Science.gov

Sample records for 65 mph speed limit

  1. 70-mph speed limit and motor vehicular fatalities on interstate highways.

    PubMed

    Bartle, Samuel T; Baldwin, Steven T; Johnston, Carden; King, William

    2003-09-01

    In May 1996, Alabama increased the rural interstate highways speed limit to 70 mph. This study was conducted to determine if the faster speed limit had any influence on the number of motor vehicular crash (MVC) deaths. The null hypothesis was that no significant change occurred in the number of deaths since the faster speed was introduced. Using MVC fatality data collected by the Alabama Department of Public Safety and published by the state of Alabama from 1984 to 1999, a time-series study designed was used to examine the number of MVC deaths before and after the speed limit change. The trend of MVC deaths was examined for both rural and urban interstate highways and those occurring on Federal and state highways. There were 174 interstate MVC deaths in 1997 and 165 in 1999; both figures represent a significant increase (P <.05) from the trend of previous years' results. State and Federal highways demonstrated no significant change. By 1998 the number of interstate highway MVC deaths dropped to 114, falling back within the expected trend established by the results of the previous years. The number of rural interstate MVC deaths was found to be significant in 1997 and 1999. The faster speed limit was associated with an increase in MVC deaths for the first year after the speed limit increase. The decline in the number of MVC deaths for 1998 was unanticipated. There are many other factors that need to be evaluated before determining the cause and effect that higher speed limits have on MVC fatalities.

  2. Using Mandated Speed Limits to Measure the Value of a Statistical Life

    ERIC Educational Resources Information Center

    Ashenfelter, Orley; Greenstone, Michael

    2004-01-01

    In 1987 the federal government permitted states to raise the speed limit on their rural interstate roads, but not on their urban interstate roads, from 55 mph to 65 mph. Since the states that adopted the higher speed limit must have valued the travel hours they saved more than the fatalities incurred, this institutional change provides an…

  3. Driver speed selection on high-speed two-lane highways: Comparing speed profiles between uniform and differential speed limits.

    PubMed

    Russo, Brendan J; Savolainen, Peter T; Gates, Timothy J; Kay, Jonathan J; Frazier, Sterling

    2017-07-04

    Although a considerable amount of prior research has investigated the impacts of speed limits on traffic safety and operations, much of this research, and nearly all of the research related to differential speed limits, has been specific to limited access freeways. The unique safety and operational issues on highways without access control create difficulty relating the conclusions from prior freeway-related speed limit research to 2-lane highways, particularly research on differential limits due to passing limitations and subsequent queuing. Therefore, the objective of this study was to assess differences in driver speed selection with respect to the posted speed limit on rural 2-lane highways, with a particular emphasis on the differences between uniform and differential speed limits. Data were collected from nearly 59,000 vehicles across 320 sites in Montana and 4 neighboring states. Differences in mean speeds, 85th percentile speeds, and the standard deviation in speeds for free-flowing vehicles were examined across these sites using ordinary least squares regression models. Ultimately, the results of the analysis show that the mean speed, 85th percentile speed, and variability in travel speeds for free-flowing vehicles on 2-lane highways are generally lower at locations with uniform 65 mph speed limits, compared to locations with differential limits of 70 mph for cars and 60 mph for trucks. In addition to posted speed limits, several site characteristics were shown to influence speed selection including shoulder widths, frequency of horizontal curves, percentage of the segment that included no passing zones, and hourly volumes. Differences in vehicle speed characteristics were also observed between states, indicating that speed selection may also be influenced by local factors, such as driver population or enforcement.

  4. Effect of repeal of the national maximum speed limit law on occurrence of crashes, injury crashes, and fatal crashes on Utah highways.

    PubMed

    Vernon, Donald D; Cook, Lawrence J; Peterson, Katharine J; Michael Dean, J

    2004-03-01

    Speed limits were increased in Utah and other States after repeal of the national maximum speed limit law (NMSL) in 1995. This study analyzed effects of the increased speed limit on Utah highways on crash rates, fatality crash rates, and injury crash rates. Annual (1992-1999) rates of crashes, fatality crashes, and injury crashes for the following highway categories were calculated: urban Interstate segments (current speed limit 60-65 miles per hour (mph)); rural Interstate segments (current speed limit 70-75 mph); 55 mph rural non-Interstate highway segments; and high-speed non-Interstate highways (current speed limit 60-65 mph). Data were analyzed using autoregressive integrative moving average intervention time series analysis techniques. There were significant increases in total crash rates on urban (60-65 mph) Interstate segments (confounded by extensive ongoing highway construction on these highways), and in fatal crash rates on high-speed (60-65 mph) rural non-Interstate segments. The following variables were unaffected: total, fatality, and injury crash rates on rural Interstate segments; fatality and injury crash rates on urban Interstate segments; total and injury crash rates on high-speed non-Interstate segments. These results show an adverse effect on crash occurrence for subsets of crash types and highways, but do not show a major overall effect of NMSL repeal and increased speed limit on crash occurrence on Utah highways.

  5. North American X-15 model tested in 300MPH Low Speed 7x10 Tunnel

    NASA Image and Video Library

    1958-09-07

    A one-twentieth scale model of the X-15 originally suspended beneath the wing of a B-52 is observed by a scientist of the National Aeronautics and Space Administration (NASA) as it leaves the bomber model in tests to determine the release characteristics and drop motion of the research airplane. Caption: The aerodynamics of air launching the North American X-15 being investigated in the 300MPH Low Speed 7x10 Tunnel, about 1957. Photograph published in Engineer in Charge: A History of the Langley Aeronautical Laboratory, 1917-1958 by James R. Hansen. Page 366. Photograph also published in Sixty Years of Aeronautical Research 1917-1977 By David A. Anderton. A NASA publication. Page 49.

  6. Effect of 20 mph traffic speed zones on road injuries in London, 1986-2006: controlled interrupted time series analysis.

    PubMed

    Grundy, Chris; Steinbach, Rebecca; Edwards, Phil; Green, Judith; Armstrong, Ben; Wilkinson, Paul

    2009-12-10

    To quantify the effect of the introduction of 20 mph (32 km an hour) traffic speed zones on road collisions, injuries, and fatalities in London. Observational study based on analysis of geographically coded police data on road casualties, 1986-2006. Analyses were made of longitudinal changes in counts of road injuries within each of 119 029 road segments with at least one casualty with conditional fixed effects Poisson models. Estimates of the effect of introducing 20 mph zones on casualties within those zones and in adjacent areas were adjusted for the underlying downward trend in traffic casualties. London. All casualties from road collisions; those killed and seriously injured (KSI). The introduction of 20 mph zones was associated with a 41.9% (95% confidence interval 36.0% to 47.8%) reduction in road casualties, after adjustment for underlying time trends. The percentage reduction was greatest in younger children and greater for the category of killed or seriously injured casualties than for minor injuries. There was no evidence of casualty migration to areas adjacent to 20 mph zones, where casualties also fell slightly by an average of 8.0% (4.4% to 11.5%). Conclusions 20 mph zones are effective measures for reducing road injuries and deaths.

  7. Speed limits of aircraft

    NASA Technical Reports Server (NTRS)

    Everling, E

    1923-01-01

    This paper is restricted to the question of attainable speed limits and attacks the problem from different angles. Theoretical limits due to air resistance are presented along with design factors which may affect speed such as wing loads, wing areas, wing section shifting, landing speeds, drag-lift ratios, and power coefficients.

  8. Speed kills? Not always: the New York State thruway experience.

    PubMed

    Jehle, Dietrich von Kuenssberg; Connolly, Sara; Godzala, Michael; Cole, Adam

    2010-09-01

    The New York State (NYS) speed limit increased from 55 mph to 65 mph in August 1995. This study examines the change in motor vehicle fatality rates on the NYS thruway and NYS Interstates before and after the speed limit change. We also compare the fatality rates pre- and postincreased speed limit between the NYS thruway and other major NYS roadways, where speed limit remained unchanged at 55 mph. The number of fatalities and vehicle miles traveled (VMT) on individual roadways were extracted from NYS Department of Transportation reports. The data were divided into groups by prespeed limit change, August 1992 to August 1995, and postspeed limit change, August 1995 to August 1998, and roads where the speed limit remained unchanged at 55 mph. Data were also analyzed to assess the effect of variability of speed and general topography on changes in fatality rates on roads where the speed limit was increased. There was a 28.3% decrease in absolute mortality and a 42.6% decrease in mortality adjusted for VMT, on the NYS thruway after the speed limit increase from 55 mph to 65 mph. When compared with roadways, where the speed limit remained unchanged, there was a 52.4% reduction in fatality rates below the predicted rates after the speed limit increase (p = 0.009). On the NYS interstate system, there was a 13.5% decrease in absolute mortality and a 29.2% decrease in mortality adjusted for VMT, after the speed limit increase. The percentage of traffic traveling >10 mph faster than the speed limit dropped from 39% to 8% on roads, where the speed limit was increased from 55 mph to 65 mph. In the NYS interstate system, "flat" roads (elevation <200 m) had a 30.2% reduction in absolute mortality, whereas "mountainous" roads (elevations >200 m) had a 17.6% increase in absolute mortality in response to the speed limit increase (p < 0.001). Motor vehicle speed is a key determinate of the severity of injury in an individual crash; however, speed variance and road topography have also

  9. Feasibility of Rough Terrain Forklift Trucks with a Road Speed Capability of 45 mph.

    DTIC Science & Technology

    1986-05-01

    PURPOSE MATERIAL HANDLER ACCESSORIES DRIVE-LINE SPECIFICATIONS: (ADD-ONS TO THE BASIC UNIT) ENGINE CAB ENCLOSURE Make and Model ....... PerkinsT4.236 All...Suspension System 8-Wheel Independent Fuel Tank Capacity 50 Gals Traing Arm Drive Hydraulic Tank Capacity 25 Gals Steering Pivot T Automotive Type...current specification for headlamps conforms to the relevant SAE standards but these should be reviewed for adequacy at highway speeds. Rearview

  10. 14 CFR 23.33 - Propeller speed and pitch limits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller speed and pitch limits. 23.33... Propeller speed and pitch limits. (a) General. The propeller speed and pitch must be limited to values that... the all engine(s) operating climb speed specified in § 23.65, the propeller must limit the engine r.p...

  11. 14 CFR 23.33 - Propeller speed and pitch limits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller speed and pitch limits. 23.33... Propeller speed and pitch limits. (a) General. The propeller speed and pitch must be limited to values that... the all engine(s) operating climb speed specified in § 23.65, the propeller must limit the engine r.p...

  12. 49 CFR 213.307 - Class of track: operating speed limits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... operating speed for trains 1 is— Class 6 track 110 m.p.h. Class 7 track 125 m.p.h. Class 8 track 160 m.p.h. 2 Class 9 track 200 m.p.h. 1 Freight may be transported at passenger train speeds if the following... 150 m.p.h. are authorized by this part only in conjunction with a rule of particular...

  13. 49 CFR 213.307 - Class of track: operating speed limits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... operating speed for trains 1 is— Class 6 track 110 m.p.h. Class 7 track 125 m.p.h. Class 8 track 160 m.p.h. 2 Class 9 track 200 m.p.h. 1 Freight may be transported at passenger train speeds if the following... 150 m.p.h. are authorized by this part only in conjunction with a rule of particular...

  14. 49 CFR 213.307 - Class of track: operating speed limits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... operating speed for trains 1 is— Class 6 track 110 m.p.h. Class 7 track 125 m.p.h. Class 8 track 160 m.p.h. 2 Class 9 track 200 m.p.h. 1 Freight may be transported at passenger train speeds if the following... 150 m.p.h. are authorized by this part only in conjunction with a rule of particular applicability...

  15. The Optimum Speed Limit.

    DTIC Science & Technology

    1981-05-01

    time eases the interpretation: U2 Lx -4-- where VT is the value of time (dollars (1975) per hour) V is the value of a life (dollars (1975) per L person...that for an individual, the optimal speed depends positively on his value of time and negatively on his valuation of his own life, his subjective...turn to equation (1) once again and solve for the ratio of the value of a life to the value of time , or 1 P s 2 GaS VL SP VT VT az as Rearranging

  16. 14 CFR 142.65 - Limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... used during line operational simulation for evaluation and line-oriented flight training only to... OTHER CERTIFICATED AGENCIES TRAINING CENTERS Operating Rules § 142.65 Limitations. (a) A certificate holder shall— (1) Ensure that a flight simulator or flight training device freeze, slow motion,...

  17. 14 CFR 142.65 - Limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... used during line operational simulation for evaluation and line-oriented flight training only to... OTHER CERTIFICATED AGENCIES TRAINING CENTERS Operating Rules § 142.65 Limitations. (a) A certificate holder shall— (1) Ensure that a flight simulator or flight training device freeze, slow motion,...

  18. Evaluation of variable speed limits for real-time freeway safety improvement.

    PubMed

    Abdel-Aty, Mohamed; Dilmore, Jeremy; Dhindsa, Albinder

    2006-03-01

    Use of various variable speed limit (VSL) strategies as a tool for safety improvement on freeways was evaluated using simulation of a section of Interstate 4 in Orlando, FL. Real-time crash likelihood was calculated based on models developed in previous research by the first author [Abdel-Aty, M., Uddin, N., Pande, A., January 2005. Split models for predicting multi-vehicle crashes during high-speed and low-speed operating conditions on freeways. In: Presented at the 84th Annual Meeting of the Transportation Research Board, Washington, DC]. VSL implementation produced safety improvement by simultaneously implementing lower speed limits upstream and higher speed limits downstream of the location where crash likelihood is observed in real-time. This improvement was realized in the case of medium-to-high-speed regimes on the freeway, but no benefit was achieved in low-speed situations (no substantial safety benefit from implementing VSL in congested situation's simulation). The final recommendations for implementing VSL are: gradually introducing speed limit changes over time (5 mph every 10 min); abruptly changing speed limit in space ( no gap distance); reducing speed limits upstream and increasing speed limits downstream of location of interest; the speed limit changes up- and downstream should be large in magnitude (15 mph) and implemented within short distances (2 miles) of the location of interest. In addition to the safety benefit, this final strategy also produced travel time savings.

  19. Generalized Geometric Quantum Speed Limits

    NASA Astrophysics Data System (ADS)

    Pires, Diego Paiva; Cianciaruso, Marco; Céleri, Lucas C.; Adesso, Gerardo; Soares-Pinto, Diogo O.

    2016-04-01

    The attempt to gain a theoretical understanding of the concept of time in quantum mechanics has triggered significant progress towards the search for faster and more efficient quantum technologies. One of such advances consists in the interpretation of the time-energy uncertainty relations as lower bounds for the minimal evolution time between two distinguishable states of a quantum system, also known as quantum speed limits. We investigate how the nonuniqueness of a bona fide measure of distinguishability defined on the quantum-state space affects the quantum speed limits and can be exploited in order to derive improved bounds. Specifically, we establish an infinite family of quantum speed limits valid for unitary and nonunitary evolutions, based on an elegant information geometric formalism. Our work unifies and generalizes existing results on quantum speed limits and provides instances of novel bounds that are tighter than any established one based on the conventional quantum Fisher information. We illustrate our findings with relevant examples, demonstrating the importance of choosing different information metrics for open system dynamics, as well as clarifying the roles of classical populations versus quantum coherences, in the determination and saturation of the speed limits. Our results can find applications in the optimization and control of quantum technologies such as quantum computation and metrology, and might provide new insights in fundamental investigations of quantum thermodynamics.

  20. 36 CFR 4.21 - Speed limits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Speed limits. 4.21 Section 4... TRAFFIC SAFETY § 4.21 Speed limits. (a) Park area speed limits are as follows: (1) 15 miles per hour... superintendent may designate a different speed limit upon any park road when a speed limit set forth in paragraph...

  1. 36 CFR 4.21 - Speed limits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Speed limits. 4.21 Section 4... TRAFFIC SAFETY § 4.21 Speed limits. (a) Park area speed limits are as follows: (1) 15 miles per hour... superintendent may designate a different speed limit upon any park road when a speed limit set forth in paragraph...

  2. 49 CFR 213.307 - Classes of track: operating speed limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... allowableoperating speed for trains is 1 Class 6 track 110 m.p.h. Class 7 track 125 m.p.h. Class 8 track 160 m.p.h.2 Class 9 track 220 m.p.h.2 1 Freight may be transported at passenger train speeds if the following....p.h. are authorized by this part only in conjunction with FRA regulatory approval addressing other...

  3. 49 CFR 213.307 - Classes of track: operating speed limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... allowableoperating speed for trains is 1 Class 6 track 110 m.p.h. Class 7 track 125 m.p.h. Class 8 track 160 m.p.h.2 Class 9 track 220 m.p.h.2 1 Freight may be transported at passenger train speeds if the following....p.h. are authorized by this part only in conjunction with FRA regulatory approval addressing other...

  4. 45 CFR 3.26 - Speed limit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare... INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles per hour, unless otherwise posted. A driver of a vehicle may not exceed the speed limit. ...

  5. 45 CFR 3.26 - Speed limit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare... INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles per hour, unless otherwise posted. A driver of a vehicle may not exceed the speed limit. ...

  6. A speed limit for evolution.

    PubMed

    Worden, R P

    1995-09-07

    An upper bound on the speed of evolution is derived. The bound concerns the amount of genetic information which is expressed in observable ways in various aspects of the phenotype. The genetic information expressed in some part of the phenotype of a species cannot increase faster than a given rate, determined by the selection pressure on that part. This rate is typically a small fraction of a bit per generation. Total expressed genetic information cannot increase faster than a species-specific rate--typically a few bits per generation. These bounds apply to all aspects of the phenotype, but are particularly relevant to cognition. As brains are highly complex, we expect large amounts of expressed genetic information in the brain--of the order of 100 kilobytes--yet evolutionary changes in brain genetic information are only a fraction of a bit per generation. This has important consequences for cognitive evolution. The limit implies that the human brain differs from the chimpanzee brain by at most 5 kilobytes of genetic design information. This is not enough to define a Language Acquisition Device, unless it depends heavily on pre-existing primate symbolic cognition. Subject to the evolutionary speed limit, in changing environments a simple, modular brain architecture is fitter than more complex ones. This encourages us to look for simplicity in brain design, rather than expecting the brain to be a patchwork of ad hoc adaptations. The limit implies that pure species selection is not an important mechanism of evolutionary change.

  7. Is There a Speed Limit?

    NASA Technical Reports Server (NTRS)

    Chalmers, B.

    1984-01-01

    Fundamental barriers limiting the rate of the growth of crystals suitable for processing into cost efficient effective solar cells are discussed. The physical conditions which permit the growth of sheet directly from the melt are explored to identify the factors which control the growth rate. These criteria are edge defined film fed growth, free meniscus growth and inclined interface growth with specific reference to the effects that increase of speed has on those aspects of the resulting material that bear on the quality of the solar cells made from it. Useful directions for future research are indicated.

  8. Electroweak bubble wall speed limit

    NASA Astrophysics Data System (ADS)

    Bödeker, Dietrich; Moore, Guy D.

    2017-05-01

    In extensions of the Standard Model with extra scalars, the electroweak phase transition can be very strong, and the bubble walls can be highly relativistic. We revisit our previous argument that electroweak bubble walls can "run away," that is, achieve extreme ultrarelativistic velocities γ ~ 1014. We show that, when particles cross the bubble wall, they can emit transition radiation. Wall-frame soft processes, though suppressed by a power of the coupling α, have a significance enhanced by the γ-factor of the wall, limiting wall velocities to γ ~ 1/α. Though the bubble walls can move at almost the speed of light, they carry an infinitesimal share of the plasma's energy.

  9. 14 CFR 23.33 - Propeller speed and pitch limits.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... For each propeller whose pitch cannot be controlled in flight— (1) During takeoff and initial climb at the all engine(s) operating climb speed specified in § 23.65, the propeller must limit the engine...

  10. 14 CFR 23.33 - Propeller speed and pitch limits.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... For each propeller whose pitch cannot be controlled in flight— (1) During takeoff and initial climb at the all engine(s) operating climb speed specified in § 23.65, the propeller must limit the engine...

  11. 36 CFR 1004.21 - Speed limits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Speed limits. 1004.21 Section... limits. (a) Speed limits in the area administered by the Presidio Trust are as follows: (1) 15 miles per... Presidio Trust roads. (b) The Board may designate a different speed limit upon any Presidio Trust road when...

  12. 36 CFR 1004.21 - Speed limits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Speed limits. 1004.21 Section... limits. (a) Speed limits in the area administered by the Presidio Trust are as follows: (1) 15 miles per... Presidio Trust roads. (b) The Board may designate a different speed limit upon any Presidio Trust road when...

  13. 45 CFR 3.26 - Speed limit.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CONDUCT OF PERSONS AND TRAFFIC ON THE NATIONAL INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles...

  14. 45 CFR 3.26 - Speed limit.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CONDUCT OF PERSONS AND TRAFFIC ON THE NATIONAL INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles...

  15. 45 CFR 3.26 - Speed limit.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare Department of Health and Human Services GENERAL ADMINISTRATION CONDUCT OF PERSONS AND TRAFFIC ON THE NATIONAL INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles...

  16. 50 CFR 38.13 - Speed limits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Speed limits. 38.13 Section 38.13 Wildlife... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Prohibitions § 38.13 Speed limits. No person on Midway Atoll National Wildlife Refuge will exceed the speed limit for automobiles, trucks...

  17. 50 CFR 38.13 - Speed limits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Speed limits. 38.13 Section 38.13 Wildlife... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Prohibitions § 38.13 Speed limits. No person on Midway Atoll National Wildlife Refuge will exceed the speed limit for automobiles, trucks...

  18. 32 CFR 935.132 - Speed limits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Speed limits. 935.132 Section 935.132 National... WAKE ISLAND CODE Motor Vehicle Code § 935.132 Speed limits. Each person operating a motor vehicle on..., or both; and (b) That does not exceed 40 miles an hour or such lesser speed limit as may be posted. ...

  19. 32 CFR 935.132 - Speed limits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Speed limits. 935.132 Section 935.132 National... WAKE ISLAND CODE Motor Vehicle Code § 935.132 Speed limits. Each person operating a motor vehicle on..., or both; and (b) That does not exceed 40 miles an hour or such lesser speed limit as may be posted. ...

  20. Systematic two-dimensional cascade tests of NACA 65-series compressor blades at low speeds

    NASA Technical Reports Server (NTRS)

    Herrig, L Joseph; Emery, James C; Erwin, John R

    1957-01-01

    A two-dimensional low-speed porous-wall cascade tunnel investigation has been conducted to establish the performance of the NACA 65-series compressor blade sections over the useful range of inlet angle, solidity, and section camber. Design points for optimum high-speed operation are presented. The loading limitation is determined for some conditions. Trends of section operating range with increasing section camber are determined for the four inlet angles tested.

  1. 36 CFR 4.21 - Speed limits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of park road under repair or construction. (3) 45 miles per hour: upon all other park roads. (b) The superintendent may designate a different speed limit upon any park road when a speed limit set forth in paragraph... person may utilize radiomicrowaves or other electrical devices to determine the speed of a vehicle on a...

  2. 36 CFR 4.21 - Speed limits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of park road under repair or construction. (3) 45 miles per hour: upon all other park roads. (b) The superintendent may designate a different speed limit upon any park road when a speed limit set forth in paragraph... person may utilize radiomicrowaves or other electrical devices to determine the speed of a vehicle on a...

  3. 36 CFR 4.21 - Speed limits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of park road under repair or construction. (3) 45 miles per hour: upon all other park roads. (b) The superintendent may designate a different speed limit upon any park road when a speed limit set forth in paragraph... person may utilize radiomicrowaves or other electrical devices to determine the speed of a vehicle on a...

  4. 33 CFR 401.28 - Speed limits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Speed limits. 401.28 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.28 Speed limits. (a) The maximum speed over the bottom for a vessel of more than 12 m in overall length shall be regulated so as not to...

  5. 33 CFR 401.28 - Speed limits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Speed limits. 401.28 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.28 Speed limits. (a) The maximum speed over the bottom for a vessel of more than 12 m in overall length shall be regulated so as not to...

  6. 33 CFR 401.28 - Speed limits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Speed limits. 401.28 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.28 Speed limits. (a) The maximum speed over the bottom for a vessel of more than 12 m in overall length shall be regulated so as not to...

  7. The Optimum Speed Limit. Revised.

    DTIC Science & Technology

    1983-07-01

    Relating U, and U to the values of life and time eases the interpretation: (2) U, -vX; (2a) U, -V. XI where: V, is the dollar value of time (more precisely...by (3) I V [ as ;as Equation (3) shows that for an individual, the optimal speed depends positively on his value of time and negatively on his...fatality rates to driving speed and gas mileage to speed. The value of time and the value of a life are harder to determine because they cannot be

  8. Speed limits, enforcement, and health consequences.

    PubMed

    Elvik, Rune

    2012-04-01

    This review summarizes current knowledge regarding the effects of speed limit enforcement on public health. Speed limits are commonly used around the world to regulate the maximum speed at which motor vehicles can be operated on public roads. Speed limits are statutory, and violations of them are normally sanctioned by means of fixed penalties (traffic tickets) or, in the event of serious violations, suspension of the driver's license and imposition of prison sentences. Speed limit violations are widespread in all countries for which statistics can be found. Speeding contributes more to the risk of traffic injury than do other risk factors for which estimates of population-attributable risk are available. Traffic speed strongly influences impact speed in crashes and therefore has major implications for public health.

  9. 28 CFR 345.65 - Inmate medical work limitation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Inmate medical work limitation. 345.65... PRISON INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.65 Inmate medical work limitation. In addition to any prior illnesses or injuries, medical limitations also include any illness or...

  10. 36 CFR 1004.21 - Speed limits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 1004.21 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.21 Speed... traffic control devices. (c) Operating a vehicle at a speed in excess of the speed limit is prohibited. (d) An authorized person may utilize radiomicrowaves or other electrical devices to determine the...

  11. 28 CFR 345.65 - Inmate medical work limitation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Inmate medical work limitation. 345.65 Section 345.65 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE FEDERAL PRISON INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.65 Inmate medical...

  12. 40 CFR 65.46 - Alternative means of emission limitation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Alternative means of emission limitation. 65.46 Section 65.46 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Storage Vessels § 65.46 Alternative means of...

  13. 28 CFR 345.65 - Inmate medical work limitation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Inmate medical work limitation. 345.65 Section 345.65 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE FEDERAL PRISON INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.65 Inmate medical work...

  14. 28 CFR 345.65 - Inmate medical work limitation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Inmate medical work limitation. 345.65 Section 345.65 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE FEDERAL PRISON INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.65 Inmate medical work...

  15. 33 CFR 401.28 - Speed limits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Speed limits. 401.28 Section 401.28 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.28 Speed limits. (a) The...

  16. 50 CFR 38.13 - Speed limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Prohibitions § 38.13 Speed limits. No person on Midway Atoll National Wildlife Refuge will exceed the speed limit for automobiles, trucks... Atoll National Wildlife Refuge is 15 miles per hour....

  17. 50 CFR 38.13 - Speed limits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Prohibitions § 38.13 Speed limits. No person on Midway Atoll National Wildlife Refuge will exceed the speed limit for automobiles, trucks... Atoll National Wildlife Refuge is 15 miles per hour....

  18. 50 CFR 38.13 - Speed limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Prohibitions § 38.13 Speed limits. No person on Midway Atoll National Wildlife Refuge will exceed the speed limit for automobiles, trucks... Atoll National Wildlife Refuge is 15 miles per hour....

  19. 32 CFR 935.132 - Speed limits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Speed limits. 935.132 Section 935.132 National... WAKE ISLAND CODE Motor Vehicle Code § 935.132 Speed limits. Each person operating a motor vehicle on Wake Island shall operate it at a speed— (a) That is reasonable, safe, and proper, considering time of...

  20. 32 CFR 935.132 - Speed limits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Speed limits. 935.132 Section 935.132 National... WAKE ISLAND CODE Motor Vehicle Code § 935.132 Speed limits. Each person operating a motor vehicle on Wake Island shall operate it at a speed— (a) That is reasonable, safe, and proper, considering time of...

  1. 32 CFR 935.132 - Speed limits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Speed limits. 935.132 Section 935.132 National... WAKE ISLAND CODE Motor Vehicle Code § 935.132 Speed limits. Each person operating a motor vehicle on Wake Island shall operate it at a speed— (a) That is reasonable, safe, and proper, considering time of...

  2. 33 CFR 401.28 - Speed limits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Speed limits. 401.28 Section 401.28 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.28 Speed limits. (a) The maximum...

  3. 40 CFR 65.102 - Alternative means of emission limitation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... means of emission limitation. (ii) The Administrator will compare test data for the means of emission limitation to test data for the equipment, design, and operational requirements. (iii) The Administrator may... requirements of §§ 65.106 through 65.115 as provided in paragraph (d) of this section. If the Administrator...

  4. 'Why do an MPH?' Motivations and intentions of physicians undertaking postgraduate public health training at the University of Cape Town.

    PubMed

    Zweigenthal, Virginia E M; Marquez, Emma; London, Leslie

    2016-01-01

    Background Public health (PH) approaches underpin the management and transformation of health systems in low- and middle-income countries. Despite the Master of Public Health (MPH) rarely being a prerequisite for health service employment in South Africa, many physicians pursue MPH qualifications. Objectives This study identifies their motivations and career intentions and explored MPH programme strengths and gaps in under- and post-graduate PH training. Design A cross-sectional study using an online questionnaire was completed by physicians graduating with an MPH between 2000 and 2009 and those enrolled in the programme in 2010 at the University of Cape Town. Results Nearly a quarter of MPH students were physicians. Of the 65 contactable physicians, 48% responded. They were mid-career physicians who wished to obtain research training (55%), who wished to gain broader perspectives on health (32%), and who used the MPH to advance careers (90%) as researchers, policy-makers, or managers. The MPH widened professional opportunities, with 62% changing jobs. They believed that inadequate undergraduate exposure should be remedied by applying PH approaches to clinical problems in community settings, which would increase the attractiveness of postgraduate PH training. Conclusions The MPH allows physicians to transition from pure clinical to research, policy and/or management work, preparing them to innovate changes for effective health systems, responsive to the health needs of populations. Limited local job options and incentives are important constraining factors. Advocacy for positions requiring qualifications and benchmarking exit competencies of programmes nationally may promote enrolment.

  5. 'Why do an MPH?' Motivations and intentions of physicians undertaking postgraduate public health training at the University of Cape Town.

    PubMed

    Zweigenthal, Virginia E M; Marquez, Emma; London, Leslie

    2016-01-01

    Public health (PH) approaches underpin the management and transformation of health systems in low- and middle-income countries. Despite the Master of Public Health (MPH) rarely being a prerequisite for health service employment in South Africa, many physicians pursue MPH qualifications. This study identifies their motivations and career intentions and explored MPH programme strengths and gaps in under- and post-graduate PH training. A cross-sectional study using an online questionnaire was completed by physicians graduating with an MPH between 2000 and 2009 and those enrolled in the programme in 2010 at the University of Cape Town. Nearly a quarter of MPH students were physicians. Of the 65 contactable physicians, 48% responded. They were mid-career physicians who wished to obtain research training (55%), who wished to gain broader perspectives on health (32%), and who used the MPH to advance careers (90%) as researchers, policy-makers, or managers. The MPH widened professional opportunities, with 62% changing jobs. They believed that inadequate undergraduate exposure should be remedied by applying PH approaches to clinical problems in community settings, which would increase the attractiveness of postgraduate PH training. The MPH allows physicians to transition from pure clinical to research, policy and/or management work, preparing them to innovate changes for effective health systems, responsive to the health needs of populations. Limited local job options and incentives are important constraining factors. Advocacy for positions requiring qualifications and benchmarking exit competencies of programmes nationally may promote enrolment.

  6. 36 CFR 1004.21 - Speed limits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sections of Presidio Trust road under repair or construction. (3) 45 miles per hour: upon all other Presidio Trust roads. (b) The Board may designate a different speed limit upon any Presidio Trust road when...) An authorized person may utilize radiomicrowaves or other electrical devices to determine the speed...

  7. Topological speed limits to network synchronization.

    PubMed

    Timme, Marc; Wolf, Fred; Geisel, Theo

    2004-02-20

    We study collective synchronization of pulse-coupled oscillators interacting on asymmetric random networks. We demonstrate that random matrix theory can be used to accurately predict the speed of synchronization in such networks in dependence on the dynamical and network parameters. Furthermore, we show that the speed of synchronization is limited by the network connectivity and remains finite, even if the coupling strength becomes infinite. In addition, our results indicate that synchrony is robust under structural perturbations of the network dynamics.

  8. Geometric derivation of the quantum speed limit

    SciTech Connect

    Jones, Philip J.; Kok, Pieter

    2010-08-15

    The Mandelstam-Tamm and Margolus-Levitin inequalities play an important role in the study of quantum-mechanical processes in nature since they provide general limits on the speed of dynamical evolution. However, to date there has been only one derivation of the Margolus-Levitin inequality. In this paper, alternative geometric derivations for both inequalities are obtained from the statistical distance between quantum states. The inequalities are shown to hold for unitary evolution of pure and mixed states, and a counterexample to the inequalities is given for evolution described by completely positive trace-preserving maps. The counterexample shows that there is no quantum speed limit for nonunitary evolution.

  9. 14 CFR 65.81 - General privileges and limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.81 General privileges and limitations. (a) A certificated mechanic may perform or supervise the maintenance, preventive... supervision of a certificated and appropriately rated mechanic, or a certificated repairman, who has had...

  10. 14 CFR 65.81 - General privileges and limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.81 General privileges and limitations. (a) A certificated mechanic may perform or supervise the maintenance, preventive... supervision of a certificated and appropriately rated mechanic, or a certificated repairman, who has had...

  11. 14 CFR 65.81 - General privileges and limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.81 General privileges and limitations. (a) A certificated mechanic may perform or supervise the maintenance, preventive... supervision of a certificated and appropriately rated mechanic, or a certificated repairman, who has had...

  12. 14 CFR 65.81 - General privileges and limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.81 General privileges and limitations. (a) A certificated mechanic may perform or supervise the maintenance, preventive... supervision of a certificated and appropriately rated mechanic, or a certificated repairman, who has had...

  13. 14 CFR 65.81 - General privileges and limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.81 General privileges and limitations. (a) A certificated mechanic may perform or supervise the maintenance, preventive... supervision of a certificated and appropriately rated mechanic, or a certificated repairman, who has had...

  14. Time-limited optimal dynamics beyond the quantum speed limit

    NASA Astrophysics Data System (ADS)

    Gajdacz, Miroslav; Das, Kunal K.; Arlt, Jan; Sherson, Jacob F.; Opatrný, Tomáš

    2015-12-01

    The quantum speed limit sets the minimum time required to transfer a quantum system completely into a given target state. At shorter times the higher operation speed results in a loss of fidelity. Here we quantify the trade-off between the fidelity and the duration in a system driven by a time-varying control. The problem is addressed in the framework of Hilbert space geometry offering an intuitive interpretation of optimal control algorithms. This approach leads to a necessary criterion for control optimality applicable as a measure of algorithm convergence. The time fidelity trade-off expressed in terms of the direct Hilbert velocity provides a robust prediction of the quantum speed limit and allows one to adapt the control optimization such that it yields a predefined fidelity. The results are verified numerically in a multilevel system with a constrained Hamiltonian and a classification scheme for the control sequences is proposed based on their optimizability.

  15. ‘Why do an MPH?’ Motivations and intentions of physicians undertaking postgraduate public health training at the University of Cape Town

    PubMed Central

    Zweigenthal, Virginia E.M.; Marquez, Emma; London, Leslie

    2016-01-01

    Background Public health (PH) approaches underpin the management and transformation of health systems in low- and middle-income countries. Despite the Master of Public Health (MPH) rarely being a prerequisite for health service employment in South Africa, many physicians pursue MPH qualifications. Objectives This study identifies their motivations and career intentions and explored MPH programme strengths and gaps in under- and post-graduate PH training. Design A cross-sectional study using an online questionnaire was completed by physicians graduating with an MPH between 2000 and 2009 and those enrolled in the programme in 2010 at the University of Cape Town. Results Nearly a quarter of MPH students were physicians. Of the 65 contactable physicians, 48% responded. They were mid-career physicians who wished to obtain research training (55%), who wished to gain broader perspectives on health (32%), and who used the MPH to advance careers (90%) as researchers, policy-makers, or managers. The MPH widened professional opportunities, with 62% changing jobs. They believed that inadequate undergraduate exposure should be remedied by applying PH approaches to clinical problems in community settings, which would increase the attractiveness of postgraduate PH training. Conclusions The MPH allows physicians to transition from pure clinical to research, policy and/or management work, preparing them to innovate changes for effective health systems, responsive to the health needs of populations. Limited local job options and incentives are important constraining factors. Advocacy for positions requiring qualifications and benchmarking exit competencies of programmes nationally may promote enrolment. PMID:27741958

  16. Quantum speed limits in open system dynamics.

    PubMed

    del Campo, A; Egusquiza, I L; Plenio, M B; Huelga, S F

    2013-02-01

    Bounds to the speed of evolution of a quantum system are of fundamental interest in quantum metrology, quantum chemical dynamics, and quantum computation. We derive a time-energy uncertainty relation for open quantum systems undergoing a general, completely positive, and trace preserving evolution which provides a bound to the quantum speed limit. When the evolution is of the Lindblad form, the bound is analogous to the Mandelstam-Tamm relation which applies in the unitary case, with the role of the Hamiltonian being played by the adjoint of the generator of the dynamical semigroup. The utility of the new bound is exemplified in different scenarios, ranging from the estimation of the passage time to the determination of precision limits for quantum metrology in the presence of dephasing noise.

  17. Quantum speed limits, coherence, and asymmetry

    NASA Astrophysics Data System (ADS)

    Marvian, Iman; Spekkens, Robert W.; Zanardi, Paolo

    2016-05-01

    The resource theory of asymmetry is a framework for classifying and quantifying the symmetry-breaking properties of both states and operations relative to a given symmetry. In the special case where the symmetry is the set of translations generated by a fixed observable, asymmetry can be interpreted as coherence relative to the observable eigenbasis, and the resource theory of asymmetry provides a framework to study this notion of coherence. We here show that this notion of coherence naturally arises in the context of quantum speed limits. Indeed, the very concept of speed of evolution, i.e., the inverse of the minimum time it takes the system to evolve to another (partially) distinguishable state, is a measure of asymmetry relative to the time translations generated by the system Hamiltonian. Furthermore, the celebrated Mandelstam-Tamm and Margolus-Levitin speed limits can be interpreted as upper bounds on this measure of asymmetry by functions which are themselves measures of asymmetry in the special case of pure states. Using measures of asymmetry that are not restricted to pure states, such as the Wigner-Yanase skew information, we obtain extensions of the Mandelstam-Tamm bound which are significantly tighter in the case of mixed states. We also clarify some confusions in the literature about coherence and asymmetry, and show that measures of coherence are a proper subset of measures of asymmetry.

  18. Limiting Speed of the Bacterial Flagellar Motor

    NASA Astrophysics Data System (ADS)

    Nirody, Jasmine; Berry, Richard; Oster, George

    The bacterial flagellar motor (BFM) drives swimming in a wide variety of bacterial species, making it crucial for several fundamental biological processes including chemotaxis and community formation. Recent experiments have shown that the structure of this nanomachine is more dynamic than previously believed. Specifically, the number of active torque-generating units (stators) was shown to vary across applied loads. This finding invalidates the experimental evidence reporting that limiting (zero-torque) speed is independent of the number of active stators. Here, we put forward a model for the torque generation mechanism of this motor and propose that the maximum speed of the motor increases as additional torque-generators are recruited. This is contrary to the current widely-held belief that there is a universal upper limit to the speed of the BFM. Our result arises from the assumption that stators disengage from the motor for a significant portion of their mechanochemical cycles at low loads. We show that this assumption is consistent with current experimental evidence and consolidate our predictions with arguments that a processive motor must have a high duty ratio at high loads.

  19. 14 CFR 25.1505 - Maximum operating limit speed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Maximum operating limit speed. 25.1505... Operating Limitations § 25.1505 Maximum operating limit speed. The maximum operating limit speed (V MO/M MO airspeed or Mach Number, whichever is critical at a particular altitude) is a speed that may not be...

  20. 14 CFR 25.1505 - Maximum operating limit speed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum operating limit speed. 25.1505... Operating Limitations § 25.1505 Maximum operating limit speed. The maximum operating limit speed (V MO/M MO airspeed or Mach Number, whichever is critical at a particular altitude) is a speed that may not be...

  1. 14 CFR 25.1505 - Maximum operating limit speed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maximum operating limit speed. 25.1505... Operating Limitations § 25.1505 Maximum operating limit speed. The maximum operating limit speed (V MO/M MO airspeed or Mach Number, whichever is critical at a particular altitude) is a speed that may not be...

  2. 14 CFR 25.1505 - Maximum operating limit speed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum operating limit speed. 25.1505... Operating Limitations § 25.1505 Maximum operating limit speed. The maximum operating limit speed (V MO/M MO airspeed or Mach Number, whichever is critical at a particular altitude) is a speed that may not be...

  3. 14 CFR 25.1505 - Maximum operating limit speed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maximum operating limit speed. 25.1505... Operating Limitations § 25.1505 Maximum operating limit speed. The maximum operating limit speed (V MO/M MO airspeed or Mach Number, whichever is critical at a particular altitude) is a speed that may not be...

  4. Quantum Speed Limits for Leakage and Decoherence

    NASA Astrophysics Data System (ADS)

    Marvian, Iman; Lidar, Daniel A.

    2015-11-01

    We introduce state-independent, nonperturbative Hamiltonian quantum speed limits for population leakage and fidelity loss, for a gapped open system interacting with a reservoir. These results hold in the presence of initial correlations between the system and the reservoir, under the sole assumption that their interaction and its commutator with the reservoir Hamiltonian are norm bounded. The reservoir need not be thermal and can be time dependent. We study the significance of energy mismatch between the system and the local degrees of freedom of the reservoir that directly interact with the system. We demonstrate that, in general, by increasing the system gap we may reduce this energy mismatch, and, consequently, drive the system and the reservoir into resonance; this can accelerate fidelity loss, irrespective of the thermal properties or state of the reservoir. This implies that quantum error suppression strategies based on increasing the gap are not uniformly beneficial. Our speed limits also yield an elementary lower bound on the relaxation time of spin systems.

  5. The effect of laser speed-measuring devices on speed limit law enforcement in Charleston, South Carolina.

    PubMed

    Teed, N; Lund, A K

    1993-08-01

    Drivers exceeding the speed limit by more than 10 mph were identified and ticketed by the Charleston County, South Carolina police using two types of speed measuring devices: conventional police radar and a new laser device. The two types of enforcement were used alternately on the same roads at similar times. Under the laser enforcement condition, the police issued 534 tickets (54%) compared with 457 (46%) under radar enforcement. The increase in tickets issued under laser enforcement was observed at three of the four study sites, and the number of tickets per traffic volume increased at two of the three sites for which traffic volumes were available. Speeders ticketed under the laser enforcement condition were four times as likely to have radar detectors as those ticketed under the radar enforcement condition. Most of the additional speeders caught by the laser were using radar detectors. These data indicate that some speeders with radar detectors are avoiding detection when the police enforce the limit with radar.

  6. 14 CFR 25.1516 - Other speed limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Other speed limitations. 25.1516 Section 25.1516 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 25.1516 Other speed limitations. Any other limitation associated with speed must be established. ...

  7. 14 CFR 25.1516 - Other speed limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Other speed limitations. 25.1516 Section 25.1516 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 25.1516 Other speed limitations. Any other limitation associated with speed must be established. ...

  8. 14 CFR 25.1516 - Other speed limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Other speed limitations. 25.1516 Section 25.1516 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 25.1516 Other speed limitations. Any other limitation associated with speed must be established. ...

  9. 14 CFR 25.1516 - Other speed limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Other speed limitations. 25.1516 Section 25.1516 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 25.1516 Other speed limitations. Any other limitation associated with speed must be established. ...

  10. 14 CFR 25.1516 - Other speed limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Other speed limitations. 25.1516 Section 25.1516 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 25.1516 Other speed limitations. Any other limitation associated with speed must be established. ...

  11. Preheating with a speed-limited inflaton

    NASA Astrophysics Data System (ADS)

    Karouby, Johanna; Underwood, Bret; Vincent, Aaron C.

    2011-08-01

    We study preheating in models where the inflaton has a noncanonical kinetic term, containing powers of the usual kinetic energy. The inflaton field oscillating about its potential minimum acts as a driving force for particle production through parametric resonance. Noncanonical kinetic terms can impose a speed limit on the motion of the inflaton, modifying the oscillating inflaton profile. This has two important effects: it turns a smooth sinusoidal profile into a sharp saw-tooth, enhancing resonance, and it lengthens the period of oscillations, suppressing resonance. We show that the second effect dominates over the first, so that preheating with a noncanonical inflaton field is less efficient than with canonical kinetic terms, and that the expansion of the Universe suppresses resonance even further.

  12. 14 CFR 23.33 - Propeller speed and pitch limits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller speed and pitch limits. 23.33 Section 23.33 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Propeller speed and pitch limits. (a) General. The propeller speed and pitch must be limited to values...

  13. 49 CFR 213.329 - Curves; elevation and speed limitations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Curves; elevation and speed limitations. 213.329... Higher § 213.329 Curves; elevation and speed limitations. (a) The maximum elevation of the outside rail... limits in § 213.331 apply in all cases. (b) The maximum allowable posted timetable operating speed for...

  14. 14 CFR 29.1517 - Limiting height-speed envelope.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Limiting height-speed envelope. 29.1517... Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of heights exists at any speed, including zero, within which it is not possible to make a safe landing...

  15. 14 CFR 25.33 - Propeller speed and pitch limits.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller speed and pitch limits. 25.33... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight General § 25.33 Propeller speed and pitch limits. (a) The propeller speed and pitch must be limited to values that will ensure— (1) Safe operation...

  16. 49 CFR 213.329 - Curves; elevation and speed limitations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Curves; elevation and speed limitations. 213.329... Higher § 213.329 Curves; elevation and speed limitations. (a) The maximum elevation of the outside rail... limits in § 213.331 apply in all cases. (b) The maximum allowable posted timetable operating speed for...

  17. 14 CFR 25.33 - Propeller speed and pitch limits.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller speed and pitch limits. 25.33... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight General § 25.33 Propeller speed and pitch limits. (a) The propeller speed and pitch must be limited to values that will ensure— (1) Safe operation...

  18. Cytomegalovirus pp65 limits dissemination but is dispensable for persistence

    PubMed Central

    Malouli, Daniel; Hansen, Scott G.; Nakayasu, Ernesto S.; Marshall, Emily E.; Hughes, Colette M.; Ventura, Abigail B.; Gilbride, Roxanne M.; Lewis, Matthew S.; Xu, Guangwu; Kreklywich, Craig; Whizin, Nathan; Fischer, Miranda; Legasse, Alfred W.; Viswanathan, Kasinath; Siess, Don; Camp, David G.; Axthelm, Michael K.; Kahl, Christoph; DeFilippis, Victor R.; Smith, Richard D.; Streblow, Daniel N.; Picker, Louis J.; Früh, Klaus

    2014-01-01

    The most abundantly produced virion protein in human cytomegalovirus (HCMV) is the immunodominant phosphoprotein 65 (pp65), which is frequently included in CMV vaccines. Although it is nonessential for in vitro CMV growth, pp65 displays immunomodulatory functions that support a potential role in primary and/or persistent infection. To determine the contribution of pp65 to CMV infection and immunity, we generated a rhesus CMV lacking both pp65 orthologs (RhCMVΔpp65ab). While deletion of pp65ab slightly reduced growth in vitro and increased defective particle formation, the protein composition of secreted virions was largely unchanged. Interestingly, pp65 was not required for primary and persistent infection in animals. Immune responses induced by RhCMVΔpp65ab did not prevent reinfection with rhesus CMV; however, reinfection with RhCMVΔUS2-11, which lacks viral-encoded MHC-I antigen presentation inhibitors, was prevented. Unexpectedly, induction of pp65b-specific T cells alone did not protect against RhCMVΔUS2-11 challenge, suggesting that T cells targeting multiple CMV antigens are required for protection. However, pp65-specific immunity was crucial for controlling viral dissemination during primary infection, as indicated by the marked increase of RhCMVΔpp65ab genome copies in CMV-naive, but not CMV-immune, animals. Our data provide rationale for inclusion of pp65 into CMV vaccines but also demonstrate that pp65-induced T cell responses alone do not recapitulate the protective effect of natural infection. PMID:24691437

  19. Cytomegalovirus pp65 limits dissemination but is dispensable for persistence

    SciTech Connect

    Malouli, Daniel; Hansen, Scott G.; Nakayasu, Ernesto S.; Marshall, Emily E.; Hughes, Colette M.; Ventura, Abigail B.; Gilbride, Roxanne M.; Lewis, Matthew S.; Xu, Guangwu; Kreklywich, Craig; Whizin, Nathan; Fischer, Miranda; Legasse, Alfred W.; Viswanathan, Kasinath; Siess, Don; Camp, David G.; Axthelm, Michael K.; Kahl, Christoph; DeFilippis, Victor R.; Smith, Richard D.; Streblow, Daniel N.; Picker, Louis J.; Früh, Klaus

    2014-04-01

    The tegument phosphoprotein pp65 (UL83) is the most abundant virion protein in human cytomegalovirus (HCMV). Since pp65 is immunodominant in persistently infected individuals, subunit vaccines against HCMV often include pp65 as T cell stimulatory component. Although HCMV pp65 is non-essential for viral growth in vitro it is thought to have an important role in primary and persistent infection since pp65 displays multiple immunomodulatory functions. To determine whether pp65 is required for infection and to evaluate its role in natural and vaccination-induced immunity we generated a rhesus CMV lacking both homologues, pp65a (Rh111) and pp65b (Rh112). Lack of pp65 resulted in a slight growth defect in vitro and an increase of defective particle formation. However, most pp65-deleted virions in the supernatant were phenotypically normal and proteomics analysis revealed that the ratios of the remaining viral proteins were largely unchanged. RhCMV Δpp65ab was able to persistently infect CMV-negative rhesus macaques (RM) and to super-infect RM previously infected with CMV. To determine whether T cells against pp65 are essential for protection against CMV, we challenged Δpp65ab-infected animals with RhCMV ΔUS2-11, a viral recombinant that lacks inhibitors of MHC-I antigen presentation and is thus unable to overcome CMV-specific T cell immunity. Despite a complete lack of pp65-specific T cells, Δpp65ab protected against ΔUS2-11 challenge suggesting that pp65-specific T cells are not essential for T cell immunity against CMV. Using the same approach we further demonstrate that pp65b-specific T cells, induced by heterologous prime/boost vaccination, are not sufficient to protect against ΔUS2-11 challenge. Our data provides a new approach to test the efficacy of subunit vaccine candidates and suggest that pp65 vaccines are insufficient to induce a T cell response that recapitulates the protective effect of natural infection.

  20. Perils of using speed zone data to assess real-world compliance to speed limits.

    PubMed

    Chevalier, Anna; Clarke, Elizabeth; Chevalier, Aran John; Brown, Julie; Coxon, Kristy; Ivers, Rebecca; Keay, Lisa

    2017-11-17

    Real-world driving studies, including those involving speeding alert devices and autonomous vehicles, can gauge an individual vehicle's speeding behavior by comparing measured speed with mapped speed zone data. However, there are complexities with developing and maintaining a database of mapped speed zones over a large geographic area that may lead to inaccuracies within the data set. When this approach is applied to large-scale real-world driving data or speeding alert device data to determine speeding behavior, these inaccuracies may result in invalid identification of speeding. We investigated speeding events based on service provider speed zone data. We compared service provider speed zone data (Speed Alert by Smart Car Technologies Pty Ltd., Ultimo, NSW, Australia) against a second set of speed zone data (Google Maps Application Programming Interface [API] mapped speed zones). We found a systematic error in the zones where speed limits of 50-60 km/h, typical of local roads, were allocated to high-speed motorways, which produced false speed limits in the speed zone database. The result was detection of false-positive high-range speeding. Through comparison of the service provider speed zone data against a second set of speed zone data, we were able to identify and eliminate data most affected by this systematic error, thereby establishing a data set of speeding events with a high level of sensitivity (a true positive rate of 92% or 6,412/6,960). Mapped speed zones can be a source of error in real-world driving when examining vehicle speed. We explored the types of inaccuracies found within speed zone data and recommend that a second set of speed zone data be utilized when investigating speeding behavior or developing mapped speed zone data to minimize inaccuracy in estimates of speeding.

  1. Dynamic Speed Adaptation for Path Tracking Based on Curvature Information and Speed Limits

    PubMed Central

    Gámez Serna, Citlalli; Ruichek, Yassine

    2017-01-01

    A critical concern of autonomous vehicles is safety. Different approaches have tried to enhance driving safety to reduce the number of fatal crashes and severe injuries. As an example, Intelligent Speed Adaptation (ISA) systems warn the driver when the vehicle exceeds the recommended speed limit. However, these systems only take into account fixed speed limits without considering factors like road geometry. In this paper, we consider road curvature with speed limits to automatically adjust vehicle’s speed with the ideal one through our proposed Dynamic Speed Adaptation (DSA) method. Furthermore, ‘curve analysis extraction’ and ‘speed limits database creation’ are also part of our contribution. An algorithm that analyzes GPS information off-line identifies high curvature segments and estimates the speed for each curve. The speed limit database contains information about the different speed limit zones for each traveled path. Our DSA senses speed limits and curves of the road using GPS information and ensures smooth speed transitions between current and ideal speeds. Through experimental simulations with different control algorithms on real and simulated datasets, we prove that our method is able to significantly reduce lateral errors on sharp curves, to respect speed limits and consequently increase safety and comfort for the passenger. PMID:28613251

  2. 49 CFR 213.329 - Curves, elevation and speed limitations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Curves, elevation and speed limitations. 213.329... Higher § 213.329 Curves, elevation and speed limitations. (a) The maximum crosslevel on the outside rail... lower than the inside rail. (b) (1) The maximum allowable operating speed for each curve is determined...

  3. 49 CFR 213.329 - Curves, elevation and speed limitations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Curves, elevation and speed limitations. 213.329... Higher § 213.329 Curves, elevation and speed limitations. (a) The maximum crosslevel on the outside rail... lower than the inside rail. (b) (1) The maximum allowable operating speed for each curve is determined...

  4. 49 CFR 213.329 - Curves, elevation and speed limitations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Curves, elevation and speed limitations. 213.329... Higher § 213.329 Curves, elevation and speed limitations. (a) The maximum crosslevel on the outside rail... lower than the inside rail. (b) (1) The maximum allowable operating speed for each curve is determined...

  5. LIMITS TO ICE ON ASTEROIDS (24) THEMIS AND (65) CYBELE

    SciTech Connect

    Jewitt, David; Guilbert-Lepoutre, Aurelie

    2012-01-15

    We present optical spectra of (24) Themis and (65) Cybele, two large main-belt asteroids on which exposed water ice has recently been reported. No emission lines, expected from resonance fluorescence in gas sublimated from the ice, were detected. Derived limits to the production rates of water are {approx}<400 kg s{sup -1} (5{sigma}) for each object, assuming a cometary H{sub 2}O/CN ratio. We rule out models in which a large fraction of the surface is occupied by high-albedo ('fresh') water ice because the measured albedos of Themis and Cybele are low ({approx}0.05-0.07). We also rule out models in which a large fraction of the surface is occupied by low-albedo ('dirty') water ice because dirty ice would be warm and would sublimate strongly enough for gaseous products to have been detected. If ice exists on these bodies it must be relatively clean (albedo {approx}>0.3) and confined to a fraction of the Earth-facing surface {approx}<10%. By analogy with impacted asteroid (596) Scheila, we propose an impact excavation scenario, in which 10 m scale projectiles have exposed buried ice. If the ice is even more reflective (albedo {approx}>0.6), then the timescale for sublimation of an optically thick layer can rival the {approx}10{sup 3} yr interval between impacts with bodies this size. In this sense, exposure by impact may be a quasi steady-state feature of ice-containing asteroids at 3 AU.

  6. Should We Raise the Reading Speed Limit?

    ERIC Educational Resources Information Center

    Berliner, David; Casanova, Ursula

    1988-01-01

    A recent study of reading rates of first grade students in Israel and America indicates that increased reading speed may improve comprehension and oral reading. Based on this finding, activities to help students read faster (and better) are suggested. (JL)

  7. 14 CFR 65.95 - Inspection authorization: Privileges and limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.95... the aircraft owner, the mechanic submitting the aircraft, repair, or alteration for approval (if any...

  8. 14 CFR 65.95 - Inspection authorization: Privileges and limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.95... the aircraft owner, the mechanic submitting the aircraft, repair, or alteration for approval (if any...

  9. 14 CFR 65.95 - Inspection authorization: Privileges and limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.95... the aircraft owner, the mechanic submitting the aircraft, repair, or alteration for approval (if any...

  10. 14 CFR 65.95 - Inspection authorization: Privileges and limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.95... the aircraft owner, the mechanic submitting the aircraft, repair, or alteration for approval (if any...

  11. 14 CFR 65.95 - Inspection authorization: Privileges and limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.95... the aircraft owner, the mechanic submitting the aircraft, repair, or alteration for approval (if any...

  12. Frailty prevalence and slow walking speed in persons age 65 and older: implications for primary care

    PubMed Central

    2013-01-01

    Background Frailty in the elderly increases their vulnerability and leads to a greater risk of adverse events. According to various studies, the prevalence of the frailty syndrome in persons age 65 and over ranges between 3% and 37%, depending on age and sex. Walking speed in itself is considered a simple indicator of health status and of survival in older persons. Detecting frailty in primary care consultations can help improve care of the elderly, and walking speed may be an indicator that could facilitate the early diagnosis of frailty in primary care. The objective of this work was to estimate frailty-syndrome prevalence and walking speed in an urban population aged 65 years and over, and to analyze the relationship between the two indicators from the perspective of early diagnosis of frailty in the primary care setting. Methods Population cohort of persons age 65 and over from two urban neighborhoods in northern Madrid (Spain). Cross-sectional analysis. Bivariate and multivariate analysis with binary logistic regression to study the variables associated with frailty. Different cut-off points between 0.4 and 1.4 m/s were used to study walking speed in this population. The relationship between frailty and walking speed was analyzed using likelihood ratios. Results The study sample comprised 1,327 individuals age 65 and older with mean age 75.41 ± 7.41 years; 53.4% were women. Estimated frailty in the study population was 10.5% [95% CI: 8.9-12.3]. Frailty increased with age (OR = 1.14; 95% CI: 1.10-1.19) and was associated with poor self-rated health (OR = 2.52; 95% CI: 1.43-4.44), number of drugs prescribed (OR = 1.17; 95% CI: 1.08-1.26) and disability (OR = 6.58; 95% CI: 3.92-11.05). Walking speed less than 0.8 m/s was found in 42.6% of cases and in 56.4% of persons age 75 and over. Walking speed greater than 0.9 m/s ruled out frailty in the study sample. Persons age 75 and older with walking speed <0.8 m/s are at particularly high

  13. 40 CFR 65.102 - Alternative means of emission limitation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... means of emission limitation. (ii) The Administrator will compare test data for the means of emission... of emission limitation. (iii) The Administrator will compare the demonstrated emission reduction...

  14. Motor vehicle driver death and high state maximum speed limits: 1991-1993.

    PubMed

    Yamane, Grover K; Bradshaw, Benjamin S

    2008-09-01

    To measure the association between motor vehicle crash (MVC) driver death and high state maximum speed limits. This study used a case-control design and assessed driver deaths from three major types of MVCs: non-collision; collision with motor vehicles in transit; and collision with stationary objects. The study period was 1991-1993. For each type of crash, case subject populations of fatally injured drivers were obtained from the U.S. Department of Transportation Fatality Analysis Reporting System. Four control subject populations, each associated with a different cause of death, were obtained from a U.S. national death certificate database (the causes of death were unintentional poisoning, non-Hodgkin lymphoma, drowning, and diabetes mellitus). Subjects were considered exposed if the state in which they crashed (for cases) or died (for controls) had a maximum speed limit greater than 55 mph. Each of the three case subject populations was compared against each of the four control subject populations. Odds ratios (ORs) were adjusted for age and gender. For non-collision driver death, ORs ranged from 3.06 to 6.56, depending on the year and control group; all the ORs were significant. For collision with motor vehicles in transit driver death, ORs ranged from 1.12 to 2.22; all the ORs were significant. For collision with stationary objects driver death, ORs ranged from 0.87 to 1.83. There was a moderately strong and significant association between non-collision driver death and high state maximum speed limits. For collision with motor vehicles in transit driver death, the association was somewhat milder but still consistent. For collision with stationary objects driver death, the presence of an association was unclear. During 1991-1993, the effects of high state maximum speed limits may have been different for different types of MVCs.

  15. 14 CFR 29.1517 - Limiting height-speed envelope.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Operating Limitations and Information Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of... following power failure, the range of heights and its variation with forward speed must be...

  16. 14 CFR 29.1517 - Limiting height-speed envelope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Operating Limitations and Information Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of... following power failure, the range of heights and its variation with forward speed must be...

  17. 14 CFR 29.1517 - Limiting height-speed envelope.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Operating Limitations and Information Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of... following power failure, the range of heights and its variation with forward speed must be...

  18. 14 CFR 29.1517 - Limiting height-speed envelope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Operating Limitations and Information Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of... following power failure, the range of heights and its variation with forward speed must be...

  19. A Health Impact Assessment of a Proposed Bill to Decrease Speed Limits on Local Roads in Massachusetts (U.S.A.)

    PubMed Central

    James, Peter; Ito, Kate; Banay, Rachel F.; Buonocore, Jonathan J.; Wood, Benjamin; Arcaya, Mariana C.

    2014-01-01

    Decreasing traffic speeds increases the amount of time drivers have to react to road hazards, potentially averting collisions, and makes crashes that do happen less severe. Boston’s regional planning agency, the Metropolitan Area Planning Council (MAPC), in partnership with the Massachusetts Department of Public Health (MDPH), conducted a Health Impact Assessment (HIA) that examined the potential health impacts of a proposed bill in the state legislature to lower the default speed limits on local roads from 30 miles per hour (mph) to 25 mph. The aim was to reduce vehicle speeds on local roads to a limit that is safer for pedestrians, cyclists, and children. The passage of this proposed legislation could have had far-reaching and potentially important public health impacts. Lower default speed limits may prevent around 18 fatalities and 1200 serious injuries to motorists, cyclists and pedestrians each year, as well as promote active transportation by making local roads feel more hospitable to cyclists and pedestrians. While a lower speed limit would increase congestion and slightly worsen air quality, the benefits outweigh the costs from both a health and economic perspective and would save the state approximately $62 million annually from prevented fatalities and injuries. PMID:25279544

  20. A health impact assessment of a proposed bill to decrease speed limits on local roads in Massachusetts (U.S.A.).

    PubMed

    James, Peter; Ito, Kate; Banay, Rachel F; Buonocore, Jonathan J; Wood, Benjamin; Arcaya, Mariana C

    2014-10-02

    Decreasing traffic speeds increases the amount of time drivers have to react to road hazards, potentially averting collisions, and makes crashes that do happen less severe. Boston's regional planning agency, the Metropolitan Area Planning Council (MAPC), in partnership with the Massachusetts Department of Public Health (MDPH), conducted a Health Impact Assessment (HIA) that examined the potential health impacts of a proposed bill in the state legislature to lower the default speed limits on local roads from 30 miles per hour (mph) to 25 mph. The aim was to reduce vehicle speeds on local roads to a limit that is safer for pedestrians, cyclists, and children. The passage of this proposed legislation could have had far-reaching and potentially important public health impacts. Lower default speed limits may prevent around 18 fatalities and 1200 serious injuries to motorists, cyclists and pedestrians each year, as well as promote active transportation by making local roads feel more hospitable to cyclists and pedestrians. While a lower speed limit would increase congestion and slightly worsen air quality, the benefits outweigh the costs from both a health and economic perspective and would save the state approximately $62 million annually from prevented fatalities and injuries.

  1. 40 CFR 1037.640 - Variable vehicle speed limiters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... soft-top speed limit. You may also design your VSL to expire after accumulation of a predetermined number of miles. However, designs with soft tops or expiration features are subject to proration...) of this section. (ii) For VSLs with soft tops, the default speed does not include speeds...

  2. Speed limits in Liouville space for open quantum systems

    NASA Astrophysics Data System (ADS)

    Uzdin, Raam; Kosloff, Ronnie

    2016-08-01

    One of the defining properties of an open quantum system is the variation of its purity in time. We derive speed limits on the rate of purity change for systems coupled to a Markovian environment. Our speed limits are based on Liouville space where density matrices are represented as vectors. This approach leads to speed limits that are always tighter compared to their parallel speed limits in Hilbert space. These bounds depend solely on the generators of the nonunitary dynamics and are independent of the particular state of the systems. Thus, they are perfectly suited to investigate dephasing, thermalization, and decorrelation processes of arbitrary states. We show that our speed limits can be attained and are therefore tight. As an application of our results we study dephasing of interacting spins, and the speed of classical and quantum correlation erasure in multi-particle system.

  3. 41 CFR 102-73.65 - Are there any limitations on leasing certain types of space?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... limitations on leasing certain types of space? 102-73.65 Section 102-73.65 Public Contracts and Property... PROPERTY 73-REAL ESTATE ACQUISITION Acquisition by Lease § 102-73.65 Are there any limitations on leasing certain types of space? Yes, the limitations on leasing certain types of space are as follows: (a)...

  4. 41 CFR 102-73.65 - Are there any limitations on leasing certain types of space?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... limitations on leasing certain types of space? 102-73.65 Section 102-73.65 Public Contracts and Property... PROPERTY 73-REAL ESTATE ACQUISITION Acquisition by Lease § 102-73.65 Are there any limitations on leasing certain types of space? Yes, the limitations on leasing certain types of space are as follows: (a)...

  5. 41 CFR 102-73.65 - Are there any limitations on leasing certain types of space?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... limitations on leasing certain types of space? 102-73.65 Section 102-73.65 Public Contracts and Property... PROPERTY 73-REAL ESTATE ACQUISITION Acquisition by Lease § 102-73.65 Are there any limitations on leasing certain types of space? Yes, the limitations on leasing certain types of space are as follows: (a)...

  6. 41 CFR 102-73.65 - Are there any limitations on leasing certain types of space?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... limitations on leasing certain types of space? 102-73.65 Section 102-73.65 Public Contracts and Property... PROPERTY 73-REAL ESTATE ACQUISITION Acquisition by Lease § 102-73.65 Are there any limitations on leasing certain types of space? Yes, the limitations on leasing certain types of space are as follows: (a)...

  7. 41 CFR 102-73.65 - Are there any limitations on leasing certain types of space?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... limitations on leasing certain types of space? 102-73.65 Section 102-73.65 Public Contracts and Property... PROPERTY 73-REAL ESTATE ACQUISITION Acquisition by Lease § 102-73.65 Are there any limitations on leasing certain types of space? Yes, the limitations on leasing certain types of space are as follows: (a)...

  8. 36 CFR § 1004.21 - Speed limits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hour: upon sections of Presidio Trust road under repair or construction. (3) 45 miles per hour: upon all other Presidio Trust roads. (b) The Board may designate a different speed limit upon any Presidio Trust road when a speed limit set forth in paragraph (a) of this section is determined to be...

  9. 40 CFR 1037.640 - Variable vehicle speed limiters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Variable vehicle speed limiters. 1037... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES Special Compliance Provisions § 1037.640 Variable vehicle speed limiters. This section specifies provisions that apply for...

  10. 40 CFR 1037.640 - Variable vehicle speed limiters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Variable vehicle speed limiters. 1037... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES Special Compliance Provisions § 1037.640 Variable vehicle speed limiters. This section specifies provisions that apply for...

  11. Exceeding the speed limit: prevalence and determinants in Iran.

    PubMed

    Moradi, Ali; Motevalian, Seyed Abbas; Mirkoohi, Maryam; McKay, Mary Pat; Rahimi-Movaghar, Vafa

    2013-01-01

    Speeding is one of the most common risk behaviours associated with crashes causing signficant injury. The objective of this study is to explore the prevalence and determinants of speeding on a road between Tehran and Hamadan, Iran. In a cross-sectional study in 2009, stretches of the road were studied including three groups of posted speed limits: < 50 km/h, 50-100 km/h and > 100 km/h. Each stretch was evaluated both in daylight and dark. Randomly identified driver's speed was checked by a handheld speed camera and then the driver was invited to participate in a survey. Statistical analysis was performed using Chi-Square, crude and adjusted odds ratio, 95% confidence interval and multiple logistic regression models. Overall, 52.8% of the drivers were travelling more than 10 km/h above the posted limit. Where limits were < 50 km/h, 74.6% of drivers were speeding. This declined to 46.9% for sections with limits between 50 and 100 km/h and to 36.9% for sections posted more than 100 km/h. Finally, more than half the drivers were observed to be speeding. Driving more than the posted limit was far more likely on the areas with the lowest posted speed limits, personal passenger vehicles, modern vehicles not using seat belts, and male drivers.

  12. Limits to running speed in dogs, horses and humans.

    PubMed

    Denny, Mark W

    2008-12-01

    Are there absolute limits to the speed at which animals can run? If so, how close are present-day individuals to these limits? I approach these questions by using three statistical models and data from competitive races to estimate maximum running speeds for greyhounds, thoroughbred horses and elite human athletes. In each case, an absolute speed limit is definable, and the current record approaches that predicted maximum. While all such extrapolations must be used cautiously, these data suggest that there are limits to the ability of either natural or artificial selection to produce ever faster dogs, horses and humans. Quantification of the limits to running speed may aid in formulating and testing models of locomotion.

  13. Quantum speed limits for Bell-diagonal states

    NASA Astrophysics Data System (ADS)

    Han, Wei; Jiang, Ke-Xia; Zhang, Ying-Jie; Xia, Yun-Jie

    2015-12-01

    The lower bounds of the evolution time between two distinguishable states of a system, defined as quantum speed limit time, can characterize the maximal speed of quantum computers and communication channels. We study the quantum speed limit time between the composite quantum states and their target states in the presence of nondissipative decoherence. For the initial states with maximally mixed marginals, we obtain the exact expressions of the quantum speed limit time which mainly depend on the parameters of the initial states and the decoherence channels. Furthermore, by calculating the quantum speed limit time for the time-dependent states started from a class of initial states, we discover that the quantum speed limit time gradually decreases in time, and the decay rate of the quantum speed limit time would show a sudden change at a certain critical time. Interestingly, at the same critical time, the composite system dynamics would exhibit a sudden transition from classical decoherence to quantum decoherence. Project supported by the National Natural Science Foundation of China (Grant Nos. 61178012 and 11304179), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant Nos. 20123705120002 and 20133705110001), the Natural Science Foundation of Shandong Province of China (Grant No. ZR2014AP009), and the Scientific Research Foundation of Qufu Normal University.

  14. Enforcement of speed limits--actual policy and drivers' knowledge.

    PubMed

    Jørgensen, Finn; Pedersen, Hassa

    2005-01-01

    This paper reviews the penalty rules and examines drivers' perceptions of enforcement of speed limits. The survey was carried out using a sample of 204 Norwegian drivers, answering questions in a setting closely associated with their driving situation. For minor speeding offences drivers overestimated on average their fines. For serious speeding offences drivers significantly underestimated how many kilometers per hour they could exceed the speed limits before losing their driving license. They also overestimated the probability of being caught speeding. This resulted in a perceived expected penalty twice the real one. The paper also examines the relationship between different driver characteristics and their knowledge of the enforcement policy for speeding. Older drivers had less knowledge about the threshold level for serious speeding but more knowledge about the detection rate than younger drivers do. Experienced drivers had more knowledge about the threshold level for serious speeding than inexperienced drivers. The number of times drivers were stopped due to speeding offences increased their knowledge of fines for minor speeding.

  15. Fundamental Speed Limits to the Generation of Quantumness

    PubMed Central

    Jing, Jun; Wu, Lian-Ao; del Campo, Adolfo

    2016-01-01

    Quantum physics dictates fundamental speed limits during time evolution. We present a quantum speed limit governing the generation of nonclassicality and the mutual incompatibility of two states connected by time evolution. This result is used to characterize the timescale required to generate a given amount of quantumness under an arbitrary physical process. The bound is found to be tight under pure dephasing dynamics. More generally, our analysis reveals the dependence on the initial and final states and non-Markovian effects. PMID:27901118

  16. 40 CFR 65.8 - Procedures for approval of alternative means of emission limitation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 16 2014-07-01 2014-07-01 false Procedures for approval of alternative means of emission limitation. 65.8 Section 65.8 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions § 65.8...

  17. 40 CFR 65.8 - Procedures for approval of alternative means of emission limitation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Procedures for approval of alternative means of emission limitation. 65.8 Section 65.8 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions § 65.8...

  18. Factors that influence full-time MPH Students' willingness in China: would You apply again for an MPH graduate degree if you had another opportunity?

    PubMed

    Wang, Nan; Jia, Jinzhong; Wu, Ke; Wang, Yuanyuan; Zhang, Chi; Cao, Wei; Duan, Liping; Wang, Zhifeng

    2017-02-14

    Current and emerging challenges to public health in the 21st century are vastly different from those faced in previous centuries. And the shortage of health personnel and their low level of educational qualifications hindered the development of Chinese public health services. In order to fulfill this requirement, the Ministry of Education initiated a full-time, Master of Public Health (MPH) graduate programme in 2009. This study aimed to evaluate the level of graduate students' satisfaction with full-time Master of Public Health (MPH) education in China, and whether they would apply again for an MPH graduate degree if they had another opportunity to do so, as well as to identify the factors influencing their decision-making process. An anonymous, web-based survey questionnaire containing 61 items was distributed to 702 MPH students in 35 universities or colleges. The questions covered the categories of student admission, training goals, lecture courses, practical training, research activities and mentorship. Levels of satisfaction were compared between MPH students who would choose MPH again as their graduate degree if they had another opportunity to do so and those who would not. Key influencing factors of training satisfaction were identified using logistic regression models. A total of 65.10% of the participants would apply again for MPH education if they had another opportunity to do so. The factors influencing students' willingness included their university type, the time since admission and their initial willingness. In addition, the four common factors (admissions & lecture courses, research activities & mentorship, practical training and training goals) emerging from factor analysis were all significantly positively correlated with student willingness (p < 0.001). Most MPH students surveyed were highly satisfied with their MPH education and, although they advocated for improvements and reforms in some aspects, they would still choose MPH as their

  19. Cost benefit analysis of 20 mph zones in London.

    PubMed

    Steinbach, Rebecca; Cairns, John; Grundy, Chris; Edwards, Phil

    2013-06-01

    Evidence suggests that 20 mph zones are an effective intervention to reduce casualties from road traffic crashes in urban areas. This analysis compares the costs of construction of the 20 mph zone intervention in high and low casualty areas in London to the value of casualties avoided over 5 and 10 year time horizons. Probabilistic sensitivity analyses were conducted to quantify uncertainty in the results associated with model parameters. Results indicate a net present value (NPV) of £18 947 (90% credible limits -£75 252 to £82 021 2005 prices) after 5 years and £67 306 (£-29 157 to £137 890) after 10 years when 20 mph zones are implemented in areas with one or more casualty per kilometre of road. Simulations from our model suggest that the 'threshold of casualties' where NPVs become positive using a 10 year time horizon is 0.7 casualties per kilometre.

  20. 47 CFR 65.104 - Page limitations for rate of return submissions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Page limitations for rate of return submissions. 65.104 Section 65.104 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERSTATE RATE OF RETURN PRESCRIPTION PROCEDURES AND METHODOLOGIES Procedures §...

  1. Operating limitations of high speed jet lubricated ball bearings

    NASA Technical Reports Server (NTRS)

    Zaretsky, E. V.; Signer, H.; Bamberger, E. N.

    1975-01-01

    A parametric study was performed with 120-mm bore angular-contact ball bearings having a nominal contact angle of 20 degrees. The bearings had either an inner- or an outer-race land riding cage, and lubrication was by recirculating oil jets which had either a single or dual orifice. Thrust load, speed, and lubricant flow rate were varied. Test results were compared with those previously reported and obtained from bearings of the same design which were under-race lubricated but run under the same conditions. Jet lubricated ball bearings were limited to speeds less than 2,500,000 DN, and bearings having inner-race land riding cages produced lower temperatures than bearings with outer-race land riding cages. For a given lubricant flow rate dual orifice jets produced lower bearing temperatures than single orifice jets, but under-race lubrication produced lower bearing temperatures under all conditions of operation with no apparent bearing speed limitation.

  2. Speed limit and ramp meter control for traffic flow networks

    NASA Astrophysics Data System (ADS)

    Goatin, Paola; Göttlich, Simone; Kolb, Oliver

    2016-07-01

    The control of traffic flow can be related to different applications. In this work, a method to manage variable speed limits combined with coordinated ramp metering within the framework of the Lighthill-Whitham-Richards (LWR) network model is introduced. Following a 'first-discretize-then-optimize' approach, the first order optimality system is derived and the switch of speeds at certain fixed points in time is explained, together with the boundary control for the ramp metering. Sequential quadratic programming methods are used to solve the control problem numerically. For application purposes, experimental setups are presented wherein variable speed limits are used as a traffic guidance system to avoid traffic jams on highway interchanges and on-ramps.

  3. 49 CFR 213.57 - Curves; elevation and speed limitations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Curves; elevation and speed limitations. 213.57 Section 213.57 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Geometry § 213.57 Curves; elevation and...

  4. 49 CFR 213.57 - Curves; elevation and speed limitations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Curves; elevation and speed limitations. 213.57 Section 213.57 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Geometry § 213.57 Curves; elevation and...

  5. Intelligent Advisory Speed Limit Dedication in Highway Using VANET

    PubMed Central

    Md Noor, Rafidah; Yeo, Hwasoo; Jung, Jason J.

    2014-01-01

    Variable speed limits (VSLs) as a mean for enhancing road traffic safety are studied for decades to modify the speed limit based on the prevailing road circumstances. In this study the pros and cons of VSL systems and their effects on traffic controlling efficiency are summarized. Despite the potential effectiveness of utilizing VSLs, we have witnessed that the effectiveness of this system is impacted by factors such as VSL control strategy used and the level of driver compliance. Hence, the proposed approach called Intelligent Advisory Speed Limit Dedication (IASLD) as the novel VSL control strategy which considers the driver compliance aims to improve the traffic flow and occupancy of vehicles in addition to amelioration of vehicle's travel times. The IASLD provides the advisory speed limit for each vehicle exclusively based on the vehicle's characteristics including the vehicle type, size, and safety capabilities as well as traffic and weather conditions. The proposed approach takes advantage of vehicular ad hoc network (VANET) to accelerate its performance, in the way that simulation results demonstrate the reduction of incident detection time up to 31.2% in comparison with traditional VSL strategy. The simulation results similarly indicate the improvement of traffic flow efficiency, occupancy, and travel time in different conditions. PMID:24999493

  6. Intelligent advisory speed limit dedication in highway using VANET.

    PubMed

    Jalooli, Ali; Shaghaghi, Erfan; Jabbarpour, Mohammad Reza; Noor, Rafidah Md; Yeo, Hwasoo; Jung, Jason J

    2014-01-01

    Variable speed limits (VSLs) as a mean for enhancing road traffic safety are studied for decades to modify the speed limit based on the prevailing road circumstances. In this study the pros and cons of VSL systems and their effects on traffic controlling efficiency are summarized. Despite the potential effectiveness of utilizing VSLs, we have witnessed that the effectiveness of this system is impacted by factors such as VSL control strategy used and the level of driver compliance. Hence, the proposed approach called Intelligent Advisory Speed Limit Dedication (IASLD) as the novel VSL control strategy which considers the driver compliance aims to improve the traffic flow and occupancy of vehicles in addition to amelioration of vehicle's travel times. The IASLD provides the advisory speed limit for each vehicle exclusively based on the vehicle's characteristics including the vehicle type, size, and safety capabilities as well as traffic and weather conditions. The proposed approach takes advantage of vehicular ad hoc network (VANET) to accelerate its performance, in the way that simulation results demonstrate the reduction of incident detection time up to 31.2% in comparison with traditional VSL strategy. The simulation results similarly indicate the improvement of traffic flow efficiency, occupancy, and travel time in different conditions.

  7. 14 CFR 25.33 - Propeller speed and pitch limits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Section 25.33 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight General § 25.33 Propeller speed and pitch limits...) The airplane stationary under standard atmospheric conditions with no wind; and (3) The...

  8. 14 CFR 25.33 - Propeller speed and pitch limits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Section 25.33 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight General § 25.33 Propeller speed and pitch limits...) The airplane stationary under standard atmospheric conditions with no wind; and (3) The...

  9. 14 CFR 25.33 - Propeller speed and pitch limits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Section 25.33 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight General § 25.33 Propeller speed and pitch limits...) The airplane stationary under standard atmospheric conditions with no wind; and (3) The...

  10. 37 CFR 10.65 - Limiting business relations with a client.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Patent and Trademark Office Code of Professional Responsibility § 10.65 Limiting business relations with... differing interests therein and if the client expects the practitioner to exercise professional judgment...

  11. 32 CFR 636.22 - Speed regulations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... (iii) The flashing, yellow, caution lights are in operation. (3) Fort Stewart housing areas, 20 miles... vehicles and will obey the following off-road driving speeds: Day Driving: Trails, 16 MPH Cross County, 6 MPH Night Driving: Trails, 5 MPH (with headlights) Cross Country, 5 MPH Night Driving: Trails, 4...

  12. 32 CFR 636.22 - Speed regulations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... (iii) The flashing, yellow, caution lights are in operation. (3) Fort Stewart housing areas, 20 miles... vehicles and will obey the following off-road driving speeds: Day Driving: Trails, 16 MPH Cross County, 6 MPH Night Driving: Trails, 5 MPH (with headlights) Cross Country, 5 MPH Night Driving: Trails, 4...

  13. 32 CFR 636.22 - Speed regulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the area. (iii) The flashing, yellow, caution lights are in operation. (3) Fort Stewart housing areas... tactical vehicles and will obey the following off-road driving speeds: Day Driving: Trails, 16 MPH Cross County, 6 MPH Night Driving: Trails, 5 MPH (with headlights) Cross Country, 5 MPH Night Driving:...

  14. High speed ultra-broadband amplitude modulators with ultrahigh extinction >65 dB

    DOE PAGES

    Liu, S.; Cai, H.; DeRose, C. T.; ...

    2017-05-04

    Here, we experimentally demonstrate ultrahigh extinction ratio (>65 dB) amplitude modulators (AMs) that can be electrically tuned to operate across a broad spectral range of 160 nm from 1480 – 1640 nm and 95 nm from 1280 – 1375 nm. Our on-chip AMs employ one extra coupler compared with conventional Mach-Zehnder interferometers (MZI), thus form a cascaded MZI (CMZI) structure. Either directional or adiabatic couplers are used to compose the CMZI AMs and experimental comparisons are made between these two different structures. Furthermore, we investigate the performance of CMZI AMs under extreme conditions such as using 95:5 split ratio couplersmore » and unbalanced waveguide losses. Electro-optic phase shifters are also integrated in the CMZI AMs for high-speed operation. Finally, we investigate the output optical phase when the amplitude is modulated, which provides us valuable information when both amplitude and phase are to be controlled. This demonstration not only paves the road to applications such as quantum information processing that requires high extinction ratio AMs but also significantly alleviates the tight fabrication tolerance needed for large-scale integrated photonics.« less

  15. Speed limits on swimming of fishes and cetaceans.

    PubMed

    Iosilevskii, G; Weihs, D

    2008-03-06

    Physical limits on swimming speed of lunate tail propelled aquatic animals are proposed. A hydrodynamic analysis, applying experimental data wherever possible, is used to show that small swimmers (roughly less than a metre long) are limited by the available power, while larger swimmers at a few metres below the water surface are limited by cavitation. Depending on the caudal fin cross-section, 10-15 m s(-1) is shown to be the maximum cavitation-free velocity for all swimmers at a shallow depth.

  16. Multimorbidity and Functional Limitations Among Adults 65 or Older, NHANES 2005-2012.

    PubMed

    Jindai, Kazuaki; Nielson, Carrie M; Vorderstrasse, Beth A; Quiñones, Ana R

    2016-11-03

    The development of functional limitations among adults aged 65 or older has profound effects on individual and population resources. Improved understanding of the relationship between functional limitations and co-occurring chronic diseases (multimorbidity) is an emerging area of interest. The objective of this study was to investigate the association between multimorbidity and functional limitations among community-dwelling adults 65 or older in the United States and explore factors that modify this association. We conducted a cross-sectional analysis of adults aged 65 or older using data from the National Health and Nutrition Examination Survey (NHANES) from 2005 through 2012. We used negative binomial regression to estimate the association between multimorbidity (≥2 concurrent diseases) and functional limitations and to determine whether the association differed by sex or age. The prevalence of multimorbidity in this population was 67% (95% confidence interval [CI], 65%-68%). Each additional chronic condition was associated with an increase in the number of functional limitations, and the association was stronger among those aged 75 or older than among those aged 65 to 74. For those aged 65 to 74, each additional chronic condition was associated with 1.35 (95% CI, 1.27-1.43) times the number of functional limitations for men and 1.62 times (95% CI, 1.31-2.02) the number of functional limitations for women. For those 75 or older, the associations increased to 1.71 (95% CI, 1.35-2.16) for men and 2.06 (95% CI, 1.51-2.81) for women for each additional chronic condition. Multimorbidity was associated with increases in functional limitations, and the associations were stronger among women than among men and among adults aged 75 or older than among those aged 65 to 74. These findings underscore the importance of addressing age and sex differences when formulating prevention strategies.

  17. Multimorbidity and Functional Limitations Among Adults 65 or Older, NHANES 2005–2012

    PubMed Central

    Jindai, Kazuaki; Nielson, Carrie M.; Vorderstrasse, Beth A.

    2016-01-01

    Introduction The development of functional limitations among adults aged 65 or older has profound effects on individual and population resources. Improved understanding of the relationship between functional limitations and co-occurring chronic diseases (multimorbidity) is an emerging area of interest. The objective of this study was to investigate the association between multimorbidity and functional limitations among community-dwelling adults 65 or older in the United States and explore factors that modify this association. Methods We conducted a cross-sectional analysis of adults aged 65 or older using data from the National Health and Nutrition Examination Survey (NHANES) from 2005 through 2012. We used negative binomial regression to estimate the association between multimorbidity (≥2 concurrent diseases) and functional limitations and to determine whether the association differed by sex or age. Results The prevalence of multimorbidity in this population was 67% (95% confidence interval [CI], 65%–68%). Each additional chronic condition was associated with an increase in the number of functional limitations, and the association was stronger among those aged 75 or older than among those aged 65 to 74. For those aged 65 to 74, each additional chronic condition was associated with 1.35 (95% CI, 1.27–1.43) times the number of functional limitations for men and 1.62 times (95% CI, 1.31–2.02) the number of functional limitations for women. For those 75 or older, the associations increased to 1.71 (95% CI, 1.35–2.16) for men and 2.06 (95% CI, 1.51–2.81) for women for each additional chronic condition. Conclusion Multimorbidity was associated with increases in functional limitations, and the associations were stronger among women than among men and among adults aged 75 or older than among those aged 65 to 74. These findings underscore the importance of addressing age and sex differences when formulating prevention strategies. PMID:27809419

  18. Blazar Jets Push Closer to Cosmic Speed Limit

    NASA Astrophysics Data System (ADS)

    2005-01-01

    Astronomers using the National Science Foundation's Very Long Baseline Array (VLBA) have discovered jets of plasma blasted from the cores of distant galaxies at speeds within one-tenth of one percent of the speed of light, placing these plasma jets among the fastest objects yet seen in the Universe. "This tells us that the physical processes at the cores of these galaxies, called blazars, are extremely energetic and are capable of propelling matter very close to the absolute cosmic speed limit," said Glenn Piner of Whittier College in Whittier, California. Piner, who worked on the project with student Dipesh Bhattari, also of Whittier College, Philip Edwards of the Japan Aerospace Exploration Agency, and Dayton Jones of NASA's Jet Propulsion Laboratory, presented their findings to the American Astronomical Society's meeting in San Diego, California. According to Einstein's Special Theory of Relativity, no object with mass can be accelerated to the speed of light. To get even close to the speed of light requires enormous amounts of energy. "For example, to accelerate a bowling ball to the speed newly measured in these blazars would require all the energy produced in the world for an entire week," Piner said, "and the blobs of plasma in these jets are at least as massive as a large planet". Blazars are active galactic nuclei -- energetic regions surrounding massive black holes at the centers of galaxies. Material being drawn into the black hole forms a spinning disk called an accretion disk. Powerful jets of charged particles are ejected at high speeds along the poles of accretion disks. When these jets happen to be aimed nearly toward the Earth, the objects are called blazars. Taking advantage of the extremely sharp radio "vision" of the continent-wide VLBA, the scientists tracked individual features in the jets of three blazars at distances from Earth ranging from 7.3 to 9 billion light-years. A Boston University team led by Svetlana Jorstad earlier had identified

  19. Speed and efficiency limits of multilevel incoherent heat engines

    NASA Astrophysics Data System (ADS)

    Mukherjee, V.; Niedenzu, W.; Kofman, A. G.; Kurizki, G.

    2016-12-01

    We present a comprehensive theory of heat engines (HE) based on a quantum-mechanical "working fluid" (WF) with periodically modulated energy levels. The theory is valid for any periodicity of driving Hamiltonians that commute with themselves at all times and do not induce coherence in the WF. Continuous and stroke cycles arise in opposite limits of this theory, which encompasses hitherto unfamiliar cycle forms, dubbed here hybrid cycles. The theory allows us to discover the speed, power, and efficiency limits attainable by incoherently operating multilevel HE depending on the cycle form and the dynamical regimes.

  20. 77 FR 37470 - Technical Standard Order (TSO)-C65a, Airborne Doppler Radar Ground Speed and/or Drift Angle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-21

    ... Federal Aviation Administration Technical Standard Order (TSO)-C65a, Airborne Doppler Radar Ground Speed... Doppler radar ground speed and/or drift angle measuring equipment (for air carrier aircraft). SUMMARY: This notice announces the FAA's intent to cancel TSO-C65a, Airborne Doppler radar ground speed and/or...

  1. Are Students Aware of the Speed Limits on a University Campus?

    ERIC Educational Resources Information Center

    Brooks, Johnell; Raines, Stephanie; Klein, Nathan; Crisler, Matt; Wills, Rebekkah; Mossey, Mary; Koon, Beatrice; McKibben, Eric; Ogle, Jennifer; Robinson, Geary

    2010-01-01

    Driving speed is an important traffic safety issue. The lack of adherence to posted speed limits is a safety concern, especially on university campuses where the populations of drivers are at increased risk for crashes involving speeding due to their young age. Thus, driver speed and knowledge of speed limits on university campuses is an important…

  2. Are Students Aware of the Speed Limits on a University Campus?

    ERIC Educational Resources Information Center

    Brooks, Johnell; Raines, Stephanie; Klein, Nathan; Crisler, Matt; Wills, Rebekkah; Mossey, Mary; Koon, Beatrice; McKibben, Eric; Ogle, Jennifer; Robinson, Geary

    2010-01-01

    Driving speed is an important traffic safety issue. The lack of adherence to posted speed limits is a safety concern, especially on university campuses where the populations of drivers are at increased risk for crashes involving speeding due to their young age. Thus, driver speed and knowledge of speed limits on university campuses is an important…

  3. 14 CFR 29.33 - Main rotor speed and pitch limits.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Main rotor speed and pitch limits. 29.33... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight General § 29.33 Main rotor speed and pitch limits. (a) Main rotor speed limits. A range of main rotor speeds must be established that— (1) With power on...

  4. 14 CFR 27.33 - Main rotor speed and pitch limits.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main rotor speed and pitch limits. 27.33... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight General § 27.33 Main rotor speed and pitch limits. (a) Main rotor speed limits. A range of main rotor speeds must be established that— (1) With power on...

  5. 14 CFR 27.33 - Main rotor speed and pitch limits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Main rotor speed and pitch limits. 27.33... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight General § 27.33 Main rotor speed and pitch limits. (a) Main rotor speed limits. A range of main rotor speeds must be established that— (1) With power on...

  6. 14 CFR 27.33 - Main rotor speed and pitch limits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Main rotor speed and pitch limits. 27.33... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight General § 27.33 Main rotor speed and pitch limits. (a) Main rotor speed limits. A range of main rotor speeds must be established that— (1) With power on...

  7. 14 CFR 27.33 - Main rotor speed and pitch limits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main rotor speed and pitch limits. 27.33... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight General § 27.33 Main rotor speed and pitch limits. (a) Main rotor speed limits. A range of main rotor speeds must be established that— (1) With power on...

  8. 14 CFR 29.33 - Main rotor speed and pitch limits.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main rotor speed and pitch limits. 29.33... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight General § 29.33 Main rotor speed and pitch limits. (a) Main rotor speed limits. A range of main rotor speeds must be established that— (1) With power on...

  9. 14 CFR 29.33 - Main rotor speed and pitch limits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Main rotor speed and pitch limits. 29.33... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight General § 29.33 Main rotor speed and pitch limits. (a) Main rotor speed limits. A range of main rotor speeds must be established that— (1) With power on...

  10. 14 CFR 27.33 - Main rotor speed and pitch limits.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Main rotor speed and pitch limits. 27.33... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight General § 27.33 Main rotor speed and pitch limits. (a) Main rotor speed limits. A range of main rotor speeds must be established that— (1) With power on...

  11. 14 CFR 29.33 - Main rotor speed and pitch limits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main rotor speed and pitch limits. 29.33... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight General § 29.33 Main rotor speed and pitch limits. (a) Main rotor speed limits. A range of main rotor speeds must be established that— (1) With power on...

  12. 14 CFR 29.33 - Main rotor speed and pitch limits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Main rotor speed and pitch limits. 29.33... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight General § 29.33 Main rotor speed and pitch limits. (a) Main rotor speed limits. A range of main rotor speeds must be established that— (1) With power on...

  13. The cost-effectiveness of mandatory 20 mph zones for the prevention of injuries.

    PubMed

    Peters, Jaime L; Anderson, Rob

    2013-03-01

    Traffic calming and speed limits are major public health strategies for further reducing road injuries, especially for vulnerable pedestrians such as children and the elderly. We conducted a cost-benefit analysis (CBA-favoured by transport economists) alongside a cost-utility analysis (CUA-favoured by health economists) of mandatory 20 mph zones, providing a unique opportunity to compare assumptions and results. A CUA from the public sector perspective and a CBA from a broader societal perspective. One-way, threshold and probabilistic sensitivity analyses were undertaken. In low casualty areas the intervention was not cost-effective regardless of approach (CUA: cost per QALY = £429 800; CBA: net present value = -£25 500). In high casualty areas, the intervention was cost-effective from the CBA (a saving of £90 600), but not from the CUA [cost per quality-adjusted life year (QALY) = £86 500; assuming National Institute for Health and Clinical Excellence's benchmark for approving health technologies]. Mandatory 20 mph zones may be cost-effective in high casualty areas when a CBA from a societal perspective is considered. Although CBA may appear, in principle, more appropriate, the quality, age or absence of reliable data for many parameters means that there is a great deal of uncertainty and the results should be interpreted with caution.

  14. Raising the Speed Limit for β-Hairpin Formation

    PubMed Central

    Davis, Caitlin M.; Xiao, Shifeng; Raleigh, Daniel P.; Dyer, R. Brian

    2012-01-01

    Understanding the folding of the β-hairpin is a crucial step in studying how β-rich proteins fold. We have studied CLN025, an optimized ten residue synthetic peptide, which adopts a compact, well-structured β-hairpin conformation. Formation of the component β-sheet and β-turn structures of CLN025 was probed independently using a combination of equilibrium Fourier transform infrared spectroscopy and laser-induced temperature jump coupled with time-resolved infrared and fluorescence spectroscopies. We find that CLN025 is an ultrafast folder due to its small free energy barrier to folding and that it exceeds the predicted speed limit for β-hairpin formation by an order of magnitude. We also find that the folding mechanism cannot be described by a simple two-state model, but rather is a heterogeneous process involving two independent parallel processes. Formation of stabilizing cross-strand hydrophobic interactions and turn alignment occur competitively, with relaxation lifetimes of 82 ± 10 and 124 ± 10 ns, respectively, at the highest probed temperature. The ultrafast and heterogeneous folding kinetics observed for CLN025 provide evidence for folding on a nearly barrierless free energy landscape, and recalibrate the speed limit for the formation of a β-hairpin. PMID:22873643

  15. Speed-limited particle-in-cell (SLPIC) simulation

    NASA Astrophysics Data System (ADS)

    Werner, Gregory; Cary, John; Jenkins, Thomas

    2016-10-01

    Speed-limited particle-in-cell (SLPIC) simulation is a new method for particle-based plasma simulation that allows increased timesteps in cases where the timestep is determined (e.g., in standard PIC) not by the smallest timescale of interest, but rather by an even smaller physical timescale that affects numerical stability. For example, SLPIC need not resolve the plasma frequency if plasma oscillations do not play a significant role in the simulation; in contrast, standard PIC must usually resolve the plasma frequency to avoid instability. Unlike fluid approaches, SLPIC retains a fully-kinetic description of plasma particles and includes all the same physical phenomena as PIC; in fact, if SLPIC is run with a PIC-compatible timestep, it is identical to PIC. However, unlike PIC, SLPIC can run stably with larger timesteps. SLPIC has been shown to be effective for finding steady-state solutions for 1D collisionless sheath problems, greatly speeding up computation despite a large ion/electron mass ratio. SLPIC is a relatively small modification of standard PIC, with no complexities that might degrade parallel efficiency (compared to PIC), and is similarly compatible with PIC field solvers and boundary conditions.

  16. Evolutionary speed limited by water in arid Australia

    PubMed Central

    Goldie, Xavier; Gillman, Len; Crisp, Mike; Wright, Shane

    2010-01-01

    The covariation of biodiversity with climate is a fundamental pattern in nature. However, despite the ubiquity of this relationship, a consensus on the ultimate cause remains elusive. The evolutionary speed hypothesis posits direct mechanistic links between ambient temperature, the tempo of micro-evolution and, ultimately, species richness. Previous research has demonstrated faster rates of molecular evolution in warmer climates for a broad range of poikilothermic and homeothermic organisms, in both terrestrial and aquatic environments. In terrestrial systems, species richness increases with both temperature and water availability and the interaction of those terms: productivity. However, the influence of water availability as an independent variable on micro-evolutionary processes has not been examined previously. Here, using methodology that limits the potentially confounding role of cladogenetic and demographic processes, we report, to our knowledge, the first evidence that woody plants living in the arid Australian Outback are evolving more slowly than related species growing at similar latitudes in moist habitats on the mesic continental margins. These results support a modified evolutionary speed explanation for the relationship between the water-energy balance and plant diversity patterns. PMID:20410038

  17. Evaluating the safety impact of increased speed limits on rural highways in British Columbia.

    PubMed

    Sayed, Tarek; Sacchi, Emanuele

    2016-10-01

    Maximum speed limits are usually set to inform drivers of the highest speed that it is safe and appropriate for ideal traffic, road and weather conditions. Many previous studies were conducted to investigate the relationship between changed speed limits and safety. The results of these studies generally show that relaxing speed limits can negatively affect safety, especially with regard to fatal and injury crashes. Despite these results, several road jurisdictions in North America continue to raise the maximum speed limits. In 2013, the British Columbia Ministry of Transportation and Infrastructure initiated a speed limits review. The review found that the 85th percentile speed on many highway segments was 10km/h higher than corresponding posted speed limits and 1300km of rural provincial highway segments were recommended for higher speed limits. Most of the highway segments had 10km/h speed limit increase with a small section having 20km/h speed limit increase. As speed limit changes can have a substantial impact on safety, the main objective of this study is to estimate the effect of the increased speed limits on crash occurrence. A before-after evaluation was undertaken with the full Bayesian technique. Overall, the evaluation showed that changed speed limits led to a statistically significant increase in fatal-plus-injury (severe) crashes of 11.1%. A crash modification function that includes changes in the treatment effect over time showed that the initial increase of the first post-implementation period may slightly decrease over time.

  18. Scalar speed limits and cosmology: Acceleration from D-cceleration

    NASA Astrophysics Data System (ADS)

    Silverstein, Eva; Tong, David

    2004-11-01

    Causality on the gravity side of the AdS/CFT correspondence restricts motion on the moduli space of the N=4 super Yang-Mills theory by imposing a speed limit on how fast the scalar field may roll. This effect can be traced to higher-derivative operators arising from integrating out light degrees of freedom near the origin. In the strong coupling limit of the theory, the dynamics is well approximated by the Dirac-Born-Infeld Lagrangian for a probe D3-brane moving toward the horizon of the AdS Poincaré patch, combined with an estimate of the (ultimately suppressed) rate of particle and string production in the system. We analyze the motion of a rolling scalar field explicitly in the strong coupling regime of the field theory and extend the analysis to cosmological systems obtained by coupling this type of field theory to four-dimensional gravity. This leads to a mechanism for slow roll inflation for a massive scalar at sub-Planckian vacuum expectation value without need for a flat potential (realizing a version of k inflation in a microphysical framework). It also leads to a variety of novel Friedman-Roberston-Walker cosmologies, some of which are related to those obtained with tachyon matter.

  19. Scalar Speed Limits and Cosmology: Acceleration from Deceleration

    SciTech Connect

    Silverstein, E

    2003-11-21

    Causality on the gravity side of the AdS/CFT correspondence restricts motion on the moduli space of the N = 4 super Yang Mills theory by imposing a speed limit on how fast the scalar field may roll. This effect can be traced to higher derivative operators arising from integrating out light degrees of freedom near the origin. In the strong coupling limit of the theory, the dynamics is well approximated by the Dirac-Born-Infeld Lagrangian for a probe D3-brane moving toward the horizon of the AdS Poincare patch, combined with an estimate of the (ultimately suppressed) rate of particle and string production in the system. We analyze the motion of a rolling scalar field explicitly in the strong coupling regime of the field theory, and extend the analysis to cosmological systems obtained by coupling this type of field theory to four dimensional gravity. This leads to a mechanism for slow roll inflation for a massive scalar at subPlanckian VEV without need for a flat potential (realizing a version of k-inflation in a microphysical framework). It also leads to a variety of novel FRW cosmologies, some of which are related to those obtained with tachyon matter.

  20. Balance impairment limits ability to increase walking speed in individuals with chronic stroke.

    PubMed

    Middleton, Addie; Braun, Carty H; Lewek, Michael D; Fritz, Stacy L

    2017-03-01

    Purpose Determine the relationship between balance impairments and the ability to increase walking speed (WS) on demand in individuals with chronic stroke. Methods WS and Berg Balance Scale (BBS) data were collected on 124 individuals with chronic stroke (>6 months). The ability to increase WS on demand (walking speed reserve, WSR) was quantified as the difference between participants' self-selected (SSWS) and maximal (MWS) walking speeds. Correlation, regression and receiver operating characteristic (ROC) analyses were performed to investigate the relationship between balance and the ability to increase WS. Results Of sample, 58.9% were unable to increase WS on demand (WSR < 0.2 m/s). BBS scores were associated with WSR values (rs=0.74, 0.65-0.81) and were predictive of 'able/unable' to increase WS [odds ratio (OR) = 0.75, 0.67-0.84]. The AUC for the ROC curve constructed to assess the accuracy of BBS to discriminate between able/unable to increase WS was 0.85 (0.78-0.92). A BBS cutscore of 47 points was identified [sensitivity: 72.6%, specificity: 90.2%, +likelihood ratio (LR): 7.41, -LR: 0.30]. Conclusions The inability to increase WS on demand is common in individuals with chronic stroke, and balance appears to be a significant contributor to this difficulty. A BBS cutscore of 47 points can identify individuals who may benefit from balance interventions to improve the ability to increase their WS. Implications for Rehabilitation A majority of individuals with chronic stroke may be unable to increase their walking speed beyond their self-selected speed on demand. This may limit functional ambulation, as these individuals are walking "at capacity". Balance impairments contribute to the inability to increase walking speed. A Berg Balance Scale score <47 points can be used to identify individuals with chronic stroke walking "at capacity" due to balance impairments.

  1. Summary Report on the High-Speed Characteristics of Six Model Wings Having NACA 65sub1-Series Sections

    NASA Technical Reports Server (NTRS)

    Hamilton, William T; Nelson, Warren H

    1947-01-01

    A summary of the results of wind-tunnel tests to determine the high-speed aerodynamic characteristics of six model wings having NACA 65sub1-series sections is presented in this report. The 8-percent-thick wings were superior to the 10-percent and 12-percent-thick wings from the standpoint of power economy during level flight for Mach numbers above 0.76. However, airplanes that are to fly at Mach numbers below 0.76 will gain aerodynamically if the percentage thickness of the wing and the aspect ratio are both increased. The lift-curve slopes for the 8-percent-thick wings at 0.85 Mach number were roughly twice their low-speed values.

  2. Quantum speed limit and a signal of quantum criticality

    PubMed Central

    Wei, Yong-Bo; Zou, Jian; Wang, Zhao-Ming; Shao, Bin

    2016-01-01

    We study the quantum speed limit time (QSLT) of a coupled system consisting of a central spin and its surrounding environment, and the environment is described by a general XY spin-chain model. For initial pure state, we find that the local anomalous enhancement of the QSLT occurs near the critical point. In addition, we investigate the QSLT for arbitrary time-evolution state in the whole dynamics process and find that the QSLT will decay monotonously and rapidly at a large size of environment near the quantum critical point. These anomalous behaviors in the critical vicinity of XY spin-chain environment can be used to indicate the quantum phase transition point. Especially for the XX spin-chain environment, we find that the QSLT displays a sudden transition from discontinuous segmented values to a steady value at the critical point. In this case, the non-Makovianity and the Loschmidt echo are incapable of signaling the critical value of the transverse field, while the QSLT can still witness the quantum phase transition. So, the QSLT provides a further insight and sharper identification of quantum criticality. PMID:26782296

  3. Evaluation of automated speed enforcement in Montgomery County, Maryland.

    PubMed

    Retting, Richard A; Farmer, Charles M; McCartt, Anne T

    2008-10-01

    Almost one quarter of speeding-related fatalities occur on streets with speed limits of 35 mph or less. In 2007, Montgomery County, Maryland, implemented the state's first automated speed enforcement program, with camera use limited to residential streets with speeds limits of 35 mph or less and school zones. The purpose of the present study was to evaluate initial effects of camera enforcement on traffic speeds and to assess public attitudes. Vehicle speeds were measured approximately 6 months before and 6 months after speed cameras were deployed and warning signs were installed. Speed data were collected on a sample of roads with and without camera enforcement in Montgomery County, as well as on a sample of roads in a comparison community that did not have speed cameras. In addition, telephone surveys were conducted in Montgomery County. Relative to speeds of drivers on roads in the comparison community, the proportion of drivers in Montgomery County traveling more than 10 mph above posted speed limits declined by about 70% at locations with both warning signs and speed camera enforcement, 39% at locations with warning signs but no speed cameras, and 16% on residential streets with neither warning signs nor speed cameras. Public opinion surveys found 74% of Montgomery County drivers thought speeding on residential streets was a problem. Six months after enforcement began, 60% of drivers were aware of the camera program and 62% supported it. The camera program was effective at reducing speeding on targeted streets. The finding of speed reductions beyond targeted locations is evidence that highly visible automated enforcement can promote community-wide changes in driver behavior. Although a majority of drivers supported automated speed enforcement, about one third opposed it. Jurisdictions planning to implement speed cameras should draw on international experience to anticipate controversies that generally arise and take steps to address them.

  4. 49 CFR 392.6 - Schedules to conform with speed limits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Schedules to conform with speed limits. 392.6... DRIVING OF COMMERCIAL MOTOR VEHICLES General § 392.6 Schedules to conform with speed limits. No motor... points in such period of time as would necessitate the commercial motor vehicle being operated at speeds...

  5. 49 CFR 392.6 - Schedules to conform with speed limits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Schedules to conform with speed limits. 392.6... DRIVING OF COMMERCIAL MOTOR VEHICLES General § 392.6 Schedules to conform with speed limits. No motor... points in such period of time as would necessitate the commercial motor vehicle being operated at speeds...

  6. 49 CFR 392.6 - Schedules to conform with speed limits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Schedules to conform with speed limits. 392.6... DRIVING OF COMMERCIAL MOTOR VEHICLES General § 392.6 Schedules to conform with speed limits. No motor... points in such period of time as would necessitate the commercial motor vehicle being operated at speeds...

  7. 49 CFR 392.6 - Schedules to conform with speed limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Schedules to conform with speed limits. 392.6... DRIVING OF COMMERCIAL MOTOR VEHICLES General § 392.6 Schedules to conform with speed limits. No motor... points in such period of time as would necessitate the commercial motor vehicle being operated at speeds...

  8. 49 CFR 392.6 - Schedules to conform with speed limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Schedules to conform with speed limits. 392.6... DRIVING OF COMMERCIAL MOTOR VEHICLES General § 392.6 Schedules to conform with speed limits. No motor... points in such period of time as would necessitate the commercial motor vehicle being operated at speeds...

  9. Exploring the quantum speed limit with computer games

    NASA Astrophysics Data System (ADS)

    Sørensen, Jens Jakob W. H.; Pedersen, Mads Kock; Munch, Michael; Haikka, Pinja; Jensen, Jesper Halkjær; Planke, Tilo; Andreasen, Morten Ginnerup; Gajdacz, Miroslav; Mølmer, Klaus; Lieberoth, Andreas; Sherson, Jacob F.

    2016-04-01

    Humans routinely solve problems of immense computational complexity by intuitively forming simple, low-dimensional heuristic strategies. Citizen science (or crowd sourcing) is a way of exploiting this ability by presenting scientific research problems to non-experts. ‘Gamification’—the application of game elements in a non-game context—is an effective tool with which to enable citizen scientists to provide solutions to research problems. The citizen science games Foldit, EteRNA and EyeWire have been used successfully to study protein and RNA folding and neuron mapping, but so far gamification has not been applied to problems in quantum physics. Here we report on Quantum Moves, an online platform gamifying optimization problems in quantum physics. We show that human players are able to find solutions to difficult problems associated with the task of quantum computing. Players succeed where purely numerical optimization fails, and analyses of their solutions provide insights into the problem of optimization of a more profound and general nature. Using player strategies, we have thus developed a few-parameter heuristic optimization method that efficiently outperforms the most prominent established numerical methods. The numerical complexity associated with time-optimal solutions increases for shorter process durations. To understand this better, we produced a low-dimensional rendering of the optimization landscape. This rendering reveals why traditional optimization methods fail near the quantum speed limit (that is, the shortest process duration with perfect fidelity). Combined analyses of optimization landscapes and heuristic solution strategies may benefit wider classes of optimization problems in quantum physics and beyond.

  10. Exploring the quantum speed limit with computer games.

    PubMed

    Sørensen, Jens Jakob W H; Pedersen, Mads Kock; Munch, Michael; Haikka, Pinja; Jensen, Jesper Halkjær; Planke, Tilo; Andreasen, Morten Ginnerup; Gajdacz, Miroslav; Mølmer, Klaus; Lieberoth, Andreas; Sherson, Jacob F

    2016-04-14

    Humans routinely solve problems of immense computational complexity by intuitively forming simple, low-dimensional heuristic strategies. Citizen science (or crowd sourcing) is a way of exploiting this ability by presenting scientific research problems to non-experts. 'Gamification'--the application of game elements in a non-game context--is an effective tool with which to enable citizen scientists to provide solutions to research problems. The citizen science games Foldit, EteRNA and EyeWire have been used successfully to study protein and RNA folding and neuron mapping, but so far gamification has not been applied to problems in quantum physics. Here we report on Quantum Moves, an online platform gamifying optimization problems in quantum physics. We show that human players are able to find solutions to difficult problems associated with the task of quantum computing. Players succeed where purely numerical optimization fails, and analyses of their solutions provide insights into the problem of optimization of a more profound and general nature. Using player strategies, we have thus developed a few-parameter heuristic optimization method that efficiently outperforms the most prominent established numerical methods. The numerical complexity associated with time-optimal solutions increases for shorter process durations. To understand this better, we produced a low-dimensional rendering of the optimization landscape. This rendering reveals why traditional optimization methods fail near the quantum speed limit (that is, the shortest process duration with perfect fidelity). Combined analyses of optimization landscapes and heuristic solution strategies may benefit wider classes of optimization problems in quantum physics and beyond.

  11. Teaching public health practitioners about health communication: the MPH curriculum experience.

    PubMed

    Hoffman-Goetz, L; Dwiggins, S

    1998-04-01

    The dissemination of health information to the public often occurs through the mass media. Media strategies as a component of behavior change assume knowledge of communication theories and methods by public health practitioners. We surveyed the curricula of 52 accredited graduate programs leading to the Master's in Public Health (MPH) degree to assess their communication component. Graduate bulletins for admission year 1996 were examined for public health mission statement, goals and objectives of the MPH training program, and for course titles. Courses were identified as having a communication focus if the terms communication, information, marketing or media were used in the title. There were a total of 82 communication courses offered, with 65 courses in 26 Schools of Public Health (SPH), 13 courses in 18 Community Health and Preventive Medicine departments (CHPM), and 4 courses in 8 Community Health Education departments (CHE). The difference in mean number of health communication courses was significant by type of MPH program (p < 0.003) with SPH offering an average of 3 courses, CHPM departments offering an average of 1 course, and CHE offering an average of 0.5 course. The distribution of communication courses ranged from 10 courses to 0 courses per program. Seven SPH offered 3 or more communication courses, whereas 5 SPH offered no health communication courses in the MPH curriculum. These data point to a shortcoming in the training of MPH students in health communication theory and skills as ascertained by course titles in graduate bulletins.

  12. LETTERS AND COMMENTS: An elementary first-postulate measurement of the cosmic limit speed

    NASA Astrophysics Data System (ADS)

    Coleman, Brian

    2004-05-01

    In 1898 Henri Poincaré referred to the speed of light as a probable limit speed but rashly asserted it would never as such be experimentally verifiable. Moving space vehicle measurements of the cosmic limit speed, however, without assuming it equals c, were described by Coleman (2003 Eur. J. Phys. 24 301). A more elementary measurement is also possible, involving two mutually stationary vehicles with a third passing between them. A simple formula gives the limit speed in terms of signal speed c and three time intervals.

  13. Single software platform used for high speed data transfer implementation in a 65k pixel camera working in single photon counting mode

    NASA Astrophysics Data System (ADS)

    Maj, P.; Kasiński, K.; Gryboś, P.; Szczygieł, R.; Kozioł, A.

    2015-12-01

    Integrated circuits designed for specific applications generally use non-standard communication methods. Hybrid pixel detector readout electronics produces a huge amount of data as a result of number of frames per seconds. The data needs to be transmitted to a higher level system without limiting the ASIC's capabilities. Nowadays, the Camera Link interface is still one of the fastest communication methods, allowing transmission speeds up to 800 MB/s. In order to communicate between a higher level system and the ASIC with a dedicated protocol, an FPGA with dedicated code is required. The configuration data is received from the PC and written to the ASIC. At the same time, the same FPGA should be able to transmit the data from the ASIC to the PC at the very high speed. The camera should be an embedded system enabling autonomous operation and self-monitoring. In the presented solution, at least three different hardware platforms are used—FPGA, microprocessor with real-time operating system and the PC with end-user software. We present the use of a single software platform for high speed data transfer from 65k pixel camera to the personal computer.

  14. 77 FR 53962 - Technical Standard Order (TSO)-C65a, Airborne Doppler Radar Ground Speed and/or Drift Angle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-04

    ... TRANSPORTATION Federal Aviation Administration Technical Standard Order (TSO)-C65a, Airborne Doppler Radar Ground... Doppler Radar Ground Speed and/or Drift Angle Measuring Equipment (For Air Carrier Aircraft). SUMMARY... INFORMATION: Background The Doppler radar ground speed and/or drift angle measuring equipment described by...

  15. Traffic management: Assessing various countermeasures to improve detection failure of changes in speed limit signals.

    PubMed

    Harms, Ilse M; Brookhuis, Karel A

    2017-05-01

    Under certain circumstances, drivers fail to notice changes in electronic speed limits. A video-based study was performed to reveal which countermeasures would improve drivers' ability to detect changes in electronic speed limits. Countermeasures included leaving electronic signs blank prior to a speed limit change and adding motion signals by means of flashing amber lights or a wave. A video representing a motorway was shown repeatedly to 255 participants. They were instructed to press the space bar when detecting a change. The video was viewed 13 times before the speed limit changed. Results showed that leaving signs blank prior to the change instead of displaying speed limits continuously did not alter change detection, whereas flashers and waves eroded detection of the changed speed limit. This suggests that using flashers and waves to attract attention to electronic signs in fact decreases people's ability to process the information contained in the signs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Yeast Mph1 helicase dissociates Rad51-made D-loops: implications for crossover control in mitotic recombination.

    PubMed

    Prakash, Rohit; Satory, Dominik; Dray, Eloïse; Papusha, Almas; Scheller, Jürgen; Kramer, Wilfried; Krejci, Lumir; Klein, Hannah; Haber, James E; Sung, Patrick; Ira, Grzegorz

    2009-01-01

    Eukaryotes possess mechanisms to limit crossing over during homologous recombination, thus avoiding possible chromosomal rearrangements. We show here that budding yeast Mph1, an ortholog of human FancM helicase, utilizes its helicase activity to suppress spontaneous unequal sister chromatid exchanges and DNA double-strand break-induced chromosome crossovers. Since the efficiency and kinetics of break repair are unaffected, Mph1 appears to channel repair intermediates into a noncrossover pathway. Importantly, Mph1 works independently of two other helicases-Srs2 and Sgs1-that also attenuate crossing over. By chromatin immunoprecipitation, we find targeting of Mph1 to double-strand breaks in cells. Purified Mph1 binds D-loop structures and is particularly adept at unwinding these structures. Importantly, Mph1, but not a helicase-defective variant, dissociates Rad51-made D-loops. Overall, the results from our analyses suggest a new role of Mph1 in promoting the noncrossover repair of DNA double-strand breaks.

  17. Pushing the speed limit in enantioselective supercritical fluid chromatography.

    PubMed

    Regalado, Erik L; Welch, Christopher J

    2015-08-01

    Chromatographic enantioseparations on the order of a few seconds can be achieved by supercritical fluid chromatography using short columns packed with chiral stationary phases. The evolution of 'world record' speeds for the chromatographic separation of enantiomers has steadily dropped from an industry standard of 20-40 min just two decades ago, to a current ability to perform many enantioseparations in well under a minute. Improvements in instrument and column technologies enabled this revolution, but the ability to predict optimal separation time from an initial method development screening assay using the t(min cc) predictor greatly simplifies the development and optimization of high-speed chiral chromatographic separations. In this study, we illustrate how the use of this simple tool in combination with the workhorse technique of supercritical fluid chromatography on customized short chiral columns (1-2 cm length) allows us to achieve ultrafast enantioseparations of pharmaceutically relevant compounds on the 5-20 s scale, bringing the technique of high-throughput enantiopurity analysis out of the specialist realm and into the laboratories of most researchers.

  18. 49 CFR 213.9 - Classes of track: operating speed limits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Classes of track: operating speed limits. 213.9... speed limits. (a) Except as provided in paragraph (b) of this section and §§ 213.57(b), 213.59(a), 213.113(a), and 213.137(b) and (c), the following maximum allowable operating speeds apply— Over track...

  19. 49 CFR 213.9 - Classes of track: operating speed limits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Classes of track: operating speed limits. 213.9... speed limits. (a) Except as provided in paragraph (b) of this section and §§ 213.57(b), 213.59(a), 213.113(a), and 213.137(b) and (c), the following maximum allowable operating speeds apply— [In miles per...

  20. 49 CFR 213.9 - Classes of track: operating speed limits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Classes of track: operating speed limits. 213.9... speed limits. (a) Except as provided in paragraph (b) of this section and §§ 213.57(b), 213.59(a), 213.113(a), and 213.137(b) and (c), the following maximum allowable operating speeds apply— [In miles per...

  1. 49 CFR 213.9 - Classes of track: operating speed limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Classes of track: operating speed limits. 213.9... speed limits. (a) Except as provided in paragraph (b) of this section and §§ 213.57(b), 213.59(a), 213.113(a), and 213.137(b) and (c), the following maximum allowable operating speeds apply— Over track...

  2. 49 CFR 213.9 - Classes of track: operating speed limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Classes of track: operating speed limits. 213.9... speed limits. (a) Except as provided in paragraph (b) of this section and §§ 213.57(b), 213.59(a), 213.113(a), and 213.137(b) and (c), the following maximum allowable operating speeds apply— [In miles per...

  3. 28 CFR 65.11 - Limitations on fund and other assistance use.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... directly and substantially upon criminal justice matters or are inextricably intertwined with criminal..., supervision, or control over any police force or other criminal justice agency of an applicant for Federal law... use. 65.11 Section 65.11 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMERGENCY FEDERAL...

  4. 28 CFR 65.11 - Limitations on fund and other assistance use.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... directly and substantially upon criminal justice matters or are inextricably intertwined with criminal..., supervision, or control over any police force or other criminal justice agency of an applicant for Federal law... use. 65.11 Section 65.11 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMERGENCY FEDERAL...

  5. 28 CFR 65.11 - Limitations on fund and other assistance use.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... directly and substantially upon criminal justice matters or are inextricably intertwined with criminal..., supervision, or control over any police force or other criminal justice agency of an applicant for Federal law... use. 65.11 Section 65.11 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMERGENCY FEDERAL...

  6. 28 CFR 65.11 - Limitations on fund and other assistance use.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... directly and substantially upon criminal justice matters or are inextricably intertwined with criminal..., supervision, or control over any police force or other criminal justice agency of an applicant for Federal law... use. 65.11 Section 65.11 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMERGENCY FEDERAL...

  7. 28 CFR 65.11 - Limitations on fund and other assistance use.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... directly and substantially upon criminal justice matters or are inextricably intertwined with criminal..., supervision, or control over any police force or other criminal justice agency of an applicant for Federal law... use. 65.11 Section 65.11 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMERGENCY FEDERAL...

  8. Traffic accidents in a cellular automaton model with a speed limit zone

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Yang, Xian-qing; Sun, Da-peng; Qiu, Kang; Xia, Hui

    2006-07-01

    In this paper, we numerically study the probability Pac of the occurrence of car accidents in the Nagel-Schreckenberg (NS) model with a speed limit zone. Numerical results show that the probability for car accidents to occur Pac is determined by the maximum speed v'max of the speed limit zone, but is independent of the length Lv of the speed limit zone in the deterministic NS model. However in the nondeterministic NS model, the probability of the occurrence of car accidents Pac is determined not only by the maximum speed v'max, but also the length Lv. The probability Pac increases accordingly with the increase of the maximum speed of the speed limit zone, but decreases with the increase of the length of the speed limit zone, in the low-density region. However in the case of v'max = 1, the probability Pac increases with the increase of the length in the low-density region, but decreases in the interval between the low-density and high-density regions. The speed limit zone also causes an inhomogeneous distribution of car accidents over the whole road. Theoretical analyses give an agreement with numerical results in the nondeterministic NS model with v'max = 1 and vmax = 5.

  9. Long-Term Effects of Repealing the National Maximum Speed Limit in the United States

    PubMed Central

    Hedeker, Donald; Richter, Elihu D.

    2009-01-01

    Objectives. We examined the long-term effects of the 1995 repeal of federal speed limit controls on road fatalities and injuries in fatal crashes. Methods. We used a Poisson mixed-regression model to assess changes in the number of fatalities and injuries in fatal crashes between 1995 and 2005 on rural interstates, where all US states have raised speed limits since the repeal, as well as on urban interstates and noninterstate roads, where many states have raised speed limits. Results. We found a 3.2% increase in road fatalities attributable to the raised speed limits on all road types in the United States. The highest increases were on rural interstates (9.1%) and urban interstates (4.0%). We estimated that 12 545 deaths (95% confidence interval [CI] = 8739, 16 352) and 36 583 injuries in fatal crashes (95% CI = 29 322, 43 844) were attributable to increases in speed limits across the United States. Conclusions. Reduced speed limits and improved enforcement with speed camera networks could immediately reduce speeds and save lives, in addition to reducing gas consumption, cutting emissions of air pollutants, saving valuable years of productivity, and reducing the cost of motor vehicle crashes. PMID:19608943

  10. SPEED LIMIT ON NEPTUNE MIGRATION IMPOSED BY SATURN TILTING

    SciTech Connect

    Boue, Gwenael; Laskar, Jacques; Kuchynka, Petr

    2009-09-01

    In this Letter, we give new constraints on planet migration. They were obtained under the assumption that Saturn's current obliquity is due to a capture in resonance with Neptune's ascending node. If planet migration is too fast, then Saturn crosses the resonance without being captured and it keeps a small obliquity. This scenario thus gives a lower limit on the migration timescale {tau}. We found that this boundary depends strongly on Neptune's initial inclination. For two different migration types, we found that {tau} should be at least greater than 7 Myr. This limit increases rapidly as Neptune's initial inclination decreases from 10 deg. to 1 deg. We also give an algorithm to know if Saturn can be tilted for any migration law.

  11. Examination of the wind speed limit function in the Rothermel surface fire spread model

    Treesearch

    Patricia L. Andrews; Miguel G. Cruz; Richard C. Rothermel

    2013-01-01

    The Rothermel surface fire spread model includes a wind speed limit, above which predicted rate of spread is constant. Complete derivation of the wind limit as a function of reaction intensity is given, along with an alternate result based on a changed assumption. Evidence indicates that both the original and the revised wind limits are too restrictive. Wind limit is...

  12. Materials at 200 mph: Making NASCAR Faster and Safer

    NASA Astrophysics Data System (ADS)

    Leslie-Pelecky, Diandra

    2008-03-01

    You cannot win a NASCAR race without understanding science.ootnotetextDiandra Leslie-Pelecky, The Physics of NASCAR (Dutton, New York City, 2008). Materials play important roles in improving performance, as well as ensuring safety. On the performance side, NASCAR limits the materials race car scientists and engineers can use to limit ownership costs. `Exotic metals' are not allowed, so controlling microstructure and nanostructure are important tools. Compacted Graphite Iron, a cast iron in which magnesium additions produce interlocking microscale graphite reinforcements, makes engine blocks stronger and lighter. NASCAR's new car design employs a composite called Tegris^TM that has 70 percent of the strength of carbon fiber composites at about 10 percent of the cost. The most important role of materials in racing is safety. Drivers wear firesuits made of polymers that carbonize (providing thermal protection) and expand (reducing oxygen access) when heated. Catalytic materials originally developed for space-based CO2 lasers filter air for drivers during races. Although materials help cars go fast, they also help cars slow down safely---important because the kinetic energy of a race car going 180 mph is nine times greater than that of a passenger car going 60 mph. Energy-absorbing foams in the cars and on the tracks control energy dissipation during accidents. To say that most NASCAR fans (and there are estimated to be 75 million of them) are passionate about their sport is an understatement. NASCAR fans understand that science and engineering are integral to keeping their drivers safe and helping their teams win. Their passion for racing gives us a great opportunity to share our passion for science with them. NASCAR^ is a registered trademark of the National Association for Stock Car Auto Racing, Inc. Tegris^TM is a trademark of Milliken & Company.

  13. The effect on highway NO{sub x} emissions of abolishing national speed limits

    SciTech Connect

    Mullen, M.A.; Wilson, J.H. Jr.; Gottsman, L.

    1996-12-31

    The National Highway System bill passed by Congress in 1995 abolished the national maximum speed limit. An analysis performed for EPA during the bill debate provides a comprehensive look at the implications of raising speed limits on highway vehicle NO{sub x} emissions. With the passage of the National Highway System Bill, states have the authority to determine the maximum allowable speed limits for all vehicles within their boundaries. The likely effect of the change in the law was-and has turned out to be-raised speed limits on rural freeways. This analysis projects NO{sub x} emissions rising by 5 percent nationally with expected higher speed limits. States such as Montana, North Dakota, and South Dakota that have high rural Interstate VMT relative to urban VMT show the highest NO{sub x} increases. By contrast, states like New Jersey, California, and Illinois with a preponderance of urban travel show relatively small projected emission increases from the speed change. This paper also reviews current speed limit status in the fifty states. However, because states may change their limits at any time, it does not analyze an end result of the change in the law.

  14. Raised Speed Limits, Speed Spillover, Case-Fatality Rates, and Road Deaths in Israel: A 5-Year Follow-Up

    PubMed Central

    Richter, Elihu D.; Barach, Paul; Friedman, Lee; Krikler, Samuel; Israeli, Abraham

    2004-01-01

    Objectives. We assessed the 5-year, nationwide impact on road deaths of the raise in the speed limit (November 1, 1993) on 3 major interurban highways in Israel from 90 to 100 kph. Methods. We compared before–after trends in deaths as well as case fatality—an outcome independent of exposure (defined as vehicle-kilometers traveled). Results. After the raise, speeds rose by 4.5%–9.1%. Over 5 years, there was a sustained increase in deaths (15%) and case fatality rates (38%) on all interurban roads. Corresponding increases in deaths (13%) and case fatality (24%) on urban roads indicated “speed spillover.” Conclusions. Immediate increases in case fatality predicted and tracked the sustained increase in deaths from increased speeds of impact. Newtonian fourth power models predicted the effects of “small” increases in speed on large rises in case fatality rates. Countermeasures and congestion reduced the impact on deaths and case-fatality rates by more than half. PMID:15054007

  15. 14 CFR 65.107 - Repairman certificate (light-sport aircraft): Eligibility, privileges, and limits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Repairman certificate (light-sport aircraft... CREWMEMBERS Repairmen § 65.107 Repairman certificate (light-sport aircraft): Eligibility, privileges, and...-sport aircraft) and appropriate rating: To be eligible for You must (1) A repairman certificate (light...

  16. 14 CFR 65.107 - Repairman certificate (light-sport aircraft): Eligibility, privileges, and limits.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Repairman certificate (light-sport aircraft... CREWMEMBERS Repairmen § 65.107 Repairman certificate (light-sport aircraft): Eligibility, privileges, and...-sport aircraft) and appropriate rating: To be eligible for You must (1) A repairman certificate...

  17. 14 CFR 65.107 - Repairman certificate (light-sport aircraft): Eligibility, privileges, and limits.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Repairman certificate (light-sport aircraft... CREWMEMBERS Repairmen § 65.107 Repairman certificate (light-sport aircraft): Eligibility, privileges, and...-sport aircraft) and appropriate rating: To be eligible for You must (1) A repairman certificate...

  18. 14 CFR 65.107 - Repairman certificate (light-sport aircraft): Eligibility, privileges, and limits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Repairman certificate (light-sport aircraft... CREWMEMBERS Repairmen § 65.107 Repairman certificate (light-sport aircraft): Eligibility, privileges, and...-sport aircraft) and appropriate rating: To be eligible for You must (1) A repairman certificate...

  19. 40 CFR 65.118 - Alternative means of emission limitation: Enclosed-vented process units.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Equipment Leaks § 65.118... control device. Process units that are enclosed in such a manner that all emissions from equipment leaks... following records: (1) Identification of the process unit(s) and the regulated materials they handle. (2)...

  20. 40 CFR 65.118 - Alternative means of emission limitation: Enclosed-vented process units.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Equipment Leaks § 65.118... control device. Process units that are enclosed in such a manner that all emissions from equipment leaks... following records: (1) Identification of the process unit(s) and the regulated materials they handle. (2)...

  1. 40 CFR 65.118 - Alternative means of emission limitation: Enclosed-vented process units.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Equipment Leaks § 65.118... control device. Process units that are enclosed in such a manner that all emissions from equipment leaks... following records: (1) Identification of the process unit(s) and the regulated materials they handle. (2)...

  2. The Speed Limit for Graphene Interstellar Photon Sails

    NASA Astrophysics Data System (ADS)

    Matloff, G. L.

    Graphene, a two-dimensional carbon molecular monolayer, has properties that may render it very useful for application to interstellar solar photon sailing. These include very low areal mass thickness, high melting point, high impermeability to fill gas in a hollow-body sail configuration, and high tensile strength. With appropriate "additives," graphene has a finite reflectance to sunlight and sunlight absorption of 40% or higher. Here, we evaluate the probably unobtainable ultimate performance of this material. It is assumed that absorption can be raised to 95% and reflectance to 5% without increasing areal mass thickness over the graphene value of 7.4 * 10-7 kg/m2. It is also assumed that the only limitations on perihelion distance are thermal; spaceenvironment effects and possible variation of optical properties with temperature are ignored. To evaluate ultimate performance, an initially parabolic solar orbit with a ~0.01 AU perihelion is assumed. A thin-film probe with the payload integrated with the sail can achieve an interstellar cruise velocity of ~0.046c in the highly unlikely event that accelerations of ~6,000g can be tolerated. Regardless of the final velocity, graphene "Starwisps" might see application in interstellar particle-beam propulsion.

  3. Conduit speed limit promotes formation of explosive `super slugs'

    NASA Astrophysics Data System (ADS)

    Llewellin, E. W.; Burton, M. R.; Mader, H. M.; Polacci, M.

    2014-12-01

    Strombolian activity - characterized by discrete, impulsive explosions - is common at basaltic volcanoes. The explosions are caused by the arrival, at the volcanic vent, of over-pressured `slugs' of magmatic gas, which have ascended the volcanic conduit. We present data from large-scale analogue experiments which reveal a previously-undescribed process which promotes the formation of large, highly over-pressured `super slugs'. We propose that these large slugs may drive the most violent Strombolian eruptions. Experiments were performed at the Large Analogue Volcano Apparatus at Durham University, UK, which comprises a 13m tall, 24cm diameter transparent conduit, surmounting a reservoir of analogue magma held at constant pressure. We simulate a vesiculation event deep in the sub-volcanic plumbing system by fluxing gas into the reservoir. Magma analogues with a range of viscosities are used, giving slug Reynolds numbers in the range 16 to 140,000. At moderate-to-high Reynolds number, we find that the gas rapidly self-organizes to form a conduit-filling lead slug; this slug ascends the column slowly, at a velocity limited by the flux of the falling film of liquid around it. Trailing bubbles, which ascend through the wake of the lead slug, rise much more rapidly. As they catch and coalesce with the lead slug, it grows and becomes increasingly over-pressured. This mechanism causes large slugs to form rapidly and we propose that it underpins the formation of the very large slugs that are responsible for the most explosive strombolian eruptions.

  4. The Research Forum for MPH students.

    PubMed

    Gofin, Rosa

    2002-01-01

    Over the years, the experience with the Research Forum has shown that the framework is effective in providing the time frame and the academic support for the preparation of the proposals. It provides the students with an additional opportunity for the integration of knowledge gained during the MPH core and elective courses and for developing skills in writing and appraising a proposal or an essay on a public health issue. For the faculty it is another instance in which methodological issues are stressed, public health themes are discussed, and a systematic approach is emphasized. This process helps the students to achieve high academic levels for their proposals, and the final theses or papers are enhanced. This is evidenced by the fact that many of these works are also published in peer-reviewed journals, a sample of which is shown in the references. Students from Countries of Eastern Europe and the Commonwealth of Independent States have the opportunity to apply to the Soros Foundation Open Society Institute (OSI) for projects on their return to their home institution, which may include a continuation of their research project or master's paper topic. This project is to be carried out during the first year of their return home with financial support up to $5,000. These projects have been presented to Braun SPH faculty at summer seminars held in Russia in 2001 and 2002.

  5. Performance of low-pressure-ratio low-tip-speed fan stage with blade tip solidity of 0.65

    NASA Technical Reports Server (NTRS)

    Kovich, G.; Steinke, R. J.

    1976-01-01

    The overall and blade-element performance of a low pressure ratio, low tip speed fan stage is presented over the stable operating range at rotative speeds from 90 to 120 percent of design speed. Stage peak efficiency of 0.927 was obtained at a weight flow of 32.4 kg/sec (190.31 kg/sec/sq m of annulus area) and a pressure ratio of 1.134. The stall margin at design speed and peak efficiency was 15.3 percent.

  6. Consideration of tip speed limitations in preliminary analysis of minimum COE wind turbines

    NASA Astrophysics Data System (ADS)

    Cuerva-Tejero, A.; Yeow, T. S.; Lopez-Garcia, O.; Gallego-Castillo, C.

    2014-12-01

    A relation between Cost Of Energy, COE, maximum allowed tip speed, and rated wind speed, is obtained for wind turbines with a given goal rated power. The wind regime is characterised by the corresponding parameters of the probability density function of wind speed. The non-dimensional characteristics of the rotor: number of blades, the blade radial distributions of local solidity, twist, angle, and airfoil type, play the role of parameters in the mentioned relation. The COE is estimated using a cost model commonly used by the designers. This cost model requires basic design data such as the rotor radius and the ratio between the hub height and the rotor radius. Certain design options, DO, related to the technology of the power plant, tower and blades are also required as inputs. The function obtained for the COE can be explored to find those values of rotor radius that give rise to minimum cost of energy for a given wind regime as the tip speed limitation changes. The analysis reveals that iso-COE lines evolve parallel to iso-radius lines for large values of limit tip speed but that this is not the case for small values of the tip speed limits. It is concluded that., as the tip speed limit decreases, the optimum decision for keeping minimum COE values can be: a) reducing the rotor radius for places with high weibull scale parameter or b) increasing the rotor radius for places with low weibull scale parameter.

  7. Towards setting credible speed limits: Identifying factors that affect driver compliance on urban roads.

    PubMed

    Gargoum, Suliman A; El-Basyouny, Karim; Kim, Amy

    2016-10-01

    Road geometry, vehicle characteristics, and weather conditions are all factors that impact a driver's perception of a safe or credible speed and, consequently, the driver's decision on whether or not to comply with the posted speed limit. In fact, the role a road's environment plays in a driver's perception of a credible speed limit is a topic that has attracted the interest of many researchers in recent years. Despite that, not many studies have considered using empirical data to investigate what features of the road environment influence a driver's compliance choice. This paper aims to address this matter by exploring the relationships between features of the road surroundings (geometric, temporal factors, and weather conditions) and driver compliance with speed limits. The paper uses data from almost 600 different urban roads in the city of Edmonton, at which over 35 million vehicle spot speeds were collected. Compliance was represented using a categorical ordered response variable, and mixed-effects-logistic-regression models were fitted. Two different models were built, one for arterials and another for collector roads. In general, the findings show that the more restricted drivers become, particularly on arterials, the more likely drivers are to comply with speed limits; potential restrictions include on-street parking and the absence of lateral shoulders. Furthermore, higher traffic activity during peak hours, and presumably on shoulder weekdays, both increase the likelihood of compliance on arterials. Similarly, posted speed limits and traffic volume are both positively correlated with compliance on both arterial and collector roads. The findings of this research provide evidence of the existence of an empirical relationship between road features and compliance, highlighting the importance of setting credible speed limits on roads and the possibility of achieving higher compliance rates through modifications to the road environment. Copyright © 2016

  8. Modeling Individual Differences in Numerical Reasoning Speed as a Random Effect of Response Time Limits

    ERIC Educational Resources Information Center

    Semmes, Robert; Davison, Mark L.; Close, Catherine

    2011-01-01

    If numerical reasoning items are administered under time limits, will two dimensions be required to account for the responses, a numerical ability dimension and a speed dimension? A total of 182 college students answered 74 numerical reasoning items. Every item was taken with and without time limits by half the students. Three psychometric models…

  9. Modeling Individual Differences in Numerical Reasoning Speed as a Random Effect of Response Time Limits

    ERIC Educational Resources Information Center

    Semmes, Robert; Davison, Mark L.; Close, Catherine

    2011-01-01

    If numerical reasoning items are administered under time limits, will two dimensions be required to account for the responses, a numerical ability dimension and a speed dimension? A total of 182 college students answered 74 numerical reasoning items. Every item was taken with and without time limits by half the students. Three psychometric models…

  10. Ashley Felix, Ph.D., M.P.H.

    Cancer.gov

    NCI Cancer Prevention Fellowship Program (CPFP) alumna, Ashley Felix, Ph.D., M.P.H., details her transition from pre-med student to an epidemiologist who focuses on studying the causes and prevention of disease.

  11. 40 CFR 65.118 - Alternative means of emission limitation: Enclosed-vented process units.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... create a negative pressure in the enclosure to ensure that all emissions are routed to the control device. ... Alternative means of emission limitation: Enclosed-vented process units. (a) Use of closed vent system and control device. Process units that are enclosed in such a manner that all emissions from equipment leaks...

  12. 40 CFR 65.118 - Alternative means of emission limitation: Enclosed-vented process units.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... create a negative pressure in the enclosure to ensure that all emissions are routed to the control device. ... Alternative means of emission limitation: Enclosed-vented process units. (a) Use of closed vent system and control device. Process units that are enclosed in such a manner that all emissions from equipment leaks...

  13. Variable speed limit strategies’ analysis with cell transmission model on freeway

    NASA Astrophysics Data System (ADS)

    Li, Shubin; Cao, Danni

    2017-08-01

    Mainline freeway traffic flow control is one of the primary methods of traffic management, which can present the best network situation. In this paper, we integrate variable speed limit (VSL) strategy into the cell transmission model (CTM). Then the implementation of the integrated model on freeway traffic network is discussed. A novel optimal model of controlling freeway traffic flow is proposed for minimizing the total travelling time in the network. A solution algorithm is designed by using a simulation method. Considering the main purpose of the speed limit strategy is to control the mainstream flow, we compare the case where the VSL is used with the one without VSL. A simulation is implemented to show that the control strategy is efficient in describing system’s dynamic performance and the dynamic speed limit strategy significantly alleviates congestion.

  14. KENNEDY SPACE CENTER, FLA. - Like candles embedded in a sculptured “cake,” the Mobile Launcher Platform (MLP) number 3 with twin solid rocket boosters bolted to it inches along the crawlerway at various speeds up to 1 mph in an effort to achieve vibration data gathering goals. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Like candles embedded in a sculptured “cake,” the Mobile Launcher Platform (MLP) number 3 with twin solid rocket boosters bolted to it inches along the crawlerway at various speeds up to 1 mph in an effort to achieve vibration data gathering goals. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  15. Using business plan development as a capstone project for MPH programs in Canada: validation through the student perspective.

    PubMed

    Papadopoulos, Andrew; Britten, Nicole; Hatcher, Meghan; Rainville, Keira

    2013-10-01

    Master of Public Health (MPH) programs have been developed across Canada as a response to the need for adequately trained individuals to work in the public health sector. Educational institutions that deliver MPH programs have a responsibility to ensure that graduates of their program have the essential knowledge, skills and attitudes to begin a successful career in public health. The Public Health Agency of Canada has created the core competencies for public health to guide the development, delivery and evaluation of MPH programs. In Canada, a capstone project is the recommended method of evaluating the MPH graduate's ability to demonstrate proficiency in the public health core competencies. A business plan that develops the framework for a public health program is an ideal capstone project currently used in practice within the University of Guelph MPH program. This group assignment incorporates all 36 of the public health core competencies while providing students with a real-world public health experience, and should be considered for inclusion within MPH programs across Canada. Business planning provides students the opportunity to engage in practice-based learning, applying theoretical knowledge to practice. Further, the ability to develop realistic but financially feasible public health problems is an invaluable skill for MPH graduates. As the development of programs becomes more restricted and the continuation of other programs are under constant threat, the ability to develop a sound business plan is a required skill for individuals entering the public health sector, and will ensure students are able to maximize outcomes given tight fiscal budgets and limited resources.

  16. A new regularization technique for limited-view sound-speed imaging.

    PubMed

    Huthwaite, Peter; Zwiebel, Alicia A; Simonetti, Francesco

    2013-03-01

    Reconstructing sound-speed maps from the limited view offered by a linear array of ultrasonic sensors has been a long-standing challenge in medical diagnostics and nondestructive evaluation. Because of the limited range of angles that can be used to interrogate the volume beneath the array, the inverse problem of retrieving sound-speed maps from scattering measurements is highly ill-posed. The missing angles cause significant artifacts that degrade the image by altering the values of sound speed and producing ghost features. This paper introduces the virtual image space component iterative technique (VISCIT), which addresses the limited-view problem by introducing a new regularization technique which iteratively compensates for the missing components by applying an adaptive threshold to the reconstruction. The effectiveness of the method in yielding high-accuracy sound-speed maps is demonstrated using a complex numerical phantom and validated experimentally with an agar phantom. It is shown that sound-speed contrast as low as 1.3% is readily detectable, thus paving the way for more sensitive and selective detection of damage precursors and early stage diseases.

  17. Operating limitations of high-speed jet-lubricated ball bearings

    NASA Technical Reports Server (NTRS)

    Zaretsky, E. V.; Signer, H.; Bamberger, E. N.

    1975-01-01

    A parametric study was performed with 120-mm bore angular-contact ball bearings having a nominal contact angle of 20 deg. The bearings either had an inner- or an outer-race land riding cage. Lubrication was by recirculating oil jets. The oil jets either had a single or dual orifice. Thrust load, speed, and lubricant flow rate were varied. Test results were compared with those previously reported and obtained from bearings of the same design which were under-race lubricated but run under the same conditions. Jet lubricated ball bearings were limited to speeds less than 2,500,000 DN. Bearings having inner-race land riding cages produced lower temperatures than bearings with outer-race land riding cages. For a given lubricant flow rate dual orifice jets produced lower bearing temperatures than single orifice jets. However, under-race lubrication produced under all conditions of operation lower bearing temperatures with no apparent bearing speed limitation.

  18. Experimental low-speed and calculated high-speed aerodynamic characteristics of a hypersonic research airplane concept having a 65 deg swept delta wing

    NASA Technical Reports Server (NTRS)

    Penland, J. A.; Creel, T. R., Jr.; Howard, F. G.

    1974-01-01

    An experimental wind-tunnel investigation has been carried out to determine the static longitudinal, lateral, and directional stability and control characteristics of a model of a large-body, delta-wing hypersonic research airplane concept at low speed. This investigation was conducted at a dynamic pressure of 239.4 Pa (5 psf) and a Reynolds number, based on fuselage length, of 2 million. The configuration variables included vertical fins, engine modules, canards, and a canopy. The aerodynamic results of a computer study at Mach numbers of 3 to 12 are presented.

  19. The cooperative University of Iowa / Iowa State University MPH program.

    PubMed

    Bickett-Weddle, Danelle A; Aquilino, Mary L; Roth, James A

    2008-01-01

    Public health is an important component of veterinary medicine. In the last 10 years, there has been growing recognition of the need to increase the number of veterinarians trained in public health. The Center for Food Security and Public Health (CFSPH) at Iowa State University (ISU), College of Veterinary Medicine, received a grant from the Centers for Disease Control and Prevention (CDC) to support veterinarians working at CFSPH while pursuing the Master of Public Health degree. CFSPH and ISU administrators worked with the University of Iowa (UI) College of Public Health to establish three cooperative programs for veterinarians to earn the MPH degree. This article describes how these programs were developed and how they operate. (1) Between 2002 and 2005, CFSPH used funds provided by the CDC to support 15 veterinarians as they worked for CFSPH and toward the MPH degree. As the program grew, distance-education methods such as the Internet, Polycom videoconferencing, and the Iowa Communications Network (ICN) were incorporated. (2) A concurrent DVM/MPH degree is now offered; students can complete both degrees in four years. As of January 2008, three students have received their DVM and MPH degrees and 16 students are enrolled in the program. (3) In June 2007, the UI and ISU launched a distance MPH program for veterinarians working in private practice, industry, and government. Eight veterinarians are participating in the program, which includes two two-week, in-person summer sessions, with the remainder of the coursework taken at a distance via the Internet.

  20. Educational differences in functional limitations: comparisons of 55-65-year-olds in the Netherlands in 1992 and 2002.

    PubMed

    Hoogendijk, Emiel; van Groenou, Marjolein Broese; van Tilburg, Theo; Deeg, Dorly

    2008-01-01

    This study compares educational differences in the functional limitations of 55-65-year-olds in the Netherlands in 1992 and 2002 and examines whether changes are explained by cohort lifestyle and psychosocial changes. Data from two cohorts of 55-65-year-olds (n = 948 in 1992 and n = 980 in 2002) in the Longitudinal Aging Study Amsterdam are analysed. Men's disability ratios are similar in both cohorts. The women's disability ratio is higher in 2002 than in 1992. In 2002 the male and female cohorts both report unhealthier behavior than in 1992. Multivariate logistic regression analyses show that adjusted for age, cohort, lifestyle and psychosocial resources, poorly educated men have higher odds of functional limitations than well-educated men (OR = 2.62, 95% CI = 1.57-4.37). Analyses among women show a significant interaction effect between education and cohort. Poorly educated women have higher odds of functional limitations in 2002 than in 1992 (OR = 3.33, 95% CI = 1.02-10.87). The results underscore the need for policies focused on improving the health and lifestyle of the poorly educated.

  1. Comparative Drag Measurements at Transonic Speeds of Rectangular Sweptback NACA 65-009 Airfoils Mounted on a Freely Falling Body

    NASA Technical Reports Server (NTRS)

    Mathews, Charles W; Thompson, Jim Rogers

    1950-01-01

    Directly comparable drag measurements have been made of an airfoil with a conventional rectangular plan form and an airfoil with a sweptback plan form mounted on freely falling bodies. Both airfoils had NACA 65-009 sections and were identical in span, frontal area, and chord perpendicular to the leading edge. The sweptback plan form incorporated a sweepback angle of 45 degrees. The data obtained have been used to establish the relation between the airfoil drag coefficients and the free-stream Mach number over a range of Mach numbers from 0.90 to 1.27. The results of the measurements indicate that the drag of the sweptback plan form is less than 0.3 that of the rectangular plan form at a Mach number of 1.00 and is less than 0.4 that at a Mach number of 1.20.

  2. Turbulent Vortex-Flow Simulation Over a 65 deg Sharp and Blunt Leading-Edge Delta Wing at Subsonic Speeds

    NASA Technical Reports Server (NTRS)

    Ghaffari, Farhad

    2005-01-01

    Turbulent thin-layer, Reynolds-Averaged Navier-Stokes solutions, based on a multi-block structured grid, are presented for a 65 deg delta wing having either a sharp leading edge (SLE) or blunt leading edge (BLE) geometry. The primary objective of the study is to assess the prediction capability of the method for simulating the leading-edge flow separation and the ensuing vortex flow characteristics. Computational results are obtained for two angles of attack of approximately 13 and 20 deg, at free-stream Mach number of 0.40 and Reynolds number of 6 million based on the wing mean aerodynamic chord. The effects of two turbulence models of Baldwin-Lomax with Degani-Schiff (BL/DS) and the Spalart-Allmaras (SA) on the numerical results are also discussed. The computations also explore the effects of two numerical flux-splitting schemes, i.e., flux difference splitting (fds) and flux vector splitting (fvs), on the solution development and convergence characteristics. The resulting trends in solution sensitivity to grid resolution for the selected leading-edge geometries, angles of attack, turbulence models and flux splitting schemes are also presented. The validity of the numerical results is evaluated against a unique set of experimental wind-tunnel data that was obtained in the National Transonic Facility at the NASA Langley Research Center.

  3. Limits on Light-Speed Anisotropies from Compton Scattering of High-Energy Electrons

    NASA Astrophysics Data System (ADS)

    Bocquet, J.-P.; Moricciani, D.; Bellini, V.; Beretta, M.; Casano, L.; D'Angelo, A.; di Salvo, R.; Fantini, A.; Franco, D.; Gervino, G.; Ghio, F.; Giardina, G.; Girolami, B.; Giusa, A.; Gurzadyan, V. G.; Kashin, A.; Knyazyan, S.; Lapik, A.; Lehnert, R.; Levi Sandri, P.; Lleres, A.; Mammoliti, F.; Mandaglio, G.; Manganaro, M.; Margarian, A.; Mehrabyan, S.; Messi, R.; Nedorezov, V.; Perrin, C.; Randieri, C.; Rebreyend, D.; Rudnev, N.; Russo, G.; Schaerf, C.; Sperduto, M. L.; Sutera, M. C.; Turinge, A.; Vegna, V.

    2010-06-01

    The possibility of anisotropies in the speed of light relative to the limiting speed of electrons is considered. The absence of sidereal variations in the energy of Compton-edge photons at the European Synchrotron Radiation Facility’s GRAAL facility constrains such anisotropies representing the first nonthreshold collision-kinematics study of Lorentz violation. When interpreted within the minimal standard-model extension, this result yields the two-sided limit of 1.6×10-14 at 95% confidence level on a combination of the parity-violating photon and electron coefficients (κ˜o+)YZ, (κ˜o+)ZX, cTX, and cTY. This new constraint provides an improvement over previous bounds by 1 order of magnitude.

  4. Limits on light-speed anisotropies from Compton scattering of high-energy electrons.

    PubMed

    Bocquet, J-P; Moricciani, D; Bellini, V; Beretta, M; Casano, L; D'Angelo, A; Di Salvo, R; Fantini, A; Franco, D; Gervino, G; Ghio, F; Giardina, G; Girolami, B; Giusa, A; Gurzadyan, V G; Kashin, A; Knyazyan, S; Lapik, A; Lehnert, R; Levi Sandri, P; Lleres, A; Mammoliti, F; Mandaglio, G; Manganaro, M; Margarian, A; Mehrabyan, S; Messi, R; Nedorezov, V; Perrin, C; Randieri, C; Rebreyend, D; Rudnev, N; Russo, G; Schaerf, C; Sperduto, M L; Sutera, M C; Turinge, A; Vegna, V

    2010-06-18

    The possibility of anisotropies in the speed of light relative to the limiting speed of electrons is considered. The absence of sidereal variations in the energy of Compton-edge photons at the European Synchrotron Radiation Facility's GRAAL facility constrains such anisotropies representing the first nonthreshold collision-kinematics study of Lorentz violation. When interpreted within the minimal standard-model extension, this result yields the two-sided limit of 1.6×10(-14) at 95% confidence level on a combination of the parity-violating photon and electron coefficients (κ(o+))(YZ), (κ(o+))(ZX), c(TX), and c(TY). This new constraint provides an improvement over previous bounds by 1 order of magnitude.

  5. Dystonia with MPH/Risperidone Combined Therapy for ADHD.

    PubMed

    Millichap, J Gordon; Yee, Michelle M

    2016-01-01

    Investigators from Child Neurology and Pediatrics, University of Texas Health Science Center, Houston, report extrapyramidal symptoms in a 13-year-old boy with a psychiatric history of schizophrenia, bipolar disorder, ADHD, and autism, responsive to combination risperidone, oxcarbazepine, and MPH.

  6. Development of a variable speed limit strategy to reduce secondary collision risks during inclement weathers.

    PubMed

    Li, Zhibin; Li, Ye; Liu, Pan; Wang, Wei; Xu, Chengcheng

    2014-11-01

    Inclement weather reduces traveler's sight distance and increases vehicle's stopping distance. Once a collision occurred during inclement weather and resulted in a slow traffic, approaching vehicles may not have adequate time to make emergency responses to the hazardous traffic, resulting in increased potentials of secondary collisions. The primary objective of this study is to develop a control strategy of variable speed limits (VSL) to reduce the risks of secondary collisions during inclement weathers. By analyzing the occurrence condition of secondary collision, the VSL strategy is proposed to dynamically adjust the speed limits according to the current traffic and weather conditions. A car-following model is modified to simulate the vehicle maneuvers with the VSL control. Two surrogate safety measures, based on the time-to-collision notion, are used to evaluate the control effects of VSL. Five weather scenarios are evaluated in simulation. The results show that the VSL strategy effectively reduces the risks of secondary collisions in various weather types. The time exposed time-to-collision (TET) is reduced by 41.45%-50.74%, and the time integrated time-to-collision (TIT) is reduced by 38.19%-41.19%. The safety effects are compared to those with a previous VSL strategy. The results show that in most cases our strategy outperforms the previous one. We also evaluate how driver's compliance to speed limit affects the effectiveness of VSL control. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. High-speed holographic metrology: principle, limitations, and application to vibroacoustics of structures

    NASA Astrophysics Data System (ADS)

    Poittevin, Julien; Gautier, François; Pézerat, Charles; Picart, Pascal

    2016-12-01

    This paper describes the basics of high-speed holographic metrology, its limitations, and its application to the investigation of traveling acoustic waves propagating in mechanical structures. Limits are related to a few parameters that must be carefully adjusted for the recording. A full numerical simulation of the recording-reconstruction holographic process is presented and used to investigate the decorrelation phase noise induced by spatial resolution, active surface of pixels, and short exposure time. Applications to vibroacoustics of structures consider the case of waves propagating after a shock by impact hammer and wave interaction in one-dimensional and two-dimensional acoustic black hole extremities.

  8. The role of gender in MPH graduates' salaries.

    PubMed

    Bradley, E H; White, W; Anderson, E; Mattocks, K; Pistell, A

    2000-01-01

    Several studies have demonstrated that workforce roles and salaries differ substantially between men and women in administrative positions within the health care industry. Recent studies of graduates with masters of business administration (MBA) and masters of health administration (MHA) degrees have indicated that women tend to experience lower salaries, given like responsibilities. However, the impact of gender on salary has been less studied among masters of public health (MPH) graduates in the health care field. Our objective was to assess the impact of gender on salary among MPH degree graduates. Using a cross-sectional survey of all graduates from the MPH program at Yale University between 1991-1997 (n = 201, response rate = 51%), we ascertained graduates' reported salary in the first job post-graduation and reported salary in their current position. Bivariate and multivariate analyses were used to assess the unadjusted and adjusted associations between gender and salary. Salaries in both the first job post-graduation and in the current job differed significantly by gender, with women earning less than men (p-values < .05). Moreover, these differences persisted after controlling for a set of human capital measures including pre-MPH work experience, age at graduation, years since graduation, area of specialization within the MPH degree, and type of work site (governmental or nonprofit versus for-profit). Unlike studies of MBA and MHA graduates, however, this study did not find evidence that the gender-related salary gap widened as the years since graduation increased, although the sample size did not allow comprehensive testing of this trend.

  9. Optimal Speed Limits for School Buses on Virginia Highways: A Report to Virginia's Superintendent of Public Instruction.

    ERIC Educational Resources Information Center

    Jernigan, Jack D.; Lynn, Cheryl W.

    A study to assess whether the school bus speed limit should be changed in Virginia is described in this report. The relationship between the safety characteristics of Virginia's three-tiered speed limit system and school bus operation is examined to determine the optimal level of safety for school bus travel. Virginia allows the following three…

  10. Limits to high-speed simulations of spiking neural networks using general-purpose computers.

    PubMed

    Zenke, Friedemann; Gerstner, Wulfram

    2014-01-01

    To understand how the central nervous system performs computations using recurrent neuronal circuitry, simulations have become an indispensable tool for theoretical neuroscience. To study neuronal circuits and their ability to self-organize, increasing attention has been directed toward synaptic plasticity. In particular spike-timing-dependent plasticity (STDP) creates specific demands for simulations of spiking neural networks. On the one hand a high temporal resolution is required to capture the millisecond timescale of typical STDP windows. On the other hand network simulations have to evolve over hours up to days, to capture the timescale of long-term plasticity. To do this efficiently, fast simulation speed is the crucial ingredient rather than large neuron numbers. Using different medium-sized network models consisting of several thousands of neurons and off-the-shelf hardware, we compare the simulation speed of the simulators: Brian, NEST and Neuron as well as our own simulator Auryn. Our results show that real-time simulations of different plastic network models are possible in parallel simulations in which numerical precision is not a primary concern. Even so, the speed-up margin of parallelism is limited and boosting simulation speeds beyond one tenth of real-time is difficult. By profiling simulation code we show that the run times of typical plastic network simulations encounter a hard boundary. This limit is partly due to latencies in the inter-process communications and thus cannot be overcome by increased parallelism. Overall, these results show that to study plasticity in medium-sized spiking neural networks, adequate simulation tools are readily available which run efficiently on small clusters. However, to run simulations substantially faster than real-time, special hardware is a prerequisite.

  11. A limit on the variation of the speed of light arising from quantum gravity effects

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Asano, K.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bhat, P. N.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bonnell, J.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Briggs, M. S.; Brigida, M.; Bruel, P.; Burgess, J. M.; Burnett, T. H.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Chaplin, V.; Charles, E.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Connaughton, V.; Conrad, J.; Cutini, S.; Dermer, C. D.; de Angelis, A.; de Palma, F.; Digel, S. W.; Dingus, B. L.; do Couto e Silva, E.; Drell, P. S.; Dubois, R.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Finke, J.; Fishman, G.; Focke, W. B.; Foschini, L.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Gibby, L.; Giebels, B.; Giglietto, N.; Giordano, F.; Glanzman, T.; Godfrey, G.; Granot, J.; Greiner, J.; Grenier, I. A.; Grondin, M. -H.; Grove, J. E.; Grupe, D.; Guillemot, L.; Guiriec, S.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hoversten, E. A.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Johnson, R. P.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Kerr, M.; Kippen, R. M.; Knödlseder, J.; Kocevski, D.; Kouveliotou, C.; Kuehn, F.; Kuss, M.; Lande, J.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Mazziotta, M. N.; McBreen, S.; McEnery, J. E.; McGlynn, S.; Mészáros, P.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paciesas, W. S.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Porter, T. A.; Preece, R.; Rainò, S.; Ramirez-Ruiz, E.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Ritz, S.; Rochester, L. S.; Rodriguez, A. Y.; Roth, M.; Ryde, F.; Sadrozinski, H. F. -W.; Sanchez, D.; Sander, A.; Saz Parkinson, P. M.; Scargle, J. D.; Schalk, T. L.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spandre, G.; Spinelli, P.; Stamatikos, M.; Stecker, F. W.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Toma, K.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Uehara, T.; Usher, T. L.; van der Horst, A. J.; Vasileiou, V.; Vilchez, N.; Vitale, V.; von Kienlin, A.; Waite, A. P.; Wang, P.; Wilson-Hodge, C.; Winer, B. L.; Wood, K. S.; Wu, X. F.; Yamazaki, R.; Ylinen, T.; Ziegler, M.

    2009-10-28

    A cornerstone of Einstein's special relativity is Lorentz invariance—the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon-energy. While special relativity assumes that there is no fundamental length-scale associated with such invariance, there is a fundamental scale (the Planck scale, lPlanck ≈ 1.62 x 10-33 cm or EPlanck = MPlanckc2 ≈ 1.22 x 1019 GeV), at which quantum effects are expected to strongly affect the nature of space–time. There is great interest in the (not yet validated) idea that Lorentz invariance might break near the Planck scale. A key test of such violation of Lorentz invariance is a possible variation of photon speed with energy. Even a tiny variation in photon speed, when accumulated over cosmological light-travel times, may be revealed by observing sharp features in γ-ray burst (GRB) light-curves. In this paper, we report the detection of emission up to ~31 GeV from the distant and short GRB 090510. We find no evidence for the violation of Lorentz invariance, and place a lower limit of 1.2EPlanck on the scale of a linear energy dependence (or an inverse wavelength dependence), subject to reasonable assumptions about the emission (equivalently we have an upper limit of lPlanck/1.2 on the length scale of the effect). Finally, our results disfavour quantum-gravity theories in which the quantum nature of space–time on a very small scale linearly alters the speed of light.

  12. A limit on the variation of the speed of light arising from quantum gravity effects.

    PubMed

    Abdo, A A; Ackermann, M; Ajello, M; Asano, K; Atwood, W B; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Baring, M G; Bastieri, D; Bechtol, K; Bellazzini, R; Berenji, B; Bhat, P N; Bissaldi, E; Bloom, E D; Bonamente, E; Bonnell, J; Borgland, A W; Bouvier, A; Bregeon, J; Brez, A; Briggs, M S; Brigida, M; Bruel, P; Burgess, J M; Burnett, T H; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Celik, O; Chaplin, V; Charles, E; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L R; Connaughton, V; Conrad, J; Cutini, S; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; Dingus, B L; do Couto E Silva, E; Drell, P S; Dubois, R; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Finke, J; Fishman, G; Focke, W B; Foschini, L; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Gibby, L; Giebels, B; Giglietto, N; Giordano, F; Glanzman, T; Godfrey, G; Granot, J; Greiner, J; Grenier, I A; Grondin, M-H; Grove, J E; Grupe, D; Guillemot, L; Guiriec, S; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hoversten, E A; Hughes, R E; Jóhannesson, G; Johnson, A S; Johnson, R P; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Kippen, R M; Knödlseder, J; Kocevski, D; Kouveliotou, C; Kuehn, F; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Mazziotta, M N; McBreen, S; McEnery, J E; McGlynn, S; Mészáros, P; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Moretti, E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Nolan, P L; Norris, J P; Nuss, E; Ohno, M; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Ozaki, M; Paciesas, W S; Paneque, D; Panetta, J H; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Petrosian, V; Piron, F; Porter, T A; Preece, R; Rainò, S; Ramirez-Ruiz, E; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, L S; Rodriguez, A Y; Roth, M; Ryde, F; Sadrozinski, H F-W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Schalk, T L; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Stamatikos, M; Stecker, F W; Strickman, M S; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J B; Thayer, J G; Thompson, D J; Tibaldo, L; Toma, K; Torres, D F; Tosti, G; Troja, E; Uchiyama, Y; Uehara, T; Usher, T L; van der Horst, A J; Vasileiou, V; Vilchez, N; Vitale, V; von Kienlin, A; Waite, A P; Wang, P; Wilson-Hodge, C; Winer, B L; Wood, K S; Wu, X F; Yamazaki, R; Ylinen, T; Ziegler, M

    2009-11-19

    A cornerstone of Einstein's special relativity is Lorentz invariance-the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon-energy. While special relativity assumes that there is no fundamental length-scale associated with such invariance, there is a fundamental scale (the Planck scale, l(Planck) approximately 1.62 x 10(-33) cm or E(Planck) = M(Planck)c(2) approximately 1.22 x 10(19) GeV), at which quantum effects are expected to strongly affect the nature of space-time. There is great interest in the (not yet validated) idea that Lorentz invariance might break near the Planck scale. A key test of such violation of Lorentz invariance is a possible variation of photon speed with energy. Even a tiny variation in photon speed, when accumulated over cosmological light-travel times, may be revealed by observing sharp features in gamma-ray burst (GRB) light-curves. Here we report the detection of emission up to approximately 31 GeV from the distant and short GRB 090510. We find no evidence for the violation of Lorentz invariance, and place a lower limit of 1.2E(Planck) on the scale of a linear energy dependence (or an inverse wavelength dependence), subject to reasonable assumptions about the emission (equivalently we have an upper limit of l(Planck)/1.2 on the length scale of the effect). Our results disfavour quantum-gravity theories in which the quantum nature of space-time on a very small scale linearly alters the speed of light.

  13. A limit on the variation of the speed of light arising from quantum gravity effects

    DOE PAGES

    Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

    2009-10-28

    A cornerstone of Einstein's special relativity is Lorentz invariance—the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon-energy. While special relativity assumes that there is no fundamental length-scale associated with such invariance, there is a fundamental scale (the Planck scale, lPlanck ≈ 1.62 x 10-33 cm or EPlanck = MPlanckc2 ≈ 1.22 x 1019 GeV), at which quantum effects are expected to strongly affect the nature of space–time. There is great interest in the (not yet validated) idea that Lorentz invariance might break near the Planck scale. A key test of such violationmore » of Lorentz invariance is a possible variation of photon speed with energy. Even a tiny variation in photon speed, when accumulated over cosmological light-travel times, may be revealed by observing sharp features in γ-ray burst (GRB) light-curves. In this paper, we report the detection of emission up to ~31 GeV from the distant and short GRB 090510. We find no evidence for the violation of Lorentz invariance, and place a lower limit of 1.2EPlanck on the scale of a linear energy dependence (or an inverse wavelength dependence), subject to reasonable assumptions about the emission (equivalently we have an upper limit of lPlanck/1.2 on the length scale of the effect). Finally, our results disfavour quantum-gravity theories in which the quantum nature of space–time on a very small scale linearly alters the speed of light.« less

  14. Limits to high-speed simulations of spiking neural networks using general-purpose computers

    PubMed Central

    Zenke, Friedemann; Gerstner, Wulfram

    2014-01-01

    To understand how the central nervous system performs computations using recurrent neuronal circuitry, simulations have become an indispensable tool for theoretical neuroscience. To study neuronal circuits and their ability to self-organize, increasing attention has been directed toward synaptic plasticity. In particular spike-timing-dependent plasticity (STDP) creates specific demands for simulations of spiking neural networks. On the one hand a high temporal resolution is required to capture the millisecond timescale of typical STDP windows. On the other hand network simulations have to evolve over hours up to days, to capture the timescale of long-term plasticity. To do this efficiently, fast simulation speed is the crucial ingredient rather than large neuron numbers. Using different medium-sized network models consisting of several thousands of neurons and off-the-shelf hardware, we compare the simulation speed of the simulators: Brian, NEST and Neuron as well as our own simulator Auryn. Our results show that real-time simulations of different plastic network models are possible in parallel simulations in which numerical precision is not a primary concern. Even so, the speed-up margin of parallelism is limited and boosting simulation speeds beyond one tenth of real-time is difficult. By profiling simulation code we show that the run times of typical plastic network simulations encounter a hard boundary. This limit is partly due to latencies in the inter-process communications and thus cannot be overcome by increased parallelism. Overall, these results show that to study plasticity in medium-sized spiking neural networks, adequate simulation tools are readily available which run efficiently on small clusters. However, to run simulations substantially faster than real-time, special hardware is a prerequisite. PMID:25309418

  15. Minimal evolution time and quantum speed limit of non-Markovian open systems

    PubMed Central

    Meng, Xiangyi; Wu, Chengjun; Guo, Hong

    2015-01-01

    We derive a sharp bound as the quantum speed limit (QSL) for the minimal evolution time of quantum open systems in the non-Markovian strong-coupling regime with initial mixed states by considering the effects of both renormalized Hamiltonian and dissipator. For a non-Markovian quantum open system, the possible evolution time between two arbitrary states is not unique, among the set of which we find that the minimal one and its QSL can decrease more steeply by adjusting the coupling strength of the dissipator, which thus provides potential improvements of efficiency in many quantum physics and quantum information areas. PMID:26565062

  16. Driver assist behaviors for high-speed small UGVs

    NASA Astrophysics Data System (ADS)

    Yamauchi, Brian

    2011-05-01

    Currently deployed small UGVs operate at speeds up to around 6 mph and have proven their usefulness in explosives ordnance disposal (EOD) missions. As part of the TARDEC-funded Stingray Project, iRobot is investigating techniques to increase the speed of small UGVs so they can be useful in a wider range of missions, such as high-speed reconnaissance and infantry assault missions. We have developed a prototype Stingray PackBot, using wheels rather than tracks, that is capable of traveling at speeds up to 18 mph. A key issue when traveling at such speeds is how to maintain stability during sharp turns and over rough terrain. We are developing driver assist behaviors that will provide dynamic stability control for high-speed small UGVs using techniques such as dynamic weight shifting to limit oversteer and understeer. These driver assist behaviors will enable operators to use future high-speed small UGVs in high optempo infantry missions and keep warfighters out of harm's way.

  17. MPH: A library for distributed multi-component environment

    SciTech Connect

    Ding, Chris H.Q.; He, Yun

    2001-06-01

    Many current large and complex HPC applications are based on semi-independent program components developed by different groups or for different purposes. On distributed memory parallel supercomputers, how to perform component-name registration and initialize communications between independent components are among the first critical steps in establishing a distributed multi-component environment. Here we describe MPH, a multi-component handshaking library that resolves these tasks in a convenient and consistent way. MPH uses MPI for high performance and supports many PVM functionality. It supports two major parallel integration mechanism: multi-component multi-executable (MCME) and multi-component single-executable (MCME). It is a simple, easy-to-use module for developing practical codes, or as basis for larger software tools/frameworks.

  18. MPH: A library for distributed multi-component environment

    SciTech Connect

    Ding, Chris H.Q.; He, Yun

    2001-06-01

    Many current large and complex HPC applications are based on semi-independent program components developed by different groups or for different purposes. On distributed memory parallel supercomputers, how to perform component-name registration and initialize communications between independent components are among the first critical steps in establishing a distributed multi-component environment. Here we describe MPH, a multi-component handshaking library that resolves these tasks in a convenient and consistent way. MPH uses MPI for high performance and supports many PVM functionality. It supports two major parallel integration mechanism: multi-component multi-executable (MCME) and multi-component single-executable (MCME). It is a simple, easy-to-use module for developing practical codes, or as basis for larger software tools/frameworks.

  19. Quantum speed limits in open systems: Non-Markovian dynamics without rotating-wave approximation

    PubMed Central

    Sun, Zhe; Liu, Jing; Ma, Jian; Wang, Xiaoguang

    2015-01-01

    We derive an easily computable quantum speed limit (QSL) time bound for open systems whose initial states can be chosen as either pure or mixed states. Moreover, this QSL time is applicable to either Markovian or non-Markovian dynamics. By using of a hierarchy equation method, we numerically study the QSL time bound in a qubit system interacting with a single broadened cavity mode without rotating-wave, Born and Markovian approximation. By comparing with rotating-wave approximation (RWA) results, we show that the counter-rotating terms are helpful to increase evolution speed. The problem of non-Markovianity is also considered. We find that for non-RWA cases, increasing system-bath coupling can not always enhance the non-Markovianity, which is qualitatively different from the results with RWA. When considering the relation between QSL and non-Markovianity, we find that for small broadening widths of the cavity mode, non-Markovianity can increase the evolution speed in either RWA or non-RWA cases, while, for larger broadening widths, it is not true for non-RWA cases. PMID:25676589

  20. Optimization of cold rolling process parameters in order to increasing rolling speed limited by chatter vibrations

    PubMed Central

    Heidari, Ali; Forouzan, Mohammad R.

    2012-01-01

    Chatter has been recognized as major restriction for the increase in productivity of cold rolling processes, limiting the rolling speed for thin steel strips. It is shown that chatter has close relation with rolling conditions. So the main aim of this paper is to attain the optimum set points of rolling to achieve maximum rolling speed, preventing chatter to occur. Two combination methods were used for optimization. First method is done in four steps: providing a simulation program for chatter analysis, preparing data from simulation program based on central composite design of experiment, developing a statistical model to relate system tendency to chatter and rolling parameters by response surface methodology, and finally optimizing the process by genetic algorithm. Second method has analogous stages. But central composite design of experiment is replaced by Taguchi method and response surface methodology is replaced by neural network method. Also a study on the influence of the rolling parameters on system stability has been carried out. By using these combination methods, new set points were determined and significant improvement achieved in rolling speed. PMID:25685398

  1. Hala Azzam, PhD, MPH | Division of Cancer Prevention

    Cancer.gov

    Dr. Hala Azzam is a Cancer Epidemiologist in the Cancer Prevention Fellowship Program (CPFP) in the Division of Cancer Prevention within the National Cancer Institute. She received her Bachelor's degree in molecular biology from Kings College London University, her PhD in anatomy and cell biology from Georgetown University Lombardi Cancer Center, and her MPH in epidemiology from Johns Hopkins University. She is also a CPFP alumna. |

  2. A Sub-30 mpH Resolution Thin Film Transistor-Based Nanoribbon Biosensing Platform.

    PubMed

    Zeimpekis, Ioannis; Papadimitriou, Konstantinos I; Sun, Kai; Hu, Chunxiao; Ashburn, Peter; Morgan, Hywel; Prodromakis, Themistoklis

    2017-09-01

    We present a complete biosensing system that comprises a Thin Film Transistor (TFT)-based nanoribbon biosensor and a low noise, high-performance bioinstrumentation platform, capable of detecting sub-30 mpH unit changes, validated by an enzymatic biochemical reaction. The nanoribbon biosensor was fabricated top-down with an ultra-thin (15 nm) polysilicon semiconducting channel that offers excellent sensitivity to surface potential changes. The sensor is coupled to an integrated circuit (IC), which combines dual switched-capacitor integrators with high precision analog-to-digital converters (ADCs). Throughout this work, we employed both conventional pH buffer measurements as well as urea-urease enzymatic reactions for benchmarking the overall performance of the system. The measured results from the urea-urease reaction demonstrate that the system can detect urea in concentrations as low as 25 μM, which translates to a change of 27 mpH, according to our initial pH characterisation measurements. The attained accuracy and resolution of our system as well as its low-cost manufacturability, high processing speed and portability make it a competitive solution for applications requiring rapid and accurate results at remote locations; a necessity for Point-of-Care (POC) diagnostic platforms.

  3. Oxygen delivery does not limit peak running speed during incremental downhill running to exhaustion.

    PubMed

    Liefeldt, G; Noakes, T D; Dennis, S C

    1992-01-01

    Oxygen consumption (VO2), ventilation (VI), respiratory exchange ratio (R), stride frequency and blood lactate concentrations were measured continuously in nine trained athletes during two continuous incremental treadmill runs to exhaustion on gradients of either 0 degree or -3 degrees. Compared to the run at 0 degree gradient, the athletes reached significantly higher maximal treadmill velocities but significantly lower VO2, VI, R and peak blood lactate concentrations (P less than 0.001) during downhill running. These lower VO2 and blood lactate concentrations at exhaustion indicated that factors other than oxygen delivery limited maximal performance during the downhill run. In contrast, stride frequencies were similar at each treadmill velocity; the higher maximal speed during the downhill run was achieved with a significantly longer stride length (P less than 0.001); maximal stride frequency was the same between tests. Equivalent maximal stride frequencies suggested that factors determining the rate of lower limb stride recovery may have limited maximal running speed during downhill running and, possibly, also during horizontal running.

  4. Quantum speed limits of a qubit system interacting with a nonequilibrium environment

    NASA Astrophysics Data System (ADS)

    He, Zhi; Yao, Chun-Mei; Li, Li; Wang, Qiong

    2016-08-01

    The speed of evolution of a qubit undergoing a nonequilibrium environment with spectral density of general ohmic form is investigated. First we reveal non-Markovianity of the model, and find that the non-Markovianity quantified by information backflow of Breuer et al. [Phys. Rev. Lett. 103 210401 (2009)] displays a nonmonotonic behavior for different values of the ohmicity parameter s in fixed other parameters and the maximal non-Markovianity can be achieved at a specified value s. We also find that the non-Markovianity displays a nonmonotonic behavior with the change of a phase control parameter. Then we further discuss the relationship between quantum speed limit (QSL) time and non-Markovianity of the open-qubit system for any initial states including pure and mixed states. By investigation, we find that the QSL time of a qubit with any initial states can be expressed by a simple factorization law: the QSL time of a qubit with any qubit-initial states are equal to the product of the coherence of the initial state and the QSL time of maximally coherent states, where the QSL time of the maximally coherent states are jointly determined by the non-Markovianity, decoherence factor and a given driving time. Moreover, we also find that the speed of quantum evolution can be obviously accelerated in the wide range of the ohmicity parameter, i.e., from sub-Ohmic to Ohmic and super-Ohmic cases, which is different from the thermal equilibrium environment case. Project supported by the National Natural Science Foundation of China (Grants Nos. 61505053 and 61475045), the Natural Science Foundation of Hunan Province, China(Grant No. 2015JJ3092), the School Foundation from the Hunan University of Arts and Science (Grant No. 14ZD01), the Fund from the Key Laboratory of Photoelectric Information Integration and Optical Manufacturing Technology of Hunan Province, China, and the Construction Program of the Key Discipline in Hunan University of Arts and Science (Optics).

  5. Relationship between quantum speed limit time and memory time in a photonic-band-gap environment

    NASA Astrophysics Data System (ADS)

    Wang, J.; Wu, Y. N.; Mo, M. L.; Zhang, H. Z.

    2016-12-01

    Non-Markovian effect is found to be able to decrease the quantum speed limit (QSL) time, and hence to enhance the intrinsic speed of quantum evolution. Although a reservoir with larger degree of non-Markovianity may seem like it should cause smaller QSL times, this seemingly intuitive thinking may not always be true. We illustrate this by investigating the QSL time of a qubit that is coupled to a two-band photonic-band-gap (PBG) environment. We show how the QSL time is influenced by the coherent property of the reservoir and the band-gap width. In particular, we find that the decrease of the QSL time is not attributed to the increasing non-Markovianity, while the memory time of the environment can be seen as an essential reflection to the QSL time. So, the QSL time provides a further insight and sharper identification of memory time in a PBG environment. We also discuss a feasible experimental realization of our prediction.

  6. High-speed 3D digital image correlation vibration measurement: Recent advancements and noted limitations

    NASA Astrophysics Data System (ADS)

    Beberniss, Timothy J.; Ehrhardt, David A.

    2017-03-01

    A review of the extensive studies on the feasibility and practicality of utilizing high-speed 3 dimensional digital image correlation (3D-DIC) for various random vibration measurement applications is presented. Demonstrated capabilities include finite element model updating utilizing full-field 3D-DIC static displacements, modal survey natural frequencies, damping, and mode shape results from 3D-DIC are baselined against laser Doppler vibrometry (LDV), a comparison between foil strain gage and 3D-DIC strain, and finally the unique application to a high-speed wind tunnel fluid-structure interaction study. Results show good agreement between 3D-DIC and more traditional vibration measurement techniques. Unfortunately, 3D-DIC vibration measurement is not without its limitations, which are also identified and explored in this study. The out-of-plane sensitivity required for vibration measurement for 3D-DIC is orders of magnitude less than LDV making higher frequency displacements difficult to sense. Furthermore, the digital cameras used to capture the DIC images have no filter to eliminate temporal aliasing of the digitized signal. Ultimately DIC is demonstrated as a valid alternative means to measure structural vibrations while one unique application achieves success where more traditional methods would fail.

  7. Relationship between quantum speed limit time and memory time in a photonic-band-gap environment

    PubMed Central

    Wang, J.; Wu, Y. N.; Mo, M. L.; Zhang, H. Z.

    2016-01-01

    Non-Markovian effect is found to be able to decrease the quantum speed limit (QSL) time, and hence to enhance the intrinsic speed of quantum evolution. Although a reservoir with larger degree of non-Markovianity may seem like it should cause smaller QSL times, this seemingly intuitive thinking may not always be true. We illustrate this by investigating the QSL time of a qubit that is coupled to a two-band photonic-band-gap (PBG) environment. We show how the QSL time is influenced by the coherent property of the reservoir and the band-gap width. In particular, we find that the decrease of the QSL time is not attributed to the increasing non-Markovianity, while the memory time of the environment can be seen as an essential reflection to the QSL time. So, the QSL time provides a further insight and sharper identification of memory time in a PBG environment. We also discuss a feasible experimental realization of our prediction. PMID:28008937

  8. Fundamental High-Speed Limits in Single-Molecule, Single-Cell, and Nanoscale Force Spectroscopies.

    PubMed

    Amo, Carlos A; Garcia, Ricardo

    2016-07-26

    Force spectroscopy is enhancing our understanding of single-biomolecule, single-cell, and nanoscale mechanics. Force spectroscopy postulates the proportionality between the interaction force and the instantaneous probe deflection. By studying the probe dynamics, we demonstrate that the total force acting on the probe has three different components: the interaction, the hydrodynamic, and the inertial. The amplitudes of those components depend on the ratio between the resonant frequency and the frequency at which the data are measured. A force-distance curve provides a faithful measurement of the interaction force between two molecules when the inertial and hydrodynamic components are negligible. Otherwise, force spectroscopy measurements will underestimate the value of unbinding forces. Neglecting the above force components requires the use of frequency ratios in the 50-500 range. These ratios will limit the use of high-speed methods in force spectroscopy. The theory is supported by numerical simulations.

  9. Effects of vehicle-pedestrian interaction and speed limit on traffic performance of intersections

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Sun, Jian-Qiao

    2016-10-01

    The intersection model consisting of vehicle model, pedestrian model, pedestrian-vehicle interaction model and intersection rules has been presented in this paper. The well-established vehicle and pedestrian movement models in the literature are combined and applied to the intersection system with additional rules. Extensive numerical simulations with different scenarios are carried out. The effects of road speed limit, vehicle arrival rate, pedestrian regularity rate and vehicle rational rate on the intersection performance are quantitatively investigated. Three measures of the traffic performance are studied including transportation efficiency, energy economy and traffic safety. We have found that the energy economy can be achieved with the high transportation efficiency, and that the traffic safety is in conflict with the efficiency. Furthermore, we have found that the pedestrian interference makes the intersection performance worse, resulting in lower transportation efficiency, more energy consumptions and higher safety risk.

  10. Fundamental High-Speed Limits in Single-Molecule, Single-Cell, and Nanoscale Force Spectroscopies

    PubMed Central

    2016-01-01

    Force spectroscopy is enhancing our understanding of single-biomolecule, single-cell, and nanoscale mechanics. Force spectroscopy postulates the proportionality between the interaction force and the instantaneous probe deflection. By studying the probe dynamics, we demonstrate that the total force acting on the probe has three different components: the interaction, the hydrodynamic, and the inertial. The amplitudes of those components depend on the ratio between the resonant frequency and the frequency at which the data are measured. A force–distance curve provides a faithful measurement of the interaction force between two molecules when the inertial and hydrodynamic components are negligible. Otherwise, force spectroscopy measurements will underestimate the value of unbinding forces. Neglecting the above force components requires the use of frequency ratios in the 50–500 range. These ratios will limit the use of high-speed methods in force spectroscopy. The theory is supported by numerical simulations. PMID:27359243

  11. Drivers' compliance with speed limits: an application of the theory of planned behavior.

    PubMed

    Elliott, Mark A; Armitage, Christopher J; Baughan, Christopher J

    2003-10-01

    The theory of planned behavior (TPB; I. Ajzen, 1985) was applied to drivers' compliance with speed limits. Questionnaire data were collected for 598 drivers at 2 time points separated by 3 months. TPB variables, demographic information, and self-reported prior behavior were measured at Time 1, and self-reported subsequent behavior was measured at Time 2. In line with the TPB, attitude, subjective norm, and perceived control were positively associated with behavioral intention, and intention and perceived control were positively associated with subsequent behavior. TPB variables mediated the effects of age and gender on behavior. Prior behavior was found to moderate the perceived control-intention and perceived control-subsequent behavior relationships. Practical implications of the findings for road safety and possible avenues for further research are discussed.

  12. A common speed limit for RNA-cleaving ribozymes and deoxyribozymes.

    PubMed

    Breaker, Ronald R; Emilsson, Gail Mitchell; Lazarev, Denis; Nakamura, Shingo; Puskarz, Izabela J; Roth, Adam; Sudarsan, Narasimhan

    2003-08-01

    It is widely believed that the reason proteins dominate biological catalysis is because polypeptides have greater chemical complexity compared with nucleic acids, and thus should have greater enzymatic power. Consistent with this hypothesis is the fact that protein enzymes typically exhibit chemical rate enhancements that are far more substantial than those achieved by natural and engineered ribozymes. To investigate the true catalytic power of nucleic acids, we determined the kinetic characteristics of 14 classes of engineered ribozymes and deoxyribozymes that accelerate RNA cleavage by internal phosphoester transfer. Half approach a maximum rate constant of approximately 1 min(-1), whereas ribonuclease A catalyzes the same reaction approximately 80,000-fold faster. Additional biochemical analyses indicate that this commonly encountered ribozyme "speed limit" coincides with the theoretical maximum rate enhancement for an enzyme that uses only two specific catalytic strategies. These results indicate that ribozymes using additional catalytic strategies could be made that promote RNA cleavage with rate enhancements that equal those of proteins.

  13. Reaching the protein folding speed limit with large, sub-microsecond pressure jumps.

    PubMed

    Dumont, Charles; Emilsson, Tryggvi; Gruebele, Martin

    2009-07-01

    Biomolecules are highly pressure-sensitive, but their dynamics upon return to ambient pressure are often too fast to observe with existing approaches. We describe a sample-efficient method capable of large and very fast pressure drops (<1 nanomole, >2,500 atmospheres and <0.7 microseconds). We validated the method by fluorescence-detected refolding of a genetically engineered lambda repressor mutant from its pressure-denatured state. We resolved barrierless structure formation upon return to ambient pressure; we observed a 2.1 +/- 0.7 microsecond refolding time, which is very close to the 'speed limit' for proteins and much faster than the corresponding temperature-jump refolding of the same protein. The ability to experimentally perform a large and very fast pressure drop opens up a new region of the biomolecular energy landscape for atomic-level simulation.

  14. Inficon Transpector MPH Mass Spectrometer Random Vibration Test Report

    NASA Technical Reports Server (NTRS)

    Santiago-Bond, Jo; Captain, Janine

    2015-01-01

    The purpose of this test report is to summarize results from the vibration testing of the INFICON Transpector MPH100M model Mass Spectrometer. It also identifies requirements satisfied, and procedures used in the test. As a payload of Resource Prospector, it is necessary to determine the survivability of the mass spectrometer to proto-qualification level random vibration. Changes in sensitivity of the mass spectrometer can be interpreted as a change in alignment of the instrument. The results of this test will be used to determine any necessary design changes as the team moves forward with flight design.

  15. Peer Influence Predicts Speeding Prevalence Among Teenage Drivers

    PubMed Central

    Ouimet, Marie Claude; Chen, Rusan; Klauer, Sheila G.; Lee, Suzanne E.; Wang, Jing; Dingus, Thomas A.

    2012-01-01

    Objective This research examined the psychosocial and personality predictors of observed speeding among young drivers. Method. Survey and driving data were collected from 42 newly-licensed teenage drivers during the first 18 months of licensure. Speeding (i.e., driving 10 mph over the speed limit; about 16 km/h) was assessed by comparing speed data collected with recording systems installed in participants’ vehicles with posted speed limits. Questionnaire data collected at baseline were used to predict speeding rates using random effects regression analyses. For mediation analysis, data collected at baseline and at 6, 12, and 18 months after licensure were used. Results. Speeding was correlated with elevated g-force event rates, including hard braking and turning (r = 0.335, p < 0.05), but not with crashes and near crashes (r = 0.227; ns). Speeding prevalence increased over time. In univariate analyses speeding was predicted by day vs. night trips, higher sensation seeking, substance use, tolerance of deviance, susceptibility to peer pressure, and number of risky friends. In multivariate analyses the number of risky friends was the only significant predictor of speeding. Perceived risk was a significant mediator of the association between speeding and risky friends. Conclusion. The findings support the contention that social norms may influence teenage speeding behavior and this relationship may operate through perceived risk. PMID:23206513

  16. Modified quantum-speed-limit bounds for open quantum dynamics in quantum channels

    NASA Astrophysics Data System (ADS)

    Liu, Xin; Wu, Wei; Wang, Chao

    2017-05-01

    The minimal evolution time between two distinguishable states is of fundamental interest in quantum physics. Very recently Mirkin et al. [Phys. Rev. A 94, 052125 (2016), 10.1103/PhysRevA.94.052125] argued that some of the most common quantum-speed-limit (QSL) bounds which depend on the actual evolution time do not cleave to the essence of the QSL theory as they grow indefinitely but the final state is reached at a finite time in a damped Jaynes-Cummings model. In this paper, we thoroughly study this puzzling phenomenon. We find the inconsistent estimates will happen if and only if the limit of resolution of a calculation program is achieved, through which we propose that the nature of the inconsistency is not a violation of the essence of the QSL theory but an illusion caused by the finite precision in numerical simulations. We also present a generic method to overcome the inconsistent estimates and confirm its effectiveness in both amplitude-damping and phase-damping channels. Additionally, we show special cases which may restrict the QSL bound defined by "quantumness".

  17. Exploring the impact of once-daily OROS® methylphenidate (MPH) on symptoms and quality of life in children and adolescents with ADHD transitioning from immediate-release MPH.

    PubMed

    Kordon, Andreas; Stollhoff, Kirsten; Niederkirchner, Käte; Mattejat, Fritz; Rettig, Klaus; Schäuble, Barbara

    2011-09-01

    To explore the clinical and health-related quality of life (HRQoL) outcomes in children/adolescents with attention-deficit/hyperactivity disorder (ADHD) who required a therapy switch from immediate-release (IR) methylphenidate (MPH) and were initiated on Osmotic Release Oral System (OROS(®)) MPH. Prospective, noninterventional study including patients (aged 6-18 years) with a confirmed diagnosis of ADHD who transitioned from IR MPH to OROS(®) MPH based on medical needs. Patients were transitioned to OROS(®) MPH and were followed for 12 weeks. Attention-deficit/hyperactivity disorder symptoms, functional outcomes, HRQoL, and tolerability were assessed throughout the study. 598 patients entered the intention-to-treat analysis. The mean OROS(®) MPH starting dose was 29.5 ± 12.0 mg/day, increasing slightly to 33.5 ± 13.2 mg/day at final visit. Compared with baseline, there were significant (all P < 0.0001) symptomatic, functional, and HRQoL improvements after transitioning from IR MPH to OROS(®) MPH as assessed by the Conners' Parent Rating Scale (from 29.0 ± 10.5 to 19.5 ± 11.1), Children's Global Assessment Scale (by 11.0 ± 13.3), and Inventory for Assessing Quality of Life (ILC) LQ0-28 scores (parents' rating from 17.2 ± 3.9 to 19.4 ± 4.0; patients' rating from 18.7 ± 4.0 to 20.5 ± 3.9). Overall, no significant changes in quality of sleep or appetite were observed. More than 70% of parents and physicians rated the effectiveness of OROS(®) MPH as at least "good" and were at least "satisfied" with OROS(®) MPH. The most common treatment-emergent adverse events were insomnia and anorexia. No clinically relevant changes in body weight or vital signs were observed. In this naturalistic setting, transitioning from IR MPH to OROS(®) MPH, in patients who showed previously insufficient response and/or poor tolerability, was successful. Patients' and parents' HRQoL as well as burden of disease showed a clinically relevant improvement. OROS(®) MPH was

  18. Radio Frequency Performance Improvement with Drain Bias and Limiting Factors of 65-nm-Node Radio Frequency Metal-Oxide-Semiconductor Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Kao, Hsuan-ling; Lu, Chia-Ling; Chang, Yung-Cheng

    2009-01-01

    With the continuous down scaling of radio frequency metal-oxide-semiconductor field-effect transistors (RF MOSFETs) into a 65 nm node, the RF performance of unity-gain cutoff frequency ( fT), the maximum frequency of oscillation ( fmax), and the minimum noise figure (NFmin) show much smaller dependences on short-channel effects due to increases in drain current and transconductance (gm), which originate from the short-channel effects. We have studied the effect of drain bias on the RF performance of 65-nm-node MOSFETs. Both the fT and NFmin improve linearly with increasing drain voltage, in contrast with their independence on drain bias in longer-channel devices. Additionally, although fT improves continuously in sub-65-nm node devices, fmax and NFmin deteriorate more in 65-nm-node transistors than in 90-nm-node devices owing to a limiting parasitic effect.

  19. Characteristics and Use of Home Health Care by Men and Women Aged 65 and Over

    MedlinePlus

    ... April 18, 2012 Characteristics and Use of Home Health Care by Men and Women Aged 65 and Over ... and Roberto Valverde, M.P.H., Division of Health Care Statistics Abstract Objective —This report presents national estimates ...

  20. Limiting critical speed response on the SSME Alternate High Pressure Fuel Turbopump (ATD HPFTP) with bearing deadband

    NASA Astrophysics Data System (ADS)

    Goggin, David G.; Darden, J. M.

    1992-07-01

    Yammamoto (1954) described the influence of bearing deadband on the critical speed response of a rotor-bearing system. Practical application of these concepts to limit critical speed response of turbopump rotors is described. Nonlinear rotordynamic analyses are used to define the effect of bearing deadband and rotor unbalance on the Space Shuttle Main Engine Alternate High Pressure Fuel Turbopump. Analysis results are used with hot fire test data to verify the presence of a lightly damped critical speed within the operating speed range. With the proper control of rotor unbalance and bearing deadband, the response of this critical speed is reduced to acceptable levels without major design modifications or additional sources of damping.

  1. Limiting critical speed response on the SSME Alternate High Pressure Fuel Turbopump (ATD HPFTP) with bearing deadband

    NASA Technical Reports Server (NTRS)

    Goggin, David G.; Darden, J. M.

    1992-01-01

    Yammamoto (1954) described the influence of bearing deadband on the critical speed response of a rotor-bearing system. Practical application of these concepts to limit critical speed response of turbopump rotors is described. Nonlinear rotordynamic analyses are used to define the effect of bearing deadband and rotor unbalance on the Space Shuttle Main Engine Alternate High Pressure Fuel Turbopump. Analysis results are used with hot fire test data to verify the presence of a lightly damped critical speed within the operating speed range. With the proper control of rotor unbalance and bearing deadband, the response of this critical speed is reduced to acceptable levels without major design modifications or additional sources of damping.

  2. Modeling and analyzing traffic safety perceptions: An application to the speed limit reduction pilot project in Edmonton, Alberta.

    PubMed

    El-Basyouny, Karim; El-Bassiouni, Mohamed Yahia

    2013-03-01

    To address the speeding problem in residential areas, the City of Edmonton initiated a pilot project to reduce the posted speed limit from 50km/h to 40km/h within six residential communities. This paper investigates the community perceptions of traffic safety within the six pilot communities in two phases: prior to project initiation (pre-pilot) and following the end of the project (post-pilot). This objective was accomplished by analyzing the results of two random dialing telephone surveys comprising 300 residents each. A preliminary analysis showed compatible demographic configurations for the two samples and confirmed that the residents were aware of both the posted speed limits and the adopted speed management controls. For the confirmatory factor analysis (CFA), a two-group (pre-pilot and post-pilot) three-factor model was used to assess the residents' perceptions of the speeding behavior (Speeding), their concerns about traffic safety issues (Concerns), and their perceptions of traffic safety (Safety). Comparing the CFA results of the post-pilot survey versus those of the pre-pilot survey, it was evident that there was a significant decrease in Speeding and Concerns accompanied by a significant increase in Safety. A structural equations model (SEM) was also fitted to the data in order to assess the impact of Speeding and Concerns on Safety. The results showed that Concerns increase significantly with Speeding, and that both factors have significant negative impacts on Safety. However, while the impact of Concerns on Safety was direct, that of Speeding on Safety was largely indirect (i.e., mediated through Concerns). Overall, the multivariate analysis has demonstrated that the pilot project was successful in improving the residents' perceptions of traffic safety in their community. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  3. Taking larger timesteps with speed-limited particle-in-cell simulation

    NASA Astrophysics Data System (ADS)

    Werner, Gregory; Cary, John

    2015-11-01

    Particle-in-cell (PIC) simulation is often impractical because it includes too much unnecessary physics. For example, to avoid instability in many simulations the timestep must be small enough to resolve the plasma frequency, even if plasma oscillations do not play a significant role. Other methods (e.g., MHD/fluid and hybrid approaches) allow faster simulation, but often don't include enough physics. A new method, speed-limited PIC (SLPIC) simulation, offers kinetic simulation with an arbitrary-strength approximation tied to the timestep. With a small (standard PIC) timestep, SLPIC is identical to PIC, while a larger timestep (e.g., large compared to the inverse plasma frequency) results in the relaxation of fast particles over slower timescales. SLPIC is therefore useful in situations where the particle distribution functions change slowly compared to the timestep required by PIC. For example, SLPIC can simulate collisionless sheaths with a timestep hundreds of times larger than the inverse plasma frequency. SLPIC involves relatively isolated changes of a standard PIC code and poses no extra difficulties for parallelism; complexities of PIC, such as field solvers, collisions, and boundary conditions, carry over naturally to SLPIC with little change. This work is supported by NASA.

  4. Rated Voltage Enlargement for High-Speed PTC Current Limiter by Using a Series Transformer

    NASA Astrophysics Data System (ADS)

    Abubaker, Zawam; Maeyama, Mitsuaki

    In this paper, using Positive Temperature Coefficient (PTC) elements, we propose a simple repetitive high-speed PTC Current Limiter (PTC-CL) whose rated voltage is increased by using a series transformer (ST) at levels far beyond their intrinsic voltage rating. The PTC-CL consists of PTC resistors connected in series and in parallel to each winding of the ST. The PTC-CL was numerically studied by using the electro-magnetic transient program (EMTP) and the electrical equivalent model for PTC. The winding resistance effects and whether all of PTCs will trip or not under the fault current condition were studied. The experimental results in case of two PTCs, where the PTC element is rated (60V/40A), show that the sufficient voltage is applied on the non-tripped PTC even after another PTC trippd at first, and all PTCs of PTC-CL tripped within 0.2 ms where the fault current was suppressed from 1200 A to 52 A at rated voltage 120 V. But, the saturation current started to flow after 2 ms and reached above 1500 A because of the small size of the used core. In order to reduce it, RC components were proposed and the measurement results indicate that the saturation current can be eliminated adopting a suitable parameter for RC components.

  5. Effects of heterogeneous traffic with speed limit zone on the car accidents

    NASA Astrophysics Data System (ADS)

    Marzoug, R.; Lakouari, N.; Bentaleb, K.; Ez-Zahraouy, H.; Benyoussef, A.

    2016-06-01

    Using the extended Nagel-Schreckenberg (NS) model, we numerically study the impact of the heterogeneity of traffic with speed limit zone (SLZ) on the probability of occurrence of car accidents (Pac). SLZ in the heterogeneous traffic has an important effect, typically in the mixture velocities case. In the deterministic case, SLZ leads to the appearance of car accidents even in the low densities, in this region Pac increases with increasing of fraction of fast vehicles (Ff). In the nondeterministic case, SLZ decreases the effect of braking probability Pb in the low densities. Furthermore, the impact of multi-SLZ on the probability Pac is also studied. In contrast with the homogeneous case [X. Li, H. Kuang, Y. Fan and G. Zhang, Int. J. Mod. Phys. C 25 (2014) 1450036], it is found that in the low densities the probability Pac without SLZ (n = 0) is low than Pac with multi-SLZ (n > 0). However, the existence of multi-SLZ in the road decreases the risk of collision in the congestion phase.

  6. Quantum speed limit for a relativistic electron in a uniform magnetic field

    NASA Astrophysics Data System (ADS)

    Villamizar, D. V.; Duzzioni, E. I.

    2015-10-01

    We analyze the influence of relativistic effects on the minimum evolution time between two orthogonal states of a quantum system. Defining the initial state as a homogeneous superposition between two Hamiltonian eigenstates of an electron in a uniform magnetic field, we obtain a relation between the minimum evolution time and the displacement of the mean radial position of the electron wave packet. The quantum speed limit time is calculated for an electron dynamics described by Dirac and Schrödinger-Pauli equations considering different parameters, such as the strength of magnetic field and the linear momentum of the electron in the axial direction. We highlight that when the electron undergoes a region with extremely strong magnetic field the relativistic and nonrelativistic dynamics differ substantially, so that the description given by the Schrödinger-Pauli equation enables the electron to travel faster than c , which is prohibited by Einstein's theory of relativity. This approach allows a connection between the abstract Hilbert space and the space-time coordinates, besides the identification of the most appropriate quantum dynamics used to describe the electron motion.

  7. Methylphenidate (MPH) promotes visual cortical activation in healthy adults in a cued visuomotor task.

    PubMed

    Hodzhev, Yordan; Yordanova, Juliana; Diruf, Martin; Kratz, Oliver; Moll, Gunter H; Kolev, Vasil; Heinrich, Hartmut

    2012-11-01

    Seeking for the mechanisms by which methylphenidate (MPH) improves behavior has demonstrated that MPH modulates excitability in the primary motor cortex. However, little is known about the influence of MPH on top-down controlled mechanisms in the sensory domain. The present study explored the effects of MPH on the activation of visual cortices in healthy adults who performed a cued visuo-motor task in a double-blind placebo-controlled crossover design. Two distinct measures, posterior alpha power and occipital slow cortical potentials (SCPs), were used to reflect raise in excitability and attention-based activation of visual cortical areas. According to the results, performance parameters (reaction time, response variance and error rate) were not affected by MPH. At the neurophysiologic level reflected by reduced alpha power, MPH increased the overall excitability of the occipital cortex, but not the parietal cortex. Before the cued response, MPH reduced alpha power and increased SCPs only before right hand responses, mostly at the right occipital location. It can be concluded that in visuo-motor tasks, MPH has the potency of adjusting the background excitation/inhibition balance of visual areas. Additionally, MPH may raise the attention controlled activation of visual cortical regions, especially during increased response control.

  8. Biochemical studies of the Saccharomyces cerevisiae Mph1 helicase on junction-containing DNA structures

    PubMed Central

    Kang, Young-Hoon; Munashingha, Palinda Ruvan; Lee, Chul-Hwan; Nguyen, Tuan Anh; Seo, Yeon-Soo

    2012-01-01

    Saccharomyces cerevisiae Mph1 is a 3–5′ DNA helicase, required for the maintenance of genome integrity. In order to understand the ATPase/helicase role of Mph1 in genome stability, we characterized its helicase activity with a variety of DNA substrates, focusing on its action on junction structures containing three or four DNA strands. Consistent with its 3′ to 5′ directionality, Mph1 displaced 3′-flap substrates in double-fixed or equilibrating flap substrates. Surprisingly, Mph1 displaced the 5′-flap strand more efficiently than the 3′ flap strand from double-flap substrates, which is not expected for a 3–5′ DNA helicase. For this to occur, Mph1 required a threshold size (>5 nt) of 5′ single-stranded DNA flap. Based on the unique substrate requirements of Mph1 defined in this study, we propose that the helicase/ATPase activity of Mph1 play roles in converting multiple-stranded DNA structures into structures cleavable by processing enzymes such as Fen1. We also found that the helicase activity of Mph1 was used to cause structural alterations required for restoration of replication forks stalled due to damaged template. The helicase properties of Mph1 reported here could explain how it resolves D-loop structure, and are in keeping with a model proposed for the error-free damage avoidance pathway. PMID:22090425

  9. Comparison of a combination of upper extremity performance measures and usual gait speed alone for discriminating upper extremity functional limitation and disability in older women.

    PubMed

    Seino, Satoshi; Yabushita, Noriko; Kim, Mi-ji; Nemoto, Miyuki; Jung, Songee; Osuka, Yosuke; Okubo, Yoshiro; Matsuo, Tomoaki; Tanaka, Kiyoji

    2012-01-01

    Although usual gait speed (UGS) is considered an indicator of overall well-being, it is unclear whether upper extremity performance (UEP) measures provide a similar, additive contribution to functional status. We aimed to identify whether combining UEP measures can more accurately discriminate upper extremity functional limitation (UE limitation) and disability compared to UGS. We conducted a cross-sectional analysis on data from 322 community-dwelling older women, aged 65-96 years. Trained testers assessed UGS, and hand-grip strength (GRIP), functional reach (FR), back scratch, manipulating pegs (PEG), and moving beans with chopsticks as UEP measures. We assessed three functional statuses: UE limitation, activities of daily living (ADLs) and instrumental ADLs (IADLs) disabilities using self-reported questionnaires. Areas under the receiver operating characteristic curves (AUCs) were used to compare the discriminating power of UGS, with the individual and combined UEP measures for each status. Among UEP measures, only GRIP (AUC=0.68 for UE limitation, 0.81 for IADLs disability, and 0.84 for ADLs disability) could accurately discriminate each status as well as UGS (AUC=0.65, 0.83, and 0.91, respectively). Furthermore, UGS alone could discriminate UE limitation almost as well as the combination of GRIP, PEG, and FR (AUC=0.70). Combining other UEP measures did not help discriminate further. There were few advantages to combining UEP measures, and UGS or GRIP alone may suffice for assessing UE limitation and disability. However, the UGS should be the test of first choice, certainly more than GRIP, in routine assessment of functional limitation and disability, including UE limitation. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. The Impact of a Signalized Crosswalk on Traffic Speed and Street-Crossing Behaviors of Residents in an Underserved Neighborhood.

    PubMed

    Schultz, Courtney L; Sayers, Stephen P; Wilhelm Stanis, Sonja A; Thombs, Lori A; Thomas, Ian M; Canfield, Shannon M

    2015-10-01

    Infrastructure improvements such as pedestrian crosswalks that calm traffic and increase access to physical activity opportunities could alleviate important barriers to active living in underserved communities with outdated built environments. The purpose of this study was to explore how the built environment influences street-crossing behaviors and traffic speeds in a low-income neighborhood with barriers to active living in Columbia, Missouri. In 2013, a signalized pedestrian crosswalk and 400-ft-long median was constructed along a busy 5-lane, high-speed arterial highway linking low-income housing with a park and downtown areas. Data collection occurred prior to June 2012, and after June 2013, completion of the project at the intervention site and control site. Direct observation of street-crossing behaviors was performed at designated intersections/crosswalks or non-designated crossing points. Traffic volume and speed were captured using embedded magnetic traffic detectors. At the intervention site, designated crossings increased at the new crosswalk (p < 0.001), but not at non-designated crossings (p = 0.52) or designated crossings at intersections (p = 0.41). At the control site, there was no change in designated crossings (p = 0.94) or non-designated crossings (p = 0.79). Motor vehicles traveling above the speed limit of 35 mph decreased from 62,056 (46 %) to 46,256 (35 %) (p < 0.001) at the intervention site and increased from 57,891 (49 %) to 65,725 (59 %) (p < 0.001) at the control site. The installation of a signalized crosswalk facilitated an increase in safe street crossings and calmed traffic volume and speed in an underserved neighborhood. We believe these findings have significant public health implications that could be critical to advocacy efforts to improve infrastructure projects in similar communities.

  11. Galactorrhea Probably Related with Switching from Osmotic-release Oral System Methylphenidate (MPH) to Modified-release MPH: An Adolescent Case.

    PubMed

    Ekinci, Ozalp; Gunes, Serkan; Ekinci, Nuran

    2017-08-31

    Galactorrhea, as an adverse effect of psychotropic medications, usually develops due to high dose of antipsychotics. Selective serotonin reuptake inhibitors (SSRIs) have also been reported to be related to galactorrhea. To the best of our knowledge, no previous study reported galactorrhea with methylphenidate (MPH) use. Hereby, we report a case of an adolescent girl who developed galactorrhea after increasing his modifed-release oral MPH to 50 mg/day while under treatment of sertraline and very low dose haloperidol.

  12. Galactorrhea Probably Related with Switching from Osmotic-release Oral System Methylphenidate (MPH) to Modified-release MPH: An Adolescent Case

    PubMed Central

    Ekinci, Ozalp; Gunes, Serkan; Ekinci, Nuran

    2017-01-01

    Galactorrhea, as an adverse effect of psychotropic medications, usually develops due to high dose of antipsychotics. Selective serotonin reuptake inhibitors (SSRIs) have also been reported to be related to galactorrhea. To the best of our knowledge, no previous study reported galactorrhea with methylphenidate (MPH) use. Hereby, we report a case of an adolescent girl who developed galactorrhea after increasing his modifed-release oral MPH to 50 mg/day while under treatment of sertraline and very low dose haloperidol. PMID:28783939

  13. Control model design to limit DC-link voltage during grid fault in a dfig variable speed wind turbine

    NASA Astrophysics Data System (ADS)

    Nwosu, Cajethan M.; Ogbuka, Cosmas U.; Oti, Stephen E.

    2017-08-01

    This paper presents a control model design capable of inhibiting the phenomenal rise in the DC-link voltage during grid- fault condition in a variable speed wind turbine. Against the use of power circuit protection strategies with inherent limitations in fault ride-through capability, a control circuit algorithm capable of limiting the DC-link voltage rise which in turn bears dynamics that has direct influence on the characteristics of the rotor voltage especially during grid faults is here proposed. The model results so obtained compare favorably with the simulation results as obtained in a MATLAB/SIMULINK environment. The generated model may therefore be used to predict near accurately the nature of DC-link voltage variations during fault given some factors which include speed and speed mode of operation, the value of damping resistor relative to half the product of inner loop current control bandwidth and the filter inductance.

  14. Systems evaluation of high-speed rail for the Texas Triangle

    SciTech Connect

    Petersen, H.C.

    1985-01-01

    This dissertation describes and compares simulations of operation of different high speed rail technologies on alternative rights-of-way in the Texas Triangle which connect Dallas/Fort Worth, Houston, and San Antonio. Proposals for high speed rail on existing rights-of-way must consider geometric constraints. It was concluded that cross-sectional geometry would allow construction of a high-speed rail line along the majority of the rights-of-way. A microcomputer was used to apply the operations research technique of simulation to predict train operation over proposed routes on the Texas Triangle. The deterministic simulation program was used to investigate different types of high-speed-train technologies operating on interstate highway medians and the former Rock Island right-of-way. Results of the simulation runs demonstrated that comfort and curvature limitations prevented full utilization of speeds as high as 350 mph, and that lower speeds (around 200 mph) appear to be more appropriate, given the existing geometric constraints. The study concluded that high speed rail passenger service is technically feasible on existing rights-of-way in Texas.

  15. Quantum speed limit for a relativistic electron in the noncommutative phase space

    NASA Astrophysics Data System (ADS)

    Wang, Kang; Zhang, Yu-Fei; Wang, Qing; Long, Zheng-Wen; Jing, Jian

    2017-08-01

    The influence of the noncommutativity on the average speed of a relativistic electron interacting with a uniform magnetic field within the minimum evolution time is investigated. We find that it is possible for the wave packet of the electron to travel faster than the speed of light in vacuum because of the noncommutativity. It is a clear signature of violating Lorentz invariance in the noncommutative relativistic quantum mechanical region.

  16. Raised speed limits, case fatality and road deaths: a six year follow‐up using ARIMA models

    PubMed Central

    Friedman, Lee S; Barach, Paul; Richter, Elihu D

    2007-01-01

    Background In November 1993, the Israeli government increased the speed limit for all vehicles from 90 to 100 km per hour on a total of 115 km of its three major interurban highways. Design/Setting We use ARIMA time series intervention models to evaluate the effect of the raise in speed limit on fatalities, serious injuries, and case‐fatality for years 1988–1999. Motor vehicle crash data came from the Central Bureau of Statistics of Israel. Results Between January 1988 and December 1999, a total of 6029 persons were killed and 45 616 were seriously injured on roads in Israel. For all roads combined, the time series ARIMA model indicated that there were 4.69 more deaths per month (p<0.001), or 347 more than expected in the post‐intervention period. Case‐fatality rate (CFR) on all roads combined rose significantly (p<0.001). Modified case‐fatality rate (CFRS) showed an increase of 2.5 deaths per 100 serious casualties (p<0.001). Conclusions The impact of raised speed limits was immediate and sustained. The largest increase in deaths occurred on interurban roads but a spillover effect was observed on urban roads as well. The increases in deaths and case‐fatality rates persisted six years after the speed limit change despite major countermeasures and increasing congestion throughout the period of follow‐up. PMID:17567969

  17. Evaluation and reformulation of the maximum peak height algorithm (MPH) and application in a hypertrophic lagoon

    NASA Astrophysics Data System (ADS)

    Pitarch, Jaime; Ruiz-Verdú, Antonio; Sendra, María. D.; Santoleri, Rosalia

    2017-02-01

    We studied the performance of the MERIS maximum peak height (MPH) algorithm in the retrieval of chlorophyll-a concentration (CHL), using a matchup data set of Bottom-of-Rayleigh Reflectances (BRR) and CHL from a hypertrophic lake (Albufera de Valencia). The MPH algorithm produced a slight underestimation of CHL in the pixels classified as cyanobacteria (83% of the total) and a strong overestimation in those classified as eukaryotic phytoplankton (17%). In situ biomass data showed that the binary classification of MPH was not appropriate for mixed phytoplankton populations, producing also unrealistic discontinuities in the CHL maps. We recalibrated MPH using our matchup data set and found that a single calibration curve of third degree fitted equally well to all matchups regardless of how they were classified. As a modification to the former approach, we incorporated the Phycocyanin Index (PCI) in the formula, thus taking into account the gradient of phytoplankton composition, which reduced the CHL retrieval errors. By using in situ biomass data, we also proved that PCI was indeed an indicator of cyanobacterial dominance. We applied our recalibration of the MPH algorithm to the whole MERIS data set (2002-2012). Results highlight the usefulness of the MPH algorithm as a tool to monitor eutrophication. The relevance of this fact is higher since MPH does not require a complete atmospheric correction, which often fails over such waters. An adequate flagging or correction of sun glint is advisable though, since the MPH algorithm was sensitive to sun glint.

  18. MPH program adaptability in a competitive marketplace: the case for continued assessment.

    PubMed

    Caron, Rosemary M; Tutko, Holly

    2010-06-01

    In the last several years, the number of Master of Public Health (MPH) programs has increased rapidly in the US. As such, MPH programs, particularly smaller-sized ones, need to critically examine how their programs are meeting the needs and preferences of local public health practitioners. To assist in this necessity, the University of New Hampshire conducted a comprehensive educational assessment of its effectiveness as a smaller-sized, accredited MPH program. The aim of the assessment was to review the MPH program from the perspective of all stakeholders and then to agree on changes that would contribute to the fulfillment of the program's mission, as well as improve program quality and reach. The program's stakeholders examined the following components: policy development and implementation; target audience; marketing strategies; marketplace position; delivery model; curriculum design; and continuing education. Though assessment activities explored a wide array of program attributes, target audience, curriculum design, and delivery strategy presented significant challenges and opportunities for our smaller MPH Program to remain competitive. The effort put forth into conducting an in-depth assessment of the core components of our program also allowed for a comparison to the increasing number of MPH programs developing regionally. Since public health practice is changing and the education of public health practitioners must be adaptable, we propose that a routine assessment of an institution's MPH program could not only meet this need but also assist with keeping smaller, unbranded MPH programs competitive in a burgeoning marketplace.

  19. Breaking the speed limit--comparative sprinting performance of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta)

    USGS Publications Warehouse

    Castro-Santos, Theodore; Sanz-Ronda, Francisco Javier; Ruiz-Legazpi, Jorge

    2013-01-01

    Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body lengths·s−1. These speeds far exceed previously published observations for any salmonid species and contribute to the mounting evidence that commonly accepted estimates of swimming performance are low. Brook trout demonstrated two distinct modes in the relationship between swim speed and fatigue time, similar to the shift from prolonged to sprint mode described by other authors, but in this case occurring at speeds > 19 body lengths·s−1. This is the first demonstration of multiple modes of sprint swimming at such high swim speeds. Neither species optimized for distance maximization, however, indicating that physiological limits alone are poor predictors of swimming performance. By combining distributions of volitional swim speeds with endurance, we were able to account for >80% of the variation in distance traversed by both species.

  20. Peer influence predicts speeding prevalence among teenage drivers.

    PubMed

    Simons-Morton, Bruce G; Ouimet, Marie Claude; Chen, Rusan; Klauer, Sheila G; Lee, Suzanne E; Wang, Jing; Dingus, Thomas A

    2012-12-01

    Preventing speed-related crashes could reduce costs and improve efficiency in the transportation industry. This research examined the psychosocial and personality predictors of observed speeding among young drivers. Survey and driving data were collected from 42 newly-licensed teenage drivers during the first 18months of licensure. Speeding (i.e., driving 10mph over the speed limit; about 16km/h) was assessed by comparing speed data collected with recording systems installed in participants' vehicles with posted speed limits. Speeding was correlated with elevated g-force event rates (r=0.335, pb0.05), increased over time, and predicted by day vs. night trips, higher sensation seeking, substance use, tolerance of deviance, susceptibility to peer pressure, and number of risky friends. Perceived risk was a significant mediator of the association between speeding and risky friends. The findings support the contention that social norms may influence teenage speeding behavior and this relationship may operate through perceived risk. Copyright © 2012 National Safety Council and Elsevier Ltd. All rights reserved.

  1. Relationship of clinic-based gait speed measurement to limitations in community-based activities in older adults.

    PubMed

    Verghese, Joe; Wang, Cuiling; Holtzer, Roee

    2011-05-01

    To examine the ability of clinic-based assessments of gait speed to capture limitations in a broad range of home- and community-based activities. Cross-sectional study. Community-based aging cohort study. Community-residing subjects (N=655; 61% women; age ≥70y; mean, 80.4y). None. Limitations on 3 gait-related activities of daily living (walking inside home, climbing up and down stairs) and 6 motor-based but gait-independent activities (bathing, dressing, getting up from a chair, toileting, shopping, using public transportation). Gait speed was associated with the presence of self-reported difficulty for all 3 home-based activities that were directly gait related and 5 of 6 motor-based activities. Gait speed of 1m/s or less was associated with increased risk for limitations on at least 1 of the 9 selected activities (odds ratio, 3.21; 95% confidence interval, 2.24-4.58; P<.001). Gait speed measured in clinical settings has ecologic validity as a clinical marker of functional status in older adults for use in clinical and research settings. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  2. Some limitations in applying classical EHD film thickness formulas to a high-speed bearing

    NASA Technical Reports Server (NTRS)

    Coy, J. J.; Zaretsky, E. V.

    1980-01-01

    Elastohydrodynamic film thickness was measured for a 20-mm ball bearing using the capacitance technique. The bearing was thrust loaded to 90, 448, and 778 N. The corresponding maximum stresses on the inner race were 1.28, 2.09, and 2.45 GPa. Test speeds ranged from 400 to 14,000 rpm. Film thickness measurements were taken with four different lubricants: (a) synthetic paraffinic, (b) synthetic paraffinic with additives, (c) neopentylpolyol (tetra) ester meeting MIL-L-23699A specifications, and (d) synthetic cycloaliphatic hydrocarbon traction fluid. The test bearing was mist lubricated. Test temperatures were 300, 338, and 393 K. The measured results were compared to theoretical predictions using the formulas of Grubin, Archard and Cowking, Dowson and Higginson, and Hamrock and Dowson. There was good agreement with theory at low dimensionless speed, but the film was much smaller than theory predicts at higher speeds. This was due to kinematic starvation and inlet shear heating effects.

  3. Some limitations in applying classical EHD film thickness formulas to a high-speed bearing

    NASA Technical Reports Server (NTRS)

    Coy, J. J.; Zaretsky, E. V.

    1980-01-01

    Elastohydrodynamic film thickness was measured for a 20-mm ball bearing using the capacitance technique. The bearing was thrust loaded to 90, 448, and 778 N. The corresponding maximum stresses on the inner race were 1.28, 2.09, and 2.45 GPa. Test speeds ranged from 400 to 14,000 rpm. Film thickness measurements were taken with four different lubricants: (a) synthetic paraffinic, (b) synthetic paraffinic with additives, (c) neopentylpolyol (tetra) ester meeting MIL-L-23699A specifications, and (d) synthetic cycloaliphatic hydrocarbon traction fluid. The test bearing was mist lubricated. Test temperatures were 300, 338, and 393 K. The measured results were compared to theoretical predictions using the formulas of Grubin, Archard and Cowking, Dowson and Higginson, and Hamrock and Dowson. There was good agreement with theory at low dimensionless speed, but the film was much smaller than theory predicts at higher speeds. This was due to kinematic starvation and inlet shear heating effects.

  4. Effect Of Platooning on Fuel Consumption of Class 8 Vehicles Over a Range of Speeds, Following Distances, and Mass

    SciTech Connect

    Lammert, M. P.; Duran, A.; Diez, J.; Burton, K.; Nicholson, A.

    2014-10-01

    This research project evaluates fuel consumption results of two Class 8 tractor-trailer combinations platooned together compared to their standalone fuel consumption. A series of ten modified SAE Type II J1321 fuel consumption track tests were performed to document fuel consumption of two platooned vehicles and a control vehicle at varying steady-state speeds, following distances, and gross vehicle weights (GVWs). The steady-state speeds ranged from 55 mph to 70 mph, the following distances ranged from a 20-ft following distance to a 75-ft following distance, and the GVWs were 65K lbs and 80K lbs. All tractors involved had U.S. Environmental Protection Agency (EPA) SmartWay-compliant aerodynamics packages installed, and the trailers were equipped with side skirts. Effects of vehicle speed, following distance, and GVW on fuel consumption were observed and analyzed. The platooning demonstration system used in this study consisted of radar systems, Dedicated Short-Range Communication (DSRC) vehicle-to-vehicle (V2V) communications, vehicle braking and torque control interface, cameras and driver displays. The lead tractor consistently demonstrated an improvement in average fuel consumption reduction as following distance decreased, with results showing 2.7% to 5.3% fuel savings at a GVW of 65k. The trailing vehicle achieved fuel consumption savings ranging from 2.8% to 9.7%; tests during which the engine cooling fan did not operate achieved savings of 8.4% to 9.7%. 'Team' fuel savings, considering the platooned vehicles as one, ranged from 3.7% to 6.4%, with the best combined result being for 55 mph, 30-ft following distance, and 65k GVW.

  5. Suppressor of cytokine signaling 1 (SOCS1) limits NFkappaB signaling by decreasing p65 stability within the cell nucleus.

    PubMed

    Strebovsky, Julia; Walker, Patrick; Lang, Roland; Dalpke, Alexander H

    2011-03-01

    Suppressor of cytokine signaling (SOCS) proteins are inhibitors of cytoplasmic Janus kinases (Jak) and signal transducer and activator of transcription (STAT) signaling pathways. Previously the authors surprisingly observed that SOCS1 translocated into the nucleus, which was because of the presence of a nuclear localization sequence. This report now hypothesizes that SOCS1 mediates specific functions within the nuclear compartment because it is instantly transported into the nucleus, as shown by photoactivation and live cell imaging in human HEK293 cells. The NFκB component p65 is identified as an interaction partner for SOCS1 but not for other members of the SOCS family. SOCS1 bound to p65 only within the nucleus. By means of its SOCS box domain, SOCS1 operated as a ubiquitin ligase, leading to polyubiquitination and proteasomal degradation of nuclear p65. Thus, SOCS1 limited prolonged p65 signaling and terminated expression of NFκB inducible genes. Using mutants that lack either nuclear translocation or a functional SOCS box, this report identifies genes that are regulated in a manner dependent on the nuclear availability of SOCS1. Data show that beyond its receptor-proximal function in Jak/STAT signaling, SOCS1 also regulates the duration of NFκB signaling within the cell nucleus, thus exerting a heretofore unrecognized function.

  6. Effects of Implementation Intentions on the Self-Reported Frequency of Drivers' Compliance with Speed Limits

    ERIC Educational Resources Information Center

    Elliott, Mark A.; Armitage, Christopher J.

    2006-01-01

    This study tested the efficacy of implementation intentions in the context of drivers' speeding behavior. Participants (N = 300) completed self-report measures of goal intention and behavior, and they were randomly assigned to an experimental condition, which required them to specify an implementation intention, or a control condition. One month…

  7. Speed Limits: Orientation and Semantic Context Interactions Constrain Natural Scene Discrimination Dynamics

    ERIC Educational Resources Information Center

    Rieger, Jochem W.; Kochy, Nick; Schalk, Franziska; Gruschow, Marcus; Heinze, Hans-Jochen

    2008-01-01

    The visual system rapidly extracts information about objects from the cluttered natural environment. In 5 experiments, the authors quantified the influence of orientation and semantics on the classification speed of objects in natural scenes, particularly with regard to object-context interactions. Natural scene photographs were presented in an…

  8. 76 FR 78 - Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter Device

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-03

    ... for rulemaking, one submitted by the American Trucking Associations and the other submitted by Road...: Background On October 20, 2006, the American Trucking Associations (ATA) submitted a petition to the National... a 15-20 revolutions per mile difference which will affect the actual top speed of the truck with a...

  9. Effects of Implementation Intentions on the Self-Reported Frequency of Drivers' Compliance with Speed Limits

    ERIC Educational Resources Information Center

    Elliott, Mark A.; Armitage, Christopher J.

    2006-01-01

    This study tested the efficacy of implementation intentions in the context of drivers' speeding behavior. Participants (N = 300) completed self-report measures of goal intention and behavior, and they were randomly assigned to an experimental condition, which required them to specify an implementation intention, or a control condition. One month…

  10. Limited synapse overproduction can speed development but sometimes with long-term energy and discrimination penalties.

    PubMed

    Ju, Harang; Colbert, Costa M; Levy, William B

    2017-09-22

    Neural circuit development requires that synapses be formed between appropriate neurons. In addition, for a hierarchical network, successful development involves a sequencing of developmental events. It has been suggested that one mechanism that helps speed up development of proper connections is an early overproduction of synapses. Using a computational model of synapse development, such as adaptive synaptogenesis, it is possible to study such overproduction and its role in speeding up development; it is also possible to study other outcomes of synapse overproduction that are seemingly new to the literature. With a fixed number of neurons, adaptive synaptogenesis can control the speed of synaptic development in two ways: by altering the rate constants of the adaptive processes or by altering the initial number of rapidly but non-selectively accrued synapses. Using either mechanism, the simulations reveal that synapse overproduction appears as an unavoidable concomitant of rapid adaptive synaptogenesis. However, the shortest development times, which always produces the greatest amount of synapse overproduction, reduce adult performance by three measures: energy-use, discrimination-error-rates, and proportional neuron allocation. Thus, the results here lead to the hypothesis that the observed speed of neural network development represents a particular inter-generational compromise, quick development benefits parental fecundity while slow development benefits offspring fecundity.

  11. Effects of vehicle power on passenger vehicle speeds.

    PubMed

    McCartt, Anne T; Hu, Wen

    2017-07-04

    During the past 2 decades, there have been large increases in mean horsepower and the mean horsepower-to-vehicle weight ratio for all types of new passenger vehicles in the United States. This study examined the relationship between travel speeds and vehicle power, defined as horsepower per 100 pounds of vehicle weight. Speed cameras measured travel speeds and photographed license plates and drivers of passenger vehicles traveling on roadways in Northern Virginia during daytime off-peak hours in spring 2013. The driver licensing agencies in the District of Columbia, Maryland, and Virginia provided vehicle information numbers (VINs) by matching license plate numbers with vehicle registration records and provided the age, gender, and ZIP code of the registered owner(s). VINs were decoded to obtain the curb weight and horsepower of vehicles. The study focused on 26,659 observed vehicles for which information on horsepower was available and the observed age and gender of drivers matched vehicle registration records. Log-linear regression estimated the effects of vehicle power on mean travel speeds, and logistic regression estimated the effects of vehicle power on the likelihood of a vehicle traveling over the speed limit and more than 10 mph over the limit. After controlling for driver characteristics, speed limit, vehicle type, and traffic volume, a 1-unit increase in vehicle power was associated with a 0.7% increase in mean speed, a 2.7% increase in the likelihood of a vehicle exceeding the speed limit by any amount, and an 11.6% increase in the likelihood of a vehicle exceeding the limit by 10 mph. All of these increases were highly significant. Speeding persists as a major factor in crashes in the United States. There are indications that travel speeds have increased in recent years. The current findings suggest the trend toward substantially more powerful vehicles may be contributing to higher speeds. Given the strong association between travel speed and crash

  12. Mte1 interacts with Mph1 and promotes crossover recombination and telomere maintenance

    PubMed Central

    Silva, Sonia; Altmannova, Veronika; Luke-Glaser, Sarah; Henriksen, Peter; Gallina, Irene; Yang, Xuejiao; Choudhary, Chunaram; Luke, Brian; Krejci, Lumir

    2016-01-01

    Mph1 is a member of the conserved FANCM family of DNA motor proteins that play key roles in genome maintenance processes underlying Fanconi anemia, a cancer predisposition syndrome in humans. Here, we identify Mte1 as a novel interactor of the Mph1 helicase in Saccharomyces cerevisiae. In vitro, Mte1 (Mph1-associated telomere maintenance protein 1) binds directly to DNA with a preference for branched molecules such as D loops and fork structures. In addition, Mte1 stimulates the helicase and fork regression activities of Mph1 while inhibiting the ability of Mph1 to dissociate recombination intermediates. Deletion of MTE1 reduces crossover recombination and suppresses the sensitivity of mph1Δ mutant cells to replication stress. Mph1 and Mte1 interdependently colocalize at DNA damage-induced foci and dysfunctional telomeres, and MTE1 deletion results in elongated telomeres. Taken together, our data indicate that Mte1 plays a role in regulation of crossover recombination, response to replication stress, and telomere maintenance. PMID:26966248

  13. Quenching a quantum critical state by the order parameter: Dynamical quantum phase transitions and quantum speed limits

    NASA Astrophysics Data System (ADS)

    Heyl, Markus

    2017-02-01

    Quantum critical states exhibit strong quantum fluctuations and are therefore highly susceptible to perturbations. In this Rapid Communication we study the dynamical stability against a sudden coupling to these strong fluctuations by quenching the order parameter of the underlying transition. Such a quench can generate superextensive energy fluctuations. This leads to a dynamical quantum phase transition (DQPT) with nonanalytic real-time behavior in the resulting decay of the initial state. By establishing a general connection between DQPTs and quantum speed limits, this allows us to obtain a quantum speed limit with unconventional system-size dependence. These findings are illustrated for the one-dimensional and the infinitely connected transverse-field Ising model. The main concepts, however, are general and can be applied also to other critical states. An outlook is given on the implications of superextensive energy fluctuations on potential restricted thermalization despite nonintegrability.

  14. The limits of modifying migration speed to adjust to climate change

    NASA Astrophysics Data System (ADS)

    Schmaljohann, Heiko; Both, Christiaan

    2017-08-01

    Predicting the range of variation over which organisms can adjust to environmental change is a major challenge in ecology. This is exemplified in migratory birds which experience changes in different habitats throughout the annual cycle. Earlier studies showed European population trends declining strongest in migrant species with least adjustment in spring arrival time. Thus, the increasing mismatches with other trophic levels in seasonal breeding areas probably contribute to their large-scale decline. Here we quantify the potential range of adjusting spring arrival dates through modifying migration speeds by reviewing 49 tracking studies. Among-individual variation in migration speed was mainly determined by the relatively short stop-over duration. Assuming this population response reflects individual phenotypic plasticity, we calculated the potential for phenotypic plasticity to speed-up migration by reducing stop-over duration. Even a 50% reduction would lead to a mere two-day advance in arrival, considering adjustments on the final 2,000 km of the spring journey. Hence, in contrast to previous studies, flexibility in the major determinant of migration duration seems insufficient to adjust to ongoing climate change, and is unlikely to explain some of the observed arrival advancements in long-distance migrants.

  15. The Effectiveness at High Speeds of a 20-Percent-chord Plain Trailing-edge Flap on the NACA 65-210 Airfoil Section

    NASA Technical Reports Server (NTRS)

    Stivers, Louis S., Jr.

    1947-01-01

    An analysis has been made of the lift-control effectiveness of a 20-percent-chord plain trailing-edge flap on the NACA 65-210 airfoil section from section lift-coefficient data obtained at Mach numbers from 0.3 to 0.875. In addition, the effectiveness of the plain flap as a lift-control device has been compared with the corresponding effectiveness of both a spoiler and a dive-recovery flag on the INCA 65-210 airfoil section.

  16. Design and testing of a high-speed treadmill to measure ground reaction forces at the limit of human gait.

    PubMed

    Bundle, Matthew W; Powell, Michael O; Ryan, Laurence J

    2015-09-01

    Investigations focused on the gait and physiological limits of human speed have been on-going for more than a century. However, due to measurement limitation a kinetic understanding of the foot-ground collision and how these dynamics differ between individuals to confer speed and limit gait has only recently begun to come forth. Therefore, we designed and tested an instrumented high-speed force treadmill to measure the forces occurring at the limits of human performance. The treadmill was designed to maximize flexural stiffness and natural frequency by using a honeycomb sandwich panel as the bed surface and a flexible drive shaft between the drive roller and servo motor to reduce the mass of the supported elements which contribute to the system's response frequency. The functional performance of the force treadmill met or exceeded the measurement criteria established for ideal force plates: high natural frequency (z-axis = 113 Hz), low crosstalk between components of the force (Fx/Fz = 0.0020[SD = 0.0010]; Fy/Fz = 0.0016[SD = 0.0003]), a linear response (R(2) > 0.999) for loading with known weights (range: 44-3857 N), and an accuracy of 2.5[SD = 1.7] mm and 2.8[SD = 1.5] mm in the x and y-axes, respectively, for the point of force application. In dynamic testing at running speeds up to 10 m s(-1), the measured durations and magnitudes of force application were similar between the treadmill and over-ground running using a force platform. This design provides a precise instrumented treadmill capable of recording multi-axis ground reaction forces applied during the foot ground contacts of the fastest men and animals known to science.

  17. Multi Program-Components Handshaking (MPH) Utility Version 3 User's Manual

    SciTech Connect

    He, Yun; Ding, Chris H.Q.

    2002-06-20

    MPH version 2 combines all features of MPH version 1, unifies the interfaces, and provides more flexible components integration/execution modes. In a distributed multi-component environment, each executable resides on a set of SMP nodes. Components within an executable may overlap on different nodes or processors. MPH Version 2 contains the following functionality: component name registration; resource allocation; multi-component single executable, multi-component multi-executable, etc.; inter-component communication; inquiry on the multi-component environment; and standard in/out redirect.

  18. Multi Program-Components Handshaking (MPH) Utility Version 3 User's Manual

    SciTech Connect

    He, Yun; Ding, Chris H.Q.

    2002-06-20

    MPH version 2 combines all features of MPH version 1, unifies the interfaces, and provides more flexible components integration/execution modes. In a distributed multi-component environment, each executable resides on a set of SMP nodes. Components within an executable may overlap on different nodes or processors. MPH Version 2 contains the following functionality: component name registration; resource allocation; multi-component single executable, multi-component multi-executable, etc.; inter-component communication; inquiry on the multi-component environment; and standard in/out redirect.

  19. Some limitations in applying classical EHD film-thickness formulae to a high-speed bearing

    NASA Technical Reports Server (NTRS)

    Coy, J. J.; Zaretsky, E. V.

    1980-01-01

    Elastohydrodynamic film thickness was measured for a 20 mm ball bearing using the capacitance technique. The bearing was thrust loaded to 90, 448, and 778 N. The corresponding maximum stresses on the inner race were 1.28, 2.09, and 2.45 GPa. Test speeds ranged from 400 to 14,000 rpm. Film thickness measurements were taken with four different lubricants: (1) synthetic paraffinic; (2) synthetic paraffinic with additives; (3) neopentylpolyol (tetra) ester; and (4) synthetic cycloaliphatic hydrocarbon traction fluid. The test bearing was mist lubricated. Test temperatures were 300, 338, and 393 K. The measured results were compared to theoretical predictions and are presented.

  20. Symptom control in children and adolescents with attention-deficit/hyperactivity disorder on switching from immediate-release MPH to OROS MPH Results of a 3-week open-label study.

    PubMed

    Remschmidt, H; Hoare, P; Ettrich, C; Rothenberger, A; Santosh, P; Schmidt, M; Spender, Q; Tamhne, R; Thompson, M; Tinline, C; Trott, G E; Medori, R

    2005-09-01

    The aim of this study was to assess the impact of switching from immediate-release (IR) methylphenidate (MPH) to OROS MPH (CONCERTA, a once-daily long-acting MPH formulation, in children and adolescents with attention-deficit/hyperactivity disorder (ADHD). Subjects with ADHD aged 6-16 (n=105),who were stably maintained on their current IR MPH regimen (10-60 mg/day), were switched to 18, 36 or 54 mg OROS MPH once daily for 21 days, depending on pre-study daily MPH dose. ADHD symptoms were assessed by parents, teachers and investigators. By Day 21, parent/caregiver IOWA Conners ratings had decreased from baseline by 2.7 points to 5.2 (I/O), and by 1.8 points to 5.0 (O/D). Teacher IOWA Conners ratings were maintained. Decreases in IOWA Conners ratings are indicative of ADHD symptom improvement. Approximately 75% of parents and investigators rated therapy as good or excellent. OROS MPH therapy was well tolerated. Switching from IR MPH to OROS MPH maintained and may have improved symptom control in children and adolescents with ADHD, during the course of this study. The changes in parent/caregiver IOWA Conners ratings suggest that OROS MPH improves symptom control in the after-school period. This is consistent with the 12-h duration of action previously demonstrated for OROS MPH.

  1. Calculation of wind speeds required to damage or destroy buildings

    NASA Astrophysics Data System (ADS)

    Liu, Henry

    Determination of wind speeds required to damage or destroy a building is important not only for the improvement of building design and construction but also for the estimation of wind speeds in tornadoes and other damaging storms. For instance, since 1973 the U.S. National Weather Service has been using the well-known Fujita scale (F scale) to estimate the maximum wind speeds of tornadoes [Fujita, 1981]. The F scale classifies tornadoes into 13 numbers, F-0 through F-12. The wind speed (maximum gust speed) associated with each F number is given in Table 1. Note that F-6 through F-12 are for wind speeds between 319 mi/hr (mph) and the sonic velocity (approximately 760 mph; 1 mph = 1.6 km/kr). However, since no tornadoes have been classified to exceed F-5, the F-6 through F-12 categories have no practical meaning [Fujita, 1981].

  2. A low upper limit on the subsurface rise speed of solar active regions.

    PubMed

    Birch, Aaron C; Schunker, Hannah; Braun, Douglas C; Cameron, Robert; Gizon, Laurent; Löptien, Björn; Rempel, Matthias

    2016-07-01

    Magnetic field emerges at the surface of the Sun as sunspots and active regions. This process generates a poloidal magnetic field from a rising toroidal flux tube; it is a crucial but poorly understood aspect of the solar dynamo. The emergence of magnetic field is also important because it is a key driver of solar activity. We show that measurements of horizontal flows at the solar surface around emerging active regions, in combination with numerical simulations of solar magnetoconvection, can constrain the subsurface rise speed of emerging magnetic flux. The observed flows imply that the rise speed of the magnetic field is no larger than 150 m/s at a depth of 20 Mm, that is, well below the prediction of the (standard) thin flux tube model but in the range expected for convective velocities at this depth. We conclude that convective flows control the dynamics of rising flux tubes in the upper layers of the Sun and cannot be neglected in models of flux emergence.

  3. A low upper limit on the subsurface rise speed of solar active regions

    PubMed Central

    Birch, Aaron C.; Schunker, Hannah; Braun, Douglas C.; Cameron, Robert; Gizon, Laurent; Löptien, Björn; Rempel, Matthias

    2016-01-01

    Magnetic field emerges at the surface of the Sun as sunspots and active regions. This process generates a poloidal magnetic field from a rising toroidal flux tube; it is a crucial but poorly understood aspect of the solar dynamo. The emergence of magnetic field is also important because it is a key driver of solar activity. We show that measurements of horizontal flows at the solar surface around emerging active regions, in combination with numerical simulations of solar magnetoconvection, can constrain the subsurface rise speed of emerging magnetic flux. The observed flows imply that the rise speed of the magnetic field is no larger than 150 m/s at a depth of 20 Mm, that is, well below the prediction of the (standard) thin flux tube model but in the range expected for convective velocities at this depth. We conclude that convective flows control the dynamics of rising flux tubes in the upper layers of the Sun and cannot be neglected in models of flux emergence. PMID:27453947

  4. MPH-M, AODV-M and DSR-M Performance Evaluation under Jamming Attacks.

    PubMed

    Del-Valle-Soto, Carolina; Mex-Perera, Carlos; Monroy, Raul; Nolazco-Flores, Juan A

    2017-07-05

    In this work, we present the design of a mitigation scheme for jamming attacks integrated to the routing protocols MPH, AODV, and DSR. The resulting protocols are named MPH-M (Multi-Parent Hierarchical - Modified), AODV-M (Ad hoc On Demand Distance Vector - Modified), and DSR-M (Dynamic Source Routing - Modified). For the mitigation algorithm, if the detection algorithm running locally in each node produces a positive result then the node is isolated; second, the routing protocol adapts their paths avoiding the isolated nodes. We evaluated how jamming attacks affect different metrics for all these modified protocols. The metrics we employ to detect jamming attack are number of packet retransmissions, number of CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) retries while waiting for an idle channel and the energy wasted by the node. The metrics to evaluate the performance of the modified routing protocols are the throughput and resilience of the system and the energy used by the nodes. We evaluated all the modified protocols when the attacker position was set near, middle and far of the collector node. The results of our evaluation show that performance for MPH-M is much better than AODV-M and DSR-M. For example, the node energy for MPH-M is 138.13% better than AODV-M and 126.07% better than DSR-M. Moreover, we also find that MPH-M benefits much more of the mitigation scheme than AODV-M and DSR-M. For example, the node energy consumption is 34.61% lower for MPH-M and only 3.92% and 3.42% for AODV-M and DSR-M, respectively. On throughput, the MPH protocol presents a packet reception efficiency at the collector node of 16.4% on to AODV and DSR when there is no mitigation mechanism. Moreover, MPH-M has an efficiency greater than 7.7% with respect to AODV-M and DSR-M when there is a mitigation scheme. In addition, we have that with the mitigation mechanism AODV-M and DSR-M do not present noticeable modification. However, MPH-M improves its efficiency

  5. MPH-M, AODV-M and DSR-M Performance Evaluation under Jamming Attacks

    PubMed Central

    Del-Valle-Soto, Carolina

    2017-01-01

    In this work, we present the design of a mitigation scheme for jamming attacks integrated to the routing protocols MPH, AODV, and DSR. The resulting protocols are named MPH-M (Multi-Parent Hierarchical - Modified), AODV-M (Ad hoc On Demand Distance Vector - Modified), and DSR-M (Dynamic Source Routing - Modified). For the mitigation algorithm, if the detection algorithm running locally in each node produces a positive result then the node is isolated; second, the routing protocol adapts their paths avoiding the isolated nodes. We evaluated how jamming attacks affect different metrics for all these modified protocols. The metrics we employ to detect jamming attack are number of packet retransmissions, number of CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) retries while waiting for an idle channel and the energy wasted by the node. The metrics to evaluate the performance of the modified routing protocols are the throughput and resilience of the system and the energy used by the nodes. We evaluated all the modified protocols when the attacker position was set near, middle and far of the collector node. The results of our evaluation show that performance for MPH-M is much better than AODV-M and DSR-M. For example, the node energy for MPH-M is 138.13% better than AODV-M and 126.07% better than DSR-M. Moreover, we also find that MPH-M benefits much more of the mitigation scheme than AODV-M and DSR-M. For example, the node energy consumption is 34.61% lower for MPH-M and only 3.92% and 3.42% for AODV-M and DSR-M, respectively. On throughput, the MPH protocol presents a packet reception efficiency at the collector node of 16.4% on to AODV and DSR when there is no mitigation mechanism. Moreover, MPH-M has an efficiency greater than 7.7% with respect to AODV-M and DSR-M when there is a mitigation scheme. In addition, we have that with the mitigation mechanism AODV-M and DSR-M do not present noticeable modification. However, MPH-M improves its efficiency

  6. Effect of temperature on leg kinematics in sprinting tarantulas (Aphonopelma hentzi): high speed may limit hydraulic joint actuation

    PubMed Central

    Booster, N. A.; Su, F. Y.; Adolph, S. C.; Ahn, A. N.

    2015-01-01

    ABSTRACT Tarantulas extend the femur–patella (proximal) and tibia–metatarsal (distal) joints of their legs hydraulically. Because these two hydraulically actuated joints are positioned in series, hemolymph flow within each leg is expected to mechanically couple the movement of the joints. In the current study, we tested two hypotheses: (1) at lower temperatures, movement of the two in-series hydraulic joints within a leg will be less coupled because of increased hemolymph viscosity slowing hemolymph flow; and (2) at higher temperatures, movement of the two in-series hydraulic joints will be less coupled because the higher stride frequencies limit the time available for hemolymph flow. We elicited maximal running speeds at four ecologically relevant temperatures (15, 24, 31 and 40°C) in Texas Brown tarantulas (Aphonopelma hentzi). The spiders increased sprint speed 2.5-fold over the temperature range by changing their stride frequency but not stride length. The coefficient of determination for linear regression (R2) of the proximal and distal joint angles was used as the measure of the degree of coupling between the two joints. This coupling coefficient between the proximal and distal joint angles, for both forelegs and hind­legs, was significantly lowest at the highest temperature at which the animals ran the fastest with the highest stride frequencies. The coordination of multiple, in-series hydraulically actuated joints may be limited by operating speed. PMID:25833132

  7. Perceptual and Cognitive Factors Imposing "Speed Limits" on Reading Rate: A Study with the Rapid Serial Visual Presentation.

    PubMed

    Primativo, Silvia; Spinelli, Donatella; Zoccolotti, Pierluigi; De Luca, Maria; Martelli, Marialuisa

    2016-01-01

    Adults read at high speed, but estimates of their reading rate vary greatly, i.e., from 100 to 1500 words per minute (wpm). This discrepancy is likely due to different recording methods and to the different perceptual and cognitive processes involved in specific test conditions. The present study investigated the origins of these notable differences in RSVP reading rate (RR). In six experiments we investigated the role of many different perceptual and cognitive variables. The presence of a mask caused a steep decline in reading rate, with an estimated masking cost of about 200 wpm. When the decoding process was isolated, RR approached values of 1200 wpm. When the number of stimuli exceeded the short-term memory span, RR decreased to 800 wpm. The semantic context contributed to reading speed only by a factor of 1.4. Finally, eye movements imposed an upper limit on RR (around 300 wpm). Overall, data indicate a speed limit of 300 wpm, which corresponds to the time needed for eye movement execution, i.e., the most time consuming mechanism. Results reconcile differences in reading rates reported by different laboratories and thus provide suggestions for targeting different components of reading rate.

  8. Theoretical Study of Operational Limits of High-Speed Quantum Dot Lasers

    DTIC Science & Technology

    2012-09-09

    Tech Libraries. Downloaded on December 4, 2009 at 14:35 from IEEE Xplore . Restrictions apply. 5776 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 27, NO. 24...licensed use limited to: to IEEExplore provided by Virginia Tech Libraries. Downloaded on December 4, 2009 at 14:35 from IEEE Xplore . Restrictions...licensed use limited to: to IEEExplore provided by Virginia Tech Libraries. Downloaded on December 4, 2009 at 14:35 from IEEE Xplore . Restrictions apply

  9. High-speed laser modulation beyond the relaxation resonance frequency limit.

    PubMed

    Sacher, Wesley D; Zhang, Eric J; Kruger, Brett A; Poon, Joyce K S

    2010-03-29

    We propose and show that for coupling modulated lasers (CMLs), in which the output coupler is modulated rather than the pump rate, the conventional relaxation resonance frequency limit to the laser modulation bandwidth can be circumvented. The modulation response is limited only by the coupler. Although CMLs are best suited to microcavities, as a proof-of-principle, a coupling-modulated erbium-doped fiber laser is modulated at 1 Gb/s, over 10000 times its relaxation resonance frequency.

  10. One spatial filter limits speed of detecting low and middle frequency gratings.

    PubMed

    Thomas, J P; Fagerholm, P; Bonnet, C

    1999-05-01

    Reaction times for detecting sinusoidal gratings depend jointly on grating contrast and spatial frequency. We examine whether the effect of spatial frequency results from low-pass filtering in a single channel or reflects processing of different frequencies by two or more different processing streams. Observers performed a speeded two-alternative spatial forced-choice detection. Errors and reaction times were measured. Contrasts varied from 0.05 to 0.67, and spatial frequencies from 0.72 to 6.51 cpd. No effect of uncertainty about spatial frequency was found, arguing against multiple channels. The data are well fit by a single channel model driven by a low pass filter.

  11. 49 CFR 174.86 - Maximum allowable operating speed.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Maximum allowable operating speed. 174.86 Section... operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15 mph...

  12. 49 CFR 174.86 - Maximum allowable operating speed.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Maximum allowable operating speed. 174.86 Section... operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15 mph...

  13. 49 CFR 174.86 - Maximum allowable operating speed.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Maximum allowable operating speed. 174.86 Section... operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15 mph...

  14. 49 CFR 174.86 - Maximum allowable operating speed.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Maximum allowable operating speed. 174.86 Section... operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15 mph...

  15. The influence of systematic pulse-limited physical exercise on the parameters of the cardiovascular system in patients over 65 years of age

    PubMed Central

    Chomiuk, Tomasz; Mamcarz, Artur

    2013-01-01

    Introduction The influence of physical exercise on the parameters of the cardiovascular system of elderly persons has not been sufficiently investigated yet. The aim of the study was to assess the influence of regular 6-week physical exercise using the Nordic walking (NW) method in a group of elderly persons on their physical performance and regulation of selected parameters assessing the cardiovascular system. Material and methods Fifty patients over 65 years of age participated in the study. The study encompassed: medical interview, physical examination, resting ECG, spiroergometry examination, 6MWT (6-minute walk test) and 24-hour ambulatory blood pressure monitoring (ABPM). During the exercise programme, the pulse was monitored using pulsometers. After the completion of the training, check-up tests assessing the same parameters were performed. The control group consisted of 18 persons over 65 years of age with similar cardiovascular problems. Results In the test group, duration of the physical effort increased by 1.02 min (p = 0.0001), the maximum load increased by 10.68 W (p = 0.0001), values of VO2max by 2.10 (p = 0.0218), distance improved in 6MWT by 75.04 m (p = 0.00001), systolic blood pressure decreased by 5.50 mm Hg (p = 0.035) and diastolic blood pressure by 3.50 mm Hg (p = 0.054) as compared to the control group. Conclusions Systematic NW physical exercise limited by the pulse had a beneficial effect on the physical performance of elderly persons as assessed with main parameters. A short 6-week programme of endurance exercises had a hypotensive effect in elderly persons over 65 years of age. PMID:23671429

  16. Wind speed reductions by large-scale wind turbine deployments lower turbine efficiencies and set low generation limits

    PubMed Central

    Miller, Lee M.; Kleidon, Axel

    2016-01-01

    Wind turbines generate electricity by removing kinetic energy from the atmosphere. Large numbers of wind turbines are likely to reduce wind speeds, which lowers estimates of electricity generation from what would be presumed from unaffected conditions. Here, we test how well wind power limits that account for this effect can be estimated without explicitly simulating atmospheric dynamics. We first use simulations with an atmospheric general circulation model (GCM) that explicitly simulates the effects of wind turbines to derive wind power limits (GCM estimate), and compare them to a simple approach derived from the climatological conditions without turbines [vertical kinetic energy (VKE) estimate]. On land, we find strong agreement between the VKE and GCM estimates with respect to electricity generation rates (0.32 and 0.37 We m−2) and wind speed reductions by 42 and 44%. Over ocean, the GCM estimate is about twice the VKE estimate (0.59 and 0.29 We m−2) and yet with comparable wind speed reductions (50 and 42%). We then show that this bias can be corrected by modifying the downward momentum flux to the surface. Thus, large-scale limits to wind power use can be derived from climatological conditions without explicitly simulating atmospheric dynamics. Consistent with the GCM simulations, the approach estimates that only comparatively few land areas are suitable to generate more than 1 We m−2 of electricity and that larger deployment scales are likely to reduce the expected electricity generation rate of each turbine. We conclude that these atmospheric effects are relevant for planning the future expansion of wind power. PMID:27849587

  17. Wind speed reductions by large-scale wind turbine deployments lower turbine efficiencies and set low generation limits.

    PubMed

    Miller, Lee M; Kleidon, Axel

    2016-11-29

    Wind turbines generate electricity by removing kinetic energy from the atmosphere. Large numbers of wind turbines are likely to reduce wind speeds, which lowers estimates of electricity generation from what would be presumed from unaffected conditions. Here, we test how well wind power limits that account for this effect can be estimated without explicitly simulating atmospheric dynamics. We first use simulations with an atmospheric general circulation model (GCM) that explicitly simulates the effects of wind turbines to derive wind power limits (GCM estimate), and compare them to a simple approach derived from the climatological conditions without turbines [vertical kinetic energy (VKE) estimate]. On land, we find strong agreement between the VKE and GCM estimates with respect to electricity generation rates (0.32 and 0.37 We m(-2)) and wind speed reductions by 42 and 44%. Over ocean, the GCM estimate is about twice the VKE estimate (0.59 and 0.29 We m(-2)) and yet with comparable wind speed reductions (50 and 42%). We then show that this bias can be corrected by modifying the downward momentum flux to the surface. Thus, large-scale limits to wind power use can be derived from climatological conditions without explicitly simulating atmospheric dynamics. Consistent with the GCM simulations, the approach estimates that only comparatively few land areas are suitable to generate more than 1 We m(-2) of electricity and that larger deployment scales are likely to reduce the expected electricity generation rate of each turbine. We conclude that these atmospheric effects are relevant for planning the future expansion of wind power.

  18. Design wind speeds for high hazard, moderate hazard, important/low hazard and general use facilities at the Savannah River Site

    SciTech Connect

    King, H.H.

    1989-09-11

    The design wind speeds for High Hazard, Moderate Hazard, Important/Low Hazard and General Use facilities at the Savannah River Site are developed below using the procedures and site-specific hazards model required by DOE Order 6430.1A. These are less than the previously required Design Wind Speeds and are: (1) High Hazard (Maximum Resistance) Facility, 185 mph; (2) Moderate Hazard (High Resistance) Facility, 37 mph; (3) Important/Low Hazard (Intermediate) Facility, 83 mph; and, (4) General Use (Standard) Facility, 78 mph.

  19. Design wind speeds for high hazard, moderate hazard, important/low hazard and general use facilities at the Savannah River Site

    SciTech Connect

    King, H.H.

    1989-09-11

    The design wind speeds for High Hazard, Moderate Hazard, Important/Low Hazard and General Use facilities at the Savannah River Site are developed below using the procedures and site-specific hazards model required by DOE Order 6430.1A. These are less than the previously required Design Wind Speeds and are: (1) High Hazard (Maximum Resistance) Facility, 185 mph; (2) Moderate Hazard (High Resistance) Facility, 37 mph; (3) Important/Low Hazard (Intermediate) Facility, 83 mph; and, (4) General Use (Standard) Facility, 78 mph.

  20. Exploring the speed-resolution limits of supercritical fluid chromatography at ultra-high pressures.

    PubMed

    Pauw, Ruben De; Shoykhet Choikhet, Konstantin; Desmet, Gert; Broeckhoven, Ken

    2014-12-29

    The limits of supercritical fluid chromatography have been experimentally explored using inlet pressures at the limits of the current commercial instrumentation (400-600 bar), as well as pressures significantly surpassing this (up to 1050 bar). It was found that efficiencies in the range of 200,000 theoretical plates can be achieved for a void time t0 of roughly 6min using superficially porous particles (2.7 and 4.6μm) while remaining within the pressure limits of current commercial instrumentation and columns. If lower efficiencies are sufficient (<100, 000 plates), smaller particles (e.g. 1.8μm) provide the best trade-off between analysis time and efficiency. Apparent efficiencies of 83,000 (k'=2.2) to 76,000 (k'=6.6) plates could be achieved for void times around 1min by pushing the pressure limits up to 1050 bar on a column length of 500mm. As the optimal mobile phase velocity for these small particle columns is even higher, it is required to use narrow-bore columns (2.1mm ID) to remain within the instrument limits of flow rate. The smaller column volume however puts a strain on the separation efficiency due to extra-column band broadening, resulting in losses up to 50% for weakly retained compounds for column lengths below 250mm. It is also illustrated that when using sub-2μm particles, especially for separations where a significant amount of organic modifier is required, the current pressure limits of state-of-the-art instrumentation can sometimes be insufficient. For a gradient running from 4 to 40 v% methanol on a 300mm column at the optimal flow rate the pressure increases from 420 to 810 bar. Operating SFC-columns with a large pressure gradient induces several (undesired) side effects which have been investigated as well. It has been found that, since the viscosity increases strongly with pressure in SFC, the optimal flow rate and the minimal plate height can significantly change when the column length is changed. Whereas e.g. a 3×150mm column (2.7

  1. Influence of road markings, lane widths and driver behaviour on proximity and speed of vehicles overtaking cyclists.

    PubMed

    Shackel, Stella C; Parkin, John

    2014-12-01

    The proximity and speed of motor traffic passing cyclists in non-separated conditions may be so close and so great as to cause discomfort. A variety of road design and driver behaviour factors may affect overtaking speeds and distances. The investigation presented in this paper builds on previous research and fills gaps in that research by considering the presence of cycle lanes on 20 mph and 30 mph roads, different lane widths, different lane markings, vehicle type, vehicle platooning and oncoming traffic. Data were collected from a bicycle ridden a distance of one metre from the kerb fitted with an ultrasonic distance detector and forward and sideways facing cameras. Reduced overtaking speeds correlate with narrower lanes, lower speed limits, and the absence of centre-line markings. Drivers passed slower if driving a long vehicle, driving in a platoon, and when approaching vehicles in the opposing carriageway were within five seconds of the passing point. Increased passing distances were found where there were wider or dual lane roads, and in situations where oncoming vehicles were further away and not in a platoon. In mixed traffic conditions, cyclists will be better accommodated by wider cross-sections, lower speed limits and the removal of the centre-line marking.

  2. Human search with a limited field of view: effects of scan speed, aperture size, and target conspicuity

    NASA Astrophysics Data System (ADS)

    Hogervorst, Maarten A.; Toet, Alexander; Bijl, Piet

    2013-04-01

    We investigate how human visual search performance with field of view (FOV) restrictions depends on scan speed, zoom factor, target location, and conspicuity. First, observers search a FOV that moves at a constant speed along a predefined path over a visual search scene (the field of regard, or FOR), and we measure the effects of scan speed, zoom factor, FOV size, target location, and conspicuity on search performance (detection time and probability). Then observers search either visual or thermal scenes by freely moving a joystick-controlled FOV over the FOR, while freely selecting the zoom factor in some conditions, and we measure the effects of the scan path characteristics and the use of different strategies on search performance. Search performance depends on the effective FOV size (the area where targets are expected to occur), but is largely independent of the display area. Both for visual and thermal imagery, various search performance measures correlate with target conspicuity. The results of both experiments suggest that observers can optimize their performance by adjusting their scanning behavior both to their visual limitations and to the expected target conspicuity. We present the outlines of a simple search model based on these current findings.

  3. High speed InAs electron avalanche photodiodes overcome the conventional gain-bandwidth product limit.

    PubMed

    Marshall, Andrew R J; Ker, Pin Jern; Krysa, Andrey; David, John P R; Tan, Chee Hing

    2011-11-07

    High bandwidth, uncooled, Indium Arsenide (InAs) electron avalanche photodiodes (e-APDs) with unique and highly desirable characteristics are reported. The e-APDs exhibit a 3dB bandwidth of 3.5 GHz which, unlike that of conventional APDs, is shown not to reduce with increasing avalanche gain. Hence these InAs e-APDs demonstrate a characteristic of theoretically ideal electron only APDs, the absence of a gain-bandwidth product limit. This is important because gain-bandwidth products restrict the maximum exploitable gain in all conventional high bandwidth APDs. Non-limiting gain-bandwidth products up to 580 GHz have been measured on these first high bandwidth e-APDs.

  4. Limit of the speed-resolution properties in adiabatic supercritical fluid chromatography.

    PubMed

    Gritti, Fabrice; Guiochon, Georges

    2013-06-21

    controls the column efficiency at high speeds. Eventually, for the same stationary phase and speed of analysis, SFC methods using pure CO2 may provide at least a twice column efficiency than LC methods using pure acetonitrile. For a constant pressure drop and resolution power, SFC methods may generate four times faster analyses than LC methods. Ultimately, a standard commercial 4.6mm × 50mm long column packed with 2.6 μm core-shell particles, operated with an inlet flow rate of 25 mL/min in fast SFC (200 bar back pressure, 40 °C) may provide a hold-up time of about 1s requiring data acquisition at a frequency of 400 Hz, with a variance of 0.35 μL(2). This performance will require the use of new, ultra-low dispersion SFC system.

  5. Virtual practicums within an MPH program: a career development case study.

    PubMed

    Goodman, Jeffrey

    2015-01-01

    This article focuses on an innovative "virtual" practicum arrangement and provides insight for public health professionals seeking a meaningful practicum experience. The traditional practicum model where a student physically reports to work at the field site with a near full-time commitment has become increasingly challenging and often limiting in terms of field site choices and experiences available to a student depending on the location of a school and the student's area of interest. This is particularly true with students who are enrolled in a distance learning program. The experience obtained from a practicum is more important than ever before as rapid changes occur in health service delivery models as a result of the Patient Protection and Affordable Care Act. Career development through a practicum can be vitally important to a mid-career student seeking to remain relevant and in demand within a changing job market. To fulfill these needs, while still obtaining the benefits of a practicum, a virtual practicum arrangement could provide a solution. This case study provides practical tips based on the successful experience of a recent MPH graduate. © 2014 Society for Public Health Education.

  6. KENNEDY SPACE CENTER, FLA. - Framed between palm trees, solid rocket boosters loom above the Mobile Launcher Platform (MLP) as the crawler transporter slowly moves it along the crawlerway. The journey is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - Framed between palm trees, solid rocket boosters loom above the Mobile Launcher Platform (MLP) as the crawler transporter slowly moves it along the crawlerway. The journey is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  7. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  8. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The view reveals the river gravel surface that is 4 inches thick on the straightaway sections and 8 inches thick on curves. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The view reveals the river gravel surface that is 4 inches thick on the straightaway sections and 8 inches thick on curves. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  9. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  10. KENNEDY SPACE CENTER, FLA. - Carrying a set of twin solid rocket boosters, the crawler transporter slowly moves the Mobile Launcher Platform (MLP) past the NASA-KSC News Center where the U.S. flag flies daily. The journey is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - Carrying a set of twin solid rocket boosters, the crawler transporter slowly moves the Mobile Launcher Platform (MLP) past the NASA-KSC News Center where the U.S. flag flies daily. The journey is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  11. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (on the horizon at right; Pad 39B is at far left), and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (on the horizon at right; Pad 39B is at far left), and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  12. KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician walks towards the intersection of the crawlerway beside a crawler-transporter moving Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A, and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician walks towards the intersection of the crawlerway beside a crawler-transporter moving Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A, and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  13. KENNEDY SPACE CENTER, FLA. - As the crawler transporter slowly moves the Mobile Launcher Platform (MLP) out of the Vehicle Assembly Building, the two solid rocket boosters on top are framed in the doorway. The move is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - As the crawler transporter slowly moves the Mobile Launcher Platform (MLP) out of the Vehicle Assembly Building, the two solid rocket boosters on top are framed in the doorway. The move is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  14. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (framed between the boosters), and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (framed between the boosters), and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  15. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, along the crawlerway in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, along the crawlerway in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  16. KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician inspects the shoes on one of eight tracks of a crawler-transporter (CT). The CT is moving Mobile Launcher Platform (MLP) number 3 with a set of twin solid rocket boosters bolted on top to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician inspects the shoes on one of eight tracks of a crawler-transporter (CT). The CT is moving Mobile Launcher Platform (MLP) number 3 with a set of twin solid rocket boosters bolted on top to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  17. KENNEDY SPACE CENTER, FLA. - The crawler transporter has slowly moved the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter has slowly moved the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  18. KENNEDY SPACE CENTER, FLA. - Seen across the water of the Launch Complex 39 turn basin, a crawler-transporter, carrying Mobile Launcher Platform (MLP) number 3 with a set of twin solid rocket boosters bolted atop, crawls out of the 525-foot-tall Vehicle Assembly Building during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Seen across the water of the Launch Complex 39 turn basin, a crawler-transporter, carrying Mobile Launcher Platform (MLP) number 3 with a set of twin solid rocket boosters bolted atop, crawls out of the 525-foot-tall Vehicle Assembly Building during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  19. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, crawl out of the Vehicle Assembly Building (VAB) in support of the second engineering analysis vibration test on the crawler and MLP. In the background is another MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, crawl out of the Vehicle Assembly Building (VAB) in support of the second engineering analysis vibration test on the crawler and MLP. In the background is another MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  20. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (on the horizon) and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (on the horizon) and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  1. KENNEDY SPACE CENTER, FLA. - A high-flying bird takes a closer look at the Mobile Launcher Platform (MLP) number 3 with twin solid rocket boosters bolted to it as it crawls toward Launch Pad 39A, in the background. The crawler is moving along the crawlerway at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - A high-flying bird takes a closer look at the Mobile Launcher Platform (MLP) number 3 with twin solid rocket boosters bolted to it as it crawls toward Launch Pad 39A, in the background. The crawler is moving along the crawlerway at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  2. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, crawls away from the Vehicle Assembly Building in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, crawls away from the Vehicle Assembly Building in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  3. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. In the distance, at left, is Launch Pad 39A. The water on the right of the crawlerway is the Banana River. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. In the distance, at left, is Launch Pad 39A. The water on the right of the crawlerway is the Banana River. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  4. KENNEDY SPACE CENTER, FLA. - As the crawler transporter slowly moves the Mobile Launcher Platform (MLP) out of the Vehicle Assembly Building, the driver of the front control cab can be seen. The MLP is carrying two solid rocket boosters for engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - As the crawler transporter slowly moves the Mobile Launcher Platform (MLP) out of the Vehicle Assembly Building, the driver of the front control cab can be seen. The MLP is carrying two solid rocket boosters for engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  5. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, along the crawlerway in support of engineering analysis vibration tests on the crawler and MLP. In the distance, at left, is Launch Pad 39A. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, along the crawlerway in support of engineering analysis vibration tests on the crawler and MLP. In the distance, at left, is Launch Pad 39A. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  6. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. On either side of the boosters on the horizon can be seen the two launch pads. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. On either side of the boosters on the horizon can be seen the two launch pads. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  7. KENNEDY SPACE CENTER, FLA. - Viewed across the turn basin in the Launch Complex 39 Area, the crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB). The journey is in support of engineering analysis vibration tests on the crawler and MLP. The water on the right of the crawlerway is the Banana River. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - Viewed across the turn basin in the Launch Complex 39 Area, the crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB). The journey is in support of engineering analysis vibration tests on the crawler and MLP. The water on the right of the crawlerway is the Banana River. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  8. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters bolted to it, atop the crawler-transporter, crawl to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. In the background are Launch Pads 39A (right) and 39B (left). The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters bolted to it, atop the crawler-transporter, crawl to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. In the background are Launch Pads 39A (right) and 39B (left). The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  9. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters bolted to it, atop the crawler-transporter, inches along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The MLP is viewed from the KSC News Center across the turn basin. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters bolted to it, atop the crawler-transporter, inches along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The MLP is viewed from the KSC News Center across the turn basin. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  10. KENNEDY SPACE CENTER, FLA. - The crawler transporter is slowly moving the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter is slowly moving the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  11. KENNEDY SPACE CENTER, FLA. - The crawler-transporter carrying Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, crawls to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. From this perspective, the Launch Control Center (left) and the 525-foot-tall Vehicle Assembly Building (right) in the background appear dwarfed by the 184-foot-tall boosters. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - The crawler-transporter carrying Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, crawls to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. From this perspective, the Launch Control Center (left) and the 525-foot-tall Vehicle Assembly Building (right) in the background appear dwarfed by the 184-foot-tall boosters. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  12. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch away from the Vehicle Assembly Building (VAB) in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch away from the Vehicle Assembly Building (VAB) in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  13. KENNEDY SPACE CENTER, FLA. - A crawler-transporter carrying Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, crawls to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. From this perspective, the Launch Control Center (left) and the 525-foot-tall Vehicle Assembly Building (right) in the background appear dwarfed by the 184-foot-tall boosters. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - A crawler-transporter carrying Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, crawls to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. From this perspective, the Launch Control Center (left) and the 525-foot-tall Vehicle Assembly Building (right) in the background appear dwarfed by the 184-foot-tall boosters. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  14. KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician monitors the performance of a crawler-transporter as it moves Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, to the intersection in the crawlerway during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A, and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician monitors the performance of a crawler-transporter as it moves Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, to the intersection in the crawlerway during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A, and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  15. Speed Control of a Sonar-Based Mobile Robot by Considering the Limitation of Accelerated Velocity

    NASA Astrophysics Data System (ADS)

    Emaru, Takanori; Hoshino, Yohei; Kobayashi, Yukinori

    In an autonomous mobile robot, ultrasonic time-of-flight (TOF) ranging systems are widely used for distance measurements. However, ultrasonic TOF ranging systems tend to neglect infinitesimal reflected waves below a threshold level. Therefore, we have proposed an integration-type ultrasonic wave sensor that utilizes the integration value of the sonar's reflected wave to recognize a traversable area for an autonomous mobile robot. The proposed method simultaneously determines the path and velocity; however, the calculated velocity varies significantly because of sensor noise or error. This paper presents a novel approach to filter the velocity by considering the accelerated velocity. This enables us to consider the limitation of the force exerted by the robot. The validity of the proposed method is investigated in various environments by applying this method to an autonomous mobile robot.

  16. The credibility of speed limits on 80 km/h rural roads: The effects of road and person(ality) characteristics.

    PubMed

    Goldenbeld, Charles; van Schagen, Ingrid

    2007-11-01

    The present study aimed to operationalise the concept of credible speed limits and to make a first step to elaborate it in such a way that road authorities can put the concept into practice. The study focused on the credibility of an 80 km/h limit for different rural roads and assessed the effects of characteristics of the road and its environment as well as the effects of person and personality characteristics. Almost 600 Dutch car drivers were asked to judge 27 photographs of (different) rural roads with a posted speed limit of 80 km/h. To determine the degree of credibility, for each road scene the subjects filled in the preferred speed and the speed limit they considered to be safe. The results show large differences in both preferred speed and the safe speed limit between the road scenes, both below and above the limit of 80 km/h. These differences were related to a number of characteristics of the road and the road environment, such as the presence or absence of a curve and characteristics concerning the field of view (sight distance, clarity of situation). There were also large differences between subjects and these were related to age, the degree of sensation seeking, the number of speeding tickets in the last 3 years and the part of the country they lived in. Subjects were influenced by more or less the same road features.

  17. Posted and free-flow speeds for rural multilane highways in Georgia

    SciTech Connect

    Dixon, K.K.; Wu, C.H.; Sarasua, W.; Daniel, J.

    1999-12-01

    The National Highway System Designation Act of 1995 repealed the national maximum speed limit. As a result, approximately 70% of the US has increased posted speed limits to 104.7 km/h (65 mi/h) for select multilane highways. This study evaluates the application of the Highway Capacity Manual multilane highway rules-of-thumb for free-flow speed to both an 88.6 and a 104.7 km/h (55 and 65 mi/h) posted speed limit condition. The paper further quantifies the observed relationship between the posted speed limit and observed free-flow speed on rural multilane highways in Georgia. Specific issues evaluated include heavy vehicle influence, traffic volumes, access point density, and vertical grade. The research indicates that the current Highway Capacity Manual rule-of-thumb free-flow estimation technique based on posted speed limit does not adequately estimate free-flow speed for the higher speed limit condition.

  18. Structure and Function of the Macrolide Biosensor Protein, MphR(A), with and without Erythromycin

    SciTech Connect

    Zheng, Jianting; Sagar, Vatsala; Smolinsky, Adam; Bourke, Chase; LaRonde-LeBlanc, Nicole; Cropp, T. Ashton

    2009-09-02

    The regulatory protein MphR(A) has recently seen extensive use in synthetic biological applications, such as metabolite sensing and exogenous control of gene expression. This protein negatively regulates the expression of a macrolide 2{prime}-phosphotransferase I resistance gene (mphA) via binding to a 35-bp DNA operator upstream of the start codon and is de-repressed by the presence of erythromycin. Here, we present the refined crystal structure of the MphR(A) protein free of erythromycin and that of the MphR(A) protein with bound erythromycin at 2.00- and 1.76-{angstrom} resolutions, respectively. We also studied the DNA binding properties of the protein and identified mutants of MphR(A) that are defective in gene repression and ligand binding in a cell-based reporter assay. The combination of these two structures illustrates the molecular basis of erythromycin-induced gene expression and provides a framework for additional applied uses of this protein in the isolation and engineered biosynthesis of polyketide natural products.

  19. MAGIC Upper Limits for Two Milagro-detected Bright Fermi Sources in the Region of SNR G65.1+0.6

    NASA Astrophysics Data System (ADS)

    Aleksić, J.; Antonelli, L. A.; Antoranz, P.; Backes, M.; Barrio, J. A.; Bastieri, D.; Becerra González, J.; Bednarek, W.; Berdyugin, A.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Boller, A.; Bonnoli, G.; Bordas, P.; Borla Tridon, D.; Bosch-Ramon, V.; Bose, D.; Braun, I.; Bretz, T.; Camara, M.; Carmona, E.; Carosi, A.; Colin, P.; Contreras, J. L.; Cortina, J.; Covino, S.; Dazzi, F.; De Angelis, A.; De Cea del Pozo, E.; De Lotto, B.; De Maria, M.; De Sabata, F.; Delgado Mendez, C.; Diago Ortega, A.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Elsaesser, D.; Errando, M.; Ferenc, D.; Fonseca, M. V.; Font, L.; García López, R. J.; Garczarczyk, M.; Gaug, M.; Giavitto, G.; Godinović, N.; Hadasch, D.; Herrero, A.; Hildebrand, D.; Höhne-Mönch, D.; Hose, J.; Hrupec, D.; Jogler, T.; Klepser, S.; Krähenbühl, T.; Kranich, D.; Krause, J.; La Barbera, A.; Leonardo, E.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; Lorenz, E.; Majumdar, P.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Miyamoto, H.; Moldón, J.; Moralejo, A.; Nieto, D.; Nilsson, K.; Orito, R.; Oya, I.; Paoletti, R.; Paredes, J. M.; Partini, S.; Pasanen, M.; Pauss, F.; Pegna, R. G.; Perez-Torres, M. A.; Persic, M.; Peruzzo, L.; Pochon, J.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Puchades, N.; Puljak, I.; Reichardt, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rissi, M.; Rügamer, S.; Saggion, A.; Saito, K.; Saito, T. Y.; Salvati, M.; Sánchez-Conde, M.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shayduk, M.; Sierpowska-Bartosik, A.; Sillanpää, A.; Sitarek, J.; Sobczynska, D.; Spanier, F.; Spiro, S.; Stamerra, A.; Steinke, B.; Storz, J.; Strah, N.; Struebig, J. C.; Suric, T.; Takalo, L.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Torres, D. F.; Vankov, H.; Wagner, R. M.; Weitzel, Q.; Zabalza, V.; Zandanel, F.; Zanin, R.

    2010-12-01

    We report on the observation of the region around supernova remnant G65.1+0.6 with the stand-alone MAGIC-I telescope. This region hosts the two bright GeV gamma-ray sources 1FGL J1954.3+2836 and 1FGL J1958.6+2845. They are identified as GeV pulsars and both have a possible counterpart detected at about 35 TeV by the Milagro observatory. MAGIC collected 25.5 hr of good quality data and found no significant emission in the range around 1 TeV. We therefore report differential flux upper limits, assuming the emission to be point-like (<=0fdg1) or within a radius of 0fdg3. In the point-like scenario, the flux limits around 1 TeV are at the level of 3% and 2% of the Crab Nebula flux for the two sources, respectively. This implies that the Milagro emission is either extended over a much larger area than our point-spread function or it must be peaked at energies beyond 1 TeV, resulting in a photon index harder than 2.2 in the TeV band.

  20. A methodology for evaluating and reducing rotor losses, heating, and operational limitations of high-speed flywheel batteries

    NASA Astrophysics Data System (ADS)

    Flynn, Mark Matthew

    Flywheel batteries are machines that store kinetic energy in the form of a rotating flywheel. Energy is transferred to and from the flywheel via a motor-generator mounted on the flywheel rotor. For mobile systems in particular, it is important to maximize the stored energy while minimizing the mass and volume of the flywheel battery. This requirement leads to the use of high rotational speeds which in turn necessitates the use of composite materials for flywheel construction, magnetic bearings for reduced wear and friction losses, and a low pressure environment to reduce windage losses. With the flywheel rotor suspended on magnetic bearings and operating in a partial vacuum, radiation becomes the primary heat transfer mode for removing losses incurred on the rotor. Radiative heat transfer from the rotor to the flywheel battery housing is limited by the relatively low maximum allowable temperature of the composite materials and the permanent magnets which are often used in the motor-generator. In order to ensure the feasibility of a high-speed flywheel battery design it then becomes paramount to properly manage the total rotor losses as well as the heat removal strategy. This dissertation develops a methodology for accurately modeling the components of rotor heating in high-speed flywheel batteries with a focus on mobile systems employing an integrated design whereby the motor-generator is integrated with the flywheel into a common vacuum housing. The methodology makes it possible to reduce losses through design, construction, and operation so that high-speed flywheel batteries made with temperature sensitive components such as permanent magnets and composite materials can be operated without serious overheating. The rotor loss origins are investigated with respect to windage, magnetic bearing, and motor-generator sources in general, and with specific regard to a metropolitan transit bus flywheel battery system developed by the University of Texas Center for

  1. Minimum speed limit for ocean ridge magmatism from 210Pb-226Ra-230Th disequilibria.

    PubMed

    Rubin, K H; van der Zander, I; Smith, M C; Bergmanis, E C

    2005-09-22

    Although 70 per cent of global crustal magmatism occurs at mid-ocean ridges-where the heat budget controls crustal structure, hydrothermal activity and a vibrant biosphere-the tempo of magmatic inputs in these regions remains poorly understood. Such timescales can be assessed, however, with natural radioactive-decay-chain nuclides, because chemical disruption to secular equilibrium systems initiates parent-daughter disequilibria, which re-equilibrate by the shorter half-life in a pair. Here we use 210Pb-226Ra-230Th radioactive disequilibria and other geochemical attributes in oceanic basalts less than 20 years old to infer that melts of the Earth's mantle can be transported, accumulated and erupted in a few decades. This implies that magmatic conditions can fluctuate rapidly at ridge volcanoes. 210Pb deficits of up to 15 per cent relative to 226Ra occur in normal mid-ocean ridge basalts, with the largest deficits in the most magnesium-rich lavas. The 22-year half-life of 210Pb requires very recent fractionation of these two uranium-series nuclides. Relationships between 210Pb-deficits, (226Ra/230Th) activity ratios and compatible trace-element ratios preclude crustal-magma differentiation or daughter-isotope degassing as the main causes for the signal. A mantle-melting model can simulate observed disequilibria but preservation requires a subsequent mechanism to transport melt rapidly. The likelihood of magmatic disequilibria occurring before melt enters shallow crustal magma bodies also limits differentiation and heat replenishment timescales to decades at the localities studied.

  2. Effects of perinatal methylphenidate (MPH) treatment on postweaning behaviors of male and female Sprague-Dawley rats.

    PubMed

    Ferguson, Sherry A; Delbert Law, C; Sahin, Leyla; Montenegro, Susan V

    2015-01-01

    Methylphenidate (MPH) is a common treatment for adult Attention Deficit Hyperactivity Disorder (ADHD). However, little information exists regarding its safety during pregnancy and thus, women with ADHD face difficult decisions regarding continued use during pregnancy. Thus, Sprague-Dawley rats were orally treated 3×/day with 0 (control), 6 (low), 18 (mid), or 42 (high) mg MPH/kg/day (i.e., 0, 2, 6, or 14mg/kg at each treatment time) on gestational days 6-21. All offspring/litter were orally treated with the same dose their dam had received on postnatal days (PNDs) 1-21. After weaning, offspring were assessed for adolescent play behavior, locomotor activity, motor coordination, Barnes maze performance, acoustic startle response, novel object recognition, residential running wheel activity, flavored solution intake, home cage behavior, water maze performance, elevated plus maze behavior, locomotor response to an MPH challenge, and passive avoidance. At euthanasia, whole brain and striatal weights as well as serum hormone levels were measured. Body weights of the high MPH group were reduced in both sexes. Males of the high MPH group were less active than control males in open field assessments on PNDs 40-42. Latency to maximum acoustic startle was significantly altered in females of the medium and high MPH groups and residential running wheel activity of females of the low and medium MPH groups was lower than control females. Open arm entries in the elevated plus maze were increased in subjects of the medium MPH group. Females of the low MPH group were less sensitive to the locomotor-increasing effects of an acute 5mg/kg MPH challenge. Serum hormone levels and whole brain and striatal weights were not altered by prior MPH treatment. These results indicate that MPH treatment during development has sporadic effects on postweaning behaviors and those effects were generally exhibited by females.

  3. Impact of limited hamstring flexibility on vertical jump, kicking speed, sprint, and agility in young football players.

    PubMed

    García-Pinillos, F; Ruiz-Ariza, A; Moreno del Castillo, R; Latorre-Román, P Á

    2015-01-01

    This study aims to analyse the impact of limited hamstring flexibility (HF) on specific football skills, such as sprinting and jumping ability, agility, and kicking speed in young football players. Forty-three male football players (aged 14-18) from a semi-professional football academy participated voluntarily in this study. Data about anthropometric measurements, HF (unilateral passive straight-leg raise test: PSLR), vertical jumping ability (countermovement jump: CMJ), sprinting ability (5, 10, 20 m: S5 m, S10 m, S20 m), agility (Balsom agility test: BAT), and kicking speed in terms of ball speed (dominant and non-dominant leg: KSdom and KSnon-dom) were collected. Cluster analysis grouped according to HF, dividing participants into a flexible group (FG, n = 24) and a non-flexible group (NFG, n = 19) in relation to performances on the PSLR test. Despite finding no significant differences between groups in body composition and age, the FG performed better in terms of sprint scores (S5 m: 6.12%, S10 m: 4.09%, S20 m: 3.29%), BAT score (4.11%), CMJ score (10.49%), and scores for KSdom (6.86%) and KSnon-dom (8%) than the NFG. The results suggest that HF is a key factor for performing football-specific skills, such as sprinting, jumping, agility, and kicking in young football players. These results support the rationale that muscle flexibility must be specifically trained in football players beginning at early ages.

  4. Differential regulation of the anti-crossover and replication fork regression activities of Mph1 by Mte1

    PubMed Central

    Xue, Xiaoyu; Papusha, Alma; Choi, Koyi; Bonner, Jaclyn N.; Kumar, Sandeep; Niu, Hengyao; Kaur, Hardeep; Zheng, Xiao-Feng; Donnianni, Roberto A.; Lu, Lucy; Lichten, Michael; Zhao, Xiaolan; Ira, Grzegorz; Sung, Patrick

    2016-01-01

    We identified Mte1 (Mph1-associated telomere maintenance protein 1) as a multifunctional regulator of Saccharomyces cerevisiae Mph1, a member of the FANCM family of DNA motor proteins important for DNA replication fork repair and crossover suppression during homologous recombination. We show that Mte1 interacts with Mph1 and DNA species that resemble a DNA replication fork and the D loop formed during recombination. Biochemically, Mte1 stimulates Mph1-mediated DNA replication fork regression and branch migration in a model substrate. Consistent with this activity, genetic analysis reveals that Mte1 functions with Mph1 and the associated MHF complex in replication fork repair. Surprisingly, Mte1 antagonizes the D-loop-dissociative activity of Mph1–MHF and exerts a procrossover role in mitotic recombination. We further show that the influence of Mte1 on Mph1 activities requires its binding to Mph1 and DNA. Thus, Mte1 differentially regulates Mph1 activities to achieve distinct outcomes in recombination and replication fork repair. PMID:26966246

  5. Effect of two-qutrit entanglement on quantum speed limit time of a bipartite V-type open system

    NASA Astrophysics Data System (ADS)

    Behzadi, N.; Ahansaz, B.; Ektesabi, A.; Faizi, E.

    2017-03-01

    In the present paper, quantum speed limit (QSL) time of a bipartite V-type three-level atomic system under the effect of two-qutrit entanglement is investigated. Each party interacts with own independent reservoir. By considering two local unitarily equivalent Werner states and the Horodecki PPT state, as initial states, the QSL time is evaluated for each of them in the respective entangled regions. It is counterintuitively observed that the effect of entanglement on the QSL time driven from each of the initial Werner states are completely different when the degree of non-Markovianity is considerable. In addition, it is interesting that the effect of entanglement of the non-equivalent Horodecki state on the calculated QSL time displays an intermediate behavior relative to the cases obtained for the Werner states.

  6. Design of an efficient real-time algorithm using reduced feature dimension for recognition of speed limit signs.

    PubMed

    Cho, Hanmin; Han, Seungwha; Hwang, Sun-Young

    2013-01-01

    We propose a real-time algorithm for recognition of speed limit signs from a moving vehicle. Linear Discriminant Analysis (LDA) required for classification is performed by using Discrete Cosine Transform (DCT) coefficients. To reduce feature dimension in LDA, DCT coefficients are selected by a devised discriminant function derived from information obtained by training. Binarization and thinning are performed on a Region of Interest (ROI) obtained by preprocessing a detected ROI prior to DCT for further reduction of computation time in DCT. This process is performed on a sequence of image frames to increase the hit rate of recognition. Experimental results show that arithmetic operations are reduced by about 60%, while hit rates reach about 100% compared to previous works.

  7. Maximal voluntary fingertip force production is not limited by movement speed in combined motion and force tasks.

    PubMed

    Keenan, Kevin G; Santos, Veronica J; Venkadesan, Madhusudhan; Valero-Cuevas, Francisco J

    2009-07-08

    Numerous studies of limbs and fingers propose that force-velocity properties of muscle limit maximal voluntary force production during anisometric tasks, i.e., when muscles are shortening or lengthening. Although this proposition appears logical, our study on the simultaneous production of fingertip motion and force disagrees with this commonly held notion. We asked eight consenting adults to use their dominant index fingertip to maximize voluntary downward force against a horizontal surface at specific postures (static trials), and also during an anisometric "scratching" task of rhythmically moving the fingertip along a 5.8 +/- 0.5 cm target line. The metronome-timed flexion-extension movement speed varied 36-fold from "slow" (1.0 +/- 0.5 cm/s) to "fast" (35.9 +/- 7.8 cm/s). As expected, maximal downward voluntary force diminished (44.8 +/- 15.6%; p = 0.001) when any motion (slow or fast) was added to the task. Surprisingly, however, a 36-fold increase in speed did not affect this reduction in force magnitude. These remarkable results for such an ordinary task challenge the dominant role often attributed to force-velocity properties of muscle and provide insight into neuromechanical interactions. We propose an explanation that the simultaneous enforcement of mechanical constraints for motion and force reduces the set of feasible motor commands sufficiently so that force-velocity properties cease to be the force-limiting factor. While additional work is necessary to reveal the governing mechanisms, the dramatic influence that the simultaneous enforcement of motion and force constraints has on force output begins to explain the vulnerability of dexterous function to development, aging, and even mild neuromuscular pathology.

  8. 77 FR 4623 - Wheego Electric Cars, Inc. Receipt of Petition for Temporary Exemption From the Electronic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-30

    ... wheels (spin out) or directional control at the front wheels (plow out). An anti-lock brake system (ABS... limited to a top speed of 65 mph, which may contribute to a reduction of crashes associated with high...

  9. What Motivates Talented Medical Students to Study Simultaneously at Master of Public Health (MPH)?

    PubMed

    Manavi, Sahar; Nedjat, Saharnaz; Pasalar, Parvin; Majdzadeh, Reza

    2013-01-01

    Nearly three decades ago, the Master of Public Health (MPH) academic degree was introduced to Tehran University of Medical Sciences' School of Public Health, Tehran, Iran. A new program for simultaneous education of medical, pharmaceutical and dental students was initiated in 2006. Talented students had the opportunity to study MPH simultaneously. There were some concerns about this kind of admission; as to whether these students who were not familiar with the health system had the appropriate attitude and background for this field of education. And with the present rate of brain drain, is this just a step towards their immigration without the fulfillment of public health? This qualitative study was conducted in 2012 where 26 students took part in focused group discussions and individual interviews. The students were questioned about their motivation and the program's impact on their future career. The participants' statements were analyzed using thematic analysis. THE PRIMARY MOTIVATIONS OF STUDENTS WHO ENTERED THIS PROGRAM WERE: learning health knowledge related issues, gaining a perspective beyond clinical practice, obtaining a degree to strengthen their academic résumé, immigration, learning academic research methods and preparing for the management of health systems in the future. Apparently, there was no considerable difference between the motivation of students and the program planners. The students' main motivation for studying MPH was a combination of various interests in research and health sciences issues. Therefore, considering the potential of this group of students, effective academic investment on MPH can have positive impact.

  10. Predicting Light-Duty Vehicle Fuel Economy as a Function of Highway Speed

    SciTech Connect

    Thomas, John; Hwang, Ho-Ling; West, Brian; Huff, Shean

    2013-04-08

    The www.fueleconomy.gov website offers information such as window label fuel economy for city, highway, and combined driving for all U.S.-legal light-duty vehicles from 1984 to the present. The site is jointly maintained by the U.S. Department of Energy and the U.S. Environmental Protection Agency (EPA), and also offers a considerable amount of consumer information and advice pertaining to vehicle fuel economy and energy related issues. Included with advice pertaining to driving styles and habits is information concerning the trend that as highway cruising speed is increased, fuel economy will degrade. An effort was undertaken to quantify this conventional wisdom through analysis of dynamometer testing results for 74 vehicles at steady state speeds from 50 to 80 mph. Using this experimental data, several simple models were developed to predict individual vehicle fuel economy and its rate of change over the 50-80 mph speed range interval. The models presented require a minimal number of vehicle attributes. The simplest model requires only the EPA window label highway mpg value (based on the EPA specified estimation method for 2008 and beyond). The most complex of these simple model uses vehicle coast-down test coefficients (from testing prescribed by SAE Standard J2263) known as the vehicle Target Coefficients, and the raw fuel economy result from the federal highway test. Statistical comparisons of these models and discussions of their expected usefulness and limitations are offered.

  11. Processing of DNA structures via DNA unwinding and branch migration by the S. cerevisiae Mph1 protein.

    PubMed

    Zheng, Xiao-Feng; Prakash, Rohit; Saro, Dorina; Longerich, Simonne; Niu, Hengyao; Sung, Patrick

    2011-10-10

    The budding yeast Mph1 protein, the putative ortholog of human FANCM, possesses a 3' to 5' DNA helicase activity and is capable of disrupting the D-loop structure to suppress chromosome arm crossovers in mitotic homologous recombination. Similar to FANCM, genetic studies have implicated Mph1 in DNA replication fork repair. Consistent with this genetic finding, we show here that Mph1 is able to mediate replication fork reversal, and to process the Holliday junction via DNA branch migration. Moreover, Mph1 unwinds 3' and 5' DNA Flap structures that bear key features of the D-loop. These biochemical results not only provide validation for a role of Mph1 in the repair of damaged replication forks, but they also offer mechanistic insights as to its ability to efficiently disrupt the D-loop intermediate.

  12. Speed limit of frozen pellets (H{sub 2}, D{sub 2}, and Ne) through single-loop and multiloop tubes and implications for fusion plasma research

    SciTech Connect

    Combs, S. K.; Griffith, A. E.; Foust, C. R.

    2001-01-01

    Frozen pellets (H{sub 2}, D{sub 2}, and Ne at 8 K) of nominal 2.7 mm diam were shot through a coiled tube (single loop of {approx}0.6 m diam and 8.5 mm bore), and the speed limit for survival was recorded for each pellet type. Intact H{sub 2} pellets were observed at speeds approaching 500 m/s; but neon pellets could not survive much more than 100 m/s. The speed limit for D{sub 2} pellets fell in the middle at {approx}300 m/s. Some D{sub 2} pellets were also shot through a 30 m coiled tube consisting of 11 loops (average loop diameter of {approx}0.8 m), and a speed limit of {approx}100 m/s was observed. Injection of frozen H{sub 2} or D{sub 2} pellets is commonly used for core fueling of magnetically confined plasmas, and frozen neon pellets are sometimes used for impurity transport studies in similar experiments. The results from these tests add to a pellet database for injection lines with single- and complex multiple-curved guide tubes. All of the information to date suggests that frozen pellets can be delivered reliably from a pellet source to any accessible plasma location on a fusion device via ''roller-coaster'' tubes as long as the pellet speed is maintained below a threshold limit.

  13. Developing core competencies for monitoring and evaluation tracks in South Asian MPH programs.

    PubMed

    Negandhi, Himanshu; Negandhi, Preeti; Tiwari, Ritika; Sharma, Anjali; Zodpey, Sanjay; Kulatilaka, Hemali; Tikyani, Sangeeta

    2015-08-05

    Monitoring and evaluation (M&E) provides vital information for decision-making and its structures, systems and processes are expected to be integrated throughout the life-cycle of public health programs. The acquisition of these skills should be developed in a structured manner and needs educational systems to identify core competencies in M&E teaching. This article presents our work on harmonizing M&E competencies for Masters level programs in the South Asian context and undertaking the global review of M&E track/ concentration offered in various Masters of Public Health (MPH) programs. Through an online search and snow-balling, we mapped institutions offering M&E tracks/ concentrations in Masters of Public Health (MPH) programs globally. We obtained detailed information about their M&E curriculum from university websites and brochures. The data on curricular contents was extracted and compiled. We analyzed the curricular contents using the framework for core competencies developed by the Association of Schools of Public Health (ASPH); and the Miller's triangle. This data was then used to inform a consultative exercise aimed at identifying core competencies for an M&E track/ concentration in MPH programs in the South Asian context. Our curricular review of M&E content within MPH programs globally showed that different domains or broad topic areas relating to M&E are covered differently across the programs. The quantitative sciences (Biostatistics and Epidemiology) and Health Policy and Management are covered in much greater depth than the other two domains (Social & Behavioral Sciences and Environmental Health Sciences). The identification of core competencies for an M&E track/ concentration in the South Asian context was undertaken through a consultative group exercise involving representation from 11 institutions across Bangladesh, India, Nepal and Sri Lanka. During the consultation, the group engaged in a focused discussion to reach consensus on a set of 15

  14. Full Bayesian evaluation of the safety effects of reducing the posted speed limit in urban residential area.

    PubMed

    Islam, Md Tazul; El-Basyouny, Karim

    2015-07-01

    Full Bayesian (FB) before-after evaluation is a newer approach than the empirical Bayesian (EB) evaluation in traffic safety research. While a number of earlier studies have conducted univariate and multivariate FB before-after safety evaluations and compared the results with the EB method, often contradictory conclusions have been drawn. To this end, the objectives of the current study were to (i) perform a before-after safety evaluation using both the univariate and multivariate FB methods in order to enhance our understanding of these methodologies, (ii) perform the EB evaluation and compare the results with those of the FB methods and (iii) apply the FB and EB methods to evaluate the safety effects of reducing the urban residential posted speed limit (PSL) for policy recommendation. In addition to three years of crash data for both the before and after periods, traffic volume, road geometry and other relevant data for both the treated and reference sites were collected and used. According to the model goodness-of-fit criteria, the current study found that the multivariate FB model for crash severities outperformed the univariate FB models. Moreover, in terms of statistical significance of the safety effects, the EB and FB methods led to opposite conclusions when the safety effects were relatively small with high standard deviation. Therefore, caution should be taken in drawing conclusions from the EB method. Based on the FB method, the PSL reduction was found effective in reducing crashes of all severities and thus is recommended for improving safety on urban residential collector roads.

  15. Limitations in intense exercise performance of athletes - effect of speed endurance training on ion handling and fatigue development.

    PubMed

    Hostrup, Morten; Bangsbo, Jens

    2016-09-27

    Mechanisms underlying fatigue development and limitations for performance during intense exercise have been intensively studied during the past couple of decades. Fatigue development may involve several interacting factors and depends on type of exercise undertaken and training level of the individual. Intense exercise (½-6 min) causes major ionic perturbations (Ca(2+) , Cl(-) , H(+) , K(+) , lactate(-) and Na(+) ) that may reduce sarcolemmal excitability, Ca(2+) release and force production of skeletal muscle. Maintenance of ion homeostasis is thus essential to sustain force production and power output during intense exercise. Regular speed endurance training (SET), i.e. exercise performed at intensities above that corresponding to maximum oxygen consumption (V̇O2, max ), enhances intense exercise performance. However, most of the studies that have provided mechanistic insight into the beneficial effects of SET have been conducted in untrained and recreationally active individuals, making extrapolation towards athletes' performance difficult. Nevertheless, recent studies indicate that only a few weeks of SET enhances intense exercise performance in highly trained individuals. In these studies, the enhanced performance was not associated with changes in V̇O2, max and muscle oxidative capacity, but rather with adaptations in muscle ion handling, including lowered interstitial concentrations of K(+) during and in recovery from intense exercise, improved lactate(-) -H(+) transport and H(+) regulation, and enhanced Ca(2+) release function. The purpose of this Topical Review is to provide an overview of the effect of SET and to discuss potential mechanisms underlying enhancements in performance induced by SET in already well-trained individuals with special emphasis on ion handling in skeletal muscle.

  16. Effectiveness of speed indicator devices: An observational study in South London.

    PubMed

    Walter, Louise; Broughton, Jeremy

    2011-07-01

    Speed indicator devices (SIDs) are vehicle activated signs displaying the real-time speeds of passing vehicles. They are part of the array of road safety measures for managing speeds on local authority roads in the United Kingdom. This paper documents an evaluation of the effectiveness of SIDs that was carried out in South London in 2008. SIDs were installed at 10 sites in South London for periods of between one and three weeks. The overall effect of the SIDs being installed was a reduction in vehicle speeds of 1.4mph and a significant reduction in the proportion of vehicles exceeding the speed limit. The research also investigated the distance over which the SIDs are effective and the effect on vehicle speeds once the SID is removed. The results showed that a speed reduction occurred over a distance of up to 400m and that once the SID is removed then, in general, the mean vehicle speeds returned to pre-SID levels by the end of the first week. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Framing the future's expert panel report on the MPH degree: a step backward?

    PubMed

    Schlaff, Anthony L

    2014-01-01

    Framing the Future Task Force, a group assembled by the Association of Schools and Programs of Public Health to identify key issues facing public health education as it enters its second 100 years, has recently released a report, "A Master of Public Health Degree for the 21st Century." The report calls for a significant shift in emphasis for the MPH degree away from a generalist, core curriculum in favor of a greater emphasis on areas of specialty. This commentary argues that such a shift would reverse the progress made since the 1988 Institute of Medicine report called on academia to better meet practice needs. Rather, the MPH of the 21st century should continue to focus on methods to better teach core competencies in public health practice at an advanced level.

  18. Coupling Multi-Component Models with MPH on Distributed MemoryComputer Architectures

    SciTech Connect

    He, Yun; Ding, Chris

    2005-03-24

    A growing trend in developing large and complex applications on today's Teraflop scale computers is to integrate stand-alone and/or semi-independent program components into a comprehensive simulation package. One example is the Community Climate System Model which consists of atmosphere, ocean, land-surface and sea-ice components. Each component is semi-independent and has been developed at a different institution. We study how this multi-component, multi-executable application can run effectively on distributed memory architectures. For the first time, we clearly identify five effective execution modes and develop the MPH library to support application development utilizing these modes. MPH performs component-name registration, resource allocation and initial component handshaking in a flexible way.

  19. MPH program at Manipal University, India-experiences, challenges, and lessons learned.

    PubMed

    Bhat, Hattangadi Vinod; Kamath, Ramachandra; Arunkumar, Govindakarnavar; Delzell, Elizabeth; Tipre, Meghan; Upadhyay, Divvy Kant; Sathiakumar, Nalini

    2013-01-01

    The UAB-ITREOH program has initiated a skill-based MPH program at Manipal University (MU), India, in 2009, to address the critical need for trained public health professionals and build institutional public health training capacity in the country. Funds from Fogarty have supported the curriculum development and specialized training of MU faculty to teach in the MPH program. The program has been successfully launched and is gaining momentum. The lessons learned from our experiences as well as several challenges faced from the initialization to execution of the program are described in the article. Government support is crucial for raising the profile of this program by accreditation, creating job opportunities and by recognizing these professionals as leaders in the public health sector. Copyright © 2012 Wiley Periodicals, Inc.

  20. MPH Program at Manipal University, India - Experiences, Challenges and Lessons Learned

    PubMed Central

    Bhat, H. Vinod; Kamath, Ramachandra; Arunkumar, G; Delzell, Elizabeth; Tipre, Meghan; Upadhyay, Divvy Kant; Sathiakumar, Nalini

    2012-01-01

    Background The UAB-ITREOH program has initiated a skill-based MPH program at Manipal University (MU), India, in 2009, to address the critical need for trained public health professionals and build institutional public health training capacity in the country. Methods Funds from Fogarty have supported the curriculum development and specialized training of MU faculty to teach in the MPH program. Results The program has been successfully launched and is gaining momentum. The lessons learned from our experiences as well as several challenges faced from the initialization to execution of the program are described in the paper. Conclusions Government support is crucial for raising the profile of this program by accreditation, creating job opportunities and by recognizing these professionals as leaders in the public health sector. PMID:22467350

  1. MTE1 Functions with MPH1 in Double-Strand Break Repair.

    PubMed

    Yimit, Askar; Kim, TaeHyung; Anand, Ranjith P; Meister, Sarah; Ou, Jiongwen; Haber, James E; Zhang, Zhaolei; Brown, Grant W

    2016-05-01

    Double-strand DNA breaks occur upon exposure of cells to ionizing radiation and certain chemical agents or indirectly through replication fork collapse at DNA damage sites. If left unrepaired, double-strand breaks can cause genome instability and cell death, and their repair can result in loss of heterozygosity. In response to DNA damage, proteins involved in double-strand break repair by homologous recombination relocalize into discrete nuclear foci. We identified 29 proteins that colocalize with recombination repair protein Rad52 in response to DNA damage. Of particular interest, Ygr042w/Mte1, a protein of unknown function, showed robust colocalization with Rad52. Mte1 foci fail to form when the DNA helicase gene MPH1 is absent. Mte1 and Mph1 form a complex and are recruited to double-strand breaks in vivo in a mutually dependent manner. MTE1 is important for resolution of Rad52 foci during double-strand break repair and for suppressing break-induced replication. Together our data indicate that Mte1 functions with Mph1 in double-strand break repair.

  2. Rad5-dependent DNA repair functions of the Saccharomyces cerevisiae FANCM protein homolog Mph1.

    PubMed

    Daee, Danielle L; Ferrari, Elisa; Longerich, Simonne; Zheng, Xiao-feng; Xue, Xiaoyu; Branzei, Dana; Sung, Patrick; Myung, Kyungjae

    2012-08-03

    Interstrand cross-links (ICLs) covalently link complementary DNA strands, block DNA replication, and transcription and must be removed to allow cell survival. Several pathways, including the Fanconi anemia (FA) pathway, can faithfully repair ICLs and maintain genomic integrity; however, the precise mechanisms of most ICL repair processes remain enigmatic. In this study we genetically characterized a conserved yeast ICL repair pathway composed of the yeast homologs (Mph1, Chl1, Mhf1, Mhf2) of four FA proteins (FANCM, FANCJ, MHF1, MHF2). This pathway is epistatic with Rad5-mediated DNA damage bypass and distinct from the ICL repair pathways mediated by Rad18 and Pso2. In addition, consistent with the FANCM role in stabilizing ICL-stalled replication forks, we present evidence that Mph1 prevents ICL-stalled replication forks from collapsing into double-strand breaks. This unique repair function of Mph1 is specific for ICL damage and does not extend to other types of damage. These studies reveal the functional conservation of the FA pathway and validate the yeast model for future studies to further elucidate the mechanism of the FA pathway.

  3. Understanding the Benefits and Limitations of Increasing Maximum Rotor Tip Speed for Utility-Scale Wind Turbines

    NASA Astrophysics Data System (ADS)

    Ning, A.; Dykes, K.

    2014-06-01

    For utility-scale wind turbines, the maximum rotor rotation speed is generally constrained by noise considerations. Innovations in acoustics and/or siting in remote locations may enable future wind turbine designs to operate with higher tip speeds. Wind turbines designed to take advantage of higher tip speeds are expected to be able to capture more energy and utilize lighter drivetrains because of their decreased maximum torque loads. However, the magnitude of the potential cost savings is unclear, and the potential trade-offs with rotor and tower sizing are not well understood. A multidisciplinary, system-level framework was developed to facilitate wind turbine and wind plant analysis and optimization. The rotors, nacelles, and towers of wind turbines are optimized for minimum cost of energy subject to a large number of structural, manufacturing, and transportation constraints. These optimization studies suggest that allowing for higher maximum tip speeds could result in a decrease in the cost of energy of up to 5% for land-based sites and 2% for offshore sites when using current technology. Almost all of the cost savings are attributed to the decrease in gearbox mass as a consequence of the reduced maximum rotor torque. Although there is some increased energy capture, it is very minimal (less than 0.5%). Extreme increases in tip speed are unnecessary; benefits for maximum tip speeds greater than 100-110 m/s are small to nonexistent.

  4. HERMES: a high-speed radar imaging system for inspection of bridge decks

    SciTech Connect

    Azevedo, S.G.

    1996-10-26

    Corrosion of rebar in concrete bridges causes subsurface cracks and is a major cause of structural degradation that necessitates repair or replacement. Early detection of corrosion effects can limit the location and extent of necessary repairs, while providing long-term information about the infrastructure status. Most current detection methods, however, are destructive of the road surface and require closing or restricting traffic while the tests are performed. A ground-penetrating radar imaging system has been designed and developed that will perform the nondestructive evaluation of road-bed cracking at traffic speeds; i.e., without the need to restrict traffic flow. The first-generation system (called the HERMES bridge inspector), consists of an offset-linear array of 64 impulse radar transceivers and associated electronics housed in a trailer. Computers in the trailer and in the towing vehicle control the data acquisition, processing, and display. Cross-road resolution is three centimeters at up to 30 cm in depth, while down-road resolution depends on speed; 3 cm below 20 mph up to 8 cm at 50 mph. A two-meter- wide path is inspected on each pass over the roadway. This paper, describes the design of this system, shows preliminary results, and lays out its deployment schedule.

  5. Limiter

    DOEpatents

    Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

    1984-10-19

    A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

  6. The novel mef(C)-mph(G) macrolide resistance genes are conveyed in the environment on various vectors.

    PubMed

    Sugimoto, Yuta; Suzuki, Satoru; Nonaka, Lisa; Boonla, Chanchai; Sukpanyatham, Nop; Chou, Hsin-Yiu; Wu, Jer-Horng

    2017-09-01

    The novel tandem genes mef(C) and mph(G) have been reported in marine bacteria in Japan. This paper aimed to characterise the extent of environmental distribution of mef(C) and mph(G) as well as their dissemination and persistence in aquatic bacterial communities. Erythromycin-resistant bacteria were isolated from Japan, Taiwan and Thailand aquaculture sites. The mef(C)-mph(G) genes were detected by PCR. The size of mobile genetic elements conveying mef(C) and mph(G) was examined by Southern blotting. The conjugation rate was assessed by filter mating. The mef(C)-mph(G) tandem genes were distributed in erythromycin-resistant isolates from aquaculture seawater in Japan and northern Taiwan and in animal farm wastewater in Thailand. A total of 29 bacterial isolates were positive for mef(C)-mph(G). The genes were found on vectors of various sizes. Partial sequencing of the traI relaxase gene revealed homology with a pAQU1-like plasmid, an IncA/C-type plasmid and an SXT/R391 family integrative conjugative element (SRI) as vectors. Thirteen isolates (45%) were positive for traI(pAQU-IncA/C-SRI), whereas the others were negative. The traI(pAQU-IncA/C-SRI)-positive isolates exhibited a higher transfer frequency (10(-4)-10(-5) transconjugants/donor) than traI(pAQU-IncA/C-SRI)-negative isolates (<10(-9)). These results suggest that mef(C)-mph(G) are coded on various vectors and are distributed among marine and wastewater bacteria in Asian countries. Vectors with traI(pAQU-IncA/C-SRI) play a role in the spread of mef(C)-mph(G). Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  7. Reducing the risk of rear-end collisions with infrastructure-to-vehicle (I2V) integration of variable speed limit control and adaptive cruise control system.

    PubMed

    Li, Ye; Wang, Hao; Wang, Wei; Liu, Shanwen; Xiang, Yun

    2016-08-17

    Adaptive cruise control (ACC) has been investigated recently to explore ways to increase traffic capacity, stabilize traffic flow, and improve traffic safety. However, researchers seldom have studied the integration of ACC and roadside control methods such as the variable speed limit (VSL) to improve safety. The primary objective of this study was to develop an infrastructure-to-vehicle (I2V) integrated system that incorporated both ACC and VSL to reduce rear-end collision risks on freeways. The intelligent driver model was firstly modified to simulate ACC behavior and then the VSL strategy used in this article was introduced. Next, the I2V system was proposed to integrate the 2 advanced techniques, ACC and VSL. Four scenarios of no control, VSL only, ACC only, and the I2V system were tested in simulation experiments. Time exposed time to collision (TET) and time integrated time to collision (TIT), 2 surrogate safety measures derived from time to collision (TTC), were used to evaluate safety issues associated with rear-end collisions. The total travel times of each scenario were also compared. The simulation results indicated that both the VSL-only and ACC-only methods had a positive impact on reducing the TET and TIT values (reduced by 53.0 and 58.6% and 59.0 and 65.3%, respectively). The I2V system combined the advantages of both ACC and VSL to achieve the most safety benefits (reduced by 71.5 and 77.3%, respectively). Sensitivity analysis of the TTC threshold also showed that the I2V system obtained the largest safety benefits with all of the TTC threshold values. The impact of different market penetration rates of ACC vehicles in I2V system indicated that safety benefits increase with an increase in ACC proportions. Compared to VSL-only and ACC-only scenarios, this integrated I2V system is more effective in reducing rear-end collision risks. The findings of this study provide useful information for traffic agencies to implement novel techniques to improve

  8. Limiter

    DOEpatents

    Cohen, Samuel A.; Hosea, Joel C.; Timberlake, John R.

    1986-01-01

    A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

  9. Graviton time delay and a speed limit for small black holes in Einstein-Gauss-Bonnet theory

    NASA Astrophysics Data System (ADS)

    Papallo, Giuseppe; Reall, Harvey S.

    2015-11-01

    Camanho, Edelstein, Maldacena and Zhiboedov have shown that gravitons can experience a negative Shapiro time delay, i.e. a time advance, in Einstein-Gauss-Bonnet theory. They studied gravitons propagating in singular "shock-wave" geometries. We study this effect for gravitons propagating in smooth black hole spacetimes. For a small enough black hole, we find that gravitons of appropriate polarisation, and small impact parameter, can experience time advance. Such gravitons can also exhibit a deflection angle less than π, characteristic of a repulsive short-distance gravitational interaction. We discuss problems with the suggestion that the time advance can be used to build a "time machine". In particular, we argue that a small black hole cannot be boosted to a speed arbitrarily close to the speed of light, as would be required in such a construction.

  10. Measurement of Aircraft Speed and Altitude

    DTIC Science & Technology

    1980-05-01

    3 00 00 1 .2 200 SI Fxample ’ Foro Vc 360 mph at: H - 25 000 ft, M =0.745-’ - • [’en, (a) if t at 25 000 ft is standard L " • • I ~~(-30.15° F), V...Supersonic Speeds. NASA TN D-1724, 1963. 16. Smith, Eugene S.: Askania Cine -Theocolite Data Reduction Manual. AFM•.C-TR-60-1, U.S. Air Force, Jan. 1960

  11. Yeast MPH1 gene functions in an error-free DNA damage bypass pathway that requires genes from Homologous recombination, but not from postreplicative repair.

    PubMed Central

    Schürer, K Anke; Rudolph, Christian; Ulrich, Helle D; Kramer, Wilfried

    2004-01-01

    The MPH1 gene from Saccharomyces cerevisiae, encoding a member of the DEAH family of proteins, had been identified by virtue of the spontaneous mutator phenotype of respective deletion mutants. Genetic analysis suggested that MPH1 functions in a previously uncharacterized DNA repair pathway that protects the cells from damage-induced mutations. We have now analyzed genetic interactions of mph1 with a variety of mutants from different repair systems with respect to spontaneous mutation rates and sensitivities to different DNA-damaging agents. The dependence of the mph1 mutator phenotype on REV3 and REV1 and the synergy with mutations in base and nucleotide excision repair suggest an involvement of MPH1 in error-free bypass of lesions. However, although we observed an unexpected partial suppression of the mph1 mutator phenotype by rad5, genetic interactions with other mutations in postreplicative repair imply that MPH1 does not belong to this pathway. Instead, mutations from the homologous recombination pathway were found to be epistatic to mph1 with respect to both spontaneous mutation rates and damage sensitivities. Determination of spontaneous mitotic recombination rates demonstrated that mph1 mutants are not deficient in homologous recombination. On the contrary, in an sgs1 background we found a pronounced hyperrecombination phenotype. Thus, we propose that MPH1 is involved in a branch of homologous recombination that is specifically dedicated to error-free bypass. PMID:15126389

  12. Compromised oxygen uptake in speed skaters during treadmill in-line skating.

    PubMed

    Rundell, K W

    1996-01-01

    The "sitting" posture of speed skating may result in compromised blood flow to the working muscles, thus limiting oxygen uptake. To examine this metabolic problem, male (N = 7) short track speed skaters performed running (TR), in-line skating upright (US), and in-line skating in the "sitting" position (LS) on a motor driven treadmill on randomized days. Each test consisted of four 4-min stages at 2.24, 2.68, 3.13, and 3.58 m.s-1 (5, 6, 7, and 8 mph) at 5% incline. After a brief rest, athletes performed at 4.03 m.s-1 (9 mph) with elevation increasing 1% each minute to exhaustion. Two on-ice 1000-m time trials (TT) were performed to assess the relationship between performance and laboratory measurements. Peak VO2 was lower during LS (57.2 +/- 2.7, 62.3 +/- 4.0, and 64.3 +/- 1.6; for LS, US, and TR, respectively; P < 0.05). At equivalent speeds, submaximal O2 uptake was lower for LS and blood lactate was higher (P < 0.05). LS peak VO2 (ml.kg-1.min-1) was strongly related to TT (P < 0.05). The depressed VO2 and higher blood lactate during LS may be related to decreased knee or trunk angle. Peak VO2 values during skating did not approach values during running. Evaluation of speed skaters in a sports-specific test is congruent with performance and demonstrates potential in addressing the unique physiological demands of the sport.

  13. Wind speed perception and risk.

    PubMed

    Agdas, Duzgun; Webster, Gregory D; Masters, Forrest J

    2012-01-01

    How accurately do people perceive extreme wind speeds and how does that perception affect the perceived risk? Prior research on human-wind interaction has focused on comfort levels in urban settings or knock-down thresholds. No systematic experimental research has attempted to assess people's ability to estimate extreme wind speeds and perceptions of their associated risks. We exposed 76 people to 10, 20, 30, 40, 50, and 60 mph (4.5, 8.9, 13.4, 17.9, 22.3, and 26.8 m/s) winds in randomized orders and asked them to estimate wind speed and the corresponding risk they felt. Multilevel modeling showed that people were accurate at lower wind speeds but overestimated wind speeds at higher levels. Wind speed perceptions mediated the direct relationship between actual wind speeds and perceptions of risk (i.e., the greater the perceived wind speed, the greater the perceived risk). The number of tropical cyclones people had experienced moderated the strength of the actual-perceived wind speed relationship; consequently, mediation was stronger for people who had experienced fewer storms. These findings provide a clearer understanding of wind and risk perception, which can aid development of public policy solutions toward communicating the severity and risks associated with natural disasters.

  14. Wind Speed Perception and Risk

    PubMed Central

    Agdas, Duzgun; Webster, Gregory D.; Masters, Forrest J.

    2012-01-01

    Background How accurately do people perceive extreme wind speeds and how does that perception affect the perceived risk? Prior research on human–wind interaction has focused on comfort levels in urban settings or knock-down thresholds. No systematic experimental research has attempted to assess people's ability to estimate extreme wind speeds and perceptions of their associated risks. Method We exposed 76 people to 10, 20, 30, 40, 50, and 60 mph (4.5, 8.9, 13.4, 17.9, 22.3, and 26.8 m/s) winds in randomized orders and asked them to estimate wind speed and the corresponding risk they felt. Results Multilevel modeling showed that people were accurate at lower wind speeds but overestimated wind speeds at higher levels. Wind speed perceptions mediated the direct relationship between actual wind speeds and perceptions of risk (i.e., the greater the perceived wind speed, the greater the perceived risk). The number of tropical cyclones people had experienced moderated the strength of the actual–perceived wind speed relationship; consequently, mediation was stronger for people who had experienced fewer storms. Conclusion These findings provide a clearer understanding of wind and risk perception, which can aid development of public policy solutions toward communicating the severity and risks associated with natural disasters. PMID:23226230

  15. Effects of wind speed on aerosol spray penetration in adult mosquito bioassay cages.

    PubMed

    Hoffmann, W Clint; Fritz, Bradley K; Farooq, Muhammad; Cooperband, Miriam F

    2008-09-01

    Bioassay cages are commonly used to assess efficacy of insecticides against adult mosquitoes in the field. To correlate adult mortality readings to insecticidal efficacy and/or spray application parameters properly, it is important to know how the cage used in the bioassay interacts with the spray cloud containing the applied insecticide. This study compared the size of droplets, wind speed, and amount of spray material penetrating cages and outside of cages in a wind tunnel at different wind speeds. Two bioassay cages, Center for Medical, Agricultural and Veterinary Entomology (CMAVE) and Circle, were evaluated. The screen materials used on these cages reduced the size of droplets, wind speed, and amount of spray material inside the cages as compared to the spray cloud and wind velocity outside of the cages. When the wind speed in the dispersion tunnel was set at 0.6 m/sec (1.3 mph), the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.045 m/sec (0.10 mph) and 0.075 m/sec (0.17 mph), respectively. At air velocities of 2.2 m/sec (4.9 mph) in the dispersion tunnel, the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.83 m/sec (1.86 mph) and 0.71 m/sec (1.59 mph), respectively. Consequently, there was a consistent 50-70% reduction of spray material penetrating the cages compared to the spray cloud that approached the cages. These results provide a better understanding of the impact of wind speed, cage design, and construction on ultra-low-volume spray droplets.

  16. Factors Associated with the Perception of Speed among Recreational Skiers

    PubMed Central

    Brunner, Friedrich; Ruedl, Gerhard; Kopp, Martin; Burtscher, Martin

    2015-01-01

    Background Skiers have to differ between slow to moderate and fast skiing speed to determine their skiing style according to the ISO 11088 standard for setting binding release values. Despite existing evidence that males ski significantly faster than females, no sex-specific factor was inserted into the ISO 11088 standard. Objective To evaluate factors potentially associated with the perception of individual skiing speed among recreational skiers. Methods Skiing speeds of 416 adult skiers (62% males,) were measured with a radar speed gun. Skiers were interviewed about their age, sex, skill level, risk taking behaviour and helmet use. Finally, skiers had to rate their perceived speed on one out of three speed categories (fast, moderate, slow). Results The measured mean speed of this cohort was 48.2±14.3 km/h (30.0±8.9 mph). A total of 32%, 52%, and 16% of skiers perceived their actual speed as fast, moderate and slow, respectively. Mean speed differed significantly between the 3 speed categories with a mean of about 53.5±13.7 km/h (33.2±8.5 mph) for fast, 47.6±14.0 km/h (29.6±8.7 mph) for moderate, and 39.4±12.2 km/h (24.5±7.6 mph) for slow skiing, respectively. Sex (η2 = .074), skill level (η2 = .035) and risk taking behavior (η2 = .033) showed significant differences of skiing speeds with regard to the 3 categories of speed perception (all p < .001) while age groups and ski helmet use did not. Males, more skilled skiers and risky skiers perceived their actual speed as fast, moderate and slow, when skiing up to 10 km/h (6 mph) faster compared to females, less skilled and cautious skiers. Conclusion The perception of skiing speed as fast, moderate or slow depends on sex, skill level, and risk taking behaviour. These findings should be considered when discussing the introduction of a sex factor into the ISO 11088 standard for setting binding release values. PMID:26121670

  17. 32 CFR 636.22 - Speed regulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the area. (iii) The flashing, yellow, caution lights are in operation. (3) Fort Stewart housing areas... County, 6 MPH Night Driving: Trails, 5 MPH (with headlights) Cross Country, 5 MPH Night Driving: Trails, 4 MPH (Black-out Drive) Cross County, 2.5 MPH (5) Parking lots, 10 miles per hour. (6)...

  18. Unsafe at Any (Wind) Speed?.

    NASA Astrophysics Data System (ADS)

    Schmidlin, Thomas; Hammer, Barbara; King, Paul; Ono, Yuichi; Miller, L. Scott; Thumann, Gregory

    2002-12-01

    The goal of this research was to examine the relative safety and stability of stationary motor vehicles exposed to severe winds. The focus was on private passenger vehicles. 1) The behavior of two instrumented storm-chase vehicles that were exposed to severe winds, 2) the behavior of 291 vehicles exposed to a tornado, and 3) the wind speed required to upset a sedan and a minivan exposed to winds in a wind tunnel were studied. A wind as strong as 47 m s1 (105 mph) has been measured by a storm-chase pickup truck and 44 m s1 (98 mph) by a storm chase sedan. The vehicles were not adversely affected by the wind. Also studied were 291 vehicles parked outdoors at homes struck by tornadoes, and the behavior of the vehicles was compared to the F-scale damage to the house. At sites with F1 or F2 damage, 72% of the vehicles were not moved by the wind and 96% were not tipped over. At sites with F3 or F4 damage, 50% were not moved by the wind and 82% were not tipped over. Wind tunnel tests on a sedan and minivan showed they were most vulnerable to upset (lifting of one tire from the ground) with wind directions near 45° and 135°, as measured from the front. When modeled with 5° of suspension tilt to the side, the sedan was found to be upset at wind speeds of 51-67 m s1 (115-150 mph), and the minivan was upset at wind speeds of 58-80 m s1 (130-180 mph). Although an underground shelter or sturdy building offer the best protection from severe winds, it is found that a vehicle may be a relatively stable place and may be safer than a mobile home or the outdoors. These findings may warrant changes to public recommendations made during tornado warnings and other severe storm situations.

  19. Take-off speed in jumping mantises depends on body size and a power-limited mechanism

    PubMed Central

    Doroshenko, M.; Cullen, D. A.; Burrows, M.

    2016-01-01

    ABSTRACT Many insects such as fleas, froghoppers and grasshoppers use a catapult mechanism to jump, and a direct consequence of this is that their take-off velocities are independent of their mass. In contrast, insects such as mantises, caddis flies and bush crickets propel their jumps by direct muscle contractions. What constrains the jumping performance of insects that use this second mechanism? To answer this question, the jumping performance of the mantis Stagmomantis theophila was measured through all its developmental stages, from 5 mg first instar nymphs to 1200 mg adults. Older and heavier mantises have longer hind and middle legs and higher take-off velocities than younger and lighter mantises. The length of the propulsive hind and middle legs scaled approximately isometrically with body mass (exponent=0.29 and 0.32, respectively). The front legs, which do not contribute to propulsion, scaled with an exponent of 0.37. Take-off velocity increased with increasing body mass (exponent=0.12). Time to accelerate increased and maximum acceleration decreased, but the measured power that a given mass of jumping muscle produced remained constant throughout all stages. Mathematical models were used to distinguish between three possible limitations to the scaling relationships: first, an energy-limited model (which explains catapult jumpers); second, a power-limited model; and third, an acceleration-limited model. Only the model limited by muscle power explained the experimental data. Therefore, the two biomechanical mechanisms impose different limitations on jumping: those involving direct muscle contractions (mantises) are constrained by muscle power, whereas those involving catapult mechanisms are constrained by muscle energy. PMID:27284067

  20. Take-off speed in jumping mantises depends on body size and a power-limited mechanism.

    PubMed

    Sutton, G P; Doroshenko, M; Cullen, D A; Burrows, M

    2016-07-15

    Many insects such as fleas, froghoppers and grasshoppers use a catapult mechanism to jump, and a direct consequence of this is that their take-off velocities are independent of their mass. In contrast, insects such as mantises, caddis flies and bush crickets propel their jumps by direct muscle contractions. What constrains the jumping performance of insects that use this second mechanism? To answer this question, the jumping performance of the mantis Stagmomantis theophila was measured through all its developmental stages, from 5 mg first instar nymphs to 1200 mg adults. Older and heavier mantises have longer hind and middle legs and higher take-off velocities than younger and lighter mantises. The length of the propulsive hind and middle legs scaled approximately isometrically with body mass (exponent=0.29 and 0.32, respectively). The front legs, which do not contribute to propulsion, scaled with an exponent of 0.37. Take-off velocity increased with increasing body mass (exponent=0.12). Time to accelerate increased and maximum acceleration decreased, but the measured power that a given mass of jumping muscle produced remained constant throughout all stages. Mathematical models were used to distinguish between three possible limitations to the scaling relationships: first, an energy-limited model (which explains catapult jumpers); second, a power-limited model; and third, an acceleration -: limited model. Only the model limited by muscle power explained the experimental data. Therefore, the two biomechanical mechanisms impose different limitations on jumping: those involving direct muscle contractions (mantises) are constrained by muscle power, whereas those involving catapult mechanisms are constrained by muscle energy.

  1. Insights into resistance mechanism of the macrolide biosensor protein MphR(A) binding to macrolide antibiotic erythromycin by molecular dynamics simulation

    NASA Astrophysics Data System (ADS)

    Feng, Tingting; Zhang, Yanjun; Ding, Jing-Na; Fan, Song; Han, Ju-Guang

    2015-12-01

    Macrolide biosensor protein MphR(A) has been known as a key regulatory protein in metabolite sensing and genetic expression regulating. MphR(A) protein binds to macrolide antibiotic erythromycin (Ery) and releases the gene operon, thus activates expression of the mphA gene and initiates Ery resistance. The two mutant amino acid residues (V66L and V126L) might potentially disrupt Ery binding to MphR(A). In these studies, the binding of macrolide antibiotic Ery to wild type (Wt) MphR(A) and double mutant (V66L/V126L) MphR(A) are explored by molecular dynamics simulations. Compared to the Apo-MphR(A) protein and Wt-MphR(A)-Ery complex, many interesting effects owing to the double mutant (V66L/V126L) are discovered. In the case of Ery, Helix I which plays an important role in transcription shows itself a right-hand α helix in Wt-MphR(A)-Ery, whereas the activated helix is broken down in double mutant-V66L/V126L-MphR(A)-Ery. The calculated results exhibit that the double mutant V66L/V126L reduces the binding affinity of the V66L/V126L-MphR(A) to Ery, resulting in the block of Ery resistance. The binding free energy decomposition analysis reveals that the decrease of the binding affinity for the variant V66L/V126L-MphR(A)-Ery is mainly attributed to the gas phase electrostatic energies. The residue Leu66, Thr154, and Arg122 enhance the binding affinity of V66L/V126L-MphR(A) to Ery. The residues Tyr103 and His147 contributes mainly to binding energies in the Wt-MphR(A)-Ery complex, whereas the two residues have no contribution to the binding free energy inV66L/V126L-MphR(A)-Ery complex. Our study gives useful insights into the nature of amino acids mutation effect, the mechanism of blocking drug resistance at the atomic level and the characteristics in binding affinity for Ery to double mutant (V66L/V126L) MphR(A), which will contribute to the design of more effective macrolide antibiotics.

  2. Insights into resistance mechanism of the macrolide biosensor protein MphR(A) binding to macrolide antibiotic erythromycin by molecular dynamics simulation.

    PubMed

    Feng, Tingting; Zhang, Yanjun; Ding, Jing-Na; Fan, Song; Han, Ju-Guang

    2015-12-01

    Macrolide biosensor protein MphR(A) has been known as a key regulatory protein in metabolite sensing and genetic expression regulating. MphR(A) protein binds to macrolide antibiotic erythromycin (Ery) and releases the gene operon, thus activates expression of the mphA gene and initiates Ery resistance. The two mutant amino acid residues (V66L and V126L) might potentially disrupt Ery binding to MphR(A). In these studies, the binding of macrolide antibiotic Ery to wild type (Wt) MphR(A) and double mutant (V66L/V126L) MphR(A) are explored by molecular dynamics simulations. Compared to the Apo-MphR(A) protein and Wt-MphR(A)-Ery complex, many interesting effects owing to the double mutant (V66L/V126L) are discovered. In the case of Ery, Helix I which plays an important role in transcription shows itself a right-hand α helix in Wt-MphR(A)-Ery, whereas the activated helix is broken down in double mutant-V66L/V126L-MphR(A)-Ery. The calculated results exhibit that the double mutant V66L/V126L reduces the binding affinity of the V66L/V126L-MphR(A) to Ery, resulting in the block of Ery resistance. The binding free energy decomposition analysis reveals that the decrease of the binding affinity for the variant V66L/V126L-MphR(A)-Ery is mainly attributed to the gas phase electrostatic energies. The residue Leu66, Thr154, and Arg122 enhance the binding affinity of V66L/V126L-MphR(A) to Ery. The residues Tyr103 and His147 contributes mainly to binding energies in the Wt-MphR(A)-Ery complex, whereas the two residues have no contribution to the binding free energy inV66L/V126L-MphR(A)-Ery complex. Our study gives useful insights into the nature of amino acids mutation effect, the mechanism of blocking drug resistance at the atomic level and the characteristics in binding affinity for Ery to double mutant (V66L/V126L) MphR(A), which will contribute to the design of more effective macrolide antibiotics.

  3. Investigation of Multiwavelength Optical Power Limiting Amplifier and its Applications in High-Speed Sonet Wavelength-Division Multiplexing Self-Healing Ring Network

    NASA Astrophysics Data System (ADS)

    Chen, Yung-Kuang; Liaw, Shien-Kuei; Chi, Sien

    A multiwavelength optical power limiting amplifier (OLA) for high-speed SONET self-healing ring (SHR) networks is reported. Four possible OLA configurations are investigated. We find that the configuration consisting of a high-gain common erbium-doped fiber amplifier (EDFA) followed by a grating-multiplexed multiple-power-EDFA module is the best scheme for multiwavelength power-limiting operation. A constant channel output of > 11 dBm, small inter-channel power variation of ≤ 0.5 dB, and fairly low noise figure are obtained within a large dynamic range of 45 dB. Network application in a SHR network is also demonstrated and the ring size of 150 km served by a single three-WDM-channel OLA at channel rates of 2.488 Gb/s is obtained.

  4. 14 CFR 142.65 - Limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... used during line operational simulation for evaluation and line-oriented flight training only to...) When flight testing, flight checking, or line operational simulation is being conducted, the...

  5. 14 CFR 142.65 - Limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... used during line operational simulation for evaluation and line-oriented flight training only to...) When flight testing, flight checking, or line operational simulation is being conducted, the...

  6. 14 CFR 142.65 - Limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... used during line operational simulation for evaluation and line-oriented flight training only to...) When flight testing, flight checking, or line operational simulation is being conducted, the...

  7. Partial body weight support treadmill training speed influences paretic and non-paretic leg muscle activation, stride characteristics, and ratings of perceived exertion during acute stroke rehabilitation.

    PubMed

    Burnfield, Judith M; Buster, Thad W; Goldman, Amy J; Corbridge, Laura M; Harper-Hanigan, Kellee

    2016-06-01

    Intensive task-specific training is promoted as one approach for facilitating neural plastic brain changes and associated motor behavior gains following neurologic injury. Partial body weight support treadmill training (PBWSTT), is one task-specific approach frequently used to improve walking during the acute period of stroke recovery (<1month post infarct). However, only limited data have been published regarding the relationship between training parameters and physiologic demands during this early recovery phase. To examine the impact of four walking speeds on stride characteristics, lower extremity muscle demands (both paretic and non-paretic), Borg ratings of perceived exertion (RPE), and blood pressure. A prospective, repeated measures design was used. Ten inpatients post unilateral stroke participated. Following three familiarization sessions, participants engaged in PBWSTT at four predetermined speeds (0.5, 1.0, 1.5 and 2.0mph) while bilateral electromyographic and stride characteristic data were recorded. RPE was evaluated immediately following each trial. Stride length, cadence, and paretic single limb support increased with faster walking speeds (p⩽0.001), while non-paretic single limb support remained nearly constant. Faster walking resulted in greater peak and mean muscle activation in the paretic medial hamstrings, vastus lateralis and medial gastrocnemius, and non-paretic medial gastrocnemius (p⩽0.001). RPE also was greatest at the fastest compared to two slowest speeds (p<0.05). During the acute phase of stroke recovery, PBWSTT at the fastest speed (2.0mph) promoted practice of a more optimal gait pattern with greater intensity of effort as evidenced by the longer stride length, increased between-limb symmetry, greater muscle activation, and higher RPE compared to training at the slowest speeds. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Coupling of water and carbon transport in trees: -Could water limitations of phloem transport speed up carbon starvation and tree mortality?

    NASA Astrophysics Data System (ADS)

    Sevanto, S.; McDowell, N. G.; Dickman, L. T.; Pangle, R.; Pockman, W.

    2011-12-01

    Understanding the mechanisms behind tree mortality is increasingly important because climate change appears to be increasing drought severity and duration worldwide, with concomitant increases in mortality. Carbon starvation is one of the mechanisms suggested to be responsible for mortality, especially for species that close stomata at low xylem water tensions. Such plants would be under negative carbon balance during drought. Carbohydrate transport in plants relies on the availability of apoplastic water and therefore, shortage of water could lead to inability to distribute sugars and speed up carbon starvation even if carbohydrate reserves existed. To test these ideas we conducted a greenhouse study where pinon pine (Pinus edulis) trees were killed using two treatments: water limitation (complete drought) and carbon limitation (complete darkness). We collected tissue samples for non-structural carbohydrate content analysis weekly and monitored changes in xylem and phloem water potentials using stem diameter variation measurements. To follow changes in the physiological status of the trees we measured shoot gas exchange, leaf water potential and sap flow rate. Carbon-limited trees continued respiring at relatively high rates and maintained both xylem and phloem transport despite rapidly diminishing carbohydrate pools. Water-limited trees, on the other hand, exhibited reduced respiration and xylem and phloem transport rates as soon as drought inhibited stomatal opening; even before any significant drop in leaf water potential. This suggests that respirationmetabolic rate is strongly controlled by soil water availability, and instead of speeding up mortality, reduced carbohydrate transport and utilization rate may be a valuable strategy to enhance tree survival during long droughts.

  9. A transposable class I composite transposon carrying mph (methyl parathion hydrolase) from Pseudomonas sp. strain WBC-3.

    PubMed

    Wei, Min; Zhang, Jun-Jie; Liu, Hong; Wang, Shu-Jun; Fu, He; Zhou, Ning-Yi

    2009-03-01

    Pseudomonas sp. strain WBC-3 utilizes methyl parathion (O,O-dimethyl O-p-nitrophenol phosphorothioate) or para-nitrophenol as the sole source of carbon, nitrogen and energy. A gene encoding methyl parathion hydrolase (MPH) had been characterized previously and found to be located on a typical class I composite transposon that comprised IS6100 (Tnmph). In this study, the transposability of this transposon was confirmed by transposition assays in two distinct mating-out systems. Tnmph was demonstrated to transpose efficiently in a random manner in Pseudomonas putida PaW340 by Southern blot and in Ralstonia sp. U2 by sequence analysis of the Tnmph insertion sites, both exhibiting MPH activity. The linkage of the mph-like gene with IS6100, together with the transposability of Tnmph, as well as its capability to transpose in other phylogenetically divergent bacterial species, suggest that Tnmph may contribute to the wide distribution of mph-like genes and the adaptation of bacteria to organophosphorus compounds.

  10. On the MAC/network/energy performance evaluation of Wireless Sensor Networks: Contrasting MPH, AODV, DSR and ZTR routing protocols.

    PubMed

    Del-Valle-Soto, Carolina; Mex-Perera, Carlos; Orozco-Lugo, Aldo; Lara, Mauricio; Galván-Tejada, Giselle M; Olmedo, Oscar

    2014-12-02

    Wireless Sensor Networks deliver valuable information for long periods, then it is desirable to have optimum performance, reduced delays, low overhead, and reliable delivery of information. In this work, proposed metrics that influence energy consumption are used for a performance comparison among our proposed routing protocol, called Multi-Parent Hierarchical (MPH), the well-known protocols for sensor networks, Ad hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR), and Zigbee Tree Routing (ZTR), all of them working with the IEEE 802.15.4 MAC layer. Results show how some communication metrics affect performance, throughput, reliability and energy consumption. It can be concluded that MPH is an efficient protocol since it reaches the best performance against the other three protocols under evaluation, such as 19.3% reduction of packet retransmissions, 26.9% decrease of overhead, and 41.2% improvement on the capacity of the protocol for recovering the topology from failures with respect to AODV protocol. We implemented and tested MPH in a real network of 99 nodes during ten days and analyzed parameters as number of hops, connectivity and delay, in order to validate our Sensors 2014, 14 22812 simulator and obtain reliable results. Moreover, an energy model of CC2530 chip is proposed and used for simulations of the four aforementioned protocols, showing that MPH has 15.9% reduction of energy consumption with respect to AODV, 13.7% versus DSR, and 5% against ZTR.

  11. Teaching Note--Educating Public Health Social Work Professionals: Results from an MSW/MPH Program Outcomes Study

    ERIC Educational Resources Information Center

    Ruth, Betty J.; Marshall, Jamie Wyatt; Velásquez, Esther E. M.; Bachman, Sara S.

    2015-01-01

    Dual-degree programs in public health and social work continue to proliferate, yet there has been little research on master's of social work (MSW)/master's of public health (MPH) graduates. The purpose of this study was to describe and better understand the self-reported professional experiences, identities, roles, and outcomes associated with 1…

  12. Effects of MPH-OROS on the Organizational, Time Management, and Planning Behaviors of Children with ADHD

    ERIC Educational Resources Information Center

    Abikoff, Howard; Nissley-Tsiopinis, Jenelle; Gallagher, Richard; Zambenedetti, Maurizio; Seyffert, Michael; Boorady, Roy; McCarthy, John

    2009-01-01

    A double-blind, placebo-controlled, crossover design study was done to evaluate the effects of methylphenidate-osmotic-release oral systems (MPH-OROS) on the organization, time management, and planning (OTMP) of children with attention deficit hyperactivity disorder (ADHD). Results show significant improvements on the OTMP of children with ADHD in…

  13. On the MAC/Network/Energy Performance Evaluation of Wireless Sensor Networks: Contrasting MPH, AODV, DSR and ZTR Routing Protocols

    PubMed Central

    Del-Valle-Soto, Carolina; Mex-Perera, Carlos; Orozco-Lugo, Aldo; Lara, Mauricio; Galván-Tejada, Giselle M.; Olmedo, Oscar

    2014-01-01

    Wireless Sensor Networks deliver valuable information for long periods, then it is desirable to have optimum performance, reduced delays, low overhead, and reliable delivery of information. In this work, proposed metrics that influence energy consumption are used for a performance comparison among our proposed routing protocol, called Multi-Parent Hierarchical (MPH), the well-known protocols for sensor networks, Ad hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR), and Zigbee Tree Routing (ZTR), all of them working with the IEEE 802.15.4 MAC layer. Results show how some communication metrics affect performance, throughput, reliability and energy consumption. It can be concluded that MPH is an efficient protocol since it reaches the best performance against the other three protocols under evaluation, such as 19.3% reduction of packet retransmissions, 26.9% decrease of overhead, and 41.2% improvement on the capacity of the protocol for recovering the topology from failures with respect to AODV protocol. We implemented and tested MPH in a real network of 99 nodes during ten days and analyzed parameters as number of hops, connectivity and delay, in order to validate our simulator and obtain reliable results. Moreover, an energy model of CC2530 chip is proposed and used for simulations of the four aforementioned protocols, showing that MPH has 15.9% reduction of energy consumption with respect to AODV, 13.7% versus DSR, and 5% against ZTR. PMID:25474377

  14. Effects of MPH-OROS on the Organizational, Time Management, and Planning Behaviors of Children with ADHD

    ERIC Educational Resources Information Center

    Abikoff, Howard; Nissley-Tsiopinis, Jenelle; Gallagher, Richard; Zambenedetti, Maurizio; Seyffert, Michael; Boorady, Roy; McCarthy, John

    2009-01-01

    A double-blind, placebo-controlled, crossover design study was done to evaluate the effects of methylphenidate-osmotic-release oral systems (MPH-OROS) on the organization, time management, and planning (OTMP) of children with attention deficit hyperactivity disorder (ADHD). Results show significant improvements on the OTMP of children with ADHD in…

  15. Teaching Note--Educating Public Health Social Work Professionals: Results from an MSW/MPH Program Outcomes Study

    ERIC Educational Resources Information Center

    Ruth, Betty J.; Marshall, Jamie Wyatt; Velásquez, Esther E. M.; Bachman, Sara S.

    2015-01-01

    Dual-degree programs in public health and social work continue to proliferate, yet there has been little research on master's of social work (MSW)/master's of public health (MPH) graduates. The purpose of this study was to describe and better understand the self-reported professional experiences, identities, roles, and outcomes associated with 1…

  16. Molecular evolution under increasing transposable element burden in Drosophila: A speed limit on the evolutionary arms race

    PubMed Central

    2011-01-01

    Background Genome architecture is profoundly influenced by transposable elements (TEs), and natural selection against their harmful effects is a critical factor limiting their spread. Genome defense by the piRNA silencing pathway also plays a crucial role in limiting TE proliferation. How these two forces jointly determine TE abundance is not well understood. To shed light on the nature of factors that predict TE success, we test three distinct hypotheses in the Drosophila genus. First, we determine whether TE abundance and relaxed genome-wide purifying selection on protein sequences are positively correlated. This serves to test the hypothesis that variation in TE abundance in the Drosophila genus can be explained by the strength of natural selection, relative to drift, acting in parallel against mildly deleterious non-synonymous mutations. Second, we test whether increasing TE abundance is correlated with an increased rate of amino-acid evolution in genes encoding the piRNA machinery, as might be predicted by an evolutionary arms race model. Third, we test whether increasing TE abundance is correlated with greater codon bias in genes of the piRNA machinery. This is predicted if increasing TE abundance selects for increased efficiency in the machinery of genome defense. Results Surprisingly, we find neither of the first two hypotheses to be true. Specifically, we found that genome-wide levels of purifying selection, measured by the ratio of non-synonymous to synonymous substitution rates (ω), were greater in species with greater TE abundance. In addition, species with greater TE abundance have greater levels of purifying selection in the piRNA machinery. In contrast, it appears that increasing TE abundance has primarily driven adaptation in the piRNA machinery by increasing codon bias. Conclusions These results indicate that within the Drosophila genus, a historically reduced strength of selection relative to drift is unlikely to explain patterns of increased TE

  17. Effect of Intensive Blood Pressure Control on Gait Speed and Mobility Limitation in Adults 75 Years or Older: A Randomized Clinical Trial.

    PubMed

    Odden, Michelle C; Peralta, Carmen A; Berlowitz, Dan R; Johnson, Karen C; Whittle, Jeffrey; Kitzman, Dalane W; Beddhu, Srinivasan; Nord, John W; Papademetriou, Vasilios; Williamson, Jeff D; Pajewski, Nicholas M

    2017-04-01

    Intensive blood pressure (BP) control confers a benefit on cardiovascular morbidity and mortality; whether it affects physical function outcomes is unknown. To examine the effect of intensive BP control on changes in gait speed and mobility status. This randomized, clinical trial included 2636 individuals 75 years or older with hypertension and no history of type 2 diabetes or stroke who participated in the Systolic Blood Pressure Intervention Trial (SPRINT). Data were collected from November 8, 2010, to December 1, 2015. Analysis was based on intention to treat. Participants were randomized to intensive treatment with a systolic BP target of less than 120 mm Hg (n = 1317) vs standard treatment with a BP target of less than 140 mm Hg (n = 1319). Gait speed was measured using a 4-m walk test. Self-reported information concerning mobility was obtained from items on the Veterans RAND 12-Item Health Survey and the EQ-5D. Mobility limitation was defined as a gait speed less than 0.6 meters per second (m/s) or self-reported limitations in walking and climbing stairs. Among the 2629 participants in whom mobility status could be defined (996 women [37.9%]; 1633 men [62.1%]; mean [SD] age, 79.9 [4.0] years), median (interquartile range) follow-up was 3 (2-3) years. No difference in mean gait speed decline was noted between the intensive- and standard-treatment groups (mean difference, 0.0004 m/s per year; 95% CI, -0.005 to 0.005; P = .88). No evidence of any treatment group differences in subgroups defined by age, sex, race or ethnicity, baseline systolic BP, chronic kidney disease, or a history of cardiovascular disease were found. A modest interaction was found for the Veterans RAND 12-Item Health Survey Physical Component Summary score, although the effect did not reach statistical significance in either subgroup, with mean differences of 0.004 (95% CI, -0.002 to 0.010) m/s per year among those with scores of at least 40 and -0.008 (95% CI, -0.016 to 0

  18. Initial Piloted Simulation Evaluation of the Reference-H High-Speed Civil Transport Design During Takeoff and Recovery From Limit Flight Conditions

    NASA Technical Reports Server (NTRS)

    Glaab, Louis J.

    1999-01-01

    An initial assessment of a proposed High-Speed Civil Transport (HSCT) was conducted in the fall of 1995 at the NASA Langley Research Center. This configuration, known as the Industry Reference-H (Ref.-H), was designed by the Boeing Aircraft Company as part of their work in the High Speed Research program. It included a conventional tail, a cranked-arrow wing, four mixed-flow turbofan engines, and capacity for transporting approximately 300 passengers. The purpose of this assessment was to evaluate and quantify operational aspects of the Reference-H configuration from a pilot's perspective with the additional goal of identifying design strengths as well as any potential configuration deficiencies. This study was aimed at evaluating the Ref.-H configuration at many points of the aircraft's envelope to determine the suitability of the vehicle to accomplish typical mission profiles as well as emergency or envelope-limit conditions. Pilot-provided Cooper-Harper ratings and comments constituted the primary vehicle evaluation metric. The analysis included simulated real-time piloted evaluations, performed in a 6 degree of freedom motion base NASA Langley Visual-Motion Simulator, combined with extensive bath analysis. The assessment was performed using the third major release of the simulation data base (known as Ref.-H cycle 2B).

  19. Cognitive Functioning and Walking Speed in Older Adults as Predictors of Limitations in Self-Reported Instrumental Activity of Daily Living: Prospective Findings from the Obu Study of Health Promotion for the Elderly

    PubMed Central

    Makizako, Hyuma; Shimada, Hiroyuki; Doi, Takehiko; Tsutsumimoto, Kota; Lee, Sangyoon; Hotta, Ryo; Nakakubo, Sho; Harada, Kazuhiro; Lee, Sungchul; Bae, Seongryu; Harada, Kenji; Suzuki, Takao

    2015-01-01

    Our aim was to determine whether baseline measures of cognitive functioning, walking speed, and depressive status are independent predictors of limitations in instrumental activities of daily living (IADL) in older adults. The cross-sectional study involved 1329 community-dwelling adults, aged 75 years or older. At baseline, the Mini-Mental State Examination (MMSE), Symbol Digit Substitution Test (SDST), Geriatric Depressive Scale (GDS), and a word list memory task were completed, and self-reported IADLs and walking speed were recorded. The longitudinal study involved 948 participants without baseline IADL limitation, which was assessed at baseline and 15-month follow up, using the three Kihon Checklist subitems. In cross-sectional analyses, participants with IADL limitation demonstrated greater GDS scores, slower walking speeds, and lower MMSE, word list memory task, and SDST (only for women) scores relative to those without IADL limitation. In the longitudinal analyses, baseline walking speed (men: OR 0.98; women: OR 0.97, p < 0.05) and word list memory task scores (men: OR 0.84; women: OR 0.83, p < 0.05) in both sexes and SDST scores in women (OR 0.96, p = 0.04) were independent predictors of subsequent IADL limitation. Walking speed, memory, and processing speed may be independent predictors of IADL limitation in older adults. PMID:25768239

  20. Analytical characterization and pharmacological evaluation of the new psychoactive substance 4-fluoromethylphenidate (4F-MPH) and differentiation between the (±)-threo and (±)-erythro diastereomers.

    PubMed

    McLaughlin, Gavin; Morris, Noreen; Kavanagh, Pierce V; Power, John D; Dowling, Geraldine; Twamley, Brendan; O'Brien, John; Hessman, Gary; Murphy, Brian; Walther, Donna; Partilla, John S; Baumann, Michael H; Brandt, Simon D

    2017-03-01

    Misuse of (±)-threo-methylphenidate (methyl-2-phenyl-2-(piperidin-2-yl)acetate; Ritalin®; MPH) has long been acknowledged, but the appearance of MPH analogs in the form of 'research chemicals' has only emerged in more recent years. 4-Fluoromethylphenidate (4F-MPH) is one of these recent examples. This study presents the identification and analytical characterization of two powdered 4F-MPH products that were obtained from an online vendor in 2015. Interestingly, the products appeared to have originated from two distinct batches given that one product consisted of (±)-threo-4F-MPH isomers whereas the second sample consisted of a mixture of (±)-threo and (±)-erythro 4F-MPH. Monoamine transporter studies using rat brain synaptosomes revealed that the biological activity of the 4F-MPH mixture resided with the (±)-threo and not the (±)-erythro isomers based on higher potencies determined for blockage of dopamine uptake (IC50 4F-MPHmixture  = 66 nM vs. IC50 (±)-threo = 61 nM vs. IC50 (±)-erythro = 8,528 nM) and norepinephrine uptake (IC50 4F-MPHmixture  = 45 nM vs. (±)-threo = 31 nM vs. IC50 (±)-erythro = 3,779 nM). In comparison, MPH was three times less potent than (±)-threo-4F-MPH at the dopamine transporter (IC50  = 131 nM) and around 2.5 times less potent at the norepinephrine transporter (IC50  = 83 nM). Both substances were catecholamine selective with IC50 values of 8,805 nM and >10,000 nM for (±)-threo-4F-MPH and MPH at the serotonin transporter. These findings suggest that the psychostimulant properties of (±)-threo-4F-MPH might be more potent in humans than MPH. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Principles for planning the teaching of health promotion in an MPH course.

    PubMed

    Donchin, Milka

    2002-01-01

    The Ottawa Charter on Health Promotion defined the term Health Promotion as "the process of enabling people to increase control over, and to improve, their health". It also specifies that "to reach a state of complete physical mental and social well-being, an individual or group must be able to identify and to realize aspirations, to satisfy needs, and to change or cope with the environment". Three main strategies for promoting health were stated: advocacy, enabling, and mediating. A great emphasis was put on policy. The Jakarta Declaration at the 4th International Conference on Health Promotion in 1997 reconfirmed the Ottawa Charter and added to it that "Health Promotion is carried out by and with people, not on or to people". The learning objectives of health promotion should refer to the values and strategies of 'Health 21', to the strategies and areas of action in health promotion as specified in the Ottawa Charter, and it should be relevant to the needs of the society that the participants are going to serve. The main goal of a training program in health promotion should be to develop competence in health promotion. "Competence" refers to the combination of three domains: attitudes, knowledge, and skills. Each school of public health or planners of an MPH course should decide upon the right mix of these three domains, according to their institute's mission and goals.

  2. Speed(s).

    ERIC Educational Resources Information Center

    Levy-Leblond, Jean-Marc

    1980-01-01

    Presents three simple distinct operational procedures for transforming the empirical notion of speed into a formal concept. The relationship between these three procedures and Galilean velocity and Einsteinian relativity is also included. (HM)

  3. Speed Management Strategies; A Systematic Review

    PubMed Central

    Sadeghi-Bazargani, Homayoun; Saadati, Mohammad

    2016-01-01

    Objective: To systematically identify the various methods of speed management and their effects. Methods: A systematic search was performed in Science Direct, Ovid Medline, Scopus, PubMed and ProQuest databases from April to June 2015. Hand searching and reference of selected articles were used to improve article identification. Articles published after 1990 which had reported on efficacy/effectiveness of speed management strategies were included. Data were extracted using pre-defined extraction table. Results: Of the 803 retrieved articles, 22 articles were included in this review. Most of the included articles (63%) had before-after design and were done in European countries. Speed cameras, engineering schemes, intelligent speed adaption (ISA), speed limits and zones, vehicle activated sign and integrated strategies were the most common strategies reported in the literature. Various strategies had different effects on mean speed of the vehicles ranging from 1.6 to 10 km/h. Moreover, 8-65% and 11-71% reduction was reported in person injured accidents and fatal accidents, respectively as a result of employing various strategies. Conclusion: Literature revealed positive effects of various speed management strategies. Using various strategies was mostly dependent on road characteristics, driver’s attitude about the strategy as well as economic and technological capabilities of the country. Political support is considered as a main determinant in selecting speed management strategies. PMID:27540546

  4. Innovating in health care management education: development of an accelerated MBA and MPH degree program at Yale.

    PubMed

    Pettigrew, Melinda M; Forman, Howard P; Pistell, Anne F; Nembhard, Ingrid M

    2015-03-01

    Increasingly, there is recognition of the need for individuals with expertise in both management and public health to help health care organizations deliver high-quality and cost-effective care. The Yale School of Public Health and Yale School of Management began offering an accelerated Master of Business Administration (MBA) and Master of Public Health (MPH) joint degree program in the summer of 2014. This new program enables students to earn MBA and MPH degrees simultaneously from 2 fully accredited schools in 22 months. Students will graduate with the knowledge and skills needed to become innovative leaders of health care organizations. We discuss the rationale for the program, the developmental process, the curriculum, benefits of the program, and potential challenges.

  5. Quantifying the causal effects of 20mph zones on road casualties in London via doubly robust estimation.

    PubMed

    Li, Haojie; Graham, Daniel J

    2016-08-01

    This paper estimates the causal effect of 20mph zones on road casualties in London. Potential confounders in the key relationship of interest are included within outcome regression and propensity score models, and the models are then combined to form a doubly robust estimator. A total of 234 treated zones and 2844 potential control zones are included in the data sample. The propensity score model is used to select a viable control group which has common support in the covariate distributions. We compare the doubly robust estimates with those obtained using three other methods: inverse probability weighting, regression adjustment, and propensity score matching. The results indicate that 20mph zones have had a significant causal impact on road casualty reduction in both absolute and proportional terms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Innovating in Health Care Management Education: Development of an Accelerated MBA and MPH Degree Program at Yale

    PubMed Central

    Forman, Howard P.; Pistell, Anne F.; Nembhard, Ingrid M.

    2015-01-01

    Increasingly, there is recognition of the need for individuals with expertise in both management and public health to help health care organizations deliver high-quality and cost-effective care. The Yale School of Public Health and Yale School of Management began offering an accelerated Master of Business Administration (MBA) and Master of Public Health (MPH) joint degree program in the summer of 2014. This new program enables students to earn MBA and MPH degrees simultaneously from 2 fully accredited schools in 22 months. Students will graduate with the knowledge and skills needed to become innovative leaders of health care organizations. We discuss the rationale for the program, the developmental process, the curriculum, benefits of the program, and potential challenges. PMID:25706023

  7. Predicting motorcyclists' intentions to speed: effects of selected cognitions from the theory of planned behaviour, self-identity and social identity.

    PubMed

    Elliott, Mark A

    2010-03-01

    This study sought to identify cognitive predictors of motorcyclists' intentions to speed using a model that comprised selected constructs from the theory of planned behaviour (TPB), supplemented with constructs from identity theory and social identity theory. Participants (N=110) were sampled from motorcycle clubs in Scotland and they completed web-based questionnaire measures of all cognitive variables, operationalized with respect to speeding on both 30 mph urban roads and 70 mph dual carriageways and motorways. In support of the TPB element of the model, affective attitude and perceived controllability accounted for significant variance in intention to speed on each road type. The identity constructs accounted for additional variance in intentions to speed on 70 mph roads. The significant independent predictors of speeding intentions on 30 mph roads were affective attitude and perceived controllability. For 70 mph roads, the independent predictors of intention were affective attitude, self-identity, perceived group norm, group identification, and an interaction between perceived group norm and group identification. Consistent with predictions derived from social identity theory, decomposition of the interaction showed that perceived group norm had an increasing effect on intention with increases in group identification. Implications for theory development and safety interventions are discussed.

  8. Human subject rear passenger symptom response to frontal car-to-car low-speed crash tests

    PubMed Central

    Croft, Arthur C.; Eldridge, T. Randall

    2011-01-01

    Objective The purpose of this study was to determine whether healthy adult volunteers report symptoms following exposure to low-speed frontal crashes at low velocities. Methods Nineteen medically screened, healthy, informed, and willing volunteers (17 men, 2 women; mean age, 37 years) were exposed to low-speed frontal crashes. All volunteers were seated in the rear seat position of the bullet vehicle. Closing velocities ranged from 4.1 to 8.3 mph (mean, 6.7 mph). For the bullet vehicle, the delta V ranged from 1.4 to 3.9 mph with a mean of 2.8 mph. Results Eighty-eight percent of volunteers attributed symptoms of discomfort to their crash exposure. All reported symptoms were transient, and none required medical treatment. The mean duration was 1 day. Conclusions Even at relatively low speeds, there is no lower threshold below which it can be reasonably assumed that healthy and prepared volunteer rear seat passengers will not sustain some level of minor injury in a frontal collision. Although the reported mean delta V for injured persons in real-world frontal crashes has been reported to be as high as 8.1 mph, this does not offer any insight into the minimum threshold for such injuries among all at-risk vehicle occupants. PMID:22014902

  9. Emergence of macrolide resistance gene mph(B) in Streptococcus uberis and cooperative effects with rdmC-like gene.

    PubMed

    Achard, Adeline; Guérin-Faublée, Véronique; Pichereau, Vianney; Villers, Corinne; Leclercq, Roland

    2008-08-01

    Streptococcus uberis UCN60 was resistant to spiramycin (MIC = 8 microg/ml) but susceptible to erythromycin (MIC = 0.06 microg/ml), azithromycin (MIC = 0.12 microg/ml), josamycin (MIC = 0.25 microg/ml), and tylosin (MIC = 0.5 microg/ml). A 2.5-kb HindIII fragment was cloned from S. uberis UCN60 DNA on plasmid pUC18 and introduced into Escherichia coli AG100A, where it conferred resistance to spiramycin by inactivation. The sequence analysis of the fragment showed the presence of an rdmC-like gene that putatively encoded a protein belonging to the alpha/beta hydrolase family and of the first 196 nucleotides of the mph(B) gene putatively encoding a phosphotransferase known to inactivate 14-, 15-, and 16-membered macrolides in E. coli. The entire mph(B) gene was then identified in S. uberis UCN60. The two genes were expressed alone or in combination in E. coli, Staphylococcus aureus, and Enterococcus faecalis. Analysis of MICs revealed that rdmC-like alone did not confer resistance to erythromycin, tylosin, and josamycin in those three hosts. It conferred resistance to spiramycin in E. coli and E. faecalis but not in S. aureus. mph(B) conferred resistance in E. coli to erythromycin, tylosin, josamycin, and spiramycin but only low levels of resistance in E. faecalis and S. aureus to spiramycin (MIC = 8 microg/ml). The combination of mph(B) and rdmC-like genes resulted in a resistance to spiramycin and tylosin in the three hosts that significantly exceeded the mere addition of the resistance levels conferred by each resistance mechanism alone.

  10. The Prevalence and Characteristics of Dual PharmD/MPH Programs Offered at US Colleges and Schools of Pharmacy

    PubMed Central

    Seed, Sheila; Borja-Hart, Nancy; Young, Veronica; Woodard, Lisa J.; Nobles-Knight, Dolores; Scott, David M.; Nash, James D.

    2013-01-01

    Objective. To assess the prevalence and characteristics of curriculum in dual doctor of pharmacy (PharmD)/master of public health (MPH) degree programs offered by US pharmacy programs. Methods. An 18-item survey instrument was developed and distributed online to faculty members at US colleges and schools of pharmacy. Results. Of the 110 colleges and schools that responded, 23 (21%) offered a PharmD/MPH degree. Common characteristics of these 23 programs included current PharmD program structure (3 + 1 year), early curricular recruitment, small enrollment, and interdisciplinary coursework occurring online and in the classroom. The impact of the dual degree on the curriculum and longevity of the dual-degree programs varied. About 55% of responding programs without a formal dual-degree program reported that additional public health training was available. Conclusion. Twenty-one percent of colleges and schools of pharmacy offer a combined PharmD/MPH dual degree. Most programs required an additional 1 or 2 semesters to complete both degrees. PMID:23966719

  11. The prevalence and characteristics of dual PharmD/MPH programs offered at US colleges and schools of pharmacy.

    PubMed

    Gortney, Justine S; Seed, Sheila; Borja-Hart, Nancy; Young, Veronica; Woodard, Lisa J; Nobles-Knight, Dolores; Scott, David M; Nash, James D

    2013-08-12

    To assess the prevalence and characteristics of curriculum in dual doctor of pharmacy (PharmD)/master of public health (MPH) degree programs offered by US pharmacy programs. An 18-item survey instrument was developed and distributed online to faculty members at US colleges and schools of pharmacy. Of the 110 colleges and schools that responded, 23 (21%) offered a PharmD/MPH degree. Common characteristics of these 23 programs included current PharmD program structure (3 + 1 year), early curricular recruitment, small enrollment, and interdisciplinary coursework occurring online and in the classroom. The impact of the dual degree on the curriculum and longevity of the dual-degree programs varied. About 55% of responding programs without a formal dual-degree program reported that additional public health training was available. Twenty-one percent of colleges and schools of pharmacy offer a combined PharmD/MPH dual degree. Most programs required an additional 1 or 2 semesters to complete both degrees.

  12. Pushbroom Stereo for High-Speed Navigation in Cluttered Environments

    DTIC Science & Technology

    2014-09-01

    second (fps) on a conventional CPU. Our system is lightweight and accurate The authors are with the Computer Science and Artificial Intellegence Laboratory...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Massachusetts Institute of Technology, Computer Science and Artificial Intellegence Laboratory,Cambridge,MA...high-speed, small UAV, flying at over 20 MPH (9 m/s) close to obstacles. The system requires no external sensing or computation and is, to the best of

  13. Deep Sub Micron 65nm Program- Perspectives for the Next Generation Satellites

    NASA Astrophysics Data System (ADS)

    Hili, Laurent; Dugoujon, Laurent; Roche, Phillippe; Malou, Florence; Perdu, Phillippe

    2012-08-01

    This paper presents the recent advances in terms of European digital microelectronics technologies for space applications. This article exemplifies the case of the Deep Sub-Micron 65nm program led by ESA and CNES in partnership with semiconductor industry, ST Microelectronics. Recent programs such as Inmarsat XL (Astrium) have exacerbated the limits of the current digital ASIC (Application Specific Integrated Circuit). Those limits have been reached in all areas; transistors/gates integration, speed, power and number of available IOs. The DSM 65nm program shows how those limits will be overcome thanks to breakthrough technologies such as high speed serial links (HSSL / 6.25Gbps), high pin count flip chip package technology (1600 pins).

  14. Experimental Investigation of Spark-Ignited Combustion with High-Octane Biofuels and EGR. 2. Fuel and EGR Effects on Knock-Limited Load and Speed

    SciTech Connect

    Splitter, Derek A; Szybist, James P

    2013-01-01

    The present study experimentally investigates spark-ignited combustion with 87 AKI E0 gasoline in its neat form and in midlevel alcohol gasoline blends with 24% vol/vol isobutanol gasoline (IB24) and 30% vol/vol ethanol gasoline (E30). A single-cylinder research engine is used with an 11.85:1 compression ratio, hydraulically actuated valves, laboratory intake air, and was capable of external exhaust gas recirculation (EGR). Experiments were conducted with all fuels to full-load conditions with = 1, using both 0% and 15% external-cooled EGR. Higher octane number biofuel blends exhibited increased stoichiometric torque capability at this compression ratio, where the unique properties of ethanol enabled a doubling of the stoichiometric torque capability with E30 as compared to that of 87AKI, up to 20 bar IMEPg (indicating mean effective pressure gross) at = 1. The results demonstrate that for all fuels, EGR is a key enabler for increasing engine efficiency but is less useful for knock mitigation with E30 than for 87AKI gasoline or IB24. Under knocking conditions, 15% EGR is found to offer 1 CA of CA50 timing advance with E30, whereas up to 5 CA of CA50 advance is possible with knock-limited 87AKI gasoline. Compared to 87AKI, both E30 and IB24 are found to have reduced adiabatic flame temperature and shorter combustion durations, which reduce knocking propensity beyond that indicated by the octane number. However, E30+0% EGR is found to exhibit the better antiknock properties than either 87AKI+15% EGR or IB24+15% EGR, expanding the knock limited operating range and engine stoichiometric torque capability at high compression ratio. Furthermore, the fuel sensitivity (S) of E30 was attributed to reduced speed sensitivity of E30, expanding the low-speed stoichiometric torque capability at high compression ratio. The results illustrate that intermediate alcohol gasoline blends exhibit exceptional antiknock properties and performance beyond that indicated by the octane

  15. STS 65 Final Report

    NASA Technical Reports Server (NTRS)

    Rice, James E.

    1996-01-01

    The report is organized into sections representing the phases of work performed in analyzing the STS 65 results and preparing the instrument for STS 73. Section 1 briefly outlines the Orbital Acceleration Research Experiment (OARE) system features, coordinates, and measurement parameters. Section 2 describes the results from STS 65. The mission description, data calibration, and representative data obtained on STS 65 are presented. Also, the anomalous performance of OARE on STS 65 is discussed. Finally, Section 3 presents a discussion of accuracy achieved and achievable with OARE.

  16. Speed of sound in periodic elastic composites

    NASA Astrophysics Data System (ADS)

    Krokhin, Arkady; Arriaga, Jesús; Gumen, Ludmila

    2003-03-01

    Using the method of homogenization^1 we calculate the effective speed of sound in periodic elastic structures (phononic crystals) in the low-frequency limit. We proof that in this limit a periodic medium behaves like a homogeneous one and derive analytical formulas for the speed of longitudinal sound in 3D mixtures of liquids and gases and for the speed of transversal waves in 2D phononic crystals. In the latter case the structure consists of infinite parallel rods arranged periodically in solid elastic medium. Our formulas are valid for arbitrary Bravais lattice, and form of inclusions. Unlike the phenomenological Wood's law for the elastic modulus of composites, our exact formula involves all the details of the microstructure of the periodic medium. We show that a periodic medium exhibits in general anisotropic acoustic properties, i.e. the speed of sound depends on the direction of propagation. We consider a particular case of air bubbles in water and calculate the speed of sound as a function of air fraction. The famous effect of the drop of speed of sound in mixtures is clearly seen and our data are in a good agreement with the data obtained in the coherent potential approximation.^2 ^1A.A. Krokhin, et al., Phys. Rev. B 65, 115208 (2002). ^2M. Kafesaki, et al., Phys. Rev. Lett. 84, 6050 (2000).

  17. The pulsed linear induction motor concept for high-speed trains

    SciTech Connect

    Turman, B.N.; Marder, B.M.; Rohwein, G.J.; Aeschliman, D.P.; Kelley, J.B.; Cowan, M.; Zimmerman, R.M.

    1995-06-01

    The SERAPBIM (SEgmented RAil PHased Induction Motor) concept is a linear induction motor concept which uses rapidly-pulsed magnetic fields and a segmented reaction rail, as opposed to low-frequency fields and continuous reaction rails found in conventional linear induction motors. These improvements give a high-traction, compact, and efficient linear motor that has potential for advanced high speed rail propulsion. In the SERAPBIM concept, coils on the vehicle push against a segmented aluminum rail, which is mounted on the road bed. Current is pulsed as the coils cross an edge of the segmented rail, inducing surface currents which repel the coil. The coils must be pulsed in synchronization with the movement by reaction rail segments. This is provided by a sense-and-fire circuit that controls the pulsing of the power modulators. Experiments were conducted to demonstrate the feasibility of the pulsed induction motor and to collect data that could be used for scaling calculations. A 14.4 kg aluminum plate was accelerated down a 4 m track to speeds of over 15 m/sec with peak thrust up to 18 kN per coilset. For a trainset capable of 200 mph speed, the SERAPHIM concept design is based on coils which are each capable of producing up to 3.5 kN thrust, and 30 coil pairs are mounted on each power car. Two power cars, one at each end of the train, provide 6 MW from two gas turbine prime power units. The thrust is about 210.000 N and is essentially constant up to 200 km/hr since wheel slippage does not limit thrust as with conventional wheeled propulsion. A key component of the SERAPHIM concept is the use of passive wheel-on-rah support for the high speed vehicle. Standard steel wheels are capable of handling over 200 mph. The SERAPHIM cost is comparable to that for steel-wheel high-speed rail, and about 10% to 25% of the projected costs for a comparable Maglev system.

  18. DAC 22 High Speed Civil Transport Model

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Between tests, NASA research engineer Dave Hahne inspects a tenth-scale model of a supersonic transport model in the 30- by 60-Foot Tunnel at NASA Langley Research Center, Hampton, Virginia. The model is being used in support of NASA's High-Speed Research (HSR) program. Langley researchers are applying advance aerodynamic design methods to develop a wing leading-edge flap system which significantly improves low-speed fuel efficiency and reduces noise generated during takeoff operation. Langley is NASA's lead center for the agency's HSR program, aimed at developing technology to help U.S. industry compete in the rapidly expanding trans-oceanic transport market. A U.S. high-speed civil transport is expected to fly in about the year 2010. As envisioned, it would fly 300 passengers across the Pacific in about four hours at Mach 2.4 (approximately 1,600 mph/1950 kph) for a modest increase over business class fares.

  19. THE EFFECTS OF A RECTANGULAR RAPID-FLASHING BEACON ON VEHICLE SPEED

    PubMed Central

    Van Wagner, Michelle; Van Houten, Ron; Betts, Brian

    2011-01-01

    In 2008, nearly 31% of vehicle fatalities were related to failure to adhere to safe vehicle speeds (National Highway Traffic Safety Administration [NHTSA], 2009). The current study evaluated the effect of a rectangular rapid-flashing beacon (RRFB) triggered by excessive speed on vehicle speed using a combined alternating treatments and reversal design. The percentage of vehicles traveling above 41 mph (66 km per hour) decreased by 20%, and speed distributions showed a shift toward lower speeds during the RRFB condition. PMID:21941395

  20. MPH1, a yeast gene encoding a DEAH protein, plays a role in protection of the genome from spontaneous and chemically induced damage.

    PubMed Central

    Scheller, J; Schürer, A; Rudolph, C; Hettwer, S; Kramer, W

    2000-01-01

    We have characterized the MPH1 gene from Saccharomyces cerevisiae. mph1 mutants display a spontaneous mutator phenotype. Homologs were found in archaea and in the EST libraries of Drosophila, mouse, and man. Mph1 carries the signature motifs of the DEAH family of helicases. Selected motifs were shown to be necessary for MPH1 function by introducing missense mutations. Possible indirect effects on translation and splicing were excluded by demonstrating nuclear localization of the protein and splicing proficiency of the mutant. A mutation spectrum did not show any conspicuous deviations from wild type except for an underrepresentation of frameshift mutations. The mutator phenotype was dependent on REV3 and RAD6. The mutant was sensitive to MMS, EMS, 4-NQO, and camptothecin, but not to UV light and X rays. Epistasis analyses were carried out with representative mutants from various repair pathways (msh6, mag1, apn1, rad14, rad52, rad6, mms2, and rev3). No epistatic interactions were found, either for the spontaneous mutator phenotype or for MMS, EMS, and 4-NQO sensitivity. mph1 slightly increased the UV sensitivity of mms2, rad6, and rad14 mutants, but no effect on X-ray sensitivity was observed. These data suggest that MPH1 is not part of a hitherto known repair pathway. Possible functions are discussed. PMID:10880470

  1. Vehicle speed control device

    SciTech Connect

    Thornton-Trump, W.E.

    1987-03-10

    An apparatus is described for automatically limiting the speed of a vehicle powered by an internal combustion engine having a spark ignition system with an ignition coil, comprising: sensor means for generating a speed signal directly representative of the speed of the vehicle comprising a series of speed signal pulses having a pulse repetition frequency proportional to the speed of the vehicle; control means for converting speed signal pulses into a DC voltage proportional to the vehicle speed; means for comparing the DC voltage to a predetermined DC voltage having substantially zero AC components representative of a predetermined maximum speed and for generating a difference signal in response thereto; and means for generating a pulse-width modulated control signal responsive to the difference signal; power means responsive to the control signal for intermittently interrupting the ignition system.

  2. 40 CFR 65.49-65.59 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false 65.49-65.59 Section 65.49-65.59 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Storage Vessels §§ 65.49-65.59...

  3. 40 CFR 65.15-65.19 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false 65.15-65.19 Section 65.15-65.19 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions §§ 65.15-65.19 ...

  4. 14 CFR 65.46-65.46b - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false 65.46-65.46b Section 65.46-65.46b Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Air Traffic Control Tower Operators §§ 65.46-65.46b ...

  5. 14 CFR 65.46-65.46b - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false 65.46-65.46b Section 65.46-65.46b Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Air Traffic Control Tower Operators §§ 65.46-65.46b ...

  6. 14 CFR 65.46-65.46b - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false 65.46-65.46b Section 65.46-65.46b Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Air Traffic Control Tower Operators §§ 65.46-65.46b ...

  7. 14 CFR 65.46-65.46b - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false 65.46-65.46b Section 65.46-65.46b Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Air Traffic Control Tower Operators §§ 65.46-65.46b ...

  8. 14 CFR 65.46-65.46b - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false 65.46-65.46b Section 65.46-65.46b Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Air Traffic Control Tower Operators §§ 65.46-65.46b ...

  9. Aggregate nonparametric safety analysis of traffic zones.

    PubMed

    Siddiqui, Chowdhury; Abdel-Aty, Mohamed; Huang, Helai

    2012-03-01

    Exploring the significant variables related to specific types of crashes is vitally important in the planning stage of a transportation network. This paper aims to identify and examine important variables associated with total crashes and severe crashes per traffic analysis zone (TAZ) in four counties of the state of Florida by applying nonparametric statistical techniques such as data mining and random forest. The intention of investigating these factors in such aggregate level analysis is to incorporate proactive safety measures in transportation planning. Total and severe crashes per TAZ were modeled to provide predictive decision trees. The variables which carried higher weight of importance for total crashes per TAZ were - total number of intersections per TAZ, airport trip productions, light truck productions, and total roadway segment length with 35 mph posted speed limit. The other significant variables identified for total crashes were total roadway length with 15 mph posted speed limit, total roadway length with 65 mph posted speed limit, and non-home based work productions. For severe crashes, total number of intersections per TAZ, light truck productions, total roadway length with 35 mph posted speed limit, and total roadway length with 65 mph posted speed limit were among the significant variables. These variables were further verified and supported by the random forest results.

  10. STEM@1000mph: Developing Open Educational Resources in a Live Engineering Project

    ERIC Educational Resources Information Center

    Lanham, John; Howard, Yvonne; Drew, Ben; Johns, Dan

    2013-01-01

    Higher education institutions are recognising the clear benefits of open educational resources, and academics are engaging with the development of these resources. This paper presents a case study of OERs being developed using the live, current BloodhoundSSC world land speed record project as a basis. The paper outlines the rationale for the…

  11. Leadership training for radiologists: a survey of opportunities and participants in MBA and MPH programs by medical students, residents, and current chairpersons.

    PubMed

    Baker, Stephen; Daginawala, Naznin

    2011-08-01

    The aim of this study was to determine opportunities for students and trainees to obtain an MPH or MBA degree during either medical school or radiology residency and to determine the prevalence of such degree possession by chairpersons in radiology. All allopathic medical schools in the United States were surveyed to chart the number of MD/MPH and MD/MBA degree programs available to students. Program directors were contacted to assess the number of MPH or MBA courses of study administratively related to their residencies. Also, an e-mail survey was sent to all members of the Society of Chairs of Academic Radiology Departments inquiring whether each chairperson had earned an additional degree. Currently, 81 allopathic medical schools in the United States offer MD/MPH degrees, and 52 offer MD/MBA degrees. Six residencies provide access to MPH programs, and 3 residencies provide the opportunity to pursue an MBA in conjunction with residency. Of these, only 1 MPH program and no MBA programs had trainees enrolled at present. Twenty-six percent of the chairpersons surveyed possessed advanced degrees other than MDs. There has been rapid growth in the number of MD/MPH and MD/MBA programs available to medical students. However, there is a scarcity of similar programs accessible to trainees during or just after residency training. To assist motivated radiologists interested in leading our profession, opportunities should expand both in formal degree-granting programs and through certificate-sanctioned course series to address relevant issues of leadership and management pertinent to our specialty. Copyright © 2011 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  12. 40 CFR 65.105 - Leak repair.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... pump that meets the requirements of § 65.107(e)(2) will be installed; or (C) A system that routes.... First attempt at repair for pumps includes, but is not limited to, tightening the packing gland nuts and... destroyed or recovered in a control device complying with § 65.115. (4) Delay of repair for pumps is...

  13. Monitoring speed before and during a speed publicity campaign.

    PubMed

    van Schagen, Ingrid; Commandeur, Jacques J F; Goldenbeld, Charles; Stipdonk, Henk

    2016-12-01

    Driving speeds were monitored during a period of 16 weeks encompassing different stages of an anti-speeding campaign in the Netherlands. This campaign targeted speed limit violations in built-up areas. The observation periods differed in terms of intensity and media used for the campaign. Small road-side radars, mounted in light poles, were used and registered the speeds on 20 locations in built-up areas. Speeds of over 10 million vehicles were measured. Ten locations had a posted speed limit of 50km/h; the other ten had a posted speed limit of 30km/h. Posters were placed at half of each group of locations to remind drivers of the speed limit. The average speed on the 50km/h roads was 46.2km/h, and 36.1km/h on the 30km/h roads. The average proportions of vehicles exceeding the speed limit were 33.3% and 70.1% respectively. For the 30km/h roads, the data shows differences in speed and speeding behaviour between the six distinguished observation periods, but overall these differences cannot be logically linked to the contents of the phases and, hence, cannot be explained as an effect of the campaign. The only exception was an effect of local speed limit reminders on the 30km/h roads. This effect, however, was temporary and had disappeared within a week.

  14. Do speed cameras reduce speeding in urban areas?

    PubMed

    Oliveira, Daniele Falci de; Friche, Amélia Augusta de Lima; Costa, Dário Alves da Silva; Mingoti, Sueli Aparecida; Caiaffa, Waleska Teixeira

    2015-11-01

    This observational study aimed to estimate the prevalence of speeding on urban roadways and to analyze associated factors. The sample consisted of 8,565 vehicles circulating in areas with and without fixed speed cameras in operation. We found that 40% of vehicles 200 meters after the fixed cameras and 33.6% of vehicles observed on roadways without speed cameras were moving over the speed limit (p < 0.001). Motorcycles showed the highest recorded speed (126km/h). Most drivers were men (87.6%), 3.3% of all drivers were using their cell phones, and 74.6% of drivers (not counting motorcyclists) were wearing their seatbelts. On roadway stretches without fixed speed cameras, more women drivers were talking on their cell phones and wearing seatbelts when compared to men (p < 0.05 for both comparisons), independently of speed limits. The results suggest that compliance with speed limits requires more than structural interventions.

  15. Speed governor for diesel engine

    SciTech Connect

    Kadyshevich, Y.K.; Miselev, M.A.; Svistunov, N.N.

    1985-01-01

    A speed governor was developed for the 12ChSN 18/20 ship diesel engine to reduce emission of fumes and eliminate transient overloads, with pneumatic correction of the fuel injection rate according to the supercharge pressure. The device includes an electric corrector, and a hydraulic amplifier with slide valve. It is found that the regulator improves the performance, including torque and combustion characteristics and reduces the emission level to 15% within 2 s and decreases only to a 65% level. It was also tested on a Kometa hydrofoil ship with regulation of the diesel start over an 80 to 90 s acceleration period independently of the crank turning time, and maintained overloads and fume emission within prescribed limits.

  16. A Diffraction-limited Survey for Direct Detection of Halpha Emitting/Accreting ExtraSolar Planets with the 6.5m Magellan Telescope and the MagAO Visible AO system

    NASA Astrophysics Data System (ADS)

    Close, Laird

    TECHNICAL BACKGROUND: An advanced adaptive secondary mirror (ASM) with 585 actuators was commissioned at the 6.5-m Magellan Telescope at one of the world’s best sites (Las Campanas Observatory; LCO) in Chile. By the end of the commissioning run (April 2013) the MagAO system was regularly producing the highest spatial resolution deep images to date (0.023” deep images at Halpha (0.656 microns); Close et al. 2013). This is due to its 378 corrective modes at 1kHz on a 6.5-m telescope. Strehl ratis>20% at Halpha were obtained in 75% of the seeing statistics at the site. We propose here to utilize MagAO’s absolutely unique ability to take Halpha, continuum (0.643 microns), and L’ (3.8 microns) thermal images (all simultaneously) to carry out a novel survey to: Discover a population of the lowest mass young accreting extrasolar planets imaged to date. to characterize the spatial distribution, and estimate accretion rates, of young extrasolar planets >5AU, to understand the influence of planets on transitional disk gaps. THEORY BACKGROUND: Extrasolar planets are very difficult to image directly since planets become very faint below ~8 Mjup (Jupiter masses) for ages >1 Myr and such massive planets are rare. There is a class of young stars that are still accreting yet have SED (and often imaging) evidence of a lack of dust and gas inside a r=5-140 AU “gap”. These “transitional disks” are believed to be transitioning into “disk free” stars. These gaps are believed to be maintained by planets that continuously clear (though scattering or accretion) the optically thin gaps. Indeed large >10 AU gaps (>few Hill spheres) must be maintained by multiple ~1 Mjup planets (Dodson-Robinson & Salyk 2011). Since gas must pass through each of these gaps to continuously supply the accreting star, simulations suggest that these “gap planets” are also crossing points for these gas streamers on their way to the star. These streamers “force-feed” these planets a

  17. Binding of the Fkh1 Forkhead Associated Domain to a Phosphopeptide within the Mph1 DNA Helicase Regulates Mating-Type Switching in Budding Yeast

    PubMed Central

    Su, Zhangli; Cherney, Rachel; Choi, Koyi; Denu, John; Zhao, Xiaolan; Fox, Catherine A.

    2016-01-01

    The Saccharomyces cerevisiae Fkh1 protein has roles in cell-cycle regulated transcription as well as a transcription-independent role in recombination donor preference during mating-type switching. The conserved FHA domain of Fkh1 regulates donor preference by juxtaposing two distant regions on chromosome III to promote their recombination. A model posits that this Fkh1-mediated long-range chromosomal juxtaposition requires an interaction between the FHA domain and a partner protein(s), but to date no relevant partner has been described. In this study, we used structural modeling, 2-hybrid assays, and mutational analyses to show that the predicted phosphothreonine-binding FHA domain of Fkh1 interacted with multiple partner proteins. The Fkh1 FHA domain was important for its role in cell-cycle regulation, but no single interaction partner could account for this role. In contrast, Fkh1’s interaction with the Mph1 DNA repair helicase regulated donor preference during mating-type switching. Using 2-hybrid assays, co-immunoprecipitation, and fluorescence anisotropy, we mapped a discrete peptide within the regulatory Mph1 C-terminus required for this interaction and identified two threonines that were particularly important. In vitro binding experiments indicated that at least one of these threonines had to be phosphorylated for efficient Fkh1 binding. Substitution of these two threonines with alanines (mph1-2TA) specifically abolished the Fkh1-Mph1 interaction in vivo and altered donor preference during mating-type switching to the same degree as mph1Δ. Notably, the mph1-2TA allele maintained other functions of Mph1 in genome stability. Deletion of a second Fkh1-interacting protein encoded by YMR144W also resulted in a change in Fkh1-FHA-dependent donor preference. We have named this gene FDO1 for Forkhead one interacting protein involved in donor preference. We conclude that a phosphothreonine-mediated protein-protein interface between Fkh1-FHA and Mph1 contributes

  18. Wind Speed and Moisture Sensitivity Tests of the NRL Limited Area Dynamical Weather Prediction Model: An OSSE Study of ERICA IOP 4

    DTIC Science & Technology

    1992-03-01

    the Special Sensor Microwave/ Imager . Assimilating this modeled satellite information into the degraded version of the model shows ERICA IOP-4 to be a...iv A. COMPARISONS OF SSM/I IMAGES AND 16 LAYER MODEL OUTPUT ........ .................... 32 1. Satellite Data ..... ............... 32 2. Wind Speed...wind field (m/s) at 2400 UTC ........ .................... .. 40 Figure 15. SSM/I water vapor image at 0000 UTC. Contours depict precipitable water

  19. 30 CFR 18.65 - Flame test of hose.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.65 Flame... variable-speed electric fan and an ASME flow nozzle (16-81/2 inches reduction) to attain constant air velocities at any speed between 50-500 feet a minute. (4) An electric timer or stopwatch to measure...

  20. Speed Variance and Its Influence on Accidents.

    ERIC Educational Resources Information Center

    Garber, Nicholas J.; Gadirau, Ravi

    A study was conducted to investigate the traffic engineering factors that influence speed variance and to determine to what extent speed variance affects accident rates. Detailed analyses were carried out to relate speed variance with posted speed limit, design speeds, and other traffic variables. The major factor identified was the difference…

  1. Dielectric barrier discharge actuator for vehicle drag reduction at highway speeds

    NASA Astrophysics Data System (ADS)

    Roy, Subrata; Zhao, Pengfei; DasGupta, Arnob; Soni, Jignesh

    2016-02-01

    We propose and demonstrate reduction of aerodynamic drag for a realistic geometry at highway speeds using serpentine dielectric barrier discharge actuators. A comparable linear plasma actuator fails to reduce the drag at these speeds. Experimental data collected for linear and serpentine plasma actuators under quiescent operating conditions show that the serpentine design has profound effect on near wall flow structure and resulting drag. For certain actuator arrangement, the measured drag reduced by over 14% at 26.8 m/s (60 mph) and over 10% at 31.3 m/s (70 mph) opening up realistic possibility of reasonable energy savings for full scale ground vehicles. In addition, the power consumption data and drag reduction effectiveness for different input signals are also presented.

  2. A comparison of academic curricula in the MPH and MHA-type degrees in health administration at the accredited schools of public health.

    PubMed

    Singh, D A; Stoskope, C H; Ciesla, J R

    1996-01-01

    Based on a survey of the departments of health services administration in accredited schools of public health, this study presents (1) a profile of the M.P.H. and M.H.A. (and similar) programs concentrating in health administration, and (2) a comparison of the M.P.H. and M.H.A. degrees. All 27 schools currently accredited by the Council on Education for Public Health (CEPH) are represented in this research. The curriculum from each school was broken down and classified into eight components: (1) epidemiology, (2) statistics, (3) accounting/finance, (4) management theory, (5) management application, (6) public health policy, (7) electives, and (8) other. That the M.H.A. programs compared to the M.P.H. programs, have higher course requirements to furnish skills in business management and quantitative/analytical areas is the main hypothesis tested. Statistically significant differences were found in seven of the eight curriculum components for M.P.H. and M.H.A. degrees. Overall, the M.H.A. degree was found to be more rigorous in applied management and analytical courses. Implications and recommendations are discussed.

  3. Neurotrophin 3 genotype and emotional adverse effects of osmotic-release oral system methylphenidate (OROS-MPH) in children with attention-deficit/hyperactivity disorder.

    PubMed

    Park, Subin; Kim, Bung-Nyun; Kim, Jae-Won; Shin, Min-Sup; Cho, Soo-Churl; Kim, Ji-Hoon; Son, Jung-Woo; Shin, Yun-Mi; Chung, Un-Sun; Han, Doug-Hyun

    2014-03-01

    Neurotrophin 3 (NTF3) has been studied in relation to the pathophysiology of attention-deficit/hyperactivity disorder (ADHD) and mood disorders as well as psychostimulant action. We hypothesized that the risk of an emotional side effect to methylphenidate (MPH) treatment may be associated with NTF3 genotypes. Ninety-six medication-naïve children with ADHD (mean age 8.70, standard deviation 1.41 years, 79 males) were genotyped and treated with MPH. At baseline, which was prior to MPH treatment, and after two weeks of medication, investigators asked children and their parents or caregivers about adverse events using a symptom rating scale. ADHD subjects with the A/A genotype at the NTF3 rs6332 polymorphism showed the highest 'Emotionality' and 'Over-focus/euphoria' factor scores, followed by those with the G/A genotype and those with the G/G genotype (p=0.042 and p=0.045, respectively). ADHD subjects with the A/A genotype at the NTF3 rs6332 polymorphism showed the highest 'Proneness to crying' and 'Nail biting' item scores, followed by those with the G/A genotype and those with the G/G genotype (p=0.047 and p=0.017, respectively). These data provide preliminary evidence that genetic variation in the NTF3 gene is related to susceptibility to emotional side effects in response to MPH treatment in Korean children with ADHD.

  4. [The utility of a continuous performance test embedded in virtual reality in measuring the effectiveness of MPH treatment in boys with ADHD].

    PubMed

    Shriki, Liron; Weizer, Merav; Pollak, Yehuda; Weiss, Patricia L; Rizzo, Albert A; Gross-Tsur, Varda

    2010-01-01

    Continuous performance tasks (CPT) are popular in the diagnostic process of attention deficit hyperactivity disorder (ADHD), providing an objective measure of attention for a disorder with otherwise subjective criteria. The study aimed to: 1) examine whether the VR-CPT is sensitive to methylphenidate (MPH); 2) assess how the virtual reality (VR) environment is experienced. Twenty boys, 9-17 years, with ADHD underwent 3 CPTs: VR-CPT, the same CPT without VR (no VR-CPT) and the Test of Variables of Attention (T.O.V.A.). Subsequently, those with ADHD repeated the tests 1 hour following MPH ingestion. Immediately following the CPT, the subjects described their subjective experiences on the Short Feedback Questionnaire. Results were analyzed using ANOVA with repeated measures. MPH reduced the omission and commission errors on all tests to a similar degree. Subjective feelings of enjoyment were most positive for VR-CPT. The VR-CPT is a sensitive and user-friendly assessment tool for evaluating the effectiveness of MPH treatment in boys with ADHD.

  5. Redefining the Speed Limit of Phase Change Memory Revealed by Time-resolved Steep Threshold-Switching Dynamics of AgInSbTe Devices

    PubMed Central

    Shukla, Krishna Dayal; Saxena, Nishant; Durai, Suresh; Manivannan, Anbarasu

    2016-01-01

    Although phase-change memory (PCM) offers promising features for a ‘universal memory’ owing to high-speed and non-volatility, achieving fast electrical switching remains a key challenge. In this work, a correlation between the rate of applied voltage and the dynamics of threshold-switching is investigated at picosecond-timescale. A distinct characteristic feature of enabling a rapid threshold-switching at a critical voltage known as the threshold voltage as validated by an instantaneous response of steep current rise from an amorphous off to on state is achieved within 250 picoseconds and this is followed by a slower current rise leading to crystallization. Also, we demonstrate that the extraordinary nature of threshold-switching dynamics in AgInSbTe cells is independent to the rate of applied voltage unlike other chalcogenide-based phase change materials exhibiting the voltage dependent transient switching characteristics. Furthermore, numerical solutions of time-dependent conduction process validate the experimental results, which reveal the electronic nature of threshold-switching. These findings of steep threshold-switching of ‘sub-50 ps delay time’, opens up a new way for achieving high-speed non-volatile memory for mainstream computing. PMID:27886266

  6. Redefining the Speed Limit of Phase Change Memory Revealed by Time-resolved Steep Threshold-Switching Dynamics of AgInSbTe Devices

    NASA Astrophysics Data System (ADS)

    Shukla, Krishna Dayal; Saxena, Nishant; Durai, Suresh; Manivannan, Anbarasu

    2016-11-01

    Although phase-change memory (PCM) offers promising features for a ‘universal memory’ owing to high-speed and non-volatility, achieving fast electrical switching remains a key challenge. In this work, a correlation between the rate of applied voltage and the dynamics of threshold-switching is investigated at picosecond-timescale. A distinct characteristic feature of enabling a rapid threshold-switching at a critical voltage known as the threshold voltage as validated by an instantaneous response of steep current rise from an amorphous off to on state is achieved within 250 picoseconds and this is followed by a slower current rise leading to crystallization. Also, we demonstrate that the extraordinary nature of threshold-switching dynamics in AgInSbTe cells is independent to the rate of applied voltage unlike other chalcogenide-based phase change materials exhibiting the voltage dependent transient switching characteristics. Furthermore, numerical solutions of time-dependent conduction process validate the experimental results, which reveal the electronic nature of threshold-switching. These findings of steep threshold-switching of ‘sub-50 ps delay time’, opens up a new way for achieving high-speed non-volatile memory for mainstream computing.

  7. Elf for electronic linear flow control of variable speed ground ULV applications.

    PubMed

    Dame, D A; Curtis, G A

    1990-06-01

    The Elf device delivered the appropriate ground ULV rate at variable road speeds ranging from 4 to 21 mph (6 to 32 kph), and shut off automatically at higher and lower speeds. The system is designed to be compatible with vehicles equipped with digital as well as standard speedometers and can be calibrated at any speed within its operating range. Although not used in these studies, Elf has a distance calibration feature designed to enhance the accuracy of the transducer and thus to yield greater flow precision than could be achieved with the transducer alone.

  8. Steady-state bioavailability of extended-release methylphenidate (MPH-MLR) capsule vs. immediate-release methylphenidate tablets in healthy adult volunteers.

    PubMed

    Adjei, Akwete; Kupper, Robert J; Teuscher, Nathan S; Wigal, Sharon; Sallee, Floyd; Childress, Ann; Kollins, Scott H; Greenhill, Laurence

    2014-11-01

    The objective of the study was to determine the relative bioavailability of an extended-release multilayer bead formulation of methylphenidate hydrochloride (MPH-MLR) 80 mg vs. methylphenidate immediate-release (IR; Ritalin(®)) tablets as single and multiple doses in the fed state. A single-center, multiple-dose, randomized, open-label, two-period crossover study conducted in 26 healthy adults assigned to 4 days of once-daily MPH-MLR 80 mg or IR methylphenidate 25 mg three times daily. MPH-MLR 80 mg produced reproducible biphasic profiles of plasma methylphenidate concentrations characterized by a rapid initial peak, followed by a moderate decline reaching a plateau ~5 h post dose, then a gradual increase culminating in an attenuated second peak ~7 h post dose. Maximum concentration was lower for MPH-MLR 80 mg than IR methylphenidate 25 mg three times daily on day 1 (23.70 vs. 31.47 ng/mL); exposure was similar. The geometric mean ratios (MPH-MLR/IR methylphenidate [90 % CI]) of log-transformed area under the plasma drug concentration-time curve to the last measurable observation (day 1: 0.88 [84.75-91.80]; day 4: 0.84 [81.16-86.94]), and area under the plasma drug concentration extrapolated to infinity (day 1: 0.93 [88.57-97.28]; day 4: 0.88 [84.48-91.17]) were within the 80-125 % bioequivalence range. The mean ± SD MPH-MLR 80-mg capsule day 4 area under the plasma drug concentration vs. time curve from 0 to 4 h (74.5 ± 15.2 ng·h/mL) was greater than IR methylphenidate 25 mg three times daily (66.0 ± 17.4 ng·h/mL), confirming steady-state levels during the study period. All treatment regimens were safe and well tolerated. MPH-MLR 80-mg capsule once daily or IR methylphenidate 25 mg three times daily provides comparable maximum methylphenidate concentrations and systemic exposure in the fed state.

  9. Reduced sensitivity to visual looming inflates the risk posed by speeding vehicles when children try to cross the road.

    PubMed

    Wann, John P; Poulter, Damian R; Purcell, Catherine

    2011-04-01

    Almost all locomotor animals respond to visual looming or to discrete changes in optical size. The need to detect and process looming remains critically important for humans in everyday life. Road traffic statistics confirm that children up to 15 years old are overrepresented in pedestrian casualties. We demonstrate that, for a given pedestrian crossing time, vehicles traveling faster loom less than slower vehicles, which creates a dangerous illusion in which faster vehicles may be perceived as not approaching. Our results from perceptual tests of looming thresholds show strong developmental trends in sensitivity, such that children may not be able to detect vehicles approaching at speeds in excess of 20 mph. This creates a risk of injudicious road crossing in urban settings when traffic speeds are higher than 20 mph. The risk is exacerbated because vehicles moving faster than this speed are more likely to result in pedestrian fatalities.

  10. Shaft speed control

    NASA Technical Reports Server (NTRS)

    Ford, A. G.

    1979-01-01

    Simple mechanism controls rotation of heavy-duty shaft by mechanical comparison with rotation of small, precise, stepper motor. Mechanism can be used to limit winding and unwinding speeds of large spools and reels and to control speed of other rotating shafts. Setup incorporates reference shaft geared down from stepper motor and feedback shaft geared up from shaft to be controlled. Feedback and reference shafts are coupled with brake assembly inside stationary cylinder. When work shaft speeds up, brakes are activated automatically to slow it down.

  11. KSC-99pc65

    NASA Image and Video Library

    1999-01-14

    KENNEDY SPACE CENTER, FLA. -- A pintail duck swims calmly in the waters of the Merritt Island National Wildlife Refuge, which shares a boundary with the space center. The pintail can be found in marshes, prairie ponds and tundra, and salt marshes in winter. They range from Alaska and Greenland south to Central America and the West Indies. The open waters of the Wildlife Refuge provide wintering areas for 23 species of migratory waterfowl as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds. The refuge comprises 92,000 acres, ranging from fresh-water impoundments, salt-water estuaries and brackish marshes to hardwood hammocks and pine flatwoods. The diverse landscape provides habitat for more than 310 species of birds, 25 mammals, 117 fishes, and 65 amphibians and reptiles, including such endangered species as Southern bald eagles, wood storks, Florida scrub jays, Atlantic loggerhead and leatherback turtles, osprey, and nearly 5,000 alligators

  12. S65-29730

    NASA Image and Video Library

    1965-06-08

    S65-29730 (3 June 1965) --- Astronaut Edward H. White II, pilot for the Gemini-Titan 4 (GT-4) spaceflight, floats in the zero-gravity of space during the third revolution of the GT-4 spacecraft. White wears a specially designed spacesuit. His face is shaded by a gold-plated visor to protect him from unfiltered rays of the sun. In his right hand he carries a Hand-Held Self-Maneuvering Unit (HHSMU) that gives him control over his movements in space. White also wears an emergency oxygen chest pack; and he carries a camera mounted on the HHSMU for taking pictures of the sky, Earth and the GT-4 spacecraft. He is secured to the spacecraft by a 25-feet umbilical line and a 23-feet tether line. Both lines are wrapped together in gold tape to form one cord. Astronaut James A. McDivitt, command pilot, remained inside the spacecraft during the extravehicular activity (EVA). Photo credit: NASA EDITOR'S NOTE: Astronaut Edward H. White II died in the Apollo/Saturn 204 fire at Cape Kennedy on Jan. 27, 1967.

  13. STS-65 Onboard Photograph

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronaut Chiaki Mukai conducts the Lower Body Negative Pressure (LBNP) experiment inside the International Microgravity Laboratory-2 (IML-2) mission science module. Dr. Chiaki Mukai is one of the National Space Development Agency of Japan (NASDA) astronauts chosen by NASA as a payload specialist (PS). She was the second NASDA PS who flew aboard the Space Shuttle, and was the first female astronaut in Asia. When humans go into space, the lack of gravity causes many changes in the body. One change is that fluids normally kept in the lower body by gravity shift upward to the head and chest. This is why astronauts' faces appear chubby or puffy. The change in fluid volume also affects the heart. The reduced fluid volume means that there is less blood to circulate through the body. Crewmembers may experience reduced blood flow to the brain when returning to Earth. This leads to fainting or near-fainting episodes. With the use of the LBNP to simulate the pull of gravity in conjunction with fluids, salt tablets can recondition the cardiovascular system. This treatment, called 'soak,' is effective up to 24 hours. The LBNP uses a three-layer collapsible cylinder that seals around the crewmember's waist which simulates the effects of gravity and helps pull fluids into the lower body. The data collected will be analyzed to determine physiological changes in the crewmembers and effectiveness of the treatment. The IML-2 was the second in a series of Spacelab flights designed by the international science community to conduct research in a microgravity environment Managed by the Marshall Space Flight Center, the IML-2 was launched on July 8, 1994 aboard the STS-65 Space Shuttle Orbiter Columbia mission.

  14. STS-65 Onboard Photograph

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronaut Chiaki Mukai conducts the Lower Body Negative Pressure (LBNP) experiment inside the International Microgravity Laboratory-2 (IML-2) mission science module. Dr. Chiaki Mukai is one of the National Space Development Agency of Japan (NASDA) astronauts chosen by NASA as a payload specialist (PS). She was the second NASDA PS who flew aboard the Space Shuttle, and was the first female astronaut in Asia. When humans go into space, the lack of gravity causes many changes in the body. One change is that fluids normally kept in the lower body by gravity shift upward to the head and chest. This is why astronauts' faces appear chubby or puffy. The change in fluid volume also affects the heart. The reduced fluid volume means that there is less blood to circulate through the body. Crewmembers may experience reduced blood flow to the brain when returning to Earth. This leads to fainting or near-fainting episodes. With the use of the LBNP to simulate the pull of gravity in conjunction with fluids, salt tablets can recondition the cardiovascular system. This treatment, called 'soak,' is effective up to 24 hours. The LBNP uses a three-layer collapsible cylinder that seals around the crewmember's waist which simulates the effects of gravity and helps pull fluids into the lower body. The data collected will be analyzed to determine physiological changes in the crewmembers and effectiveness of the treatment. The IML-2 was the second in a series of Spacelab flights designed by the international science community to conduct research in a microgravity environment Managed by the Marshall Space Flight Center, the IML-2 was launched on July 8, 1994 aboard the STS-65 Space Shuttle Orbiter Columbia mission.

  15. FS65 Disposition Option Report

    SciTech Connect

    Wenz, Tracy R.

    2015-09-25

    This report outlines the options for dispositioning the MOX fuel stored in FS65 containers at LANL. Additional discussion regarding the support equipment for loading and unloading the FS65 transport containers is included at the end of the report.

  16. Performance of Compressor of XJ-41-V Turbojet Engine II - Static-Pressure Ratios and Limitation of Maximum Flow at Equivalent Compressor Speed of 8000 rpm

    NASA Technical Reports Server (NTRS)

    Dildine, Dean M.; Arthur, W. Lewis

    1948-01-01

    At the request of the Air Material Command, Army Air Forces, an investigation was conducted by the NACA Cleveland laboratory to determine the performance characteristics of the compressor of the XJ-41-V turbojet engine. This report is the second in a series presenting the compressor performance and analysis of flow conditions in the compressor. The static-pressure variation in the direction of flow through the compressor and the location and the cause of the maximum flow restriction at an equivalent speed of 8000 rpm are presented. After the initial runs were reported, the leading edges of the impeller blades and the diffuser surfaces were found to have been roughened by steel particles from a minor failure of auxiliary equipment. The leading edges of the impeller blades were refinished and all high spots resulting from scratches in the diffuser and the accessible parts of the vaned collector passages were removed. The initial overall performance and that obtained with the refinished blades are presented.

  17. The DNP/MPH Dual Degree: An Innovative Graduate Education Program for Advanced Public Health Nursing.

    PubMed

    Shaw, Kathy; Harpin, Scott; Steinke, Geraldine; Stember, Marilyn; Krajicek, Marilyn

    2017-03-01

    Strong professional priorities, evolving Affordable Care Act requirements, and a significantly limited public health nursing workforce prompted the University of Colorado College of Nursing to collaborate with the School of Public Health to implement one of the first Doctor of Nursing Practice/Master of Public Health dual degree programs in the nation. Federal grant funding supported the development, implementation, and evaluation of this unique post-baccalaureate dual degree program, for which there were no roadmaps, models, or best practices to follow. Several key issues emerged that serve as lessons learned in creating a new, novel higher education pathway for Advanced Public Health Nursing. This paper highlights two of those: (1) marketing, admission, and matriculation across two programs, and (2) enhancing curricula through distance coursework and interprofessional education. When collaboration with a school of public health is possible, the Doctor of Nursing Practice/Master of Public Health dual degree is an efficient way to prepare public health nurses' with the highest level of public health knowledge, practice, and leadership expertise.

  18. 8-Foot High Speed Tunnel

    NASA Technical Reports Server (NTRS)

    1936-01-01

    Control panel below the test section of the 8-Foot High Speed Tunnel (8-Foot HST). Authorized July 17, 1933, construction of the 8-Foot HST was paid for with funds from the Federal Public Works Administration. Manly Hood and Russell Robinson designed the unusual facility which could produce a 500 mph wind stream across an 8-Foot test section. The concrete shell was not part of the original design. Like most projects funded through New Deal programs, the PWA restricted the amount of money which could be spent on materials. The majority of funds were supposed to be expended on labor. Though originally, Hood and Robinson had planned a welded steel pressure vessel around the test section, PWA officials proposed the idea of concrete. This picture shows the test section inside the igloo-like structure with walls of 1-foot thick reinforced concrete. The thick walls were needed 'because of the Bernoulli effect, [which meant that] the text chamber had to withstand powerful, inwardly directed pressure. Operating personnel located inside the igloo were subjected to pressures equivalent to 10,000-foot altitude and had to wear oxygen masks and enter through airlocks. A heat exchanger removed the large quantities of heat generated by the big fan.'

  19. Thermal stress imposed by prototype bilayer and current ground crew chemical defense ensembles: a limited laboratory comparison. Final report, 30 June 1986-1 January 1987

    SciTech Connect

    Krock, L.P.; Navalta, R.; Myhre, L.G.

    1988-07-01

    An open bilayer ground-crew chemical defense ensemble (CDE) was proposed to reduce the thermal burden during vapor-only exposure periods. This study compared the thermal-stress profile of the proposed ensemble to that produced by the currently employed closed CDE. Four subjects, alternating ensembles on separate days, walked on a treadmill in an environmental chamber at 5.3 km/h (3.3 mph) and 2% grade (an energy expenditure of 350 kcal/h) for alternating work/rest to achieve significant recovery. Mean total sweat production was lower (1.38 vs. 2.50 liters) and percent sweat evaporation greater (65.7% vs. 30.0%) in the prototype ensemble than in the CDE. The prototype ensemble provided greater heat dissipation and allowed more-efficient sweat evaporation which had the double benefit of reducing heat storage and limiting dehydration.

  20. Integrating service-learning into an MPH curriculum for future public health practitioners: strengthening community-campus partnerships.

    PubMed

    Anderson, Lisa S; Royster, Michael O; Bailey, Nannette; Reed, Karen

    2011-01-01

    Through a 3-year grant from the Community-Campus Partnerships for Health, the Virginia Commonwealth University MPH program adopted an incremental approach to implement service-learning focused on health disparities into its curriculum. We first incorporated service-learning into an elective course and then a required internship. We then worked with the Virginia Department of Health to develop a plan for first-year students to engage in additional experiential learning through a practicum. Students also were encouraged to organize community service events, such as health fairs. Service-learning was fully incorporated into the internship. The first-year student practicum, followed by the internship, has strengthened collaborations among faculty, students, and the Virginia Department of Health and expanded student service in the community. The number of student-supported community service events more than doubled. An incremental approach to incorporating service-learning led to successful implementation of the pedagogy. Service-learning benefits community partners, enriches student learning, and is well-suited for studies in public health.