scholarly journals Sculpting crystals one Burgers vector at a time: Toward colloidal lattice robot swarms

2021 ◽  
Vol 118 (3) ◽  
pp. e2017377118
Author(s):  
Bryan VanSaders ◽  
Sharon C. Glotzer
Keyword(s):  
Shape Change ◽  
Crystalline Materials ◽  
Robot Swarms ◽  
Variable Diameter ◽  
Colloidal Matter ◽  
Multiple Cycles ◽  
The Creation ◽  
Embedded Clusters ◽  
And Migration ◽  
External Forces

Plastic deformation of crystalline materials with isotropic particle attractions proceeds by the creation and migration of dislocations under the influence of external forces. If dislocations are produced and migrated under the action of local forces, then material shape change can occur without the application of surface forces. We investigate how particles with variable diameters can be embedded in colloidal monolayers to produce dislocations on demand. We find in simulation that when embedded clusters of variable diameter particles are taken through multiple cycles of swelling and shrinking, large cumulative plastic slip is produced by the creation and biased motion of dislocation pairs in the solid for embedded clusters of particular geometries. In this way, dislocations emitted by these clusters (biased “dislocation emitters”) can be used to reshape colloidal matter. Our results are also applicable to larger-scale swarms of robotic particles that organize into dense ordered two-dimensional (2D) arrangements. We conclude with a discussion of how dislocations fulfill for colloids the role sought by “metamodules” in lattice robotics research and show how successive applications of shear as a unit operation can produce shape change through slicing and swirling.

scholarly journals Rationale for the creation of the National natural park «Central Podillya»

2021 ◽  
Author(s):  
О. Mudrak ◽  
G. Mudrak ◽  
V. Serebryakov ◽  
A. Shcherbliuk ◽  
V. Klochaniuk
Keyword(s):  
Protected Areas ◽  
Local Population ◽  
Field Research ◽  
Pilot Project ◽  
Landscape Diversity ◽  
Forest Steppe ◽  
Migration Routes ◽  
Balanced Development ◽  
The Creation ◽  
And Migration

Based on comprehensive environmental monitoring, geobotanical, zoogeographical, landscape-ecological, hydro-ecological, forest-typological, agroecological principles and approaches and own field research it is proposed to create a national nature park (NNP) «Central Podillya» within Vinnytsia region. A promising NNP is planned to be created on the territory of Vinnytsia and Khmilnytsky administrative districts of Vinnytsia region as a habitat and migration routes of bison (Bison bonasus) and preservation of unique biotic and landscape diversity. The projected area of NPP «Central Podillya» is 53 820 hectares. The need to create a park due to the presence of natural (forest, wetland, peat-swamp, floodplain, meadow, forest-steppe, meadow-steppe, steppe, weed-field) complexes with associations of plant groups, where more than 40 species of plants and lives more than 50 species of animals listed in the RBU, as well as the presence of a significant number of objects that have historical, cultural, recreational, health (medical) value. The general ecological and geographical characteristics of the park from the standpoint of physical-geographical and geobotanical zoning are given. There are 34 objects of the nature reserve fund (NRF), which will be a part of the perspective park. Functional zoning of the territory of the projected NNP «Central Podillya» was carried out taking into account representative and rare ecosystems, where its 4 zones (protected, regulated recreation, stationary recreation, economic) were allocated. The structural elements of the ecological network of the perspective park are singled out. The necessity of protection, preservation and reproduction of biotic and landscape diversity and historical and cultural heritage of the studied territory through the greening of economic activity, education and culture of the local population is substantiated. It was found that the creation of NPP «Central Podillya» through the Presidential Decree and the optimization of protected areas, which account for 2.27% of the total area of Vinnytsia region, the implementation of regional ecological and Emerald networks is an extremely important, important and absolutely necessary for effective adjustment of the strategy of balanced development of territorial communities. Creation of NPP «Central Podillya» will increase the percentage of protected areas to 4.5% of the total area of Vinnytsia region. According to this indicator Vinnytsia region is in one of the last places in Ukraine. According to the Institute of World Resources (Washington), for the effective functioning of the territory, the area of its reserves should be at least 10–12%. Preparation of scientific substantiation and project of creation of NPP «Central Podillya» within Vinnytsia region is a pilot project that requires official detailing, delimitation, land management, coordination with land users on which the park will be located, creation of park directorate, introduction of technologies aimed at preservation and restoration of biogeocenotic cover, reproduction of broken types of connections, preservation of settlements, optimization of land use, balanced development of territorial communities that will be a part of the NNP.

scholarly journals La coherencia entre los marcos normativos de Naciones Unidas, la Unión Europea y el Estado español. El caso de las políticas de cooperación y la dimensión exterior de la política migratoria

2017 ◽  
pp. 189
Author(s):  
Nerea Azkona
Keyword(s):  
United Nations ◽  
Shared Responsibility ◽  
Development Cooperation ◽  
Migration Policies ◽  
The Creation ◽  
The United Nations ◽  
And Migration ◽  
Migration And Development ◽  
The Eu

<p>This article aims to clarify the coherence between the policies of cooperation and migration of the Spanish State as a member of the EU and the United Nations. We have considered the crossroads of the concepts of development, migration and cooperation development in the scope of work of the CPD, which advocates shared responsibility in the field of migration and development. If the objective of the development cooperation is the creation of conditions that favour the development of societies and people in conditions of poverty and exclusion, are the migration policies consistent with this objective? What degree of inconsistency are we willing to take?</p><p><strong>Received</strong>: 31 May 2015<br /><strong>Accepted</strong>: 15 October 2015<br /><strong>Published online</strong>: 11 December 2017</p>

scholarly journals Memories of a Lost Home: Intizar Husain’s Basti

2016 ◽  
Vol 6 (3) ◽  
pp. 482-488
Author(s):  
Varun Dev Vasishtha
Keyword(s):  
Indian Subcontinent ◽  
The Novel ◽  
Political Situation ◽  
The Creation ◽  
And Migration

In this paper, Intizar Husain’s novel on Partition, Basti is examined which depicts the human denouement that followed Partition of the Indian subcontinent in 1947. The novel looks back at the aftermath of Partition after more than two decades, talks about the turmoil caused by the socio-political situation in Pakistan and the realization that the Partition was an ever going on event. The process of separate homeland for Muslims, the chief motive that resulted in Partition, was reversed with the secession of Bangladesh. Partition and migration have failed to provide stability to the migrants. Intizar Husain has recaptured the agony of Partition after a lapse of two decades. The novel, dealing with the Muslim perspective of Partition, depicts the plight of the members of the community who crossed over to Pakistan with the euphoria of the creation of a separate homeland, fail to realise their hopes. Feeling of alienation has been delineated in a highly subtle manner.

Plasticity of the actin cytoskeleton in response to extracellular matrix nanostructure and dimensionality

2014 ◽  
Vol 42 (5) ◽  
pp. 1356-1366 ◽  
Author(s):  
Josefine Starke ◽  
Bernhard Wehrle-Haller ◽  
Peter Friedl
Keyword(s):  
Extracellular Matrix ◽  
Actin Cytoskeleton ◽  
Shape Change ◽  
Leading Edge ◽  
High Speeds ◽  
Efficient Induction ◽  
Important Input ◽  
Single Force ◽  
And Migration

Mobile cells discriminate and adapt to mechanosensory input from extracellular matrix (ECM) topographies to undergo actin-based polarization, shape change and migration. We tested ‘cell-intrinsic’ and adaptive components of actin-based cell migration in response to widely used in vitro collagen-based substrates, including a continuous 2D surface, discontinuous fibril-based surfaces (2.5D) and fibril-based 3D geometries. Migrating B16F1 mouse melanoma cells expressing GFP–actin developed striking diversity and adaptation of cytoskeletal organization and migration efficacy in response to collagen organization. 2D geometry enabled keratinocyte-like cell spreading and lamellipod-driven motility, with barrier-free movement averaging the directional vectors from one or several leading edges. 3D fibrillar collagen imposed spindle-shaped polarity with a single cylindrical actin-rich leading edge and terminal filopod-like protrusions generating a single force vector. As a mixed phenotype, 2.5D environments prompted a broad but fractalized leading lamella, with multiple terminal filopod-like protrusions engaged with collagen fibrils to generate an average directional vector from multiple, often divergent, interactions. The migratory population reached >90% of the cells with high speeds for 2D, but only 10–30% of the cells and a 3-fold lower speed range for 2.5D and 3D substrates, suggesting substrate continuity as a major determinant of efficient induction and maintenance of migration. These findings implicate substrate geometry as an important input for plasticity and adaptation of the actin cytoskeleton to cope with varying ECM topography and highlight striking preference of moving cells for 2D continuous-shaped over more complex-shaped discontinuous 2.5 and 3D substrate geometries.

scholarly journals Acquisition of cellular properties during alveolar formation requires differential activity and distribution of mitochondria

2021 ◽  
Author(s):  
Kuan Zhang ◽  
Erica Yao ◽  
Julia Wong ◽  
Paul J. Wolters ◽  
Pao-Tien Chuang
Keyword(s):  
Epithelial Cells ◽  
Mitochondrial Function ◽  
Shape Change ◽  
Alveolar Epithelial Cells ◽  
Mitochondrial Activity ◽  
Cellular Functions ◽  
Alveolar Epithelial ◽  
Cell Shape Change ◽  
And Migration ◽  
Alveolar Formation

AbstractAlveolar formation requires coordinated movement and interaction between alveolar epithelial cells, mesenchymal myofibroblasts and endothelial cells/pericytes to produce secondary septa. These processes rely on the acquisition of distinct cellular properties to enable ligand secretion for cell-cell signaling and initiate morphogenesis through cell migration and cell shape change. In this study, we showed that mitochondrial activity and distribution play a key role in bestowing cellular functions on both alveolar epithelial cells and mesenchymal myofibroblasts for generating secondary septa to form alveoli. These results suggest that mitochondrial function is tightly regulated to empower cellular machineries in a spatially specific manner. Indeed, such regulation via mitochondria is required for secretion of platelet-derived growth factor from alveolar epithelial cells to influence myofibroblast proliferation and migration. Moreover, mitochondrial function enables myofibroblast migration during alveolar formation. Together, these findings yield novel mechanistic insights into how mitochondria regulate pivotal steps of alveologenesis. They highlight selective utilization of energy and diverse energy demands in different cellular processes during development. Our work serves as a paradigm for studying how mitochondria control tissue patterning.

scholarly journals Smallpox Mortality in a Ural City (with Reference to Early 20th-Century Yekaterinburg)

2021 ◽  
Vol 23 (4) ◽  
pp. 246-267
Author(s):  
Iulia V. Borovik ◽  
Keyword(s):  
Medical Intervention ◽  
Smallpox Vaccination ◽  
Early 20Th Century ◽  
Old Believers ◽  
Wide Range ◽  
The Creation ◽  
And Migration ◽  
Medical Infrastructure ◽  
The City ◽  
Central Urals

Smallpox has long been among the infections causing colossal fatalities in epidemics. The creation of a smallpox vaccine in the late eighteenth century helped improve the situation significantly. However, due to a wide range of reasons, some of which were common for many states and some reflected the country’s specificity, it took almost two centuries to introduce vaccination and combat the disease. This time was required not only for the creation of medical structures that provided smallpox vaccination. A considerable obstacle was the prejudice against medical intervention shared by many people, and relative control over the disease was gained only after fear was replaced by an understanding of necessity and appropriateness. High mortality was connected both with health care issues and the existing system of values which was changing more dynamically in cities. This article is devoted to the situation with mortality from smallpox in the early twentieth century in Yekaterinburg, a large commercial, industrial, transport, administrative, and cultural centre of the Central Urals with a population of diverse confessions. The source of data for statistical analysis is registers of city parishes of all religious denominations in the city. The author mostly focuses on three denominations, i.e. Orthodox Christians, Old Believers, and Muslims. The analysis reveals the dependence of mortality of the people’s religion and migration statuses. The results of the research testify to the fact that the medical infrastructure and the level of anti-smallpox measures were effective and helped maintain control over the disease and prevent epidemics of smallpox despite the intense influx of migrants to the city from places where acknowledgement of the need for vaccination was lower and opportunities to carry it out were scarcer.

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