must first be classified into different size fractions. Then, the heavy non-ferrous (HNF) metals should be concentrated by physical separation (eddy current separation, density separation, etc.). Finally, MDS can separate gold from the other HNF metals (copper, zinc). Gold-enriched concentrates can be sold to the precious metal smelter and the copper-zinc fraction to a brass or copper smelter.

  18. Automated Urban Travel Interpretation: A Bottom-up Approach for Trajectory Segmentation.

    Science.gov (United States)

    Das, Rahul Deb; Winter, Stephan

    2016-11-23

    Understanding travel behavior is critical for an effective urban planning as well as for enabling various context-aware service provisions to support mobility as a service (MaaS). Both applications rely on the sensor traces generated by travellers' smartphones. These traces can be used to interpret travel modes, both for generating automated travel diaries as well as for real-time travel mode detection. Current approaches segment a trajectory by certain criteria, e.g., drop in speed. However, these criteria are heuristic, and, thus, existing approaches are subjective and involve significant vagueness and uncertainty in activity transitions in space and time. Also, segmentation approaches are not suited for real time interpretation of open-ended segments, and cannot cope with the frequent gaps in the location traces. In order to address all these challenges a novel, state based bottom-up approach is proposed. This approach assumes a fixed atomic segment of a homogeneous state, instead of an event-based segment, and a progressive iteration until a new state is found. The research investigates how an atomic state-based approach can be developed in such a way that can work in real time, near-real time and offline mode and in different environmental conditions with their varying quality of sensor traces. The results show the proposed bottom-up model outperforms the existing event-based segmentation models in terms of adaptivity, flexibility, accuracy and richness in information delivery pertinent to automated travel behavior interpretation.

  19. Painful faces-induced attentional blink modulated by top-down and bottom-up mechanisms

    Directory of Open Access Journals (Sweden)

    Chun eZheng

    2015-06-01

    Full Text Available Pain-related stimuli can capture attention in an automatic (bottom-up or intentional (top-down fashion. Previous studies have examined attentional capture by pain-related information using spatial attention paradigms that involve mainly a bottom-up mechanism. In the current study, we investigated the pain information–induced attentional blink (AB using a rapid serial visual presentation (RSVP task, and compared the effects of task-irrelevant and task-relevant pain distractors. Relationships between accuracy of target identification and individual traits (i.e., empathy and catastrophizing thinking about pain were also examined. The results demonstrated that task-relevant painful faces had a significant pain information–induced AB effect, whereas task-irrelevant faces a near-significant trend of this effect, supporting the notion that pain-related stimuli can influence the temporal dynamics of attention. Furthermore, we found a significant negative correlation between response accuracy and pain catastrophizing score in task-relevant trials. These findings suggest that active scanning of environmental information related to pain produces greater deficits in cognition than does unintentional attention toward pain, which may represent the different ways in which healthy individuals and patients with chronic pain process pain-relevant information. These results may provide insight into the understanding of maladaptive attentional processing in patients with chronic pain.

  20. Painful faces-induced attentional blink modulated by top-down and bottom-up mechanisms.

    Science.gov (United States)

    Zheng, Chun; Wang, Jin-Yan; Luo, Fei

    2015-01-01

    Pain-related stimuli can capture attention in an automatic (bottom-up) or intentional (top-down) fashion. Previous studies have examined attentional capture by pain-related information using spatial attention paradigms that involve mainly a bottom-up mechanism. In the current study, we investigated the pain information-induced attentional blink (AB) using a rapid serial visual presentation (RSVP) task, and compared the effects of task-irrelevant and task-relevant pain distractors. Relationships between accuracy of target identification and individual traits (i.e., empathy and catastrophizing thinking about pain) were also examined. The results demonstrated that task-relevant painful faces had a significant pain information-induced AB effect, whereas task-irrelevant faces showed a near-significant trend of this effect, supporting the notion that pain-related stimuli can influence the temporal dynamics of attention. Furthermore, we found a significant negative correlation between response accuracy and pain catastrophizing score in task-relevant trials. These findings suggest that active scanning of environmental information related to pain produces greater deficits in cognition than does unintentional attention toward pain, which may represent the different ways in which healthy individuals and patients with chronic pain process pain-relevant information. These results may provide insight into the understanding of maladaptive attentional processing in patients with chronic pain.

  1. Dixie Valley Bottoming Binary Unit

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Dale [Terra-Gen Sierra Holdings, LLC, Reno, NV (United States)

    2014-12-21

    This binary plant is the first air cooled, high-output refrigeration based waste heat recovery cycle in the industry. Its working fluid is environmentally friendly and as such, the permits that would be required with a hydrocarbon based cycle are not necessary. The unit is largely modularized, meaning that the unit’s individual skids were assembled in another location and were shipped via truck to the plant site. The Air Cooled Condensers (ACC), equipment piping, and Balance of Plant (BOP) piping were constructed at site. This project further demonstrates the technical feasibility of using low temperature brine for geothermal power utilization. The development of the unit led to the realization of low temperature, high output, and environmentally friendly heat recovery systems through domestic research and engineering. The project generates additional renewable energy, resulting in cleaner air and reduced carbon dioxide emissions. Royalty and tax payments to governmental agencies will increase, resulting in reduced financial pressure on local entities. The major components of the unit were sourced from American companies, resulting in increased economic activity throughout the country.

  2. Quisqualate-activated single channel currents in neuromuscular preparations of small and large crayfish.

    Science.gov (United States)

    Finger, W; Martin, C; Pareto, A

    1988-06-01

    Single channel currents elicited by 1-5 mumol/l quisqualate in neuromuscular preparations in large (greater than 16 month old) and small (1-3 month old) crayfish were recorded by means of the patch-clamp technique. In preparations from large crayfish single channel currents of variable amplitude (-1 to -12 pA) were induced by quisqualate. The mean burst lengths of these currents were tau approximately equal to 1-2 ms. In the opener muscle of the first walking leg and the contractor epimeralis muscle of small crayfish the mean burst lengths of single channel currents evoked by quisqualate were prolonged by a factor of about 4 (tau approximately equal to 5 ms). Moreover, in the opener muscle of the first walking leg of small crayfish single channel currents of small amplitude (-0.5 to -2.5 pA) were preferentially evoked by quisqualate. By contrast, in the contractor epimeralis muscle of small crayfish mainly single channel currents of large amplitude (-10 to -12 pA) were elicited by quisqualate. The results suggest that at the stage of neuromuscular development characterizing the small crayfish, gating properties of excitatory postsynaptic channels are different from those in adult crayfish. Furthermore, the results obtained in the opener muscle of the first walking leg of small crayfish are consistent with those obtained previously by means of the noise analysis technique.

  3. From Nose to Brain: Un-Sensed Electrical Currents Applied in the Nose Alter Activity in Deep Brain Structures.

    Science.gov (United States)

    Weiss, Tali; Shushan, Sagit; Ravia, Aharon; Hahamy, Avital; Secundo, Lavi; Weissbrod, Aharon; Ben-Yakov, Aya; Holtzman, Yael; Cohen-Atsmoni, Smadar; Roth, Yehudah; Sobel, Noam

    2016-09-02

    Rules linking patterns of olfactory receptor neuron activation in the nose to activity patterns in the brain and ensuing odor perception remain poorly understood. Artificially stimulating olfactory neurons with electrical currents and measuring ensuing perception may uncover these rules. We therefore inserted an electrode into the nose of 50 human volunteers and applied various currents for about an hour in each case. This induced assorted non-olfactory sensations but never once the perception of odor. To validate contact with the olfactory path, we used functional magnetic resonance imaging to measure resting-state brain activity in 18 subjects before and after un-sensed stimulation. We observed stimulation-induced neural decorrelation specifically in primary olfactory cortex, implying contact with the olfactory path. These results suggest that indiscriminate olfactory activation does not equate with odor perception. Moreover, this effort serendipitously uncovered a novel path for minimally invasive brain stimulation through the nose.

  4. Pacemaker activity of the human sinoatrial node: Role of the hyperpolarization-activated current, I-f

    NARCIS (Netherlands)

    A.O. Verkerk; A.C.G. van Ginneken; R. Wilders

    2009-01-01

    The mechanism of primary, spontaneous cardiac pacemaker activity of the sinoatrial node (SAN) has extensively been studied in several animal species, but is virtually unexplored in man. Understanding the mechanisms of human SAN pacemaker activity is important for developing new therapeutic approache

  5. Using Active Video Games for Physical Activity Promotion: A Systematic Review of the Current State of Research

    Science.gov (United States)

    Peng, Wei; Crouse, Julia C.; Lin, Jih-Hsuan

    2013-01-01

    This systematic review evaluates interventions using active video games (AVGs) to increase physical activity and summarizes laboratory studies quantifying intensity of AVG play among children and adults. Databases (Cochrane Library, PsychInfo, PubMed, SPORTDiscus, Web of Science) and forward citation and reference list searches were used to…

  6. ATOMIZATION CAUSED BY BOTTOM FLOW ENERGY DISSIPATION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Bottom flow energy dissipation is one of the common energydissipation methods for flood-releasing structures with high water head. Measures of this energy dissipation depend mainly on the turbulent action of hydraulic jump.In this paper, the physical process and the calculating methods of the atomization caused by bottom flow energy dissipation were studied, the computation models of atomization quantity for the self-aerated flow in overflow and hydraulic jump regions are presented, and the main results are of theoretical and practical significance for the hydraulic and electric engineering.

  7. T-type Ca2+ current activity during oocyte growth and maturation in the ascidian Styela plicata.

    Directory of Open Access Journals (Sweden)

    Alessandra Gallo

    Full Text Available Voltage-dependent calcium currents play a fundamental role during oocyte maturation, mostly L-type calcium currents, whereas T-type calcium currents are involved in sperm physiology and cell growth. In this paper, using an electrophysiological and pharmacological approach, we demonstrated, for the first time in oocytes, that T-type calcium currents are present with functional consequences on the plasma membrane of growing immature oocytes of the ascidian Styela plicata. We classified three subtypes of immature oocytes at the germinal vesicle stage on the basis of their size, morphology and accessory cellular structures. These stages were clearly associated with an increased activity of T-type calcium currents and hyperpolarization of the plasma membrane. We also observed that T-type calcium currents oscillate in the post-fertilization embryonic stages, with minimal amplitude of the currents in the zygote and maximal at 8-cell stage. In addition, chemical inhibition of T-type calcium currents, obtained by applying specific antagonists, induced a significant reduction in the rate of cleavage and absence of larval formation. We suggest that calcium entry via T-type calcium channels may act as a potential pacemaker in regulating cytosolic calcium involved in fertilization and early developmental events.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. The hyperpolarization-activated non-specific cation current (In ) adjusts the membrane properties, excitability, and activity pattern of the giant cells in the rat dorsal cochlear nucleus.

    Science.gov (United States)

    Rusznák, Zoltán; Pál, Balázs; Kőszeghy, Aron; Fu, Yuhong; Szücs, Géza; Paxinos, George

    2013-03-01

    Giant cells of the cochlear nucleus are thought to integrate multimodal sensory inputs and participate in monaural sound source localization. Our aim was to explore the significance of a hyperpolarization-activated current in determining the activity of giant neurones in slices prepared from 10 to 14-day-old rats. When subjected to hyperpolarizing stimuli, giant cells produced a 4-(N-ethyl-N-phenylamino)-1,2-dimethyl-6-(methylamino) pyridinium chloride (ZD7288)-sensitive inward current with a reversal potential and half-activation voltage of -36 and -88 mV, respectively. Consequently, the current was identified as the hyperpolarization-activated non-specific cationic current (Ih ). At the resting membrane potential, 3.5% of the maximum Ih conductance was available. Immunohistochemistry experiments suggested that hyperpolarization-activated, cyclic nucleotide-gated, cation non-selective (HCN)1, HCN2, and HCN4 subunits contribute to the assembly of the functional channels. Inhibition of Ih hyperpolarized the membrane by 6 mV and impeded spontaneous firing. The frequencies of spontaneous inhibitory and excitatory postsynaptic currents reaching the giant cell bodies were reduced but no significant change was observed when evoked postsynaptic currents were recorded. Giant cells are affected by biphasic postsynaptic currents consisting of an excitatory and a subsequent inhibitory component. Inhibition of Ih reduced the frequency of these biphasic events by 65% and increased the decay time constants of the inhibitory component. We conclude that Ih adjusts the resting membrane potential, contributes to spontaneous action potential firing, and may participate in the dendritic integration of the synaptic inputs of the giant neurones. Because its amplitude was higher in young than in adult rats, Ih of the giant cells may be especially important during the postnatal maturation of the auditory system.

  10. Control of Spontaneous Firing Patterns by the Selective Coupling of Calcium Currents to Calcium Activated Potassium Currents in Striatal Cholinergic Interneurons

    OpenAIRE

    Goldberg, Joshua A.; Wilson, Charles J.

    2005-01-01

    The spontaneous firing patterns of striatal cholinergic interneurons are sculpted by potassium currents that give rise to prominent afterhyperpolarizations (AHPs): BK currents contribute to action potential (AP) repolarization; SK currents generate an apamin-sensitive medium AHP (mAHP) following each AP; and bursts of APs generate long-lasting slow AHPs (sAHPs) due to apamin-insensitive currents. As all these currents are calcium-dependent, we conducted voltage- and current-clamp whole-cell r...

  11. 24 CFR 3285.804 - Bottom board repair.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Bottom board repair. 3285.804....804 Bottom board repair. (a) The bottom board covering must be inspected for any loosening or areas... to be replaced prior to closure and repair of the bottom board. (b) Any splits or tears in the...

  12. Reduced Hyperpolarization-Activated Current Contributes to Enhanced Intrinsic Excitability in Cultured Hippocampal Neurons from PrP(-/-) Mice.

    Science.gov (United States)

    Fan, Jing; Stemkowski, Patrick L; Gandini, Maria A; Black, Stefanie A; Zhang, Zizhen; Souza, Ivana A; Chen, Lina; Zamponi, Gerald W

    2016-01-01

    Genetic ablation of cellular prion protein (PrP(C)) has been linked to increased neuronal excitability and synaptic activity in the hippocampus. We have previously shown that synaptic activity in hippocampi of PrP-null mice is increased due to enhanced N-methyl-D-aspartate receptor (NMDAR) function. Here, we focused on the effect of PRNP gene knock-out (KO) on intrinsic neuronal excitability, and in particular, the underlying ionic mechanism in hippocampal neurons cultured from P0 mouse pups. We found that the absence of PrP(C) profoundly affected the firing properties of cultured hippocampal neurons in the presence of synaptic blockers. The membrane impedance was greater in PrP-null neurons, and this difference was abolished by the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blocker ZD7288 (100 μM). HCN channel activity appeared to be functionally regulated by PrP(C). The amplitude of voltage sag, a characteristic of activating HCN channel current (I h), was decreased in null mice. Moreover, I h peak current was reduced, along with a hyperpolarizing shift in activation gating and slower kinetics. However, neither HCN1 nor HCN2 formed a biochemical complex with PrP(C). These results suggest that the absence of PrP downregulates the activity of HCN channels through activation of a cell signaling pathway rather than through direct interactions. This in turn contributes to an increase in membrane impedance to potentiate neuronal excitability.

  13. 75 FR 9593 - Agency Information Collection Activities; Proposed Renewal of Several Currently Approved...

    Science.gov (United States)

    2010-03-03

    ... manufacturing pesticide chemicals, wholesale merchandising of pesticide products, or pest management activities... pesticidal devices to protect children and adults from serious illness or injury resulting from...

  14. Hyperpolarization-activated current (I(h)) in vestibular calyx terminals: characterization and role in shaping postsynaptic events.

    Science.gov (United States)

    Meredith, Frances L; Benke, Tim A; Rennie, Katherine J

    2012-12-01

    Calyx afferent terminals engulf the basolateral region of type I vestibular hair cells, and synaptic transmission across the vestibular type I hair cell/calyx is not well understood. Calyces express several ionic conductances, which may shape postsynaptic potentials. These include previously described tetrodotoxin-sensitive inward Na(+) currents, voltage-dependent outward K(+) currents and a K(Ca) current. Here, we characterize an inwardly rectifying conductance in gerbil semicircular canal calyx terminals (postnatal days 3-45), sensitive to voltage and to cyclic nucleotides. Using whole-cell patch clamp, we recorded from isolated calyx terminals still attached to their type I hair cells. A slowly activating, noninactivating current (I(h)) was seen with hyperpolarizing voltage steps negative to the resting potential. External Cs(+) (1-5 mM) and ZD7288 (100 μM) blocked the inward current by 97 and 83 %, respectively, confirming that I(h) was carried by hyperpolarization-activated, cyclic nucleotide gated channels. Mean half-activation voltage of I(h) was -123 mV, which shifted to -114 mV in the presence of cAMP. Activation of I(h) was well described with a third order exponential fit to the current (mean time constant of activation, τ, was 190 ms at -139 mV). Activation speeded up significantly (τ=136 and 127 ms, respectively) when intracellular cAMP and cGMP were present, suggesting that in vivo I(h) could be subject to efferent modulation via cyclic nucleotide-dependent mechanisms. In current clamp, hyperpolarizing current steps produced a time-dependent depolarizing sag followed by either a rebound afterdepolarization or an action potential. Spontaneous excitatory postsynaptic potentials (EPSPs) became larger and wider when I(h) was blocked with ZD7288. In a three-dimensional mathematical model of the calyx terminal based on Hodgkin-Huxley type ionic conductances, removal of I(h) similarly increased the EPSP, whereas cAMP slightly decreased simulated EPSP size

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    . In this 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...

  16. Are the physical activity parenting practices reported by U.S. and Canadian parents captured in currently published instruments?

    Science.gov (United States)

    The purpose of this study was to compare the physical activity parenting practices (PAPPs) parents report using with the PAPPs incorporated in the published literature. PAPPs in the literature were identified by reviewing the content of 74 published PAPPs measures obtained from current systematic re...

  17. Workability and strength of lignite bottom ash geopolymer mortar.

    Science.gov (United States)

    Sathonsaowaphak, Apha; Chindaprasirt, Prinya; Pimraksa, Kedsarin

    2009-08-30

    In this paper, the waste lignite bottom ash from power station was used as a source material for making geopolymer. Sodium silicate and sodium hydroxide (NaOH) were used as liquid for the mixture and heat curing was used to activate the geopolymerization. The fineness of bottom ash, the liquid alkaline/ash ratio, the sodium silicate/NaOH ratio and the NaOH concentration were studied. The effects of the additions of water, NaOH and napthalene-based superplasticizer on the workability and strength of the geopolymer mortar were also studied. Relatively high strength geopolymer mortars of 24.0-58.0 MPa were obtained with the use of ground bottom ash with 3% retained on sieve no. 325 and mean particle size of 15.7 microm, using liquid alkaline/ash ratios of 0.429-0.709, the sodium silicate/NaOH ratios of 0.67-1.5 and 7.5-12.5M NaOH. The incorporation of water improved the workability of geopolymer mortar more effectively than the use of napthalene-based superplasticizer with similar slight reduction in strengths. The addition of NaOH solution slightly improves the workability of the mix while maintaining the strength of the geopolymer mortars.

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

    Science.gov (United States)

    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…

  19. Pacemaker current inhibition in experimental human cardiac sympathetic activation: a double-blind, randomized, crossover study

    NARCIS (Netherlands)

    Schroeder, C.; Heusser, K.; Zoerner, A.A.; Grosshennig, A.; Wenzel, D.; May, M.; Sweep, F.C.; Mehling, H.; Luft, F.C.; Tank, J.; Jordan, J.

    2014-01-01

    Hyperpolarization-activated, cyclic nucleotide-gated 4 (HCN4) channels comprise the final pathway for autonomic heart rate (HR) regulation. We hypothesized that HCN4 inhibition could reverse autonomic imbalance in a human model of cardiac sympathetic activation. Nineteen healthy men ingested oral me

  20. Mexican Bottom of Barrel Life Cycle environmental improvement proposal

    Energy Technology Data Exchange (ETDEWEB)

    Pulido, Ricardo [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, Mexico, D.F., C.P. 07730 (Mexico); Fernandez, Georgina [Universidad Nacional Autonoma de Mexico, Facultad de Ingenieria, Ciudad Universitaria, Mexico, D.F., C.P. 04510 (Mexico)

    2007-04-15

    Growing economies have the dual challenge of economical and industrial growing, but in a sustainable way and with protection of Ecosystems, all prior requirements are a must that are either satisfied or Human Kind will suffer the irreparable loss of Earth Biosphere. Prospective studies show that for the period 1990-2010 the petroleum will be heavier and richer in sulphur. In order to make a more sustainable use of Mexican heavy petroleum the actual 'Life Cycle' of Mexican Bottom of Barrel crude oil can be modified through the proposal of producing an activated carbon (CAFOB) from Mexican petroleum vacuums residue and Mexican petroleum coke applied in the flue gases desulphuration, therefore, experimental activated carbon was made from Mexican petroleum vacuums residue and petroleum coke and desulphuration adsorption tests of a synthetic flue gas mixture similar in composition to flue gases produced from the burning of Mexican heavy fuel oil were made. Commercial activated carbons were used as reference materials. The CAFOB180M experimental activated carbon showed a good desulphuration capacity compared to commercial activated carbon, showing its potentiality in the process of evolving the actual 'Life Cycle' of Mexican Bottom of Barrel crude oil to a more sustainable one. (author)

  1. Adaptive Hybrid Fuzzy-Proportional Plus Crisp-Integral Current Control Algorithm for Shunt Active Power Filter Operation

    Directory of Open Access Journals (Sweden)

    Nor Farahaida Abdul Rahman

    2016-09-01

    Full Text Available An adaptive hybrid fuzzy-proportional plus crisp-integral current control algorithm (CCA for regulating supply current and enhancing the operation of a shunt active power filter (SAPF is presented. It introduces a unique integration of fuzzy-proportional (Fuzzy-P and crisp-integral (Crisp-I current controllers. The Fuzzy-P current controller is developed to perform gain tuning procedure and proportional control action. This controller inherits the simplest configuration; it is constructed using a single-input single-output fuzzy rule configuration. Thus, an execution of few fuzzy rules is sufficient for the controller’s operation. Furthermore, the fuzzy rule is developed using the relationship of currents only. Hence, it simplifies the controller development. Meanwhile, the Crisp-I current controller is developed to perform integral control action using a controllable gain value; to improve the steady-state control mechanism. The gain value is modified and controlled using the Fuzzy-P current controller’s output variable. Therefore, the gain value will continuously be adjusted at every sample period (or throughout the SAPF operation. The effectiveness of the proposed CCA in regulating supply current is validated in both simulation and experimental work. All results have proven that the SAPF using the proposed CCA is capable to regulate supply current during steady-state and dynamic-state operations. At the same time, the SAPF is able to enhance its operation in compensating harmonic currents and reactive power. Furthermore, the implementation of the proposed CCA has resulted more stable dc-link voltage waveform.

  2. Social and ethical checkpoints for bottom-up synthetic biology, or protocells.

    Science.gov (United States)

    Bedau, Mark A; Parke, Emily C; Tangen, Uwe; Hantsche-Tangen, Brigitte

    2009-12-01

    An alternative to creating novel organisms through the traditional "top-down" approach to synthetic biology involves creating them from the "bottom up" by assembling them from non-living components; the products of this approach are called "protocells." In this paper we describe how bottom-up and top-down synthetic biology differ, review the current state of protocell research and development, and examine the unique ethical, social, and regulatory issues raised by bottom-up synthetic biology. Protocells have not yet been developed, but many expect this to happen within the next five to ten years. Accordingly, we identify six key checkpoints in protocell development at which particular attention should be given to specific ethical, social and regulatory issues concerning bottom-up synthetic biology, and make ten recommendations for responsible protocell science that are tied to the achievement of these checkpoints.

  3. 75 FR 22843 - Agency Information Collection Activities: Revision of a Currently Approved Collection; Comments...

    Science.gov (United States)

    2010-04-30

    ... evidence. The information will provide statistics on laboratories' capacity to analyze forensic crime... Currently Approved Collection 2009 Census of Publicly Funded Forensic Crime Laboratories. The Department of... and assumptions used; (3) Enhance the quality, utility, and clarity of the information to be...

  4. 76 FR 45262 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2011-07-28

    ... of information technology. Current Good Manufacturing Practices and Related Regulations for Blood and... information and counseling to a donor determined not to be eligible for donation as usual and customary... establishments would need to provide, under Sec. 630.6(a), additional information and onsite counseling to...

  5. 78 FR 69134 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Current...

    Science.gov (United States)

    2013-11-18

    ... Tenure, and Occupational Mobility Supplement,'' to the Office of Management and Budget (OMB) for review... Regulatory Affairs, Attn: OMB Desk Officer for DOL- BLS, Office of Management and Budget, Room 10235, 725... gathers data on the types of jobs reemployed workers have found and will compare current earnings...

  6. 78 FR 62631 - Agency Information Collection Activities: Revision of a Currently-Approved Collection; Comment...

    Science.gov (United States)

    2013-10-22

    ... collection unless it displays a currently valid Office of Management and Budget (OMB) control number. As part... of IRA Keogh Deposit (7200/11), Declaration of Custodian Deposit (7200/13), Declaration for Plan and... 7200/09 Declaration for Defined Contribution Plan, Form 7200/10 Declaration for IRA/KEOGH Deposit,...

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

    Institute of Scientific and Technical Information of China (English)

    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. Coil in bottom part of splitter magnet

    CERN Multimedia

    1976-01-01

    Radiation-resistant coil being bedded into the bottom part of a splitter magnet. This very particular magnet split the beam into 3 branches, for 3 target stations in the West-Area. See Annual Report 1975, p.176, Figs.14 and 15.

  9. CEOs: Gulf crisis hits hospitals' bottom line.

    Science.gov (United States)

    Johnsson, J

    1990-12-01

    Hospital CEOs say the Persian Gulf crisis could hit them hard where it counts. In fact, hospitals are already seeing some adverse impact from events in the Middle East. From fundraising to plant management to strategic planning, the confrontations in the Gulf are having an impact on the hospital's bottom line.

  10. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

    2007-01-01

    This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearized versions of the model are analyzed and show large variations in system gains at steady state as function of load whereas gain variations near the desired bandwidth are small. An analysis...

  11. Bottom-up organic integrated circuits

    NARCIS (Netherlands)

    Smits, Edsger C. P.; Mathijssen, Simon G. J.; van Hal, Paul A.; Setayesh, Sepas; Geuns, Thomas C. T.; Mutsaers, Kees A. H. A.; Cantatore, Eugenio; Wondergem, Harry J.; Werzer, Oliver; Resel, Roland; Kemerink, Martijn; Kirchmeyer, Stephan; Muzafarov, Aziz M.; Ponomarenko, Sergei A.; de Boer, Bert; Blom, Paul W. M.; de Leeuw, Dago M.

    2008-01-01

    Self- assembly - the autonomous organization of components into patterns and structures(1) - is a promising technology for the mass production of organic electronics. Making integrated circuits using a bottom- up approach involving self- assembling molecules was proposed(2) in the 1970s. The basic b

  12. Bottomonia: open bottom strong decays and spectrum

    Directory of Open Access Journals (Sweden)

    Santopinto E.

    2014-05-01

    Full Text Available We present our results for the bottomonium spectrum with self energy corrections. The bare masses used in the calculation are computed within Godfrey and Isgur’s relativized quark model. We also discuss our results for the open bottom strong decay widths of higher bottomonia in the 3P0 pair-creation model.

  13. Early life determinants of physical activity and sedentary time: Current knowledge and future research

    Directory of Open Access Journals (Sweden)

    Guro Pauck Øglund

    2014-12-01

    Full Text Available Previous findings of the association between low birth weight and subsequent health outcomes have led to the “developmental origins of health and disease hypothesis”. Furthermore, modifiable and partly modifiable early life factors may also influence behaviors such as physical activity and sedentary behavior. The aim of the present review was to summarize the existing knowledge on early life determinants (birth weight, rapid infant weight gain, motor development and infant temperament of childhood physical activity and sedentary time, and suggest opportunities for future research based on the Mother and Child Cohort Study (MoBa. Inconsistent results have been observed when relating birth weight to later physical activity, likely explained by differences in methodology when assessing physical activity between studies. There is limited data on whether rapid weight gain in early life predicts later physical activity and few studies have examined the association between birth weight and infant weight gain with subsequent sedentary time. Motor development may be a predictor for childhood physical activity, however methodological limitations preclude firm conclusions. The association between motor development and sedentary time has rarely been examined. Conflicting results have been reported for the association between infant temperament and subsequent physical activity and sedentary time in toddlers. Finally, it is unknown whether physical activity modifies the association between birth weight, postnatal weight gain, and later health outcomes in youth. Additional research in well-characterized birth cohorts can be used to generate new knowledge on possible early life determinants of children’s and youth’s physical activity and sedentary time which may inform evidence-based public health interventions.

  14. [Effects of posttranslational modification on the activity of cytochrome P450: current progress].

    Science.gov (United States)

    Li, Yu-hua; Bi, Hui-chang; Huang, Min

    2011-05-01

    Regulation of the activity of CYP450 has always been research focus of drug metabolism. The effect of compounds on the mRNA and protein expression level of CYP450 is the main purpose of most of the existing reports. In recent years, the protein modification in the posttranslation level has been found to participate in maintaining the proper function of CYP450, thus effect of posttranslational modification on the enzyme activity has been paid more and more attention. Posttranslational modifications including phosphorylation, nitration, and ubiquitination have been described to regulate the activity of CYP450. In this paper, recent developments in the effects of posttranslational modifications on the activity of CYP450 have been reviewed.

  15. Current limitations and recommendations to improve testing for the environmental assessment of endocrine active substances

    Science.gov (United States)

    In this paper existing regulatory frameworks and test systems for assessing potential endocrine-active chemicals are described, and associated challenges discussed, along with proposed approaches to address these challenges. Regulatory frameworks vary somewhat across organizatio...

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

    Directory of Open Access Journals (Sweden)

    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

  17. Short-term desensitization of G-protein-activated, inwardly rectifying K+ (GIRK) currents in pyramidal neurons of rat neocortex.

    Science.gov (United States)

    Sickmann, Thomas; Alzheimer, Christian

    2003-10-01

    Whole cell recordings from acutely isolated rat neocortical pyramidal cells were performed to study the kinetics and the mechanisms of short-term desensitization of G-protein-activated, inwardly rectifying K+ (GIRK) currents during prolonged application (5 min) of baclofen, adenosine, or serotonin. Most commonly, desensitization of GIRK currents was characterized by a biphasic time course with average time constants for fast and slow desensitization in the range of 8 and 120 s, respectively. The time constants were independent of the agonist used to evoke the current. The biphasic time course was preserved in perforated-patch recordings, indicating that neither component of desensitization is attributable to cell dialysis. Desensitization of GIRK currents displayed a strong heterologous component in that application of a second agonist substantially reduced the responsiveness to a test agonist. Fast desensitization, but not slow desensitization, was lost in cells loaded with GDP, suggesting that the hydrolysis cycle of G proteins might underlie the initial, rapid current decline. Hydrolysis of phosphatidylinositol biphosphate is an unlikely candidate underlying short-term desensitization, because both components of desensitization were preserved in the presence of the phospholipase C inhibitor U73122. We conclude that short-term desensitization does neither result from receptor downregulation nor from altered channel gating but might involve modifications of the G-protein-dependent pathway that serves to translate receptor activation into channel opening.

  18. Activation of Ih and TTX-sensitive sodium current at subthreshold voltages during CA1 pyramidal neuron firing.

    Science.gov (United States)

    Yamada-Hanff, Jason; Bean, Bruce P

    2015-10-01

    We used dynamic clamp and action potential clamp techniques to explore how currents carried by tetrodotoxin-sensitive sodium channels and HCN channels (Ih) regulate the behavior of CA1 pyramidal neurons at resting and subthreshold voltages. Recording from rat CA1 pyramidal neurons in hippocampal slices, we found that the apparent input resistance and membrane time constant were strongly affected by both conductances, with Ih acting to decrease apparent input resistance and time constant and sodium current acting to increase both. We found that both Ih and sodium current were active during subthreshold summation of artificial excitatory postsynaptic potentials (EPSPs) generated by dynamic clamp, with Ih dominating at less depolarized voltages and sodium current at more depolarized voltages. Subthreshold sodium current-which amplifies EPSPs-was most effectively recruited by rapid voltage changes, while Ih-which blunts EPSPs-was maximal for slow voltage changes. The combined effect is to selectively amplify rapid EPSPs. We did similar experiments in mouse CA1 pyramidal neurons, doing voltage-clamp experiments using experimental records of action potential firing of CA1 neurons previously recorded in awake, behaving animals as command voltages to quantify flow of Ih and sodium current at subthreshold voltages. Subthreshold sodium current was larger and subthreshold Ih was smaller in mouse neurons than in rat neurons. Overall, the results show opposing effects of subthreshold sodium current and Ih in regulating subthreshold behavior of CA1 neurons, with subthreshold sodium current prominent in both rat and mouse CA1 pyramidal neurons and additional regulation by Ih in rat neurons.

  19. Observations of Near-Bottom Currents with Low-Cost SeaHorse Tilt Current Meters

    Science.gov (United States)

    2010-09-30

    for channel vs bay interior conditions. The deployment/recovery operations were assisted Chris Weidman and other staff at the Waquoit Bay Natural ...Each drifter was monitored (and if necessary followed) by a student in a kayak or small boat for about one hour. GPS receivers were set to collect

  20. Effect of ivaradine on hyperpolarization activated cation current in canine pulmonary vein sleeve cardiomyocytes with atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    Yang Li; Yan Huang; Zongbin Li; Hao Wang; Jianguo Song; Yuqi Liu; Lei Gao; Shiwen Wang

    2008-01-01

    Objective To study the effect of ivabradine on hyperpolarization activated cation current in canine pulmonary vein(PY) sleeve cardiomyocytes with atrial fibrillation.Methods Dissociation of PVs yielded single cardiomyocytes from a Landengorff column without or with pacemaker activity from long-term rapidly atrial pacing (RAP) canines.If current was measured with the whole-cell patch-clamp technique.Results Compared with the control group,the rapidly atrial pacing canine PV cardiomyocytes had spontaneous diastolic depolarization and had larger If densities.Ivabradine (Iva,1 μM),a selective inhibitor of the If current,markedly reduced If currents in the RAP from -2.66±0.4 pA/pF to -1.58±0.1 pA/pF at the test potential of-120 mV (P<0.01,n=12).Inhibition effect of Iva of If current showed concentration-dependent range from 0.1 to 10.0μM,with IC50 of 2.2 μ M ( 1.8-2.9 μM,95% CL).Furthermore,V1/ of steady-state activated curve was shifted from -84.3±4.9 mV to -106.9±3.4 mV and k value of steady-state activated curve was changed from 12.1+2.6 mV to 9.9±3.4 mV by the application of.1.0 μM Iva ( P<0.01,n=12).Conclusions Our study revealed that Ivarbadine may significantly decrease If of rapidly atrial pacing pulmonary vein sleeve ceUs with atrial fibdllation.(J Geriatr Cardiol 2008;5:39-42)

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

    Science.gov (United States)

    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

  2. Preferential effect of isoflurane on top-down versus bottom-up pathways in sensory cortex

    Directory of Open Access Journals (Sweden)

    Aeyal eRaz

    2014-10-01

    Full Text Available The mechanism of loss of consciousness (LOC under anesthesia is unknown. Because consciousness depends on activity in the cortico-thalamic network, anesthetic actions on this network are likely critical for LOC. Competing theories stress the importance of anesthetic actions on bottom-up ‘core’ thalamo-cortical (TC versus top-down cortico-cortical (CC and matrix TC connections. We tested these models using laminar recordings in rat auditory cortex in-vivo and murine brain slices. We selectively activated bottom-up vs. top-down afferent pathways using sensory stimuli in vivo and electrical stimulation in brain slices, and compared effects of isoflurane on responses evoked via the two pathways. Auditory stimuli in vivo and core TC afferent stimulation in brain slices evoked short latency current sinks in middle layers, consistent with activation of core TC afferents. By contrast, visual stimuli in vivo and stimulation of CC and matrix TC afferents in brain slices evoked responses mainly in superficial and deep layers, consistent with projection patterns of top-down afferents that carry visual information to auditory cortex. Responses to auditory stimuli in vivo and core TC afferents in brain slices were significantly less affected by isoflurane compared to responses triggered by visual stimuli in vivo and CC/matrix TC afferents in slices. At a just-hypnotic dose in vivo, auditory responses were enhanced by isoflurane, whereas visual responses were dramatically reduced. At a comparable concentration in slices, isoflurane suppressed both core TC and CC/matrix TC responses, but the effect on the latter responses was far greater than on core TC responses, indicating that at least part of the differential effects observed in vivo were due to local actions of isoflurane in auditory cortex. These data support a model in which disruption of top-down connectivity contributes to anesthesia-induced LOC, and have implications for understanding the neural

  3. β-Adrenergic activation enhances NMDA-induced current in pyramidal cells of the basolateral nucleus of amygdala

    Institute of Scientific and Technical Information of China (English)

    LIU Xinqiu; CAO Xiaohua; LI Bao-ming

    2005-01-01

    NMDA receptor (NMDA-R) in the amygdala complex is critical for both long-term potentiation (LTP) and formation of conditioned fear memory. It is reported that activation of β-adrenoceptors (β-AR) in the amygdala facilitates LTP and enhances memory consolidation. The present study examined the regulatory effect of β-AR activation on NMDA-R mediated current in pyramidal cells of the basolateral nucleus of amygdala (BLA), using whole-cell recording technique. Bath application of the β-AR agonist isoproterenol enhanced NMDA-induced current, and this facilitatory effect was blocked by co-administered propranolol, a β-AR antagonist. The facilitatory effect of isoproterenol on NMDA-induced current could not be induced when the protein kinase A (PKA) inhibitor Rp-cAMPs was added in electrode internal solution.The present results suggest that β-AR activation in the BLA could modulate NMDA-R activity directly and positively, probably via PKA.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Sensitization of voltage activated calcium channel currents for capsaicin in nociceptive neurons by tumor-necrosis-factor-alpha.

    Science.gov (United States)

    Hagenacker, T; Czeschik, J C; Schäfers, M; Büsselberg, D

    2010-01-15

    It is known that application of tumor-necrosis-factor-alpha (TNF-alpha) sensitizes neuronal calcium channels for heat stimuli in rat models of neuropathic pain. This study examines whether TNF-alpha modulates the capsaicin-induced effects after transient receptor potential vanilloid (TRPV)-1 receptor activation on voltage activated calcium channel currents (I(Ca(V))). TRPV-1 receptors are activated by heat and play an important role in the pathogenesis of thermal hyperalgesia in neuropathic pain syndromes, while voltage activated channels are essential for transmission of neuronal signals. Eliciting I(Ca(V)) in DRG neurons of rats by a depolarization from the resting potential to 0 mV, TNF-alpha (100 ng/ml) reduces I(Ca(V)) by 16.9+/-2.2%, while capsaicin (0.1 microM) decreases currents by 27+/-4.3%. Pre-application of TNF-alpha (100 ng/ml) for 24h results in a sensitization of I(Ca(V)) to capsaicin (0.1 microM) with a reduction of 42.8+/-4.4% mediated by TRPV-1. While L-type (36.6+/-5.2%) and P/Q-type currents (35.6+/-4.1%) are also sensitized by TRPV-1 activation, N-type channel currents are most sensitive (74.5+/-7.3%). The capsaicin-induced shift towards the hyperpolarizing voltage range does not occur when TNF-alpha is applied. Summarizing, TNF-alpha sensitizes nociceptive neurons for capsaicin.

  6. A High-Performance Current-Mode Source Driver IC for Mobile Active Matrix Organic Light Emitting Diode Displays

    Science.gov (United States)

    Jeong, Il-Hun; Kwon, Oh-Kyong

    2008-03-01

    In this paper, we describe two types of 8-bit current-mode driver ICs with a small area and good performance for applications high accuracy current-mode digital-to-analog converters (DACs), and improved channel-to-channel uniformity for active matrix organic light-emitting diode (AMOLED) displays. One uses the proposed current steering DAC (type A), which is an improved architecture of a binary-weighted DAC, and the other uses a DAC that is a combination of a thermometer-decoded of the DAC and a binary-weighted type. The measured results show that the peak integral nonlinearity (INL) is within ±0.5 the least significant bit (LSB), the peak differential nonlinearity (DNL) is within ±0.5 LSB, and the nonuniformity of output current among channels and chips is within ±0.5 LSB. The size of the driver IC is 15,820 ×1,500 µm2 and the total power consumption of the current-mode driver IC is less than 9 mW when the display has full-white pattern with a luminance of 150 cd/m2. The chip area and power consumption with the proposed current DAC are reduced by 26 and 10%, respectively, compared with those of conventional driver ICs with a fully binary-weighted DAC.

  7. Current parallel chemistry principles and practice: application to the discovery of biologically active molecules.

    Science.gov (United States)

    Edwards, Paul J

    2009-11-01

    This article describes the use of parallel chemistry techniques for drug discovery, based on publications from January 2006 to December 2008. Chemical libraries that yielded active compounds across a range of biological targets are presented, together with synthetic details when appropriate. Background information for the biological targets involved and any SAR that could be discerned within members of a library series also is discussed. New technological developments, as applied to library design and synthesis and, more generally, in the discovery of biologically active entities, are highlighted. In addition, the likely future directions for parallel chemistry in its ability to impact upon drug discovery are also presented.

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

    Science.gov (United States)

    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.

  9. Active penetration of Trypanosoma cruzi into host cells: historical considerations and current concepts

    Directory of Open Access Journals (Sweden)

    Tecia Maria Ulisses Carvalho

    2013-01-01

    Full Text Available A significant number of scientific groups working on several countries have made efforts to better understand the process of invasion of several types of host cells by Trypanosoma cruzi, the etiologic agent of Chagas disease. In this mini-review we analyze the two mechanisms of invasion considered to be relevant: active penetration and endocytosis. The term active penetration is considered in view of its original description by Dvorak and co-workers. Taking into consideration all results obtained we conclude that endocytosis, with its many variations, is the only mechanism used by T. cruzi to invade host cells.

  10. Excited bottom and bottom-strange mesons in the quark model

    Science.gov (United States)

    Lü, Qi-Fang; Pan, Ting-Ting; Wang, Yan-Yan; Wang, En; Li, De-Min

    2016-10-01

    In order to understand the possible q q ¯ quark-model assignments of the BJ(5840 ) and BJ(5960 ) recently reported by the LHCb Collaboration, we evaluate mass spectra, strong decays, and radiative decays of bottom and bottom-strange mesons in a nonrelativistic quark model. Comparing these predictions with the relevant experimental results, we suggest that the BJ(5840 ) and BJ(5960 ) can be identified as the B (2 1S0) and B (1 3D3) , respectively, and the B (5970 ) reported by the CDF Collaboration can be interpreted as the B (2 3S1) or B (1 3D3) . Further precise measurements of the width, spin and decay modes of the B (5970 ) are needed to distinguish these two assignments. These predictions of bottom and bottom-strange mesons can provide useful information to further experimental investigations.

  11. Excited bottom and bottom-strange mesons in the quark model

    CERN Document Server

    Lü, Qi-Fang; Wang, Yan-Yan; Wang, En; Li, De-Min

    2016-01-01

    In order to understand the possible $q\\bar{q}$ quark-model assignments of the $B_J(5840)$ and $B_J(5960)$ recently reported by the LHCb Collaboration, we evaluate mass spectra, strong decays, and radiative decays of bottom and bottom-strange mesons in a nonrelativistic quark model. Comparing these predictions with the relevant experimental results, we suggest that the $B_J(5840)$ and $B_J(5960)$ can be identified as $B(2^1S_0)$ and $B(1^3D_3)$, respectively, and the $B(5970)$ reported by the CDF Collaboration can be interpreted as $B(2^3S_1)$ or $B(1^3D_3)$. Further precise measurements of the width, spin and decay modes of the $B(5970)$ are needed to distinguish these two assignments. These predictions of bottom and bottom-strange mesons can provide useful information to further experimental investigations.

  12. Comparative ecophysiology of active zoobenthic filter feeding, essence of current knowledge

    Science.gov (United States)

    Riisgård, H. U.; Larsen, P. S.

    2000-12-01

    The present contribution gives an overview of current knowledge of a comprehensive and steadily growing research field. The first section deals with water pumping and particle retention mechanisms in ciliary and muscular filter feeders. The second section examines the biological filter pumps in order to assess adaptation to the environment. Filter-feeding benthic invertebrates have evolved filter pumps to solve common basic problems. This has led to a large degree of similarity between otherwise distant standing species, which makes comparative studies interesting and important. The present review of zoobenthic filter feeding aims at accentuating such recognition.

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    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...... controller is realized as the superposition of all individual harmonic controllers. The frequency response of the entire closed loop control is optimal with respect to filtering objectives, i.e., the system provides good overall stability and excellent selectivity for interesting harmonics. This conclusion...

  14. Passivity enhancement by series LC filtered active damper with zero current reference

    DEFF Research Database (Denmark)

    Bai, Haofeng; Wang, Xiongfei; Blaabjerg, Frede

    2016-01-01

    stability analysis of grid converters in the weak grid. Based on the impedance model of the series LC filtered active damper, the real part of its output admittance is investigated and shown to be able to enhance the passivity of the admittance of the converters seen by the grid. Finally, simulation...

  15. Modulation of membrane potential by an acetylcholine-activated potassium current in trout atrial myocytes

    DEFF Research Database (Denmark)

    Molina, C.E.; Gesser, Hans; Llach, A.

    2007-01-01

    in both atrial myocytes and tissue, and this effect was antagonized by atropine. When applied alone, atropine prolonged the action potential in atrial tissue but had no effect on membrane potential, action potential, or Im in isolated atrial myocytes. This suggests that ACh-mediated activation...

  16. Critical currents and thermally activated flux motion in high-temperature superconductors

    NARCIS (Netherlands)

    Palstra, T.T.M.; Batlogg, B.; Dover, R.B. van; Schneemeyer, L.F.; Waszczak, J.V.

    1989-01-01

    We have measured the resistance below Tc of single crystals of the high-temperature superconductors Ba2YCu3O7 and Bi2.2Sr2Ca0.8Cu2O8+δ in magnetic fields up to 12 T. The resistive transition of both compounds is dominated by intrinsic dissipation which is thermally activated, resulting in an exponen

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

    Directory of Open Access Journals (Sweden)

    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

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

    DEFF Research Database (Denmark)

    Taxvig, Camilla; Hadrup, Niels; Boberg, Julie

    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...

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

    Science.gov (United States)

    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.

  20. 75 FR 61814 - Agency Information Collection Activities: Notice of Request for Extension of Currently Approved...

    Science.gov (United States)

    2010-10-06

    ... FHWA and other DOT agencies to evaluate changes in truck travel in order to assess impacts on highway... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Highway Administration Agency Information Collection Activities: Notice of Request for...

  1. An Examination of Current Adapted Physical Activity Provision in Primary and Special Schools in Ireland

    Science.gov (United States)

    Crawford, Susan

    2011-01-01

    The Disability in Sport Taskforce report examining adapted physical activity (APA) in the Irish context (Department of Education and Science, 1999) found that teachers involved in primary mainstream and specialist settings expressed a grave lack of self-confidence, due to lack of training, in the delivery of APA programmes to children with special…

  2. Treated bottom ash medium and method of arsenic removal from drinking water

    Science.gov (United States)

    Gadgil, Ashok

    2009-06-09

    A method for low-cost arsenic removal from drinking water using chemically prepared bottom ash pre-treated with ferrous sulfate and then sodium hydroxide. Deposits on the surface of particles of bottom ash form of activated iron adsorbent with a high affinity for arsenic. In laboratory tests, a miniscule 5 grams of pre-treated bottom ash was sufficient to remove the arsenic from 2 liters of 2400 ppb (parts per billion) arsenic-laden water to a level below 50 ppb (the present United States Environmental Protection Agency limit). By increasing the amount of pre-treated bottom ash, even lower levels of post-treatment arsenic are expected. It is further expected that this invention supplies a very low-cost solution to arsenic poisoning for large population segments.

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

    DEFF Research Database (Denmark)

    Diness, Thomas G; Yeh, Yung-Hsin; Qi, Xiao Yan;

    2008-01-01

    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...... ventricular ectopy, and TdP. Infusion of NS1643 completely suppressed arrhythmic activity and shortened the QT interval; vehicle had no effect. NS1643 also suppressed ventricular tachyarrhythmias caused by infusion of dofetilide to methoxamine-sensitized rabbits, and reversed dofetilide-induced QT...

  4. Direct current (DC) resistivity and Induced Polarization (IP) monitoring of active layer dynamics at high temporal resolution

    DEFF Research Database (Denmark)

    Doetsch, J.; Fiandaca, G.; Ingeman-Nielsen, Thomas;

    2015-01-01

    With permafrost thawing and changes in active layer dynamics induced by climate change, interactions between biogeochemical and thermal processes in the ground are of great importance. Here, active layer dynamics have been monitored using direct current (DC) resistivity and induced polarization (IP...... the soil freezing as a strong increase in resistivity. While the freezing horizon generally moves deeper with time, some variations in the freezing depth are observed along the profile. Comparison with depth-specific soil temperature indicates an exponential relationship between resistivity and below...

  5. Turbine Technology Team - An overview of current and planned activities relevant to the National Launch System (NLS)

    Science.gov (United States)

    Griffin, Lisa W.; Huber, Frank W.

    1992-01-01

    The current status of the activities and future plans of the Turbine Technology Team of the Consortium for Computational Fluid Dynamics is reviewed. The activities of the Turbine Team focus on developing and enhancing codes and models, obtaining data for code validation and general understanding of flows through turbines, and developing and analyzing the aerodynamic designs of turbines suitable for use in the Space Transportation Main Engine fuel and oxidizer turbopumps. Future work will include the experimental evaluation of the oxidizer turbine configuration, the development, analysis, and experimental verification of concepts to control secondary and tip losses, and the aerodynamic design, analysis, and experimental evaluation of turbine volutes.

  6. Inhibitors of arachidonate-regulated calcium channel signaling suppress triggered activity induced by the late sodium current.

    Science.gov (United States)

    Wolkowicz, Paul; Umeda, Patrick K; Sharifov, Oleg F; White, C Roger; Huang, Jian; Mahtani, Harry; Urthaler, Ferdinand

    2014-02-05

    Disturbances in myocyte calcium homeostasis are hypothesized to be one cause for cardiac arrhythmia. The full development of this hypothesis requires (i) the identification of all sources of arrhythmogenic calcium and (ii) an understanding of the mechanism(s) through which calcium initiates arrhythmia. To these ends we superfused rat left atria with the late sodium current activator type II Anemonia sulcata toxin (ATXII). This toxin prolonged atrial action potentials, induced early afterdepolarization, and provoked triggered activity. The calmodulin-dependent protein kinase II (CaMKII) inhibitor KN-93 (N-[2-[[[3-(4-chlorophenyl)-2-propenyl]methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulphon-amide) suppressed ATXII triggered activity but its inactive congener KN-92 (2-[N-(4-methoxy benzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine) did not. Neither drug affected normal atrial contractility. Calcium entry via L-type channels or calcium leakage from sarcoplasmic reticulum stores are not critical for this type of ectopy as neither verapamil ((RS)-2-(3,4-dimethoxyphenyl)-5-{[2-(3,4-dimethoxyphenyl)ethyl]-(methyl)amino}-2-prop-2-ylpentanenitrile) nor ryanodine affected ATXII triggered activity. By contrast, inhibitors of the voltage independent arachidonate-regulated calcium (ARC) channel and the store-operated calcium channel specifically suppressed ATXII triggered activity without normalizing action potentials or affecting atrial contractility. Inhibitors of cytosolic calcium-dependent phospholipase A2 also suppressed triggered activity suggesting that this lipase, which generates free arachidonate, plays a key role in ATXII ectopy. Thus, increased left atrial late sodium current appears to activate atrial Orai-linked ARC and store operated calcium channels, and these voltage-independent channels may be unexpected sources for the arrhythmogenic calcium that underlies triggered activity.

  7. Contribution of presynaptic calcium-activated potassium currents to transmitter release regulation in cultured Xenopus nerve-muscle synapses.

    Science.gov (United States)

    Pattillo, J M; Yazejian, B; DiGregorio, D A; Vergara, J L; Grinnell, A D; Meriney, S D

    2001-01-01

    Using Xenopus nerve-muscle co-cultures, we have examined the contribution of calcium-activated potassium (K(Ca)) channels to the regulation of transmitter release evoked by single action potentials. The presynaptic varicosities that form on muscle cells in these cultures were studied directly using patch-clamp recording techniques. In these developing synapses, blockade of K(Ca) channels with iberiotoxin or charybdotoxin decreased transmitter release by an average of 35%. This effect would be expected to be caused by changes in the late phases of action potential repolarization. We hypothesize that these changes are due to a reduction in the driving force for calcium that is normally enhanced by the local hyperpolarization at the active zone caused by potassium current through the K(Ca) channels that co-localize with calcium channels. In support of this hypothesis, we have shown that when action potential waveforms were used as voltage-clamp commands to elicit calcium current in varicosities, peak calcium current was reduced only when these waveforms were broadened beginning when action potential repolarization was 20% complete. In contrast to peak calcium current, total calcium influx was consistently increased following action potential broadening. A model, based on previously reported properties of ion channels, faithfully reproduced predicted effects on action potential repolarization and calcium currents. From these data, we suggest that the large-conductance K(Ca) channels expressed at presynaptic varicosities regulate transmitter release magnitude during single action potentials by altering the rate of action potential repolarization, and thus the magnitude of peak calcium current.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Stabilization of bottom sediments from Rzeszowski Reservoir

    Directory of Open Access Journals (Sweden)

    Koś Karolina

    2015-06-01

    Full Text Available The paper presents results of stabilization of bottom sediments from Rzeszowski Reservoir. Based on the geotechnical characteristics of the tested sediments it was stated they do not fulfill all the criteria set for soils in earth embankments. Therefore, an attempt to improve their parameters was made by using two additives – cement and lime. An unconfined compressive strength, shear strength, bearing ratio and pH reaction were determined on samples after different time of curing. Based on the carried out tests it was stated that the obtained values of unconfined compressive strength of sediments stabilized with cement were relatively low and they did not fulfill the requirements set by the Polish standard, which concerns materials in road engineering. In case of lime stabilization it was stated that the tested sediments with 6% addition of the additive can be used for the bottom layers of the improved road base.

  10. Constructing bottom barriers with met grouting

    Energy Technology Data Exchange (ETDEWEB)

    Shibazaki, M.; Yoshida, H. [Chemical Grouting Company, Tokyo (Japan)

    1997-12-31

    Installing a bottom barrier using conventional high pressure jetting technology and ensuring barrier continuity is challenging. This paper describes technology that has been developed and demonstrated for the emplacement of bottom barriers using pressures and flow rates above the conventional high pressure jetting parameters. The innovation capable of creating an improved body exceeding 5 meters in diameter has resulted in the satisfying connection and adherence between the treated columns. Besides, the interfaces among the improved bodies obtain the same strength and permeability lower than 1 x 10{sup -7} cm/sec as body itself. A wide variety of the thickness and the diameter of the improved mass optimizes the application, and the method is nearing completion. The paper explains an aspect and briefs case histories.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. A short review of activated carbon assisted electrosorption process: an overview, current stage and future prospects.

    Science.gov (United States)

    Foo, K Y; Hameed, B H

    2009-10-30

    Stepping into the new globalizes and paradigm shifted era, a huge revolution has been undergone by the electrochemical industry. From a humble candidate of the superconductor resources, today electrosorption has demonstrated its wide variety of usefulness, almost in every part of the environmental conservation. With the renaissance of activated carbon (AC), there has been a steadily growing interest in this research field. The paper presents a state of art review of electrosorption technology, its background studies, fundamental chemistry and working principles. Moreover, recent development of the activated carbon assisted electrosorption process, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of electrosorption in the field of adsorption science represents a potentially viable and powerful tool, leading to the superior improvement of pollution control and environmental preservation.

  13. Modulation by endothelin-1 of spontaneous activity and membrane currents of atrioventricular node myocytes from the rabbit heart.

    Directory of Open Access Journals (Sweden)

    Stéphanie C Choisy

    Full Text Available BACKGROUND: The atrioventricular node (AVN is a key component of the cardiac pacemaker-conduction system. Although it is known that receptors for the peptide hormone endothelin-1 (ET-1 are expressed in the AVN, there is very little information available on the modulatory effects of ET-1 on AVN electrophysiology. This study characterises for the first time acute modulatory effects of ET-1 on AVN cellular electrophysiology. METHODS: Electrophysiological experiments were conducted in which recordings were made from rabbit isolated AVN cells at 35-37°C using the whole-cell patch clamp recording technique. RESULTS: Application of ET-1 (10 nM to spontaneously active AVN cells led rapidly (within ~13 s to membrane potential hyperpolarisation and cessation of spontaneous action potentials (APs. This effect was prevented by pre-application of the ET(A receptor inhibitor BQ-123 (1 µM and was not mimicked by the ET(B receptor agonist IRL-1620 (300 nM. In whole-cell voltage-clamp experiments, ET-1 partially inhibited L-type calcium current (I(Ca,L and rapid delayed rectifier K(+ current (I(Kr, whilst it transiently activated the hyperpolarisation-activated current (I(f at voltages negative to the pacemaking range, and activated an inwardly rectifying current that was inhibited by both tertiapin-Q (300 nM and Ba(2+ ions (2 mM; each of these effects was sensitive to ET(A receptor inhibition. In cells exposed to tertiapin-Q, ET-1 application did not produce membrane potential hyperpolarisation or immediate cessation of spontaneous activity; instead, there was a progressive decline in AP amplitude and depolarisation of maximum diastolic potential. CONCLUSIONS: Acutely applied ET-1 exerts a direct modulatory effect on AVN cell electrophysiology. The dominant effect of ET-1 in this study was activation of a tertiapin-Q sensitive inwardly rectifying K(+ current via ET(A receptors, which led rapidly to cell quiescence.

  14. Sanguinaria canadensis: Traditional Medicine, Phytochemical Composition, Biological Activities and Current Uses

    Directory of Open Access Journals (Sweden)

    Andrew Croaker

    2016-08-01

    Full Text Available Sanguinaria canadensis, also known as bloodroot, is a traditional medicine used by Native Americans to treat a diverse range of clinical conditions. The plants rhizome contains several alkaloids that individually target multiple molecular processes. These bioactive compounds, mechanistically correlate with the plant’s history of ethnobotanical use. Despite their identification over 50 years ago, the alkaloids of S. canadensis have not been developed into successful therapeutic agents. Instead, they have been associated with clinical toxicities ranging from mouthwash induced leukoplakia to cancer salve necrosis and treatment failure. This review explores the historical use of S. canadensis, the molecular actions of the benzophenanthridine and protopin alkaloids it contains, and explores natural alkaloid variation as a possible rationale for the inconsistent efficacy and toxicities encountered by S. canadensis therapies. Current veterinary and medicinal uses of the plant are studied with an assessment of obstacles to the pharmaceutical development of S. canadensis alkaloid based therapeutics.

  15. Bottoming out-Sign of Stabilization

    Institute of Scientific and Technical Information of China (English)

    Dennis K. Zhao

    2009-01-01

    @@ Production Rose from its Nadir Apart from individual data report.CNTAC was a lot more focused on an overall review of textile industry as a whole to illustrate economic behavior for the first five months."sign of stabilization,bottoming out"are the key words emphatically voiced as a token of encou ragement,for the important economic indexes are indeed encouraging as compa red with this fi rst quarter.

  16. PARKA II-A Bottom Loss Measurements

    Science.gov (United States)

    1970-06-29

    obvious %ngle dependance between 15 to 85 degraes and, appear to be only slightly dependent of frequency; showing an approximate 2 db difference in mean... dependance . between 15 to 85 degrees and indicates a slight frequency dependance of 2 db over the frequency rang3e. The major reflected energy is from the...the low CONFIDENTIAL 10 NUSL Tech Memo 2211-023-70 CONFIDENTIAL sound v Locity sediment, resulting in significant angular dependance of bottom Loss at

  17. Density dependent catchability in bottom trawl surveys

    OpenAIRE

    Aglen, Asgeir; Engås, Arill; Godø, Olav Rune; McCallum, Barry R.; Stansbury, Don; Walsh, Stephen J.

    1997-01-01

    Fish form schools, layer or patches in which the individual fish's behaviour is not independent of its neighbours movements. On the other hand, at low densities fish may have the freedom to act as single individuals independently of what other fish are doing. Potentially, if these contrasts occur in nature, they may give rise to behavioural differences of fish in front of the trawl at high and low densities with successive effects on catchability and bottom trawl indices of stock ...

  18. A dynamic analysis of the radiation excitation from the activation of a current collecting system in space

    Science.gov (United States)

    Wang, J.; Hastings, D. E.

    1991-01-01

    Current collecting systems moving in the ionosphere will induce electromagnetic wave radiation. The commonly used static analysis is incapable of studying the situation when such systems undergo transient processes. A dynamic analysis has been developed, and the radiation excitation processes are studied. This dynamic analysis is applied to study the temporal wave radiation from the activation of current collecting systems in space. The global scale electrodynamic interactions between a space-station-like structure and the ionospheric plasma are studied. The temporal evolution and spatial propagation of the electric wave field after the activation are described. The wave excitations by tethered systems are also studied. The dependencies of the temporal Alfven wave and lower hybrid wave radiation on the activation time and the space system structure are discussed. It is shown that the characteristics of wave radiation are determined by the matching of two sets of characteristic frequencies, and a rapid change in the current collection can give rise to substantial transient radiation interference. The limitations of the static and linear analysis are examined, and the condition under which the static assumption is valid is obtained.

  19. Optimal Design of Round Bottomed Triangle Channels

    Directory of Open Access Journals (Sweden)

    Ayman T. Hameed

    2013-05-01

    Full Text Available     In optimal design concept, the geometric dimensions of a channel cross-section are determined in a manner to minimize the total construction costs. The Direct search optimization method by using MATALAB is used to solve the resulting channel optimization models for a specified flow rate, roughness coefficient and longitudinal slope. The developed optimization models are applied to design the round bottomed triangle channel and trapezoidal channels to convey a given design flow considering various design scenarios However, it also can be extended to other shapes of channels. This method optimizes the total construction cost by minimizing the cross-sectional area and wetted perimeter per unit length of the channel. In the present study, it is shown that for all values of side slope, the total construction cost in the round bottomed triangle cross-section are less than those of trapezoidal cross-section for the same values of discharge. This indicates that less excavation and a lining are involved and therefore implies that the round bottomed triangle cross-section is more economical than trapezoidal cross-section.

  20. Characterization of the rapidly activating delayed rectifier potassium current, I (Kr), in HL-1 mouse atrial myocytes.

    Science.gov (United States)

    Toyoda, Futoshi; Ding, Wei-Guang; Zankov, Dimitar P; Omatsu-Kanbe, Mariko; Isono, Takahiro; Horie, Minoru; Matsuura, Hiroshi

    2010-06-01

    HL-1 is the adult murine cardiac cell line that can be passaged repeatedly in vitro without losing differentiated phenotype. The present study was designed to characterize the rapidly activating delayed rectifier potassium current, I (Kr), endogenously expressed in HL-1 cells using the whole-cell patch-clamp technique. In the presence of nisoldipine, depolarizing voltage steps applied from a holding potential of -50 mV evoked the time-dependent outward current, followed by slowly decaying outward tail current upon return to the holding potential. The amplitude of the current increased with depolarizations up to 0 mV but then progressively decreased with further depolarizations. The time-dependent outward current as well as the tail current were highly sensitive to block by E-4031 and dofetilide (IC(50) of 21.1 and 15.1 nM, respectively) and almost totally abolished by micromolar concentrations of each drug, suggesting that most of the outward current in HL-1 cells was attributable to I (Kr). The magnitude of I (Kr) available from HL-1 cells (18.1 +/- 1.5 pA pF(-1)) was sufficient for reliable measurements of various gating parameters. RT-PCR and Western blot analysis revealed the expression of alternatively spliced forms of mouse ether-a-go-go-related genes (mERG1), the full-length mERG1a and the N-terminally truncated mERG1b isoforms. Knockdown of mERG1 transcripts with small interfering RNA (siRNA) dramatically reduced I (Kr) amplitude, confirming the molecular link of mERG1 and I (Kr) in HL-1 cells. These findings demonstrate that HL-1 cells possess I (Kr) with properties comparable to those in native cardiac I (Kr) and provide an experimental model suitable for studies of I (Kr) channels.

  1. A Study on the Environmental Standard of Sediment on the Bottom of the Water

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Hee; Yoo, Hye Jin [Korea Environment Institute, Seoul (Korea)

    2000-12-01

    Sediment on the bottom of the water has been considered one of the water pollutants in the environmental management of Korea so treated as a management on pollutants, as you can see the examples in the dragging operation in the polluted sea area. To healthily maintain and conserve the water ecosystem including bottom living things in the water, sediment on the bottom of the water should be recognized as the independent medium, which should maintain the certain quality like the water, the atmosphere, and soil, rather than the source of water pollution. Such recognition means that the management of sediment on the bottom of the water should change the fragmentary goal, centered the post management focusing on the water management, to the ecosystematic goal including the bottom living things. In a point of the view, this study has a great significance to suggest not only the final goal for the management of sediment on the bottom of the water but also the necessity of developing the environmental standard of the sediment on the bottom of the water, which is a standard of the management or judgment in the actual managing the sediment on the bottom of the water - an estimation on the pollution of sediment, a removal of the polluted sediment, a purification of sediment, and an abandonment of the dragged sediment -, and the development measures. Considering the situation that even the basic scheme related to the management of sediment is not prepared in the Government level, the concept of the environmental standard of sediment, the foreign example of the environmental standard of sediment, the current state of the domestic sediment pollution, and the development scheme of the environmental standard in this study must be the important foundation to establish the management system of sediment in the Government level. 121 refs., 10 figs., 45 tabs.

  2. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

    2005-01-01

    and to verify whether nonlinear control is needed. Finally a controller based on single loop theory is used to analyse if input constraints become active when rejecting transient behaviour from the disturbance steam flow. The model analysis shows large variations in system gains at steady state as function...... supported by a dynamical decoupling. The results indicate that input constraints will become active when the controller responds to transients in the steam flow disturbance. For this reason an MPC (model predictive control) strategy capable of handling constraints on states and control signals should...... the interactions in the system are inspected to analyse potential benefit from using a multivariable control strategy in favour of the current strategy based on single loop theory. An analysis of the nonlinear model is carried out to further determine the nonlinear characteristics of the boiler system...

  3. Damage process due to corrosion of reinforcement bars - Current and future activities -

    Energy Technology Data Exchange (ETDEWEB)

    Raupach, M.; Warkus, J. [Institute for Building Materials Research of Aachen University (ibac), Schinkelstr. 3, 52062 Aachen (Germany); Gulikers, J. [Research Department, Bouwdienst Rijkswaterstaat, P.O. Box 2 00 00, 3502 LA Utrecht (Netherlands)

    2006-08-15

    Against the background of huge costs for maintenance and repair it would be helpful to have a tool to assess the remaining life time of concrete structures. Deterioration is often caused by reinforcement corrosion and research projects have been carried out to develop models for the time-dependent progress of the degradation. Although these projects have resulted in several steps forward, further work is still needed. This paper presents two actual research activities which deal with modeling of reinforcement corrosion: the first one is the RILEM Technical Committee MAI, the second is a German joint research project. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

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

    DEFF Research Database (Denmark)

    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....

  5. Active penetration of Trypanosoma cruzi into host cells: historical considerations and current concepts

    Science.gov (United States)

    de Souza, Wanderley; de Carvalho, Tecia M. Ulisses

    2013-01-01

    In the present short review, we analyze past experiments that addressed the interactions of intracellular pathogenic protozoa (Trypanosoma cruzi, Toxoplasma gondii, and Plasmodium) with host cells and the initial use of the term active penetration to indicate that a protozoan “crossed the host cell membrane, penetrating into the cytoplasm.” However, the subsequent use of transmission electron microscopy showed that, for all of the protozoans and cell types examined, endocytosis, classically defined as involving the formation of a membrane-bound vacuole, took place during the interaction process. As a consequence, the recently penetrated parasites are always within a vacuole, designated the parasitophorous vacuole (PV). PMID:23355838

  6. Bottom-Tau Yukawa Unification in the Next-to-Minimal Supersymmetric Standard Model

    CERN Document Server

    Allanach, Benjamin C

    1994-01-01

    We discuss the unification of the bottom quark and tau lepton Yukawa couplings within the framework of the next-to-minimal supersymmetric standard model. We compare the allowed regions of the $m_t$-$\\tan \\beta$ plane to those in the minimal supersymmetric standard model, and find that over much of the parameter space the deviation between the predictions of two models is small, and nearly always much less than the effect of current theoretical and experimental uncertainties in the bottom quark mass and the strong coupling constant. However over some regions of parameter space top-bottom Yukawa unification cannot be achieved. We also discuss the scaling of the light fermion masses and mixing angles, and show that to within current uncertainties the results of recent texture analyses performed for the minimal model also apply to the next-to-minimal model.

  7. Expanding current knowledge on the chemical composition and antioxidant activity of the genus Lactarius.

    Science.gov (United States)

    Vieira, Vanessa; Barros, Lillian; Martins, Anabela; Ferreira, Isabel C F R

    2014-12-10

    Despite the presence of toxic compounds in inedible mushrooms, the question whether the chemical nutrients and non-nutrients compositions in edible and inedible Lactarius species are similar remains unanswered. To answer this question, Lactarius citriolens Pouzar and Lactarius turpis (Weinm.) Fr., two inedible species, were studied in order to obtain information about their chemical composition and bioactivity. Free sugars, fatty acids, tocopherols, organic and phenolic acids were analysed by chromatographic techniques coupled to different detectors. L. citriolens and L. turpis methanolic extracts were tested regarding antioxidant potential (reducing power, radical scavenging activity and lipid peroxidation inhibition). The composition of macronutrients varied among the two species, but the profiles were similar between them and among other Lactarius species; L. citriolens gave the highest energy contribution, saturated fatty acids and organic acids, while the L. turpis sample was richer in free sugars, mono- and polyunsaturated fatty acids, tocopherols and phenolic compounds. L. turpis methanolic extract showed the highest antioxidant activity. The absence of hepatoxicity of the methanolic extracts was confirmed in porcine liver primary cells (in vitro conditions). The present study provided new information about wild L. citriolens and L. turpis, comparing their chemical composition and antioxidant properties with other Lactarius species, and expanding the knowledge about this genus.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    , NS5806. METHODS AND RESULTS: Isolated canine ventricular myocytes and coronary-perfused wedge preparations were used. Whole-cell patch-clamp studies showed that NS5806 (10 microM) increased peak I(to) at +40 mV by 79 +/- 4% (24.5 +/- 2.2 to 43.6 +/- 3.4 pA/pF, n = 7) and slowed the time constant......, but not in the 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 phenotype in wedges from both ventricles. NS5806 induced BrS in 4/6 right and 2/10 left ventricular wedge preparations. CONCLUSION: The I(to) activator NS5806 recapitulates the electrographic and arrhythmic manifestation of BrS, providing evidence in support of its pivotal role in the genesis of the disease...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    CERN Document Server

    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...

  11. Medicinal significance, pharmacological activities, and analytical aspects of solasodine: A concise report of current scientific literature

    Directory of Open Access Journals (Sweden)

    Kanika Patel

    2013-01-01

    Full Text Available Alkaloids are well known phytoconstituents for their diverse pharmacological properties. Alkaloids are found in all plant parts like roots, stems, leaves, flowers, fruits and seeds. Solasodine occurs as an aglycone part of glycoalkloids, which is a nitrogen analogue to sapogenins. Solanaceae family comprises of a number of plants with variety of natural products of medicinal significance mainly steroidal lactones, glycosides, alkaloids and flavanoids. It is a steroidal alkaloid based on a C27 cholestane skeleton. Literature survey reveals that solasodine has diuretic, anticancer, antifungal, cardiotonic, antispermatogenetic, antiandrogenic, immunomodulatory, antipyretic and various effects on central nervous system. Isolation and quantitative determination was achieved by several analytical techniques. Present review highlights the pharmacological activity of solasodine, with its analytical and tissue culture techniques, which may be helpful to the researchers to develop new molecules for the treatment of various disorders in the future.

  12. The origins and current status of behavioral activation treatments for depression.

    Science.gov (United States)

    Dimidjian, Sona; Barrera, Manuel; Martell, Christopher; Muñoz, Ricardo F; Lewinsohn, Peter M

    2011-01-01

    The past decade has witnessed a resurgence of interest in behavioral interventions for depression. This contemporary work is grounded in the work of Lewinsohn and colleagues, which laid a foundation for future clinical practice and science. This review thus summarizes the origins of a behavioral model of depression and the behavioral activation (BA) approach to the treatment and prevention of depression. We highlight the formative initial work by Lewinsohn and colleagues, the evolution of this work, and related contemporary research initiatives, such as that led by Jacobson and colleagues. We examine the diverse ways in which BA has been investigated over time and its emerging application to a broad range of populations and problems. We close with reflections on important directions for future inquiry.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Levamisole-activated single-channel currents from muscle of the nematode parasite Ascaris suum.

    Science.gov (United States)

    Robertson, S. J.; Martin, R. J.

    1993-01-01

    1. The patch-clamp technique was used to examine levamisole-activated channels in muscle vesicles from Ascaris suum. Cell-attached and isolated inside-out patches were used. 2. Levamisole (1-90 microM), applied to the extracellular surface, activated channels which had apparent mean open-times in the range 0.80-2.85 ms and linear I/V relationships with conductances in the range 19-46 pS. Ion-replacement experiments showed the channels to be cation selective. 3. The kinetics of the channels were analysed. Generally open- and closed-time distributions were best fitted by two, and three exponentials respectively, indicating the presence of at least two open states and at least three closed states. The distributions of burst-times were best-fitted by two exponentials. 4. Channel open- and burst-times were voltage-sensitive: at low levamisole concentrations (1-10 microM), they increased with hyperpolarization. At higher concentrations of levamisole (30 microM and 90 microM) flickering channel-block was observed at hyperpolarized potentials. Using a simple channel-block model, values for the blocking dissociation constant, KB were determined as 123 microM at -50 mV, 46 microM at -75 mV and 9.4 microM at -100 mV. 5. At the higher concentration of levamisole (30 microM and 90 microM) long closed-times separating 'clusters' of bursts were observed, at both hyperpolarized and depolarized membrane potentials and this was interpreted as desensitization. PMID:7679027

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

    Energy Technology Data Exchange (ETDEWEB)

    Taxvig, Camilla, E-mail: camta@food.dtu.dk [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg (Denmark); Hadrup, Niels; Boberg, Julie; Axelstad, Marta [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg (Denmark); Bossi, Rossana [Department of Environmental Science, Aarhus University, DK-4000 Roskilde (Denmark); Bonefeld-Jørgensen, Eva Cecilie [Department of Public Health, University of Aarhus, DK-8000 Aarhus C (Denmark); Vinggaard, Anne Marie [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg (Denmark)

    2013-11-01

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  19. Bottom Trawl Survey Protocol Development (HB0706, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Cruise objectives include: 1) Investigate performance characteristics of new research bottom trawl; 2) Develop standard operating procedures for the NEFSC Bottom...

  20. Nitric oxide/cGMP/PKG signaling pathway activated by M1-type muscarinic acetylcholine receptor cascade inhibits Na+-activated K+ currents in Kenyon cells.

    Science.gov (United States)

    Hasebe, Masaharu; Yoshino, Masami

    2016-06-01

    The interneurons of the mushroom body, known as Kenyon cells, are essential for the long-term memory of olfactory associative learning in some insects. Some studies have reported that nitric oxide (NO) is strongly related to this long-term memory in Kenyon cells. However, the target molecules and upstream and downstream NO signaling cascades are not completely understood. Here we analyzed the effect of the NO signaling cascade on Na(+)-activated K(+) (KNa) channel activity in Kenyon cells of crickets (Gryllus bimaculatus). We found that two different NO donors, S-nitrosoglutathione (GSNO) and S-nitroso-N-acetyl-dl-penicillamine (SNAP), strongly suppressed KNa channel currents. Additionally, this inhibitory effect of GSNO on KNa channel activity was diminished by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase (sGC), and KT5823, an inhibitor of protein kinase G (PKG). Next, we analyzed the role of ACh in the NO signaling cascade. ACh strongly suppressed KNa channel currents, similar to NO donors. Furthermore, this inhibitory effect of ACh was blocked by pirenzepine, an M1 muscarinic ACh receptor antagonist, but not by 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (4-DAMP) and mecamylamine, an M3 muscarinic ACh receptor antagonist and a nicotinic ACh receptor antagonist, respectively. The ACh-induced inhibition of KNa channel currents was also diminished by the PLC inhibitor U73122 and the calmodulin antagonist W-7. Finally, we found that ACh inhibition was blocked by the nitric oxide synthase (NOS) inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME). These results suggested that the ACh signaling cascade promotes NO production by activating NOS and NO inhibits KNa channel currents via the sGC/cGMP/PKG signaling cascade in Kenyon cells.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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.

  3. The calcium current activated by T cell receptor and store depletion in human lymphocytes is absent in a primary immunodeficiency.

    Science.gov (United States)

    Partiseti, M; Le Deist, F; Hivroz, C; Fischer, A; Korn, H; Choquet, D

    1994-12-23

    Stimulation of antigen receptors of lymphocytes triggers a transitory release of Ca2+ from internal stores and the opening of a transmembrane Ca2+ conductive pathway. The latter underlies the sustained increase of intracellular free calcium concentration, and it seems to be a key event in the Ca(2+)-dependent biochemical cascade leading to T cell proliferation. Alternatively, pharmacological depletion of internal stores by itself activates Ca2+ influx. This has led to the hypothesis that antigen-triggered Ca2+ influx is secondary to Ca2+ release from internal stores. However, the precise relationship between antigen and Ca2+ release-activated Ca2+ currents remains unclear, particularly since neither of them has been electrophysiologically recorded in normal lymphocytes. Using the whole-cell and the perforated configurations of the patch clamp technique on peripheral blood lymphocytes, we found that a low amplitude Ca(2+)-selective current was triggered when intracellular stores were depleted by stimuli such as the intracellular perfusion of inositol triphosphate or thapsigargin and the extracellular perfusion of ionomycin. A similar current was elicited by the cross-linking of the T cell receptor-CD3 complex. This current displayed an inward rectification below 0 mV and was completely blocked by the divalent cation Cd2+. It was very selective for Ca2+ over Na+ and insensitive to changes in chloride concentration. The physiological relevance of this conductance was investigated with the analysis of abnormal Ca2+ signaling in lymphocytes from a patient suffering from a primary immunodeficiency associated with a defective T cell proliferation. Using fura-2 video imaging, an absence of Ca2+ influx was established in the patient's lymphocytes, whereas the Ca2+ release from internal stores was normal. This was the case whether cells were stimulated physiologically through their antigen receptors or with store depleting pharmacological agents. Most importantly, no Ca(2

  4. Overflow dynamics and bottom water formation in the western Ross Sea: Influence of tides

    Science.gov (United States)

    Wang, Q.; Danilov, S.; Hellmer, H. H.; SchröTer, J.

    2010-10-01

    The tidal impact on overflow dynamics and bottom water production in the western Ross Sea is studied with the Finite Element Ocean Model, which allows embedding a mesh with 0.5 km resolution in a coarse resolution (30 km) setup without nesting. The simulated overflow properties inside and downstream of the western Ross Sea are described. The overflow exhibits pronounced variability at both daily and spring-neap tidal time scales in the western Ross Sea. Tides increase mixing over both the outer shelf and upper slope there. Plume jets are shaped by tidal currents at a bathymetric bend west of the Drygalski Trough mouth, descending rapidly and supplying the bottom water. A fraction of shelf water remains over the shelf and propagates westward from the Ross Sea, but it does not contribute significantly to bottom water formation because of energetic mixing over the upper slope. Compared to a simulation without tidal forcing, tides (with the major K1 and O1 constituents) increase the outflow rate over the continental slope off Cape Adare by about 70%. A set of sensitivity experiments show that the rate of bottom water production is not a monotonic function of the tidal currents amplitude. Tidal forcing with intermediate strength leads to the most efficient bottom water formation.

  5. Oxygen reduction activity of carbon fibers cathode, and application for current generation from the NAD+ and NADH recycling reaction

    Directory of Open Access Journals (Sweden)

    H. Maeda

    2012-03-01

    Full Text Available Carbon fibers treated at 700 oC for 10 min were found to have O2 reduction activity when being used as a cathode. The special type of partition combined with both cationic and anionic exchange membranes was applied between anode cell and cathode cell in order to use a highly acidic solution such as 0.5 M H2SO4 as an electrolyte of the cathode cell for increasing the efficiency of O2 reduction activity. The current generation from NAD+ and NADH recycling system combined with D-gluconolactone production from 500 mg of D-glucose was performed by applying only carbon fibers for both anode and cathode. The total current volume obtained was 81.4 mAh during the reaction for 10 h, and the current efficiency was 93%. One gram of carbon fibers was pressed with Nafion paste on a piece of carbon paper(area : 50 mm×50mm with heating to prepare the cathode, and this construct was combined with conventional fuel cell. The power density was 3.6 mW/cm2, and the total power volume was calculated to be 90 mW per 1 g of carbon fibers.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. On the current solar magnetic activity in the light of its behaviour during the Holocene

    CERN Document Server

    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...

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

    Science.gov (United States)

    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.

  10. Active surveillance for prostate cancer: current evidence and contemporary state of practice.

    Science.gov (United States)

    Tosoian, Jeffrey J; Carter, H Ballentine; Lepor, Abbey; Loeb, Stacy

    2016-04-01

    Prostate cancer remains one of the most commonly diagnosed malignancies worldwide. Early diagnosis and curative treatment seem to improve survival in men with unfavourable-risk cancers, but significant concerns exist regarding the overdiagnosis and overtreatment of men with lower-risk cancers. To this end, active surveillance (AS) has emerged as a primary management strategy in men with favourable-risk disease, and contemporary data suggest that use of AS has increased worldwide. Although published surveillance cohorts differ by protocol, reported rates of metastatic disease and prostate-cancer-specific mortality are exceedingly low in the intermediate term (5-10 years). Such outcomes seem to be closely associated with programme-specific criteria for selection, monitoring, and intervention, suggesting that AS--like other management strategies--could be individualized based on the level of risk acceptable to patients in light of their personal preferences. Additional data are needed to better establish the risks associated with AS and to identify patient-specific characteristics that could modify prognosis.

  11. Bottom Topographic Changes of Poyang Lake During Past Decade Using Multi-temporal Satellite Images

    Science.gov (United States)

    Zhang, S.

    2015-12-01

    Poyang Lake, as a well-known international wetland in the Ramsar Convention List, is the largest freshwater lake in China. It plays crucial ecological role in flood storage and biological diversity. Poyang Lake is facing increasingly serious water crises, including seasonal dry-up, decreased wetland area, and water resource shortage, all of which are closely related to progressive bottom topographic changes over recent years. Time-series of bottom topography would contribute to our understanding of the lake's evolution during the past several decades. However, commonly used methods for mapping bottom topography fail to frequently update quality bathymetric data for Poyang Lake restricted by weather and accessibility. These deficiencies have limited our ability to characterize the bottom topographic changes and understanding lake erosion or deposition trend. To fill the gap, we construct a decadal bottom topography of Poyang Lake with a total of 146 time series medium resolution satellite images based on the Waterline Method. It was found that Poyang Lake has eroded with a rate of -14.4 cm/ yr from 2000 to 2010. The erosion trend was attributed to the impacts of human activities, especially the operation of the Three Gorge Dams, sand excavation, and the implementation of water conservancy project. A decadal quantitative understanding bottom topography of Poyang Lake might provide a foundation to model the lake evolutionary processes and assist both researchers and local policymakers in ecological management, wetland protection and lake navigation safety.

  12. Effects of weak transcranial Alternating Current Stimulation on brain activity – a review of known mechanisms from animal studies

    Directory of Open Access Journals (Sweden)

    Davide eReato

    2013-10-01

    Full Text Available Rhythmic neuronal activity is ubiquitous in the human brain. These rhythms originate from a variety of different network mechanisms, which give rise to a wide-ranging spectrum of oscillation frequencies. In the last few years an increasing number of clinical research studies have explored transcranial alternating current stimulation (tACS with weak current as a tool for affecting brain function. The premise of these interventions is that tACS will interact with ongoing brain oscillations. However, the exact mechanisms by which weak currents could affect neuronal oscillations at different frequency bands are not well known and this, in turn, limits the rational optimization of human experiments. Here we review the available in vitro and in vivo animal studies that attempt to provide mechanistic explanations. The findings can be summarized into a few generic principles, such as periodic modulation of excitability, shifts in spike timing, modulation of firing rate, and shifts in the balance of excitation and inhibition. These effects result from weak but simultaneous polarization of a large number of neurons. Whether this can lead to an entrainment or a modulation of brain oscillations, or whether AC currents have no effect at all, depends entirely on the specific dynamic that gives rise to the different brain rhythms, as discussed here for slow wave oscillations (~1 Hz and gamma oscillations (~30 Hz. We conclude with suggestions for further experiments to investigate the role of AC stimulation for other physiologically relevant brain rhythms.

  13. Current distribution in skeletal muscle activated by functional electrical stimulation: image-series formulation and isometric recruitment curve.

    Science.gov (United States)

    Livshitz, L M; Einziger, P D; Mizrahi, J

    2000-01-01

    The present work develops an analytical model that allows one to estimate the current distribution within the whole muscle and the resulting isometric recruitment curve (IRC). The quasistatic current distribution, expressed as an image series, i.e., a collection of properly weighted and shifted point-source responses, outlines an extension for more than three layers of the classical image theory in conductive plane-stratified media. Evaluation of the current distribution via the image series expansions requires substantially less computational time than the standard integral representation. The expansions use a unique recursive representation for Green's function, that is a generic characteristic of the stratification. This approach permits one to verify which of the tissue electrical properties are responsible for the current density distribution within the muscle, and how significant their combinations are. In addition, the model permits one to study the effect of different electrode placement on the shape and the magnitude of the potential distribution. A simple IRC model was used for parameter estimation and model verification by comparison with experimentally obtained isometric recruitment curves. Sensitivity of the model to different parameters such as conductivity of the tissues and activation threshold was verified. The resulting model demonstrated characteristic features that were similar to those of experimentally obtained data. The model also quantitatively confirmed the differences existing between surface (transcutaneous) and implanted (percutaneous) electrode stimulation.

  14. 46 CFR 171.106 - Wells in double bottoms.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Wells in double bottoms. 171.106 Section 171.106... PERTAINING TO VESSELS CARRYING PASSENGERS Additional Subdivision Requirements § 171.106 Wells in double bottoms. (a) This section applies to each vessel that has a well installed in a double bottom required...

  15. On the Current Solar Magnetic Activity using Its Behavior During the Holocene

    Science.gov (United States)

    Inceoglu, Fadil; Simoniello, Rosaria; Faurschou Knudsen, Mads; Karoff, Christoffer; Olsen, Jesper; Turck-Chieze, Sylvaine

    2016-07-01

    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 behavior of the open solar magnetic field over the Holocene period. Using the Greenland Ice Core Project (GRIP) ^{10}Be and IntCal13 ^{14}C records for the overlapping time period spanning between ˜1650 AD to 6600 BC, we first reconstructed the solar modulation potentials and subsequently investigate the statistics of peaks and dips simultaneously occurring in the two SMP reconstructions. Based on the distribution of these events, we propose a method to identify grand minima and maxima periods. We then aim at comparing the Sun's large-scale magnetic field behavior 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 ˜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.

  16. Current state of ESCO activities in Asia: ESCO industry development programs and future tasks in Asian countries

    Energy Technology Data Exchange (ETDEWEB)

    Murakoshi, Chiharu; Nakagami, Hidetoshi (Jyukankyo Research Inst. (Japan))

    2009-07-01

    In Japan and other Asian countries, ESCO markets are under formation. Introduction of ESCOs to Asia took place in the 1990s. A vigorous ESCO market is already forming in Japan, South Korea, China, and Thailand. Also, in Malaysia, and the Philippines, ESCO market development is proceeding. How did these countries introduce ESCO industries? What kind of activities are being carried out, and what are future tasks? As a first step in implementing ESCO development programs, developed countries have used government support, while emerging countries have co-operated with international organisations. By classifying the types of programs and examining activities currently under way, we can understand necessary conditions for developing an ESCO industry. When we classify programs of various countries, we see that most countries implement the same kinds of measures. However, the results vary. Some countries are progressing with market development, while others have not reached the point of market formation. Analysis of factors leading to these variations is important to the future development of ESCO industries. In this paper, we describe the current state of ESCO activities in Japan and emerging countries, and we examine ESCO development programs of each country. In particular, by comparing measures taken in countries with successful ESCO market development, such as Japan, China, Thailand and India with those still trying to develop ESCO markets, such as Malaysia, and the Philippines, we analyse factors leading to success, and we illuminate future tasks for each country.

  17. The persistent sodium current generates pacemaker activities in the central pattern generator for locomotion and regulates the locomotor rhythm.

    Science.gov (United States)

    Tazerart, Sabrina; Vinay, Laurent; Brocard, Frédéric

    2008-08-20

    Rhythm generation in neuronal networks relies on synaptic interactions and pacemaker properties. Little is known about the contribution of the latter mechanisms to the integrated network activity underlying locomotion in mammals. We tested the hypothesis that the persistent sodium current (I(NaP)) is critical in generating locomotion in neonatal rodents using both slice and isolated spinal cord preparations. After removing extracellular calcium, 75% of interneurons in the area of the central pattern generator (CPG) for locomotion exhibited bursting properties and I(NaP) was concomitantly upregulated. Putative CPG interneurons such as commissural and Hb9 interneurons also expressed I(NaP)-dependent (riluzole-sensitive) bursting properties. Most bursting cells exhibited a pacemaker-like behavior (i.e., burst frequency increased with depolarizing currents). Veratridine upregulated I(NaP), induced riluzole-sensitive bursting properties, and slowed down the locomotor rhythm. This study provides evidence that I(NaP) generates pacemaker activities in CPG interneurons and contributes to the regulation of the locomotor activity.

  18. Mitochondrial uncoupler FCCP activates proton conductance but does not block store-operated Ca(2+) current in liver cells.

    Science.gov (United States)

    To, Minh-Son; Aromataris, Edoardo C; Castro, Joel; Roberts, Michael L; Barritt, Greg J; Rychkov, Grigori Y

    2010-03-15

    Uncouplers of mitochondrial oxidative phosphorylation, including carbonilcyanide p-triflouromethoxyphenylhydrazone (FCCP) and carbonilcyanide m-cholorophenylhydrazone (CCCP), are widely used in experimental research to investigate the role of mitochondria in cellular function. Unfortunately, it is very difficult to interpret the results obtained in intact cells using FCCP and CCCP, as these agents not only inhibit mitochondrial potential, but may also affect membrane potential and cell volume. Here we show by whole-cell patch clamping that in primary rat hepatocytes and H4IIE liver cells, FCCP induced large proton currents across the plasma membrane, but did not activate any other observable conductance. In intact hepatocytes FCCP inhibits thapsigargin-activated store-operated Ca(2+) entry, but in patch clamping under the conditions of strong Ca(2+) buffering it has no effect on store-operated Ca(2+) current (I(SOC)). These results indicate that there is no direct connection between mitochondria and activation of I(SOC) in liver cells and support the notion of indirect regulation of I(SOC) by mitochondrial Ca(2+) buffering.

  19. Transport of Antarctic bottom water through the Kane Gap, tropical NE Atlantic Ocean

    NARCIS (Netherlands)

    Morozov, E.G.; Tarakanov, R.Y.; van Haren, H.

    2013-01-01

    We study low-frequency properties of the Antarctic Bottom Water (AABW) flow through the Kane Gap (9° N) in the Atlantic Ocean. The measurements in the Kane Gap include five visits with CTD (Conductivity-Temperature-Depth) sections in 2009–2012 and a year-long record of currents on a mooring using th

  20. Bottom-up GGM algorithm for constructing multiple layered hierarchical gene regulatory networks

    Science.gov (United States)

    Multilayered hierarchical gene regulatory networks (ML-hGRNs) are very important for understanding genetics regulation of biological pathways. However, there are currently no computational algorithms available for directly building ML-hGRNs that regulate biological pathways. A bottom-up graphic Gaus...

  1. Persistent and energetic bottom-trapped topographic Rossby waves observed in the southern South China Sea.

    Science.gov (United States)

    Shu, Yeqiang; Xue, Huijie; Wang, Dongxiao; Chai, Fei; Xie, Qiang; Cai, Shuqun; Chen, Rongyu; Chen, Ju; Li, Jian; He, Yunkai

    2016-04-14

    Energetic fluctuations with periods of 9-14 days below a depth of 1400 m were observed in the southern South China Sea (SCS) from 5 years of direct measurements. We interpreted such fluctuations as topographic Rossby waves (TRWs) because they obey the dispersion relation. The TRWs persisted from May 24, 2009 to August 23, 2013, and their bottom current speed with a maximum of ~10 cm/s was one order of magnitude greater than the mean current and comparable to the tidal currents near the bottom. The bottom-trapped TRWs had an approximate trapping depth of 325 m and reference wavelength of ~82 km, which were likely excited by eddies above. Upper layer current speed that peaked approximately every 2 months could offer the energy sources for the persistent TRWs in the southern SCS. Energetic bottom-trapped TRWs may have a comparable role in deep circulation to tides in areas with complex topography.

  2. Process identification and model development of contaminant transport in MSWI bottom ash

    NARCIS (Netherlands)

    Dijkstra, J.J.; Sloot, van der H.A.; Comans, R.N.J.

    2002-01-01

    In this work we investigate to what extent we are able to predict experimental data on column leaching of heavy metals from municipal solid waste incinerator (MSWI) bottom ash, using the current knowledge on processes controlling aqueous heavy metal concentrations in combination with a multicomponen

  3. Designing the organisational chart from the bottom

    DEFF Research Database (Denmark)

    Giangreco, Antonio; Carugati, Andrea

    and control. Marco had been called in because of his reputation for being an effective innovator with unconventional ideas for the public sector. Previously, during his long career in the civil service, Marco proved to be an effective leader and negotiator who was open to other people's view points. He would...... share any significant and final decisions with his employees, rather than merely imposing his own personal choice. After spending some time in the organisation, he put into action a bottom up method to redesign the structure of the HR department. He decided to temporarily suspend the existing internal...

  4. Rankine bottoming cycle safety analysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowski, G.A.

    1980-02-01

    Vector Engineering Inc. conducted a safety and hazards analysis of three Rankine Bottoming Cycle Systems in public utility applications: a Thermo Electron system using Fluorinal-85 (a mixture of 85 mole % trifluoroethanol and 15 mole % water) as the working fluid; a Sundstrand system using toluene as the working fluid; and a Mechanical Technology system using steam and Freon-II as the working fluids. The properties of the working fluids considered are flammability, toxicity, and degradation, and the risks to both plant workers and the community at large are analyzed.

  5. Mechanical and leaching properties of blended systems containing OPC and incinerator bottom ash

    Energy Technology Data Exchange (ETDEWEB)

    Onori, R.; Polettini, A.; Pomi, R. [Rome Univ. (Italy). Dept. of Hydraulics, Transportation and Roads

    2010-07-01

    Chemical and mechanical activation processes were applied to improve the reactivity of incinerator bottom ash in Portland cement mixtures. Sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium chloride (CaCI{sub 2}) and calcium sulfate (CaSO{sub 4}) activators were used in experiments conducted to determine bottom ash content, activator type, and activator dosages for varying amounts of cement and bottom ash. The study evaluated the evolution of mechanical strength and the leaching behaviour of both major and trace elements from the activated bottom ash and Portland cement mixtures. Results of the study showed that the use of CaCI{sub 2} improved the hydration process in the mixtures. A positive effect on mechanical strength was noted when CaSO{sub 4} was used as an activator. Trace metals were efficiently immobilized within the hardened materials for all the tested activators. Geochemical modelling was used to determine the main hydration phases of the leaching solutions. No mineral phases were identified as potential solubility-controlling solids. Results of the study indicated the presence of heavy metals as complex phase assemblages in the hardened materials. 40 refs., 2 tabs., 8 figs.

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

    OpenAIRE

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

    2016-01-01

    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 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...

  7. The magnitudes of hyperpolarization-activated and low-voltage-activated potassium currents co-vary in neurons of the ventral cochlear nucleus.

    Science.gov (United States)

    Cao, Xiao-Jie; Oertel, Donata

    2011-08-01

    In the ventral cochlear nucleus (VCN), neurons have hyperpolarization-activated conductances, which in some cells are enormous, that contribute to the ability of neurons to convey acoustic information in the timing of their firing by decreasing the input resistance and speeding-up voltage changes. Comparisons of the electrophysiological properties of neurons in the VCN of mutant mice that lack the hyperpolarization-activated cyclic nucleotide-gated channel α subunit 1 (HCN1(-/-)) (Nolan et al. 2003) with wild-type controls (HCN1(+/+)) and with outbred ICR mice reveal that octopus, T stellate, and bushy cells maintain their electrophysiological distinctions in all strains. Hyperpolarization-activated (I(h)) currents were smaller and slower, input resistances were higher, and membrane time constants were longer in HCN1(-/-) than in HCN1(+/+) in octopus, bushy, and T stellate cells. There were significant differences in the average magnitudes of I(h), input resistances, and time constants between HCN1(+/+) and ICR mice, but the resting potentials did not differ between strains. I(h) is opposed by a low-voltage-activated potassium (I(KL)) current in bushy and octopus cells, whose magnitudes varied widely between neuronal types and between strains. The magnitudes of I(h) and I(KL) were correlated across neuronal types and across mouse strains. Furthermore, these currents balanced one another at the resting potential in individual cells. The magnitude of I(h) and I(KL) is linked in bushy and octopus cells and varies not only between HCN1(-/-) and HCN1(+/+) but also between "wild-type" strains of mice, raising the question to what extent the wild-type strains reflect normal mice.

  8. Physical activity in relation to all-site and lung cancer incidence and mortality in current and former smokers.

    Science.gov (United States)

    Alfano, Catherine M; Klesges, Robert C; Murray, David M; Bowen, Deborah J; McTiernan, Anne; Vander Weg, Mark W; Robinson, Leslie A; Cartmel, Brenda; Thornquist, Mark D; Barnett, Matt; Goodman, Gary E; Omenn, Gilbert S

    2004-12-01

    Increased physical activity has been associated with a reduction in the incidence and mortality from all-site cancer and some site-specific cancers in samples of primarily nonsmoking individuals; however, little is known about whether physical activity is associated with similar risk reductions among smokers and ex-smokers. This study examined physical activity in relation to all-site cancer and lung cancer incidence and mortality in a sample of current and former smokers (n = 7,045; 59% male; 95% Caucasian; mean age, 63 years) drawn from the beta-Carotene and Retinol Efficacy Trial, a lung cancer chemoprevention trial. Hazard rate ratios and 95% confidence intervals associated with a 1 SD increase in physical activity were 0.86 (0.80-0.94) for all-site cancer only among men, 0.84 (0.69-1.03) for lung cancer only for younger participants, 0.75 (0.59-0.94) for cancer mortality among younger participants and 0.68 (0.53-0.89) among women, and 0.69 (0.53-0.90) for lung cancer mortality only among women. These results suggest that incidence may be more attenuated by physical activity for men and mortality more attenuated for women. Effects may be more pronounced for younger people and may differ inconsistently by pack-years of smoking. Physical activity may play a role in reducing cancer risk and mortality among those with significant tobacco exposure. Prospective studies using more sophisticated measures of physical activity assessed at multiple time points during follow-up are needed to corroborate these associations.

  9. Direct current (DC) resistivity and induced polarization (IP) monitoring of active layer dynamics at high temporal resolution

    DEFF Research Database (Denmark)

    Doetsch, Joseph; Ingeman-Nielsen, Thomas; Christiansen, Anders V.

    2015-01-01

    With permafrost thawing and changes in active layer dynamics induced by climate change, interactions between biogeochemical and thermal processes in the ground are of great importance. Here, active layer dynamics have been monitored using direct current (DC) resistivity and induced polarization (IP...... and subsurface temperatures supplemented the DC-IP measurements. A time-lapse DC-IP monitoring system has been acquiring at least six datasets per day on a 42-electrode profile with 0.5. m electrode spacing since July 2013. Remote control of the data acquisition system enables interactive adaptation...... of the measurement schedule, which is critically important to acquire data in the winter months, where extremely high contact resistances increase the demands on the resistivity meter. Data acquired during the freezing period of October 2013 to February 2014 clearly image the soil freezing as a strong increase...

  10. Roles of the magnetic field and electric current in thermally activated domain wall motion in a submicrometer magnetic strip with perpendicular magnetic anisotropy.

    Science.gov (United States)

    Emori, Satoru; Beach, Geoffrey S D

    2012-01-18

    We have experimentally studied micrometer-scale domain wall (DW) motion driven by a magnetic field and an electric current in a Co/Pt multilayer strip with perpendicular magnetic anisotropy. The thermal activation energy for DW motion, along with its scaling with the driving field and current, has been extracted directly from the temperature dependence of the DW velocity. The injection of DC current resulted in an enhancement of the DW velocity independent of the current polarity, but produced no measurable change in the activation energy barrier. Through this analysis, the observed current-induced DW velocity enhancement can be entirely and unambiguously attributed to Joule heating.

  11. Superoxide mediates direct current electric field-induced directional migration of glioma cells through the activation of AKT and ERK.

    Directory of Open Access Journals (Sweden)

    Fei Li

    Full Text Available Direct current electric fields (DCEFs can induce directional migration for many cell types through activation of intracellular signaling pathways. However, the mechanisms that bridge extracellular electrical stimulation with intracellular signaling remain largely unknown. In the current study, we found that a DCEF can induce the directional migration of U87, C6 and U251 glioma cells to the cathode and stimulate the production of hydrogen peroxide and superoxide. Subsequent studies demonstrated that the electrotaxis of glioma cells were abolished by the superoxide inhibitor N-acetyl-l-cysteine (NAC or overexpression of mitochondrial superoxide dismutase (MnSOD, but was not affected by inhibition of hydrogen peroxide through the overexpression of catalase. Furthermore, we found that the presence of NAC, as well as the overexpression of MnSOD, could almost completely abolish the activation of Akt, extracellular-signal-regulated kinase (Erk1/2, c-Jun N-terminal kinase (JNK, and p38, although only JNK and p38 were affected by overexpression of catalase. The presenting of specific inhibitors can decrease the activation of Erk1/2 or Akt as well as the directional migration of glioma cells. Collectively, our data demonstrate that superoxide may play a critical role in DCEF-induced directional migration of glioma cells through the regulation of Akt and Erk1/2 activation. This study provides novel evidence that the superoxide is at least one of the "bridges" coupling the extracellular electric stimulation to the intracellular signals during DCEF-mediated cell directional migration.

  12. Heavy Exotic Molecules with Charm and Bottom

    CERN Document Server

    Liu, Yizhuang

    2016-01-01

    We revisit the formation of pion-mediated heavy-light exotic molecules with both charm and bottom and their chiral partners under the general strictures of both heavy-quark and chiral symmetry. The chiral exotic partners with good parity formed using the $(0^+, 1^+)$ multiplet are about twice more bound than their primary exotic partners formed using the $(0^-,1^-)$ multiplet. The chiral couplings across the multiplets $(0^\\pm, 1^\\pm)$ cause the chiral exotic partners to unbind, and the primary exotic molecules to be about twice more bound, for $J\\leq 1$. Our multi-channel coupling results show that only the charm isosinglet exotic molecules with $J^{PC}=1^{++}$ binds, which we identify as the reported neutral $X(3872)$. Also, the bottom isotriplet exotic with $J^{PC}=1^{+-}$ binds, which we identify as a mixture of the reported charged exotics $Z^+_b(10610)$ and $Z^+_b(10650)$. The bound isosinglet with $J^{PC}=1^{++}$ is suggested as a possible neutral $X_b(10532)$ not yet reported.

  13. Charmed bottom baryon spectroscopy from lattice QCD

    CERN Document Server

    Brown, Zachary S; Meinel, Stefan; Orginos, Kostas

    2014-01-01

    We calculate the masses of baryons containing one, two, or three heavy quarks using lattice QCD. We consider all possible combinations of charm and bottom quarks, and compute a total of 36 different states with $J^P = \\frac12^+$ and $J^P = \\frac32^+$. We use domain-wall fermions for the up, down, and strange quarks, a relativistic heavy-quark action for the charm quarks, and nonrelativistic QCD for the bottom quarks. Our analysis includes results from two different lattice spacings and seven different pion masses. We perform extrapolations of the baryon masses to the continuum limit and to the physical pion mass using $SU(4|2)$ heavy-hadron chiral perturbation theory including $1/m_Q$ and finite-volume effects. For the 14 singly heavy baryons that have already been observed, our results agree with the experimental values within the uncertainties. We compare our predictions for the hitherto unobserved states with other lattice calculations and quark-model studies.

  14. Heavy exotic molecules with charm and bottom

    Science.gov (United States)

    Liu, Yizhuang; Zahed, Ismail

    2016-11-01

    We revisit the formation of pion-mediated heavy-light exotic molecules with both charm and bottom and their chiral partners under the general strictures of both heavy-quark and chiral symmetry. The chiral exotic partners with good parity formed using the (0+ ,1+) multiplet are about twice more bound than their primary exotic partners formed using the (0- ,1-) multiplet. The chiral couplings across the multiplets (0± ,1±) cause the chiral exotic partners to unbind, and the primary exotic molecules to be about twice more bound, for J ≤ 1. Our multi-channel coupling results show that only the charm isosinglet exotic molecules with JPC =1++ bind, which we identify as the reported neutral X (3872). Also, the bottom isotriplet exotic with JPC =1+- binds, which we identify as a mixture of the reported charged exotics Zb+ (10610) and Zb+ (10650). The bound isosinglet with JPC =1++ is suggested as a possible neutral Xb (10532) not yet reported.

  15. Bottom-up holographic approach to QCD

    Energy Technology Data Exchange (ETDEWEB)

    Afonin, S. S. [V. A. Fock Department of Theoretical Physics, Saint Petersburg State University, 1 ul. Ulyanovskaya, 198504 (Russian Federation)

    2016-01-22

    One of the most known result of the string theory consists in the idea that some strongly coupled gauge theories may have a dual description in terms of a higher dimensional weakly coupled gravitational theory — the so-called AdS/CFT correspondence or gauge/gravity correspondence. The attempts to apply this idea to the real QCD are often referred to as “holographic QCD” or “AdS/QCD approach”. One of directions in this field is to start from the real QCD and guess a tentative dual higher dimensional weakly coupled field model following the principles of gauge/gravity correspondence. The ensuing phenomenology can be then developed and compared with experimental data and with various theoretical results. Such a bottom-up holographic approach turned out to be unexpectedly successful in many cases. In the given short review, the technical aspects of the bottom-up holographic approach to QCD are explained placing the main emphasis on the soft wall model.

  16. Bottom-up holographic approach to QCD

    Science.gov (United States)

    Afonin, S. S.

    2016-01-01

    One of the most known result of the string theory consists in the idea that some strongly coupled gauge theories may have a dual description in terms of a higher dimensional weakly coupled gravitational theory — the so-called AdS/CFT correspondence or gauge/gravity correspondence. The attempts to apply this idea to the real QCD are often referred to as "holographic QCD" or "AdS/QCD approach". One of directions in this field is to start from the real QCD and guess a tentative dual higher dimensional weakly coupled field model following the principles of gauge/gravity correspondence. The ensuing phenomenology can be then developed and compared with experimental data and with various theoretical results. Such a bottom-up holographic approach turned out to be unexpectedly successful in many cases. In the given short review, the technical aspects of the bottom-up holographic approach to QCD are explained placing the main emphasis on the soft wall model.

  17. Bottom-trawling along submarine canyons impacts deep sedimentary regimes

    Science.gov (United States)

    Paradis, Sarah; Puig, Pere; Masqué, Pere; Juan-Díaz, Xènia; Martín, Jacobo; Palanques, Albert

    2017-01-01

    Many studies highlight that fish trawling activities cause seafloor erosion, but the assessment of the remobilization of surface sediments and its relocation is still not well documented. These impacts were examined along the flanks and axes of three headless submarine canyons incised on the Barcelona continental margin, where trawling fleets have been operating for decades. Trawled grounds along canyon flanks presented eroded and highly reworked surface sediments resulting from the passage of heavy trawling gear. Sedimentation rates on the upper canyon axes tripled and quadrupled its natural (i.e. pre-industrialization) values after a substantial increase in total horsepower of the operating trawling fleets between 1960 s and 1970 s. These impacts affected the upper canyon reaches next to fishing grounds, where sediment resuspended by trawling can be transported towards the canyon axes. This study highlights that bottom trawling has the capacity to alter natural sedimentary environments by promoting sediment-starved canyon flanks, and by enhancing sedimentation rates along the contiguous axes, independently of canyons’ morphology. Considering the global mechanisation and offshore expansion of bottom trawling fisheries since the mid-20th century, these sedimentary alterations may occur in many trawled canyons worldwide, with further ecological impacts on the trophic status of these non-resilient benthic communities. PMID:28233856

  18. High firing rate of neonatal hippocampal interneurons is caused by attenuation of afterhyperpolarizing potassium currents by tonically active kainate receptors.

    Science.gov (United States)

    Segerstråle, Mikael; Juuri, Juuso; Lanore, Frédéric; Piepponen, Petteri; Lauri, Sari E; Mulle, Christophe; Taira, Tomi

    2010-05-12

    In the neonatal hippocampus, the activity of interneurons shapes early network bursts that are important for the establishment of neuronal connectivity. However, mechanisms controlling the firing of immature interneurons remain elusive. We now show that the spontaneous firing rate of CA3 stratum lucidum interneurons markedly decreases during early postnatal development because of changes in the properties of GluK1 (formerly known as GluR5) subunit-containing kainate receptors (KARs). In the neonate, activation of KARs by ambient glutamate exerts a tonic inhibition of the medium-duration afterhyperpolarization (mAHP) by a G-protein-dependent mechanism, permitting a high interneuronal firing rate. During development, the amplitude of the apamine-sensitive K+ currents responsible for the mAHP increases dramatically because of decoupling between KAR activation and mAHP modulation, leading to decreased interneuronal firing. The developmental shift in the KAR function and its consequences on interneuronal activity are likely to have a fundamental role in the maturation of the synchronous neuronal oscillations typical for adult hippocampal circuitry.

  19. A study of sediment motions and bottom layer dynamics over the Middle Atlantic Bight shelf and upper slope. Final technical report, 1 June 1992--31 May 1995

    Energy Technology Data Exchange (ETDEWEB)

    Pietrafesa, L.J.

    1995-12-31

    A study of sediment dynamics over the Middle Atlantic Bight (MAB) in the vicinity of the Cape Hatteras Confluence (CHC), including the mouths of estuaries, the shelf and the slope, was carried out by investigators at North Carolina State University as part of the Department of Energy Ocean Margins Program. Studied were processes effecting sediment motion. In particular, the processes which determine rates of vertical transport of dissolved carbon dioxide and organic matter and particulates to and from the bottom by turbulent mixing resuspension and particulate sinking and vertical motions induced by BBL convergences; especially during periods of storm activity when both surface waves and currents are maxima.

  20. SUMOylation of the Hyperpolarization-Activated Cyclic Nucleotide-Gated Channel 2 Increases Surface Expression and the Maximal Conductance of the Hyperpolarization-Activated Current

    Science.gov (United States)

    Parker, Anna R.; Welch, Meghyn A.; Forster, Lori A.; Tasneem, Sarah M.; Dubhashi, Janhavi A.; Baro, Deborah J.

    2017-01-01

    Small Ubiquitin-like Modifier (SUMO) is a ∼10 kDa peptide that can be post-translationally added to a lysine (K) on a target protein to facilitate protein–protein interactions. Recent studies have found that SUMOylation can be regulated in an activity-dependent manner and that ion channel SUMOylation can alter the biophysical properties and surface expression of the channel. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channel surface expression can be regulated in an activity-dependent manner through unknown processes. We hypothesized that SUMOylation might influence the surface expression of HCN2 channels. In this manuscript, we show that HCN2 channels are SUMOylated in the mouse brain. Baseline levels of SUMOylation were also observed for a GFP-tagged HCN2 channel stably expressed in Human embryonic kidney (Hek) cells. Elevating GFP-HCN2 channel SUMOylation above baseline in Hek cells led to an increase in surface expression that augmented the hyperpolarization-activated current (Ih) mediated by these channels. Increased SUMOylation did not alter Ih voltage-dependence or kinetics of activation. There are five predicted intracellular SUMOylation sites on HCN2. Site-directed mutagenesis indicated that more than one K on the GFP-HCN2 channel was SUMOylated. Enhancing SUMOylation at one of the five predicted sites, K669, led to the increase in surface expression and Ih Gmax. The role of SUMOylation at additional sites is currently unknown. The SUMOylation site at K669 is also conserved in HCN1 channels. Aberrant SUMOylation has been linked to neurological diseases that also display alterations in HCN1 and HCN2 channel expression, such as seizures and Parkinson’s disease. This work is the first report that HCN channels can be SUMOylated and that this can regulate surface expression and Ih. PMID:28127275

  1. From geospatial observations of ocean currents to causal predictors of spatio-economic activity using computer vision and machine learning

    Science.gov (United States)

    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

  2. Effects of Atractylodes Macrocephala on the Cytomembrane Ca2+-activated K+ Currents in Cells of Human Pregnant Myometrial Smooth Muscles

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    Kjeldsen, Lisbeth Stigaard; Ghisari, Mandana; Bonefeld-Jørgensen, Eva Cecilie

    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 [(3)H](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. MAPPING OF EXISTING MARICULTURE ACTIVITIES IN SOUTH-EAST SULAWESI “POTENTIAL, CURRENT AND FUTURE STATUS”

    Directory of Open Access Journals (Sweden)

    Hatim Albasri

    2010-12-01

    Full Text Available The present study identifies existing mariculture activities and its constraints in SE Sulawesi, along with its geo-physical attributes in the Province.This allows for a better understanding the potential, current and future status of mariculture development in the area and making sure its sustainability. The study was conducted to map the existing mariculture activities in SE Sulawesi. Data collection was performed in June 2009. Spatial and attribute data of the existing mariculture were acquired by interviewing fish farmer using open-ended questionnaire and analyzed using ArcGIS 9.x. Key water quality parameters consisted of temperature, dissolved oxygen, pH, salinity, depth, clarity, and turbidity and analyzed using STORET Indeks. Three big clusters of existing mariculture activities are located in Kendari, Muna and Buton areas, collectively serving as both a source of mariculture products and a market destination or transit location. All surveyed locations of existing mariculture activities in SE Sulawesi show relatively optimal water quality conditions. Site capacity and suitability analysis of existing or potential areas of mariculture activities and development have largely not been considered by stakeholders involved in managing coastal areas, resulting in crowded and unmanaged development with multiple overlapping economic activities in some areas. Piloting of integrated ‘value-adding’ mariculture industries (e.g. raw material, processed products and ‘ready to eat’ industries might help ease some if not all of the existing economic problems of the mariculture sector.

  5. Pituitary adenylate cyclase-activating polypeptide (PACAP) inhibits the slow afterhyperpolarizing current sIAHP in CA1 pyramidal neurons by activating multiple signaling pathways.

    Science.gov (United States)

    Taylor, Ruth D T; Madsen, Marita Grønning; Krause, Michael; Sampedro-Castañeda, Marisol; Stocker, Martin; Pedarzani, Paola

    2014-01-01

    The slow afterhyperpolarizing current (sIAHP ) is a calcium-dependent potassium current that underlies the late phase of spike frequency adaptation in hippocampal and neocortical neurons. sIAHP is a well-known target of modulation by several neurotransmitters acting via the cyclic AMP (cAMP) and protein kinase A (PKA)-dependent pathway. The neuropeptide pituitary adenylate cyclase activating peptide (PACAP) and its receptors are present in the hippocampal formation. In this study we have investigated the effect of PACAP on the sIAHP and the signal transduction pathway used to modulate intrinsic excitability of hippocampal pyramidal neurons. We show that PACAP inhibits the sIAHP , resulting in a decrease of spike frequency adaptation, in rat CA1 pyramidal cells. The suppression of sIAHP by PACAP is mediated by PAC1 and VPAC1 receptors. Inhibition of PKA reduced the effect of PACAP on sIAHP, suggesting that PACAP exerts part of its inhibitory effect on sIAHP by increasing cAMP and activating PKA. The suppression of sIAHP by PACAP was also strongly hindered by the inhibition of p38 MAP kinase (p38 MAPK). Concomitant inhibition of PKA and p38 MAPK indicates that these two kinases act in a sequential manner in the same pathway leading to the suppression of sIAHP. Conversely, protein kinase C is not part of the signal transduction pathway used by PACAP to inhibit sIAHP in CA1 neurons. Our results show that PACAP enhances the excitability of CA1 pyramidal neurons by inhibiting the sIAHP through the activation of multiple signaling pathways, most prominently cAMP/PKA and p38 MAPK. Our findings disclose a novel modulatory action of p38 MAPK on intrinsic excitability and the sIAHP, underscoring the role of this current as a neuromodulatory hub regulated by multiple protein kinases in cortical neurons.

  6. How To Design A Triple Bottom Line Organization: A Start-Up Case Study

    Directory of Open Access Journals (Sweden)

    Bernhard Schroeder

    2014-05-01

    Full Text Available In today’s business environment, where success for a start-up company is measured by early revenue and profit, it can be quite challenging to design a triple bottom line organization (people/planet/profit from the very beginning. We present a case study of a U.S.-based start-up firm and discuss its early challenges, developmental processes, and current success as a triple bottom line firm. The company’s founder and CEO, with no initial product, distribution, or revenue strategy, sought to develop a company that could provide the marketplace with a valuable product while also staying true to a corporate vision of positively affecting less fortunate people. Our analysis of the case suggests that the founder’s vision, passion, transparent communication, and leveraging of partners’ resources were key elements in building the firm. We draw implications of our case study for the designers of future triple bottom line organizations.

  7. A 'bottom-up' approach to aetiological research in autism spectrum disorders

    Directory of Open Access Journals (Sweden)

    Lisa Marie Unwin

    2013-09-01

    Full Text Available Autism Spectrum Disorders (ASD are currently diagnosed in the presence of impairments in social interaction and communication, and a restricted range of activities and interests. However, there is considerable variability in the behaviours of different individuals with an ASD diagnosis. The heterogeneity spans the entire range of IQ and language abilities, as well as other behavioural, communicative and social functions. While any psychiatric condition is likely to incorporate a degree of heterogeneity, the variability in the nature and severity of behaviours observed in ASD is thought to exceed that of other disorders. The current paper aims to provide a model for future research into ASD subgroups. In doing so, we examined whether two proposed risk factors – low birth weight (LBW, and in-utero exposure to selective serotonin reuptake inhibitors (SSRIs – are associated with greater behavioural homogeneity. Using data from the Western Australian Autism Biological Registry, this study found that LBW and maternal SSRI use during pregnancy were associated with greater sleep disturbances and a greater number of gastrointestinal complaints in children with ASD, respectively. The findings from this ‘proof of principle’ paper provide support for this 'bottom-up' approach as a feasible method for creating homogenous groups.

  8. Aluminium recovery from waste incineration bottom ash, and its oxidation level.

    Science.gov (United States)

    Biganzoli, Laura; Grosso, Mario

    2013-09-01

    The recovery of aluminium (Al) scraps from waste incineration bottom ash is becoming a common practice in waste management. However, during the incineration process, Al in the waste undergoes oxidation processes that reduce its recycling potential. This article investigates the behaviour of Al scraps in the furnace of two selected grate-fired waste-to-energy plants and the amount recoverable from the bottom ash. About 21-23% of the Al fed to the furnace with the residual waste was recovered and potentially recycled from the bottom ash. Out of this amount, 76-87% was found in the bottom ash fraction above 5 mm and thus can be recovered with standard eddy current separation technology. These values depend on the characteristics and the mechanical strength of the Al items in the residual waste. Considering Al packaging materials, about 81% of the Al in cans can be recovered from the bottom ash as an ingot, but this amount decreases to 51% for trays, 27% for a mix of aluminium and poly-laminated foils and 47% for paper-laminated foils. This shows that the recovery of Al from the incineration residues increases proportionally to the thickness of the packaging.

  9. Functional coupling between sodium-activated potassium channels and voltage-dependent persistent sodium currents in cricket Kenyon cells.

    Science.gov (United States)

    Takahashi, Izumi; Yoshino, Masami

    2015-10-01

    In this study, we examined the functional coupling between Na(+)-activated potassium (KNa) channels and Na(+) influx through voltage-dependent Na(+) channels in Kenyon cells isolated from the mushroom body of the cricket Gryllus bimaculatus. Single-channel activity of KNa channels was recorded with the cell-attached patch configuration. The open probability (Po) of KNa channels increased with increasing Na(+) concentration in a bath solution, whereas it decreased by the substitution of Na(+) with an equimolar concentration of Li(+). The Po of KNa channels was also found to be reduced by bath application of a high concentration of TTX (1 μM) and riluzole (100 μM), which inhibits both fast (INaf) and persistent (INaP) Na(+) currents, whereas it was unaffected by a low concentration of TTX (10 nM), which selectively blocks INaf. Bath application of Cd(2+) at a low concentration (50 μM), as an inhibitor of INaP, also decreased the Po of KNa channels. Conversely, bath application of the inorganic Ca(2+)-channel blockers Co(2+) and Ni(2+) at high concentrations (500 μM) had little effect on the Po of KNa channels, although Cd(2+) (500 μM) reduced the Po of KNa channels. Perforated whole cell clamp analysis further indicated the presence of sustained outward currents for which amplitude was dependent on the amount of Na(+) influx. Taken together, these results indicate that KNa channels could be activated by Na(+) influx passing through voltage-dependent persistent Na(+) channels. The functional significance of this coupling mechanism was discussed in relation to the membrane excitability of Kenyon cells and its possible role in the formation of long-term memory.

  10. Accelerated activation of SOCE current in myotubes from two mouse models of anesthetic- and heat-induced sudden death.

    Directory of Open Access Journals (Sweden)

    Viktor Yarotskyy

    Full Text Available Store-operated calcium entry (SOCE channels play an important role in Ca(2+ signaling. Recently, excessive SOCE was proposed to play a central role in the pathogenesis of malignant hyperthermia (MH, a pharmacogenic disorder of skeletal muscle. We tested this hypothesis by characterizing SOCE current (ISkCRAC magnitude, voltage dependence, and rate of activation in myotubes derived from two mouse models of anesthetic- and heat-induced sudden death: 1 type 1 ryanodine receptor (RyR1 knock-in mice (Y524S/+ and 2 calsequestrin 1 and 2 double knock-out (dCasq-null mice. ISkCRAC voltage dependence and magnitude at -80 mV were not significantly different in myotubes derived from wild type (WT, Y524S/+ and dCasq-null mice. However, the rate of ISkCRAC activation upon repetitive depolarization was significantly faster at room temperature in myotubes from Y524S/+ and dCasq-null mice. In addition, the maximum rate of ISkCRAC activation in dCasq-null myotubes was also faster than WT at more physiological temperatures (35-37°C. Azumolene (50 µM, a more water-soluble analog of dantrolene that is used to reverse MH crises, failed to alter ISkCRAC density or rate of activation. Together, these results indicate that while an increased rate of ISkCRAC activation is a common characteristic of myotubes derived from Y524S/+ and dCasq-null mice and that the protective effects of azumolene are not due to a direct inhibition of SOCE channels.

  11. Upgrade of the ESA DRAMA OSCAR Tool: Analysis of Disposal Strategies Considering Current Standards for Future Solar and Geomagnetic Activity

    Science.gov (United States)

    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

  12. The Bottom Class Children Happy Morning Sports Activities Carried out Effectively%小班幼儿快乐晨间体育活动的有效开展

    Institute of Scientific and Technical Information of China (English)

    程国琴

    2014-01-01

    “Kindergarten education guidelines”put forward the infant health perspectives of “paying equal attention to body and mind”, and put the children on the first of five fields. Morning effective to organize the implementation of outdoor sports,which is an effective way to promote children’s physical and mental development, one hour in the morning is worth two in the evening, every reasonable scientific effectively organized outdoor morning sports activities can make children have a strong and healthy physique, more sunshine, cheerful, lively personality.%《幼儿园教育指导纲要》提出“身心并重”的幼儿健康观,并将幼儿健康放在了五大领域的首位。晨间户外体育活动的有效组织实施,是促进幼儿身心发展的有效途径,一日之计在于晨,每天合理科学有效地组织晨间户外体育活动,可以使幼儿拥有健康强壮的体质,更阳光、开朗、活泼的个性。

  13. Peach Bottom test element program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Saurwein, J.J.; Holzgraf, J.F.; MIller, C.M.; Myers, B.F.; Wallroth, C.F.

    1982-11-01

    Thirty-three test elements were irradiated in the Peach Bottom high-temperature gas-cooled reactor (HTGR) as part of the testing program for advanced HTGRs. Extensive postirradiation examinations and evaluations of 21 of these irradiation experiments were performed. The test element irradiations were simulated using HTGR design codes and data. Calculated fuel burnups, power profiles, fast neutron fluences, and temperatures were verified via destructive burnup measurements, gamma scanning, and in-pile thermocouple readings corrected for decalibration effects. Analytical techniques were developed to improve the quality of temperature predictions through feedback of nuclear measurements into thermal calculations. Dimensional measurements, pressure burst tests, diametral compression tests, ring-cutting tests, strip-cutting tests, and four-point bend tests were performed to measure residual stress, strain, and strength distributions in H-327 graphite structures irradiated in the test elements.

  14. Conductivity Probe after Trench-Bottom Placement

    Science.gov (United States)

    2008-01-01

    Needles of the thermal and conductivity probe on NASA's Phoenix Mars Lander were positioned into the bottom of a trench called 'Upper Cupboard' during Sol 86 (Aug. 21, 2008), or 86th Martian day after landing. This image of the conductivity probe after it was raised back out of the trench was taken by Phoenix's Robotic Arm Camera. The conductivity probe is at the wrist of the robotic arm's scoop. The probe measures how fast heat and electricity move from one needle to an adjacent one through the soil or air between the needles. Conductivity readings can be indicators about water vapor, water ice and liquid water. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  15. Barotropic flow over bottom topography— experiments and nonlinear theory

    Science.gov (United States)

    Pfeffer, Richard L.; Kung, Robin; Ding, Wen; Li, Guo-Qing

    1993-10-01

    Barotropic flow over finite amplitude two-wave bottom topography is investigated both experimentally and theoretically over a broad parameter range. In the experiments, the fluid is contained in a vertically oriented, rotating circular cylindrical annulus. It is forced into motion relative to the annulus by a differentially rotating, rigid, radially sloping lid in contact with the top surface of the fluid. The radial depth variation associated with the slope of the lid, and an equal and opposite slope of the bottom boundary, simulates the effect of the variation of the Coriolis parameter with latitude (β) in planetary atmospheres and in the ocean. The dimensionless parameters which control the fluid behavior are the Rossby number (ɛ), the Ekman number (E), the β parameter, the aspect ratio (δ), the ratio of the mean radius to the gap width (α) and the ratio of the topographic height to the mean fluid depth (η). The Rossby and Ekman numbers are varied over an order of magnitude by conducting experiments at different rotation rates of the annulus. Velocity measurements using photographs of tracer particles suspended in the fluid reveal the existence of a stationary, topographically forced wave superimposed on an azimuthal mean current. With successively larger rotation rates (i.e. lower ɛ and E) the wave amplitude increases and then levels off, the phase displacement of the wave upstream of the topography increases and the azimuthal mean velocity decreases and then levels off. Linear quasigeostophic theory accounts qualitatively, but not quantitatively, for the phase displacement, predicts the wave amplitude poorly and provides no basis for predicting the zonal mean velocity. Accordingly, we have solved the nonlinear, steady-state, quasigeostrophic barotrophic vorticity equation with both Ekman layer and internal dissipation using a spectral colocation method with Fourier representation in the azimuthal direction and Chebyshev polynomial representation in the

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

    DEFF Research Database (Denmark)

    Dyrda, Agnieszka; Cytlak, Urszula; Ciuraszkiewicz, Anna

    2010-01-01

    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 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...

  17. Measurement of the Total Active 8B Solar Neutrino Flux at the Sudbury Neutrino Observatory with Enhanced Neutral Current Sensitivity

    CERN Document Server

    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.

  18. Measurement of the total active 8B solar neutrino flux at the Sudbury Neutrino Observatory with enhanced neutral current sensitivity.

    Science.gov (United States)

    Ahmed, S N; Anthony, A E; 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; Mifflin, 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; 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; Tesić, G; Thomson, M; Thorman, M; Van Berg, R; Van de Water, R G; Virtue, C J; Wall, B L; Waller, D; Waltham, C E; Tseung, H Wan Chan; Wark, D L; West, N; Wilhelmy, J B; Wilkerson, J F; Wilson, J R; Wouters, J M; Yeh, M; Zuber, K

    2004-05-07

    The Sudbury Neutrino Observatory 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 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) x 10(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 Deltam(2)=7.1(+1.2)(-0.6) x 10(-5) eV(2) and theta=32.5(+2.4)(-2.3) degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

  19. Characterization of the past and current duplication activities in the human 22q11.2 region

    Directory of Open Access Journals (Sweden)

    Morrow Bernice

    2011-01-01

    Full Text Available Abstract Background Segmental duplications (SDs on 22q11.2 (LCR22, serve as substrates for meiotic non-allelic homologous recombination (NAHR events resulting in several clinically significant genomic disorders. Results To understand the duplication activity leading to the complicated SD structure of this region, we have applied the A-Bruijn graph algorithm to decompose the 22q11.2 SDs to 523 fundamental duplication sequences, termed subunits. Cross-species syntenic analysis of primate genomes demonstrates that many of these LCR22 subunits emerged very recently, especially those implicated in human genomic disorders. Some subunits have expanded more actively than others, and young Alu SINEs, are associated much more frequently with duplicated sequences that have undergone active expansion, confirming their role in mediating recombination events. Many copy number variations (CNVs exist on 22q11.2, some flanked by SDs. Interestingly, two chromosome breakpoints for 13 CNVs (mean length 65 kb are located in paralogous subunits, providing direct evidence that SD subunits could contribute to CNV formation. Sequence analysis of PACs or BACs identified extra CNVs, specifically, 10 insertions and 18 deletions within 22q11.2; four were more than 10 kb in size and most contained young AluYs at their breakpoints. Conclusions Our study indicates that AluYs are implicated in the past and current duplication events, and moreover suggests that DNA rearrangements in 22q11.2 genomic disorders perhaps do not occur randomly but involve both actively expanded duplication subunits and Alu elements.

  20. The Importance of Being with Sir Ernest Shackleton at the Bottom of the World.

    Science.gov (United States)

    Katz, Claudia Anne; Boran, Karen; Braun, Timothy J.; Massie, Mary J.; Kuby, Sue Ann

    2003-01-01

    Describes an integrated thematic unit designed for readers in grades 8 to 10. Contains a four- to six-week plan that encompasses reading strategies, inquiry projects, and assessment tools and includes an activity map (based on Jennifer Armstrong's "Shipwreck at the Bottom of the World: The Extraordinary True Story of Shackleton and the…

  1. Impacts of offshore wind energy turbines on marine bottom fauna

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, A. [Alfred Wegener Institute for Polar- and Marine Research, Bremerhaven (Germany)

    2007-07-01

    The foundations of offshore wind energy farms will cause alterations to the natural marine habitat of the North and Baltic Seas. The seabed in the proposed areas for offshore windfarms is mainly characterised by soft sediments ranging from medium sands to silt. The underwater structures themselves not only provide empty space for the settlement of hardbottom epifauna, which do not naturally occur in these areas, but they also alter the surrounding natural habitat. In the absence of actual wind farms in German waters, the research platform FINO 1 was used in the project BeoFINO to study biologic processes around the underwater structure leading to alterations of the natural bottom fauna. Shortly after installation, the surface was colonised by an epifauna consisting of few species, but reaching a high biomass. Mytilus edulis dominated in the upper depth zone, while lower reaches were dominated by the Amphipod Jassa spp. and Anthozoans (mainly Metridium senile). Changed current conditions around the structure lead to erosion and altered sediment composition with thick layers of empty shells on the surface. Natural soft bottom fauna is strongly reduced in the vicinity of the platform, while predators and scavengers profit from the additional food source provided by material falling from the platform. The export of lighter material like faeces is predicted to spread over larger areas. Dense aggregations of pelagic fish were observed around the platform, while some demersal species also live in niches of the structure. All results are combined in mathematical models in order to compare different locations and to calculate scenarios for wind farm effects in various habitats. (orig.)

  2. Self-assembled nanostructured resistive switching memory devices fabricated by templated bottom-up growth.

    Science.gov (United States)

    Song, Ji-Min; Lee, Jang-Sik

    2016-01-07

    Metal-oxide-based resistive switching memory device has been studied intensively due to its potential to satisfy the requirements of next-generation memory devices. Active research has been done on the materials and device structures of resistive switching memory devices that meet the requirements of high density, fast switching speed, and reliable data storage. In this study, resistive switching memory devices were fabricated with nano-template-assisted bottom up growth. The electrochemical deposition was adopted to achieve the bottom-up growth of nickel nanodot electrodes. Nickel oxide layer was formed by oxygen plasma treatment of nickel nanodots at low temperature. The structures of fabricated nanoscale memory devices were analyzed with scanning electron microscope and atomic force microscope (AFM). The electrical characteristics of the devices were directly measured using conductive AFM. This work demonstrates the fabrication of resistive switching memory devices using self-assembled nanoscale masks and nanomateirals growth from bottom-up electrochemical deposition.

  3. Phase modulated solitary waves controlled by bottom boundary condition

    CERN Document Server

    Mukherjee, Abhik

    2014-01-01

    A forced KdV equation is derived to describe weakly nonlinear, shallow water surface wave propagation over non trivial bottom boundary condition. We show that different functional forms of bottom boundary conditions self-consistently produce different forced kdV equations as the evolution equations for the free surface. Solitary wave solutions have been analytically obtained where phase gets modulated controlled by bottom boundary condition whereas amplitude remains constant.

  4. Elastic Bottom Propagation Mechanisms Investigated by Parabolic Equation Methods

    Science.gov (United States)

    2014-09-30

    environments in the form of scattering at an elastic interface, oceanic T - waves , and Scholte waves . OBJECTIVES To implement explosive and earthquake...of the the deep ocean where there is no significant sloping bottom. It is believed that ocean bottom roughness scatters the elastic waves up into...Scholte interface waves are excited by seismic sources and have been observed by seismometers at the ocean bottom.[12, 13] Energy from interface waves has

  5. Transient Temperature Analysis for Industrial AC Arc Furnace Bottom

    Institute of Scientific and Technical Information of China (English)

    (U)nal (C)amdal1; Murat Tun(c)

    2004-01-01

    Heat losses from the furnaces depend on the design and size. The surface heat loss from the bottom of an industrial AC electric arc furnace (EAF) possesses an important fraction of overall losses. So in this study the transient temperature variation at the bottom of the EAF was investigated. The transient temperature analysis was carried out using MATLAB computer program. T=T(r, t) for different bottom lining layers was depicted.

  6. Excitation-Contraction Coupling between Human Atrial Myocytes with Fibroblasts and Stretch Activated Channel Current: A Simulation Study

    Directory of Open Access Journals (Sweden)

    Heqing Zhan

    2013-01-01

    Full Text Available Myocytes have been regarded as the main objectives in most cardiac modeling studies and attracted a lot of attention. Connective tissue cells, such as fibroblasts (Fbs, also play crucial role in cardiac function. This study proposed an integrated myocyte-Isac-Fb electromechanical model to investigate the effect of Fbs and stretch activated ion channel current (Isac on cardiac electrical excitation conduction and mechanical contraction. At the cellular level, an active Fb model was coupled with a human atrial myocyte electrophysiological model (including Isac and a mechanical model. At the tissue level, electrical excitation conduction was coupled with an elastic mechanical model, in which finite difference method (FDM was used to solve the electrical excitation equations, while finite element method (FEM was used for the mechanics equations. The simulation results showed that Fbs and Isac coupling caused diverse effects on action potential morphology during repolarization, depolarized the resting membrane potential of the human atrial myocyte, slowed down wave propagation, and decreased strains in fibrotic tissue. This preliminary simulation study indicates that Fbs and Isac have important implications for modulating cardiac electromechanical behavior and should be considered in future cardiac modeling studies.

  7. An impression on current developments in the technology, chemistry, and biological activities of ginger (Zingiber officinale Roscoe).

    Science.gov (United States)

    Kubra, I Rahath; Rao, L Jagan Mohan

    2012-01-01

    Ginger rhizome (Zingiber officinale Roscoe) is widely cultivated as a spice for its aromatic and pungent components. The essential oil and oleoresins from ginger are valuable products responsible for the characteristic flavor and pungency. Both are used in several food products such as soft beverages and also in many types of pharmaceutical formulations. More than 100 compounds have been reported from ginger, some of which are isolated and characterized, others are tentatively identified by GC-MS and / or LC-MS. [6]-Gingerol, the major gingerol in ginger rhizomes, has been found to possess many interesting pharmacological and physiological activities, such as anti-inflammatory, analgesic, and cardiotonic effects. Ginger is considered as "generally recognized as safe" (GRAS) by Food and Drug Administration (FDA), USA. Due to all these properties, ginger has gained considerable attention in developed countries in recent years, especially for its use in the treatment of inflammatory conditions. The present review is a persuasive presentation of the current information on processing, chemistry, biological activities, and medicinal uses of ginger. Further studies are required for the validation of the beneficial uses. Formulation for novel products and new usages may emerge in the years to come, based on the revealed results of various studies.

  8. Current selection for lower migratory activity will drive the evolution of residency in a migratory bird population.

    Science.gov (United States)

    Pulido, Francisco; Berthold, Peter

    2010-04-20

    Global warming is impacting biodiversity by altering the distribution, abundance, and phenology of a wide range of animal and plant species. One of the best documented responses to recent climate change is alterations in the migratory behavior of birds, but the mechanisms underlying these phenotypic adjustments are largely unknown. This knowledge is still crucial to predict whether populations of migratory birds will adapt to a rapid increase in temperature. We monitored migratory behavior in a population of blackcaps (Sylvia atricapilla) to test for evolutionary responses to recent climate change. Using a common garden experiment in time and captive breeding we demonstrated a genetic reduction in migratory activity and evolutionary change in phenotypic plasticity of migration onset. An artificial selection experiment further revealed that residency will rapidly evolve in completely migratory bird populations if selection for shorter migration distance persists. Our findings suggest that current alterations of the environment are favoring birds wintering closer to the breeding grounds and that populations of migratory birds have strongly responded to these changes in selection. The reduction of migratory activity is probably an important evolutionary process in the adaptation of migratory birds to climate change, because it reduces migration costs and facilitates the rapid adjustment to the shifts in the timing of food availability during reproduction.

  9. Sintering process and critical current density of low activation Mg11B2 superconductors from low temperature to high temperature

    Science.gov (United States)

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, Md; Somer, M.

    2016-08-01

    As the "low activation" superconductor, Mg11B2 has a potential application in superconducting coils for fusion reactor. In present work, the sintering process and critical current density of low activation Mg11B2 superconductors were systemically studied from low temperature to high temperature. It was found that the Jc and Hirr values of Mg11B2 bulks in present work are both obviously higher than that of those samples prepared in previous studies. Furthermore, the low-temperature sintered samples exhibit better Jc performance at high fields than the high-temperature sintered samples, due to strong grain boundaries pinning. On the other hand, the high-temperature sintered samples have higher Jc at low fields compared to low-temperature sintered samples, mainly owing to their better crystallinity and grain connectivity. The highest Jc value (2.20 ×105 A cm-2 at 20 K, self-field) is obtained in the Mg11B2 sample sintered at 850 °C for 45 min.

  10. Pituitary adenylate cyclase-activating polypeptide (PACAP) inhibits the slow afterhyperpolarizing current sIAHP in CA1 pyramidal neurons by activating multiple signaling pathways

    Science.gov (United States)

    Taylor, Ruth DT; Madsen, Marita Grønning; Krause, Michael; Sampedro-Castañeda, Marisol; Stocker, Martin; Pedarzani, Paola

    2014-01-01

    The slow afterhyperpolarizing current (sIAHP) is a calcium-dependent potassium current that underlies the late phase of spike frequency adaptation in hippocampal and neocortical neurons. sIAHP is a well-known target of modulation by several neurotransmitters acting via the cyclic AMP (cAMP) and protein kinase A (PKA)-dependent pathway. The neuropeptide pituitary adenylate cyclase activating peptide (PACAP) and its receptors are present in the hippocampal formation. In this study we have investigated the effect of PACAP on the sIAHP and the signal transduction pathway used to modulate intrinsic excitability of hippocampal pyramidal neurons. We show that PACAP inhibits the sIAHP, resulting in a decrease of spike frequency adaptation, in rat CA1 pyramidal cells. The suppression of sIAHP by PACAP is mediated by PAC1 and VPAC1 receptors. Inhibition of PKA reduced the effect of PACAP on sIAHP, suggesting that PACAP exerts part of its inhibitory effect on sIAHP by increasing cAMP and activating PKA. The suppression of sIAHP by PACAP was also strongly hindered by the inhibition of p38 MAP kinase (p38 MAPK). Concomitant inhibition of PKA and p38 MAPK indicates that these two kinases act in a sequential manner in the same pathway leading to the suppression of sIAHP. Conversely, protein kinase C is not part of the signal transduction pathway used by PACAP to inhibit sIAHP in CA1 neurons. Our results show that PACAP enhances the excitability of CA1 pyramidal neurons by inhibiting the sIAHP through the activation of multiple signaling pathways, most prominently cAMP/PKA and p38 MAPK. Our findings disclose a novel modulatory action of p38 MAPK on intrinsic excitability and the sIAHP, underscoring the role of this current as a neuromodulatory hub regulated by multiple protein kinases in cortical neurons. © 2013 The Authors. Hippocampus Published by Wiley Periodicals, Inc. PMID:23996525

  11. Method of coupled mode for long-range bottom reverberation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The theory of coupled mode is used for modeling the long-range bottom reverberation in shallow water caused by bottom roughness. The distant bottom reverberation level and spatial coherence of impulsive source are both derived. The results agree with those from the classical reverberation model, and are compared with the experimental data. The influence of source bandwidth and the distance between sources and receivers on the intensity of bottom reverberation are particularly discussed. The method is shown to be available for both the monoand the bi-static cases.

  12. Tonic 5nM DA stabilizes neuronal output by enabling bidirectional activity-dependent regulation of the hyperpolarization activated current via PKA and calcineurin.

    Directory of Open Access Journals (Sweden)

    Wulf-Dieter C Krenz

    Full Text Available Volume transmission results in phasic and tonic modulatory signals. The actions of tonic dopamine (DA at type 1 DA receptors (D1Rs are largely undefined. Here we show that tonic 5nM DA acts at D1Rs to stabilize neuronal output over minutes by enabling activity-dependent regulation of the hyperpolarization activated current (I h. In the presence but not absence of 5nM DA, I h maximal conductance (G max was adjusted according to changes in slow wave activity in order to maintain spike timing. Our study on the lateral pyloric neuron (LP, which undergoes rhythmic oscillations in membrane potential with depolarized plateaus, demonstrated that incremental, bi-directional changes in plateau duration produced corresponding alterations in LP I hG max when preparations were superfused with saline containing 5nM DA. However, when preparations were superfused with saline alone there was no linear correlation between LP I hGmax and duty cycle. Thus, tonic nM DA modulated the capacity for activity to modulate LP I h G max; this exemplifies metamodulation (modulation of modulation. Pretreatment with the Ca2+-chelator, BAPTA, or the specific PKA inhibitor, PKI, prevented all changes in LP I h in 5nM DA. Calcineurin inhibitors blocked activity-dependent changes enabled by DA and revealed a PKA-mediated, activity-independent enhancement of LP I hG max. These data suggested that tonic 5nM DA produced two simultaneous, PKA-dependent effects: a direct increase in LP I h G max and a priming event that permitted calcineurin regulation of LP I h. The latter produced graded reductions in LP I hG max with increasing duty cycles. We also demonstrated that this metamodulation preserved the timing of LP's first spike when network output was perturbed with bath-applied 4AP. In sum, 5nM DA permits slow wave activity to provide feedback that maintains spike timing, suggesting that one function of low-level, tonic modulation is to stabilize specific features of a dynamic output.

  13. Tonic 5nM DA stabilizes neuronal output by enabling bidirectional activity-dependent regulation of the hyperpolarization activated current via PKA and calcineurin.

    Science.gov (United States)

    Krenz, Wulf-Dieter C; Rodgers, Edmund W; Baro, Deborah J

    2015-01-01

    Volume transmission results in phasic and tonic modulatory signals. The actions of tonic dopamine (DA) at type 1 DA receptors (D1Rs) are largely undefined. Here we show that tonic 5nM DA acts at D1Rs to stabilize neuronal output over minutes by enabling activity-dependent regulation of the hyperpolarization activated current (I h). In the presence but not absence of 5nM DA, I h maximal conductance (G max) was adjusted according to changes in slow wave activity in order to maintain spike timing. Our study on the lateral pyloric neuron (LP), which undergoes rhythmic oscillations in membrane potential with depolarized plateaus, demonstrated that incremental, bi-directional changes in plateau duration produced corresponding alterations in LP I hG max when preparations were superfused with saline containing 5nM DA. However, when preparations were superfused with saline alone there was no linear correlation between LP I hGmax and duty cycle. Thus, tonic nM DA modulated the capacity for activity to modulate LP I h G max; this exemplifies metamodulation (modulation of modulation). Pretreatment with the Ca2+-chelator, BAPTA, or the specific PKA inhibitor, PKI, prevented all changes in LP I h in 5nM DA. Calcineurin inhibitors blocked activity-dependent changes enabled by DA and revealed a PKA-mediated, activity-independent enhancement of LP I hG max. These data suggested that tonic 5nM DA produced two simultaneous, PKA-dependent effects: a direct increase in LP I h G max and a priming event that permitted calcineurin regulation of LP I h. The latter produced graded reductions in LP I hG max with increasing duty cycles. We also demonstrated that this metamodulation preserved the timing of LP's first spike when network output was perturbed with bath-applied 4AP. In sum, 5nM DA permits slow wave activity to provide feedback that maintains spike timing, suggesting that one function of low-level, tonic modulation is to stabilize specific features of a dynamic output.

  14. Current and calcium responses to local activation of axonal NMDA receptors in developing cerebellar molecular layer interneurons.

    Directory of Open Access Journals (Sweden)

    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.

  15. Generation of realistic tsunami waves using a bottom-tilting wave maker

    Science.gov (United States)

    Park, Yong Sung; Hwang, Jin Hwan

    2016-11-01

    Tsunamis have caused more than 260,000 human losses and 250 billion in damage worldwide in the last ten years. Observations made during 2011 Japan Tohoku Tsunami revealed that the commonly used waves (solitary waves) to model tsunamis are at least an order-of-magnitude shorter than the real tsunamis, which calls for re-evaluation of the current understanding of tsunamis. To prompt the required paradigm shift, a new wave generator, namely the bottom-tilting wave generator, has been developed at the University of Dundee. The wave tank is fitted with an adjustable slope and a bottom flap hinged at the beginning of the slope. By moving the bottom flap up and down, we can generate very long waves. Here we will report characteristics of waves generated by simple bottom motions, either moving it upward or downward from an initial displacement ending it being horizontal. Two parameters, namely the initial displacement of the bottom and the speed of the motion, determine characteristics of the generated waves. Wave amplitudes scale well with the volume flux of the displaced water. On the other hand, due to combined effects of nonlinearity and dispersion, wavelengths show more complicated relationship with the two bottom motion parameters. We will also demonstrate that by combining simple up and down motions, it is possible to generate waves resembling the one measured during 2011 tsunami. YSP acknowledges financial support from the Royal Society of Edinburgh through the Royal Society of Edinburgh and Scottish Government Personal Research Fellowship Co-Funded by the Marie-Curie Actions.

  16. Predictions for masses of bottom baryons

    CERN Document Server

    Karliner, Marek; Lipkin, Harry J; Rosner, Jonathan L

    2007-01-01

    The recent observation of Sigma_b^{+-} (uub and ddb) and Xi_b^- (dsb) baryons at the Tevatron within 2 MeV of our theoretical predictions provides a strong motivation for applying the same theoretical approach, based on modeling the color hyperfine interaction, to predict the masses of other bottom baryons which might be observed in the foreseeable future. For S-wave qqb states we predict M(Omega_b) = 6052.1+-5.6 MeV, M(Omega^*_b) = 6082.8+-5.6 MeV, and M(Xi_b^0) = 5786.7 +- 3.0 MeV. For states with one unit of orbital angular momentum between the b quark and the two light quarks we predict M(Lambda_{b[1/2]}) = 5929+-2 MeV, M(Lambda_{b[3/2]}) = 5940+-2 MeV, M(Xi_{b[1/2]}) = 6106+-4 MeV, and M(Xi_{b[3/2]}) = 6115+-4 MeV.

  17. Ocean Bottom Seismograph Performance during the Cascadia Initiative

    Science.gov (United States)

    Aderhold, K.; Evers, B.

    2015-12-01

    The Ocean Bottom Seismograph Instrument Pool (OBSIP) provides instrumentation and operations support for the Cascadia Initiative community experiment. This experiment investigates geophysical processes across the Cascadia subduction zone through a combination of onshore and offshore seismic data. The recovery of Year 4 instruments in September 2015 marks the conclusion of a multi-year experiment that utilized 60 ocean-bottom seismographs (OBSs) specifically designed for the subduction zone boundary, including shallow/deep water deployments and active fisheries. The new instruments feature trawl-resistant enclosures designed by Lamont-Doherty Earth Observatory (LDEO) and Scripps Institution of Oceanography (SIO) for shallow deployment [water depth ≤ 500 m], as well as new deep-water instruments designed by Woods Hole Oceanographic Institute (WHOI). Existing OBSIP instruments were also deployed along the Blanco Transform Fault and on the Gorda Plate through complementary experiments. Stations include differential pressure gauges (DPG) and absolute pressure gauges (APG). All data collected from the Cascadia, Blanco, and Gorda deployments will be freely available through the Incorporated Research Institutions for Seismology (IRIS) Data Management Center (DMC). The Cascadia Initiative is the largest amphibious seismic experiment undertaken to date and demonstrates an effective structure for community experiments through collaborative efforts from the Cascadia Initiative Expedition Team (CIET), OBSIP (institutional instrument contributors [LDEO, SIO, WHOI] and Management Office [IRIS]), and the IRIS DMC. The successes and lessons from Cascadia are a vital resource for the development of a Subduction Zone Observatory (SZO). To guide future efforts, we investigate the quality of the Cascadia OBS data using basic metrics such as instrument recovery and more advanced metrics such as noise characteristics through power spectral density analysis. We also use this broad and

  18. Analysis of the gamma spectrometry {sup 210}Pb radioisotope in river bottom sediments of the hydrographic sub-basins around the UTM-Caldas

    Energy Technology Data Exchange (ETDEWEB)

    Dutra, Pedro H.; Carvalho Filho, Carlos A.; Moreira, Rubens M.; Menezes, Maria Angela B.C.; Oliveira, Aline F.G. de, E-mail: pedrohenrique.dutra@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Silva, Nivaldo C., E-mail: ncsilva@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Viana, Valquiria F.L., E-mail: valquiria.flviana@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Instituto de Ciencias Biologicas

    2015-07-01

    The uranium mine of Caldas, currently named Ore Treatment Unit (UTM-Caldas), is sited at the Pocos de Caldas Plateau (Minas Gerais State) and was the first uranium mineral-industrial complex in Brazil. It has been installed since 1982 and now it is under decommissioning process. Taking into account the potential sources of contamination and the assessment of the impact of the mine, based on the presence of radionuclides from the radioactive decay series of natural {sup 238}U, the aim of the article is to present the distribution of {sup 210}Pb in the stream bottom sediments of the study area that consists of the Taquari watershed, sub-divided by its three major sub-basins: Consulta stream, Soberbo stream and Taquari river. The radionuclide activity concentrations were measured in sediment samples that were collected in twelve collecting points, during four sampling campaigns, carried out in the dry and rainy seasons of 2010 and 2011. The results of the {sup 210}Pb concentration activity were obtained by gamma spectrometry performed in both high and low energy CANBERRA detectors. The results point out that the UTM-Caldas is influencing on the bottom sediment distribution of {sup 210}Pb activity in its neighborhood. However, a more detailed study should be done in order to identify if there is another source of {sup 210}Pb in the study area, such as a geogenic anomaly, that may contributing to the local increment of {sup 210}Pb activity. (author)

  19. L-Tyrosine-loaded nanoparticles increase the antitumoral activity of direct electric current in a metastatic melanoma cell model

    Directory of Open Access Journals (Sweden)

    Vânia Emerich Bucco de Campos

    2010-11-01

    Full Text Available Vânia Emerich Bucco de Campos1, Cesar Augusto Antunes Teixeira1, Venicio Feo da Veiga2, Eduardo Ricci Júnior1, Carla Holandino11Departamento de Medicamentos, Faculdade de Farmácia, 2Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, BrazilAbstract: Inhibition of tumor growth induced by treatment with direct electric current (DC has been reported in several models. One of the mechanisms responsible for the antitumoral activity of DC is the generation of oxidative species, known as chloramines. With the aim of increasing chloramine production in the electrolytic medium and optimizing the antitumoral effects of DC, poly(e-caprolactone (PCL nanoparticles (NPs loaded with the amino acid tyrosine were obtained. The physical–chemical characterization showed that the NPs presented size in nanometric range and monomodal distribution. A slightly negative electrokinetic potential was also found in both blank NPs and L-tyrosine-loaded PCL NPs. The yield of the loading process was approximately 50%. Within 3 h of dissolution assay, a burst release of about 80% L-tyrosine was obtained. The in vitro cytotoxicity of DC was significantly increased when associated with L-tyrosine-loaded NPs, using a murine multidrug-resistant melanoma cell line model. This study showed that the use of the combination of nanotechnology and DC has a promising antineoplastic potential and opens a new perspective in cancer therapy.Keywords: direct electric current, nanotechnology, cancer therapy, L-tyrosine, B16F10 cells

  20. Copper speciation in municipal solid waste incinerator bottom ash leachates; Kopparformer i lakvatten fraan energiaskor

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Susanna; Gustafsson, Jon Petter [Royal Inst. of Tech., Stockholm (Sweden); Schaik, Joris van; Berggren Kleja, Dan [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden); Hees, Patrick van [Oerebro Univ. (Sweden)

    2006-03-15

    The formation of copper (Cu) complexes with dissolved organic carbon (DOC) in bottom ash from municipal solid waste incineration (MSWI) may increase the total amount of Cu released but at the same time reduce its toxicity. In this study, DOC in a MSWI bottom ash leachate was characterized and the Cu-binding properties of different DOC fractions in the ash leachate and in a soil solution were studied. This knowledge may be used for improved environmental assessment of MSWI bottom ash in engineering applications. The Cu{sup 2+} activity at different pH values was measured potentiometrically using a Cu-ion selective electrode (Cu-ISE). Experimental copper complexation results were compared to speciation calculations made in Visual MINTEQ with the NICA-Donnan model and the Stockholm Humic Model (SHM). The MSWI bottom ash leachate contained a larger proportion of hydrophilic organic carbon than the investigated soil solution and other natural waters. The hydrophilic fraction of both samples showed Cu{sup 2+} binding properties similar to that of the bulk, cation-exchanged, leachate. For the ash leachate, the pH dependence of the Cu activity was not correctly captured by neither the SHM nor the NICA-Donnan model, but for the soil solution the model predictions of Cu speciation were in good agreement with the obtained results. The complex formation properties of the ash DOC appears to be less pH-dependent than what is assumed for DOC in natural waters. Hence, models calibrated for natural DOC may give inconsistent simulations of Cu-DOC complexation in MSWI bottom ash leachate. A Biotic Ligand Model for Daphnia Magna was used to provide an estimate of the copper concentrations at LC50 for a simulated bottom ash leachate. It was concluded that the Cu concentrations in certain bottom ash leachates are high enough to pose an ecotoxicological risk; however, after dilution and soil sorption, the risks for neighboring water bodies are most likely negligible. Three processes were