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Sample records for cross bridges contribute

  1. The contributions of filaments and cross-bridges to sarcomere compliance in skeletal muscle

    PubMed Central

    Brunello, Elisabetta; Caremani, Marco; Melli, Luca; Linari, Marco; Fernandez-Martinez, Manuel; Narayanan, Theyencheri; Irving, Malcolm; Piazzesi, Gabriella; Lombardi, Vincenzo; Reconditi, Massimo

    2014-01-01

    Force generation in the muscle sarcomere is driven by the head domain of the myosin molecule extending from the thick filament to form cross-bridges with the actin-containing thin filament. Following attachment, a structural working stroke in the head pulls the thin filament towards the centre of the sarcomere, producing, under unloaded conditions, a filament sliding of ∼11 nm. The mechanism of force generation by the myosin head depends on the relationship between cross-bridge force and movement, which is determined by compliances of the cross-bridge (Ccb) and filaments. By measuring the force dependence of the spacing of the high-order myosin- and actin-based X-ray reflections from sartorius muscles of Rana esculenta we find a combined filament compliance (Cf) of 13.1 ± 1.2 nm MPa−1, close to recent estimates from single fibre mechanics (12.8 ± 0.5 nm MPa−1). Ccb calculated using these estimates is 0.37 ± 0.12 nm pN−1, a value fully accounted for by the compliance of the myosin head domain, 0.38 ± 0.06 nm pN−1, obtained from the intensity changes of the 14.5 nm myosin-based X-ray reflection in response to 3 kHz oscillations imposed on single muscle fibres in rigor. Thus, a significant contribution to Ccb from the myosin tail that joins the head to the thick filament is excluded. The low Ccb value indicates that the myosin head generates isometric force by a small sub-step of the 11 nm stroke that drives filament sliding at low load. The implications of these results for the mechanism of force generation by myosins have general relevance for cardiac and non-muscle myosins as well as for skeletal muscle. PMID:25015916

  2. Cooperative cross-bridge activation of thin filaments contributes to the Frank-Starling mechanism in cardiac muscle.

    PubMed

    Smith, L; Tainter, C; Regnier, M; Martyn, D A

    2009-05-01

    Myosin cross-bridges play an important role in the regulation of thin-filament activation in cardiac muscle. To test the hypothesis that sarcomere length (SL) modulation of thin-filament activation by strong-binding cross-bridges underlies the Frank-Starling mechanism, we inhibited force and strong cross-bridge binding to intermediate levels with sodium vanadate (Vi). Force and stiffness varied proportionately with [Ca(2+)] and [Vi]. Increasing [Vi] (decreased force) reduced the pCa(50) of force-[Ca(2+)] relations at 2.3 and 2.0 microm SL, with little effect on slope (n(H)). When maximum force was inhibited to approximately 40%, the effects of SL on force were diminished at lower [Ca(2+)], whereas at higher [Ca(2+)] (pCa < 5.6) the relative influence of SL on force increased. In contrast, force inhibition to approximately 20% significantly reduced the sensitivity of force-[Ca(2+)] relations to changes in both SL and myofilament lattice spacing. Strong cross-bridge binding cooperatively induced changes in cardiac troponin C structure, as measured by dichroism of 5' iodoacetamido-tetramethylrhodamine-labeled cardiac troponin C. This apparent cooperativity was reduced at shorter SL. These data emphasize that SL and/or myofilament lattice spacing modulation of the cross-bridge component of cardiac thin-filament activation contributes to the Frank-Starling mechanism. PMID:19413974

  3. LOOKING WNW, CHEVROLET AVENUE BRIDGE CROSSING FLINT RIVER. BRIDGE CONNECTED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOOKING WNW, CHEVROLET AVENUE BRIDGE CROSSING FLINT RIVER. BRIDGE CONNECTED NORTH AND SOUTH PORTIONS OF FACTORY COMPLEX. DANIEL LUTEN DESIGNED THE BRIDGE, AND ILLINOIS BRIDGE COMPANY BUILT IT IN 1918. THE BRIDGE WAS THE SITE OF THE BATTLE OF RUNNING BULLS IN THE 1936-1937 GM SIT DOWN STRIKE. - Delphi Flint West, 300 Chevrolet Avenue, Flint, Genesee County, MI

  4. Passive tension and stiffness of vertebrate skeletal and insect flight muscles: the contribution of weak cross-bridges and elastic filaments.

    PubMed Central

    Granzier, H L; Wang, K

    1993-01-01

    Tension and dynamic stiffness of passive rabbit psoas, rabbit semitendinosus, and waterbug indirect flight muscles were investigated to study the contribution of weak-binding cross-bridges and elastic filaments (titin and minititin) to the passive mechanical behavior of these muscles. Experimentally, a functional dissection of the relative contribution of actomyosin cross-bridges and titin and minititin was achieved by 1) comparing mechanically skinned muscle fibers before and after selective removal of actin filaments with a noncalcium-requiring gelsolin fragment (FX-45), and 2) studying passive tension and stiffness as a function of sarcomere length, ionic strength, temperature, and the inhibitory effect of a carboxyl-terminal fragment of smooth muscle caldesmon. Our data show that weak bridges exist in both rabbit skeletal muscle and insect flight muscle at physiological ionic strength and room temperature. In rabbit psoas fibers, weak bridge stiffness appears to vary with both thin-thick filament overlap and with the magnitude of passive tension. Plots of passive tension versus passive stiffness are multiphasic and strikingly similar for these three muscles of distinct sarcomere proportions and elastic proteins. The tension-stiffness plot appears to be a powerful tool in discerning changes in the mechanical behavior of the elastic filaments. The stress-strain and stiffness-strain curves of all three muscles can be merged into one, by normalizing strain rate and strain amplitude of the extensible segment of titin and minititin, further supporting the segmental extension model of resting tension development. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 PMID:8298040

  5. OUTERBRIDGE CROSSING BRIDGE LINED UP WITH MANHATTAN SKYLINE IN MIDDLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OUTERBRIDGE CROSSING BRIDGE LINED UP WITH MANHATTAN SKYLINE IN MIDDLE OF HORIZON, VERRAZANO NARROWS BRIDGE TO THE RIGHT - Outerbridge Crossing Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

  6. Bridge over Troubled Water: Guidance Crosses

    ERIC Educational Resources Information Center

    Amundson, Norm

    2008-01-01

    This article is based on a keynote presentation at an international conference where the focus was cross-over career guidance. Simon and Garfunkel's popular song, "Bridge over troubled water", was used as a metaphor for exploring the cross-over theme. Some of the concepts under consideration included the working alliance, the importance of a…

  7. 33 CFR 118.90 - Bridges crossing channel obliquely.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Bridges crossing channel obliquely. 118.90 Section 118.90 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely....

  8. 33 CFR 118.90 - Bridges crossing channel obliquely.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bridges crossing channel obliquely. 118.90 Section 118.90 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely....

  9. 33 CFR 118.90 - Bridges crossing channel obliquely.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Bridges crossing channel obliquely. 118.90 Section 118.90 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely....

  10. 33 CFR 118.90 - Bridges crossing channel obliquely.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Bridges crossing channel obliquely. 118.90 Section 118.90 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely....

  11. 33 CFR 118.90 - Bridges crossing channel obliquely.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Bridges crossing channel obliquely. 118.90 Section 118.90 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely....

  12. Contributions of Diesel Truck Emissions to Indoor Elemental Carbon Concentrations in Home Proximate to Ambassador Bridge

    EPA Science Inventory

    Ambassador Bridge, connecting Detroit, Michigan and Windsor, Ontario, is the busiest international commercial vehicle crossing in North America, with a large percentage of heavy duty diesel trucks. This study seeks to examine the contribution of diesel truck traffic across Ambass...

  13. Aerial view of the entire bridge crossing the Tennessee River ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Aerial view of the entire bridge crossing the Tennessee River looking up river. The swing bridge, when open, permits river navigational traffic to ply the river. Construction of a replacement bridge, to be located 93.27 feet down river, has now started. - Bridgeport Swing Span Bridge, Spanning Tennessee River, Bridgeport, Jackson County, AL

  14. NEW JERSEY APPROACH TO OUTERBRIDGE CROSSING BRIDGE, NOTE DISTANT HORIZON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    NEW JERSEY APPROACH TO OUTERBRIDGE CROSSING BRIDGE, NOTE DISTANT HORIZON NEW YORK SKYLINE AND ALMOST IN THE MIDDLE OF THE HORIZON THE TWIN TOWERS OF THE VERRAZANO-NARROWS BRIDGE - Outerbridge Crossing Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

  15. Limestone and bronze "Mississippi River Crossing" Bridge plaque located at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Limestone and bronze "Mississippi River Crossing" Bridge plaque located at North corner of Administration Building site - Huey P. Long Bridge, Administration Building, 5100 Jefferson Highway, Jefferson, Jefferson Parish, LA

  16. 21. View northwest under bridge showing steel girders, cross beams, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. View northwest under bridge showing steel girders, cross beams, bracing, and walkway of west approach span. - Yellow Mill Bridge, Spanning Yellow Mill Channel at Stratford Avenue, Bridgeport, Fairfield County, CT

  17. 20. View southwest under bridge showing steel girder, cross beams, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. View southwest under bridge showing steel girder, cross beams, and bracing of bascule leaves. - Yellow Mill Bridge, Spanning Yellow Mill Channel at Stratford Avenue, Bridgeport, Fairfield County, CT

  18. View of Steel Flume Bridge #2 crossing over wash. Looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Steel Flume Bridge #2 crossing over wash. Looking downstream, southwest - Childs-Irving Hydroelectric Project, Childs System, Flume Bridge No. 2, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

  19. View of Steel Flume Bridge #3 crossing over Sally May ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Steel Flume Bridge #3 crossing over Sally May Wash. Looking northwest - Childs-Irving Hydroelectric Project, Childs System, Flume Bridge No. 3, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

  20. 2. GENERAL VIEW OF MOVEABLE BRIDGES CROSSING THE SOUTH BRANCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. GENERAL VIEW OF MOVEABLE BRIDGES CROSSING THE SOUTH BRANCH OF THE CHICAGO RIVER, LOOKING SOUTH FROM THE SEARS TOWER - Chicago River Bascule Bridges, Spanning Chicago River & its north & south branches, Chicago, Cook County, IL

  1. Bridge No. 1655, Tenth Potomac Crossing, which now carries the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bridge No. 1655, Tenth Potomac Crossing, which now carries the Western Maryland Scenic Railroad. I-68 viaduct at left through Cumberland; WV 28 bridge into Ridgeley, West Virginia in foreground. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  2. GENERAL VIEW OF BRIDGE CROSSING OF TUMALO FEED CANAL, TWIN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GENERAL VIEW OF BRIDGE CROSSING OF TUMALO FEED CANAL, TWIN FLUME'S OUTLET ROCK FOOTING ON RIGHT CANAL BANK. LOOKING WEST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

  3. ANOTHER DETAIL OF THE BRIDGE UNDERSIDE, IBEAM AND WOODEN CROSS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ANOTHER DETAIL OF THE BRIDGE UNDERSIDE, I-BEAM AND WOODEN CROSS BEAM CONSTRUCTION. 69 - Burlington Northern Santa Fe Railroad, Cajon Subdivision, Structure No. 66.4, Between Cajon Summit and Keenbrook, Devore, San Bernardino County, CA

  4. DETAIL OF UNDERSIDE OF BRIDGE SHOWING IBEAMS, WOODEN CROSS BEAMS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF UNDERSIDE OF BRIDGE SHOWING I-BEAMS, WOODEN CROSS BEAMS, AND PART OF WING WALL. 68 - Burlington Northern Santa Fe Railroad, Cajon Subdivision, Structure No. 66.4, Between Cajon Summit and Keenbrook, Devore, San Bernardino County, CA

  5. A general elevation view of the entire railroad bridge crossing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    A general elevation view of the entire railroad bridge crossing the Tennessee River with the center/pivot pier of the 364' - 0-1/2' swing bridge positioned in the center of the river. With the bridge in the open position, navigational river traffic can continue down river by going through a 145-foot horizontal opening on each side of the pivot pier, provided the opening provides the necessary clearance required. Note: The two (2) middle supports on the center/pivot round pier. - Bridgeport Swing Span Bridge, Spanning Tennessee River, Bridgeport, Jackson County, AL

  6. 57. View of road bridge crossing lined canal from south ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    57. View of road bridge crossing lined canal from south side of lined canal, looking northeast. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  7. 33. General view of flume from vehicular bridge crossing the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. General view of flume from vehicular bridge crossing the flume, just west of lumber storage shed, looking west. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  8. South elevation of Bridge No. 1655, Tenth Potomac Crossing, with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    South elevation of Bridge No. 1655, Tenth Potomac Crossing, with Ridgely, West Virginia (left) and Cumberland, Maryland (right) in background, looking northwest. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  9. Bridge No. 1625, Eighth Potomac Crossing, looking east towards West ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bridge No. 1625, Eighth Potomac Crossing, looking east towards West Virginia and the west portal of Tunnel No. 1624, Welton Tunnel, beneath the Greater Cumberland Regional Airport. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  10. Equilibrium muscle cross-bridge behavior. Theoretical considerations.

    PubMed Central

    Schoenberg, M

    1985-01-01

    We have developed a model for the equilibrium attachment and detachment of myosin cross-bridges to actin that takes into account the possibility that a given cross-bridge can bind to one of a number of actin monomers, as seems likely, rather than to a site on only a single actin monomer, as is often assumed. The behavior of this multiple site model in response to constant velocity, as well as instantaneous stretches, was studied and the influence of system parameters on the force response explored. It was found that in the multiple site model the detachment rate constant has considerably greater influence on the mechanical response than the attachment rate constant. It is shown that one can obtain information about the detachment rate constants either by examining the relationship between the apparent stiffness and duration of stretch for constant velocity stretches or by examining the force-decay rate constants following an instantaneous stretch. The main effect of the attachment rate constant is to scale the mechanical response by influencing the number of attached cross-bridges. The significance of the modeling for the interpretation of experimental results is discussed. PMID:4041539

  11. 1. NORTH APPROACH TO SE 14TH STREET BRIDGE CROSSING THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. NORTH APPROACH TO SE 14TH STREET BRIDGE CROSSING THE DES MOINES RIVER, LOOKING SOUTH. - Southeast Fourteenth Street Bridge, Spanning Des Moines River at U.S. Highway 65/69, Des Moines, Polk County, IA

  12. Optimal cross-sectional sampling for river modelling with bridges: An information theory-based method

    NASA Astrophysics Data System (ADS)

    Ridolfi, E.; Alfonso, L.; Di Baldassarre, G.; Napolitano, F.

    2016-06-01

    The description of river topography has a crucial role in accurate one-dimensional (1D) hydraulic modelling. Specifically, cross-sectional data define the riverbed elevation, the flood-prone area, and thus, the hydraulic behavior of the river. Here, the problem of the optimal cross-sectional spacing is solved through an information theory-based concept. The optimal subset of locations is the one with the maximum information content and the minimum amount of redundancy. The original contribution is the introduction of a methodology to sample river cross sections in the presence of bridges. The approach is tested on the Grosseto River (IT) and is compared to existing guidelines. The results show that the information theory-based approach can support traditional methods to estimate rivers' cross-sectional spacing.

  13. Propylene cross-bridged macrocyclic bifunctional chelator: a new design for facile bioconjugation and robust (64)Cu complex stability.

    PubMed

    Pandya, Darpan N; Bhatt, Nikunj; An, Gwang Il; Ha, Yeong Su; Soni, Nisarg; Lee, Hochun; Lee, Yong Jin; Kim, Jung Young; Lee, Woonghee; Ahn, Heesu; Yoo, Jeongsoo

    2014-09-11

    The first macrocyclic bifunctional chelator incorporating propylene cross-bridge was efficiently synthesized from cyclam in seven steps. After the introduction of an extra functional group for facile conjugation onto the propylene cross-bridge, the two carboxylic acid pendants could contribute to strong coordination of Cu(II) ions, leading to a robust Cu complex. The cyclic RGD peptide conjugate of PCB-TE2A-NCS was prepared and successfully radiolabeled with (64)Cu ion. The radiolabeled peptide conjugate was evaluated in vivo through a biodistribution study and animal PET imaging to demonstrate high tumor uptake with low background. PMID:25137619

  14. Contributions of diesel truck emissions to indoor elemental carbon concentrations in homes in proximity to Ambassador Bridge

    NASA Astrophysics Data System (ADS)

    Baxter, Lisa K.; Barzyk, Timothy M.; Vette, Alan F.; Croghan, Carry; Williams, Ronald W.

    Ambassador Bridge, connecting Detroit, Michigan and Windsor, Ontario, is the busiest international commercial vehicle crossing in North America, with a large percentage of heavy duty diesel trucks. This study seeks to examine the contribution of diesel truck traffic across Ambassador Bridge to indoor exposure patterns of elemental carbon (EC), a common surrogate for diesel exhaust particles, in homes in close proximity to the bridge. We also aim to understand the relative importance of home ventilation characteristics and wind speed. Measurements were collected as part of the Detroit Exposure and Aerosol Research Study (DEARS). Residential indoor and outdoor EC measurements were collected over five consecutive 24 h periods in both the summer and winter at 16 homes in close proximity to Ambassador Bridge. Ambient concentrations and meteorological data were collected at a central-site monitor, and home air exchange rates were estimated using a perfluorocarbon tracer. The contributions of ambient concentrations and Ambassador Bridge, and potential effect modification by wind speed and home ventilation status were quantified with regression analyses. Both ambient concentrations and the percentage of time a home was downwind from the bridge were associated with an increase in indoor concentrations. Ambient concentrations significantly contributed to indoor concentrations regardless of wind speed category but were a greater influence in home experiencing calm winds. The effect of the percent of time downwind variable on indoor levels was only significant in homes where the ventilation status was high. The distance a home was from the bridge tollbooth complex was not significantly associated with indoor concentrations. We conclude that diesel traffic emissions related to Ambassador Bridge may have an impact on indoor EC exposures. Given that people spend the majority of their time indoors, it is important to evaluate the impact of traffic-related pollution in the home

  15. The cross-bridge spring: can cool muscles store elastic energy?

    PubMed

    George, N T; Irving, T C; Williams, C D; Daniel, T L

    2013-06-01

    Muscles not only generate force. They may act as springs, providing energy storage to drive locomotion. Although extensible myofilaments are implicated as sites of energy storage, we show that intramuscular temperature gradients may enable molecular motors (cross-bridges) to store elastic strain energy. By using time-resolved small-angle x-ray diffraction paired with in situ measurements of mechanical energy exchange in flight muscles of Manduca sexta, we produced high-speed movies of x-ray equatorial reflections, indicating cross-bridge association with myofilaments. A temperature gradient within the flight muscle leads to lower cross-bridge cycling in the cooler regions. Those cross-bridges could elastically return energy at the extrema of muscle lengthening and shortening, helping drive cyclic wing motions. These results suggest that cross-bridges can perform functions other than contraction, acting as molecular links for elastic energy storage. PMID:23618763

  16. CONTRIBUTION FROM DEICING SALT TO CHEMICAL COMPOSITION OF SALT SUPPLYED TO AREA UNDER THE BRIDGES

    NASA Astrophysics Data System (ADS)

    Takebe, Masamichi; Ohya, Makoto; Hirose, Nozomu; Ochibe, Keishi; Aso, Toshihiko

    Salt is known to accelerate the corrosion of weathering steel bridges. The origin of salt around girders is valuable information in terms of the maintenance for anti-corrosion of steel bridges. Salt around girders generally originates from sea-salt and deicing salt. Since salt of both origin increases in winter, contribution of deicing salt is hard to be estimated only from fluctuation of total abundance of salt around the bridge. In this study, abundance of Mg2+ as well as that of Cl- in salt sampled under bridges is analyzed. As a result, this study revealed that the supply of deicing salt declines Mg2+/Cl- ratio of salt on the girder. In addition, examination of Mg2+/Cl- ratio of salt sampled under the examined bridge near sea revealed that the fluctuation of quantity of air-born salt under the bridge is ascribed to the fluctuation of supply of sea salt.

  17. Two Salt Bridges Differentially Contribute to the Maintenance of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Channel Function*

    PubMed Central

    Cui, Guiying; Freeman, Cody S.; Knotts, Taylor; Prince, Chengyu Z.; Kuang, Christopher; McCarty, Nael A.

    2013-01-01

    Previous studies have identified two salt bridges in human CFTR chloride ion channels, Arg352-Asp993 and Arg347-Asp924, that are required for normal channel function. In the present study, we determined how the two salt bridges cooperate to maintain the open pore architecture of CFTR. Our data suggest that Arg347 not only interacts with Asp924 but also interacts with Asp993. The tripartite interaction Arg347-Asp924-Asp993 mainly contributes to maintaining a stable s2 open subconductance state. The Arg352-Asp993 salt bridge, in contrast, is involved in stabilizing both the s2 and full (f) open conductance states, with the main contribution being to the f state. The s1 subconductance state does not require either salt bridge. In confirmation of the role of Arg352 and Asp993, channels bearing cysteines at these sites could be latched into a full open state using the bifunctional cross-linker 1,2-ethanediyl bismethanethiosulfonate, but only when applied in the open state. Channels remained latched open even after washout of ATP. The results suggest that these interacting residues contribute differently to stabilizing the open pore in different phases of the gating cycle. PMID:23709221

  18. Two salt bridges differentially contribute to the maintenance of cystic fibrosis transmembrane conductance regulator (CFTR) channel function.

    PubMed

    Cui, Guiying; Freeman, Cody S; Knotts, Taylor; Prince, Chengyu Z; Kuang, Christopher; McCarty, Nael A

    2013-07-12

    Previous studies have identified two salt bridges in human CFTR chloride ion channels, Arg(352)-Asp(993) and Arg(347)-Asp(924), that are required for normal channel function. In the present study, we determined how the two salt bridges cooperate to maintain the open pore architecture of CFTR. Our data suggest that Arg(347) not only interacts with Asp(924) but also interacts with Asp(993). The tripartite interaction Arg(347)-Asp(924)-Asp(993) mainly contributes to maintaining a stable s2 open subconductance state. The Arg(352)-Asp(993) salt bridge, in contrast, is involved in stabilizing both the s2 and full (f) open conductance states, with the main contribution being to the f state. The s1 subconductance state does not require either salt bridge. In confirmation of the role of Arg(352) and Asp(993), channels bearing cysteines at these sites could be latched into a full open state using the bifunctional cross-linker 1,2-ethanediyl bismethanethiosulfonate, but only when applied in the open state. Channels remained latched open even after washout of ATP. The results suggest that these interacting residues contribute differently to stabilizing the open pore in different phases of the gating cycle. PMID:23709221

  19. Comb/serpentine/cross-bridge test structure for fabrication process evaluation

    NASA Technical Reports Server (NTRS)

    Sayah, Hoshyar R.; Buehler, Martin G.

    1988-01-01

    The comb/serpentine/cross-bridge structure was developed to monitor and evaluate same layer shorts and step coverage problems (open and high-resistance wire over steps) for integrated circuit fabrication processes. The cross-bridge provides local measurements of wire sheet resistance and wirewidth. These local parametric measurements are used in the analysis of the serpentine wire, which identifies step coverage problems. The comb/serpentine/cross-bridge structure was fabricated with 3 microns CMOS/bulk p-well process and tested using a computer-controlled parametric test system.

  20. High ionic strength depresses muscle contractility by decreasing both force per cross-bridge and the number of strongly attached cross-bridges.

    PubMed

    Wang, Li; Bahadir, Anzel; Kawai, Masataka

    2015-06-01

    An increase in ionic strength (IS) lowers Ca(2+) activated tension in muscle fibres, however, its molecular mechanism is not well understood. In this study, we used single rabbit psoas fibres to perform sinusoidal analyses. During Ca(2+) activation, the effects of ligands (ATP, Pi, and ADP) at IS ranging 150-300 mM were studied on three rate constants to characterize elementary steps of the cross-bridge cycle. The IS effects were studied because a change in IS modifies the inter- and intra-molecular interactions, hence they may shed light on the molecular mechanisms of force generation. Both the ATP binding affinity (K1) and the ADP binding affinity (K 0) increased to 2-3x, and the Pi binding affinity (K5) decreased to 1/2, when IS was raised from 150 to 300 mM. The effect on ATP/ADP can be explained by stereospecific and hydrophobic interaction, and the effect on Pi can be explained by the electrostatic interaction with myosin. The increase in IS increased cross-bridge detachment steps (k2 and k-4), indicating that electrostatic repulsion promotes these steps. However, IS did not affect attachment steps (k-2 and k4). Consequently, the equilibrium constant of the detachment step (K2) increased by ~100%, and the force generation step (K4) decreased by ~30%. These effects together diminished the number of force-generating cross-bridges by 11%. Force/cross-bridge (T56) decreased by 26%, which correlates well with a decrease in the Debye length that limits the ionic atmosphere where ionic interactions take place. We conclude that the major effect of IS is a decrease in force/cross-bridge, but a decrease in the number of force generating cross-bridge also takes place. The stiffness during rigor induction did not change with IS, demonstrating that in-series compliance is not much affected by IS. PMID:25836331

  1. Crossing Bridges That Connect the Arts, Cognitive Development, and the Brain

    ERIC Educational Resources Information Center

    Peterson, Rita

    2005-01-01

    Crossing high bridges offers the opportunity to ponder views from a distance: to see connections between places at the ground level or ideas that are familiar, and to capture an overview of places or ideas that are yet to be explored. The purpose of this essay is to explore the figural bridges that connect the arts with cognitive development and…

  2. 13. I95 bridge crossing corridor with Providence Station in background. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. I-95 bridge crossing corridor with Providence Station in background. Providence, Providence County, RI. sec. 4116, mp 185.15. - Northeast Railroad Corridor, Amtrak route between CT & MA state lines, Providence, Providence County, RI

  3. Bridge No. 1363, First B&O Crossing, detail of skewed through ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bridge No. 1363, First B&O Crossing, detail of skewed through truss, looking west. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  4. Skewed west portal of Bridge No. 1363, First B&O Crossing, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Skewed west portal of Bridge No. 1363, First B&O Crossing, looking east. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  5. Nonlinear Cross-Bridge Elasticity and Post-Power-Stroke Events in Fast Skeletal Muscle Actomyosin

    PubMed Central

    Persson, Malin; Bengtsson, Elina; ten Siethoff, Lasse; Månsson, Alf

    2013-01-01

    Generation of force and movement by actomyosin cross-bridges is the molecular basis of muscle contraction, but generally accepted ideas about cross-bridge properties have recently been questioned. Of the utmost significance, evidence for nonlinear cross-bridge elasticity has been presented. We here investigate how this and other newly discovered or postulated phenomena would modify cross-bridge operation, with focus on post-power-stroke events. First, as an experimental basis, we present evidence for a hyperbolic [MgATP]-velocity relationship of heavy-meromyosin-propelled actin filaments in the in vitro motility assay using fast rabbit skeletal muscle myosin (28–29°C). As the hyperbolic [MgATP]-velocity relationship was not consistent with interhead cooperativity, we developed a cross-bridge model with independent myosin heads and strain-dependent interstate transition rates. The model, implemented with inclusion of MgATP-independent detachment from the rigor state, as suggested by previous single-molecule mechanics experiments, accounts well for the [MgATP]-velocity relationship if nonlinear cross-bridge elasticity is assumed, but not if linear cross-bridge elasticity is assumed. In addition, a better fit is obtained with load-independent than with load-dependent MgATP-induced detachment rate. We discuss our results in relation to previous data showing a nonhyperbolic [MgATP]-velocity relationship when actin filaments are propelled by myosin subfragment 1 or full-length myosin. We also consider the implications of our results for characterization of the cross-bridge elasticity in the filament lattice of muscle. PMID:24138863

  6. Probing cross-bridge angular transitions using multiple extrinsic reporter groups

    SciTech Connect

    Ajtai, K.; Ringler, A.; Burghardt, T.P. )

    1992-01-14

    {sup 15}N- and {sup 2}H-substituted maleimido- TEMPO spin label (({sup 15}N, {sup 2}H)MTSL) and the fluorescent label 1,5-IAEDANS were used to specifically modify sulfhydryl 1 of myosin to study the orientation of myosin cross-bridges in skeletal muscle fibers. The electron paramagnetic resonance (EPR) spectrum from muscle fibers decorated with labeled myosin subfragment 1 (({sup 15}N, {sup 2}H)MTSL-S1) or the fluorescence polarization spectrum from fibers directly labeled with 1,5-IAEDANS was measured from fibers in various physiological conditions. The EPR spectra from fibers with the fiber axis oriented at 90{degree} to the Zeeman field show a clear spectral shift from the rigor spectrum when the myosin cross-bridge binds MgADP. The EPR data from ({sup 15}N,{sup 2}H)MTSL-S1 decorating fibers are combined with the fluorescence polarization data from the 1,5-IAEDANS-labeled fibers to map the global angular transition of the labeled cross-bridges due to nucleotide binding by an analytical method described in the accompanying paper. The authors find that the spin and fluorescent probes are quantitatively consistent in the finding that the actin-bound cross-bridge rotates through a large angle upon binding MgADP. They also find that, if the shape of the cross-bridge is described as an ellipsoid with two equivalent minor axes, then cross-bridge rotation takes place mainly about an axis parallel to the major axis of the ellipsoid. This type of rotation may imitate the rotational motion of cross-bridges during force generation.

  7. Thick-to-Thin Filament Surface Distance Modulates Cross-Bridge Kinetics in Drosophila Flight Muscle

    SciTech Connect

    Tanner, Bertrand C.W.; Farman, Gerrie P.; Irving, Thomas C.; Maughan, David W.; Palmer, Bradley M.; Miller, Mark S.

    2012-09-19

    The demembranated (skinned) muscle fiber preparation is widely used to investigate muscle contraction because the intracellular ionic conditions can be precisely controlled. However, plasma membrane removal results in a loss of osmotic regulation, causing abnormal hydration of the myofilament lattice and its proteins. We investigated the structural and functional consequences of varied myofilament lattice spacing and protein hydration on cross-bridge rates of force development and detachment in Drosophila melanogaster indirect flight muscle, using x-ray diffraction to compare the lattice spacing of dissected, osmotically compressed skinned fibers to native muscle fibers in living flies. Osmolytes of different sizes and exclusion properties (Dextran T-500 and T-10) were used to differentially alter lattice spacing and protein hydration. At in vivo lattice spacing, cross-bridge attachment time (t{sub on}) increased with higher osmotic pressures, consistent with a reduced cross-bridge detachment rate as myofilament protein hydration decreased. In contrast, in the swollen lattice, t{sub on} decreased with higher osmotic pressures. These divergent responses were reconciled using a structural model that predicts t{sub on} varies inversely with thick-to-thin filament surface distance, suggesting that cross-bridge rates of force development and detachment are modulated more by myofilament lattice geometry than protein hydration. Generalizing these findings, our results suggest that cross-bridge cycling rates slow as thick-to-thin filament surface distance decreases with sarcomere lengthening, and likewise, cross-bridge cycling rates increase during sarcomere shortening. Together, these structural changes may provide a mechanism for altering cross-bridge performance throughout a contraction-relaxation cycle.

  8. Bridge No. 1396, Fourth Potomac and Second B&O Crossing, with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bridge No. 1396, Fourth Potomac and Second B&O Crossing, with B&O Potomac Crossing (built ca. 1914 as part of B&O's Magnolia Cutoff) in background, looking east. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  9. High Ionic Strength Depresses Muscle Contractility by Decreasing both Force per Cross-bridge and the Number of Strongly Attached Cross-bridges

    PubMed Central

    Wang, Li; Bahadir, Anzel; Kawai, Masataka

    2015-01-01

    An increase in ionic strength (IS) lowers Ca2+ activated tension in muscle fibres, however, its molecular mechanism is not well understood. In this study, we used single rabbit psoas fibres to perform sinusoidal analyses. During Ca2+ activation, the effects of ligands (ATP, Pi, and ADP) at IS ranging 150 mM – 300 mM were studied on three rate constants to characterize elementary steps of the cross-bridge cycle. The IS effects were studied because a change in IS modifies the inter- and intra-molecular interactions, hence they may shed light on the molecular mechanisms of force generation. Both the ATP binding affinity (K1) and the ADP binding affinity (K0) increased to 2-3x, and the Pi binding affinity (K5) decreased to 1/2, when IS was raised from 150 mM to 300 mM. The effect on ATP/ADP can be explained by stereospecific and hydrophobic interaction, and the effect on Pi can be explained by the electrostatic interaction with myosin. The increase in IS increased cross-bridge detachment steps (k2 and k−4), indicating that electrostatic repulsion promotes these steps. However, IS did not affect attachment steps (k−2 and k4). Consequently, the equilibrium constant of the detachment step (K2) increased by ~100%, and the force generation step (K4) decreased by ~30%. These effects together diminished the number of force-generating cross-bridges by 11%. Force/cross-bridge (T56) decreased by 26%, which correlates well with a decrease in the Debye length that limits the ionic atmosphere where ionic interactions take place. We conclude that the major effect of IS is a decrease in force/cross-bridge, but a decrease in the number of force generating cross-bridge also takes place. The stiffness during rigor induction did not change with IS, demonstrating that in-series compliance is not much affected by IS. PMID:25836331

  10. Cross-Bridge Group Ensembles Describing Cooperativity in Thermodynamically Consistent Way

    PubMed Central

    Kalda, Mari; Peterson, Pearu; Vendelin, Marko

    2015-01-01

    The aim of this work is to incorporate cooperativity into Huxley-type cross-bridge model in thermodynamically consistent way. While the Huxley-type models assume that cross-bridges act independently from each other, we take into account that each cross-bridge is influenced by its neighbors and cooperativity is induced by tropomyosin movement. For that, we introduce ensembles of cross-bridge groups connected by elastic tropomyosin. By taking into account that the mechanical displacement of tropomyosin induces free energy change of the cross-bridge group ensemble, we develop the formalism for thermodynamically consistent description of the cooperativity in muscle contraction. An example model was composed to test the approach. The model parameters were found by optimization from the linear relation between oxygen consumption and stress-strain area as well as experimentally measured stress dynamics of rat trabecula. We have found a good agreement between the optimized model solution and experimental data. Simulations also showed that it is possible to study cooperativity with the approach developed in this work. PMID:26361396

  11. Observing cycling of a few cross-bridges during isometric contraction of skeletal muscle

    PubMed Central

    Mettikolla, P.; Calander, N.; Luchowski, R.; Gryczynski, I.; Gryczynski, Z.; Borejdo, J.

    2010-01-01

    During muscle contraction a myosin cross-bridge imparts periodic force impulses to actin. It is possible to visualize those impulses by observing a few molecules of actin or myosin. We have followed the time course of orientation change of a few actin molecules during isometric contraction by measuring parallel polarized intensity of its fluorescence. The orientation of actin reflects local bending of a thin filament and is different when a cross-bridge binds to, or is detached from, F-actin. The changes in orientation were characterized by periods of activity during which myosin cross-bridges interacted normally with actin, interspersed with periods of inactivity during which actin and myosin were unable to interact. The periods of activity lasted on average 1.2 ± 0.4 s and were separated on average by 2.3 ± 1.0 s. During active period, actin orientation oscillated between the two extreme values with the ON and OFF times of 0.4±0.2 and 0.7±0.4 s, respectively. When the contraction was induced by a low concentration of ATP both active and inactive times were longer and approximately equal. These results imply that cross-bridges interact with actin in bursts and suggest that during active period, on average 36% of cross-bridges are involved in force generation. PMID:20517927

  12. Time-resolved measurements of phosphate release by cycling cross-bridges in portal vein smooth muscle.

    PubMed

    He, Z H; Ferenczi, M A; Brune, M; Trentham, D R; Webb, M R; Somlyo, A P; Somlyo, A V

    1998-12-01

    The rate of release of inorganic phosphate (Pi) from cycling cross-bridges in rabbit portal-anterior mesenteric vein smooth muscle was determined by following the fluorescence of the Pi-reporter, MDCC-PBP (Brune, M., J. L. Hunter, S. A. Howell, S. R. Martin, T. L. Hazlett, J. E. T. Corrie, and M. R. Webb. 1998. Biochemistry. 37:10370-10380). Cross-bridge cycling was initiated by photolytic release of ATP from caged-ATP in Triton-permeabilized smooth muscles in rigor. When the regulatory myosin light chains (MLC20) had been thiophosphorylated, the rate of Pi release was biphasic with an initial rate of 80 microM s-1 and amplitude 108 microM, decreasing to 13.7 microM s-1. These rates correspond to fast and slow turnovers of 1.8 s-1 and 0.3 s-1, assuming 84% thiophosphorylation of 52 microM myosin heads. Activation by Ca2+-dependent phosphorylation subsequent to ATP release resulted in slower Pi release, paralleling the rate of contraction that was also slower than after thiophosphorylation, and was also biphasic: 51 microM s-1 and 13.2 microM s-1. These rates suggest that the activity of myosin light chain kinase and phosphatase ("pseudo-ATPase") contributes <20% of the ATP usage during cross-bridge cycling. The extracellular "ecto-nucleotidase" activity was reduced eightfold by permeabilization, conditions in which the ecto-ADPase was 17% of the ecto-ATPase. Nevertheless, the remaining ecto-ATPase activity reduced the precision of the estimate of cross-bridge ATPase. We conclude that the transition from fast to slow ATPase rates reflects the properties and forces directly acting on cross-bridges, rather than the result of a time-dependent decrease in activation (MLC20 phosphorylation) occurring in intact smooth muscle. The mechanisms of slowing may include the effect of positive strain on cross-bridges, inhibition of the cycling rate by high affinity Mg-ADP binding, and associated state hydrolysis. PMID:9826623

  13. Cross-spectral recognition method of bridge deck aerodynamic admittance function

    NASA Astrophysics Data System (ADS)

    Zhao, Lin; Ge, Yaojun

    2015-12-01

    This study proposes a new identification algorithm about the admittance function, which can estimate the full set of six aerodynamic admittance functions considering cross power spectral density functions about the forces and the turbulence components. The method was first numerically validated through Monte Carlo simulations, and then adopted to estimate the aerodynamic admittance of a streamlined bridge deck. The identification method was further validated through a comparison between the numerical calculation and wind tunnel tests on a moving bridge section.

  14. Backwater and discharge at highway crossings with multiple bridges in Louisiana and Mississippi

    USGS Publications Warehouse

    Colson, B.E.; Schneider, V.R.

    1983-01-01

    Data were collected for nine floods in Mississippi and Louisiana at eight stream crossings having two to six separate bridge openings. Discharge through each bridge, water surface profiles, valley cross sections, and bridge geometry were measured. The multiple openings were divided into equivalent single-opening cases by apportioning interior embankments in direct proportion to the area of openings on either side. Using existing procedures for computer discharge, the bias in computed discharge was 2 percent with a root mean square error of 18 percent. Backwater was computed by two current U.S. Geological Survey methods that use the average flow path in the friction loss term for the approach. One method gave a root mean square error of 0.34 ft. with a bias of -0.25 ft., suggesting that the method underestimates backwater. The other method gave a root mean square error of 0.39 ft with a bias of -0.03 ft. The results indicate that the method developed for single-opening highway crossings can be applied to the multiple bridge crossings. (USGS)

  15. Crossing the Water: Spiritual Growth in "Bridge to Terabithia" and "Lizzie Bright and the Buckminster Boy"

    ERIC Educational Resources Information Center

    Thomas, Trudelle

    2011-01-01

    The author analyses two award-winning juvenile novels, "Bridge to Terabithia" by Katherine Paterson and "Lizzie Bright and the Buckminster Boy" by Gary Schmidt. Each novel portrays a deep friendship between a boy and girl who cross a stream (or river) into a world that includes fantasy, play, closeness to nature and animals, and a sense of the…

  16. Bridge No. 1628, Sixth C&O Canal Crossing, looking northeast, with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bridge No. 1628, Sixth C&O Canal Crossing, looking northeast, with corner of Roberts and Candoc streets in South Cumberland, Maryland, in background. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  17. Force generation and work production by covalently cross-linked actin-myosin cross-bridges in rabbit muscle fibers.

    PubMed

    Bershitsky, S Y; Tsaturyan, A K

    1995-09-01

    To separate a fraction of the myosin cross-bridges that are attached to the thin filaments and that participate in the mechanical responses, muscle fibers were cross-linked with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and then immersed in high-salt relaxing solution (HSRS) of 0.6 M ionic strength for detaching the unlinked myosin heads. The mechanical properties and force-generating ability of the cross-linked cross-bridges were tested with step length changes (L-steps) and temperature jumps (T-jumps) from 6-10 degrees C to 30-40 degrees C. After partial cross-linking, when instantaneous stiffness in HSRS was 25-40% of that in rigor, the mechanical behavior of the fibers was similar to that during active contraction. The kinetics of the T-jump-induced tension transients as well as the rate of the fast phase of tension recovery after length steps were close to those in unlinked fibers during activation. Under feedback force control, the T-jump initiated fiber shortening by up to 4 nm/half-sarcomere. Work produced by a cross-linked myosin head after the T-jump was up to 30 x 10(-21) J. When the extent of cross-linking was increased and fiber stiffness in HSRS approached that in rigor, the fibers lost their viscoelastic properties and ability to generate force with a rise in temperature. PMID:8519956

  18. Helix-coil melting in rigor and activated cross-bridges of skeletal muscle.

    PubMed

    Harrington, W F; Ueno, H; Davis, J S

    1988-01-01

    The studies described in this paper focus on the structural stability of the S-2 segment of the myosin cross-bridge in rigor, relaxed and activated muscle. Enzyme-probe observations of myofibrils of rabbit psoas muscle in rigor reveal that the alpha-helical LMM/HMM hinge domain of S-2 undergoes substantial local melting near physiological temperatures when the S-2 portion of the cross-bridge is detached from the thick filament surface. This process is strongly suppressed under ionic conditions where the cross-bridge is bound to the filament backbone. Activation of glycerinated fiber bundles results in a dramatic increase (approximately 100 fold compared to rigor and relaxed fibers) in the rate of chymotryptic cleavage in the hinge domain consistent with an increase in local melting at several sites encompassing this region. Comparative plots of the apparent rate-constant for cleavage within the S-2 hinge and the isometric force generated by active fibers versus [MgATP] give similar profiles suggesting a close coupling between this conformational transition and contractile force. This interpretation appears to be in accord with recent laser T-jump experiments of rigor ("bridges up") and activated psoas muscle fibers which also suggest coupling between melting in S-2 and force generation. PMID:3044019

  19. Contribution of Disulfide Bridges to the Thermostability of a Type A Feruloyl Esterase from Aspergillus usamii

    PubMed Central

    Li, Jian-Fang; He, Yao; Zhu, Tian-Di; Wu, Min-Chen

    2015-01-01

    The contribution of disulfide bridges to the thermostability of a type A feruloyl esterase (AuFaeA) from Aspergillus usamii E001 was studied by introducing an extra disulfide bridge or eliminating a native one from the enzyme. MODIP and DbD, two computational tools that can predict the possible disulfide bridges in proteins for thermostability improvement, and molecular dynamics (MD) simulations were used to design the extra disulfide bridge. One residue pair A126-N152 was chosen, and the respective amino acid residues were mutated to cysteine. The wild-type AuFaeA and its variants were expressed in Pichia pastoris GS115. The temperature optimum of the recombinant (re-) AuFaeAA126C-N152C was increased by 6°C compared to that of re-AuFaeA. The thermal inactivation half-lives of re-AuFaeAA126C-N152C at 55 and 60°C were 188 and 40 min, which were 12.5- and 10-folds longer than those of re-AuFaeA. The catalytic efficiency (kcat/Km) of re-AuFaeAA126C-N152C was similar to that of re-AuFaeA. Additionally, after elimination of each native disulfide bridge in AuFaeA, a great decrease in expression level and at least 10°C decrease in thermal stability of recombinant AuEaeA variants were also observed. PMID:25969986

  20. Measurement of bridge scour at the SR-32 crossing of the Sacramento River at Hamilton City, California, 1987-92

    USGS Publications Warehouse

    Blodgett, J.C.; Harris, Carroll D.

    1993-01-01

    A study of the State Route 32 crossing of the Sacramento River near Hamilton City, California, is being made to determine those channel and bridge factors that contribute to scour at the site. Three types of scour data have been measured-channel bed (natural) scour, constriction (general) scour, and local (bridge-pier induced) scour. During the years 1979-93, a maximum of 3.4 ft of channel bed scour, with a mean of 1.4 ft, has been measured. Constriction scour, which may include channel bed scour, has been measured at the site nine times during the years 1987-92. The calculated amount of constriction scour ranged from 0.2 to 3.0 ft, assuming the reference is the mean bed elevation. Local scour was measured four times at the site in 1991 and 1992 and ranged from -2.1 (fill) to 11.6 ft , with the calculated amounts dependent on the bed reference elevation and method of computation used. Surveys of the channel bed near the bridge piers indicate the horizontal location of lowest bed elevation (maximum depth of scour) may vary at least 17 ft between different surveys at the same pier and most frequently is located downstream from the upstream face of the pier.

  1. Cross-bridged Macrocyclic Chelators for Stable Complexation of Copper Radionuclides for PET Imaging

    PubMed Central

    Anderson, Carolyn J.; Wadas, Thaddeus J.; Wong, Edward H.; Weisman, Gary R.

    2015-01-01

    Copper-64 (t1/2 = 12.7 h, β+: 17.4%, Eβ+max = 656 keV; β−: 39%, Eβ-max = 573 keV) has emerged as an important non-standard positron-emitting radionuclide for PET imaging of diseased tissues. A significant challenge of working with copper radionuclides is that they must be delivered to the living system as a stable complex that is attached to a biological targeting molecule for effective imaging and therapy. Significant research has been devoted to the development of ligands that can stably chelate 64Cu, in particular, the cross-bridged macrocyclic chelators. This review describes the coordination chemistry and biological behavior of 64Cu-labeled cross-bridged complexes. PMID:18043536

  2. Rad54 oligomers translocate and cross-bridge double-stranded DNA to stimulate synapsis

    PubMed Central

    Bianco, Piero R.; Bradfield, Justin J.; Castanza, Lauren R.; Donnelly, Andrea N.

    2007-01-01

    Rad54 is a key component of the eukaryotic recombination machinery. Its presence in DNA strand exchange reactions in vitro results in a significant stimulation in the overall reaction rate. Using untagged Rad54, we show that this stimulation can be attributed to enhancement of the formation of a key reaction intermediate known as DNA networks. Using a novel, single DNA molecule, dual-optical tweezers approach we show how Rad54 stimulates DNA network formation. We discovered that Rad54 oligomers possess a unique ability to cross-bridge or bind dsDNA molecules positioned in close proximity. Further, Rad54 oligomers rapidly translocate dsDNA while simultaneously inducing topological loops in the DNA at the locus of the oligomer. The combination of the cross-bridging and dsDNA translocation activities of Rad54 stimulates the formation of DNA networks, leading to rapid and efficient DNA strand exchange by Rad51. PMID:17949748

  3. Regulation of muscle force in the absence of actin-myosin-based cross-bridge interaction.

    PubMed

    Leonard, T R; Herzog, W

    2010-07-01

    For the past half century, the sliding filament-based cross-bridge theory has been the cornerstone of our understanding of how muscles contract. According to this theory, active force can only occur if there is overlap between the contractile filaments, actin and myosin. Otherwise, forces are thought to be caused by passive structural elements and are assumed to vary solely because of the length of the muscle. We observed increases in muscle force by a factor of 3 to 4 above the purely passive forces for activated and stretched myofibrils in the absence of actin-myosin overlap. We show that this dramatic increase in force is crucially dependent on the presence of the structural protein titin, cannot be explained with calcium activation, and is regulated by actin-myosin-based cross-bridge forces before stretching. We conclude from these observations that titin is a strong regulator of muscle force and propose that this regulation is based on cross-bridge force-dependent titin-actin interactions. These results suggest a mechanism for stability of sarcomeres on the "inherently unstable" descending limb of the force-length relationship, and they further provide an explanation for the protection of muscles against stretch-induced muscle injuries. PMID:20357181

  4. Synthesis of a Cross-Bridged Cyclam Derivative for Peptide Conjugation and 64Cu Radiolabeling

    PubMed Central

    Boswell, C. Andrew; Regino, Celeste A. S.; Baidoo, Kwamena E.; Wong, Karen J.; Bumb, Ambika; Xu, Heng; Milenic, Diane E.; Kelley, James A.; Lai, Christopher C.; Brechbiel, Martin W.

    2008-01-01

    The increased use of copper radioisotopes in radiopharmaceutical applications has created a need for bifunctional chelators (BFCs) that form stable radiocopper complexes and allow covalent attachment to biological molecules. Previous studies have established that 4,11-bis-(carbo-tert-butoxymethyl)-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane (H2CB-TE2A), a member of the ethylene “cross-bridged” cyclam (CB-cyclam) class of bicyclic tetraaza macrocycles, forms highly kinetically stable complexes with Cu(II) and is less susceptible to in vivo transchelation than its non-bridged analog, 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid (TETA). Herein, we report a convenient synthesis of a novel cross-bridged BFC that is structurally analogous to CB-TE2A in that it possesses two coordinating acetate arms, but in addition possesses a third orthogonally-protected arm for conjugation to peptides and other targeting agents. Application of this strategy to cross-bridged chelators may also enable the development of even further improved agents for 64Cu-mediated diagnostic positron emission tomography (PET) imaging as well as for targeted radiotherapeutic applications. PMID:18597510

  5. Kinetic and thermodynamic studies of the cross-bridge cycle in rabbit psoas muscle fibers.

    PubMed Central

    Zhao, Y; Kawai, M

    1994-01-01

    The effect of temperature on elementary steps of the cross-bridge cycle was investigated with sinusoidal analysis technique in skinned rabbit psoas fibers. We studied the effect of MgATP on exponential process (C) to characterize the MgATP binding step and cross-bridge detachment step at six different temperatures in the range 5-30 degrees C. Similarly, we studied the effect of MgADP on exponential process (C) to characterize the MgADP binding step. We also studied the effect of phosphate (Pi) on exponential process (B) to characterize the force generation step and Pi-release step. From the results of these studies, we deduced the temperature dependence of the kinetic constants of the elementary steps and their thermodynamic properties. We found that the MgADP association constant (K0) and the MgATP association constant (K1) significantly decreased when the temperature was increased from 5 to 20 degrees C, implying that nucleotide binding became weaker at higher temperatures. K0 and K1 did not change much in the 20-30 degree C range. The association constant of Pi to cross-bridges (K5) did not change much with temperature. We found that Q10 for the cross-bridge detachment step (k2) was 2.6, and for its reversal step (k-2) was 3.0. We found that Q10 for the force generation step (Pi-isomerization step, k4) was 6.8, and its reversal step (k-4) was 1.6. The equilibrium constant of the detachment step (K2) was not affected much by temperature, whereas the equilibrium constant of the force generation step (K4) increased significantly with temperature increase. Thus, the force generation step consists of an endothermic reaction. The rate constant of the rate-limiting step (k6) did not change much with temperature, whereas the ATP hydrolysis rate increased significantly with temperature increase. We found that the force generation step accompanies a large entropy increase and a small free energy change; hence, this step is an entropy-driven reaction. These observations

  6. Split-cross-bridge resistor for testing for proper fabrication of integrated circuits

    NASA Technical Reports Server (NTRS)

    Buehler, M. G. (Inventor)

    1985-01-01

    An electrical testing structure and method is described whereby a test structure is fabricated on a large scale integrated circuit wafer along with the circuit components and has a van der Pauw cross resistor in conjunction with a bridge resistor and a split bridge resistor, the latter having two channels each a line width wide, corresponding to the line width of the wafer circuit components, and with the two channels separated by a space equal to the line spacing of the wafer circuit components. The testing structure has associated voltage and current contact pads arranged in a two by four array for conveniently passing currents through the test structure and measuring voltages at appropriate points to calculate the sheet resistance, line width, line spacing, and line pitch of the circuit components on the wafer electrically.

  7. Carbodiimide cross-linking of amniotic membranes in the presence of amino acid bridges.

    PubMed

    Lai, Jui-Yang

    2015-06-01

    The purpose of this study was to investigate the carbodiimide cross-linking of amniotic membrane (AM) in the presence of amino acid bridges. The biological tissues were treated with glycine, lysine, or glutamic acid and chemically cross-linked to examine the role of amino acid types in collagenous biomaterial processing. Results of zeta potential measurements showed that the use of uncharged, positively and negatively charged amino acids dictates the charge state of membrane surface. Tensile strength and water content measurements demonstrated that the addition of lysine molecules to the cross-linking system can increase the cross-linking efficiency and dehydration degree while the introduction of glutamic acid in the AM samples decreases the number of cross-links per unit mass of chemically modified tissue collagen. The differences in the cross-linking density further determined the thermal and biological stability by differential scanning calorimetry and in vitro degradation tests. As demonstrated in matrix permeability studies, the improved formation of covalent cross-linkages imposed by lysine facilitated construction of stronger cross-linking structures. In contrast, the added glycine molecules were insufficient to enhance the resistances of the proteinaceous matrices to thermal denaturation and enzymatic degradation. The cytocompatibility of these biological tissue membranes was evaluated by using human corneal epithelial cell cultures. Results of cell viability, metabolic activity, and pro-inflammatory gene expression level showed that the AM materials cross-linked with carbodiimide in the presence of different types of amino acids are well tolerated without evidence of detrimental effect on cell growth. In addition, the amino acid treated and carbodiimide cross-linked AM implants had good biocompatibility in the anterior chamber of the rabbit eye model. Our findings suggest that amino acid type is a very important engineering parameter to mediate

  8. No Bridge Too High: Infants Decide Whether to Cross Based on the Probability of Falling not the Severity of the Potential Fall

    ERIC Educational Resources Information Center

    Kretch, Kari S.; Adolph, Karen E.

    2013-01-01

    Do infants, like adults, consider both the probability of falling and the severity of a potential fall when deciding whether to cross a bridge? Crawling and walking infants were encouraged to cross bridges varying in width over a small drop-off, a large drop-off, or no drop-off. Bridge width affects the probability of falling, whereas drop-off…

  9. Detachment of low-force bridges contributes to the rapid tension transients of skinned rabbit skeletal muscle fibres.

    PubMed Central

    Seow, C Y; Shroff, S G; Ford, L E

    1997-01-01

    under the reference condition. BDM therefore appeared to augment the fastest component of the tension transient under the reference condition. 5. The results suggest that BDM detains cross-bridges in low-force, attached states. Since these bridges are attached, they contribute to sarcomere stiffness. Since they are detained, relaxation or reversal of their immediate responses is probably due to bridge detachment rather than to their undergoing the power stroke. The observation that a portion of the test response matched the fastest component of the reference response when the amplitude of the fastest component was increased suggests that a part of the normal rapid, transient tension recovery following a release step is due to detachment of low-force bridges moved to negative-force positions by the step. PMID:9175000

  10. Orientation of cross-bridges in skeletal muscle measured with a hydrophobic probe.

    PubMed

    Xiao, M; Borejdo, J

    1997-05-01

    Cis-parinaric acid (PA) binds to a hydrophobic pocket formed between the heavy chain of myosin subfragment-1 (S1) and the 41-residue N-terminal of essential light chain 1 (A1). The binding is strong (Ka = 5.6 x 10(7) M-1) and rigid (polarization = 0.334). PA does not bind to myofibrils in which A1 has been extracted or replaced with alkali light chain 2 (A2). As in the case of S1 labeled with other probes, polarization of fluorescence of S1-PA added to myofibrils depended on fractional saturation of actin filament with S1, i.e., on whether the filaments were fully or partially saturated with myosin heads. Because fluorescence quantum yield of PA is enhanced manyfold upon binding, and because PA binds weakly to myofibrillar structures other then A1, the dye is a convenient probe of cross-bridge orientation in native muscle fibers. The polarization of a fiber irrigated with PA was equal to the polarization of S1-PA added to fibers at nonsaturating concentration. Cross-linking of S1 added to fibers at nonsaturating concentration showed that each S1 bound to two actin monomers of a thin filament. These results suggest that in rigor rabbit psoas muscle fiber each myosin cross-bridge binds to two actins. PMID:9129830

  11. Working with Immigrant Students in Schools: The Role of School Counselors in Building Cross-Cultural Bridges

    ERIC Educational Resources Information Center

    Goh, Michael; Wahl, Kay Herting; McDonald, Julie Koch; Brissett, Annette A.; Yoon, Eunju

    2007-01-01

    School counselors are poised to play a significant role within comprehensive school counseling programs in addressing the needs of immigrant children in schools. The authors describe how school counselors can have a positive impact on the adjustment of immigrant students by building cross-cultural bridges through the use of cross-cultural…

  12. Insights into length-dependent regulation of cardiac cross-bridge cycling kinetics in human myocardium.

    PubMed

    Milani-Nejad, Nima; Chung, Jae-Hoon; Canan, Benjamin D; Davis, Jonathan P; Fedorov, Vadim V; Higgins, Robert S D; Kilic, Ahmet; Mohler, Peter J; Janssen, Paul M L

    2016-07-01

    Cross-bridge cycling kinetics play an essential role in the heart's ability to contract and relax. The rate of tension redevelopment (ktr) slows down as a muscle length is increased in intact human myocardium. We set out to determine the effect of rapid length step changes and protein kinase A (PKA) and protein kinase C-βII (PKC-βII) inhibitors on the ktr in ultra-thin non-failing and failing human right ventricular trabeculae. After stabilizing the muscle either at L90 (90% of optimal length) or at Lopt (optimal length), we rapidly changed the length to either Lopt or L90 and measured ktr. We report that length-dependent changes in ktr occur very rapidly (in the order of seconds or faster) in both non-failing and failing muscles and that the length at which a muscle had been stabilized prior to the length change does not significantly affect ktr. In addition, at L90 and at Lopt, PKA and PKC-βII inhibitors did not significantly change ktr. Our results reveal that length-dependent regulation of cross-bridge cycling kinetics predominantly occurs rapidly and involves the intrinsic properties of the myofilament rather than post-translational modifications that are known to occur in the cardiac muscle as a result of a change in muscle/sarcomere length. PMID:26854725

  13. Strain-dependent cross-bridge cycle for muscle. II. Steady-state behavior.

    PubMed Central

    Smith, D A; Geeves, M A

    1995-01-01

    Quantitative predictions of steady-state muscle properties from the strain-dependent cross-bridge for muscle are presented. With a stiffness of 5.4 x 10(-4) N/m per head, a throw distance of 11 nm, and three allowed actin sites/head, isometric properties and their dependence on phosphate and nucleotide levels are well described if the tension-generating step occurs before phosphate release. At very low ATP levels, rigorlike states with negative strain are predicted. The rate-limiting step for cycling and ATP consumption is strain-blocked ADP release for isometric and slowly shortening muscle. Under rapid shortening, ATP hydrolysis on detached heads is the rate-limiting step, and the ratio of bound ATP to bound ADP.Pi increases by a factor of 7. At large positive strains, bound heads must be forcibly detached from actin to account for tension in rapid extension, but forced detachment in shortening has no effect without destroying isometric attached states. Strain-blocked phosphate release as proposed produces modest inhibition of the ATPase rate under rapid shortening, sufficient to give a maximum for one actin site per helix turn. Alternative cross-bridge models are discussed in the light of these predictions. PMID:8527668

  14. Using optical tweezers to relate the chemical and mechanical cross-bridge cycles.

    PubMed Central

    Steffen, Walter; Sleep, John

    2004-01-01

    In most current models of muscle contraction there are two translational steps, the working stroke, whereby an attached myosin cross-bridge moves relative to the actin filament, and the repriming step, in which the cross-bridge returns to its original orientation. The development of single molecule methods has allowed a more detailed investigation of the relationship of these mechanical steps to the underlying biochemistry. In the normal adenosine triphosphate cycle, myosin.adenosine diphosphate.phosphate (M.ADP.Pi) binds to actin and moves it by ca. 5 nm on average before the formation of the end product, the rigor actomyosin state. All the other product-like intermediate states tested were found to give no net movement indicating that M.ADP.Pi alone binds in a pre-force state.Myosin states with bound, unhydrolysed nucleoside triphosphates also give no net movement, indicating that these must also bind in a post-force conformation and that the repriming, post- to pre-transition during the forward cycle must take place while the myosin is dissociated from actin. These observations fit in well with the structural model in which the working stroke is aligned to the opening of the switch 2 element of the ATPase site. PMID:15647161

  15. Cardiac Myosin Binding Protein C Phosphorylation Affects Cross-Bridge Cycle's Elementary Steps in a Site-Specific Manner

    PubMed Central

    Wang, Li; Sadayappan, Sakthivel; Kawai, Masakata

    2014-01-01

    Based on our recent finding that cardiac myosin binding protein C (cMyBP-C) phosphorylation affects muscle contractility in a site-specific manner, we further studied the force per cross-bridge and the kinetic constants of the elementary steps in the six-state cross-bridge model in cMyBP-C mutated transgenic mice for better understanding of the influence of cMyBP-C phosphorylation on contractile functions. Papillary muscle fibres were dissected from cMyBP-C mutated mice of ADA (Ala273-Asp282-Ala302), DAD (Asp273-Ala282-Asp302), SAS (Ser273-Ala282-Ser302), and t/t (cMyBP-C null) genotypes, and the results were compared to transgenic mice expressing wide-type (WT) cMyBP-C. Sinusoidal analyses were performed with serial concentrations of ATP, phosphate (Pi), and ADP. Both t/t and DAD mutants significantly reduced active tension, force per cross-bridge, apparent rate constant (2πc), and the rate constant of cross-bridge detachment. In contrast to the weakened ATP binding and enhanced Pi and ADP release steps in t/t mice, DAD mice showed a decreased ADP release without affecting the ATP binding and the Pi release. ADA showed decreased ADP release, and slightly increased ATP binding and cross-bridge detachment steps, whereas SAS diminished the ATP binding step and accelerated the ADP release step. t/t has the broadest effects with changes in most elementary steps of the cross-bridge cycle, DAD mimics t/t to a large extent, and ADA and SAS predominantly affect the nucleotide binding steps. We conclude that the reduced tension production in DAD and t/t is the result of reduced force per cross-bridge, instead of the less number of strongly attached cross-bridges. We further conclude that cMyBP-C is an allosteric activator of myosin to increase cross-bridge force, and its phosphorylation status modulates the force, which is regulated by variety of protein kinases. PMID:25420047

  16. Mechanical regulation of cardiac muscle by coupling calcium kinetics with cross-bridge cycling: a dynamic model.

    PubMed

    Landesberg, A; Sideman, S

    1994-08-01

    This study describes the regulation of mechanical activity in the intact cardiac muscle, the effects of the free calcium transients and the mechanical constraints, and emphasizes the central role of the troponin complex in regulating muscle activity. A "loose coupling" between calcium binding to troponin and cross-bridge cycling is stipulated, allowing the existence of cross bridges in the strong conformation without having bound calcium on the neighboring troponin. The model includes two feedback mechanisms: 1) a positive feedback, or cooperativity, in which the cycling cross bridges affect the affinity of troponin for calcium, and 2) a negative mechanical feedback, where the filament-sliding velocity affects cross-bridge cycling. The model simulates the reported experimental force-length and force-velocity relationships at different levels of activation. The dependence of the shortening velocity on calcium concentration, sarcomere length, internal load, and rate of cross-bridge cycling is described analytically in agreement with reported data. Furthermore, the model provides an analytic solution for Hill's equation of the force-velocity relationship and for the phenomena of unloaded shortening velocity and force deficit. The model-calculated changes in free calcium in various mechanical conditions are in good agreement with the available experimental results. PMID:8067434

  17. Increased Titin Compliance Reduced Length-Dependent Contraction and Slowed Cross-Bridge Kinetics in Skinned Myocardial Strips from Rbm (20ΔRRM) Mice.

    PubMed

    Pulcastro, Hannah C; Awinda, Peter O; Methawasin, Mei; Granzier, Henk; Dong, Wenji; Tanner, Bertrand C W

    2016-01-01

    Titin is a giant protein spanning from the Z-disk to the M-band of the cardiac sarcomere. In the I-band titin acts as a molecular spring, contributing to passive mechanical characteristics of the myocardium throughout a heartbeat. RNA Binding Motif Protein 20 (RBM20) is required for normal titin splicing, and its absence or altered function leads to greater expression of a very large, more compliant N2BA titin isoform in Rbm20 homozygous mice (Rbm20 (ΔRRM) ) compared to wild-type mice (WT) that almost exclusively express the stiffer N2B titin isoform. Prior studies using Rbm20 (ΔRRM) animals have shown that increased titin compliance compromises muscle ultrastructure and attenuates the Frank-Starling relationship. Although previous computational simulations of muscle contraction suggested that increasing compliance of the sarcomere slows the rate of tension development and prolongs cross-bridge attachment, none of the reported effects of Rbm20 (ΔRRM) on myocardial function have been attributed to changes in cross-bridge cycling kinetics. To test the relationship between increased sarcomere compliance and cross-bridge kinetics, we used stochastic length-perturbation analysis in Ca(2+)-activated, skinned papillary muscle strips from Rbm20 (ΔRRM) and WT mice. We found increasing titin compliance depressed maximal tension, decreased Ca(2+)-sensitivity of the tension-pCa relationship, and slowed myosin detachment rate in myocardium from Rbm20 (ΔRRM) vs. WT mice. As sarcomere length increased from 1.9 to 2.2 μm, length-dependent activation of contraction was eliminated in the Rbm20 (ΔRRM) myocardium, even though myosin MgADP release rate decreased ~20% to prolong strong cross-bridge binding at longer sarcomere length. These data suggest that increasing N2BA expression may alter cardiac performance in a length-dependent manner, showing greater deficits in tension production and slower cross-bridge kinetics at longer sarcomere length. This study also supports the

  18. Increased Titin Compliance Reduced Length-Dependent Contraction and Slowed Cross-Bridge Kinetics in Skinned Myocardial Strips from Rbm20ΔRRM Mice

    PubMed Central

    Pulcastro, Hannah C.; Awinda, Peter O.; Methawasin, Mei; Granzier, Henk; Dong, Wenji; Tanner, Bertrand C. W.

    2016-01-01

    Titin is a giant protein spanning from the Z-disk to the M-band of the cardiac sarcomere. In the I-band titin acts as a molecular spring, contributing to passive mechanical characteristics of the myocardium throughout a heartbeat. RNA Binding Motif Protein 20 (RBM20) is required for normal titin splicing, and its absence or altered function leads to greater expression of a very large, more compliant N2BA titin isoform in Rbm20 homozygous mice (Rbm20ΔRRM) compared to wild-type mice (WT) that almost exclusively express the stiffer N2B titin isoform. Prior studies using Rbm20ΔRRM animals have shown that increased titin compliance compromises muscle ultrastructure and attenuates the Frank-Starling relationship. Although previous computational simulations of muscle contraction suggested that increasing compliance of the sarcomere slows the rate of tension development and prolongs cross-bridge attachment, none of the reported effects of Rbm20ΔRRM on myocardial function have been attributed to changes in cross-bridge cycling kinetics. To test the relationship between increased sarcomere compliance and cross-bridge kinetics, we used stochastic length-perturbation analysis in Ca2+-activated, skinned papillary muscle strips from Rbm20ΔRRM and WT mice. We found increasing titin compliance depressed maximal tension, decreased Ca2+-sensitivity of the tension-pCa relationship, and slowed myosin detachment rate in myocardium from Rbm20ΔRRM vs. WT mice. As sarcomere length increased from 1.9 to 2.2 μm, length-dependent activation of contraction was eliminated in the Rbm20ΔRRM myocardium, even though myosin MgADP release rate decreased ~20% to prolong strong cross-bridge binding at longer sarcomere length. These data suggest that increasing N2BA expression may alter cardiac performance in a length-dependent manner, showing greater deficits in tension production and slower cross-bridge kinetics at longer sarcomere length. This study also supports the idea that passive

  19. Measuring myosin cross-bridge attachment time in activated muscle fibers using stochastic vs. sinusoidal length perturbation analysis

    PubMed Central

    Wang, Yuan; Maughan, David W.; Palmer, Bradley M.

    2011-01-01

    The average time myosin cross bridges remain bound to actin (ton) can be measured by sinusoidal length perturbations (sinusoidal analysis) of striated muscle fibers using recently developed analytic methods. This approach allows measurements of ton in preparations possessing a physiologically relevant myofilament lattice. In this study, we developed an approach to measure ton in 5–10% of the time required for sinusoidal analysis by using stochastic length perturbations (white noise analysis). To compare these methods, we measured the influence of MgATP concentration ([MgATP]) on ton in demembranated myocardial strips from mice, sampling muscle behavior from 0.125 to 200 Hz with a 20-s burst of white noise vs. a 300-s series of sinusoids. Both methods detected a similar >300% increase in ton as [MgATP] decreased from 5 to 0.25 mM, differing by only 3–14% at any [MgATP]. Additional experiments with Drosophila indirect flight muscle fibers demonstrated that faster cross-bridge cycling kinetics permit further reducing of the perturbation time required to measure ton. This reduced sampling time allowed strain-dependent measurements of ton in flight muscle fibers by combining 10-s bursts of white noise during periods of linear shortening and lengthening. Analyses revealed longer ton values during shortening and shorter ton values during lengthening. This asymmetry may provide a mechanism that contributes to oscillatory energy transfer between the flight muscles and thoracic cuticle to power flight. This study demonstrates that white noise analysis can detect underlying molecular processes associated with dynamic muscle contraction comparable to sinusoidal analysis, but in a fraction of the time. PMID:21233339

  20. Level II scour analysis for Bridge 42 (BETHTH00860042) on Town Highway 86, crossing Gilead Brook, Bethel, Vermont

    USGS Publications Warehouse

    Ayotte, Joseph D.; Song, Donald L.

    1996-01-01

    Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0 to 1.9 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge and the 100-year discharge. Abutment scour ranged from 8.6 to 15.7 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Many factors, including historical performance during flood events, the geomorphic assessment, scour protection, and the results of the hydraulic analyses, must be considered to properly assess the validity of abutment scour results. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein, based on the consideration of additional contributing factors and engineering judgement.

  1. Level II scour analysis for Bridge 42 (BRIDTH00040042) on Town Highway 04, crossing Dailey Hollow Brook, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Weber, Matthew A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BRIDTH00040042 on town highway 4 crossing Dailey Hollow Brook, Bridgewater, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). A Level I study is included in Appendix E of this report. A Level I study provides a qualitative geomorphic characterization of the study site. Information on the bridge available from VTAOT files was compiled prior to conducting Level I and Level II analyses and can be found in Appendix D. The site is in the Green Mountain physiographic division of central Vermont in the town of Bridgewater. The 2.20-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the overbanks are covered by shrubs and trees except for the upstream right overbank where there is a house. Dailey Hollow Brook enters Dailey Hollow Branch at the downstream face of the bridge. In the study area, Dailey Hollow Brook has an incised, sinuous channel with a slope of approximately 0.035 ft/ft. The channel top width and channel depth upstream of the bridge is 19 ft and 3 ft, respectively. Downstream of the bridge and the confluence the channel top width and channel depth is 39 ft and 2 ft respectively. The predominant channel bed material is cobble and gravel (D50 is 64.7 mm or 0.212 ft). The geomorphic assessment at the time of the Level I and Level II site visit on November 1, 1994, indicated that the reach was stable. The town highway 4 crossing of Dailey Hollow Brook is a 25-ft-long, one-lane bridge consisting of one 23-foot concrete span (Vermont Agency of Transportation, written communication, August 25, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. Type-2 stone fill (less than 36 inches) exists along all four wingwalls, the downstream right road approach

  2. COOH-terminal truncation of flightin decreases myofilament lattice organization, cross-bridge binding, and power output in Drosophila indirect flight muscle

    SciTech Connect

    Tanner, Bertrand C.W.; Miller, Mark S.; Miller, Becky M.; Lekkas, Panagiotis; Irving, Thomas C.; Maughan, David W.; Vigoreaux, Jim O.

    2011-08-26

    The indirect flight muscle (IFM) of insects is characterized by a near crystalline myofilament lattice structure that likely evolved to achieve high power output. In Drosophila IFM, the myosin rod binding protein flightin plays a crucial role in thick filament organization and sarcomere integrity. Here we investigate the extent to which the COOH terminus of flightin contributes to IFM structure and mechanical performance using transgenic Drosophila expressing a truncated flightin lacking the 44 COOH-terminal amino acids (fln{sup {Delta}C44}). Electron microscopy and X-ray diffraction measurements show decreased myofilament lattice order in the fln{sup {Delta}C44} line compared with control, a transgenic flightin-null rescued line (fln{sup +}). fln{sup {Delta}C44} fibers produced roughly 1/3 the oscillatory work and power of fln{sup +}, with reduced frequencies of maximum work (123 Hz vs. 154 Hz) and power (139 Hz vs. 187 Hz) output, indicating slower myosin cycling kinetics. These reductions in work and power stem from a slower rate of cross-bridge recruitment and decreased cross-bridge binding in fln{sup {Delta}C44} fibers, although the mean duration of cross-bridge attachment was not different between both lines. The decreases in lattice order and myosin kinetics resulted in fln{sup {Delta}C44} flies being unable to beat their wings. These results indicate that the COOH terminus of flightin is necessary for normal myofilament lattice organization, thereby facilitating the cross-bridge binding required to achieve high power output for flight.

  3. Faster cross-bridge detachment and increased tension cost in human hypertrophic cardiomyopathy with the R403Q MYH7 mutation

    PubMed Central

    Witjas-Paalberends, E Rosalie; Ferrara, Claudia; Scellini, Beatrice; Piroddi, Nicoletta; Montag, Judith; Tesi, Chiara; Stienen, Ger J M; Michels, Michelle; Ho, Carolyn Y; Kraft, Theresia; Poggesi, Corrado; van der Velden, Jolanda

    2014-01-01

    The first mutation associated with hypertrophic cardiomyopathy (HCM) is the R403Q mutation in the gene encoding β-myosin heavy chain (β-MyHC). R403Q locates in the globular head of myosin (S1), responsible for interaction with actin, and thus motor function of myosin. Increased cross-bridge relaxation kinetics caused by the R403Q mutation might underlie increased energetic cost of tension generation; however, direct evidence is absent. Here we studied to what extent cross-bridge kinetics and energetics are related in single cardiac myofibrils and multicellular cardiac muscle strips of three HCM patients with the R403Q mutation and nine sarcomere mutation-negative HCM patients (HCMsmn). Expression of R403Q was on average 41 ± 4% of total MYH7 mRNA. Cross-bridge slow relaxation kinetics in single R403Q myofibrils was significantly higher (P < 0.0001) than in HCMsmn myofibrils (0.47 ± 0.02 and 0.30 ± 0.02 s−1, respectively). Moreover, compared to HCMsmn, tension cost was significantly higher in the muscle strips of the three R403Q patients (2.93 ± 0.25 and 1.78 ± 0.10 μmol l–1 s−1 kN−1 m−2, respectively) which showed a positive linear correlation with relaxation kinetics in the corresponding myofibril preparations. This correlation suggests that faster cross-bridge relaxation kinetics results in an increase in energetic cost of tension generation in human HCM with the R403Q mutation compared to HCMsmn. Therefore, increased tension cost might contribute to HCM disease in patients carrying the R403Q mutation. PMID:24928957

  4. Level II scour analysis for Bridge 46 (BRIDTH00050046) on Town Highway 05, crossing North Branch Ottauquechee River, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Song, Donald L.

    1996-01-01

    bridge consisting of a 34-ft steel-beam span, supported by vertical abutments with no wingwalls (Vermont Agency of Transportation, written communication, August 25, 1994). The left abutment is stone; the right abutment is log cribwork with type-2 stone fill (less than 36 inches diameter) along its base. Type-2 stone fill has also been placed on the upstream and downstream sides of the road embankments, except the upstream left which has type-3 (less than 48 inches diameter). The channel is skewed approximately 60 degrees; the opening-skew-to-roadway is 30 degrees. Additional details describing conditions at the site are included in the Level II Summary, Appendix D, and Appendix E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a highway crossing is comprised of three components: 1) long-term degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of these computed results follow. Contraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 5.7 ft to 7.7 ft. with the worst-case abutment scour occurring at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated depths, are presented in tables 1 and 2. A cross-section of the computed scour at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths

  5. Flow-velocity and depth data during peak discharge events at selected bridge crossings in North Carolina, 1964-98

    USGS Publications Warehouse

    Pope, Benjamin F.

    2000-01-01

    Flow-velocity and depth data were collected from July 1996 through December 1998 during peak discharge events at 21 bridge crossings that are adjacent to U.S. Geological Survey streamgaging stations in North Carolina. These data were collected during measurements of peak discharges that had recurrence intervals ranging from less than 2 years to about 100 years. The velocity and depth data can be used to evaluate predicted flow velocities and scour depths that are computed as part of scour analyses at the selected bridge crossings.

  6. An amateur's contribution to the design of Telford's Menai Suspension Bridge: a commentary on Gilbert (1826) 'On the mathematical theory of suspension bridges'.

    PubMed

    Calladine, C R

    2015-04-13

    Davies Gilbert's work on the catenary is notable on two counts. First, it influenced Thomas Telford in formulating his final design for the Menai Strait suspension bridge (1826); and second, it established for the first time the form of the 'catenary of equal strength'. The classical catenary is a uniform flexible chain or cable hanging freely under gravity between supports. The 'catenary of equal strength' is the form of a cable whose cross-sectional area is made proportional to the tension at each point, so that the tensile stress is uniform throughout. In this paper I provide a sketch of the lives and achievements of Gilbert and Telford, and of their interaction over the Menai Bridge. There follows a commentary on Gilbert's 1826 paper, and on his two related publications; and a brief sketch of the earlier history of the catenary. I then describe the development of the suspension bridge up to the present time. Finally, I discuss relations between mathematical analysts and practical engineers. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. PMID:25750153

  7. Fluctuations in polarized fluorescence: evidence that muscle cross bridges rotate repetitively during contraction.

    PubMed Central

    Borejdo, J; Putnam, S; Morales, M F

    1979-01-01

    Particular thiols of the myosin subfragment 1 moieties of single glycerinated muscle fibers are covalently labeled with rhodamine. By using appropriate solutions such fibers can be relaxed, be in rigor, or develop active isometric tension. The rhodamine is excited by polarized 514.5-nm laser light; the greater than 580-nm fluorescence is resolved into orthogonal components and the intensity of each is measured by a computer-interfaced photon counting system. Fluctuations over-and-above noise appear in steady-state activity but not in relaxation or rigor and not when the fluorophore is actin-attached instead of myosin-attached. Fluctuations also appear in ratios of polarized intensities--quantities sensitive to fluorophore attitude but not to fluorophore number. The fluctuations are dominated by low (approximately 2 Hz) frequencies similar to separately measured ATPase frequencies. The fluctuations are ascribed to repetitive motion of the cross bridges to which the rhodamine is attached. Images PMID:160564

  8. Columbia River monitoring: Summary of chemical monitoring along cross sections at Vernita Bridge and Richland

    SciTech Connect

    Dirkes, R.L.; Patton, G.W.; Tiller, B.L.

    1993-05-01

    This report presents the results of the chemical monitoring performed by the Surface Environmental Surveillance Project (SESP) along cross sections of the Columbia River established at Vernita Bridge and the Richland Pumphouse. Potential Hanford-origin chemical constituents of interest were selected based on their presence in ground water near the river, past surveillance efforts that have documented their entry into the river, and reviews of special study reports, CERCIA remedial investigation/feasibility study (RI/FS) documentation, RCRA facility investigation/corrective measure (FI/CW) study plans, and preliminary risk assessments. Results presented in this report include volatile organic compounds, metals, and anions. The data were generated as part of the routine Columbia River monitoring program currently conducted as part of the SESP.

  9. Bridging refugee youth and children's services: a case study of cross-service training.

    PubMed

    Morland, Lyn; Duncan, Julianne; Hoebing, Joyce; Kirschke, Juanita; Schmidt, Laura

    2005-01-01

    Bridging Refugee Youth and Children's Services(BRYCS), a public-private partnership between the federal Office of Refugee Resettlement, Lutheran Immigration and Refugee Service, and the United States Conference of Catholic Bishops, provides national technical assistance to public child welfare. After a series of "community conversations," BRYCS identified a lack of knowledge among child welfare staff about newcomer refugees, negative stereotypes, and a fear of child protective services among refugees. BRYCS initiated a number of technical assistance initiatives, including a pilot cross-service training project in St. Louis to strengthen collaboration between child welfare and refugee-serving agencies. This article details the lessons learned from this training and recommends changes in policy and practice. PMID:16435662

  10. Synthesis and Evaluation of New Generation Cross-Bridged Bifunctional Chelator for (64)Cu Radiotracers.

    PubMed

    Dale, Ajit V; An, Gwang Il; Pandya, Darpan N; Ha, Yeong Su; Bhatt, Nikunj; Soni, Nisarg; Lee, Hochun; Ahn, Heesu; Sarkar, Swarbhanu; Lee, Woonghee; Huynh, Phuong Tu; Kim, Jung Young; Gwon, Mi-Ri; Kim, Sung Hong; Park, Jae Gyu; Yoon, Young-Ran; Yoo, Jeongsoo

    2015-09-01

    Bifunctional chelators have been successfully used to construct (64)Cu-labeled radiopharmaceuticals. Previously reported chelators with cross-bridged cyclam backbones have various essential features such as high stability of the copper(II) complex, high efficiency of radiolabeling at room temperature, and good biological inertness of the radiolabeled complex, along with rapid body clearance. Here, we report a new generation propylene-cross-bridged chelator with hybrid acetate/phosphonate pendant groups (PCB-TE1A1P) developed with the aim of combining these key properties in a single chelator. The PCB-TE1A1P was synthesized from cyclam with good overall yield. The Cu(II) complex of our chelator showed good robustness in kinetic stability evaluation experiments, such as acidic decomplexation and cyclic voltammetry studies. The Cu(II) complex of PCB-TE1A1P remained intact under highly acidic conditions (12 M HCl, 90 °C) for 8 d and showed quasi-reversible reduction/oxidation peaks at -0.77 V in electrochemical studies. PCB-TE1A1P was successfully radiolabeled with (64)Cu ions in an acetate buffer at 60 °C within 60 min. The electrophoresis study revealed that the (64)Cu-PCB-TE1A1P complex has net negative charge in aqueous solution. The biodistribution and in vivo stability study profiles of (64)Cu-PCB-TE1A1P indicated that the radioactive complex was stable under physiological conditions and cleared rapidly from the body. A whole body positron emission tomography (PET) imaging study further confirmed high in vivo stability and fast clearance of the complex in mouse models. In conclusion, PCB-TE1A1P has good potential as a bifunctional chelator for (64)Cu-based radiopharmaceuticals, especially those involving peptides. PMID:26286436

  11. Three-dimensional disorder of dipolar probes in a helical array. Application to muscle cross-bridges.

    PubMed Central

    Mendelson, R A; Wilson, M G

    1982-01-01

    Fluorescence polarization and EPR experiments on azimuthally randomized helices bearing extrinsic (dipolar) probes yield information about the axial orientation and order of the probes. If the orientation of the probe on the structure bearing it is known and disorder is absent, the orientation of the structure may be ascertained. For cases where less probe orientation information is available and/or disorder is present, the available structural information is correspondingly reduced. Here we examine the available data on probes attached to cross-bridges in muscle fibers: four plausible cases of three-dimensional cross-bridge disorders are numerically modeled muscle in states of rigor and relaxation. In rigor, where the reported probe disorder is small (Thomas and Cooke, 1980), it was found that the cross-bridge disorder was also small. On the other hand, for the relaxed state where the probes are found to be completely disordered, the cross-bridges may have a considerable amount of order. This possibility is in concert with the results of x-ray diffraction, in which the presence of well-developed myosin-based layer lines indicates considerable order in relaxed muscle. PMID:6288134

  12. Theoretical and experimental studies on cross-bridge migration during cell disaggregation.

    PubMed Central

    Tozeren, A; Sung, K L; Chien, S

    1989-01-01

    A micromanipulation method is used to determine the adhesive energy density (gamma) between pairs of cytotoxic T cells (F1) and their target cells (JY: HLA-A2-B7-DR4,W6). gamma is defined as the energy per unit area that must be supplied to reduce the region of contact between a conjugated cell pair. Our analysis of the data indicates that the force applied by the micropipette on the cell is not uniformly distributed throughout the contact region as we had previously assumed (Sung, K. L. P., L. A. Sung, M. Crimmins, S. J. Burakoff, and S. Chien. 1986. Science (Wash. DC). 234: 1405-1408), but acts only at the edges of the contact region. We show that gamma is not constant during peeling but increases with decreasing contact area of the conjugated cell pairs F1-JY, F1-F1, and JY-JY in contrast to the constancy of gamma for typical engineering adhesives. This finding supports the notion that the cross-linking protein molecules slide towards the conjugated area across the leading edge of the separation while remaining attached to both cells. Our mathematical analysis shows that the elastic energy stored in the cross-links by the membrane tensions balances the diffusive forces that act against cross-bridge migration. The binding affinity between F1-JY is found to be approximately 15-20 times larger than the corresponding affinity for F1-F1. The number of binding sites of F1 for attachment to JY is approximately the same for binding F1 to another F1 and vary between 10(5) and 10(6). Images FIGURE 1 PMID:2784694

  13. Level II scour analysis for Bridge 24 (WODSTH00190024) on Town Highway 19, crossing North Bridgewater Brook, Woodstock, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Song, Donald L.

    1996-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.8 ft. Abutment scour ranged from 6.6 to 14.9 ft. with the worst-case scenario occurring at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, including historical performance during flood events, the geomorphic assessment, scour protection measures, and the results of the hydraulic analyses, must be considered to properly assess the validity of abutment scour results. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein, based on the consideration of additional contributing factors and experienced engineering judgement.

  14. Level II scour analysis for Bridge 35 (BETHTH00190035) on Town Highway 19, crossing Gilead Brook, Bethel, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Song, Donald L.

    1996-01-01

    abutments with wingwalls. The channel is skewed approximately 5 degrees to the opening while the opening-skew-to-roadway is 10 degrees. The scour protection measures at the site included type-1 stone fill (less than 12 inches diameter) at the downstream wingwalls, left abutment, and upstream right road embankment; type-2 stone fill (less than 36 inches diameter) is at the upstream right wingwall. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0.1 to 2.1 ft. with the worst-case scenario occurring at the 500-year discharge. Abutment scour ranged from 3.9 to 9.5 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, including historical

  15. Level II scour analysis for Bridge 25 (BRNATH00290034) on Town Highway 29, crossing Locust Creek, Barnard, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Weber, Matthew A.

    1996-01-01

    The Town Highway 29 crossing of Locust Creek is a 37-ft-long, one-lane bridge consisting of one 32-foot concrete span (Vermont Agency of Transportation, written communication, August 23, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 25 degrees to the opening while the opening-skew-to-roadway is 25 degrees. There was no observable scour protection measure at the site. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.

  16. Age-related slowing of myosin actin cross-bridge kinetics is sex specific and predicts decrements in whole skeletal muscle performance in humans

    PubMed Central

    Bedrin, Nicholas G.; Callahan, Damien M.; Previs, Michael J.; Jennings, Mark E.; Ades, Philip A.; Maughan, David W.; Palmer, Bradley M.; Toth, Michael J.

    2013-01-01

    We hypothesize that age-related skeletal muscle dysfunction and physical disability may be partially explained by alterations in the function of the myosin molecule. To test this hypothesis, skeletal muscle function at the whole muscle, single fiber, and molecular levels was measured in young (21–35 yr) and older (65–75 yr) male and female volunteers with similar physical activity levels. After adjusting for muscle size, older adults had similar knee extensor isometric torque values compared with young, but had lower isokinetic power, most notably in women. At the single-fiber and molecular levels, aging was associated with increased isometric tension, slowed myosin actin cross-bridge kinetics (longer myosin attachment times and reduced rates of myosin force production), greater myofilament lattice stiffness, and reduced phosphorylation of the fast myosin regulatory light chain; however, the age effect was driven primarily by women (i.e., age-by-sex interaction effects). In myosin heavy chain IIA fibers, single-fiber isometric tension and molecular level mechanical and kinetic indexes were correlated with whole muscle isokinetic power output. Collectively, considering that contractile dysfunction scales up through various anatomical levels, our results suggest a potential sex-specific molecular mechanism, reduced cross-bridge kinetics, contributes to the reduced physical capacity with aging in women. Thus these results support our hypothesis that age-related alterations in the myosin molecule contribute to skeletal muscle dysfunction and physical disability and indicate that this effect is stronger in women. PMID:23887900

  17. Dynamics of cross-bridge cycling, ATP hydrolysis, force generation, and deformation in cardiac muscle.

    PubMed

    Tewari, Shivendra G; Bugenhagen, Scott M; Palmer, Bradley M; Beard, Daniel A

    2016-07-01

    Despite extensive study over the past six decades the coupling of chemical reaction and mechanical processes in muscle dynamics is not well understood. We lack a theoretical description of how chemical processes (metabolite binding, ATP hydrolysis) influence and are influenced by mechanical processes (deformation and force generation). To address this need, a mathematical model of the muscle cross-bridge (XB) cycle based on Huxley's sliding filament theory is developed that explicitly accounts for the chemical transformation events and the influence of strain on state transitions. The model is identified based on elastic and viscous moduli data from mouse and rat myocardial strips over a range of perturbation frequencies, and MgATP and inorganic phosphate (Pi) concentrations. Simulations of the identified model reproduce the observed effects of MgATP and MgADP on the rate of force development. Furthermore, simulations reveal that the rate of force re-development measured in slack-restretch experiments is not directly proportional to the rate of XB cycling. For these experiments, the model predicts that the observed increase in the rate of force generation with increased Pi concentration is due to inhibition of cycle turnover by Pi. Finally, the model captures the observed phenomena of force yielding suggesting that it is a result of rapid detachment of stretched attached myosin heads. PMID:25681584

  18. Level II scour analysis for Bridge 30 (BRIDTH00330030) on Town Highway 33, crossing Dailey Hollow Branch, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Song, Donald L.

    1996-01-01

    using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0.5 to 3.1 ft. The worst-case contraction scour occurred at the incipient-roadway-overtopping discharge, which is between the 100- and 500-year discharge. Abutment scour ranged from 6.9 to 14.6 ft. with the worst-case scenario also occurring at the incipient-roadway-overtopping discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, including historical performance during flood events, the geomorphic assessment, scour protection measures, and the results of the hydraulic analyses, must be considered to properly assess the validity of abutment scour results. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein, based on the consideration of additional contributing factors and experienced engineering judgement.

  19. Exchange of ATP for ADP on high-force cross-bridges of skinned rabbit muscle fibers.

    PubMed Central

    Seow, C Y; Ford, L E

    1997-01-01

    The contractile properties of rabbit skinned muscle fibers were studied at 1-2 degrees C in different concentrations of MgATP and MgADP. Double-reciprocal plots of maximum velocity against MgATP concentration at different MgADP concentrations all extrapolated to the same value. This finding suggests that MgATP and MgADP compete for the same site on the cross-bridge, and that the exchange of MgATP for MgADP occurs without a detectable step intervening. The K(m) for ATP was 0.32 mM. The K(i) for MgADP was 0.33 mM. Control experiments suggested that the tortuosity of diffusion paths within the fibers reduced the radial diffusion coefficients for reactants about sixfold. Increasing MgADP from 0.18 to 2 mM at 5 mM ATP or lowering MgATP from 10 to 2 mM at 0.18 mM MgADP, respectively, increased isometric force by 25% and 23%, increased stiffness by 10% and 20%, and decreased maximum velocity by 35% and 31%. Two mechanisms appeared to be responsible. One detained bridges in high-force states, where they recovered from a length step with a slower time course. The other increased the fraction of attached bridges without altering the kinetics of their responses, possibly by an increased activation resulting from cooperative effects of the detained, high-force bridges. The rigor bridge was more effective than the ADP-bound bridge in increasing the number of attached bridges with unaltered kinetics. PMID:9168047

  20. Repeated multibeam echosounder hydrographic surveys of 15 selected bridge crossings along the Missouri River from Niobrara to Rulo, Nebraska, during the flood of 2011

    USGS Publications Warehouse

    Dietsch, Benjamin J.; Densmore, Brenda K.; Strauch, Kellan R.

    2014-01-01

    In 2011, unprecedented flooding in the Missouri River prompted transportation agencies to increase the frequency of monitoring riverbed elevations near bridges that cross the Missouri River. Hydrographic surveys were completed in cooperation with the Nebraska Department of Roads, using a multibeam echosounder at 15 highway bridges spanning the Missouri River from Niobrara to Rulo, Nebraska during and after the extreme 2011 flood. Evidence of bed elevation change near bridge piers was documented. The greatest amount of bed elevation change during the 2011 flood documented for this study occurred at the Burt County Missouri River Bridge at Decatur, Nebraska, where scour of about 45 feet, from before flooding, occurred between a bridge abutment and pier. Of the remaining sites, highway bridges where bed elevation change near piers appeared to have exceeded 10 feet include the Abraham Lincoln Memorial Bridge at Blair, Nebr., Bellevue Bridge at Bellevue, Nebr., and Nebraska City Bridge at Nebraska City, Nebr. Hydrographic surveys at 14 of the 15 sites were completed in mid-July and again in early October or late-November 2011. Near three of the bridges, the bed elevation of locations surveyed in July increased by more than 10 feet, on average, by late October or early November 2011. Bed elevations increased between 1 and 10 feet, on average, near six bridges. Near the remaining four bridges, bed elevations decreased between 1 and 4 feet, on average, from July to late October or early November.

  1. Catalytic oxidation of water and alcohols by a robust iron(iii) complex bearing a cross-bridged cyclam ligand.

    PubMed

    Tan, Peng; Kwong, Hoi-Ki; Lau, Tai-Chu

    2015-08-01

    An iron(iii) complex bearing a cross-bridged cyclam ligand (4,11-dimethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane) is an efficient catalyst for the oxidation of both water and alcohols using sodium periodate as the oxidant. In catalytic water oxidation a maximum turnover number (TON) of 1030 is achieved, while in catalytic alcohol oxidation >95% conversions and yields can be obtained. PMID:26126521

  2. Calcium sensitivity of the cross-bridge cycle of Myo1c, the adaptation motor in the inner ear

    PubMed Central

    Adamek, Nancy; Coluccio, Lynne M.; Geeves, Michael A.

    2008-01-01

    The class I myosin Myo1c is a mediator of adaptation of mechanoelectrical transduction in the stereocilia of the inner ear. Adaptation, which is strongly affected by Ca2+, permits hair cells under prolonged stimuli to remain sensitive to new stimuli. Using a Myo1c fragment (motor domain and one IQ domain with associated calmodulin), with biochemical and kinetic properties similar to those of the native molecule, we have performed a thorough analysis of the biochemical cross-bridge cycle. We show that, although the steady-state ATPase activity shows little calcium sensitivity, individual molecular events of the cross-bridge cycle are calcium-sensitive. Of significance is a 7-fold inhibition of the ATP hydrolysis step and a 10-fold acceleration of ADP release in calcium. These changes result in an acceleration of detachment of the cross-bridge and a lengthening of the lifetime of the detached M–ATP state. These data support a model in which slipping adaptation, which reduces tip-link tension and allows the transduction channels to close after an excitatory stimulus, is mediated by Myo1c and modulated by the calcium transient. PMID:18391215

  3. Altered cross-bridge characteristics following haemodynamic overload in rabbit hearts expressing V3 myosin.

    PubMed

    Peterson, J N; Nassar, R; Anderson, P A; Alpert, N R

    2001-10-15

    1. Our goal in this study was to evaluate the effect of haemodynamic overload on cross-bridge (XBr) kinetics in the rabbit heart independently of myosin heavy chain (MHC) isoforms, which are known to modulate kinetics in small mammals. We applied a myothermal-mechanical protocol to isometrically contracting papillary muscles from two rabbit heart populations: (1) surgically induced right ventricular pressure overload (PO), and (2) sustained treatment with propylthiouracil (PTU). Both treatments resulted in a 100 % V3 MHC profile. 2. XBr force-time integral (FTI), evaluated during the peak of the twitch from muscle FTI and tension-dependent heat, was greater in the PO hearts (0.80 +/- 0.10 versus 0.45 +/- 0.05 pN s, means +/- S.E.M., P = 0.01). 3. Within the framework of a two-state XBr model, the PO XBr developed more force while attached (5.8 +/- 0.9 versus 2.7 +/- 0.3 pN), with a lower cycling rate (0.89 +/- 0.10 versus 1.50 +/- 0.14 s(-1)) and duty cycle (0.14 +/- 0.03 versus 0.24 +/- 0.02). 4. Only the ventricular isoforms of myosin light chain 1 and 2 and cardiac troponin I (cTnI) were expressed, with no difference in cTnI phosphorylation between the PO and PTU samples. The troponin T (TnT) isoform compositions in the PO and PTU samples were significantly different (P = 0.001), with TnT2 comprising 2.29 +/- 0.03 % in PO hearts versus 0.98 +/- 0.01 % in PTU hearts of total TnT. 5. This study demonstrates that MHC does not mediate dramatic alterations in XBr function induced by haemodynamic overload. Our findings support the likelihood that differences among other thick and thin filament proteins underlie these XBr alterations. PMID:11600690

  4. Rhamnogalacturonan-II cross-linking of plant pectins via boron bridges occurs during polysaccharide synthesis and/or secretion

    PubMed Central

    Chormova, Dimitra; Messenger, David J; Fry, Stephen C

    2014-01-01

    Rhamnogalacturonan-II (RG-II), a domain of plant cell wall pectins, is able to cross-link with other RG-II domains through borate diester bridges. Although it is known to affect mechanical properties of the cell wall, the biochemical requirements and lifecycle of this cross-linking remain unclear. We developed a PAGE methodology to allow separation of monomeric and dimeric RG-II and used this to study the dynamics of cross-linking in vitro and in vivo. Rosa cells grown in medium with no added boron contained no RG-II dimers, although these re-appeared after addition of boron to the medium. However, other Rosa cultures which were unable to synthesize new polysaccharides did not show dimer formation. We conclude that RG-II normally becomes cross-linked intraprotoplasmically or during secretion, but not post-secretion. PMID:24603547

  5. Sign Languages: Contribution to Neurolinguistics from Cross-Modal Research

    PubMed Central

    Malaia, Evie; Wilbur, Ronnie

    2010-01-01

    Using sign language research as an example, we argue that both the cross-linguistic descriptive approach to data, advocated by Evans and Levinson (2009), as well as abstract (‘formal’) analyses are necessary steps towards the development of “neurolinguistic primitives” for investigating how human languages are instantiated in the brain. PMID:20953339

  6. Effect of Ca2+ on weak cross-bridge interaction with actin in the presence of adenosine 5'-[gamma-thio]triphosphate).

    PubMed Central

    Kraft, T; Yu, L C; Kuhn, H J; Brenner, B

    1992-01-01

    In the presence of the nucleotide analog adenosine 5'-[gamma-thio]triphosphate (ATP[gamma S]), effects of Ca2+ on stiffness and equatorial x-ray diffraction patterns of single skinned fibers of the rabbit psoas muscle were studied. It is shown that cross-bridges in the presence of ATP[gamma S] have properties of the weak-binding states of the ATP hydrolysis cycle. Raising the Ca2+ concentration up to pCa 4.5 has little effect on actin affinity of cross-bridges in the presence of ATP[gamma S]. However, the rate constants for cross-bridge dissociation and reassociation from and to actin are reduced by about 2 orders of magnitude. In addition, nucleotide affinity of the cross-bridge is much smaller at high Ca2+ concentrations. Implications for interpretation of fiber stiffness recorded during isotonic shortening and the rising phase of a tetanus are discussed. PMID:1454820

  7. Level II scour analysis for Bridge 9 (BARRUSO3020009) on U.S. Route 302, crossing Jail Branch, Barre, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Ivanoff, Michael A.

    1997-01-01

    skew-to-roadway. There is evidence of channel scour along the right bank from 190 feet upstream of the bridge and extending through the bridge along the right abutment. Under the bridge, the scour depth is approximately 0.5 feet below the mean thalweg depth. Scour protection measures at the site include type-3 stone fill (less than 48 inches diameter) along the right bank extending from the bridge to 192 feet upstream. Type-2 stone fill (less than 36 inches diameter) is along the right abutment and the right downstream bank to 205 feet downtream of the bridge. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0.2 to 0.5 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.3 to 7.5 ft. The worst-case abutment scour occurred at the 500-year discharge. Computed scour for the 100-year event does not go below the abutment footings. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a

  8. A cross-bridge based model of force depression: Can a single modification address both transient and steady-state behaviors?

    PubMed

    Corr, David T; Herzog, Walter

    2016-03-21

    Force depression (FD), the reduction of isometric force following active shortening, is a phenomenon of skeletal muscle that has received significant attention in biomechanical and physiological literature, yet the mechanisms underlying FD remain unknown. Recent experiments identified a slower rate of force redevelopment with increasing amounts of steady-state FD, suggesting that FD may be caused, at least in part, by a decrease in cross-bridge binding rate (Corr and Herzog, 2005; Koppes et al., 2014). Herein, we develop a cross-bridge based model of FD in which the binding rate function, f, decreases with the mechanical work performed during shortening. This modification incorporates a direct relationship between steady-state FD and muscle mechanical work (Corr and Herzog, 2005; Herzog et al., 2000; Kosterina et al., 2008), and is consistent with a proposed mechanism attributing FD to stress-induced inhibition of cross-bridge attachments (Herzog, 1998; Maréchal and Plaghki, 1979). Thus, for an increase in mechanical work, the model should predict a slower force redevelopment (decreased attachment rate) to a more depressed steady-state force (fewer attached cross-bridges), and a reduction in contractile element stiffness (Ford et al., 1981). We hypothesized that since this modification affects the cross-bridge kinetics, a corresponding model would be able to account for both transient and steady-state FD behaviors. Comparisons to prior experiments (Corr and Herzog, 2005; Herzog et al., 2000; Kosterina et al., 2008) show that both steady-state and transient aspects of FD, as well as the relationship of FD with respect to speed and amplitude of shortening, are well captured by this model. Thus, this relatively simple cross-bridge based model of FD lends support to a mechanism involving the inhibition of cross-bridge binding, and indicates that cross-bridge kinetics may play a critical role in FD. PMID:26928777

  9. Altered cross-bridge characteristics following haemodynamic overload in rabbit hearts expressing V3 myosin

    PubMed Central

    Peterson, Jon N; Nassar, Rashid; Anderson, Page A W; Alpert, Norman R

    2001-01-01

    Our goal in this study was to evaluate the effect of haemodynamic overload on cross-bridge (XBr) kinetics in the rabbit heart independently of myosin heavy chain (MHC) isoforms, which are known to modulate kinetics in small mammals. We applied a myothermal-mechanical protocol to isometrically contracting papillary muscles from two rabbit heart populations: (1) surgically induced right ventricular pressure overload (PO), and (2) sustained treatment with propylthiouracil (PTU). Both treatments resulted in a 100 % V3 MHC profile.XBr force–time integral (FTI), evaluated during the peak of the twitch from muscle FTI and tension-dependent heat, was greater in the PO hearts (0.80 ± 0.10 versus 0.45 ± 0.05 pN s, means ±s.e.m.., P = 0.01).Within the framework of a two-state XBr model, the PO XBr developed more force while attached (5.8 ± 0.9 versus 2.7 ± 0.3 pN), with a lower cycling rate (0.89 ± 0.10 versus 1.50 ± 0.14 s−1) and duty cycle (0.14 ± 0.03 versus 0.24 ± 0.02).Only the ventricular isoforms of myosin light chain 1 and 2 and cardiac troponin I (cTnI) were expressed, with no difference in cTnI phosphorylation between the PO and PTU samples. The troponin T (TnT) isoform compositions in the PO and PTU samples were significantly different (P = 0.001), with TnT2 comprising 2.29 ± 0.03 % in PO hearts versus 0.98 ± 0.01 % in PTU hearts of total TnT.This study demonstrates that MHC does not mediate dramatic alterations in XBr function induced by haemodynamic overload. Our findings support the likelihood that differences among other thick and thin filament proteins underlie these XBr alterations. PMID:11600690

  10. Level II scour analysis for Bridge 37, (BRNETH00740037) on Town Highway 74, crossing South Peacham Brook, Barnet, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Severance, Timothy

    1997-01-01

    Contraction scour for all modelled flows ranged from 15.8 to 22.5 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.7 to 11.1 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in Tables 1 and 2. A cross-section of the scour computed at the bridge is prese

  11. Level II scour analysis for Bridge 39 (PEACTH00620039) on Town Highway 62, crossing South Peacham Brook, Peacham, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Degnan, James R.

    1997-01-01

    Contraction scour for all modelled flows ranged from 1.0 to 1.6 ft. The worst-case contraction scour occurred at the 100-year discharge. Abutment scour ranged from 5.9 to 7.4 ft. The worst-case abutment scour occurred at the incipient roadway-overtopping discharge, which is less than the 100-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scouredstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in f

  12. Level II scour analysis for bridge 2 (WODFTH00010002) on Town Highway 1, crossing Hell Hollow Brook, Woodford, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Degnan, James R.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure WODFTH00010002 on Town Highway 1 crossing Hell Hollow Brook, Woodford, Vermont (figures 1-8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (FHWA, 1993). Results of a Level I scour investigation also are included in appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in appendix D.

  13. Bridge Building Potential in Cross-Cultural Learning: A Mixed Method Study

    ERIC Educational Resources Information Center

    Rienties, Bart; Johan, Novie; Jindal-Snape, Divya

    2015-01-01

    Although many international students experience transitional issues, most research assumes that these issues will disappear over time with increased interaction. Using principles of social network theory, this study addressed why some students become bridge builders between international and host students, while others primarily interact with…

  14. Bridging Refugee Youth and Children's Services: A Case Study of Cross-Service Training

    ERIC Educational Resources Information Center

    Morland, Lyn; Duncan, Julianne; Hoebing, Joyce; Kirschke, Juanita; Schmidt, Laura

    2005-01-01

    Bridging Refugee Youth and Children's Services (BRYCS), a public-private partnership between the federal Office of Refugee Resettlement, Lutheran Immigration and Refugee Service, and the United States Conference of Catholic Bishops, provides national technical assistance to public child welfare. After a series of "community conversations," BRYCS…

  15. Crossing the Bridge: GED Credentials and Postsecondary Educational Outcomes. Year One Report

    ERIC Educational Resources Information Center

    Patterson, Margaret Becker; Zhang, Jizhi; Song, Wei; Guison-Dowdy, Anne

    2010-01-01

    For most high school non-completers, the GED[R] credential provides a bridge to postsecondary education, but little is known about how successfully GED (General Educational Development) Test candidates make that transition and whether enrollment rates change with time. The American Council on Education (ACE) has begun a three-year longitudinal…

  16. trans-Methylpyridine cyclen versus cross-bridged trans-methylpyridine cyclen. Synthesis, acid-base and metal complexation studies (metal = Co2+, Cu2+, and Zn2+).

    PubMed

    Bernier, Nicolas; Costa, Judite; Delgado, Rita; Félix, Vítor; Royal, Guy; Tripier, Raphaël

    2011-05-01

    The synthesis of the cross-bridged cyclen CRpy(2) {4,10-bis((pyridin-2-yl)methyl)-1,4,7,10-tetraazabicyclo[5.5.2]tetradecane}, a constrained analogue of the previously described trans-methylpyridine cyclen Cpy(2) is reported. The additional ethylene bridge confers to CRpy(2) proton-sponge type behaviour which was explored by NMR and potentiometric studies. Transition metal complexes have been synthesized (by complexation of both ligands with Co(2+), Cu(2+) and Zn(2+)) and characterized in solution and in the solid state. The single crystal X-ray structures of [CoCpy(2)](2+), [CuCpy(2)](2+) and [ZnCpy(2)](2+) complexes were determined. Stability constants of the complexes, including those of the cross-bridged derivative, were determined using potentiometric titration data and the kinetic inertness of the [CuCRpy(2)](2+) complex in an acidic medium (half-life values) was evaluated by spectrophotometry. The pre-organized structure of the cross-bridged ligand imposes an additional strain for the complexation leading to complexes with smaller thermodynamic stability in comparison with the related non-bridged ligand. The electrochemical study involving cyclic voltammetry underlines the importance of the ethylene cross-bridge on the redox properties of the transition metal complexes. PMID:21409259

  17. Bridging Informatics and Earth Science: a Look at Gregory Leptoukh's Contributions

    NASA Astrophysics Data System (ADS)

    Lynnes, C.

    2012-12-01

    With the tragic passing this year of Gregory Leptoukh, the Earth and Space Sciences community lost a tireless participant in--and advocate for--science informatics. Throughout his career at NASA, Dr. Leptoukh established a theme of bridging the gulf between the informatics and science communities. Nowhere is this more evident than his leadership in the development of Giovanni (GES DISC Interactive Online Visualization ANd aNalysis Infrastructure). Giovanni is an online tool that serves to hide the often-complex technical details of data format and structure, making science data easier to explore and use by Earth scientists. To date Giovanni has been acknowledged as a contributor in 500-odd scientific articles. In recent years, Leptoukh concentrated his efforts on multi-sensor data inter-comparison, merging and fusion. This work exposed several challenges at the intersection of data and science. One of these was the ease with which a naive user might generate spurious comparisons, a potential hazard that was the genesis of the Multi-sensor Data Synergy Advisor (MDSA). The MDSA uses semantic ontologies and inference rules to organize knowledge about dataset quality and other salient characteristics in order to advise users on potential caveats for comparing or merging two datasets. Recently, Leptoukh also led the development of AeroStat, an online Giovanni instance to investigate aerosols via statistics from station and satellite comparisons and merged maps of data from more than one instrument. Aerostat offers a neural net based bias adjustment to "harmonize" the data by removing systematic offsets between datasets before merging. These examples exhibit Leptoukh's talent for adopting advanced computer technologies in the service of making science data more accessible to researchers. In this, he set an example that is at once both vital and challenging for the ESSI community to emulate.

  18. Bridging Informatics and Earth Science: a Look at Gregory Leptoukh's Contributions

    NASA Technical Reports Server (NTRS)

    2012-01-01

    With the tragic passing this year of Gregory Leptoukh, the Earth and Space Sciences community lost a tireless participant in--and advocate for--science informatics. Throughout his career at NASA, Dr. Leptoukh established a theme of bridging the gulf between the informatics and science communities. Nowhere is this more evident than his leadership in the development of Giovanni (GES DISC Interactive Online Visualization ANd aNalysis Infrastructure). Giovanni is an online tool that serves to hide the often-complex technical details of data format and structure, making science data easier to explore and use by Earth scientists. To date Giovanni has been acknowledged as a contributor in 500-odd scientific articles. In recent years, Leptoukh concentrated his efforts on multi-sensor data inter-comparison, merging and fusion. This work exposed several challenges at the intersection of data and science. One of these was the ease with which a naive user might generate spurious comparisons, a potential hazard that was the genesis of the Multi-sensor Data Synergy Advisor (MDSA). The MDSA uses semantic ontologies and inference rules to organize knowledge about dataset quality and other salient characteristics in order to advise users on potential caveats for comparing or merging two datasets. Recently, Leptoukh also led the development of AeroStat, an online Giovanni instance to investigate aerosols via statistics from station and satellite comparisons and merged maps of data from more than one instrument. Aerostat offers a neural net based bias adjustment to harmonize the data by removing systematic offsets between datasets before merging. These examples exhibit Leptoukh's talent for adopting advanced computer technologies in the service of making science data more accessible to researchers. In this, he set an example that is at once both vital and challenging for the ESSI community to emulate.

  19. Regulation of the glycophorin C-protein 4.1 membrane-to-skeleton bridge and evaluation of its contribution to erythrocyte membrane stability.

    PubMed

    Chang, S H; Low, P S

    2001-06-22

    The band 3-ankyrin-spectrin bridge and the glycophorin C-protein 4.1-spectrin/actin bridge constitute the two major tethers between the erythrocyte membrane and its spectrin skeleton. Although a structural requirement for the band 3-ankyrin bridge is well established, the contribution of the glycophorin C-protein 4.1 bridge to red cell function remains to be defined. In order to explore this latter bridge further, we have identified and/or characterized five stimuli that sever the linkage in intact erythrocytes and have examined the impact of this rupture on membrane mechanical properties. We report here that elevation of cytosolic 2,3-bisphosphoglycerate, an increase in intracellular Ca(2+), removal of cell O(2), a decrease in intracellular pH, and activation of erythrocyte protein kinase C all promote dissociation of protein 4.1 from glycophorin C, leading to reduced retention of glycophorin C in detergent-extracted spectrin/actin skeletons. Significantly, where mechanical studies could be performed, we also observe that rupture of the membrane-to-skeleton bridge has little or no impact on the mechanical properties of the cell, as assayed by ektacytometry and nickel mesh filtration. We, therefore, suggest that, although regulation of the glycophorin C-protein 4.1-spectrin/actin bridge likely occurs physiologically, the role of the tether and the associated regulatory changes remain to be established. PMID:11294862

  20. Breakage-fusion-bridge Cycles and Large Insertions Contribute to the Rapid Evolution of Accessory Chromosomes in a Fungal Pathogen

    PubMed Central

    Croll, Daniel; Zala, Marcello; McDonald, Bruce A.

    2013-01-01

    Chromosomal rearrangements are a major driver of eukaryotic genome evolution, affecting speciation, pathogenicity and cancer progression. Changes in chromosome structure are often initiated by mis-repair of double-strand breaks in the DNA. Mis-repair is particularly likely when telomeres are lost or when dispersed repeats misalign during crossing-over. Fungi carry highly polymorphic chromosomal complements showing substantial variation in chromosome length and number. The mechanisms driving chromosome polymorphism in fungi are poorly understood. We aimed to identify mechanisms of chromosomal rearrangements in the fungal wheat pathogen Zymoseptoria tritici. We combined population genomic resequencing and chromosomal segment PCR assays with electrophoretic karyotyping and resequencing of parents and offspring from experimental crosses to show that this pathogen harbors a highly diverse complement of accessory chromosomes that exhibits strong global geographic differentiation in numbers and lengths of chromosomes. Homologous chromosomes carried highly differentiated gene contents due to numerous insertions and deletions. The largest accessory chromosome recently doubled in length through insertions totaling 380 kb. Based on comparative genomics, we identified the precise breakpoint locations of these insertions. Nondisjunction during meiosis led to chromosome losses in progeny of three different crosses. We showed that a new accessory chromosome emerged in two viable offspring through a fusion between sister chromatids. Such chromosome fusion is likely to initiate a breakage-fusion-bridge (BFB) cycle that can rapidly degenerate chromosomal structure. We suggest that the accessory chromosomes of Z. tritici originated mainly from ancient core chromosomes through a degeneration process that included BFB cycles, nondisjunction and mutational decay of duplicated sequences. The rapidly evolving accessory chromosome complement may serve as a cradle for adaptive evolution in

  1. Air toxics exposure from vehicle emissions at a U.S. border crossing: Buffalo Peace Bridge Study.

    PubMed

    Spengler, John; Lwebuga-Mukasa, Jamson; Vallarino, Jose; Melly, Steve; Chillrud, Steve; Baker, Joel; Minegishi, Taeko

    2011-07-01

    The Peace Bridge in Buffalo, New York, which spans the Niagara River at the east end of Lake Erie, is one of the busiest U.S. border crossings. The Peace Bridge plaza on the U.S. side is a complex of roads, customs inspection areas, passport control areas, and duty-free shops. On average 5000 heavy-duty diesel trucks and 20,000 passenger cars traverse the border daily, making the plaza area a potential "hot spot" for emissions from mobile sources. In a series of winter and summer field campaigns, we measured air pollutants, including many compounds considered by the U.S. Environmental Protection Agency (EPA*) as mobile-source air toxics (MSATs), at three fixed sampling sites: on the shore of Lake Erie, approximately 500 m upwind (under predominant wind conditions) of the Peace Bridge plaza; immediately downwind of (adjacent to) the plaza; and 500 m farther downwind, into the community of west Buffalo. Pollutants sampled were particulate matter (PM) < or = 10 microm (PM10) and < or = 2.5 microm (PM2.5) in aerodynamic diameter, elemental carbon (EC), 28 elements, 25 volatile organic compounds (VOCs) including 3 carbonyls, 52 polycyclic aromatic hydrocarbons (PAHs), and 29 nitrogenated polycyclic aromatic hydrocarbons (NPAHs). Spatial patterns of counts of ultrafine particles (UFPs, particles < 0.1 microm in aerodynamic diameter) and of particle-bound PAH (pPAH) concentrations were assessed by mobile monitoring in the neighborhood adjacent to the Peace Bridge plaza using portable instruments and Global Positioning System (GPS) tracking. The study was designed to assess differences in upwind and downwind concentrations of MSATs, in areas near the Peace Bridge plaza on the U.S. side of the border. The Buffalo Peace Bridge Study featured good access to monitoring locations proximate to the plaza and in the community, which are downwind with the dominant winds from the direction of Lake Erie and southern Ontario. Samples from the lakeside Great Lakes Center (GLC), which

  2. Level II scour analysis for Bridge 2 (RYEGTH00020002) on Town Highway 2, crossing the Wells River, Ryegate, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure RYEGTH00020002 on Town Highway 2 crossing the Wells River, Ryegate, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in east-central Vermont. The 75.7-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover consists of cut grass, trees, and brush on the flood plains while the immediate banks have dense woody vegetation. In the study area, the Wells River has an incised, sinuous channel with a slope of approximately 0.006 ft/ft, an average channel top width of 110 ft and an average bank height of 12 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 82.3 mm (0.270 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 24, 1995, indicated that the reach was laterally unstable with moderate fluvial erosion and meandering downstream of the bridge. The Town Highway 2 crossing of the Wells River is a 79-ft-long, two-lane bridge consisting of one 75-foot steel-beam span (Vermont Agency of Transportation, written communication, March 27, 1995). The opening length of the structure parallel to the bridge face is 75.1 ft. The bridge is supported by vertical, concrete abutments, the left has a spill-through embankment, with wingwalls. The channel is not skewed

  3. Level II scour analysis for Bridge 24 (MANCUS00070024) on U.S. Route 7, crossing Lye Brook, Manchester, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure MANCUS00070024 on U.S. Route 7 crossing Lye Brook, Manchester, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Taconic section of the New England physiographic province in southwestern Vermont. The 8.13-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the primary surface cover consists of brush and trees. In the study area, Lye Brook has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 66 ft and an average bank height of 11 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 90.0 mm (0.295 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 6, 1996, indicated that the reach was stable. Although, the immediate reach is considered stable, upstream of the bridge the Lye Brook valley is very steep (0.05 ft/ft). Extreme events in a valley this steep may quickly reveal the instability of the channel. In the Flood Insurance Study for the Town of Manchester (Federal Emergency Management Agency, January, 1985), Lye Brook’s overbanks were described as “boulder strewn” after the August 1976 flood. The U.S. Route 7 crossing of Lye Brook is a 28-ft-long, two-lane bridge consisting of one 25-foot concrete span (Vermont Agency of Transportation, written communication, September

  4. X-ray diffraction indicates that active cross-bridges bind to actin target zones in insect flight muscle.

    PubMed

    Tregear, R T; Edwards, R J; Irving, T C; Poole, K J; Reedy, M C; Schmitz, H; Towns-Andrews, E; Reedy, M K

    1998-03-01

    We report the first time-resolved study of the two-dimensional x-ray diffraction pattern during active contraction in insect flight muscle (IFM). Activation of demembranated Lethocerus IFM was triggered by 1.5-2.5% step stretches (risetime 10 ms; held for 1.5 s) giving delayed active tension that peaked at 100-200 ms. Bundles of 8-12 fibers were stretch-activated on SRS synchrotron x-ray beamline 16.1, and time-resolved changes in diffraction were monitored with a SRS 2-D multiwire detector. As active tension rose, the 14.5- and 7.2-nm meridionals fell, the first row line dropped at the 38.7 nm layer line while gaining a new peak at 19.3 nm, and three outer peaks on the 38.7-nm layer line rose. The first row line changes suggest restricted binding of active myosin heads to the helically preferred region in each actin target zone, where, in rigor, two-headed lead bridges bind, midway between troponin bulges that repeat every 38.7 nm. Halving this troponin repeat by binding of single active heads explains the intensity rise at 19.3 nm being coupled to a loss at 38.7 nm. The meridional changes signal movement of at least 30% of all myosin heads away from their axially ordered positions on the myosin helix. The 38.7- and 19.3-nm layer line changes signal stereoselective attachment of 7-23% of the myosin heads to the actin helix, although with too little ordering at 6-nm resolution to affect the 5.9-nm actin layer line. We conclude that stretch-activated tension of IFM is produced by cross-bridges that bind to rigor's lead-bridge target zones, comprising < or = 1/3 of the 75-80% that attach in rigor. PMID:9512040

  5. Level II scour analysis for Bridge 7 (WALDTH00020007) on Town Highway 2, crossing Coles Brook, Walden, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Medalie, Laura

    1997-01-01

    ft, an average channel top width of 37 ft and an average bank height of 4 ft. The channel bed material ranges from sand to cobble with a median grain size (D50) of 32.9 mm (0.108 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 9, 1995, indicated that the reach was laterally unstable due to cut-banks, point bars, and loose unconsolidated bed material. The Town Highway 2 crossing of Coles Brook is a 74-ft-long, two-lane bridge consisting of one 71-foot steel-beam span (Vermont Agency of Transportation, written communication, April 5, 1995). The opening length of the structure parallel to the bridge face is 69.3 ft. The bridge is supported by spill-through abutments. The channel is skewed approximately 35 degrees to the opening while the measured opening-skew-to-roadway is 15 degrees. A scour hole 1.5 ft deeper than the mean thalweg depth was observed from 60 ft. to 100 ft. downstream during the Level I assessment. Scour protection measures at the site include: type-1 stone fill (less than 12 inches diameter) along the right bank upstream, at the downstream end of the downstream left wingwall and downstream right wingwall; and type-2 stone fill (less than 36 inches diameter) along the left bank upstream, at the upstream end of the upstream right wingwall, and along the entire base of the left and right abutments. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are

  6. Safer Bridges

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Safer bridges are among a number of spinoff benefits from NASA procedures for testing 'cfracture toughness" of a structural part, meaning its ability to -siscracktsh at might cause failure. The New River Bridge in West Virginia, shown under construction, is the world's largest single span bridge. U.S. Steel fracture toughness requirements for such bridges include NASA-developed test procedures. Bridge materials and other metal structures may develop flaws during their service lifetimes. Such flaws can affect the structural integrity of the part. Thus, it is important to know the "fracture toughness" of a structural part, or its ability to resist cracks. NASA has long experience in developing fracture toughness tests for aerospace hardware. Since 1960, NASA-Lewis has worked closely with the American Society for Testing & Materials. Lewis and NASA-funded industrial contractors have made many important contributions to test procedures, now recommended by ASTM, for measuring fracture toughness.

  7. Radar-based dynamic testing of the cable-suspended bridge crossing the Ebro River at Amposta, Spain

    SciTech Connect

    Gentile, Carmelo; Luzi, Guido

    2014-05-27

    Microwave remote sensing is the most recent experimental methodology suitable to the non-contact measurement of deflections on large structures, in static or dynamic conditions. After a brief description of the radar measurement system, the paper addresses the application of microwave remote sensing to ambient vibration testing of a cable-suspended bridge. The investigated bridge crosses the Ebro River at Amposta, Spain and consists of two steel stiffening trusses and a series of equally spaced steel floor beams; the main span is supported by inclined stay cables and two series of 8 suspension cables. The dynamic tests were performed in operational conditions, with the sensor being placed in two different positions so that the response of both the steel deck and the arrays of suspension elements was measured. The experimental investigation confirms the simplicity of use of the radar and the accuracy of the results provided by the microwave remote sensing as well as the issues often met in the clear localization of measurement points.

  8. Level II scour analysis for Bridge 38 (BETHTH00070038) on Town Highway 007, crossing Gilead Brook, Bethel, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Song, Donald L.

    1996-01-01

    The town highway 5 crossing of the Black River is a 70-ft-long, two-lane bridge consisting of one 65-foot clear span (Vermont Agency of Transportation, written commun., August 2, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. There is also a retaining wall along the upstream side of the road embankments. The channel is skewed approximately 20 degrees to the opening while the opening-skew-to-roadway is 15 degrees. A scour hole 3.0 ft deeper than the mean thalweg depth was observed along the right abutment. The scour hole was 27 feet long, 15 feet wide, and was 2.5 feet below the abutment footing at the time of the Level I assessment. This right abutment had numerous cracks and had settled. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. The scour analysis results are presented in tables 1 and 2 and a graph of the scour depths is presented in figure 8.

  9. Radar-based dynamic testing of the cable-suspended bridge crossing the Ebro River at Amposta, Spain

    NASA Astrophysics Data System (ADS)

    Gentile, Carmelo; Luzi, Guido

    2014-05-01

    Microwave remote sensing is the most recent experimental methodology suitable to the non-contact measurement of deflections on large structures, in static or dynamic conditions. After a brief description of the radar measurement system, the paper addresses the application of microwave remote sensing to ambient vibration testing of a cable-suspended bridge. The investigated bridge crosses the Ebro River at Amposta, Spain and consists of two steel stiffening trusses and a series of equally spaced steel floor beams; the main span is supported by inclined stay cables and two series of 8 suspension cables. The dynamic tests were performed in operational conditions, with the sensor being placed in two different positions so that the response of both the steel deck and the arrays of suspension elements was measured. The experimental investigation confirms the simplicity of use of the radar and the accuracy of the results provided by the microwave remote sensing as well as the issues often met in the clear localization of measurement points.

  10. Level II scour analysis for Bridge 17 (SHEFTH00380017) on Town Highway 38, crossing Miller Run, Sheffield, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Degnan, James R.

    1997-01-01

    Contraction scour for modelled flows ranged from 0.0 to 2.4 ft. Abutment scour ranged from 6.1 to 7.9 ft at the left abutment and 11.4 to 17.4 ft at the right abutment. The worstcase contraction and abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stabi

  11. Level II scour analysis for Bridge 46 (BRNETH00610046) on Town Highway 61, crossing East Peacham Brook, Barnet, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0 to 1.2 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 10.4 to 13.9 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usual

  12. Level II scour analysis for Bridge 16 (BRNATH00800016) on Town Highway 80, crossing Locust Creek, Barnard, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Weber, Matthew A.

    1996-01-01

    Additional details describing conditions at the site are included in the Level II Summary, Appendix D, and Appendix E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0.0 to 3.7 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge, which was between the 100- and 500-year discharge. Abutment scour ranged from 17.5 to 23.2 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented

  13. Level II scour analysis for Bridge 4 (CRAFTH00040004) on Town Highway 4, crossing Whitney Brook, Craftsbury, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Hammond, Robert E.

    1996-01-01

    Total scour at a highway crossing is comprised of three components: 1) long-term degradation; 2) contraction scour (due to accelerated flow caused by reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the computed scour results follow. Contraction scour for all modelled flows ranged from 0.7 to 1.7 feet. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 10.7 to 15.3 feet. The worst-case abutment scour also occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  14. Level II scour analysis for Bridge 12 (BRAITH00230012) on Town Highway 23, crossing Ayers Brook, Braintree, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 4.2 to 9.4 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge which was less than the 100-year discharge. Abutment scour ranged from 4.3 to 17.5 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  15. Level II scour analysis for Bridge 13 (SHARTH00040013) on Town Highway 4, crossing Broad Brook, Sharon, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Weber, Matthew A.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure SHARTH00040013 on Town Highway 4 crossing Broad Brook, Sharon, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in central Vermont. The 16.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is brushland on the downstream left overbank and row crops on the right overbank, while the immediate banks have dense woody vegetation. Upstream of the bridge, the overbanks are forested. In the study area, Broad Brook has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 69 ft and an average bank height of 5 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 112 mm (0.369 ft). The geomorphic assessment at the time of the Level I site visit on April 11, 1995 and Level II site visit on July 23, 1996, indicated that the reach was stable. The Town Highway 4 crossing of Broad Brook is a 34-ft-long, two-lane bridge consisting of one 31-foot concrete tee beam span (Vermont Agency of Transportation, written communication, March 23, 1995). The opening length of the structure parallel to the bridge face is 30.1 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening

  16. Level II scour analysis for Bridge 26 (ROYATH00540026) on Town Highway 54, crossing Broad Brook, Royalton, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Weber, Matthew A.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ROYATH00540026 on Town Highway 54 crossing Broad Brook, Royalton, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in central Vermont. The 11.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover on the left bank upstream and downstream is pasture with trees and brush on the immediate banks. The right bank, upstream and downstream of the bridge, is forested. In the study area, Broad Brook has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 37 ft and an average bank height of 4 ft. The channel bed material ranges from sand to boulders with a median grain size (D50) of 66.3 mm (0.218 ft). The geomorphic assessment at the time of the Level I site visit on April 13, 1995 and the Level II site visit on July 11, 1996, indicated that the reach was stable. The Town Highway 54 crossing of Broad Brook is a 29-ft-long, one-lane bridge consisting of one 24-foot steel-beam span with a timber deck (Vermont Agency of Transportation, written communication, March 23, 1995). The opening length of the structure parallel to the bridge face is 23.3 ft. The bridge is supported by a vertical, concrete face laid-up stone abutment with concrete wingwalls on the left and a laid-up stone

  17. Level II scour analysis for Bridge 68 (NFIETH00960068) on Town Highway 96, crossing the Dog River, Northfield, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure NFIETH00960068 on Town Highway 96 crossing the Dog River, Northfield, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province in central Vermont. The 30.7-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover on the left bank upstream and downstream is pasture while the immediate banks have dense woody vegetation. The right bank upstream is forested and the downstream right bank is pasture. Vermont state route 12A runs parallel to the river on the right bank. In the study area, the Dog River has an incised, straight channel with a slope of approximately 0.004 ft/ft, an average channel top width of 70 ft and an average bank height of 7 ft. The channel bed material ranges from sand to cobble with a median grain size (D50) of 47.9 mm (0.157 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 25, 1996, indicated that the reach was stable. The Town Highway 96 crossing of the Dog River is a 45-ft-long, one-lane bridge consisting of one 43-foot steel-beam span with a timber deck (Vermont Agency of Transportation, written communication, October 13, 1995). The opening length of the structure parallel to the bridge face is 41.5 ft.The bridge is supported by vertical, concrete abutments with wingwalls. The

  18. Level II scour analysis for Bridge 13 (PFRDTH00030013) on Town Highway 3, crossing Furnace Brook, Pittsford, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Medalie, Laura

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure PFRDTH00030013 on Town Highway 3 crossing Furnace Brook, Pittsford, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Taconic section of the New England physiographic province in western Vermont. The 17.1-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is grass along the downstream right bank while the remaining banks are primarily forested. In the study area, Furnace Brook has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 49 ft and an average channel depth of 4 ft. The predominant channel bed material ranges from gravel to bedrock with a median grain size (D50) of 70.2 mm (0.230 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 20, 1995, indicated that the reach was stable. The Town Highway 3 crossing of Furnace Brook is a 75-ft-long, two-lane bridge consisting of one 72-ft-long steel stringer span (Vermont Agency of Transportation, written communication, March 14, 1995). The bridge is supported by vertical, concrete abutments with spill-through slopes. The channel is skewed approximately 20 degrees to the opening while the opening-skew-to-roadway is 35 degrees. The opening-skew-to-roadway was determined from surveyed data collected at the bridge although, information provided from the

  19. Level II scour analysis for Bridge 43 (CHELTH00460043) on Town Highway 46, crossing Jail Brook, Chelsea, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure CHELTH00460043 on Town Highway 46 crossing Jail Brook, Chelsea, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in central Vermont. The 4.68-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is best described as suburban with homes, lawns, and a few trees. In the study area, Jail Brook has an incised, straight channel with a slope of approximately 0.02 ft/ft, an average channel top width of 32 ft and an average bank height of 6 ft. The channel bed material ranges from coarse sand to boulder with a median grain size (D50) of 43.0 mm (0.141 ft). The geomorphic assessment at the time of the Level I and Level II site visit on November 18, 1994, indicated that the reach was stable. The Town Highway 46 crossing of Jail Brook is a 27-ft-long, two-lane bridge consisting of one 23-foot concrete span (Vermont Agency of Transportation, written communication, August 25, 1994). The opening length of the structure parallel to the bridge face is 22.8 ft.The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately zero degrees to the opening and the opening-skew-to-roadway is also zero degrees. Channel scour was not observed. However, the left abutment footing was exposed one foot. Scour

  20. Level II scour analysis for Bridge 25 (JAMATH00010025) on Town Highway 1, crossing Ball Mountain Brook, Jamaica, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure JAMATH00010025 on Town Highway 1 crossing Ball Mountain Brook, Jamaica, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province in southern Vermont. The 29.5-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest except on the downstream right bank which is pasture with some trees along the channel. In the study area, Ball Mountain Brook has an incised, straight channel with a slope of approximately 0.021 ft/ft, an average channel top width of 86 ft and an average bank height of 9 ft. The channel bed material ranges from gravel to bedrock with a median grain size (D50) of 222 mm (0.727 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 13, 1996, indicated that the reach was stable. The Town Highway 1 crossing of Ball Mountain Brook is a 78-ft-long, two-lane bridge consisting of one 75-foot steel-beam span (Vermont Agency of Transportation, written communication, March 29, 1995). The opening length of the structure parallel to the bridge face is 73 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 30 degrees to the opening while the opening-skew-to-roadway is 30 degrees. A scour hole 1.0 ft deeper than the mean thalweg depth

  1. Level II scour analysis for Bridge 5 (DUMMVT00300005) on State Route 30, crossing Stickney Brook, Dummerston, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure DUMMVT00300005 on State Route 30 crossing Stickney Brook, Dummerston, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in southeastern Vermont. The 6.31-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest and brush. In the study area, Stickney Brook has an incised, straight channel with a slope of approximately 0.04 ft/ft, an average channel top width of 80 ft and an average bank height of 7 ft. The channel bed material is predominantly cobble with a median grain size (D50) of 80.3 mm (0.264 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 12, 1996, indicated that the reach was aggrading. The State Route 30 crossing of Stickney Brook is a 84-ft-long, two-lane bridge consisting of one 82-foot steel-beam span (Vermont Agency of Transportation, written communication, March 30, 1995). The opening length of the structure parallel to the bridge face is 79.7 ft. The bridge is supported by vertical, concrete abutments with spill-through embankments. The channel is skewed approximately 5 degrees to the opening while the opening-skew-to-roadway is 0 degrees. A scour hole 0.5 ft deeper than the mean thalweg depth was observed along the toe of the right spill-through slope during

  2. Level II scour analysis for Bridge 38 (TOPSTH00570038) on Town Highway 57, crossing Waits River, Topsham, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Boehmler, Erick M.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure TOPSTH00570038 on Town Highway 57 crossing the Waits River, Topsham, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in east central Vermont. The 37.3-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is predominantly pasture while the left bank upstream is suburban. In the study area, the Waits River has a sinuous locally anabranched channel with a slope of approximately 0.01 ft/ft, an average channel top width of 76 ft and an average bank height of 6 ft. The channel bed material ranges from sand to cobble with a median grain size (D50) of 57.2 mm (0.188 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 28, 1995, indicated that the reach was considered laterally unstable due to cut-banks upstream, mid-channel bars and lateral migration of the channel towards the left abutment. The Town Highway 34 crossing of the Waits River is a 34-ft-long, one-lane bridge consisting of one 31-foot steel-beam span (Vermont Agency of Transportation, written communication, March 28, 1995). The opening length of the structure parallel to the bridge face is 30.4 ft. The bridge is supported by a vertical, stone abutment with concrete facing and wingwalls on the right and by a vertical, concrete

  3. Level II scour analysis for Bridge 18 (GROTTH00480018) on Town Highway 48, crossing the Wells River Groton, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Medalie, Laura

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure GROTTH00480018 on Town Highway 48 crossing the Wells River, Groton, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in eastern Vermont. The 53.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture on the right bank upstream and the left bank downstream while the surface cover is shrub and brushland along the left bank upstream and the right bank downstream. The immediate banks are vegetated with brush and scattered trees. In the study area, the Wells River has an incised, straight channel with a slope of approximately 0.003 ft/ft, an average channel top width of 69 ft and an average bank height of 7 ft. The channel bed material ranges from sand to cobble with a median grain size (D50) of 66.7 mm (0.219 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 28, 1995, indicated that the reach was stable. The Town Highway 48 crossing of the Wells River is a 38-ft-long, one-lane bridge consisting of one 36-foot steel-beam span (Vermont Agency of Transportation, written communication, March 24, 1995). The opening length of the structure parallel to the bridge face is 33.7 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed

  4. Building Cross-Cultural Bridges--Cultural Analysis of Critical Incidents.

    ERIC Educational Resources Information Center

    White, Caroline

    Culture forms the basis for cross-cultural awareness and understanding. The initial response to a new culture is to find it fascinating, exotic, and thrilling. Although, to function in a new cultural environment, and become aware of deep cultural patterns people need time, research, and investigation. Dealing with a new culture, people need a…

  5. Level II scour analysis for Bridge 22 (JAY-TH00400022) on Town Highway 40, crossing Jay Branch, Jay, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Song, Donald L.

    1997-01-01

    8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province in northern Vermont. The 2.15-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is primarily pasture on the upstream and downstream left overbank while the immediate banks have dense woody vegetation. The downstream right overbank of the bridge is forested. In the study area, Jay Branch Tributary has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 26 ft and an average bank height of 3 ft. The channel bed material ranges from gravel to cobble with a median grain size (D50) of 40.5 mm (0.133 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 7, 1995, indicated that the reach was stable. The Town Highway 40 crossing of Jay Branch Tributary is a 27-ft-long, two-lane bridge consisting of one 25-foot steel-beam span (Vermont Agency of Transportation, written communication, March 6, 1995). The opening length of the structure parallel to the bridge face is 23.5 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel skew and the opening-skew-to-roadway are zero degrees. The scour counter-measures at the site included type-2 stone fill (less than 36 inches diameter) at the upstream end of the left and right abutments, at the upstream right wingwall, and at the downstream left

  6. Amphibians crossing the Bering Land Bridge: evidence from holarctic treefrogs (Hyla, Hylidae, Anura).

    PubMed

    Li, Jia-Tang; Wang, Ji-Shan; Nian, Hui-Huang; Litvinchuk, Spartak N; Wang, Jichao; Li, Yang; Rao, Ding-Qi; Klaus, Sebastian

    2015-06-01

    Based on an updated, time-calibrated phylogeny and applying biogeographical model testing and diversification analysis, we re-examined systematics and biogeography of the Holarctic treefrog genus Hyla with a focus on the East Asian species. We analyzed four mitochondrial genes (12S and 16S rRNA, tRNA(Leu), ND1) and one nuclear gene (POMC) for 192 samples representing 30 species of Hyla. Based on our results we suggest that H. ussuriensis is a synonym of H. japonica. Specimens from Sakhalin and Kunashir Islands might represent a cryptic species within H. japonica. We confirm earlier hypotheses that the genus Hyla originated during the Eocene to Early Oligocene and that Eurasian species originated from two independent dispersal events from North America via the Bering Land Bridge. Middle Eocene to Oligocene dispersal gave rise to the most recent common ancestor of the West Palearctic H. arborea-group and the East Palearctic, newly defined, H. chinensis-group. The Northeast Asian H. japonica-group resulted from a second wave of colonization from the Nearctic. A trans-Atlantic dispersal route could be excluded. Dispersal of the H. arborea-group to the western Palearctic coincides with the closure of the Turgai Strait at the end of the Oligocene. Diversification of Hyla decreased at the end of the Middle Miocene, possibly coinciding with the end of the Mid Miocene Climatic Optimum and the advent of cooler and drier climates in the Northern Hemisphere. PMID:25765368

  7. Effects of MgATP and MgADP on the cross-bridge kinetics of rabbit soleus slow-twitch muscle fibers.

    PubMed Central

    Wang, G; Kawai, M

    1996-01-01

    The elementary steps surrounding the nucleotide binding step in the cross-bridge cycle were investigated with sinusoidal analysis in rabbit soleus slow-twitch muscle fibers. The single-fiber preparations were activated at pCa 4.40, ionic strength 180 mM, 20 degrees C, and the effects of MgATP (S) and MgADP (D) concentrations on three exponential processes B, C, and D were studied. Our results demonstrate that all apparent (measured) rate constants increased and saturated hyperbolically as the MgATP concentration was increased. These results are consistent with the following cross-bridge scheme: [cross-bridge scheme: see text] where A = actin, M = myosin, S = MgATP, and D = MgADP. AM+S is a collision complex, and AM*S is its isomerized form. From our studies, we obtained K0 = 18 +/- 4 mM-1 (MgADP association constant, N = 7, average +/- sem), K1a = 1.2 +/- 0.3 mM-1 (MgATP association constant, N = 8 hereafter), k1b = 90 +/- 20 s-1 (rate constant of ATP isomerization), k-1b = 100 +/- 9 s-1 (rate constant of reverse isomerization), K1b = 1.0 +/- 0.2 (equilibrium constant of isomerization), k2 = 21 +/- 3 s-1 (rate constant of cross-bridge detachment), k-2 = 14.1 +/- 1.0 s-1 (rate constant of reversal of detachment), and K2 = 1.6 +/- 0.3 (equilibrium constant of detachment). K0 is 8 times and K1a is 2.2 times those in rabbit psoas, indicating that nucleotides bind to cross-bridges more tightly in soleus slow-twitch muscle fibers than in psoas fast-twitch muscle fibers. These results indicate that cross-bridges of slow-twitch fibers are more resistant to ATP depletion than those of fast-twitch fibers. The rate constants of ATP isomerization and cross-bridge detachment steps are, in general, one-tenth to one-thirtieth of those in psoas. PMID:8874019

  8. Level II scour analysis for Bridge 6 (FAYSTH00010006) on Town Highway 1, crossing Shepard Brook, Fayston, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Flynn, Robert H.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure FAYSTH00010006 on Town Highway 1 crossing Shepard Brook, Fayston, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province in central Vermont. The 16.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest. In the study area, Shepard Brook has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 56 ft and an average bank height of 3 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 72.6 mm (0.238 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 2, 1996, indicated that the reach was stable. The Town Highway 1 crossing of the Shepard Brook is a 42-ft-long, two-lane bridge consisting of one 40-foot concrete T-beam span (Vermont Agency of Transportation, written communication, October 13, 1995). The opening length of the structure parallel to the bridge face is 39.6 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15 degrees to the opening while the calculated opening-skew-to-roadway is 30 degrees. Scour, 2.0 ft deeper than the mean thalweg depth, was observed along the right abutment during the Level I assessment. The left abutment is

  9. Level II scour analysis for Bridge 21 (MORETH00010021) on Town Highway 1, crossing Cox Brook, Moretown, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Medalie, Laura

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure MORETH00010021 on Town Highway 1 crossing Cox Brook, Moretown, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province in north-central Vermont. The 2.85-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is predominantly forested. In the study area, Cox Brook has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 23 ft and an average bank height of 4 ft. The channel bed material ranges from gravel to cobble with a median grain size (D50) of 47.5 mm (0.156 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 18, 1996, indicated that the reach was stable. The Town Highway 1 crossing of Cox Brook is a 29-ft-long, two-lane bridge consisting of one 27-foot steel-beam span (Vermont Agency of Transportation, written communication, October 13, 1995). The opening length of the structure parallel to the bridge face is 24.8 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 60 degrees to the opening while the measured opening-skew-to-roadway is 40 degrees. A scour hole 1.0 ft deeper than the mean thalweg depth was observed along the left abutment downstream during the Level I assessment. The

  10. Level II scour analysis for Bridge 26 (WSTOTH00070026) on Town Highway 7, crossing Greendale Brook, Weston, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Hammond, Robert A.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure WSTOTH00070026 on Town Highway 7 crossing Greendale Brook, Weston, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province in south central Vermont. The 3.13-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest. In the study area, the Greendale Brook has a sinuous, non-incised, non-alluvial channel with a slope of approximately 0.015 ft/ft, an average channel top width of 38 ft and an average bank height of 3 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 64.8 mm (0.213 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 19, 1996, indicated that the reach was laterally unstable. The channel has moved to the right, however, scour countermeasures are in place along the upstream right bank. The Town Highway 7 crossing of the Greendale Brook is a 52-ft-long, two-lane bridge consisting of one 50-foot steel-beam span with a concrete deck (Vermont Agency of Transportation, written communication, April 07, 1995). The opening length of the structure parallel to the bridge face is 48.6 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 50 degrees to the opening while the opening

  11. Level II scour analysis for Bridge 4 (MAIDTH00070004) on Town Highway 7, crossing Cutler Mill Brook, Maidstone, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Medalie, Laura

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure MAIDTH00070004 on Town Highway 7 crossing the Cutler Mill Brook, Maidstone, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the White Mountain section of the New England physiographic province in northeastern Vermont. The 18.1-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is predominantly shrub and brushland. In the study area, the Cutler Mill Brook has a non-incised, meandering channel with local braiding and a slope of approximately 0.004 ft/ft, an average channel top width of 43 ft and an average bank height of 2 ft. The channel bed material ranges from sand to cobble with a median grain size (D50) of 27.6 mm (0.091 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 19, 1995, indicated that the reach was laterally unstable due to large meanders in the channel. The Town Highway 7 crossing of the Cutler Mill Brook is a 25-ft-long, one-lane bridge consisting of one 22-foot concrete span (Vermont Agency of Transportation, written communication, August 5, 1994). The opening length of the structure parallel to the bridge face is 21.7 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 20 degrees to the opening while the opening-skew-to-roadway is 0 degrees. A scour hole 2.0 ft deeper than

  12. Bathymetric and velocimetric surveys at highway bridges crossing the Missouri River in and into Missouri during summer flooding, July-August 2011

    USGS Publications Warehouse

    Huizinga, Richard J.

    2012-01-01

    Bathymetric and velocimetric surveys were conducted by the U.S. Geological Survey, in cooperation with the Kansas and Missouri Departments of Transportation, in the vicinity of 36 bridges at 27 highway crossings of the Missouri River between Brownville, Nebraska and St. Louis, Missouri, from July 13 through August 3, 2011, during a summer flood. A multibeam echo sounder mapping system was used to obtain channel-bed elevations for river reaches ranging from 1,350 to 1,860 feet and extending across the active channel of the Missouri River. These bathymetric scans provide a "snapshot" of the channel conditions at the time of the surveys and provide characteristics of scour holes that may be useful in the development of predictive guidelines or equations for scour holes. These data also may be used by the Kansas and Missouri Departments of Transportation to assess the bridges for stability and integrity issues with respect to bridge scour during floods. Bathymetric data were collected around every pier that was in water, except those at the edge of water, in extremely shallow water, or surrounded by debris rafts. Scour holes were present at most piers for which bathymetry could be obtained, except at piers on channel banks, those near or embedded in lateral or longitudinal spur dikes, and those on exposed bedrock outcrops. Scour holes observed at the surveyed bridges were examined with respect to depth and shape. Although exposure of parts of foundational support elements was observed at several piers, at most sites the exposure likely can be considered minimal compared to the overall substructure that remains buried in bed material; however, there were several notable exceptions where the bed material thickness between the bottom of the scour hole and bedrock was less than 6 feet. Such substantial exposure of usually buried substructural elements may warrant special observation in future flood events. Previous bathymetric surveys had been done at several of the sites

  13. Level II scour analysis for Bridge 18 (SHEFTH00410018) on Town Highway 41, crossing Millers Run, Sheffield, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Boehmler, Erick M.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure SHEFTH00410018 on Town Highway 41 crossing Millers Run, Sheffield, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the White Mountain section of the New England physiographic province in northeastern Vermont. The 16.2-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is grass upstream and downstream of the bridge while the immediate banks have dense woody vegetation. In the study area, Millers Run has an incised, straight channel with a slope of approximately 0.01 ft/ft, an average channel top width of 50 ft and an average bank height of 6 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 50.9 mm (0.167 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 1, 1995, indicated that the reach was laterally unstable, which is evident in the moderate to severe fluvial erosion in the upstream reach. The Town Highway 41 crossing of the Millers Run is a 30-ft-long, one-lane bridge consisting of a 28-foot steel-stringer span (Vermont Agency of Transportation, written communication, March 28, 1995). The opening length of the structure parallel to the bridge face is 22.2 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 20 degrees to the opening. The computed

  14. Reversal of the cross-bridge force-generating transition by photogeneration of phosphate in rabbit psoas muscle fibres.

    PubMed Central

    Dantzig, J A; Goldman, Y E; Millar, N C; Lacktis, J; Homsher, E

    1992-01-01

    1. Orthophosphate (P(i), 0.1-2.0 mM) was photogenerated within the filament lattice of isometrically contracting glycerinated fibres of rabbit psoas muscle at 10 and 20 degrees C. The P(i) was produced by laser flash photolysis of the photolabile compound 1-(2-nitrophenyl)ethylphosphate (caged P(i)). Caged P(i) caused a depression of tension that was much smaller than that caused by P(i). 2. Photolysis of caged P(i) produced a decline in isometric force composed of four phases: phase I, a lag phase (e.g. 1-4 ms at 10 degrees C) during which force did not change; phase II, an exponential decline by as much as 20% of the pre-pulse force; phase III, a partial force recovery (0-3% of the pre-pulse force); and phase IV, a further slow (0.5-3 s) decline to the steady value. Phases I, III and IV were largely independent of [P(i)] and are likely to be indirect effects caused by the caged P(i) photolysis. 3. Both the rate and amplitude of phase II depended markedly on [P(i)]. The amplitude of phase II was similar to the reduction of steady-state force by P(i). The rate of phase II increased with increasing temperature and [P(i)]. At high [P(i)] the rate began to saturate, and approached limits of 123 s-1 at 10 degrees C and 194 s-1 at 20 degrees C. 4. The rate of phase II was independent of sarcomere overlap, while the amplitude was proportional to tension at partial filament overlap. A control experiment using caged ATP showed that phase II was not produced by the photolytic by-products or the light pulse. The results suggest that phase II is associated with the force-generating transition of the cross-bridge cycle. 5. Sinusoidal length oscillations at 0.5 and 2 kHz were used to measure muscle stiffness during phase II. Stiffness declined in a single exponential phase, with the same time course as phase II of the tension transient. The change in stiffness was 83 +/- 6% (mean +/- S.E.M., n = 10, 0.5 kHz) of the change in tension when both signals were normalized to their

  15. Level II scour analysis for Bridge 35 (BRIDTH00050035) on Town Highway 05, crossing the North Branch Ottauquechee River, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Ayotte, Joseph D.

    1996-01-01

    year discharge. Abutment scour ranged from 8.0 to 15.1 ft. with the worst-case abutment scour occurring at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, including historical performance during flood events, the geomorphic assessment, scour protection measures, and the results of the hydraulic analyses, must be considered to properly assess the validity of abutment scour results. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein, based on the consideration of additional contributing factors and experienced engineering judgement.

  16. Impact of familial hypertrophic cardiomyopathy-linked mutations in the NH2 terminus of the RLC on β-myosin cross-bridge mechanics.

    PubMed

    Farman, Gerrie P; Muthu, Priya; Kazmierczak, Katarzyna; Szczesna-Cordary, Danuta; Moore, Jeffrey R

    2014-12-15

    Familial hypertrophic cardiomyopathy (HCM) is associated with mutations in sarcomeric proteins, including the myosin regulatory light chain (RLC). Here we studied the impact of three HCM mutations located in the NH2 terminus of the RLC on the molecular mechanism of β-myosin heavy chain (MHC) cross-bridge mechanics using the in vitro motility assay. To generate mutant β-myosin, native RLC was depleted from porcine cardiac MHC and reconstituted with mutant (A13T, F18L, and E22K) or wild-type (WT) human cardiac RLC. We characterized the mutant myosin force and motion generation capability in the presence of a frictional load. Compared with WT, all three mutants exhibited reductions in maximal actin filament velocity when tested under low or no frictional load. The actin-activated ATPase showed no significant difference between WT and HCM-mutant-reconstituted myosins. The decrease in velocity has been attributed to a significantly increased duty cycle, as was measured by the dependence of actin sliding velocity on myosin surface density, for all three mutant myosins. These results demonstrate a mutation-induced alteration in acto-myosin interactions that may contribute to the pathogenesis of HCM. PMID:25324513

  17. Aspartate-Based CXCR4 Chemokine Receptor Binding of Cross-Bridged Tetraazamacrocyclic Copper(II) and Zinc(II) Complexes.

    PubMed

    Maples, Randall D; Cain, Amy N; Burke, Benjamin P; Silversides, Jon D; Mewis, Ryan E; D'huys, Thomas; Schols, Dominique; Linder, Douglas P; Archibald, Stephen J; Hubin, Timothy J

    2016-08-26

    The CXCR4 chemokine receptor is implicated in a number of diseases including HIV infection and cancer development and metastasis. Previous studies have demonstrated that configurationally restricted bis-tetraazamacrocyclic metal complexes are high-affinity CXCR4 antagonists. Here, we present the synthesis of Cu(2+) and Zn(2+) acetate complexes of six cross-bridged tetraazamacrocycles to mimic their coordination interaction with the aspartate side chains known to bind them to CXCR4. X-ray crystal structures for three new Cu(2+) acetate complexes and two new Zn(2+) acetate complexes demonstrate metal-ion-dependent differences in the mode of binding the acetate ligand concomitantly with the requisite cis-V-configured cross-bridged tetraazamacrocyle. Concurrent density functional theory molecular modelling studies produced an energetic rationale for the unexpected [Zn(OAc)(H2 O)](+) coordination motif present in all of the Zn(2+) cross-bridged tetraazamacrocycle crystal structures, which differs from the chelating acetate [Zn(OAc)](+) structures of known unbridged and side-bridged tetraazamacrocyclic Zn(2+) -containing CXCR4 antagonists. PMID:27458983

  18. 3-D structural analysis of the crucial intermediate of skeletal muscle myosin and its role in revised actomyosin cross-bridge cycle

    PubMed Central

    Katayama, Eisaku

    2014-01-01

    Skeletal myosin S1 consists of two functional segments, a catalytic-domain and a lever-arm. Since the crystal structure of ADP/Vi-bound S1 exhibits a strong intramolecular flexure between two segments, inter-conversion between bent and extended forms; i.e. “tilting of the lever-arm” has been accepted as the established molecular mechanism of skeletal muscle contraction. We utilized quick-freeze deep-etch replica electron microscopy to directly visualize the structure of in vitro actin-sliding myosin, and found the existence of a novel oppositely-bent configuration, instead of the expected ADP/Vi-bound form. We also noticed that SH1–SH2 cross-linked myosin gives an aberrant appearance similar to the above structure. Since SH1–SH2-cross-linked myosin is a well-studied analogue of the transient intermediate of the actomyosin cross-bridge cycle, we devised a new image-processing procedure to define the relative view-angles between the catalytic-domain and the lever-arm from those averaged images, and built a 3-D model of the new conformer. The lever-arm in that model was bent oppositely to the ADP/Vi-bound form, in accordance with observed actin-sliding cross-bridge structure. Introducing this conformer as the crucial intermediate that transiently appears during sliding, we propose a revised scheme of the cross-bridge cycle. In the scenario, the novel conformer keeps actin-binding in two different modes until it forms a primed configuration. The final extension of the lever-arm back to the original rigor-state constitutes the “power-stroke”. Various images observed during sliding could be easily interpreted by the new conformer. Even the enigmatic behavior of the cross-bridges reported as “loose chemo-mechanical coupling” might be adequately explained under some assumptions. PMID:27493503

  19. Bathymetric surveys at highway bridges crossing the Missouri River in Kansas City, Missouri, using a multibeam echo sounder, 2010

    USGS Publications Warehouse

    Huizinga, Richard J.

    2010-01-01

    Bathymetric surveys were conducted by the U.S. Geological Survey, in cooperation with the Missouri Department of Transportation, on the Missouri River in the vicinity of nine bridges at seven highway crossings in Kansas City, Missouri, in March 2010. A multibeam echo sounder mapping system was used to obtain channel-bed elevations for river reaches that ranged from 1,640 to 1,800 feet long and extending from bank to bank in the main channel of the Missouri River. These bathymetric scans will be used by the Missouri Department of Transportation to assess the condition of the bridges for stability and integrity with respect to bridge scour. Bathymetric data were collected around every pier that was in water, except those at the edge of the water or in extremely shallow water, and one pier that was surrounded by a large debris raft. A scour hole was present at every pier for which bathymetric data could be obtained. The scour hole at a given pier varied in depth relative to the upstream channel bed, depending on the presence and proximity of other piers or structures upstream from the pier in question. The surveyed channel bed at the bottom of the scour hole was between 5 and 50 feet above bedrock. At bridges with drilled shaft foundations, generally there was exposure of the upstream end of the seal course and the seal course often was undermined to some extent. At one site, the minimum elevation of the scour hole at the main channel pier was about 10 feet below the bottom of the seal course, and the sides of the drilled shafts were evident in a point cloud visualization of the data at that pier. However, drilled shafts generally penetrated 20 feet into bedrock. Undermining of the seal course was evident as a sonic 'shadow' in the point cloud visualization of several of the piers. Large dune features were present in the channel at nearly all of the surveyed sites, as were numerous smaller dunes and many ripples. Several of the sites are on or near bends in the river

  20. Level II scour analysis for Bridge 31 (JERITH00350031) on Town Highway 35, crossing Mill Brook, Jericho, Vermont

    USGS Publications Warehouse

    Wild, Emily C.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.4 to 1.3 ft. The worst-case contraction scour occurred at the 500-year discharge. Left abutment scour ranged from 9.9 to 12.4 ft. Right abutment scour ranged from 13.8 to 17.8 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  1. The increase in non-cross-bridge forces after stretch of activated striated muscle is related to titin isoforms.

    PubMed

    Cornachione, Anabelle S; Leite, Felipe; Bagni, Maria Angela; Rassier, Dilson E

    2016-01-01

    Skeletal muscles present a non-cross-bridge increase in sarcomere stiffness and tension on Ca(2+) activation, referred to as static stiffness and static tension, respectively. It has been hypothesized that this increase in tension is caused by Ca(2+)-dependent changes in the properties of titin molecules. To verify this hypothesis, we investigated the static tension in muscles containing different titin isoforms. Permeabilized myofibrils were isolated from the psoas, soleus, and heart ventricle from the rabbit, and tested in pCa 9.0 and pCa 4.5, before and after extraction of troponin C, thin filaments, and treatment with the actomyosin inhibitor blebbistatin. The myofibrils were tested with stretches of different amplitudes in sarcomere lengths varying between 1.93 and 3.37 μm for the psoas, 2.68 and 4.21 μm for the soleus, and 1.51 and 2.86 μm for the ventricle. Using gel electrophoresis, we confirmed that the three muscles tested have different titin isoforms. The static tension was present in psoas and soleus myofibrils, but not in ventricle myofibrils, and higher in psoas myofibrils than in soleus myofibrils. These results suggest that the increase in the static tension is directly associated with Ca(2+)-dependent change in titin properties and not associated with changes in titin-actin interactions. PMID:26405100

  2. Level II scour analysis for Bridge 32 (CONCTH00030032) on Town Highway 3, crossing the Moose River, Concord, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.7 ft. Abutment scour ranged from 9.9 to 16.4 ft. Pier scour ranged from 14.4 to 16.2 ft. The worst-case contraction, abutment, and pier scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  3. Level II scour analysis for Bridge 6 (VICTTH000110006) on Town Highway 1, crossing the Moose River, Victory, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.2 to 0.4 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.3 to 8.2 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  4. Bridge-scour analysis on Cuchillo Negro Creek at the Interstate 25 crossing near Truth or Consequences, New Mexico

    USGS Publications Warehouse

    Waltemeyer, S.D.

    1995-01-01

    A sediment-transport model to simulate channel change was applied to a 1-mile reach of Cuchillo Negro Creek at the Interstate 25 crossing at Truth or Consequences, New Mexico, using the Bridge-Stream Tube model for Alluvial River Simulation (BRI-STARS). The 500-year flood discharge was estimated to be 10,700 cubic feet per second. The 100-year, 500-year, and regional maximum discharges were used to design synthetic and discretized hydrographs using a flood volume equation. The regional maximum discharge relation was developed for New Mexico based on 259 streamflow-gaging stations' maximum peak discharge. The regional maximum-peak discharge for the site was determined to be 81,700 cubic feet per second. Bed-material particle-size distribution was determined for six size classes ranging from 1 to 30 millimeters. The median diameter was 4.6 millimeters at the bed surface and 9.0 millimeters 13 feet below the bed surface. Bed-material discharge for use in the model was estimated to be 18,770 tons per day using hydraulic properties, water temperature, and Yang's gravel equation. Channel-change simulations showed a maximum channel degradation of 1.38 feet for the regional maximum-peak discharge hydrograph.

  5. Level II scour analysis for Bridge 29 (LONDTH00410029) on Town Highway 41, crossing Cook Brook, Londonderry, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Wild, Emily C.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 1.5. Abutment scour ranged from 8.4 to 15.1 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  6. Level II scour analysis for Bridge 4 (RYEGTH00050004) on Town Highway 5, crossing the Wells River, Ryegate, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Hammond, Robert E.

    1997-01-01

    Contraction scour for all modelled flows ranged from 1.8 to 2.6 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 10.2 to 22.6 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  7. Level II scour analysis for Bridge 81 (JAMAVT01000081) on State Route 100, crossing the Winhall River, Jamaica, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Hammond, Robert E.

    1997-01-01

    The contraction scour ranged from 0.0 to 2.6 ft. The worst-case contraction scour occurred at the incipient road-overtopping discharge. Abutment scour ranged from 7.9 to 21.9 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  8. Level II scour analysis for Bridge 80 (JAMAVT01000080) on State Highway 100, crossing the West River, Jamaica, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Degnan, James R.

    1997-01-01

    There was no computed contraction scour. Abutment scour ranged from 15.8 to 23.9 ft. The worst-case abutment scour occurred at the 500-year discharge. Pier scour ranged from 9.5 to 22.8 ft. The worst-case pier scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  9. Level II scour analysis for Bridge 30 (BRNATH00470030) on Town Highway 47, crossing Locust Creek, Barnard, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Song, Donald L.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 1.4 feet. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 2.3 to 8.9 feet. The worst-case abutment scour occurred at the 100-year discharge at the right abutment. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  10. Level II scour analysis for Bridge 5 (IRASTH00010005) on Town Highway 1, crossing Lords Creek, Irasburg, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Song, Donald L.

    1996-01-01

    Contraction scour for all modelled flows ranged from 2.4 to 4.6 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.2 to 9.8 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  11. Level II scour analysis for Bridge 26 (JAMATH00010026) on Town Highway 1, crossing Ball Mountain Brook, Jamaica, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Medalie, Laura

    1997-01-01

    Contraction scour for the modelled flows ranged from 1.0 to 2.7 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge. Abutment scour ranged from 8.4 to 17.6 ft. The worst-case abutment scour for the right abutment occurred at the incipient-overtopping discharge. For the left abutment, the worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  12. O(1) time algorithms for computing histogram and Hough transform on a cross-bridge reconfigurable array of processors

    SciTech Connect

    Kao, T.; Horng, S.; Wang, Y.

    1995-04-01

    Instead of using the base-2 number system, we use a base-m number system to represent the numbers used in the proposed algorithms. Such a strategy can be used to design an O(T) time, T = (log(sub m) N) + 1, prefix sum algorithm for a binary sequence with N-bit on a cross-bridge reconfigurable array of processors using N processors, where the data bus is m-bit wide. Then, this basic operation can be used to compute the histogram of an n x n image with G gray-level value in constant time using G x n x n processors, and compute the Hough transform of an image with N edge pixels and n x n parameter space in constant time using n x n x N processors, respectively. This result is better than the previously known results proposed in the literature. Also, the execution time of the proposed algorithms is tunable by the bus bandwidth. 43 refs.

  13. Level II scour analysis for Bridge 8, (MANCTH00060008) on Town Highway 6, crossing Bourn Brook, Manchester, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Hammond, Robert E.

    1997-01-01

    Contraction scour for all modelled flows was zero ft. The left abutment scour ranged from 3.6 to 9.2 ft. The worst-case left abutment scour occurred at the 500-year discharge. The right abutment scour ranged from 9.8 to 12.6 ft. The worst case right abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  14. Kinetics of a single cross-bridge in familial hypertrophic cardiomyopathy heart muscle measured by reverse Kretschmann fluorescence

    NASA Astrophysics Data System (ADS)

    Mettikolla, Prasad; Calander, Nils; Luchowski, Rafal; Gryczynski, Ignacy; Gryczynski, Zygmunt; Borejdo, Julian

    2010-01-01

    Familial hypertrophic cardiomyopathy (FHC) is a serious heart disease that often leads to a sudden cardiac death of young athletes. It is believed that the alteration of the kinetics of interaction between actin and myosin causes FHC by making the heart to pump blood inefficiently. We set out to check this hypothesis ex vivo. During contraction of heart muscle, a myosin cross-bridge imparts periodic force impulses to actin. The impulses are analyzed by fluorescence correlation spectroscopy (FCS) of fluorescently labeled actin. To minimize observation volume and background fluorescence, we carry out FCS measurements in surface plasmon coupled emission mode in a reverse Kretschmann configuration. Fluorescence is a result of near-field coupling of fluorophores excited in the vicinity of the metal-coated surface of a coverslip with the surface plasmons propagating in the metal. Surface plasmons decouple on opposite sides of the metal film and emit in a directional manner as far-field p-polarized radiation. We show that the rate of changes of orientation is significantly faster in contracting cardiac myofibrils of transgenic mice than wild type. These results are consistent with the fact that mutated heart muscle myosin translates actin faster in in vitro motility assays.

  15. Level II scour analysis for Bridge 7 (CHARTH00010007) on Town Highway 1, crossing Mad Brook, Charleston, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Weber, Matthew A.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.3 ft. The worst-case contraction scour occurred at the incipient overtopping discharge, which was less than the 100-year discharge. Abutment scour ranged from 6.2 to 9.4 ft. The worst-case abutment scour for the right abutment was 9.4 feet at the 100-year discharge. The worst-case abutment scour for the left abutment was 8.6 feet at the incipient overtopping discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  16. Level II scour analysis for Bridge 36 (ANDOVT00110036) on VT 11, crossing Middle Branch Williams River, Andover, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Burns, Rhonda L.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 2.8 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 9.5 to 13.7 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  17. Level II scour analysis for Bridge 8 (WELLTH00020008) on Town Highway 2, crossing Wells Brook, Wells, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Ivanoff, Michael A.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.8 ft. The worst-case contraction scour occurred at the incipient roadway-overtopping discharge, which was less than the 100-year discharge. Abutment scour ranged from 5.6 to 10.0 ft at the left abutment and from 3.1 to 4.2 ft at the right abutment. The worst-case abutment scour occurred at the incipient roadway-overtopping discharge at the left abutment. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  18. Level II scour analysis for Bridge 36 (STOWTH00430036) on Town Highway 43, crossing Miller Brook, Stowe, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Wild, Emily C.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.9 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 3.1 to 6.5 ft. The worst-case abutment scour occurred at the 100-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  19. Level II scour analysis for Bridge 22 (WALDTH00180022) on Town Highway 18, crossing Coles Brook, Walden, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Ivanoff, Michael A.

    1997-01-01

    Contraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 6.4 to 7.9 ft at the left abutment and from 11.8 to 14.9 ft at the right abutment. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scouredstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particlesize distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  20. Level II scour analysis for Bridge 53 (CHESTH01180053) on Town Highway 118, crossing the Williams River, Chester, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Medalie, Laura

    1997-01-01

    Contraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 5.8 to 6.8 ft at the left abutment and 9.4 to 14.4 ft at the right abutment. The worst-case abutment scour occurred at the incipient roadway-overtopping discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  1. A Novel Type of Peptidoglycan-binding Domain Highly Specific for Amidated d-Asp Cross-bridge, Identified in Lactobacillus casei Bacteriophage Endolysins*

    PubMed Central

    Regulski, Krzysztof; Courtin, Pascal; Kulakauskas, Saulius; Chapot-Chartier, Marie-Pierre

    2013-01-01

    Peptidoglycan hydrolases (PGHs) are responsible for bacterial cell lysis. Most PGHs have a modular structure comprising a catalytic domain and a cell wall-binding domain (CWBD). PGHs of bacteriophage origin, called endolysins, are involved in bacterial lysis at the end of the infection cycle. We have characterized two endolysins, Lc-Lys and Lc-Lys-2, identified in prophages present in the genome of Lactobacillus casei BL23. These two enzymes have different catalytic domains but similar putative C-terminal CWBDs. By analyzing purified peptidoglycan (PG) degradation products, we showed that Lc-Lys is an N-acetylmuramoyl-l-alanine amidase, whereas Lc-Lys-2 is a γ-d-glutamyl-l-lysyl endopeptidase. Remarkably, both lysins were able to lyse only Gram-positive bacterial strains that possess PG with d-Ala4→d-Asx-l-Lys3 in their cross-bridge, such as Lactococcus casei, Lactococcus lactis, and Enterococcus faecium. By testing a panel of L. lactis cell wall mutants, we observed that Lc-Lys and Lc-Lys-2 were not able to lyse mutants with a modified PG cross-bridge, constituting d-Ala4→l-Ala-(l-Ala/l-Ser)-l-Lys3; moreover, they do not lyse the L. lactis mutant containing only the nonamidated d-Asp cross-bridge, i.e. d-Ala4→d-Asp-l-Lys3. In contrast, Lc-Lys could lyse the ampicillin-resistant E. faecium mutant with 3→3 l-Lys3-d-Asn-l-Lys3 bridges replacing the wild-type 4→3 d-Ala4-d-Asn-l-Lys3 bridges. We showed that the C-terminal CWBD of Lc-Lys binds PG containing mainly d-Asn but not PG with only the nonamidated d-Asp-containing cross-bridge, indicating that the CWBD confers to Lc-Lys its narrow specificity. In conclusion, the CWBD characterized in this study is a novel type of PG-binding domain targeting specifically the d-Asn interpeptide bridge of PG. PMID:23733182

  2. A novel type of peptidoglycan-binding domain highly specific for amidated D-Asp cross-bridge, identified in Lactobacillus casei bacteriophage endolysins.

    PubMed

    Regulski, Krzysztof; Courtin, Pascal; Kulakauskas, Saulius; Chapot-Chartier, Marie-Pierre

    2013-07-12

    Peptidoglycan hydrolases (PGHs) are responsible for bacterial cell lysis. Most PGHs have a modular structure comprising a catalytic domain and a cell wall-binding domain (CWBD). PGHs of bacteriophage origin, called endolysins, are involved in bacterial lysis at the end of the infection cycle. We have characterized two endolysins, Lc-Lys and Lc-Lys-2, identified in prophages present in the genome of Lactobacillus casei BL23. These two enzymes have different catalytic domains but similar putative C-terminal CWBDs. By analyzing purified peptidoglycan (PG) degradation products, we showed that Lc-Lys is an N-acetylmuramoyl-L-alanine amidase, whereas Lc-Lys-2 is a γ-D-glutamyl-L-lysyl endopeptidase. Remarkably, both lysins were able to lyse only Gram-positive bacterial strains that possess PG with D-Ala(4)→D-Asx-L-Lys(3) in their cross-bridge, such as Lactococcus casei, Lactococcus lactis, and Enterococcus faecium. By testing a panel of L. lactis cell wall mutants, we observed that Lc-Lys and Lc-Lys-2 were not able to lyse mutants with a modified PG cross-bridge, constituting D-Ala(4)→L-Ala-(L-Ala/L-Ser)-L-Lys(3); moreover, they do not lyse the L. lactis mutant containing only the nonamidated D-Asp cross-bridge, i.e. D-Ala(4)→D-Asp-L-Lys(3). In contrast, Lc-Lys could lyse the ampicillin-resistant E. faecium mutant with 3→3 L-Lys(3)-D-Asn-L-Lys(3) bridges replacing the wild-type 4→3 D-Ala(4)-D-Asn-L-Lys(3) bridges. We showed that the C-terminal CWBD of Lc-Lys binds PG containing mainly D-Asn but not PG with only the nonamidated D-Asp-containing cross-bridge, indicating that the CWBD confers to Lc-Lys its narrow specificity. In conclusion, the CWBD characterized in this study is a novel type of PG-binding domain targeting specifically the D-Asn interpeptide bridge of PG. PMID:23733182

  3. Mouse intact cardiac myocyte mechanics: cross-bridge and titin-based stress in unactivated cells.

    PubMed

    King, Nicholas M P; Methawasin, Methajit; Nedrud, Joshua; Harrell, Nicholas; Chung, Charles S; Helmes, Michiel; Granzier, Henk

    2011-01-01

    A carbon fiber-based cell attachment and force measurement system was used to measure the diastolic stress-sarcomere length (SL) relation of mouse intact cardiomyocytes, before and after the addition of actomyosin inhibitors (2,3-butanedione monoxime [BDM] or blebbistatin). Stress was measured during the diastolic interval of twitching myocytes that were stretched at 100% base length/second. Diastolic stress increased close to linear from 0 at SL 1.85 µm to 4.2 mN/mm(2) at SL 2.1 µm. The actomyosin inhibitors BDM and blebbistatin significantly lowered diastolic stress by ∼1.5 mN/mm(2) (at SL 2.1 µm, ∼30% of total), suggesting that during diastole actomyosin interaction is not fully switched off. To test this further, calcium sensitivity of skinned myocytes was studied under conditions that simulate diastole: 37°C, presence of Dextran T500 to compress the myofilament lattice to the physiological level, and [Ca(2+)] from below to above 100 nM. Mean active stress was significantly increased at [Ca(2+)] > 55 nM (pCa 7.25) and was ∼0.7 mN/mm(2) at 100 nM [Ca(2+)] (pCa 7.0) and ∼1.3 mN/mm(2) at 175 nM Ca(2+) (pCa 6.75). Inhibiting active stress in intact cells attached to carbon fibers at their resting SL and stretching the cells while first measuring restoring stress (pushing outward) and then passive stress (pulling inward) made it possible to determine the passive cell's mechanical slack SL as ∼1.95 µm and the restoring stiffness and passive stiffness of the cells around the slack SL each as ∼17 mN/mm(2)/µm/SL. Comparison between the results of intact and skinned cells shows that titin is the main contributor to restoring stress and passive stress of intact cells, but that under physiological conditions, calcium sensitivity is sufficiently high for actomyosin interaction to contribute to diastolic stress. These findings are relevant for understanding diastolic function and for future studies of diastolic heart failure. PMID:21187335

  4. Isomeric Trimethylene and Ethylene Pendant-armed Cross-bridged Tetraazamacrocycles and in Vitro/in Vivo Comparisions of their Copper(II) Complexes

    PubMed Central

    2011-01-01

    Ethylene cross-bridged tetraamine macrocycles are useful chelators in coordination, catalytic, medicinal, and radiopharmaceutical chemistry. Springborg and co-workers developed trimethylene cross-bridged analogues, although their pendant-armed derivatives received little attention. We report here the synthesis of a bis-carboxymethyl pendant-armed cyclen with a trimethylene cross-bridge (C3B-DO2A) and its isomeric ethylene-cross-bridged homocyclen ligand (CB-TR2A) as well as their copper(II) complexes. The in vitro and in vivo properties of these complexes are compared with respect to their potential application as 64Cu-radiopharmaceuticals in positron emission tomography (PET imaging). The inertness of Cu-C3B-DO2A to decomplexation is remarkable, exceeding that of Cu-CB-TE2A. Electrochemical reduction of Cu-CB-TR2A is quasi-reversible, whereas that of Cu-C3B-DO2A is irreversible. The reaction conditions for preparing 64Cu-C3B-DO2A (microwaving at high temperature) are relatively harsh compared to 64Cu-CB-TR2A (basic ethanol). The in vivo behavior of the 64Cu complexes was evaluated in normal rats. Rapid and continual clearance of 64Cu-CB-TR2A through the blood, liver, and kidneys suggests relatively good in vivo stability, albeit inferior to 64Cu-CB-TE2A. Although 64Cu-C3B-DO2A clears continually, the initial uptake is high and only about half is excreted within 22 h, suggesting poor stability and transchelation of 64Cu to proteins in the blood and/or liver. These data suggest that in vitro inertness of a chelator complex may not always be a good indicator of in vivo stability. PMID:21381676

  5. Cell wall monoglycine cross-bridges and methicillin hypersusceptibility in a femAB null mutant of methicillin-resistant Staphylococcus aureus.

    PubMed Central

    Strandén, A M; Ehlert, K; Labischinski, H; Berger-Bächi, B

    1997-01-01

    The femAB operon is involved in the formation of the characteristic pentaglycine side chain of the staphylococcal peptidoglycan. Allele replacement of the femAB operon with the tetracycline resistance determinant tetK in a methicillin-resistant Staphylococcus aureus strain resulted in impaired growth, methicillin hypersusceptibility, and lysostaphin resistance. The usual pentaglycine cross-bridges were replaced by monoglycine bridges exclusively, and cross-linking of the peptidoglycan strands was drastically reduced. Complementation of the femAB null mutant by either femA or femAB resulted in the extension of the cross-bridges to a triglycine or a pentaglycine, respectively. This finding suggests that FemA is responsible for the formation of glycines 2 and 3, and FemB is responsible for formation of glycines 4 and 5, of the pentaglycine side chain of the peptidoglycan precursor. Moreover, it can be deduced that addition of the first glycine must occur by a femAB-independent mechanism. PMID:8981974

  6. From cycling between coupled reactions to the cross-bridge cycle: mechanical power output as an integral part of energy metabolism.

    PubMed

    Diederichs, Frank

    2012-01-01

    ATP delivery and its usage are achieved by cycling of respective intermediates through interconnected coupled reactions. At steady state, cycling between coupled reactions always occurs at zero resistance of the whole cycle without dissipation of free energy. The cross-bridge cycle can also be described by a system of coupled reactions: one energising reaction, which energises myosin heads by coupled ATP splitting, and one de-energising reaction, which transduces free energy from myosin heads to coupled actin movement. The whole cycle of myosin heads via cross-bridge formation and dissociation proceeds at zero resistance. Dissipation of free energy from coupled reactions occurs whenever the input potential overcomes the counteracting output potential. In addition, dissipation is produced by uncoupling. This is brought about by a load dependent shortening of the cross-bridge stroke to zero, which allows isometric force generation without mechanical power output. The occurrence of maximal efficiency is caused by uncoupling. Under coupled conditions, Hill's equation (velocity as a function of load) is fulfilled. In addition, force and shortening velocity both depend on [Ca2+]. Muscular fatigue is triggered when ATP consumption overcomes ATP delivery. As a result, the substrate of the cycle, [MgATP2-], is reduced. This leads to a switch off of cycling and ATP consumption, so that a recovery of [ATP] is possible. In this way a potentially harmful, persistent low energy state of the cell can be avoided. PMID:24957757

  7. Level II scour analysis for Bridge 25 (BRNAVT00120025) on State Highway 12, crossing Locust Creek, Barnard, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Weber, Matthew A.

    1996-01-01

    abutments with wingwalls. The channel is skewed approximately 30 degrees to the opening while the opening-skew-to-roadway is 45 degrees. A scour hole 1 ft deeper than the mean thalweg depth was observed along a bedrock outcrop near the upstream left wingwall during the Level I assessment. The scour protection measures in place at the site are type-1 stone fill (less than 12 inches diameter) along the left abutment, upstream right bank, and both downstream banks; type-2 stone fill (less than 36 inches diameter) at the downstream side of the right road approach and upstream left bank; type-3 stone fill (less than 48 inches diameter) at the upstream end of the upstream right wingwall and downstream end of downstream left wingwall; type-5 (wall/ artificial levee) at the upstream end of the upstream left wingwall. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0.0 to 1.4 ft. The worst-case contraction scour occurred at the 100-year discharge. Abutment scour ranged from 8.5 to 20.9 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in

  8. An amateur's contribution to the design of Telford's Menai Suspension Bridge: a commentary on Gilbert (1826) ‘On the mathematical theory of suspension bridges’

    PubMed Central

    Calladine, C. R.

    2015-01-01

    Davies Gilbert's work on the catenary is notable on two counts. First, it influenced Thomas Telford in formulating his final design for the Menai Strait suspension bridge (1826); and second, it established for the first time the form of the ‘catenary of equal strength’. The classical catenary is a uniform flexible chain or cable hanging freely under gravity between supports. The ‘catenary of equal strength’ is the form of a cable whose cross-sectional area is made proportional to the tension at each point, so that the tensile stress is uniform throughout. In this paper I provide a sketch of the lives and achievements of Gilbert and Telford, and of their interaction over the Menai Bridge. There follows a commentary on Gilbert's 1826 paper, and on his two related publications; and a brief sketch of the earlier history of the catenary. I then describe the development of the suspension bridge up to the present time. Finally, I discuss relations between mathematical analysts and practical engineers. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. PMID:25750153

  9. Level II scour analysis for Bridge 38 (CONCTH00060038) on Town Highway 6, crossing the Moose River, Concord, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    Contraction scour for all modelled flows ranged from 0.1 to 3.1 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge. Abutment scour at the left abutment ranged from 10.4 to 12.5 ft with the worst-case occurring at the 500-year discharge. Abutment scour at the right abutment ranged from 25.3 to 27.3 ft with the worst-case occurring at the incipient-overtopping discharge. The worst-case total scour also occurred at the incipient-overtopping discharge. The incipient-overtopping discharge was in between the 100- and 500-year discharges. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  10. Level II scour analysis for Bridge 3 (BRIDTH000100003) on Town Highway 1, crossing Dailey Hollow Branch, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Song, Donald L.

    1996-01-01

    Total scour at a highway crossing is comprised of three components: 1) long-term aggradation or degradation; 2) contraction scour (due to reduction in flow area caused by a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute scour depths for contraction and local scour and a summary of the results follows. Contraction scour for all modelled flows ranged from 0.6 ft to 1.3 ft and the worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.7 ft to 12.2 ft and the worst-case abutment scour occurred at the 500-year discharge. Scour depths and depths to armoring are summarized on p. 14 in the section titled “Scour Results”. Scour elevations, based on the calculated depths are presented in tables 1 and 2; a graph of the scour elevations is presented in figure 8 Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. For all scour presented in this report, “the scour depths adopted [by VTAOT] may differ from the equation values based on engineering judgement” (Richardson and others, 1993, p. 21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, including historical performance during flood events, the geomorphic assessment, and the results of the hydraulic analyses, must be considered to properly assess the validity of abutment scour results.

  11. Contributions of DNA interstrand cross-links to aging of cells and organisms

    PubMed Central

    Grillari, Johannes; Katinger, Hermann; Voglauer, Regina

    2007-01-01

    Impaired DNA damage repair, especially deficient transcription-coupled nucleotide excision repair, leads to segmental progeroid syndromes in human patients as well as in rodent models. Furthermore, DNA double-strand break signalling has been pinpointed as a key inducer of cellular senescence. Several recent findings suggest that another DNA repair pathway, interstrand cross-link (ICL) repair, might also contribute to cell and organism aging. Therefore, we summarize and discuss here that (i) systemic administration of anti-cancer chemotherapeutics, in many cases DNA cross-linking drugs, induces premature progeroid frailty in long-term survivors; (ii) that ICL-inducing 8-methoxy-psoralen/UVA phototherapy leads to signs of premature skin aging as prominent long-term side effect and (iii) that mutated factors involved in ICL repair like ERCC1/XPF, the Fanconi anaemia proteins, WRN and SNEV lead to reduced replicative life span in vitro and segmental progeroid syndromes in vivo. However, since ICL-inducing drugs cause damage different from ICL and since all currently known ICL repair factors work in more than one pathway, further work will be needed to dissect the actual contribution of ICL damage to aging. PMID:18083760

  12. Assessment of parental contribution and effective population size from a 3×3 diallel cross of clam Meretrix meretrix

    NASA Astrophysics Data System (ADS)

    Dai, Ping; Wang, Hongxia; Liu, Baozhong

    2014-03-01

    Unbalanced parental contribution and small effective population size ( N e) are common issues during the artificial breeding of marine bivalves. The impact of hatchery-spawning practices on parental contribution, effective population size, the N e/ N ratio, and genetic diversity are largely unknown. To address this, we conducted a parentage analysis on a complete 3×3 diallel cross of clam M eretrix meretrix using eight microsatellite markers. The genetic diversity of the parents was higher than that of their respective offspring in most crosses (8/9). Sires or dams from the same family contributed unequally to the pool of offspring from a particular cross, and the same parent clam exhibited large variation in parental contribution among different crosses. The variance in male contribution was higher than that of the female contribution in most crosses, suggesting that male contribution was more skewed than for females. The N e/ N ratio for nine crosses ranged from 0.58 to 0.86. There was no linear relationship between the sex ratio and the N e/ N ratio ( P > 0.05). Moreover, a sex ratio closer to one-to-one does not necessarily mean a larger effective population size. A solution to small effective population size in commercial breeding programs is increasing broodstock numbers and attempting to maintain a balanced sex ratio.

  13. Computationally predicted IgE epitopes of walnut allergens contribute to cross-reactivity with peanuts

    PubMed Central

    Maleki, Soheila J.; Teuber, Suzanne S.; Cheng, Hsiaopo; Chen, Deliang; Comstock, Sarah S.; Ruan, Sanbao; Schein, Catherine H.

    2011-01-01

    Background Cross reactivity between peanuts and tree nuts implies that similar IgE epitopes are present in their proteins. Objective To determine whether walnut sequences similar to known peanut IgE binding sequences, according to the property distance (PD) scale implemented in the Structural Database of Allergenic Proteins (SDAP), react with IgE from sera of patients with allergy to walnut and/or peanut. Methods Patient sera were characterized by Western blotting for IgE-binding to nut protein extracts, and to peptides from walnut and peanut allergens, similar to known peanut epitopes as defined by low PD values, synthesized on membranes. Competitive ELISA was used to show that peanut and predicted walnut epitope sequences compete with purified Ara h 2 for binding to IgE in serum from a cross-reactive patient. Results Sequences from the vicilin walnut allergen Jug r 2 which had low PD values to epitopes of the peanut allergen Ara h 2, a 2s-albumin, bound IgE in sera from five patients who reacted to either walnut, peanut or both. A walnut epitope recognized by 6 patients mapped to a surface-exposed region on a model of the N-terminal pro-region of Jug r 2. A predicted walnut epitope competed for IgE binding to Ara h 2 in serum as well as the known IgE epitope from Ara h 2. Conclusions Sequences with low PD value (<8.5) to known IgE epitopes could contribute to cross-reactivity between allergens. This further validates the PD scoring method for predicting cross-reactive epitopes in allergens. PMID:21883278

  14. Orientation of spin-labeled light chain-2 exchanged onto myosin cross-bridges in glycerinated muscle fibers.

    PubMed Central

    Hambly, B; Franks, K; Cooke, R

    1991-01-01

    Electron paramagnetic resonance (EPR) spectroscopy has been used to study the angular distribution of a spin label attached to rabbit skeletal muscle myosin light chain 2. A cysteine reactive spin label, 3-(5-fluoro-2,4-dinitroanilino)-2,2,5,5- tetramethyl-1-pyrrolidinyloxy (FDNA-SL) was bound to purified LC2. The labeled LC2 was exchanged into glycerinated muscle fibers and into myosin and its subfragments. Analysis of the spectra of labeled fibers in rigor showed that the probe was oriented with respect to the fiber axis, but that it was also undergoing restricted rotations. The motion of the probe could be modeled assuming rapid rotational diffusion (rotational correlation time faster than 5 ns) within a "cone" whose full width was 70 degrees. Very different spectra of rigor fibers were obtained with the fiber oriented parallel and perpendicular to the magnetic field, showing that the centroid of each cone had the same orientation for all myosin heads, making an angle of approximately 74 degrees to the fiber axis. Binding of light chains or labeled myosin subfragment-1 to ion exchange heads immobilized the probes, showing that most of the motion of the probe arose from protein mobility and not from mobility of the probe relative to the protein. Relaxed labeled fibers produced EPR spectra with a highly disordered angular distribution, consistent with myosin heads being detached from the thin filament and undergoing large angular motions. Addition of pyrophosphate, ADP, or an ATP analogue (AMPPNP), in low ionic strength buffer where these ligands do not dissociate cross-bridges from actin, failed to perturb the rigor spectrum. Applying static strains as high as 0.16 N/mm2 to the labeled rigor fibers also failed to change the orientation of the spin label. Labeled light chain was exchanged into myosin subfragment-1 (S1) and the labeled S1 was diffused into fibers. EPR spectra of these fibers had a component similar to that seen in the spectra of fibers into which

  15. Real-virtual contributions to the inclusive Higgs cross-section at N3LO

    NASA Astrophysics Data System (ADS)

    Anastasiou, Charalampos; Duhr, Claude; Dulat, Falko; Herzog, Franz; Mistlberger, Bernhard

    2013-12-01

    We compute the contributions to the N3LO inclusive Higgs boson cross-section from the square of one-loop amplitudes with a Higgs boson and three QCD partons as external states. Our result is a Taylor expansion in the dimensional regulator ɛ, where the coefficients of the expansion are analytic functions of the ratio of the Higgs boson mass and the partonic center of mass energy and they are valid for arbitrary values of this ratio. We also perform a threshold expansion around the limit of soft-parton radiation in the final state. The expressions for the coefficients of the threshold expansion are valid for arbitrary values of the dimension. As a by-product of the threshold expansion calculation, we have developed a soft expansion method at the integrand level by identifying the relevant soft and collinear regions for the loop-momentum.

  16. Cross-border contributions to obesity research and interventions: a review of Canadian and American occupational therapy contributions.

    PubMed

    Forhan, Mary; Gill, Simone

    2013-04-01

    This paper identifies the contributions of Canadian and American occupational therapists to the empirical discourse on obesity. This scoping study includes an independent review of the published literature followed by a series of meetings during which key themes and contributions were categorized. The Person, Environment, Occupation, and Performance Model (Baum & Christiansen, 2005) was used to organize the themes reported in the literature. Although occupational therapists contribute to knowledge about body systems and functions as well as activity limitations and participation restrictions for persons with obesity, the majority of work has a focus on the environment and the person, with limited attention to occupation. Occupational therapy practitioners and researchers are contributing in areas valued in obesity research and practice but can do more to promote consideration of the interaction of personal, environmental, and occupational factors which may cause obesity or contribute to the participation in everyday living for persons with obesity. PMID:23855571

  17. Crossing the Bridge to Higher Mathematics: Using a Modified Moore Approach to Assist Students Transitioning to Higher Mathematics

    ERIC Educational Resources Information Center

    McLoughlin, M. Padraig M. M.

    2008-01-01

    The author of this paper submits that a mathematics student needs to learn to conjecture and prove or disprove said conjecture. Ergo, the purpose of the paper is to submit the thesis that learning requires doing; only through inquiry is learning achieved, and hence this paper proposes a programme of use of a modified Moore method in a Bridge to…

  18. Helping Children Cross Cultural Boundaries in the Borderlands: Arts Program at Freese Elementary in San Diego Creates Cultural Bridges

    ERIC Educational Resources Information Center

    Brouillette, Liane; Jennings, Lynne

    2010-01-01

    This article describes the unique multicultural arts program that has developed at Freese Elementary School, located only 20 minutes from the United States-Mexico border, in the southeastern corner of the San Diego Unified School District. The Arts and Culture Magnet Program at Freese grew out of the need build bridges in a neighborhood where…

  19. 77 FR 38881 - Notice of Final Federal Agency Actions on Proposed Two New Ohio River Bridge Crossings in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... connection between KY 841 (Gene Snyder Freeway) in eastern Jefferson County, Kentucky and SR 265 in eastern... connection between KY 841 (Gene Snyder Freeway) in eastern Jefferson County, Kentucky and SR 265 in eastern... River Bridge and approach roadways connecting the Gene Snyder Freeway (KY 841) in Kentucky to the...

  20. Three-body collision contributions to recombination and collision-induced dissociation. 1: Cross sections

    SciTech Connect

    Pack, R.T.; Walker, R.B.; Kendrick, B.K.

    1998-04-10

    Atomic and molecular recombination and collision-induced dissociation (CID) reactions comprise two of the most fundamental types of chemical reactions. They are important in all gas phase chemistry; for example, about half of the 196 reactions identified as important in combustion chemistry are recombination or CID reactions. Many of the current chemical kinetics textbooks and kinetics papers treat atomic and molecular recombination and CID as occurring only via sequences of two-body collisions. Actually, there is considerable evidence from experiment and classical trajectory calculations for contributions by true three-body collisions to the recombination of atomic and diatomic radicals, and that evidence is reviewed. Then, an approximate quantum method treating both two-body and three-body collisions simultaneously and on equal footing is used to calculate cross sections for the reaction Ne{sub 2} + H {rightleftharpoons} Ne + Ne + H. The results provide clear quantum evidence that direct three-body collisions do contribute significantly to recombination and CID.

  1. Contributions of a hydrogen bond/salt bridge network to the stability of secondary and tertiary structure in lambda repressor.

    PubMed Central

    Marqusee, S.; Sauer, R. T.

    1994-01-01

    In the N-terminal domain of lambda repressor, the Asp 14 side chain forms an intrahelical, hydrogen bond/salt bridge with the Arg 17 side chain and a tertiary hydrogen bond with the Ser 77 side chain. By measuring the stabilities to urea denaturation of the wild-type N-terminal domain and variants containing single, double, and triple alanine substitutions at positions 14, 17, and 77, the side-chain interaction energies, the coupling energy between interactions, and the intrinsic effects of each wild-type side chain on protein stability have been estimated. These studies indicate that the Asp 14-Arg 17 and Asp 14-Ser 77 interactions are stabilizing by roughly 0.8 and 1.5 kcal/mol, respectively, but that Asp 14, by itself, is destabilizing by roughly 0.9 kcal/mol. We also show that a peptide model of alpha-helix 1, which contains Asp 14 and Arg 17, forms a reasonably stable, monomeric helix in solution and responds to alanine mutations at positions 14 and 17 in the fashion expected from the intact protein studies. These studies suggest that it is possible to view the stability effects of mutations in intact proteins in a hierarchical fashion, with the stability of units of secondary structure being distinguishable from the stability of tertiary structure. PMID:7756981

  2. Matrix-grain-bridging contributions to the toughness of SiC composites with alumina-coated SiC platelets

    SciTech Connect

    Cao, J.J.; He, Y.; MoberlyChan, W.J.; De Jonghe, L.C. |

    1996-05-01

    Silicon carbide composites were fabricated through the incorporation of alumina-coated SiC platelets into a SiC matrix. Mechanical properties were evaluated in direct comparison with a commercial Hexoloy SiC. The fracture toughness of the composite, with a fine grained {beta}-SiC matrix, was twice that of the commercial material. The alumina-coating on the platelets provided a weak interface to promote crack deflection and platelet bridging, as well as easing densification of the composites. On the other hand, a three-fold increase in fracture toughness (9.1 MPa {radical}m) of an in situ toughened monolithic SiC was achieved by processing at higher temperatures, promoting the {beta}-to-{alpha} phase transformation and forming a microstructure containing high-aspect-ration plate-shaped grains. Efforts were made to combine the effects of coated-platelets reinforcement and in situ toughening in the matrix. Moderate high toughness (8 MPa {radical}m) was achieved by coupled toughening. The contribution of matrix-grain-bridging, however, was limited by the processing temperature at which the oxide coating was stable.

  3. Impact of cross-tie design on the in-plane stiffness and local mode formation of cable networks on cable-stayed bridges

    NASA Astrophysics Data System (ADS)

    Ahmad, Javaid; Cheng, Shaohong; Ghrib, Faouzi

    2016-02-01

    Suppressing unfavorable stay cable vibrations using cross-ties is becoming more popular on cable-stayed bridges though the mechanics of the formed cable network is yet fully understood. In practice, the main task in designing cross-ties or cable networks is to choose the cross-tie installation location, stiffness and number based on the main cable properties in the network. To have a more comprehensive picture of how to choose these design parameters to achieve higher in-plane network stiffness while minimizing the number of excited local modes, it is imperative to examine dynamic behavior of cable networks with general configurations. In the current study, an analytical model of a general cable network consisting of multiple main cables interconnected by multiple lines of transverse flexible cross-ties will be developed. A new term, defined as the local mode cluster, will be introduced to assess the severity of local mode excitation. Criteria for identifying the presence of local mode cluster will be proposed. A parametric study will be conducted to evaluate the impact of cross-tie installation location, stiffness and number on the network modal response. Results obtained from the present study will provide deeper insight into the selection of these system parameters to achieve the combined benefits of increasing network in-plane stiffness and minimizing the excitation of local modes.

  4. Alterations at the Cross-Bridge Level Are Associated with a Paradoxical Gain of Muscle Function In Vivo in a Mouse Model of Nemaline Myopathy

    PubMed Central

    Gineste, Charlotte; Ottenheijm, Coen; Le Fur, Yann; Banzet, Sébastien; Pecchi, Emilie; Vilmen, Christophe; Cozzone, Patrick J.; Koulmann, Nathalie; Hardeman, Edna C.; Bendahan, David; Gondin, Julien

    2014-01-01

    Nemaline myopathy is the most common disease entity among non-dystrophic skeletal muscle congenital diseases. The first disease causing mutation (Met9Arg) was identified in the gene encoding α-tropomyosinslow gene (TPM3). Considering the conflicting findings of the previous studies on the transgenic (Tg) mice carrying the TPM3Met9Arg mutation, we investigated carefully the effect of the Met9Arg mutation in 8–9 month-old Tg(TPM3)Met9Arg mice on muscle function using a multiscale methodological approach including skinned muscle fibers analysis and in vivo investigations by magnetic resonance imaging and 31-phosphorus magnetic resonance spectroscopy. While in vitro maximal force production was reduced in Tg(TPM3)Met9Arg mice as compared to controls, in vivo measurements revealed an improved mechanical performance in the transgenic mice as compared to the former. The reduced in vitro muscle force might be related to alterations occuring at the cross-bridges level with muscle-specific underlying mechanisms. In vivo muscle improvement was not associated with any changes in either muscle volume or energy metabolism. Our findings indicate that TPM3(Met9Arg) mutation leads to a mild muscle weakness in vitro related to an alteration at the cross-bridges level and a paradoxical gain of muscle function in vivo. These results clearly point out that in vitro alterations are muscle-dependent and do not necessarily translate into similar changes in vivo. PMID:25268244

  5. Synthesis, Cu(II) complexation, 64Cu-labeling and biological evaluation of cross-bridged cyclam chelators with phosphonate pendant arms†

    PubMed Central

    Ferdani, Riccardo; Stigers, Dannon J.; Fiamengo, Ashley L.; Wei, Lihui; Li, Barbara T. Y.; Golen, James A.; Rheingold, Arnold L.; Weisman, Gary R.; Wong, Edward H.; Anderson, Carolyn J.

    2012-01-01

    A new class of cross-bridged cyclam-based macrocycles featuring phosphonate pendant groups has been developed. 1,4,8,11-tetraazacyclotetradecane-1,8-di(methanephosphonic acid) (CB-TE2P, 1) and 1,4,8,11-tetraazacyclotetradecane-1-(methanephosphonic acid)-8-(methanecarboxylic acid) (CB-TE1A1P, 2) have been synthesized and have been shown to readily form neutral copper (II) complexes at room temperature as the corresponding dianions. Both complexes showed high kinetic inertness to demetallation and crystal structures confirmed complete encapsulation of copper (II) ion within each macrocycle’s cleft-like structure. Unprecedented for cross-bridged cyclam derivatives, both CB-TE2P (1) and CB-TE1A1P (2) can be radiolabeled with 64Cu at room temperature in less than 1 hour with specific activities >1mCi/μg. The in vivo behavior of both 64Cu-CB-TE2P and 64Cu-CB-TE1A1P were investigated through biodistribution studies using healthy, male, Lewis rats. Both new compounds showed rapid clearance with similar or lower accumulation in non-target organs/tissues when compared to other copper chelators including CB-TE2A, NOTA and Diamsar. PMID:22170043

  6. Mechanical study of rat soleus muscle using caged ATP and X-ray diffraction: high ADP affinity of slow cross-bridges.

    PubMed Central

    Horiuti, K; Yagi, N; Takemori, S

    1997-01-01

    1. The cross-bridges in slow- and fast-twitch fibres (taken, respectively, from soleus and psoas muscles of rats) were examined in mechanical experiments using caged ATP and X-ray diffraction, to compare their binding of ATP and ADP. 2. Caged ATP was photolysed in rigor fibres. When ADP was removed from pre-photolysis fibres, the initial relaxation (+/- Ca2+) in soleus was as fast as that in psoas fibres, whereas the subsequent contraction (+Ca2+) was slower in soleus than in psoas. The ATPase rate during the steady-state contraction was also slower in soleus fibres. 3. When ADP was added to pre-photolysis fibres (+/- Ca2+), tension developed even in the initial phase, the overall tension development being biphasic. Both initial and late components of the Ca(2+)-free contraction were enhanced when ADP was added before photolysis, although pre-photolysis ADP was not a prerequisite for the late component. The effect of ADP was greater in soleus than in psoas fibres. Static experiments on rigor fibres revealed a higher ADP affinity in soleus fibres. 4. The intensity of the actin layer-line from ADP rigor soleus fibres decreased rapidly on photorelease of ATP. We conclude that, despite the tight ADP binding of the soleus cross-bridge, its isometric reaction is not rate limited by the 'off' rate of ADP. PMID:9263922

  7. Level II scour analysis for Bridge 42 (RANDVT00120042) on State Highway 12, crossing Third Branch White River, Randolph, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Weber, Matthew A.

    1996-01-01

    bridge consisting of four concrete spans. The maximum span length is 57 ft. (Vermont Agency of Transportation, written commun., July 29, 1994). The bridge is supported by vertical, concrete abutments and three concrete piers. The toe of the left abutment is at the channel edge. The toe of the right abutment is set back on the right over-bank. The roadway centerline on the structure has a slight horizontal curve; however, the main channel is skewed approximately 5 degrees to the bridge. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. The scour analysis results are presented in tables 1 and 2 and a graph of the scour depths is presented in figure 8.

  8. Regulatory Cross-Talks and Cascades in Rice Hormone Biosynthesis Pathways Contribute to Stress Signaling

    PubMed Central

    Deb, Arindam; Grewal, Rumdeep K.; Kundu, Sudip

    2016-01-01

    Crosstalk among different hormone signaling pathways play an important role in modulating plant response to both biotic and abiotic stress. Hormone activity is controlled by its bio-availability, which is again influenced by its biosynthesis. Thus, independent hormone biosynthesis pathways must be regulated and co-ordinated to mount an integrated response. One of the possibilities is to use cis-regulatory elements to orchestrate expression of hormone biosynthesis genes. Analysis of CREs, associated with differentially expressed hormone biosynthesis related genes in rice leaf under Magnaporthe oryzae attack and drought stress enabled us to obtain insights about cross-talk among hormone biosynthesis pathways at the transcriptional level. We identified some master transcription regulators that co-ordinate different hormone biosynthesis pathways under stress. We found that Abscisic acid and Brassinosteroid regulate Cytokinin conjugation; conversely Brassinosteroid biosynthesis is affected by both Abscisic acid and Cytokinin. Jasmonic acid and Ethylene biosynthesis may be modulated by Abscisic acid through DREB transcription factors. Jasmonic acid or Salicylic acid biosynthesis pathways are co-regulated but they are unlikely to influence each others production directly. Thus, multiple hormones may modulate hormone biosynthesis pathways through a complex regulatory network, where biosynthesis of one hormone is affected by several other contributing hormones. PMID:27617021

  9. Regulatory Cross-Talks and Cascades in Rice Hormone Biosynthesis Pathways Contribute to Stress Signaling.

    PubMed

    Deb, Arindam; Grewal, Rumdeep K; Kundu, Sudip

    2016-01-01

    Crosstalk among different hormone signaling pathways play an important role in modulating plant response to both biotic and abiotic stress. Hormone activity is controlled by its bio-availability, which is again influenced by its biosynthesis. Thus, independent hormone biosynthesis pathways must be regulated and co-ordinated to mount an integrated response. One of the possibilities is to use cis-regulatory elements to orchestrate expression of hormone biosynthesis genes. Analysis of CREs, associated with differentially expressed hormone biosynthesis related genes in rice leaf under Magnaporthe oryzae attack and drought stress enabled us to obtain insights about cross-talk among hormone biosynthesis pathways at the transcriptional level. We identified some master transcription regulators that co-ordinate different hormone biosynthesis pathways under stress. We found that Abscisic acid and Brassinosteroid regulate Cytokinin conjugation; conversely Brassinosteroid biosynthesis is affected by both Abscisic acid and Cytokinin. Jasmonic acid and Ethylene biosynthesis may be modulated by Abscisic acid through DREB transcription factors. Jasmonic acid or Salicylic acid biosynthesis pathways are co-regulated but they are unlikely to influence each others production directly. Thus, multiple hormones may modulate hormone biosynthesis pathways through a complex regulatory network, where biosynthesis of one hormone is affected by several other contributing hormones. PMID:27617021

  10. Bridge permeameter

    DOEpatents

    Graf, Darin C.; Warpinski, Norman R.

    1996-01-01

    A system for single-phase, steady-state permeability measurements of porous rock utilizes a fluid bridge arrangement analogous to a Wheatstone bridge. The arms of the bridge contain the sample and calibrated flow resistors.

  11. Screening corrections for the interference contributions to the electron and positron scattering cross sections from polyatomic molecules

    NASA Astrophysics Data System (ADS)

    Blanco, Francisco; Ellis-Gibbings, Lilian; García, Gustavo

    2016-02-01

    An improvement of the screening-corrected Additivity Rule (SCAR) is proposed for calculating electron and positron scattering cross sections from polyatomic molecules within the independent atom model (IAM), following the analysis of numerical solutions to the three-dimensional Lippmann-Schwinger equation for multicenter potentials. Interference contributions affect all the considered energy range (1-300 eV); the lower energies where the atomic screening is most effective and higher energies, where interatomic distances are large compared to total cross sections and electron wavelengths. This correction to the interference terms provides a significant improvement for both total and differential elastic cross sections at these energies.

  12. Barriers and Bridges to Positive Cross-Ethnic Relations: African American and White Parent Socialization Beliefs and Practices.

    ERIC Educational Resources Information Center

    Hamm, Jill V.

    2001-01-01

    Using interviews and focus groups, lower and middle socioeconomic status (SES) African American parents and middle SES white parents discussed their objectives regarding cross-ethnic relations and how they helped their children forge positive cross-ethnic relations. The groups relied on different methods to promote socialization. Parents' efforts…

  13. Impact of Cross-Tie Properties on the Modal Behavior of Cable Networks on Cable-Stayed Bridges.

    PubMed

    Ahmad, Javaid; Cheng, Shaohong; Ghrib, Faouzi

    2015-01-01

    Dynamic behaviour of cable networks is highly dependent on the installation location, stiffness, and damping of cross-ties. Thus, these are the important design parameters for a cable network. While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed. To comprehend our knowledge of mechanics associated with cable networks, in the current study, an analytical model of a cable network will be proposed by taking into account both cross-tie stiffness and damping. In addition, the damping property of main cables in the network will also be considered in the formulation. This would allow exploring not only the effectiveness of a cross-tie design on enhancing the in-plane stiffness of a constituted cable network, but also its energy dissipation capacity. The proposed analytical model will be applied to networks with different configurations. The influence of cross-tie stiffness and damping on the modal response of various types of networks will be investigated by using the corresponding undamped rigid cross-tie network as a reference base. Results will provide valuable information on the selection of cross-tie properties to achieve more effective cable vibration control. PMID:26167539

  14. Impact of Cross-Tie Properties on the Modal Behavior of Cable Networks on Cable-Stayed Bridges

    PubMed Central

    Ahmad, Javaid; Cheng, Shaohong; Ghrib, Faouzi

    2015-01-01

    Dynamic behaviour of cable networks is highly dependent on the installation location, stiffness, and damping of cross-ties. Thus, these are the important design parameters for a cable network. While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed. To comprehend our knowledge of mechanics associated with cable networks, in the current study, an analytical model of a cable network will be proposed by taking into account both cross-tie stiffness and damping. In addition, the damping property of main cables in the network will also be considered in the formulation. This would allow exploring not only the effectiveness of a cross-tie design on enhancing the in-plane stiffness of a constituted cable network, but also its energy dissipation capacity. The proposed analytical model will be applied to networks with different configurations. The influence of cross-tie stiffness and damping on the modal response of various types of networks will be investigated by using the corresponding undamped rigid cross-tie network as a reference base. Results will provide valuable information on the selection of cross-tie properties to achieve more effective cable vibration control. PMID:26167539

  15. Horizontal Cross Bracing Detail, Vertical Cross Bracing Detail, Horizontal Cross ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Horizontal Cross Bracing Detail, Vertical Cross Bracing Detail, Horizontal Cross Bracing Joint, Vertical Cross Bracing End Detail - Ceylon Covered Bridge, Limberlost Park, spanning Wabash River at County Road 900 South, Geneva, Adams County, IN

  16. Level II scour analysis for Bridge 10 (WNDHTH00020010) on Town Highway 2, crossing the Middle Branch of the Williams River, Windham, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Wild, Emily C.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure WNDHTH00020010 on Town Highway 2 crossing the Middle Branch Williams River, Windham, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province in south central Vermont. The 1.44-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the predominate surface cover upstream of the bridge is pasture on the left bank and forest on the right bank. Downstream of the bridge the surface cover consists of forest on the right bank and grass on the left bank. In the study area, the Middle Branch Williams River has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 28 ft and an average bank height of 5 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 61.4 mm (0.201 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 22, 1996, indicated that the reach was stable. The Town Highway 2 crossing of the Middle Branch Williams River is a 25-ft-long, two-lane bridge consisting of one 22-foot concrete slab span (Vermont Agency of Transportation, written communication, March 31, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 60 degrees to the opening while the opening

  17. Conversational Moves That Matter: Bridging Learning Outcomes and Patterns of Speech in Informal Cross-Organizational Conversations Among Top-Level Leaders

    ERIC Educational Resources Information Center

    Hartung, Kyle John; Wilson, Daniel Gray

    2016-01-01

    Cross-organizational "learning conversations" are an important source of informal learning among professionals, though little is known about whether specific characteristics of conversational interaction contribute to different learning outcomes in such conversations. This mixed-methods study examined the relationship between…

  18. Level II scour analysis for bridge 35 (BURKTH00310035) on Town Highway 31, crossing the West Branch Passumpsic River, Burke, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Degnan, James R.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BURKTH00310035 on Town Highway 31 crossing the West Branch Passumpsic River, Burke, Vermont (figures 1-8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (FHWA, 1993). Results of a Level I scour investigation also are included in appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in appendix D.

  19. Synthesis and structural characterization of the individual diastereoisomers of a cross-stapled alkene-bridged nisin DE-ring mimic.

    PubMed

    Slootweg, Jack C; Kemmink, Johan; Liskamp, Rob M J; Rijkers, Dirk T S

    2013-11-21

    Herein, we describe the synthesis, structural characterization, and synthetic use as an advanced intermediate of a cross-stapled alkene-bridged hexapeptide to mimic the DE-ring of the lantibiotic nisin. The linear precursor was cyclized by ring-closing metathesis to give the correctly folded bicyclic hexapeptide in a single step, and the four individual diastereoisomers were isolated, structurally assigned and characterized by HPLC, NMR and MS, respectively. The bicyclic hexapeptide was used as a versatile advanced synthon and was modified at its C- and N-terminus, among others, with an azide moiety to access a building block suitable for Cu(I)-catalyzed alkyne-azide cycloaddition-based ligation reactions. PMID:24081149

  20. Structural basis for the in situ Ca2+ sensitization of cardiac troponin C by positive feedback from force-generating myosin cross-bridges

    PubMed Central

    Rieck, Daniel C.; Li, King-Lun; Ouyang, Yexin; Solaro, R. John; Dong, Wen-Ji

    2013-01-01

    The in situ structural coupling between the cardiac troponin (cTn) Ca2+-sensitive regulatory switch (CRS) and strong myosin cross-bridges was investigated using Förster resonance energy transfer (FRET). The double cysteine mutant cTnC(T13C/N51C) was fluorescently labeled with the FRET pair 5-(iodoacetamidoethyl)aminonaphthelene-1-sulfonic acid (IAEDENS) and N-(4-dimethylamino-3,5-dinitrophenyl)maleimide (DDPM) and then incorporated into detergent skinned left ventricular papillary fiber bundles. Ca2+ titrations of cTnC(T13C/N51C)AEDENS/DDPM-reconstituted fibers showed that the Ca2+-dependence of the opening of the N-domain of cTnC (N-cTnC) statistically matched the force–Ca2+ relationship. N-cTnC opening still occurred steeply during Ca2+ titrations in the presence of 1 mM vanadate, but the maximal extent of ensemble-averaged N-cTnC opening and the Ca2+-sensitivity of the CRS were significantly reduced. At nanomolar, resting Ca2+ levels, treatment with ADP•Mg in the absence of ATP caused a partial opening of N-cTnC. During subsequent Ca2+ titrations in the presence of ADP•Mg and absence of ATP, further N-cTnC opening was stimulated as the CRS responded to Ca2+ with increased Ca2+-sensitivity and reduced steepness. These findings supported our hypothesis here that strong cross-bridge interactions with the cardiac thin filament exert a Ca2+-sensitizing effect on the CRS by stabilizing the interaction between the exposed hydrophobic patch of N-cTnC and the switch region of cTnI. PMID:23896515

  1. Structural basis for the in situ Ca(2+) sensitization of cardiac troponin C by positive feedback from force-generating myosin cross-bridges.

    PubMed

    Rieck, Daniel C; Li, King-Lun; Ouyang, Yexin; Solaro, R John; Dong, Wen-Ji

    2013-09-15

    The in situ structural coupling between the cardiac troponin (cTn) Ca(2+)-sensitive regulatory switch (CRS) and strong myosin cross-bridges was investigated using Förster resonance energy transfer (FRET). The double cysteine mutant cTnC(T13C/N51C) was fluorescently labeled with the FRET pair 5-(iodoacetamidoethyl)aminonaphthelene-1-sulfonic acid (IAEDENS) and N-(4-dimethylamino-3,5-dinitrophenyl)maleimide (DDPM) and then incorporated into detergent skinned left ventricular papillary fiber bundles. Ca(2+) titrations of cTnC(T13C/N51C)AEDENS/DDPM-reconstituted fibers showed that the Ca(2+)-dependence of the opening of the N-domain of cTnC (N-cTnC) statistically matched the force-Ca(2+) relationship. N-cTnC opening still occurred steeply during Ca(2+) titrations in the presence of 1mM vanadate, but the maximal extent of ensemble-averaged N-cTnC opening and the Ca(2+)-sensitivity of the CRS were significantly reduced. At nanomolar, resting Ca(2+) levels, treatment with ADP·Mg in the absence of ATP caused a partial opening of N-cTnC. During subsequent Ca(2+) titrations in the presence of ADP·Mg and absence of ATP, further N-cTnC opening was stimulated as the CRS responded to Ca(2+) with increased Ca(2+)-sensitivity and reduced steepness. These findings supported our hypothesis here that strong cross-bridge interactions with the cardiac thin filament exert a Ca(2+)-sensitizing effect on the CRS by stabilizing the interaction between the exposed hydrophobic patch of N-cTnC and the switch region of cTnI. PMID:23896515

  2. Level II scour analysis for Bridge 46 (CHELTH00680046) on Town Highway 68, crossing the First Branch of the White River, Chelsea, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Song, Donald L.

    1996-01-01

    Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0.9 to 2.6 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 14.3 to 24.0 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. The left abutment sits atop a bedrock outcrop. The results of the calculated scour depths will be limited by the bedrock. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  3. Muscle weakness in TPM3-myopathy is due to reduced Ca2+-sensitivity and impaired acto-myosin cross-bridge cycling in slow fibres.

    PubMed

    Yuen, Michaela; Cooper, Sandra T; Marston, Steve B; Nowak, Kristen J; McNamara, Elyshia; Mokbel, Nancy; Ilkovski, Biljana; Ravenscroft, Gianina; Rendu, John; de Winter, Josine M; Klinge, Lars; Beggs, Alan H; North, Kathryn N; Ottenheijm, Coen A C; Clarke, Nigel F

    2015-11-15

    Dominant mutations in TPM3, encoding α-tropomyosinslow, cause a congenital myopathy characterized by generalized muscle weakness. Here, we used a multidisciplinary approach to investigate the mechanism of muscle dysfunction in 12 TPM3-myopathy patients. We confirm that slow myofibre hypotrophy is a diagnostic hallmark of TPM3-myopathy, and is commonly accompanied by skewing of fibre-type ratios (either slow or fast fibre predominance). Patient muscle contained normal ratios of the three tropomyosin isoforms and normal fibre-type expression of myosins and troponins. Using 2D-PAGE, we demonstrate that mutant α-tropomyosinslow was expressed, suggesting muscle dysfunction is due to a dominant-negative effect of mutant protein on muscle contraction. Molecular modelling suggested mutant α-tropomyosinslow likely impacts actin-tropomyosin interactions and, indeed, co-sedimentation assays showed reduced binding of mutant α-tropomyosinslow (R168C) to filamentous actin. Single fibre contractility studies of patient myofibres revealed marked slow myofibre specific abnormalities. At saturating [Ca(2+)] (pCa 4.5), patient slow fibres produced only 63% of the contractile force produced in control slow fibres and had reduced acto-myosin cross-bridge cycling kinetics. Importantly, due to reduced Ca(2+)-sensitivity, at sub-saturating [Ca(2+)] (pCa 6, levels typically released during in vivo contraction) patient slow fibres produced only 26% of the force generated by control slow fibres. Thus, weakness in TPM3-myopathy patients can be directly attributed to reduced slow fibre force at physiological [Ca(2+)], and impaired acto-myosin cross-bridge cycling kinetics. Fast myofibres are spared; however, they appear to be unable to compensate for slow fibre dysfunction. Abnormal Ca(2+)-sensitivity in TPM3-myopathy patients suggests Ca(2+)-sensitizing drugs may represent a useful treatment for this condition. PMID:26307083

  4. Crossing the Gap between Indigenous Worldview and Western Science: Millet Festival as a Bridge in the Teaching Module

    ERIC Educational Resources Information Center

    Chiang, Chia-Ling; Lee, Huei

    2015-01-01

    The worldview within indigenous people's traditional knowledge and western science can be a world of difference. In order to help indigenous students cross the gap and develop a sense of cultural identification. Taking Bunun, one of the Taiwanese indigenous tribes, as our subject, this study aims to develop a teaching module through Bunun's Millet…

  5. Bridging the Divide: Developing the Institutional Structures That Most Effectively Deliver Cross-Sectoral Education and Training.

    ERIC Educational Resources Information Center

    Wheelahan, Leesa

    Issues in developing the institutional structures to deliver cross-sectoral education and training were examined in a study of five Australian single-sector higher education institutions with various institutional arrangements with the vocational education and training (VET) sector and five dual-sector universities. Data were collected from the…

  6. Diversity and Similarity of Motor Function and Cross-Bridge Kinetics in Papillary Muscles of Transgenic Mice Carrying Myosin Regulatory Light Chain Mutations D166V and R58Q

    PubMed Central

    Wang, Li; Muthu, Priya; Szczesna-Cordary, Danuta; Kawai, Masataka

    2013-01-01

    Mechanical properties of skinned papillary muscle fibers from transgenic mice expressing familial hypertrophic cardiomyopathy associated mutations D166V and R58Q in myosin regulatory light chain were investigated. Elementary steps and the apparent rate constants of the cross-bridge cycle were characterized from the tension transients induced by sinusoidal length changes during maximal Ca2+ activation, together with ATP, ADP, and Pi studies. The tension-pCa relation was also tested in two sets of solutions with differing Pi and ionic strength. Our results showed that in both mutants, the fast apparent rate constant 2πc and the rate constants of the cross-bridge detachment step (k2) were smaller than those of wild type (WT), demonstrating the slower cross-bridge kinetics. D166V showed significantly smaller ATP (K1) and ADP (K0) association constants than WT, displaying weaker ATP binding and easier ADP release, whereas those of R58Q were not significantly different from WT. In tension-pCa study, both D166V and R58Q mutations exhibited increased Ca2+ sensitivity and less cooperativity. We conclude that, while the two FHC mutations have similar clinical manifestations and prognosis, some of the mechanical parameters of cross-bridges (K0, K1) are differently modified, whereas some others (Ca2+-sensitivity, cooperativity, k2) are similarly modified by these two FHC associated mutations. PMID:23727233

  7. Level II scour analysis for Bridge 25 (ROYATH00550025) on Town Highway 55, crossing Broad Brook, Royalton, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Weber, Matthew A.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.6 to 1.5 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge which was less than the 100-year discharge. Abutment scour ranged from 3.5 to 8.9 ft. The worst-case abutment scour occurred at the incipient road-overtopping discharge for the left abutment and at the 100-year discharge for the right abutment. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A crosssection of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  8. Level II scour analysis for Bridge 39 (TOPSTH00510039) on Town Highway 51, crossing Tabor Branch Waits River, Topsham, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Severance, Tim

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.4 ft. The worst-case contraction scour occurred at the maximum free surface flow discharge, which was less than the 100-year discharge. Abutment scour ranged from 4.8 to 8.0 ft. The worst-case abutment scour occurred at 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A crosssection of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  9. Level II scour analysis for Bridge 16 (GROTTH00170016) on Town Highway 17, crossing the Wells River, Groton, Vermont

    USGS Publications Warehouse

    Striker, L.K.; Ivanoff, M.A.

    1997-01-01

    Contraction scour for all modelled flows was 0 ft. Abutment scour ranged from 7.6 to 8.4 ft at the left abutment and from 9.9 to 14.8 ft at the right abutment. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A crosssection of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  10. 29. Historic photographer, photographer unknown, c. 1944. VIEW OF BRIDGE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. Historic photographer, photographer unknown, c. 1944. VIEW OF BRIDGE, LOOKING EAST FROM TOP OF WEST TOWER. SHEEP CROSSING BRIDGE. NOTE SWAY CABLES. - Verde River Sheep Bridge, Spanning Verde River (Tonto National Forest), Cave Creek, Maricopa County, AZ

  11. 11. Standing on westerly fender at edge of bridge looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Standing on westerly fender at edge of bridge looking easterly, showing horizontal beams for deck and cross beams (reflection of steel grating on deck). Also shows bridge guardrail. - Colusa Bridge, Spanning Sacramento River, Colusa, Colusa County, CA

  12. Level II scour analysis for Bridge 10 (CHESTH00030010) on Town Highway 3 (VT 35), crossing the South Branch of Williams River, Chester, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Hammond, Robert E.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure CHESTH00030010 on Town Highway 3 (VT 35) crossing the South Branch Williams River, Chester, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in southeastern Vermont. The 9.44-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest. In the study area, the South Branch Williams River has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 67 ft and an average bank height of 5 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 69.0 mm (0.226 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 26-27, 1996, indicated that the reach was stable. The Town Highway 3 (VT 35) crossing of the South Branch Williams River is a 69-foot-long, two-lane bridge consisting of one 67-foot steel-stringer span with a concrete deck (Vermont Agency of Transportation, written communication, August 23, 1994). The opening length of the structure parallel to the bridge face is 64.5 ft. The bridge is supported by vertical, concrete abutments with spill-through embankments. The channel is skewed approximately 50 degrees to the opening while the opening-skew-to-roadway is 30 degrees. The scour protection (spill

  13. Bathymetric and velocimetric surveys at highway bridges crossing the Missouri River between Kansas City and St. Louis, Missouri, April-May, 2013

    USGS Publications Warehouse

    Huizinga, Richard J.

    2014-01-01

    Bathymetric and velocimetric data were collected by the U.S. Geological Survey, in cooperation with the Missouri Department of Transportation, in the vicinity of 10 bridges at 9 highway crossings of the Missouri River between Lexington and Washington, Missouri, from April 22 through May 2, 2013. A multibeam echosounder mapping system was used to obtain channel-bed elevations for river reaches ranging from 1,640 to 1,840 feet longitudinally and extending laterally across the active channel between banks and spur dikes in the Missouri River during low- to moderate-flow conditions. These bathymetric surveys indicate the channel conditions at the time of the surveys and provide characteristics of scour holes that may be useful in the development of predictive guidelines or equations for scour holes. These data also may be useful to the Missouri Department of Transportation to assess the bridges for stability and integrity issues with respect to bridge scour during floods. Bathymetric data were collected around every pier that was in water, except those at the edge of water or in very shallow water (less than about 6 feet). Scour holes were present at most piers for which bathymetry could be obtained, except at piers on channel banks, near or embedded in lateral or longitudinal spur dikes, and on exposed bedrock outcrops. Scour holes observed at the surveyed bridges were examined with respect to depth and shape. Although exposure of parts of foundational support elements was observed at several piers, at most sites the exposure likely can be considered minimal compared to the overall substructure that remains buried in channel-bed material; however, there were several notable exceptions where the bed material thickness between the bottom of the scour hole and bedrock was less than 6 feet. Such substantial exposure of usually buried substructural elements may warrant special observation in future flood events. Previous bathymetric surveys had been done at all of the

  14. Level II scour analysis for Bridge 43 (CHESVT00110043) on State Highway 11, crossing the Middle Branch Williams River, Chester, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Burns, Ronda L.

    1997-01-01

    76-ft-long, two-lane bridge consisting of two 37-foot concrete Tee-beam spans (Vermont Agency of Transportation, written communication, March 29, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 35 degrees to the opening. The computed opening-skew-to-roadway was 30 degrees but the historical records indicate this angle is 25 degrees. Scour protection measures at the site consist of type-1 stone fill (less than 12 inches diameter) along the downstream banks and the upstream right wing wall. Type-2 (less than 36 inches diameter) stone fill protection is noted on the upstream and downstream left wingwalls and upstream along the left bank. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0.0 to 1.5 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.2 to 10.7 ft. The worst-case abutment scour occurred at the 500-year discharge for the right abutment. Pier scour ranged from 7.3 to 8.6 ft. The worst-case pier scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour

  15. Cross-Disciplinary Consultancy to Bridge Public Health Technical Needs and Analytic Developers: Asyndromic Surveillance Use Case

    PubMed Central

    Faigen, Zachary; Deyneka, Lana; Ising, Amy; Neill, Daniel; Conway, Mike; Fairchild, Geoffrey; Gunn, Julia; Swenson, David; Painter, Ian; Johnson, Lauren; Kiley, Chris; Streichert, Laura

    2015-01-01

    Introduction: We document a funded effort to bridge the gap between constrained scientific challenges of public health surveillance and methodologies from academia and industry. Component tasks are the collection of epidemiologists’ use case problems, multidisciplinary consultancies to refine them, and dissemination of problem requirements and shareable datasets. We describe an initial use case and consultancy as a concrete example and challenge to developers. Materials and Methods: Supported by the Defense Threat Reduction Agency Biosurveillance Ecosystem project, the International Society for Disease Surveillance formed an advisory group to select tractable use case problems and convene inter-disciplinary consultancies to translate analytic needs into well-defined problems and to promote development of applicable solution methods. The initial consultancy’s focus was a problem originated by the North Carolina Department of Health and its NC DETECT surveillance system: Derive a method for detection of patient record clusters worthy of follow-up based on free-text chief complaints and without syndromic classification. Results: Direct communication between public health problem owners and analytic developers was informative to both groups and constructive for the solution development process. The consultancy achieved refinement of the asyndromic detection challenge and of solution requirements. Participants summarized and evaluated solution approaches and discussed dissemination and collaboration strategies. Practice Implications: A solution meeting the specification of the use case described above could improve human monitoring efficiency with expedited warning of events requiring follow-up, including otherwise overlooked events with no syndromic indicators. This approach can remove obstacles to collaboration with efficient, minimal data-sharing and without costly overhead. PMID:26834939

  16. Crossing the Bridge: Foreign Language Students' Reciprocal Images in (Inter)Cultural Mediation between Portugal and Turkey

    ERIC Educational Resources Information Center

    Basílio, Daniel; Araújo e Sá, Maria Helena; Simões, Ana Raquel

    2016-01-01

    This study intends to highlight the role that Foreign Language Education (FLE), particularly in the Higher Education context, can play so as to contribute to the rapprochement of two distant and still mutually unknown countries such as Portugal and Turkey. In this sense, it ultimately aims at supporting the training of intercultural speakers,…

  17. Level II scour analysis for Bridge 33 (BRIDTH00050033) on Town Highway 5, crossing the North Branch Ottauquechee River, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Song, Donald L.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BRIDTH00050033 on town highway 5 crossing the North Branch Ottauquechee River, Bridgewater, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province of central Vermont in the town of Bridgewater. The 5.01-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the downstream banks are forested and the upstream banks have dense woody brush; the upstream right overbank is an open field. In the study area, the North Branch Ottauquechee River has an incised, sinuous channel with a slope of approximately 0.017 ft/ft, an average channel top width of 30 ft and an average channel depth of 3 ft. The predominant channel bed materials are gravel and cobble with a median grain size (D50) of 83.2 mm (0.273 ft). The geomorphic assessment at the time of the Level I and Level II site visit on November 3, 1994, indicated that the reach was stable. Also at the time of the site visit, there was considerable backwater at the bridge site due to a three foot tall beaver dam 40 feet downstream. The beaver dam was assumed destroyed by flood flow and was ignored in the analyses. The town highway 5 crossing of the North Branch Ottauquechee Riveris a 25-ft-long, onelane bridge consisting of one 23-foot steel-beam span with a timber deck (Vermont Agency of Transportation, written

  18. The effect of lattice spacing change on cross-bridge kinetics in chemically skinned rabbit psoas muscle fibers. I. Proportionality between the lattice spacing and the fiber width.

    PubMed Central

    Kawai, M; Wray, J S; Zhao, Y

    1993-01-01

    Chemically skinned rabbit psoas muscle fibers/bundles were osmotically compressed with a macromolecule dextran T-500 (0-16%, g/100 ml) at 20 degrees C, 200 mM ionic strength, and pH 7.0. The lattice spacing of psoas bundles was measured by equatorial x-ray diffraction studies during relaxation and after rigor induction, and the results were compared with the fiber width measurements by optical microscopy. The purpose of the present study is to determine whether fiber width is a reliable measure of the lattice spacing, and to determine the available spacing for myosin cross-bridges between the thick and thin filaments. We observed that both the lattice spacing and the fiber width decreased with an increase in the dextran concentration during relaxation or after rigor induction, and that the spacing and the fiber width were proportionately related. We further observed that, in the absence of dextran, the lattice spacing (and the fiber width) shrank on a relax-to-rigor transition, whereas in the presence of 16% dextran, the spacing expanded on a relax-to-rigor transition. The cross-over of these plots occurred at the 4-7% dextran concentration. During Ca activation, the fiber width shrank in the absence of dextran, and it slightly expanded in the presence of 14.4% dextran. The degree of expansion was not as large as in the relax-to-rigor transition, and the cross-over occurred at about 11% dextran concentration. We also carried out experiments with dextran T-40 and T-10 to determine the upper limit of the molecular weight that enters the lattice space. We found that the upper limit is about 20 kD. PMID:7679296

  19. Computationally predicted IgE epitopes of walnut allergens contribute to cross-reactivity with peanuts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cross reactivity between peanuts and tree nuts implies that similar IgE epitopes are present in their proteins. To determine whether walnut sequences similar to known peanut IgE binding sequences, according to the property distance (PD) scale implemented in the Structural Database of Allergenic Prot...

  20. Cross-Disciplinary Contributions to E-Learning Design: A Tripartite Design Model

    ERIC Educational Resources Information Center

    Hutchins, Holly M.; Hutchison, Dennis

    2008-01-01

    Purpose: The purpose of this paper is to review cross-disciplinary research on e-learning from workplace learning, educational technology, and instructional communication disciplines to identify relevant e-learning design principles. It aims to use these principles to propose an e-learning model that can guide the design of instructionally sound,…

  1. Bridge permeameter

    DOEpatents

    Graf, D.C.; Warpinski, N.R.

    1996-08-13

    A system is described for single-phase, steady-state permeability measurements of porous rock which utilizes a fluid bridge arrangement analogous to a Wheatstone bridge. The arms of the bridge contain the sample and calibrated flow resistors. 8 figs.

  2. Level II scour analysis for Bridge 38 (ANDOVT00110038) on State Route 11, crossing the Middle Branch Williams River, Andover, Vermont

    USGS Publications Warehouse

    Striker, Lora K.; Hammond, Robert E.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ANDOVT00110038 on State Route 11 crossing the Middle Branch Williams River, Andover, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province in south central Vermont. The 5.65-mi2 drainage area is in a predominantly rural and forested basin. Upstream and downstream of the study site banks and overbanks are forested. In the study area, the Middle Branch Williams River has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 44 ft and an average bank height of 4 ft. The channel bed material ranges from gravel to boulders with a median grain size (D50) of 54.0 mm (0.177 ft). The geomorphic assessment at the time of the Level I and Level II site visit on September 5, 1996, indicated that the reach was stable. The State Route 11 crossing of the Middle Branch Williams River is a 33-ft-long, two-lane bridge consisting of one 31-foot concrete T-beam span (Vermont Agency of Transportation, written communication, March 29, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 55 degrees to the opening while the measured opening-skew-to-roadway is 45 degrees. There were no scour problems observed during the Level I assessment. Type-4 stone fill (less than 60 inches diameter) and type-3 stone fill

  3. The embryonic myosin R672C mutation that underlies Freeman-Sheldon syndrome impairs cross-bridge detachment and cycling in adult skeletal muscle.

    PubMed

    Racca, Alice W; Beck, Anita E; McMillin, Margaret J; Korte, F Steven; Bamshad, Michael J; Regnier, Michael

    2015-06-15

    Distal arthrogryposis is the most common known heritable cause of congenital contractures (e.g. clubfoot) and results from mutations in genes that encode proteins of the contractile complex of skeletal muscle cells. Mutations are most frequently found in MYH3 and are predicted to impair the function of embryonic myosin. We measured the contractile properties of individual skeletal muscle cells and the activation and relaxation kinetics of isolated myofibrils from two adult individuals with an R672C substitution in embryonic myosin and distal arthrogryposis syndrome 2A (DA2A) or Freeman-Sheldon syndrome. In R672C-containing muscle cells, we observed reduced specific force, a prolonged time to relaxation and incomplete relaxation (elevated residual force). In R672C-containing muscle myofibrils, the initial, slower phase of relaxation had a longer duration and slower rate, and time to complete relaxation was greatly prolonged. These observations can be collectively explained by a small subpopulation of myosin cross-bridges with greatly reduced detachment kinetics, resulting in a slower and less complete deactivation of thin filaments at the end of contractions. These findings have important implications for selecting and testing directed therapeutic options for persons with DA2A and perhaps congenital contractures in general. PMID:25740846

  4. Characterization of the cross-bridge force-generating step using inorganic phosphate and BDM in myofibrils from rabbit skeletal muscles

    PubMed Central

    Tesi, C; Colomo, F; Piroddi, N; Poggesi, C

    2002-01-01

    The inhibitory effects of inorganic phosphate (Pi) on isometric force in striated muscle suggest that in the ATPase reaction Pi release is coupled to force generation. Whether Pi release and the power stroke are synchronous events or force is generated by an isomerization of the quaternary complex of actomyosin and ATPase products (AM.ADP.Pi) prior to the following release of Pi is still controversial. Examination of the dependence of isometric force on [Pi] in rabbit fast (psoas; 5-15 °C) and slow (soleus; 15-20 °C) myofibrils was used to test the two-step hypothesis of force generation and Pi release. Hyperbolic fits of force-[Pi] relations obtained in fast and slow myofibrils at 15 °C produced an apparent asymptote as [Pi]∞ of 0.07 and 0.44 maximal isometric force (i.e. force in the absence of Pi) in psoas and soleus myofibrils, respectively, with an apparent Kd of 4.3 mm in both. In each muscle type, the force-[Pi] relation was independent of temperature. However, 2,3-butanedione 2-monoxime (BDM) decreased the apparent asymptote of force in both muscle types, as expected from its inhibition of the force-generating isomerization. These data lend strong support to models of cross-bridge action in which force is produced by an isomerization of the AM.ADP.Pi complex immediately preceding the Pi release step. PMID:12015429

  5. Properties of highly viscous gels formed by neurofilaments in vitro. A possible consequence of a specific inter-filament cross-bridging.

    PubMed Central

    Leterrier, J F; Eyer, J

    1987-01-01

    Neurofilaments freshly isolated from bovine spinal cord form a reversible gel in vitro, consisting of nearly parallel and interlinked filaments organized in bundles. This phenomenon is obtained above a critical neurofilament concentration and is highly sensitive to denaturation. No gelation occurs with neurofilaments reconstituted from urea-solubilized subunits. The velocity of the gelation kinetics, optimum at a slightly acidic pH, is inhibited by low and high ionic strength and activated by millimolar concentrations of Mg2+ and other bivalent cations. No protein other than the purified neurofilament preparation itself (80-95% neurofilament triplet) is necessary for the formation of a gel. However, purified cytoskeletal proteins from microtubules and neurofilaments influence the viscosity of the native preparation. These observations suggest a reticulation in vitro between neurofilaments, dependent upon a fragile conformation of the polymers and possibly mediated through the high-Mr neurofilament subunits (200 kDa and 150 kDa). The significance of these results is discussed with regard to the inter-neurofilament cross-bridging in situ involving the 200 kDa subunit described by Hirokawa, Glicksman & Willard [(1984) J. Cell Biol. 98, 1523-1536]. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 7. Fig. 8. PMID:3663160

  6. Level II scour analysis for Bridge 6 (RICHTH00030006) on Town Highway 3, crossing an unnamed tributary to the Missisquoi River, Richford, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Song, Donald L.

    1996-01-01

    Contraction scour for all modelled flows ranged from 1.7 to 1.8 ft. The worst-case contraction scour occurred at the 500-year discharge. Scour at the left abutment ranged from 7.6 to 12.6 ft with the worst case occurring at the 100-year event. Scour at the right abutment ranged from 1.6 to 5.6 ft with the worst case occurring at the 500-year event. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  7. Level II scour analysis for Bridge 46 (ENOSVT01080046) on State Route 108, crossing an Unnamed "The Branch" Tributary, Enosburg, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Medalie, Laura

    1996-01-01

    Contraction scour for all modelled flows ranged from 0.3 to 0.5 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.0 to 8.0 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  8. 7. DETAIL VIEW SHOWING CONNECTION OF BRIDGE COLUMN, TRUSS, TOP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. DETAIL VIEW SHOWING CONNECTION OF BRIDGE COLUMN, TRUSS, TOP BEAM, AND ARCHED CROSS MEMBER. NOTE KNEE BRACE FOR CROSS MEMBER AND DIAGONAL TENSION BAR - Heber Creeper Railroad Line, Olmstead Bridge, Spanning Provo River, Provo, Utah County, UT

  9. Cross-modal reorganization in cochlear implant users: Auditory cortex contributes to visual face processing.

    PubMed

    Stropahl, Maren; Plotz, Karsten; Schönfeld, Rüdiger; Lenarz, Thomas; Sandmann, Pascale; Yovel, Galit; De Vos, Maarten; Debener, Stefan

    2015-11-01

    There is converging evidence that the auditory cortex takes over visual functions during a period of auditory deprivation. A residual pattern of cross-modal take-over may prevent the auditory cortex to adapt to restored sensory input as delivered by a cochlear implant (CI) and limit speech intelligibility with a CI. The aim of the present study was to investigate whether visual face processing in CI users activates auditory cortex and whether this has adaptive or maladaptive consequences. High-density electroencephalogram data were recorded from CI users (n=21) and age-matched normal hearing controls (n=21) performing a face versus house discrimination task. Lip reading and face recognition abilities were measured as well as speech intelligibility. Evaluation of event-related potential (ERP) topographies revealed significant group differences over occipito-temporal scalp regions. Distributed source analysis identified significantly higher activation in the right auditory cortex for CI users compared to NH controls, confirming visual take-over. Lip reading skills were significantly enhanced in the CI group and appeared to be particularly better after a longer duration of deafness, while face recognition was not significantly different between groups. However, auditory cortex activation in CI users was positively related to face recognition abilities. Our results confirm a cross-modal reorganization for ecologically valid visual stimuli in CI users. Furthermore, they suggest that residual takeover, which can persist even after adaptation to a CI is not necessarily maladaptive. PMID:26220741

  10. Charged-current inclusive neutrino cross sections in the superscaling model including quasielastic, pion production and meson-exchange contributions

    NASA Astrophysics Data System (ADS)

    Ivanov, M. V.; Megias, G. D.; González-Jiménez, R.; Moreno, O.; Barbaro, M. B.; Caballero, J. A.; Donnelly, T. W.

    2016-08-01

    Charged current inclusive neutrino-nucleus cross sections are evaluated using the superscaling model for quasielastic scattering and its extension to the pion production region. The contribution of two-particle-two-hole vector meson-exchange current excitations is also considered within a fully relativistic model tested against electron scattering data. The results are compared with the inclusive neutrino-nucleus data from the T2K and SciBooNE experiments. For experiments where < {E}ν > ∼ 0.8 {{GeV}}, the three mechanisms considered in this work provide good agreement with the data. However, when the neutrino energy is larger, effects from beyond the Δ also appear to be playing a role. The results show that processes induced by vector two-body currents play a minor role in the inclusive cross sections at the kinematics considered.

  11. Persistent organic pollutants meet adipose tissue hypoxia: does cross-talk contribute to inflammation during obesity?

    PubMed

    Myre, M; Imbeault, P

    2014-01-01

    Lipophilic persistent organic pollutants (POPs) accumulate in lipid-rich tissues such as human adipose tissue. This is particularly problematic in individuals with excess adiposity, a physiological state that may be additionally characterized by local adipose tissue hypoxia. Hypoxic patches occur when oxygen diffusion is insufficient to reach all hypertrophic adipocytes. POPs and hypoxia independently contribute to the development of adipose tissue-specific and systemic inflammation often associated with obesity. Inflammation is induced by increased proinflammatory mediators such as tumour necrosis factor-alpha, interleukin-6, and monocyte chemotactic protein-1, as well as reduced adiponectin release, an anti-inflammatory and insulin-sensitizing adipokine. The aryl hydrocarbon receptor (AhR) mediates the cellular response to some pollutants, while hypoxia responses occur through the oxygen-sensitive transcription factor hypoxia-inducible factor (HIF)-1. There is some overlap between the two signalling pathways since both require a common subunit called the AhR nuclear translocator. As such, it is unclear how adipocytes respond to simultaneous POP and hypoxia exposure. This brief review explores the independent contribution of POPs and adipose tissue hypoxia as factors underlying the inflammatory response from adipocytes during obesity. It also highlights that the combined effect of POPs and hypoxia through the AhR and HIF-1 signalling pathways remains to be tested. PMID:23998203

  12. The contribution of walking to work to adult physical activity levels: a cross sectional study

    PubMed Central

    2014-01-01

    Objective To objectively examine the contribution to adult physical activity levels of walking to work. Methods Employees (n = 103; 36.3 ± 11.7 years) at 17 workplaces in south-west England, who lived within 2 miles (3.2 km) of their workplace, wore Actigraph accelerometers for seven days during waking hours and carried GPS receivers during the commute to and from work. Physical activity volume (accelerometer counts per minute (cpm)) and intensity (minutes of moderate to vigorous physical activity (MVPA)) were computed overall and during the walk to work. Results Total weekday physical activity was 45% higher in participants who walked to work compared to those travelling by car (524.6. ± 170.4 vs 364.6 ± 138.4 cpm) and MVPA almost 60% higher (78.1 ± 24.9 vs 49.8 ± 25.2 minutes per day). No differences were seen in weekend physical activity, and sedentary time did not differ between the groups. Combined accelerometer and GPS data showed that walking to work contributed 47.3% of total weekday MVPA. Conclusions Walking to work was associated with overall higher levels of physical activity in young and middle-aged adults. These data provide preliminary evidence to underpin the need for interventions to increase active commuting, specifically walking, in adults. PMID:24618001

  13. Cross-scale coupling studies with the Heliophysics/Geospace System Observatory: THEMIS/ARTEMIS contributions

    NASA Astrophysics Data System (ADS)

    Angelopoulos, V.; Hietala, H.; Liu, Z.; Mende, S. B.; Phan, T.; Nishimura, T.; Strangeway, R. J.; Burch, J. L.; Moore, T. E.; Giles, B. L.

    2015-12-01

    The recent launch of MMS, the impending launch of ERG, the continued availability of space (NASA, NOAA, International) and ground based assets (THEMIS GBOs, TREx, SuperDARN) enable a comprehensive study of global drivers of (and responses to) kinetic processes at the magnetopause, the magnetotail, the inner magnetosphere and the ionosphere. Previously unresolved questions related to the nature of the modes of magnetospheric convection (pseudobreakups, substorms, SMCs and storms) can now be addressed simultaneously at a kinetic level (with multi-spacecraft missions) and at a global level (with the emerging, powerful H/GSO). THEMIS has been tasked to perform orbital changes that will optimize the observatory, and simultaneously place its probes, along with MMS's, at the heart of where critical kinetic processes occur, near sites of magnetic reconnection and magnetic energy conversion, and in optimal view of ground based assets. I will discuss these unique alignments of the H/GSO fleet that can reveal how cross-scale coupling is manifest, allowing us to view old paradigms in a new light.

  14. Dynamin-Actin Cross Talk Contributes to Phagosome Formation and Closure.

    PubMed

    Marie-Anaïs, Florence; Mazzolini, Julie; Herit, Floriane; Niedergang, Florence

    2016-05-01

    Phagocytosis is a mechanism used by macrophages to internalize and eliminate microorganisms or cellular debris. It relies on profound rearrangements of the actin cytoskeleton that is the driving force allowing plasma membrane extension around the particle. The closure step of phagocytosis, however, remains poorly defined. We used a dedicated experimental setup with Total Internal Reflection Fluorescence Microscopy (TIRFM) to monitor phagosome formation and closure in three dimensions in living cells. We show that dynamin-2, which mediates the scission of endocytic vesicles, was recruited early and concomitantly with actin during phagosome formation. Dynamin-2 accumulated at the site of phagosome closure in living macrophages. Inhibition of its activity with dominant negative mutants or drugs demonstrated that dynamin-2 is implicated in actin dynamics and pseudopod extension. Depolymerization of actin led to impaired dynamin-2 recruitment or activity. Finally, we show that dynamin-2 plays a critical role in the effective scission of the phagosome from the plasma membrane. Thus, we establish that a cross talk between actin and dynamin takes place for phagosome formation and closure before dynamin functions for scission. PMID:26847957

  15. College Graduation Rates for Minority Students in a Selective Technical University: Will Participation in a Summer Bridge Program Contribute to Success?

    ERIC Educational Resources Information Center

    Murphy, Terrence E.; Gaughan, Monica; Hume, Robert; Moore, S. Gordon, Jr.

    2010-01-01

    There are many approaches to solving the problem of underrepresentation of some racial and ethnic groups and women in scientific and technical disciplines. Here, the authors evaluate the association of a summer bridge program with the graduation rate of underrepresented minority (URM) students at a selective technical university. They demonstrate…

  16. Does phosphate release limit the ATPases of soleus myofibrils? Evidence that (A)M. ADP.Pi states predominate on the cross-bridge cycle.

    PubMed

    Iorga, Bogdan; Candau, Robin; Travers, Franck; Barman, Tom; Lionne, Corinne

    2004-01-01

    The ATPases (+/-Ca2+) of myofibrils from rabbit soleus (a slow muscle) and psoas (a fast muscle) have different Ea: -Ca2+, 78 and 60 kJ/mol and +Ca2+, 155 and 71 kJ/mol, respectively. At physiological temperatures, the two types of myofibrillar ATPase are very similar and yet the mechanical properties of the muscles are different (Candau et al. (2003) Biophys J 85: 3132-3141). Muscle contraction relies on specific interactions of the different chemical states on the myosin head ATPase pathway with the thin filament. An explanation for the Ea data is that different states populate the pathways of the two types of myofibril because the rate limiting steps are different. Here, we put this to the test by a comparison of the transient kinetics of the initial steps of the ATPases of the two types of myofibril at 4 degrees C. We used two methods: rapid flow quench ('cold ATP chase': titration of active sites, ATP binding kinetics, k(cat); 'Pi burst': ATP cleavage kinetics) and fluorescence stopped-flow (MDCC-phosphate binding protein for free Pi; myofibrillar tryptophan fluorescence for myosin head-thin filament detachment and ATP cleavage kinetics). We find that, as with psoas myofibrils, the most populated state on the cross-bridge cycle of soleus myofibrils, whether relaxed or activated, is (A)M.ADP.Pi. We propose a reaction pathway that includes several (A)M.ADP.Pi sub-states that are either 'weak' or 'strong', depending on the mechanical condition. PMID:15548866

  17. The biosynthesis of spinosyn in Saccharopolyspora spinosa: synthesis of the cross-bridging precursor and identification of the function of SpnJ.

    PubMed

    Kim, Hak Joong; Pongdee, Rongson; Wu, Qingquan; Hong, Lin; Liu, Hung-wen

    2007-11-28

    Spinosyns are glycosylated polyketide-derived macrolides possessing a perhydro-as-indacene core that is presumably formed via a series of intramolecular cross-bridging reactions. The unusual structure of the spinosyn aglycone suggests an intriguing biosynthetic pathway for its formation, which is expected to be initiated by the oxidation of the 15-OH group of the mature polyketide precursor and may involve a Diels-Alder-type [4 + 2] cycloaddition reaction. Three possible routes, which differ in the order of oxidation and cyclization events, can be envisioned for the biosynthesis of the core structure. Sequence analysis of the spinosyn biosynthetic gene cluster led to the speculation of spnJ as the possible oxidase gene. To explore the early stage of intramolecular ring formation, we cloned and expressed the spnJ gene and purified the SpnJ protein which shows the characteristics of flavoproteins. Two possible substrates for SpnJ, the linear mature polyketide precursor and the corresponding cyclized macrolactone, were also synthesized. TLC and HPLC analysis of the incubation mixture of these compounds with SpnJ revealed that only the synthesized macrolactone could be converted to the corresponding ketone. This result clearly indicated that macrolactone formation proceeds 15-OH oxidation since the linear polyketide is not a substrate for SpnJ. The experiments described herein detail a convergent synthesis of spinosyn macrolactone and validate the catalytic function of SpnJ as a flavin-dependent oxidase. More significantly, we have established the spinosyn macrolactone as the immediate precursor of the tricyclic nucleus of spinosyns. PMID:17985910

  18. Level II scour analysis for Bridge 39 (RANDTH00730039) on Town Highway 73, crossing the Second Branch White River, Randolph, Vermont

    USGS Publications Warehouse

    Song, Donald L.; Ivanoff, Michael A.

    1996-01-01

    Total scour at a highway crossing is comprised of three components: 1) long-term aggradation or degradation; 2) contraction scour (due to reduction in flow area caused by a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute scour depths for contraction and local scour and a summary of the results follows. Contraction scour for all modelled flows ranged from 1.9 ft to 4.6 ft and the worst-case contraction scour occurred at the incipient overtopping discharge. Abutment scour ranged from 4.0 ft to 22.5 ft and the worst-case abutment scour occurred at the 500-year discharge. Scour depths and depths to armoring are summarized on p. 14 in the section titled “Scour Results”. Scour elevations, based on the calculated depths are presented in tables 1 and 2; a graph of the scour elevations is presented in figure 8 Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. For all scour presented in this report, “the scour depths adopted [by VTAOT] may differ from the equation values based on engineering judgement” (Richardson and others, 1993, p. 21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, including historical performance during flood events, the geomorphic assessment, and the results of the hydraulic analyses, must be considered to properly assess the validity of abutment scour results.

  19. College Graduation Rates for Minority Students in a Selective Technical University: Will Participation in a Summer Bridge Program Contribute to Success?

    PubMed Central

    Murphy, Terrence E.; Gaughan, Monica; Hume, Robert; Moore, S. Gordon

    2012-01-01

    There are many approaches to solving the problem of underrepresentation of some racial and ethnic groups and women in scientific and technical disciplines. Here, the authors evaluate the association of a summer bridge program with the graduation rate of underrepresented minority (URM) students at a selective technical university. They demonstrate that this 5-week program prior to the fall of the 1st year contains elements reported as vital for successful student retention. Using multivariable survival analysis, they show that for URM students entering as fall-semester freshmen, relative to their nonparticipating peers, participation in this accelerated summer bridge program is associated with higher likelihood of graduation. The longitudinal panel data include more than 2,200 URM students. PMID:23136456

  20. Aerodynamics of the flying snake Chrysopelea paradisi: how a bluff body cross-sectional shape contributes to gliding performance.

    PubMed

    Holden, Daniel; Socha, John J; Cardwell, Nicholas D; Vlachos, Pavlos P

    2014-02-01

    A prominent feature of gliding flight in snakes of the genus Chrysopelea is the unique cross-sectional shape of the body, which acts as the lifting surface in the absence of wings. When gliding, the flying snake Chrysopelea paradisi morphs its circular cross-section into a triangular shape by splaying its ribs and flattening its body in the dorsoventral axis, forming a geometry with fore-aft symmetry and a thick profile. Here, we aimed to understand the aerodynamic properties of the snake's cross-sectional shape to determine its contribution to gliding at low Reynolds numbers. We used a straight physical model in a water tunnel to isolate the effects of 2D shape, analogously to studying the profile of an airfoil of a more typical flyer. Force measurements and time-resolved (TR) digital particle image velocimetry (DPIV) were used to determine lift and drag coefficients, wake dynamics and vortex-shedding characteristics of the shape across a behaviorally relevant range of Reynolds numbers and angles of attack. The snake's cross-sectional shape produced a maximum lift coefficient of 1.9 and maximum lift-to-drag ratio of 2.7, maintained increases in lift up to 35 deg, and exhibited two distinctly different vortex-shedding modes. Within the measured Reynolds number regime (Re=3000-15,000), this geometry generated significantly larger maximum lift coefficients than many other shapes including bluff bodies, thick airfoils, symmetric airfoils and circular arc airfoils. In addition, the snake's shape exhibited a gentle stall region that maintained relatively high lift production even up to the highest angle of attack tested (60 deg). Overall, the cross-sectional geometry of the flying snake demonstrated robust aerodynamic behavior by maintaining significant lift production and near-maximum lift-to-drag ratios over a wide range of parameters. These aerodynamic characteristics help to explain how the snake can glide at steep angles and over a wide range of angles of attack

  1. On the P-wave contributions to the cross sections of t overlinet and t˜overlinet˜ near threshold

    NASA Astrophysics Data System (ADS)

    Mödritsch, Wolfgang

    1996-02-01

    The approach used for the determination of S-wave amplitudes containing the application of the non-relativistic approximation in the case of P-waves leads to unphysical divergencies. We show how to avoid the latter in calculations of contributions to the cross section near threshold in agreement with field theory. This enables us to give quantitatively reliable predictions for the forward-backward asymmetry and for the axial contribution to the total cross section for the top-antitop system. Also the cross section for the production of stop-antistop near threshold is determined.

  2. The contributions of sensory dominance and attentional bias to cross-modal enhancement of visual cortex excitability.

    PubMed

    Romei, Vincenzo; Murray, Micah M; Cappe, Céline; Thut, Gregor

    2013-07-01

    Approaching or looming sounds (L-sounds) have been shown to selectively increase visual cortex excitability [Romei, V., Murray, M. M., Cappe, C., & Thut, G. Preperceptual and stimulus-selective enhancement of low-level human visual cortex excitability by sounds. Current Biology, 19, 1799-1805, 2009]. These cross-modal effects start at an early, preperceptual stage of sound processing and persist with increasing sound duration. Here, we identified individual factors contributing to cross-modal effects on visual cortex excitability and studied the persistence of effects after sound offset. To this end, we probed the impact of different L-sound velocities on phosphene perception postsound as a function of individual auditory versus visual preference/dominance using single-pulse TMS over the occipital pole. We found that the boosting of phosphene perception by L-sounds continued for several tens of milliseconds after the end of the L-sound and was temporally sensitive to different L-sound profiles (velocities). In addition, we found that this depended on an individual's preferred sensory modality (auditory vs. visual) as determined through a divided attention task (attentional preference), but not on their simple threshold detection level per sensory modality. Whereas individuals with "visual preference" showed enhanced phosphene perception irrespective of L-sound velocity, those with "auditory preference" showed differential peaks in phosphene perception whose delays after sound-offset followed the different L-sound velocity profiles. These novel findings suggest that looming signals modulate visual cortex excitability beyond sound duration possibly to support prompt identification and reaction to potentially dangerous approaching objects. The observed interindividual differences favor the idea that unlike early effects this late L-sound impact on visual cortex excitability is influenced by cross-modal attentional mechanisms rather than low-level sensory processes

  3. Myocardial Bridge

    MedlinePlus

    ... artery. See also on this site: Ask a Texas Heart Institute Doctor: Search "myocardial bridge" Updated August ... comments. Terms of Use and Privacy Policy © Copyright Texas Heart Institute All rights reserved.

  4. Bridging history and social psychology: what, how and why.

    PubMed

    Glăveanu, Vlad; Yamamoto, Koji

    2012-12-01

    This special issue aims to bridge history and social psychology by bringing together historians and social psychologists in an exercise of reading and learning from each other's work. This interdisciplinary exercise is not only timely but of great importance for both disciplines. Social psychologists can benefit from engaging with historical sources by being able to contextualise their findings and enrich their theoretical models. It is not only that all social and psychological phenomena have a history but this history is very much part of present-day and future developments. On the other hand historians can enhance their analysis of historical sources by drawing upon the conceptual tools developed in social psychology. They can "test" these tools and contribute to their validation and enrichment from completely different perspectives. Most important, as contributions to this special issue amply demonstrate, psychology's "historical turn" has the potential to shed a new light on striking, yet underexplored, similarities between contemporary public spheres and their pre-modern counterparts. This issue thereby calls into question the dichotomy between traditional and de-traditionalized societies-a distinction that lies at the heart of many social psychology accounts of the world we live in. The present editorial will introduce and consider this act of bridging history and social psychology by focusing on three main questions: What is the bridge made of? How can the two disciplines be bridged? and Why we cross this interdisciplinary bridge? In the end a reflection on the future of this collaboration will be offered. PMID:22936390

  5. Deletion of 1-43 amino acids in cardiac myosin essential light chain blunts length dependency of Ca(2+) sensitivity and cross-bridge detachment kinetics.

    PubMed

    Michael, John Jeshurun; Gollapudi, Sampath K; Ford, Steven J; Kazmierczak, Katarzyna; Szczesna-Cordary, Danuta; Chandra, Murali

    2013-01-15

    The role of cardiac myosin essential light chain (ELC) in the sarcomere length (SL) dependency of myofilament contractility is unknown. Therefore, mechanical and dynamic contractile properties were measured at SL 1.9 and 2.2 μm in cardiac muscle fibers from two groups of transgenic (Tg) mice: 1) Tg-wild-type (WT) mice that expressed WT human ventricular ELC and 2) Tg-Δ43 mice that expressed a mutant ELC lacking 1-43 amino acids. In agreement with previous studies, Ca(2+)-activated maximal tension decreased significantly in Tg-Δ43 fibers. pCa(50) (-log(10) [Ca(2+)](free) required for half maximal activation) values at SL of 1.9 μm were 5.64 ± 0.02 and 5.70 ± 0.02 in Tg-WT and Tg-Δ43 fibers, respectively. pCa(50) values at SL of 2.2 μm were 5.70 ± 0.01 and 5.71 ± 0.01 in Tg-WT and Tg-Δ43 fibers, respectively. The SL-mediated increase in the pCa(50) value was statistically significant only in Tg-WT fibers (P < 0.01), indicating that the SL dependency of myofilament Ca(2+) sensitivity was blunted in Tg-Δ43 fibers. The SL dependency of cross-bridge (XB) detachment kinetics was also blunted in Tg-Δ43 fibers because the decrease in XB detachment kinetics was significant (P < 0.001) only at SL 1.9 μm. Thus the increased XB dwell time at the short SL augments Ca(2+) sensitivity at short SL and thus blunts SL-mediated increase in myofilament Ca(2+) sensitivity. Our data suggest that the NH(2)-terminal extension of cardiac ELC not only augments the amplitude of force generation, but it also may play a role in mediating the SL dependency of XB detachment kinetics and myofilament Ca(2+) sensitivity. PMID:23144314

  6. Vulnerability of Drinking-Water Wells in La Crosse, Wisconsin, to Enteric-Virus Contamination from Surface Water Contributions

    PubMed Central

    Borchardt, Mark A.; Haas, Nathaniel L.; Hunt, Randall J.

    2004-01-01

    Human enteric viruses can contaminate municipal drinking-water wells, but few studies have examined the routes by which viruses enter these wells. In the present study, the objective was to monitor the municipal wells of La Crosse, Wisconsin, for enteric viruses and determine whether the amount of Mississippi River water infiltrating the wells was related to the frequency of virus detection. From March 2001 to February 2002, one river water site and four wells predicted by hydrogeological modeling to have variable degrees of surface water contributions were sampled monthly for enteric viruses, microbial indicators of sanitary quality, and oxygen and hydrogen isotopes. 18O/16O and 2H/1H ratios were used to determine the level of surface water contributions. All samples were collected prior to chlorination at the wellhead. By reverse transcription-PCR (RT-PCR), 24 of 48 municipal well water samples (50%) were positive for enteric viruses, including enteroviruses, rotavirus, hepatitis A virus (HAV), and noroviruses. Of 12 river water samples, 10 (83%) were virus positive by RT-PCR. Viable enteroviruses were not detected by cell culture in the well samples, although three well samples were positive for culturable HAV. Enteroviruses detected in the wells by RT-PCR were identified as several serotypes of echoviruses and group A and group B coxsackieviruses. None of the well water samples was positive for indicators of sanitary quality, namely male-specific and somatic coliphages, total coliform bacteria, Escherichia coli, and fecal enterococci. Contrary to expectations, viruses were found in all wells regardless of the level of surface water contributions. This result suggests that there were other unidentified sources, in addition to surface water, responsible for the contamination. PMID:15466536

  7. A cross talk between class A scavenger receptor and receptor for advanced glycation end-products contributes to diabetic retinopathy.

    PubMed

    Ma, Ke; Xu, Yiming; Wang, Chenchen; Li, Nan; Li, Kexue; Zhang, Yan; Li, Xiaoyu; Yang, Qing; Zhang, Hanwen; Zhu, Xudong; Bai, Hui; Ben, Jingjing; Ding, Qingqing; Li, Keran; Jiang, Qin; Xu, Yong; Chen, Qi

    2014-12-15

    In response to hyperglycemia in patients with diabetes, many signaling pathways contribute to the pathogenesis of diabetic complications, including diabetic retinopathy (DR). Excessive production of inflammatory mediators plays an important role in this process. Amadori-glycated albumin, one of the major forms of advanced glycated end-products, has been implicated in DR by inducing inflammatory responses in microglia/macrophages. Our goal was to delineate the potential cross talk between class A scavenger receptor (SR-A) and the receptor for advanced glycated end-product (RAGE) in the context of DR. We show here that SR-A ablation caused an exacerbated form of DR in streptozotocin-injected C57BL/6J mice as evidenced by fundus imaging and electroretinography. Immunohistochemical staining and RT-PCR assay indicated that there was augmented activation of proinflammatory macrophages with upregulated synthesis of proinflammatory mediators in the retina in Sr-a(-/-) mice. Overexpression of SR-A suppressed RAGE-induced mitogen-activated protein kinase (MAPK) signaling, whereas RAGE activation in macrophages favored a proinflammatory (M1) phenotype in the absence of SR-A. Mechanistic analysis on bone marrow-derived macrophages and HEK293 cell line revealed that SR-A interacted with and inhibited the phosphorylation of mitogen-activated protein kinase kinase 7, the major kinase in the RAGE-MAPK-NF-κB signaling, thereby leading to diminished secretion of proinflammatory cytokines. Our findings suggest that the antagonism between SR-A and RAGE contributes to the pathogenesis of DR by nurturing a disease-prone macrophage phenotype. Therefore, specific agonist that boosts SR-A signaling could potentially provide benefits in the prevention and/or intervention of DR. PMID:25352436

  8. 5. VIEW OF MCCAMMON BRIDGE FROM U.S. 30, SHOWING RELATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF MCCAMMON BRIDGE FROM U.S. 30, SHOWING RELATION OF PORTNEUF RIVER TO BRIDGE, FACING SOUTHWEST - McCammon Overhead & River Crossing Bridge, Interstate 15, Business, 3.3 mile post , McCammon, Bannock County, ID

  9. Scour assessment at bridges from Flag Point to Million Dollar Bridge, Copper River Highway, Alaska

    USGS Publications Warehouse

    Brabets, T.P.

    1994-01-01

    Twelve bridges are located along the Copper River Highway from Flag Point (Mile 27) to lhe Million Dollar Bridge (Mile 48). These bridges cross all or parts of the Copper River. Channel scour at these bridges was assessed by collecting and analyzing discharge and sediment data, analyzing aerial photography for eight different years, surveying and comparing cross sections, and utilizing scour equations. Between 1968 and 1992, scour occurring at Bridge 331 has formed two distinct channels at the bridge. The channel at Bridge 1187 has remained relatively unchanged between 1968 and 1992. During this same time period, the channel at Bridge 332 appears to have gradually filled. However, during the 1992 runoff season, the channel at this bridge scoured significantly, probably because of its unstable nature. The most significant scour has occurred at Bridge 342. A high-water period in 1981 probably shifted much of the flow of the Copper River through this bridge. As a result, severe contraction scour occurred which required major repairs to the bridge. During 1991 and 1992, the approach channel to Bridge 342 has been migrating, causing scour in the left side of the channel. Bed material at the Million Dollar Bridge consists of hard unweathered boulders nested in dense gravel. Because of this type of erosion-resistant material, no significant scour has occurred at this site. Contraction scour equations overestimated the mean depth of flow at Bridge 331 by 2.6 to 5.0 ft, but were within 1.0 ft of the mean depth of flow for Bridge 1187. The local scour equations generally overestimated local scour at both Bridge 331 and Bridge 1187. The accuracy of some equations was probably affected because water velocities could not be obtained upstream from the piers.

  10. 2. AERIAL VIEW, SHOWING GLENDALE ROAD BRIDGE WITHIN ITS SETTING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. AERIAL VIEW, SHOWING GLENDALE ROAD BRIDGE WITHIN ITS SETTING AT GLENDALE ROAD CROSSING OF DEEP CREEK LAKE (PHOTOGRAPH BY RUTHVAN MORROW) - Glendale Road Bridge, Spanning Deep Creek Lake on Glendale Road, McHenry, Garrett County, MD

  11. 1. AERIAL VIEW, SHOWING GLENDALE ROAD BRIDGE WITHIN ITS SETTING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. AERIAL VIEW, SHOWING GLENDALE ROAD BRIDGE WITHIN ITS SETTING AT GLENDALE ROAD CROSSING OF DEEP CREEK LAKE (PHOTOGRAPH BY RUTHVAN MORROW) - Glendale Road Bridge, Spanning Deep Creek Lake on Glendale Road, McHenry, Garrett County, MD

  12. 7. LOOKING NORTHWEST TOWARD NORTHWEST END OF BRIDGE FROM UNDERNEATH, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. LOOKING NORTHWEST TOWARD NORTHWEST END OF BRIDGE FROM UNDERNEATH, SHOWING CONCRETE SUPPORTS FOR CANTILEVERED WALKWAY (ON RIGHT) - Lincoln Avenue Viaduct, Spanning Union Pacific Railroad between Baring Cross Bridge & Union Station, Little Rock, Pulaski County, AR

  13. 24. Detail view north under bridge showing arched bascule girder, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. Detail view north under bridge showing arched bascule girder, deck girders and cross beams, and bracing of east bascule leaf. - Yellow Mill Bridge, Spanning Yellow Mill Channel at Stratford Avenue, Bridgeport, Fairfield County, CT

  14. 5. GENERAL VIEW OF SOUTHERN PACIFIC RAILROAD BRIDGE, EAST APPROACH, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. GENERAL VIEW OF SOUTHERN PACIFIC RAILROAD BRIDGE, EAST APPROACH, ABUTMENT AND FIRST SET OF PIERS CROSSING RAILROAD LINE, LOOKING NORTH. - Southern Pacific Railroad Bridge, Spanning Rio Grande at Southern Pacific Railroad, El Paso, El Paso County, TX

  15. 4. SHOWING BRIDGE AT UPPER LEFT, UPPER FALLS AND TOP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. SHOWING BRIDGE AT UPPER LEFT, UPPER FALLS AND TOP OF MAIN WATERFALL, FACING NORTHEAST - Paradise River First Crossing Bridge, Spanning Paradise River at Narada Falls on Service Road, Longmire, Pierce County, WA

  16. Improved PET Imaging of uPAR Expression Using new 64Cu-labeled Cross-Bridged Peptide Ligands: Comparative in vitro and in vivo Studies

    PubMed Central

    Persson, Morten; Hosseini, Masood; Madsen, Jacob; Jørgensen, Thomas J. D.; Jensen, Knud J; Kjaer, Andreas; Ploug, Michael

    2013-01-01

    The correlation between uPAR expression, cancer cell invasion and metastases is now well-established and has prompted the development of a number of uPAR PET imaging agents, which could potentially identify cancer patients with invasive and metastatic lesions. In the present study, we synthesized and characterized two new cross-bridged 64Cu-labeled peptide conjugates for PET imaging of uPAR and performed a head-to-head comparison with the corresponding and more conventionally used DOTA conjugate. Based on in-source laser-induced reduction of chelated Cu(II) to Cu(I), we now demonstrate the following ranking with respect to the chemical inertness of their complexed Cu ions: DOTA-AE105 << CB-TE2A-AE105 < CB-TE2A-PA-AE105, which is correlated to their corresponding demetallation rate. No penalty in the uPAR receptor binding affinity of the targeting peptide was encountered by conjugation to either of the macrobicyclic chelators (IC50 ~ 5-10 nM) and high yields and radiochemical purities (>95%) were achieved in all cases by incubation at 95ºC. In vivo, they display identical tumor uptake after 1h, but differ significantly after 22 hrs, where the DOTA-AE105 uptake remains surprisingly high. Importantly, the more stable of the new uPAR PET tracers, 64Cu-CB-TE2A-PA-AE105, exhibits a significantly reduced liver uptake compared to 64Cu-DOTA-AE105 as well as 64Cu-CB-TE2A-AE105, (p<0.0001), emphasizing that our new in vitro stability measurements by mass spectrometry predicts in vivo stability in mice. Specificity of the best performing ligand, 64Cu-CB-TE2A-PA-AE105 was finally confirmed in vivo using a non-binding 64Cu-labeled peptide as control (64Cu-CB-TE2A-PA-AE105mut). This control PET-tracer revealed significantly reduced tumor uptake (p<0.0001), but identical hepatic uptake compared to its active counterpart (64Cu-CB-TE2A-PA-AE105) after 1h. In conclusion, our new approach using in-source laser-induced reduction of Cu(II)-chelated PET-ligands provides useful

  17. Software Bridge

    NASA Technical Reports Server (NTRS)

    1995-01-01

    I-Bridge is a commercial version of software developed by I-Kinetics under a NASA Small Business Innovation Research (SBIR) contract. The software allows users of Windows applications to gain quick, easy access to databases, programs and files on UNIX services. Information goes directly onto spreadsheets and other applications; users need not manually locate, transfer and convert data.

  18. Bridged graphite oxide materials

    NASA Technical Reports Server (NTRS)

    Herrera-Alonso, Margarita (Inventor); McAllister, Michael J. (Inventor); Aksay, Ilhan A. (Inventor); Prud'homme, Robert K. (Inventor)

    2010-01-01

    Bridged graphite oxide material comprising graphite sheets bridged by at least one diamine bridging group. The bridged graphite oxide material may be incorporated in polymer composites or used in adsorption media.

  19. Removal of failed crown and bridge

    PubMed Central

    Rahul, G R.; Poduval, Soorya T.; Shetty, Karunakar

    2012-01-01

    Crown and bridge have life span of many years but they fail for a number of reasons. Over the years, many devices have been designed to remove crowns and bridges from abutment teeth. While the removal of temporary crowns and bridges is usually very straightforward, the removal of a definitive cast crown with unknown cement is more challenging. Removal is often by destructive means. There are a number of circumstances, however, in which conservative disassembly would aid the practitioner in completing restorative/endodontic procedures. There are different mechanisms available to remove a failed crown or bridge. But there is no information published about the classification of available systems for crown and bridge removal. So it is logical to classify these systems into different groups which can help a clinician in choosing a particular type of system depending upon the clinical situation. The aim of this article is to provide a classification for various crown and bridge removal systems; describe how a number of systems work; and when and why they might be used. A PubMed search of English literature was conducted up to January 2010 using the terms: Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. Additionally, the bibliographies of 3 previous reviews, their cross references as well as articles published in various journals like International Endodontic Journal, Journal of Endodontics and were manually searched. Key words:Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. PMID:24558549

  20. Bridge Inspector's Training Manual.

    ERIC Educational Resources Information Center

    Federal Highway Administration (DOT), Washington, DC. Bureau of Public Roads.

    A guide for the instruction of bridge inspectors is provided in this manual as well as instructions for conducting and reporting on a bridge inspection. The chapters outline the qualifications necessary to become a bridge inspector. The subject areas covered are: The Bridge Inspector, Bridge Structures, Bridge Inspection Reporting System,…

  1. The Belizean Bridge Activity.

    ERIC Educational Resources Information Center

    Murfin, Brian

    2000-01-01

    Describes the famous swing bridge in Belize. Students build bridges from a variety of materials and answer the questions, What are different types of bridges?, How do bridges work?, How can you tell if a bridge design will be safe?, and What is the best way to build a bridge over a river while still allowing boat traffic? (SAH)

  2. Contributions of Racial and Sociobehavioral Homophily to Friendship Stability and Quality among Same-Race and Cross-Race Friends

    ERIC Educational Resources Information Center

    McDonald, Kristina L.; Dashiell-Aje, Ebony; Menzer, Melissa M.; Rubin, Kenneth H.; Oh, Wonjung; Bowker, Julie C.

    2013-01-01

    The current study examined how racial and sociobehavioral similarities were associated with friendship stability and friendship quality. Cross-race friends were not significantly similar to each other in peer-nominated shyness/withdrawal, victimization, exclusion, and popularity/sociability. Relative to same-race friends, cross-race friends were…

  3. Level II scour analysis for Bridge 32 (NFIEVT012A0032) on State Route 12A, crossing the Dog River, Northfield, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Ivanoff, Michael A.

    1997-01-01

    section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  4. Level II scour analysis for Bridge 108 (STJOUS00020108) on U.S. Highway 2, crossing the Moose River, St. Johnsbury, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.

    1997-01-01

    section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  5. Mono- and binuclear cyclometallated palladium(II) complexes containing bridging (N,O-) and terminal (N-) imidate ligands: air stable, thermally robust and recyclable catalysts for cross-coupling processes.

    PubMed

    Fairlamb, Ian J S; Kapdi, Anant R; Lee, Adam F; Sánchez, Gregorio; López, Gregorio; Serrano, José Luis; García, Luis; Pérez, José; Pérez, Eduardo

    2004-12-01

    Novel dinuclear cyclometallated palladium complexes [{Pd(mu-NCO)(C circumflex accent N)}(2)], containing asymmetric imidato -NCO- bridging units have been synthesised [C circumflex accent N = 7,8-benzoquinolyl; -NCO- = succinimidate (1c), phthalimidate (1a-3a) or maleimidate (3c)]. The reaction of these complexes, and the previously reported analogous imidate precursors containing a phenylazophenyl (1a-3a) or 2-pyridylphenyl (1b-3b) backbone, with tertiary phosphines provides novel mononuclear N-bonded imidate derivatives of the general formula [Pd(C circumflex accent N)(imidate)(L)][L = PPh(3), P(4-F-C(6)H(4))(3) or P(4-MeO-C(6)H(4))(3)]. The single crystal structures of [Pd(azb)(phthalimidate)(P(4-MeO-C(6)H(4))(3))](9a) and [Pd(bzq)(phthalimidate)(PPh(3))](7c) have been established. Dinuclear complexes (1a-3a, 1b-3b, 1c-3c) demonstrate outstanding thermal stability in the solid-state, as shown by thermoanalytical techniques. A marked influence of bridging imidate groups on the initial decomposition temperature is observed. The dinuclear and mononuclear derivatives are shown to be active catalysts/precatalysts for the Suzuki-Miyaura cross-coupling reactions of aryl bromides with aryl boronic acids, and the Sonogashira reactions of aryl halides with phenyl acetylene (in the presence and absence of Cu(I) salts). The conversions appear to be dependent, to some extent, on the type of imidate ligand, suggesting a role for these pseudohalides in the catalytic cycle in both cross-coupling processes. Lower catalyst loadings in 'copper-free' Sonogashira cross-couplings favour higher turnover frequencies. We have further determined that these catalysts may be recycled using a poly(ethylene oxide)(PEO)/methanol solvent medium in Suzuki-Miyaura cross-coupling. Once the reaction is complete, product extraction into a hexane/diethyl ether mixture (1 : 1, v/v) gives cross-coupled products in good yields (with purity > 95%). The polar phase can then be re-used several times

  6. 6. VIEW OF THE EASTERN BRIDGE ELEVATION, SHOWING CENTRAL PIER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF THE EASTERN BRIDGE ELEVATION, SHOWING CENTRAL PIER AND ASSOCIATED SUPERSTRUCTURE, AND CANTILEVERED NORTHERN TRUSS SECTION. NOTE THE JOIN BETWEEN EYE-BAR (LEFT) AND RIVETED CHANNEL (RIGHT) LOWER BRIDGE CHORDS AT CENTER LEFT OF PHOTOGRAPH. FACING NORTH. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

  7. 7. OBLIQUE VIEW OF WEST BRIDGE ELEVATION, SHOWING NORTHERN ABUTMENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. OBLIQUE VIEW OF WEST BRIDGE ELEVATION, SHOWING NORTHERN ABUTMENT (LEFT), CANTILEVERED NORTHERN TRUSS SECTION (CENTER), AND PIER (RIGHT), FROM SOUTHWEST SIDE OF BRIDGE. FACING NORTHEAST. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

  8. 1. GENERAL VIEW OF BRIDGE, LOOKING NORTH; AT THE TOP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. GENERAL VIEW OF BRIDGE, LOOKING NORTH; AT THE TOP OF THE PHOTOGRAPH ARE THE STEEL STRINGERS OF THE I-55 BRIDGE CROSSING THE SOUTH FORK OF THE SOUTH BRANCH OF THE CHICAGO RIVER - Chicago & Alton Railroad Bridge, Spanning South Branch of Chicago River, Chicago, Cook County, IL

  9. 4. ENVIRONMENT, FROM NORTH, SHOWING RIVER ROAD BRIDGE CARRYING CASSELMAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. ENVIRONMENT, FROM NORTH, SHOWING RIVER ROAD BRIDGE CARRYING CASSELMAN RIVER ROAD OVER CASSELMAN RIVER, WITH MARYLAND GEOLOGICAL SURVEY STREAM-GAUGING STATION AT NORTHEAST CORNER OF BRIDGE - River Road Bridge, Crossing Casselman River on Casselman River Road, Grantsville, Garrett County, MD

  10. Elevation, looking SE. Concrete and steel bridge with exposed steel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevation, looking SE. Concrete and steel bridge with exposed steel frame is the central of three bridges crossing Brush Street between east Baltimore and Piquette. The bridge links Old Lake Shore and Michigan Central Main Line on the western side to a New York Central siding on the eastern side - Railroad Overpass, East Milwaukee & Hastings Avenues, Detroit, MI

  11. The long and short of it: the influence of N-carboxyethyl versus N-carboxymethyl pendant arms on in vitro and in vivo behavior of copper complexes of cross-bridged tetraamine macrocycles

    PubMed Central

    Heroux, Katie J.; Woodin, Katrina S.; Tranchemontagne, David J.; Widger, Peter C. B.; Southwick, Evan; Wong, Edward H.; Weisman, Gary R.; Tomellini, Sterling A.; Wadas, Thaddeus J.; Anderson, Carolyn J.; Kassel, Scott; Golen, James A.; Rheingold, Arnold L.

    2015-01-01

    A cross-bridged cyclam ligand bearing two N-carboxymethyl pendant arms (1) has been found to form a copper(II) complex that exhibits significantly improved biological behavior in recent research towards 64Cu-based radiopharmaceuticals. Both the kinetic inertness and resistance to reduction of Cu–1 are believed to be relevant to its enhanced performance. To explore the influence of pendant arm length on these properties, new cross-bridged cyclam and cyclen ligands with longer N-carboxyethyl pendant arms, 2 and 4, and their respective copper(II) complexes have been synthesized. Both mono- as well as di-O-protonated forms of Cu–2 have also been isolated and structurally characterized. The spectral and structural properties of Cu–2 and Cu–4, their kinetic inertness in 5 M HCl, and electrochemical behavior have been obtained and compared to those of their N-carboxymethyl-armed homologs, Cu–1 and Cu–3. Only the cyclam-based Cu–1 and Cu–2 showed unusually high kinetic inertness towards acid decomplexation. While both of these complexes also exhibited quasi-reversible Cu(II)/Cu(I) reductions, Cu–2 is easier to reduce by a substantial margin of +400 mV, bringing it within the realm of physiological reductants. Similarly, of the cyclen-based complexes, Cu–4 is also easier to reduce than Cu–3 though both reductions are irreversible. Biodistribution studies of 64Cu-labeled 2 and 4 were performed in Sprague Dawley rats. Despite comparable acid inertness to their shorter-armed congeners, both longer-armed ligand complexes have poorer bio-clearance properties. This inferior in vivo behavior may be a consequence of their higher reduction potentials. PMID:17514336

  12. Nondestructive evaluation techniques for enhanced bridge inspection

    SciTech Connect

    Thomas, G.; Benson, S.; Durbin, P.; Del Grande, N.; Haskins, J.; Brown, A.; Schneberk, D.

    1993-10-01

    Nondestructive evaluation of bridges is a critical aspect in the US aging infrastructure problem. For example in California there are 26,000 bridges, 3000 are made of steel, and of the steel bridges, 1000 are fracture critical. California Department of Transportation (Caltrans), Federal Highway Administration, and Lawrence Livermore National Laboratory (LLNL) are collaborating to develop and field NDE techniques to improve bridge inspections. We have demonstrated our NDE technologies on several bridge inspection applications. An early collaboration was to ultrasonically evaluate the steel pins in the E-9 pier on the San Francisco Bay Bridge. Following the Loma-Prieta earthquake in 1989 and the road way collapse at the E-9 pier, a complete nondestructive evaluation was conducted by Caltrans inspectors and several ultrasonic indications were noted. LLNL worked with Caltrans to help identify the source of these reflections. Another project was to digitally enhance high energy radiographs of bridge components such as cable end caps. We demonstrated our ability to improve the detection of corrosion and fiber breakage inside the end cap. An extension of this technology is limited view computer tomography (CT). We implemented our limited view CT software and produced cross-sectional views of bridge cables from digitized radiographic films. Most recently, we are developing dual band infrared imaging techniques to assess bridge decks for delaminations. We have demonstrated the potential of our NDE technology for enhancing the inspection of the country`s aging bridges.

  13. Rugby versus Soccer in South Africa: Content Familiarity Contributes to Cross-Cultural Differences in Cognitive Test Scores

    ERIC Educational Resources Information Center

    Malda, Maike; van de Vijver, Fons J. R.; Temane, Q. Michael

    2010-01-01

    In this study, cross-cultural differences in cognitive test scores are hypothesized to depend on a test's cultural complexity (Cultural Complexity Hypothesis: CCH), here conceptualized as its content familiarity, rather than on its cognitive complexity (Spearman's Hypothesis: SH). The content familiarity of tests assessing short-term memory,…

  14. Evaluating Experiential Learning in the Business Context: Contributions to Group-Based and Cross-Functional Working

    ERIC Educational Resources Information Center

    Piercy, Niall

    2013-01-01

    The use of experiential learning techniques has become popular in business education. Experiential learning approaches offer major benefits for teaching contemporary management practices such as cross-functional and team-based working. However, there remains relatively little empirical data on the success of experiential pedagogies in supporting…

  15. Salt-Bridge Energetics in Halophilic Proteins

    PubMed Central

    Nayek, Arnab; Sen Gupta, Parth Sarthi; Banerjee, Shyamashree; Mondal, Buddhadev; Bandyopadhyay, Amal K.

    2014-01-01

    Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges) to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are −3.0 kcal mol−1. Majority (78%) of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46%) with a net contribution of −5.0 kcal mol−1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (−10 kcal mol−1) exceeds than that of bridge term (−7 kcal mol−1). Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic

  16. Bridge diagnosis at 55 mph

    SciTech Connect

    Azevedo, S

    1998-10-01

    The Federal Highway Administration (FHWA) has helped sponsor a research project at Lawrence Livermore that produced a beneficial new tool as well as an R&D 100 Award. The HERMES Bridge Inspector will provide an invaluable capability to diagnose the problems of deteriorating bridge decks and do it accurately, efficiently, nondestructively, and, perhaps most important to motorists, without closing bridges. Almost 30% of 600,000 large highway bridges in the U.S. are classified "deficient" by the FHWA, and HERMES can make a significant contribution toward solving the problem of infrastructure assessment and repair. With further development, HERMES holds promise for other concrete inspection problems, such as railroads, tunnels, and runways. HERMES, or High-performance Electromagnetic Roadway Mapping and Evaluation System, is a radar-based sensing system mounted in a trailer. It can be pulled by a vehicle at traffic speeds over a bridge deck to collect information about the roadway subsurface -- its sensors gathering data 30 centimeters or more into concrete. An onboard computer system processes the data into three-dimensional images that pinpoint problems in the roadway concrete and give engineers quantitative information about deterioration in the bridge deck. Engineers can then better assess what repairs or reconstruction is necessary and avoid the cost overruns and delays that result from inexact problem diagnoses.

  17. Design, fabrication, and characterization of a planar, silicon-based, monolithically integrated micro laminar flow fuel cell with a bridge-shaped microchannel cross-section

    NASA Astrophysics Data System (ADS)

    López-Montesinos, P. O.; Yossakda, N.; Schmidt, A.; Brushett, F. R.; Pelton, W. E.; Kenis, P. J. A.

    2011-05-01

    We report the fabrication of a planar, silicon-based, monolithically integrated micro laminar flow fuel cell (μLFFC) using standard MEMS and IC-compatible fabrication technologies. The μLFFC operates with acid supported solutions of formic acid and potassium permanganate, as a fuel and oxidant respectively. The micro-fuel cell design features two in-plane anodic and cathodic microchannels connected via a bridge to confine the diffusive liquid-liquid interface away from the electrode areas and to minimize crossover. Palladium high-active-surface-area catalyst was selectively integrated into the anodic microchannel by electrodeposition, whereas no catalyst was required in the cathodic microchannel. A three-dimensional (3D) diffusion-convection model was developed to study the behavior of the diffusion zone and to extract appropriate cell-design parameters and operating conditions. Experimentally, we observed peak power densities as high as 26 mW cm-2 when operating single cells at a flow rate of 60 μL min-1 at room temperature. The miniature membraneless fuel cell design presented herein offers potential for on-chip power generation, which has long been prohibited by integration complexities associated with the membrane.

  18. THE TRUSS BRIDGE SEGMENT OF THE TRIBOROUGH BRIDGE IN FOREGROUND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    THE TRUSS BRIDGE SEGMENT OF THE TRIBOROUGH BRIDGE IN FOREGROUND AND THE HELL GATE BRIDGE IN THE BACKGROUND ADJACENT TO THE SUSPENSION SEGMENT OF THE TRIBOROUGH BRIDGE. - Triborough Bridge, Passing through Queens, Manhattan & the Bronx, Queens (subdivision), Queens County, NY

  19. 13. RAILROAD BRIDGE MISSISSIPPI, MONROE CO., ABERDEEN 1.5 mi. NW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. RAILROAD BRIDGE MISSISSIPPI, MONROE CO., ABERDEEN 1.5 mi. NW of Amory. St. Louis and San Francisco RR bridge. Steam locomotive and coal train cross bridge on 10 August 1921. Credit: Owned by Jack Donnell, Columbus, Ms., photographer. Copied by Sarcone Photography, Columbus, Ms. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  20. Empirical parametrization of the two-photon-exchange effect contributions to the electron-proton elastic scattering cross section

    SciTech Connect

    Qattan, I. A.; Alsaad, A.

    2011-05-15

    The most recent electron-proton elastic scattering data were re-analyzed using an empirical parametrization of the two-photon-exchange (TPE) effect contributions to {sigma}{sub R}. The TPE effect contribution F(Q{sup 2},{epsilon}) was double Taylor series expanded as a polynomial of order n keeping only terms linear in {epsilon} to account for the experimentally observed and verified linearity of the Rosenbluth plots. We fix the ratio R=G{sub Ep}/G{sub Mp} to be that obtained from a fit to the recoil-polarization data and parametrize {sigma}{sub R} first by a three-parameter formula (fit I) and then by a two-parameter formula (fit III). In contrast to previous analyses, the fit parameter G{sub Mp}{sup 2} as obtained from these fits is either smaller or equal to the values obtained from our conventional Rosenbluth fit (fit II) but never larger. The ratio g(Q{sup 2})/G{sub Mp}{sup 2} which represents the ratio of the TPE and one-photon-exchange (OPE) effect contributions to the intercept of {sigma}{sub R} is large and it ranges 3%-88%. The ratio R{sub 1{gamma}x2{gamma}={tau}}f(Q{sup 2})/G{sub Ep}{sup 2} which represents the ratio of the TPE and OPE effect contributions to the slope of {sigma}{sub R} is also large, reaching a value of 12.0-14.4 at Q{sup 2}= 5.25 (GeV/c){sup 2}. The ratio R{sub 1{gamma}x2{gamma}} as obtained from fits I and III is consistent, within error, with those obtained from previous analyses. Our formulas seem to explain the linearity of {sigma}{sub R}. Moreover, our analysis shows that the extracted G{sub Ep}{sup 2} and G{sub Mp}{sup 2} using the conventional Rosenbluth separation method can in fact be broken into the usual OPE and TPE contributions. Therefore, {sigma}{sub R} can in fact be derived under weaker conditions than those imposed by the Born approximation. Our results show that the TPE amplitudes, g(Q{sup 2})/G{sub Mp}{sup 2} and f(Q{sup 2})/G{sub Mp}{sup 2}, are sizable and grow with Q{sup 2} value up to Q{sup 2}{approx}6 (Ge

  1. Non-coplanar compact configurations of nuclei and non-compound-nucleus contribution in the fusion cross section of the 12C+93Nb reaction

    NASA Astrophysics Data System (ADS)

    Chopra, Sahila; Hemdeep, Kaur, Arshdeep; Gupta, Raj K.

    2016-02-01

    Background: In our earlier study of the 12C+93Nb→*105Ag reaction at three near- and below-barrier energies (Ec .m .=41.097 , 47.828, and 54.205 MeV), using the dynamical cluster-decay model (DCM) with various nuclear interaction potentials (the Blocki et al. pocket formula and others derived from the Skyrme energy density formalism) for compact, coplanar (Φc=00 ) nuclei, we found a large non-compound-nucleus (nCN) contribution in the measured fusion cross section of this reaction. Purpose: In the present work, we look for the effect of using non-coplanar, compact configurations (Φc≠00 ), in the Blocki et al. pocket formula of the nuclear proximity potential, on the non-compound-nucleus (nCN) contribution, using the DCM. Methods: Allowing the Φ degree of freedom in the DCM formalism, we calculate the compound-nucleus (CN) and nCN cross sections. The only parameter of the DCM is the neck-length parameter Δ R , which also fits the empirically determined nCN cross section nearly exactly, under the assumption of considering it like a quasifission process where the fragment preformation factor P0=1 . Results: With the Φ degree of freedom included, at the higher two energies the nCN cross section gets enhanced, and hence the pure CN cross section is decreased, since the calculated (total) fusion cross section is fitted to experimental data. The parameter Δ R for the nCN contribution is smaller, and hence the reaction time larger, than for the CN decay process. Also, the contributing angular momentum ℓmax value increases in going from Φc=00 to Φc≠00 for both the CN and nCN processes. The intermediate mass fragments (IMFs), measured up to mass 13 in this reaction, are shown extended up to mass 16, and the fusion-fission (f f ) region is identified as A /2 ±16 , the same as for the Φc=00 case. Conclusions: As a result of enhanced nCN cross section due to Φc≠00 , the CN fusion probability PCN for *105Ag changes its behavior from an increasing to a

  2. Inflammation, Oxidative Stress, and Antioxidants Contribute to Selected Sleep Quality and Cardiometabolic Health Relationships: A Cross-Sectional Study

    PubMed Central

    Kanagasabai, Thirumagal; Ardern, Chris I.

    2015-01-01

    Sleep is vital for cardiometabolic health, but a societal shift toward poor sleep is a prominent feature of many modern cultures. Concurrently, factors such as diet and lifestyle have also changed and may mediate the relationship between sleep quality and cardiometabolic health. Objectives were to explore (1) the interrelationship and (2) mediating effect of inflammation, oxidative stress, and antioxidants on sleep quality and cardiometabolic health. Cross-sectional data from the US National Health and Nutritional Examination Survey 2005-06 (≥20 y; N = 2,072) was used. Cardiometabolic health was defined as per the Joint Interim Statement; overall sleep quality was determined from six sleep habits and categorized as good, fair, poor, and very poor. Fair quality sleepers had optimal inflammation, oxidative stress, and antioxidant levels. Inflammation was above the current clinical reference range across all sleep quality categories, while oxidative stress was only within the clinical reference range for fair sleep quality. Selected sleep quality-cardiometabolic health relationships were mediated by inflammation, oxidative stress, and antioxidants and were moderated by sex. Our results provide initial evidence of a potential role for inflammation, oxidative stress, and antioxidants in the pathway between poor sleep quality-cardiometabolic decline. Further prospective research is needed to confirm our results. PMID:26568665

  3. Oxidation-mediated DNA cross-linking contributes to the toxicity of 6-thioguanine in human cells.

    PubMed

    Brem, Reto; Karran, Peter

    2012-09-15

    The thiopurines azathioprine and 6-mercaptopurine have been extensively prescribed as immunosuppressant and anticancer agents for several decades. A third member of the thiopurine family, 6-thioguanine (6-TG), has been used less widely. Although known to be partly dependent on DNA mismatch repair (MMR), the cytotoxicity of 6-TG remains incompletely understood. Here, we describe a novel MMR-independent pathway of 6-TG toxicity. Cell killing depended on two properties of 6-TG: its incorporation into DNA and its ability to act as a source of reactive oxygen species (ROS). ROS targeted DNA 6-TG to generate potentially lethal replication-arresting DNA lesions including interstrand cross-links. These triggered processing by the Fanconi anemia and homologous recombination DNA repair pathways. Allopurinol protected against 6-TG toxicity by acting as a ROS scavenger and preventing DNA damage. Together, our findings provide mechanistic evidence to support the proposed use of thiopurines to treat HR-defective tumors and for the coadministration of 6-TG and allopurinol as an immunomodulation strategy in inflammatory disorders. PMID:22822082

  4. The Hydrophobic Effect Contributes to the Closed State of a Simplified Ion Channel through a Conserved Hydrophobic Patch at the Pore-Helix Crossing

    PubMed Central

    Yonkunas, Michael; Kurnikova, Maria

    2015-01-01

    Ion selectivity-filter structures are strikingly similar throughout the large family of K++ channels and other p-loop-like receptors (i.e., glutamate receptors). At the same time, the triggers for opening these channels, or gating, are diverse. Two questions that remain unanswered regarding these channels are: (1) what force(s) stabilize the closed non-conducting channel-pore conformation? And (2) what is the free energy associated with transitioning from a closed (non-conducting) to an open (conducting) channel-pore conformation? The effects of charge and hydrophobicity on the conformational states of a model tetrameric biological ion channel are shown utilizing the amino acid sequence from the K+ channel KcsA as the model “channel”. Its widely conserved hydrophobic bundle crossing located adjacent to the lipid head-groups at the intracellular side of the membrane was calculated to have a 5 kcal/mol free energy difference between modeled open and closed conformations. Simulated mutants of amino acids within the hydrophobic region significantly contribute to the size of this difference. Specifically for KcsA, these residues are part of the pH sensor important for channel gating and our results are in agreement with published electrophysiology data. Our simulations support the idea that the hydrophobic effect contributes significantly to the stability of the closed conformation in tetrameric ion channels with a hydrophobic bundle crossing positioned in proximity to the lipid head groups of the biological membrane. PMID:26640439

  5. Why do mothers encourage their children to control their weight? A cross-sectional study of possible contributing factors

    PubMed Central

    2014-01-01

    Background Mothers encouraging their children to control their weight is problematic as it is associated with children’s body dissatisfaction and weight concerns as well as further weight gain. The aim of this study was to identify factors in children and mothers associated with mothers encouraging their children to control their weight and possible gender differences therein. Methods Cross-sectional questionnaire data was available from 1658 mothers of primary school children (mean age 7.1 ±0.6 years, 50.4% boys) participating in the Baden-Württemberg Study. Children’s body weight and height were measured in a standardised manner. Logistic regressions were computed separately for boys and girls, adjusted odds ratios (OR) and 95% confidence intervals (CI) from the final model are reported. Results 29% of children were encouraged by their mothers, girls (32.4%) significantly more often than boys (25.6%). Child BMI (girls OR 1.77, CI 1.57 to 1.99; boys OR 1.88, CI 1.66 to 2.13), and child migration background (girls OR 2.14, CI 1.45 to 3.16; boys OR 1.60, CI 1.07 to 2.37) were significantly associated with encouragement by mothers. For girls, maternal body dissatisfaction (OR 1.59, CI 1.10 to 2.30) and maternal perception of a low influence on health (OR 0.51, CI 0.29 to 0.89) were also significantly associated with maternal encouragement. For boys, this was true of mothers self-efficacy to influence their children’s physical activity (OR 0.58, CI 0.40 to 0.85). Conclusion Different factors are associated with mothers encouraging boys and girls to control their weight. Identifying correlates and underlying processes of maternal encouragement can inform preventive measures targeting weight and eating related problems in children. PMID:24885349

  6. 3-D Shear Wave Velocity Model of Mexico and South US: Bridging Seismic Networks with Ambient Noise Cross-Correlations (C1) and Correlation of Coda of Correlations (C3).

    NASA Astrophysics Data System (ADS)

    Spica, Zack; Perton, Mathieu; Calò, Marco; Legrand, Denis; Córdoba Montiel, Francisco; Iglesias, Arturo

    2016-07-01

    This work presents an innovative strategy to enhance the resolution of surface wave tomography obtained from ambient noise cross-correlation (C1) by bridging asynchronous seismic networks through the correlation of coda of correlations (C3). Rayleigh wave group dispersion curves show consistent results between synchronous and asynchronous stations. Rayleigh wave group travel times are inverted to construct velocity-period maps with unprecedented resolution for a region covering Mexico and the southern United States. The resulting period maps are then used to regionalize dispersion curves in order to obtain local 1-D shear velocity models (VS) of the crust and uppermost mantle in every cell of a grid of 0.4°. The 1-D structures are obtained by iteratively adding layers until reaching a given misfit, and a global tomography model is considered as an input for depths below 150 km. Finally, a high-resolution 3-D VS model is obtained from these inversions. The major structures observed in the 3-D model are in agreement with the tectonic-geodynamic features and with previous regional and local studies. It also offers new insights to understand the present and past tectonic evolution of the region.

  7. 64Cu-labeled somatostatin analogues conjugated with cross-bridged phosphonate-based chelators via strain-promoted click chemistry for PET imaging: in silico through in vivo studies.

    PubMed

    Cai, Zhengxin; Ouyang, Qin; Zeng, Dexing; Nguyen, Kim N; Modi, Jalpa; Wang, Lirong; White, Alexander G; Rogers, Buck E; Xie, Xiang-Qun; Anderson, Carolyn J

    2014-07-24

    Somatostatin receptor subtype 2 (sstr2) is a G-protein-coupled receptor (GPCR) that is overexpressed in neuroendocrine tumors. The homology model of sstr2 was built and was used to aid the design of new somatostatin analogues modified with phosphonate-containing cross-bridged chelators for evaluation of using them as PET imaging radiopharmaceuticals. The new generation chelators were conjugated to Tyr3-octreotate (Y3-TATE) through bioorthogonal, strain-promoted alkyne azide cycloaddition (SPAAC) to form CB-TE1A1P-DBCO-Y3-TATE (AP) and CB-TE1K1P-PEG4-DBCO-Y3-TATE (KP) in improved yields compared to standard direct conjugation methods of amide bond formation. Consistent with docking studies, the clicked bioconjugates showed high binding affinities to sstr2, with Kd values ranging from 0.6 to 2.3 nM. Selected isomers of the clicked products were used in biodistribution and PET/CT imaging. Introduction of the bulky dibenzocyclooctyne group in AP decreased clearance rates from circulation. However, the additional carboxylate group and PEG linker from the KP conjugate significantly improved labeling conditions and in vivo stability of the copper complex and ameliorated the slower pharmacokinetics of the clicked somatostatin analogues. PMID:24983404

  8. 3-D shear wave velocity model of Mexico and South US: bridging seismic networks with ambient noise cross-correlations (C1) and correlation of coda of correlations (C3)

    NASA Astrophysics Data System (ADS)

    Spica, Zack; Perton, Mathieu; Calò, Marco; Legrand, Denis; Córdoba-Montiel, Francisco; Iglesias, Arturo

    2016-09-01

    This work presents an innovative strategy to enhance the resolution of surface wave tomography obtained from ambient noise cross-correlation (C1) by bridging asynchronous seismic networks through the correlation of coda of correlations (C3). Rayleigh wave group dispersion curves show consistent results between synchronous and asynchronous stations. Rayleigh wave group traveltimes are inverted to construct velocity-period maps with unprecedented resolution for a region covering Mexico and the southern United States. The resulting period maps are then used to regionalize dispersion curves in order to obtain local 1-D shear velocity models (VS) of the crust and uppermost mantle in every cell of a grid of 0.4°. The 1-D structures are obtained by iteratively adding layers until reaching a given misfit, and a global tomography model is considered as an input for depths below 150 km. Finally, a high-resolution 3-D VS model is obtained from these inversions. The major structures observed in the 3-D model are in agreement with the tectonic-geodynamic features and with previous regional and local studies. It also offers new insights to understand the present and past tectonic evolution of the region.

  9. The Natural Cytotoxicity Receptor 1 Contribution to Early Clearance of Streptococcus pneumoniae and to Natural Killer-Macrophage Cross Talk

    PubMed Central

    Yossef, Rami; Hadad, Uzi; Elkabets, Moshe; Vallon-Eberhard, Alexandra; Hulihel, Luai; Jung, Steffen; Ghadially, Hormas; Braiman, Alex; Apte, Ron N.; Mandelboim, Ofer; Dagan, Ron; Mizrachi-Nebenzahl, Yaffa; Porgador, Angel

    2011-01-01

    Natural killer (NK) cells serve as a crucial first line of defense against tumors, viral and bacterial infections. We studied the involvement of a principal activating natural killer cell receptor, natural cytotoxicity receptor 1 (NCR1), in the innate immune response to S. pneumoniae infection. Our results demonstrate that the presence of the NCR1 receptor is imperative for the early clearance of S. pneumoniae. We tied the ends in vivo by showing that deficiency in NCR1 resulted in reduced lung NK cell activation and lung IFNγ production at the early stages of S. pneumoniae infection. NCR1 did not mediate direct recognition of S. pneumoniae. Therefore, we studied the involvement of lung macrophages and dendritic cells (DC) as the mediators of NK-expressed NCR1 involvement in response to S. pneumoniae. In vitro, wild type BM-derived macrophages and DC expressed ligands to NCR1 and co-incubation of S. pneumoniae-infected macrophages/DC with NCR1-deficient NK cells resulted in significantly lesser IFNγ levels compared to NCR1-expressing NK cells. In vivo, ablation of lung macrophages and DC was detrimental to the early clearance of S. pneumoniae. NCR1-expressing mice had more potent alveolar macrophages as compared to NCR1-deficient mice. This result correlated with the higher fraction of NCR1-ligandhigh lung macrophages, in NCR1-expressing mice, that had better phagocytic activity compared to NCR1-liganddull macrophages. Overall, our results point to the essential contribution of NK-expressed NCR1 in early response to S. pneumoniae infection and to NCR1-mediated interaction of NK and S. pneumoniae infected-macrophages and -DC. PMID:21887255

  10. Can we bridge the gap? Knowledge and practices related to Diabetes Mellitus among general practitioners in a developing country: A cross sectional study

    PubMed Central

    2011-01-01

    Background Diabetes mellitus is becoming a serious public health problem in Sri Lanka and many other developing countries in the region. It is well known that effective management of diabetes reduces the incidence and progression of many diabetes related complications, thus it is important that General Practitioners (GPs) have sound knowledge and positive attitudes towards all aspects of its management. This study aims to assess knowledge, awareness and practices relating to management of Diabetes Mellitus among Sri Lankan GPs. Methods A cross-sectional study was conducted among all 246 GPs registered with the Ceylon College of General Practitioners using a pre-validated self-administered questionnaire. Results 205 responded to the questionnaire(response rate 83.3%). Their mean duration of practice was 28.7 ± 11.2 years. On average, each GP had 27 ± 25 diabetic-patient consultations per-week. 96% managed diabetic patients and 24% invariably sought specialist opinion. 99.2% used blood glucose to diagnose diabetes but correct diagnostic cut-off values were known by only 48.8%. Appropriate use of HbA1c and urine microalbumin was known by 15.2% and 39.2% respectively. 84% used HbA1c to monitor glyceamic control, while 90.4% relied on fasting blood glucose to monitor glyceamic control. Knowledge on target control levels was poor. Nearly 90% correctly selected the oral hypoglyceamic treatment for obese as well as thin type 2 diabetic patients. Knowledge on the management of diabetes in pregnancy was poor. Only 23.2% knew the correct threshold for starting lipid-lowering therapy. The concept of strict glycaemic control in preference to symptom control was appreciated only by 68%. The skills for comprehensive care in subjects with multiple risk factors were unsatisfactory. Conclusions The study was done among experienced members of the only professional college dedicated to the specialty. However, we found that there is room for improvement in their knowledge and

  11. Burning trees and bridges

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.

    1990-01-01

    Most burning of biomass is the result of human activity, and on a global scale it is increasing. Tropospheric concentrations of CO2, CO, CH4, non-methane hydrocarbons, and ozone are all increasing with time; global biomass burning may make an important contribution to this increase and thus to potential global climate change. The nitrogen cycle also can have important climatic effects. Nitrous oxide put into the atmosphere by biomass burning is a greenhouse gas 250 times more powerful (molecule for molecule) than carbon dioxide. Nitric oxide, as well as being a photochemical precursor of ozone, a major pollutant in the troposphere, produces nitric acid, the fastest-growing component of acid rain. Hence, the new bridge in the nitrogen cycle is of more than mere technical interest.

  12. Liquid bridges with thermocapillarity

    NASA Technical Reports Server (NTRS)

    Xu, J.-J.; Davis, S. H.

    1983-01-01

    An axisymmetric liquid bridge is subjected to an axial temperature gradient. Thermal variations in surface tension drive a motion that is described using lubrication theory for slender bridges. At leading order in aspect ratio, a class of similarity solutions is obtained valid in the core region away from the endwalls of the bridge. These solutions describe the flows, temperature fields, and interfacial shapes of bridges that may sustain substantial interfacial deflections.

  13. Planar Hall effect bridge magnetic field sensors

    SciTech Connect

    Henriksen, A. D.; Dalslet, B. T.; Skieller, D. H.; Lee, K. H.; Okkels, F.; Hansen, M. F.

    2010-07-05

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can be significantly enhanced by a geometric factor. For the samples in the present study, we demonstrate an enhancement of the sensor output by a factor of about 100 compared to cross-shaped sensors. The presented construction opens a new design and application area of the planar Hall effect, which we term planar Hall effect bridge sensors.

  14. Building the Clinical Bridge: An Australian Success

    PubMed Central

    Wallis, Marianne; Chaboyer, Wendy

    2012-01-01

    Nursing effectiveness science includes primary, secondary, and translational, clinically focused research activities which aim to improve patient or client outcomes. It is imperative, for the successful conduct of a program of nursing effectiveness science, that a clinical bridge is established between academic and healthcare service facilities. An Australian example of the development of a robust clinical bridge through the use of jointly funded positions at the professorial level is outlined. In addition, an analysis of the practical application of Lewin's model of change management and the contribution of both servant and transformational leadership styles to the bridge building process is provided. PMID:22577536

  15. Building the clinical bridge: an Australian success.

    PubMed

    Wallis, Marianne; Chaboyer, Wendy

    2012-01-01

    Nursing effectiveness science includes primary, secondary, and translational, clinically focused research activities which aim to improve patient or client outcomes. It is imperative, for the successful conduct of a program of nursing effectiveness science, that a clinical bridge is established between academic and healthcare service facilities. An Australian example of the development of a robust clinical bridge through the use of jointly funded positions at the professorial level is outlined. In addition, an analysis of the practical application of Lewin's model of change management and the contribution of both servant and transformational leadership styles to the bridge building process is provided. PMID:22577536

  16. Polymeric salt bridges for conducting electric current in microfluidic devices

    DOEpatents

    Shepodd, Timothy J.; Tichenor, Mark S.; Artau, Alexander

    2009-11-17

    A "cast-in-place" monolithic microporous polymer salt bridge for conducting electrical current in microfluidic devices, and methods for manufacture thereof is disclosed. Polymeric salt bridges are formed in place in capillaries or microchannels. Formulations are prepared with monomer, suitable cross-linkers, solvent, and a thermal or radiation responsive initiator. The formulation is placed in a desired location and then suitable radiation such as UV light is used to polymerize the salt bridge within a desired structural location. Embodiments are provided wherein the polymeric salt bridges have sufficient porosity to allow ionic migration without bulk flow of solvents therethrough. The salt bridges form barriers that seal against fluid pressures in excess of 5000 pounds per square inch. The salt bridges can be formulated for carriage of suitable amperage at a desired voltage, and thus microfluidic devices using such salt bridges can be specifically constructed to meet selected analytical requirements.

  17. Contributions and challenges of cross-national comparative research in migration, ethnicity and health: insights from a preliminary study of maternal health in Germany, Canada and the UK

    PubMed Central

    2011-01-01

    Background Public health researchers are increasingly encouraged to establish international collaborations and to undertake cross-national comparative studies. To-date relatively few such studies have addressed migration, ethnicity and health, but their number is growing. While it is clear that divergent approaches to such comparative research are emerging, public health researchers have not so far given considered attention to the opportunities and challenges presented by such work. This paper contributes to this debate by drawing on the experience of a recent study focused on maternal health in Canada, Germany and the UK. Discussion The paper highlights various ways in which cross-national comparative research can potentially enhance the rigour and utility of research into migration, ethnicity and health, including by: forcing researchers to engage in both ideological and methodological critical reflexivity; raising awareness of the socially and historically embedded nature of concepts, methods and generated 'knowledge'; increasing appreciation of the need to situate analyses of health within the wider socio-political setting; helping researchers (and research users) to see familiar issues from new perspectives and find innovative solutions; encouraging researchers to move beyond fixed 'groups' and 'categories' to look at processes of identification, inclusion and exclusion; promoting a multi-level analysis of local, national and global influences on migrant/minority health; and enabling conceptual and methodological development through the exchange of ideas and experience between diverse research teams. At the same time, the paper alerts researchers to potential downsides, including: significant challenges to developing conceptual frameworks that are meaningful across contexts; a tendency to reify concepts and essentialise migrant/minority 'groups' in an effort to harmonize across countries; a danger that analyses are superficial, being restricted to independent

  18. 5. VIEW OF UPPER AND LOWER CASCADE BRIDGES AND CASCADE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF UPPER AND LOWER CASCADE BRIDGES AND CASCADE CREEK FROM 100 YARDS WEST OF THE ROSTRUM (ROCK FORMATION ON SOUTH SIDE OF MERCED RIVER). HIGHWAY 140 IS AT BOTTOM OF FRAME. HIGHWAY 120, THE BIG OAK FLAT ROAD CROSSES FRAME JUST ABOVE CENTER. - Cascade Creek Bridge, Spanning Cascade Creek on New Big Oak Flat Road, Yosemite Village, Mariposa County, CA

  19. 4. APPROACH TO BRIDGE FROM SOUTH. LOOKING NORTH. Route ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. APPROACH TO BRIDGE FROM SOUTH. LOOKING NORTH. - Route 31 Bridge, New Jersey Route 31, crossing disused main line of Central Railroad of New Jersey (C.R.R.N.J.) (New Jersey Transit's Raritan Valley Line), Hampton, Hunterdon County, NJ

  20. 3. APPROACH TO BRIDGE FROM NORTH. LOOKING SOUTH. Route ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. APPROACH TO BRIDGE FROM NORTH. LOOKING SOUTH. - Route 31 Bridge, New Jersey Route 31, crossing disused main line of Central Railroad of New Jersey (C.R.R.N.J.) (New Jersey Transit's Raritan Valley Line), Hampton, Hunterdon County, NJ

  1. 2. BRIDGE IN CONTEXT, FROM WEST SIDE. LOOKING EAST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. BRIDGE IN CONTEXT, FROM WEST SIDE. LOOKING EAST. - Route 31 Bridge, New Jersey Route 31, crossing disused main line of Central Railroad of New Jersey (C.R.R.N.J.) (New Jersey Transit's Raritan Valley Line), Hampton, Hunterdon County, NJ

  2. 1. BRIDGE IN CONTEXT, FROM EAST SIDE. LOOKING WEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. BRIDGE IN CONTEXT, FROM EAST SIDE. LOOKING WEST. - Route 31 Bridge, New Jersey Route 31, crossing disused main line of Central Railroad of New Jersey (C.R.R.N.J.) (New Jersey Transit's Raritan Valley Line), Hampton, Hunterdon County, NJ

  3. 10. UNDERSIDE, VIEW PARALLEL TO BRIDGE, SHOWING FLOOR SYSTEM AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. UNDERSIDE, VIEW PARALLEL TO BRIDGE, SHOWING FLOOR SYSTEM AND SOUTH PIER. LOOKING SOUTHEAST. - Route 31 Bridge, New Jersey Route 31, crossing disused main line of Central Railroad of New Jersey (C.R.R.N.J.) (New Jersey Transit's Raritan Valley Line), Hampton, Hunterdon County, NJ

  4. 4. WIDEANGLE VIEW OF THE EASTERN BRIDGE ELEVATION, SHOWING CANTILEVERED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. WIDE-ANGLE VIEW OF THE EASTERN BRIDGE ELEVATION, SHOWING CANTILEVERED SOUTHERN (LEFT) AND NORTHERN (RIGHT) TRUSS SECTIONS. THE CENTRAL TRUSS SECTION IS OBSCURED BY TREES AT CENTER OF PHOTOGRAPH. FACING WEST. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

  5. 5. VIEW OF THE EASTERN BRIDGE ELEVATION, SHOWING CENTRAL CUT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF THE EASTERN BRIDGE ELEVATION, SHOWING CENTRAL CUT AND MORTARED STONE PIER AND ASSOCIATED STEEL SUPERSTRUCTURE (CENTER), AND CANTILEVERED NORTHERN TRUSS SECTION (RIGHT). FACING NORTHWEST. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

  6. 15. VIEW SOUTH, DETAIL OF REMNANTS OF EAST SIDE BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. VIEW SOUTH, DETAIL OF REMNANTS OF EAST SIDE BRIDGE ABUTMENT - Bald Eagle Cross-Cut Canal Lock, North of Water Street along West Branch of Susquehanna River South bank, 500 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA

  7. Mentoring as a Bridge to Understanding Cultural Difference

    ERIC Educational Resources Information Center

    Blake-Beard, Stacy

    2009-01-01

    Bridges are thresholds to other realities, archetypal, primal symbols of shifting consciousness. They are passageways, conduits, and connectors that connote transitioning, crossing borders, and changing perspectives (Anzaldua, 2002). At its best, mentoring serves as an important bridge in many of the ways described by Anzaldua. When asked to think…

  8. 23. 'General Drawing Of Proposed Three Hinged Arch Bridge At ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. 'General Drawing Of Proposed Three Hinged Arch Bridge At Parks Bar Crossing Over The Yuba River, Yuba County Cal., Thomas System, Thomas & Post, Consulting Engrs, Hibernian Building, Los Angeles, Oct. 18, 1912,' and marked 'Revised Oct. 22, 1912.' - Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

  9. 22. 'General Drawing Of Proposed Three Hinged Arch Bridge At ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. 'General Drawing Of Proposed Three Hinged Arch Bridge At Parks Bar Crossing Over The Yuba River, Yuba County Cal., Thomas System, Thomas & Post, Consulting Engrs, Hibernian Building, Los Angeles, Aug. 3, 1912.' - Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

  10. Interdisciplinary Studies and the Bridging Disciplines: A Matter of Process

    ERIC Educational Resources Information Center

    Youngblood, Dawn

    2007-01-01

    Bridging disciplines have much to teach regarding how to combine analytical tools to tackle problems and questions that cross traditional disciplinary boundaries. This article explores interdisciplinary aspects of two long established bridging disciplines--geography and anthropology--in order to consider what the relatively young undertaking…

  11. Crossing Digital Bridges for Global Understanding

    ERIC Educational Resources Information Center

    Beal, Candy; Bates, Natalie

    2010-01-01

    The international fantasy world that Walt Disney has developed, and others like it, are designed to create a global community experience for amusement park visitors. Disney's portrayal of many nations--their colorful dress, musical traditions, and unique native cuisine--is many students' only "foreign travel" and the experience may leave them with…

  12. Measuring the stress-bridging law of a heterogeneous material

    SciTech Connect

    Liu, C.

    2002-01-01

    In this investigation, fracture experiments on a high explosive material (PBX 9501) were conducted using the digital image correlation technique. From the experimental measurement, we are able to determine quantitatively the stress-bridging law (or decohesion law), which characterizes the relationship between the bridging stress and the opening displacement cross the bridging zone. The plastic bonded HMX (PBX) high explosives are composed of the energetic crystal (HMX) and a polymeric binder. Previous experimental observations showed that the fracture process in the sugar mock, a simulant of the PBX 9501 high explosive, is very different from that in brittle solids, even though the high explosive material PBX 9501 is quite brittle under tension. A close examination of the fracture surface revealed that before crack initiation and propagation, a very large damage region is developed ahead of the crack tip. Since such a damage region is very narrow, it can be modeled as a stress bridging zone. Due to the presence of the sizable bridging zone, conventional fracture mechanics is no longer applicable. Stress bridging has to be considered explicitly in order to understand of fracture processes in the PBX 9501 high explosive and the sugar mock. The model, which explicitly incorporates stress-bridging mechanism, is shown in Fig.1. In describing the model, one would need the following quantities, bridging zone length R, bridging stress {sigma}(x{sub 1}), bridging-zone opening displacement {sigma}(x{sub 1}), and the critical stress, {sigma}{sub C}, at which bridging zone starts to develop. Among these quantities, the key element for the bridging model is the relationship between the bridging stress {sigma} and the opening displacement cross the bridging zone {sigma}, i.e., {sigma}({delta}), or the stress-bridging law that can only be determined through experimental measurement. In this study, fracture experiments on PBX 9501 high explosive using the digital image correlation

  13. Salt bridge as a gatekeeper against partial unfolding.

    PubMed

    Hinzman, Mark W; Essex, Morgan E; Park, Chiwook

    2016-05-01

    Salt bridges are frequently observed in protein structures. Because the energetic contribution of salt bridges is strongly dependent on the environmental context, salt bridges are believed to contribute to the structural specificity rather than the stability. To test the role of salt bridges in enhancing structural specificity, we investigated the contribution of a salt bridge to the energetics of native-state partial unfolding in a cysteine-free version of Escherichia coli ribonuclease H (RNase H*). Thermolysin cleaves a protruding loop of RNase H(*) through transient partial unfolding under native conditions. Lys86 and Asp108 in RNase H(*) form a partially buried salt bridge that tethers the protruding loop. Investigation of the global stability of K86Q/D108N RNase H(*) showed that the salt bridge does not significantly contribute to the global stability. However, K86Q/D108N RNase H(*) is greatly more susceptible to proteolysis by thermolysin than wild-type RNase H(*) is. The free energy for partial unfolding determined by native-state proteolysis indicates that the salt bridge significantly increases the energy for partial unfolding by destabilizing the partially unfolded form. Double mutant cycles with single and double mutations of the salt bridge suggest that the partially unfolded form is destabilized due to a significant decrease in the interaction energy between Lys86 and Asp108 upon partial unfolding. This study demonstrates that, even in the case that a salt bridge does not contribute to the global stability, the salt bridge may function as a gatekeeper against partial unfolding that disturbs the optimal geometry of the salt bridge. PMID:26916981

  14. Measurement of the photon electroproduction cross section at JLAB with the goal of performing a Rosenbluth separation of the DVCS contribution

    SciTech Connect

    Jimenez-Arguello, Alejandro Marti

    2014-07-11

    experiment is the isolation of the contribution from the term coming form the DVCS from the interference term, resulting from the BH contribution. This isolation is known as "Rosenbluth Separation". The work presented in this thesis focuses on the analysis of the data stored by the electromagnetic calorimeter, employed for the detection of real photons. There is also a a theoretical introduction to the study of the nucleon structure, reviewing the concepts of form factors and parton distributions through elastic and inelastic processes. The computation of the photon leptoproduction cross section is described in detail, as well as the goals of experiment E07-007. This thesis also describes the analysis of the data stored by the electromagnetic calorimeter, with the purpose of obtaining the kinematic variables of the real photons resulting from DVCS reactions. Finally, it describes the selection of events from stored data, the applied cuts to kinematical variables and the background subtraction. Also, the process of extraction of the necessary observables for computing the photon leptoproduction cross section is described, along with the main steps followed to perform the Monte Carlo simulation used in this computation. The resulting cross sections are shown at the end of this thesis.

  15. 58. View of lined canal looking west from road bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    58. View of lined canal looking west from road bridge crossing lined canal. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  16. DETAIL OF THE UNDERSIDE OF THE BRIDGE, SHOWING IBEAMS AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF THE UNDERSIDE OF THE BRIDGE, SHOWING I-BEAMS AND WOODEN CROSS BEAMS. 110 - Burlington Northern Santa Fe Railroad, Cajon Subdivision, Structure No. 62.7, between Cajon Summit and Keenbrook, Devore, San Bernardino County, CA

  17. Interior view of skewed Baltimore truss of Bridge No. 1363, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of skewed Baltimore truss of Bridge No. 1363, First B&O Crossing, looking west. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  18. Health Professions Education: A Bridge to Quality

    ERIC Educational Resources Information Center

    Greiner, Ann C., Ed.; Knebel, Elisa, Ed.

    2003-01-01

    The Institute of Medicine study Crossing the Quality Chasm (2001) recommended that an interdisciplinary summit be held to further reform of health professions education in order to enhance quality and patient safety. Health Professions Education: A Bridge to Quality is the follow up to that summit, held in June 2002, where 150 participants across…

  19. Contribution of Upper-Body Strength, Body Composition, and Maximal Oxygen Uptake to Predict Double Poling Power and Overall Performance in Female Cross-Country Skiers.

    PubMed

    Østerås, Sindre; Welde, Boye; Danielsen, Jørgen; van den Tillaar, Roland; Ettema, Gertjan; Sandbakk, Øyvind

    2016-09-01

    Østerås, S, Welde, B, Danielsen, J, van den Tillaar, R, Ettema, G, and Sandbakk, Ø. Contribution of upper-body strength, body composition, and maximal oxygen uptake to predict double poling power and overall performance in female cross-country skiers. J Strength Cond Res 30(9): 2557-2564, 2016-Maximal oxygen uptake (V[Combining Dot Above]O2max) is regarded as the most performance-differentiating physiological measure in cross-country (XC) skiing. In addition, upper-body strength and lean mass have been associated with double poling (DP) power in XC skiers. In this study, we tested upper-body maximal strength, lean mass, and V[Combining Dot Above]O2max's contributions to predict DP power production of different durations and the overall XC skiing performance level of elite female XC skiers. Thirteen skiers (V[Combining Dot Above]O2max: 64.9 ± 4.2 ml·kg·min) performed one 30-second and one 3-minute DP performance test using a ski ergometer. The International Ski Federation's (FIS) ranking points determined their overall XC skiing performance. The skiers performed three 1-repetition maximal strength tests in poling-specific exercises that isolated the elbow extension, shoulder extension, and trunk flexion movements. Body composition was determined by a DXA scan, and V[Combining Dot Above]O2max was tested in an incremental running test. Multiple regressions were used to predict power production in the 30-second and 3-minute tests and FIS points. The 2 best predictions of 30-second DP power were lean upper-body mass and maximal upper-body strength (with the 3 strength tests normalized and pooled together as one variable) (R = 0.84 and 0.81, p < 0.001). Along with V[Combining Dot Above]O2max, the same 2 variables were the best predictions of both 3-minute DP power (R = 0.60 and 0.44, p ≤ 0.05) and overall XC skiing performance (R = 0.43 and 0.40, p ≤ 0.05). Although the importance of upper-body strength and lean mass to predict DP power production and the

  20. New oxa-bridged macrocycles.

    PubMed

    Panten, Johannes; Surburg, Horst; Hölscher, Bernd

    2008-06-01

    In creating new aroma molecules, the fragrance chemist can make use of several tools: receptor or combinatorial research as well as lead structure optimization of existing chemicals or substances from the natural pool. Sometimes, it is also possible to discover new structures via another way: the careful analysis of existing products and their production processes. In analyzing the production process of 1-oxacyclohexadecan-2-one (6), we identified at least two new oxa-bridged macrocyclic molecules. In continuation, these results inspired us to synthesize and evaluate more representatives with similar structures. In this contribution, presented at the RSC/SCI conference 'flavours & fragrances 2007' in London, September 24-26, 2007, the synthesis and olfactory properties of several new oxa-bridged macrocycles will be introduced and discussed. PMID:18618411

  1. Cross sectional study of contribution of clinical assessment and simple cardiac investigations to diagnosis of left ventricular systolic dysfunction in patients admitted with acute dyspnoea.

    PubMed Central

    Gillespie, N. D.; McNeill, G.; Pringle, T.; Ogston, S.; Struthers, A. D.; Pringle, S. D.

    1997-01-01

    OBJECTIVE: To assess the comparative contribution of clinical assessment, electrocardiography, and chest radiography to the diagnosis of left ventricular systolic dysfunction in patients admitted to a general medical ward with acute dyspnoea. DESIGN: Prospective cross sectional study. SETTING: Acute medical admissions ward of a teaching hospital. SUBJECTS: 71 randomly selected patients admitted with acute dyspnoea. MAIN OUTCOME MEASURES: Sensitivity and specificity of each investigation and logistic regression analysis of each variable in identifying left ventricular systolic dysfunction. RESULTS: Clinical assessment in this cohort of patients with severe dyspnoea was generally sensitive (sensitivity 81%). Patients were divided into three groups on the basis of clinical assessment. In the first group (37 patients) the diagnosis of systolic dysfunction was clear, in the second (22) it was in doubt, and in the third (12) it was unlikely. The sensitivity of clinical assessment in identifying left ventricular systolic dysfunction was 81% and the specificity was 47%. The specificity of diagnosis was improved by electrocardiography (69%) and chest radiography (92%). Logistic regression analysis showed that isolated pulmonary crepitations were a comparatively poor predictor of left ventricular systolic dysfunction chi 2 = 10.215, P = 0.0014) but that a full clinical examination had reasonable predictive value (chi 2 = 24.82, P < 0.00001). The combination of clinical assessment and chest radiography improved the accuracy of diagnosis (chi 2 = 28.08, P < 0.00001), as did the combination of clinical assessment and electrocardiography (chi 2 = 32.41, P < 0.00001). CONCLUSION: Clinical assessment in patients admitted with acute dyspnoea is comparatively accurate. Patients with abnormal results on chest radiography, electrocardiography, and clinical examination have a high likelihood of having left ventricular systolic dysfunction. Echocardiography contributes little more to

  2. Adsorption of polymeric brushes: Bridging

    NASA Astrophysics Data System (ADS)

    Johner, Albert; Joanny, Jean-François

    1992-04-01

    We study the adsorption of grafted polymer layers on a planar surface parallel to the grafting surface. The layer consists of two types of chains: nonadsorbed chains with a free end and adsorbed chains forming bridges between the two plates. In the limit of strong adsorption a dead zone exists in the vicinity of the adsorbing plate; its size increases with the adsorption strength. Two adsorption mechanisms are possible: adsorption of the last monomer only and adsorption of all the monomers. In both cases the adsorption regimes at equilibrium (when no external force acts on the plates) are discussed within the framework of the self-consistent mean-field theory. We also give scaling laws taking into account excluded volume correlations. Finally, we consider situations where a finite external force, either tangential or normal to the plates, is applied on the adsorbing plate. Pulling and tangential forces both reduce the fraction of bridges and eventually lead to rupture, whereas compressional forces favor bridging. For normal forces, force vs distance profiles between planes and crossed cylinders are given.

  3. Semiconductor bridge (SCB) detonator

    DOEpatents

    Bickes, Jr., Robert W.; Grubelich, Mark C.

    1999-01-01

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length.

  4. Semiconductor bridge (SCB) detonator

    DOEpatents

    Bickes, R.W. Jr.; Grubelich, M.C.

    1999-01-19

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge (SCB) igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length. 3 figs.

  5. Galactic Bridges in Pairs

    NASA Astrophysics Data System (ADS)

    Thierjung, Brianna; Jorge Moreno, Paul Torrey, Phil Hopkins

    2016-01-01

    We employ a suite of 75 simulations of galaxies in idealized major mergers to investigate the bridges formed by interactions. These simulations are based on the Feedback in Realistic Environments (FIRE) model (Hopkins et al. 2011). Moreover, unlike past work, we have both the resolution and diversity in merging orbits to make statistically meaningful predictions. We find that very dense, star forming bridges can be characterized as strong bridges. In particular, prograde mergers with high eccentricities and high impact parameters produce the most mass of stars in the bridge.

  6. The perfectionism model of binge eating: testing unique contributions, mediating mechanisms, and cross-cultural similarities using a daily diary methodology.

    PubMed

    Sherry, Simon B; Sabourin, Brigitte C; Hall, Peter A; Hewitt, Paul L; Flett, Gordon L; Gralnick, Tara M

    2014-12-01

    The perfectionism model of binge eating (PMOBE) is an integrative model explaining the link between perfectionism and binge eating. This model proposes socially prescribed perfectionism confers risk for binge eating by generating exposure to 4 putative binge triggers: interpersonal discrepancies, low interpersonal esteem, depressive affect, and dietary restraint. The present study addresses important gaps in knowledge by testing if these 4 binge triggers uniquely predict changes in binge eating on a daily basis and if daily variations in each binge trigger mediate the link between socially prescribed perfectionism and daily binge eating. Analyses also tested if proposed mediational models generalized across Asian and European Canadians. The PMOBE was tested in 566 undergraduate women using a 7-day daily diary methodology. Depressive affect predicted binge eating, whereas anxious affect did not. Each binge trigger uniquely contributed to binge eating on a daily basis. All binge triggers except for dietary restraint mediated the relationship between socially prescribed perfectionism and change in daily binge eating. Results suggested cross-cultural similarities, with the PMOBE applying to both Asian and European Canadian women. The present study advances understanding of the personality traits and the contextual conditions accompanying binge eating and provides an important step toward improving treatments for people suffering from eating binges and associated negative consequences. PMID:25243835

  7. Associations between aspects of pain and cognitive performance and the contribution of depressive symptoms in mid-life women: a cross-sectional analysis.

    PubMed

    Tomey, Kristin; Greendale, Gail A; Kravitz, Howard M; Bromberger, Joyce T; Burns, John W; Dugan, Sheila A; de Leon, Carlos F Mendes

    2015-01-01

    Pain has been associated with cognitive problems in pain patients. This study evaluated the extent to which experiences of pain are associated with cognitive performance in a community sample of mid-life women, and the contribution of depressive symptoms to this association. A cross-sectional analysis was used with data from the Study of Women's Health Across the Nation (SWAN). Associations between aspects of pain and cognitive performance were evaluated using statistical models with and without depressive symptoms. The cognitive performance score was a composite of three cognitive tests, the Digit Span Backward Test, the Symbol Digit Modalities Test and the East Boston Memory Test. Greater pain experiences that interfered with daily work were independently associated with poorer cognitive performance, [β (SE) -0.074 (0.021); p value<0.01] and this association was partially explained by depressive symptoms [β (SE) -0.061 (0.022); p value<0.01 after adjusting for depressive symptoms]. Additionally, an independent association between a greater composite pain score and poorer cognitive performance was identified without adjusting for depressive symptoms, [β (SE) -0.002 (0.0009); p value<0.05] but was no longer significant after adjusting for depressive symptoms. Our results suggest that in mid-life women, greater pain is associated with poorer cognitive performance, and depressive symptoms play an important role in this association. Clinicians should be aware of these relationships when evaluating patients. PMID:25466300

  8. 75 FR 39555 - Environmental Impact Statement; Fort Hamer Bridge, Manatee County, FL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-09

    ... in the January 17, 2008 issue of the Federal Register (73 FR 3316). Information on service for... SECURITY Coast Guard Environmental Impact Statement; Fort Hamer Bridge, Manatee County, FL AGENCY: Coast... Guard announces its intent to prepare an EIS for a proposed new bridge (Fort Hamer Bridge) crossing...

  9. 78 FR 65420 - Environmental Impact Statement, Portageville Bridge Project (Wyoming and Livingston Counties, New...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... Federal Highway Administration Environmental Impact Statement, Portageville Bridge Project (Wyoming and... provide a modern rail crossing at the location of the existing Portageville Bridge (also known as the ``Portage High Bridge'') over the Genesee River in Wyoming and Livingston Counties, New York. FOR...

  10. GOETHALS BRIDGE FROM NORTH SIDE OVER ARTHUR KILL. RAILROAD BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GOETHALS BRIDGE FROM NORTH SIDE OVER ARTHUR KILL. RAILROAD BRIDGE IN FOREGROUND - Goethals Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

  11. Plans: Poop Deck, Boat Deck, Housetop, Bridge Deck, Upper Bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Plans: Poop Deck, Boat Deck, Housetop, Bridge Deck, Upper Bridge Deck, Navigating Bridge, Forecastle Deck, Upper Deck, Second Deck and Hold - Saugatuck, James River Reserve Fleet, Newport News, Newport News, VA

  12. 2. LONG VIEW NORTHWEST, EASTBOUND BRIDGE IN FOREGROUND, WESTBOUND BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. LONG VIEW NORTHWEST, EASTBOUND BRIDGE IN FOREGROUND, WESTBOUND BRIDGE IN BACKGROUND - Willow Run Expressway Bridge No. R01, Spanning Conrail Railway, eastbound, at US-10, Ypsilanti, Washtenaw County, MI

  13. 3. View of Clark Fork Vehicle Bridge facing southwest. Bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View of Clark Fork Vehicle Bridge facing southwest. Bridge from north shore of Clark Fork River. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  14. 4. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. View of Clark Fork Vehicle Bridge facing northeast. Bridge from south shoreof Clark Fork River showing 4 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  15. 2. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. View of Clark Fork Vehicle Bridge facing northeast. Bridge from south shore of Clark Fork River showing 4 1/2 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  16. 7. View of Clark Fork Vehicle Bridge facing northwest. Bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. View of Clark Fork Vehicle Bridge facing northwest. Bridge from south shore of Clark Fork River showing 4 1/2 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  17. LOOKING WEST, BETWEEN READING DEPOT BRIDGE AND SKEW ARCH BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOOKING WEST, BETWEEN READING DEPOT BRIDGE AND SKEW ARCH BRIDGE (HAER No. PA-116). - Philadelphia & Reading Railroad, Reading Depot Bridge, North Sixth Street at Woodward Street, Reading, Berks County, PA

  18. APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM BELOW, SHOWING VALVE TOWER TO RIGHT. VIEW FACING NORTH - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  19. APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM ENTRY. VIEW FACING NORTHWEST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  20. 11. Southern bridge abutment and arches, taken from old bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Southern bridge abutment and arches, taken from old bridge abutment looking south. - Presumpscot Falls Bridge, Spanning Presumptscot River at Allen Avenue extension, 0.75 mile west of U.S. Interstate 95, Falmouth, Cumberland County, ME

  1. VIEW OF APALACHICOLA RIVER BRIDGE STEEL BRIDGE TRUSS AND ROADWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF APALACHICOLA RIVER BRIDGE STEEL BRIDGE TRUSS AND ROADWAY AT PIER 3, EAST SIDE, FROM RIVER, FACING WEST - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  2. TWIN SKEWED TRUSS RAILROAD BRIDGES NEAR BRIDGE STREET AT THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TWIN SKEWED TRUSS RAILROAD BRIDGES NEAR BRIDGE STREET AT THE WEST END OF THE PLANT. THIS VIEW PROBABLY LOOKING NORTHWEST. BRIDGES BUILT OVER ERIE CANAL (WHICH FLOWED RIGHT THROUGH THE MIDDLE OF THE PLANT) BY AMERICAN BRIDGE COMPANY IN 1902. SINCE THIS PHOTO WAS TAKEN, NEAR BRIDGE HAS BEEN DEMOLISHED; FAR BRIDGE IS STILL IN SERVICE. - Solvay Process Company, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  3. Precision bolometer bridge

    NASA Technical Reports Server (NTRS)

    White, D. R.

    1968-01-01

    Prototype precision bolometer calibration bridge is manually balanced device for indicating dc bias and balance with either dc or ac power. An external galvanometer is used with the bridge for null indication, and the circuitry monitors voltage and current simultaneously without adapters in testing 100 and 200 ohm thin film bolometers.

  4. Virtual Bridge Design Challenge

    ERIC Educational Resources Information Center

    Mitts, Charles R.

    2013-01-01

    This design/problem-solving activity challenges students to design a replacement bridge for one that has been designated as either structurally deficient or functionally obsolete. The Aycock MS Technology/STEM Magnet Program Virtual Bridge Design Challenge is an authentic introduction to the engineering design process. It is a socially relevant…

  5. Active-bridge oscillator

    DOEpatents

    Wessendorf, Kurt O.

    2001-01-01

    An active bridge oscillator is formed from a differential amplifier where positive feedback is a function of the impedance of one of the gain elements and a relatively low value common emitter resistance. This use of the nonlinear transistor parameter h stabilizes the output and eliminates the need for ALC circuits common to other bridge oscillators.

  6. Low-momentum-transfer nonrelativistic limit of the relativistic impulse approximation expression for Compton-scattering doubly differential cross sections and characterization of their relativistic contributions

    NASA Astrophysics Data System (ADS)

    Lajohn, L. A.

    2010-04-01

    The nonrelativistic (nr) impulse approximation (NRIA) expression for Compton-scattering doubly differential cross sections (DDCS) for inelastic photon scattering is recovered from the corresponding relativistic expression (RIA) of Ribberfors [Phys. Rev. B 12, 2067 (1975)] in the limit of low momentum transfer (q→0), valid even at relativistic incident photon energies ω1>m provided that the average initial momentum of the ejected electron is not too high, that is, m using nr expressions when θ is small. For example, a 1% accuracy can be obtained when ω1=1MeV if θ<20°. However as ω1 increases into the MeV range, the maximum θ at which an accurate Compton peak can be obtained from nr expressions approaches closer to zero, because the θ at which the relativistic shift of CP to higher energy is greatest, which starts at 180° when ω1<300 keV, begins to decrease, approaching zero even though the θ at which the relativistic increase in the CP magnitude remains greatest around θ=180°. The relativistic contribution to the prediction of Compton doubly differential cross sections (DDCS) is characterized in simple terms using Ribberfors further approximation to his full RIA expression. This factorable form is given by DDCS=KJ, where K is the kinematic factor and J the Compton profile. This form makes it possible to account for the relativistic shift of CP to higher energy and the increase in the CP magnitude as being due to the dependence of J(pmin,ρrel) (where pmin is the relativistic version of the z component of the momentum of the initial electron and ρrel is the relativistic charge density) and K(pmin) on pmin. This characterization approach was used as a guide

  7. Low-momentum-transfer nonrelativistic limit of the relativistic impulse approximation expression for Compton-scattering doubly differential cross sections and characterization of their relativistic contributions

    SciTech Connect

    LaJohn, L. A.

    2010-04-15

    The nonrelativistic (nr) impulse approximation (NRIA) expression for Compton-scattering doubly differential cross sections (DDCS) for inelastic photon scattering is recovered from the corresponding relativistic expression (RIA) of Ribberfors [Phys. Rev. B 12, 2067 (1975)] in the limit of low momentum transfer (q{yields}0), valid even at relativistic incident photon energies {omega}{sub 1}>m provided that the average initial momentum of the ejected electron is not too high, that is, m using nr expressions when {theta} is small. For example, a 1% accuracy can be obtained when {omega}{sub 1}=1 MeV if {theta}<20 deg. However as {omega}{sub 1} increases into the MeV range, the maximum {theta} at which an accurate Compton peak can be obtained from nr expressions approaches closer to zero, because the {theta} at which the relativistic shift of CP to higher energy is greatest, which starts at 180 deg. when {omega}{sub 1}<300 keV, begins to decrease, approaching zero even though the {theta} at which the relativistic increase in the CP magnitude remains greatest around {theta}=180 deg. The relativistic contribution to the prediction of Compton doubly differential cross sections (DDCS) is characterized in simple terms using Ribberfors further approximation to his full RIA expression. This factorable form is given by DDCS=KJ, where K is the kinematic factor and J the Compton profile. This form makes it possible to account for the relativistic shift of CP to higher energy and the increase in the CP magnitude as being due to the dependence of J(p{sub min},{rho}{sub rel}) (where p{sub min} is the relativistic version of the z

  8. LODGEPOLE BRIDGE, FACING SOUTHEAST Generals Highway, Lodge Pole Bridge, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LODGEPOLE BRIDGE, FACING SOUTHEAST - Generals Highway, Lodge Pole Bridge, Spanning Marble Fork of Kaweah River, approximately 21 miles northwest of Ash Mountain Entrance, Three Rivers, Tulare County, CA

  9. LODGEPOLE BRIDGE, FACING NORTHWEST Generals Highway, Lodge Pole Bridge, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LODGEPOLE BRIDGE, FACING NORTHWEST - Generals Highway, Lodge Pole Bridge, Spanning Marble Fork of Kaweah River, approximately 21 miles northwest of Ash Mountain Entrance, Three Rivers, Tulare County, CA

  10. Sulphite Railroad Bridge1896, Title Sheet Sulphite Railroad Bridge, Former ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Sulphite Railroad Bridge-1896, Title Sheet - Sulphite Railroad Bridge, Former Boston & Maine Railroad (originally Tilton & Franklin Railroad) spanning Winnipesautee River, Franklin, Merrimack County, NH

  11. Fractal-like kinetics of intracellular enzymatic reactions: a chemical framework of endotoxin tolerance and a possible non-specific contribution of macromolecular crowding to cross-tolerance

    PubMed Central

    2013-01-01

    Background The response to endotoxin (LPS), and subsequent signal transduction lead to the production of cytokines such as tumor necrosis factor-α (TNF-α) by innate immune cells. Cells or organisms pretreated with endotoxin enter into a transient state of hyporesponsiveness, referred to as endotoxin tolerance (ET) which represents a particular case of negative preconditioning. Despite recent progress in understanding the molecular basis of ET, there is no consensus yet on the primary mechanism responsible for ET and for the more complex cases of cross tolerance. In this study, we examined the consequences of the macromolecular crowding (MMC) and of fractal-like kinetics (FLK) of intracellular enzymatic reactions on the LPS signaling machinery. We hypothesized that this particular type of enzyme kinetics may explain the development of ET phenomenon. Method Our aim in the present study was to characterize the chemical kinetics framework in ET and determine whether fractal-like kinetics explains, at least in part, ET. We developed an ordinary differential equations (ODE) mathematical model that took into account the links between the MMC and the LPS signaling machinery leading to ET. We proposed that the intracellular fractal environment (MMC) contributes to ET and developed two mathematical models of enzyme kinetics: one based on Kopelman’s fractal-like kinetics framework and the other based on Savageau’s power law model. Results Kopelman’s model provides a good image of the potential influence of a fractal intracellular environment (MMC) on ET. The Savageau power law model also partially explains ET. The computer simulations supported the hypothesis that MMC and FLK may play a role in ET. Conclusion The model highlights the links between the organization of the intracellular environment, MMC and the LPS signaling machinery leading to ET. Our FLK-based model does not minimize the role of the numerous negative regulatory factors. It simply draws attention to

  12. 14. UNDERSIDE, SHOWING PIERS, CROSS BEAMS, AND CANTILEVERED EXTENSION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. UNDERSIDE, SHOWING PIERS, CROSS BEAMS, AND CANTILEVERED EXTENSION OF BRIDGE FOR ACCESS TO WAREHOUSE, LOOKING NORTH - Appomattox Bridge, U.S. Route 1 over Appomattox River, Petersburg, Petersburg, VA

  13. Associations between aspects of pain and cognitive performance and the contribution of depressive symptoms in mid-life women: A cross-sectional analysis

    PubMed Central

    Tomey, Kristin; Greendale, Gail A.; Kravitz, Howard M.; Bromberger, Joyce T; Burns, John W.; Dugan, Sheila A.; de Leon, Carlos F. Mendes

    2014-01-01

    Objectives Pain has been associated with cognitive problems in pain patients. This study evaluated the extent to which experiences of pain are associated with cognitive performance in a community sample of mid-life women, and the contribution of depressive symptoms to this association. Study Design A cross-sectional analysis was used with data from the Study of Women’s Health Across the Nation (SWAN). Associations between aspects of pain and cognitive performance were evaluated using statistical models with and without depressive symptoms. Main Outcome Measures The cognitive performance score was a composite of three cognitive tests, the Digit Span Backward Test, the Symbol Digit Modalities Test and the East Boston Memory Test. Results Greater pain experiences that interfered with daily work were independently associated with poorer cognitive performance, [β (SE) −0.074 (0.021); p value <0.01] and this association was partially explained by depressive symptoms [β (SE) −0.061 (0.022); p value <0.01 after adjusting for depressive symptoms]. Additionally, an independent association between a greater composite pain score and poorer cognitive performance was identified without adjusting for depressive symptoms, [β (SE) −0.002 (0.0009); p value <0.05] but was no longer significant after adjusting for depressive symptoms. Conclusions Our results suggest that in mid-life women, greater pain is associated with poorer cognitive performance, and depressive symptoms play an important role in this association. Clinicians should be aware of these relationships when evaluating patients. PMID:25466300

  14. Identifying hidden sexual bridging communities in Chicago.

    PubMed

    Youm, Yoosik; Mackesy-Amiti, Mary Ellen; Williams, Chyvette T; Ouellet, Lawrence J

    2009-07-01

    Bridge populations can play a central role in the spread of human immunodeficiency virus (HIV) by providing transmission links between higher and lower prevalence populations. While social network methods are well suited to the study of bridge populations, analyses tend to focus on dyads (i.e., risk between drug and/or sex partners) and ignore bridges between distinct subpopulations. This study takes initial steps toward moving the analysis of sexual network linkages beyond individual and risk group levels to a community level in which Chicago's 77 community areas are examined as subpopulations for the purpose of identifying potential bridging communities. Of particular interest are "hidden" bridging communities; that is, areas with above-average levels of sexual ties with other areas but whose below-average AIDS prevalence may hide their potential importance for HIV prevention. Data for this analysis came from the first wave of recruiting at the Chicago Sexual Acquisition and Transmission of HIV Cooperative Agreement Program site. Between August 2005 through October 2006, respondent-driven sampling was used to recruit users of heroin, cocaine, or methamphetamine, men who have sex with men regardless of drug use, the sex partners of these two groups, and sex partners of the sex partners. In this cross-sectional study of the sexual transmission of HIV, participants completed a network-focused computer-assisted self-administered interview, which included questions about the geographic locations of sexual contacts with up to six recent partners. Bridging scores for each area were determined using a matrix representing Chicago's 77 community areas and were assessed using two measures: non-redundant ties and flow betweenness. Bridging measures and acquired immunodeficiency syndrome (AIDS) case prevalence rates were plotted for each community area on charts representing four conditions: below-average bridging and AIDS prevalence, below-average bridging and above

  15. 5. View of Clark Fork Vehicle Bridge facing east. Bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View of Clark Fork Vehicle Bridge facing east. Bridge from south shore of Clark Fork River-southernmost span. 1900-era Northern Pacific Railway Bridge in background. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  16. A thermomechanical cohesive zone model for bridged delamination cracks

    NASA Astrophysics Data System (ADS)

    Hattiangadi, Ashwin; Siegmund, Thomas

    2004-03-01

    The coupled thermomechanical numerical analysis of composite laminates with bridged delamination cracks loaded by a temperature gradient is described. The numerical approach presented is based on the framework of a cohesive zone model. A traction-separation law is presented which accounts for breakdown of the micromechanisms responsible for load transfer across bridged delamination cracks. The load transfer behavior is coupled to heat conduction across the bridged delamination crack. The coupled crack-bridging model is implemented into a finite element framework as a thermomechanical cohesive zone model (CZM). The fundamental response of the thermomechanical CZM is described. Subsequently, bridged delamination cracks of fixed lengths are studied. Values of the crack tip energy release rate and of the crack heat flux are computed to characterize the loading of the structure. Specimen geometries are considered that lead to crack opening through bending deformation and buckling delamination. The influence of critical mechanical and thermal parameters of the bridging zone on the thermomechanical delamination behavior is discussed. Bridging fibers not only contribute to crack conductance, but by keeping the crack opening small they allow heat flux across the delamination crack to be sustained longer, and thereby contribute to reduced levels of thermal stresses. The micro-mechanism based cohesive zone model allows the assessment of the effectiveness of the individual mechanisms contributing to the thermomechanical crack bridging embedded into the structural analysis.

  17. [The multiple promontory bridge].

    PubMed

    Wysocki, J

    1998-01-01

    Anatomical investigations of one hundred human temporal bones revealed a significant variability of the promontory bridge (ponticulus promontorii). In twelve bones double and in two-triple promontory bridge was observed. The triple promontory bridge had not been previously described in available literature. In all the cases the double or triple promontory bridges were observed only on the temporal bones obtained from cadavers of up to four years of age. It confirms previous statements suggesting that development of this structure is connected with the process of pneumatization of the statements suggesting that development of this structure is connected with the process of pneumatization of the temporal bone, which obviously starts in 3-4 year of life. PMID:9884587

  18. 4. VIEW OF THE WEST FACADE. NOTE THE BRIDGES FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF THE WEST FACADE. NOTE THE BRIDGES FROM THE D.L. & W. R.R. WOODWARD SIDING AND MAIN LINE IN THE LEFT FOREGROUND. PHOTO IS FROM THE LEVEE CROSSING TOBY CREEK FACING EAST. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

  19. Truck-based mobile wireless sensor networks for the experimental observation of vehicle-bridge interaction

    NASA Astrophysics Data System (ADS)

    Kim, Junhee; Lynch, Jerome P.; Lee, Jong-Jae; Lee, Chang-Geun

    2011-06-01

    Heavy vehicles driving over a bridge create a complex dynamic phenomenon known as vehicle-bridge interaction. In recent years, interest in vehicle-bridge interaction has grown because a deeper understanding of the phenomena can lead to improvements in bridge design methods while enhancing the accuracy of structural health monitoring techniques. The mobility of wireless sensors can be leveraged to directly monitor the dynamic coupling between the moving vehicle and the bridge. In this study, a mobile wireless sensor network is proposed for installation on a heavy truck to capture the vertical acceleration, horizontal acceleration and gyroscopic pitching of the truck as it crosses a bridge. The vehicle-based wireless monitoring system is designed to interact with a static, permanent wireless monitoring system installed on the bridge. Specifically, the mobile wireless sensors time-synchronize with the bridge's wireless sensors before transferring the vehicle response data. Vertical acceleration and gyroscopic pitching measurements of the vehicle are combined with bridge accelerations to create a time-synchronized vehicle-bridge response dataset. In addition to observing the vehicle vibrations, Kalman filtering is adopted to accurately track the vehicle position using the measured horizontal acceleration of the vehicle and positioning information derived from piezoelectric strip sensors installed on the bridge deck as part of the bridge monitoring system. Using the Geumdang Bridge (Korea), extensive field testing of the proposed vehicle-bridge wireless monitoring system is conducted. Experimental results verify the reliability of the wireless system and the accuracy of the vehicle positioning algorithm.

  20. Measurement of the $s$-channel Single Top Quark Cross Section at the CDF Experiment and Contributions to the Evidence of $H\\rightarrow bb$ at the Tevatron

    SciTech Connect

    Liu, Hao

    2014-08-01

    In this thesis, we present the measurement of the s-channel single top quark production cross section. In the cross section measurement we use data generated by protonantiproton collisions at the center-of-mass energy √s = 1.96 TeV and collected by the CDF Run II detector. The total data set corresponds to an integrated luminosity of 9.4 fb-1.

  1. Corrosion prevention of Oregon's reinforced coastal bridges

    SciTech Connect

    Bullard, Sophie J.; Cramer, Stephen D.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Ziomek-Moroz, Margaret; Cryer. C.B; Gallardo, M. L.

    2004-06-01

    The Oregon Department of Transportation (Oregon DOT) maintains more than 120 coastal bridges; many are reinforced concrete structures over 15 m (50 ft) in length. Twelve of these bridges are historic structures. Oregon DOT is concerned about the ongoing deterioration of these bridges, rising maintenance and repair costs, and the need to protect Oregon’s large investment in coastal bridges. Over 80,000 m2 (850,000 ft2) of coastal bridge surface have been repaired and protected from further chloride-induced corrosion damage by using conductive coating anodes. Most of the anode area is thermal-sprayed (TS) Zn. Other anode materials include TS Ti, Zn-hydrogel, and conductive carbon paint. TS Zn anodes are estimated to have a service life exceeding 25 years but exhibit increasing anode polarization with age. Catalyzed TS Ti anodes develop no significant anode polarization and have exhibited stable long-term performance over 8 years of service. Galvanic Zn-hydrogel anodes produce a stable protection current with no evidence of aging effects over 6 years of service. The conductive carbon paint anode operates at a low anode current density and consumption rate with a low rate of acidification at the anode-concrete interface, which has contributed to a stable protection current over 17 years of service.

  2. What Contributes to the Activeness of Ethnic Minority Patients with Chronic Illnesses Seeking Allied Health Services? A Cross-Sectional Study in Rural Western China.

    PubMed

    Tang, Shangfeng; Dong, Dong; Ji, Lu; Fu, Hang; Feng, Zhanchun; Bishwajit, Ghose; He, Zhifei; Ming, Hui; Fu, Qian; Xian, Yue

    2015-09-01

    Actively seeking health services lies at the core of effective models of chronic disease self-management and contributes to promoting the utilization of allied health services (AHS). However, the use of AHS by ethnic minority Chinese, especially the elderly living in rural areas, has not received much attention. This study, therefore, aims to explore the association between personal characteristics and the activeness of ethnic minority patients with chronic diseases in rural areas of western China seeking AHS. A cross-sectional study was conducted to collect data on the socio-demographic and economic characteristics, health knowledge level and health communication channels of the sampled patients. A logistic regression model was used to examine the association of these predictors with the activeness of the surveyed patients in seeking AHS. A total of 1078 ethnic minorities over 45 years old who had chronic conditions were randomly selected from three western provinces in China and were interviewed in 2014. It is found that the New Cooperative Medical Scheme (NCMS) is the most salient predictor affecting the activeness of Chinese ethnic minorities in seeking AHS. The probability is 8.51 times greater for those insured with NCMS to actively seek AHS than those without (95% Confidence Interval (CI) 4.76-15.21; p < 0.001). Moreover, participants between 60 and 70 years old and those who have five to six household members are more likely to seek AHS compared with other social groups (Odds Ratio (OR) = 1.64, 95% CI 1.28-2.97, p = 0.007; OR = 1.95, 95% CI 1.15-2.36, p = 0.002). However, the activeness of patients seeking AHS is lower for those who have better household economic conditions. Besides socio-demographic predictors, the Chinese ethnic minorities' activeness in seeking AHS is clearly associated with the communication channels used for receiving health information, which include direct communication with doctors (OR = 5.18, 95% CI 3.58-7.50, p < 0.001) and

  3. What Contributes to the Activeness of Ethnic Minority Patients with Chronic Illnesses Seeking Allied Health Services? A Cross-Sectional Study in Rural Western China

    PubMed Central

    Tang, Shangfeng; Dong, Dong; Ji, Lu; Fu, Hang; Feng, Zhanchun; Bishwajit, Ghose; He, Zhifei; Ming, Hui; Fu, Qian; Xian, Yue

    2015-01-01

    Actively seeking health services lies at the core of effective models of chronic disease self-management and contributes to promoting the utilization of allied health services (AHS). However, the use of AHS by ethnic minority Chinese, especially the elderly living in rural areas, has not received much attention. This study, therefore, aims to explore the association between personal characteristics and the activeness of ethnic minority patients with chronic diseases in rural areas of western China seeking AHS. A cross-sectional study was conducted to collect data on the socio-demographic and economic characteristics, health knowledge level and health communication channels of the sampled patients. A logistic regression model was used to examine the association of these predictors with the activeness of the surveyed patients in seeking AHS. A total of 1078 ethnic minorities over 45 years old who had chronic conditions were randomly selected from three western provinces in China and were interviewed in 2014. It is found that the New Cooperative Medical Scheme (NCMS) is the most salient predictor affecting the activeness of Chinese ethnic minorities in seeking AHS. The probability is 8.51 times greater for those insured with NCMS to actively seek AHS than those without (95% Confidence Interval (CI) 4.76–15.21; p < 0.001). Moreover, participants between 60 and 70 years old and those who have five to six household members are more likely to seek AHS compared with other social groups (Odds Ratio (OR) = 1.64, 95% CI 1.28–2.97, p = 0.007; OR = 1.95, 95% CI 1.15–2.36, p = 0.002). However, the activeness of patients seeking AHS is lower for those who have better household economic conditions. Besides socio-demographic predictors, the Chinese ethnic minorities’ activeness in seeking AHS is clearly associated with the communication channels used for receiving health information, which include direct communication with doctors (OR = 5.18, 95% CI 3.58–7.50, p < 0

  4. 15. STRESS SHEET. American Bridge Company, New York Office, 30 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. STRESS SHEET. American Bridge Company, New York Office, 30 Church Street, sheet no. C516, dated March 12, 1928, approved March 16, 1928, order no. F5073. For U.S. Steel Products Company, Pacific Coast Depot. For Southern Pacific Company, Pacific Lines, 1st crossing, Napa River, near Napa, Western Division, customer's order no. 8873-P-28746. Various scales. - Napa River Railroad Bridge, Spanning Napa River, east of Soscol Avenue, Napa, Napa County, CA

  5. 40. SACRAMENTO APPROACH TO BRIDGE, SHOWING M STREET (NOW CAPITOL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. SACRAMENTO APPROACH TO BRIDGE, SHOWING M STREET (NOW CAPITOL MALL) APPROACHING FROM LOWER RIGHT, WATCHMAN'S SHANTY AT CENTER, TRACKS OF SACRAMENTO NORTHERN RAILWAY ALONG CENTERLINE OF M STREET AND BRIDGE, AND TRACKS OF SOUTHERN PACIFIC RAILROAD CROSSING M STREET ON FRONT STREET. RIVER LINES BUILDING AT LEFT WAS SACRAMENTO TERMINAL FOR RIVER STEAMERS DELTA QUEEN AND DELTA KING. Pencil and wash drawing by project architect Alfred Eichler, 1935. - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

  6. 49 CFR 213.353 - Turnouts, crossovers, and lift rail assemblies or other transition devices on moveable bridges.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... other transition devices on moveable bridges. 213.353 Section 213.353 Transportation Other Regulations... rail assemblies or other transition devices on moveable bridges. (a) In turnouts and track crossings... other transition devices on moveable bridges, the track owner shall prepare an inspection...

  7. The "Why" and "Where" of the Tappan Zee Bridge: A Lesson in Site Location, Physical Geography, and Politics

    ERIC Educational Resources Information Center

    Mitchell, Jerry T.; Cantrill, Jeremy; Kearse, Justin

    2012-01-01

    Bridges are some of the most majestic features in the American landscape. For classrooms, the bridge serves as an important component of one of the main themes of geography: movement. One bridge, north of Manhattan and crossing the Hudson River, is the Tappan Zee. One aspect that stands out in a way that does not at all appear reasonable: the…

  8. Operation IceBridge Alaska

    NASA Astrophysics Data System (ADS)

    Larsen, C.

    2015-12-01

    The University of Alaska Fairbanks (UAF) has flown LiDAR missions for Operation IceBridge in Alaska each year since 2009, expanding upon UAF's airborne laser altimetry program which started in 1994. These observations show that Alaska's regional mass balance is -75+11/-16 Gt yr-1 (1994-2013) (Larsen et al., 2015). A surprising result is that the rate of surface mass loss observed on non-tidewater glaciers in Alaska is extremely high. At these rates, Alaska contributes ~1 mm to global sea level rise every 5 years. Given the present lack of adequate satellite resources, Operation IceBridge airborne surveys by UAF are the most effective and efficient method to monitor this region's impact on global sea level rise. Ice depth measurements using radar sounding have been part of these airborne surveys since 2012. Many of Alaska's tidewater glaciers are bedded significantly below sea level. The depth and extent of glacier beds below sea level are critical factors in the dynamics of tidewater retreat. Improved radar processing tools are being used to predict clutter using forward simulation. This is essential to properly sort out true bed returns, which are often masked or obscured by valley wall returns. This presentation will provide an overview of the program, highlighting recent findings and observations from the most recent campaigns, and focusing on techniques used for the extrapolation of surface elevation changes to regional mass balances.

  9. Bridge inspection in Kansas

    NASA Astrophysics Data System (ADS)

    Whisler, Don E.

    1995-05-01

    The purpose of this paper is to give the reader a brief insight into the Kansas Department of Transportation (KDOT) Bridge Inspection Program. The State of Kansas has 25,580 bridge length structures within its boundaries used to carry vehicle traffic or pedestrians, excluding railroad. This total ranks third within the nation according to the November issue of 'Better Roads.' The total number of structures listed includes 20,453 structures owned by local governments, 340 structures owned by the Kansas Turnpike Authority, and 4,787 structures owned by the KDOT. This paper will deal specifically with the KDOT structures only.

  10. A Cross-Cultural Experimental Approach to the Contribution of Health, Religion and Personal Relations to Subjective Satisfaction with Life as a Whole

    ERIC Educational Resources Information Center

    Theuns, Peter; Baran, Barbara; Van Vaerenbergh, Rebecca; Hellenbosch, Greet; Tiliouine, Habib

    2012-01-01

    In cross-cultural research on quality of life, researchers must deal with the fundamental incomparability of subjective wellbeing assessments across cultural groups. This incompatibility most probably results from an identification problem: cultural groups most likely differ in both objective achievements in different life domains as well as in…

  11. Dog Bridge, view of the deck of the bridge and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Dog Bridge, view of the deck of the bridge and rails looking from Linden Lane - National Park Seminary, Bounded by Capitol Beltway (I-495), Linden Lane, Woodstove Avenue, & Smith Drive, Silver Spring, Montgomery County, MD

  12. 198. SPOUT RUN ARCH BRIDGE AND SPOUT RUN WESTBOUND BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    198. SPOUT RUN ARCH BRIDGE AND SPOUT RUN WESTBOUND BRIDGE FROM POTOMAC RIVER LOOKING SOUTHWEST. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

  13. 4. VIEW OF SILVER BRIDGE (ST. MARY'S BRIDGE), CARRYING COUNTY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF SILVER BRIDGE (ST. MARY'S BRIDGE), CARRYING COUNTY ROAD OVER SOURIS RIVER NEAR SOUTH END OF REFUGE, LOOKING NORTHEAST - Upper Souris National Wildlife Refuge Dams, Souris River Basin, Foxholm, Surrey (England), ND

  14. Shoreham Railroad Bridge, Title Sheet Shoreham Railroad Bridge, Former ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Shoreham Railroad Bridge, Title Sheet - Shoreham Railroad Bridge, Former Addison County Railroad (later, Rutland Railroad, Addison Branch), spanning Lemon Fair River above Richville Pond, west of East Shoreham Road, Shoreham, Addison County, VT

  15. Bridge Types: Suspension Bridge Spans, Section AA; Cantilever Truss Spans, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bridge Types: Suspension Bridge Spans, Section A-A; Cantilever Truss Spans, Section B-B; Through Truss Spans, Section C-C; Deck Truss Spans, Section D-D - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  16. BUILDING "BRIDGES" WITH QUALITY ASSURANCE

    EPA Science Inventory

    The papr describes how, rather than building "bridges" across centuries, quality assurance (QA) personnel have the opportunity to build bridges across technical disciplines, between public and private organizations, and between different QA groups. As reviewers and auditors of a...

  17. Bridging Disciplinary Boundaries

    ERIC Educational Resources Information Center

    Mei, Linda

    2009-01-01

    Interdisciplinary education promotes the unity of knowledge by bridging the cultural divide between the social constructs of disciplines and encourages the development of knowledge to enhance society. As an inquiry-based and relevant approach that expands and advances knowledge, interdisciplinary education facilitates creativity and flexibility,…

  18. Bridging the Gaps.

    ERIC Educational Resources Information Center

    Netzer, Greg

    1995-01-01

    Discusses a model water quality monitoring project, Project Bridge, established to train minority girls about to enter eighth grade in scientific procedures followed by hands-on experimentation. Students spent a week monitoring water in an urban stream and analyzing results. (LZ)

  19. Bridging the Gap?

    ERIC Educational Resources Information Center

    Salter, Colin

    2009-01-01

    The political context of the conversion of the Historic Tramway Bridge, adjacent to Sandon Point in Bulli (NSW, Australia), and how this was exploited to serve predetermined ends, illustrates that technologies can be designed to have particular social (and political) effects. Through reflection on this relatively small engineering project, this…

  20. Building a Straw Bridge

    ERIC Educational Resources Information Center

    Teaching Science, 2015

    2015-01-01

    This project is for a team of students (groups of two or three are ideal) to design and construct a model of a single-span bridge, using plastic drinking straws as the building material. All steps of the design, construction, testing and critiquing stages should be recorded by students in a journal. Students may like to include labelled diagrams,…

  1. Quantum Bidding in Bridge

    NASA Astrophysics Data System (ADS)

    Muhammad, Sadiq; Tavakoli, Armin; Kurant, Maciej; Pawłowski, Marcin; Żukowski, Marek; Bourennane, Mohamed

    2014-04-01

    Quantum methods allow us to reduce communication complexity of some computational tasks, with several separated partners, beyond classical constraints. Nevertheless, experimental demonstrations of this have thus far been limited to some abstract problems, far away from real-life tasks. We show here, and demonstrate experimentally, that the power of reduction of communication complexity can be harnessed to gain an advantage in a famous, immensely popular, card game—bridge. The essence of a winning strategy in bridge is efficient communication between the partners. The rules of the game allow only a specific form of communication, of very low complexity (effectively, one has strong limitations on the number of exchanged bits). Surprisingly, our quantum technique does not violate the existing rules of the game (as there is no increase in information flow). We show that our quantum bridge auction corresponds to a biased nonlocal Clauser-Horne-Shimony-Holt game, which is equivalent to a 2→1 quantum random access code. Thus, our experiment is also a realization of such protocols. However, this correspondence is not complete, which enables the bridge players to have efficient strategies regardless of the quality of their detectors.

  2. The Bridge to Somewhere

    ERIC Educational Resources Information Center

    Lum, Lydia

    2009-01-01

    Since its inception in 2000, Pan-Asian American Community House's (PAACH's) education mission has bridged Asian-American studies to student life. PAACH initiatives have helped spread Asian-American diaspora to thousands of students at the University of Pennsylvania. They have also helped students determine for themselves what it means to be a…

  3. Bridging the Gap.

    ERIC Educational Resources Information Center

    Kroto, Joseph J.

    1988-01-01

    Describes interdisciplinary activities with real-world applications ranging from science to mathematics to technology. Cites the study and construction of model bridges as a way for students to learn about engineering concepts and some of their relationships. States that the exercise enhanced teacher cooperation between the different fields. (RT)

  4. Virtual Bridge Design

    ERIC Educational Resources Information Center

    Bisogno, Janet; JeanPierre, Bobby

    2008-01-01

    The West Point Bridge Design (WPBD) building project engages students in project-based learning by giving them a real-life problem to solve. By using technology, students are able to become involved in solving problems that they normally would not encounter. Involvement with interactive websites, such as WPBD, assists students in using…

  5. Bridging the Abyss

    ERIC Educational Resources Information Center

    Olcott, Marianina

    2007-01-01

    This paper seeks to explain the epistemological bases for the two cultures and to show why this disciplinary divide continues to plague American academic culture. Next, we discuss strategies for bridging the two cultures through general education curricula which promote mutual understanding of the two cultures while educating students in basic…

  6. Building Migratory Bridges

    ERIC Educational Resources Information Center

    Roy, Michael; Doss, Laurie K.

    2007-01-01

    The Building Migratory Bridges (BOMB) program--a collaboration between the Marvel wood School and Audubon Sharon in Connecticut and Conservation Research Education Action (CR EA), a U.S. not-for-profit in Panama--uses nontropical migratory bird research in the United States and Panama to demonstrate how negative environmental impacts in one…

  7. The Bridges Program.

    ERIC Educational Resources Information Center

    Bohnen, Elizabeth; Klie, Judy

    This report describes BRIDGES, an employment equity special measures training program developed by the City of Toronto (Ontario, Canada). It was designed to help women employees move from their traditional jobs into trades, technical or operation (TTO) jobs within their own organization. The program is a combination of classroom sessions, shop…

  8. Bridge the Gap.

    ERIC Educational Resources Information Center

    Klein, Mel; Cufaude, Jeffrey B.

    1989-01-01

    This document consists of two paired articles: the first, "Preparing Faculty Out of Class Experiences," by Mel Klein, and the second, "Help Advisers Be More Than Ghost Signatures," by Jeffrey B. Calfaude. Each article shares insights on how faculty advisers "bridge the gap" between students and faculty. When faculty members are asked to advise…

  9. Bridge-safety evaluation using ultrasonic stress measurement

    NASA Astrophysics Data System (ADS)

    Clark, Al V.; Lozev, Margarit G.; Fuchs, P. A.

    1996-11-01

    Fracture mechanics can be used to evaluate the consequence of having a crack in a bridge structure. To do so requires that the stress state near the crack be known including the contribution of residual and fabrication stresses. In general these must be measured. Stress causes a small but measurable change in the speed of sound in many materials. Hence measurement of velocity in a bridge provides a means to determine all the components of stress. This concept has been demonstrated in laboratory situations by various researchers. Here we report results from field tests on actual bridges. The stress in flange and web regions of two bridges was measured with ultrasonics. In the first bridge we determined the residual stress in the girders. The second bridge was an integral backwall bridge with no expansion joints. It had been instrumented at time of construction. Strain gage readings indicated compressive stresses near yield. Ultrasonic measurements showed the bridge to be safe. Subsequent replacement of suspect electronics in the monitoring instrumentation verified the ultrasonic results to be safe.

  10. The Contributions of Phonological Awareness and Letter-Name Knowledge to Letter-Sound Acquisition--A Cross-Classified Multilevel Model Approach

    ERIC Educational Resources Information Center

    Kim, Young-Suk; Petscher, Yaacov; Foorman, Barbara R.; Zhou, Chengfu

    2010-01-01

    In the present study, we investigated critical factors in letter-sound acquisition (i.e., letter-name knowledge and phonological awareness) with data from 653 English-speaking kindergartners in the beginning of the year. We examined (a) the contribution of phonological awareness to facilitating letter-sound acquisition from letter names and (b)…

  11. Application of Economic Indicators to Asses the Bridges of Rehablitation

    NASA Astrophysics Data System (ADS)

    Pitoňák, Martin; Valuch, Milan

    2015-05-01

    The aim of this paper is to point out the advantage of Cost Benefit Analysis (CBA) and its economic indicators to assess a rehabilitation of bridges. The paper includes short example of assessment of the project economic efficiency in which economic indicators are applied in order to evaluate of two technology project variants of bridge object rehabilitation. It quantifies and compares the economic results of alternative 1 with the monolithic prestress construction and alternative 2, with the composite steel - concrete bridge. The contribution reflects the current practice of economic analysis recommended by the Ministry of Transport, Construction and Regional Development.

  12. Lifestyle-Related Factors Contributing to Decline in Knee Extension Strength among Elderly Women: A Cross-Sectional and Longitudinal Cohort Study

    PubMed Central

    Kojima, Narumi; Kim, Miji; Saito, Kyoko; Yoshida, Hideyo; Yoshida, Yuko; Hirano, Hirohiko; Obuchi, Shuichi; Shimada, Hiroyuki; Suzuki, Takao; Kim, Hunkyung

    2015-01-01

    This cross-sectional and 4-year longitudinal cohort study aimed to clarify how various lifestyle-related variables affect knee extension strength in elderly Japanese women. The participants were community-dwelling women (n = 575) living in the Itabashi Ward of Tokyo, Japan aged 75–85 years at baseline (in 2008) who returned for a follow-up examination 4 years later (in 2012). Maximum isometric knee extension strength in the dominant leg was measured during comprehensive medical check-ups at baseline and follow-up. Interviews with participants included questions on their history of 11 diseases and lifestyle-related factors such as physical activity as well as dietary, smoking, and drinking habits. Cross-sectional and longitudinal analyses yielded inconsistent results regarding the associations between lifestyle-related factors and knee extension strength. While going out more frequently and regular physical exercise positively affected baseline knee extension strength, they did not affect knee extension strength in the longitudinal analysis. The longitudinal analysis revealed that more frequent intake of soy products or green and yellow vegetables at baseline decreased age-related knee extension strength decline. The inconsistent results from the cross-sectional and longitudinal analyses indicate that conducting both types of analyses is crucial for researching this type of subject. The present study demonstrates that the age-related decline in muscle strength is lower in those who frequently eat soy products or green and yellow vegetables. Thus, recommending higher intake of soy products, and green and yellow vegetables for the elderly might help maintain their muscle health. PMID:26177292

  13. Chord Splicing & Joining Detail; Chord & CrossBracing Joint Details; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Chord Splicing & Joining Detail; Chord & Cross-Bracing Joint Details; Cross Bracing Center Joint Detail; Chord & Diagonal Joint Detail - Vermont Covered Bridge, Highland Park, spanning Kokomo Creek at West end of Deffenbaugh Street (moved to), Kokomo, Howard County, IN

  14. Dynamics of polymeric brushes: End exchange and bridging kinetics

    NASA Astrophysics Data System (ADS)

    Johner, A.; Joanny, J. F.

    1993-01-01

    We study some dynamical aspects of grafted polymer layers in a solvent. The structure of the brush is described in a θ solvent by the self-consistent mean field theory and in a good solvent using scaling laws. The Rouse-Zimm model including hydrodynamic interactions is used for the dynamic properties. A given chain end explores the entire thickness of a free grafted layer in a time Te proportional to the cube of the thickness. The exploration time is much larger than the Rouse time that characterizes the relaxation of the fluctuations of the chains conformations. In a θ-solvent we give a detailed study of the relaxation of the density of a few labeled chain ends towards its equilibrium value. The bridging kinetics between a grafting plate and a plate adsorbing the free ends is also discussed. When adsorption proceeds, an exclusion zone grows in the vicinity of the adsorbing plate. To cross the exclusion zone and adsorb, a chain end must overcome an energy barrier. The typical adsorption time is the first passage time through this barrier. Except in the very late stages where the fraction of chains η forming bridges saturates at its equilibrium value, the energy barrier against adsorption increases as a power law of η and the bridging fraction increases very slowly (logarithmically) with time. Both weak bridging where only a small fraction of chains form bridges and total bridging where all the chains form bridges are studied.

  15. Electrical Actuation Technology Bridging

    NASA Technical Reports Server (NTRS)

    Hammond, Monica (Compiler); Sharkey, John (Compiler)

    1993-01-01

    This document contains the proceedings of the NASA Electrical Actuation Technology Bridging (ELA-TB) Workshop held in Huntsville, Alabama, September 29-October 1, 1992. The workshop was sponsored by the NASA Office of Space Systems Development and Marshall Space Flight Center (MSFC). The workshop addressed key technologies bridging the entire field of electrical actuation including systems methodology, control electronics, power source systems, reliability, maintainability, and vehicle health management with special emphasis on thrust vector control (TVC) applications on NASA launch vehicles. Speakers were drawn primarily from industry with participation from universities and government. In addition, prototype hardware demonstrations were held at the MSFC Propulsion Laboratory each afternoon. Splinter sessions held on the final day afforded the opportunity to discuss key issues and to provide overall recommendations. Presentations are included in this document.

  16. [Retention of adhesive bridges].

    PubMed

    Raes, F; De Boever, J

    1994-04-01

    Since the development of adhesive bridges in the early seventies, the retention and therefore the durability of these bridges has been tremendously improved. Conditioning of the non-precious metal by silanisation, careful acid etching of the enamel and the use of the appropriate composite resin are of prime importance. Furthermore, the meticulous preparation with enough interproximal embrace, occlusal rests, interocclusal clearance and cingulum stops is equally important. Including more teeth in the design does not necessarily lead to an improved retention. Besides the material and technical aspects, the whole clinical procedure needs much attention. The retention does not depend on one single factor, but on the precision of all the necessary clinical steps and on a well-defined selection of the material. In this way a five-year survival rate of close to 80% can be obtained. PMID:11830965

  17. Steel bridge retrofit evaluation

    NASA Astrophysics Data System (ADS)

    Prine, David W.

    1998-03-01

    The development of a retrofit design aimed at retarding or eliminating fatigue crack growth in a large bridge can be a very difficult and expensive procedure. Analytical techniques frequently do not provide sufficient accuracy when applied to complex structural details. The Infrastructure Technology Institute (ITI) of Northwestern University, under contract to the California Department of Transportation (Caltrans), recently applied experimental state-of-the-art NDE technology to the Interstate 80 bridge over the Sacramento River near Sacramento, California (Bryte Bend). Acoustic emission monitoring was applied in conjunction with strain gage monitoring to aid in characterizing the retrofits' effect on existing active fatigue cracks. The combined test results clearly showed that one retrofit design was superior to the other.

  18. Nematic liquid crystal bridges

    NASA Astrophysics Data System (ADS)

    Doss, Susannah; Ellis, Perry; Vallamkondu, Jayalakshmi; Danemiller, Edward; Vernon, Mark; Fernandez-Nieves, Alberto

    We study the effects of confining a nematic liquid crystal between two parallel glass plates with homeotropic boundary conditions for the director at all bounding surfaces. We find that the free surface of the nematic bridge is a surface of constant mean curvature. In addition, by changing the distance between the plates and the contact angle with the glass plates, we transition between loops and hedgehogs that can be either radial or hyperbolic.

  19. Communication through molecular bridges: different bridge orbital trends result in common property trends.

    PubMed

    Proppe, Jonny; Herrmann, Carmen

    2015-02-01

    Common trends in communication through molecular bridges are ubiquitous in chemistry, such as the frequently observed exponential decay of conductance/electron transport and of exchange spin coupling with increasing bridge length, or the increased communication through a bridge upon closing a diarylethene photoswitch. For antiferromagnetically coupled diradicals in which two equivalent spin centers are connected by a closed-shell bridge, the molecular orbitals (MOs) whose energy splitting dominates the coupling strength are similar in shape to the MOs of the dithiolated bridges, which in turn can be used to rationalize conductance. Therefore, it appears reasonable to expect the observed common property trends to result from common orbital trends. We illustrate based on a set of model compounds that this assumption is not true, and that common property trends result from either different pairs of orbitals being involved, or from orbital energies not being the dominant contribution to property trends. For substituent effects, an effective modification of the π system can make a comparison difficult. PMID:25382464

  20. [Retention of adhesive bridges].

    PubMed

    Raes, F; De Boever, J

    1990-01-01

    Since the development of adhesive bridges in the early seventies, the retention and therefore the durability of these bridges has been tremendously improved. To ensure an adequate retention over a number of years different factors have to be considered. Conditioning of the non-precious metal by silanisation, careful acid etching of the enamel and the use of the appropriate composite resin (Panavia Ex) are of prime importance. Furthermore, the meticulous preparation with enough interproximal embrace, occlusal rets, interocclusal clearance of 0.4 mm and cingulum stops is equally important. Care should be taken not to remove all the enamel in the cervical region in preparing a mini chamfer. Including more teeth in the design does not necessarily lead to an improved retention. Teeth with a different mobility should not be included in the same bridge. Besides the material and technical aspects, the whole clinical procedure needs much attention. Only an exact impression, a precise model and a reliable casting technique will provide a metal frame with an optimal marginal adaptation and a close fit. The retention does not depend on one single factor but on the precision of all the necessary clinical steps and on a well-defined selection of the material. In this way a five-year survival rate of close to 90% can be obtained. PMID:2077574

  1. Effects of bridge construction on songbirds and small mammals at Blennerhassett Island, Ohio River, USA.

    PubMed

    Vance, Joshua A; Angus, Norse B; Anderson, James T

    2013-09-01

    Construction of man-made objects such as roads and bridges may have impacts on wildlife depending on species or location. We investigated songbirds and small mammals along the Ohio River, WV, USA at a new bridge both before and after construction and at a bridge crossing that was present throughout the study. Comparisons were made at each site over three time periods (1985-1987 [Phase I] and 1998-2000 [Phase II] [pre-construction], 2007-2009 [Phase III] [post-construction]) and at three distances (0, 100, 300 m) from the bridge or proposed bridge location. Overall, 70 songbirds and 10 small mammals were detected during the study. Cliff swallows (Petrochelidon pyrrhonota) and rock pigeons (Columba livia) showed high affinity for bridges (P < 0.05). Combined small mammal abundances increased between Phases I and II (P < 0.05), but did not differ between Phases II and III (P > 0.05). Species richness and diversity for songbirds and small mammals did not differ before and after bridge construction (P > 0.05). We found that most species sampled did not respond to the bridge crossing, and believe that the bridge is not causing any measurable negative density impacts to the species we investigated. The new bridge does provide habitat for exotic rock pigeons that are adjusted to man-made structures for nesting. PMID:23435850

  2. Induction of G protein-coupled receptor kinases 2 and 3 contributes to the cross-talk between mu and ORL1 receptors following prolonged agonist exposure.

    PubMed

    Thakker, D R; Standifer, K M

    2002-11-01

    The molecular mechanism(s) underlying cross-tolerance between mu and opioid receptor-like 1 (ORL1) receptor agonists were investigated using two human neuroblastoma cell lines endogenously expressing these receptors and G protein-coupled receptor kinases (GRKs). Prolonged (24 h) activation of the mu receptor desensitized both mu and ORL1 receptor-mediated inhibition of forskolin-stimulated cAMP accumulation and upregulated GRK2 levels in SH-SY5Y and BE(2)-C cells. Prolonged ORL1 activation increased GRK2 levels and desensitized both receptors in SH-SY5Y cells. Upregulation of GRK2 correlated with increases in levels of transcription factors Sp1 or AP-2. PD98059, an upstream inhibitor of extracellular signal-regulated kinases 1 and 2 (ERK1/2), reversed all these events. Pretreatment with orphanin FQ/nociceptin (OFQ/N) also upregulated GRK3 levels in both cell lines, and desensitized both receptors in BE(2)-C cells. Protein kinase C (PKC), but not ERK1/2, inhibition blocked OFQ/N-mediated GRK3 induction and mu and ORL1 receptor desensitization in BE(2)-C cells. Antisense DNA treatment confirmed the involvement of GRK2/3 in mu and ORL1 desensitization. Here, we demonstrate for the first time a role for ERK1/2-mediated GRK2 induction in the development of tolerance to mu agonists, as well as cross-tolerance to OFQ/N. We also demonstrate that chronic OFQ/N-mediated desensitization of ORL1 and mu receptors occurs via cell-specific pathways, involving ERK1/2-dependent GRK2, or PKC-dependent and ERK1/2-independent GRK3 induction. PMID:12423667

  3. 19. BLUEPRINT, RR BRIDGE MISSISSIPPI, CLAY CO., WAVERLY 1.5 mi. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. BLUEPRINT, RR BRIDGE MISSISSIPPI, CLAY CO., WAVERLY 1.5 mi. S of Ms. 50 Map of Tombigbee River at Waverly, 'Proposed Crossing.' 12 May 1888. Credt: Columbus & Greenville, RR, Columbus, Ms. DWG S-3-343. Sarcone Photography, ColumbuS, Ms. Sept 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  4. Myofilament dysfunction contributes to impaired myocardial contraction in the infarct border zone

    PubMed Central

    Shimkunas, Rafael; Makwana, Om; Spaulding, Kimberly; Bazargan, Mona; Khazalpour, Michael; Takaba, Kiyoaki; Soleimani, Mehrdad; Myagmar, Bat-Erdene; Lovett, David H.; Simpson, Paul C.; Ratcliffe, Mark B.

    2014-01-01

    After myocardial infarction, a poorly contracting nonischemic border zone forms adjacent to the infarct. The cause of border zone dysfunction is unclear. The goal of this study was to determine the myofilament mechanisms involved in postinfarction border zone dysfunction. Two weeks after anteroapical infarction of sheep hearts, we studied in vitro isometric and isotonic contractions of demembranated myocardium from the infarct border zone and a zone remote from the infarct. Maximal force development (Fmax) of the border zone myocardium was reduced by 31 ± 2% versus the remote zone myocardium (n = 6/group, P < 0.0001). Decreased border zone Fmax was not due to a reduced content of contractile material, as assessed histologically, and from myosin content. Furthermore, decreased border zone Fmax did not involve altered cross-bridge kinetics, as assessed by muscle shortening velocity and force development kinetics. Decreased border zone Fmax was associated with decreased cross-bridge formation, as assessed from muscle stiffness in the absence of ATP where cross-bridge formation should be maximized (rigor stiffness was reduced 34 ± 6%, n = 5, P = 0.011 vs. the remote zone). Furthermore, the border zone myocardium had significantly reduced phosphorylation of myosin essential light chain (ELC; 41 ± 10%, n = 4, P < 0.05). However, for animals treated with doxycycline, an inhibitor of matrix metalloproteinases, rigor stiffness and ELC phosphorylation were not reduced in the border zone myocardium, suggesting that doxycycline had a protective effect. In conclusion, myofilament dysfunction contributes to postinfarction border zone dysfunction, myofilament dysfunction involves impaired cross-bridge formation and decreased ELC phosphorylation, and matrix metalloproteinase inhibition may be beneficial for limiting postinfarct border zone dysfunction. PMID:25128171

  5. Acquisition and Analysis of Dynamic Responses of a Historic Pedestrian Bridge using Video Image Processing

    NASA Astrophysics Data System (ADS)

    O'Byrne, Michael; Ghosh, Bidisha; Schoefs, Franck; O'Donnell, Deirdre; Wright, Robert; Pakrashi, Vikram

    2015-07-01

    Video based tracking is capable of analysing bridge vibrations that are characterised by large amplitudes and low frequencies. This paper presents the use of video images and associated image processing techniques to obtain the dynamic response of a pedestrian suspension bridge in Cork, Ireland. This historic structure is one of the four suspension bridges in Ireland and is notable for its dynamic nature. A video camera is mounted on the river-bank and the dynamic responses of the bridge have been measured from the video images. The dynamic response is assessed without the need of a reflector on the bridge and in the presence of various forms of luminous complexities in the video image scenes. Vertical deformations of the bridge were measured in this regard. The video image tracking for the measurement of dynamic responses of the bridge were based on correlating patches in time-lagged scenes in video images and utilisinga zero mean normalised cross correlation (ZNCC) metric. The bridge was excited by designed pedestrian movement and by individual cyclists traversing the bridge. The time series data of dynamic displacement responses of the bridge were analysedto obtain the frequency domain response. Frequencies obtained from video analysis were checked against accelerometer data from the bridge obtained while carrying out the same set of experiments used for video image based recognition.

  6. Can integrated watershed management contribute to improvement of public health? A cross-sectional study from hilly tribal villages in India.

    PubMed

    Nerkar, Sandeep S; Pathak, Ashish; Lundborg, Cecilia Stålsby; Tamhankar, Ashok J

    2015-03-01

    Tribal people living in hilly areas suffer from water scarcity in many parts of the world, including India. Water scarcity adversely impacts all aspects of life, including public health. Implementation of an Integrated Watershed Management Programme (IWMP) can help solve the problems arising out of water scarcity in such areas. However, the knowledge about and views of the water scarcity sufferers on the public health implications of IWMP have not been well documented. This cross-sectional study was performed in six purposively selected tribal villages located in Maharashtra, India. In three of the villages IWMP had been implemented (IWMV), but not in the other three (NWMV). The head of each household in all villages was interviewed using a questionnaire covering various public health aspects relevant to the villages. A total of 286/313 (92%) households participated in the study. Compared to NWMV, respondents in IWMV experienced significantly lesser prolonged water scarcity (OR=0.39), had greater number of toilets (OR=6.95), cultivated more variety of crops (OR=2.61), had lower migration (OR=0.59), higher number of girls continuing education (OR=3.04) and better utilized modern healthcare facilities in the antenatal, natal and postnatal period (OR=3.75, 2.57, 4.88 respectively). Thus, tribal people in IWMP-implemented villages reported advantages in many aspects of public health. PMID:25734794

  7. Can Integrated Watershed Management Contribute to Improvement of Public Health? A Cross-Sectional Study from Hilly Tribal Villages in India

    PubMed Central

    Nerkar, Sandeep S.; Pathak, Ashish; Lundborg, Cecilia Stålsby; Tamhankar, Ashok J.

    2015-01-01

    Tribal people living in hilly areas suffer from water scarcity in many parts of the world, including India. Water scarcity adversely impacts all aspects of life, including public health. Implementation of an Integrated Watershed Management Programme (IWMP) can help solve the problems arising out of water scarcity in such areas. However, the knowledge about and views of the water scarcity sufferers on the public health implications of IWMP have not been well documented. This cross-sectional study was performed in six purposively selected tribal villages located in Maharashtra, India. In three of the villages IWMP had been implemented (IWMV), but not in the other three (NWMV). The head of each household in all villages was interviewed using a questionnaire covering various public health aspects relevant to the villages. A total of 286/313 (92%) households participated in the study. Compared to NWMV, respondents in IWMV experienced significantly lesser prolonged water scarcity (OR = 0.39), had greater number of toilets (OR = 6.95), cultivated more variety of crops (OR = 2.61), had lower migration (OR = 0.59), higher number of girls continuing education (OR = 3.04) and better utilized modern healthcare facilities in the antenatal, natal and postnatal period (OR = 3.75, 2.57, 4.88 respectively). Thus, tribal people in IWMP-implemented villages reported advantages in many aspects of public health. PMID:25734794

  8. Bridging Student Leadership Assessment across a Three-Institution Consortium

    ERIC Educational Resources Information Center

    Ostrom-Blonigen, Jean; Bornsen, Susan E.; Larson-Casselton, Cindy; Erickson, Sheri L.

    2010-01-01

    Throughout the nation, training students for leadership roles is a primary cross-disciplinary bridge from coursework to career or from service learning to community service. Student leadership training has been linked to communication traits of goal setting, decision making, conflict resolution, concern for community, and increased understanding…

  9. The active-bridge oscillator

    SciTech Connect

    Wessendorf, K.O.

    1998-07-01

    This paper describes the Active-Bridge Oscillator (ABO), a new concept in high-stability oscillator design. The ABO is ab ridge-type oscillator design that is easly to design and overcomes many of the operational and design difficulties associated with standard bridge oscillator designs. The ABO will oscillate with a very stable output amplitude over a wide range of operating conditions without the use of an automatic-level-control (ALC). A standard bridge oscillator design requires an ALC to maintain the desired amplitude of oscillation. for this and other reasons, bridge oscilaltors are not used in mainstream designs. Bridge oscillators are generally relegated to relatively low-volume, high-performance applications. The Colpitts and Pierce designs are the most popular oscillators but are typically less stable than a bridge-type oscillator.

  10. Do antenatal care visits always contribute to facility-based delivery in Tanzania? A study of repeated cross-sectional data.

    PubMed

    Choe, Seung-Ah; Kim, Jinseob; Kim, Saerom; Park, Yukyung; Kullaya, Siril Michael; Kim, Chang-yup

    2016-04-01

    There is a known high disparity in access to perinatal care services between urban and rural areas in Tanzania. This study analysed repeated cross-sectional (RCS) data from Tanzania to explore the relationship between antenatal care (ANC) visits, facility-based delivery and the reasons for home births in women who had made ANC visits. We used data from RCS Demographic and Health Surveys spanning 20 years and a cluster sample of 30 830 women from ∼52 districts of Tanzania. The relationship between the number of ANC visits (up to four) and facility delivery in the latest pregnancy was explored. Regional changes in facility delivery and related variables over time in urban and rural areas were analysed using linear mixed models. To explore the disconnect between ANC visits and facility deliveries, reasons for home delivery were analysed. In the analytic model with other regional-level covariates, a higher proportion of ANC (>2-4 visits) and exposure to media related to an increased facility delivery rate in urban areas. For rural women, there was no significant relationship between the number of visits and facility delivery rate. According to the fifth wave result (2009-10), the most frequent reason for home delivery was 'physical distance to facility', and a significantly higher proportion of rural women reported that they were 'not allowed to deliver in facility'. The disconnect between ANC visits and facility delivery in rural areas may be attributable to physical, cultural or familial barriers, and quality of care in health facilities. This suggests that improving access to ANC may not be enough to motivate facility-based delivery, especially in rural areas. PMID:26049085

  11. Altered expression of topoisomerase IIα contributes to cross-resistant to etoposide K562/MX2 cell line by aberrant methylation

    PubMed Central

    Asano, T; Nakamura, K; Fujii, H; Horichi, N; Ohmori, T; Hasegawa, K; Isoe, T; Adachi, M; Otake, N; Fukunaga, Y

    2005-01-01

    KRN 8602 (MX2) is a novel morpholino anthracycline derivative having the chemical structure 3′-deamino-3′-morpholino-13-deoxo-10-hydroxycarminomycin hydrochloride. To investigate the mechanisms of resistance to MX2, we established an MX2-resistant phenotype (K562/MX2) of the human myelogeneous leukaemia cell line (K562/P), by continuously exposing a suspension culture to increasing concentrations of MX2. K562/MX2 cells were more resistant to MX2 than the parent cells, and also showed cross-resistance to etoposide and doxorubicin. Topoisomerase (Topo) IIα protein levels in K562/MX2 cells were lower of those in K562/P cells on immunoblot analysis and decreased expression of Topo IIα mRNA was seen in K562/MX2 cells. Topoisomerase II catalytic activity was also reduced in the nuclear extracts from K562/MX2 cells when compared with K562/P cells. Aberrant methylated CpG of Topo IIα gene was observed in K562/MX2 cells when compared with the parent line on methylation-specific restriction enzyme analysis. To overcome the drug resistance to MX2 and etoposide, we investigated treatment with 5-Aza-2′-deoxycytidine (5AZ), which is a demethylating agent, in K562/MX2 cells. 5-Aza-2′-deoxycytidine treatment increased Topo IIα mRNA expression in K562/MX2 cells, but not in K562/P cells, and increased the cytotoxicity of MX2 and etoposide. Methylated CpG was decreased in K562/MX2 cells after 5AZ treatment. We concluded that the mechanism of drug resistance to MX2 and etoposide in K562/MX2 cells might be the combination of decreased expression of Topo IIα gene and increased methylation, and that 5AZ could prove to be a novel treatment for etoposide-resistant cell lines, such as K562/MX2. PMID:15798770

  12. Do antenatal care visits always contribute to facility-based delivery in Tanzania? A study of repeated cross-sectional data

    PubMed Central

    Choe, Seung-Ah; Kim, Jinseob; Kim, Saerom; Park, Yukyung; Kullaya, Siril Michael; Kim, Chang-yup

    2016-01-01

    There is a known high disparity in access to perinatal care services between urban and rural areas in Tanzania. This study analysed repeated cross-sectional (RCS) data from Tanzania to explore the relationship between antenatal care (ANC) visits, facility-based delivery and the reasons for home births in women who had made ANC visits. We used data from RCS Demographic and Health Surveys spanning 20 years and a cluster sample of 30 830 women from ∼52 districts of Tanzania. The relationship between the number of ANC visits (up to four) and facility delivery in the latest pregnancy was explored. Regional changes in facility delivery and related variables over time in urban and rural areas were analysed using linear mixed models. To explore the disconnect between ANC visits and facility deliveries, reasons for home delivery were analysed. In the analytic model with other regional-level covariates, a higher proportion of ANC (>2–4 visits) and exposure to media related to an increased facility delivery rate in urban areas. For rural women, there was no significant relationship between the number of visits and facility delivery rate. According to the fifth wave result (2009–10), the most frequent reason for home delivery was ‘physical distance to facility’, and a significantly higher proportion of rural women reported that they were ‘not allowed to deliver in facility’. The disconnect between ANC visits and facility delivery in rural areas may be attributable to physical, cultural or familial barriers, and quality of care in health facilities. This suggests that improving access to ANC may not be enough to motivate facility-based delivery, especially in rural areas. PMID:26049085

  13. Bridging the Gap.

    PubMed

    Webb, Michele

    2016-01-01

    The view from the top of Hoover Dam looking south over the Colorado River was breathtaking! My friend and I stood there in silence, taking it all in. I had visited Hoover Dam on many occasions, but this visit was the first time I had seen the arch bridge that carries US Route 93 over the river and joins Nevada and Arizona states. It was a beautiful day, the temperature was perfect, and there was a slight breeze coming from Lake Mead behind us as we took in the view. PMID:27556855

  14. Bridging the Gap: Solving Spatial Means-Ends Relations in a Locomotor Task

    ERIC Educational Resources Information Center

    Berger, Sarah E.; Adolph, Karen E.; Kavookjian, Alisan E.

    2010-01-01

    Using a means-means-ends problem-solving task, this study examined whether 16-month-old walking infants (N = 28) took into account the width of a bridge as a means for crossing a precipice and the location of a handrail as a means for augmenting balance on a narrow bridge. Infants were encouraged to cross from one platform to another over narrow…

  15. Experimental Analysis of Stiffness of the Riveted Steel Railway Bridge Deck Members' Joints

    NASA Astrophysics Data System (ADS)

    Gocál, Jozef; Hlinka, Richard; Jošt, Jozef; Bahleda, František

    2014-12-01

    The paper deals with the real behaviour of the riveted steel railway bridge deck members' connections with respect to their bending stiffness. Attention is paid to the stringer-to-cross beam connection as well as the cross beam-to-main girder connection. The stiffness of the two connections is investigated on the basis of evaluation of the experimentally determined stress response of the observed structural members to the actual traffic load on an existing railway bridge.

  16. Some risk factors for reproductive failures and contribution of Toxoplasma gondii infection in sheep and goats of Central Ethiopia: a cross-sectional study.

    PubMed

    Gebremedhin, Endrias Zewdu; Agonafir, Abebe; Tessema, Tesfaye Sisay; Tilahun, Getachew; Medhin, Girmay; Vitale, Maria; Di Marco, Vincenzo

    2013-12-01

    Reproductive failure has a negative impact on animal production, health and welfare and ultimately rural economies. In Ethiopia, the factors affecting small ruminant reproductive efficiency are inadequately investigated. A cross-sectional survey was done from November, 2010 to May, 2011 to investigate risk factors of reproductive failures including Toxoplasma gondii infection. Analysis of 1372 sera (787 sheep and 585 goats) from 409 flocks using ELISA showed high flock (59.7%) and animal (31.8%) level T. gondii seroprevalence. An overall 24.9% (341/1372) annual abortion rate (19.6% in sheep and 32.0% in goats) was recorded. Animal level T. gondii seroprevalence was significantly associated with abortion in Ambo and Ada'a-Liben districts (Odds ratio [OR] = 2.31, 95% confidence interval [CI]: 1.42, 3.76; P = 0.001). Questionnaire survey on 199 households of Ambo, Ada'a-Liben and Fentale districts revealed high flock level abortion (57.5%), still birth (28.9%) and neonatal losses (47.9%), which are significantly different between study districts (P<0.001). Multivariable logistic regression model showed that species (goat), large flock size, pastoral and agro-pastoral production systems, drinking water from river and stagnant water bodies, grazing/browsing in plain land and extensive management were significant predictors of flock level reproductive failures. In the final Zero inflated Poisson regression model number of abortions was significantly higher in goat than in sheep flocks (Incidence risk ratio [IRR] = 1.42, 95% CI: 1.08, 1.87; P = 0.012). It is also significantly higher in pastoral (IRR = 1.81, 95% CI: 1.16, 2.83; P = 0.008) and agro-pastoral production systems (IRR = 1.94, 95% CI: 1.32, 2.86; P = 0.001) than in sedentary production system. Prevention of toxoplasmosis, improved husbandry practices and further epidemiological studies to identify causes of reproductive failures are recommended. PMID:24011595

  17. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  18. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  19. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  20. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  1. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  2. 25. White Plains Road Bridge in foreground; Unionport Road Bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. White Plains Road Bridge in foreground; Unionport Road Bridge in background. Van Nest, Bronx Co., NY. Sec. 4207, MP 12.75./78. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  3. 5. North side of throughtruss bridge over railroad tracks (bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. North side of through-truss bridge over railroad tracks (bridge #U182512605). View to southwest. - South Omaha Union Stock Yards, "O" Street Viaduct, "O" Street Spanning Hog Pens; South Omaha Terminal Railway Company Tracks & Union Pacific Railroad Tracks, Omaha, Douglas County, NE

  4. 16. Little Hell Gate Bridge with Big Hell Gate Bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Little Hell Gate Bridge with Big Hell Gate Bridge in background. Wards Island, New York Co., NY. Sec. 4207, MP 8.02. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  5. 20. Bronx Kill Bridge with Hell Gate Bridge in background. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Bronx Kill Bridge with Hell Gate Bridge in background. Randalls Island, New York Co., NY. Sec. 4207, MP 8.54. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  6. MR damping system on Dongting Lake cable-stayed bridge

    NASA Astrophysics Data System (ADS)

    Chen, Z. Q.; Wang, X. Y.; Ko, J. M.; Ni, Y. Q.; Spencer, Billie F., Jr.; Yang, G.

    2003-08-01

    The Dongting Lake Bridge is a cable-stayed bridge crossing the Dongting Lake where it meets the Yangtze River in southern central China. After this bridge was completed in 1999, its cables were observed to be sensitive to rain-wind-induced vibration, especially under adverse weather conditions of both rain and wind. To investigate the possibility of using MR damping systems to reduce cable vibration, a joint project between the Central South University of China and the Hong Kong Polytechnic University was conducted. Based on the promising research results, the bridge authority decided to install MR damping systems on the longest 156 stay cables. The installation started in July 2001 and finished in June 2002, making it the world's first application of MR dampers on cable-stayed bridge to suppress the rain-wind-induced cable vibration. As a visible and permanent aspect of bridge, the MR damping system must be aesthetically pleasing, reliable, durable, easy to maintain, as well as effective in vibration mitigation. Substantial work was done to meet these requirements. This paper describes the implementation of MR damping systems for cable vibration reduction.

  7. Railroad bridge instrumentation with fiber-optic sensors.

    PubMed

    Lee, W; Lee, J; Henderson, C; Taylor, H F; James, R; Lee, C E; Swenson, V; Atkins, R A; Gemeiner, W G

    1999-03-01

    Fiber-optic sensors were installed on fatigue-critical components in the superstructure of a railroad bridge to monitor dynamic strains induced by trains crossing the bridge as well as to detect the onset of cracks. Each fiber Fabry-Perot interferometer (FFPI) strain gage was adhesively bonded to a stainless-steel strip to facilitate all-weather installation on the steel bridge members by spot welding. FFPI strain sensors were also installed on a rail at an approach to the bridge. Electrical resistive strain gages were colocated with the fiber-optic sensors on the bridge for the purpose of performance verification. In addition to the strain gages, fiber-optic continuity sensors for crack detection were bonded to the structure at critical locations. A telemetry system for transmitting the data over telephone lines was also installed at the bridge site. Dynamic response of the fiber-optic strain sensors is comparable with that of the electrical gages, and their performance has not degraded in the year since the initial installation. PMID:18305719

  8. What contributes to a good quality of life in early dementia? awareness and the QoL-AD: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Self-report quality of life (QoL) measures for people with dementia are widely used as outcome measures in trials of dementia care interventions. Depressed mood, relationship quality and neuropsychiatric symptoms predict scores on these measures, whereas cognitive impairment and functional abilities typically do not. This study examines whether these self-reports are influenced by personality and by the person’s awareness of his/her impairments. A strong negative association between QoL and awareness of deficits would have implications for the validity of self-report in this context and for therapeutic interventions aiming to increase adjustment and coping. Methods Participants were 101 individuals with early‒stage dementia and their family carers participating in the Memory Impairment and Dementia Awareness (MIDAS) Study. QoL was assessed using the QoL-AD scale, and awareness was assessed in relation to memory, activities of daily living and social functioning. Self-concept, conscientiousness, quality of relationship and mood were assessed and a brief neuropsychological battery administered. Carers rated their own stress and well-being and reported on neuropsychiatric symptoms. A series of regression analyses predicting QoL-AD were carried out, identifying key variables in each domain of assessment to take forward to an overall model. Results Cognitive impairment was not related to QoL. The final model accounted for 57% of the variance in QoL-AD scores, with significant contributions from depressed mood, severity of irritability shown by the person with dementia, self-concept, quality of relationship (rated by the person with dementia) and male gender. The bivariate relationships of QoL-AD with awareness of memory function, awareness of functional abilities and conscientiousness were mediated by both depressed mood and self-concept. Conclusions This study reports the most comprehensive approach to evaluation of awareness to date. Most of the indices

  9. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Bridge-to-Bridge Act § 80.1007 Bridge-to-bridge radiotelephone installation. Use of the...

  10. Evaluation of mobile emissions contributions to Mexico City's emissions inventory using on-road and cross-road emission measurements and ambient data

    NASA Astrophysics Data System (ADS)

    Zavala, M.; Herndon, S. C.; Wood, E. C.; Onasch, T. B.; Knighton, W. B.; Kolb, C. E.; Molina, L. T.

    2009-03-01

    has been driven by reductions in CO levels rather than by NOx concentration changes, suggesting that the relative contribution of diesel vehicles to overall NOx levels has increased over time in the city. Despite the impressive increases in the size of the vehicle fleet between 2000 and 2006, the early morning ambient concentrations of CO and NOx have not increased accordingly, probably due to the reported low removal rates of older vehicles, which do not have emissions control technologies, and partially due to the much lower emissions from newer gasoline vehicles. This indicates that an emission-based air quality control strategy targeting large reductions of emissions from mobile sources should be directed towards a significant increase of the removal rate of older, highly-polluting, vehicles.

  11. Evaluation of mobile emissions contributions to Mexico City's emissions inventory using on-road and cross-road emission measurements and ambient data

    NASA Astrophysics Data System (ADS)

    Zavala, M.; Herndon, S. C.; Wood, E. C.; Onasch, T. B.; Knighton, W. B.; Marr, L. C.; Kolb, C. E.; Molina, L. T.

    2009-09-01

    levels rather than by NOx. These trends, together with the analysis of fuel sales and fleet size, suggest that the relative contribution of diesel vehicles to overall NOx levels has increased over time in the city. Despite the impressive increase in the size of the vehicle fleet between 2000 and 2006, the early morning ambient concentrations of CO and NOx have not increased accordingly, probably due to the reported low removal rates of older vehicles, which do not have emissions control technologies, and partially due to the much lower emissions from newer gasoline vehicles. This indicates that an emission-based air quality improvement strategy targeting large reductions of emissions from mobile sources should be directed towards a significant increase of the removal rate of older, highly-polluting, vehicles.

  12. Mathematics in Use: Suspension Bridges.

    ERIC Educational Resources Information Center

    Ginther, John L.

    1992-01-01

    Reviews the mathematics utilized in the design and construction of suspension bridges, in general, then illustrates these mathematical concepts by examining data associated with the Mackinac Bridge, which connects the two peninsulas of Michigan. Emphasizes the strong interest factor these gigantic structures have for students by attaching a sense…

  13. The violin bridge as filter.

    PubMed

    Bissinger, George

    2006-07-01

    The violin bridge filter role was investigated using modal and acoustic measurements on 12 quality-rated violins combined with systematic bridge rocking frequency f(rock) and wing mass decrements deltam on four bridges for two other violins. No isolated bridge resonances were observed; bridge motions were complex (including a "squat" mode near 0.8 kHz) except for low frequency rigid body pivot motions, all more or less resembling rocking motion at higher frequencies. A conspicuous broad peak near 2.3 kHz in bridge driving point mobility (labeled BH) was seen for good and bad violins. Similar structure was seen in averaged bridge, bridge feet, corpus mobilities and averaged radiativity. No correlation between violin quality and BH driving point, averaged corpus mobility magnitude, or radiativity was found. Increasing averaged-over-f(rock) deltam(g) from 0 to 0.12 generally increased radiativity across the spectrum. Decreasing averaged-over-deltam f(rock) from 3.6 to 2.6 kHz produced consistent decreases in radiativity between 3 and 4.2 kHz, but only few-percent decreases in BH frequency. The lowest f(rock) values were accompanied by significantly reduced radiation from the Helmholtz A0 mode near 280 Hz; this, combined with reduced high frequency output, created overall radiativity profiles quite similar to "bad" violins among the quality-rated violins. PMID:16875244

  14. Simulation of flow and evaluation of bridge scour at Horse Island Chute Bridge near Chester, Illinois

    USGS Publications Warehouse

    Huizinga, Richard J.; Rydlund, Paul H.

    2001-01-01

    The evaluation of scour at bridges throughout the State of Missouri has been ongoing since 1991, and most of these evaluations have used one-dimensional hydraulic analysis and application of conventional scour depth equations. Occasionally, the conditions of a site dictate that a more thorough hydraulic assessment is required. To provide the hydraulic parameters required to determine the potential scour depths at the bridge over Horse Island Chute near Chester, Illinois, a two-dimensional finite-element surface-water model (FESWMS-2DH) was used to simulate flood flows in the vicinity of the Missouri State Highway 51 crossing of the Mississippi River and Horse Island Chute. The model was calibrated using flood-flow information collected during the 1993 flood. A flood profile along the Illinois side of the Mississippi River on August 5, 1993, with a corresponding measured discharge of 944,000 cubic feet per second was used to calibrate the model. Two additional flood-flow simulations were run: the flood peak that occurred on August 6, 1993, with a maximum discharge of 1,000,000 cubic feet per second, and the discharge that caused impending overtopping of the road embankment in the vicinity of the Horse Island Chute bridge, with a discharge of 894,000 cubic feet per second (impendent discharge). Hydraulic flow parameters obtained from the simulations were applied to scour depth equations to determine general contraction and local pier and abutment scour depths at the Horse Island Chute bridge. The measured discharge of 944,000 cubic feet per second resulted in 13.3 feet of total combined contraction and local pier scour at Horse Island Chute bridge. The maximum discharge of 1,000,000 cubic feet per second resulted in 15.8 feet of total scour and the impendent discharge of 894,000 cubic feet per second resulted in 11.6 feet of total scour.

  15. Cascaded resonant bridge converters

    NASA Technical Reports Server (NTRS)

    Stuart, Thomas A. (Inventor)

    1989-01-01

    A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator. The voltage of the second stage output is controlled at a relatively constant value by controlling the first stage output voltage, which is accomplished by controlling the frequency of the first stage variable frequency voltage controller in response to second stage voltage. Fault tolerance in the event of a load short circuit is provided by making the operation of the first stage variable frequency voltage controller responsive to first and second stage current limiting devices. The second stage output is connected to a rectifier bridge whose output is connected to the input of the second stage to provide good regulation of output voltage wave form at low system loads.

  16. Nanoparticle bridge DNA biosensor

    NASA Astrophysics Data System (ADS)

    Huang, Hong-Wen

    A new DNA sensing method is demonstrated in which DNA hybridization events lead to the formation of nanoparticle satellites that bridge two electrodes and are detected electrically. The hybridization events are exclusively carried out only on specific locations, the surfaces of C-ssDNA modified 50 nm GNPs. The uniqueness of this work is that only a small number of T-ccDNA molecules (<10) is required to form the nanoparticle satellites, allowing ultra-sensitive DNA sensing. The principle of this new DNA sensing technique has been demonstrated using target DNA and three-base-pair-mismatched DNA in 20nM concentrations. Three single-stranded DNA (ssDNA) system is used in our experiment which includes Capture-ssDNA (C-ssDNA), Target-ssDNA (T-ssDNA) and Probe-ssDNA (P-ssDNA). Both C-ssDNA and P-ssDNA are modified by a thiol group and can hybridize with different portions of T-ssDNA. T-ssDNA requires no modification in three ssDNA system, which is beneficial in many applications. C-ssDNA modified 50nm gold nanoparticle (C-50au) and P-ssDNA modified 30nm gold nanoparticle (P-30au) are prepared through the reaction of thiol-gold chemical bonding between thiolated ssDNA and gold nanoparticle (GNP) (C-ssDNA with 50nm GNP, P-ssDNA with 30nm GNP). We controllably place the C-50au only on the SiO2 band surface (˜ 90nm width) between two gold electrodes (source and drain electrodes) by forming positively- and negatively-charged self-assembled monolayers (SAMs) on SiO2 and gold surface, respectively. DNA modified GNP is negatively charged due to ionization of phosphate group on DNA back bone. C-50au therefore is negatively charged and can only be attracted toward SiO2 area (repelled by negatively charged gold electrode surface). The amine group of positively-charged SAMs on SiO2 surface is then passivated by converting to non-polar methyl functional group after C-50au placement. P-30au is first hybridized with T-ssDNA in the solution phase (T-P- 30au formed) and is introduced

  17. The formation of liquid bridge in different operating modes of AFM

    NASA Astrophysics Data System (ADS)

    Wei, Zheng; Sun, Yan; Ding, WenXuan; Wang, ZaiRan

    2016-09-01

    The liquid bridge is one of the principal factors that cause artifacts in ambient-pressure atomic force microscope (AFM) images. Additionally, it is the main component of the adhesion force in ambient conditions. To understand the AFM imaging mechanism and the sample characteristics, it is essential to study the liquid bridge. This study interprets the physical mechanism involved in liquid bridge formation, which is composed of three different physical processes: the squeezing process, capillary condensation, and liquid film flow. We discuss the contributions of these three mechanisms to the volume and the capillary force of the liquid bridge in different AFM operation modes.

  18. Bridges to Understanding: Writings by OCC International Students. Spring 1994.

    ERIC Educational Resources Information Center

    McKague, Thomas, Ed.; Waelder, Patricia K., Ed.

    This booklet contains the writings of international students enrolled in the English for Speakers of Other Languages (ESOL) at Onondaga Community College (New York). The contributed writings were viewed as bridges to understanding among the world's peoples. The collection of essays, poems and short stories includes: (1) "Our Lives in the USA"…

  19. Bridging the Relationship Gap: Connecting with Children Facing Adversity

    ERIC Educational Resources Information Center

    Langworthy, Sara E.

    2015-01-01

    Relationships play an important role in human development, especially in the first years of life. "Bridging the Relationship Gap" provides tools and encouragement to be the strong, positive, and nurturing adult these children need in order to thrive. Learn more about the factors that contribute to the achievement and relationship gap…

  20. Liquid-Bridge Breaking Limits

    NASA Astrophysics Data System (ADS)

    Macner, Ashley; Steen, Paul

    2011-11-01

    Wet adhesion by liquid bridges in large arrays shows promise for use in lightweight, controllable on-demand devices. Applications include grab/release of wafer substrates, transport of micron-sized tiles for use in 3D printing and micro-dosing of personalized pharmaceutical drugs. By wetting and spreading, a drop can form a bridge and thereby ``grab'' a nearby solid substrate. By volume decrease or extension, the bridge can break. The breaking limit corresponds to bridge instability which can be predicted, knowing the static mechanical response of the bridge. Mechanical behaviors include force-volume (FV), pressure-volume (pV) and force-length (FL) responses. Instability crucially depends on the mode of failure - failure under constant-force or constant length are typical cases. We study single bridge equilibria for their breaking limits. FV diagrams for the pin-pin equal and pin-pin unequal radii boundary conditions for different bridge heights are measured in the laboratory. The FL response in the case of pin-pin equal radii is also measured. Results are compared to predictions of static theory. Static results are then used to compare to dynamical sequences where volume is driven quasistatically by syringe or an electro-osmotic pump. As the breaking limit is approached, the shape deformation accelerates leading to non-equilibrium shapes not captured by the static analysis.

  1. Research: A Cultural Bridge.

    ERIC Educational Resources Information Center

    Vallance, Roger J.; Tchacos, E.

    An ongoing qualitative cross-cultural research project, using ethnographic methods of immersion and reference to the lived experience, is addressing the high rates of Indigenous youth suicide in remote Kimberley (Western Australia) communities. To ensure that cultural sensitivities are observed and work toward valid data collection and analysis,…

  2. Anticoagulation After Cardioembolic Stroke: To Bridge or Not to Bridge?

    PubMed Central

    Hallevi, Hen; Albright, Karen C.; Martin-Schild, Sheryl; Barreto, Andrew D.; Savitz, Sean I.; Escobar, Miguel A.; Gonzales, Nicole R.; Noser, Elizabeth A.; Illoh, Kachi; Grotta, James C.

    2009-01-01

    Background Most patients with cardioembolic stroke require long-term anticoagulation. Still, uncertainty exists regarding the best mode of starting long-term anticoagulation. Design, Setting, and Patients We conducted a retrospective review of all patients with cardioembolic stroke admitted to our center from April 1, 2004, to June 30, 2006, and not treated with tissue plasminogen activator. Patients were grouped by treatment: no treatment, aspirin only, aspirin followed by warfarin sodium, intravenous heparin sodium in the acute phase followed by warfarin (heparin bridging), and full-dose enoxaparin sodium combined with warfarin (enoxaparin bridging). Outcome measures and adverse events were collected prospectively. Laboratory values were captured from the records. Main Outcome Measures Symptomatic hemorrhagic transformation, stroke progression, and discharge modified Rankin Scale score. Results Two hundred four patients were analyzed. Recurrent stroke occurred in 2 patients (1%). Progressive stroke was the most frequent serious adverse event, seen in 11 patients (5%). Hemorrhagic transformation occurred in a bimodal distribution—an early benign hemorrhagic transformation and a late symptomatic hemorrhagic transformation. All of the symptomatic hemorrhagic transformation cases were in the enoxaparin bridging group (10%) (P=.003). Systemic bleeding occurred in 2 patients (1%) and was associated with heparin bridging (P=.04). Conclusions Anticoagulation of patients with cardioembolic stroke can be safely started with warfarin shortly after stroke. Heparin bridging and enoxaparin bridging increase the risk for serious bleeding. PMID:18625852

  3. Structural monitoring of a highway bridge using passive noise recordings from street traffic.

    PubMed

    Salvermoser, Johannes; Hadziioannou, Céline; Stähler, Simon C

    2015-12-01

    Structural damage on bridges presents a hazard to public safety and can lead to fatalities. This article contributes to the development of an alternative monitoring system for civil structures, based on passive measurements of seismic elastic waves. Cross-correlations of traffic noise recorded at geophone receiver pairs were found to be sufficiently stable for comparison and sensitive to velocity changes in the medium. As such velocity variations could be caused by damage, their detection would be valuable in structural health monitoring systems. A method, originally introduced for seismological applications and named Passive Image Interferometry, was used to quantify small velocity fluctuations in the medium and thereby observe structural changes. Evaluation of more than 2 months of continuous geophone recordings at a reinforced concrete bridge yielded velocity variations Δv/v in the range of -1.5% to +2.1%. The observed fluctuations correlate with associated temperature time series with a striking resemblance which is remarkable for two completely independent data sets. Using a linear regression approach, a relationship between temperature and velocity variations of on average 0.064% °C(-1) can be identified. This value corresponds well to other studies on concrete structures. PMID:26723341

  4. Cross-functional systems

    NASA Technical Reports Server (NTRS)

    Lee, Mark

    1991-01-01

    Many companies, including Xerox and Texas Instruments, are using cross functional systems to deal with the increasingly complex and competitive business environment. However, few firms within the aerospace industry appear to be aware of the significant benefits that cross functional systems can provide. Those benefits are examined and a flexible methodology is discussed that companies can use to identify and develop cross functional systems that will help improve organizational performance. In addition, some of the managerial issues are addressed that cross functional systems may raise and specific examples are used to explore networking's contributions to cross functional systems.

  5. Bridge to a sustainable future

    SciTech Connect

    Houlihan, T.M.

    1996-10-01

    In July, 1994, Vice President Al Gore released the report Technology for a Sustainable Future. The report resulted from an interagency effort under the auspices of the National Science and Technology Council (NSTC). In each of ten critical policy areas, the participants who prepared the report considered where federal government action could encourage new partnerships that would facilitate the development of US environmental technology products and services. The report initiated a national outreach process that has featured participation by a wide range of individuals from industry, state and local governments, academia and the American public. Over 30 workshops across the nation contributed to the understanding of what new policy actions could be formulated to insure that American environmental technology is dominant in the global market. In December of 1994, a White House Conference was held in washington, DC where a total of 1,200 participants joined Cabinet members and the Vice-President to prepare specific strategic elements that would constitute a National Strategy. The culmination of this policy development was reached by the release of the National Environmental Technology Strategy that is entitled Bridge to a Sustainable Future in April 1995 by Vice-President Gore. The Strategy contains a core set of five theme areas that emerged from the outreach process that could be used to guide future activities. Within each theme area is presented a significant finding that was determined from stakeholder inputs, a goal that was established in response to the finding, and sets of initiatives that together articulate a technological path that will lead the nation toward sustainable development. This paper relates the determinations made in some of these areas. In addition it will delineate the partnership roles that will be necessary to accomplish the goals of the national strategy.

  6. Urban Climate Change Resilience as a Teaching Tool for a STEM Summer Bridge Program

    NASA Astrophysics Data System (ADS)

    Rosenzweig, B.; Vorosmarty, C. J.; Socha, A.; Corsi, F.

    2015-12-01

    Community colleges have been identified as important gateways for the United States' scientific workforce development. However, students who begin their higher education at community colleges often face barriers to developing the skills needed for higher-level STEM careers, including basic training in mathematics, programming, analytical problem solving, and cross-disciplinary communication. As part of the Business Higher Education Forum's Undergraduate STEM Interventions in Industry (USI2) Consortium, we are developing a summer bridge program for students in STEM fields transferring from community college to senior (4-year) colleges at the City University of New York. Our scientific research on New York City climate change resilience will serve as the foundation for the bridge program curriculum. Students will be introduced to systems thinking and improve their analytical skills through guided problem-solving exercises using the New York City Climate Change Resilience Indicators Database currently being developed by the CUNY Environmental Crossroads Initiative. Students will also be supported in conducting an introductory, independent research project using the database. The interdisciplinary nature of climate change resilience assessment will allow students to explore topics related to their STEM field of interest (i.e. engineering, chemistry, and health science), while working collaboratively across disciplines with their peers. We hope that students that participate in the bridge program will continue with their research projects through their tenure at senior colleges, further enhancing their academic training, while actively contributing to the study of urban climate change resilience. The effectiveness of this approach will be independently evaluated by NORC at the University of Chicago, as well as through internal surveying and long-term tracking of participating student cohorts.

  7. The Influence of an Unstable Surface on Trunk and Lower Extremity Muscle Activities during Variable Bridging Exercises

    PubMed Central

    Kim, Jung-hyun; Kim, Young; Chung, Yijung

    2014-01-01

    [Purpose] The aim of this study was to investigate the influence of an unstable surface on trunk and lower extremity muscle activities during various types of bridging exercises. [Subjects] Thirty healthy female adults voluntarily participated in this study. [Methods] All subjects were asked to perform 3 different bridging exercises (bridging exercise, single leg lift bridging exercise, single leg cross bridging exercise) with and without an unstable surface. The trunk and lower extremity muscle activities were measured by using surface electromyography during bridging exercise. [Results] During the bridging exercise (BE), single leg lift bridging exercise (LBE), and single leg cross bridging exercise (CBE), the muscle activities of the external oblique muscle (EO), erector spinae (ES), and biceps femoris (BF) were significantly higher on an unstable surface than on a stable surface. The muscle activities of the EO on both sides, contralateral BF, and ipsilateral ES were significantly higher during LBE than during BE and CBE. [Conclusion] Use of an unstable surface increases muscle activity of the trunk and lower extremities, and single leg lift bridging exercise increases the muscle activity of the EO on both sides, ipsilateral ES, and contralateral BF. PMID:24764625

  8. Investigation of fiber bridging in double cantilever beam specimens

    NASA Technical Reports Server (NTRS)

    Johnson, W. S.; Mangalgiri, P. D.

    1987-01-01

    The possibility to eliminate fiber bridging or at least to reduce it, and to evaluate an alternative approach for determination of in situ mode 7 fracture toughness values of composite matrix materials were investigated. Double cantilver beam (DCB) specimens were made using unidirectional lay-ups of T6C/Hx205 composite material in which the delaminating halves were placed at angles of 0, 1.5, and 3 degrees to each other. The small angles between the delaminating plies were used to avoid fiber nesting without significantly affecting mode I teflon insert. The DCB specimens were fabricated and it was found that: (1) the extent which fiber bridging and interlaminar toughness increase with crack length can be reduced by slight cross ply at the delamination plane to reduce fiber nesting; (2) some fiber bridging may occur even in the absence of fiber nesting; (3) the first values of toughness measured ahead of the thin teflon insert are very close to the toughness of the matrix material with no fiber bridging; (4) thin adhesive bondline of matrix material appears to give toughness values equal to the interlaminar toughness of the composite matrix without fiber bridging.

  9. Investigation of fiber bridging in double cantilever beam specimens

    NASA Technical Reports Server (NTRS)

    Johnson, W. S.; Managalgiri, P. D.

    1986-01-01

    The possibility to eliminate fiber bridging or at least to reduce it, and to evaluate an alternative approach for determination of in situ mode 7 fracture toughness values of composite matrix materials were investigated. Double cantilever beam (DCB) specimens were made using unidirectional lay-ups of T6C/Hx205 composite material in which the delaminating halves were placed at angles of 0, 1.5, and 3 degrees to each other. The small angles between the delaminating plies were used to avoid fiber nesting without significantly affecting mode I teflon insert. The DCB specimens were fabricated and it was found that: (1) the extent which fiber bridging and interlaminar toughness increase with crack length can be reduced by slight cross ply at the delamination plane to reduce fiber nesting; (2) some fiber bridging may occur even in the absence of fiber nesting; (3) the first values of toughness measured ahead of the thin teflon insert are very close to the toughness of the matrix material with no fiber bridging; (4) thin adhesive bondline of matrix material appears to give toughness values equal to the interlaminar toughness of the composite matrix without fiber bridging.

  10. Evaluating the performance of skewed prestressed concrete bridge after strengthening

    NASA Astrophysics Data System (ADS)

    Naser, Ali; Zonglin, Wang

    2013-06-01

    The objectives of this paper are to explain the application of repairing and strengthening methods on the damaged members of the bridge structure, to analyze the static and dynamic structural response under static and dynamic loads after strengthening, and to evaluate the structural performance after application of strengthening method. The repairing and strengthening methods which are used in this study include treatment of the cracks, thickening the web of box girder along the bridge length and adding internal pre-stressing tendons in the thickening web, and construct reinforced concrete cross beams (diaphragms) between two box girders. The results of theoretical analysis of static and dynamic structural responses after strengthening show that the tensile stresses are decreased and become less than the allowable limit values in the codes. The values of vertical deflection are decreased after strengthening. The values of natural frequencies after strengthening are increased, indicating that the strengthening method is effective to reduce the vibration of the bridge structure. Therefore, the strengthening methods are effective to improve the bearing capacity and elastic working state of the bridge structure and to increase the service life of the bridge structure.

  11. Real-time seismic monitoring of the integrated cape girardeau bridge array and recorded earthquake response

    USGS Publications Warehouse

    Celebi, M.

    2006-01-01

    This paper introduces the state of the art, real-time and broad-band seismic monitoring network implemented for the 1206 m [3956 ft] long, cable-stayed Bill Emerson Memorial Bridge in Cape Girardeau (MO), a new Mississippi River crossing, approximately 80 km from the epicentral region of the 1811-1812 New Madrid earthquakes. The bridge was designed for a strong earthquake (magnitude 7.5 or greater) during the design life of the bridge. The monitoring network comprises a total of 84 channels of accelerometers deployed on the superstructure, pier foundations and at surface and downhole free-field arrays of the bridge. The paper also presents the high quality response data obtained from the network. Such data is aimed to be used by the owner, researchers and engineers to assess the performance of the bridge, to check design parameters, including the comparison of dynamic characteristics with actual response, and to better design future similar bridges. Preliminary analyses of ambient and low amplitude small earthquake data reveal specific response characteristics of the bridge and the free-field. There is evidence of coherent tower, cable, deck interaction that sometimes results in amplified ambient motions. Motions at the lowest tri-axial downhole accelerometers on both MO and IL sides are practically free from any feedback from the bridge. Motions at the mid-level and surface downhole accelerometers are influenced significantly by feedback due to amplified ambient motions of the bridge. Copyright ASCE 2006.

  12. Stability of liquid crystalline bridges

    NASA Astrophysics Data System (ADS)

    Mahajan, Milind P.; Tsige, Mesfin; Taylor, P. L.; Rosenblatt, Charles

    1999-02-01

    The stability of cylindrical bridges of the liquid crystal octylcyanobiphenyl in an immiscible liquid bath was investigated in the nematic and smectic A phases. In the nematic phase the bridge was found to destabilize at a length-to-diameter (slenderness) ratio R similar to that of ordinary Newtonian fluids. On the other hand, the Bingham behavior of the smectic A phase, i.e., an apparent yield stress, enabled the formation of stable columns with R well in excess of π.

  13. 77 FR 16784 - General Bridge Regulation; Amendment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-22

    ... SECURITY Coast Guard 33 CFR Part 114, 116, 118 RIN 1625-AB36 General Bridge Regulation; Amendment AGENCY... rulemaking concerning amendments to the general bridge regulations. The rulemaking was initiated to clarify the statutory responsibilities of bridge owners to remove their bridges from navigable waterways...

  14. Sacrificial bridges for MEMS fabrication

    NASA Astrophysics Data System (ADS)

    Chang, Chao-Min; Chen, Yang-Che; Fong, Chien-Fu; Guu, Yunn-Horng; Chen, Rongshun; Yeh, J. Andrew; Hou, Max T.

    2011-09-01

    This study discusses sacrificial bridges that are used to release MEMS devices. Before being released, sacrificial bridges connect all the component structures into an integral structure. Solder bump bonding is used to mount the MEMS chip on another chip or a printed circuit board (PCB) and to maintain the alignment among all component structures after removal of the sacrificial bridges. Two types of sacrificial bridges were designed, analyzed and fabricated. The fabrication process—which used low resistivity single crystal silicon (SCS) wafers as the device material—was developed to implement the sacrificial bridges. Novel SCS through silicon vias (TSVs), which interconnect stacked chips, was made using the same process. An electrostatic comb drive actuator was fabricated and mounted onto a PCB. The fabricated actuator was tested to demonstrate the feasibility of the fabrication process, sacrificial bridges and SCS TSVs. The results show that the actuator worked well. Its maximum displacement and resonant frequency were 69.9 µm and 406 Hz, respectively. This method is promising for the delivery of a novel 3D system in package for MEMS devices.

  15. OVERVIEW OF BRIDGES WITH WAIKELE CANAL BRIDGE IN CENTER, OR&L ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OVERVIEW OF BRIDGES WITH WAIKELE CANAL BRIDGE IN CENTER, OR&L BRIDGE IN BACKGROUND. SHOWING THE EARTHEN INCLINE THAT RAISES FARRINGTON HIGHWAY OVER THE FORMER OR&L TRACKS. NOTE THE 1963 WESTBOUND BRIDGE IN THE FOREGROUND. VIEW FACING EAST. - Waikele Canal Bridge and Highway Overpass, Farrington Highway and Waikele Stream, Waipahu, Honolulu County, HI

  16. Cross-Cultural Psychology.

    ERIC Educational Resources Information Center

    Triandis, Harry C.; Brislin, Richard W.

    1984-01-01

    Provides references to the work of cross-cultural psychologists that can be integrated into regular undergraduate psychology courses. Discusses methodological problems, benefits, and difficulties of cross-cultural research. Reviews contributions of this field to the study of perception, cognition, motivation, interpersonal interaction, and group…

  17. Development of Inspection Robots for Bridge Cables

    PubMed Central

    Kim, Se-Hoon; Lee, Jong-Jae

    2013-01-01

    This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented. PMID:24459453

  18. Evaluation of Fluoride Retention Due to Most Commonly Consumed Estuarine Fishes Among Fish Consuming Population of Andhra Pradesh as a Contributing Factor to Dental Fluorosis: A Cross-Sectional Study

    PubMed Central

    Ganta, Shravani; Nagaraj, Anup; Pareek, Sonia; Sidiq, Mohsin; Singh, Kushpal; Vishnani, Preeti

    2015-01-01

    Background Fluoride in drinking water is known for both beneficial and detrimental effects on health. The principal sources of fluoride include water, some species of vegetation, certain edible marine animals, dust and industrial processes. The purpose of this study was to evaluate the fluoride retention of most commonly consumed estuarine fishes among fish consuming population of Andhra Pradesh. Materials and Methods A cross-sectional study was conducted to evaluate the amount of fluoride retention due to ten most commonly consumed estuarine fishes as a contributing factor to Fluorosis by SPADNS Spectrophotometric method. The presence and severity of dental fluorosis among fish consuming population was recorded using Community Fluorosis Index. Statistical analysis was done using MedCalc v12.2.1.0 software. Results For Sea water fishes, the fluoride levels in bone were maximum in Indian Sardine (4.22 ppm). Amongst the river water fishes, the fluoride levels in bone were maximum in Catla (1.51 ppm). Also, the mean total fluoride concentrations of all the river fishes in skin, muscle and bone were less (0.86 ppm) as compared to the sea water fishes (2.59 ppm). It was unveiled that sea fishes accumulate relatively large amounts of Fluoride as compared to the river water fishes. The mean Community Fluorosis Index was found to be 1.06 amongst a sampled fish consuming population. Evaluation by Community Index for Dental fluorosis (CFI) suggested that fluorosis is of medium public health importance. Conclusion It was analysed that bone tends to accumulate more amount of fluoride followed by muscle and skin which might be due to the increased permeability and chemical trapping of fluoride inside the tissues. The amount of fluoride present in the fishes is directly related to the severity of fluorosis amongst fish consuming population, suggesting fishes as a contributing factor to fluorosis depending upon the dietary consumption. PMID:26266208

  19. Proton production, neutralisation and reduction in a floating water bridge

    NASA Astrophysics Data System (ADS)

    Sammer, Martina; Wexler, Adam D.; Kuntke, Philipp; Wiltsche, Helmar; Stanulewicz, Natalia; Lankmayr, Ernst; Woisetschläger, Jakob; Fuchs, Elmar C.

    2015-10-01

    This work reports on proton production, transport, reduction and neutralization in floating aqueous bridges under the application of a high dc voltage (‘floating water bridge’). Recently possible mechanisms for proton transfer through the bridge were suggested. In this work we visualize and describe the production of protons in the anolyte and their neutralization in the catholyte. Apart from that, protons are reduced to hydrogen due to electrolysis. Microbubbles are detached instantly, due to the electrohydrodynamic flow at the electrode surface. No larger, visible bubbles are formed and the system degasses through the bridge due to its higher local temperature. A detailed analysis of trace elements originating from beaker material, anode or the atmosphere is presented, showing that their influence on the overall conduction compared to the contribution of protons is negligible. Finally, an electrochemical rationale of high voltage electrolysis of low ionic strength solutions is presented.

  20. Bridging Media with the Help of Players

    NASA Astrophysics Data System (ADS)

    Nitsche, Michael; Drake, Matthew; Murray, Janet

    We suggest harvesting the power of multiplayer design to bridge content across different media platforms and develop player-driven cross-media experiences. This paper first argues to partially replace complex AI systems with multiplayer design strategies to provide the necessary level of flexibility in the content generation for cross-media applications. The second part describes one example project - the Next Generation Play (NGP) project - that illustrates one practical approach of such a player-driven cross-media content generation. NGP allows players to collect virtual items while watching a TV show. These items are re-used in a multiplayer casual game that automatically generates new game worlds based on the various collections of active players joining a game session. While the TV experience is designed for the single big screen, the game executes on multiple mobile phones. Design and technical implementation of the prototype are explained in more detail to clarify how players carry elements of television narratives into a non-linear handheld gaming experience. The system describes a practical way to create casual game adaptations based on players' personal preferences in a multi-user environment.

  1. 49 CFR 213.235 - Inspection of switches, track crossings, and lift rail assemblies or other transition devices on...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... TRANSPORTATION TRACK SAFETY STANDARDS Inspection § 213.235 Inspection of switches, track crossings, and lift rail... section, each switch, turnout, track crossing, and moveable bridge lift rail assembly or other transition... once a month, each switch, turnout, track crossing, and moveable bridge lift rail assembly or...

  2. 49 CFR 213.235 - Inspection of switches, track crossings, and lift rail assemblies or other transition devices on...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... TRANSPORTATION TRACK SAFETY STANDARDS Inspection § 213.235 Inspection of switches, track crossings, and lift rail... section, each switch, turnout, track crossing, and moveable bridge lift rail assembly or other transition... once a month, each switch, turnout, track crossing, and moveable bridge lift rail assembly or...

  3. 49 CFR 213.235 - Inspection of switches, track crossings, and lift rail assemblies or other transition devices on...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... TRANSPORTATION TRACK SAFETY STANDARDS Inspection § 213.235 Inspection of switches, track crossings, and lift rail... section, each switch, turnout, track crossing, and moveable bridge lift rail assembly or other transition... once a month, each switch, turnout, track crossing, and moveable bridge lift rail assembly or...

  4. 25. Otter Creek Bridge #2. View of the stone facing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. Otter Creek Bridge #2. View of the stone facing common on nearly all concrete box culverts. The stone faced arch mimics rigid frame structures. Culverts were used for a variety of purposes from small stream crossings to grade separation structures for farmers whose land was split by the parkway. Looking northeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  5. 17. LOOKING DUE EAST FROM OPERATOR'S HOUSE, WITH TRAIN CROSSING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. LOOKING DUE EAST FROM OPERATOR'S HOUSE, WITH TRAIN CROSSING BRIDGE (MOVING TOWARD CAMERA). NOTE JOINT BETWEEN SWING SPAN AND FIXED APPROACH SPAN AT BOTTOM RIGHT OF FRAME. - Chicago, Milwaukee & St. Paul Railway, Bridge No. Z-6, Spanning North Branch of Chicago River, South of Cortland Street, Chicago, Cook County, IL

  6. 12. Readville showing the intersection of the Franklin Branch crossing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Readville showing the intersection of the Franklin Branch crossing the Northeast Corridor (formerly the Boston & Providence RR) on the bridge; Readville Station to the right of bridge. Readville, Suffolk Co., MA. Sec. 4116, MP 219.41. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

  7. Tsunamis: bridging science, engineering and society.

    PubMed

    Kânoğlu, U; Titov, V; Bernard, E; Synolakis, C

    2015-10-28

    Tsunamis are high-impact, long-duration disasters that in most cases allow for only minutes of warning before impact. Since the 2004 Boxing Day tsunami, there have been significant advancements in warning methodology, pre-disaster preparedness and basic understanding of related phenomena. Yet, the trail of destruction of the 2011 Japan tsunami, broadcast live to a stunned world audience, underscored the difficulties of implementing advances in applied hazard mitigation. We describe state of the art methodologies, standards for warnings and summarize recent advances in basic understanding, and identify cross-disciplinary challenges. The stage is set to bridge science, engineering and society to help build up coastal resilience and reduce losses. PMID:26392618

  8. Bridging Organizations Drive Effective Governance Outcomes for Conservation of Indonesia's Marine Systems.

    PubMed

    Berdej, Samantha M; Armitage, Derek R

    2016-01-01

    This study empirically investigates the influence of bridging organizations on governance outcomes for marine conservation in Indonesia. Conservation challenges require ways of governing that are collaborative and adaptive across boundaries, and where conservation actions are better coordinated, information flows improved, and knowledge better integrated and mobilized. We combine quantitative social network analysis and qualitative data to analyze bridging organizations and their networks, and to understand their contributions and constraints in two case studies in Bali, Indonesia. The analysis shows 1) bridging organizations help to navigate the 'messiness' inherent in conservation settings by compensating for sparse linkages, 2) the particular structure and function of bridging organizations influence governing processes (i.e., collaboration, knowledge sharing) and subsequent conservation outcomes, 3) 'bridging' is accomplished using different strategies and platforms for collaboration and social learning, and 4) bridging organizations enhance flexibility to adjust to changing marine conservation contexts and needs. Understanding the organizations that occupy bridging positions, and how they utilize their positionality in a governance network is emerging as an important determinant of successful conservation outcomes. Our findings contribute to a relatively new body of literature on bridging organizations in marine conservation contexts, and add needed empirical investigation into their value to governance and conservation in Coral Triangle nations and beyond. PMID:26794003

  9. Construction engineering of steel tub-girder bridge systems for skew effects

    NASA Astrophysics Data System (ADS)

    Jimenez Chong, Juan Manuel

    Closed structural sections, such as those having circular, rectangular or trapezoidal shape, possess high rotational rigidity when compared to open sections such as I-girders. The high torsional rigidity of closed sections makes them ideal for use in highly curved bridges. In this case, the geometry of the bridge results in large torsional forces. Because of structural efficiency and economy reasons, most of these closed-section bridges consist of a trapezoidal cross-section, with a top concrete slab and bottom and side steel plates. The slab is cast after the steel is erected and thus a system of internal diaphragms and braces is necessary to stabilize the system during erection. During the steel erection and the early stages of the concrete deck placement, the section can be considered as quasi-closed as the top concrete flange has not been cast or is not yet effective. During steel erection, undetermined and/or large torsional forces and/or displacements may result in fit-up problems requiring large stresses to overcome. During concrete deck placement, the undetermined displacements can affect the control of the deck thickness and the final deck geometry, such as the alignment of deck joints and the matching of stages in phased constructions projects. Due to the interactions between their various components, the behavior of curved and skewed tub-girder bridges is significantly more complex than that of straight bridges. When skewed supports are used in tub-girders, the interaction of the girder bending rotations and the displacement constraints induced by the skewed support diaphragms causes twisting of the girders at the supports. These twist rotations introduce additional torques into the system. Both curvature and skew can cause design and construction difficulties, especially at the supports, where the corresponding steel dead load deflections and the large torsional stiffness of the girders may lead to large fit-up forces. Currently, the general

  10. Floating liquid bridge charge dynamics

    NASA Astrophysics Data System (ADS)

    Teschke, Omar; Soares, David Mendez; Gomes, Whyllerson Evaristo; Valente Filho, Juracyr Ferraz

    2016-01-01

    The interaction of liquid with electric fields is investigated in a configuration where up to 13 kV are applied between electrodes resulting in a 106 V/m electric field in the capillaries and where there is the formation of a free-standing fluid bridge in the interelectrode gap. The Mott-Gurney equation was fitted to the measured ionization current vs applied voltage curve which indicates that the ionization rate at the high-voltage anode electrode dimethylsulfoxide (DMSO) interface and space charging in the interelectrode gap determine the floating liquid bridge current for a given cathode-to-anode voltage. Space charge effects were measured in the cathode becker and also at the liquid bridge since the ionized charges at the anode migrate to the bridge outer surface and decrease the interfacial tension from 43 mJ/m2 to 29 mJ/m2. Two distinct structural regions then form the bridge, a charged plastic (bulk modulus ˜100 MPa) conducting outer layer with a surface conductivity of ˜10-9 Ω-1, which shapes and supports the floating fluid structure, and an inner liquid cylinder, where DMSO molecules flow.

  11. Long-Term Structural Health Monitoring System for a High-Speed Railway Bridge Structure

    PubMed Central

    Ding, You-Liang; Wang, Gao-Xin; Sun, Peng; Wu, Lai-Yi; Yue, Qing

    2015-01-01

    Nanjing Dashengguan Bridge, which serves as the shared corridor crossing Yangtze River for both Beijing-Shanghai high-speed railway and Shanghai-Wuhan-Chengdu railway, is the first 6-track high-speed railway bridge with the longest span throughout the world. In order to ensure safety and detect the performance deterioration during the long-time service of the bridge, a Structural Health Monitoring (SHM) system has been implemented on this bridge by the application of modern techniques in sensing, testing, computing, and network communication. The SHM system includes various sensors as well as corresponding data acquisition and transmission equipment for automatic data collection. Furthermore, an evaluation system of structural safety has been developed for the real-time condition assessment of this bridge. The mathematical correlation models describing the overall structural behavior of the bridge can be obtained with the support of the health monitoring system, which includes cross-correlation models for accelerations, correlation models between temperature and static strains of steel truss arch, and correlation models between temperature and longitudinal displacements of piers. Some evaluation results using the mean value control chart based on mathematical correlation models are presented in this paper to show the effectiveness of this SHM system in detecting the bridge's abnormal behaviors under the varying environmental conditions such as high-speed trains and environmental temperature. PMID:26451387

  12. Long-Term Structural Health Monitoring System for a High-Speed Railway Bridge Structure.

    PubMed

    Ding, You-Liang; Wang, Gao-Xin; Sun, Peng; Wu, Lai-Yi; Yue, Qing

    2015-01-01

    Nanjing Dashengguan Bridge, which serves as the shared corridor crossing Yangtze River for both Beijing-Shanghai high-speed railway and Shanghai-Wuhan-Chengdu railway, is the first 6-track high-speed railway bridge with the longest span throughout the world. In order to ensure safety and detect the performance deterioration during the long-time service of the bridge, a Structural Health Monitoring (SHM) system has been implemented on this bridge by the application of modern techniques in sensing, testing, computing, and network communication. The SHM system includes various sensors as well as corresponding data acquisition and transmission equipment for automatic data collection. Furthermore, an evaluation system of structural safety has been developed for the real-time condition assessment of this bridge. The mathematical correlation models describing the overall structural behavior of the bridge can be obtained with the support of the health monitoring system, which includes cross-correlation models for accelerations, correlation models between temperature and static strains of steel truss arch, and correlation models between temperature and longitudinal displacements of piers. Some evaluation results using the mean value control chart based on mathematical correlation models are presented in this paper to show the effectiveness of this SHM system in detecting the bridge's abnormal behaviors under the varying environmental conditions such as high-speed trains and environmental temperature. PMID:26451387

  13. 13. A streetcar crosses the Cuyahoga River in the waning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. A streetcar crosses the Cuyahoga River in the waning days of Cleveland's trolley age. Copy of photograph taken by Herbert H. Harwood, Jr., Baltimore, Maryland, photo courtesy Mr. Harwood - Detroit Superior High Level Bridge, Cleveland, Cuyahoga County, OH

  14. Detail of inside of inclined end post, with portal cross ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of inside of inclined end post, with portal cross bar member. - Phoenix Iron Company, French Creek Bridge, Spanning French Creek between Gay Street & Main Street, Phoenixville, Chester County, PA

  15. Training: Bridging the gap

    SciTech Connect

    Not Available

    1991-07-01

    These proceedings contain abstracts and papers of the general subject of training for the US DOE by Oak Ridge Associated Universities (ORAU). ORAU is a consortium of colleges and universities that explore opportunities, solve problems, and seek to make increasingly positive contributions to society through science and technology. ORAU operates in four major areas:medical sciences, science and engineering education, training and management systems, and energy and environment systems. Training programs at the Y-12 plant, WMCO, the Mound Laboratory, Sandia laboratories, Hanford, Rocky Flats plant, Los Alamos National Laboratory, and other DOE contractor facilities are presented. Individual papers are indexed separately.

  16. Building a Bridge to Cross a Thousand Years

    ERIC Educational Resources Information Center

    Lippert, Dorothy

    2006-01-01

    The practice of archaeology includes of a series of events in which a group of objects is transformed from their initial identities as household goods, religious objects, or detritus of everyday life into artifacts, or as the 1906 Antiquities Act describes them, "objects of antiquity." Frequently, artifacts are further re-identified as part of a…

  17. Kinesin-5: cross-bridging mechanism to targeted clinical therapy

    PubMed Central

    Wojcik, Edward J.; Buckley, Rebecca S.; Richard, Jessica; Liu, Liqiong; Huckaba, Thomas M.; Kim, Sunyoung

    2013-01-01

    Kinesin motor proteins comprise an ATPase superfamily that goes hand in hand with microtubules in every eukaryote. The mitotic kinesins, by virtue of their potential therapeutic role in cancerous cells, have been a major focus of research for the past 28 years since the discovery of the canonical Kinesin-1 heavy chain. Perhaps the simplest player in mitotic spindle assembly, Kinesin-5 (also known as Kif11, Eg5, or kinesin spindle protein, KSP) is a plus-end-directed motor localized to interpolar spindle microtubules and to the spindle poles. Comprised of a homotetramer complex, its function primarily is to slide anti-parallel microtubules apart from one another. Based on a multi-faceted analysis of this motor from numerous laboratories over the years, we have learned a great deal about the function of this motor at the atomic level for catalysis and as an integrated element of the cytoskeleton. These data have, in turn, informed the function of motile kinesins on the whole, as well as spearheaded integrative models of the mitotic apparatus in particular and regulation of the microtubule cytoskeleton in general. We review what is known about how this nanomotor works, its place inside the cytoskeleton of cells, and its small-molecule inhibitors that provide a toolbox for understanding motor function and for anticancer treatment in the clinic. PMID:23954229

  18. Crossing the Vocabulary Bridge: Differentiated Strategies for Diverse Secondary Classrooms

    ERIC Educational Resources Information Center

    Herrera, Socorro G.; Kavimandan, Shabina K.; Holmes, Melissa A.

    2011-01-01

    In her new book, nationally known professional development consultant and literacy expert Socorro Herrera is joined by two colleagues to provide a framework for academic vocabulary and language instruction in today's diverse classrooms. The authors present a set of strategies and tools that work effectively across all content to support enhanced…

  19. Building Bridges: A Cross-Disciplinary Experiment in Adult Education

    ERIC Educational Resources Information Center

    Klingbeil, Gerald A.

    2013-01-01

    Biblical texts and ancient Near Eastern pictorial images and material culture are separated by thousands of years from people living in the 21st century. This not only represents a temporal divide, but also a significant ideological (or worldview) divide. Following a brief introduction to important principles of adult-educational theory, this…

  20. REVIEW: Oxytocin: Crossing the bridge between basic science and pharmacotherapy.

    PubMed

    Viero, Cedric; Shibuya, Izumi; Kitamura, Naoki; Verkhratsky, Alexei; Fujihara, Hiroaki; Katoh, Akiko; Ueta, Yoichi; Zingg, Hans H; Chvatal, Alexandr; Sykova, Eva; Dayanithi, Govindan

    2010-10-01

    Is oxytocin the hormone of happiness? Probably not. However, this small nine amino acid peptide is involved in a wide variety of physiological and pathological functions such as sexual activity, penile erection, ejaculation, pregnancy, uterus contraction, milk ejection, maternal behavior, osteoporosis, diabetes, cancer, social bonding, and stress, which makes oxytocin and its receptor potential candidates as targets for drug therapy. In this review, we address the issues of drug design and specificity and focus our discussion on recent findings on oxytocin and its heterotrimeric G protein-coupled receptor OTR. In this regard, we will highlight the following topics: (i) the role of oxytocin in behavior and affectivity, (ii) the relationship between oxytocin and stress with emphasis on the hypothalamo-pituitary-adrenal axis, (iii) the involvement of oxytocin in pain regulation and nociception, (iv) the specific action mechanisms of oxytocin on intracellular Ca²(+) in the hypothalamo neurohypophysial system (HNS) cell bodies, (v) newly generated transgenic rats tagged by a visible fluorescent protein to study the physiology of vasopressin and oxytocin, and (vi) the action of the neurohypophysial hormone outside the central nervous system, including the myometrium, heart and peripheral nervous system. As a short nine amino acid peptide, closely related to its partner peptide vasopressin, oxytocin appears to be ideal for the design of agonists and antagonists of its receptor. In addition, not only the hormone itself and its binding to OTR, but also its synthesis, storage and release can be endogenously and exogenously regulated to counteract pathophysiological states. Understanding the fundamental physiopharmacology of the effects of oxytocin is an important and necessary approach for developing a potential pharmacotherapy. PMID:20626426