Academic literature on the topic 'Textual morphogenesis'

Differentiating tension wood was observed in order to analyse the changes occurring during cell wall morphogenesis. Specimens were taken from trees in Guyana. Wall texture was analysed by means of ultrastructural cytochemistry. Modifications were encountered in fibre and vessel walls of tension wood when compared to typical wood. The changes were twofold: variation in the layering of polylamellate walls, and the deposition of a gelatinous layer in the fibre cell walls. Results are discussed in terms of variations in the rhythmic nature of cell wall deposition. Data confirm that the morphogenesis of the wall is a modular process allowing the cells to adapt to growth constraints.

This article presents an abstract computation model of the evolution of camouflage in nature. The 2D model uses evolved textures for prey, a background texture representing the environment, and a visual predator. A human observer, acting as the predator, is shown a cohort of 10 evolved textures overlaid on the background texture. The observer clicks on the five most conspicuous prey to remove (“eat”) them. These lower-fitness textures are removed from the population and replaced with newly bred textures. Biological morphogenesis is represented in this model by procedural texture synthesis. Nested expressions of generators and operators form a texture description language. Natural evolution is represented by genetic programming (GP), a variant of the genetic algorithm. GP searches the space of texture description programs for those that appear least conspicuous to the predator.

In this communication, we report a facile nanotopographical control over a stainless steel surface via an electrophoretic deposition of colloidal amphiphilic chitosan for preferential growth, proliferation or migration of vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs). Atomic force microscopy revealed that the colloidal surface exhibited a deposition time-dependent nanotopographical evolution, wherein two different nanotopographic textures indexed by ‘kurtosis’ ( R kur ) value were easily designed, which were termed as ‘sharp’ (i.e. high peak-to-valley texture) surface and ‘flat’ (i.e. low peak-to-valley texture) surface. Cellular behaviour of VSMCs and HUVECs on both surfaces demonstrated topographically dependent morphogenesis, adherent responses and biochemical properties in comparison with bare stainless steel. The formation of a biofunctionalized surface upon a facile colloidal chitosan deposition envisions the potential application towards numerous biomedical devices, and this is especially promising for cardiovascular stents wherein a new surface with optimized texture can be designed and is expected to create an advantageous environment to stimulate HUVEC growth for improved healing performance.

Correct orientation of cell division is extremely important in the maintenance, regeneration, and repair of continuously proliferating tissues, such as the epidermis. Regulation of the axis of division of epidermal cells prevents the apoptosis-induced compensatory proliferation, and eventually the cancer. Thus, the orientation of cell division is critical for maintaining the tissue architecture. In this study, we investigated the effects of S. europaea extract on the texture of human skin and the behavior of these cells during skin morphogenesis. In sun-exposed skin, S. europaea improved the texture. A multilayered, highly differentiated in vitro skin model indicated that, S. europaea extract suppressed the UVB-induced changes in the morphology of basal keratinocytes. Orientation of cell division was determined by measuring the axis of mitosis in the vertical sections of our experimental model. Analyses of the digital images revealed that S. europaea preserved the axis of division of basal keratinocytes from UVB-induced perturbations. Our findings uncover a new mechanism by which S. europaea responds to the spindle misorientation induced by UVB.

Localized deformation patterns are a common motif in morphogenesis and are increasingly finding applications in materials science and engineering, in such instances as mechanical memories. Here, we describe the emergence of spatially localized deformations in a minimal mechanical system by exploring the impact of growth and shear on the conformation of a semi-flexible filament connected to a pliable shearable substrate. We combine numerical simulations of a discrete rod model with theoretical analysis of the differential equations recovered in the continuum limit to quantify (in the form of scaling laws) how geometry, mechanics and growth act together to give rise to such localized structures in this system. We find that spatially localized deformations along the filament emerge for intermediate shear modulus and increasing growth. Finally, we use experiments on a 3D-printed multi-material model system to demonstrate that external control of the amount of shear and growth may be used to regulate the spatial extent of the localized strain texture.

The wing scales of the Green Hairstreak butterfly Callophrys rubi consist of crystalline domains with sizes of a few micrometers, which exhibit a congenitally handed porous chitin microstructure identified as the chiral triply periodic single-gyroid structure. Here, the chirality and crystallographic texture of these domains are investigated by means of electron tomography. The tomograms unambiguously reveal the coexistence of the two enantiomeric forms of opposite handedness: the left- and right-handed gyroids. These two enantiomers appear with nonequal probabilities, implying that molecularly chiral constituents of the biological formation process presumably invoke a chiral symmetry break, resulting in a preferred enantiomeric form of the gyroid structure. Assuming validity of the formation model proposed by Ghiradella H (1989) J Morphol 202(1):69–88 and Saranathan V, et al. (2010) Proc Natl Acad Sci USA 107(26):11676–11681, where the two enantiomeric labyrinthine domains of the gyroid are connected to the extracellular and intra-SER spaces, our findings imply that the structural chirality of the single gyroid is, however, not caused by the molecular chirality of chitin. Furthermore, the wing scales are found to be highly textured, with a substantial fraction of domains exhibiting the <001> directions of the gyroid crystal aligned parallel to the scale surface normal. Both findings are needed to completely understand the photonic purpose of the single gyroid in gyroid-forming butterflies. More importantly, they show the level of control that morphogenesis exerts over secondary features of biological nanostructures, such as chirality or crystallographic texture, providing inspiration for biomimetic replication strategies for synthetic self-assembly mechanisms.

The area of investigation lies between Maneri and Gangnani along the Bhagirathi river in the lesser and central Himalayan block of Garhwal Himalayas. The rocks of Garhwal group are represented by quartzites, sericite quartzite’s and talc chlorite schist intruded by metabasics, whereas the Central crystallines are constituted by gneisses, schists, migmatites and amphibolites. For the purpose of drainage basin morphometric analysis 100 third order drainage basins were marked. Drainage basin morphometric parameters of 100 basins were calculated. On the basis of lithology and tectonic setup,the area was divided into three morphogenetic units viz Central crystallines, Thrust zone and Garhwal group. The basins which were situated below 2500 mts are categorized under low altitudes and above 2500 as basins of higher altitudes.The relationship between deainage basinmorphometric parameters and altitude suggest that basins situated at higher altitude have higher value of stream frequency, number of first and second order streams,fine texture and low drainage density.

Cell wall microfibril alignment in the tubular portion of Equisetum hyemale root hairs is helicoidal. Lamellae of helicoidal texture are deposited from tip to base; thus, different microfibril orientations are aligned with the plasma membrane successively. Zones with constant mean microfibril orientation are about 300 μm long. In any such zone of dry-cleaned, shadowed preparations, the frequency of microfibrils at the proximal end is 5 to 7 microfibrils per micrometre, which decreases to 0 at the distal end. The orientation of microfibrils of the underlying lamella, the microfibril frequency of which is 5 to 7/μm throughout, is the same as the microfibril orientation of the neighbouring distal lamella. Microfibrils of the cell wall are randomly oriented in the hair dome. Microtubule alignment in these root hairs was examined by means of freeze substitution. In the extreme tip of the root hair, microtubules run parallel to the plasma membrane and transverse to the long axis of the hair; the hemisphere of the hair contains randomly oriented microtubules. From extreme tip to base of the hair dome, microtubules become more and more axially aligned, and remain axially oriented in the hair tube. Further down the hair, where microfibril alignment is transverse and microfibrils are actively being deposited, microtubules still run in the axial direction. The observations emphasize the involvement of microtubles in root hair tip morphogenesis, but not in determining the alignment of the microfibrils in the hair tube.

The paper establishes the general features of the soil morphogenesis in ravined forests of Dnieper Prysamaria and genetic relationships of forest soils with zonal chernozem under herbaceous associations based on the detection of morphological properties that are «lithogenic», that is inherited from deluvial material and «pedogenic» features formed directly in the forest soil. The study area is located on the Dnieper Prysamaria (Dnipropetrovsk region) within the area of the steppes. The trial areas are incorporated in the upper Deep ravine, located in the upland part of watershed landscape. Catena is represented by five typical sections – between edging of the ravined forest and the field in the middle thirds of the slopes of the northern and southern exposures and in the thalweg of the ravine. Samples for meso-morphological studies were selected by genetic horizons, samples for soil horizons were selected using a soil drill. Basic morphological characteristics were determined in the laboratory (except for the hardness index). The mathematical processing of the results was carried out by methods of nonparametric statistics (method K-means). It was found that, despite the temporal and spatial disorder of deluvial material deposition processes and the differences of the water regime in the thalweg on the slopes, in the ravined biogeocenoses the forest soils are formed with common features of morphological organization of the genetic profile of the individual and morphological properties. The uniformity of the general structure is shown in a set sequence and the power of the genetic horizons, polycyclic and texture eluvial-illuvial differentiation of the genetic profile. The uniformity of the changes in the profile of the individual morphological properties is shown in the form of colour options of genetic horizons (due to humus content talus deposits), changing the particle size distribution of horizons in accordance with the general differentiation profile on eluvial and illuvial (due lessivage) part, changes in the morphology and dimensions of structural units related to changes in the structure of hardness horizons intensive leaching of carbonates from the profile of forest soils. The necessity of research processes clayization profile in situ, their role in the morphogenesis of compacted horizons are noted. There are two groups of properties that make it possible to analyze the micromorphology level communication between the soils in the catena. The first – a lithogenic conditionally or diluvial material properties, which persist for a long time in a forest soil – granulometry and less coloration horizons. The second – a pathogenic properties, sharply differing in the studied soils associated with the peculiarities of morphogenesis of a particular genetic profile and specific genetic horizon. These include the level of occurrence of carbonates in the profile and intensity of effervescence, the morphology of the structural units, the hardness of the genetic horizons, the level of spot colour. Cluster analysis identified a statistically illustrates the differences between the morphological structure of the soil catena, combining in one cluster the ravined soils on deluvial deposits under forest vegetation, and in the other – the soils on the loess under herbaceous vegetation. The contrast of differences increases down the profile.

Placental chorionic surface vascular networks (PCSVNs) are essential high-capacitance, low-resistance distribution and drainage networks, and are hence important to placental function and to fetal and newborn health. It was hypothesized that variations in the PCSVN structure may reflect both the overall effects of genetic and environmentally regulated variations in branching morphogenesis within the conceptus and the fetus’s vital organs. A critical step in PCSVN analysis is the extraction of blood vessel structure, which has only been done manually through a laborious process, making studies in large cohorts and applications in clinical settings nearly impossible. The large variation in the shape, color, and texture of the placenta presents significant challenges to both machine and human to accurately extract PCSVNs. To increase the visibility of the vessels, colored paint can be injected into the vascular networks of placentas, allowing PCSVNs to be manually traced with a high level of accuracy.This paper provides a proof-of-concept study to explain the geometric differences between manual tracings of paint-injected and un-manipulated PCSVNs under the framework of a shape-context model. Under this framework, paint-injected and un-manipulated tracings of PCSVNs can be matched with nearly 100% accuracy. The implication of our results is that the manual tracing protocol yields faithful PCSVN representations modulo a set of affine transformations, making manual tracing a reliable method for studying PCSVNs. Our work provides assurance to a new pre-processing approach for studying vascular networks by ways of dye-injection in medical imaging problems.

Five image processing algorithms are proposed to measure the average orientation, eccentricity and size of cells in images of biological tissue. These properties, which can be embodied by an elliptical 'composite cell', are crucial for biomechanical tissue models. To automatically determine these properties is challenging due to the diverse nature of the image data, with tremendous and unpredictable variability in illumination, cell pigmentation, cell shape and cell boundary visibility. One proposed algorithm estimates the composite cell properties directly from the input tissue image, while four others estimate the properties from frequency domain data. The accuracy and stability of the algorithms are quantitatively compared through application to a wide variety of real images. Based on these results, the best algorithm is selected.

This project was developed as an attempt to assess the relationship between different morphogenetic processes, in particular, those of fringe belt formation as described by M.R.G. Conzen (1960) and Whitehand (2001), and of centrality and compactness as described by Hillier (1999; 2002). Different approaches’ focus on different elements of the city has made it difficult to establish exactly how these processes interact or whether they are simply different facets of development reflecting wider socio-economic factors. To address this issue, a visual, chronological timeline of Limassol’s development was constructed along with a narrative of the socio-economic context of its development. The complexity of cities, however, makes static visualisations across time difficult to read and assess alongside textual narratives. We therefore took the step of developing an animation of land use and configurational analyses of Limassol, in order bring to life the diachronic analysis of the city and shed light on its generative mechanisms. The video presented here shows that the relationship between the processes mentioned above is much stronger and more complex than previously thought. The related paper explores in more detail the links between fringe belt formation as a cyclical process of peripheral development and centrality as a recurring process of minimisation of gains in distance. The project’s outcomes clearly show that composite methods of visualisations are an analytical opportunity still little exploited within urban morphology. References Conzen, M.R.G., 1960. Alnwick, Northumberland: A Study in Town-Plan Analysis, London: Institute of British Geographers. Hillier, B., 2002. A Theory of the City as Object: or how spatial laws mediate the social construction of urban space. Urban Des Int, 7(3–4), pp.153–179. Hillier, B., 1999. Centrality as a process: accounting for attraction inequalities in deformed grids. Urban Des Int, 4(3–4), pp.107–127. Whitehand, J.W.R., 2001. British urban morphology: the Conzenian tradition. Urban Morphology, 5(2), pp.103–109.