Sample records for left turn phase

  1. Guidelines for the use of protected/permissive left-turn phasing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Agent, K.R.

    1987-07-01

    Turning left across opposing traffic at a signalized intersection could result in a traffic accident, as well as create motorist delay. A solution to the left-turn problem may be the addition of a left-turn phase when certain guidelines are met. After a decision has been made to add a left-turn phase, one of two basic alternative phasing methods is . In a previous research study, the results of replacing protected-only (exclusive) with protected/permissive (permissive) phasing at four trial intersections were studied. The permissive phasing provided a substantial reduction in delay and was popular with local drivers. However, several left-turn relatedmore » accidents occurred at those locations. Since those initial trial installations, permissive phasing has been used at several intersections across the state. This created a larger data base that could be used to determine when permissive phasing could be used without causing an accident problem. The objective of this study was to develop guidelines to aid traffic engineers in deciding whether permissive left-turn phasing is appropriate for use at a given location.« less

  2. Left-turn phase: permissive, protected, or both? A quasi-experimental design in New York City.

    PubMed

    Chen, Li; Chen, Cynthia; Ewing, Reid

    2015-03-01

    The practice of left-turn phasing selection (permissive, protected-only, or both) varies from one locality to another. The literature evidence on this issue is equally mixed and insufficient. In this study, we evaluate the safety impacts of changing left-turn signal phasing from permissive to protected/permissive or protected-only at 68 intersections in New York City using a rigorous quasi-experimental design accompanied with regression modeling. Changes in police reported crashes including total crashes, multiple-vehicle crashes, left-turn crashes, pedestrian crashes and bicyclist crashes were compared between before period and after period for the treatment group and comparison group by means of negative binomial regression using a Generalized Estimating Equations (GEE) technique. Confounding factors such as the built environment characteristics that were not controlled in comparison group selection are accounted for by this approach. The results show that the change of permissive left-turn signal phasing to protected/permissive or protected-only signal phasing does not result in a significant reduction in intersection crashes. Though the protected-only signal phasing does reduce the left-turn crashes and pedestrian crashes, this reduction was offset by a possible increase in over-taking crashes. These results suggest that left-turn phasing should not be treated as a universal solution that is always better than the permissive control for left-turn vehicles. The selection and implementation of left-turn signal phasing needs to be done carefully, considering potential trade-offs between safety and delay, and many other factors such as geometry, traffic flows and operations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Development of guidelines for permitted left-turn phasing using flashing yellow arrows : final report.

    DOT National Transportation Integrated Search

    2015-06-01

    The objective of this project was to develop guidelines for time-of-day use of permitted left-turn phasing, : which can then be implemented using flashing yellow arrows (FYA). This required determining how the risk : for left-turn crashes varied as t...

  4. Deciding alternative left turn signal phases using expert systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chang, E.C.P.

    1988-01-01

    The Texas Transportation Institute (TTI) conducted a study to investigate the feasibility of applying artificial intelligence (AI) technology and expert systems (ES) design concepts to a traffic engineering problem. Prototype systems were developed to analyze user input, evaluate various reasoning, and suggest suitable left turn phase treatment. These systems were developed using AI programming tools on IBM PC/XT/AT-compatible microcomputers. Two slightly different systems were designed using AI languages; another was built with a knowledge engineering tool. These systems include the PD PROLOG and TURBO PROLOG AI programs, as well as the INSIGHT Production Rule Language.

  5. Left-Turn Bays

    DOT National Transportation Integrated Search

    1996-05-01

    The topic of left-turn bays (left-turn lanes) involves the following three issues: 1.) Warrants; 2.) Bay Length and 3.) Design Details. This discussion paper deals with warrants and bay length -- including queue storage at signalized and unsignalized...

  6. Development of pedestrian safety based warrants for permissive left-turn control

    DOT National Transportation Integrated Search

    2010-12-01

    At the intersections with permissive only signal control, pedestrians will move at the permissive phase with the parallel through vehicular movement and left-turn vehicles, the left-turn vehicles have to yield to both opposing through vehicles and pe...

  7. Modeling left-turn crash occurrence at signalized intersections by conflicting patterns.

    PubMed

    Wang, Xuesong; Abdel-Aty, Mohamed

    2008-01-01

    In order to better understand the underlying crash mechanisms, left-turn crashes occurring at 197 four-legged signalized intersections over 6 years were classified into nine patterns based on vehicle maneuvers and then were assigned to intersection approaches. Crash frequency of each pattern was modeled at the approach level by mainly using Generalized Estimating Equations (GEE) with the Negative Binomial as the link function to account for the correlation among the crash data. GEE with a binomial logit link function was also applied for patterns with fewer crashes. The Cumulative Residuals test shows that, for correlated left-turn crashes, GEE models usually outperformed basic Negative Binomial models. The estimation results show that there are obvious differences in the factors that cause the occurrence of different left-turn collision patterns. For example, for each pattern, the traffic flows to which the colliding vehicles belong are identified to be significant. The width of the crossing distance (represented by the number of through lanes on the opposing approach of the left-turning traffic) is associated with more left-turn traffic colliding with opposing through traffic (Pattern 5), but with less left-turning traffic colliding with near-side crossing through traffic (Pattern 8). The safety effectiveness of the left-turning signal is not consistent for different crash patterns; "protected" phasing is correlated with fewer Pattern 5 crashes, but with more Pattern 8 crashes. The study indicates that in order to develop efficient countermeasures for left-turn crashes and improve safety at signalized intersections, left-turn crashes should be considered in different patterns.

  8. Dynamic flashing yellow arrow (FYA) : a study on variable left turn model operational and safety impacts, [technical summary].

    DOT National Transportation Integrated Search

    2013-12-01

    Traffic engineers use various left-turn signalization : methods to find an optimal balance of safety and : efficiency. While protected/permitted left-turn : configurations allow most left-turning traffic to : turn during the protected phase, the perm...

  9. Dynamic flashing yellow arrow (FYA): a study on variable left-turn mode operational and safety impacts phase II - model expansion and testing.

    DOT National Transportation Integrated Search

    2016-06-01

    The flashing yellow arrow (FYA) signal display creates an opportunity to enhance the left-turn phase with a : variable mode that can be changed on demand. The previously developed decision support system (DSS) in : phase I facilitated the selection o...

  10. Operational evaluation of right turns followed by U-turns as an alternative to direct left turns, Vol. 3

    DOT National Transportation Integrated Search

    2001-09-01

    This project evaluated the safety and operational impacts of two alternative left-turn treatments from driveways/side streets. The two treatments were: (1) Direct left turns (DLT) and, (2) Right turns followed by U-turns (RTUT). Ten sites were select...

  11. Safety evaluation of right turns followed by U-turns as an alternative to direct left turns : conflict analysis, Vol. 2

    DOT National Transportation Integrated Search

    2001-10-01

    This project evaluated the safety and operational impacts of two alternative left-turn treatments from driveways/side streets. The two treatments were (1) direct left turns and (2) right turns followed by U-turns. Safety analyses of the alternatives ...

  12. Dynamic flashing yellow arrow (FYA): a study on variable left-turn mode operational and safety impacts phase II - model expansion and testing : [summary].

    DOT National Transportation Integrated Search

    2016-05-01

    In phase two of this project, the UCF team further developed the DSS to automate selection of FYA left-turn modes based on traffic volumes at intersections acquired in real time from existing sensors.

  13. Safety evaluation of right turns followed by U-turns as an alternative to direct left turns : crash data analysis, Vol. 1

    DOT National Transportation Integrated Search

    2001-10-01

    This project evaluated the safety and operational impacts of two alternative left-turn treatments from driveway/side streets. The two treatments were: (1) direct left turns and, (2) right turns followed by U-turns. Safety analyses of the alternatives...

  14. Guidelines for the use of no U-turn and no left-turn signs.

    DOT National Transportation Integrated Search

    1994-01-01

    The objective of this study was to establish a set of written guidelines identifying traffic and road conditions where No U-Turn and No Left Turn signs should be installed. The effect of these signs on traffic safety was also investigated. A question...

  15. Displaced left turn intersection : informational guide.

    DOT National Transportation Integrated Search

    2014-08-01

    This document provides information and guidance on the Displaced Left Turn (DLT) intersection. To the extent possible, the : guide addresses a variety of conditions found in the United States, to achieve designs suitable for a wide array of potential...

  16. Development of guidelines for triple left and dual right-turn lanes : technical report.

    DOT National Transportation Integrated Search

    2011-07-01

    Left- or right-turn lanes at intersections improve safety and operations by separating turning and through vehicles. At intersections : with heavy turning demand, it may be necessary to provide multiple turn lanes. Triple left-turn (TLT) and dual rig...

  17. Childrens' left-turning preference is not modulated by magical ideation.

    PubMed

    Streuli, Jürg C; Obrist, Gina; Brugger, Peter

    2017-01-01

    The literature on human turning preferences is inconsistent. While the few studies with children below 14 years of age uniformly describe an overall left-turning (counterclockwise) tendency, a recent Internet study with more than 1500 adults found a right-sided (clockwise) bias. We set out to investigate spontaneous turning behaviour in children age 5-3 years and, based on neuropsychiatric work in adults, also explored a potential association with magical thinking. Findings indicated a clear left-turning preference, independent of a participant's sex and handedness. Whether a child responded a question about the existence of extrasensory communication in the affirmative or not was unrelated to direction and size of turning bias and lateral preference. Our results are consistent with a left-sided turning preference reported for children, but in opposition to the clockwise bias recently described in a large-scale study with adults. Whether they point to a maturational gradient in the preferred direction of spontaneous whole-body rotation or rather to a lack of comparability between measures used in observational versus Internet-based studies remains to be further investigated. Regarding a purported association between body turns and magical thinking, our study is preliminary, as only one single question was used to probe the latter.

  18. Thunderstorm-scale variations of echoes associated with left-turn tornado families

    NASA Technical Reports Server (NTRS)

    Forbes, G. S.

    1977-01-01

    The origin of tornadoes is studied on the basis of changing radar echo shapes and tornado location relative to the echoes. Three types of tornadoes appear to be associated with different hook echo configurations. No-turn or right-turn tornadoes are linked to a steady hook which does not change shape or orientation. Left-turn tornado families are generated in cases where the hook is unsteady and changes orientation at each successive tornado birth. Finally, left-turn tornado families may also be formed when the hook undergoes no orientation change and the tornadoes move along the rear of the hook. The correlation between a thunderstorm-scale cycle and periodic tornado production is also discussed.

  19. Evaluation of Revised Left Turn Signalization : Final Report

    DOT National Transportation Integrated Search

    1997-11-01

    Modified left turn signals had shown cost savings over the old style of traffic signals in initial installation and maintenance. This evaluation was conducted to determine whether those savings would be justified by no increase in the accident rates ...

  20. Influence of bus stop with left-turn lines between two adjacent signalized intersections

    NASA Astrophysics Data System (ADS)

    Pang, Ming-Bao; Ye, Lan-Hang; Pei, Ya-Nan

    2016-08-01

    Based on the symmetric two-lane Nagel-Schreckenberg (STNS) model, a three-lane cellular automaton model between two intersections containing a bus stop with left-turning buses is established in which model the occurrences of vehicle accidents are taken into account. The characteristics of traffic flows with different ratios of left-turn lines are discussed via the simulation experiments. The results indicate that the left-turn lines have more negative effects on capacity, accident rate as well as delay if the stop is located close to the intersections, where the negative effect in a near-side stop is more severe than that in a far-side one. The range of appropriate position for a bus stop without the bottleneck effect becomes more and more narrow with the increase of the ratio of left-turn bus lines. When the inflow is small, a short signal cycle and a reasonable offset are beneficial. When the inflow reaches or exceeds the capacity, a longer signal cycle is helpful. But if the stop position is inappropriate, the increase of cycle fails in reducing the negative effect of left-turning buses and the effectiveness of offset is weakened. Project supported by the National Natural Science Foundation of China (Grant No. 50478088) and the Natural Science Foundation of Hebei Province, China (Grant No. E2015202266).

  1. Safety effects of traffic signing for left turn flashing yellow arrow signals.

    PubMed

    Schattler, Kerrie L; Gulla, Cody J; Wallenfang, Travis J; Burdett, Beau A; Lund, Jessica A

    2015-02-01

    In 2010, the left turn flashing yellow arrow (FYA) signal displays were installed at signalized intersections on state routes in the Peoria, Illinois, area. Supplemental traffic signs with text "Left Turn Yield on Flashing Yellow Arrow" were mounted on the mast arm adjacent to the left turn signal at over half of the FYA installations. The purpose of this paper is to present the results of the effectiveness evaluation of the FYA supplemental sign on safety. Analyses are presented on the effects of the FYA supplemental sign for all drivers and a subset of drivers age 65 and older. A crash-based comparison of 164 FYA approaches including 90 approaches with the sign and 74 approaches without the sign showed greater crash reductions when the supplemental FYA sign was present. The results also showed that crashes involving drivers age 65 and older did not experience the same magnitudes of crash reductions as compared to all drivers. The findings of this research indicate that supplemental FYA signs may help in improving safety for left-turning vehicles during the permissive interval. Thus, it is recommended that supplemental signs be used when initially implementing the FYA, and that effort to educate the driving public on new traffic control be made to further improve safety at signalized intersections. Copyright © 2014. Published by Elsevier Ltd.

  2. Bicyclists' inclination and ability to search behind before turning left

    DOT National Transportation Integrated Search

    1980-02-01

    Author's abstract: Research (Cross and Fisher, 1977) has identified a relatively high incidence (8.4%) bicycle/motor-vehicle accident type in which a bicyclist initiates a left-hand turn without searching to the rear or signaling and is struck by an ...

  3. Dynamic flashing yellow arrow (FYA) : a study on variable left turn mode operational and safety impacts.

    DOT National Transportation Integrated Search

    2013-12-01

    Accommodating left turns at signalized intersections has been a challenge for traffic engineers as they : seek balance between two conflicting goals; capacity and safety. The use of a four-section head for the left-turn : lane only with a flashing ye...

  4. Tune Evaluation From Phased BPM Turn-By-Turn Data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Alexahin, Y.; Gianfelice-Wendt, E.; Marsh, W.

    2010-05-18

    In fast ramping synchrotrons like the Fermilab Booster the conventional methods of betatron tune evaluation from the turn-by-turn data may not work due to rapid changes of the tunes (sometimes in a course of a few dozens of turns) and a high level of noise. We propose a technique based on phasing of signals from a large number of BPMs which significantly increases the signal to noise ratio. Implementation of the method in the Fermilab Booster control system is described and some measurement results are presented.

  5. Design criteria for median turn lanes.

    DOT National Transportation Integrated Search

    1978-03-01

    This study was initiated with an extensive literature review and survey of : left-turn median lane practices in Texas cities. The initial phase identified : characteristics of urban arterial accidents, basic design elements, current use of : left-tur...

  6. Development of left-turn lane guidelines for signalized and unsignalized intersections.

    DOT National Transportation Integrated Search

    2004-01-01

    It is generally accepted that the level of service (LOS) at intersections significantly affects the overall LOS of the road system. It is also known that the LOS at an intersection can be adversely affected by frequently allowing left-turning vehicle...

  7. Safety evaluation of intersections with dynamic use of exit-lanes for left-turn using field data.

    PubMed

    Zhao, Jing; Liu, Yue

    2017-05-01

    As a newly proposed unconventional intersection design, the exit-lanes for left-turn (EFL) intersection is found to be effective in increasing the intersection capacity with high level of application flexibility, especially under heavy left-turn traffic conditions. However, the operational safety of EFL is of most concern to the authority prior to its implementation. This paper evaluates the safety of the EFL intersections by studying the behavior of left-turn maneuvers using field data collected at 7 locations in China. A total of 22830 left-turn vehicles were captured, in which 9793 vehicles turned left using the mixed-usage area. Four potential safety problems, including the red-light violations, head-on collision risks, trapped vehicles, and rear-end crash risks, were discussed. Statistical analyses were carried out to compare the safety risk between the EFL intersection and the conventional one. Results indicate that the safety problems of EFL intersections mainly lie in higher percentages in red-light violations at the pre-signal (1.83% higher), wrong-way violation problems during the peak hours (the violation rate reaches up to 11.07%), and the lower travel speeds in the mixed-usage area (18.75% lower). Such risks can be counteracted, however, by providing more guiding information, installing cameras to investigate and punish violation maneuvers, and adjusting design parameter values for layout design and signal timing, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. State-of-the-art literature review on permissive/protected left-turn control.

    DOT National Transportation Integrated Search

    2013-06-01

    In spring 2010, the Illinois Department of Transportation initiated an areawide implementation to integrate the : flashing yellow arrow as the display for the left-turn permissive interval at more than 100 intersections operating : with protected/per...

  9. No turning, a mouse mutation causing left-right and axial patterning defects.

    PubMed

    Melloy, P G; Ewart, J L; Cohen, M F; Desmond, M E; Kuehn, M R; Lo, C W

    1998-01-01

    Patterning along the left/right axes helps establish the orientation of visceral organ asymmetries, a process which is of fundamental importance to the viability of an organism. A linkage between left/right and axial patterning is indicated by the finding that a number of genes involved in left/right patterning also play a role in anteroposterior and dorsoventral patterning. We have recovered a spontaneous mouse mutation causing left/right patterning defects together with defects in anteroposterior and dorsoventral patterning. This mutation is recessive lethal and was named no turning (nt) because the mutant embryos fail to undergo embryonic turning. nt embryos exhibit cranial neural tube closure defects and malformed somites and are caudally truncated. Development of the heart arrests at the looped heart tube stage, with cardiovascular defects indicated by ballooning of the pericardial sac and the pooling of blood in various regions of the embryo. Interestingly, in nt embryos, the direction of heart looping was randomized. Nodal and lefty, two genes that are normally expressed only in the left lateral plate mesoderm, show expression in the right and left lateral plate mesoderm. Lefty, which is normally also expressed in the floorplate, is not found in the prospective floor plate of nt embryos. This suggests the possibility of notochordal defects. This was confirmed by histological analysis and the examination of sonic hedgehog, Brachyury, and HNF-3 beta gene expression. These studies showed that the notochord is present in the early nt embryo, but degenerates as development progresses. Overall, these findings support the hypothesis that the notochord plays an active role in left/right patterning. Our results suggest that nt may participate in this process by modulating the notochordal expression of HNF-3 beta.

  10. Mirrors in the PDB: left-handed alpha-turns guide design with D-amino acids.

    PubMed

    Annavarapu, Srinivas; Nanda, Vikas

    2009-09-22

    Incorporating variable amino acid stereochemistry in molecular design has the potential to improve existing protein stability and create new topologies inaccessible to homochiral molecules. The Protein Data Bank has been a reliable, rich source of information on molecular interactions and their role in protein stability and structure. D-amino acids rarely occur naturally, making it difficult to infer general rules for how they would be tolerated in proteins through an analysis of existing protein structures. However, protein elements containing short left-handed turns and helices turn out to contain useful information. Molecular mechanisms used in proteins to stabilize left-handed elements by L-amino acids are structurally enantiomeric to potential synthetic strategies for stabilizing right-handed elements with D-amino acids. Propensities for amino acids to occur in contiguous alpha(L) helices correlate with published thermodynamic scales for incorporation of D-amino acids into alpha(R) helices. Two backbone rules for terminating a left-handed helix are found: an alpha(R) conformation is disfavored at the amino terminus, and a beta(R) conformation is disfavored at the carboxy terminus. Helix capping sidechain-backbone interactions are found which are unique to alpha(L) helices including an elevated propensity for L-Asn, and L-Thr at the amino terminus and L-Gln, L-Thr and L-Ser at the carboxy terminus. By examining left-handed alpha-turns containing L-amino acids, new interaction motifs for incorporating D-amino acids into right-handed alpha-helices are identified. These will provide a basis for de novo design of novel heterochiral protein folds.

  11. Mirrors in the PDB: left-handed α-turns guide design with D-amino acids

    PubMed Central

    Annavarapu, Srinivas; Nanda, Vikas

    2009-01-01

    Background Incorporating variable amino acid stereochemistry in molecular design has the potential to improve existing protein stability and create new topologies inaccessible to homochiral molecules. The Protein Data Bank has been a reliable, rich source of information on molecular interactions and their role in protein stability and structure. D-amino acids rarely occur naturally, making it difficult to infer general rules for how they would be tolerated in proteins through an analysis of existing protein structures. However, protein elements containing short left-handed turns and helices turn out to contain useful information. Molecular mechanisms used in proteins to stabilize left-handed elements by L-amino acids are structurally enantiomeric to potential synthetic strategies for stabilizing right-handed elements with D-amino acids. Results Propensities for amino acids to occur in contiguous αL helices correlate with published thermodynamic scales for incorporation of D-amino acids into αR helices. Two backbone rules for terminating a left-handed helix are found: an αR conformation is disfavored at the amino terminus, and a βR conformation is disfavored at the carboxy terminus. Helix capping sidechain-backbone interactions are found which are unique to αL helices including an elevated propensity for L-Asn, and L-Thr at the amino terminus and L-Gln, L-Thr and L-Ser at the carboxy terminus. Conclusion By examining left-handed α-turns containing L-amino acids, new interaction motifs for incorporating D-amino acids into right-handed α-helices are identified. These will provide a basis for de novo design of novel heterochiral protein folds. PMID:19772623

  12. Driving simulator evaluation of drivers' response to intersections with dynamic use of exit-lanes for left-turn.

    PubMed

    Zhao, Jing; Yun, Meiping; Zhang, H Michael; Yang, Xiaoguang

    2015-08-01

    With the worsening of urban traffic congestion in large cities around the world, researchers have been looking for unconventional designs and/or controls to squeeze more capacity out of intersections, the most common bottlenecks of the road network. One of these innovative intersection designs, known as the exit-lanes for left-turn (EFL), opens up exit-lanes to be used by left-turn traffic with the help of an additional traffic light installed at the median opening (the pre-signal). This paper studies how drivers respond to EFL intersections with a series of driving simulator experiments. In our experiments, 64 drivers were recruited and divided into two groups. One group is trained to use the EFL while the other group is not. In addition, four scenarios were considered with different sign and marking designs and traffic conditions in the experiments. Results indicate that drivers show certain amount of confusion and hesitation when encountering an EFL intersection for the first time. They can be overcome, however, by increasing exposure through driver education or by cue provided from other vehicles. Moreover, drivers unfamiliar with EFL operation can make a left turn using the conventional left-turn lanes as usual. The EFL operation is not likely to pose any serious safety risk of the intersection in real life operations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Evaluation of a Risk Awareness Perception Training Program on Novice Teen Driver Behavior at Left-Turn Intersections.

    PubMed

    McDonald, Catherine C; Kandadai, Venk; Loeb, Helen; Seacrist, Thomas; Lee, Yi-Ching; Bonfiglio, Dana; Fisher, Donald L; Winston, Flaura K

    Collisions at left turn intersections are among the most prevalent types of teen driver serious crashes, with inadequate surveillance as a key factor. Risk awareness perception training (RAPT) has shown effectiveness in improving hazard anticipation for latent hazards. The goal of this study was to determine if RAPT version 3 (RAPT-3) improved intersection turning behaviors among novice teen drivers when the hazards were not latent and frequent glancing to multiple locations at the intersection was needed. Teens aged 16-18 with ≤180 days of licensure were randomly assigned to: 1) an intervention group (n=18) that received RAPT-3 (Trained); or 2) a control group (n=19) that received no training (Untrained). Both groups completed RAPT-3 Baseline Assessment and the Trained group completed RAPT-3 Training and RAPT-3 Post Assessment. Training effects were evaluated on a driving simulator. Simulator ( gap selection errors and collisions ) and eye tracker ( traffic check errors) metrics from six left-turn stop sign controlled intersections in the Simulated Driving Assessment (SDA) were analyzed. The Trained group scored significantly higher in RAPT-3 Post Assessment than RAPT-3 Baseline Assessment (p< 0.0001). There were no significant differences in either traffic check and gap selection errors or collisions among Trained and Untrained teens in the SDA. Though Trained teens learned about hazard anticipation related to latent hazards, learning did not translate to performance differences in left-turn stop sign controlled intersections where the hazards were not latent. Our findings point to further research to better understand the challenges teens have with left turn intersections.

  14. Safety implications of the use of the flashing yellow arrow for permissive left turns.

    DOT National Transportation Integrated Search

    2011-01-01

    The use of the flashing yellow arrow (FYA) for permissive left turns is relatively new to California, with at least five : installations approved under a 2006 Federal Highway Administration (FHWA) Interim Approval memorandum. : Inclusion of formal gu...

  15. AUGMENTED REALITY CUES TO ASSIST OLDER DRIVERS WITH GAP ESTIMATION FOR LEFT-TURNS

    PubMed Central

    Rusch, Michelle L.; Schall, Mark C.; Lee, John D.; Dawson, Jeffrey D.; Rizzo, Matthew

    2014-01-01

    The objective of this study was to assess the effects of augmented reality (AR) cues designed to assist middle-aged and older drivers with a range of UFOV impairments, judging when to make left-turns across oncoming traffic. Previous studies have shown that AR cues can help middle-aged and older drivers respond to potential roadside hazards by increasing hazard detection without interfering with other driving tasks. Intersections pose a critical challenge for cognitively impaired drivers, prone to misjudge time-to-contact with oncoming traffic. We investigated whether AR cues improve or interfere with hazard perception in left-turns across oncoming traffic for drivers with age-related cognitive decline. Sixty-four middle-aged and older drivers with a range of UFOV impairment judged when it would be safe to turn left across oncoming traffic approaching the driver from the opposite direction in a rural stop-sign controlled intersection scenario implemented in a static base driving simulator. Outcome measures used to evaluate the effectiveness of AR cueing included: Time-to-Contact (TTC), Gap Time Variation (GTV), Response Rate, and Gap Response Variation (GRV). All drivers estimated TTCs were shorter in cued than in uncued conditions. In addition, drivers responded more often in cued conditions than in uncued conditions and GRV decreased for all drivers in scenarios that contained AR cues. For both TTC and response rate, drivers also appeared to adjust their behavior to be consistent with the cues, especially drivers with the poorest UFOV scores (matching their behavior to be close to middle-aged drivers). Driver ratings indicated that cueing was not considered to be distracting. Further, various conditions of reliability (e.g., 15% miss rate) did not appear to affect performance or driver ratings. PMID:24950128

  16. Augmented reality cues to assist older drivers with gap estimation for left-turns.

    PubMed

    Rusch, Michelle L; Schall, Mark C; Lee, John D; Dawson, Jeffrey D; Rizzo, Matthew

    2014-10-01

    The objective of this study was to assess the effects of augmented reality (AR) cues designed to assist middle-aged and older drivers with a range of UFOV impairments, judging when to make left-turns across oncoming traffic. Previous studies have shown that AR cues can help middle-aged and older drivers respond to potential roadside hazards by increasing hazard detection without interfering with other driving tasks. Intersections pose a critical challenge for cognitively impaired drivers, prone to misjudge time-to-contact with oncoming traffic. We investigated whether AR cues improve or interfere with hazard perception in left-turns across oncoming traffic for drivers with age-related cognitive decline. Sixty-four middle-aged and older drivers with a range of UFOV impairment judged when it would be safe to turn left across oncoming traffic approaching the driver from the opposite direction in a rural stop-sign controlled intersection scenario implemented in a static base driving simulator. Outcome measures used to evaluate the effectiveness of AR cueing included: Time-to-Contact (TTC), Gap Time Variation (GTV), Response Rate, and Gap Response Variation (GRV). All drivers estimated TTCs were shorter in cued than in uncued conditions. In addition, drivers responded more often in cued conditions than in uncued conditions and GRV decreased for all drivers in scenarios that contained AR cues. For both TTC and response rate, drivers also appeared to adjust their behavior to be consistent with the cues, especially drivers with the poorest UFOV scores (matching their behavior to be close to middle-aged drivers). Driver ratings indicated that cueing was not considered to be distracting. Further, various conditions of reliability (e.g., 15% miss rate) did not appear to affect performance or driver ratings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Improved simulation of driver behavior : modeling protected and permitted left-turn operations at signalized intersections.

    DOT National Transportation Integrated Search

    2011-04-01

    "This report documents the findings from a research project that is focused on modeling protected and permitted left-turn operations at signalized intersection approaches. The projects primary objective is to document the microscopic characteristi...

  18. A Field and Simulator Evaluation of All-Red Clearance Intervals for Use in Left-Turn Applications

    DOT National Transportation Integrated Search

    2018-03-01

    As the implementation of the novel flashing yellow arrow (FYA) traffic control device advances throughout the country, agencies continually seek ways to improve intersection operations and safety, especially on left turns. For example, permissive lef...

  19. Effects of major-road vehicle speed and driver age and gender on left-turn gap acceptance.

    PubMed

    Yan, Xuedong; Radwan, Essam; Guo, Dahai

    2007-07-01

    Because the driver's gap-acceptance maneuver is a complex and risky driving behavior, it is a highly concerned topic for traffic safety and operation. Previous studies have mainly focused on the driver's gap acceptance decision itself but did not pay attention to the maneuver process and driving behaviors. Using a driving simulator experiment for left-turn gap acceptance at a stop-controlled intersection, this study evaluated the effects of major traffic speed and driver age and gender on gap acceptance behaviors. The experiment results illustrate relationships among drivers' left-turn gap decision, driver's acceleration rate, steering action, and the influence of the gap-acceptance maneuver on the vehicles in the major traffic stream. The experiment results identified an association between high crash risk and high traffic speed at stop-controlled intersections. The older drivers, especially older female drivers, displayed a conservative driving attitude as a compensation for reduced driving ability, but also showed to be the most vulnerable group for the relatively complex driving maneuvers.

  20. Use of Flashing Yellow Operations to Improve Safety at Signals with Protected-Permissive Left Turn (PPLT) Operations

    DOT National Transportation Integrated Search

    2012-10-01

    MUTCD 2009 Edition suggests the use of Flashing Yellow Arrow (FYA) indication in replacement of green ball indication for permissive left-turn signal in presence of separate signal heads. Currently, there is no clear guidance on how to implement flas...

  1. Use of flashing yellow operations to improve safety at signals with protected-permissive left turn (PPLT) operations

    DOT National Transportation Integrated Search

    2012-10-01

    MUTCD 2009 Edition suggests the use of Flashing Yellow Arrow (FYA) indication in replacement of green ball indication for permissive left-turn signal in presence of separate signal heads. Currently, there is no clear guidance on how to implement flas...

  2. Left-handed helical preference in an achiral peptide chain is induced by an L-amino acid in an N-terminal type II β-turn.

    PubMed

    De Poli, Matteo; De Zotti, Marta; Raftery, James; Aguilar, Juan A; Morris, Gareth A; Clayden, Jonathan

    2013-03-15

    Oligomers of the achiral amino acid Aib adopt helical conformations in which the screw-sense may be controlled by a single N-terminal residue. Using crystallographic and NMR techniques, we show that the left- or right-handed sense of helical induction arises from the nature of the β-turn at the N terminus: the tertiary amino acid L-Val induces a left-handed type II β-turn in both the solid state and in solution, while the corresponding quaternary amino acid L-α-methylvaline induces a right-handed type III β-turn.

  3. Phase Retrieval System for Assessing Diamond Turning and Optical Surface Defects

    NASA Technical Reports Server (NTRS)

    Dean, Bruce; Maldonado, Alex; Bolcar, Matthew

    2011-01-01

    An optical design is presented for a measurement system used to assess the impact of surface errors originating from diamond turning artifacts. Diamond turning artifacts are common by-products of optical surface shaping using the diamond turning process (a diamond-tipped cutting tool used in a lathe configuration). Assessing and evaluating the errors imparted by diamond turning (including other surface errors attributed to optical manufacturing techniques) can be problematic and generally requires the use of an optical interferometer. Commercial interferometers can be expensive when compared to the simple optical setup developed here, which is used in combination with an image-based sensing technique (phase retrieval). Phase retrieval is a general term used in optics to describe the estimation of optical imperfections or aberrations. This turnkey system uses only image-based data and has minimal hardware requirements. The system is straightforward to set up, easy to align, and can provide nanometer accuracy on the measurement of optical surface defects.

  4. Modeling the frequency of opposing left-turn conflicts at signalized intersections using generalized linear regression models.

    PubMed

    Zhang, Xin; Liu, Pan; Chen, Yuguang; Bai, Lu; Wang, Wei

    2014-01-01

    The primary objective of this study was to identify whether the frequency of traffic conflicts at signalized intersections can be modeled. The opposing left-turn conflicts were selected for the development of conflict predictive models. Using data collected at 30 approaches at 20 signalized intersections, the underlying distributions of the conflicts under different traffic conditions were examined. Different conflict-predictive models were developed to relate the frequency of opposing left-turn conflicts to various explanatory variables. The models considered include a linear regression model, a negative binomial model, and separate models developed for four traffic scenarios. The prediction performance of different models was compared. The frequency of traffic conflicts follows a negative binominal distribution. The linear regression model is not appropriate for the conflict frequency data. In addition, drivers behaved differently under different traffic conditions. Accordingly, the effects of conflicting traffic volumes on conflict frequency vary across different traffic conditions. The occurrences of traffic conflicts at signalized intersections can be modeled using generalized linear regression models. The use of conflict predictive models has potential to expand the uses of surrogate safety measures in safety estimation and evaluation.

  5. Bolivia’s Left Turn Toward Rentier Plurinationalism And Its Effects On Ethnic Tensions And Solidarity

    DTIC Science & Technology

    2016-06-01

    utilities and gas pipelines sparked a broad societal solidarity movement against transnational corporate control of water and gas . The 2000 Water Wars...Constitution referendum, funds for social programs were to be allocated exclusively from hydrocarbon and natural gas rents. A. BOLIVIA’S LEFT TURN...Cartographies,” 991–992. 4 sector toward nationalization. The Bolivian energy sector, “natural gas , in particular” has “become the backbone of the

  6. Use of Flashing Yellow Operations to Improve Safety at Signals with Protected-Permissive Left Turn (PPLT)Operations : Project Summary

    DOT National Transportation Integrated Search

    2011-08-31

    The 2009 edition of the federal MUTCD suggests the use of the flashing yellow arrow (FYA) indication in lieu : of the green ball indication for permissive left-turn signals in the presence of separate signal heads. Currently, : there are no clear gui...

  7. 32 CFR 636.23 - Turning movements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... from a position as close to the right edge or right curb of the roadway as possible. (c) Left-turns will be made from a position as close to the center line as possible or from a left turn lane, if...

  8. 32 CFR 636.23 - Turning movements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... from a position as close to the right edge or right curb of the roadway as possible. (c) Left-turns will be made from a position as close to the center line as possible or from a left turn lane, if...

  9. Safety evaluation of signal installation with and without left turn lanes on two lane roads in rural and suburban areas.

    DOT National Transportation Integrated Search

    2014-10-01

    Data from 117 intersections on two lane roads in rural and suburban areas in North Carolina were used to determine the safety : effect of signalization with and without left turn lanes. This was a before-after study that was conducted using the empir...

  10. Training Strategies and Materials : Use of Flashing Yellow Operations to Improve Safety at Signals with Protected-Permissive Left Turn (PPLT) Operations

    DOT National Transportation Integrated Search

    2012-08-01

    TxDOT project 0-6568 Use of Flashing Yellow Operations to Improve Safety at Signals with : Protected-Permissive Left Turn (PPLT) Operations has developed guidelines for : implementation of FYA PPLT displays including general guidelines on the F...

  11. Kinematics and muscle activity of the head, lumbar and knee joints during 180° turning and sitting down task in older adults.

    PubMed

    Kuo, Fang-Chuan; Hong, Chang-Zern; Liau, Ben-Yi

    2014-01-01

    The "180° turning and sitting down task" is a very conscious movement that requires focusing on turning at the exact moment, and very few studies address on this topic in older adults. The purpose of the study was to compare kinematics and electromyography of the head, lumbar and knee joints during 180°turning in older and young adults. Twenty older adults and 20 younger adults were assessed. A 16-channel telemetry electromyography system with electrogoniometers and an inclinometer were used to record the head, lumbar and knee joint kinematic and electromyography data during the 180° turning. This movement had been further divided into 4 phases (braking, mid-stance, swing, and terminal loading) for analysis. There were significant differences in the joint displacement and muscular activity among the different phases. Comparison between groups showed that the older adults group had less lateral lumbar flexion, less knee flexion and lower velocity of the head and knee flexion compared to young adults during turning. The electromyography data of the left biceps femoris, left gastrocnemius and left erector spinae muscles in the older adults group showed significantly higher levels than in the young adults. Older adults need to adjust velocities of moving joints and increase the extensor synergy muscles of the back and the stance leg to provide posture stability. Kinematics and neuromuscular modulations of the head, lumbar and knee are required according to the various phases of the turn movements and change with aging. © 2013.

  12. Unifying the microscopic picture of His-containing turns: from gas phase model peptides to crystallized proteins.

    PubMed

    Sohn, Woon Yong; Habka, Sana; Gloaguen, Eric; Mons, Michel

    2017-07-14

    The presence in crystallized proteins of a local anchoring between the side chain of a His residue, located in the central position of a γ- or β-turn, and its local main chain environment, was assessed by the comparison of protein structures with relevant isolated model peptides. Gas phase laser spectroscopy, combined with relevant quantum chemistry methods, was used to characterize the γ- and β-turn structures in these model peptides. A conformer-selective NH stretch infrared study provided evidence for the formation in vacuo of two types of short-range H-bonded motifs, labelled ε-6 δ and δ- δ 7/π H , bridging the His side chain (in its gauche+ rotamer) to the neighbouring NH(i) and CO(i) sites of the backbone; each side chain-backbone motif was found to be specific of the tautomer (ε or δ) adopted by the His side chain in its neutral form. A close comparison between β- and γ-turns, selected from the Protein Data Bank, and the gas phase models demonstrated that a significant proportion of the gauche+ His rotamer distribution of proteins was well described by the corresponding gas phase H-bonded structures. This is consistent with the persistence of local 6 δ and δ 7/π H intramolecular interactions in proteins, emphasizing the relevance of gas phase data to secondary structures that are poorly accessible to solvents, e.g., in the case of a specific compact topology (Xxx-His β-turns). Deviations from the gas phase structures were also observed, mainly in His-Xxx β-turns, and assigned to solvent accessible turn structures. They were well accounted for by theoretical models of microhydrated turns, in which a few solvent molecules take over the gas phase motifs, constituting a water-mediated local anchoring of the His side chain to the backbone. Finally, the present gas phase benchmark models also pinpointed weaknesses in the protein structure determination by X-ray diffraction analysis; in particular, besides the lack of tautomer information

  13. Left-turn lanes at unsignalized median openings.

    DOT National Transportation Integrated Search

    2014-03-01

    Due to the frequent presence of median openings in urban arterial settings, the requirements for the deceleration and : storage of turning vehicles (e.g. AASHTO Green Book) often exceed the available length between two adjacent : openings which leave...

  14. Influence of slope steepness, foot position and turn phase on plantar pressure distribution during giant slalom alpine ski racing

    PubMed Central

    Falda-Buscaiot, Thomas; Hintzy, Frédérique; Rougier, Patrice; Lacouture, Patrick; Coulmy, Nicolas

    2017-01-01

    The purpose of this study was to investigate the evolution of ground reaction force during alpine skiing turns. Specifically, this study investigated how turn phases and slope steepness affected the whole foot normal GRF pattern while performing giant slalom turns in a race-like setting. Moreover, the outside foot was divided into different plantar regions to see whether those parameters affected the plantar pressure distribution. Eleven skiers performed one giant slalom course at race intensity. Runs were recorded synchronously using a video camera in the frontal plane and pressure insoles under both feet’s plantar surface. Turns were divided according to kinematic criteria into four consecutive phases: initiation, steering1, steering2 and completion; both steering phases being separated by the gate passage. Component of the averaged Ground Reaction Force normal to the ski’s surface(nGRF¯, /BW), and Pressure Time Integral relative to the entire foot surface (relPTI, %) parameters were calculated for each turn phases based on plantar pressure data. Results indicated that nGRF¯ under the total foot surface differed significantly depending on the slope (higher in steep sections vs. flat sections), and the turn phase (higher during steering2 vs. three other phases), although such modifications were observable only on the outside foot. Moreover, nGRF¯ under the outside foot was significantly greater than under the inside foot.RelPTI under different foot regions of the outside foot revealed a global shift from forefoot loading during initiation phase, toward heel loading during steering2 phase, but this was dependent on the slope studied. These results suggest a differentiated role played by each foot in alpine skiing turns: the outside foot has an active role in the turning process, while the inside foot may only play a role in stability. PMID:28472092

  15. Influence of slope steepness, foot position and turn phase on plantar pressure distribution during giant slalom alpine ski racing.

    PubMed

    Falda-Buscaiot, Thomas; Hintzy, Frédérique; Rougier, Patrice; Lacouture, Patrick; Coulmy, Nicolas

    2017-01-01

    The purpose of this study was to investigate the evolution of ground reaction force during alpine skiing turns. Specifically, this study investigated how turn phases and slope steepness affected the whole foot normal GRF pattern while performing giant slalom turns in a race-like setting. Moreover, the outside foot was divided into different plantar regions to see whether those parameters affected the plantar pressure distribution. Eleven skiers performed one giant slalom course at race intensity. Runs were recorded synchronously using a video camera in the frontal plane and pressure insoles under both feet's plantar surface. Turns were divided according to kinematic criteria into four consecutive phases: initiation, steering1, steering2 and completion; both steering phases being separated by the gate passage. Component of the averaged Ground Reaction Force normal to the ski's surface([Formula: see text], /BW), and Pressure Time Integral relative to the entire foot surface (relPTI, %) parameters were calculated for each turn phases based on plantar pressure data. Results indicated that [Formula: see text] under the total foot surface differed significantly depending on the slope (higher in steep sections vs. flat sections), and the turn phase (higher during steering2 vs. three other phases), although such modifications were observable only on the outside foot. Moreover, [Formula: see text] under the outside foot was significantly greater than under the inside foot.RelPTI under different foot regions of the outside foot revealed a global shift from forefoot loading during initiation phase, toward heel loading during steering2 phase, but this was dependent on the slope studied. These results suggest a differentiated role played by each foot in alpine skiing turns: the outside foot has an active role in the turning process, while the inside foot may only play a role in stability.

  16. Asymmetry of flight and escape turning responses in horses.

    PubMed

    Austin, N P; Rogers, L J

    2007-09-01

    We investigated whether horses display greater reactivity to a novel stimulus presented in the left compared to the right monocular visual field, and whether a population bias exists for escape turning when the same stimulus was presented binocularly. Domestic horses (N=30) were tested on three occasions by a person opening an umbrella five metres away and then approaching. The distance each horse moved away before stopping was measured. Distance was greatest for approach on the left side, indicating right hemisphere control of flight behaviour, and thus followed the same pattern found previously in other species. When order of monocular presentation was considered, an asymmetry was detected. Horses tested initially on the left side exhibited greater reactivity for left approach, whereas horses tested on the right side first displayed no side difference in reactivity. Perhaps left hemisphere inhibition of flight response allowed horses to learn that the stimulus posed no threat and this information was transferred to the right hemisphere. No population bias existed for the direction of escape turning, but horses that turned to the right when approached from the front were found to exhibit longer flight distances than those that turned to the left.

  17. Revised Planning Methodology For Signalized Intersections And Operational Analysis Of Exclusive Left-Turn Lanes, A Simulation-Based Method, Part - I: Literature Review (Final Report)

    DOT National Transportation Integrated Search

    1996-04-01

    THE STUDY INVESTIGATES THE APPLICATION OF SIMULATION ALONG WITH FIELD OBSERVATIONS FOR ESTIMATION OF EXCLUSIVE LEFT-TURN SATURATION FLOW RATE AND CAPACITY. THE ENTIRE RESEARCH HAS COVERED THE FOLLOWING PRINCIPAL SUBJECTS: (1) A SATURATION FLOW MODEL ...

  18. Quasi-phase-matching of the dual-band nonlinear left-handed metamaterial

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Yahong, E-mail: yhliu@nwpu.edu.cn; Song, Kun; Gu, Shuai

    2014-11-17

    We demonstrate a type of nonlinear meta-atom creating a dual-band nonlinear left-handed metamaterial (DNLHM). The DNLHM operates at two distinct left-handed frequency bands where there is an interval of one octave between the two center frequencies. Under the illumination of a high-power signal at the first left-handed frequency band corresponding to fundamental frequency (FF), second-harmonic generation (SHG) is observed at the second left-handed band. This means that our DNLHM supports backward-propagating waves both at FF and second-harmonic (SH) frequency. We also experimentally demonstrate quasi-phase-matching configurations for the backward SHG. This fancy parametric process can significantly transmits the SH generated bymore » an incident FF wave.« less

  19. Lattice modeling and calibration with turn-by-turn orbit data

    NASA Astrophysics Data System (ADS)

    Huang, Xiaobiao; Sebek, Jim; Martin, Don

    2010-11-01

    A new method that explores turn-by-turn beam position monitor (BPM) data to calibrate lattice models of accelerators is proposed. The turn-by-turn phase space coordinates at one location of the ring are first established using data from two BPMs separated by a simple section with a known transfer matrix, such as a drift space. The phase space coordinates are then tracked with the model to predict positions at other BPMs, which can be compared to measurements. The model is adjusted to minimize the difference between the measured and predicted orbit data. BPM gains and rolls are included as fitting variables. This technique can be applied to either the entire or a section of the ring. We have tested the method experimentally on a part of the SPEAR3 ring.

  20. Hand movements with a phase structure and gestures that depict action stem from a left hemispheric system of conceptualization.

    PubMed

    Helmich, I; Lausberg, H

    2014-10-01

    The present study addresses the previously discussed controversy on the contribution of the right and left cerebral hemispheres to the production and conceptualization of spontaneous hand movements and gestures. Although it has been shown that each hemisphere contains the ability to produce hand movements, results of left hemispherically lateralized motor functions challenge the view of a contralateral hand movement production system. To examine hemispheric specialization in hand movement and gesture production, ten right-handed participants were tachistoscopically presented pictures of everyday life actions. The participants were asked to demonstrate with their hands, but without speaking what they had seen on the drawing. Two independent blind raters evaluated the videotaped hand movements and gestures employing the Neuropsychological Gesture Coding System. The results showed that the overall frequency of right- and left-hand movements is equal independent of stimulus lateralization. When hand movements were analyzed considering their Structure, the presentation of the action stimuli to the left hemisphere resulted in more hand movements with a phase structure than the presentation to the right hemisphere. Furthermore, the presentation to the left hemisphere resulted in more right and left-hand movements with a phase structure, whereas the presentation to the right hemisphere only increased contralateral left-hand movements with a phase structure as compared to hand movements without a phase structure. Gestures that depict action were primarily displayed in response to stimuli presented in the right visual field than in the left one. The present study shows that both hemispheres possess the faculty to produce hand movements in response to action stimuli. However, the left hemisphere dominates the production of hand movements with a phase structure and gestures that depict action. We therefore conclude that hand movements with a phase structure and gestures that

  1. Four-phase or two-phase signal plan? A study on four-leg intersection by cellular automaton simulations

    NASA Astrophysics Data System (ADS)

    Jin, Cheng-Jie; Wang, Wei; Jiang, Rui

    2016-08-01

    The proper setting of traffic signals at signalized intersections is one of the most important tasks in traffic control and management. This paper has evaluated the four-phase traffic signal plans at a four-leg intersection via cellular automaton simulations. Each leg consists of three lanes, an exclusive left-turn lane, a through lane, and a through/right-turn lane. For a comparison, we also evaluate the two-phase signal plan. The diagram of the intersection states in the space of inflow rate versus turning ratio has been presented, which exhibits four regions: In region I/II/III, congestion will propagate upstream and laterally and result in queue spillover with both signal plans/two-phase signal plan/four-phase signal plan, respectively. Therefore, neither signal plan works in region I, and only the four-phase signal plan/two-phase signal plan works in region II/III. In region IV, both signal plans work, but two-phase signal plan performs better in terms of average delays of vehicles. Finally, we study the diagram of the intersection states and average delays in the asymmetrical configurations.

  2. Family matters: Directionality of turning bias while kissing is modulated by context.

    PubMed

    Sedgewick, Jennifer R; Elias, Lorin J

    2016-01-28

    When leaning forward to kiss to a romantic partner, individuals tend to direct their kiss to the right more often than the left. Studies have consistently demonstrated this kissing asymmetry, although other factors known to influence lateral biases, such as sex or situational context, had yet to be explored. The primary purpose of our study was to investigate if turning direction was consistent between a romantic (parent-parent) and parental (parent-child) kissing context, and secondly, to examine if sex differences influenced turning bias between parent-child kissing partners. An archival analysis coded the direction of turning bias for 161 images of romantic kissing (mothers kissing fathers) and 529 images of parental kissing (mothers or fathers kissing sons or daughters). The results indicated that the direction of turning bias differed between kissing contexts. As expected, a right-turn bias was observed for romantic kissing; however, a left-turn bias was exhibited for parental kissing. There was no significant difference of turning bias between any parent-child kissing partners. Interpretations for the left-turn bias discuss parental kissing as a learned lateral behaviour.

  3. Intrinsic folding of small peptide chains: spectroscopic evidence for the formation of beta-turns in the gas phase.

    PubMed

    Chin, Wutharath; Dognon, Jean-Pierre; Piuzzi, François; Tardivel, Benjamin; Dimicoli, Iliana; Mons, Michel

    2005-01-19

    Laser desorption of model peptides coupled to laser spectroscopic techniques enables the gas-phase observation of genuine secondary structures of biology. Spectroscopic evidence for the formation of beta-turns in gas-phase peptide chains containing glycine and phenylalanine residues establishes the intrinsic stability of these forms and their ability to compete with other stable structures. The precise characterization of local minima on the potential energy surface from IR spectroscopy constitutes an acute assessment for the state-of-the-art quantum mechanical calculations also presented. The observation of different types of beta-turns depending upon the residue order within the sequence is found to be consistent with the residue propensities in beta-turns of proteins, which suggests that the prevalence of glycine in type II and II' turns stems essentially from an energetic origin, already at play under isolated conditions.

  4. Effects of turning and through lane sharing on traffic performance at intersections

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Sun, Jian-Qiao

    2016-02-01

    Turning vehicles strongly influence traffic flows at intersections. Effective regulation of turning vehicles is important to achieve better traffic performance. This paper studies the impact of lane sharing and turning signals on traffic performance at intersections by using cellular automata. Both right-turn and left-turn lane sharing are studied. Interactions between vehicles and pedestrians are considered. The transportation efficiency, road safety and energy economy are the traffic performance metrics. Extensive simulations are carried out to study the traffic performance indices. It is observed that shared turning lanes and permissive left-turn signal improve the transportation efficiency and reduce the fuel consumption in most cases, but the safety is usually sacrificed. It is not always beneficial for the through vehicles when they are allowed to be in the turning lanes.

  5. Head-turning asymmetries during kissing and their association with lateral preference.

    PubMed

    Ocklenburg, Sebastian; Güntürkün, Onur

    2009-01-01

    A head-turning bias to the right side is one of the earliest functional asymmetries in human development and is already present during the final weeks of gestation. To test whether head-turning preference is related to other lateral preferences in adults, kissing behaviour of participants towards a symmetrical doll was observed to assess their spontaneous head-turning preference. Additionally, participants' individual handedness, footedness, and eye preference were determined using questionnaires. A significant difference in handedness and footedness, but not eye preference, was found between left- and right-kissers, with right-kissers showing a stronger right-sided bias than left-kissers. These results support the assumption that the head-turning bias in humans may be able to induce or enhance other asymmetries of perception and action.

  6. Proteomics analysis identified peroxiredoxin 2 involved in early-phase left ventricular impairment in hamsters with cardiomyopathy.

    PubMed

    Kuzuya, Kentaro; Ichihara, Sahoko; Suzuki, Yuka; Inoue, Chisa; Ichihara, Gaku; Kurimoto, Syota; Oikawa, Shinji

    2018-01-01

    Given the hypothesis that inflammation plays a critical role in the progression of cardiovascular diseases, the aim of the present study was to identify new diagnostic and prognostic biomarkers of myocardial proteins involved in early-phase cardiac impairment, using proteomics analysis. Using the two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) combined with MALDI-TOF/TOF tandem mass spectrometry, we compared differences in the expression of proteins in the whole left ventricles between control hamsters, dilated cardiomyopathic hamsters (TO-2), and hypertrophy cardiomyopathic hamsters (Bio14.6) at 6 weeks of age (n = 6, each group). Proteomic analysis identified 10 protein spots with significant alterations, with 7 up-regulated and 3 down-regulated proteins in the left ventricles of both TO-2 and Bio 14.6 hamsters, compared with control hamsters. Of the total alterations, peroxiredoxin 2 (PRDX2) showed significant upregulation in the left ventricles of TO-2 and Bio 14.6 hamsters. Our data suggest that PRDX2, a redox regulating molecule, is involved in early-phase left ventricular impairment in hamsters with cardiomyopathy.

  7. Gas-Phase Folding of Small Glutamine Containing Peptides: Sidechain Hydrogen Bonding Stabilizes β-turns

    NASA Astrophysics Data System (ADS)

    Walsh, Patrick S.; Blodgett, Karl N.; McBurney, Carl; Gellman, Samuel H.; Zwier, Timothy S.

    Glutamine is vitally important to a class of neurodegenerative diseases called poly-glutamine (poly-Q) repeat diseases such as Huntington's Disease (HD). Recent studies have revealed a pathogenic pathway that proceeds through misfolding of poly-Q regions into characteristic β-turn/ β-hairpin structures that are highly correlated with toxicity. The inherent conformational preferences of small glutamine containing peptides (Ac-Q-Q-NHBn and Ac-A-Q-NHBn) were studied using conformation-specific IR and UV spectroscopies, with the goal of probing the delicate interplay between three competitive hydrogen bonding motifs: backbone-backbone, sidechain-backbone, and sidechain-sidechain hydrogen bonds. Laser desorption, coupled with a supersonic expansion, was used to introduce the non-thermally labile sample into the gas-phase. Resonant ion-dip infrared (RIDIR) spectroscopy is a powerful tool for recording the vibrational spectra of single conformational isomers and was used here to reveal the innate structural preferences of the glutamine containing peptides. Experimental results are compared against density functional calculations to arrive at firm conformational assignments. Our results demonstrate a striking preference for β-turn formation in the non-polar environment of the gas-phase. Previous Affiliation: Purdue University, Department of Chemistry.

  8. Left Versus Right: Does Location Matter for Refractory Metastatic Colorectal Cancer Patients in Phase 1 Clinical Trials?

    PubMed

    Arora, Sukeshi Patel; Ketchum, Norma S; Michalek, Joel; Gelfond, Jonathon; Mahalingam, Devalingam

    2017-04-22

    Location of the primary tumor is prognostic and predictive of efficacy with VEGF-inhibitors (I) versus EGFR-I given first-line to metastatic colorectal cancer (mCRC) patients. However, little is known regarding the effect of location on prognosis and prediction in refractory mCRC. We assessed the efficacy of VEGF-I and EGFR-I in regards to location of the primary tumor in patients with refractory mCRC enrolled in early phase studies. A historical cohort analysis of mCRC patients, including 44 phase I trials our institution, from March 2004 to September 2012. Median Progression free survival (mPFS) and overall survival (mOS) were estimated from Kaplan-Meier curves and groups were statistically compared with the log-rank test. One hundred thirty-nine patients with a median age 59 (33-81). 73.9% received 3+ lines of therapy. All KRAS wild-type patients had received prior EGFR-I. right 20.9%, left 61.9%, and transverse 4.3%. For survival analysis, transverse CRC were included with right. Of the 112 patients, mOS was left (N = 80) 6.6 months versus right (N = 32) 5.9 months, P = 0.18. mPFS was left (n = 86) 2.0 months versus right (N = 35) 2.0 months, P = 0.76. In subgroup analysis, survival was significant for KRAS wild-type patients with left-sided mCRC had mOS of 6.2 months with other agents versus 9.4 months with EGFR-I (P = 0.03). In phase 1 clinical trials, although location alone was not prognostic in heavily pretreated patients, left-sided mCRC had improved survival with EGFR-I. Despite progression on EGFR-I, left-sided KRAS wild mCRC patients should be considered for phase 1 studies of agents targeting growth factor pathways.

  9. Turning off artistic ability: the influence of left DBS in art production.

    PubMed

    Drago, V; Foster, P S; Okun, M S; Cosentino, F I I; Conigliaro, R; Haq, I; Sudhyadhom, A; Skidmore, F M; Heilman, K M

    2009-06-15

    The influence of Parkinson's disease (PD) as well as deep brain stimulation (DBS) on visual-artistic production of people who have been artists is unclear. We systematically assessed the artistic-creative productions of a patient with PD who was referred to us for management of a left subthalamic region (STN) DBS. The patient was an artist before her disease started, permitting us to analyze changes in her artistic-creative production over the course of the illness and during her treatment with DBS. We collected her paintings from four time periods: Time 1 (Early Pre-Presymptomatic), Time 2 (Later Presymptomatic), Time 3 (Symptomatic), and Time 4 (DBS Symptomatic). A total of 59 paintings were submitted to a panel of judges, who rated the paintings on 6 different artistic qualities including: aesthetics, closure, evocative impact, novelty, representation, technique. Aesthetics and evocative impact significantly declined from Time 2 to Time 4. Representation and technique indicated a curvilinear relationship, with initial improvement from Time 1 to Time 2 followed by a decline from Time 2 to Time 4. These results suggest that left STN/SNR-DBS impacted artistic performances in our patient. The reason for these alterations is not known, but it might be that alterations of left hemisphere functions induce a hemispheric bias reducing the influence the right hemisphere which is important for artistic creativity. The left hemisphere itself plays a critical role in artistic creativity and DBS might have altered left hemisphere functions or altered the mesolimbic system which might have also influenced creativity. Future studies will be required to learn how PD and DBS influence creativity.

  10. Effective measures to restrict vehicle turning movements.

    DOT National Transportation Integrated Search

    2015-12-01

    This study evaluated alternatives to raised/non-traversable medians on driveways and approaches. : Raised medians are often considered as an effective technique to limit direct left-turns that may be due : to a significant number of conflict points. ...

  11. Characteristics of turn signal use at intersections in baseline naturalistic driving.

    PubMed

    Sullivan, John M; Bao, Shan; Goudy, Roy; Konet, Heather

    2015-01-01

    The purpose of this study was to determine whether a driver's use of turn signals is sufficiently reliable to forecast a vehicle's future path around an intersection, when detailed information about the intersection is unavailable. Naturalistic observations of turn signal use among 108 drivers on surface streets were extracted from the baseline portion of a field operational test of a safety system. Left and right turns that resulted in heading changes of between 70 and 110° and turn radii between 18 and 90 m were selected from the dataset. The odds that a driver would signal a turn were modeled as a function of road type, turn direction, presence of a forward vehicle, whether the vehicle stopped before the turn, and driver age and gender. Overall, 25 percent of left turns and 29 percent of right turns were not signaled. Road type, turn direction, and presence of a forward vehicle were found to influence the odds that a turn is signaled, while gender and age of the driver did not. The results suggest that situational factors like road type and turn direction are more powerful predictors of whether a turn will be signaled than either age or gender. Signaling on major and minor surface roads was about 5 times more likely than on local roads and 1.5 times more likely when a forward vehicle was present, suggesting a possible effect of traffic volume. It was concluded that turn signal activation alone may be insufficiently reliable to forecast a driver's path. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Induction motor inter turn fault detection using infrared thermographic analysis

    NASA Astrophysics Data System (ADS)

    Singh, Gurmeet; Anil Kumar, T. Ch.; Naikan, V. N. A.

    2016-07-01

    Induction motors are the most commonly used prime movers in industries. These are subjected to various environmental, thermal and load stresses that ultimately reduces the motor efficiency and later leads to failure. Inter turn fault is the second most commonly observed faults in the motors and is considered the most severe. It can lead to the failure of complete phase and can even cause accidents, if left undetected or untreated. This paper proposes an online and non invasive technique that uses infrared thermography, in order to detect the presence of inter turn fault in induction motor drive. Two methods have been proposed that detect the fault and estimate its severity. One method uses transient thermal monitoring during the start of motor and other applies pseudo coloring technique on infrared image of the motor, after it reaches a thermal steady state. The designed template for pseudo-coloring is in acquiescence with the InterNational Electrical Testing Association (NETA) thermographic standard. An index is proposed to assess the severity of the fault present in the motor.

  13. CP-violation phases and Majorana neutrino magnetic moments in left-right models

    NASA Astrophysics Data System (ADS)

    Delepine, D.; Novales-Sánchez, H.

    2016-10-01

    An implication of nonzero neutrino masses is the existence of neutrino magnetic moments, which arise in extensions of the Standard Model. Among the whole set of electromagnetic properties, these physical quantities have received much attention, both theoretically and experimentally. In the present paper we review the contributions to neutrino magnetic moments from new physics described by a leff-right model, with Majorana neutrinos, which might be as large as 10-11μB. These electromagnetic moments depend on Majorana phases. It turns out that, in presence of CP violation, specific sets of values of these phases can cancel up to two magnetic moments, while the remaining one must necessarily be nonzero and large.

  14. Effects of a continuous lateral turning device on pressure relief.

    PubMed

    Do, Nam Ho; Kim, Deog Young; Kim, Jung-Hoon; Choi, Jong Hyun; Joo, So Young; Kang, Na Kyung; Baek, Yoon Su

    2016-01-01

    [Purpose] The purpose of this study was to examine the pressure-relieving effects of a continuous lateral turning device on common pressure ulcer sites. [Subjects] Twenty-four healthy adults participated. [Methods] The design of our continuous lateral turning device was motivated by the need for an adequate pressure-relieving device for immobile and/or elderly people. The procedure of manual repositioning is embodied in our continuous lateral turning device. The interface pressure and time were measured, and comfort grade was evaluated during sessions of continuous lateral turning at 0°, 15°, 30°, and 45°. We quantified the pressure-relieving effect using peak pressure, mean pressure, and pressure time integration. [Results] Participants demonstrated pressure time integration values below the pressure-time threshold at 15°, 30°, and 45° at all the common pressure ulcer sites. Moreover, the most effective angles for pressure relief at the common pressure ulcer sites were 30° at the occiput, 15° at the left scapula, 45° at the right scapula, 45° at the sacrum, 15° at the right heel, and 30° at the left heel. However, angles greater than 30° induced discomfort. [Conclusion] Continuous lateral turning with our specially designed device effectively relieved the pressure of targeted sites. Moreover, the suggested angles of continuous lateral turning can be used to relieve pressure at targeted sites.

  15. Safety impact of permitting right-turn-on-red : a report to Congress

    DOT National Transportation Integrated Search

    1994-12-01

    The Energy Policy Act of 1992 required NHTSA to conduct a study of the safety impact of permitting right and left turns on red lights. The report presents a brief summary of the current status of State implementation of laws permitting right and left...

  16. Advantages in exploring a new environment with the left eye in lizards.

    PubMed

    Bonati, Beatrice; Csermely, Davide; Sovrano, Valeria Anna

    2013-07-01

    Lizards (Podarcis muralis) preferentially use the left eye during spatial exploration in a binocular condition. Here we allowed 44 adult wild lizards to explore an unknown maze for 20 min under a temporary monocular condition whilst recording their movements, particularly the direction of turns made whilst walking within the maze. Lizards with a patch on their right eye, i.e. using their left eye to monitor the environment, moved faster than lizards with a patch on their left eye when turning both leftward and rightward in a T-cross. Hence, right eye-patched lizards were faster than left eye-patched lizards also in turning right, although their right eye was covered. Thus, lizards that could use the left eye/right hemisphere to attend spatial cues appeared to have more control and to be more prompt in exploring the maze. In addition, female lizards with their left eye covered stopped very frequently when they reached crosses, showing a high level of indecision. Results confirm that P. muralis lizards using their left eye only in exploring a new environment react faster and more efficiently than those using the right eye only in exploration. Hence lateralisation of spatial stimuli mediated by the left eye/right hemisphere could provide an advantage to this species. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Perspectives and Open Problems in the Early Phases of Left-Right Patterning

    PubMed Central

    Vandenberg, Laura N.; Levin, Michael

    2009-01-01

    Summary Embryonic left-right (LR) patterning is a fascinating aspect of embryogenesis. The field currently faces important questions about the origin of LR asymmetry, the mechanisms by which consistent asymmetry is imposed on the scale of the whole embryo, and the degree of conservation of early phases of LR patterning among model systems. Recent progress on planar cell polarity and cellular asymmetry in a variety of tissues and species provides a new perspective on the early phases of LR patterning. Despite the huge diversity in body-plans over which consistent LR asymmetry is imposed, and the apparent divergence in molecular pathways that underlie laterality, the data reveal conservation of physiological modules among phyla and a basic scheme of cellular chirality amplified by a planar cell polarity-like pathway over large cell fields. PMID:19084609

  18. No Community Left Behind

    ERIC Educational Resources Information Center

    Schlechty, Phillip C.

    2008-01-01

    The debate over the reauthorization of No Child Left Behind (NCLB) generally overlooks--or looks past--what may be the most fundamental flaw in that legislation. As the law is now written, decisions regarding what the young should know and be able to do are removed from the hands of parents and local community leaders and turned over to officials…

  19. Class Identification Efficacy in Piecewise GMM with Unknown Turning Points

    ERIC Educational Resources Information Center

    Ning, Ling; Luo, Wen

    2018-01-01

    Piecewise GMM with unknown turning points is a new procedure to investigate heterogeneous subpopulations' growth trajectories consisting of distinct developmental phases. Unlike the conventional PGMM, which relies on theory or experiment design to specify turning points a priori, the new procedure allows for an optimal location of turning points…

  20. Characterization of beta-turn and Asx-turns mimicry in a model peptide: stabilization via C--H . . . O interaction.

    PubMed

    Thakur, A K; Kishore, R

    2006-04-15

    The chemical synthesis and single-crystal X-ray diffraction analysis of a model peptide, Boc-Thr-Thr-NH2 (1) comprised of proteinogenic residues bearing an amphiphilic Cbeta -stereogenic center, has been described. Interestingly, the analysis of its molecular structure revealed the existence of a distinct conformation that mimics a typical beta-turn and Asx-turns, i.e., the two Thr residues occupy the left- and right-corner positions. The main-chain torsion angles of the N- and C-terminal residues i.e., semiextended: phi = -68.9 degrees , psi = 128.6 degrees ; semifolded: phi = -138.1 degrees , psi = 2.5 degrees conformations, respectively, in conjunction with a gauche- disposition of the obligatory C-terminus Thr CgammaH3 group, characterize the occurrence of the newly described beta-turn- and Asx-turns-like topology. The preferred molecular structure is suggested to be stabilized by an effective nonconventional main-chain to side-chain Ci=O . . . H--Cgamma(i+2)-type intraturn hydrogen bond. Noteworthy, the observed topology of the resulting 10-membered hydrogen-bonded ring is essentially similar to the one perceived for a classical beta-turn and the Asx-turns, stabilized by a conventional intraturn hydrogen bond. Considering the signs as well as magnitudes of the backbone torsion angles and the orientation of the central peptide bond, the overall mimicked topology resembles the type II beta-turn or type II Asx-turns. An analysis of Xaa-Thr sequences in high-resolution X-ray elucidated protein structures revealed the novel topology prevalence in functional proteins (unpublished). In view of indubitable structural as well as functional importance of nonconventional interactions in bioorganic and biomacromolecules, we intend to highlight the participation of Thr CgammaH in the creation of a short-range C=O . . . H--Cgamma -type interaction in peptides and proteins. Copyright 2006 Wiley Periodicals, Inc.

  1. Model-independent analysis of the Fermilab Tevatron turn-by-turn beam position monitor measurements

    NASA Astrophysics Data System (ADS)

    Petrenko, A. V.; Valishev, A. A.; Lebedev, V. A.

    2011-09-01

    Coherent transverse beam oscillations in the Tevatron were analyzed with the model-independent analysis (MIA) technique. This allowed one to obtain the model-independent values of coupled betatron amplitudes, phase advances, and dispersion function around the ring from a single dipole kick measurement. In order to solve the MIA mode mixing problem which limits the accuracy of determination of the optical functions, we have developed a new technique of rotational MIA mode untangling. The basic idea is to treat each beam position monitor (BPM) as two BPMs separated in a ring by exactly one turn. This leads to a simple criterion of MIA mode separation: the betatron phase advance between any BPM and its counterpart shifted by one turn should be equal to the betatron tune and therefore should not depend on the BPM position in the ring. Furthermore, we describe a MIA-based technique to locate vibrating magnets in a storage ring.

  2. Eye and head motion during head turns in spaceflight

    NASA Technical Reports Server (NTRS)

    Thornton, William E.; Uri, John J.; Moore, Thomas P.; Pool, Sam L.

    1988-01-01

    Eye-head motion was studied pre-, in- and postflight during single voluntary head turns. A transient increase in vestibulo-ocular reflex (VOR) gain occurred early in the flight, but later trended toward normal. This increased gain was produced by a relative increase in eye counterrotation velocity. Asymmetries in gain with right and left turns also occurred, caused by asymmetries in eye counterrotation velocities. These findings were remarkably similar to those from Soviet primate studies using gaze fixation targets, except the human study trended more rapidly toward normal. These findings differ substantially from those measuring VOR gain by head oscillation, in which no significant changes were found inflight. No visual disturbances were noted in either test condition or in normal activities. These head turn studies are the only ones to date documenting any functional change in VOR in weightlessness.

  3. Hydrogen-bonded turns in proteins: The case for a recount

    PubMed Central

    Panasik, Nick; Fleming, Patrick J.; Rose, George D.

    2005-01-01

    β-Turns are sites at which proteins change their overall chain direction, and they occur with high frequency in globular proteins. The Protein Data Bank has many instances of conformations that resemble β-turns but lack the characteristic N–H(i) → O=C(i − 3) hydrogen bond of an authentic β-turn. Here, we identify potential hydrogen-bonded β-turns in the coil library, a Web-accessible database utility comprised of all residues not in repetitive secondary structure, neither α-helix nor β-sheet (http://www.roselab.jhu.edu/coil). In particular, candidate turns were identified as four-residue segments satisfying highly relaxed geometric criteria but lacking a strictly defined hydrogen bond. Such candidates were then subjected to a minimization protocol to determine whether slight changes in torsion angles are sufficient to shift the conformation into reference-quality geometry without deviating significantly from the original structure. This approach of applying constrained minimization to known structures reveals a substantial population of previously unidentified, stringently defined, hydrogen-bonded β-turns. In particular, 33% of coil library residues were classified as β-turns prior to minimization. After minimization, 45% of such residues could be classified as β-turns, with another 8% in 310 helixes (which closely resemble type III β-turns). Of the remaining coil library residues, 37% have backbone dihedral angles in left-handed polyproline II structure. PMID:16251367

  4. Hydrogen-bonded turns in proteins: the case for a recount.

    PubMed

    Panasik, Nick; Fleming, Patrick J; Rose, George D

    2005-11-01

    Beta-turns are sites at which proteins change their overall chain direction, and they occur with high frequency in globular proteins. The Protein Data Bank has many instances of conformations that resemble beta-turns but lack the characteristic N-H(i) --> O=C(i - 3) hydrogen bond of an authentic beta-turn. Here, we identify potential hydrogen-bonded beta-turns in the coil library, a Web-accessible database utility comprised of all residues not in repetitive secondary structure, neither alpha-helix nor beta-sheet (http://www.roselab.jhu.edu/coil). In particular, candidate turns were identified as four-residue segments satisfying highly relaxed geometric criteria but lacking a strictly defined hydrogen bond. Such candidates were then subjected to a minimization protocol to determine whether slight changes in torsion angles are sufficient to shift the conformation into reference-quality geometry without deviating significantly from the original structure. This approach of applying constrained minimization to known structures reveals a substantial population of previously unidentified, stringently defined, hydrogen-bonded beta-turns. In particular, 33% of coil library residues were classified as beta-turns prior to minimization. After minimization, 45% of such residues could be classified as beta-turns, with another 8% in 3(10) helixes (which closely resemble type III beta-turns). Of the remaining coil library residues, 37% have backbone dihedral angles in left-handed polyproline II structure.

  5. Alterations in left ventricular volumes induced by Valsalva manoeuvre

    NASA Technical Reports Server (NTRS)

    Brooker, J. Z.; Alderman, E. L.; Harrison, D. C.

    1974-01-01

    Five patients were studied with left ventriculography during different phases of the Valsalva manoeuvre. Small doses of contrast medium allowed adequate repetitive visualization of the left ventricle for volume calculation. During strain phase, the volume of the left ventricle decreased by nearly 50 per cent in each case, and stroke volume and cardiac output also dropped strikingly. Release of straining was attended by a sharp rebound of left ventricular volume to control levels, with a transient surge of increased cardiac output 42 per cent above that of the resting state.

  6. A case of left inferior vena cava.

    PubMed

    Yano, R; Hayakawa, D; Emura, S; Chen, H; Ozawa, Y; Taguchi, H; Shoumura, S

    2001-12-01

    A case of left inferior vena cava (IVC) was found in a 72-year-old male cadaver during student dissection practice in 1999 at Gifu University School of Medicine. It was formed by junction of the left and right common iliac veins at the lower left corner of the 5th lumbar vertebra. This IVC (15-mm caliber) ascended 82 mm along the left side of the abdominal aorta dorsally to the ureter. Receiving the left renal vein, it became 21 mm in caliber and ran obliquely upward for 43 mm across the abdominal aorta. As soon as it received two right renal veins at the level of the 2nd lumbar vertebra, the IVC (25-mm caliber) turned directly above. The present case belongs to Type C of the classification of McClure and Butler (1925), which is based on the combinations of the left and right IVCs, and on their location relative to the ureters. The present case also belongs to Type 1 of the classification of Yoshida et al. (1981). We consider that left IVC in the present case is mainly caused by disappearance of the right supracardinal vein and persistence of the left one during the embryological development of the IVC.

  7. The impact of general permissive right and left turn on red legislation in Virginia.

    DOT National Transportation Integrated Search

    1978-01-01

    Right turn on red (RTOR) maneuvers have been permitted at signalized intersections in Virginia since 1972. However, until January 1, 1977, following a study requested by the General Assembly, the maneuver was restricted to intersections at which a si...

  8. Opportunities and limitations for intersection collision intervention-A study of real world 'left turn across path' accidents.

    PubMed

    Sander, Ulrich

    2017-02-01

    Turning across the path of oncoming vehicle accidents are frequent and dangerous. To date not many car manufacturers have introduced Automated Emergency Braking (AEB) systems addressing this type of conflict situation, but it is foreseeable that these scenarios will be part of the Euro NCAP 2020 rating. Nine out of ten collisions are caused by the driver of the turning vehicle. An AEB system evaluating the ego and conflict vehicle driver's possibilities to avoid a pending crash by either braking or steering was specified for application in various constellations of vehicle collisions. In virtual simulation, AEB system parameters were varied, covering parameters that are relevant for driver comfort such as longitudinal and lateral acceleration (to define avoidance possibilities), expected steering maneuvers to avoid conflict, and intervention response characteristics (brake delay and ramp up) to assess the safety benefit. The reference simulation showed a potential of the AEB system in the turning vehicle to avoid approximately half of the collisions. An AEB system of the straight going vehicle was less effective. The effectiveness of the turning vehicle's AEB system increases if spatial limitations for the collision-avoidance steering maneuver are known. Such information could be provided by sensors detecting free space in or around the road environment or geographical information shared via vehicle to cloud communication. AEB interventions rarely result in collision avoidance for turning vehicles with speeds above 40km/h or for straight going vehicles with speeds above 60km/h. State of the art field-of-views of forward looking sensing systems designed for AEB rear-end interventions are capable of addressing turning across path situations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. A Phase-Conjugate-Mirror Inspired Approach for Building Cloaking Structures with Left-handed Materials

    PubMed Central

    Zheng, Guoan; Heng, Xin; Yang, Changhuei

    2009-01-01

    A phase conjugate mirror (PCM) has a remarkable property of cancellation the back-scattering wave of the lossless scatterers. The similarity of a phase conjugate mirror to the interface of a matched RHM (right-handed material) and a LHM (left-handed material) prompts us to explore the potentials of using the RHM-LHM structure to achieve the anti-scattering property of the PCM. In this paper, we present two such structures. The first one is a RHM-LHM cloaking structure with a lossless arbitrary-shape scatterer imbedded in the RHM and its left-handed duplicate imbedded in the matched LHM. It is shown that such a structure is transparent to the incident electromagnetic (EM) field. As a special case of this structure, we proposed an EM tunnel that allows EM waves to spatially transport to another location in space without significant distortion and reflection. The second one is an RHM-PEC (perfect electric conductor)-LHM cloaking structure, which is composed of a symmetric conducting shell embedded in the interface junction of an RHM and the matched LHM layer. Such a structure presents an anomalously small scattering cross-section to an incident propagating EM field, and the interior of the shell can be used to shield small objects (size comparable to the wavelength) from interrogation. We report the results of 2D finite-element-method (FEM) simulations that were performed to verify our idea, and discuss the unique properties of the proposed structures as well as their limitations. PMID:20126415

  10. A low-dose, dual-phase cardiovascular CT protocol to assess left atrial appendage anatomy and exclude thrombus prior to left atrial intervention.

    PubMed

    Lazoura, Olga; Ismail, Tevfik F; Pavitt, Christopher; Lindsay, Alistair; Sriharan, Mona; Rubens, Michael; Padley, Simon; Duncan, Alison; Wong, Tom; Nicol, Edward

    2016-02-01

    Assessment of the left atrial appendage (LAA) for thrombus and anatomy is important prior to atrial fibrillation (AF) ablation and LAA exclusion. The use of cardiovascular CT (CCT) to detect LAA thrombus has been limited by the high incidence of pseudothrombus on single-pass studies. We evaluated the diagnostic accuracy of a two-phase protocol incorporating a limited low-dose delayed contrast-enhanced examination of the LAA, compared with a single-pass study for LAA morphological assessment, and transesophageal echocardiography (TEE) for the exclusion of thrombus. Consecutive patients (n = 122) undergoing left atrial interventions for AF were assessed. All had a two-phase CCT protocol (first-past scan plus a limited, 60-s delayed scan of the LAA) and TEE. Sensitivity, specificity, diagnostic accuracy, positive (PPV) and negative predictive values (NPV) were calculated for the detection of true thrombus on first-pass and delayed scans, using TEE as the gold standard. Overall, 20/122 (16.4 %) patients had filling defects on the first-pass study. All affected the full delineation of the LAA morphology; 17/20 (85 %) were confirmed as pseudo-filling defects. Three (15 %) were seen on late-pass and confirmed as true thrombi on TEE; a significant improvement in diagnostic performance relative to a single-pass scan (McNemar Chi-square 17, p < 0.001). The sensitivity, specificity, diagnostic accuracy, PPV and NPV was 100, 85.7, 86.1, 15.0 and 100 % respectively for first-pass scans, and 100 % for all parameters for the delayed scans. The median (range) additional radiation dose for the delayed scan was 0.4 (0.2-0.6) mSv. A low-dose delayed scan significantly improves the identification of true LAA anatomy and thrombus in patients undergoing LA intervention.

  11. Aircraft control forces and EMG activity: comparison of novice and experienced pilots during simulated rolls, loops and turns.

    PubMed

    Hewson, D J; McNair, P J; Marshall, R N

    2000-08-01

    Flying an aircraft requires a considerable degree of coordination, particularly during aerobatic activities such as rolls, loops and turns. Only one previous study has examined the magnitude of muscle activity required to fly an aircraft, and that was restricted to takeoff and landing maneuvers. The aim of this study was to examine the phasing of muscle activation and control forces of novice and experienced pilots during more complex simulated flight maneuvers. There were 12 experienced and 9 novice pilots who were tested on an Aermacchi flight simulator while performing a randomized set of rolling, looping, and turning maneuvers. Four different runaway trim settings were used to increase the difficulty of the turns (elevator-up, elevator-down, aileron-left, and aileron-right). Variables recorded included aircraft attitude, pilot applied forces, and electromyographic (EMG) activity. Discriminant function analysis was used to distinguish between novice and experienced pilots. Over all maneuvers, 70% of pilots were correctly classified as novice or experienced. Better levels of classification were achieved when maneuvers were analyzed individually (67-91%), although the maneuvers that required the greatest force application, elevator-up turns, were unable to discriminate between novice and experienced pilots. There were no differences in the phasing of muscle activity between experienced and novice pilots. The only consistent difference in EMG activity between novice and experienced pilots was the reduced EMG activity in the wrist extensors of experienced pilots (p < 0.05). The increased wrist extensor activity of the novice pilots is indicative of a distal control strategy, whereby distal muscles with smaller motor units are used to perform a task that requires precise control. Muscle activity sensors could be used to detect the onset of high G maneuvers prior to any change in aircraft attitude and control G-suit inflation accordingly.

  12. Neglect severity after left and right brain damage.

    PubMed

    Suchan, Julia; Rorden, Chris; Karnath, Hans-Otto

    2012-05-01

    While unilateral spatial neglect after left brain damage is undoubtedly less common than spatial neglect after a right hemisphere lesion, it is also assumed to be less severe. Here we directly test this latter hypothesis using a continuous measure of neglect severity: the so-called Center of Cancellation (CoC). Rorden and Karnath (2010) recently validated this index for right brain damaged neglect patients. A first aim of the present study was to evaluate this new measure for spatial neglect after left brain damage. In a group of 48 left-sided stroke patients with and without neglect, a score greater than -0.086 on the Bells Test and greater than -0.024 on the Letter Cancellation Task turned out to indicate neglect behavior for acute left brain damaged patients. A second aim was to directly compare the severity of spatial neglect after left versus right brain injury by using the new CoC measure. While neglect is less frequent following left than right hemisphere injury, we found that when this symptom occurs it is of similar severity in acute left brain injury as in patients after acute right brain injury. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Evaluating the Operational Features of an Unconventional Dual-Bay U-Turn Design for Intersections.

    PubMed

    Xiang, Yun; Li, Zhibin; Wang, Wei; Chen, Jingxu; Wang, Hao; Li, Ye

    2016-01-01

    Median U-turn intersection treatment (MUTIT) has been considered an alternative measure to reduce congestion and traffic conflict at intersection areas. The MUTIT is sometimes difficult to implement in the field because it requires wide median on arterials for U-turn vehicles. The objective of this study is to introduce an unconventional U-turn treatment (UUT) for intersections which requires less median space but is also effective. The UUT has a dual-bay design with different turning radiuses for small and large vehicles. The VISSIM simulation model was developed to evaluate the operational features of the UUT. The model was calibrated using data collected from intersections in China. The capacity, delay and number of stops were evaluated and compared with the direct-left-turn (DLT) for the same intersections. The results showed that the UUT significantly improved the operations at intersection areas, especially when volume/capacity ratio is small, and ratio of left-turn to through traffic is small. With the UUT, the capacity is increased by 9.81% to 10.38%, vehicle delay is decreased by 18.5% to 40.1%, and number of stops is decreased by 23.19% to 36.62%, when volume/capacity ratio is less than 0.50. The study also found that traffic efficiency could be further improved when the UUT is designed in conjunction with signal control. In the case, the UUT plus signalized control increases the capacity by 25% to 26.02%, decreases vehicle delay by 50.5% to 55.8%, and reduces number of stops by 69.5%, compared with the traditional DLT.

  14. Time to turn the other cheek? The influence of left and right poses on perceptions of academic specialisation.

    PubMed

    Lindell, Annukka K; Savill, Nicola J

    2010-11-01

    The human face expresses emotion asymmetrically. Whereas the left cheek is more emotionally expressive, the right cheek appears more impassive, hence the appropriate cheek to put forward depends on the circumstance. Nicholls, Clode, Wood, and Wood (1999, Proceedings of the Royal Society (Section B), 266, 1517-1522) demonstrated that people posing for family portraits offer the left cheek, whereas those posing as a Royal Society scientist favour the right. Given that the stereotypical representations of members of different academic disciplines differ markedly in their perceived openness and emotionality (e.g., "serious" scientist vs. "creative" writer), we reasoned that people may use cheek as a cue when determining a model's area of academic interest. Two hundred and nine participants (M=90, F=119) viewed pairs of left and right cheek poses, and made a forced-choice decision indicating which image depicted a Chemistry, Psychology or English student. Half the images were mirror-reversed to control for perceptual and aesthetic biases. Consistent with prediction, participants were more likely to select left cheek images for English students, and right cheek images for Chemistry students, irrespective of image orientation. The results confirm that determining the best cheek to put forward depends on your academic expertise: an impassive right cheek suggests hard science, whereas an emotive left cheek implies the arts. Psychology produced no left or right bias, consistent with its position as a discipline perpetually straddling the boundary between art and science.

  15. Pedestrian Safety Treatments for Signalized Intersections : Training Course Development

    DOT National Transportation Integrated Search

    2017-11-01

    When drivers make left turns during a permissive turn phase, they must yield to pedestrians as well as oncoming through vehicles. Left-turning drivers sometimes overlook pedestrians in the crosswalk while watching the opposing intersection approach. ...

  16. Long-period gratings in photonic crystal fibers operating near the phase-matching turning point for evanescent chemical and biochemical sensing

    NASA Astrophysics Data System (ADS)

    Kanka, Jiri

    2012-06-01

    Fiber-optic long-period grating (LPG) operating near the dispersion turning point in its phase matching curve (PMC), referred to as a Turn Around Point (TAP) LPG, is known to be extremely sensitive to external parameters. Moreover, in a TAP LPG the phase matching condition can be almost satisfied over large spectral range, yielding a broadband LPG operation. TAP LPGs have been investigated, namely for use as broadband mode convertors and biosensors. So far TAP LPGs have been realized in specially designed or post-processed conventional fibers, not yet in PCFs, which allow a great degree of freedom in engineering the fiber's dispersion properties through the control of the PCF structural parameters. We have developed the design optimization technique for TAP PCF LPGs employing the finite element method for PCF modal analysis in a combination with the Nelder-Mead simplex method for minimizing the objective function based on target-specific PCF properties. Using this tool we have designed TAP PCF LPGs for specified wavelength ranges and refractive indices of medium in the air holes. Possible TAP PCF-LPG operational regimes - dual-resonance, broadband mode conversion and transmitted intensity-based operation - will be demonstrated numerically. Potential and limitations of TAP PCF-LPGs for evanescent chemical and biochemical sensing will be assessed.

  17. Evaluating the Operational Features of an Unconventional Dual-Bay U-Turn Design for Intersections

    PubMed Central

    Xiang, Yun; Li, Zhibin; Wang, Wei; Chen, Jingxu; Wang, Hao; Li, Ye

    2016-01-01

    Median U-turn intersection treatment (MUTIT) has been considered an alternative measure to reduce congestion and traffic conflict at intersection areas. The MUTIT is sometimes difficult to implement in the field because it requires wide median on arterials for U-turn vehicles. The objective of this study is to introduce an unconventional U-turn treatment (UUT) for intersections which requires less median space but is also effective. The UUT has a dual-bay design with different turning radiuses for small and large vehicles. The VISSIM simulation model was developed to evaluate the operational features of the UUT. The model was calibrated using data collected from intersections in China. The capacity, delay and number of stops were evaluated and compared with the direct-left-turn (DLT) for the same intersections. The results showed that the UUT significantly improved the operations at intersection areas, especially when volume/capacity ratio is small, and ratio of left-turn to through traffic is small. With the UUT, the capacity is increased by 9.81% to 10.38%, vehicle delay is decreased by 18.5% to 40.1%, and number of stops is decreased by 23.19% to 36.62%, when volume/capacity ratio is less than 0.50. The study also found that traffic efficiency could be further improved when the UUT is designed in conjunction with signal control. In the case, the UUT plus signalized control increases the capacity by 25% to 26.02%, decreases vehicle delay by 50.5% to 55.8%, and reduces number of stops by 69.5%, compared with the traditional DLT. PMID:27467127

  18. A Driving Simulator Evaluation of Red Arrows and Flashing Yellow Arrows in Right-Turn Applications : Establishing the Foundation for Future Research

    DOT National Transportation Integrated Search

    2017-11-01

    Driver understanding of flashing yellow arrow (FYA) indications for left turns has been studied extensively; however, the use of FYA for right-turn applications is an area that needs to be better understood through evaluations focused on actual drive...

  19. Wolff-Parkinson-White syndrome type B and left bundle-branch block: electrophysiologic and radionuclide study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rakovec, P.; Kranjec, I.; Fettich, J.J.

    1985-01-01

    Coinciding left bundle-branch block and Wolff-Parkinson-White syndrome type B, a very rare electrocardiographic occurrence, was found in a patient with dilated cardiomyopathy. Electrophysiologic study revealed eccentric retrograde atrial activation during ventricular pacing, suggesting right-sided accessory pathway. At programmed atrial pacing, effective refractory period of the accessory pathway was 310 ms; at shorter pacing coupling intervals, normal atrioventricular conduction with left bundle-branch block was seen. Left bundle-branch block was seen also with His bundle pacing. Radionuclide phase imaging demonstrated right ventricular phase advance and left ventricular phase delay; both right and left ventricular phase images revealed broad phase distribution histograms. Combinedmore » electrophysiologic and radionuclide investigations are useful to disclose complex conduction abnormalities and their mechanical correlates.« less

  20. Right-handed double-helix ultrashort DNA yields chiral nematic phases with both right- and left-handed director twist

    PubMed Central

    Zanchetta, Giuliano; Giavazzi, Fabio; Nakata, Michi; Buscaglia, Marco; Cerbino, Roberto; Clark, Noel A.; Bellini, Tommaso

    2010-01-01

    Concentrated solutions of duplex-forming DNA oligomers organize into various mesophases among which is the nematic (N∗), which exhibits a macroscopic chiral helical precession of molecular orientation because of the chirality of the DNA molecule. Using a quantitative analysis of the transmission spectra in polarized optical microscopy, we have determined the handedness and pitch of this chiral nematic helix for a large number of sequences ranging from 8 to 20 bases. The B-DNA molecule exhibits a right-handed molecular double-helix structure that, for long molecules, always yields N∗ phases with left-handed pitch in the μm range. We report here that ultrashort oligomeric duplexes show an extremely diverse behavior, with both left- and right-handed N∗ helices and pitches ranging from macroscopic down to 0.3 μm. The behavior depends on the length and the sequence of the oligomers, and on the nature of the end-to-end interactions between helices. In particular, the N∗ handedness strongly correlates with the oligomer length and concentration. Right-handed phases are found only for oligomers shorter than 14 base pairs, and for the sequences having the transition to the N∗ phase at concentration larger than 620 mg/mL. Our findings indicate that in short DNA, the intermolecular double-helical interactions switch the preferred liquid crystal handedness when the columns of stacked duplexes are forced at high concentrations to separations comparable to the DNA double-helix pitch, a regime still to be theoretically described. PMID:20876125

  1. Ribbon structure stabilized by C10 and C12 turns in αγ hybrid peptide.

    PubMed

    Wani, Naiem Ahmad; Kant, Rajni; Gupta, Vivek Kumar; Aravinda, Subrayashastry; Rai, Rajkishor

    2016-04-01

    The present study describes the synthesis and crystallographic analysis of αγ hybrid peptides, Boc-Gpn-L-Pro-NHMe (1), Boc-Aib-Gpn-L-Pro-NHMe (2), and Boc-L-Pro-Aib-Gpn-L-Pro-NHMe (3). Peptides 1 and 2 adopt expanded 12-membered (C12 ) helical turn over γα segment. Peptide 3 promotes the ribbon structure stabilized by type II β-turn (C10 ) followed by the expanded C12 helical γα turn. Both right-handed and left-handed helical conformations for Aib residue are observed in peptides 2 and 3, respectively. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  2. Lattice Calibration with Turn-By-Turn BPM Data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huang, Xiaobiao; /SLAC; Sebek, James

    2012-07-02

    Turn-by-turn beam position monitor (BPM) data from multiple BPMs are fitted with a tracking code to calibrate magnet strengths in a manner similar to the well known LOCO code. Simulation shows that this turn-by-turn method can be a quick and efficient way for optics calibration. The method is applicable to both linacs and ring accelerators. Experimental results for a section of the SPEAR3 ring is also shown.

  3. Training strategies and materials.

    DOT National Transportation Integrated Search

    2008-08-01

    TxDOT project 0-5840 Development of Left-Turn Operations Guidelines at Signalized Intersections has developed : guidelines for recommending the most appropriate left-turn phasing treatments at signalized intersections by investigating all : asp...

  4. Differences of Ballet Turns ("Pirouette") Performance between Experienced and Novice Ballet Dancers

    ERIC Educational Resources Information Center

    Lin, Chia-Wei; Chen, Shing-Jye; Su, Fong-Chin; Wu, Hong-Wen; Lin, Cheng-Feng

    2014-01-01

    Purpose: This study investigated the different postural control strategies exhibited by experienced and novice dancers in ballet turns ("pirouettes"). Method: Thirteen novice and 13 experienced dancers performed ballet turns with dominant-leg support. The peak push force was measured in the double-leg support phase. The inclination…

  5. The Clinical Significance Of Freezing While Turning in Parkinson’s Disease

    PubMed Central

    Mancini, Martina; Smulders, Katrijn; Cohen, Rajal G.; Horak, Fay B.; Giladi, Nir; Nutt, John G

    2016-01-01

    Freezing of gait (FoG) in people with Parkinson’s disease (PD) is an environmentally sensitive, intermittent problem that occurs most often during turning. FoG is difficult for clinicians to evaluate and treat because it can be difficult to elicit during a clinical visit. Here, we aimedto develop a clinically valid objective measure of freezing severity during a 2-minute 360 degrees turning-in-place. Twenty-eight subjects with PD (16 freezers, FoG+, and 12 nonfreezers, FoG−) in the “off” state and 14 healthy control subjects were tested. Subjects wore 3 inertial sensors (one on each shin and one on the waist) while 1) turning in place for 2 minutes (alternating 360 degrees to the right with 360 degrees to the left) and 2) performing an Instrumented 7m Timed Up and Go test (ITUG). Performance was videotaped, and clinical severity of FoG was independently rated by two movement disorders specialists (co-authors). Turning in place consistently resulted in FoG (13 out of 16 subjects with PD) while FoG was clinically observed in only 2 subjects with PD during the ITUG test. The Freezing Ratio during the turning test was significantly correlated with the clinical ratings (ρ=0.7, p=0.003) and with score on the new freezing of gait questionnaire (ρ=0.5, p=0.03). After correcting for symptom severity (UPDRS-III), out of the 4 objective measures of the turning test (total number of turns, average turn peak speed and average turn smoothness), only the Freezing Ratio was significantly different across groups (p=0.04). Freezing can be well quantified with body-worn inertial sensors during a 2-minute turning-in-place protocol. PMID:27956066

  6. A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Xi; Huang, Xiaobiao

    2016-08-01

    We propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. Furthermore, the fitting results are used for lattice correction. Our method has been successfully demonstrated on the NSLS-II storage ring.

  7. A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Xi; Huang, Xiaobiao

    2016-08-01

    We propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. The fitting results are used for lattice correction. The method has been successfully demonstrated on the NSLS-II storage ring.

  8. Required coefficient of friction in the anteroposterior and mediolateral direction during turning at different walking speeds

    PubMed Central

    Yamaguchi, Takeshi; Suzuki, Akito; Hokkirigawa, Kazuo

    2017-01-01

    This study investigated the required coefficient of friction (RCOF) and the tangent of center of mass (COM)–center of pressure (COP) angle in the mediolateral (ML) and anteroposterior (AP) directions during turning at different walking speeds. Sixteen healthy young adults (8 males and 8 females) participated in this study. The participants were instructed to conduct trials of straight walking and 90° step and spin turns to the right at each of three self-selected speeds (slow, normal, and fast). The ML and AP directions during turning gait were defined using the orientation of the pelvis to construct a body-fixed reference frame. The RCOF values and COM–COP angle tangent in the ML direction during turning at weight acceptance phase were higher than those during straight walking, and those values increased with increasing walking speed. The ML component of the RCOF and COM–COP tangent values during weight acceptance for step turns were higher than those for spin turns. The mean centripetal force during turning tended to increase with an increase in walking speed and had a strong positive correlation with the RCOF values in the ML direction (R = 0.97 during the weight acceptance phase; R = 0.95 during the push-off phase). Therefore, turning, particularly step turn, is likely to cause lateral slip at weight acceptance because of the increased centripetal force compared with straight walking. Future work should test at-risk population and compare with the present results. PMID:28640853

  9. Required coefficient of friction in the anteroposterior and mediolateral direction during turning at different walking speeds.

    PubMed

    Yamaguchi, Takeshi; Suzuki, Akito; Hokkirigawa, Kazuo

    2017-01-01

    This study investigated the required coefficient of friction (RCOF) and the tangent of center of mass (COM)-center of pressure (COP) angle in the mediolateral (ML) and anteroposterior (AP) directions during turning at different walking speeds. Sixteen healthy young adults (8 males and 8 females) participated in this study. The participants were instructed to conduct trials of straight walking and 90° step and spin turns to the right at each of three self-selected speeds (slow, normal, and fast). The ML and AP directions during turning gait were defined using the orientation of the pelvis to construct a body-fixed reference frame. The RCOF values and COM-COP angle tangent in the ML direction during turning at weight acceptance phase were higher than those during straight walking, and those values increased with increasing walking speed. The ML component of the RCOF and COM-COP tangent values during weight acceptance for step turns were higher than those for spin turns. The mean centripetal force during turning tended to increase with an increase in walking speed and had a strong positive correlation with the RCOF values in the ML direction (R = 0.97 during the weight acceptance phase; R = 0.95 during the push-off phase). Therefore, turning, particularly step turn, is likely to cause lateral slip at weight acceptance because of the increased centripetal force compared with straight walking. Future work should test at-risk population and compare with the present results.

  10. [Abnormal head turn in a patient with Brown's syndrome].

    PubMed

    van Waveren, M; Krzizok, T; Besch, D

    2008-08-01

    We report on an eight-year-old boy, who was presented in our clinic because of head turn. The cause of the tortecollis (ocular or general) in this case was and still cannot be explained. Only by applying extensive prism adaptation tests it was possible to prove the ocular character of the head turn. An eight-year-old boy with Brown's syndrome was referred to us because of a head tilt to the left side. Six months previously surgery on the M. obl. superior of the right eye was performed in another clinic. No improvement of the head tilt could be observed after the operation. In addition, an exotropia became decompensated. Under a 3-day occlusion of one eye, no change of the head turn and the squint could be measured. No other cause of the head turn could be found by an orthopaedist and a paediatrist. Under a prism of 20 cm/m basis in and 10 cm/m basis against the positive vertical deviation, the head tilt decreased, so that we decided to do a second surgery. The head tilting had not resumed at one year after the surgery. Although the initial diagnostic findings ruled out an ocular cause, it was possible to lessen the head tilting with the aid of the prism adaptation test. This case study emphasises the usefulness of a prism adaptation test of several days duration in order to validate an ocular cause of head turn and to determine an adequate indication for surgery.

  11. Do Right- and Left-Handed Monkeys Differ on Cognitive Measures?

    NASA Technical Reports Server (NTRS)

    Hopkins, William D.; Washburn, David A.

    1994-01-01

    Twelve left- and 14 right-handed monkeys were compared on 6 measures of cognitive performance (2 maze-solving tasks, matching-to-sample, delayed matching-to-sample, delayed response using spatial cues, and delayed response using form cues). The dependent variable was trials-to-training criterion for each of the 6 tasks. Significant differences were found between left- and right-handed monkeys on the 2 versions of the delayed response task. Right-handed monkeys reached criterion significantly faster on the form cue version of the task, whereas left-handed monkeys reached criterion significantly faster on delayed response for spatial position (p less than .05). The results suggest that sensitive hand preference measures of laterality can reveal differences in cognitive performance, which in turn may reflect underlying laterality in functional organization of the nervous system.

  12. Improved pedestrian safety at signalized intersections operating the flashing yellow arrow.

    DOT National Transportation Integrated Search

    2013-04-01

    In some jurisdictions, protected left-turn phasing has been replaced with the flashing yellow arrow (FYA) for : protected/permissive left turns (PPLTs) to reduce delay. However, it is important to have a thorough understanding of the : conflict betwe...

  13. A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Xi; Huang, Xiaobiao

    2016-05-13

    Here, we propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. The fitting results are used for lattice correction. Finally, the method has been successfully demonstrated on the NSLS-II storage ring.

  14. High salt solution structure of a left-handed RNA double helix

    PubMed Central

    Popenda, Mariusz; Milecki, Jan; Adamiak, Ryszard W.

    2004-01-01

    Right-handed RNA duplexes of (CG)n sequence undergo salt-induced helicity reversal, forming left-handed RNA double helices (Z-RNA). In contrast to the thoroughly studied Z-DNA, no Z-RNA structure of natural origin is known. Here we report the NMR structure of a half-turn, left-handed RNA helix (CGCGCG)2 determined in 6 M NaClO4. This is the first nucleic acid motif determined at such high salt. Sequential assignments of non-exchangeable proton resonances of the Z-form were based on the hitherto unreported NOE connectivity path [H6(n)-H5′/H5″(n)-H8(n+1)-H1′(n+1)-H6(n+2)] found for left-handed helices. Z-RNA structure shows several conformational features significantly different from Z-DNA. Intra-strand but no inter-strand base stacking was observed for both CpG and GpC steps. Helical twist angles for CpG steps have small positive values (4–7°), whereas GpC steps have large negative values (−61°). In the full-turn model of Z-RNA (12.4 bp per turn), base pairs are much closer to the helix axis than in Z-DNA, thus both the very deep, narrow minor groove with buried cytidine 2′-OH groups, and the major groove are well defined. The 2′-OH group of cytidines plays a crucial role in the Z-RNA structure and its formation; 2′-O-methylation of cytidine, but not of guanosine residues prohibits A to Z helicity reversal. PMID:15292450

  15. A real-time traffic control method for the intersection with pre-signals under the phase swap sorting strategy

    PubMed Central

    Bie, Yiming; Wang, Yinhai

    2017-01-01

    To deal with the conflicts between left-turn and through traffic streams and increase the discharge capacity, this paper addresses the pre-signal which is implemented at a signalized intersection. Such an intersection with pre-signal is termed as a tandem intersection. For the tandem intersection, phase swap sorting strategy is deemed as the most effective phasing scheme in view of some exclusive merits, such as easier compliance of drivers, and shorter sorting area. However, a major limitation of the phase swap sorting strategy is not considered in previous studies: if one or more vehicle is left at the sorting area after the signal light turns to red, the capacity of the approach would be dramatically dropped. Besides, previous signal control studies deal with a fixed timing plan that is not adaptive with the fluctuation of traffic flows. Therefore, to cope with these two gaps, this paper firstly takes an in-depth analysis of the traffic flow operations at the tandem intersection. Secondly, three groups of loop detectors are placed to obtain the real-time vehicle information for adaptive signalization. The lane selection behavior in the sorting area is considered to set the green time for intersection signals. With the objective of minimizing the vehicle delay, the signal control parameters are then optimized based on a dynamic programming method. Finally, numerical experiments show that average vehicle delay and maximum queue length can be reduced under all scenarios. PMID:28531198

  16. A real-time traffic control method for the intersection with pre-signals under the phase swap sorting strategy.

    PubMed

    Bie, Yiming; Liu, Zhiyuan; Wang, Yinhai

    2017-01-01

    To deal with the conflicts between left-turn and through traffic streams and increase the discharge capacity, this paper addresses the pre-signal which is implemented at a signalized intersection. Such an intersection with pre-signal is termed as a tandem intersection. For the tandem intersection, phase swap sorting strategy is deemed as the most effective phasing scheme in view of some exclusive merits, such as easier compliance of drivers, and shorter sorting area. However, a major limitation of the phase swap sorting strategy is not considered in previous studies: if one or more vehicle is left at the sorting area after the signal light turns to red, the capacity of the approach would be dramatically dropped. Besides, previous signal control studies deal with a fixed timing plan that is not adaptive with the fluctuation of traffic flows. Therefore, to cope with these two gaps, this paper firstly takes an in-depth analysis of the traffic flow operations at the tandem intersection. Secondly, three groups of loop detectors are placed to obtain the real-time vehicle information for adaptive signalization. The lane selection behavior in the sorting area is considered to set the green time for intersection signals. With the objective of minimizing the vehicle delay, the signal control parameters are then optimized based on a dynamic programming method. Finally, numerical experiments show that average vehicle delay and maximum queue length can be reduced under all scenarios.

  17. Modulation of left primary motor cortex excitability after bimanual training and intermittent theta burst stimulation to left dorsal premotor cortex.

    PubMed

    Neva, Jason L; Vesia, Michael; Singh, Amaya M; Staines, W Richard

    2014-03-15

    Bimanual visuomotor movement training (BMT) enhances the excitability of human preparatory premotor and primary motor (M1) cortices compared to unimanual movement. This occurs when BMT involves mirror symmetrical movements of both upper-limbs (in-phase) but not with non-symmetrical movements (anti-phase). The neural mechanisms mediating the effect of BMT is unclear, but may involve interhemispheric connections between homologous M1 representations as well as the dorsal premotor cortices (PMd). The purpose of this study is to assess how intermittent theta burst stimulation (iTBS) of the left PMd affects left M1 excitability, and the possible combined effects of iTBS to left PMd applied before a single session of BMT. Left M1 excitability was quantified using transcranial magnetic stimulation (TMS) in terms of both the amplitudes and spatial extent of motor evoked potentials (MEPs) for the extensor carpi radialis (ECR) before and multiple time points following (1) BMT, (2) iTBS to left PMd or (3) iTBS to left PMd and BMT. Although there was not a greater increase in either specific measure of M1 excitability due to the combination of the interventions, iTBS applied before BMT showed that both the spatial extent and global MEP amplitude for the ECR became larger in parallel, whereas the spatial extent was enhanced with BMT alone and global MEP amplitude was enhanced with iTBS to left PMd alone. These results suggest that the modulation of rapid functional M1 excitability associated with BMT and iTBS of the left PMd could operate under related early markers of neuro-plastic mechanisms, which may be expressed in concurrent and distinct patterns of M1 excitability. Critically, this work may guide rehabilitation training and stimulation techniques that modulate cortical excitability after brain injury. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Turn-Taking, Turn-Giving, and Alzheimer's Disease.

    ERIC Educational Resources Information Center

    Sabat, Steven R.

    1991-01-01

    Analysis of a conversation with an Alzheimer's disease sufferer with word-finding problems revealed that social context, speaker characteristics, and awareness of the other speaker's perspective governed such conversational aspects of turn taking and turn giving, which allowed full development of both speakers' personas. (23 references) (CB)

  19. Micro-simulation of vehicle conflicts involving right-turn vehicles at signalized intersections based on cellular automata.

    PubMed

    Chai, C; Wong, Y D

    2014-02-01

    At intersection, vehicles coming from different directions conflict with each other. Improper geometric design and signal settings at signalized intersection will increase occurrence of conflicts between road users and results in a reduction of the safety level. This study established a cellular automata (CA) model to simulate vehicular interactions involving right-turn vehicles (as similar to left-turn vehicles in US). Through various simulation scenarios for four case cross-intersections, the relationships between conflict occurrences involving right-turn vehicles with traffic volume and right-turn movement control strategies are analyzed. Impacts of traffic volume, permissive right-turn compared to red-amber-green (RAG) arrow, shared straight-through and right-turn lane as well as signal setting are estimated from simulation results. The simulation model is found to be able to provide reasonable assessment of conflicts through comparison of existed simulation approach and observed accidents. Through the proposed approach, prediction models for occurrences and severity of vehicle conflicts can be developed for various geometric layouts and traffic control strategies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Spatiotemporal and Kinematic Parameters Relating to Oriented Gait and Turn Performance in Patients with Chronic Stroke

    PubMed Central

    Bonnyaud, Céline; Pradon, Didier; Vuillerme, Nicolas; Bensmail, Djamel; Roche, Nicolas

    2015-01-01

    Background The timed up and go test (TUG) is a functional test which is increasingly used to evaluate patients with stroke. The outcome measured is usually global TUG performance-time. Assessment of spatiotemporal and kinematic parameters during the Oriented gait and Turn sub-tasks of the TUG would provide a better understanding of the mechanisms underlying patients’ performance and therefore may help to guide rehabilitation. The aim of this study was thus to determine the spatiotemporal and kinematic parameters which were most related to the walking and turning sub-tasks of TUG performance in stroke patients. Methods 29 stroke patients carried out the TUG test which was recorded using an optoelectronic system in two conditions: spontaneous and standardized condition (standardized foot position and instructed to turn towards the paretic side). They also underwent a clinical assessment. Stepwise regression was used to determine the parameters most related to Oriented gait and Turn sub-tasks. Relationships between explanatory parameters of Oriented gait and Turn performance and clinical scales were evaluated using Spearman correlations. Results Step length and cadence explained 82% to 95% of the variance for the walking sub-tasks in both conditions. Percentage single support phase and contralateral swing phase (depending on the condition) respectively explained 27% and 56% of the variance during the turning sub-task in the spontaneous and standardized conditions. Discussion and Conclusion Step length, cadence, percentage of paretic single support phase and non-paretic swing phase, as well as dynamic stability were the main parameters related to TUG performance and they should be targeted in rehabilitation. PMID:26091555

  1. Spectroscopic evidence for gas-phase formation of successive beta-turns in a three-residue peptide chain.

    PubMed

    Chin, Wutharath; Compagnon, Isabelle; Dognon, Jean-Pierre; Canuel, Clélia; Piuzzi, François; Dimicoli, Iliana; von Helden, Gert; Meijer, Gerard; Mons, Michel

    2005-02-09

    We report the first gas-phase spectroscopic study of a three-residue model of a peptide chain, Ac-Phe-Gly-Gly-NH2 (Ac = acetyl), using the IR/UV double resonance technique. The existence of at least five different conformers under supersonic expansion conditions is established, most of them exhibiting rather strong intramolecular H-bonds. One of the most populated conformers, however, exhibits a different H-bonding network characterized by two weak H-bonds. Comparison of the amide A and I/II experimental data with density functional theory calculations carried out on a series of selected conformations enables us to assign this conformer to two successive beta-turns along the peptide chain, the two H-bonds being of C10 type, i.e., each of them closing a 10-atom ring in the molecule. The corresponding form is found to be more stable than the 310 helix secondary structure (not observed), presumably because of specific effects due to the glycine residues.

  2. Transparent lattice characterization with gated turn-by-turn data of diagnostic bunch train

    NASA Astrophysics Data System (ADS)

    Li, Yongjun; Cheng, Weixing; Ha, Kiman; Rainer, Robert

    2017-11-01

    Methods of characterization of a storage ring's lattice have traditionally been intrusive to routine operations. More importantly, the lattice seen by particles can drift with the beam current due to collective effects. To circumvent this, we have developed a novel approach for dynamically characterizing a storage ring's lattice that is transparent to operations. Our approach adopts a dedicated filling pattern which has a short, separate diagnostic bunch train (DBT). Through the use of a bunch-by-bunch feedback system, the DBT can be selectively excited on demand. Gated functionality of a beam position monitor system is capable of collecting turn-by-turn data of the DBT, from which the lattice can then be characterized after excitation. As the DBT comprises only about one percent of the total operational bunches, the effects of its excitation are negligible to users. This approach allows us to localize the distributed quadrupolar wakefields generated in the storage ring vacuum chamber during beam accumulation. While effectively transparent to operations, our approach enables us to dynamically control the beta beat and phase beat, and unobtrusively optimize performance of the National Synchrotron Light Source-II accelerator during routine operations.

  3. Transparent lattice characterization with gated turn-by-turn data of diagnostic bunch train

    DOE PAGES

    Li, Yongjun; Cheng, Weixing; Ha, Kiman; ...

    2017-11-21

    Methods of characterization of a storage ring's lattice have traditionally been intrusive to routine operations. More importantly, the lattice seen by particles can drift with the beam current due to collective effects. To circumvent this, we have developed a novel approach for dynamically characterizing a storage ring's lattice that is transparent to operations. Our approach adopts a dedicated filling pattern which has a short, separate Diagnostic Bunch-Train (DBT). Through the use of a bunch-by-bunch feedback system, the DBT can be selectively excited on-demand. Gated functionality of a beam position monitor system is capable of collecting turn-by-turn data of the DBT,more » from which the lattice can then be characterized after excitation. As the DBT comprises only about one percent of the total operational bunches, the effects of its excitation are negligible to users. Therefore, this approach allows us to localize the distributed quadrupolar wake fields generated in the storage ring vacuum chamber during beam accumulation. While effectively transparent to operations, our approach enables us to dynamically control the beta-beat and phase-beat, and unobtrusively optimize performance of National Synchrotron Light Source-II accelerator during routine operations.« less

  4. Evaluation of mechanical dyssynchrony and myocardial perfusion using phase analysis of gated SPECT imaging in patients with left ventricular dysfunction

    PubMed Central

    Trimble, Mark A.; Borges-Neto, Salvador; Honeycutt, Emily F.; Shaw, Linda K.; Pagnanelli, Robert; Chen, Ji; Iskandrian, Ami E.; Garcia, Ernest V.; Velazquez, Eric J.

    2010-01-01

    Background Using phase analysis of gated single photon emission computed tomography (SPECT) imaging, we examined the relation between myocardial perfusion, degree of electrical dyssynchrony, and degree of SPECT-derived mechanical dyssynchrony in patients with left ventricular (LV) dysfunction. Methods and Results We retrospectively examined 125 patients with LV dysfunction and ejection fraction of 35% or lower. Fourier analysis converts regional myocardial counts into a continuous thickening function, allowing resolution of phase of onset of myocardial thickening. The SD of LV phase distribution (phase SD) and histogram bandwidth describe LV phase dispersion as a measure of dyssynchrony. Heart failure (HF) patients with perfusion abnormalities ities have higher degrees of dyssynchrony measured by median phase SD (45.5° vs 27.7°, P < .0001) and bandwidth (117.0° vs 73.0°, P = .0006). HF patients with prolonged QRS durations have higher degrees of dyssynchrony measured by median phase SD (54.1° vs 34.7°, P < .0001) and bandwidth (136.5° vs 99.0°, P = .0005). Mild to moderate correlations exist between QRS duration and phase analysis indices of phase SD (r = 0.50) and bandwidth (r = 0.40). Mechanical dyssynchrony (phase SD >43°) was 43.2%. Conclusions HF patients with perfusion abnormalities or prolonged QRS durations QRS durations have higher degrees of mechanical dyssynchrony. Gated SPECT myocardial perfusion imaging can quantify myocardial function, perfusion, and dyssynchrony and may help in evaluating patients for cardiac resynchronization therapy. PMID:18761269

  5. Analysis of the lateral push-off in the freestyle flip turn.

    PubMed

    Araujo, Luciana; Pereira, Suzana; Gatti, Roberta; Freitas, Elinai; Jacomel, Gabriel; Roesler, Helio; Villas-Boas, Joao

    2010-09-01

    The aim of this study was to examine the contact phase during the lateral push-off in the turn of front crawl swimming to determine which biomechanical variables (maximum normalized peak force, contact time, impulse, angle of knee flexion, and total turn time within 15 m) contribute to the performance of this turn technique. Thirty-four swimmers of state, national, and international competitive standard participated in the study. For data collection, the following equipment was used: an underwater force platform, a 30-Hz VHS video camera, and a MiniDv digital camera within an underwater box. Data are expressed as descriptive statistics. Inferential analyses were performed using Pearson's correlation and multiple linear regressions. All variables studied had a significant relationship with turn performance. We conclude that a turn executed with a knee flexion angle of between 100° and 120° provides optimum peak forces to generate impulses that allow the swimmer to lose less time in the turn without the need for an excessive force application and with less energy lost.

  6. Modeling left turn queue lengths.

    DOT National Transportation Integrated Search

    2011-01-01

    This guidebook provides methodologies and procedures for using incident data collected at Texas transportation management centers (TMCs) to perform two types of analysis - evaluation/planning analysis and predictive analysis. For the evaluation/plann...

  7. Exterior, looking west, Equipment Building to left, Tower at center, ...

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

    Exterior, looking west, Equipment Building to left, Tower at center, Civil Engineering Storage Building (Building 5765) at left - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Microwave Equipment Building, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  8. Development of a phase-sensitive Fourier domain optical coherence tomography system to measure mouse organ of Corti vibrations in two cochlear turns

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ramamoorthy, Sripriya; Zhang, Yuan; Jacques, Steven

    In this study, we have developed a phase-sensitive Fourier-domain optical coherence tomography system to simultaneously measure the in vivo inner ear vibrations in the hook area and second turn of the mouse cochlea. This technical development will enable measurement of intra-cochlear distortion products at ideal locations such as the distortion product generation site and reflection site. This information is necessary to un-mix the complex mixture of intra-cochlear waves comprising the DPOAE and thus leads to the non-invasive identification of the local region of cochlear damage.

  9. Removal of single point diamond-turning marks by abrasive jet polishing.

    PubMed

    Li, Z Z; Wang, J M; Peng, X Q; Ho, L T; Yin, Z Q; Li, S Y; Cheung, C F

    2011-06-01

    Single point diamond turning (SPDT) is highly controllable and versatile in producing axially symmetric forms, non-axially-symmetric forms, microstructured surfaces, and free forms. However, the fine SPDT marks left in the surface limit its performance, and they are difficult to reduce or eliminate. It is unpractical for traditional methods to remove the fine marks without destroying their forms, especially for the aspheres and free forms. This paper introduces abrasive jet polishing (AJP) for the posttreatment of diamond-turned surfaces to remove the periodic microstructures. Samples of diamond-turned electroless nickel plated plano mirror were used in the experiments. One sample with an original surface roughness of more than 400 nm decreased to 4 nm after two iterations abrasive jet polishing; the surface roughness of another sample went from 3.7 nm to 1.4 nm after polishing. The periodic signatures on both of the samples were removed entirely after polishing. Contrastive experimental research was carried out on electroless nickel mirror with magnetorheological finishing, computer controlled optical surfacing, and AJP. The experimental results indicate that AJP is more appropriate in removing the periodic SPDT marks. Also, a figure maintaining experiment was carried out with the AJP process; the uniform polishing process shows that the AJP process can remove the periodic turning marks without destroying the original form.

  10. [Selective left mainstem bronchial intubation in the neonatal intensive care unit].

    PubMed

    Ho, Anthony M H; Flavin, Michael P; Fleming, Melinda L; Mizubuti, Glenio Bitencourt

    Selective neonatal left mainstem bronchial intubation to treat right lung disease is typically achieved with elaborate maneuvers, instrumentation and devices. This is often attributed to bronchial geometry which favors right mainstem entry of an endotracheal tube deliberately advanced beyond the carina. A neonate with severe bullous emphysema affecting the right lung required urgent non-ventilation of that lung. We achieved left mainstem bronchial intubation by turning the endotracheal tube 180° such that the Murphy's eye faced the left instead of the right, and simulated a left-handed intubation by slightly orientating the endotracheal tube such that its concavity faced the left instead of the right as in a conventional right-handed intubation. Urgent intubation of the left mainstem bronchus with an endotracheal tube can be easily achieved by recognizing that it is the position of the endotracheal tube tip and the direction of its concavity that are the chief determinants of which bronchus an endotracheal tube goes when advanced. This is important in critically ill neonates as the margin of safety and time window are small, and the absence of double-lumen tubes. Use of fiberoptic bronchoscope and blockers should be reserved as backup plans. Copyright © 2017 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  11. Genesis of a flexible turning center

    NASA Astrophysics Data System (ADS)

    Sanclemente, Paul; French, Robert D.

    GE - Aircraft Engines has designed, built, and is operating a flexible turning center for jet engine hardware. Although the plant is in the forefront of manufacturing technology development, it was intended from the start to be a production facility. So while there was much to learn from being involved in all phases of the project, meeting production schedules was, and is, key to its success. This paper reviews the early history of the project and ends with a view of its recent production status.

  12. Differences of ballet turns (pirouette) performance between experienced and novice ballet dancers.

    PubMed

    Lin, Chia-Wei; Chen, Shing-Jye; Su, Fong-Chin; Wu, Hong-Wen; Lin, Cheng-Feng

    2014-09-01

    This study investigated the different postural control strategies exhibited by experienced and novice dancers in ballet turns (pirouettes). Thirteen novice and 13 experienced dancers performed ballet turns with dominant-leg support. The peak push force was measured in the double-leg support phase. The inclination angles of rotation axis with respect to vertical axis were calculated in the early single-leg support phase as well as the initiation sequence of ankle, knee, and hip joints on the supporting leg. Moreover, the anchoring index of the head was computed in the transverse plane during turning. The novice dancers applied a greater push force, an increased inclination angle of rotation axis, and an insufficient proximal-to-distal extension sequence pattern. The novice dancers also had a smaller head-anchoring index compared with experienced dancers, which meant novice dancers were not using a space target as a stability reference. A poorer performance in novice dancers could result from higher push force in propulsion, lack of a "proximal-to-distal extension sequence" pattern, and lack of visual spotting for postural stability. Training on sequential initiation of lower-extremity joints and rehearsal of visual spotting are essential for novice dancers to obtain better performance on ballet turns.

  13. Turning assistive machines into assistive robots

    NASA Astrophysics Data System (ADS)

    Argall, Brenna D.

    2015-01-01

    For decades, the potential for automation in particular, in the form of smart wheelchairs to aid those with motor, or cognitive, impairments has been recognized. It is a paradox that often the more severe a person's motor impairment, the more challenging it is for them to operate the very assistive machines which might enhance their quality of life. A primary aim of my lab is to address this confound by incorporating robotics autonomy and intelligence into assistive machines turning the machine into a kind of robot, and offloading some of the control burden from the user. Robots already synthetically sense, act in and reason about the world, and these technologies can be leveraged to help bridge the gap left by sensory, motor or cognitive impairments in the users of assistive machines. This paper overviews some of the ongoing projects in my lab, which strives to advance human ability through robotics autonomy.

  14. Turning the School Around: The Transformation of a Secondary School from Underperforming to Highly Achieving

    ERIC Educational Resources Information Center

    Branch, Cynthia Monroe

    2013-01-01

    The No Child Left Behind Act of 2001 put a focus on each child in a school being proficient. Since 1957 when Sputnik was launched, the United States has been attempting to improve its schools. The existing literature has a gap as to how to turn around an underperforming school in a fairly short period of time. A qualitative case study methodology…

  15. The performance of the standard rate turn (SRT) by student naval helicopter pilots.

    PubMed

    Chapman, F; Temme, L A; Still, D L

    2001-04-01

    During flight training, student naval helicopter pilots learn the use of flight instruments through a prescribed series of simulator training events. The training simulator is a 6-degrees-of-freedom, motion-based, high-fidelity instrument trainer. From the final basic instrument simulator flights of student pilots, we selected for evaluation and analysis their performance of the Standard Rate Turn (SRT), a routine flight maneuver. The performance of the SRT was scored with air speed, altitude and heading average error from target values and standard deviations. These average errors and standard deviations were used in a Multiple Analysis of Variance (MANOVA) to evaluate the effects of three independent variables: 1) direction of turn (left vs. right), 2) degree of turn (180 vs. 360 degrees); and 3) segment of turn (roll-in, first 30 s, last 30 s, and roll-out of turn). Only the main effects of the three independent variables were significant; there were no significant interactions. This result greatly reduces the number of different conditions that should be scored separately for the evaluation of SRT performance. The results also showed that the magnitude of the heading and altitude errors at the beginning of the SRT correlated with the magnitude of the heading and altitude errors throughout the turn. This result suggests that for the turn to be well executed, it is important for it to begin with little error in these two response parameters. The observations reported here should be considered when establishing SRT performance norms and comparing student scores. Furthermore, it seems easier for pilots to maintain good performance than to correct poor performance.

  16. Emotional memory retrieval. rTMS stimulation on left DLPFC increases the positive memories.

    PubMed

    Balconi, Michela; Ferrari, Chiara

    2012-09-01

    A suggestive hypothesis proposed that the lateral prefrontal cortex (LPFC) may be identified as the site of emotion-memory integration, since it was shown to be sensitive to the encoding and retrieval of emotional content. In the present research we explored the role of the dorsolateral prefrontal cortex (DLPFC) in memory retrieval of positive vs. negative emotional stimuli. This effect was analyzed by using an rTMS paradigm that induced a cortical activation of the left DLPFC. Subjects were required to perform a task consisting of two experimental phases: an encoding phase, where some lists composed by positive and negative emotional words were presented to the subjects; a retrieval phase, where the old stimuli and the new stimuli were presented for a recognition performance. The rTMS stimulation was provided during the retrieval phase over the left DLPFC. We found that the rTMS stimulation over this area affects the memory retrieval of positive emotional material, with higher memory efficiency (reduced RTs). This result suggested that left DLPFC activation promotes the memory retrieval of emotional information. Secondly, the valence model of emotional cue processing may explain decreasing of RTs, by pointing out the distinct role the left hemisphere has in positive emotional cue processing.

  17. Causal Role of Motor Simulation in Turn-Taking Behavior.

    PubMed

    Hadley, Lauren V; Novembre, Giacomo; Keller, Peter E; Pickering, Martin J

    2015-12-16

    Overlap between sensory and motor representations has been documented for a range of human actions, from grasping (Rizzolatti et al., 1996b) to playing a musical instrument (Novembre and Keller, 2014). Such overlap suggests that individuals use motor simulation to predict the outcome of observed actions (Wolpert, 1997). Here we investigate motor simulation as a basis of human communication. Using a musical turn-taking task, we show that pianists call on motor representations of their partner's part to predict when to come in for their own turn. Pianists played alternating solos with a videoed partner, and double-pulse transcranial magnetic stimulation was applied around the turn-switch to temporarily disrupt processing in two cortical regions implicated previously in different forms of motor simulation: (1) the dorsal premotor cortex (dPMC), associated with automatic motor resonance during passive observation of hand actions, especially when the actions are familiar (Lahav et al., 2007); and (2) the supplementary motor area (SMA), involved in active motor imagery, especially when the actions are familiar (Baumann et al., 2007). Stimulation of the right dPMC decreased the temporal accuracy of pianists' (right-hand) entries relative to sham when the partner's (left-hand) part had been rehearsed previously. This effect did not occur for dPMC stimulation without rehearsal or for SMA stimulation. These findings support the role of the dPMC in predicting the time course of observed actions via resonance-based motor simulation during turn-taking. Because turn-taking spans multiple modes of human interaction, we suggest that simulation is a foundational mechanism underlying the temporal dynamics of joint action. Even during passive observation, seeing or hearing somebody execute an action from within our repertoire activates motor cortices of our brain. But what is the functional relevance of such "motor simulation"? By combining a musical duet task with a real

  18. Rhynchophylline from Uncaria rhynchophylla functionally turns delayed rectifiers into A-Type K+ channels.

    PubMed

    Chou, Chun-Hsiao; Gong, Chi-Li; Chao, Chia-Chia; Lin, Chia-Huei; Kwan, Chiu-Yin; Hsieh, Ching-Liang; Leung, Yuk-Man

    2009-05-22

    Rhynchophylline (1), a neuroprotective agent isolated from the traditional Chinese medicinal herb Uncaria rhynchophylla, was shown to affect voltage-gated K(+) (Kv) channel slow inactivation in mouse neuroblastoma N2A cells. Extracellular 1 (30 microM) accelerated the slow decay of Kv currents and shifted the steady-state inactivation curve to the left. Intracellular dialysis of 1 did not accelerate the slow current decay, suggesting that this compound acts extracellularly. In addition, the percent blockage of Kv currents by this substance was independent of the degree of depolarization and the intracellular K(+) concentration. Therefore, 1 did not appear to directly block the outer channel pore, with the results obtained suggesting that it drastically accelerated Kv channel slow inactivation. Interestingly, 1 also shifted the activation curve to the left. This alkaloid also strongly accelerated slow inactivation and caused a left shift of the activation curve of Kv1.2 channels heterologously expressed in HEK293 cells. Thus, this compound functionally turned delayed rectifiers into A-type K(+) channels.

  19. Turn Basin Construction

    NASA Image and Video Library

    2017-06-14

    Modifications are underway at the Launch Complex 39 turn basin wharf at NASA's Kennedy Space Center in Florida to prepare for the arrival of the agency's massive Space Launch System (SLS) core booster aboard the barge Pegasus. Construction workers with Southeast Cherokee Construction Inc. work to shore up the turn basin area. A crane will be used to lift up precast concrete poles and position them to be driven to a depth of about 70 feet into the bedrock below the water around the turn basin. The upgrades are necessary to accommodate the 300,000-pound core booster aboard the modified Pegasus barge. The Ground Systems Development and Operations Program is overseeing the upgrades to the turn basin wharf.

  20. Mimicry by asx- and ST-turns of the four main types of beta-turn in proteins.

    PubMed

    Duddy, William J; Nissink, J Willem M; Allen, Frank H; Milner-White, E James

    2004-11-01

    Hydrogen-bonded beta-turns in proteins occur in four categories: type I (the most common), type II, type II', and type I'. Asx-turns resemble beta-turns, in that both have an NH. . .OC hydrogen bond forming a ring of 10 atoms. Serine and threonine side chains also commonly form hydrogen-bonded turns, here called ST-turns. Asx-turns and ST-turns can be categorized into four classes, based on side chain rotamers and the conformation of the central turn residue, which are geometrically equivalent to the four types of beta-turns. We propose asx- and ST-turns be named using the type I, II, I', and II' beta-turn nomenclature. Using this, the frequency of occurrence of both asx- and ST-turns is: type II' > type I > type II > type I', whereas for beta-turns it is type I > type II > type I' > type II'. Almost all type II asx-turns occur as a recently described three residue feature named an asx-nest.

  1. Mimicry by asx- and ST-turns of the four main types of β-turn in proteins

    PubMed Central

    Duddy, William J.; Nissink, J. Willem M.; Allen, Frank H.; Milner-White, E. James

    2004-01-01

    Hydrogen-bonded β-turns in proteins occur in four categories: type I (the most common), type II, type II’, and type I’. Asx-turns resemble β-turns, in that both have an NH. . .OC hydrogen bond forming a ring of 10 atoms. Serine and threonine side chains also commonly form hydrogen-bonded turns, here called ST-turns. Asx-turns and ST-turns can be categorized into four classes, based on side chain rotamers and the conformation of the central turn residue, which are geometrically equivalent to the four types of β-turns. We propose asx- and ST-turns be named using the type I, II, I’, and II’ β-turn nomenclature. Using this, the frequency of occurrence of both asx- and ST-turns is: type II’ > type I > type II > type I’, whereas for β-turns it is type I > type II > type I’ > type II’. Almost all type II asx-turns occur as a recently described three residue feature named an asx-nest. PMID:15459339

  2. Validation of high temporal resolution spiral phase velocity mapping of temporal patterns of left and right coronary artery blood flow against Doppler guidewire.

    PubMed

    Keegan, Jennifer; Raphael, Claire E; Parker, Kim; Simpson, Robin M; Strain, Stephen; de Silva, Ranil; Di Mario, Carlo; Collinson, Julian; Stables, Rod H; Wage, Ricardo; Drivas, Peter; Sugathapala, Malindie; Prasad, Sanjay K; Firmin, David N

    2015-10-02

    Temporal patterns of coronary blood flow velocity can provide important information on disease state and are currently assessed invasively using a Doppler guidewire. A non-invasive alternative would be beneficial as it would allow study of a wider patient population and serial scanning. A retrospectively-gated breath-hold spiral phase velocity mapping sequence (TR 19 ms) was developed at 3 Tesla. Velocity maps were acquired in 8 proximal right and 15 proximal left coronary arteries of 18 subjects who had previously had a Doppler guidewire study at the time of coronary angiography. Cardiovascular magnetic resonance (CMR) velocity-time curves were processed semi-automatically and compared with corresponding invasive Doppler data. When corrected for differences in heart rate between the two studies, CMR mean velocity through the cardiac cycle, peak systolic velocity (PSV) and peak diastolic velocity (PDV) were approximately 40 % of the peak Doppler values with a moderate - good linear relationship between the two techniques (R(2): 0.57, 0.64 and 0.79 respectively). CMR values of PDV/PSV showed a strong linear relationship with Doppler values with a slope close to unity (0.89 and 0.90 for right and left arteries respectively). In individual vessels, plots of CMR velocities at all cardiac phases against corresponding Doppler velocities showed a consistent linear relationship between the two with high R(2) values (mean +/-SD: 0.79 +/-.13). High temporal resolution breath-hold spiral phase velocity mapping underestimates absolute values of coronary flow velocity but allows accurate assessment of the temporal patterns of blood flow.

  3. Age-related modifications in steering behaviour: effects of base-of-support constraints at the turn point.

    PubMed

    Paquette, Maxime R; Fuller, Jason R; Adkin, Allan L; Vallis, Lori Ann

    2008-09-01

    This study investigated the effects of altering the base of support (BOS) at the turn point on anticipatory locomotor adjustments during voluntary changes in travel direction in healthy young and older adults. Participants were required to walk at their preferred pace along a 3-m straight travel path and continue to walk straight ahead or turn 40 degrees to the left or right for an additional 2-m. The starting foot and occasionally the gait starting point were adjusted so that participants had to execute the turn using a cross-over step with a narrow BOS or a lead-out step with a wide BOS. Spatial and temporal gait variables, magnitudes of angular segmental movement, and timing and sequencing of body segment reorientation were similar despite executing the turn with a narrow or wide BOS. A narrow BOS during turning generated an increased step width in the step prior to the turn for both young and older adults. Age-related changes when turning included reduced step velocity and step length for older compared to young adults. Age-related changes in the timing and sequencing of body segment reorientation prior to the turn point were also observed. A reduction in walking speed and an increase in step width just prior to the turn, combined with a delay in motion of the center of mass suggests that older adults used a more cautious combined foot placement and hip strategy to execute changes in travel direction compared to young adults. The results of this study provide insight into mobility constraints during a common locomotor task in older adults.

  4. Cerberus-Nodal-Lefty-Pitx signaling cascade controls left-right asymmetry in amphioxus.

    PubMed

    Li, Guang; Liu, Xian; Xing, Chaofan; Zhang, Huayang; Shimeld, Sebastian M; Wang, Yiquan

    2017-04-04

    Many bilaterally symmetrical animals develop genetically programmed left-right asymmetries. In vertebrates, this process is under the control of Nodal signaling, which is restricted to the left side by Nodal antagonists Cerberus and Lefty. Amphioxus, the earliest diverging chordate lineage, has profound left-right asymmetry as a larva. We show that Cerberus , Nodal , Lefty , and their target transcription factor Pitx are sequentially activated in amphioxus embryos. We then address their function by transcription activator-like effector nucleases (TALEN)-based knockout and heat-shock promoter (HSP)-driven overexpression. Knockout of Cerberus leads to ectopic right-sided expression of Nodal , Lefty , and Pitx , whereas overexpression of Cerberus represses their left-sided expression. Overexpression of Nodal in turn represses Cerberus and activates Lefty and Pitx ectopically on the right side. We also show Lefty represses Nodal , whereas Pitx activates Nodal These data combine in a model in which Cerberus determines whether the left-sided gene expression cassette is activated or repressed. These regulatory steps are essential for normal left-right asymmetry to develop, as when they are disrupted embryos may instead form two phenotypic left sides or two phenotypic right sides. Our study shows the regulatory cassette controlling left-right asymmetry was in place in the ancestor of amphioxus and vertebrates. This includes the Nodal inhibitors Cerberus and Lefty, both of which operate in feedback loops with Nodal and combine to establish asymmetric Pitx expression. Cerberus and Lefty are missing from most invertebrate lineages, marking this mechanism as an innovation in the lineage leading to modern chordates.

  5. Turning breech babies after 34 weeks: the if, how, & when of turning breech babies.

    PubMed

    Cohain, Judy Slome

    2007-01-01

    Techniques for turning a term breech baby are 1). External cephalic version (ECV) using hands and ultrasound only; 2). Acupuncture point stimulation, by needle or moxibustion; 3). Chiropractic "Webster" technique; 4). Hypnotherapy; and 5). Special exercises. Fifty % of breech fetuses at 34 weeks will turn by themselves to head down by 38 weeks. Therefore, to be considered effective, a technique for turning breech must turn the baby and keep it turned more than 50% of the time. Only ECV with an experienced practitioner has been documented to have a greater than 50% success rate at 37 weeks; in 95% of cases the head stays down. Most women experience the fetus turning by hand as quick but very painful. "Unstable lie" is sometimes used as a baseless excuse for inducing labor after the baby turns from breech to head down. (judyslome@hotmail.com).

  6. The validation of a swimming turn wall-contact-time measurement system: a touchpad application reliability study.

    PubMed

    Brackley, Victoria; Ball, Kevin; Tor, Elaine

    2018-05-12

    The effectiveness of the swimming turn is highly influential to overall performance in competitive swimming. The push-off or wall contact, within the turn phase, is directly involved in determining the speed the swimmer leaves the wall. Therefore, it is paramount to develop reliable methods to measure the wall-contact-time during the turn phase for training and research purposes. The aim of this study was to determine the concurrent validity and reliability of the Pool Pad App to measure wall-contact-time during the freestyle and backstroke tumble turn. The wall-contact-times of nine elite and sub-elite participants were recorded during their regular training sessions. Concurrent validity statistics included the standardised typical error estimate, linear analysis and effect sizes while the intraclass correlating coefficient (ICC) was used for the reliability statistics. The standardised typical error estimate resulted in a moderate Cohen's d effect size with an R 2 value of 0.80 and the ICC between the Pool Pad and 2D video footage was 0.89. Despite these measurement differences, the results from this concurrent validity and reliability analyses demonstrated that the Pool Pad is suitable for measuring wall-contact-time during the freestyle and backstroke tumble turn within a training environment.

  7. Smart design of a long-period fiber grating refractive index sensor based on dual-peak resonance near the phase-matching turning point.

    PubMed

    Ling, Qiang; Gu, Zhengtian; Gao, Kan

    2018-04-01

    This paper presents a smart design way for the long-period fiber grating (LPFG) refractive index sensor, which is based on high sensitivity of LPFG near phase-matching turning point (PMTP) to the surrounding refractive index (SRI). On the basis of the coupled mode theory of LPFG, cladding etching and film coating have opposite effects on the shift of the dual peaks. Therefore, an LPFG can be controlled by the cladding etching and film coating successively, until it operates near PMTP. Experimentally, an LPFG operating near PMTP was fabricated, and the glycerol solution concentration monitoring test was performed. The results show that the sensitivity of this LPFG to the SRI is as high as 5602 nm/refractive index unit.

  8. Turn Basin Construction

    NASA Image and Video Library

    2017-06-14

    Modifications are underway at the Launch Complex 39 turn basin wharf at NASA's Kennedy Space Center in Florida to prepare for the arrival of the agency's massive Space Launch System (SLS) core stage aboard the barge Pegasus. Precast concrete poles are being driven to a depth of about 70 feet into the bedrock below the water around the turn basin. The upgrades are necessary to accommodate the increased weight of the core stage along with ground support and transportation equipment aboard the modified barge Pegasus. The Ground Systems Development and Operations Program is overseeing the upgrades to the turn basin wharf.

  9. Lower extremity control during turns initiated with and without hip external rotation.

    PubMed

    Zaferiou, Antonia M; Flashner, Henryk; Wilcox, Rand R; McNitt-Gray, Jill L

    2017-02-08

    The pirouette turn is often initiated in neutral and externally rotated hip positions by dancers. This provides an opportunity to investigate how dancers satisfy the same mechanical objectives at the whole-body level when using different leg kinematics. The purpose of this study was to compare lower extremity control strategies during the turn initiation phase of pirouettes performed with and without hip external rotation. Skilled dancers (n=5) performed pirouette turns with and without hip external rotation. Joint kinetics during turn initiation were determined for both legs using ground reaction forces (GRFs) and segment kinematics. Hip muscle activations were monitored using electromyography. Using probability-based statistical methods, variables were compared across turn conditions as a group and within-dancer. Despite differences in GRFs and impulse generation between turn conditions, at least 90% of each GRF was aligned with the respective leg plane. A majority of the net joint moments at the ankle, knee, and hip acted about an axis perpendicular to the leg plane. However, differences in shank alignment relative to the leg plane affected the distribution of the knee net joint moment when represented with respect to the shank versus the thigh. During the initiation of both turns, most participants used ankle plantar flexor moments, knee extensor moments, flexor and abductor moments at the push leg׳s hip, and extensor and abductor moments at the turn leg׳s hip. Representation of joint kinetics using multiple reference systems assisted in understanding control priorities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Effects of leg dominance on performance of ballet turns (pirouettes) by experienced and novice dancers.

    PubMed

    Lin, Chia-Wei; Su, Fong-Chin; Wu, Hong-Wen; Lin, Cheng-Feng

    2013-01-01

    Turns (pirouettes) are an important movement in ballet and may be affected by "lateral bias". This study investigated physiological differences exhibited by experienced and novice dancers, respectively, when performing pirouette with dominant and non-dominant leg supports, respectively. Thirteen novice and 13 experienced dancers performed turns on dominant or non-dominant legs. The maximum ankle plantarflexion, knee extension and hip extension were measured during the single-leg support phase. The inclination angle of rotation axis is the angle between instantaneous rotation axis and global vertical axis in the early single-leg support phase. Both groups exhibited a greater hip extension, knee extension, and ankle plantarflexion when performing a turn on the non-dominant leg. For experienced dancers, the inclination angle of rotation axis during the pre-swing phase was generally smaller for dominant leg support than non-dominant leg. However, no significant difference was found in inclination angle of rotation axis of novice dancers. For experienced dancers, an improved performance is obtained when using the dominant leg for support. By contrast, for novice dancers, the performance is independent of choice of support leg. The significant lateral bias in experienced dancers indicates the possible influence of training. That is, repetitive rehearsal on the preferred leg strengthens the impact of side dominance in experienced dancers.

  11. Comparison of left atrial size and function in hypertrophic cardiomyopathy and in Fabry disease with left ventricular hypertrophy.

    PubMed

    Saccheri, María Cristina; Cianciulli, Tomás Francisco; Challapa Licidio, Wilde; Lax, Jorge A; Beck, Martín A; Morita, Luis A; Gagliardi, Juan A

    2018-05-01

    Fabry disease (FD) and hypertrophic cardiomyopathy (HCM) are two diseases with a different pathophysiology, both cause left ventricular hypertrophy (LVH) and myocardial fibrosis. Although remodeling and systolic dysfunction of the left atrium (LA) are associated with atrial fibrillation and stroke in HCM, changes in the size and function of the LA have not been well studied in FD with LVH. The following groups were studied prospectively, and their respective findings compared: 19 patients with non-obstructive HCM (Group I), 20 patients with a diagnosis of Fabry cardiomyopathy (Group II), and 20 normal subjects matched for sex and age (Group III). Left ventricular mass index was measured using Devereux' formula, left atrial volume with Simpson's biplane method and left atrial mechanical function, including strain and strain rate, was measured using the speckle tracking technique. Strain and strain rate of the reservoir were measured during the three phases: reservoir (SR S), passive conduit (SR E) and atrial contraction (SR A). Patients with HCM had a larger left atrial volume than patients with FD (48.16 ± 14.3 mL/m 2 vs 38.9 ± 14.9 mL/m 2 respectively, P < .001), but in both disorders there was a severe decrease in left atrial function: reservoir strain in the apical four-chamber view: 17.47% in HCM vs 22.5% in FD, P = .24), strain rate in the apical chamber view: SR A: -0.80/seconds in HCM vs -1.04/seconds in FD (P = .88), SR S: 0.69/seconds in HCM vs 0.93 in FD (P = .12), SR E: -0.80 seconds in HCM vs -0.97/seconds in FD (P = .18). In this echocardiographic study we used speckle tracking to assess left atrial mechanical function and showed that FD is associated to an atrial cardiomyopathy, affecting the three phasic functions of the LA. Although in patients with HCM left atrial volume is larger than in patients with FD, both disorders exhibit severe decrease in left atrial function. These findings should be considered, given the potentially

  12. Determination of linear optics functions from turn-by-turn data

    NASA Astrophysics Data System (ADS)

    Alexahin, Y.; Gianfelice-Wendt, E.

    2011-10-01

    A method for evaluation of coupled optics functions, detection of strong perturbing elements, determination of BPM calibration errors and tilts using turn-by-turn (TBT) data is presented as well as the new version of the Hamiltonian perturbation theory of betatron oscillations the method is based upon. An example of application of the considered method to the Tevatron is given.

  13. Turn Basin Construction

    NASA Image and Video Library

    2017-06-14

    Modifications are underway at the Launch Complex 39 turn basin wharf at NASA's Kennedy Space Center in Florida to prepare for the arrival of the agency's massive Space Launch System (SLS) core stage aboard the barge Pegasus. A crane will be used to lift up precast concrete poles and position them to be driven to a depth of about 70 feet into the bedrock below the water around the turn basin. The upgrades are necessary to accommodate the 300,000-pound core booster aboard the modified Pegasus barge. The Ground Systems Development and Operations Program is overseeing the upgrades to the turn basin wharf.

  14. Measuring zebrafish turning rate.

    PubMed

    Mwaffo, Violet; Butail, Sachit; di Bernardo, Mario; Porfiri, Maurizio

    2015-06-01

    Zebrafish is becoming a popular animal model in preclinical research, and zebrafish turning rate has been proposed for the analysis of activity in several domains. The turning rate is often estimated from the trajectory of the fish centroid that is output by commercial or custom-made target tracking software run on overhead videos of fish swimming. However, the accuracy of such indirect methods with respect to the turning rate associated with changes in heading during zebrafish locomotion is largely untested. Here, we compare two indirect methods for the turning rate estimation using the centroid velocity or position data, with full shape tracking for three different video sampling rates. We use tracking data from the overhead video recorded at 60, 30, and 15 frames per second of zebrafish swimming in a shallow water tank. Statistical comparisons of absolute turning rate across methods and sampling rates indicate that, while indirect methods are indistinguishable from full shape tracking, the video sampling rate significantly influences the turning rate measurement. The results of this study can aid in the selection of the video capture frame rate, an experimental design parameter in zebrafish behavioral experiments where activity is an important measure.

  15. Assessment of Intrafraction Breathing Motion on Left Anterior Descending Artery Dose During Left-Sided Breast Radiation Therapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    El-Sherif, Omar, E-mail: Omar.ElSherif@lhsc.on.ca; Department of Physics, London Regional Cancer Program, London, Ontario; Yu, Edward

    Purpose: To use 4-dimensional computed tomography (4D-CT) imaging to predict the level of uncertainty in cardiac dose estimates of the left anterior descending artery that arises due to breathing motion during radiation therapy for left-sided breast cancer. Methods and Materials: The fast helical CT (FH-CT) and 4D-CT of 30 left-sided breast cancer patients were retrospectively analyzed. Treatment plans were created on the FH-CT. The original treatment plan was then superimposed onto all 10 phases of the 4D-CT to quantify the dosimetric impact of respiratory motion through 4D dose accumulation (4D-dose). Dose-volume histograms for the heart, left ventricle (LV), and left anteriormore » descending (LAD) artery obtained from the FH-CT were compared with those obtained from the 4D-dose. Results: The 95% confidence interval of 4D-dose and FH-CT differences in mean dose estimates for the heart, LV, and LAD were ±0.5 Gy, ±1.0 Gy, and ±8.7 Gy, respectively. Conclusion: Fast helical CT is a good approximation for doses to the heart and LV; however, dose estimates for the LAD are susceptible to uncertainties that arise due to intrafraction breathing motion that cannot be ascertained without the additional information obtained from 4D-CT and dose accumulation. For future clinical studies, we suggest the use of 4D-CT–derived dose-volume histograms for estimating the dose to the LAD.« less

  16. Turn Basin Construction

    NASA Image and Video Library

    2017-06-14

    Modifications are underway at the Launch Complex 39 turn basin wharf at NASA's Kennedy Space Center in Florida to prepare for the arrival of the agency's massive Space Launch System (SLS) core stage aboard the barge Pegasus. Equipment is staged and a crane will be used to lift up precast concrete poles and position them to be driven to a depth of about 70 feet into the bedrock below the water around the turn basin. The upgrades are necessary to accommodate the increased weight of the core stage along with ground support and transportation equipment aboard the modified barge Pegasus. The Ground Systems Development and Operations Program is overseeing the upgrades to the turn basin wharf.

  17. Turn Basin Construction

    NASA Image and Video Library

    2017-06-14

    Modifications are underway at the Launch Complex 39 turn basin wharf at NASA's Kennedy Space Center in Florida to prepare for the arrival of the agency's massive Space Launch System (SLS) core stage aboard the barge Pegasus. A crane will be used to lift up precast concrete poles and position them to be driven to a depth of about 70 feet into the bedrock below the water around the turn basin. The upgrades are necessary to accommodate the increased weight of the core stage along with ground support and transportation equipment aboard the modified barge Pegasus. The Ground Systems Development and Operations Program is overseeing the upgrades to the turn basin wharf.

  18. Peptide design using alpha,beta-dehydro amino acids: from beta-turns to helical hairpins.

    PubMed

    Mathur, Puniti; Ramakumar, S; Chauhan, V S

    2004-01-01

    Incorporation of alpha,beta-dehydrophenylalanine (DeltaPhe) residue in peptides induces folded conformations: beta-turns in short peptides and 3(10)-helices in larger ones. A few exceptions-namely, alpha-helix or flat beta-bend ribbon structures-have also been reported in a few cases. The most favorable conformation of DeltaPhe residues are (phi,psi) approximately (-60 degrees, -30 degrees ), (-60 degrees, 150 degrees ), (80 degrees, 0 degrees ) or their enantiomers. DeltaPhe is an achiral and planar residue. These features have been exploited in designing DeltaPhe zippers and helix-turn-helix motifs. DeltaPhe can be incorporated in both right and left-handed helices. In fact, consecutive occurrence of three or more DeltaPhe amino acids induce left-handed screw sense in peptides containing L-amino acids. Weak interactions involving the DeltaPhe residue play an important role in molecular association. The C--H.O==C hydrogen bond between the DeltaPhe side-chain and backbone carboxyl moiety, pi-pi stacking interactions between DeltaPhe side chains belonging to enantiomeric helices have shown to stabilize folding. The unusual capability of a DeltaPhe ring to form the hub of multicentered interactions namely, a donor in aromatic C--H.pi and C--H.O==C and an acceptor in a CH(3).pi interaction suggests its exploitation in introducing long-range interactions in the folding of supersecondary structures. Copyright 2004 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2004

  19. Assessment of left ventricular mechanical dyssynchrony by phase analysis of gated-SPECT myocardial perfusion imaging and tissue Doppler imaging: comparison between QGS and ECTb software packages.

    PubMed

    Rastgou, Fereydoon; Shojaeifard, Maryam; Amin, Ahmad; Ghaedian, Tahereh; Firoozabadi, Hasan; Malek, Hadi; Yaghoobi, Nahid; Bitarafan-Rajabi, Ahmad; Haghjoo, Majid; Amouzadeh, Hedieh; Barati, Hossein

    2014-12-01

    Recently, the phase analysis of gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has become feasible via several software packages for the evaluation of left ventricular mechanical dyssynchrony. We compared two quantitative software packages, quantitative gated SPECT (QGS) and Emory cardiac toolbox (ECTb), with tissue Doppler imaging (TDI) as the conventional method for the evaluation of left ventricular mechanical dyssynchrony. Thirty-one patients with severe heart failure (ejection fraction ≤35%) and regular heart rhythm, who referred for gated-SPECT MPI, were enrolled. TDI was performed within 3 days after MPI. Dyssynchrony parameters derived from gated-SPECT MPI were analyzed by QGS and ECTb and were compared with the Yu index and septal-lateral wall delay measured by TDI. QGS and ECTb showed a good correlation for assessment of phase histogram bandwidth (PHB) and phase standard deviation (PSD) (r = 0.664 and r = 0.731, P < .001, respectively). However, the mean value of PHB and PSD by ECTb was significantly higher than that of QGS. No significant correlation was found between ECTb and QGS and the Yu index. Nevertheless, PHB, PSD, and entropy derived from QGS revealed a significant (r = 0.424, r = 0.478, r = 0.543, respectively; P < .02) correlation with septal-lateral wall delay. Despite a good correlation between QGS and ECTb software packages, different normal cut-off values of PSD and PHB should be defined for each software package. There was only a modest correlation between phase analysis of gated-SPECT MPI and TDI data, especially in the population of heart failure patients with both narrow and wide QRS complex.

  20. Kinematic, kinetic and EMG analysis of four front crawl flip turn techniques.

    PubMed

    Pereira, Suzana Matheus; Ruschel, Caroline; Hubert, Marcel; Machado, Leandro; Roesler, Helio; Fernandes, Ricardo Jorge; Vilas-Boas, João Paulo

    2015-01-01

    This study aimed to analyse the kinematic, kinetic and electromyographic characteristics of four front crawl flip turn technique variants. The variants distinguished from each other by differences in body position (i.e., dorsal, lateral, ventral) during rolling, wall support, pushing and gliding phases. Seventeen highly trained swimmers (17.9 ± 3.2 years old) participated in interventional sessions and performed three trials of each variant, being monitored with a 3-D video system, a force platform and an electromyography (EMG) system. Studied variables: rolling time and distance, wall support time, push-off time, peak force and horizontal impulse at wall support and push-off, centre of mass horizontal velocity at the end of the push-off, gliding time, centre of mass depth, distance, average and final velocity during gliding, total turn time and electrical activity of Gastrocnemius Medialis, Tibialis Anterior, Biceps Femoris and Vastus Lateralis muscles. Depending on the variant, total turn time ranged from 2.37 ± 0.32 to 2.43 ± 0.33 s, push-off force from 1.86 ± 0.33 to 1.92 ± 0.26 BW and centre of mass velocity during gliding from 1.78 ± 0.21 to 1.94 ± 0.22 m · s(-1). The variants were not distinguishable in terms of kinematical, kinetic and EMG parameters during the rolling, wall support, pushing and gliding phases.

  1. Improved Leg Tracking Considering Gait Phase and Spline-Based Interpolation during Turning Motion in Walk Tests.

    PubMed

    Yorozu, Ayanori; Moriguchi, Toshiki; Takahashi, Masaki

    2015-09-04

    Falling is a common problem in the growing elderly population, and fall-risk assessment systems are needed for community-based fall prevention programs. In particular, the timed up and go test (TUG) is the clinical test most often used to evaluate elderly individual ambulatory ability in many clinical institutions or local communities. This study presents an improved leg tracking method using a laser range sensor (LRS) for a gait measurement system to evaluate the motor function in walk tests, such as the TUG. The system tracks both legs and measures the trajectory of both legs. However, both legs might be close to each other, and one leg might be hidden from the sensor. This is especially the case during the turning motion in the TUG, where the time that a leg is hidden from the LRS is longer than that during straight walking and the moving direction rapidly changes. These situations are likely to lead to false tracking and deteriorate the measurement accuracy of the leg positions. To solve these problems, a novel data association considering gait phase and a Catmull-Rom spline-based interpolation during the occlusion are proposed. From the experimental results with young people, we confirm   that the proposed methods can reduce the chances of false tracking. In addition, we verify the measurement accuracy of the leg trajectory compared to a three-dimensional motion analysis system (VICON).

  2. Diastolic blood pressure-estimated left ventricular dp/dt.

    PubMed

    Yilmaz, Hüseyin; Minareci, Kenan; Kabukçu, Mehmet; Sancaktar, Oktay

    2002-02-01

    Peak dp/dt is one of the best isovolumic phase indexes of the myocardial contractile state requiring invasive procedures or presence of mitral regurgitation severe enough to measure in clinical practice by Doppler echocardiography. In this study, we sought the correlation between two noninvasive methods of measurements for left ventricular dp/dt-diastolic blood pressure- (DBP) estimated and continuous-wave Doppler-derived dp/dt-min electrocardiographic/echocardiographic study to emphasize the clinical feasibility of the DBP-estimated method. Thirty-six randomized patients (27 male, 9 female; 58 +/- 8 years) with mild mitral regurgitation were enrolled in this study. DBP-estimated dp/dt was calculated from DBP minus the left ventricular end-diastolic pressure (LVEDP) over the isovolumetric contraction time (IVCT). LVEDP was assumed to be 10 mmHg for all patients. Doppler-determined left ventricular dp/dt was derived from the continuous-wave Doppler spectrum of mitral regurgitation jet by dividing the magnitude of the left ventricular atrial pressure gradient rise between 1 mm/sec-3 mm/sec of mitral regurgitant velocity signal by the time taken for this change. Left ventricular dp/dt by Doppler was 1122 +/- 303 mmHg/sec and blood pressure-estimated dp/dt was 1063 +/- 294 mmHg/sec. There was a high correlation (r = 0.97, P < 0.001) of dp/dt between the two techniques. DBP and IVCT can generate left ventricular dp/dt without invasive procedures, even in the absence of mitral regurgitation in clinical practice.

  3. Turn Basin Construction

    NASA Image and Video Library

    2017-06-14

    Modifications are underway at the Launch Complex 39 turn basin wharf at NASA's Kennedy Space Center in Florida to prepare for the arrival of the agency's massive Space Launch System (SLS) core stage aboard the barge Pegasus. In the foreground is Tammy Kelly, site manager, with Southeast Cherokee Construction Inc. A crane will be used to lift up precast concrete poles and position them to be driven to a depth of about 70 feet into the bedrock below the water around the turn basin. The upgrades are necessary to accommodate the increased weight of the core stage along with ground support and transportation equipment aboard the modified barge Pegasus. The Ground Systems Development and Operations Program is overseeing the upgrades to the turn basin wharf.

  4. Guidelines for exclusive.

    DOT National Transportation Integrated Search

    1985-01-01

    The objective of this research was to develop guidelines for the use of exclusive/permissive left-turn signal phasing. This was achieved by collecting data on traffic and roadway conditions for exclusive, exclusive/permissive, and permissive left-tur...

  5. How northward turnings of the IMF can lead to substorm expansion onsets

    NASA Astrophysics Data System (ADS)

    Russell, C. T.

    2000-10-01

    The frequent triggering of the expansion phase of substorms by northward turnings of the interplanetary magnetic field (IMF) can be understood in terms of the existence of two neutral points. The distant neutral point produces a plasma sheet on closed field lines that resupplies the magnetized plasma surrounding the near-Earth neutral point. As long as the near-Earth neutral point reconnects in moderately dense plasma, the reconnection rate is low. When the IMF turns northward, reconnection at the distant neutral point ceases but reconnection at the near-Earth neutral point continues and soon reaches open, low density magnetic field lines where the rate of reconnection is rapid, and a full expansion phase occurs. This model is consistent with the observations of substorms with two onsets: an initial one at low invariant latitudes when reconnection at the near Earth neutral point first begins and the second when reconnection reaches low density field lines at the edge of the plasma sheet and continues into the open flux of the tail lobes. It is also consistent with the occurrence of pseudo breakups in which reconnection at the near Earth neutral point begins but does not proceed to lobe field lines and a full expansion phase.

  6. Immediate Effects of Clock-Turn Strategy on the Pattern and Performance of Narrow Turning in Persons With Parkinson Disease.

    PubMed

    Yang, Wen-Chieh; Hsu, Wei-Li; Wu, Ruey-Meei; Lin, Kwan-Hwa

    2016-10-01

    Turning difficulty is common in people with Parkinson disease (PD). The clock-turn strategy is a cognitive movement strategy to improve turning performance in people with PD despite its effects are unverified. Therefore, this study aimed to investigate the effects of the clock-turn strategy on the pattern of turning steps, turning performance, and freezing of gait during a narrow turning, and how these effects were influenced by concurrent performance of a cognitive task (dual task). Twenty-five people with PD were randomly assigned to the clock-turn or usual-turn group. Participants performed the Timed Up and Go test with and without concurrent cognitive task during the medication OFF period. The clock-turn group performed the Timed Up and Go test using the clock-turn strategy, whereas participants in the usual-turn group performed in their usual manner. Measurements were taken during the 180° turn of the Timed Up and Go test. The pattern of turning steps was evaluated by step time variability and step time asymmetry. Turning performance was evaluated by turning time and number of turning steps. The number and duration of freezing of gait were calculated by video review. The clock-turn group had lower step time variability and step time asymmetry than the usual-turn group. Furthermore, the clock-turn group turned faster with fewer freezing of gait episodes than the usual-turn group. Dual task increased the step time variability and step time asymmetry in both groups but did not affect turning performance and freezing severity. The clock-turn strategy reduces turning time and freezing of gait during turning, probably by lowering step time variability and asymmetry. Dual task compromises the effects of the clock-turn strategy, suggesting a competition for attentional resources.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A141).

  7. Compound measure of hand-foot-eye preference masked opposite turning behavior in healthy right-handers and non-right-handers: technical comment on Mohr et al. (2003).

    PubMed

    Mohr, C; Bracha, H S

    2004-10-01

    A previous article reported opposite turning behavior in right-handers and non-right-handers (C. Mohr. T. Landis, H. S. Bracha, & P. Brugger, 2003). This observation appears contradictory to the 1st study on long-term spontaneous turning behavior in healthy participants (H. S. Bracha, D. J. Seitz, J. Otemaa, & S. D. Click, 1987). These latter authors found a complex interaction between hemispheric dominance, preferred turning side, and sex. C. Mohr et al. (2003) argued that the differentiation of the population in hemisphere-dominant groups by a compound measure of hand-foot-eye preference might have masked their recent finding. Thus, this commentary presents a reanalysis of the original data set (H. S. Bracha et al., 1987). Replicating recent observation, right-handers preferred left-sided turns; and non-righthanders, right-sided turns. This replication strengthens the proposition that handedness and turning behavior might depend on interhemispheric dopamine asymmetries. Copyright 2004 APA.

  8. Revealing turning points in ecosystem functioning over the Northern Eurasian agricultural frontier.

    PubMed

    Horion, Stéphanie; Prishchepov, Alexander V; Verbesselt, Jan; de Beurs, Kirsten; Tagesson, Torbern; Fensholt, Rasmus

    2016-08-01

    The collapse of the Soviet Union in 1991 has been a turning point in the World history that left a unique footprint on the Northern Eurasian ecosystems. Conducting large scale mapping of environmental change and separating between naturogenic and anthropogenic drivers is a difficult endeavor in such highly complex systems. In this research a piece-wise linear regression method was used for breakpoint detection in Rain-Use Efficiency (RUE) time series and a classification of ecosystem response types was produced. Supported by earth observation data, field data, and expert knowledge, this study provides empirical evidence regarding the occurrence of drastic changes in RUE (assessment of the timing, the direction and the significance of these changes) in Northern Eurasian ecosystems between 1982 and 2011. About 36% of the study area (3.4 million km(2) ) showed significant (P < 0.05) trends and/or turning points in RUE during the observation period. A large proportion of detected turning points in RUE occurred around the fall of the Soviet Union in 1991 and in the following years which were attributed to widespread agricultural land abandonment. Our study also showed that recurrent droughts deeply affected vegetation productivity throughout the observation period, with a general worsening of the drought conditions in recent years. Moreover, recent human-induced turning points in ecosystem functioning were detected and attributed to ongoing recultivation and change in irrigation practices in the Volgograd region, and to increased salinization and increased grazing intensity around Lake Balkhash. The ecosystem-state assessment method introduced here proved to be a valuable support that highlighted hotspots of potentially altered ecosystems and allowed for disentangling human from climatic disturbances. © 2016 John Wiley & Sons Ltd.

  9. Nanostructural Evolution of Hard Turning Layers in Carburized Steel

    NASA Astrophysics Data System (ADS)

    Bedekar, Vikram

    speed indicated thermal transformation. Nanoindentation tests showed that the substructures produced by plastic deformation follow the Hall-Petch relationship while the structures produced by thermal transformation did not. This indicated a change in the hardness driver from dislocation hardening to phase transformation, both of which have a significant impact on fatigue life. Using hardness based flow stress numerical model, these relationships between the processing conditions and structural parameters were further explored. Results indicated that the hard turning process design space can be partitioned into three regions based on thermal phase transformations, plastic grain refinement, and a third regime where both mechanisms are active. It was found that the Zener-Holloman parameter can not only be used to predict post-turning grain size but also to partition the process space into regions of dominant microstructural mechanisms.

  10. Hydrogen Bonded Squaramide-Based Foldable Module Induces Both β- and α-Turns in Hairpin Structures of α-Peptides in Water.

    PubMed

    Martínez, Luís; Martorell, Gabriel; Sampedro, Ángel; Ballester, Pablo; Costa, Antoni; Rotger, Carmen

    2015-06-19

    A novel tertiary squaramido-based reverse-turn module SQ is reported, and its conformational properties are evaluated. This module is easily incorporated into a α-peptide sequence by conventional solid-phase peptide synthesis. The structure characterization of the hybrid squaramido-peptide 4 is described, showing that the turn segment induces the formation of hairpin structures in water through the formation of both αSQ- and βSQ-turns.

  11. Turn Basin Construction

    NASA Image and Video Library

    2017-06-14

    Modifications are underway at the Launch Complex 39 turn basin wharf at NASA's Kennedy Space Center in Florida to prepare for the arrival of the agency's massive Space Launch System (SLS) core stage aboard the barge Pegasus. Tammy Kelly, in the center, site manager, with Southeast Cherokee Construction Inc. talks with construction workers. A crane will be used to lift up precast concrete poles and position them to be driven to a depth of about 70 feet into the bedrock below the water around the turn basin. The upgrades are necessary to accommodate the increased weight of the core stage along with ground support and transportation equipment aboard the modified barge Pegasus. The Ground Systems Development and Operations Program is overseeing the upgrades to the turn basin wharf.

  12. An Active Insect Kinin Analog with 4-Aminopyroglutamate, A Novel cis-Peptide Bond, Type VI beta-Turn Motif

    DTIC Science & Technology

    2004-01-01

    2004 Wiley Periodicals, Inc.* Biopolymers 75: 412–419, 2004 Keywords: 4-aminopyroglutamic acid ; cis-peptide bond; -turn mimetic; constrained insect...biological evaluation of an insect kinin analog containing a novel, (2S,4S)-4-aminopyroglutamic acid (APy) com- ponent (Figure 1) that theoretical and...cricket diuretic bioassay system. FIGURE 1 A comparison of the structures of the tetrazole ([CN4], left) and 4-aminopyroglu- tamic acid (APy; right

  13. Hummingbirds control turning velocity using body orientation and turning radius using asymmetrical wingbeat kinematics

    PubMed Central

    Read, Tyson J. G.; Segre, Paolo S.; Middleton, Kevin M.; Altshuler, Douglas L.

    2016-01-01

    Turning in flight requires reorientation of force, which birds, bats and insects accomplish either by shifting body position and total force in concert or by using left–right asymmetries in wingbeat kinematics. Although both mechanisms have been observed in multiple species, it is currently unknown how each is used to control changes in trajectory. We addressed this problem by measuring body and wingbeat kinematics as hummingbirds tracked a revolving feeder, and estimating aerodynamic forces using a quasi-steady model. During arcing turns, hummingbirds symmetrically banked the stroke plane of both wings, and the body, into turns, supporting a body-dependent mechanism. However, several wingbeat asymmetries were present during turning, including a higher and flatter outer wingtip path and a lower more deviated inner wingtip path. A quasi-steady analysis of arcing turns performed with different trajectories revealed that changes in radius were associated with asymmetrical kinematics and forces, and changes in velocity were associated with symmetrical kinematics and forces. Collectively, our results indicate that both body-dependent and -independent force orientation mechanisms are available to hummingbirds, and that these kinematic strategies are used to meet the separate aerodynamic challenges posed by changes in velocity and turning radius. PMID:27030042

  14. Expanded turn conformations: characterization and sequence-structure correspondence in alpha-turns with implications in helix folding.

    PubMed

    Dasgupta, Bhaskar; Pal, Lipika; Basu, Gautam; Chakrabarti, Pinak

    2004-05-01

    Like the beta-turns, which are characterized by a limiting distance between residues two positions apart (i, i+3), a distance criterion (involving residues at positions i and i+4) is used here to identify alpha-turns from a database of known protein structures. At least 15 classes of alpha-turns have been enumerated based on the location in the phi,psi space of the three central residues (i+1 to i+3)-one of the major being the class AAA, where the residues occupy the conventional helical backbone torsion angles. However, moving towards the C-terminal end of the turn, there is a shift in the phi,psi angles towards more negative phi, such that the electrostatic repulsion between two consecutive carbonyl oxygen atoms is reduced. Except for the last position (i+4), there is not much similarity in residue composition at different positions of hydrogen and non-hydrogen bonded AAA turns. The presence or absence of Pro at i+1 position of alpha- and beta-turns has a bearing on whether the turn is hydrogen-bonded or without a hydrogen bond. In the tertiary structure, alpha-turns are more likely to be found in beta-hairpin loops. The residue composition at the beginning of the hydrogen bonded AAA alpha-turn has similarity with type I beta-turn and N-terminal positions of helices, but the last position matches with the C-terminal capping position of helices, suggesting that the existence of a "helix cap signal" at i+4 position prevents alpha-turns from growing into helices. Our results also provide new insights into alpha-helix nucleation and folding. Copyright 2004 Wiley-Liss, Inc.

  15. Left endocarditis, changes in the new millennium.

    PubMed

    Noureddine-López, Mariam; de la Torre-Lima, Javier; Ruiz-Morales, Josefa; Gálvez-Acebal, Juan; Hidalgo-Tenorio, Carmen; de Alarcón González, César Arístides

    2018-05-25

    a description of infective left endocarditis at the turn of the millennium. A multicentre prospective study into the left endocarditis using data collected from the Andalusian cohort for the study of cardiovascular infections during 1984-2014. Of the 1,604 endocarditis cases collected, 382 belonged to G1 (group-1, period 1983-1999) and 1,222 to G2 (group-2, 2000-2014). Patients in the new millennium have a significantly higher mean age, have more comorbidity and concomitant diseases, and nosocomial and health-related endocarditis are more frequent, as well as complications. An increase in methicillin-resistant Staphylococcus aureus, Enterococcus sp., Gram-negative bacilli and Streptococcus bovis was noted. Regarding treatment, there is an increase in the use of cephalosporins and a decrease in penicillins; there is more surgery when admitted to hospital and less delay. Mortality stands at around 30% in both millennia. In the multivariate analysis, mortality was associated with: previous millennium (G1), age, Charlson index, renal failure and septic shock, and aetiologically with Staphylococcus aureus. Mortality remains stable, despite diagnostic and therapeutic improvements, because patients are older, have greater comorbidity, a closer relationship with the health care system (nosocomial) and microorganisms are more aggressive. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

  16. Children coordinate in a recurrent social dilemma by taking turns and along dominance asymmetries.

    PubMed

    Grueneisen, Sebastian; Tomasello, Michael

    2017-02-01

    Humans constantly have to coordinate their decisions with others even when their interests are conflicting (e.g., when 2 drivers have to decide who yields at an intersection). So far, however, little is known about the development of these abilities. Here, we present dyads of 5-year-olds (N = 40) with a repeated chicken game using a novel methodology: Two children each steered an automated toy train carrying a reward. The trains simultaneously moved toward each other so that in order to avoid a crash-which left both children empty-handed-1 train had to swerve. By swerving, however, the trains lost a portion of the rewards so that it was in each child's interest to go straight. Children coordinated their decisions successfully over multiple rounds, and they mostly did so by taking turns at swerving. In dyads in which turn-taking was rare, dominant children obtained significantly higher payoffs than their partners. Moreover, the coordination process was more efficient in turn-taking dyads as indicated by a significant reduction in conflicts and verbal protest. These findings indicate that already by the late preschool years children can independently coordinate decisions with peers in recurrent conflicts of interest. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  17. Relationship Between Head-Turn Gait Speed and Lateral Balance Function in Community-Dwelling Older Adults.

    PubMed

    Singh, Harshvardhan; Sanders, Ozell; McCombe Waller, Sandy; Bair, Woei-Nan; Beamer, Brock; Creath, Robert A; Rogers, Mark W

    2017-10-01

    To determine and compare gait speed during head-forward and side-to-side head-turn walking in individuals with lower versus greater lateral balance. Cross-sectional study. University research laboratory. Older adults (N=93; 42 men, 51 women; mean age ± SD, 73 ± 6.08y) who could walk independently. (1) Balance tolerance limit (BTL), defined as the lowest perturbation intensity where a multistep balance recovery pattern was first evoked in response to randomized lateral waist-pull perturbations of standing balance to the left and right sides, at 6 different intensities (range from level 2: 4.5-cm displacement at 180cm/s 2 acceleration, to level 7: 22.5-cm displacement at 900cm/s 2 acceleration); (2) gait speed, determined using an instrumented gait mat; (3) balance, evaluated with the Activities-specific Balance Confidence Scale; and (4) mobility, determined with the Timed Up and Go (TUG). Individuals with low versus high BTL had a slower self-selected head-forward gait speed and head-turn gait speed (P=.002 and P<.001, respectively); the magnitude of difference was greater in head-turn gait speed than head-forward gait speed (Cohen's d=1.0 vs 0.6). Head-turn gait speed best predicted BTL. BTL was moderately and positively related (P=.003) to the ABC Scale and negatively related (P=.017) to TUG. Head-turn gait speed is affected to a greater extent than head-forward gait speed in older individuals with poorer lateral balance and at greater risk of falls. Moreover, head-turn gait speed can be used to assess the interactions of limitations in lateral balance function and gait speed in relation to fall risk in older adults. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  18. Realistic page-turning of electronic books

    NASA Astrophysics Data System (ADS)

    Fan, Chaoran; Li, Haisheng; Bai, Yannan

    2014-01-01

    The booming electronic books (e-books), as an extension to the paper book, are popular with readers. Recently, many efforts are put into the realistic page-turning simulation o f e-book to improve its reading experience. This paper presents a new 3D page-turning simulation approach, which employs piecewise time-dependent cylindrical surfaces to describe the turning page and constructs smooth transition method between time-dependent cylinders. The page-turning animation is produced by sequentially mapping the turning page into the cylinders with different radii and positions. Compared to the previous approaches, our method is able to imitate various effects efficiently and obtains more natural animation of turning page.

  19. Response of the auroral electrojet indices to abrupt southward IMF turnings

    NASA Astrophysics Data System (ADS)

    Gjerloev, J. W.; Hoffman, R. A.; Ohtani, S.; Weygand, J.; Barnes, R.

    2010-05-01

    We present results from a study of the behavior of the auroral electrojet indices following abrupt southward turnings of the IMF Bz. The auroral electrojet indices are calculated from observations made by more than 100 ground based stations provided by the SuperMAG collaborators. Based on three simple criteria we selected 73 events. In each event the interval of analysis started at the time of the IMF Bz southward turning and ended 45 minutes later or at the onset of any abrupt energy unloading event in the magnetosphere, regardless of size. We refer to this period as the "pre-unloading phase". To isolate the dependence of the auroral electrojets on the solar induced ionospheric conductivity during this phase we separated the standard AU/AL indices into two new sets of indices defined by the upper and lower envelope of the north-south component for all sunlit stations (AUs/ALs) and for all stations in darkness (AUd/ALd). Based on events and statistical analyses we can conclude that following a southward turning of the IMF Bz the AUd/ALd indices show no measurable response while the AUs/ALs indices clearly intensify. The intensifications of AUs/ALs are dependent on the intensity of the solar wind driver (as measured by IMF Bz or the Akasofu ɛ parameter). The lack of AUd/ALd response does not depend on the intensity of any subsequent substorm. We find that during these isolated events the ionospheric current system is primarily confined to the sunlit ionosphere. This truncated version of the classical global DP-2 current system suggests that auroral electrojet continuity is not maintained across the terminator. Because of its conductivity dependence on the solar zenith angle, this truncated global current pattern is expected to be highly dependent on UT and season and thus can be asymmetric between hemispheres. Thus we argue that the global two-cell DP-2 current system is not a consequence only of a southward turning of the IMF but requires also the reduction of the

  20. Within compound, looking southeast Power Plant (Building 5761) to left, ...

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

    Within compound, looking southeast Power Plant (Building 5761) to left, Satellite Communications Terminal (Building 5771), center - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  1. Searching for Criteria in Evaluating the Monofin Swimming Turn from the Perspective of Coaching and Improving Technique

    PubMed Central

    Rejman, Marek; Borowska, Grażyna

    2008-01-01

    This study aims to analysise the selected kinematic parameters of the monofin swimming turn. The high complexity of performing turns is hindered by the large surface of the monofin, which disturbs control and sense of the body in water. A lack of objective data available on monofin swimming turns has resulted in field research connected with the specification of parameters needed for the evaluation of the technique. Therefore, turns observed in elite swimmers contain underlying conclusions for objective criteria, ensuring the highest level of coaching and the improving of turns in young swimmers. Six, high level, male swimmers participated in the study. The subject of the analysis was the fastest turn, from one out of three trial turns made after swimming a distance of 25 m. Images of the turns were collected from two cameras located under water in accordance with the procedures of the previous analyses of freestyle turns. The images were digitized and analysed by the SIMI®- Movement Analysis System. The interdependency of the total turn time and the remaining recorded parameters, constituted the basis for analysis of the kinematic parameters of five turn phases. The interdependency was measured using r- Pearson’s correlation coefficients. The novel character of the subject covered in this study, forced interpretation of the results on the basis of turn analyses in freestyle swimming. The results allow for the creation of a diagram outlinig area of search for an effective and efficient monofin swimming turn mechanism. The activities performed from the moment of wall contact until the commencement of stroking seem to be crucial for turn improvement. A strong belief has resulted that, the correct monofin swimming turn, is more than just a simple consequence of the fastest performance of all its components. The most important criteria in evaluating the quality of the monofin swimming turn are: striving for the optimal extension of wall contact time, push-off time

  2. Driving simulator study of J-Turn acceleration/deceleration lane and U-turn spacing.

    DOT National Transportation Integrated Search

    2016-11-01

    Carlos Sun : http://orcid.org/0000-0002-8857-9648 : The J-turn, also known as RCUT (Restricted Crossing U-Turn) and Superstreet, is an innovative geometric design that can improve intersection safety. Even though this design has been in use in severa...

  3. The differential effects of acute right- vs. left-sided vestibular failure on brain metabolism.

    PubMed

    Becker-Bense, Sandra; Dieterich, Marianne; Buchholz, Hans-Georg; Bartenstein, Peter; Schreckenberger, Mathias; Brandt, Thomas

    2014-07-01

    The human vestibular system is represented in the brain bilaterally, but it has functional asymmetries, i.e., a dominance of ipsilateral pathways and of the right hemisphere in right-handers. To determine if acute right- or left-sided unilateral vestibular neuritis (VN) is associated with differential patterns of brain metabolism in areas representing the vestibular network and the visual-vestibular interaction, patients with acute VN (right n = 9; left n = 13) underwent resting state (18)F-FDG PET once in the acute phase and once 3 months later after central vestibular compensation. The contrast acute vs. chronic phase showed signal differences in contralateral vestibular areas and the inverse contrast in visual cortex areas, both more pronounced in VN right. In VN left additional regions were found in the cerebellar hemispheres and vermis bilaterally, accentuated in severe cases. In general, signal changes appeared more pronounced in patients with more severe vestibular deficits. Acute phase PET data of patients compared to that of age-matched healthy controls disclosed similarities to these patterns, thus permitting the interpretation that the signal changes in vestibular temporo-parietal areas reflect signal increases, and in visual areas, signal decreases. These data imply that brain activity in the acute phase of right- and left-sided VN exhibits different compensatory patterns, i.e., the dominant ascending input is shifted from the ipsilateral to the contralateral pathways, presumably due to the missing ipsilateral vestibular input. The visual-vestibular interaction patterns were preserved, but were of different prominence in each hemisphere and more pronounced in patients with right-sided failure and more severe vestibular deficits.

  4. Free energy determinants of secondary structure formation: III. beta-turns and their role in protein folding.

    PubMed

    Yang, A S; Hitz, B; Honig, B

    1996-06-21

    The stability of beta-turns is calculated as a function of sequence and turn type with a Monte Carlo sampling technique. The conformational energy of four internal hydrogen-bonded turn types, I, I', II and II', is obtained by evaluating their gas phase energy with the CHARMM force field and accounting for solvation effects with the Finite Difference Poisson-Boltzmann (FDPB) method. All four turn types are found to be less stable than the coil state, independent of the sequence in the turn. The free-energy penalties associated with turn formation vary between 1.6 kcal/mol and 7.7 kcal/mol, depending on the sequence and turn type. Differences in turn stability arise mainly from intraresidue interactions within the two central residues of the turn. For each combination of the two central residues, except for -Gly-Gly-, the most stable beta-turn type is always found to occur most commonly in native proteins. The fact that a model based on local interactions accounts for the observed preference of specific sequences suggests that long-range tertiary interactions tend to play a secondary role in determining turn conformation. In contrast, for beta-hairpins, long-range interactions appear to dominate. Specifically, due to the right-handed twist of beta-strands, type I' turns for -Gly-Gly- are found to occur with high frequency, even when local energetics would dictate otherwise. The fact that any combination of two residues is found able to adopt a relatively low-energy turn structure explains why the amino acid sequence in turns is highly variable. The calculated free-energy cost of turn formation, when combined with related numbers obtained for alpha-helices and beta-sheets, suggests a model for the initiation of protein folding based on metastable fragments of secondary structure.

  5. Abdominal aortic aneurysm with aorta-left renal vein fistula with left varicocele.

    PubMed

    Meyerson, S L; Haider, S A; Gupta, N; O'Dorsio, J E; McKinsey, J F; Schwartz, L B

    2000-04-01

    Abdominal aortic aneurysm with spontaneous aorto-left renal vein fistula is a rare but well-described clinical entity usually with abdominal pain, hematuria, and a nonfunctioning left kidney. This report describes a 44-year-old man with left-sided groin pain and varicocele who was treated with conservative measures only. The diagnosis was eventually made when he returned with microscopic hematuria, elevated serum creatinine level, and nonfunction of the left kidney; computed tomography scan demonstrated a 6-cm abdominal aortic aneurysm, a retroaortic left renal vein, and an enlargement of the left kidney. This patient represents the youngest to be reported with aorto-left renal vein fistula and the second case with a left-sided varicocele.

  6. Turn Basin Construction

    NASA Image and Video Library

    2017-06-30

    At NASA's Kennedy Space Center in Florida, cement is poured as part of a construction project to upgrade the turn basin wharf. The work includes driving multiple precast concrete piles to a depth of about 70 feet to accommodate arrival of the core stage for the agency's Space Launch System (SLS) rocket. When the stage for NASA's SLS departs the Michoud Assembly Facility in New Orleans, it will be shipped by the agency's modified barge to the Launch Complex 39 turn basin.

  7. Abdicating power for control: a precision timing strategy to modulate function of flight power muscles.

    PubMed

    Sponberg, S; Daniel, T L

    2012-10-07

    Muscles driving rhythmic locomotion typically show strong dependence of power on the timing or phase of activation. This is particularly true in insects' main flight muscles, canonical examples of muscles thought to have a dedicated power function. However, in the moth (Manduca sexta), these muscles normally activate at a phase where the instantaneous slope of the power-phase curve is steep and well below maximum power. We provide four lines of evidence demonstrating that, contrary to the current paradigm, the moth's nervous system establishes significant control authority in these muscles through precise timing modulation: (i) left-right pairs of flight muscles normally fire precisely, within 0.5-0.6 ms of each other; (ii) during a yawing optomotor response, left-right muscle timing differences shift throughout a wider 8 ms timing window, enabling at least a 50 per cent left-right power differential; (iii) timing differences correlate with turning torque; and (iv) the downstroke power muscles alone causally account for 47 per cent of turning torque. To establish (iv), we altered muscle activation during intact behaviour by stimulating individual muscle potentials to impose left-right timing differences. Because many organisms also have muscles operating with high power-phase gains (Δ(power)/Δ(phase)), this motor control strategy may be ubiquitous in locomotor systems.

  8. Construction at Turn Basin

    NASA Image and Video Library

    2017-06-14

    Modifications are underway at the Launch Complex 39 turn basin wharf at NASA's Kennedy Space Center in Florida to prepare for the arrival of the agency's massive Space Launch System (SLS) core stage aboard the barge Pegasus. Precast concrete poles are being driven to a depth of about 70 feet into the bedrock below the water around the turn basin; later filled with concrete. The upgrades are necessary to accommodate the increased weight of the core stage along with ground support and transportation equipment aboard the modified barge Pegasus. The Ground Systems Development and Operations Program is overseeing the upgrades to the turn basin wharf.

  9. Does serotonin-modulating anticonsolidation protein (SMAP) influence the choice of turning direction in carps, Cyprinus carpio, in a T-maze?

    PubMed

    Garina, D V; Nepomnyashchikh, V A; Mekhtiev, A A

    2016-08-01

    Serotonin-modulating anticonsolidation protein (SMAP) can impair the formation of memory traces in mammals and fish. We have studied the influence of SMAP on behavioral lateralization of juvenile carps Cyprinus carpio in a T-maze without food reinforcement in three experimental groups (n = 8 each): (1) negative control (intact animals); (2) experimental group (fish injected ICV with SMAP; 2 μl, 1.2 mg ml(-1)) and (3) active control group (fish injected ICV with inactivated SMAP). The behavioral lateralization of carps was observed on the 1st, 2nd, 3rd and 6th days after the injections. In each observation session, a fish was placed five times in a start chamber of the T-maze. The direction of the turn upon leaving the start chamber, as well as the latency from the opening of start chamber flap to the fish's turn was registered. The number of right turns (of all five turns observed during the session) was a criterion of lateralization. It was found that carps have no inherent preference for turning left or right. The SMAP injection did not influence the choice of turning direction, but increases latency values insignificantly. The results are important for the correct interpretation and clarification of data reporting the role of SMAP in training and formation of spatial memory of fish in a maze.

  10. Transthoracic Ultrafast Doppler Imaging of Human Left Ventricular Hemodynamic Function

    PubMed Central

    Osmanski, Bruno-Félix; Maresca, David; Messas, Emmanuel; Tanter, Mickael; Pernot, Mathieu

    2016-01-01

    Heart diseases can affect intraventricular blood flow patterns. Real-time imaging of blood flow patterns is challenging because it requires both a high frame rate and a large field of view. To date, standard Doppler techniques can only perform blood flow estimation with high temporal resolution within small regions of interest. In this work, we used ultrafast imaging to map in 2D human left ventricular blood flow patterns during the whole cardiac cycle. Cylindrical waves were transmitted at 4800 Hz with a transthoracic phased array probe to achieve ultrafast Doppler imaging of the left ventricle. The high spatio-temporal sampling of ultrafast imaging permits to rely on a much more effective wall filtering and to increase sensitivity when mapping blood flow patterns during the pre-ejection, ejection, early diastole, diastasis and late diastole phases of the heart cycle. The superior sensitivity and temporal resolution of ultrafast Doppler imaging makes it a promising tool for the noninvasive study of intraventricular hemodynamic function. PMID:25073134

  11. 14 CFR 417.209 - Malfunction turn analysis.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... turn behavior for each cause of a malfunction turn. For each malfunction turn envelope, the analysis... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Malfunction turn analysis. 417.209 Section..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.209 Malfunction turn...

  12. 14 CFR 417.209 - Malfunction turn analysis.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... turn behavior for each cause of a malfunction turn. For each malfunction turn envelope, the analysis... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Malfunction turn analysis. 417.209 Section..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.209 Malfunction turn...

  13. 14 CFR 417.209 - Malfunction turn analysis.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... turn behavior for each cause of a malfunction turn. For each malfunction turn envelope, the analysis... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Malfunction turn analysis. 417.209 Section..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.209 Malfunction turn...

  14. Relationship between linear velocity and tangential push force while turning to change the direction of the manual wheelchair.

    PubMed

    Hwang, Seonhong; Lin, Yen-Sheng; Hogaboom, Nathan S; Wang, Lin-Hwa; Koontz, Alicia M

    2017-08-28

    Wheelchair propulsion is a major cause of upper limb pain and injuries for manual wheelchair users with spinal cord injuries (SCIs). Few studies have investigated wheelchair turning biomechanics on natural ground surfaces. The purpose of this study was to investigate the relationship between tangential push force and linear velocity of the wheelchair during the turning portions of propulsion. Using an instrumented handrim, velocity and push force data were recorded for 25 subjects while they propel their own wheelchairs on a concrete floor along a figure-eight-shaped course at a maximum velocity. The braking force (1.03 N) of the inside wheel while turning was the largest of all other push forces (p<0.05). Larger changes in squared velocity while turning were significantly correlated with higher propulsive and braking forces used at the pre-turning, turning, and post-turning phases (p<0.05). Subjects with less change of velocity while turning needed less braking force to maneuver themselves successfully and safely around the turns. Considering the magnitude and direction of tangential force applied to the wheel, it seems that there are higher risks of injury and instability for upper limb joints when braking the inside wheel to turn. The results provide insight into wheelchair setup and mobility skills training for wheelchair users.

  15. NetTurnP--neural network prediction of beta-turns by use of evolutionary information and predicted protein sequence features.

    PubMed

    Petersen, Bent; Lundegaard, Claus; Petersen, Thomas Nordahl

    2010-11-30

    β-turns are the most common type of non-repetitive structures, and constitute on average 25% of the amino acids in proteins. The formation of β-turns plays an important role in protein folding, protein stability and molecular recognition processes. In this work we present the neural network method NetTurnP, for prediction of two-class β-turns and prediction of the individual β-turn types, by use of evolutionary information and predicted protein sequence features. It has been evaluated against a commonly used dataset BT426, and achieves a Matthews correlation coefficient of 0.50, which is the highest reported performance on a two-class prediction of β-turn and not-β-turn. Furthermore NetTurnP shows improved performance on some of the specific β-turn types. In the present work, neural network methods have been trained to predict β-turn or not and individual β-turn types from the primary amino acid sequence. The individual β-turn types I, I', II, II', VIII, VIa1, VIa2, VIba and IV have been predicted based on classifications by PROMOTIF, and the two-class prediction of β-turn or not is a superset comprised of all β-turn types. The performance is evaluated using a golden set of non-homologous sequences known as BT426. Our two-class prediction method achieves a performance of: MCC=0.50, Qtotal=82.1%, sensitivity=75.6%, PPV=68.8% and AUC=0.864. We have compared our performance to eleven other prediction methods that obtain Matthews correlation coefficients in the range of 0.17-0.47. For the type specific β-turn predictions, only type I and II can be predicted with reasonable Matthews correlation coefficients, where we obtain performance values of 0.36 and 0.31, respectively. The NetTurnP method has been implemented as a webserver, which is freely available at http://www.cbs.dtu.dk/services/NetTurnP/. NetTurnP is the only available webserver that allows submission of multiple sequences.

  16. Stomach curvature is generated by left-right asymmetric gut morphogenesis

    PubMed Central

    Davis, Adam; Amin, Nirav M.; Johnson, Caroline; Bagley, Kristen; Ghashghaei, H. Troy

    2017-01-01

    Left-right (LR) asymmetry is a fundamental feature of internal anatomy, yet the emergence of morphological asymmetry remains one of the least understood phases of organogenesis. Asymmetric rotation of the intestine is directed by forces outside the gut, but the morphogenetic events that generate anatomical asymmetry in other regions of the digestive tract remain unknown. Here, we show in mouse and Xenopus that the mechanisms that drive the curvature of the stomach are intrinsic to the gut tube itself. The left wall of the primitive stomach expands more than the right wall, as the left epithelium becomes more polarized and undergoes radial rearrangement. These asymmetries exist across several species, and are dependent on LR patterning genes, including Foxj1, Nodal and Pitx2. Our findings have implications for how LR patterning manifests distinct types of morphological asymmetries in different contexts. PMID:28242610

  17. Intraoperative left subclavian artery occlusion with left hand ischaemia and steal syndrome in the left internal thoracic artery

    PubMed Central

    Jelenc, Matija; Kneževič, Ivan; Stankovič, Milenko; Geršak, Borut

    2012-01-01

    We present a case of a 62-year old man with a left main stenosis, left coronary artery dominance, normal ejection fraction and no valvular pathology, and status post right carotid artery stenting, who was scheduled for elective coronary revascularization. We performed off-pump coronary revascularization, anastomosing the left internal thoracic artery to the left anterior descending artery, and three separate saphenous vein grafts to the intermediate artery and the first and second obtuse marginals, respectively. Proximally, the right internal thoracic artery was used as the inflow for all three venous grafts due to a heavily calcified ascending aorta. During the construction of the distal anastomoses to the obtuse marginals, the arterial pressure in the left radial artery suddenly dropped. The left hand was found to be pale and pulseless. A femoral artery catheter was placed for pressure monitoring and the anastomoses were completed as planned. Intraoperative transit-time graft flow measurement showed a reversed flow in the left internal thoracic artery. Postoperatively, angiography was performed showing a subtotal stenosis of the proximal left subclavian artery. The artery was dilated and stented. The postoperative course was uneventful and the patient was discharged on the 12th postoperative day. PMID:22767542

  18. Looking northwest, Face B Array to left, Face C (rear) ...

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

    Looking northwest, Face B Array to left, Face C (rear) center, Power Plant (Building 5761), to right - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Techinical Equipment Building, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  19. Turn Basin Construction

    NASA Image and Video Library

    2017-06-30

    Across from the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, cement trucks stand by to support a construction project to upgrade the turn basin wharf. The work includes driving multiple precast concrete piles to a depth of about 70 feet to accommodate arrival of the core stage for the agency's Space Launch System (SLS) rocket. When the stage for NASA's SLS departs the Michoud Assembly Facility in New Orleans, it will be shipped by the agency's modified barge to the Launch Complex 39 turn basin.

  20. Turn Basin Construction

    NASA Image and Video Library

    2017-06-30

    Across from the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, cement is poured as part of a construction project to upgrade the turn basin wharf. The work includes driving multiple precast concrete piles to a depth of about 70 feet to accommodate arrival of the core stage for the agency's Space Launch System (SLS) rocket. When the stage for NASA's SLS departs the Michoud Assembly Facility in New Orleans, it will be shipped by the agency's modified barge to the Launch Complex 39 turn basin.

  1. Measurement and Comparison of Taekwondo and Yongmudo Turning Kick Impact Force for Two Target Heights

    PubMed Central

    O’Sullivan, David; Chung, Chulsoo; Lee, Kikwang; Kim, Euihwan; Kang, Sungchul; Kim, Taewhan; Shin, Insik

    2009-01-01

    The primary purpose of this research was to compare the impact characteristics of Taekwondo (TKD) and Yongmudo (YMD) player’s turning kick according to the target height. 5 highly skilled YMD and 5 TKD players participated in this study. To measure the impact force, two accelerometers were fixed to a PVC pipe in a sandbag. Each participant performed 10 turning kicks trunk and face height in random order. Only the trial with the most accurate (most central impact) measurement was used in the statistical analysis (p < 0.05).There was a significant difference for impact force according to the target height approximately 6400 ± 898 N, 6393 ± 1382 N for the mid section and 5419 ± 659 N, 5475 ± 1293 N for the high section of TKD and YMD groups, but not between groups. The swing phase for the TKD group was significantly shorter than the YMD group’s. The TKD groups’ recovery phase of the trunk height turning kick was significantly shorter. There was a difference in the players’ center of mass (COM) movement as the TKD players’ moved significantly more forward, suggesting that the TKD players tended to slide towards the target during the execution of the kick. In conclusion, as the turning kick was performed quicker by the TKD players with a similar impact force and more forward motion, it is evaluated to be a better technique of turning kicking. Key Points This impact force measuring device had a significantly smaller standard deviation then that of impact force measuring devices. There was a significant difference between the impact forces according to the height approximately 6400 ± 898N, 6393 ± 1382N for the mid section and 5419 ± 659N, 5475 ± 1293N for the high section of TKD and YMD groups. The turning kick was performed quicker by the TKD players with a similar impact force and more forward motion. PMID:24474880

  2. Installation Restoration Program. Phase 2. Confirmation/Quantification. Stage 1. Air Force Plant 38, Porter, New York, RCRA (Resource Conservation and Recovery Act) Sites

    DTIC Science & Technology

    1988-04-01

    sites throughout Alaska, Idaho , Oregon, and Washington, including work at 10 sites on the National Priorities List. Major geohydrologic investigations...Mary’s Hospital, 5300 Military Rd., Lewiston , 278-4000 Hospital Emergetcy Room Niagara Falls Memorial Medical Center, 621 10th N.F. 278-4000 Poison...Hospital ( Lewiston ): Exit AFP 38; head West on Balmer Road; Turn left and head south on State Highway 18; Turn left on State Highway 104 ( Lewiston Rd

  3. Interaction of the body, head, and eyes during walking and turning

    NASA Technical Reports Server (NTRS)

    Imai, T.; Moore, S. T.; Raphan, T.; Cohen, B.

    2001-01-01

    Body, head, and eye movements were measured in five subjects during straight walking and while turning corners. The purpose was to determine how well the head and eyes followed the linear trajectory of the body in space and whether head orientation followed changes in the gravito-inertial acceleration vector (GIA). Head and body movements were measured with a video-based motion analysis system and horizontal, vertical, and torsional eye movements with video-oculography. During straight walking, there was lateral body motion at the stride frequency, which was at half the frequency of stepping. The GIA oscillated about the direction of heading, according to the acceleration and deceleration associated with heel strike and toe flexion, and the body yawed in concert with stepping. Despite the linear and rotatory motions of the head and body, the head pointed along the forward motion of the body during straight walking. The head pitch/roll component appeared to compensate for vertical and horizontal acceleration of the head rather than orienting to the tilt of the GIA or anticipating it. When turning corners, subjects walked on a 50-cm radius over two steps or on a 200-cm radius in five to seven steps. Maximum centripetal accelerations in sharp turns were ca.0.4 g, which tilted the GIA ca.21 degrees with regard to the heading. This was anticipated by a roll tilt of the head of up to 8 degrees. The eyes rolled 1-1.5 degrees and moved down into the direction of linear acceleration during the tilts of the GIA. Yaw head deviations moved smoothly through the turn, anticipating the shift in lateral body trajectory by as much as 25 degrees. The trunk did not anticipate the change in trajectory. Thus, in contrast to straight walking, the tilt axes of the head and the GIA tended to align during turns. Gaze was stable in space during the slow phases and jumped forward in saccades along the trajectory, leading it by larger angles when the angular velocity of turning was greater

  4. Beta-and gamma-turns in proteins revisited: a new set of amino acid turn-type dependent positional preferences and potentials.

    PubMed

    Guruprasad, K; Rajkumar, S

    2000-06-01

    The number of beta-turns in a representative set of 426 protein three-dimensional crystal structures selected from the recent Protein Data Bank has nearly doubled and the number of gamma-turns in a representative set of 320 proteins has increased over seven times since the previous analysis. Beta-turns (7153) and gamma-turns (911) extracted from these proteins were used to derive a revised set of type-dependent amino acid positional preferences and potentials. Compared with previous results, the preference for proline, methionine and tryptophan has increased and the preference for glutamine, valine, glutamic acid and alanine has decreased for beta-turns. Certain new amino acid preferences were observed for both turn types and individual amino acids showed turn-type dependent positional preferences. The rationale for new amino acid preferences are discussed in the light of hydrogen bonds and other interactions involving the turns. Where main-chain hydrogen bonds of the type NH(i + 3) --> CO(i) were not observed for some beta-turns, other main-chain hydrogen bonds or solvent interactions were observed that possibly stabilize such beta-turns. A number of unexpected isolated beta-turns with proline at i + 2 position were also observed. The NH(i + 2) --> CO(i) hydrogen bond was observed for almost all gamma-turns. Nearly 20% classic gamma-turns and 43% inverse gamma-turns are isolated turns.

  5. Animal left-right asymmetry.

    PubMed

    Blum, Martin; Ott, Tim

    2018-04-02

    Symmetry is appealing, be it in architecture, art or facial expression, where symmetry is a key feature to finding someone attractive or not. Yet, asymmetries are widespread in nature, not as an erroneous deviation from the norm but as a way to adapt to the prevailing environmental conditions at a time. Asymmetries in many cases are actively selected for: they might well have increased the evolutionary fitness of a species. Even many single-celled organisms are built asymmetrically, such as the pear-shaped ciliate Paramecium, which may depend on its asymmetry to navigate towards the oxygen-richer surface of turbid waters, at least based on modeling. Everybody knows the lobster with its asymmetric pair of claws, the large crusher usually on the left and the smaller cutter on the right. Snail shells coil asymmetrically, as do the organs they house. Organ asymmetries are found throughout the animal kingdom, referring to asymmetric positioning, asymmetric morphology or both, with the vertebrate heart being an example for the latter. Functional asymmetries, such as that of the human brain with its localization of the language center in one hemisphere, add to the complexity of organ asymmetries and presumably played a decisive role for sociocultural evolution. The evolutionary origin of organ asymmetries may have been a longer than body length gut, which allows efficient retrieval of nutrients, and the need to stow a long gut in the body cavity in an orderly manner that ensures optimal functioning. Vertebrate organ asymmetries (situs solitus) are quite sophisticated: in humans, the apex of the asymmetrically built heart points to the left; the lung in turn, due to space restrictions, has fewer lobes on the left than on the right side (two versus three in humans), stomach and spleen are found on the left, the liver on the right, and small and large intestine coil in a chiral manner (Figure 1A). In very rare cases (1:10,000), the organ situs is inverted (situs inversus

  6. KENNEDY SPACE CENTER, FLA. - In a brief ceremony in the Space Station Processing Facility, Chuck Hardison (left), Boeing senior truss manager, turns over the “key” for the starboard truss segment S3/S4 to Scott Gahring, ISS Vehicle Office manager (acting), Johnson Space Center. The trusses are scheduled to be delivered to the International Space Station on mission STS-117.

    NASA Image and Video Library

    2004-02-12

    KENNEDY SPACE CENTER, FLA. - In a brief ceremony in the Space Station Processing Facility, Chuck Hardison (left), Boeing senior truss manager, turns over the “key” for the starboard truss segment S3/S4 to Scott Gahring, ISS Vehicle Office manager (acting), Johnson Space Center. The trusses are scheduled to be delivered to the International Space Station on mission STS-117.

  7. Contrast Media Delivery in the Assessment of Anomalous Left Coronary Artery From the Pulmonary Artery.

    PubMed

    Saade, Charbel; Al-Hamra, Salam; Al-Mohiy, Hussain; El-Merhi, Fadi

    2016-05-01

    A patient with a history of mitral valve prolapse and regurgitation that was corrected with a mitral ring repair 15 years earlier received a diagnosis of anomalous left coronary artery arising from the pulmonary artery and underwent repair. Coronary computed tomography angiography (CTA) was employed to image the patient before surgical intervention. Synchronizing contrast media administration to opacify the right coronary artery in the arterial phase and the left coronary artery in the venous phase required a test-bolus approach. Matching compromised cardiovascular dynamics with patient-specific contrast media administration protocols was improved considerably with the use of a test-bolus technique during electrocardiography-gated coronary CTA.

  8. Stomach curvature is generated by left-right asymmetric gut morphogenesis.

    PubMed

    Davis, Adam; Amin, Nirav M; Johnson, Caroline; Bagley, Kristen; Ghashghaei, H Troy; Nascone-Yoder, Nanette

    2017-04-15

    Left-right (LR) asymmetry is a fundamental feature of internal anatomy, yet the emergence of morphological asymmetry remains one of the least understood phases of organogenesis. Asymmetric rotation of the intestine is directed by forces outside the gut, but the morphogenetic events that generate anatomical asymmetry in other regions of the digestive tract remain unknown. Here, we show in mouse and Xenopus that the mechanisms that drive the curvature of the stomach are intrinsic to the gut tube itself. The left wall of the primitive stomach expands more than the right wall, as the left epithelium becomes more polarized and undergoes radial rearrangement. These asymmetries exist across several species, and are dependent on LR patterning genes, including Foxj1 , Nodal and Pitx2 Our findings have implications for how LR patterning manifests distinct types of morphological asymmetries in different contexts. © 2017. Published by The Company of Biologists Ltd.

  9. What Bed Size Does a Patient Need? The Relationship Between Body Mass Index and Space Required to Turn in Bed.

    PubMed

    Wiggermann, Neal; Smith, Kathryn; Kumpar, Dee

    A bed that is too small to allow patients to turn from supine to side lying increases the difficulty of mobilizing patients, which can increase risk of musculoskeletal injury to caregivers, increase risk of pressure injuries to patients, and reduce patient comfort. Currently, no guidance is available for what patient sizes are accommodated by the standard 91cm (36 in.)-wide hospital bed, and no studies have evaluated the relationship between anthropometric attributes and space required to turn in bed. The purpose of this research was to determine how much space individuals occupy when turning from supine to side lying as predicted by their anthropometry (i.e., body dimensions) to establish guidance on selecting the appropriate bed size. Forty-seven adult participants (24 female) with body mass index (BMI) from 20 to 76 kg/m participated in a laboratory study. Body dimensions were measured, and the envelope of space required to turn was determined using motion capture. Linear regressions estimated the relationship between anthropometric attributes and space occupied when turning. BMI was strongly correlated (R = .88) with the space required to turn. Based on the linear regressions, individuals with BMI up to 35 kg/m could turn left and right within 91 cm and individuals with BMI up to 45 kg/m could turn one direction within 91 cm. BMI is a good predictor of the space required to turn from supine to lateral. Nurses should consider placing patients that are unable to laterally reposition themselves on a wider bed when BMI is greater than 35 kg/m and should consider placing all patients greater than 45 kg/m on a wider bed regardless of mobility. Hospital administrators can use historical demographic information about the BMI of their patient populations to plan facility-level equipment procurement for equipment that accommodates their patients.

  10. Cathodal Transcranial Direct Current Stimulation Over Left Dorsolateral Prefrontal Cortex Area Promotes Implicit Motor Learning in a Golf Putting Task.

    PubMed

    Zhu, Frank F; Yeung, Andrew Y; Poolton, Jamie M; Lee, Tatia M C; Leung, Gilberto K K; Masters, Rich S W

    2015-01-01

    Implicit motor learning is characterized by low dependence on working memory and stable performance despite stress, fatigue, or multi-tasking. However, current paradigms for implicit motor learning are based on behavioral interventions that are often task-specific and limited when applied in practice. To investigate whether cathodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) area during motor learning suppressed working memory activity and reduced explicit verbal-analytical involvement in movement control, thereby promoting implicit motor learning. Twenty-seven healthy individuals practiced a golf putting task during a Training Phase while receiving either real cathodal tDCS stimulation over the left DLPFC area or sham stimulation. Their performance was assessed during a Test phase on another day. Verbal working memory capacity was assessed before and after the Training Phase, and before the Test Phase. Compared to sham stimulation, real stimulation suppressed verbal working memory activity after the Training Phase, but enhanced golf putting performance during the Training Phase and the Test Phase, especially when participants were required to multi-task. Cathodal tDCS over the left DLPFC may foster implicit motor learning and performance in complex real-life motor tasks that occur during sports, surgery or motor rehabilitation. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. STS-92 Mission Specialist McArthur is ready to take his turn driving the M-113

    NASA Technical Reports Server (NTRS)

    2000-01-01

    STS-92 Mission Specialist Bill McArthur gets ready to take his turn at driving the M-113, part of emergency egress training during Terminal Countdown Demonstration Test (TCDT) activities. Behind him (left) is Mission Specialist Jeff Wisoff, waiting his turn to drive along with other unidentified crew members. The tracked vehicle could be used by the crew in the event of an emergency at the pad during which the crew must make a quick exit from the area. The TCDT also provides simulated countdown exercises and opportunities to inspect the mission payloads in the orbiter's payload bay. STS-92 is scheduled to launch Oct. 5 at 9:30 p.m. EDT on the fifth flight to the International Space Station. It will carry two elements of the Space Station, the Integrated Truss Structure Z1 and the third Pressurized Mating Adapter. The mission is also the 100th flight in the Shuttle program.

  12. Why PeV scale left-right symmetry is a good thing

    NASA Astrophysics Data System (ADS)

    Yajnik, Urjit A.

    2017-10-01

    Left-right symmetric gauge theory presents a minimal paradigm to accommodate massive neutrinos with all the known conserved symmetries duly gauged. The work presented here is based on the argument that the see-saw mechanism does not force the new right-handed symmetry scale to be very high, and as such some of the species from the spectrum of the new gauge and Higgs bosons can have masses within a few orders of magnitude of the TeV scale. The scale of the left-right parity breaking in turn can be sequestered from the Planck scale by supersymmetry. We have studied several formulations of such just beyond Standard Model (JBSM) theories for their consistency with cosmology. Specifically, the need to eliminate phenomenologically undesirable domain walls gives many useful clues. The possibility that the exact left-right symmetry breaks in conjunction with supersymmetry has been explored in the context of gauge mediation, placing restrictions on the available parameter space. Finally, we have also studied a left-right symmetric model in the context of metastable supersymmetric vacua and obtained constraints on the mass scale of right-handed symmetry. In all the cases studied, the mass scale of the right-handed neutrino M_R remains bounded from above, and in some of the cases the scale 10^9 GeV favourable for supersymmetric thermal leptogenesis is disallowed. On the other hand, PeV scale remains a viable option, and the results warrant a more detailed study of such models for their observability in collider and astroparticle experiments.

  13. Aptamer-mediated 'turn-off/turn-on' nanozyme activity of gold nanoparticles for kanamycin detection.

    PubMed

    Sharma, Tarun Kumar; Ramanathan, Rajesh; Weerathunge, Pabudi; Mohammadtaheri, Mahsa; Daima, Hemant Kumar; Shukla, Ravi; Bansal, Vipul

    2014-12-28

    A new ultrafast and highly sensitive 'turn-off/turn-on' biosensing approach that combines the intrinsic peroxidase-like activity of gold nanoparticles (GNPs) with the high affinity and specificity of a ssDNA aptamer is presented for the efficient detection of a model small molecule kanamycin.

  14. Validation of geometric measurements of the left atrium and pulmonary veins for analysis of reverse structural remodeling following ablation therapy

    NASA Astrophysics Data System (ADS)

    Rettmann, M. E.; Holmes, D. R., III; Gunawan, M. S.; Ge, X.; Karwoski, R. A.; Breen, J. F.; Packer, D. L.; Robb, R. A.

    2012-03-01

    Geometric analysis of the left atrium and pulmonary veins is important for studying reverse structural remodeling following cardiac ablation therapy. It has been shown that the left atrium decreases in volume and the pulmonary vein ostia decrease in diameter following ablation therapy. Most analysis techniques, however, require laborious manual tracing of image cross-sections. Pulmonary vein diameters are typically measured at the junction between the left atrium and pulmonary veins, called the pulmonary vein ostia, with manually drawn lines on volume renderings or on image cross-sections. In this work, we describe a technique for making semi-automatic measurements of the left atrium and pulmonary vein ostial diameters from high resolution CT scans and multi-phase datasets. The left atrium and pulmonary veins are segmented from a CT volume using a 3D volume approach and cut planes are interactively positioned to separate the pulmonary veins from the body of the left atrium. The cut plane is also used to compute the pulmonary vein ostial diameter. Validation experiments are presented which demonstrate the ability to repeatedly measure left atrial volume and pulmonary vein diameters from high resolution CT scans, as well as the feasibility of this approach for analyzing dynamic, multi-phase datasets. In the high resolution CT scans the left atrial volume measurements show high repeatability with approximately 4% intra-rater repeatability and 8% inter-rater repeatability. Intra- and inter-rater repeatability for pulmonary vein diameter measurements range from approximately 2 to 4 mm. For the multi-phase CT datasets, differences in left atrial volumes between a standard slice-by-slice approach and the proposed 3D volume approach are small, with percent differences on the order of 3% to 6%.

  15. Dynamical relations for left ventricular ejection - Flow rate, momentum, force and impulse

    NASA Technical Reports Server (NTRS)

    Back, L. H.; Selzer, R. H.; Gordon, D. G.; Ledbetter, D. C.; Crawford, D. W.

    1984-01-01

    An investigation was carried out to quantitatively evaluate left ventricular volume flow rate, momentum, force and impulse derived from application of conservation principles for mass and momentum of blood within the ventricle during the ejection phase. An automated digital image processing system was developed and applied to left ventricular angiograms which are computer processed and analyzed frame by frame to determine the dynamical relations by numerical methods. The initial experience with force and impulse has indicated that neither quantity seemed to be a sensitive indicator of coronary artery disease as evaluated by qualitative angiography for the particular patient group studied. Utilization of the dynamical relations in evaluating human left ventricular performance requires improved means of measurement and interpretation of clinical studies.

  16. Temporal Fourier analysis applied to equilibrium radionuclide cineangiography. Importance in the study of global and regional left ventricular wall motion.

    PubMed

    Cardot, J C; Berthout, P; Verdenet, J; Bidet, A; Faivre, R; Bassand, J P; Bidet, R; Maurat, J P

    1982-01-01

    Regional and global left ventricular wall motion was assessed in 120 patients using radionuclide cineangiography (RCA) and contrast angiography. Functional imaging procedures based on a temporal Fourier analysis of dynamic image sequences were applied to the study of cardiac contractility. Two images were constructed by taking the phase and amplitude values of the first harmonic in the Fourier transform for each pixel. These two images aided in determining the perimeter of the left ventricle to calculate the global ejection fraction. Regional left ventricular wall motion was studied by analyzing the phase value and by examining the distribution histogram of these values. The accuracy of global ejection fraction calculation was improved by the Fourier technique. This technique increased the sensitivity of RCA for determining segmental abnormalities especially in the left anterior oblique view (LAO).

  17. Conformational interconversions in peptide beta-turns: analysis of turns in proteins and computational estimates of barriers.

    PubMed

    Gunasekaran, K; Gomathi, L; Ramakrishnan, C; Chandrasekhar, J; Balaram, P

    1998-12-18

    The two most important beta-turn features in peptides and proteins are the type I and type II turns, which differ mainly in the orientation of the central peptide unit. Facile conformational interconversion is possible, in principle, by a flip of the central peptide unit. Homologous crystal structures afford an opportunity to structurally characterize both possible conformational states, thus allowing identification of sites that are potentially stereochemically mobile. A representative data set of 250 high-resolution (turns that are assigned different conformational types (type I/type II) in related structures. A total of 55 examples of beta-turns were identified as possible candidates for a stereochemically mobile site. Of the 55 examples, 45 could be classified as a potential site for interconversion between type I and type II beta-turns, while ten correspond to flips from type I' to type II' structures. As a further check, the temperature factors of the central peptide unit carbonyl oxygen atom of the 55 examples were examined. The analysis reveals that the turn assignments are indeed reliable. Examination of the secondary structures at the flanking positions of the flippable beta-turns reveals that seven examples occur in the loop region of beta-hairpins, indicating that the formation of ordered secondary structures on either side of the beta-turn does not preclude local conformational variations. In these beta-turns, Pro (11 examples), Lys (nine examples) and Ser (seven examples) were most often found at the i+1 position. Glycine was found to occur overwhelmingly at position i+2 (28 examples), while Ser (seven examples) and Asn (six examples) were amongst the most frequent residues. Activation energy barriers for the interconversion between type I and type II beta-turns were computed

  18. Mars Polar Cap During Transition Phase Instrument Checkout

    NASA Technical Reports Server (NTRS)

    2006-01-01

    During the last week of September and the first week or so of October 2006, scientific instruments on NASA's Mars Reconnaissance Orbiter were turned on to acquire test information during the transition phase leading up to full science operations. The mission's primary science phase will begin the first week of November 2006, following superior conjunction. (Superior conjunction is where a planet goes behind the sun as viewed from Earth.) Since it is very difficult to communicate with a spacecraft when it is close to the sun as seen from Earth, this checkout of the instruments was crucial to being ready for the primary science phase of the mission.

    Throughout the transition-phase testing, the Mars Color Imager (MARCI) acquired terminator (transition between nighttime and daytime) to terminator swaths of color images on every dayside orbit, as the spacecraft moved northward in its orbit. The south polar region was deep in winter shadow, but the north polar region was illuminated the entire Martian day. During the primary mission, such swaths will be assembled into global maps that portray the state of the Martian atmosphere -- its weather -- as seen every day and at every place at about 3 p.m. local solar time. After the transition phase completed, most of the instruments were turned off, but the Mars Climate Sounder and MARCI have been left on. Their data will be recorded and played back to Earth following the communications blackout associated with conjunction.

    Combined with wide-angle image mosaics taken by the Mars Orbiter Camera on NASA's Mars Global Surveyor at 2 p.m. local solar time, the MARCI maps will be used to track motions of clouds.

    This image is a composite mosaic of four polar views of Mars, taken at midnight, 6 a.m., noon, and 6 p.m. local Martian time. This is possible because during summer the sun is always shining in the polar region. It shows the mostly water-ice perennial cap (white area), sitting atop the north polar layered

  19. 32 CFR 636.23 - Turning movements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Turning movements. 636.23 Section 636.23 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL... movements. (a) U-turns are prohibited on all streets in the cantonment area. (b) Right-turns will be made...

  20. Turn stability in beta-hairpin peptides: Investigation of peptides containing 3:5 type I G1 bulge turns.

    PubMed

    Blandl, Tamas; Cochran, Andrea G; Skelton, Nicholas J

    2003-02-01

    The turn-forming ability of a series of three-residue sequences was investigated by substituting them into a well-characterized beta-hairpin peptide. The starting scaffold, bhpW, is a disulfide-cyclized 10-residue peptide that folds into a stable beta-hairpin with two antiparallel strands connected by a two-residue reverse turn. Substitution of the central two residues with the three-residue test sequences leads to less stable hairpins, as judged by thiol-disulfide equilibrium measurements. However, analysis of NMR parameters indicated that each molecule retains a significant folded population, and that the type of turn adopted by the three-residue sequence is the same in all cases. The solution structure of a selected peptide with a PDG turn contained an antiparallel beta-hairpin with a 3:5 type I + G1 bulge turn. Analysis of the energetic contributions of individual turn residues in the series of peptides indicates that substitution effects have significant context dependence, limiting the predictive power of individual amino acid propensities for turn formation. The most stable and least stable sequences were also substituted into a more stable disulfide-cyclized scaffold and a linear beta-hairpin scaffold. The relative stabilities remained the same, suggesting that experimental measurements in the bhpW context are a useful way to evaluate turn stability for use in protein design projects. Moreover, these scaffolds are capable of displaying a diverse set of turns, which can be exploited for the mimicry of protein loops or for generating libraries of reverse turns.

  1. Turning collectors for solar radiation

    DOEpatents

    Barak, Amitzur Z.

    1976-01-01

    A device is provided for turning a solar collector about the polar axis so that the collector is directed toward the sun as the sun tracks the sky each day. It includes two heat-expansive elements and a shadow plate. In the morning a first expansive element is heated, expands to turn the collector to face the sun, while the second expansive element is shaded by the plate. In the afternoon the second element is heated, expands to turn the collector to face the sun, while the first is shaded by the plate.

  2. Super Gate Turn-Off Thyristor

    DTIC Science & Technology

    2006-08-01

    semiconductor (nMOS) and turned it off through a positive metal oxide semiconductor (pMOS). For turn-on, although 1 V worked, a HP6227B power supply at 2...E3614A power supply at –8 V provided IG during the rise time, and thus need enough capacitance working to a frequency around 3/trise time...load’s screw terminal posts would have reduced the ESL and ESR. The SGTO turned off 5.8 A from the power supply at 20 V and was usually fan cooled

  3. When Is It My Turn To Speak?

    ERIC Educational Resources Information Center

    Orestrom, Bengt

    A study analyzed four dyadic conversations for evidence of the signals operating in the turn-taking process and facilitating the smooth exchange of turns. It found over 20 syntactic, prosodic, and semantic features occurring frequently with turn-taking. The five most significant factors correlating with turn-taking were a prosodically completed…

  4. Leg coordination during turning on an extremely narrow substrate in a bug, Mesocerus marginatus (Heteroptera, Coreidae).

    PubMed

    Frantsevich, Leonid I; Cruse, Holk

    2005-10-01

    The turning movement of a bug, Mesocerus marginatus, is observed when it walks upside-down below a horizontal beam and, at the end of the beam, performs a sharp turn by 180 degrees . The turn at the end of the beam is accomplished in three to five steps, without strong temporal coordination among legs. During the stance, leg endpoints (tarsi) run through rounded trajectories, rotating to the same side in all legs. During certain phases of the turn, a leg is strongly depressed and the tarsus crosses the midline. Swing movements rotate to the same side as do leg endpoints in stance, in strong contrast to the typical swing movements found in turns or straight walk on a flat surface. Terminal location is found after the search through a trajectory that first moves away from the body and then loops back to find substrate. When a leg during stance has crossed the midline, in the following swing movement the leg may move even stronger on the contralateral side, i.e. is stronger depressed, in contrast to swing movements in normal walking, where the leg is elevated. These results suggest that the animals apply a different control strategy compared to walking and turning on a flat surface.

  5. NetTurnP – Neural Network Prediction of Beta-turns by Use of Evolutionary Information and Predicted Protein Sequence Features

    PubMed Central

    Petersen, Bent; Lundegaard, Claus; Petersen, Thomas Nordahl

    2010-01-01

    β-turns are the most common type of non-repetitive structures, and constitute on average 25% of the amino acids in proteins. The formation of β-turns plays an important role in protein folding, protein stability and molecular recognition processes. In this work we present the neural network method NetTurnP, for prediction of two-class β-turns and prediction of the individual β-turn types, by use of evolutionary information and predicted protein sequence features. It has been evaluated against a commonly used dataset BT426, and achieves a Matthews correlation coefficient of 0.50, which is the highest reported performance on a two-class prediction of β-turn and not-β-turn. Furthermore NetTurnP shows improved performance on some of the specific β-turn types. In the present work, neural network methods have been trained to predict β-turn or not and individual β-turn types from the primary amino acid sequence. The individual β-turn types I, I', II, II', VIII, VIa1, VIa2, VIba and IV have been predicted based on classifications by PROMOTIF, and the two-class prediction of β-turn or not is a superset comprised of all β-turn types. The performance is evaluated using a golden set of non-homologous sequences known as BT426. Our two-class prediction method achieves a performance of: MCC  = 0.50, Qtotal = 82.1%, sensitivity  = 75.6%, PPV  = 68.8% and AUC  = 0.864. We have compared our performance to eleven other prediction methods that obtain Matthews correlation coefficients in the range of 0.17 – 0.47. For the type specific β-turn predictions, only type I and II can be predicted with reasonable Matthews correlation coefficients, where we obtain performance values of 0.36 and 0.31, respectively. Conclusion The NetTurnP method has been implemented as a webserver, which is freely available at http://www.cbs.dtu.dk/services/NetTurnP/. NetTurnP is the only available webserver that allows submission of multiple sequences. PMID:21152409

  6. Experimental Study of Turning Temperature and Turning Vibration for the Tool of Different Wear State

    NASA Astrophysics Data System (ADS)

    Li, Shuncai; Yu, Qiu; Yuan, Guanlei; Liang, Li

    2018-03-01

    By a vibration test device and Vib’SYS analysis system, a three-dimensional piezoelectric acceleration sensor and an infrared thermometer and its collection system, the turning experiments under different spindle speeds were carried out on three cutting tools with different wear states, and the change law of cutting temperature at the tool tip and change law of three-dimensional vibration with turning time were obtained. The results indicate that: (1) The temperature of the initial wear tool and the middle wear tool under a small turning parameter increased slowly with turning time; while under a greater turning parameter, the temperature of the middle wear tool varies significantly with time; (2) The temperature of the severe wear tool increased sharply at the later feeding stage; (3) The change laws of the tools vibration acceleration maximum with the spindle speeds are similar for the initial wear tool and the middle wear tool, which shows a trend of increasing at first and then decreasing; (4) the average value of vibration acceleration self-power spectrum of severe wear tool constantly increase with the spindle speed; (5) the maximum impact is along the radial direction for the tools of different wear state.

  7. Infrared thermography based diagnosis of inter-turn fault and cooling system failure in three phase induction motor

    NASA Astrophysics Data System (ADS)

    Singh, Gurmeet; Naikan, V. N. A.

    2017-12-01

    Thermography has been widely used as a technique for anomaly detection in induction motors. International Electrical Testing Association (NETA) proposed guidelines for thermographic inspection of electrical systems and rotating equipment. These guidelines help in anomaly detection and estimating its severity. However, it focus only on location of hotspot rather than diagnosing the fault. This paper addresses two such faults i.e. inter-turn fault and failure of cooling system, where both results in increase of stator temperature. Present paper proposes two thermal profile indicators using thermal analysis of IRT images. These indicators are in compliance with NETA standard. These indicators help in correctly diagnosing inter-turn fault and failure of cooling system. The work has been experimentally validated for healthy and with seeded faults scenarios of induction motors.

  8. Hydrodynamics of Turning Flocks.

    PubMed

    Yang, Xingbo; Marchetti, M Cristina

    2015-12-18

    We present a hydrodynamic model of flocking that generalizes the familiar Toner-Tu equations to incorporate turning inertia of well-polarized flocks. The continuum equations controlled by only two dimensionless parameters, orientational inertia and alignment strength, are derived by coarse-graining the inertial spin model recently proposed by Cavagna et al. The interplay between orientational inertia and bend elasticity of the flock yields anisotropic spin waves that mediate the propagation of turning information throughout the flock. The coupling between spin-current density to the local vorticity field through a nonlinear friction gives rise to a hydrodynamic mode with angular-dependent propagation speed at long wavelengths. This mode becomes unstable as a result of the growth of bend and splay deformations augmented by the spin wave, signaling the transition to complex spatiotemporal patterns of continuously turning and swirling flocks.

  9. Predicting turns in proteins with a unified model.

    PubMed

    Song, Qi; Li, Tonghua; Cong, Peisheng; Sun, Jiangming; Li, Dapeng; Tang, Shengnan

    2012-01-01

    Turns are a critical element of the structure of a protein; turns play a crucial role in loops, folds, and interactions. Current prediction methods are well developed for the prediction of individual turn types, including α-turn, β-turn, and γ-turn, etc. However, for further protein structure and function prediction it is necessary to develop a uniform model that can accurately predict all types of turns simultaneously. In this study, we present a novel approach, TurnP, which offers the ability to investigate all the turns in a protein based on a unified model. The main characteristics of TurnP are: (i) using newly exploited features of structural evolution information (secondary structure and shape string of protein) based on structure homologies, (ii) considering all types of turns in a unified model, and (iii) practical capability of accurate prediction of all turns simultaneously for a query. TurnP utilizes predicted secondary structures and predicted shape strings, both of which have greater accuracy, based on innovative technologies which were both developed by our group. Then, sequence and structural evolution features, which are profile of sequence, profile of secondary structures and profile of shape strings are generated by sequence and structure alignment. When TurnP was validated on a non-redundant dataset (4,107 entries) by five-fold cross-validation, we achieved an accuracy of 88.8% and a sensitivity of 71.8%, which exceeded the most state-of-the-art predictors of certain type of turn. Newly determined sequences, the EVA and CASP9 datasets were used as independent tests and the results we achieved were outstanding for turn predictions and confirmed the good performance of TurnP for practical applications.

  10. Predicting Turns in Proteins with a Unified Model

    PubMed Central

    Song, Qi; Li, Tonghua; Cong, Peisheng; Sun, Jiangming; Li, Dapeng; Tang, Shengnan

    2012-01-01

    Motivation Turns are a critical element of the structure of a protein; turns play a crucial role in loops, folds, and interactions. Current prediction methods are well developed for the prediction of individual turn types, including α-turn, β-turn, and γ-turn, etc. However, for further protein structure and function prediction it is necessary to develop a uniform model that can accurately predict all types of turns simultaneously. Results In this study, we present a novel approach, TurnP, which offers the ability to investigate all the turns in a protein based on a unified model. The main characteristics of TurnP are: (i) using newly exploited features of structural evolution information (secondary structure and shape string of protein) based on structure homologies, (ii) considering all types of turns in a unified model, and (iii) practical capability of accurate prediction of all turns simultaneously for a query. TurnP utilizes predicted secondary structures and predicted shape strings, both of which have greater accuracy, based on innovative technologies which were both developed by our group. Then, sequence and structural evolution features, which are profile of sequence, profile of secondary structures and profile of shape strings are generated by sequence and structure alignment. When TurnP was validated on a non-redundant dataset (4,107 entries) by five-fold cross-validation, we achieved an accuracy of 88.8% and a sensitivity of 71.8%, which exceeded the most state-of-the-art predictors of certain type of turn. Newly determined sequences, the EVA and CASP9 datasets were used as independent tests and the results we achieved were outstanding for turn predictions and confirmed the good performance of TurnP for practical applications. PMID:23144872

  11. Epinephrine and left atrial and left ventricular diastolic function decrease in normal subjects.

    PubMed

    Fuenmayor, Abdel J; Solórzano, Moisés I; Gómez, Luisangelly

    2016-10-01

    We assessed the effect of epinephrine over left atrial and left ventricular diastolic function in subjects without structural heart disease. Twenty-seven, 34.6±17.2year-old patients without structural heart disease were included. Intravenous epinephrine (50 to 100ng/kg/min) was infused. Left atrial and ventricular functions were evaluated by means of echocardiography before and during the epinephrine infusion. No complications were observed. Significant increases in heart rate and systolic blood pressure were recorded. Both left atrial (minimal and maximal) volumes increased but increase in the minimal volume was more pronounced, and the ejection fraction diminished. Left atrial expansion index decreased and the fraction of left ventricular inflow volume resulting from atrial contraction increased. Two patients displayed abnormal left ventricular diastolic function. During epinephrine infusion, E/A and e' decreased, and isovolumetric relaxation time increased. In this group of young adults without structural heart disease, epinephrine infusion was safe, did not produce any complications, and induced a small but significant decrease in left atrial function and left ventricular diastolic function. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Improving the precision of linear optics measurements based on turn-by-turn beam position monitor data after a pulsed excitation in lepton storage rings

    NASA Astrophysics Data System (ADS)

    Malina, L.; Coello de Portugal, J.; Persson, T.; Skowroński, P. K.; Tomás, R.; Franchi, A.; Liuzzo, S.

    2017-08-01

    Beam optics control is of critical importance for machine performance and protection. Nowadays, turn-by-turn (TbT) beam position monitor (BPM) data are increasingly exploited as they allow for fast and simultaneous measurement of various optics quantities. Nevertheless, so far the best documented uncertainty of measured β -functions is of about 10‰ rms. In this paper we compare the β -functions of the ESRF storage ring measured from two different TbT techniques—the N-BPM and the Amplitude methods—with the ones inferred from a measurement of the orbit response matrix (ORM). We show how to improve the precision of TbT techniques by refining the Fourier transform of TbT data with properly chosen excitation amplitude. The precision of the N-BPM method is further improved by refining the phase advance measurement. This represents a step forward compared to standard TbT measurements. First experimental results showing the precision of β -functions pushed down to 4‰ both in TbT and ORM techniques are reported and commented.

  13. Upper-surface-blowing flow-turning performance

    NASA Technical Reports Server (NTRS)

    Sleeman, W. C., Jr.; Phelps, A. E., III

    1976-01-01

    Jet exhaust flow-turning characteristics were determined for systematic variations in upper-surface blowing exhaust nozzles and trailing-edge flap configuration variables from experimental wind-off (static) flow studies. For conditions with parallel flow exhausting from the nozzle, jet height (as indicated by nozzle exit height) and flap radius were found to be the most important parameters relating to flow turning. Nonparallel flow from the nozzle, as obtained from an internal roof angle and/or side spread angle, had a large favorable effect on flow turning. Comparisons made between static turning results and wind tunnel aerodynamic studies of identical configurations indicated that static flow-turning results can be indicative of wind-on powered lift performance for both good and poor nozzle-flap combinations but, for marginal designs, can lead to overly optimistic assessment of powered lift potential.

  14. rTMS stimulation on left DLPFC affects emotional cue retrieval as a function of anxiety level and gender.

    PubMed

    Balconi, Michela; Ferrari, Chiara

    2012-11-01

    Anxiety behaviour showed a consistent attentional bias toward negative and aversive memories, induced by a right dorsolateral prefrontal cortex (DLPFC) hyperactivation. In the present research, we explored the possible effect of rTMS (repeated transcranial magnetic stimulation) on the left DLPFC in memory retrieval of positive versus negative emotional words, to induce a balanced response between the two hemispheres. Moreover, the gender effect in emotional memory processing was verified as a function of the stimulus valence. Thirty subjects, who were divided in two different groups depending on their anxiety level (high/low anxiety, State-Trait-Anxiety Inventory (STAI)), were required to perform a task consisting of two experimental phases: an encoding phase (lists composed by positive and negative emotional words); and a retrieval phase (old stimuli and new stimuli to be recognized). We found that the rTMS stimulation over left DLPFC affects the memory retrieval. Specifically, high-anxiety subjects benefitted in greater measure to the frontal left stimulation with a reduced negative bias (increased accuracy and reduced response time (RT) for the positive stimuli). Whereas females showed a significant bias toward the negative memories, they did not benefit in greater measure to the TMS stimulation on the left hemisphere. These results suggested that left DLPFC activation favors the memory retrieval of positive emotional information and may limit the "unbalance effect" induced by a right frontal hemispheric superiority in high levels of anxiety. © 2012 Wiley Periodicals, Inc.

  15. The neural correlates of sex differences in left-right confusion.

    PubMed

    Hjelmervik, Helene; Westerhausen, René; Hirnstein, Marco; Specht, Karsten; Hausmann, Markus

    2015-06-01

    Difficulties in left-right discrimination (LRD) are commonly experienced in everyday life situations. Here we investigate the neurocognitive mechanisms of LRD and the specific role of left angular gyrus. Given that previous behavioral research reported women to be more susceptible to left-right confusion, the current study focuses particularly on the neural basis of sex differences in LRD while controlling for potential menstrual cycle effects (repeated measures design). 16 women and 15 men were presented pictures of pointing hands in various orientations (rotated versus non-rotated) and were asked to identify them as left or right hands. Results revealed that LRD was particularly associated with activation in inferior parietal regions, extending into the right angular gyrus. Irrespective of menstrual cycle phase, women, relative to men, recruited more prefrontal areas, suggesting higher top-down control in LRD. For the subset of rotated stimuli as compared to the non-rotated, we found leftward asymmetry for both men and women, although women scored significantly lower. We conclude that there are sex differences in the neurocognitive mechanisms underlying LRD. Although the angular gyrus is involved in LRD, several other parietal areas are at least as critical. Moreover, the hypothesis that more left-right confusion is due to more bilateral activation (in women) can be rejected. Copyright © 2015. Published by Elsevier Inc.

  16. Quantification of wing and body kinematics in connection to torque generation during damselfly yaw turn

    NASA Astrophysics Data System (ADS)

    Zeyghami, Samane; Bode-Oke, Ayodeji T.; Dong, HaiBo

    2017-01-01

    This study provides accurate measurements of the wing and body kinematics of three different species of damselflies in free yaw turn flights. The yaw turn is characterized by a short acceleration phase which is immediately followed by an elongated deceleration phase. Most of the heading change takes place during the latter stage of the flight. Our observations showed that yaw turns are executed via drastic rather than subtle changes in the kinematics of all four wings. The motion of the inner and outer wings were found to be strongly linked through their orientation as well as their velocities with the inner wings moving faster than the outer wings. By controlling the pitch angle and wing velocity, a damselfly adjusts the angle of attack. The wing angle of attack exerted the strongest influence on the yaw torque, followed by the flapping and deviation velocities of the wings. Moreover, no evidence of active generation of counter torque was found in the flight data implying that deceleration and stopping of the maneuver is dominated by passive damping. The systematic analysis carried out on the free flight data advances our understanding of the mechanisms by which these insects achieve their observed maneuverability. In addition, the inspiration drawn from this study can be employed in the design of low frequency flapping wing micro air vehicles (MAV's).

  17. Node and midline defects are associated with left-right development in Delta1 mutant embryos.

    PubMed

    Przemeck, Gerhard K H; Heinzmann, Ulrich; Beckers, Johannes; Hrabé de Angelis, Martin

    2003-01-01

    Axes formation is a fundamental process of early embryonic development. In addition to the anteroposterior and dorsoventral axes, the determination of the left-right axis is crucial for the proper morphogenesis of internal organs and is evolutionarily conserved in vertebrates. Genes known to be required for the normal establishment and/or maintenance of left-right asymmetry in vertebrates include, for example, components of the TGF-beta family of intercellular signalling molecules and genes required for node and midline function. We report that Notch signalling, which previously had not been implicated in this morphogenetic process, is required for normal left-right determination in mice. We show, that the loss-of-function of the delta 1 (Dll1) gene causes a situs ambiguous phenotype, including randomisation of the direction of heart looping and embryonic turning. The most probable cause for this left-right defect in Dll1 mutant embryos is a failure in the development of proper midline structures. These originate from the node, which is disrupted and deformed in Dll1 mutant embryos. Based on expression analysis in wild-type and mutant embryos, we suggest a model, in which Notch signalling is required for the proper differentiation of node cells and node morphology.

  18. Do Left- and Right-Handed People Have Similar Iron Deposition in the Basal Ganglia?

    PubMed

    Wang, Dan; Li, Yue-Hua; Wang, He

    2016-01-01

    This study aimed to investigate whether right-, left-, or mixed-handed people differ in terms of iron deposition using susceptibility weighted imaging in healthy subjects. A total of 87 people (right-handed, 51 subjects; left-handed, 19 subjects; mixed-handed, 17 subjects) aged 20 to 40 years participated. All underwent magnetic resonance examination, including conventional and susceptibility weighted imaging sequences. Phase images were used to quantify iron deposition in the head of the caudate nucleus and lenticular nucleus. The radian angle value was calculated and compared between the 3 (right-, left-, or mixed-handed) groups. There was no significant difference in the radian angle values between left-, right-, or mixed-handed people for either the right or left side of the caudate nucleus head. However, the amount of iron deposition in the left lenticular nucleus was significantly higher for right-handed than for the left-handed subjects (P < 0.001) and significantly higher for mixed-handed than for left-handed subjects (P = 0.006). In addition, the amount of iron deposition in the right lenticular nucleus was significantly lower for left-handed than for right-handed subjects (P < 0.001). The results revealed no significant differences in iron deposition in the head of the caudate nucleus. However, there was a significant difference in iron deposition in the lenticular nucleus between left- and right-handed subjects and between left- and mixed-handed subjects.

  19. Left arm underdevelopment secondary to an isolated left subclavian artery in tetralogy of Fallot.

    PubMed

    Carnero Alcázar, Manuel; Marianeschi, Stefano; Ruiz Alonso, Enrique; García Torres, Enrique; Comas, Juan V

    2010-02-01

    The anomalous origin of the left subclavian artery is known to be associated with right aortic arch and tetralogy of Fallot. In our case, the left subclavian artery arose from the left pulmonary artery. Therefore, the left arm was perfused by poorly oxygenated blood from pulmonary arteries and some retrograde vertebral artery flow. Thus, the left arm was cyanotic and less developed than the right one. The patient underwent surgical repair with complete correction of tetralogy of Fallot and reimplantation of the left subclavian artery to the left carotid artery. 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  20. 33 CFR 401.48 - Turning basins.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... 1—Opposite Brossard. (b) Turning Basin No. 2—Between Lock 7 and the Guard Gate Cut for vessels up to... vessels up to 107 m in overall length. (b) Turning Basin No. 2—Between Lock 7 and the Guard Gate Cut for...). (d) Turning Basin No. 4—North of Lock No. 8 for vessels up to 170 m in overall length. (e) For...

  1. 33 CFR 401.48 - Turning basins.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... 1—Opposite Brossard. (b) Turning Basin No. 2—Between Lock 7 and the Guard Gate Cut for vessels up to... vessels up to 107 m in overall length. (b) Turning Basin No. 2—Between Lock 7 and the Guard Gate Cut for...). (d) Turning Basin No. 4—North of Lock No. 8 for vessels up to 170 m in overall length. (e) For...

  2. Why Does Hair Turn Gray?

    MedlinePlus

    ... Videos for Educators Search English Español Why Does Hair Turn Gray? KidsHealth / For Kids / Why Does Hair Turn Gray? Print en español ¿Por qué se ... ever watched someone try to cover up gray hair by dyeing it? Or maybe you wonder why ...

  3. [Left-handedness and health].

    PubMed

    Milenković, Sanja; Belojević, Goran; Kocijancić, Radojka

    2010-01-01

    Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness. In the scientific literature left-handedness has been related to health disorders (spine deformities, immunological disorders, migraine, neurosis, depressive psychosis, schizophrenia, insomnia, homosexuality, diabetes mellitus, arterial hypertension, sleep apnea, enuresis nocturna and Down Syndrome), developmental disorders (autism, dislexia and sttutering) and traumatism. The most reliable scientific evidences have been published about the relationship between left-handedness and spinal deformities in school children in puberty and with traumatism in general population. The controversy of other results in up-to-now investigations of health aspects of left-handedness may partly be explained by a scientific disagreement whether writing with the left hand is a sufficient criterium for left-handedness, or is it necessary to investigate other parameters for laterality assessment. Explanation of health aspects of left-handedness is dominantly based on Geschwind-Galaburda model about "anomalous" cerebral domination, as a consequence of hormonal disbalance.

  4. Left Posterior Parietal Cortex Participates in Both Task Preparation and Episodic Retrieval

    PubMed Central

    Phillips, Jeffrey S.; Velanova, Katerina; Wolk, David A.; Wheeler, Mark E.

    2012-01-01

    Optimal memory retrieval depends not only on the fidelity of stored information, but also on the attentional state of the subject. Factors such as mental preparedness to engage in stimulus processing can facilitate or hinder memory retrieval. The current study used functional magnetic resonance imaging (fMRI) to distinguish preparatory brain activity before episodic and semantic retrieval tasks from activity associated with retrieval itself. A catch-trial imaging paradigm permitted separation of neural responses to preparatory task cues and memory probes. Episodic and semantic task preparation engaged a common set of brain regions, including the bilateral intraparietal sulcus (IPS), left fusiform gyrus (FG), and the pre-supplementary motor area (pre-SMA). In the subsequent retrieval phase, the left IPS was among a set of frontoparietal regions that responded differently to old and new stimuli. In contrast, the right IPS responded to preparatory cues with little modulation during memory retrieval. The findings support a strong left-lateralization of retrieval success effects in left parietal cortex, and further indicate that left IPS performs operations that are common to both task preparation and memory retrieval. Such operations may be related to attentional control, monitoring of stimulus relevance, or retrieval. PMID:19285142

  5. Transient left septal fascicular block and left anterior fascicular block as a consequence of proximal subocclusion of the left anterior descending coronary artery.

    PubMed

    Pérez-Riera, Andrés Ricardo; Barbosa-Barros, Raimundo; Daminello-Raimundo, Rodrigo; de Abreu, Luiz Carlos; Nikus, Kjell

    2018-04-19

    The association of left anterior fascicular block (LAFB) with left septal fascicular block (LSFB) characterizes a left bifascicular block subtype rarely described in the literature, probably due to the fact that most researchers are not aware of the existence of the left septal fascicle. We describe a case with this transient intraventricular dromotropic disturbance due to left anterior descending coronary artery subocclusion. © 2018 Wiley Periodicals, Inc.

  6. Prediction of beta-turns with learning machines.

    PubMed

    Cai, Yu-Dong; Liu, Xiao-Jun; Li, Yi-Xue; Xu, Xue-biao; Chou, Kuo-Chen

    2003-05-01

    The support vector machine approach was introduced to predict the beta-turns in proteins. The overall self-consistency rate by the re-substitution test for the training or learning dataset reached 100%. Both the training dataset and independent testing dataset were taken from Chou [J. Pept. Res. 49 (1997) 120]. The success prediction rates by the jackknife test for the beta-turn subset of 455 tetrapeptides and non-beta-turn subset of 3807 tetrapeptides in the training dataset were 58.1 and 98.4%, respectively. The success rates with the independent dataset test for the beta-turn subset of 110 tetrapeptides and non-beta-turn subset of 30,231 tetrapeptides were 69.1 and 97.3%, respectively. The results obtained from this study support the conclusion that the residue-coupled effect along a tetrapeptide is important for the formation of a beta-turn.

  7. Left atriotomy versus right atriotomy trans-septal approach for left atrial myxoma.

    PubMed

    Hatemi, A C; Gürsoy, M; Tongut, A; Kiliçkesmez, K; Karaoğlu, K; Küçükoğlu, S; Kansiz, E

    2010-01-01

    The biatrial approach has been the classic means of access for left atrial myxoma resection. Increased surgical experience led cardiac surgeons to favour the uniatrial approach to reduce incisions and achieve adequate exposure. In this study, two unilateral surgical approaches were compared in 18 consecutive left atrial myxoma cases. Patients were divided into two groups according to the surgical approach: left atriotomy (group 1, n = 9) and right atriotomy trans-septal approach (group 2, n = 9). Comparison criteria included pre- and post-operative functional capacity, cardiac rhythm, left ventricular ejection fraction, pulmonary artery pressure, left atrial dimensions, cardiopulmonary bypass time, aortic cross-clamp time, drainage over 48 h post-operatively, units of blood transfused, extubation time and length of stay in the intensive care unit and hospital. No significant between-group difference was observed in any criteria except aortic cross-clamp time, which was significantly longer in group 2 than in group 1. No recurrence of myxoma occurred in either group for the 15 patients followed up. Right atrial trans-septal incision appears to be as safe and effective as the left atriotomy approach for left atrial myxoma resection.

  8. Hypoplastic left heart syndrome

    MedlinePlus

    HLHS; Congenital heart - hypoplastic left heart; Cyanotic heart disease - hypoplastic left heart ... Hypoplastic left heart is a rare type of congenital heart disease. It is more common in males than in females. As ...

  9. Taking Turns

    ERIC Educational Resources Information Center

    Hopkins, Brian

    2010-01-01

    Two people take turns selecting from an even number of items. Their relative preferences over the items can be described as a permutation, then tools from algebraic combinatorics can be used to answer various questions. We describe each person's optimal selection strategies including how each could make use of knowing the other's preferences. We…

  10. An Experimental study of Corner Turning in a Granular Ammonium Nitrate Based Explosive

    NASA Astrophysics Data System (ADS)

    Sorber, Susan; Taylor, Peter

    2007-06-01

    A novel experimental geometry has been designed to perform controlled studies of corner turning in a ``tap density'' granular explosive. It enables the study of corner turning and detonation properties with high speed framing camera, piezo probes and ionization probes. The basic geometry consists of a large diameter PMMA cylinder filled with the granular explosive which is initiated on axis from below by a smaller diameter cylinder of the same explosive or a booster charge. Four experiments have been performed on a granular Ammonium Nitrate based non ideal explosive (NIE). Two experiments were initiated directly from a PE4 booster charge and two were initiated from a train including a booster charge and a 1'' diameter Copper cylinder containing the same NIE. Data from the four experiments was reproducible and observed detonation and shock waves showed good 2-D symmetry. Detonation phase velocity on the vertical side of the main container was observed and both shock and detonation velocities were observed in the corner turning region along the base of the main container. Analysis of the data shows that the booster initiated geometries with a higher input shock pressure into the NIE gave earlier detonation arrival at the lowest probes on the container side. The corner turning data is compared to a hydrocode calculation using a simple JWL++ reactive burn model.

  11. An Experimental Study of Corner Turning in a Granular Ammonium Nitrate Based Explosive

    NASA Astrophysics Data System (ADS)

    Sorber, S.; Taylor, P.; Burns, M.

    2007-12-01

    A novel experimental geometry has been designed to perform controlled studies of corner turning in a "tap density" granular explosive. It enables the study of corner turning and detonation properties with high speed framing camera, piezo probes and ionisation probes. The basic geometry consists of a large diameter PMMA cylinder filled with the granular explosive and is initiated on axis from below by a smaller diameter cylinder of granular explosive or a booster charge. Four experiments were performed on a granular Ammonium Nitrate based non-ideal explosive (NIE). Two experiments were initiated directly with the PE4 booster and two were initiated from a train including a booster charge and a 1″ diameter copper cylinder containing the same NIE. Experimental data from the four experiments was reproducible and the observed detonation and shock waves showed good 2-D symmetry. Detonation phase velocity on the vertical side of the main container was observed and both shock and detonation velocities were observed in the corner turning region along the base of the main container. Analysis of the data shows that the booster-initiated geometries with a higher input shock pressure into the granular explosive gave earlier detonation arrival at the lowest probes on the container side. The corner turning data is compared to a hydrocode calculation using a simple JWL++ reactive burn model.

  12. Seesaw at Lhc Through Left-Right Symmetry

    NASA Astrophysics Data System (ADS)

    Senjanović, Goran

    I argue that LHC may shed light on the nature of neutrino mass through the probe of the seesaw mechanism. The smoking gun signature is lepton number violation through the production of same sign lepton pairs, a collider analogy of the neutrinoless double beta decay. I discuss this in the context of left-right symmetric theories, which led originally to neutrino mass and the seesaw mechanism. A WR gauge boson with a mass in a few TeV region could easily dominate neutrinoless double beta decay, and its discovery at LHC would have spectacular signatures of parity restoration and lepton number violation. Moreover, LHC can measure the masses of the right-handed neutrinos and the right-handed leptonic mixing matrix, which could in turn be used to predict the rates for neutrinoless double decay and lepton flavor violating violating processes. The LR scale at the LHC energies offers great hope of observing these low energy processes in the present and upcoming experiments.

  13. The topological pressure-temperature phase diagram of fluoxetine nitrate: monotropy unexpectedly turning into enantiotropy

    NASA Astrophysics Data System (ADS)

    Céolin, René; Rietveld, Ivo B.

    2017-04-01

    The phase behavior of pharmaceuticals is important for regulatory requirements and dosage form development. Racemic fluoxetine nitrate possesses two crystalline forms for which initial measurements indicated that they have a monotropic relationship with form I the only stable form. By constructing the topological pressure-temperature phase diagram, it has been shown that unexpectedly form II has a stable domain in the phase diagram and can be easily obtained by heating and grinding. The pressure necessary to obtain form II is only 11 MPa, which is much lower than most pressure used for tableting in the pharmaceutical industry.

  14. Extension of the classical classification of β-turns

    PubMed Central

    de Brevern, Alexandre G.

    2016-01-01

    The functional properties of a protein primarily depend on its three-dimensional (3D) structure. These properties have classically been assigned, visualized and analysed on the basis of protein secondary structures. The β-turn is the third most important secondary structure after helices and β-strands. β-turns have been classified according to the values of the dihedral angles φ and ψ of the central residue. Conventionally, eight different types of β-turns have been defined, whereas those that cannot be defined are classified as type IV β-turns. This classification remains the most widely used. Nonetheless, the miscellaneous type IV β-turns represent 1/3rd of β-turn residues. An unsupervised specific clustering approach was designed to search for recurrent new turns in the type IV category. The classical rules of β-turn type assignment were central to the approach. The four most frequently occurring clusters defined the new β-turn types. Unexpectedly, these types, designated IV1, IV2, IV3 and IV4, represent half of the type IV β-turns and occur more frequently than many of the previously established types. These types show convincing particularities, in terms of both structures and sequences that allow for the classical β-turn classification to be extended for the first time in 25 years. PMID:27627963

  15. Extension of the classical classification of β-turns.

    PubMed

    de Brevern, Alexandre G

    2016-09-15

    The functional properties of a protein primarily depend on its three-dimensional (3D) structure. These properties have classically been assigned, visualized and analysed on the basis of protein secondary structures. The β-turn is the third most important secondary structure after helices and β-strands. β-turns have been classified according to the values of the dihedral angles φ and ψ of the central residue. Conventionally, eight different types of β-turns have been defined, whereas those that cannot be defined are classified as type IV β-turns. This classification remains the most widely used. Nonetheless, the miscellaneous type IV β-turns represent 1/3(rd) of β-turn residues. An unsupervised specific clustering approach was designed to search for recurrent new turns in the type IV category. The classical rules of β-turn type assignment were central to the approach. The four most frequently occurring clusters defined the new β-turn types. Unexpectedly, these types, designated IV1, IV2, IV3 and IV4, represent half of the type IV β-turns and occur more frequently than many of the previously established types. These types show convincing particularities, in terms of both structures and sequences that allow for the classical β-turn classification to be extended for the first time in 25 years.

  16. Upper Extremity Muscle Activity During In-Phase and Anti-Phase Continuous Pushing Tasks.

    PubMed

    Gruevski, Kristina M; Hodder, Joanne N; Keir, Peter J

    2017-11-01

    To determine the effect of anti-phase, in-phase bimanual and unimanual simulated industrial pushing tasks and frequency on upper extremity muscle activity. Research investigating symmetrical (in-phase) and asymmetrical (anti-phase) pushing exertions is limited despite a high prevalence in industry. Fifteen female participants completed five pushing tasks using a dual handle apparatus at three frequencies: 15 cycles per minute (cpm), 30 cpm, and self-selected. Tasks included two bimanual symmetrical pushes (constrained and unconstrained), two bimanual asymmetrical pushes (reciprocating and continuous), and one right unimanual push. Surface electromyography (EMG) from the right anterior, middle, and posterior deltoid (AD, MD, and PD); right and left trapezius (RT and LT); right pectoralis major (PM); and right and left external obliques (REO and LEO) was collected and normalized to maximum voluntary effort. There was a task by frequency interaction in the AD, MD, PD, and RT ( p < .005), where activity in AD, MD, and PD was highest in the continuous task at 15 cpm, but activity was similar across task in 30 cpm and self-selected. Muscle activity coefficient of variation was lowest during continuous task across all frequencies. Continuous, anti-phase pushes and constrained, in-phase pushes had the highest muscle activity demands and the least amount of variability in muscle activity and therefore may present the greatest risk of injury. Anti-phase pushing is known to have a greater cognitive demand, and this study demonstrated that it also has a greater physical demand when performed continuously.

  17. EEG Correlates of Preparatory Orienting, Contextual Updating, and Inhibition of Sensory Processing in Left Spatial Neglect.

    PubMed

    Lasaponara, Stefano; D'Onofrio, Marianna; Pinto, Mario; Dragone, Alessio; Menicagli, Dario; Bueti, Domenica; De Lucia, Marzia; Tomaiuolo, Francesco; Doricchi, Fabrizio

    2018-04-11

    Studies with event-related potentials have highlighted deficits in the early phases of orienting to left visual targets in right-brain-damaged patients with left spatial neglect (N+). However, brain responses associated with preparatory orienting of attention, with target novelty and with the detection of a match/mismatch between expected and actual targets (contextual updating), have not been explored in N+. Here in a study in healthy humans and brain-damaged patients of both sexes we demonstrate that frontal activity that reflects supramodal mechanisms of attentional orienting (Anterior Directing Attention Negativity, ADAN) is entirely spared in N+. In contrast, posterior responses that mark the early phases of cued orienting (Early Directing Attention Negativity, EDAN) and the setting up of sensory facilitation over the visual cortex (Late Directing Attention Positivity, LDAP) are suppressed in N+. This uncoupling is associated with damage of parietal-frontal white matter. N+ also exhibit exaggerated novelty reaction to targets in the right side of space and reduced novelty reaction for those in the left side (P3a) together with impaired contextual updating (P3b) in the left space. Finally, we highlight a drop in the amplitude and latency of the P1 that over the left hemisphere signals the early blocking of sensory processing in the right space when targets occur in the left one: this identifies a new electrophysiological marker of the rightward attentional bias in N+. The heterogeneous effects and spatial biases produced by localized brain damage on the different phases of attentional processing indicate relevant functional independence among their underlying neural mechanisms and improve the understanding of the spatial neglect syndrome. SIGNIFICANCE STATEMENT Our investigation answers important questions: are the different components of preparatory orienting (EDAN, ADAN, LDAP) functionally independent in the healthy brain? Is preparatory orienting of

  18. What Bed Size Does a Patient Need? The Relationship Between Body Mass Index and Space Required to Turn in Bed

    PubMed Central

    Wiggermann, Neal; Smith, Kathryn; Kumpar, Dee

    2017-01-01

    Background A bed that is too small to allow patients to turn from supine to side lying increases the difficulty of mobilizing patients, which can increase risk of musculoskeletal injury to caregivers, increase risk of pressure injuries to patients, and reduce patient comfort. Currently, no guidance is available for what patient sizes are accommodated by the standard 91cm (36 in.)-wide hospital bed, and no studies have evaluated the relationship between anthropometric attributes and space required to turn in bed. Objective The purpose of this research was to determine how much space individuals occupy when turning from supine to side lying as predicted by their anthropometry (i.e., body dimensions) to establish guidance on selecting the appropriate bed size. Methods Forty-seven adult participants (24 female) with body mass index (BMI) from 20 to 76 kg/m2 participated in a laboratory study. Body dimensions were measured, and the envelope of space required to turn was determined using motion capture. Linear regressions estimated the relationship between anthropometric attributes and space occupied when turning. Results BMI was strongly correlated (R2 = .88) with the space required to turn. Based on the linear regressions, individuals with BMI up to 35 kg/m2 could turn left and right within 91 cm and individuals with BMI up to 45 kg/m2 could turn one direction within 91 cm. Discussion BMI is a good predictor of the space required to turn from supine to lateral. Nurses should consider placing patients that are unable to laterally reposition themselves on a wider bed when BMI is greater than 35 kg/m2 and should consider placing all patients greater than 45 kg/m2 on a wider bed regardless of mobility. Hospital administrators can use historical demographic information about the BMI of their patient populations to plan facility-level equipment procurement for equipment that accommodates their patients. PMID:28968285

  19. Evaluating transportation systems management & operations (TSM&O) benefits to alternative intersection treatments.

    DOT National Transportation Integrated Search

    2015-12-01

    This research provides a comprehensive review and assessment of current alternative intersection methods : which successfully eliminate the left-turn phase. With increasing traffic and limited resources, the Florida : Department of Transportati...

  20. Incorporation of a Bio-Active Reverse-Turn Heterocycle into a Peptide Template Using Solid-Phase Synthesis to Probe Melanocortin Receptor Selectivity and Ligand Conformations by 2D 1H NMR

    PubMed Central

    Singh, Anamika; Wilczynski, Andrzej; Holder, Jerry R.; Witek, Rachel M.; Dirain, Marvin L.; Xiang, Zhimin; Edison, Arthur S.; Haskell-Luevano, Carrie

    2011-01-01

    Using a solid-phase synthetic approach, a bioactive reverse turn heterocyclic was incorporated into a cyclic peptide template to probe melanocortin receptor potency and ligand structural conformations. The five melanocortin receptor isoforms (MC1R-MC5R) are G-protein coupled receptors (GPCRs) that are regulated by endogenous agonists and antagonists. This pathway is involved in pigmentation, weight, and energy homeostasis. Herein, we report novel analogues of the chimeric AGRP-melanocortin peptide template integrated with a small molecule moiety to probe the structural and functional consequences of the core His-Phe-Arg-Trp peptide domain using a reverse-turn heterocycle. A series of six compounds are reported that result in inactive to full agonists with nM potency. Biophysical structural analysis [2D 1H NMR and computer-assisted molecular modeling (CAMM)] were performed on selected analogues, resulting in the identification that these peptide-small molecule hybrids possessed increased flexibility and fewer discrete conformational families as compared to the reference peptide and result in a novel template for further structure-function studies. PMID:21306168

  1. Accurate means of detecting and characterizing abnormal patterns of ventricular activation by phase image analysis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Botvinick, E.H.; Frais, M.A.; Shosa, D.W.

    1982-08-01

    The ability of scintigraphic phase image analysis to characterize patterns of abnormal ventricular activation was investigated. The pattern of phase distribution and sequential phase changes over both right and left ventricular regions of interest were evaluated in 16 patients with normal electrical activation and wall motion and compared with those in 8 patients with an artificial pacemaker and 4 patients with sinus rhythm with the Wolff-Parkinson-White syndrome and delta waves. Normally, the site of earliest phase angle was seen at the base of the interventricular septum, with sequential change affecting the body of the septum and the cardiac apex andmore » then spreading laterally to involve the body of both ventricles. The site of earliest phase angle was located at the apex of the right ventricle in seven patients with a right ventricular endocardial pacemaker and on the lateral left ventricular wall in one patient with a left ventricular epicardial pacemaker. In each case the site corresponded exactly to the position of the pacing electrode as seen on posteroanterior and left lateral chest X-ray films, and sequential phase changes spread from the initial focus to affect both ventricles. In each of the patients with the Wolff-Parkinson-White syndrome, the site of earliest ventricular phase angle was located, and it corresponded exactly to the site of the bypass tract as determined by endocardial mapping. In this way, four bypass pathways, two posterior left paraseptal, one left lateral and one right lateral, were correctly localized scintigraphically. On the basis of the sequence of mechanical contraction, phase image analysis provides an accurate noninvasive method of detecting abnormal foci of ventricular activation.« less

  2. 3. Log bunkhouse (far left), log chicken house (left of ...

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

    3. Log bunkhouse (far left), log chicken house (left of center), equipment shed (center), and workshop (far right). View to northwest. - William & Lucina Bowe Ranch, County Road 44, 0.1 mile northeast of Big Hole River Bridge, Melrose, Silver Bow County, MT

  3. DNA sequence selectivity of hairpin polyamide turn units

    PubMed Central

    Farkas, Michelle E.; Li, Benjamin C.; Dose, Christian; Dervan, Peter B.

    2011-01-01

    A class of hairpin polyamides linked by 3,4-diaminobutyric acid, resulting in a β-amine residue at the turn unit, showed improved binding affinities relative to their α-amino-γ-turn analogs for particular sequences. We incorporated β-amino-γ-turns in six-ring polyamides and determined whether there are any sequence preferences under the turn unit by quantitative footprinting titrations. Although there was an energetic penalty for G·C and C·G base pairs, we found little preference for T·A over A·T at the β-amino-γ-turn position. Fluorine and hydroxyl substituted α-amino-γ-turns were synthesized for comparison. Their binding affinities and specificities in the context of six-ring polyamides demonstrated overall diminished affinity and no additional specificity at the turn position. We anticipate that this study will be a baseline for further investigation of the turn subunit as a recognition element for the DNA minor groove. PMID:19349175

  4. Increasing protein stability by improving beta-turns.

    PubMed

    Fu, Hailong; Grimsley, Gerald R; Razvi, Abbas; Scholtz, J Martin; Pace, C Nick

    2009-11-15

    Our goal was to gain a better understanding of how protein stability can be increased by improving beta-turns. We studied 22 beta-turns in nine proteins with 66-370 residues by replacing other residues with proline and glycine and measuring the stability. These two residues are statistically preferred in some beta-turn positions. We studied: Cold shock protein B (CspB), Histidine-containing phosphocarrier protein, Ubiquitin, Ribonucleases Sa2, Sa3, T1, and HI, Tryptophan synthetase alpha-subunit, and Maltose binding protein. Of the 15 single proline mutations, 11 increased stability (Average = 0.8 +/- 0.3; Range = 0.3-1.5 kcal/mol), and the stabilizing effect of double proline mutants was additive. On the basis of this and our previous work, we conclude that proteins can generally be stabilized by replacing nonproline residues with proline residues at the i + 1 position of Type I and II beta-turns and at the i position in Type II beta-turns. Other turn positions can sometimes be used if the phi angle is near -60 degrees for the residue replaced. It is important that the side chain of the residue replaced is less than 50% buried. Identical substitutions in beta-turns in related proteins give similar results. Proline substitutions increase stability mainly by decreasing the entropy of the denatured state. In contrast, the large, diverse group of proteins considered here had almost no residues in beta-turns that could be replaced by Gly to increase protein stability. Improving beta-turns by substituting Pro residues is a generally useful way of increasing protein stability. 2009 Wiley-Liss, Inc.

  5. INCREASING PROTEIN STABILITY BY IMPROVING BETA-TURNS

    PubMed Central

    Fu, Hailong; Grimsley, Gerald R.; Razvi, Abbas; Scholtz, J. Martin; Pace, C. Nick

    2009-01-01

    Our goal was to gain a better understanding of how protein stability can be increased by improving β-turns. We studied 22 β-turns in nine proteins with 66 to 370 residues by replacing other residues with proline and glycine and measuring the stability. These two residues are statistically preferred in some β-turn positions. We studied: Cold shock protein B (CspB), Histidine-containing phosphocarrier protein (HPr), Ubiquitin, Ribonucleases Sa2, Sa3, T1, and HI, Tryptophan synthetase α-subunit (TSα), and Maltose binding protein (MBP). Of the fifteen single proline mutations, 11increased stability (Average = 0.8 ± 0.3; Range = 0.3 – 1.5 kcal/mol), and the stabilizing effect of double proline mutants was additive. Based on this and our previous work, we conclude that proteins can generally be stabilized by replacing non-proline residues with proline residues at the i + 1 position of Type I and II β-turns and at the i position in Type II β-turns. Other turn positions can sometimes be used if the φ angle is near −60° for the residue replaced. It is important that the side chain of the residue replaced is less than 50% buried. Identical substitutions in β-turns in related proteins give similar results. Proline substitutions increase stability mainly by decreasing the entropy of the denatured state. In contrast, the large, diverse group of proteins considered here had almost no residues in β-turns that could be replaced by Gly to increase protein stability. Improving β-turns by substituting Pro residues is a generally useful way of increasing protein stability. PMID:19626709

  6. Surgical management of the left superior vena cava draining into the left atrium: a novel off-pump technique using the left atrial appendage

    PubMed Central

    Boutayeb, Alaae; Marmade, Lahcen; Bensouda, Adil; Moughil, Said

    2012-01-01

    The left superior vena cava is the most common congenital venous anomaly in the chest; however, its drainage into the left atrium is exceptional. The aim of the paper is to describe our novel technique to connect the left superior vena cava to the right cavities using the left atrial appendage, without cardiopulmonary bypass. PMID:22802356

  7. Utilizing the N beam position monitor method for turn-by-turn optics measurements

    NASA Astrophysics Data System (ADS)

    Langner, A.; Benedetti, G.; Carlà, M.; Iriso, U.; Martí, Z.; de Portugal, J. Coello; Tomás, R.

    2016-09-01

    The N beam position monitor method (N -BPM) which was recently developed for the LHC has significantly improved the precision of optics measurements that are based on BPM turn-by-turn data. The main improvement is due to the consideration of correlations for statistical and systematic error sources, as well as increasing the amount of BPM combinations which are used to derive the β -function at one location. We present how this technique can be applied at light sources like ALBA, and compare the results with other methods.

  8. Flow and Heat Transfer in 180-Degree Turn Square Ducts: Effects of Turning Configuration and System Rotation

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See; Chyu, Ming-King

    1993-01-01

    Forced flow through channels connected by sharp bends is frequently encountered in various rocket and gas turbine engines. For example, the transfer ducts, the coolant channels surround the combustion chamber, the internal cooling passage in a blade or vane, the flow path in the fuel element of a nuclear rocket engine, the flow around a pressure relieve valve piston, and the recirculated base flow of multiple engine clustered nozzles. Transport phenomena involved in such a flow passage are complex and considered to be very different from those of conventional turning flow with relatively mild radii of curvature. While previous research pertaining to this subject has been focused primarily on the experimental heat transfer, very little analytical work is directed to understanding the flowfield and energy transport in the passage. Therefore, the primary goal of this paper is to benchmark the predicted wall heat fluxes using a state-of-the-art computational fluid dynamics (CFD) formulation against those of measurement for a rectangular turn duct. Other secondary goals include studying the effects of turning configurations, e.g., the semi-circular turn, and the rounded-corner turn, and the effect of system rotation. The computed heat fluxes for the rectangular turn duct compared favorably with those of the experimental data. The results show that the flow pattern, pressure drop, and heat transfer characteristics are different among the three turning configurations, and are substantially different with system rotation. Also demonstrated in this work is that the present computational approach is quite effective and efficient and will be suitable for flow and thermal modeling in rocket and turbine engine applications.

  9. Reticular lamina and basilar membrane vibrations in the basal turn of gerbil and mouse cochleae

    NASA Astrophysics Data System (ADS)

    Ren, Tianying; He, Wenxuan

    2018-05-01

    Low-coherence interferometry in living cochleae has provided valuable information for understanding cochlear micromechanics. A recent measurement of the reticular lamina and basilar membrane vibrations in mouse cochleae, however, is inconsistent with data collected from guinea pig cochleae. To determine whether a species difference accounts for the observed difference, a custom-built heterodyne low-coherence interferometer was used to measure reticular lamina and basilar membrane vibrations at the basal turn of sensitive gerbil and mouse cochleae. For the gerbil and mouse, both the reticular lamina and basilar membrane vibrations show sharp tuning and nonlinear compressive growth near the best frequency. The magnitude of the reticular lamina vibration is significantly greater than that of the basilar membrane vibration not only near the best frequency, but also at low frequencies. The phase of the reticular lamina vibration leads the basilar membrane phase by up to 180-degrees at low frequencies, and this phase lead decreases with frequency, approaching zero near the best frequency. The best frequency of the reticular lamina and basilar membrane vibrations at the cochlear basal turn in mice is significantly higher than that in gerbils. Besides this difference, cochlear micromechanical responses in the gerbil are similar to those in the mouse. Thus, the current results indicate that gerbil and mouse cochleae detect and process sounds likely through a similar micromechanical mechanism.

  10. 6. Livestock barn (far left), log drafthorse barn (left of ...

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

    6. Livestock barn (far left), log draft-horse barn (left of center), loafing shed (center), log calving barn (right of center). View to west-northwest. - William & Lucina Bowe Ranch, County Road 44, 0.1 mile northeast of Big Hole River Bridge, Melrose, Silver Bow County, MT

  11. Repair of aorto-left ventricular tunnel arising from the left sinus of valsalva.

    PubMed

    Nezafati, Mohammad Hassan; Maleki, Mahmood Hosseinzadeh; Javan, Hadi; Zirak, Nahid

    2010-05-01

    Aortico-left ventricular tunnel (ALVT) is a rare congenital cardiac defect that bypasses the aortic valve via a para-valvular connection from the left ventricle to the aorta. In most cases, the tunnel arises from the right aortic sinus. In this case report, we are presenting a case of ALVT, of which the aortic orifice arose from the left aortic sinus, requiring special attention to avoid the left coronary artery injury at the time of surgical repair.

  12. Anticipation in turn-taking: mechanisms and information sources.

    PubMed

    Riest, Carina; Jorschick, Annett B; de Ruiter, Jan P

    2015-01-01

    During conversations participants alternate smoothly between speaker and hearer roles with only brief pauses and overlaps. There are two competing types of accounts about how conversationalists accomplish this: (a) the signaling approach and (b) the anticipatory ('projection') approach. We wanted to investigate, first, the relative merits of these two accounts, and second, the relative contribution of semantic and syntactic information to the timing of next turn initiation. We performed three button-press experiments using turn fragments taken from natural conversations to address the following questions: (a) Is turn-taking predominantly based on anticipation or on reaction, and (b) what is the relative contribution of semantic and syntactic information to accurate turn-taking. In our first experiment we gradually manipulated the information available for anticipation of the turn end (providing information about the turn end in advance to completely removing linguistic information). The results of our first experiment show that the distribution of the participants' estimation of turn-endings for natural turns is very similar to the distribution for pure anticipation. We conclude that listeners are indeed able to anticipate a turn-end and that this strategy is predominantly used in turn-taking. In Experiment 2 we collected purely reacted responses. We used the distributions from Experiments 1 and 2 together to estimate a new dependent variable called Reaction Anticipation Proportion. We used this variable in our third experiment where we manipulated the presence vs. absence of semantic and syntactic information by low-pass filtering open-class and closed class words in the turn. The results suggest that for turn-end anticipation, both semantic and syntactic information are needed, but that the semantic information is a more important anticipation cue than syntactic information.

  13. Anticipation in turn-taking: mechanisms and information sources

    PubMed Central

    Riest, Carina; Jorschick, Annett B.; de Ruiter, Jan P.

    2015-01-01

    During conversations participants alternate smoothly between speaker and hearer roles with only brief pauses and overlaps. There are two competing types of accounts about how conversationalists accomplish this: (a) the signaling approach and (b) the anticipatory (‘projection’) approach. We wanted to investigate, first, the relative merits of these two accounts, and second, the relative contribution of semantic and syntactic information to the timing of next turn initiation. We performed three button-press experiments using turn fragments taken from natural conversations to address the following questions: (a) Is turn-taking predominantly based on anticipation or on reaction, and (b) what is the relative contribution of semantic and syntactic information to accurate turn-taking. In our first experiment we gradually manipulated the information available for anticipation of the turn end (providing information about the turn end in advance to completely removing linguistic information). The results of our first experiment show that the distribution of the participants’ estimation of turn-endings for natural turns is very similar to the distribution for pure anticipation. We conclude that listeners are indeed able to anticipate a turn-end and that this strategy is predominantly used in turn-taking. In Experiment 2 we collected purely reacted responses. We used the distributions from Experiments 1 and 2 together to estimate a new dependent variable called Reaction Anticipation Proportion. We used this variable in our third experiment where we manipulated the presence vs. absence of semantic and syntactic information by low-pass filtering open-class and closed class words in the turn. The results suggest that for turn-end anticipation, both semantic and syntactic information are needed, but that the semantic information is a more important anticipation cue than syntactic information. PMID:25699004

  14. Bodily-visual practices and turn continuation

    PubMed Central

    Ford, Cecilia E.; Thompson, Sandra A.; Drake, Veronika

    2012-01-01

    This paper considers points in turn construction where conversation researchers have shown that talk routinely continues beyond possible turn completion, but where we find bodily-visual behavior doing such turn extension work. The bodily-visual behaviors we examine share many features with verbal turn extensions, but we argue that embodied movements have distinct properties that make them well-suited for specific kinds of social action, including stance display and by-play in sequences framed as subsidiary to a simultaneous and related verbal exchange. Our study is in line with a research agenda taking seriously the point made by Goodwin (2000a, b, 2003), Hayashi (2003, 2005), Iwasaki (2009), and others that scholars seeking to account for practices in language and social interaction do themselves a disservice if they privilege the verbal dimension; rather, as suggested in Stivers/Sidnell (2005), each semiotic system/modality, while coordinated with others, has its own organization. With the current exploration of bodily-visual turn extensions, we hope to contribute to a growing understanding of how these different modes of organization are managed concurrently and in concert by interactants in carrying out their everyday social actions. PMID:23526861

  15. Sharp turning and corner turning: comparison of energy expenditure, gait parameters, and level of fatigue among community-dwelling elderly.

    PubMed

    Justine, Maria; Manaf, Haidzir; Sulaiman, Affeenddie; Razi, Shahir; Alias, Hani Asilah

    2014-01-01

    This study compares energy expenditure (EE), gait parameters (GP), and level of fatigue (LOF) between 5-minute walking with sharp turning (ST) and corner turning (CT). Data were obtained from 29 community-dwelling elderly (mean age, 62.7 ± 3.54 years). For 5 minutes, in ST task, participants walked on a 3-meter pathway with 2 cones placed at each end (180° turning), while in CT task, participants walked on a 6-meter pathway with 4 cones placed at 4 corners (90° turning). The physiological cost index, pedometer, and 10-point Modified Borg Dyspnoea Scale were used to measure EE (beats/min), GP (no of steps), and LOF, respectively. Data were analyzed by using independent t-tests. EE during ST (0.62 ± 0.21 beats/min) was significantly higher than CT (0.48 ± 0.17 beats/min) (P < 0.05). GP (434 ± 92.93 steps) and LOF (1.40 ± 1.11) in ST were found to be lower compared to GP (463 ± 92.18 steps) and LOF (1.54 ± 1.34) in CT (All, P > 0.05). Higher EE in ST could be due to the difficulty in changing to a 180° direction, which may involve agility and different turning strategies (step-turn or pivot-turn) to adjust the posture carefully. In CT, participants could choose a step-turn strategy to change to a 90° direction, which was less challenging to postural control.

  16. What's Left of the Left-Right Dimension? Why the Economic Policy Positions of Europeans Do Not Fit the Left-Right Dimension.

    PubMed

    Otjes, Simon

    2018-01-01

    In political science the economic left-right dimension plays a central role. A growing body of evidence shows that the economic policy preferences of a large segment of citizens do not scale sufficiently. Using Mokken scale analysis, this study determines the causes of this phenomenon. Differences in the extent to which the economic policy preferences of citizens fit the left-right dimension can be explained in terms of the interaction between individual level and political system-level variables: citizens who spend more attention to politicians with views that conform to the left-right dimension, have views that conform to the left-right dimension. There is also a role for the legacy of communist dictatorship: citizens who were socialised in democratic countries have views that fit the left-right dimension better than those socialised during communism.

  17. Anatomic relationship between left coronary artery and left atrium in patients undergoing atrial fibrillation ablation.

    PubMed

    Anselmino, Matteo; Torri, Federica; Ferraris, Federico; Calò, Leonardo; Castagno, Davide; Gili, Sebastiano; Rovera, Chiara; Giustetto, Carla; Gaita, Fiorenzo

    2017-07-01

    Atrial fibrillation transcatheter ablation (TCA) is, within available atrial fibrillation rhythm control strategies, one of the most effective. To potentially improve ablation outcome in case of recurrent atrial fibrillation after a first procedure or in presence of structural myocardial disease, isolation of the pulmonary veins may be associated with extensive lesions within the left atrium. To avoid rare, but potentially life-threatening, complications, thorough knowledge and assessment of left atrium anatomy and its relation to structures in close proximity are, therefore, mandatory. Aim of the present study is to describe, by cardiac computed tomography, the anatomic relationship between aortic root, left coronary artery and left atrium in patients undergoing atrial fibrillation TCA. The cardiac computed tomography scan of 21 patients affected by atrial fibrillation was elaborated to segment left atrium, aortic root and left coronary artery from the surrounding structures and the following distances measured: left atrium and aortic root; left atrium roof and aortic root; left main coronary artery and left atrium; circumflex artery and left atrium appendage; and circumflex artery and mitral valve annulus. Above all, the median distance between left atrium and aortic root (1.9, 1.5-2.1 mm), and between circumflex artery and left atrium appendage ostium (3.0, 2.1-3.4 mm) were minimal (≤3 mm). None of measured distances significantly varied between patients presenting paroxysmal versus persistent atrial fibrillation. The anatomic relationship between left atrium and coronary arteries is extremely relevant when performing atrial fibrillation TCA by extensive lesions. Therefore, at least in the latter case, preablation imaging should be recommended to avoid rare, but potentially life-threatening, complications with the aim of an as well tolerated as possible procedure.

  18. 1. Postandbeam garage (far left), oneroom log cabin (left of ...

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

    1. Post-and-beam garage (far left), one-room log cabin (left of center), house (right of center), garden shed and outhouse (far right). View to west-southwest. - William & Lucina Bowe Ranch, County Road 44, 0.1 mile northeast of Big Hole River Bridge, Melrose, Silver Bow County, MT

  19. Dynamic CT for parathyroid disease: are multiple phases necessary?

    PubMed

    Raghavan, P; Durst, C R; Ornan, D A; Mukherjee, S; Wintermark, M; Patrie, J T; Xin, W; Shada, A L; Hanks, J B; Smith, P W

    2014-10-01

    A 4D CT protocol for detection of parathyroid lesions involves obtaining unenhanced, arterial, early, and delayed venous phase images. The aim of the study was to determine the ideal combination of phases that would minimize radiation dose without sacrificing diagnostic accuracy. With institutional review board approval, the records of 29 patients with primary hyperparathyroidism who had undergone surgical exploration were reviewed. Four neuroradiologists who were blinded to the surgical outcome reviewed the imaging studies in 5 combinations (unenhanced and arterial phase; unenhanced, arterial, and early venous; all 4 phases; arterial alone; arterial and early venous phases) with an interval of at least 7 days between each review. The accuracy of interpretation in lateralizing an abnormality to the side of the neck (right, left, ectopic) and localizing it to a quadrant in the neck (right or left upper, right or left lower) was evaluated. The lateralization and localization accuracy (90.5% and 91.5%, respectively) of the arterial phase alone was comparable with the other combinations of phases. There was no statistically significant difference among the different combinations of phases in their ability to lateralize or localize adenomas to a quadrant (P = .976 and .996, respectively). Assessment of a small group of patients shows that adequate diagnostic accuracy for parathyroid adenoma localization may be achievable by obtaining arterial phase images alone. If this outcome can be validated prospectively in a larger group of patients, then the radiation dose can potentially be reduced to one-fourth of what would otherwise be administered. © 2014 by American Journal of Neuroradiology.

  20. PHOTOGRAPHER: KSC The first solid rocket booster solid motor segemnts to arrive at KSC, the left and

    NASA Technical Reports Server (NTRS)

    1980-01-01

    PHOTOGRAPHER: KSC The first solid rocket booster solid motor segemnts to arrive at KSC, the left and right hand aft segments are off-loaded into High Bay 4 in the Vehicle Assembly Building and mated to their respective SRB aft skirts. The two aft assemblies will support the entire 150 foot tall solid boosters, in turn supporting the external tank and Orbiter Columbia on the Mobile Launcher Platform, for the first orbital flight test of the Space Shuttle.

  1. Photographer: KSC The first solid rocket booster solid motor segemnts to arrive at KSC, the left and

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Photographer: KSC The first solid rocket booster solid motor segemnts to arrive at KSC, the left and right hand aft segments are off-loaded into High Bay 4 in the Vehicle Assembly Building and mated to their respective SRB aft skirts. The two aft assemblies will support the entire 150 foot tall solid boosters, in turn supporting the external tank and Orbiter Columbia on the Mobile Launcher Platform, for the first orbital flight test of the Space Shuttle.

  2. Phase diagram of two-dimensional hard ellipses.

    PubMed

    Bautista-Carbajal, Gustavo; Odriozola, Gerardo

    2014-05-28

    We report the phase diagram of two-dimensional hard ellipses as obtained from replica exchange Monte Carlo simulations. The replica exchange is implemented by expanding the isobaric ensemble in pressure. The phase diagram shows four regions: isotropic, nematic, plastic, and solid (letting aside the hexatic phase at the isotropic-plastic two-step transition [E. P. Bernard and W. Krauth, Phys. Rev. Lett. 107, 155704 (2011)]). At low anisotropies, the isotropic fluid turns into a plastic phase which in turn yields a solid for increasing pressure (area fraction). Intermediate anisotropies lead to a single first order transition (isotropic-solid). Finally, large anisotropies yield an isotropic-nematic transition at low pressures and a high-pressure nematic-solid transition. We obtain continuous isotropic-nematic transitions. For the transitions involving quasi-long-range positional ordering, i.e., isotropic-plastic, isotropic-solid, and nematic-solid, we observe bimodal probability density functions. This supports first order transition scenarios.

  3. Right-Turn Lanes

    DOT National Transportation Integrated Search

    1996-05-01

    The following topics are the subjects of this discussion paper. : 1. Should right-turn deceleration lanes be provided? On Oregon : highways? If so, what warrants are to be used? When, if : provided, how should the length be determined? : 2. Should ri...

  4. Quantum phase transitions in the noncommutative Dirac oscillator

    NASA Astrophysics Data System (ADS)

    Panella, O.; Roy, P.

    2014-10-01

    We study the (2 + 1)-dimensional Dirac oscillator in a homogeneous magnetic field in the noncommutative plane. It is shown that the effect of noncommutativity is twofold: (i) momentum noncommuting coordinates simply shift the critical value (Bcr) of the magnetic field at which the well known left-right chiral quantum phase transition takes place (in the commuting phase); (ii) noncommutativity in the space coordinates induces a new critical value of the magnetic field, Bcr*, where there is a second quantum phase transition (right-left): this critical point disappears in the commutative limit. The change in chirality associated with the magnitude of the magnetic field is examined in detail for both critical points. The phase transitions are described in terms of the magnetization of the system. Possible applications to the physics of silicene and graphene are briefly discussed.

  5. Mapping of the left-sided phrenic nerve course in patients undergoing left atrial catheter ablations.

    PubMed

    Huemer, Martin; Wutzler, Alexander; Parwani, Abdul S; Attanasio, Philipp; Haverkamp, Wilhelm; Boldt, Leif-Hendrik

    2014-09-01

    Catheter ablation of atrial fibrillation has been associated with left-sided phrenic nerve palsy. Knowledge of the individual left phrenic nerve course therefore is essential to prevent nerve injury. The aim of this study was to test the feasibility of an intraprocedural pace mapping and reconstruction of the left phrenic nerve course and to characterize which anatomical areas are affected. In patients undergoing left atrial catheter ablation, a three-dimensional map of the left atrial anatomical structures was created. The left-sided phrenic nerve course was determined by high-output pace mapping and reconstructed in the map. In this study, 40 patients with atrial fibrillation or atrial tachycardias were included. Left phrenic nerve capture was observed in 23 (57.5%) patients. Phrenic nerve was captured in 22 (55%) patients inside the left atrial appendage, in 22 (55%) in distal parts, in 21 (53%) in medial parts, and in two (5%) in ostial parts of the appendage. In three (7.5%) patients, capture was found in the distal coronary sinus and in one (2.5%) patient in the left atrium near the left atrial appendage ostium. Ablation target was changed due to direct spatial relationship to the phrenic nerve in three (7.5%) patients. No phrenic nerve palsy was observed. Left-sided phrenic nerve capture was found inside and around the left atrial appendage in the majority of patients and additionally in the distal coronary sinus. Phrenic nerve mapping and reconstruction can easily be performed and should be considered prior catheter ablations in potential affected areas. ©2014 Wiley Periodicals, Inc.

  6. Validation of PEP-II Resonantly Excited Turn-by-Turn BPM Data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yan, Yiton T.; Cai, Yunhai; Colocho, William.

    2007-06-28

    For optics measurement and modeling of the PEP-II electron (HER) and position (LER) storage rings, we have been doing well with MIA [1] which requires analyzing turn-by-turn Beam Position Monitor (BPM) data that are resonantly excited at the horizontal, vertical, and longitudinal tunes. However, in anticipation that certain BPM buttons and even pins in the PEP-II IR region would be missing for the run starting in January 2007, we had been developing a data validation process to reduce the effect due to the reduced BPM data accuracy on PEP-II optics measurement and modeling. Besides the routine process for ranking BPMmore » noise level through data correlation among BPMs with a singular-value decomposition (SVD), we could also check BPM data symplecticity by comparing the invariant ratios. Results from PEP-II measurement will be presented.« less

  7. Turning for Ulcer Reduction (TURN) Study: An Economic Analysis.

    PubMed

    Paulden, Mike; Bergstrom, Nancy; Horn, Susan D; Rapp, Mary; Stern, Anita; Barrett, Ryan; Watkiss, Michael; Krahn, Murray

    2014-01-01

    The Turning for Ulcer Reduction (TURN) study was a multisite, randomized controlled trial that aimed to determine the optimal frequency of turning nursing facility residents with mobility limitations who are at moderate and high risk for pressure ulcer (PrU) development. Here we present data from the economic analysis. This economic analysis aims to estimate the economic consequences for Ontario of switching from a repositioning schedule of 2-hour intervals to a schedule of 3-hour or 4-hour intervals. Costs considered in the analysis included those associated with nursing staff time spent repositioning residents and with incontinent care supplies, which included briefs, barrier cream, and washcloths. The total economic benefit of switching to 3-hour or 4-hour repositioning is estimated to be $11.05 or $16.74 per day, respectively, for every resident at moderate or high risk of developing PrUs. For a typical facility with 123 residents, 41 (33%) of whom are at moderate or high risk of developing PrUs, the total economic benefit is estimated to be $453 daily for 3-hour or $686 daily for 4-hour repositioning. For Ontario as a whole, assuming that there are 77,933 residents at 634 LTC facilities, 25,927 (33%) of whom are at moderate or high risk of developing PrUs, the total economic benefits of switching to 3-hour or 4-hour repositioning are estimated to be $286,420 or $433,913 daily, respectively, equivalent to $104.5 million or $158.4 million per year. We did not consider the savings the Ontario Ministry of Health and Long-Term Care might incur should less frequent repositioning reduce the incidence of work-related injury among nursing staff, so our findings are potentially conservative. A switch to 3-hour or 4-hour repositioning appears likely to yield substantial economic benefits to Ontario without placing residents at greater risk of developing PrUs.

  8. Turning for Ulcer Reduction (TURN) Study: An Economic Analysis

    PubMed Central

    Paulden, Mike; Bergstrom, Nancy; Horn, Susan D.; Rapp, Mary; Stern, Anita; Barrett, Ryan; Watkiss, Michael; Krahn, Murray

    2014-01-01

    Background The Turning for Ulcer Reduction (TURN) study was a multisite, randomized controlled trial that aimed to determine the optimal frequency of turning nursing facility residents with mobility limitations who are at moderate and high risk for pressure ulcer (PrU) development. Here we present data from the economic analysis. Objectives This economic analysis aims to estimate the economic consequences for Ontario of switching from a repositioning schedule of 2-hour intervals to a schedule of 3-hour or 4-hour intervals. Data Sources Costs considered in the analysis included those associated with nursing staff time spent repositioning residents and with incontinent care supplies, which included briefs, barrier cream, and washcloths. Results The total economic benefit of switching to 3-hour or 4-hour repositioning is estimated to be $11.05 or $16.74 per day, respectively, for every resident at moderate or high risk of developing PrUs. For a typical facility with 123 residents, 41 (33%) of whom are at moderate or high risk of developing PrUs, the total economic benefit is estimated to be $453 daily for 3-hour or $686 daily for 4-hour repositioning. For Ontario as a whole, assuming that there are 77,933 residents at 634 LTC facilities, 25,927 (33%) of whom are at moderate or high risk of developing PrUs, the total economic benefits of switching to 3-hour or 4-hour repositioning are estimated to be $286,420 or $433,913 daily, respectively, equivalent to $104.5 million or $158.4 million per year. Limitations We did not consider the savings the Ontario Ministry of Health and Long-Term Care might incur should less frequent repositioning reduce the incidence of work-related injury among nursing staff, so our findings are potentially conservative. Conclusions A switch to 3-hour or 4-hour repositioning appears likely to yield substantial economic benefits to Ontario without placing residents at greater risk of developing PrUs. PMID:26330894

  9. Turning crocodilian hearts into bird hearts: growth rates are similar for alligators with and without right-to-left cardiac shunt

    PubMed Central

    Eme, John; Gwalthney, June; Owerkowicz, Tomasz; Blank, Jason M.; Hicks, James W.

    2010-01-01

    The functional and possible adaptive significance of non-avian reptiles' dual aortic arch system and the ability of all non-avian reptiles to perform central vascular cardiac shunts have been of great interest to comparative physiologists. The unique cardiac anatomy of crocodilians – a four-chambered heart with the dual aortic arch system – allows for only right-to-left (R–L; pulmonary bypass) cardiac shunt and for surgical elimination of this shunt. Surgical removal of the R–L shunt, by occluding the left aorta (LAo) upstream and downstream of the foramen of Panizza, results in a crocodilian with an obligatory, avian/mammalian central circulation. In this study, R–L cardiac shunt was eliminated in age-matched, female American alligators (Alligator mississippiensis; 5–7 months of age). We tested the hypothesis that surgical elimination of R–L cardiac shunt would impair growth (a readily measured proxy for fitness) compared with sham-operated, age-matched controls, especially in animals subjected to exhaustive exercise. While regular exercise caused a decrease in size (snout-to-vent length, head length and body mass), elimination of the capacity for R–L cardiac shunt did not greatly reduce animal growth, despite a chronic ventricular enlargement in surgically altered juvenile alligators. We speculate that, despite being slightly smaller, alligators with an occluded LAo would have reached sexual maturity in the same breeding season as control alligators. This study suggests that crocodilian R–L cardiac shunt does not provide an adaptive advantage for juvenile alligator growth and supports the logic that cardiac shunts persist in crocodilians because they have not been selected against. PMID:20639429

  10. Temperature-dependent inotropic and lusitropic indices based on half-logistic time constants for four segmental phases in isovolumic left ventricular pressure-time curve in excised, cross-circulated canine heart.

    PubMed

    Mizuno, Ju; Mohri, Satoshi; Yokoyama, Takeshi; Otsuji, Mikiya; Arita, Hideko; Hanaoka, Kazuo

    2017-02-01

    Varying temperature affects cardiac systolic and diastolic function and the left ventricular (LV) pressure-time curve (PTC) waveform that includes information about LV inotropism and lusitropism. Our proposed half-logistic (h-L) time constants obtained by fitting using h-L functions for four segmental phases (Phases I-IV) in the isovolumic LV PTC are more useful indices for estimating LV inotropism and lusitropism during contraction and relaxation periods than the mono-exponential (m-E) time constants at normal temperature. In this study, we investigated whether the superiority of the goodness of h-L fits remained even at hypothermia and hyperthermia. Phases I-IV in the isovolumic LV PTCs in eight excised, cross-circulated canine hearts at 33, 36, and 38 °C were analyzed using h-L and m-E functions and the least-squares method. The h-L and m-E time constants for Phases I-IV significantly shortened with increasing temperature. Curve fitting using h-L functions was significantly better than that using m-E functions for Phases I-IV at all temperatures. Therefore, the superiority of the goodness of h-L fit vs. m-E fit remained at all temperatures. As LV inotropic and lusitropic indices, temperature-dependent h-L time constants could be more useful than m-E time constants for Phases I-IV.

  11. ACCELERATORS: Preliminary application of turn-by-turn data analysis to the SSRF storage ring

    NASA Astrophysics Data System (ADS)

    Chen, Jian-Hui; Zhao, Zhen-Tang

    2009-07-01

    There is growing interest in utilizing the beam position monitor turn-by-turn (TBT) data to debug accelerators. TBT data can be used to determine the linear optics, coupled optics and nonlinear behaviors of the storage ring lattice. This is not only a useful complement to other methods of determining the linear optics such as LOCO, but also provides a possibility to uncover more hidden phenomena. In this paper, a preliminary application of a β function measurement to the SSRF storage ring is presented.

  12. Actigraphic investigations on the activity-rest behavior of right- and left-handed students.

    PubMed

    Lehnkering, Hanna; Strauss, Andreas; Wegner, Brigitte; Siegmund, Renate

    2006-01-01

    The aim of this study was to explore differences between left-and right-handed subjects in sleep duration. Sleep and activity patterns were continuously registered for 12 days using actometers on 20 left-handed and 20 right-handed medical students in Berlin. Handedness was determined by a modified version of the Edinburgh handedness inventory. Each participant wore one actometer on each wrist. Actiwatch Sleep Analysis Software (CNT, UK) was used to evaluate the data, and statistical calculations were performed with a non-parametric variance analysis. A significant difference in mean sleep duration between left-handers (7.9 h) and right-handers (7.3 h) was determined (p=0.025 for measurement made on the dominant hand and p=0.013 for ones made on the non-dominant hand). In contrast, the maximal phase of daily activity (acrophase) did not show any difference between the two groups. The difference in sleep duration might be caused by either the greater effort required for left-handers to cope in a right-handed world or by structural brain differences.

  13. L-shaped right-to-left crossed-fused renal ectopia with left dysplastic ureter.

    PubMed

    Song, Wei; Yang, Jinrui; Zhu, Liang; Liu, Longfei

    2012-01-01

    Crossed-fused renal ectopia is a relatively rare congenital malformation. Herein, we report a case of L-shaped right- to-left crossed-fused renal ectopia with a left dysplastic ureter in a 5-year-old girl. She underwent a left nephrectomy and the postoperative course was uneventful. Copyright © 2011 S. Karger AG, Basel.

  14. Primordial spectra from sudden turning trajectory

    NASA Astrophysics Data System (ADS)

    Noumi, Toshifumi; Yamaguchi, Masahide

    2013-12-01

    Effects of heavy fields on primordial spectra of curvature perturbations are discussed in inflationary models with a sudden turning trajectory. When heavy fields are excited after the sudden turn and oscillate around the bottom of the potential, the following two effects are generically induced: deformation of the inflationary background spacetime and conversion interactions between adiabatic and isocurvature perturbations, both of which can affect the primordial density perturbations. In this paper, we calculate primordial spectra in inflationary models with sudden turning potentials taking into account both of the two effects appropriately. We find that there are some non-trivial correlations between the two effects in the power spectrum and, as a consequence, the primordial scalar power spectrum has a peak around the scale exiting the horizon at the turn. Though both effects can induce parametric resonance amplifications, they are shown to be canceled out for the case with the canonical kinetic terms. The peak feature and the scale dependence of bispectra are also discussed.

  15. Trunk-pelvis coordination during turning: A cross sectional study of young adults with and without a history of low back pain.

    PubMed

    Smith, Jo Armour; Kulig, Kornelia

    2016-07-01

    During steady-state locomotion, symptomatic individuals with low back pain demonstrate reduced ability to modulate coordination between the trunk and the pelvis in the axial plane. It is unclear if this is also true during functional locomotor perturbations such as changing direction, or if this change in coordination adaptability persists between symptomatic episodes. The purpose of this study was to compare trunk-pelvis coordination during walking turns in healthy individuals and asymptomatic individuals with a history of low back pain. Participants performed multiple ipsilateral turns. Axial plane inter-segmental coordination and stride-to-stride coordination variability were quantified using the vector coding technique. Frequency of coordination mode and amplitude of coordination variability was compared between groups using Wilcoxon signed-rank tests and paired t-tests respectively. During stance phase of the turn, there was no significant difference in either inter-segmental coordination or coordination variability between groups. Inter-segmental coordination between the trunk and the pelvis was predominantly inphase during this part of the turn. During swing phase, patterns of coordination were more diversified, and individuals with a history of low back pain had significantly greater trunk phase coordination than healthy controls. Coordination variability was the same in both groups. Changes in trunk-pelvis coordination are evident between symptomatic episodes in individuals with a history of low back pain. However, previously demonstrated decreases in coordination variability were not found between symptomatic episodes in individuals with recurrent low back pain and therefore may represent a response to concurrent pain rather than a persistent change in motor control. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Which Cheek did the Resurrected Jesus Turn?

    PubMed

    Acosta, Lealani Mae Y; Williamson, John B; Heilman, Kenneth M

    2015-06-01

    Secular portraits are likely to show more of the left than right side of the face (hemiface). Prior research has shown that emotions are more strongly expressed by the left hemiface. In addition, the valence theory of emotion proposes that the right hemisphere is dominant for mediating negative emotions, and the left hemisphere for positive emotions. Since religious art depicting a scene such as the Resurrection of Jesus is more likely to be associated with positive emotions, we postulated that there would be a significant smaller percentage number of artistic works of the Resurrection that reveal the left side of the face of Jesus than in those art works portraying the Crucifixion. Thus, we analyzed artistic portrayals of the Resurrection of Jesus and compared them to the artistic scenes of the Crucifixion. This analysis revealed that the left side of the face of Jesus is less commonly depicted in portraits of the Resurrection than the Crucifixion. In addition, both the right hemiface, and forward-facing faces were also more commonly portrayed in painting of the Resurrection than the Crucifixion. Whereas this right-left hemiface, Resurrection-Crucifixion dichotomy may be related to right-left hemispheric difference in the mediation of emotional valence other factors such as agency, action-intention, and biblical text may have influenced these differences.

  17. Identification of a key structural element for protein folding within beta-hairpin turns.

    PubMed

    Kim, Jaewon; Brych, Stephen R; Lee, Jihun; Logan, Timothy M; Blaber, Michael

    2003-05-09

    Specific residues in a polypeptide may be key contributors to the stability and foldability of the unique native structure. Identification and prediction of such residues is, therefore, an important area of investigation in solving the protein folding problem. Atypical main-chain conformations can help identify strains within a folded protein, and by inference, positions where unique amino acids may have a naturally high frequency of occurrence due to favorable contributions to stability and folding. Non-Gly residues located near the left-handed alpha-helical region (L-alpha) of the Ramachandran plot are a potential indicator of structural strain. Although many investigators have studied mutations at such positions, no consistent energetic or kinetic contributions to stability or folding have been elucidated. Here we report a study of the effects of Gly, Ala and Asn substitutions found within the L-alpha region at a characteristic position in defined beta-hairpin turns within human acidic fibroblast growth factor, and demonstrate consistent effects upon stability and folding kinetics. The thermodynamic and kinetic data are compared to available data for similar mutations in other proteins, with excellent agreement. The results have identified that Gly at the i+3 position within a subset of beta-hairpin turns is a key contributor towards increasing the rate of folding to the native state of the polypeptide while leaving the rate of unfolding largely unchanged.

  18. Sensor-based auto-focusing system using multi-scale feature extraction and phase correlation matching.

    PubMed

    Jang, Jinbeum; Yoo, Yoonjong; Kim, Jongheon; Paik, Joonki

    2015-03-10

    This paper presents a novel auto-focusing system based on a CMOS sensor containing pixels with different phases. Robust extraction of features in a severely defocused image is the fundamental problem of a phase-difference auto-focusing system. In order to solve this problem, a multi-resolution feature extraction algorithm is proposed. Given the extracted features, the proposed auto-focusing system can provide the ideal focusing position using phase correlation matching. The proposed auto-focusing (AF) algorithm consists of four steps: (i) acquisition of left and right images using AF points in the region-of-interest; (ii) feature extraction in the left image under low illumination and out-of-focus blur; (iii) the generation of two feature images using the phase difference between the left and right images; and (iv) estimation of the phase shifting vector using phase correlation matching. Since the proposed system accurately estimates the phase difference in the out-of-focus blurred image under low illumination, it can provide faster, more robust auto focusing than existing systems.

  19. Sensor-Based Auto-Focusing System Using Multi-Scale Feature Extraction and Phase Correlation Matching

    PubMed Central

    Jang, Jinbeum; Yoo, Yoonjong; Kim, Jongheon; Paik, Joonki

    2015-01-01

    This paper presents a novel auto-focusing system based on a CMOS sensor containing pixels with different phases. Robust extraction of features in a severely defocused image is the fundamental problem of a phase-difference auto-focusing system. In order to solve this problem, a multi-resolution feature extraction algorithm is proposed. Given the extracted features, the proposed auto-focusing system can provide the ideal focusing position using phase correlation matching. The proposed auto-focusing (AF) algorithm consists of four steps: (i) acquisition of left and right images using AF points in the region-of-interest; (ii) feature extraction in the left image under low illumination and out-of-focus blur; (iii) the generation of two feature images using the phase difference between the left and right images; and (iv) estimation of the phase shifting vector using phase correlation matching. Since the proposed system accurately estimates the phase difference in the out-of-focus blurred image under low illumination, it can provide faster, more robust auto focusing than existing systems. PMID:25763645

  20. Specific β-Turns Precede PPIIL Structures Binding to Allele-Specific HLA-DRβ1* PBRs in Fully-Protective Malaria Vaccine Components

    PubMed Central

    Bermudez, Adriana; Alba, Martha P.; Vanegas, Magnolia; Patarroyo, Manuel A.; Patarroyo, Manuel E.

    2018-01-01

    The 3D structural analysis of 62 peptides derived from highly pathogenic Plasmodium falciparum malaria parasite proteins involved in host cell invasion led to finding a striking association between particular β-turn types located in the N-terminal peripheral flanking residue region (preceding the polyproline II left-handed structures fitting into the HLA-DRβ* allele family) and modified immune protection-inducing protein structure induced long-lasting protective immunity. This is the first time association between two different secondary structures associated with a specific immunological function has been described: full, long-lasting protective immunity. PMID:29682500

  1. Specific β-Turns Precede PPIIL Structures Binding to Allele-Specific HLA-DRβ1* PBRs in Fully-Protective Malaria Vaccine Components.

    PubMed

    Bermudez, Adriana; Alba, Martha P; Vanegas, Magnolia; Patarroyo, Manuel A; Patarroyo, Manuel E

    2018-01-01

    The 3D structural analysis of 62 peptides derived from highly pathogenic Plasmodium falciparum malaria parasite proteins involved in host cell invasion led to finding a striking association between particular β-turn types located in the N-terminal peripheral flanking residue region (preceding the polyproline II left-handed structures fitting into the HLA-DRβ * allele family) and modified i mmune protection-inducing protein structure induced long-lasting protective immunity. This is the first time association between two different secondary structures associated with a specific immunological function has been described: full, long-lasting protective immunity.

  2. Specific β-turns precede PPIIL structures binding to allele-specific HLA-DRβ1* PBRs in fully-protective malaria vaccine components

    NASA Astrophysics Data System (ADS)

    Bermudez, Adriana; Alba, Martha P.; Vanegas, Magnolia; Patarroyo, Manuel A.; Patarroyo, Manuel E.

    2018-04-01

    The 3D structural analysis of 62 peptides derived from highly pathogenic Plasmodium falciparum malaria parasite proteins involved in host cell invasion led to finding a striking association between particular β-turn types located in the N-terminal peripheral flanking residue region (preceding the polyproline II left-handed structures fitting into the HLA-DRβ* allele family) and modified immune protection-inducing protein structure induced long-lasting protective immunity. This is the first time association between two different secondary structures associated with a specific immunological function has been described: full, long-lasting protective immunity.

  3. Revisiting the left-wing response to sociobiology: the case of Finland in a European context.

    PubMed

    Lepistö, Antti

    2015-01-01

    This article revisits the left-wing response to sociobiology in the 1970s and 1980s by examining the sociobiology debate in Finland in a larger European context. It argues that the Finnish academic left's response to sociobiology represents a "third way" alongside the purely negative, often Marxist denial of biology's relevance, which characterized the left's response to sociobiology in many European countries such as Hungary and Sweden, and alongside the disregard that sociobiology confronted in most parts of Eastern Europe, as well as in Germany. In the context of the last great political conflict of the Cold War in Europe, the controversy over the American "Euromissiles" (Pershing II and Tomahawk) in 1979-1983, the Finnish academic left challenged the allegedly fatalistic sociobiological aggression and war theories with an alternative biological language, turning the increasing enthusiasm over evolutionary ideas into a pacifist cause. Using leftist and pacifist forums to inform citizens and politicians of such biologically evolved human characteristics as mutual care and sociability, the Finnish critics of sociobiology wished to boost the public spirit, and to rationalize the pacifist ideal of the European-wide popular movement against nuclear weapons and militarism. As a result, the academic leftists in Finland revived the early twentieth-century tradition of "peace biology." A proper understanding of this development calls for an analysis that acknowledges Finland's special geopolitical and cultural position in the Cold War world between East and West.

  4. Influence of the Valsalva maneuver on cardiac hemodynamics and right to left shunt in patients with patent foramen ovale

    NASA Astrophysics Data System (ADS)

    Zhao, Enfa; Zhang, Yafei; Kang, Chunmiao; Niu, Hua; Zhao, Jing; Sun, Lei; Liu, Baomin

    2017-03-01

    The purpose of this study was to investigate the influence of the Valsalva maneuver (VM) on cardiac hemodynamics in patients with patent foramen ovale (PFO). Sixty-five patients who were highly suspected to have PFO were included. The changes in E, A, E/A ratio of mitral valve blood flow, E, A, E/A ratio of tricuspid valve blood flow, left ventricular end-diastolic volume, area and right atrial area during the resting state and the strain phase of the Valsalva maneuver were observed by transthoracic echocardiography (TTE). Statistical analyses were performed using SPSS Version18.0. Compared to the resting state, mitral valve diastolic velocity E and A peaks at the strain phase of the Valsalva maneuver significantly decreased (P < 0.05), left ventricular end diastolic volume(LVEDV) and area(LVEDA) decreased significantly (P < 0.05), while E/A ratio of mitral valve, tricuspid valve systolic velocity E and A peaks and E/A ratio remained unchanged (P > 0.05). PFO hemodynamic changes mainly occurred in the left ventricle when the Valsalva maneuver was performed. The Valsalva maneuver increased pressure in the chest, then pulmonary venous return was impeded, which resulted in left ventricular limited filling, and E and A peaks decreased. The pressure of the left ventricle and atrium was lower than that of the right side, which resulted in right-to-left shunt (RLS) through PFO.

  5. A Case of Left Renal Vein Ligation in a Patient with Solitary Left Kidney Undergoing Liver Transplantation to Control Splenorenal Shunt and Improve Portal Venous Flow.

    PubMed

    Martino, Rodrigo B; Júnior, Eserval Rocha; Manuel, Valdano; Rocha-Santos, Vinicius; D'Albuquerque, Luis Augusto C; Andraus, Wellington

    2017-10-11

    BACKGROUND Adequate portal venous flow is required for successful liver transplantation. Reduced venous flow and blood flow 'steal' by collateral vessels are a concern, and when there is a prominent splenorenal shunt present, ligation of the left renal vein has been recommended to improve portal venous blood flow. CASE REPORT A 51-year-old man who had undergone right nephrectomy in childhood required liver transplantation for liver cirrhosis and hepatocellular carcinoma due to hepatitis C virus (HCV) infection. The patient had no other comorbidity and no history of hepatorenal syndrome. At transplantation surgery, portal venous flow was poor and did not improve with ligation of shunt veins, but ligation of the left renal vein improved portal venous flow. On the first and fifth postoperative days, the patient was treated with basiliximab, a chimeric monoclonal antibody to the IL-2 receptor, and methylprednisolone. The calcineurin inhibitor, tacrolimus, was introduced on the fifth postoperative day. On the sixteenth postoperative day, renal color Doppler ultrasound showed normal left renal parenchyma; hepatic Doppler ultrasound showed good portal vein flow and preserved hepatic parenchyma in the liver transplant. CONCLUSIONS This case report has shown that in a patient with a single left kidney, left renal vein ligation is feasible and safe in a patient with no other risk factors for renal impairment following liver transplantation. Modification of postoperative immunosuppression to avoid calcineurin inhibitors in the very early postoperative phase may be important in promoting good recovery of renal function and to avoid the need for postoperative renal dialysis.

  6. Left-Deviating Prism Adaptation in Left Neglect Patient: Reflexions on a Negative Result

    PubMed Central

    Luauté, Jacques; Jacquin-Courtois, Sophie; O'Shea, Jacinta; Christophe, Laure; Rode, Gilles; Boisson, Dominique; Rossetti, Yves

    2012-01-01

    Adaptation to right-deviating prisms is a promising intervention for the rehabilitation of patients with left spatial neglect. In order to test the lateral specificity of prism adaptation on left neglect, the present study evaluated the effect of left-deviating prism on straight-ahead pointing movements and on several classical neuropsychological tests in a group of five right brain-damaged patients with left spatial neglect. A group of healthy subjects was also included for comparison purposes. After a single session of exposing simple manual pointing to left-deviating prisms, contrary to healthy controls, none of the patients showed a reliable change of the straight-ahead pointing movement in the dark. No significant modification of attentional paper-and-pencil tasks was either observed immediately or 2 hours after prism adaptation. These results suggest that the therapeutic effect of prism adaptation on left spatial neglect relies on a specific lateralized mechanism. Evidence for a directional effect for prism adaptation both in terms of the side of the visuomanual adaptation and therefore possibly in terms of the side of brain affected by the stimulation is discussed. PMID:23050168

  7. Frequency Bandwidth Optimization of Left-Handed Metamaterial

    NASA Technical Reports Server (NTRS)

    Chevalier, Christine T.; Wilson, Jeffrey D.

    2004-01-01

    Recently, left-handed metamaterials (LHM s) have been demonstrated with an effective negative index of refraction and with antiparallel group and phase velocities for microwave radiation over a narrow frequency bandwidth. In order to take advantage of these characteristics for practical applications, it will be beneficial to develop LHM s with increased frequency bandwidth response and lower losses. In this paper a commercial three-dimensional electromagnetic simulation code is used to explore the effects of geometry parameter variations on the frequency bandwidth of a LHM at microwave frequencies. Utilizing an optimizing routine in the code, a geometry was generated with a bandwidth more than twice as large as the original geometry.

  8. Left atrium function by 2D speckle tracking in aortic valve disease.

    PubMed

    Salas-Pacheco, Jose L; Ávila-Vanzzini, Nydia; Eugenia, Ruiz-Esparza M; Arias-Godínez, Jose A

    2016-12-01

    A paucity of data exists about left atrium (LA) function in aortic valve stenosis (AS) or regurgitation (AR). Two-dimensional speckle tracking echocardiography allows the noninvasive study of LA functional disturbances in aortic valve disease and their impact in the development of pulmonary hypertension (PH). Consecutive patients with moderate or severe AS or AR were included. Left ventricle (LV) and LA speckle tracking strain quantification was performed. We included 42 patients with AS and 30 with AR. Differences were not found in LA volumes and strain in AS or AR. The LA volumetric derangements parallel the decrease in LA longitudinal strain. Maximum LA volume, minimum LA volume, and indexed LA volume were higher in severe valvular disease (SVD) than in moderate [23 cc (P=.018, IC 95% : 4-41), 16 cc (P=.035, IC 95% : 2-31), and 14 cc (P=.022, IC 95% : 2-25), respectively], occurred in the same way with LA strain in the conduit (6.3%, P=.034, IC 95% : 1-12) and reservoir (7.1%, P=.04, IC 95% : 2-14) phases. In multivariable model, strain of reservoir phase was the variable mainly associated with PH; each decrease in one unit of strain of reservoir phase increased 6% the PH probability (OR: 1.06, P=.01). This study demonstrates that in patients with AS and AR, the LA has a similar behavior and that exist a close correlation between LA volumetric and functional parameters. The variable mainly associated with PH was LA strain of reservoir phase. © 2016, Wiley Periodicals, Inc.

  9. Characterization of cardiac quiescence from retrospective cardiac computed tomography using a correlation-based phase-to-phase deviation measure

    PubMed Central

    Wick, Carson A.; McClellan, James H.; Arepalli, Chesnal D.; Auffermann, William F.; Henry, Travis S.; Khosa, Faisal; Coy, Adam M.; Tridandapani, Srini

    2015-01-01

    Purpose: Accurate knowledge of cardiac quiescence is crucial to the performance of many cardiac imaging modalities, including computed tomography coronary angiography (CTCA). To accurately quantify quiescence, a method for detecting the quiescent periods of the heart from retrospective cardiac computed tomography (CT) using a correlation-based, phase-to-phase deviation measure was developed. Methods: Retrospective cardiac CT data were obtained from 20 patients (11 male, 9 female, 33–74 yr) and the left main, left anterior descending, left circumflex, right coronary artery (RCA), and interventricular septum (IVS) were segmented for each phase using a semiautomated technique. Cardiac motion of individual coronary vessels as well as the IVS was calculated using phase-to-phase deviation. As an easily identifiable feature, the IVS was analyzed to assess how well it predicts vessel quiescence. Finally, the diagnostic quality of the reconstructed volumes from the quiescent phases determined using the deviation measure from the vessels in aggregate and the IVS was compared to that from quiescent phases calculated by the CT scanner. Three board-certified radiologists, fellowship-trained in cardiothoracic imaging, graded the diagnostic quality of the reconstructions using a Likert response format: 1 = excellent, 2 = good, 3 = adequate, 4 = nondiagnostic. Results: Systolic and diastolic quiescent periods were identified for each subject from the vessel motion calculated using the phase-to-phase deviation measure. The motion of the IVS was found to be similar to the aggregate vessel (AGG) motion. The diagnostic quality of the coronary vessels for the quiescent phases calculated from the aggregate vessel (PAGG) and IVS (PIV S) deviation signal using the proposed methods was comparable to the quiescent phases calculated by the CT scanner (PCT). The one exception was the RCA, which improved for PAGG for 18 of the 20 subjects when compared to PCT (PCT = 2.48; PAGG = 2.07, p = 0

  10. Turning rice meiosis into mitosis

    PubMed Central

    Mieulet, Delphine; Jolivet, Sylvie; Rivard, Maud; Cromer, Laurence; Vernet, Aurore; Mayonove, Pauline; Pereira, Lucie; Droc, Gaëtan; Courtois, Brigitte; Guiderdoni, Emmanuel; Mercier, Raphael

    2016-01-01

    Introduction of clonal reproduction through seeds (apomixis) in crops has the potential to revolutionize agriculture by allowing self-propagation of any elite variety, in particular F1 hybrids. In the sexual model plant Arabidopsis thaliana synthetic clonal reproduction through seeds can be artificially implemented by (i) combining three mutations to turn meiosis into mitosis (MiMe) and (ii) crossing the obtained clonal gametes with a line expressing modified CENH3 and whose genome is eliminated in the zygote. Here we show that additional combinations of mutations can turn Arabidopsis meiosis into mitosis and that a combination of three mutations in rice (Oryza sativa) efficiently turns meiosis into mitosis, leading to the production of male and female clonal diploid gametes in this major crop. Successful implementation of the MiMe technology in the phylogenetically distant eudicot Arabidopsis and monocot rice opens doors for its application to any flowering plant and paves the way for introducing apomixis in crop species. PMID:27767093

  11. Magnetic substorms and northward IMF turning

    NASA Astrophysics Data System (ADS)

    Troshichev, Oleg; Podorozhkina, Nataly

    To determine the relation of the northward IMF turnings to substorm sudden onsets, we separated all events with sharp northward IMF turnings observed in years of solar maximum (1999-2002) and solar minimum (2007-2008). The events (N=261) have been classified in 5 groups in accordance with average magnetic activity in auroral zone (low, moderate or high levels of AL index) at unchanged or slightly changed PC index and with dynamics of PC (steady distinct growth or distinct decline) at arbitrary values of AL index. Statistical analysis of relationships between the IMF turning and changes of PC and AL indices has been fulfilled separately for each of 5 classes. Results of the analysis showed that, irrespective of geophysical conditions and solar activity epoch, the magnetic activity in the polar caps and in the auroral zone demonstrate no response to the sudden northward IMF turning, if the moment of northward turning is taken as a key date. Sharp increases of magnetic disturbance in the auroral zone are observed only under conditions of the growing PC index and statistically they are related to moment of the PC index exceeding the threshold level (~1.5 mV/m), not to northward turnings timed, as a rule, after the moment of sudden onset. Magnetic disturbances observed in these cases in the auroral zone (magnetic substorms) are guided by behavior of the PC index, like to ordinary magnetic substorms or substorms developed under conditions of the prolonged northward IMF impact on the magnetosphere. The evident inconsistency between the sharp IMF changes measured outside of the magnetosphere and behavior of the ground-based PC index, the latter determining the substorm development, provides an additional argument in favor of the PC index as a ground-based proxy of the solar wind energy that entered into magnetosphere.

  12. Hypoplastic left heart syndrome (image)

    MedlinePlus

    Hypoplastic left heart syndrome is a congenital heart condition that occurs during the development of the heart in the ... womb. During the heart's development, parts of the left side of the heart (mitral valve, left ventricle ...

  13. 33 CFR 164.42 - Rate of turn indicator.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Rate of turn indicator. 164.42...) PORTS AND WATERWAYS SAFETY NAVIGATION SAFETY REGULATIONS § 164.42 Rate of turn indicator. Each vessel of... turn indicator. [CGD 83-004, 49 FR 43468, Oct. 29, 1984] ...

  14. 33 CFR 164.42 - Rate of turn indicator.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Rate of turn indicator. 164.42...) PORTS AND WATERWAYS SAFETY NAVIGATION SAFETY REGULATIONS § 164.42 Rate of turn indicator. Each vessel of... turn indicator. [CGD 83-004, 49 FR 43468, Oct. 29, 1984] ...

  15. [Study of beta-turns in globular proteins].

    PubMed

    Amirova, S R; Milchevskiĭ, Iu V; Filatov, I V; Esipova, N G; Tumanian, V G

    2005-01-01

    The formation of beta-turns in globular proteins has been studied by the method of molecular mechanics. Statistical method of discriminant analysis was applied to calculate energy components and sequences of oligopeptide segments, and after this prediction of I type beta-turns has been drawn. The accuracy of true positive prediction is 65%. Components of conformational energy considerably affecting beta-turn formation were delineated. There are torsional energy, energy of hydrogen bonds, and van der Waals energy.

  16. Resolution enhancement in 13C and 15N magic-angle turning experiments with TPPM decoupling.

    PubMed

    McGeorge, G; Alderman, D W; Grant, D M

    1999-03-01

    Many solid-state spectra have been shown to have problems related to the poor proton decoupling of carbon nuclei in methylene groups under conditions of slow magic-angle turning. Two-pulse phase-modulation (TPPM) decoupling during the 2D PHORMAT chemical shift separation experiment is shown to be more effective in comparison to that obtainable at much higher spin rates using conventional CW decoupling. TPPM decoupling can also alleviate similar inadequacies when observing the 15N nucleus, particularly with NH2 groups. This is demonstrated in the 15N resonances of fully labeled l-arginine hydrochloride, where a line narrowing of about a factor of two was observed at moderate rotation rates. This significant advantage was also obtained at turning frequencies as low as 500 Hz. Copyright 1999 Academic Press.

  17. Electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure.

    PubMed

    Fan, Ling; Chen, Li-Feng; Fan, Jing

    2017-12-01

    To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure. Guinea pigs model of iron deficiency anemia complicated with chronic heart failure in 10 guinea pigs of the experimental group was made by feeding a low iron diet, pure water and subcutaneous injection of isoproterenol. The control group consisting of 11 guinea pigs was given normal food, normal water and injected with normal saline. The left ventricular outflow tract model specimen was also prepared. The standard microelectrode technique was used to observe electrophysiological changes of autonomic cells in the outflow tract of left ventricular heart failure complicated with iron deficiency anemia in guinea pig model. The indicators of observation were maximal diastolic potential, action potential amplitude, 0 phase maximal depolarization velocity, 4 phase automatic depolarization velocity, repolarization 50% and 90%, and spontaneous discharge frequency. Compared with the control group, 4 phase automatic depolarization velocity, spontaneous discharge frequency and 0 phase maximal depolarization velocity decreased significantly (P < 0.01) and action potential amplitude reduced (P < 0.01) in model group. Moreover, repolarization 50% and 90% increased (P < 0.01). There are electrophysiological abnormalities of the left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with heart failure. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

  18. Exploring the Nuclear Phase Diagram with Beam Energy Scans

    NASA Astrophysics Data System (ADS)

    Horvat, Stephen

    2017-04-01

    The nuclear phase diagram is mapped using beam energy scans of relativistic heavy-ion collisions. This mapping is possible because different collision energies develop along different trajectories through the phase diagram. High energy collisions will evolve though a crossover phase transition according to lattice QCD, but lower collision energies may traverse a first order phase transition. There are hints for this first order phase transition and its critical endpoint, but further measurements and theoretical guidance is needed. In addition to mapping the phase transition, beam energy scans allow us to see if we can turn off the signatures of deconfinement. If an observable is a real signature for the formation of the deconfined state called quark-gluon plasma, then it should turn off at sufficiently low collision energies. In this summary talk I will show the current state of the field using beam energy scan results from RHIC and SPS, I will show where precise theoretical guidance is needed for understanding recent measurements, and I will motivate the need for more data and new measurements from FAIR, NICA, RHIC, and the SPS.

  19. TMS over the Left Angular Gyrus Impairs the Ability to Discriminate Left from Right

    ERIC Educational Resources Information Center

    Hirnstein, Marco; Bayer, Ulrike; Ellison, Amanda; Hausmann, Markus

    2011-01-01

    The underlying cognitive and neural mechanisms of the ability to discriminate left from right are hardly explored. Clinical studies from patients with impairments of left-right discrimination (LRD) and neuroimaging data suggest that the left angular gyrus is particularly involved in LRD. Moreover, it is argued that the often reported sex…

  20. Three-Dimensional Lower Extremity Joint Loading in a Carved Ski and Snowboard Turn: A Pilot Study

    PubMed Central

    Müller, Erich

    2014-01-01

    A large number of injuries to the lower extremity occur in skiing and snowboarding. Due to the difficulty of collecting 3D kinematic and kinetic data with high accuracy, a possible relationship between injury statistic and joint loading has not been studied. Therefore, the purpose of the current study was to compare ankle and knee joint loading at the steering leg between carved ski and snowboard turns. Kinetic data were collected using mobile force plates mounted under the toe and heel part of the binding on skies or snowboard (KISTLER). Kinematic data were collected with five synchronized, panning, tilting, and zooming cameras. An extended version of the Yeadon model was applied to calculate inertial properties of the segments. Ankle and knee joint forces and moments were calculated using inverse dynamic analysis. Results showed higher forces along the longitudinal axis in skiing and similar forces for skiing and snowboarding in anterior-posterior and mediolateral direction. Joint moments were consistently greater during a snowboard turn, but more fluctuations were observed in skiing. Hence, when comparing joint loading between carved ski and snowboard turns, one should differentiate between forces and moments, including the direction of forces and moments and the turn phase. PMID:25317202

  1. Phase Transition and Texture Evolution in the Ni-Mn-Ga Ferromagnetic Shape-Memory Alloys Studied by a Neutron Diffraction Technique

    NASA Astrophysics Data System (ADS)

    Nie, Z. H.; Wang, Y. D.; Wang, G. Y.; Richardson, J. W.; Wang, G.; Liu, Y. D.; Liaw, P. K.; Zuo, L.

    2008-12-01

    The phase transition and influence of the applied stress on the texture evolution in the as-cast Ni-Mn-Ga ferromagnetic shape-memory alloys were studied by the time-of-flight (TOF) neutron diffraction technique. The neutron diffraction experiments were performed on the General Purpose Powder Diffractometer (Argonne National Laboratory). Inverse pole figures were determined from the neutron data for characterizing the orientation distributions and variant selections of polycrystalline Ni-Mn-Ga alloys subjected to different uniaxial compression deformations. Texture analyses reveal that the initial texture for the parent phase in the as-cast specimen was composed of {left\\{ {{text{001}}} right\\}}{left< {{text{100}}} rightrangle } , {left\\{ {{text{001}}} right\\}}{left< {{text{110}}} rightrangle } , {left\\{ {{text{011}}} right\\}}{left< {{text{100}}} rightrangle } , and {left\\{ {{text{011}}} right\\}}{left< {{text{110}}} rightrangle } , which was weakened after the compression deformation. Moreover, a strong preferred selection of martensitic-twin variants ( {left\\{ {{text{110}}} right\\}}{left< {{text{001}}} rightrangle } and {left\\{ {{text{100}}} right\\}}{left< {{text{001}}} rightrangle } ) was observed in the transformed martensite after a compression stress applied on the parent phase along the cyclindrical axis of the specimens. The preferred selection of variants can be well explained by considering the grain/variant-orientation-dependent Bain-distortion energy.

  2. Page turning solutions for musicians: a survey.

    PubMed

    Wolberg, George; Schipper, Irene

    2012-01-01

    Musicians have long been hampered by the challenge in turning sheet music while their hands are occupied playing an instrument. The sight of a human page turner assisting a pianist during a performance, for instance, is not uncommon. This need for a page turning solution is no less acute during practice sessions, which account for the vast majority of playing time. Despite widespread appreciation of the problem, there have been virtually no robust and affordable products to assist the musician. Recent progress in assistive technology and electronic reading devices offers promising solutions to this long-standing problem. The objective of this paper is to survey the technology landscape and assess the benefits and drawbacks of page turning solutions for musicians. A full range of mechanical and digital page turning products are reviewed.

  3. Experimental Hydrodynamics of Turning Maneuvers in Koi Carps

    NASA Astrophysics Data System (ADS)

    Wu, G. H.; Yang, Y.; Zeng, L. J.

    Experimental hydrodynamics of two types of turning maneuvers in koi carps (cyprinus carpio koi) are studied. The flow patterns generated by koi carps during turning are quantified by using digital particle image velocimetry. Based on the velocity fields measured, the momentums in the wake and the impulsive moments exerted on the carps are estimated. On the other hand, turning rates and radii, and moments of inertia of the carps including added mass during turning are obtained by processing the images recorded. Comparisons of the impulsive moments and moments of inertia show good agreements.

  4. STS-92 Mission Specialist Wakata takes his turn driving the M-113

    NASA Technical Reports Server (NTRS)

    2000-01-01

    With Capt. George Hoggard, trainer with the KSC Fire Department, riding on top, Mission Specialist Koichi Wakata of Japan practices driving the M-113, part of emergency egress training during Terminal Countdown Demonstration Test (TCDT) activities. Riding in the back (on the left) are other crew members, waiting their turn to drive. The tracked vehicle could be used by the crew in the event of an emergency at the pad during which the crew must make a quick exit from the area. The TCDT also provides simulated countdown exercises and opportunities to inspect the mission payloads in the orbiter's payload bay. STS-92 is scheduled to launch Oct. 5 at 9:30 p.m. EDT on the fifth flight to the International Space Station. It will carry two elements of the Space Station, the Integrated Truss Structure Z1 and the third Pressurized Mating Adapter. The mission is also the 100th flight in the Shuttle program.

  5. STS-92 Mission Specialist Wakata completes his turn driving the M-113

    NASA Technical Reports Server (NTRS)

    2000-01-01

    STS-92 Mission Specialist Koichi Wakata of Japan signals a successful driving lesson on the M-113 he is in. Capt. George Hoggard, trainer with the KSC Fire Department, sits on top. Behind Wakata are Commander Brian Duffy (left) and Leroy Chiao (right), waiting their turns. The practice drive is part of emergency egress training during Terminal Countdown Demonstration Test (TCDT) activities. The tracked vehicle could be used by the crew in the event of an emergency at the pad during which the crew must make a quick exit from the area. The TCDT also provides simulated countdown exercises and opportunities to inspect the mission payloads in the orbiter's payload bay. STS-92 is scheduled to launch Oct. 5 at 9:30 p.m. EDT on the fifth flight to the International Space Station. It will carry two elements of the Space Station, the Integrated Truss Structure Z1 and the third Pressurized Mating Adapter. The mission is also the 100th flight in the Shuttle program.

  6. Multiple left anterior descending coronary artery to left ventricular fistula - A case series and literature review.

    PubMed

    Iyer, Praneet; Yelisetti, Rishitha

    2017-10-01

    Coronary artery fistulas (CAFs) are found in 0.3-0.8% of patients who undergo coronary angiography. CAFs are defined as single or multiple, small or large direct communications that arise from one or more coronary arteries and enter into one of the four cardiac chambers or major vessels. We present two cases of multiple coronary artery fistulas arising from diagonal and left anterior descending (LAD) branches of left coronary artery draining into the left ventricle. In both the cases, No intervention was performed. Of the congenital fistulas, two major groups are identified: solitary CAFs or coronary artery-left ventricular multiple micro-fistulas (CALVMMFs). Noninvasive techniques such as transthoracic echocardiography, transesophageal echocardiography and magnetic resonance imaging are becoming increasingly popular for diagnosis and follow-up of CAFs. Despite the advent of these newer non-invasive modalities, coronary angiography remains the gold standard for diagnosis. Treatment of CAFs is indicated when the patients are symptomatic with left ventricular volume overload, myocardial ischemia, left ventricular dysfunction or in the presence of a large or increasing left-to-right shunt. If the fistula is small and hemodynamically insignificant, it can be managed with conservative management. Multiple left anterior descending to left ventricle (LV) fistulas are extremely rare and, as per our literature review, we noted only a few case reports of coronary artery fistulas between branches of LAD and left ventricle.

  7. Impact of left atrial volume reduction concomitant with atrial fibrillation surgery on left atrial geometry and mechanical function.

    PubMed

    Marui, Akira; Saji, Yoshiaki; Nishina, Takeshi; Tadamura, Eiji; Kanao, Shotaro; Shimamoto, Takeshi; Sasahashi, Nozomu; Ikeda, Tadashi; Komeda, Masashi

    2008-06-01

    Left atrial geometry and mechanical functions exert a profound effect on left ventricular filling and overall cardiovascular performance. We sought to investigate the perioperative factors that influence left atrial geometry and mechanical functions after the Maze procedure in patients with refractory atrial fibrillation and left atrial enlargement. Seventy-four patients with atrial fibrillation and left atrial enlargement (diameter > or = 60 mm) underwent the Maze procedure in association with mitral valve surgery. The maximum left atrial volume and left atrial mechanical functions (booster pump, reservoir, and conduit function [%]) were calculated from the left atrial volume-cardiac cycle curves obtained by magnetic resonance imaging. A stepwise multiple regression analysis was performed to determine the independent variables that influenced the postoperative left atrial geometry and function. The multivariate analysis showed that left atrial reduction surgery concomitant with the Maze procedure and the postoperative maintenance of sinus rhythm were predominant independent variables for postoperative left atrial geometry and mechanical functions. Among the 58 patients who recovered sinus rhythm, the postoperative left atrial geometry and function were compared between patients with (VR group) and without (control group) left atrial volume reduction. At a mean follow-up period of 13.8 months, sinus rhythm recovery rate was better (85% vs 68%, P < .05) in the VR group and maximum left atrial volume was less (116 +/- 25 mL vs 287 +/- 73 mL, P < .001) than in the control group. The maximum left atrial volume reduced with time only in the VR group (reverse remodeling). Postoperative booster pump and reservoir function in the VR group were better than in the control group (25% +/- 6% vs 11% +/- 4% and 34% +/- 7% vs 16% +/- 4%, respectively, P < .001), whereas the conduit function in the VR group was lower than in the control group, indicating that the improvement of

  8. Biased optimal guidance for a bank-to-turn missile

    NASA Astrophysics Data System (ADS)

    Stallard, D. V.

    A practical terminal-phase guidance law for controlling the pitch acceleration and roll rate of a bank-to-turn missile with zero autopilot lags was derived and tested, so as to minimize squared miss distance without requiring overly large commands. An acceleration bias is introduced to prevent excessive roll commands due to noise. The Separation Theorem is invoked and the guidance (control) law is derived by applying optimal control theory, linearizing the nonlinear plant equation around the present missile orientation, and obtaining a closed-form solution. The optimal pitch-acceleration and roll-rate commands are respectively proportional to two components of the projected, constant-bias, miss distance, with a resemblance to earlier derivations and proportional navigation. Simulaiation results and other related work confirm the suitability of the guidance law.

  9. A new inverter topology using GTO commutation. [Gate Turn Off thyristor

    NASA Technical Reports Server (NTRS)

    Rippel, W. E.

    1983-01-01

    A new N-phase, forced commutated bridge inverter topology has been developed wherein a single Gate Turn Off Thyristor (GTO) is used to commutate each of 2N main Thyristors (SCRs). Since, for most applications, the primary loss mechanism is the SCR forward drop, very high efficiencies are possible. Compared with conventional pure SCR and pure GTO inverters, cost per kW is lower - in the former case due to the large cost differential between GTOs and SCRs. Other advantages of the new inverter include high power density, low switching losses and stresses, modulation flexibility and amenability to high voltage and high frequency operation.

  10. Estimating intersection turning movements.

    DOT National Transportation Integrated Search

    1999-05-01

    Turning movement (TM) counts are used for a variety of intersection analyses, including traffic operations analyses, : intersection design, and transportation planning applications. For many planning and design applications, especially in the case of...

  11. A servo-controlled canine model of stable severe ischemic left ventricular failure.

    PubMed

    Wagner, Richard L; Hood, William B; Howland, Peter A

    2009-12-01

    Reversible left ventricular failure was produced in conscious dogs by compromise of the coronary circulation. In animals with prior left anterior descending coronary artery occlusion, mean left atrial pressure (LAP) was incorporated into an automatic feedback control system used to inflate a balloon cuff on the circumflex (Cfx) coronary artery. The system could produce stable increases in LAP to 15-20 mm Hg. The dominating system transfer function was the ratio of LAP to balloon volume (BV), which was characterized by a fixed delay (5 s), with LAP/BV = (8e(-jomegatau ))/(0.02 + jomega). The system was stabilized by a phase lead network to reduce oscillations of LAP. A total of seven experiments were conducted in three dogs, and testing of inotropic agents was possible in three experiments under stable conditions with the pump off after an hour or more of operation. Problems encountered were 0.003-0.008 Hz oscillations in LAP in three experiments, which could usually be controlled by reducing the system gain. Late stage ventricular fibrillation occurred in all three animals, but defibrillation was easily accomplished after deflating the Cfx balloon. This system produces reversible left ventricular failure solely due to ischemia, thus closely simulating clinical heart failure due to coronary insufficiency.

  12. Left atrial extension of hepatoblastoma via left superior pulmonary vein.

    PubMed

    Atalay, Atakan; Gocen, Uğur; Yaliniz, Hafize

    2014-10-01

    Hepatoblastoma is the most common malignant liver tumour in early childhood. The metastatic extension of hepatoblastoma into the left atrium via the pulmonary vein is rare. Reported lesions almost always involve a right-sided approach. Here we report the case of a 3-year-old girl with a recurrent hepatoblastoma at multiple sites, including the left atrium, brain, and lung. The patient was treated surgically for the prevention of further embolic complications and cardiac failure.

  13. Dyscalculia, dysgraphia, and left-right confusion from a left posterior peri-insular infarct.

    PubMed

    Bhattacharyya, S; Cai, X; Klein, J P

    2014-01-01

    The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation.

  14. Dyscalculia, Dysgraphia, and Left-Right Confusion from a Left Posterior Peri-Insular Infarct

    PubMed Central

    Bhattacharyya, S.; Cai, X.; Klein, J. P.

    2014-01-01

    The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation. PMID:24817791

  15. Apraxia in left-handers.

    PubMed

    Goldenberg, Georg

    2013-08-01

    In typical right-handed patients both apraxia and aphasia are caused by damage to the left hemisphere, which also controls the dominant right hand. In left-handed subjects the lateralities of language and of control of the dominant hand can dissociate. This permits disentangling the association of apraxia with aphasia from that with handedness. Pantomime of tool use, actual tool use and imitation of meaningless hand and finger postures were examined in 50 consecutive left-handed subjects with unilateral hemisphere lesions. There were three aphasic patients with pervasive apraxia caused by left-sided lesions. As the dominant hand is controlled by the right hemisphere, they constitute dissociations of apraxia from handedness. Conversely there were also three patients with pervasive apraxia caused by right brain lesions without aphasia. They constitute dissociations of apraxia from aphasia. Across the whole group of patients dissociations from handedness and from aphasia were observed for all manifestations of apraxia, but their frequency depended on the type of apraxia. Defective pantomime and defective tool use occurred rarely without aphasia, whereas defective imitation of hand, but not finger, postures was more frequent after right than left brain damage. The higher incidence of defective imitation of hand postures in right brain damage was mainly due to patients who had also hemi-neglect. This interaction alerts to the possibility that the association of right hemisphere damage with apraxia has to do with spatial aptitudes of the right hemisphere rather than with its control of the dominant left hand. Comparison with data from right-handed patients showed no differences between the severity of apraxia for imitation of hand or finger postures, but impairment on pantomime of tool use was milder in apraxic left-handers than in apraxic right-handers. This alleviation of the severity of apraxia corresponded with a similar alleviation of the severity of aphasia as

  16. Connecting Dirac and Majorana neutrino mass matrices in the minimal left-right symmetric model.

    PubMed

    Nemevšek, Miha; Senjanović, Goran; Tello, Vladimir

    2013-04-12

    Probing the origin of neutrino mass by disentangling the seesaw mechanism is one of the central issues of particle physics. We address it in the minimal left-right symmetric model and show how the knowledge of light and heavy neutrino masses and mixings suffices to determine their Dirac Yukawa couplings. This in turn allows one to make predictions for a number of high and low energy phenomena, such as decays of heavy neutrinos, neutrinoless double beta decay, electric dipole moments of charged leptons, and neutrino transition moments. We also discuss a way of reconstructing the neutrino Dirac Yukawa couplings at colliders such as the LHC.

  17. Silicon Carbide Emitter Turn-Off Thyristor

    DOE PAGES

    Wang, Jun; Wang, Gangyao; Li, Jun; ...

    2008-01-01

    A novel MOS-conmore » trolled SiC thyristor device, the SiC emitter turn-off thyristor (ETO) is a promising technology for future high-voltage switching applications because it integrates the excellent current conduction capability of a SiC thyristor with a simple MOS-control interface. Through unity-gain turn-off, the SiC ETO also achieves excellent Safe Operation Area (SOA) and faster switching speeds than silicon ETOs. The world's first 4.5-kV SiC ETO prototype shows a forward voltage drop of 4.26 V at 26.5  A / cm 2 current density at room and elevated temperatures. Tested in an inductive circuit with a 2.5 kV DC link voltage and a 9.56-A load current, the SiC ETO shows a fast turn-off time of 1.63 microseconds and a low 9.88 mJ turn-off energy. The low switching loss indicates that the SiC ETO could operate at about 4 kHz if 100  W / cm 2 conduction and the 100  W / cm 2 turn-off losses can be removed by the thermal management system. This frequency capability is about 4 times higher than 4.5-kV-class silicon power devices. The preliminary demonstration shows that the SiC ETO is a promising candidate for high-frequency, high-voltage power conversion applications, and additional developments to optimize the device for higher voltage (>5 kV) and higher frequency (10 kHz) are needed.« less

  18. A large left ventricular thrombus.

    PubMed

    Patanè, Salvatore; Marte, Filippo

    2009-06-26

    The discovery of a left ventricular mass obliges the clinician to perform a differential diagnosis including tumour or lipoma versus thrombus and its assessment presents important clinical implications. Dilated cardiomyopathy has been associated with left ventricular thrombosis which leads to substantial morbidity and mortality as a site for peripheral emboli. There are some studies on patients with dilated cardiomyopathy showing altered hemostasis and platelet behavior despite sinus rhythm. An increased incidence of thromboembolism is also well recognized in patients with left ventricular systolic dysfunction complicating history of myocardial infarction. Clinical dilemmas in treating left ventricular thrombus have been described too. We present a case of a large mobile left ventricular thrombus in a 71-year-old Italian man with dilated cardiomyopathy and history of myocardial infarction.

  19. How many hydrogen-bonded α-turns are possible?

    PubMed

    Schreiber, Anette; Schramm, Peter; Hofmann, Hans-Jörg

    2011-06-01

    The formation of α-turns is a possibility to reverse the direction of peptide sequences via five amino acids. In this paper, a systematic conformational analysis was performed to find the possible isolated α-turns with a hydrogen bond between the first and fifth amino acid employing the methods of ab initio MO theory in vacuum (HF/6-31G*, B3LYP/6-311 + G*) and in solution (CPCM/HF/6-31G*). Only few α-turn structures with glycine and alanine backbones fulfill the geometry criteria for the i←(i + 4) hydrogen bond satisfactorily. The most stable representatives agree with structures found in the Protein Data Bank. There is a general tendency to form additional hydrogen bonds for smaller pseudocycles corresponding to β- and γ-turns with better hydrogen bond geometries. Sometimes, this competition weakens or even destroys the i←(i + 4) hydrogen bond leading to very stable double β-turn structures. This is also the reason why an "ideal" α-turn with three central amino acids having the perfect backbone angle values of an α-helix could not be localized. There are numerous hints for stable α-turns with a distance between the C(α)-atoms of the first and fifth amino acid smaller than 6-7 Å, but without an i←(i + 4) hydrogen bond.

  20. Recent developments in turning hardened steels - A review

    NASA Astrophysics Data System (ADS)

    Sivaraman, V.; Prakash, S.

    2017-05-01

    Hard materials ranging from HRC 45 - 68 such as hardened AISI H13, AISI 4340, AISI 52100, D2 STL, D3 STEEL Steel etc., need super hard tool materials to machine. Turning of these hard materials is termed as hard turning. Hard turning makes possible direct machining of the hard materials and also eliminates the lubricant requirement and thus favoring dry machining. Hard turning is a finish turning process and hence conventional grinding is not required. Development of the new advanced super hard tool materials such as ceramic inserts, Cubic Boron Nitride, Polycrystalline Cubic Boron Nitride etc. enabled the turning of these materials. PVD and CVD methods of coating have made easier the production of single and multi layered coated tool inserts. Coatings of TiN, TiAlN, TiC, Al2O3, AlCrN over cemented carbide inserts has lead to the machining of difficult to machine materials. Advancement in the process of hard machining paved way for better surface finish, long tool life, reduced tool wear, cutting force and cutting temperatures. Micro and Nano coated carbide inserts, nanocomposite coated PCBN inserts, micro and nano CBN coated carbide inserts and similar developments have made machining of hardened steels much easier and economical. In this paper, broad literature review on turning of hardened steels including optimizing process parameters, cooling requirements, different tool materials etc., are done.

  1. Spinal Projection Neurons Control Turning Behaviors in Zebrafish

    PubMed Central

    Huang, Kuo-Hua; Ahrens, Misha B.; Dunn, Timothy W.; Engert, Florian

    2013-01-01

    Summary Discrete populations of brainstem spinal projection neurons (SPNs) have been shown to exhibit behavior-specific responses during locomotion [1–9], suggesting that separate descending pathways, each dedicated to a specific behavior, control locomotion. In an alternative model, a large variety of motor outputs could be generated from different combinations of a small number of basic motor pathways. We examined this possibility by studying the precise role of ventromedially located hindbrain SPNs (vSPNs) in generating turning behaviors. We found that unilateral laser ablation of vSPNs reduces the tail deflection and cycle period specifically during the first undulation cycle of a swim bout, whereas later tail movements are unaffected. This holds true during phototaxic [10], optomotor [11], dark-flash-induced [12], and spontaneous turns [13], suggesting a universal role of these neurons in controlling turning behaviors. Importantly, we found that the ablation not only abolishes turns but also results in a dramatic increase in the number of forward swims, suggesting that these neurons transform forward swims into turns by introducing turning kinematics into a basic motor pattern of symmetric tail undulations. Finally, we show that vSPN activity is direction specific and graded by turning angle. Together, these results provide a clear example of how a specific motor pattern can be transformed into different behavioral events by the graded activation of a small set of SPNs. PMID:23910662

  2. Anodal tDCS Over the Left DLPFC Did Not Affect the Encoding and Retrieval of Verbal Declarative Information.

    PubMed

    de Lara, Gabriel A; Knechtges, Philipp N; Paulus, Walter; Antal, Andrea

    2017-01-01

    Several studies imply that anodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) can modulate the formation of verbal episodic memories. The aim of this study was to test if tDCS through a multi-electrode Laplacian montage over the left DLPFC could differentially modulate declarative memory performance depending on the application phase. Two groups of healthy participants ( n = 2 × 15) received 1 mA anodal or sham stimulation for 20 min during the encoding or during the recall phase on a delayed cued-recall, using a randomized, double-blinded, repeated-measures experimental design. Memory performance was assessed at two time points: 10 min and 24 h after learning. We found no significant difference between anodal and sham stimulation with regard to the memory scores between conditions (stimulation during encoding or recall) or between time points, suggesting that anodal tDCS over the left DLPFC with these stimulation parameters had no effect on the encoding and the consolidation of associative verbal content.

  3. Anodal tDCS Over the Left DLPFC Did Not Affect the Encoding and Retrieval of Verbal Declarative Information

    PubMed Central

    de Lara, Gabriel A.; Knechtges, Philipp N.; Paulus, Walter; Antal, Andrea

    2017-01-01

    Several studies imply that anodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) can modulate the formation of verbal episodic memories. The aim of this study was to test if tDCS through a multi-electrode Laplacian montage over the left DLPFC could differentially modulate declarative memory performance depending on the application phase. Two groups of healthy participants (n = 2 × 15) received 1 mA anodal or sham stimulation for 20 min during the encoding or during the recall phase on a delayed cued-recall, using a randomized, double-blinded, repeated-measures experimental design. Memory performance was assessed at two time points: 10 min and 24 h after learning. We found no significant difference between anodal and sham stimulation with regard to the memory scores between conditions (stimulation during encoding or recall) or between time points, suggesting that anodal tDCS over the left DLPFC with these stimulation parameters had no effect on the encoding and the consolidation of associative verbal content. PMID:28848378

  4. Giant and thrombosed left ventricular aneurysm

    PubMed Central

    de Agustin, Jose Alberto; de Diego, Jose Juan Gomez; Marcos-Alberca, Pedro; Rodrigo, Jose Luis; Almeria, Carlos; Mahia, Patricia; Luaces, Maria; Garcia-Fernandez, Miguel Angel; Macaya, Carlos; de Isla, Leopoldo Perez

    2015-01-01

    Left ventricular aneurysms are a frequent complication of acute extensive myocardial infarction and are most commonly located at the ventricular apex. A timely diagnosis is vital due to the serious complications that can occur, including heart failure, thromboembolism, or tachyarrhythmias. We report the case of a 78-year-old male with history of previous anterior myocardial infarction and currently under evaluation by chronic heart failure. Transthoracic echocardiogram revealed a huge thrombosed and calcified anteroapical left ventricular aneurysm. Coronary angiography demonstrated that the left anterior descending artery was chronically occluded, and revealed a big and spherical mass with calcified borders in the left hemithorax. Left ventriculogram confirmed that this spherical mass was a giant calcified left ventricular aneurysm, causing very severe left ventricular systolic dysfunction. The patient underwent cardioverter-defibrillator implantation for primary prevention. PMID:26225205

  5. The evolution of cooperative turn-taking in animal conflict

    PubMed Central

    2011-01-01

    Background A fundamental assumption in animal socio-ecology is that animals compete over limited resources. This view has been challenged by the finding that individuals might cooperatively partition resources by "taking turns". Turn-taking occurs when two individuals coordinate their agonistic behaviour in a way that leads to an alternating pattern in who obtains a resource without engaging in costly fights. Cooperative turn-taking has been largely ignored in models of animal conflict and socio-ecological models that explain the evolution of social behaviours based only on contest and scramble competition. Currently it is unclear whether turn-taking should be included in socio-ecological models because the evolution of turn-taking is not well understood. In particular, it is unknown whether turn-taking can evolve when fighting costs and assessment of fighting abilities are not fixed but emerge from evolved within-fight behaviour. We address this problem with an evolutionary agent-based model. Results We found that turn-taking evolves for small resource values, alongside a contest strategy that leads to stable dominance relationships. Turn-taking leads to egalitarian societies with unclear dominance relationships and non-linear dominance hierarchies. Evolutionary stability of turn-taking emerged despite strength differences among individuals and the possibility to evolve within-fight behaviour that allows good assessment of fighting abilities. Evolutionary stability emerged from frequency-dependent effects on fitness, which are modulated by feedbacks between the evolution of within-fight behaviour and the evolution of higher-level conflict strategies. Conclusions Our results reveal the impact of feedbacks between the evolution of within-fight behaviour and the evolution of higher-level conflict strategies, such as turn-taking. Similar feedbacks might be important for the evolution of other conflict strategies such as winner-loser effects or coalitions. However, we

  6. The evolution of cooperative turn-taking in animal conflict.

    PubMed

    Franz, Mathias; van der Post, Daniel; Schülke, Oliver; Ostner, Julia

    2011-11-03

    A fundamental assumption in animal socio-ecology is that animals compete over limited resources. This view has been challenged by the finding that individuals might cooperatively partition resources by "taking turns". Turn-taking occurs when two individuals coordinate their agonistic behaviour in a way that leads to an alternating pattern in who obtains a resource without engaging in costly fights. Cooperative turn-taking has been largely ignored in models of animal conflict and socio-ecological models that explain the evolution of social behaviours based only on contest and scramble competition. Currently it is unclear whether turn-taking should be included in socio-ecological models because the evolution of turn-taking is not well understood. In particular, it is unknown whether turn-taking can evolve when fighting costs and assessment of fighting abilities are not fixed but emerge from evolved within-fight behaviour. We address this problem with an evolutionary agent-based model. We found that turn-taking evolves for small resource values, alongside a contest strategy that leads to stable dominance relationships. Turn-taking leads to egalitarian societies with unclear dominance relationships and non-linear dominance hierarchies. Evolutionary stability of turn-taking emerged despite strength differences among individuals and the possibility to evolve within-fight behaviour that allows good assessment of fighting abilities. Evolutionary stability emerged from frequency-dependent effects on fitness, which are modulated by feedbacks between the evolution of within-fight behaviour and the evolution of higher-level conflict strategies. Our results reveal the impact of feedbacks between the evolution of within-fight behaviour and the evolution of higher-level conflict strategies, such as turn-taking. Similar feedbacks might be important for the evolution of other conflict strategies such as winner-loser effects or coalitions. However, we are not aware of any study that

  7. Bank-to-turn control technology survey for homing missiles

    NASA Technical Reports Server (NTRS)

    Riedel, F. W.

    1980-01-01

    The potential advantages of bank-to-turn control are summarized. Recent and current programs actively investigating bank-to-turn steering are reviewed and critical technology areas concerned with bank-to-turn control are assessed.

  8. 0-6810 : guidelines for applying right-turn slip lanes.

    DOT National Transportation Integrated Search

    2014-10-01

    Rightturn slip lanes are advantageous to : motorists because they reduce delays by : separating right-turning traffic from adjacent : lanes and accommodating higherspeed right : turns. The right-turn slip lane channelizing : island may also pro...

  9. Left ventricular filling under elevated left atrial pressure

    NASA Astrophysics Data System (ADS)

    Gaddam, Manikantam; Samaee, Milad; Santhanakrishnan, Arvind

    2017-11-01

    Left atrial pressure (LAP) is elevated in diastolic dysfunction, where left ventricular (LV) filling is impaired due to increase in ventricular stiffness. The impact of increasing LAP and LV stiffness on intraventricular filling hemodynamics remains unclear. We conducted particle image velocimetry and hemodynamics measurements in a left heart simulator (LHS) under increasing LAP and LV stiffness at a heart rate of 70 bpm. The LHS consisted of a flexible-walled LV physical model fitted within a fluid-filled chamber. LV wall motion was generated by a piston pump that imparted pressure fluctuations in the chamber. Resistance and compliance elements in the flow loop were adjusted to obtain bulk physiological hemodynamics in the least stiff LV model. Two LV models of increasing stiffness were subsequently tested under unchanged loop settings. LAP was varied between 5-20 mm Hg for each LV model, by adjusting fluid level in a reservoir upstream of the LV. For constant LV stiffness, increasing LAP lowered cardiac output (CO), while ejection fraction (EF) and E/A ratio were increased. For constant LAP, increasing LV stiffness lowered CO and EF, and increased E/A ratio. The implications of these altered hemodynamics on intraventricular filling vortex characteristics will be presented.

  10. Left-handed Children in Singapore.

    ERIC Educational Resources Information Center

    Gan, Linda

    1998-01-01

    Used teacher questionnaires to examine incidence of left-handedness in nearly 2,800 Singaporean children, racial differences in this left-handed population, and educational provisions in preschool and primary school. Findings indicated that 7.5% of preschoolers and 6.3% of primary children were left-handed, with a higher proportion being Chinese…

  11. Kinematic properties of the helicopter in coordinated turns

    NASA Technical Reports Server (NTRS)

    Chen, R. T. N.; Jeske, J. A.

    1981-01-01

    A study on the kinematic relationship of the variables of helicopter motion in steady, coordinated turns involving inherent sideslip is described. A set of exact kinematic equations which govern a steady coordinated helical turn about an Earth referenced vertical axis is developed. A precise definition for the load factor parameter that best characterizes a coordinated turn is proposed. Formulas are developed which relate the aircraft angular rates and pitch and roll attitudes to the turn parameters, angle of attack, and inherent sideslip. A steep, coordinated helical turn at extreme angles of attack with inherent sideslip is of primary interest. The bank angle of the aircraft can differ markedly from the tilt angle of the normal load factor. The normal load factor can also differ substantially from the accelerometer reading along the vertical body axis of the aircraft. Sideslip has a strong influence on the pitch attitude and roll rate of the helicopter. Pitch rate is independent of angle of attack in a coordinated turn and in the absence of sideslip, angular rates about the stability axes are independent of the aerodynamic characteristics of the aircraft.

  12. Turning the LHC ring into a new physics search machine

    NASA Astrophysics Data System (ADS)

    Orava, Risto

    2017-03-01

    The LHC Collider Ring is proposed to be turned into an ultimate automatic search engine for new physics in four consecutive phases: (1) Searches for heavy particles produced in Central Exclusive Process (CEP): pp → p + X + p based on the existing Beam Loss Monitoring (BLM) system of the LHC; (2) Feasibility study of using the LHC Ring as a gravitation wave antenna; (3) Extensions to the current BLM system to facilitate precise registration of the selected CEP proton exit points from the LHC beam vacuum chamber; (4) Integration of the BLM based event tagging system together with the trigger/data acquisition systems of the LHC experiments to facilitate an on-line automatic search machine for the physics of tomorrow.

  13. Effect of left ventricular diastolic dysfunction on left atrial appendage function and thrombotic potential in nonvalvular atrial fibrillation.

    PubMed

    Demirçelik, Muhammed Bora; Çetin, Mustafa; Çiçekcioğlu, Hülya; Uçar, Özgül; Duran, Mustafa

    2014-05-01

    We aimed to investigate effects of left ventricular diastolic dysfunction on left atrial appendage functions, spontaneous echo contrast and thrombus formation in patients with nonvalvular atrial fibrillation. In 58 patients with chronic nonvalvular atrial fibrilation and preserved left ventricular systolic function, left atrial appendage functions, left atrial spontaneous echo contrast grading and left ventricular diastolic functions were evaluated using transthoracic and transoesophageal echocardiogram. Patients divided in two groups: Group D (n=30): Patients with diastolic dysfunction, Group N (n=28): Patients without diastolic dysfunction. Categorical variables in two groups were evaluated with Pearson's chi-square or Fisher's exact test. The significance of the lineer correlation between the degree of spontaneous echo contrast (SEC) and clinical measurements was evaluated with Spearman's correlation analysis. Peak pulmonary vein D velocity of the Group D was significantly higher than the Group N (p=0.006). However, left atrial appendage emptying velocity, left atrial appendage lateral wall velocity, peak pulmonary vein S, pulmonary vein S/D ratio were found to be significantly lower in Group D (p=0.028, p<0.001, p<0.001; p<0.001). Statistically significant negative correlation was found between SEC in left atrium and left atrial appendage emptying, filling, pulmonary vein S/D levels and lateral wall velocities respectively (r=-0.438, r=-0.328, r=-0.233, r=-0.447). Left atrial appendage emptying, filling, pulmonary vein S/D levels and lateral wall velocities were significantly lower in SEC 2-3-4 than SEC 1 (p=0.003, p=0.029, p<0.001, p=0.002). In patients with nonvalvular atrial fibrillation and preserved left ventricular ejection fraction, left atrial appendage functions are decreased in patients with left ventricular diastolic dysfunction. Left ventricular diastolic dysfunction may constitute a potential risk for formation of thrombus and stroke.

  14. Characterization of cardiac quiescence from retrospective cardiac computed tomography using a correlation-based phase-to-phase deviation measure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wick, Carson A.; McClellan, James H.; Arepalli, Chesnal D.

    2015-02-15

    Purpose: Accurate knowledge of cardiac quiescence is crucial to the performance of many cardiac imaging modalities, including computed tomography coronary angiography (CTCA). To accurately quantify quiescence, a method for detecting the quiescent periods of the heart from retrospective cardiac computed tomography (CT) using a correlation-based, phase-to-phase deviation measure was developed. Methods: Retrospective cardiac CT data were obtained from 20 patients (11 male, 9 female, 33–74 yr) and the left main, left anterior descending, left circumflex, right coronary artery (RCA), and interventricular septum (IVS) were segmented for each phase using a semiautomated technique. Cardiac motion of individual coronary vessels as wellmore » as the IVS was calculated using phase-to-phase deviation. As an easily identifiable feature, the IVS was analyzed to assess how well it predicts vessel quiescence. Finally, the diagnostic quality of the reconstructed volumes from the quiescent phases determined using the deviation measure from the vessels in aggregate and the IVS was compared to that from quiescent phases calculated by the CT scanner. Three board-certified radiologists, fellowship-trained in cardiothoracic imaging, graded the diagnostic quality of the reconstructions using a Likert response format: 1 = excellent, 2 = good, 3 = adequate, 4 = nondiagnostic. Results: Systolic and diastolic quiescent periods were identified for each subject from the vessel motion calculated using the phase-to-phase deviation measure. The motion of the IVS was found to be similar to the aggregate vessel (AGG) motion. The diagnostic quality of the coronary vessels for the quiescent phases calculated from the aggregate vessel (P{sub AGG}) and IVS (P{sub IV} {sub S}) deviation signal using the proposed methods was comparable to the quiescent phases calculated by the CT scanner (P{sub CT}). The one exception was the RCA, which improved for P{sub AGG} for 18 of the 20 subjects when compared

  15. Prosody as an interactional resource: turn-projection and overlap.

    PubMed

    Wells, B; Macfarlane, S

    1998-01-01

    One aim of current research into talk-in-interaction is to identify the resources that enable recipients to monitor the course of a turn in progress in order to project its upcoming completion. This issue is addressed through analysis of instances of overlapping talk, focusing on their design--that is, their particular prosodic and other linguistic characteristics; their placement--in other words, where precisely they occur in relation to the turn being overlapped; and the subsequent behavior of the coparticipants. Phonetic analysis is combined with interactional techniques developed within Conversation Analysis, to warrant the relevance of categories by reference to the behavior of the participants themselves. As French and Local (1983) found, for an incoming to be treated as turn-competitive, it has to be designed with relatively high pitch and loud volume. These turn-competitive incomings are positioned within the turn in progress, and before the final major accent. By contrast, overlapping incomings positioned after the major accent are not designed as or treated as turn-competitive. On the basis of this analysis, we can define transition relevance place (TRP) as the space between the TRP-projecting accent of the current turn and the onset of the next turn. TRP-projecting accents are identifiable on independent grounds, being phonetically distinct from non-TRP-projecting accents. They thus provide a robust resource for participants to monitor the upcoming completion of the turn.

  16. Turning in the Testbed

    NASA Image and Video Library

    2004-01-13

    This image, taken in the JPL In-Situ Instruments Laboratory or Testbed, shows the view from the front hazard avoidance cameras on the Mars Exploration Rover Spirit after the rover has backed up and turned 45 degrees counterclockwise.

  17. Misplacement of left-sided double-lumen tubes into the right mainstem bronchus: incidence, risk factors and blind repositioning techniques.

    PubMed

    Seo, Jeong-Hwa; Bae, Jun-Yeol; Kim, Hyun Joo; Hong, Deok Man; Jeon, Yunseok; Bahk, Jae-Hyon

    2015-10-28

    Double-lumen endobronchial tubes (DLTs) are commonly advanced into the mainstem bronchus either blindly or by fiberoptic bronchoscopic guidance. However, blind advancement may result in misplacement of left-sided DLTs into the right bronchus. Therefore, incidence, risk factors, and blind repositioning techniques for right bronchial misplacement of left-sided DLTs were investigated. This was an observational cohort study performed on the data depository consecutively collected from patients who underwent intubation of left-sided DLTs for 2 years. Patients' clinical and anatomical characteristics were analyzed to investigate risk factors for DLT misplacements with logistic regression analysis. Moreover, when DLTs were misplaced into the right bronchus, the bronchial tube was withdrawn into the trachea and blindly readvanced without rotation, or with 90° or 180° counterclockwise rotation while the patient's head was turned right. DLTs were inadvertently advanced into the right bronchus in 48 of 1135 (4.2 %) patients. DLT misplacements occurred more frequently in females, in patients of short stature or with narrow trachea and bronchi, and when small-sized DLTs were used. All of these factors were significantly inter-correlated each other (P < 0.001). In 40 of the 48 (83.3 %) patients, blind repositioning was successful. Smaller left-sided DLTs were more frequently misplaced into the right mainstem bronchus than larger DLTs. Moreover, we were usually able to reposition the misplaced DLTs into the left bronchus by using the blind techniques. ClinicalTrials.gov Identifier: NCT01371773.

  18. Spinal projection neurons control turning behaviors in zebrafish.

    PubMed

    Huang, Kuo-Hua; Ahrens, Misha B; Dunn, Timothy W; Engert, Florian

    2013-08-19

    Discrete populations of brainstem spinal projection neurons (SPNs) have been shown to exhibit behavior-specific responses during locomotion [1-9], suggesting that separate descending pathways, each dedicated to a specific behavior, control locomotion. In an alternative model, a large variety of motor outputs could be generated from different combinations of a small number of basic motor pathways. We examined this possibility by studying the precise role of ventromedially located hindbrain SPNs (vSPNs) in generating turning behaviors. We found that unilateral laser ablation of vSPNs reduces the tail deflection and cycle period specifically during the first undulation cycle of a swim bout, whereas later tail movements are unaffected. This holds true during phototaxic [10], optomotor [11], dark-flash-induced [12], and spontaneous turns [13], suggesting a universal role of these neurons in controlling turning behaviors. Importantly, we found that the ablation not only abolishes turns but also results in a dramatic increase in the number of forward swims, suggesting that these neurons transform forward swims into turns by introducing turning kinematics into a basic motor pattern of symmetric tail undulations. Finally, we show that vSPN activity is direction specific and graded by turning angle. Together, these results provide a clear example of how a specific motor pattern can be transformed into different behavioral events by the graded activation of a small set of SPNs. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Science in the Making: Right Hand, Left Hand. III: Estimating historical rates of left-handedness.

    PubMed

    McManus, I C; Moore, James; Freegard, Matthew; Rawles, Richard

    2010-01-01

    The BBC television programme Right Hand, Left Hand, broadcast in August 1953, used a postal questionnaire to ask viewers about their handedness. Respondents were born between 1864 and 1948, and in principle therefore the study provides information on rates of left-handedness in those born in the nineteenth century, a group for which few data are otherwise available. A total of 6,549 responses were received, with an overall rate of left-handedness of 15.2%, which is substantially above that expected for a cohort born in the nineteenth and early twentieth centuries. Left-handers are likely to respond preferentially to surveys about handedness, and the extent of over-response can be estimated in modern control data obtained from a handedness website, from the 1953 BBC data, and from Crichton-Browne's 1907 survey, in which there was also a response bias. Response bias appears to have been growing, being relatively greater in the most modern studies. In the 1953 data there is also evidence that left-handers were more common among later rather than early responders, suggesting that left-handers may have been specifically recruited into the study, perhaps by other left-handers who had responded earlier. In the present study the estimated rate of bias was used to correct the nineteenth-century BBC data, which was then combined with other available data as a mixture of two constrained Weibull functions, to obtain an overall estimate of handedness rates in the nineteenth century. The best estimates are that left-handedness was at its nadir of about 3% for those born between about 1880 and 1900. Extrapolating backwards, the rate of left-handedness in the eighteenth century was probably about 10%, with the decline beginning in about 1780, and reaching around 7% in about 1830, although inevitably there are many uncertainties in those estimates. What does seem indisputable is that rates of left-handedness fell during most of the nineteenth century, only subsequently to rise in

  20. Left inferior frontal cortex and syntax: function, structure and behaviour in patients with left hemisphere damage

    PubMed Central

    Marslen-Wilson, William D.; Randall, Billi; Wright, Paul; Devereux, Barry J.; Zhuang, Jie; Papoutsi, Marina; Stamatakis, Emmanuel A.

    2011-01-01

    For the past 150 years, neurobiological models of language have debated the role of key brain regions in language function. One consistently debated set of issues concern the role of the left inferior frontal gyrus in syntactic processing. Here we combine measures of functional activity, grey matter integrity and performance in patients with left hemisphere damage and healthy participants to ask whether the left inferior frontal gyrus is essential for syntactic processing. In a functional neuroimaging study, participants listened to spoken sentences that either contained a syntactically ambiguous or matched unambiguous phrase. Behavioural data on three tests of syntactic processing were subsequently collected. In controls, syntactic processing co-activated left hemisphere Brodmann areas 45/47 and posterior middle temporal gyrus. Activity in a left parietal cluster was sensitive to working memory demands in both patients and controls. Exploiting the variability in lesion location and performance in the patients, voxel-based correlational analyses showed that tissue integrity and neural activity—primarily in left Brodmann area 45 and posterior middle temporal gyrus—were correlated with preserved syntactic performance, but unlike the controls, patients were insensitive to syntactic preferences, reflecting their syntactic deficit. These results argue for the essential contribution of the left inferior frontal gyrus in syntactic analysis and highlight the functional relationship between left Brodmann area 45 and the left posterior middle temporal gyrus, suggesting that when this relationship breaks down, through damage to either region or to the connections between them, syntactic processing is impaired. On this view, the left inferior frontal gyrus may not itself be specialized for syntactic processing, but plays an essential role in the neural network that carries out syntactic computations. PMID:21278407

  1. Stepping in Place While Voluntarily Turning Around Produces a Long-Lasting Posteffect Consisting in Inadvertent Turning While Stepping Eyes Closed

    PubMed Central

    2016-01-01

    Training subjects to step in place on a rotating platform while maintaining a fixed body orientation in space produces a posteffect consisting in inadvertent turning around while stepping in place eyes closed (podokinetic after-rotation, PKAR). We tested the hypothesis that voluntary turning around while stepping in place also produces a posteffect similar to PKAR. Sixteen subjects performed 12 min of voluntary turning while stepping around their vertical axis eyes closed and 12 min of stepping in place eyes open on the center of a platform rotating at 60°/s (pretests). Then, subjects continued stepping in place eyes closed for at least 10 min (posteffect). We recorded the positions of markers fixed to head, shoulder, and feet. The posteffect of voluntary turning shared all features of PKAR. Time decay of angular velocity, stepping cadence, head acceleration, and ratio of angular velocity after to angular velocity before were similar between both protocols. Both postrotations took place inadvertently. The posteffects are possibly dependent on the repeated voluntary contraction of leg and foot intrarotating pelvic muscles that rotate the trunk over the stance foot, a synergy common to both protocols. We propose that stepping in place and voluntary turning can be a scheme ancillary to the rotating platform for training body segment coordination in patients with impairment of turning synergies of various origin. PMID:27635264

  2. Agraphia of the left hand with dysfunction of the left superior parietal region without callosal lesions.

    PubMed

    Kinno, Ryuta; Ohashi, Hideaki; Mori, Yukiko; Shiromaru, Azusa; Ono, Kenjiro

    2018-03-01

    A 28-year-old right-handed man noticed weakness in his legs, three days after an ephedrine overdose. Initial brain magnetic resonance imaging showed lesions in the parietal regions bilaterally. Computed tomography angiography showed segmental and multifocal vasoconstriction of the cerebral arteries. After treatment, clinical and radiological findings resolved, suggesting the patient had reversible cerebral vasoconstriction syndrome with posterior reversible encephalopathy syndrome. However, he had residual agraphia of the left hand. Language testing revealed no difficulties in oral expression, auditory comprehension, understanding of written language, or writing with the right hand. I-123 iodoamphetamine single-photon emission computed tomography showed residual dysfunction in the left superior parietal lobule. There were no apparent signs of other disconnection syndromes or neuroimaging abnormalities in the corpus callosum. We diagnosed left-hand agraphia due to left parietal dysfunction. Our case suggests that left superior parietal dysfunction without callosal lesions is a possible cause of left-hand agraphia. Neural mechanisms for writing with the right or left hand may be separable at the cortical level.

  3. Design, analysis and testing of a new piezoelectric tool actuator for elliptical vibration turning

    NASA Astrophysics Data System (ADS)

    Lin, Jieqiong; Han, Jinguo; Lu, Mingming; Yu, Baojun; Gu, Yan

    2017-08-01

    A new piezoelectric tool actuator (PETA) for elliptical vibration turning has been developed based on a hybrid flexure hinge connection. Two double parallel four-bar linkage mechanisms and two right circular flexure hinges were chosen to guide the motion. The two input displacement directional stiffness were modeled according to the principle of virtual work modeling method and the kinematic analysis was conducted theoretically. Finite element analysis was used to carry out static and dynamic analyses. To evaluate the performance of the developed PETA, off-line experimental tests were carried out to investigate the step responses, motion strokes, resolutions, parasitic motions, and natural frequencies of the PETA along the two input directions. The relationship between input displacement and output displacement, as well as the tool tip’s elliptical trajectory in different phase shifts was analyzed. By using the developed PETA mechanism, micro-dimple patterns were generated as the preliminary application to demonstrate the feasibility and efficiency of PETA for elliptical vibration turning.

  4. Steady properly-banked turns of turbojet-propelled airplanes

    NASA Technical Reports Server (NTRS)

    Miele, Angelo

    1955-01-01

    The problem of a jet-propelled airplane held in a steady turn is treated both in the very general case and also in the particular case when the polar curve can be approximated by a parabola. Once the general solution has been obtained, some typical maneuvers are next studied such as, the turn of maximum bank, of maximum angular velocity, and of minimum radius of curvature. After a brief comparison is made between the turning characteristics of conventional airplanes and jet airplanes, and after the effect of compressibility upon the turn is examined, the effects of the salient aerodynamic and structural parameters upon the behavior of the plane in curvilinear flight are summarized in the conclusions.

  5. Left ventricular assist device implantation via left thoracotomy: alternative to repeat sternotomy.

    PubMed

    Pierson, Richard N; Howser, Renee; Donaldson, Terri; Merrill, Walter H; Dignan, Rebecca J; Drinkwater, Davis C; Christian, Karla G; Butler, Javed; Chomsky, Don; Wilson, John R; Clark, Rick; Davis, Stacy F

    2002-03-01

    Repeat sternotomy for left ventricular assist device insertion may result in injury to the right heart or patent coronary grafts, complicating intraoperative and postoperative management. In 4 critically ill patients, left thoracotomy was used as an alternative to repeat sternotomy. Anastomosis of the outflow conduit to the descending thoracic aorta provided satisfactory hemodynamic support.

  6. Left Superior Vena Cava Draining Into Left Atrium in Tetralogy of Fallot-Four Cases of a Rare Association.

    PubMed

    Ramman, Tarun Raina; Dutta, Nilanjan; Chowdhuri, Kuntal Roy; Agrawal, Sunny; Girotra, Sumir; Azad, Sushil; Radhakrishnan, Sitaraman; Iyer, Parvathi Unninayar; Iyer, Krishna Subramony

    2018-01-01

    Persistent left superior vena cava is a common congenital anomaly of the thoracic venous system. Left superior vena cava draining into left atrium is a malformation of sinus venosus and caval system. The anomaly may be a cause of unexplained hypoxia even in adults. It may give rise to various diagnostic and technical challenges during cardiac catheterization and open-heart surgery. It is often detected serendipitously during diagnostic workup. Isolated left superior vena cava opening into left atrium is very commonly associated with other congenital heart defects. But tetralogy of Fallot is very rarely associated with persistent left superior vena cava which drains into left atrium. We report four such cases who underwent surgical correction successfully.

  7. Consciousness wanted, attention found: Reasons for the advantage of the left visual field in identifying T2 among rapidly presented series.

    PubMed

    Verleger, Rolf; Śmigasiewicz, Kamila

    2015-09-01

    Everyday experience suggests that people are equally aware of events in both hemi-fields. However, when two streams of stimuli are rapidly presented left and right containing two targets, the second target is better identified in the left than in the right visual field. This might be considered evidence for a right-hemisphere advantage in generating conscious percepts. However, this putative asymmetry of conscious perception cannot be measured independently of participants' access to their conscious percepts, and there is actually evidence from split-brain patients for the reverse, left-hemisphere advantage in having access to conscious percepts. Several other topics were studied in search of the responsible mechanism, among others: Mutual inhibition of hemispheres, cooperation of hemispheres in perceiving midline stimuli, and asymmetries in processing various perceptual inputs. Directing attention by salient cues turned out to be one of the few mechanisms capable of modifying the left visual-field advantage in this paradigm. Thus, this left visual-field advantage is best explained by the notion of a right-hemisphere advantage in directing attention to salient events. Dovetailing with the pathological asymmetries of attention after right-hemisphere lesions and with asymmetries of brain activation when healthy participants shift their attention, the present results extend that body of evidence by demonstrating unusually large and reliable behavioral asymmetries for attention-directing processes in healthy participants. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Abnormal turning behaviour, GABAergic inhibition and the degeneration of astrocytes in ovine Tribulus terrestris motor neuron disease.

    PubMed

    Bourke, C A

    2006-01-01

    To observe the clinical signs of sheep affected by Tribulus terrestris motor neuron disease, to ascertain their response to striatal dopamine reducing drugs, and to examine their brains and spinal cords for microscopic changes. Twenty-eight sheep displaying well developed clinical signs of the disorder were observed. Twenty-two of these and 22 normal sheep were then randomly allocated to three groups and treated with diazepam, chlorpromazine, or xylazine. The time that it took an animal to return to a standing position following drug administration was recorded. The brain and complete spinal cord were removed from each of the other six affected sheep and fixed in formalin. Brains were sectioned throughout at 5 mm intervals and spinal cords at 10 mm intervals. All tissues were paraffin embedded and examined by light microscopy. A few samples were examined by electron microscopy. Clinical signs included postural asymmetry with a right:left body-side dominance within the group of 50:50, unequal flaccid paresis in the pelvic limbs, extensor muscle atrophy and adduction of the weaker pelvic limb, and concurrent abduction of the stronger. Forward motion followed either a fixed left or right hand curved trajectory, the sheep no longer being able to choose which. Twelve animals intermittently displayed rotational behaviour that involved loss of postural balance without locomotor activation. The administration of diazepam, chlorpromazine, or xylazine caused limb paresis and sedation, with affected sheep being slower than normal sheep by factors of 8, 3 and 2 respectively, to return to a standing position. There were scattered areas of mild Wallerian degeneration throughout the spinal cord, and in both the brain and the cord there were small numbers of degenerate astrocytes containing novel cytoplasmic pigment granules. Affected sheep had a dysfunction in the control of directional change and this provides a new insight into the normal mechanism for 'turning' in quadrupeds

  9. 14 CFR 417.209 - Malfunction turn analysis.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... nozzle burn-through. For each cause of a malfunction turn, the analysis must establish the launch vehicle... the launch vehicle's turning capability in the event of a malfunction during flight. A malfunction... launch vehicle is capable. (4) The time, as a single value or a probability time distribution, when each...

  10. 14 CFR 417.209 - Malfunction turn analysis.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... nozzle burn-through. For each cause of a malfunction turn, the analysis must establish the launch vehicle... the launch vehicle's turning capability in the event of a malfunction during flight. A malfunction... launch vehicle is capable. (4) The time, as a single value or a probability time distribution, when each...

  11. Exceptional running and turning performance in a mite.

    PubMed

    Rubin, Samuel; Young, Maria Ho-Yan; Wright, Jonathan C; Whitaker, Dwight L; Ahn, Anna N

    2016-03-01

    The Southern California endemic mite Paratarsotomus macropalpis was filmed in the field on a concrete substrate and in the lab to analyze stride frequency, gait and running speed under different temperature conditions and during turning. At ground temperatures ranging from 45 to 60 °C, mites ran at a mean relative speed of 192.4 ± 2.1 body lengths (BL) s(-1), exceeding the highest previously documented value for a land animal by 12.5%. Stride frequencies were also exceptionally high (up to 135 Hz), and increased with substrate temperature. Juveniles exhibited higher relative speeds than adults and possess proportionally longer legs, which allow for greater relative stride lengths. Although mites accelerated and decelerated rapidly during straight running (7.2 ± 1.2 and -10.1 ± 2.1 m s(-2), respectively), the forces involved were comparable to those found in other animals. Paratarsotomus macropalpis employs an alternating tetrapod gait during steady running. Shallow turns were accomplished by a simple asymmetry in stride length. During tight turns, mites pivoted around the tarsus of the inside third leg (L3), which thus behaved like a grappling hook. Pivot turns were characterized by a 42% decrease in turning radius and a 40% increase in angular velocity compared with non-pivot turns. The joint angle amplitudes of the inner L2 and L3 were negligible during a pivot turn. While exceptional, running speeds in P. macropalpis approximate values predicted from inter-specific scaling relationships. © 2016. Published by The Company of Biologists Ltd.

  12. Predicting β-Turns in Protein Using Kernel Logistic Regression

    PubMed Central

    Elbashir, Murtada Khalafallah; Sheng, Yu; Wang, Jianxin; Wu, FangXiang; Li, Min

    2013-01-01

    A β-turn is a secondary protein structure type that plays a significant role in protein configuration and function. On average 25% of amino acids in protein structures are located in β-turns. It is very important to develope an accurate and efficient method for β-turns prediction. Most of the current successful β-turns prediction methods use support vector machines (SVMs) or neural networks (NNs). The kernel logistic regression (KLR) is a powerful classification technique that has been applied successfully in many classification problems. However, it is often not found in β-turns classification, mainly because it is computationally expensive. In this paper, we used KLR to obtain sparse β-turns prediction in short evolution time. Secondary structure information and position-specific scoring matrices (PSSMs) are utilized as input features. We achieved Q total of 80.7% and MCC of 50% on BT426 dataset. These results show that KLR method with the right algorithm can yield performance equivalent to or even better than NNs and SVMs in β-turns prediction. In addition, KLR yields probabilistic outcome and has a well-defined extension to multiclass case. PMID:23509793

  13. Predicting β-turns in protein using kernel logistic regression.

    PubMed

    Elbashir, Murtada Khalafallah; Sheng, Yu; Wang, Jianxin; Wu, Fangxiang; Li, Min

    2013-01-01

    A β-turn is a secondary protein structure type that plays a significant role in protein configuration and function. On average 25% of amino acids in protein structures are located in β-turns. It is very important to develope an accurate and efficient method for β-turns prediction. Most of the current successful β-turns prediction methods use support vector machines (SVMs) or neural networks (NNs). The kernel logistic regression (KLR) is a powerful classification technique that has been applied successfully in many classification problems. However, it is often not found in β-turns classification, mainly because it is computationally expensive. In this paper, we used KLR to obtain sparse β-turns prediction in short evolution time. Secondary structure information and position-specific scoring matrices (PSSMs) are utilized as input features. We achieved Q total of 80.7% and MCC of 50% on BT426 dataset. These results show that KLR method with the right algorithm can yield performance equivalent to or even better than NNs and SVMs in β-turns prediction. In addition, KLR yields probabilistic outcome and has a well-defined extension to multiclass case.

  14. Cilia in vertebrate left-right patterning.

    PubMed

    Dasgupta, Agnik; Amack, Jeffrey D

    2016-12-19

    Understanding how left-right (LR) asymmetry is generated in vertebrate embryos is an important problem in developmental biology. In humans, a failure to align the left and right sides of cardiovascular and/or gastrointestinal systems often results in birth defects. Evidence from patients and animal models has implicated cilia in the process of left-right patterning. Here, we review the proposed functions for cilia in establishing LR asymmetry, which include creating transient leftward fluid flows in an embryonic 'left-right organizer'. These flows direct asymmetric activation of a conserved Nodal (TGFβ) signalling pathway that guides asymmetric morphogenesis of developing organs. We discuss the leading hypotheses for how cilia-generated asymmetric fluid flows are translated into asymmetric molecular signals. We also discuss emerging mechanisms that control the subcellular positioning of cilia and the cellular architecture of the left-right organizer, both of which are critical for effective cilia function during left-right patterning. Finally, using mosaic cell-labelling and time-lapse imaging in the zebrafish embryo, we provide new evidence that precursor cells maintain their relative positions as they give rise to the ciliated left-right organizer. This suggests the possibility that these cells acquire left-right positional information prior to the appearance of cilia.This article is part of the themed issue 'Provocative questions in left-right asymmetry'. © 2016 The Author(s).

  15. Optical Neasurements Of Diamond-Turned Surfaces

    NASA Astrophysics Data System (ADS)

    Politch, Jacob

    1989-07-01

    We describe here a system for measuring very accurately diamond-turned surfaces. This system is based on heterodyne interfercmetry and measures surface height variations with an accuracy of 4A, and the spatial resolution is 1 micrometer. Fran the measured data we have calculated the statistical properties of the surface - enabling us to identify the spatial frequencies caused by the vibrations of the diamond - turning machine and the measuring machine as well as the frequency of the grid.

  16. Precision lens assembly with alignment turning system

    NASA Astrophysics Data System (ADS)

    Ho, Cheng-Fang; Huang, Chien-Yao; Lin, Yi-Hao; Kuo, Hui-Jean; Kuo, Ching-Hsiang; Hsu, Wei-Yao; Chen, Fong-Zhi

    2017-10-01

    The poker chip assembly with high precision lens barrels is widely applied to ultra-high performance optical system. ITRC applies the poker chip assembly technology to the high numerical aperture objective lenses and lithography projection lenses because of its high efficiency assembly process. In order to achieve high precision lens cell for poker chip assembly, an alignment turning system (ATS) is developed. The ATS includes measurement, alignment and turning modules. The measurement module is equipped with a non-contact displacement sensor (NCDS) and an autocollimator (ACM). The NCDS and ACM are used to measure centration errors of the top and the bottom surface of a lens respectively; then the amount of adjustment of displacement and tilt with respect to the rotational axis of the turning machine for the alignment module can be determined. After measurement, alignment and turning processes on the ATS, the centration error of a lens cell with 200 mm in diameter can be controlled within 10 arcsec. Furthermore, a poker chip assembly lens cell with three sub-cells is demonstrated, each sub-cells are measured and accomplished with alignment and turning processes. The lens assembly test for five times by each three technicians; the average transmission centration error of assembly lens is 12.45 arcsec. The results show that ATS can achieve high assembly efficiency for precision optical systems.

  17. Left Paraduodenal Hernia.

    PubMed

    Martins, Aires; Gonçalves, Álvaro; Almeida, Teresa; Gomes, Rui; Lomba, João; Midões, Alberto

    2018-05-01

    Left paraduodenal hernia is an entrapment of the small bowel into the Landzert fossa, an unusual congenital peritoneal defect behind the descending mesocolon that results from failure of part of the descending mesocolon to fuse with the posterior parietal peritoneum (Doishita et al. in Radiographics, 36(1): 88-106, 2016). This fossa is reported to be present in approximately 2% of autopsy bodies. The authors present a case of a left paraduodenal hernia in a young woman.

  18. Atomic disorder, phase transformation, and phase restoration in Co3Sn2

    NASA Astrophysics Data System (ADS)

    di, L. M.; Zhou, G. F.; Bakker, H.

    1993-03-01

    The behavior of the intermetallic compound Co3Sn2 upon ball milling was studied by x-ray diffraction, high-field-magnetization measurements, and subsequently by differential scanning calorimetry. It turns out that starting from the stoichiometric-ordered compound, mechanical attrition of Co3Sn2 generates atomic disorder in the early stage of milling. The nonequilibrium phase transformation from the low-temperature phase with orthorhombic structure to the high-temperature phase with a hexagonal structure was observed in the intermediate stage of milling. It was accompanied by the creation of increasing atomic disorder. After long milling periods, the phase transformation was completed and the atomic disordering became saturated. All the physical parameters measured in the present work remained constant during this period. The above outcome was confirmed by comparison with the high-temperature phase thermally induced by quenching. The good agreement of the results obtained by different techniques proves that the ball milling generates well-defined metastable states in Co3Sn2.

  19. Cheetahs, Acinonyx jubatus, balance turn capacity with pace when chasing prey

    PubMed Central

    Wilson, John W.; Mills, Michael G. L.; Wilson, Rory P.; Peters, Gerrit; Mills, Margaret E. J.; Speakman, John R.; Durant, Sarah M.; Bennett, Nigel C.; Marks, Nikki J.; Scantlebury, Michael

    2013-01-01

    Predator–prey interactions are fundamental in the evolution and structure of ecological communities. Our understanding, however, of the strategies used in pursuit and evasion remains limited. Here, we report on the hunting dynamics of the world's fastest land animal, the cheetah, Acinonyx jubatus. Using miniaturized data loggers, we recorded fine-scale movement, speed and acceleration of free-ranging cheetahs to measure how hunting dynamics relate to chasing different sized prey. Cheetahs attained hunting speeds of up to 18.94 m s−1 and accelerated up to 7.5 m s−2 with greatest angular velocities achieved during the terminal phase of the hunt. The interplay between forward and lateral acceleration during chases showed that the total forces involved in speed changes and turning were approximately constant over time but varied with prey type. Thus, rather than a simple maximum speed chase, cheetahs first accelerate to decrease the distance to their prey, before reducing speed 5–8 s from the end of the hunt, so as to facilitate rapid turns to match prey escape tactics, varying the precise strategy according to prey species. Predator and prey thus pit a fine balance of speed against manoeuvring capability in a race for survival. PMID:24004493

  20. Cheetahs, Acinonyx jubatus, balance turn capacity with pace when chasing prey.

    PubMed

    Wilson, John W; Mills, Michael G L; Wilson, Rory P; Peters, Gerrit; Mills, Margaret E J; Speakman, John R; Durant, Sarah M; Bennett, Nigel C; Marks, Nikki J; Scantlebury, Michael

    2013-10-23

    Predator-prey interactions are fundamental in the evolution and structure of ecological communities. Our understanding, however, of the strategies used in pursuit and evasion remains limited. Here, we report on the hunting dynamics of the world's fastest land animal, the cheetah, Acinonyx jubatus. Using miniaturized data loggers, we recorded fine-scale movement, speed and acceleration of free-ranging cheetahs to measure how hunting dynamics relate to chasing different sized prey. Cheetahs attained hunting speeds of up to 18.94 m s(-1) and accelerated up to 7.5 m s(-2) with greatest angular velocities achieved during the terminal phase of the hunt. The interplay between forward and lateral acceleration during chases showed that the total forces involved in speed changes and turning were approximately constant over time but varied with prey type. Thus, rather than a simple maximum speed chase, cheetahs first accelerate to decrease the distance to their prey, before reducing speed 5-8 s from the end of the hunt, so as to facilitate rapid turns to match prey escape tactics, varying the precise strategy according to prey species. Predator and prey thus pit a fine balance of speed against manoeuvring capability in a race for survival.

  1. Identifying protein β-turns with vibrational Raman optical activity.

    PubMed

    Weymuth, Thomas; Jacob, Christoph R; Reiher, Markus

    2011-04-18

    β-turns belong to the most important secondary structure elements in proteins. On the basis of density functional calculations, vibrational Raman optical activity signatures of different types of β-turns are established and compared as well as related to other signatures proposed in the literature earlier. Our findings indicate that there are much more characteristic ROA signals of β-turns than have been hitherto suggested. These suggested signatures are, however, found to be valid for the most important type of β-turns. Moreover, we compare the influence of different amino acid side chains on these signatures and investigate the discrimination of β-turns from other secondary structure elements, namely α- and 3(10)-helices. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Structural and sequence features of two residue turns in beta-hairpins.

    PubMed

    Madan, Bharat; Seo, Sung Yong; Lee, Sun-Gu

    2014-09-01

    Beta-turns in beta-hairpins have been implicated as important sites in protein folding. In particular, two residue β-turns, the most abundant connecting elements in beta-hairpins, have been a major target for engineering protein stability and folding. In this study, we attempted to investigate and update the structural and sequence properties of two residue turns in beta-hairpins with a large data set. For this, 3977 beta-turns were extracted from 2394 nonhomologous protein chains and analyzed. First, the distribution, dihedral angles and twists of two residue turn types were determined, and compared with previous data. The trend of turn type occurrence and most structural features of the turn types were similar to previous results, but for the first time Type II turns in beta-hairpins were identified. Second, sequence motifs for the turn types were devised based on amino acid positional potentials of two-residue turns, and their distributions were examined. From this study, we could identify code-like sequence motifs for the two residue beta-turn types. Finally, structural and sequence properties of beta-strands in the beta-hairpins were analyzed, which revealed that the beta-strands showed no specific sequence and structural patterns for turn types. The analytical results in this study are expected to be a reference in the engineering or design of beta-hairpin turn structures and sequences. © 2014 Wiley Periodicals, Inc.

  3. Two cases of left superior vena cava draining directly to a left atrium with a normal coronary sinus.

    PubMed Central

    Wiles, H B

    1991-01-01

    The most common variation in the thoracic systemic venous system is a persistent left superior vena cava draining to a coronary sinus. A rare anomaly is a persistent left superior vena cava connecting directly to the left atrium. In this situation it is believed that the coronary sinus must be absent. This report describes two cases of a persistent left superior vena cava draining to a left atrium with a normal coronary sinus. Images PMID:2015125

  4. Acoustic energy exchange through flow turning

    NASA Astrophysics Data System (ADS)

    Baum, Joseph D.

    1987-01-01

    A numerical investigation of the mechanisms of acoustic energy exchange between the mean and acoustic flow fields in resonance chambers, such as rocket engines, is reported. A noniterative linearized block implicit scheme was used to solve the time-dependent compressible Navier-Stokes equations. Two test cases were investigated: acoustic wave propagation in a tube with a coexisting sheared mean flow (the refraction test) and acoustic wave propagation in a tube where the mean sheared flow was injected into the tube through its lateral boundary (the flow turning study). For flow turning, significant excitation of mean flow energy was observed at two locations: at the edge of the acoustic boundary layer and within a zone adjacent to the acoustic boundary layer extending up to 0.1 radii away from the wall. A weaker streaming effect was observed for the refraction study, and only at the edge of the acoustic boundary layer. The total dissipation for the flow turning test was twice the dissipation for refraction.

  5. A comparison of subtalar joint motion during anticipated medial cutting turns and level walking using a multi-segment foot model.

    PubMed

    Jenkyn, T R; Shultz, R; Giffin, J R; Birmingham, T B

    2010-02-01

    The weight-bearing in-vivo kinematics and kinetics of the talocrural joint, subtalar joint and joints of the foot were quantified using optical motion analysis. Twelve healthy subjects were studied during level walking and anticipated medial turns at self-selected pace. A multi-segment model of the foot using skin-mounted marker triads tracked four foot segments: the hindfoot, midfoot, lateral and medial forefoot. The lower leg and thigh were also tracked. Motion between each of the segments could occur in three degrees of rotational freedom, but only six inter-segmental motions were reported in this study: (1) talocrural dorsi-plantar-flexion, (2) subtalar inversion-eversion, (3) frontal plane hindfoot motion, (4) transverse plane hindfoot motion, (5) forefoot supination-pronation twisting and (6) the height-to-length ratio of the medial longitudinal arch. The motion at the subtalar joint during stance phase of walking (eversion then inversion) was reversed during a turning task (inversion then eversion). The external subtalar joint moment was also changed from a moderate eversion moment during walking to a larger inversion moment during the turn. The kinematics of the talocrural joint and the joints of the foot were similar between these two tasks. During a medial turn, the subtalar joint may act to maintain the motions in the foot and talocrural joint that occur during level walking. This is occurring despite the conspicuously different trajectory of the centre of mass of the body. This may allow the foot complex to maintain its function of energy absorption followed by energy return during stance phase that is best suited to level walking. Copyright 2009 Elsevier B.V. All rights reserved.

  6. Does the timing of parental migration matter for child growth? A life course study on left-behind children in rural China.

    PubMed

    Zhang, Nan; Bécares, Laia; Chandola, Tarani

    2015-09-25

    China's unprecedented internal migration has left 61 million rural children living apart from parents. This study investigates how being left behind is associated with children's growth, by examining children's height and weight trajectories by age, testing the accumulation and critical period life course hypotheses. Data were drawn from five waves of the China Health and Nutrition Survey (CHNS). Multiple cohorts of children under 6 years old from 1997-2009 were examined (N = 2,555). Growth curve models investigated whether height and weight trajectories differ for children who were left behind at different stages of the life course: in early childhood (from ages 0-5 but not afterwards), in later childhood (from ages 6 to 17 only), and in both early and later childhood (from ages 0-5 and from ages 6-17), compared to their peers from intact households. Boys who were left behind at different life stages of childhood differed in height and weight growth compared with boys from intact families. No significant associations were found for girls. As young boys turned into adolescents, those left behind in early childhood tended to have slower height growth and weight gain than their peers from intact households. There was a 2.8 cm difference in the predicted heights of boys who were left behind in early childhood compared to boys from intact households, by the age of 14. Similarly, the difference in weight between the two groups of boys was 5.3 kg by the age of 14. Being left behind during early childhood, as compared to not being left behind, could lead to slower growth rates of height and weight for boys. The life course approach adopted in this study suggests that early childhood is a critical period of children's growth in later life, especially for boys who are left behind. The gender paradox in China, where sons are preferred, but being left behind appears to affect boys more than girls, needs further exploration.

  7. Time-varying impedance of the human ankle in the sagittal and frontal planes during straight walk and turning steps.

    PubMed

    Ficanha, Evandro M; Ribeiro, Guilherme A; Knop, Lauren; Rastgaar, Mo

    2017-07-01

    This paper describes the methods and experiment protocols for estimation of the human ankle impedance during turning and straight line walking. The ankle impedance of two human subjects during the stance phase of walking in both dorsiflexion plantarflexion (DP) and inversion eversion (IE) were estimated. The impedance was estimated about 8 axes of rotations of the human ankle combining different amounts of DP and IE rotations, and differentiating among positive and negative rotations at 5 instants of the stance length (SL). Specifically, the impedance was estimated at 10%, 30%, 50%, 70% and 90% of the SL. The ankle impedance showed great variability across time, and across the axes of rotation, with consistent larger stiffness and damping in DP than IE. When comparing straight walking and turning, the main differences were in damping at 50%, 70%, and 90% of the SL with an increase in damping at all axes of rotation during turning.

  8. [Memorization of Sequences of Movements of the Right and the Left Hand by Right- and Left-Handers].

    PubMed

    Bobrova, E V; Bogacheva, I N; Lyakhovetskii, V A; Fabinskaja, A A; Fomina, E V

    2015-01-01

    We analyzed the errors of right- and left-handers when performing memorized sequences by the left or the right hand during the task which activates positional coding: after 6-10 times the order of movements changed (the positions remained the same during all task). The task was first performed by one ("initial") hand, and then by another one ("continuing"); there were 2 groups of right-handers and 2 groups of left-handers. It was found that the pattern of errors during the task performance by the initial hand is similar in right- and left-handers both for the dominant and non-dominant hand. The information about the previous positions after changing the order of elements is used in the sequences for subdominant hands and not used in the sequences for dominant ones. After changing the hand, right- and left-handers show different patterns of errors ("non-symmetrical"). Thus, the errors of right- and left-handers are "symmetrical" at the early stages of task performance, while the transfer of this motor skill in right-and left-handers occurs in different ways.

  9. Diamond turning of Si and Ge single crystals

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Blake, P.; Scattergood, R.O.

    Single-point diamond turning studies have been completed on Si and Ge crystals. A new process model was developed for diamond turning which is based on a critical depth of cut for plastic flow-to-brittle fracture transitions. This concept, when combined with the actual machining geometry for single-point turning, predicts that {open_quotes}ductile{close_quotes} machining is a combined action of plasticity and fracture. Interrupted cutting experiments also provide a meant to directly measure the critical depth parameter for given machining conditions.

  10. ω-Turn: a novel β-turn mimic in globular proteins stabilized by main-chain to side-chain C−H···O interaction.

    PubMed

    Dhar, Jesmita; Chakrabarti, Pinak; Saini, Harpreet; Raghava, Gajendra Pal Singh; Kishore, Raghuvansh

    2015-02-01

    Mimicry of structural motifs is a common feature in proteins. The 10-membered hydrogen-bonded ring involving the main-chain C − O in a β-turn can be formed using a side-chain carbonyl group leading to Asx-turn. We show that the N − H component of hydrogen bond can be replaced by a C(γ) -H group in the side chain, culminating in a nonconventional C − H···O interaction. Because of its shape this β-turn mimic is designated as ω-turn, which is found to occur ∼ three times per 100 residues. Three residues (i to i + 2) constitute the turn with the C − H···O interaction occurring between the terminal residues, constraining the torsion angles ϕi + 1, ψi + 1, ϕi + 2 and χ'1(i + 2) (using the interacting C(γ) atom). Based on these angles there are two types of ω-turns, each of which can be further divided into two groups. C(β) -branched side-chains, and Met and Gln have high propensities to occur at i + 2; for the last two residues the carbonyl oxygen may participate in an additional interaction involving the S and amino group, respectively. With Cys occupying the i + 1 position, such turns are found in the metal-binding sites. N-linked glycosylation occurs at the consensus pattern Asn-Xaa-Ser/Thr; with Thr at i + 2, the sequence can adopt the secondary structure of a ω-turn, which may be the recognition site for protein modification. Location between two β-strands is the most common occurrence in protein tertiary structure, and being generally exposed ω-turn may constitute the antigenic determinant site. It is a stable scaffold and may be used in protein engineering and peptide design. © 2014 Wiley Periodicals, Inc.

  11. Phase-Controlled Polarization Modulators

    NASA Technical Reports Server (NTRS)

    Chuss, D. T.; Wollack, E. J.; Novak, G.; Moseley, S. H.; Pisano, G.; Krejny, M.; U-Yen, K.

    2012-01-01

    We report technology development of millimeter/submillimeter polarization modulators that operate by introducing a a variable, controlled phase delay between two orthogonal polarization states. The variable-delay polarization modulator (VPM) operates via the introduction of a variable phase delay between two linear orthogonal polarization states, resulting in a variable mapping of a single linear polarization into a combination of that Stokes parameter and circular (Stokes V) polarization. Characterization of a prototype VPM is presented at 350 and 3000 microns. We also describe a modulator in which a variable phase delay is introduced between right- and left- circular polarization states. In this architecture, linear polarization is fully modulated. Each of these devices consists of a polarization diplexer parallel to and in front of a movable mirror. Modulation involves sub-wavelength translations of the mirror that change the magnitude of the phase delay.

  12. The Left Atrial Appendage Revised

    PubMed Central

    Evora, Paulo Roberto Barbosa; Menardi, Antonio Carlos; Celotto, Andrea Carla; Albuquerque, Agnes Afrodite S.; Chagas, Hannah Miranda Araujo; Rodrigues, Alfredo José

    2017-01-01

    Nonvalvular atrial fibrillation is associated with a 4- to 5-fold strokes increase and may be responsible for 15% to 20% of all strokes in the elderly. In this scenario, the left atrial appendage thrombus would be the associated with 90% of cases. The use of anticoagulants, percutaneous devices, and the left atrial appendage surgical exclusion is still an open discussion. For left atrial appendage procedures, relevant anatomic spatial relationships have to be emphasized, besides the chance of the normal physiological functioning would be eliminated with the proceedings. There are evidences that the left atrial appendage closure during routine cardiac surgery is significantly associated with an increased risk of early postoperative atrial fibrillation. Therefore, the purpose of this review is to focus basic aspects for continuous medical education. In summary, the rationale of this text is to emphasize anatomical and pharmacological aspects involved in the simple surgical exclusion of left atrial appendage under cardiopulmonary bypass. There are several operative techniques, but to conclude this revision it will present one of them based on the discussed basic sciences. PMID:29267615

  13. High voltage and current, gate assisted, turn-off thyristor development

    NASA Technical Reports Server (NTRS)

    Nowalk, T. P.; Brewster, J. B.; Kao, Y. C.

    1972-01-01

    An improved high speed power switch with unique turn-off capability was developed. This gate assisted turn-off thyristor (GATT) was rated 1000 volts and 100 amperes with turn-off times of 2 microseconds. Fifty units were delivered for evaluation. In addition, test circuits designed to relate to the series inverter application were built and demonstrated. In the course of this work it was determined that the basic device design is adequate to meet the static characteristics and dynamic turn-off specification. It was further determined that the turn-on specification is critically dependent on the gate drive circuit due to the distributive nature of the cathode-gate geometry. Future work should emphasize design modifications which reduce the gate current required for fast turn-on, thereby opening the way to higher power (current) devices.

  14. Diamond turning machine controller implementation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Garrard, K.P.; Taylor, L.W.; Knight, B.F.

    The standard controller for a Pnuemo ASG 2500 Diamond Turning Machine, an Allen Bradley 8200, has been replaced with a custom high-performance design. This controller consists of four major components. Axis position feedback information is provided by a Zygo Axiom 2/20 laser interferometer with 0.1 micro-inch resolution. Hardware interface logic couples the computers digital and analog I/O channels to the diamond turning machine`s analog motor controllers, the laser interferometer, and other machine status and control information. It also provides front panel switches for operator override of the computer controller and implement the emergency stop sequence. The remaining two components, themore » control computer hardware and software, are discussed in detail below.« less

  15. [Hyperlexia in an adult patient with lesions in the left medial frontal lobe].

    PubMed

    Suzuki, K; Yamadori, A; Kumabe, T; Endo, K; Fujii, T; Yoshimoto, T

    2000-04-01

    A 69-year-old right-handed woman developed a transcortical motor aphasia with hyperlexia following resection of a glioma in the left medial frontal lobe. Neurological examination revealed grasp reflex in the right hand and underutilization of the right upper extremity. An MRI demonstrated lesions in the left medial frontal lobe including the supplementary motor area and the anterior part of the cingulate gyrus, which extended to the anterior part of the body of corpus callosum. Neuropsychologically she was alert and cooperative. She demonstrated transcortical motor aphasia. Her verbal output began with echolalia. Furthermore hyperlexia was observed in daily activities and during examinations. During conversation she suddenly read words written on objects around her which were totally irrelevant to the talk. When she was walking in the ward with an examiner she read words written on a trash bag that passed by and signboards which indicated a name of a room. Her conversation while walking was intermingled with reading words, which was irrelevant to the conversation. She also read time on analog clocks, which were hung on a wall in a watch store. In a naming task, she read words written on objects first and named them upon repeated question about their names. When an examiner opened a newspaper in front of her without any instructions she began reading until the examiner prohibited it. Then she began reading again when an examiner turned the page, although she remembered that she should not read it aloud. She showed mild ideomotor apraxia of a left hand. Utilization behavior, imitation behavior, hypergraphia, or compulsive use of objects was not observed throughout the course. Hyperlexic tendency is a prominent feature of this patient's language output. Hyperlexia was often reported in children with pervasive developmental disorders including autism. There are only a few reports about hyperlexia in adults and some of them were related to diffuse brain dysfunction

  16. Medium dependent dual turn on/turn off fluorescence sensing for Cu2 + ions using AMI/SDS assemblies

    NASA Astrophysics Data System (ADS)

    Gujar, Varsha B.; Ottoor, Divya

    2017-02-01

    Behavior of Amiloride (AMI) as a metal ion sensor in anionic surfactant assemblies of varying concentrations at different pH is depicted in this work. From a non-sensor fluorophore, AMI has been transformed in to a tunable fluorosensor for Cu2 + ions in various SDS concentrations. At premicellar concentration of SDS, ion-pair complex is expected to be formed between AMI and SDS due to electrostatic interactions between them. However at CMC concentrations of SDS, fluorescence intensity of AMI is greatly enhanced with red shift in emission, due to the incorporation of AMI molecule in the hydrophobic micellar interface. The behavior of metal sensing by AMI-SDS assemblies gives rise to several interesting observations. Micellation of SDS has been greatly enhanced by increasing copper ion concentrations, as these counter ions screens the charge on monomers of SDS which lead to the aggregation at premicellar concentrations only. Concentrations and pH dependent discrete trends of interactions between SDS-AMI and SDS-Cu2 + ions, have given tunable fluorescence responses (fluorescence turn on/turn off) of AMI for added Cu2 + ions. The electrostatic interaction between the metal cations and the anionic surfactants is the driving force for bringing the metal ions near to the vicinity of micelle where AMI resides. Thus, a comprehensive understanding of the mechanism related to the 'turn on-turn off' fluorescence response of AMI with respect to pH and SDS concentration for effective Cu2 + ion sensing is illustrated in this work.

  17. Reconceptualizing Autonomy: A Relational Turn in Bioethics.

    PubMed

    Jennings, Bruce

    2016-05-01

    History's judgment on the success of bioethics will not depend solely on the conceptual creativity and innovation in the field at the level of ethical and political theory, but this intellectual work is not insignificant. One important new development is what I shall refer to as the relational turn in bioethics. This development represents a renewed emphasis on the ideographic approach, which interprets the meaning of right and wrong in human actions as they are inscribed in social and cultural practices and in structures of lived meaning and interdependence; in an ideographic approach, the task of bioethics is to bring practice into theory, not the other way around. The relational turn in bioethics may profoundly affect the critical questions that the field asks and the ethical guidance it offers society, politics, and policy. The relational turn provides a way of correcting the excessive atomism of many individualistic perspectives that have been, and continue to be, influential in bioethics. Nonetheless, I would argue that most of the work reflecting the relational turn remains distinctively liberal in its respect for the ethical significance of the human individual. It moves away from individualism, but not from the value of individuality.In this review essay, I shall focus on how the relational turn has manifested itself in work on core concepts in bioethics, especially liberty and autonomy. Following a general review, I conclude with a brief consideration of two important recent books in this area: Jennifer Nedelsky's Law's Relations and Rachel Haliburton's Autonomy and the Situated Self. © 2016 The Hastings Center.

  18. [Left atrial function and left atrial appendage flow velocity in hypertrophic cardiomyopathy: comparison of patients with and without paroxysmal atrial fibrillation].

    PubMed

    Akasaka, K; Kawashima, E; Shiokoshi, T; Ishii, Y; Hasebe, N; Kikuchi, K

    1998-07-01

    The involvement of left atrial (LA) appendage flow velocity in reduced left atrial function was investigated in 24 patients with hypertrophic cardiomyopathy, who retained sinus rhythm at the examination. Patients were divided into 11 with a history of paroxysmal atrial fibrillation [PAf(+)] and 13 without such history [PAf(-)]. Transthoracic echocardiography was performed to evaluate LA fractional shortening (LA%FS) and mean velocity of circumferential LA fiber shortening (LAmVcf), as contractile functions of the left atrium at the phase of active atrial contraction. Transesophageal echocardiographic Doppler examination was performed in all patients to measure the LA appendage velocity. In all patients, significant positive correlations were observed between the LA appendage velocity and LA%FS (r = 0.50, p < 0.05) or LAmVcf (r = 0.82, p < 0.001). LAmVcf and LA appendage velocity in patients with paroxysmal fibrillation were significantly lower than in those without (0.84 +/- 0.15 vs 1.28 +/- 0.37 circ/sec, 44 +/- 12 vs 65 +/- 20 cm/sec, both p < 0.01), whereas LA diameter was greater in the former compared to the latter (45 +/- 5 vs 38 +/- 5 mm, p < 0.01). LAmVcf and LA appendage velocity were low in four patients with cerebral infarction or transient cerebral ischemic attack (LAmVcf < 1.0 circ/sec, LA appendage velocity < or = 40 cm/sec). Importantly, all these patients had a history of paroxysmal fibrillation. These results indicate that there is a close relationship between LA appendage velocity and LA contractile function in patients with hypertrophic cardiomyopathy with paroxysmal atrial fibrilation, and these patients have potential risk of cerebral infarction.

  19. Single phase four pole/six pole motor

    DOEpatents

    Kirschbaum, Herbert S.

    1984-01-01

    A single phase alternating current electric motor is provided with a main stator winding having two coil groups each including the series connection of three coils. These coil groups can be connected in series for six pole operation and in parallel for four pole operation. The coils are approximately equally spaced around the periphery of the machine but are not of equal numbers of turns. The two coil groups are identically wound and spaced 180 mechanical degrees apart. One coil of each group has more turns and a greater span than the other two coils.

  20. Variability in the implementation of the No Child Left Behind Act in Wisconsin school districts and science departments

    NASA Astrophysics Data System (ADS)

    Miller, Christopher L.

    In the United States of America, the public education system is comprised of over 14,000 school districts. Each of these unique districts is being affected by the enactment of the No Child Left Behind Act of 2001. In turn, this diverse population of school districts is determining the impact on education of this sweeping federal education policy. This study examines eight of those school districts to determine their actions related to the early phase of the implementation of one portion of NCLB, the accountability provisions prescribing standardized assessment for the determination of Adequate Yearly Progress. Specifically, this study examines what these eight Wisconsin school districts, serving from 1,000 to over 5,000 students, did with the student achievement data resulting from their state assessment, the Wisconsin Knowledge and Concepts Examinations (WKCE). A wide variety of responses were found in how school districts used the WKCE data. The eight school districts were examined to determine what features of their organizations were responsible for how they responded to the enactment of the AYP provisions, specifically how they used the WCKE data. District responses were found to be determined by district size, governance structures, personnel, and dispositions. The interactions of these characteristics were considered in light of organizational studies using conceptualizations borrowed from ecology and the theory of evolution and by studies of school districts.

  1. Simulation of turn-by-turn passage of protons through the H-minus stripping foil in booster

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gardner, C.

    Equations for transverse emittance growth due to multiple passes of circulating proton beam through the H-minus stripping foil in Booster were developed in [1]. These were based on simple principles of statistics and simple assumptions about the initial distribution of particles incident on the foil. It was assumed there that the foil dimensions and position of the incoming beam are such that all particles hit the foil on every turn around the machine. In the present note we assume only that all incoming H-minus ions from Linac hit the foil and are stripped of their electrons. The resulting protons circulatemore » indefinitely around the machine. Setups in which the foil width is reduced so that not all protons hit the foil on every turn are studied here by simulation. The aim is to determine the effectiveness of such setups in reducing the emittance growth of circulating proton beam during the injection of H-minus beam. The simulations also serve as a check of the equations developed in [1], and vice versa. The particulars of the simulation setup are given in Sections 1 through 11. Figures 1 through 12 show simulation results for the case in which all particles hit the foil on every turn. The results are in good agreement with those obtained from the equations of reference [1]. Figures 13 through 19 show simulation results for various setups in which the foil width is reduced. These results are summarized in Section 12. In all gures the horizontal axis gives the turn number. The unit of the vertical axis is micrometers ( m) in all plots of emittance.« less

  2. Safety evaluation of offset improvements for left-turn lanes

    DOT National Transportation Integrated Search

    2009-06-01

    The Federal Highway Administration (FHWA) organized 26 States to participate in the FHWA Low Cost Safety Improvements Pooled Fund Study as part of its strategic highway safety plan support effort. The purpose of the pooled fund study is to estimate t...

  3. Safety evaluation of offset improvements for left-turn lanes

    DOT National Transportation Integrated Search

    2009-06-01

    The Federal Highway Administration (FHWA) organized a pooled fund study of 26 States to evaluate low-cost safety strategies as part of its strategic highway safety effort. One of the strategies chosen to be evaluated for this study was offset improve...

  4. Dispersive Readout of Adiabatic Phases

    NASA Astrophysics Data System (ADS)

    Kohler, Sigmund

    2017-11-01

    We propose a protocol for the measurement of adiabatic phases of periodically driven quantum systems coupled to an open cavity that enables dispersive readout. It turns out that the cavity transmission exhibits peaks at frequencies determined by a resonance condition that involves the dynamical and the geometric phase. Since these phases scale differently with the driving frequency, one can determine them by fitting the peak positions to the theoretically expected behavior. For the derivation of the resonance condition and for a numerical study, we develop a Floquet theory for the dispersive readout of ac driven quantum systems. The feasibility is demonstrated for two test cases that generalize Landau-Zener-Stückelberg-Majorana interference to two-parameter driving.

  5. Left Panorama of Spirit's Landing Site

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Left Panorama of Spirit's Landing Site

    This is a version of the first 3-D stereo image from the rover's navigation camera, showing only the view from the left stereo camera onboard the Mars Exploration Rover Spirit. The left and right camera images are combined to produce a 3-D image.

  6. Rapidly progressing left atrial hemangiopericytoma.

    PubMed

    Nakamura, Tamami; Ito, Hiroshi; Sakata, Kensuke; Kobayashi, Yurio

    2015-11-01

    Cardiac hemangiopericytoma is a rare soft tissue tumor. We describe a case of hemangiopericytoma in the left atrium, which was diagnosed as myxoma preoperatively. A 70-year-old woman was admitted with heart failure. An echocardiogram showed a large myxoma-like mass in the left atrium, herniating into the left ventricle; therefore, an emergency operation was performed. Histological examination revealed a malignant hemangiopericytoma. The patient's postoperative course was uneventful, but she died due to a local recurrence 4 months after the operation. © The Author(s) 2014.

  7. The Left Atrio-Vertebral Ratio: a new simple means for assessing left atrial enlargement on Computed Tomography.

    PubMed

    Montillet, Marie; Baqué-Juston, Marie; Tasu, Jean-Pierre; Bertrand, Sandra; Berthier, Frédéric; Zarqane, Naïma; Brunner, Philippe

    2018-03-01

    The purpose of this study is to describe a new method to quickly estimate left atrial enlargement (LAE) on Computed Tomography. Left atrial (LA) volume was assessed with a 3D-threshold Hounsfield unit detection technique, including left atrial appendage and excluding pulmonary venous confluence, in 201 patients with ECG-gated 128-slice dual-source CT and indexed to body surface area. LA and vertebral axial diameter and area were measured at the bottom level of the right inferior pulmonary vein ostium. Ratio of LA diameter and surface on vertebra (LAVD and LAVA) were compared to LA volume. In accordance with the literature, a cutoff value of 78 ml/m 2 was chosen for maximal normal LA volume. 18% of LA was enlarged. The best cutoff values for LAE assessment were 2.5 for LAVD (AUC: 0.65; 95% CI: 0.58-0.73; sensitivity: 57%; specificity: 71%), and 3 for LAVA (AUC: 0.78; 95% CI: 0.72-0.84; sensitivity: 67%; specificity: 79%), with higher accuracy for LAVA (P=0.015). Inter-observer and intra-observer variability were either good or excellent for LAVD and LAVA (respective intraclass coefficients: 0.792 and 0.910; 0.912 and 0.937). A left atrium area superior to three times the vertebral area indicates LAE with high specificity. • Left atrial enlargement is a frequent condition associated with poor cardiac outcome. • Left atrial enlargement is highly time-consuming to diagnose on CT. • The left atrio-vertebral ratio quickly assesses left atrial enlargement. • A left atrial area > three times vertebral area is highly specific.

  8. A Kalman Filter Based Technique for Stator Turn-Fault Detection of the Induction Motors

    NASA Astrophysics Data System (ADS)

    Ghanbari, Teymoor; Samet, Haidar

    2017-11-01

    Monitoring of the Induction Motors (IMs) through stator current for different faults diagnosis has considerable economic and technical advantages in comparison with the other techniques in this content. Among different faults of an IM, stator and bearing faults are more probable types, which can be detected by analyzing signatures of the stator currents. One of the most reliable indicators for fault detection of IMs is lower sidebands of power frequency in the stator currents. This paper deals with a novel simple technique for detecting stator turn-fault of the IMs. Frequencies of the lower sidebands are determined using the motor specifications and their amplitudes are estimated by a Kalman Filter (KF). Instantaneous Total Harmonic Distortion (ITHD) of these harmonics is calculated. Since variation of the ITHD for the three-phase currents is considerable in case of stator turn-fault, the fault can be detected using this criterion, confidently. Different simulation results verify high performance of the proposed method. The performance of the method is also confirmed using some experiments.

  9. The ontological turn meets the certainty of death.

    PubMed

    McDonald, Maryon

    2017-08-01

    The 'ontological turn' involves some anthropological points of long standing but the approaches recently coordinated into this turn have been presented as a 'call to arms', as shaking up 'mono-realist singularities' and as inherently political. This fighting talk has no doubt made important contributions to anthropology and insights from the ontological turn can help in anthropological understandings of medical practices. However, this paper contends that this helpfulness is also limited and that a call to arms may be inappropriate. This point is made through an ethnographic understanding of medical concern about the diagnosis of death.

  10. Flip Turns with Students

    ERIC Educational Resources Information Center

    Queeney, Kate

    2014-01-01

    Kate Queeney, a professor of chemistry at Smith College, turned to a former student to receive one-on-one instruction in swimming. The student, who had been unsure and scared in chemistry class, seemed like an entirely different person when teaching the teacher. This article describes how the author learned that there is something undeniably…

  11. Effects of novel oral anticoagulants on left atrial and left atrial appendage thrombi: an appraisal.

    PubMed

    Marsico, Fabio; Cecere, Milena; Parente, Antonio; Paolillo, Stefania; de Martino, Fabiana; Dellegrottaglie, Santo; Trimarco, Bruno; Perrone Filardi, Pasquale

    2017-02-01

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and predisposes to an increased risk of thromboembolic events. Patients affected by AF exhibit an increased risk of stroke compared with those in sinus rhythm, with the most common location of thrombi in the left atrial appendage. Until 2009, warfarin and other vitamin K antagonists were the only class of oral anticoagulants available. More recently, dabigatran, rivaroxaban, apixaban, and edoxaban have been approved by regulatory authorities for prevention of stroke in patients with non-valvular AF. Few data are available about the efficacy of novel oral anticoagulants for the treatment of left atrial and left atrial appendage thrombosis. Aim of this review is to summarize available evidence regarding the effectiveness of novel oral anticoagulants on left atrial appendage thrombosis.

  12. Left hemisphere regions are critical for language in the face of early left focal brain injury.

    PubMed

    Raja Beharelle, Anjali; Dick, Anthony Steven; Josse, Goulven; Solodkin, Ana; Huttenlocher, Peter R; Levine, Susan C; Small, Steven L

    2010-06-01

    A predominant theory regarding early stroke and its effect on language development, is that early left hemisphere lesions trigger compensatory processes that allow the right hemisphere to assume dominant language functions, and this is thought to underlie the near normal language development observed after early stroke. To test this theory, we used functional magnetic resonance imaging to examine brain activity during category fluency in participants who had sustained pre- or perinatal left hemisphere stroke (n = 25) and in neurologically normal siblings (n = 27). In typically developing children, performance of a category fluency task elicits strong involvement of left frontal and lateral temporal regions and a lesser involvement of right hemisphere structures. In our cohort of atypically developing participants with early stroke, expressive and receptive language skills correlated with activity in the same left inferior frontal regions that support language processing in neurologically normal children. This was true independent of either the amount of brain injury or the extent that the injury was located in classical cortical language processing areas. Participants with bilateral activation in left and right superior temporal-inferior parietal regions had better language function than those with either predominantly left- or right-sided unilateral activation. The advantage conferred by left inferior frontal and bilateral temporal involvement demonstrated in our study supports a strong predisposition for typical neural language organization, despite an intervening injury, and argues against models suggesting that the right hemisphere fully accommodates language function following early injury.

  13. Fast turn-on osmium coated cathode

    NASA Astrophysics Data System (ADS)

    Marrian, C. R. K.; Haas, G. A.; Shih, A.

    1984-03-01

    This abstract discloses a fast turn-on refractory coated cathode comprising a porous tungsten metal matrix impregnated with barium calcium aluminate and coated with osmium. The osmium coating has a planned series of interruptions with each interruption being on the order of several microns in width to thereby expose the tungsten. These interruptions permit the barium and oxygen from the impregnant to rise to the cathode surface during activation or reactivation to form a desired near monolayer of barium and oxygen to enhance electron emission. Thus, this cathode design provides a fast turn-on characteristic even after shelf storage.

  14. Turning around Newton's Second Law

    ERIC Educational Resources Information Center

    Goff, John Eric

    2004-01-01

    Conceptual and quantitative difficulties surrounding Newton's second law often arise among introductory physics students. Simply turning around how one expresses Newton's second law may assist students in their understanding of a deceptively simple-looking equation.

  15. What Lies Ahead (left-eye)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This is the left-eye version of the 3-D cylindrical-perspective mosaic showing the view south of the martian crater dubbed 'Bonneville.' The image was taken by the navigation camera on the Mars Exploration Rover Spirit. The rover will travel toward the Columbia Hills, seen here at the upper left. The rock dubbed 'Mazatzal' and the hole the rover drilled in to it can be seen at the lower left. The rover's position is referred to as 'Site 22, Position 32.' This image was geometrically corrected to make the horizon appear flat.

  16. The Left-Handed: "Their Sinister" History.

    ERIC Educational Resources Information Center

    Costas, Elaine Fowler

    The history of left-handedness can provide teachers and parents a better understanding of left-handed children and give those children more pride in their difference. No child should be made to feel that he or she is abnormal because of using the left hand, although some specific instruction for these students is necessary in handwriting. Many…

  17. Left-handedness and language lateralization in children.

    PubMed

    Szaflarski, Jerzy P; Rajagopal, Akila; Altaye, Mekibib; Byars, Anna W; Jacola, Lisa; Schmithorst, Vincent J; Schapiro, Mark B; Plante, Elena; Holland, Scott K

    2012-01-18

    This fMRI study investigated the development of language lateralization in left- and righthanded children between 5 and 18 years of age. Twenty-seven left-handed children (17 boys, 10 girls) and 54 age- and gender-matched right-handed children were included. We used functional MRI at 3T and a verb generation task to measure hemispheric language dominance based on either frontal or temporo-parietal regions of interest (ROIs) defined for the entire group and applied on an individual basis. Based on the frontal ROI, in the left-handed group, 23 participants (85%) demonstrated left-hemispheric language lateralization, 3 (11%) demonstrated symmetric activation, and 1 (4%) demonstrated right-hemispheric lateralization. In contrast, 50 (93%) of the right-handed children showed left-hemispheric lateralization and 3 (6%) demonstrated a symmetric activation pattern, while one (2%) demonstrated a right-hemispheric lateralization. The corresponding values for the temporo-parietal ROI for the left-handed children were 18 (67%) left-dominant, 6 (22%) symmetric, 3 (11%) right-dominant and for the right-handed children 49 (91%), 4 (7%), 1 (2%), respectively. Left-hemispheric language lateralization increased with age in both groups but somewhat different lateralization trajectories were observed in girls when compared to boys. The incidence of atypical language lateralization in left-handed children in this study was similar to that reported in adults. We also found similar rates of increase in left-hemispheric language lateralization with age between groups (i.e., independent of handedness) indicating the presence of similar mechanisms for language lateralization in left- and right-handed children. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Vertical cross-spectral phases in atmospheric flow

    NASA Astrophysics Data System (ADS)

    Chougule, A.; Mann, J.; Kelly, M.

    2014-11-01

    The cross-spectral phases between velocity components at two heights are analyzed from observations at the Høvsøre test site under diabatic conditions. These phases represent the degree to which turbulence sensed at one height leads (or lags) in time the turbulence sensed at the other height. The phase angle of the cross-wind component is observed to be significantly greater than the phase for the along-wind component, which in turn is greater than the phase for the vertical component. The cross-wind and along-wind phases increase with stream-wise wavenumber and vertical separation distance, but there is no significant change in the phase angle of vertical velocity. The phase angles for all atmospheric stabilities show similar order in phasing. The phase angles from the Høvsøre observations under neutral condition are compared with a rapid distortion theory model which show similar order in phase shift.

  19. MedlinePlus.gov Turns 10!

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues MedlinePlus.gov Turns 10! Past Issues / Fall 2008 Table of ... Photo courtesy of Michael Spencer, NIH NIH's MedlinePlus.gov , the popular, consumer-friendly health Web site produced ...

  20. Double-chambered left ventricle in a cat.

    PubMed

    Smith, Paul J; Tarazi, Marwan N; Ho, Siew Yen

    2014-06-01

    Double-chambered left ventricle is a rare congenital disorder in which the left ventricular cavity is subdivided into two cavities by an anomalous septum or muscle band. We describe a case of double-chambered left ventricle, most likely caused by the presence of excessive left ventricular bands, in an asymptomatic cat. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Presence of reduced regional left ventricular function even in the absence of left ventricular wall scar tissue in the long term after repair of an anomalous left coronary artery from the pulmonary artery.

    PubMed

    Nordmeyer, Sarah; Schmitt, Boris; Nasseri, Boris; Alexi-Meskishvili, Vladimir; Kuehne, Titus; Berger, Felix; Nordmeyer, Johannes

    2018-02-01

    We sought to assess left ventricular regional function in patients with and without left ventricular wall scar tissue in the long term after repair of an anomalous origin of the left coronary artery from the pulmonary artery. A total of 20 patients aged 12.8±7.4 years were assessed 10 (0.5-17) years after the repair of an anomalous origin of the left coronary artery from the pulmonary artery; of them, 10 (50%) patients showed left ventricular wall scar tissue on current cardiac MRI. Left ventricular regional function was assessed by two-dimensional speckle-tracking echocardiography in 10 patients with scar tissue and 10 patients without scar tissue and in 10 age-matched controls. In patients with scar tissue, MRI-derived left ventricular ejection fraction was significantly reduced compared with that in patients without scar tissue (51 versus 61%, p<0.05), and echocardiography-derived longitudinal strain was significantly reduced in five of six left ventricular areas compared with that in healthy controls (average relative reduction, 46%; p<0.05). In patients without scar tissue, longitudinal strain was significantly reduced in two of six left ventricular areas (average relative reduction, 23%; p<0.05) and circumferential strain was reduced in one of six left ventricular areas (relative reduction, 56%; p<0.05) compared with that in healthy controls. Regional left ventricular function is reduced even in patients without left ventricular wall scar tissue late after successful repair of an anomalous origin of the left coronary artery from the pulmonary artery. This highlights the need for meticulous lifelong follow-up in all patients with a repaired anomalous origin of the left coronary artery from the pulmonary artery.

  2. Memorization of Sequences of Movements of the Right or the Left Hand by Right- and Left-Handers: Vector Coding.

    PubMed

    Bobrova, E V; Bogacheva, I N; Lyakhovetskii, V A; Fabinskaja, A A; Fomina, E V

    2017-01-01

    In order to test the hypothesis of hemisphere specialization for different types of information coding (the right hemisphere, for positional coding; the left one, for vector coding), we analyzed the errors of right and left-handers during a task involving the memorization of sequences of movements by the left or the right hand, which activates vector coding by changing the order of movements in memorized sequences. The task was first performed by the right or the left hand, then by the opposite hand. It was found that both'right- and left-handers use the information about the previous movements of the dominant hand, but not of the non-dom" inant one. After changing the hand, right-handers use the information about previous movements of the second hand, while left-handers do not. We compared our results with the data of previous experiments, in which positional coding was activated, and concluded that both right- and left-handers use vector coding for memorizing the sequences of their dominant hands and positional coding for memorizing the sequences of non-dominant hand. No similar patterns of errors were found between right- and left-handers after changing the hand, which suggests that in right- and left-handersthe skills are transferred in different ways depending on the type of coding.

  3. Turning Points in the Development of Classical Musicians

    ERIC Educational Resources Information Center

    Gabor, Elena

    2011-01-01

    This qualitative study investigated the vocational socialization turning points in families of classical musicians. I sampled and interviewed 20 parent-child dyads, for a total of 46 interviews. Data analysis revealed that classical musicians' experiences were marked by 11 turning points that affected their identification with the occupation:…

  4. Ventricular untwisting: a temporal link between left ventricular relaxation and suction.

    PubMed

    Notomi, Yuichi; Popovic, Zoran B; Yamada, Hirotsugu; Wallick, Don W; Martin, Maureen G; Oryszak, Stephanie J; Shiota, Takahiro; Greenberg, Neil L; Thomas, James D

    2008-01-01

    Left ventricular (LV) untwisting starts early during the isovolumic relaxation phase and proceeds throughout the early filling phase, releasing elastic energy stored by the preceding systolic deformation. Data relating untwisting, relaxation, and intraventricular pressure gradients (IVPG), which represent another manifestation of elastic recoil, are sparse. To understand the interaction between LV mechanics and inflow during early diastole, Doppler tissue images (DTI), catheter-derived pressures (apical and basal LV, left atrial, and aortic), and LV volume data were obtained at baseline, during varying pacing modes, and during dobutamine and esmolol infusion in seven closed-chest anesthetized dogs. LV torsion and torsional rate profiles were analyzed from DTI data sets (apical and basal short-axis images) with high temporal resolution (6.5 +/- 0.7 ms). Repeated-measures regression models showed moderately strong correlation of peak LV twisting with peak LV untwisting rate (r = 0.74), as well as correlations of peak LV untwisting rate with the time constant of LV pressure decay (tau, r = -0.66) and IVPG (r = 0.76, P < 0.0001 for all). In a multivariate analysis, peak LV untwisting rate was an independent predictor of tau and IVPG (P < 0.0001, for both). The start of LV untwisting coincided with the beginning of relaxation and preceded suction-aided filling resulting from elastic recoil. Untwisting rate may be a useful marker of diastolic function or even serve as a therapeutic target for improving diastolic function.

  5. Speech dynamics are coded in the left motor cortex in fluent speakers but not in adults who stutter

    PubMed Central

    Hoang, T. N. Linh; Neef, Andreas; Paulus, Walter; Sommer, Martin

    2015-01-01

    The precise excitability regulation of neuronal circuits in the primary motor cortex is central to the successful and fluent production of speech. Our question was whether the involuntary execution of undesirable movements, e.g. stuttering, is linked to an insufficient excitability tuning of neural populations in the orofacial region of the primary motor cortex. We determined the speech-related time course of excitability modulation in the left and right primary motor tongue representation. Thirteen fluent speakers (four females, nine males; aged 23–44) and 13 adults who stutter (four females, nine males, aged 21–55) were asked to build verbs with the verbal prefix ‘auf’. Single-pulse transcranial magnetic stimulation was applied over the primary motor cortex during the transition phase between a fixed labiodental articulatory configuration and immediately following articulatory configurations, at different latencies after transition onset. Bilateral electromyography was recorded from self-adhesive electrodes placed on the surface of the tongue. Off-line, we extracted the motor evoked potential amplitudes and normalized these amplitudes to the individual baseline excitability during the fixed configuration. Fluent speakers demonstrated a prominent left hemisphere increase of motor cortex excitability in the transition phase (P = 0.009). In contrast, the excitability of the right primary motor tongue representation was unchanged. Interestingly, adults afflicted with stuttering revealed a lack of left-hemisphere facilitation. Moreover, the magnitude of facilitation was negatively correlated with stuttering frequency. Although orofacial midline muscles are bilaterally innervated from corticobulbar projections of both hemispheres, our results indicate that speech motor plans are controlled primarily in the left primary speech motor cortex. This speech motor planning-related asymmetry towards the left orofacial motor cortex is missing in stuttering. Moreover, a

  6. Minimum-fuel turning climbout and descent guidance of transport jets

    NASA Technical Reports Server (NTRS)

    Neuman, F.; Kreindler, E.

    1983-01-01

    The complete flightpath optimization problem for minimum fuel consumption from takeoff to landing including the initial and final turns from and to the runway heading is solved. However, only the initial and final segments which contain the turns are treated, since the straight-line climbout, cruise, and descent problems have already been solved. The paths are derived by generating fields of extremals, using the necessary conditions of optimal control together with singular arcs and state constraints. Results show that the speed profiles for straight flight and turning flight are essentially identical except for the final horizontal accelerating or decelerating turns. The optimal turns require no abrupt maneuvers, and an approximation of the optimal turns could be easily integrated with present straight-line climb-cruise-descent fuel-optimization algorithms. Climbout at the optimal IAS rather than the 250-knot terminal-area speed limit would save 36 lb of fuel for the 727-100 aircraft.

  7. Patient-specific analysis of blood stasis in the left atrium

    NASA Astrophysics Data System (ADS)

    Flores, Oscar; Gonzalo, Alejandro; Garcia-Villalba, Manuel; Rossini, Lorenzo; Hsiao, Albert; McVeigh, Elliot; Kahn, Andrew M.; Del Alamo, Juan C.

    2016-11-01

    Atrial fibrillation (AF) is a common arrhythmia in which the left atrium (LA) beats rapidly and irregularly. Patients with AF are at increased risk of thromboembolic events (TE), particularly stroke. Anticoagulant therapy can reduce the risk of TE in AF, but it can also increase the risks of adverse events such as internal bleeding. The current lack of tools to predict each patient's risk of LA thrombogenesis makes it difficult to decide whether to anticoagulate patients with AF. The aim of this work is to evaluate blood stasis in patient-specific models of the LA, because stasis is a known thrombogenesis risk factor. To achieve our aim, we performed direct numerical simulations of left atrial flow using an immersed boundary solver developed at the UC3M, coupled to a 0D model for the pulmonary circulation. The LA geometry is obtained from time-resolved CT scans and the parameters of the 0D model are found by fitting pulmonary vein flow data obtained by 4D phase contrast MRI. Blood stasis is evaluated from the flow data by computing blood residence time together with other kinematic indices of the velocity field (e.g. strain and kinetic energy). We focus on the flow in the left atrial appendage, including a sensitivity analysis of the effect of the parameters of the 0D model. Funded by the Spanish MECD, the Clinical and Translational Research Institute at UCSD and the American Heart Association.

  8. Investigation on quench initiation and propagation characteristics of GdBCO coil co-wound with a stainless steel tape as turn-to-turn metallic insulation.

    PubMed

    Kim, Y G; Song, J B; Choi, Y H; Yang, D G; Kim, S G; Lee, H G

    2016-11-01

    This paper investigates the quench initiation and propagation characteristics of a metallic insulation (MI) coil by conducting thermal quench tests for a GdBCO single-pancake coil co-wound with a stainless steel tape as the turn-to-turn MI. The test results confirmed that the MI coil exhibited superior thermal and electrical stabilities compared to the conventional coils co-wound with organic insulation material because the operating current could flow along the radial direction due to the existence of a turn-to-turn contact when a local hot spot was generated. The results of the quench test at a heater current (I h ) of 12, 13, and 14 A indicate that the MI coil possesses a self-protecting characteristic resulting from the "current bypass" through the turn-to-turn contact. However, the test coil was not self-protecting at I h = 15 A because the Joule heat energy generated by the radial current flow was not completely dissipated due to the characteristic resistance of the metallic insulation tape and the non-superconducting materials, including the substrate, stabilizer, and buffer layers within the high-temperature superconductor (HTS) tape. Even though the MI coil possesses superior thermal and electrical stability relative to those of conventional HTS coils co-wound with an organic material as turn-to-turn insulation, it is essential to consider the critical role of the Joule heat energy resulting from the operating current and stored magnetic energy as well as the characteristic resistances in order to further develop self-protective 2G HTS magnets.

  9. Preoperative left ventricular ejection fraction and left atrium reverse remodeling after mitral regurgitation surgery.

    PubMed

    Machado, Lucia R; Meneghelo, Zilda M; Le Bihan, David C S; Barretto, Rodrigo B M; Carvalho, Antonio C; Moises, Valdir A

    2014-11-06

    Left atrium enlargement has been associated with cardiac events in patients with mitral regurgitation (MR). Left atrium reverse remodeling (LARR) occur after surgical correction of MR, but the preoperative predictors of this phenomenon are not well known. It is therefore important to identify preoperative predictors for postoperative LARR. We enrolled 62 patients with chronic severe MR (prolapse or flail leaflet) who underwent successful mitral valve surgery (repair or replacement); all with pre- and postoperative echocardiography. LARR was defined as a reduction in left atrium volume index (LAVI) of ≥ 25%. Stepwise multiple regression analysis was used to identify independent predictors of LARR. LARR occurred in 46 patients (74.2%), with the mean LAVI decreasing from 85.5 mL/m2 to 49.7 mL/m2 (p <0.001). These patients had a smaller preoperative left ventricular systolic volume (p =0.022) and a higher left ventricular ejection fraction (LVEF) (p =0.034). LVEF was identified as the only preoperative variable significantly associated with LARR (odds ratio, 1.086; 95% confidence interval, 1.002-1.178). A LVEF cutoff value of 63.5% identified patients with LARR of ≥ 25% with a sensitivity of 71.7% and a specificity of 56.3%. LARR occurs frequently after mitral valve surgery and is associated with preoperative LVEF higher than 63.5%.

  10. Comparison of gating methods for the real-time analysis of left ventricular function in nonimaging blood pool studies.

    PubMed

    Beard, B B; Stewart, J R; Shiavi, R G; Lorenz, C H

    1995-01-01

    Gating methods developed for electrocardiographic-triggered radionuclide ventriculography are being used with nonimaging detectors. These methods have not been compared on the basis of their real-time performance or suitability for determination of load-independent indexes of left ventricular function. This work evaluated the relative merits of different gating methods for nonimaging radionuclude ventriculographic studies, with particular emphasis on their suitability for real-time measurements and the determination of pressure-volume loops. A computer model was used to investigate the relative accuracy of forward gating, backward gating, and phase-mode gating. The durations of simulated left ventricular time-activity curves were randomly varied. Three acquisition parameters were considered: frame rate, acceptance window, and sample size. Twenty-five studies were performed for each combination of acquisition parameters. Hemodynamic and shape parameters from each study were compared with reference parameters derived directly from the random time-activity curves. Backward gating produced the largest errors under all conditions. For both forward gating and phase-mode gating, ejection fraction was underestimated and time to end systole and normalized peak ejection rate were overestimated. For the hemodynamic parameters, forward gating was marginally superior to phase-mode gating. The mean difference in errors between forward and phase-mode gating was 1.47% (SD 2.78%). However, for root mean square shape error, forward gating was several times worse in every case and seven times worse than phase-mode gating on average. Both forward and phase-mode gating are suitable for real-time hemodynamic measurements by nonimaging techniques. The small statistical difference between the methods is not clinically significant. The true shape of the time-activity curve is maintained most accurately by phase-mode gating.

  11. Understanding Learning: Assessment in the Turning Points School

    ERIC Educational Resources Information Center

    Center for Collaborative Education, 2005

    2005-01-01

    Turning Points helps middle schools create challenging, caring, and equitable learning communities that meet the needs of young adolescents as they reach the "turning point" between childhood and adulthood. Based on more than a decade of research and experience, this comprehensive school reform model focuses on improving student learning through…

  12. Case Study Using Ultrasound to Treat /[turned r]/

    ERIC Educational Resources Information Center

    Modha, Geetanjalee; Bernhardt, B. May; Church, Robyn; Bacsfalvi, Penelope

    2008-01-01

    Background: Ultrasound has shown promise as visual feedback in remediation of /[turned r]/.Aims: To compare treatment for [turned r] with and without ultrasound.Methods & Procedures: A Canadian English-speaking adolescent participated in a case study with a no treatment baseline, alternating treatment blocks with and without ultrasound and a…

  13. Four quadrant control circuit for a brushless three-phase dc motor

    NASA Technical Reports Server (NTRS)

    Nola, Frank J. (Inventor)

    1987-01-01

    A control circuit is provided for a brushless three-phase dc motor which affords four quadrant control from a single command. The control circuit probes acceleration of the motor in both clockwise and counterclockwise directions and braking and generation in both clockwise and counterclockwise directions. In addition to turning on individual transistors of the transistor pairs connected to the phase windings of the motor for 120 deg periods while the other transistor of that pair is off, the control circuit also provides, in a future mode of operation, turning the two transistors of each pair on and off alternately at a phase modulation frequency during such a 120 deg period. A feedback signal is derived which is proportional to the motor current and which has a polarity consistent with the command signal, such that negative feedback results.

  14. Probabilistic physical characteristics of phase transitions at highway bottlenecks: incommensurability of three-phase and two-phase traffic-flow theories.

    PubMed

    Kerner, Boris S; Klenov, Sergey L; Schreckenberg, Michael

    2014-05-01

    Physical features of induced phase transitions in a metastable free flow at an on-ramp bottleneck in three-phase and two-phase cellular automaton (CA) traffic-flow models have been revealed. It turns out that at given flow rates at the bottleneck, to induce a moving jam (F → J transition) in the metastable free flow through the application of a time-limited on-ramp inflow impulse, in both two-phase and three-phase CA models the same critical amplitude of the impulse is required. If a smaller impulse than this critical one is applied, neither F → J transition nor other phase transitions can occur in the two-phase CA model. We have found that in contrast with the two-phase CA model, in the three-phase CA model, if the same smaller impulse is applied, then a phase transition from free flow to synchronized flow (F → S transition) can be induced at the bottleneck. This explains why rather than the F → J transition, in the three-phase theory traffic breakdown at a highway bottleneck is governed by an F → S transition, as observed in real measured traffic data. None of two-phase traffic-flow theories incorporates an F → S transition in a metastable free flow at the bottleneck that is the main feature of the three-phase theory. On the one hand, this shows the incommensurability of three-phase and two-phase traffic-flow theories. On the other hand, this clarifies why none of the two-phase traffic-flow theories can explain the set of fundamental empirical features of traffic breakdown at highway bottlenecks.

  15. A galloping quadruped model using left-right asymmetry in touchdown angles.

    PubMed

    Tanase, Masayasu; Ambe, Yuichi; Aoi, Shinya; Matsuno, Fumitoshi

    2015-09-18

    Among quadrupedal gaits, the galloping gait has specific characteristics in terms of locomotor behavior. In particular, it shows a left-right asymmetry in gait parameters such as touchdown angle and the relative phase of limb movements. In addition, asymmetric gait parameters show a characteristic dependence on locomotion speed. There are two types of galloping gaits in quadruped animals: the transverse gallop, often observed in horses; and the rotary gallop, often observed in dogs and cheetahs. These two gaits have different footfall sequences. Although these specific characteristics in quadrupedal galloping gaits have been observed and described in detail, the underlying mechanisms remain unclear. In this paper, we use a simple physical model with a rigid body and four massless springs and incorporate the left-right asymmetry of touchdown angles. Our simulation results show that our model produces stable galloping gaits for certain combinations of model parameters and explains these specific characteristics observed in the quadrupedal galloping gait. The results are then evaluated in comparison with the measured data of quadruped animals and the gait mechanisms are clarified from the viewpoint of dynamics, such as the roles of the left-right touchdown angle difference in the generation of galloping gaits and energy transfer during one gait cycle to produce two different galloping gaits. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. History of Education in Canada: Historiographic "Turns" and Widening Horizons

    ERIC Educational Resources Information Center

    Bruno-Jofré, Rosa

    2014-01-01

    This paper explores major historiographic "turns" in history of education with a focus, although not exclusively, on English-speaking Canada. It addresses the transformative intellectual impact of the turn toward social history on the history of education, the impact of cultural history and the linguistic turn, the reception of Michel…

  17. Complex blood flow patterns in an idealized left ventricle: A numerical study

    NASA Astrophysics Data System (ADS)

    Tagliabue, Anna; Dedè, Luca; Quarteroni, Alfio

    2017-09-01

    In this paper, we study the blood flow dynamics in a three-dimensional (3D) idealized left ventricle of the human heart whose deformation is driven by muscle contraction and relaxation in coordination with the action of the mitral and aortic valves. We propose a simplified but realistic mathematical treatment of the valves function based on mixed time-varying boundary conditions (BCs) for the Navier-Stokes equations modeling the flow. These switchings in time BCs, from natural to essential and vice versa, model either the open or the closed configurations of the valves. At the numerical level, these BCs are enforced by means of the extended Nitsche's method (Tagliabue et al., Int. J. Numer. Methods Fluids, 2017). Numerical results for the 3D idealized left ventricle obtained by means of Isogeometric Analysis are presented, discussed in terms of both instantaneous and phase-averaged quantities of interest and validated against those available in the literature, both experimental and computational. The complex blood flow patterns are analysed to describe the characteristic fluid properties, to show the transitional nature of the flow, and to highlight its main features inside the left ventricle. The sensitivity of the intraventricular flow patterns to the mitral valve properties is also investigated.

  18. Aberrant left subclavian artery occlusion in right-sided aortic artery associated with left cerebral infarction: A case report.

    PubMed

    Tempaku, Akira; Kuroiwa, Terumasa; Nishio, Akimasa

    2018-06-01

    Purpose Right-sided aortic arch is a rare vessel anomaly with an incidence of 0.1% worldwide. Supra-aortic branches form a mirror image of the left-sided aortic arch or an aberrant left subclavian artery associated with Kommerell diverticulum. Most patients are diagnosed by a difference in blood pressure in each upper extremity or by the presence of left subclavian steal syndrome in their younger age. The diagnosis of onset of ischemic stroke in middle age is rare. Methods We present the case of a female patient who presented with an ischemic stroke in the left posterior circulation area. She had no history of congenital heart malformation. We performed head magnetic resonance imaging, cerebral angiography, and enhanced computed tomography of the aortic arch and major branches. Results The patient had a right-sided aortic arch and an aberrant left subclavian artery. The left subclavian artery was occluded at the proximal portion with a fibrous string. Collateral flow in the anterior cervical subcutaneous area supported left limb perfusion. Conclusion An atheromatous change reduced shunt flow via collateral networks at the anterior cervical region. Congenital subclavian steal supported the ischemic stroke.

  19. Human Rights Education and the Post Secular Turn

    ERIC Educational Resources Information Center

    Bowie, Bob

    2012-01-01

    This article questions whether human rights education (HRE) scholarship is responding adequately to the post secular turn in thinking about the place and nature of religion in society. Here the post secular turn is used to describe the discrediting of secularisation theory, the recognition of religion as an enduring and pervasive global cultural…

  20. Left ventricular to left atrial communication secondary to a paraaortic abscess: color flow Doppler documentation.

    PubMed

    Fisher, E A; Estioko, M R; Stern, E H; Goldman, M E

    1987-07-01

    Aortic root abscess occurs frequently in aortic prosthetic valve infective endocarditis. The present echocardiographic report documents a ruptured abscess that led to a direct communication between the left ventricular outflow tract and the left atrium confirmed by real-time (color flow) Doppler imaging.

  1. Postoperative pulmonary hypertensive crisis caused by inverted left atrial appendage after cardiopulmonary bypass surgery for congenital heart disease in a neonate.

    PubMed

    Zhao, Qifeng; Hu, Xingti

    2013-09-01

    Postoperative pulmonary hypertensive crisis (PHC) caused by an inverted left atrial appendage (ILAA) is a rare complication following cardiac surgery. We present a case of 23 day-old male infant who developed postoperative PHC attacks after undergoing cardiopulmonary bypass (CPB) surgery for repair of the coactation of aorta. A hyperechogenic left atrial mass was detected via bedside transthoracic echocardiography (TTE), which was identified as an ILAA and corrected following repeat surgery. In this case, both the negative pressure in vent catheter and the long left atrial appendage (LAA) with a narrow base led to an irreversible ILAA. As in this neonate, ILAA had significant influence on the left atrial volume and caused PHC since the ILAA was located on the mitral valve orifice and interfered with the blood flow through the valve. Therefore, we recommend that the vent catheter should be turned off before removing to avoid this potential complication. Additionally, LAA should be carefully inspected after CPB surgery, and intra-operative and post-operative transoesophageal echocardiography (TEE) should be performed to detect ILAA intraoperatively so as to avoid the reoperation. When an ILAA is diagnosed postoperatively, whether conservative treatment or surgery will depend on the balance of benefit and risk for a particular patient. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  2. Turn Openings in Academic Talk: Where Goals and Roles Intersect

    ERIC Educational Resources Information Center

    Evison, Jane

    2013-01-01

    This study uses Corpus Linguistic (CL) techniques to explore multiple turn openings in conjunction with comparative measures of turn-initial priming (the proportion of occurrences of a form that are turn-initial). Using a benchmark corpus of casual conversation as a point of comparison, six frequent items which have a particularly strong affinity…

  3. Compensations for increased rotational inertia during human cutting turns.

    PubMed

    Qiao, Mu; Brown, Brian; Jindrich, Devin L

    2014-02-01

    Locomotion in a complex environment is often not steady state, but unsteady locomotion (stability and maneuverability) is not well understood. We investigated the strategies used by humans to perform sidestep cutting turns when running. Previous studies have argued that because humans have small yaw rotational moments of inertia relative to body mass, deceleratory forces in the initial velocity direction that occur during the turning step, or 'braking' forces, could function to prevent body over-rotation during turns. We tested this hypothesis by increasing body rotational inertia and testing whether braking forces during stance decreased. We recorded ground reaction force and body kinematics from seven participants performing 45 deg sidestep cutting turns and straight running at five levels of body rotational inertia, with increases up to fourfold. Contrary to our prediction, braking forces remained consistent at different rotational inertias, facilitated by anticipatory changes to body rotational speed. Increasing inertia revealed that the opposing effects of several turning parameters, including rotation due to symmetrical anterior-posterior forces, result in a system that can compensate for fourfold changes in rotational inertia with less than 50% changes to rotational velocity. These results suggest that in submaximal effort turning, legged systems may be robust to changes in morphological parameters, and that compensations can involve relatively minor adjustments between steps to change initial stance conditions.

  4. Compensations for increased rotational inertia during human cutting turns

    PubMed Central

    Qiao, Mu; Brown, Brian; Jindrich, Devin L.

    2014-01-01

    Locomotion in a complex environment is often not steady state, but unsteady locomotion (stability and maneuverability) is not well understood. We investigated the strategies used by humans to perform sidestep cutting turns when running. Previous studies have argued that because humans have small yaw rotational moments of inertia relative to body mass, deceleratory forces in the initial velocity direction that occur during the turning step, or ‘braking’ forces, could function to prevent body over-rotation during turns. We tested this hypothesis by increasing body rotational inertia and testing whether braking forces during stance decreased. We recorded ground reaction force and body kinematics from seven participants performing 45 deg sidestep cutting turns and straight running at five levels of body rotational inertia, with increases up to fourfold. Contrary to our prediction, braking forces remained consistent at different rotational inertias, facilitated by anticipatory changes to body rotational speed. Increasing inertia revealed that the opposing effects of several turning parameters, including rotation due to symmetrical anterior–posterior forces, result in a system that can compensate for fourfold changes in rotational inertia with less than 50% changes to rotational velocity. These results suggest that in submaximal effort turning, legged systems may be robust to changes in morphological parameters, and that compensations can involve relatively minor adjustments between steps to change initial stance conditions. PMID:24115061

  5. U-Turns at signalized intersections.

    DOT National Transportation Integrated Search

    2004-06-01

    The objectives of the study were to examine the safety consequences from the installation of U-turns at signalized intersections in Kentucky and to develop a set of guidelines for using this alternative in the future. The literature review indicated ...

  6. 32 CFR 935.135 - Turns.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... center of the road, except that on multi-lane roads of one-way traffic flow he may make the turn only... motion from a stopped position, or change from or merge into a lane of traffic, until he can safely make...

  7. 32 CFR 935.135 - Turns.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... center of the road, except that on multi-lane roads of one-way traffic flow he may make the turn only... motion from a stopped position, or change from or merge into a lane of traffic, until he can safely make...

  8. 32 CFR 935.135 - Turns.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... center of the road, except that on multi-lane roads of one-way traffic flow he may make the turn only... motion from a stopped position, or change from or merge into a lane of traffic, until he can safely make...

  9. 32 CFR 935.135 - Turns.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... center of the road, except that on multi-lane roads of one-way traffic flow he may make the turn only... motion from a stopped position, or change from or merge into a lane of traffic, until he can safely make...

  10. 32 CFR 935.135 - Turns.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... center of the road, except that on multi-lane roads of one-way traffic flow he may make the turn only... motion from a stopped position, or change from or merge into a lane of traffic, until he can safely make...

  11. Persistent left superior vena cava

    PubMed Central

    Tyrak, Kamil W; Hołda, Mateusz K; Koziej, Mateusz; Piątek, Katarzyna; Klimek-Piotrowska, Wiesława

    2017-01-01

    Summary Persistent left superior vena cava (PLSVC) is the most common congenital malformation of thoracic venous return and is present in 0.3 to 0.5% of individuals in the general population. This heart specimen was dissected from a 35-yearold male cadaver whose cause of death was determined as non-cardiac. The heart was examined and we found a PLSVC draining into the coronary sinus. The right superior vena cava was present with a small-diameter ostium. An anomalous pulmonary vein pattern was observed; there was a common trunk to the left superior and left inferior pulmonary veins (diameter 17.8 mm) and an additional middle right pulmonary vein (diameter 2.7 mm) with two classic right pulmonary veins. The PLSVC draining into the coronary sinus had led to its enlargement, which could have altered the cardiac haemodynamics by significantly reducing the size of the left atrium and impeding its outflow via the mitral valve. PMID:28759082

  12. Alternative Fuels Data Center: DeKalb County Turns Trash to Gas

    Science.gov Websites

    DeKalb County Turns Trash to Gas to someone by E-mail Share Alternative Fuels Data Center: DeKalb County Turns Trash to Gas on Facebook Tweet about Alternative Fuels Data Center: DeKalb County Turns Trash to Gas on Twitter Bookmark Alternative Fuels Data Center: DeKalb County Turns Trash to Gas on

  13. Single phase four pole/six pole motor

    DOEpatents

    Kirschbaum, H.S.

    1984-10-09

    A single phase alternating current electric motor is provided with a main stator winding having two coil groups each including the series connection of three coils. These coil groups can be connected in series for six pole operation and in parallel for four pole operation. The coils are approximately equally spaced around the periphery of the machine but are not of equal numbers of turns. The two coil groups are identically wound and spaced 180 mechanical degrees apart. One coil of each group has more turns and a greater span than the other two coils. 10 figs.

  14. NEHRP turns 40

    USGS Publications Warehouse

    Leith, William S.

    2017-01-01

    This year, the National Earthquake Hazards Reduction Program (NEHRP) turns 40, four decades since the Earthquake Hazards Reduction Act of 1977 was enacted establishing the Program, spurring numerous federal, state, and community actions to reduce earthquake losses in the U.S.A. and its territories and setting a standard for earthquake loss‐reduction projects internationally. Four agencies are partners in NEHRP: the Federal Emergency Management Agency (FEMA), the National Institute of Standards and Technology (NIST, the lead agency), the National Science Foundation (NSF), and the U.S. Geological Survey (USGS).

  15. Characterization of jellyfish turning using 3D-PTV

    NASA Astrophysics Data System (ADS)

    Xu, Nicole; Dabiri, John

    2017-11-01

    Aurelia aurita are oblate, radially symmetric jellyfish that consist of a gelatinous bell and subumbrellar muscle ring, which contracts to provide motive force. Swimming is typically modeled as a purely vertical motion; however, asymmetric activations of swim pacemakers (sensory organs that innervate the muscle at eight locations around the bell margin) result in turning and more complicated swim behaviors. More recent studies have examined flow fields around turning jellyfish, but the input/output relationship between locomotive controls and swim trajectories is unclear. To address this, bell kinematics for both straight swimming and turning are obtained using 3D particle tracking velocimetry (3D-PTV) by injecting biocompatible elastomer tags into the bell, illuminating the tank with ultraviolet light, and tracking the resulting fluorescent particles in a multi-camera setup. By understanding these kinematics in both natural and externally controlled free-swimming animals, we can connect neuromuscular control mechanisms to existing flow measurements of jellyfish turning for applications in designing more energy efficient biohybrid robots and underwater vehicles. NSF GRFP.

  16. The influence of rear turn-signal characteristics on crash risk.

    PubMed

    Sullivan, John M; Flannagan, Michael J

    2012-02-01

    The relationship between the relative risk of a rear-end collision during a turn, merge, or lane change maneuver and the characteristics of the rear turn-signal configuration was examined using crash data from seven states in the United States. Rear turn-signal characteristics-including color, optics, separation, and light source-were identified for 55 vehicle models and used in a logistic regression analysis to model the odds of a rear-end collision. Additional variables including driver demographics (gender, age), vehicle age, and light condition were also modeled. Risk was assessed using a contrast group of striking vehicles in similar collisions. The results suggest that the odds of being the struck vehicle were 3% to 28% lower among vehicles equipped with amber versus red turn signals. Although the analysis suggests that there may be a safety benefit associated with amber rear turn signals, it is unclear whether turn-signal color alone is responsible. The results suggest that aspects of a vehicle's rear signal characteristics may influence crash risk. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. High-Intensity Interval Training for Severe Left Ventricular Dysfunction Treated with Left Ventricular Assist Device.

    PubMed

    Ugata, Yusuke; Wada, Hiroshi; Sakakura, Kenichi; Ibe, Tatsuro; Ito, Miyuki; Ikeda, Nahoko; Fujita, Hideo; Momomura, Shin-Ichi

    2018-01-27

    Aerobic training based on anaerobic threshold (AT) is well-known to improve cardiac function, exercise capacity, and long-term outcomes of patients with heart failure. Recent reports suggested that high-intensity interval training (HIIT) for patients with cardiovascular disease may improve cardiopulmonary exercise capacity. We present a 61-year-old male patient of severe left ventricular dysfunction with left ventricular assisted device (LVAD). Following HIIT for 8 weeks, exercise capacity and muscle strength have improved without worsening left ventricular function. Our case showed the possibility that HIIT was feasible and effective even in patients with LVAD.

  18. Effect of Pedestrians on the Saturation Flow Rate of Right Turn Movements at Signalized Intersection - Case Study from Rasht City

    NASA Astrophysics Data System (ADS)

    Roshani, Mostafa; Bargegol, Iraj

    2017-10-01

    Saturation flow rate is one of the important items in the analysis of the capacity of signalized intersections that are affected by some factors. Pedestrian crossing on signalized intersection is one of the factors which influence the vehicles flow. In addition, the released researches determined that the greatest impact of pedestrian on the saturation flow occurred in the Conflict zone where the highest chance of the encounter of pedestrians and vehicles has in turning movements. The purpose of this paper is to estimate the saturation flow rate considering the effect of a pedestrian on right turn movements of the signalized intersections in Rasht city. For this goal, 6 signalized intersections with 90 cycles of reviews were selected for the estimation of saturation flow rate by the microscopic method and also 3 right turn lanes containing radius differences with 70 cycles of reviews were collected for the investigation of the pedestrians’ effects. Each phase of right turn lanes cycle was divided in the pieces of 10-second period which was totally 476 sample volumes of considered pedestrians and vehicles at that period. Only 101 samples of those were ranged as saturated conditions. Finally, using different regression models, the best relationship between pedestrian’s volume and right turning vehicles flow parameters was evaluated. The results indicate that there is a primarily linear relationship between pedestrian volume and right turning vehicles flow with R2=0.6261. According to this regression model with the increase in pedestrians, saturation flow rate will be reduced. In addition, by comparing the adjustment factor obtained in the present study and other studies, it was found that the effect of pedestrians on the right-turn movements in Rasht city is less than the rest of the world.

  19. Phase synchronization of oscillations in cardiovascular and respiratory systems in humans

    NASA Astrophysics Data System (ADS)

    Tankanag, Arina V.; Grinevich, Andrey A.; Tikhonova, Irina V.; Chaplygina, Alina V.; Chemeris, Nikolay K.

    2017-04-01

    Phase synchronization between blood flow oscillations of left and right forearm skin sites, heart rate variability (HRV) and breath rate were studied from healthy volunteers at rest. The degree of synchronization between the phases of the analyzed signals was estimated from the value of the wavelet phase coherence. High medians of values of phase wavelet coherence function were obtained for the endothelial, neurogenic, myogenic and cardiac intervals. Significant phase synchronization were demonstrated between HRV and skin blood flow oscillations in both left and right forearms in a wide frequency range from 0.04 to 0.4 Hz. Six participants exhibited low phase synchronization (< 0.5) between the breath rate and HRV, while nine participants had high phase synchronization (> 0.5). This distribution was not affected by the sex or sympathovagal status of volunteers. Participants with low phase synchronization between breath rate and HRV featured low phase synchronization (< 0.5) between breath rate and blood flow oscillations in both forearms. Contrariwise, in subjects with high phase synchronization between respiratory rhythm and HRV both low and high phase synchronization between breath rate and blood flow oscillations in both forearms was observed. The results obtained allow us to suggest that the organism possesses a mechanism mediating the synchronization of blood flow oscillations in the skin microvasculature with all other periodical processes across the cardiovascular system, in particular, with HRV and breath rate over a wide frequency range.

  20. Implantation of a HeartMate II left ventricular assist device via left thoracotomy.

    PubMed

    Cho, Yang Hyun; Deo, Salil V; Schirger, John A; Pereira, Naveen L; Stulak, John M; Park, Soon J

    2012-11-01

    Left thoracotomy was used as an approach for the implantation of pulsatile ventricular assist devices. Avoiding the standard approach of median sternotomy is attractive in patients undergoing complicated redo cardiac surgery, especially with prior mediastinal radiation. We report a case of the use of left thoracotomy for the implantation of the HeartMate II axial-flow pump. Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  1. Coexistence of congenital left ventricular aneurysm and prominent left ventricular trabeculation in a patient with LDB3 mutation: a case report.

    PubMed

    Shan, Shengshuai; He, Xiaoxiao; He, Lin; Wang, Min; Liu, Chengyun

    2017-08-19

    The coexistence of congenital left ventricular aneurysm and abnormal cardiac trabeculation with gene mutation has not been reported previously. Here, we report a case of coexisting congenital left ventricular aneurysm and prominent left ventricular trabeculation in a patient with LIM domain binding 3 gene mutation. A 30-year-old Asian man showed paroxysmal sinus tachycardia and Q waves in an electrocardiogram health check. There were no specific findings in physical examinations and serological tests. A coronary-computed tomography angiography check showed normal coronary artery and no coronary stenosis. Both left ventricle contrast echocardiography and cardiac magnetic resonance showed rare patterns of a combination of an apical aneurysm-like out-pouching structure with a wide connection to the left ventricle and prominent left ventricular trabecular meshwork. High-throughput sequencing examinations showed a novel mutation in the LDB3 gene (c.C793>T; p.Arg265Cys). Our finding indicates that the phenotypic expression of two heart conditions, congenital left ventricular aneurysm and prominent left ventricular trabeculation, although rare, can occur simultaneously with LDB3 gene mutation. Congenital left ventricular aneurysm and prominent left ventricular trabeculation may share the same genetic background.

  2. Phase response of the Arabidopsis thaliana circadian clock to light pulses of different wavelengths.

    PubMed

    Ohara, Takayuki; Fukuda, Hirokazu; Tokuda, Isao T

    2015-04-01

    Light is known as one of the most powerful environmental time cues for the circadian system. The quality of light is characterized by its intensity and wavelength. We examined how the phase response of Arabidopsis thaliana depends on the wavelength of the stimulus light and the type of light perturbation. Using transgenic A. thaliana expressing a luciferase gene, we monitored the rhythm of the bioluminescence signal. We stimulated the plants under constant red light using 3 light perturbation treatments: (1) increasing the red light intensity, (2) turning on a blue light while turning off the red light, and (3) turning on a blue light while keeping the red light on. To examine the phase response properties, we generated a phase transition curve (PTC), which plots the phase after the perturbation as a function of the phase before the perturbation. To evaluate the effect of the 3 light perturbation treatments, we simulated PTCs using a mathematical model of the plant circadian clock and fitted the simulated PTCs to the experimentally measured PTCs. Among the 3 treatments, perturbation (3) provided the strongest stimulus. The results indicate that the color of the stimulus light and the type of pulse administration affect the phase response in a complex manner. Moreover, the results suggest the involvement of interaction between red and blue light signaling pathways in resetting of the plant circadian clock. © 2015 The Author(s).

  3. Absence of rotational activity detected using 2-dimensional phase mapping in the corresponding 3-dimensional phase maps in human persistent atrial fibrillation.

    PubMed

    Pathik, Bhupesh; Kalman, Jonathan M; Walters, Tomos; Kuklik, Pawel; Zhao, Jichao; Madry, Andrew; Sanders, Prashanthan; Kistler, Peter M; Lee, Geoffrey

    2018-02-01

    Current phase mapping systems for atrial fibrillation create 2-dimensional (2D) maps. This process may affect the accurate detection of rotors. We developed a 3-dimensional (3D) phase mapping technique that uses the 3D locations of basket electrodes to project phase onto patient-specific left atrial 3D surface anatomy. We sought to determine whether rotors detected in 2D phase maps were present at the corresponding time segments and anatomical locations in 3D phase maps. One-minute left atrial atrial fibrillation recordings were obtained in 14 patients using the basket catheter and analyzed off-line. Using the same phase values, 2D and 3D phase maps were created. Analysis involved determining the dominant propagation patterns in 2D phase maps and evaluating the presence of rotors detected in 2D phase maps in the corresponding 3D phase maps. Using 2D phase mapping, the dominant propagation pattern was single wavefront (36.6%) followed by focal activation (34.0%), disorganized activity (23.7%), rotors (3.3%), and multiple wavefronts (2.4%). Ten transient rotors were observed in 9 of 14 patients (64%). The mean rotor duration was 1.1 ± 0.7 seconds. None of the 10 rotors observed in 2D phase maps were seen at the corresponding time segments and anatomical locations in 3D phase maps; 4 of 10 corresponded with single wavefronts in 3D phase maps, 2 of 10 with 2 simultaneous wavefronts, 1 of 10 with disorganized activity, and in 3 of 10 there was no coverage by the basket catheter at the corresponding 3D anatomical location. Rotors detected in 2D phase maps were not observed in the corresponding 3D phase maps. These findings may have implications for current systems that use 2D phase mapping. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  4. Acute left main coronary artery occlusion

    PubMed Central

    Burgazli, K. Mehmet; Bilgin, Mehmet; Soydan, Nedim; Chasan, Ridvan; Erdogan, Ali

    2013-01-01

    The treatment of an acute left main coronary artery occlusion still poses a challenge. In this case report we present a 50-year-old patient with an acute occlusion of the left main artery. After a successful angioplasty without “stenting” due to the complexity of the stenosis the patient underwent a successful bypass surgery. We discuss the therapeutic options of acute left main occlusion regarding medical, interventional and surgical options. PMID:24353543

  5. Sex differences in left/right confusion.

    PubMed

    Jordan, Kirsten; Wüstenberg, Torsten; Jaspers-Feyer, Fern; Fellbrich, Anja; Peters, Michael

    2006-01-01

    In agreement with the literature, females (n=269) gave themselves significantly poorer ratings than males (n=164) in evaluating their ability to make fast and accurate left/right judgments. In order to evaluate the ecological validity of the self-ratings, subjects were tested on a task that required fast and accurate left/right judgments, on a mental rotation task, and on a task that required navigation of a virtual maze. The correlations between the performances and self-ratings were computed. Both males and females who gave themselves very poor LRC (left/right confusion) ratings had significantly lower accuracy scores on the left/right judgement task than males and females with average ratings, but there was no sex-specific relation between LRC ratings and left/right judgements that would explain why females give themselves lower LRC ratings. For females only, a weak correlation between LRC scores and the learning of the virtual maze was observed, but no significant correlations were observed between LRC scores and mental rotation performance. We conclude that self-ratings on left/right confusion questions, although they yield reliable sex differences, are poor predictors of actual performance on spatial tasks that involve left/right judgements. Thus, and in support of earlier speculations (Sholl and Egeth, 1981; Teng and Lee, 1982; Williams et al., 1993), the principal cause of the marked sex differences in LRC self-ratings likely lies in a greater willingness of females to rate themselves more poorly on questions of this type than is the case for men.

  6. Positive Association of Video Game Playing with Left Frontal Cortical Thickness in Adolescents

    PubMed Central

    Kühn, Simone; Lorenz, Robert; Banaschewski, Tobias; Barker, Gareth J.; Büchel, Christian; Conrod, Patricia J.; Flor, Herta; Garavan, Hugh; Ittermann, Bernd; Loth, Eva; Mann, Karl; Nees, Frauke; Artiges, Eric; Paus, Tomas; Rietschel, Marcella; Smolka, Michael N.; Ströhle, Andreas; Walaszek, Bernadetta; Schumann, Gunter; Heinz, Andreas; Gallinat, Jürgen

    2014-01-01

    Playing video games is a common recreational activity of adolescents. Recent research associated frequent video game playing with improvements in cognitive functions. Improvements in cognition have been related to grey matter changes in prefrontal cortex. However, a fine-grained analysis of human brain structure in relation to video gaming is lacking. In magnetic resonance imaging scans of 152 14-year old adolescents, FreeSurfer was used to estimate cortical thickness. Cortical thickness across the whole cortical surface was correlated with self-reported duration of video gaming (hours per week). A robust positive association between cortical thickness and video gaming duration was observed in left dorsolateral prefrontal cortex (DLPFC) and left frontal eye fields (FEFs). No regions showed cortical thinning in association with video gaming frequency. DLPFC is the core correlate of executive control and strategic planning which in turn are essential cognitive domains for successful video gaming. The FEFs are a key region involved in visuo-motor integration important for programming and execution of eye movements and allocation of visuo-spatial attention, processes engaged extensively in video games. The results may represent the biological basis of previously reported cognitive improvements due to video game play. Whether or not these results represent a-priori characteristics or consequences of video gaming should be studied in future longitudinal investigations. PMID:24633348

  7. A 63 K phase change unit integrating with pulse tube cryocoolers

    NASA Astrophysics Data System (ADS)

    Chunhui, Kong; Liubiao, Chen; Sixue, Liu; Yuan, Zhou; Junjie, Wang

    2017-02-01

    This article presents the design and computer model results of an integrated cooler system which consists of a single stage pulse tube cryocooler integrated with a small amount of a phase change material. A cryogenic thermal switch was used to thermally connect the phase change unit to the cold end of the cryocooler. During heat load operation, the cryogenic thermal switch is turned off to avoid vibrations. The phase change unit absorbs heat loads by melting a substance in a constant pressure-temperature-volume process. Once the substance has been melted, the cryogenic thermal turned on, the cryocooler can then refreeze the material. Advantages of this type of cooler are no vibrations during sensor operations; the ability to absorb increased heat loads; potentially longer system lifetime; and a lower mass, volume and cost. A numerical model was constructed from derived thermodynamic relationships for the cooling/heating and freezing/melting processes.

  8. Anosognosia for hemiparesis after left-sided stroke.

    PubMed

    Baier, Bernhard; Vucurevic, Goran; Müller-Forell, Wibke; Glassl, Oliver; Geber, Christian; Dieterich, Marianne; Karnath, Hans-Otto

    2014-12-01

    In patients with left-sided lesions, anosognosia for hemiparesis (AHP) seems to be a rare phenomenon. It has been discussed whether this rareness might be due to an inevitable bias due to language dysfunction and whether the left hemisphere's role for our self-awareness of motor actions thus is underestimated. By applying functional magnetic resonance imaging (fMRI) we examined whether patients with AHP following a left hemisphere stroke show a regular, left-sided or a reversed, right-sided lateralization of language functions. Only the former observation would argue for an original role of the left hemisphere in self-awareness about limb function. In a consecutive series of 44 acute left-sided stroke patients, only one patient (=2%) was identified showing AHP. In this case, we could verify by using fMRI that lateralization of AHP and spatial neglect on the one hand and of language functions on the other hand were reversed. The present single case observation thus argues against an original role of the left hemisphere in self-awareness about limb function. We discuss the data in the context of previous observations in the literature. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Density of Plutonium Turnings Generated from Machining Activities

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gonzales, John Robert; Vigil, Duane M.; Jachimowski, Thomas A.

    The purpose of this project was to determine the density of plutonium (Pu) turnings generated from the range of machining activities, using both surrogate material and machined Pu turnings. Verify that 500 grams (g) of plutonium will fit in a one quart container using a surrogate equivalent volume and that 100 grams of Pu will fit in a one quart Savy container.

  10. Comparison of gating methods for the real-time analysis of left ventricular function in nonimaging blood pool studies

    PubMed Central

    Beard, Brian B.; Stewart, James R.; Shiavi, Richard G.; Lorenz, Christine H.

    2018-01-01

    Background Gating methods developed for electrocardiographic-triggered radionuclide ventriculography are being used with nonimaging detectors. These methods have not been compared on the basis of their real-time performance or suitability for determination of load-independent indexes of left ventricular function. This work evaluated the relative merits of different gating methods for nonimaging radionuclude ventriculographic studies, with particular emphasis on their suitability for real-time measurements and the determination of pressure-volume loops. Methods and Results A computer model was used to investigate the relative accuracy of forward gating, backward gating, and phase-mode gating. The durations of simulated left ventricular time-activity curves were randomly varied. Three acquisition parameters were considered: frame rate, acceptance window, and sample size. Twenty-five studies were performed for each combination of acquisition parameters. Hemodynamic and shape parameters from each study were compared with reference parameters derived directly from the random time-activity curves. Backward gating produced the largest errors under all conditions. For both forward gating and phase-mode gating, ejection fraction was underestimated and time to end systole and normalized peak ejection rate were overestimated. For the hemodynamic parameters, forward gating was marginally superior to phase-mode gating. The mean difference in errors between forward and phase-mode gating was 1.47% (SD 2.78%). However, for root mean square shape error, forward gating was several times worse in every case and seven times worse than phase-mode gating on average. Conclusions Both forward and phase-mode gating are suitable for real-time hemodynamic measurements by nonimaging techniques. The small statistical difference between the methods is not clinically significant. The true shape of the time-activity curve is maintained most accurately by phase-mode gating. PMID:9420820

  11. Acute decrease of left ventricular mechanical dyssynchrony and improvement of contractile state and energy efficiency after left ventricular restoration.

    PubMed

    Schreuder, Jan J; Castiglioni, Alessandro; Maisano, Francesco; Steendijk, Paul; Donelli, Andrea; Baan, Jan; Alfieri, Ottavio

    2005-01-01

    Surgical left ventricular restoration by means of endoventricular patch aneurysmectomy in patients with postinfarction aneurysm should result in acute improved left ventricular performance by decreasing mechanical dyssynchrony and increasing energy efficiency. Nine patients with left ventricular postinfarction aneurysm were studied intraoperatively before and after ventricular restoration with a conductance volume catheter to analyze pressure-volume relationships, energy efficiency, and mechanical dyssynchrony. The end-systolic elastance was used as a load-independent index of contractile state. Left ventricular energy efficiency was calculated from stroke work and total pressure-volume area. Segmental volume changes perpendicular to the long axis were used to calculate mechanical dyssynchrony. Statistical analysis was performed with the paired t test and least-squares linear regression. Endoventricular patch aneurysmectomy reduced end-diastolic volume by 37% (P < .001), with unchanged stroke volume. Systolic function improved, as derived from increased +dP/dt(max), by 42% (P < .03), peak ejection rate by 28% (P < .02), and ejection fraction by 16% (P < .0002). Early diastolic function improved, as shown by reduction of -dP/dt(max) by 34% (P < .006) and shortened tau by 30% (P < .001). Left ventricular end-systolic elastance increased from 1.2 +/- 0.6 to 2.2 +/- 1 mm Hg/mL (P < .001). Left ventricular energy efficiency increased by 36% (P < .002). Left ventricular mechanical dyssynchrony decreased during systole by 33% (P < .001) and during diastole by 20% (P < .005). Left ventricular restoration induced acute improvements in contractile state, energy efficiency, and relaxation, together with a decrease in left ventricular mechanical dyssynchrony.

  12. Clinical determinants and consequences of left ventricular hypertrophy.

    PubMed

    Messerli, F H

    1983-09-26

    The left ventricle adapts to an increased afterload such as that produced by arterial hypertension with concentric left ventricular hypertrophy. However, this adaptive process can be modified by a variety of physiologic and pathophysiologic states. Progressive aging, black race, and perhaps disorders with an increased sympathetic outflow seem to accelerate left ventricular hypertrophy. Obesity and other high cardiac output states predominantly produce dilatation of the left ventricle, and their combination with arterial hypertension results in eccentric left ventricular hypertrophy. Similarly, endurance exercise increases left ventricular volume more than wall thickness, whereas isometric exercise produces an increase in wall thickness only. The presence or absence of some physiologic and pathogenetic factors has direct implication on the assessment of what constitutes a "normal" left ventricular structure and function. Left ventricular hypertrophy has been shown to increase ventricular ectopic impulse generation and to put patients at a high risk of sudden death. Moreover, the increase in myocardial mass lowers coronary reserve and enhances cardiac oxygen requirements. Thus, the presence of left ventricular hypertrophy has to be considered as an ominous sign rather than as a benign adaptive process.

  13. Quantum phase transitions and phase diagram for a one-dimensional p-wave superconductor with an incommensurate potential.

    PubMed

    Cai, X

    2014-04-16

    The effect of the incommensurate potential is studied for the one-dimensional p-wave superconductor. It is determined by analyzing various properties, such as the superconducting gap, the long-range order of the correlation function, the inverse participation ratio and the Z2 topological invariant, etc. In particular, two important aspects of the effect are investigated: (1) as disorder, the incommensurate potential destroys the superconductivity and drives the system into the Anderson localized phase; (2) as a quasi-periodic potential, the incommensurate potential causes band splitting and turns the system with certain chemical potential into the band insulator phase. A full phase diagram is also presented in the chemical potential-incommensurate potential strength plane.

  14. Prediction and analysis of beta-turns in proteins by support vector machine.

    PubMed

    Pham, Tho Hoan; Satou, Kenji; Ho, Tu Bao

    2003-01-01

    Tight turn has long been recognized as one of the three important features of proteins after the alpha-helix and beta-sheet. Tight turns play an important role in globular proteins from both the structural and functional points of view. More than 90% tight turns are beta-turns. Analysis and prediction of beta-turns in particular and tight turns in general are very useful for the design of new molecules such as drugs, pesticides, and antigens. In this paper, we introduce a support vector machine (SVM) approach to prediction and analysis of beta-turns. We have investigated two aspects of applying SVM to the prediction and analysis of beta-turns. First, we developed a new SVM method, called BTSVM, which predicts beta-turns of a protein from its sequence. The prediction results on the dataset of 426 non-homologous protein chains by sevenfold cross-validation technique showed that our method is superior to the other previous methods. Second, we analyzed how amino acid positions support (or prevent) the formation of beta-turns based on the "multivariable" classification model of a linear SVM. This model is more general than the other ones of previous statistical methods. Our analysis results are more comprehensive and easier to use than previously published analysis results.

  15. Congenital left atrial appendage aneurysm

    PubMed Central

    Wang, Bin; Li, He; Zhang, Li; He, Lin; Zhang, Jing; Liu, Cong; Wang, Jing; Lv, Qing; Shang, Xiaoke; Liu, Jinping; Xie, Mingxing

    2018-01-01

    Abstract Rationale: Left atrial appendage aneurysms (LAAA) are rare. Patients with LAAA are often diagnosed incidentally or after cardiac tachyarrhythmia or systemic thromboembolism happen. Early diagnosis and surgical resection is of utmost importance to prevent hazardous adverse events. Patient concerns: We present a case of 46-year-old man with congenital LAAA. The individual in this manuscript has given written informed consent to publish these case details. Diagnoses: Imaging studies, such as echocardiography, cardiovascular computed tomography (CT) and magnetic resonance imaging (MRI), demonstrated the large cavity arising from the left atrial appendage. The diagnosis of LAAA was confirmed. Interventions: The patient underwent an aneurysmectomy without any complications. Outcomes: TTE confirmed the disappearance of the LAAA from the left parasternal short-axis view of the aortic root postoperatively. The patient remained asymptomatic without any adverse events at his 3-month follow-up visits. Lessons: The associated high risk of life-threatening complications and the relative ease of surgical removal suggest that prompt evaluation should be considered in patients with lesions adjacent to the left heart border. PMID:29480827

  16. Effects of dual task on turning ability in stroke survivors and older adults.

    PubMed

    Hollands, K L; Agnihotri, D; Tyson, S F

    2014-09-01

    Turning is an integral component of independent mobility in which stroke survivors frequently fall. This study sought to measure the effects of competing cognitive demands on the stepping patterns of stroke survivors, compared to healthy age-match adults, during turning as a putative mechanism for falls. Walking and turning (90°) was assessed under single (walking and turning alone) and dual task (subtracting serial 3s while walking and turning) conditions using an electronic, pressure-sensitive walkway. Dependent measures were time to turn, variability in time to turn, step length, step width and single support time during three steps of the turn. Turning ability in single and dual task conditions was compared between stroke survivors (n=17, mean ± SD: 59 ± 113 months post-stroke, 64 ± 10 years of age) and age-matched healthy counterparts (n=15). Both groups took longer, were more variable, tended to widen the second step and, crucially, increased single support time on the inside leg of the turn while turning and distracted. Increased single support time during turning may represent biomechanical mechanism, within stepping patterns of turning under distraction, for increased risk of falls for both stroke survivors and older adults. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  17. On the role of spatial phase and phase correlation in vision, illusion, and cognition

    PubMed Central

    Gladilin, Evgeny; Eils, Roland

    2015-01-01

    Numerous findings indicate that spatial phase bears an important cognitive information. Distortion of phase affects topology of edge structures and makes images unrecognizable. In turn, appropriately phase-structured patterns give rise to various illusions of virtual image content and apparent motion. Despite a large body of phenomenological evidence not much is known yet about the role of phase information in neural mechanisms of visual perception and cognition. Here, we are concerned with analysis of the role of spatial phase in computational and biological vision, emergence of visual illusions and pattern recognition. We hypothesize that fundamental importance of phase information for invariant retrieval of structural image features and motion detection promoted development of phase-based mechanisms of neural image processing in course of evolution of biological vision. Using an extension of Fourier phase correlation technique, we show that the core functions of visual system such as motion detection and pattern recognition can be facilitated by the same basic mechanism. Our analysis suggests that emergence of visual illusions can be attributed to presence of coherently phase-shifted repetitive patterns as well as the effects of acuity compensation by saccadic eye movements. We speculate that biological vision relies on perceptual mechanisms effectively similar to phase correlation, and predict neural features of visual pattern (dis)similarity that can be used for experimental validation of our hypothesis of “cognition by phase correlation.” PMID:25954190

  18. On the role of spatial phase and phase correlation in vision, illusion, and cognition.

    PubMed

    Gladilin, Evgeny; Eils, Roland

    2015-01-01

    Numerous findings indicate that spatial phase bears an important cognitive information. Distortion of phase affects topology of edge structures and makes images unrecognizable. In turn, appropriately phase-structured patterns give rise to various illusions of virtual image content and apparent motion. Despite a large body of phenomenological evidence not much is known yet about the role of phase information in neural mechanisms of visual perception and cognition. Here, we are concerned with analysis of the role of spatial phase in computational and biological vision, emergence of visual illusions and pattern recognition. We hypothesize that fundamental importance of phase information for invariant retrieval of structural image features and motion detection promoted development of phase-based mechanisms of neural image processing in course of evolution of biological vision. Using an extension of Fourier phase correlation technique, we show that the core functions of visual system such as motion detection and pattern recognition can be facilitated by the same basic mechanism. Our analysis suggests that emergence of visual illusions can be attributed to presence of coherently phase-shifted repetitive patterns as well as the effects of acuity compensation by saccadic eye movements. We speculate that biological vision relies on perceptual mechanisms effectively similar to phase correlation, and predict neural features of visual pattern (dis)similarity that can be used for experimental validation of our hypothesis of "cognition by phase correlation."

  19. ALMA long baseline phase calibration using phase referencing

    NASA Astrophysics Data System (ADS)

    Asaki, Yoshiharu; Matsushita, Satoki; Fomalont, Edward B.; Corder, Stuartt A.; Nyman, Lars-Åke; Dent, William R. F.; Philips, Neil M.; Hirota, Akihiko; Takahashi, Satoko; Vila-Vilaro, Baltasar; Nikolic, Bojan; Hunter, Todd R.; Remijan, Anthony; Vlahakis, Catherine

    2016-08-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) is the world's largest millimeter/submillimeter telescope and provides unprecedented sensitivities and spatial resolutions. To achieve the highest imaging capabilities, interferometric phase calibration for the long baselines is one of the most important subjects: The longer the baselines, the worse the phase stability becomes because of turbulent motions of the Earth's atmosphere, especially, the water vapor in the troposphere. To overcome this subject, ALMA adopts a phase correction scheme using a Water Vapor Radiometer (WVR) to estimate the amount of water vapor content along the antenna line of sight. An additional technique is phase referencing, in which a science target and a nearby calibrator are observed by turn by quickly changing the antenna pointing. We conducted feasibility studies of the hybrid technique with the WVR phase correction and the antenna Fast Switching (FS) phase referencing (WVR+FS phase correction) for the ALMA 16 km longest baselines in cases that (1) the same observing frequency both for a target and calibrator is used, and (2) higher and lower frequencies for a target and calibrator, respectively, with a typical switching cycle time of 20 s. It was found that the phase correction performance of the hybrid technique is promising where a nearby calibrator is located within roughly 3◦ from a science target, and that the phase correction with 20 s switching cycle time significantly improves the performance with the above separation angle criterion comparing to the 120 s switching cycle time. The currently trial phase calibration method shows the same performance independent of the observing frequencies. This result is especially important for the higher frequency observations because it becomes difficult to find a bright calibrator close to an arbitrary sky position. In the series of our experiments, it is also found that phase errors affecting the image quality come from not only

  20. Using support vector machine to predict beta- and gamma-turns in proteins.

    PubMed

    Hu, Xiuzhen; Li, Qianzhong

    2008-09-01

    By using the composite vector with increment of diversity, position conservation scoring function, and predictive secondary structures to express the information of sequence, a support vector machine (SVM) algorithm for predicting beta- and gamma-turns in the proteins is proposed. The 426 and 320 nonhomologous protein chains described by Guruprasad and Rajkumar (Guruprasad and Rajkumar J. Biosci 2000, 25,143) are used for training and testing the predictive model of the beta- and gamma-turns, respectively. The overall prediction accuracy and the Matthews correlation coefficient in 7-fold cross-validation are 79.8% and 0.47, respectively, for the beta-turns. The overall prediction accuracy in 5-fold cross-validation is 61.0% for the gamma-turns. These results are significantly higher than the other algorithms in the prediction of beta- and gamma-turns using the same datasets. In addition, the 547 and 823 nonhomologous protein chains described by Fuchs and Alix (Fuchs and Alix Proteins: Struct Funct Bioinform 2005, 59, 828) are used for training and testing the predictive model of the beta- and gamma-turns, and better results are obtained. This algorithm may be helpful to improve the performance of protein turns' prediction. To ensure the ability of the SVM method to correctly classify beta-turn and non-beta-turn (gamma-turn and non-gamma-turn), the receiver operating characteristic threshold independent measure curves are provided. (c) 2008 Wiley Periodicals, Inc.

  1. Impaired Left Atrial Strain as a Predictor of New-onset Atrial Fibrillation After Aortic Valve Replacement Independently of Left Atrial Size.

    PubMed

    Pessoa-Amorim, Guilherme; Mancio, Jennifer; Vouga, Luís; Ribeiro, José; Gama, Vasco; Bettencourt, Nuno; Fontes-Carvalho, Ricardo

    2018-06-01

    Left atrial dysfunction in aortic stenosis may precede atrial enlargement and predict the occurrence of atrial fibrillation (AF). To test this hypothesis, we assessed left atrial function and determined its impact on the incidence of AF after aortic valve replacement. A total of 149 severe aortic stenosis patients (74±8.6 years, 51% men) with no prior AF were assessed using speckle-tracking echocardiography. Left atrial function was evaluated using peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and phasic left atrial volumes. The occurrence of AF was monitored in 114 patients from surgery until hospital discharge. In multiple linear regression, PALS and PACS were inversely correlated with left atrial dilation, left ventricular hypertrophy, and diastolic function. Atrial fibrillation occurred in 36 patients within a median time of 3 days [interquartile range, 1-4] after aortic valve replacement. In multiple Cox regression, PALS and PACS were independently associated with the incidence of AF (HR, 0.946; 95%CI, 0.910-0.983; P=.005 and HR, 0.932; 95%CI, 0.883-0.984; P=.011, respectively), even after further adjustment for left atrial dimensions. Both reduced PALS and PACS were associated with the incidence of AF in patients with nondilated left atria (P value for the interaction of PALS with left atrial dimensions=.013). In severe aortic stenosis, left atrial dysfunction predicted the incidence of postoperative AF independently of left atrial dilation, suggesting that speckle-tracking echocardiography before surgery may help in risk stratification, particularly in patients with nondilated left atria. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  2. pi-Turns: types, systematics and the context of their occurrence in protein structures

    PubMed Central

    Dasgupta, Bhaskar; Chakrabarti, Pinak

    2008-01-01

    Background For a proper understanding of protein structure and folding it is important to know if a polypeptide segment adopts a conformation inherent in the sequence or it depends on the context of its flanking secondary structures. Turns of various lengths have been studied and characterized starting from three-residue γ-turn to six-residue π-turn. The Schellman motif occurring at the C-terminal end of α-helices is a classical example of hydrogen bonded π-turn involving residues at (i) and (i+5) positions. Hydrogen bonded and non-hydrogen bonded β- and α-turns have been identified previously; likewise, a systematic characterization of π-turns would provide valuable insight into turn structures. Results An analysis of protein structures indicates that at least 20% of π-turns occur independent of the Schellman motif. The two categories of π-turns, designated as π-HB and SCH, have been further classified on the basis of backbone conformation and both have AAAa as the major class. They differ in the residue usage at position (i+1), the former having a large preference for Pro that is absent in the latter. As in the case of shorter length β- and α-turns, π-turns have also been identified not only on the basis of the existence of hydrogen bond, but also using the distance between terminal Cα-atoms, and this resulted in a comparable number of non-hydrogen-bonded π-turns (π-NHB). The presence of shorter β- and α-turns within all categories of π-turns, the subtle variations in backbone torsion angles along the turn residues, the location of the turns in the context of tertiary structures have been studied. Conclusion π-turns have been characterized, first using hydrogen bond and the distance between Cα atoms of the terminal residues, and then using backbone torsion angles. While the Schellman motif has a structural role in helix termination, many of the π-HB turns, being located on surface cavities, have functional role and there is also sequence

  3. pi-Turns: types, systematics and the context of their occurrence in protein structures.

    PubMed

    Dasgupta, Bhaskar; Chakrabarti, Pinak

    2008-09-22

    For a proper understanding of protein structure and folding it is important to know if a polypeptide segment adopts a conformation inherent in the sequence or it depends on the context of its flanking secondary structures. Turns of various lengths have been studied and characterized starting from three-residue gamma-turn to six-residue pi-turn. The Schellman motif occurring at the C-terminal end of alpha-helices is a classical example of hydrogen bonded pi-turn involving residues at (i) and (i+5) positions. Hydrogen bonded and non-hydrogen bonded beta- and alpha-turns have been identified previously; likewise, a systematic characterization of pi-turns would provide valuable insight into turn structures. An analysis of protein structures indicates that at least 20% of pi-turns occur independent of the Schellman motif. The two categories of pi-turns, designated as pi-HB and SCH, have been further classified on the basis of backbone conformation and both have AAAa as the major class. They differ in the residue usage at position (i+1), the former having a large preference for Pro that is absent in the latter. As in the case of shorter length beta- and alpha-turns, pi-turns have also been identified not only on the basis of the existence of hydrogen bond, but also using the distance between terminal C alpha-atoms, and this resulted in a comparable number of non-hydrogen-bonded pi-turns (pi-NHB). The presence of shorter beta- and alpha-turns within all categories of pi-turns, the subtle variations in backbone torsion angles along the turn residues, the location of the turns in the context of tertiary structures have been studied. pi-turns have been characterized, first using hydrogen bond and the distance between C alpha atoms of the terminal residues, and then using backbone torsion angles. While the Schellman motif has a structural role in helix termination, many of the pi-HB turns, being located on surface cavities, have functional role and there is also sequence

  4. Simulative and experimental investigation on stator winding turn and unbalanced supply voltage fault diagnosis in induction motors using Artificial Neural Networks.

    PubMed

    Lashkari, Negin; Poshtan, Javad; Azgomi, Hamid Fekri

    2015-11-01

    The three-phase shift between line current and phase voltage of induction motors can be used as an efficient fault indicator to detect and locate inter-turn stator short-circuit (ITSC) fault. However, unbalanced supply voltage is one of the contributing factors that inevitably affect stator currents and therefore the three-phase shift. Thus, it is necessary to propose a method that is able to identify whether the unbalance of three currents is caused by ITSC or supply voltage fault. This paper presents a feedforward multilayer-perceptron Neural Network (NN) trained by back propagation, based on monitoring negative sequence voltage and the three-phase shift. The data which are required for training and test NN are generated using simulated model of stator. The experimental results are presented to verify the superior accuracy of the proposed method. Copyright © 2015. Published by Elsevier Ltd.

  5. Topological side-chain classification of beta-turns: ideal motifs for peptidomimetic development.

    PubMed

    Tran, Tran Trung; McKie, Jim; Meutermans, Wim D F; Bourne, Gregory T; Andrews, Peter R; Smythe, Mark L

    2005-08-01

    Beta-turns are important topological motifs for biological recognition of proteins and peptides. Organic molecules that sample the side chain positions of beta-turns have shown broad binding capacity to multiple different receptors, for example benzodiazepines. Beta-turns have traditionally been classified into various types based on the backbone dihedral angles (phi2, psi2, phi3 and psi3). Indeed, 57-68% of beta-turns are currently classified into 8 different backbone families (Type I, Type II, Type I', Type II', Type VIII, Type VIa1, Type VIa2 and Type VIb and Type IV which represents unclassified beta-turns). Although this classification of beta-turns has been useful, the resulting beta-turn types are not ideal for the design of beta-turn mimetics as they do not reflect topological features of the recognition elements, the side chains. To overcome this, we have extracted beta-turns from a data set of non-homologous and high-resolution protein crystal structures. The side chain positions, as defined by C(alpha)-C(beta) vectors, of these turns have been clustered using the kth nearest neighbor clustering and filtered nearest centroid sorting algorithms. Nine clusters were obtained that cluster 90% of the data, and the average intra-cluster RMSD of the four C(alpha)-C(beta) vectors is 0.36. The nine clusters therefore represent the topology of the side chain scaffold architecture of the vast majority of beta-turns. The mean structures of the nine clusters are useful for the development of beta-turn mimetics and as biological descriptors for focusing combinatorial chemistry towards biologically relevant topological space.

  6. Expendable Air Vehicles/High Altitude Balloon Technology. Phase 1.

    DTIC Science & Technology

    1991-08-02

    CHR/91 -2750 I I I I I THIS PAGE INTENTIONALLY LEFT BLANK 3 I I U I I I I I I I I I CHR/91 -2750 PREFACE The work described in this Phase II SBIR...Final Technical Report is the implementation of a capability which Coleman Research Corporation demon- strated during a Phase I SBIR (contract number...CRC) has developed a Balloon Drift Pattern Simulation 1BDPS). CRC developed this simulation software for digital computers as a product of a Phase II

  7. Type I and II β-turns prediction using NMR chemical shifts.

    PubMed

    Wang, Ching-Cheng; Lai, Wen-Chung; Chuang, Woei-Jer

    2014-07-01

    A method for predicting type I and II β-turns using nuclear magnetic resonance (NMR) chemical shifts is proposed. Isolated β-turn chemical-shift data were collected from 1,798 protein chains. One-dimensional statistical analyses on chemical-shift data of three classes β-turn (type I, II, and VIII) showed different distributions at four positions, (i) to (i + 3). Considering the central two residues of type I β-turns, the mean values of Cο, Cα, H(N), and N(H) chemical shifts were generally (i + 1) > (i + 2). The mean values of Cβ and Hα chemical shifts were (i + 1) < (i + 2). The distributions of the central two residues in type II and VIII β-turns were also distinguishable by trends of chemical shift values. Two-dimensional cluster analyses on chemical-shift data show positional distributions more clearly. Based on these propensities of chemical shift classified as a function of position, rules were derived using scoring matrices for four consecutive residues to predict type I and II β-turns. The proposed method achieves an overall prediction accuracy of 83.2 and 84.2% with the Matthews correlation coefficient values of 0.317 and 0.632 for type I and II β-turns, indicating that its higher accuracy for type II turn prediction. The results show that it is feasible to use NMR chemical shifts to predict the β-turn types in proteins. The proposed method can be incorporated into other chemical-shift based protein secondary structure prediction methods.

  8. Exposure to lateral collision in signalized intersections with protected left turn under different traffic control strategies.

    PubMed

    Midenet, Sophie; Saunier, Nicolas; Boillot, Florence

    2011-11-01

    This paper proposes an original definition of the exposure to lateral collision in signalized intersections and discusses the results of a real world experiment. This exposure is defined as the duration of situations where the stream that is given the right-of-way goes through the conflict zone while road users are waiting in the cross-traffic approach. This measure, obtained from video sensors, makes it possible to compare different operating conditions such as different traffic signal strategies. The data from a real world experiment is used, where the adaptive real-time strategy CRONOS (ContRol Of Networks by Optimization of Switchovers) and a time-plan strategy with vehicle-actuated ranges alternately controlled an isolated intersection near Paris. Hourly samples with similar traffic volumes are compared and the exposure to lateral collision is different in various areas of the intersection and various traffic conditions for the two strategies. The total exposure under peak hour traffic conditions drops by roughly 5 min/h with the CRONOS strategy compared to the time-plan strategy, which occurs mostly on entry streams. The results are analyzed through the decomposition of cycles in phase sequences and recommendations are made for traffic control strategies. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Head turning as a prominent motor symptom in status epilepticus.

    PubMed

    Bauer, Gerhard; Broessner, Gregor; Unterberger, Iris; Walser, Gerald; Pfausler, Bettina; Trinka, Eugen

    2008-06-01

    Head and eye turning is frequently observed during seizures. Versions with tonic and/or clonic symptoms can be differentiated from smooth head deviations. Head turning as a prominent symptom of status epilepticus has not previously been reported. We present eight case reports, (7 women/1 man, mean age 41 years, median 41.5, range 10 to 74), of status epilepticus (SE), with head turning as a prominent motor symptom. Six were accompanied by continuous frontal, occipital and temporal ictal epileptiform discharges. Furthermore, two patients had absence status with rhythmic and clonic head versions. While the localizing significance of head turnings in SE is low, in our cases, the direction was away from the discharging hemisphere in all cases of focal SE regardless of whether the turning was classified as version (three cases) or deviation (three cases). In this small series of SE, the classical observation of a patient looking away from the discharging hemisphere is still valid.

  10. Switching handedness: fMRI study of hand motor control in right-handers, left-handers and converted left-handers.

    PubMed

    Grabowska, Anna; Gut, Malgorzata; Binder, Marek; Forsberg, Lars; Rymarczyk, Krystyna; Urbanik, Andrzej

    2012-01-01

    The purpose of this study was to investigate the differences in the brain organization of motor control in left- and right-handers and to study whether early left-to-right handwriting switch changes the cortical representation of finger movements in the left and right hemispheres. Echo-planar MR imaging was performed in 52 subjects: consistent right-handers (RH), consistent left-handers (LH), and subjects who had been forced at an early age to switch their left-hand preferences toward the right side. The scanning was performed during simple (flexion/extension of the index finger) and complex (successive finger-thumb opposition) tasks. Subjects performed the tasks using both the preferred and non-preferred hand. In right-handers, there was a general predominance of left-hemisphere activation relative to right hemisphere activation. In lefthanders this pattern was reversed. The switched subjects showed no such volumetric asymmetry. Increasing levels of complexity of motor activity resulted in an increase in the volume of consistently activated areas and the involvement of the ipsilateral in addition to contralateral activations. In both right- and left-handers, movements of the preferred hand activated mainly the contralateral hemisphere, whereas movements of the non-preferred hand resulted in a more balanced pattern of activation in the two hemispheres, indicating greater involvement of the ipsilateral activations. Overall, this study shows that in both left- and right-handed subjects, the preferred hand is controlled mainly by the hemisphere contralateral to that hand, whereas the non-preferred hand is controlled by both hemispheres. The switched individuals share features of both lefthanders and right-handers regarding their motor control architectures.

  11. Professional Employees Turn to Unions

    ERIC Educational Resources Information Center

    Chamot, Dennis

    1976-01-01

    White-collar and professional employees are increasingly turning to unions to combat their loss of independence as employees of large organizations. Managers should realize that they and professional employees have different viewpoints about job situations and that the current trend toward white-collar unionism is apt to continue. (JG)

  12. Asymmetric vibration in a two-layer vocal fold model with left-right stiffness asymmetry: Experiment and simulation

    PubMed Central

    Zhang, Zhaoyan; Hieu Luu, Trung

    2012-01-01

    Vibration characteristics of a self-oscillating two-layer vocal fold model with left-right asymmetry in body-layer stiffness were experimentally and numerically investigated. Two regimes of distinct vibratory pattern were identified as a function of left-right stiffness mismatch. In the first regime with extremely large left-right stiffness mismatch, phonation onset resulted from an eigenmode synchronization process that involved only eigenmodes of the soft fold. Vocal fold vibration in this regime was dominated by a large-amplitude vibration of the soft fold, and phonation frequency was determined by the properties of the soft fold alone. The stiff fold was only enslaved to vibrate at a much reduced amplitude. In the second regime with small left-right stiffness mismatch, eigenmodes of both folds actively participated in the eigenmode synchronization process. The two folds vibrated with comparable amplitude, but the stiff fold consistently led the soft fold in phase for all conditions. A qualitatively good agreement was obtained between experiment and simulation, although the simulations generally underestimated phonation threshold pressure and onset frequency. The clinical implications of the results of this study are also discussed. PMID:22978891

  13. Asymmetric vibration in a two-layer vocal fold model with left-right stiffness asymmetry: experiment and simulation.

    PubMed

    Zhang, Zhaoyan; Luu, Trung Hieu

    2012-09-01

    Vibration characteristics of a self-oscillating two-layer vocal fold model with left-right asymmetry in body-layer stiffness were experimentally and numerically investigated. Two regimes of distinct vibratory pattern were identified as a function of left-right stiffness mismatch. In the first regime with extremely large left-right stiffness mismatch, phonation onset resulted from an eigenmode synchronization process that involved only eigenmodes of the soft fold. Vocal fold vibration in this regime was dominated by a large-amplitude vibration of the soft fold, and phonation frequency was determined by the properties of the soft fold alone. The stiff fold was only enslaved to vibrate at a much reduced amplitude. In the second regime with small left-right stiffness mismatch, eigenmodes of both folds actively participated in the eigenmode synchronization process. The two folds vibrated with comparable amplitude, but the stiff fold consistently led the soft fold in phase for all conditions. A qualitatively good agreement was obtained between experiment and simulation, although the simulations generally underestimated phonation threshold pressure and onset frequency. The clinical implications of the results of this study are also discussed.

  14. Wheelchair caster shimmy and turning resistance.

    PubMed

    Kauzlarich, J J; Bruning, T; Thacker, J G

    1984-07-01

    The equations for wheelchair caster wheel shimmy are presented along with experimental data. The report includes the theory and performance of single wheel casters for a variety of tires, and a new design for wheelchair casters using a grooved dual-tread tire or co-rotating caster wheels. The dual-tread tire was found to significantly inhibit caster shimmy. The turning resistance due to a grooved caster wheel tire with a 1/2-inch groove was found to be 10 percent greater than for an ungrooved caster wheel tire. The analysis includes the methodology and the results of experiments developed to measure the sliding friction turning moment of the wheelchair caster wheel. A number of commercial wheelchair caster wheels were tested and the results for shimmy are presented.

  15. Defining the loop structures in proteins based on composite β-turn mimics.

    PubMed

    Dhar, Jesmita; Chakrabarti, Pinak

    2015-06-01

    Asx- and ω-turns are β-turn mimics, which replace the conventional main-chain hydrogen bonds seen in the latter by those involving the side chains, and both involve three residues. In this paper we analyzed the cases where these turns occur together--side by side, with or without any gap, overlapping and in any order. These composite turns (of length 3-15 residues), occurring at ∼1 per 100 residues, may constitute the full length of many loops, and when the residues in the two component turns overlap or are adjacent to each other, the composite may take well-defined shape. It is thus possible for non-regular regions in protein structure to form local structural motifs, akin to the regular geometrical features exhibited by secondary structures. Composites having the order ω-turns followed by Asx-turns can constitute N-terminal helix capping motif. Ternary composite turns (made up of ω-, Asx- and ST-turns), some with characteristic shape, have also been identified. Delineation of composite turns would help in characterizing loops in protein structures, which often have functional roles. Some sequence patterns seen in composites can be used for their incorporation in protein design. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  16. Modification of impulse generation during piqué turns with increased rotational demands.

    PubMed

    Zaferiou, Antonia M; Wilcox, Rand R; McNitt-Gray, Jill L

    2016-06-01

    During initiation of a piqué turn, a dancer generates impulse to achieve the desired lateral translation and whole-body rotation. The goal of this study was to determine how individuals regulate impulse generation when initiating piqué turns with increased rotational demands. Skilled dancers (n=10) performed single (∼360°) and double (∼720°) piqué turns from a stationary position. Linear and angular impulse generated by the push and turn legs were quantified using ground reaction forces and compared across turn conditions as a group and within a dancer using probability-based statistical methods. The results indicate that as the rotation demands of the piqué turn increased, the net angular impulse generated increased whereas net lateral impulse decreased. Early during turn initiation, the free moment contributed to angular impulse generation. Later during turn initiation, horizontal reaction forces were controlled to generate angular impulse. As rotational demands increased, the moment applied increased primarily from redirection of the horizontal reaction force (RFh) at the push leg and a combination of RFh magnitude and moment arm increases at the turn leg. RFh at each leg were coordinated to limit unwanted net linear impulse. Knowledge of observed subject-specific mechanisms is important to inform the design of turning performance training tools. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Detonation corner turning in vapor-deposited explosives using the micromushroom test

    NASA Astrophysics Data System (ADS)

    Tappan, Alexander S.; Yarrington, Cole D.; Knepper, Robert

    2017-06-01

    Detonation corner turning describes the ability of a detonation wave to propagate into unreacted explosive that is not immediately in the path normal to the wave. The classic example of corner turning is cylindrical and involves a small diameter explosive propagating into a larger diameter explosive as described by Los Alamos' Mushroom test (e.g. (Hill, Seitz et al. 1998)), where corner turning is inferred from optical breakout of the detonation wave. We present a complimentary method to study corner turning in millimeter-scale explosives through the use of vapor deposition to prepare the slab (quasi-2D) analog of the axisymmetric mushroom test. Because the samples are in a slab configuration, optical access to the explosive is excellent and direct imaging of the detonation wave and ``dead zone'' that results during corner turning is possible. Results are compared for explosives that demonstrate a range of behaviors, from pentaerythritol tetranitrate (PETN), which has corner turning properties that are nearly ideal; to HNAB (hexanitroazobenzene), which has corner turning properties that reveal a substantial dead zone. Results are discussed in the context of microstructure and detonation failure thickness.

  18. Effects of Parkinson's disease on brain-wave phase synchronisation and cross-modulation

    NASA Astrophysics Data System (ADS)

    Stumpf, K.; Schumann, A. Y.; Plotnik, M.; Gans, F.; Penzel, T.; Fietze, I.; Hausdorff, J. M.; Kantelhardt, J. W.

    2010-02-01

    We study the effects of Parkinson's disease (PD) on phase synchronisation and cross-modulation of instantaneous amplitudes and frequencies for brain waves during sleep. Analysing data from 40 full-night EEGs (electro-encephalograms) of ten patients with PD and ten age-matched healthy controls we find that phase synchronisation between the left and right hemisphere of the brain is characteristically reduced in patients with PD. Since there is no such difference in phase synchronisation for EEGs from the same hemisphere, our results suggest the possibility of a relation with problems in coordinated motion of left and right limbs in some patients with PD. Using the novel technique of amplitude and frequency cross-modulation analysis, relating oscillations in different EEG bands and distinguishing both positive and negative modulation, we observe an even more significant decrease in patients for several band combinations.

  19. Tool wear mechanisms in turning titanium-aluminum-vanadium using tungsten carbide and polycrystalline diamond inserts

    NASA Astrophysics Data System (ADS)

    Schrock, David James

    The objective of this work is to identify some of the tool wear mechanisms at the material level for the machining of titanium and to provide some understanding of these mechanisms for use in physics based tool wear models. Turning experiments were conducted at cutting speeds of 61m/min, 91m/min, and 122m/min on Ti-6Al-4V, an alloy of titanium, using two different grades of tungsten carbide cutting inserts and one grade of polycrystalline diamond inserts. Three-dimensional wear data and two-dimensional wear profiles of the rake face were generated using Confocal Laser Scanning Microscopy to quantify the tool wear mechanisms. Additionally, the microstructure of the deformed work material (chip) and un-deformed parent material (work piece) were studied using Orientation Imaging Microscopy (OIM). Observations from tool wear studies on the PCD inserts revealed the presence of two fundamentally different wear mechanisms operating at the different cutting speeds. Microstructural analyses of the chip and the work material showed phase dependent tool wear mechanisms for machining titanium. There is a high likelihood of phase change occurring in the work material during machining, with a transformation from the alpha phase to the beta phase. The observed dramatic increase in wear is attributed to a combination of increased diffusivity in the beta phase of the titanium alloy in conjunction with a higher degree of recrystallization of the prior beta phase upon cooling. Results of other observations such as the influence of carbide grain size on tool wear are also discussed.

  20. Diastolic function of the nonfilling human left ventricle.

    PubMed

    Paulus, W J; Vantrimpont, P J; Rousseau, M F

    1992-12-01

    To investigate an early-diastolic left ventricular suction effect in humans, tip-micromanometer left ventricular pressure recordings were obtained in patients with mitral stenosis at the time of balloon inflations during percutaneous mitral valvuloplasty performed with a self-positioning Inoue balloon, which fits tightly in the mitral orifice. When mitral inflow was impeded in anesthetized dogs, left ventricular pressure decayed to a negative asymptote value. This negative asymptote value was consistent with an early diastolic suction effect. Tip-micromanometer left ventricular pressure recordings were obtained in 23 patients with symptomatic mitral stenosis at the time of balloon inflations during percutaneous mitral valvuloplasty performed with a self-positioning Inoue balloon. The left ventricular diastolic asymptote pressure (P(asy)) was determined in 47 nonfilling beats with a sufficiently long (greater than 200 ms) diastolic time interval (that is, the interval from minimal first derivative of left ventricular pressure to left ventricular end-diastolic pressure) and equaled 2 +/- 3 mm Hg for beats with normal intraventricular conduction and 3 +/- 2 mm Hg for beats with aberrant intraventricular conduction. Left ventricular angiography was performed in five patients during the first inflation of the Inoue balloon at the time of complete balloon expansion. Left ventricular end-diastolic volume of the nonfilling beats averaged 38 +/- 14 ml and was comparable to the left ventricular end-systolic volume (39 +/- 19 ml) measured during baseline angiography before mitral valvuloplasty. Time constants of left ventricular pressure decay were calculated on 21 nonfilling beats with a diastolic time interval greater than 200 ms, normal intraventricular conduction and peak left ventricular pressure greater than 50 mm Hg. Time constants (T0 and TBF) derived from an exponential curve fit with zero asymptote pressure and with a best-fit asymptote pressure were compared with a