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1

Effects of knee and ankle muscle fatigue on postural control in the unipedal stance  

Microsoft Academic Search

The aim of this study was to compare the effects of acute muscle fatigue of the ankle and knee musculature on postural control\\u000a by immediate measures after performing fatiguing tasks (POST condition). One group of subjects (n = 8) performed a fatiguing task by voluntary contractions of the triceps surae (group TRI) and the other (n = 9) performed a fatiguing task by voluntary

Riadh Bizid; Eric Margnes; Yrieix François; Jean Louis Jully; Gerard Gonzalez; Philippe Dupui; Thierry Paillard

2009-01-01

2

The interaction between the location of lower extremity muscle fatigue and visual condition on unipedal postural stability.  

PubMed

The purpose of this study was to investigate the effects of unilateral muscle fatigue induced on the hip flexors/extensors or the ankle plantar/dorsiflexors on unipedal postural stability under different visual conditions. Twenty-four healthy young women completed 2 testing sessions 1 week apart with a randomized order assigned according to the muscles tested. During each session, one set of muscle groups was fatigued using isokinetic contractions: ankle plantar/dorsi flexors or hip flexor/extensors. Postural stability was assessed during trials of unilateral stance on a force plate before and after the fatigue protocol. 10 s into the trial, subjects were asked to close their eyes. Mean velocity, the area of the 95% confidence ellipse, and standard deviation of velocity in anteroposterior and mediolateral directions of center of pressure displacements were calculated for two periods of 5 s, immediately before and 1 s after the eyes closure. The results of the repeated measures ANOVAs showed a significant fatigue-by-fatigue segment by visual condition interaction for the CoP parameters. When the vision was removed, the interaction between fatigue and fatigue segment was significant for the CoP parameters. In conclusion, fatigue in both proximal and distal musculature of the lower extremity yielded decreased postural stability during unipedal quiet standing in healthy young women. This effect was more accentuated when visual information was eliminated. Withdrawing vision following fatigue to the proximal musculature, led to a significantly greater impairment of postural stability compared to the fatigue of more distal muscles. PMID:22297610

Soleimanifar, Manijeh; Salavati, Mahyar; Akhbari, Behnam; Moghadam, Mojgan

2012-10-01

3

Asymmetric balance control between legs for quiet but not for perturbed stance.  

PubMed

Interlateral performance asymmetry in upright balance control was evaluated in this investigation by comparing unipedal stance on the right versus the left leg. Participants were healthy young adults, hand-foot congruent preference for the right body side. Balance performance was evaluated in unperturbed quiet stance and in the recovery of balance stability following a mechanical perturbation induced by unexpected load release. Evaluation was made under availability of full sensory information, and under deprivation of vision combined with distortion of sensory inputs from the feet soles. Results from perturbed posture revealed that muscular response latency and postural sway were symmetric between the legs. Unipedal stance was more stable when the body was supported on the right as compared with the left leg. No interaction was found between leg and sensory condition. Our findings are interpreted as resulting from specialization of the sensorimotor system controlling the right leg for continuous low-magnitude postural adjustments, while corrections to large-scale stance sway are symmetrically controlled between body sides. PMID:24954557

Vieira, Osvaldo; Coelho, Daniel Boari; Teixeira, Luis Augusto

2014-10-01

4

Triggering the intentional stance  

Microsoft Academic Search

While humans possess a ready capacity to view a target (biological or other- wise) as an intentional agent (i.e. the 'intentional stance'), the conditions necessary for spontaneously eliciting these mentalizing processes are less well understood. Although research examining people's tendency to construe the motion of geometric shapes as intentional has done much to illuminate this issue, due to methodological limitations

Raymond A. Mar; C. Neil Macrae

2006-01-01

5

Soccer players have a better standing balance in nondominant one-legged stance  

PubMed Central

The purpose of this study was to analyze the differences in standing balance during dominant and nondominant one-legged stance among athletes of different sports and sedentary subjects. The right-footed subjects of four groups (sedentary, n = 20; soccer, n = 20; basketball, n = 20; windsurfer n = 20) underwent 5-sec unipedal (left and right foot) stabilometric analysis with open eyes and closed eyes to measure center of pressure (COP) sway path and COP velocity (mean value, anteroposterior, and laterolateral in millimeters per second). The soccer group showed better standing balance on the left leg than the sedentary group (P < 0.05). No other significant differences were observed within and amongst groups. The soccer players have a better standing balance on the nondominant leg because of soccer activity. PMID:24198563

Barone, Rosario; Macaluso, Filippo; Traina, Marcello; Leonardi, Vincenza; Farina, Felicia; Di Felice, Valentina

2011-01-01

6

"The Road to Freedom": How One Salvadoran Youth Takes an Agentive Stance to Narrate the Self across Time and Space  

ERIC Educational Resources Information Center

In this article, we use narrative theory to analyze and discuss how one Salvadoran youth, Thomas, constructed three different yet overlapping narratives, including a digital story, on his family's movement across borders. We describe how each telling of his narratives is situated in time and space, where Thomas reveals his understandings of…

McGinnis, Theresa Ann; Garcia, Andrea

2012-01-01

7

Effect of lower limb muscle fatigue on anticipatory postural adjustments associated with bilateral-forward reach in the unipedal dominant and non-dominant stance  

Microsoft Academic Search

Voluntary arm movements are preceded by dynamical and electromyographical (EMG) phenomena in “postural segments” (i.e. body\\u000a segments not directly involved in the voluntary movement) called “anticipatory postural adjustments” (APA). The present study\\u000a examined how the central nervous system organizes APA under fatigued state of postural musculature elicited by series of high-level\\u000a isometric contractions (HIC), i.e. corresponding to 60% of maximal

M. Mezaour; E. Yiou; S. Le Bozec

2010-01-01

8

Individuals with diminished hip abductor muscle strength exhibit altered ankle biomechanics and neuromuscular activation during unipedal balance tasks.  

PubMed

Coordinated control of the hip and ankle is important for maintaining postural stability. The purpose of the study was to compare postural stability between individuals with contrasting hip abductor strength during unipedal balance tasks and to determine whether diminished hip abductor strength results in greater utilization of the ankle strategy to maintain balance. Forty-five females (276±35 years) participated in the study. Participants were ranked based on their isometric hip abductor muscle strength. The top 33% of the participants were categorized as the strong group (n=15) and the lower 33% as the weak group (n=15). Each subject performed a static and a dynamic unipedal balance task, during which mean COP displacement, peak ankle invertor and evertor moments, and neuromuscular activation of the lower leg muscles were assessed. Two-way mixed analyses of variance tests with task as a repeated factor were performed to detect the effects of task and group on the variables of interest. When averaged across tasks, mean medial-lateral COP displacement was significantly greater in the weak group (136±117 vs. 98±60 mm, p=0.05). The weak group also exhibited greater peak ankle invertor and evertor moments (0.31±0.10 vs. 0.25±0.11 Nm/kg, p=0.03; 0.04±0.06 vs. -0.02±0.07 Nm/kg, p=0.01), and increased peroneus longus activation (46±12 vs. 36±15%, p<0.01). Our results demonstrate that individuals with diminished hip abductor muscle strength demonstrated decreased medial-lateral postural stability, and exhibited a shift toward utilizing an ankle strategy to maintain balance during unipedal tasks. PMID:24373699

Lee, Szu-Ping; Powers, Christopher M

2014-03-01

9

Stance width influences frontal plane balance responses to centripetal accelerations.  

PubMed

Whenever the body is moving in a curvilinear path, inertial torques resulting from centripetal accelerations act on the body and must be counteracted to maintain stability. We tested the hypothesis that healthy subjects orient their center of mass in the position where gravitational torques offset the inertial torques due to centripetal accelerations. Ten healthy subjects stood on a platform that rotated in a circle at either a slow or fast speed, eyes open or closed, and in narrow or wide stance. Upper body, lower body, and center of mass (CoM) tilt with respect to vertical were measured and averaged across a 40 second time period of constant velocity. Body tilt was compared to the gravito-inertial acceleration (GIA) angle with respect to vertical. In all moving conditions, the upper body, lower body, and CoM tilted inward. However, this inward tilt did not reach the predicted GIA angle (CoM tilt was ~78% and 39% toward the predicted GIA angle in narrow and wide stance, respectively). Ratios of body tilt to GIA angle were minimally influenced by visual availability and magnitude of centripetal acceleration; but were largely influenced by stance width whereby narrow stance inward tilt was greater than wide stance. These results further highlight the important influence of the base of support on balance control strategies and enhance our understanding of how the balance control system compensates for inertial torques generated from centripetal accelerations. PMID:22819010

Goodworth, Adam; Chandan, Aditi; Chase, Hannah; Foster, Elizabeth; Francoeur, Heather; Michaud, Jenna; Terry, Kathryn

2013-01-01

10

The Collective Stance in Modeling Expertise in Individuals and Organizations  

Microsoft Academic Search

This paper is concerned with modeling the nature of expertise and its role in society in relation to research on expert systems and enterprise models. It argues for the adoption of a collective stance in which the human species is viewed as a single organism recursively partitioned in space and time into sub-organisms that are similar to the whole. These

Brian R. Gaines

1994-01-01

11

Narrative Stance in the Douglass Autobiographies.  

ERIC Educational Resources Information Center

To consider Frederick Douglass as an autobiographer, it is useful to examine each of his three autobiographical texts with a view to drawing some conclusion about their relation to one another, and about the relation of the author to each one. It seems likely that the shifting of Douglass' narrative stance is an index of his intellectual…

Davidson, Phebe

12

Effects of unipedal standing balance exercise on the prevention of falls and hip fracture among clinically defined high-risk elderly individuals: a randomized controlled trial  

Microsoft Academic Search

Background  The aim of this study was to assess the effectiveness of the unipedal standing balance exercise for 1?min to prevent falls\\u000a and hip fractures in high-risk elderly individuals with a randomized controlled trial. This control study was designed as\\u000a a 6-month intervention trial.\\u000a \\u000a \\u000a \\u000a Subjects  Subjects included 553 clinically defined high-risk adults who were living in residences or in the community. They

Keizo Sakamoto; Toshitaka Nakamura; Hiroshi Hagino; Naoto Endo; Satoshi Mori; Yoshiteru Muto; Atsushi Harada; Tetsuo Nakano; Eiji Itoi; Mitsuo Yoshimura; Hiromichi Norimatsu; Hiroshi Yamamoto; Takahiro Ochi

2006-01-01

13

Methods for exploring expressive stance  

Microsoft Academic Search

The postures a character adopts over time are a key expressive aspect of her movement. While IK tools help a character achieve positioning constraints, there are few tools that help an animator with the expressive aspects of a character's poses. Three aspects are combined in good pose design: achieving a set of world space constraints, finding a body shape that

Michael Neff; Eugene Fiume

2004-01-01

14

Do footedness and strength asymmetry relate to the dominant stance in swimming track start?  

Microsoft Academic Search

This study explored the relationship between lower limb asymmetry and stance preference in the swimming track start. Track start performances and asymmetry measures were collected from 11 male and 11 female competitive age group swimmers. The track start performance was defined as the time taken to reach the 5-m mark. Asymmetry measures included assessment of footedness using the revised version

Julie Hardt; Nat Benjanuvatra; Brian Blanksby

2009-01-01

15

Assessing Muscle Stiffness from Quiet Stance in Parkinson's Disease  

E-print Network

Assessing Muscle Stiffness from Quiet Stance in Parkinson's Disease Michael Lauk 1;2;4 , MSc Stiffness from Quiet Stance: Applicability to Parkinson's Disease Abstract In previous studies, we developed this measure to patients with Parkinson's disease (PD). We correlated the postural stiffness measure

16

Stance, Navigation, and Reader Response in Expository Hypertext  

ERIC Educational Resources Information Center

This article reports on two studies investigating reader stance, navigation, and response in expository hypertext. Subjects in the studies included 69 and 147 adult readers prompted to adopt either an efferent or aesthetic stance when reading a 36-node expository hypertext. Reading was followed by recall and essay writing tasks. Results of the…

McEneaney, John E.; Li, Ledong; Allen, Kris; Guzniczak, Lizabeth

2009-01-01

17

The Effects of Argument Stance on Scientific Knowledge Inquiry Skills  

ERIC Educational Resources Information Center

This study investigates the effects of argument stance on knowledge inquiry skills. Sixty-two participants were assigned to three argument stance conditions (proponent, opponent, or control) to receive scaffolded argumentation practice on two science issues in random order. After the argumentation treatment, participants were asked to write down…

Horng, Ruey-Yun; Lu, Po-Hui; Chen, Pei-Hua; Hou, Shih-Huan

2013-01-01

18

Stance, Navigation, and Reader Response in Expository Hypertext  

Microsoft Academic Search

This article reports on two studies investigating reader stance, navigation, and response in expository hypertext. Subjects in the studies included 69 and 147 adult readers prompted to adopt either an efferent or aesthetic stance when reading a 36-node expository hypertext. Reading was followed by recall and essay writing tasks. Results of the studies indicate that prompts can be designed to

John E. McEneaney; Ledong Li; Kris Allen; Lizabeth Guzniczak

2009-01-01

19

Effect of stance width on multidirectional postural responses  

NASA Technical Reports Server (NTRS)

The effect of stance width on postural responses to 12 different directions of surface translations was examined. Postural responses were characterized by recording 11 lower limb and trunk muscles, body kinematics, and forces exerted under each foot of 7 healthy subjects while they were subjected to horizontal surface translations in 12 different, randomly presented directions. A quasi-static approach of force analysis was done, examining force integrals in three different epochs (background, passive, and active periods). The latency and amplitude of muscle responses were quantified for each direction, and muscle tuning curves were used to determine the spatial activation patterns for each muscle. The results demonstrate that the horizontal force constraint exerted at the ground was lessened in the wide, compared with narrow, stance for humans, a similar finding to that reported by Macpherson for cats. Despite more trunk displacement in narrow stance, there were no significant changes in body center of mass (CoM) displacement due to large changes in center of pressure (CoP), especially in response to lateral translations. Electromyographic (EMG) magnitude decreased for all directions in wide stance, particularly for the more proximal muscles, whereas latencies remained the same from narrow to wide stance. Equilibrium control in narrow stance was more of an active postural strategy that included regulating the loading/unloading of the limbs and the direction of horizontal force vectors. In wide stance, equilibrium control relied more on an increase in passive stiffness resulting from changes in limb geometry. The selective latency modulation of the proximal muscles with translation direction suggests that the trunk was being actively controlled in all directions. The similar EMG latencies for both narrow and wide stance, with modulation of only the muscle activation magnitude as stance width changed, suggest that the same postural synergy was only slightly modified for a change in stance width. Nevertheless, the magnitude of the trunk displacement, as well as of CoP displacement, was modified based on the degree of passive stiffness in the musculoskeletal system, which increased with stance width. The change from a more passive to an active horizontal force constraint, to larger EMG magnitudes especially in the trunk muscles and larger trunk and CoP excursions in narrow stance are consistent with a more effortful response for equilibrium control in narrow stance to perturbations in all directions.

Henry, S. M.; Fung, J.; Horak, F. B.; Peterson, B. W. (Principal Investigator)

2001-01-01

20

EMG responses to maintain stance during multidirectional surface translations  

NASA Technical Reports Server (NTRS)

To characterize muscle synergy organization underlying multidirectional control of stance posture, electromyographic activity was recorded from 11 lower limb and trunk muscles of 7 healthy subjects while they were subjected to horizontal surface translations in 12 different, randomly presented directions. The latency and amplitude of muscle responses were quantified for each perturbation direction. Tuning curves for each muscle were examined to relate the amplitude of the muscle response to the direction of surface translation. The latencies of responses for the shank and thigh muscles were constant, regardless of perturbation direction. In contrast, the latencies for another thigh [tensor fascia latae (TFL)] and two trunk muscles [rectus abdominis (RAB) and erector spinae (ESP)] were either early or late, depending on the perturbation direction. These three muscles with direction-specific latencies may play different roles in postural control as prime movers or as stabilizers for different translation directions, depending on the timing of recruitment. Most muscle tuning curves were within one quadrant, having one direction of maximal activity, generally in response to diagonal surface translations. Two trunk muscles (RAB and ESP) and two lower limb muscles (semimembranosus and peroneus longus) had bipolar tuning curves, with two different directions of maximal activity, suggesting that these muscle can play different roles as part of different synergies, depending on translation direction. Muscle tuning curves tended to group into one of three regions in response to 12 different directions of perturbations. Two muscles [rectus femoris (RFM) and TFL] were maximally active in response to lateral surface translations. The remaining muscles clustered into one of two diagonal regions. The diagonal regions corresponded to the two primary directions of active horizontal force vector responses. Two muscles (RFM and adductor longus) were maximally active orthogonal to their predicted direction of maximal activity based on anatomic orientation. Some of the muscles in each of the synergic regions were not anatomic synergists, suggesting a complex central organization for recruitment of muscles. The results suggest that neither a simple reflex mechanism nor a fixed muscle synergy organization is adequate to explain the muscle activation patterns observed in this postural control task. Our results are consistent with a centrally mediated pattern of muscle latencies combined with peripheral influence on muscle magnitude. We suggest that a flexible continuum of muscle synergies that are modifiable in a task-dependent manner be used for equilibrium control in stance.

Henry, S. M.; Fung, J.; Horak, F. B.; Peterson, B. W. (Principal Investigator)

1998-01-01

21

Direct corticospinal pathways contribute to neuromuscular control of perturbed stance.  

PubMed

The antigravity soleus muscle (Sol) is crucial for compensation of stance perturbation. A corticospinal contribution to the compensatory response of the Sol is under debate. The present study assessed spinal, corticospinal, and cortical excitability at the peaks of short- (SLR), medium- (MLR), and long-latency responses (LLR) after posterior translation of the feet. Transcranial magnetic stimulation (TMS) and peripheral nerve stimulation were individually adjusted so that the peaks of either motor evoked potential (MEP) or H reflex coincided with peaks of SLR, MLR, and LLR, respectively. The influence of specific, presumably direct, corticospinal pathways was investigated by H-reflex conditioning. When TMS was triggered so that the MEP arrived in the Sol at the same time as the peaks of SLR and MLR, EMG remained unaffected. Enhanced EMG was observed when the MEP coincided with the LLR peak (P < 0.001). Similarly, conditioning of the H reflex by subthreshold TMS facilitated H reflexes only at LLR (P < 0.001). The earliest facilitation after perturbation occurred after 86 ms. The TMS-induced H-reflex facilitation at LLR suggests that increased cortical excitability contributes to the augmentation of the LLR peaks. This provides evidence that the LLR in the Sol muscle is at least partly transcortical, involving direct corticospinal pathways. Additionally, these results demonstrate that approximately 86 ms after perturbation, postural compensatory responses are cortically mediated. PMID:16601305

Taube, Wolfgang; Schubert, Martin; Gruber, Markus; Beck, Sandra; Faist, Michael; Gollhofer, Albert

2006-08-01

22

Observational stance as a predictor of subjective and genital sexual arousal in men and women.  

PubMed

Observational stance refers to the perspective a person takes while viewing a sexual stimulus, either as a passive observer (observer stance) or an active participant (participant stance). The objective of the current study was to examine the relationship between observational stance and sexual arousal (subjective and genital) across a range of sexual stimuli that do or do not correspond with a participant's sexual attraction (preferred or nonpreferred stimuli, respectively). Regression analyses revealed that, for men (n = 44), participant stance significantly predicted subjective and genital arousal. Women's (n = 47) observer and participant stance predicted subjective arousal but not genital arousal. Analysis of variance showed that participant stance was greatest under preferred sexual stimuli conditions for all groups of participants, while observer stance scores revealed a less consistent pattern of response. This was particularly true for opposite-sex-attracted women, whose ratings of observer stance were lowest for preferred stimuli. Observational stance does not appear to account for gender differences in specificity of sexual arousal; for men, however, participant stance uniquely predicted genital response after controlling for sexual attractions. Similarities in the relationships between men's and women's observational stance and sexual responses challenge previous claims of gender differences in how men and women view erotica. PMID:23514448

Bossio, Jennifer A; Spape, Jessica; Lykins, Amy D; Chivers, Meredith L

2014-01-01

23

Balance in Astronauts Performing Jumps, Walking and Quiet Stance Following Spaceflight  

NASA Technical Reports Server (NTRS)

Introduction: Both balance and locomotor ataxia is severe in astronauts returning from spaceflight with serious implications for unassisted landings. As a part of an ongoing effort to demonstrate the functional significance of the postflight ataxia problem our laboratory has evaluated jumping, walking heel-to-toe and quite stance balance immediately following spaceflight. Methods: Six astronauts from 12-16 day flights and three from 6-month flights were asked to perform three self-initiated two-footed jumps from a 30-cm-high platform, walking for 10 steps (three trials) placing the feet heel to toe in tandem, arms folded across the chest and the eyes closed, and lastly, recover from a simulated fall by standing from a prone position on the floor and with eyes open maintain a quiet stance for 3 min with arms relaxed along the side of the body and feet comfortably positioned on a force plate. Crewmembers were tested twice before flight, on landing day (short-duration), and days 1, 6, and 30 following all flight durations. Results/Conclusions: Many of astronauts tested fell on their first postflight jump but recovered by the third jump showing a rapid learning progression. Changes in take-off strategy were clearly evident in duration of time in the air between the platform and the ground (significant reduction in time to land), and also in increased asymmetry in foot latencies on take-off postflight. During the tandem heel-to-toe walking task there was a significant decrease in percentage of correct steps on landing day (short-duration crew) and on first day following landing (long-duration) with only partial recovery the following day. Astronauts for both short and long duration flight times appeared to be unaware of foot position relative to their bodies or the floor. During quite stance most of crewmembers tested exhibited increased stochastic activity (larger short-term COP diffusion coefficients postflight in all planes and increases in mean sway speed).

Reschke, Millard F.; Bloomberg, J. J.; Wood, S. J.; Harm, D. L.

2011-01-01

24

The analyst's stance and the method of free association.  

PubMed

The concept of the analyst's stance is employed to organize a number of ideas about psychoanalytic work, past and present, especially from the viewpoint of the method of free association. Beginning with an emphasis on the intrinsic uncertainties and paradoxes of the analytic process, the author reviews the importance of words, the aim of mastering resistances (i.e., promoting freedom of association), and functional neutrality on the analyst's part. The problem of anonymity is considered from a number of angles. Two traditions of transference are described, deriving from Freud's overlapping early formulations. The distinction between old and new determinants in the two kinds of transference is useful and important in the analyst's stance. Attitudes toward insight, resistance, and conflict resolution are considered from the perspective of the distinction between divergent and convergent conflicts, with special emphasis on the role of punitive, unconscious self-criticism. PMID:2251309

Kris, A O

1990-01-01

25

Coherence analysis of muscle activity during quiet stance  

Microsoft Academic Search

Studies of muscle activation during perturbed standing have demonstrated that the typical patterns of coordination (“ankle\\u000a strategy” and “hip strategy”) are controlled through multiple muscles activated in a distal-to-proximal or proximal-to-distal\\u000a temporal pattern. In contrast, quiet stance is thought to be maintained primarily through the ankle musculature. Recently,\\u000a spectral analysis of inter-segment body motion revealed the coexistence of both ankle

Mark Saffer; Tim Kiemel; John Jeka

2008-01-01

26

Potential roles of force cues in human stance control  

Microsoft Academic Search

Human stance is inherently unstable. A small deviation from upright body orientation is enough to yield a gravitational component\\u000a in the ankle joint torque, which tends to accelerate the body further away from upright (‘gravitational torque’; magnitude\\u000a is related to body-space lean angle). Therefore, to maintain a given body lean position, a corresponding compensatory torque\\u000a must be generated. It is

Christian Cnyrim; Thomas Mergner; Christoph Maurer

2009-01-01

27

Verified Analysis of a Model for Stance Stabilization  

Microsoft Academic Search

\\u000a The stabilization of stance is a subject of continuing research in biology, biomechanics and robotics. It plays an important\\u000a role in many clinical applications as well as in forward dynamical gait simulation. In this paper, we propose a new model\\u000a relying on a two cylinder foot contact scheme. This contact model has the advantage of simple and smooth dynamic behavior

Ekaterina Auer; Haider Albassam; Andrés Kecskeméthy; Wolfram Luther

28

Stance width changes how sensory feedback is used for multisegmental balance control.  

PubMed

A multilink sensorimotor integration model of frontal plane balance control was developed to determine how stance width influences the use of sensory feedback in healthy adults. Data used to estimate model parameters came from seven human participants who stood on a continuously rotating surface with three different stimulus amplitudes, with eyes open and closed, and at four different stance widths. Dependent variables included lower body (LB) and upper body (UB) sway quantified by frequency-response functions. Results showed that stance width had a major influence on how parameters varied across stimulus amplitude and between visual conditions. Active mechanisms dominated LB control. At narrower stances, with increasing stimulus amplitude, subjects used sensory reweighting to shift reliance from proprioceptive cues to vestibular and/or visual cues that oriented the LB more toward upright. When vision was available, subjects reduced reliance on proprioception and increased reliance on vision. At wider stances, LB control did not exhibit sensory reweighting. In the UB system, both active and passive mechanisms contributed and were dependent on stance width. UB control changed across stimulus amplitude most in wide stance (opposite of the pattern found in LB control). The strong influence of stance width on sensory integration and neural feedback control implies that rehabilitative therapies for balance disorders can target different aspects of balance control by using different stance widths. Rehabilitative strategies designed to assess or modify sensory reweighting will be most effective with the use of narrower stances, whereas wider stances present greater challenges to UB control. PMID:24760788

Goodworth, Adam D; Mellodge, Patricia; Peterka, Robert J

2014-08-01

29

A robotic cadaveric flatfoot analysis of stance phase.  

PubMed

The symptomatic flatfoot deformity (pes planus with peri-talar subluxation) can be a debilitating condition. Cadaveric flatfoot models have been employed to study the etiology of the deformity, as well as invasive and noninvasive surgical treatment strategies, by evaluating bone positions. Prior cadaveric flatfoot simulators, however, have not leveraged industrial robotic technologies, which provide several advantages as compared with the previously developed custom fabricated devices. Utilizing a robotic device allows the researcher to experimentally evaluate the flatfoot model at many static instants in the gait cycle, compared with most studies, which model only one to a maximum of three instances. Furthermore, the cadaveric tibia can be statically positioned with more degrees of freedom and with a greater accuracy, and then a custom device typically allows. We created a six degree of freedom robotic cadaveric simulator and used it with a flatfoot model to quantify static bone positions at ten discrete instants over the stance phase of gait. In vivo tibial gait kinematics and ground reaction forces were averaged from ten flatfoot subjects. A fresh frozen cadaveric lower limb was dissected and mounted in the robotic gait simulator (RGS). Biomechanically realistic extrinsic tendon forces, tibial kinematics, and vertical ground reaction forces were applied to the limb. In vitro bone angular position of the tibia, calcaneus, talus, navicular, medial cuneiform, and first metatarsal were recorded between 0% and 90% of stance phase at discrete 10% increments using a retroreflective six-camera motion analysis system. The foot was conditioned flat through ligament attenuation and axial cyclic loading. Post-flat testing was repeated to study the pes planus deformity. Comparison was then made between the pre-flat and post-flat conditions. The RGS was able to recreate ten gait positions of the in vivo pes planus subjects in static increments. The in vitro vertical ground reaction force was within ± 1 standard deviation (SD) of the in vivo data. The in vitro sagittal, coronal, and transverse plane tibial kinematics were almost entirely within ± 1 SD of the in vivo data. The model showed changes consistent with the flexible flatfoot pathology including the collapse of the medial arch and abduction of the forefoot, despite unexpected hindfoot inversion. Unlike previous static flatfoot models that use simplified tibial degrees of freedom to characterize only the midpoint of the stance phase or at most three gait positions, our simulator represented the stance phase of gait with ten discrete positions and with six tibial degrees of freedom. This system has the potential to replicate foot function to permit both noninvasive and surgical treatment evaluations throughout the stance phase of gait, perhaps eliciting unknown advantages or disadvantages of these treatments at other points in the gait cycle. PMID:21599096

Jackson, Lyle T; Aubin, Patrick M; Cowley, Matthew S; Sangeorzan, Bruce J; Ledoux, William R

2011-05-01

30

Limb-Bone Scaling Indicates Diverse Stance and Gait in Quadrupedal Ornithischian Dinosaurs  

PubMed Central

Background The most primitive ornithischian dinosaurs were small bipeds, but quadrupedality evolved three times independently in the clade. The transition to quadrupedality from bipedal ancestors is rare in the history of terrestrial vertebrate evolution, and extant analogues do not exist. Constraints imposed on quadrupedal ornithischians by their ancestral bipedal bauplan remain unexplored, and consequently, debate continues about their stance and gait. For example, it has been proposed that some ornithischians could run, while others consider that none were cursorial. Methodology/Principal Findings Drawing on biomechanical concepts of limb bone scaling and locomotor theory developed for extant taxa, we use the largest dataset of ornithischian postcranial measurements so far compiled to examine stance and gait in quadrupedal ornithischians. Differences in femoral midshaft eccentricity in hadrosaurs and ceratopsids may indicate that hadrosaurs placed their feet on the midline during locomotion, while ceratopsids placed their feet more laterally, under the hips. More robust humeri in the largest ceratopsids relative to smaller taxa may be due to positive allometry in skull size with body mass in ceratopsids, while slender humeri in the largest stegosaurs may be the result of differences in dermal armor distribution within the clade. Hadrosaurs are found to display the most cursorial morphologies of the quadrupedal ornithischian cades, indicating higher locomotor performance than in ceratopsids and thyreophorans. Conclusions/Significance Limb bone scaling indicates that a previously unrealised diversity of stances and gaits were employed by quadrupedal ornithischians despite apparent convergence in limb morphology. Grouping quadrupedal ornithischians together as a single functional group hides this disparity. Differences in limb proportions and scaling are likely due to the possession of display structures such as horns, frills and dermal armor that may have affected the center of mass of the animal, and differences in locomotor behaviour such as migration, predator escape or home range size. PMID:22666333

Maidment, Susannah C. R.; Linton, Deborah H.; Upchurch, Paul; Barrett, Paul M.

2012-01-01

31

Eldecalcitol improves chair-rising time in postmenopausal osteoporotic women treated with bisphosphonates  

PubMed Central

An open-label randomized controlled trial was conducted to clarify the effect of eldecalcitol (ED) on body balance and muscle power in postmenopausal osteoporotic women treated with bisphosphonates. A total of 106 postmenopausal women with osteoporosis (mean age 70.8 years) were randomly divided into two groups (n=53 in each group): a bisphosphonate group (control group) and a bisphosphonate plus ED group (ED group). Biochemical markers, unipedal standing time (body balance), and five-repetition chair-rising time (muscle power) were evaluated. The duration of the study was 6 months. Ninety-six women who completed the trial were included in the subsequent analyses. At baseline, the age, body mass index, bone mass indices, bone turnover markers, unipedal standing time, and chair-rising time did not differ significantly between the two groups. During the 6-month treatment period, bone turnover markers decreased significantly from the baseline values similarly in the two groups. Although no significant improvement in the unipedal standing time was seen in the ED group, compared with the control group, the chair-rising time decreased significantly in the ED group compared with the control group. The present study showed that ED improved the chair-rising time in terms of muscle power in postmenopausal osteoporotic women treated with bisphosphonates. PMID:24476669

Iwamoto, Jun; Sato, Yoshihiro

2014-01-01

32

Climate Literacy for Kids: Finding Medium, Message, and Stance  

NASA Astrophysics Data System (ADS)

As part of NASA's Global Climate Change (climate.nasa.gov) website (winner of the 2011Webby Award for Best Science Site), Climate Kids (climate.nasa.gov/kids) presents positive role models for green careers and encourages kids to be good climate citizens. But before they will care, they must understand. Climate Kids helps kids understand climate science by communicating at their own science awareness and maturity level, and by giving them concrete ways to start helping Earth now. Climate Kids, as informal education, speaks to upper-elementary-school-age kids in their own language and using some of their favorite media. In addition to simple, liberally illustrated text explanations of the basic science concepts, cartoons and games reinforce the concepts in a fun way. A growing section on green careers interviews enthusiastic individuals currently practicing their professions. In explaining what they do, these individuals reinforce the climate science concepts and "how to help" suggestions elsewhere on the site. The games also reinforce the green career choices. "Green Careers" currently features a "green" general contractor, a home energy auditor, a water-wise landscaper, a recycling program educator, and a renewable energy scientist. The message of the scientist, who designs wind energy farms and "architectural wind" arrays, is reinforced by the "Power-up" game. In this game, players move a wind turbine up or down to capture the wind and move a solar array back and forth to stay out of cloud shadows. Depending on how many "windows" of the game's "city" light up using these alternative energy sources, the player earns a bronze, silver, gold, or platinum "medal." A recycling game reinforces the messages of the recycling program educator about the importance of recycling in saving energy, what can and cannot be recycled, and how long trash items remain in a landfill before decomposing. In the game, a variety of throw-away objects rains down from the top of the screen. Various recycling bins (glass, plastic, metal, and paper) are lined up on the left and right sides of the screen, with a trash bin at the bottom. As an item drops, the player must quickly decide what kind of material it is made of and whether it is recyclable, then guide it into the appropriate bin. As the rate of items entering play increases, any missed items fall into the trash and stay there for a length of time proportional to their decomposition time. If the trash bin gets full, the game is over. While enjoying the increasing challenge of the game, players learn to identify many items as recyclable that they may not have recognized as recyclable before. Another feature on Climate Kids is "Climate Tales," a slightly edgy animated cartoon series (two episodes so far) about the adventures of a blundering polar bear, a chirpy tamarin monkey, and a grumpy old fish as "accidental tourists" around the planet, observing and dealing with the environmental conditions they encounter. Fairly complex concepts (such as reasons and implications of the declining abundance of phytoplankton) are woven into the tales. Climate Kids is a fun site for kids, educational and realistic, and yet positive and hopeful-the only reasonable stance to present to this young audience.

Fisher, D. K.; Leon, N.; Jackson, R.; Greene, M. P.

2011-12-01

33

Potential roles of force cues in human stance control.  

PubMed

Human stance is inherently unstable. A small deviation from upright body orientation is enough to yield a gravitational component in the ankle joint torque, which tends to accelerate the body further away from upright ('gravitational torque'; magnitude is related to body-space lean angle). Therefore, to maintain a given body lean position, a corresponding compensatory torque must be generated. It is well known that subjects use kinematic sensory information on body-space lean from the vestibular system for this purpose. Less is known about kinetic cues from force/torque receptors. Previous work indicated that they are involved in compensating external contact forces such as a pull or push having impact on the body. In this study, we hypothesized that they play, in addition, a role when the vestibular estimate of the gravitational torque becomes erroneous. Reasons may be sudden changes in body mass, for instance by a load, or an impairment of the vestibular system. To test this hypothesis, we mimicked load effects on the gravitational torque in normal subjects and in patients with chronic bilateral vestibular loss (VL) with eyes closed. We added/subtracted extra torque to the gravitational torque by applying an external contact force (via cable winches and a body harness). The extra torque was referenced to body-space lean, using different proportionality factors. We investigated how it affected body-space lean responses that we evoked using sinusoidal tilts of the support surface (motion platform) with different amplitudes and frequencies (normals +/-1 degrees, +/-2 degrees, and +/-4 degrees at 0.05, 0.1, 0.2, and 0.4 Hz; patients +/-1 degrees and +/-2 degrees at 0.05 and 0.1 Hz). We found that added/subtracted extra torque scales the lean response in a systematic way, leading to increase/decrease in lean excursion. Expressing the responses in terms of gain and phase curves, we compared the experimental findings to predictions obtained from a recently published sensory feedback model. For the trials in which the extra torque tended to endanger stance control, predictions in normals were better when the model included force cues than without these cues. This supports our notion that force cues provide an automatic 'gravitational load compensation' upon changes in body mass in normals. The findings in the patients support our notion that the presumed force cue mechanism provides furthermore vestibular loss compensation. Patients showed a body-space stabilization that cannot be explained by ankle angle proprioception, but must involve graviception, most likely by force cues. Our findings suggest that force cues contribute considerably to the redundancy and robustness of the human stance control system. PMID:19219426

Cnyrim, Christian; Mergner, Thomas; Maurer, Christoph

2009-04-01

34

A Cross-Cultural Analysis of Stance in Disaster News Reports  

ERIC Educational Resources Information Center

This study examines stance in cross-cultural media discourse by comparing disaster news reports on the Sichuan earthquake of May 2008 in a Chinese, an Australian Chinese, and an Australian newspaper. The stance taken in the news reports is examined using the Attitude sub-system of Martin and White's (2005) Appraisal framework. The analysis…

Liu, Lian; Stevenson, Marie

2013-01-01

35

Pedagogical Stances of High School ESL Teachers: Huelgas in High School ESL Classrooms  

Microsoft Academic Search

This article presents a qualitative case study of the pedagogical stances of high school English as a Second Language (ESL) teachers, and the subsequent responses of resistance or conformity by their English Language Learners (ELLs). The participants include three high school ESL teachers and 60 high school ESL students of Mexican origin. Findings indicate that dehumanizing pedagogical stances by ESL

María del Carmen Salazar

2010-01-01

36

Signaling Organization and Stance: Academic Language Use in Middle Grade Persuasive Writing  

ERIC Educational Resources Information Center

Effective academic writing is accessible to readers because writers follow shared conventions for organization and signal their stance on particular topics; however, few specifics are known about how middle graders might develop knowledge of and use these academic language forms and functions to signal their organization and stance in persuasive…

Dobbs, Christina L.

2014-01-01

37

Linguistic Markers of Stance in Early and Advanced Academic Writing: A Corpus-Based Comparison  

ERIC Educational Resources Information Center

This article uses corpus methods to examine linguistic expressions of stance in over 4,000 argumentative essays written by incoming first-year university students in comparison with the writing of upper-level undergraduate students and published academics. The findings reveal linguistic stance markers shared across the first-year essays despite…

Aull, Laura L.; Lancaster, Zak

2014-01-01

38

Ninth Grade Students' Negotiation of Aesthetic, Efferent, and Critical Stances in Response to a Novel Set in Afghanistan  

ERIC Educational Resources Information Center

This qualitative, action research study was guided by two primary research questions. First, how do students negotiate aesthetic, efferent, and critical stances when reading a novel set in Afghanistan? Second, how do aesthetic and efferent stances contribute to or hinder the adoption of a critical stance? A large body of research exists that…

Taliaferro, Cheryl

2011-01-01

39

Organization position statements and the stance of "studied neutrality" on euthanasia in palliative care.  

PubMed

In recent years, palliative care and related organizations have increasingly adopted a stance of "studied neutrality" on the question of whether euthanasia should be legalized as a bona fide medical regimen in palliative care contexts. This stance, however, has attracted criticism from both opponents and proponents of euthanasia. Pro-euthanasia activists see the stance as an official position of indecision that is fundamentally disrespectful of a patient's right to "choose death" when life has become unbearable. Some palliative care constituents, in turn, are opposed to the stance, contending that it reflects an attitude of "going soft" on euthanasia and as weakening the political resistance that has hitherto been successful in preventing euthanasia from becoming more widely legalized. In this article, attention is given to examining critically the notion and possible unintended consequences of adopting a stance of studied neutrality on euthanasia in palliative care. It is argued that although palliative care and related organizations have an obvious stake in the outcome of the euthanasia debate, it is neither unreasonable nor inconsistent for such organizations to be unwilling to take a definitive stance on the issue. It is further contended that, given the long-standing tenets of palliative care, palliative care organizations have both a right and a responsibility to defend the integrity of the principles and practice of palliative care and to resist demands for euthanasia to be positioned either as an integral part or logical extension of palliative care. PMID:22771130

Johnstone, Megan-Jane

2012-12-01

40

Learning effects associated with the least stable level of the biodex® stability system during dual and single limb stance.  

PubMed

The Biodex® Stability System (BSS) has high test-retest reliability when stable (high) resistance levels are used. However, reliability data for lower stability levels, associated with more pronounced learning curves, are rare in the existing literature. Thus, it is likely that BSS scores obtained from lower stability levels require greater familiarization (i.e. practice) to achieve a stable score both within and between test sessions. Therefore, the purpose of this investigation was to determine if a commonly reported 6 trial sequence (3 practice trials, 3 test trials) used with the BSS can achieve a stable within session score on the lowest stability level (i.e. level 1). The secondary purpose was to evaluate the test-retest reliability of the lowest BSS resistance level over a 10-week period. Twenty sedentary university students (11 male, 9 female; age: 21.5 ± 1.9 years, height: 1.7 ± 0.1 m, weight: 66.3 ± 12.1 kg, BMI: 22.4 ± 2.3) voluntarily participated. Participants completed two test sessions separated by 10-weeks. Twelve, 20-second trials (six dual limb stance, six single limb stance on the dominant limb) on the lowest stability level were completed during both test sessions by all participants. A stable within session dual and single limb stance score was achieved with a maximum of 3 familiarization trials. Reliability ranged between poor and good across all outcomes but all outcomes had large minimal detectable change scores. At least 3 stance specific familiarization trials are needed to achieve a stable BSS score within a single test session on the lowest resistance level. However, the inconsistent reliability and high minimal detectable changes scores suggest that the lowest resistance level should not be used as an objective marker of rehabilitation progress over extended periods of time (e.g. 10-weeks). Key pointsLevel 1 BSS scores should not be used as a test setting to assess rehabilitation.Familiarization trials should not be underestimated by researchers/clinicans.Lower stability levels on the BSS may not be appropriate for use as an objective marker of progression due to poor reliability of the scores over time. PMID:24790494

Cug, Mutlu; Wikstrom, Erik A

2014-05-01

41

Wavelet-based intensity analysis of mechanomyographic signals during single-legged stance following fatigue.  

PubMed

The von Tscharner (2000) "intensity analysis" describes the power of a non-stationary signal as a function of both frequency and time. The present study applied a version of this intensity analysis that utilizes Morlet wavelets as a means of gaining insight into the application of this technique as alternative to power spectral analysis for the evaluation of postural control strategy during the single-legged stance and to examine the effects of fatigue. Ten subjects (gender balanced, age: 25±3 years; height: 169.4±11.7 cm; weight: 79.0±16.9 kg) participated in two trials consisting of five 15-s dominant-leg stances. Three-uniaxial accelerometers were fixed to the surface of the dominant leg corresponding to VM, VL, SOL, and MMG was recorded at a sampling rate of 1000 Hz. Signals were later analyzed using a variation of the von Tscharner intensity analysis consisting of a filter bank of 11 Morlet wavelets (range: 2.1-131.1Hz). Two Wingate anaerobic tests (WAnT) separated by a 2-min rest were performed to introduce fatigue. Repeated measures ANOVAs showed significant effects for time, gender, trial, and wavelet (p<0.001) and significant interactions for muscle by wavelet, gender by trial, trial by wavelet, and gender by trial by wavelet (p<0.001). Peak total MMG intensity (mean±SD) was higher in males than females and higher following fatiguing exercise preWAnT (squared ms(-2)): 42.6±4.5 vs. 19.2±2.3; postWAnT (squared ms(-2)): 90.4±9.1 vs. 28.4±2.8. Peak total MMG intensity was compressed to the lower frequencies surrounding ?12 Hz, corresponding to what might be considered physiologic tremor, and a lower peak at ?42 Hz was most prominent in SOL. The intensity analysis is a useful tool in exploring postural control and in studying the effects of fatigue on the mechanical properties of skeletal muscle. PMID:21708471

Armstrong, W Jeffrey

2011-10-01

42

In vivo length patterns of the medial collateral ligament during the stance phase of gait  

PubMed Central

Purpose The function of the medial collateral ligament (MCL) during gait has not been investigated. Our objective was to measure the kinematics of the medial collateral ligament during the stance phase of gait on a treadmill using a combined dual fluoroscopic imaging system (DFIS) and MRI technique. Methods Three-dimensional models of the knee were constructed using magnetic resonance images of 7 healthy human knees. The contours of insertion areas of the superficial MCL (sMCL) and deep MCL (dMCL) on the femur and tibia were constructed using the coronal plane MR images of each knee. Both the sMCL and the dMCL were separated into 3 portions: the anterior, mid, and posterior bundles. The relative elongation of the bundles was calculated using the bundle length at heel strike (or 0% of the stance phase) as a reference. Results The lengths of the anterior bundles were positively correlated with the knee flexion angle. The mid-bundles of the sMCL and dMCL were found to function similarly in trend with the anterior bundles during the stance phase of the gait and their lengths had weak correlations with the knee flexion angles. The elongations of the posterior bundles of sMCL and dMCL were peaked at mid-stance and terminal extension/pre-swing stance phase. The lengths of the posterior bundles were negatively correlated with the knee flexion during the stance phase. Conclusion The data of this study demonstrated that the anterior and posterior bundles of the sMCL and dMCL have a reciprocal function during the stance phase of gait. This data provide insight into the function of the MCL and a normal reference for the study of physiology and pathology of the MCL. The data may be useful in designing reconstruction techniques to better reproduce the native biomechanical behavior of the MCL. Level of evidence IV. PMID:21153541

Liu, Fang; Gadikota, Hemanth R.; Kozanek, Michal; Hosseini, Ali; Yue, Bing; Gill, Thomas J.; Rubash, Harry E.; Li, Guoan

2011-01-01

43

Single stance stability and proprioceptive control in older adults living at home: gender and age differences.  

PubMed

In developed countries, falls in older people represent a rising problem. As effective prevention should start before the risk becomes evident, an early predictor is needed. Single stance instability would appear as a major risk factor. Aims of the study were to describe single stance stability, its sensory components, and their correlation with age and gender. A random sample of 597 older adults (319 men, 278 women) living at home, aged 65-84, was studied. Stability tests were performed with an electronic postural station. The single stance test showed the impairment of single stance stability in older individuals (75-84?yrs). The significant decline of stability in the older subjects may be explained by the impairment of proprioceptive control together with the decrease in compensatory visual stabilization and emergency responses. Younger subjects (65-74?yrs) exhibited better, but still inadequate, proprioceptive control with compensatory visual stabilization. Gender differences appeared in older subjects: women were significantly less stable than men. The measurement of the sensory components of single stance stability could aid in the early detection of a decay in antigravity movements many years before the risk of falling becomes evident. Adequate proprioceptive control could mitigate the effects of all other risks of falling. PMID:23984068

Riva, Dario; Mamo, Carlo; Fanì, Mara; Saccavino, Patrizia; Rocca, Flavio; Momenté, Manuel; Fratta, Marianna

2013-01-01

44

Single Stance Stability and Proprioceptive Control in Older Adults Living at Home: Gender and Age Differences  

PubMed Central

In developed countries, falls in older people represent a rising problem. As effective prevention should start before the risk becomes evident, an early predictor is needed. Single stance instability would appear as a major risk factor. Aims of the study were to describe single stance stability, its sensory components, and their correlation with age and gender. A random sample of 597 older adults (319 men, 278 women) living at home, aged 65–84, was studied. Stability tests were performed with an electronic postural station. The single stance test showed the impairment of single stance stability in older individuals (75–84?yrs). The significant decline of stability in the older subjects may be explained by the impairment of proprioceptive control together with the decrease in compensatory visual stabilization and emergency responses. Younger subjects (65–74?yrs) exhibited better, but still inadequate, proprioceptive control with compensatory visual stabilization. Gender differences appeared in older subjects: women were significantly less stable than men. The measurement of the sensory components of single stance stability could aid in the early detection of a decay in antigravity movements many years before the risk of falling becomes evident. Adequate proprioceptive control could mitigate the effects of all other risks of falling. PMID:23984068

Riva, Dario; Mamo, Carlo; Fani, Mara; Saccavino, Patrizia; Rocca, Flavio; Momente, Manuel; Fratta, Marianna

2013-01-01

45

Double-leg stance and dynamic balance in individuals with functional ankle instability.  

PubMed

To investigate whether double-leg stance could reveal balance deficits in subjects with functional ankle instability (FAI) and whether such an assessment of static balance would be correlated with measures of dynamic instability, 16 individuals with FAI and 16 healthy controls participated in this study. Static postural control was tested using double-leg stance (either with the eyes open (EO) or closed (EC)) on a dual-plate force platform. Dynamic balance was evaluated using the Multiple Hop Test (MHT) and a weight-shifting task. FAI subjects were significantly less stable in the anteroposterior direction during double-leg stance (as assessed by velocity of centre of pressure, VCP), both for the EO and EC condition. In the mediolateral direction the VCP values were also higher in FAI, but significance was only found for the EC condition (p=.02). FAI subjects made significantly more balance errors compared to healthy controls (p<.001) on both the affected and less affected leg during MHT. There were no significant differences between FAI and healthy subjects during the weight-shifting task. No relationship was found between double-leg stance and MHT measures (all correlations (rs) less than .30). This study suggests that static postural control during double-leg stance is impaired in FAI subjects. Although dynamic balance during MHT is also affected, no significant relationship was found between static and dynamic measurements, which indicate that they are most probably related to different aspects of postural control. PMID:23810093

Groters, S; Groen, B E; van Cingel, R; Duysens, J

2013-09-01

46

Contribution of calf muscle-tendon properties to single-leg stance ability in the absence of visual feedback in relation to ageing.  

PubMed

We tested the hypothesis that the importance of calf muscle-tendon properties for maintaining balance during single-leg stance increases in the absence of visual feedback. Trial duration, centre of pressure displacement normalized for trial duration (nD), electromyographic (EMG) activity of the main ankle plantarflexors and dorsiflexors, and ground reaction forces (F(P)), were measured in 20 younger (aged 18+/-1 years; mean+/-S.E.M.) and 28 older (aged 68+/-1 years) healthy participants during single-leg stance in eyes-open (EO) and eyes-closed (EC) conditions. Plantarflexor muscle strength, activation capacity and tendon stiffness were assessed by dynamometry, electrical stimulation and ultrasonography, respectively. Muscle-tendon characteristics in the older participants were up to 55% (P<0.0001) lower compared with their younger counterparts. Trial duration, F(P), nD and EMG changed in EC compared with EO by 21% and up to approximately 4.6 times (P<0.01) in the two population groups. Multiple linear regression with age and the three muscle-tendon properties showed a substantial increment in EC compared to EO for trial duration (R(2)=0.86 versus R(2)=0.72), but a similarity for nD (R(2)=0.36 versus R(2)=0.33). These results suggest that factors other than the ones that we examined become important when steadiness rather than stance duration is the object of single-leg stance in the absence of vision. PMID:17129729

Onambélé, Gladys L; Narici, Marco V; Rejc, Enrico; Maganaris, Constantinos N

2007-09-01

47

Movement strategies and sensory reweighting in tandem stance: differences between trained tightrope walkers and untrained subjects.  

PubMed

Does skill with a difficult task, such as tightrope walking, lead to improved balance through altered movement strategies or through altered weighting of sensory inputs? We approached this question by comparing tandem stance (TS) data between seven tightrope walkers and 12 untrained control subjects collected under different sensory conditions. All subjects performed four TS tasks with eyes open or closed, on a normal firm or foam surface (EON, ECN, EOF, ECF); tightrope walkers were also tested on a tightrope (EOR). Head, upper trunk and pelvis angular velocities were measured with gyroscopes in pitch and roll. Power spectral densities (PSDs) ratios, and transfer function gains (TFG) between these body segments were calculated. Center of mass (CoM) excursions and its virtual time to contact a virtual base of support boundary (VTVBS) were also estimated. Gain nonlinearities, in the form of decreased trunk to head and trunk to pelvis PSD ratios and TFGs, were present with increasing sensory task difficulty for both groups. PSD ratios and TFGs were less in trained subjects, though, in absolute terms, trained subjects moved their head, trunk, pelvis and CoM faster than controls, and had decreased VTVBS. Head roll amplitudes were unchanged with task or training, except above 3Hz. CoM amplitude deviations were not less for trained subjects. For the trained subjects, EOR measures were similar to those of ECF. Training standing on a tightrope induces a velocity modification of the same TS movement strategy used by untrained controls. More time is spent exploring the limits of the base of support with an increased use of fast trunk movements to control balance. Our evidence indicates an increased reliance on neck and pelvis proprioceptive inputs. The similarity of TS on foam to that on the tightrope suggests that the foam tasks are useful for effective training of tightrope walking. PMID:24090964

Honegger, F; Tielkens, R J M; Allum, J H J

2013-12-19

48

Leaning-Based Travel Interfaces Revisited: Frontal versus Sidewise Stances for Flying in 3D Virtual Spaces  

E-print Network

revisit the design of leaning-based travel interfaces and propose a design space to categorize existing-centered design. Keywords Leaning-based travel interface; Stance; Navigation; 3D virtual spaces. 1. INTRODUCTIONLeaning-Based Travel Interfaces Revisited: Frontal versus Sidewise Stances for Flying in 3D Virtual

Lindeman, Robert W.

49

Howard Pattee's theoretical biology — a radical epistemological stance to approach life, evolution and complexity  

Microsoft Academic Search

This paper offers a short review of Pattee's main contributions to science and philosophy. With no intention of being exhaustive, an account of Pattee's work is presented which discusses some of his ideas and their reception. This is done through an analysis centered in what is thought to be his main contribution: the elaboration of an internal epistemic stance to

Jon Umerez

2001-01-01

50

Hamstring Musculotendon Dynamics during Stance and Swing Phases of High Speed Running  

E-print Network

Abstract Introduction--Hamstring strain injuries are common in sports that involve high speed running. It remains uncertain whether the hamstrings are susceptible to injury during late swing phase, when the hamstrings most susceptible to injury during swing phase when compared to stance phase. This information

Wisconsin at Madison, University of

51

Reported Thought as a Stance-Taking Device in Korean Conversation  

ERIC Educational Resources Information Center

Analyses of 34 cases of direct reported thought found in ordinary Korean conversations illustrate a routine practice in the use of reported thought-reenacting a prior thought to demonstrate how the speaker's current stance originated. Often, such thoughts are not simply momentary, isolated thoughts in passing but are consequential thoughts…

Kim, Mary Shin

2014-01-01

52

Reliability and interpretation of single leg stance and maximum voluntary isometric contraction methods of electromyography normalization  

Microsoft Academic Search

Normalization of electromyographic (EMG) amplitudes is necessary in the study of human motion. However, there is a lack of agreement on the most reliable and appropriate normalization method. This study evaluated the reliability of single leg stance (SLS) and maximal voluntary isometric contraction (MVIC) normalization methods and the relationship between these measures for the gluteus maximus (GMax), gluteus medius (GMed),

Marc F. Norcross; J. Troy Blackburn; Benjamin M. Goerger

2010-01-01

53

Reliability and interpretation of single leg stance and maximum voluntary isometric contraction methods of electromyography normalization  

Microsoft Academic Search

Normalization of electromyographic (EMG) amplitudes is necessary in the study of human motion. How- ever, there is a lack of agreement on the most reliable and appropriate normalization method. This study evaluated the reliability of single leg stance (SLS) and maximal voluntary isometric contraction (MVIC) normalization methods and the relationship between these measures for the gluteus maximus (GMax), gluteus medius

Marc F. Norcross; J. Troy Blackburn; Benjamin M. Goerger

2009-01-01

54

Device for the Determination of the Stability of Stance and the Fine Adjustments to Body Equilibrium.  

National Technical Information Service (NTIS)

The stabilograph was used to study the stability of stance of a group of healthy subjects. Based on this study the following parameters were found to be most important: frequency of fluctuation of the center of gravity of the human body in the sagittal an...

A. B. Venediktov, M. I. Tishchenko, Y. V. Terekhov

1972-01-01

55

Vestibular and somatosensory contributions to responses to head and body displacements in stance  

Microsoft Academic Search

The relative contribution of vestibular and somatosensory information to triggering postural responses to external body displacements may depend on the task and on the availability of sensory information in each system. To separate the contribution of vestibular and neck mechanisms to the stabilization of upright stance from that of lower body somatosensory mechanisms, responses to displacements of the head alone

F. B. Horak; C. L. Shupert; V. Dietz; G. Horstmann

1994-01-01

56

Elementary Students' Roles and Epistemic Stances during Document-Based History Lessons  

ERIC Educational Resources Information Center

This article reports on a study that repositioned elementary students in new roles as active, critical participants in historical inquiry--roles that required a more mature epistemic stance. It reports 5th-grade students' responses to instructional methods intended to help them understand the nature of historical knowledge, appreciate the…

Nokes, Jeffery D.

2014-01-01

57

From Tununak to Beaufort: Taking a Critical Inquiry Stance as a First Year Teacher  

ERIC Educational Resources Information Center

In this article, the authors show how two first year teachers a continent apart--Kim in the village of Tununak on the Bering Sea in Alaska and Chris in Beaufort, South Carolina, on the Atlantic Ocean--were able to take inquiry stances on their classrooms. In particular, through analysis of e-mails written in Chris' and Kim's first years of…

Fecho, Bob; Price, Kim; Read, Chris

2004-01-01

58

Muscle activation characteristics of stance balance control in children with spastic cerebral palsy  

Microsoft Academic Search

Two studies were conducted to investigate muscle recruitment of children with spastic cerebral palsy in response to unexpected perturbation of balance in stance. The aim of the studies was to investigate neural and non-neural mechanical contributions to muscle responses differences these children display when maintaining balance. In the first study, muscle responses of children with spastic diplegia were compared to

P. A Burtner; C Qualls; M. H Woollacott

1998-01-01

59

Pedagogical Stances of High School ESL Teachers: "Huelgas" in High School ESL Classrooms  

ERIC Educational Resources Information Center

This article presents a qualitative case study of the pedagogical stances of high school English as a Second Language (ESL) teachers, and the subsequent responses of resistance or conformity by their English Language Learners (ELLs). The participants include three high school ESL teachers and 60 high school ESL students of Mexican origin. Findings…

del Carmen Salazar, Maria

2010-01-01

60

Effect of ageing and vision on limb load asymmetry during quiet stance  

Microsoft Academic Search

Although the identification and characterization of limb load asymmetries during quiet standing has not received much research attention, they may greatly extend our understanding of the upright stance stability control. It seems that the limb load asymmetry factor may serve as a veridical measure of postural stability and thus it can be used for early diagnostic of the age-related decline

Janusz W Blaszczyk; François Prince; Michel Raiche; Réjean Hébert

2000-01-01

61

Faith in academia: integrating students’ faith stance into conceptions of their intellectual development  

Microsoft Academic Search

This paper explores the interaction between religious faith and academic study. It presents findings from a small-scale qualitative study of how first year theology undergraduates at Oxford experienced the relationship between academic study and their faith stance. The findings suggest varied developments in the extent to which students adapted to the learning environment, the strategies they formed in dealing with

Duna Sabri; Christopher Rowland; Jonathan Wyatt; Francesca Stavrakopoulou; Sarita Cargas; Helenann Hartley

2008-01-01

62

Seeing Voices: Assessing Writerly Stance in the NWP Analytic Writing Continuum  

ERIC Educational Resources Information Center

This paper describes the process by which a rubric development team affiliated with the National Writing Project negotiated difficulties and dilemmas concerning an analytic scoring category initially termed Voice and later renamed Stance. Although these labels reference an aspect of student writing that many teachers value, the challenge of…

DiPardo, Anne; Storms, Barbara A.; Selland, Makenzie

2011-01-01

63

Inquiry as Stance: Practitioner Research for the Next Generation. Practitioners Inquiry  

ERIC Educational Resources Information Center

In this long-awaited sequel to "Inside/Outside: Teacher Research and Knowledge", two leaders in the field of practitioner research offer a radically different view of the relationship of knowledge and practice and of the role of practitioners in educational change. In their new book, the authors put forward the notion of inquiry as stance as a…

Cochran-Smith, Marilyn; Lytle, Susan L.

2009-01-01

64

A biomechanical model to determine lumbosacral loads during single stance phase in normal gait  

Microsoft Academic Search

A dynamic biomechanical model to determine loads (joint forces) attained at the lumbosacral joint-centre during the stance phase of normal level walking was developed. The biomechanical model was based on rigid free body-segments; namely, the foot, shank, thigh, pelvis and head, arms and trunk (HAT) segments. In this biomechanical model, the forces and moments acting on the lumbar spine are

B. C. C. Khoo; J. C. H. Goh; K. Bose

1995-01-01

65

Argument or Evidence? Disciplinary Variation in the Use of the Noun "that" Pattern in Stance Construction  

ERIC Educational Resources Information Center

This paper uses a corpus approach to investigate disciplinary variation in the construction of stance using nouns which are followed by "that" and a complement clause, "e.g. the argument that the Justices exhibit strategic behaviour..." Two corpora of theses written in English are examined: approximately 190,000 words in politics/international…

Charles, Maggie

2007-01-01

66

Faith in Academia: Integrating Students' Faith Stance into Conceptions of Their Intellectual Development  

ERIC Educational Resources Information Center

This paper explores the interaction between religious faith and academic study. It presents findings from a small-scale qualitative study of how first year theology undergraduates at Oxford experienced the relationship between academic study and their faith stance. The findings suggest varied developments in the extent to which students adapted to…

Sabri, Duna; Rowland, Christopher; Wyatt, Jonathan; Stavrakopoulou, Francesca; Cargas, Sarita; Hartley, Helenann

2008-01-01

67

Turkish Language Teachers' Stance Taking Movements in the Discourse on Globalization and Language  

ERIC Educational Resources Information Center

This study investigates how Turkish teachers take and give stances in the discourse on globalization and language by using linguistic resources. According to the findings obtained through the discourse analysis of the corpus that consisted of 36 h of recording of the discussion among 4 teachers with 5 to 10 years of teaching experience, the…

Coskun, Ibrahim

2013-01-01

68

A Stance toward Inquiry: An Investigation of Preservice Teachers' Confidence regarding Educational Inquiry  

ERIC Educational Resources Information Center

Research suggests that effective teaching is a significant, if not the most significant, indicator of student success. However, because teaching has become an increasingly challenging profession, school reformers have advocated that educational practices be based on evidence of student learning, suggesting that teachers should develop a stance

Truxaw, Mary P.; Casa, Tutita M.; Adelson, Jill L.

2011-01-01

69

Making Space for Informal Inquiry: Inquiry as Stance in an Online Induction Network  

ERIC Educational Resources Information Center

This study brings the concept of inquiry as stance to bear on current understandings of how inquiry occurs within online networks for teacher induction. The author presents a case study of an online network that allowed 36 new teachers to participate in informal, spontaneous conversations. Genre research is used to examine the on-network,…

Zuidema, Leah A.

2012-01-01

70

Human stability in the erect stance: Alcohol effects and audio-visual perturbations  

Microsoft Academic Search

AimIn this article, we discuss the connection between alcohol and the control strategies carried out by the central nervous system to maintain the erect stance. Audio-visual perturbations were coupled with the consumption of an alcoholic beverage to simulate the possible perturbation affecting people at disco clubs, and the effects measured with a stabilometric platform.

Paolo Bartolomeo Pascolo; Roberto Carniel; Bruno Pinese

2009-01-01

71

The effect of grade and stance on readers’ intertextual and autobiographical responses to literature  

Microsoft Academic Search

This study compares responses written by children in Grades 4, 6, and 8 to three realistic short stories. Results indicated that there was no relationship between the stance taken in a free response and the types of intertextual or autobiographical connections made by the students. Students’ descriptions of the meaningfulness of intertextual and autobiographical connections was related to the grade

Joyce E. Many; Diana D. Anderson

1992-01-01

72

Non-classical computation and the computationalist stance towards the nat-ural and cognitive sciences  

E-print Network

.G.Johnson@kent.ac.uk In recent decades a number of the natural and cognitive sciences have taken what might be termed. Similar computationalist stances have been taken in biology and medicine, though this is less well in natural systems. An example from the cognitive sciences is the way in which the mind delegates certain

Kent, University of

73

Ethical Considerations for Psychologists Taking a Public Stance on Controversial Issues: The Balance Between Personal and Professional Life  

PubMed Central

Previous literature has documented the general issues psychologists often face while balancing their personal and professional lives. The struggle stems from attempting to satisfy the need to maintain a life outside of work while having the professional obligation to follow the American Psychological Association’s (APA’s) Ethical Principles of Psychologists and Code of Conduct (Ethics Code) to prevent their personal lives from interfering with their professional roles and relationships. The present paper analyzes the subject of psychologists taking a public position on controversial public issues. Although the APA Ethics Code does not restrict how psychologists conduct themselves during their personal time, taking a public stance on a controversial issue could potentially strain professional relationships and inadvertently reflect negatively on the profession. The present paper examines ethical issues that a) should be taken into account before psychologists take a public position on a controversial issue, and b) are in conflict with APA’s Ethics Code or current research. PMID:25342876

Haeny, Angela M.

2014-01-01

74

Gender differences exist in neuromuscular control patterns during the pre-contact and early stance phase of an unanticipated side-cut and cross-cut maneuver in 15-18 years old adolescent soccer players.  

PubMed

Non-contact ACL injuries generally occur as the foot contacts the ground during cutting or landing maneuvers and the non-contact ACL injury rate is 2-8 times greater in females compared to males. To provide insight into the gender bias of this injury, this study set out to identify gender differences in the neuromuscular response of the quadriceps, hamstrings and gastrocnemii muscles in elite adolescent soccer players during the pre-contact and early stance phases of an unanticipated side-cut and cross-cut. For the early stance phase of the two maneuvers, females demonstrated greater rectus femoris activity compared to males. Throughout the pre-contact phase of the maneuvers, a rectus femoris activation difference was identified with females having an earlier and more rapid rise in muscle activity as initial ground contact approached. Females demonstrated greater lateral and medial gastrocnemii activity for the pre-contact and early stance phases of the side-cut and greater lateral gastrocnemii activity during early stance of the cross-cut. Timing of hamstring activity also differed between genders prior to foot contact. The differences suggest that the activation patterns observed in females might not be providing adequate joint protection and stability, thereby possibly having a contributing role towards increased non-contact ACL injuries in females. PMID:18938089

Landry, Scott C; McKean, Kelly A; Hubley-Kozey, Cheryl L; Stanish, William D; Deluzio, Kevin J

2009-10-01

75

Human stance control beyond steady state response and inverted pendulum simplification  

Microsoft Academic Search

Systems theory analyses have suggested that human upright stance can be modelled in terms of continuous multi-sensory feedback\\u000a control. So far, these analyses have considered mainly steady-state responses to periodic stimuli and relied on a simplifying\\u000a model of the body’s mechanics in the form of an inverted pendulum. Therefore, they may have ignored relevant aspects of the\\u000a postural behaviour. To

G. Schweigart; T. Mergner

2008-01-01

76

HumanLike Walking using Toes Joint and Straight Stance Leg  

Microsoft Academic Search

This paper describes the use of an actuated toes joint in a humanoid robot to achieve human-like bipedal walking. The robot does not shorten the stance leg, but uses the segment between the ankle joint and the toes joint to over-extend the unloading leg in the double-support phase. Experiments with the servo-based humanoid robot Toni show that this approach leads

Sven Behnke

77

Center of mass control and multi-segment coordination in children during quiet stance  

Microsoft Academic Search

This study aimed to apply an uncontrolled manifold (UCM) approach to investigate how children utilize the variability of multiple\\u000a body segment movement to facilitate the center of mass (COM) control during quiet stance. Three groups of participants were\\u000a included in this study: younger children (YC, mean age 6.3 years), older children (OC, mean age 10.3 years), and young adults\\u000a (YA, mean age

Jianhua Wu; Sandra McKay; Rosa Angulo-Barroso

2009-01-01

78

Taking a stance: child agency across the dimensions of early adolescents' environmental involvement  

Microsoft Academic Search

This article examines the nature of early adolescents' environmental involvement based on a study with 10–13?year?olds. Drawing from literal and metaphorical interviews, a visual survey and visual maps, the study points to the dimensions of environmental involvement: connectedness, engagement with the environment, questioning, belief in capacity, taking a stance and strategic action. Children's agency runs across the dimensions, as children

2008-01-01

79

Variable stiffness actuated prosthetic knee to restore knee buckling during stance: a modeling study.  

PubMed

Most modern intelligent knee prosthesis use dampers to modulate dynamic behavior and prevent excessive knee flexion, but they dissipate energy and do not assist in knee extension. Energy efficient variable stiffness control (VSA) can reduce the energy consumption yet effectively modulate the dynamic behavior and use stored energy during flexion to assist in subsequent extension. A principle design of energy efficient VSA in a prosthetic knee is proposed and analyzed for the specific case of rejection of a disturbed stance phase. The concept is based on the principle that the output stiffness of a spring can be changed without changing the energy stored in the elastic elements of the spring. The usability of this concept to control a prosthetic knee is evaluated using a model. Part of the stance phase of the human leg was modeled by a double pendulum. Specifically the rejection of a common disturbance of transfemoral prosthetic gait, an unlocked knee at heel strike, was evaluated. The ranges of spring stiffnesses were determined such that the angular characteristics of a normal stance phase were preserved, but disturbances could also be rejected. The simulations predicted that energy efficient VSA can be useful for the control of prosthetic knees. PMID:23000012

Wentink, E C; Koopman, H F J M; Stramigioli, S; Rietman, J S; Veltink, P H

2013-06-01

80

Postural Instability Detection: Aging and the Complexity of Spatial-Temporal Distributional Patterns for Virtually Contacting the Stability Boundary in Human Stance  

PubMed Central

Falls among the older population can severely restrict their functional mobility and even cause death. Therefore, it is crucial to understand the mechanisms and conditions that cause falls, for which it is important to develop a predictive model of falls. One critical quantity for postural instability detection and prediction is the instantaneous stability of quiet upright stance based on motion data. However, well-established measures in the field of motor control that quantify overall postural stability using center-of-pressure (COP) or center-of-mass (COM) fluctuations are inadequate predictors of instantaneous stability. For this reason, 2D COP/COM virtual-time-to-contact (VTC) is investigated to detect the postural stability deficits of healthy older people compared to young adults. VTC predicts the temporal safety margin to the functional stability boundary (?=? limits of the region of feasible COP or COM displacement) and, therefore, provides an index of the risk of losing postural stability. The spatial directions with increased instability were also determined using quantities of VTC that have not previously been considered. Further, Lempel-Ziv-Complexity (LZC), a measure suitable for on-line monitoring of stability/instability, was applied to explore the temporal structure or complexity of VTC and the predictability of future postural instability based on previous behavior. These features were examined as a function of age, vision and different load weighting on the legs. The primary findings showed that for old adults the stability boundary was contracted and VTC reduced. Furthermore, the complexity decreased with aging and the direction with highest postural instability also changed in aging compared to the young adults. The findings reveal the sensitivity of the time dependent properties of 2D VTC to the detection of postural instability in aging, availability of visual information and postural stance and potential applicability as a predictive model of postural instability during upright stance. PMID:25295589

Kilby, Melissa C.; Slobounov, Semyon M.; Newell, Karl M.

2014-01-01

81

EFFECT OF LOSS OF BALANCE ON BIOMECHANICS PLATFORM MEASURES OF SWAY: INFLUENCE OF STANCE AND A METHOD FOR ADJUSTMENT  

Microsoft Academic Search

leg stances, the correlations for the area measures ranged from 0.69 to 0.89. The correlations between adjusted and unadjusted velocity measures were 1.W and 0.93 for the double and single leg stances respectively. Although the question ofwhich sway measure is best remains unanswered, this study provides useful data for future research. First, it demonstrates a method for modifying area representations

SAMER S. HASAX; J. LICHTESSTEIK

82

Design and functional evaluation of a quasi-passive compliant stance control knee-ankle-foot orthosis.  

PubMed

In this paper, we present the mechanical design, control algorithm, and functional evaluation of a quasi-passive compliant stance control knee-ankle-foot orthosis. The orthosis implements a spring in parallel with the knee joint during the stance phase of the gait and allows free rotation during the swing phase. The design is inspired by the moment-angle analysis of the knee joint revealing that the knee function approximates that of a linear torsional spring in the stance phase of the gait. Our orthosis aims to restore the natural function of a knee that is impaired by injury, stroke, post-polio, multiple sclerosis, spinal cord injury, patellofemoral pain syndrome, osteoarthritis, and others. Compared with state-of-the-art stance control orthoses, which rigidly lock the knee during the stance phase, the described orthosis intends to provide the natural shock absorption function of the knee in order to reduce compensatory movements both in the affected and unaffected limbs. Preliminary testing on three unimpaired subjects showed that compliant support of the knee provided by the orthosis explained here results in higher gait speed as well as more natural kinematic profiles for the lower extremities when compared with rigid support of the knee provided by an advanced commercial stance control orthosis. PMID:24608684

Shamaei, Kamran; Napolitano, Paul C; Dollar, Aaron M

2014-03-01

83

Developing Inquiry-as-Stance and Repertoires of Practice: Teacher Learning Across Two Settings  

NASA Astrophysics Data System (ADS)

Sixteen science educators joined a science teacher video club for one school year to collaboratively inquire into each other's classroom practice through the use of records of practice including classroom video clips and samples of student work. This group was focused on developing ambitious, equitable science teaching that capitalizes on students' ways of talking and thinking about important science ideas in order to co-construct, test, refine, and revise explanatory models. By analyzing both the teacher-to-teacher interactions taking place in the context of the video club and the on-going classroom teaching practice, this study fills important gaps in our understanding of teacher learning across settings of professional development and classroom practice. This study pursues answers to two groups of guiding questions: (1) How do teachers learn from each other in the context of collaborative inquiry groups, such as a science teacher video club? How do teachers draw upon classroom teaching experiences, re-interpret those experiences, and challenge each other's interpretations and choices made when teaching? (2) How are teachers' professional development experiences connected to and supported by teachers' on-going classroom practice? When the vision of science teaching developed in one context, such as a professional development setting, is different from the vision or teaching developed in another context, such as a local school, how do teachers wrestle with these differences to make choices about instructional practice? Using a sociocultural framework, this study traces the development of inquiry-as-stance as seen in teachers' stance-taking during collegial conversations while also tracing the development of teachers' repertoires of instructional practice. Analysis of discourse during teacher-to-teacher talk as well as during classroom interactions affords insights into the development of an inquiry stance and the evolution of instructional practice at the level of turn-by-turn talk contextualized in real school settings.

Braaten, Melissa L.

84

Stance stability with unilateral and bilateral light touch of an external stationary object.  

PubMed

Unilateral light fingertip touch of a stationary object has a significant stabilizing effect on postural sway during stance. The purpose of this study was to find out if this effect is enhanced by bilateral light touch of parallel stationary objects. The postural sway of 54 healthy subjects was tested in four stance conditions: no touch; unilateral left light touch of the left handle of a walker; unilateral right light touch of the right handle of the same walker; and bilateral light touch of the two handles. During testing, subjects stood blindfolded on two foam pads placed on the left and right force plates of the Tetrax balance system. Testing in each condition lasted 45 s and was executed twice in a random order. As expected, postural sway was significantly reduced by unilateral left or right light fingertip touch. It was significantly further decreased by bilateral light touch. In addition, light touch conditions were associated with a reduction in pressure fluctuations between the heel and forefoot of the same foot as well as those of the contralateral foot, with a concomitant increase in weight shift fluctuations between the two feet. The decrease in postural sway with bilateral light touch suggests cortical modulation of the bilateral touch inputs, with enhancement of the stabilizing response. PMID:16503584

Dickstein, Ruth

2005-12-01

85

Knowing When to Doubt: Developing a Critical Stance When Learning From Others  

PubMed Central

Children may be biased towards accepting information as true, but the fact remains that children are exposed to misinformation from many sources, and mastering the intricacies of doubt is necessary. The current article examines this issue, focusing on understanding developmental changes and consistencies in children’s ability to take a critical stance towards information. Research is reviewed on children’s ability to detect ignorance, inaccuracy, incompetence, deception, and distortion. Particular emphasis is placed on what this research indicates about how children are reasoning about when to trust and when to doubt. The remainder of the article proposes a framework to evaluate preexisting research and encourage further research, closing with a discussion of several other overarching questions that need to be considered in order to develop a model to explain developmental, individual, and situational differences in children’s ability to evaluate information. PMID:22889395

Mills, Candice M.

2013-01-01

86

Government Stance and Internal Diversity of Protest: A Comparative Study of Protest against the War in Iraq in Eight Countries  

ERIC Educational Resources Information Center

This study tackles the question to what extent the composition of protest events is determined by the stance of governments. Established contextual theories do not formulate propositions on how context affects individual protesters. The article engages in empirically testing whether the macro-context affects the internal diversity of the crowds…

Walgrave, Stefaan; Verhulst, Joris

2009-01-01

87

Brazil's Fiscal Stance during 1995-2005: The Effect of Indebtedness on Fiscal Policy Over the Business Cycle  

Microsoft Academic Search

Brazil's fiscal adjustment since the floating of the real in 1999 has been impressive, even in periods of lacklustre growth. This suggests a remarkable fiscal effort to ensure public debt sustainability. To better gauge the magnitude of this adjustment effort, this paper applies the methodology used by the OECD Secretariat to distinguish changes in the fiscal stance that are due

Luiz de Mello; Diego Moccero

2006-01-01

88

Why an Investigative Stance Matters in Intercultural Language Teaching and Learning: An Orientation to Classroom-Based Investigation  

ERIC Educational Resources Information Center

This paper develops the idea that classroom investigation can be an integral part of teaching and learning, an ongoing "stance" that enables us to gather valuable information about teaching and learning that may otherwise go unnoticed. This information can in turn inform how teachers understand and develop intercultural language teaching and…

Crichton, Jonathan

2008-01-01

89

Analysis of the multi-segmental postural movement strategies utilized in bipedal, tandem and one-leg stance as quantified by a principal component decomposition of marker coordinates.  

PubMed

Postural control research describes ankle-, hip-, or multi-joint strategies as mechanisms to control upright posture. The objectives of this study were, first, development of an analysis technique facilitating a direct comparison of the structure of such multi-segment postural movement patterns between subjects; second, comparison of the complexity of postural movements between three stances of different difficulty levels; and third, investigation of between-subject differences in the structure of postural movements and of factors that may contribute to these differences. Twenty-nine subjects completed 100-s trials in bipedal (BP), tandem (TA) and one-leg stance (OL). Their postural movements were recorded using 28 reflective markers distributed over all body segments. These marker coordinates were interpreted as 84-dimensional posture vectors, normalized, concatenated from all subjects, and submitted to a principal component analysis (PCA) to extract principal movement components (PMs). The PMs were characterized by determining their relative contribution to the subject's entire postural movements and the smoothness of their time series. Four, eight, and nine PM were needed to represent 90% of the total variance in BP, TA, and OL, respectively, suggesting that increased task difficulty is associated with increased complexity of the movement structure. Different subjects utilized different combinations of PMs to control their posture. In several PMs, the relative contribution of a PM to a subject's overall postural movements correlated with the smoothness of the PM's time series, suggesting that utilization of specific postural PMs may depend on the subject's ability to control the PM's temporal evolution. PMID:24021753

Federolf, Peter; Roos, Lilian; Nigg, Benno M

2013-10-18

90

Kinematics and Kinetics of Squat and Deadlift Exercises with Varying Stance Widths  

NASA Technical Reports Server (NTRS)

The primary motion of squat and deadlift exercise involves flexion and extension of the hips, knees, and ankles, but each exercise can be performed with variations in stance width. These variations may result in differing kinematics and ground reaction forces (GRF), which may in turn affect joint loading. PURPOSE: The purpose of this investigation was to compare ankle, knee, and hip kinematics and kinetics of normal squat (NS), wide-stance squat (WS), normal deadlift (ND), and sumo deadlift (SD). We hypothesized that hip joint kinematics and work at each joint would differ between exercise variations. METHODS: Six subjects (3 m/3 f; 70.0 plus or minus 13.7 kg; 168 plus or minus 9.9 cm) performed each lift in normal gravity on the ground-based version of the Advanced Resistive Exercise Device (ARED) used on the International Space Station. The ARED provided resistance with a combination vacuum tube/flywheel mechanism designed to replicate the gravitational and inertial forces of free weights. Subjects completed each lift with their 10-repetition maximum load. Kinematic data were collected at 250 Hz by a 12-camera motion-capture system (Smart-D, BTS Bioengineering, Milan, Italy), and GRF data were collected at 1000 Hz with independent force platforms for each leg (Model 9261, Kistler Instruments AG, Winterhur, Switzerland). All data were captured simultaneously on a single workstation. The right leg of a single lift for each motion was analyzed. Modeling software (OpenSim 2.2.0, Simbios, Palo Alto, CA) determined joint kinematics and net positive and negative work at each lower extremity joint. Total work was found as the sum of work across all joints and was normalized by system mass. Effect sizes and their 95% confidence intervals were computed between conditions. RESULTS: Peak GRF were similar for each lift. There were no differences between conditions in hip flexion range of motion (ROM). For hip adduction ROM, there were no differences between the NS, WS, and SD. However, hip adduction ROM was greater during the NS and SD than during the ND. Hip rotation ROM was greater during the WS than during the NS and SD, and was greater during the SD than during the ND. For knee and ankle flexion ROM, the ND, WS, and SD were not different, but ROM was greater during the NS than the ND and greater during the WS than the SD. Total eccentric work was greater during the WS than the SD. Otherwise, there were no differences in eccentric or concentric work between conditions. CONCLUSIONS: Although squat and deadlift exercises consist of similar motions, there are kinematic differences between them that depend on stance width. Total eccentric and concentric work are similar for different lifts, but differing kinematics may require activation of different musculature for each variation. With respect to each condition, in the ND the ROM of each joint tended to be less, and the WS tended to trade knee motion for hip motion. PRACTICAL APPLICATIONS: Knowledge of differences in kinematics and kinetics between different squat and deadlift variations is important for coaches and rehabilitation personnel to understand when prescribing exercise. Our results suggest that each variation of the squat and deadlift should be considered a separate exercise that may induce different long-term training effects.

DeWitt, John K.; Fincke, Renita S.; Logan, Rachel L.

2011-01-01

91

Slip-related muscle activation patterns in the stance leg during walking.  

PubMed

Falls precipitated by slipping are a serious public health concern especially in the elderly. Muscular responses generated during slipping have not been investigated during gait on contaminated floors. This study compared slip-related muscular responses (reactive and proactive) in young and older adults and examined if characteristics of muscular activation patterns during normal gait impact slip severity on contaminated floors. Electromyographic recordings were made from the major shank and thigh muscles in the stance leg of 11 young and nine older adults. Three experimental conditions were included: (1) known dry floors (baseline), (2) unexpected contaminated floor, (3) alert dry (subjects uncertain of the floor's contaminant condition). Muscular responses to unexpected slips, similar in both age groups, included the activation of the Medial Hamstring (approximately 175 ms) followed by the onset of the Vastus Lateralis (approximately 240 ms). The power and duration of responses were scaled to slip severity. The Vastus Lateralis latency was delayed in severe slips. When experiencing a severe slip, young adults demonstrated a longer, more powerful response compared to older adults. Subjects who normally walk with greater ankle muscle co-contraction were predisposed to experience less severe slips when encountering an unexpected slippery floor. Finally, anticipation of a slippery surface resulted in more powerful muscular activity and muscle co-contraction at the ankle and knee compared to baseline gait, as well as earlier onsets and longer durations in the posterior muscles' activation. These findings may provide a greater understanding of the higher incidence of falls in the elderly. PMID:16876417

Chambers, April J; Cham, Rakié

2007-04-01

92

The role of knee positioning and range-of-motion on the closed-stance forehand tennis swing  

Microsoft Academic Search

This paper discusses the role of knee positioning and range-of- motion on the closed-stance forehand tennis swing. The analyses of tennis swing mechanics were performed using a computer model comprised of a full-body model of a human and an iner- tial model of a racket. The model was driven by subject fore- hand swings (16 female college-level subjects) recorded with

Steven M. Nesbit; Monika Serrano; Mike Elzinga

2008-01-01

93

The effect of prosthetic feedback on the strategies and synergies used by vestibular loss subjects to control stance  

PubMed Central

Background This study investigated changes in stance movement strategies and muscle synergies when bilateral peripheral vestibular loss (BVL) subjects are provided feedback of pelvis sway angle. Methods Six BVL (all male) and 7 age-matched male healthy control (HC) subjects performed 3 stance tasks: standing feet hip width apart, eyes closed, on a firm and foam surface, and eyes open on foam. Pelvis and upper trunk movements were recorded in the roll and pitch planes. Surface EMG was recorded from pairs of antagonistic muscles at the lower leg, trunk and upper arm. Subjects were first assessed without feedback. Then, they received training with vibrotactile, auditory, and fall-warning visual feedback during stance tasks before being reassessed with feedback. Results Feedback reduced pelvis sway angle displacements to values of HCs for all tasks. Movement strategies were reduced in amplitude but not otherwise changed by feedback. These strategies were not different from those of HCs before or after use of feedback. Low frequency motion was in-phase and high frequency motion anti-phasic. Feedback reduced amplitudes of EMG, activity ratios (synergies) of antagonistic muscle pairs and slightly reduced baseline muscle activity. Conclusions This is the first study demonstrating how vestibular loss subjects achieve a reduction of sway during stance with prosthetic feedback. Unchanged movement strategies with reduced amplitudes are achieved with improved antagonistic muscle synergies. This study suggests that both body movement and muscle measures could be explored when choosing feedback variables, feedback location, and patient groups for prosthetic devices which reduce sway of those with a tendency to fall. PMID:24354579

2013-01-01

94

Japan's Policy Stance on East Asian Neo-Regionalism: From Being a “Reluctant”, to Becoming a “Proactive” State  

Microsoft Academic Search

This article is a theoretically grounded empirical contribution aimed at shedding light on Japan's policy stance on East Asian neo-regionalism. It aims to examine the recent region-building process in East Asia. The dynamics in East Asia suggest that regional institutionalization, brought about by norm diffusion based on the idea of neo-regionalism, is likely to follow a progressive and evolutionary trajectory

Chang-Gun Park

2006-01-01

95

Postural stability of canoeing and kayaking young male athletes during quiet stance.  

PubMed

We studied the postural stability of 23 canoeing and kayaking young athletes and 15 healthy untrained age matched subjects during quiet and sensory conflicted stance (standing on stable and foam support with open and closed eyes). We measured with a force platform the center of pressure excursions and applied mean sway amplitude (MA), mean sway velocity (SV) and their Romberg ratios, and sway dispersion index to evaluate standing balance. During standing with eyes open, the athletes in comparison to non-athletes showed in sagittal and frontal plane greater MA and SV when the support was stable and smaller MA and SV when it was unstable. During standing with eyes closed, there were no differences between groups when the support was stable, however, the athletes sway faster and have smaller MA than controls while standing on the foam support. During standing on stable support, Romberg ratios for MA and SV revealed that unlike non-athletes the athletes' MA and SV were vision independent. However, while standing on unstable support the athletes' MA and SV became vision dependent and even greater for the medio-lateral sway. Canoeists' SV vision dependency in both planes was greater than for other groups. These results are in line with our hypothesis that young kayaking and canoeing athletes have a different from non-athletes model of sensory integration due to their specific sporting activity. One possible mechanism of this model may be a subtle re-adaptation deficit after disembarking to stable ground with diminished sensitivity of vision and vestibular apparatus. PMID:21909987

Stambolieva, Katerina; Diafas, Vassilis; Bachev, Vichren; Christova, Lilia; Gatev, Plamen

2012-05-01

96

A dynamic cadaver model of the stance phase of gait: performance characteristics and kinetic validation.  

PubMed

OBJECTIVE: This study was undertaken to evaluate the performance of a new dynamic laboratory model of the stance phase of gait. DESIGN: Five cadaver feet were repetitively tested in the apparatus. BACKGROUND: Typical biomechanical investigations of cadaver feet simply place a static load on the tibia. The present system was designed to better simulate the changing in-vivo loading environment of the foot and ankle during gait. METHODS: The device mimics the behavior of the tibia, foot, and ankle from heel-strike to toe-off by reproducing the physiologic actions of five extrinsic foot muscles and physiologic motion at the proximal tibia. To verify its utility, cadaver gait simulations were conducted while measuring applied muscle forces, ground reaction forces, and plantar pressures. RESULTS: Dynamic muscle forces were consistently delivered to within 10% of pre-programmed values. Dynamic measurements of ground reaction forces and plantar pressure were similar to those measured in healthy human subjects. Peak vertical (y), foreaft (x) and medio-lateral (z) forces were 110, 18, and 4% of body weight respectively. Compressive force in the tibial shaft reached 410% of body weight. RELEVANCE: Cadaver studies have greatly enhanced our understanding of normal and pathologic foot function, but are often limited by over-simplified loading conditions. The apparatus presented here accurately reproduces the in-vivo loading environment and provides a powerful investigational tool for the study of foot and ankle function. With this device, musculoskeletal structures can be examined in detail under biomechanical conditions similar to those they experience in life. PMID:11415817

Sharkey, Neil A.; Hamel, Andrew J.

1998-09-01

97

Estimation of Quasi-Stiffness of the Human Hip in the Stance Phase of Walking  

PubMed Central

This work presents a framework for selection of subject-specific quasi-stiffness of hip orthoses and exoskeletons, and other devices that are intended to emulate the biological performance of this joint during walking. The hip joint exhibits linear moment-angular excursion behavior in both the extension and flexion stages of the resilient loading-unloading phase that consists of terminal stance and initial swing phases. Here, we establish statistical models that can closely estimate the slope of linear fits to the moment-angle graph of the hip in this phase, termed as the quasi-stiffness of the hip. Employing an inverse dynamics analysis, we identify a series of parameters that can capture the nearly linear hip quasi-stiffnesses in the resilient loading phase. We then employ regression analysis on experimental moment-angle data of 216 gait trials across 26 human adults walking over a wide range of gait speeds (0.75–2.63 m/s) to obtain a set of general-form statistical models that estimate the hip quasi-stiffnesses using body weight and height, gait speed, and hip excursion. We show that the general-form models can closely estimate the hip quasi-stiffness in the extension (R2?=?92%) and flexion portions (R2?=?89%) of the resilient loading phase of the gait. We further simplify the general-form models and present a set of stature-based models that can estimate the hip quasi-stiffness for the preferred gait speed using only body weight and height with an average error of 27% for the extension stage and 37% for the flexion stage. PMID:24349136

Shamaei, Kamran; Sawicki, Gregory S.; Dollar, Aaron M.

2013-01-01

98

Using Argument-Driven Inquiry to enhance students' argument sophistication when supporting a stance in the context of Socioscientific Issues  

NASA Astrophysics Data System (ADS)

This quasi-experimental study assesses the extent to which the Argument-Driven Inquiry (ADI) instructional model enhances undergraduate students' abilities to generate quality arguments supporting their stance in the context of a Socioscientific Issue (SSI) as compared to students experiencing a traditional style of instruction. Enhancing the quality of undergraduate students' arguments in the context of SSI can serve as an indirect measure of their scientific literacy and their ability to make sound decisions on issues that are inherently scientific but also involve social implications. Data collected in this study suggest that the undergraduate students experiencing the ADI instruction more readily provide rationales in their arguments supporting their decisions regarding two SSI-tasks as compared to a group of undergraduate students experiencing traditional instruction. This improvement in argument quality and gain in scientific literacy was achieved despite the overall lower SSI related content knowledge of the ADI students. Furthermore, the gap between the argument quality of those students with high versus low SSI related content knowledge was closed within the ADI group, while the same gap persisted post-intervention within the traditional instruction students. The role of students' epistemological sophistication was also investigated, which showed that neither instructional strategy was effective at shifting students' epistemological sophistication toward an evaluativist stance. However, the multiplists within the ADI group were able to significantly increase the sophistication of their arguments whereas the traditional students were not. There were no differences between the quality of arguments generated by the evaluativist students with either the treatment or comparison groups. Finally, the nature of the justifications used by the students revealed that the students (both comparison and treatment groups) did not invoke science-based justifications when supporting their stance, despite students' self-reports that scientific content knowledge accounted for the greatest influence on their stance, related to the SSI tasks. The results of this study suggest that the scientific habits of mind the students learned in the context of ADI investigations are transferred to the novel SSI contexts. Implications for the use of argument-based instructional models to enhance the generation of socioscientific arguments and to promote the development of scientific literacy are also discussed.

Grooms, Jonathon A.

99

Intra-articular Contact Stress Distributions at the Ankle throughout Stance Phase - Patient-Specific Finite Element Analysis as a Metric of Degeneration Propensity  

PubMed Central

A contact finite element (FE) formulation is introduced, amenable to patient-specific analysis of cumulative cartilage mechano-stimulus attributable to habitual functional activity. CT scans of individual human ankles are segmented to delineate bony margins. Each bone surface is projected outward to create a second surface, and the intervening volume is then meshed with continuum hexahedral elements. The tibia is positioned relative to the talus into a weight-bearing apposition. The articular members are first engaged under light preload, then plantar-/dorsi-flexion kinematics and resultant loadings are input for serial FE solutions at 13 instants of the stance phase of level walking gait. Cartilage stress histories are post-processed to recover distributions of cumulative stress-time mechano-stimulus, a metric of degeneration propensity. Consistency in computed contact stress exposures presented for seven intact ankles stood in contrast to the higher magnitude and more focal exposures in an incongruously reduced tibial plafond fracture. This analytical procedure provides patient-specific estimates of degeneration propensity due to various mechanical abnormalities, and it provides a platform from which the mechanical efficacy of alternative surgical interventions can be estimated. PMID:16520960

Anderson, Donald D.; Goldsworthy, Jane K.; Shivanna, Kiran; Grosland, Nicole M.; Pedersen, Douglas R.; Thomas, Thaddeus P.; Tochigi, Yuki; Marsh, J.Lawrence; Brown, Thomas D.

2008-01-01

100

Comparison of the effect of selected muscle groups fatigue on postural control during bipedal stance in healthy young women  

PubMed Central

Background: The maintenance of balance is an essential requirement for the performance of daily tasks and sporting activities and muscular fatigue is a factor to impair postural control, so this study was done to compare the effect of selected muscle groups fatigue on postural control during bipedal stance in healthy subjects. Materials and Methods: Fifteen healthy female students (24.3 ± 2.6 years) completed three testing session with a break period of at least 2 days. During each session, postural control was assessed during two 30-s trials of bipedal stance with eyes close before and after the fatigue protocol. Fatigue protocols were performed by 60% of their unfatigued Maximum Voluntary Contraction of unilateral ankle plantar flexors, bilateral lumbar extensors and bilateral neck extensors. One of the three fatigue protocols was performed on each session. Results: The result showed that fatigue had a significant effect on COP velocity and it increase COP velocity but there was not found any difference in postural sway between muscle groups. Conclusion: Localized muscle fatigue caused deficits in postural control regardless of the location of fatigue. Authors suggest the possibility of the contributions of central mechanisms to postural deficits due to fatigue and it seems that difference was not between muscle groups due to central fatigue. PMID:24403706

Shirazi, Zahra Rojhani; Jahromi, Fatemeh Nikhalat

2013-01-01

101

Talk and Conceptual Change at Work: Adequate Representation and Epistemic Stance in a Comparative Analysis of Statistical Consulting and Teacher Workgroups  

ERIC Educational Resources Information Center

In this article we ask how concepts that organize work in two professional disciplines change during moments of consultation, which represent concerted efforts by participants to work differently now and in the future. Our analysis compares structures of talk, the adequacy of representations of practice, and epistemic and moral stances deployed…

Hall, Rogers; Horn, Ilana Seidel

2012-01-01

102

Balance in single-limb stance in healthy subjects – reliability of testing procedure and the effect of short-duration sub-maximal cycling  

Microsoft Academic Search

BACKGROUND: To assess balance in single-limb stance, center of pressure movements can be registered by stabilometry with force platforms. This can be used for evaluation of injuries to the lower extremities. It is important to ensure that the assessment tools we use in the clinical setting and in research have minimal measurement error. Previous studies have shown that the ability

Eva Ageberg; David Roberts; Eva Holmström; Thomas Fridén

2003-01-01

103

Abstract--In this paper, we present the design of a novel quasi-passive stance-control orthosis that implements a natural  

E-print Network

, and others [3-6]. These musculoskeletal disorders often result in lower limb dysfunctions such as impaired with paresis and paralysis in the lower limb muscles. Current SCOs rigidly stabilize the knee in the stance]. Moreover, users have demonstrated reduced energy expenditure and gait asymmetry [10, 16]. Previous research

Dollar, Aaron M.

104

"The Mystery . . .": A Corpus-based Study of the Use of Nouns To Construct Stance in Theses from Two Contrasting Disciplines.  

ERIC Educational Resources Information Center

Investigates the construction of stance through nouns in two corpora of theses--200,000 words in politics and international relations and 300,000 words in materials science. Examines nouns that are preceded by sentence initial deicitic "This" and that serve to encapsulate earlier prepositions. (Author/VWL)

Charles, Maggie

2003-01-01

105

Issues in Discipline-Based Art Education: Strengthening the Stance, Extending the Horizons. Seminar Proceedings (Cincinnati, Ohio, May 21-24, 1987).  

ERIC Educational Resources Information Center

The rationale for this seminar was to strengthen the discipline-based art education (DBAE) stance and extend its horizons. The format of the proceedings featured a speaker followed by a respondent and group discussions on each of the four issues addressed by the seminar. Dennie Wolf explained how current research in child development and cognitive…

Getty Center for Education in the Arts, Los Angeles, CA.

106

The effects of dual-channel functional electrical stimulation on stance phase sagittal kinematics in patients with hemiparesis.  

PubMed

Sixteen subjects (aged 54.2 ± 14.1 years) with hemiparesis (7.9 ± 7.1 years since diagnosis) demonstrating a foot-drop and hamstrings muscle weakness were fitted with a dual-channel functional electrical stimulation (FES) system activating the dorsiflexors and hamstrings muscles. Measurements of gait performance were collected after a conditioning period of 6 weeks, during which the subjects used the system throughout the day. Gait was assessed with and without the dual-channel FES system, as well as with peroneal stimulation alone. Outcomes included lower limb kinematics and the step length taken with the non-paretic leg. Results with the dual-channel FES indicate that in the subgroup of subjects who demonstrated reduced hip extension but no knee hyperextension (n = 9), hamstrings FES increased hip extension during terminal stance without affecting the knee. Similarly, in the subgroup of subjects who demonstrated knee hyperextension but no limitation in hip extension (n = 7), FES restrained knee hyperextension without having an impact on hip movement. Additionally, step length was increased in all subjects. The peroneal FES had a positive effect only on the ankle. The results suggest that dual-channel FES for the dorsiflexors and hamstrings muscles may affect lower limb control beyond that which can be attributed to peroneal stimulation alone. PMID:23231828

Springer, Shmuel; Vatine, Jean-Jacques; Wolf, Alon; Laufer, Yocheved

2013-04-01

107

Effect of arch type and Body Mass Index on plantar pressure distribution during stance phase of gait.  

PubMed

Several factors have been associated with the presence of abnormally high plantar foot pressure including: (i) increased body weight, (ii) foot structure and (iii) walking strategy. It is predicted that the biomechanics of the foot is influenced by the structure of the foot, primarily the Medial Longitudinal Arch. The objective of this study was to examine if Body Mass Index and the foot arch have a direct effect on dynamic peak plantar pressure for healthy subjects. Following a clinical lower limb examination, the Tekscan HR mat was utilised for this study, plantar pressure was profiled at specific events during stance phase of gait including heel strike, midstance and toe off. Results indicated to the preferable normal arch as this produced a low plantar pressure distribution in all cases. The 2nd and 3rd metatarsal head region recorded the highest pressure for all arch types during dynamic analysis. The lowest pressure for the normal and overweight BMI was at toe-off. While the obese BMI group showed highest pressure during toe-off. The obese BMI flat arch subcategory indicated to functional ambulation differences. Future work involves comparing this healthy database to a demographically matched diabetic group. PMID:25088082

O'Brien, Davida Louise; Tyndyk, Magdalena

2014-01-01

108

The Correlation between the Muscle Activity and Joint Angle of the Lower Extremity According to the Changes in Stance Width during a Lifting Task  

PubMed Central

[Purpose] This study examined the correlation between the muscle activities and joint angle of the hip and knee according to the changes in stance width during a lifting task. [Subjects and Methods] The subjects of this study were 15 healthy students. A three-dimensional motion analyzer (SMART-E, BTS, Italy) was used to measure the joint angles of hip and knee during lifting. An 8-channel electromyograph (8-EMG) (Pocket EMG, BTS, Italy) was used to measure muscle activities of the erector spinae, gluteus maximus, rectus femoris, and tibialis anterior during lifting. The collected data were analyzed using the Pearson-test and SPSS 18.0. [Result] The muscle activity of the tibialis anterior was significantly decreased by increasing the stance width (r= ?0.285). Muscle activity of the erector spinae was significantly decreased by increasing the knee angle (r= ?0.444). The muscle activity of the gluteus maximus was significantly increased by increasing the muscle activity of the tibialis anterior (r= 0.295). [Conclusion] Efficient lifting is possible when stance width and knee flexion are increased, which results in reduced muscle activity of the tibialis anterior and the erector spinae. Lifting is facilitated when the muscle activities of the gluteus maximus and tibialis anterior are correlated. PMID:24259908

Yoon, Jung-Gyu

2013-01-01

109

Time?  

NASA Astrophysics Data System (ADS)

The concept of time in the `clockwork' Newtonian world was irrelevant; and has generally been ignored until recently by several generations of physicists since the implementation of quantum mechanics. We will set aside the utility of time as a property relating to physical calculations of events relating to a metrics line element or as an aspect of the transformation of a particles motion/interaction in a coordinate system or in relation to thermodynamics etc., i.e. we will discard all the usual uses of time as a concept used to circularly define physical parameters in terms of other physical parameters; concentrating instead on time as an aspect of the fundamental cosmic topology of our virtual reality especially as it inseparably relates to the nature and role of the observer in natural science.

Amoroso, Richard L.

2013-09-01

110

Two Different Protocols for Knee Joint Motion Analyses in the Stance Phase of Gait: Correlation of the Rigid Marker Set and the Point Cluster Technique  

PubMed Central

Objective. There are no reports comparing the protocols provided by rigid marker set (RMS) and point cluster technique (PCT), which are similar in terms of estimating anatomical landmarks based on markers attached to a segment. The purpose of this study was to clarify the correlation of the two different protocols, which are protocols for knee motion in gait, and identify whether measurement errors arose at particular periods during the stance phase. Methods. The study subjects were 10 healthy adults. All estimated anatomical landmarks were which their positions, calculated by each protocol of the PCT and RMS, were compared using Pearson's product correlation coefficients. To examine the reliability of the angle changes of the knee joint measured by RMS and the PCT, the coefficient of multiple correlations (CMCs) was used. Results. Although the estimates of the anatomical landmarks showed high correlations of >0.90 (P < 0.01) for the Y- and Z-coordinates, the correlations were low for the X-coordinates at all anatomical landmarks. The CMC was 0.94 for flexion/extension, 0.74 for abduction/adduction, and 0.71 for external/internal rotation. Conclusion. Flexion/extension and abduction/adduction of the knee by two different protocols had comparatively little error and good reliability after 30% of the stance phase. PMID:23029618

Fukaya, Takashi; Mutsuzaki, Hirotaka; Ida, Hirofumi; Wadano, Yasuyoshi

2012-01-01

111

Philip Morris's website and television commercials use new language to mislead the public into believing it has changed its stance on smoking and disease  

PubMed Central

Objectives This paper analyses Philip Morris's evolving website and the legal strategies employed in its creation and dissemination. Methods Internal tobacco documents were searched and examined and their substance verified and triangulated using media accounts, legal and public health research papers, and visits to Philip Morris's website. Various drafts of website language, as well as informal discussion of the website's creation, were located in internal Philip Morris documents. I compared website statements pertaining to Philip Morris's stance on cigarette smoking and disease with statements made in tobacco trials. Results Philip Morris created and disseminated its website's message that it agreed that smoking causes disease and is addictive in an effort to sway public opinion, while maintaining in a litigation setting its former position that it cannot be proved that smoking causes disease or is addictive. Conclusions Philip Morris has not changed its position on smoking and health or addiction in the one arena where it has the most to lose—in the courtroom, under oath. PMID:18048599

Friedman, Lissy C

2007-01-01

112

Muscular contractions and their effect on the vertical ground reaction force during quiet stance--Part II: Mathematical model.  

PubMed

A one-dimensional lumped-parameters mathematical model of the standing human was developed to specifically investigate how the muscular activity and the cardiovascular forces originated by the heart movement and the blood ejection in the ascending aorta affect the ground reaction force in the head-to-toes direction. The forces produced by the cardiovascular activity were modeled by a time-varying force actuator connected to the torso whose characteristics were obtained from the literature. The muscles identified as active during Part I of this work, mainly the erector spinae and oblique abdominal muscles, were modeled as a single force actuator acting with equal and opposite force between the pelvis and the thoracic spine. The force versus time data were obtained from the electromyographic signals obtained in Part I. Although the model of the human body used in this investigation was simple, the results of the simulations clearly showed that the cardiovascular forces alone are not sufficient for generating the large negative (i.e., upward) peak observed in the vertical ground reaction force. The peaks were mainly the result of a very modest muscular contraction of the spinal muscles. The simulations offer further evidence to support the hypothesis that trunk muscles contractions are capable of generating vertical ground reaction force oscillations that are consistent with the experimental results. These oscillations are apparently generated by a combination of cardiovascular and muscular forces. PMID:11347394

Pagnacco, G; Heiss, D G; Oggero, E

2001-01-01

113

Comparison of the classically conditioned withdrawal reflex in cerebellar patients and healthy control subjects during stance: I. electrophysiological characteristics.  

PubMed

The aim of this study was to demonstrate the involvement of the human cerebellum in the classically conditioned lower limb withdrawal reflex in standing subjects. Electromyographic activity was recorded from the main muscle groups of both legs of eight patients with cerebellar disease (CBL) and eight control subjects (CTRL). The unconditioned stimulus (US) consisted of electrical stimulation of the tibial nerve at the medial malleolus. The conditioning stimulus (CS) was an auditory signal given via headphones. Experiments started with 70 paired conditioning stimulus-unconditioned stimulus(CSUS) trials followed by 50 US-alone trials. The general reaction consisted of lifting and flexing the stimulated (stepping) leg with accompanying activation of the contralateral (supporting) leg. In CTRL, the ipsilateral (side of stimulation) flexor and contralateral extensor muscles were activated characteristically. In CBL, the magnitudes of ipsilateral flexor and contralateral extensor muscle activation were reduced comparably. In CTRL, the conditioning process increased the incidence of conditioned responses (CR), following a typical learning curve, while CBL showed a clearly lower CR incidence with a marginal increase, albeit, at a shorter latency. Conditioning processes also modified temporal parameters by shortening unconditioned response (UR) onset latencies and UR times to peak and, more importantly in CBL, also the sequence of activation of muscles, which became similar to that of CTRL. The expression of this reflex in standing subjects showed characteristic differences in the groups tested with the underlying associative processes not being restricted exclusively to the CR but also modifying parameters of the innate UR. PMID:22836373

Timmann, D; Kaulich, T; Föhre, W; Kutz, D F; Gerwig, M; Kolb, F P

2013-02-01

114

Speeds and stance of titanosaur sauropods: analysis of Titanopodus tracks from the Late Cretaceous of Mendoza, Argentina.  

PubMed

Speed estimations from trackways of Titanopodus mendozensis González Riga and Calvo provide information about the locomotion of titanosaurian sauropods that lived in South America during the Late Cretaceous. Titanopodus ichnites were found at Agua del Choique, a newly discovered track site in the Loncoche Formation, Late Campanian-Early Maastrichtian of Mendoza, Argentina. This speed study follows the hypothesis of dynamic similarity proposed by Alexander. As a refinement of this method, a complementary equation is presented here based on an articulated titanosaurian specimen collected in strata that are regarded as correlative to those that have yielded Titanopodus tracks (Allen Formation, Neuquén Basin). This analysis indicates that hip height can be estimated as 4.586 times the length of the pes track in derived titanosaurs. With an estimation of the hip height and the stride measurements, the speed is calculated. The study of two wide-gauge trackways indicates that Titanopodus ichnites were produced by medium-sized titanosaurs (hip height of 211-229 cm) that walked at 4.7-4.9 km/h towards the south and southwest, following, in part, a sinuous pathway. These speeds and some taphonomic features of tracks (prominent rims, distorted elongated shapes)indicate the capacity of derived titanosaurs for walking effectively over a very wet and slippery substrate. In the ichnological record, the walking speeds of Titanopodustrackmakers are somewhat faster than those previously inferred for most sauropods. PMID:21308347

González Riga, Bernardo J

2011-03-01

115

Winter 2013 Time Time Time Time Time  

E-print Network

11/8/2012 Winter 2013 Time Time Time Time Time Ugrad Grad Section Lab 590 Ugrad Grad Section Lab/143 quiz sections offered multiple times Thurs. (142) and T/Th (143) Grad courses TBD: 599v1, 517 548 517

Borenstein, Elhanan

116

Dynamic 3D scanning as a markerless method to calculate multi-segment foot kinematics during stance phase: methodology and first application.  

PubMed

Multi-segmental foot kinematics have been analyzed by means of optical marker-sets or by means of inertial sensors, but never by markerless dynamic 3D scanning (D3DScanning). The use of D3DScans implies a radically different approach for the construction of the multi-segment foot model: the foot anatomy is identified via the surface shape instead of distinct landmark points. We propose a 4-segment foot model consisting of the shank (Sha), calcaneus (Cal), metatarsus (Met) and hallux (Hal). These segments are manually selected on a static scan. To track the segments in the dynamic scan, the segments of the static scan are matched on each frame of the dynamic scan using the iterative closest point (ICP) fitting algorithm. Joint rotations are calculated between Sha-Cal, Cal-Met, and Met-Hal. Due to the lower quality scans at heel strike and toe off, the first and last 10% of the stance phase is excluded. The application of the method to 5 healthy subjects, 6 trials each, shows a good repeatability (intra-subject standard deviations between 1° and 2.5°) for Sha-Cal and Cal-Met joints, and inferior results for the Met-Hal joint (>3°). The repeatability seems to be subject-dependent. For the validation, a qualitative comparison with joint kinematics from a corresponding established marker-based multi-segment foot model is made. This shows very consistent patterns of rotation. The ease of subject preparation and also the effective and easy to interpret visual output, make the present technique very attractive for functional analysis of the foot, enhancing usability in clinical practice. PMID:24998032

Van den Herrewegen, Inge; Cuppens, Kris; Broeckx, Mario; Barisch-Fritz, Bettina; Vander Sloten, Jos; Leardini, Alberto; Peeraer, Louis

2014-08-22

117

Balance failure in single limb stance due to ankle sprain injury: an analysis of center of pressure using the fractal dimension method.  

PubMed

Instrumented postural control analysis plays an important role in evaluating the effects of injury on dynamic stability during balance tasks, and is often conveyed with measures based on the displacement of the center-of-pressure (COP) assessed with a force platform. However, the desired outcome of the task is frequently characterized by a loss of dynamic stability, secondary to injury. Typically, these failed trials are discarded during research investigations, with the potential loss of informative data pertaining to task success. The novelty of the present study is that COP characteristics of failed trials in injured participants are compared to successful trial data in another injured group, and a control group of participants, using the fractal dimension (FD) method. Three groups of participants attempted a task of eyes closed single limb stance (SLS): twenty-nine participants with acute ankle sprain successfully completed the task on their non-injured limb (successful injury group); twenty eight participants with acute ankle sprain failed their attempt on their injured limb (failed injury group); sixteen participants with no current injury successfully completed the task on their non-dominant limb (successful non-injured group). Between trial analyses of these groups revealed significant differences in COP trajectory FD (successful injury group: 1.58±0.06; failed injury group: 1.54±0.07; successful non-injured group: 1.64±0.06) with a large effect size (0.27). These findings demonstrate that successful eyes-closed SLS is characterized by a larger FD of the COP path when compared to failed trials, and that injury causes a decrease in COP path FD. PMID:24746034

Doherty, Cailbhe; Bleakley, Chris; Hertel, Jay; Caulfield, Brian; Ryan, John; Delahunt, Eamonn

2014-05-01

118

1 Introduction: The Dennettian Stance  

Microsoft Academic Search

In November 1998, a group of fifteen scholars gathered at Memorial University in St. John's, Newfoundland, with Daniel C. Dennett, to study his corpus of books and articles as a set, and assess the extent to which the pieces fit together as a comprehensive philosophical system. In his work on consciousness, Dennett has considered puz-zles over how the complex components

Don Ross

119

Just-In-Time Teaching  

NSDL National Science Digital Library

The very notion of "just-in-time" (JiTT) teaching may seem to some to sound like a phrase adopted from the world of corporate culture, but in fact, it's actually a "teaching and learning strategy based on the interaction between web-based study assignments and an active learner classroom." All told, it sounds pretty compelling, and this website, created by Professor Gregor and his colleagues at Indiana University-Purdue University Indianapolis (IUPUI) has been designed to provide fellow educators with materials that will help them adopt such an educational stance and approach in the classroom. After reading the introductory section titled "What is JiTT?", visitors may wish to proceed to look over the resources area, where they can look over JiTT resources that may be used with a variety of disciplines, including physics, psychology, and chemistry.

120

Fall risk-relevant functional mobility outcomes in dementia following dyadic tai chi exercise.  

PubMed

Whether persons with dementia benefit from fall prevention exercise is unclear. Applying the Positive Emotion-Motivated Tai Chi protocol, preliminary findings concerning adherence and effects of a dyadic Tai Chi exercise program on persons with Alzheimer's disease (AD) are reported. Using pre/posttest design, 22 community-dwelling AD-caregiver dyads participated in the program. Fall-risk-relevant functional mobility was measured using Unipedal Stance Time (UST) and Timed Up and Go (TUG) tests. Results showed that 19/22 (86.4%) AD patients completed the 16-week program and final assessment; 16/19 dyads (84.2%) completed the prescribed home program as reported by caregivers. UST adjusted mean improved from 4.0 to 5.1 (Week 4, p < .05) and 5.6 (Week 16, p < .05); TUG improved from 13.2 to 11.6 (Week 4, p < .05) and 11.6 (Week 16, p > .05) post intervention. Retaining dementia patients in an exercise intervention remains challenging. The dyadic Tai Chi approach appears to succeed in keeping AD-caregiver dyads exercising and safe. PMID:22517441

Yao, Lan; Giordani, Bruno J; Algase, Donna L; You, Mei; Alexander, Neil B

2013-03-01

121

Time Dependence Time Dependence  

E-print Network

Time Dependence 1/60 #12;Time Dependence deadline:= t + 5 2/60 #12;Time Dependence deadline:= t + 5 no problem 3/60 #12;Time Dependence deadline:= t + 5 no problem if t ;Time Dependence deadline:= t + 5 no problem if t Time

Hehner, Eric C.R.

122

Herpes genitalis and the philosopher's stance.  

PubMed

For many people, living with genital herpes generates not just episodic physical discomfort but recurrent emotional distress, centred on concerns about how to live and love safely without passing infection to others. This article considers the evidence on herpes transmission, levels of sexual risk, when the law has intervened and to what extent health professionals should advise with respect to these issues. It proposes a mechanism by which moral philosophy might provide a rational basis on which to counsel concerning sexual behaviour. PMID:24429670

Dunphy, Kilian

2014-12-01

123

Recognizing Stances in Online Debates Swapna Somasundaran  

E-print Network

"which mobile phone is better: iPhone or Blackberry," a participant on the iPhone side may explicitly assert and rationalize why the iPhone is better, and, alternatively, also ar- gue why the Blackberry their opinions, such as "The iPhone is cool," but, more often, they mention associated aspects. Some aspects

Wiebe, Janyce M.

124

Leg Strength or Velocity of Movement Which Is More Influential on the Balance of Mobility Limited Elders?  

PubMed Central

Objective To determine which component of leg power (maximal limb strength or limb velocity) is more influential on balance performance in mobility limited elders. Design In this cross-sectional analysis we evaluated 138 community-dwelling older adults with mobility limitation. Balance was measured using the Unipedal Stance Test, the Berg Balance Test (BERG), the Dynamic Gait Index, and the performance-oriented mobility assessment. We measured one repetition maximum strength and power at 40% one repetition maximum strength, from which velocity was calculated. The associations between maximal estimated leg strength and velocity with balance performance were examined using separate multivariate logistic regression models. Results Strength was found to be associated [odds ratio of 1.06 (95% confidence interval, 1.01–1.11)] with performance on the Unipedal Stance Test, whereas velocity showed no statistically significant association. In contrast, velocity was consistently associated with performance on all composite measures of balance [BERG 14.23 (1.84–109.72), performance-oriented mobility assessment 33.92 (3.69–312.03), and Dynamic Gait Index 35.80 (4.77–268.71))]. Strength was only associated with the BERG 1.08 (1.01–1.14). Conclusions Higher leg press velocity is associated with better performance on the BERG, performance-oriented mobility assessment, and Dynamic Gait Index, whereas greater leg strength is associated with better performance on the Unipedal Stance Test and the BERG. These findings are likely related to the intrinsic qualities of each test and emphasize the relevance of limb velocity. PMID:19033758

Mayson, Douglas J.; Kiely, Dan K.; LaRose, Sharon I.; Bean, Jonathan F.

2009-01-01

125

Telling Time  

NSDL National Science Digital Library

Lets practice telling time! Practice with the dragon to tell time. Dragon Telling Time How long does it take you to tell time?Stop the Clock! Can you set the correct time? Try it here! Setting the correct time ...

Berman, Ms.

2008-11-12

126

Telling Time  

NSDL National Science Digital Library

Practice telling time with these fun games and activities! Match the time on the clocks with this game! Match the clocks game! Primary Games Match the Clocks Tell time with a dragon. Stop the clock! Make the right time! Time to the Hour Quiz Time Test Time to the Minute Quiz Practice telling what time it will be later. Elapsed Time Work on Elapsed Time Test your skills with the Matching Elapsed Time Game ...

Lerdahl, Miss

2010-01-26

127

Starting Time Ending Time Starting Time  

E-print Network

Starting Time Ending Time Starting Time Name Of The Department/Unit Organizing The Event N How Would You Like Parking Arrangements Handled? Attendant Time (3 hour minimun): ) r e b m u N t n u-business hours. We may not be able to provide parking, depending on time of day and location. Consider public

Sjölander, Kimmen

128

Starting Time Ending Time Starting Time  

E-print Network

Starting Time Ending Time Starting Time Name Of The Department/Unit Organizing The Event N How Would You Like Parking Arrangements Handled? Attendant Time (3 hour minimun): Campus Department to schedule your event during non-business hours. We may not be able to provide parking, depending on time

Sjölander, Kimmen

129

Telling Time  

NSDL National Science Digital Library

Practice telling time with these fun games and activities! Match the time on the clocks with this game! Match the clocks game! Tell time with a dragon. Stop the clock! Practice telling what time it will be later. Elapsed Time ...

Fiefia, Mrs.

2010-03-23

130

Telling Time  

NSDL National Science Digital Library

Students - These games will help you practice telling time and calculating time measurements. Students practice telling time from an analog clock. Play this game to figure out What time is it? Play this game at least 15 times, then come back and play another clock game. Students practice your telling time skills by clicking here. In this game you determine What time will it be?. Play this game at least 10 times. After ...

Udy, Mr.

2006-11-14

131

Time Relationships.  

ERIC Educational Resources Information Center

Discusses ways that authors use time as it relates to the setting or time period, and to reveal changes throughout the story. Provides activities for elementary school students to help them understand how authors show time and changes, includes a worksheet to show examples of time relationships, and suggests assessment possibilities. (LRW)

Davis, Jonathan; Davis, Lisa

2001-01-01

132

A lower-limb training program to improve balance in healthy elderly women using the T-bow device.  

PubMed

Ageing impairs balance, which increases the risk of falls. Fall-related injuries are a serious health problem associated with dependency and disability in the elderly and results in high costs to public health systems. This study aims to determine the effects of a training program to develop balance using a new device called the T-Bow. A total of 28 women > 65 years were randomly assigned to an experimental group (EG) (n = 18; 69.50 [0.99] years), or a control group (CG) (n = 10; 70.70 [2.18] years). A program for lower limbs was applied for 8 weeks using 5 exercises on the T-Bow: squat, lateral and frontal swings, lunges, and plantarflexions. The intensity of the exercises was controlled by time of exposure, support base, and ratings of perceived exertion. Clinical tests were used to evaluate variables of balance. Static balance was measured by a 1-leg balance test (unipedal stance test), dynamic balance was measured by the 8-foot-up-and-go test, and overall balance was measured using the Tinetti test. Results for the EG showed an increase of 35.2% in static balance (P < 0.005), 12.7% in dynamic balance (P < 0.005), and 5.9% in overall balance (P > 0.05). Results for the CG showed a decline of 5.79% in static balance (P > 0.05) but no change in the other balance variables. Thus the data suggest that implementing a training program using the T-Bow could improve balance in healthy older women. PMID:20048519

Chulvi-Medrano, Iván; Colado, Juan C; Pablos, Carlos; Naclerio, Fernando; García-Massó, Xavier

2009-06-01

133

Elapsed Time  

NSDL National Science Digital Library

This interactive Java applet allows the user to practice finding elapsed time using analog or digital clocks. Using the "See" mode the user advances a clock from the beginning time to the ending time and the applet calculates the elapsed time. Using the "Guess" mode, the user must calculate the elapsed time between the given beginning and ending times. Three difficulty levels allow the user to practice with hour, five minute, or single minute increments. An optional scoring feature allows the user to keep track of number correct, though this feature is optional.

2007-01-01

134

TIME MANAGEMENT Time Management Questionnaire  

E-print Network

TIME MANAGEMENT WORKSHOP #12;2 Time Management Questionnaire Self Assessment: Answer "Yes" or "No you tend to complete your assignments on time? 3. ____ Have you estimated how long it takes to read schedule time to study for exams? 8. ____ Do you have a job that requires more than 20 hours a week? 9

135

Developmental Time  

Microsoft Academic Search

The concept of developmental time is proposed as a method for organizing family therapy interventions. Developmental time is the point in the family life cycle that a family expects to be occupying given the age and stage of its members. We promote alterations in the normative time frame by encouraging family members to relive previous developmental transitions or enact anticipated

Stephen A. Anderson; William M. Boylin

2000-01-01

136

Time lapse  

NSDL National Science Digital Library

Time lapse videos and photography allow us to visualize parts of certain events that we wouldn't normally be able to piece together. Since decay takes time, the causal relationships of this phenomenon can be seen through the use of time lapse videos.

Olivia Worland (Purdue University;Biological Sciences)

2008-06-16

137

Modelling Time  

E-print Network

We briefly review two concepts of time - the usual time associated with "being" and more recent ideas, answering to the description of "becoming". The approximation involved in the former is examined. Finally we argue that it is (unpredictable) fluctuations that underlie time.

Burra G. Sidharth

2008-09-03

138

Reaction Time  

NSDL National Science Digital Library

In this activity, learners explore reaction time and challenge themselves to improve their coordination. Do you want to move faster? Catch that ball that you never seem to see in time? Use a simple test to help you improve your reaction (or response) time.

Science, New Y.

1999-01-01

139

Quantum Time  

E-print Network

Normally we quantize along the space dimensions but treat time classically. But from relativity we expect a high level of symmetry between time and space. What happens if we quantize time using the same rules we use to quantize space? To do this, we generalize the paths in the Feynman path integral to include paths that vary in time as well as in space. We use Morlet wavelet decomposition to ensure convergence and normalization of the path integrals. We derive the Schr\\"odinger equation in four dimensions from the short time limit of the path integral expression. We verify that we recover standard quantum theory in the non-relativistic, semi-classical, and long time limits. Quantum time is an experiment factory: most foundational experiments in quantum mechanics can be modified in a way that makes them tests of quantum time. We look at single and double slits in time, scattering by time-varying electric and magnetic fields, and the Aharonov-Bohm effect in time.

John Ashmead

2010-05-05

140

Geologic Time  

NSDL National Science Digital Library

The Earth is very old -- 4.5 billion years or more -- according to recent estimates. This vast span of time, called geologic time by earth scientists, is difficult to comprehend in the familiar time units of months and years, or even centuries. How then do scientists reckon geologic time, and why do they believe the Earth is so old? A great part of the secret of the Earth's age is locked up in its rocks, and our centuries-old search for the key led to the beginning and nourished the growth of geologic science.

Newman, William L.

1997-01-01

141

Time Machine  

NSDL National Science Digital Library

In this lesson students will experience how geological and biological events have occurred in a clear sequence of vast but measured time. Students are taken on a simulated voyage backward in time, to the beginning of our planet. They witness that beginning, the origin of life, and a number of key events leading to the present. This becomes a dramatic experience, involving body and mind, helping students to relate physically at least to the relative timing of events in geological and biological history, if not to the absolute vastness of that time.

Flammer, Larry

142

Geological Time  

NSDL National Science Digital Library

"Why do engineers need to know about geologic time?" That question is answered in this resource from the University of Saskatchewan's Department of Civil and Geological Engineering. Provided here is a discussion of the concepts of geological time; relative dating methods, such as correlation; and absolute dating methods, such as radiometric methods. Diagrams and charts are included to demonstrate these complex concepts.

2008-04-17

143

Managing Time.  

ERIC Educational Resources Information Center

This newsletter issue discusses time management techniques for parents of special needs children. Techniques include changing one's attitudes about perfection, prioritizing tasks, having a back-up plan, learning to say "no," asking for help, keeping things simple, hiring others, using waiting time wisely, and doing two things at once. Household…

Murphy, Linda; Della Corte, Suzanne

1991-01-01

144

Screen Time  

NSDL National Science Digital Library

This game asks you a series of questions about how much time you spend in front of a screen, not being active. It begins by pointing out that since we spend a lot of time in front of computer screens at work or school, additional time at home can really affect how healthy we are. It asks how much time you spend watching TV, playing computer games, and using the computer each day. It then adds up the total amount of screen time you spend every day, and calculates how many hours you spend a year in front of a screen. It also tells you if that's a healthy amount, and suggests ways to stay active while in front of screens.

Omsi

2007-01-01

145

Time Clocks  

NSDL National Science Digital Library

This exercise can be used to demonstrate changes in the Earth through time, and the length of time it took for those changes to take place. A list of Important Dates in Earth History is provided that contains the dates of the events shown on a time clock. The teacher can pick events from the list of key events and calculate (or have students calculate) the time for the key events they wish to use. A page-size image of the clock can be printed and turned into an overhead transparency. To better demonstrate the changes since the beginning of the Paleozoic Era, the same exercise could be done the second day of class, using only the last 570 million years of time.

Greb, Stephen

146

Finding time.  

PubMed

We understand time through our models of it. These are typically models of our physical chronometers, which we then project into our subjects. A few of these models of the nature of time and its effects on the behavior of organisms are reviewed. New models, such as thermodynamics and spectral decomposition, are recommended for the potential insights that they afford. In all cases, associations are essential features of timing. To make them, time must be discretized by stimuli such as hours, minutes, conditioned stimuli, trials, and contexts in general. Any one association is seldom completely dominant, but rather shares control through proximity in a multidimensional space, important dimensions of which may include physical space and time as rendered by Fourier transforms. PMID:23973706

Killeen, Peter R

2014-01-01

147

Exercise intensity progression for exercises performed on unstable and stable platforms based on ankle muscle activation.  

PubMed

Ankle sprains are a common sports injury. The literature focuses on the application of neuromuscular training for the improvement of balance, injury prevention and rehabilitation. However, there is a dearth of knowledge about the appropriate prescription of exercises using unstable platforms and surfaces. The purpose of this study was to devise an ankle rehabilitation or training program with exercise progression based on the extent of muscle activation, employing platforms with different levels of stability and additional resistance. A descriptive study of electromyography (EMG) during ankle exercises was performed with a convenience sample of healthy subjects. Forty-four subjects completed 12 exercises performed in a random order. Exercises were performed unipedally or bipedally with or without elastic tubing as resistance on various unstable (uncontrolled multiaxial and uniaxial movement) and stable surfaces. Surface EMG from the tibialis anterior (TA), peroneus longus (PL) and soleus (SOL) were collected to quantify the amount of muscle activity. Significant differences were found between exercise conditions for PL (p<.001), TA (p=.011), and SOL (p<.001). The greatest EMG activity for all muscles occurred with an upright unipedal stance on a soft stability surface with resistance. The least EMG activity for the TA and SOL were in a seated position and for the PL in an erect bipedal position without resistance. Based on the level of ankle muscle activation, exercises for the ankle should progress from bilateral exercises on exercise balls (lowest intensity), to a unipedal position on a soft surface in combination with elastic tubing (highest intensity) in order to achieve progressively greater ankle muscle activation. PMID:23999147

Borreani, Sebastien; Calatayud, Joaquin; Martin, Julio; Colado, Juan Carlos; Tella, Victor; Behm, David

2014-01-01

148

On Time  

NSDL National Science Digital Library

This online exhibit from a prominent American museum explores the character of time -- its impact on our daily lives and its ability to shape and reform human consciousness. The site is from the National Museum of American History and concentrates on how humans have measured time from 1700 to the present. The exhibit presents text and images describing the history of keeping time from the century immediately preceding the industrial revolution -- when sundials were still in use -- to our present age of digital access and a global village that never sleeps.

149

Time warps  

E-print Network

I reconsider asymmetrically warped compactifications, in which time and space have different warp factors. I call such compactifications time warps if the bulk geometry has neither entropy nor temperature. I provide an example starting from an asymptotically AdS_5 spacetime where the speed of light, measured in a fixed coordinate system, is larger near the boundary than it is deep in the interior. This example follows the general plan of earlier work on superconducting black holes. To obtain a normalizable, four-dimensional graviton, one can introduce a Planck brane whose action includes a wrong-sign Einstein-Hilbert term. The equation of state of the Planck brane has w time warp geometry. Time warps of the type I describe provide an extra-dimensional description of boost invariance as an emergent symmetry in the infrared. High-energy violations of Lorent...

Gubser, Steven S

2008-01-01

150

Time outs  

MedlinePLUS

... Time-out technique for discipline. Children's Health Network web site. http://www.childrenshealthnetwork.org/CRS/CRS/pa_ ... a break from negative behavior. Massachusetts Medical Society web site. http://www.massmed.org/patient-care/health- ...

151

Time Management  

NSDL National Science Digital Library

This section of Mind Tools teaches you time management skills. These are the simple, practical techniques that have helped the leading people in business, sport and public service reach the pinnacles of their careers.

MindTools (MindTools)

2012-01-20

152

Timing During Interruptions in Timing  

ERIC Educational Resources Information Center

Duration and location of breaks in time interval production were manipulated in various conditions of stimulus presentation (Experiments 1-4). Produced intervals shortened and then stabilized as break duration lengthened, suggesting that participants used the break as a preparatory period to restart timing as quickly as possible at the end of the…

Fortin, Claudette; Bedard, Marie-Claude; Champagne, Julie

2005-01-01

153

Time warps  

Microsoft Academic Search

I reconsider asymmetrically warped compactifications, in which time and space have different warp factors. I call such compactifications\\u000a time warps if the bulk geometry has neither entropy nor temperature. I provide an example starting from an asymptotically\\u000a AdS\\u000a 5 spacetime where the speed of light, measured in a fixed coordinate system, is larger near the boundary than it is deep

Steven S. Gubser

2010-01-01

154

Time 100  

NSDL National Science Digital Library

This Time Warner Pathfinder (discussed in the November 11, 1994 Scout Report) Time Magazine site, released to coincide with a Time cover story of the same title, is the first in what is to be a five part site that will eventually cover 100 of the 20th Century's most influential people. At present the site contains profiles of 20 of the century's most influential "leaders & revolutionaries," including Margaret Sanger, Vladimir Lenin, Winston Churchill, Dr. Martin Luther King, Jr., Ayatolla Ruholla Khomeini, and the anonymous Chinese protester who blocked the tank in the Tienanmen Square protest in 1989. Stories about the personalities by such authors as Gloria Steinem, Arthur Schlesinger, Jr., Salman Rushdie, Elie Wiesel, and Stanley Karnow, among others, highlight the site. There is also a timeline of each personality, as well as a timeline of the century. For the personalities who were covered by Time, an original in-depth story from the Time archives is available. Forthcoming throughout 1998 and 1999 are sections on "entertainers & artists, builders & titans, scientists & thinkers, and heroes and inspirations." The site is also available in a Shockwave Flash version.

1998-01-01

155

Time warps  

E-print Network

I reconsider asymmetrically warped compactifications, in which time and space have different warp factors. I call such compactifications time warps if the bulk geometry has neither entropy nor temperature. I provide an example starting from an asymptotically AdS_5 spacetime where the speed of light, measured in a fixed coordinate system, is larger near the boundary than it is deep in the interior. This example follows the general plan of earlier work on superconducting black holes. To obtain a normalizable, four-dimensional graviton, one can introduce a Planck brane whose action includes a wrong-sign Einstein-Hilbert term. The equation of state of the Planck brane has w time warp geometry. Time warps of the type I describe provide an extra-dimensional description of boost invariance as an emergent symmetry in the infrared. High-energy violations of Lorentz symmetry, if confined to a strongly coupled unparticle sector dual to the time warp geometry, might manifest themselves through unusual kinematic constraints. As an example, I explain how modifications of unparticle phase space would affect the decay of a heavy particle into a light visible sector particle plus unparticle stuff.

Steven S. Gubser

2008-12-30

156

"Forget time"  

E-print Network

Following a line of research that I have developed for several years, I argue that the best strategy for understanding quantum gravity is to build a picture of the physical world where the notion of time plays no role. I summarize here this point of view, explaining why I think that in a fundamental description of nature we must "forget time", and how this can be done in the classical and in the quantum theory. The idea is to develop a formalism that treats dependent and independent variables on the same footing. In short, I propose to interpret mechanics as a theory of relations between variables, rather than the theory of the evolution of variables in time.

Carlo Rovelli

2009-03-23

157

Deep Time  

NSDL National Science Digital Library

Earth has been significantly altered over its 4.6 billion year history by climate swings, volcanism, and drifting continents. These dynamic conditions, in turn, have influenced every living thing that has inhabited the planet. This interactive timeline discusses the concept of deep time, and allows users to learn about geological events, evolutionary transformations, and the extinction of species or whole families of organisms that once inhabited the planet, and to better appreciate the vast period of time over which these transformations have occurred. A background essay and discussion questions are included.

158

Geologic Time  

NSDL National Science Digital Library

This Classroom Connectors lesson plan discusses the characteristics of geologic time, including the law of superposition, fossil preservation, casts and molds, and various events through the history of the Earth. The site provides goals, objectives, an outline, time required, materials, activities, and closure ideas for the lesson. The Classroom Connectors address content with an activity approach while incorporating themes necessary to raise the activity to a higher cognition level. The major motivation is to employ instructional strategies that bring the students physically and mentally into touch with the science they are studying.

159

Reaction Time  

NSDL National Science Digital Library

This lab is not an inquiry activity. There are some students whose reaction times will not allow them to catch a 12 inch ruler. They may use a dowel, stick, strip of cardboard, etc. Although the students are led to believe that the point of the lab is to

Horton, Michael

2009-05-30

160

Geologic Time  

NSDL National Science Digital Library

This site contains 24 questions on the topic of geologic time, which covers dating techniques and unconformities. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit their answers and are provided immediate feedback.

Heaton, Timothy

161

Deep Time  

NSDL National Science Digital Library

In this video a Penn State professor refers to National Park canyons carved out by water and wind as he explains “deep time” - the notion that the earth is billions of years old; another professor states how the theory of evolution is supported by evidence of an ancient Earth recorded in rocks.

Wpsu

2010-05-04

162

Time Remains  

E-print Network

On one popular view, the general covariance of gravity implies that change is relational in a strong sense, such that all it is for a physical degree of freedom to change is for it to vary with regard to a second physical degree of freedom. At a quantum level, this view of "change as relative variation" leads to a "fundamentally timeless" formalism for quantum gravity. Here, we will show how one may avoid this acute `problem of time'. Under our view, duration is still regarded as relative, but temporal succession is taken to be absolute. Following our approach, which is presented in more formal terms in arXiv:1303.7139, it is possible to conceive of a genuinely dynamical theory of quantum gravity within which time, in a substantive sense, remains.

Sean Gryb; Karim Thebault

2014-08-12

163

Time Traveler  

NSDL National Science Digital Library

This NOVA website simulates travel to distant stars and back in a spaceship that can move at various percentages of the speed of light. You set the spaceship speed and choose your destination star, and the simulation calculates the time of travel as measured on Earth and inside the spaceship. Text describes the "twin paradox" of the theory of relativity and also the 1971 test of its prediction using airliners and atomic clocks.

2011-10-15

164

accelerates Slow time Fast time  

E-print Network

= gravity (complexity) Programmer Computer Earth Figure 2: TIME WARP (Tower Paradox, effects of gravity here clocks freeze BLACK HOLE even horizon Programmer's view Computer's view Figure 5: The speed-up effect can be made "infinite" by using a black hole. 5 #12;Rotating Black Hole all signals sent

165

The Adaptationist Stance and Evolutionary Computation Mark Jelasity  

E-print Network

subsystem such as a food chain to be our organism. P4 (one niche): Beside P2 it is also necessary as in biology and this application may have significant benefits. It will also be shown that this approach has the following principles in order to be applicable: P1 (separation): The separation of the organism under in

Jelasity, Márk

166

SEN Students' Inclusion in Greece: Factors Influencing Greek Teachers' Stance  

ERIC Educational Resources Information Center

The present study, based on recent research in secondary education schools in Greece, aimed at recording Greek teachers' attitudes towards inclusion and determining the factors that enhance positive attitudes or negative ones. The findings of this research confirm that Greek teachers, despite obvious infrastructural and institutional hindrances,…

Koutrouba, Konstantina; Vamvakari, Malvina; Theodoropoulos, Helen

2008-01-01

167

Links between Parents' Epistemological Stance and Children's Evidence Talk  

ERIC Educational Resources Information Center

Recent experimental research highlights young children's selectivity in learning from others. Little is known, however, about the patterns of information that children actually encounter in conversations with adults. This study investigated variation in parents' tendency to focus on testable evidence as a way to answer science-related questions…

Luce, Megan R.; Callanan, Maureen A.; Smilovic, Sarah

2013-01-01

168

APPS's stance on self-plagiarism: Just say no.  

PubMed

Should authors be able to reuse the same text in multiple papers without citing the earlier source? Known as self-plagiarism, this practice is strongly discouraged in Applications in Plant Sciences (APPS) because it violates professional standards, is potentially deceptive, and lacks originality. The most frequent form of self-plagiarism in APPS submissions is text recycling, which depending on the extent and location of copied text, has consequences ranging from authors being required to rewrite duplicated text or add citations, to automatic rejection of a manuscript without review. Ultimately, avoidance of self-plagiarism will result in original articles that improve upon, and do not simply replicate, the existing literature. PMID:25202643

Culley, Theresa M

2014-07-01

169

Teachers' Stances towards Chinese International Students: An Australian Case Study  

ERIC Educational Resources Information Center

The international marketing of school education has gathered momentum in the Asia Pacific region, where an English medium education is prized by many parents. This paper investigates the responses of a group of teachers in Australia to the needs of international students in their school. The analysis of a 1 h professional discussion between four…

Love, Kristina; Arkoudis, Sophie

2006-01-01

170

Teachers’ stances towards Chinese international students: An Australian case study  

Microsoft Academic Search

The international marketing of school education has gathered momentum in the Asia Pacific region, where an English medium education is prized by many parents. This paper investigates the responses of a group of teachers in Australia to the needs of international students in their school. The analysis of a 1h professional discussion between four teachers in one school context shows

Kristina Love; Sophie Arkoudis

2006-01-01

171

Toward an Intercultural Stance: Teaching German and English through Telecollaboration  

ERIC Educational Resources Information Center

We discuss the challenges of Web-based teaching for language teachers and then describe in detail an extended episode of misunderstanding that occurred between 2 students discussing their versions of history during a classroom-based, asynchronous telecollaborative project between learners of German in the United States and learners of English in…

Ware, Paige D.; Kramsch, Claire

2005-01-01

172

Toward an Intercultural Stance: Teaching German and English through Telecollaboration  

Microsoft Academic Search

We discuss the challenges of Web-based teaching for language teachers and then describe in detail an extended episode of misunderstanding that occurred between 2 students discussing their versions of history during a classroom-based, asynchronous telecollaborative project be- tween learners of German in the United States and learners of English in Germany. We argue that discussion of such moments of miscommunication

PAIGE D. WARE; CLAIRE KRAMSCH

2005-01-01

173

New Instrumentation for Measurement of Man's Stability of Stance.  

National Technical Information Service (NTIS)

An instrumentation system for measurement of postural equilibrium in man was developed. The device consists of an electronic platform which continuously measures the location of the physiologic gravicenter in the horizontal plane and a circuit which reduc...

E. D. Grassman, Y. V. Terekhov

1973-01-01

174

Developing an Assessment Stance in Primary Art Education in England  

Microsoft Academic Search

Many English primary teachers find the notion of assessing children's work in art difficult. This paper reports on work carried out with non?art?specialist primary teachers’ and student teachers’ use of a three?point assessment model and related tasks, which supported teachers and students to engage critically with children's development, or lack of it, in observational drawing. This enabled teachers and students

Jean Gilbert

1996-01-01

175

Conveying a Stance of Religious Pluralism in Children's Literature  

ERIC Educational Resources Information Center

Religious discrimination is a global concern, as social dissonance and devastating violence result from religious intolerance. In order to develop socially competent, global citizens and create a peaceful society, religious diversity must be explored in public school classrooms; yet it remains a controversial and seldom addressed topic. Children's…

Sanders, Jennifer; Foyil, Kris; Graff, Jennifer M.

2010-01-01

176

A multisensory integration model of human stance control  

Microsoft Academic Search

.   A model is presented to study and quantify the contribution of all available sensory information to human standing based\\u000a on optimal estimation theory. In the model, delayed sensory information is integrated in such a way that a best estimate of\\u000a body orientation is obtained. The model approach agrees with the present theory of the goal of human balance control.

Herman van der Kooij; Ron Jacobs; Bart Koopman; Henk Grootenboer

1999-01-01

177

Dialogic Teaching: Talk in Service of a Dialogic Stance  

ERIC Educational Resources Information Center

We consider what it means to be a dialogic teacher as characterized by Paulo Freire and Robin Alexander, and utilizing discourse analysis, we explicate how one elementary teacher's talk reflects these characteristics. We provide context for and analysis of a seven-minute discussion selected as a cumulative achievement the focal nine-year-olds are…

Boyd, Maureen Patricia; Markarian, William C.

2011-01-01

178

Morality and Foreign Policy. A Symposium on President Carter's Stance.  

ERIC Educational Resources Information Center

This monograph contains a critical examination of President Carter's view on ethics and foreign policy as expressed in his commencement speech at Notre Dame University on May 22, 1977. The book is organized into three parts. Part 1 contains Mr. Carter's speech entitled, "Power for Humane Purposes." Part 2 contains nine responses to the speech:…

Lefever, Ernest W., Ed.

179

Methods for Exploring Expressive Stance Michael Neff , Eugene Fiume  

E-print Network

exploration of the aesthetic space. Key words: computer animation, character animation, human modeling that help an animator with the expressive aspects of a character's poses. Three aspects are required in good feedback based balance control with a hybrid IK system that utilizes optimization based and analytic IK

Neff, Michael

180

Flood hazard science, policy, and values: A pragmatist stance  

Microsoft Academic Search

The New Orleans hurricane disaster of August 2005 amply illustrates the long-standing failure of relating science to effective policies for reducing flood losses. Particularly flawed is the myth that science constitutes a repository of authoritative knowledge that will objectively serve as the basis for effective policies. This flaw derives from presumptions about the nature of science that can be corrected

Victor R. Baker

2007-01-01

181

Predicting Stance in Ideological Debate with Rich Linguistic Knowledge  

E-print Network

Human Language Technology Research Institute University of Texas at Dallas Richardson, TX 75083 classification: given a post written for a two-sided online debate topic (e.g., "Should abortion be banned

Ng, Vincent

182

Female Team Overall Name Age Rank Time Rank Time Rank Time Pace Rank Time Rank Time Pace Time  

E-print Network

Female Team Overall Name Age Rank Time Rank Time Rank Time Pace Rank Time Rank Time Pace Time 1 Amy:56:27.6 Deborah Mc Eligot Deborah Storrings Male Team Overall Name Age Rank Time Rank Time Rank Time Pace Rank Time Rank Time Pace Time 1 Macon Fessenden 20 1 5:42.2 2 0:26.9 1 34:29.7 3:23 1 0:12.8 1 17:41.1 3

Suzuki, Masatsugu

183

Time Entry and Time Entry Approvals  

E-print Network

Time Entry and Time Entry Approvals PS Version 8.8 Contents (Updated: October, 2004) Hourly Employee Time Entry..................................................................................02 The Hourly Time and Earning Page .......................................................................03

Oklahoma, University of

184

Time Entry and Time Entry Approvals  

E-print Network

Time Entry and Time Entry Approvals PS Version 9.0 Contents (Updated: September, 2007) Hourly Employee Time Entry..................................................................................02 The Hourly Time and Earning Page .......................................................................03

Oklahoma, University of

185

Doing Time  

PubMed Central

Once convicted, the perpetrator of serious crime embarks upon a new journey: the challenge of adjusting to long-term imprisonment. Prisoners’ views of incarceration and the meaning of this experience may affect their later adjustment to life in the community. On the basis of brief narrative responses collected during an epidemiological survey of the psychological health of prisoners in France, this study examined the impact of incarceration on psychological state in a group of 59 inmates serving long sentences. Qualitative content analysis and computer-assisted linguistic analysis (using ALCESTE software) were performed on the textual data of open responses to three standard questions. Using a combination of these two approaches, seven categories of the subjective experience of prisoners in the sample were identified: the Outside World, Others, Punishment, Time, Affects and Impulses, Self-Concept, and Speech. Further qualitative analyses were then performed to compare the responses of Severely Mentally Ill (SMI) subjects and subjects with no psychiatric disorder. These analyses revealed contrasting attitudes towards incarceration. SMI subjects spoke in more hostile and persecutory terms about their experience in prison, attributing suffering to external circumstances, while subjects with no psychiatric disorder evoked similar themes, but with an introspective attitude. The themes evoked by mentally ill individuals in our sample suggest that their reactions to the prison environment arise in part from aspects of their psychiatric symptoms, and this may have relevance to future mental health policy and practices in criminal corrections. PMID:19619895

Yang, Suzanne; Kadouri, Alane; Revah-Levy, Anne; Mulvey, Edward P.; Falissard, Bruno

2009-01-01

186

Cosmic Times  

NSDL National Science Digital Library

This series of curriculum support materials and classroom activities explores how our understanding of the nature of the Universe has changed during the past 100 years. Students examine the process of science through the stories of the people and the discoveries that caused our understanding to evolve from a static universe to a Universe whose expansion is accelerating. The series illustrates the nature of science by tracing the process of discovery from the confirmation of Einsteinâs theory of gravity, to Hubbleâs evidence for the expanding Universe, to the detection of the microwave background, and finally to the discovery of dark energy. The series includes six posters, each resembling the front page of a newspaper from a particular time in this history with articles describing the discoveries. Each poster is accompanied by an on-line teacher guide and 4-5 downloadable, inquiry-based lessons, which teach the science, the process of science, and skills for science literacy. Two downloadable âNewsletterâ versions of the poster are available for individual student use: one with the same text as on the poster, while the second uses text at a lower reading level.

Lochner, James

2010-02-16

187

Peripheral neuropathy: an often-overlooked cause of falls in the elderly.  

PubMed

Peripheral neuropathy is common in the elderly and results in impairments in distal proprioception and strength that hinder balance and predispose them to falls. The loss of heel reflexes, decreased vibratory sense that improves proximally, impaired position sense at the great toe, and inability to maintain unipedal stance for 10 seconds in three attempts all suggest functionally significant peripheral neuropathy. Physicians can help their patients with peripheral neuropathy to prevent falls by teaching them and their families about peripheral nerve dysfunction and its effects on balance and by advising patients to substitute vision for the lost somatosensory function, correctly use a cane, wear proper shoes and orthotics, and perform balance and upper extremity strengthening exercises. PMID:8668629

Richardson, J K; Ashton-Miller, J A

1996-06-01

188

Time Management Managing Time and Tasks  

E-print Network

hours, normal sleep/wake times, meals, exercise, standing appointments, commuting time, social and do them together. 9. Limit your time checking e-mail or social media. 10. Perfectionism can't always commitments. The hours that are left are your `free time' ­ study time, unscheduled down time, time left open

Kasman, Alex

189

SPACE-TIME--TIME Homer G. Ellis  

E-print Network

SPACE-TIME--TIME Homer G. Ellis Abstract. Space-time--time is a natural hybrid of Kaluza's #12;ve-dimensional geometry and Weyl's conformal space-time geometry. Translations along the secondary time dimension pro" and is applicable to metrics of all dimensionalities and signatures. The de Sitter space-time metric

Ellis, Homer

190

Time Warp Invariance by Recoding Time Delays into Time Delays  

E-print Network

Time Warp Invariance by Recoding Time Delays into Time Delays David J.C. MacKay University of Cambridge March 20th, 1996 Abstract A little investigation of how easy it is to get time warp invariance using your trick of coupling a decaying response g(t) to a time advance associated with a subthreshold

MacKay, David J.C.

191

TIME & LABOR TRAINING MANUAL  

E-print Network

1 TIME & LABOR TRAINING MANUAL TIME APPROVAL /2013 #12;2 TABLE OF CONTENTS TIME APPROVAL - THINGS TO REMEMBER ..................................................................... 3 TIME APPROVAL - QUICK GUIDE

Barrash, Warren

192

Internet time synchronization: the network time protocol  

Microsoft Academic Search

The network time protocol (NTP), which is designed to distribute time information in a large, diverse system, is described. It uses a symmetric architecture in which a distributed subnet of time servers operating in a self-organizing, hierarchical configuration synchronizes local clocks within the subnet and to national time standards via wire, radio, or calibrated atomic clock. The servers can also

David L. Mills

1991-01-01

193

Being, doing, knowing, and becoming: Science and opportunities for learning in the out-of-school-time setting  

NASA Astrophysics Data System (ADS)

This dissertation addresses the question of how structured out-of-school-time settings, such as afterschool programs and summer camps, are positioned to support children's engagement and learning in science. This study addresses a gap in the research literature that does not fully specify the nature of the out-of-school-time (OST) setting and that generally does not position learning and development in relationship to one another, instead focusing on one or the other. As a result of an incomplete conceptualization of the OST setting as a site for learning and development, the OST field is becoming increasingly academicized, and its developmental qualities and benefits for children are under siege. A transformative activist stance (Stetsenko, 2008) guides my goals in undertaking this study -- to produce knowledge that can inform the design and implementation of OST science programs -- and it also guides my analysis of what constitutes learning in OST science. A transformative activist stance is a perspective on cultural-historical theory that understands individual development as occurring through agentive, goal-directed efforts to change one's self and one's world. These goals and actions are always developed and enacted in cultural-historical context. Learning, which occurs through the appropriation of cultural tools and schema to achieve one's purposes, and which leads human development, is understood broadly, as entailing processes of being, doing, knowing and becoming (see Herrenkohl & Mertl, in press). I also draw on bioecological theory (Bronfenbrenner, 1979) to analyze the proximal processes that support and sustain children's participation in the OST setting. In this study, I analyze the structural, developmental, and conceptual features of three different OST science programs to understand how they create opportunities for learning and engagement in science. The contributions of this study are to better specify the nature of the OST science program setting and to better conceptualize how learning and development relate to one another in the context of OST science. I draw on my analysis to make recommendations for ways in which OST science learning can be expanded and enriched for more children in more settings.

Bevan, Bronwyn

194

TIME SERIES Syllabus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii  

E-print Network

TIME SERIES Contents Syllabus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv 1 Models for time series 1 1.1 Time series data Time series analysis refers to problems in which observations are collected at regular time intervals

Weber, Richard

195

Value of Travel Time.  

National Technical Information Service (NTIS)

The Record includes 6 papers covering important areas of travel time value analysis, such as travel time value theory, conceptual problems in travel time value, methods of deriving travel time values, review of empirical travel time value studies, applica...

R. Gronau

1976-01-01

196

real time LTL 1 Real Time LTL  

E-print Network

real time LTL 1 Real Time LTL ' ::= p j :' j (' ^ ') j X' j (' U') j #20; 1 #20; #20; 2 j #20; 1 freeze quanti#12;cation. real time LTL 2 Examples \\Every request p is followed by a response q within 10 time units." Gx:(p ) Fy:(q ^ y #20; x + 10)) \\Eventually within 10 time units p holds." x:Fy:(p ^ y #20

Popeea, Corneliu - Chair for Foundations of Software Reliability and Theoretical Computer Science

197

Terrific Time Telling  

NSDL National Science Digital Library

Have fun learning how to tell time! First, let's telling time with Dragon. Now that you can tell time with dragon, you have to choose the time!. Time can move fast. Do you think you can keep up? Use your knowledge of time to Stop the clock!. Now that you can keep up with time, can you decide What time will it be? Finally! You have learned so much about time, ...

Triola, Ms.

2009-04-19

198

Motor antagonism exposed by spatial segregation and timing of neurogenesis  

Microsoft Academic Search

Walking is a key motor behaviour of limbed animals, executed by contraction of functionally antagonistic muscle groups during swing and stance phases. Nevertheless, neuronal circuits regulating the activation of antagonistic extensor–flexor muscles remain poorly understood. Here we use monosynaptically restricted trans-synaptic viruses to elucidate premotor anatomical substrates for extensor–flexor control in mice. We observe a medio-lateral spatial segregation between extensor

Marco Tripodi; Anna E. Stepien; Silvia Arber

2011-01-01

199

Stretch, time lenses, and incoherent time imaging  

NASA Astrophysics Data System (ADS)

The stretch, or time-lens, concept is developed further. Alternative formulations that lead to invariant systems are described, as well as methods for synthesizing the time equivalent of spatially and temporally incoherent systems.

Naulleau, P.; Leith, E.

1995-07-01

200

'Stutter timing' for charge decay time measurement  

NASA Astrophysics Data System (ADS)

The paper describes the approach of 'stutter timing' that has been developed to improve the accuracy of measuring charge decay times in the presence of noise in compact and portable charge decay test instrumentation. The approach involves starting and stopping the timing clock as the noisy signal rises above and falls below the target threshold voltage level.

Chubb, John; Harbour, John; Pavey, Ian

2011-06-01

201

Time Commitments Where Does Your Time Go  

E-print Network

of class per week = ____ Number of hours per week with friends, social parties, going out, etc that it is often more effective to use a `study-break-study' plan rather than try to study for hours at a time and have some extra free time! Realize you can't do it all. If your final time on the front is a negative

Kasman, Alex

202

Time on Your Hands: Modeling Time  

ERIC Educational Resources Information Center

Building physical models relative to a concept can be an important activity to help students develop and manipulate abstract ideas and mental models that often prove difficult to grasp. One such concept is "time". A method for helping students understand the cyclical nature of time involves the construction of a Time Zone Calculator through a…

Finson, Kevin; Beaver, John

2007-01-01

203

Geological Time Scale  

NSDL National Science Digital Library

This document describes how geologic time is approached in discussions of geologic topics. The uses of relative time and absolute time are compared, and a geologic time scale is provided to represent both concepts. References are provided.

204

Times of Our Lives.  

ERIC Educational Resources Information Center

Lists activities parents can build into their schedules to strengthen their families and help their students succeed, noting the three keys to scheduling during the school year (clarity, discipline, and flexibility). Activities involve: getting ready time, teaching time, friend time, playtime, reading time, down time, adventure time, practice…

Ramsay, John G.

2001-01-01

205

Elapsed Time Two  

NSDL National Science Digital Library

In this activity, students are prompted with a starting time on a clock and a certain amount of elapsed time. In âseeâ mode, students add time to the clock in order to see what time it will be after the elapsed time. In âguessâ mode, students must enter in a guess for what time it will be given a starting time and elapsed time. This activity allows students to practice reading clocks and explore elapsing time. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

2010-01-01

206

Time fractional Schrödinger equation  

Microsoft Academic Search

The Schrödinger equation is considered with the first order time derivative changed to a Caputo fractional derivative, the time fractional Schrödinger equation. The resulting Hamiltonian is found to be non-Hermitian and nonlocal in time. The resulting wave functions are thus not invariant under time reversal. The time fractional Schrödinger equation is solved for a free particle and for a potential

Mark Naber

2004-01-01

207

Time and Labor Manual -Time Keepers -LSUSH  

E-print Network

Time and Labor Manual - Time Keepers - LSUSH Version Date: July 2012 #12;COPYRIGHT & TRADEMARKS be subject to the restrictions and license terms set forth in the applicable Government contract, and, to the extent applicable by the terms of the Government contract, the additional rights set forth in FAR 52

208

Neuropharmacology of timing and time perception  

Microsoft Academic Search

Time is a guiding force in the behavior of all organisms. For both a rat in an experimental setting (e.g. Skinner box) trying to predict when reinforcement will be delivered and a human in a restaurant waiting for his dinner to be served an accurate perception of time is an important determinant of behavior. Recent research has used a combination

Warren H. Meck

1996-01-01

209

Time and Cosmic Clock  

E-print Network

The nature of time vis-a-vis relativity is critically examined. Based on the author's space-time interaction hypothesis of late 1970's, cosmological model with time-varying velocity of light is discussed.

S. C. Tiwari

2001-11-20

210

The Hands of Time  

NSDL National Science Digital Library

Students explore the different ways to measure time and develop their understanding of how to tell time to the hour, half and quarter hours, and then five minute intervals. They identify time on analog and digital clocks and read a clock at the hour or half hour. They participate in timed events and keep time as record keepers. In the final lesson, students make a My Time Book.

Service, National S.

2009-04-22

211

Deep Time: The Geologic Time Scale  

NSDL National Science Digital Library

This page examines the issues involved in teaching students about the geologic time scale. There are suggestions for tackling troublesome issues in class as well as activities that can be used to clarify how geoscientists look at deep time. Five main concepts with which students struggle when thinking about Deep Time are addressed here: imagining or comprehending big numbers; the difference between relative and numerical age; the concept of "timescales"; the ways we know about the age of the Earth and other materials; and resolving perceived issues with religious beliefs.

Wenner, Jennifer M.

2011-04-25

212

On Time. 6b: Quantum Mechanical Time  

E-print Network

The existence of small amounts of advanced radiation, or a tilt in the arrow of time, makes the basic equations of physics mixed-type functional differential equations. The novel features of such equations point to a microphysical structure of time. This corresponds to a change of logic at the microphysical level. We show that the resulting logic is a quantum logic. This provides a natural and rigorous explanation of quantum interference. This structured-time interpretation of quantum mechanics is briefly compared with various other interpretations of q.m.

C. K. Raju

2008-08-09

213

On Time-II: Newton's Time.  

ERIC Educational Resources Information Center

A study of time in Newtonian physics is presented. Newton's laws of motion, falsifiability and physical theories, laws of motion and law of gravitation, and Laplace's demon are discussed. Short bibliographic sketches of Laplace and Karl Popper are included. (KR)

Raju, C. K.

1991-01-01

214

Did time begin? Will time end?  

E-print Network

Did time begin at a Big Bang? Will the present expansion of the universe last for a finite or infinite time? These questions sound philosophical but are becoming, now in the twenty-first century, central to the scientific study of cosmology. The answers, which should become clarified in the next decade or two, could have profound implications for how we see our own role in the universe. Since the original publication of Stephen Hawking's {\\it A Brief History of Time} in 1988, the answers to these questions have progressed as a result of research by the community of active theoretical physicists including myself. To present the underlying ideas requires discussion of a wide range of topics in cosmology, especially the make up of the energy content of the universe. A brief summary of my conclusions, that of three different possibilities concerning the history and future of time, the least likely is the conventional wisdom (time began and will never end) and most likely is a cyclic model (time never begins or ends), is in the short final Chapter which could be read first. To understand the reasoning leading to my conclusions could encourage reading of my entire book. My hope in writing this, my first popular book, is that it will engender reflection about time. Many a non-scientist may already hold a philosophical opinion about whether time begins and ends. This book's aim is to present some recently discovered scientific facts which can focus the reader's consideration of the two short questions in my title.

Paul H. Frampton

2007-04-09

215

Traveling Through Time  

NSDL National Science Digital Library

This video excerpt from NOVA’s The Fabric of the Cosmos: The Illusion of Time explains gravity’s pull on time, and how time travel may be possible in the future. However, this kind of time travel might not be exactly like Hollywood’s depiction.

Foundation, Wgbh E.

2012-02-10

216

Time reversal matched field  

Microsoft Academic Search

Time reversal techniques obtain increased resolution by exploiting scattering and multipath in propagation through inhomogeneous channels. Fink and collaborators has used time reversal to achieve super-resolution focusing in acoustics with controlled ultrasonic experiments in water tanks. More recently large-scale acoustics experiments in the ocean have confirmed the resolution ability of time reversal. In this paper, matched field detection with time

J. Moura

2004-01-01

217

The River of Time  

Microsoft Academic Search

The nature of time has long fascinated physicists and the general public. As an irresistible flow into which all events are embedded, time cannot be slowed or accelerated, nor can it be undone or turned back. In The River of Time , Igor Novikov describes how the thinkers throughout history have defined time and how these discoveries demonstrate that humans

Igor D. Novikov

2001-01-01

218

The River of Time  

Microsoft Academic Search

The nature of time has long fascinated physicists and lay people alike. As an irresistible flow into which all events are embedded, time cannot be slowed or accelerated. It cannot be undone or turned back. In this marvelous text, Novikov describes how the thinkers throughout history have defined time and how these discoveries demonstrate that we may influence time's flow.

Igor D. Novikov

1998-01-01

219

Breathing Time Warp  

Microsoft Academic Search

Time Warp and Breathing Time Buckets are two general-purpose optimistic synchronization strategies for supporting parallel discrete-event simulations. However, each one of these approaches has potential fatal shortcomings. Time Warp may exhibit rollback explosions that can cause an avalance of antimessages. Breathing Time Buckets, on the other hand, may not be able to process enough events per synchronization cycle to remain

Jeff S. Steinrnan

1993-01-01

220

Time and Teaching  

ERIC Educational Resources Information Center

This essay invites reflection on the phenomena of time as it impacts the day-to-day life of teachers. It also explores assumptions about time and teaching in three areas: first, beliefs about the force of time and the teacher's struggle to control it; second, beliefs about the potential of time and the benefits of its passing for teachers and…

McEwan, Anna E.

2012-01-01

221

What Time Is It?  

NSDL National Science Digital Library

Practice telling time with these activities. Match the time of the analog clock to the correct digital clockAnalog vs. Digital. Race against time in Stop the Clock! Help the dragon Set the Clock to the correct time. Grab a partner to play Willy the Watchdog . ...

Christen

2010-05-26

222

Tempus Fugit: Time Flies  

NSDL National Science Digital Library

This online exhibit from a prominent American museum explores the character of time -- its impact on our daily lives and its ability to shape and reform human consciousness. Tempus Fugit: Time Flies is a superb exhibit from the Nelson Atkins Museum of Art that uses items from the museum to exemplify different understandings of time. The exhibit features sections on 20th Century Time, World Times, and Conservation Time. Twentieth-century time considers the changing nature of time in the technological age by examining the innovations in graphic and plastic arts inspired by an altered sense of time. The exhibit includes works by Muybridge, Edward Hopper, Salvador Dali, Kandinsky, Rothko, Roy Lichtenstein, and others. The second section, World Times, focuses on the different conceptions of time embodied in art from primitive times to the present and ranges from ancient Native American to Medieval Europe to ancestral Africa to the deeply cosmological perceptions of time in ancient Indian civilizations. Conservation Time takes visitors behind the scenes to see how conservation science can uncover the history of a work's composition and the changes wrought upon it over the course of its lifetime. The Website also offers ideas for teaching using the exhibits. In sum, this is an elegantly constructed and intelligent Website. To be sure, users will want to set aside some time for it as the graphics enforce their own meditative pace upon the viewer.

223

Verification of timing routines  

SciTech Connect

A method for verifying the validity of timing routines for benchmarking and other timing measurements at the Los Alamos Scientific Laboratory (LASL) is described. A program written for this purpose uses two methods. The first method compares stopwatch times and system-computed times, where a system-computed time is the result of a call to the system timing routine. The second method requires calculating elapsed machine cycles. The program is modular and uses standard Fortran. With only a few changes, it is possible across all LASL systems and can be used on non-LASL systems as well. A complete benchmark job mix should include a program of this type.

Creel, L.R.

1980-01-01

224

Family Time: Time Management and Stress Reduction.  

ERIC Educational Resources Information Center

Whether people really have more or less free time than they did 20 years ago, it is undeniable that many families feel harried. There are many benefits to organized activities for children and adolescents, but parents must be careful not to overload a child's schedule. Every family is different, and it is up to the parents to decide what is…

Franklin, Diane, Ed.; Bankston, Karen, Ed.

225

Yes IT'S TIME! It's time for spring.  

E-print Network

time for you to read-enjoy! Arc@COFA. Kudos exhibition program page 15 COFA wins 2010 Fine Arts Soccer and enjoying the sun in what has been a pretty quiet courtyard this year. Final match after lunch saw COFA win for fun, exercise, that kinda thing, Tuesdays 1-2pm in Moore Park, just walk up Greens Rd from COFA, cross

New South Wales, University of

226

Time Management Learning Objectives  

E-print Network

the components and benefits of time management · Identify the differences between successful time management Calendar · Information to Include Class schedule Labs Work Research Student Org Meetings Exercise

Zhou, Chongwu

227

Time and Relativity  

NSDL National Science Digital Library

This video from the American Museum of Natural History illustrates Einstein's special theory of relativity and the relationship between time and the motion of objects, including the concept of time dilation.

Foundation, Wgbh E.

2007-08-09

228

No Time to Train.  

ERIC Educational Resources Information Center

Ways to overcome resistance to investing employee time in training include making training fit the available time, persuading management of the benefits, reexamining assumptions about teaching and learning, and switching from training to performance support. (SK)

Lee, Chris; Zemke, Ron

1995-01-01

229

Time-Varying Quantiles  

E-print Network

A time-varying quantile can be fitted to a sequence of observations by formulating a time series model for the corresponding population quantile and iteratively applying a suitably modified state space signal extraction algorithm. Quantiles...

Harvey, Andrew C; De Rossi, Giuliano

230

Time Schedule Preliminary  

E-print Network

#12;I · Time Schedule Preliminary Autumn Quarter 1985 Prer:egistration: May 21-24, 28 ... ;:,~ . ~ ·.. ',' ; . . . . . . . . . . . . . . . . . . . . . . . ... 6 Full-time Student 'Rcq~ent (veteran's benefits, Social Security , benefits, intemation~ students

Kaminsky, Werner

231

TIMELY WARNING CAMPUS ALERT  

E-print Network

TIMELY WARNING CAMPUS ALERT 25 February 2008 This communication is prepared as part of the Timely-in's and at least three burglaries. The purpose of this communication is to not only alert the campus community

Hardy, Christopher R.

232

TIMELY WARNING CAMPUS ALERT  

E-print Network

TIMELY WARNING CAMPUS ALERT April 5, 2007 This communication is prepared as part of the Timely wandering the halls. Two alert students reported the suspicious activity to the police as the suspects fled

Hardy, Christopher R.

233

Time Management. Revised.  

ERIC Educational Resources Information Center

This booklet presents concepts and applications of effective time management to help administrators learn to utilize their time most effectively, thereby accomplishing their most worthwhile objectives in the shortest amount of time. Although the booklet is designed to be self-administered, the greatest benefits should be derived in a group setting…

Halverson, Don E.

234

Time Change No Smoking!  

E-print Network

Highlights · Time Change · No Smoking! · Birthdays · Manners TheELIWeekly Set Your Clocks Daylight week's Weekly. Smoking An extra reminder this week, folks. From time to time, there are people smoking in areas where they shouldn't be. We want to be good neighbors! Smoking is NOT permitted in the following

Pilyugin, Sergei S.

235

Time Service Department  

NSDL National Science Digital Library

This site from the US Navy is the official source of time for the Department of Defense (DoD) and the Global Positioning System (GPS), and a Standard of Time for the United States. It features numerous links to other useful time and GPS-related sites.

Navy, U. S.

236

Noncommutative Two Time Physics  

E-print Network

We present a classical formalism describing two-time physics with Abelian canonical gauge field backgrounds. The formalism can be used as a starting point for the construction of an interacting quantized two-time physics theory in a noncommutative soace-time.

W. Chagas-Filho

2006-04-03

237

The Myth of Time.  

ERIC Educational Resources Information Center

This paper offers a variety of approaches to teaching the concept of time. Many social studies courses traditionally emphasize time as measured by clocks and as useful for recording when events occur in relation to each other. In addition to this approach, the author suggests that students should reflect upon four other modes of time. These are…

Hantula, James

238

Figure This: Time Zones  

NSDL National Science Digital Library

This is an activity featuring a time zone map useful when teaching an interdisciplinary social studies and math unit focusing on geography and the time zones. It underscores the role of the earth's rotation in everyday life, and the need to understand the relationships between earth rotation, day and night, and time zones around the world.

2004-01-01

239

TIMELY WARNING CAMPUS ALERT  

E-print Network

TIMELY WARNING CAMPUS ALERT 2 OCT 2007 This communication is prepared as part of the Timely Warning to students and employees in a manner that is timely and that may aid in the prevention of similar occurrences on Monday night. According to the early reports of the incident, two males in their late teens or early

Hardy, Christopher R.

240

TIMELY WARNING CAMPUS ALERT  

E-print Network

TIMELY WARNING CAMPUS ALERT 6 APRIL 2008 This communication is prepared as part of the Timely be provided to students and employees in a manner that is timely and that may aid in the prevention of similar teens or early twenties. The two black males were dressed completely in dark clothing, while the white

Hardy, Christopher R.

241

TIMELY WARNING CAMPUS ALERT  

E-print Network

TIMELY WARNING CAMPUS ALERT 12/03/07 This communication is prepared as part of the Timely Warning to students and employees in a manner that is timely and that may aid in the prevention of similar occurrences which reportedly took place early AM on 1 December 2007 in the area of Hillview Avenue and South Duke

Hardy, Christopher R.

242

Burrowing Through Time  

NASA Astrophysics Data System (ADS)

This excerpt is from a book written by J. Richard Gott III titled Time Travel in Einstein's Universe. He describes what it would be like to travel through space and time by way of wormholes. The author is a professor of astrophysical sciences at Princeton University and a leading expert in the physics of time travel.

Gott, Richard J.

2002-05-01

243

Time warp operating system  

Microsoft Academic Search

This paper describes the Time Warp Operating System, under development for three years at the Jet Propulsion Laboratory for the Caltech Mark III Hypercube multi-processor. Its primary goal is concurrent execution of large, irregular discrete event simulations at maximum speed. It also supports any other distributed applications that are synchronized by virtual time.The Time Warp Operating System includes a complete

David Jefferson; Brian Beckman; Fred Wieland; Leo Blume; Mike DiLoreto

1987-01-01

244

Principal curve time warping  

Microsoft Academic Search

Time warping finds use in many fields of time series analysis, and it has been effectively implemented in many different application areas. Rather than focusing on a particular application area we approach the general problem definition, and employ principal curves, a powerful machine learning tool, to improve the noise robustness of existing time warping methods. The increasing noise level is

Umut Ozertem; Deniz Erdogmus

2009-01-01

245

Time and Causation  

E-print Network

In this review paper, we consider the fundamental nature of time and causality, most particularly, in the context of the theories of special and general relativity. We also discuss the issue of closed timelike curves in the context of general relativity, and the associated paradoxes, the question of directionality of the time flow and, rather briefly, the problem of time in quantum gravity.

Orfeu Bertolami; Francisco S. N. Lobo

2009-02-03

246

Time-periodic universes  

E-print Network

In this letter we construct a new time-periodic solution of the vacuum Einstein's field equations whose Riemann curvature norm takes the infinity at some points. We show that this solution is intrinsically time-periodic and describes a time-periodic universe with the "black hole". New physical phenomena are investigated and new singularities are analyzed for this universal model.

De-Xing Kong; Kefeng Liu; Ming Shen

2008-08-30

247

Time or Space ' Fluctuating  

E-print Network

' Time or Space =0 2 2 ( ') Variance of ( ) Independent of space and time Concept of Spatial Homogeneity and Temporal Stationarity Correlation Function R 2 1 2 1 Space: R( ) '( ) '( ) R( ),x x x x x x x x 2 1 2 1 2 1 Time: R(t ) '( ) '( ) R(t); tt

Goodman, Louis

248

External Resource: Geologic Time  

NSDL National Science Digital Library

This NASA sponsored webpage, Center for Educational Technologies, teaches students about Geologic Time. The age of Earth is so long compared to all periods of time that we humans are familiar with, it has been given a special name: Geologic time. The age

1900-01-01

249

Time Management in College.  

ERIC Educational Resources Information Center

Time management may be the most important study skill. The effects of a specific teaching technique designed to alter the time management skills of undergraduate students in a voluntary study skills course were assessed. Of the 95 subjects, 34 were enrolled in the course and were exposed to time management instruction, 31 were future course…

Cranney, A. Garr; Kirby, Alan F.

250

International atomic time and time transfer  

NASA Astrophysics Data System (ADS)

Global Navigation Satellite Systems (GNSS) keep a central role in the international timekeeping. American Global Positioning System (GPS) is a navigation system that has proven itself to be a reliable source of positioning for both the military community and the civilian community. But, little known by many, is the fact that GPS has proven itself to be an important and valuabe utility to the timekeeping community (Lewandowski et al. 1999). GPS is a versatile and global tool which can be used to both distribute time to an arbitrary number of users and synchronise clocks over large distances with a high degree of precision and accuracy. Similar performance can be obtained with Russian Global Navigation Satellite System (GLONASS). It is expected in the near future satellites of a new European navigation system GALILEO might bring some important opportunities for international timekeeping. This paper after a brief introduction to international timekeeping focuses on the description of recent progress in time transfer techniques using GNSS satellites.

Lewandowski, Wlodzimierz

251

Modeling Geologic Time  

NSDL National Science Digital Library

In this activity students convert major events in Earth history from years before present into scale distances. After a list of events and their scale distances have been formulated, students construct a geologic time scale on 5 meters of adding machine paper, beginning with the formation of the Earth. Students will investigate change through geologic time; design, construct and interpret a model of geologic time; relate major events in Earth history to the geologic time scale; and compare and relate the span of Earth history to events of historical time and of the human lifetime. Some sample events and their approximate relative ages are included.

Firebaugh, James

252

Cosmic Times: Overview Lessons  

NSDL National Science Digital Library

The Cosmic Times Gallery Walk and Cosmic Times Jigsaw lessons serve as extensions to the Cosmic Times suite of curriculum support materials. They are intended to provide an introduction to Cosmic Times as a whole, giving students the larger picture of how our understanding of the universe has changed over the last century. During the Gallery Walk lesson, students peruse the Cosmic Times posters to answer open-ended questions. During the Jigsaw lesson, students work in cooperative teams to understand the primary scientific advances over the past century that have contributed to our current understanding of the universe.

253

Filling the Time  

NSDL National Science Digital Library

Build time sense into the schedule by asking learners to predict what can happen in a certain amount of time: We have 20 minutes before outdoor time. What can you get done? Everyone makes a prediction, for instance, how many rounds of a card game theyâll play or how many origami cranes they can make. Then, stop part-way through the time period and ask if anyone wants to revise their predictions. Available as a web page or downloadable pdf. Students should have some familiarity with time.

2010-01-01

254

Short time information in GPS time series  

NASA Astrophysics Data System (ADS)

This paper presents adjustment's results of the Polish Active Geodetic Network (ASG-EUPOS). ASG-EUPOS is the multifunctional precise satellite positioning system established by the Head Office of Geodesy and Cartography in 2008. It consists of 84 Polish sites with GPS module, 14 Polish sites with GPS/GLONASS module and 20 foreign sites. The adjusted network consisted of over 100 stations, the period covered observations collected from June 2008. The method of adjustment elaborated in the CAG, which is the newest, seventeenth EPN LAC (EPN Local Analysis Centre) established at the end of 2009, is similar with applied in EPN. It is based on the Bernese 5.0 software. The difference to the EPN's solutions lies in the resolution time of adjustment. In the presented research the 1-hour sampling rate with 3-hour windowing is applied. This allows us to make the interpretations concerning short time information in GPS coordinates series. The time span (over 1.5 year) permits the separation between the pure dynamic phenomena (tides) and thermal oscillations in the diurnal and sub-diurnal frequency bands. The presentation contains also the plans for multidimensional applications of the dense national active GNSS networks.

Araszkiewicz, Andrzej; Bogusz, Janusz; Figurski, Mariusz

2010-05-01

255

Time scales in LISA  

E-print Network

The LISA mission is a space interferometer aiming at the detection of gravitational waves in the [$10^{-4}$,$10^{-1}$] Hz frequency band. In order to reach the gravitational wave detection level, a Time Delay Interferometry (TDI) method must be applied to get rid of (most of) the laser frequency noise and optical bench noise. This TDI analysis is carried out in terms of the coordinate time corresponding to the Barycentric Coordinate Reference System (BCRS), TCB, whereas the data at each of the three LISA stations is recorded in terms of each station proper time. We provide here the required proper time versus BCRS time transformation. We show that the difference in rate of station proper time versus TCB is of the order of $5 10^{-8}$. The difference between station proper times and TCB exhibits an oscillatory trend with a maximum amplitude of about $10^{-3}$ s.

S. Pireaux

2007-03-23

256

On the Time Times Temperature Bound  

E-print Network

Recently Hod proposes a lower bound on the relaxation time of a perturbed thermodynamic system. For gravitational systems this bound transforms into a condition on the fundamental quasinormal frequency. We test the bound in some spacetimes whose quasinormal frequencies are calculated exactly, as the three-dimensional BTZ black hole, the D-dimensional de Sitter spacetime, and the D-dimensional Nariai spacetime. We find that for some of these spacetimes their fundamental quasinormal frequencies do not satisfy the bound proposed by Hod.

A. Lopez-Ortega

2010-06-28

257

Space and Time  

NSDL National Science Digital Library

This fun Web site is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here, they are introduced to space and time with six engaging and kid-friendly areas: Welcome to the Fourth Dimension, which looks at how time is needed to describe where you are in the fourth dimension; It's All Relative, an explanation of how time and space are different depending on your frame of reference; Mass Appeal, which uses the example of an elephant on a page of paper to explain how the Sun's mass causes space and time to bend; You Light Up My Life, how Arthur Eddington proved that Einstein's light-bending prediction was right; Everyday Einstein: Black Holes, an overview of these "bottomless dimples in space." and Time Travel Kit, a look at how the faster you move in space, the slower you move in time.

258

Time card entry system  

SciTech Connect

The Time Card Entry System was developed to interface with the DOE Headquarters Electronic Time and Attendance (ETA) system. It features pop-up window pick lists for Work Breakdown Structure Numbers and Hour Codes and has extensive processing that ensures that time and attendance reported by the employee fulfills US Government/OMB requirements before Timekeepers process the data at the end of the two week payroll cycle using ETA. Tours of Duty (e.g. ten hour day, four day week with Friday through Sunday off), established in the ETA system, are imported into the Time Card Entry System by the Timekeepers. An individual`s Tour of Duty establishes the basis for validation of time of day and number of hours worked per day. At the end of the two week cycle, data is exported by the Timekeepers from the Time Card Entry System into ETA data files.

Montierth, B.S.

1996-05-01

259

Looking Back in Time  

NSDL National Science Digital Library

This lesson plan will provide a concrete way for students to understand the concept of distance in space equals distance in time. This is done using information gathered from a timeline activity in Lesson 1: Earth, the Universe, and Culture. Students experiment with how distances are measured in space and create timelines to demonstrate the concept distance in space equals distance in time. This lesson is part of the "Swift: Eyes Through Time" collection that is available on the Teacher's Domain website.

260

Making Time for Feedback  

ERIC Educational Resources Information Center

Ask any teacher what he or she needs more of, and it is a good bet that time will top the list. Anything that promises to recoup a little bit of their workday time is sure to be a best seller. One overlooked time-saver is in how they use feedback. Teachers know that feedback is important for teaching and learning. Unfortunately, most secondary…

Fisher, Douglas; Frey, Nancy

2012-01-01

261

It's About Time  

NSDL National Science Digital Library

In past times, ocean navigators tossed a piece of wood over the side of their ships and noted how long until the ship passed the wood. They used this time measurement and the length of the ship to calculate their speed and estimate how far they had traveled. In this activity, students act the part of a GPS signal traveling to the receiver to learn how travel time is converted to distance.

Integrated Teaching And Learning Program

262

Matter: Space without Time  

E-print Network

While Quantum Gravity remains elusive and Quantum Field Theory retains the interpretational difficulties of Quantum Mechanics, we have introduced an alternate approach to the unification of particles, fields, space and time, suggesting that the concept of matter as space without time provides a framework which unifies matter with spacetime and in which we anticipate the development of complete theories (ideally a single unified theory) describing observed 'particles, charges, fields and forces' solely with the geometry of our matter-space-time universe.

Yousef Ghazi-Tabatabai

2012-09-14

263

Space-time gestures  

Microsoft Academic Search

A method for learning, tracking, and recognizing human gestures using a view-based approach to model articulated objects is presented. Objects are represented using sets of view models, rather than single templates. Stereotypical space-time patterns, i.e., gestures, are then matched to stored gesture patterns using dynamic time warping. Real-time performance is achieved by using special purpose correlation hardware and view prediction

Trevor Darrell; Alex Pentland

1993-01-01

264

Time integrating acoustooptic correlator.  

PubMed

This paper describes an acoustooptic technique for achieving signal correlation with a time-bandwidth product of 10(6)-10(8), using existing devices. One signal is used to intensity modulate a light beam that illuminates an acoustic cell. The other signal appears in the cell as a traveling wave and is Schlieren imaged onto a detector array. The detected image intensity is integrated in time, achieving the desired correlation function. Since the correlation integration is performed in time rather than space, the time-bandwidth limitations of earlier acoustooptic correlators are greatly reduced. Experimental procedures for implementation of this technique are discussed and results shown. PMID:20155190

Sprague, R A; Koliopoulos, C L

1976-01-01

265

Fields of Time  

NSDL National Science Digital Library

This outdoor exercise shows students the great expanse of time that has elapsed between the formation of Earth and the emergence of living creatures, particularly humans. The great length of the football field helps reinforce the idea of the vast amounts of time that have passed. Starting on one goal line, they will mark off distances representing the times of various events, rocks, fossils, or geologic eras. The teacher can calculate the distances needed, or students can do it themselves in the classroom. A table is provided to help convert distances in yards to time in millions of years, and links to additional information are included.

Greb, Stephen

266

Time estimation in flight  

NASA Technical Reports Server (NTRS)

Experiments were performed to determine whether edge rate and flow rate impact the perception of time during an active control task and to further examine the relationship between edge rate or flow rate and time perception. One experiment also examined the extent to which time perception is driven by: (1) the temporal structure of the world, i.e., edge rate/flow rate changes, and (2) the amount of activity involved in accomplishing a task. The second factor was varied by examining time estimations made while subjects passively viewed the simulated flight and while also actively engaged in controlling lateral craft disturbances.

Awe, Cynthia A.; Johnson, Walter W.

1991-01-01

267

British Museum: Explore: Time  

NSDL National Science Digital Library

What is time? What does it mean to us? These are a but a few of the arresting questions asked by the British Museum's online exhibit exploring the nature, structure, and history of time, time-keeping, and other related subjects. This particular section is part of their larger "Explore" online collection, and it draws on the British Museum's vast holdings to look into this scientific, cultural, and historical phenomenon. The site includes five sections, including Measuring and Keeping Time, Personal Time, and The Effects of Time. The Measuring and Keeping Time area is quite arresting, and it includes images of a Native American 'winter counts' cloth which served as a recorder of events that took place between 1785 and 1901. Moving on, The Effects of Time area is rather remarkable as well, as it contains material on how humans have attempted to stop or slow down the passage of time via techniques like retaining a youthful portrait of an aging ruler on coins and paper money.

268

What is Geologic Time?  

NSDL National Science Digital Library

This webpage of the National Park Service (NPS) and United States Geological Survey (USGS) discusses geologic time and what it represents. Beginning about 4.6 billion years ago and ending in the present day, this site exhibits (to scale) the various eras, periods, eons, and epochs of Earth's history with a downloadable geologic time scale available. Links provide maps of what the Earth looked like at various times in its history, as well as a description of how scientists developed the time scale and how they know the age of the Earth.

269

Tour of Geologic Time  

NSDL National Science Digital Library

This online tour offers users a 'journey' through the history of the Earth, with stops at particular points in time to examine the fossil record and stratigraphy. Clicking on an interactive time scale allows access to information on the geologc eras, from the Hadean (4.5- 3.8 billion years ago) to the Cenozoic (65 billion years ago to the present). Or, users can explore specific time periods by selecting the appropriate link, or study the history of the gelogic time scale.

270

Time functions as utilities  

E-print Network

Every time function on spacetime gives a (continuous) total preordering of the spacetime events which respects the notion of causal precedence. The problem of the existence of a (semi-)time function on spacetime and the problem of recovering the causal structure starting from the set of time functions are studied. It is pointed out that these problems have an analog in the field of microeconomics known as utility theory. In a chronological spacetime the semi-time functions correspond to the utilities for the chronological relation, while in a K-causal (stably causal) spacetime the time functions correspond to the utilities for the K^+ relation (Seifert's relation). By exploiting this analogy, we are able to import some mathematical results, most notably Peleg's and Levin's theorems, to the spacetime framework. As a consequence, we prove that a K-causal (i.e. stably causal) spacetime admits a time function and that the time or temporal functions can be used to recover the K^+ (or Seifert) relation which indeed turns out to be the intersection of the time or temporal orderings. This result tells us in which circumstances it is possible to recover the chronological or causal relation starting from the set of time or temporal functions allowed by the spacetime. Moreover, it is proved that a chronological spacetime in which the closure of the causal relation is transitive (for instance a reflective spacetime) admits a semi-time function. Along the way a new proof avoiding smoothing techniques is given that the existence of a time function implies stable causality, and a new short proof of the equivalence between K-causality and stable causality is given which takes advantage of Levin's theorem and smoothing techniques.

E. Minguzzi

2009-09-04

271

DRAM variable retention time  

Microsoft Academic Search

A DRAM bit has variable retention time (VRT) when the memory cell leakage, which determines how long a cell can retain information, varies with time. This paper reports on a study of VRT in cells from 4Mbit and 16 Mbit DRAM chips produced by a variety of manufacturers and in a number of technologies including trench capacitor and stacked capacitor

P. J. Restle; J. W. Park; B. F. Lloyd

1992-01-01

272

Digital time delay  

Microsoft Academic Search

Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits

1986-01-01

273

Standardizing distance and time  

E-print Network

Einstein's Equivalence Principle is used with the electromagnetic spectrum to translate meters and seconds into radians and seconds. Based on a unique geometric relationship, a new transformation of velocities and a changed Lorentz transformation result. The physical angle of parallelism is quantified. The way we measure distance and time is standardized, constructing a theory of time and geometry to the universe.

Russell Clark Eskew

2001-07-04

274

Estimating Distance and Time  

NSDL National Science Digital Library

Students learn to estimate the time it takes to travel different distances based on an estimation of the time it takes to travel a part of the whole route. This reinforces basic fractional/ratio thinking, as well as early multiplication as repeated addition.

Wnet

2008-08-22

275

Time in quantum mechanics  

E-print Network

The role of time in quantum mechanics has been and is still very controversial. The purpose of this paper was to explore the historical interpretation of time in quantum mechanics, to determine the current status of this problem-L and to investigate...

Chapin, Kimberly R.

2012-06-07

276

Bootstrapping time series models  

Microsoft Academic Search

This paper surveys recent development in bootstrap methods and the modifications needed for their applicability in time series models. The paper discusses some guidelines for empirical researchers in econometric analysis of time series. Different sampling schemes for bootstrap data generation and different forms of bootstrap test statistics are discussed. The paper also discusses the applicability of direct bootstrapping of data

G. S. Hongyi Li; G. S. Maddala

1996-01-01

277

Where in Time?  

NSDL National Science Digital Library

This engaging activity helps students construct their own understanding of Earth's history and understand the geologic time scale. While working through the activity, students learn science concepts related to geologic time and the value of cooperation and effective communication. The lesson is aligned to the following National Science Education Standards: Science as Inquiry, Earth's History, and the Nature of Science.

Sacks, David; Pecore, John

2005-10-01

278

Measuring entrepreneurship over time  

Microsoft Academic Search

This article is a review of three measurement issues that impact the study of entrepreneurship over time: (1) level of analysis difference between firms and individuals, (2) differences between rate and stock measures, and (3) the effects of choosing particular time frames on subsequent analytical results. Based on theory that views entrepreneurship as depending on ownership rights (Hawley 1907), this

Scott A. Shane

1995-01-01

279

Time and Teaching  

NASA Astrophysics Data System (ADS)

Time management is an important issue for teachers and students. This article discusses teachers' use of time from the perspective of curriculum and instruction. Average high school students spend fewer than 5 hours per week in outside-of-class study; average college students spend about 20 hours. Procrastination, often viewed in a negative light by teachers, usually pays off so well for college students that seniors become better at it than freshmen. Three suggestions for designing instruction are: test early and often; do not waste the best students' time in an effort to improve overall performance; and use engaging activities that motivate students to give of their time. The impact of computers on curricula is a double-edged sword. Time must be devoted to teaching the use of applications, but the programs reduce busywork. Will this turn out to be a simple tradeoff, or will the programs make us much more efficient so that less time is required? Will computer programs ultimately lead to an expanded criterion for expertise, thus demanding even more time to become an expert? These issues are described and suggestions for controlling time during instruction are provided.

Zielinski, Theresa Julia; Brooks, David W.; Crippen, Kent J.; March, Joe L.

2001-06-01

280

Managing Time and Stress.  

ERIC Educational Resources Information Center

Chapter 14 of a revised volume on school leadership, this chapter offers many practical suggestions for managing time and reducing stress. The primary challenge is to unblock the route to effective time/stress management by recognizing unproductive values and attitudes (such as overreliance on the Protestant work ethic or the appearance of…

Huffstutter, Sandra; Smith, Stuart C.

281

Acceleration of Time Integration  

SciTech Connect

We outline our strategies for accelerating time integration for long-running simulations, such as those for global climate modeling. The strategies target the Cray XT systems at the National Center for Computational Sciences at Oak Ridge National Laboratory. Our strategies include fully implicit, parallel-in-time, and curvelet methods.

White III, James B [ORNL; Drake, John B [ORNL; Worley, Patrick H [ORNL; Archibald, Richard K [ORNL; Evans, Katherine J [ORNL; Kothe, Douglas B [ORNL

2007-01-01

282

TIMELY WARNING CAMPUS ALERT  

E-print Network

TIMELY WARNING CAMPUS ALERT 23 January 2010 Posted 23 January 2010 This communication is prepared community. Such reports shall be provided to students and employees in a manner that is timely and that may a report of a sexual assault that reportedly took place during the early evening of Friday, 22 January 2010

Hardy, Christopher R.

283

TIMELY WARNING CAMPUS ALERT  

E-print Network

TIMELY WARNING CAMPUS ALERT Attempted Strong-Arm Robbery 12/02/11 This communication is prepared community. Such reports shall be provided to students and employees in a manner that is timely and that may was approached by a tall, approximately 6'5" B/M/late teens-early 20's wearing a gray hooded sweatshirt and nylon

Hardy, Christopher R.

284

Deciding branching time logic  

Microsoft Academic Search

In this paper we study the full branching time logic (CTL*) in which a path quantifier, either A (“for all paths-&-rdquo;) or E (-&-ldquo;for some path”), prefixes an assertion composed of arbitrary combinations of the usual linear time operators F (“sometime”), G (“always”), X (“nexttime”), and U (“until”). We show that the problem of determining if a CTL* formula is

E. Allen Emerson; A. Prasad Sistla

1984-01-01

285

Time Management Randy Pausch  

E-print Network

Time Famine" � Bad time management = stress � This is life advice #12;8 The Problem is Severe By some comes from bad judgment #12;12 Inspiration "If you can dream it, you can do it" Walt Disney � Disneyland was built in 366 days, from ground-breaking to first day open to the public. #12;13 Planning � Failing

286

Times Tables Grid Game  

NSDL National Science Digital Library

This Flash applet provides targeted practice of multiplication facts. After a player selects which group(s) of multiples to practice, the applet displays products one at a time, and the player locates a cell on a blank grid that identifies a possible factor pair. Users may choose to play timed or untimed, and must complete a round with no more than 5 errors.

2013-01-01

287

Sublinear-time Algorithms  

Microsoft Academic Search

In this paper we survey recent advances in the area of sublinear-time algorithms. He area of sublinear-time algorithmsis a new rapidly emerging area of computer science. It has its roots in the study of massive data sets that occur more and more frequently in var- ious applications. Financial transactions with billions o f input data and Internet traffic analyses (Internet

Artur Czumaj; Christian Sohler

2010-01-01

288

Is Time Inhomogeneous ?  

E-print Network

In this article, we discuss probability of inhomogeneous time in high or low energy scale of physics. Consequently, the possibility was investigated of using theories such as varying speed of light (VSL) and fractal mathematics to build a framework within which answers can be found to some of standard cosmological problems and physics theories on the basis of time non-homogeneity.

S. Davood Sadatian

2014-04-20

289

Create Date: Create Time  

E-print Network

Create Date: Create Time: User: 12/29/2010 10:48 AM arajan Page 1 of 56 Bill ID Chapter Number Lead Water Supply Act of 2012: groundwater contamination. Effective September 24, 2010. Bills Enacted In 2010;Create Date: Create Time: User: 12/29/2010 10:48 AM arajan Page 2 of 56 Bill ID Chapter Number Lead

290

Time for Literacy.  

ERIC Educational Resources Information Center

The instructor/author first started to think about the relationship between time and literacy when she was writing her dissertation and doing a study in a first-year composition course at a community college in Chicago. She realized that many teachers at community colleges think about the issue of time, as they realize it is something their…

Phillips, Cassandra

291

Time Series Data Library  

NSDL National Science Digital Library

This is a collection of time series datasets covering many application areas, but are all for time series analysis. Some of the topics covered are: agriculture, chemistry, crime, demography, ecology, finance, health, hydrology, industry, labor market, macroeconomics, physics, production, sales, sport, transportation, tourism, tree rings and utilities. The data are in text format, thus they can be used without any additional software.

Hyndman, Robert

2009-08-13

292

Outwitting the Time Thieves.  

ERIC Educational Resources Information Center

Tips to help music teachers develop time-management skills are presented. These include setting personal goals, keeping a time log, fighting procrastination, controlling interruptions, endorsing the art of selective omission, increasing delegation, self-pacing, practicing wastebasketry, and economizing work habits. (RM)

Delzell, Judith K.

1985-01-01

293

Mining Time Series Data  

NASA Astrophysics Data System (ADS)

Much of the world's supply of data is in the form of time series. In the last decade, there has been an explosion of interest in mining time series data. A number of new algorithms have been introduced to classify, cluster, segment, index, discover rules, and detect anomalies/novelties in time series. While these many different techniques used to solve these problems use a multitude of different techniques, they all have one common factor; they require some high level representation of the data, rather than the original raw data. These high level representations are necessary as a feature extraction step, or simply to make the storage, transmission, and computation of massive dataset feasible. A multitude of representations have been proposed in the literature, including spectral transforms, wavelets transforms, piecewise polynomials, eigenfunctions, and symbolic mappings. This chapter gives a high-level survey of time series Data Mining tasks, with an emphasis on time series representations.

Ratanamahatana, Chotirat Ann; Lin, Jessica; Gunopulos, Dimitrios; Keogh, Eamonn; Vlachos, Michail; Das, Gautam

294

Digital time delay  

DOEpatents

Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits latch the high resolution data to form a first synchronizing data set. A selected time interval has been preset to internal counters and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses count down the counters to generate an internal pulse delayed by an internal which is functionally related to the preset time interval. A second LCD corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD to generate a second set of synchronizing data which is complementary with the first set of synchronizing data for presentation to logic circuits. The logic circuits further delay the internal output signal with the internal pulses. The final delayed output signal thereafter enables the output pulse generator to produce the desired output pulse at the preset time delay interval following input of the trigger pulse.

Martin, A.D.

1986-05-09

295

Ultrasonic Time Reversal Mirrors  

NASA Astrophysics Data System (ADS)

For more than ten years, time reversal techniques have been developed in many different fields of applications including detection of defects in solids, underwater acoustics, room acoustics and also ultrasound medical imaging and therapy. The essential property that makes time reversed acoustics possible is that the underlying physical process of wave propagation would be unchanged if time were reversed. In a non dissipative medium, the equations governing the waves guarantee that for every burst of sound that diverges from a source there exists in theory a set of waves that would precisely retrace the path of the sound back to the source. If the source is pointlike, this allows focusing back on the source whatever the medium complexity. For this reason, time reversal represents a very powerful adaptive focusing technique for complex media. The generation of this reconverging wave can be achieved by using Time Reversal Mirrors (TRM). It is made of arrays of ultrasonic reversible piezoelectric transducers that can record the wavefield coming from the sources and send back its time-reversed version in the medium. It relies on the use of fully programmable multi-channel electronics. In this paper we present some applications of iterative time reversal mirrors to target detection in medical applications.

Fink, Mathias; Montaldo, Gabriel; Tanter, Mickael

2004-11-01

296

Time synchronized video systems  

NASA Astrophysics Data System (ADS)

The idea of synchronizing multiple video recordings to some type of 'range' time has been tried to varying degrees of success in the past. Combining this requirement with existing time code standards (SMPTE) and the new innovations in desktop multimedia however, have afforded an opportunity to increase the flexibility and usefulness of such efforts without adding costs over the traditional data recording and reduction systems. The concept described can use IRIG, GPS or a battery backed internal clock as the master time source. By converting that time source to Vertical Interval Time Code or Longitudinal Time Code, both in accordance with the SMPTE standards, the user will obtain a tape that contains machine/computer readable time code suitable for use with editing equipment that is available off-the-shelf. Accuracy on playback is then determined by the playback system chosen by the user. Accuracies of +/- 2 frames are common among inexpensive systems and complete frame accuracy is more a matter of the users' budget than the capability of the recording system.

Burnett, Ron

1994-05-01

297

RescueTime  

NSDL National Science Digital Library

Almost everyone has had the experience of stopping work for a quick email checkââ¾and losing an hour in the process. RescueTime is designed to help users become better at self-management of time by showing them where they spend the most time on the computer. Users can choose when to turn the application on, set goals and track progress towards them, and sign up to receive weekly email summaries of their productivity. This program is compatible with Windows, OS X, Linux, and Android operating systems.

2013-05-30

298

Einstein and His Times  

NSDL National Science Digital Library

In this lesson, students will read about and research the major historical events that occurred throughout the year 1919. They will use different readings and articles to understand and describe what life was like during this time. In addition, the students will present their case as to whether or not Albert Einstein should be voted "Man of the Year" for 1919. This activity is from the Cosmic Times teachers guide and is intended to be used in conjunction with the 1919 Cosmic Times Poster.

299

Epidemiological Methods: About Time  

PubMed Central

Epidemiological studies often produce false positive results due to use of statistical approaches that either ignore or distort time. The three time-related issues of focus in this discussion are: (1) cross-sectional vs. cohort studies, (2) statistical significance vs. public health significance, and (3), how risk factors “work together” to impact public health significance. The issue of time should be central to all thinking in epidemiology research, affecting sampling, measurement, design, analysis and, perhaps most important, the interpretation of results that might influence clinical and public-health decision-making and subsequent clinical research. PMID:20195431

Kraemer, Helena Chmura

2010-01-01

300

Paradoxes of time travel  

E-print Network

Paradoxes that can supposedly occur if a time machine is created are discussed. It is shown that the existence of trajectories of ``multiplicity zero'' (i.e. trajectories that describe a ball hitting its younger self so that the latter cannot fall into the time machine) is not paradoxical by itself. This {\\em apparent paradox} can be resolved (at least sometimes) without any harm to local physics or to the time machine. Also a simple model is adduced for which the absence of {\\em true} paradoxes caused by self-interaction is proved.

S. Krasnikov

1996-03-25

301

Understanding Geological Time  

NSDL National Science Digital Library

In this classroom activity, middle school students gain an understanding of geologic time. The activity opens with background information for teachers about carbon and radiometric dating. In a classroom discussion, students share what they know about geologic time. Then, working in small groups responsible for different eras, students create a timeline for their assigned era by conducting library and Internet research. The activity concludes by having students review all the timelines to compare how long humans have been on the Earth to the length of time dinosaurs inhabited the planet.

302

Systematically Controlling for the Influence of Age, Sex, Hertz and Time Post-Whole-Body Vibration Exposure on Four Measures of Physical Performance in Community-Dwelling Older Adults: A Randomized Cross-Over Study  

PubMed Central

Though popular, there is little agreement on what whole-body vibration (WBV) parameters will optimize performance. This study aimed to clarify the effects of age, sex, hertz and time on four physical function indicators in community-dwelling older adults (N = 32). Participants were exposed to 2?min WBV per session at either 2?Hz or 26?Hz and outcome measures were recorded at 2, 20 and 40?min post-WBV. Timed get up-and-go and chair sit-and-reach performances improved post-WBV for both sexes, were significantly different between 2?Hz and 26?Hz treatments (P ? 0.05) and showed statistically significant interactions between age and gender (P ? 0.01). Counter movement jump and timed one-legged stance performances showed a similar but non-significant response to 2?Hz and 26?Hz treatments, though male subjects showed a distinct trended response. Age and gender should be statistically controlled and both 2?Hz and 26?Hz exert a treatment effect. PMID:21977028

Merriman, Harold L.; Brahler, C. Jayne; Jackson, Kurt

2011-01-01

303

Time and Labor 9.1 Time Keeper -HCSD  

E-print Network

Time and Labor 9.1 Time Keeper - HCSD Version Date: July 2012 #12;COPYRIGHT & TRADEMARKS Copyright Guide Time Keeper - HCSD Page iii Table of Contents Time Keeper - HCSD........................................................................................................ 1 Time Sheet Overview

304

Drug Retention Times  

SciTech Connect

The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.

Center for Human Reliability Studies

2007-05-01

305

Drug Retention Times  

SciTech Connect

The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user

Center for Human Reliability Studies

2007-05-01

306

Drug Retention Times.  

National Technical Information Service (NTIS)

The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.

2007-01-01

307

Integration on time scales  

Microsoft Academic Search

In this paper we study the process of Riemann and Lebesgue integration on time scales. The relationship of the Riemann and Lebesgue integrals is considered and a criterion for Riemann integrability is established.

Gusein Sh. Guseinov

2003-01-01

308

Shape-Time Photography  

E-print Network

We introduce a new method to describe, in a single image, changes in shape over time. We acquire both range and image information with a stationary stereo camera. From the pictures taken, we display a composite image ...

Freeman, William T.

2002-01-10

309

Tsunami Travel Time Approximation  

NSDL National Science Digital Library

Eric Grosfils, Pomona College Summary Students are asked to calculate approximate tsunami travel times across the Pacific basin. The assignment builds off of a lab introducing students to Spatial Analyst, and ...

Grosfils, Eric

310

Time to Go Local!  

MedlinePLUS

... Bar Home Current Issue Past Issues Time to Go Local! Past Issues / Winter 2007 Table of Contents ... MedlinePlus.gov health topic pages, you will find "Go Local" links that take you to information about ...

311

GSA Geologic Time Scale  

NSDL National Science Digital Library

This Geological Society of America (GSA) site contains a detailed geologic time scale as an educational resource. It may be downloaded to a larger size, and includes all Eras, Eons, Periods, Epochs and ages as well as magnetic polarity information.

1999-01-01

312

"~-Winter Quarter Time Schedule  

E-print Network

Group Production Supervisor · Fran O'Connor Production Coordinator · Herb Payton Directors of National-time Student Requirement (veterans' benefits, Social Security benefits. international students ............................. : . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5 Athletic Events .............................................................. 5 Registration

Kaminsky, Werner

313

Mathematics, time, and confirmation  

E-print Network

This dissertation discusses two issues about abstract objects: their role in scientific theories, and their relation to time. Chapter 1, "Why Apply Mathematics?" argues that scientific theories are not about the mathematics ...

Meyer, Ulrich, 1968-

2001-01-01

314

Managing Time and Tasks.  

ERIC Educational Resources Information Center

Includes two articles that discuss time management and mail management strategies for librarians. Highlights include identifying personal work styles; planning and prioritizing; using calendars and computers; reexamining traffic patterns; delegating; and sorting and handling mail. (Contains eight references.) (LRW)

Handy, Alice Evans; Yucht, Alice H.

1993-01-01

315

TIME MANAGEMENT Other Handouts  

E-print Network

well, knowing what are your `time wasters' and what are your priorities and then minimizing the former efficiently. These are a diary (paper or electronic) a Murdoch University Principal dates wall calendar (buy

316

Timing control system  

NASA Technical Reports Server (NTRS)

A timing control system is disclosed which is particularly useful in connection with simulated mortar shells. Special circuitry is provided to assure that the shell does not overshoot, but rather detonates early in case of an improper condition; this ensures that ground personnel will not be harmed by a delayed detonation. The system responds to an externally applied frequency control code which is configured to avoid any confusion between different control modes. A premature detonation routine is entered in case an improper time-setting signal is entered, or if the shell is launched before completion of the time-setting sequence. Special provisions are also made for very early launch situations and improper detonator connections. An alternate abort mode is provided to discharge the internal power supply without a detonation in a manner that can be externally monitored, thereby providing a mechanism for non-destructive testing. The abort mode also accelerates the timing function for rapid testing.

Wiker, Gordon A. (Inventor); Wells, Jr., George H. (Inventor)

1989-01-01

317

Time Matters Cynthia Selin  

E-print Network

School Technology Scenarios Systems Analysis Department Risø National Laboratory #12;KEY THEMES IN PHD TimescapeTimescape Trajectories Disruptive/ Discontinuous Path Dependence Emerging Indeterminate #12;TIMEGovernance Trajectories Time as exponential Inevitable following of patterns Disruptive/ Discontinuous Path Dependence

318

Sublinear Time Algorithms  

E-print Network

Sublinear time algorithms represent a new paradigm in computing, where an algorithm must give some sort of an answer after inspecting only a very small portion of the input. We discuss the types of answers that one can ...

Rubinfeld, Ronitt

319

Kairoscope : coordinating time socially  

E-print Network

If everyone says time is relative, why is it still so rigidly defined? There have been many attempts to address the issue of coordinating schedules, but each of these attempts runs into an issue of rigidity: in order to ...

Martin, Reed Eric

2010-01-01

320

Time, energy & form  

E-print Network

Physical manifestations of time occur in natural forms of all sizes. Architectural form serves as shelter while providing a built envelope of human life, simultaneously influencing and influenced by energetic activities ...

McInnis, Martha Jane

1982-01-01

321

American Time Use Survey  

Cancer.gov

The American Time Use Survey (ATUS), conducted by the US Department of Labor, Bureau of Labor Statistics, is designed to collect information on how Americans spend their time on work, household chores, child care, recreation and other activities. The Applied Research Program (ARP) has provided funds to the US Department of Agriculture, Economic Research Service (USDA, ERS) to support the Eating and Health Module of the ATUS.

322

Classical Time Crystals  

E-print Network

We consider the possibility that classical dynamical systems display motion in their lowest energy state, forming a time analogue of crystalline spatial order. Challenges facing that idea are identified and overcome. We display arbitrary orbits of an angular variable as lowest-energy trajectories for nonsingular Lagrangian systems. Dynamics within orbits of broken symmetry provide a natural arena for formation of time crystals. We exhibit models of that kind, including a model with traveling density waves.

Alfred Shapere; Frank Wilczek

2012-02-12

323

TIMED Spacecraft Mobile  

NSDL National Science Digital Library

This is a mobile for learners to assemble, aimed at enhancing their knowledge of NASA spacecraft and scientific facts. Each hanging element of the mobile contains an image and one fact or scientific concept related to the TIMED (Thermosphere, Ionosphere, Mesosphere, Energetics, and Dynamics) spacecraft mission. The cover contains background information about NASA's TIMED mission and two language arts exercises to reinforce space science vocabulary.

324

Comprehending Geologic Time  

NSDL National Science Digital Library

You can use this calculator to create your own metaphor for geologic time. The history of the could be the the distance from your home to school - you can figure out where dinosaurs would be on the trip. Or the history of time could be the length of a class - and you could figure how much of the class you have to sit through before intelligence appears.

2008-02-07

325

Timing a Speedbot!  

NSDL National Science Digital Library

Students strengthen their communicate skills about measurements by learning the meaning of base units and derived units, including speedâone of the most common derived units (distance/time). Working in groups, students measure the time for LEGO® MINDSTORMS® NXT robots to move a certain distance. The robots are started and stopped via touch sensors and programmed to display the distance traveled. Using their collected data, students complete a worksheet to calculate the robots' (mean/average) speeds at given motor powers.

AMPS GK-12 Program,

326

Space and Time  

E-print Network

IIn the paper the Space-Time problem is considered as it seen in the informational conception ("the Information as Absolute" conception) comparing with a number of existent physical and philosophical approaches. Since the conception is rigorously grounded (for the conception the existence, the truth, the self-consistence and the completeness are proven), the notions "Space" and "Time" - which cannot be deduced from physics itself since are Meta-physical notions - obtain reasonable elucidation that is presented in the paper.

Sergey. V. Shevchenko; Vladimir. V. Tokarevsky

2011-09-30

327

On Time Versus Space  

Microsoft Academic Search

It is shown that every deterministic multitape Turing machine of time complexity t(n) can be simulated by a deterministic Turing machine of tape complexity t(n)\\/logt(n). Consequently, for tape constructable t(n), the class of languages recognizable by multitape Turing machines of time complexity t(n) is strictly contained in the class of languages recognized by Turing machines of tape complexity t(n). In

John E. Hopcroft; Wolfgang J. Paul; Leslie G. Valiant

1977-01-01

328

Time, Quantum and Information  

Microsoft Academic Search

Time, Quantum and Information, a paean to Professor Carl Friedrich von Weizsäcker, commemorates his 90th birthday. The range of Professor Weizsäcker's endeavours is an exhilarating example of what can be accomplished by one freely-soaring human spirit, who is at the same time a physicist, a philosopher, and a humanitarian.The editors, Lutz Castell and Otfried Ischebeck, have assembled an admirable collection

Leaf Turner

2004-01-01

329

Decay time of cathodoluminescence  

NASA Astrophysics Data System (ADS)

Simple measurements of the decay time of cathodoluminescence are described. Cathodoluminescence is used in many devices, including computer monitors, oscilloscopes, radar displays and television tubes. The experimental setup is simple and easy to build. Two oscilloscopes, a function generator, and a fast photodiode are needed for the experiments. The decay time determined using square wave and sine wave excitation of the phosphor appeared to be less than 10-4 s.

Kraftmakher, Yaakov

2009-01-01

330

The Los Angeles Times  

NSDL National Science Digital Library

The Los Angeles Times debuts its Internet edition April 8. It is slated to include daily news and features, coverage of movies and entertainment, a computers and technology section, a special section devoted to Southern California sights and events, classified advertising, and chat boards. The site will be free. A fee based site will also be available, with access to Times' archives, as well as educational and research services. http://www.latimes.com

331

Satellite time transfer  

Microsoft Academic Search

Different satellite time transfer techniques are described. One-way and two-way methods are presented. A more detailed description of different methods such as the global positioning system and time and frequency comparisons using TV-signals or pn-coded signals via communication satellites are outlined. In addition the use of laser signals (the Lasso experiment) is explained and the performance of the different techniques

D. Kirchner

1989-01-01

332

TechKnow Times  

NSDL National Science Digital Library

TechKnow Times(tm) specializes in selecting and synthesizing information about Internet resources. Its goal is to make information access as simple and as quick as possible. It covers news related to Internet and online marketing, World Wide Web sites and design, and online technology and culture, all drawn from a wide range of print and electronic sources. TechKnow Times(tm) is giving online entrepreneurs the information they need to accomplish their goals.

1996-01-01

333

GABA Predicts Time Perception  

PubMed Central

Our perception of time constrains our experience of the world and exerts a pivotal influence over a myriad array of cognitive and motor functions. There is emerging evidence that the perceived duration of subsecond intervals is driven by sensory-specific neural activity in human and nonhuman animals, but the mechanisms underlying individual differences in time perception remain elusive. We tested the hypothesis that elevated visual cortex GABA impairs the coding of particular visual stimuli, resulting in a dampening of visual processing and concomitant positive time-order error (relative underestimation) in the perceived duration of subsecond visual intervals. Participants completed psychophysical tasks measuring visual interval discrimination and temporal reproduction and we measured in vivo resting state GABA in visual cortex using magnetic resonance spectroscopy. Time-order error selectively correlated with GABA concentrations in visual cortex, with elevated GABA associated with a rightward horizontal shift in psychometric functions, reflecting a positive time-order error (relative underestimation). These results demonstrate anatomical, neurochemical, and task specificity and suggest that visual cortex GABA contributes to individual differences in time perception. PMID:24647956

Russo, Sonia; Near, Jamie; Stagg, Charlotte J.; Cohen Kadosh, Roi

2014-01-01

334

Fossils, rocks, and time  

USGS Publications Warehouse

We study out Earth for many reasons: to find water to drink or oil to run our cars or coal to heat our homes, to know where to expect earthquakes or landslides or floods, and to try to understand our natural surroundings. Earth is constantly changing--nothing on its surface is truly permanent. Rocks that are not on top of a mountain may once have been on the bottom of the sea. Thus, to understand the world we live on, we must add the dimension of time. We must study Earth's history. When we talk about recorded history, time is measured in years, centuries, and tens of centuries. When we talk about Earth history, time is measured in millions and billions of years. Time is an everyday part of our lives. We keep track of time with a marvelous invention, the calendar, which is based on the movements of the Earth in space. One spin of Earth on its axis is a day, and one trip around the sun is a year. The modern calendar is a great achievement, developed over many thousands of years as theory and technology improved. People who study Earth's history also use a type of calendar, called the geologic time scale. It looks very different from the familiar calendar. In some ways, it is more like a book, and the rocks are its pages. Some of the pages are torn or missing, and the pages are not numbered, but geology gives us the tools to help us read this book.

Edwards, Lucy E.; Pojeta, John, Jr.

1993-01-01

335

Fossils, rocks, and time  

USGS Publications Warehouse

We study our Earth for many reasons: to find water to drink or oil to run our cars or coal to heat our homes, to know where to expect earthquakes or landslides or floods, and to try to understand our natural surroundings. Earth is constantly changing--nothing on its surface is truly permanent. Rocks that are now on top of a mountain may once have been at the bottom of the sea. Thus, to understand the world we live on, we must add the dimension of time. We must study Earth's history. When we talk about recorded history, time is measured in years, centuries, and tens of centuries. When we talk about Earth history, time is measured in millions and billions of years. Time is an everyday part of our lives. We keep track of time with a marvelous invention, the calendar, which is based on the movements of Earth in space. One spin of Earth on its axis is a day, and one trip around the Sun is a year. The modern calendar is a great achievement, developed over many thousands of years as theory and technology improved. People who study Earth's history also use a type of calendar, called the geologic time scale. It looks very different from the familiar calendar. In some ways, it is more like a book, and the rocks are its pages. Some of the pages are torn or missing, and the pages are not numbered, but geology gives us the tools to help us read this book.

Edwards, Lucy E.; Pojeta, John

1999-01-01

336

Time-Distance Helioseismology  

NASA Technical Reports Server (NTRS)

Time-distance helioseismology is a method of ambient noise imaging using the solar oscillations. The basic realization that led to time-distance helioseismology was that the temporal cross correlation of the signals at two 'surface' (or photospheric) locations should show a feature at the time lag corresponding to the subsurface travel time between the locations. The temporal cross correlation, as a function of the location separation, is the Fourier transform of the spatio-temporal power spectrum of the solar oscillations, a commonly used function in helioseismology. It is therefore likely the characteristic ridge structure of the correlation function had been seen before without appreciation of its significance. Travel times are measured from the cross correlations. The times are sensitive to a number of important subsurface solar phenomena. These include sound speed variations, flows, and magnetic fields. There has been much interesting progress in the 17 years since the first paper on this subject (Duvall et al., Nature, 1993, 362, 430-432). This progress will be reviewed in this paper.

Duvall, Thomas L., Jr.

2010-01-01

337

Time dependent seismic hazard  

NASA Astrophysics Data System (ADS)

Probabilistic seismic hazard is usually computed trough a homogeneous Poisson process that even though it is a time-independent process it is widely used for its very convenient properties. However, when a single fault is of concern and/or the time scale is different from that of the long term, time-dependent processes are required. In this paper, different time-dependent models are reviewed with working examples. In fact, the Paganica fault (in central Italy) has been considered to compute both the probability of occurrence of at least one event in the lifespan of the structure, as well as the seismic hazard expressed in terms of probability of exceedance of an intensity value in a given time frame causing the collapse of the structure. Several models, well known or novel application to engineering hazard have been considered, limitation and issues in their applications are also discussed. The Brownian Passage Time (BPT) model is based on a stochastic modification of the deterministic stick-slip oscillator model for characteristic earthquakes; i.e., based on the addition of random perturbations (a Gaussian white noise) to the deterministic load path predicted by elastic rebound theory. This model assumes that the load state is at some ground level immediately after an event, increases steadly over time, reaches a failure threshold and relaxes instantaneously back to the ground level. For this model also a variable threshold has been considered to take into account the uncertainty of the threshold value. For the slip-predictable model it is assumed that the stress accumulates at a constant rate starting from some initial stress level. Stress is assumed to accumulate for a random period of time until an earthquake occurs. The size of the earthquake is governed by the stress release and it is a function of the elapsed time since the last event. In the time-predictable model stress buildup occurs at a constant rate until the accumulated stress reaches a threshold; then an earthquake occurs and a part of the accumulated stress is released. The renewal gamma assumes that the loading in the source has to go under a fixed number of steps to trigger an event. Moreover, because these models are hardly capable to capture earthquake clustering, ETAS models have been also investigated. Finally, after-shock occurrence has been considered and modeled with a more traditional non-homogeneous Poisson process.

Polidoro, B.; Iervolino, I.; Chioccarelli, E.; Giorgio, M.

2012-04-01

338

Discrete-Time Goldfishing  

NASA Astrophysics Data System (ADS)

The original continuous-time ''goldfish'' dynamical system is characterized by two neat formulas, the first of which provides the N Newtonian equations of motion of this dynamical system, while the second provides the solution of the corresponding initial-value problem. Several other, more general, solvable dynamical systems ''of goldfish type'' have been identified over time, featuring, in the right-hand (''forces'') side of their Newtonian equations of motion, in addition to other contributions, a velocity-dependent term such as that appearing in the right-hand side of the first formula mentioned above. The solvable character of these models allows detailed analyses of their behavior, which in some cases is quite remarkable (for instance isochronous or asymptotically isochronous). In this paper we introduce and discuss various discrete-time dynamical systems, which are as well solvable, which also display interesting behaviors (including isochrony and asymptotic isochrony) and which reduce to dynamical systems of goldfish type in the limit when the discrete-time independent variable l=0,1,2,... becomes the standard continuous-time independent variable t, 0?t

Calogero, Francesco

2011-08-01

339

Time-domain imaging  

NASA Technical Reports Server (NTRS)

The quest for the highest resolution microwave imaging and principle of time-domain imaging has been the primary motivation for recent developments in time-domain techniques. With the present technology, fast time varying signals can now be measured and recorded both in magnitude and in-phase. It has also enhanced our ability to extract relevant details concerning the scattering object. In the past, the interface of object geometry or shape for scattered signals has received substantial attention in radar technology. Various scattering theories were proposed to develop analytical solutions to this problem. Furthermore, the random inversion, frequency swept holography, and the synthetic radar imaging, have two things in common: (1) the physical optic far-field approximation, and (2) the utilization of channels as an extra physical dimension, were also advanced. Despite the inherent vectorial nature of electromagnetic waves, these scalar treatments have brought forth some promising results in practice with notable examples in subsurface and structure sounding. The development of time-domain techniques are studied through the theoretical aspects as well as experimental verification. The use of time-domain imaging for space robotic vision applications has been suggested.

Tolliver, C. L.

1989-01-01

340

Time and Labor 9.1 Time Keeper Payroll -HCSD  

E-print Network

Time and Labor 9.1 Time Keeper Payroll - HCSD Version Date: July 2012 #12;COPYRIGHT & TRADEMARKS Guide Time and Labor 9.1 Time Keeper Payroll - HCSD Page iii Table of Contents Time and Labor 9.1 Time Keeper Payroll - HCSDl.....................................................1 Time Sheet Overview

341

Kinesthetic Astronomy: Sky Time  

NSDL National Science Digital Library

This lesson teaches basic astronomical concepts such as the astronomical meaning of the day, year, and seasons through choreographed bodily movements and positions that provide educational sensory experiences. Through a series of simple body movements, students gain insight into the relationship between time and astronomical motions of Earth (rotation about its axis, and orbit around the Sun), and also about how these motions influence what we see in the sky at various times of the day and year. The lesson can be applied to understand the times of day and year on other planets (e.g. Mars). The lesson provides a set-up for understanding seasons and can be taught with or without an emphasis thereon.

Morrow, Cherilynn; Zawaski, Michael

342

Time rate collision matrix  

SciTech Connect

The collision integral terms in Boltzmann equation are reformulated numerically leading to the substitution of the multiple integrals with a multiplicative matrix of the two colliding species velocity distribution functions which varies with the differential collision cross section. A matrix of lower rank may be constructed when one of the distribution functions is specified, in which case the matrix elements represent kinetic transition probabilities in the velocity space and the multiplication of the time rate collision matrix with the unknown velocity distribution function expresses the time rate of change of the distribution. The collision matrix may be used to describe the time evolution of systems in nonequilibrium conditions, to evaluate the rate of momentum and energy transfer between given species, or to generate validity criteria for linearized kinetic equations.

Stoenescu, M.L.; Smith, T.M.

1980-02-01

343

Agency, time, and causality  

PubMed Central

Cognitive Scientists interested in causal cognition increasingly search for evidence from non-Western Educational Industrial Rich Democratic people but find only very few cross-cultural studies that specifically target causal cognition. This article suggests how information about causality can be retrieved from ethnographic monographs, specifically from ethnographies that discuss agency and concepts of time. Many apparent cultural differences with regard to causal cognition dissolve when cultural extensions of agency and personhood to non-humans are taken into account. At the same time considerable variability remains when we include notions of time, linearity and sequence. The article focuses on ethnographic case studies from Africa but provides a more general perspective on the role of ethnography in research on the diversity and universality of causal cognition.

Widlok, Thomas

2014-01-01

344

Real-Time Simulation  

NASA Technical Reports Server (NTRS)

Coryphaeus Software, founded in 1989 by former NASA electronic engineer Steve Lakowske, creates real-time 3D software. Designer's Workbench, the company flagship product, is a modeling and simulation tool for the development of both static and dynamic 3D databases. Other products soon followed. Activation, specifically designed for game developers, allows developers to play and test the 3D games before they commit to a target platform. Game publishers can shorten development time and prove the "playability" of the title, maximizing their chances of introducing a smash hit. Another product, EasyT, lets users create massive, realistic representation of Earth terrains that can be viewed and traversed in real time. Finally, EasyScene software control the actions among interactive objects within a virtual world. Coryphaeus products are used on Silican Graphics workstation and supercomputers to simulate real-world performance in synthetic environments. Customers include aerospace, aviation, architectural and engineering firms, game developers, and the entertainment industry.

1997-01-01

345

Activated clotting time (ACT).  

PubMed

The standard assay for monitoring anticoagulation during extracorporeal life support (ECLS) is the activated clotting time (ACT) test, with celite, kaolin, and glass beads being the most commonly used activators to initiate contact activation. The point-of-care ACT test has been the preferred test in catheterization labs and cardiac theatres because it has a number of advantages over laboratory tests (Spinler et al., Ann Pharmacother 39(7-8):1275-1285, 2005): Shorter time between sampling and results. Smaller blood sample size. Availability to have test performed by non-lab personnel. Reduced errors associated with sample mislabeling/mishandling. Decreased risk of sample degradation with time. There are other coagulation monitoring tests available; however these are usually specific and do not take into account the global picture of the entire clotting system. The standard coagulation tests (prothrombin time (PT), activated partial thromboplastin time, thrombin time (TT), and fibrinogen level) are plasma tests measuring plasma haemostasis and not patient haemostasis. The ACT measurement uses whole blood, thereby incorporating the importance of platelets and phospholipids in the role of coagulation. Many of the problems with the haemostatic system during ECLS are caused by the activation of platelets, which are not detected by standard tests. Because an ACT test is nonspecific there are many variables such as hypothermia, platelets, aprotinin, GP IIb/IIIa antagonists, haemodilution, etc. that can alter its results. For this reason it is important to gain an understanding as to how these variables interact for meaningful interpretation of the ACT test result. PMID:23546712

Horton, Stephen; Augustin, Simon

2013-01-01

346

Decoherence and time emergence  

E-print Network

In this work the possible role that Decoherence Model could play in the emergence of the classical concept of time is analyzed. We take the case of a Mixmaster universe with small anisotropy and construct its Halliwell propagator. Afterwards we introduce in our system terms that comprise the effects of Decoherence Model. This is done by means of the so called Restricted Path Integral Formalism. We obtain Halliwell's modified propagator and find that a gauge invariant physical time emerges as consequence of this process.

A. Camacho

1998-07-30

347

Quantum tunneling time  

E-print Network

A simple model of a quantum clock is applied to the old and controversial problem of how long a particle takes to tunnel through a quantum barrier. The model I employ has the advantage of yielding sensible results for energy eigenstates, and does not require the use of time-dependant wave packets. Although the treatment does not forbid superluminal tunneling velocities, there is no implication of faster-than-light signaling because only the transit duration is measurable, not the absolute time of transit. A comparison is given with the weak-measurement post-selection calculations of Steinberg.

P. C. W. Davies

2004-03-01

348

Clocks and Time  

E-print Network

A general definition of a clock is proposed, and the role of clocks in establishing temporal pre-conditions in quantum mechanical questions is critically discussed. The different status of clocks as used by theorists external to a system and as used by participant-observers within a system is emphasized. It is shown that the foliation of spacetime into instants of time is necessary to correctly interpret the readings of clocks and that clocks are thus insufficient to reconstruct time in the absence of such a foliation.

Arlen Anderson

1995-07-18

349

Interactive Telling Time Lite  

NSDL National Science Digital Library

This iOS app allows learners to practice reading both a digital and analog clock. Learners can choose between either "Set the Time" or "Stop the Clock" games. In the first game players move the hour and/or minute hand to show the target time. In the second game players stop the clock on the exact minute and hour described. Two versions of the clock are available in the lite version of the app. Additional clocks and games are available with upgrade to full version ($) of the app.

Ltd, Giggleup K.

2013-09-16

350

Time, Chance, and Reduction  

NASA Astrophysics Data System (ADS)

List of contributors; 1. Introduction Gerhard Ernst and Andreas Hütteman; Part I. The Arrows of Time: 2. Does a low-entropy constraint prevent us from influencing the past? Mathias Frisch; 3. The part hypothesis meets gravity Craig Callender; 4. Quantum gravity and the arrow of time Claus Kiefer; Part II. Probability and Chance: 5. The natural-range conception of probability Jacob Rosenthal; 6. Probability in Boltzmannian statistical mechanics Roman Frigg; 7. Humean mechanics versus a metaphysics of powers Michael Esfeld; Part III. Reduction: 8. The crystallisation of Clausius's phenomenological thermodynamics C. Ulises Moulines; 9. Reduction and renormalization Robert W. Batterman; 10. Irreversibility in stochastic dynamics Jos Uffink; Index.

Ernst, Gerhard; Hüttemann, Andreas

2010-01-01

351

New York Times: Circuits  

NSDL National Science Digital Library

Circuits is a new New York Times weekly offering intended to enhance the newspaper's technology coverage. It contains regular gaming and computer columns, along with an eclectic mix of articles and essays that address in a general way the interaction between humans and technology. The first three issues contained articles on where computers go to die, music and jobs on the web, computer games for girls, online auctions, home theatre, web TV, and computer ergonomics, among others. At present, Circuit archives are available. Note that the New York Times is freely available (after required registration) to users in the US.

1998-01-01

352

The Geologic Time Scale  

NSDL National Science Digital Library

This site contains a large, easy to read, detailed geologic time scale for the Phanerozoic Eon (544 million years ago - Present). This is the period of time, also known as an eon, between the end of the Precambrian and today. The Phanerozoic begins with the start of the Cambrian period, 544 million years ago. It encompasses the period of abundant, complex life on Earth. The chart includes the Era, Period or System, and the Epoch or Series and features a brief description of each.

353

Sky Time: Kinesthetic Astronomy  

NSDL National Science Digital Library

Through a series of simple body movements, learners gain insight into the relationship between time and astronomical motions of Earth (rotation about its axis, and orbit around the Sun), and also about how these motions influence what we see in the sky at various times of the day and year. This activity can be used to introduce seasons on Earth and other planets. Learners will especially enjoy finding their birthdays in the orbit and using a zodiac diagram. This comprehensive lesson plan includes detailed background information, common misconceptions, extensions, teacher tips, references/resources, and FAQs.

Morrow, Cherilynn A.; Zawaski, Michael

2004-01-01

354

Times for interplanetary trips  

NASA Technical Reports Server (NTRS)

The times required to travel to the various planets at an acceleration of one g are calculated. Surrounding gravitational fields are neglected except for a relatively short distance near take-off or landing. The orbit consists of an essentially straight line with the thrust directed toward the destination up to the halfway point, but in the opposite direction for the remainder so that the velocity is zero on arrival. A table lists the approximate times required, and also the maximum velocities acquired in light units v/c for the various planets.

Jones, R. T.

1976-01-01

355

The fire next time  

Microsoft Academic Search

Rodney King's beating by Los Angeles Police Department officers, and their subsequent acquittal by an all White jury sparked the first “multicultural riot” in Los Angeles in 1992. Twenty years since the time of the uprising, the vigilante murder of teenager Trayvon Martin in a gated community in Florida brought thousands across the country into the streets to protest the

Jenna M. Loyd

2012-01-01

356

TIME.SCHEDULE , PREREGISTRATION  

E-print Network

-PERSON REGISTRATION (By AppointmelJ.t Only) December 27, 30, 31 ~ !, » >ThiS. symbol.. in th~.. margin of. the TimeC:'. 201).800 level Mathematics, 100 level Initltutll for Comparative lind Forelsn Area Studies ~ .0:: i

Kaminsky, Werner

357

This Time It's Personal  

ERIC Educational Resources Information Center

Educators have known for some time now that a one-size-fits-all approach to learning does not lead to the level of student engagement and academic success that schools strive to achieve. In their search for a more customized approach to delivering instruction, they've explored project-based learning, addressed different learning styles, and…

Demski, Jennifer

2012-01-01

358

Early Time STARFISH Calculations.  

National Technical Information Service (NTIS)

In this report, we present results from recent CMHD (Collisionless Magnetohydrodynamics) code calculations of the early time (0 to 1 sec.) evolution of the STARFISH event. The emphasis of this report is on the velocity spectrum of the energy going to the ...

F. E. Fajen, R. W. Kilb

1982-01-01

359

Reaction Time Sound Explanation  

NSDL National Science Digital Library

This experiment presents auditory stimuli and requires the participant to respond after hearing target stimuli under different conditions. This experiment gives students the opportunity to determine whether their reaction times are reliably different for tasks that require slightly different decisions. This page provides guidance for faculty who wish to incorporate this activity into their classroom.

360

Geological Time Machine  

NSDL National Science Digital Library

This University of California site provides an interactive geologic time scale to explore the history of the Earth. Beginning in the Precambrian Eon (4.6 million years ago) and ending today (Holocene Epoch), each Epoch, Period, Era, and Eon are covered. Information provided includes ancient life, dates, descriptions of major events, localities, tectonics, and stratigraphy. Links to additional resources are also available.

Collins, Allen

361

Ordinal time series analysis  

Microsoft Academic Search

We discuss robust methods of time series analysis which use only comparisons of values and not their actual size. Local and global order structure are defined as matrices or by rank numbers. Local ranks, autocorrelation by Kendall’s tau, and permutation entropy as complexity measure are introduced in such a way that they contain a scale parameter which allows to study

Christoph Bandt

2005-01-01

362

Sound Image of Time  

Microsoft Academic Search

It is said that music begins where words fail. Music's vague messages awaken cloud-like feeling—idiosyncratic, and yet direct and precise in its animalistic power. The delicate beauty of the art of music would wither long time ago if not the mighty physiological element that the sound flow of music elicits from us, s haking, making shivers, affecting heartbeat, and giving

J. L. Borges

2007-01-01

363

A Moment in Time  

ERIC Educational Resources Information Center

There is a growing literature on the disappearance of the traditional model of higher education. Fewer courses are taught now than was the case just a few years ago by a full-time, permanent instructor in a single location, to students that the instructor has actually met in person. Another very real threat to the range of education is the growing…

Lonergan, David

2013-01-01

364

Real-time sonography  

SciTech Connect

This textbook acquaints the reader with normal and pathologic anatomy as depicted on dynamic or real-time scanning. Chapters are organized by specialty, such as abdominal, urologic, or pediatric. The text is illustrated with still-frame images and line drawings. The drawings show important areas of interest and provide graphic notation as to where and in what orientation the scan was obtained.

Fleischey, A.C.; James, A.E. Jr.

1984-01-01

365

More Time To Teach.  

ERIC Educational Resources Information Center

This report discusses increasing demands on teachers' time, particularly with more students with disabilities in regular education classes, and describes how teachers can use strategies, routines, and support systems to empower students to become more independent and more responsible for their own learning and study. The five underlying principles…

Goor, Mark B.; Schwenn, John O.

366

Space-time counterfactuals  

E-print Network

A definition is proposed to give precise meaning to the counterfactual statements that often appear in discussions of the implications of quantum mechanics. Of particular interest are counterfactual statements which involve events occurring at space-like separated points, which do not have an absolute time ordering. Some consequences of this definition are discussed.

J. Finkelstein

1998-11-21

367

Leadership in Challenging Times  

ERIC Educational Resources Information Center

In spite of tough financial times, resourceful school leaders devise ways to overcome challenges and improve education. To do this, they make strategic use of the resources they have. And they also cultivate learning communities. In this article, Elizabeth A. City describes how school leaders can make more strategic use of three essential…

City, Elizabeth A.

2013-01-01

368

On Space and Time  

NASA Astrophysics Data System (ADS)

Preface; 1. The dark universe A. N. Taylor; 2. Quantum spacetime and physical reality S. Majid; 3. Causality, quantum theory and cosmology R. Penrose; 4. On the fine structure of spacetime A. Connes; 5. Where physics meets metaphysics M. Heller; 6. The nature of time J. C. Polkinghorne; Index.

Majid, Shahn; Connes, With contributions by Alain; Heller, Michael; Penrose, Roger; Polkinghorne, John; Taylor, Andrew

2008-09-01

369

On Space and Time  

NASA Astrophysics Data System (ADS)

Preface; 1. The dark universe A. N. Taylor; 2. Quantum spacetime and physical reality S. Majid; 3. Causality, quantum theory and cosmology R. Penrose; 4. On the fine structure of spacetime A. Connes; 5. Where physics meets metaphysics M. Heller; 6. The nature of time J. C. Polkinghorne; Index.

Majid, Shahn; Polkinghorne, With contributions by John; Penrose, Roger; Taylor, Andrew; Connes, Alain; Heller, Michael

2012-03-01

370

Time and Moral Judgment  

ERIC Educational Resources Information Center

Do moral judgments hinge on the time available to render them? According to a recent dual-process model of moral judgment, moral dilemmas that engage emotional processes are likely to result in fast deontological gut reactions. In contrast, consequentialist responses that tot up lives saved and lost in response to such dilemmas would require…

Suter, Renata S.; Hertwig, Ralph

2011-01-01

371

Time intervals between accidents  

Microsoft Academic Search

Much of the evidence in favor of the commonly accepted hypothesis of individual differences in accident proneness of individuals is not affected by accidents in which they are involved. The validity of this assumption is investigated in terms of a study of time intervals between consecutive accidents of a number of taxi-drivers. Some features of the relevant mathematical theory of

Alexander Mintz

1954-01-01

372

Test of time  

Microsoft Academic Search

The test of time is not appropriate when “red flag” symptoms warrant immediate referral, but it can be helpful in patients presenting with common problems, such as diarrhoea (doi: 10.1136\\/bmj.b1877), that have a known clinical course

Susanna C Almond; Nick Summerton

2009-01-01

373

The First Time  

ERIC Educational Resources Information Center

In this article, the author narrates her experience of meeting a Montessori kid for the first time and shares the characteristics she observed in Montessori students. The author was working as director of academic resources in university housing at the University of Wisconsin-Madison and met Jason, a pre-med sophomore who was the resident…

Black, Beth

2011-01-01

374

Video time encoding machines.  

PubMed

We investigate architectures for time encoding and time decoding of visual stimuli such as natural and synthetic video streams (movies, animation). The architecture for time encoding is akin to models of the early visual system. It consists of a bank of filters in cascade with single-input multi-output neural circuits. Neuron firing is based on either a threshold-and-fire or an integrate-and-fire spiking mechanism with feedback. We show that analog information is represented by the neural circuits as projections on a set of band-limited functions determined by the spike sequence. Under Nyquist-type and frame conditions, the encoded signal can be recovered from these projections with arbitrary precision. For the video time encoding machine architecture, we demonstrate that band-limited video streams of finite energy can be faithfully recovered from the spike trains and provide a stable algorithm for perfect recovery. The key condition for recovery calls for the number of neurons in the population to be above a threshold value. PMID:21296708

Lazar, Aurel A; Pnevmatikakis, Eftychios A

2011-03-01

375

Expected residence time model  

Microsoft Academic Search

The Transportation Technology Department of Sandia National Laboratories develops analytical and computational tools for the US Department of Energy to assess the radiological consequences and risks from the transportation of radioactive materials by all modes. When large quantities of materials are to be transported movements may occur over an extended period of time in what is collectively referred as a

J. D. Smith; K. S. Neuhauser; F. L. Kanipe

1996-01-01

376

Branching time temporal logic  

Microsoft Academic Search

Many important parallel computer programs exhibit ongoing behaviour that is characterized naturally in terms of infinite execution traces, which can be organized into branching trees, and which reflect the high degree of nondeterminism inherent in parallel computation. In this paper, we give a systematic account of Branching Time Temporal Logics, which provide a formal system for describing and reasoning about

E. Allen Emerson; Jai Srinivasan

1988-01-01

377

Quaternion Dynamic Time Warping  

Microsoft Academic Search

Dynamic time warping (DTW) is used for the comparison and processing of nonlinear signals and constitutes a widely researched field of study. The method has been initially designed for, and applied to, signals representing audio data. Afterwords it has been successfully modified and applied to many other fields of study. In this paper, we present the results of researches on

Bartosz Jablonski

2012-01-01

378

Video Time Encoding Machines  

PubMed Central

We investigate architectures for time encoding and time decoding of visual stimuli such as natural and synthetic video streams (movies, animation). The architecture for time encoding is akin to models of the early visual system. It consists of a bank of filters in cascade with single-input multi-output neural circuits. Neuron firing is based on either a threshold-and-fire or an integrate-and-fire spiking mechanism with feedback. We show that analog information is represented by the neural circuits as projections on a set of band-limited functions determined by the spike sequence. Under Nyquist-type and frame conditions, the encoded signal can be recovered from these projections with arbitrary precision. For the video time encoding machine architecture, we demonstrate that band-limited video streams of finite energy can be faithfully recovered from the spike trains and provide a stable algorithm for perfect recovery. The key condition for recovery calls for the number of neurons in the population to be above a threshold value. PMID:21296708

Lazar, Aurel A.; Pnevmatikakis, Eftychios A.

2013-01-01

379

Dealing with time pressure  

Microsoft Academic Search

A sample of 250 people completed a questionnaire where they rated 30 statements describing their behavior and experiences during a recent time pressure situation. A factor analysis resulted in three factors: Personal Burden, Work Problems and Difficulties, and Challenge Orientation. People high on this last factor liked the excitement of being under pressure, were very absorbed in the task, and

Robert S. Lee; Patricia McGrath

1995-01-01

380

Where in Time?  

ERIC Educational Resources Information Center

In this article, the authors describe an activity developed to assist students with constructing their own understanding of Earth's history and provide questions to help teach the geologic time scale. The lesson is aligned to the following National Science Education Standards: Science as Inquiry, Earth's History, and Nature of Science. While…

Pecore, John; Sacks, David

2005-01-01

381

The time travel paradox  

E-print Network

We define the time travel paradox in physical terms and prove its existence by constructing an explicit example. We argue further that in theories -- such as general relativity -- where the spacetime geometry is subject to nothing but differential equations and initial data no paradoxes arise.

S. Krasnikov

2001-09-10

382

Time Sequence Liquid Dominant  

E-print Network

Time Sequence Liquid Dominant Evaporation De-pinning Dryout Progress Formation of Nanoparticle of Nanofluid Droplets on a Microheater Array 2-nm Au 20nm 47-nm Al2O3 Distilled Water 30-nm CuO Microheater to examine the effect of nanoparticle sizes on the dryout characteristics. While the distilled water droplet

Kihm, IconKenneth David

383

Fossils, Rocks, and Time  

NSDL National Science Digital Library

This on-line book, published by the United States Geological Survey (USGS), discusses the use of fossils in determining the age of rocks. The publication covers how to place events in correct temporal order, a description of the geologic time scale, the use of fossils to indicate rock ages, the law of fossil succession, index fossils, and radioactive dating.

Edwards, Lucy E.; Pojeta Jr., John

1997-06-26

384

Space-time diagrammatics  

NASA Astrophysics Data System (ADS)

We introduce a new class of two-dimensional diagrams, the projection diagrams, as a tool to visualize the global structure of space-times. We construct the diagrams for several metrics of interest, including the Kerr-Newman-(anti)de Sitter family, with or without cosmological constant, and the Emparan-Reall black rings.

Chru?ciel, Piotr T.; Ölz, Christa R.; Szybka, Sebastian J.

2012-12-01

385

Geologic time scale bookmark  

USGS Publications Warehouse

This bookmark, designed for use with U.S. Geological Survey activities at the 2nd USA Science and Engineering Festival (April 26–29, 2012), is adapted from the more detailed Fact Sheet 2010–3059 "Divisions of Geologic Time." The information that it presents is widely sought by educators and students.

U.S. Geological Survey

2012-01-01

386

Time reversal communication system  

SciTech Connect

A system of transmitting a signal through a channel medium comprises digitizing the signal, time-reversing the digitized signal, and transmitting the signal through the channel medium. The channel medium may be air, earth, water, tissue, metal, and/or non-metal.

Candy, James V. (Danville, CA); Meyer, Alan W. (Danville, CA)

2008-12-02

387

Hard Times Hit Schools  

ERIC Educational Resources Information Center

Hard-to-grasp dollar amounts are forcing real cuts in K-12 education at a time when the cost of fueling buses and providing school lunches is increasing and the demands of the federal No Child Left Behind Act still loom larger over states and districts. "One of the real challenges is to continue progress in light of the economy," said Gale Gaines,…

McNeil, Michele

2008-01-01

388

TIME PROJECT: AN OVERVIEW  

EPA Science Inventory

The TIME (Temporally Integrated Monitoring of Ecosystems) project has been in the conceptual and design stage for approximately two years. elays in implementation have allowed careful attention to many aspects of network design not usually covered prior to field implementation. h...

389

EXPLORING TIME USE  

Microsoft Academic Search

Usage of technologies, it has been argued, creates social and political malaise. Television was perceived to be the first culprit and it seems that the internet is being dubbed as the ‘new television’. As such, this paper focuses on the relationship between internet usage and time spent with friends and family, as well as other associational activities. A secondary concern

Paul Stoneman

2008-01-01

390

A Theory of Timed Automata  

Microsoft Academic Search

 We propose timed (finite) automata to model the behavior of realtime systems over time. Our definition provides a simple, and yet powerful, way to annotate state-transition graphs with timing constraints using finitely many realvalued clocks . A timed automaton accepts timed words --- infinite sequences in which a real-valued time of occurrence is associated with each symbol. We study timed

Rajeev Alur

1994-01-01

391

Funding Full-Time Study through Part-Time Work  

ERIC Educational Resources Information Center

Full-time students engaged in part-time studies have been a subject of increasing academic attention. This study extends work in this area by examining: the extent to which full-time undergraduate students undertake part-time employment, the reasons for working whilst studying full-time and the extent to which students relate their part-time

Richardson, Mark; Evans, Carl; Gbadamosi, Gbolahan

2009-01-01

392

Toward Accurate Dynamic Time Warping in Linear Time and Space  

E-print Network

1 Toward Accurate Dynamic Time Warping in Linear Time and Space Stan Salvador General Dynamics1 Institute of Technology ABSTRACT Dynamic Time Warping (DTW) has a quadratic time and space complexity warping algorithm that has a linear time and space complexity, and can find a warp path between two time

Chan, Philip K.

393

Timing is Everything  

SciTech Connect

You want to be ahead of the curve, but not so far ahead that no one can see you. Historically, the scientific community has tended to ignore science that is too innovative or ahead of its time. For this, we are often accused of being biased towards maintaining some fictional status quo. The reason these papers often get forgotten, however, has more to do with the usability of innovative ideas, rather than some perverseness. The classic case is Mendel, whose pioneering ideas on inheritance were ignored for many years. It wasn’t because the scientific community did not know about him; Mendel simply addressed different questions than other scientists at the time. Years later, when chromosomes were identified as a potential mechanism for transmitting genetic information, his ideas suddenly became relevant to a much wider scientific audience.

Wiley, H. S.

2009-08-01

394

"Maxim"izing time.  

PubMed

"You have to live on this 24 hours of daily time. Out of it you have to spin wealth, pleasure, money, content, respect, and the evolution of your immortal soul. Its right use, its most effective use, is a matter of the highest urgency...all depends on that."--Arnold Bennett The items presented here are not meant to contain all the answers to your time management challenges. However, these thoughts should spark your thinking process. Take these ideas, turn them over in your mind, play with them, develop your own thoughts on the subject, and force yourself to become more effective, more efficient, and more systematic. Acquiring this discipline now will ensure the most efficient path to your life's dreams. PMID:10143168

Merck, W R

1995-01-01

395

Time warp football  

Microsoft Academic Search

We describe a system called Time Warp Football (TWF) which puts fans in control of the game watching experience. TWF uses annotated video streams to enable instantaneous forward and backward play-by-play navigation and on-demand switching between multiple camera angles. These features allow fans to easily watch and re-watch plays they are interested in from any camera angle. The annotations also

Stephen G. Lynn; Brett G. Partridge

2009-01-01

396

A Journey Through Time  

NSDL National Science Digital Library

This activity has students create a travel brochure of a geologic period. Links are provided to research questions about the dominant life forms, position of the continents, and climate of the period. Questions in the conclusion section are for students to consider the duration of human existence compared to geologic time, why dinosaurs and humans never fought, and whether they would want to travel to their chosen geologic period.

Schneider, Amy

397

TIMED Spacecraft Model  

NSDL National Science Digital Library

This is a model for students to assemble, aimed at enhancing their knowledge of NASA spacecraft and scientific facts. The cover of this four-color tri-fold contains background information about the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) mission as well as two language arts activities to reinforce space science vocabulary and concepts. This product is available in hardcopy and electronic formats.

2001-06-01

398

Reaction Time 2: Zap!  

NSDL National Science Digital Library

This Science NetLinks lesson is the second of a two-part series that encourages students to think about their own learning and the strategies that best help them learn new skills and ideas. In this lesson, students build upon what they have already learned by participating in another online reaction-time activity--this one testing their visual and auditory abilities, both separately and together.

Science Netlinks;

2003-06-19

399

Music in Galileo's Time  

NASA Astrophysics Data System (ADS)

Claudio Monteverdi appears as the key personality of the music in Galileo's time. His revolution in format and function of the musical language-from an essentially edonistic creation of purely sonorous images to a musical language consciously "expressive" of the content of the words on which it is based-is similar in character to the influential innovations in scientific thinking operated by Galileo.

Petrobelli, P.

2011-06-01

400

Einstein in Time  

NSDL National Science Digital Library

This fun Web site is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here, they are introduced to Einstein's scientific and humanitarian pursuits with two engaging, kid-friendly sections: Einstein in Time, a fascinating look at the major events in his life presented in a timeline and Everyday Einstein: Humanitarian, a quick overview of how he used his fame to draw attention to the things he believed in.

401

Timing in retroactive interference  

Microsoft Academic Search

Retroactive interference is conventionally viewed as attenuated retrieval of a target association due to the training of a\\u000a second association between training and testing of the target association. In three experiments in which water-deprived rats\\u000a were used as subjects, we manipulated the durations of the time between cue termination and outcome onset (Experiment 1),\\u000a the durations of the target and

Martha Escobar; Ralph R. Miller

2003-01-01

402

Timing, Remembering, and Discrimination  

ERIC Educational Resources Information Center

Four pigeons were first trained in a timing procedure. In one condition, each trial began with the presentation of an X on the center key, followed by a delay (short or long), after which two side keys were lit. If the delay was short, pecks to the red side key were reinforced. If the delay was long, pecks to the green side key were reinforced. In…

Sargisson, Rebecca J.; White, K. Geoffrey

2007-01-01

403

Metrology and Time  

E-print Network

The algorithm Pi/sinx reveals an elliptic excess which acts as the real component (Space) inducing the imaginary component (Time). Key words : metrology, chronogenesis, tropic year, anomalistic year. ----- L 'algorithme Pi/sinx revele un excedent elliptique constituant la composante active d ' espace dont la composante reactive exprime la chronogenese tropique aussi bien qu ' anomalistique.. Mots-cles : metrologie, chronogenese, annee tropique, annee anomalistique

Boris Rybak

2000-05-03

404

Entropy and relaxation time  

E-print Network

This paper discusses the possible relation between entropy and the relaxation time of liquids, in particular glass-forming systems, providing supplementing comments to the paper entitled "A brief critique of the Adam-Gibbs entropy model" by Hecksher et al. [J. Non-Cryst. Solids 325, 624-627 (2009)]. Besides the Adam-Gibbs model, we also briefly discuss Rosenfeld's excess entropy scaling and the 1964 experimental observation by Chang and Bestul of a universal excess entropy at the glass transition.

Jeppe C. Dyre

2014-03-11

405

Interaction in musical time  

E-print Network

. . . . . . . . . . . . . . . . . . . 152 6.8 Group entrainment . . . . . . . . . . . . . . . . . . . . . . . . 154 6.8.1 Phase conversion: Hilbert transform . . . . . . . . . . 154 6.8.2 Kuramoto model . . . . . . . . . . . . . . . . . . . . . 155 6.9 Summary - analysing interaction... (1966)1.1 Setting the stage After learning to sit straight and locating the middle C, a young, aspiring pianist will need to learn two timing skills that are crucial for any music performance. One is the ability to internalise a regular beat, a pulse...

Himberg, Tommi

2014-03-04

406

Differential entropy and time  

Microsoft Academic Search

We give a detailed analysis of the Gibbs-type entropy notion and its dynamical behavior in case of time-dependent continuous probability distributions of varied origins: related to classical and quantum systems. The purpose-dependent usage of conditional Kullback-Leibler and Gibbs (Shannon) entropies is explained in case of non-equilibrium Smoluchowski processes. A very different temporal behavior of Gibbs and Kullback entropies is confronted.

Piotr Garbaczewski

2005-01-01

407

Swing in Time  

NSDL National Science Digital Library

Learners build and investigate pendulums of different lengths. They discover that the longer the string of the pendulum, the longer the time it takes to swing. Learners also discover that changing the mass on the end of the pendulum and changing the angle of release of the pendulum do not affect how long it takes to swing. Resource contains suggestions for assessment, extensions, and scaling for different levels of learners.

Duren, Sabre; Heavner, Ben; Zarske, Malinda S.; Carlson, Denise

2004-01-01

408

The sun in time  

SciTech Connect

Various papers on solar science are presented. The topics considered include: variability of solar irradiance, sunspot number, solar diameter, and solar wind properties; theory of luminosity and radius variations; standard solar models; the sun and the IMF; variations of cosmic-ray flux with time; accelerated particles in solar flares; solar cosmic ray fluxes during the last 10 million yrs; solar neutrinos and solar history; time variations of Be-10 and solar activity; solar and terrestrial components of the atmospheric C-14 variation spectrum; solar flare heavy-ion tracks in extraterrestrial objects. Also addressed are: the faint young sun problem; atmospheric responses to solar irradiation; quaternary glaciations; solar-terrestrial relationships in recent sea sediments; magnetic history of the sun; pre- and main-sequence evolution of solar activity; magnetic activity in pre-main-sequence stars; classical T Tauri stars; relict magnetism of meteorites; luminosity variability of solar-type stars; evolution of angular momentum in solar-mass stars; time evolution of magnetic fields on solarlike stars.

Sonett, C.P.; Giampapa, M.S.; Matthews, M.S. (Arizona, University, Tucson (United States) National Optical Astronomy Observatories, Tuscon (United States))

1991-01-01

409

Timing HU Aqr  

NASA Astrophysics Data System (ADS)

We report XMM-Newton X-ray and ultraviolet observations of the bright eclipsing polar HU Aqr performed in October 2013. When discovered in the RASS, it was the brightest eclipsing AM Her star but in the XMM-Newton era it was encountered in low or intermediate states only. After recovery into a high state a triggered Swift/XMM-Newton accompanied by ground-based photometry could be arranged. The X-ray observations covered 5 orbital cycles of the 125min binary. The object was extremely bright at soft X-rays reaching >150 cts/s in 1s time bins. The X-ray light curve was found to be highly structured featuring an opaque accretion stream and a porous accretion curtain. We will present a multi-wavelength timing study to locate the X-ray emission region and determine its size. The relative timing of optical and X-ray eclipses and the use of either data searching for circumbinary planets via the Roemer delay is discussed.

Schwope, A.; Traulsen, I.; Hessman, F.; Thinius, B.; Walter, F.; Schwarz, R.; Reinsch, K.; Burwitz, V.

2014-07-01

410

Real-Time PCR  

NASA Astrophysics Data System (ADS)

Over the past few years there has been a considerable development of DNA amplification by polymerase chain reaction (PCR), and real-time PCR has now superseded conventional PCR techniques in many areas, e.g., the quantification of nucleic acids and genotyping. This new approach is based on the detection and quantification of a fluorescent signal proportional to the amount of amplicons generated by PCR. Real-time detection is achieved by coupling a thermocycler with a fluorimeter. This chapter discusses the general principles of quantitative real-time PCR, the different steps involved in implementing the technique, and some examples of applications in medicine. The polymerase chain reaction (PCR) provides a way of obtaining a large number of copies of a double-stranded DNA fragment of known sequence. This DNA amplification technique, developed in 1985 by K. Mullis (Cetus Corporation), saw a spectacular development over the space of a few years, revolutionising the methods used up to then in molecular biology. Indeed, PCR has many applications, such as the detection of small amounts of DNA, cloning, and quantitative analysis (assaying), each of which will be discussed further below.

Evrard, A.; Boulle, N.; Lutfalla, G. S.

411

Time Reversal Violation  

SciTech Connect

This talk briefly reviews three types of time-asymmetry in physics, which I classify as universal, macroscopic and microscopic. Most of the talk is focused on the latter, namely the violation of T-reversal invariance in particle physics theories. In sum tests of microscopic T-invariance, or observations of its violation, are limited by the fact that, while we can measure many processes, only in very few cases can we construct a matched pair of process and inverse process and observe it with sufficient sensitivity to make a test. In both the cases discussed here we can achieve an observable T violation making use of flavor tagging, and in the second case also using the quantum properties of an antisymmetric coherent state of two B mesons to construct a CP-tag. Both these tagging properties depend only on very general properties of the flavor and/or CP quantum numbers and so provide model independent tests for T-invariance violations. The microscopic laws of physics are very close to T-symmetric. There are small effects that give CP- and T-violating processes in three-generation-probing weak decays. Where a T-violating observable can be constructed we see the relationships between T-violation and CP-violation expected in a CPT conserving theory. These microscopic effects are unrelated to the 'arrow of time' that is defined by increasing entropy, or in the time direction defined by the expansion of our Universe.

Quinn, H; /SLAC

2009-01-27

412

Commission 31: Time  

NASA Astrophysics Data System (ADS)

The most intensely discussed and controversial issue in time keeping has been the proposal before the International Telecommunications Union (ITU) to redefine Coordinated Universal Time (UTC) so as to replace leap seconds by leap hours. Should this proposal be adopted, the practice of inserting leap seconds would cease after a specific date. Should the Earth's rotation continue to de-accelerate at its historical rate, the next discontinuity in UTC would be an hour inserted several centuries from now. Advocates of this proposal cite the need to synchronize satellite and other systems, such as GPS, Galileo, and GLONASS, which did not exist and were not envisioned when the current system was adopted. They note that leap second insertions can be and have been incorrectly implemented or accounted for. Such errors have to date had localized impact, but they could cause serious mishaps involving loss of life. For example, some GPS receivers have been known to fail simply because there was no leap second after a long enough interval, other GPS receivers failed because the leap second information was broadcast more than three months in advance, and some commercial software used for internet time-transfer Network Time Protocol (NTP) could either discard all data received after a leap second or interpret it as a frequency change. The ambiguity associated with the extra second could also disrupt financial accounting and certain forms of encryption. Those opposed to the proposal question the need for a change, and also point out the costs of adjusting to the proposed change and its inconvenience to amateur astronomers and others who rely upon astronomical calculations published in advance. Reports have been circulated that the cost of checking and correcting software to accommodate the new definition of UTC would be many millions of dollars for some systems. In October 2005 American Astronomical Society asked the ITU for a year's time to study the issue. This commission has supported the efforts of the IAU' s Committee on the Leap Second to make an informed recommendation, and anticipates considerable discussion at the IAU's 26th General Assembly in 2006.

Matsakis, Demetrios; Defraigne, Pascale; Hosokawa, M.; Leschiutta, S.; Petit, G.; Zhai, Z.-C.

2007-03-01

413

Reactor control rod timing system  

Microsoft Academic Search

A fluid driven jet-edge whistle timing system for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod

Peter T. K

1982-01-01

414

Are animals stuck in time?  

Microsoft Academic Search

People can time travel cognitively because they can remember events having occurred at particular times in the past (episodic memory) and because they can anticipate new events occurring at particular times in the future. The ability to assign points in time to events arises from human development of a sense of time and its accompanying time-keeping technology. The hypothesis is

William A. Roberts

2002-01-01

415

Principles of Discrete Time Mechanics  

NASA Astrophysics Data System (ADS)

1. Introduction; 2. The physics of discreteness; 3. The road to calculus; 4. Temporal discretization; 5. Discrete time dynamics architecture; 6. Some models; 7. Classical cellular automata; 8. The action sum; 9. Worked examples; 10. Lee's approach to discrete time mechanics; 11. Elliptic billiards; 12. The construction of system functions; 13. The classical discrete time oscillator; 14. Type 2 temporal discretization; 15. Intermission; 16. Discrete time quantum mechanics; 17. The quantized discrete time oscillator; 18. Path integrals; 19. Quantum encoding; 20. Discrete time classical field equations; 21. The discrete time Schrodinger equation; 22. The discrete time Klein-Gordon equation; 23. The discrete time Dirac equation; 24. Discrete time Maxwell's equations; 25. The discrete time Skyrme model; 26. Discrete time quantum field theory; 27. Interacting discrete time scalar fields; 28. Space, time and gravitation; 29. Causality and observation; 30. Concluding remarks; Appendix A. Coherent states; Appendix B. The time-dependent oscillator; Appendix C. Quaternions; Appendix D. Quantum registers; References; Index.

Jaroszkiewicz, George

2014-04-01

416

QUADRENNIAL MCNP TIMING STUDY  

SciTech Connect

The Los Alamos National Laboratory Monte Carlo N-Particle radiation transport code, MCNP, is widely used around the world for many radiation protection and shielding applications. As a well-known standard it is also an excellent vehicle for assessing the relative performance of scientific computing platforms. Every three-to-four years a new version of MCNP is released internationally by the Radiation Safety Information Computational Center (RSICC) in Oak Ridge, Tennessee. For each of the past few releases, we have also done a timing study to assess the progress of scientific computing platforms and software. These quadrennial timing studies are valuable to the radiation protection and shielding community because (a) they are performed by a recognized scientific team, not a computer vendor, (b) they use an internationally recognized code for radiation protection and shielding calculations, (c) they are eminently reproducible since the code and the test problems are internationally distributed. Further, if one has a computer platform, operating system, or compiler not presented in our results, its performance is directly comparable to the ones we report because it can use the same code, data, and test problems as we used. Our results, using a single processor per platform, indicate that hardware advances during the past three years have improved performance by less than a factor of two and software improvements have had a marginal effect on performance. The most significant impacts on performance have resulted from developments in multiprocessing and multitasking. The other most significant advance in the last three years has been the accelerated improvements in personal computers. In the last timing study, the tested personal computer was approximately a factor of four slower that the fastest machine tested, a DEC Alphastation 500. In the present study, the fastest PC tested was less than a factor of two slower than the fastest platform, which is a Compaq (previously DEC) Alpha XP1000.

E. C. SELCOW; B. D. LANSRUD

2000-09-01

417

The Timing of Sonoluminescence  

NASA Astrophysics Data System (ADS)

We measured the timing of the sonoluminescence flash by scattering laser light from the bubble. We performed this measurement on 17.8 kHz, 13.28 kHz and 7920 Hz systems and found that the flash typically occurs 100 nanoseconds before the minimum radius, contrary to previous claims that the flash always occurs within a nanosecond of the minimum radius. These results are important because they imply that previous hot models of sonoluminescence are wrong. We propose a new model: that the flash results from the discharge of an excited cold condensate, formed during the adiabatic expansion of the bubble.

Brennan, Thomas; Fralick, Gustave

2012-02-01

418

Daylight Saving Time  

NSDL National Science Digital Library

At the age of 78, in a moment of whimsy, Benjamin Franklin wrote An Economical Project, a discourse on the thrift of natural versus artificial lighting. Over two centuries later, nations around the world use a variation of his concept to conserve energy and more fully enjoy the benefits of daylight. This website explains many aspects of Daylight Saving Time (DST), including when it begins and ends in the U.S and other countries, the rationale and original idea and its early adoption.

419

Daylight Savings Time  

NSDL National Science Digital Library

The California Energy Commission summaries the history of daylight savings and why we use it at this website. Users can discover where and how other areas of the world change the time to deal with the varying sunlight throughout the year. The website summarizes Benjamin Franklin's and William Willett's ideas for saving energy. Individuals can discover how daylight savings can save energy, save lives, prevent traffic accidents, and prevent crime. Visitors can find a chart of the dates of daylight savings from 1990 to 2010.

420

Space time and rotations  

E-print Network

The paper considers the problem of finding the metric of space time around a rotating, weakly gravitating body. Both external and internal metric tensors are consistently found, together with an appropriate source tensor. All tensors are calculated at the lowest meaningful approximation in a power series. The two physical parameters entering the equations (the mass and the angular momentum per unit mass) are assumed to be such that the mass effects are negligible with respect to the rotation effects. A non zero Riemann tensor is obtained. The order of magnitude of the effects at the laboratory scale is such as to allow for experimental verification of the theory.

A. Tartaglia

2002-01-04

421

Space-time qubits  

SciTech Connect

We construct a qubit algebra from field creation and annihilation operators acting on a global vacuum state. Particles to be used as qubits are created from the vacuum by a near-deterministic single-particle source. Our formulation makes the space-time dependence of the qubits explicit, preparing the way for quantum computation within a field framework. The method can be generalized to deal with interacting qubits whose wave packets are not perfectly matched to each other. We give an example of how to calculate the Heisenberg evolution of a simple two-qubit circuit, taking expectation values in the field vacuum state.

Pienaar, J. L.; Myers, C. R.; Ralph, T. C. [Centre for Quantum Computation and Communication Technology, School of Mathematics and Physics, University of Queensland, Brisbane 4072, Queensland (Australia)

2011-08-15

422

A Matter of Time  

NASA Technical Reports Server (NTRS)

16 February 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of the south polar residual cap where the effects of sublimation are apparent. Over extended periods of time, sublimation 'eats' away at the smoother appearing material (largely composed of frozen carbon dioxide), darkening the scarps and creating the irregularly shaped depressions that are present throughout much of the scene.

Location near: 87.1oS, 69.3oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

2006-01-01

423

"Signs of the Times"  

PubMed Central

Medical practice and research in colonial India historically had been an imperial preserve, dominated by the elite members of the Indian Medical Service. This was contested from the 1900s on by the emerging Indian nationalism. This essay studies debates about the establishment of a medical research institution and how actors imposed the political identities of nationalism on British colonial practices of medical science. At the same time, Indian nationalism was also drawing from other emerging ideas around health and social welfare. The Indian nationalists and doctors sought to build the identities of the new nation and its medicine around their own ideas of its geography, people, and welfare. PMID:20027771

Chakrabarti, Pratik

2009-01-01

424

Time Dilation Equation  

NSDL National Science Digital Library

This online article is from the Museum's Seminars on Science, a series of distance-learning courses designed to help educators meet the new national science standards. The article, which offers a simple demonstration of Einstein's Time Dilation Equation, is part of the Frontiers in Physical Science seminar. It uses the example of a light beam bouncing between two mirrors in a rocket to illustrate the theory, and includes a step-by-step look at the math involved in calculating the quantitative solution.

425

Timing is Everything  

NSDL National Science Digital Library

Kids today are growing up with televisions, movies, videos, and DVDs, so it's logical to assume that this type of media could be motivating and used to great effect in the classroom. But at what point should film and other visual media be used? Are there times in the inquiry process when showing a film or incorporating other visual media is more effective? One teacher tackles these questions by assessing video use among her upper-elementary students in a small rural Northeastern Missouri school district.

Drury, Debra

2006-07-01

426

Exploring Time Series Plots  

NSDL National Science Digital Library

Students will explore time series plots and raw data to understand the role of sea surface temperature increases on arctic ice melt. This is part three of a four-part activity on polar science. The activity builds on the knowledge gained in Using Data and Images to Understand Albedo (part 2). Extension activities examining air and sea surface temperature in relation to changing Earth albedo are included. Information is provided on data access using the NOAA Earth System Research Laboratory Web site. This activity is one of several learning activities connected with the 2007 GLOBE Earth system poster.

427

New York Times: Business  

NSDL National Science Digital Library

The New York Times has redesigned the business section on its web site; it features the latest business news and updates from the stock market. A Business Briefcase section has now been added; this section features the latest business books, business travel, the mutual funds quarterly report, company capsules from Hoover's Inc., and the latest loan and deposit rates from BanxQuote. The Your Money section caters to the personal investor; it provides investors with articles on investing, tools for managing their portfolio and a forum for discussing the stock market. Users in the United States may access the site free of charge after registering.

428

Native American Times  

NSDL National Science Digital Library

The Native American Times makes good on its promise to deliver "today's independent Indian news." The site has a clean design that includes ten sections covering topics like business, culture, education, sports, and powwows. The News area offers a nice digest of what's going on in several areas of interest to Native Americans, with topical headlines that include "Cherokee Art Market Announces Winners" and "Yakama Maintain Wild Horse Race Tradition." The site also includes a great jobs area for folks who might be looking for Native American-focused work in public policy, community development, technology, and other fields.

429

Climate Time Machine  

NSDL National Science Digital Library

Go backward and forward in time with this interactive visualization that illustrates how the Earth's climate has changed in recent history. Topics covered are Sea Ice: ice cap extent 1979 - 2007, Sea Level: effect on coastal regions for each meter of sea level rise, Carbon Emissions: amount of annual fossil fuel emissions produced by the top 12 nations or regions from 1980-2004, and Average Global Temperature: a color-coded map showing the progression of changing global surface temperatures from 1885 to 2007.

430

Biotechnology Through Time  

NSDL National Science Digital Library

In this activity, learners investigate the history and development of agricultural biotechnology. This experience begins with a Bio-Fest, in which learners use their senses to make observations about root beer, assorted cheeses, bread and yogurt. Learners are encouraged to think about the process of making food and how it has changed over time. This leads to a discussion about biotechnology. Learners complete the lesson by researching and completing a timeline. This activity is featured on pp.7-8 (part of a lesson that begins on p.6) of the "Yesterday, Today and Tomorrow: Agricultural Biology" unit of study for grades 6-8.

Indianapolis, The C.

2007-01-01

431

Time-Delay Interferometry  

NASA Astrophysics Data System (ADS)

Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers), the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI). This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA) mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

Tinto, Massimo; Dhurandhar, Sanjeev V.

2014-08-01

432

Timing of cyber conflict.  

PubMed

Nations are accumulating cyber resources in the form of stockpiles of zero-day exploits as well as other novel methods of engaging in future cyber conflict against selected targets. This paper analyzes the optimal timing for the use of such cyber resources. A simple mathematical model is offered to clarify how the timing of such a choice can depend on the stakes involved in the present situation, as well as the characteristics of the resource for exploitation. The model deals with the question of when the resource should be used given that its use today may well prevent it from being available for use later. The analysis provides concepts, theory, applications, and distinctions to promote the understanding strategy aspects of cyber conflict. Case studies include the Stuxnet attack on Iran's nuclear program, the Iranian cyber attack on the energy firm Saudi Aramco, the persistent cyber espionage carried out by the Chinese military, and an analogous case of economic coercion by China in a dispute with Japan. The effects of the rapidly expanding market for zero-day exploits are also analyzed. The goal of the paper is to promote the understanding of this domain of cyber conflict to mitigate the harm it can do, and harness the capabilities it can provide. PMID:24474752

Axelrod, Robert; Iliev, Rumen

2014-01-28

433

Causality between time series  

E-print Network

Given two time series, can one tell, in a rigorous and quantitative way, the cause and effect between them? Based on a recently rigorized physical notion namely information flow, we arrive at a concise formula and give this challenging question, which is of wide concern in different disciplines, a positive answer. Here causality is measured by the time rate of change of information flowing from one series, say, X2, to another, X1. The measure is asymmetric between the two parties and, particularly, if the process underlying X1 does not depend on X2, then the resulting causality from X2 to X1 vanishes. The formula is tight in form, involving only the commonly used statistics, sample covariances. It has been validated with touchstone series purportedly generated with one-way causality. It has also been applied to the investigation of real world problems; an example presented here is the cause-effect relation between two climate modes, El Ni\\~no and Indian Ocean Dipole, which have been linked to the hazards in f...

Liang, X San

2014-01-01

434

Real Time Spectral Analysis  

NASA Astrophysics Data System (ADS)

For signal analysis, Fourier transform and linear prediction methods are the main approaches. In recent years, wavelet transform which gives the expression of time-frequency domain has been receiving attention. In the wavelet transform, scale and shift operations are used to analyze regional waves in signal. In this paper, we propose a new method for signal analysis. Instead of the wavelet, short sine waves and short cosine waves which have slightly different frequencies and phases established beforehand are used. These frequencies and phases play the same role as a wavelet to analyze a regional wave in signal. However, our proposed method is different from the wavelet transform because it does not use multi-resolution analysis. In conventional spectral analysis methods, all data are prepared beforehand and calculations are carried out using these data. In our proposed method, spectrum is updated whenever the new signal data comes in. We show that the amount of calculation takes a remarkable reduction and it realizes real time spectral analysis. Finally, we show the vocal sounds analysis using the proposed method.

Nakatsuji, Hideto; Omatu, Sigeru

435

Prime time sexual harrassment.  

PubMed

This study explores the explicit and implicit messages of sexual harassment that viewers receive when viewing prime-time television in the US. A content analysis of 48 hours of prime-time television reveals that sexual harassment on television is both highly visible and invisible. Sexual harassment is rendered visible simply by its prominence in these programs. Incidents involving quid-pro-quo harassment and environmental harassment occur with regularity on television. Furthermore, about 84% of the shows studied contained at least one incident of sexual harassment; yet these acts of sexual harassment remained largely invisible because none of the behaviors were labeled as sexual harassment. These incidents are presented in humorous ways, and victims are generally unharmed and very effective at ending the harassment. Although such programs may actually reflect the reality of many women's lives in terms of prevalence of sexual harassment, they perpetuate several myths about sexual harassment, such as that sexual harassment is not serious and that victims should be able to handle the situations themselves. PMID:12294811

Grauerholz, E; King, A

1997-04-01

436

ACCURATE REAL-TIME WINDOWED TIME WARPING Robert Macrae  

E-print Network

ACCURATE REAL-TIME WINDOWED TIME WARPING Robert Macrae Centre for Digital Music robert.macrae@elec.qmul.ac.uk Simon Dixon Centre for Digital Music simon.dixon@elec.qmul.ac.uk ABSTRACT Dynamic Time Warping (DTW in advance and has quadratic time and space requirements. As such DTW is unsuitable for real-time

Dixon, Simon

437

Time Domain Time Domain Description of Linear Systems  

E-print Network

Time Domain Time Domain Description of Linear Systems #12;Time Domain Definition A behavior B: the future of every trajectory is completely determined by its past. #12;Time Domain Theorem Let P() R if it is of the form w(t) = N k=1 rk (t)ek t with rk () C[] an arbitrary polynomial of degree less than nk . #12;Time

Vellekoop, Michel

438

Keep Your Eyes on the Prize: Critical Stance in the Middle School Classroom  

ERIC Educational Resources Information Center

This study focuses on ways that sixth graders reacted to the question of book awards and awards in general, positioning themselves as reflective inquirers as they engaged in the regular sixth-grade beginning-of-the-year curriculum--reading books that have been nominated for the state book award. The authors focus on four dispositions of critical…

Lewison, Mitzi; Heffernan, Lee

2009-01-01

439

The Knowledgeable Parenting Style: Stance Takings and Subject Positions in Media Encounters  

ERIC Educational Resources Information Center

In today's media-saturated societies it can be assumed that encounters with therapists and other experts may have implications for adult learning. Taking the point of departure in the idea of public pedagogy, and by using a close-up analysis of interview talk, the pedagogical agency the media may have on parenting is investigated. Drawing…

Aarsand, Liselott

2014-01-01

440

The Value of a Learner’s Stance: Lessons Learned from Pregnant and Parenting Women  

Microsoft Academic Search

Objectives The voices, perspectives, and experiences of pregnant and parenting women are vital sources of information often overlooked\\u000a or not understood by professionals. The goals of this qualitative study were to understand access to maternal and child health\\u000a services from the perspectives of diverse consumers, and provide rich descriptions to inform strategies to enhance the quality\\u000a of this access. It

Larry Humbert; Theresa L. Roberts

2009-01-01

441

Analysis of Workplace Surveillance in a Quest for an Ethical Stance  

Microsoft Academic Search

This article examines the incidence of surveillance in higher learning academic institutions in Pakistan. It gives an overview of surveillance in a workplace and outlines how the latest technology has made the task more convenient for employers. It further delves into the privacy issues that arise as a consequence of surveillance. A review of related ethical theories has been undertaken

Saima Ahmed

442

Defining an ‘anti’ stance: key pedagogical questions about engaging anti?racism in college classrooms  

Microsoft Academic Search

This paper draws from social science literature on Whiteness and anti?racism as well as personal classroom experience to examine the obstacles educators face in teaching anti?racism to White college students. Emphasis is placed on popular perceptions and common definitions of the word ‘racism’ as it is used in mainstream American society. The authors explore the problems that arise when trying

Amanda Moras

2006-01-01

443

Ideologies of Violence: A Corpus and Discourse Analytic Approach to Stance in Threatening Communications  

ERIC Educational Resources Information Center

This authentic threat asserts impending fatal injury. Because of the dangerous nature of threats, investigators must immediately ask: Is the intent real? Is the threatener likely to act? With real lives at risk, using the linguistic information available to answer these questions quickly and accurately is of great importance. Yet, because most…

Gales, Tammy Angela

2010-01-01

444

Of risks and regulations: how leading U.S. nanoscientists form policy stances about nanotechnology  

Microsoft Academic Search

Even though there is a high degree of scientific uncertainty about the risks of nanotechnology, many scholars have argued\\u000a that policy-making cannot be placed on hold until risk assessments are complete (Faunce, Med J Aust 186(4):189–191, 2007; Kuzma, J Nanopart Res 9(1):165–182, 2007; O’Brien and Cummins, Hum Ecol Risk Assess 14(3):568–592, 2008; Powell et al., Environ Manag 42(3):426–443, 2008). In the

Elizabeth A. Corley; Dietram A. Scheufele; Qian Hu

2009-01-01

445

Taking a Stance through Visual Texts: Novice Teachers as Educational Agents  

ERIC Educational Resources Information Center

Drawing on qualitative methodologies that integrate verbal and non-verbal texts, this study investigated novice teachers' attributions of their experiences of internship, as conveyed through a visual text. Novices were invited to design a visual text that represented their experience during internship, as part of a national call entitled…

Orland-Barak, Lily; Maskit, Ditza

2014-01-01

446

Stance-shifting in language used by sex offenders: Five case studies  

Microsoft Academic Search

Attempts to classify sex offenders for the purpose of investigating sexual assaults or formulating treatment strategies often use evidence left at crime scenes, victims’ statements, and case studies to organize sex offenders’ personality characteristics into categories. Typologies of offenders may vary in the degree to which they are empirical or incorporate offender language. In the treatment of sex offenders, some

Vivian B. Lord; Boyd Davis; Peyton Mason

2008-01-01

447

John Tooby & Leda Cosmides6 SubStance # 94/95, 2001  

E-print Network

many of the functional design features of species, including humans, have the forms that they do: The Anomaly of the Arts in the Evolutionary Landscape Organic evolution has two independent components, which, according to the logical framework derived from modern Darwinism, all features of a species' cognitive

Cosmides, Leda

448

Defining an "Anti" Stance: Key Pedagogical Questions about Engaging Anti-Racism in College Classrooms  

ERIC Educational Resources Information Center

This paper draws from social science literature on Whiteness and anti-racism as well as personal classroom experience to examine the obstacles educators face in teaching anti-racism to White college students. Emphasis is placed on popular perceptions and common definitions of the word "racism" as it is used in mainstream American society. The…

Rebollo-Gil, Guillermo; Moras, Amanda

2006-01-01

449

Emotions in the Cross-Fire: Structuralist vs. Post-Structuralist Stances in Bilingualism Research  

ERIC Educational Resources Information Center

What Aneta Pavlenko discusses in this fascinating article is so widely researched, so cogently conceptualized and so richly reflected upon, that one feels like a spoilsport to bring up a debate which the author herself claims to have avoided, namely the "universalist/relativist debate about basic emotions". If I do so in this Commentary, it is not…

Kramsch, Claire

2008-01-01

450

Dimensions of the Feminist Research Methodology Debate: Impetus, Definitions, Dilemmas & Stances.  

ERIC Educational Resources Information Center

For various well-documented reasons, the feminist social movement has been critical of academia as a worksetting and of the social sciences as a set of disciplines. For these reasons, feminists claim that the assumptions underlying several research designs and procedures are sexist. They have developed a feminist methodology to examine these…

Reinharz, Shulamit

451

Lexical Bundle Analysis in Mathematics Classroom Discourse: The Significance of Stance  

ERIC Educational Resources Information Center

In this article, we introduce the lexical bundle, defined by corpus linguists as a group of three or more words that frequently recur together, in a single group, in a particular register (Biber, Johansson, Leech, Conrad, & Finegan, 2006; Cortes, "English for Specific Purposes" 23:397-423, 2004). Attention to lexical bundles helps to explore…

Herbel-Eisenmann, Beth; Wagner, David; Cortes, Viviana

2010-01-01

452

J's Epistemological Stance and Strategies To appear in Intentional Conceptual Change, G. Sinatra &  

E-print Network

, we are motivated by prior work on "intuitive physics," students' unschooled ideas about the physical their experiences in everyday life and in school. The study of students' epistemological ideas has become has validated the principle that students have ideas about knowledge that affect their learning

Elby, Andy

453

"Does Broca's Area Exist?:" Christofredo Jakob's 1906 Response to Pierre Marie's Holistic Stance  

ERIC Educational Resources Information Center

In 1906, Pierre Marie triggered a heated controversy and an exchange of articles with Jules Dejerine over the localization of language functions in the human brain. The debate spread internationally. One of the timeliest responses, that appeared in print 1 month after Marie's paper, came from Christofredo Jakob, a Bavarian-born neuropathologist…

Tsapkini, Kyrana; Vivas, Ana B.; Triarhou, Lazaros C.

2008-01-01

454

Neural Correlates of Detecting Pretense: Automatic Engagement of the Intentional Stance under Covert Conditions  

Microsoft Academic Search

Typically developing children begin to produce and understand pretend play between 18 and 24 months of age, and early pretense has been argued to be a candidate core capacity central to the deployment of representations of other peoples' mental statestheory of mind. In a functional magnetic resonance imaging study, 16 healthy adult volunteers were imaged while watching short (5 sec)

Tim P. German; Jeffrey L. Niehaus; Meghan P. Roarty; Barry Giesbrecht; Michael B. Miller

2004-01-01

455

Experimental verification of a computational technique for determining ground reactions in human bipedal stance.  

PubMed

We have developed a three-dimensional (3D) biomechanical model of human standing that enables us to study the mechanisms of posture and balance simultaneously in various directions in space. Since the two feet are on the ground, the system defines a kinematically closed-chain which has redundancy problems that cannot be resolved using the laws of mechanics alone. We have developed a computational (optimization) technique that avoids the problems with the closed-chain formulation thus giving users of such models the ability to make predictions of joint moments, and potentially, muscle activations using more sophisticated musculoskeletal models. This paper describes the experimental verification of the computational technique that is used to estimate the ground reaction vector acting on an unconstrained foot while the other foot is attached to the ground, thus allowing human bipedal standing to be analyzed as an open-chain system. The computational approach was verified in terms of its ability to predict lower extremity joint moments derived from inverse dynamic simulations performed on data acquired from four able-bodied volunteers standing in various postures on force platforms. Sensitivity analyses performed with model simulations indicated which ground reaction force (GRF) and center of pressure (COP) components were most critical for providing better estimates of the joint moments. Overall, the joint moments predicted by the optimization approach are strongly correlated with the joint moments computed using the experimentally measured GRF and COP (0.78 < or = r(2) < or = 0.99,median,0.96) with a best-fit that was not statistically different from a straight line with unity slope (experimental=computational results) for postures of the four subjects examined. These results indicate that this model-based technique can be relied upon to predict reasonable and consistent estimates of the joint moments using the predicted GRF and COP for most standing postures. PMID:16797023

Audu, Musa L; Kirsch, Robert F; Triolo, Ronald J

2007-01-01

456

Taking Things at Face Value: How Stance Informs Politeness of Virtual Agents  

E-print Network

practical training sessions in the form of interaction with actors. Moreover, only a few police officers is to implement this model in a serious game for police training. 1 Introduction The automatic generation within the field of law enforcement. To assist in the training curriculum of the Dutch police, we

Theune, Mariët

457

Developing an Anti-Racist Stance: How White Youth Understand Structural Racism  

Microsoft Academic Search

Racism continues to be a formidable and pressing problem. While racism can take many forms, and overt, legally sanctioned acts of racism have declined, structural racism continues to persist. Structural racism encompasses both institutional racism and the broader effects of social racism. White allies--White individuals committed to using their unearned power and privilege to work to dismantle racism--can play a

Catharine R. Thomann

2011-01-01

458

Other-repetition as display of hearing, understanding and emotional stance  

Microsoft Academic Search

In this article, other-repetition after informing statements is investigated in a corpus of institutional encounters between native Norwegian clerks and non-native clients. Such repetition is used to display receipt of information. A plain repeat with falling intonation is described as a display of hearing, whereas a repeat plus a final response particle, ‘ja’ (yes), constitutes a claim of understanding. Repeats

Jan Svennevig

2004-01-01

459

Teachers' Emerging Stances and Repertoires towards Reconciliation: Potential and Challenges in Greek-Cypriot Education  

ERIC Educational Resources Information Center

In this paper we examine Greek-Cypriot teachers' positions towards the--largely unfamiliar--concept of reconciliation within the Greek-Cypriot community. Looking at a set of 40 interviews conducted in spring 2009, this study is set against the broader historical context of the continuing Cyprus Problem and the development of ethnic rivalry between…

Zembylas, Michalinos; Charalambous, Panayiota; Charalambous, Constadina

2011-01-01

460

Genetic counseling and the disabled: feminism examines the stance of those who stand at the gate.  

PubMed

This essay examines the possible systematic bias against the disabled in the structure and practice of genetic counseling. Finding that the profession's "nondirective" imperative remains problematic, the authors recommend that methodology developed by feminist standpoint epistemology be used to incorporate the perspective of disabled individuals in genetic counselors' education and practice, thereby reforming society's view of the disabled and preventing possible negative effects of genetic counseling on the self-concept and material circumstance of disabled individuals. PMID:14682342

Patterson, Annette; Satz, Martha

2002-01-01

461

November 16, 2010 Rep.-Elect West's Drilling Stance --and Refusal to Back Down --  

E-print Network

the optimal mix of U.S. fuel sources to a "diversified investment portfolio" on his campaign website. "Now on immigration grabbed headlines. Pressed on the flap by CNN, West, one of two African-American Republicans drilling is actually not as harmful because people see it as kind of an economic growth issue, a jobs issue

Belogay, Eugene A.

462

Estimation of Quasi-Stiffness of the Human Knee in the Stance Phase of Walking  

E-print Network

the original author and source are credited. Funding: 1. US Defense Medical Research Development Program-stiffness for preferred walking speed with average error of 9% with only one outlier. These results provide a useful, contract #W81XWH-11-2-0054, 2. US Army Natick Soldier Research Development and Engineering Center, contract

Dollar, Aaron M.

463

Estimation of Quasi-Stiffness of the Human Hip in the Stance Phase of Walking  

E-print Network

and source are credited. Funding: This work was supported by the US Defense Medical Research Development-stiffness for the preferred gait speed using only body weight and height with an average error of 27% for the extension stage

Dollar, Aaron M.

464

Argumentative stance and political faith healing: “The dream will come true”  

Microsoft Academic Search

This essay analyzes President Ronald Reagan's speech “On Our Economic Recovery” as a means of exploring the argumentative resources of political faith healing. By exploiting the illocutionary ambiguity of “shall” and “must,” the faith healer as rhetor permits a state of healing to be seen as either prediction or command. By strategic identification and division, faith healers—both mystical and political—can

Richard E. Crable; Steven L. Vibbert

1983-01-01

465

Effect of equinus foot placement and intrinsic muscle response on knee extension during stance  

E-print Network

, a common movement abnormality among individuals with stroke and cerebral palsy, is often associated or cerebral palsy [1]. The exaggerated ankle plantarflexion at initial foot contact typical of equinus gait has been attributed to stiff or spastic ankle plantarflexors, premature activity of the ankle

466

Technocratic and design stances toward communication expertise: how GDSS facilitators understand their work  

Microsoft Academic Search

This study investigates the shared, and often unstated, premises that frame the expert communication servicing of meeting facilitators who implement group decision support systems (GDSS). Nine premises about facilitating communication were reconstructed from the way practitioners use the concept \\

Mark Aakhus

2001-01-01

467

Briefing paper N3-2001 The fiscal stance and economic coordination in Europe  

E-print Network

is the extent of the problem? First, the fiscal deficit of the euro area is low and although forecasted preceding the launching of the euro and that this procyclical episode has left the three "big economies

Paris-Sud XI, Université de

468

Human stance on a sinusoidally translating platform: balance control by feedforward and feedback mechanisms  

Microsoft Academic Search

With subjects standing on a treadmill moving sinusoidally backward and forward, recordings of electromyographic (EMG) leg and trunk muscle activity, head and joint movements and platform torque were made with the subjects' eyes open or closed. The sinusoidal frequency was changed, stepwise and randomly, between 0.5, 0.3 and 0.25 Hz. The amplitude of the deflection was constant at ±12 cm.

V. Dietz; M. Trippel; I. K. Ibrahim; W. Berger

1993-01-01

469

Preservice Teachers Listen to Families of Students with Disabilities and Learn a Disability Studies Stance  

ERIC Educational Resources Information Center

"These families must be so sad. I just wonder what they do and if they have any type of normal life." "I am not sure how I will work with parents. I think they probably look to the school for a lot of help." These quotes were taken from preservice teachers' papers early in their teacher education program, in which they were asked to describe what…

Sauer, Janet S.; Kasa, Christi

2012-01-01

470

A Critical Stance in Language Education: A Reply to Alan Waters  

ERIC Educational Resources Information Center

In his recent Forum article on ideology in applied linguistics, Alan Waters (2009) takes up arms against what he perceives as a damaging critical tendency. Ideas about language teaching, he claims, are promoted (e.g. learner centredness) or proscribed (e.g. artificial texts) "on the basis of ideological belief rather than pedagogical value". By…

Simpson, James

2009-01-01

471

Teachers’ Stances and Practical Arguments Regarding a Science?Indigenous Knowledge Curriculum: Part 1  

Microsoft Academic Search

The new South African curriculum known as Curriculum 2005 (to depict the year of its full implementation) requires that teachers integrate school science with Indigenous Knowledge Systems (IKS). Curriculum 2005 has generated heated debates at various levels since its inception in 1997. This study focuses on the effectiveness or otherwise of a Practical Argumentation Course (PAC) as an instructional tool

M. B. Ogunniyi

2007-01-01

472

Paper presented at AERA 2007, Chicago, IL Modeling Manifold Epistemological Stances with  

E-print Network

implement these conjectured behaviors; (c) emergence--investigate intelligence as a collection of emergent, have been termed complex and are collectively studied in a relatively young interdisciplinary field in classrooms (Abrahamson, Blikstein & Wilensky, 2007). We, too, propose to use ABM to simulate human reasoning

Wilensky, Uri

473

Evaluating the Current Stance of Monetary Policy Using a Taylor Rule. January 30, 2012.  

National Technical Information Service (NTIS)

Oversight of the Federal Reserve's (Fed's) monetary policy decisions rests with Congress. But oversight is encumbered by the absence of a straightforward relationship between interest rates and economic performance. Further, the Fed's policy decisions are...

M. Labonte

2012-01-01

474

Shifting Journalistic Paradigms: Editorial Stance and Political Transition in Hong Kong.  

ERIC Educational Resources Information Center

This paper suggests that the upcoming transfer of Hong Kong from Great Britain to the People's Republic of China (PRC) in 1997, offers a unique opportunity to observe how changing configurations in the political environment influence mass media. The article investigates how the Hong Kong press, which spans the entire left-center-right ideological…

Chan, Joseph Man; Lee, Chin-Chuan

475

January 1992 Report No. STAN-CS-92-1412 Toward Agent Programs With Circuit Semantics  

E-print Network

that function effectively for long periods in the physical world without human intervention. From the governors is a necessary component of effective action. Perhaps it is relatively easier for control theorists than fundamental control-theory ideas into the core of computer science. That is precisely what I set out to do

Pratt, Vaughan

476

Exploring Literacy Coaches' Relationships with Teachers: Balancing Responsive and Directive Coaching Stances  

ERIC Educational Resources Information Center

Literacy coaching has become an increasingly popular form of literacy professional development in the United States based on the common assumption that strong relationships between coaches and teachers will drive instructional improvement and gains in student achievement. However, there is little empirical research describing how literacy coaches…

Ippolito, Jacy C.

2009-01-01

477

Designing Worked Examples in Statics to Promote an Expert Stance: Working THRU vs. Working OUT  

ERIC Educational Resources Information Center

The purpose of this study was to examine the performance patterns of freshman engineering students as they completed a tutorial on freebody problems that employed a computer-based pen (CBP) to provide feedback and direct learning. A secondary analysis was conducted on detailed performance data for 16 participants from a freshman Engineering course…

Calfee, Robert; Stahovich, Thomas

2011-01-01

478

Mastering Academic Language: Organization and Stance in the Persuasive Writing of High School Students  

ERIC Educational Resources Information Center

Beyond mechanics and spelling conventions, academic writing requires progressive mastery of advanced language forms and functions. Pedagogically useful tools to assess such language features in adolescents' writing, however, are not yet available. This study examines language predictors of writing quality in 51 persuasive essays produced by high…

Uccelli, Paola; Dobbs, Christina L.; Scott, Jessica

2013-01-01

479

Redefining Online Discussions: Using Participant Stances to Promote Collaboration and Cognitive Engagement  

ERIC Educational Resources Information Center

Advances in technology are having a profound impact on distance education as online learning is becoming a preferred educational option. Within these online learning experiences, the asynchronous online discussion has evolved into one of the most commonly used communication tools. However, a lack of cognitive processing and interaction in the…

Putman, S. Michael; Ford, Karen; Tancock, Susan

2012-01-01

480

Culturally Sustaining Pedagogy: A Needed Change in Stance, Terminology, and Practice  

ERIC Educational Resources Information Center

Seventeen years ago Gloria Ladson-Billings (1995) published the landmark article "Toward a Theory of Culturally Relevant Pedagogy," giving a coherent theoretical statement for resource pedagogies that had been building throughout the 1970s and 1980s. I, like countless teachers and university-based researchers, have been inspired by what it means…

Paris, Django

2012-01-01

481

Pedunculopontine ucleus Area Oscillations during Stance, Stepping and Freezing in Parkinson's Disease  

E-print Network

freezing of gait (FOG). In the days following the surgery, we recorded behavioural data together had FOG during step-in-place trials, while ON levodopa, stepping was effective (mean duration of FOG such as freezing of gait (FOG) respond poorly to dopaminergic or surgical treatment. FOG is defined as a sudden

Paris-Sud XI, Université de

482

Real time automated inspection  

DOEpatents

A method and apparatus are described relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections. 43 figs.

Fant, K.M.; Fundakowski, R.A.; Levitt, T.S.; Overland, J.E.; Suresh, B.R.; Ulrich, F.W.

1985-05-21

483

Real time automated inspection  

DOEpatents

A method and apparatus relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges are segmented out by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections.

Fant, Karl M. (Minneapolis, MN); Fundakowski, Richard A. (Saint Paul, MN); Levitt, Tod S. (Minneapolis, MN); Overland, John E. (Plymouth, MN); Suresh, Bindinganavle R. (New Brighton, MN); Ulrich, Franz W. (Minneapolis, MN)

1985-01-01

484

Financial Times: Podcasts  

NSDL National Science Digital Library

The Financial Times is well-respected for their forays into business journalism and their reporting on various related matters. Recently, they have entered the world of podcasting with great vigor, and this site contains a trove of podcasts and audio files. Visitors can subscribe to their podcasts via iTunes, but they may first wish to look through the drop-down menu on the homepage. Here, visitors can look over (and listen to) recent programs on digital business, long-term investing, global philanthropy, and the World Economic Forum. Further down on the site, visitors can look through the archives of the FT Money Show. The archives stretch back to April 2007, and one nice feature here is the brief synopsis that is available for the most recent show.

485

BBC: In Our Time  

NSDL National Science Digital Library

Many have asked the question: "How do we understand the world around us?" Truly, it is a question that has animated discussion from Beijing to Bogota over the millennia, and it's one that motivates Melvyn Bragg, host of the BBC program "In Our Time". Drawing on guests from around the world, Bragg takes on science, culture, religion, philosophy, and history. Visitors can click on the "Explore Archive" area to travel through past programs, organized by theme. The "Science Archive" section alone is a real triumph, and with programs like "Neuroscience: Does the brain rule the mind?" and "The Multiverse", a group of friends could start their own mini-salon of ideas around the computer. Moving on, visitors can also sign up to receive Bragg's online newsletter and subscribe to the program's podcast. Finally, visitors can also throw their own three cents into the ring by offering their own commentaries via the "Have Your Say" comment form.

486

A Journey Through Time  

NSDL National Science Digital Library

Noted photographer Frans Lanting opens the website dedicated to his most recent ambitious project with these words: "Seven years ago I stood at the tide line of an estuary and began a personal journey through time.ïÿý Auspicious words indeed, and this lovely exploration of what he found on this journey takes visitors on a "lyrical interpretation of life on Earth from its earliest beginnings to its present diversity.ïÿý As visitors click on the words "Start Journey" they will be taken through eighty six photographs which document the various physical landforms and processes from the Hawaiian Islands to the heights of the Himalayas. After clicking on each photo, visitors will be presented with an interactive timeline that locates the photo within a timeline of geologic history. Interested parties can also peruse the "More about LIFE" section to learn more about the equipment Lanting uses in his work, and how the project came to life.

Lanting, Frans

487

Jazz Old Time Online  

NSDL National Science Digital Library

For fans of jazz, the Jazz Old Time site will be a fun way to listen to few well-known chestnuts from the early days of this musical idiom. Of course, those who don't know much about jazz will appreciate listening to a few new artists as well. The site features over 18,000 songs in the public domain, and visitors can browse through the selections by artists or take a look at a few sample playlists. As one might suspect, artists like King Oliver, Meade Lux Lewis, and Louis Armstrong are featured prominently, though early recordings from later artists, such as Stan Getz, are also available. The site might also be recommended to students in a music appreciation course.

488

China Digital Times  

NSDL National Science Digital Library

Created and maintained by the Berkeley China Internet Project, the China Digital Times (CDT) is a "collaborative news website covering China's social and political transition and its emerging role in the world." With their outstanding team of editors and media specialists, the CDT should be considered one of the most compelling sites covering important news and developments across China. Much like a traditional newspaper website, visitors can scroll through news highlights culled from various international media sources, add comments to various news items, and also search the entire site for specific materials. Those users with specific thematic interests will want to move right away to the "Sections" area, which breaks down news items into areas that include politics, society, Taiwan, economy, and culture. Even more fine tuned features can be found in the "News Focus" area, which includes sections that address human rights, the information revolution, and the environment.

489

Do you have the time?  

NSDL National Science Digital Library

Practice telling time with these awesome activities. Move the hands on the clock to play What time is it? Play a matching game with Analog vs. Digital clocks. Race against time in Stop the Clock! Help the dragon Set the Clock. You know what time it is now, but What time will it be? Grab a partner to play Willy the Watchdog . ...

Burkhart, Ms.

2007-11-03

490

QUEER TIME & SPACE IN CONTEMPORARY  

E-print Network

1 QUEER TIME & SPACE IN CONTEMPORARY EXPERIMENTAL WRITING SOPHIE ROBINSON SUBMITTED: ________________________ #12; 3 ABSTRACT QUEER TIME AND SPACE IN CONTEMPORARY EXPERIMENTAL WRITING The aim Bergvall and kari edwards. Specifically, I will be addressing representations of time and space

Sheldon, Nathan D.

491

Galaxies Across Cosmic Time  

NASA Astrophysics Data System (ADS)

As part of the Astro2010 Decadal Survey, the Galaxies across Cosmic Time (GCT) Science Frontier Panel was asked to identify the main scientific themes that between now and 2020 will drive research on the formation, evolution, and global properties of galaxies and galaxy clusters, as well as on supermassive black holes and active galactic nuclei. In its report, released in late August 2010, the panel articulated four central questions: (1) How do cosmic structures form and evolve? (2) How do baryons cycle in and out of galaxies, and what do they do while they are there? (3) How do black holes grow, radiate, and influence their surroundings? (4) What were the first objects to light up the universe, and when did they do it? The last of the four overlaps with what the panel identified as a prime area of unusual discovery potential: the Epoch of Reionization. This contribution reviews the panel's findings about the space-based observational programs deemed important for making progress in addressing these questions, as well the valuable role to be played by "critical work in... intellectual infrastructure, such as laboratory astrophysics." Separately, it provides the author's personal perspective on the most important contributions that can be made by laboratory work to GCT science via NASA missions over the next decade.

Baker, A. J.

2011-05-01

492

Time to taste  

PubMed Central

Circadian clocks keep time in the digestive, circulatory, reproductive, excretory and nervous systems even in absence of external cues. Central oscillators in the brain control locomotor activity of organisms ranging from fruit flies to man, but the functions of the clocks in peripheral nervous system are not well understood. The presence of autonomous peripheral oscillators in the major taste organ of drosophila, the proboscis, prompted us to test whether gustatory responses are under control of the circadian clock. We find that synchronous rhythms in physiological and behavioral responses to attractive and aversive tastants are driven by oscillators in gustatory receptor neurons (GRNs); primary sensory neurons that carry taste information from the proboscis to the brain. During the middle of the night, high levels of G protein-coupled receptor kinase 2 (GPRK2) in the GRNs suppresses tastant-evoked responses. Flies with disrupted gustatory clocks are hyperphagic and hyperactive, recapitulating behaviors typically seen under the stress of starvation. Temporal plasticity in innate behaviors should offer adaptive advantages to flies. In this Extra View article we discuss how oscillators inside GRNs regulate responsiveness to tastants and influence feeding, metabolism and general activity. PMID:20798595

Chatterjee, Abhishek

2010-01-01

493

[Time to be young].  

PubMed

The project entitled "Tempo de ser jovem" (time to be young) is implemented in Campanha, in the city of Porto, Portugal, to prevent dropping out from schools, drug abuse, and adolescent pregnancy in the Elementary School of Cerco, Porto, where many pupils have problems with fitting in owing to socioeconomic disadvantages and underprivileged status. The project was developed by the professionals of the local health center and by some teachers. Youth groups were formed to perform activities in health, the environment, social communication, and sports. The prevention of rising adolescent pregnancy was a goal because 25% of all births occur to girls aged 19 and under. Family planning is also vital because of the frequency of repeated pregnancies. Psychologists render counseling assistance to young people and local employment centers also offer social and vocational assistance in gardening, cleaning and domestic work in residential quarters. In the family planning courses groups of 15-20 persons are included and practical training is carried out dealing with nutrition during pregnancy as well as for adolescents and nursing mothers. Visits to homes of parents are also made and individual consultation is also offered. Motivation is the mainstay of all activities dealing with psychosocial aspects of adolescent pregnancy and motherhood, health and disease, and social marketing. PMID:12179269

1997-01-01

494

Local Times Around the World  

NSDL National Science Digital Library

This guide attempts to list all of the world's countries with a description of the local time in a region. Areas are grouped in a hierarchy by continent (region), country, and location. With each selection, information is given on geographical location; current local time, the current observed time, and the dates during which Daylight Savings Time is observed. Geographical locations are listed in degrees, minutes and seconds format. Current local time details the weekday and date and time from Greenwich Mean Time (GMT) and Coordinated Universal Time (UTC).

495

Calculating the Maximum Execution Time of Real-Time Programs  

Microsoft Academic Search

In real-time systems, the timing behavior is an important property of each task. It has to be guaranteed that the execution of a task does not take longer than the specified amount of time. Thus, a knowledge about the maximum execution time of programs is of utmost importance.

Peter P. Puschner; Christian Koza

1989-01-01

496

UTC: Official World Time GPS: A Time Distribution Utility  

E-print Network

· UTC: Official World Time · GPS: A Time Distribution Utility · Time: An Historical and Future Perspective · From Laboratory to Practical Use · Broad Applications Across Society Agilent AN 1289 The Science Analysis of Harrison-like Chronometers Appendix C: Time and Frequency Transfer, Distribution

Bernstein, Daniel

497

More ScreenTime Equals Less ActivityTime  

E-print Network

to 13 spend nearly six hours watching TV, playing video games or on the computer. Two-thirds of youth video games or on the computer. /// More Screen Time Equals Less Activity Time #12;More ScreenTime Equals Less ActivityTime (NAPS)--Don't touch that dial! Every day, children ages 8

Baker, Chris I.

498

Toward accurate dynamic time warping in linear time and space  

Microsoft Academic Search

Dynamic Time Warping (DTW) has a quadratic time and space complexity that limits its use to small time series. In this paper we introduce FastDTW, an approximation of DTW that has a linear time and space complexity. FastDTW uses a multilevel approach that recursively projects a solution from a coarser resolution and refines the projected solution. We prove the linear

Stan Salvador; Philip Chan

2007-01-01

499

Time, Place, and Content 53 Time, Place, and Content  

E-print Network

Time, Place, and Content 53 Time, Place, and Content Jonathon D. Crystal University of Georgia The goal of this article is to integrate information about basic mechanisms of time perception with research on time-place learning and research on the discrimination of what, when, and where (WWW). Several

Cook, Robert

500

time (sec) time (sec) ).u.a(edutilpma  

E-print Network

4 2 0 0 2 4 0 2 time (sec) time (sec) taebgniw ).u.a(edutilpma 15 10 5 0 4 taebgniw ).uH(ycneuqerf 0 2 4 0 2 4 B time (sec) time (sec) wild Or83b+/+ wild C D E F G H mango (1X) mango (1X) mango (1X (0.1X) mango (0.1X) mango (0.1X) mango (1X) Or83b+/+ 0 2 time (sec) 40 2 time (sec) 4 0 2 4 time (sec

Wilson, Rachel