Arrow Length Research Articles

Collection, Characterization and Diversity Analysis of New Wild Sugarcane Germplasm Collected from Western Ghats: A Rich Biodiversity Spot in India

Western Ghats in India with diverse climatic condition and different types of vegetation covering the states of Tamil Nadu, Kerala, Karnataka, Goa and Maharashtra, is a biodiversity hot spot. This important area was not explored earlier for sugarcane wild genetic resources. Targeted explorations in these areas resulted in the collection of 39 Saccharum spontaneum (3 in Tamil Nadu, 5 in Kerala, 9 in Karnataka, 4 in Goa and 18 in Maharashtra), 11 Erianthus arundinaceus (3 in Tamil Nadu, 6 in Kerala, 1 in Goa and 1 in Maharashtra), 3 Erianthus bengalense (1 in Tamil Nadu and 2 in Goa) and 2 Saccharum officinarum (one each in Tamil Nadu and Karnataka). S. spontaneum was distributed throughout the regions, while Erianthus species were abundant in Kerala, Goa and Tamil Nadu. S. spontaneum exhibited wide variation for different traits like plant height (312 to 45 cm), leaf length (102 to 21 cm), leaf width (1.3 to 0.2 cm), peduncle length (59 to 16 cm), arrow length (46 to 14 cm), internode length (15.3 to 4.5) and cane diameter (0.8 to 0.3 cm). E. arundinaceus also showed wide range for plant height (631 to 192 cm), leaf width (5.7 to 3.8 cm) and internode length (8.5 to 17 cm). Cluster analysis grouped the germplasm into four clusters, and 97% of the S. spontaneum grouped into Cluster IV. Cluster III had three accessions and all were E. bengalense, while most of the E. arundinaceus accessions were grouped into Cluster I. Genetic diversity of the new germplasm collected and their utilization in sugarcane genetic improvement programme are discussed.

Optically tunable spin texture of the surface state for Bi2Se3 and SmB6 topological insulators.

The spin texture of the surface state for topological insulators can be manipulated by the polarization of light, which might play a potential role in the applications in spintronics. However, the study so far in this direction mainly focuses on the classical light-topological-insulators interactions; TIs coupled to quantized light remains barely explored. In this paper, we develop a formalism to deal with this issue of spin texture of the surface state for topological insulators (for example Bi2Se3 and SmB6) irradiated by a quantum field, and we find that the coupling between an electron and a single-mode quantum field modulates only the arrow length that represents the spin polarization of a topological surface state. Specifically, when the photon number of a single-mode quantum field is fixed, the azimuth angle between the quantum light and the material surface manipulates the spin textures along the constant energy contour rotating (clockwise or counterclockwise) around the high symmetry point, and the polar angle controls the magnitude of the spin polarization. These results are quite different from the situation where an external field is not applied to an electron in a crystal or where a classical external field is utilized to control the spin polarization of a photoemitted electron in a vacuum. Our results have potential applications in quantum optics and condensed-matter physics.

Postural stability, clicker reaction time and bow draw force predict performance in elite recurve archery

Recurve archery is an Olympic sport that requires extreme precision, upper body strength and endurance. The purpose of this research was to quantify how postural stability variables both pre- and post-arrow release, draw force, flight time, arrow length and clicker reaction time, collectively, impacted on the performance or scoring outcomes in elite recurve archery athletes. Thirty-nine elite-level recurve archers (23 male and 16 female; mean age = 24.7 ± 7.3 years) from four different countries volunteered to participate in this study prior to competing at a World Cup event. An AMTI force platform (1000Hz) was used to obtain centre of pressure (COP) measurements 1s prior to arrow release and 0.5s post-arrow release. High-speed footage (200Hz) allowed for calculation of arrow flight time and score. Results identified clicker reaction time, draw force and maximum sway speed as the variables that best predicted shot performance. Specifically, reduced clicker reaction time, greater bow draw force and reduced postural sway speed post-arrow release were predictors of higher scoring shots. It is suggested that future research should focus on investigating shoulder muscle tremors at full draw in relation to clicker reaction time, and the effect of upper body strength interventions (specifically targeting the musculature around the shoulder girdle) on performance in recurve archers.

Application of weight method based on canonical correspondence analysis for assessment of Anatidae habitat suitability: A case study in East Dongting Lake, Middle China

Habitat suitability assessment is one of the essential steps in habitat conservation and restoration. A weight method, which used the length of arrow in the result of canonical correspondence analysis (CCA) to determine the weight of the environmental variables, was developed to evaluate the Anatidae habitat suitability in East Dongting Lake. Based on descriptive waterfowl statistics from field observation data, Anatidae were selected as the representative waterfowl by the dominance. And then five environmental variables were identified by the correlation analysis as having important effects on the presence/absence of Anatidae habitat suitability. The Anatidae habitat suitability was evaluated by the new weight method. The results showed that the area of highly suitable habitat and moderately suitable habitat were 21.8% and 48.5%, respectively. Only small area was unsuitable habitat (9.3%). The survey data of Anatidae from 2006 to 2011 in East Dongting Lake were used to test the validity of the assessment results. It was concluded that the five environmental variables could well explain the results of Anatidae habitat suitability. The weight method based on CCA was feasible in assessment of Anatidae habitat suitability.

Two independent sources of anisotropy in the visual representation of direction in 2-D space

It is known that visual direction representation is more accurate for cardinal directions compared to oblique, a phenomenon named the "oblique effect". It has been hypothesized that there are two sources of oblique effect, a low level one confined to vision and a high level one extending to different modalities and corresponding to higher cognitive processes. In this study directional error (DE) was measured when normal individuals tried to align the direction of an arrow presented in the center of a computer monitor to the direction of a peripheral target located in one of 32 directions equally spaced on an imaginary circle of 60 mm radius. Task difficulty was manipulated by varying arrow length (15, 30, 45 and 60 mm). By measuring mean DE and its variance we identified two independent sources of the oblique effect. A low level oblique effect was manifested in higher accuracy or equivalently lower variance of DE in the alignment for cardinal orientations compared to oblique. A second oblique effect was manifested measuring mean DE resulting in space expansion in the vicinity of cardinal directions and space contraction in the vicinity of oblique directions. Only this latter source of oblique effect was modulated by arrow length as predicted from a theoretical model postulating that this oblique effect is produced by a cognitive process of 2-D space categorization.

プロジェクタを用いて次の動作を予告表示する機能をもつ移動ロボットの開発

This paper discusses the mobile robot PMR-5 with the preliminary-announcement and display function which indicates the forthcoming operations to the people near the robot by using a projector. The projector is set on a mobile robot and a 2-dimensional frame is projected on a running surface. In the frame, not only the scheduled course but also the states of operation can be clearly announced as the information about movement. We examine the presentation of the states of operation such as stop or going back including the time information of the scheduled course on the developed robot. Scheduled course is expressed as the arrows considering the intelligibility at sight. Arrow expresses the direction of motion directly and the length of arrow can announce the speed of motion. Operation until 3-second-later is indicated and three arrows classified by color for each second are connected and displayed so these might show the changing of speed during 3-second period. The sign for spot revolution and the characters for stop and going back are also displayed. We exhibited the robot and about 200 visitors did the questionnaire evaluation. The average of 5-stage evaluation is 4.5 points and 3.9 points for the direction of motion and the speed of motion respectively. So we obtained the evaluation that it is intelligible in general.

Unsteady Wing Characteristics AtLow Reynolds Number

Unsteady Wing Characteristics AtLow Reynolds Number

Mechanical Properties of Bioabsorbable Meniscal Arrows as a Function of Tear Location

Background Ex vivo studies have established that arrow fixation of meniscal tears is inferior to vertical sutures and is dependent on arrow length, although the influence of tear location is not known. Hypothesis Arrow length and tear location influence the mechanical properties of meniscal arrows. Study Design Controlled laboratory study. Methods A longitudinal incision was created either 2 mm or 7 mm from the periphery in 70 bovine medial menisci. Each was repaired with a meniscal arrow (10, 13, or 16 mm) or a single vertical suture and subjected to load-to-failure testing and video- graphic analysis. Results Mode of failure (P < .0001), maximum force (P < .0001), stiffness (P < .01), 2-mm gap force (P < .03), and ultimate gap formation (P < .002) were all directly related to arrow length. Sixteen-mm arrows and suture exhibited similar, superior mechanical properties. Tear location significantly influenced properties of 10-mm and 16-mm but not 13-mm arrows. Ten-millimeter arrows displayed the worst performance. Conclusions Mechanical properties of meniscal arrows depend on tear location and arrow length. Clinical Relevance Sixteen-millimeter arrows are a possible alternative to suture for repair of central tears. Thirteen-millimeter arrows may be effective for central and peripheral tears. Ten-millimeter arrows should not be used.

Influence of visual perception on spatial coding of saccadic eye movements and fixation

The Müller-Lyer illusion produces differences in visual length perception when lines of equal length are presented as double-arrows with inward-pointing and outward-pointing arrowheads, respectively. The aim of this study was to investigate the influence of length perception on the amplitude of saccadic eye movements and on postsaccadic fixation positions. Video recordings of eye movements were obtained from 35 healthy volunteers (age: 20-30 years) while they scanned the endpoints of Müller-Lyer targets. The targets were presented in horizontal and vertical orientations with an arrow length of 15°. Fixation periods between the saccades were adjusted at 1 s and 4 s. The final saccadic amplitudes between the endpoints of Müller-Lyer figures reflect the visually perceived length differences: lines with outward-pointing arrowheads were scanned with smaller saccades than lines with inward-pointing arrowheads. This bias in final saccadic amplitude was equal in both the horizontal and vertical target orientations as well as for 1-s and 4-s fixation periods. Postsaccadic drift after initial saccadic movements reduced the effect of the Müller-Lyer illusion depending on arrowhead and target orientation: outward-pointing horizontal arrows caused hypometric pulses, while inward-pointing vertical arrows caused hypermetric pulses. The results of this study demonstrate that spatial coding of both saccadic eye movements and fixation is strongly influenced by visual perception. While the influence of the Müller-Lyer illusion on final saccadic amplitudes did not depend on target orientation or fixation period, an additional pulse-step mismatch appeared in the horizontal (hypometria) and vertical (hypermetria) direction.

Refining Crossbow Deployment Techniques of Suction Cup Attached Tags for Cetacean Field Studies

Remote deployment of non-invasive suction cup attached tags on free ranging cetaceans continues to be problematic for researchers. In an effort to increase the chances of success, the factors affecting the velocity, range, and drop of crossbow deployed tags were examined. The exit velocity of a tag is primarily governed by the tag's weight and can be predicted for a particular bow. Higher exit velocities correspond to a smaller drop for a given range. Compound crossbows are able to achieve higher exit velocities and hence longer ranges for a given tag weight than simple re-curve bows of the same draw weight. Varying the position of the tag's center of mass has a greater effect on the drop of the tag than arrow length, shaft material, diameter or wall thickness. Raising the height of the center of mass increases the induced departure angle of the tag, giving the tag a vertical velocity component. This upward velocity helps to counteract negative gravitational forces and extends the range of the tag. Thus, researchers could potentially manipulate various parameters of their arrow/tag system to increase the range of their tag and their chances of successfully tagging cetaceans in the field.