Horizontal Stripes Research Articles

Application of orthogonal fringe patterns in uniaxial microscopic 3D profilometry

This research presents a novel uniaxial microscopic 3D profilometry method with the application of orthogonal fringe patterns in a structured light system. Specifically, the projector alternately projects vertical and horizontal stripes, and subtraction of two adjacent shot images is applied to eliminate the influence of the background information. This method requires only one-tenth of our previous method in collection and data processing volume, but the accuracy can achieve almost the same as that method. We will describe the principle of this uniaxial microscopic 3D profilometry and demonstrate the accuracy of the proposed measurement framework by comparing it with the ten-step phase-shifting method and the Fourier transform method. It shows that approximately 5.22 µm root-mean-square (RMS) error with a depth range of 1100 µm can be achieved by the proposed approach.

Real Time Defect Identification of White Fabric in Textile Industry using Computer Vision

This study focuses on the defect identification of white fabric in the textile industry based on quality control standards. The standard manual process for examining fabric defects are labor and cost expensive. In this study, a high-quality camera will be used to capture the image of the fabric moving from the conveyor belt that will be processed to identify defects such as horizontal or vertical stripes, yarn missing, bunching up, and stains. Comparative analysis of the machine learning technique will be performed to find the best method. The method will be evaluated on a dataset captured through the local textile industry. At the production level, if some defect is found the machine will stop working unless that defect is resolved.

Body size illusion by vertical and horizontal stripe patterns of clothes

縦縞が横縞よりも横幅が長く知覚される錯視をヘルムホルツ錯視と呼ぶ。一方で，ファッション業界では，縦縞模様は横縞模様よりも横幅が細く，身長が高く見えるとされ，逆の錯視が主張されている。本研究1では 3D人体モデルを用いて，服装の縞模様による体型錯視効果を，縞の向き（縦，横），duty比（0.1，0.5），太さ（4水準）の要因を操作し，階段法のアルゴリズムに基づいて測定した。参加者は20名の大学生であった。標準刺激は日本人女性の 3D平均体型CGモデルが白と黒の縞模様のワンピースを着用した画像であった。比較刺激はグレーの全身タイツを着用したCGモデルであり，平均体型からスリーサイズが±10 cmの範囲で 2 cmずつ変化した11段階の刺激を用いた。参加者の課題は左右に並んで提示されたモデルのうち，より太って見える方を選ぶことであった。その結果，縦縞ではduty比0.5のほうが0.1より細く知覚された。duty比0.5の時のみ横縞より縦縞のほうが細く知覚された。しかも，縦縞でも横縞でも縞が細くなるほど体型が細く知覚されていた。さらに研究2では縦縞・横縞の服が身長の知覚に及ぼす錯視効果も検討した。

Darks and Stripes: Effects of Clothing on Weight Perception

In many societies, appearing slim is considered attractive. The fashion industry has been attempting to cater to this trend by designing outfits that can enhance the appearance of slimness. Two anecdotal rules, widespread in the world of fashion, are (1) choose dark clothes and (2) avoid horizontal stripes, in order to appear slim. Thus far, empirical evidence has been unable to conclusively determine the validity of these rules, and there is consequently much controversy regarding the impact of both color and patterns on the visual perception of weight. In this paper, we aim to close this gap by presenting the results from a series of large-scale crowdsourcing studies that investigate the above two claims. We gathered a dataset of around 1,000 images of people from the Web together with their ground-truth weight and height, as well as clothing attributes about colors and patterns. To elicit the effects of colors and patterns, we asked crowd workers to estimate the weight in each image. For the analysis, we controlled potential confounds by matching images in pairs where the two images differ with respect to color or pattern, but are similar with respect to other relevant aspects. We created image pairs in two ways: first, observationally, i.e., from two real images; and second, experimentally, by manipulating the color or pattern of clothing in a real image via photo editing. Based on our analysis, we conclude that (1) dark clothes indeed decrease perceived weight slightly but statistically significantly, and (2) horizontal stripes have no discernible effect compared to solid light-colored clothes. These results contribute to advancing the debate around the effect of specific clothing colors and patterns and thus provide empirical grounds for everyday fashion decisions. Moreover, our work gives an outlook on the vast opportunities of using crowd sourcing in the modern fashion industry.

Joint multi-scale discrimination and region segmentation for person re-ID

Abstract Most existing person re-identification methods are mainly based on human part partition with horizontal stripes or human body semantic segmentation. In this paper, we propose a method called MDRS (Multi-scale Discriminative network with Region Segmentation) to integrate multi-scale discriminative feature learning, horizontal stripe partition and semantic segmentation in a single framework, in which multi-scale horizontal stripe partition and usage of both global and local features make the framework be robust to human pose variation, occlusion and background clutter, and semantic segmentation boosts the performance of person identification via shared multi-scale feature extraction. MDRS is trained end-to-end with a multi-task learning strategy that considers three tasks simultaneously: person identification, triplet prediction and pixel-wise semantic segmentation. Comprehensive experiments confirm that our approach exceeds many methods and robustly achieves excellent performances on mainstream evaluation datasets including Market-1501, DukeMTMC-reid and CUHK03.

Malaysia Textile Craft Industry: Innovation Inspired by Bamboo for Batik Block Contemporary Design

Block Batik in batik industry has been practised in Malaysia since 1920s. It also known as “Batik Cop” or “Batik Terap”. The block for stamping or “Sarang Batik” normally made from steel with variety design on the surface of it. The beauty of the block batik pattern designs depend on the fineness and creativity of the motifs designed that engraved on the surface of the block by the expertise of the engraver. Therefore the objective of the study is to produce new design for block batik used from natural sources which is bamboo as a block to stamp the design for batik. The study emphasized on the uses of bamboo sticks cutted from bamboo tree sections as a block to create new geometric and spontaneous design for block batik design. Bamboo is one of the tropical resources in Malaysia. The light weight of the bamboo sticks alternatively can reduce the consequences towards the practitioners rather than using block made from steel which is more heavy than bamboo. The structure on the bamboo vascular cross sections scattered around the trunk create circular motif, dots and dotted lines. The uniqueness of the motif and pattern using bamboo as a block depends on the creativity in manipulating the structure of the bamboo with stamping techniques and the application of wax and the color techniques. A variety of designs such as overall repetition, vertical stripes and horizontal stripes as well as color overlays and tones highlight the creativity of the batik design. Such designs can be featured in the market especially for production of handicraft products, interior decoration and clothing design. Therefore, this study significantly gives an ideas and inspiration for batik entrepreneurs in producing block batik by using bamboo as new natural based batik design at a lower-cost.

Systematic reappraisal of the anti-equatorial fish genus Microcanthus Swainson (Teleostei: Microcanthidae), with redescription and resurrection of Microcanthus joyceae Whitley.

The taxonomy and classification of the microcanthid fish genus Microcanthus Swainson has been a subject of contention dating back to the 19th century. Its allopatric, disjunct anti-equatorial distribution across the Indo-West Pacific has resulted in the recognition of several nominal taxa, though these have been widely regarded as synonyms of Microcanthus strigatus (Cuvier). Following the results published in a companion study elsewhere by the authors, the taxonomy of Microcanthus and the validity of these nominal synonyms are herewith revised. Microcanthus strigatus is redescribed on the basis of 66 specimens from East Asia, Hawaii and Western Australia, and M. joyceae is resurrected and redescribed on the basis of 25 specimens from eastern Australia and the southwest Pacific. Microcanthus differs from other microcanthid genera in having the following combination of characters: dorsal-fin rays XI,15-17 (usually XI,16); anal-fin rays III,13-15 (usually III,14); pectoral-fin rays 15-17 (usually 16); scales ctenoid with ctenial bases present; lateral-line scales partially or heavily obscured by adjacent scales; and body pale in preservation with five horizontal dark stripes reaching the posterior edges of dorsal and anal fins, and base of caudal fin. The review is accompanied by a key to the genera of Microcanthidae.

An automated method for removal of striping artifacts in fluorescent whole-slide microscopy

BackgroundWhole slide scanners often acquire images of tissue sections that are larger than their field of view through tile or line-scanning. The subsequently stitched or aligned images can often suffer from imaging artifacts such as horizontal or vertical stripes. These stripes degrade the image quality in fluorescent biological imaging samples and can also limit the accuracy of any subsequent analyses such as cell segmentation. New methodWe propose a novel data-driven method of removing stripe artifacts in stitched biological images based on the location of the stripes, background modeling, and illumination correction. This method provides an automated way of removing the stripes of an individual image while preserving image details and quality for subsequent analyses. ResultsThe results were assessed using both qualitative and quantitative metrics and the algorithm has proven very effective in removing the stripe artifacts from hundreds of brain images. Comparison with existing methodsSeveral metrics were used to quantify the effectiveness of our proposed method compared to other published techniques. Images with simulated artifacts were created so that full-reference metrics could be applied to demonstrate the applicability of the algorithm for a wider variety of illumination profiles. ConclusionsWe describe a data analysis pipeline that allows for automatic removal of stripes caused by line-scanning. Our proposed method can be applied without the need for separate blank field of view images or use of image batches to model the background, so it is suitable for real-time parallel batch processing of large datasets.

Out-of-plane Response of an Innovative Masonry Infill with Sliding Joints from Shaking Table Tests

ABSTRACT Within the European FP7 Project “INSYSME”, the research unit of the University of Pavia has developed a seismic-resistant masonry infill system with original details, which subdivides the masonry panel into horizontal stripes through the insertion of “sliding joints” and deformable joints at the infill–frame interface. The out-of-plane stability is governed by the flexural/arching resistance of the masonry stripes and adequate supports at the RC columns. An extensive experimental campaign has been performed. In this paper, the results of the out-of-plane dynamic tests on shaking-table conducted on the specimens with and without opening are discussed. These types of tests, never applied before on innovative masonry infill typologies, have involved a very demanding testing protocol, constituted of artificial input motions at increasing intensity. To interpret the test results and provide first indications for safety checks, simplified numerical and analytical simulations of the tests have been conducted. According to the out-of-plane experimental performance of this innovative infill system and to the satisfactory in-plane response, the solution appears to be very promising for real applications.

Galanin Signaling in the Brain Regulates Color Pattern Formation in Zebrafish.

SummaryColor patterns are prominent features of many animals and are of high evolutionary relevance. In basal vertebrates, color patterns are composed of specialized pigment cells that arrange in multilayered mosaics in the skin. Zebrafish (Danio rerio), the preeminent model system for vertebrate color pattern formation, allows genetic screens as powerful approaches to identify novel functions in a complex biological system. Adult zebrafish display a series of blue and golden horizontal stripes, composed of black melanophores, silvery or blue iridophores, and yellow xanthophores. This stereotyped pattern is generated by self-organization involving direct cell contacts between all three types of pigment cells mediated by integral membrane proteins [1, 2, 3, 4, 5]. Here, we show that neuropeptide signaling impairs the striped pattern in a global manner. Mutations in the genes coding either for galanin receptor 1A (npm/galr1A) or for its ligand galanin (galn) result in fewer stripes, a pale appearance, and the mixing of cell types, thus resembling mutants with thyroid hypertrophy [6]. Zebrafish chimeras obtained by transplantations of npm/galr1A mutant blastula cells indicate that mutant pigment cells of all three types can contribute to a normal striped pattern in the appropriate host. However, loss of galr1A expression in a specific region of the brain is sufficient to cause the mutant phenotype in an otherwise wild-type fish. Increased thyroid hormone levels in mutant fish suggest that galanin signaling through Galr1A in the pituitary is an upstream regulator of the thyroid hormone pathway, which in turn promotes precise interactions of pigment cells during color pattern formation.

A new species of Cyphocharax (Characiformes: Curimatidae) with a horizontal color pattern from the rio Tapajós drainage, Amazon basin, Brazil

ABSTRACT A new species of Cyphocharax is described from the rio Mentaí, a tributary of rio Arapiuns, lower rio Tapajós basin, Pará state, Brazil. The new species can be distinguished from its congeners by the combination of a rounded dark blotch at the caudal peduncle and a pattern of horizontal stripes formed by series of conspicuous dark spots situated over the center of the scales on the lateral and dorsolateral surfaces of the body. The new Cyphocharax is compared with similar congeners as C. helleri, C. multilineatus, and C. pantostictos. Comments on the distribution of C. multilineatus are provided.

The last one: A new species of Osteocephalus (Anura: Hylidae) from Colombia, with comments on the morphological and behavioral diversity within the genus

A new species of Osteocephalus (Anura: Hylidae) from Colombia, with comments on the morphological and behavioral diversity within the genus. A striking, undescribed species of Osteocephalus from the Amazonian slopes of the Andes in Departamento de Putumayo in southern Colombia is a member of the Osteocephalus buckleyi Group. Aside from minor morphological characters, the new species differs from all other members of the group by having a golden yellow iris with a median horizontal black stripe. The diversity in morphological and reproductive behavior reveals various features that are phylogenetically signifcant, but several species remain to be described.

Satellite-ground integrated destriping network: A new perspective for EO-1 Hyperion and Chinese hyperspectral satellite datasets

From the EO-1 Hyperion imaging spectrometer to the newly launched Chinese satellite hyperspectral imagers, stripe noise is a ubiquitous phenomenon that seriously degrades the data quality and usability. Although previous efforts have achieved inspiring results, hyperspectral image (HSI) destriping remains a challenging task, as the stripe degradations are sometimes more complicated than the predefined assumptions, i.e., the preselected reference, filter, or handcrafted priors. With the rapid advances in deep learning technologies, convolutional neural networks (CNNs) provide a new potential to learn essential priors in an automatic manner. However, the training of CNNs is highly reliant on a large high-quality standard dataset, which is difficult to acquire for hyperspectral spaceborne sensors. In this paper, an innovative approach termed the satellite-ground integrated destriping network (SGIDN) is proposed for HSIs. Rather than using self-training, a satellite-ground integrated strategy is proposed, for the first time, to mitigate the data dependency, so that a large set of striped-clean pairs is generated from the ground-based HSIs. Considering the varied stripes among different bands, a unique CNN architecture design, including the combination of 3D convolution and 2D convolution, residual learning, and supplementary gradient channels, is integrated to capture the intrinsic spectral-spatial features in the HSIs and the unidirectional property of stripe noise. Compared with the traditional methods, SGIDN can be flexibly extended to specific HSI destriping tasks, e.g., coexisting horizontal and vertical stripes, and generalizes well to different hyperspectral satellite sensors. Given the same study area (Shanghai, China), three HSIs acquired by the EO-1 Hyperion imaging spectrometer, the Chinese HJ-1A HSI sensor, and the wide-range hyperspectral imager onboard the Chinese SPARK spectral micro-nano satellite are adopted to assess the proposed SGIDN model. Both simulated and real-data experiments confirm that SGIDN can consistently outperform the benchmark methods, with a higher degree of efficiency. Moreover, the land-cover mapping results further demonstrate the necessity of destriping and the suitability of the destriped results for use in further applications.

C13–NMR study of charge fluctuations in α–(BEDT–TTF)MX salts (M=alkali metal; X=S, Se)

Optical studies of the density wave (DW) salt of $\ensuremath{\alpha}\text{\ensuremath{-}}{(\mathrm{BEDT}\text{\ensuremath{-}}\mathrm{TTF})}_{2}{\mathrm{KHg}(\mathrm{SCN})}_{4}$ revealed a pseudogap due to a charge fluctuation below ${T}^{*}\ensuremath{\simeq}$ 200 K. Moreover, $^{13}\mathrm{C}$-NMR studies of the DW salt of $\ensuremath{\alpha}\text{\ensuremath{-}}{(\mathrm{BEDT}\text{\ensuremath{-}}\mathrm{TTF})}_{2}{\mathrm{RbHg}(\mathrm{SCN})}_{4}$ and of the superconductivity (SC) salt of $\ensuremath{\alpha}\text{\ensuremath{-}}{(\mathrm{BEDT}\text{\ensuremath{-}}\mathrm{TTF})}_{2}{\mathrm{NH}}_{4}\mathrm{Hg}{(\mathrm{SCN})}_{4}$ suggested that the NMR line width of the A site increased and the charge disproportionation in the A column developed below ${T}^{*}$. These phenomena may be due to the development of a horizontal stripe modulation of the local charge density. However, whether the horizontal stripe modulation develops or not and the relationships among ${T}^{*}$ anomalies, the pseudogap, and line broadening, were unclear. In this study, $^{13}\mathrm{C}$-NMR measurements were obtained of the metallic salt of $\ensuremath{\alpha}\text{\ensuremath{-}}{(\mathrm{BEDT}\text{\ensuremath{-}}\mathrm{TTF})}_{2}{\mathrm{TlHg}(\mathrm{SeCN})}_{4}$, and its electronic structure was compared with those of the DW and SC salts. The NMR line width of the A site and ${\ensuremath{\chi}}_{\mathrm{B}}/{\ensuremath{\chi}}_{\mathrm{C}}$ in Rb(SCN) and $\mathrm{NH}{}_{4}$(SCN) increased and deviated from that in Tl(SeCN) below ${T}^{*}$, suggesting the development of the instability of horizontal stripe modulation in Rb(SCN) and $\mathrm{NH}{}_{4}$(SCN) and that ${T}^{*}$ anomalies could be due to the instability.

Evolutionary Dynamics of Structural Variation at a Key Locus for Color Pattern Diversification in Cichlid Fishes.

Color patterns in African cichlid fishes vary spectacularly. Although phylogenetic analysis showed already 30 years ago that many color patterns evolved repeatedly in these adaptive radiations, only recently have we begun to understand the genomic basis of color variation. Horizontal stripe patterns evolved and were lost several times independently across the adaptive radiations of Lake Victoria, Malawi, and Tanganyika and regulatory evolution of agouti-related peptide 2 (agrp2/asip2b) has been linked to this phenotypically labile trait. Here, we asked whether the agrp2 locus exhibits particular characteristics that facilitate divergence in color patterns. Based on comparative genomic analyses, we discovered several recent duplications, insertions, and deletions. Interestingly, one of these events resulted in a tandem duplication of the last exon of agrp2. The duplication likely precedes the East African radiations that started 8–12 Ma, is not fixed within any of the radiations, and is found to vary even within some species. Moreover, we also observed variation in copy number (two to five copies) and secondary loss of the duplication, illustrating a surprising dynamic at this locus that possibly promoted functional divergence of agrp2. Our work suggests that such instances of exon duplications are a neglected mechanism potentially involved in the repeated evolution and diversification that deserves more attention.

Результаты использования альтернирующего предъявления различных стереостимулов для исследования способности к стереовосприятию у детей с послеоперационной остаточной микродевиацией

Purpose. To study abilities to stereo-perception in children with postoperative residual micro-deviation via alternating presentation of different stereo stimuli. Material and methods. The study included 30 children aged 8 to 16 years (average 12.5 years) with operated strabismus who have postoperative residual micro-deviation (mean 6.8±0.4 pr.D) at the time of the observation. Residual esotropia was observed in 21 children (5 of them had also a vertical micro-deviation), exotropia – 9 children. Along with the usual ophthalmic examination and evaluation of stereovision by means of classical Lang-test and Fly-test we used our own stereo-tests developed on the basis of stereo images created by J. Ninio. Our stereo-tests included stimuli: 1) with a central location of vertical or horizontal stripes with a successful fusion and an ability to stereo perception of tilt relative to the horizontal axis (vertical strip) or turn around the vertical axis (horizontal strip); 2) with a peripheral location of vertical or horizontal stripes creating respectively the effect of tilt or reversal turn; 3) randomly-point stereo-grams, creating the impression of a successful fusion of vertical or horizont al cylinder. The subject observed the images shown on the monitor screen from a distance of 50 cm from the eyes through the red-blue light filters in conditions of full prismatic compensation of the angle of strabismus and optimal spectacle or contact correction of ametropia. The stimuli were presented both in the static version and in the modes of alternation via a computer pr ogram developed by M. V. Zhmurov. Three modes of alternative presentation of stimuli were used: 1) the mode with a consecutive monocular presentation of visual stimuli corresponding to the right and left eyes 2) the mode with the presence of an empty interval between monocular phases; 3) the mode with the presence of a binocular phase between monocular phases. Results. In all patients, the results of the study of stereovision with Lang-test, Fly-test and static version of our stereo-tests used in this work were negative. In eight children of the general group, the stereo effect appears only with stereo-images with a peripheral arrangement of vertical or horizontal stripes in all three modes of the alternating presentation. In 22 children, the stereo effect appears with stimuli both with peripheral and with the central location of the stripes in all three modes of their alternating presentation. The volume effect with random-dot stereo-stimuli occurred in only nine children, with a stable bifoveal fusion, and only in the mode of alternating presentation with an empty interval between monocular phases. Thus, in this mode of alternating presentation it was possible to perceive not only linear, but also random-dot stereo-images. Comparing the maximum durations of monocular phases for different images in this mode, a significant difference was found between the mean values for stimuli with peripheral vertical stripes (57±2.3 ms) and with central vertical stripes (43.2±2.6 ms; p<0.001), as well as between the mean values for stimuli with peripheral horizontal stripes (56±2.1 ms) and central horizontal stripes (43.6±3.4 ms; p<0.002). The maximum duration of monocular phases for random-dot stereo-images producing the effect of a vertical cylinder (32.2±5.8 ms) and a horizontal cylinder (31.1±6.7 ms) was significantly lower than the maximum duration for stimuli with peripheral vertical and horizontal stripes (p<0.001). The same regularities were observed for the maximum dur ation of the empty i nterval. Conclusion. The stereo-perception is possible in children with residual postoperative micro-deviation. At the same time, the most effective of the images we used are stimuli with a peripheral arrangement of elements that create a stereo effect in condition of a successful fusion. The mode of alternating presentation of stimuli with the presence of an empty interval between monocular phases creates more favorable conditions for the appearance of a stereo effect in comparison with the mode of alternating presentation of stimuli with the presence of a binocular phase between monocular phases and in comparison with the mode of alternating monocular phases. Stereovision with random-dot stereograms causes serious difficulties in most children with postoperative microdeviation, however, it is possible in some cases in the mode of alternating presentation of stimuli with the presence of an empty i nterval between monocular phases.

Zebrafish Pigment Pattern Formation: Insights into the Development and Evolution of Adult Form.

Vertebrate pigment patterns are diverse and fascinating adult traits that allow animals to recognize conspecifics, attract mates, and avoid predators. Pigment patterns in fish are among the most amenable traits for studying the cellular basis of adult form, as the cells that produce diverse patterns are readily visible in the skin during development. The genetic basis of pigment pattern development has been most studied in the zebrafish, Danio rerio. Zebrafish adults have alternating dark and light horizontal stripes, resulting from the precise arrangement of three main classes of pigment cells: black melanophores, yellow xanthophores, and iridescent iridophores. The coordination of adult pigment cell lineage specification and differentiation with specific cellular interactions and morphogenetic behaviors is necessary for stripe development. Besides providing a nice example of pattern formation responsible for an adult trait of zebrafish, stripe-forming mechanisms also provide a conceptual framework for posing testable hypotheses about pattern diversification more broadly. Here, we summarize what is known about lineages and molecular interactions required for pattern formation in zebrafish, we review some of what is known about pattern diversification in Danio, and we speculate on how patterns in more distant teleosts may have evolved to produce a stunningly diverse array of patterns in nature.

Bar, stripe and spot development in sand-dwelling cichlids from Lake Malawi

BackgroundMelanic patterns such as horizontal stripes, vertical bars and spots are common among teleost fishes and often serve roles in camouflage or mimicry. Extensive research in the zebrafish model has shown that the development of horizontal stripes depends on complex cellular interactions between melanophores, xanthophores and iridophores. Little is known about the development of horizontal stripes in other teleosts, and even less is known about bar or spot development. Here, we compare chromatophore composition and development of stripes, bars and spots in two cichlid species of sand-dwellers from Lake Malawi—Copadichromis azureus and Dimidiochromis compressiceps.Results(1) In D. compressiceps, stripes are made of dense melanophores underlaid by xanthophores and overlaid by iridophores. Melanophores and xanthophores are either loose or absent in interstripes, and iridophores are dense. In C. azureus, spots and bars are composed of a chromatophore arrangement similar to that of stripes but are separated by interbars where density of melanophores and xanthophores is only slightly lower than in stripes and iridophore density appears slightly greater. (2) Stripe, bar and spot chromatophores appear in the skin at metamorphosis. Stripe melanophores directly differentiate along horizontal myosepta into the adult pattern. In contrast, bar number and position are dynamic throughout development. As body length increases, new bars appear between old ones or by splitting of old ones through new melanophore appearance, not migration. Xanthophore and iridophore distributions follow melanophore patterns. (3) Metamorphic pigmentation arises in cichlids in a fashion similar to that described in zebrafish: melanophore progenitors derived from the medial route of neural crest migration migrate from the vicinity of the neural tube to the skin during metamorphosis.ConclusionThe three pigment cell types forming stripes, bars and spots arise in the skin at metamorphosis. Stripes develop by differentiation of melanophores along horizontal myosepta, while bars do not develop along patent anatomical boundaries and increase in number in relation with body size. We propose that metamorphic melanophore differentiation and migratory arrest upon arrival to the skin lead to stripe formation, while bar formation must be supported by extensive migration of undifferentiated melanophores in the skin.

Attenuation of stripe artifacts in optical coherence tomography images through wavelet-FFT filtering.

The use of polarization-maintaining (PM) fibers for polarization-sensitive optical coherence tomography (PS-OCT) can result in numerous image artifacts which degrade the reliability of birefringence measurements. Similar artifacts can also arise in conventional OCT, due to stray reflections from optical surfaces, a problem which is increasing in tandem with the steady rise in source coherence lengths. Here, a recently presented wavelet-FFT filter[Opt. Express 17(10), 8567 (2009).19434191] is combined with surface flattening displacement fields in order to suppress ghost artifacts following either a duplicate or inverse profile to that of the sample surface. In addition, horizontal coherence stripes originating from Fresnel reflections of optical components are suppressed in order to facilitate accurate surface detection. The result is an improved visualization of the phase-retardance profile within tissue, which may improve the reliability of curve-fitting methods for localized birefringence estimation. While the results are presented with a focus towards PS-OCT, the filtering method can also be applied to the removal of stray reflection artifacts in conventional OCT images.

Real-space observation of charge ordering in epitaxial La2\u2212xSrxCuO4 films

The cuprate superconductors exhibit ubiquitous instabilities toward charge-ordered states. These unusual electronic states break the spatial symmetries of the host crystal, and have been widely appreciated as essential ingredients for constructing a theory for high-temperature superconductivity in cuprates. Here, we report real-space imaging of the doping-dependent charge orders in the epitaxial thin films of a canonical cuprate compound La2–xSrxCuO4 using scanning tunneling microscopy. As the films are moderately doped, we observe a crossover from incommensurate to commensurate (4a0, where a0 is the Cu–O–Cu distance) stripes. Furthermore, at lower and higher doping levels, the charge orders occur in the form of distorted Wigner crystal and grid phase of crossed vertical and horizontal stripes. We discuss how the charge orders are stabilized, and their interplay with superconductivity.