Stripe Pattern Research Articles

Carpets with visual cues can improve gait in Parkinson’s disease patients: may be independent of executive function

BackgroundGait impairment is common in Parkinson’s disease (PD) patients, which greatly reduces their quality of life. Executive dysfunction is associated with gait impairment. Compensatory strategies, including visual cues, have been shown to be effective in improving PD gait. In this study, we aimed to understand whether carpets with visual cues could improve PD gait, and how the improvement varies across patients with different executive function state.MethodsWe designed carpets with chessboard and stripe cues. A total of 65 Chinese PD patients were recruited. Movement Disorder Society Unified Parkinson’s Disease Rating Scale, L-dopa equivalent daily dosage, Hoehn & Yahr stage, Frontal Assessment Battery, Mini Mental State Examination Scale, Hamilton Anxiety Scale, and Hamilton Depression Scale were evaluated. Gait parameters including stride length, gait speed and fall risk were recorded by a wearable electronic device.ResultsThe stride length and gait speed were significantly improved and the fall risk was significantly mitigated when PD patients walked on carpets with chessboard and stripe patterns. Further analysis showed the amelioration of gait parameters was independent of executive dysfunction.ConclusionsOur study demonstrates that carpets with visual cues can improve the gait of PD patients even in those with mild executive dysfunction.

Sequentially coupling LBNL-method and Modelica to model and operate adaptive facades with inhomogeneous printing patterns

In this work, two U- and g-value Modelica models of a three-layer membrane construction with inhomogeneous stripe pattern were set up. Thus, a simple ISO 52022 model is compared with a detailed model with Modelica integration of Klems-Matrices by LBNL method calculation. For the U-value, both models equally predict the heat transmission. For the g-value, the detailed model shows an strong angular behavior depending on the stripe pattern, the layer distances. Compared to a reference glazing, the application of an adaptive operating strategy results in a reduction of the total energy consumption by up to 27%. Depending on the operation strategy the heating energy increases between 33-100% and cooling energy decreases by 50-80%. This is mainly due to the lower g-value with the detailed model. The actuation energy required for this can be neglected. The resulting reductions in heating and cooling energy exceed the actuation energy by several orders of magnitude.

Description of life cycle and immature stages of Yphthimoides celmis (Godart, [1824]) (Lepidoptera: Nymphalidae: Satyrinae): a contribution to the taxonomic status of the genus.

This article describes the immature stages of the satyrid butterfly Yphthimoides celmis (Godart) for the first time. Morphology, head and body chaetotaxy, and coloration patterns are compared with those of other Yphthimoides species. Larvae behavioral aspects and oviposition behavior are also documented here. Overwintering larvae are observed for the first time for this genus. The larval stage has four or five instars in non-overwintering while six in overwintering larvae. The average duration of the life cycle is around 82 days for non-overwintering, while it is 227 days for overwintering larvae under laboratory conditions. The increase in instar stages and the development time duration of immature stages in overwintering larvae may be due to climatic conditions in the study area and also a strategy to survive the cold season. Eggs have irregular pentagonal and hexagonal cells. First instar larvae have a dark head capsule and a pattern of reddish stripes along their body, with clubbed body setae. Pupae are short and smooth with a non-uniform brown color, presenting a lighter clypeus and a darker ventral portion in the cremaster. We consider that the morphological information of immature stages can improve further phylogenetic studies.

Development shapes the evolutionary diversification of rodent stripe patterns.

Vertebrate groups have evolved strikingly diverse color patterns. However, it remains unknown to what extent the diversification of such patterns has been shaped by the proximate, developmental mechanisms that regulate their formation. While these developmental mechanisms have long been inaccessible empirically, here we take advantage of recent insights into rodent pattern formation to investigate the role of development in shaping pattern diversification across rodents. Based on a broad survey of museum specimens, we first establish that various rodents have independently evolved diverse patterns consisting of longitudinal stripes, varying across species in number, color, and relative positioning. We then interrogate this diversity using a simple model that incorporates recent molecular and developmental insights into stripe formation in African striped mice. Our results suggest that, on the one hand, development has facilitated pattern diversification: The diversity of patterns seen across species can be generated by a single developmental process, and small changes in this process suffice to recapitulate observed evolutionary changes in pattern organization. On the other hand, development has constrained diversification: Constraints on stripe positioning limit the scope of evolvable patterns, and although pattern organization appears at first glance phylogenetically unconstrained, development turns out to impose a cryptic constraint. Altogether, this work reveals that pattern diversification in rodents can in part be explained by the underlying development and illustrates how pattern formation models can be leveraged to interpret pattern evolution.

Electronic stripe patterns near the fermi level of tetragonal Fe(Se,S)

FeSe1−xSx remains one of the most enigmatic systems of Fe-based superconductors. While much is known about the orthorhombic parent compound, FeSe, the tetragonal samples, FeSe1−xSx with x > 0.17, remain relatively unexplored. Here, we provide an in-depth investigation of the electronic states of tetragonal FeSe0.81S0.19, using scanning tunneling microscopy and spectroscopy (STM/S) measurements, supported by angle-resolved photoemission spectroscopy (ARPES) and theoretical modeling. We analyze modulations of the local density of states (LDOS) near and away from Fe vacancy defects separately and identify quasiparticle interference (QPI) signals originating from multiple regions of the Brillouin zone, including the bands at the zone corners. We also observe that QPI signals coexist with a much stronger LDOS modulation for states near the Fermi level whose period is independent of energy. Our measurements further reveal that this strong pattern appears in the STS measurements as short range stripe patterns that are locally two-fold symmetric. Since these stripe patterns coexist with four-fold symmetric QPI around Fe-vacancies, the origin of their local two-fold symmetry must be distinct from that of nematic states in orthorhombic samples. We explore several aspects related to the stripes, such as the role of S and Fe-vacancy defects, and whether they can be explained by QPI. We consider the possibility that the observed stripe patterns may represent incipient charge order correlations, similar to those observed in the cuprates.

Fabrication of Flexible and Transparent Metal Mesh Electrodes Using Surface Energy-Directed Assembly Process for Touch Screen Panels and Heaters.

Transparent conductive electrodes (TCEs) are indispensable components of various optoelectronic devices such as displays, touch screen panels, solar cells, and smart windows. To date, the fabrication processes for metal mesh-based TCEs are either costly or having limited resolution and throughput. Here, a two-step surface energy-directed assembly (SEDA) process to efficiently fabricate high resolution silver meshes is introduced. The two-step SEDA process turns from assembly on a functionalized substrate with hydrophilic mesh patterns into assembly on a functionalized substrate with stripe patterns. During the SEDA process, a three-phase contact line pins on the hydrophilic pattern regions while recedes on the hydrophobic non-pattern regions, ensuring that the assembly process can be achieved with excellent selectivity. The necessity of using the two-step SEDA process rather than a one-step SEDA process is demonstrated by both experimental results and theoretical analysis. Utilizing the two-step SEDA process, silver meshes with a line width down to 2µm are assembled on both rigid and flexible substrates. The thickness of the silver meshes can be tuned by varying the withdraw speed and the assembly times. The assembled silver meshes exhibit excellent optoelectronic properties (sheet resistance of 1.79Ω/□, optical transmittance of ≈92%, and a FoM value of 2465) as well as excellent mechanical stability. The applications of the assembled silver meshes in touch screen panels and thermal heaters are demonstrated, implying the potential of using the two-step SEDA process for the fabrication of TCEs for optoelectronic applications.

Global stability and Turing instability deduced by cross-diffusion in a delayed diffusive cooperative species model

In this paper, we investigate the dynamical behavior of a delayed diffusive cooperative species model with cross-diffusion. Firstly, in the case of self-diffusion, we study the persistence properties and global stability of positive equilibrium for this model by constructing Lyapunov function. The obtained results reveal that the delay has no effect on the stability of positive equilibrium for this model. However, cross-diffusion can affect the stability of positive equilibrium of this model. Then, we continue to discuss Turing bifurcation on one-dimensional space and Turing pattern on two-dimensional space, which are deduced by cross-diffusion. For Turing bifurcation, choosing some cross-diffusion rate as bifurcation parameter, this model undergoes Turing bifurcation nearby the positive equilibrium as cross-diffusion rate is across the Turing bifurcation curve, and bifurcates the stable spatially inhomogeneous steady state solutions. For Turing pattern, we find out the Turing region under some conditions successfully. Selecting the different values of two cross-diffusion rates in the Turing region respectively, we carry out some numerical simulations and obtain spots pattern, spots-strip pattern and strip pattern.

A multifunctional Wnt regulator underlies the evolution of rodent stripe patterns.

Animal pigment patterns are excellent models to elucidate mechanisms of biological organization. Although theoretical simulations, such as Turing reaction-diffusion systems, recapitulate many animal patterns, they are insufficient to account for those showing a high degree of spatial organization and reproducibility. Here, we study the coat of the African striped mouse (Rhabdomys pumilio) to uncover how periodic stripes form. Combining transcriptomics, mathematical modelling and mouse transgenics, we show that the Wnt modulator Sfrp2 regulates the distribution of hair follicles and establishes an embryonic prepattern that foreshadows pigment stripes. Moreover, by developing in vivo gene editing in striped mice, we find that Sfrp2 knockout is sufficient to alter the stripe pattern. Strikingly, mutants exhibited changes in pigmentation, revealing that Sfrp2 also regulates hair colour. Lastly, through evolutionary analyses, we find that striped mice have evolved lineage-specific changes in regulatory elements surrounding Sfrp2, many of which may be implicated in modulating the expression of this gene. Altogether, our results show that a single factor controls coat pattern formation by acting both as an orienting signalling mechanism and a modulator of pigmentation. More broadly, our work provides insights into how spatial patterns are established in developing embryos and the mechanisms by which phenotypic novelty originates.

Effect of post-heat treatment on the microstructure, mechanical, and corrosion properties of laser powder bed fused Al–Zn–Mg–Cu–Si–Zr–Er alloys

Three different post-heat treatments, including direct aging (DA), solution heat treatment + precipitate hardening (T6), and retrogression and re-ageing (RRA), were carried out on a Si–Zr–Er modified Al–Zn–Mg–Cu alloy, which is manufactured by laser powder bed fusion (LPBF). The results show that direct aging maintains the cellular structure of the as-printed (AP) alloy, while T6 and RRA promoted the damage and decomposition of the cellular structure. The size of the primary Al3(Er,Zr) phase increased after heat treatment, and secondary Al3(Er,Zr) phases were uniformly distributed in the matrix with a size of 5–20 nm. The Mg2Si phase in the DA alloy was a long strip pattern, but uniformly distributed in the T6 and RRA alloy. The ultimate tensile strength of the AP, DA, T6, and RRA alloys reached 468, 474, 389, and 354 MPa, respectively. The size, shape, and distribution of the Al3(Er,Zr) and Mg2Si phases have a significant impact on their corrosion resistance, with the latter having a stronger effect. To sum up, the strength of the DA alloy is increased, but its corrosion performance is decreased with heat treatment. On the other hand, the strength of the T6 and RRA alloys is somewhat sacrificed, but their plasticity and corrosion resistance are significantly enhanced.

Pre-existing visual preference for white dot patterns in estrildid finches: a comparative study of a multi-species experiment.

The diverse characteristics of animal signal designs can be explained by the sensory bias hypothesis, which suggests that natural selection shapes sensory bias and preferences associated with signal design. Traditionally, this hypothesis has focused on female sensory biases and male sexual traits. However, considering shared sensory systems between males and females in non-sexual contexts, existing sensory bias possibly contributes to the evolution of shared social and sexual traits. Our previous studies on the family Estrildidae supported this idea. An evolutionary relationship probably existed between diet and white dot plumage, and a species of estrildid finches showed a visual preference for white dot patterns. To investigate this further, we examined hunger-related visual preferences using phylogenetic comparative methods and behavioural experiments. Specifically, we compared the gazing responses of 12 species of estrildids to monochromatic printed white dot and stripe patterns, considering their phylogenetic relationships. The results support our idea that the common estrildid ancestor had a hunger-related visual preference for white dot patterns. Subject species generally preferred white dots to stripes. Furthermore, males and females showed a similar preference towards dots. Our findings provide insights into the role of sensory bias in the evolution of mutual ornamentation.

Stripes polymorphism and water-like anomaly in hard core-soft corona dumbbells

In this paper, we investigate the phase diagram of a dumbbell model composed of two hard-core soft-corona beads through NpT simulations. We chose this particular system due to its ability to exhibit a diverse range of stripe patterns. By analyzing the thermodynamic and structural changes along compression isotherms, we explore the transition between these distinct patterns. In addition to the stripe and Low-Density-Triangular solid phases obtained, we observed a Nematic Anisotropic phase characterized by a polymer-like pattern at high temperatures and intermediate pressures. Furthermore, we demonstrate the significant role played by the new characteristic length scale, which arises from the anisotropic geometry of the dumbbell structure, in the transition between the stripe patterns. Notably, not only do the structural properties exhibit intriguing behavior, but the diffusion and density in the nematic fluid phase also display a water-like anomalous increase under compression. These findings can be valuable in guiding the design of materials based on nanoparticles, with the aim of achieving specific mesopatterns.

Description of a common stauromedusa on the Pacific Coast of the United States and Canada, Haliclystus sanjuanensis new species (Cnidaria: Staurozoa).

Haliclystus "sanjuanensis" nomen nudum is the most common staurozoan on the west coast of the United States and Canada. This species was described in the M.S. Thesis by Gellermann (1926) and although that name has been in use nearly continuously since that time, no published description exists. Furthermore, the most popular operative name for this species has varied between several related species names over time, resulting in confusion. Herein, we provide a detailed description and synonymy of Haliclystus sanjuanensis n. sp., whose distribution is verified from Unalaska Island in the Aleutians (53.4° N, 166.8° W) in the northwest, to Santa Barbara County, California, just north of Point Conception (34.5° N, 120.5° W), in the south. Haliclystus sanjuanensis n. sp. is compared with the twelve other described species of Haliclystus and illustrations of both macroscopic and microscopic anatomy are provided. Haliclystus sanjuanensis n. sp. is unique among species of Haliclystus in the arrangement of the bright-white nematocyst spots in its calyx and the pattern of dark stripes running the length of the stalk and up the outside of the calyx.

Potential of carbon sequestration enhancement through intensive silvicultural techniques using Shorea leprosula plantation in Central Kalimantan, Indonesia

Abstract. Iskandar M, Siregar IZ, Krisnawati H. 2023. Potential of carbon sequestration enhancement through intensive silvicultural techniques using Shorea leprosula plantation in Central Kalimantan, Indonesia. Biodiversitas 24: 4699-4713. Various sectors are involved in achieving Indonesia’s Enhanced Nationally Determined Contribution (NDC), including Forestry and Other Land Uses (FOLU) sector. Sustainable Forest Management (SFM) implementation by forest concessionaires (PBPHs) enormously contributes to land-based mitigation activities, primarily at the local level. One of the SFM activities is forest enrichment with Intensive Silvicultural (SILIN) technique using Shorea leprosula Miq. to enhance carbon stock and sequestration. This study was conducted in PT Sarmiento Parakantja Timber (PT Sarpatim) in Central Kalimantan (Indonesia) and used the measurement data from 32 purposive sampling plots. Each plot was 40m × 40m in size, constructed under three different SILIN patterns (conventional strip, effective strip, and gap) as well as natural forest stands. This study found that SILIN gap pattern had higher carbon stock and sequestration potential, compared to the natural forest (reference) stands, and reached a net sink condition after 30 years. For the stands of SILIN conventional and effective strip patterns, the carbon stocks were lower than the reference stand, even when the vegetation aged 30 years. PBPHs applying SILIN technique as part of the SFM and the mitigation actions demonstrate an enhanced carbon stock and sequestration. This effort supports Indonesia’s Enhanced NDC target and FOLU Net Sink 2030.

Predation Risk Drives Aposematic Signal Conformity.

Contrary to expectations regarding efficient predator education mediated by lack of ambiguity and enhanced prey recognition, aposematic signals often show considerable intraspecific variability. For example, some striped skunks (Mephitis mephitis) are almost entirely white, others have black-and-white stripes of equivalent thicknesses, yet others are mostly black. We tested the ecological correlates of this variation in patterning using 749 museum skins collected across North America. Skunks had longer white-black borders and more bilaterally symmetrical stripes in areas with a greater number of potential predator species, and this effect was more marked for mammalian than avian predators, the latter of which may be less deterred by noxious defenses. Skunks from locations with greater predator diversity were less variable in extent of whiteness on their dorsa and less variable in the length of their white-black borders, suggesting strong selection from predators leads to greater conformity in stripe patterns, even at the same location, but weak selection from predators leads to relaxed selection on pattern conformity. Skunks exhibited greater areas of black pelage in areas of greater humidity conforming to Gloger's rule. Our results indicate that relaxed predation pressure is key to warning signal variation in this iconic species, whereas stronger pressure leads to signal conformity and stronger signals.

Mini droplet, mega droplet and stripe formation in a dipolar condensate

We demonstrate mini droplet, mega droplet and stripe formation in a dipolar 164Dy condensate, using an improved mean-field model including a Lee–Huang–Yang-type interaction, employing a quasi-two-dimensional (quasi-2D) trap in a way distinct from that in the pioneering experiment, M. A. Norcia et. al., Nature 596, 357 (2021), where the polarization z direction was taken to be perpendicular to the quasi-2D x–y plane. In the present study we take the polarization z direction in the quasi-2D x−z plane. Employing the same trapping frequencies as in the experiment, and interchanging the frequencies along the y and z directions, we find the formation of mini droplets for number of atoms N as small as N=1000. With the increase of number of atoms, a spatially-periodic supersolid-like one-dimensional array of mega droplets containing 50000 to 200000 atoms is formed along the x direction in the x–y plane. These mega droplets are elongated along the polarization z direction, consequently, the spatially periodic arrangement of droplets appears as a stripe pattern in the x−z plane. To establish the supersolidity of the droplets we demonstrate continued dipole-mode and scissors-mode oscillations of the droplet-lattice pattern. The main findings of the present study can be tested experimentally with the present know-how.

A study of a spatiotemporal delayed predator–prey model with prey harvesting: Constant and periodic diffusion

This study investigates the emergence of Turing patterns in a predator–prey system with time delay at variable carrying capacity and prey harvesting in the presence of cross-diffusion. The impact of time delay and periodic diffusion on the stability of the equilibrium point and corresponding Turing pattern is primarily explored. Theoretical implications of Turing instability conditions caused by time delay and periodic diffusion are examined, followed by numerical simulations for ecologically meaningful control parameter values. The effects of carrying capacity specification parameters, time delay, and prey-harvesting effort on the emerging pattern are reported. Cross-diffusion results in a wide range of spatiotemporal pattern creation, including spot and stripe patterns, as well as both coexist under the zero flux border condition in unharvested or harvested dynamics. Furthermore, an intertwined pattern emerges under certain parameters, including time delay. The final comparison highlights the significant roles played by periodic diffusion, time delay, and harvesting effort in the evolution of the Turing pattern.

Kcnj13 regulates pigment cell shapes in zebrafish and has diverged by cis-regulatory evolution between Danio species.

Teleost fish of the genus Danio are excellent models to study the genetic and cellular bases of pigment pattern variation in vertebrates. The two sister species Danio rerio and Danio aesculapii show divergent patterns of horizontal stripes and vertical bars that are partly caused by the divergence of the potassium channel gene kcnj13. Here, we show that kcnj13 is required only in melanophores for interactions with xanthophores and iridophores, which cause location-specific pigment cell shapes and thereby influence colour pattern and contrast in D. rerio. Cis-regulatory rather than protein coding changes underlie kcnj13 divergence between the two Danio species. Our results suggest that homotypic and heterotypic interactions between the pigment cells and their shapes diverged between species by quantitative changes in kcnj13 expression during pigment pattern diversification.

Rapid development of individual identification and presence systems for a critically endangered antelope, the Mountain bongo

AbstractMonitoring of species, particularly remnant populations requiring urgent conservation is often hampered by the lack of reliable tools for individual identification (using images or their spoor). Here, we develop rapid monitoring tools for individual animals of the Mountain bongo (Tragelaphus eurycerus isaaci), a critically endangered subspecies of the bongo only found in Kenya. We developed and tested an individual identification system using camera trap footage, as well as a quantitative tool to identify bongo spoor in the field, both useable by naïve observers. We implemented an information content approach to assess the importance of different visual elements in 61 individual bongos to optimise our identification system. We tested the reliability of the system with 15 naïve observers. We conclude that an optimal identification system should rely on three main visual features (stripe pattern, facial markings and horns appearance). We show that reliability amongst observers is high (κ = 0.64). We also developed a field scheme to identify footprint and spoor sign. Measurements of bongo footprints were compared with those of waterbuck (Kobus ellypsiprimnus), a syntopic antelope. Confusion occurs between spoor and footprints of both species. We find that differences in the aspect ratio of bongo and waterbuck footprints can identify the two species, 1.22 (±0.08) for bongo and 1.49 (±0.10) for waterbuck. The acquisition of reliable tools ensures monitoring activities are less dependent on individual expertise, which will allow consistent monitoring of bongo remnant populations in the future. The methods we used to develop these monitoring tools can help managers and field workers in the study of this and similar rare species where monitoring is a challenge.

Topographical surface patterning with block copolymer stamps

We explore the potential of stamps of the block copolymer (BCP) polystyrene-block-poly (2-vinylpyridine) (PS-b-P2VP) for the parallel lithographic generation of topographic surface patterns taking advantage of the specific BCP properties. A first example includes additive surface manufacturing by decal transfer microcontact lithography with PS-b-P2VP breath figure (BF) arrays. Suppression of entanglements at the internal BCP domain interfaces and the BF array morphology facilitate rupture of the thinnest wall segments in the BF arrays. The uppermost PS-b-P2VP BF array layers with heights of nearly 1 µm thus remained attached to counterpart substrates. Treatment with solvents selective to PS or P2VP enabled wettability switching of thus-functionalized surfaces. A second example includes subtractive surface manufacturing. We deposited holey films or stripe patterns of the perfluorinated alkylphosphonic acid F21-DDPA on glass substrates using PS-b-P2VP stamps penetrated by spongy mesopore systems generated by swelling-induced pore formation. The use of spongy-mesoporous stamps allows carrying out succesive stamping steps without ink replenishment. Subsequently, we topographically patterned the glass substrates by etching the parts of the glass substrates not protected by F21-DDPA with hydrofluoric acid (HF) solution. Within certain limitations, shape, area and depth of the topographic patterns may be adjusted by the etching durations. Circular PS-b-P2VP films were selectively deposited into hexagonal microwells and subjected to swelling-induced pore formation. Moreover, F21-DDPA-patterned glass substrates can be used to template the dewetting of polystyrene (PS). Arrays of PS droplets obtained in this way were in turn used as etch resists to produce arrays of glass nanoneedles. Hence, BCP stamps may be exploited to produce topographically patterned surfaces with different architectures for wettability management or graphoepitaxy.

Transcriptome analysis provides insights into the mechanism of carapace stripe formation in two closely related Marsupenaeus species

Marsupenaeus japonicus has two types of phenotypic differences that are mainly reflected in the stripe pattern of the carapace. However, the underlying mechanism regulating the stripe patterns is not clear. In the present study, we first observed the composition of pigment cells and detected the contents of different carotenoids in the carapace of M. japonicus. We clearly observed the setae structure on the carapace. There were red pigment cells in the stripe pattern and yellow pigment cells in the other parts. Both red pigment cells and yellow pigment cells showed dendritic morphology. In the carapace, the content of astaxanthin was the highest, significantly (P < 0.05) higher than that of other carotenoids. Some differentially expressed genes between two pattern types of M. japonicus, may be associated with the body color formation, such as crustacyanin (CRCN), apolipoprotein D (ApoD), tubulin alpha-1 chain, cuticle protein, and ABC transporter, which were verified by quantitative PCR experiments. The amino acid composition and secondary structure of CRCN A2, CRCN C1, and ApoD were significantly different. The results of this study will help to elucidate the molecular mechanism of the differential pattern formation of M. japonicus and provide a reference for further exploration of the formation mechanism of crustacean color.