Spider dragline silk is of practical interest because of its excellent mechanical properties. However, the structure of this material is still largely unknown. In this article, we report what we believe is a new model of the hierarchical structure of silk based on scanning electron microscope and atomic force microscope images. This hierarchical structure includes beta-sheet, polypeptide chain ...

Synthetic biomolecular spiders with "legs" made of single-stranded segments of DNA can move on a surface which is also covered by single-stranded segments of DNA complementary to the leg DNA. In experimental realizations, when a leg detaches from a segment of the surface for the first time it alters that segment, and legs subsequently bind to these altered segments more weakly. Inspired by thes...

Defects of peripheral nerves still represent a challenge for surgical nerve reconstruction. Recent studies concentrated on replacement by artificial nerve conduits from different synthetic or biological materials. In our study, we describe for the first time the use of spider silk fibres as a new material in nerve tissue engineering. Schwann cells (SC) were cultivated on spider silk fibres. Cel...

One hundred twenty female participants, with varying levels of spider fear were asked to complete an automated 8-step perceived-threat behavioral approach test (PT-BAT). The steps involved asking the participants if they were willing to put their hand into a number of opaque jars with an incrementally increasing risk of contact with a spider (none of the jars actually contained a spider). There...

Cardiac reactions to two fear-related and one control film were compared in individuals high in spider or blood/injury fear. Twelve subjects in each phobic group were selected on the basis of their scores in the Spider or Mutilation Questionnaires and a semi-structured interview. Cardiac responses and self-reported affective ratings to the films were investigated. Sympathetic and parasympatheti...

Simple spider diagrams are a system of Venn-type diagrams that can be used to reason diagrammatically about sets, their cardinalities and their relationships. They extend the systems of Venn-Peirce diagrams investigated by Shin to include lower bounds for the cardinalities of the sets represented by the diagrams. This paper summarises the main syntax and semantics of simple spider diagrams and ...

1Department of Cognitive Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel, 2Numerical Cognition Laboratory, Department of Psychology, Brain and Mind Institute, The University of Western Ontario, London, ON, Canada, 3Department of Psychology, Columbia University, New York, NY, USA, 4Department of Psychology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, B...

Noise sensitivity of functions on the leaves of a binary tree is studied, and a hypercontractive inequality is obtained. We deduce that the spider walk is not noise stable. Introduction For the simplest random walk (Fig. 1a), the set Ω n of all n-step trajectories may be thought of either as (the set of leaves of) a binary tree, or (the vertices of) a binary cube {−1, +1}n. However, consider an...

Due to their inherent compliance, soft actuated joints are becoming increasingly important for robotic applications, especially when human-robot-interactions are expected. Several of these flexible actuators are inspired by biological models. One perfect showpiece for biomimetic robots is the spider leg, because it combines lightweight design and graceful movements with powerful and dynamic act...

Comprehensive characterization of ultrafast optical field is critical for ultrashort pulse generation and its application. This paper combines two-step phase-shifting (TSPS) into the spectral phase interferometry for direct electric-field reconstruction (SPIDER) to improve the reconstruction of ultrafast optical-fields. This novel SPIDER can remove experimentally the dc portion occurring in tra...