Spider web anthropologies: ecologies, infrastructures, entanglements

Ecologies, infrastructures, entanglements. Anthropology and STS have recently found some unsuspected common groundings in the relational, emergent and self-organizational affordances of these three conceptual systems. Vibrant yet fragile, interactive and responsive whilst simultaneously resilient and solicitous, the earthy and muddled and tenacious engagements afforded by ‘ecologies’, ‘infrastructures’ and ‘entanglements’ have brought new sources of analytical vitality and valence to social theory. These are languages of description that conjure worlds of material and biotic interdependencies, human and non-human agencies weaving themselves into and around filaments of energy, matter, history and decay. Worlds that hold on; worlds that creep up. Spider worlds and spider webs calling for spider web anthropologies. In this chapter I want to introduce the figure of the spider web as a heuristic to helps us think our current predicament of expulsion, ruin and precarity. The spider web, I want to suggest, offers an apposite metaphor for a world that holds itself in precarious balance, that tenses itself with violence and catastrophe but also grace and beauty, and that calls out and silhouettes promissory worlds of entanglements. However, what draws me to the metaphoric seduction of the spider web, I must add, is one specific trait: its semblance and vocation as a trap. Spider webs are traps. It is their materiality as traps, their condition as material and epistemic interfaces between worlds, that helps us ‘capture’ new openings for the work of imagination and description today. I am interested in the work that traps can do for description, in the trap as a method for description. The spider web offers a beautiful example of how this method works: the spider web entangles the worlds of prey and predator and in so doing outlines and crystallizes the infrastructure of their ecologies. The spider-web-trap is an ecology, but it is also an entanglement, and it is also an infrastructure. I shall return to each one of these registers in some more detail shortly. The method of description that the spider-web-trap sets in motion is a specific type of ‘recursive’ operation: think of the spider’s spinning of the web, eating part of it daily to recuperate some of the energy expended in spinning. The operation of recursion works therefore as a source environment for future descriptions and an environmental palette itself. We may think of it as a technique of ‘double environmentalisation’: weaving worlds into existence at the same time as it re-captures existing worlds. Describing worlds and worldling descriptions. Worlds that hold on, worlds that creep up.Peer reviewe

Prey localization in spider orb webs using modal vibration analysis

Spider webs are finely tuned multifunctional structures, widely studied for their prey capture functionalities such as impact strength and stickiness. However, they are also sophisticated sensing tools that enable the spider to precisely determine the location of impact and capture the prey before it escapes. In this paper, we suggest a new mechanism for this detection process, based on potential modal analysis capabilities of the spider, using its legs as distinct distributed point sensors. To do this, we consider a numerical model of the web structure, including asymmetry in the design, prestress, and geometrical nonlinearity effects. We show how vibration signals deriving from impacts can be decomposed into web eigenmode components, through which the spider can efficiently trace the source location. Based on this numerical analysis, we discuss the role of the web structure, asymmetry, and prestress in the imaging mechanism, confirming the role of the latter in tuning the web response to achieve an efficient prey detection instrument. The results can be relevant for efficient distributed impact sensing applications

Case study on spider-net enthrophy investigation in rural areas

The theoretical background of the research was published in 2012. We present a part of a result of a complex research, in which we investigated spider-net entrophy from the development aspects of rural areas. The paper introduces a new type of situation analyses as a case study. The selected study area is Veresegyház micro region. Based on the complexity of inequalities of the territories is not advantageous to do an examination only in one dimension NAGY- KÁPOSZTA (2006). KÁPOSZTA et al. (2008) highlight the subsystems of the development are in sum and part relationship with each other, and they act as a sensitive system. The abstract way of thinking the meaning of entropy theory formed the so-called spider web-entropy analysis, which helps to find out how the structure order between the pillars of the spider web is

Novel Approaches to Exploring Silk Use Evolution in Spiders

Spider silk is enigmatic, and web structure, design, and adult morphology of the spinning apparatus of spiders once informed how systematists approached the spider phylogeny. The orb-web and adaptation of viscous silk was considered a key innovation leading to rapid diversification of spiders. However, the advent of molecular techniques including recent phylogenomics studies, overturned this major paradigm in spider evolution. Clades once considered monophyletic are no more. The orb-web is not a pinnacle of evolution, and the former sister group, using cribellate silk (loops of fibrils combed from a specialized silk plate on the abdomen), is now sister to the predominately non-silk using RTA clade with a more ancient common orb-web ancestor. Little work has explored the ontogeny of the spinning apparatus in spiders, but by doing so, one could find empirical support for the paradigm shift in the new Araneae Tree of Life (AToL), such as orb-weaving traits within the RTA clade. To address this, Tengella perfuga, a rare cribellate-silk using member of the RTA clade, was selected for a case study of natural history, including web ontogeny. The full spigot ontogeny of T. perfuga was characterized and compared with previous studies of both orb-weaving and RTA clade members. Using a pooled ontogeny dataset across studies, including lab populations of Hogna carolinensis and Dolomedes tenebrosus, potential drivers of spigot number across spider lineages was explored using the AToL in PGLS analyses. There were vestiges of orb-weaving behavior within the web spinning of Tengella perfuga, and a trio of silk spigots that may be homologous with the trio of viscous orb-weavers. PGLS analyses of female and second instar spigot data, resulted in maximum number of instars, foraging strategy and variety of spigots possessed significantly correlated to specific spigot numbers. An ancestral character estimation analysis performed on the unique spigots, such as the trio, found some preliminary evidence for, but not confirming, homology. This study utilized novel techniques to explore spider silk use evolution. With deeper taxon sampling and improved statistical methods allowing the full ontogeny to be included in PGLS analyses, a better understanding of silk use evolution will emerge

Model Spider: Learning to Rank Pre-Trained Models Efficiently

Figuring out which Pre-Trained Model (PTM) from a model zoo fits the target task is essential to take advantage of plentiful model resources. With the availability of numerous heterogeneous PTMs from diverse fields, efficiently selecting the most suitable PTM is challenging due to the time-consuming costs of carrying out forward or backward passes over all PTMs. In this paper, we propose Model Spider, which tokenizes both PTMs and tasks by summarizing their characteristics into vectors to enable efficient PTM selection. By leveraging the approximated performance of PTMs on a separate set of training tasks, Model Spider learns to construct tokens and measure the fitness score between a model-task pair via their tokens. The ability to rank relevant PTMs higher than others generalizes to new tasks. With the top-ranked PTM candidates, we further learn to enrich task tokens with their PTM-specific semantics to re-rank the PTMs for better selection. Model Spider balances efficiency and selection ability, making PTM selection like a spider preying on a web. Model Spider demonstrates promising performance in various configurations of model zoos

A social spider algorithm for global optimization

The growing complexity of real-world problems has motivated computer scientists to search for efficient problem-solving methods. Metaheuristics based on evolutionary computation and swarm intelligence are outstanding examples of nature-inspired solution techniques. Inspired by the social spiders, we propose a novel social spider algorithm to solve global optimization problems. This algorithm is mainly based on the foraging strategy of social spiders, utilizing the vibrations on the spider web to determine the positions of preys. Different from the previously proposed swarm intelligence algorithms, we introduce a new social animal foraging strategy model to solve optimization problems. In addition, we perform preliminary parameter sensitivity analysis for our proposed algorithm, developing guidelines for choosing the parameter values. The social spider algorithm is evaluated by a series of widely used benchmark functions, and our proposed algorithm has superior performance compared with other state-of-the-art metaheuristics.postprin

Production and Purification of Synthetic Minor Ampullate Silk Proteins

Spider silks are incredible natural materials that have a wide variety of properties that can rival or outperform even common synthetic materials like Nylon and Kevlar. As nature’s architects, orb-weaving spiders spin seven different silks that are used for very specific roles throughout the spider’s lifecycle. These silks are comprised of proteins called spidroins. Each of these spidroins has evolved to have properties such as strength and/or stretch that make these silks successful and highly adapted in their designated roles in web construction, prey capture and reproduction. This study involves the production of minor ampullate silk by genetically modifying the bacteria Escherichia coli. Minor ampullate is a lesser studied silk that is used for the first spiral of the orb web. This spiral is a template that the spider uses to finish the web and provides stability during the web construction. Minor ampullate silk is strong, however it does not stretch so it may be well-suited for certain applications such as ballistic materials. By producing and purifying different arrangements of minor ampullate silk protein, it is possible to learn how this protein can be expressed without using the spider itself. This investigation sheds light on how deviations in the protein sequence and motif arrangement can produce different properties, which can potentially be used to make new materials

Molecular, behavioral and anatomical sophistication in spider webs: insights from spinning gland RNA-seq experiments in primitive and modern spiders.

RNA-seq experiments conducted in 454 sequencers were carried out to produce 87.000 short-reads representing the transcriptome of two spiders'spinning glands. We produced sequences from (i) Actinopus sp., a spider from the Mygalomorphae clade, and (ii) Gasteracantha cancriformis, an Orbicularia spider. Mygalomorphae spiders are known to retain a number of primitive morphological and behavioral characters. They use mixtures of a primitive web, soil, and plants only to cover a burrow they make on the ground for shelter and predation.On the other hand, Orbicularia spiders show a number of derivative spider's characters and they are capable to build different and complex silks used in a variety of situations. It is interesting to note that the complexity of web production, usage and behavior in these spiders is reflected both by (i) the variety of the repertoire of protein molecules (spidroins) they use to make their webs and (ii) the complexity of their anatomical spinning gland apparatu used to produce silk. Here we have first conducted a broad analysis of the spinning gland transcriptome in both spiders producing unigenes and categorizing annotated genes in biological functions.Then we started to analyze the number and variety of spider silk proteins and families found in different spider clades.We have shown that spiders using web only for a limited number of situations present a less sophisticated morphological spinning apparatus and produce a small repertoire of spidroin molecules. Phylogenetic analyses were conductedin the 3'region of spidroins and we try to relate (i) the evolution of silk protein families,(ii) the evolutionary complexification of silk production behavior and web usage, and (iii) the appearance of new specialized spinning glands along the evolution of specimens and clades in the Araneae order