bluuebunny/crossref_metadata_2025_split huggingface dataset:
Horizontal and Vertical Composite Effects in Novel Faces
Authors: Costen N P , Kato T , Craw I G , Akamatsu S 
Published: December 2015

The composite effect, where the recognition of the upper half of a face is disrupted by a discrepant lower half relative to an isolated half-face, without a corresponding effect for vertical half-faces, provides a ready method of investigating configural information in face recognition. In previous studies purely photographic techniques have been used for composite construction. We investigated the effects of more face-like stimuli, constructed by morphing techniques. Subjects were trained to identify frontal Japanese faces, and tested on recognition on marked upper, lower, left, and right halves, both as half-faces and with distractors. While response accuracy for the upper and lower composites was lower than those for the relevant halves, there was no such effect for the right - left composites. A familiarity design was used in the second experiment to replicate this result. In the third experiment quarter-faces (top left - bottom right facial quadrants) were used to control for the information present. We found a strong composite effect for the right - left composites, and weaker ones for the top - bottom and quarter composites. In the fourth experiment we examined whether this effect was dependent on the presence of the quarter-composites by presenting them in a second block but found no effect of this manipulation. It thus appears that although there is a composite effect with faces composed in a shape-free manner, this effect is unstable. Under certain circumstances subjects may convert from a top - bottom relational processing strategy to a right - left strategy. The information used, even with a constant task, is dependent upon the variability of the images involved.
Illuminant and Viewpoint Biases from Embossed Surfaces
Authors: Mamassian P , Landy M S 
Published: December 2015

The human visual system uses a-priori constraints for the estimation of surface shape from images. We propose here a robust paradigm to study individual observers' assumptions about the illuminant and viewpoint positions. In the study of illumination, the stimuli consisted of parallel, sinusoidally shaped, striped regions, alternating between wide and narrow. Narrow stripes alternating between white and black separated the uniform grey stripes, representing slanted edges in light and in shadow. The stimulus had the shape-from-shading ambiguity: either the wide or the narrow stripes could be seen as ‘in-front’, consistent with different assumed tilts of the illuminant. In a brief flash of a randomly oriented stimulus, observers stated whether the narrow or wide stripes appeared in the foreground. The results showed a strong bias for a light-from-above-left assumption (as in Howard et al, 1990 Perception19 523 – 530; Sun and Perona, 1996 Investigative Ophthalmology and Visual Science37 935). This bias was 20 to 30 deg to the left of vertical. Slower reaction times were obtained for more ambiguous figures. The same shape judgment task was used with an unshaded stimulus where the only depth cue was image contour. The same curvy, striped figure was portrayed with image contours at the edges of the stripes, as well as surface markings orthogonal to the depth variation, resulting in a shape-from-contour cue. We have previously reported indirect evidence for a bias of viewpoint above the object, that is observers interpret surface normals as pointing upward (Mamassian, 1995 Perception24 Supplement, 35). Our observers' shape judgments were consistent with this bias.
Global versus Local Cues for Route Finding in Virtual Environments
Authors: Geiger S , Gillner S , Mallot H A 
Published: December 2015

Motivated by the results of Gillner and Mallot (1996 Perception25 Supplement, 93) implying that local views are basic elements for a spatial representation, we studied the role of global versus local landmarks using a route-finding task. Our hypotheses were: (i) A global navigation strategy relying on allocentric movement decisions is used, eg “go from this place towards the chapel on the hill”, or (ii) a local navigation strategy based on view—movement associations is used, eg “at the red building go right”. We performed an experiment in a computer graphics town based on a hexagonal grid structure. At each intersection we placed three different buildings. We also provided global direction information by placing six global landmarks distributed equally along a mountain range. Subjects had to learn the back and forth route between two buildings, not knowing that after a learning phase the location of buildings at a particular junction would be changed. These changes produced conflicting global and local information. In the test-phase, the subject approached individual junctions in both learned and novel directions and the movement decisions were recorded. In a control condition with unchanged places twenty subjects made correct decisions for 136 of 160 movements. In the experimental conflict condition 123 decisions were consistent with a local and 37 with a global strategy. This supports our previous finding that local views play a dominant role in making route judgements. Approaching a junction from a learned direction leads to more accurate movement decisions than approaching it from a novel direction, even if the global landmarks are available, which provides further support for the local-view hypothesis.
Radial Asymmetry in the Sensitivity of the Blue Mechanism
Authors: Vassilev A 
Published: December 2015

In the human retina, the density of blue cones is lower along the nasal horizontal meridian (Curcio et al, 1991 Journal of Comparative Neurology312 610 – 624) than along the other cardinal meridians, but this finding might reflect interpolation between widely spaced data points rather than actual radial asymmetry. Available psychophysical data on the sensitivity of the blue mechanism do not address this question. In the present study, subjects had to detect a blue test stimulus (wavelength range at half-amplitude 425 – 480 nm, diameter 24 min arc) presented against yellow background (wavelength above 550 nm, 200 cd m−2). The test stimulus was flickering at 5.7 Hz around a mean level of 3 cd m−2 within a Gaussian temporal window with a time constant of 0.2 s. Foveal and parafoveal sensitivity was measured along the vertical and horizontal meridians. Radial asymmetry in the sensitivity of the blue mechanism was observed, in that the known foveal insensitivity also involved part of the nasal horizontal meridian. The dip in the sensitivity map at the fovea was narrower along the vertical than along the horizontal meridian. While these data are in good agreement with the blue-cone density map, the dip in sensitivity is wider than the depression in the density of blue cones at the fovea. Both screening by yellow pigment and effects of stimulus size might contribute to this discrepancy.
Gabor-based Coding and Facial Similarity Perception
Authors: Lyons M J , Morikawa K , Akamatsu S 
Published: December 2015

Little is known about how facial representation in the face-selective areas of inferotemporal cortex is built up from the output of earlier visual areas such as primary visual cortex (area V1). We report work on a model of perceived facial similarity based on topographically ordered aggregates of localised, oriented, and spatial-frequency-selective receptive fields characteristic of V1 cells. The receptive fields are approximated with a set of Gabor filters. This Gabor-based code allows representation of the fine differences in texture and configuration needed for facial discrimination processes. Lyons and Morikawa (1996 Investigative Ophthalmology and Visual Science37 910), showed that Gabor-based similarity is a good predictor of facial similarity for comparisons of fairly similar faces but not sufficient to model experience-dependent effects such as the ‘other race effect’. Here we report results of a study on the effects of image negation on facial similarity perception. Negation of image gray levels interferes with face recognition (Bruce and Lanton, 1994 Perception23 803 – 822) while preserving 2-D facial-shape information. The Gabor similarity measure models non-endstopped complex cells of V1 and is not affected by image negation. One group of subjects judged similarity among a set of normal gray-scale facial images while another group judged similarity between negative images of the same stimuli. Agreement between the model and human subjects did not decrease with image negation. Moreover, human similarity ratings between negative faces were strongly correlated with those between positives. These results support Gabor-based similarity as a model for facial similarity perception.
Speed Discrimination in Luminance and Colour Stimuli as a Function of Contrast
Authors: Wuerger S M , Morgan A H 
Published: December 2015

We measured speed discrimination for isoluminant red - green and luminance-defined moving stimuli. The horizontal profile of the stimuli was a Gabor function with a carrier frequency of 2 cycles deg−1. The standard stimulus was a luminance stimulus with a fixed speed of 2 deg s−1 and a fixed contrast of 0.1. The comparison stimuli were either luminance stimuli (cone contrasts: 0.05, 0.1, 0.2, 0.4) or chromatic stimuli (cone contrasts: 0.025, 0.05, 0.1). The speed of the comparison stimuli was varied by an adaptive procedure. After each trial the observer indicated which of the 2 intervals contained the slower moving stimulus. The stimuli always moved horizontally and the direction was chosen randomly at each trial. The main findings were: (i) For luminance stimuli, the perceived speed was independent of contrast (ranging from 0.1 to 0.4). For colour stimuli, the perceived speed increased with contrast for two out of four observers. (ii) The sensitivity for speed discrimination was independent of contrast for luminance and for colour stimuli. (iii) There was no consistent difference in speed discrimination sensitivity between colour and luminance stimuli when the stimuli were equated in cone contrast.
Perception of Self-Motion Induced by Moving-Dot Patterns: The Interaction of the Stimulating Area and the Speed of the Pattern
Authors: Kano C 
Published: December 2015

A linear moving-dot pattern was presented to observers to induce self-motion. A stimulating circular area of more than 28.1 deg diameter induced self-motion perfectly, and even areas ranging from 5.7 deg to 11.4 deg diameter were able to elicit self-motion (Kano, 1995 Perception24 Supplement, 108). In the present study the interactive effects of the size of the stimulating area and the speed of the moving pattern on the perception of self-motion were examined. Random-dot patterns were moved downward in a circular area on a screen in a dark room. The diameters of the circular area were 5.7, 11.4, 22.6, and 43.6 deg. The speeds of the dot pattern were 9.49, 18.85, 28.07, 36.73, and 45.08 deg s−1. Observers were twenty-six students of Keio University. When the size of the area became larger and the dot pattern moved faster, self-motion was generally induced with shorter latencies. However, a significant interaction was found between size and speed; for the smallest area (5.7 deg diameter circle) latency was shorter at the lower speeds (9.49 to 28.07 deg s−1) than at the higher speeds (36.73 and 45.08 deg s −1). For the 11.4 deg diameter circle speed had no effect on latency. For the 22.6 deg diameter circle, however, latency decreased with increasing speed. For the 43.6 deg diameter circle latency was very short and constant under the four higher speeds, but remained considerably longer at the lowest speed. The results show that the effect of speed depends on the size of the stimulating area. When the size was large enough, speed had little effect on the latency of self-motion.
Infecting Pacific Herring with Ichthyophonus sp. in the Laboratory
Authors: Hershberger P. K. , Hart L. M. , MacKenzie A. H. , Yanney M. L. , Conway C. M. , Elliott D. G. 
Published: December 2015

Abstract
The protistan parasite Ichthyophonus sp. occurs in coastal populations of Pacific Herring Clupea pallasii throughout the northeast Pacific region, but the route(s) by which these planktivorous fish become infected is unknown. Several methods for establishing Ichthyophonus infections in laboratory challenges were examined. Infections were most effectively established after intraperitoneal (IP) injections with suspended parasite isolates from culture or after repeated feedings with infected fish tissues. Among groups that were offered the infected tissues, infection prevalence was greater after multiple feedings (65%) than after a single feeding (5%). Additionally, among groups that were exposed to parasite suspensions prepared from culture isolates, infection prevalence was greater after exposure by IP injection (74%) than after exposure via gastric intubation (12%); the flushing of parasite suspensions over the gills did not lead to infections in any of the experimental fish. Although the consumption of infected fish tissues is unlikely to be the primary route of Ichthyophonus sp. transmission in wild populations of Pacific Herring, this route may contribute to abnormally high infection prevalence in areas where juveniles have access to infected offal.
Received June 25, 2015; accepted September 12, 2015
Comparative studies on the fish-killing activities of Chattonella marina isolated in 1985 and Chattonella antiqua isolated in 2010, and their possible toxic factors
Authors: Cho Kichul , Sakamoto Jun , Noda Tatsuki , Nishiguchi Tomoki , Ueno Mikinori , Yamasaki Yasuhiro , Yagi Motoaki , Kim Daekyung , Oda Tatsuya 
Published: December 2015

Abstract
Chattonella antiqua isolated in 2010 showed extremely more potent fish-killing activities against red sea bream, Japanese horse mackerel, and blue damselfish than those of Chattonella marina isolated in 1985. Chemiluminescence and electron spin resonance (ESR) analyses suggested greater reactive oxygen species (ROS)-producing activity of C. antiqua than that of C. marina. Sodium benzoate, a hydroxyl radical scavenger, significantly suppressed the fish-killing activity of C. antiqua on blue damselfish. The chlorophyll level in the gill tissue of blue damselfish exposed to flagellate cells increased along with the exposure time, and the cell count of gill-associated C. antiqua estimated with chlorophyll level was higher than that of C. marina. These results suggest that the ROS-producing activity and affinity of Chattonella cells to the gill surface may be important factors influencing the fish-killing activity of Chattonella species.
Canonical symplectic particle-in-cell method for long-term large-scale simulations of the Vlasov–Maxwell equations
Authors: Qin Hong , Liu Jian , Xiao Jianyuan , Zhang Ruili , He Yang , Wang Yulei , Sun Yajuan , Burby Joshua W. , Ellison Leland , Zhou Yao 
Published: December 2015

Abstract
Particle-in-cell (PIC) simulation is the most important numerical tool in plasma physics. However, its long-term accuracy has not been established. To overcome this difficulty, we developed a canonical symplectic PIC method for the Vlasov–Maxwell system by discretising its canonical Poisson bracket. A fast local algorithm to solve the symplectic implicit time advance is discovered without root searching or global matrix inversion, enabling applications of the proposed method to very large-scale plasma simulations with many, e.g. 109, degrees of freedom. The long-term accuracy and fidelity of the algorithm enables us to numerically confirm Mouhot and Villani’s theory and conjecture on nonlinear Landau damping over several orders of magnitude using the PIC method, and to calculate the nonlinear evolution of the reflectivity during the mode conversion process from extraordinary waves to Bernstein waves.
Fishing impacts on benthic ecosystems: an introduction to the 2014 ICES symposium special issue
Authors: Buhl-Mortensen Lene , Neat Francis , Koen-Alonso Mariano , Hvingel Carsten , Holte Børge 
Published: December 2015

Abstract
Understanding the impacts of fishing on the seabed is a basic requirement for ecosystem-based marine management. It is only recently that we have begun understanding how fisheries-driven perturbations affect ecosystem function, biodiversity, productivity, and resilience. Technical solutions aimed at minimizing seabed impacts are starting to appear, but their efficacy remains to be demonstrated. In 2014, ICES held a symposium on the effects of fishing on benthic fauna, habitat, and ecosystem function, in Tromsø, Norway. The main goals of the symposium were to summarize current understanding of the physical and biological effects of fishing activities on benthic ecosystems, and to review the diversity of technical measures currently available to mitigate these effects. Here, we briefly describe the background to the scientific symposium and highlight the main contributions.
Genetic recombination as DNA repair
Authors: Parkhomchuk Dmitri , Shadrin Alexey , McHardy Alice C. 
Published: December 2015

AbstractMaintenance of sexual reproduction and genetic recombination imposes physiological costs when compared to parthenogenic reproduction, most prominently: for maintaining the corresponding (molecular) machinery, for finding a mating partner, and through the decreased fraction of females in a population, which decreases the reproductive capacity. Based on principles from information theory, we have previously developed a new population genetic model, and applying it in simulations, we have recently hypothesized that all species maintain the maximum genomic complexity that is required by their niche and allowed by their mutation rate and selection intensity. Applying this idea to the complexity overhead of recombination maintenance, its costs must be more than compensated by an additional capacity for complexity in recombining populations. Here, we show a simple mechanism, where recombination helps to maintain larger biases of alleles frequencies in a population, so the advantageous alleles can have increased frequency. This allows recombining populations to maintain higher fitness and phenotypic efficiency in comparison with asexual populations with the same parameters. Random mating alone already significantly increases the ability to maintain genomic and phenotypic complexity. Sexual selection provides additional capacity for this complexity. The model can be considered as a unifying synthesis of previous hypotheses about the roles of recombination in Muller's ratchet, mutation purging and Red Queen dynamics, because the introduction of recombination both increases population frequencies of beneficial alleles and decreases detrimental ones. In addition, we suggest simple explanations for niche-dependent prevalence of transient asexuality and the exceptional asexual lineage ofBdelloid rotifers.
Genomic and Chemical Diversity inCannabis
Authors: Lynch Ryan C. , Vergara Daniela , Tittes Silas , White Kristin , Schwartz C.J. , Gibbs Matthew J. , Ruthenburg Travis C. , deCesare Kymron , Land Donald P. , Kane Nolan C. 
Published: December 2015

AbstractPlants of theCannabisgenus are the only producers of phytocannabinoids, terpenoid compounds that strongly interact with evolutionarily ancient endocannabinoid receptors shared by most bilaterian taxa. For millennia, the plant has been cultivated for these compounds, but also for food, rope, paper, and clothing. Today, specialized varieties yielding high-quality textile fibers, nutritional seed oil or high cannabinoid content are cultivated across the globe. However, the genetic identities and histories of these diverse populations remain largely obscured. We analyzed the nuclear genomic diversity among 340Cannabisvarieties, including fiber and seed oil hemp, high cannabinoid drug-types and feral populations. These analyses demonstrate the existence of at least three major groups of diversity, with European hemp varieties more closely related to narrow leaflet drug-types (NLDT) than to broad leaflet drug-types (BLDT). The BLDT group appears to encompass less diversity than the NLDT, which reflects the larger geographic range of NLDTs, and suggests a more recent origin of domestication of the BLDTs. As well as being genetically distinct, hemp, NLDT and BLDT genetic groups each produce unique cannabinoid and terpenoid content profiles. This combined analysis of population genomic and trait variation informs our understanding of the potential uses of different genetic variants for medicine and agriculture, providing valuable insights and tools for a rapidly emerging, valuable legal industry.
Can the two Asian giants reach a political settlement?
Authors: Kapur Ashok 
Published: December 2015

Purpose– The purpose of this paper is to outline the history of the Sino-Indian conflict and to evaluate recent changes as reflected in the high level meetings between President Xi Jinping and Prime Minister Narendra Modi. It explores the evolving relationship in terms of three types of bargaining: elusive, tacit and convergent.Design/methodology/approach– By adopting a historical approach one gets a better sense of the evolving pattern of relations between China and India and the circumstances in which the evolution is occurring.Findings– China-India relations are similar to a journey where the progress is measured in terms of small steps rather than a final peace settlement. Relations have changed slowly towards a positive direction in economic relations, and there is a pattern of stability in border talks but the issue is complicated by the linkages between the Tibet question and border issues.Research limitations/implications– This topic requires considerable research because it is important for the future of Asian international relations and it is under-researched. Perhaps there could be an edited volume which brings together researchers from different backgrounds and expertise. The suggested work must be empirical but with a theoretical framework related to different types of bargaining cultures and experiences in Asia.Originality/value– As China and India evolve in their diplomatic practices and thinking, as Asian powers are readjusting their policies in the light of new circumstances, there are insights for policy analysts and practitioners in China and India among other Asian countries.