scholarly journals Dynamic helical cyclophanes with two quadruply-bridged planes arranged in an “obverse and/or reverse” relation

2016 ◽  
Vol 7 (5) ◽  
pp. 3240-3247 ◽  
Author(s):  
Ryo Katoono ◽  
Shunsuke Kawai ◽  
Takanori Suzuki
Keyword(s):  
Counterclockwise Direction

We describe the design of two types of cyclophanes that generate dynamic helicity through the twisting of two planes in a clockwise or counterclockwise direction to give (M)- or (P)-helicity.

The Movement of Dye Solution in Dwarf Mistletoe-infected Black Spruce Trees

1973 ◽  
Vol 3 (2) ◽  
pp. 312-315 ◽  
Author(s):  
F. H. Tainter ◽  
D. W. French
Keyword(s):  
Black Spruce ◽  
Upward Movement ◽  
Acid Fuchsin ◽  
Dwarf Mistletoe ◽  
Counterclockwise Direction

Upward movement of acid fuchsin dye solution in dwarf mistletoe-infected black spruce trees generally occurred in a helical pattern. In seven of ten trees the dye ascended in a counterclockwise direction around the axis of the tree. All trees showed wide variation in direction of ascent, in some cases the dye column reversed direction of ascent partially up the bole. In some instances the witches' brooms apparently attracted the dye.

The Rotating Tilted Lines Illusion

2017 ◽  
Author(s):  
Simone Gori
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Stimulus Pattern ◽  
Motion Processing ◽  
White Background ◽  
Radial Expansion ◽  
Circular Pattern ◽  
Counterclockwise Direction ◽  
The Right ◽  
Rotatory Motion

This chapter describes the Rotating-Tilted-Lines illusion , which is a new motion illusion that arises in a circular pattern composed by black, radial lines tilted to the right and presented on a white background. When one approaches the stimulus pattern, the radial lines appear to rotate in the counterclockwise direction, whereas when one recedes from it, they appear to rotate clockwise. It is the simplest pattern able to elicit illusory rotatory motion in presence of physical radial expansion. This surprising misperception of motion seems to be a result of the competition between two motion processing units in the primary visual cortex (V1, V5)

Characteristics of Accessory Carpal Bone Fractures in 50 Racing Greyhounds

1988 ◽  
Vol 01 (02) ◽  
pp. 104-107 ◽  
Author(s):  
D. L. Piermattei ◽  
Ph. E. Davis ◽  
Ch. R. Bellenger ◽  
K. A. Johnson
Keyword(s):  
Bone Fractures ◽  
Carpal Bone ◽  
Teaching Hospitals ◽  
State University ◽  
Anatomical Distribution ◽  
Colorado State University ◽  
Counterclockwise Direction ◽  
Carpal Bone Fractures ◽  
Fracture Types ◽  
The University

Fifty racing greyhounds with fracture of the accessory carpal bone presented to the Veterinary Teaching Hospitals at The University of Sydney (n = 35) and Colorado State University (n = 15) were reviewed for the purpose of identifying the frequency of the various fracture types, and to suggest possible factors which predispose to the injuries. All but three fractures occurred while the dogs were racing. All dogs raced on elliptical tracks in a counterclockwise direction, and this was implicated in the pathogenesis and anatomical distribution of these fractures.

Polarity in spontaneous unwinding after prior rotation of the flagellar beat plane in sea-urchin spermatozoa

1991 ◽  
Vol 98 (2) ◽  
pp. 183-189 ◽  
Author(s):  
K. Takahashi ◽  
C. Shingyoji ◽  
J. Katada ◽  
D. Eshel ◽  
I.R. Gibbons
Keyword(s):  
Angular Velocity ◽  
Sea Urchin ◽  
Initial Velocity ◽  
Central Pair ◽  
Counterclockwise Direction ◽  
Flagellar Beat ◽  
Elastic Distortion ◽  
The Difference ◽  
Sea Urchin Sperm

The flagellar beat plane of live and reactivated sea-urchin sperm held by their heads in the tip of a vibrating micropipette will rotate along with the plane of the imposed vibration for up to 10 revolutions in either a clockwise or a counterclockwise direction. Subsequent cessation of the imposed vibration is followed by spontaneous unwinding of the flagellar beat plane. Nearly complete unwinding occurs after prior counterclockwise winding. The unwinding of the beat plane after prior clockwise winding is incomplete, but the number of revolutions that remain unwound affects the response of the flagellar beat plane to a second set of imposed revolutions. The initial angular velocity of spontaneous unwinding is approximately proportional to the number of prior winding cycles, independent of their direction. The maximum initial velocity of unwinding was 27 rad s-1 and 20 rad s-1 for live and reactivated sperm, respectively. These data suggest that the force responsible for unwinding of the beat plane is derived from the elastic distortion of some component in the axonemal structure. The difference in completeness of spontaneous unwinding between the two directions of rotation is consistent with the previously suggested hypothesis that imposed rotation of the beat plane reflects the forced rotation of the central pair within the axoneme.

Perceived Key Movement in Four-Voice Harmony and Single Voices

1992 ◽  
Vol 9 (4) ◽  
pp. 427-438 ◽  
Author(s):  
William F. Thompson ◽  
Lola L. Cuddy
Keyword(s):  
Musical Training ◽  
Close Correspondence ◽  
Moderate Amount ◽  
Harmonic Progression ◽  
Counterclockwise Direction ◽  
Single Voice ◽  
Complete Set

Listeners with a moderate amount of musical training rated the distance between the first and final key of short chorale excerpts under one of four presentation conditions. The distance between keys, or modulation distance, was either zero, one, or two steps in either the clockwise or counterclockwise direction on the cycle of fifths. Presentation conditions were four-voice harmonic sequences excerpted from the complete set of Bach chorales, single voices of the latter sequences, four-voice harmonic sequences simplified to block chords, and single voices of the latter sequences. Consistent with earlier findings (Thompson & Cuddy, 1989), judgments for both four- voice harmonic presentations and single-voice presentations revealed a close correspondence between modulation distance and judged distance. Ratings for harmonic sequences within a given key distance, however, showed influences of direction of modulation and of harmonic progression that were not reflected in ratings for single voices. The findings suggest that harmony and melody follow somewhat different principles in the process of identifying key change.

scholarly journals Fast degradation of the circular flare ribbon on 2014 August 24

2020 ◽  
Vol 636 ◽  
pp. L11
Author(s):  
Q. M. Zhang ◽  
S. H. Yang ◽  
T. Li ◽  
Y. J. Hou ◽  
Y. Li
Keyword(s):  
Extreme Ultraviolet ◽  
Null Point ◽  
Second Phase ◽  
Solar Dynamics Observatory ◽  
X Ray ◽  
Counterclockwise Direction ◽  
Solar Dynamics ◽  
Flare Ribbon ◽  
Two Phases ◽  
Two Jets

Context. The separation and elongation motions of solar flare ribbons have extensively been investigated. The degradation and disappearance of ribbons have rarely been explored. Aims. We report our multiwavelength observations of a C5.5 circular-ribbon flare associated with two jets (jet1 and jet2) on 2014 August 24, focusing on the fast degradation of the outer circular ribbon (CR). Methods. The flare was observed in ultraviolet (UV) and extreme-ultraviolet (EUV) wavelengths by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory spacecraft. Soft X-ray fluxes of the flare in 0.5−4 and 1−8 Å were recorded by the GOES spacecraft. Results. The flare, consisting of a short inner ribbon (IR) and outer CR, was triggered by the eruption of a minifilament. The brightness of IR and outer CR reached their maxima simultaneously at ∼04:58 UT in all AIA wavelengths. Subsequently, the short eastern part of the CR faded out quickly in 1600 Å but only gradually in EUV wavelengths. The long western part of the CR degraded in the counterclockwise direction and decelerated. The degradation was distinctly divided into two phases: phase I with faster apparent speeds (58−69 km s−1), and phase II with slower apparent speeds (29−35 km s−1). The second phase stopped at ∼05:10 UT when the western CR disappeared entirely. In addition to the outward propagation of jet1, the jet spire experienced untwisting motion in the counterclockwise direction during 04:55−05:00 UT. Conclusions. We conclude that the event can be explained by the breakout jet model. The coherent brightenings of the IR and CR at ∼04:58 UT may result from the impulsive interchange reconnection near the null point, whereas sub-Alfvénic slipping motion of the western CR in the counterclockwise direction indicates the occurrence of slipping magnetic reconnection. Another possible explanation of the quick disappearance of the hot loops that are connected to the western CR is that they are simply reconnected sequentially without the need for significant slippage after the null-point reconnection.

The Effect of Aberrant Rotation on Radiographic Patellar Height Measurement Using Canton-Deschamps Index: A Cadaveric Analysis

2021 ◽  
Author(s):  
Hailey P. Huddleston ◽  
Michael L. Redondo ◽  
William M. Cregar ◽  
David R. Christian ◽  
Charles P. Hannon ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Pairwise Comparison ◽  
Lateral Position ◽  
Axial Plane ◽  
Absolute Maximum ◽  
Height Measurement ◽  
Patella Height ◽  
Counterclockwise Direction ◽  
Significant Difference ◽  
Clinically Significant

AbstractThe Caton-Deschamps Index (CDI) is a measurement used to evaluate patella alta based on true lateral radiographs; however, no prior study has investigated how altering the degree of radiograph aberrancy affects CDI measurement. The primary and secondary purpose of this study was to evaluate effects of rotational radiographic changes on patella height measurements and compare these findings to MRI measurements, respectively. Five cadaver knees (n = 5) were utilized in this study. True lateral radiographs were obtained for each specimen by using a fluoroscopic C-arm machine. The C-arm was then altered in two planes (axial and coronal) in both the clockwise and counterclockwise direction and radiographs were taken at 5, 10, and 15 degrees of error from the true lateral position. A CDI measurement of each specimen was performed based on sagittal magnetic resonance imaging (MRI) slices and compared with radiographic CDI measurements. Three orthopedic surgeons measured the CDI for each radiograph and MRI performed. Interrater reliability and changes in CDI were analyzed. Clinically significant difference in CDI was set to 0.1. Mean intraclass correlation coefficient was high (≥0.7) at true lateral and at all varying degrees of error. When performing a pairwise comparison of mean CDI from the true lateral position to increasing degrees of error, statistically significant differences were observed in the axial plane. The largest change in CDI measurements was seen with rotational malposition in the axial plane and counterclockwise direction. No statistically significant differences in mean CDI were observed in the coronal plane. The change in CDI from the true lateral position reached an absolute maximum of at least 0.1 in all four scenarios at each tested degree of error. This study found that aberrant radiographic rotation in the axial plane resulted in a significantly different mean CDI measurement when compared with true lateral radiographs. All degrees of error in both directions and in both planes could have a clinically significant effect on CDI (≥0.1). Our findings confirm the importance of a perfect true lateral radiograph when measuring patella height.

SCANNER DESIGN SPECIFICITY FOR HELMET-MOUNTED TARGETING SYSTEM

2021 ◽  
Vol 156 (1) ◽  
pp. 29-37
Author(s):  
Volodymyr SENATOROV ◽  
Svitlana GLAZKOWA
Keyword(s):  
Angular Position ◽  
Design Principles ◽  
Geometric Parameters ◽  
The Other ◽  
Field Of View ◽  
Scanning Process ◽  
Counterclockwise Direction ◽  
Triangulation Method ◽  
Targeting Accuracy

Following design principles are important for helmet-mounted targeting systems. Two scanners on base of the polygonal reflector-type prisms forming the fanned field of view are fastened to head-up display. Three LEDs installed on pilot helmet form a plane, the normal of which is collinear to helmet indi-cator viewing line. Angles of LED bearings are measured with triangulation method and angular position of viewing line is calculat-ed. Two options for organization of scanning process are analyzed in the paper. In the first variant, one prism rotates in clockwise and the other in counterclockwise direction. In the second variant both prisms rotate in the same direction, clockwise for example. It is shown that if the prisms rotate in the same direction the targeting accuracy is greater. The algorithm developed for determination of targeting accuracy may be used to matching the rate of scanning and geometric parameters of helmet-mounted targeting system at prescribed accuracy of targeting.

The ultrastructure of Ulothrix mucosa. II. The flagellar apparatus of the zoospore

1986 ◽  
Vol 64 (1) ◽  
pp. 166-176 ◽  
Author(s):  
G. M. Lokhorst ◽  
W. Star
Keyword(s):  
Basal Body ◽  
Spatial Configuration ◽  
Rotational Symmetry ◽  
Flagellar Apparatus ◽  
Taxonomic Status ◽  
Proximal Region ◽  
Basal Bodies ◽  
Serial Sectioning ◽  
Counterclockwise Direction ◽  
Microtubular Roots

The actual spatial configuration of the flagellar apparatus of the quadriflagellate zoospore of Ulothrix mucosa Thuret has been reconstructed by serial sectioning analysis. This apparatus shows an architecture quite similar to that found in related Ulvophyceae. Common characteristics are the differently leveled basal body pairs; the 180° rotational symmetry of the flagellar apparatus; the proximal overlap of the upper basal bodies which are displaced with respect to each other in the counterclockwise direction; terminal caps; four cruciately arranged microtubular roots (R2, R4); a distinctly striated distal connecting fibre that interconnects the upper basal bodies; and striated bands (SB1) that join the R4s to the lower basal bodies. Specific features are the arrangement of the R4 in a three over one configuration when entering the proximal region of the flagellar apparatus; the differently shaped proximal sheaths and their association with a proximal sheath connecting band; the presence of two system II fibres (rhizoplasts) which arise from the lower basal body pair; the striated bands (SB2) that connect the R2s to the lower basal bodies; the distinct striation of the system I fibre, which is not only intimately associated with the R2, but also with the R4 (not earlier reported for an ulvophycean alga); and, finally, the relevant displacement of the lower basal body pair in a counterclockwise direction of approximately half a basal body diameter. In light of these findings the taxonomic status of the Ulotrichales as well as of the Ulvophyceae is discussed.

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