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Sample records for cross bridges contribute

  1. 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

    2009-05-06

    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.

  2. Cooperative Cross-Bridge Activation of Thin Filaments Contributes to the Frank-Starling Mechanism in Cardiac Muscle

    PubMed Central

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

    2009-01-01

    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 [Ca2+] and [Vi]. Increasing [Vi] (decreased force) reduced the pCa50 of force-[Ca2+] relations at 2.3 and 2.0 μm SL, with little effect on slope (nH). When maximum force was inhibited to ∼40%, the effects of SL on force were diminished at lower [Ca2+], whereas at higher [Ca2+] (pCa < 5.6) the relative influence of SL on force increased. In contrast, force inhibition to ∼20% significantly reduced the sensitivity of force-[Ca2+] 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. Bridge Crossing Simulator

    DTIC Science & Technology

    2014-10-07

    reaction structure, and a control system, the BCS physically simulates vehicular crossing loads for the expected life span of the bridge undergoing...information provided by the customer. In general, statics will be used to determine equations for moments and deflections based on the specific bridge ...systems. Through the use of hydraulic actuators, a reaction structure, and a control system, the Bridge Crossing Simulator physically simulates vehicular

  4. Pre-Power-Stroke Cross-Bridges Contribute to Force Transients during Imposed Shortening in Isolated Muscle Fibers

    PubMed Central

    Minozzo, Fabio C.; Hilbert, Lennart; Rassier, Dilson E.

    2012-01-01

    When skeletal muscles are activated and mechanically shortened, the force that is produced by the muscle fibers decreases in two phases, marked by two changes in slope (P1 and P2) that happen at specific lengths (L1 and L2). We tested the hypothesis that these force transients are determined by the amount of myosin cross-bridges attached to actin and by changes in cross-bridge strain due to a changing fraction of cross-bridges in the pre-power-stroke state. Three separate experiments were performed, using skinned muscle fibers that were isolated and subsequently (i) activated at different Ca2+ concentrations (pCa2+ 4.5, 5.0, 5.5, 6.0) (n = 13), (ii) activated in the presence of blebbistatin (n = 16), and (iii) activated in the presence of blebbistatin at varying velocities (n = 5). In all experiments, a ramp shortening was imposed (amplitude 10%Lo, velocity 1 Lo•sarcomere length (SL)•s−1), from an initial SL of 2.5 µm (except by the third group, in which velocities ranged from 0.125 to 2.0 Lo•s−1). The values of P1, P2, L1, and L2 did not change with Ca2+ concentrations. Blebbistatin decreased P1, and it did not alter P2, L1, and L2. We developed a mathematical cross-bridge model comprising a load-dependent power-stroke transition and a pre-power-stroke cross-bridge state. The P1 and P2 critical points as well as the critical lengths L1 and L2 were explained qualitatively by the model, and the effects of blebbistatin inhibition on P1 were also predicted. Furthermore, the results of the model suggest that the mechanism by which blebbistatin inhibits force is by interfering with the closing of the myosin upper binding cleft, biasing cross-bridges into a pre-power-stroke state. PMID:22242168

  5. Pre-power-stroke cross-bridges contribute to force transients during imposed shortening in isolated muscle fibers.

    PubMed

    Minozzo, Fabio C; Hilbert, Lennart; Rassier, Dilson E

    2012-01-01

    When skeletal muscles are activated and mechanically shortened, the force that is produced by the muscle fibers decreases in two phases, marked by two changes in slope (P₁ and P₂) that happen at specific lengths (L₁ and L₂). We tested the hypothesis that these force transients are determined by the amount of myosin cross-bridges attached to actin and by changes in cross-bridge strain due to a changing fraction of cross-bridges in the pre-power-stroke state. Three separate experiments were performed, using skinned muscle fibers that were isolated and subsequently (i) activated at different Ca²⁺ concentrations (pCa²⁺ 4.5, 5.0, 5.5, 6.0) (n = 13), (ii) activated in the presence of blebbistatin (n = 16), and (iii) activated in the presence of blebbistatin at varying velocities (n = 5). In all experiments, a ramp shortening was imposed (amplitude 10%L₀, velocity 1 L₀•sarcomere length (SL)•s⁻¹), from an initial SL of 2.5 µm (except by the third group, in which velocities ranged from 0.125 to 2.0 L₀•s⁻¹). The values of P₁, P₂, L₁, and L₂ did not change with Ca²⁺ concentrations. Blebbistatin decreased P₁, and it did not alter P₂, L₁, and L₂. We developed a mathematical cross-bridge model comprising a load-dependent power-stroke transition and a pre-power-stroke cross-bridge state. The P₁ and P₂ critical points as well as the critical lengths L₁ and L₂ were explained qualitatively by the model, and the effects of blebbistatin inhibition on P₁ were also predicted. Furthermore, the results of the model suggest that the mechanism by which blebbistatin inhibits force is by interfering with the closing of the myosin upper binding cleft, biasing cross-bridges into a pre-power-stroke state.

  6. 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

  7. 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

  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... SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely. Bridges crossing a body of water at an angle other than 90° with the axis of the channel shall be lighted...

  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... SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely. Bridges crossing a body of water at an angle other than 90° with the axis of the channel shall be lighted...

  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. 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....

  13. 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...

  14. 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

  15. 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

  16. 2. PASADENA AVENUE BRIDGE CROSSING ARROYO SECO PARKWAY. SEEN FROM ...

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

    2. PASADENA AVENUE BRIDGE CROSSING ARROYO SECO PARKWAY. SEEN FROM CARLOTA BOULEVARD. LOOKING 218°SW. - Arroyo Seco Parkway, Pasadena Avenue Bridge, Milepost 26.48, Los Angeles, Los Angeles County, CA

  17. Superstructure Main Bridge, Cross Sections, Cantilever Structure Huey ...

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

    Superstructure - Main Bridge, Cross Sections, Cantilever Structure - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  18. 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

  19. 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

  20. 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

  1. Concentration and elongation of attached cross-bridges as pressure determinants in a ventricular model.

    PubMed

    Negroni, J A; Lascano, E C

    1999-08-01

    A ventricular model based on a muscle model relating sarcomere dynamics to Ca(2+)kinetics was used to establish the relative contribution to pressure development of the two components of cross-bridge dynamics: attached cross-bridge concentration and elongation of its elastic structure. The model was tested by reproduction of experiments reflecting myofibrillar behavior at the ventricular level as well as chamber mechanical properties. It was then used to study cross-bridge behavior independently of Ca(2+)activation, by simulation of flow-clamp experiments at constant Ca(2+)concentration. During the volume ramp, both reduced cross-bridge elongation and decreased concentration by cross-bridge detachment caused a fall of pressure; at end-ejection there was a fast partial increase of pressure by recovery of cross-bridge elongation, and during post-ejection there was a slower pressure change towards the value corresponding to end-ejection volume by cross-bridge reattachment according to the rate of constants of Ca(2+)kinetics. Likewise, during a physiological normal ejection, results showed that a maximal decrease in cross-bridge elongation (Deltah) produced a maximal reduction of ejecting pressure with respect to that at constant cross-bridge elongation (DeltaP), both in simulated beats (DeltaP=20%, Deltah=17%), and in experimentally fitted pressure-volume data from open-chest dogs (DeltaP=43.7+/-3.8%, Deltah=30.7+/-8.3%), Deltah being dependent of peak flow (Deltah=0. 1471 peak flow+6.0788, r=0.72). We conclude that normal ejecting pressure depends not only on cross-bridge concentration, but also on the elongation of its elastic structure, which reduces pressure according to flow.

  2. 23. East Tremont Avenue Bridge crossing NEC. West Farms, Bronx ...

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

    23. East Tremont Avenue Bridge crossing NEC. West Farms, Bronx Co., NY. Sec. 4207, MP 12.44. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  3. 26. VIEW OF THE PEDESTRIAN BRIDGE CROSSING GRAND CANAL AT ...

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

    26. VIEW OF THE PEDESTRIAN BRIDGE CROSSING GRAND CANAL AT 30TH STREET IN PHOENIX, LOOKING WEST, Photographer: Mark Durben, April 1989 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ

  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. Altered cross-bridge properties in skeletal muscle dystrophies

    PubMed Central

    Guellich, Aziz; Negroni, Elisa; Decostre, Valérie; Demoule, Alexandre; Coirault, Catherine

    2014-01-01

    Force and motion generated by skeletal muscle ultimately depends on the cyclical interaction of actin with myosin. This mechanical process is regulated by intracellular Ca2+ through the thin filament-associated regulatory proteins i.e.; troponins and tropomyosin. Muscular dystrophies are a group of heterogeneous genetic affections characterized by progressive degeneration and weakness of the skeletal muscle as a consequence of loss of muscle tissue which directly reduces the number of potential myosin cross-bridges involved in force production. Mutations in genes responsible for skeletal muscle dystrophies (MDs) have been shown to modify the function of contractile proteins and cross-bridge interactions. Altered gene expression or RNA splicing or post-translational modifications of contractile proteins such as those related to oxidative stress, may affect cross-bridge function by modifying key proteins of the excitation-contraction coupling. Micro-architectural change in myofilament is another mechanism of altered cross-bridge performance. In this review, we provide an overview about changes in cross-bridge performance in skeletal MDs and discuss their ultimate impacts on striated muscle function. PMID:25352808

  7. Altered cross-bridge properties in skeletal muscle dystrophies.

    PubMed

    Guellich, Aziz; Negroni, Elisa; Decostre, Valérie; Demoule, Alexandre; Coirault, Catherine

    2014-01-01

    Force and motion generated by skeletal muscle ultimately depends on the cyclical interaction of actin with myosin. This mechanical process is regulated by intracellular Ca(2+) through the thin filament-associated regulatory proteins i.e.; troponins and tropomyosin. Muscular dystrophies are a group of heterogeneous genetic affections characterized by progressive degeneration and weakness of the skeletal muscle as a consequence of loss of muscle tissue which directly reduces the number of potential myosin cross-bridges involved in force production. Mutations in genes responsible for skeletal muscle dystrophies (MDs) have been shown to modify the function of contractile proteins and cross-bridge interactions. Altered gene expression or RNA splicing or post-translational modifications of contractile proteins such as those related to oxidative stress, may affect cross-bridge function by modifying key proteins of the excitation-contraction coupling. Micro-architectural change in myofilament is another mechanism of altered cross-bridge performance. In this review, we provide an overview about changes in cross-bridge performance in skeletal MDs and discuss their ultimate impacts on striated muscle function.

  8. Contribution of arginine-glutamate salt bridges to helix stability.

    PubMed

    Walker, Kristin D; Causgrove, Timothy P

    2009-10-01

    Peptide side chain interactions were studied by molecular dynamics simulation using explicit solvent on a peptide with the sequence AAARAAAAEAAEAAAARA. Three different protonation states of the glutamic acid side chains were simulated for four 20 ns runs each, a total simulation time of 240 ns. Two different salt bridge geometries were observed and the preferred geometry was found to depend on Glu - Arg residue spacing. Stable charge clusters were also observed, particularly in the fully charged peptide. Salt bridges were selectively interrupted upon protonation, with concomitant changes in secondary structure. The fully charged peptide was highly helical between residues 9 and 13, although protonation increased helicity near the N-terminus. The contribution of salt bridges to helix stability therefore depends on both position and relative position of charged residues within a sequence.

  9. Cross-bridge scheme and force per cross-bridge state in skinned rabbit psoas muscle fibers.

    PubMed Central

    Kawai, M; Zhao, Y

    1993-01-01

    The rate and association constants (kinetic constants) which comprise a seven state cross-bridge scheme were deduced by sinusoidal analysis in chemically skinned rabbit psoas muscle fibers at 20 degrees C, 200 mM ionic strength, and during maximal Ca2+ activation (pCa 4.54-4.82). The kinetic constants were then used to calculate the steady state probability of cross-bridges in each state as the function of MgATP, MgADP, and phosphate (Pi) concentrations. This calculation showed that 72% of available cross-bridges were (strongly) attached during our control activation (5 mM MgATP, 8 mM Pi), which agreed approximately with the stiffness ratio (active:rigor, 69 +/- 3%); active stiffness was measured during the control activation, and rigor stiffness after an induction of the rigor state. By assuming that isometric tension is a linear combination of probabilities of cross-bridges in each state, and by measuring tension as the function of MgATP, MgADP, and Pi concentrations, we deduced the force associated with each cross-bridge state. Data from the osmotic compression of muscle fibers by dextran T500 were used to deduce the force associated with one of the cross-bridge states. Our results show that force is highest in the AM*ADP.Pi state (A = actin, M = myosin). Since the state which leads into the AM*ADP.Pi state is the weakly attached AM.ADP.Pi state, we confirm that the force development occurs on Pi isomerization (AM.ADP.Pi --> AM*ADP.Pi). Our results also show that a minimal force change occurs with the release of Pi or MgADP, and that force declines gradually with ADP isomerization (AM*ADP -->AM.ADP), ATP isomerization (AM+ATP-->AM*ATP), and with cross-bridge detachment. Force of the AM state agreed well with force measured after induction of the rigor state, indicating that the AM state is a close approximation of the rigor state. The stiffness results obtained as functions of MgATP, MgADP, and Pi concentrations were generally consistent with the cross-bridge

  10. 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

  11. 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

  12. Bridging Cultures: Evaluating Teachers' Understanding of Cross-Cultural Conflicts.

    ERIC Educational Resources Information Center

    Trumbull, Elise; Greenfield, Patricia; Quiroz, Blanca; Rothstein-Fisch, Carrie

    The Bridging Cultures Project is a collaboration among several researchers and teachers (n=8) to design professional development activities on the topic of cross-cultural understanding. During the fall of 1996, participating teachers will be given a pre-assessment and post-assessment. The assessments are designed to give some information on how…

  13. 25. VIEW OF McGREGOR BRIDGE (18811936), CROSSING THE MERRIMACK RIVER ...

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

    25. VIEW OF McGREGOR BRIDGE (1881-1936), CROSSING THE MERRIMACK RIVER AT BRIDGE STREET, LOOKING SOUTHEAST. NORTH ELEVATION OF DOUBLE-DECKED, THREE-SPAN DOUGLAS PATENT PARABOLIC IRON TRUSS ERECTED BY CORRUGATED METAL COMPANY (BERLIN IRON BRIDGE COMPANY, BERLIN, CT) From 'Bridge Street Bridge', photographer and date unknown. - Notre Dame Bridge, Spanning Merrimack River on Bridge Street, Manchester, Hillsborough County, NH

  14. Cross-bridge attachment during high-speed active shortening of skinned fibers of the rabbit psoas muscle: implications for cross-bridge action during maximum velocity of filament sliding.

    PubMed

    Stehle, R; Brenner, B

    2000-03-01

    To characterize the kinetics of cross-bridge attachment to actin during unloaded contraction (maximum velocity of filament sliding), ramp-shaped stretches with different stretch-velocities (2-40,000 nm per half-sarcomere per s) were applied to actively contracting skinned fibers of the rabbit psoas muscle. Apparent fiber stiffness observed during such stretches was plotted versus the speed of the imposed stretch (stiffness-speed relation) to derive the rate constants for cross-bridge dissociation from actin. The stiffness-speed relation obtained for unloaded shortening conditions was shifted by about two orders of magnitude to faster stretch velocities compared to isometric conditions and was almost identical to the stiffness-speed relation observed in the presence of MgATPgammaS at high Ca(2+) concentrations, i.e., under conditions where cross-bridges are weakly attached to the fully Ca(2+) activated thin filaments. These data together with several control experiments suggest that, in contrast to previous assumptions, most of the fiber stiffness observed during high-speed shortening results from weak cross-bridge attachment to actin. The fraction of strongly attached cross-bridges during unloaded shortening appears to be as low as some 1-5% of the fraction present during isometric contraction. This is about an order of magnitude less than previous estimates in which contribution of weak cross-bridge attachment to observed fiber stiffness was not considered. Our findings imply that 1) the interaction distance of strongly attached cross-bridges during high-speed shortening is well within the range consistent with conventional cross-bridge models, i.e., that no repetitive power strokes need to be assumed, and 2) that a significant part of the negative forces that limit the maximum speed of filament sliding might originate from weak cross-bridge interactions with actin.

  15. Stretch activation and nonlinear elasticity of muscle cross-bridges.

    PubMed Central

    Thomas, N; Thornhill, R A

    1996-01-01

    When active insect fibrillar flight muscle is stretched, its ATPase rate increases and it develops "negative viscosity," which allows it to perform oscillatory work. We use a six-state model for the cross-bridge cycle to show that such "stretch activation" may arise naturally as a nonlinear property of a cross-bridge interacting with a single attachment site on a thin filament. Attachment is treated as a thermally activated process in which elastic energy must be supplied to stretch or compress the cross-bridge spring. We find that stretch activation occurs at filament displacements where, before the power stroke, the spring is initially in compression rather than in tension. In that case, pulling the filaments relieves the initial compression and reduces the elastic energy required for attachment. The result is that the attachment rate is enhanced by stretching. The model also displays the "delayed tension" effect observed in length-step experiments. When the muscle is stretched suddenly, the power stroke responds very quickly, but there is a time lag before dissociation at the end of the cycle catches up with the increased attachment rate. This lag is responsible for the delayed tension and hence also for the negative viscosity. PMID:8744318

  16. Sympathetic nerves bridge the cross-transmission in hemifacial spasm.

    PubMed

    Zheng, Xuesheng; Hong, Wenyao; Tang, Yinda; Wu, Zhenghai; Shang, Ming; Zhang, Wenchuan; Zhong, Jun; Li, Shiting

    2012-05-23

    The pathophysiologic basis of hemifacial spasm is abnormal cross-transmission between facial nerve fibers. The author hypothesized that the demyelinated facial nerve fibers were connected with the sympathetic nerve fibers on the offending artery wall, and thus the latter function as a bridge in the cross-transmission circuit. This hypothesis was tested using a rat model of hemifacial spasm. A facial muscle response was recorded while the offending artery wall was electrically stimulated. The nerve fibers on the offending artery wall were blocked with lidocaine, or the superior cervical ganglion, which innervates the offending artery, was resected, and meanwhile the abnormal muscle response was monitored and analyzed. A waveform was recorded from the facial muscle when the offending artery wall was stimulated, named as "Z-L response". The latency of Z-L response was different from that of abnormal muscle response. When the nerve fibers on the offending artery wall were blocked by lidocaine, the abnormal muscle response disappeared gradually and recovered in 2h. The abnormal muscle response disappeared permanently after the sympathetic ganglion was resected. Our findings indicate that cross-transmission between the facial nerve fibers is bridged by the nerve fibers on the offending artery wall, probably sympathetic nerve fibers.

  17. 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.

  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.

  19. 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

  20. 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.

  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. Surviving track through Bridge No. 1601, Third B&O Crossing, looking ...

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

    Surviving track through Bridge No. 1601, Third B&O Crossing, looking west. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  3. Bridge No. 1601, Third B&O Crossing, over CSX (former B&O) ...

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

    Bridge No. 1601, Third B&O Crossing, over CSX (former B&O) tracks and North Branch Road, looking northwest. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  4. 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

  5. Cross-bridge properties in single intact frog fibers studied by fast stretches.

    PubMed

    Colombini, Barbara; Nocella, Marta; Benelli, Giulia; Cecchi, Giovanni; Bagni, M Angela

    2010-01-01

    Cross-bridges properties were measured under different experimental conditions by applying fast stretches to activated skeletal frog muscle fiber to -forcibly detach the cross-bridge ensemble. This allowed to measure the tension needed to detach the cross-bridges, P(c), and the sarcomere elongation at the rupture force, L(c). These two parameters are expected to be correlated with cross-bridges number (P(c)) and their mean extension (L(c)). Conditions investigated were: tetanus rise and plateau under normal Ringer and Ringer containing different BDM -concentrations, hyper (1.4T) and hypotonic (0.8T) solutions, 5 and 14 degrees C temperature. P(c) was linearly correlated with the tension (P) developed by the fibers under all the conditions examined, however the ratio P(c)/P changed depending on conditions being greater at low temperature and higher tonicity. These results indicate that, (a) P(c) can be used as a measure of attached cross-bridge number and (b) the force developed by the individual cross-bridge increases at high temperature and low tonicity. L(c) was not affected by tension developed, however it changed under different conditions, being greater at low temperature and high tonicity. These findings, suggests, in agreement with P(c) data, that cross-bridge extension is smaller at low temperature and high tonicity. By comparing these data with tetanic tension we concluded that potentiation or depression induced on tetanic force by tonicity or temperature changes are entirely accounted for by changes of the force developed by the individual cross-bridge.

  6. Axial and radial forces of cross-bridges depend on lattice spacing.

    PubMed

    Williams, C David; Regnier, Michael; Daniel, Thomas L

    2010-12-02

    Nearly all mechanochemical models of the cross-bridge treat myosin as a simple linear spring arranged parallel to the contractile filaments. These single-spring models cannot account for the radial force that muscle generates (orthogonal to the long axis of the myofilaments) or the effects of changes in filament lattice spacing. We describe a more complex myosin cross-bridge model that uses multiple springs to replicate myosin's force-generating power stroke and account for the effects of lattice spacing and radial force. The four springs which comprise this model (the 4sXB) correspond to the mechanically relevant portions of myosin's structure. As occurs in vivo, the 4sXB's state-transition kinetics and force-production dynamics vary with lattice spacing. Additionally, we describe a simpler two-spring cross-bridge (2sXB) model which produces results similar to those of the 4sXB model. Unlike the 4sXB model, the 2sXB model requires no iterative techniques, making it more computationally efficient. The rate at which both multi-spring cross-bridges bind and generate force decreases as lattice spacing grows. The axial force generated by each cross-bridge as it undergoes a power stroke increases as lattice spacing grows. The radial force that a cross-bridge produces as it undergoes a power stroke varies from expansive to compressive as lattice spacing increases. Importantly, these results mirror those for intact, contracting muscle force production.

  7. Three Bridge Fryer's Ford Bridge, Nimrod Bridge, and Ward's ...

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

    Three Bridge - Fryer's Ford Bridge, Nimrod Bridge, and Ward's Crossing Bridge - Fryer's Ford Bridge, Spanning East Fork of Point Remove Creek at Fryer Bridge Road (CR 67), Solgohachia, Conway County, AR

  8. Formation of lamellar cross bridges in the annulus fibrosus of the intervertebral disc is a consequence of vascular regression.

    PubMed

    Smith, Lachlan J; Elliott, Dawn M

    2011-05-01

    Cross bridges are radial structures within the highly organized lamellar structure of the annulus fibrosus of the intervertebral disc that connect two or more non-consecutive lamellae. Their origin and function are unknown. During fetal development, blood vessels penetrate deep within the AF and recede during postnatal growth. We hypothesized that cross bridges are the pathways left by these receding blood vessels. Initially, the presence of cross bridges was confirmed in cadaveric human discs aged 25 and 53 years. Next, L1-L2 intervertebral discs (n=4) from sheep ranging in age from 75 days fetal gestation to adult were processed for paraffin histology. Mid-sagittal sections were immunostained for endothelial cell marker PECAM-1. The anterior and posterior AF were imaged using differential interference contrast microscopy, and the following parameters were quantified: total number of distinct lamellae, total number of cross bridges, percentage of cross bridges staining positive for PECAM-1, cross bridge penetration depth (% total lamellae), and PECAM-1 positive cross bridge penetration depth. Cross bridges were first observed at 100 days fetal gestation. The overall number peaked in neonates then remained relatively unchanged. The percentage of PECAM-1 positive cross bridges declined progressively from almost 100% at 100 days gestation to less than 10% in adults. Cross bridge penetration depth peaked in neonates then remained unchanged at subsequent ages. Depth of PECAM-1 positive cross bridges decreased progressively after birth. Findings were similar for both the anterior and posterior. The AF lamellar architecture is established early in development. It later becomes disrupted as a consequence of vascularization. Blood vessels then recede, perhaps due to increasing mechanical stresses in the surrounding matrix. In this study we present evidence that the pathways left by receding blood vessels remain as lamellar cross bridges. It is unclear whether the presence

  9. 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.

  10. Nerve Cross-Bridging to Enhance Nerve Regeneration in a Rat Model of Delayed Nerve Repair

    PubMed Central

    2015-01-01

    There are currently no available options to promote nerve regeneration through chronically denervated distal nerve stumps. Here we used a rat model of delayed nerve repair asking of prior insertion of side-to-side cross-bridges between a donor tibial (TIB) nerve and a recipient denervated common peroneal (CP) nerve stump ameliorates poor nerve regeneration. First, numbers of retrogradely-labelled TIB neurons that grew axons into the nerve stump within three months, increased with the size of the perineurial windows opened in the TIB and CP nerves. Equal numbers of donor TIB axons regenerated into CP stumps either side of the cross-bridges, not being affected by target neurotrophic effects, or by removing the perineurium to insert 5-9 cross-bridges. Second, CP nerve stumps were coapted three months after inserting 0-9 cross-bridges and the number of 1) CP neurons that regenerated their axons within three months or 2) CP motor nerves that reinnervated the extensor digitorum longus (EDL) muscle within five months was determined by counting and motor unit number estimation (MUNE), respectively. We found that three but not more cross-bridges promoted the regeneration of axons and reinnervation of EDL muscle by all the CP motoneurons as compared to only 33% regenerating their axons when no cross-bridges were inserted. The same 3-fold increase in sensory nerve regeneration was found. In conclusion, side-to-side cross-bridges ameliorate poor regeneration after delayed nerve repair possibly by sustaining the growth-permissive state of denervated nerve stumps. Such autografts may be used in human repair surgery to improve outcomes after unavoidable delays. PMID:26016986

  11. 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.

  12. 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

  13. Cross-bridge kinetics in rat myocardium: effect of sarcomere length and calcium activation.

    PubMed

    Wannenburg, T; Heijne, G H; Geerdink, J H; Van Den Dool, H W; Janssen, P M; De Tombe, P P

    2000-08-01

    We tested the hypotheses that Ca(2+) concentration ([Ca(2+)]) and sarcomere length (SL) modulate force development via graded effects on cross-bridge kinetics in chemically permeabilized rat cardiac trabeculae. Using sinusoidal length perturbations, we derived the transfer functions of stiffness over a range of [Ca(2+)] at a constant SL of 2.1 micrometer (n = 8) and at SL of 2.0, 2.1, and 2.2 micrometer (n = 4). We found that changes in SL affected only the magnitude of stiffness, whereas [Ca(2+)] affected the magnitude and phase-frequency relations. The data were fit to complex functions of two exponential processes. The characteristic frequencies (b and c) of these processes are indexes of cross-bridge kinetics, with b relating to cross-bridge attachment to and c to detachment from certain non-force-generating states. Both were significantly affected by [Ca(2+)], with an increase in b and c of 140 and 44%, respectively, over the range of [Ca(2+)] studied (P < 0.01). In contrast, SL had no effect on the characteristic frequencies (P > 0.6). We conclude that Ca(2+) activation modulates force development in rat myocardium, at least in part, via a graded effect on cross-bridge kinetics, whereas SL effects are mediated mainly by recruitment of cross bridges.

  14. Triangles bridge the scales: Quantifying cellular contributions to tissue deformation

    NASA Astrophysics Data System (ADS)

    Merkel, Matthias; Etournay, Raphaël; Popović, Marko; Salbreux, Guillaume; Eaton, Suzanne; Jülicher, Frank

    2017-03-01

    In this article, we propose a general framework to study the dynamics and topology of cellular networks that capture the geometry of cell packings in two-dimensional tissues. Such epithelia undergo large-scale deformation during morphogenesis of a multicellular organism. Large-scale deformations emerge from many individual cellular events such as cell shape changes, cell rearrangements, cell divisions, and cell extrusions. Using a triangle-based representation of cellular network geometry, we obtain an exact decomposition of large-scale material deformation. Interestingly, our approach reveals contributions of correlations between cellular rotations and elongation as well as cellular growth and elongation to tissue deformation. Using this triangle method, we discuss tissue remodeling in the developing pupal wing of the fly Drosophila melanogaster.

  15. Extraction of cross-sea bridges from GF-2 PMS satellite images using mathematical morphology

    NASA Astrophysics Data System (ADS)

    Chen, Chao; Sui, Xinxin; Zhen, Guangwei; Guo, Biyun; Chen, Xiaowei

    2016-11-01

    Cross-sea bridges are typical target of natural sceneries. Extracting cross-sea bridges from remote sensing images appears significant. In this study, for the complexity of ground objects in GF-2 PMS satellite images, we have selected direction-augmented linear structuring elements to be used for extraction of cross-sea bridges. Firstly, pre-processing of original image has been carried out; secondly, calculate NDVI and extract water bodies; thirdly, according to the direction of water bodies, select appropriate direction-augmented linear structuring elements, proceed mathematical morphology operations on the water bodies, and assisted by prior knowledge of the bridge, extract the bridge object; finally, select an experimental area to verify the effectiveness and applicability of the method. Our work shows that the direction-augmented linear structuring elements are effective and efficient for extraction of bridges with different directions in GF-2 PMS satellite images, and the approach in this study is important to expand the application areas of domestic high-resolution remote sensing images.

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

    PubMed Central

    Bershitsky, S Y; Tsaturyan, A K

    1995-01-01

    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

  17. Bridge No. 1601, Third B&O Crossing, over CSX tracks in ...

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

    Bridge No. 1601, Third B&O Crossing, over CSX tracks in North Branch, Maryland, looking northwest. The Pittsburgh Plate Glass Plant can be seen in the background. NPS property boundary is out of view at lower right. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  18. 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…

  19. Structural features of cross-bridges in isometrically contracting skeletal muscle.

    PubMed

    Kraft, Theresia; Mattei, Thomas; Radocaj, Ante; Piep, Birgit; Nocula, Christoph; Furch, Markus; Brenner, Bernhard

    2002-05-01

    Two-dimensional x-ray diffraction was used to investigate structural features of cross-bridges that generate force in isometrically contracting skeletal muscle. Diffraction patterns were recorded from arrays of single, chemically skinned rabbit psoas muscle fibers during isometric force generation, under relaxation, and in rigor. In isometric contraction, a rather prominent intensification of the actin layer lines at 5.9 and 5.1 nm and of the first actin layer line at 37 nm was found compared with those under relaxing conditions. Surprisingly, during isometric contraction, the intensity profile of the 5.9-nm actin layer line was shifted toward the meridian, but the resulting intensity profile was different from that observed in rigor. We particularly addressed the question whether the differences seen between rigor and active contraction might be due to a rigor-like configuration of both myosin heads in the absence of nucleotide (rigor), whereas during active contraction only one head of each myosin molecule is in a rigor-like configuration and the second head is weakly bound. To investigate this question, we created different mixtures of weak binding myosin heads and rigor-like actomyosin complexes by titrating MgATPgammaS at saturating [Ca2+] into arrays of single muscle fibers. The resulting diffraction patterns were different in several respects from patterns recorded under isometric contraction, particularly in the intensity distribution along the 5.9-nm actin layer line. This result indicates that cross-bridges present during isometric force generation are not simply a mixture of weakly bound and single-headed rigor-like complexes but are rather distinctly different from the rigor-like cross-bridge. Experiments with myosin-S1 and truncated S1 (motor domain) support the idea that for a force generating cross-bridge, disorder due to elastic distortion might involve a larger part of the myosin head than for a nucleotide free, rigor cross-bridge.

  20. Mutation of the myosin converter domain alters cross-bridge elasticity.

    PubMed

    Köhler, Jan; Winkler, Gerhard; Schulte, Imke; Scholz, Tim; McKenna, William; Brenner, Bernhard; Kraft, Theresia

    2002-03-19

    Elastic distortion of a structural element of the actomyosin complex is fundamental to the ability of myosin to generate motile forces. An elastic element allows strain to develop within the actomyosin complex (cross-bridge) before movement. Relief of this strain then drives filament sliding, or more generally, movement of a cargo. Even with the known crystal structure of the myosin head, however, the structural element of the actomyosin complex in which elastic distortion occurs remained unclear. To assign functional relevance to various structural elements of the myosin head, e.g., to identify the elastic element within the cross-bridge, we studied mechanical properties of muscle fibers from patients with familial hypertrophic cardiomyopathy with point mutations in the head domain of the beta-myosin heavy chain. We found that the Arg-719 --> Trp (Arg719Trp) mutation, which is located in the converter domain of the myosin head fragment, causes an increase in force generation and fiber stiffness under isometric conditions by 48-59%. Under rigor and relaxing conditions, fiber stiffness was 45-47% higher than in control fibers. Yet, kinetics of active cross-bridge cycling were unchanged. These findings, especially the increase in fiber stiffness under rigor conditions, indicate that cross-bridges with the Arg719Trp mutation are more resistant to elastic distortion. The data presented here strongly suggest that the converter domain that forms the junction between the catalytic and the light-chain-binding domain of the myosin head is not only essential for elastic distortion of the cross-bridge, but that the main elastic distortion may even occur within the converter domain itself.

  1. Skeletal muscle myosin cross-bridge cycling is necessary for myofibrillogenesis.

    PubMed

    Ramachandran, Indu; Terry, Monica; Ferrari, Michael B

    2003-05-01

    A major stimulus affecting myofibrillogenesis in both embryonic and mature striated muscle is contractile activity. There are two major signals associated with contractile activity: a physiological signal, the transient increase in intracellular calcium, and a physical signal, the transient increase in tension production. However, dissociating these two signals to examine their relative contributions to myofibrillogenesis has proven difficult. In this study, we have used two different myosin inhibitors to determine the importance of myosin cross-bridge cycling in sarcomere assembly. We find that the small-molecule inhibitor 2,3-butanedione monoxime (BDM), which inhibits myosin ATPase, disrupts myofibrillogenesis in amphibian myocytes, consistent with results from avian studies. However, BDM is a weak myosin inhibitor and it is non-specific; concentrations that inhibit contraction and disrupt myofibrillogenesis also disrupt calcium signaling. Therefore, we also used the recently identified skeletal muscle myosin II inhibitor, N-benzyl-p-toluenesulphonamide (BTS), which has high affinity and specificity for skeletal muscle fast myosin. BTS inhibits contraction and results in myofibrillar disruption that phenocopies our results with BDM. However, BTS does not affect either spontaneous or induced calcium transients. Furthermore, BTS is reversible and does not significantly affect the expression levels of myosin or actin. Thus, our convergent results with BDM and BTS suggest that sarcomere assembly depends on active regulation of tension in the forming myofibril.

  2. Level II scour analysis for Bridge 43 (SPRICYBRIG0043) on Bridge Street, crossing the Black River, Springfield, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Medalie, Laura

    1997-01-01

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

    PubMed

    Yin, Xin; Hu, Die; 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.

  4. Three dimensional mesoscale analysis of translamellar cross-bridge morphologies in the annulus fibrosus using optical coherence tomography.

    PubMed

    Han, Sang Kuy; Chen, Chao-Wei; Wierwille, Jerry; Chen, Yu; Hsieh, Adam H

    2015-03-01

    The defining characteristic of the annulus fibrosus (AF) of the intervertebral disc (IVD) has long been the lamellar structures that consist of highly ordered collagen fibers arranged in alternating oblique angles from one layer to the next. However, a series of recent histologic studies have demonstrated that AF lamellae contain elastin- and type VI collagen-rich secondary "cross-bridge" structures across lamellae. In this study, we use optical coherence tomography (OCT) to elucidate the three-dimensional (3-D) morphologies of these translamellar cross-bridges in AF tissues. Mesoscale volumetric images by OCT revealed a 3-D network of heterogeneously distributed cross-bridges. The results of this study confirm the translamellar cross-bridge is identifiable as a distinguishable structure, which lies in the interbundle space of adjacent lamellae and crisscrosses multiple lamellae in the radial direction. In contrast to previously proposed models extrapolated from 2-D sections, results from this current study show that translamellar cross-bridges exist as a complex, interconnected network. We also found much greater variation in lengths of cross-bridges within the interbundle space of lamellae (0.8-1.4 mm from the current study versus 0.3-0.6 mm from 2-D sections). OCT-based 3-D morphology of translamellar cross-bridge provides novel insight into the AF structure.

  5. 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.

  6. Effect of muscle length on cross-bridge kinetics in intact cardiac trabeculae at body temperature.

    PubMed

    Milani-Nejad, Nima; Xu, Ying; Davis, Jonathan P; Campbell, Kenneth S; Janssen, Paul M L

    2013-01-01

    Dynamic force generation in cardiac muscle, which determines cardiac pumping activity, depends on both the number of sarcomeric cross-bridges and on their cycling kinetics. The Frank-Starling mechanism dictates that cardiac force development increases with increasing cardiac muscle length (corresponding to increased ventricular volume). It is, however, unclear to what extent this increase in cardiac muscle length affects the rate of cross-bridge cycling. Previous studies using permeabilized cardiac preparations, sub-physiological temperatures, or both have obtained conflicting results. Here, we developed a protocol that allowed us to reliably and reproducibly measure the rate of tension redevelopment (k(tr); which depends on the rate of cross-bridge cycling) in intact trabeculae at body temperature. Using K(+) contractures to induce a tonic level of force, we showed the k(tr) was slower in rabbit muscle (which contains predominantly β myosin) than in rat muscle (which contains predominantly α myosin). Analyses of k(tr) in rat muscle at optimal length (L(opt)) and 90% of optimal length (L(90)) revealed that k(tr) was significantly slower at L(opt) (27.7 ± 3.3 and 27.8 ± 3.0 s(-1) in duplicate analyses) than at L(90) (45.1 ± 7.6 and 47.5 ± 9.2 s(-1)). We therefore show that k(tr) can be measured in intact rat and rabbit cardiac trabeculae, and that the k(tr) decreases when muscles are stretched to their optimal length under near-physiological conditions, indicating that the Frank-Starling mechanism not only increases force but also affects cross-bridge cycling kinetics.

  7. 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.

  8. State-dependent radial elasticity of attached cross-bridges in single skinned fibres of rabbit psoas muscle.

    PubMed Central

    Xu, S; Brenner, B; Yu, L C

    1993-01-01

    1. In a single skinned fibre of rabbit psoas muscle, upon attachment of cross bridges to actin in the presence of ADP or pyrophosphate (PPi), the separation between the contractile filaments, as determined by equatorial X-ray diffraction, is found to decrease, suggesting that force is generated in the radial direction. 2. The single muscle fibres were subjected to compression by 0-8% of dextran T500. The changes in lattice spacings by dextran compression were compared with changes induced by cross-bridge attachment to actin. Based on this comparison, the magnitude and the direction of the radial force generated by the attached cross-bridges were estimated. The radial cross-bridge force varied with filament separation, and the magnitude of the radial cross-bridge force reached as high as the maximal axial force produced during isometric contraction. 3. One key parameter of the radial elasticity, i.e. the equilibrium spacing where the radial force is zero, was found to depend on the ligand bound to the myosin head. In the presence of ADP, the equilibrium spacing was 36 nm. In the presence of MgPPi the equilibrium spacing shifted to 35 nm and Ca2+ had little effect on the equilibrium spacing. 4. The equilibrium spacing was independent of the fraction of cross-bridges attached to actin. The fraction of cross-bridges attached in rigor was modulated from 100% to close to 0% by adding up to 10 mM of ATP gamma S in the rigor solution. The lattice spacing remained at 38 nm, the equilibrium spacing for nucleotide-free cross-bridges at mu = 170 mM. 5. Radial force generated by cross-bridges in rigor at large lattice spacings (38 nm < or = d10 < or = 46 nm) appeared to vary linearly with lattice spacing. 6. The titration of ATP gamma S to fibres in rigor provided a correlation between the radial stiffness of the nucleotide-free cross-bridges and the equatorial intensities. The relation between the equatorial intensity ratio I11/I10 and radial stiffness appeared to be

  9. The Frank-Starling mechanism involves deceleration of cross-bridge kinetics and is preserved in failing human right ventricular myocardium

    PubMed Central

    Milani-Nejad, Nima; Canan, Benjamin D.; Elnakish, Mohammad T.; Davis, Jonathan P.; Chung, Jae-Hoon; Fedorov, Vadim V.; Binkley, Philip F.; Higgins, Robert S. D.; Kilic, Ahmet; Mohler, Peter J.

    2015-01-01

    Cross-bridge cycling rate is an important determinant of cardiac output, and its alteration can potentially contribute to reduced output in heart failure patients. Additionally, animal studies suggest that this rate can be regulated by muscle length. The purpose of this study was to investigate cross-bridge cycling rate and its regulation by muscle length under near-physiological conditions in intact right ventricular muscles of nonfailing and failing human hearts. We acquired freshly explanted nonfailing (n = 9) and failing (n = 10) human hearts. All experiments were performed on intact right ventricular cardiac trabeculae (n = 40) at physiological temperature and near the normal heart rate range. The failing myocardium showed the typical heart failure phenotype: a negative force-frequency relationship and β-adrenergic desensitization (P < 0.05), indicating the expected pathological myocardium in the right ventricles. We found that there exists a length-dependent regulation of cross-bridge cycling kinetics in human myocardium. Decreasing muscle length accelerated the rate of cross-bridge reattachment (ktr) in both nonfailing and failing myocardium (P < 0.05) equally; there were no major differences between nonfailing and failing myocardium at each respective length (P > 0.05), indicating that this regulatory mechanism is preserved in heart failure. Length-dependent assessment of twitch kinetics mirrored these findings; normalized dF/dt slowed down with increasing length of the muscle and was virtually identical in diseased tissue. This study shows for the first time that muscle length regulates cross-bridge kinetics in human myocardium under near-physiological conditions and that those kinetics are preserved in the right ventricular tissues of heart failure patients. PMID:26453335

  10. The Frank-Starling mechanism involves deceleration of cross-bridge kinetics and is preserved in failing human right ventricular myocardium.

    PubMed

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

    2015-12-15

    Cross-bridge cycling rate is an important determinant of cardiac output, and its alteration can potentially contribute to reduced output in heart failure patients. Additionally, animal studies suggest that this rate can be regulated by muscle length. The purpose of this study was to investigate cross-bridge cycling rate and its regulation by muscle length under near-physiological conditions in intact right ventricular muscles of nonfailing and failing human hearts. We acquired freshly explanted nonfailing (n = 9) and failing (n = 10) human hearts. All experiments were performed on intact right ventricular cardiac trabeculae (n = 40) at physiological temperature and near the normal heart rate range. The failing myocardium showed the typical heart failure phenotype: a negative force-frequency relationship and β-adrenergic desensitization (P < 0.05), indicating the expected pathological myocardium in the right ventricles. We found that there exists a length-dependent regulation of cross-bridge cycling kinetics in human myocardium. Decreasing muscle length accelerated the rate of cross-bridge reattachment (ktr) in both nonfailing and failing myocardium (P < 0.05) equally; there were no major differences between nonfailing and failing myocardium at each respective length (P > 0.05), indicating that this regulatory mechanism is preserved in heart failure. Length-dependent assessment of twitch kinetics mirrored these findings; normalized dF/dt slowed down with increasing length of the muscle and was virtually identical in diseased tissue. This study shows for the first time that muscle length regulates cross-bridge kinetics in human myocardium under near-physiological conditions and that those kinetics are preserved in the right ventricular tissues of heart failure patients.

  11. 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

  12. 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.

  13. 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…

  14. Analysis of the structure factor of dense krypton gas: Bridge contributions and many-body effects

    NASA Astrophysics Data System (ADS)

    Aers, G. C.; Dharma-Wardana, M. W. C.

    1984-05-01

    The pair-correlation function g(r) of the Kr-type model fluid with only pair interactions was calculated using the Rosenfeld-Ashcroft modification of the hypernetted-chain (HNC) equation which includes bridge diagrams, and gave results in excellent agreement with Monte Carlo g(r) data. These bridge functions and the known pair potential were used to analyze the neutron-diffraction structure-factor data of Teitsma and Egelstaff, to determine the effective strength of the three-body potential as a function of the density assuming it to be of the Axilrod-Teller (AT) form. The strength of the effective three-body contribution s=ννtheor, where νtheor is the theoretical value, decreases for higher densities, suggesting that the many-body terms (beyond the Axilrod-Teller form) screen the AT interaction as the density increases. The results are very sensitive to the uncertainties in the structure factor S(k) for small k if parameter optimization is used to determine the effective pair potential. However, prediction of the compressibility using s=1 allows us to conclude that νtheor is consistent with the experimental data for low densities, to within the uncertainties in the presently available pair potentials and in the structure-factor data.

  15. Cross bridge-dependent activation of contraction in cardiac myofibrils at low pH.

    PubMed

    Swartz, D R; Zhang, D; Yancey, K W

    1999-05-01

    Striated muscle contracts in the absence of calcium at low concentrations of MgATP ([MgATP]), and this has been termed rigor activation because rigor cross bridges attach and activate adjacent actin sites. This process is well characterized in skeletal muscle but not in cardiac muscle. Rigor cross bridges are also thought to increase calcium binding to troponin C and play a synergistic role in activation. We tested the hypothesis that cross bridge-dependent activation results in an increase in contractile activity at normal and low pH values. Myofibrillar ATPase activity was measured as a function of pCa and [MgATP] at pH 7.0, and the data showed that, at pCa values of >/=5.5, there was a biphasic relationship between activity and [MgATP]. Peak activity occurred at 10-50 microM MgATP, and [MgATP] for peak activity was lower with increased pCa. The ATPase activity of rat cardiac myofibrils as a function of [MgATP] at a pCa of 9.0 was measured at several pH levels (pH 5.4-7.0). The ATPase activity as a function of [MgATP] was biphasic with a maximum at 8-10 microM MgATP. Lower pH did not result in a substantial decrease in myofibrillar ATPase activity even at pH 5.4. The extent of shortening, as measured by Z-line spacing, was greatest at 8 microM MgATP and less at both lower and higher [MgATP], and this response was observed at all pH levels. These studies suggest that the peak ATPase activity associated with low [MgATP] was coupled to sarcomere shortening. These results support the hypothesis that cross bridge-dependent activation of contraction may be responsible for contracture in the ischemic heart.

  16. Level II scour analysis for Bridge 45 (CHELTH00440045) on Town Highway 44, crossing first Branch White River, Chelsea, Vermont

    USGS Publications Warehouse

    Ayotte, Joseph D.; Hammond, Robert E.

    1996-01-01

    bridge consisting of one 27-foot clear-span concrete-encased steel beam deck superstructure (Vermont Agency of Transportation, written commun., August 25, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is 5 degrees. Both abutment footings were reported as exposed and the left abutment was reported to be undermined by 0.5 ft at the time of the Level I assessment. The only scour protection measure at the site was type-1 stone fill (less than 12 inches diameter) along the left abutment which was reported as failed. 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 0.4 to 5.1 ft. with the worst-case occurring at the 500-year discharge. Abutment scour ranged from 9.9 to 20.3 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

  17. Direct tests of muscle cross-bridge theories: predictions of a Brownian dumbbell model for position-dependent cross-bridge lifetimes and step sizes with an optically trapped actin filament.

    PubMed Central

    Smith, D A

    1998-01-01

    Force and displacement events from a single myosin molecule interacting with an actin filament suspended between optically trapped beads (Finer, J. T., R. M. Simmons, and J. A. Spudich. 1994. Nature. 368:113-119) can be interpreted in terms of a generalized cross-bridge model that includes the effects of Brownian forces on the beads. Steady-state distributions of force and displacement can be obtained directly from a generalized Smoluchowski equation for Brownian motion of the actin-bead "dumbbell," and time series from Monte Carlo simulations of the corresponding Langevin equation. When the frequency spectrum of Brownian motion extends beyond cross-bridge transition rates, the inverse mean lifetimes of force/displacement pulses are given by cross-bridge rate constants averaged over a Boltzmann distribution of Brownian noise. These averaged rate constants reflect the strain-dependence of the rate constants for the stationary filament, most faithfully at high trap stiffness. Hence, measurements of the lifetimes and displacements of single events as a function of the resting position of the dumbbell can provide a direct test of different cross-bridge theories of muscle contraction. Quantitative demonstrations are given for Huxley models with 1) faster binding or 2) slower dissociation at positive cross-bridge strain. Predictions for other models can be inferred from the averaging procedure. PMID:9826619

  18. Crystal structures of two cross-bridged chromium(III) tetra­aza­macrocycles

    PubMed Central

    Prior, Timothy J.; Maples, Danny L.; Maples, Randall D.; Hoffert, Wesley A.; Parsell, Trenton H.; Silversides, Jon D.; Archibald, Stephen J.; Hubin, Timothy J.

    2014-01-01

    The crystal structure of di­chlorido­(4,10-dimethyl-1,4,7,10-tetra­aza­bicyclo­[5.5.2]tetra­deca­ne)chromium(III) hexa­fluorido­phosphate, [CrCl2(C12H26N4)]PF6, (I), has monoclinic symmetry (space group P21/n) at 150 K. The structure of the related di­chlorido­(4,11-dimethyl-1,4,8,11-tetra­aza­bicyclo­[6.6.2]hexa­deca­ne)chromium(III) hexa­fluorido­phosphate, [CrCl2(C14H30N4)]PF6, (II), also displays monoclinic symmetry (space group P21/c) at 150 K. In each case, the CrIII ion is hexa­coordinate with two cis chloride ions and two non-adjacent N atoms bound cis equatorially and the other two non-adjacent N atoms bound trans axially in a cis-V conformation of the macrocycle. The extent of the distortion from the preferred octa­hedral coordination geometry of the CrIII ion is determined by the parent macrocycle ring size, with the larger cross-bridged cyclam ring in (II) better able to accommodate this preference and the smaller cross-bridged cyclen ring in (I) requiring more distortion away from octa­hedral geometry. PMID:25309165

  19. Effect of length oscillations on airway smooth muscle reactivity and cross-bridge cycling.

    PubMed

    Al-Jumaily, Ahmed M; Mbikou, Prisca; Redey, Prachi R

    2012-08-15

    Excessive airway narrowing due to airway smooth muscle (ASM) hyperconstriction is a major symptom in many respiratory diseases. In vitro imposition of length oscillations similar to those produced by tidal breathing on contracted ASM have shown to reduce muscle active forces, which is usually attributed to unconfirmed disruption of actomyosin cross-bridges. This research focuses on an in vitro investigation of the effect of mechanical oscillations on ASM reactivity and actomyosin cross-bridges. A computerized organ bath system was used to test maximally precontracted bovine ASM subjected to length oscillations at frequencies in the range of 10-100 Hz superimposed on tidal breathing oscillation. Using an immunofluorescence technique, two specific antibodies against the phospho-serine19 myosin light chain and the α-smooth muscle actin were used to analyze the colocalization between these two filaments. Data were processed using the plug-in "colocalization threshold" of ImageJ 1.43m software. The results demonstrate that both tidal and superimposed length oscillations reduce the active force in contracted ASM for a relatively long term and that the latter enhances the force reduction of the former. This reduction was also found to be frequency and time dependent. Additionally colocalization analysis indicates that length oscillations cause the detachment of the actomyosin connections and that this condition is sustained even after the cessation of the length oscillations.

  20. Cooperative Effects of Rigor and Cycling Cross-Bridges on Calcium Binding to Troponin C

    PubMed Central

    Cantino, Marie E.; Quintanilla, Abraham

    2007-01-01

    The effects of rigor and cycling cross-bridges on distributions of calcium (Ca) bound within sarcomeres of rabbit psoas muscle fibers were compared using electron probe x-ray microanalysis. Calcium in the overlap region of rigor fibers, after correction for that bound to thick filaments, was significantly higher than in the I-band at all pCa levels tested between 6.9 and 4.8, but the difference was greatest at pCa 6.9. With addition of MgATP, differences were significant at high levels of activation (pCa 5.6 and 4.9); near and below the threshold for activation, Ca was the same in I-band and overlap regions. Comparison of Ca and mass profiles at the A-I junction showed elevation of Ca extending 55–110 nm (up to three regulatory units) into the I-band. Extraction of TnC-reduced I-band and overlap Ca in rigor fibers at pCa 5.6 to the same levels found in unextracted fibers at pCa 8.9, suggesting that variations reported here reflect changes in Ca bound to troponin C (TnC). Taken together, these observations provide evidence for near-neighbor cooperative effects of both rigor and cycling cross-bridges on Ca2+ binding to TnC. PMID:17056730

  1. Synthesis and antimalarial activity of metal complexes of cross-bridged tetraazamacrocyclic ligands

    PubMed Central

    Hubin, Timothy J.; Amoyaw, Prince N. -A.; Roewe, Kimberly D.; Simpson, Natalie C.; Maples, Randall D.; Carder Freeman, TaRynn N.; Cain, Amy N.; Le, Justin G.; Archibald, Stephen J.; Khan, Shabana I.; Tekwani, Babu L.; Khan, M. O. Faruk

    2014-01-01

    Using transition metals such as manganese(II), iron(II), cobalt(II), nickel(II), copper(II), and zinc(II), several new metal complexes of cross-bridged tetraazamacrocyclic chelators namely, cyclen- and cyclam-analogs with benzyl groups, were synthesized and screened for in vitro antimalarial activity against chloroquine-resistant (W2) and chloroquine-sensitive (D6) strains of Plasmodium falciparum. The metal-free chelators tested showed little or no antimalarial activity. All the metal complexes of the dibenzyl cross-bridged cyclam ligand exhibited potent antimalarial activity. The Mn2+ complex of this ligand was the most potent with IC50s of 0.127 and 0.157 µM against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) P. falciparum strains, respectively. In general, the dibenzyl hydrophobic ligands showed better antimalarial activity compared to the activity of monobenzyl ligands, potentially because of their higher lipophilicity and thus better cell penetration ability. The higher antimalarial activity displayed by the manganese complex for the cyclam ligand in comparison to that of the cyclen, correlates with the larger pocket of cyclam compared to that of cyclen which produces a more stable complex with the Mn2+. Few of the Cu2+ and Fe2+ complexes also showed improvement in activity but Ni2+, Co2+ and Zn2+ complexes did not show any improvement in activity upon the metal-free ligands for anti-malarial development. PMID:24857776

  2. 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

  3. Molecular mechanisms underlying skeletal muscle weakness in human cancer: reduced myosin-actin cross-bridge formation and kinetics.

    PubMed

    Toth, Michael J; Miller, Mark S; Callahan, Damien M; Sweeny, Andrew P; Nunez, Ivette; Grunberg, Steven M; Der-Torossian, Hirak; Couch, Marion E; Dittus, Kim

    2013-04-01

    Many patients with cancer experience physical disability following diagnosis, although little is known about the mechanisms underlying these functional deficits. To characterize skeletal muscle adaptations to cancer in humans, we evaluated skeletal muscle structure and contractile function at the molecular, cellular, whole-muscle, and whole-body level in 11 patients with cancer (5 cachectic, 6 noncachectic) and 6 controls without disease. Patients with cancer showed a 25% reduction in knee extensor isometric torque after adjustment for muscle mass (P < 0.05), which was strongly related to diminished power output during a walking endurance test (r = 0.889; P < 0.01). At the cellular level, single fiber isometric tension was reduced in myosin heavy chain (MHC) IIA fibers (P = 0.05) in patients with cancer, which was explained by a reduction (P < 0.05) in the number of strongly bound cross-bridges. In MHC I fibers, myosin-actin cross-bridge kinetics were reduced in patients, as evidenced by an increase in myosin attachment time (P < 0.01); and reductions in another kinetic parameter, myosin rate of force production, predicted reduced knee extensor isometric torque (r = 0.689; P < 0.05). Patients with cancer also exhibited reduced mitochondrial density (-50%; P < 0.001), which was related to increased myosin attachment time in MHC I fibers (r = -0.754; P < 0.01). Finally, no group differences in myofilament protein content or ultrastructure were noted that explained the observed functional alterations. Collectively, our results suggest reductions in myofilament protein function as a potential molecular mechanism contributing to muscle weakness and physical disability in human cancer.

  4. 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.

  5. Level II scour analysis for Bridge 49 (BETHTH00790049) on Town Highway 79, crossing Locust Creek, Bethel, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Olson, Scott A.

    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 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 ranged from 0.0 ft to 1.0 ft. The worst-case contraction scour occurred at the 100-year discharge. Abutment scour ranged from 10.3 ft to 13.3 ft. with the worst-case abutment scour also occurring 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 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” (Richardson and others, 1993, p. 22). 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 experienced engineering judgement.

  6. Level II scour analysis for Bridge 4 (MNTGTH00020004) on Town Highway 2, crossing Wade Brook, Montgomery, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.

    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 was 0.1 ft. The worst-case contraction scour occurred at the 100-year and 500-year discharges. Abutment scour ranged from 3.9 to 5.2 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). 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.

  7. Level II scour analysis for Bridge 28 (BRNATH00660028) on Town Highway 66, crossing Locust Creek, Barnard, Vermont

    USGS Publications Warehouse

    Severence, Timothy

    1997-01-01

    The Town Highway 66 crossing of the Locust Creek is a 41-ft-long, one-lane bridge consisting of a 39 ft steel stringer type bridge with a concrete deck (Vermont Agency of Transportation, written communication, August 24, 1994). The clear span is 36.8 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The upstream right wingwall is protected by stone fill. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is 0 degrees. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.

  8. 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

  9. Level II scour analysis for Bridge 51 (RANDTH00SC0051) on School Street, crossing Thayer Brook, Randolph, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    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.

  10. 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

  11. 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.

  12. Electron Tomographic Analysis of Cytoskeletal Cross-Bridges in the Paranodal Region of the Node of Ranvier in Peripheral Nerves

    PubMed Central

    Perkins, Guy A.; Sosinsky, Gina E.; Ghassemzadeh, Sassan; Perez, Alex; Jones, Ying; Ellisman, Mark H.

    2008-01-01

    The node of Ranvier is a site for ionic conductances along myelinated nerves and governs the saltatory transmission of action potentials. Defects in the cross-bridging and spacing of the cytoskeleton is a prominent pathologic feature in diseases of the peripheral nerve. Electron tomography was used to examine cytoskeletal-cytoskeletal, membrane-cytoskeletal, and heterologous cell connections in the paranodal region of the node of Ranvier in peripheral nerves. Focal attachment of cytoskeletal filaments to each other and to the axolemma and paranodal membranes of the Schwann cell via narrow cross-bridges was visualized in both neuronal and glial cytoplasms. A subset of intermediate filaments associates with the cytoplasmic surfaces of supramolecular complexes of transmembrane structures that are presumed to include known and unknown junctional proteins. Mitochondria were linked to both microtubules and neurofilaments in the axoplasm and to neighboring smooth endoplasmic reticulum by narrow cross-bridges. Tubular cisternae in the glial cytoplasm were also linked to the paranodal glial cytoplasmic loop juxtanodal membrane by short cross-bridges. In the extracellular matrix between axon and Schwann cell, junctional bridges formed long cylinders inking the two membranes. Interactions between cytoskeleton, membranes, and extracellular matrix associations in the paranodal region is likely critical not only for scaffolding, but also for intracellular and extracellular communication. PMID:18096402

  13. 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

  14. Level II scour analysis for Bridge 54 (RANDTH00BR0054) on Brook Street, crossing Thayer Brook, Randolph, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure RANDTH00BR0054 on Brook Street crossing Thayer Brook, Randolph, 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 Randolph. The 5.39-mi2 drainage area is in a predominantly rural basin. In the vicinity of the study site, the immediate banks are forested. In the study area, Thayer Brook has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 60 ft and an average channel depth of 3 ft. The predominant channel bed materials are gravel and cobble (D50 is 42.4 mm or 0.139 ft). The geomorphic assessment at the time of the Level I and Level II site visits on August 3, 1994 and December 5, 1994, indicated that the reach was vertically and laterally unstable. This assessment was due to the extreme channel misalignment with the bridge opening and the presence of a drop structure downstream of the bridge protecting against channel degradation. The Brook Street crossing of Thayer Brook is a 34-ft-long, two-lane bridge consisting of one 31-foot concrete span (Vermont Agency of Transportation, written communication, August 2, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. Streamflow attacks the upstream right wingwall and has undermined the upstream end of the right abutment. Type-2 stone fill (less than 36 inches diameter) exists only on the upstream and downstream sides of the left

  15. 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.

  16. Simulation model for combined motion of myosin cross-bridges agrees with experimental data.

    PubMed

    Marandos, Peter; Midde, Krishna

    2014-06-01

    The motivation for this work was to derive a theoretical model for the combined motion of a sample of muscle tissue with a small number (approximately 12) of myosin molecules. This was then compared to data collected at the University of North Texas Health Science center. A theoretical model of the motion of the myosin cross-bridges has been derived. The solution is a combination of solutions from the classical harmonic oscillator, Brownian motion, and Maxwell-Boltzmann statistics. The model illustrates the myosin behavior as a function of the number of myosin molecules, the temperature of the sample, and the spring constant. The results show that there is good agreement between the theoretical model and experimental data.

  17. Level II scour analysis for Bridge 51 (BRIDTH00460051) on Town Highway 46, crossing Ottauquechee River, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Ivanoff, Michael A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BRIDTH00460051 on town highway 46 crossing the 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). 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 103-mi2 drainage area is a predominantly rural basin. In the vicinity of the study site, the immediate left and right banks are covered by trees and brush with residences beyond. In the study area, the Ottauquechee River has a straight channel with a slope of approximately 0.008 ft/ft, an average channel top width of 150 ft and an average channel depth of 6 ft. The predominant channel bed materials are gravel and cobble with a median grain size (D50) of 81.8 mm (0.268 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 24, 1994, indicated that the reach was stable. The town highway 46 crossing of the Ottauquechee Riveris a 135-ft-long, two-lane bridge consisting of two 66-ft steel-beam spans, supported by vertical, concrete abutments with upstream wingwalls and one concrete pier (Vermont Agency of Transportation, written commun., August 24, 1994). Type-2 stone fill (less than 36 inches diameter) has been placed along the left abutment and both upstream wingwalls. The upstream side of both road embankments are also protected by type-2 stone fill. Abutments of a previous bridge still exist at the downstream side of the present structure’s abutments. The channel is

  18. Comparison of Orientation and Rotational Motion of Skeletal Muscle Cross-bridges Containing Phosphorylated and Dephosphorylated Myosin Regulatory Light Chain*

    PubMed Central

    Midde, Krishna; Rich, Ryan; Marandos, Peter; Fudala, Rafal; Li, Amy; Gryczynski, Ignacy; Borejdo, Julian

    2013-01-01

    Calcium binding to thin filaments is a major element controlling active force generation in striated muscles. Recent evidence suggests that processes other than Ca2+ binding, such as phosphorylation of myosin regulatory light chain (RLC) also controls contraction of vertebrate striated muscle (Cooke, R. (2011) Biophys. Rev. 3, 33–45). Electron paramagnetic resonance (EPR) studies using nucleotide analog spin label probes showed that dephosphorylated myosin heads are highly ordered in the relaxed fibers and have very low ATPase activity. This ordered structure of myosin cross-bridges disappears with the phosphorylation of RLC (Stewart, M. (2010) Proc. Natl. Acad. Sci. U.S.A. 107, 430–435). The slower ATPase activity in the dephosporylated moiety has been defined as a new super-relaxed state (SRX). It can be observed in both skeletal and cardiac muscle fibers (Hooijman, P., Stewart, M. A., and Cooke, R. (2011) Biophys. J. 100, 1969–1976). Given the importance of the finding that suggests a novel pathway of regulation of skeletal muscle, we aim to examine the effects of phosphorylation on cross-bridge orientation and rotational motion. We find that: (i) relaxed cross-bridges, but not active ones, are statistically better ordered in muscle where the RLC is dephosporylated compared with phosphorylated RLC; (ii) relaxed phosphorylated and dephosphorylated cross-bridges rotate equally slowly; and (iii) active phosphorylated cross-bridges rotate considerably faster than dephosphorylated ones during isometric contraction but the duty cycle remained the same, suggesting that both phosphorylated and dephosphorylated muscles develop the same isometric tension at full Ca2+ saturation. A simple theory was developed to account for this fact. PMID:23319584

  19. The cross-bridge dynamics is determined by two length-independent kinetics: Implications on muscle economy and Frank-Starling Law.

    PubMed

    Amiad Pavlov, Daria; Landesberg, Amir

    2016-01-01

    The cellular mechanisms underlying the Frank-Starling Law of the heart and the skeletal muscle force-length relationship are not clear. This study tested the effects of sarcomere length (SL) on the average force per cross-bridge and on the rate of cross-bridge cycling in intact rat cardiac trabeculae (n=9). SL was measured by laser diffraction and controlled with a fast servomotor to produce varying initial SLs. Tetanic contractions were induced by addition of cyclopiazonic acid, to maintain a constant activation. Stress decline and redevelopment in response to identical ramp shortenings, starting at various initial SLs, was analyzed. Both stress decline and redevelopment responses revealed two distinct kinetics: a fast and a slower phase. The duration of the rapid phases (4.2 ± 0.1 msec) was SL-independent. The second slower phase depicted a linear dependence of the rate of stress change on the instantaneous stress level. Identical slopes (70.5 ± 1.6 [1/s], p=0.33) were obtained during ramp shortening at all initial SLs, indicating that the force per cross-bridge and cross-bridge cycling kinetics are length-independent. A decrease in the slope at longer SLs was obtained during stress redevelopment, due to internal shortening. The first phase is attributed to rapid changes in the average force per cross-bridge. The second phase is ascribed to both cross-bridge cycling between its strong and weak conformations and to changes in the number of strong cross-bridges. Cross-bridge cycling kinetics and muscle economy are length-independent and the Frank-Starling Law cannot be attributed to changes in the force per cross-bridge or in the single cross-bridge cycling rates.

  20. Level II scour analysis for Bridge 29 (BRIDTH00360029) on Town Highway 36, crossing North Branch Ottauquechee River, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Ivanoff, Michael A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BRIDTH00360029 on town highway 36 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). 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 27.1-mi2 drainage area is a predominantly rural basin. In the vicinity of the study site, the left and right banks are covered by pasture and (or) fields with the immediate stream banks covered by woody vegetation. The left bank of North Branch Ottauquechee River is adjacent to Bridgewater town highway 001. In the study area, the North Branch Ottauquechee River has a sinuous channel with a slope of approximately 0.008 ft/ft, an average channel top width of 73 ft and an average bank height of 6 ft. The predominant channel bed materials are gravel and cobble with a median grain size (D50) of 61.0 mm (0.200 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 26, 1994, indicated that the reach was stable. The town highway 36 crossing of the North Branch Ottauquechee Riveris a 46-ft-long, one-lane bridge consisting of one 43-foot steel-beam span (Vermont Agency of Transportation, written communication, August 25, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. Type-2 (less than 36 inches) stone fill protects the upstream and downstream wingwalls. Sparse type-2 stone fill was also observed along the right abutment. The channel

  1. Cardiomyopathy mutations reveal variable region of myosin converter as major element of cross-bridge compliance.

    PubMed

    Seebohm, B; Matinmehr, F; Köhler, J; Francino, A; Navarro-Lopéz, F; Perrot, A; Ozcelik, C; McKenna, W J; Brenner, B; Kraft, T

    2009-08-05

    The ability of myosin to generate motile forces is based on elastic distortion of a structural element of the actomyosin complex (cross-bridge) that allows strain to develop before filament sliding. Addressing the question, which part of the actomyosin complex experiences main elastic distortion, we suggested previously that the converter domain might be the most compliant region of the myosin head domain. Here we test this proposal by studying functional effects of naturally occurring missense mutations in the beta-myosin heavy chain, 723Arg --> Gly (R723G) and 736Ile --> Thr (I736T), in comparison to 719Arg --> Trp (R719W). All three mutations are associated with hypertrophic cardiomyopathy and are located in the converter region of the myosin head domain. We determined several mechanical parameters of single skinned slow fibers isolated from Musculus soleus biopsies of hypertrophic cardiomyopathy patients and healthy controls. Major findings of this study for mutation R723G were i), a >40% increase in fiber stiffness in rigor with a 2.9-fold increase in stiffness per myosin head (S( *)(rigor R723G) = 0.84 pN/nm S( *)(rigor WT) = 0.29 pN/nm); and ii), a significant increase in force per head (F( *)(10 degrees C), 1.99 pN vs. 1.49 pN = 1.3-fold increase; F( *)(20 degrees C), 2.56 pN vs. 1.92 pN = 1.3-fold increase) as well as stiffness per head during isometric steady-state contraction (S( *)(active10 degrees C), 0.52 pN/nm vs. 0.28 pN/nm = 1.9-fold increase). Similar changes were found for mutation R719W (2.6-fold increase in S( *)(rigor); 1.8-fold increase in F( *)(10 degrees C), 1.6-fold in F( *)(20 degrees C); twofold increase in S( *)(active10 degrees C)). Changes in active cross-bridge cycling kinetics could not account for the increase in force and active stiffness. For the above estimates the previously determined fraction of mutated myosin in the biopsies was taken into account. Data for wild-type myosin of slow soleus muscle fibers support previous

  2. 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.

  3. 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

  4. 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.

  5. Effect of temperature on elementary steps of the cross-bridge cycle in rabbit soleus slow-twitch muscle fibres

    PubMed Central

    Wang, Gang; Kawai, Masataka

    2001-01-01

    Isometric tension, stiffness and the cross-bridge kinetics in rabbit soleus slow-twitch fibres (STFs) were studied in the temperature range 5–37°C by sinusoidal analysis. The effects of MgATP and phosphate (Pi) on the cross-bridge kinetics were studied, and the temperature dependence of the kinetic constants of elementary steps of the cross-bridge cycle was deduced in the range 20–37°C. The MgATP association constant (K1a) decreased when temperature was increased. The rate constants of the ATP-isomerization step (k1b and k−1b) and the cross-bridge detachment step (k2, and k−2) had Q10 values of 3–4, and hence their equilibrium constants (K1b and K2) changed little with temperature. Q10 of the force generation step (k4) was the largest at 6.7; its reversal step (k−4) had a Q10 of 2.5, and hence its equilibrium constant (K4) increased significantly with temperature. The Pi association constant (K5) changed little with temperature. The elementary steps of the cross-bridge cycle are more temperature sensitive in soleus STFs than in psoas, which are fast-twitch fibres. This is in accord with a higher temperature sensitivity of the apparent rate constants in STFs. The temperature dependence of the equilibrium constant of the force generation step (K4) was fitted to the modified Van't Hoff equation to deduce standard enthalpy change (ΔH°; 70 ± 20 kJ mol−1), standard entropy change (ΔS°; 250 ± 70 J mol−1 K−1), and heat capacity change (ΔCp; −12 ± 5 kJ mol−1 K−1). These results indicate that the force generation step is an entropy driven, endothermic reaction that accompanies a burial of large surface area. These observations are consistent with the hypothesis that hydrophobic interaction between residues of actin and myosin and between residues of the myosin head underlies the mechanism of force generation. An increase of isometric tension with temperature is accounted for by the increased number of cross-bridges in tension generating

  6. Evaluating interactions between river otters and muskrats at bridge crossings in Kentucky

    USGS Publications Warehouse

    Clark, Joseph D.; Williamson, Ryan

    2011-01-01

    hreatened or endangered. Muskrat populations have been reduced in some streams where North American river otters (Lontra canadensis) were reintroduced, and it has been hypothesized that otter reintroduction could be used as a tool for conservation of mussels. We used occupancy estimation methods to evaluate the ecological relationship between muskrats and otters by collecting presence–absence data based on field sign found at bridge crossings in eastern and central Kentucky. Mean detection probabilities (ps) and occupancy probabilities (ψs) for muskrats were 0.692 (SE  =  0.045) and 0.723 (SE  =  0.071) and for otters were 0.623 (SE  =  0.036) and 0.662 (SE  =  0.069), respectively. Otter occupancy was related negatively to distance from release sites, which suggests that the otter population is still expanding its range. A 2-species interaction model indicated that the occupancy by muskrats and river otters was independent, and we conclude that river otter reintroduction would not be an effective strategy for conserving mussels.

  7. Earliest mechanical evidence of cross-bridge activity after stimulation of single skeletal muscle fibers.

    PubMed

    Claflin, D R; Morgan, D L; Julian, F J

    1990-03-01

    The stiffness of single fibers from frog skeletal muscle was measured by the application of small 2-kHz sinusoidal length oscillations during twitch and tetanic contractions at a range of initial sarcomere lengths. The earliest mechanical signs of activation were a fall in tension (latency relaxation) and a rise in stiffness. The earliest stiffness increase and the earliest tension fall occurred simultaneously at all sarcomere lengths. This suggests a cross-bridge origin for the latency relaxation. The lead of stiffness over tension seen during the rise of tension was substantially established during the latent period. Reducing the size of the twitch by reducing calcium release with D-600 (methoxyverapamil) reduced the latency relaxation and the stiffness development during latency much less than it reduced the twitch tension. For very small twitches the peak of the stiffness response occurred during the latent period and the times of onset of both latency relaxation and stiffness rise were delayed, but remained coincident. This suggests a strong connection between the latency relaxation and the rise of stiffness during the latent period, whereas the connection between these events and positive tension generation appears to be less strong.

  8. Quasiperiodic distribution of rigor cross-bridges along a reconstituted thin filament in a skeletal myofibril.

    PubMed

    Suzuki, Madoka; Ishiwata, Shin'ichi

    2011-12-07

    Electron microscopy has shown that cross-bridges (CBs) are formed at the target zone that is periodically distributed on the thin filament in striated muscle. Here, by manipulating a single bead-tailed actin filament with optical tweezers, we measured the unbinding events of rigor CBs one by one on the surface of the A-band in rabbit skeletal myofibrils. We found that the spacings between adjacent CBs were not always the same, and instead were 36, 72, or 108 nm. Tropomyosin and troponin did not affect the CB spacing except for a relative increase in the appearance of longer spacing in the presence of Ca(2+). In addition, in an in vitro assay where myosin molecules were randomly distributed, were obtained the same spacing, i.e., a multiple of 36 nm. These results indicate that the one-dimensional distribution of CBs matches with the 36-nm half pitch of a long helical structure of actin filaments. A stereospecific model composed of three actin protomers per target zone was shown to explain the experimental results. Additionally, the unbinding force (i.e., the binding affinity) of CBs for the reconstituted thin filaments was found to be larger and smaller relative to that for actin filaments with and without Ca(2+), respectively.

  9. 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.

  10. 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.

  11. Level II scour analysis for Bridge 37 (BRIDTH00050037) on Town Highway 5, crossing North Branch Ottauquechee River, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Ivanoff, Michael A.

    1996-01-01

    . Additional details describing conditions at the site are included in the Level II Summary 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 0.4 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 11.0 to 14.9 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 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, 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

  12. Crossing the Divide: An Emerging Typology of Postsecondary Bridging for Opportunity Youth

    ERIC Educational Resources Information Center

    Almeida, Cheryl; Allen, Lili

    2016-01-01

    Through Job For the Future's (JFF's) work with communities around the country on the Back on Track model, postsecondary bridging strategies have emerged as a particularly critical and especially replicable component of programming for vulnerable youth. This issue brief offers a typology of evidence-informed bridge programming, drawing on…

  13. A New Cross-Link for an Old Cross-Linking Drug: The Nitrogen Mustard Anticancer Agent Mechlorethamine Generates Cross-Links Derived from Abasic Sites in Addition to the Expected Drug-Bridged Cross-Links.

    PubMed

    Nejad, Maryam Imani; Johnson, Kevin M; Price, Nathan E; Gates, Kent S

    2016-12-20

    Nitrogen mustard anticancer drugs generate highly reactive aziridinium ions that alkylate DNA. Monoadducts arising from reaction with position N7 of guanine residues are the major DNA adducts generated by these agents. Interstrand cross-links in which the drug bridges position N7 of two guanine residues are formed in low yields relative to those of the monoadducts but are generally thought to be central to medicinal activity. The N7-alkylguanine residues generated by nitrogen mustards are depurinated to yield abasic (Ap) sites in duplex DNA. Here, we show that Ap sites generated by the nitrogen mustard mechlorethamine lead to interstrand cross-links of a type not previously associated with this drug. Gel electrophoretic data were consistent with early evolution of the expected drug-bridged cross-links, followed by the appearance of Ap-derived cross-links. The evidence is further consistent with a reaction pathway involving alkylation of a guanine residue in a 5'-GT sequence, followed by depurination to generate the Ap site, and cross-link formation via reaction of the Ap aldehyde residue with the opposing adenine residue at this site [Price, N. E., Johnson, K. M., Wang, J., Fekry, M. I., Wang, Y., and Gates, K. S. (2014) J. Am. Chem. Soc. 136, 3483-3490]. The monofunctional DNA-alkylating agents 2-chloro-N,N-diethylethanamine 5, (2-chloroethyl)ethylsulfide 6, and natural product leinamycin similarly were found to induce the formation of Ap-derived cross-links in duplex DNA. This work provides the first characterization of Ap-derived cross-links at sequences in which a cytosine residue is located directly opposing the Ap site. Cross-linking processes of this type could be relevant in medicine and biology because Ap sites with directly opposing cytosine residues occur frequently in genomic DNA via spontaneous or enzymatic depurination of guanine and N7-alkylguanine residues.

  14. Lifelong Learning: Crossing Bridges into New Territories. Proceedings of the Annual Meeting of the Association for Continuing Higher Education (66th, Newport, RI, October 30-November 3, 2004)

    ERIC Educational Resources Information Center

    Barrineau, Irene T.

    2004-01-01

    These proceedings record the 66th Annual Meeting of the Association for Continuing Higher Education held in Newport, Rhode Island. President Jerry Hickerson's theme for this annual meeting was, "Lifelong Learning: Crossing Bridges into New Territories." This theme asked us to examine the bridges that we build to diversity, articulation, research,…

  15. 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

  16. Superexchange contributions to distance dependence of electron transfer/transport: exchange and electronic coupling in oligo(para-phenylene)- and oligo(2,5-thiophene)-bridged donor-bridge-acceptor biradical complexes.

    PubMed

    Kirk, Martin L; Shultz, David A; Stasiw, Daniel E; Lewis, Geoffrey F; Wang, Guangbin; Brannen, Candice L; Sommer, Roger D; Boyle, Paul D

    2013-11-13

    The preparation and characterization of three new donor-bridge-acceptor biradical complexes are described. Using variable-temperature magnetic susceptibility, EPR hyperfine coupling constants, and the results of X-ray crystal structures, we evaluate both exchange and electronic couplings as a function of bridge length for two quintessential molecular bridges: oligo(para-phenylene), β = 0.39 Å(-1) and oligo(2,5-thiophene), β = 0.22 Å(-1). This report represents the first direct comparison of exchange/electronic couplings and distance attenuation parameters (β) for these bridges. The work provides a direct measurement of superexchange contributions to β, with no contribution from incoherent hopping. The different β values determined for oligo(para-phenylene) and oligo(2,5-thiophene) are due primarily to the D-B energy gap, Δ, rather than bridge-bridge electronic couplings, H(BB). This is supported by the fact that the H(BB) values extracted from the experimental data for oligo(para-phenylene) (H(BB) = 11,400 cm(-1)) and oligo(2,5-thiophene) (12,300 cm(-1)) differ by <10%. The results presented here offer unique insight into the intrinsic molecular factors that govern H(DA) and β, which are important for understanding the electronic origin of electron transfer and electron transport mediated by molecular bridges.

  17. What Force Structure Best Positions the Divisional Engineer Bridge Company to Support River Crossing Operations?

    DTIC Science & Technology

    1991-06-07

    security , movement, and communication tasks. KEY POINT *3: Retaining the engineer bridge company in the division will allow continued habitual training...1991 Approved for public release, distribution is unlimited. 91-15486 Oc :,+,I dm ’+’REPORT DOCUMENTATIOu>PAGE, 0MB No 0704-0188 PbVic f0portin brdnq... PUBLIC RELEASE: DISTRIBUTION IS UNLIITED. A 13. ABSTRACT (Maximum 200 woris) This study researches the positioning of the current Heavy Division Bridge

  18. Exploration of disulfide bridge and N-glycosylation contributing to high thermostability of a hybrid xylanase.

    PubMed

    Tan, Zhongbiao; Tang, Cunduo; Wu, Minchen; He, Yao; Hu, Die; Wang, Junqing

    2014-07-01

    A comparison between three-dimensional structures of a wild-type xylanase AoXyn11A and a hybrid xylanase AEx11A revealed that a disulfide bridge (Cys(5)-Cys(32)) and an N-glycosylation site (Asn(42)) were imported into AEx11A by N-terminal substitution of AoXyn11A with EvXyn11(TS). Two mutant genes AEx11A(C5T) and AEx11A(N42Q) were constructed by mutating Cys(5)- and Asn(42)-encoding codons of AEx11A into Thr(5)- and Gln(42)-encoding ones, and heterologously expressed in Pichia pastoris GS115, respectively. The temperature optimum of the recombinant AEx11A(C5T) (reAEx11A(C5T)) was decreased to 60°C from 80°C of reAEx11A, while its thermal inactivation half-lives at 70 and 80°C shortened to 3 and 1 min from 197 and 25 min of reAEx11A, respectively. However, there was no obvious alteration between reAEx11A and reAEx11A(C5T) in pH characteristics and kinetic parameters. Furthermore, both reAEx11A(N42Q) and reAEx11A displayed no significant difference in all enzymatic properties tested, except for the apparent molecular weight. We concluded based on this study that the disulfide bridge of AEx11A was vital to its high thermostability, but the N-glycosylation had no effect on.

  19. Avidin-biotin interactions at vesicle surfaces: adsorption and binding, cross-bridge formation, and lateral interactions.

    PubMed

    Noppl-Simson, D A; Needham, D

    1996-03-01

    Densely packed domains of membrane proteins are important structures in cellular processes that involve ligand-receptor binding, receptor-mediated adhesion, and macromolecule aggregation. We have used the biotin-avidin interaction at lipid vesicle surfaces to mimic these processes, including the influence of a surface grafted polymer, polyethyleneglycol (PEG). Single vesicles were manipulated by micropipette in solutions of fluorescently labeled avidin to measure the rate and give an estimate of the amount of avidin binding to a biotinylated vesicle as a function of surface biotin concentration and surface-grafted PEG as PEG-lipid. The rate of avidin adsorption was found to be four times less with 2 mol% PEG750 than for the unmodified surface, and 10 mol% PEG completely inhibited binding of avidin to biotin for a 2-min incubation. Using two micropipettes, an avidin-coated vesicle was presented to a biotinylated vesicle. In this vesicle-vesicle adhesion test, the accumulation of avidin in the contact zone was observed, again by using fluorescent avidin. More importantly, by controlling the vesicle membrane tension, this adhesion test provided a direct measure of the spreading pressure of the biotin-avidin-biotin cross-bridges confined in the contact zone. Assuming ideality, this spreading pressure gives the concentration of avidin cross-bridges in the contact zone. The rate of cross-bridge accumulation was consistent with the diffusion of the lipid-linked "receptors" into the contact zone. Once adherent, the membranes failed in tension before they could be peeled apart. PEG750 did not influence the mechanical equilibrium because it was not compressed in the contact zone, but it did perform an important function by eliminating all nonspecific adhesion. This vesicle-vesicle adhesion experiment, with a lower tension limit of 0.01 dyn/cm, now provides a new and useful method with which to measure the spreading pressures and therefore colligative properties of a range of

  20. Bacteriophage-derived CHAP domain protein, P128, kills Staphylococcus cells by cleaving interpeptide cross-bridge of peptidoglycan.

    PubMed

    Sundarrajan, Sudarson; Raghupatil, Junjappa; Vipra, Aradhana; Narasimhaswamy, Nagalakshmi; Saravanan, Sanjeev; Appaiah, Chemira; Poonacha, Nethravathi; Desai, Srividya; Nair, Sandhya; Bhatt, Rajagopala Narayana; Roy, Panchali; Chikkamadaiah, Ravisha; Durgaiah, Murali; Sriram, Bharathi; Padmanabhan, Sriram; Sharma, Umender

    2014-10-01

    P128 is an anti-staphylococcal protein consisting of the Staphylococcus aureus phage-K-derived tail-associated muralytic enzyme (TAME) catalytic domain (Lys16) fused with the cell-wall-binding SH3b domain of lysostaphin. In order to understand the mechanism of action and emergence of resistance to P128, we isolated mutants of Staphylococcus spp., including meticillin-resistant Staphylococcus aureus (MRSA), resistant to P128. In addition to P128, the mutants also showed resistance to Lys16, the catalytic domain of P128. The mutants showed loss of fitness as shown by reduced rate of growth in vitro. One of the mutants tested was found to show reduced virulence in animal models of S. aureus septicaemia suggesting loss of fitness in vivo as well. Analysis of the antibiotic sensitivity pattern showed that the mutants derived from MRSA strains had become sensitive to meticillin and other β-lactams. Interestingly, the mutant cells were resistant to the lytic action of phage K, although the phage was able to adsorb to these cells. Sequencing of the femA gene of three P128-resistant mutants showed either a truncation or deletion in femA, suggesting that improper cross-bridge formation in S. aureus could be causing resistance to P128. Using glutathione S-transferase (GST) fusion peptides as substrates it was found that both P128 and Lys16 were capable of cleaving a pentaglycine sequence, suggesting that P128 might be killing S. aureus by cleaving the pentaglycine cross-bridge of peptidoglycan. Moreover, peptides corresponding to the reported cross-bridge of Staphylococcus haemolyticus (GGSGG, AGSGG), which were not cleaved by lysostaphin, were cleaved efficiently by P128. This was also reflected in high sensitivity of S. haemolyticus to P128. This showed that in spite of sharing a common mechanism of action with lysostaphin, P128 has unique properties, which allow it to act on certain lysostaphin-resistant Staphylococcus strains.

  1. New cross-bridged cyclam derivative CB-TE1K1P, an improved bifunctional chelator for copper radionuclides.

    PubMed

    Zeng, Dexing; Ouyang, Qin; Cai, Zhengxin; Xie, Xiang-Qun; Anderson, Carolyn J

    2014-01-04

    A new cross-bridged cyclam chelator, CB-TE1K1P, was developed for copper-based radiopharmaceuticals, and this chelator can be labelled with (64)Cu under mild conditions in high specific activity. DBCO-PEG4-CB-TE1K1P was synthesized for conjugation to proteins, while Dde-CB-TE1K1P((t)Bu2)-OH was synthesized for solid-phase peptide synthesis. Examples of the conjugation chemistry, radiolabelling and serum stability of each are presented.

  2. 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…

  3. 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.

  4. 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.

  5. The role of MgADP in force maintenance by dephosphorylated cross-bridges in smooth muscle: a flash photolysis study.

    PubMed Central

    Khromov, A; Somlyo, A V; Trentham, D R; Zimmermann, B; Somlyo, A P

    1995-01-01

    The effect of [MgADP] on relaxation from isometric tension, initiated by reducing free [Ca2+] through photolysis of the caged photolabile Ca2+ chelator diazo-2, was determined at 20 degrees C in alpha-toxin permeabilized tonic (rabbit femoral artery, Rf) and phasic (rabbit bladder, Rb) smooth muscle. In Rf, the shape of the relaxation curve was clearly biphasic, consisting of a slow "plateau" phase followed by a monotonic exponential decline with rate constant k. The duration of the plateau (d = 44 +/- 4 s, mean +/- SEM, n = 28) was well correlated (R = 0.92) with the total t1/2 of relaxation that was 66 +/- 3 s (n = 28) in the presence of 20 mM creatine phosphate (CP), and was prolonged in the absence of CP (t1/2 = 83 +/- 3 s, n = 7); addition of 100 microM MgADP further slowed relaxation (t1/2 = 132 +/- 7 s, n = 14). In Rb, a plateau was not detectable and t1/2 (= 15 +/- 2 s, n = 6) was not affected by 100 microM MgADP. In Rf the Q10 between 20 degrees C and 30 degrees C was 4.3 +/- 0.4 for d-1 and 2.8 +/- 0.3 for k (n = 8; p = 0.006). The regulatory myosin light chain (MLC20) in Rf was dephosphorylated at 0.07 +/- 0.02 s-1, from 42 +/- 3% before to 20 +/- 2% after photolysis of diazo-2, reaching basal values at a time when force had fallen by only 40%. We conclude that, in the presence of ATP, as during rigor, the affinity of dephosphorylated cross-bridges for MgADP is significantly higher in tonic than in phasic smooth muscle and contributes to the maintenance of force at low levels of phosphorylation. The MgADP dependence of the post-dephosphorylation phase of relaxation is consistent with its being rate-limited by the slow off-rate of ADP from cross-bridges that were dephosphorylated while in force-generating ADP-bound (AM*D) cross-bridge states. The fourfold faster off-rate of ADP from AM*D in the phasic, Rb, compared to tonic, Rf, smooth muscle is a major determinant of the different kinetics of relaxation in the two types of smooth muscle. PMID:8599668

  6. Level II scour analysis for Bridge 48 (FFIETH00300048) on Town Highway 30, crossing Wanzer Brook, Fairfield, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Boehmler, Erick M.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure FFIETH00300048 on Town Highway 30 crossing Wanzer Brook, Fairfield, 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 northwestern Vermont. The 6.78-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover upstream of the bridge and on the downstream right bank is primarily pasture. The downstream left bank is forested. In the study area, Wanzer Brook has an incised, straight channel with a slope of approximately 0.03 ft/ft, an average channel top width of 65 ft and an average bank height of 5 ft. The channel bed material is cobble with a median grain size (D50) of 111 mm (0.364 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 11, 1995, indicated that the reach was stable. The Town Highway 30 crossing of Wanzer Brook is a 31-ft-long, two-lane bridge consisting of one 28-foot steel-beam span (Vermont Agency of Transportation, written communication, March 8, 1995). The opening length of the structure parallel to the bridge face is 26 ft.The bridge is supported by vertical stone wall abutments with concrete caps and “kneewall” footings. The channel is skewed approximately 25 degrees to the opening while the measured opening-skew-to-roadway is 20 degrees. A scour hole 1.5 ft deeper than

  7. Sarcomere-length dependence of lattice volume and radial mass transfer of myosin cross-bridges in rat papillary muscle.

    PubMed

    Yagi, Naoto; Okuyama, Hiroshi; Toyota, Hiroko; Araki, Junichi; Shimizu, Juichiro; Iribe, Gentaro; Nakamura, Kazufumi; Mohri, Satoshi; Tsujioka, Katsuhiko; Suga, Hiroyuki; Kajiya, Fumihiko

    2004-05-01

    We examined the sarcomere length-dependence of the spacing of the hexagonal lattice of the myofilaments and the mass transfer of myosin cross-bridges during contraction of right ventricular papillary muscle of the rat. The lattice spacing and mass transfer were measured by using X-ray diffraction, and the sarcomere length was monitored by laser diffraction at the same time. Although the lattice spacing and the sarcomere length were inversely related, their relationship was not exactly isovolumic. The cell volume decreased by about 15% when the sarcomere length was shortened from 2.3 micro m to 1.8 micro m. Twitch tension increased with sarcomere length (the Frank-Starling law). At the peak tension, the ratio of the intensity of the (1,0) equatorial reflection to that of the (1,1) reflection was smaller when the tension was greater, showing that the larger tension at a longer sarcomere length accompanies a larger amount of mass transfer of cross-bridges from the thick to the thin filament. The result suggests that the Frank-Starling law is due to an increase in the number of myosin heads attached to actin, not in the average force produced by each head.

  8. Master equation approach for a cross-bridge power-stroke model with a finite number of motors.

    PubMed

    Ma, Rui; Li, Ming; Ou-Yang, Zhong-Can; Shu, Yao-Gen

    2013-05-01

    The cross-bridge power-stroke model has been widely used to describe the motion of large motor assemblies connected to a common rigid filament. In this paper, we go beyond the original velocity-ensemble approach and propose a master equation approach to account for the cooperative motion of a finite number of motors based on the cross-bridge model. By studying the force-velocity relationship for motors with strain-independent detachment rate, we show the convergence of our approach to the velocity-ensemble approach in the limit of large motor numbers. In the case that the detachment rate of motors is strain dependent, based on two assumptions for the strain distribution among motors, we show the occurrence of the bimodal distribution of the number of motors bound to the filament. This provides a new perspective to look at the instability of a multimotor system, which is essential for all the experimentally observed complex motions displayed by a group of motors, such as hysteresis, bidirectional motion, and spontaneous oscillation. By comparing the velocities calculated using the two assumptions with the stochastic simulation, it suggests that the coupling between motors via the common connection to the filament might facilitate the fast movement of filaments at small loading forces.

  9. The Frank-Starling mechanism is not mediated by changes in rate of cross-bridge detachment.

    PubMed

    Wannenburg, T; Janssen, P M; Fan, D; de Tombe, P P

    1997-11-01

    We tested the hypothesis that the Frank-Starling relationship is mediated by changes in the rate of cross-bridge detachment in cardiac muscle. We simultaneously measured isometric force development and the rate of ATP consumption at various levels of Ca2+ activation in skinned rat cardiac trabecular muscles at three sarcomere lengths (2.0, 2.1, and 2.2 microns). The maximum rate of ATP consumption was 1.5 nmol.s-1.microliter fiber vol-1, which represents an estimated adenosinetriphosphatase (ATPase) rate of approximately 10 s-1 per myosin head at 24 degrees C. The rate of ATP consumption was tightly and linearly coupled to the level of isometric force development, and changes in sarcomere length had no effect on the slope of the force-ATPase relationships. The average slope of the force-ATPase relationships was 15.5 pmol.mN-1.mm-1. These results suggest that the mechanisms that underlie the Frank-Starling relationship in cardiac muscle do not involve changes in the kinetics of the apparent detachment step in the cross-bridge cycle.

  10. Bridging knowledge: reflections on crossing the boundaries between long-term care and support.

    PubMed

    McDaid, David; Cieza, Alarcos; Gomez, Ana Rico

    2009-06-22

    In March 2009 members of the research, policy and practice communities in the fields of ageing and disability came together in Barcelona for the first international conference on bridging knowledge in long-term care and support. This paper presents a brief snapshot of some of the key themes and ideas that emerged during three days of presentation and debate on methods, policy and practice.

  11. Bridging knowledge: reflections on crossing the boundaries between long-term care and support

    PubMed Central

    McDaid, David; Cieza, Alarcos; Gomez, Ana Rico

    2009-01-01

    In March 2009 members of the research, policy and practice communities in the fields of ageing and disability came together in Barcelona for the first international conference on bridging knowledge in long-term care and support. This paper presents a brief snapshot of some of the key themes and ideas that emerged during three days of presentation and debate on methods, policy and practice. PMID:19590760

  12. Breakage-fusion-bridge cycles and large insertions contribute to the rapid evolution of accessory chromosomes in a fungal pathogen.

    PubMed

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

    2013-06-01

    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

  13. Contribution of a putative salt bridge and backbone dynamics in the structural instability of human prion protein upon R208H mutation.

    PubMed

    Bamdad, Kourosh; Naderi-Manesh, Hossein

    2007-12-28

    Molecular dynamics simulation method is used to assess the contribution of a disease-associated salt bridge in the early stages of the conformational rearrangement of human prion protein upon Arg208-->His mutation, which causes Creutzfeldt-Jakob disease. Previous investigations have suggested that the breakage of this putative salt bridge (D144/E146<-->Arg208) between helix 1 and helix 3 is responsible for such a mutation-driven process. So far, no experimental data has been reported in order to distinguish the contribution of this single salt bridge in the initial steps of amyloid formation. Consequently, we decided to investigate the role of this salt bridge in early conformational rearrangements. To remove the salt bridge without perturbations in the backbone structure, the neutralized states of the involved residues were used. Three 10-ns molecular dynamics simulations on three initial structures have been performed. The results revealed that the early stages of the conformational rearrangements, against common belief, are mainly associated with the mutation-induced global changes in the backbone dynamics but not with the breaking of the salt bridge.

  14. Level II scour analysis for Bridge 17 (NEWHTH00200017) on Town Highway 20, crossing Little Otter Creek, New Haven, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Burns, Ronda L.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure NEWHTH00200017 on Town Highway 20 crossing Little Otter Creek, New Haven, 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 Champlain section of the St. Lawrence Valley physiographic province in west-central Vermont. The 10.8-mi2 drainage area is in a predominantly rural and wetland basin. In the vicinity of the study site, the surface cover is shrubland on the downstream right overbank. The surface cover of the downstream left overbank, the upstream right overbank and the upstream left overbank is wetland and pasture. In the study area, Little Otter Creek has a meandering channel with a slope of approximately 0.0007 ft/ft, an average channel top width of 97 ft and an average bank height of 5 ft. The channel bed material ranges from silt and clay to cobble. Medium sized silt and clay is the channel material upstream of the approach cross-section and downstream of the exit cross-section. The median grain size (D50) of the silt and clay channel bed material is 1.52 mm (0.005 ft), which was used for contraction and abutment scour computations. From the approach cross-section, under the bridge, and to the exit cross-section, stone fill is the channel bed material. The median grain size (D50) of the stone fill channel bed material is 95.7 mm (0.314 ft). The stone fill median grain size was used solely for armoring computations. The geomorphic assessment at the

  15. Level II scour analysis for Bridge 10 (HANCTH00010010) on Town Highway 1, crossing the White River, Hancock, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Ivanoff, Michael A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure HANCTH00010010 on town highway 1 crossing the White River, Hancock, 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. The 59.8-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is primarily grass with trees and brush on the immediate channel banks. In the study area, the White River has a sinuous channel with a slope of approximately 0.005 ft/ft, an average channel top width of 104 ft and an average channel depth of 6 ft. The predominant channel bed materials are gravel and cobble with a median grain size (D50) of 98.9 mm (0.325 ft). The geomorphic assessment at the time of the Level I and Level II site visit on November 15, 1994, indicated that the reach was stable. The town highway 1 crossing of the White River is a 91-ft-long, two-lane bridge consisting of one 89-foot steel-beam span (Vermont Agency of Transportation, written communication, August 26, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15 degrees to the opening while the opening-skew-to-roadway is 0 degrees. 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

  16. Level II scour analysis for Bridge 4 (ARLITH00010004) on Town Highway 1, crossing Warm Brook, Arlington, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Ivanoff, Michael A.

    1997-01-01

    channel in the upstream reach within 30 ft of the bridge. The only scour protection measure at the site was type-2 stone fill (less than 36 inches diameter) along the upstream left bank approach 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, 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 1.7 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 8.3 to 11.9 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

  17. Level II scour analysis for Bridge 49 (BENNCYHUNT0049) on Hunt Street, crossing the Walloomsac River, Bennington, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Medalie, Laura

    1997-01-01

    2 stone fill also protects the channel banks upstream and downstream of the bridge for a minimum distance of 17 feet from the respective bridge faces. 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 computed for all modelled flows ranged from 0.9 to 5.0 ft. The worst-case contraction scour occurred at the 500-year discharge. Computed left abutment scour ranged from 15.3 to 16.5 ft. with the worst-case scour occurring at the incipient roadway-overtopping discharge. Computed right abutment scour ranged from 6.0 to 8.7 ft. with the worst-case 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, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited

  18. 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

  19. 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

  20. 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

  1. Level II scour analysis for Bridge 40 (ROCKTH00140040) on Town Highway 14, crossing the Williams River, Rockingham, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ROCKTH00140040 on Town Highway 14 crossing the Williams River, Rockingham, 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. The site is in the New England Upland section of the New England physiographic province in southeastern Vermont. The 99.2-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture downstream of the bridge. Upstream of the bridge, the left bank is forested and the right bank is suburban. In the study area, the Williams River has an incised, sinuous channel with a slope of approximately 0.005 ft/ft, an average channel top width of 154 ft and an average bank height of 11 ft. The channel bed material ranges from silt and clay to cobble with a median grain size (D50) of 45.4 mm (0.149 ft). The geomorphic assessment at the time of the Level I and Level II site visit on September 4, 1996, indicated that the reach was stable. The Town Highway 14 crossing of the Williams River is a 106-ft-long, one-lane covered bridge consisting of two steel-beam spans with a maximum span length of 73 ft (Vermont Agency of Transportation, written communication, April 6, 1995). The opening length of the structure parallel to the bridge face is 94.5 ft. The bridge is supported by a vertical, concrete abutment with wingwalls on the left, a vertical, laid-up stone abutment on the right and a concrete pier. The channel is skewed

  2. No bridge too high: infants decide whether to cross based on the probability of falling not the severity of the potential fall.

    PubMed

    Kretch, Kari S; Adolph, Karen E

    2013-05-01

    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 height affects the severity of the potential fall. For both crawlers and walkers, decisions about crossing bridges depended only on the probability of falling: As bridge width decreased, attempts to cross decreased, and gait modifications and exploration increased, but behaviors did not differ between small and large drop-off conditions. Similarly, decisions about descent depended on the probability of falling: Infants backed or crawled into the small drop-off, but avoided the large drop-off. With no drop-off, infants ran straight across. Results indicate that experienced crawlers and walkers accurately perceive affordances for locomotion, but they do not yet consider the severity of a potential fall when making decisions for action.

  3. 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

  4. Contribution of Disulfide Bridging to Epitope Expression of the Dengue Type 2 Virus Envelope Glycoprotein

    PubMed Central

    Roehrig, John T.; Volpe, Katharine E.; Squires, Jennifer; Hunt, Ann R.; Davis, Brent S.; Chang, Gwong-Jen J.

    2004-01-01

    The individual contributions of each of the six conserved disulfide (SS) bonds in the dengue 2 virus envelope (E) glycoprotein (strain 16681) to epitope expression was determined by measuring the reactivities of a panel of well-defined monoclonal antibodies (MAbs) with LLC-MK2 cells that had been transiently transformed with plasmid vectors expressing E proteins that were mutant in their SS bonds. Three domain I (DI) epitopes (C1, C3, and C4) were affected by elimination of any SS bond and were essentially the only epitopes affected by elimination of the amino-proximal SS1 formed between Cys 3 and Cys 30. The remaining DI epitope (C2) was sensitive to only SS3-bond (Cys 74-Cys 105) and SS6-bond (Cys 302-Cys 333) elimination. Of the four DII epitopes examined, reactivities of three anti-epitope MAbs (A1, A2, and A5) were reduced by elimination of SS2 (Cys 61-Cys 121), SS3, SS4 (Cys 94-Cys 116), SS5 (Cys 185-Cys 285), or SS6. The other DII epitope examined (A3) was sensitive only to SS2- and SS3-bond elimination. The three DIII epitopes tested (B2, B3, and B4) were most sensitive to elimination of SS6. The flavivirus group epitope (A1) was less sensitive to elimination of SS3 and SS6. This result may indicate that the region proximal to the E-protein fusion motif (amino acids 98 to 110) may have important linear components. If this observation can be confirmed, peptide mimics from this region of E protein might be able to interfere with flavivirus replication. PMID:14963174

  5. Level II scour analysis for Bridge 46 (FFIETH00470046) on Town Highway 47, crossing Black Creek, Fairfield, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Flynn, Robert H.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure FFIETH00470046 on Town Highway 47 crossing Black Creek, Fairfield, 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, gathered 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 northwestern Vermont. The 37.8 mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream and downstream of the bridge while the immediate banks have dense woody vegetation. In the study area, Black Creek has a meandering channel with a slope of approximately 0.0005 ft/ft, an average channel top width of 51 ft and an average bank height of 6 ft. The channel bed material ranges from sand to bedrock with a median grain size (D50) of 0.189 mm (0.00062 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 12, 1995, indicated that the reach was stable. The Town Highway 47 crossing of Black Creek is a 35-ft-long, one-lane bridge consisting of one 31-ft steel-stringer span (Vermont Agency of Transportation, written communication, March 8, 1995). The opening length of the structure parallel to the bridge face is 28.0 ft. The bridge is supported by vertical, laid-up stone abutments with wingwalls. The channel is skewed approximately zero degrees to the opening and the opening-skew-toroadway is zero degrees. A scour hole 6.0 ft deeper than the mean thalweg depth was observed just downstream of the

  6. 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.

  7. Level II scour analysis for Bridge 28 (BRIDTH00440028) on Town Highway 044 crossing Plymouth Brook, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Ayotte, Joseph D.

    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.

  8. Level II scour analysis for Bridge 7 (ANDOTH00010007) on Town Highway 1, crossing Andover Brook, Andover, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ANDOTH00010007 on Town Highway 1 crossing Andover Branch, 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 southern Vermont. The 7.21-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream of the bridge while the immediate banks have dense woody vegetation. Downstream of the bridge, the banks and overbanks are forested. In the study area, Andover Branch has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 45 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 58.0 mm (0.19 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 28, 1996, indicated that the reach was laterally unstable due to evidence of lateral movement of the channel 200 feet upstream along the left bank and near the bridge along the right bank. The Town Highway 1 crossing of Andover Branch is a 32-ft-long, two-lane bridge consisting of one 29-foot concrete slab span (Vermont Agency of Transportation, written communication, March 28, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the

  9. Level II scour analysis for Bridge 34 (BRIDTH00050034) on Town Highway 005, crossing North Branch Ottauquechee River, Bridgewater, Vermont

    USGS Publications Warehouse

    Ayotte, Joseph D.

    1996-01-01

    The town highway 31 crossing of Lilliesville Brook is a 41-ft-long, one-lane bridge consisting of one 39-foot steel-beam span with a timber deck (Vermont Agency of Transportation, written commun., August 24, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 35 degrees to the opening while the opening-skew-to-roadway is 0 degrees. Scour protection measures in place at the site were type-1 stone fill (less than 12 inches diameter) at the downstream left wingwall, left abutment, and upstream and downstream sides of the left road embankment. 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.

  10. Level II scour analysis for Bridge 44 (CHESVT00110044) on State Route 11, crossing Andover Brook, Chester, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Hammond, Robert E.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure CHESVT00110044 on State Route 11 crossing Andover Brook, 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 12.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture with dense woody vegetation on the immediate banks except the downstream left bank of the bridge which is forested. In the study area, Andover Brook has an incised, meandering channel with a slope of approximately 0.02 ft/ft, an average channel top width of 74 ft and an average bank height of 8 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 83.6 mm (0.274 ft). The geomorphic assessment at the time of the Level I and Level II site visit on September 11, 1996, indicated that the reach was stable. The State Route 11 crossing of Andover Brook is a 58-ft-long, two-lane bridge consisting of one 56-foot concrete T-beam span (Vermont Agency of Transportation, written communication, March 29, 1995). The opening length of the structure parallel to the bridge face is 52.9 ft.The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 35 degrees to the opening while the opening-skew-to-roadway is 45 degrees. A scour hole 1.8 ft

  11. Level II scour analysis for Bridge 33 (WWINTH00300033) on Town Highway 30, crossing Mill Brook, West Windsor, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Flynn, Robert H.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure WWINTH00300033 on Town Highway 30 crossing Mill Brook, West Windsor, 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. The site is in the New England Upland section of the New England physiographic province in east-central Vermont. The 24.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream of the bridge while the immediate banks have dense woody vegetation. Downstream of the bridge is forested. In the study area, Mill Brook has an incised, sinuous channel with a slope of approximately 0.004 ft/ft, an average channel top width of 58 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 65.7 mm (0.215 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 5, 1996, indicated that the reach was stable. The Town Highway 30 crossing of the Mill Brook is a 46-ft-long, one-lane covered bridge consisting of a 40-foot wood-beam span (Vermont Agency of Transportation, written communication, March 23, 1995). The opening length of the structure parallel to the bridge face is 36.3 ft. The bridge is supported by vertical, concrete capped laid-up stone abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is zero degrees. The only scour protection measure at

  12. 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.

  13. Level II scour analysis for Bridge 8 (ANDOTH00010008) on Town Highway 1, crossing Andover Branch, Andover, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Wild, Emily C.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ANDOTH00010008 on Town Highway 1 crossing the Andover Branch, 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 5.30-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover along the immediate banks, both upstream and downstream of the bridge, is grass while farther upstream and downstream, the surface cover is primarily forest.In the study area, the Andover Branch has an incised, straight channel with a slope of approximately 0.01 ft/ft, an average channel top width of 35 ft and an average bank height of 3 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 63.6 mm (0.209 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 27, 1996, indicated that the reach was stable.The Town Highway 1 crossing of the Andover Branch is a 54-ft-long, two-lane bridge consisting of one 51-foot steel-beam span (Vermont Agency of Transportation, written communication, March 28, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 45 degrees to the opening while the opening-skew-to-roadway is 30 degrees.A scour hole 0.7 ft deeper than the mean thalweg depth was observed

  14. Level II scour analysis for Bridge 29 (HUNTTH00290029) on Town Highway 29, crossing Cobb Brook, Huntington, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure HUNTTH00290029 on Town Highway 29 crossing Cobb Brook, Huntington, 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 northwestern Vermont. The 4.16-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream and downstream of the bridge. In the study area, Cobb Brook has an incised, straight channel with a slope of approximately 0.024 ft/ft, an average channel top width of 53 ft and an average bank height of 4 ft. The channel bed material ranges from gravel to bedrock with a median grain size (D50) of 112.0 mm (0.367 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 25, 1996, indicated that the reach was stable. The Town Highway 29 crossing of Cobb Brook is a 36-ft-long, one-lane bridge consisting of one 30-foot steel-beam span (Vermont Agency of Transportation, written communication, December 11, 1995) and a wooden deck. The opening length of the structure parallel to the bridge face is 27 ft.The bridge is supported by vertical, concrete abutments. The channel is skewed approximately 25 degrees to the opening while the opening-skew-to-roadway was measured to be 20 degrees. VTAOT records indicate an opening-skew-to-roadway of zero degrees. A scour hole 1.5 ft deeper than

  15. Level II scour analysis for Bridge 71 (WODSTH00050071) on Town Highway 5, crossing Kedron Brook, Woodstock, Vermont

    USGS Publications Warehouse

    Olson, S.A.; Ayotte, J.D.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 2.5 ft. The worst-case contraction scour occurred at the incipient roadway-overtopping discharge, which was less than the 100-year discharge. The contraction scour depths do not take the concrete channel bed under the bridge into account. Abutment scour ranged from 8.7 to 18.2 ft. The worstcase 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.

  16. Level II scour analysis for Bridge 46 (LINCTH00060046) on Town Highway 6, crossing the New Haven River, Lincoln, Vermont

    USGS Publications Warehouse

    Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure LINCTH00060046 on Town Highway 6 crossing the New Haven River, Lincoln, 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. The site is in the Green Mountain section of the New England physiographic province in west-central Vermont. The 45.9-mi2 drainage area is in a predominantly suburban and forested basin. In the vicinity of the study site, the surface cover is forest upstream of the bridge. The downstream right overbank near the bridge is suburban with buildings, homes, lawns, and pavement (less than fifty percent). The downstream left overbank is brushland while the immediate banks have dense woody vegetation. In the study area, the New Haven River has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 95 ft and an average bank height of 7 ft. The channel bed material ranges from sand to bedrock with a median grain size (D50) of 120.7 mm (0.396 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 13, 1996, indicated that the reach was stable. The Town Highway 34 crossing of the New Haven River is a 85-ft-long, two-lane bridge consisting of an 80-foot steel arch truss (Vermont Agency of Transportation, written communication, December 14, 1995). The opening length of the structure parallel to the bridge face is 69 feet. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed

  17. Level II scour analysis for Bridge 13 (LINCTH00010013) on Town Highway 1, crossing Cota Brook, Lincoln, Vermont

    USGS Publications Warehouse

    Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure LINCTH00010013 on Town Highway 1 crossing Cota Brook, Lincoln, 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. The site is in the Green Mountain section of the New England physiographic province in west-central Vermont. The 3.0-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest along the upstream right bank and brushland along the upstream left bank. Downstream of the bridge, the surface cover is pasture along the left and right banks. In the study area, Cota Brook has an sinuous channel with a slope of approximately 0.01 ft/ ft, an average channel top width of 30 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 34.7 mm (0.114 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 10, 1996, indicated that the reach was laterally unstable due to cut-banks and wide, vegetated point bars upstream and downstream of the bridge. The Town Highway 1 crossing of Cota Brook is a 38-ft-long, two-lane bridge consisting of a 36-foot steel-stringer span (Vermont Agency of Transportation, written communication, December 14, 1995). The opening length of the structure parallel to the bridge face is 34.4 ft. The bridge is supported by vertical, concrete abutments. The channel is skewed approximately 15 degrees to the opening while

  18. Level II scour analysis for Bridge 27 (WSTOTH00070027) on Town Highway 7, crossing Jenny Coolidge Brook, Weston, Vermont

    USGS Publications Warehouse

    Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure WSTOTH00070027 on Town Highway 7 crossing Jenny Coolidge 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 (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. The site is in the Green Mountain section of the New England physiographic province in southwestern Vermont. The 2.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture downstream of the bridge while upstream of the bridge is forested. In the study area, the Jenny Coolidge Brook has an incised, sinuous channel with a slope of approximately 0.04 ft/ft, an average channel top width of 51 ft and an average bank height of 6 ft. The channel bed material ranges from sand to boulders with a median grain size (D50) of 122 mm (0.339 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 20, 1996, indicated that the reach was stable. The Town Highway 7 crossing of the Jenny Coolidge Brook is a 52-ft-long, two-lane bridge consisting of a 50-foot steel-beam span (Vermont Agency of Transportation, written communication, April 7, 1995). The opening length of the structure parallel to the bridge face is 49.2 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 5 degrees to the opening while the computed opening-skew-to-roadway is 15 degrees. The legs of the skeleton-type right abutment were exposed approximately 2 feet

  19. Level II scour analysis for Bridge 7H (HUNTTH0001007H) on Town Highway 1, crossing Cobb Brook, Huntington, Vermont

    USGS Publications Warehouse

    Wild, Emily C.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure HUNTTH001007H on Town Highway 1 crossing the Cobb Brook, Huntington, Vermont (figures 1–10). 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.In August 1976, Hurricane Belle caused flooding at this site which resulted in road and bridge damage (figures 7-8). This was approximately a 25-year flood event (U.S. Department of Housing and Urban Development, 1978). The site is in the Green Mountain section of the New England physiographic province in central Vermont. The 4.20-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream of the bridge. Downstream of the bridge is brushland and pasture.In the study area, the Cobb Brook has an incised, straight channel with a slope of approximately 0.03 ft/ft, an average channel top width of 43 ft and an average bank height of 6 ft. The channel bed material ranges from sand to boulders with a median grain size (D50) of 65.5 mm (0.215 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 24, 1996, indicated that the reach was stable. The Town Highway 1 crossing of the Cobb Brook is a 23-ft-long, two-lane bridge consisting of one 20-foot concrete slab span (Vermont Agency of Transportation, written communication, June 21, 1996). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15 degrees

  20. Level II scour analysis for Bridge 33 (CONCTH00580033) on Town Highway 58, crossing Miles Stream, Concord, 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 CONCTH00580033 on Town Highway 58 crossing Miles Stream, Concord, 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 northeastern Vermont. The 17.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream of the bridge while the immediate banks have dense woody vegetation. Downstream of the bridge, the right bank is forested and the left bank has shrubs and brush. In the study area, Miles Stream has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 91 ft and an average bank height of 7 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 61.6 mm (0.188 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 15, 1995, indicated that the reach was stable. The Town Highway 58 crossing of Miles Stream is a 44-ft-long, two-lane bridge consisting of one 39-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 37.4 ft. The bridge is supported by vertical, concrete abutments with stone fill in front creating spillthrough embankments. The channel is skewed approximately 20 degrees

  1. Development of stiffness precedes cross-bridge attachment during the early tension rise in single frog muscle fibres.

    PubMed

    Bagni, M A; Cecchi, G; Colomo, F; Garzella, P

    1994-12-01

    1. Force responses to ramp stretches were recorded in single muscle fibres isolated from the lumbricalis muscle of the frog. Stretches were applied at rest and at progressively increasing times after a single stimulus. 2. The increase of fibre stiffness that precedes tension development has a 'static' component that accounts for the whole fibre stiffness increase during the latent period and at very low tension at the beginning of the twitch. 3. Static stiffness increase was not affected by 2,3-butanedione-2-monoxime, a drug that almost completely inhibited twitch tension. 4. Static stiffness increased approximately 5-fold as the sarcomere length was increased from 2.1 to 2.84 microns. 5. These results suggest that static fibre stiffness increase is not attributable to the formation of non-force-generating cross-bridges.

  2. Level II scour analysis for Bridge 63 (CHESTH00090063) on Town Highway 9, crossing the Williams River, Chester, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.

    1997-01-01

    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 1 (BLOOTH00020001) on Town Highway 2, crossing Mill Brook, Bloomfield, Vermont

    USGS Publications Warehouse

    Ayotte, Joseph D.; Medalie, Laura

    1996-01-01

    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 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 to 1.0 feet and the worst-case contraction scour occurred at the incipient overtopping discharge. Abutment scour ranged from 7.3 to 10.1 feet and 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.

  4. 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

  5. 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.

  6. Level II scour analysis for Bridge 32 (BRNATH00470032) on Town Highway 47, crossing Locust Creek, Barnard, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.

    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 these computed results follow. Contraction scour for all modelled flows ranged from 1.4 to 2.2 feet. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 10.3 to 15.0 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 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. 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 96 (BLOOVT01050096) on Vermont Route 105, crossing Nulhegan River, Bloomfield, Vermont

    USGS Publications Warehouse

    Ayotte, Joseph D.; Ivanoff, Michael A.

    1996-01-01

    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 0.5 to 1.1 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 10.5 to 16.2 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.

  8. Level II scour analysis for Bridge 21 (MIDBTH00230021) on Town Highway 23, crossing the Middlebury River, Middlebury, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Degnan, James R.

    1997-01-01

    year discharges. In addition, the incipient roadway-overtopping discharge is determined and analyzed as another potential worst-case scour scenario. 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 1.2 to 1.8 feet. The worst-case contraction scour occurred at the incipient overtopping discharge, which is less than the 500-year discharge. Abutment scour ranged from 17.7 to 23.7 feet. 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.

  9. 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.

  10. Level II scour analysis for Bridge 12 (FFIETH00030012) on Town Highway 3, crossing the Fairfield River, Fairfield, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Degnan, James R.

    1997-01-01

    downstream left bank. The type-2 stone fill on the left bank downstream changes to type-1 about 55 feet downstream 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 1.6 to 3.0 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 3.2 to 4.0 ft. at the left abutment and 9.7 to 11.7 feet at the right abutment. The worst-case left abutment scour occurred at the incipient over-topping discharge, which was less than the 100-year discharge. 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

  11. Level II scour analysis for Bridge 20 (IRASTH00080020) on Town Highway 8, crossing the Black River, Irasburg, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure IRASTH00080020 on town highway 8 crossing the Black River, Irasburg, 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 New England Upland physiographic province of north-central Vermont in the town of Irasburg. The 110-mi2 drainage area is in a predominantly rural basin. In the vicinity of the study site, the left bank surface cover is pasture and row crops and the right bank is covered by shrub and brush and is adjacent to woods. In the study area, the Black River has a sinuous channel with a slope of approximately 0.002 ft/ft, an average channel top width of 90 ft and an average channel depth of 5 ft. The predominant channel bed material is gravel and cobbles (D50 is 49.7 mm or 0.163 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 4, 1994, indicated that the reach was laterally unstable. The town highway 8 crossing of the Black River is a 88-ft-long, one-lane covered bridge consisting of one 80-foot span (Vermont Agency of Transportation, written commun., August 2, 1994). The bridge is supported by vertical, concrete abutments with wingwalls on the upstream and downstream sides of the right abutment. The right abutment has stone fill protection. The channel is skewed approximately 25 degrees to the opening while the opening-skew-to-roadway is zero degrees. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. Level II scour analysis for Bridge 33 (HUNTTH00220033) on Town Highway 22, crossing Brush Brook, Huntington, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Degnan, James R.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure HUNTTH00220033 on Town Highway 22 crossing Brush Brook, Huntington, 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 8.65-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 overbank which is pasture. In the study area, Brush Brook has an incised, straight channel with a slope of approximately 0.04 ft/ft, an average channel top width of 42 ft and an average bank height of 3 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 76.7 mm (0.252 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 26, 1996, indicated that the reach was stable. The Town Highway 22 crossing of Brush Brook is a 40-ft-long, two-lane bridge consisting of one 23.5-foot concrete slab span (Vermont Agency of Transportation, written communication, November 30, 1995). The opening length of the structure parallel to the bridge face is 36.9 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 35 degrees to the opening while the opening-skew-to-roadway is 30 degrees. The scour protection measure at the site was type-2 stone fill (less than 36 inches diameter

  1. 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 while

  2. Level II scour analysis for Bridge 47 (PLYMTH00540047) on Town Highway 54, crossing Pinney Hollow Brook, Plymouth, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Weber, Matthew A.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure PLYMTH00540047 on Town Highway 54 crossing Pinney Hollow Brook, Plymouth, 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, gathered 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 7.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream and downstream of the bridge while the immediate banks have dense woody vegetation. In the study area, Pinney Hollow Brook has an incised, straight channel with a slope of approximately 0.01 ft/ft, an average channel top width of 57 ft and an average bank height of 7 ft. The channel bed material ranges from sand to cobbles with a median grain size (D50) of 45.7 mm (0.150 ft). The geomorphic assessment at the time of the Level I and Level II site visit on March 30, 1995 and Level II site visit on October 2, 1995, indicated that the reach was stable. The Town Highway 54 crossing of Pinney Hollow Brook is a 30-ft-long, two-lane bridge consisting of a 27-foot steel-stringer span (Vermont Agency of Transportation, written communication, March 22, 1995). The opening length of the structure parallel to the bridge face is 25.7 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is not skewed to the opening and the opening-skew-to-roadway is zero degrees. Scour protection measures at the site included

  3. Level II scour analysis for Bridge 34 (HUNTTH00210034) on Town Highway 21, crossing Brush Brook, Huntington, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Ivanoff, Michael A.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure HUNTTH00210034 on Town Highway 21 crossing Brush Brook, Huntington, 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 6.23-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, Brush Brook has an incised, straight channel with a slope of approximately 0.03 ft/ft, an average channel top width of 43 ft and an average bank height of 4 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 June 26, 1996, indicated that the reach was stable. The Town Highway 21 crossing of Brush Brook is a 28-ft-long, one-lane bridge consisting of one 26-foot steel-beam span with a timber deck (Vermont Agency of Transportation, written communication November 30, 1995). The opening length of the structure parallel to the bridge face is 25.4 ft. The bridge is supported by vertical, concrete abutments with a wingwall on the upstream right. The channel is skewed approximately 5 degrees to the opening and the computed opening-skew-to-roadway is 5 degrees. A tributary enters Brush Brook on the right bank immediately downstream of the bridge. At the confluence, the

  4. Level II scour analysis for Bridge 4 (DANVTH00010004) on Town Highway 1, crossing Joes Brook, Danville, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Boehmler, Erick M.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure DANVTH00010004 on Town Highway 1 crossing Joes Brook, Danville, 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 northeastern Vermont. The 42.5-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture along the upstream and downstream left banks with trees and brush along the immediate banks. The upstream and downstream right banks are forested. In the study area, Joes Brook has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 68 ft and an average bank height of 5 ft. The channel bed material ranges from gravel to bedrock with a median grain size (D50) of 80.1 mm (0.263 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 22, 1995, indicated that the reach was stable. The Town Highway 1 crossing of Joes Brook is a 49-ft-long, two-lane bridge consisting of one 45-foot steel-beam span (Vermont Agency of Transportation, written communication, March 17, 1995). The opening length of the structure parallel to the bridge face is 45 ft.The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15 degrees to the opening and the computed opening-skew-to-roadway is 15 degrees. A scour

  5. Level II scour analysis for Bridge 37 (DUXBTH00120037) on Town Highway 12, crossing Ridley Brook, Duxbury, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Ivanhoff, Michael A.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure DUXBTH00120037 on Town Highway 12 crossing Ridley Brook, Duxbury, 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 10.1-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream and downstream of the bridge. In the study area, Ridley Brook has an incised, straight channel with a slope of approximately 0.04 ft/ft, an average channel top width of 67 ft and an average bank height of 9 ft. The channel bed material ranges from gravel to boulders with a median grain size (D50) of 123 mm (0.404 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 1, 1996, indicated that the reach was stable. The Town Highway 12 crossing of Ridley Brook is a 33-ft-long, two-lane bridge consisting of five 30-ft steel rolled beams (Vermont Agency of Transportation, written communication, October 13, 1995). The opening length of the structure parallel to the bridge face is 30 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 50 degrees to the opening while the measured opening-skew-to-roadway is 20 degrees. A scour hole 2 ft deeper than the mean thalweg depth was observed along the right abutment and downstream

  6. Level II scour analysis for Bridge 21 (MONKTH00340021) on Town Highway 34, crossing Little Otter Creek, Monkton, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Medalie, Laura

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure MONKTH00340021 on Town Highway 34 crossing Little Otter Creek, Monkton, 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 D 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 C. The site is in the Champlain section of the Saint Lawrence Valley physiographic province in northwestern Vermont. The 34.1-mi2 drainage area is in a predominantly rural and forested basin with pasture in the valleys. In the vicinity of the study site, the surface cover consists of pasture. The most significant tree cover is immediately adjacent to the channel on the right bank downstream. In the study area, Little Otter Creek has a sinuous channel with a slope of approximately 0.008 ft/ft, an average channel top width of 92 feet and an average bank height of 6 feet. The predominant channel bed materials are silt and clay. Sieve analysis indicates that greater than 50% of the sample is silt and clay and thus a median grain size by use of sieve analysis was indeterminate. Therefore, the median grain size was assumed to be medium silt with a size (D50) of 0.0310 mm (0.000102 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 19 and June 20, 1996, indicated that the reach was stable. The Town Highway 34 crossing of Little Otter Creek is a 50-ft-long, one-lane bridge consisting of one 26-foot concrete span and three “boiler tube” smooth metal pipe culverts through the left road approach (Vermont Agency of

  7. Level II scour analysis for Bridge 32 (TUNBTH00600032) on Town Highway 60, crossing First Branch White River, Tunbridge, Vermont

    USGS Publications Warehouse

    Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure TUNBTH00600032 on Town Highway 60 crossing the First Branch White River, Tunbridge, 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 92.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream and downstream of the bridge, while woody vegetation sparsely covers the immediate banks. In the study area, the First Branch White River has a sinuous channel with a slope of approximately 0.001 ft/ft, an average channel top width of 82 ft and an average bank height of 7 ft. The channel bed material ranges from sand to gravel with a median grain size (D50) of 24.4 mm (0.08 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 18, 1995, indicated that the reach was laterally unstable, as a result of block failure of moderately eroded banks. The Town Highway 60 crossing of the First Branch White River is a 74-ft-long, one-lane bridge consisting of a 71-foot timber thru-truss span (Vermont Agency of Transportation, written communication, August 24, 1994). The opening length of the structure parallel to the bridge face is 64 ft.The bridge is supported by vertical, laid-up stone abutments with upstream wingwalls. The channel is not skewed to the opening

  8. Level II scour analysis for Bridge 37 (PLYMTH00080037) on Town Highway 8, crossing Broad Brook, Plymouth, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Medalie, Laura

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure PLYMTH00080037 on Town Highway 8 crossing Broad Brook, Plymouth, 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, gathered 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 5.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream and downstream of the bridge. 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 46 ft and an average bank height of 5 ft. The channel bed material ranges from gravel to boulders with a median grain size (D50) of 87.5 mm (0.287 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 3, 1995, indicated that the reach was laterally unstable due to cut-banks present on the upstream left bank and the downstream left and right banks. The Town Highway 8 crossing of Broad Brook is a 31-ft-long, one-lane bridge consisting of a 28-foot steel-stringer span (Vermont Agency of Transportation, written communication, March 22, 1995). The opening length of the structure parallel to the bridge face is 27.0 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15 degrees to the opening while the opening-skew-to-roadway is 15 degrees. During the Level I assessment, it was

  9. Level II scour analysis for Bridge 25 (ROCHTH00400025) on Town Highway 40, crossing Corporation Brook, Rochester, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Weber, Matthew A.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ROCHTH00400025 on Town Highway 40 crossing Corporation Brook, Rochester, 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, from Vermont Agency of Transportation 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 4.97-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest on the upstream left and right overbanks, and the downstream left overbank. On the downstream right overbank, the surface cover is predominately brushland. In the study area, Corporation Brook has an incised, sinuous channel with a slope of approximately 0.04 ft/ft, an average channel top width of 37 ft and an average bank height of 6 ft. The channel bed material ranges from gravel to boulders with a median grain size (D50) of 101 mm (0.332 ft). The geomorphic assessment at the time of the Level I site visit on April 12, 1995 and Level I and II site visit on July 8, 1996, indicated that the reach was stable. The Town Highway 40 crossing of Corporation Brook is a 31-ft-long, one-lane bridge consisting of a 26-foot steel stringer span (Vermont Agency of Transportation, written communication, March 22, 1995). The opening length of the structure parallel to the bridge face is 24 ft. The bridge is supported by vertical, concrete abutments. The channel is skewed approximately 15 degrees to the opening while the opening-skew-to-roadway is 15 degrees. A scour hole 1

  10. Level II scour analysis for Bridge 51 (JERITH00590051) on Town Highway 59, crossing The Creek, Jericho, Vermont

    USGS Publications Warehouse

    Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure JERITH00590051 on Town Highway 59 crossing The Creek, Jericho, 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 (Federal Highway Administration, 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 and the Champlain section of the St. Lawrence physiographic province in northwestern Vermont. The 10.9-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 left and right overbanks, upstream and downstream of the bridge while the immediate banks have dense woody vegetation. In the study area, The Creek has a sinuous channel with a slope of approximately 0.004 ft/ft, an average channel top width of 45 ft and an average bank height of 6 ft. The channel bed material ranges from silt to cobble with a median grain size (D50) of 58.6 mm (0.192 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 3, 1996, indicated that the reach was stable. The Town Highway 59 crossing of The Creek is a 33-ft-long, two-lane bridge consisting of a 28-foot steel-stringer span (Vermont Agency of Transportation, written communication, December 11, 1995). The opening length of the structure parallel to the bridge face is 26 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the computed opening

  11. Level II scour analysis for Bridge 45 (BRNETH00070045) on Town Highway 7, crossing the Stevens River, Barnet, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Hammond, Robert E.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BRNETH00070045 on Town Highway 7 crossing the Stevens River, Barnet, 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 41.5-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream and pasture downstream of the bridge while the immediate banks have dense woody vegetation. In the study area, the Stevens River has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 100 ft and an average bank height of 17 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 105 mm (0.344 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 22, 1995, indicated that the reach was stable. The Town Highway 7 crossing of the Stevens River is a 37-ft-long, two-lane bridge consisting of one 34-foot concrete slab span (Vermont Agency of Transportation, written communication, March 16, 1995). The opening length of the structure parallel to the bridge face is 33 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is 20 degrees. The only scour protection measure at

  12. 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

  13. Level II scour analysis for Bridge 15 (BOLTTH00150015) on Town Highway 15, crossing Joiner Brook, Bolton, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BOLTTH00150015 on Town Highway 15 crossing Joiner Brook, Bolton, 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. The site is in the Green Mountain section of the New England physiographic province in north central Vermont. The 9.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture (lawn) downstream of the bridge and on the upstream right bank. The surface cover on the upstream left bank is shrub and brushland. In the study area, Joiner Brook has an incised, straight channel with a slope of approximately 0.01 ft/ft, an average channel top width of 61 ft and an average bank height of 7 ft. The channel bed material ranges from gravel to cobble with a median grain size (D50) of 43.6 mm (0.143 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 27, 1996, indicated that the reach was stable. The Town Highway 15 crossing of Joiner Brook is a 39-ft-long, two-lane bridge consisting of one 36-foot concrete tee-beam span (Vermont Agency of Transportation, written communication, November 3, 1995). The opening length of the structure parallel to the bridge face is 34.6 ft. The bridge is supported by nearly vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is zero degrees. A scour hole 1.5 ft deeper than the

  14. 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

    This report provides the results of a detailed Level II analysis of scour potential at structure JERITH00350031 on Town Highway 35 crossing Mill Brook, Jericho, 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, gathered 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 and the Champlain section of the St. Lawrence physiographic province in northwestern Vermont. The 15.7-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream of the bridge. The downstream left overbank is pasture. The downstream right overbank is brushland. In the study area, the Mill Brook has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 117 ft and an average bank height of 11 ft. The channel bed material ranges from gravel to boulders with a median grain size (D50) of 81.1 mm (0.266 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 3, 1996, indicated that the reach was laterally unstable. The Town Highway 35 crossing of the Mill Brook is a 53-ft-long, one-lane bridge consisting of a 50-foot steel-beam span with a wooden deck (Vermont Agency of Transportation, written communication, November 30, 1995). The opening length of the structure parallel to the bridge face is 48 ft. The bridge is supported by a vertical, concrete abutment with wingwalls on the left. On the right, the abutment and wingwalls

  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 Detail, Vertical Cross Bracing-End Detail - Cumberland Covered Bridge, Spanning Mississinewa River, Matthews, Grant County, IN

  16. Level II scour analysis for Bridge 12 (HUNTTH00010012) on Town Highway 001, crossing Brush Brook, Huntington, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Wild, Emily C.

    1997-01-01

    frequency data contained in the Flood Insurance Study for the Town of Huntington (U.S. Department of Housing and Urban Development, 1978). The site is in the Green Mountain section of the New England physiographic province in central Vermont. The 9.19-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture while the immediate banks have some woody vegetation. In the study area, the Brush Brook has a sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 62 ft and an average bank height of 5 ft. The channel bed material ranges from gravel to cobble with a median grain size (D50) of 100.0 mm (0.328 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 25, 1996, indicated that the reach was stable. The Town Highway 1 crossing of Brush Brook is a 64-ft-long, two-lane bridge consisting of one 62-foot steel-stringer span (Vermont Agency of Transportation, written communication, November 30, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is 6 degrees. Channel scour 2.2 ft deeper than the mean thalweg depth was observed along the upstream right bank and along the base of the spill-through protection for the right abutment during the Level I assessment. Scour protection measured at the site was type-2 stone fill (less than 36 inches diameter) along the upstream left and right banks and in front of all four wingwalls. In front of the abutments, there was type-3 stone fill (less than 48 inches diameter) forming a spill-through slope. 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

  17. Level II scour analysis for Bridge 45a (BRIDUS00040045a) on U.S. Route 4, crossing Ottauquechee River, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BRIDUS00040045a on U.S.. Route 4 crossing the 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). 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 province of central Vermont in the town of Bridgewater. The 72.1-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the overbank areas are lawn or pasture with a few residences. The immediate channel banks have moderately dense woody vegetation. In the study area, the Ottauquechee River has a sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 81 ft and an average channel depth of 3 ft. The predominant channel bed materials are gravel and cobble (D50 is 54.9 mm or 0.180 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 26, 1994, indicated that the reach was stable. The U.S. Route 4 crossing of the Ottauquechee Riveris a 172-ft-long, two-lane bridge consisting of three steel-beam spans supported by spill-through abutments and two concrete piers (Vermont Agency of Transportation, written commun., August 25, 1994). The abutment and road approaches are protected by type-2 stone fill (less than 36 inches diameter). The North Branch of the Ottauquechee River joins the Ottauquechee River approximately 200 feet upstream of the bridge on the main branch’s left bank. The channel approach to the bridge has a mild bend with the bridge skewed 15

  18. Level II scour analysis for Bridge 31 (BRISTH00030031) on Town Highway 3, crossing the New Haven River, Bristol, Vermont

    USGS Publications Warehouse

    Degnan, James R.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BRISTH00030031 on Town Highway 3 crossing the New Haven River, Bristol, 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 west-central, western Vermont. The 69.1-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 left overbank which has closely spaced houses with lawns. In the study area, the New Haven River has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 136 ft and an average bank height of 13 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 233 mm (0.765 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 20, 1996, indicated that the reach was stable. The Town Highway 3 crossing of the New Haven River is a 105-ft-long, two-lane bridge consisting of a 101-ft-long pony truss span (Vermont Agency of Transportation, written communication, November 30, 1995). The opening length of the structure parallel to the bridge face is 98 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 60 degrees to the opening, with no opening-skew-to-roadway. A local scour hole 3 ft deeper than the mean thalweg

  19. 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…

  20. The Bridge: A Journal of Cross-Cultural Affairs; Summer 1976, Volume 1, Number 2.

    ERIC Educational Resources Information Center

    Reynolds, Collins, Ed.

    This quarterly newsletter, announced in RIE on a one-time basis, investigates a different area of the world in each issue. It is intended for use by businessmen, government officials, and educators. Typical issues include feature articles highlighting problems of crossing cultural boundaries to teach, do business, or cope overseas and at home;…

  1. Bridging Spaces: Cross-Cultural Perspectives on Promoting Positive Online Learning Experiences

    ERIC Educational Resources Information Center

    Luyt, Ilka

    2013-01-01

    The globalization of online courses has transformed online learning into cross-cultural learning spaces. Students from non-English backgrounds are enrolling in credit-bearing courses and must adjust their thinking and writing to adapt to online practices. Online courses have as their aim the construction of knowledge, but students' perceptions of…

  2. 77 FR 18296 - Notice of U.S. Hosting of 2012-2013 United States-Mexico Binational Bridges and Border Crossings...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ... Mexican Affairs' Border Affairs Unit via email at WHA-BorderAffairs@state.gov or by mail at WHA/MEX--Room... Palazzolo of the Office of Mexican Affairs' Border Affairs Unit at 202-647-1202 or via email at WH-Border... of U.S. Hosting of 2012-2013 United States-Mexico Binational Bridges and Border Crossings...

  3. 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

  4. Oblique section 3-D reconstruction of relaxed insect flight muscle reveals the cross-bridge lattice in helical registration.

    PubMed Central

    Schmitz, H; Lucaveche, C; Reedy, M K; Taylor, K A

    1994-01-01

    In this work we examined the arrangement of cross-bridges on the surface of myosin filaments in the A-band of Lethocerus flight muscle. Muscle fibers were fixed using the tannic-acid-uranyl-acetate, ("TAURAC") procedure. This new procedure provides remarkably good preservation of native features in relaxed insect flight muscle. We computed 3-D reconstructions from single images of oblique transverse sections. The reconstructions reveal a square profile of the averaged myosin filaments in cross section view, resulting from the symmetrical arrangement of four pairs of myosin heads in each 14.5-nm repeat along the filament. The square profiles form a very regular right-handed helical arrangement along the surface of the myosin filament. Furthermore, TAURAC fixation traps a near complete 38.7 nm labeling of the thin filaments in relaxed muscle marking the left-handed helix of actin targets surrounding the thick filaments. These features observed in an averaged reconstruction encompassing nearly an entire myofibril indicate that the myosin heads, even in relaxed muscle, are in excellent helical register in the A-band. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 PMID:7819494

  5. Cross-linked sulfonated aromatic ionomers via SO2 bridges: Conductivity properties

    NASA Astrophysics Data System (ADS)

    Di Vona, M. L.; Pasquini, L.; Narducci, R.; Pelzer, K.; Donnadio, A.; Casciola, M.; Knauth, P.

    2013-12-01

    The proton conductivity of SPEEK membranes in situ cross-linked by thermal treatment at 180 °C for various times was investigated by impedance spectroscopy. The conductivity measurements were made on fully humidified membranes between 25 and 65 °C and on membranes exposed to different relative humidity between 80 and 140 °C. The Ionic Exchange Capacity (IEC) was determined by acid-base titration and the water uptake by gravimetry. The proton conductivity was determined as function of temperature, IEC, degree of cross-linking and hydration number. A curve of proton conductivity vs. hydration number allows predicting that in order to reach a value of 0.1 S/cm at 100 °C a hydration number above 20 is necessary. The measured conductivity at this temperature is 0.16 S/cm for a hydration number of 60.

  6. Level II scour analysis for Bridge 29 (CRAFTH00550029) on Town Highway 55, crossing the Black River, Craftsbury, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Degnan, James R.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure CRAFTH00550029 on town highway 55 crossing the Black River, Craftsbury, 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 of north-central Vermont in the town of Craftsbury. The 24.7-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the banks have woody vegetation coverage except for the upstream left bank and the downstream right bank, which have more brush cover than trees. In the study area, the Black River has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 41 ft and an average channel depth of 5.5 ft. The predominant channel bed material is sand and gravel (D50 is 44.7 mm or 0.147 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 55 crossing of the Black Riveris a 32-ft-long, one-lane bridge consisting of one 28-foot span steel stringer superstructure with a timber deck (Vermont Agency of Transportation, written communication, August 4, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 40 degrees to the opening while the opening-skew-to-roadway is 10 degrees. A scour hole 2 ft deeper than the mean thalweg depth was

  7. Level II scour analysis for Bridge 20 (BRISTH00270020) on Town Highway 27, crossing Little Notch Brook, Bristol, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BRISTH00270020 on Town Highway 27 crossing Little Notch Brook, Bristol, 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 west-central Vermont. The 8.43-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover consists of pasture with trees, shrubs, and brush along the road embankments and the stream banks, except for the downstream left overbank area. Surface cover on the downstream left overbank is forest with dense undergrowth consisting of vines, shrubs, and brush. In the study area, Little Notch Brook has a sinuous channel with a slope of approximately 0.006 ft/ft, an average channel top width of 47 feet and an average bank height of 3 feet. The predominant channel bed materials are gravel and cobbles with a median grain size (D50) of 66.0 mm (0.216 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 19, 1995, indicated that the reach was stable. The Town Highway 27 crossing of Little Notch Brook is a 48-ft-long, one-lane bridge consisting of one 45-foot steel pony-truss span (Vermont Agency of Transportation, written communication, November 30, 1995). The opening length of the structure parallel to the bridge face is 42.8 feet. The bridge is supported by vertical, concrete abutments

  8. Level II scour analysis for Bridge 19 (SHEFTH00440019) on Town Highway 44, crossing Trout Brook, Sheffield, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Medalie, Laura

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure SHEFTH00440019 on Town Highway 44 crossing Trout Brook, 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 3.0-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is grass on the upstream and downstream right overbanks, while the immediate banks have dense woody vegetation. The surface cover of the upstream and downstream left overbanks is shrub and brushland. In the study area, Trout Brook has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 45 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 116 mm (0.381 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 31, 1995, indicated that the reach was stable. The Town Highway 44 crossing of Trout Brook is a 24-ft-long, one-lane bridge consisting of a 22-foot steel-stringer span (Vermont Agency of Transportation, written communication, March 28, 1994). The opening length of the structure parallel to the bridge face is 19.8 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening

  9. Level II scour analysis for Bridge 43 (BENNCYDEPO0043) on Depot Street, crossing the Walloomsac River, Bennington, 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 BENNCYDEPO0043 on the Depot Street crossing of the Walloomsac River, Bennington, 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 southwestern Vermont. The 30.1-mi2 drainage area is a predominantly rural and forested basin. The bridge site is located within an urban setting in the Town of Bennington with buildings and parking lots on overbanks. In the study area, the Walloomsac River has a straight channel with constructed channel banks through much of the reach. The channel is located on a delta and has a slope of approximately 0.02 ft/ft, an average channel top width of 48 ft and an average bank height of 6 ft. The predominant channel bed material is cobble with a median grain size (D50) of 108 mm (0.356 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 5, 1996, indicated that the reach was stable. The Depot Street crossing of the Walloomsac River is a 46-ft-long, two-lane bridge consisting of one 40-foot concrete span (Vermont Agency of Transportation, written communication, December 13, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 5 degrees to the opening and the opening-skew-to-roadway is 15 degrees. Scour countermeasures at the site include type-2 stone fill (less than 36

  10. Level II scour analysis for Bridge 16 (CHESVT01030016) on State Route 103, crossing the Williams River, Chester, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Hammond, Robert E.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure CHESVT01030016 on State Route 103 crossing the 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 15.1-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture except for the downstream right overbank which is forested. In the study area, the Williams River has an incised, straight channel with a slope of approximately 0.008 ft/ft, an average channel top width of 56 ft and an average bank height of 6 ft. The channel bed material ranges from gravel to cobbles with a median grain size (D50) of 67.5 mm (0.222 ft). The geomorphic assessment at the time of the Level I and Level II site visit on September 16, 1996, indicated that the reach was stable. The State Route 103 crossing of the Williams River is a 162-ft-long, two-lane bridge consisting of three steel-beam spans (Vermont Agency of Transportation, written communication, March 13, 1995). The opening length of the structure parallel to the bridge face is 157.7 ft.The bridge is supported by vertical, concrete abutments and piers with no wingwalls. The channel is skewed approximately 55 degrees to the opening while the opening-skew-to-roadway is also 55 degrees. The scour protection measures at the site included

  11. Level II scour analysis for Bridge 41 (ROCKTH00390041) on Town Highway 39, crossing the Saxtons River, Rockingham, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Degnan, James R.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ROCKTH00390041 on Town Highway 39 crossing the Saxtons River, Rockingham, 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 57.4-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover consists of forest on the left bank and pasture with some trees on the right bank. In the study area, the Saxtons River has an sinuous channel with a slope of approximately 0.009 ft/ft, an average channel top width of 112 ft and an average bank height of 10 ft. The channel bed material ranges from sand to cobbles with a median grain size (D50) of 103 mm (0.339 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 15, 1996, indicated that the reach was laterally unstable. There are wide point bars, cut-banks with fallen trees, and areas of localized channel scour along the left bank, where there is bedrock exposure at the surface. The Town Highway 39 crossing of the Saxtons River is an 85-ft-long, one-lane bridge consisting of one 82-foot steel-beam span (Vermont Agency of Transportation, written communication, March 31, 1995). The bridge is supported by vertical, concrete abutments without wingwalls. The channel is skewed approximately 30 degrees to the opening while the opening

  12. Level II scour analysis for Bridge 20 (GRAFTH00010020) on Town Highway 1, crossing the Saxtons River, Grafton Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Burns, Ronda L.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure GRAFTH00010020 on Town Highway 1 crossing the Saxtons River, Grafton, 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 33.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream of the bridge and shrub and brush downstream. In the study area, the Saxtons River has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 97 ft and an average bank height of 2 ft. The predominant channel bed material is gravel with a median grain size (D50) of 58.6 mm (0.192 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 21, 1996, indicated that the reach was laterally unstable due to distinctive cut bank development on the upstream right bank and point bar development on the upstream left bank and downstream right bank. The Town Highway 1 crossing of the Saxtons River is a 191-ft-long, two-lane bridge consisting of three steel-beam spans (Vermont Agency of Transportation, written communication, March 29, 1995). The bridge is supported by vertical, concrete abutments with spill-through embankments and two piers. The channel is skewed approximately 40 degrees to the opening. The opening-skew-to-roadway is 45

  13. Level II scour analysis for Bridge 44 (LINCTH00330044) on Town Highway 33, crossing the New Haven River, Lincoln, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Wild, Emily C.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure LINCTH00330044 on Town Highway 33 crossing the New Haven River, Lincoln, 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 west-central Vermont. The 6.3-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 New Haven River has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 56 ft and an average bank height of 6 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 101.9 mm (0.334 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 10, 1996, indicated that the reach was stable.The Town Highway 33 crossing of the New Haven River is a 33-ft-long, one-lane bridge consisting of one 31-foot timber-beam span (Vermont Agency of Transportation, written communication, December 14, 1995). The opening length of the structure parallel to the bridge face is 29.3 ft. The bridge is supported by vertical, wood-beam crib abutments with wingwalls. The channel is skewed approximately 25 degrees to the opening while the opening-skew-to-roadway is zero degrees.A scour hole 1.0 ft deeper than the mean thalweg depth was observed along the right abutment during the Level I assessment. The

  14. Level II scour analysis for Bridge 34 (WWINTH00370034) on Town Highway 37, crossing Mill Brook, West Windsor, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure WWINTH00370034 on Town Highway 37 crossing Mill Brook, West Windsor, 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. The site is in the New England Upland section of the New England physiographic province in east-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 pasture except for the upstream left bank where there is mostly shrubs and brush. In the study area, Mill Brook has a sinuous channel with a slope of approximately 0.003 ft/ ft, an average channel top width of 52 ft and an average bank height of 5 ft. The channel bed material ranges from sand to cobbles with a median grain size (D50) of 43.4 mm (0.142 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 5, 1996, indicated that the reach was laterally unstable. Point bars were observed upstream and downstream of this site. Furthermore, slip failure of the bank material was noted downstream at a cut-bank on the left side of the channel across from a point bar. The Town Highway 37 crossing of Mill Brook is a 37-ft-long, one-lane covered bridge consisting of one 32-foot wood thru-truss span (Vermont Agency of Transportation, written communication, March 23, 1995). The opening length of the structure parallel to the bridge face is 29.6 ft. The bridge is supported by vertical, laid-up stone abutment walls with

  15. Level II scour analysis for Bridge 23 (GLOVTH00410023) on Town Highway 41, crossing Sherburne Brook, Glover, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Boehmler, Erick M.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure GLOVTH00410023 on Town Highway 41 crossing Sherburne Brook, Glover, 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 northern Vermont. The 2.57-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is primarily forest with small areas of lawn and a home on the right overbank and a gravel roadway along the upstream left bank. In the study area, Sherburne Brook has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 33 ft and an average bank height of 6 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 57.3 mm (0.188 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 24, 1994, indicated that the reach was stable. The Town Highway 41 crossing of Sherburne Brook is a 24-ft-long, one-lane bridge consisting of one 21-foot steel-beam span with a timber deck (Vermont Agency of Transportation, written communication, August 4, 1994). The opening length of the structure parallel to the bridge face is 20.3 ft. The bridge is supported by vertical, granite block abutments. The channel is skewed approximately 55 degrees to the opening while the measured opening-skew-to-roadway is 30 degrees. One foot

  16. Level II scour analysis for Bridge 9 (BLOOVT01020009) on State Route 102, crossing the Nulhegan River, Bloomfield, Vermont

    USGS Publications Warehouse

    Ayotte, Joseph D.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BLOOVT01020009 on State Route 102 crossing the Nulhegan River, Bloomfield, 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 144-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest except for the downstream right bank area which is shrub and brush land. The Nulhegan River flows into the Connecticut River 210 feet downstream of this bridge. In the study area, the Nulhegan River has an incised, sinuous channel with a slope of approximately 0.005 ft/ft, an average channel top width of 164 ft and an average channel depth of 5 ft. The predominant channel bed material is cobble with a median grain size (D50) of 152 mm (0.498 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 6, 1995, indicated that the reach was laterally unstable. This was due to numerous point bars and side bars indicating an unstable thalweg. The State Route 102 crossing of the Nulhegan River is a 134-ft-long, two-lane bridge consisting of one 130-foot steel-truss span (Vermont Agency of Transportation, written communication, August 4, 1994). The field measured clear span was 131.6 ft. The bridge is supported by vertical, concrete abutments with rip-rapped spill-through slopes. The

  17. Level II scour analysis for Bridge 41 (WODSTH00750041) on Town Highway 75, crossing Happy Valley Brook, Woodstock, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure WODSTH00750041 on town highway 75 crossing Happy Valley Brook, Woodstock, 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 of east-central Vermont. The 3.45-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is brush with scattered trees. In the study area, Happy Valley Brook has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 23 ft and an average channel depth of 5 ft. The predominant channel bed materials are gravel and cobble with a median grain size (D50) of 82.8 mm (0.272 ft). The geomorphic assessment at the time of the Level II site visits on September 13, 1994 and December 14, 1994, indicated that the reach was degrading. Five logs are embedded across the channel under the bridge in an attempt to prevent further degradation (see Figures 5 and 6). The town highway 75 crossing of Happy Valley Brook is a 27-ft-long, two-lane bridge consisting of one 25-foot steel-beam span. The clear span is 17 ft. (Vermont Agency of Transportation, written communication, August 3, 1994). The bridge is supported by vertical, stone abutments with wingwalls. The channel is skewed approximately 40 degrees to the opening and the opening-skew-to-roadway is also 40 degrees. Additional

  18. 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

  19. Level II scour analysis for Bridge 12 (SUNDFLR0030012) on Forest Land Road 3, crossing Roaring Branch Brook, Sunderland, 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 SUNDFLR0030012 on Forest Land Road (FLR) 3 (FAS 114) crossing Roaring Branch Brook, Sunderland, 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 southwestern Vermont. The 4.93-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is dense forest along the left bank and primarily shrubs and trees along the right bank, both upstream and downstream of the bridge. In the study area, Roaring Branch Brook has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 33 ft and an average bank height of 4 ft. The channel bed material ranges from cobble to bedrock with a median grain size (D50) of 139 mm (0.457 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 30, 1996, indicated that the reach was stable. Forest Land Road 3 (FAS 114) crossing of Roaring Branch Brook is a 37-ft-long, two-lane bridge consisting of one 35-foot steel-beam span (Vermont Agency of Transportation, written communication, December 14, 1995). 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 15 degrees. The scour protection measures at the site included

  20. Level II scour analysis for Bridge 28 (ROCHTH00370028) on Town Highway 37, crossing Brandon Brook, Rochester, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Weber, Matthew A.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ROCHTH00370028 on Town Highway 37 crossing Brandon Brook, Rochester, 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 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 8.0-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 upstream left overbank although the immediate banks have dense woody vegetation. The upstream right overbank and downstream left and right overbanks are forested. In the study area, the Brandon Brook has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 44 ft and an average bank height of 7 ft. The channel bed material ranges from gravel to cobbles with a median grain size (D50) of 84.2 mm (0.276 ft). The geomorphic assessment at the time of the Level I site visit on April 12, 1995 and Level II site visit on July 8, 1996, indicated that the reach was stable. The Town Highway 37 crossing of the Brandon Brook is a 33-ft-long, one-lane bridge consisting of a 31-foot timber-stringer span (Vermont Agency of Transportation, written communication, March 22, 1995). The opening length of the structure parallel to the bridge face is 29.6 ft. The bridge is supported by vertical, timber log cribbing abutments with wingwalls. The channel is skewed approximately 5 degrees to the opening while the computed opening-skew-to-roadway is zero

  1. Level II scour analysis for Bridge 144 (ROCHVT01000144) on State Route 100, crossing the White River, Rochester, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Wild, Emily C.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ROCHVT01000144 on State Route 100 crossing the White River, Rochester, 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 68.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture with forest on the valley walls. In the study area, the White River has a meandering channel with a slope of approximately 0.003 ft/ft, an average channel top width of 119 ft and an average channel depth of 4 ft. The predominant channel bed material is gravel and cobbles with a median grain size (D50) of 72.5 mm (0.238 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 22, 1996, indicated that the reach was laterally unstable due to a cut-bank present on the upstream left bank and wide point bars upstream and downstream in the vicinity of this site. The State Route 100 crossing of the White Riveris a 103-ft-long, two-lane bridge consisting of one 101-foot steel-beam span (Vermont Agency of Transportation, written communication, March 8, 1995). The bridge is supported by vertical, concrete abutment walls with spill-through embankments in front of each abutment wall and no wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-toroadway is

  2. Level II scour analysis for Bridge 34 (ROCHTH00210034) on Town Highway 21, crossing the White River, Rochester, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Degnan, James

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ROCHTH00210034 on Town Highway 21 crossing the White River, Rochester, 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, obtained 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 74.8-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is suburban on the upstream and downstream left overbanks, though brush prevails along the immediate banks. On the upstream and downstream right overbanks, the surface cover is pasture with brush and trees along the immediate banks.In the study area, the White River has an incised, straight channel with a slope of approximately 0.002 ft/ft, an average channel top width of 102 ft and an average bank height of 5 ft. The channel bed material ranges from sand to cobble with a median grain size (D50) of 74.4 mm (0.244 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 23, 1996, indicated that the reach was stable.The Town Highway 21 crossing of the White River is a 72-ft-long, two-lane bridge consisting of 70-foot steel stringer span (Vermont Agency of Transportation, written communication, March 22, 1995). The opening length of the structure parallel to the bridge face is 67.0 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15

  3. Level II scour analysis for Bridge 32 (HUNTTH00220032) on Town Highway 22, crossing Brush Brook, Huntington, 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 HUNTTH00220032 on Town Highway 22 crossing Brush Brook, Huntington, 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 5.7-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 overbank which is pasture. In the study area, Brush Brook has an incised, straight channel with a slope of approximately 0.05 ft/ft, an average channel top width of 58 ft and an average bank height of 6 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 127 mm (0.416 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 25, 1996, indicated that the reach was stable. The Town Highway 22 crossing of Brush Brook is a 36-ft-long, one-lane bridge consisting of one 34-foot steel-beam span and a timber deck (Vermont Agency of Transportation, written communication, December 12, 1995). The opening length of the structure parallel to the bridge face is 35.7 ft. The bridge is supported by vertical, concrete abutments with wingwalls on the left. The channel is skewed approximately 50 degrees to the opening while the measured opening-skew-to-roadway is 15 degrees. A scour hole 1.0 ft deeper than the mean thalweg depth was

  4. Level II scour analysis for Bridge 38 (JERITH0020038) on Town Highway 20, crossing the Lee River, Jericho, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Degnan, James R.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure JERITH00200038 on Town Highway 20 crossing the Lee River, Jericho, 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, obtained 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 and the Champlain section of the St. Lawrence physiographic province in northwestern Vermont. The 12.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover on the upstream and downstream right overbank is pasture while the immediate banks have dense woody vegetation. The surface cover on the upstream and downstream left overbank is forested. In the study area, the Lee River has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 89 ft and an average bank height of 14 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 45.9 mm (0.151 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 20 crossing of the Lee River is a 49-ft-long, one-lane bridge consisting of a steel through truss span (Vermont Agency of Transportation, written communication, December 12, 1995). The opening length of the structure parallel to the bridge face is 44 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is

  5. Level II scour analysis for Bridge 28 (CAMBTH00460028) on Town Highway 46, crossing the Seymour River, Cambridge, 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 CAMBTH00460028 on Town Highway 46 crossing the Seymour River, Cambridge, 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 northwestern Vermont. The 9.94-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture while the immediate banks have dense woody vegetation. In the study area, the Seymour River has an incised, straight channel with a slope of approximately 0.02 ft/ft, an average channel top width of 81 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 62.0 mm (0.204 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 11, 1995, indicated that the reach was stable. The Town Highway 46 crossing of the Seymour River is a 38-ft-long, one-lane bridge consisting of one 33-foot steel-beam span (Vermont Agency of Transportation, written communication, March 8, 1995). The opening length of the structure parallel to the bridge face is 30.6 ft.The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 5 degrees to the opening while the measured opening-skew-to-roadway is 10 degrees. A scour hole 0.2 ft deeper than the mean thalweg depth was observed along the

  6. 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

  7. Level II scour analysis for Bridge 67 (MTHOTH00120067) on Town Highway 12, crossing Freeman Brook, Mount Holly, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Severance, Timothy

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure MTHOTH00120067 on Town Highway 12 crossing Freeman Brook, Mount Holly, 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. The site is in the Green Mountain section of the New England physiographic province in south-central Vermont. The 11.4-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forested. In the study area, Freeman Brook has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 51 ft and an average bank height of 6 ft. The channel bed material ranges from sand to boulders with a median grain size (D50) of 55.7 mm (0.183 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 5, 1995, indicated that the reach was stable. The Town Highway 12 crossing of Freeman Brook is a 34-ft-long, two-lane bridge consisting of a 30-foot prestressed concrete-slab span (Vermont Agency of Transportation, written communication, March 15, 1995). The opening length of the structure parallel to the bridge face is 29.5 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 50 degrees to the opening while the opening-skew-to-roadway is 15 degrees. Along the upstream right wingwall, the right abutment and the downstream right wingwall, a scour hole approximately 1.0 to 2.0 ft deeper than the mean thalweg

  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 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

  10. Level II scour analysis for Bridge 17 (LYNDTH00020017) on Town Highway 2, crossing Hawkins Brook, Lyndon, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Medalie, Laura

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure LYNDTH00020017 on Town Highway 2 crossing Hawkins Brook, Lyndon, 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 northeastern Vermont. The 7.7-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest on the left and right upstream overbanks. The downstream left and right overbanks are brushland.In the study area, Hawkins Brook has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 78 ft and an average bank height of 7.3 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 46.6 mm (0.153 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 4, 1995, indicated that the reach was laterally unstable with the presence of point bars and side bars.The Town Highway 2 crossing of Hawkins Brook is a 49-ft-long, two-lane bridge consisting of a 46-foot steel-stringer span (Vermont Agency of Transportation, written communication, March 27, 1995). The opening length of the structure parallel to the bridge face is 43 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 45 degrees to the opening while the computed opening-skew-to-roadway is zero

  11. Level II scour analysis for Bridge 36 (DUXBTH00040036) on Town Highway 4, crossing Crossett Brook, Duxbury, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Degnan, James R.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure DUXBTH00040036 on Town Highway 4 crossing the Crossett Brook, Duxbury, 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 4.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover on the upstream left overbank is pasture. The upstream and downstream right overbanks are forested. The downstream left overbank is brushland, while the immediate banks have dense woody vegetation.In the study area, the Crossett Brook has an incised, sinuous channel with a slope of approximately 0.006 ft/ft, an average channel top width of 55 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 51.6 mm (0.169 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 1, 1996, indicated that the reach was stable.The Town Highway 4 crossing of the Crossett Brook is a 29-ft-long, two-lane bridge consisting of a 26-foot concrete slab span (Vermont Agency of Transportation, written communication, October 13, 1995). The opening length of the structure parallel to the bridge face is 26 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 35 degrees to the opening while

  12. Level II scour analysis for Bridge 31 (HUNTTH00220031) on Town Highway 22, crossing Brush Brook, Huntington, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Degnan, James R.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure HUNTTH00220031 on Town Highway 22 crossing Brush Brook, Huntington, 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, obtained 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 west-central Vermont. The 5.01-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover consists of trees and brush. In the study area, Brush Brook has an incised, straight channel with a slope of approximately 0.06 ft/ft, an average channel top width of 44 ft and an average bank height of 4 ft. The channel bed material ranges from boulder to gravel with a median grain size (D50) of 107.0 mm (0.352 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 25, 1996, indicated that the reach was stable. The Town Highway 22 crossing of Brush Brook is a 34-ft-long, one-lane bridge consisting of one 30-foot steel I-beam span (Vermont Agency of Transportation, written communication, November 30, 1995). The opening length of the structure parallel to the bridge face is 31.2 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15 degrees to the opening while the computed opening-skew-to-roadway is 10 degrees. The VTAOT computed opening-skewto-roadway is 2 degrees. A scour hole 1.0 ft deeper than the mean thalweg depth was

  13. Level II scour analysis for Bridge 16 (BURKTH00070016) on Town Highway 7, crossing Dish Mill Brook, Burke, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Severance, Tim

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BURKTH00070016 on Town Highway 7 crossing Dish Mill Brook, 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 (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 6.0-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 left bank upstream which is brushland. In the study area, Dish Mill Brook has an incised, sinuous channel with a slope of approximately 0.04 ft/ft, an average channel top width of 40 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 94.1 mm (0.309 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 7, 1995, indicated that the reach was stable. The Town Highway 7 crossing of Dish Mill Brook is a 28-ft-long, two-lane bridge consisting of one 24-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 24.8 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 35 degrees to the opening while the computed opening-skew-to-roadway is 35 degrees. A scour hole 1.0 ft deeper than the mean thalweg depth was observed along the left and right

  14. Level II scour analysis for Bridge 22 (BRADTH00270022) on Town Highway 27, crossing the Waits River, Bradford, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Ivanoff, Michael A.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BRADTH00270022 on Town Highway 27 crossing the Waits River, Bradford, 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, obtained 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 153-mi2 drainage area is in a predominantly rural and forested basin. However, in the vicinity of the study site, the upstream and downstream left banks are suburban and the upstream and downstream right banks are shrub and brushland. In the study area, the Waits River has an incised, sinuous channel with a slope of approximately 0.0002 ft/ft, an average channel top width of 125 ft and an average bank height of 4 ft. The channel bed material ranges from silt and clay to bedrock with a median grain size (D50) of 0.393 mm (0.00129 ft). The geomorphic assessment at the time of the Level I and Level II site visit on September 7, 1995, indicated that the reach was stable. The Town Highway 27 crossing of the Waits River is a 109-ft-long, one-lane bridge consisting of a 104-ft steel-truss span (Vermont Agency of Transportation, written communication, March 16, 1995). The opening length of the structure parallel to the bridge face is 99.2 ft. The bridge is supported by vertical, laid-up stone abutments. The channel is skewed approximately 30 degrees to the opening while the opening-skew-to-roadway is zero degrees. No evidence of scour was observed during the Level I assessment

  15. Level II scour analysis for Bridge 53 (CAMBTH00750053) on Town Highway 75, crossing the Brewster River, Cambridge, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Hammond, Robert E.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure CAMBTH00750053 on Town Highway 75 crossing the Brewster River, Cambridge, 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 northwestern Vermont. The 4.30-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest, except for the downstream right overbank area which has a barn surrounded by grass and shrubs. In the study area, the Brewster River has an incised, straight channel with a slope of approximately 0.05 ft/ft, an average channel top width of 62 ft and an average bank height of 12 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 84.4 mm (0.277 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 11, 1995, indicated that the reach was stable. The Town Highway 75 crossing of the Brewster River is a 28-ft-long, two-lane bridge consisting of one 24-foot concrete tee-beam span (Vermont Agency of Transportation, written communication, March 8, 1995). The opening length of the structure parallel to the bridge face is 22.4 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 40 degrees to the opening while the opening-skew-to-roadway as surveyed is 10 degrees. A scour hole 1 ft

  16. Level II scour analysis for Bridge 8 (NEWFTH00010008) on Town Highway 1, crossing Wardsboro Brook, Newfane, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Degnan, James

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure NEWFTH00010008 on Town Highway 1 crossing Wardsboro Brook, Newfane, 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 (Federal Highway Administration, 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 southestern Vermont. The 6.91-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest on the upstream right overbank and downstream left and right overbanks. The surface cover on the upstream left overbank is pasture. In the study area, Wardsboro Brook has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 63 ft and an average bank height of 9 ft. The channel bed material ranges from gravel to boulders with a median grain size (D50) of 95.4 mm (0.313 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 21, 1996, indicated that the reach was stable. The Town Highway 1 crossing of the Wardsboro Brook is a 32-ft-long, two-lane bridge consisting of a 26-foot concrete tee-beam span (Vermont Agency of Transportation, written communication, April 6, 1995). The opening length of the structure parallel to the bridge face is 26.7 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 45 degrees to the computed opening while the openingskew-to-roadway is 45 degrees

  17. Level II scour analysis for Bridge 42 (NEWFTH00350042) on Town Highway 35, crossing Stratton Hill Brook, Newfane, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Ivanoff, Michael A.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure NEWFTH00350042 on Town Highway 35 crossing Stratton Hill Brook, Newfane, 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. The site is in the New England Upland section of the New England physiographic province in southeastern Vermont. The 1.16-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forested. In the study area, Stratton Hill Brook has an incised, striaght channel with a slope of approximately 0.1 ft/ft, an average channel top width of 36 ft and an average bank height of 8 ft. The channel bed material ranges from gravel to boulders with a median grain size (D50) of 121 mm (0.396 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 20, 1996, indicated that the reach was stable. The Town Highway 34 crossing of Stratton Hill Brook is a 34-ft-long, one-lane bridge consisting of a 32-foot steel-beam span (Vermont Agency of Transportation, written communication, April 6, 1995). The opening length of the structure parallel to the bridge face is 30.8 ft. The bridge is supported by vertical, concrete abutments with upstream wingwalls. The channel is skewed approximately 20 degrees to the opening while the computed opening-skew-to-roadway is 15 degrees. During the Level I assessment, it was observed that the right abutment footing was exposed 1.5 feet. The only scour protection measure at the

  18. Level II scour analysis for Bridge 29 (DORSTH00100029) on Town Highway 10, crossing the Mettawee River, Dorset, Vermont

    USGS Publications Warehouse

    Wild, Emily C.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure DORSTH00100029 on Town Highway 10 crossing the Mettawee River, Dorset, 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 9.5-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest on the upstream left overbank and the upstream and downstream right overbanks. The downstream left overbank is pasture and brushland. In the study area, the Mettawee River has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 66 ft and an average bank height of 8 ft. The channel bed material ranges from gravel to boulders with a median grain size (D50) of 79.0 mm (0.259 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 5, 1996, indicated that the reach was stable. The Town Highway 10 crossing of the Mettawee River is a 26-ft-long, two-lane bridge consisting of a 24-ft steel-stringer span (Vermont Agency of Transportation, written communication, September 28, 1995). The opening length of the structure parallel to the bridge face is 24.1 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 45 degrees to the opening while the opening-skew-to-roadway is zero degrees. At the

  19. 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

    This report provides the results of a detailed Level II analysis of scour potential at structure STOWTH00430036 on Town Highway 43 crossing the Miller Brook, Stowe, 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 5.5-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, the Miller Brook has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 43 ft and an average bank height of 7 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 70.4 mm (0.231 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 15, 1996, indicated that the reach was stable. The Town Highway 43 crossing of the Miller Brook is a 24-ft-long, two-lane bridge consisting of one 21-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 21.5 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening and the computed opening-skew-to-roadway is also 10 degrees. The footing on the left abutment was exposed 2.5 ft and the footing on the right abutment was exposed 3.0 ft during

  20. The effect of thin filament activation on the attachment of weak binding cross-bridges: A two-dimensional x-ray diffraction study on single muscle fibers.

    PubMed

    Kraft, T; Xu, S; Brenner, B; Yu, L C

    1999-03-01

    To study possible structural changes in weak cross-bridge attachment to actin upon activation of the thin filament, two-dimensional (2D) x-ray diffraction patterns of skinned fibers from rabbit psoas muscle were recorded at low and high calcium concentration in the presence of saturating concentrations of MgATPgammaS, a nucleotide analog for weak binding states. We also studied 2D x-ray diffraction patterns recorded under relaxing conditions at an ionic strength above and below 50 mM, because it had been proposed from solution studies that reducing ionic strength below 50 mM also induces activation of the thin filament. For this project a novel preparation had to be established that allows recording of 2D x-ray diffraction patterns from single muscle fibers instead of natural fiber bundles. This was required to minimize substrate depletion or product accumulation within the fibers. When the calcium concentration was raised, the diffraction patterns recorded with MgATPgammaS revealed small changes in meridional reflections and layer line intensities that could be attributed in part to the effects of calcium binding to the thin filament (increase in I380, decrease in first actin layer line intensity, increase in I59) and in part to small structural changes of weakly attached cross-bridges (e.g., increase in I143 and I72). Calcium-induced small-scale structural rearrangements of cross-bridges weakly attached to actin in the presence of MgATPgammaS are consistent with our previous observation of reduced rate constants for attachment and detachment of cross-bridges with MgATPgammaS at high calcium. Yet, no evidence was found that weakly attached cross-bridges change their mode of attachment toward a stereospecific conformation when the actin filament is activated by adding calcium. Similarly, reducing ionic strength to less than 50 mM does not induce a transition from nonstereospecific to stereospecific attachment.

  1. 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

  2. An Accurate Method to Extract Specific Contact Resistivity Using Cross Bridge Kelvin Resistors,

    DTIC Science & Technology

    1985-01-01

    of current crowding. This pC is independent of I and w--in other words, only dependent on the material parameters such as sur- face doping, surface ... cleanliness and contact metal type. As contacts shrink, the total resistance contributed by the contact becomes pC 1A in the limit[8] which agrees with

  3. 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.

  4. Level II scour analysis for Bridge 42 (HARDELMSTR0042) on Elm Street, crossing Cooper Brook, Hardwick, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure HARDELMSTR0042 on Elm Street crossing Cooper Brook, Hardwick, 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 north-central Vermont. The 16.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the overbanks are primarily grass covered with some brush along the immediate channel banks except the upstream right bank and overbank which is forested and the downstream left overbank which has a lumberyard. In the study area, Cooper Brook has a sinuous channel with a slope of approximately 0.005 ft/ft, an average channel top width of 50 ft and an average channel depth of 6 ft. The predominant channel bed materials are sand and gravel with a median grain size (D50) of 1.25 mm (0.00409 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 24, 1995, indicated that the reach was stable. The Elm Street crossing of Cooper Brook is a 39-ft-long, two-lane bridge consisting of one 37-foot concrete span (Vermont Agency of Transportation, written communication, March 17, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 40 degrees to the opening while the opening-skew-to-roadway is 45 degrees. On August 17, 1995 the site was revisited to investigate

  5. Level II scour analysis for Bridge 15 (BRIDTH00220015) on Town Highway 22, crossing Dailey Hollow Branch, Bridgewater, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BRIDTH00220015 on town highway 22 crossing Dailey Hollow Branch, 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 1.73-mi2 drainage area is a predominantly rural and forested basin. In the vicinity of the study site, the left and right banks have dense tree cover. The upstream right bank of Dailey Hollow Branch is adjacent to town highway 22. In the study area, Dailey Hollow Branch has a sinuous channel with a slope of approximately 0.035 ft/ft, an average channel top width of 30 ft and an average channel depth of 4 ft. The predominant channel bed material is cobble with a median grain size (D50) of 108 mm (0.354 ft). The geomorphic assessment at the time of the Level I and Level II site visit on November 1 and 2, 1994, indicates that the reach is stable. The town highway 22 crossing of Dailey Hollow Branch is a 22-ft-long, one-lane bridge consisting of one 22-ft. steel-beam span (Vermont Agency of Transportation, written communication, August 24, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. Type-1 stone fill (less than 12 inches diameter) protects the left abutment, but it’s condition was reported as eroded. Type-2 stone fill (less than 36 inches diameter) protects the upstream left wingwall

  6. Level II scour analysis for Bridge 28 (HARDTH00300028) on Town Highway 30, crossing the Lamoille River, Hardwick, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Degnan, James R.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure HARDTH00300028 on town highway 30 crossing the Lamoille River, Hardwick, 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 north-central Vermont. The 63.7-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover upstream and on the downstream right is primarily pasture with some row crops. Trees line the immediate channel banks. The left bank downstream surface cover is primarily brush. In the study area, the Lamoille River has an incised, sinuous channel with a slope of approximately 0.002 ft/ft, an average channel top width of 76 ft and an average bank height of 6 ft. The predominant channel bed materials are gravel and cobble with a median grain size (D50) of 46.6 mm (0.153 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 25, 1995, indicated that the reach was laterally unstable. The site was revisited on August 21, 1995, after the August 5-6, 1995 flood on the Lamoille River. Findings from this follow-up visit are presented in Appendix G. The town highway 30 crossing of the Lamoille River is a 54-ft-long, one-lane bridge consisting of one 52-foot steel-beam span (Vermont Agency of Transportation, written communication, April 3, 1995). The bridge is supported by vertical, stone

  7. Level II scour analysis for Bridge 49 (WALLVT01030049) on State Highway 103, crossing Freeman Brook, Wallingford, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Severance, Timothy

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure WALLVT01030049 on State Highway 103 crossing Freeman Brook, Wallingford, 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 11.7-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture with trees and brush on the immediate banks except for the upstream left overbank which is tree covered. A levee composed of stone fill was constructed along the upstream left bank in order to keep flow from reaching the flood plain left (south) of the brook. In the study area, Freeman Brook has an incised, straight channel with a slope of approximately 0.02 ft/ft, an average channel top width of 56 ft and an average channel depth of 6 ft. The predominant channel bed materials are gravel and cobbles with a median grain size (D50) of 62.9 mm (0.206 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 10, 1995, indicated that the reach was stable. The State Highway 103 crossing of the Freeman Brook is a 54-ft-long, two-lane bridge consisting of one 50-foot concrete T-beam span (Vermont Agency of Transportation, written communication, March 15, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 25 degrees to

  8. Level II scour analysis for Bridge 25 (CRAFTH00220025) on Town Highway 22, crossing the Wild Branch Lamoille River, Craftsbury, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Ivanoff, Michael A.

    1996-01-01

    the abutments, the downstream left wingwall, and the downstream left bank. 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 0.0 to 2.5 ft. The worst-case contraction scour occurred at the incipient overtopping discharge, which was less than the 100-year discharge. Abutment scour ranged from 4.7 to 8.6 ft. The worst-case abutment scour also occurred 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). 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

  9. Level II scour analysis for Bridge 39 (LOWETH00080039) on Town Highway 8, crossing Potter Brook, Lowell, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Degnan, James R.

    1997-01-01

    A scour hole 2.0 feet deeper than the mean thalweg depth was observed along the left abutment during the Level I assessment. There were no scour protection measures evident at the site. 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 0.3 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 1.8 to 5.5 feet. 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

  10. Level II scour analysis for Bridge 86 (VERNVT01420086) on State Route 142, crossing Broad Brook, Vernon, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.

    1997-01-01

    roadway. A scour hole 2 ft deeper than the mean thalweg depth was observed along the left bank side of the pier during the Level I assessment. There was also a scour hole 1 ft deeper than the mean thalweg depth observed along the length of the right abutment. The only scour protection measure at the site was type-2 stone fill (less than 36 inches diameter) along the entire base length of the spill-through slopes. 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. There was no computed contraction scour for any modelled flows. Scour at the left abutment ranged from 13.2 to 15.9 ft and at the right abutment ranged from 12.0 to 16.3 ft. The worst-case abutment scour occurred at the 500-year discharge. Pier scour ranged from 12.0 to 16.3 ft. The worst-case pier scour occurred 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

  11. Level II scour analysis for Bridge 10 (WFIETH00170010) on Town Highway 17, crossing Taft Brook, Westfield, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1997-01-01

    2 stone fill (less than 36 inches diameter) at the ends of each wingwall. 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 0.1 to 0.4 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour at the left abutment ranged from 6.1 to 7.7 ft. Abutment scour at the right abutment ranged from 4.3 to 5.4 ft.The worst-case abutment scour occurred at the 500-year discharge for both abutments. 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

  12. Level II scour analysis for Bridge 27 (ANDOTH00290027) on Town Highway 29, crossing Middle Branch Williams River, Andover, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Wild, Emily C.

    1997-01-01

    2 stone fill (less than 36 inches diameter) along the upstream right bank and downstream left bank and around the upstream left and right wingwalls. Type- 3 stone fill (less than 48 inches diameter) is located along the base of the left abutment in the scour hole, at the end of the downstream left wingwall and along the upstream 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 0.4 to 0.9 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge and the 100-year discharge. Abutment scour ranged from 10.7 to 13.6 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

  13. Trojan Horse Transit Contributes to Blood-Brain Barrier Crossing of a Eukaryotic Pathogen.

    PubMed

    Santiago-Tirado, Felipe H; Onken, Michael D; Cooper, John A; Klein, Robyn S; Doering, Tamara L

    2017-01-31

    The blood-brain barrier (BBB) protects the central nervous system (CNS) by restricting the passage of molecules and microorganisms. Despite this barrier, however, the fungal pathogen Cryptococcus neoformans invades the brain, causing a meningoencephalitis that is estimated to kill over 600,000 people annually. Cryptococcal infection begins in the lung, and experimental evidence suggests that host phagocytes play a role in subsequent dissemination, although this role remains ill defined. Additionally, the disparate experimental approaches that have been used to probe various potential routes of BBB transit make it impossible to assess their relative contributions, confounding any integrated understanding of cryptococcal brain entry. Here we used an in vitro model BBB to show that a "Trojan horse" mechanism contributes significantly to fungal barrier crossing and that host factors regulate this process independently of free fungal transit. We also, for the first time, directly imaged C. neoformans-containing phagocytes crossing the BBB, showing that they do so via transendothelial pores. Finally, we found that Trojan horse crossing enables CNS entry of fungal mutants that cannot otherwise traverse the BBB, and we demonstrate additional intercellular interactions that may contribute to brain entry. Our work elucidates the mechanism of cryptococcal brain invasion and offers approaches to study other neuropathogens.

  14. The Spin Contribution to the pp-TOTAL Cross-Section at High Energy

    NASA Astrophysics Data System (ADS)

    Andreeva, E. A.; Strikhanov, M. N.; Nurushev, S. B.

    The experimental data on the pp-total cross-sections including the spin-dependent parts are analyzed with the goal to determine the contribution of spin interactions at high energies. Based on the Regge model with cuts, the energy dependencies of such contributions are estimated for two spin-dependent terms: (1) the total spin dependent term, σ1 and (2) the spin projection dependent term, σ2. The estimates show that their contributions to the unpolarized total cross section, σ0, decrease with energy from several % around 2 GeV/c to 10-2% around 200 GeV/c. The assumption σ1= -σ2 does not seem to be correct, while the hypothesis 3 σ1=-σ2 is more preferable, especially in the measured energy interval 2-6 GeV. There is a clear indication that the spin effects are sensitive to the pomeron intercept at - t=0 (GeV/c)2. In order to pin down such effects the spin dependent total cross-sections must be measured with precisions better than 10 μb at 200 GeV/c.

  15. Trojan Horse Transit Contributes to Blood-Brain Barrier Crossing of a Eukaryotic Pathogen

    PubMed Central

    Santiago-Tirado, Felipe H.; Onken, Michael D.; Cooper, John A.; Klein, Robyn S.

    2017-01-01

    ABSTRACT The blood-brain barrier (BBB) protects the central nervous system (CNS) by restricting the passage of molecules and microorganisms. Despite this barrier, however, the fungal pathogen Cryptococcus neoformans invades the brain, causing a meningoencephalitis that is estimated to kill over 600,000 people annually. Cryptococcal infection begins in the lung, and experimental evidence suggests that host phagocytes play a role in subsequent dissemination, although this role remains ill defined. Additionally, the disparate experimental approaches that have been used to probe various potential routes of BBB transit make it impossible to assess their relative contributions, confounding any integrated understanding of cryptococcal brain entry. Here we used an in vitro model BBB to show that a “Trojan horse” mechanism contributes significantly to fungal barrier crossing and that host factors regulate this process independently of free fungal transit. We also, for the first time, directly imaged C. neoformans-containing phagocytes crossing the BBB, showing that they do so via transendothelial pores. Finally, we found that Trojan horse crossing enables CNS entry of fungal mutants that cannot otherwise traverse the BBB, and we demonstrate additional intercellular interactions that may contribute to brain entry. Our work elucidates the mechanism of cryptococcal brain invasion and offers approaches to study other neuropathogens. PMID:28143979

  16. 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

  17. Level II scour analysis for Bridge 37 (BARTTH00080037) on Town Highway 8, crossing Willoughby River, Barton, Vermont

    USGS Publications Warehouse

    Ayotte, Joseph D.; Boehmler, Erick M.

    1996-01-01

    of north-central Vermont in the town of Barton. The 60.4-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the banks have sparse to moderate woody vegetation coverage. In the study area, the Willoughby River is probably incised, has a sinuous channel with a slope of approximately 0.009 ft/ft, an average channel top width of 108 ft and an average channel depth of 6 ft. The predominant channel bed material is cobble (D50 is 95.1 mm or 0.312 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 20, 1994, indicated that the reach was stable. The town highway 8 crossing of the Willoughby River is a 96-ft-long, two-lane bridge consisting of one 94-foot steel-beam span (Vermont Agency of Transportation, written communication, August 4, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15 degrees to the opening while the opening-skew-to-roadway is 10 degrees. No scour was reported in the channel or along abutments or wingwalls during the Level I assessment. Type-2 stone fill (less than 24 inches diameter) was reported at each abutment and all four wingwalls. 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. Data in appendix D (Vermont Agency of Transportation, written communication, August 4, 1994) indicate that the right abutment may be founded on or near marble bedrock which may limit scour depths. Bedrock was not detected by borings in the vicinity of the left abutment. The scour analysis results are presented in tables 1 and 2 and a graph of the scour depths is presented in figure

  18. 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.

  19. 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.

  20. 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.

  1. Level II scour analysis for Bridge 30 (MNTGTH00410030) on Town Highway 41, crossing the Trout River, Montgomery, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Medalie, Laura

    1997-01-01

    Contraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 2.5 to 8.9 ft. The worst-case abutment scour occurred at the 500-year discharge. The computed scour depths are well above the pile depths set in bedrock. 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.

  2. Level II scour analysis for Bridge 49 (FFIETH00290049) on Town Highway29, crossing Black Creek, Fairfield, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 4.4 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.5 to 14.3 ft and 12.2 to 16.3 ft on the left and right abutments respectively. 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.

  3. Level II scour analysis for Bridge 2 (STAMVT01000002) on State Route 100 crossing Roaring Brook, Stamford, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Hammond, Robert E.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.8 feet. The worst-case contraction scour occurred at the 100-year discharge. Abutment scour ranged from 4.2 to 9.3 feet. The worst-case abutment scour occurred at the 500-year 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. 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 13 (IRAVT013300133) on State Route 133, crossing an Ira Brook Tributary, Ira, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.

    1996-01-01

    There was no computed contraction scour for any of the modelled flows. Abutment scour ranged from 3.6 to 4.7 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). 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. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Level II scour analysis for Bridge 42 (BENNCYSCHL0042) on School Street, crossing Walloomsac River, Bennington, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Degnan, James R.

    1997-01-01

    Contraction scour computed for all modelled flows was 0.0 ft. Computed left abutment scour ranged from 9.4 to 10.2 ft. with the worst-case scour occurring at the 500-year discharge. Computed right abutment scour ranged from 2.7 to 5.7 ft. with the worst-case scour 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, 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 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.

  11. 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.

  12. Click-chemistry strategy for labeling antibodies with copper-64 via a cross-bridged tetraazamacrocyclic chelator scaffold.

    PubMed

    Kumar, Amit; Hao, Guiyang; Liu, Li; Ramezani, Saleh; Hsieh, Jer-Tsong; Öz, Orhan K; Sun, Xiankai

    2015-04-15

    We report a click-chemistry based modular strategy for antibody labeling with (64)Cu (t1/2 = 12.7 h; β(+) 0.656 MeV, 17.4%; β(-) 0.573 MeV, 39%; EC 43%) under ambient condition utilizing a cross-bridged tetraazamacrocyclic (CB-TE2A) analogue, which otherwise requires harsh conditions that make the CB-TE2A analogues under-utilized for protein labeling despite the fact that they form kinetically inert copper complexes with high in vivo stability. Our strategy involves prelabeling a CB-TE2A based scaffold (CB-TE2A-1C) with (64)Cu and its subsequent reaction with an antibody via the tetrazine-norbornene mediated click chemistry. The effectiveness of this strategy was demonstrated by labeling two monoclonal antibodies, an anti-PSMA antibody (YPSMA-1) and a chimeric anti-phosphatidylserine antibody (Bavituximab). The immunoreactivity of the antibodies remained unchanged after the tetrazine modification and click-chemistry (64)Cu labeling. To further demonstrate the practicality of the modular (64)Cu labeling strategy, we tested positron emission tomography (PET) imaging of tumor with the (64)Cu-labeled bavituximab in a mouse xenograft model. The tumor visualization and uptake of the labeled antibody exhibited the versatility of the click-chemistry strategy.

  13. Level II scour analysis for Bridge 12 (NEWFVT00300012) on State Route 30, crossing Smith Brook, Newfane, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Medalie, Laura

    1997-01-01

    Contraction scour for modelled flows ranged from 1.2 to 1.8 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.6 to 14.1 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 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 (CHESVT01030012) on State Highway 103, crossing the Williams River, Chester, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Burns, Ronda L.

    1997-01-01

    northerly pier) and from 13.5 to 17.1 ft along Pier 2 (southerly pier). 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.

  15. Level II scour analysis for Bridge 16 (TROYTH00290016) on Town Highway 29, crossing Beetle Brook, Troy, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 1.8 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 9.2 to 13.4 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.

  16. 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.

  17. Level II scour analysis for Bridge 23 (HARDTH00530023) on Town Highway 53, crossing Haynesville Brook, Hardwick, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 2.0 ft. The worst-case contraction scour occurred at the 100-year discharge. Abutment scour ranged from 7.0 to 12.9 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). 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

  18. Level II scour analysis for Bridge 1 (CANATH00010001) on Town Highway 1, crossing Halls Stream, Canaan, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.

    1996-01-01

    Contraction scour for all modelled flows ranged from 8.0 to 8.8 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 8.9 to 17.3 ft. The worst-case abutment scour occurred at the 500-year discharge. For the two piers, scour ranged from 11.1 to 15.8. The worst-case pier scour occurred for pier2 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.

  19. Level II scour analysis for Bridge 36 (RANDTH00480036) on Town Highway 48, crossing Snows Brook, Randolph, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.8 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.1 to 11.6 ft. The worst-case abutment scour occurred at the incipient-overtopping discharge, which was 50 cfs lower than 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 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.

  1. 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.

  2. 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.

  3. Level II scour analysis for Bridge 15 (TROYTH00290015) on Town Highway 29, crossing Beetle Brook, Troy, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Medalie, Laura

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.6 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge. Left abutment scour ranged from 8.0 to 8.9 ft. The worst-case left abutment scour occurred at the 500-year discharge. Right abutment scour ranged from 15.4 to 16.5 ft. The worst-case right abutment scour occurred at the incipient-overtopping 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.

  4. Level II scour analysis for Bridge 81 (NFIETH00PL0081) on Pleasant Street, crossing Union Brook, Northfield, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Medalie, Laura

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.5 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.2 to 13.3 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.

  5. Level II scour analysis for Bridge 17 (POMFTH00010017) on Town Highway 1 (FAS 166) crossing Mill Brook, Pomfret, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Hammond, Robert E.

    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 3.6 to 7.1 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 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 92 (WSTOVT01000092) on State Highway 100, crossing the West River, Weston, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Burns, Ronda L.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.4 to 2.1 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 8.4 to 30.7 ft. The worst-case abutment scour occurred at the 500-year discharge along 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. 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 7 (WARRTH00010007) onTown Highway 1, crossing Freemans Brook, Warren, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Burns, Ronda L.

    1997-01-01

    The computed contraction scour for all modelled flows was 0.0 feet. Abutment scour ranged from 5.3 to 8.2 ft. The worst-case abutment scour occurred at the right abutment for 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.

  8. Level II scour analysis for Bridge 45 (NFIETH00250045) on Town Highway 25, crossing Union Brook, Northfield, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Ivanoff, Michael A.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.4 to 0.9 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.5 to 9.1 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.

  9. 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.

  10. Level II scour analysis for Bridge 25 (CLARTH00100025) on Town Highway 10, crossing the Clarendon River, Clarendon, Vermont

    USGS Publications Warehouse

    Ayotte, Joseph D.

    1996-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.8 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 5.7 to 10.6 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 5 (CHELTH00030005) on Town Highway 3, crossing Jenkins Brook, Chelsea, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.

    1996-01-01

    Contraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 7.6 to 12.4 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.

  12. 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.

  13. 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.

  14. Level II scour analysis for Bridge 65 (NEWBTH00500065) on Town Highway 50, crossing Peach Brook, Newbury, Vermont

    USGS Publications Warehouse

    Burns, R.L.; Severance, Timothy

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 1.3 ft. The worst-case contraction scour occurred at the incipient roadway-overtopping discharge, which was less than the 100-year discharge. The right abutment scour ranged from 6.1 to 7.2 ft. The worstcase right abutment scour occurred at the incipient roadway-overtopping discharge. The left abutment scour ranged from 7.1 to 10.3 ft. The worst-case left 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 he

  15. Level II scour analysis for Bridge 23 (WALDTH00060023) on Town Highway 6, crossing Stannard Brook, Walden, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Hammond, Robert E.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure WALDTH00060023 on Town Highway 6 crossing Stannard Brook, Walden, 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 5.61-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the upstream surface cover is shrub and brushland with some trees. The downstream surface cover is forest. In the study area, Stannard Brook has an incised, straight channel with a slope of approximately 0.02 ft/ft, an average channel top width of 54 ft and an average bank height of 9 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 64.0 mm (0.210 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 8, 1995, indicated that the reach was stable. The Town Highway 6 crossing of Stannard Brook is a 59-ft-long (bottom width), two-lane pipe arch culvert consisting of one 22-foot corrugated plate pipe arch span (Vermont Agency of Transportation, written communication, March 28, 1995). The opening length of the structure parallel to the bridge face is 21.9 ft.The pipe arch is supported by vertical, concrete kneewalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is zero degrees. A scour hole 1.5 ft deeper than the mean

  16. 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.

  17. Level II scour analysis for Bridge 6 (BRISVT01160006) on State Highway 116, crossing Little Notch Brook, Bristol, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Burns, Ronda L.

    1997-01-01

    Contraction scour for all modelled flows ranged from 3.2 to 4.3 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.0 to 10.0 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.

  18. Level II scour analysis for Bridge 37 (CABOTH00410037) on Town Highway 41, crossing the Winooski River, Cabot, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Medalie, Laura

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 2.7 ft. The worst-case contraction scour occurred at the maximum free-surface flow (with road overflow) discharge, which was less than the 100-year discharge. Abutment scour ranged from 9.8 to 10.7 ft along the left abutment and from 16.2 to 19.9 ft along the right abutment. The worstcase 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 and Hire equations (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 50 (STARTH00250050) on Town Highway 25, crossing Lewis Creek, Starksboro, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Boehmler, Erick M.

    1997-01-01

    Contraction scour for all modelled flows ranged from 5.2 to 9.1 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 13.1 to 18.2 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, 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 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.

  1. 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.

  2. Level II scour analysis for Bridge 16, (NEWBTH00500016) on Town Highway 50, crossing Halls Brook, Newbury, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Degnan, James R.

    1997-01-01

    Contraction scour for all modelled flows ranged from 2.6 to 4.6 ft. The worst-case contraction scour occurred at the incipient roadway-overtopping discharge. The left abutment scour ranged from 11.6 to 12.1 ft. The worst-case left abutment scour occurred at the incipient road-overtopping discharge. The right abutment scour ranged from 13.6 to 17.9 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. 46). 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 23 (WEELTH00210023) on Town Highway 21, crossing Miller Run, Wheelock, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Boehmler, Erick M.

    1997-01-01

    Contraction scour for all modelled flows was computed to be zero ft. Abutment scour ranged from 9.1 to 10.8 ft along the right abutment and from 9.8 to 12.3 ft along 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. 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 21 (WALDTH00450021) on Town HIghway 45, crossing Joes Brook, Walden, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Medalie, Laura

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 1.5 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 12.4 to 24.4 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”. 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.

  5. Level II scour analysis for Bridge 25 (DANVTH00610025) on Town Highway 61, crossing Water Andric Brook, Danville, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Severance, Timothy

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.7 to 1.3 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 9.1 to 12.5 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, 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 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 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.

  7. 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 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 8 (ATHETH00090008) on Town Highway 9, crossing Bull Creek, Athens, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Burns, Ronda 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 incipient-overtopping discharge of 1730 cubic feet per second, which was less than the 100-year discharge. Abutment scour ranged from 7.6 to 11.4 feet. 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.

  9. Level II scour analysis for Bridge 27 (STJOTH00080027) on Town Highway 8, crossing the Sleepers River, St. Johnsbury, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.

    1997-01-01

    Contraction scour computed for all modelled flows was zero ft. Abutment scour ranged from 6.2 to 9.7 ft. The worst-case abutment scour occurred at the 100-year discharge at the right abutment and at the 500-year 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. 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 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). 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 30, (HUNTTH00220030), on Town Highway 22, crossing Brush Brook, Huntington, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.

    1997-01-01

    Contraction scour for all modelled flows was zero. Abutment scour ranged from 7.8 to 10.1 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.

  12. Level II scour analysis for Bridge 5 (MORRTH00060005) on Town Highway 6, crossing Bedell Brook, Morristown, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Degnan, James R.

    1997-01-01

    Contraction scour for all modelled flows ranged from 1.1 to 2.0 feet. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 3.9 to 8.6 feet. The worst-case abutment scour occurred 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.

  13. Level II scour analysis for Bridge 23 (CRAFTH00390023) on Town Highway 39, crossing the Black River, Craftsbury, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.

    1997-01-01

    Contraction scour for all modelled flows ranged from 20.1 to 25.2 and the worst-case contraction scour occurred at the 500-year discharge. Although this bridge has two piers, the flow through the spans between each abutment and pier is assumed to be negligible. Hence, abutment scour was computed assuming the forces contributing to scour actually occur on the main-span sides of each pier in this case. Abutment scour ranged from 8.8 to 10.6 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. 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. Cu(I)-assisted click chemistry strategy for conjugation of non-protected cross-bridged macrocyclic chelators to tumour-targeting peptides.

    PubMed

    Cai, Zhengxin; Li, Barbara T Y; Wong, Edward H; Weisman, Gary R; Anderson, Carolyn J

    2015-03-07

    Copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click chemistry has inherent challenges for copper-labeled radiopharmaceuticals. An azide-modified phosphonate-based cross-bridged macrocyclic chelator was synthesized for click chemistry conjugation with azide-modified Y3-TATE (a somatostatin analogue) on resin, without the need for protecting the chelator. The (64)Cu-labeled bioconjugate shows favourable in vitro and in vivo behaviour.

  15. 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

  16. Kinetic, Magnetic and Cross-helicity Contributions to the Turbulent Cascade in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Forman, M. A.; Stawarz, J. E.; Smith, C. W.

    2009-12-01

    In classic Kolmogorov theory of inertial-range turbulence, the third moment of velocity fluctuations at spatial lag L, is proportional to L times the rate of energy input at large scales (= epsilon = dissipation rate). Furthermore, the turbulent power is proportional to the 2/3 power of epsilon. In the MHD solar wind, energy and energy cascade involve both velocity and magnetic fluctuations, and the third moment related to energy dissipation has three terms: (1) the same hydrodynamic term, of correlations between velocity fluctuations and kinetic energy, (2) correlations between velocity fluctuations and magnetic energy, and (3) correlations between magnetic fluctuations and cross-helicity. We used ACE MAG/SWEPAM merged data set for the last decade, to separately determine these three third moments at lags from 64 seconds to 2 hours to see how each term varies with L, and contributes to the energy cascade, and how they add up. Moments were calculated for 12-hour intervals. Mean values and error bars were calculated for intervals in 12 types of solar wind sorted by their turbulent energy level and their bulk cross-helicity, or “imbalance”. With calculated accuracy, we report that when the cross-helicity is small, 1. Energy dissipation rate is proportional to turbulent power^3/2, as Kolmogorov theory predicts 2. The magnetic energy term is approximately equal to the kinetic energy (hydrodynamic) term; however 3. The cross-helicity term nearly cancels the magnetic energy term, so that the energy third moment is only slightly larger than the hydrodynamic term alone. When the cross-helicity is large, 1. All three Energy third moments are dramatically suppressed. 2. Energy dissipation rate deduced from third moment scaling is small or possibly negative, and does NOT agree with Kolmogorov, implying that 3. Most of the energy in fluctuating fields is NOT part of a direct inertial cascade.

  17. Electrophysiological low-frequency coherence and cross-frequency coupling contribute to BOLD connectivity.

    PubMed

    Wang, Liang; Saalmann, Yuri B; Pinsk, Mark A; Arcaro, Michael J; Kastner, Sabine

    2012-12-06

    Brain networks are commonly defined using correlations between blood oxygen level-dependent (BOLD) signals in different brain areas. Although evidence suggests that gamma-band (30-100 Hz) neural activity contributes to local BOLD signals, the neural basis of interareal BOLD correlations is unclear. We first defined a visual network in monkeys based on converging evidence from interareal BOLD correlations during a fixation task, task-free state, and anesthesia, and then simultaneously recorded local field potentials (LFPs) from the same four network areas in the task-free state. Low-frequency oscillations (<20 Hz), and not gamma activity, predominantly contributed to interareal BOLD correlations. The low-frequency oscillations also influenced local processing by modulating gamma activity within individual areas. We suggest that such cross-frequency coupling links local BOLD signals to BOLD correlations across distributed networks.

  18. Electrophysiological low-frequency coherence and cross-frequency coupling contributes to BOLD connectivity

    PubMed Central

    Wang, Liang; Saalmann, Yuri B.; Pinsk, Mark A.; Arcaro, Michael J.; Kastner, Sabine

    2012-01-01

    SUMMARY Brain networks are commonly defined using correlations between blood oxygen level-dependent (BOLD) signals in different brain areas. Although evidence suggests that gamma band (30–100 Hz) neural activity contributes to local BOLD signals, the neural basis of inter-areal BOLD correlations is unclear. We first defined a visual network in monkeys based on converging evidence from inter-areal BOLD correlations during a fixation task, task-free state and anesthesia, and then simultaneously recorded local field potentials (LFPs) from the same four network areas in the task-free state. Low frequency oscillations (< 20 Hz), and not gamma activity, predominantly contributed to inter-areal BOLD correlations. The low frequency oscillations also influenced local processing by modulating gamma activity within individual areas. We suggest that such cross-frequency coupling links local BOLD signals to BOLD correlations across distributed networks. PMID:23217748

  19. Synthesis, structural studies, and oxidation catalysis of the late-first-row-transition-metal complexes of a 2-pyridylmethyl pendant-armed ethylene cross-bridged cyclam.

    PubMed

    Jones, Donald G; Wilson, Kevin R; Cannon-Smith, Desiray J; Shircliff, Anthony D; Zhang, Zhan; Chen, Zhuqi; Prior, Timothy J; Yin, Guochuan; Hubin, Timothy J

    2015-03-02

    The first 2-pyridylmethyl pendant-armed ethylene cross-bridged cyclam ligand has been synthesized and successfully complexed to Mn(2+), Fe(2+), Co(2+), Ni(2+), Cu(2+), and Zn(2+) cations. X-ray crystal structures were obtained for all six complexes and demonstrate pentadentate binding of the ligand with the requisite cis-V configuration of the cross-bridged cyclam ring in all cases, leaving a potential labile binding site cis to the pyridine donor for interaction of the complex with oxidants and/or substrates. The electronic properties of the complexes were evaluated using solid-state magnetic moment determination and acetonitrile solution electronic spectroscopy, which both agree with the crystal structure determination of high-spin divalent metal complexes in all cases. Cyclic voltammetry in acetonitrile revealed reversible redox processes in all but the Ni(2+) complex, suggesting that catalytic reactivity involving electron-transfer processes is possible for complexes of this ligand. Kinetic studies of the dissociation of the ligand from the copper(II) complex under strongly acidic conditions and elevated temperatures revealed that the pyridine pendant arm actually destabilizes the complex compared to the parent cross-bridged cyclam complex. Screening for oxidation catalysis using hydrogen peroxide as the terminal oxidant for the most biologically relevant Mn(2+), Fe(2+), and Cu(2+) complexes identified the Mn(2+) complex as a potential mild oxidation catalyst worthy of continued development.

  20. From Cycling Between Coupled Reactions to the Cross-Bridge Cycle: Mechanical Power Output as an Integral Part of Energy Metabolism

    PubMed Central

    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

  1. 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

  2. Level II scour analysis for Bridge 57 (BRIDTH00650057) on Town Highway 65, crossing Broad Brook, Bridgewater, Vermont

    USGS Publications Warehouse

    Ayotte, Joseph D.; Olson, Scott 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 0.4 ft to 1.5 ft and the worst-case contraction scour occurred at the incipient overtopping discharge. Abutment scour ranged from 6.0 ft to 14.6 ft and the worst-case abutment scour occurred at the 100-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.

  3. Level II scour analysis for Bridge 34 (RANDTH00660034) on Town Highway 66, crossing Second Branch White River, Randolph, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Ayotte, Joseph D.

    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 6.3 ft to 7.8 ft and the worst-case contraction scour occurred at the 100-year discharge. Abutment scour ranged from 7.9 ft to 20.3 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.

  4. Level II scour analysis for Bridge 25 (HARDTH00420025) on Town Highway 42, crossing Lamoille River, Hardwick, Vermont

    USGS Publications Warehouse

    Ayotte, Joseph D.

    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 was 0.0 ft. Abutment scour ranged from 6.5 ft to 15.6 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.

  5. 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.

  6. Lewis-acid-promoted stoichiometric and catalytic oxidations by manganese complexes having cross-bridged cyclam ligand: a comprehensive study.

    PubMed

    Dong, Lei; Wang, Yujuan; Lv, Yanzong; Chen, Zhuqi; Mei, Fuming; Xiong, Hui; Yin, Guochuan

    2013-05-06

    Redox-inactive metal ions have been recognized to be able to participate in redox metal-ion-mediated biological and chemical oxidative events; however, their roles are still elusive. This work presents how the redox-inactive metal ions affect the oxidative reactivity of a well-investigated manganese(II) with its corresponding manganese(IV) complexes having cross-bridged cyclam ligand. In dry acetone, the presence of these metal ions can greatly accelerate stoichiometric oxidations of triphenylphosphine and sulfides by the manganese(IV) complexes through electron transfer or catalytic sulfoxidations by the corresponding manganese(II) complexes with PhIO. Significantly, the rate enhancements are highly Lewis-acid strength dependent on added metal ions. These metal ions like Al(3+) can also promote the thermodynamic driving force of the Mn(IV)-OH moiety to facilitate its hydrogen abstraction from ethylbenzene having a BDE(CH) value of 85 kcal/mol, while it is experimentally limited to 80 kcal/mol for Mn(IV)-OH alone. Adding Al(3+) may also improve the manganese(II)-catalyzed olefin epoxidation with PhIO. However, compared with those in electron transfer, improvements in hydrogen abstraction and electron transfer are minor. The existence of the interaction between Lewis acid and the manganese(IV) species was evidenced by the blue shift of the characteristic absorbance of the manganese(IV) species from 554 to 537 nm and by converting its EPR signal at g = 2.01 into a hyperfine 6-line signal upon adding Al(3+) (I = 5/2). Cyclic voltammograms of the manganese(IV) complexes reveal that adding Lewis acid would substantially shift its potential to the positive direction, thus enhancing its oxidizing capability.

  7. 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.

  8. Level II scour analysis for Bridge 25 (ANDOTH00230025) on Town Highway 23, crossing Andover Branch, Andover, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Burns, Ronda L.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ANDOTH00230025 on Town Highway 23 crossing the Andover Branch, 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 6.74-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 overbank and forest on the left overbank while the immediate banks, both upstream and downstream, are forested. In the study area, the Andover Branch has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 55 ft and an average bank height of 9 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 78.4 mm (0.257 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 27, 1996, indicated that the reach was stable. The Town Highway 23 crossing of the Andover Branch is a 25-ft-long, two-lane structure consisting of a multi-plate corrugated steel arch culvert with concrete footings (Vermont Agency of Transportation, written communication, March 29, 1995). The culvert is mitered at the inlet and outlet. The channel is skewed approximately zero degrees to the opening while the opening-skew-to-roadway is zero degrees. The footings are exposed approximately 1.25 ft, with the

  9. The effect of thin filament activation on the attachment of weak binding cross-bridges: A two-dimensional x-ray diffraction study on single muscle fibers.

    PubMed Central

    Kraft, T; Xu, S; Brenner, B; Yu, L C

    1999-01-01

    To study possible structural changes in weak cross-bridge attachment to actin upon activation of the thin filament, two-dimensional (2D) x-ray diffraction patterns of skinned fibers from rabbit psoas muscle were recorded at low and high calcium concentration in the presence of saturating concentrations of MgATPgammaS, a nucleotide analog for weak binding states. We also studied 2D x-ray diffraction patterns recorded under relaxing conditions at an ionic strength above and below 50 mM, because it had been proposed from solution studies that reducing ionic strength below 50 mM also induces activation of the thin filament. For this project a novel preparation had to be established that allows recording of 2D x-ray diffraction patterns from single muscle fibers instead of natural fiber bundles. This was required to minimize substrate depletion or product accumulation within the fibers. When the calcium concentration was raised, the diffraction patterns recorded with MgATPgammaS revealed small changes in meridional reflections and layer line intensities that could be attributed in part to the effects of calcium binding to the thin filament (increase in I380, decrease in first actin layer line intensity, increase in I59) and in part to small structural changes of weakly attached cross-bridges (e.g., increase in I143 and I72). Calcium-induced small-scale structural rearrangements of cross-bridges weakly attached to actin in the presence of MgATPgammaS are consistent with our previous observation of reduced rate constants for attachment and detachment of cross-bridges with MgATPgammaS at high calcium. Yet, no evidence was found that weakly attached cross-bridges change their mode of attachment toward a stereospecific conformation when the actin filament is activated by adding calcium. Similarly, reducing ionic strength to less than 50 mM does not induce a transition from nonstereospecific to stereospecific attachment. PMID:10049330

  10. Single Molecule Fluorescence Image Patterns Linked to Dipole Orientation and Axial Position: Application to Myosin Cross-Bridges in Muscle Fibers

    PubMed Central

    Burghardt, Thomas P.

    2011-01-01

    Background Photoactivatable fluorescent probes developed specifically for single molecule detection extend advantages of single molecule imaging to high probe density regions of cells and tissues. They perform in the native biomolecule environment and have been used to detect both probe position and orientation. Methods and Findings Fluorescence emission from a single photoactivated probe captured in an oil immersion, high numerical aperture objective, produces a spatial pattern on the detector that is a linear combination of 6 independent and distinct spatial basis patterns with weighting coefficients specifying emission dipole orientation. Basis patterns are tabulated for single photoactivated probes labeling myosin cross-bridges in a permeabilized muscle fiber undergoing total internal reflection illumination. Emitter proximity to the glass/aqueous interface at the coverslip implies the dipole near-field and dipole power normalization are significant affecters of the basis patterns. Other characteristics of the basis patterns are contributed by field polarization rotation with transmission through the microscope optics and refraction by the filter set. Pattern recognition utilized the generalized linear model, maximum likelihood fitting, for Poisson distributed uncertainties. This fitting method is more appropriate for treating low signal level photon counting data than χ2 minimization. Conclusions Results indicate that emission dipole orientation is measurable from the intensity image except for the ambiguity under dipole inversion. The advantage over an alternative method comparing two measured polarized emission intensities using an analyzing polarizer is that information in the intensity spatial distribution provides more constraints on fitted parameters and a single image provides all the information needed. Axial distance dependence in the emission pattern is also exploited to measure relative probe position near focus. Single molecule images from axial

  11. Conformation-determined through-bond versus through-space electronic communication in mixed-valence systems with a cross-conjugated urea bridge.

    PubMed

    Gong, Zhong-Liang; Zhong, Yu-Wu; Yao, Jiannian

    2015-01-19

    Bis-triarylamine 2 and cyclometalated diruthenium 6(PF6)2 with a linear trans,trans-urea bridge have been prepared, together with the bis-triarylamine 3 and cyclometalated diruthenium 8(PF6)2 with a folded cis,cis-N,N-dimethylurea bridge. The linear or folded conformations of these molecules are supported by single-crystal X-ray structures of 2, 3, and other related compounds. These compounds display two consecutive anodic redox waves (N(·+/0) or Ru(III/II) processes) with a potential separation of 110-170 mV. This suggests that an efficient electronic coupling is present between two redox termini through the cross-conjugated urea bridge. The degree of electronic coupling has been investigated by using spectroelectrochemical measurements. Distinct intervalence charge-transfer (IVCT) transitions have been observed for mixed-valent (MV) compounds with a linear conformation. The IVCT transitions can also be identified for the folded MV compounds, albeit with a much weaker intensity. DFT results support that the electronic communication occurs by a through-bond and through-space pathway for the linear and folded compounds, respectively. The IVCT transitions of the MV compounds have been reproduced by TDDFT calculations. For the purpose of comparison, a bistriarylamine and a diruthenium complex with an imidazolidin-2-one bridge and a urea-containing mono-triarylamine and monoruthenium complex have been synthesized and studied.

  12. Understanding the contribution of disulphide bridges to the folding and misfolding of an anti-Aβ scFv.

    PubMed

    Montoliu-Gaya, Laia; Martínez, Jose C; Villegas, Sandra

    2017-03-24

    ScFv-h3D6 is a single chain variable fragment that precludes Aβ peptide-induced cytotoxicity by withdrawing Aβ oligomers from the amyloid pathway to the worm-like pathway. Production of scFv molecules is not a straightforward procedure because of the occurrence of disulphide scrambled conformations generated in the refolding process. Here, we separately removed the disulphide bond of each domain and solved the scrambling problem; and then, we intended to compensate the loss of thermodynamic stability by adding three C-terminal elongation mutations previously described to stabilize the native fold of scFv-h3D6. Such stabilization occurred through stabilization of the intermediate state in the folding pathway and destabilization of a different, β-rich, intermediate state driving to worm-like fibrils. Elimination of the disulphide bridge of the less stable domain, VL , deeply compromised the yield and increased the aggregation tendency, but elimination of the disulphide bridge of the more stable domain, VH , solved the scrambling problem and doubled the production yield. Notably, it also changed the aggregation pathway from the protective worm-like morphology to an amyloid one. This was so because a partially unfolded intermediate driving to amyloid aggregation was present, instead of the β-rich intermediate driving to worm-like fibrils. When combining with the elongation mutants, stabilization of the partially unfolded intermediate driving to amyloid fibrils was the only effect observed. Therefore, the same mutations drove to completely different scenarios depending on the presence of disulphide bridges and this illustrates the relevance of such linkages in the stability of different intermediate states for folding and misfolding. This article is protected by copyright. All rights reserved.

  13. 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.

  14. Energy system contributions and determinants of performance in sprint cross-country skiing.

    PubMed

    Andersson, E; Björklund, G; Holmberg, H-C; Ørtenblad, N

    2017-04-01

    To improve current understanding of energy contributions and determinants of sprint-skiing performance, 11 well-trained male cross-country skiers were tested in the laboratory for VO2max , submaximal gross efficiency (GE), maximal roller skiing velocity, and sprint time-trial (STT) performance. The STT was repeated four times on a 1300-m simulated sprint course including three flat (1°) double poling (DP) sections interspersed with two uphill (7°) diagonal stride (DS) sections. Treadmill velocity and VO2 were monitored continuously during the four STTs and data were averaged. Supramaximal GE during the STT was predicted from the submaximal relationships for GE against velocity and incline, allowing computation of metabolic rate and O2 deficit. The skiers completed the STT in 232 ± 10 s (distributed as 55 ± 3% DP and 45 ± 3% DS) with a mean power output of 324 ± 26 W. The anaerobic energy contribution was 18 ± 5%, with an accumulated O2 deficit of 45 ± 13 mL/kg. Block-wise multiple regression revealed that VO2 , O2 deficit, and GE explained 30%, 15%, and 53% of the variance in STT time, respectively (all P < 0.05). This novel GE-based method of estimating the O2 deficit in simulated sprint-skiing has demonstrated an anaerobic energy contribution of 18%, with GE being the strongest predictor of performance.

  15. 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 Clark County, Indiana. Both Bridges are located in Jefferson County, Kentucky and Clark County, Indiana... shorter time period still applies. FOR FURTHER INFORMATION CONTACT: For FHWA: Mr. Duane Thomas,...

  16. 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…

  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. The antigens contributing to the serological cross-reactions of Proteus antisera with Klebsiella representatives.

    PubMed

    Palusiak, Agata

    2015-03-01

    Proteus sp. and Klebsiella sp. mainly cause infections of the urinary and respiratory tracts or wounds in humans. The representatives of both genera produce virulence factors like lipopolysaccharide (LPS) or outer membrane proteins (OMPs) having much in common in the structures and/or functions. To check how far this similarity is revealed in the serological cross-reactivity, the bacterial masses of 24 tested Klebsiella sp. strains were tested in ELISA with polyclonal rabbit antisera specific to the representatives of 79 Proteus O serogroups. The strongest reacting systems were selected to Western blot, where the majority of Klebsiella masses reacted in a way characteristic for electrophoretic patterns of proteins. The strongest reactions were obtained for proteins of near 67 and 40 kDa and 12.5 kDa. Mass spectrometry analysis of the proteins samples of one Proteus sp. and one Klebsiella sp. strain showed the GroEL like protein of a sequence GI number 2980926 to be similar for both strains. In Western blot some Klebsiella sp. masses reacted similarly to the homologous Proteus LPSs. The LPS contribution in the observed reactions of the high molecular-mass LPS species was confirmed for Klebsiella oxytoca 0.062.

  19. Contribution of rpoB Mutations to Development of Rifamycin Cross-Resistance in Mycobacterium tuberculosis

    PubMed Central

    Williams, D. L.; Spring, L.; Collins, L.; Miller, L. P.; Heifets, L. B.; Gangadharam, P. R. J.; Gillis, T. P.

    1998-01-01

    The contributions of 23 insertion, deletion, or missense mutations within an 81-bp fragment of rpoB, the gene encoding the β-subunit of the DNA-dependent RNA polymerase of Mycobacterium tuberculosis, to the development of resistance to rifamycins (rifampin, rifabutin, rifapentine, and KRM-1648) in 29 rifampin-resistant clinical isolates were defined. Specific mutant rpoB alleles led to the development of cross-resistance to all rifamycins tested, while a subset of mutations were associated with resistance to rifampin and rifapentine but not to KRM-1648 or rifabutin. To further study the impact of specific rpoB mutant alleles on the development of rifamycin resistance, mutations were incorporated into the rpoB gene of M. tuberculosis H37Rv, contained on a mycobacterial shuttle plasmid, by in vitro mutagenesis. Recombinant M. tuberculosis clones containing plasmids with specific mutations in either codon 531 or 526 of rpoB exhibited high-level resistance to all rifamycins tested, whereas clones containing a plasmid with a mutation in codon 516 exhibited high-level resistance to rifampin and rifapentine but were susceptible to both rifabutin and KRM-1648. These results provided additional proof of the association of specific rpoB mutations with the development of rifamycin resistance and corroborate previous reports of the usefulness of rpoB genotyping for predicting rifamycin-resistant phenotypes. PMID:9661035

  20. 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

  1. 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.

  2. 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.

  3. Level II scour analysis for Bridge 34 (CORITH0050034) on Town Highway 50, crossing the South Branch Waits River, Corinth, 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 CORITH00500034 on Town Highway 50 crossing the South Branch Waits River, Corinth, 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 35.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream and downstream of the bridge while the immediate banks have dense woody vegetation. In the study area, the South Branch Waits River has an incised, meandering channel with a slope of approximately 0.005 ft/ft, an average channel top width of 63 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 23.7 mm (0.078 ft). The geomorphic assessment at the time of the Level I and Level II site visit on September 5, 1995, indicated that the reach was stable. The Town Highway 50 crossing of the South Branch Waits River is a 56-ft-long, one-lane bridge consisting of one 54-foot steel thru-truss span (Vermont Agency of Transportation, written communication, March 24, 1995). The opening length of the structure parallel to the bridge face is 51.5 ft.The bridge is supported by vertical, concrete abutments with no wingwalls. Stone fill and bank material in front of the abutments create spill-through embankments. The channel is skewed

  4. Level II scour analysis for Bridge 35, (ANDOVT00110035) on State Route 11, crossing the Middle Branch Williams River, Andover, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ANDOVT00110035 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 (Federal Highway Administration, 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 4.65-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest on the left bank and small trees and brush on the right bank upstream and downstream of the bridge. In the study area, the Middle Branch Williams River has an incised, meandering channel with a slope of approximately 0.02 ft/ft, an average channel top width of 57 ft and an average bank height of 4 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 31.4 mm (0.103 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 28, 1996, indicated that the reach was laterally unstable. There are cut-banks upstream and downstream of the bridge and an island in the channel upstream. The State Route 11 crossing of the Middle Branch Williams River is a 28-ft-long, two-lane bridge consisting of one 24-ft concrete tee-beam span (Vermont Agency of Transportation, written communication, March 28, 1995). The opening length of the structure parallel to the bridge face is 23.6 ft. The bridge is supported by vertical, concrete abutments with

  5. 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

  6. Characterization of mutant xylanases using fourier transform ion cyclotron resonance mass spectrometry: stabilizing contributions of disulfide bridges and N-terminal extensions.

    PubMed

    Jänis, Janne; Turunen, Ossi; Leisola, Matti; Derrick, Peter J; Rouvinen, Juha; Vainiotalo, Pirjo

    2004-07-27

    Structural properties and thermal stability of Trichoderma reesei endo-1,4-beta-xylanase II (TRX II) and its three recombinant mutants were characterized using electrospray ionization Fourier transform ion cyclotron resonance (ESI FT-ICR) mass spectrometry and hydrogen/deuterium (H/D) exchange reactions. TRX II has been previously stabilized by a disulfide bridge C110-C154 and other site-directed mutations (TRX II mutants DS2 and DS5). Very recently, a highly thermostable mutant was introduced by combining mutations of DS5 with an N-terminal disulfide bridge C2-C28 (mutant DB1). Accurate mass measurements of TRX II, DS2, DS5, and DB1 verified the expected DNA-encoded protein sequences (average mass error 1.3 ppm) and allowed unequivocal assignment of the disulfides without chemical reduction and subsequent alkylation of the expected cross-links. Moreover, H/D exchange reactions provided means for the detection of a major heat-induced conformational change comprising two interconverting conformers of very different H/D exchange rates as well as allowed the apparent melting temperatures (T(m)) to be determined (62.6, 65.1, 68.0, and 82.2 degrees C for TRX II, DS2, DS5, and DB1, respectively). Residual activity measurements verified that the enzymes inactivated at significantly lower temperatures than expected on the basis of the apparent T(m) values, strongly suggesting that the inactivation takes place through minor conformational change other than observed by H/D exchange. ESI FT-ICR analyses also revealed molecular heterogeneity in DS5 and DB1 due to the propeptide incorporation. Resulting unintentional N-terminal extensions were observed to further improve the stability of the DB1 mutant. The extension of six amino acid residues upstream from the protein N-terminus increased stability by approximately 5 degrees C.

  7. 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.

  8. 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.

  9. A three-dimensional numerical model of a micro laminar flow fuel cell with a bridge-shaped microchannel cross-section

    NASA Astrophysics Data System (ADS)

    Lopez-Montesinos, Pedro O.; Desai, Amit V.; Kenis, Paul J. A.

    2014-12-01

    The operation of a laminar flow fuel cell (LFFC) involves complex interplay between various mass and electrochemical transport processes. Hence, to better design and more accurately predict performance, we developed a fully-coupled 3D numerical model that includes all the transport processes and electrochemical phenomena. Specifically, the model is based on the equations for the mass, momentum, species, and charge balances along with Butler-Volmer equations for electrode kinetics. The developed model was in excellent agreement with experimental data on a micro laminar flow fuel cell (μLFFC) with a bridge-shaped microchannel cross-section. Then, we used the model for a parametric study evaluating the influence of different operational and geometrical parameters (bridge aspect ratio, reactant flow rates, oxidant concentration) on the fuel cell performance (peak power density, fuel crossover, crossover current, power losses). The observed correlations were explained on the basis of mass and electrochemical transport phenomena, e.g., the behavior of the depletion zones at the fuel-oxidant and reactant-electrode interfaces. Based on these results, we recommend further design considerations for LFFCs. Although, the model was specifically developed for a particular μLFFC configuration, the computational model can be used to design and predict behavior of a wide variety of LFFC configurations.

  10. 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

  11. Level II scour analysis for Bridge 32 (FERRTH00190032) on Town Highway 19, crossing the South Slang Little Otter Creek, Ferrisburgh, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure FERRTH00190032 on Town Highway 19 crossing the South Slang Little Otter Creek (Hawkins Slang Brook), Ferrisburg, 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. The site is in the Champlain section of the St. Lawrence Valley physiographic province in west-central Vermont. The 8.00-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover consists of wetlands upstream and downstream of the bridge with trees and pasture on the wide flood plains. In the study area, the South Slang Little Otter Creek has a meandering channel with essentially no channel slope, an average channel top width of 932 ft and an average bank height of 6 ft. The channel bed material ranges from clay to sand. Sieve analysis indicates that greater than 50% of the sample is coarse silt and clay and thus a medium grain size by use of sieve analysis was indeterminate. The median grain size was assumed to be a course silt with a size (D50) of 0.061mm (0.0002 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 19 crossing of the South Slang Little Otter Creek is a 45-ft-long, twolane bridge consisting of one 42-foot concrete box-beam span (Vermont Agency of Transportation, written communication, December 11, 1995). The opening length of the structure parallel to the bridge face

  12. Level II scour analysis for Bridge 30 (NEWHTH00050030) on Town Highway 5, crossing the New Haven River, New Haven, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure NEWHTH00050030 on Town Highway 5 crossing the New Haven River, New Haven, 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 (Federal Highway Administration, 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 Champlain section of the St. Lawrence Valley physiographic province in west-central Vermont. The 115-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 downstream of the bridge while the immediate banks have dense woody vegetation. The upstream left bank is also pasture. The downstream left bank is forested.In the study area, the New Haven River has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 127 ft and an average bank height of 5 ft. The channel bed material ranges from silt to cobble with a median grain size (D50) of 20.4 mm (0.067 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 19, 1996, indicated that the reach was laterally unstable. The stream bends through the bridge and impacts the left bank where there is a cut bank and scour hole.The Town Highway 5 crossing of the New Haven River is a 181-ft-long, two-lane bridge consisting of four 45-ft concrete tee-beam spans (Vermont Agency of Transportation, written communication, December 15, 1995). The opening length of the structure parallel to the bridge face is 175.9 ft. The

  13. Level II scour analysis for Bridge 23 (WOLCTH00130023) on Town Highway 13, crossing the Wild Branch of the Lamoille River, Wolcott, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Degnan, James R.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure WOLCTH00130023 on Town Highway 13 crossing the Wild Branch Lamoille River, Wolcott, 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, collected 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 northcentral Vermont. The 27.7-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 upstream right overbank. The upstream left overbank is brushland. Downstream of the bridge, the surface cover is forested on the right overbank. The downstream left overbank is pasture while the immediate bank has dense woody vegetation. In the study area, the Wild Branch Lamoille River has an incised, straight channel with a slope of approximately 0.009 ft/ft, an average channel top width of 65 ft and an average bank height of 7 ft. The channel bed material ranges from sand to boulders with a median grain size (D50) of 85.3 mm (0.280 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 17, 1996 indicated that the reach was laterally unstable. The Town Highway 13 crossing of the Wild Branch Lamoille River is a 41-ft-long, one-lane bridge consisting of a 39-foot steel girder span (Vermont Agency of Transportation, written communication, October 13, 1995). The opening length of the structure parallel to the bridge face is 38 ft. The bridge is supported by

  14. Level II scour analysis for Bridge 5 (WOLCTH00150005) on Town Highway 15, crossing the Wild Branch Lamoille River, Wolcott, Vermont

    USGS Publications Warehouse

    Wild, Emily C.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure WOLCTH00150005 on Town Highway 15 crossing the Wild Branch Lamoille River, Wolcott, 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.During the August 1995 and July 1997 flood events, the left roadway was overtopped. Although there was loss of stone fill along the right abutment, the structure withstood both events.The site is in the Green Mountain section of the New England physiographic province in north- central Vermont. The 38.3-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream and downstream of the bridge, while the immediate banks have dense woody vegetation.In the study area, the Wild Branch Lamoille River has an incised, sinuous channel with a slope of approximately 0.006 ft/ft, an average channel top width of 98 ft and an average bank height of 5 ft. The channel bed material ranges from gravel to bedrock with a median grain size (D50) of 89.1 mm (0.292 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 17, 1996, indicated that the reach was stable.The Town Highway 15 crossing of the Wild Branch Lamoille River is a 46-ft-long, two-lane bridge consisting of a 43-foot prestressed concrete box-beam span (Vermont Agency of Transportation, written communication, October 13, 1995). The opening length of the structure parallel to the bridge face

  15. Level II scour analysis for Bridge 28 (STRATH00020028) on Town Highway 2, crossing the West Branch Ompompanoosuc River, Strafford, Vermont

    USGS Publications Warehouse

    Wild, Emily C.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure STRATH00020028 on Town Highway 2 crossing the West Branch Ompompanoosuc River, Strafford, 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, gathered 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 25.4-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream and downstream of the bridge. In the study area, the West Branch Ompompanoosuc River has a sinuous channel with a slope of approximately 0.002 ft/ft, an average channel top width of 34 ft and an average bank height of 6 ft. The channel bed material ranges from silt and clay to cobbles with a median grain size (D50) of 20.4 mm (0.0669 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 24, 1996, indicated that the reach was laterally unstable, because of moderate fluvial erosion. The Town Highway 2 crossing of the West Branch Ompompanoosuc River is a 31-ft-long, twolane bridge consisting of a 26-foot concrete tee-beam span (Vermont Agency of Transportation, written communication, October 23, 1995). The opening length of the structure parallel to the bridge face is 24.6 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 45 degrees to the opening while the computed opening-skew-toroadway is 5 degrees. A scour hole 3

  16. 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…

  17. The relative contribution of calcium, zinc and oxidation-based cross-links to the stiffness of Arion subfuscus glue.

    PubMed

    Braun, M; Menges, M; Opoku, F; Smith, A M

    2013-04-15

    Metal ions are present in many different biological materials, and are capable of forming strong cross-links in aqueous environments. The relative contribution of different metal-based cross-links was measured in the defensive glue produced by the terrestrial slug Arion subfuscus. This glue contains calcium, magnesium, zinc, manganese, iron and copper. These metals are essential to the integrity of the glue and to gel stiffening. Removal of all metals caused at least a 15-fold decrease in the storage modulus of the glue. Selectively disrupting cross-links involving hard Lewis acids such as calcium reduced the stiffness of the glue, while disrupting cross-links involving borderline Lewis acids such as zinc did not. Calcium is the most common cation bound to the glue (40 mmol l(-1)), and its charge is balanced primarily by sulphate at 82-84 mmol l(-1). Thus these ions probably play a primary role in bringing polymers together directly. Imine bonds formed as a result of protein oxidation also contribute substantially to the stiffness of the glue. Disrupting these bonds with hydroxylamine caused a 33% decrease in storage modulus of the glue, while stabilizing them by reduction with sodium borohydride increased the storage modulus by 40%. Thus a combination of metal-based bonds operates in this glue. Most likely, cross-links directly involving calcium play a primary role in bringing together and stabilizing the polymer network, followed by imine bond formation and possible iron coordination.

  18. View of the Warrington Avenue Bridge portal, inbound from Pittsburgh ...

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

    View of the Warrington Avenue Bridge portal, inbound from Pittsburgh - Pittsburgh & Castle Shannon Railroad, Warrington Avenue Bridge, Overbrook Trolley Line, Crossing Warrington Avenue, Pittsburgh, Allegheny County, PA

  19. Elevation of Warrington Avenue Bridge, southbound of Warrington Avenue ...

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

    Elevation of Warrington Avenue Bridge, southbound of Warrington Avenue - Pittsburgh & Castle Shannon Railroad, Warrington Avenue Bridge, Overbrook Trolley Line, Crossing Warrington Avenue, Pittsburgh, Allegheny County, PA

  20. View of the Warrington Avenue Bridge portal, outbound from Pittsburgh ...

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

    View of the Warrington Avenue Bridge portal, outbound from Pittsburgh - Pittsburgh & Castle Shannon Railroad, Warrington Avenue Bridge, Overbrook Trolley Line, Crossing Warrington Avenue, Pittsburgh, Allegheny County, PA

  1. 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.

  2. Bacteriocin protein BacL1 of Enterococcus faecalis targets cell division loci and specifically recognizes L-Ala2-cross-bridged peptidoglycan.

    PubMed

    Kurushima, Jun; Nakane, Daisuke; Nishizaka, Takayuki; Tomita, Haruyoshi

    2015-01-01

    Bacteriocin 41 (Bac41) is produced from clinical isolates of Enterococcus faecalis and consists of two extracellular proteins, BacL1 and BacA. We previously reported that BacL1 protein (595 amino acids, 64.5 kDa) is a bacteriolytic peptidoglycan D-isoglutamyl-L-lysine endopeptidase that induces cell lysis of E. faecalis when an accessory factor, BacA, is copresent. However, the target of BacL1 remains unknown. In this study, we investigated the targeting specificity of BacL1. Fluorescence microscopy analysis using fluorescent dye-conjugated recombinant protein demonstrated that BacL1 specifically localized at the cell division-associated site, including the equatorial ring, division septum, and nascent cell wall, on the cell surface of target E. faecalis cells. This specific targeting was dependent on the triple repeat of the SH3 domain located in the region from amino acid 329 to 590 of BacL1. Repression of cell growth due to the stationary state of the growth phase or to treatment with bacteriostatic antibiotics rescued bacteria from the bacteriolytic activity of BacL1 and BacA. The static growth state also abolished the binding and targeting of BacL1 to the cell division-associated site. Furthermore, the targeting of BacL1 was detectable among Gram-positive bacteria with an L-Ala-L-Ala-cross-bridging peptidoglycan, including E. faecalis, Streptococcus pyogenes, or Streptococcus pneumoniae, but not among bacteria with alternate peptidoglycan structures, such as Enterococcus faecium, Enterococcus hirae, Staphylococcus aureus, or Listeria monocytogenes. These data suggest that BacL1 specifically targets the L-Ala-L-Ala-cross-bridged peptidoglycan and potentially lyses the E. faecalis cells during cell division.

  3. Chitosan-cross-linked nanofibrous PHBV nerve guide for rat sciatic nerve regeneration across a defect bridge.

    PubMed

    Biazar, Esmaeil; Keshel, Saeed Heidari

    2013-01-01

    The aim of this study was to produce a chitosan-cross-linked nanofibrous biodegradable poly (3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit. The artificial nerve scaffold designed by electrospinning method and cross-linked with chitosan by chemical method. Afterwards, the scaffolds were evaluated by microscopic, physical, and mechanical analyses and cell culture assays with Schwann cells. The conduits were implanted into a 10 mm gap in the sciatic nerves of the rats. Four months after surgery, the regenerated nerves were evaluated by macroscopic assessments and histology. This polymeric conduit had sufficiently good mechanical properties to serve as a nerve guide. Cellular experiments showed a better cell adhesion, growth, and proliferation inside the cross-linked nanofibrous scaffolds compared with un-cross-linked ones, also Schwann cells well attached on chitosan-cross-linked nanofibrous surface. The in vivo results demonstrated that in the nanofibrous graft, the sciatic nerve trunk had been reconstructed with restoration of nerve continuity and formatted nerve fibers with myelination. This neural conduit appears to have the right organization for testing in vivo nerve tissue engineering studies.

  4. Level II scour analysis for Bridge 10 (BENNUS00070010) on U.S. Route 7, crossing the Walloomsac River, Bennington, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Burns, Ronda L.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BENNUS00070010 on U.S. Route 7, also known as North Street, crossing of the Walloomsac River, Bennington, 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 southwestern Vermont. The 30.1-mi2 drainage area is a predominantly rural and forested basin. The bridge site is located within an urban setting in the Town of Bennington with buildings, parking lots, lawns, and a playground on the overbank areas. In the study area, the Walloomsac River has a straight channel with constructed channel banks through much of the reach. The channel is located on a delta and has a slope of approximately 0.02 ft/ft, an average channel top width of 37 ft and an average bank height of 5 ft. The predominant channel bed material is cobble with a median grain size (D50) of 96.0 mm (0.315 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 5, 1996, indicated that the constructed reach was stable. The U.S. Route 7 crossing of the Walloomsac River is a 53-ft-long, two-lane bridge consisting of one 50-foot steel span (Vermont Agency of Transportation, written communication, September 27, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The wingwalls are angled in toward the channel because the widths of the upstream and downstream constructed

  5. Level II scour analysis for Bridge 3 (EASTTH00010003) on Town Highway 1, crossing the East Branch Passumpsic River, East Haven, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Boehmler, Erick M.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure EASTTH00010003 on Town Highway 1 crossing the East Branch Passumpsic River, East Haven, 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 50.4-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 is forest. On the remaining three banks the surface cover is pasture while the immediate banks have dense woody vegetation. In the study area, the East Branch Passumpsic River has an incised, sinuous channel with a slope of approximately 0.003 ft/ft, an average channel top width of 62 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 61.5 mm (0.187 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 14, 1995, indicated that the reach was stable. The Town Highway 1 crossing of the East Branch Passumpsic River is a 89-ft-long, two-lane bridge consisting of one 87-foot steel-beam span (Vermont Agency of Transportation, written communication, March 17, 1995). The opening length of the structure parallel to the bridge face is 84.7 ft. The bridge is supported by vertical, concrete abutments with sloped stone fill in front that creates a spill through embankment. The

  6. Level II scour analysis for Bridge 17 (RIPTTH00180017) on Town Highway 18, crossing the South Branch Middlebury River, Ripton, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Medalie, Laura

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure RIPTTH00180017 on Town Highway 18 crossing the South Branch Middlebury River, Ripton, 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 west-central Vermont. The 15.5-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 upstream left bank where it is shrubs and brush. In the study area, the South Branch Middlebury River has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 86 ft and an average bank height of 10 ft. The channel bed material ranges from gravel to boulders with a median grain size (D50) of 111 mm (0.364 ft). In addition, there is a bedrock outcrop across the channel downstream of the bridge. The geomorphic assessment at the time of the Level I and Level II site visit on June 10, 1996, indicated that the reach was stable. The Town Highway 18 crossing of the South Branch Middlebury River is a 61-ft-long, one-lane bridge consisting of one 58-foot steel-beam span (Vermont Agency of Transportation, written communication, November 30, 1995). The opening length of the structure parallel to the bridge face is 56.8 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 40 degrees to the

  7. Level II scour analysis for Bridge 52 (CHESTH00100052) on Town Highway 10, crossing the South branch Williams River, Chester, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Ivanoff, Michael A.

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure CHESTH00100052 on Town Highway 10 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 (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. The site is in the New England Upland section of the New England physiographic province in southeastern Vermont. The 4.05-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream and downstream of the bridge. 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 35 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 82.1 mm (0.269 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 21, 1996, indicated that the reach was unstable, as a result of the moderate bank erosion. The Town Highway 10 crossing of the South Branch Williams River is a 32-ft-long, one-lane bridge consisting of a 29-foot steel-stringer span (Vermont Agency of Transportation, written communication, March 31, 1995). The opening length of the structure parallel to the bridge face is 27.6 ft. 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 20 degrees. A scour hole 1.0 ft deeper than the

  8. Level II scour analysis for Bridge 63 (MTH0TH00120063) on Town Highway 12, crossing Russell Brook, Mount Holly, Vermont

    USGS Publications Warehouse

    Wild, Emily C.; Severance, Timothy

    1998-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure MTHOTH00120063 on Town Highway 12 crossing Russell Brook, Mount Holly, 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. The site is in the Green Mountain section of the New England physiographic province in south-central Vermont. The 3.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream and downstream of the bridge. In the study area, Russell Brook has an incised, sinuous channel with a slope of approximately 0.0263 ft/ft, an average channel top width of 29 ft and an average bank height of 3 ft. The channel bed material ranges from cobbles to boulders with a median grain size (D50) of 97.1 mm (0.318 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 4, 1995, indicated that the reach was stable. The Town Highway 12 crossing of Russell Brook is a 29-ft-long, one-lane bridge consisting of a 26-foot steel-stringer span (Vermont Agency of Transportation, written communication, March 21, 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 is skewed approximately 40 degrees to the opening while the computed opening-skew-to-roadway is 35 degrees. During the Level I assessment, it was observed that the upstream left wingwall footing was exposed 0.2 ft, in reference to

  9. Level II scour analysis for Bridge 29 (ROYATH00920029) on Town Highway 92, crossing the First Branch White River, Royalton, 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 ROYATH00920029 on Town Highway 92 crossing the First Branch White River, 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 101-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream and downstream of the bridge. In the study area, the First Branch White River has an incised, sinuous channel with a slope of approximately 0.001 ft/ft, an average channel top width of 81 ft and an average bank height of 9 ft. The channel bed material ranges from sand to bedrock with a median grain size (D50) of 1.18 mm (0.00347 ft). The geomorphic assessment at the time of the Level I site visit on July 23, 1996 and Level II site visit on June 2, 1995, indicated that the reach was stable. The Town Highway 92 crossing of the First Branch White River is a 59-ft-long, one-lane bridge consisting of a 57-foot steel-stringer span (Vermont Agency of Transportation, written communication, March 23, 1995). The opening length of the structure parallel to the bridge face is 52.2 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 zero degrees. A scour hole 4.0 ft deeper than the

  10. Level II scour analysis for Bridge 33 (TUNBTH00450033) on Town Highway 45, crossing the First Branch White River, Tunbridge, Vermont

    USGS Publications Warehouse

    Wild, E.C.; Severance, Timothy

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure TUNBTH00450033 on Town Highway 45 crossing the First Branch White River, Tunbridge, 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 86.4-mi 2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream and downstream of the bridge, while woody vegetation sparsely covers the immediate banks. In the study area, the First Branch White River has an incised, sinuous channel with a slope of approximately 0.003 ft/ft, an average channel top width of 68 ft and an average bank height of 7 ft. The channel bed material ranges from sand to gravel with a median grain size (D50) of 27.1 mm (0.089 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 18, 1995, indicated that the reach was laterally unstable due to a cut-bank present on the upstream right bank and a wide channel bar in the upstream reach. The Town Highway 45 crossing of the First Branch White River is a 67-ft-long, one-lane bridge consisting of one 54-foot timber thru-truss span (Vermont Agency of Transportation, written communication, March 23, 1995). The opening length of the structure parallel to the bridge face is 53.5 ft. The bridge is supported on the right by a vertical, concrete abutment

  11. 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…

  12. A Procedure to Quantify Contributions to the Total Cross Section by Mechanisms Competing to the Direct Ionization

    NASA Astrophysics Data System (ADS)

    Kröger, C. M. Romo

    2009-03-01

    Experimental quantitative analysis by PIXE (particle induced X-ray emission) is highly dependent on the composition of the substrate. It is known that highly ionized projectiles change the effective ionization in a collision with a specific atom. Particularly, 2P vacancies on the projectile ion can be produced within the sample and these vacancies will eventually be shared with the target atoms in the substrate, modifying the X-ray yield of the target. Therefore, it is of uttermost importance to account for these second order effects in the X-ray cross section to obtain an accurate result for a PIXE analysis. In this paper, it is proposed a new procedure to estimate quantitatively the contribution to the total ionization cross section of each effect: the direct and enhancement ionizations. Following Verma et al. (Nucl. Instr. and Meth. B245 56-60, 2006), it is modeled the total ionization cross section in a substrate by an exponentially decaying term that represents the enhancement ionization contribution, and a linearly growing term that represents the induced ionization contribution. Estimation of the parameters in the model can be obtained directly from irradiation of targets with different thickness.

  13. Level II scour analysis for Bridge 29 (PUTNTH00210029) on Town Highway 21, crossing East Putney Brook, Putney, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Ivanoff, Michael A.

    1997-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.9 feet. The worst-case contraction scour occurred at the incipient-overtopping discharge, which was less than the 100-year discharge. Abutment scour ranged from 6.1 to 18.4 feet. The worst-case abutment scour occurred at the 500-year discharge for the right abutment and the incipient overtopping discharge for 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 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.

  14. 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.

  15. 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.

  16. Level II scour analysis for Bridge 37 (TOWNTH00290037) on Town Highway 29, crossing Mill Brook, Townshend, Vermont

    USGS Publications Warehouse

    Burns, R.L.; Medalie, Laura

    1998-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 2.1 ft. The worst-case contraction scour occurred at the 500-year discharge. Left abutment scour ranged from 6.7 to 8.7 ft. The worst-case left abutment scour occurred at the incipient roadway-overtopping discharge. Right abutment scour ranged from 7.8 to 9.5 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 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 Davis, 1995, p. 46). 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 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.

  18. 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...

  19. 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,…

  20. Enhanced drug encapsulation and extended release profiles of calcium-alginate nanoparticles by using tannic acid as a bridging cross-linking agent.

    PubMed

    Abulateefeh, Samer R; Taha, Mutasem O

    2015-01-01

    Calcium alginate nanoparticles (NPs) suffer from sub-optimal stability in bio-relevant media leading to low drug encapsulation efficiency and uncontrolled release profiles. To sort out these drawbacks, a novel approach is proposed herein based on introducing tannic acid into these NPs to act as a bridging cross-linking aid agent. Calcium-alginate NPs were prepared by the ionotropic gelation method and loaded with diltiazem hydrochloride as a model drug. These NPs were characterized in terms of particle size, zeta potential, and morphology, and results were explained in accordance with Fourier-transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The incorporation of tannic acid led to more than four folds increase in drug encapsulation efficiency (i.e. from 15.3% to 69.5%) and reduced burst drug release from 44% to around 10% within the first 30 min. These findings suggest the possibility of improving the properties of Ca-alginate NPs by incorporating cross-linking aid agents under mild conditions.

  1. Level II scour analysis for Bridge 46 (CHESVT00110046) on Vermont State Route 11, crossing the Middle Branch Williams River, Chester, Vermont

    USGS Publications Warehouse

    Wild, Emily C.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure CHESVT00110046 on State Route 11 crossing the Middle 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 Green Mountain and New England Upland sections of the New England physiographic province in southeastern Vermont. The 28.0-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forested on the upstream left and downstream right overbanks. The upstream right and downstream left overbanks are pasture while the immediate banks have dense woody vegetation.In the study area, the the Middle Branch Williams River has an incised, sinuous channel with a slope of approximately 0.013 ft/ft, an average channel top width of 81 ft and an average bank height of 11 ft. The channel bed material ranges from gravel to bedrock with a median grain size (D50) of 70.7 mm (0.232 ft). The geomorphic assessment at the time of the Level I and Level II site visit on September 12, 1996, indicated that the reach was stable.The State Route 11 crossing of the Middle Branch Williams River is a 118-ft-long, two-lane steel stringer type bridge consisting of a 114-foot steel plate deck (Vermont Agency of Transportation, written communication, March 29, 1995). The opening length of the structure parallel to the bridge face is 109 ft.The bridge is supported by vertical, concrete abutments with

  2. Level II scour analysis for Bridge 25 (REDSTH00360025) on Town Highway 36, crossing the West Branch Deerfield River, Readsboro, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Burns, Ronda L.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure REDSTH00360025 on Town Highway 36 crossing the West Branch Deerfield River, Readsboro, 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 14.5-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 upstream right bank and forest on the upstream left bank. The surface cover on the downstream right and left banks is primarily grass, shrubs and brush. In the study area, the West Branch Deerfield River has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 65 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 117 mm (0.383 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 1, 1996, indicated that the reach was stable. The Town Highway 36 crossing of the West Branch Deerfield River is a 59-ft-long, two-lane bridge consisting of one 57-foot concrete T-beam span (Vermont Agency of Transportation, written communication, September 28, 1995). The opening length of the structure parallel to the bridge face is 54 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 50

  3. Level II scour analysis for Bridge 41 (ANDOVT00110041) on State Route 11, crossing the Middle Branch Williams River, Andover, 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 ANDOVT00110041 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 southeastern Vermont. The 12.1-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is grass on the upstream right overbank while the immediate banks have dense woody vegetation. The upstream left overbank and downstream right overbank are brushland. The downstream left overbank is forested. In the study area, the Middle Branch Williams River has an incised, sinuous channel with a slope of approximately 0.018 ft/ft, an average channel top width of 71 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 85.0 mm (0.279 ft). The geomorphic assessment at the time of the Level I and Level II site visit on September 10, 1996, indicated that the reach was laterally unstable due to a cut-bank present on the upstream right bank and a wide channel bar with vegetation in the upstream reach. The State Route 11 crossing of the Middle Branch Williams River is a 46-ft-long, two-lane bridge consisting of a concrete 44-foot tee-beam span (Vermont Agency of Transportation, written communication, March 29, 1995). The opening length of

  4. 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

  5. Level II scour analysis for Bridge 16 (RIPTTH00110016) on Town Highway 11, crossing the Middle Branch Middlebury River, Ripton, 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 RIPTTH00110016 on Town Highway 11 crossing the Middle Branch Middlebury River, Ripton, 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 west-central Vermont. The 6.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover consists of shrubs, brush and trees except for the upstream left bank which is completely forested. In the study area, the Middle Branch Middlebury River has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 68 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 97.6 mm (0.320 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 11, 1996, indicated that the reach was stable. The Town Highway 11 crossing of the Middle Branch Middlebury River is a 44-ft-long, two-lane bridge consisting of one 42-foot steel-beam span (Vermont Agency of Transportation, written communication, December 15, 1995). The opening length of the structure parallel to the bridge face is 40.2 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 40 degrees to the opening. The opening-skew-to-roadway value from the VTAOT

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. Sound localization in hemispherectomized subjects: the contribution of crossed and uncrossed cortical afferents.

    PubMed

    Lessard, N; Lepore, F; Poirier, P; Villemagne, J; Lassonde, M

    2000-10-01

    The aim of the present study was to evaluate how hemispherectomized subjects localize sounds in free field using residual auditory structures under monaural testing conditions. The main objective of using a monaural condition with these subjects, who lack the terminal fields of auditory projections on one side, was to evaluate how the crossed and uncrossed pathways compare, with the aim of resolving this biologically critical function. In this model, crossed and uncrossed inputs refer to auditory stimulation presented to the unobstructed ear on the contralateral and the ipsilateral side of the intact hemisphere, respectively. Three hemispherectomized subjects (Hs) and ten control subjects (Cs) were tested for their accuracy to localize broad band noise bursts (BBNBs) of fixed intensity presented on the horizontal plane. BBNBs were delivered randomly through 16 loudspeakers mounted at 10 degrees intervals on a calibrated perimeter frame located inside an anechoic chamber. Subjects had to report the apparent stimulus location by pointing to its perceived position on the perimeter. Hs were less accurate than Cs in the baseline binaural condition, confirming the finding that with a single hemisphere and/or residual (subcortical) structures they cannot analyze binaural cues to sound localization as efficiently as with two fully functional hemispheres. In the monaural condition, Hs localized poorly when they had to depend on the uncrossed input, but performed as well or even better than the Cs with the crossed input. These findings suggest that monaural spectral cues, which constitute the only residual cue to localization under the monaural testing condition, are treated more efficiently, that is, they lead to better localization performance when relayed to the cortex via crossed pathways than through uncrossed pathways.

  12. 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,…

  13. 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

  14. 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

  15. Level II scour analysis for Bridge 39 (ANDOVT00110039) on State Route 11, crossing the Middle Branch Williams River, Andover, Vermont

    USGS Publications Warehouse

    Burns, Ronda L.; Wild, Emily C.

    1997-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure ANDOVT00110039 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 southern Vermont. The 5.75-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest on the upstream left bank and downstream right bank. The surface cover on the upstream right and downstream left banks is brush. In the study area, the Middle Branch Williams River has an incised, sinuous channel with a slope of approximately 0.01 ft/ft, an average channel top width of 58 ft and an average bank height of 8 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 96.8 mm (0.317 ft). The geomorphic assessment at the time of the Level I and Level II site visit on September 9, 1996, indicated that the reach was laterally unstable. The State Route 11 crossing of the Middle Branch Williams River is a 43-ft-long, two-lane bridge consisting of one 41-foot concrete-beam span and two additional steel beams on the upstream face (Vermont Agency of Transportation, written communication, March 29, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 45 degrees to the opening while the opening

  16. X-ray Diffraction Evidence for Low Force Actin-Attached and Rigor-Like Cross-Bridges in the Contractile Cycle

    PubMed Central

    Eakins, Felicity; Pinali, Christian; Gleeson, Anthony; Knupp, Carlo; Squire, John M.

    2016-01-01

    Defining the structural changes involved in the myosin cross-bridge cycle on actin in active muscle by X-ray diffraction will involve recording of the whole two dimensional (2D) X-ray diffraction pattern from active muscle in a time-resolved manner. Bony fish muscle is the most highly ordered vertebrate striated muscle to study. With partial sarcomere length (SL) control we show that changes in the fish muscle equatorial A-band (10) and (11) reflections, along with (10)/(11) intensity ratio and the tension, are much more rapid than without such control. Times to 50% change with SL control were 19.5 (±2.0) ms, 17.0 (±1.1) ms, 13.9 (±0.4) ms and 22.5 (±0.8) ms, respectively, compared to 25.0 (±3.4) ms, 20.5 (±2.6) ms, 15.4 (±0.6) ms and 33.8 (±0.6) ms without control. The (11) intensity and the (10)/(11) intensity ratio both still change ahead of tension, supporting the likelihood of the presence of a head population close to or on actin, but producing little or no force, in the early stages of the contractile cycle. Higher order equatorials (e.g., (30), (31), and (32)), more sensitive to crossbridge conformation and distribution, also change very rapidly and overshoot their tension plateau values by a factor of around two, well before the tension plateau has been reached, once again indicating an early low-force cross-bridge state in the contractile cycle. Modelling of these intensity changes suggests the presence of probably two different actin-attached myosin head structural states (mainly low-force attached and rigor-like). No more than two main attached structural states are necessary and sufficient to explain the observations. We find that 48% of the heads are off actin giving a resting diffraction pattern, 20% of heads are in the weak binding conformation and 32% of the heads are in the strong (rigor-like) state. The strong states account for 96% of the tension at the tetanus plateau. PMID:27792170

  17. Assessment of Baroreflex Contribution to Spontaneous Blood Pressure-Heart Rate Coupling by Cross Mutual Information

    DTIC Science & Technology

    2007-11-02

    variability during spontaneous behavior and 2) identify the relative contribution of the arterial baroreflex in the production of this coupling. The...days after the opening of the baroreflex loop. This allowed us to determine the baseline level of the SBP-PI coupling in intact conditions and the...remaining fraction of SBP-PI coupling surviving deactivation of the baroreflex control function. We observed that in intact animals the cumulative

  18. 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.

  19. Blood pressure and culture. The contribution of cross-cultural comparisons to psychosomatics.

    PubMed

    Murphy, H B

    1982-01-01

    It is well known that mean blood pressure levels tend to be low in non-westernized tribal peoples and that these levels tend to rise, particularly in the older age groups, among persons of the same origins who come into more contact with modern Western life-styles. That tendency can be attributed to many factors - increased salt intake, increased obesity, acculturation anxiety, information overload, increased competitiveness, envious resentment, etc. Disentangling these various hypothesized factors is virtually impossible when studying patients or population samples from a single sociocultural group, but cross-cultural comparisons may under favorable circumstances permit some such disentangling. Using data from Micronesia, Polynesia, and East Africa, an attempt will be made to assess which types of psychological stress are most likely to conduce to hypertension, and how certain traditional cultures may have been reducing these stresses.

  20. Level II scour analysis for Bridge 9 (JAYVT02420009) on Vermont Highway 242, crossing the Jay Branch of the Missisquoi River, Jay, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Ivanoff, Michael A.

    1996-01-01

    Contraction scour for all modelled flows ranged from 0.0 to 0.6 ft. The worst-case contraction scour occurred at the 100-year discharge. Abutment scour ranged from 0.8 to 5.6 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.

  1. Cross-bridge cycling gives rise to spatiotemporal heterogeneity of dynamic subcellular mechanics in cardiac myocytes probed with atomic force microscopy.

    PubMed

    Azeloglu, Evren U; Costa, Kevin D

    2010-03-01

    To study how the dynamic subcellular mechanical properties of the heart relate to the fundamental underlying process of actin-myosin cross-bridge cycling, we developed a novel atomic force microscope elastography technique for mapping spatiotemporal stiffness of isolated, spontaneously beating neonatal rat cardiomyocytes. Cells were indented repeatedly at a rate close but unequal to their contractile frequency. The resultant changes in pointwise apparent elastic modulus cycled at a predictable envelope frequency between a systolic value of 26.2 +/- 5.1 kPa and a diastolic value of 7.8 +/- 4.1 kPa at a representative depth of 400 nm. In cells probed along their major axis, spatiotemporal changes in systolic stiffness displayed a heterogeneous pattern, reflecting the banded sarcomeric structure of underlying myofibrils. Treatment with blebbistatin eliminated contractile activity and resulted in a uniform apparent modulus of 6.5 +/- 4.8 kPa. This study represents the first quantitative dynamic mechanical mapping of beating cardiomyocytes. The technique provides a means of probing the micromechanical effects of disease processes and pharmacological treatments on beating cardiomyocytes, providing new insights and relating subcellular cardiac structure and function.

  2. Level II scour analysis for Bridge 120 (LEICUS00070120) on U.S. Route 7, crossing the Leicester River, Leicester, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Severance, Timothy

    1997-01-01

    Contraction scour for all modelled flows ranged from 3.8 to 6.1 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.0 to 6.7 ft. The worst-case abutment scour also occurred at the 500-year discharge. Pier scour ranged from 9.1 to 10.2. 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.

  3. Level II scour analysis for Bridge 38 (RANDTH00640038) on Town Highway 64, crossing the Second Branch of the White River, Randolph, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    Contraction scour for all modelled flows ranged from 1.7 to 2.6 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.2 to 24.2 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. The Role of Parvalbumin, Sarcoplasmatic Reticulum Calcium Pump Rate, Rates of Cross-Bridge Dynamics, and Ryanodine Receptor Calcium Current on Peripheral Muscle Fatigue: A Simulation Study

    PubMed Central

    Neumann, Verena

    2016-01-01

    A biophysical model of the excitation-contraction pathway, which has previously been validated for slow-twitch and fast-twitch skeletal muscles, is employed to investigate key biophysical processes leading to peripheral muscle fatigue. Special emphasis hereby is on investigating how the model's original parameter sets can be interpolated such that realistic behaviour with respect to contraction time and fatigue progression can be obtained for a continuous distribution of the model's parameters across the muscle units, as found for the functional properties of muscles. The parameters are divided into 5 groups describing (i) the sarcoplasmatic reticulum calcium pump rate, (ii) the cross-bridge dynamics rates, (iii) the ryanodine receptor calcium current, (iv) the rates of binding of magnesium and calcium ions to parvalbumin and corresponding dissociations, and (v) the remaining processes. The simulations reveal that the first two parameter groups are sensitive to contraction time but not fatigue, the third parameter group affects both considered properties, and the fourth parameter group is only sensitive to fatigue progression. Hence, within the scope of the underlying model, further experimental studies should investigate parvalbumin dynamics and the ryanodine receptor calcium current to enhance the understanding of peripheral muscle fatigue. PMID:27980606

  5. The Role of Parvalbumin, Sarcoplasmatic Reticulum Calcium Pump Rate, Rates of Cross-Bridge Dynamics, and Ryanodine Receptor Calcium Current on Peripheral Muscle Fatigue: A Simulation Study.

    PubMed

    Röhrle, Oliver; Neumann, Verena; Heidlauf, Thomas

    2016-01-01

    A biophysical model of the excitation-contraction pathway, which has previously been validated for slow-twitch and fast-twitch skeletal muscles, is employed to investigate key biophysical processes leading to peripheral muscle fatigue. Special emphasis hereby is on investigating how the model's original parameter sets can be interpolated such that realistic behaviour with respect to contraction time and fatigue progression can be obtained for a continuous distribution of the model's parameters across the muscle units, as found for the functional properties of muscles. The parameters are divided into 5 groups describing (i) the sarcoplasmatic reticulum calcium pump rate, (ii) the cross-bridge dynamics rates, (iii) the ryanodine receptor calcium current, (iv) the rates of binding of magnesium and calcium ions to parvalbumin and corresponding dissociations, and (v) the remaining processes. The simulations reveal that the first two parameter groups are sensitive to contraction time but not fatigue, the third parameter group affects both considered properties, and the fourth parameter group is only sensitive to fatigue progression. Hence, within the scope of the underlying model, further experimental studies should investigate parvalbumin dynamics and the ryanodine receptor calcium current to enhance the understanding of peripheral muscle fatigue.

  6. 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.

  7. Level II scour analysis for Bridge 34 (SHERUS00040034) on U.S. Highway 4, crossing the Ottauquechee River, Sherburne, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.; Severance, Timothy

    1997-01-01

    Contraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 4.7 to 7.4 ft. The worst-case abutment scour occurred at the left abutment for the 500-year discharge. Pier scour ranged from 7.5 to 11.4 ft. The worst-case pier scour occurred at the incipientovertopping 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. Level II scour analysis for Bridge 24 (HARDTH00490024) on Town Highway 49, crossing Nichols Brook at Mackville Pond Outlet, Hardwick, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    Contraction scour for all modelled flows ranged from 4.7 to 21.0 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour at the left abutment ranged from 13.3 to 15.8 ft. with the worst-case occurring at the 500-year discharge. Abutment scour at the right abutment ranged from 8.1 to 9.8 ft. with the worst-case occurring at the incipient roadway-overtopping 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.

  9. Level II scour analysis for Bridge 22 (REDSVT01000022) on State Route 100, crossing the West Branch Deerfield River, Readsboro, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.; Burns, Ronda L.

    1997-01-01

    There was no predicted contraction scour for any of the modelled flows. Abutment scour ranged from 4.9 to 11.6 ft. The worst-case abutment scour occurred at the right abutment for the 500-year discharge. However, historical information indicates the right abutment is in contact with bedrock at least in part. 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 81 (MARSUS00020081) on U.S. Highway 2, crossing the Winooski River, Marshfield, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.

    1997-01-01

    Contraction scour for all modelled flows ranged from 2.1 to 4.2 ft. The worst-case contraction scour occurred at the 500-year discharge. Left abutment scour ranged from 14.3 to 14.4 ft. The worst-case left abutment scour occurred at the incipient roadwayovertopping and 500-year discharge. Right abutment scour ranged from 15.3 to 18.5 ft. The worst-case right abutment scour occurred at the 100-year and the incipient roadwayovertopping 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) give “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. 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.

  12. 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

  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. Level II scour analysis for Bridge 45b (BRIDTH00040045b) on Town Highway 4, crossing an unnamed Dailey Hollow Branch Tributary, Bridgewater, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure BRIDTH0004045B on town highway 4 crossing an unnamed Dailey Hollow Branch Tributary, 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 in central Vermont. The 2.47-mi2 drainage area is in a predominantly rural and forested basin. Surface cover in the vicinity of the study site is variable. A gravel road is adjacent to the left bank with the immediate upstream left bank covered by grass and the immediate downstream left bank covered by shrubs and brush. The upstream right bank is densely forested; the downstream right overbank is covered by grass with trees and brush on the immediate channel bank. In the study area, this unnamed Dailey Hollow Branch Tributary has an incised channel with a slope of approximately 0.04 ft/ft, an average channel top width of 29 ft and an average channel depth of 4 ft. The predominant channel bed material is gravel with a median grain size (D50) of 47.0 mm (0.154 ft). The geomorphic assessment at the time of the Level I and Level II site visit on November 15, 1994, indicated that the reach was stable. The town highway 4 crossing of the unnamed Dailey Hollow Branch Tributary is a 62-ft-long, corrugated steel multi-plate arch structure. It is supported by concrete footings leaving natural stream bed exposed (Vermont Agency of Transportation, written

  15. Variations in cross-bridge attachment rate and tension with phosphorylation of myosin in mammalian skinned skeletal muscle fibers. Implications for twitch potentiation in intact muscle

    PubMed Central

    1989-01-01

    The Ca2+ sensitivities of the rate constant of tension redevelopment (ktr; Brenner, B., and E. Eisenberg. 1986. Proceedings of the National Academy of Sciences. 83:3542-3546) and isometric force during steady- state activation were examined as functions of myosin light chain 2 (LC2) phosphorylation in skinned single fibers from rabbit and rat fast- twitch skeletal muscles. To measure ktr the fiber was activated with Ca2+ and steady isometric tension was allowed to develop; subsequently, the fiber was rapidly (less than 1 ms) released to a shorter length and then reextended by approximately 200 nm per half sarcomere. This maneuver resulted in the complete dissociation of cross-bridges from actin, so that the subsequent redevelopment of tension was related to the rate of cross-bridge reattachment. The time course of tension redevelopment, which was recorded under sarcomere length control, was best fit by a first-order exponential equation (i.e., tension = C(1 - e- kt) to obtain the value of ktr. In control fibers, ktr increased sigmoidally with increases in [Ca2+]; maximum values of ktr were obtained at pCa 4.5 and were significantly greater in rat superficial vastus lateralis fibers (26.1 +/- 1.2 s-1 at 15 degrees C) than in rabbit psoas fibers (18.7 +/- 1.0 s-1). Phosphorylation of LC2 was accomplished by repeated Ca2+ activations (pCa 4.5) of the fibers in solutions containing 6 microM calmodulin and 0.5 microM myosin light chain kinase, a protocol that resulted in an increase in LC2 phosphorylation from approximately 10% in the control fibers to greater than 80% after treatment. After phosphorylation, ktr was unchanged at maximum or very low levels of Ca2+ activation. However, at intermediate levels of Ca2+ activation, between pCa 5.5 and 6.2, there was a significant increase in ktr such that this portion of the ktr-pCa relationship was shifted to the left. The steady-state isometric tension-pCa relationship, which in control fibers was left shifted with respect

  16. 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…

  17. 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

  18. Influence of calcium(II) and chloride on the oxidative reactivity of a manganese(II) complex of a cross-bridged cyclen ligand.

    PubMed

    Zhang, Zhan; Coats, Katherine L; Chen, Zhuqi; Hubin, Timothy J; Yin, Guochuan

    2014-11-17

    Available data from different laboratories have confirmed that both Ca(2+) and Cl(-) are crucial for water oxidation in Photosystem II. However, their roles are still elusive. Using a manganese(II) complex having a cross-bridged cyclen ligand as a model, the influence of Ca(2+) on the oxidative reactivity of the manganese(II) complex and its corresponding manganese(IV) analogue were investigated. It has been found that adding Ca(2+) can significantly improve the oxygenation efficiency of the manganese(II) complex in sulfide oxidation and further accelerate the oxidation of sulfoxide to sulfone. Similar improvements have also been observed for Mg(2+), Sr(2+), and Ba(2+). A new monomeric manganese(IV) complex having two cis-hydroxide ligands has also been isolated through oxidation of the corresponding manganese(II) complex with H2O2 in the presence of NH4PF6. This rare cis-dihydroxomanganese(IV) species has been well characterized by X-ray crystallography, electrochemistry, electron paramagnetic resonance, and UV-vis spectroscopy. Notably, using the manganese(IV) complex as a catalyst demonstrates higher activity than the corresponding manganese(II) complex, and adding Ca(2+) further improves its catalytic efficiency. However, adding Cl(-) decreases its catalytic activity. In electrochemical studies of manganese(IV) complexes with no chloride ligand present, adding Ca(2+) positively shifted the redox potential of the Mn(IV)/Mn(III) couple but negatively shifted its Mn(V)/Mn(IV) couple. In the manganese(II) complex having a chloride ligand, adding Ca(2+) shifted both the Mn(IV)/Mn(III) and Mn(V)/Mn(IV) couples in the negative direction. The revealed oxidative reactivity and redox properties of the manganese species affected by Ca(2+) and Cl(-) may provide new clues to understanding their roles in the water oxidation process of Photosystem II.

  19. 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.

  20. Do circulating blood cells contribute to maternal tissue remodeling and embryo-maternal cross-talk around the implantation period?

    PubMed

    Fujiwara, Hiroshi

    2009-06-01

    In early pregnancy, human chorionic gonadotrophin (HCG) stimulates the corpus luteum (CL) of pregnancy to produce progesterone, which in turn maintains human embryo implantation in the uterus. In addition to this embryo-maternal cross-talk via the endocrine systems through blood circulation, accumulating evidence suggests that circulating blood cells also play an important role in embryo implantation. Peripheral blood mononuclear cells (PBMC) derived from pregnant women increased the progesterone production by luteal cells and promoted the invasion of embryos in vitro. Recombinant-HCG increased chemokine production by PBMC through lectin-glycan interaction and enhanced the effects of PBMC on embryo invasion. Later, it was shown that not only PBMC, but also circulating platelets were possible sources of these chemokines that promote extravillous trophoblast invasion to reconstruct maternal endometrial artery. Circulating platelets were also proposed to induce neovascularization during CL formation. Furthermore, intrauterine administration of autologous PBMC effectively improved live birth, pregnancy and implantation rates in patients with repeated (four or more) implantation failures during in vitro fertilization therapy. These findings suggest that circulating blood cells positively contribute to maternal tissue remodeling and embryo-maternal cross-talk around the implantation period in cooperation with the endocrine system.

  1. Morphological aspects of myocardial bridges.

    PubMed

    Lujinović, Almira; Kulenović, Amela; Kapur, Eldan; Gojak, Refet

    2013-11-01

    Although some myocardial bridges can be asymptomatic, their presence often causes coronary disease either through direct compression of the "tunnel" segment or through stimulation and accelerated development of atherosclerosis in the segment proximally to the myocardial bridge. The studied material contained 30 human hearts received from the Department of Anatomy. The hearts were preserved 3 to 5 days in 10% formalin solution. Thereafter, the fatty tissue was removed and arterial blood vessels prepared by careful dissection with special reference to the presence of the myocardial bridges. Length and thickness of the bridges were measured by the precise electronic caliper. The angle between the myocardial bridge fibre axis and other axis of the crossed blood vessel was measured by a goniometer. The presence of the bridges was confirmed in 53.33% of the researched material, most frequently (43.33%) above the anterior interventricular branch. The mean length of the bridges was 14.64 ± 9.03 mm and the mean thickness was 1.23 ± 1.32 mm. Myocardial bridge fibres pass over the descending blood vessel at the angle of 10-90 degrees. The results obtained on a limited sample suggest that the muscular index of myocardial bridge is the highest for bridges located on RIA, but that the difference is not significant in relation to bridges located on other branches. The results obtained suggest that bridges located on other branches, not only those on RIA, could have a great contractive power and, consequently, a great compressive force, which would be exerted on the wall of a crossed blood vessel.

  2. 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

  3. The contribution of traditional healers' clinics to public health care system in Addis Ababa, Ethiopia: a cross-sectional study

    PubMed Central

    2011-01-01

    Background Ethiopian people have been using traditional medicine since time immemorial with 80% of its population dependent on traditional medicines. However, the documentation of traditional healers' clinics contribution to modern public health system in cosmopolitan cities is scanty. Studies conducted so far are limited and focused on the perceptions and practices of modern and traditional health practitioners about traditional medicine. Thus, a cross sectional study was conducted from February to May 2010 to assess the contribution of traditional healers' clinics to public health care system in Addis Ababa. Materials and methods Ten traditional healers who were willing to participate in the study and 306 patients who were visiting these traditional healers' clinics were interviewed using two types of semi-structured questionnaires. Data were summarized using percentages, tables and bar chart. Results The diseases mostly treated by traditional healers were wound, inflammation, herpes zoster, hemorrhoids, fracture, paralysis, back-pain, liver diseases, cancer and eczema. This study showed that traditional healers' clinics considerably contribute to public health care in Addis Ababa. Fifty two percent of patients reported that traditional healers' clinics were their first choice when they faced health problems. The reasons for visiting these clinics were 175 (57.2%) efficacy, 109 (35.6%) dissatisfaction with modern medicine, 10 (3.3%) dissatisfaction with modern medicine and efficacy, 6 (2.0%) cost and 6 (2.0%) dissatisfaction and cost. Females (55.2%), young age (20-40 years, 65.0%), never married (56.9%), orthodox (73.9%), Amhara (52.3%), educational status above grade 12 (34.6%) and government employees (29.4%) were frequent visitors. Healers reported that there was no form of cooperation with modern health professionals. The reasons were lack of motivation to collaborate and communicate with modern health service workers. Family based apprenticeship was the

  4. Vulnerability of drinking-water wells in La Crosse, Wisconsin, to enteric-virus contamination from surface water contributions

    USGS Publications Warehouse

    Borchardt, M. A.; Haas, N.L.; Hunt, R.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.

  5. 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

  6. Vulnerability of drinking-water wells in La Crosse, Wisconsin, to enteric-virus contamination from surface water contributions.

    PubMed

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

    2004-10-01

    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. (18)O/(16)O and (2)H/(1)H 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.

  7. Increased translocation of antigens to endosomes and TLR4 mediated endosomal recruitment of TAP contribute to nicotine augmented cross-presentation.

    PubMed

    Wang, Yan Yan; Hu, Chun Fang; Li, Juan; You, Xiang; Gao, Feng Guang

    2016-06-21

    Cross-presentation by dendritic cells (DCs) requires surface molecules such as lectin, CD40, langerin, heat shock protein, mannose receptor, mediated endocytosis, the endosomal translocation of internalized antigen, and the relocation of transporter associated with antigen processing (TAP). Although the activation of α7 nicotinic acetylcholine receptor (α7 nAchR) up-regulate surface molecule expression, augment endocytosis, and enhance cross-presentation, the molecular mechanism of α7 nAchR activation-increased cross-presentation is still poorly understood. In this study, we investigated the role of mannose receptor in nicotine-increased cross-presentation and the mechanism that endotoxins orchestrating the recruitment of TAP toward endosomes. We demonstrated that nicotine increase the expressiones of mannose receptor and Toll-like receptor 4 (TLR4) via PI3K-Akt-mTOR-p70S6 pathway. Both endosomal translocation of mannose receptor-internalized antigens and TLR4 sig- naling are necessary for nicotine-augmented cross-presentation and cross-priming. Importantly, the recruitment of TAP toward endosomes via TLR4-MyD88-IRAK4 signaling contributes to nicotine-increased cross-presentation and cross-activation of T cells. Thus, these data suggest that increased recruitment of TAP to Ag-containing vesicles contributes to the superior cross-presentation efficacy of α7 nAchR activated DCs.

  8. 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.

  9. Binuclear Phthalocyanines with Aromatic Bridges

    DTIC Science & Technology

    1989-03-01

    successful. (Scheme 2) Synthesis of Binuclear Phthalocyanines Covalently Bridged by Anthracene The coupling reaction of aromatic halides using elemental...available (16), it Is not active enough to undergo the desired cross coupling reaction . Less electropositive arylzinc derivatives can tolerate various electro...philic functional groups such as nitriles and esters (17). These organo- metallic reagents readily undergo cross coupling reaction with aryl halides

  10. Sensory Feedback in Interlimb Coordination: Contralateral Afferent Contribution to the Short-Latency Crossed Response during Human Walking

    PubMed Central

    Gervasio, Sabata; Voigt, Michael; Kersting, Uwe G.; Farina, Dario; Sinkjær, Thomas

    2017-01-01

    A constant coordination between the left and right leg is required to maintain stability during human locomotion, especially in a variable environment. The neural mechanisms underlying this interlimb coordination are not yet known. In animals, interneurons located within the spinal cord allow direct communication between the two sides without the need for the involvement of higher centers. These may also exist in humans since sensory feedback elicited by tibial nerve stimulation on one side (ipsilateral) can affect the muscles activation in the opposite side (contralateral), provoking short-latency crossed responses (SLCRs). The current study investigated whether contralateral afferent feedback contributes to the mechanism controlling the SLCR in human gastrocnemius muscle. Surface electromyogram, kinematic and kinetic data were recorded from subjects during normal walking and hybrid walking (with the legs moving in opposite directions). An inverse dynamics model was applied to estimate the gastrocnemius muscle proprioceptors’ firing rate. During normal walking, a significant correlation was observed between the magnitude of SLCRs and the estimated muscle spindle secondary afferent activity (P = 0.04). Moreover, estimated spindle secondary afferent and Golgi tendon organ activity were significantly different (P ≤ 0.01) when opposite responses have been observed, that is during normal (facilitation) and hybrid walking (inhibition) conditions. Contralateral sensory feedback, specifically spindle secondary afferents, likely plays a significant role in generating the SLCR. This observation has important implications for our understanding of what future research should be focusing on to optimize locomotor recovery in patient populations. PMID:28060839

  11. Contributions of long-range and regional atmospheric transport on pesticide concentrations along a transect crossing a mountain divide.

    PubMed

    Lavin, Karen S; Hageman, Kimberly J

    2013-02-05

    Twenty-one halogenated legacy and current-use pesticides and pesticide degradation products were measured in pine needles along a coast-to-coast transect that crossed the Southern Alps of New Zealand. Concentration profiles of nine pesticides were used to determine the influence of geographic sources on the atmospheric pesticide burden at the mountain sites. Pesticide concentration profiles were calculated for each source and mountain site by normalizing concentrations (adjusted for temperature at the site and air-needle partitioning) to the sum of all pesticide concentrations at the site. Each mountain site profile was compared to varying mixtures of the potential source profiles to determine the percent contribution of each source. The highest elevation mountain sites were primarily influenced by long-range, synoptic-scale northwesterly winds. Westerly upslope winds had little influence on any of the mountain sites. Easterly upslope winds from the Canterbury Plains, an agricultural region, strongly influenced the mountain sites within close proximity and had progressively less influence with distance.

  12. Psychometric characteristics of the Penn State Worry Questionnaire in an Argentinean sample: a cross-cultural contribution.

    PubMed

    Rodríguez-Biglieri, Ricardo; Vetere, Giselle Lorena

    2011-05-01

    Although studies in several populations have provided support for Penn State Worry Questionnaire (PSQW) reliability and validity, factor analysis studies carried out on different populations show divergent results. The aim of this article is to contribute with the cross-cultural literature on PSWQ. This report describes two studies examining the psychometric characteristics of a revised Argentinean version of the PSWQ. In the first study, items of original PSWQ were translated into Spanish and then back-translated into English. Then, in order to examine its reliability and factorial structure, the instrument was completed by 400 community participants. The second study included two groups of participants as follows: patients with generalized anxiety disorder (GAD), and patients with other anxiety disorders (AC). Results revealed appropriated test-retest reliability over a four-week period, high internal consistency, and good convergent and discriminant validity for PSWQ. In concordance with some results reported in previous studies, a single factorial structure was confirmed for the Argentinean version of PSWQ. By the other hand, a receiver operating characteristic analysis was made to evaluate the ability of PSWQ to discriminate GAD from individuals with others anxiety disorders. A total score of 63 simultaneously optimized sensitivity and specificity in discriminating GAD patients from patients with others anxiety disorders.

  13. 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

  14. A nanofibrous PHBV tube with Schwann cell as artificial nerve graft contributing to rat sciatic nerve regeneration across a 30-mm defect bridge.

    PubMed

    Biazar, Esmaeil; Heidari Keshel, Saeed

    2013-02-01

    A nanofibrous PHBV nerve conduit has been used to evaluate its efficiency based on the promotion of nerve regeneration in rats. The designed conduits were investigated by physical, mechanical and microscopic analyses. The conduits were implanted into a 30-mm gap in the sciatic nerves of the rats. Four months after surgery, the regenerated nerves were evaluated by macroscopic assessments and histology. This polymeric conduit had sufficiently high mechanical properties to serve as a nerve guide. The results demonstrated that in the nanofibrous graft with cells, the sciatic nerve trunk had been reconstructed with restoration of nerve continuity and formatted nerve fibers with myelination. For the grafts especially the nanofibrous conduits with cells, muscle cells of gastrocnemius on the operated side were uniform in their size and structures. This study proves the feasibility of artificial conduit with Schwann cells for nerve regeneration by bridging a longer defect in a rat model.

  15. Cross-species chromosome painting in bats from Madagascar: the contribution of Myzopodidae to revealing ancestral syntenies in Chiroptera.

    PubMed

    Richards, Leigh R; Rambau, Ramugondo V; Lamb, Jennifer M; Taylor, Peter J; Yang, Fengtang; Schoeman, M Corrie; Goodman, Steven M

    2010-09-01

    The chiropteran fauna of Madagascar comprises eight of the 19 recognized families of bats, including the endemic Myzopodidae. While recent systematic studies of Malagasy bats have contributed to our understanding of the morphological and genetic diversity of the island's fauna, little is known about their cytosystematics. Here we investigate karyotypic relationships among four species, representing four families of Chiroptera endemic to the Malagasy region using cross-species chromosome painting with painting probes of Myotis myotis: Myzopodidae (Myzopoda aurita, 2n = 26), Molossidae (Mormopterus jugularis, 2n = 48), Miniopteridae (Miniopterus griveaudi, 2n = 46), and Vespertilionidae (Myotis goudoti, 2n = 44). This study represents the first time a member of the family Myzopodidae has been investigated using chromosome painting. Painting probes of M. myotis were used to delimit 29, 24, 23, and 22 homologous chromosomal segments in the genomes of M. aurita, M. jugularis, M. griveaudi, and M. goudoti, respectively. Comparison of GTG-banded homologous chromosomes/chromosomal segments among the four species revealed the genome of M. aurita has been structured through 14 fusions of chromosomes and chromosomal segments of M. myotis chromosomes leading to a karyotype consisting solely of bi-armed chromosomes. In addition, chromosome painting revealed a novel X-autosome translocation in M. aurita. Comparison of our results with published chromosome maps provided further evidence for karyotypic conservatism within the genera Mormopterus, Miniopterus, and Myotis. Mapping of chromosomal rearrangements onto a molecular consensus phylogeny revealed ancestral syntenies shared between Myzopoda and other bat species of the infraorders Pteropodiformes and Vespertilioniformes. Our study provides further evidence for the involvement of Robertsonian (Rb) translocations and fusions/fissions in chromosomal evolution within Chiroptera.

  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. Elevation of Warrington Avenue Bridge and cut stone retaining wall ...

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

    Elevation of Warrington Avenue Bridge and cut stone retaining wall southbound on Warrington Avenue - Pittsburgh & Castle Shannon Railroad, Warrington Avenue Bridge, Overbrook Trolley Line, Crossing Warrington Avenue, Pittsburgh, Allegheny County, PA

  18. 17. VIEW OF NORTH BRIDGE PORTAL, SHOWING ORNAMENTAL UPPER PORTAL ...

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

    17. VIEW OF NORTH BRIDGE PORTAL, SHOWING ORNAMENTAL UPPER PORTAL STRUT AND GEOMETRIC DECORATED GUSSET. FACING NORTHEAST. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

  19. 15. VIEW OF SOUTH BRIDGE PORTAL, SHOWING ORNAMENTAL UPPER PORTAL ...

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

    15. VIEW OF SOUTH BRIDGE PORTAL, SHOWING ORNAMENTAL UPPER PORTAL STRUT AND GUSSETS (FLORAL MOTIF). FACING SOUTHWEST. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

  20. 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

  1. 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

  2. 33 CFR 115.50 - Application for bridge permits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... courts, the power to authorize the construction of bridges, they must furnish with their application... reference to the planes of mean high water and mean low water if the bridge is to cross tidal water. If...

  3. 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

  4. Why Are Two Different Cross-linkers Necessary for Actin Bundle Formation In Vivo and What Does Each Cross-link Contribute?

    PubMed Central

    Tilney, Lewis G.; Connelly, Patricia S.; Vranich, Kelly A.; Shaw, Michael K.; Guild, Gregory M.

    1998-01-01

    In developing Drosophila bristles two species of cross-linker, the forked proteins and fascin, connect adjacent actin filaments into bundles. Bundles form in three phases: (a) tiny bundles appear; (b) these bundles aggregate into larger bundles; and (c) the filaments become maximally cross-linked by fascin. In mutants that completely lack forked, aggregation of the bundles does not occur so that the mature bundles consist of <50 filaments versus ∼700 for wild type. If the forked concentration is genetically reduced to half the wild type, aggregation of the tiny bundles occurs but the filaments are poorly ordered albeit with small patches of fascin cross-linked filaments. In mutants containing an excess of forked, all the bundles tend to aggregate and the filaments are maximally crossbridged by fascin. Alternatively, if fascin is absent, phases 1 and 2 occur normally but the resultant bundles are twisted and the filaments within them are poorly ordered. By extracting fully elongated bristles with potassium iodide which removes fascin but leaves forked, the bundles change from being straight to twisted and the filaments within them become poorly ordered. From these observations we conclude that (a) forked is used early in development to aggregate the tiny bundles into larger bundles; and (b) forked facilitates fascin entry into the bundles to maximally cross-link the actin filaments into straight, compact, rigid bundles. Thus, forked aligns the filaments and then directs fascin binding so that inappropriate cross-linking does not occur. PMID:9763425

  5. 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…

  6. The effect of Mg2+ on cardiac muscle function: Is CaATP the substrate for priming myofibril cross-bridge formation and Ca2+ reuptake by the sarcoplasmic reticulum?

    PubMed Central

    Smith, G A; Vandenberg, J I; Freestone, N S; Dixon, H B

    2001-01-01

    Kinetics are established for the activation of the myofibril from the relaxed state [Smith, Dixon, Kirschenlohr, Grace, Metcalfe and Vandenberg (2000) Biochem. J. 346, 393-402]. These require two troponin Ca2+-binding sites, one for each myosin head, to act as a single unit in initial cross-bridge formation. This defines the first, or activating, ATPase reaction, as distinct from the further activity of the enzyme that continues when a cross-bridge to actin is already established. The pairing of myosin heads to act as one unit suggests a possible alternating mechanism for muscle action. A large positive inotropic (contraction-intensifying) effect of loading the Mg2+ chelator citrate, via its acetoxymethyl ester, into the heart has confirmed the competitive inhibition of the Ca2+ activation by Mg2+, previously seen in vitro. In the absence of a recognized second Ca2+ binding site on the myofibril, with appropriate binding properties, the bound ATP is proposed as the second activating Ca2+-binding site. As ATP, free or bound to protein, can bind either Mg2+ or Ca2+, this leads to competitive inhibition by Mg2+. Published physico-chemical studies on skeletal muscle have shown that CaATP is potentially a more effective substrate than MgATP for cross-bridge formation. The above considerations allow calculation of the observed variation of fractional activation by Ca2+ as a function of [Mg2+] and in turn reveal simple Michaelis-Menten kinetics for the activation of the ATPase by sub-millimolar [Mg2+]. Furthermore the ability of bound ATP to bind either cation, and the much better promotion of cross-bridge formation by CaATP binding, give rise to the observed variation of the Hill coefficient for Ca2+ activation with altered [Mg2+]. The inclusion of CaADP within the initiating cross-bridge and replacement by MgADP during the second cycle is consistent with the observed fall in the rate of the myofibril ATPase that occurs after two phosphates are released. The similarity

  7. Bridges, 2002.

    ERIC Educational Resources Information Center

    Silver, Michael, Ed.; Zito, Michael, Ed.

    2002-01-01

    This document is comprised of the one issue in volume 7 of "Bridges," a publication produced by the California Head Start-State Collaboration Office to detail the activities of the educational partnership and to provide relevant information to programs participating in the partnership. The Summer 2002 issue focuses on several topics of…

  8. 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.

  9. Wheatstone's Bridge

    NASA Astrophysics Data System (ADS)

    Greenslade, Thomas B.

    2005-01-01

    The arrangement of four resistors, a source of emf, and a galvanometer, known as Wheatstone's bridge, has been in existence for more than 170 years. The only other piece of apparatus with its staying power is Atwood's machine. Now that it has reached mature status, it seems only fitting to describe its origin, analysis, circuit topology, and past and future uses.

  10. 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.

  11. 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)

  12. The DE and FG loops of the HPV major capsid protein contribute to the epitopes of vaccine-induced cross-neutralising antibodies

    PubMed Central

    Bissett, Sara L.; Godi, Anna; Beddows, Simon

    2016-01-01

    The human papillomavirus (HPV) vaccines consist of major capsid protein (L1) virus-like particles (VLP) and are highly efficacious against the development of cervical cancer precursors attributable to oncogenic genotypes, HPV16 and HPV18. A degree of vaccine-induced cross-protection has also been demonstrated against genetically-related genotypes in the Alpha-7 (HPV18-like) and Alpha-9 (HPV16-like) species groups which is coincident with the detection of L1 cross-neutralising antibodies. In this study the L1 domains recognised by inter-genotype cross-neutralising antibodies were delineated. L1 crystallographic homology models predicted a degree of structural diversity between the L1 loops of HPV16 and the non-vaccine Alpha-9 genotypes. These structural predictions informed the design of chimeric pseudovirions with inter-genotype loop swaps which demonstrated that the L1 domains recognised by inter-genotype cross-neutralising antibodies comprise residues within the DE loop and the late region of the FG loop. These data contribute to our understanding of the L1 domains recognised by vaccine-induced cross-neutralising antibodies. Such specificities may play a critical role in vaccine-induced cross-protection. PMID:28004837

  13. 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.

  14. 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. Therefo

  15. 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…

  16. 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,…

  17. Pulmonary vascular collagen content, not cross-linking, contributes to right ventricular pulsatile afterload and overload in early pulmonary hypertension.

    PubMed

    Wang, Zhijie; Schreier, David A; Abid, Hinnah; Hacker, Timothy A; Chesler, Naomi C

    2017-02-01

    Hypoxic pulmonary hypertension (HPH) is associated with pulmonary artery (PA) remodeling and right ventricular (RV) overload. We have previously uncovered collagen-mediated mechanisms of proximal PA stiffening in early HPH by manipulating collagen degradation and cross-linking using a transgenic mouse strain and a potent collagen cross-link inhibitor, β-aminopropionitrile (BAPN). However, the roles of collagen in distal PA remodeling, overall RV afterload, and RV hypertrophy in HPH remain unknown. Here, we used the same experimental strategy to investigate the effect of pulmonary vascular collagen content and cross-linking on steady and pulsatile RV afterload and on RV hypertrophy in early HPH. Collagenase-resistant mice (Col1a1(R/R)) and their littermate controls (Col1a1(+/+)) were exposed to normobaric hypoxia for 10 days with or without BAPN treatment. In vivo pulmonary vascular impedance, a comprehensive measure of RV afterload, was measured via simultaneous RV catheterization and echocardiography. Morphology and collagen accumulation were examined using histological techniques and ELISA in lungs and RVs. In both mouse strains, BAPN did not limit increases in pulmonary arterial pressure or pulmonary vascular resistance, indicating a negligible effect of either collagen content or cross-linking on steady RV afterload. However, BAPN prevented the increase in pulse pressure and RV hypertrophy in Col1a1(+/+) mice and these effects were absent in Col1a1(R/R) mice, suggesting a role for PA collagen content, not cross-linking, in the pulsatile RV afterload. Moreover, we found a significant correlation between pulse pressure and RV hypertrophy, indicating an important role for pulsatile RV afterload in RV overload in early HPH.

  18. Muscles that do not cross the knee contribute to the knee adduction moment and tibiofemoral compartment loading during gait.

    PubMed

    Sritharan, Prasanna; Lin, Yi-Chung; Pandy, Marcus G

    2012-10-01

    The aims of this study were to evaluate and explain the individual muscle contributions to the medial and lateral knee compartment forces during gait, and to determine whether these quantities could be inferred from their contributions to the external knee adduction moment. Gait data from eight healthy male subjects were used to compute each individual muscle contribution to the external knee adduction moment, the net tibiofemoral joint reaction force, and reaction moment. The individual muscle contributions to the medial and lateral compartment forces were then found using a least-squares approach. While knee-spanning muscles were the primary contributors, non-knee-spanning muscles (e.g., the gluteus medius) also contributed substantially to the medial compartment compressive force. Furthermore, knee-spanning muscles tended to compress both compartments, while most non-knee-spanning muscles tended to compress the medial compartment but unload the lateral compartment. Muscle contributions to the external knee adduction moment, particularly those from knee-spanning muscles, did not accurately reflect their tendencies to compress or unload the medial compartment. This finding may further explain why gait modifications may reduce the knee adduction moment without necessarily decreasing the medial compartment force.

  19. 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

  20. 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

  1. CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Evolutionary Self-Questioning Games with Local Contribution

    NASA Astrophysics Data System (ADS)

    Liu, Yong-Kui; Li, Zhi; Chen, Xiao-Jie; Wang, Long

    2009-08-01

    We investigate the evolutionary Prisoner's Dilemma and the Snowdrift Game on small-world networks in a realistic social context where individuals consider their local contributions to their group and update their strategies by self-questioning. An individual with introspection can determine whether its current strategy is superior by playing a virtual round of the game and its local contribution is defined as the sum of all the payoffs its neighbors collect against it. In our model, the performance of an individual is determined by both its payoff and local contribution through a linear combination. We demonstrate that the present mechanism can produce very robust cooperative behavior in both games. Furthermore, we provide theoretical analysis based on mean-field approximation, and find that the analytical predictions are qualitatively consistent with the simulation results.

  2. Bridging Policy Implementation Gaps in Nigerian Education System: A Case Study of Universal Basic Education Programme in Cross River State, Nigeria

    ERIC Educational Resources Information Center

    Ogbiji, Joseph Etiongbie; Ogbiji, Sylvanus Achua

    2016-01-01

    This research focuses on identifying policy gaps in the implementation of Universal Basic Education (UBE) programme in Nigeria, with Cross River State being the study area. The three research questions used for the research center on the extent of the freeness of the UBE, the extent to which the programme has stimulated educational consciousness…

  3. 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

  4. Less is more: Nutrient limitation induces cross-talk of nutrient sensing pathways with NAD+ homeostasis and contributes to longevity

    PubMed Central

    TSANG, Felicia; LIN, Su-Ju

    2016-01-01

    Nutrient sensing pathways and their regulation grant cells control over their metabolism and growth in response to changing nutrients. Factors that regulate nutrient sensing can also modulate longevity. Reduced activity of nutrient sensing pathways such as glucose-sensing PKA, nitrogen-sensing TOR and S6 kinase homolog Sch9 have been linked to increased life span in the yeast, Saccharomyces cerevisiae, and higher eukaryotes. Recently, reduced activity of amino acid sensing SPS pathway was also shown to increase yeast life span. Life span extension by reduced SPS activity requires enhanced NAD+ (nicotinamide adenine dinucleotide, oxidized form) and nicotinamide riboside (NR, a NAD+ precursor) homeostasis. Maintaining adequate NAD+ pools has been shown to play key roles in life span extension, but factors regulating NAD+ metabolism and homeostasis are not completely understood. Recently, NAD+ metabolism was also linked to the phosphate (Pi)-sensing PHO pathway in yeast. Canonical PHO activation requires Pi-starvation. Interestingly, NAD+ depletion without Pi-starvation was sufficient to induce PHO activation, increasing NR production and mobilization. Moreover, SPS signaling appears to function in parallel with PHO signaling components to regulate NR/NAD+ homeostasis. These studies suggest that NAD+ metabolism is likely controlled by and/or coordinated with multiple nutrient sensing pathways. Indeed, cross-regulation of PHO, PKA, TOR and Sch9 pathways was reported to potentially affect NAD+ metabolism; though detailed mechanisms remain unclear. This review discusses yeast longevity-related nutrient sensing pathways and possible mechanisms of life span extension, regulation of NAD+ homeostasis, and cross-talk among nutrient sensing pathways and NAD+ homeostasis. PMID:27683589

  5. 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

  6. Salt bridges: geometrically specific, designable interactions.

    PubMed

    Donald, Jason E; Kulp, Daniel W; DeGrado, William F

    2011-03-01

    Salt bridges occur frequently in proteins, providing conformational specificity and contributing to molecular recognition and catalysis. We present a comprehensive analysis of these interactions in protein structures by surveying a large database of protein structures. Salt bridges between Asp or Glu and His, Arg, or Lys display extremely well-defined geometric preferences. Several previously observed preferences are confirmed, and others that were previously unrecognized are discovered. Salt bridges are explored for their preferences for different separations in sequence and in space, geometric preferences within proteins and at protein-protein interfaces, co-operativity in networked salt bridges, inclusion within metal-binding sites, preference for acidic electrons, apparent conformational side chain entropy reduction on formation, and degree of burial. Salt bridges occur far more frequently between residues at close than distant sequence separations, but, at close distances, there remain strong preferences for salt bridges at specific separations. Specific types of complex salt bridges, involving three or more members, are also discovered. As we observe a strong relationship between the propensity to form a salt bridge and the placement of salt-bridging residues in protein sequences, we discuss the role that salt bridges might play in kinetically influencing protein folding and thermodynamically stabilizing the native conformation. We also develop a quantitative method to select appropriate crystal structure resolution and B-factor cutoffs. Detailed knowledge of these geometric and sequence dependences should aid de novo design and prediction algorithms.

  7. 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

  8. 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

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

    PubMed

    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.

  10. Food items contributing most to variation in antioxidant intake; a cross-sectional study among Norwegian women

    PubMed Central

    2014-01-01

    Background Fruit and vegetable intake has been found to reduce the risk of cardiovascular disease, certain types of cancer and diabetes mellitus. It is possible that antioxidants play a large part in this protective effect. However, which foods account for the variation in antioxidant intake in a population is not very clear. We used food frequency data from a population-based sample of women to identify the food items that contributed most to the variation in antioxidant intake in Norwegian diet. Methods We used data from a study conducted among participants in the Norwegian Breast Cancer Screening Program (NBCSP), the national program which invites women aged 50–69 years to mammographic screening every 2 years. A subset of 6514 women who attended the screening in 2006/2007 completed a food frequency questionnaire (FFQ). Daily intake of energy, nutrients and antioxidant intake were estimated. We used multiple linear regression analysis to capture the variation in antioxidant intake. Results The mean (SD) antioxidant intake was 23.0 (8.5) mmol/day. Coffee consumption explained 54% of the variation in antioxidant intake, while fruits and vegetables explained 22%. The twenty food items that contributed most to the total variation in antioxidant intake explained 98% of the variation in intake. These included different types of coffee, tea, red wine, blueberries, walnuts, oranges, cinnamon and broccoli. Conclusions In this study we identified a list of food items which capture the variation in antioxidant intake among these women. The major contributors to dietary total antioxidant intake were coffee, tea, red wine, blueberries, walnuts, oranges, cinnamon and broccoli. These items should be assessed in as much detail as possible in studies that wish to capture the variation in antioxidant intake. PMID:24433390

  11. Factors contributing to the collision cross section of polyatomic ions in the kilodalton to gigadalton range: application to ion mobility measurements.

    PubMed

    Wyttenbach, Thomas; Bleiholder, Christian; Bowers, Michael T

    2013-02-19

    The projected superposition approximation (PSA) method was used to theoretically evaluate the factors contributing to the cross section measured in ion mobility experiments and to study how the significance of these factors varies with ion size from diglycine to a 1 μm oil droplet. Thousands of PSA calculations for ∼400 different molecules in the temperature range from 80 to 700 K revealed that the molecular framework made up of atomic hard spheres is, as expected, a major component of the cross section. However, the ion-buffer gas interaction is almost equally important for very small peptides, and although its significance decreases with increasing ion size, interaction is still a factor for megadalton ions. An additional major factor is the ion shape: Fully convex ions drifting in a buffer gas have a minimal frictional resisting force, whereas the resisting force increases with degree of ion surface concaveness. This added resistance is small for peptides and larger for proteins and increases the ion mobility cross section from 0 to greater than 40%. The proteins with the highest degree of concaveness reach a shape-effected friction similar to, and sometimes larger than that of, macroscopic particles such as oil droplets. In summary, our results suggest that the transition from nanoparticle (with Lennard-Jones-like interaction with the buffer gas) to macroscopic particle (with hard sphere-like interaction) occurs at ∼1 GDa.

  12. 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

  13. The cross-cutting contribution of the end of neglected tropical diseases to the sustainable development goals.

    PubMed

    Bangert, Mathieu; Molyneux, David H; Lindsay, Steve W; Fitzpatrick, Christopher; Engels, Dirk

    2017-04-04

    The Sustainable Development Goals (SDGs) call for an integrated response, the kind that has defined Neglected Tropical Diseases (NTDs) efforts in the past decade.NTD interventions have the greatest relevance for SDG3, the health goal, where the focus on equity, and its commitment to reaching people in need of health services, wherever they may live and whatever their circumstances, is fundamentally aligned with the target of Universal Health Coverage. NTD interventions, however, also affect and are affected by many of the other development areas covered under the 2030 Agenda. Strategies such as mass drug administration or the programmatic integration of NTD and WASH activities (SDG6) are driven by effective global partnerships (SDG17). Intervention against the NTDs can also have an impact on poverty (SDG1) and hunger (SDG2), can improve education (SDG4), work and economic growth (SDG8), thereby reducing inequalities (SDG10). The community-led distribution of donated medicines to more than 1 billion people reinforces women's empowerment (SDG5), logistics infrastructure (SDG9) and non-discrimination against disability (SDG16). Interventions to curb mosquito-borne NTDs contribute to the goals of urban sustainability (SDG11) and resilience to climate change (SDG13), while the safe use of insecticides supports the goal of sustainable ecosystems (SDG15). Although indirectly, interventions to control water- and animal-related NTDs can facilitate the goals of small-scale fishing (SDG14) and sustainable hydroelectricity and biofuels (SDG7).NTDs proliferate in less developed areas in countries across the income spectrum, areas where large numbers of people have little or no access to adequate health care, clean water, sanitation, housing, education, transport and information. This scoping review assesses how in this context, ending the epidemic of the NTDs can impact and improve our prospects of attaining the SDGs.

  14. The natural cytotoxicity receptor 1 contribution to early clearance of Streptococcus pneumoniae and to natural killer-macrophage cross talk.

    PubMed

    Elhaik-Goldman, Shirin; Kafka, Daniel; 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-ligand(high) lung macrophages, in NCR1-expressing mice, that had better phagocytic activity compared to NCR1-ligand(dull) 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.

  15. 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.

  16. 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 wa