SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Distance

162

Vestibular inputs make a key contribution to the sense of one’s own spatial location. While the effects of vestibular stimulation on visuo-spatial processing in neurological patients have been extensively described, the normal contribution of vestibular inputs to spatial perception remains unclear. To address this issue, we used a line bisection task to investigate the effects of galvanic vestibular stimulation (GVS) on spatial perception, and on the transition between near and far space. Brief left-anodal and right-cathodal GVS or right-anodal and left-cathodal GVS were delivered. A sham stimulation condition was also included. Participants bisected lines of different lengths at six distances from the body using a laser pointer. Consistent with previous results, our data showed an overall shift in the bisection bias from left to right as viewing distance increased. This pattern suggests leftward bias in near space, and rightward bias in far space. GVS induced strong polarity dependent effects in spatial perception, broadly consistent with those previously reported in patients: left-anodal and right-cathodal GVS induced a leftward bisection bias, while right-anodal and left-cathodal GVS reversed this effect, and produced bisection bias toward the right side of the space. Interestingly, the effects of GVS were comparable in near and far space. We speculate that vestibular-induced biases in space perception may optimize gathering of information from different parts of the environment.

Concepts: Right-wing politics, Space, Political spectrum, Vestibular system, Perception, Distance, Galvanic Vestibular Stimulation, Left-wing politics

142

This study determined the population structure and genome-wide marker-trait association of agronomic traits of wheat for drought-tolerance breeding. Ninety-three diverse bread wheat genotypes were genotyped using the Diversity Arrays Technology sequencing (DArTseq) protocol. The number of days-to-heading (DTH), number of days-to-maturity (DTM), plant height (PHT), spike length (SPL), number of kernels per spike (KPS), thousand kernel weight (TKW) and grain yield (GYLD), assessed under drought-stressed and non-stressed conditions, were considered for the study. Population structure analysis and genome-wide association mapping were undertaken based on 16,383 silico DArTs loci with < 10% missing data. The population evaluated was grouped into nine distinct genetic structures. Inter-chromosomal linkage disequilibrium showed the existence of linkage decay as physical distance increased. A total of 62 significant (P < 0.001) marker-trait associations (MTAs) were detected explaining more than 20% of the phenotypic variation observed under both drought-stressed and non-stressed conditions. Significant (P < 0.001) MTA event(s) were observed for DTH, PHT, SPL, SPS, and KPS; under both stressed and non-stressed conditions, while additional significant (P < 0.05) associations were observed for TKW, DTM and GYLD under non-stressed condition. The MTAs reported in this population could be useful to initiate marker-assisted selection (MAS) and targeted trait introgression of wheat under drought-stressed and non-stressed conditions, and for fine mapping and cloning of the underlying genes and QTL.

Concepts: Length, Evolution, Distance, Wheat, Linkage disequilibrium, Phenotype, Genetics, Gene

51

Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight.This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later.The majority of patients (n = 6962) were injured during daylight hours and bright sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during bright sunlight than normal weather (95% confidence interval: 9-24, P < 0.001). The increased risk was accentuated in the early afternoon, disappeared at night, extended to patients with different characteristics, involved crashes with diverse features, not apparent with cloudy weather, and contributed to about 5000 additional patient-days in hospital. The increased risk extended to patients with high crash severity as indicated by ambulance involvement, surgical procedures, length of hospital stay, intensive care unit admission, and patient mortality. The increased risk was not easily attributed to differences in alcohol consumption, driving distances, or anomalies of adverse weather.Bright sunlight is associated with an increased risk of a life-threatening motor vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash.

Concepts: Distance, Cloud, Solar System, Sun, Normal distribution, Wind, Driver's license, Hospital

51

This study looked at whether drivers overtaking a bicyclist changed the proximities of their passes in response to the level of experience and skill signalled by the bicyclist’s appearance. Seven outfits were tested, ranging from a stereotypical sport rider’s outfit, portraying high experience and skill, to a vest with ‘novice cyclist’ printed on the back, portraying low experience. A high-visibility bicycling jacket was also used, as were two commercially available safety vests, one featuring a prominent mention of the word ‘police’ and a warning that the rider was video-recording their journey, and one modelled after a police officer’s jacket but with a letter changed so it read ‘POLITE’. An ultrasonic distance sensor recorded the space left by vehicles passing the bicyclist on a regular commuting route. 5690 data points fulfilled the criteria for the study and were included in the analyses. The only outfit associated with a significant change in mean passing proximities was the police/video-recording jacket. Contrary to predictions, drivers treated the sports outfit and the ‘novice cyclist’ outfit equivalently, suggesting they do not adjust overtaking proximity as a function of a rider’s perceived experience. Notably, whilst some outfits seemed to discourage motorists from passing within 1m of the rider, approximately 1-2% of overtakes came within 50 cm no matter what outfit was worn. This suggests there is little riders can do, by altering their appearance, to prevent the very closest overtakes; it is suggested that infrastructural, educational or legal measures are more promising for preventing drivers from passing extremely close to bicyclists.

Concepts: Distance, Automobile, Utility cycling, Sustainable transport, Segregated cycle facilities, Cycling, Bicycle

39

Missing pet cats are often not found by their owners, with many being euthanized at shelters. This study aimed to describe times that lost cats were missing for, search methods associated with their recovery, locations where found and distances travelled. A retrospective case series was conducted where self-selected participants whose cat had gone missing provided data in an online questionnaire. Of the 1210 study cats, only 61% were found within one year, with 34% recovered alive by the owner within 7 days. Few cats were found alive after 90 days. There was evidence that physical searching increased the chance of finding the cat alive (p = 0.073), and 75% of cats were found within 500 m of the point of escape. Up to 75% of cats with outdoor access traveled 1609 m, further than the distance traveled by indoor-only cats (137 m; p ≤ 0.001). Cats considered to be highly curious were more likely to be found inside someone else’s house compared to other personality types. These findings suggest that thorough physical searching is a useful strategy, and should be conducted within the first week after cats go missing. They also support further investigation into whether shelter, neuter and return programs improve the chance of owners recovering missing cats and decrease numbers of cats euthanized in shelters.

Concepts: Distance, Ownership, Retrospective, Personality type, Searching, Neutering, English-language films, Cat

31

The purpose of this study was to compare the distances covered during a 11-a-side soccer match after players had consumed either a high carbohydrate (CHO) or a low CHO diet. Twenty two male professional soccer players formed two teams (A and B), of similar age, body characteristics, and training experience. The two teams played against each other twice with a week interval between. For 3.5 days before the 1 match the players of team A followed a high CHO diet that provided 8 g CHO per Kg body mass (BM) (HC), whereas team B players followed a low CHO diet that provided 3 g CHO / Kg BM (LC) for the same time period. Before the 2 match the dietary treatment was reversed and followed for the same time period. Training during the study was controlled and distances covered were measured using GPS technology. Every player covered a greater total distance in HC compared to the distance covered in LC (HC: 9380 ± 98 m vs. LC: 8077 ± 109 m; p< 0.01). All distances covered from easy jogging (7.15 Km.h) to sprinting (24.15 Km.h) were also higher in HC compared to LC (p< 0.01). When players followed the HC treatment won the match (Team A vs. Team B: 3-1 for the first game and 1-2 for the 2 game). The HC diet probably helped players to cover a greater distance compared to LC. Soccer players should avoid eating a low (3 g CHO / Kg BM) CHO diet 3-4 days before an important soccer match and have a high CHO intake that provides at least 8 g CHO / Kg BM.

Concepts: Obesity, Players, Periodization, Metric space, Distance, Diets, Nutrition, Low-carbohydrate diet

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To evaluate the quality of evidence reporting, breadth of coverage, and timeliness of content updating of 10 selected online medical texts.

Concepts: Systematic review, Distance, Geometry

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Abstract The aims of this study were to examine the 1) individual playing area, 2) length and width of the rectangle encompassing the individual playing area and 3) distance between the goalkeepers and their nearest team-mates during professional soccer matches and compare these to previously reported pitch sizes for small-sided games (SSGs). Data were collected from four Spanish La Liga matches of the 2002-03 season, and notated post-event using the Amisco® system. The pitch sizes obtained from real matches were smaller and different from those used previously for SSGs. In addition, the current pitch sizes show significant (P < 0.001) effect of ball location in all variables examined. For example, overall individual playing area (F [5, 2562] = 19.99, P < 0.001, η(2 )= 0.04) varied significantly across six different zones of the pitch. Based on these empirical results, pitch sizes with individual playing areas ranging from 65 m(2) to 110 m(2) and length to width ratio of 1:1 and 1:1.3 are generally recommended for training tactical aspects according to different phases of play. It is possible to design SSGs with a more valid representation of the tactical conditions experienced in full-size matches and their use may improve the training effect of tactical aspects of match performance in soccer.

Concepts: Distance, Real Oviedo, Real Valladolid, Real Zaragoza, Real Madrid C.F., Real Sociedad, Height, La Liga

28

We consider the problem of categorizing video sequences of dynamic textures, i.e., nonrigid dynamical objects such as fire, water, steam, flags, etc. This problem is extremely challenging because the shape and appearance of a dynamic texture continuously change as a function of time. State-of-the-art dynamic texture categorization methods have been successful at classifying videos taken from the same viewpoint and scale by using a Linear Dynamical System (LDS) to model each video, and using distances or kernels in the space of LDSs to classify the videos. However, these methods perform poorly when the video sequences are taken under a different viewpoint or scale. In this paper, we propose a novel dynamic texture categorization framework that can handle such changes. We model each video sequence with a collection of LDSs, each one describing a small spatiotemporal patch extracted from the video. This Bag-of-Systems (BoS) representation is analogous to the Bag-of-Features (BoF) representation for object recognition, except that we use LDSs as feature descriptors. This choice poses several technical challenges in adopting the traditional BoF approach. Most notably, the space of LDSs is not euclidean; hence, novel methods for clustering LDSs and computing codewords of LDSs need to be developed. We propose a framework that makes use of nonlinear dimensionality reduction and clustering techniques combined with the Martin distance for LDSs to tackle these issues. Our experiments compare the proposed BoS approach to existing dynamic texture categorization methods and show that it can be used for recognizing dynamic textures in challenging scenarios which could not be handled by existing methods.

Concepts: Logistic map, Dynamical systems theory, Dynamical systems, Dynamical system, Dimension, Distance, Mathematics

28

PURPOSE: This study compared the status of suture knots immediately after repair and after shoulder motion to evaluate the possibility of movement-induced knot migration to a location nearer the glenoid. METHODS: We included 10 shoulders from 5 cadavers in the study. After posterior capsulotomy, a Bankart lesion was created. A capsulolabral repair was then performed with 3 knot-tying suture anchors. All knots were positioned on the capsular side, far from the articular surface. After the repair was complete, a photograph was taken with a metal rod placed to reference absolute distance. After passive pendulum motion was applied, another photograph was taken. The length of the suture strand from the knot base to the anchor insertion site was measured during both the initial repair and post-motion periods. RESULTS: Initial distances were 4.83 ± 1.09 mm for the inferior knot, 4.70 ± 0.97 mm for the middle knot, and 3.84 ± 1.25 mm for the superior knot. After motion, the distances were 3.52 ± 1.21 mm (P = .01), 3.07 ± 0.81 mm (P < .001), and 2.69 ± 1.18 mm (P = .016), respectively. Additional observations showed changes in direction and security of the knot. The change in knot direction from an initial orientation facing the capsular side to a new orientation facing the glenoid was observed in 5 of 10 inferior, 7 of 10 middle, and 6 of 10 superior knots. In addition, knot loosening was noted for the last half-hitches in 4 inferior knots and 1 middle knot. CONCLUSIONS: Intentional placement of suture knots away from the joint surface was not maintained after motion at the shoulder. CLINICAL RELEVANCE: Movement-induced knot migration may be detrimental to articular cartilage in the event that a knot becomes interposed between the glenoid and humeral head.

Concepts: Glenoid labrum, Distance, Scapula, Bone, Humerus, Knee, Skeletal system, Shoulder