scholarly journals Unique behavioural modifications in the web structure of the cave orb spider Meta menardi (Araneae, Tetragnathidae)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel Simonsen ◽  
Thomas Hesselberg
Keyword(s):  
Foraging Behaviour ◽  
Model Organism ◽  
Spider Web ◽  
Web Structure ◽  
Morphological Adaptations ◽  
Ecological Complexity ◽  
Surface Dwelling ◽  
Web Asymmetry ◽  
The Web ◽  
Behavioural Adaptations

AbstractIn the last decade there has been a renewed interest in the study of behavioural adaptations to environmental constraints with a focus on adaptations to challenging habitats due to their reduced ecological complexity. However, behavioural studies on organisms adapted to nutrient poor subterranean habitats are few and far between. Here, we compared both morphological traits, in terms of relative leg lengths, and behavioural traits, captured in the geometry of the spider web, between the cave-dwelling spider, Meta menardi, and two aboveground species from the same family (Tetragnathidae); Metellina mengei and Tetragnatha montana. We found that the webs of the cave spider differed significantly from the two surface-dwelling species. The most dramatic difference was the lack of frame threads with the radii in the webs instead attaching directly to the surrounding rock, but other differences in relative web size, web asymmetry and number of capture spiral threads were also found. We argue that these modifications are likely to be adaptations to allow for a novel foraging behaviour to additionally capture walking prey within the vicinity of the web. We found only limited evidence for morphological adaptations and suggest that the cave orb spider could act as a model organism for studies of behaviour in energy-poor environments.

scholarly journals Argiope bruennichi (Scopoli, 1772) Örümceğinin Ağ Yapısı ve Örü Aygıtının Morfolojisi

2021 ◽  
Vol 9 (3) ◽  
pp. 577-583
Author(s):  
İlkay Çorak Öcal ◽  
Nazife Yiğit Kayhan ◽  
Ümmügülsüm Hanife Aktaş
Keyword(s):  
Structural Organization ◽  
Spider Silk ◽  
Spider Species ◽  
Spider Web ◽  
Web Spider ◽  
Web Structure ◽  
The World ◽  
Terrestrial Life ◽  
The Web ◽  
Scanning Electron

Spiders are one of the groups that best adapted to terrestrial life among in invertebrates and are represented by approximately 48,000 species in the world. Although all spiders do not weave webs, the webs of spiders are literally a work of art. The main reason for spider web weaving is hunting. Some spider species live in the nature dependent on the own web, while others continue to live without being dependent on the own web. Although basic taxonomic features generally remain unchanged, some spider-silk weaving apparatus may undergo adaptive variations. In this study, the web structure of the weaving web spider, Argiope bruennichi (Scopoli, 1772) and the structural organization of the web weaving apparatus was observed by using scanning electron microscopy (SEM). The web structure of A. bruennichi, spinnerets especially posterior spinneret and arrangement of its spigots are shown and discussed in the light of the literature.

PAPER PHYSICS. The web structure in relation to the furnish composition and shoe press pulse profiles during wet pressing

2012 ◽  
Vol 27 (4) ◽  
pp. 798-805 ◽  
Author(s):  
Collin Hii ◽  
Øyvind W. Gregersen ◽  
Gary Chinga-Carrasco ◽  
Øyvind Eriksen ◽  
Kai Toven
Keyword(s):  
Porous Structure ◽  
Peak Pressure ◽  
Pulse Length ◽  
Pressure Profile ◽  
Steam Consumption ◽  
Web Structure ◽  
Wet Pressing ◽  
Solids Content ◽  
In The Beginning ◽  
The Web

Abstract This study shows that wet-pressing TMP and DIP with a shoe press pulse may yield similar afterpress solids, provided that an adequate shoe pulse length with similar pressure profile is applied. A wet web with more porous structure in the sheet dewatering (felt) layer seems to contribute to the increased dewatering during wet pressing. In addition, a shoe press pulse with high peak pressure at the end yields higher solids content after wet-pressing and higher bulk compared to a pulse with a peak pressure in the beginning. The increased dewatering during wet-pressing implies a reduction of steam consumption in the dryer.

scholarly journals Functional analysis of the food web of Bahia Magdalena, Baja California Sur, Mexico

2017 ◽  
Vol 41 (3) ◽  
pp. 519-544
Author(s):  
Víctor H. Cruz-Escalona ◽  
María V. Morales-Zárate ◽  
Andrés F. Navia ◽  
Juan M. Rguez-Baron ◽  
Pablo Del Monte-Luna
Keyword(s):  
Trophic Levels ◽  
Baja California Sur ◽  
Ecopath With Ecosim ◽  
Estuarine Ecosystem ◽  
Energy Control ◽  
Marine Communities ◽  
Web Structure ◽  
The World ◽  
The Web ◽  
Bahia Magdalena

In the present study we developed a trophic model (ECOPATH with ECOSIM), to describe the structure and functioning of Bahía Magdalena estuarine ecosystem. The model, constituted by 24 functional groups, indicates that one third of the total ecosystem biomass is produced by secondary and tertiary trophic levels. The magnitude of total flows in the system and the transfer efficiency among trophic levels, are similar to those observed in other tropical systems around the world. A large proportion of the total flows are directed to the maintenance of the trophic web structure. The value of the connectance index (CI) was 0.2, meaning that there is only 20% of realized connections within the web. Benthic primary producers contribute with 53% of the total ascendency. We believe that the energy control in this particular ecosystem is top-down type (through the main predators), suggesting that high-trophic level species negatively affect other groups in the system. This trophic model can be used for exploring different hypothesis concerning the biotic and abiotic mechanisms that modify the structure and functioning of the Bahía Magdalena ecosystem, with the ultimate goal of understanding how this attributes determine the resilience of marine communities.

The northernmost record of Eriostethus rufus (Uchida, 1932) (Hymenoptera, Ichneumonidae) with an indication of new host, Trichonephila clavata (Koch, 1878) (Araneae, Araneidae) and its web manipulation

2021 ◽  
Vol 3 ◽  
pp. ec03015
Author(s):  
Keizo Takasuka
Keyword(s):  
Dna Barcoding ◽  
New Host ◽  
Web Structure ◽  
Inverted Triangle ◽  
Orb Web ◽  
The Web ◽  
Northern Japan

Eriostethus rufus (Uchida, 1932) is a polysphinctine ectoparasitoid of araneid spiders (Neoscona spp.) and is endemic to Japan. An individual was collected in Yamagata Prefecture (38º46' N), northern Japan, the northernmost record of the species and also the genus. Its identification was confirmed by morphology and by DNA barcoding. The cocoon was found in a large modified web, which is unique in that the web structure is shaped like an inverted triangle extending to over 50 cm with the cocoon hanging from an ill-defined part of the cocoon web without any organized structure surrounding the cocoon. The host spider of this individual appears to be Trichonephila clavata (Koch, 1878) (Araneidae, Nephilinae) based on several circumstantial evidences. The structure of the modified web suggests that the pre-existing web was partly reused, the orb web was completely removed, and sustaining threads of the barrier web would be newly moored to the substrates. This record means that E. rufus parasitises host spiders of two subfamilies, which is unusual for the group.

An Insight of Machine Learning in Web Network Analysis

2019 ◽  
Vol 11 (2) ◽  
pp. 20-34
Author(s):  
Meenakshi Sharma ◽  
Anshul Garg
Keyword(s):  
Machine Learning ◽  
Machine Learning Techniques ◽  
Effective Solution ◽  
Business Organisation ◽  
Web Structure ◽  
Learning Techniques ◽  
Effective Decision ◽  
Effective Decision Making ◽  
The Given ◽  
The Web

The World Wide Web is immensely rich in knowledge. The knowledge comes from both the content and distinctive characteristics of the web like its hyperlink structure. The problem comes in digging the relevant data from the web and giving the most appropriate decision to solve the given problem, which can be used for improving any business organisation. The effective solution of the problem depends on how efficiently and effectively the analysis of the web data is done. In analysing the data on web, not only relevant content analysis is essential but also the analysis of web structure is important. This article gives a brief introduction about the various terminologies and measures like centrality, Page Rank, and density used in the web networking analysis. This article will also give a brief introduction about the various supervised ML techniques such as classification, regression, and unsupervised machine learning techniques such as clustering, etc., which are very useful in analysing the web network so that user can make quick and effective decision making

scholarly journals WormBase: a modern Model Organism Information Resource

2019 ◽  
Author(s):  
Todd W Harris ◽  
Valerio Arnaboldi ◽  
Scott Cain ◽  
Juancarlos Chan ◽  
Wen J Chen ◽  
...  
Keyword(s):  
Model Organism ◽  
Model System ◽  
Information Resource ◽  
Biological Processes ◽  
Web Interface ◽  
Nematode Caenorhabditis Elegans ◽  
Founding Member ◽  
The Status ◽  
The Web ◽  
Literature Curation

Abstract WormBase (https://wormbase.org/) is a mature Model Organism Information Resource supporting researchers using the nematode Caenorhabditis elegans as a model system for studies across a broad range of basic biological processes. Toward this mission, WormBase efforts are arranged in three primary facets: curation, user interface and architecture. In this update, we describe progress in each of these three areas. In particular, we discuss the status of literature curation and recently added data, detail new features of the web interface and options for users wishing to conduct data mining workflows, and discuss our efforts to build a robust and scalable architecture by leveraging commercial cloud offerings. We conclude with a description of WormBase's role as a founding member of the nascent Alliance of Genome Resources.

CREATING TOOLS IN A SOFTWARE ENVIRONMENT BASED ON GRAPH REWRITING RULES

2000 ◽  
Vol 10 (02) ◽  
pp. 153-183
Author(s):  
A. DE LUCIA ◽  
G. TORTORA ◽  
M. TUCCI
Keyword(s):  
Software Development ◽  
Software Evolution ◽  
Mathematical Concept ◽  
Tool Development ◽  
Program Transformations ◽  
Software Environment ◽  
Web Structure ◽  
High Level ◽  
Rewriting Rules ◽  
The Web

This paper presents the software development workbench WSDW (Web structure-oriented Software Development Workbench) together with the tool development language TDL. WSDW is an integrated structure-oriented software environment which contains several tools for software evolution. The integration of tools is achieved by sharing a program representation which is based upon the mathematical concept of relation: the web structure is the basic high level representation of programs within the environment. The TDL language is a structure-oriented language that supports the creation of a wide variety of tools both for software development and maintenance. The elementary statements in a TDL program are web rewriting rules and manipulations of programs are expressed as web transformations. Moreover, to make program transformations more intuitive to the tool programmer, web rewriting rules are expressed graphically. Each tool in WSDW performs a sequence of web transformations and new software tools can be implemented as TDL programs and integrated into WSDW.

scholarly journals In situ three-dimensional spider web construction and mechanics

2021 ◽  
Vol 118 (33) ◽  
pp. e2101296118
Author(s):  
Isabelle Su ◽  
Neosha Narayanan ◽  
Marcos A. Logrono ◽  
Kai Guo ◽  
Ally Bisshop ◽  
...  
Keyword(s):  
Self Assembly ◽  
High Performance ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Hierarchical Structures ◽  
Spider Webs ◽  
Spider Web ◽  
Web Geometry ◽  
Under Construction ◽  
The Web

Spiders are nature’s engineers that build lightweight and high-performance web architectures often several times their size and with very few supports; however, little is known about web mechanics and geometries throughout construction, especially for three-dimensional (3D) spider webs. In this work, we investigate the structure and mechanics for a Tidarren sisyphoides spider web at varying stages of construction. This is accomplished by imaging, modeling, and simulations throughout the web-building process to capture changes in the natural web geometry and the mechanical properties. We show that the foundation of the web geometry, strength, and functionality is created during the first 2 d of construction, after which the spider reinforces the existing network with limited expansion of the structure within the frame. A better understanding of the biological and mechanical performance of the 3D spider web under construction could inspire sustainable robust and resilient fiber networks, complex materials, structures, scaffolding, and self-assembly strategies for hierarchical structures and inspire additive manufacturing methods such as 3D printing as well as inspire artistic and architectural and engineering applications.

scholarly journals Detail-design Guidance for the Openings on the Web Structure Supporting the Deck

2007 ◽  
Vol 44 (6) ◽  
pp. 612-618
Author(s):  
Sung-Chan Kim ◽  
Kyung-Seok Lee ◽  
Jae-Young Song ◽  
Kyung-Su Kim
Keyword(s):  
Detail Design ◽  
Web Structure ◽  
The Web ◽  
Design Guidance
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