WorldWideScience

Sample records for network clamp works

  1. Analysis of the Pallet Clamping Conditions in Work Positioning

    Directory of Open Access Journals (Sweden)

    L. A. Kolesnikov

    2016-01-01

    Full Text Available Pallets of automatic transfer lines serve as the technological and work-transfer equipment. However, their design is based on the general principles of designing machine accessories. Calculation of the basic design parameters of work based on their functioning features is fairly relevant.In pallet transfer movement over work positioning there is a mismatch between axes of the basic bushing of a pallet and the clamping locks of positioning. The paper identifies the factors influencing it, and defines the conditions to ensure the trouble-free clamping lock. The circular and rhombic clamping of pallet is simultaneous. Further, a clamping load is calculated from the pallet mass (together with the work-piece and the geometric parameters of the pallet clamping.The paper reveals three movement stages of the clamping lock in a vertical plane when setting the pallet in work positioning:- a clamping lock free play till it encounters with the location bushing;- a clamping lock play length when the lead-in chamfer contacts the bushing chamfer;- a clamping lock play length over the circular surface of bushing.The study of this process has allowed us to calculate the time of pallet clamping and dynamic loads acting on the clamping lock. These calculations made it possible to calculate the required diameter of the clamping lock. The presented calculations allow a reasonable assigning the main design parameters of work positioning for the pallet automatic lines.

  2. The ATP Sites of AAA+ Clamp Loaders Work Together as a Switch to Assemble Clamps on DNA*

    Science.gov (United States)

    Marzahn, Melissa R.; Hayner, Jaclyn N.; Finkelstein, Jeff; O'Donnell, Mike; Bloom, Linda B.

    2014-01-01

    Clamp loaders belong to a family of proteins known as ATPases associated with various cellular activities (AAA+). These proteins utilize the energy from ATP binding and hydrolysis to perform cellular functions. The clamp loader is required to load the clamp onto DNA for use by DNA polymerases to increase processivity. ATP binding and hydrolysis are coordinated by several key residues, including a conserved Lys located within the Walker A motif (or P-loop). This residue is required for each subunit to bind ATP. The specific function of each ATP molecule bound to the Saccharomyces cerevisiae clamp loader is unknown. A series of point mutants, each lacking a single Walker A Lys residue, was generated to study the effects of abolishing ATP binding in individual clamp loader subunits. A variety of biochemical assays were used to analyze the function of ATP binding during discrete steps of the clamp loading reaction. All mutants reduced clamp binding/opening to different degrees. Decreased clamp binding activity was generally correlated with decreases in the population of open clamps, suggesting that differences in the binding affinities of Walker A mutants stem from differences in stabilization of proliferating cell nuclear antigen in an open conformation. Walker A mutations had a smaller effect on DNA binding than clamp binding/opening. Our data do not support a model in which each ATP site functions independently to regulate a different step in the clamp loading cycle to coordinate these steps. Instead, the ATP sites work in unison to promote conformational changes in the clamp loader that drive clamp loading. PMID:24436332

  3. The ATP sites of AAA+ clamp loaders work together as a switch to assemble clamps on DNA.

    Science.gov (United States)

    Marzahn, Melissa R; Hayner, Jaclyn N; Finkelstein, Jeff; O'Donnell, Mike; Bloom, Linda B

    2014-02-28

    Clamp loaders belong to a family of proteins known as ATPases associated with various cellular activities (AAA+). These proteins utilize the energy from ATP binding and hydrolysis to perform cellular functions. The clamp loader is required to load the clamp onto DNA for use by DNA polymerases to increase processivity. ATP binding and hydrolysis are coordinated by several key residues, including a conserved Lys located within the Walker A motif (or P-loop). This residue is required for each subunit to bind ATP. The specific function of each ATP molecule bound to the Saccharomyces cerevisiae clamp loader is unknown. A series of point mutants, each lacking a single Walker A Lys residue, was generated to study the effects of abolishing ATP binding in individual clamp loader subunits. A variety of biochemical assays were used to analyze the function of ATP binding during discrete steps of the clamp loading reaction. All mutants reduced clamp binding/opening to different degrees. Decreased clamp binding activity was generally correlated with decreases in the population of open clamps, suggesting that differences in the binding affinities of Walker A mutants stem from differences in stabilization of proliferating cell nuclear antigen in an open conformation. Walker A mutations had a smaller effect on DNA binding than clamp binding/opening. Our data do not support a model in which each ATP site functions independently to regulate a different step in the clamp loading cycle to coordinate these steps. Instead, the ATP sites work in unison to promote conformational changes in the clamp loader that drive clamp loading.

  4. Characterization of a patch-clamp microchannel array towards neuronal networks analysis

    DEFF Research Database (Denmark)

    Alberti, Massimo; Snakenborg, Detlef; Lopacinska, Joanna M.

    2010-01-01

    for simultaneous patch clamping of cultured cells or neurons in the same network. A disposable silicon/silicon dioxide (Si/SiO2) chip with a microhole array was integrated in a microfluidic system for cell handling, perfusion and electrical recording. Fluidic characterization showed that our PC mu CA can work...... theory, but the capacitance is still too high for high resolution recording. The system was tested on HeLa cells: successful cell trapping with a sealing of 40 M Omega was recorded. Modification of the Si/SiO2 chip is needed in order to achieve a better sealing and long-term cell culturing in the PC mu...

  5. Planar patch clamp for neuronal networks--considerations and future perspectives.

    Science.gov (United States)

    Bosca, Alessandro; Martina, Marzia; Py, Christophe

    2014-01-01

    The patch-clamp technique is generally accepted as the gold standard for studying ion channel activity allowing investigators to either "clamp" membrane voltage and directly measure transmembrane currents through ion channels, or to passively monitor spontaneously occurring intracellular voltage oscillations. However, this resulting high information content comes at a price. The technique is labor-intensive and requires highly trained personnel and expensive equipment. This seriously limits its application as an interrogation tool for drug development. Patch-clamp chips have been developed in the last decade to overcome the tedious manipulations associated with the use of glass pipettes in conventional patch-clamp experiments. In this chapter, we describe some of the main materials and fabrication protocols that have been developed to date for the production of patch-clamp chips. We also present the concept of a patch-clamp chip array providing high resolution patch-clamp recordings from individual cells at multiple sites in a network of communicating neurons. On this chip, the neurons are aligned with the aperture-probes using chemical patterning. In the discussion we review the potential use of this technology for pharmaceutical assays, neuronal physiology and synaptic plasticity studies.

  6. Artificial neural networks based controller for glucose monitoring during clamp test.

    Directory of Open Access Journals (Sweden)

    Merav Catalogna

    Full Text Available Insulin resistance (IR is one of the most widespread health problems in modern times. The gold standard for quantification of IR is the hyperinsulinemic-euglycemic glucose clamp technique. During the test, a regulated glucose infusion is delivered intravenously to maintain a constant blood glucose concentration. Current control algorithms for regulating this glucose infusion are based on feedback control. These models require frequent sampling of blood, and can only partly capture the complexity associated with regulation of glucose. Here we present an improved clamp control algorithm which is motivated by the stochastic nature of glucose kinetics, while using the minimal need in blood samples required for evaluation of IR. A glucose pump control algorithm, based on artificial neural networks model was developed. The system was trained with a data base collected from 62 rat model experiments, using a back-propagation Levenberg-Marquardt optimization. Genetic algorithm was used to optimize network topology and learning features. The predictive value of the proposed algorithm during the temporal period of interest was significantly improved relative to a feedback control applied at an equivalent low sampling interval. Robustness to noise analysis demonstrates the applicability of the algorithm in realistic situations.

  7. Post clamp

    Science.gov (United States)

    Ramsey, John K. (Inventor); Meyn, Erwin H. (Inventor)

    1990-01-01

    A pair of spaced collars are mounted at right angles on a clamp body by retaining rings which enable the collars to rotate with respect to the clamp body. Mounting posts extend through aligned holes in the collars and clamp body. Each collar can be clamped onto the inserted post while the clamp body remains free to rotate about the post and collar. The clamp body is selectively clamped onto each post.

  8. Metal Work: Making an Adjustable C-Clamp. Kit No. 23. Instructor's Manual [and] Student Learning Activity Manual.

    Science.gov (United States)

    White, Jim

    An instructor's manual and student activity guide on making an adjustable C-clamp are provided in this set of prevocational education materials which focuses on the vocational area of trade and industry (metal work). (This set of materials is one of ninety-two prevocational education sets arranged around a cluster of seven vocational offerings:…

  9. Mechanism of opening a sliding clamp.

    Science.gov (United States)

    Douma, Lauren G; Yu, Kevin K; England, Jennifer K; Levitus, Marcia; Bloom, Linda B

    2017-09-29

    Clamp loaders load ring-shaped sliding clamps onto DNA where the clamps serve as processivity factors for DNA polymerases. In the first stage of clamp loading, clamp loaders bind and stabilize clamps in an open conformation, and in the second stage, clamp loaders place the open clamps around DNA so that the clamps encircle DNA. Here, the mechanism of the initial clamp opening stage is investigated. Mutations were introduced into the Escherichia coli β-sliding clamp that destabilize the dimer interface to determine whether the formation of an open clamp loader-clamp complex is dependent on spontaneous clamp opening events. In other work, we showed that mutation of a positively charged Arg residue at the β-dimer interface and high NaCl concentrations destabilize the clamp, but neither facilitates the formation of an open clamp loader-clamp complex in experiments presented here. Clamp opening reactions could be fit to a minimal three-step 'bind-open-lock' model in which the clamp loader binds a closed clamp, the clamp opens, and subsequent conformational rearrangements 'lock' the clamp loader-clamp complex in a stable open conformation. Our results support a model in which the E. coli clamp loader actively opens the β-sliding clamp. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. Replication Clamps and Clamp Loaders

    Science.gov (United States)

    Hedglin, Mark; Kumar, Ravindra; Benkovic, Stephen J.

    2013-01-01

    To achieve the high degree of processivity required for DNA replication, DNA polymerases associate with ring-shaped sliding clamps that encircle the template DNA and slide freely along it. The closed circular structure of sliding clamps necessitates an enzyme-catalyzed mechanism, which not only opens them for assembly and closes them around DNA, but specifically targets them to sites where DNA synthesis is initiated and orients them correctly for replication. Such a feat is performed by multisubunit complexes known as clamp loaders, which use ATP to open sliding clamp rings and place them around the 3′ end of primer–template (PT) junctions. Here we discuss the structure and composition of sliding clamps and clamp loaders from the three domains of life as well as T4 bacteriophage, and provide our current understanding of the clamp-loading process. PMID:23545418

  11. Rigid clamp

    Science.gov (United States)

    Benavides, Gilbert L.; Burt, Jack D.

    1994-01-01

    The invention relates to a clamp mechanism that can be used to attach or temporarily support objects inside of tubular goods. The clamp mechanism can also be modified so that it grips objects. The clamp has a self-centering feature to accommodate out-of-roundness or other internal defections in tubular objects such as pipe. A plurality of clamping shoes are expanded by a linkage which is preferably powered by a motor to contact the inside of a pipe. The motion can be reversed and jaw elements can be connected to the linkage so as to bring the jaws together to grab an object.

  12. NetWorking News

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Iversen, Ole Sejer; Dindler, Christian

    with adults or children. However there is a need for new methods to support communication and collaboration between designers and children. This article proposes a new method for understandings children’s appropriation of new technology in an interactive workshop setting. The method, which we call...... the Networking News workshop, offers an opportunity to make first hand studies of children’s IT supported social activities in an informal classroom setting....

  13. NetWorking News

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Iversen, Ole Sejer; Dindler, Christian

    For many years cooperative design was primarily concerned with the development of IT supported systems for professional users. However, the cooperative design approach can embrace other social practices such as children’s everyday life. At a methodological level there is no difference in designin...... the Networking News workshop, offers an opportunity to make first hand studies of children’s IT supported social activities in an informal classroom setting....

  14. Charlie's Clamp.

    Science.gov (United States)

    Tarino, Janet Z.

    1998-01-01

    Presents a version of the crush-the-can demonstration which is a hands-on activity in which students use an inexpensive, easily made holder for the can called Charlie's clamp. Includes some suggestions for the follow-up discussion. (DDR)

  15. Hand-Held Power Clamp

    Science.gov (United States)

    Clancy, J. P.

    1985-01-01

    Tool furnishes large pushing or pulling forces. Device includes two clamping blocks, two clamping plates, and a motor-driven linear actuator with selflocking screw shaft. Power clamp exerts opening or closing force at push of switch. Tool approximately 1 m long. Originally designed to secure payload aboard Space Shuttle, operated with one hand to apply opening or closing force of up to 1,000 lb (4,400 N). Clamp has potential applications as end effector for industrial robots and in rescue work to push or pull wreckage with great force.

  16. Clamp usable as jig and lifting clamp

    Science.gov (United States)

    Tsuyama, Yoshizo

    1976-01-01

    There is provided a clamp which is well suited for use as a lifting clamp for lifting and moving materials of assembly in a shipyard, etc. and as a pulling jig in welding and other operations. The clamp comprises a clamp body including a shackle for engagement with a pulling device and a slot for receiving an article, and a pair of jaws provided on the leg portions of the clamp body on the opposite sides of the slot to grip the article in the slot, one of said jaws consisting of a screw rod and the other jaw consisting of a swivel jaw with a spherical surface, whereby when the article clamped in the slot by the pair of jaws tends to slide in any direction with respect to the clamp body, the article is more positively gripped by the pair of jaws.

  17. Work and Community in Networked Organizations

    OpenAIRE

    Haythornthwaite, Caroline

    2017-01-01

    When computer networks link people as well as machines, they become social networks. Such computer-supported social networks (CSSNs) are becoming important bases of virtual communities, computer-supported co-operative work, and telework. We review our Toronto-based Virtually Social Research Group’s analysis of scholarly networks and on-line workgroups. We find that CSSNs sustain strong, intermediate and weak ties that provide information and social support in both specialized and broadly-base...

  18. Quick-attach clamp

    Science.gov (United States)

    Vano, A. E.

    1968-01-01

    Clamp of the slideable jaw type can be applied to moving lines such as cables or ropes. The clamp has a trigger-operated jaw that can be attached to a redrop parachute on a moving tow cable. The trigger mechanism maintains the jaws retracted in the housing until they are released for clamping.

  19. Photovoltaic panel clamp

    Science.gov (United States)

    Brown, Malcolm P.; Mittan, Margaret Birmingham; Miros, Robert H. J.; Stancel, Robert

    2013-03-19

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  20. Radial wedge flange clamp

    Science.gov (United States)

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  1. Clamp Restrains Pressure Line

    Science.gov (United States)

    Aliberti, J. A.

    1982-01-01

    Safety restraint protects people and property if a high-pressure fitting fails. As long as pressure line remains attached at the fitting, clamp exerts essentially no force on hose. If fitting fails, force of fluid leaving free end of hose causes the cam on the clamp to compress hose with a positive locking action.

  2. Quick action clamp

    Science.gov (United States)

    Calco, Frank S. (Inventor)

    1991-01-01

    A quick release toggle clamp that utilizes a spring that requires a deliberate positive action for disengagement is presented. The clamp has a sliding bolt that provides a latching mechanism. The bolt is moved by a handle that tends to remain in an engaged position while under tension.

  3. Loading dynamics of a sliding DNA clamp.

    Science.gov (United States)

    Cho, Won-Ki; Jergic, Slobodan; Kim, Daehyung; Dixon, Nicholas E; Lee, Jong-Bong

    2014-06-23

    Sliding DNA clamps are loaded at a ss/dsDNA junction by a clamp loader that depends on ATP binding for clamp opening. Sequential ATP hydrolysis results in closure of the clamp so that it completely encircles and diffuses on dsDNA. We followed events during loading of an E. coli β clamp in real time by using single-molecule FRET (smFRET). Three successive FRET states were retained for 0.3 s, 0.7 s, and 9 min: Hydrolysis of the first ATP molecule by the γ clamp loader resulted in closure of the clamp in 0.3 s, and after 0.7 s in the closed conformation, the clamp was released to diffuse on the dsDNA for at least 9 min. An additional single-molecule polarization study revealed that the interfacial domain of the clamp rotated in plane by approximately 8° during clamp closure. The single-molecule polarization and FRET studies thus revealed the real-time dynamics of the ATP-hydrolysis-dependent 3D conformational change of the β clamp during loading at a ss/dsDNA junction. © 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

  4. Clamp-mount device

    Science.gov (United States)

    Clark, K. H. (Inventor)

    1983-01-01

    A clamp-mount device is disclosed for mounting equipment to an associated I-beam and the like structural member of the type having oppositely extending flanges wherein the device comprises a base and a pair of oppositely facing clamping members carried diagonally on the base clamping flanges therebetween and having flange receiving openings facing one another. Lock means are carried diagonally by the base opposite the clamping members locking the flanges in the clamping members. A resilient hub is carried centrally of the base engaging and biasing a back side of the flanges maintaining tightly clamped and facilitating use on vertical as well as horizontal members. The base turns about the hub to receive the flanges within the clamping members. Equipment may be secured to the base by any suitable means such as bolts in openings. Slidable gate latches secure the hinged locks in an upright locking position. The resilient hub includes a recess opening formed in the base and a rubber-like pad carried in this opening being depressably and rotatably carried therein.

  5. Bend-absorbing clamp

    Science.gov (United States)

    Abbott, J. R.; Valencia, B., Jr.

    1979-01-01

    Compact, inexpensive clamp for flexible cables or rigid tubes absorbs vibrations and other motion. It accomodates wide range of dimensions, and saves space by eliminating pigtails or bellows commonly used to absorb linear movement or vibrations

  6. How a DNA polymerase clamp loader opens a sliding clamp

    OpenAIRE

    Kelch, Brian A.; Makino, Debora L.; O’Donnell, Mike; Kuriyan, John

    2011-01-01

    Processive chromosomal replication relies on sliding DNA clamps, which are loaded onto DNA by pentameric clamp loader complexes belonging to the AAA+ family of ATPases. We present structures for the ATP-bound state of the clamp loader complex from bacteriophage T4, bound to an open clamp and primer-template DNA. The clamp loader traps a spiral conformation of the open clamp so that both the loader and the clamp match the helical symmetry of DNA. One structure reveals that ATP has been hydroly...

  7. How a DNA polymerase clamp loader opens a sliding clamp

    Science.gov (United States)

    Kelch, Brian A.; Makino, Debora L.; O’Donnell, Mike; Kuriyan, John

    2012-01-01

    Processive chromosomal replication relies on sliding DNA clamps, which are loaded onto DNA by pentameric clamp loader complexes belonging to the AAA+ family of ATPases. We present structures for the ATP-bound state of the clamp loader complex from bacteriophage T4, bound to an open clamp and primer-template DNA. The clamp loader traps a spiral conformation of the open clamp so that both the loader and the clamp match the helical symmetry of DNA. One structure reveals that ATP has been hydrolyzed in one subunit, and suggests that clamp closure and ejection of the loader involves disruption of the ATP-dependent match in symmetry. The structures explain how synergy between the loader, the clamp and DNA can trigger ATP hydrolysis and release of the closed clamp on DNA. PMID:22194570

  8. Clamp Secures Material to Cylinder Base

    Science.gov (United States)

    Tam, Y. S.

    1985-01-01

    Two-part clamp assembled around pipe or post, ends not free. Resistance welding clamp to post and locking ring to lower part of clamp permanently fixes clamp in place, preventing thermal cycling from loosening clamp.

  9. Networking as a new form of work of school libraries

    Directory of Open Access Journals (Sweden)

    Валерий Константинович Капранов

    2012-03-01

    Full Text Available The article describes a new form of work of school libraries on the basis of network interaction; provides conditions for the creation, described the structure and benefits of networking in comparison with traditional forms of work.

  10. Clamp for detonating fuze

    Science.gov (United States)

    Holderman, E. J.

    1968-01-01

    Quick acting clamp provides physical support for a closely confined detonating fuse in an application requiring removal and replacement at frequent intervals during test. It can be designed with a base of any required strength and configuration to permit the insertion of an object.

  11. The β Sliding Clamp Closes around DNA prior to Release by the Escherichia coli Clamp Loader γ Complex*

    Science.gov (United States)

    Hayner, Jaclyn N.; Bloom, Linda B.

    2013-01-01

    Escherichia coli γ complex clamp loader functions to load the β sliding clamp onto sites of DNA replication and repair. The clamp loader uses the energy of ATP binding and hydrolysis to drive conformational changes allowing for β binding and opening, DNA binding, and then release of the β·DNA complex. Although much work has been done studying the sliding clamp and clamp loader mechanism, kinetic analysis of the events following β·γ complex·DNA formation is not complete. Using fluorescent clamp closing and release assays, we show that β closing is faster than β release, indicating that γ complex closes β before releasing it around DNA. Using a fluorescent ATP hydrolysis assay, we show that there is a burst of ATP hydrolysis before β closing and that β release may be the rate-limiting step in the overall clamp loading reaction. The combined use of these fluorescent assays provides a unique perspective into the E. coli clamp loader by providing a measure of the relative timing of different events in the clamp loading reaction, helping to elucidate the complicated clamp loading mechanism. PMID:23161545

  12. Developing networks to support science teachers work

    DEFF Research Database (Denmark)

    Sillasen, Martin Krabbe; Valero, Paola

    2012-01-01

    In educational research literature constructing networks among practitioners has been suggested as a strategy to support teachers’ professional development (Huberman, 1995; Jackson & Temperley, 2007; Van Driel, Beijaard, & Verloop, 2001). The purpose of this paper is to report on a study about how...... networks provide opportunities for teachers from different schools to collaborate on improving the quality of their own science teaching practices. These networks exist at the meso-level of the educational system between the micro-realities of teachers’ individual practice and the macro-level, where...... to develop collaborative activities in primary science teacher communities in schools to improve individual teachers practice and in networks between teachers from different schools in each municipality. Each network was organized and moderated by a municipal science coordinator....

  13. Dopamine D1 signaling organizes network dynamics underlying working memory.

    Science.gov (United States)

    Roffman, Joshua L; Tanner, Alexandra S; Eryilmaz, Hamdi; Rodriguez-Thompson, Anais; Silverstein, Noah J; Ho, New Fei; Nitenson, Adam Z; Chonde, Daniel B; Greve, Douglas N; Abi-Dargham, Anissa; Buckner, Randy L; Manoach, Dara S; Rosen, Bruce R; Hooker, Jacob M; Catana, Ciprian

    2016-06-01

    Local prefrontal dopamine signaling supports working memory by tuning pyramidal neurons to task-relevant stimuli. Enabled by simultaneous positron emission tomography-magnetic resonance imaging (PET-MRI), we determined whether neuromodulatory effects of dopamine scale to the level of cortical networks and coordinate their interplay during working memory. Among network territories, mean cortical D1 receptor densities differed substantially but were strongly interrelated, suggesting cross-network regulation. Indeed, mean cortical D1 density predicted working memory-emergent decoupling of the frontoparietal and default networks, which respectively manage task-related and internal stimuli. In contrast, striatal D1 predicted opposing effects within these two networks but no between-network effects. These findings specifically link cortical dopamine signaling to network crosstalk that redirects cognitive resources to working memory, echoing neuromodulatory effects of D1 signaling on the level of cortical microcircuits.

  14. WORK ON TELEPHONE NETWORK LEP SITE

    CERN Multimedia

    2000-01-01

    The telephone service will make modifications on the LEP network the 12th December 2000 from 5.30pm. This will cause disturbances on telephone connections on the whole LEP area. For more information please call 160026.

  15. Clamp and Gas Nozzle for TIG Welding

    Science.gov (United States)

    Gue, G. B.; Goller, H. L.

    1982-01-01

    Tool that combines clamp with gas nozzle is aid to tungsten/inert-gas (TIG) welding in hard-to-reach spots. Tool holds work to be welded while directing a stream of argon gas at weld joint, providing an oxygen-free environment for tungsten-arc welding.

  16. Networks and Project Work: Alternative Pedagogies for Writing with Computers.

    Science.gov (United States)

    Susser, Bernard

    1993-01-01

    Describes three main uses of computers for writing as a social activity: networking, telecommunications, and project work. Examines advantages and disadvantages of teaching writing on a network. Argues that reports in the literature and the example of an English as a foreign language writing class show that project work shares most of the…

  17. Comparison of off-clamp partial nephrectomy and on-clamp partial nephrectomy: a systematic review and meta-analysis.

    Science.gov (United States)

    Trehan, Abhishek

    2014-01-01

    To compare peri- and postoperative variables, surgical complications, oncological outcomes and renal outcomes of off-clamp partial nephrectomy (PN) and on-clamp PN. A systematic search of the electronic databases, including MEDLINE, Embase and Cochrane Library, was performed. The pooled estimates of tumour size, operative time, estimated blood loss, length of stay, overall complications, transfusion rates, urinary leaks, positive surgical margins and eGFR were calculated. 14 studies were included. There was no significant difference between off-clamp PN and on-clamp PN in terms of tumour size, operative time, estimated blood loss, length of stay, overall complications, transfusion rates, urinary leaks, and positive surgical margins. However, a non-statistically significant trend towards increased blood loss (p = 0.12) and transfusion rates (p = 0.07) in those undergoing off-clamp PN was noted. Off-clamp PN was associated with a significantly lower reduction in eGFR than on-clamp PN (standardised weighted mean difference 0.27, 95% CI 0.14, 0.40, p clamp PN may be associated with improved long-term renal outcomes when compared to on-clamp PN with no difference in in peri- and postoperative variables, surgical complications and oncological outcomes. However, the meta-analysis was limited by the design of the underlying studies, and hence further work is necessary. 2014 S. Karger AG, Basel.

  18. The Escherichia coli Clamp Loader Can Actively Pry Open the β-Sliding Clamp*

    Science.gov (United States)

    Paschall, Christopher O.; Thompson, Jennifer A.; Marzahn, Melissa R.; Chiraniya, Ankita; Hayner, Jaclyn N.; O'Donnell, Mike; Robbins, Arthur H.; McKenna, Robert; Bloom, Linda B.

    2011-01-01

    Clamp loaders load ring-shaped sliding clamps onto DNA. Once loaded onto DNA, sliding clamps bind to DNA polymerases to increase the processivity of DNA synthesis. To load clamps onto DNA, an open clamp loader-clamp complex must form. An unresolved question is whether clamp loaders capture clamps that have transiently opened or whether clamp loaders bind closed clamps and actively open clamps. A simple fluorescence-based clamp opening assay was developed to address this question and to determine how ATP binding contributes to clamp opening. A direct comparison of real time binding and opening reactions revealed that the Escherichia coli γ complex binds β first and then opens the clamp. Mutation of conserved “arginine fingers” in the γ complex that interact with bound ATP decreased clamp opening activity showing that arginine fingers make an important contribution to the ATP-induced conformational changes that allow the clamp loader to pry open the clamp. PMID:21971175

  19. Project Work in Networked Distance Education

    DEFF Research Database (Denmark)

    Knudsen, Morten; Helbo, Jan; Jensen, Lars Peter

    2000-01-01

    Problem oriented project work has been the foundation for the educational system at Aalborg University since its start 25 years ago. The duration of each student project is one semester, and the students spend half of their time working on the project in groups of typically 5-6 persons......-study, whereas the project study form is based on collaboration and dialogue. Consequently, successful implementation of project work in distance education requires extensive utilisation of new information and communication technology. In this paper the experiences of project work in a new Master of Industrial...... devoted to courses and the other half to project work. A computer conference system, LuvitÒ provides facilities for the courses, as well as structured synchronous and asynchronous communication. Eight times per year two-day seminars are held at the university for intensive lectures, project work...

  20. The European Cancer and Work Network: CANWON

    NARCIS (Netherlands)

    de Boer, Angela G. E. M.

    2014-01-01

    The number of cancer survivors is rapidly growing due to improved treatment and ageing population. Almost half of cancer patients will experience a cancer diagnosis during working age when career and work-related issues play an important role. Many cancer survivors are at risk for unemployment which

  1. Canonical correlation between LFP network and spike network during working memory task in rat.

    Science.gov (United States)

    Yi, Hu; Zhang, Xiaofan; Bai, Wenwen; Liu, Tiaotiao; Tian, Xin

    2015-08-01

    Working memory refers to a system to temporary holding and manipulation of information. Previous studies suggested that local field potentials (LFPs) and spikes as well as their coordination provide potential mechanism of working memory. Popular methods for LFP-spike coordination only focus on the two modality signals, isolating each channel from multi-channel data, ignoring the entirety of the networked brain. Therefore, we investigated the coordination between the LFP network and spike network to achieve a better understanding of working memory. Multi-channel LFPs and spikes were simultaneously recorded in rat prefrontal cortex via microelectrode array during a Y-maze working memory task. Functional connectivity in the LFP network and spike network was respectively estimated by the directed transfer function (DTF) and maximum likelihood estimation (MLE). Then the coordination between the two networks was quantified via canonical correlation analysis (CCA). The results show that the canonical correlation (CC) varied during the working memory task. The CC-curve peaked before the choice point, describing the coordination between LFP network and spike network enhanced greatly. The CC value in working memory showed a significant higher level than inter-trial interval. Our results indicate that the enhanced canonical correlation between the LFP network and spike network may provide a potential network integration mechanism for working memory. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Project Work in Networked Distance Education

    DEFF Research Database (Denmark)

    Knudsen, Morten; Helbo, Jan; Jensen, Lars Peter

    2000-01-01

    Problem oriented project work has been the foundation for the educational system at Aalborg University since its start 25 years ago. The duration of each student project is one semester, and the students spend half of their time working on the project in groups of typically 5-6 persons...... Information Technology distance education is described. The program is offered through Open University, and the students have a BSc degree or equivalent and at least 2 years of relevant professional experience - and a full-time job. The students are assumed to study 20 hours per week, half of the time being...

  3. Work of the European Haemovigilance Network (EHN).

    Science.gov (United States)

    Faber, Jean-Claude

    2004-02-01

    Haemovigilance has become a crucial part of the blood safety concept. In the Member States of the European Union, national haemovigilance systems are already in place or are developing. With the coming into force of the European Blood Directive 2002/98/EC, Community haemovigilance has become a priority: cooperation between the national haemovigilance systems will be of vital interest. The process of collaboration has already been initiated some years ago by the European Haemovigilance Network (EHN) with the following objectives: to favour the exchange of valid information between its members, to increase rapid alert/early warning between the members, to encourage joint activities between the members and to undertake educational activities relating to haemovigilance. This has been achieved by the EHN by developing and maintaining a website [http://www.ehn-org.net], by establishing a system for rapid alert and early warning (RAS), by discussing on all kinds of definitions relevant to haemovigilance, initiating standardisation of processes and forms (developing a common "mother matrix"), by starting with the compilation and analysis of European data (generated by the national haemovigilance systems in Europe) and by organising annual European Haemovigilance Seminars, where all these items are discussed. As in the past, the EHN will continue in the future to play a major role in promoting European haemovigilance.

  4. [Working Temperature Predication of Artificial Heart Based on Neural Network].

    Science.gov (United States)

    Li, Qilei; Yang, Ming; Ou, Wenchu; Meng, Fan; Xu, Zihao; Xu, Liang

    2015-03-01

    The purpose of this paper is to achieve a measurement of temperature prediction for artificial heart without sensor, for which the research briefly describes the application of back propagation neural network as well as the optimized, by genetic algorithm, BP network. Owing to the limit of environment after the artificial heart implanted, detectable parameters out of body are taken advantage of to predict the working temperature of the pump. Lastly, contrast is made to demonstrate the prediction result between BP neural network and genetically optimized BP network, by which indicates that the probability is 1.84% with the margin of error more than 1%.

  5. Five-level Z-source diode-clamped inverter

    DEFF Research Database (Denmark)

    Gao, F.; Loh, Poh Chiang; Blaabjerg, Frede

    2010-01-01

    This study proposes a five-level Z-source diode-clamped inverter designed with two intermediate Z-source networks connected between the dc input sources and rear-end inverter circuitry. By partially shorting the Z-source networks, new operating states not previously reported for two-level Z...

  6. Internal V-Band Clamp

    Science.gov (United States)

    Vaughn, Mark R.; Hafenrichter, Everett S.; Chapa, Agapito C.; Harris, Steven M.; Martinez, Marcus J.; Baty, Roy S.

    2006-02-28

    A system for clamping two tubular members together in an end-to-end relationship uses a split ring with a V-shaped outer rim that can engage a clamping surface on each member. The split ring has a relaxed closed state where the ends of the ring are adjacent and the outside diameter of the split ring is less than the minimum inside diameter of the members at their ends. The members are clamped when the split ring is spread into an elastically stretched position where the ring rim is pressed tightly against the interior surfaces of the members. Mechanisms are provided for removing the spreader so the split ring will return to the relaxed state, releasing the clamped members.

  7. Optical RRH working in an all-optical fronthaul network

    Science.gov (United States)

    Zakrzewski, Zbigniew

    2017-12-01

    The paper presents an example of an optical RRH (Remote Radio Head) design, which is equipped with photonic components for direct connection to an all-optical network. The features that can be fulfilled by an all-optical network are indicated to support future 5G mobile networks. The demand for optical bandwidth in fronthaul/midhaul distribution network links, working in D-RoF and A-RoF formats was performed. The increase in demand is due to the very large traffic generated by the Optical Massive-MIMO RRH/RRU will work in format of an Active-Distributed Antenna System (A-DAS). An exemplary next-generation mobile network that will utilize O-RRH and an all-optical backbone is presented. All components of presented network will work in the Centralized/Cloud Radio Access Network (C-RAN) architecture, which is achievable by control with the use of the OpenFlow (OF).

  8. Social networks in nursing work processes: an integrative literature review

    OpenAIRE

    Ana Cláudia Mesquita; Cristina Mara Zamarioli; Francine Lima Fulquini; Emilia Campos de Carvalho; Emilia Luigia Saporiti Angerami

    2017-01-01

    Abstract OBJECTIVE To identify and analyze the available evidence in the literature on the use of social networks in nursing work processes. METHOD An integrative review of the literature conducted in PubMed, CINAHL, EMBASE and LILACS databases in January 2016, using the descriptors social media, social networking, nursing, enfermagem, redes sociais, mídias sociais, and the keyword nursing practice, without year restriction. RESULTS The sample consisted of 27 international articles which w...

  9. Collaborative work and social networks: assessment of university students from Alicante about collaborative work through social networks

    Directory of Open Access Journals (Sweden)

    Laura Ramos Marcillas

    2017-01-01

    Full Text Available The information and communication technologies (ICT has revolutionized education, promoting the development of collaborative work through the use of Web 2.0 tools. In this vein, social networking services gain a special importance. However, the establishment of a collaborative methodology in the university through the use of ICT tools cannot be effective without a good predisposition of students. So, the present investigation aims to know students’ perceptions about collaborative work and social networks. Specifically, the learners are studying Pre-School Education degree at Alicante's University. The goals are focused on knowing students’ attitudes about collaborative work and social networks, knowing their level of experience about these tools, and also analyzing their interest in introducing these tools in the academic world. The instrument for data gathering is a questionnaire. It concludes that the students show a positive attitude towards team work and they are interested in learning to handle some social media.

  10. GGOS working group on ground networks and communications

    Science.gov (United States)

    Pearlman, M.; Altamimi, Z.; Beck, N.; Forsberg, R.; Gurtner, W.; Kenyon, S.; Behrend, D.; Lemoine, F. G.; Ma, C.; Noll, C. E.; hide

    2005-01-01

    Activities of this Working Group include the investigation of the status quo and the development of a plan for full network integration to support improvements in terrestrial reference frame establishment and maintenance, Earth orientation and gravity field monitoring, precision orbit determination, and other geodetic and gravimetric applications required for the long-term observation of global change. This integration process includes the development of a network of fundamental stations with as many co-located techniques as possible, with precisely determined intersystem vectors. This network would exploit the strengths of each technique and minimize the weaknesses where possible. This paper discusses the organization of the working group, the work done to date, and future tasks.

  11. Social networks in nursing work processes: an integrative literature review

    Directory of Open Access Journals (Sweden)

    Ana Cláudia Mesquita

    Full Text Available Abstract OBJECTIVE To identify and analyze the available evidence in the literature on the use of social networks in nursing work processes. METHOD An integrative review of the literature conducted in PubMed, CINAHL, EMBASE and LILACS databases in January 2016, using the descriptors social media, social networking, nursing, enfermagem, redes sociais, mídias sociais, and the keyword nursing practice, without year restriction. RESULTS The sample consisted of 27 international articles which were published between 2011 and 2016. The social networks used were Facebook (66.5%, Twitter (30% and WhatsApp (3.5%. In 70.5% of the studies, social networks were used for research purposes, in 18.5% they were used as a tool aimed to assist students in academic activities, and in 11% for executing interventions via the internet. CONCLUSION Nurses have used social networks in their work processes such as Facebook, Twitter and WhatsApp to research, teach and watch. The articles show several benefits in using such tools in the nursing profession; however, ethical considerations regarding the use of social networks deserve further discussion.

  12. A Dynamic Clamp on Every Rig.

    Science.gov (United States)

    Desai, Niraj S; Gray, Richard; Johnston, Daniel

    2017-01-01

    The dynamic clamp should be a standard part of every cellular electrophysiologist's toolbox. That it is not, even 25 years after its introduction, comes down to three issues: money, the disruption that adding dynamic clamp to an existing electrophysiology rig entails, and the technical prowess required of experimenters. These have been valid and limiting issues in the past, but no longer. Technological advances associated with the so-called maker movement render them moot. We demonstrate this by implementing a fast (∼100 kHz) dynamic clamp system using an inexpensive microcontroller (Teensy 3.6). The overall cost of the system is less than USD$100, and assembling it requires no prior electronics experience. Modifying it-for example, to add Hodgkin-Huxley-style conductances-requires no prior programming experience. The system works together with existing electrophysiology data acquisition systems (for Macintosh, Windows, and Linux); it does not attempt to supplant them. Moreover, the process of assembling, modifying, and using the system constitutes a useful pedagogical exercise for students and researchers with no background but an interest in electronics and programming. We demonstrate the system's utility by implementing conductances as fast as a transient sodium conductance and as complex as the Ornstein-Uhlenbeck conductances of the "point conductance" model of synaptic background activity.

  13. Micromachined patch-clamp apparatus

    Science.gov (United States)

    Okandan, Murat

    2012-12-04

    A micromachined patch-clamp apparatus is disclosed for holding one or more cells and providing electrical, chemical, or mechanical stimulation to the cells during analysis with the patch-clamp technique for studying ion channels in cell membranes. The apparatus formed on a silicon substrate utilizes a lower chamber formed from silicon nitride using surface micromachining and an upper chamber formed from a molded polymer material. An opening in a common wall between the chambers is used to trap and hold a cell for analysis using the patch-clamp technique with sensing electrodes on each side of the cell. Some embodiments of the present invention utilize one or more electrostatic actuators formed on the substrate to provide mechanical stimulation to the cell being analyzed, or to provide information about mechanical movement of the cell in response to electrical or chemical stimulation.

  14. Detailed theoretical investigation and comparison of the cascadability of conventional and gain-clamped SOA gates in multi wavelength optical networks

    DEFF Research Database (Denmark)

    Wolfson, David

    1999-01-01

    A detailed theoretical investigation of the cascadability of GC-SOAs and SOAs in WDM networks is presented. The analysis shows that the cascadability of SOAs is limited by degradation of both extinction ratio and ASE accumulation, whereas the cascadability for GC-SOAs mainly is limited...... by an accumulation af ASE. This result is superior cascadability of GC-SOAs at a channel bit rate of 2,5 Gbit/s in systems with up to at least 16 channels even when compared to short cavity SOA gates....

  15. How to Assess the Quality of Glucose Clamps? Evaluation of Clamps Performed With ClampArt, a Novel Automated Clamp Device.

    Science.gov (United States)

    Benesch, Carsten; Heise, Tim; Klein, Oliver; Heinemann, Lutz; Arnolds, Sabine

    2015-07-01

    There are no widely accepted parameters to assess the quality of glucose clamps. Thus, we selected different parameters describing clamp quality. These parameters were then evaluated in glucose clamps carried out with ClampArt, a novel CE-marked, state-of-the-art fully automated glucose clamp device employing continuous blood glucose (BG) measurements and minute-by-minute adaptations of glucose infusion rate (GIR). Thirty-nine glucose clamps were performed in 10 healthy and 29 subjects with type 1 diabetes (T1DM) (total duration 583 h). ClampArt-based BG measurements were compared with those obtained with a laboratory reference method. Clamp quality was assessed by 5 parameters: (1) difference (mg/dl) of all paired BG measurements of ClampArt versus reference method ("trueness"), (2) coefficient of variation (CV, %) of ClampArt's BG measurements at target clamp level ("precision"), (3) mean absolute relative difference (MARD, %) at target clamp level ("accuracy"), (4) difference (mg/dl) between ClampArt and target BG ("control deviation"), and (5) percentage operational time ("utility"). ClampArt-based BG measurements showed a trueness of 1.2 ± 2.5 mg/dl. CV and MARD at target BG were 5.5 ± 2.1% and 5.3 ± 2.3%, respectively. There were only small deviations from target level (1.2 ± 1.6 mg/dl). Operational time was as high as 95.4% ± 4.1% (means ± SD). The selected parameters seem to be adequate to characterize clamp quality. The novel, fully automated clamp device ClampArt achieves high clamp quality, which in future trials should be compared with other (automated and manual) clamp methods. © 2015 Diabetes Technology Society.

  16. Intimal injury from arterial clamps.

    Science.gov (United States)

    Slayback, J B; Bowen, W W; Hinshaw, D B

    1976-08-01

    Preliminary experimental data have been presented indicating that intimal injury of some degree is a virtually constant finding at the site of application of any arterial occluding clamp. These injuries vary from intimal distortion to complete fracture into the media of the vessel. The degree of injury appears directly proportional to the amount of pressure exerted through a given clamp. Atherosclerotic arteries are particularly subject to severe degrees of intimal injury. Preliminary observations suggest that heparin is not helpful in preventing platelet aggregation and initial thrombus formation at intimal injury sites. The problem of anticoagulation at such injury sites is being studied further.

  17. The Moderating Effect of Network Centrality on the Relationship Between Work Experience Variables and Organizational Commitment

    Science.gov (United States)

    2013-03-01

    network can be personal or social ( Ibarra & Andrews, 1993). While formal networks show the official rules and workings of an organization...THE MODERATING EFFECT OF NETWORK CENTRALITY ON THE RELATIONSHIP BETWEEN WORK EXPERIENCE VARIABLES...

  18. Clamp wins pipe repair prize

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-04-01

    This paper describes the permanent pipeline repair system, developed by Tekmar, which is powered by seawater hydraulics and is easily installed and tested by any workclass remotely operated vehicle (rov). Details are given of the two main components of the system, namely, the diverless high pressure split repair clamp and the rov-operated tool to install it.

  19. How altruism works: An evolutionary model of supply networks

    Science.gov (United States)

    Ge, Zehui; Zhang, Zi-Ke; Lü, Linyuan; Zhou, Tao; Xi, Ning

    2012-02-01

    Recently, supply networks have attracted increasing attention from the scientific community. However, it lacks serious consideration of social preference in Supply Chain Management. In this paper, we develop an evolutionary decision-making model to characterize the effects of suppliers' altruism in supply networks, and find that the performances of both suppliers and supply chains are improved by introducing the role of altruism. Furthermore, an interesting and reasonable phenomenon is discovered that the suppliers' and whole network's profits do not change monotonously with suppliers' altruistic preference, η, but reach the best at η=0.6 and η=0.4, respectively. This work may shed some light on the in-depth understanding of the effects of altruism for both research and commercial applications.

  20. Changing Work and Work-Family Conflict: Evidence from the Work, Family, and Health Network*

    OpenAIRE

    Kelly, Erin L.; Moen, Phyllis; Oakes, J. Michael; Fan, Wen; Okechukwu, Cassandra; Davis, Kelly D.; Hammer, Leslie; Kossek, Ellen; King, Rosalind Berkowitz; Hanson, Ginger; Mierzwa, Frank; Casper, Lynne

    2014-01-01

    Schedule control and supervisor support for family and personal life are work resources that may help employees manage the work-family interface. However, existing data and designs have made it difficult to conclusively identify the effects of these work resources. This analysis utilizes a group-randomized trial in which some units in an information technology workplace were randomly assigned to participate in an initiative, called STAR, that targeted work practices, interactions, and expecta...

  1. To clamp or not to clamp? Long‐term functional outcomes for elective off‐clamp laparoscopic partial nephrectomy

    National Research Council Canada - National Science Library

    Shah, Paras H; George, Arvin K; Moreira, Daniel M; Alom, Manaf; Okhunov, Zhamshid; Salami, Simpa; Waingankar, Nikhil; Schwartz, Michael J; Vira, Manish A; Richstone, Lee; Kavoussi, Louis R

    2016-01-01

    ... is to avoid ischaemia altogether by performing surgery entirely off‐clamp. Several institutions have reported superior renal functional preservation with the off‐clamp compared with the on‐clamp method after elective laparoscopic PN (LPN), where there is a solitary tumour and normal contralateral kidney and preoperative serum creatinine ...

  2. Multifrequency Excitation of a Clamped-Clamped Microbeam

    KAUST Repository

    Jaber, Nizar R.

    2016-01-20

    We present analytical and experimental investigation of an electrically actuated clamped-clamped microbeam under a twosource harmonic excitation. The first frequency is swept around the first mode of vibration where the second one is fixed. These microbeams are fabricated using polyimide as structural layer coated with nickel form top and chromium and gold layers from bottom. We demonstrate the excitation of additive and subtractive type resonance. We show that by properly tuning the frequency and the amplitude of the excitation force, the frequency bandwidth of the resonator is increased. Theoretically, we solved the eigenvalue problem for different axial forces to find the natural frequencies ratio that match the experimental values. Using Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device where using three symmetric mode shapes provided a good agreement with experimental data. © Copyright 2015 by ASME.

  3. Analysis list: Clamp [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Clamp Cell line + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Clamp.1....tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Clamp.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Clam...p.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Clamp.Cell_line.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Cell_line.gml ...

  4. Box Lesion with Single Radiofrequency Clamp.

    Science.gov (United States)

    Shaikhrezai, Kasra; Spadaccio, Cristiano; Hunter, Steven

    2017-04-12

    We introduce a maneuver to perform the box lesion as a part of Cox maze IV procedure with single radiofrequency clamp. The maneuver entails engaging the right pulmonary veins with the clamp, then advancing the clamp jaws underneath the superior vena cava through the transverse sinus to include the roof and the left pulmonary veins in the clamp. We regularly use this technique for box lesion with desirable transmurality. Georg Thieme Verlag KG Stuttgart · New York.

  5. 21 CFR 870.4450 - Vascular clamp.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vascular clamp. 870.4450 Section 870.4450 Food and... CARDIOVASCULAR DEVICES Cardiovascular Surgical Devices § 870.4450 Vascular clamp. (a) Identification. A vascular clamp is a surgical instrument used to occlude a blood vessel temporarily. (b) Classification. Class II...

  6. Social networks in nursing work processes: an integrative literature review.

    Science.gov (United States)

    Mesquita, Ana Cláudia; Zamarioli, Cristina Mara; Fulquini, Francine Lima; Carvalho, Emilia Campos de; Angerami, Emilia Luigia Saporiti

    2017-03-20

    To identify and analyze the available evidence in the literature on the use of social networks in nursing work processes. An integrative review of the literature conducted in PubMed, CINAHL, EMBASE and LILACS databases in January 2016, using the descriptors social media, social networking, nursing, enfermagem, redes sociais, mídias sociais, and the keyword nursing practice, without year restriction. The sample consisted of 27 international articles which were published between 2011 and 2016. The social networks used were Facebook (66.5%), Twitter (30%) and WhatsApp (3.5%). In 70.5% of the studies, social networks were used for research purposes, in 18.5% they were used as a tool aimed to assist students in academic activities, and in 11% for executing interventions via the internet. Nurses have used social networks in their work processes such as Facebook, Twitter and WhatsApp to research, teach and watch. The articles show several benefits in using such tools in the nursing profession; however, ethical considerations regarding the use of social networks deserve further discussion. Identificar e analisar as evidências disponíveis na literatura sobre a utilização de redes sociais nos processos de trabalho em enfermagem. Revisão integrativa da literatura realizada em janeiro de 2016, nas bases de dados PubMed, CINAHL, EMBASE e LILACS, com os descritores social media, social networking, nursing, enfermagem, redes sociais, mídias sociais e a palavra-chave nursing practice, sem restrição de ano. A amostra foi composta por 27 artigos, os quais foram publicados entre 2011 e 2016, todos internacionais. As redes sociais utilizadas foram o Facebook (66,5%), o Twitter (30%) e o WhatsApp (3,5%). Em 70,5% dos estudos as redes sociais foram utilizadas para fins de pesquisa, em 18,5% como ferramenta para auxiliar estudantes nas atividades acadêmicas, e em 11% para a realização de intervenções via internet. Em seus processos de trabalho, os enfermeiros têm utilizado

  7. Is early cord clamping, delayed cord clamping or cord milking best?

    Science.gov (United States)

    Vatansever, Binay; Demirel, Gamze; Ciler Eren, Elif; Erel, Ozcan; Neselioglu, Salim; Karavar, Hande Nur; Gundogdu, Semra; Ulfer, Gozde; Bahadir, Selcen; Tastekin, Ayhan

    2018-04-01

    To compare the antioxidant status of three cord clamping procedures (early clamping, delayed clamping and milking) by analyzing the thiol-disulfide balance. This randomized controlled study enrolled 189 term infants who were divided into three groups according to the cord clamping procedure: early clamping, delayed clamping and milking. Blood samples were collected from the umbilical arteries immediately after clamping, and the thiol/disulfide homeostasis was analyzed. The native and total thiol levels were significantly (p cord clamping group compared with the other two groups. The disulfide/total thiol ratio was significantly (p = .026) lower in the delayed cord clamping and milking groups compared with the early clamping groups. Early cord clamping causes the production of more disulfide bonds and lower thiol levels, indicating that oxidation reactions are increased in the early cord clamping procedure compared with the delayed cord clamping and milking procedures. The oxidant capacity is greater with early cord clamping than with delayed clamping or cord milking. Delayed cord clamping or milking are beneficial in neonatal care, and we suggest that they be performed routinely in all deliveries.

  8. Microchip amplifier for in vitro, in vivo, and automated whole cell patch-clamp recording

    OpenAIRE

    Harrison, Reid R.; Kolb, Ilya; Kodandaramaiah, Suhasa B.; Chubykin, Alexander A.; Yang, Aimei; Bear, Mark F.; Boyden, Edward S.; Forest, Craig R.

    2014-01-01

    Patch clamping is a gold-standard electrophysiology technique that has the temporal resolution and signal-to-noise ratio capable of reporting single ion channel currents, as well as electrical activity of excitable single cells. Despite its usefulness and decades of development, the amplifiers required for patch clamping are expensive and bulky. This has limited the scalability and throughput of patch clamping for single-ion channel and single-cell analyses. In this work, we have developed a ...

  9. WORKING TOGETHER: EDUCATION, RESEARCH AND DEVELOPMENT FOR 5G NETWORKS

    Directory of Open Access Journals (Sweden)

    E. P. Ivanova

    2015-12-01

    Full Text Available In the new world of globalization of ideas and mobility difficulties in knowledge diffusion still remains. The effectiveexchange of experiences and skills in new generation networks is not guaranteed by the enormous potentialsofinternetworking systems and devices. Conceptual model for performance modeling and evaluation of multiservicenetworks has been major interest for mobile networks providers. It is essential to assess the performance ofmobile system architectures in order to identify where potential bottlenecks and data packet blocking probabilityare possible to occur. Educational platforms, new simulations opportunities represent a good opportunity to reducethe digital divide and to ensure faster and higher communication trends. Several universities and companies arecurrently involved in using educational platforms to provide better results. Conceptual model for teletrafficengineering in educational platform and applications focuses on some important aspects: tutorials, exercise,simulations, and expectation values of parameters, testing and estimation of students work. In the same time thesame model is very appropriate for simulation of network management for the new generation networks. Thiseducational platform for academics, students and researchers, puts together some of the critical aspects ofdistributed systems and their characteristics, parameters and probability of blocking.

  10. Neural Networks for Time Perception and Working Memory.

    Science.gov (United States)

    Üstün, Sertaç; Kale, Emre H; Çiçek, Metehan

    2017-01-01

    Time is an important concept which determines most human behaviors, however questions remain about how time is perceived and which areas of the brain are responsible for time perception. The aim of this study was to evaluate the relationship between time perception and working memory in healthy adults. Functional magnetic resonance imaging (fMRI) was used during the application of a visual paradigm. In all of the conditions, the participants were presented with a moving black rectangle on a gray screen. The rectangle was obstructed by a black bar for a time period and then reappeared again. During different conditions, participants ( n = 15, eight male) responded according to the instructions they were given, including details about time and the working memory or dual task requirements. The results showed activations in right dorsolateral prefrontal and right intraparietal cortical networks, together with the anterior cingulate cortex (ACC), anterior insula and basal ganglia (BG) during time perception. On the other hand, working memory engaged the left prefrontal cortex, ACC, left superior parietal cortex, BG and cerebellum activity. Both time perception and working memory were related to a strong peristriate cortical activity. On the other hand, the interaction of time and memory showed activity in the intraparietal sulcus (IPS) and posterior cingulate cortex (PCC). These results support a distributed neural network based model for time perception and that the intraparietal and posterior cingulate areas might play a role in the interface of memory and timing.

  11. Patterns of work attitudes: A neural network approach

    Science.gov (United States)

    Mengov, George D.; Zinovieva, Irina L.; Sotirov, George R.

    2000-05-01

    In this paper we introduce a neural networks based approach to analyzing empirical data and models from work and organizational psychology (WOP), and suggest possible implications for the practice of managers and business consultants. With this method it becomes possible to have quantitative answers to a bunch of questions like: What are the characteristics of an organization in terms of its employees' motivation? What distinct attitudes towards the work exist? Which pattern is most desirable from the standpoint of productivity and professional achievement? What will be the dynamics of behavior as quantified by our method, during an ongoing organizational change or consultancy intervention? Etc. Our investigation is founded on the theoretical achievements of Maslow (1954, 1970) in human motivation, and of Hackman & Oldham (1975, 1980) in job diagnostics, and applies the mathematical algorithm of the dARTMAP variation (Carpenter et al., 1998) of the Adaptive Resonance Theory (ART) neural networks introduced by Grossberg (1976). We exploit the ART capabilities to visualize the knowledge accumulated in the network's long-term memory in order to interpret the findings in organizational research.

  12. Solution structure of an "open" E. coli Pol III clamp loader sliding clamp complex.

    Science.gov (United States)

    Tondnevis, Farzaneh; Weiss, Thomas M; Matsui, Tsutomu; Bloom, Linda B; McKenna, Robert

    2016-06-01

    Sliding clamps are opened and loaded onto primer template junctions by clamp loaders, and once loaded on DNA, confer processivity to replicative polymerases. Previously determined crystal structures of eukaryotic and T4 clamp loader-clamp complexes have captured the sliding clamps in either closed or only partially open interface conformations. In these solution structure studies, we have captured for the first time the clamp loader-sliding clamp complex from Escherichia coli using size exclusion chromatography coupled to small angle X-ray scattering (SEC-SAXS). The data suggests the sliding clamp is in an open conformation which is wide enough to permit duplex DNA binding. The data also provides information about spatial arrangement of the sliding clamp with respect to the clamp loader subunits and is compared to complex crystal structures determined from other organisms. Published by Elsevier Inc.

  13. Whole-GUV patch-clamping.

    Science.gov (United States)

    Garten, Matthias; Mosgaard, Lars D; Bornschlögl, Thomas; Dieudonné, Stéphane; Bassereau, Patricia; Toombes, Gilman E S

    2017-01-10

    Studying how the membrane modulates ion channel and transporter activity is challenging because cells actively regulate membrane properties, whereas existing in vitro systems have limitations, such as residual solvent and unphysiologically high membrane tension. Cell-sized giant unilamellar vesicles (GUVs) would be ideal for in vitro electrophysiology, but efforts to measure the membrane current of intact GUVs have been unsuccessful. In this work, two challenges for obtaining the "whole-GUV" patch-clamp configuration were identified and resolved. First, unless the patch pipette and GUV pressures are precisely matched in the GUV-attached configuration, breaking the patch membrane also ruptures the GUV. Second, GUVs shrink irreversibly because the membrane/glass adhesion creating the high-resistance seal (>1 GΩ) continuously pulls membrane into the pipette. In contrast, for cell-derived giant plasma membrane vesicles (GPMVs), breaking the patch membrane allows the GPMV contents to passivate the pipette surface, thereby dynamically blocking membrane spreading in the whole-GMPV mode. To mimic this dynamic passivation mechanism, beta-casein was encapsulated into GUVs, yielding a stable, high-resistance, whole-GUV configuration for a range of membrane compositions. Specific membrane capacitance measurements confirmed that the membranes were truly solvent-free and that membrane tension could be controlled over a physiological range. Finally, the potential for ion transport studies was tested using the model ion channel, gramicidin, and voltage-clamp fluorometry measurements were performed with a voltage-dependent fluorophore/quencher pair. Whole-GUV patch-clamping allows ion transport and other voltage-dependent processes to be studied while controlling membrane composition, tension, and shape.

  14. Coactivation of the Default Mode Network regions and Working Memory Network regions during task preparation.

    Science.gov (United States)

    Koshino, Hideya; Minamoto, Takehiro; Yaoi, Ken; Osaka, Mariko; Osaka, Naoyuki

    2014-08-05

    The Default Mode Network (DMN) regions exhibit deactivation during a wide variety of resource demanding tasks. However, recent brain imaging studies reported that they also show activation during various cognitive activities. In addition, studies have found a negative correlation between the DMN and the working memory network (WMN). Here, we investigated activity in the DMN and WMN regions during preparation and execution phases of a verbal working memory task. Results showed that the core DMN regions, including the medial prefrontal cortex and posterior cingulate cortex, and WMN regions were activated during preparation. During execution, however, the WMN regions were activated but the DMN regions were deactivated. The results suggest that activation of these network regions is affected by allocation of attentional resources to the task relevant regions due to task demands. This study extends our previous results by showing that the core DMN regions exhibit activation during task preparation and deactivation during task execution.

  15. Loading dynamics of a sliding DNA clamp.

    KAUST Repository

    Cho, Won-Ki

    2014-05-22

    Sliding DNA clamps are loaded at a ss/dsDNA junction by a clamp loader that depends on ATP binding for clamp opening. Sequential ATP hydrolysis results in closure of the clamp so that it completely encircles and diffuses on dsDNA. We followed events during loading of an E. coli β clamp in real time by using single-molecule FRET (smFRET). Three successive FRET states were retained for 0.3 s, 0.7 s, and 9 min: Hydrolysis of the first ATP molecule by the γ clamp loader resulted in closure of the clamp in 0.3 s, and after 0.7 s in the closed conformation, the clamp was released to diffuse on the dsDNA for at least 9 min. An additional single-molecule polarization study revealed that the interfacial domain of the clamp rotated in plane by approximately 8° during clamp closure. The single-molecule polarization and FRET studies thus revealed the real-time dynamics of the ATP-hydrolysis-dependent 3D conformational change of the β clamp during loading at a ss/dsDNA junction.

  16. Dynamics of Open DNA Sliding Clamps.

    Directory of Open Access Journals (Sweden)

    Aaron J Oakley

    Full Text Available A range of enzymes in DNA replication and repair bind to DNA-clamps: torus-shaped proteins that encircle double-stranded DNA and act as mobile tethers. Clamps from viruses (such as gp45 from the T4 bacteriophage and eukaryotes (PCNAs are homotrimers, each protomer containing two repeats of the DNA-clamp motif, while bacterial clamps (pol III β are homodimers, each protomer containing three DNA-clamp motifs. Clamps need to be flexible enough to allow opening and loading onto primed DNA by clamp loader complexes. Equilibrium and steered molecular dynamics simulations have been used to study DNA-clamp conformation in open and closed forms. The E. coli and PCNA clamps appear to prefer closed, planar conformations. Remarkably, gp45 appears to prefer an open right-handed spiral conformation in solution, in agreement with previously reported biophysical data. The structural preferences of DNA clamps in solution have implications for understanding the duty cycle of clamp-loaders.

  17. The RFC Clamp Loader: Structure and Function

    Science.gov (United States)

    O'Donnell, Mike

    2013-01-01

    The eukaryotic RFC clamp loader couples the energy of ATP hydrolysis to open and close the circular PCNA sliding clamp onto primed sites for use by DNA polymerases and repair factors. Structural studies reveal clamp loaders to be heteropentamers. Each subunit contains a region of homology to AAA+ proteins that defines two domains. The AAA+ domains form a right-handed spiral upon binding ATP. This spiral arrangement generates a DNA binding site within the center of RFC. DNA enters the central chamber through a gap between the AAA+ domains of two subunits. Specificity for a primed template junction is achieved by a third domain that blocks DNA, forcing it to bend sharply. Thus only DNA with a flexible joint can bind the central chamber. DNA entry also requires a slot in the PCNA clamp, which is opened upon binding the AAA+ domains of the clamp loader. ATP hydrolysis enables clamp closing and ejection of RFC, completing the clamp loading reaction. PMID:22918590

  18. Dynamic Vehicle Scheduling for Working Service Network with Dual Demands

    Directory of Open Access Journals (Sweden)

    Bing Li

    2017-01-01

    Full Text Available This study aims to develop some models to aid in making decisions on the combined fleet size and vehicle assignment in working service network where the demands include two types (minimum demands and maximum demands, and vehicles themselves can act like a facility to provide services when they are stationary at one location. This type of problem is named as the dynamic working vehicle scheduling with dual demands (DWVS-DD and formulated as a mixed integer programming (MIP. Instead of a large integer program, the problem is decomposed into small local problems that are guided by preset control parameters. The approach for preset control parameters is given. By introducing them into the MIP formulation, the model is reformulated as a piecewise form. Further, a piecewise method by updating preset control parameters is proposed for solving the reformulated model. Numerical experiments show that the proposed method produces better solution within reasonable computing time.

  19. The Impact of a Power Electronics Converter in Phase Failure Work on the Power System Network

    Directory of Open Access Journals (Sweden)

    Dariusz Zieliński

    2016-09-01

    Full Text Available The paper presents the impact of phase failure work on power converters. The study includes a three-level NPC inverter (Neutral Point Clamped, controlled by Voltage Oriented Control (VOC. The NPC converter integrates renewable energy sources with the power grid. The article includes a discussion about the causes of phase failure work and an analysis of the converter’s failure and its impact on the power grid. The simulations were performed in MATLAB/Simulink. The study also includes the concept of an integrated protection for IGBTs, controlled by the DSP microprocessor system.

  20. Neural network controller for underwater work ROV. Suichu sagyoyo ROV no neural network controller

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Y.; Kidoshi, H.; Arahata, M.; Shoji, K.; Takahashi, Y. (Ishikawajima-Harima Heavy Industries, Co. Ltd., Tokyo (Japan))

    1993-07-01

    The previous underwater work ROV (remotely operated vehicle) has been controlled manually because its dynamic properties are changeable underwater. Ishikawajima-Harima Heavy Industries (IHI) has applied a neural network to an adaptive controller for the ROV. This paper describes objectives of the research, design of control logic, and tank experiments on a model ROV. For the neural network, manual operation was used to provide the initial learning data for the neural network in order to initialize control parameters for optimization. The model ROV was designed to achieve and maintain constant depth in normal operation. As a consequence of the tank experiments, it was demonstrated that the controller can acquire skill of operators, can further improve the acquired skill of operators, and can construct an automatic control system autonomically even if any dynamic properties are not known. 6 refs., 8 figs.

  1. State of the (net)work address Developing criteria for applying social networking to the work environment.

    Science.gov (United States)

    Valdez, André Calero; Schaar, Anne Kathrin; Ziefle, Martina

    2012-01-01

    In an increasingly faster paced innovative world, maintaining the ability to innovate in spite of an aging work force will become every company's strongest leverage for success. Tapping the latent knowledge resources and creativity of overlooked employees and persisting crucial information for business conduct are promising results for social networking sites (SNS) in a working context. Usability and usefulness are exponential factors in creating a successful SNS. In order to make a SNS usable for a heterogeneous user group, analyses of user diversity in regard to social media need to be done. Furthermore differences in communication medium and frequency in regard to age, content, hierarchy position, departmental thresholds and company size need to be analyzed. For analysis purposes both qualitative and quantitative research methods were applied. Strong effects of age and communication content were found in survey with 194 participants.

  2. Microchip amplifier for in vitro, in vivo, and automated whole cell patch-clamp recording.

    Science.gov (United States)

    Harrison, Reid R; Kolb, Ilya; Kodandaramaiah, Suhasa B; Chubykin, Alexander A; Yang, Aimei; Bear, Mark F; Boyden, Edward S; Forest, Craig R

    2015-02-15

    Patch clamping is a gold-standard electrophysiology technique that has the temporal resolution and signal-to-noise ratio capable of reporting single ion channel currents, as well as electrical activity of excitable single cells. Despite its usefulness and decades of development, the amplifiers required for patch clamping are expensive and bulky. This has limited the scalability and throughput of patch clamping for single-ion channel and single-cell analyses. In this work, we have developed a custom patch-clamp amplifier microchip that can be fabricated using standard commercial silicon processes capable of performing both voltage- and current-clamp measurements. A key innovation is the use of nonlinear feedback elements in the voltage-clamp amplifier circuit to convert measured currents into logarithmically encoded voltages, thereby eliminating the need for large high-valued resistors, a factor that has limited previous attempts at integration. Benchtop characterization of the chip shows low levels of current noise [1.1 pA root mean square (rms) over 5 kHz] during voltage-clamp measurements and low levels of voltage noise (8.2 μV rms over 10 kHz) during current-clamp measurements. We demonstrate the ability of the chip to perform both current- and voltage-clamp measurement in vitro in HEK293FT cells and cultured neurons. We also demonstrate its ability to perform in vivo recordings as part of a robotic patch-clamping system. The performance of the patch-clamp amplifier microchip compares favorably with much larger commercial instrumentation, enabling benchtop commoditization, miniaturization, and scalable patch-clamp instrumentation. Copyright © 2015 the American Physiological Society.

  3. Microchip amplifier for in vitro, in vivo, and automated whole cell patch-clamp recording

    Science.gov (United States)

    Kolb, Ilya; Kodandaramaiah, Suhasa B.; Chubykin, Alexander A.; Yang, Aimei; Bear, Mark F.; Boyden, Edward S.; Forest, Craig R.

    2014-01-01

    Patch clamping is a gold-standard electrophysiology technique that has the temporal resolution and signal-to-noise ratio capable of reporting single ion channel currents, as well as electrical activity of excitable single cells. Despite its usefulness and decades of development, the amplifiers required for patch clamping are expensive and bulky. This has limited the scalability and throughput of patch clamping for single-ion channel and single-cell analyses. In this work, we have developed a custom patch-clamp amplifier microchip that can be fabricated using standard commercial silicon processes capable of performing both voltage- and current-clamp measurements. A key innovation is the use of nonlinear feedback elements in the voltage-clamp amplifier circuit to convert measured currents into logarithmically encoded voltages, thereby eliminating the need for large high-valued resistors, a factor that has limited previous attempts at integration. Benchtop characterization of the chip shows low levels of current noise [1.1 pA root mean square (rms) over 5 kHz] during voltage-clamp measurements and low levels of voltage noise (8.2 μV rms over 10 kHz) during current-clamp measurements. We demonstrate the ability of the chip to perform both current- and voltage-clamp measurement in vitro in HEK293FT cells and cultured neurons. We also demonstrate its ability to perform in vivo recordings as part of a robotic patch-clamping system. The performance of the patch-clamp amplifier microchip compares favorably with much larger commercial instrumentation, enabling benchtop commoditization, miniaturization, and scalable patch-clamp instrumentation. PMID:25429119

  4. Arterial clamping leads to stenosis at clamp sites after femoropopliteal bypass surgery.

    Science.gov (United States)

    Vriens, Bianca H R; Pol, Robert A; Hulsebos, Robin G; van Det, Rob J; van der Palen, Job; Zeebregts, Clark J; Geelkerken, Robert H

    2015-09-01

    To date, the incidence and clinical relevance of arterial stenosis at clamp sites after femoropopliteal bypass surgery is unknown. Ninety-four patients underwent a femoropopliteal bypass in which the arterial inflow and outflow clamp sites were controlled by the Fogarty-Soft-Inlay clamp and marked with an hemoclip. The number of pre-existing atherosclerotic segments, clamp force, and clamp time were recorded and the occurrence of a stenosis at the clamp site was determined. After a mean follow-up of 83 months, a significant stenosis was confirmed at 23 of the 178 clamp sites (12.9%; 95% confidence interval 8.4 to 18.8). The mean number of pre-existing atherosclerotic segments (P = .28) and the mean clamp force (P = .55) was similar between the groups with and without a stenosis. There was a significant difference regarding clamp time between the group with and without a stenosis (38 minutes and 26 minutes, P = .001). Arterial clamping, even with the Fogarty-Soft-Inlay clamp, can lead to clamp stenosis and seems to be related to the duration of clamping, but not to pre-existent atherosclerotic burden. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. To clamp or not to clamp? Long-term functional outcomes for elective off-clamp laparoscopic partial nephrectomy.

    Science.gov (United States)

    Shah, Paras H; George, Arvin K; Moreira, Daniel M; Alom, Manaf; Okhunov, Zhamshid; Salami, Simpa; Waingankar, Nikhil; Schwartz, Michael J; Vira, Manish A; Richstone, Lee; Kavoussi, Louis R

    2016-02-01

    To evaluate whether elective off-clamp laparoscopic partial nephrectomy (LPN) affords long-term renal functional benefit compared with the on-clamp approach. This is a retrospective review of patients who underwent elective LPN between 2006 and 2011. Patients were followed longitudinally for up to 5 years. In all, 315 patients with radiographic evidence of a solitary renal mass and normal-appearing contralateral kidney underwent elective LPN; 209 were performed on-clamp vs 106 off-clamp. One patient who required conversion from LPN to open PN was excluded from the study. Additionally, four patients in the on-clamp cohort who underwent subsequent radical nephrectomy for local-regional recurrence were excluded from longitudinal functional evaluation after their procedure. The primary objective was to evaluate differences in postoperative estimated glomerular filtration rate (eGFR) between hilar clamping groups. Subgroup analyses were performed for patients with clamp times >30 min and those with baseline renal insufficiency (eGFR clamp and off-clamp cohorts (80.7 vs 84.1 mL/min/1.73m(2) , P > 0.05). Univariable and multivariable analyses did not show significant differences in postoperative eGFR between both groups among all-comers, those with clamp times >30 min, and patients with baseline renal insufficiency. Risk of chronic kidney disease was not diminished by the off-clamp approach with up to 5 years of follow-up. Progressive recovery of renal function after hilar clamping in the elective setting eclipses short-term functional benefit achieved with off-clamp LPN by 6 months; there was no significant difference in eGFR or the percentage incidence of chronic kidney disease between the on-clamp and off-clamp cohorts with up to 5 years follow-up. As such, eliminating transient ischaemia during elective LPN does not confer clinical benefit. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

  6. Sub-nanometer stable precision MEMS clamping mechanism maintaining clamp force unpowered for TEM application

    NARCIS (Netherlands)

    Brouwer, Dannis Michel; de Jong, B.R.; Soemers, Herman; van Dijk, Johannes

    2006-01-01

    A design is presented for a relatively large force (0.5 mN) high-precision MEMS clamping mechanism. The clamp is a part of a MEMS transmission electron microscope (TEM) sample manipulator, which needs to be fixed unpowered once positioned. The elastic deformation of the clamp suspension has been

  7. Electrostatic clamp manufactured by novel method

    NARCIS (Netherlands)

    Sligte, E. te; Storm, A.; Koster, N.B.

    2011-01-01

    Electrostatic clamps (ESCs), used in reticle and wafer handling, are presently manufactured using glass bonding and polishing technologies. We present a patented alternative concept to this process, relying on coating and etching processes rather than bonding. We manufactured a first prototype clamp

  8. Clamp and grout systems for structural repair

    Energy Technology Data Exchange (ETDEWEB)

    Lalani, M.

    1984-10-01

    Steel offshore platforms in the North Sea and elsewhere have required repair or strengthening, opening up a new and important aspect of offshore engineering. A clamp and grout system for structured repair is described. Over 150 clamped and grouted repair systems are now in service in the North Sea and elsewhere.

  9. Work of Adhesion Measurements of Silicone Networks Using Contract Mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Benkoski, J.; Emerson, J.A.; Miller, G.V.; Pearson, R.A.

    1999-04-21

    Work of adhesion (Wa) measurements are being studied for several types of polymer/metal combinations in order to obtain a better understanding of the adhesive failure mechanisms for systems containing encapsulated and bonded components. A primary concern is whether studies of model systems can be extended to systems of technological interest. One study performed in our laboratory involved the determination of Wa between silicone (PDMS) and Al surfaces in order to establish potential adhesive failure mechanisms. Our initial work with PDMS was based on Dow Corning 170 Sylgard. PDMS hemispheres were synthesized following the procedure outlined by Chaudhury and Whitesides where the filler was stripped from the commercial silicone by centrifuging. Wa between PDMS surfaces was determined using the JKR method. Our results for the Wa of PDMS were in agreement with those reported by Chaudhury and Whitesides. However, further JKR studies using these PDMS hemispheres on flat Al surfaces were fraught with difficulty. We could not discriminate hydrogen-bonding effects between Al{sub 2}O{sub 3} and hydroxyl groups in the PDMS and other possible bonding mechanisms. It was suggested that commercial systems contain inhibitors and additives that interfere with understanding the PMDS/Al interface. Therefore, the current study uses pure PDMS networks synthesized in our lab. Also, two contact mechanics methods were deployed to measure the Wa--JKR method using two hemispheres and a LEFM method using a cylinder containing a circumferential crack. This paper contains a description of the synthesis of the PDMS used for these studies and the determination of Wa between PDMS surfaces using the JKR method, contact angle measurements, and a LEFM method that consists of a cylinder containing a circumferential crack.

  10. Is functional integration of resting state brain networks an unspecific biomarker for working memory performance?

    Science.gov (United States)

    Alavash, Mohsen; Doebler, Philipp; Holling, Heinz; Thiel, Christiane M; Gießing, Carsten

    2015-03-01

    Is there one optimal topology of functional brain networks at rest from which our cognitive performance would profit? Previous studies suggest that functional integration of resting state brain networks is an important biomarker for cognitive performance. However, it is still unknown whether higher network integration is an unspecific predictor for good cognitive performance or, alternatively, whether specific network organization during rest predicts only specific cognitive abilities. Here, we investigated the relationship between network integration at rest and cognitive performance using two tasks that measured different aspects of working memory; one task assessed visual-spatial and the other numerical working memory. Network clustering, modularity and efficiency were computed to capture network integration on different levels of network organization, and to statistically compare their correlations with the performance in each working memory test. The results revealed that each working memory aspect profits from a different resting state topology, and the tests showed significantly different correlations with each of the measures of network integration. While higher global network integration and modularity predicted significantly better performance in visual-spatial working memory, both measures showed no significant correlation with numerical working memory performance. In contrast, numerical working memory was superior in subjects with highly clustered brain networks, predominantly in the intraparietal sulcus, a core brain region of the working memory network. Our findings suggest that a specific balance between local and global functional integration of resting state brain networks facilitates special aspects of cognitive performance. In the context of working memory, while visual-spatial performance is facilitated by globally integrated functional resting state brain networks, numerical working memory profits from increased capacities for local processing

  11. The Network of International Student Mobility (Working Title)

    Energy Technology Data Exchange (ETDEWEB)

    Voegtle, E.; Windzio, M.

    2016-07-01

    In a previous paper (see Vögtle and Windzio 2016) we investigated the impact of membership in the Bologna Process on patterns and driving forces of cross-national student mobility. Student exchange flows were analysed for almost all Bologna Process member states and nonBologna OECD members over a ten-year period (from 2000 to 2009). We applied a Social Network Approach focusing on outbound diploma-mobility to identify positions of countries in the network of cross-national student exchange. Based on social network analyses, we first visualized the exchange patterns between sampled countries. In doing so, we analysed the student exchange linkages to gain descriptive insights into the development of the network (see Figure 1). Second, we used Exponential Random Graph Models (ERGM) to test which factors determine patterns of transnational student mobility. The results of this network analyses reveal that cross-national student exchange networks are stable over time. At the core of these networks are the United States, Great Britain, France, and Germany; they attract the highest shares of students from the remaining countries in our sample. Moreover, the results of the ERGM demonstrate that homophily between countries determines student exchange patterns. The most relevant ties exist between bordering countries. Moreover, membership in the Bologna Process impacts on mobility patterns, and the effect size increases over the periods investigated. (Author)

  12. A direct proofreader-clamp interaction stabilizes the Pol III replicase in the polymerization mode

    KAUST Repository

    Jergic, Slobodan

    2013-02-22

    Processive DNA synthesis by the αÉ"θ core of the Escherichia coli Pol III replicase requires it to be bound to the β 2 clamp via a site in the α polymerase subunit. How the É" proofreading exonuclease subunit influences DNA synthesis by α was not previously understood. In this work, bulk assays of DNA replication were used to uncover a non-proofreading activity of É". Combination of mutagenesis with biophysical studies and single-molecule leading-strand replication assays traced this activity to a novel β-binding site in É" that, in conjunction with the site in α, maintains a closed state of the αÉ"θ-β 2 replicase in the polymerization mode of DNA synthesis. The É"-β interaction, selected during evolution to be weak and thus suited for transient disruption to enable access of alternate polymerases and other clamp binding proteins, therefore makes an important contribution to the network of protein-protein interactions that finely tune stability of the replicase on the DNA template in its various conformational states. © 2013 European Molecular Biology Organization.

  13. Knowledge sharing and work performance: a network perspective

    National Research Council Canada - National Science Library

    Wu, Wei-Li; Yeh, Ryh-Song; Hung, Hao-Kai

    2012-01-01

    .... Participants were 170 employees from 4 companies in Taiwan, and it was found that in-degree and in-closeness centralities within a knowledge-sharing network had significant and positive effects...

  14. Clamp force and alignment checking device

    Science.gov (United States)

    Spicer, John Patrick; Cai, Wayne W.; Chakraborty, Debejyo; Mink, Keith

    2017-04-11

    A check fixture measures a total clamp force applied by a welder device. The welder device includes a welding horn having a plurality of weld pads and welding anvil having a plurality of weld pads. The check fixture includes a base member operatively supporting a plurality of force sensors. The base member and the force sensors are received between the weld pads of the welding horn and the anvil pads of the welding anvil. Each force sensor is configured to measure an individual clamp force applied thereto by corresponding weld and anvil pads when the base member is received between the welding horn and the welding anvil and the welder device is in the clamped position. The individual clamp forces are used to determine whether the weld and/or anvil pads are worn or misaligned.

  15. THE USE OF ELECTRONIC SOCIAL NETWORKS IN SOCIAL AND EDUCATIONAL WORK WITH PUPILS

    OpenAIRE

    Natalia V. Oleksiuk; Lesya V. Lebedenko

    2015-01-01

    Electronic social networks are powerful means of communication for million registered users, because some social groups are gaining considerable popularity among pupils of secondary schools. The author believes that the use of electronic social networks is actual not just for training purposes, but also to implement the social and educational work in the school environment. In publication there have been reviewed electronic social networks, including business networks, comparison of their pro...

  16. Intensive Working Memory Training Produces Functional Changes in Large-scale Frontoparietal Networks.

    Science.gov (United States)

    Thompson, Todd W; Waskom, Michael L; Gabrieli, John D E

    2016-04-01

    Working memory is central to human cognition, and intensive cognitive training has been shown to expand working memory capacity in a given domain. It remains unknown, however, how the neural systems that support working memory are altered through intensive training to enable the expansion of working memory capacity. We used fMRI to measure plasticity in activations associated with complex working memory before and after 20 days of training. Healthy young adults were randomly assigned to train on either a dual n-back working memory task or a demanding visuospatial attention task. Training resulted in substantial and task-specific expansion of dual n-back abilities accompanied by changes in the relationship between working memory load and activation. Training differentially affected activations in two large-scale frontoparietal networks thought to underlie working memory: the executive control network and the dorsal attention network. Activations in both networks linearly scaled with working memory load before training, but training dissociated the role of the two networks and eliminated this relationship in the executive control network. Load-dependent functional connectivity both within and between these two networks increased following training, and the magnitudes of increased connectivity were positively correlated with improvements in task performance. These results provide insight into the adaptive neural systems that underlie large gains in working memory capacity through training.

  17. Use of the Satinsky clamp for hilar clamping during robotic partial nephrectomy: indications, technique, and multi-center outcomes.

    Science.gov (United States)

    Abdullah, Newaj; Rahbar, Haider; Barod, Ravi; Dalela, Deepansh; Larson, Jeff; Johnson, Michael; Mass, Alon; Zargar, Homayoun; Kaouk, Jihad; Allaf, Mohamad; Bhayani, Sam; Stifelman, Michael; Rogers, Craig

    2017-03-01

    A Satinsky clamp may be a backup option for hilar clamping during robotic partial nephrectomy (RPN) if there are challenges with application of bulldog clamps, but there are potential safety concerns. We evaluate outcomes of RPN using Satinsky vs. bulldog clamps, and provide tips for safe use of the Satinsky as a backup option. Using a multi-center database, we identified 1073 patients who underwent RPN between 2006 and 2013, and had information available about method of hilar clamping (bulldog clamp vs. Satinsky clamp). Patient baseline characteristics, tumor features, and perioperative outcomes were compared between the Satinsky and bulldog clamp groups. A Satinsky clamp was used for hilar clamping in 94 (8.8 %) RPN cases, and bulldog clamps were used in 979 (91.2 %) cases. The use of a Satinsky clamp was associated with greater operative time (198 vs. 175 min, p clamp group, but none were directly related to the Satinsky clamp. On multivariable analysis, the use of the Satinsky clamp was not associated with increase in intraoperative or Clavien ≥3 postoperative complications, positive surgical margin rate or percentage change in estimated glomerular filtration rate. A Satinsky clamp can be a backup option for hilar clamping during challenging RPN cases, but requires careful technique, and was rarely necessary.

  18. A High-Efficiency Diode-Clamped Linear Amplifier

    Science.gov (United States)

    Fujita, Hideaki

    This paper proposes a new power converter without any switching operation, which works as a linear amplifier. The main circuit of the proposed converter consists of series-connected MOSFETs, series-multi dc power supplies and clamping diodes. The circuit configuration is similar to a diode-clamped multi-level inverter, except for using complementary power devices, which are n- and p-channel MOSFETs. One of the series-connected MOSFETs operates in an active state just like a linear amplifier, while the other MOSFETs operate in on or off states like an inverter circuit. As a result, the proposed converter achieves an acceptable efficiency as high as 90% without any ripples nor harmonics caused by switching operation. Experimental results demonstrate that the proposed converter has capability of driving a 2.2-kW three-phase induction motor.

  19. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures. (b...

  20. Knowledge work and communication challenges in networked enterprises

    NARCIS (Netherlands)

    Barjis, J.; Gupta, A.; Sharda, R.

    2010-01-01

    A modern enterprise is a heavily wired and networked socio-technical system where multiple components play in symphony to yield a competitive position in the ear of digital economy. While the underling communication and interaction systems facilitate knowledge workers to carry out the enterprise

  1. Assigning the Appropriate Works for Review on Networked Peer Assessment

    Science.gov (United States)

    Lee, Chien-I

    2017-01-01

    Peer assessment can expand the cognitive schemas of students, facilitate knowledge construction, and promote discussion and cooperative learning among students and their peers. In recent years, the application of the internet to conduct peer assessment activities has been widely implemented. The advantages of networked peer assessments over…

  2. Computer-mediated-communication and social networking tools at work

    NARCIS (Netherlands)

    Ou, C.X.J.; Sia, C.L.; Hui, C.K.

    2013-01-01

    Purpose – Advances in information technology (IT) have resulted in the development of various computer‐mediated communication (CMC) and social networking tools. However, quantifying the benefits of utilizing these tools in the organizational context remains a challenge. In this study, the authors

  3. Arterial clamping leads to stenosis at clamp sites after femoropopliteal bypass surgery

    NARCIS (Netherlands)

    Vriens, Bianca H. R.; Pol, Robert A.; Hulsebos, Robin G.; van Det, Rob J.; van der Palen, Job; Zeebregts, Clark J.; Geelkerken, Robert H.

    BACKGROUND: To date, the incidence and clinical relevance of arterial stenosis at clamp sites after femoropopliteal bypass surgery is unknown. METHODS: Ninety-four patients underwent a femoropopliteal bypass in which the arterial inflow and outflow clamp sites were controlled by the

  4. Arterial clamping leads to stenosis at clamp sites after femoropopliteal bypass surgery

    NARCIS (Netherlands)

    Vriens, Bianca H.R.; Pol, Robert A.; Hulsebos, Robin G.; van Det, Rob J.; van der Palen, Jacobus Adrianus Maria; Zeebregts, Clark J.; Geelkerken, Robert H.

    2015-01-01

    Background To date, the incidence and clinical relevance of arterial stenosis at clamp sites after femoropopliteal bypass surgery is unknown. Methods Ninety-four patients underwent a femoropopliteal bypass in which the arterial inflow and outflow clamp sites were controlled by the Fogarty-Soft-Inlay

  5. Shared Leadership In Work Teams: A Social Network Approach

    OpenAIRE

    JUAN CARLOS PASTOR; MARGARITA MAYO

    2002-01-01

    (WP10/02 Clave pdf) In the past few years, the concept of leadership has shifted from the solitary leader to the team as a potential source of leadership. This shift from a single person to a "shared leadership" model requires new concepts and methods to capture the nature and structure of leadership by teams (Yukl, 1998). In this chapter, we argue that a social network approach helps to provide the conceptual framework and methodological tools to support a shared leadership perspective.

  6. Piezoresistive cantilever force-clamp system

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung-Jin; Petzold, Bryan C.; Pruitt, Beth L. [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Goodman, Miriam B. [Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305 (United States)

    2011-04-15

    We present a microelectromechanical device-based tool, namely, a force-clamp system that sets or ''clamps'' the scaled force and can apply designed loading profiles (e.g., constant, sinusoidal) of a desired magnitude. The system implements a piezoresistive cantilever as a force sensor and the built-in capacitive sensor of a piezoelectric actuator as a displacement sensor, such that sample indentation depth can be directly calculated from the force and displacement signals. A programmable real-time controller operating at 100 kHz feedback calculates the driving voltage of the actuator. The system has two distinct modes: a force-clamp mode that controls the force applied to a sample and a displacement-clamp mode that controls the moving distance of the actuator. We demonstrate that the system has a large dynamic range (sub-nN up to tens of {mu}N force and nm up to tens of {mu}m displacement) in both air and water, and excellent dynamic response (fast response time, <2 ms and large bandwidth, 1 Hz up to 1 kHz). In addition, the system has been specifically designed to be integrated with other instruments such as a microscope with patch-clamp electronics. We demonstrate the capabilities of the system by using it to calibrate the stiffness and sensitivity of an electrostatic actuator and to measure the mechanics of a living, freely moving Caenorhabditis elegans nematode.

  7. Whole-cell voltage clamp on skeletal muscle fibers with the silicone-clamp technique.

    Science.gov (United States)

    Lefebvre, Romain; Pouvreau, Sandrine; Collet, Claude; Allard, Bruno; Jacquemond, Vincent

    2014-01-01

    Control of membrane voltage and membrane current measurements are of critical importance for the study of numerous aspects of skeletal muscle physiology and pathophysiology. The silicone-clamp technique makes use of a conventional patch-clamp apparatus to achieve whole-cell voltage clamp of a restricted portion of a fully differentiated adult skeletal muscle fiber. The major part of an isolated muscle fiber is insulated from the extracellular medium with silicone grease and the tip of a single microelectrode connected to the amplifier is then inserted within the fiber through the silicone layer. The method is extremely easy to implement. It represents an alternative to the traditional vaseline-gap isolation and two or three microelectrodes voltage-clamp techniques. The present chapter reviews the benefits of the silicone-clamp technique and provides updated detailed insights into its practical implementation.

  8. IMPORTANT: Fluke is recalling Digital Clamp Meters

    CERN Multimedia

    2013-01-01

    Fluke is voluntarily recalling four models of Digital Clamp Meters: Fluke 373, 374, 375 and 376. If you own one of these clamp meters, please stop using it and send it back to Fluke for repair even if you have not experienced problems.   Description of the problem: "The printed circuit assembly may not be properly fastened to the test lead input jack. This may result in inaccurate voltage readings, including a low or no-voltage reading on a circuit energised with a hazardous voltage, presenting a shock, electrocution or thermal burn hazard." To determine if your clamp meter is affected by this recall notice, and for more information, click here.

  9. The pluripotency transcription factor network at work in reprogramming.

    Science.gov (United States)

    Niwa, Hitoshi

    2014-10-01

    Pluripotency-associated transcription factors possess a pivotal role to maintain pluripotency in pluripotent stem cells as well as to induce pluripotency in somatic cells. They direct specific pattern of gene expression from the genome by co-operating with the genetic and epigenetic mechanisms. Recent findings revealed that these mechanisms possess unique features in pluripotent stem cells, which is different from that in somatic cells either qualitatively and quantitatively. To reprogram somatic cells, pluripotency-associated transcription factors should modulate the co-operating machineries to establish the optimal environment for their function to maintain pluripotency-associated transcription factor network. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Functional Brain Network Modularity Captures Inter- and Intra-Individual Variation in Working Memory Capacity

    Science.gov (United States)

    Stevens, Alexander A.; Tappon, Sarah C.; Garg, Arun; Fair, Damien A.

    2012-01-01

    Background Cognitive abilities, such as working memory, differ among people; however, individuals also vary in their own day-to-day cognitive performance. One potential source of cognitive variability may be fluctuations in the functional organization of neural systems. The degree to which the organization of these functional networks is optimized may relate to the effective cognitive functioning of the individual. Here we specifically examine how changes in the organization of large-scale networks measured via resting state functional connectivity MRI and graph theory track changes in working memory capacity. Methodology/Principal Findings Twenty-two participants performed a test of working memory capacity and then underwent resting-state fMRI. Seventeen subjects repeated the protocol three weeks later. We applied graph theoretic techniques to measure network organization on 34 brain regions of interest (ROI). Network modularity, which measures the level of integration and segregation across sub-networks, and small-worldness, which measures global network connection efficiency, both predicted individual differences in memory capacity; however, only modularity predicted intra-individual variation across the two sessions. Partial correlations controlling for the component of working memory that was stable across sessions revealed that modularity was almost entirely associated with the variability of working memory at each session. Analyses of specific sub-networks and individual circuits were unable to consistently account for working memory capacity variability. Conclusions/Significance The results suggest that the intrinsic functional organization of an a priori defined cognitive control network measured at rest provides substantial information about actual cognitive performance. The association of network modularity to the variability in an individual's working memory capacity suggests that the organization of this network into high connectivity within modules

  11. Functional brain network modularity captures inter- and intra-individual variation in working memory capacity.

    Directory of Open Access Journals (Sweden)

    Alexander A Stevens

    Full Text Available Cognitive abilities, such as working memory, differ among people; however, individuals also vary in their own day-to-day cognitive performance. One potential source of cognitive variability may be fluctuations in the functional organization of neural systems. The degree to which the organization of these functional networks is optimized may relate to the effective cognitive functioning of the individual. Here we specifically examine how changes in the organization of large-scale networks measured via resting state functional connectivity MRI and graph theory track changes in working memory capacity.Twenty-two participants performed a test of working memory capacity and then underwent resting-state fMRI. Seventeen subjects repeated the protocol three weeks later. We applied graph theoretic techniques to measure network organization on 34 brain regions of interest (ROI. Network modularity, which measures the level of integration and segregation across sub-networks, and small-worldness, which measures global network connection efficiency, both predicted individual differences in memory capacity; however, only modularity predicted intra-individual variation across the two sessions. Partial correlations controlling for the component of working memory that was stable across sessions revealed that modularity was almost entirely associated with the variability of working memory at each session. Analyses of specific sub-networks and individual circuits were unable to consistently account for working memory capacity variability.The results suggest that the intrinsic functional organization of an a priori defined cognitive control network measured at rest provides substantial information about actual cognitive performance. The association of network modularity to the variability in an individual's working memory capacity suggests that the organization of this network into high connectivity within modules and sparse connections between modules may reflect

  12. Network evaluation: principles, structures and outcomes of the German working group of Health Promoting Universities.

    Science.gov (United States)

    Stock, Christiane; Milz, Simone; Meier, Sabine

    2010-03-01

    With more than 60 participating universities, the German working group of Health Promoting Universities (German HPU network) is the largest and most active network of universities as healthy settings. This study aims at evaluating processes and effects of the German HPU network and at supporting the future development of the network. The evaluation was based on the multi faceted network assessment instrument developed by Broesskamp-Stone (7). We used a document analysis, two expert interviews and a survey among members (n = 33) to collect relevant data for the assessment. The analysis showed that the visions of the network can be regarded as fulfilled in most aspects. The members of the network received network support through trustful and mutual relationships. The network ranked high on general network principles like implementation of mutual relationships, sharing of information, risks and resources, equal access to resources, responsibility and consensus orientation. However, a high degree of centralization was found as a negative indicator. Other critical aspects of the network's structures and processes have been the regional predominance of universities from the northern and middle part of Germany, the low representation of students in the network, and the low proportion of members that could successfully implement health promotion into the guiding principles of their university. Overall, the evaluation has shown that the network has worked effectively, has developed meaningful processes and structures and has formulated practical guidelines. Since its 12 years of existence the German HPU network has been able to adapt and to adequately respond to changing contextual conditions regarding health promotion at universities in Germany. The network should develop strategies to counteract the critical aspects and detected imbalances in order to further increase its impact on universities as healthy settings.

  13. Work Project Report: Benchmark for 100 Gbps Ethernet network analysis

    CERN Document Server

    Moutidis, Iraklis

    2016-01-01

    During the Long Shutdown 2 (2018-2019) the LHCb experiment will be upgraded in order to reach extremely high precision on the main observable of the b and c-quarks sectors. In its current state the LHCb experiment has a readout rate of 1.1 MHz within a fixed latency, which causes the collision rate to be limited. The removal of this bottleneck is one of the main objectives of the LHCb upgrade. This will be achieved by implementing a trigger-less readout system where the functionality of the trigger will be executed by software. The trigger-less readout system must be able to handle large bandwidth such as 4 TBytes/s. For that reason the design of the system will include readout boards that can transmit information at the rate of 100 Gbits/s and a high throughput local area network [1]. The main goal of my project is to create an automatized benchmark for automatic launching, scheduling and analysing the performance of the readout boards and the network, in order to decide which manufacturer offers the best so...

  14. Work Project Report: Benchmark for 100 Gbps Ethernet network analysis

    CERN Document Server

    Moutidis, Iraklis

    2016-01-01

    During the Long Shutdown 2 (2018-2019) the LHCb experiment will be upgraded in order to reach extremely high precision on the main observable of the b and c-quarks sectors. In its current state the LHCb experiment has a readout rate of 1.1 MHz within a fixed latency, which causes the collision rate to be limited. The removal of this bottleneck is one of the main objectives of the LHCb upgrade. This will be achieved by implementing a trigger-less readout system where the functionality of the trigger will be executed by software. The trigger-less readout system must be able to handle large bandwidth such as 4 TBytes/s. For that reason the design of the system will include readout boards that can transmit information at the rate of 100 Gbits/s and a high throughput local area network [1]. The main goal of my project is to create an automatized benchmark for automatic launching, scheduling and analyzing the performance of the readout boards and the network, in order to decide which manufacturer offers the best so...

  15. Kinetic analysis of PCNA clamp binding and release in the clamp loading reaction catalyzed by Saccharomyces cerevisiae replication factor C.

    Science.gov (United States)

    Marzahn, Melissa R; Hayner, Jaclyn N; Meyer, Jennifer A; Bloom, Linda B

    2015-01-01

    DNA polymerases require a sliding clamp to achieve processive DNA synthesis. The toroidal clamps are loaded onto DNA by clamp loaders, members of the AAA+family of ATPases. These enzymes utilize the energy of ATP binding and hydrolysis to perform a variety of cellular functions. In this study, a clamp loader-clamp binding assay was developed to measure the rates of ATP-dependent clamp binding and ATP-hydrolysis-dependent clamp release for the Saccharomyces cerevisiae clamp loader (RFC) and clamp (PCNA). Pre-steady-state kinetics of PCNA binding showed that although ATP binding to RFC increases affinity for PCNA, ATP binding rates and ATP-dependent conformational changes in RFC are fast relative to PCNA binding rates. Interestingly, RFC binds PCNA faster than the Escherichia coli γ complex clamp loader binds the β-clamp. In the process of loading clamps on DNA, RFC maintains contact with PCNA while PCNA closes, as the observed rate of PCNA closing is faster than the rate of PCNA release, precluding the possibility of an open clamp dissociating from DNA. Rates of clamp closing and release are not dependent on the rate of the DNA binding step and are also slower than reported rates of ATP hydrolysis, showing that these rates reflect unique intramolecular reaction steps in the clamp loading pathway. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Clamp loader ATPases and the evolution of DNA replication machinery

    Science.gov (United States)

    2012-01-01

    Clamp loaders are pentameric ATPases of the AAA+ family that operate to ensure processive DNA replication. They do so by loading onto DNA the ring-shaped sliding clamps that tether the polymerase to the DNA. Structural and biochemical analysis of clamp loaders has shown how, despite differences in composition across different branches of life, all clamp loaders undergo the same concerted conformational transformations, which generate a binding surface for the open clamp and an internal spiral chamber into which the DNA at the replication fork can slide, triggering ATP hydrolysis, release of the clamp loader, and closure of the clamp round the DNA. We review here the current understanding of the clamp loader mechanism and discuss the implications of the differences between clamp loaders from the different branches of life. PMID:22520345

  17. Clamp loader ATPases and the evolution of DNA replication machinery

    Directory of Open Access Journals (Sweden)

    Kelch Brian A

    2012-04-01

    Full Text Available Abstract Clamp loaders are pentameric ATPases of the AAA+ family that operate to ensure processive DNA replication. They do so by loading onto DNA the ring-shaped sliding clamps that tether the polymerase to the DNA. Structural and biochemical analysis of clamp loaders has shown how, despite differences in composition across different branches of life, all clamp loaders undergo the same concerted conformational transformations, which generate a binding surface for the open clamp and an internal spiral chamber into which the DNA at the replication fork can slide, triggering ATP hydrolysis, release of the clamp loader, and closure of the clamp round the DNA. We review here the current understanding of the clamp loader mechanism and discuss the implications of the differences between clamp loaders from the different branches of life.

  18. The role of developmental networks in career starters' meaning of work

    NARCIS (Netherlands)

    Janssen, Suzanne; Alberts, M.; van Vuuren, Hubrecht A.

    2014-01-01

    This study examined how career starters (age: 26-33 years) experience work meaning and how their developmental network influences this sense of work meaning. Accordingly, we interviewed 16 career starters about how they sense purpose, values, self-efficacy, and positive self-worth in their work.

  19. Link and route availability for Inter-working multi-hop wireless networks

    CSIR Research Space (South Africa)

    Salami, O

    2009-09-01

    Full Text Available In inter-working multi-hop wireless networks, establishing resilient connectivity between source-destination node pairs is a major issue. The issue of connectivity in multi-hop wireless networks have been studied. However, these analyses focused...

  20. Connectivity model for Inter-working multi-hop wireless networks

    CSIR Research Space (South Africa)

    Salami, O

    2009-08-01

    Full Text Available In Inter-working multi-hop wireless networks, establishing resilient connectivity between source-destination node pairs is a major issue. The issues of connectivity in Multi-hop wireless networks have been studied. However, these analyses focused...

  1. Peer-Learning Networks in Social Work Doctoral Education: An Interdisciplinary Model

    Science.gov (United States)

    Miller, J. Jay; Duron, Jacquelynn F.; Bosk, Emily Adlin; Finno-Velasquez, Megan; Abner, Kristin S.

    2016-01-01

    Peer-learning networks (PLN) can be valuable tools for doctoral students. Participation in these networks can aid in the completion of the dissertation, lead to increased scholarship productivity, and assist in student retention. Yet, despite the promise of PLNs, few studies have documented their effect on social work doctoral education. This…

  2. Working memory cells' behavior may be explained by cross-regional networks with synaptic facilitation.

    Directory of Open Access Journals (Sweden)

    Sergio Verduzco-Flores

    2009-08-01

    Full Text Available Neurons in the cortex exhibit a number of patterns that correlate with working memory. Specifically, averaged across trials of working memory tasks, neurons exhibit different firing rate patterns during the delay of those tasks. These patterns include: 1 persistent fixed-frequency elevated rates above baseline, 2 elevated rates that decay throughout the tasks memory period, 3 rates that accelerate throughout the delay, and 4 patterns of inhibited firing (below baseline analogous to each of the preceding excitatory patterns. Persistent elevated rate patterns are believed to be the neural correlate of working memory retention and preparation for execution of behavioral/motor responses as required in working memory tasks. Models have proposed that such activity corresponds to stable attractors in cortical neural networks with fixed synaptic weights. However, the variability in patterned behavior and the firing statistics of real neurons across the entire range of those behaviors across and within trials of working memory tasks are typical not reproduced. Here we examine the effect of dynamic synapses and network architectures with multiple cortical areas on the states and dynamics of working memory networks. The analysis indicates that the multiple pattern types exhibited by cells in working memory networks are inherent in networks with dynamic synapses, and that the variability and firing statistics in such networks with distributed architectures agree with that observed in the cortex.

  3. Pulsewidth-modulated 2-source neutral-point-clamped inverter

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Loh, Poh Chang; Gao, Feng

    2007-01-01

    set of carrier-based modulation expressions can be used for controlling the -source two-level inverter and NPC inverter with and without reduced common-mode switching. All findings presented in this paper have been confirmed in simulation and experimentally using an implemented laboratory prototype.......This paper presents the careful integration of a newly proposed Z-source topological concept to the basic neutral-point-clamped (NPC) inverter topology for designing a three-level inverter with both voltage-buck and voltage-boost capabilities. The designed Z-source NPC inverter uses two unique X......-shaped inductance-capacitance (LC) impedance networks that are connected between two isolated dc input power sources and its inverter circuitry for boosting its AC output voltage. Through the design of an appropriate pulsewidth-modulation (PWM) algorithm, the two impedance networks can be short...

  4. MANAGEMENT PROGRAMS ROAD REPAIR WORKS OF THE ROADS NETWORK

    Directory of Open Access Journals (Sweden)

    Вікторія Василівна ІГНАТЮК

    2015-05-01

    Full Text Available The paper discusses the model and algorithm optimization program of road repair works, with limited funds. Features introduction program for calculating rational level detection repair costs for the period of the program, which allows dos evolve a desired operating condition of the pavement.

  5. Making knowledge work : Intra-firm Networks, Gifts, and Innovation

    NARCIS (Netherlands)

    Dolfsma, W.A.

    2008-01-01

    Exchanging knowledge between individuals working in a firm, between but even within divisions, does not occur automatically (Szulanski 1996). It is not obvious that people exchange ideas, point each other to information that the other might use, or give feedback, even when they have no evil motives

  6. Nursing work stress: the impacts of social network structure and organizational citizenship behavior.

    Science.gov (United States)

    Tsang, Seng-Su; Chen, Tzu-Yin; Wang, Shih-Fong; Tai, Hsin-Ling

    2012-03-01

    The nursing workplace imposes significantly more stress on its employees than other workplace settings. Organizational resources, both physical and psychological, have been recognized in prior studies as important alleviators of nursing workplace stress. Whereas physical resources are less difficult to manipulate because of their tangibility, psychological resources, particularly psychological support from colleagues, are typically not deployed to greatest effect. This article investigated the alleviation of nursing work stress using resources already extant in coworker social networks. Researchers conducted a survey in a dialysis department at a medical center located in Taipei City, Taiwan. This survey measured nurse work stress, satisfaction, organizational citizenship behavior (OCB) and social network structures. Researchers employed UCINET to analyze the network structure data, which were in dyadic matrix format to estimate nurse network centralities and used partial least squares analysis to estimate research construct path coefficients and test extrapolated hypotheses. The level of OCB induced by nurse social ties was satisfactory and did not only directly increased work satisfaction but also alleviated work stress, which indirectly boosted work satisfaction. Findings suggest that managers may be able to use social network analysis to identify persons appropriate to conduct the distribution of organizational resources. Choosing those with multiple social connections can help distribute resources effectively and induce higher OCB levels within the organization. In addition, staff with strong friendship network connections may provide appropriate psychological resources (support) to coworkers. If those with high friendship network centrality receive proper counseling training, they should be in a good position to provide assistance when needed.

  7. Γ-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    Transformer based Z-source inverters are recently proposed to achieve promising buck-boost capability. They have improved higher buck-boost capability, smaller size and less components count over Z-source inverters. On the other hand, neutral point clamped inverters have less switching stress...

  8. AN ACTIVE VALVE WITH A CLAMPED MEMBRANE

    DEFF Research Database (Denmark)

    2009-01-01

    An active valve for use e.g. in fluidic microsystems is provided, wherein the active valve comprises a membrane having at least one flow gate, arranged between a first and a second substantially rigid element. Adjusting means provides an adjustment of the clamping force on membrane arranged between...

  9. ANALYTICAL BENDING SOLUTION OF ALL CLAMPED ISOTROPIC ...

    African Journals Online (AJOL)

    ANALYTICAL BENDING SOLUTION OF ALL CLAMPED ISOTROPIC RECTANGULAR PLATE ON WINKLER’S FOUNDATION USING CHARACTERISTIC ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader).

  10. Taking the 'work' out of networking: strategies for smarter, simpler network architecture and administration

    Science.gov (United States)

    Luna, C. de

    2003-01-01

    This session will help you tune up your skills and knowledge on the latest advances in network design and management, to keep your agency's data communications running at peak performance, with minimal cost and effort.

  11. Do networks do the works? Migration networks among Indian entrepreneurs in Poland and Belgium

    OpenAIRE

    Nestorowicz, Joanna

    2008-01-01

    The thesis deals with the notion of migration networks. The focal point of the study is on the functioning of networks among immigrant entrepreneurs. Indian businessmen operating in Poland and Belgium are taken as an exemplification of the analyzed process. Theoretical considerations reflect upon various theories of migration, which are relevant for the study. Based on this analysis, a holistic conceptual framework is developed, which defines three areas of research: the migration decision ma...

  12. Five-Level Z-Source Neutral Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Gao, F.; Loh, P.C.; Blaabjerg, Frede

    2007-01-01

    This paper proposes a five-level Z-source neutralpoint- clamped (NPC) inverter with two Z-source networks functioning as intermediate energy storages coupled between dc sources and NPC inverter circuitry. Analyzing the operational principles of Z-source network with partial dclink shoot-through s......This paper proposes a five-level Z-source neutralpoint- clamped (NPC) inverter with two Z-source networks functioning as intermediate energy storages coupled between dc sources and NPC inverter circuitry. Analyzing the operational principles of Z-source network with partial dclink shoot......-through scheme reveals the hidden theories in the five-level Z-source NPC inverter unlike the operational principle appeared in the general two-level Z-source inverter, so that the five-level Z-source NPC inverter can be designed with the modulation of carrier-based phase disposition (PD) or alternative phase...

  13. The Impact of Auditory Working Memory Training on the Fronto-Parietal Working Memory Network

    Directory of Open Access Journals (Sweden)

    Julia eSchneiders

    2012-06-01

    Full Text Available Working memory training has been widely used to investigate working memory processes. We have shown previously that visual working memory benefits only from intra-modal visual but not from across-modal auditory working memory training. In the present functional magnetic resonance imaging study we examined whether auditory working memory processes can also be trained specifically and which training-induced activation changes accompany theses effects. It was investigated whether working memory training with strongly distinct auditory materials transfers exclusively to an auditory (intra-modal working memory task or whether it generalizes to an (across-modal visual working memory task. We used an adaptive n-back training with tonal sequences and a passive control condition. The memory training led to a reliable training gain. Transfer effects were found for the (intra-modal auditory but not for the (across-modal visual 2-back task. Training-induced activation changes in the auditory 2-back task were found in two regions in the right inferior frontal gyrus. These effects confirm our previous findings in the visual modality and extends intra-modal effects to the auditory modality. These results might reflect increased neural efficiency in auditory working memory processes as in the right inferior frontal gyrus is frequently found in maintaining modality-specific auditory information. By this, these effects are analogical to the activation decreases in the right middle frontal gyrus for the visual modality in our previous study. Furthermore, task-unspecific (across-modal activation decreases in the visual and auditory 2-back task were found in the right inferior parietal lobule and the superior portion of the right middle frontal gyrus reflecting less demands on general attentional control processes. These data are in good agreement with across-modal activation decreases within the same brain regions on a visual 2-back task reported previously.

  14. Dynamic Connectivity between Brain Networks Supports Working Memory: Relationships to Dopamine Release and Schizophrenia

    Science.gov (United States)

    Van Snellenberg, Jared X.; Benavides, Caridad; Slifstein, Mark; Wang, Zhishun; Moore, Holly; Abi-Dargham, Anissa

    2016-01-01

    Connectivity between brain networks may adapt flexibly to cognitive demand, a process that could underlie adaptive behaviors and cognitive deficits, such as those observed in neuropsychiatric conditions like schizophrenia. Dopamine signaling is critical for working memory but its influence on internetwork connectivity is relatively unknown. We addressed these questions in healthy humans using functional magnetic resonance imaging (during an n-back working-memory task) and positron emission tomography using the radiotracer [11C]FLB457 before and after amphetamine to measure the capacity for dopamine release in extrastriatal brain regions. Brain networks were defined by spatial independent component analysis (ICA) and working-memory-load-dependent connectivity between task-relevant pairs of networks was determined via a modified psychophysiological interaction analysis. For most pairs of task-relevant networks, connectivity significantly changed as a function of working-memory load. Moreover, load-dependent changes in connectivity between left and right frontoparietal networks (Δ connectivity lFPN-rFPN) predicted interindividual differences in task performance more accurately than other fMRI and PET imaging measures. Δ Connectivity lFPN-rFPN was not related to cortical dopamine release capacity. A second study in unmedicated patients with schizophrenia showed no abnormalities in load-dependent connectivity but showed a weaker relationship between Δ connectivity lFPN-rFPN and working memory performance in patients compared with matched healthy individuals. Poor working memory performance in patients was, in contrast, related to deficient cortical dopamine release. Our findings indicate that interactions between brain networks dynamically adapt to fluctuating environmental demands. These dynamic adaptations underlie successful working memory performance in healthy individuals and are not well predicted by amphetamine-induced dopamine release capacity. SIGNIFICANCE

  15. Changes in Brain Network Efficiency and Working Memory Performance in Aging

    Science.gov (United States)

    Stanley, Matthew L.; Simpson, Sean L.; Dagenbach, Dale; Lyday, Robert G.; Burdette, Jonathan H.; Laurienti, Paul J.

    2015-01-01

    Working memory is a complex psychological construct referring to the temporary storage and active processing of information. We used functional connectivity brain network metrics quantifying local and global efficiency of information transfer for predicting individual variability in working memory performance on an n-back task in both young (n = 14) and older (n = 15) adults. Individual differences in both local and global efficiency during the working memory task were significant predictors of working memory performance in addition to age (and an interaction between age and global efficiency). Decreases in local efficiency during the working memory task were associated with better working memory performance in both age cohorts. In contrast, increases in global efficiency were associated with much better working performance for young participants; however, increases in global efficiency were associated with a slight decrease in working memory performance for older participants. Individual differences in local and global efficiency during resting-state sessions were not significant predictors of working memory performance. Significant group whole-brain functional network decreases in local efficiency also were observed during the working memory task compared to rest, whereas no significant differences were observed in network global efficiency. These results are discussed in relation to recently developed models of age-related differences in working memory. PMID:25875001

  16. Work, gender, and social networks: work experiences of fashion fair managers on Facebook

    Directory of Open Access Journals (Sweden)

    Andrea González Medina

    2017-07-01

    Full Text Available The article questions the classical paradigms of work society, which emphasized the industrial-worker-men. In contrast, it affirms the existence of a reorganization of the work world, reflected in many ways, such as non-industrial and labor regulation activities, as well as the introduction of information and communication technologies. The research focused on two fundamental aspects of said reorganization; the proliferation of activities in the informal sector and the use of information and communication technologies at work. In order to understand these lines of analysis, we selected the case of e-commerce carried out on the Facebook platform. Although this platform has been co-opted by big companies to advertise products, it is also possible to observe the emergence of an informal work market made up of women who use that technological tool to carry out business on Facebook through ‘fashion fairs’. The article argues that the work carried out in such fairs is permeated by gender stereotypes. Therefore, its objective is to understand the configuration of subjectivities on the basis of gender stereotypes in the current work environment. In order to achieve this, it proposed a qualitative methodology to analyze labor aspects, use of time, and interaction with technology. The understanding of the work included the following central themes: production of services, de-territorialization of work, and production of symbols, and each one of these was related to a gender stereotype: women in the informal sector; the articulation between domestic-extra- omestic/productive-reproductive work; and the feminization of the products market, respectively. The article seeks to make evident the processes involved in the production of services and the conditions of informality in which women are involved. The article is structured as follows: the first section conceptualizes the activity according to the categories of nontraditional work

  17. Work in progress: a channel selection algorithm for a TVWS mesh network

    CSIR Research Space (South Africa)

    Zlobinsky, Natasha

    2016-09-01

    Full Text Available The concept behind this work is to build mesh net-works in the TVWS band for developing regions to improve internet access opportunities. The purpose is to solve a pertinent problem within the context, namely to find an optimal or almost optimal...

  18. Is networking different with part-time working colleagues? A study of medical teams.

    NARCIS (Netherlands)

    Heiligers, P.; Jong, J. de; Groenewegen, P.; Hingstman, L.

    2007-01-01

    Changes in work arrangements like the introduction of part-time work can affect both formal and informal organization. This study will focus on informal networks amongst teams of medical specialists, some but not all of which include part-time workers. Are there notable differences in the structure

  19. Single molecule study of a processivity clamp sliding on DNA

    Energy Technology Data Exchange (ETDEWEB)

    Laurence, T A; Kwon, Y; Johnson, A; Hollars, C; O?Donnell, M; Camarero, J A; Barsky, D

    2007-07-05

    Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder.

  20. 21 CFR 882.5175 - Carotid artery clamp.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carotid artery clamp. 882.5175 Section 882.5175...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5175 Carotid artery clamp. (a) Identification. A carotid artery clamp is a device that is surgically placed around a patient's carotid artery...

  1. 21 CFR 876.5160 - Urological clamp for males.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urological clamp for males. 876.5160 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for males. (a) Identification. A urological clamp for males is a device used to close the urethra of a male to...

  2. Multilevel-clamped multilevel converters (MLC2)

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Bellar, Maria Dias; Muñoz-Aguliar, Raúl Santiago

    2012-01-01

    This letter introduces a new series of multilevel (ML) converters based on the ML clamping concept. By applying this technique, a ML clamping unit (MCU) conveys additional levels for synthesizing the output waveforms of a diode-clampedML dc– ac power converter. The basic building block of the ML ...

  3. High-speed dynamic-clamp interface

    Science.gov (United States)

    Yang, Yang; Adowski, Timothy; Ramamurthy, Bina; Neef, Andreas

    2015-01-01

    The dynamic-clamp technique is highly useful for mimicking synaptic or voltage-gated conductances. However, its use remains rare in part because there are few systems, and they can be expensive and difficult for less-experienced programmers to implement. Furthermore, some conductances (such as sodium channels) can be quite rapid or may have complex voltage sensitivity, so high speeds are necessary. To address these issues, we have developed a new interface that uses a common personal computer platform with National Instruments data acquisition and WaveMetrics IGOR to provide a simple user interface. This dynamic clamp implements leak and linear synaptic conductances as well as a voltage-dependent synaptic conductance and kinetic channel conductances based on Hodgkin-Huxley or Markov models. The speed of the system can be assayed using a testing mode, and currently speeds of >100 kHz (10 μs per cycle) are achievable with short latency and little jitter. PMID:25632075

  4. Towards a Dynamic Clamp for Neurochemical Modalities

    Directory of Open Access Journals (Sweden)

    Catalina Maria Rivera

    2015-05-01

    Full Text Available The classic dynamic clamp technique uses a real-time electrical interface between living cells and neural simulations in order to investigate hypotheses about neural function and structure. One of the acknowledged drawbacks of that technique is the limited control of the cells’ chemical microenvironment. In this manuscript, we use a novel combination of nanosensor and microfluidic technology and microfluidic and neural simulations to add sensing and control of chemical concentrations to the dynamic clamp technique. Specifically, we use a microfluidic lab-on-a-chip to generate distinct chemical concentration gradients (ions or neuromodulators, to register the concentrations with embedded nanosensors and use the processed signals as an input to simulations of a neural cell. The ultimate goal of this project is to close the loop and provide sensor signals to the microfluidic lab-on-a-chip to mimic the interaction of the simulated cell with other cells in its chemical environment.

  5. Dental dam clamp adaptation method on carved gypsum cast.

    Science.gov (United States)

    Cazacu, N C E

    2014-01-01

    Dental Dam is the safest and most efficient isolation technique in endodontics and restorative dentistry, but it also used in esthetics, orthodontics, prosthetics, pedodontics and periodontology (for teeth immobilization). While in most cases the standard clamps are efficient, in some clinical situations clamp adaptation is mandatory in order to assure a tight contact on the tooth. The purpose of this study is to list the elements of the clamp, which should be modified in order to assure a secure constriction of the clamp on the anchor tooth, by using the carved gypsum cast method. 100 patients were examined, diagnosed and treated for various diagnoses like simple decay, gangrene, chronic apical periodontitis, and endodontic retreatments. The clamps used in this study were produced by Hu-Friedy, Hygenic, KKD, SDI, Hager & Werken. In 10 cases, the anchor tooth did not provide enough stability to the standard clamp--as provided by the producer. Therefore, we have done some adjustments to some of the elements of the clamp: the arch, the wings, the plateau, the active area, and the contact points. In 6 cases, major clamp adaptations on carved gypsum cast were imperative. The classic clamps cannot provide a grip to be enough in all the clinical cases due to the huge variety and position and implantation of the anchor teeth. Therefore, in such situations, the clamps should be adapted in order to provide stability and assure the safe isolation during the treatment. The modified clamps will be useful in similar cases, so they must be kept.

  6. Access, engagement, networks, and norms: Dimensions of social capital at work in a first grade classroom

    Science.gov (United States)

    Wexler-Robock, Stephanie

    Social capital refers to access and use of resources available through one's networks to solve problems, and the norms that reflect inclusive or exclusive access to those networks and resources. Research has found positive relationships between social capital, academic achievement, and attainment. Studies, however, have generally examined social capital through factors that occur outside the classroom; students who have social capital, acquired through their family and community relationships, seem to be more successful academically. Limited research has explored what if any factors within the classroom might impact the production, and nature of social capital, or its workings in a classroom. The purpose of this study was to explore the workings and nature of classroom social capital, including its possible relationships to engagement and cognition among 5 student participants. Using methods of qualitative data collection, mixed methods were used to analyze information resources, participants' networking, student work, and classroom discourse. Eight interdependent networking factors and 3 overarching patterns of norms were discovered. The networking factors reflected the structure, content, processes, purposes, and acceptability of participants' networking. The norms, also working interdependently, appeared to promote or inhibit among other things, engagement in networking, help seeking, access, sharing, and intertextual use of diverse, often complex sources of information. Through interaction of the 8 factors and 3 overarching norms, ongoing outcomes of networking appeared to include the creation of bridging (inclusive) and bonding (exclusive) forms of social capital, and depth of scientific conceptual understanding, in this case, about birds. Bridging social capital appeared related to willingness to engage in strong and weak tie networking, help seeking, intertextuality, and possibly to mastery goal orientation for all participants, regardless of reading level

  7. The management of interaction network. The “In-between” concept within Social Work and Counseling

    Directory of Open Access Journals (Sweden)

    Jesús Hernández-Aristu

    2015-06-01

    Full Text Available We are familiar with the field of group interaction through the traditional work of Kurt Lewin and also systemic thinking talks about network interaction that builds up the system. Martin Buber also discusses the “in-between” concept as the third element.The therapist or counselor, social worker and clients are part of an interaction network, representing therapeutic and social working situations. Success in treatment and reflective processes, depends on the perception and management of the situation by  experts.  Painting the moment of interaction offers the possibility to know what happens between professional and client. Afterwards it is possible to reflect on this experience.

  8. Unequal pressure distribution along the jaws of currently available vascular clamps: do we need a new aortic clamp?

    Science.gov (United States)

    Rylski, Bartosz; Schmid, Claudius; Beyersdorf, Friedhelm; Kari, Fabian Alexander; Kondov, Stoyan; Lutz, Lisa; Werner, Martin; Czerny, Martin; Siepe, Matthias

    2016-06-01

    The pressure along vascular clamp jaws may be unequally distributed, with greater pressure near the clamp hinge than at its top. Such unequal pressure distribution may cause aortic injury, especially in large aortas. We evaluated pressure distribution along different currently availably clamp jaws. Seven descending thoracic aortas from pigs (diameter 2.0-3.0 cm) were plainly dissected and all side arteries closed. Aortas were filled up with water and cross-clamped. The pressure inside the aorta was raised to 100 mmHg and the aorta was clamped so tightly that no water exited from the distal aortic end. Each aorta was clamped seven times at different sites with the following clamps: DeBakey, Satinsky, femoral, iliac, Chitwood, angled handle Fogarty and straight handle Fogarty. The pressure along the clamp jaws was measured with a pressure-detecting film placed between the clamp jaws and aorta. The collagen-fibre disorganization was examined in haemotoxylin-eosin- and Elastica van Gieson-stained tissue samples. The DeBakey clamp revealed the lowest maximum pressure along the clamp jaws after complete aortic occlusion (1.43 ± 0.49 MPa), whereas the Chitwood clamp's pressure was the highest (3.26 ± 1.93 MPa, P clamp displayed the lowest difference between maximum pressures across the jaws (33%), with the greatest difference measured in the iliac (72%) and Chitwood (66%) clamps. The highest collagen-fibre disorganization score was observed in the proximal-to-the-clamp-hinge quartile after clamping with the angled handle Fogarty (2.8 ± 0.4), straight handle Fogarty (2.3 ± 0.8) and Chitwood (2.3 ± 0.5) clamps. The pressure along clamp jaws is unequally distributed in all the currently available vascular clamps. The Chitwood clamp is associated with the highest maximum pressure during complete aortic occlusion and with the most unequal pressure distribution along the jaws. © The Author 2015. Published by Oxford University Press on behalf of the European Association

  9. Distinction in coherent neural network between resting and working brain states.

    Science.gov (United States)

    Liu, Xiao; Zhu, Xiao-Hong; Chen, Wei

    2011-01-01

    The resting brain is not silent; rather, it is characterized by organized resting-state networks showing spontaneous and coherent neuronal activities, which can be mapped using the spatiotemporal correlation of blood oxygenation level-dependent (BOLD) signal fluctuations measured by functional magnetic resonance imaging (fMRI). However, it remains elusive whether the similar fMRI approach is able to image the coherent network in a working brain, and if yes, whether there is a distinction between the resting- and working-state coherent networks. This study aimed to address these questions in the human visual cortex with a desired activation paradigm using continuous, sustained visual stimuli. It was found that the resting-state coherent network covering the human visual cortex was spatially reorganized during the stimulation into two coherent networks with distinct temporal characteristics of BOLD fluctuations: one covering the activated visual cortical region and the other covering the remaining (nonactivated) visual cortex. The stimulus-specific reorganization of the coherent network observed in the present fMRI study in human is consistent with previous electrophysiological findings from animal studies, and may suggest an essential mechanism for brain functioning. Finally, a similar fMRI experiment was also conducted under brief, short stimulation to examine how the stimulation paradigm can affect the observations.

  10. THE PECULIARITIES OF WORK OF THE EUROPEAN NETWORK OF HEALTH PROMOTING SCHOOLS (COMPARATIVE ANALYSIS

    Directory of Open Access Journals (Sweden)

    T.S. Iermakova

    2013-10-01

    Full Text Available Purpose – to analyze the main peculiarities of European Network of Health Promoting Schools functioning in European Union and Ukraine. Results. Students are a big group of population that demand introduction of health education in modern rhythm of life. A great example of such education is schools of Members States of European Union. Address to experience of forming of students’ health culture in the Health Promoting Schools in countries of European Union, experience of that can become an example for the countries of post-soviet space and Ukraine in particular. In the article is shown main peculiarities and structure of the work of such school network. Single out the main principles and approached of network activity. Conclusions. The ENHPS is intended above all to be of practical help to schools and those working with schools on becoming more effective in health promotion and therefore ultimately more effective in meeting their educational goals.

  11. Analysis of route availability in inter-working multi-hop wireless networks

    CSIR Research Space (South Africa)

    Salami, O

    2009-07-01

    Full Text Available In order to link a source-destination node pair in inter-working multi-hop wireless networks, links or routes must first be available. It is only after establishing the availability of links and routes between nodes that factors which affect...

  12. Social Media and Networking Technologies: An Analysis of Collaborative Work and Team Communication

    Science.gov (United States)

    Okoro, Ephraim A.; Hausman, Angela; Washington, Melvin C.

    2012-01-01

    Digital communication increases students' learning outcomes in higher education. Web 2.0 technologies encourages students' active engagement, collaboration, and participation in class activities, facilitates group work, and encourages information sharing among students. Familiarity with organizational use and sharing in social networks aids…

  13. The Second Workshop of the European Network for Work Information (ENWI)

    DEFF Research Database (Denmark)

    Borlund, Pia; Mandl, Thomas; Womser-Hacker, Christa

    2013-01-01

    The second workshop of ENWI was held in Malmö, Sweden, June 12-13, 2013. ENWI is the European Network for Work Information which intends to establish a group of researchers who share a common interest in the study of workplace information practices. The better understanding of people and their ta...

  14. Working Memory Modulation of Frontoparietal Network Connectivity in First-Episode Schizophrenia

    DEFF Research Database (Denmark)

    Nielsen, Jesper Duemose; Madsen, Kristoffer Hougaard; Wang, Zheng

    2017-01-01

    Working memory (WM) impairment is regarded as a core aspect of schizophrenia. However, the neural mechanisms behind this cognitive deficit remain unclear. The connectivity of a frontoparietal network is known to be important for subserving WM. Using functional magnetic resonance imaging...

  15. The Formation of the Surface during AN Abrasive Finishing at Constant and Variable Clamping Forces: Finishing at Constant and Variable Clamping Forces

    Science.gov (United States)

    Muratov, Karim Ravilevich; Muratov, Ravil Arifovich; Ablyaz, Timur Rizovich; Gashev, Evgeniy Anatolyevich

    2017-06-01

    In this work the flat abrasive finishing process is reported. The mechanical and chemical phenomena taking place during the finishing process are described. The most common forming process schemes observed during abrasive treatment are reviewed. The schemes of pulsed, geometrical and energetic models are discussed. On the basis of the energetic hypothesis and Preston hypothesis, the rational law of clamping force variation during the finishing is established. This law allowed for the stabilization of the contact pressure and an increase of the treatment efficiency. An exponential dependence of a boundary contact area variation during the finishing of planes with different initial profiles of the macro-topography is developed. An experimental confirmation of the Preston hypothesis during the abrasive finishing is carried out with the plane-finishing machine “Rastr 220”. The comparison experiments are carried out at constant and variable clamping forces of the treated surface towards the tool. It is found that by varying the forces according to the exponential law (i.e. similar to the changing of the boundary contact area during the abrasive finishing) the process efficiency is increasing by a factor of 2.5-3. It is shown that the changes of the root mean square deviation σ of the roughness Ra of a treated surface in the beginning of the process (at time t=1 min) during the finishing at a constant clamping force is two times higher compared to the treatment at a variable clamping force in the same time period.

  16. Improving safety and efficiency during emergent central venous catheter placement with a needleless securing clamp.

    Science.gov (United States)

    Silich, Bert; Chrobak, Paul; Siu, Jeffrey; Schlichting, Adam; Patel, Samir; Yang, James

    2013-08-01

    To compare the needleless securing clamp to the traditional suture-secured clamp for central venous catheters. Compare the holding strength of each type of clamps by measuring the amount of kinetic energy absorbed, ask 20 physicians to evaluate the clamp placement using sutures or staples, and summarise the clamps effectiveness and complications in 10 patients. Compared to sutured clamp, the needleless clamp was more secure. The needleless clamp was also significantly better with regard to ease of use, safety, perceived strength (p value clamps. Without incurring complications or increasing risk to patients, the needleless clamp is secure and improves safety and efficiency for physicians.

  17. The role of bridging organizations in environmental management: examining social networks in working groups

    Directory of Open Access Journals (Sweden)

    Adam A. Kowalski

    2015-06-01

    Full Text Available The linkage of diverse sets of actors and knowledge systems across management levels and institutional boundaries often poses one of the greatest challenges in adaptive management of natural resources. Bridging organizations can facilitate interactions among actors in management settings by lowering the transaction costs of collaboration. The Center for Ocean Solutions (COS is an example of a bridging organization that is focused on linking actors within the ocean sciences and governance arena through the use of working groups. This research examines how network connections between group members affect working group functionality and, more specifically, whether cohesive network structures allow groups to more effectively achieve their goals and objectives. A mixed-methods approach, incorporating both qualitative and quantitative data collection and analysis methods, is employed to understand the structural characteristics of COS working groups. The study finds that cohesive network structures are not associated with increased working group functionality. Strong, centralized leadership is a better predictor of working group success in achieving goals and objectives.

  18. Using spatial multiple regression to identify intrinsic connectivity networks involved in working memory performance.

    Science.gov (United States)

    Gordon, Evan M; Stollstorff, Melanie; Vaidya, Chandan J

    2012-07-01

    Many researchers have noted that the functional architecture of the human brain is relatively invariant during task performance and the resting state. Indeed, intrinsic connectivity networks (ICNs) revealed by resting-state functional connectivity analyses are spatially similar to regions activated during cognitive tasks. This suggests that patterns of task-related activation in individual subjects may result from the engagement of one or more of these ICNs; however, this has not been tested. We used a novel analysis, spatial multiple regression, to test whether the patterns of activation during an N-back working memory task could be well described by a linear combination of ICNs delineated using Independent Components Analysis at rest. We found that across subjects, the cingulo-opercular Set Maintenance ICN, as well as right and left Frontoparietal Control ICNs, were reliably activated during working memory, while Default Mode and Visual ICNs were reliably deactivated. Further, involvement of Set Maintenance, Frontoparietal Control, and Dorsal Attention ICNs was sensitive to varying working memory load. Finally, the degree of left Frontoparietal Control network activation predicted response speed, while activation in both left Frontoparietal Control and Dorsal Attention networks predicted task accuracy. These results suggest that a close relationship between resting-state networks and task-evoked activation is functionally relevant for behavior, and that spatial multiple regression analysis is a suitable method for revealing that relationship. Copyright © 2011 Wiley-Liss, Inc.

  19. Using Spatial Multiple Regression to Identify Intrinsic Connectivity Networks Involved in Working Memory Performance

    Science.gov (United States)

    Gordon, Evan M.; Stollstorff, Melanie; Vaidya, Chandan J.

    2012-01-01

    Many researchers have noted that the functional architecture of the human brain is relatively invariant during task performance and the resting state. Indeed, intrinsic connectivity networks (ICNs) revealed by resting-state functional connectivity analyses are spatially similar to regions activated during cognitive tasks. This suggests that patterns of task-related activation in individual subjects may result from the engagement of one or more of these ICNs; however, this has not been tested. We used a novel analysis, spatial multiple regression, to test whether the patterns of activation during an N-back working memory task could be well described by a linear combination of ICNs delineated using Independent Components Analysis at rest. We found that across subjects, the cingulo-opercular Set Maintenance ICN, as well as right and left Frontoparietal Control ICNs, were reliably activated during working memory, while Default Mode and Visual ICNs were reliably deactivated. Further, involvement of Set Maintenance, Frontoparietal Control, and Dorsal Attention ICNs was sensitive to varying working memory load. Finally, the degree of left Frontoparietal Control network activation predicted response speed, while activation in both left Frontoparietal Control and Dorsal Attention networks predicted task accuracy. These results suggest that a close relationship between resting-state networks and task-evoked activation is functionally relevant for behavior, and that spatial multiple regression analysis is a suitable method for revealing that relationship. PMID:21761505

  20. Cortical networks for working memory and executive functions sustain the conscious resting state in man.

    Science.gov (United States)

    Mazoyer, B; Zago, L; Mellet, E; Bricogne, S; Etard, O; Houdé, O; Crivello, F; Joliot, M; Petit, L; Tzourio-Mazoyer, N

    2001-02-01

    The cortical anatomy of the conscious resting state (REST) was investigated using a meta-analysis of nine positron emission tomography (PET) activation protocols that dealt with different cognitive tasks but shared REST as a common control state. During REST, subjects were in darkness and silence, and were instructed to relax, refrain from moving, and avoid systematic thoughts. Each protocol contrasted REST to a different cognitive task consisting either of language, mental imagery, mental calculation, reasoning, finger movement, or spatial working memory, using either auditory, visual or no stimulus delivery, and requiring either vocal, motor or no output. A total of 63 subjects and 370 spatially normalized PET scans were entered in the meta-analysis. Conjunction analysis revealed a network of brain areas jointly activated during conscious REST as compared to the nine cognitive tasks, including the bilateral angular gyrus, the left anterior precuneus and posterior cingulate cortex, the left medial frontal and anterior cingulate cortex, the left superior and medial frontal sulcus, and the left inferior frontal cortex. These results suggest that brain activity during conscious REST is sustained by a large scale network of heteromodal associative parietal and frontal cortical areas, that can be further hierarchically organized in an episodic working memory parieto-frontal network, driven in part by emotions, working under the supervision of an executive left prefrontal network.

  1. Gender differences in working memory networks: a BrainMap meta-analysis.

    Science.gov (United States)

    Hill, Ashley C; Laird, Angela R; Robinson, Jennifer L

    2014-10-01

    Gender differences in psychological processes have been of great interest in a variety of fields. While the majority of research in this area has focused on specific differences in relation to test performance, this study sought to determine the underlying neurofunctional differences observed during working memory, a pivotal cognitive process shown to be predictive of academic achievement and intelligence. Using the BrainMap database, we performed a meta-analysis and applied activation likelihood estimation to our search set. Our results demonstrate consistent working memory networks across genders, but also provide evidence for gender-specific networks whereby females consistently activate more limbic (e.g., amygdala and hippocampus) and prefrontal structures (e.g., right inferior frontal gyrus), and males activate a distributed network inclusive of more parietal regions. These data provide a framework for future investigations using functional or effective connectivity methods to elucidate the underpinnings of gender differences in neural network recruitment during working memory tasks. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Effective visual working memory capacity: an emergent effect from the neural dynamics in an attractor network.

    Directory of Open Access Journals (Sweden)

    Laura Dempere-Marco

    Full Text Available The study of working memory capacity is of outmost importance in cognitive psychology as working memory is at the basis of general cognitive function. Although the working memory capacity limit has been thoroughly studied, its origin still remains a matter of strong debate. Only recently has the role of visual saliency in modulating working memory storage capacity been assessed experimentally and proved to provide valuable insights into working memory function. In the computational arena, attractor networks have successfully accounted for psychophysical and neurophysiological data in numerous working memory tasks given their ability to produce a sustained elevated firing rate during a delay period. Here we investigate the mechanisms underlying working memory capacity by means of a biophysically-realistic attractor network with spiking neurons while accounting for two recent experimental observations: 1 the presence of a visually salient item reduces the number of items that can be held in working memory, and 2 visually salient items are commonly kept in memory at the cost of not keeping as many non-salient items. Our model suggests that working memory capacity is determined by two fundamental processes: encoding of visual items into working memory and maintenance of the encoded items upon their removal from the visual display. While maintenance critically depends on the constraints that lateral inhibition imposes to the mnemonic activity, encoding is limited by the ability of the stimulated neural assemblies to reach a sufficiently high level of excitation, a process governed by the dynamics of competition and cooperation among neuronal pools. Encoding is therefore contingent upon the visual working memory task and has led us to introduce the concept of effective working memory capacity (eWMC in contrast to the maximal upper capacity limit only reached under ideal conditions.

  3. Effective Visual Working Memory Capacity: An Emergent Effect from the Neural Dynamics in an Attractor Network

    Science.gov (United States)

    Dempere-Marco, Laura; Melcher, David P.; Deco, Gustavo

    2012-01-01

    The study of working memory capacity is of outmost importance in cognitive psychology as working memory is at the basis of general cognitive function. Although the working memory capacity limit has been thoroughly studied, its origin still remains a matter of strong debate. Only recently has the role of visual saliency in modulating working memory storage capacity been assessed experimentally and proved to provide valuable insights into working memory function. In the computational arena, attractor networks have successfully accounted for psychophysical and neurophysiological data in numerous working memory tasks given their ability to produce a sustained elevated firing rate during a delay period. Here we investigate the mechanisms underlying working memory capacity by means of a biophysically-realistic attractor network with spiking neurons while accounting for two recent experimental observations: 1) the presence of a visually salient item reduces the number of items that can be held in working memory, and 2) visually salient items are commonly kept in memory at the cost of not keeping as many non-salient items. Our model suggests that working memory capacity is determined by two fundamental processes: encoding of visual items into working memory and maintenance of the encoded items upon their removal from the visual display. While maintenance critically depends on the constraints that lateral inhibition imposes to the mnemonic activity, encoding is limited by the ability of the stimulated neural assemblies to reach a sufficiently high level of excitation, a process governed by the dynamics of competition and cooperation among neuronal pools. Encoding is therefore contingent upon the visual working memory task and has led us to introduce the concept of effective working memory capacity (eWMC) in contrast to the maximal upper capacity limit only reached under ideal conditions. PMID:22952608

  4. Effective visual working memory capacity: an emergent effect from the neural dynamics in an attractor network.

    Science.gov (United States)

    Dempere-Marco, Laura; Melcher, David P; Deco, Gustavo

    2012-01-01

    The study of working memory capacity is of outmost importance in cognitive psychology as working memory is at the basis of general cognitive function. Although the working memory capacity limit has been thoroughly studied, its origin still remains a matter of strong debate. Only recently has the role of visual saliency in modulating working memory storage capacity been assessed experimentally and proved to provide valuable insights into working memory function. In the computational arena, attractor networks have successfully accounted for psychophysical and neurophysiological data in numerous working memory tasks given their ability to produce a sustained elevated firing rate during a delay period. Here we investigate the mechanisms underlying working memory capacity by means of a biophysically-realistic attractor network with spiking neurons while accounting for two recent experimental observations: 1) the presence of a visually salient item reduces the number of items that can be held in working memory, and 2) visually salient items are commonly kept in memory at the cost of not keeping as many non-salient items. Our model suggests that working memory capacity is determined by two fundamental processes: encoding of visual items into working memory and maintenance of the encoded items upon their removal from the visual display. While maintenance critically depends on the constraints that lateral inhibition imposes to the mnemonic activity, encoding is limited by the ability of the stimulated neural assemblies to reach a sufficiently high level of excitation, a process governed by the dynamics of competition and cooperation among neuronal pools. Encoding is therefore contingent upon the visual working memory task and has led us to introduce the concept of effective working memory capacity (eWMC) in contrast to the maximal upper capacity limit only reached under ideal conditions.

  5. Medial Clamp Tine Positioning Affects Ankle Syndesmosis Malreduction.

    Science.gov (United States)

    Cosgrove, Christopher T; Putnam, Sara M; Cherney, Steven M; Ricci, William M; Spraggs-Hughes, Amanda; McAndrew, Christopher M; Gardner, Michael J

    2017-08-01

    To determine whether the position of the medial clamp tine during syndesmotic reduction affected reduction accuracy. Prospective cohort. Urban Level 1 trauma center. Seventy-two patients with operatively treated syndesmotic injuries. Patients underwent operative fixation of their ankle syndesmotic injuries using reduction forceps. The position of the medial clamp tine was then recorded with intraoperative fluoroscopy. Malreduction rates were then assessed with bilateral ankle computerized tomography. Fibular position within the incisura was measured with respect to the uninjured side to determine whether a malreduction had occurred. Malreductions were then analyzed for associations with injury pattern, patient demographics, and the location of the medial clamp tine. A statistically significant association was found between medial clamp position and sagittal plane syndesmosis malreduction. In reference to anterior fibular translation, there was a 0% malreduction rate in the 18 patients where the clamp tine was placed in the anterior third, a 19.4% malreduction rate in the middle third, and 60% malreduction rate in the posterior third (P = 0.006). In reference to posterior fibular translation, there was a 11.1% malreduction when clamp placement was in the anterior third, a 16.1% malreduction rate in the middle third, and 60% malreduction rate in the posterior third (P = 0.062). There were no significant associations between medial clamp position and coronal plane malreductions (overcompression or undercompression) (P = 1). When using reduction forceps for syndesmotic reduction, the position of the medial clamp tine can be highly variable. The angle created with off-axis syndesmotic clamping is likely a major culprit in iatrogenic malreduction. Sagittal plane malreduction appears to be highly sensitive to clamp obliquity, which is directly related to the medial clamp tine placement. Based on these data, we recommend placing the medial clamp tine in the anterior third

  6. Delayed versus Immediate Cord Clamping in Preterm Infants.

    Science.gov (United States)

    Tarnow-Mordi, William; Morris, Jonathan; Kirby, Adrienne; Robledo, Kristy; Askie, Lisa; Brown, Rebecca; Evans, Nicholas; Finlayson, Sarah; Fogarty, Michael; Gebski, Val; Ghadge, Alpana; Hague, Wendy; Isaacs, David; Jeffery, Michelle; Keech, Anthony; Kluckow, Martin; Popat, Himanshu; Sebastian, Lucille; Aagaard, Kjersti; Belfort, Michael; Pammi, Mohan; Abdel-Latif, Mohamed; Reynolds, Graham; Ariff, Shabina; Sheikh, Lumaan; Chen, Yan; Colditz, Paul; Liley, Helen; Pritchard, Margo; de Luca, Daniele; de Waal, Koert; Forder, Peta; Duley, Lelia; El-Naggar, Walid; Gill, Andrew; Newnham, John; Simmer, Karen; Groom, Katie; Weston, Philip; Gullam, Joanna; Patel, Harshad; Koh, Guan; Lui, Kei; Marlow, Neil; Morris, Scott; Sehgal, Arvind; Wallace, Euan; Soll, Roger; Young, Leslie; Sweet, David; Walker, Susan; Watkins, Andrew; Wright, Ian; Osborn, David; Simes, John

    2017-12-21

    The preferred timing of umbilical-cord clamping in preterm infants is unclear. We randomly assigned fetuses from women who were expected to deliver before 30 weeks of gestation to either immediate clamping of the umbilical cord (≤10 seconds after delivery) or delayed clamping (≥60 seconds after delivery). The primary composite outcome was death or major morbidity (defined as severe brain injury on postnatal ultrasonography, severe retinopathy of prematurity, necrotizing enterocolitis, or late-onset sepsis) by 36 weeks of postmenstrual age. Analyses were performed on an intention-to-treat basis, accounting for multiple births. Of 1634 fetuses that underwent randomization, 1566 were born alive before 30 weeks of gestation; of these, 782 were assigned to immediate cord clamping and 784 to delayed cord clamping. The median time between delivery and cord clamping was 5 seconds and 60 seconds in the respective groups. Complete data on the primary outcome were available for 1497 infants (95.6%). There was no significant difference in the incidence of the primary outcome between infants assigned to delayed clamping (37.0%) and those assigned to immediate clamping (37.2%) (relative risk, 1.00; 95% confidence interval, 0.88 to 1.13; P=0.96). The mortality was 6.4% in the delayed-clamping group and 9.0% in the immediate-clamping group (P=0.03 in unadjusted analyses; P=0.39 after post hoc adjustment for multiple secondary outcomes). There were no significant differences between the two groups in the incidences of chronic lung disease or other major morbidities. Among preterm infants, delayed cord clamping did not result in a lower incidence of the combined outcome of death or major morbidity at 36 weeks of gestation than immediate cord clamping. (Funded by the Australian National Health and Medical Research Council [NHMRC] and the NHMRC Clinical Trials Centre; APTS Australian and New Zealand Clinical Trials Registry number, ACTRN12610000633088 .).

  7. Delayed cord clamping and cord gas analysis at birth.

    Science.gov (United States)

    Xodo, Serena; Xodo, Luigi; Berghella, Vincenzo

    2018-01-01

    Delayed cord clamping for at least 60 s in both term and preterm babies is a major recent change in clinical care. Delayed cord clamping has several effects on other possible interventions. One of these is the effect of delayed cord clamping on umbilical artery gas analysis. When indicated, umbilical artery gas analysis can safely be done either with early cord clamping or, probably most of the times it is necessary, during delayed cord clamping with the cord still unclamped. Paired blood samples (one from the umbilical artery and one from the umbilical vein) can be taken from the pulsating and unclamped cord, immediately after birth, during delayed cord clamping, without any effect on either the accuracy of umbilical artery gas analysis or the transfusion of blood through delayed cord clamping. Umbilical artery gas analysis should instead not be done after delayed cord clamping, since delayed cord clamping alters several acid-based parameters and lactate values. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

  8. Is networking different with doctors working part-time? : Differences in social networks of part-time and full-time doctors

    NARCIS (Netherlands)

    Heiligers, Phil J.M.; Jong, Judith D. de; Groenewegen, Peter P.; Hingstman, Lammert; Völker, Beate; Spreeuwenberg, Peter

    2008-01-01

    Background: Part-time working is a growing phenomenon in medicine, which is expected to influence informal networks at work differently compared to full-time working. The opportunity to meet and build up social capital at work has offered a basis for theoretical arguments. Methods: Twenty-eight

  9. Is networking different with doctors working part-time? Differences in social networks of part-time and full-time doctors.

    NARCIS (Netherlands)

    Heiligers, P.J.M.; Groenewegen, P.P.; Jong, J.D. de; Hingstman, L.; Völker, B.; Spreeuwenberg, P.

    2008-01-01

    BACKGROUND: Part-time working is a growing phenomenon in medicine, which is expected to influence informal networks at work differently compared to full-time working. The opportunity to meet and build up social capital at work has offered a basis for theoretical arguments. METHODS: Twenty-eight

  10. Development of Automated Patch Clamp Technique to Investigate CFTR Chloride Channel Function.

    Science.gov (United States)

    Billet, Arnaud; Froux, Lionel; Hanrahan, John W; Becq, Frederic

    2017-01-01

    The chloride (Cl-) channel cystic fibrosis transmembrane conductance regulator (CFTR) is defective in cystic fibrosis (CF), and mutation of its encoding gene leads to various defects such as retention of the misfolded protein in the endoplasmic reticulum, reduced stability at the plasma membrane, abnormal channel gating with low open probability, and thermal instability, which leads to inactivation of the channel at physiological temperature. Pharmacotherapy is one major therapeutic approach in the CF field and needs sensible and fast tools to identify promising compounds. The high throughput screening assays available are often fast and sensible techniques but with lack of specificity. Few works used automated patch clamp (APC) for CFTR recording, and none have compared conventional and planar techniques and demonstrated their capabilities for different types of experiments. In this study, we evaluated the use of planar parallel APC technique for pharmacological search of CFTR-trafficking correctors and CFTR function modulators. Using optimized conditions, we recorded both wt- and corrected F508del-CFTR Cl- currents with automated whole-cell patch clamp and compared the data to results obtained with conventional manual whole-cell patch clamp. We found no significant difference in patch clamp parameters such as cell capacitance and series resistance between automated and manual patch clamp. Also, the results showed good similarities of CFTR currents recording between the two methods. We showed that similar stimulation protocols could be used in both manual and automatic techniques allowing precise control of temperature, classic I/V relationship, and monitoring of current stability in time. In conclusion, parallel patch-clamp recording allows rapid and efficient investigation of CFTR currents with a variety of tests available and could be considered as new tool for medium throughput screening in CF pharmacotherapy.

  11. Evaluation of partnership working in cities in phase IV of the WHO Healthy Cities Network.

    Science.gov (United States)

    Lipp, Alistair; Winters, Tim; de Leeuw, Evelyne

    2013-10-01

    An intersectoral partnership for health improvement is a requirement of the WHO European Healthy Cities Network of municipalities. A review was undertaken in 59 cities based on responses to a structured questionnaire covering phase IV of the network (2003-2008). Cities usually combined formal and informal working partnerships in a pattern seen in previous phases. However, these encompassed more sectors than previously and achieved greater degrees of collaborative planning and implementation. Additional WHO technical support and networking in phase IV significantly enhanced collaboration with the urban planning sector. Critical success factors were high-level political commitment and a well-organized Healthy City office. Partnerships remain a successful component of Healthy City working. The core principles, purpose and intellectual rationale for intersectoral partnerships remain valid and fit for purpose. This applied to long-established phase III cities as well as newcomers to phase IV. The network, and in particular the WHO brand, is well regarded and encourages political and organizational engagement and is a source of support and technical expertise. A key challenge is to apply a more rigorous analytical framework and theory-informed approach to reviewing partnership and collaboration parameters.

  12. The Dorsal Attention Network Reflects Both Encoding Load and Top-down Control during Working Memory.

    Science.gov (United States)

    Majerus, Steve; Péters, Frédéric; Bouffier, Marion; Cowan, Nelson; Phillips, Christophe

    2018-02-01

    The dorsal attention network is consistently involved in verbal and visual working memory (WM) tasks and has been associated with task-related, top-down control of attention. At the same time, WM capacity has been shown to depend on the amount of information that can be encoded in the focus of attention independently of top-down strategic control. We examined the role of the dorsal attention network in encoding load and top-down memory control during WM by manipulating encoding load and memory control requirements during a short-term probe recognition task for sequences of auditory (digits, letters) or visual (lines, unfamiliar faces) stimuli. Encoding load was manipulated by presenting sequences with small or large sets of memoranda while maintaining the amount of sensory stimuli constant. Top-down control was manipulated by instructing participants to passively maintain all stimuli or to selectively maintain stimuli from a predefined category. By using ROI and searchlight multivariate analysis strategies, we observed that the dorsal attention network encoded information for both load and control conditions in verbal and visuospatial modalities. Decoding of load conditions was in addition observed in modality-specific sensory cortices. These results highlight the complexity of the role of the dorsal attention network in WM by showing that this network supports both quantitative and qualitative aspects of attention during WM encoding, and this is in a partially modality-specific manner.

  13. Off-Clamp versus On-Clamp Robotic Partial Nephrectomy: A Multicenter Match-Paired Case-Control Study.

    Science.gov (United States)

    Peyronnet, Benoit; Khene, Zine-Eddine; Pradère, Benjamin; Seisen, Thomas; Verhoest, Grégory; Masson-Lecomte, Alexandra; Grassano, Yohann; Roumiguié, Mathieu; Beauval, Jean-Baptiste; Baumert, Hervé; Droupy, Stéphane; Doumerc, Nicolas; Bernhard, Jean-Christophe; Vaessen, Christophe; Bruyère, Franck; de la Taille, Alexandre; Rouprêt, Morgan; Bensalah, Karim

    2017-01-01

    The aim of this study was to compare the outcomes of on-clamp and off-clamp robotic partial nephrectomy (RPN). The charts of all patients who underwent an RPN at 8 institutions between 2010 and 2014 were retrospectively reviewed. The patients who underwent an off-clamp RPN were matched to on-clamp RPN in a 1-4 fashion according to the following variables: RENAL score, tumor size and surgeon's experience. Pre-, intra-, and postoperative data were compared between both groups. Among 525 RPN, 26 were performed off-clamp (5%). They were matched to 104 on-clamp RPN. The complications rate (15.5 vs. 7.7%, p = 0.53), major complications rate (4.9 vs. 3.9%; p = 0.82), and transfusions rate (0 vs. 4.9%; p = 0.58) did not differ significantly between the clamped and unclamped groups. Conversely, estimated blood loss was higher in the off-clamp group (266.4 vs. 284.6 mL, p = 0.048) and so was the rate of conversion to radical nephrectomy (0 vs. 7.7%, p = 0.04). Postoperative preservation of renal function was comparable in both groups. Off-clamp RPN is feasible for a small subgroup of renal tumors without increased risk of postoperative complications but at the cost of higher estimated blood loss and increased risk of conversion to radical nephrectomy. © 2017 S. Karger AG, Basel.

  14. Dental dam clamp adaptation method on carved gypsum cast

    Science.gov (United States)

    Cazacu, NCE

    2014-01-01

    Rationale. Dental Dam is the safest and most efficient isolation technique in endodontics and restorative dentistry, but it also used in esthetics, orthodontics, prosthetics, pedodontics and periodontology (for teeth immobilization). While in most cases the standard clamps are efficient, in some clinical situations clamp adaptation is mandatory in order to assure a tight contact on the tooth. Objective. The purpose of this study is to list the elements of the clamp, which should be modified in order to assure a secure constriction of the clamp on the anchor tooth, by using the carved gypsum cast method. Methods and Results. 100 patients were examined, diagnosed and treated for various diagnoses like simple decay, gangrene, chronic apical periodontitis, and endodontic retreatments. The clamps used in this study were produced by Hu-Friedy, Hygenic, KKD, SDI, Hager & Werken. In 10 cases, the anchor tooth did not provide enough stability to the standard clamp – as provided by the producer. Therefore, we have done some adjustments to some of the elements of the clamp: the arch, the wings, the plateau, the active area, and the contact points. In 6 cases, major clamp adaptations on carved gypsum cast were imperative. Discussion. The classic clamps cannot provide a grip to be enough in all the clinical cases due to the huge variety and position and implantation of the anchor teeth. Therefore, in such situations, the clamps should be adapted in order to provide stability and assure the safe isolation during the treatment. The modified clamps will be useful in similar cases, so they must be kept. PMID:25713609

  15. Applications of alcohol clamping in early drug development

    NARCIS (Netherlands)

    Zoethout, Remco Wiebe Martijn

    2012-01-01

    This thesis describes the development of a novel alcohol clamp, a new method to obtain stable plasma levels of alcohol and its application in CNS-research. The method might have several advantages that were explored in subsequent studies described in this thesis. The stability of the alcohol clamp

  16. The problem of isotropic rectangular plate with four clamped edges

    Indian Academy of Sciences (India)

    This report discusses in exact solution of the governing equation of an isotropic rectangular plate with four clamped edges. A numerical method for clamped isotropic rectangular plate under distributed loads and an exact solution of the governing equation in terms of trigonometric and hyperbolic function are given. Finally ...

  17. New active load voltage clamp for HF-link converters

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path...

  18. Laparoscopic off-clamp partial nephrectomy using soft coagulation.

    Science.gov (United States)

    Hongo, Fumiya; Kawauchi, Akihiro; Ueda, Takashi; Fujihara-Iwata, Atsuko; Nakamura, Terukazu; Naya, Yoshio; Kamoi, Kazumi; Okihara, Koji; Miki, Tsuneharu

    2015-08-01

    To assess the effectiveness of soft coagulation in off-clamp laparoscopic partial nephrectomy. A total of 32 patients with renal tumors underwent laparoscopic partial nephrectomy with off-clamp using soft coagulation between May 2012 and September 2013. Tumor resection was carried out using a combination of bipolar forceps and a ball electrode using the soft coagulation system without hilar clamping. The outcomes of these patients were compared with those of 30 patients treated with hilar clamping. This off-clamp procedure was successfully completed in 31 cases. No significant differences were observed in the mean age (60 vs 61 years), sex (male/female; 25/7 vs 20/10), mean RENAL nephrometry score (5.7 vs 5.8), mean body mass index (24.4 vs 23) or tumor size (15 mm vs 16 mm) between the two groups. No significant differences were noted in positive surgical margins (0 vs 0) or blood loss (104 vs 115 cc) as well. In contrast, a significant difference was noted in the total operative time (278 vs 238 min). Serum creatinine percentage changes at 3 months were 6.4 versus 7.3% in the off-clamp and hilum-clamp groups, respectively, which were not significantly different. Off-clamp laparoscopic partial nephrectomy can be safely carried out by using a soft coagulation technique. © 2015 The Japanese Urological Association.

  19. Advanced patch-clamp techniques and single-channel analysis

    NARCIS (Netherlands)

    Biskup, B; Elzenga, JTM; Homann, U; Thiel, G; Wissing, F; Maathuis, FJM

    Much of our knowledge of ion-transport mechanisms in plant cell membranes comes from experiments using voltage-clamp. This technique allows the measurement of ionic currents across the membrane, whilst the voltage is held under experimental control. The patch-clamp technique was developed to study

  20. Studying mechanosensitive ion channels with an automated patch clamp

    NARCIS (Netherlands)

    Barthmes, Maria; Jose, Mac Donald F; Birkner, Jan Peter; Brüggemann, Andrea; Wahl-Schott, Christian; Kocer, Armagan

    Patch clamp electrophysiology is the main technique to study mechanosensitive ion channels (MSCs), however, conventional patch clamping is laborious and success and output depends on the skills of the operator. Even though automated patch systems solve these problems for other ion channels, they

  1. Off-clamp robotic partial nephrectomy: Technique and outcome.

    Science.gov (United States)

    Lamoshi, Abdulraouf Y; Salkini, Mohamad W

    2015-01-01

    Robotic partial nephrectomy (RPN) is a technically challenging procedure. Advanced skills are needed to accomplish tumor resection, hemostasis, and renorrhaphy within short ischemia time in RPN. Off-clamp RPN with zero ischemia may decrease the risk of ischemic reperfusion injury to the kidney. However, the off-clamp technique has been associated with an increased risk of blood loss. The purpose of this study was to evaluate the outcome of our modified off-clamp technique utilized in certain RPN cases. A total of 81 patients underwent RPN between September 2009 and July 2013 for renal masses. We studied a subgroup of patients who underwent off-clamp RPN with zero ischemia time. The off-clamp technique was utilized for exophytic, nonhilar tumors that have a base of 2 cm or less. We developed a novel technique to avoid ischemia reperfusion renal injury while minimizing blood loss in certain cases of RPN. Of the 81 cases of RPN, we reviewed and adopted the off-clamp technique in 34 patients (41.98%). Utilizing off-clamp RPN resulted in an average blood loss of 96.29 ml and 1.56 days (range: 1-3 days) of hospital stay and minimal change in serum creatinine. Off-clamp RPN is safe and feasible approach to excise certain kidney tumors. It carries the benefits of RPN and prevents ischemia reperfusion renal injury.

  2. Connecting the Disconnected: Social Work and Social Network Analysis. A Methodological Approach to Identifying Network Peer Leaders

    Directory of Open Access Journals (Sweden)

    del Fresno García, Miguel

    2015-02-01

    Full Text Available Social network theory and analysis (SNA offers a useful conceptual framework and a robust set of methods for understanding, analysing, and representing the pattern of social interactions that surround individuals forming an overall network of ties. SNA provides both insights and applications regarding relational structures that may be consequential for individual and collective agency. Despite the fact that both SNA and social work focus on relationships and behaviour, and that each discipline could substantively inform the other, there remains a significant lack of intersection between the two disciplines. In response to this gap, SNA applied to social work can provide additional ways to both diagnose and intervene behaviourally through the following approaches: a by identifying key players in promoting the dissemination of behavioral changes in networks; b by segmenting and identifying groups, cliques and communities; c by supporting behavioural change through social ties surrounding the individual; and d by aligning and applying specific interventions that draw on mutually interactive processes in terms of individual influences on networks, as well as network influences on individuals. SNA provides social work with an additional lens and set of tools based on the constellation of interactions surrounding individuals, families, groups or communities that supports understanding, diagnosis, and intervention.La Teoría y Análisis de Redes Sociales (SNA ofrece un conjunto de métodos de análisis de las interacciones sociales de los seres humanos, que permiten de forma específica investigar las estructuras relacionales y la representación de éstas como redes. SNA proporciona tanto acceso a nuevo conocimiento como la representación de las estructuras relacionales y como éstas pueden ser consecuencia de la acción individual y colectiva. A pesar de que tanto el SNA como el Trabajo Social tienen su foco en las relaciones y el comportamiento, de

  3. Activity Clamp Provides Insights into Paradoxical Effects of the Anti-Seizure Drug Carbamazepine.

    Science.gov (United States)

    Morris, Gareth; Leite, Marco; Kullmann, Dimitri M; Pavlov, Ivan; Schorge, Stephanie; Lignani, Gabriele

    2017-05-31

    A major challenge in experimental epilepsy research is to reconcile the effects of anti-epileptic drugs (AEDs) on individual neurons with their network-level actions. Highlighting this difficulty, it is unclear why carbamazepine (CBZ), a frontline AED with a known molecular mechanism, has been reported to increase epileptiform activity in several clinical and experimental studies. We confirmed in an in vitro mouse model (in both sexes) that the frequency of interictal bursts increased after CBZ perfusion. To address the underlying mechanisms, we developed a method, activity clamp, to distinguish the response of individual neurons from network-level actions of CBZ. We first recorded barrages of synaptic conductances from neurons during epileptiform activity and then replayed them in pharmacologically isolated neurons under control conditions and in the presence of CBZ. CBZ consistently decreased the reliability of the second action potential in each burst of activity. Conventional current-clamp recordings using excitatory ramp or square-step current injections failed to reveal this effect. Network modeling showed that a CBZ-induced decrease of neuron recruitment during epileptic bursts can lead to an increase in burst frequency at the network level by reducing the refractoriness of excitatory transmission. By combining activity clamp with computer simulations, the present study provides a potential explanation for the paradoxical effects of CBZ on epileptiform activity.SIGNIFICANCE STATEMENT The effects of anti-epileptic drugs on individual neurons are difficult to separate from their network-level actions. Although carbamazepine (CBZ) has a known anti-epileptic mechanism, paradoxically, it has also been reported to increase epileptiform activity in clinical and experimental studies. To investigate this paradox during realistic neuronal epileptiform activity, we developed a method, activity clamp, to distinguish the effects of CBZ on individual neurons from network

  4. Circumferential hoof clamp method of lameness induction in the horse.

    Science.gov (United States)

    Swaab, M E; Mendez-Angulo, J L; Groschen, D M; Ernst, N S; Brown, M P; Trumble, T N

    2015-07-01

    A circumferential hoof clamp method to induce controlled and reversible lameness in the forelimbs of eight horses was assessed. Peak vertical forces and vertical impulses were recorded using a force plate to verify induced lameness. Video recordings were used by blinded observers to determine subjective lameness using a 0-5 scale and any residual lameness following clamp loosening. Tightening of clamps resulted in consistent, visible lameness in the selected limbs in all horses. Lameness was confirmed by significant decreases from baseline in the peak vertical force (P <0.01). Lameness was also confirmed subjectively by elevated median scores (0 at baseline and 2 during lameness). Lameness was not immediately reversible after clamp loosening (median score 1.5), but horses were not obviously lame after clamp removal and were no different from initial baseline (median score 0.5) approximately 3 days later. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Identification of promising Twin Hub networks : Report of Work Package 1 of the Intermodal rail freight Twin hub Network Northwest Europe - project (final report)

    NARCIS (Netherlands)

    Kreutzberger, E.D.; Konings, J.W.; Meijer, S.; Witteveen, C.; Meijers, B.M.; Pekin, E.; Macharis, C.; Kiel, J.; Kawabata, Y.; Vos, W.

    2014-01-01

    This report is the first deliverable of the project Intermodal Rail Freight Twin Hub Network Northwest Europe. We call its subject Twin hub network and the organisational entity to carry out the actions the Twin hub project. The project is funded by INTERREG NWE (programme IVb). Its work started in

  6. NOAA/NCEI/Regional Climate Services: Working with Partners and Stakeholders across a Wide Network

    Science.gov (United States)

    Mecray, E. L.

    2015-12-01

    Federal agencies all require plans to be prepared at the state level that outline the implementation of funding to address wildlife habitat, human health, transportation infrastructure, coastal zone management, environmental management, emergency management, and others. These plans are now requiring the consideration of changing climate conditions. So where does a state turn to discuss lessons learned, obtain tools and information to assess climate conditions, and to work with other states in their region? Regional networks and collaboratives are working to deliver this sector by sector. How do these networks work? Do they fit together in any way? What similarities and differences exist? Is anyone talking across these lines to find common climate information requirements? A sketch is forming that links these efforts, not by blending the sectors, but by finding the areas where coordination is critical, where information needs are common, and where delivery mechanisms can be streamlined. NOAA/National Centers for Environmental Information's Regional Climate Services Directors have been working at the interface of stakeholder-driven information delivery since 2010. This talk will outline the regional climate services delivery framework for the Eastern Region, with examples of regional products and information.

  7. Randomized clinical trial of BiClamp forceps versus clamp-crushing technique in open liver resection.

    Science.gov (United States)

    Chen, Jiang Ming; Geng, Wei; Zhang, Song; Liu, Fu Bao; Zhao, Hong Chuan; Zhao, Yi Jun; Wang, Guo Bin; Xie, Sheng Xue; Geng, Xiao Ping

    2017-03-01

    The aim of this trial was to compare the efficacy and safety of BiClamp forceps with the "gold-standard" clamp-crushing technique for open liver resection. From October 2014 to May 2016, 86 consecutive patients scheduled to undergo hepatic resection were randomized to a BiClamp forceps group (n = 43) or to a clamp-crushing technique group (n = 43). Background characteristics of the two groups were closely matched. There were no significant differences between the BiClamp forceps group and clamp-crushing group in total intraoperative blood loss (339.81 ± 257.20 ml vs. 376.73 ± 303.67 ml, respectively; P = 0.545) or blood loss per transection area (5.35 ± 3.27 ml/cm2 vs. 5.44 ± 3.02 ml/cm2 , respectively; P = 0.609). Liver transection speed, the need of blood transfusion, morbidity, length of postoperative hospital stay, total hospitalization cost and liver function recovery were similar in the two groups. Multivariate logistic regression analysis identified major hepatectomy, multiple resections and liver transection time ≥30 min as significantly unfavorable factors for decreased intraoperative blood loss. Liver parenchymal transection with BiClamp forceps is as safe and feasible as the gold-standard clamp-crushing technique. © 2017 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  8. Working memory impairment in fibromyalgia patients associated with altered frontoparietal memory network.

    Directory of Open Access Journals (Sweden)

    Jeehye Seo

    Full Text Available BACKGROUND: Fibromyalgia (FM is a disorder characterized by chronic widespread pain and frequently associated with other symptoms. Patients with FM commonly report cognitive complaints, including memory problem. The objective of this study was to investigate the differences in neural correlates of working memory between FM patients and healthy subjects, using functional magnetic resonance imaging (MRI. METHODOLOGY/PRINCIPAL FINDINGS: Nineteen FM patients and 22 healthy subjects performed an n-back memory task during MRI scan. Functional MRI data were analyzed using within- and between-group analysis. Both activated and deactivated brain regions during n-back task were evaluated. In addition, to investigate the possible effect of depression and anxiety, group analysis was also performed with depression and anxiety level in terms of Beck depression inventory (BDI and Beck anxiety inventory (BAI as a covariate. Between-group analyses, after controlling for depression and anxiety level, revealed that within the working memory network, inferior parietal cortex was strongly associated with the mild (r = 0.309, P = 0.049 and moderate (r = 0.331, P = 0.034 pain ratings. In addition, between-group comparison revealed that within the working memory network, the left DLPFC, right VLPFC, and right inferior parietal cortex were associated with the rating of depression and anxiety? CONCLUSIONS/SIGNIFICANCE: Our results suggest that the working memory deficit found in FM patients may be attributable to differences in neural activation of the frontoparietal memory network and may result from both pain itself and depression and anxiety associated with pain.

  9. Combining network analysis with Cognitive Work Analysis: insights into social organisational and cooperation analysis.

    Science.gov (United States)

    Houghton, Robert J; Baber, Chris; Stanton, Neville A; Jenkins, Daniel P; Revell, Kirsten

    2015-01-01

    Cognitive Work Analysis (CWA) allows complex, sociotechnical systems to be explored in terms of their potential configurations. However, CWA does not explicitly analyse the manner in which person-to-person communication is performed in these configurations. Consequently, the combination of CWA with Social Network Analysis provides a means by which CWA output can be analysed to consider communication structure. The approach is illustrated through a case study of a military planning team. The case study shows how actor-to-actor and actor-to-function mapping can be analysed, in terms of centrality, to produce metrics of system structure under different operating conditions. In this paper, a technique for building social network diagrams from CWA is demonstrated.The approach allows analysts to appreciate the potential impact of organisational structure on a command system.

  10. Inefficient preparatory fMRI-BOLD network activations predict working memory dysfunctions in patients with schizophrenia

    Directory of Open Access Journals (Sweden)

    Anja eBaenninger

    2016-03-01

    Full Text Available Patients with schizophrenia show abnormal dynamics and structure of temporally coherent networks (TCNs assessed using fMRI, which undergo adaptive shifts in preparation for a cognitively demanding task. During working memory (WM tasks, patients with schizophrenia show persistent deficits in TCNs as well as EEG indices of WM. Studying their temporal relationship during WM tasks might provide novel insights into WM performance deficits seen in schizophrenia.Simultaneous EEG-fMRI data were acquired during the performance of a verbal Sternberg WM task with two load levels (load 2 & load 5 in 17 patients with schizophrenia and 17 matched healthy controls. Using covariance mapping, we investigated the relationship of the activity in the TCNs before the memoranda were encoded and EEG spectral power during the retention interval. We assessed four TCNs – default mode network (DMN, dorsal attention network (dAN, left and right working memory networks (WMNs – and three EEG bands – theta, alpha, and beta.In healthy controls, there was a load dependent inverse relation between DMN and frontal-midline theta power and an anti-correlation between DMN and dAN. Both effects were not significantly detectable in patients. In addition, healthy controls showed a left-lateralized load-dependent recruitment of the WMNs. Activation of the WMNs was bilateral in patients, suggesting more resources were recruited for successful performance on the WM task.Our findings support the notion of schizophrenia patients showing deviations in their neurophysiological responses before the retention of relevant information in a verbal WM task. Thus, treatment strategies as neurofeedback targeting pre-states could be beneficial as task performance relies on the preparatory state of the brain.

  11. Pre-stimulus BOLD-network activation modulates EEG spectral activity during working memory retention

    Directory of Open Access Journals (Sweden)

    Mara eKottlow

    2015-05-01

    Full Text Available Working memory (WM processes depend on our momentary mental state and therefore exhibit considerable fluctuations. Here, we investigate the interplay of task-preparatory and task-related brain activity as represented by pre-stimulus BOLD-fluctuations and spectral EEG from the retention periods of a visual WM task. Visual WM is used to maintain sensory information in the brain enabling the performance of cognitive operations and is associated with mental health.We tested 22 subjects simultaneously with EEG and fMRI while performing a visuo-verbal Sternberg task with two different loads, allowing for the temporal separation of preparation, encoding, retention and retrieval periods.Four temporally coherent networks - the default mode network (DMN, the dorsal attention, the right and the left WM network - were extracted from the continuous BOLD data by means of a group ICA. Subsequently, the modulatory effect of these networks’ pre-stimulus activation upon retention-related EEG activity in the theta, alpha and beta frequencies was analyzed. The obtained results are informative in the context of state-dependent information processing.We were able to replicate two well-known load-dependent effects: the frontal-midline theta increase during the task and the decrease of pre-stimulus DMN activity. As our main finding, these two measures seem to depend on each other as the significant negative correlations at frontal-midline channels suggested. Thus, suppressed pre-stimulus DMN levels facilitated later task related frontal midline theta increases. In general, based on previous findings that neuronal coupling in different frequency bands may underlie distinct functions in WM retention, our results suggest that processes reflected by spectral oscillations during retention seem not only to be online synchronized with activity in different attention-related networks but are also modulated by activity in these networks during preparation intervals.

  12. Life, Work and Sustainable Learning Practices: A Study on a Small Business Network

    Directory of Open Access Journals (Sweden)

    Ana Silvia Rocha Ipiranga

    2014-04-01

    Full Text Available Knowledge and knowing processes as work and life practices are not univocal. They are not related to knowledge as an autonomous body of propositions, but permeated with new identities and action modes, which are continuously formed, promoting learning opportunities. The objective of this research is formulated in the understanding of this shift between knowing and knowledge when describing practical learning in everyday work life, reflecting on the implications of this social labor process on small business network sustainability. A qualitative case study approach was used. In line with the theoretical and epistemological choices that guided this research, we decided to use an analysis of discursive practices approach and, accordingly, data collection was based on triangulation techniques in favor of interpretation enrichment. The knowledge to act, revealed in the analysis, suggested that organizations are social worlds forming a standard that holds life, work and organizational practices together. They negotiate, circulate, transform and reproduce, forming a network of actors and favoring sustainable practices learning.

  13. Training Working Memory in Childhood Enhances Coupling between Frontoparietal Control Network and Task-Related Regions.

    Science.gov (United States)

    Barnes, Jessica J; Nobre, Anna Christina; Woolrich, Mark W; Baker, Kate; Astle, Duncan E

    2016-08-24

    Working memory is a capacity upon which many everyday tasks depend and which constrains a child's educational progress. We show that a child's working memory can be significantly enhanced by intensive computer-based training, relative to a placebo control intervention, in terms of both standardized assessments of working memory and performance on a working memory task performed in a magnetoencephalography scanner. Neurophysiologically, we identified significantly increased cross-frequency phase amplitude coupling in children who completed training. Following training, the coupling between the upper alpha rhythm (at 16 Hz), recorded in superior frontal and parietal cortex, became significantly coupled with high gamma activity (at ∼90 Hz) in inferior temporal cortex. This altered neural network activity associated with cognitive skill enhancement is consistent with a framework in which slower cortical rhythms enable the dynamic regulation of higher-frequency oscillatory activity related to task-related cognitive processes. Whether we can enhance cognitive abilities through intensive training is one of the most controversial topics of cognitive psychology in recent years. This is particularly controversial in childhood, where aspects of cognition, such as working memory, are closely related to school success and are implicated in numerous developmental disorders. We provide the first neurophysiological account of how working memory training may enhance ability in childhood, using a brain recording technique called magnetoencephalography. We borrowed an analysis approach previously used with intracranial recordings in adults, or more typically in other animal models, called "phase amplitude coupling." Copyright © 2016 Barnes et al.

  14. Using Bayesian networks to analyze occupational stress caused by work demands: preventing stress through social support.

    Science.gov (United States)

    García-Herrero, Susana; Mariscal, M A; Gutiérrez, J M; Ritzel, Dale O

    2013-08-01

    Occupational stress is a major health hazard and a serious challenge to the effective operation of any company and represents a major problem for both individuals and organizations. Previous researches have shown that high demands (e.g. workload, emotional) combined with low resources (e.g. support, control, rewards) are associated with adverse health (e.g. psychological, physical) and organizational impacts (e.g. reduced job satisfaction, sickness absence). The objective of the present work is to create a model to analyze how social support reduces the occupational stress caused by work demands. This study used existing Spanish national data on working conditions collected by the Spanish Ministry of Labour and Immigration in 2007, where 11,054 workers were interviewed by questionnaire. A probabilistic model was built using Bayesian networks to explain the relationships between work demands and occupational stress. The model also explains how social support contributes positively to reducing stress levels. The variables studied were intellectually demanding work, overwork, workday, stress, and social support. The results show the importance of social support and of receiving help from supervisors and co-workers in preventing occupational stress. The study provides a new methodology that explains and quantifies the effects of intellectually demanding work, overwork, and workday in occupational stress. Also, the study quantifies the importance of social support to reduce occupational stress. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Is "Delayed Umbilical Cord Clamping" Beneficial for Premature Newborns?

    Directory of Open Access Journals (Sweden)

    Amir-Mohammad Armanian

    2017-05-01

    Full Text Available Background: The appropriate moment for clamping the umbilical cord is controversial. Immediate cord clamping (ICC is an item of active management of the third stage of labor (AMTSL. Unclamped umbilical cord may cause inconvenience in preterm neonates because they commonly need some levels of emergent services. Some studies revealed delayed cord clamping (DCC of preterm neonates results in better health conditions like lower rates of respiratory distress syndrome (RDS, less morbidities in labor room and lower risk of postpartum hemorrhage. The aim of the present study was to determine the effect of delayed umbilical cord clamping on premature neonatal outcomes. Materials and Methods: In this single‑center randomized control trial study, sixty premature neonates (gestational age ≤ 34 weeks were randomly assigned to ICC (cord clamped at 5–10 seconds or DCC (30–45 seconds groups and followed up in neonatal intensive care unit (NICU. Primary outcomes were 1st and 5th minute Apgar score, average of level of hematocrit after birth, intra ventricle hemorrhage and need some levels of resuscitation. Results: Differences in demographic characteristics were not statistically significant. After birth, neonates who had delayed clamping had significantly higher mean hematocrit after at 4-hour of birth (49.58+5.15gr/dl vs. 46.58+5.40gr/dlin DCC vs. ICC groups, respectively (P=0.031. Delayed cord clamping reduced the duration of need to nasal continues positive airway pressure (NCPAP (86.7% and 60.0% in ICC and DCC groups, respectively, P= 0.039. Attractively, the results showed lower incidence of clinical sepsis in delayed cord clamping neonates (53.3% vs. 23.3% in ICC and DCC groups, respectively, P=0.033. Conclusion: Prematurity complications might decrease by delay umbilical cord clamping which improve the hematocrit, duration of need to NCPAP and incidence of clinical sepsis. Furthermore, DCC may have no negative impact on neonatal resuscitation.

  16. [Modern networks : Topics in the working group "Bladder cancer research" of the GeSRU Academics].

    Science.gov (United States)

    Hofbauer, S; Kalogirou, C; Roghmann, F; Seitz, A-K; Vallo, S; Wezel, F; Worst, T; Nawroth, R

    2017-02-01

    In January 2015, the research group "bladder cancer research" was founded as part of the GeSRU Academics research initiative. A general challenge to work successfully in a novel network structure is to identify common scientific topics and technical expertise in the group. Thus, one of the first tasks was to learn about current research projects from members within the group in order to address a project that suits the group's expertise. The following review summarizes three different directions that are key projects in Urologic Departments at German Universities that will be the basis to start fruitful collaborations.

  17. Fronto-parietal network oscillations reveal relationship between working memory capacity and cognitive control

    Directory of Open Access Journals (Sweden)

    Rasa eGulbinaite

    2014-09-01

    Full Text Available Executive-attention theory proposes a close relationship between working memory capacity (WMC and cognitive control abilities. However, conflicting results are documented in the literature, with some studies reporting that individual variations in WMC predict differences in cognitive control and trial-to-trial control adjustments (operationalized as the size of the congruency effect and congruency sequence effects, respectively, while others report no WMC-related differences. We hypothesized that brain network dynamics might be a more sensitive measure of WMC-related differences in cognitive control abilities. Thus, in the present study, we measured human EEG during the Simon task to characterize WMC-related differences in the neural dynamics of conflict processing and adaptation to conflict. Although high- and low-WMC individuals did not differ behaviorally, there were substantial WMC-related differences in theta (4-8 Hz and delta (1-3 Hz connectivity in fronto-parietal networks. Group differences in local theta and delta power were relatively less pronounced. These results suggest that the relationship between WMC and cognitive control abilities is more strongly reflected in large-scale oscillatory network dynamics than in spatially localized activity or in behavioral task performance.

  18. Fronto-parietal network oscillations reveal relationship between working memory capacity and cognitive control.

    Science.gov (United States)

    Gulbinaite, Rasa; van Rijn, Hedderik; Cohen, Michael X

    2014-01-01

    Executive-attention theory proposes a close relationship between working memory capacity (WMC) and cognitive control abilities. However, conflicting results are documented in the literature, with some studies reporting that individual variations in WMC predict differences in cognitive control and trial-to-trial control adjustments (operationalized as the size of the congruency effect and congruency sequence effects, respectively), while others report no WMC-related differences. We hypothesized that brain network dynamics might be a more sensitive measure of WMC-related differences in cognitive control abilities. Thus, in the present study, we measured human EEG during the Simon task to characterize WMC-related differences in the neural dynamics of conflict processing and adaptation to conflict. Although high- and low-WMC individuals did not differ behaviorally, there were substantial WMC-related differences in theta (4-8 Hz) and delta (1-3 Hz) connectivity in fronto-parietal networks. Group differences in local theta and delta power were relatively less pronounced. These results suggest that the relationship between WMC and cognitive control abilities is more strongly reflected in large-scale oscillatory network dynamics than in spatially localized activity or in behavioral task performance.

  19. Robust working memory in an asynchronously spiking neural network realized in neuromorphic VLSI

    Directory of Open Access Journals (Sweden)

    Massimiliano eGiulioni

    2012-02-01

    Full Text Available We demonstrate bistable attractor dynamics in a spiking neural network implemented with neuromorphic VLSI hardware. The on-chip network consists of three interacting populations (two excitatory, one inhibitory of integrate-and-fire (LIF neurons. One excitatory population is distinguished by strong synaptic self-excitation, which sustains meta-stable states of ‘high’ and ‘low’-firing activity. Depending on the overall excitability, transitions to the ‘high’ state may be evoked by external stimulation, or may occur spontaneously due to random activity fluctuations. In the former case, the ‘high’ state retains a working memory of a stimulus until well after its release. In the latter case, ‘high’ states remain stable for seconds, three orders of magnitude longer than the largest time-scale implemented in the circuitry. Evoked and spontaneous transitions form a continuum and may exhibit a wide range of latencies, depending on the strength of external stimulation and of recurrent synaptic excitation. In addition, we investigated corrupted ‘high’ states comprising neurons of both excitatory populations. Within a basin of attraction, the network dynamics corrects such states and re-establishes the prototypical ‘high’ state. We conclude that, with effective theoretical guidance, full-fledged attractor dynamics can be realized with comparatively small populations of neuromorphic hardware neurons.

  20. Emotion perception and executive control interact in the salience network during emotionally charged working memory processing.

    Science.gov (United States)

    Luo, Yu; Qin, Shaozheng; Fernández, Guillén; Zhang, Yu; Klumpers, Floris; Li, Hong

    2014-11-01

    Processing of emotional stimuli can either hinder or facilitate ongoing working memory (WM); however, the neural basis of these effects remains largely unknown. Here we examined the neural mechanisms of these paradoxical effects by implementing a novel emotional WM task in an fMRI study. Twenty-five young healthy participants performed an N-back task with fearful and neutral faces as stimuli. Participants made more errors when performing 0-back task with fearful versus neutral faces, whereas they made fewer errors when performing 2-back task with fearful versus neutral faces. These emotional impairment and enhancement on behavioral performance paralleled significant interactions in distributed regions in the salience network including anterior insula (AI) and dorsal cingulate cortex (dACC), as well as in emotion perception network including amygdala and temporal-occipital association cortex (TOC). The dorsal AI (dAI) and dACC were more activated when comparing fearful with neutral faces in 0-back task. Contrarily, dAI showed reduced activation, while TOC and amygdala showed stronger responses to fearful as compared to neutral faces in the 2-back task. These findings provide direct neural evidence to the emerging dual competition model suggesting that the salience network plays a critical role in mediating interaction between emotion perception and executive control when facing ever-changing behavioral demands. Copyright © 2014 Wiley Periodicals, Inc.

  1. Requirements to gap widths and clamping for CO2 laser butt welding

    DEFF Research Database (Denmark)

    Gong, Hui; Juhl, Thomas Winther

    1999-01-01

    In the experimental study of fixturing and gap width requirements a clamping device for laser butt welding of steel sheets has been developed and tested. It has fulfilled the work and made the gap width experiments possible.It has shown that the maximum allowable gap width to some extent is inver......In the experimental study of fixturing and gap width requirements a clamping device for laser butt welding of steel sheets has been developed and tested. It has fulfilled the work and made the gap width experiments possible.It has shown that the maximum allowable gap width to some extent....../min 2.6 kWThe quality level is measured according to ISO 13919-1. Qualities of the butt welds with the maximum gap width listed in the table are mainly grouped in level B (stringent). The maximum gap width should be chosen with respect to the application requirements....

  2. Learning network theory : its contribution to our understanding of work-based learning projects and learning climate

    NARCIS (Netherlands)

    Poell, R.F.; Moorsel, M.A.A.H. van

    1996-01-01

    This paper discusses the relevance of Van der Krogt's learning network theory (1995) for our understanding of the concepts of work-related learning projects and learning climate in organisations. The main assumptions of the learning network theory are presented and transferred to the level of

  3. A Learning Network as a Development Method--An Example of Small Enterprises and a University Working Together.

    Science.gov (United States)

    Tell, Joakim; Halila, Fawzi

    2001-01-01

    Small businesses implementing ISO 14001 standards worked with a university to develop a learning network. The network served as a source of inspiration and reflection as well as a sounding board. It enabled small enterprises to act collectively, compensating for individual lack of resources. (SK)

  4. Interaction of multiple networks modulated by the working memory training based on real-time fMRI

    Science.gov (United States)

    Shen, Jiahui; Zhang, Gaoyan; Zhu, Chaozhe; Yao, Li; Zhao, Xiaojie

    2015-03-01

    Neuroimaging studies of working memory training have identified the alteration of brain activity as well as the regional interactions within the functional networks such as central executive network (CEN) and default mode network (DMN). However, how the interaction within and between these multiple networks is modulated by the training remains unclear. In this paper, we examined the interaction of three training-induced brain networks during working memory training based on real-time functional magnetic resonance imaging (rtfMRI). Thirty subjects assigned to the experimental and control group respectively participated in two times training separated by seven days. Three networks including silence network (SN), CEN and DMN were identified by the training data with the calculated function connections within each network. Structural equation modeling (SEM) approach was used to construct the directional connectivity patterns. The results showed that the causal influences from the percent signal changes of target ROI to the SN were positively changed in both two groups, as well as the causal influence from the SN to CEN was positively changed in experimental group but negatively changed in control group from the SN to DMN. Further correlation analysis of the changes in each network with the behavioral improvements showed that the changes in SN were stronger positively correlated with the behavioral improvement of letter memory task. These findings indicated that the SN was not only a switch between the target ROI and the other networks in the feedback training but also an essential factor to the behavioral improvement.

  5. Reciprocating clamp apparatus for thermoforming plastic containers

    Energy Technology Data Exchange (ETDEWEB)

    Beck, M.H.; Harry, I.L.; Krishnakumar, S.M.

    1984-03-06

    This relates to the forming of containers and like hollow articles from sheets or webs of thermoplastic material. Two webs or sheets are simultaneously acted upon by way of a forming apparatus which includes a reciprocating clamp first cooperable with one outer platen and then the other in sequence wherein, while a first web or sheet is being formed within a plurality of mold cavities to define a plurality of hollow articles such as containers, the other sheet or web may be stripped from its respective mold set and a new sheet or a new portion of a sheet or web may be advanced into position for molding. The forming apparatus may be constructed in a manner wherein the web portions which are to be formed may be billowed away from the mold cavities as an initial step in the stretching and orientation of the thermoplastic material. The thermoplastic material may be heated to the desired forming temperature using separate sets of rf electrodes so that only those portions of the thermoplastic material which are to be formed need be heated. Two sets of containers of different sizes may be formed from the webs or sheets, and then internested to form double wall containers wherein the walls may be formed of different materials and wherein the outer material may be a barrier material, or wherein the walls of the containers are spaced apart to form an insulated container. This abstract forms no part of the specification of this application and is not to be construed as limiting the claims of the application.

  6. Serotonergic modulation of spatial working memory: predictions from a computational network model

    Directory of Open Access Journals (Sweden)

    Maria eCano-Colino

    2013-09-01

    Full Text Available Serotonin (5-HT receptors of types 1A and 2A are massively expressed in prefrontal cortex (PFC neurons, an area associated with cognitive function. Hence, 5-HT could be effective in modulating prefrontal-dependent cognitive functions, such as spatial working memory (SWM. However, a direct association between 5-HT and SWM has proved elusive in psycho-pharmacological studies. Recently, a computational network model of the PFC microcircuit was used to explore the relationship between 5‑HT and SWM (Cano-Colino et al. 2013. This study found that both excessive and insufficient 5-HT levels lead to impaired SWM performance in the network, and it concluded that analyzing behavioral responses based on confidence reports could facilitate the experimental identification of SWM behavioral effects of 5‑HT neuromodulation. Such analyses may have confounds based on our limited understanding of metacognitive processes. Here, we extend these results by deriving three additional predictions from the model that do not rely on confidence reports. Firstly, only excessive levels of 5-HT should result in SWM deficits that increase with delay duration. Secondly, excessive 5-HT baseline concentration makes the network vulnerable to distractors at distances that were robust to distraction in control conditions, while the network still ignores distractors efficiently for low 5‑HT levels that impair SWM. Finally, 5-HT modulates neuronal memory fields in neurophysiological experiments: Neurons should be better tuned to the cued stimulus than to the behavioral report for excessive 5-HT levels, while the reverse should happen for low 5-HT concentrations. In all our simulations agonists of 5-HT1A receptors and antagonists of 5-HT2A receptors produced behavioral and physiological effects in line with global 5-HT level increases. Our model makes specific predictions to be tested experimentally and advance our understanding of the neural basis of SWM and its neuromodulation

  7. Decreased efficiency of task-positive and task-negative networks during working memory in schizophrenia.

    Science.gov (United States)

    Metzak, Paul D; Riley, Jennifer D; Wang, Liang; Whitman, Jennifer C; Ngan, Elton T C; Woodward, Todd S

    2012-06-01

    Working memory (WM) is one of the most impaired cognitive processes in schizophrenia. Functional magnetic resonance imaging (fMRI) studies in this area have typically found a reduction in information processing efficiency but have focused on the dorsolateral prefrontal cortex. In the current study using the Sternberg Item Recognition Test, we consider networks of regions supporting WM and measure the activation of functionally connected neural networks over different WM load conditions. We used constrained principal component analysis with a finite impulse response basis set to compare the estimated hemodynamic response associated with different WM load condition for 15 healthy control subjects and 15 schizophrenia patients. Three components emerged, reflecting activated (task-positive) and deactivated (task-negative or default-mode) neural networks. Two of the components (with both task-positive and task-negative aspects) were load dependent, were involved in encoding and delay phases (one exclusively encoding and the other both encoding and delay), and both showed evidence for decreased efficiency in patients. The results suggest that WM capacity is reached sooner for schizophrenia patients as the overt levels of WM load increase, to the point that further increases in overt memory load do not increase fMRI activation, and lead to performance impairments. These results are consistent with an account holding that patients show reduced efficiency in task-positive and task-negative networks during WM and also partially support the shifted inverted-U-shaped curve theory of the relationship between WM load and fMRI activation in schizophrenia.

  8. An accurate online calibration system based on combined clamp-shape coil for high voltage electronic current transformers.

    Science.gov (United States)

    Li, Zhen-hua; Li, Hong-bin; Zhang, Zhi

    2013-07-01

    Electronic transformers are widely used in power systems because of their wide bandwidth and good transient performance. However, as an emerging technology, the failure rate of electronic transformers is higher than that of traditional transformers. As a result, the calibration period needs to be shortened. Traditional calibration methods require the power of transmission line be cut off, which results in complicated operation and power off loss. This paper proposes an online calibration system which can calibrate electronic current transformers without power off. In this work, the high accuracy standard current transformer and online operation method are the key techniques. Based on the clamp-shape iron-core coil and clamp-shape air-core coil, a combined clamp-shape coil is designed as the standard current transformer. By analyzing the output characteristics of the two coils, the combined clamp-shape coil can achieve verification of the accuracy. So the accuracy of the online calibration system can be guaranteed. Moreover, by employing the earth potential working method and using two insulating rods to connect the combined clamp-shape coil to the high voltage bus, the operation becomes simple and safe. Tests in China National Center for High Voltage Measurement and field experiments show that the proposed system has a high accuracy of up to 0.05 class.

  9. Consciousness and the prefrontal parietal network: Insights from attention, working memory and chunking

    Directory of Open Access Journals (Sweden)

    Daniel eBor

    2012-03-01

    Full Text Available Consciousness has of late become a hot topic in neuroscience. Empirical work has centred on identifying potential neural correlates of consciousness (NCCs, with a converging view that the prefrontal parietal network (PPN is closely associated with this process. Theoretical work has primarily sought to explain how informational properties of this cortical network could account for phenomenal properties of consciousness. However, both empirical and theoretical research has given less focus to the psychological features that may account for the NCCs. The PPN has also been heavily linked with cognitive processes, such as attention. We describe how this literature is under-appreciated in consciousness science, in part due to the increasingly entrenched assumption of a strong dissociation between attention and consciousness. We argue instead that there is more common ground between attention and consciousness than is usually emphasized: although objects can under certain circumstances be attended to in the absence of conscious access, attention as a content selection and boosting mechanism is an important and necessary aspect of consciousness. Like attention, working memory and executive control involve the interlinking of multiple mental objects and have also been closely associated with the PPN. We propose that this set of cognitive functions, in concert with attention, make up the core psychological components of consciousness. One related process, chunking, has been shown to activate PPN particularly robustly, even compared with other cognitively demanding tasks, such as working memory or mental arithmetic. It is therefore possible that chunking, as a tool to detect useful patterns within an integrated set of intensely processed (attended information, has a central role to play in consciousness. Following on from this, we suggest that the main evolutionary purpose of consciousness may be to provide innovative solutions to complex or novel problems.

  10. Consciousness and the prefrontal parietal network: insights from attention, working memory, and chunking.

    Science.gov (United States)

    Bor, Daniel; Seth, Anil K

    2012-01-01

    Consciousness has of late become a "hot topic" in neuroscience. Empirical work has centered on identifying potential neural correlates of consciousness (NCCs), with a converging view that the prefrontal parietal network (PPN) is closely associated with this process. Theoretical work has primarily sought to explain how informational properties of this cortical network could account for phenomenal properties of consciousness. However, both empirical and theoretical research has given less focus to the psychological features that may account for the NCCs. The PPN has also been heavily linked with cognitive processes, such as attention. We describe how this literature is under-appreciated in consciousness science, in part due to the increasingly entrenched assumption of a strong dissociation between attention and consciousness. We argue instead that there is more common ground between attention and consciousness than is usually emphasized: although objects can under certain circumstances be attended to in the absence of conscious access, attention as a content selection and boosting mechanism is an important and necessary aspect of consciousness. Like attention, working memory and executive control involve the interlinking of multiple mental objects and have also been closely associated with the PPN. We propose that this set of cognitive functions, in concert with attention, make up the core psychological components of consciousness. One related process, chunking, exploits logical or mnemonic redundancies in a dataset so that it can be recoded and a given task optimized. Chunking has been shown to activate PPN particularly robustly, even compared with other cognitively demanding tasks, such as working memory or mental arithmetic. It is therefore possible that chunking, as a tool to detect useful patterns within an integrated set of intensely processed (attended) information, has a central role to play in consciousness. Following on from this, we suggest that a key

  11. Dynamic Study of a Capacitive MEMS Switch with Double Clamped-Clamped Microbeams

    Directory of Open Access Journals (Sweden)

    Hatem Samaali

    2014-01-01

    Full Text Available We study a capacitive MEMS switch composed of two clamped-clamped exible microbeams. We first develop a mathematical model for the MEMS switch where the upper microbeam represents the ground transmission line and the lower one represents the central transmission line. An electrostatic force is applied between the two microbeams to yield the switch to its ON and OFF states. We derive the equations of motion of the system and associated boundary conditions and solve the static and dynamic problems using the differential quadratic method. We show that using only nine grid points gives relatively accurate results when compared to those obtained using FEM. We also examine the transient behavior of the microswitch and obtain results indicating that subsequent reduction in actuation voltage, switching time, and power consumption are expected along with relatively good RF performances. ANSYS HFSS simulator is used in this paper to extract the RF characteristics of the microswitch. HFSS simulation results show that the insertion loss is as low as −0.31 dB and that the return loss is better than −12.41 dB at 10 GHz in the ON state. At the OFF state, the isolation is lower than −23 dB in the range of 10 to 50 GHz.

  12. Learning network theory : its contribution to our understanding of work-based learning projects and learning climate

    OpenAIRE

    Poell, R.F.; Moorsel, M.A.A.H. van

    1996-01-01

    This paper discusses the relevance of Van der Krogt's learning network theory (1995) for our understanding of the concepts of work-related learning projects and learning climate in organisations. The main assumptions of the learning network theory are presented and transferred to the level of learning groups in organisations. Four theoretical types of learning projects are distinguished. Four different approaches to the learning climate of work groups are compared to the approach offered by t...

  13. Comparison of drain clamp after bilateral total knee arthroplasty.

    Science.gov (United States)

    Madadi, Firooz; Mehrvarz, Amir Sarshekeh; Madadi, Firoozeh; Boreiri, Majid; Abachizadeh, Kambiz; Ershadi, Ali

    2010-12-01

    Suction drains provide an easy and feasible method for controlling hemorrhage after total knee arthroplasty. However, there has been no compromise regarding the optimum clamping time for these drains. We conducted a randomized clinical trial in 50 patients to compare 12-hour drain clamping and continuous drainage after total knee arthroplasty in terms of wound complications, blood loss, and articular arc of motion. To eliminate any other factor except duration of clamping, we chose to compare only knees belonging to a single patient and to restrict the study to those knees undergoing surgery due to osteoarthritis. From a total of 100 knees (50 patients) studied, the 12-hour-clamping method resulted in a significantly smaller amount of postoperative blood loss (p < 0.001). The passive ranges of motion and wound complications were not significantly different between the two groups.

  14. Lotus birth, a holistic approach on physiological cord clamping.

    Science.gov (United States)

    Zinsser, Laura A

    2017-09-04

    The positive effects of delayed cord clamping (DCC) has been extensively researched. DCC means: waiting at least one minute after birth before clamping and cutting the cord or till the pulsation has stopped. With physiological clamping and cutting (PCC) the clamping and cutting can happen at the earliest after the pulsation has stopped. With a Lotus birth, no clamping and cutting of the cord is done. A woman called Clair Lotus Day imitated the holistic approach of PCC from an anthropoid ape in 1974. The chimpanzee did not separate the placenta from the newborn. The aim of this case report is to discuss and learn a different approach in the third stage of labour. Three cases of Lotus birth by human beings were observed. All three women gave birth in an out-of-hospital setting and had ambulant postnatal care. The placenta was washed, salted and herbs were put on 2-3h post partum. The placenta was wrapped in something that absorbs the moisture. The salting was repeated with a degreasing frequency depending on moistness of the placenta. On life day six all three Lotus babies experiences a natural separation of the cord. All three Lotus birth cases were unproblematic, no special incidence occurred. One should differentiate between early cord clamping (ECC), delayed cord clamping (DCC) and physiological cord clamping (PCC). Lotus birth might lead to an optimisation of the bonding and attachment. Research is needed in the areas of both PCC and Lotus birth. Copyright © 2017 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  15. Force-controlled patch clamp of beating cardiac cells.

    Science.gov (United States)

    Ossola, Dario; Amarouch, Mohamed-Yassine; Behr, Pascal; Vörös, János; Abriel, Hugues; Zambelli, Tomaso

    2015-03-11

    From its invention in the 1970s, the patch clamp technique is the gold standard in electrophysiology research and drug screening because it is the only tool enabling accurate investigation of voltage-gated ion channels, which are responsible for action potentials. Because of its key role in drug screening, innovation efforts are being made to reduce its complexity toward more automated systems. While some of these new approaches are being adopted in pharmaceutical companies, conventional patch-clamp remains unmatched in fundamental research due to its versatility. Here, we merged the patch clamp and atomic force microscope (AFM) techniques, thus equipping the patch-clamp with the sensitive AFM force control. This was possible using the FluidFM, a force-controlled nanopipette based on microchanneled AFM cantilevers. First, the compatibility of the system with patch-clamp electronics and its ability to record the activity of voltage-gated ion channels in whole-cell configuration was demonstrated with sodium (NaV1.5) channels. Second, we showed the feasibility of simultaneous recording of membrane current and force development during contraction of isolated cardiomyocytes. Force feedback allowed for a gentle and stable contact between AFM tip and cell membrane enabling serial patch clamping and injection without apparent cell damage.

  16. Voltage clamp methods for the study of membrane currents and SR Ca2+ release in adult skeletal muscle fibres

    Science.gov (United States)

    Hernández-Ochoa, Erick O.; Schneider, Martin F.

    2012-01-01

    Skeletal muscle excitation-contraction (E-C)1 coupling is a process composed of multiple sequential stages, by which an action potential triggers sarcoplasmic reticulum (SR)2 Ca2+ release and subsequent contractile activation. The various steps in the E-C coupling process in skeletal muscle can be studied using different techniques. The simultaneous recordings of sarcolemmal electrical signals and the accompanying elevation in myoplasmic Ca2+, due to depolarization-initiated SR Ca2+ release in skeletal muscle fibres, have been useful to obtain a better understanding of muscle function. In studying the origin and mechanism of voltage dependency of E-C coupling a variety of different techniques have been used to control the voltage in adult skeletal fibres. Pioneering work in muscles isolated from amphibians or crustaceans used microelectrodes or ‘high resistance gap’ techniques to manipulate the voltage in the muscle fibres. The development of the patch clamp technique and its variant, the whole-cell clamp configuration that facilitates the manipulation of the intracellular environment, allowed the use of the voltage clamp techniques in different cell types, including skeletal muscle fibres. The aim of this article is to present an historical perspective of the voltage clamp methods used to study skeletal muscle E-C coupling as well as to describe the current status of using the whole-cell patch clamp technique in studies in which the electrical and Ca2+ signalling properties of mouse skeletal muscle membranes are being investigated. PMID:22306655

  17. Enhanced chromatin accessibility of the dosage compensated Drosophila male X-chromosome requires the CLAMP zinc finger protein.

    Science.gov (United States)

    Urban, Jennifer; Kuzu, Guray; Bowman, Sarah; Scruggs, Benjamin; Henriques, Telmo; Kingston, Robert; Adelman, Karen; Tolstorukov, Michael; Larschan, Erica

    2017-01-01

    The essential process of dosage compensation is required to equalize gene expression of X-chromosome genes between males (XY) and females (XX). In Drosophila, the conserved Male-specific lethal (MSL) histone acetyltransferase complex mediates dosage compensation by increasing transcript levels from genes on the single male X-chromosome approximately two-fold. Consistent with its increased levels of transcription, the male X-chromosome has enhanced chromatin accessibility, distinguishing it from the autosomes. Here, we demonstrate that the non-sex-specific CLAMP (Chromatin-linked adaptor for MSL proteins) zinc finger protein that recognizes GA-rich sequences genome-wide promotes the specialized chromatin environment on the male X-chromosome and can act over long genomic distances (~14 kb). Although MSL complex is required for increasing transcript levels of X-linked genes, it is not required for enhancing global male X-chromosome chromatin accessibility, and instead works cooperatively with CLAMP to facilitate an accessible chromatin configuration at its sites of highest occupancy. Furthermore, CLAMP regulates chromatin structure at strong MSL complex binding sites through promoting recruitment of the Nucleosome Remodeling Factor (NURF) complex. In contrast to the X-chromosome, CLAMP regulates chromatin and gene expression on autosomes through a distinct mechanism that does not involve NURF recruitment. Overall, our results support a model where synergy between a non-sex-specific transcription factor (CLAMP) and a sex-specific cofactor (MSL) creates a specialized chromatin domain on the male X-chromosome.

  18. Analysis to Effect of Non-linear Axial Force on the MEMS Clamped-clamped Switch Beam

    Directory of Open Access Journals (Sweden)

    Cao Tian-Jie

    2014-04-01

    Full Text Available The effect of non-linear axial force, which is caused by both temperature change of environment and the length change of the beam, on the behavior of the switch is quite heavy because of the larger slenderness ratio of the MEMS clamped-clamped switch beams. By using the 1D beam model, the behaviors of electrostatic MEMS clamped-clamped switch beams with both the temperature change and the length change for three different stages were studied. In the paper, the governing equation of the elastic curve of the beam with the effect of non-linear axial force in the beam was given. A three-fold method of bisection was used to solve the unknown axial force in the governing equation, applied voltage and one boundary condition of the beam. On obtaining the axial force, the applied voltage and the boundary condition, the deflections at any cross-section could be obtained easily by using the numerical method to the ordinary differential equation. Incorporating the numerical method to the ordinary differential equation with some optimization method, pull-in voltage and the corresponding deflection could be distinguished and obtained automatically on a computer with the specifically designed program. In examples, the entire mechanical behavior of the MEMS clamped- clamped switch beam over the operational voltage ranges was investigated and the effects of the axial force on pull-in voltage at several temperature changes with different geometry dimensions of the beam were studied.

  19. Correlations of striatal dopamine synthesis with default network deactivations during working memory in younger adults.

    Science.gov (United States)

    Braskie, Meredith N; Landau, Susan M; Wilcox, Claire E; Taylor, Stephanie D; O'Neil, James P; Baker, Suzanne L; Madison, Cindee M; Jagust, William J

    2011-06-01

    Age-related deficits have been demonstrated in working memory performance and in the dopamine system thought to support it. We performed positron emission tomography (PET) scans on 12 younger (mean 22.7 years) and 19 older (mean 65.8 years) adults using the radiotracer 6-[(18)F]-fluoro-L-m-tyrosine (FMT), which measures dopamine synthesis capacity. Subjects also underwent functional magnetic resonance imaging (fMRI) while performing a delayed recognition working memory task. We evaluated age-related fMRI activity differences and examined how they related to FMT signal variations in dorsal caudate within each age group. In posterior cingulate cortex and precuneus (PCC/Pc), older adults showed diminished fMRI deactivations during memory recognition compared with younger adults. Greater task-induced deactivation (in younger adults only) was associated both with higher FMT signal and with worse memory performance. Our results suggest that dopamine synthesis helps modulate default network activity in younger adults and that alterations to the dopamine system may contribute to age-related changes in working memory function. Copyright © 2010 Wiley-Liss, Inc.

  20. Reactivation in Working Memory: An Attractor Network Model of Free Recall

    Science.gov (United States)

    Lansner, Anders; Marklund, Petter; Sikström, Sverker; Nilsson, Lars-Göran

    2013-01-01

    The dynamic nature of human working memory, the general-purpose system for processing continuous input, while keeping no longer externally available information active in the background, is well captured in immediate free recall of supraspan word-lists. Free recall tasks produce several benchmark memory phenomena, like the U-shaped serial position curve, reflecting enhanced memory for early and late list items. To account for empirical data, including primacy and recency as well as contiguity effects, we propose here a neurobiologically based neural network model that unifies short- and long-term forms of memory and challenges both the standard view of working memory as persistent activity and dual-store accounts of free recall. Rapidly expressed and volatile synaptic plasticity, modulated intrinsic excitability, and spike-frequency adaptation are suggested as key cellular mechanisms underlying working memory encoding, reactivation and recall. Recent findings on the synaptic and molecular mechanisms behind early LTP and on spiking activity during delayed-match-to-sample tasks support this view. PMID:24023690

  1. Reactivation in working memory: an attractor network model of free recall.

    Science.gov (United States)

    Lansner, Anders; Marklund, Petter; Sikström, Sverker; Nilsson, Lars-Göran

    2013-01-01

    The dynamic nature of human working memory, the general-purpose system for processing continuous input, while keeping no longer externally available information active in the background, is well captured in immediate free recall of supraspan word-lists. Free recall tasks produce several benchmark memory phenomena, like the U-shaped serial position curve, reflecting enhanced memory for early and late list items. To account for empirical data, including primacy and recency as well as contiguity effects, we propose here a neurobiologically based neural network model that unifies short- and long-term forms of memory and challenges both the standard view of working memory as persistent activity and dual-store accounts of free recall. Rapidly expressed and volatile synaptic plasticity, modulated intrinsic excitability, and spike-frequency adaptation are suggested as key cellular mechanisms underlying working memory encoding, reactivation and recall. Recent findings on the synaptic and molecular mechanisms behind early LTP and on spiking activity during delayed-match-to-sample tasks support this view.

  2. Cross-frequency synchronization connects networks of fast and slow oscillations during visual working memory maintenance

    Science.gov (United States)

    Siebenhühner, Felix; Wang, Sheng H; Palva, J Matias; Palva, Satu

    2016-01-01

    Neuronal activity in sensory and fronto-parietal (FP) areas underlies the representation and attentional control, respectively, of sensory information maintained in visual working memory (VWM). Within these regions, beta/gamma phase-synchronization supports the integration of sensory functions, while synchronization in theta/alpha bands supports the regulation of attentional functions. A key challenge is to understand which mechanisms integrate neuronal processing across these distinct frequencies and thereby the sensory and attentional functions. We investigated whether such integration could be achieved by cross-frequency phase synchrony (CFS). Using concurrent magneto- and electroencephalography, we found that CFS was load-dependently enhanced between theta and alpha–gamma and between alpha and beta-gamma oscillations during VWM maintenance among visual, FP, and dorsal attention (DA) systems. CFS also connected the hubs of within-frequency-synchronized networks and its strength predicted individual VWM capacity. We propose that CFS integrates processing among synchronized neuronal networks from theta to gamma frequencies to link sensory and attentional functions. DOI: http://dx.doi.org/10.7554/eLife.13451.001 PMID:27669146

  3. Is networking different with doctors working part-time? Differences in social networks of part-time and full-time doctors.

    Science.gov (United States)

    Heiligers, Phil J M; de Jong, Judith D; Groenewegen, Peter P; Hingstman, Lammert; Völker, Beate; Spreeuwenberg, Peter

    2008-10-04

    Part-time working is a growing phenomenon in medicine, which is expected to influence informal networks at work differently compared to full-time working. The opportunity to meet and build up social capital at work has offered a basis for theoretical arguments. Twenty-eight teams of medical specialists in the Netherlands, including 226 individuals participated in this study. Interviews with team representatives and individual questionnaires were used. Data were gathered on three types of networks: relationships of consulting, communication and trust. For analyses, network and multilevel applications were used. Differences between individual doctors and between teams were both analysed, taking the dependency structure of the data into account, because networks of individual doctors are not independent. Teams were divided into teams with and without doctors working part-time. Contrary to expectations we found no impact of part-time working on the size of personal networks, neither at the individual nor at the team level. The same was found regarding efficient reachability. Whereas we expected part-time doctors to choose their relations as efficiently as possible, we even found the opposite in intended relationships of trust, implying that efficiency in reaching each other was higher for full-time doctors. But we found as expected that in mixed teams with part-time doctors the frequency of regular communication was less compared to full-time teams. Furthermore, as expected the strength of the intended relationships of trust of part-time and full-time doctors was equally high. From these findings we can conclude that part-time doctors are not aiming at efficiency by limiting the size of networks or by efficient reachability, because they want to contact their colleagues directly in order to prevent from communication errors. On the other hand, together with the growth of teams, we found this strategy, focussed on reaching all colleagues, was diminishing. And our data

  4. Meteorological Support Interface Control Working Group (MSICWG) Instrumentation, Data Format, and Networks Document

    Science.gov (United States)

    Brenton, James; Roberts, Barry C.

    2017-01-01

    The purpose of this document is to provide an overview of instrumentation discussed at the Meteorological Interface Control Working Group (MSICWG), a reference for data formats currently used by members of the group, a summary of proposed formats for future use by the group, an overview of the data networks of the group's members. This document will be updated as new systems are introduced, old systems are retired, and when the MSICWG community necessitates a change to the formats. The MSICWG consists of personnel from the National Aeronautics and Space Administration (NASA) Kennedy Space Center (KSC), NASA Marshall Space Flight Center (MSFC), NASA Johnson Space Center (JSC), National Oceanic and Atmospheric Administration National Weather Service Spaceflight Meteorology Group (SMG), and the United States Air Force (USAF) 45th Space Wing and Weather Squadron. The purpose of the group is to coordinate the distribution of weather related data to support NASA space launch related activities.

  5. Economic, Energetic, and Environmental Impact Evaluation of the Water Discharge Networks from Mining Works

    Directory of Open Access Journals (Sweden)

    Andrei Cristian Rada

    2018-01-01

    Full Text Available Sustainable development represents an optimistic scenario for the evolution of contemporary civilization. The object of this paper is to define certain evaluation criteria regarding the performances of water discharge networks from mining works, and propose a method for aggregating the specific indicators for monetary costs, energetic costs, and environmental impact-related costs. The global pollution index (GPI represents a method for assessing environment health status or pollution levels. The GPI quantitatively expresses this status based on its index, which results from a ratio between the ideal value and the given value of certain quality indices that are considered specific for the analyzed environmental factors at certain moments. The proposed method in this paper tries to perform a synergistic aggregation of the balance sheet of harmfulness and classic balance sheets for matter and energy for an industrial process.

  6. Measuring beta-cell function relative to insulin sensitivity in youth: Does the hyperglycemic clamp suffice?

    Science.gov (United States)

    To compare beta-cell function relative to insulin sensitivity, disposition index (DI), calculated from two clamps (2cDI, insulin sensitivity from the hyperinsulinemic-euglycemic clamp and first-phase insulin from the hyperglycemic clamp) with the DI calculated from the hyperglycemic clamp alone (hcD...

  7. Model Predictive Control of Z-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    2011-01-01

    This paper presents Model Predictive Control (MPC) of Z-source Neutral Point Clamped (NPC) inverter. For illustration, current control of Z-source NPC grid-connected inverter is analyzed and simulated. With MPC’s advantage of easily including system constraints, load current, impedance network...... inductor current, capacitor voltage as well as switching frequency, transient response are all regulated as subjecting to constraints of this control method. The quality of output waveform, stability of impedance-network, level constraint of variable switching frequency as well as robustness of transient...... response are obtained at the same time with a formulated Z-source NPC inverter network model. Operation steady state and transient state simulation results of MPC are going to be presented, which shows good reference tracking ability of this method. It provides new control method for Z-source NPC inverter...

  8. Learning for Work and Professional Development: The Significance of Informal Learning Networks of Digital Media Industry Professionals

    Science.gov (United States)

    Campana, Joe

    2014-01-01

    Informal learning networks play a key role in the skill and professional development of professionals, working in micro-businesses within Australia's digital media industry, as they do not have access to learning and development or human resources sections that can assist in mapping their learning pathway. Professionals working in this environment…

  9. Modulation of steady state functional connectivity in the default mode and working memory networks by cognitive load.

    Science.gov (United States)

    Newton, Allen T; Morgan, Victoria L; Rogers, Baxter P; Gore, John C

    2011-10-01

    Interregional correlations between blood oxygen level dependent (BOLD) magnetic resonance imaging (fMRI) signals in the resting state have been interpreted as measures of connectivity across the brain. Here we investigate whether such connectivity in the working memory and default mode networks is modulated by changes in cognitive load. Functional connectivity was measured in a steady-state verbal identity N-back task for three different conditions (N = 1, 2, and 3) as well as in the resting state. We found that as cognitive load increases, the functional connectivity within both the working memory the default mode network increases. To test whether functional connectivity between the working memory and the default mode networks changed, we constructed maps of functional connectivity to the working memory network as a whole and found that increasingly negative correlations emerged in a dorsal region of the posterior cingulate cortex. These results provide further evidence that low frequency fluctuations in BOLD signals reflect variations in neural activity and suggests interaction between the default mode network and other cognitive networks. Copyright © 2010 Wiley-Liss, Inc.

  10. Effects of Stress and Task Difficulty on Working Memory and Cortical Networking.

    Science.gov (United States)

    Kim, Yujin; Woo, Jihwan; Woo, Minjung

    2017-12-01

    This study investigated interactive effects of stress and task difficulty on working memory and cortico-cortical communication during memory encoding. Thirty-eight adolescent participants (mean age of 15.7 ± 1.5 years) completed easy and hard working memory tasks under low- and high-stress conditions. We analyzed the accuracy and reaction time (RT) of working memory performance and inter- and intrahemispheric electroencephalogram coherences during memory encoding. Working memory accuracy was higher, and RT shorter, in the easy versus the hard task. RT was shorter under the high-stress (TENS) versus low-stress (no-TENS) condition, while there was no difference in memory accuracy between the two stress conditions. For electroencephalogram coherence, we found higher interhemispheric coherence in all bands but only at frontal electrode sites in the easy versus the hard task. On the other hand, intrahemispheric coherence was higher in the left hemisphere in the easy (versus hard task) and higher in the right hemisphere (with one exception) in the hard (versus easy task). Inter- and intracoherences were higher in the low- versus high-stress condition. Significant interactions between task difficulty and stress condition were observed in coherences of the beta frequency band. The difference in coherence between low- and high-stress conditions was greater in the hard compared with the easy task, with lower coherence under the high-stress condition relative to the low-stress condition. Stress seemed to cause a decrease in cortical network communications between memory-relevant cortical areas as task difficulty increased.

  11. The impact of electronic health records on collaborative work routines: A narrative network analysis.

    Science.gov (United States)

    Chao, Chia-An

    2016-10-01

    This study examined collaborative work routines and changes after the implementation of a perinatal EHR. The change process and underlying drivers were analyzed to offer insight into why changes - intended or unintended - did or did not occur and their implications for EHR design and implementation. This mixed-method case study included both qualitative and quantitative information. Pre- and post-implementation observations took place over an 18-month period totaling 90h. Formal and informal interviews with administrative and clinical staff, pre- and post-implementation surveys, project meeting observations, and artifact review supplemented data gathered from the observations. Workflow and narrative network analyses of work routines were used to identify changes pre- and post-EHR and to represent different perspectives of work routines. EHR improved documentation efficiency and in- and out-patient information exchange, but increased variability in documentation. Some variabilities were institutionally sanctioned or tolerated, but other variabilities - while ingenious and emblematic of the generative nature of routines enabled by the EHR - were problematic. EHR's support for clinician communication and coordination was limited and its cognitive support insufficient. In some cases, EHR increased cognitive load as the unlocalized EHR scattered information, and the lengthy printouts contributed to information fragmentation and made information retrieval more difficult. The process of the EHR implementation and the changes observed was the confluence of three factors: resource constraint - in particular EHR expertise and experience - not uncommon in many community hospitals; the functional properties of the EHR focusing on information aggregation, storage, and retrieval; and the extant culture and practice of healthcare emphasizing autonomy and flexibility. While collaborative and communication changes were prompted by EHR implementation, the system played a minimal

  12. Analyzing of Nonuniform Hardness for Anchorage Clamp Plate after Heat Treatment

    Science.gov (United States)

    Liu, Zhenmin; Wang, Lijun; Ruan, Shipeng; Wang, Ningtao

    2017-09-01

    20CrMnTi wire rod can be used to manufacture the anchorage clamp plate. In the normal production, the test results show that the hardness of anchorage clamp plate is nonuniform. In this paper, the chemical composition, microstructure, grain size of clamp plate billet and the microstructure, hardness of the finished clamp plate product were studied and analyzed. The results show that improper heat treatment technics causes nonuniform hardness for anchorage clamp plate.

  13. Oral health related quality of life in pregnant and post partum women in two social network domains; predominantly home-based and work-based networks.

    Science.gov (United States)

    Lamarca, Gabriela A; Leal, Maria do C; Leao, Anna T T; Sheiham, Aubrey; Vettore, Mario V

    2012-01-13

    Individuals connected to supportive social networks have better general and oral health quality of life. The objective of this study was to assess whether there were differences in oral health related quality of life (OHRQoL) between women connected to either predominantly home-based and work-based social networks. A follow-up prevalence study was conducted on 1403 pregnant and post-partum women (mean age of 25.2 ± 6.3 years) living in two cities in the State of Rio de Janeiro, Brazil. Women were participants in an established cohort followed from pregnancy (baseline) to post-partum period (follow-up). All participants were allocated to two groups; 1. work-based social network group--employed women with paid work, and, 2. home-based social network group--women with no paid work, housewives or unemployed women. Measures of social support and social network were used as well as questions on sociodemographic characteristics and OHRQoL and health related behaviors. Multinomial logistic regression was performed to obtain OR of relationships between occupational contexts, affectionate support and positive social interaction on the one hand, and oral health quality of life, using the Oral Health Impacts Profile (OHIP) measure, adjusted for age, ethnicity, family income, schooling, marital status and social class. There was a modifying effect of positive social interaction on the odds of occupational context on OHRQoL. The odds of having a poorer OHIP score, ≥ 4, was significantly higher for women with home-based social networks and moderate levels of positive social interactions [OR 1.64 (95% CI: 1.08-2.48)], and for women with home-based social networks and low levels of positive social interactions [OR 2.15 (95% CI: 1.40-3.30)] compared with women with work-based social networks and high levels of positive social interactions. Black ethnicity was associated with OHIP scores ≥ 4 [OR 1.73 (95% CI: 1.23-2.42)]. Pregnant and post-partum Brazilian women in paid

  14. Oral health related quality of life in pregnant and post partum women in two social network domains; predominantly home-based and work-based networks

    Directory of Open Access Journals (Sweden)

    Lamarca Gabriela A

    2012-01-01

    Full Text Available Abstract Background Individuals connected to supportive social networks have better general and oral health quality of life. The objective of this study was to assess whether there were differences in oral health related quality of life (OHRQoL between women connected to either predominantly home-based and work-based social networks. Methods A follow-up prevalence study was conducted on 1403 pregnant and post-partum women (mean age of 25.2 ± 6.3 years living in two cities in the State of Rio de Janeiro, Brazil. Women were participants in an established cohort followed from pregnancy (baseline to post-partum period (follow-up. All participants were allocated to two groups; 1. work-based social network group - employed women with paid work, and, 2. home-based social network group - women with no paid work, housewives or unemployed women. Measures of social support and social network were used as well as questions on sociodemographic characteristics and OHRQoL and health related behaviors. Multinomial logistic regression was performed to obtain OR of relationships between occupational contexts, affectionate support and positive social interaction on the one hand, and oral health quality of life, using the Oral Health Impacts Profile (OHIP measure, adjusted for age, ethnicity, family income, schooling, marital status and social class. Results There was a modifying effect of positive social interaction on the odds of occupational context on OHRQoL. The odds of having a poorer OHIP score, ≥4, was significantly higher for women with home-based social networks and moderate levels of positive social interactions [OR 1.64 (95% CI: 1.08-2.48], and for women with home-based social networks and low levels of positive social interactions [OR 2.15 (95% CI: 1.40-3.30] compared with women with work-based social networks and high levels of positive social interactions. Black ethnicity was associated with OHIP scores ≥4 [OR 1.73 (95% CI: 1

  15. Oral health related quality of life in pregnant and post partum women in two social network domains; predominantly home-based and work-based networks

    National Research Council Canada - National Science Library

    Lamarca, Gabriela A; Leal, Maria do C; Leao, Anna T T; Sheiham, Aubrey; Vettore, Mario V

    2012-01-01

    ...) between women connected to either predominantly home-based and work-based social networks. A follow-up prevalence study was conducted on 1403 pregnant and post-partum women (mean age of 25.2 ± 6.3 years...

  16. Reorganization of functional brain networks mediates the improvement of cognitive performance following real-time neurofeedback training of working memory.

    Science.gov (United States)

    Zhang, Gaoyan; Yao, Li; Shen, Jiahui; Yang, Yihong; Zhao, Xiaojie

    2015-05-01

    Working memory (WM) is essential for individuals' cognitive functions. Neuroimaging studies indicated that WM fundamentally relied on a frontoparietal working memory network (WMN) and a cinguloparietal default mode network (DMN). Behavioral training studies demonstrated that the two networks can be modulated by WM training. Different from the behavioral training, our recent study used a real-time functional MRI (rtfMRI)-based neurofeedback method to conduct WM training, demonstrating that WM performance can be significantly improved after successfully upregulating the activity of the target region of interest (ROI) in the left dorsolateral prefrontal cortex (Zhang et al., [2013]: PloS One 8:e73735); however, the neural substrate of rtfMRI-based WM training remains unclear. In this work, we assessed the intranetwork and internetwork connectivity changes of WMN and DMN during the training, and their correlations with the change of brain activity in the target ROI as well as with the improvement of post-training behavior. Our analysis revealed an "ROI-network-behavior" correlation relationship underlying the rtfMRI training. Further mediation analysis indicated that the reorganization of functional brain networks mediated the effect of self-regulation of the target brain activity on the improvement of cognitive performance following the neurofeedback training. The results of this study enhance our understanding of the neural basis of real-time neurofeedback and suggest a new direction to improve WM performance by regulating the functional connectivity in the WM related networks. © 2014 Wiley Periodicals, Inc.

  17. Securing a Wireless Site Network to Create a BIM-Allied Work-Front

    Directory of Open Access Journals (Sweden)

    Payam R. Zekavat

    2014-08-01

    Full Text Available The Building Information Model (BIM serves as a framework to align all the project-related data, providing interoperability to store and retrieve information interactively. Unfortunately, the construction site itself is excluded from this interaction as the large amount of data requires high data transfer rates and ruggedized hardware. However, advanced wireless communication technologies open radically new avenues to relay large amounts of data automatically and in near real-time. Construction could be a key beneficiary of these advancements. Wireless communication integrated with BIM, GPS and the Internet is able to provide the backbone necessary for creating intelligent systems, supporting the designer in his or her office as well as workers on the work-front. This paper presents a study that documents the development and testing of prototypes designed to facilitate information sharing at the field-level during construction. The main system constitutes an information hub, called the eCKiosk, connecting “senders and receivers” both on-site as well as off-site. The system design is discussed and some of the main modules are demonstrated. Since the electronic Kiosk depends on robust connections to the wireless devices distributed across the site, reliable connectivity is essential. For this reason, the discussion includes a study of the electronic signals behaviour in an ever-changing construction site. Measurements of the signal strengths during excavation and concrete work are presented and compared with theoretical calculations used to predict wave propagation. The results show how present models overestimate signal attenuation patterns on the construction site. This is important for designing a reliable and secure wireless site networks to link BIM to the work-front.

  18. Caffeine impact on working memory-related network activation patterns in early stages of cognitive decline

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Sven [Affidea Centre de Diagnostic Radiologique de Carouge CDRC, Geneva (Switzerland); Uppsala University, Department of Surgical Sciences, Radiology, Uppsala (Sweden); Montandon, Marie-Louise; Rodriguez, Cristelle; Moser, Dominik; Toma, Simona; Hofmeister, Jeremy; Giannakopoulos, Panteleimon [University Hospitals of Geneva, Department of Psychiatry, Faculty of Medicine, Medical Direction, Geneva (Switzerland)

    2017-04-15

    Recent evidence indicates that caffeine may have a beneficial effect on cognitive decline and dementia. The current investigation assessed the effect of acute caffeine administration on working memory during the earliest stage of cognitive decline in elderly participants. The study includes consecutive 45 elderly controls and 18 individuals with mild cognitive impairment (MCI, 71.6 ± 4.7 years, 7 females). During neuropsychological follow-up at 18 months, 24 controls remained stable (sCON, 70.0 ± 4.3 years, 11 women), while the remaining 21 showed subtle cognitive deterioration (dCON, 73.4 ± 5.9 years, 14 women). All participants underwent an established 2-back working task in a crossover design of 200 mg caffeine versus placebo. Data analysis included task-related general linear model and functional connectivity tensorial independent component analysis. Working memory behavioral performances did not differ between sCON and dCON, while MCI was slower and less accurate than both control groups (p < 0.05). The dCON group had a less pronounced effect of acute caffeine administration essentially restricted to the right hemisphere (p < 0.05 corrected) and reduced default mode network (DMN) deactivation compared to sCON (p < 0.01 corrected). dCON cases are characterized by decreased sensitivity to caffeine effects on brain activation and DMN deactivation. These complex fMRI patterns possibly reflect the instable status of these cases with intact behavioral performances despite already existing functional alterations in neocortical circuits. (orig.)

  19. Calcium-activated potassium current clamps the dark potential of vertebrate rods.

    Science.gov (United States)

    Moriondo, A; Pelucchi, B; Rispoli, G

    2001-07-01

    Vertebrate photoreceptors respond to light with a graded hyperpolarization from a membrane potential in the dark of approximately -35 mV. The present work investigates the physiological role of the Ca2+-activated K+ current in the photovoltage generation in mechanically isolated rods from salamander retina. Membrane current or voltage in isolated rods was recorded from light- and dark-adapted rods under voltage- or current-clamp conditions, respectively. In light-adapted rods of the salamander, selective blockade of Ca2+-activated K+ channels by means of charybdotoxin depolarized the plasma membrane of current-clamped rods by approximately 30 mV, from a resting potential of approximately -35 mV. A similar depolarization was observed if external Ca2+ (1 mM) was substituted with Ba2+ or Sr2+. Under control conditions, the injection of currents of increasing amplitude (up to -100 pA, to mimic the current entering the rod outer segment) could not depolarize the membrane potential beyond a saturating value of approximately -20 mV. However, in the presence of charybdotoxin, rods depolarized up to +20 mV. In experiments with dark-adapted current-clamped rods, charybdotoxin perfusion lead to transient depolarizations up to 0 mV and steady-state depolarizations of approximately 5 mV above the dark resting potential. Finally, the recovery phase of the voltage response to a flash of light in the presence of charybdotoxin showed a transient overshoot of the membrane potential. It was concluded that Ca2+-activated K+ current is necessary for clamping the rod photovoltage to values close to the dark potential, thus allowing faithful single photon detection and correct synaptic transmission.

  20. [Advantage of delayed umbilical cord clamping in the newborn infant].

    Science.gov (United States)

    Menget, A; Mougey, C; Thiriez, G; Riethmuller, D

    2013-09-01

    The timing of umbilical cord clamping remains controversial. Although most maternity wards use the early clamping (5-15s), randomized studies and meta-analyses have demonstrated the benefit of delayed clamping for term and preterm newborn infants over the past 10 years. Indeed, placentofetal transfusion of 20-30 ml/kg in 2-3 min improves the iron status of term infants and prevents infant hypochromic anemia. Infant anemia is a public health problem in many developing countries. For preterm newborns, placental transfusion for 45 s or milking the cord for 15 s improves cardiovascular adaptation, with better hemodynamic stability, as well as decreased intraventricular hemorrhages, need for transfusion, and late-onset sepsis. A new look at this symbolic act is needed and professionals need to be persuaded of the importance of the "wait a minute" policy for a better physiological delivery. Copyright © 2013. Published by Elsevier SAS.

  1. Ramp-incremented and RPE-clamped test protocols elicit similar VO2max values in trained cyclists.

    Science.gov (United States)

    Straub, Allison M; Midgley, Adrian W; Zavorsky, Gerald S; Hillman, Angela R

    2014-08-01

    The present study compared the efficacy of ramp incremented and ratings of perceived exertion (RPE)-clamped test protocols for eliciting maximal oxygen uptake (VO2max). Sixteen trained cyclists (age 34 ± 7 years) performed a ramp-incremented protocol and an RPE-clamped protocol 1 week apart in a randomized, counterbalanced order. The RPE-clamped protocol consisted of five, 2-min stages where subjects self-selected work rate and pedal cadence to maintain the prescribed RPE. After completing both test protocols subjects were asked which they preferred. The mean ± SD test time of 568 ± 72 s in the ramp protocol was not significantly different to the 600 ± 0 s in the RPE-clamped protocol (mean difference = 32 s; p = 0.09), or was the VO2max of 3.86 ± 0.73 L min(-1) in the ramp protocol significantly different to the 3.87 ± 0.72 L min(-1) in the RPE-clamped protocol (mean difference = 0.002 L min(-1); p = 0.97). Furthermore, no significant differences were observed for peak power output (p = 0.21), maximal minute ventilation (p = 0.97), maximal respiratory exchange ratio (p = 0.09), maximal heart rate (p = 0.51), and post-test blood lactate concentration (p = 0.58). The VO2max attained in the preferred protocol was significantly higher than the non-preferred protocol (mean difference = 0.14 L min(-1); p = 0.03). The RPE-clamped test protocol was as effective as the ramp-incremented protocol for eliciting VO2max and could be considered as a valid alternative protocol, particularly where a fixed test duration is desirable.

  2. Novel description of ionic currents recorded with the action potential clamp technique: application to excitatory currents in suprachiasmatic nucleus neurons.

    Science.gov (United States)

    Clay, John R

    2015-07-01

    The traditional method of recording ionic currents in neurons has been with voltage-clamp steps. Other waveforms such as action potentials (APs) can be used. The AP clamp method reveals contributions of ionic currents that underlie excitability during an AP (Bean BP. Nat Rev Neurosci 8: 451-465, 2007). A novel usage of the method is described in this report. An experimental recording of an AP from the literature is digitized and applied computationally to models of ionic currents. These results are compared with experimental AP-clamp recordings for model verification or, if need be, alterations to the model. The method is applied to the tetrodotoxin-sensitive sodium ion current, INa, and the calcium ion current, ICa, from suprachiasmatic nucleus (SCN) neurons (Jackson AC, Yao GL, Bean BP. J Neurosci 24: 7985-7998, 2004). The latter group reported voltage-step and AP-clamp results for both components. A model of INa is constructed from their voltage-step results. The AP clamp computational methodology applied to that model compares favorably with experiment, other than a modest discrepancy close to the peak of the AP that has not yet been resolved. A model of ICa was constructed from both voltage-step and AP-clamp results of this component. The model employs the Goldman-Hodgkin-Katz equation for the current-voltage relation rather than the traditional linear dependence of this aspect of the model on the Ca(2+) driving force. The long-term goal of this work is a mathematical model of the SCN AP. The method is general. It can be applied to any excitable cell.

  3. New active load voltage clamp for HF-link converters

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, M.A.E.

    2005-07-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path during malfunctions of the secondary bidirectional bridge. The feasibility of the approach is shown on audio power amplifier prototype. New integrated magnetics design is presented that incorporates both the main power and auxiliary transformer on the same magnetic core. (au)

  4. Plasma temperature clamping in filamentation laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Harilal, Sivanandan S.; Yeak, J.; Phillips, Mark C.

    2015-10-19

    Ultrafast laser filament induced breakdown spectroscopy is a very promising method for remote material detection. We present characteristics of plasmas generated in a metal target by laser filaments in air. Our measurements show that the temperature of the ablation plasma is clamped along the filamentation channel due to intensity clamping in a filament. Nevertheless, significant changes in radiation intensity are noticeable, and this is essentially due to variation in the number density of emitting atoms. The present results also partly explains the reason for the occurrence of atomic plume during fs LIBS in air compared to long-pulse ns LIBS.

  5. Impact of real-time fMRI working memory feedback training on the interactions between three core brain networks

    Directory of Open Access Journals (Sweden)

    Qiushi eZhang

    2015-09-01

    Full Text Available Working memory (WM refers to the temporary holding and manipulation of information during the performance of a range of cognitive tasks, and WM training is a promising method for improving an individual’s cognitive functions. Our previous work demonstrated that WM performance can be improved through self-regulation of dorsal lateral prefrontal cortex activation using real-time functional magnetic resonance imaging (rtfMRI, which enables individuals to control local brain activities volitionally according to the neurofeedback. Furthermore, research concerning large-scale brain networks has demonstrated that WM training requires the engagement of several networks, including the central executive network (CEN, the default mode network (DMN and the salience network (SN, and functional connectivity within the CEN and DMN can be changed by WM training. Although a switching role of the SN between the CEN and DMN has been demonstrated, it remains unclear whether WM training can affect the interactions between the three networks and whether a similar mechanism also exists during the training process. In this study, we investigated the dynamic functional connectivity between the three networks during the rtfMRI feedback training using independent component analysis and correlation analysis. The results indicated that functional connectivity within and between the three networks were significantly enhanced by feedback training, and most of the changes were associated with the insula and correlated with behavioral improvements. These findings suggest that the insula plays a critical role in the reorganization of functional connectivity among the three networks induced by rtfMRI training and in WM performance, thus providing new insights into the mechanisms of high-level functions and the clinical treatment of related functional impairments.

  6. Impact of real-time fMRI working memory feedback training on the interactions between three core brain networks.

    Science.gov (United States)

    Zhang, Qiushi; Zhang, Gaoyan; Yao, Li; Zhao, Xiaojie

    2015-01-01

    Working memory (WM) refers to the temporary holding and manipulation of information during the performance of a range of cognitive tasks, and WM training is a promising method for improving an individual's cognitive functions. Our previous work demonstrated that WM performance can be improved through self-regulation of dorsal lateral prefrontal cortex (PFC) activation using real-time functional magnetic resonance imaging (rtfMRI), which enables individuals to control local brain activities volitionally according to the neurofeedback. Furthermore, research concerning large-scale brain networks has demonstrated that WM training requires the engagement of several networks, including the central executive network (CEN), the default mode network (DMN) and the salience network (SN), and functional connectivity within the CEN and DMN can be changed by WM training. Although a switching role of the SN between the CEN and DMN has been demonstrated, it remains unclear whether WM training can affect the interactions between the three networks and whether a similar mechanism also exists during the training process. In this study, we investigated the dynamic functional connectivity between the three networks during the rtfMRI feedback training using independent component analysis (ICA) and correlation analysis. The results indicated that functional connectivity within and between the three networks were significantly enhanced by feedback training, and most of the changes were associated with the insula and correlated with behavioral improvements. These findings suggest that the insula plays a critical role in the reorganization of functional connectivity among the three networks induced by rtfMRI training and in WM performance, thus providing new insights into the mechanisms of high-level functions and the clinical treatment of related functional impairments.

  7. Social networks, work and network-based resources for the management of long-term conditions: a framework and study protocol for developing self-care support

    Directory of Open Access Journals (Sweden)

    Kapadia Dharmi

    2011-05-01

    Full Text Available Abstract Background Increasing the effective targeting and promotion of self-care support for long-term conditions requires more of a focus on patient contexts and networks. The aim of this paper is to describe how within a programme of research and implementation, social networks are viewed as being centrally involved in the mobilisation and deployment of resources in the management of a chronic condition. This forms the basis of a novel approach to understanding, designing, and implementing new forms of self-management support. Methods Drawing on evidence syntheses about social networks and capital and the role of information in self-management, we build on four conceptual approaches to inform the design of our research on the implementation of self-care support for people with long-term conditions. Our approach takes into consideration the form and content of social networks, notions of chronic illness work, normalisation process theory (NPT, and the whole systems informing self-management engagement (WISE approach to self-care support. Discussion The translation and implementation of a self-care agenda in contemporary health and social context needs to acknowledge and incorporate the resources and networks operating in patients' domestic and social environments and everyday lives. The latter compliments the focus on healthcare settings for developing and delivering self-care support by viewing communities and networks, as well as people suffering from long-term conditions, as a key means of support for managing long-term conditions. By focusing on patient work and social-network provision, our aim is to open up a second frontier in implementation research, to translate knowledge into better chronic illness management, and to shift the emphasis towards support that takes place outside formal health services.

  8. Social networks, work and network-based resources for the management of long-term conditions: a framework and study protocol for developing self-care support.

    Science.gov (United States)

    Rogers, Anne; Vassilev, Ivaylo; Sanders, Caroline; Kirk, Susan; Chew-Graham, Carolyn; Kennedy, Anne; Protheroe, Joanne; Bower, Peter; Blickem, Christian; Reeves, David; Kapadia, Dharmi; Brooks, Helen; Fullwood, Catherine; Richardson, Gerry

    2011-05-29

    Increasing the effective targeting and promotion of self-care support for long-term conditions requires more of a focus on patient contexts and networks. The aim of this paper is to describe how within a programme of research and implementation, social networks are viewed as being centrally involved in the mobilisation and deployment of resources in the management of a chronic condition. This forms the basis of a novel approach to understanding, designing, and implementing new forms of self-management support. Drawing on evidence syntheses about social networks and capital and the role of information in self-management, we build on four conceptual approaches to inform the design of our research on the implementation of self-care support for people with long-term conditions. Our approach takes into consideration the form and content of social networks, notions of chronic illness work, normalisation process theory (NPT), and the whole systems informing self-management engagement (WISE) approach to self-care support. The translation and implementation of a self-care agenda in contemporary health and social context needs to acknowledge and incorporate the resources and networks operating in patients' domestic and social environments and everyday lives. The latter compliments the focus on healthcare settings for developing and delivering self-care support by viewing communities and networks, as well as people suffering from long-term conditions, as a key means of support for managing long-term conditions. By focusing on patient work and social-network provision, our aim is to open up a second frontier in implementation research, to translate knowledge into better chronic illness management, and to shift the emphasis towards support that takes place outside formal health services.

  9. A neural networks application for the study of the influence of transport conditions on the working performance

    Science.gov (United States)

    Anghel, D.-C.; Ene, A.; Ştirbu, C.; Sicoe, G.

    2017-10-01

    This paper presents a study about the factors that influence the working performances of workers in the automotive industry. These factors regard mainly the transportations conditions, taking into account the fact that a large number of workers live in places that are far away of the enterprise. The quantitative data obtained from this study will be generalized by using a neural network, software simulated. The neural network is able to estimate the performance of workers even for the combinations of input factors that had been not recorded by the study. The experimental data obtained from the study will be divided in two classes. The first class that contains approximately 80% of data will be used by the Java software for the training of the neural network. The weights resulted from the training process will be saved in a text file. The other class that contains the rest of the 20% of experimental data will be used to validate the neural network. The training and the validation of the networks are performed in a Java software (TrainAndValidate java class). We designed another java class, Test.java that will be used with new input data, for new situations. The experimental data collected from the study. The software that simulated the neural network. The software that estimates the working performance, when new situations are met. This application is useful for human resources department of an enterprise. The output results are not quantitative. They are qualitative (from low performance to high performance, divided in five classes).

  10. Ranking Features on Psychological Dynamics of Cooperative Team Work through Bayesian Networks

    Directory of Open Access Journals (Sweden)

    Pilar Fuster-Parra

    2016-05-01

    Full Text Available The aim of this study is to rank some features that characterize the psychological dynamics of cooperative team work in order to determine priorities for interventions and formation: leading positive feedback, cooperative manager and collaborative manager features. From a dataset of 20 cooperative sport teams (403 soccer players, the characteristics of the prototypical sports teams are studied using an average Bayesian network (BN and two special types of BNs, the Bayesian classifiers: naive Bayes (NB and tree augmented naive Bayes (TAN. BNs are selected as they are able to produce probability estimates rather than predictions. BN results show that the antecessors (the “top” features ranked are the team members’ expectations and their attraction to the social aspects of the task. The main node is formed by the cooperative behaviors, the consequences ranked at the BN bottom (ratified by the TAN trees and the instantiations made, the roles assigned to the members and their survival inside the same team. These results should help managers to determine contents and priorities when they have to face team-building actions.

  11. ANALYTICAL BENDING SOLUTION OF ALL CLAMPED ISOTROPIC ...

    African Journals Online (AJOL)

    ™s works method was applied to the governing differential equation of the plate on Winkler foundation to obtain the deflection coefficient, . Numerical example was presented at the end to compare the results obtained by this method and those ...

  12. From understanding cellular function to novel drug discovery: the role of planar patch-clamp array chip technology

    Directory of Open Access Journals (Sweden)

    Christophe ePy

    2011-10-01

    Full Text Available All excitable cell functions rely upon ion channels that are embedded in their plasma membrane. Perturbations of ion channel structure or function result in pathologies ranging from cardiac dysfunction to neurodegenerative disorders. Consequently, to understand the functions of excitable cells and to remedy their pathophysiology, it is important to understand the ion channel functions under various experimental conditions – including exposure to novel drug targets. Glass pipette patch-clamp is the state of the art technique to monitor the intrinsic and synaptic properties of neurons. However, this technique is labor-intensive and has low data throughput. Planar patch-clamp chips, integrated into automated systems, offer high throughputs but are limited to isolated cells from suspensions, resulting in questionable models of true physiological function, and are unsuitable for studies involving neuronal communication. Multi-electrode arrays (MEA, in contrast, have the ability to monitor network activity by measuring local field potentials from multiple extracellular sites, but specific ion channel activity is challenging to extract from these multiplexed signals. Here we describe a novel planar patch-clamp chip technology that enables the simultaneous high resolution electrophysiological interrogation of individual neurons at multiple sites in synaptically connected neuronal networks, thereby combining the advantages of MEA and patch-clamp techniques. Each neuron can be probed through an aperture that connects to a dedicated subterranean microfluidic channel. Neurons growing in networks are aligned to the apertures by physisorbed or chemisorbed chemical cues. In this review, we describe the design and fabrication process of these chips, the approach to the chemical patterning for cell placement, and present physiological data from cultured neuronal cells.

  13. Impact of Individual Proliferating Cell Nuclear Antigen-DNA Contacts on Clamp Loading and Function on DNA*

    Science.gov (United States)

    Zhou, Yayan; Hingorani, Manju M.

    2012-01-01

    Ring-shaped clamp proteins encircle DNA and affect the work of many proteins, notably processive replication by DNA polymerases. Crystal structures of clamps show several cationic residues inside the ring, and in a co-crystal of Escherichia coli β clamp-DNA, they directly contact the tilted duplex passing through (Georgescu, R. E., Kim, S. S., Yurieva, O., Kuriyan, J., Kong, X. P., and O'Donnell, M. (2008) Structure of a sliding clamp on DNA. Cell 132, 43–54). To investigate the role of these contacts in reactions involving circular clamps, we examined single arginine/lysine mutants of Saccharomyces cerevisiae proliferating cell nuclear antigen (PCNA) in replication factor C (RFC)-catalyzed loading of the clamp onto primer template DNA (ptDNA). Previous kinetic analysis has shown that ptDNA entry inside an ATP-activated RFC-PCNA complex accelerates clamp opening and ATP hydrolysis, which is followed by slow PCNA closure around DNA and product dissociation. Here we directly measured multiple steps in the reaction (PCNA opening, ptDNA binding, PCNA closure, phosphate release, and complex dissociation) to determine whether mutation of PCNA residues Arg-14, Lys-20, Arg-80, Lys-146, Arg-149, or Lys-217 to alanine affects the reaction mechanism. Contrary to earlier steady state analysis of these mutants (McNally, R., Bowman, G. D., Goedken, E. R., O'Donnell, M., and Kuriyan, J. (2010) Analysis of the role of PCNA-DNA contacts during clamp loading. BMC Struct. Biol. 10, 3), our pre-steady state data show that loss of single cationic residues can alter the rates of all DNA-linked steps in the reaction, as well as movement of PCNA on DNA. These results explain an earlier finding that individual arginines and lysines inside human PCNA are essential for polymerase δ processivity (Fukuda, K., Morioka, H., Imajou, S., Ikeda, S., Ohtsuka, E., and Tsurimoto, T. (1995) Structure-function relationship of the eukaryotic DNA replication factor, proliferating cell nuclear antigen

  14. Municipal consultants’ participation in building networks to support science teachers’ work

    DEFF Research Database (Denmark)

    Sillasen, Martin Krabbe; Valero, Paola

    2013-01-01

    of professional learning networks to assess the consultants’ opportunities and constraints in terms of participating in network development. The results indicate that the consultants’ roles in successful network formation is characterized by personal stable contacts within the science teacher community......This paper focuses particularly on the role of municipal science consultants in developing and maintaining network activities and connections among primary school science teachers. The hypothesis is that consultants play a crucial role in supporting strategic planning, and sustaining contacts...... and activities within professional learning networks. The research is framed by a project that involved 80 primary science teachers in 20 schools. The aim of the project was to develop network activities that facilitate sustainable change of the participating schools’ collective culture and practice of science...

  15. Is networking different with doctors working part-time? Differences in social networks of part-time and full-time doctors

    Directory of Open Access Journals (Sweden)

    Hingstman Lammert

    2008-10-01

    Full Text Available Abstract Background Part-time working is a growing phenomenon in medicine, which is expected to influence informal networks at work differently compared to full-time working. The opportunity to meet and build up social capital at work has offered a basis for theoretical arguments. Methods Twenty-eight teams of medical specialists in the Netherlands, including 226 individuals participated in this study. Interviews with team representatives and individual questionnaires were used. Data were gathered on three types of networks: relationships of consulting, communication and trust. For analyses, network and multilevel applications were used. Differences between individual doctors and between teams were both analysed, taking the dependency structure of the data into account, because networks of individual doctors are not independent. Teams were divided into teams with and without doctors working part-time. Results and Discussion Contrary to expectations we found no impact of part-time working on the size of personal networks, neither at the individual nor at the team level. The same was found regarding efficient reachability. Whereas we expected part-time doctors to choose their relations as efficiently as possible, we even found the opposite in intended relationships of trust, implying that efficiency in reaching each other was higher for full-time doctors. But we found as expected that in mixed teams with part-time doctors the frequency of regular communication was less compared to full-time teams. Furthermore, as expected the strength of the intended relationships of trust of part-time and full-time doctors was equally high. Conclusion From these findings we can conclude that part-time doctors are not aiming at efficiency by limiting the size of networks or by efficient reachability, because they want to contact their colleagues directly in order to prevent from communication errors. On the other hand, together with the growth of teams, we found

  16. Enhanced structural connectivity within a brain sub-network supporting working memory and engagement processes after cognitive training.

    Science.gov (United States)

    Román, Francisco J; Iturria-Medina, Yasser; Martínez, Kenia; Karama, Sherif; Burgaleta, Miguel; Evans, Alan C; Jaeggi, Susanne M; Colom, Roberto

    2017-05-01

    The structural connectome provides relevant information about experience and training-related changes in the brain. Here, we used network-based statistics (NBS) and graph theoretical analyses to study structural changes in the brain as a function of cognitive training. Fifty-six young women were divided in two groups (experimental and control). We assessed their cognitive function before and after completing a working memory intervention using a comprehensive battery that included fluid and crystallized abilities, working memory and attention control, and we also obtained structural MRI images. We acquired and analyzed diffusion-weighted images to reconstruct the anatomical connectome and we computed standardized changes in connectivity as well as group differences across time using NBS. We also compared group differences relying on a variety of graph-theory indices (clustering, characteristic path length, global and local efficiency and strength) for the whole network as well as for the sub-network derived from NBS analyses. Finally, we calculated correlations between these graph indices and training performance as well as the behavioral changes in cognitive function. Our results revealed enhanced connectivity for the training group within one specific network comprised of nodes/regions supporting cognitive processes required by the training (working memory, interference resolution, inhibition, and task engagement). Significant group differences were also observed for strength and global efficiency indices in the sub-network detected by NBS. Therefore, the connectome approach is a valuable method for tracking the effects of cognitive training interventions across specific sub-networks. Moreover, this approach allowsfor the computation of graph theoretical network metricstoquantifythetopological architecture of the brain networkdetected. The observed structural brain changes support the behavioral results reported earlier (see Colom, Román, et al., 2013

  17. A new configuration for multilevel converters with diode clamped topology

    DEFF Research Database (Denmark)

    Nami, A.; Zare, F.; Ledwich, G.

    2008-01-01

    points in this type of converter is dc-voltage control. In this paper, a novel multi output dc-dc converter connected to a diode clamped topology is presented. This converter, for a given duty cycles, is able to regulate the capacitor voltage to provide an appropriate input voltage for NPC regardless...

  18. Improved DNA clamps by stacking to adjacent nucleobases

    DEFF Research Database (Denmark)

    Fatthalla, M.I.; Pedersen, Erik Bjerregaard

    2012-01-01

    to the underlying non-planar base triplet in the formed triplex. This type of triplexes has a substantially higher thermal melting temperature which can be further improved by inserting locked nucleic acids (LNAs) in the Hoogsteen part of the clamp. An extremely high sensitivity to mismatches is observed...

  19. Beyond the patch clamp: nanotechnologies for intracellular recording.

    Science.gov (United States)

    Kruskal, Peter B; Jiang, Zhe; Gao, Teng; Lieber, Charles M

    2015-04-08

    The patch clamp is a fundamental tool for neuroscientists, offering insights that have shaped our understanding of the brain. Advances in nanotechnology suggest that the next generation of recording methods is now within reach. We discuss the complexity and future promise of applying nanoscience to neural recording. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. A piezoelectric vibration harvester based on clamped-guided beams

    NARCIS (Netherlands)

    Wang, Z.; Matova, S.; Elfrink, R.; Jambunathan, M.; Nooijer, C. de; Schaijk, R. van; Vullers, R.J.M.

    2012-01-01

    The paper addresses the design, modeling, fabrication and experimental results of a piezoelectric energy harvester based on clamped-guided beams. The design is featured by shorter mass displacement and higher reliability than cantilever beams. Two separate sets of capacitors allow exploiting both

  1. The cardiovascular effects of aortic clamping and unclamping

    African Journals Online (AJOL)

    presence of overt coronary artery disease. 2. The radius of the ventricle influences wall tension. In other words .... follows acute aortic constriction. This recovery of end-diastolic volume and pressure toward control .... concomitant valvular disease is beyond the scope of this manuscript. The circulation proximal to the clamp.

  2. Significance of the clamp-connection in the Basidiomycetes

    NARCIS (Netherlands)

    Furtado, João S.

    1966-01-01

    The cytogenetic phenomena affecting clamp-connection formation and the interpretation of this peculiar type of septum in the classification of the higher Basidiomycetes were reviewed from the literature and discussed. The cytogenetic data available are restricted to a small number of basidiomycetous

  3. Technical Note. A Clamped Bar Model for the Sompoton Vibrator

    National Research Council Canada - National Science Library

    Tee Hao Wong; Jedol Dayou; M.C.D. Ngu; Jackson H.W. Chang; Willey Y.H. Liew

    2013-01-01

    .... In this paper, the vibrator is modeled as a clamped bar with a uniformly distributed mass. By means of this model, the fundamental frequency is analyzed with the use of an equivalent single degree of freedom system (SDOF) and exact analysis...

  4. analytical bending solution of all clamped isotropic rectangular plate

    African Journals Online (AJOL)

    HP

    to the governing differential equation of the plate on Winkler foundation to obtain the deflection coefficient, . Numerical example was presented at the end to compare the results obtained by this method and those from earlier studies. The percentage difference obtained for central deflection of all clamped rectangular plate ...

  5. INOVASI SAMBUNGAN MEKANIS MENGGUNAKAN CLAMP BAJA UNTUK TULANGAN BETON

    Directory of Open Access Journals (Sweden)

    Parmo

    2015-12-01

    Full Text Available In the last few years, Indonesian urban growth has tends to be lead to the overground space. This was caused by the significant population increasement the lackness of land availability. The phenomenon is also marked with the increasing number of high-rise buildings and skyscrapers. However, high-rise buildings and skyscrapers have the potential dangers against earthquakes, even more Indonesia lay on an earthquake-prone areas. There are two main things that need to be considered in the planning of earthquake-resistant buildings, which is strength and ductility. Deformation capability and the connection strength between the reinforcement taken into consideration in the design of earthquake-resistant structures. From the steel clamp tensile test results for D13’s mechanical connection reinforcement, it gained 270.69 Mpa for yield strength, 351.45 MPa for ultimate tensile strength and 4757 kg for maximum load with 40% elongation. As for the D16’s mechanical connection reinforcement gained 217.80 MPa for yield strength, 327 605 MPa for ultimate tensile strength and 6717 kg for maximum load with 32% elongation. This study uses two pieces of steel clamp, but in order to obtain a better result then it need to be add more clamps while increasing the steel clamp material quality.

  6. A clamp-like biohybrid catalyst for DNA oxidation

    NARCIS (Netherlands)

    van Dongen, S.F.M.; Clerx, J.; Norgaard, K.; Bloemberg, T.G.; Cornelissen, Jeroen Johannes Lambertus Maria; Trakselis, M.A.; Nelson, S.W.; Benkovic, S.J.; Rowan, A.E.; Nolte, R.J.M.

    2013-01-01

    In processive catalysis, a catalyst binds to a substrate and remains bound as it performs several consecutive reactions, as exemplified by DNA polymerases. Processivity is essential in nature and is often mediated by a clamp-like structure that physically tethers the catalyst to its (polymeric)

  7. The problem of isotropic rectangular plate with four clamped edges

    Indian Academy of Sciences (India)

    ... received considerable attention because of its technical importance. This paper analyses the deflections of an isotropic rectangular clamped thin plates under uniformly distributed loads. A plate is called thin when its thickness is at least one order of magnitude smaller than the span of the plate. The bending and buckling.

  8. The phylogenetics of dynamics in DNA clamp proteins.

    Science.gov (United States)

    Balasubramaniam, Deepa; Komives, Elizabeth A

    2014-04-08

    Using HXMS to measure protein dynamics, Fang and colleagues (in this issue of Structure) probe the dynamics of processivity clamp proteins from all kingdoms of life. The proteins have similar structures but divergent sequences. Their results show conserved dynamics correlating with primary functions and divergent dynamics for divergent functions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. To imitate or differentiate: Cross-level identity work in an innovation network

    NARCIS (Netherlands)

    I Fortin (Israël); Oliver, D. (David)

    2016-01-01

    textabstractSurvival in global high-tech industries requires many organizations to participate in specialized innovation networks. However, sustained participation in these networks often proves more challenging than expected for organizations and their representatives, due to complex cross-level

  10. Return on Investment of a Work-Family Intervention: Evidence From the Work, Family, and Health Network.

    Science.gov (United States)

    Barbosa, Carolina; Bray, Jeremy W; Dowd, William N; Mills, Michael J; Moen, Phyllis; Wipfli, Brad; Olson, Ryan; Kelly, Erin L

    2015-09-01

    To estimate the return on investment (ROI) of a workplace initiative to reduce work-family conflict in a group-randomized 18-month field experiment in an information technology firm in the United States. Intervention resources were micro-costed; benefits included medical costs, productivity (presenteeism), and turnover. Regression models were used to estimate the ROI, and cluster-robust bootstrap was used to calculate its confidence interval. For each participant, model-adjusted costs of the intervention were $690 and company savings were $1850 (2011 prices). The ROI was 1.68 (95% confidence interval, -8.85 to 9.47) and was robust in sensitivity analyses. The positive ROI indicates that employers' investment in an intervention to reduce work-family conflict can enhance their business. Although this was the first study to present a confidence interval for the ROI, results are comparable with the literature.

  11. The need for scientists and judges to work together: regarding a new European network

    Science.gov (United States)

    Santosuosso, Amedeo; Redi, Carlo Alberto

    2003-01-01

    Is it always true to say that science is, by definition, universal whilst laws and the courts which apply them are a classic state and national expression? Yes and no. In recent years a new scenario has opened all over the world. Courts intervene more and more in disputes on matters related to scientific procedures in the biological field. In doing so the courts' decisions are affected by scientific issues and ways of reasoning and, on the other hand, affect the scientific field and its way of reasoning. While the old matter of bioethics was still alive and while judges were improving their skill in dealing with hard matters, like refusal of medical treatments, abortion, euthanasia et cetera, a new challenge appeared on the horizon, the challenge of biological sciences, and especially of the most troubled field of human genetics. A completely new awareness is developing among judges that they belong to an international judiciary community, as informal as it is real. Such a community is, even at an embryonic stage, sufficiently universal to be able to come together with the international scientific community. The authors maintain we are in urgent need for new interaction between judges and scientists and of new international means in the light of such cooperation. Judges and jurists need to become better acquainted with scientific questions and learn to exchange ideas with scientists. They also need to set themselves against the latters' conceptual systems and be willing to put their own up for discussion. A European Network for Life Sciences, Health and the Courts is taking its first steps, and judges and scientists are working side by side to tackle the new challenges. The provisional headquarters are located at the University of Pavia (I), Laboratorio di Biologia dello Sviluppo and Collegio Ghislieri (e-mail:. enlsc@unipv.it). ENLSC activity is inspired by the following idea: to be against science is as much antiscientific as to be acritically pro-science. PMID

  12. The need for scientists and judges to work together: regarding a new European network.

    Science.gov (United States)

    Santosuosso, Amedeo; Redi, Carlo Alberto

    2003-07-01

    Is it always true to say that science is, by definition, universal whilst laws and the courts which apply them are a classic state and national expression? Yes and no. In recent years a new scenario has opened all over the world. Courts intervene more and more in disputes on matters related to scientific procedures in the biological field. In doing so the courts' decisions are affected by scientific issues and ways of reasoning and, on the other hand, affect the scientific field and its way of reasoning. While the old matter of bioethics was still alive and while judges were improving their skill in dealing with hard matters, like refusal of medical treatments, abortion, euthanasia et cetera, a new challenge appeared on the horizon, the challenge of biological sciences, and especially of the most troubled field of human genetics. A completely new awareness is developing among judges that they belong to an international judiciary community, as informal as it is real. Such a community is, even at an embryonic stage, sufficiently universal to be able to come together with the international scientific community. The authors maintain we are in urgent need for new interaction between judges and scientists and of new international means in the light of such cooperation. Judges and jurists need to become better acquainted with scientific questions and learn to exchange ideas with scientists. They also need to set themselves against the latters' conceptual systems and be willing to put their own up for discussion. A European Network for Life Sciences, Health and the Courts is taking its first steps, and judges and scientists are working side by side to tackle the new challenges. The provisional headquarters are located at the University of Pavia (I), Laboratorio di Biologia dello Sviluppo and Collegio Ghislieri (e-mail: enlsc@unipv.it). ENLSC activity is inspired by the following idea: to be against science is as much antiscientific as to be acritically pro-science.

  13. The need for scientists and judges to work together: regarding a new European network

    Directory of Open Access Journals (Sweden)

    Santosuosso Amedeo

    2003-07-01

    Full Text Available Abstract Is it always true to say that science is, by definition, universal whilst laws and the courts which apply them are a classic state and national expression? Yes and no. In recent years a new scenario has opened all over the world. Courts intervene more and more in disputes on matters related to scientific procedures in the biological field. In doing so the courts' decisions are affected by scientific issues and ways of reasoning and, on the other hand, affect the scientific field and its way of reasoning. While the old matter of bioethics was still alive and while judges were improving their skill in dealing with hard matters, like refusal of medical treatments, abortion, euthanasia et cetera, a new challenge appeared on the horizon, the challenge of biological sciences, and especially of the most troubled field of human genetics. A completely new awareness is developing among judges that they belong to an international judiciary community, as informal as it is real. Such a community is, even at an embryonic stage, sufficiently universal to be able to come together with the international scientific community. The authors maintain we are in urgent need for new interaction between judges and scientists and of new international means in the light of such cooperation. Judges and jurists need to become better acquainted with scientific questions and learn to exchange ideas with scientists. They also need to set themselves against the latters' conceptual systems and be willing to put their own up for discussion. A European Network for Life Sciences, Health and the Courts is taking its first steps, and judges and scientists are working side by side to tackle the new challenges. The provisional headquarters are located at the University of Pavia (I, Laboratorio di Biologia dello Sviluppo and Collegio Ghislieri (e-mail:. enlsc@unipv.it. ENLSC activity is inspired by the following idea: to be against science is as much antiscientific as to be

  14. To clamp or not to clamp? Bladder management by suprapubic catheterization in patients with neurogenic bladder dysfunction.

    Science.gov (United States)

    Pannek, Jürgen; Göcking, Konrad; Bersch, Ulf

    2010-10-01

    In a small subset of patients with neurogenic lower urinary tract dysfunction, insertion of suprapubic catheters (SPC) cannot be avoided. If SPC has to be utilized, catheter clamping and anticholinergic medication are often recommended, but evidence supporting this view is scarce. We determined the influence of anticholinergic medication and catheter clamping on urodynamic parameters and the status of the urinary tract in patients with chronic suprapubic catheterization. In a retrospective study, the results of urodynamic testing, sonographic evaluations, and urinalyses of 85 patients with chronic (>1 year) suprapubic catheterization due to neurogenic bladder dysfunction were analyzed. The 51 male and 34 female patients (mean age 55 years) were managed with an SPC for 65.3 ± 48.0 months. Forty patients had an SPC for more than 60 months. Comparing the results before SPC insertion with the last follow-up examination, no significant differences in detrusor compliance and maximum detrusor pressure were detected, whereas bladder capacity significantly decreased. In three patients, alterations of the upper urinary tract were found. The results were not significantly different between the patients using anticholinergic medication and/or catheter clamping and those who did not. According to our study, routine use of anticholinergic medication and clamping of catheter does not seem to be necessary to preserve detrusor compliance and renal function in patients with SPC and neurogenic bladder dysfunction.

  15. The PluriNetWork: an electronic representation of the network underlying pluripotency in mouse, and its applications.

    Science.gov (United States)

    Som, Anup; Harder, Clemens; Greber, Boris; Siatkowski, Marcin; Paudel, Yogesh; Warsow, Gregor; Cap, Clemens; Schöler, Hans; Fuellen, Georg

    2010-12-10

    Analysis of the mechanisms underlying pluripotency and reprogramming would benefit substantially from easy access to an electronic network of genes, proteins and mechanisms. Moreover, interpreting gene expression data needs to move beyond just the identification of the up-/downregulation of key genes and of overrepresented processes and pathways, towards clarifying the essential effects of the experiment in molecular terms. We have assembled a network of 574 molecular interactions, stimulations and inhibitions, based on a collection of research data from 177 publications until June 2010, involving 274 mouse genes/proteins, all in a standard electronic format, enabling analyses by readily available software such as Cytoscape and its plugins. The network includes the core circuit of Oct4 (Pou5f1), Sox2 and Nanog, its periphery (such as Stat3, Klf4, Esrrb, and c-Myc), connections to upstream signaling pathways (such as Activin, WNT, FGF, BMP, Insulin, Notch and LIF), and epigenetic regulators as well as some other relevant genes/proteins, such as proteins involved in nuclear import/export. We describe the general properties of the network, as well as a Gene Ontology analysis of the genes included. We use several expression data sets to condense the network to a set of network links that are affected in the course of an experiment, yielding hypotheses about the underlying mechanisms. We have initiated an electronic data repository that will be useful to understand pluripotency and to facilitate the interpretation of high-throughput data. To keep up with the growth of knowledge on the fundamental processes of pluripotency and reprogramming, we suggest to combine Wiki and social networking software towards a community curation system that is easy to use and flexible, and tailored to provide a benefit for the scientist, and to improve communication and exchange of research results. A PluriNetWork tutorial is available at http://www.ibima.med.uni-rostock.de/IBIMA/PluriNetWork/.

  16. Pattern classification of working memory networks reveals differential effects of methylphenidate, atomoxetine, and placebo in healthy volunteers.

    Science.gov (United States)

    Marquand, Andre F; De Simoni, Sara; O'Daly, Owen G; Williams, Steven C R; Mourão-Miranda, Janaina; Mehta, Mitul A

    2011-05-01

    Stimulant and non-stimulant drugs can reduce symptoms of attention deficit/hyperactivity disorder (ADHD). The stimulant drug methylphenidate (MPH) and the non-stimulant drug atomoxetine (ATX) are both widely used for ADHD treatment, but their differential effects on human brain function remain unclear. We combined event-related fMRI with multivariate pattern recognition to characterize the effects of MPH and ATX in healthy volunteers performing a rewarded working memory (WM) task. The effects of MPH and ATX on WM were strongly dependent on their behavioral context. During non-rewarded trials, only MPH could be discriminated from placebo (PLC), with MPH producing a similar activation pattern to reward. During rewarded trials both drugs produced the opposite effect to reward, that is, attenuating WM networks and enhancing task-related deactivations (TRDs) in regions consistent with the default mode network (DMN). The drugs could be directly discriminated during the delay component of rewarded trials: MPH produced greater activity in WM networks and ATX produced greater activity in the DMN. Our data provide evidence that: (1) MPH and ATX have prominent effects during rewarded WM in task-activated and -deactivated networks; (2) during the delay component of rewarded trials, MPH and ATX have opposing effects on activated and deactivated networks: MPH enhances TRDs more than ATX, whereas ATX attenuates WM networks more than MPH; and (3) MPH mimics reward during encoding. Thus, interactions between drug effects and motivational state are crucial in defining the effects of MPH and ATX.

  17. Impact of Early Release of the IVC Clamp from Different IVC Clamping Maneuvers on Changes in Hemodynamic Parameters in Living Donor Liver Transplantation.

    Science.gov (United States)

    Shih, Tsung-Hsiao; Huang, Chia-Jung; Chen, Chao-Long; Cheng, Kwok-Wai; Wu, Shao-Chun; Yang, Sheng-Chun; Juang, Sin-Ei; Lee, Ying-En; Jawan, Bruno; Wang, Chih-Hsien

    2015-09-06

    BACKGROUND The aim of this study was to evaluate the impact of different methods of inferior vena cava (IVC) clamping and release of the cross clamp on hemodynamic parameters of recipients during living donor liver transplantation. MATERIAL AND METHODS Ninety-six adult living donor liver transplantation patients were divided into 3 groups according to cross-clamp of the IVC for all the hepatic vein and portal vein reconstruction (G1), cross-clamp of the IVC only for hepatic vein reconstruction (G2), and side-clamp of the IVC for hepatic vein reconstruction (G3). In G2 and G2, the reconstructed hepatic vein was clamped instead of the IVC for portal vein reconstruction. The hemodynamic parameters among groups were compared by 1-way ANOVA and the complications in each group were compared using the Kruskal-Wallis test. RESULTS Changes in percentage of MAP and CO in G3 were significantly less than that of G1 and G2 for hepatic vein reconstruction. Hemodynamic parameters of G2 and G3 normalized to pre-clamped values during portal vein reconstruction, while the hemodynamics of G1 remained unstable. CONCLUSIONS Hemodynamic changes were less pronounced in LT with side-clamp of the inferior cava vein versus total cross-clamp. Early release of the IVC clamp minimized the hemodynamic changes. There were no differences in terms of outcome (morbidity and mortality).

  18. Investigation of all-optical gain clamped erbium-doped amplifier in the presence of variable burst traffic

    Science.gov (United States)

    Zannin, M.; Mangeni, S.; Taccheo, S.; Ennser, K.; Barlet, P.; Careglio, D.

    2011-03-01

    Optical gain clamping is an all-optical method to control the gain of optical amplifiers. Recent results show that this technique is very robust and reduces impairments in amplification of typical traffic from optical burst (and packets) switching networks, where the traffic profile is very dynamic. Nevertheless, recent results have also shown that interplay between the characteristics of the optical gain clamping optical amplifier (OGC-OA) and particular traffic profiles may induce chaotic behavior caused by resonance in the OGC-OA lasing cavity. The aim of this investigation is to assess the impact of burst duration and inter-arrival time on these chaotic behavior cases. The investigation shows that the resonating frequency in which chaotic variation of the OGC-OA gain occurs is shifted - and even reduced - when the burst duration and inter-arrival time are changed. For this investigation, continuous trains of bursts were used, with fixed burst generation frequency throughout each case considered.

  19. Patch-Clamp Recording from Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes: Improving Action Potential Characteristics through Dynamic Clamp.

    Science.gov (United States)

    Verkerk, Arie O; Veerman, Christiaan C; Zegers, Jan G; Mengarelli, Isabella; Bezzina, Connie R; Wilders, Ronald

    2017-08-30

    Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) hold great promise for studying inherited cardiac arrhythmias and developing drug therapies to treat such arrhythmias. Unfortunately, until now, action potential (AP) measurements in hiPSC-CMs have been hampered by the virtual absence of the inward rectifier potassium current (IK1) in hiPSC-CMs, resulting in spontaneous activity and altered function of various depolarising and repolarising membrane currents. We assessed whether AP measurements in "ventricular-like" and "atrial-like" hiPSC-CMs could be improved through a simple, highly reproducible dynamic clamp approach to provide these cells with a substantial IK1 (computed in real time according to the actual membrane potential and injected through the patch-clamp pipette). APs were measured at 1 Hz using perforated patch-clamp methodology, both in control cells and in cells treated with all-trans retinoic acid (RA) during the differentiation process to increase the number of cells with atrial-like APs. RA-treated hiPSC-CMs displayed shorter APs than control hiPSC-CMs and this phenotype became more prominent upon addition of synthetic IK1 through dynamic clamp. Furthermore, the variability of several AP parameters decreased upon IK1 injection. Computer simulations with models of ventricular-like and atrial-like hiPSC-CMs demonstrated the importance of selecting an appropriate synthetic IK1. In conclusion, the dynamic clamp-based approach of IK1 injection has broad applicability for detailed AP measurements in hiPSC-CMs.

  20. Patch-Clamp Recording from Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes: Improving Action Potential Characteristics through Dynamic Clamp

    Science.gov (United States)

    Veerman, Christiaan C.; Zegers, Jan G.; Mengarelli, Isabella; Bezzina, Connie R.

    2017-01-01

    Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) hold great promise for studying inherited cardiac arrhythmias and developing drug therapies to treat such arrhythmias. Unfortunately, until now, action potential (AP) measurements in hiPSC-CMs have been hampered by the virtual absence of the inward rectifier potassium current (IK1) in hiPSC-CMs, resulting in spontaneous activity and altered function of various depolarising and repolarising membrane currents. We assessed whether AP measurements in “ventricular-like” and “atrial-like” hiPSC-CMs could be improved through a simple, highly reproducible dynamic clamp approach to provide these cells with a substantial IK1 (computed in real time according to the actual membrane potential and injected through the patch-clamp pipette). APs were measured at 1 Hz using perforated patch-clamp methodology, both in control cells and in cells treated with all-trans retinoic acid (RA) during the differentiation process to increase the number of cells with atrial-like APs. RA-treated hiPSC-CMs displayed shorter APs than control hiPSC-CMs and this phenotype became more prominent upon addition of synthetic IK1 through dynamic clamp. Furthermore, the variability of several AP parameters decreased upon IK1 injection. Computer simulations with models of ventricular-like and atrial-like hiPSC-CMs demonstrated the importance of selecting an appropriate synthetic IK1. In conclusion, the dynamic clamp-based approach of IK1 injection has broad applicability for detailed AP measurements in hiPSC-CMs. PMID:28867785

  1. Review: The lord of the rings: Structure and mechanism of the sliding clamp loader.

    Science.gov (United States)

    Kelch, Brian A

    2016-08-01

    Sliding clamps are ring-shaped polymerase processivity factors that act as master regulators of cellular replication by coordinating multiple functions on DNA to ensure faithful transmission of genetic and epigenetic information. Dedicated AAA+ ATPase machines called clamp loaders actively place clamps on DNA, thereby governing clamp function by controlling when and where clamps are used. Clamp loaders are also important model systems for understanding the basic principles of AAA+ mechanism and function. After nearly 30 years of study, the ATP-dependent mechanism of opening and loading of clamps is now becoming clear. Here I review the structural and mechanistic aspects of the clamp loading process, as well as comment on questions that will be addressed by future studies. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 532-546, 2016. © 2016 Wiley Periodicals, Inc.

  2. Four- year thyroidectomy procedures: Ligasure Vs. clamp & tie

    Directory of Open Access Journals (Sweden)

    Pazoki AR

    2010-01-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: The electrothermal bipolar vessel sealing system is an adjunct to the hemostatic technique, which has been successfully used in many abdominal operation, recently made available to thyroid surgery. The purpose of this was compare the outcomes of new hemostatic technique with traditional method of clamp and tie."n"nMethods: In this retrospective cross-sectional study has been done in surgery's wards of Milad & Rasul- Akram hospitals in Tehran, Iran. During three- year period between 2005-2008 all patients with different kind of pathology that need operation were assessed. Time duration of surgery and hospital stay and post surgery complication in two group, ligasure (n=45 and clamp & tie (n=145 were compared with each others."n"nResults: No difference was seen between two groups in time duration of surgery. Significant difference was seen in hospital stay and complications of surgery. Time of operation in Ligasure group was 132/22 minute and in clamp and tie group was 130/10 minute. There was found significant difference in duration of hospital stay and postoperative complication. Hypocalcemia were seen in two and 24 cases in Ligasure and Clamp & Tie group, respectively (p<0.05. Hospital stay was 2

  3. Using model-based functional MRI to locate working memory updates and declarative memory retrievals in the fronto-parietal network

    NARCIS (Netherlands)

    Borst, Jelmer P.; Anderson, John R.

    2013-01-01

    In this study, we used model-based functional MRI (fMRI) to locate two functions of the fronto-parietal network: declarative memory retrievals and updating of working memory. Because regions in the fronto-parietal network are by definition coherently active, locating functions within this network is

  4. Open partial nephrectomy with selective renal parenchymal control: a new reliable clamp.

    Science.gov (United States)

    Huyghe, Eric; Nohra, Joe; Leobon, Bertrand; El Khoury, Elias; Khedis, Mehdi; Soulié, Michel; Plante, Pierre

    2006-09-01

    We describe our experience of open partial nephrectomy with a parenchymal clamp, the Reni-Clamp, in 30 patients from January 2002 to May 2005. The mean operative and clamping time was 150 and 27 minutes, respectively, and the blood loss was 150 mL. The Reni-Clamp enabled us to perform partial nephrectomy safely in all cases of polar or external edge renal tumor.

  5. Hepatectomy for spontaneous rupture of hepatocellular carcinoma without portal triad clamping.

    Science.gov (United States)

    Wang, Zhi-Ming; Lu, Xin-Sheng; Qiu, Fu

    2017-10-01

    Hepatectomy without portal triad clamping may decrease the incidence of liver injury; however, the effects of hepatectomy without portal triad clamping in the treatment of spontaneous rupture of hepatocellular carcinoma (SRHCC) remain unclear. The aims of the present study were to evaluate the therapeutic value of hepatectomy without portal triad clamping in the treatment of patients with SRHCC. The present study retrospectively reviewed patients with SRHCC who received hepatectomy without portal triad clamping (non-clamping group) and the therapeutic efficacy was compared with that of 20 patients with SRHCC undergoing the same surgery in the presence of portal triad clamping (clamping group). Following hepatectomy, the non-clamping group exhibited a significantly lower incidence of acute liver failure compared with the clamping group (P0.05). At 1 week and 2 weeks after surgery, the non-clamping group exhibited significantly lower alanine aminotransferase, aspartate aminotransferase and total bilirubin serum levels compared with the clamping group (all Pportal triad clamping may decrease the incidence of liver injury and liver failure in patients with SRHCC, suggesting that it may be a safe and effective therapeutic strategy.

  6. MEMS-based clamp with a passive hold function for precision position retaining of micromanipulators

    NARCIS (Netherlands)

    Brouwer, Dannis Michel; de Jong, B.R.; de Boer, Meint J.; Jansen, Henricus V.; van Dijk, Johannes A.G.M.; van Dijk, Johannes; Krijnen, Gijsbertus J.M.; Soemers, Herman

    2009-01-01

    In this paper the design, modeling and fabrication of a precision MEMS-based clamp with arelatively large clamping force are presented. The purpose of the clamp is to mechanically fixa six-degree-of-freedom (DOF) MEMS-based sample manipulator (Brouwer et al J. Int. Soc. Precis. Eng. Nanotechnol.

  7. File list: Oth.ALL.20.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.20.Clamp.AllCell dm3 TFs and others Clamp All cell types SRX159172,SRX15917...0,SRX159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.ALL.20.Clamp.AllCell.bed ...

  8. File list: Oth.CeL.05.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  9. File list: Oth.CeL.20.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.CeL.20.Clamp.AllCell dm3 TFs and others Clamp Cell line SRX159172,SRX159170,SRX...159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.CeL.20.Clamp.AllCell.bed ...

  10. File list: Oth.ALL.05.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  11. File list: Oth.ALL.50.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  12. File list: Oth.CeL.50.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  13. File list: Oth.ALL.10.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  14. File list: Oth.CeL.10.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  15. Gigaseal formation in patch clamping with applications of nanotechnology

    CERN Document Server

    Malboubi, Majid

    2014-01-01

    This book presents an investigation of gigaseal formation using micro/nanotechnology. The aims of the book are twofold. First, it explains the mechanisms of gigaseal formation using the latest discoveries. Second, it provides practical techniques for frequent formation of high resistance seals. The formation of a high-resistance electrical seal, also known as a gigaseal, between a cell membrane and a glass micropipette tip is essential in patch-clamp experiments. Even though four decades have passed since the introduction of the patch-clamping technique by Neher and Sakmann, gigaseal formation remains an obstacle in developing the high-throughput ion channel screening systems required by the pharmaceutical industry. Here the authors share their latest methods for achieving gigaseal formation and describe techniques that are highly desirable at both research and industrial levels. Nanotechnology has been found to be a powerful tool for studying and modifying glass micropipettes and in tackling the problem of g...

  16. Patch Clamp Experiments under Conditions of Variable Graviy

    Science.gov (United States)

    Kohn, F. P. M.; Meissner, K.

    2013-02-01

    The cellular membrane is an intrinsic part of any cell. It has a complex composition of lipid molecules and proteins. The membrane is, among others, involved in excitation and signal transduction. Ion channels, as integral membrane proteins, play an important role. For the question of gravity sensitivity of biological systems, especially neuronal cells, ion channels are of high interest. Gravity might directly interact with the ion channel protein or it might change the thermodynamic membrane parameters, influencing the incorporated proteins indirectly. Detailed information about the effects of gravity on the function of single ion-channels can up to now only be acquired by electrophysiological approaches like the patch clamp technique. Today this technique is the preferentially used technique for single ion-channel studies. Consequently, experiments have been developed in recent years to investigate the interaction of gravity with single ion channel molecules utilizing the patch-clamp technology on different macro- and micro-gravity platforms.

  17. A networking approach to reduce academic and social isolation for junior doctors working in rural hospitals in India.

    Science.gov (United States)

    Vyas, R; Zachariah, A; Swamidasan, I; Doris, P; Harris, I

    2012-07-01

    Graduates from Christian Medical College (CMC) Vellore face many challenges while doing their service obligation in smaller hospitals, including academic and social isolation. To overcome these challenges, CMC aspired through its Fellowship in Secondary Hospital Medicine (FSHM), a 1-year blended on-site and distance-learning program, to provide academic and social support through networking for junior doctors working in rural areas. The purpose of this paper is to report the evaluation of the networking components of the FSHM program, with a focus on whether it succeeded in providing academic and social support for these junior doctors. A mixed method evaluation was done using written surveys for students and faculty and telephone interviews for students. Evidence for validity was gathered for the written survey. Criteria for validity were also applied for the qualitative data analysis. The major strengths of networking with faculty and peers identified were that it provided social support,, academic support through discussion about patient management problems and a variety of cases seen in the hospital, guidance on projects and reminders about deadlines. Recommendations for improvement included use of videoconferencing and Yahoo Groups. It is useful to incorporate networking into distance-learning educational programs for providing support to junior doctors working in rural hospitals.

  18. [Time of cord clamping and neonatal complications, a prospective study].

    Science.gov (United States)

    Rincón, D; Foguet, A; Rojas, M; Segarra, E; Sacristán, E; Teixidor, R; Ortega, A

    2014-09-01

    To assess the effects of early or late clamping of the umbilical cord in term newborns, assessing the levels of hemoglobin, hematocrit, and ferritin, and their correlation with some of the complications. A prospective study of healthy newborns at term or born by dystotic or eutocic delivery in our hospital between May 2009 until May 2010. Patients were assigned according to the time of clamping, group 1 (neonatal phototherapy or admission to the Intensive Care Unit and the hospital stay, were evaluated. A total of 242 patients were included: group 1 (g1=80), group 2 (g2=31) y group 3 (g3=131). The background maternal and neonatal characteristics were similar in all sets. The first test showed significant differences in ferritin levels in those infants with delayed clamping (g1: 111 mg/dl, g2: 125 mg/dl, g3: 173 mg/dl; p<0.01). In the second analysis the values of hemoglobin (g1: 17.3 g/dl, g2: 18.9 g/dl, g3: 19.2 g/dl; p<0.01), hematocrit (g1: 53.4%, g2: 58%, g3: 59%; p<0.01) and ferritin (g1: 254 mg/dl, g2: 254.7 mg/dl, g3: 313 mg/dl; p = 0.008) were statistically higher in this group. As regards complications, a significant increase was observed in the number of cases of polycythemia symptoms in group 3. The late cord clamping is associated with an increase in hematocrit, hemoglobin and ferritin at 48 hours of life, as well as an increased risk of polycythemia present with symptoms. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  19. Voltage Balancing Control of Diode-Clamped Multilevel Inverter

    Directory of Open Access Journals (Sweden)

    ŞCHIOP Adrian

    2013-10-01

    Full Text Available In this paper is developed a control scheme for mono-phase diode clamped inverter to achieve balancing voltages on inverter capacitors. First, it develops a control scheme without taking into account the need to balance voltage on two capacitors. It examines the effects on the output voltage inverter, and then it realizes two control schemes that will balance the voltages. The simulations of control schemes were performed in OrCAD Pspice.

  20. The Influence of EDM Parameters in Finishing Stage on Surface Quality of Hot Work Steel Using Artificial Neural Network

    Science.gov (United States)

    Amini, S.; Atefi, R.; Solhjoei, N.

    2011-01-01

    In this paper, the influence of different EDM parameters (pulse current, pulse voltage, pulse on-time , pulse off-time) in finishing stage on the surface quality (Ra) as a result of application copper electrode to a work piece( hot work steel DIN1.2344) has been investigated. Design of the experiment was chosen full factorial. Statistical analysis has been done and artificial neural network has been used to choose proper machining parameters and to reach certain surface roughness. Finally a hybrid model has been designed to reduce the artificial neural network errors. The experiment results indicated a good performance of proposed method in optimization of such a complex and non-linear problems.

  1. The Human Cytomegalovirus UL44 C Clamp Wraps around DNA

    Science.gov (United States)

    Komazin-Meredith, Gloria; Petrella, Robert J.; Santos, Webster L.; Filman, David J.; Hogle, James M.; Verdine, Gregory L.; Karplus, Martin; Coen, Donald M.

    2010-01-01

    Summary Processivity factors tether the catalytic subunits of DNA polymerases to DNA so that continuous synthesis of long DNA strands is possible. The human cytomegalovirus DNA polymerase subunit UL44 forms a C clamp-shaped dimer intermediate in structure between monomeric herpes simplex virus UL42, which binds DNA directly via a basic surface, and the trimeric sliding clamp PCNA, which encircles DNA. To investigate how UL44 interacts with DNA, calculations were performed in which a 12 bp DNA oligonucleotide was docked to UL44. The calculations suggested that UL44 encircles DNA, which interacts with basic residues both within the cavity of the C clamp and in flexible loops of UL44 that complete the “circle.” The results of mutational and crosslinking studies were consistent with this model. Thus, UL44 is a “hybrid” of UL42 and PCNA: its structure is intermediate between the two and its mode of interaction with DNA has elements of both. PMID:18682223

  2. Putting Gino's lesson to work: Actor-network theory, enacted humanity, and rehabilitation.

    Science.gov (United States)

    Abrams, Thomas; Gibson, Barbara E

    2016-02-01

    This article argues that rehabilitation enacts a particular understanding of "the human" throughout therapeutic assessment and treatment. Following Michel Callon and Vololona Rabeharisoa's "Gino's Lesson on Humanity," we suggest that this is not simply a top-down process, but is cultivated in the application and response to biomedical frameworks of human ability, competence, and responsibility. The emergence of the human is at once a materially contingent, moral, and interpersonal process. We begin the article by outlining the basics of the actor-network theory that underpins "Gino's Lesson on Humanity." Next, we elucidate its central thesis regarding how disabled personhood emerges through actor-network interactions. Section "Learning Gino's lesson" draws on two autobiographical examples, examining the emergence of humanity through rehabilitation, particularly assessment measures and the responses to them. We conclude by thinking about how rehabilitation and actor-network theory might take this lesson on humanity seriously. © The Author(s) 2016.

  3. From distributed resources to limited slots in multiple-item working memory: a spiking network model with normalization.

    Science.gov (United States)

    Wei, Ziqiang; Wang, Xiao-Jing; Wang, Da-Hui

    2012-08-15

    Recent behavioral studies have given rise to two contrasting models for limited working memory capacity: a "discrete-slot" model in which memory items are stored in a limited number of slots, and a "shared-resource" model in which the neural representation of items is distributed across a limited pool of resources. To elucidate the underlying neural processes, we investigated a continuous network model for working memory of an analog feature. Our model network fundamentally operates with a shared resource mechanism, and stimuli in cue arrays are encoded by a distributed neural population. On the other hand, the network dynamics and performance are also consistent with the discrete-slot model, because multiple objects are maintained by distinct localized population persistent activity patterns (bump attractors). We identified two phenomena of recurrent circuit dynamics that give rise to limited working memory capacity. As the working memory load increases, a localized persistent activity bump may either fade out (so the memory of the corresponding item is lost) or merge with another nearby bump (hence the resolution of mnemonic representation for the merged items becomes blurred). We identified specific dependences of these two phenomena on the strength and tuning of recurrent synaptic excitation, as well as network normalization: the overall population activity is invariant to set size and delay duration; therefore, a constant neural resource is shared by and dynamically allocated to the memorized items. We demonstrate that the model reproduces salient observations predicted by both discrete-slot and shared-resource models, and propose testable predictions of the merging phenomenon.

  4. Effective connectivity of AKT1-mediated dopaminergic working memory networks and pharmacogenetics of anti-dopaminergic treatment.

    Science.gov (United States)

    Tan, Hao Yang; Chen, Anthony G; Kolachana, Bhaskar; Apud, Jose A; Mattay, Venkata S; Callicott, Joseph H; Chen, Qiang; Weinberger, Daniel R

    2012-05-01

    Working memory is a limited capacity system that integrates and manipulates information across brief periods of time, engaging a network of prefrontal, parietal and subcortical brain regions. Genetic control of these heritable brain processes have been suggested by functional genetic variations influencing dopamine signalling, which affect prefrontal activity during complex working memory tasks. However, less is known about genetic control over component working memory cortical-subcortical networks in humans, and the pharmacogenetic implications of dopamine-related genes on cognition in patients receiving anti-dopaminergic drugs. Here, we examined predictions from basic models of dopaminergic signalling in cortical and cortical-subcortical circuitries implicated in dissociable working memory maintenance and manipulation processes. We also examined pharmacogenetic effects on cognition in the context of anti-dopaminergic drug therapy. Using dynamic causal models of functional magnetic resonance imaging in normal subjects (n = 46), we identified differentiated effects of functional polymorphisms in COMT, DRD2 and AKT1 genes on prefrontal-parietal and prefrontal-striatal circuits engaged during maintenance and manipulation, respectively. Cortical synaptic dopamine monitored by the COMT Val158Met polymorphism influenced prefrontal control of both parietal processing in working memory maintenance and striatal processing in working memory manipulation. DRD2 and AKT1 polymorphisms implicated in DRD2 signalling influenced only the prefrontal-striatal network associated with manipulation. In the context of anti-psychotic drugs, the DRD2 and AKT1 polymorphisms altered dose-response effects of anti-psychotic drugs on cognition in schizophrenia (n = 111). Thus, we suggest that genetic modulation of DRD2-AKT1-related prefrontal-subcortical circuits could at least in part influence cognitive dysfunction in psychosis and its treatment.

  5. Identification and Characterization of an Inside-Out Folding Intermediate of T4 Phage Sliding Clamp.

    Science.gov (United States)

    Singh, Manika Indrajit; Jain, Vikas

    2017-10-17

    Protein folding process involves formation of transiently occurring intermediates that are difficult to isolate and characterize. It is both necessary and interesting to characterize the structural conformations adopted by these intermediates, also called molten globules (MG), to understand protein folding. Here, we investigated the equilibrium (un)folding intermediate state of T4 phage gene product 45 (gp45, also known as DNA polymerase processivity factor or sliding clamp) obtained during chemical denaturation. We show that gp45 undergoes substantial conformational rearrangement during unfolding and forms an expanded dry-MG. By monitoring the fluorescence of tryptophans that were strategically introduced at various sites, we demonstrate that the urea-treated molecule has its surface residues flip inside the core, and closely placed residues move farther. We were also able to isolate and purify the MG form of gp45 in native condition (i.e., nondenaturing buffer, at physiological pH and temperature); characteristics of this purified molecule substantially match with urea-treated wild-type gp45. To the best of our knowledge, this is one of the few reports that demonstrate the isolation and purification of a protein folding intermediate in native condition. We believe that our work not only allows us to dissect the process of protein folding, but will also help in the designing of folding inhibitors against sliding clamps to treat a wide variety of diseases from bacterial infection to cancer, due to the vast presence of clamps in all the domains of life. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  6. Comparative Evaluation of Pulsewidth Modulation Strategies for Z-Source Neutral-Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Loh, P.C.; Blaabjerg, Frede; Wong, C.P.

    2007-01-01

    modulation (PWM) strategies for controlling the Z-source NPC inverter. While developing the PWM techniques, attention has been devoted to carefully derive them from a common generic basis for improved portability, easier implementation, and most importantly, assisting readers in understanding all concepts......Z-source neutral-point-clamped (NPC) inverter has recently been proposed as an alternative three-level buck-boost power conversion solution with an improved output waveform quality. In principle, the designed Z-source inverter functions by selectively "shooting through" its power sources, coupled...... to the inverter using two unique Z-source impedance networks, to boost the inverter three-level output waveform. Proper modulation of the new inverter would therefore require careful integration of the selective shoot-through process to the basic switching concepts to achieve maximal voltage-boost, minimal...

  7. Single stage buck-boost DC-AC neutral point clamped inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Andrew, A.

    2012-01-01

    This paper proposes a new single stage buck-boost DC-AC neutral point clamped inverter topology which integrates the cascaded configurations of recently introduced inductor-capacitor-capacitor-transformer impedance source network (by Adamowicz) and classic NPC configuration. As a consequence...... windings thus preventing the core from saturation; lowers the voltage stresses and power losses of inverter switches and reduces the sizes of filtering devices and as well as obtains better output performance compared to the original two-level Z-source inverters. A phase disposition pulse width modulation...... technique with minimum switching counts is implemented for the proposed topology. Simulation results as well as experimental results are presented to verify the behaviors of proposed configuration....

  8. Report of the National Heart, Lung, and Blood Institute Working Group: An Integrated Network for Congenital Heart Disease Research.

    Science.gov (United States)

    Pasquali, Sara K; Jacobs, Jeffrey P; Farber, Gregory K; Bertoch, David; Blume, Elizabeth D; Burns, Kristin M; Campbell, Robert; Chang, Anthony C; Chung, Wendy K; Riehle-Colarusso, Tiffany; Curtis, Lesley H; Forrest, Christopher B; Gaynor, William J; Gaies, Michael G; Go, Alan S; Henchey, Paul; Martin, Gerard R; Pearson, Gail; Pemberton, Victoria L; Schwartz, Steven M; Vincent, Robert; Kaltman, Jonathan R

    2016-04-05

    The National Heart, Lung, and Blood Institute convened a working group in January 2015 to explore issues related to an integrated data network for congenital heart disease research. The overall goal was to develop a common vision for how the rapidly increasing volumes of data captured across numerous sources can be managed, integrated, and analyzed to improve care and outcomes. This report summarizes the current landscape of congenital heart disease data, data integration methodologies used across other fields, key considerations for data integration models in congenital heart disease, and the short- and long-term vision and recommendations made by the working group. © 2016 American Heart Association, Inc.

  9. Report of the National Heart, Lung, and Blood Institute Working Group: An Integrated Network for Congenital Heart Disease Research

    Science.gov (United States)

    Pasquali, Sara K.; Jacobs, Jeffrey P.; Farber, Gregory K.; Bertoch, David; Blume, Elizabeth D.; Burns, Kristin M.; Campbell, Robert; Chang, Anthony C.; Chung, Wendy K.; Riehle-Colarusso, Tiffany; Curtis, Lesley H.; Forrest, Christopher B.; Gaynor, William J.; Gaies, Michael G.; Go, Alan S.; Henchey, Paul; Martin, Gerard R.; Pearson, Gail; Pemberton, Victoria L.; Schwartz, Steven M.; Vincent, Robert; Kaltman, Jonathan R.

    2016-01-01

    The National Heart, Lung, and Blood Institute convened a Working Group in January 2015 to explore issues related to an integrated data network for congenital heart disease (CHD) research. The overall goal was to develop a common vision for how the rapidly increasing volumes of data captured across numerous sources can be managed, integrated, and analyzed to improve care and outcomes. This report summarizes the current landscape of CHD data, data integration methodologies used across other fields, key considerations for data integration models in CHD, and the short- and long-term vision and recommendations made by the Working Group. PMID:27045129

  10. Investigation of the Dynamics of a Clamped-Clamped Microbeam Near the Third Mode Using a Partial Electrode

    KAUST Repository

    Masri, Karim M.

    2014-08-17

    We present an investigation of the dynamics of a clamped-clamped microbeam excited electrostatically near its third mode. To maximize the response at the third mode, a partial electrode configuration is utilized. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. A shooting method to find the periodic motion is utilized to generate frequency response curves. The curves show hardenining behavior and dynamic pull-in. We show that the dynamic amplitude of the partial configuration is higher than that of a full electrode configuration. These results are promising for the use of higher-order modes for mass detection and for ultra sensitive resonant sensors.

  11. Task positive and default mode networks during a working memory in children with primary monosymptomatic nocturnal enuresis and healthy controls.

    Science.gov (United States)

    Zhang, Kaihua; Ma, Jun; Lei, Du; Wang, Mengxing; Zhang, Jilei; Du, Xiaoxia

    2015-10-01

    Nocturnal enuresis is a common developmental disorder in children, and primary monosymptomatic nocturnal enuresis (PMNE) is the dominant subtype. This study investigated brain functional abnormalities that are specifically related to working memory in children with PMNE using function magnetic resonance imaging (fMRI) in combination with an n-back task. Twenty children with PMNE and 20 healthy children, group-matched for age and sex, participated in this experiment. Several brain regions exhibited reduced activation during the n-back task in children with PMNE, including the right precentral gyrus and the right inferior parietal lobule extending to the postcentral gyrus. Children with PMNE exhibited decreased cerebral activation in the task-positive network, increased task-related cerebral deactivation during a working memory task, and longer response times. Patients exhibited different brain response patterns to different levels of working memory and tended to compensate by greater default mode network deactivation to sustain normal working memory function. Our results suggest that children with PMNE have potential working memory dysfunction.

  12. Work Study Program Provides Revenue to School and Experience to Students: Cristo Rey Network, Nationwide

    Science.gov (United States)

    Stewart, Sarah

    2016-01-01

    Thirty-two Catholic Cristo Rey schools, all independently owned and operated, serve 9,953 students in grades 9-12. Cristo Rey calls itself "the largest network of high schools in the United States whose enrollment is limited to low-income youth." Students' average family income is $35,000; 97 percent are students of color. To fund the…

  13. The communicative ecology of Web 2.0 @ work : Social networking in the workspace

    NARCIS (Netherlands)

    Davison, R.M.; Ou, C.X.J.; Martinsons, M.G.; Zhao, A.Y.

    2014-01-01

    Social media have transformed social interactions and now look set to transform workplace communications. In this exploratory study, we investigate how employees use and get value from a variety of social networking technologies. The context of this research is 4 software firms located in China.

  14. The communicative ecology of Web 2.0 @work : Social networking in the workspace

    NARCIS (Netherlands)

    Davison, R.M.; Ou, C.X.J.; Martinsons, M.G.; Zhao, Y.; Hua, X.Q.; Du, R.; Adler, P.

    2013-01-01

    Social media have transformed social interactions and now look set to transform workplace communications. In this exploratory study, we investigate how employees use and get value from a variety of social networking technologies. The context of this research is 4 software firms located in China.

  15. CDC Tracking Network: Working Towards a Healthier Planet for Healthy People

    Centers for Disease Control (CDC) Podcasts

    2009-09-14

    This is an engaging video podcast geared to raise awareness of environmental public health and our nation's need for the Tracking Network.  Created: 9/14/2009 by National Center for Environmental Health (NCEH).   Date Released: 9/14/2009.

  16. neural network based model o work based model of an industrial oil

    African Journals Online (AJOL)

    eobe

    ropagation Algorithm (trainlm). The data; shows that data; shows that the simulated model the simulated model t outputs t outputs, with regression val with regression val with regression value of d to control the neural network model. , PID controller. ing processes. An additional node with ut (usually 1) is often added to the.

  17. Do Institutional Social Networks Work? Fostering a Sense of Community and Enhancing Learning

    Science.gov (United States)

    Hatzipanagos, Stylianos; John, Bernadette A.

    2017-01-01

    In this paper we report on the evaluation of an institutional social network (KINSHIP) whose aims were to foster an improved sense of community, enhance communication and serve as a space to model digital professionalism for students at King's College London, UK. Our evaluation focused on a pilot where students' needs with regard to the provision…

  18. Culture, Role and Group Work: A Social Network Analysis Perspective on an Online Collaborative Course

    Science.gov (United States)

    Stepanyan, Karen; Mather, Richard; Dalrymple, Roger

    2014-01-01

    This paper discusses the patterns of network dynamics within a multicultural online collaborative learning environment. It analyses the interaction of participants (both students and facilitators) within a discussion board that was established as part of a 3-month online collaborative course. The study employs longitudinal probabilistic social…

  19. Team performance in networked supervisory control of unmanned air vehicles: effects of automation, working memory, and communication content.

    Science.gov (United States)

    McKendrick, Ryan; Shaw, Tyler; de Visser, Ewart; Saqer, Haneen; Kidwell, Brian; Parasuraman, Raja

    2014-05-01

    Assess team performance within a net-worked supervisory control setting while manipulating automated decision aids and monitoring team communication and working memory ability. Networked systems such as multi-unmanned air vehicle (UAV) supervision have complex properties that make prediction of human-system performance difficult. Automated decision aid can provide valuable information to operators, individual abilities can limit or facilitate team performance, and team communication patterns can alter how effectively individuals work together. We hypothesized that reliable automation, higher working memory capacity, and increased communication rates of task-relevant information would offset performance decrements attributed to high task load. Two-person teams performed a simulated air defense task with two levels of task load and three levels of automated aid reliability. Teams communicated and received decision aid messages via chat window text messages. Task Load x Automation effects were significant across all performance measures. Reliable automation limited the decline in team performance with increasing task load. Average team spatial working memory was a stronger predictor than other measures of team working memory. Frequency of team rapport and enemy location communications positively related to team performance, and word count was negatively related to team performance. Reliable decision aiding mitigated team performance decline during increased task load during multi-UAV supervisory control. Team spatial working memory, communication of spatial information, and team rapport predicted team success. An automated decision aid can improve team performance under high task load. Assessment of spatial working memory and the communication of task-relevant information can help in operator and team selection in supervisory control systems.

  20. Impact of the whole-cell patch-clamp configuration on the pharmacological assessment of the hERG channel: trazodone as a case example.

    Science.gov (United States)

    Rodriguez-Menchaca, Aldo A; Ferrer, Tania; Navarro-Polanco, Ricardo A; Sanchez-Chapula, Jose A; Moreno-Galindo, Eloy G

    2014-01-01

    Voltage- and state-dependent blocks are important mechanisms by which drugs affect voltage-gated ionic channels. However, spontaneous (i.e. drug-free) time-dependent changes in the activation and inactivation of hERG and Na(+) channels have been reported when using conventional whole-cell patch-clamp in HEK-293 cells. hERG channels were heterologously expressed in HEK-293 cells and in Xenopus laevis oocytes. hERG current (IhERG) was recorded using both conventional and perforated whole-cell patch-clamp (HEK-293 cells), and two microelectrode voltage-clamp (Xenopus oocytes) in drug-free solution, and in the presence of the drug trazodone. In conventional whole-cell setup, we observed a spontaneous time-dependent hyperpolarizing shift in the activation curve of IhERG. Conversely, in perforated patch whole-cell (HEK-293 cells) or in two microelectrode voltage-clamp (Xenopus oocytes) activation curves of IhERG were very stable for periods ~50min. Voltage-dependent inactivation of IhERG was not significantly altered in the three voltage clamp configurations tested. When comparing voltage- and state-dependent effects of the antidepressant drug trazodone on IhERG, similar changes between the three voltage clamp configurations were observed as under drug-free conditions. The comparative analysis performed in this work showed that only under conventional whole-cell voltage-clamp conditions, a leftward shift in the activation curve of IhERG occurred, both in the presence and absence of drugs. These spontaneous time-dependent changes in the voltage activation gate of IhERG are a potential confounder in pharmacological studies on hERG channels expressed in HEK-293 cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Microsurgical Hepatic Artery Reconstruction Using Ikuta A-II Double Clamp.

    Science.gov (United States)

    Okochi, Masayuki; Okochi, Hiromi; Sakaba, Takao; Momiyama, Masanori; Ueda, Kazuki

    2017-05-01

    We performed hepatic artery (HA) reconstruction on 24 patients between January 2010 and October 2016. Six of 24 patients used an Ikuta type A-II vascular clamp (A-II group). The mean age was 38.0 years (range, 1-61 years). There was no blood leakage at the anastomosed site in any of the patients. No patients required an additional vascular clamp, and none developed HA thrombosis. Eighteen of 24 patients used a conventional vascular clamp. The mean age was 36.1 years (range, 1-65 years; conventional group). Sixteen of 18 patients required an additional vascular clamp due to blood leakage from the HA. There was no significant difference between the 2 groups in mean age or diameter of the recipient HA. However, there was a significant difference in the proportion of patients who required an additional vascular clamp (n clamp is an effective vascular clamp for reconstruction of the HA in living donor liver transplantation.

  2. Dynamic clamp as a tool to study the functional effects of individual membrane currents.

    Science.gov (United States)

    Berecki, Géza; Verkerk, Arie O; van Ginneken, Antoni C G; Wilders, Ronald

    2014-01-01

    Today, the patch-clamp technique is the main technique in electrophysiology to record action potentials or membrane current from isolated cells, using a patch pipette to gain electrical access to the cell. The common recording modes of the patch-clamp technique are current clamp and voltage clamp. In the current clamp mode, the current injected through the patch pipette is under control while the free-running membrane potential of the cell is recorded. Current clamp allows for measurements of action potentials that may either occur spontaneously or in response to an injected stimulus current. In voltage clamp mode, the membrane potential is held at a set level through a feedback circuit, which allows for the recording of the net membrane current at a given membrane potential.A less common configuration of the patch-clamp technique is the dynamic clamp. In this configuration, a specific non-predetermined membrane current can be added to or removed from the cell while it is in free-running current clamp mode. This current may be computed in real time, based on the recorded action potential of the cell, and injected into the cell. Instead of being computed, this current may also be recorded from a heterologous expression system such as a HEK-293 cell that is voltage-clamped by the free-running action potential of the cell ("dynamic action potential clamp"). Thus, one may directly test the effects of an additional or mutated membrane current, a synaptic current or a gap junctional current on the action potential of a patch-clamped cell. In the present chapter, we describe the dynamic clamp on the basis of its application in cardiac cellular electrophysiology.

  3. M. tuberculosis Sliding β-Clamp Does Not Interact Directly with the NAD+ -Dependent DNA Ligase

    Science.gov (United States)

    Kukshal, Vandna; Khanam, Taran; Chopra, Deepti; Singh, Nidhi; Sanyal, Sabyasachi; Ramachandran, Ravishankar

    2012-01-01

    The sliding β-clamp, an important component of the DNA replication and repair machinery, is drawing increasing attention as a therapeutic target. We report the crystal structure of the M. tuberculosis β-clamp (Mtbβ-clamp) to 3.0 Å resolution. The protein crystallized in the space group C2221 with cell-dimensions a = 72.7, b = 234.9 & c = 125.1 Å respectively. Mtbβ-clamp is a dimer, and exhibits head-to-tail association similar to other bacterial clamps. Each monomer folds into three domains with similar structures respectively and associates with its dimeric partner through 6 salt-bridges and about 21 polar interactions. Affinity experiments involving a blunt DNA duplex, primed-DNA and nicked DNA respectively show that Mtbβ-clamp binds specifically to primed DNA about 1.8 times stronger compared to the other two substrates and with an apparent Kd of 300 nM. In bacteria like E. coli, the β-clamp is known to interact with subunits of the clamp loader, NAD+ -dependent DNA ligase (LigA) and other partners. We tested the interactions of the Mtbβ-clamp with MtbLigA and the γ-clamp loader subunit through radioactive gel shift assays, size exclusion chromatography, yeast-two hybrid experiments and also functionally. Intriguingly while Mtbβ-clamp interacts in vitro with the γ-clamp loader, it does not interact with MtbLigA unlike in bacteria like E. coli where it does. Modeling studies involving earlier peptide complexes reveal that the peptide-binding site is largely conserved despite lower sequence identity between bacterial clamps. Overall the results suggest that other as-yet-unidentified factors may mediate interactions between the clamp, LigA and DNA in mycobacteria. PMID:22545130

  4. The PluriNetWork: an electronic representation of the network underlying pluripotency in mouse, and its applications.

    Directory of Open Access Journals (Sweden)

    Anup Som

    Full Text Available BACKGROUND: Analysis of the mechanisms underlying pluripotency and reprogramming would benefit substantially from easy access to an electronic network of genes, proteins and mechanisms. Moreover, interpreting gene expression data needs to move beyond just the identification of the up-/downregulation of key genes and of overrepresented processes and pathways, towards clarifying the essential effects of the experiment in molecular terms. METHODOLOGY/PRINCIPAL FINDINGS: We have assembled a network of 574 molecular interactions, stimulations and inhibitions, based on a collection of research data from 177 publications until June 2010, involving 274 mouse genes/proteins, all in a standard electronic format, enabling analyses by readily available software such as Cytoscape and its plugins. The network includes the core circuit of Oct4 (Pou5f1, Sox2 and Nanog, its periphery (such as Stat3, Klf4, Esrrb, and c-Myc, connections to upstream signaling pathways (such as Activin, WNT, FGF, BMP, Insulin, Notch and LIF, and epigenetic regulators as well as some other relevant genes/proteins, such as proteins involved in nuclear import/export. We describe the general properties of the network, as well as a Gene Ontology analysis of the genes included. We use several expression data sets to condense the network to a set of network links that are affected in the course of an experiment, yielding hypotheses about the underlying mechanisms. CONCLUSIONS/SIGNIFICANCE: We have initiated an electronic data repository that will be useful to understand pluripotency and to facilitate the interpretation of high-throughput data. To keep up with the growth of knowledge on the fundamental processes of pluripotency and reprogramming, we suggest to combine Wiki and social networking software towards a community curation system that is easy to use and flexible, and tailored to provide a benefit for the scientist, and to improve communication and exchange of research results. A

  5. CCITT Study Group XVIII Work Program 1981-1984; (Integrated Services Digital Network)

    Science.gov (United States)

    1981-06-01

    new transmission media including optical fibre, coaxial and radio systems will be used as appropriate. 10. Customer/network signalling Digital accese...Subscriber Line implemented using very wide bandwidth transmission media (such as fiber optic links) the possibility of the inclusion of video bandwidth...kind of noise does not present a great infuence on subjective osessments, while it is more important, for the overall noise object-ve =easurenent

  6. NetWorking News - A Method for Engaging Children Actively In Design

    DEFF Research Database (Denmark)

    Nørregaard, Peter; Dindler, Christian; Fritsch, Jonas

    2003-01-01

    For many years cooperative design was primarily concerned with the development of IT supported systems for professional users. However, the cooperative design approach can embrace other social practices such as children’s everyday life. At a methodological level there is no difference in designin...... the Networking News workshop, offers an opportunity to make first hand studies of children’s IT supported social activities in an informal classroom setting....

  7. Standardized Methods of Assessment of Individual’s Social Network in Social Work and Psychological Practice

    OpenAIRE

    Lifintsev D.V.; Lifintseva A.A.; Serykh A.B.

    2015-01-01

    This article is a theoretical overview of the main standardized techniques for assessment of the social relations of the individual. The study of these techniques allows professionals to get the basic information about the microsocial environment of people. Theoretical analysis shows that the study of the social network of an individual involves the analysis of its structure, composition and function of its components. Described and analyzed the most common techniques for asses...

  8. Design and control of a novel gastroscope intervention mechanism with circumferentially pneumatic-driven clamping function.

    Science.gov (United States)

    Li, Yanmin; Liu, Hao; Hao, Siwen; Li, Hongyi; Han, Jianda; Yang, Yunsheng

    2017-03-01

    Robot-assisted manipulation is promising for solving problems such as understaffing and the risk of infection in gastro-intestinal endoscopy. However, the commonly used friction rollers in few existing systems have a potential risk of deforming flexible endoscopes for non-uniform clamping. This paper presents a robotic system for a standard flexible endoscope and focuses on a novel gastroscope intervention mechanism (GIM), which provides circumferentially uniform clamping with an airbag. The GIM works with a relay-on mechanism in a way similar to manual operation. The shear stiffness of airbag and the critical slipping force (CSF) were analysed to determine the parameters of the airbag. A fuzzy PID controller was employed to realize a fast response and high accuracy of pneumatic actuation. Experiments were performed to evaluate the accuracy, stiffness and CSF. In vitro and in vivo animal experiments were also carried out. The GIM realized an accuracy of 0.025 ± 0.2 mm and -0.03 ± 0.25° for push-pull and rotation without delivery resistance. Under controlled to guarantee operating safety. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. A Clamped Be Window for the Dump of the HiRadMat Experiment at CERN

    CERN Document Server

    Delonca, M; Grenier, D; Maglioni, C; Sarrio Martinez, A

    2012-01-01

    At CERN, the High Radiation to Materials facility (HiRadMat) is designed to test accelerator components under the impact of high-intensity pulsed beams and will start operation in 2012. In this frame an LHC TED-type dump was installed at the end of the line, working in nitrogen overpressure, and a 254μm-thick beryllium window was placed as barrier between the inside of the dump and the external atmosphere. Because of the special loading conditions, a clamped window design was especially developed, optimized and implemented, the more standard welded window not being suitable for such loads. Considering then the clamping force and the applied differential pressures, the stresses on the window components were carefully evaluated thanks to empirical as well as numerical models, to guarantee the structural integrity of the beryllium foil. This paper reports on choices and optimizations that led to the final design, presenting also comparative results from different solutions and the detailed results for the adopt...

  10. A Clamped Be Window for the Dump of the HiRadMat Experiment at CERN

    CERN Document Server

    Delonca, M; Grenier, D; Maglioni, C; Sarrio Martinez, A

    2012-01-01

    At CERN, the High Radiation to Materials facility (HiRadMat) is designed to test accelerator components under the impact of high-intensity pulsed beams and will start operation in 2012. In this frame an LHC TED-type dump was installed at the end of the line, working in nitrogen over-pressure, and a 254μm-thick beryllium window was placed as barrier between the inside of the dump and the external atmosphere. Because of the special loading conditions, a clamped window design was especially developed, optimized and implemented, the more standard welded window not being suitable for such loads. Considering then the clamping force and the applied differential pressures, the stresses on the window components were carefully evaluated thanks to empirical as well as numerical models, to guarantee the structural integrity of the beryllium foil. This paper reports on choices and optimizations that led to the final design, presenting also comparative results from different solutions and the detailed results for the adop...

  11. Effects of Managers’ Work Motivation and Networking Activity on Their Reported Levels of External Red Tape

    NARCIS (Netherlands)

    Torenvlied, R.; Akkerman, A.

    2012-01-01

    This study brings together two perspectives on managers’ reported levels of red tape. The work motivation perspective explains how managers’ characteristics, such as work engagement (alienation) or commitment, affect their reported levels of red tape. The external control perspective explains how

  12. Understanding Internet-mediated research networks: can we really make them work?

    NARCIS (Netherlands)

    Moor, de Aldo; Blonk, van der Heico

    1998-01-01

    Besides being a distribution medium for up-to-date information, the Internet provides professional communities of users with an infrastructure forcollaborative work. An important problem, however, is that groups working over the Internet often fail to accomplish their goals. In this paper ourfocus

  13. High performance control strategy for single-phase three-level neutral-point-clamped traction four-quadrant converters

    DEFF Research Database (Denmark)

    Kejian, Song; Konstantinou, Georgios; Jing, Li

    2017-01-01

    Operational data from Chinese railways indicate a number of challenges for traction four-quadrant converter (4QC) control including low-order voltage and current harmonics and reference tracking. A control strategy for a single-phase three-level neutral-point-clamped 4QC employed in the electric...... in the network, the proposed control strategy improves the current tracking performance and reduces the line current harmonics, when compared with conventional control strategies. Experimental results, both under purely sinusoidal and distorted supply voltages, validate the effectiveness of the proposed control...

  14. Experimental study on the influence of clamping pressure on proton exchange membrane water electrolyzer (PEMWE) cell’s characteristics

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Cui, Xiaoti; Kær, Søren Knudsen

    at lower clamping pressure values at the same temperature and current density. Furthermore, early results have not shown any significant change in the amount of hydrogen crossing-over from cathode to anode and water from anode to cathode. This might be attributed to the membrane properties which might....... PEMWE cell splits water into hydrogen and oxygen when an electric current is passed through it. Electrical current forces the positively charged ions to migrate to negatively charged cathode, where hydrogen is reduced. Meanwhile, oxygen is produced at the anode side electrode and escapes as a gas...... with the circulating water. In the recent few years, PEMWE’s R&D has inched towards; operating conditions; such as increased operating temperature and cathode-anode high differential pressure operation, flow field design, stack development, and numerical modelling [2,3]. In this work the effect of clamping pressure...

  15. Fatigue Property of Open-Hole Steel Plates Influenced by Bolted Clamp-up and Hole Fabrication Methods

    Directory of Open Access Journals (Sweden)

    Zhi-Yu Wang

    2016-08-01

    Full Text Available Steel plates with open holes are commonly used in structural assemblies. The fatigue properties of such details are influenced by bolted clamp-up and hole fabrication methods. The fracture surface, stiffness degradation and fatigue life of test specimens are investigated in detail and compared with the contemporary test data. The analysis results show that the presence of draglines greatly influences the fatigue crack initiation at the open-hole cut by laser. The bolted clamp-up condition greatly enhances the stiffness and the fatigue life of the open-hole details. A discussion is also made from a comparison with the referred fatigue life of hole fabrication details, such as the influence of plate thickness and plasma cutting, drilling and oxy-fuel gas cutting, with the details studied herein. This work could enhance the understanding of the fatigue property and design of such details.

  16. A large-scale neural network model of the influence of neuromodulatory levels on working memory and behavior.

    Science.gov (United States)

    Avery, Michael C; Dutt, Nikil; Krichmar, Jeffrey L

    2013-01-01

    The dorsolateral prefrontal cortex (dlPFC), which is regarded as the primary site for visuospatial working memory in the brain, is significantly modulated by dopamine (DA) and norepinephrine (NE). DA and NE originate in the ventral tegmental area (VTA) and locus coeruleus (LC), respectively, and have been shown to have an "inverted-U" dose-response profile in dlPFC, where the level of arousal and decision-making performance is a function of DA and NE concentrations. Moreover, there appears to be a sweet spot, in terms of the level of DA and NE activation, which allows for optimal working memory and behavioral performance. When either DA or NE is too high, input to the PFC is essentially blocked. When either DA or NE is too low, PFC network dynamics become noisy and activity levels diminish. Mechanisms for how this is occurring have been suggested, however, they have not been tested in a large-scale model with neurobiologically plausible network dynamics. Also, DA and NE levels have not been simultaneously manipulated experimentally, which is not realistic in vivo due to strong bi-directional connections between the VTA and LC. To address these issues, we built a spiking neural network model that includes D1, α2A, and α1 receptors. The model was able to match the inverted-U profiles that have been shown experimentally for differing levels of DA and NE. Furthermore, we were able to make predictions about what working memory and behavioral deficits may occur during simultaneous manipulation of DA and NE outside of their optimal levels. Specifically, when DA levels were low and NE levels were high, cues could not be held in working memory due to increased noise. On the other hand, when DA levels were high and NE levels were low, incorrect decisions were made due to weak overall network activity. We also show that lateral inhibition in working memory may play a more important role in increasing signal-to-noise ratio than increasing recurrent excitatory input.

  17. Hyperinsulinemic clamp modulates milk fat globule lipid composition in goats.

    Science.gov (United States)

    Argov-Argaman, N; Mbogori, T; Sabastian, C; Shamay, A; Mabjeesh, S J

    2012-10-01

    We determined the effect of insulin on milk fatty acid (FA) and lipid composition in goats. Four dairy goats, 150 d in milk, were subjected to hyperinsulinemic clamp (treatment) or saline (control) infusion for 4d in a crossover design study. Composition and concentration of plasma and milk FA, triglycerides, phospholipids, sphingolipids, and cholesterol were determined. Mammary gland biopsies were taken at the end of each experimental period and lipogenic gene expression was determined. Plasma insulin was elevated 3.5-fold, whereas plasma glucose remained constant during the treatment period. Feed intake decreased by 26% and fat yield decreased by 17% relative to controls. No change in nonesterified FA concentration was found between controls and treatment. Compared with controls, insulin decreased yield of long-chain saturated FA by 14%. Milk concentration of long-chain FA was reduced by 3%, whereas that of medium-chain FA increased by 5% during the treatment compared with controls. Hyperinsulinemic clamps increased the yields of milk phospholipids by 9% and cholesterol by 16%, whereas it only tended to decrease triglyceride yields (by 11%). Hyperinsulinemic treatment resulted in compositional changes in the milk fat globule membrane, as reflected by 15 and 9% decreases in phosphatidylethanolamine and phosphatidylcholine concentrations, respectively. Lipogenic gene expression of acyl coenzyme A carboxylase, stearoyl coenzyme A desaturase, and FA synthase did not change, whereas lipoprotein lipase gene expression tended toward an increase in the treatment period compared with controls. Hyperinsulinemic clamps reduce the availability of long-chain FA, which are considered to originate from the diet and adipose lipolysis for milk lipid synthesis by the mammary gland of goats. Under these conditions, long-chain FA might be preferentially channeled to phospholipid rather than triglyceride synthesis, hence increasing phospholipid yields. Mechanisms determining FA

  18. Analysis of motion during the breast clamping phase of mammography.

    Science.gov (United States)

    Ma, Wang Kei; McEntee, Mark F; Mercer, Claire; Kelly, Judith; Millington, Sara; Hogg, Peter

    2016-01-01

    To measure paddle motion during the clamping phase of a breast phantom for a range of machine/paddle combinations. A deformable breast phantom was used to simulate a female breast. 12 mammography machines from three manufacturers with 22 flexible and 20 fixed paddles were evaluated. Vertical motion at the paddle was measured using two calibrated linear potentiometers. For each paddle, the motion in millimetres was recorded every 0.5 s for 40 s, while the phantom was compressed with 80 N. Independent t-tests were used to determine differences in paddle motion between flexible and fixed, small and large, GE Senographe Essential (General Electric Medical Systems, Milwaukee, WI) and Hologic Selenia Dimensions paddles (Hologic, Bedford, MA). Paddle tilt in the medial-lateral plane for each machine/paddle combination was calculated. All machine/paddle combinations demonstrate highest levels of motion during the first 10 s of the clamping phase. The least motion is 0.17 ± 0.05 mm/10 s (n = 20) and the most motion is 0.51 ± 0.15 mm/10 s (n = 80). There is a statistical difference in paddle motion between fixed and flexible (p motion and tilting, and the extent varied with machine and paddle sizes and types. This research suggests that image blurring will likely be clinically insignificant 4 s or more after the clamping phase commences.

  19. Prenatal drug exposure to illicit drugs alters working memory-related brain activity and underlying network properties in adolescence.

    Science.gov (United States)

    Schweitzer, Julie B; Riggins, Tracy; Liang, Xia; Gallen, Courtney; Kurup, Pradeep K; Ross, Thomas J; Black, Maureen M; Nair, Prasanna; Salmeron, Betty Jo

    2015-01-01

    The persistence of effects of prenatal drug exposure (PDE) on brain functioning during adolescence is poorly understood. We explored neural activation to a visuospatial working memory (VSWM) versus a control task using functional magnetic resonance imaging (fMRI) in adolescents with PDE and a community comparison group (CC) of non-exposed adolescents. We applied graph theory metrics to resting state data using a network of nodes derived from the VSWM task activation map to further explore connectivity underlying WM functioning. Participants (ages 12-15 years) included 47 adolescents (27 PDE and 20 CC). All analyses controlled for potentially confounding differences in birth characteristics and postnatal environment. Significant group by task differences in brain activation emerged in the left middle frontal gyrus (BA 6) with the CC group, but not the PDE group, activating this region during VSWM. The PDE group deactivated the culmen, whereas the CC group activated it during the VSWM task. The CC group demonstrated a significant relation between reaction time and culmen activation, not present in the PDE group. The network analysis underlying VSWM performance showed that PDE group had lower global efficiency than the CC group and a trend level reduction in local efficiency. The network node corresponding to the BA 6 group by task interaction showed reduced nodal efficiency and fewer direct connections to other nodes in the network. These results suggest that adolescence reveals altered neural functioning related to response planning that may reflect less efficient network functioning in youth with PDE. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Normal-Pressure Tests of Circular Plates with Clamped Edges

    Science.gov (United States)

    Mcpherson, Albert E; Ramberg, Walter; Levy, Samuel

    1942-01-01

    A fixture is described for making normal-pressure tests of flat plates 5 inches in diameter in which particular care was taken to obtain rigid clamping at the edges. Results are given for 19 plates, ranging in thickness form 0.015 to 0.072 inch. The center deflections and the extreme-fiber stresses at low pressures were found to agree with theoretical values; the center deflections at high pressures were 4 to 12 percent greater than the theoretical values. Empirical curves are derived of the pressure for the beginning of the permanent set as a function of the dimensions of the plate and the tensile properties of the material.

  1. Preliminary design work on a DSN VLBI correlator. [Deep Space Network

    Science.gov (United States)

    Lushbaugh, W. A.; Layland, J. W.

    1978-01-01

    The Deep Space Network is in the process of fielding high-density digital instrumentation recorders for support of the Pioneer Venus 1978 entry experiment and other related tasks. It has long been obvious that these recorders would also serve well as the recording medium for very long base interferometry (VLBI) experiments with relatively weak radio sources, provided that a suitable correlation processor for these tape recordings could be established. The overall design and current status of a VLBI correlator designed to mate with these tape recorders are described.

  2. Electrostatic Interactions at the Dimer Interface Stabilize the E. coli β Sliding Clamp.

    Science.gov (United States)

    Purohit, Anirban; England, Jennifer K; Douma, Lauren G; Tondnevis, Farzaneh; Bloom, Linda B; Levitus, Marcia

    2017-08-22

    Sliding clamps are ring-shaped oligomeric proteins that encircle DNA and associate with DNA polymerases for processive DNA replication. The dimeric Escherichia coli β-clamp is closed in solution but must adopt an open conformation to be assembled onto DNA by a clamp loader. To determine what factors contribute to the stability of the dimer interfaces in the closed conformation and how clamp dynamics contribute to formation of the open conformation, we identified conditions that destabilized the dimer and measured the effects of these conditions on clamp dynamics. We characterized the role of electrostatic interactions in stabilizing the β-clamp interface. Increasing salt concentration results in decreased dimer stability and faster subunit dissociation kinetics. The equilibrium dissociation constant of the dimeric clamp varies with salt concentration as predicted by simple charge-screening models, indicating that charged amino acids contribute to the remarkable stability of the interface at physiological salt concentrations. Mutation of a charged residue at the interface (Arg-103) weakens the interface significantly, whereas effects are negligible when a hydrophilic (Ser-109) or a hydrophobic (Ile-305) amino acid is mutated instead. It has been suggested that clamp opening by the clamp loader takes advantage of spontaneous opening-closing fluctuations at the clamp's interface, but our time-resolved fluorescence and fluorescence correlation experiments rule out conformational fluctuations that lead to a significant fraction of open states. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  3. Randomised trial of cord clamping and initial stabilisation at very preterm birth.

    Science.gov (United States)

    Duley, Lelia; Dorling, Jon; Pushpa-Rajah, Angela; Oddie, Sam J; Yoxall, Charles William; Schoonakker, Bernard; Bradshaw, Lucy; Mitchell, Eleanor J; Fawke, Joe Anthony

    2018-01-01

    For very preterm births, to compare alternative policies for umbilical cord clamping and immediate neonatal care. Parallel group randomised (1:1) trial, using sealed opaque numbered envelopes. Eight UK tertiary maternity units. 261 women expected to have a live birth before 32 weeks, and their 276 babies. Cord clamping after at least 2 min and immediate neonatal care with cord intact, or clamping within 20 s and immediate neonatal care after clamping. Intraventricular haemorrhage (IVH), death before discharge. 132 women (137 babies) were allocated clamping ≥2 min and neonatal care cord intact, and 129 (139) clamping ≤20 s and neonatal care after clamping; six mother-infant dyads were excluded (2, 4) as birth was after 35+6 weeks, one withdrew (death data only available) (0, 1). Median gestation was 28.9 weeks for those allocated clamping ≥2 min, and 29.2 for those allocated clamping ≤20 s. Median time to clamping was 120 and 11 s, respectively. 7 of 135 infants (5.2%) allocated clamping ≥2 min died and 15 of 135 (11.1%) allocated clamping ≤20 s; risk difference (RD) -5.9% (95% CI -12.4% to 0.6%). Of live births, 43 of 134 (32%) had IVH vs 47 of 132 (36%), respectively; RD -3.5% (-14.9% to 7.8%). There were no clear differences in other outcomes for infants or mothers. This is promising evidence that clamping after at least 2 min and immediate neonatal care with cord intact at very preterm birth may improve outcome; a large trial is urgently needed. ISRCTN 21456601. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. Fronto-parietal network oscillations reveal relationship between working memory capacity and cognitive control

    NARCIS (Netherlands)

    Gulbinaite, R.; van Rijn, H.; Cohen, M.X.

    2014-01-01

    Executive-attention theory proposes a close relationship between working memory capacity (WMC) and cognitive control abilities. However, conflicting results are documented in the literature, with some studies reporting that individual variations in WMC predict differences in cognitive control and

  5. The human dynamic clamp as a paradigm for social interaction.

    Science.gov (United States)

    Dumas, Guillaume; de Guzman, Gonzalo C; Tognoli, Emmanuelle; Kelso, J A Scott

    2014-09-02

    Social neuroscience has called for new experimental paradigms aimed toward real-time interactions. A distinctive feature of interactions is mutual information exchange: One member of a pair changes in response to the other while simultaneously producing actions that alter the other. Combining mathematical and neurophysiological methods, we introduce a paradigm called the human dynamic clamp (HDC), to directly manipulate the interaction or coupling between a human and a surrogate constructed to behave like a human. Inspired by the dynamic clamp used so productively in cellular neuroscience, the HDC allows a person to interact in real time with a virtual partner itself driven by well-established models of coordination dynamics. People coordinate hand movements with the visually observed movements of a virtual hand, the parameters of which depend on input from the subject's own movements. We demonstrate that HDC can be extended to cover a broad repertoire of human behavior, including rhythmic and discrete movements, adaptation to changes of pacing, and behavioral skill learning as specified by a virtual "teacher." We propose HDC as a general paradigm, best implemented when empirically verified theoretical or mathematical models have been developed in a particular scientific field. The HDC paradigm is powerful because it provides an opportunity to explore parameter ranges and perturbations that are not easily accessible in ordinary human interactions. The HDC not only enables to test the veracity of theoretical models, it also illuminates features that are not always apparent in real-time human social interactions and the brain correlates thereof.

  6. Development of a computational model on the neural activity patterns of a visual working memory in a hierarchical feedforward Network

    Science.gov (United States)

    An, Soyoung; Choi, Woochul; Paik, Se-Bum

    2015-11-01

    Understanding the mechanism of information processing in the human brain remains a unique challenge because the nonlinear interactions between the neurons in the network are extremely complex and because controlling every relevant parameter during an experiment is difficult. Therefore, a simulation using simplified computational models may be an effective approach. In the present study, we developed a general model of neural networks that can simulate nonlinear activity patterns in the hierarchical structure of a neural network system. To test our model, we first examined whether our simulation could match the previously-observed nonlinear features of neural activity patterns. Next, we performed a psychophysics experiment for a simple visual working memory task to evaluate whether the model could predict the performance of human subjects. Our studies show that the model is capable of reproducing the relationship between memory load and performance and may contribute, in part, to our understanding of how the structure of neural circuits can determine the nonlinear neural activity patterns in the human brain.

  7. A reduction clamp for an aiming component in associated acetabular fractures.

    Science.gov (United States)

    Wang, Zhang-Fu; Hong, Zheng-Hua; Wang, Mei-Zhen; Ruan, Jian-Wei; Wang, Wei; Pan, Wei-Bo

    2015-01-01

    The treatment of acetabular fractures is complex and requires specialized equipment. However, all currently available instruments have some disadvantages. A new reduction clamp that can firmly enable reduction and not hinder subsequent fixation procedures for some special fracture types is needed. In this study, we introduce a new acetabular clamp and its preliminary clinical application in three T-shaped acetabular fractures. This new clamp can successfully pull the posterior column back to the anterior column and firmly maintain the reduction. This clamp's aiming plate can facilitate the insertion of long lag screws. The clamp is also easy to assemble and use. This reduction clamp is a useful instrument that can facilitate open reduction and internal fixation of acetabular fractures.

  8. Linking Social Work Students to the Wider World via an Asynchronous Learning Network

    Science.gov (United States)

    Sarnoff, Susan

    2005-01-01

    Many course websites and much of the literature about them address the delivery of distance education. However, course websites are also useful for bringing the world to campus-based social work students, as well as for communicating between classes and making up for missed sessions. Course websites can incorporate synchronous or asynchronous…

  9. What Goes into High Educational and Occupational Achievement? Education, Brains, Hard Work, Networks, and Other Factors

    Science.gov (United States)

    Wai, Jonathan; Rindermann, Heiner

    2017-01-01

    There are many factors that go into high educational and occupational achievement, including hard work, motivation, and luck. But how important is talent? Specifically, how likely were global innovators and leaders intellectually talented or gifted when younger? This paper reviews retrospective data on multiple US samples (Total N = 11,745),…

  10. Emotion perception and executive control interact in the salience network during emotionally charged working memory processing

    NARCIS (Netherlands)

    Luo, Y.; Qin, S.; Fernandez, G.S.E.; Zhang, Y.; Klumpers, F.; Li, H.

    2014-01-01

    Processing of emotional stimuli can either hinder or facilitate ongoing working memory (WM); however, the neural basis of these effects remains largely unknown. Here we examined the neural mechanisms of these paradoxical effects by implementing a novel emotional WM task in an fMRI study. Twenty-five

  11. The Australian Collaborative Education Network Student Scholarship for Work-Integrated Learning 2010-2014

    Science.gov (United States)

    Moore, Keri; Ferns, Sonia; Peach, Deborah

    2015-01-01

    The increasing emphasis on embedding work-integrated learning (WIL) in the higher education curriculum has impacted on teaching and learning approaches. While the benefits of incorporating experiential learning in the student experience are recognized by all stakeholders, additional costs incurred by students have not been identified. At the same…

  12. Renal function is the same 6 months after robot-assisted partial nephrectomy regardless of clamp technique: analysis of outcomes for off-clamp, selective arterial clamp and main artery clamp techniques, with a minimum follow-up of 1 year.

    Science.gov (United States)

    Komninos, Christos; Shin, Tae Young; Tuliao, Patrick; Han, Woong Kyu; Chung, Byung Ha; Choi, Young Deuk; Rha, Koon Ho

    2015-06-01

    To compare the renal functional outcomes, with >1 year of follow-up, of patients who underwent robot-assisted partial nephrectomy (RAPN) performed with different clamping techniques. The peri-operative data of patients undergoing RAPN performed with different clamping techniques were retrospectively analysed (group 1: off-clamp, n = 23; group 2: selective clamp, n = 25; group 3: main artery clamp, n = 114). The main outcome measures were postoperative serum creatinine level, estimated glomerular filtration rate (eGFR) and percentage change in eGFR, the data for which were collected at periodic intervals during the first 12 months and annually thereafter, in addition to late eGFR value. Only patients with >1 year of follow-up were included in the analysis. The baseline characteristics of groups 2 and 3 were similar, while patients in group 1 had smaller sized tumours and lower tumour complexity. The median follow-up periods were 45 (group 1), 20 (group 2) and 47 (group 3) months. The median clamping times were 24.8 min in the main artery clamp and 18 min in the selective artery clamp groups. Group 2 had greater median blood loss volume (100 vs 500 vs 200 mL for groups 1, 2 and 3, respectively; P clamp procedure and tumour complexity score were predictive of normal renal function 7 days after surgery, while only baseline eGFR and age could predict it 1 year postoperatively. Off-clamp and selective artery clamp techniques result in superior short-term renal functional outcomes compared with the main artery clamp approach; however, after the 6th postoperative month, there were no significant differences regarding the functional outcome among the above surgical techniques, as long as the warm ischaemia time was 20-30 min. © 2014 The Authors BJU International © 2014 BJU International.

  13. Crystal structure of a DNA polymerase sliding clamp from a Gram-positive bacterium

    Directory of Open Access Journals (Sweden)

    O'Donnell Mike

    2006-01-01

    Full Text Available Abstract Background Sliding DNA clamps are processivity factors that are required for efficient DNA replication. DNA polymerases maintain proximity to nucleic acid templates by interacting with sliding clamps that encircle DNA and thereby link the polymerase enzyme to the DNA substrate. Although the structures of sliding clamps from Gram-negative bacteria (E. coli, eukaryotes, archaea, and T4-like bacteriophages are well-known, the structure of a sliding clamp from Gram-positive bacteria has not been reported previously. Results We have determined the crystal structure of the dimeric β subunit of the DNA polymerase III holoenzyme of Streptococcus pyogenes. The sliding clamp from this Gram-positive organism forms a ring-shaped dimeric assembly that is similar in overall structure to that of the sliding clamps from Gram-negative bacteria, bacteriophage T4, eukaryotes and archaea. The dimer has overall dimensions of ~90 Å × ~70 Å × ~25 Å with a central chamber that is large enough to accommodate duplex DNA. In comparison to the circular shape of other assemblies, the S. pyogenes clamp adopts a more elliptical structure. Conclusion The sequences of sliding clamps from S. pyogenes and E. coli are only 23% identical, making the generation of structural models for the S. pyogenes clamp difficult in the absence of direct experimental information. Our structure of the S. pyogenes β subunit completes the catalog of clamp structures from all the major sequence grouping of sliding clamps. The more elliptical rather than circular structure of the S. pyogenes clamp implies that the topological nature of encircling DNA, rather than a precise geometric shape, is the most conserved aspect for this family of proteins.

  14. Stepwise unfolding of titin under force-clamp atomic force microscopy

    OpenAIRE

    Andres F. Oberhauser; Hansma, Paul K.; Carrion-Vazquez, Mariano; Fernandez, Julio M.

    2001-01-01

    Here we demonstrate the implementation of a single-molecule force clamp adapted for use with an atomic force microscope. We show that under force-clamp conditions, an engineered titin protein elongates in steps because of the unfolding of its modules and that the waiting times to unfold are exponentially distributed. Force-clamp measurements directly measure the force dependence of the unfolding probability and readily captures the different mechanical stability of the...

  15. Cryogenic Clamp-on Ultrasonic Flowmeters using Single Crystal Piezoelectric Transducers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Clamp-on ultrasound cryogenic flowmeters using single crystal piezoelectric transducers are proposed to enable reliable, accurate cryogenic instrumentation needs in...

  16. COMPARISON OF EARLY AND DELAYED UMBILICAL CORD CLAMPING IN THE THIRD STAGE OF LABOUR

    Directory of Open Access Journals (Sweden)

    Tamara Serdinšek

    2015-09-01

    Full Text Available Background: Umbilical cord clamping in the third stage of labour is still controversial. Early cord clamping is defined as clamping at 10, 15, 30 or 60 seconds after delivery and delayed as clamping after 60 seconds or at 2-5 minutes after delivery, when the cord stops pulsating or when the placenta is visible within the birth canal. Early clamping is one of the three components of active management of the third stage of labour, which has been used widely in modern obstetrics during the last century. However, in some northern European countries, various parts of the USA and Canada and in developing countries physiological management is preferred.Conclusions: After publication of several trials describing advantages of delayed clamping, this has recently been progressively replacing early clamping. The most important advantages of delayed cord clamping are higher haemoglobin and ferritin levels, higher iron stores, lower incidence of iron deficiency anaemia, better cardiopulmonary adaptation, lower rate of respiratory distress syndrome, and longer duration of early breastfeeding in term neonates, while there is no increase in the incidence of postpartum haemorrhage. Delayed clamping seems to bring some advantages for preterm neonates as well. However, caution is still advised because of the potential adverse effects, especially polycythaemia with hyperviscosity, hyperbilirubinaemia and respiratory distress.

  17. Cognitive factors shape brain networks for auditory skills: spotlight on auditory working memory.

    Science.gov (United States)

    Kraus, Nina; Strait, Dana L; Parbery-Clark, Alexandra

    2012-04-01

    Musicians benefit from real-life advantages, such as a greater ability to hear speech in noise and to remember sounds, although the biological mechanisms driving such advantages remain undetermined. Furthermore, the extent to which these advantages are a consequence of musical training or innate characteristics that predispose a given individual to pursue music training is often debated. Here, we examine biological underpinnings of musicians' auditory advantages and the mediating role of auditory working memory. Results from our laboratory are presented within a framework that emphasizes auditory working memory as a major factor in the neural processing of sound. Within this framework, we provide evidence for music training as a contributing source of these abilities. © 2012 New York Academy of Sciences.

  18. Design of the Driving and Clamp Rotation Hydraulic Control System for the Heavy Load Forging Manipulator

    Directory of Open Access Journals (Sweden)

    Li Geqiang

    2015-01-01

    Full Text Available The manipulator was equipped with full hydraulic drive. We designed the hydraulic systems for the driving and clamping rotation. We used a fuzzy PID control strategy to design the electro-hydraulic proportional control system. We built a united simulation model based on the co-simulation of MATLAB/Simulink and AMEsim. A mathematical model of the system was also established. We did separate simulations of the system’s dynamic characteristics for fast forging and normal forging working conditions. The parameters were optimized. The field test shows that the steady-state error of the hydraulic system is small and the system response is fast. The system’s rapid response speed, high precision, and stability under heavy load were realized.

  19. Note: Decoupling design for high frequency piezoelectric ultrasonic transducers with their clamping connections

    Energy Technology Data Exchange (ETDEWEB)

    Wang, F. J., E-mail: wangfujun@tju.edu.cn; Liang, C. M.; Tian, Y. L.; Zhao, X. Y.; Zhang, D. W. [Tianjin Key Laboratory of Equipment Design and Manufacturing Technology, School of Mechanical Engineering, Tianjin University, Tianjin 300072 (China); Zhang, H. J. [Tianjin Key Laboratory of Modern Mechatronics Equipment Technology, School of Mechanical Engineering, Tianjin Polytechnic University, Tianjin 300387 (China)

    2015-12-15

    This work presents the flexure-mechanism based decoupling design between high frequency piezoelectric ultrasonic transducers and their clamping connections to improve ultrasonic energy transmission efficiency. The ring, prismatic beam, and circular notched hinge based flanges were presented, and the crucial geometric dimensions of the transducers with the flexure decoupling flanges were determined. Finite element analysis (FEA) was carried out to investigate the dynamic characteristics of the transducers. Finally, experiments were conducted to examine and verify the effects of the proposed decoupling flanges. FEA and experimental results show that smaller frequency deviations and larger tip displacement amplitudes have been achieved by using the transducers with the flexure flanges compared with the transducer with a rigid ring-type flange, and thus the ultrasonic transmission efficiency can be improved through the flexure flanges.

  20. A Transformerless Hybrid Filter Using a Three-Level Diode-Clamped PWM Converter

    Science.gov (United States)

    Hatada, Takaaki; Akagi, Hirofumi

    This paper deals with a transformerless hybrid active filter integrated into a medium-voltage three-phase diode rectifier used as the front end of an adjustable-speed motor drive. The hybrid filter is formed by a single LC filter tuned to the 7th-harmonic frequency per phase and a small-rated active filter based on a three-phase three-level diode-clamped PWM converter. A three-phase downscaled system rated at 400V and 15kW is designed, constructed, and tested to verify the filtering performance of the hybrid filter. Experimental results show that the current THD (total harmonic distortion) gets less than 5%, and that the voltage-balancing control proposed in this paper works properly even in transient states.

  1. A Color LED Driver Implemented by the Active Clamp Forward Converter

    Directory of Open Access Journals (Sweden)

    C.H. Chang

    2013-04-01

    Full Text Available Because light emitting diodes (LEDs have the advantages of dc working voltage, high luminescent efficiency, short ignition time, high reliability and pollution free, they have substituted for incandescent bulbs and fluorescent lamps gradually. In order to simplify circuit complexity, an active clamp forward converter with the sequential color display (SCD control is proposed to drive red, green and blue (RGB LED arrays. The proposed converter has zero-voltage switching (ZVS operations of both the main switch and the auxiliary switch, resulting in high system efficiency. Driving RGB LED arrays sequentially by one converter can save components and reduce cost significantly. Additionally, the pulse-width modulation (PWM control is applied to achieve a large chromaticity variation. The circuit operations are analyzed in detail and the circuit parameters are designed based on the practical considerations. Finally, an illustrative example is implemented to demonstrate the feasibility and validity of the proposed LED driver.

  2. Fronto-parietal network oscillations reveal relationship between working memory capacity and cognitive control

    OpenAIRE

    Rasa eGulbinaite; Hedderik evan Rijn; Cohen, Michael X

    2014-01-01

    Executive-attention theory proposes a close relationship between working memory capacity (WMC) and cognitive control abilities. However, conflicting results are documented in the literature, with some studies reporting that individual variations in WMC predict differences in cognitive control and trial-to-trial control adjustments (operationalized as the size of the congruency effect and congruency sequence effects, respectively), while others report no WMC-related differences. We hypothesize...

  3. Large-scale ecological networks do work in an ecologically complex biodiversity hotspot.

    Science.gov (United States)

    Samways, Michael J; Pryke, James S

    2016-03-01

    Landscape-scale ecological networks (ENs) are interconnected conservation corridors of high-quality habitat used to mitigate the adverse effects of landscape fragmentation and to connect with protected areas. The effectiveness of ENs for biodiversity conservation and ecosystem function has been challenged. Here we show how an extensive system of ENs of remnant historic land was put in place at a large spatial scale (>0.5 million ha) in a plantation forestry context in a global biodiversity hotspot in southern Africa. These ENs can maintain indigenous and historic compositional and functional biodiversity, even in an area prone to the challenging effects of El Niño. Furthermore, ENs increase the effective size of local protected areas. Socio-ecological solutions and financial viability are also integrated as part of practical implementation of ENs. By adopting a retrospective analytical approach, biodiversity is maintained while also having productive forestry, making this a powerful agro-ecological approach on a large conservation-significant scale.

  4. Caffeine impact on working memory-related network activation patterns in early stages of cognitive decline.

    Science.gov (United States)

    Haller, Sven; Montandon, Marie-Louise; Rodriguez, Cristelle; Moser, Dominik; Toma, Simona; Hofmeister, Jeremy; Giannakopoulos, Panteleimon

    2017-04-01

    Recent evidence indicates that caffeine may have a beneficial effect on cognitive decline and dementia. The current investigation assessed the effect of acute caffeine administration on working memory during the earliest stage of cognitive decline in elderly participants. The study includes consecutive 45 elderly controls and 18 individuals with mild cognitive impairment (MCI, 71.6 ± 4.7 years, 7 females). During neuropsychological follow-up at 18 months, 24 controls remained stable (sCON, 70.0 ± 4.3 years, 11 women), while the remaining 21 showed subtle cognitive deterioration (dCON, 73.4 ± 5.9 years, 14 women). All participants underwent an established 2-back working task in a crossover design of 200 mg caffeine versus placebo. Data analysis included task-related general linear model and functional connectivity tensorial independent component analysis. Working memory behavioral performances did not differ between sCON and dCON, while MCI was slower and less accurate than both control groups (p caffeine administration essentially restricted to the right hemisphere (p caffeine effects on brain activation and DMN deactivation. These complex fMRI patterns possibly reflect the instable status of these cases with intact behavioral performances despite already existing functional alterations in neocortical circuits.

  5. An ultra-fast EOD-based force-clamp detects rapid biomechanical transitions

    Science.gov (United States)

    Woody, Michael S.; Capitanio, Marco; Ostap, E. Michael; Goldman, Yale E.

    2017-08-01

    We assembled an ultra-fast infrared optical trapping system to detect mechanical events that occur less than a millisecond after a ligand binds to its filamentous substrate, such as myosin undergoing its 5 - 10 nm working stroke after actin binding. The instrument is based on the concept of Capitanio et al.1, in which a polymer bead-actin-bead dumbbell is held in two force-clamped optical traps. A force applied by the traps causes the filament to move at a constant velocity as hydrodynamic drag balances the applied load. When the ligand binds, the filament motion stops within 100 μs as the total force from the optical traps is transferred to the attachment. Subsequent translations signal active motions, such as the magnitude and timing of the motor's working stroke. In our instrument, the beads defining the dumbbell are held in independent force clamps utilizing a field-programmable gate array (FPGA) to update the trap beam positions at 250 kHz. We found that in our setup, acousto-optical deflectors (AODs) steering the beams were unsuitable for this purpose due to a slightly non-linear response in the beam intensity and deflection angle vs. the AOD ultra-sound wavelength, likely caused by low-amplitude standing acoustic waves in the deflectors. These aberrations caused instability in the force feedback loops leading to artefactual 20 nm jumps in position. This type of AOD non-linearity has been reported to be absent in electro-optical deflectors (EODs)2. We demonstrate that replacement of the AODs with EODs improves the performance of our instrument. Combining the superior beam-steering capability of the EODs, force acquisition via back-plane interferometry, and the dual high-speed FPGA-based feedback loops, we smoothly and precisely apply constant loads to study the dynamics of interactions between biological molecules such as actin and myosin.

  6. Effect of baseline cannabis use and working-memory network function on changes in cannabis use in heavy cannabis users: a prospective fMRI study.

    Science.gov (United States)

    Cousijn, Janna; Wiers, Reinout W; Ridderinkhof, K Richard; van den Brink, Wim; Veltman, Dick J; Goudriaan, Anna E

    2014-05-01

    Theoretical models of addiction suggest that a substance use disorder represents an imbalance between hypersensitive motivational processes and deficient regulatory executive functions. Working-memory (a central executive function) may be a powerful predictor of the course of drug use and drug-related problems. Goal of the current functional magnetic resonance imaging study was to assess the predictive power of working-memory network function for future cannabis use and cannabis-related problem severity in heavy cannabis users. Tensor independent component analysis was used to investigate differences in working-memory network function between 32 heavy cannabis users and 41 nonusing controls during an N-back working-memory task. In addition, associations were examined between working-memory network function and cannabis use and problem severity at baseline and at 6-month follow-up. Behavioral performance and working-memory network function did not significantly differ between heavy cannabis users and controls. However, among heavy cannabis users, individual differences in working-memory network response had an independent effect on change in weekly cannabis use 6 months later (ΔR(2) = 0.11, P = 0.006, f(2) = 0.37) beyond baseline cannabis use (ΔR(2) = 0.41) and a behavioral measure of approach bias (ΔR(2) = 0.18): a stronger network response during the N-back task was related to an increase in weekly cannabis use. These findings imply that heavy cannabis users requiring greater effort to accurately complete an N-back working-memory task have a higher probability of escalating cannabis use. Working-memory network function may be a biomarker for the prediction of course and treatment outcome in cannabis users. Copyright © 2013 Wiley Periodicals, Inc.

  7. Effects of overnight fasting on working memory-related brain network: an fMRI study.

    Science.gov (United States)

    Chechko, Natalia; Vocke, Sebastian; Habel, Ute; Toygar, Timur; Kuckartz, Lisa; Berthold-Losleben, Mark; Laoutidis, Zacharias G; Orfanos, Stelios; Wassenberg, Annette; Karges, Wölfram; Schneider, Frank; Kohn, Nils

    2015-03-01

    Glucose metabolism serves as the central source of energy for the human brain. Little is known about the effects of blood glucose level (BGL) on higher-order cognitive functions within a physiological range (e.g., after overnight fasting). In this randomized, placebo-controlled, double blind study, we assessed the impact of overnight fasting (14 h) on brain activation during a working memory task. We sought to mimic BGLs that occur naturally in healthy humans after overnight fasting. After standardized periods of food restriction, 40 (20 male) healthy participants were randomly assigned to receive either glucagon to balance the BGL or placebo (NaCl). A parametric fMRI paradigm, including 2-back and 0-back tasks, was used. Subclinically low BGL following overnight fasting was found to be linked to reduced involvement of the bilateral dorsal midline thalamus and the bilateral basal ganglia, suggesting high sensitivity of those regions to minimal changes in BGLs. Our results indicate that overnight fasting leads to physiologically low levels of glucose, impacting brain activation during working memory tasks even when there are no differences in cognitive performance. © 2014 Wiley Periodicals, Inc.

  8. Electrothermally actuated tunable clamped-guided resonant microbeams

    KAUST Repository

    Alcheikh, Nouha

    2017-06-11

    We present simulation and experimental investigation demonstrating active alteration of the resonant and frequency response behavior of resonators by controlling the electrothermal actuation method on their anchors. In-plane clamped-guided arch and straight microbeams resonators are designed and fabricated with V-shaped electrothermal actuators on their anchors. These anchors not only offer various electrothermal actuation options, but also serve as various mechanical stiffness elements that affect the operating resonance frequency of the structures. We have shown that for an arch, the first mode resonance frequency can be increased up to 50% of its initial value. For a straight beam, we have shown that before buckling, the resonance frequency decreases to very low values and after buckling, it increases up to twice of its initial value. These results can be promising for the realization of different wide–range tunable microresonator. The experimental results have been compared to multi-physics finite-element simulations showing good agreement among them.

  9. Electrothermally actuated tunable clamped-guided resonant microbeams

    Science.gov (United States)

    Alcheikh, N.; Hajjaj, A. Z.; Jaber, N.; Younis, M. I.

    2018-01-01

    We present simulation and experimental investigation demonstrating active alteration of the resonant and frequency response behavior of resonators by controlling the electrothermal actuation method on their anchors. In-plane clamped-guided arch and straight microbeams resonators are designed and fabricated with V-shaped electrothermal actuators on their anchors. These anchors not only offer various electrothermal actuation options, but also serve as various mechanical stiffness elements that affect the operating resonance frequency of the structures. We have shown that for an arch, the first mode resonance frequency can be increased up to 50% of its initial value. For a straight beam, we have shown that before buckling, the resonance frequency decreases to very low values and after buckling, it increases up to twice of its initial value. These results can be promising for the realization of different wide-range tunable microresonator. The experimental results have been compared to multi-physics finite-element simulations showing good agreement among them.

  10. Trans-Z-source Neutral Point Clamped inverter

    DEFF Research Database (Denmark)

    Mo, W.; Loh, P. C.; Li, D.

    2012-01-01

    Transformer based Z-source (trans-Z-source) inverters are recently proposed by extending the traditional Z-source inverter with higher buck-boost capability as well as reducing the passive components at the same time. Multi-Level Z-source inverters are single-stage topological solutions used...... for buck-boost energy conversion with all the favourable advantages of multi-level switching retained. This paper presents three-level trans-Z-source Neutral Point Clamped (NPC) inverter topology, which achieves both the advantages of trans-Z-source and three-level NPC inverter configuration. With proper...... modulation scheme, the three-level trans-Z-source inverter can function with minimum of six device commutations per half carrier cycle (same as the traditional buck NPC inverter), while maintaining to produce the designed volt-sec average and inductive voltage boosting at ac output terminals. The designed...

  11. Renal Vascular Clamp Placement: A Potential Cause of Incomplete Hilar Control during Partial Nephrectomy.

    Science.gov (United States)

    Tryon, David; Myklak, Kristene; Alsyouf, Muhannad; Conceicao, Carol; Peplinski, Brandon; Arenas, Javier L; Faaborg, Daniel; Ruckle, Herbert C; Baldwin, D Duane

    2016-03-01

    Previous benchtop studies have shown that robotic bulldog clamps provide incomplete vascular control of a Penrose drain. We determined the efficacy of robotic and laparoscopic bulldog clamps to ensure hemostasis on the human renal artery. The effect of clamp position on vascular control was also examined. Fresh human cadaveric renal arteries were used to determine the leak point pressure of 7 bulldog clamps from a total of 3 manufacturers. Five trials were performed per clamp at 4 locations, including the fulcrum, proximal, middle and distal positions. Comparison was done using the Kruskal-Wallis test with p clamps leaked at a pressure less than 215 mm Hg when applied at the proximal, middle or distal position. In general leak point pressure decreased as the artery was positioned more distal along the clamp. The exception was when the vessel was placed at the fulcrum position. At that position 80% to 100% of trials with the Klein laparoscopic, 100% with the Klein robotic (Klein Robotic, San Antonio, Texas) and 60% to 80% with the Scanlan robotic (Scanlan International, Saint Paul, Minnesota) clamp leaked at pressure below 215 mm Hg. Each vascular clamp adequately occluded flow at physiological pressure when placed at the proximal, middle or distal position. Furthermore, these results demonstrate that there is leakage at physiological pressure when the artery is placed at the fulcrum of certain clamp types. These results suggest that applying a bulldog clamp at the fulcrum could potentially lead to inadequate vessel occlusion and intraoperative bleeding. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  12. Euglycaemic glucose clamp: what it can and cannot do, and how to do it.

    Science.gov (United States)

    Heise, Tim; Zijlstra, Eric; Nosek, Leszek; Heckermann, Sascha; Plum-Mörschel, Leona; Forst, Thomas

    2016-10-01

    The hyperinsulinaemic-euglycaemic glucose clamp has always been regarded as the "gold standard" for the assessment of pharmacodynamic (PD) properties of insulin preparations; however, there has been controversy over a variety of methodogical details, such as study population, dosing time and the initial stabilization of blood glucose (BG) concentrations at the clamp target level, among clamp groups. As the impact of these details on PD results is unclear, the present review provides an overview of different methodological approaches for both the manual and the automated hyperinsulinaemic-euglycaemic glucose clamp. The advantages and limitations of several methodological details are discussed as well as the relevance of clamp results for the prediction of clinical outcomes. Overall, the best method strongly depends on the exact objective of the trial. If, for instance, duration of action is the primary objective, studies should be carried out in patients with type 1 diabetes to avoid any interference of endogenous insulin. This is less important for variables such as onset of action or early metabolic activity. The hyperinsulinaemic-euglycaemic glucose clamp has a high sensitivity to detect even minor differences between different insulin preparations. The practical relevance of potential differences, however, needs to be investigated in clinical studies. A major prerequisite for obtaining reliable glucose clamp results is the attainment of high clamp quality (i.e. keeping BG concentrations close to the clamp target throughout the experiments). Unfortunately, measures of clamp quality are often under-reported, as is the variability in PD profiles, although these might explain some unconfirmed extreme results obtained in a few clamp studies. © 2016 John Wiley & Sons Ltd.

  13. Social Networks, the ‘Work’ and Work Force of Chronic Illness Self-Management: A Survey Analysis of Personal Communities

    Science.gov (United States)

    Vassilev, Ivaylo; Rogers, Anne; Blickem, Christian; Brooks, Helen; Kapadia, Dharmi; Kennedy, Anne; Sanders, Caroline; Kirk, Sue; Reeves, David

    2013-01-01

    Self-management support forms a central aspect of chronic Illness management nationally and globally. Evidence for the success of self-management support has mainly focussed on individually-centred outcomes of behavioural change. While it is recognised that social network members play an important role there is currently a gap in knowledge regarding who provides what type of support and under what circumstances. This is relevant for understanding the division of labour and the meeting of needs for those living with a long-term condition. We therefore took a network approach to explore self-management support conceptualising it as types of illness ‘work’ undertaken within peoples’ social networks. 300 people from deprived areas and with chronic illnesses took part in a survey conducted in 2010 in the North West of England. A concentric circles diagram was used as a research tool with which participants identified 2,544 network members who contributed to illness management. The results provide an articulation of how social network members are substantially involved in illness management. Whilst partners and close family make the highest contributions there is evidence of inputs from a wide range of relationships. Network member characteristics (type of relationship, proximity, frequency of contact) impact on the amount of illness work undertaken in peoples’ networks. In networks with ‘no partner’ other people tend to contribute more in the way of illness related work than in networks with a partner. This indicates a degree of substitutability between differently constituted networks, and that the level and type of input by different members of a network might change according to circumstances. A network perspective offers an opportunity to redress the balance of an exclusively individual focus on self-management because it addresses the broader set of contributions and resources available to people in need of chronic illness management and support. PMID

  14. Relationship between working-memory network function and substance use: a 3-year longitudinal fMRI study in heavy cannabis users and controls.

    Science.gov (United States)

    Cousijn, Janna; Vingerhoets, Wilhelmina A M; Koenders, Laura; de Haan, Lieuwe; van den Brink, Wim; Wiers, Reinout W; Goudriaan, Anna E

    2014-03-01

    Deficient executive functions play an important role in the development of addiction. Working-memory may therefore be a powerful predictor of the course of drug use, but chronic substance use may also impair working-memory. The aim of this 3-year longitudinal neuro-imaging study was to investigate the relationship between substance use (e.g. alcohol, cannabis, nicotine, illegal psychotropic drugs) and working-memory network function over time in heavy cannabis users and controls. Forty-nine participants performed an n-back working-memory task at baseline and at 3-year follow-up. At follow-up, there were 22 current heavy cannabis users, 4 abstinent heavy cannabis users and 23 non-cannabis-using controls. Tensor-independent component analysis (Tensor-ICA) was used to investigate individual differences in working-memory network functionality over time. Within the group of cannabis users, cannabis-related problems remained stable, whereas alcohol-related problems, nicotine dependence and illegal psychotropic substance use increased over time. At both measurements, behavioral performance and network functionality during the n-back task did not differ between heavy cannabis users and controls. Although n-back accuracy improved, working-memory network function remained stable over time. Within the group of cannabis users, working-memory network functionality was not associated with substance use. These results suggest that sustained moderate to heavy levels of cannabis, nicotine, alcohol and illegal psychotropic substance use do not change working-memory network functionality. Moreover, baseline network functionality did not predict cannabis use and related problems three years later, warranting longitudinal studies in more chronic or dependent cannabis users. © 2013 Society for the Study of Addiction.

  15. Developing neuroimaging phenotypes of the default mode network in PTSD: integrating the resting state, working memory, and structural connectivity.

    Science.gov (United States)

    Philip, Noah S; Carpenter, S Louisa; Sweet, Lawrence H

    2014-07-01

    Complementary structural and functional neuroimaging techniques used to examine the Default Mode Network (DMN) could potentially improve assessments of psychiatric illness severity and provide added validity to the clinical diagnostic process. Recent neuroimaging research suggests that DMN processes may be disrupted in a number of stress-related psychiatric illnesses, such as posttraumatic stress disorder (PTSD). Although specific DMN functions remain under investigation, it is generally thought to be involved in introspection and self-processing. In healthy individuals it exhibits greatest activity during periods of rest, with less activity, observed as deactivation, during cognitive tasks, e.g., working memory. This network consists of the medial prefrontal cortex, posterior cingulate cortex/precuneus, lateral parietal cortices and medial temporal regions. Multiple functional and structural imaging approaches have been developed to study the DMN. These have unprecedented potential to further the understanding of the function and dysfunction of this network. Functional approaches, such as the evaluation of resting state connectivity and task-induced deactivation, have excellent potential to identify targeted neurocognitive and neuroaffective (functional) diagnostic markers and may indicate illness severity and prognosis with increased accuracy or specificity. Structural approaches, such as evaluation of morphometry and connectivity, may provide unique markers of etiology and long-term outcomes. Combined, functional and structural methods provide strong multimodal, complementary and synergistic approaches to develop valid DMN-based imaging phenotypes in stress-related psychiatric conditions. This protocol aims to integrate these methods to investigate DMN structure and function in PTSD, relating findings to illness severity and relevant clinical factors.

  16. Failed cooperative, but not competitive, interaction between large-scale brain networks impairs working memory in schizophrenia.

    Science.gov (United States)

    Pu, W; Luo, Q; Palaniyappan, L; Xue, Z; Yao, S; Feng, J; Liu, Z

    2016-04-01

    A large-scale network named the default mode network (DMN) dynamically cooperates and competes with an external attention system (EAS) to facilitate various cognitive functioning that is prominently impaired in schizophrenia. However, it is unclear whether the cognitive deficit in schizophrenia is related to the disrupted competition and/or cooperation between these two networks. A total of 35 schizophrenia patients and 30 healthy controls were scanned using gradient-echo echo-planar imaging during n-back working memory (WM) processing. Brain activities of the DMN and EAS were measured using general linear modelling of the functional magnetic resonance imaging data. Dynamic interaction between the DMN and EAS was decomposed into two directions using Granger causality analysis. We observed a significant failure of DMN suppression in patients with schizophrenia, which was significantly related to WM/attentional deficit. Granger causality modelling showed that in healthy controls, while the EAS inhibitorily influenced the DMN, the DMN exerted an 'excitatory' or cooperative influence back on the EAS, especially in those with lower WM accuracy. In schizophrenia, this 'excitatory' DMN→EAS influence within the reciprocal EAS-DMN loop was significantly reduced, especially in patients with WM/attentional deficit. The dynamic interaction between the DMN and EAS is likely to be comprised of both competitive and cooperative influences. In healthy controls, both the 'inhibitory' EAS→DMN interaction and 'excitatory' DMN→EAS interaction are correlated with WM performance. In schizophrenia, reduced 'cooperative' influence from the DMN to dorsal nodes of the EAS occurs in the context of non-suppression of the DMN and may form a possible pathophysiological substrate of WM deficit and attention disorder.

  17. The North Texas aerospace manufacturing and aviation industries: An explanatory case study of school-to-work collaborative networks

    Science.gov (United States)

    Miller, Cynthia Ann

    The purpose of this study is to explore how educators, business partners and facilitators developed ties or networks to initiate a school-to-work collaboration to prepare students for jobs and careers in the aerospace manufacturing and aviation industries. There is growing concern about preparing a future workforce supply in these industries in North Texas. Workforce projections call for 8000 additional jobs between 2010 and 2020 (North Central Texas Council of Governments, 2013). Collaboration is recognized as a valuable asset to connect disjointed segments within the K-16 trajectory. This study explores the contradiction between the stated need for collaborative strategies and the inability of stakeholders attempting to collaborate across organizational and institutional boundaries to sustain these connections. Through the lens of networking theory, the roles of facilitators and the operation of networks and ties between and among partners are investigated. Ten participants in a high school curriculum development project were interviewed, representing a business, community college, and K-12 education. Data analysis revealed findings associated with three major themes: facilitation, project activity and relationships. Nine individuals were identified as facilitators, and facilitators were perceived as helping the project move forward. Project activity benefited from the structured curriculum development process. Although relationships characterized by strong ties helped start the project, weak ties predominated among project participants. Implications for theory include the need for more knowledge about facilitator roles and group dynamics. Further research about the functioning of weak and strong ties and facilitator skill sets relating to collaborative leadership would be valuable. Implications for practice include capturing lessons learned to apply to other industries, and overtly acknowledging the existence and importance of facilitators.

  18. Opposite modulation of brain functional networks implicated at low vs. high demand of attention and working memory.

    Directory of Open Access Journals (Sweden)

    Jiansong Xu

    Full Text Available Functional magnetic resonance imaging (fMRI studies indicate that the brain organizes its activity into multiple functional networks (FNs during either resting condition or task-performance. However, the functions of these FNs are not fully understood yet.To investigate the operation of these FNs, spatial independent component analysis (sICA was used to extract FNs from fMRI data acquired from healthy participants performing a visual task with two levels of attention and working memory load. The task-related modulations of extracted FNs were assessed. A group of FNs showed increased activity at low-load conditions and reduced activity at high-load conditions. These FNs together involve the left lateral frontoparietal cortex, insula, and ventromedial prefrontal cortex. A second group of FNs showed increased activity at high-load conditions and reduced activity at low-load conditions. These FNs together involve the intraparietal sulcus, frontal eye field, lateral frontoparietal cortex, insula, and dorsal anterior cingulate, bilaterally. Though the two groups of FNs showed opposite task-related modulations, they overlapped extensively at both the lateral and medial frontoparietal cortex and insula. Such an overlap of FNs would not likely be revealed using standard general-linear-model-based analyses.By assessing task-related modulations, this study differentiated the functional roles of overlapping FNs. Several FNs including the left frontoparietal network are implicated in task conditions of low attentional load, while another set of FNs including the dorsal attentional network is implicated in task conditions involving high attentional demands.

  19. Phenotypes of dnaXE145A Mutant Cells Indicate that the Escherichia coli Clamp Loader Has a Role in the Restart of Stalled Replication Forks.

    Science.gov (United States)

    Flåtten, Ingvild; Helgesen, Emily; Pedersen, Ida Benedikte; Waldminghaus, Torsten; Rothe, Christiane; Taipale, Riikka; Johnsen, Line; Skarstad, Kirsten

    2017-12-15

    The Escherichia colidnaXE145A mutation was discovered in connection with a screen for multicopy suppressors of the temperature-sensitive topoisomerase IV mutation parE10 The gene for the clamp loader subunits τ and γ, dnaX, but not the mutant dnaXE145A , was found to suppress parE10(Ts) when overexpressed. Purified mutant protein was found to be functional in vitro, and few phenotypes were found in vivo apart from problems with partitioning of DNA in rich medium. We show here that a large number of the replication forks that initiate at oriC never reach the terminus in dnaXE145A mutant cells. The SOS response was found to be induced, and a combination of the dnaXE145A mutation with recBC and recA mutations led to reduced viability. The mutant cells exhibited extensive chromosome fragmentation and degradation upon inactivation of recBC and recA, respectively. The results indicate that the dnaXE145A mutant cells suffer from broken replication forks and that these need to be repaired by homologous recombination. We suggest that the dnaX-encoded τ and γ subunits of the clamp loader, or the clamp loader complex itself, has a role in the restart of stalled replication forks without extensive homologous recombination.IMPORTANCE The E. coli clamp loader complex has a role in coordinating the activity of the replisome at the replication fork and loading β-clamps for lagging-strand synthesis. Replication forks frequently encounter obstacles, such as template lesions, secondary structures, and tightly bound protein complexes, which will lead to fork stalling. Some pathways of fork restart have been characterized, but much is still unknown about the actors and mechanisms involved. We have in this work characterized the dnaXE145A clamp loader mutant. We find that the naturally occurring obstacles encountered by a replication fork are not tackled in a proper way by the mutant clamp loader and suggest a role for the clamp loader in the restart of stalled replication forks

  20. Diminished activation of motor working-memory networks in Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Claudia Rottschy

    Full Text Available Parkinson's disease (PD is characterized by typical extrapyramidal motor features and increasingly recognized non-motor symptoms such as working memory (WM deficits. Using functional magnetic resonance imaging (fMRI, we investigated differences in neuronal activation during a motor WM task in 23 non-demented PD patients and 23 age- and gender-matched healthy controls. Participants had to memorize and retype variably long visuo-spatial stimulus sequences after short or long delays (immediate or delayed serial recall. PD patients showed deficient WM performance compared to controls, which was accompanied by reduced encoding-related activation in WM-related regions. Mirroring slower motor initiation and execution, reduced activation in motor structures such as the basal ganglia and superior parietal cortex was detected for both immediate and delayed recall. Increased activation in limbic, parietal and cerebellar regions was found during delayed recall only. Increased load-related activation for delayed recall was found in the posterior midline and the cerebellum. Overall, our results demonstrate that impairment of WM in PD is primarily associated with a widespread reduction of task-relevant activation, whereas additional parietal, limbic and cerebellar regions become more activated relative to matched controls. While the reduced WM-related activity mirrors the deficient WM performance, the additional recruitment may point to either dysfunctional compensatory strategies or detrimental crosstalk from "default-mode" regions, contributing to the observed impairment.

  1. Rerults of work of the Raptor Ringing Center of the Russian Raptor Research and Conservation Network in 2014

    Directory of Open Access Journals (Sweden)

    Igor V. Karyakin

    2015-12-01

    Full Text Available In work of the Raptor Ringing Center of the Russian Raptor Research and Conservation Network in 2014 participated 39 ornithologists-researchers and birdwatchers who have ringed in total 889 individuals of 23 species of birds of prey (Falconiformers and owls. From colour marked birds the leaders are Upland Buzzard (Buteo hemilasius – 154 ind., Eastern Imperial Eagle (Aquila heliaca – 110 ind., Steppe Eagle (Aquila nipalensis – 95 ind., Long-Legged Buzzard (Buteo rufinus – 87 ind., White-Tailed Eagle (Haliaeetus albicilla – 78ind. For 2014 and the first 5 months of 2015 the information was received about the registration of 50 birds with rings from which 39 birds were identified . Among returns the leaders are Eastern Imperial Eagle (14 ind. and White-Tailed Eagle (9ind..

  2. Results of work of the Raptor Ringing Center of the Russian Raptor Research and Conservation Network in 2015

    Directory of Open Access Journals (Sweden)

    Rinur H. Bekmansurov

    2017-01-01

    Full Text Available In work of the Raptor Ringing Center of the Russian Raptor Research and Conservation Network in 2015 participated 35 ornithologists-researchers and birdwatchers who have ringed in total 752 individuals of 22 species of birds of prey and owls. From colour ringed birds the leaders are Steppe Eagle (Aquila nipalensis – 281 ind., Eastern Imperial Eagle (Aquila heliaca – 91 ind., Osprey (Pandion haliaetus – 72 ind., White-Tailed Eagle (Haliaeetus albicilla – 73 ind., and Long-Legged Buzzard (Buteo rufinus – 65 ind. For period from 1 June 2015 – 30 May 2016 the information was received about the registration of 46 birds with rings from which 38 birds were identified. Among recoveries the leaders are Osprey (10 ind., White-Tailed Eagle (10 ind. and Eastern Imperial Eagle (6 ind..

  3. Application of active electrode compensation to perform continuous voltage-clamp recordings with sharp microelectrodes

    Science.gov (United States)

    Gómez-González, J. F.; Destexhe, A.; Bal, T.

    2014-10-01

    Objective. Electrophysiological recordings of single neurons in brain tissues are very common in neuroscience. Glass microelectrodes filled with an electrolyte are used to impale the cell membrane in order to record the membrane potential or to inject current. Their high resistance induces a high voltage drop when passing current and it is essential to correct the voltage measurements. In particular, for voltage clamping, the traditional alternatives are two-electrode voltage-clamp technique or discontinuous single electrode voltage-clamp (dSEVC). Nevertheless, it is generally difficult to impale two electrodes in a same neuron and the switching frequency is limited to low frequencies in the case of dSEVC. We present a novel fully computer-implemented alternative to perform continuous voltage-clamp recordings with a single sharp-electrode. Approach. To reach such voltage-clamp recordings, we combine an active electrode compensation algorithm (AEC) with a digital controller (AECVC). Main results. We applied two types of control-systems: a linear controller (proportional plus integrative controller) and a model-based controller (optimal control). We compared the performance of the two methods to dSEVC using a dynamic model cell and experiments in brain slices. Significance. The AECVC method provides an entirely digital method to perform continuous recording and smooth switching between voltage-clamp, current clamp or dynamic-clamp configurations without introducing artifacts.

  4. A structural and mechanistic study of π-clamp-mediated cysteine perfluoroarylation.

    Science.gov (United States)

    Dai, Peng; Williams, Jonathan K; Zhang, Chi; Welborn, Matthew; Shepherd, James J; Zhu, Tianyu; Van Voorhis, Troy; Hong, Mei; Pentelute, Bradley L

    2017-08-11

    Natural enzymes use local environments to tune the reactivity of amino acid side chains. In searching for small peptides with similar properties, we discovered a four-residue π-clamp motif (Phe-Cys-Pro-Phe) for regio- and chemoselective arylation of cysteine in ribosomally produced proteins. Here we report mutational, computational, and structural findings directed toward elucidating the molecular factors that drive π-clamp-mediated arylation. We show the significance of a trans conformation prolyl amide bond for the π-clamp reactivity. The π-clamp cysteine arylation reaction enthalpy of activation (ΔH‡) is significantly lower than a non-π-clamp cysteine. Solid-state NMR chemical shifts indicate the prolyl amide bond in the π-clamp motif adopts a 1:1 ratio of the cis and trans conformation, while in the reaction product Pro3 was exclusively in trans. In two structural models of the perfluoroarylated product, distinct interactions at 4.7 Å between Phe1 side chain and perfluoroaryl electrophile moiety are observed. Further, solution 19F NMR and isothermal titration calorimetry measurements suggest interactions between hydrophobic side chains in a π-clamp mutant and the perfluoroaryl probe. These studies led us to design a π-clamp mutant with an 85-fold rate enhancement. These findings will guide us toward the discovery of small reactive peptides to facilitate abiotic chemistry in water.

  5. Application of active electrode compensation to perform continuous voltage-clamp recordings with sharp microelectrodes.

    Science.gov (United States)

    Gómez-González, J F; Destexhe, A; Bal, T

    2014-10-01

    Electrophysiological recordings of single neurons in brain tissues are very common in neuroscience. Glass microelectrodes filled with an electrolyte are used to impale the cell membrane in order to record the membrane potential or to inject current. Their high resistance induces a high voltage drop when passing current and it is essential to correct the voltage measurements. In particular, for voltage clamping, the traditional alternatives are two-electrode voltage-clamp technique or discontinuous single electrode voltage-clamp (dSEVC). Nevertheless, it is generally difficult to impale two electrodes in a same neuron and the switching frequency is limited to low frequencies in the case of dSEVC. We present a novel fully computer-implemented alternative to perform continuous voltage-clamp recordings with a single sharp-electrode. To reach such voltage-clamp recordings, we combine an active electrode compensation algorithm (AEC) with a digital controller (AECVC). We applied two types of control-systems: a linear controller (proportional plus integrative controller) and a model-based controller (optimal control). We compared the performance of the two methods to dSEVC using a dynamic model cell and experiments in brain slices. The AECVC method provides an entirely digital method to perform continuous recording and smooth switching between voltage-clamp, current clamp or dynamic-clamp configurations without introducing artifacts.

  6. Implementing dynamic clamp with synaptic and artificial conductances in mouse retinal ganglion cells.

    Science.gov (United States)

    Huang, Jin Y; Stiefel, Klaus M; Protti, Dario A

    2013-05-16

    Ganglion cells are the output neurons of the retina and their activity reflects the integration of multiple synaptic inputs arising from specific neural circuits. Patch clamp techniques, in voltage clamp and current clamp configurations, are commonly used to study the physiological properties of neurons and to characterize their synaptic inputs. Although the application of these techniques is highly informative, they pose various limitations. For example, it is difficult to quantify how the precise interactions of excitatory and inhibitory inputs determine response output. To address this issue, we used a modified current clamp technique, dynamic clamp, also called conductance clamp (1, 2, 3) and examined the impact of excitatory and inhibitory synaptic inputs on neuronal excitability. This technique requires the injection of current into the cell and is dependent on the real-time feedback of its membrane potential at that time. The injected current is calculated from predetermined excitatory and inhibitory synaptic conductances, their reversal potentials and the cell's instantaneous membrane potential. Details on the experimental procedures, patch clamping cells to achieve a whole-cell configuration and employment of the dynamic clamp technique are illustrated in this video article. Here, we show the responses of mouse retinal ganglion cells to various conductance waveforms obtained from physiological experiments in control conditions or in the presence of drugs. Furthermore, we show the use of artificial excitatory and inhibitory conductances generated using alpha functions to investigate the responses of the cells.

  7. The transducer domain is important for clamp operation in human DNA topoisomerase IIalpha

    DEFF Research Database (Denmark)

    Oestergaard, Vibe H; Bjergbaek, Lotte; Skouboe, Camilla

    2003-01-01

    the clamp to the enzyme core. Although structurally conserved, it is unclear whether the transducer domain is involved in clamp mechanism. We have purified and characterized a human topoisomerase II alpha enzyme with a two-amino acid insertion at position 408 in the transducer domain. The enzyme retains...

  8. Using atomic force microscopy to investigate patch-clamped nuclear membrane.

    Science.gov (United States)

    Danker, T; Mazzanti, M; Tonini, R; Rakowska, A; Oberleithner, H

    1997-11-01

    Nuclear patch clamp is an emerging research field that aims to disclose the electrical phenomena underlying macromolecular transport across the nuclear envelope (NE), its properties as an ion barrier and its function as an intracellular calcium store. The authors combined the patch clamp technique with atomic force microscopy (AFM) to investigate the structure-function relationship of NE. In principle, patch clamp currents, recorded from the NE can indicate the activity of the nuclear pore complexes (NPCs) and/or of ion channels in the two biomembranes that compose the NE. However, the role of the NPCs is still nuclear because the observed NE current in patch clamp experiments is lower than expected from the known density of the NPCs. Therefore, AFM was applied to link patch clamp currents to structure. The membrane patch was excised from the nuclear envelope and, after electrical evaluation, transferred from the patch pipette to a substrate. We could identify the native nuclear membrane patches with AFM at a lateral and a vertical resolution of 3 nm and 0.1 nm, respectively. It was shown that complete NE together with NPCs can be excised from the nucleus after their functional identification in patch clamp experiments. However, we also show that membranes of the endoplasmic reticulum can contaminate the tip of the patch pipette during nuclear patch clamp experiments. This possibility must be considered carefully in nuclear patch clamp experiments.

  9. Relating glucose clamp profiles to reduction of blood glucose after insulin administration.

    Science.gov (United States)

    Woodworth, James R; Howey, Daniel C; Bowsher, Ronald R; Brunelle, Rocco L

    2004-04-01

    A model was established allowing prediction of blood glucose response from glucose clamp results performed in healthy volunteers. Data from published studies performed in healthy volunteers were used to establish, test, and validate a model for the evaluation of glucose reductions from glucose clamp results. Studies included those that measured blood glucose and glucodynamic response over time after administration of 0.05 U/kg of regular human insulin (HR) and insulin lispro (LP) with and without the benefit of a glucose clamp procedure. An inhibitory effect E(max) model was used to describe the relationship; the model differed between the HR and LP responses by the intensity of the counterregulatory response as assessed by glucagon measurements. The relationships were used to predict blood glucose responses from a clamp study assessing NPH insulin and HR administrations. Glucose concentrations measured after administration of NPH insulin and HR without a clamp were compared to the model-predicted results to assess the accuracy of the model predictions. The E(max) model successfully correlated the glucose clamp results with the blood glucose depressions in the presence and absence of a counterregulatory response. However, predictions of glucose depression were only accurately modeled in the absence of a counterregulatory glucagon response. The correlations established with a minimal counterregulatory response underscore the value of glucose clamp procedures in defining the time-activity profiles of insulins when the clamp is established at fasting glucose concentrations.

  10. Combined action potential- and dynamic-clamp for accurate computational modelling of the cardiac IKr current.

    Science.gov (United States)

    Bartolucci, Chiara; Altomare, Claudia; Bennati, Marco; Furini, Simone; Zaza, Antonio; Severi, Stefano

    2015-02-01

    In the present work Action-Potential clamp (APC) and Dynamic clamp (DC) were used in combination in order to optimize the Luo-Rudy (LRd) mathematical formulation of the guinea-pig rapid delayed rectifier K(+) current (IKr), and to validate the optimized model. To this end, IKr model parameters were adjusted to fit the experimental E4031-sensitive current (IE4031) recorded under APC in guinea-pig myocytes. Currents generated by LRd model (ILRd) and the optimized one (IOpt) were then compared by testing their suitability to replace IE4031 under DC. Under APC, ILRd was significantly larger than IE4031 (mean current densities 0.51±0.01 vs 0.21±0.05pA/pF; p<0.001), mainly because of different rectification. IOpt mean density (0.17±0.01pA/pF) was similar to the IE4031 one (NS); moreover, IOpt accurately reproduced IE4031 distribution along the different AP phases. Models were then compared under DC by blocking native IKr (5μM E4031) and replacing it with ILRd or IOpt. Whereas injection of ILRd overshortened AP duration (APD90) (by 25% of its pre-block value), IOpt injection restored AP morphology and duration to overlap pre-block values. This study highlights the power of APC and DC for the identification of reliable formulations of ionic current models. An optimized model of IKr has been obtained which fully reversed E4031 effects on the AP. The model strongly diverged from the widely used Luo-Rudy formulation; this can be particularly relevant to the in silico analysis of AP prolongation caused by IKr blocking or alterations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Automatic tracking of cells for video microscopy in patch clamp experiments.

    Science.gov (United States)

    Peixoto, Helton M; Munguba, Hermany; Cruz, Rossana M S; Guerreiro, Ana M G; Leao, Richardson N

    2014-06-20

    Visualisation of neurons labeled with fluorescent proteins or compounds generally require exposure to intense light for a relatively long period of time, often leading to bleaching of the fluorescent probe and photodamage of the tissue. Here we created a technique to drastically shorten light exposure and improve the targeting of fluorescent labeled cells that is specially useful for patch-clamp recordings. We applied image tracking and mask overlay to reduce the time of fluorescence exposure and minimise mistakes when identifying neurons. Neurons are first identified according to visual criteria (e.g. fluorescence protein expression, shape, viability etc.) and a transmission microscopy image Differential Interference Contrast (DIC) or Dodt contrast containing the cell used as a reference for the tracking algorithm. A fluorescence image can also be acquired later to be used as a mask (that can be overlaid on the target during live transmission video). As patch-clamp experiments require translating the microscope stage, we used pattern matching to track reference neurons in order to move the fluorescence mask to match the new position of the objective in relation to the sample. For the image processing we used the Open Source Computer Vision (OpenCV) library, including the Speeded-Up Robust Features (SURF) for tracking cells. The dataset of images (n = 720) was analyzed under normal conditions of acquisition and with influence of noise (defocusing and brightness). We validated the method in dissociated neuronal cultures and fresh brain slices expressing Enhanced Yellow Fluorescent Protein (eYFP) or Tandem Dimer Tomato (tdTomato) proteins, which considerably decreased the exposure to fluorescence excitation, thereby minimising photodamage. We also show that the neuron tracking can be used in differential interference contrast or Dodt contrast microscopy. The techniques of digital image processing used in this work are an important addition to the set of microscopy

  12. Levels of processing in working memory: differential involvement of frontotemporal networks.

    Science.gov (United States)

    Rose, Nathan S; Craik, Fergus I M; Buchsbaum, Bradley R

    2015-03-01

    How does the brain maintain to-be-remembered information in working memory (WM), particularly when the focus of attention is drawn to processing other information? Cognitive models of WM propose that when items are displaced from focal attention recall involves retrieval from long-term memory (LTM). In this fMRI study, we tried to clarify the role of LTM in performance on a WM task and the type of representation that is used to maintain an item in WM during rehearsal-filled versus distractor-filled delays. Participants made a deep or shallow levels-of-processing (LOP) decision about a single word at encoding and tried to recall the word after a delay filled with either rehearsal of the word or a distracting math task. Recalling one word after 10 sec of distraction demonstrated behavioral and neural indices of retrieval from LTM (i.e., LOP effects and medial-temporal lobe activity). In contrast, recall after rehearsal activated cortical areas that reflected reporting the word from focal attention. In addition, areas that showed an LOP effect at encoding (e.g., left ventrolateral VLPFC and the anterior temporal lobes [ATLs]) were reactivated at recall, especially when recall followed distraction. Moreover, activity in left VLPFC during encoding, left ATL during the delay, and left hippocampus during retrieval predicted recall success after distraction. Whereas shallow LOP and rehearsal-related areas supported active maintenance of one item in focal attention, the behavioral processes and neural substrates that support LTM supported recall of one item after it was displaced from focal attention.

  13. Applying the Principle of Variables to Solve the Problems of Forced Vibration of the plate with three clamped and the other free with concentrated load

    Directory of Open Access Journals (Sweden)

    Chen Ying Jie

    2016-01-01

    Full Text Available In this paper, with the principle of least action with variables to solve the problems of forced vibration of the Rectangular plate with three clamped and the other free with concentrated load, and the stable solution can be worked out. We can compare the results with the literate; it also can be proved to be true. So the results by calculating not only it have important academic value, but also it can be directly referred in the actual work.

  14. Modeling of SVM Diode Clamping Three-Level Inverter Connected to Grid

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong

    2011-01-01

    PLECS is used to model the diode clamping three-level inverter connected to grid and good results are obtained. First the output voltage SVM is described for diode clamping three-level inverter with loads connected to Y. Then the output voltage SVM of diode clamping three-level inverter is simply...... analyzed with loads connected to △. But it will be further researched in the future. Third, PLECS is briefly introduced. Fourth, the modeling of diode clamping three-level inverter is briefly presented with PLECS. Finally, a series of simulations are carried out. The simulation results tell us PLECS...... is very powerful tool to real power circuits and it is very easy to simulate them. They have also verified that SVM control strategy is feasible to control the diode clamping three-level inverter....

  15. A reduction clamp for an aiming component in associated acetabular fractures

    Directory of Open Access Journals (Sweden)

    Zhang-Fu Wang

    2015-01-01

    Full Text Available Background: The treatment of acetabular fractures is complex and requires specialized equipment. However, all currently available instruments have some disadvantages. A new reduction clamp that can firmly enable reduction and not hinder subsequent fixation procedures for some special fracture types is needed. Materials and Methods: In this study, we introduce a new acetabular clamp and its preliminary clinical application in three T-shaped acetabular fractures. Results: This new clamp can successfully pull the posterior column back to the anterior column and firmly maintain the reduction. This clamp′s aiming plate can facilitate the insertion of long lag screws. The clamp is also easy to assemble and use. Conclusion: This reduction clamp is a useful instrument that can facilitate open reduction and internal fixation of acetabular fractures.

  16. Tensions of network security and collaborative work practice: understanding a single sign-on deployment in a regional hospital.

    Science.gov (United States)

    Heckle, Rosa R; Lutters, Wayne G

    2011-08-01

    Healthcare providers and their IT staff, working in an effort to balance appropriate accessibility with stricter security mandates, are considering the use of a single network sign-on approach for authentication and password management. Single sign-on (SSO) promises to improve usability of authentication for multiple-system users, increase compliance, and help curb system maintenance costs. However, complexities are introduced when SSO is placed within a collaborative environment. These complexities include unanticipated workflow implications that introduce greater security vulnerability for the individual user. OBJECTIVES AND METHODOLOGY: In this work, we examine the challenges of implementing a single sign-on authentication technology in a hospital environment. The aim of the study was to document the factors that affected SSO adoption within the context of use. The ultimate goal is to better inform the design of usable authentication systems within collaborative healthcare work sites. The primary data collection techniques used are ethnographically informed - observation, contextual interviews, and document review. The study included a cross-section of individuals from various departments and varying rolls. These participants were a mix of both clinical and administrative staff, as well as the Information Technology group. The field work revealed fundamental mis-matches between the technology and routine work practices that will significantly impact its effective adoption. While single sign-on was effective in the administrative offices, SSO was not a good fit for collaborative areas. The collaborative needs of the clinical staff unearthed tensions in its implementation. An analysis of the findings revealed that the workflow, activities, and physical environment of the clinical areas create increased security vulnerabilities for the individual user. The clinical users were cognizant of these vulnerabilities and this created resistance to the implementation due

  17. dfnWorks: A HPC Workflow for Discrete Fracture Network Modeling with Subsurface Flow and Transport Applications

    Science.gov (United States)

    Gable, C. W.; Hyman, J.; Karra, S.; Makedonska, N.; Painter, S. L.; Viswanathan, H. S.

    2015-12-01

    dfnWorks generates discrete fracture networks (DFN) of planar polygons, creates a high quality conforming Delaunay triangulation of the intersecting DFN polygons, assigns properties (aperture, permeability) using geostatistics, sets boundary and initial conditions, solves pressure/flow in single or multi-phase fluids (water, air, CO2) using the parallel PFLOTRAN or serial FEHM, and solves for transport using Lagrangian particle tracking. We outline the dfnWorks workflow and present applications from a range of fractured rock systems. dfnWorks (http://www.lanl.gov/expertise/teams/view/dfnworks) is composed of three main components, all of which are freely available. dfnGen generates a distribution of fracture polygons from site characterization data (statistics or deterministic fractures) and utilizes the FRAM (Feature Rejection Algorithm for Meshing) to guarantee the mesh generation package LaGriT (lagrit.lanl.gov) will generate a high quality conforming Delaunay triangular mesh. dfnWorks links the mesh to either PFLOTRAN (pflotran.org) or FEHM (fehm.lanl.gov) for solving flow and transport. The various physics options available in FEHM and PFLOTRAN such as single and multi-phase flow and reactive transport are all available with appropriate initial and boundary conditions and material property models. dfnTrans utilizes explicit Lagrangian particle tracking on the DFN using a velocity field reconstructed from the steady state pressure/flow field solution obtained in PFLOTRAN or FEHM. Applications are demonstrated for nuclear waste repository in fractured granite, CO2 sequestration and extraction of unconventional hydrocarbon resources.

  18. Escherichia coli processivity clamp β from DNA polymerase III is dynamic in solution†

    Science.gov (United States)

    Fang, Jing; Engen, John R.; Beuning, Penny J.

    2011-01-01

    Escherichia coli DNA polymerase III is a highly processive replicase due to the presence of the β clamp protein that tethers DNA polymerases to DNA. The β clamp is a head-to-tail ring-shaped homodimer, in which each protomer contains three structurally similar domains. Although multiple studies have probed the functions of the β clamp, a detailed understanding of the conformational dynamics of the β clamp in solution is lacking. Here we used hydrogen exchange mass spectrometry to characterize the conformation and dynamics of the intact dimer β clamp and a variant form (I272A/L273A) with diminished ability to dimerize in solution. Our data indicate that the β clamp is not a static closed ring but rather is dynamic in solution. The three domains showed different dynamics though they share a highly similar tertiary structure. Domain I, which controls the opening of the clamp by dissociating from Domain III, contained several highly flexible peptides that underwent partial cooperative unfolding (EX1 kinetics) with a half-life ~4 h. The comparison between the β monomer variant and the wild-type β clamp showed that the β monomer was more dynamic. In the monomer, partial unfolding was much faster and additional regions of Domain III also underwent partial unfolding with a half-life ~1 h. Our results suggest that the δ subunit of the clamp loader may function as a “ring holder” to stabilize the transient opening of the β clamp, rather than as a “ring opener”. PMID:21657794

  19. Design and analysis of different trigger techniques for ESD clamp circuit in 0.5-µm 5 V/18 V CDMOS process

    Science.gov (United States)

    Zhang, Wenjie; Yang, Liu; Wang, Yang; Jin, Xiangliang

    2017-09-01

    In this work, gate-driven, substrate-triggered and gate-substrate-triggered techniques for both 5 V NMOS-based and 18 V NLDMOS-based power clamps under electrostatic discharge (ESD) stress were investigated in details. Schematics of the three trigger designs were depicted and their physical mechanisms were studied at first. To verify and make comparisons of their performance, they were fabricated in a standard 0.5-μm 5 V/18 V CDMOS process and characterized by transmission line pulse (TLP) test system, respectively. Experimental results show that 5 V NMOS-based power clamp with substrate-triggered technique has the lowest trigger voltage (∼8.37 V) and the highest failure current (∼3.58 A), and 18 V gate-substrate-triggered design based on NLDMOS has low trigger voltage (∼34.02 V) and greatest robustness (It2 = 3.32 A). Therefore, as for low-voltage NMOS-based ESD power clamps, substrate-triggered design obtains the most superior ESD protection performance; but for high-voltage power clamps, gate-substrate-triggered technique can make NLDMOS actualize uniform current conduction and better ESD robustness.

  20. Social Network Analysis: Applied Tool to Enhance Effective Collaboration between Child Protection Organisations by Revealing and Strengthening Work Relationships

    National Research Council Canada - National Science Library

    Beáta Dávid

    2013-01-01

    .... The qualitative approach was complemented by social network analysis. Revealing the mechanism based on the actors' perception on how the child protection network operates, we identifi ed and named the strengths and weaknesses of its structure...

  1. Contributions of space-clamp errors to apparent time-dependent loss of Mg2+ block induced by NMDA.

    Science.gov (United States)

    Sun, Min-Yu; Chisari, Mariangela; Eisenman, Lawrence N; Zorumski, Charles F; Mennerick, Steven J

    2017-07-01

    N-methyl-d-aspartate receptors (NMDARs) govern synaptic plasticity, development, and neuronal response to insult. Prolonged activation of NMDARs such as during an insult may activate secondary currents or modulate Mg2+ sensitivity, but the conditions under which these occur are not fully defined. We reexamined the effect of prolonged NMDAR activation in juvenile mouse hippocampal slices. NMDA (10 μM) elicited current with the expected negative-slope conductance in the presence of 1.2 mM Mg2+ However, several minutes of continued NMDA exposure elicited additional inward current at -70 mV. A higher concentration of NMDA (100 µM) elicited the current more rapidly. The additional current was not dependent on Ca2+, network activity, or metabotropic NMDAR function and did not persist on agonist removal. Voltage ramps revealed no alteration of either reversal potential or NMDA-elicited conductance between -30 mV and +50 mV. The result was a more linear NMDA current-voltage relationship. The current linearization was also induced in interneurons and in mature dentate granule neurons but not immature dentate granule cells, dissociated cultured hippocampal neurons, or nucleated patches excised from CA1 pyramidal neurons. Comparative simulations of NMDA application to a CA1 pyramidal neuron and to a cultured neuron revealed that linearization can be explained by space-clamp errors arising from gradual recruitment of distal dendritic NMDARs. We conclude that persistent secondary currents do not strongly contribute to NMDAR responses in juvenile mouse hippocampus and careful discernment is needed to exclude contributions of clamp artifacts to apparent secondary currents.NEW & NOTEWORTHY We report that upon sustained activation of NMDARs in juvenile mouse hippocampal neurons there is apparent loss of Mg2+ block at negative membrane potentials. However, the phenomenon is explained by loss of dendritic voltage clamp, leading to a linear current-voltage relationship. Our results

  2. Who are the objects of positive and negative gossip at work? A social network perspective on workplace gossip

    NARCIS (Netherlands)

    Ellwardt, Lea; Labianca, Giuseppe (Joe); Wittek, Rafael

    Gossip is informal talking about colleagues. Taking a social network perspective, we argue that group boundaries and social status in the informal workplace network determine who the objects of positive and negative gossip are. Gossip networks were collected among 36 employees in a public child care

  3. Brain Networks for Working Memory and Factors of Intelligence Assessed in Males and Females with fMRI and DTI

    Science.gov (United States)

    Tang, C. Y.; Eaves, E. L.; Ng, J. C.; Carpenter, D. M.; Mai, X.; Schroeder, D. H.; Condon, C. A.; Colom, R.; Haier, R. J.

    2010-01-01

    Neuro-imaging studies of intelligence implicate the importance of a parietal-frontal network. One unresolved issue is whether this network underlies a general factor of intelligence ("g") or other specific cognitive factors. A second unresolved issue is whether males and females use different parts of this network. Here we obtained intelligence…

  4. Generalization of the dynamic clamp concept in neurophysiology and behavior.

    Directory of Open Access Journals (Sweden)

    Pablo Chamorro

    Full Text Available The idea of closed-loop interaction in in vitro and in vivo electrophysiology has been successfully implemented in the dynamic clamp concept strongly impacting the research of membrane and synaptic properties of neurons. In this paper we show that this concept can be easily generalized to build other kinds of closed-loop protocols beyond (or in addition to electrical stimulation and recording in neurophysiology and behavioral studies for neuroethology. In particular, we illustrate three different examples of goal-driven real-time closed-loop interactions with drug microinjectors, mechanical devices and video event driven stimulation. Modern activity-dependent stimulation protocols can be used to reveal dynamics (otherwise hidden under traditional stimulation techniques, achieve control of natural and pathological states, induce learning, bridge between disparate levels of analysis and for a further automation of experiments. We argue that closed-loop interaction calls for novel real time analysis, prediction and control tools and a new perspective for designing stimulus-response experiments, which can have a large impact in neuroscience research.

  5. Non-Hookean statistical mechanics of clamped graphene ribbons

    Science.gov (United States)

    Bowick, Mark J.; Košmrlj, Andrej; Nelson, David R.; Sknepnek, Rastko

    2017-03-01

    Thermally fluctuating sheets and ribbons provide an intriguing forum in which to investigate strong violations of Hooke's Law: Large distance elastic parameters are in fact not constant but instead depend on the macroscopic dimensions. Inspired by recent experiments on free-standing graphene cantilevers, we combine the statistical mechanics of thin elastic plates and large-scale numerical simulations to investigate the thermal renormalization of the bending rigidity of graphene ribbons clamped at one end. For ribbons of dimensions W ×L (with L ≥W ), the macroscopic bending rigidity κR determined from cantilever deformations is independent of the width when W expected. When W >ℓth , however, this thermally renormalized bending rigidity begins to systematically increase, in agreement with the scaling theory, although in our simulations we were not quite able to reach the system sizes necessary to determine the fully developed power law dependence on W . When the ribbon length L >ℓp , where ℓp is the W -dependent thermally renormalized ribbon persistence length, we observe a scaling collapse and the beginnings of large scale random walk behavior.

  6. Indentation metrology of clamped, ultra-thin elastic sheets.

    Science.gov (United States)

    Vella, Dominic; Davidovitch, Benny

    2017-03-15

    We study the indentation of ultrathin elastic sheets clamped to the edge of a circular hole. This classical setup has received considerable attention lately, being used by various experimental groups as a probe to measure the surface properties and stretching modulus of thin solid films. Despite the apparent simplicity of this method, the geometric nonlinearity inherent in the mechanical response of thin solid objects renders the analysis of the resulting data a nontrivial task. Importantly, the essence of this difficulty is in the geometric coupling between in-plane stress and out-of-plane deformations, and hence is present in the behaviour of Hookean solids even when the slope of the deformed membrane remains small. Here we take a systematic approach to address this problem, using the membrane limit of the Föppl-von-Kármán equations. This approach highlights some of the dangers in the use of approximate formulae in the metrology of solid films, which can introduce large errors; we suggest how such errors may be avoided in performing experiments and analyzing the resulting data.

  7. Supraceliac, but not infrarenal, aortic cross-clamping upregulates neutrophil integrin CD11b.

    Science.gov (United States)

    Hill, G E; Mihalakakos, P J; Spurzem, J R; Baxter, T B

    1995-10-01

    To evaluate the effects of supraceliac and infrarenal aortic cross-clamping on the expression of neutrophil integrin in CD11b (a marker of systemic cytokine release). Two groups, determined by anatomic placement of aortic cross-clamp. Laboratory personnel were blinded as to group assignment. University teaching and community hospitals. Laboratory facilities used were university and Veteran's Affairs medical centers. Patients scheduled for aortic surgery. Blood sampling was performed at baseline, after 30 minutes of aortic cross-clamp duration, 30 and 90 minutes after reperfusion (for tumor necrosis factor-alpha plasma levels in infrarenal cross-clamp group), and at baseline and 90 minutes reperfusion (for neutrophil CD11b expression quantification) in both groups. Tumor necrosis factor-alpha measured by ELISA technique did not change at any time period in the infrarenal clamping group. Neutrophil CD11b expression, measured by double antibody staining and FACScan analysis, did not change significantly at 90 minutes of reperfusion in the infrarenal group, but increased significantly (p entrapment and subsequent neutrophil-mediated reperfusion injury. These results suggest that upregulation of neutrophil integrin CD11b after supraceliac aortic clamping may in part be responsible for the higher incidence of acute lung injury after thoracic aortic aneurysm repair requiring supraceliac clamping when compared with infrarenal aneurysm surgery.

  8. Laparoscopic Partial Nephrectomy with a Remotely Activated Bulldog Clamp in a Pig Model.

    Science.gov (United States)

    Chen, Wei; Guo, Jian-Ming; Hou, Jun; Wang, Guo-Min

    2017-01-01

    Saving warm ischemia time (WIT) in laparoscopic partial nephrectomy (LPN) is important. We have designed a new device, a remotely activated bulldog clamp, to facilitate LPN. In present study, the effectiveness, convenience, and safety of the new design device were compared with that of standard bulldog vascular clamp in a pig model. Fifteen cases of LPN were bilaterally operated on upper or lower pole of kidneys in five pigs. As the test group, eight cases involved the remotely activated bulldog clamp, whereas the remaining seven cases, as the control group, involved the common standard vascular bulldog clamp. The mean operative time, blood lost, and mean WIT were compared between the two groups. The mean operative time and blood lost were not significantly different between the groups (p clamping was used in the two groups. With on-demand clamping, the mean WIT in the test group was 19.0 ± 3.42 minutes, which was significantly less compared with the control group (31.54 ± 5.23 minutes, p clamping and unclamping much easier. It is effective and safe in LPN.

  9. Dynamic assembly of Hda and the sliding clamp in the regulation of replication licensing.

    Science.gov (United States)

    Kim, Jin S; Nanfara, Michael T; Chodavarapu, Sundari; Jin, Kyeong S; Babu, Vignesh M P; Ghazy, Mohamed A; Chung, Scisung; Kaguni, Jon M; Sutton, Mark D; Cho, Yunje

    2017-04-20

    Regulatory inactivation of DnaA (RIDA) is one of the major regulatory mechanisms of prokaryotic replication licensing. In RIDA, the Hda-sliding clamp complex loaded onto DNA directly interacts with adenosine triphosphate (ATP)-bound DnaA and stimulates the hydrolysis of ATP to inactivate DnaA. A prediction is that the activity of Hda is tightly controlled to ensure that replication initiation occurs only once per cell cycle. Here, we determined the crystal structure of the Hda-β clamp complex. This complex contains two pairs of Hda dimers sandwiched between two β clamp rings to form an octamer that is stabilized by three discrete interfaces. Two separate surfaces of Hda make contact with the β clamp, which is essential for Hda function in RIDA. The third interface between Hda monomers occludes the active site arginine finger, blocking its access to DnaA. Taken together, our structural and mutational analyses of the Hda-β clamp complex indicate that the interaction of the β clamp with Hda controls the ability of Hda to interact with DnaA. In the octameric Hda-β clamp complex, the inability of Hda to interact with DnaA is a novel mechanism that may regulate Hda function. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. Blood gas values in clamped and unclamped umbilical cord at birth.

    Science.gov (United States)

    Di Tommaso, Mariarosaria; Seravalli, Viola; Martini, Irene; La Torre, Pasquale; Dani, Carlo

    2014-09-01

    To determine the reliability of the cord blood gas analysis on the unclamped cord compared to the standard technique of sampling on double clamped cord. Prospective observational study conducted on 46 singleton neonates vaginally delivered at term. Matched pairs of umbilical artery and vein blood samples were collected from unclamped cord within 90s after birth and from the same cord after clamping, with the clamping occurring immediately after the first blood collection. A blood gas analysis was performed on each collected sample. Arterial and venous blood samples were analyzed for pH, PO2, pCO2, SaO2, hemoglobin concentration (ctHb) and base excess (BE). The values were compared between the two groups (clamped vs unclamped) using a Wilcoxon test. No significant difference was found in pH, PO2, pCO2, SaO2 and ctHb values on arterial blood between unclamped and clamped cord. The only significant difference was related to BE (pblood, the values of pH, PO2, pCO2 were comparable between unclamped and clamped cord, while the values of SaO2, ctHb and BE were significantly different (pblood gas parameters and in the main venous blood gas parameters between unclamped and clamped cord. Sampling of cord blood for gas analysis may be performed on the unclamped cord right after birth without reducing the accuracy of the analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Dopamine modulation of GABAergic function enables network stability and input selectivity for sustaining working memory in a computational model of the prefrontal cortex.

    Science.gov (United States)

    Lew, Sergio E; Tseng, Kuei Y

    2014-12-01

    Dopamine modulation of GABAergic transmission in the prefrontal cortex (PFC) is thought to be critical for sustaining cognitive processes such as working memory and decision-making. Here, we developed a neurocomputational model of the PFC that includes physiological features of the facilitatory action of dopamine on fast-spiking interneurons to assess how a GABAergic dysregulation impacts on the prefrontal network stability and working memory. We found that a particular non-linear relationship between dopamine transmission and GABA function is required to enable input selectivity in the PFC for the formation and retention of working memory. Either degradation of the dopamine signal or the GABAergic function is sufficient to elicit hyperexcitability in pyramidal neurons and working memory impairments. The simulations also revealed an inverted U-shape relationship between working memory and dopamine, a function that is maintained even at high levels of GABA degradation. In fact, the working memory deficits resulting from reduced GABAergic transmission can be rescued by increasing dopamine tone and vice versa. We also examined the role of this dopamine-GABA interaction for the termination of working memory and found that the extent of GABAergic excitation needed to reset the PFC network begins to occur when the activity of fast-spiking interneurons surpasses 40 Hz. Together, these results indicate that the capability of the PFC to sustain working memory and network stability depends on a robust interplay of compensatory mechanisms between dopamine tone and the activity of local GABAergic interneurons.

  12. Analysis of the role of PCNA-DNA contacts during clamp loading

    Directory of Open Access Journals (Sweden)

    Goedken Eric R

    2010-01-01

    Full Text Available Abstract Background Sliding clamps, such as Proliferating Cell Nuclear Antigen (PCNA in eukaryotes, are ring-shaped protein complexes that encircle DNA and enable highly processive DNA replication by serving as docking sites for DNA polymerases. In an ATP-dependent reaction, clamp loader complexes, such as the Replication Factor-C (RFC complex in eukaryotes, open the clamp and load it around primer-template DNA. Results We built a model of RFC bound to PCNA and DNA based on existing crystal structures of clamp loaders. This model suggests that DNA would enter the clamp at an angle during clamp loading, thereby interacting with positively charged residues in the center of PCNA. We show that simultaneous mutation of Lys 20, Lys 77, Arg 80, and Arg 149, which interact with DNA in the RFC-PCNA-DNA model, compromises the ability of yeast PCNA to stimulate the DNA-dependent ATPase activity of RFC when the DNA is long enough to extend through the clamp. Fluorescence anisotropy binding experiments show that the inability of the mutant clamp proteins to stimulate RFC ATPase activity is likely caused by reduction in the affinity of the RFC-PCNA complex for DNA. We obtained several crystal forms of yeast PCNA-DNA complexes, measuring X-ray diffraction data to 3.0 Å resolution for one such complex. The resulting electron density maps show that DNA is bound in a tilted orientation relative to PCNA, but makes different contacts than those implicated in clamp loading. Because of apparent partial disorder in the DNA, we restricted refinement of the DNA to a rigid body model. This result contrasts with previous analysis of a bacterial clamp bound to DNA, where the DNA was well resolved. Conclusion Mutational analysis of PCNA suggests that positively charged residues in the center of the clamp create a binding surface that makes contact with DNA. Disruption of this positive surface, which had not previously been implicated in clamp loading function, reduces RFC

  13. Automated Patch Clamp Meets High-Throughput Screening: 384 Cells Recorded in Parallel on a Planar Patch Clamp Module.

    Science.gov (United States)

    Obergrussberger, Alison; Brüggemann, Andrea; Goetze, Tom A; Rapedius, Markus; Haarmann, Claudia; Rinke, Ilka; Becker, Nadine; Oka, Takayuki; Ohtsuki, Atsushi; Stengel, Timo; Vogel, Marius; Steindl, Juergen; Mueller, Max; Stiehler, Johannes; George, Michael; Fertig, Niels

    2016-12-01

    We have developed an automated patch clamp module for high-throughput ion channel screening, recording from 384 cells simultaneously. The module is incorporated into a laboratory pipetting robot and uses a 384-channel pipettor head for application of cells and compounds. The module contains 384 amplifier channels for fully parallel recordings using a digital amplifier. Success rates for completed experiments (1- to 4-point concentration-response curves for cells satisfying defined quality control parameters) of greater than 85% have been routinely achieved with, for example, HEK, CHO, and RBL cell lines expressing hNaV1.7, hERG, Kir2.1, GABA, or glutamate receptors. Pharmacology experiments are recorded and analyzed using specialized software, and the pharmacology of hNaV1.7 and hERG is described. Fast external solution exchange rates of robot to minimize exposure of the ligand on the receptor. This ensures that ligand-gated ion channels, for example, GABA and glutamate described in this report, can be reproducibly recorded. Stem cell-derived cardiomyocytes have also been used with success rates of 52% for cells that have a seal resistance of >200 MΩ, and recordings of voltage-gated Na+ and Ca2+ are shown. © 2015 Society for Laboratory Automation and Screening.

  14. An analysis of Social Work Oncology Network Listserv Postings on the Commission of Cancer's distress screening guidelines.

    Science.gov (United States)

    Burg, Mary Ann; Adorno, Gail; Hidalgo, Jorge

    2012-01-01

    This is a qualitative study of listserv postings by members of the Social Work Oncology Network (SWON) in response to the Commission on Cancer's 2011 guidelines for distress screening of cancer patients. Archived listserv postings for the period of December 2010 to November 2011 were deidentified and a sample was derived by a list of keywords for the analysis. Aims of the study included describing the general categories and themes of the postings devoted to the new distress screening standard and examining the process of facilitation of mutual support and information exchange by oncology social workers in response to the new screening standards. During the 12-month timeframe there were 242 unique listserv postings sampled for the analysis. Oncology social worker (OSW) discussion of the distress screening guidelines remained a constant topic over the 12 months, and major themes that emerged from the data included processes of implementation of distress screening in cancer centers, screening policies and protocols, screening tool choice, and oncology social worker professional identity. The SWON listserv members used the listserv as a mechanism to post their requests for information on screening, to share their experiences in the beginning stages of implementing the guidelines, and to build support for legitimizing oncology social workers as the lead profession in the implementation of the guidelines in member cancer centers.

  15. A pilot program to evaluate deceased donor disease transmission risk: the New York Organ Donor Network Infectious Disease Working Group.

    Science.gov (United States)

    Pellett Madan, Rebecca; Delli Carpini, Kristin; Huprikar, Shirish; Lerner, Harvey; Patel, Gopi; Ratner, Lloyd E; Goldstein, Michael J; Herold, Betsy C

    2014-10-27

    Recent cases of donor-derived infections raise the question of how best to screen donors without excessive restriction of the donor pool. The New York Organ Donor Network (NYODN) established an Infectious Diseases Working Group (IDWG) in 2008, which established an on-call schedule of voluntary transplant infectious disease physicians to provide remote evaluations for donors at increased risk for disease transmission. Data were reviewed from 40 available IDWG evaluations from 2008 to 2011. Eighteen cases (45%) were considered to be at unacceptable risk for infection transmission. Sixteen of these cases were excluded from donation secondary to IDWG recommendation; there was limited recipient center interest in the remaining two cases. Approximately 22 (55%) cases were categorized by the IDWG as acceptable, with 14 proceeding to recovery of 49 organs. IDWG physician recommendations were conveyed to recipient centers, and screening guidelines for donors were revised based on the IDWG experiences. Establishment of a donation service area disease transmission evaluation service is a valuable program for donor screening and may promote dissemination of more detailed donor information to recipient centers.

  16. Effects of current clamp on chick retinal pigment epithelium.

    Science.gov (United States)

    Fujii, S; Hughes, B A; Steinberg, R H

    1991-06-01

    The basal membrane of the retinal pigment epithelium (RPE) is the origin of two components of the electroretinogram, the fast oscillation and the light peak. Both of these responses originate from changes in basal membrane potential (Vba), and both are associated with changes in basal membrane resistance (Rba). In addition, many experimental manipulations that alter Vba also produce apparent changes in Rba. These findings raise the possibility that the basal membrane contains a voltage-sensitive conductance that operates in the physiologic range and is involved causally in light-evoked and other responses. We report the results of current clamp experiments on the isolated retina-RPE-choroid of chick that were designed to test for the presence of such a voltage-sensitive conductance in the basal membrane. Depolarizing Vba by 15 mV with retina-to-choroid current had essentially no effect on either the ratio of membrane resistances (Rap/Rba) or the transtissue resistance (RTotal), indicating no alteration in Rba. In contrast, hyperpolarizing Vba by 15 mV with choroid-to-retina current caused a gradual decrease in RTotal and increase in Rap/Rba. Analysis of accompanying changes in membrane voltages and changes in intracellular c-wave amplitude suggested that the most likely cause of the decrease in RTotal is a decrease in paracellular resistance. Voltage-sensitive conductances of the basal membrane appear to play little or no role in the resistance changes that accompany changes in Vba in the physiologic range. The conductance changes underlying the fast oscillation and light peak probably result from either the modulation of channels by second messengers or changes in intracellular ion concentration.

  17. Design and application of air-conditioning suit based on eddy current cooling principle for distribution network working with power uninterrupted

    Science.gov (United States)

    Xu, Li; Liu, Lanlan; Niu, Jie; Tang, Li; Li, Jinliang; Zhou, Zhanfan; Long, Chenhai; Yang, Qi; Yi, Ziqi; Guo, Hao; Long, Yang; Fu, Yanyi

    2017-05-01

    As social requirement of power supply reliability keeps rising, distribution network working with power uninterrupted has been widely carried out, while the high - temperature operating environment in summer can easily lead to physical discomfort for the operators, and then lead to safety incidents. Aiming at above problem, air-conditioning suit for distribution network working with power uninterrupted has been putted forward in this paper, and the structure composition and cooling principle of which has been explained, and it has been ultimately put to on-site application. The results showed that, cooling effect of air-conditioning suits was remarkable, and improved the working environment for the operators effectively, which is of great significance to improve Chinese level of working with power uninterrupted, reduce the probability of accidents and enhance the reliability of power supply.

  18. Using model-based functional MRI to locate working memory updates and declarative memory retrievals in the fronto-parietal network.

    Science.gov (United States)

    Borst, Jelmer P; Anderson, John R

    2013-01-29

    In this study, we used model-based functional MRI (fMRI) to locate two functions of the fronto-parietal network: declarative memory retrievals and updating of working memory. Because regions in the fronto-parietal network are by definition coherently active, locating functions within this network is difficult. To overcome this problem, we applied model-based fMRI, an analysis method that uses predictions of a computational model to inform the analysis. We applied model-based fMRI to five previously published datasets with associated computational cognitive models, and subsequently integrated the results in a meta-analysis. The meta-analysis showed that declarative memory retrievals correlated with activity in the inferior frontal gyrus and the anterior cingulate, whereas updating of working memory corresponded to activation in the inferior parietal lobule, as well as to activation around the inferior frontal gyrus and the anterior cingulate.

  19. Working at the margins of global production networks:local labour control regimes and rural-based labourers in South India

    OpenAIRE

    Pattenden, Jonathan

    2016-01-01

    This article analyses why informal labourers working ‘at the margins’ of global production networks lack ‘structural’ and ‘associational’ power. It does so in order to better understand potential changes in their material and political conditions, and as part of broader calls to put labour at the centre of development studies. The article focuses on rural-based labourers in south India who work relatively invisibly as agricultural labourers, informal factory workers, and on the construction s...

  20. Implementation of a fast 16-Bit dynamic clamp using LabVIEW-RT.

    Science.gov (United States)

    Kullmann, Paul H M; Wheeler, Diek W; Beacom, Joshua; Horn, John P

    2004-01-01

    The dynamic-clamp method provides a powerful electrophysiological tool for creating virtual ionic conductances in living cells and studying their influence on membrane potential. Here we describe G-clamp, a new way to implement a dynamic clamp using the real-time version of the Lab-VIEW programming environment together with a Windows host, an embedded microprocessor that runs a real-time operating system and a multifunction data-acquisition board. The software includes descriptions of a fast voltage-dependent sodium conductance, delayed rectifier, M-type and A-type potassium conductances, and a leak conductance. The system can also read synaptic conductance waveforms from preassembled data files. These virtual conductances can be reliably implemented at speeds LabVIEW should make it relatively easy for others to adapt G-clamp for new experimental applications.

  1. Model Clamp: A Computer Tool to Probe Action Potential Transfer Between Cardiac Cells

    National Research Council Canada - National Science Library

    Wilders, Ronald

    2001-01-01

    In the early nineties, Joyner and coworkers introduced the "coupling clamp" technique in which an isolated cardiac cell can be electrically coupled to either another isolated cardiac cell or to an analog model cell (RC circuit...

  2. Stepwise unfolding of titin under force-clamp atomic force microscopy.

    Science.gov (United States)

    Oberhauser, A F; Hansma, P K; Carrion-Vazquez, M; Fernandez, J M

    2001-01-16

    Here we demonstrate the implementation of a single-molecule force clamp adapted for use with an atomic force microscope. We show that under force-clamp conditions, an engineered titin protein elongates in steps because of the unfolding of its modules and that the waiting times to unfold are exponentially distributed. Force-clamp measurements directly measure the force dependence of the unfolding probability and readily captures the different mechanical stability of the I27 and I28 modules of human cardiac titin. Force-clamp spectroscopy promises to be a direct way to probe the mechanical stability of elastic proteins such as those found in muscle, the extracellular matrix, and cell adhesion.

  3. IS WORK-FAMILY CONFLICT A MULTILEVEL STRESSOR LINKING JOB CONDITIONS TO MENTAL HEALTH? EVIDENCE FROM THE WORK, FAMILY AND HEALTH NETWORK.

    Science.gov (United States)

    Moen, Phyllis; Kaduk, Anne; Kossek, Ellen Ernst; Hammer, Leslie; Buxton, Orfeu M; O'Donnell, Emily; Almeida, David; Fox, Kimberly; Tranby, Eric; Oakes, J Michael; Casper, Lynne

    Most research on the work conditions and family responsibilities associated with work-family conflict and other measures of mental health uses the individual employee as the unit of analysis. We argue that work conditions are both individual psychosocial assessments and objective characteristics of the proximal work environment, necessitating multilevel analyses of both individual- and team-level work conditions on mental health. This study uses multilevel data on 748 high-tech professionals in 120 teams to investigate relationships between team- and individual-level job conditions, work-family conflict, and four mental health outcomes (job satisfaction, emotional exhaustion, perceived stress, and psychological distress). We find that work-to-family conflict is socially patterned across teams, as are job satisfaction and emotional exhaustion. Team-level job conditions predict team-level outcomes, while individuals' perceptions of their job conditions are better predictors of individuals' work-to-family conflict and mental health. Work-to-family conflict operates as a partial mediator between job demands and mental health outcomes. Our findings suggest that organizational leaders concerned about presenteeism, sickness absences, and productivity would do well to focus on changing job conditions in ways that reduce job demands and work-to-family conflict in order to promote employees' mental health. We show that both work-to-family conflict and job conditions can be fruitfully framed as team characteristics, shared appraisals held in common by team members. This challenges the framing of work-to-family conflict as a "private trouble" and provides support for work-to-family conflict as a structural mismatch grounded in the social and temporal organization of work.

  4. IS WORK-FAMILY CONFLICT A MULTILEVEL STRESSOR LINKING JOB CONDITIONS TO MENTAL HEALTH? EVIDENCE FROM THE WORK, FAMILY AND HEALTH NETWORK

    Science.gov (United States)

    Moen, Phyllis; Kaduk, Anne; Kossek, Ellen Ernst; Hammer, Leslie; Buxton, Orfeu M.; O’Donnell, Emily; Almeida, David; Fox, Kimberly; Tranby, Eric; Oakes, J. Michael; Casper, Lynne

    2015-01-01

    Purpose Most research on the work conditions and family responsibilities associated with work-family conflict and other measures of mental health uses the individual employee as the unit of analysis. We argue that work conditions are both individual psychosocial assessments and objective characteristics of the proximal work environment, necessitating multilevel analyses of both individual- and team-level work conditions on mental health. Methodology/approach This study uses multilevel data on 748 high-tech professionals in 120 teams to investigate relationships between team- and individual-level job conditions, work-family conflict, and four mental health outcomes (job satisfaction, emotional exhaustion, perceived stress, and psychological distress). Findings We find that work-to-family conflict is socially patterned across teams, as are job satisfaction and emotional exhaustion. Team-level job conditions predict team-level outcomes, while individuals’ perceptions of their job conditions are better predictors of individuals’ work-to-family conflict and mental health. Work-to-family conflict operates as a partial mediator between job demands and mental health outcomes. Practical implications Our findings suggest that organizational leaders concerned about presenteeism, sickness absences, and productivity would do well to focus on changing job conditions in ways that reduce job demands and work-to-family conflict in order to promote employees’ mental health. Originality/value of the chapter We show that both work-to-family conflict and job conditions can be fruitfully framed as team characteristics, shared appraisals held in common by team members. This challenges the framing of work-to-family conflict as a “private trouble” and provides support for work-to-family conflict as a structural mismatch grounded in the social and temporal organization of work. PMID:25866431

  5. A Multiple Case Study Discovering Part-Time Faculties' Perceptions of Their Professional Needs, Working Conditions, Social Network, and Job Satisfaction at Three Community Colleges

    Science.gov (United States)

    Millner-Harlee, Tanya

    2010-01-01

    This study employed a multiple case study design to evaluate the perspectives of part-time faculties at three community colleges in the Northeast. The purpose of this study was to discover how needs, working conditions, and social networks influence the part-time faculties' job satisfaction. Maslow (1954), Bourdieu (1986), and Herzberg, Mausner,…

  6. Computer Simulation Model to Train Medical Personnel on Glucose Clamp Procedures.

    Science.gov (United States)

    Maghoul, Pooya; Boulet, Benoit; Tardif, Annie; Haidar, Ahmad

    2017-10-01

    A glucose clamp procedure is the most reliable way to quantify insulin pharmacokinetics and pharmacodynamics, but skilled and trained research personnel are required to frequently adjust the glucose infusion rate. A computer environment that simulates glucose clamp experiments can be used for efficient personnel training and development and testing of algorithms for automated glucose clamps. We built 17 virtual healthy subjects (mean age, 25±6 years; mean body mass index, 22.2±3 kg/m2), each comprising a mathematical model of glucose regulation and a unique set of parameters. Each virtual subject simulates plasma glucose and insulin concentrations in response to intravenous insulin and glucose infusions. Each virtual subject provides a unique response, and its parameters were estimated from combined intravenous glucose tolerance test-hyperinsulinemic-euglycemic clamp data using the Bayesian approach. The virtual subjects were validated by comparing their simulated predictions against data from 12 healthy individuals who underwent a hyperglycemic glucose clamp procedure. Plasma glucose and insulin concentrations were predicted by the virtual subjects in response to glucose infusions determined by a trained research staff performing a simulated hyperglycemic clamp experiment. The total amount of glucose infusion was indifferent between the simulated and the real subjects (85±18 g vs. 83±23 g; p=NS) as well as plasma insulin levels (63±20 mU/L vs. 58±16 mU/L; p=NS). The virtual subjects can reliably predict glucose needs and plasma insulin profiles during hyperglycemic glucose clamp conditions. These virtual subjects can be used to train personnel to make glucose infusion adjustments during clamp experiments. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

  7. The TCF C-clamp DNA binding domain expands the Wnt transcriptome via alternative target recognition.

    Science.gov (United States)

    Hoverter, Nate P; Zeller, Michael D; McQuade, Miriam M; Garibaldi, Angela; Busch, Anke; Selwan, Elizabeth M; Hertel, Klemens J; Baldi, Pierre; Waterman, Marian L

    2014-12-16

    LEF/TCFs direct the final step in Wnt/β-catenin signalling by recruiting β-catenin to genes for activation of transcription. Ancient, non-vertebrate TCFs contain two DNA binding domains, a High Mobility Group box for recognition of the Wnt Response Element (WRE; 5'-CTTTGWWS-3') and the C-clamp domain for recognition of the GC-rich Helper motif (5'-RCCGCC-3'). Two vertebrate TCFs (TCF-1/TCF7 and TCF-4/TCF7L2) use the C-clamp as an alternatively spliced domain to regulate cell-cycle progression, but how the C-clamp influences TCF binding and activity genome-wide is not known. Here, we used a doxycycline inducible system with ChIP-seq to assess how the C-clamp influences human TCF1 binding genome-wide. Metabolic pulse-labeling of nascent RNA with 4'Thiouridine was used with RNA-seq to connect binding to the Wnt transcriptome. We find that the C-clamp enables targeting to a greater number of gene loci for stronger occupancy and transcription regulation. The C-clamp uses Helper sites concurrently with WREs for gene targeting, but it also targets TCF1 to sites that do not have readily identifiable canonical WREs. The coupled ChIP-seq/4'Thiouridine-seq analysis identified new Wnt target genes, including additional regulators of cell proliferation. Thus, C-clamp containing isoforms of TCFs are potent transcriptional regulators with an expanded transcriptome directed by C-clamp-Helper site interactions. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  8. Delayed umbilical cord clamping after childbirth: potential benefits to baby's health

    Directory of Open Access Journals (Sweden)

    Uwins C

    2014-11-01

    Full Text Available Christina Uwins,1 David JR Hutchon2 1Department of Obstetrics and Gynaecology, Croydon University Hospital, Croydon, 2Department of Obstetrics, Darlington Memorial Hospital, Darlington, UKAbstract: Early cord clamping was initially introduced as part of the package of care known as “active management of the third stage”, which was implemented to reduce postpartum hemorrhage. It has now been shown to provide no benefit to the mother and to result in harm to the neonate. The clinical trial evidence relating to delayed cord clamping compared to immediate cord clamping is presented and the physiological rationale for delayed cord clamping is discussed in this paper. Most organizations (eg World Health Organization (WHO, Royal College of Obstetricians and Gynaecologists (RCOG, Resuscitation Council (UK,The International Federation of Gynecology and Obstetrics (FIGO, International Confederation of Midwives, International Liaison Committee on Resuscitation (ILCOR and the European Resuscitation Council now advise a delay of 1–3 minutes before clamping the cord in term and preterm infants, and clinicians need to be aware of this change. Healthy neonates benefit from a more physiological and gentle transition from placental to pulmonary respiration, and we explain why this benefit should be provided to all neonates until there is any evidence to the contrary. The harm of early cord clamping is not limited to anemia and iron deficiency, and evidence for a wide range of possible harms of early cord clamping is presented. The need for resuscitation is one of the most common concerns, and ways of overcoming these concerns are described.Keywords: transition, cord clamping, hypovolemia, intraventricular hemorrhage

  9. Patch Clamp: A Powerful Technique for Studying the Mechanism of Acupuncture

    Directory of Open Access Journals (Sweden)

    D. Zhang

    2012-01-01

    Full Text Available Cellular and molecular events can be investigated using electrophysiological techniques. In particular, the patch-clamp method provides detailed information. In addition, the patch-clamp technique has become a powerful method for investigating the mechanisms underlying the effects of acupuncture. In this paper, recent researches on how acupuncture might modulate electrophysiological responses in the central nervous system (CNS and affect peripheral structures are reviewed.

  10. [High-resolution patch-clamp technique based on feedback control of scanning ion conductance microscopy].

    Science.gov (United States)

    Yang, Xi; Liu, Xiao; Zhang, Xiao-Fan; Lu, Hu-Jie; Zhang, Yan-Jun

    2010-06-25

    The ion channels located on the cell fine structures play an important role in the physiological functions of cell membrane. However, it is impossible to achieve precise positioning on the nanometer scale cellular microstructures by conventional patch-clamp technique, due to the 200 nm resolution limit of optical microscope. To solve this problem, we have established a high-resolution patch-clamp technique, which combined commercial scanning ion conductance microscopy (SICM) and patch-clamp recording through a nanopipette probe, based on SICM feedback control. MDCK cells were used as observation object to test the capability of the technique. Firstly, a feedback controlled SICM nanopipette (approximately 150 MOmega) non-contactly scanned over a selected area of living MDCK cells monolayer to obtain high-resolution topographic images of microvilli and tight-junction microstructures on the MDCK cells monolayer. Secondly, the same nanopipette was non-contactly moved and precisely positioned over the microvilli or tight-junction microstructure under SICM feedback control. Finally, the SICM feedback control was switched off, the nanopipette slowly contacted with the cell membrane to get a patch-clamp giga-ohm sealing in the cell-attached patch-clamp configuration, and then performed ion channel recording as a normal patch-clamp electrode. The ion channel recordings showed that ion channels of microvilli microstructure opened at pipette holding potential of -100, -60, -40, 0, +40, +60, +100 mV (n=11). However, the opening of ion channels of tight-junction microstructure was not detected at pipette holding potential of -100, -40, 0, +40, +100 mV (n=9). These results suggest that our high-resolution patch-clamp technique can achieve accurate nanopipette positioning and nanometer scale high-resolution patch-clamp recording, which may provide a powerful tool to study the spatial distribution and functions of ion channel in the nanometer scale microstructures of living

  11. Automated whole-cell patch clamp electrophysiology of neurons in vivo

    OpenAIRE

    Kodandaramaiah, Suhasa B.; Franzesi, Giovanni Talei; Chow, Brian Y.; Boyden, Edward S.; Forest, Craig R.

    2012-01-01

    Whole-cell patch clamp electrophysiology of neurons is a gold standard technique for high-fidelity analysis of the biophysical mechanisms of neural computation and pathology but it requires great skill to perform. We have developed a robot that automatically performs patch clamping in vivo, algorithmically detecting cells by analyzing the temporal sequence of electrode impedance changes. We demonstrate good yield, throughput, and quality of automated intracellular recording in mouse cortex an...

  12. Automated whole-cell patch clamp electrophysiology of neurons in vivo

    Science.gov (United States)

    Kodandaramaiah, Suhasa B.; Franzesi, Giovanni Talei; Chow, Brian Y.; Boyden, Edward S.; Forest, Craig R.

    2012-01-01

    Whole-cell patch clamp electrophysiology of neurons is a gold standard technique for high-fidelity analysis of the biophysical mechanisms of neural computation and pathology but it requires great skill to perform. We have developed a robot that automatically performs patch clamping in vivo, algorithmically detecting cells by analyzing the temporal sequence of electrode impedance changes. We demonstrate good yield, throughput, and quality of automated intracellular recording in mouse cortex and hippocampus. PMID:22561988

  13. How is VR used to support training in industry? The INTUITION network of excellence working group on education and training

    NARCIS (Netherlands)

    Cobb, S.C.; Richir, S.; D'Cruz, M.; Klinger, E.; Day, A.; David, P.; Gardeux, F.; van den Broek, Egon; van der Voort, Mascha C.; Meijer, F.; Izkara, J.L.; Mavrikios, D.

    2008-01-01

    INTUITION is the European Network of Excellence on virtual reality and virtual environments applications for future workspaces. The purpose of the network is to gather expertise from partner members and determine the future research agenda for the development and use of virtual reality (VR)

  14. Locoregional Anesthesia for Carotid Endarterectomy: Identification of Patients with Intolerance to Cross-Clamping.

    Science.gov (United States)

    Dellaretti, Marcos; de Vasconcelos, Laura T; Dourado, Jules; de Souza, Renata F; Fontoura, Renato R; de Sousa, Atos A

    2016-03-01

    During carotid endarterectomy (CEA), carotid cross-clamping is performed to allow for artery incision and plaque removal. A small subgroup of patients can tolerate carotid occlusion for only a few seconds, if at all, without presenting neurologic deficit. These patients are described as having ''cross-clamp intolerance.'' The purpose of this study was to demonstrate the safety of locoregional anesthesia in identifying patients with cross-clamp intolerance and factors associated with this condition. From August 2008 to May 2010, 115 consecutive patients were submitted to CEA under locoregional anesthesia at the Santa Casa de Belo Horizonte; the procedure was performed by the main author. Patients who showed intolerance to internal carotid artery (ICA) occlusion for intolerance. Among the 115 participating patients, 9.6% (11 patients) showed intolerance to ICA occlusion and developed deficits in intolerance). The factor that was associated with cross-clamp intolerance was the mean degree of contralateral carotid stenosis, which was 57.5% for those who presented intolerance and 27.8% for those who tolerated ICA occlusion. Locoregional anesthesia is a safe method for identifying patients with cross-clamp intolerance. Patients with cross-clamp intolerance present contralateral stenosis that is greater on average than patients who readily tolerate carotid artery occlusion. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. A High Step-Down Interleaved Buck Converter with Active-Clamp Circuits for Wind Turbines

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2012-12-01

    Full Text Available In this paper, a high step-down interleaved buck coupled-inductor converter (IBCC with active-clamp circuits for wind energy conversion has been studied. In high step-down voltage applications, an IBCC can extend duty ratio and reduce voltage stresses on active switches. In order to reduce switching losses of active switches to improve conversion efficiency, a IBCC with soft-switching techniques is usually required. Compared with passive-clamp circuits, the IBCC with active-clamp circuits have lower switching losses and minimum ringing voltage of the active switches. Thus, the proposed IBCC with active-clamp circuits for wind energy conversion can significantly increase conversion efficiency. Finally, a 240 W prototype of the proposed IBCC with active-clamp circuits was built and implemented. Experimental results have shown that efficiency can reach as high as 91%. The proposed IBCC with active-clamp circuits is presented in high step-down voltage applications to verify the performance and the feasibility for energy conversion of wind turbines.

  16. Early identification of hERG liability in drug discovery programs by automated patch clamp

    Directory of Open Access Journals (Sweden)

    Timm eDanker

    2014-09-01

    Full Text Available Blockade of the cardiac ion channel coded by hERG can lead to cardiac arrhythmia, which has become a major concern in drug discovery and development. Automated electrophysiological patch clamp allows assessment of hERG channel effects early in drug development to aid medicinal chemistry programs and has become routine in pharmaceutical companies. However, a number of potential sources of errors in setting up hERG channel assays by automated patch clamp can lead to misinterpretation of data or false effects being reported. This article describes protocols for automated electrophysiology screening of compound effects on the hERG channel current. Protocol details and the translation of criteria known from manual patch clamp experiments to automated patch clamp experiments to achieve good quality data are emphasized. Typical pitfalls and artifacts that may lead to misinterpretation of data are discussed. While this article focuses on hERG channel recordings using the QPatch (Sophion A/S, Copenhagen, Denmark technology, many of the assay and protocol details given in this article can be transferred for setting up different ion channel assays by automated patch clamp and are similar on other planar patch clamp platforms.

  17. Patch-clamp technique to characterize ion channels in enlarged individual endolysosomes.

    Science.gov (United States)

    Chen, Cheng-Chang; Cang, Chunlei; Fenske, Stefanie; Butz, Elisabeth; Chao, Yu-Kai; Biel, Martin; Ren, Dejian; Wahl-Schott, Christian; Grimm, Christian

    2017-08-01

    According to proteomics analyses, more than 70 different ion channels and transporters are harbored in membranes of intracellular compartments such as endosomes and lysosomes. Malfunctioning of these channels has been implicated in human diseases such as lysosomal storage disorders, neurodegenerative diseases and metabolic pathologies, as well as in the progression of certain infectious diseases. As a consequence, these channels have engendered very high interest as future drug targets. Detailed electrophysiological characterization of intracellular ion channels is lacking, mainly because standard methods to analyze plasma membrane ion channels, such as the patch-clamp technique, are not readily applicable to intracellular organelles. Here we present a protocol detailing how to implement a manual patch-clamp technique for endolysosomal compartments. In contrast to the alternatively used planar endolysosomal patch-clamp technique, this method is a visually controlled, direct patch-clamp technique similar to conventional patch-clamping. The protocol assumes basic knowledge and experience with patch-clamp methods. Implementation of the method requires up to 1 week, and material preparation takes ∼2-4 d. An individual experiment (i.e., measurement of channel currents across the endolysosomal membrane), including control experiments, can be completed within 1 h. This excludes the time for endolysosome enlargement, which takes between 1 and 48 h, depending on the approach and cell type used. Data analysis requires an additional hour.

  18. Early identification of hERG liability in drug discovery programs by automated patch clamp.

    Science.gov (United States)

    Danker, Timm; Möller, Clemens

    2014-01-01

    Blockade of the cardiac ion channel coded by human ether-à-gogo-related gene (hERG) can lead to cardiac arrhythmia, which has become a major concern in drug discovery and development. Automated electrophysiological patch clamp allows assessment of hERG channel effects early in drug development to aid medicinal chemistry programs and has become routine in pharmaceutical companies. However, a number of potential sources of errors in setting up hERG channel assays by automated patch clamp can lead to misinterpretation of data or false effects being reported. This article describes protocols for automated electrophysiology screening of compound effects on the hERG channel current. Protocol details and the translation of criteria known from manual patch clamp experiments to automated patch clamp experiments to achieve good quality data are emphasized. Typical pitfalls and artifacts that may lead to misinterpretation of data are discussed. While this article focuses on hERG channel recordings using the QPatch (Sophion A/S, Copenhagen, Denmark) technology, many of the assay and protocol details given in this article can be transferred for setting up different ion channel assays by automated patch clamp and are similar on other planar patch clamp platforms.

  19. The development of high quality seals for silicon patch-clamp chips.

    Science.gov (United States)

    Sordel, Thomas; Kermarrec, Frédérique; Sinquin, Yann; Fonteille, Isabelle; Labeau, Michel; Sauter-Starace, Fabien; Pudda, Catherine; de Crécy, François; Chatelain, François; De Waard, Michel; Arnoult, Christophe; Picollet-D'hahan, Nathalie

    2010-10-01

    Planar patch-clamp is a two-dimensional variation of traditional patch-clamp. By contrast to classical glass micropipette, the seal quality of silicon patch-clamp chips (i.e. seal resistance and seal success rate) have remained poor due to the planar geometry and the nature of the substrate and thus partially obliterate the advantages related to planar patch-clamp. The characterization of physical parameters involved in seal formation is thus of major interest. In this paper, we demonstrate that the physical characterization of surfaces by a set of techniques (Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), surface energy (polar and dispersive contributions), drop angles, impedance spectroscopy, combined with a statistical design of experiments (DOE)) allowed us discriminating chips that provide relevant performances for planar patch-clamp analysis. Analyses of seal quality demonstrate that dispersive interactions and micropore size are the most crucial physical parameters of chip surfaces, by contrast to surface roughness and dielectric membrane thickness. This multi-scale study combined with electrophysiological validation of chips on a diverse set of cell-types expressing various ion channels (IRK1, hERG and hNa(v)1.5 channels) unveiled a suitable patch-clamp chip candidate. This original approach may inspire novel strategies for selecting appropriate surface parameters dedicated to biochips.

  20. Late umbilical cord clamping, neonatal hematocrit and Apgar scores: a randomized controlled trial.

    Science.gov (United States)

    Salari, Z; Rezapour, M; Khalili, N

    2014-01-01

    Based on current evidence, there is a little agreement on the best timing for after birth umbilical cord clamping. This study was designed to compare the impact of using two different times for cord clamping on hematocrit concentration and Apgar scores of the neonate. Fifty-six healthy full-term vaginally born neonates were allocated to early (10 seconds after delivery) and late (3 minutes after delivery) umbilical cord clamping groups in this randomized clinical trial. We recorded the length of the 3rd stage of labor and Apgar score at 5 minutes. Infant's hematocrit was measured at 2 and 18 hours of age. Neonatal hematocrit differed between the two groups. Late cord clamping group had greater hematocrit at 2 hours (45.5 ± 4 vs. 49.5 ± 4.4, P = 0.0003) and 18 hours (47.7 ± 5.5 vs. 52.9 ± 4.3, P = 0.0002). Apgar scores at 5 minutes (9.3 ± 0.6 vs. 9.4 ± 0.6, p = 0.5) and duration of delivery 3rd stage (10.2 ± 3.7 min vs. 8.9 ± 5 min, P = 0.2) did not differ between early and late cord clamping groups respectively. Late cord clamping leads to a significant increase in the hematocrit of the neonate but it does not have effects on Apgar score and duration of the 3rd stage of labor.

  1. The Significance and Impact of Innovation Networks of Academia and Business with a Special Emphasis on Work-Based Learning

    Directory of Open Access Journals (Sweden)

    Hogeforster Max A.

    2014-10-01

    Full Text Available The Europe 2020 Strategy puts the quality and relevance of education and training systems at the heart of EU’s efforts to improve innovation and competitiveness and to achieve intelligent, sustainable and inclusive growth. The development of partnerships between vocational schools or higher-education institutions and the business sector must be considered as a critical factor in identifying learning requirements, improving the relevance of education and facilitating access to education and learning. The growing lack of skills is one of the major challenges for companies that rely on more highly qualified personnel. To increase the cooperation between academia and the business world means to integrate small and medium-sized enterprises (SMEs, since 99.2 per cent of European businesses are SMEs. They are the blood cells of the European economy and are essential for growth, yet a very heterogeneous group that can only be integrated in cooperation networks by intermediate organisations which tackle the needs of this diverse group of businesses. Such a partnership of 17 universities and polytechnics, including the University of Latvia, was founded in 2010 and is shortly introduced as a best practice example.To stay competitive in the globalised world, companies need to be innovative and that requires cooperation with knowledge institutions. A survey conducted in 2013 revealed that one of the major obstacles for SMEs to improve their innovation capabilities is their inability to find qualified personnel. This corresponds to the huge challenges the labour markets face in Europe. Almost all countries report a growing lack of skilled workforce while at the same time youth unemployment is increasing. This gap between the current qualifications and the qualifications demanded by businesses sector can be overcome by a closer cooperation between enterprises and education facilities, on a national but also international level between Western and Eastern

  2. Revealing calcium fluxes by analyzing inhibition dynamics in action potential clamp.

    Science.gov (United States)

    Laasmaa, Martin; Birkedal, Rikke; Vendelin, Marko

    2016-11-01

    In cardiac excitation-contraction coupling (ECC), calcium enters the cytosol via L-type Ca 2+ channels (LTCC) and reverse Na + /Ca 2+ -exchange (NCX rev ), or is released from the sarcoplasmic reticulum (SR) by Ca 2+ -induced Ca 2+ -release (CICR). The magnitude of Ca 2+ influx via the different pathways varies with the state of the cell and is difficult to assess quantitatively, because changes in Ca 2+ influx through one pathway affect the others. In rainbow trout ventricular myocytes, the role of the SR has been uncertain for decades. The aim of this work was therefore two-fold: 1) to develop a method to quantify the Ca 2+ influx pathways, and 2) to determine the role of CICR from the SR in trout ventricular myocytes. The novelty of our developed method lies in the mathematical analysis of measured transsarcolemmal Ca 2+ currents and their impact on the corresponding Ca 2+ transient during gradual inhibition of the currents in action potential (AP) clamp. We tested the developed method using an excitation-contraction model and showed that the method was able to recover calcium fluxes from noisy synthetic data. We applied the approach to trout ventricular myocytes and quantified the relative contributions of different Ca 2+ influx pathways in ECC and determined the kinetics of these fluxes. Under baseline conditions, NCX rev is the main transmembrane Ca 2+ influx pathway contributing 29 ± 6% (of the Ca 2+ influx), LTCC 18 ± 7%, and CICR 53 ± 10% to overall Ca 2+ transient. Thus, NCX rev is an important regulator of contractility and probably plays a role in the negative force-frequency relationship of trout ventricular preparations. These results demonstrate that trout and neonatal mammalian cardiomyocytes resemble each other not only in terms of morphology and energetics but ECC as well. In summary, the developed method resolves the major problem how to separate highly interconnected fluxes in AP clamp and allows to study Ca 2+ fluxes in cardiomyocytes under

  3. Modeling CICR in rat ventricular myocytes: voltage clamp studies

    Directory of Open Access Journals (Sweden)

    Palade Philip T

    2010-11-01

    Full Text Available Abstract Background The past thirty-five years have seen an intense search for the molecular mechanisms underlying calcium-induced calcium-release (CICR in cardiac myocytes, with voltage clamp (VC studies being the leading tool employed. Several VC protocols including lowering of extracellular calcium to affect Ca2+ loading of the sarcoplasmic reticulum (SR, and administration of blockers caffeine and thapsigargin have been utilized to probe the phenomena surrounding SR Ca2+ release. Here, we develop a deterministic mathematical model of a rat ventricular myocyte under VC conditions, to better understand mechanisms underlying the response of an isolated cell to calcium perturbation. Motivation for the study was to pinpoint key control variables influencing CICR and examine the role of CICR in the context of a physiological control system regulating cytosolic Ca2+ concentration ([Ca2+]myo. Methods The cell model consists of an electrical-equivalent model for the cell membrane and a fluid-compartment model describing the flux of ionic species between the extracellular and several intracellular compartments (cell cytosol, SR and the dyadic coupling unit (DCU, in which resides the mechanistic basis of CICR. The DCU is described as a controller-actuator mechanism, internally stabilized by negative feedback control of the unit's two diametrically-opposed Ca2+ channels (trigger-channel and release-channel. It releases Ca2+ flux into the cyto-plasm and is in turn enclosed within a negative feedback loop involving the SERCA pump, regulating[Ca2+]myo. Results Our model reproduces measured VC data published by several laboratories, and generates graded Ca2+ release at high Ca2+ gain in a homeostatically-controlled environment where [Ca2+]myo is precisely regulated. We elucidate the importance of the DCU elements in this process, particularly the role of the ryanodine receptor in controlling SR Ca2+ release, its activation by trigger Ca2+, and its

  4. [Cardiac performance during insulin clamp: its evaluation by bioimpedance measurement].

    Science.gov (United States)

    Ferraro, S; Bellarosa, I; Genovese, S; Desiderio, A; D'Alto, M; Trimigliozzi, P; Chiariello, M

    1997-02-01

    Ten patients with dilated cardiomyopathy, 7 ischemic heart disease and 3 idiopathic (7 males and 3 females, mean age 54.8 +/- 11 years), were studied. An insulin euglycemic clamp was performed to evaluate the influence of insulin infusion on cardiac performance. All the subjects were in NYHA functional class II-III and had an ejection fraction < 60% at a previous echocardiographic examination. They were submitted to a noninvasive continuous cardiac output monitoring by variations of thoracic impedance at three stops: a basal evaluation (T0); 1.2 mU/kg/min insulin infusion (T1); 5 mU/kg/min insulin infusion (T2). Moreover at the same times Na+, K+, hematocrit (Hct) and catecholamines were measured in the plasma. The total time required for the study was about 4 hours. Cardiac performance improved as shown by a significant increase in T1 and T2 with respect to the basal condition (T0), of ejection fraction: 57.87 +/- 11.3% (T1) vs 52.25 +/- 14.1% (T0; p < 0.01); 59.5 +/- 10.7% (T2) vs 52.25 +/- 14.1% (T0; p < 0.005); stroke volume: 2.61 +/- 0.5 l/min/m2 (T1) vs 2.01 +/- 0.75 l/min/m2 (T0; p < 0.001); 3.35 +/- 0.66 l/min/m2 (T2) vs 2.01 +/- 0.75 l/min/m2 (T0; p < 0.001) and cardiac output: 41.14 +/- 9.1 ml/m2 (T1) vs 38.83 +/- 7.1 ml/m2 (T0; p < 0.01); 46.45 +/- 8.56 ml/m2 (T2) vs 38.83 +/- 7.1 ml/m2 (T0; p < 0.001). This improvement in cardiac function was not due to an increase in preload because end diastolic volume, Hct, Na+ did not differ through the study. Similarly, afterload measured as mean blood pressure did not decrease. Cardiac function improvement was obtained in the presence of increased catecholamines. In conclusion, exogenous insulin infusion was able, in the presence of euglycemic condition, to improve cardiac performance. This improvement could be due to a direct inotropic effect of insulin perhaps mediated by its metabolic properties on cardiac muscular cells and/or by increasing the cellular intake of Ca+2.

  5. A patch-clamp ASIC for nanopore-based DNA analysis.

    Science.gov (United States)

    Kim, Jungsuk; Maitra, Raj; Pedrotti, Kenneth D; Dunbar, William B

    2013-06-01

    In this paper, a fully integrated high-sensitivity patch-clamp system is proposed for single-molecule deoxyribonucleic acid (DNA) analysis using a nanopore sensor. This system is composed of two main blocks for amplification and compensation. The amplification block is composed of three stages: 1) a headstage, 2) a voltage-gain difference amplifier, and 3) a track-and-hold circuit, that amplify a minute ionic current variation sensed by the nanopore while the compensation block avoids the headstage saturation caused by the input parasitic capacitances during sensing. By employing design techniques novel for this application, such as an instrumentation--amplifier topology and a compensation switch, we minimize the deleterious effects of the input-offset voltage and the input parasitic capacitances while attaining hardware simplicity. This system is fabricated in a 0.35 μm 4M2P CMOS process and is demonstrated using an α-hemolysin protein nanopore for detection of individual molecules of single-stranded DNA that pass through the 1.5 nm-diameter pore. In future work, the refined system will functionalize single and multiple solid-state nanopores formed in integrated microfluidic devices for advanced DNA analysis, in scientific and diagnostic applications.

  6. On the Nonlinear Dynamics of a Doubly Clamped Microbeam near Primary Resonance

    KAUST Repository

    Jaber, Nizar

    2017-04-07

    This work aims to investigate theoretically and experimentally various nonlinear dynamic behaviors of a doubly clamped microbeam near its primary resonance. Mainly, we investigate the transition behavior from hardening, mixed, and then softening behavior. We show in a single frequency-response curve, under a constant voltage load, the transition from hardening to softening behavior demonstrating the dominance of the quadratic electrostatic nonlinearity over the cubic geometric nonlinearity of the beam as the motion amplitudes becomes large, which may lead eventually to dynamic pull-in. The microbeam is fabricated using polyimide as a structural layer coated with nickel from top and chromium and gold layers from the bottom. Frequency sweep tests are conducted for different values of DC bias revealing hardening, mixed, and softening behavior of the microbeam. A multi-mode Galerkin model combined with a shooting technique are implemented to generate the frequency response curves and to analyze the stability of the periodic motions using the Floquet theory. The simulated curves show good agreement with the experimental data.

  7. Classical and numerical approaches to determining V-section band clamp axial stiffness

    Science.gov (United States)

    Barrans, Simon M.; Khodabakhshi, Goodarz; Muller, Matthias

    2014-12-01

    V-band clamp joints are used in a wide range of applications to connect circular flanges, for ducts, pipes and the turbocharger housing. Previous studies and research on V-bands are either purely empirical or analytical with limited applicability on the variety of V-band design and working conditions. In this paper models of the V-band are developed based on the classical theory of solid mechanics and the finite element method to study the behaviour of theV-bands under axial loading conditions. The good agreement between results from the developed FEA and the classical model support the suitability of the latter to modelV-band joints with diameters greater than 110mm under axial loading. The results from both models suggest that the axial stiffness for thisV-band cross section reaches a peak value for V-bands with radius of approximately 150 mmacross a wide range of coefficients of friction. Also, it is shown that the coefficient of friction and the wedge angle have a significant effect on the axial stiffness of V-bands.

  8. Results from the carbon-land model intercomparison project (C-LAMP) and availability of the data on the earth system grid (ESG)

    Science.gov (United States)

    Hoffman, F. M.; Covey, C. C.; Fung, I. Y.; Randerson, J. T.; Thornton, P. E.; Lee, Y.-H.; Rosenbloom, N. A.; Stöckli, R. C.; Running, S. W.; Bernholdt, D. E.; Williams, D. N.

    2007-07-01

    This paper describes the Carbon-Land Model Intercomparison Project (C-LAMP) being carried out through a collaboration between the Community Climate System Model (CCSM) Biogeochemistry Working Group, a DOE SciDAC-2 project, and the DOE Program for Climate Model Diagnosis and Intercomparison (PCMDI). The goal of the project is to intercompare terrestrial biogeochemistry models running within the CCSM framework to determine the best set of processes to include in future versions of CCSM. As a part of the project, observational datasets are being collected and used to score the scientific performance of these models following a well-defined set of metrics. In addition, metadata standards for terrestrial biosphere models are being developed to support archival and distribution of the C-LAMP model output via the Earth System Grid (ESG). Progress toward completion of this project and preliminary results from the first set of experiments are reported.

  9. CAN TIGHT GROUPS AT WORK BE DETRIMENTAL? A THEORETICAL VIEW OF GOSSIP FROM THE NETWORK TIE STRENGTH AND DENSITY PERSPECTIVE

    OpenAIRE

    Alfred L. Luna; Decima Christine Garcia; Shih Yung Chou; Sara Jackson

    2013-01-01

    Given the importance of effective communication in organizational settings and the potential destructive impact of gossiping, greater research is needed to isolate those factors that enable negative gossip to occur. Although previous research has examined the effect of social network characteristics on gossip, the focus has not been on assessing the effect of social network tie strength and density on forms of gossip. In this article, we present a new theoretical framework for investigating h...

  10. Learning teams and networks: using information technology as a means of managing work process development in healthcare organizations.

    Science.gov (United States)

    Korhonen, Vesa; Paavilainen, Eija

    2002-01-01

    This article focuses on the introduction of team learning and shared knowledge creation using computer-based learning environments and teams as networks in the development of healthcare organizations. Using computer technology, care units can be considered learning teams and the hospital a network of those learning teams. Team learning requires that the healthcare workers' intellectual capital and personal competence be viewed as an important resource in developing the quality of action of the entire healthcare organization.

  11. Improvement in cardioplegic perfusion technique in single aortic clamping - initial results

    Science.gov (United States)

    Sobral, Marcelo Luiz Peixoto; dos Santos Júnior, Sérgio Francisco; de Sá, Juliano Cavalcante; Terrazas, Anderson da Silva; Trompieri, Daniel Francisco de Mendonça; de Sousa, Thierry Araújo Nunes; dos Santos, Gilmar Geraldo; Stolf, Noedir Antonio Groppo

    2014-01-01

    Introduction The most common method used for myocardial protection is administering cardioplegic solution in the coronary circulation. Nevertheless, protection may be achieved by intermittent perfusion of the coronary system with patient's own blood. The intermittent perfusion may be performed by multiple sequences of clamping and opening of the aortic clamp or due single clamping and accessory cannulation of the aortic root as in the improved technique proposed in this study, reperfusion without the need for multiple clamping of the aorta. Objective To evaluate the clinical outcome and the occurrence of neurological events in in-hospital patients submitted to myocardial revascularization surgery with the "improved technique" of intermittent perfusion of the aortic root with single clamping. Methods This is a prospective, cross-sectional, observational study that describes a myocardial management technique that consists of intermittent perfusion of the aortic root with single clamping in which 50 patients (mean age 58.5±7.19 years old) have been submitted to the myocardial revasculrization surgery under the proposed technique. Clinical and laboratory variables, pre- and post-surgery, have been assessed. Results The mean peak level of post-surgery CKMB was 51.64±27.10 U/L in the second post-surgery and of troponin I was 3.35±4.39 ng/ml in the fourth post-surgery, within normal limits. No deaths have occurred and one patient presented mild neurological disorder. Hemodynamic monitoring has not indicated any changes. Conclusion The myocardial revascularization surgery by perfusion with the improved technique with intermittent aortic root with single clamping proved to be safe, enabling satisfactory clinical results. PMID:25140473

  12. Pre-Descemets endothelial keratoplasty: the PDEK clamp for successful PDEK.

    Science.gov (United States)

    Dua, H S; Said, D G

    2017-07-01

    PurposeTo design and produce a clamp that enables good handling of donor sclera-corneal disks, allows air to be injected in the corneal stroma and consistently provides pre-Descemets endothelial keratoplasty (PDEK) tissue by creation of a type-1 big bubble (BB) avoiding a type-2BB by shutting the fenestrations in the periphery of the pre-Descemets layer and preventing escape of air.Patients and methodsA clamp with spring loaded handles attached to two rings of 9 mm diameter and 1 mm width with a side port for insertion of a needle for air injection was designed and produced. The clamp was tested in 20 human donor sclera-corneal disks and refined over three prototypes. The final design was used for PDEK in 8 patients.ResultsThe clamp was able to prevent any escape of air or the formation of a type-2BB. By preventing air leak, it provided better control over the volume of air injected allowing for consistent formation of a type-1BB, which could be expanded to its full diameter by advancing the tip of the needle into the bubble cavity. Centration of tissue in the clamp was important. The clamp was used successfully to obtain PDEK tissue from 8 donor sclara-corneal disks for transplant in three eyes with pseudophakic bullous keratopathy and five eyes with pseudophakia and Fuchs' endothelial dystrophy.ConclusionThe PDEK clamp is a simple and useful instrument that will give surgeons the confidence of consistently obtaining PDEK tissue with ease and without the risk of separating the Descemets membrane in a type-2BB.

  13. Conformational Changes of the Clamp of the Protein Translocation ATPase SecA.

    Science.gov (United States)

    Chen, Yu; Bauer, Benedikt W; Rapoport, Tom A; Gumbart, James C

    2015-07-17

    Post-translational protein translocation across the bacterial plasma membrane is mediated by the interplay of the SecA ATPase and the protein-conducting SecY channel. SecA consists of several domains, including two nucleotide-binding domains (NBD1 and NBD2), a polypeptide cross-linking domain (PPXD), a helical scaffold domain (HSD), and a helical wing domain (HWD). PPXD, HSD, and NBD2 form a clamp that positions the polypeptide substrate above the channel so that it can be pushed into the channel by a two-helix finger of the HSD. How the substrate is accommodated in the clamp during translocation is unclear. Here, we report a crystal structure of Thermotoga maritima SecA at 1.9 Å resolution. Structural analysis and free-energy calculations indicate that the new structure represents an intermediate state during the transition of the clamp from an open to a closed conformation. Molecular dynamics simulations show that closure of the clamp occurs in two phases, an initial movement of PPXD, HSD, and HWD as a unit, followed by a movement of PPXD alone toward NBD2. Simulations in the presence of a polypeptide chain show that the substrate associates with the back of the clamp by dynamic hydrogen bonding and that the clamp is laterally closed by a conserved loop of the PPXD. Mutational disruption of clamp opening or closure abolishes protein translocation. These results suggest how conformational changes of SecA allow substrate binding and movement during protein translocation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. The optimization based dynamic and cyclic working strategies for rechargeable wireless sensor networks with multiple base stations and wireless energy transfer devices.

    Science.gov (United States)

    Ding, Xu; Han, Jianghong; Shi, Lei

    2015-03-16

    In this paper, the optimal working schemes for wireless sensor networks with multiple base stations and wireless energy transfer devices are proposed. The wireless energy transfer devices also work as data gatherers while charging sensor nodes. The wireless sensor network is firstly divided into sub networks according to the concept of Voronoi diagram. Then, the entire energy replenishing procedure is split into the pre-normal and normal energy replenishing stages. With the objective of maximizing the sojourn time ratio of the wireless energy transfer device, a continuous time optimization problem for the normal energy replenishing cycle is formed according to constraints with which sensor nodes and wireless energy transfer devices should comply. Later on, the continuous time optimization problem is reshaped into a discrete multi-phased optimization problem, which yields the identical optimality. After linearizing it, we obtain a linear programming problem that can be solved efficiently. The working strategies of both sensor nodes and wireless energy transfer devices in the pre-normal replenishing stage are also discussed in this paper. The intensive simulations exhibit the dynamic and cyclic working schemes for the entire energy replenishing procedure. Additionally, a way of eliminating "bottleneck" sensor nodes is also developed in this paper.

  15. The Optimization Based Dynamic and Cyclic Working Strategies for Rechargeable Wireless Sensor Networks with Multiple Base Stations and Wireless Energy Transfer Devices

    Science.gov (United States)

    Ding, Xu; Han, Jianghong; Shi, Lei

    2015-01-01

    In this paper, the optimal working schemes for wireless sensor networks with multiple base stations and wireless energy transfer devices are proposed. The wireless energy transfer devices also work as data gatherers while charging sensor nodes. The wireless sensor network is firstly divided into sub networks according to the concept of Voronoi diagram. Then, the entire energy replenishing procedure is split into the pre-normal and normal energy replenishing stages. With the objective of maximizing the sojourn time ratio of the wireless energy transfer device, a continuous time optimization problem for the normal energy replenishing cycle is formed according to constraints with which sensor nodes and wireless energy transfer devices should comply. Later on, the continuous time optimization problem is reshaped into a discrete multi-phased optimization problem, which yields the identical optimality. After linearizing it, we obtain a linear programming problem that can be solved efficiently. The working strategies of both sensor nodes and wireless energy transfer devices in the pre-normal replenishing stage are also discussed in this paper. The intensive simulations exhibit the dynamic and cyclic working schemes for the entire energy replenishing procedure. Additionally, a way of eliminating “bottleneck” sensor nodes is also developed in this paper. PMID:25785305

  16. Illness Severity and Work Productivity Loss Among Working Adults With Medically Attended Acute Respiratory Illnesses: US Influenza Vaccine Effectiveness Network 2012-2013.

    Science.gov (United States)

    Petrie, Joshua G; Cheng, Caroline; Malosh, Ryan E; VanWormer, Jeffrey J; Flannery, Brendan; Zimmerman, Richard K; Gaglani, Manjusha; Jackson, Michael L; King, Jennifer P; Nowalk, Mary Patricia; Benoit, Joyce; Robertson, Anne; Thaker, Swathi N; Monto, Arnold S; Ohmit, Suzanne E

    2016-02-15

    Influenza causes significant morbidity and mortality, with considerable economic costs, including lost work productivity. Influenza vaccines may reduce the economic burden through primary prevention of influenza and reduction in illness severity. We examined illness severity and work productivity loss among working adults with medically attended acute respiratory illnesses and compared outcomes for subjects with and without laboratory-confirmed influenza and by influenza vaccination status among subjects with influenza during the 2012-2013 influenza season. Illnesses laboratory-confirmed as influenza (ie, cases) were subjectively assessed as more severe than illnesses not caused by influenza (ie, noncases) based on multiple measures, including current health status at study enrollment (≤7 days from illness onset) and current activity and sleep quality status relative to usual. Influenza cases reported missing 45% more work hours (20.5 vs 15.0; P productivity as impeded to a greater degree (6.0 vs 5.4; P productivity loss were noted for vaccinated subjects. Influenza illnesses were more severe and resulted in more missed work hours and productivity loss than illnesses not confirmed as influenza. Modest reductions in illness severity for vaccinated cases were observed. These findings highlight the burden of influenza illnesses and illustrate the importance of laboratory confirmation of influenza outcomes in evaluations of vaccine effectiveness. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  17. Implementation of the Mosaic network in work flow and management of a service radiotherapy oncology; Implementacion de la red mosaiq en el flujo de trabajo y gestion de un servicio de oncologia radioterapica

    Energy Technology Data Exchange (ETDEWEB)

    Alonso Iracheta, L.; Casa de Julian, M. A. de la; Samper Ots, P.; Panas Cabrera, M. D. de las; Jimenez Gonzalez, J. M.

    2013-07-01

    The Mosaic network contains a number of powerful and versatile tools for configuring the work flow and management tailored to the needs and working methods of each Service of Radiation Oncology. (Author)

  18. The experiences of working carers of older people regarding access to a web-based family care support network offered by a municipality.

    Science.gov (United States)

    Andersson, Stefan; Erlingsson, Christen; Magnusson, Lennart; Hanson, Elizabeth

    2017-09-01

    Policy makers in Sweden and other European Member States pay increasing attention as to how best support working carers; carers juggling providing unpaid family care for older family members while performing paid work. Exploring perceived benefits and challenges with web-based information and communication technologies as a means of supporting working carers' in their caregiving role, this paper draws on findings from a qualitative study. The study aimed to describe working carers' experiences of having access to the web-based family care support network 'A good place' (AGP) provided by the municipality to support those caring for an older family member. Content analysis of interviews with nine working carers revealed three themes: A support hub, connections to peers, personnel and knowledge; Experiencing ICT support as relevant in changing life circumstances; and Upholding one's personal firewall. Findings indicate that the web-based family care support network AGP is an accessible, complementary means of support. Utilising support while balancing caregiving, work obligations and responsibilities was made easier with access to AGP; enabling working carers to access information, psychosocial support and learning opportunities. In particular, it provided channels for carers to share experiences with others, to be informed, and to gain insights into medical and care issues. This reinforced working carers' sense of competence, helping them meet caregiving demands and see positive aspects in their situation. Carers' low levels of digital skills and anxieties about using computer-based support were barriers to utilising web-based support and could lead to deprioritising of this support. However, to help carers overcome these barriers and to better match web-based support to working carers' preferences and situations, web-based support must be introduced in a timely manner and must more accurately meet each working carer's unique caregiving needs. © 2016 Nordic College

  19. Clampe de Ganz no tratamento de urgência em lesões do anel pélvico Ganz clamps to treat emergencies in pelvic ring lesions

    Directory of Open Access Journals (Sweden)

    Gilberto José Cação Pereira

    2008-07-01

    Full Text Available OBJETIVO: Avaliar a eficiência do clampe de Ganz na estabilização e redução dos deslocamentos da pelve, quando utilizado no tratamento de urgência, além de aquilatar eventuais dificuldades e facilidades do método. MÉTODOS: O clampe de Ganz foi utilizado no tratamento de urgência em 31 pacientes com graves lesões do anel pélvico (Tile C associadas a importante instabilidade hemodinâmica. RESULTADO: Entre os pacientes, 27 (87,1% apresentaram evolução favorável, com estabilização, redução dos deslocamentos e compressão da região posterior do anel, além de estabilização hemodinâmica, e quatro (12,9% evoluíram para óbito. CONCLUSÃO: O clampe de Ganz mostrou-se eficiente ferramenta no tratamento de urgência das lesões do anel pélvico, por ser de concepção simples, de rápida colocação, não impedir ou dificultar procedimentos no abdome e, principalmente, por permitir a estabilização da pelve, redução dos deslocamentos e compressão na região posterior do anel, local onde ocorrem os maiores sangramentos, reduzindo-os ou eliminando-os.OBJECTIVE: To evaluate the effectiveness of Ganz clamp to stabilize and reduce pelvic dislocations in emergency situations, and to assess possible difficult and easy aspects of the method. METHOD: Ganz clamp was used in the emergency treatment of 31 patients with severe lesions of the pelvic ring (Tile C associated to major hemodynamic instability. RESULTS: Among the patients, 27 (87.1% presented a favorable evolution, with stabilization, reduction of dislocations, and compression of the posterior portion of the ring, and also hemodynamic stabilization, and 4 (12.9% died. CONCLUSION: The Ganz clamp was found to be an effective tool in the emergency treatment of pelvic ring lesions because it has an uncomplicated conception, allowing for a fast placement, because it does not prevent nor make it difficult for abdominal procedures, and most of all because it allows for the

  20. Functional dissection of synaptic circuits: in vivo patch-clamp recording in neuroscience.

    Science.gov (United States)

    Tao, Can; Zhang, Guangwei; Xiong, Ying; Zhou, Yi

    2015-01-01

    Neuronal activity is dominated by synaptic inputs from excitatory or inhibitory neural circuits. With the development of in vivo patch-clamp recording, especially in vivo voltage-clamp recording, researchers can not only directly measure neuronal activity, such as spiking responses or membrane potential dynamics, but also quantify synaptic inputs from excitatory and inhibitory circuits in living animals. This approach enables researchers to directly unravel different synaptic components and to understand their underlying roles in particular brain functions. Combining in vivo patch-clamp recording with other techniques, such as two-photon imaging or optogenetics, can provide even clearer functional dissection of the synaptic contributions of different neurons or nuclei. Here, we summarized current applications and recent research progress using the in vivo patch-clamp recording method and focused on its role in the functional dissection of different synaptic inputs. The key factors of a successful in vivo patch-clamp experiment and possible solutions based on references and our experiences were also discussed.

  1. A single electrode voltage, current- and patch-clamp amplifier with complete stable series resistance compensation.

    Science.gov (United States)

    Strickholm, A

    1995-01-01

    An input headstage for single electrode voltage and current clamping is described which permits selecting desired operational modes during an experiment. These include cell attached or whole cell patch clamping, single micro-electrode voltage or current clamping, potential recording, iontophoresis and voltammetry. Input electrode series resistance with the electrode inserted in a cell or during whole cell patch clamping can be measured at any time. The unique circuitry allows complete compensation of the series resistance with high frequency response. The input series electrode resistance can also vary considerably around an initially set 100% compensation with intrinsic stability. An accelerator 'supercharger' or 'booster circuit' is included which can shorten the rise time of membrane potential to the command potential by a hundredfold. This improves the recording of early ion channel currents. Feedback resistors are selected remotely for the specific experimental need. Signal resolution in patch clamping is that expected from the thermal noise of the feedback resistor and electrode to membrane seal resistance. This headstage circuitry design thus allows interchangeable modes of operation and parameters during an experiment to obtain optimal conditions for signal detection and frequency response.

  2. Clamping instability and van der Waals forces in carbon nanotube mechanical resonators.

    Science.gov (United States)

    Aykol, Mehmet; Hou, Bingya; Dhall, Rohan; Chang, Shun-Wen; Branham, William; Qiu, Jing; Cronin, Stephen B

    2014-05-14

    We investigate the role of weak clamping forces, typically assumed to be infinite, in carbon nanotube mechanical resonators. Due to these forces, we observe a hysteretic clamping and unclamping of the nanotube device that results in a discrete drop in the mechanical resonance frequency on the order of 5-20 MHz, when the temperature is cycled between 340 and 375 K. This instability in the resonant frequency results from the nanotube unpinning from the electrode/trench sidewall where it is bound weakly by van der Waals forces. Interestingly, this unpinning does not affect the Q-factor of the resonance, since the clamping is still governed by van der Waals forces above and below the unpinning. For a 1 μm device, the drop observed in resonance frequency corresponds to a change in nanotube length of approximately 50-65 nm. On the basis of these findings, we introduce a new model, which includes a finite tension around zero gate voltage due to van der Waals forces and shows better agreement with the experimental data than the perfect clamping model. From the gate dependence of the mechanical resonance frequency, we extract the van der Waals clamping force to be 1.8 pN. The mechanical resonance frequency exhibits a striking temperature dependence below 200 K attributed to a temperature-dependent slack arising from the competition between the van der Waals force and the thermal fluctuations in the suspended nanotube.

  3. Well-connected leaders: the impact of leaders' social network ties on LMX and members' work attitudes.

    Science.gov (United States)

    Venkataramani, Vijaya; Green, Stephen G; Schleicher, Deidra J

    2010-11-01

    We examined the proposition that leaders' social network ties in the larger organization influence the quality of their leader-member exchange (LMX) with their employees, which, in turn, impacts these employees' job satisfaction and turnover intentions. Using multilevel, multisource data from a field study of 184 bank employees nested within 42 branch managers, we found that leaders who had higher quality relationships with their bosses and who were more central in their peer networks were perceived by their subordinates as having greater status in the organization and, therefore, were able to form higher quality relationships with them. Further, the effects of the leaders' perceived status on LMX were stronger when subordinates were less central in their own peer network. Finally, LMX mediated the impact of leaders' perceived status in the organization on subordinates' job satisfaction and turnover intentions. Implications for theory and practice are discussed. (c) 2010 APA, all rights reserved.

  4. Combined Triplex/Duplex Invasion of Double-Stranded DNA by "Tail-Clamp" Peptide Nucleic Acid

    DEFF Research Database (Denmark)

    Bentin, Thomas; Larsen, H. J.; Nielsen, Peter E.

    2003-01-01

    as determined by T-m measurements. Binding to double-stranded (ds) DNA occurred by combined triplex and duplex invasion as analyzed by permanganate probing. Furthermore, C-50 measurements revealed that tail-clamp PNAs consistently bound the dsDNA target more efficiently, and kinetics experiments revealed......"Tail-clamp" PNAs composed of a short (hexamer) homopyrimidine triplex forming domain and a (decamer) mixed sequence duplex forming extension have been designed. Tail-clamp PNAs display significantly increased binding to single-stranded DNA compared with PNAs lacking a duplex-forming extension...... that this was due to a dramatically reduced dissociation rate of such complexes. Increasing the PNA net charge also increased binding efficiency, but unexpectedly, this increase was much more pronounced for tailless-clamp PNAs than for tail-clamp PNAs. Finally, shortening the tail-clamp PNA triplex invasion moiety...

  5. The use of artificial neural networks and multiple linear regression in modeling work-health relationships: translating theory into analytical practice

    OpenAIRE

    Karanika-Murray, M; Cox, T

    2010-01-01

    Although psychological theory acknowledges the existence of complex systems and the importance of nonlinear effects, linear statistical models have been traditionally used to examine relationships between environmental stimuli and outcomes. The way we analyse these relationships does not seem to reflect the way we conceptualize them. The present study investigated the application of connectionism (artificial neural networks) to modelling the relationships between work characteristics and empl...

  6. New graphical information system of the Lech Power Works. Implementation of Gradas-EVU for the recontrol and documentation of complex medium voltage networks

    Energy Technology Data Exchange (ETDEWEB)

    Oexl, W.

    1985-10-28

    The interactive graphical information system Gradas-EVU was developed for the Lech Power Works for monitoring and recontrolling the medium voltage network. A detailed description of the scope of the system was published in Elektrizitaetswirtschaft v. 84(4) (1985), pages 124-132. Here the author looks as the hardware and software concept in greater detail with special emphasis on the configuration installed at Lech. (orig.).

  7. Working memory performance of early MS patients correlates inversely with modularity increases in resting state functional connectivity networks.

    Science.gov (United States)

    Gamboa, O L; Tagliazucchi, E; von Wegner, F; Jurcoane, A; Wahl, M; Laufs, H; Ziemann, U

    2014-07-01

    Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating and neurodegenerative disorder of the central nervous system characterized by multifocal white matter brain lesions leading to alterations in connectivity at the subcortical and cortical level. Graph theory, in combination with neuroimaging techniques, has been recently developed into a powerful tool to assess the large-scale structure of brain functional connectivity. Considering the structural damage present in the brain of MS patients, we hypothesized that the topological properties of resting-state functional networks of early MS patients would be re-arranged in order to limit the impact of disease expression. A standardized dual task (Paced Auditory Serial Addition Task simultaneously performed with a paper and pencil task) was administered to study the interactions between behavioral performance and functional network re-organization. We studied a group of 16 early MS patients (35.3±8.3 years, 11 females) and 20 healthy controls (29.9±7.0 years, 10 females) and found that brain resting-state networks of the MS patients displayed increased network modularity, i.e. diminished functional integration between separate functional modules. Modularity correlated negatively with dual task performance in the MS patients. Our results shed light on how localized anatomical connectivity damage can globally impact brain functional connectivity and how these alterations can impair behavioral performance. Finally, given the early stage of the MS patients included in this study, network modularity could be considered a promising biomarker for detection of earliest-stage brain network reorganization, and possibly of disease progression. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. The interplay of primer-template DNA phosphorylation status and single-stranded DNA binding proteins in directing clamp loaders to the appropriate polarity of DNA.

    Science.gov (United States)

    Hayner, Jaclyn N; Douma, Lauren G; Bloom, Linda B

    2014-01-01

    Sliding clamps are loaded onto DNA by clamp loaders to serve the critical role of coordinating various enzymes on DNA. Clamp loaders must quickly and efficiently load clamps at primer/template (p/t) junctions containing a duplex region with a free 3'OH (3'DNA), but it is unclear how clamp loaders target these sites. To measure the Escherichia coli and Saccharomyces cerevisiae clamp loader specificity toward 3'DNA, fluorescent β and PCNA clamps were used to measure clamp closing triggered by DNA substrates of differing polarity, testing the role of both the 5'phosphate (5'P) and the presence of single-stranded binding proteins (SSBs). SSBs inhibit clamp loading by both clamp loaders on the incorrect polarity of DNA (5'DNA). The 5'P groups contribute selectivity to differing degrees for the two clamp loaders, suggesting variations in the mechanism by which clamp loaders target 3'DNA. Interestingly, the χ subunit of the E. coli clamp loader is not required for SSB to inhibit clamp loading on phosphorylated 5'DNA, showing that χ·SSB interactions are dispensable. These studies highlight a common role for SSBs in directing clamp loaders to 3'DNA, as well as uncover nuances in the mechanisms by which SSBs perform this vital role. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  9. Ion channels in small cells and subcellular structures can be studied with a smart patch-clamp system.

    OpenAIRE

    Gorelik, Julia; Gu, Yuchun; Spohr, Hilmar A; Shevchuk, Andrew I; Lab, Max J; Harding, Sian E; Edwards, Christopher R W; Whitaker, Michael; Moss, Guy W J; Benton, David C H; Sánchez, Daniel; Darszon, Alberto; Vodyanoy, Igor; Klenerman, David; Korchev, Yuri E

    2002-01-01

    We have developed a scanning patch-clamp technique that facilitates single-channel recording from small cells and submicron cellular structures that are inaccessible by conventional methods. The scanning patch-clamp technique combines scanning ion conductance microscopy and patch-clamp recording through a single glass nanopipette probe. In this method the nanopipette is first scanned over a cell surface, using current feedback, to obtain a high-resolution topographic image. This same pipette ...

  10. MutS/MutL crystal structure reveals that the MutS sliding clamp loads MutL onto DNA

    Science.gov (United States)

    Groothuizen, Flora S; Winkler, Ines; Cristóvão, Michele; Fish, Alexander; Winterwerp, Herrie HK; Reumer, Annet; Marx, Andreas D; Hermans, Nicolaas; Nicholls, Robert A; Murshudov, Garib N; Lebbink, Joyce HG; Friedhoff, Peter; Sixma, Titia K

    2015-01-01

    To avoid mutations in the genome, DNA replication is generally followed by DNA mismatch repair (MMR). MMR starts when a MutS homolog recognizes a mismatch and undergoes an ATP-dependent transformation to an elusive sliding clamp state. How this transient state promotes MutL homolog recruitment and activation of repair is unclear. Here we present a crystal structure of the MutS/MutL complex using a site-specifically crosslinked complex and examine how large conformational changes lead to activation of MutL. The structure captures MutS in the sliding clamp conformation, where tilting of the MutS subunits across each other pushes DNA into a new channel, and reorientation of the connector domain creates an interface for MutL with both MutS subunits. Our work explains how the sliding clamp promotes loading of MutL onto DNA, to activate downstream effectors. We thus elucidate a crucial mechanism that ensures that MMR is initiated only after detection of a DNA mismatch. DOI: http://dx.doi.org/10.7554/eLife.06744.001 PMID:26163658

  11. MutS/MutL crystal structure reveals that the MutS sliding clamp loads MutL onto DNA.

    Science.gov (United States)

    Groothuizen, Flora S; Winkler, Ines; Cristóvão, Michele; Fish, Alexander; Winterwerp, Herrie H K; Reumer, Annet; Marx, Andreas D; Hermans, Nicolaas; Nicholls, Robert A; Murshudov, Garib N; Lebbink, Joyce H G; Friedhoff, Peter; Sixma, Titia K

    2015-07-11

    To avoid mutations in the genome, DNA replication is generally followed by DNA mismatch repair (MMR). MMR starts when a MutS homolog recognizes a mismatch and undergoes an ATP-dependent transformation to an elusive sliding clamp state. How this transient state promotes MutL homolog recruitment and activation of repair is unclear. Here we present a crystal structure of the MutS/MutL complex using a site-specifically crosslinked complex and examine how large conformational changes lead to activation of MutL. The structure captures MutS in the sliding clamp conformation, where tilting of the MutS subunits across each other pushes DNA into a new channel, and reorientation of the connector domain creates an interface for MutL with both MutS subunits. Our work explains how the sliding clamp promotes loading of MutL onto DNA, to activate downstream effectors. We thus elucidate a crucial mechanism that ensures that MMR is initiated only after detection of a DNA mismatch.

  12. The Effect of an Added Mass on the Frequency Shifts of a Clamped-Clamped Microbeam for Bio-Mass Detection

    KAUST Repository

    Bouchaala, Adam M.

    2016-12-05

    We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped-clamped microbeams due to an added mass. Based on the Euler-Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes.

  13. ProofBook: An Online Social Network Based on Proof-of-Work and Friend-Propagation

    NARCIS (Netherlands)

    Biedermann, Sebastian; Karvelas, Nikolaos P.; Katzenbeisser, Stefan; Strufe, Thorsten; Peter, Andreas

    2014-01-01

    Online Social Networks (OSNs) enjoy high popularity, but their centralized architectures lead to intransparency and mistrust in the providers who can be the single point of failure. A solution is to adapt the OSN functionality to an underlying and fully distributed peer-to-peer (P2P) substrate.

  14. Cross-Cultural Collisions in Cyberspace: Case Studies of International Legal Issues for Educators Working in Globally Networked Learning Environments

    Science.gov (United States)

    Rife, Martine Courant

    2010-01-01

    This article explores some of the legal and law-related challenges educators face in designing, implementing, and sustaining globally networked learning environments (GNLEs) in the context of conflicting international laws on intellectual property and censorship/free speech. By discussing cases and areas involving such legal issues, the article…

  15. Innovations in Community-Based and Interdisciplinary Research: A Network Perspective on Innovation in Social Work Science

    Science.gov (United States)

    Rice, Eric; Petering, Robin; Stringfellow, Erin; Craddock, Jaih B.

    2017-01-01

    We present a preliminary theory of innovation in social work science. The focus of the piece is two case studies from our work that illustrate the social nature of innovations in the science of social work. This inductive theory focuses on a concept we refer to as transformative innovation, wherein two sets of individuals who possess different…

  16. Modelling the clamping force distribution among chips in press-pack IGBTs using the finite element method

    DEFF Research Database (Denmark)

    Hasmasan, Adrian Augustin; Busca, Christian; Teodorescu, Remus

    2012-01-01

    In this paper, a FEM (finite element method) based mechanical model for PP (press-pack) IGBTs (insulated gate bipolar transistors) is presented, which can be used to calculate the clamping force distribution among chips under various clamping conditions. The clamping force is an important parameter...... for the chip, because it influences contact electrical resistance, contact thermal resistance and power cycling capability. Ideally, the clamping force should be equally distributed among chips, in order to maximize the reliability of the PP IGBT. The model is built around a hypothetical PP IGBT with 9 chips...

  17. The essential Drosophila CLAMP protein differentially regulates non-coding roX RNAs in male and females.

    Science.gov (United States)

    Urban, Jennifer A; Doherty, Caroline A; Jordan, William T; Bliss, Jacob E; Feng, Jessica; Soruco, Marcela M; Rieder, Leila E; Tsiarli, Maria A; Larschan, Erica N

    2017-06-01

    Heterogametic species require chromosome-wide gene regulation to compensate for differences in sex chromosome gene dosage. In Drosophila melanogaster, transcriptional output from the single male X-chromosome is equalized to that of XX females by recruitment of the male-specific lethal (MSL) complex, which increases transcript levels of active genes 2-fold. The MSL complex contains several protein components and two non-coding RNA on the X ( roX) RNAs that are transcriptionally activated by the MSL complex. We previously discovered that targeting of the MSL complex to the X-chromosome is dependent on the chromatin-linked adapter for MSL proteins (CLAMP) zinc finger protein. To better understand CLAMP function, we used the CRISPR/Cas9 genome editing system to generate a frameshift mutation in the clamp gene that eliminates expression of the CLAMP protein. We found that clamp null females die at the third instar larval stage, while almost all clamp null males die at earlier developmental stages. Moreover, we found that in clamp null females roX gene expression is activated, whereas in clamp null males roX gene expression is reduced. Therefore, CLAMP regulates roX abundance in a sex-specific manner. Our results provide new insights into sex-specific gene regulation by an essential transcription factor.

  18. Significance of Shrinkage Induced Clamping Pressure in Fiber-Matrix Bonding in Cementitious Composite Materials

    DEFF Research Database (Denmark)

    Stang, Henrik

    1996-01-01

    inhomogeneity embedded in a matrix consisting of acementitious material undergoing shrinkage during hydration(autogenous shrinkage). Furthermore, the paperpresents the analysis necessary to perform an interpretation of the experimental results and which allows for thedetermination of the clamping pressure......The present paper accesses the significance of shrinkage inducedclamping pressure in fiber/matrix bonding mechanisms incementitious composite materials. The paper contains a description of an experimental setup whichallows mbox{measurement} of the clamping pressure which develops on anelastic...... acting on any elastic inhomogeneityembedded in the same cementitious matrix material. Fiber-shaped inhomogeneities are of special interest in cementitious composite material systems andresults are presented for the development of clamping pressure on three typical fiber types in two typical cementpastes...

  19. Influence of non-steady state during isoglycemic hyperinsulinemic clamp in hypertension. A LIFE substudy

    DEFF Research Database (Denmark)

    Olsen, M H; Andersen, U B; Wachtell, K

    1999-01-01

    We wanted to investigate whether time to steady state was reached within 2 h of insulin infusion during isoglycemic hyperinsulinemic clamp, comparing the glucose uptake index (M/IG) with Bergman's insulin sensitivity index (Sip). We performed a 2-h oral glucose tolerance test and a 3-h isoglycemic...... hyperinsulinemic clamp in 26 young, healthy subjects and 43 elderly patients with unmedicated essential hypertension and left ventricular hypertrophy. The 3-h Sip correlated strongly with the 2-h M/IG in the patients (r = 0.88, p .... Because the 2-h M/IG correlated strongly with the 3-h Sip with relatively narrow limits of agreement, it is a good measure of insulin sensitivity. However, a 2-h clamp results in lower insulin sensitivity values in elderly, hypertensive patients due to the fact that steady state is not reached...

  20. Flange joint system for SRF cavities utilizing high force spring clamps for low particle generation

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-09-05

    A flange joint system for SRF cavities. The flange joint system includes a set of high force spring clamps that produce high force on the simple flanges of Superconducting Radio Frequency (SRF) cavities to squeeze conventional metallic seals. The system establishes the required vacuum and RF-tight seal with minimum particle contamination to the inside of the cavity assembly. The spring clamps are designed to stay within their elastic range while being forced open enough to mount over the flange pair. Upon release, the clamps have enough force to plastically deform metallic seal surfaces and continue to a new equilibrium sprung dimension where the flanges remain held against one another with enough preload such that normal handling will not break the seal.

  1. The Power of Cooperation in International Paleoclimate Science: Examples from the PAGES 2k Network and the Ocean2k Working Group

    Science.gov (United States)

    Addison, J. A.

    2015-12-01

    The Past Global Changes (PAGES) project of IGBP and Future Earth supports research to understand the Earth's past environment to improve future climate predictions and inform strategies for sustainability. Within this framework, the PAGES 2k Network was established to provide a focus on the past 2000 years, a period that encompasses Medieval Climate Anomaly warming, Little Ice Age cooling, and recent anthropogenically-forced climate change. The results of these studies are used for testing earth system models, and for understanding decadal- to centennial-scale variability, which is needed for long-term planning. International coordination and cooperation among the nine regional Working Groups that make up the 2k Network has been critical to the success of PAGES 2k. The collaborative approach is moving toward scientific achievements across the regional groups, including: (i) the development of a community-driven open-access proxy climate database; (ii) integration of multi-resolution proxy records; (iii) development of multivariate climate reconstructions; and (iv) a leap forward in the spatial resolution of paleoclimate reconstructions. The last addition to the 2k Network, the Ocean2k Working Group has further innovated the collaborative approach by: (1) creating an open, receptive environment to discuss ideas exclusively in the virtual space; (2) employing an array of real-time collaborative software tools to enable communication, group document writing, and data analysis; (3) consolidating executive leadership teams to oversee project development and manage grassroots-style volunteer pools; and (4) embracing the value-added role that international and interdisciplinary science can play in advancing paleoclimate hypotheses critical to understanding future change. Ongoing efforts for the PAGES 2k Network are focused on developing new standards for data quality control and archiving. These tasks will provide the foundation for new and continuing "trans-regional" 2k

  2. Mapping physician Twitter networks: describing how they work as a first step in understanding connectivity, information flow, and message diffusion.

    Science.gov (United States)

    Mishori, Ranit; Singh, Lisa Oberoi; Levy, Brendan; Newport, Calvin

    2014-04-14

    Twitter is becoming an important tool in medicine, but there is little information on Twitter metrics. In order to recommend best practices for information dissemination and diffusion, it is important to first study and analyze the networks. This study describes the characteristics of four medical networks, analyzes their theoretical dissemination potential, their actual dissemination, and the propagation and distribution of tweets. Open Twitter data was used to characterize four networks: the American Medical Association (AMA), the American Academy of Family Physicians (AAFP), the American Academy of Pediatrics (AAP), and the American College of Physicians (ACP). Data were collected between July 2012 and September 2012. Visualization was used to understand the follower overlap between the groups. Actual flow of the tweets for each group was assessed. Tweets were examined using Topsy, a Twitter data aggregator. The theoretical information dissemination potential for the groups is large. A collective community is emerging, where large percentages of individuals are following more than one of the groups. The overlap across groups is small, indicating a limited amount of community cohesion and cross-fertilization. The AMA followers' network is not as active as the other networks. The AMA posted the largest number of tweets while the AAP posted the fewest. The number of retweets for each organization was low indicating dissemination that is far below its potential. To increase the dissemination potential, medical groups should develop a more cohesive community of shared followers. Tweet content must be engaging to provide a hook for retweeting and reaching potential audience. Next steps call for content analysis, assessment of the behavior and actions of the messengers and the recipients, and a larger-scale study that considers other medical groups using Twitter.

  3. The alcohol clamp: applications, challenges, and new directions--an RSA 2004 symposium summary.

    Science.gov (United States)

    Ramchandani, Vijay A; O'connor, Sean; Neumark, Yehuda; Zimmermann, Ulrich S; Morzorati, Sandra L; de Wit, Harriet

    2006-01-01

    This article summarizes the proceedings of a symposium organized and cochaired by Vijay Ramchandani and Sean O'Connor and presented at the 2004 Research Society on Alcoholism meeting in Vancouver, BC, Canada. The objectives of this symposium were: (1) to provide a rationale for the development and use of the alcohol clamp and the requirements for its use in alcohol challenge studies; (2) to highlight recent studies conducted using the alcohol clamp to identify sources of variation in the pharmacokinetics and pharmacodynamics of alcohol, as well as to address important research questions related to the relationship between the response to alcohol and the risk for alcoholism; and (3) to provide a perspective on progress, address limitations of the clamp, and identify new directions for alcohol challenge research. The symposium began with an introduction and overview of the alcohol clamp, by Vijay Ramchandani. This was followed by 4 presentations that highlighted recent studies conducted using the clamp including: (1) determination of the influence of alcohol dehydrogenase polymorphisms on alcohol elimination rates in a male Jewish population, by Yehuda Neumark; (2) examination of family history of alcoholism, recent drinking history, and levels and rates of administration as determinants of the response to alcohol and risk for alcoholism, by Sean O'Connor; (3) evaluation of the time course of ethanol intoxication on neuroendocrine function in humans, by Ulrich Zimmermann; and (4) a study of the effects of steady-state blood alcohol levels on auditory event-related potentials in rats, by Sandra Morzorati. Harriet de Wit summarized and discussed the research presented at the symposium and provided her perspective on future directions for research using the alcohol clamp.

  4. Efficient reinforcement learning of a reservoir network model of parametric working memory achieved with a cluster population winner-take-all readout mechanism.

    Science.gov (United States)

    Cheng, Zhenbo; Deng, Zhidong; Hu, Xiaolin; Zhang, Bo; Yang, Tianming

    2015-12-01

    The brain often has to make decisions based on information stored in working memory, but the neural circuitry underlying working memory is not fully understood. Many theoretical efforts have been focused on modeling the persistent delay period activity in the prefrontal areas that is believed to represent working memory. Recent experiments reveal that the delay period activity in the prefrontal cortex is neither static nor homogeneous as previously assumed. Models based on reservoir networks have been proposed to model such a dynamical activity pattern. The connections between neurons within a reservoir are random and do not require explicit tuning. Information storage does not depend on the stable states of the network. However, it is not clear how the encoded information can be retrieved for decision making with a biologically realistic algorithm. We therefore built a reservoir-based neural network to model the neuronal responses of the prefrontal cortex in a somatosensory delayed discrimination task. We first illustrate that the neurons in the reservoir exhibit a heterogeneous and dynamical delay period activity observed in previous experiments. Then we show that a cluster population circuit decodes the information from the reservoir with a winner-take-all mechanism and contributes to the decision making. Finally, we show that the model achieves a good performance rapidly by shaping only the readout with reinforcement learning. Our model reproduces important features of previous behavior and neurophysiology data. We illustrate for the first time how task-specific information stored in a reservoir network can be retrieved with a biologically plausible reinforcement learning training scheme. Copyright © 2015 the American Physiological Society.

  5. Whole cell voltage clamp recordings from cultured neurons of the supraoptic area of neonatal rat hypothalamus.

    Science.gov (United States)

    Cobbett, P; Mason, W T

    1987-04-14

    Whole-cell voltage and current clamp recordings were made from cultured neurons from the hypothalamic supraoptic area of neonatal rats. These neurons fired spontaneous Na+-action potentials, appearing as mixed Na+/K+-currents in voltage clamp. Isolated Na+-currents (less than 3 nA) were rapidly activated and inactivated during positive potential pulses from -80 mV. Two voltage-activated Ba2+-currents (less than 1 nA) were also recorded. These techniques offer a promising new approach for studying the striking electrical behavior of cultured hypothalamic neurons.

  6. Working Group 3: Operations Analysis for Systems of System within a Networked C2 Context: Introduction, Purpose, and Approach

    Science.gov (United States)

    2012-01-01

    Objective 1: Understand the impact of the application of traditional operational research techniques to networked C2 systems. • Objective 2: Develop...discussion would be in the Host Layer ( Application , Presentation, Session, Transport) to describe behavior; however, the impact of lower layers will be...CredentialEmployee(EmployeeID) DisableRemoteSystem(systemID) RideShare (Share/Match, Dynamic Route/Schedule, ServiceCoordination) ManageFleet(AVL/CAD, Planning

  7. Trust across Distance: A network approach to the development, distribution and maintenance of trust in distributed work groups

    OpenAIRE

    Julsrud, Tom Erik

    2008-01-01

    Work groups that consist of members localized in different geographical places, but maintain contact via electronic media, have become a widespread phenomenon within modern organizations. These are generally referred to as distributed work groups. Trust is increasingly considered to be a key characteristic for distributed groups, which can help improve the quality of the work, increase the effectiveness of the group, and prevent conflicts. At the same time, trust is a characteristic that can ...

  8. Selecting Strategies to Reduce High-Risk Unsafe Work Behaviors Using the Safety Behavior Sampling Technique and Bayesian Network Analysis.

    Science.gov (United States)

    Ghasemi, Fakhradin; Kalatpour, Omid; Moghimbeigi, Abbas; Mohammadfam, Iraj

    2017-03-04

    High-risk unsafe behaviors (HRUBs) have been known as the main cause of occupational accidents. Considering the financial and societal costs of accidents and the limitations of available resources, there is an urgent need for managing unsafe behaviors at workplaces. The aim of the present study was to find strategies for decreasing the rate of HRUBs using an integrated approach of safety behavior sampling technique and Bayesian networks analysis. A cross-sectional study. The Bayesian network was constructed using a focus group approach. The required data was collected using the safety behavior sampling, and the parameters of the network were estimated using Expectation-Maximization algorithm. Using sensitivity analysis and belief updating, it was determined that which factors had the highest influences on unsafe behavior. Based on BN analyses, safety training was the most important factor influencing employees' behavior at the workplace. High quality safety training courses can reduce the rate of HRUBs about 10%. Moreover, the rate of HRUBs increased by decreasing the age of employees. The rate of HRUBs was higher in the afternoon and last days of a week. Among the investigated variables, training was the most important factor affecting safety behavior of employees. By holding high quality safety training courses, companies would be able to reduce the rate of HRUBs significantly.

  9. Means to facilitate Smart Grid. Issue paper - working group 2; Denmark. Smart Grid Network; Virkemidler til fremme af Smart Grid. Issue paper, arbejdsgruppe 2

    Energy Technology Data Exchange (ETDEWEB)

    Hjortkjaer, A.-G. (DONG Energy, Fredericia (Denmark)); Madsen, Claus (ABB A/S, Skovlunde (Denmark)); Tang, J. (Dansk Fjernvarme, Kolding (Denmark)) (and others)

    2011-07-01

    The Smart Grid Network was established in 2010 by the Danish climate and energy minister tasked with developing recommendations for future actions and initiatives that make it possible to handle up to 50% electricity from wind energy in the power system in 2020. The task of working group 2 of the Smart Grid Network is stated as: ''The group will, building on existing surveys and analyses propose what new tools are needed in the years to 2020 to ensure intelligence in both transmission and distribution systems for the power grid in Denmark. Moreover, how public and private investments can be effectively brought into play. Among the measures envisaged are e.g. tariffs and charges''. The working group 2 identifies four areas that will promote the development of a smart grid. The proposed tools and means are related to: 1) Price signals to customers that reflect the value of consumption flexibility; 2) New economic regulation of network utilities' smart grid activities; 3) Taxes that support an effective electrification; 4) Effective activation of distributed storage and production. (LN)

  10. Extending the upper temperature range of gas chromatography with all-silicon microchip columns using a heater/clamp assembly.

    Science.gov (United States)

    Ghosh, Abhijit; Johnson, Jacob E; Nuss, Johnathan G; Stark, Brittany A; Hawkins, Aaron R; Tolley, Luke T; Iverson, Brian D; Tolley, H Dennis; Lee, Milton L

    2017-09-29

    Miniaturization of gas chromatography (GC) instrumentation is of interest because it addresses current and future issues relating to compactness, portability and field application. While incremental advancements continue to be reported in GC with columns fabricated in microchips (referred to in this paper as "microchip columns"), the current performance is far from acceptable. This lower performance compared to conventional GC is due to factors such as pooling of the stationary phase in corners of non-cylindrical channels, adsorption of sensitive compounds on incompletely deactivated surfaces, shorter column lengths and less than optimum interfacing to injector and detector. In this work, a GC system utilizing microchip columns was developed that solves the latter challenge, i.e., microchip interfacing to injector and detector. A microchip compression clamp was constructed to heat the microchip (i.e., primary heater), and seal the injector and detector fused silica interface tubing to the inlet and outlet ports of the microchip channels with minimum extra-column dead volume. This clamp allowed occasional operation up to 375°C and routine operation up to 300°C. The compression clamp was constructed of a low expansion alloy, Kovar™, to minimize leaking due to thermal expansion mismatch at the interface during repeated thermal cycling, and it was tested over several months for more than one hundred injections without forming leaks. A 5.9m long microcolumn with rectangular cross section of 158μm×80μm, which approximately matches a 100μm i.d. cylindrical fused silica column, was fabricated in a silicon wafer using deep reactive ion etching (DRIE) and high temperature fusion bonding; finally, the channel was coated statically with a 1% vinyl, 5% phenyl, 94% methylpolysiloxane stationary phase. High temperature separations of C10-C40 n-alkanes and a commercial diesel sample were demonstrated using the system under both temperature programmed GC (TPGC) and thermal

  11. Contribution of working memory in multiplication fact network in children may shift from verbal to visuo-spatial: A longitudinal investigation

    Directory of Open Access Journals (Sweden)

    Mojtaba eSoltanlou

    2015-07-01

    Full Text Available Number facts are commonly assumed to be verbally stored in an associative multiplication fact retrieval network. Prominent evidence for this assumption comes from so-called operand-related errors (e.g. 4 × 6 = 28. However, little is known about the development of this network in children and its relation to verbal and non-verbal memories. In a longitudinal design, we explored elementary school children from grades 3 and 4 in a multiplication verification task with the operand-related and -unrelated distractors. We examined the contribution of multiplicative fact retrieval by verbal and visuo-spatial short-term and working memory. Children in grade 4 showed smaller reaction times in all conditions. However, there was no significant difference in errors between grades. Contribution of verbal and visuo-spatial working memory also changed with grade. Multiplication correlated with verbal working memory and performance in grade 3 but with visuo-spatial working memory and performance in grade 4. We suggest that the relation to verbal working memory in grade 3 indicates primary linguistic learning of and access to multiplication in grade 3 which is probably based on verbal repetition of the multiplication table heavily practiced in grades 2 and 3. However, the relation to visuo-spatial semantic working memory in grade 4 suggests that there is a shift from verbal to visual and semantic learning in grade 4. This shifting may be induced because later in elementary school, multiplication problems are rather carried out via more written, i.e., visual tasks, which also involve executive functions. More generally, the current data indicates that mathematical development is not generally characterized by a steady progress in performance; rather verbal and non-verbal memory contributions of performance shift over time, probably due to different learning contents.

  12. Closed Loop Analysis Meta-Language Program (CLAMP)

    Science.gov (United States)

    2012-05-01

    distribution unlimited. attributes were added to the original spreadsheet data, that it could flow through to the generated xml, implanted in Excel using...plan with all degrees of freedom removed. Welding contains, as does any specific manufacturing process, certain assumptions about how the work may...Milling of welding surfaces and locator points 32 32 Milling Deburring of edges of welding surfaces if required Milling Measuring of machined

  13. Early vs delayed clamping of the umbilical cord in full term, preterm and very preterm infants

    DEFF Research Database (Denmark)

    Moller, N.K.; Weber, T.

    2008-01-01

    Randomized studies from 2006 and two meta-analyses published in 2007 agree that clamping of the umbilical cord can be delayed. For the preterm and very preterm infant benefits include less need for blood transfusion and less morbidity, especially for the very preterm male infant. For the term...

  14. Experimental and numerical analysis of clamped joints in front motorbike suspensions

    Directory of Open Access Journals (Sweden)

    Vincenzi N.

    2010-06-01

    Full Text Available Clamped joints are shaft-hub connections used, as an instance, in front motorbike suspensions to lock the steering plates with the legs and the legs with the wheel pin, by means of one or two bolts. The preloading force, produced during the tightening process, should be evaluated accurately, since it must lock safely the shaft, without overcoming the yielding point of the hub. Firstly, friction coefficients have been evaluated on “ad-hoc designed” specimens, by applying the Design of Experiment approach: the applied tightening torque has been precisely related to the imposed preloading force. Then, the tensile state of clamps have been evaluated both via FEM and by leveraging some design formulae proposed by the Authors as function of the preloading force and of the clamp geometry. Finally, the results have been compared to those given by some strain gauges applied on the tested clamps: the discrepancies between numerical analyses, the design formulae and the experimental results remains under a threshold of 10%.

  15. Fundamentals of a Multi-Phase, Neutral-Point Clamped Multilevel ...

    African Journals Online (AJOL)

    The conventional five-level diode-clamped inverter suffers from the problem of many active power switches when extended to multiphase system. As a consequence, increasing number of gate drive circuits are required; resulting in complex system circuitry. This paper presents the fundamentals of a multiphase, neutral ...

  16. Acute hypotension induced by aortic clamp vs. PTH provokes distinct proximal tubule Na+ transporter redistribution patterns

    DEFF Research Database (Denmark)

    Leong, Patrick K K; Yang, Li E; Lin, Harrison W

    2004-01-01

    in renal cortical membranes fractionated on sorbitol density gradients. Aortic clamp-induced acute hypotension (from 100 +/- 3 to 78 +/- 2 mmHg) provoked a 62% decrease in urine output and a significant decrease in volume flow from the proximal tubule detected as a 66% decrease in endogenous lithium......-density membranes enriched in apical markers. PTH at much lower doses (

  17. Emergent management of APC-2 pelvic ring injuries with an anteriorly placed C-clamp.

    Science.gov (United States)

    Richard, Marc J; Tornetta, Paul

    2009-01-01

    Can anteriorly placed pelvic C-clamps be used successfully in the emergent management of APC-2 pelvic fractures? Prospective cohort. Level 1 trauma center. A single-surgeon series of 24 patients with an anteroposterior compression type 2 pelvic fracture. Application of an anteriorly placed pelvic C-clamp within 2 hours of presentation. Response to hypotension, complications related to pin placement, application time, and symphyseal reduction measured on anteroposterior radiograph. Twenty-four patients with a mean age of 29 years (14-58 years) had an APC-2 pelvic fracture diagnosed by an anteroposterior radiograph of the pelvis on presentation. All patients were emergently managed with an anteriorly placed C-clamp applied in the emergency room (10), angiography suite (9), or operating room (5). Eleven patients presented with hypotension (systolic blood pressure elevation of their blood pressure of 23 mm Hg (10-44 mm Hg). The symphyseal separation was reduced from a mean of 4.5 cm (3-9 cm) to pelvic C-clamp can be placed anteriorly as a part of the early management of APC-2 pelvic fractures with a short application time in a variety of patient care areas.

  18. Cyclic peptide inhibitors of the β-sliding clamp in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Kjelstrup, Susanne; Hansen, Paula Melo Paulon; Thomsen, Line Elnif

    2013-01-01

    , from a library generated by the split intein-mediated circular ligation of peptides and proteins technology, were found to interfere with dimerization of the β-sliding clamp of the replisome. Two 8-mer peptides were analyzed in more detail. Both inhibited DNA replication, led to SOS induction, altered...

  19. Enhanced Buck-Boost Three-Level Neutral-Point-Clamped Inverters

    DEFF Research Database (Denmark)

    Tan, K. K.; Gao, F.; Chiang Loh, Poh

    2009-01-01

    In traditional three-level neutral-point-clamped (NPC) inverters, a major issue is capacitor voltage imbalance, which results in low order harmonics. The compensation of the capacitor voltages often require additional control complexity, which cannot be conveniently implemented. The "alternative...

  20. Electrophysiological analysis of mammalian cells expressing hERG using automated 384-well-patch-clamp.

    Science.gov (United States)

    Haraguchi, Yuji; Ohtsuki, Atsushi; Oka, Takayuki; Shimizu, Tatsuya

    2015-12-16

    An in vitro electrophysiological assay system, which can assess compound effects and thus show cardiotoxicity including arrhythmia risks of test drugs, is an essential method in the field of drug development and toxicology. In this study, high-throughput electrophysiological recordings of human embryonic kidney (HEK 293) cells and Chinese hamster ovary (CHO) cells stably expressing human ether-a-go-go related gene (hERG) were performed utilizing an automated 384-well-patch-clamp system, which records up to 384 cells simultaneously. hERG channel inhibition, which is closely related to a drug-induced QT prolongation and is increasing the risk of sudden cardiac death, was investigated in the high-throughput screening patch-clamp system. In the automated patch-clamp measurements performed here, Kv currents were investigated with high efficiency. Various hERG channel blockers showed concentration-dependent inhibition, the 50 % inhibitory concentrations (IC50) of those blockers were in good agreement with previous reports. The high-throughput patch-clamp system has a high potential in the field of pharmacology, toxicology, and cardiac physiology, and will contribute to the acceleration of pharmaceutical drug development and drug safety testing.