Movement and zonation of the intertidal anemone Actinia tenebrosa Farqu. (Cnidaria: Anthozoa) under experimental conditons

1971 ◽  
Vol 22 (2) ◽  
pp. 63 ◽  
Author(s):  
JR Ottaway ◽  
IM Thomas
Keyword(s):  
High Mortality ◽  
Natural Environment ◽  
Environmental Gradients ◽  
Vertical Plane ◽  
Solid Substrate ◽  
Initial Attachment ◽  
Gastrovascular Cavity ◽  
Negative Geotaxis ◽  
Stage Of Development ◽  
Humidity Gradient

Actinia tenebrosa Farqu, is viviparous and the juvenile anemones are ejected from the gastrovascular cavity ready for immediate attachment to the first solid substrate they contact. It is several days after the initial attachment before the juveniles have the potential to move, and then it is at a rate approaching that of the adults. This may be at least 2.5 cm/hr for 8 hr and often more. When these animals are in the preferred zone in the intertidal region movement is much less. The movement of Actinia may be resolved into three categories: firstly, movement in the vertical plane, where prolonged submergence initiates negative geotaxis and prolonged emergence initiates positive geotaxis; secondly, slight inherent activity which continues even in the absence of environmental gradients; thirdly, directed lateral movements in response to stimuli other than submergence, emergence, or gravity. In the tidal tank, both adult and juvenile Actinia could be induced to form a zone in the intertidal region which corresponded to that formed in the natural environment. The distributions formed by adults and juveniles under identical conditions were significantly different although the range of the distributions was very similar. The high mortality of juveniles observed in the laboratory is attributed to the effects of dehydration during emergence, and it is suggested that at this stage of development Actinia is very susceptible to comparatively low relative humidities. The response of juvenile Actinia to a humidity gradient is examined. The zonation of Actinia tenebrosa is discussed with reference to coelenterate behaviour patterns and to the zonation of intertidal molluscs.

INFLUENCE OF DIET ON LARVAL DEVELOPMENT OF FORFICULA SENEGALENSIS SERVILLE (DERMAPTERA: FORFICULIDAE) UNDER LABORATORY CONDITIONS

1998 ◽  
Vol 130 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Ibrahim Baoua Boukary ◽  
Jean-Claude Tourneur ◽  
Jean Gingras
Keyword(s):  
Larval Development ◽  
High Mortality ◽  
Natural Environment ◽  
Adult Stage ◽  
Mixed Diet ◽  
Insect Fauna ◽  
Laboratory Conditions ◽  
Duration Of Development

AbstractThe effects of various diets composed of millet leaves and stems, millet anthers, and animal prey on the development of Forficula senegalensis Serville were studied in the laboratory using mortality, duration of development, and weight at eclosion and at imaginal moult as comparative parameters. A diet of millet leaves and stems did not allow larvae to reach the adult stage. A diet of millet anthers allowed the production of adults, but with high mortality. When fed animal prey, the larvae developed adequately into adults, but with the mixed diet (prey and millet anthers) development was more rapid and the weight of the adults produced was greater. Millet leaves are probably not an important part of larval earwigs diet in their natural environment. They do, however, eat millet anthers and they may also feed on the insect fauna that lives on millet.

scholarly journals Advances in ecological modelling of soil properties by self-organizing feature maps of natural environment of Lower Silesia (Poland)

2011 ◽  
Vol 78 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Andrzej Stankiewicz ◽  
Piotr Kosiba
Keyword(s):  
Soil Properties ◽  
Natural Environment ◽  
Environmental Changes ◽  
Parent Rock ◽  
Complex Data ◽  
Ecosystem Structure ◽  
Feature Maps ◽  
Stage Of Development ◽  
Lower Silesia ◽  
Self Organizing

The paper provides the use of self-organizing feature maps for determination of soil properties in its initial stage of development formed of massive rocks and how SOFM can be used for the study of environmental objects. The study area was Lower Silesia (Poland) overgrown with common, unique and protected vegetation of lichens, bryophytes and vascular plants. The parent rock of the studied soils consists of Miocene volcanites from the middle part of the Sudety Margin Fault. Soil samples were collected from 20 sites. The soil reaction (pH) and concentrations of Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, S, Ti, Zn in surface soils were analyzed. Statistical analysis was carried out by one-way ANOVA. The SOFM was used to demonstrate the non-linear ordination and visualization of soil properties. The SOFM showed the influence of parent rock on soil chemical properties generated by it. SOFM appeared to be effective and proper/fit for phenomena and processes taking place in natural environment and is useful in ecology and ought to be taken into account as a possible tool of estimation of various plants and their biotopes. The model can be useful as alternative techniques in modelling the ecological complex data, and provide a novel framework for the discovery and forecasting of ecosystem structure and behaviours in response to environmental changes.

THE URBAN PLANNING AS A COMPLEX ACTIVITY ORIENTED AT THE FOUNDATION OF SOCIALLY ORIENTED CITY ENVIRONMENT

2019 ◽  
pp. 94-106 ◽  
Author(s):  
Natalia Bakaeva ◽  
Liliya Chaikovskaya ◽  
Alexandra Kormina
Keyword(s):  
Urban Planning ◽  
Urban Area ◽  
Natural Environment ◽  
City Planning ◽  
Life Quality ◽  
Social Characteristics ◽  
Complex Activity ◽  
Stage Of Development ◽  
The Social ◽  
The City

Social characteristics of the life quality at the urban area and their relationship with the demographical situation and depopulation factors of the population of present-day Russia are considered in the article. Besides the demographical factor, the ecological component of most cities and locations predetermines at the stable march of the society and provides the security of the urban population vital activity. A new model of socially - oriented urban area is offered. The model is a biosphere compatible conception of the city-building, which was developed by Russian Academy of Architecture and construction sciences. The realization of the social oriented urban area consists in the close - knit execution of some principles, which are directed to the provision of har-monious balance between people and environment. According this position the formation of social -oriented ur-ban area has a connection with the necessity of the rethinking the traditional representation and guidelines and the formation of people’s world outlook in the context of common humanitarian sciences, which were made by the human at the stage of development. At the practice the creation of the social - oriented urban area should be started with the changing of the system of the city control. The system of the city control is the practice of the urban planning within city - planning complex, which is the uniting part of people’s vital activities. In this way there is no alternative of the transition to the symbiont type of relationship between the homuncle and natural environment - the urban planning systems and their natural environment. Such situation can be shown within the difficult and complex problem of the safety with the aim of the social - oriented urban area.

scholarly journals Gravitational Effects in the Collision of Elasto-Viscoplastic Drops on a Vertical Plane

Fluids ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 61 ◽  
Author(s):  
Cassio M. Oishi ◽  
Fernando P. Martins ◽  
Roney L. Thompson
Keyword(s):  
Free Surface ◽  
Vertical Plane ◽  
Solid Substrate ◽  
Surface Approach ◽  
Surface Evolution ◽  
Gravitational Effects ◽  
Practical Applications ◽  
Rich Variety ◽  
Complex Fluid ◽  
Marker And Cell Method

The collision of drops in a solid substrate is an interesting problem with several practical applications. When the drop is made of a complex fluid the problem presents numerical challenges due to the interaction of the mechanical properties and the free surface approach. In the present work, we solve the numerical problem of elasto-viscoplastic drops colliding in vertical plane. The free surface evolution is handled by a Marker-And-Cell method combined with a Front-Tracking interface representation. Special emphasis is given to the gravitational effects by means of exploring the Froude number. We were able to find a rich variety of outputs that can be classified as sticking, sliding, bouncing, detaching, and slithering.

scholarly journals Role of EXT1 and Glycosaminoglycans in the Early Stage of Filovirus Entry

2015 ◽  
Vol 89 (10) ◽  
pp. 5441-5449 ◽  
Author(s):  
Aileen O'Hearn ◽  
Minxiu Wang ◽  
Han Cheng ◽  
Calli M. Lear-Rooney ◽  
Katie Koning ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Heparan Sulfate ◽  
High Mortality ◽  
Ebola Virus ◽  
Cultured Cells ◽  
Therapeutic Potential ◽  
Therapeutic Option ◽  
Marburg Virus ◽  
Severe Illness ◽  
Initial Attachment

ABSTRACTFiloviruses, including both Ebola virus (EBOV) and Marburg virus (MARV), can infect humans and other animals, causing hemorrhagic fever with a high mortality rate. Entry of these viruses into the host is mediated by a single filoviral glycoprotein (GP). GP is composed of two subunits: GP1, which is responsible for attachment and binding to receptor(s) on susceptible cells, and GP2, which mediates viral and cell membrane fusion. Although numerous host factors have been implicated in the entry process, the initial attachment receptor(s) has not been well defined. In this report, we demonstrate that exostosin 1 (EXT1), which is involved in biosynthesis of heparan sulfate (HS), plays a role in filovirus entry. Expression knockdown of EXT1 by small interfering RNAs (siRNAs) impairs GP-mediated pseudoviral entry and that of infectious EBOV and MARV in tissue cultured cells. Furthermore, HS, heparin, and other related glycosaminoglycans (GAGs), to different extents, can bind to and block GP-mediated viral entry and that of infectious filoviruses. These results strongly suggest that HS and other related GAGs are attachment receptors that are utilized by filoviruses for entry and infection. These GAGs may have therapeutic potential in treating EBOV- and MARV-infected patients.IMPORTANCEInfection by Ebola virus and Marburg virus can cause severe illness in humans, with a high mortality rate, and currently there is no FDA-approved vaccine or therapeutic treatment available. The ongoing 2014 outbreak in West Africa underscores a lack of our understanding in the infection and pathogenesis of these viruses and the urgency of drug discovery and development. In this study, we provide several pieces of evidence that demonstrate that heparan sulfate and other closely related glycosaminoglycans are the molecules that are used by filoviruses for initial attachment. Furthermore, we demonstrate that these glycosaminoglycans can block entry of and infection by filoviruses. Thus, this work provides mechanistic insights on the early step of filoviral infection and suggests a possible therapeutic option for diseases caused by filovirus infection.

An investigation into early placental ontogeny: allantoic attachment to the chorion is selective and developmentally regulated

Development ◽  
1995 ◽  
Vol 121 (2) ◽  
pp. 407-416 ◽  
Author(s):  
K.M. Downs ◽  
R.L. Gardner
Keyword(s):  
Developmental Regulation ◽  
Initial Attachment ◽  
Developmentally Regulated ◽  
Somite Stage ◽  
Differential Adhesion ◽  
Stage Of Development ◽  
Initial Stage ◽  
Directed Growth ◽  
Do So

Culture of postimplantation conceptuses was used in conjunction with microsurgery to investigate the timing, the mechanism and the developmental regulation of chorioallantoic fusion in the mouse. The timing of fusion was determined in both freshly recovered conceptuses and in those that had been cultured from as early as the mid-streak stage. Attachment of the allantois to the chorion was found to have occurred in most conceptuses by the 6-somite stage, irrespective of whether they had been cultured. In investigating the mechanism of fusion, we wished to determine whether it depended on directed growth of the allantoic bud or on its differential adhesion to the chorion. Microsurgery was used to transplant allantoic tissue into the exocoelomic cavity of conceptuses from which the resident allantois had been removed. In synchronous grafting experiments, transplanted allantoises typically attached to the chorion despite loss of their connection with the hindgut region of the fetus. Hence selective attachment of the allantois to the chorion clearly cannot depend simply on its directed growth. While the transplanted allantoic tissue attached to the chorion selectively, it did not attach to it precociously, despite being favourably positioned to do so. These findings argue that the initial attachment of the allantois to the chorion depends on a selective adhesive mechanism that is developmentally regulated. Further grafting experiments in which donor conceptuses were either more or less advanced than hosts revealed that attachment of the allantois to the chorion depends primarily on the stage of the allantois rather than on the stage of the chorion. Collectively, these findings support the hypothesis that the initial stage of chorioallantoic fusion depends on selective adhesion between regionally differentiated mesodermal surfaces which is governed principally by the stage of development of the allantois.

scholarly journals RNAi-Mediated Silencing of Pgants Shows Core 1 O-Glycans Are Required for Pupation in Tribolium castaneum

2021 ◽  
Vol 12 ◽  
Author(s):  
Weidong Li ◽  
Kristof De Schutter ◽  
Els J. M. Van Damme ◽  
Guy Smagghe
Keyword(s):  
Embryonic Development ◽  
Tribolium Castaneum ◽  
High Mortality ◽  
Developmental Stages ◽  
Single Gene ◽  
Protein Glycosylation ◽  
Red Flour Beetle ◽  
Initial Attachment ◽  
Post Translational Modifications ◽  
Flour Beetle

Protein glycosylation is one of the most common and most important post-translational modifications. Despite the growing knowledge on N-glycosylation, the research on O-glycosylation is lagging behind. This study investigates the importance of O-glycosylation in the post-embryonic development of insects using the red flour beetle, Tribolium castaneum, as a model. We identified 28 O-glycosylation-related genes (OGRGs) in the genome of the red flour beetle. 14 OGRGs were selected for functional analysis based on their involvement in the initial attachment of the carbohydrate in the different O-glycosylation pathways or the further elongation of the most abundant O-glycans and, in addition, showing severe RNAi-induced phenotypes in Drosophila melanogaster. The expression profile of these OGRGs was mapped throughout the developmental stages of the insect and in the different tissues of the pupa and adult. Subsequently, these genes were silenced using RNA interference (RNAi) to analyze their role in development. A broad spectrum of phenotypes was observed: from subtle effects and disrupted wing formation when silencing the genes involved in O-mannosylation, to blockage of pupation and high mortality after silencing of the genes involved in O-GalNAc and core 1 O-glycan (O-GalNAc-Gal) synthesis. RNAi experiments were also performed to assess the effects of blocking multiple pathways of O-glycosylation. However, the observed phenotypes induced by multiple RNAi were similar to those of the single gene RNAi experiments. The silencing of OGRGs often resulted in high mortality and wing phenotypes, indicating the importance of O-glycosylation for the survival of the insect and the formation of wings during the post-embryonic development of T. castaneum.

SCULPTURE PARKS OF THE XX CENTURY LAST THIRD – THE XXI CENTURY BEGINNING: TYPOLOGY EXPERIENCE

2021 ◽  
pp. 80-94
Author(s):  
Irina A. Steklova ◽  
◽  
Olesya I. Raguzhina ◽  
Keyword(s):  
Natural Environment ◽  
Art History ◽  
Representative Sample ◽  
Decorative Arts ◽  
Self Presentation ◽  
Stage Of Development ◽  
New Material ◽  
Integrated Or ◽  
North And South America ◽  
North And South

The purpose of this article is to present sculpture parks at the modern stage of development, from the last third of the 20th century to our day. The relevance of this purpose is due to the relevance of these parks, which meets, firstly, on the challenges of culture, reproducing itself in the synthesis of landscape and monumental-decorative arts; secondly, on the demands of the population in artistically interpreted natural spaces; thirdly, on the life-building claims of modern art, which is looking for optimal ways of self-presentation. The representation of the sculpture parks is implied their systematization, which, in the course of the factual and visual material analysis, exhibits the most typical trends of formal and informative diversity and takes the form of a typology. To start building a typology, it was necessary to draw up a rather broad and spacious representative sample of objects and to select reference criteria in the trends of the manifold. Thus, a representative sample was made up of 90 Europe, Asia, Africa, Australia, and North and South America brightest objects, and following criteria were put forward: environmental involvement, authorship, the nature of specific forms and links between them. Typology showed that approximately two thirds of the sculpture parks are a product of the natural environment and one third of the architectural environment. In the natural environment, in authentic natural spaces, these are co-author full (independent and contextual) and special (by place, material, style, theme) formats, as well as mono-author formats. In an architectural environment, in integrated or interpreted natural spaces, these are, first of all, city formats that can be both co-authors and mono-authors: destinations, stops, transit zones. The implementation of the typology was facilitated by the attraction of a new material for the national art history. In the scientific circulation were introduced information about objects that were not mentioned before and unknown artists. Accounting for this information, along with known realities, allowed us to reach a higher understanding level of sculpture parks as a modern hypostasis of artistic synthesis.

Three-dimensional anatomy of the 8-day mouse conceptus: a study by scanning electron microscopy

Development ◽  
1976 ◽  
Vol 36 (3) ◽  
pp. 575-596
Author(s):  
A. Tamarin ◽  
A. Boyde
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Three Dimensional ◽  
Vertical Plane ◽  
Single Layer ◽  
Squamous Cells ◽  
Stage Of Development ◽  
Relationship Of ◽  
Columnar Cells ◽  
Scanning Electron

The three-dimensional anatomy of the 8-day mouse conceptus was studied by scanning electron microscopy aided by microdissection within the microscope specimen chamber. Attention was given to the relationship of the extra-embryonic membranes and their subtended compartments and particular emphasis was placed on the ‘inverted’ condition of the embryo at this stage of development. The main points brought forth in this study are: (1) the five basic brain segments are discernible on the basis of surface contours; (2) the cervical fold, extending from the ventrum of the metencephalon to the somatopleure, forms a partition which separates the branchial region from the rest of the amniotic space; (3) the procephalic membrane bifurcates in a vertical plane to form the splanchnopleure and somatopleure lateral to the forebrain, and it bifurcates horizontally to form the dorsal and ventral coverings of the pericardial coelom; (4) the antrum of the pericardial—peritoneal canal opens into the lateral coelom posterior to the cervical fold; (5) the midgut of the embryo is delineated laterally by longitudinal grooves connecting the foregut and hindgut antra; (6) embryonic ectoderm in the neural-fold region is formed by a single layer of pseudostratified columnar cells; (7) the allantois is hollow near its base and the inner surface is formed by a discontinuous layer of squamous cells; (8) blood islands in the extra-embryonic mesoderm form a ring of bulges around the middle of the exocoel. Other structures such as the ectoplacental cavity, the ectoplacental cone and the parietal capsule are also described.

Random isn't real: How the patchy distribution of ecological rewards may generate “incentive hope”

2019 ◽  
Vol 42 ◽  
Author(s):  
Laurel Symes ◽  
Thalia Wheatley
Keyword(s):  
Natural Environment ◽  
Random Distribution ◽  
Spatiotemporal Distribution ◽  
Patchy Distribution ◽  
Distribution Of Resources

AbstractAnselme & Güntürkün generate exciting new insights by integrating two disparate fields to explain why uncertain rewards produce strong motivational effects. Their conclusions are developed in a framework that assumes a random distribution of resources, uncommon in the natural environment. We argue that, by considering a realistically clumped spatiotemporal distribution of resources, their conclusions will be stronger and more complete.

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