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Sant'Anna, Italy

Tramacere F.,Italian Institute of Technology | Tramacere F.,The BioRobotics Institute | Beccai L.,Italian Institute of Technology | Kuba M.J.,Hebrew University of Jerusalem | Mazzolai B.,Italian Institute of Technology
Marine and Freshwater Behaviour and Physiology | Year: 2013

In the literature, a reference terminology for labelling octopus arms exists, but a convention for the labelling of octopus suckers is so far lacking. The precise identification and subsequent ability to address a specific sucker is impossible without some type of convention. In this work, we propose an Octopus Sucker Identification Code, with three/five characters, depending on whether the octopus species has one or two rows of suckers. Specifically, two characters identify the arm to which the sucker belongs, one integer identifies the sucker position along the arm and two subscript characters (present in cases of octopus species with two rows of suckers) identify the adjacent arm towards which the sucker is faced. The proposed code allows the unequivocal identification of the suckers of any octopus arm of any octopus species. © 2013 The Author(s). Published by Taylor & Francis. Source

Martini A.,University of Pisa | Tavarini S.,University of Pisa | Macchia M.,University of Pisa | Benelli G.,University of Pisa | And 3 more authors.
Plant Biosystems | Year: 2016

Stevia rebaudiana (Bert.) Bertoni has sporophytic self-incompatibility and this may lead to poor seed yield and quality, which are obstacles to large-scale crop establishment. This research investigated the influence of insect pollinators and the harvesting time on the qualitative and quantitative characteristics of the ripe seeds. A pot trial under open field conditions was established to evaluate the abundance of insect pollinators and three harvesting times on the production of ripe seeds, germination percentage, mean germination time and thousand seed weight (TSW) in 36 F1 open-pollinated genotypes. Large variability in the number of corymbs of capitula, flowering time, reproductive period and seed yield was observed among the genotypes. Genotypes with promising phenological and reproductive properties were identified. The worst germination percentage and TSW were recorded in the latest harvest. Significant linear regressions were found among the investigated parameters (insect number, germination percentage, TSW, seeds yield per plant and cycle length), confirming complex interactions on the yield and quality of stevia seeds. Results indicate that earlier flowering genotypes produced higher seed quantity, due to favourable weather conditions during the reproductive phase. Moreover, cross-pollination and the insect abundance, as Apidae and Syrphidae, play a crucial role for enhancing the stevia seed yield and quality. © 2016 Società Botanica Italiana Source

Barbaglio A.,University of Milan | Tricarico S.,University of Milan | Tricarico S.,The BioRobotics Institute | Ribeiro A.R.,University of Porto | And 13 more authors.
Zoology | Year: 2015

The viscoelastic properties of vertebrate connective tissues rarely undergo significant changes within physiological timescales, the only major exception being the reversible destiffening of the mammalian uterine cervix at the end of pregnancy. In contrast to this, the connective tissues of echinoderms (sea urchins, starfish, sea cucumbers, etc.) can switch reversibly between stiff and compliant conditions in timescales of around a second to minutes. Elucidation of the molecular mechanism underlying such mutability has implications for the zoological, ecological and evolutionary field. Important information could also arise for veterinary and biomedical sciences, particularly regarding the pathological plasticization or stiffening of connective tissue structures. In the present investigation we analyzed aspects of the ultrastructure and biochemistry in two representative models, the compass depressor ligament and the peristomial membrane of the edible sea urchin Paracentrotus lividus, compared in three different mechanical states. The results provide further evidence that the mechanical adaptability of echinoderm connective tissues does not necessarily imply changes in the collagen fibrils themselves. The higher glycosaminoglycan (GAG) content registered in the peristomial membrane with respect to the compass depressor ligament suggests a diverse role of these molecules in the two mutable collagenous tissues. The possible involvement of GAG in the mutability phenomenon will need further clarification. During the shift from a compliant to a standard condition, significant changes in GAG content were detected only in the compass depressor ligament. Similarities in terms of ultrastructure (collagen fibrillar assembling) and biochemistry (two alpha chains) were found between the two models and mammalian collagen. Nevertheless, differences in collagen immunoreactivity, alpha chain migration on SDS-PAGE and BLAST alignment highlighted the uniqueness of sea urchin collagen with respect to mammalian collagen. © 2015 Elsevier GmbH. Source

Marianelli P.,The BioRobotics Institute | Berthoz A.,College de France | Bennequin D.,University Paris Diderot
Biological Cybernetics | Year: 2014

The crista ampullaris is the epithelium at the end of the semicircular canals in the inner ear of vertebrates, which contains the sensory cells involved in the transduction of the rotational head movements into neuronal activity. The crista surface has the form of a saddle, or a pair of saddles separated by a crux, depending on the species and the canal considered. In birds, it was described as a catenoid by Landolt et al. (J Comp Neurol 159(2):257–287, doi:10.1002/cne.901590207, 1972). In the present work, we establish that this particular form results from principles of invariance maximization and energy minimization. The formulation of the invariance principle was inspired by Takumida (Biol Sci Space 15(4):356–358, 2001). More precisely, we suppose that in functional conditions, the equations of linear elasticity are valid, and we assume that in a certain domain of the cupula, in proximity of the crista surface, (1) the stress tensor of the deformed cupula is invariant under the gradient of the pressure, (2) the dissipation of energy is minimum. Then, we deduce that in this domain the crista surface is a minimal surface and that it must be either a planar, or helicoidal Scherk surface, or a piece of catenoid, which is the unique minimal surface of revolution. If we add the hypothesis that the direction of invariance of the stress tensor is unique and that a bilateral symmetry of the crista exists, only the catenoid subsists. This finding has important consequences for further functional modeling of the role of the vestibular system in head motion detection and spatial orientation. © 2014, Springer-Verlag Berlin Heidelberg. Source

News Article
Site: http://www.rdmag.com/rss-feeds/all/rss.xml/all

The octopus is a fascinating creature. It’s perhaps one of the most alien-looking lifeforms that calls the Earth home. They can flush their skin a variety of colors, and contort their bodies to fit through holes as small as one inch in diameter. It’s that latter flexibility that’s made the octopus a model for soft robots. In late April, ten teams will compete in Livorno, Italy in the first RoboSoft Grand Challenge, which will be hosted by the RoboSoft collaboration. “The RoboSoft Grand Challenge aims at inspiring and pushing innovations in robotics technology and includes tasks in three different challenge scenarios: ‘Terrestrial race,’ ‘Manipulation,’ (and) ‘Underwater race,’” according to RoboSoft. In the challenge, the robots will be tasked with racing across a sand pit, opening a door by its handle, grabbing a variety of objects, and navigating around obstacles, according to Nature News. The idea of soft robots isn’t new. In fact, researchers have been experimenting in the field for a number of years now. One of the people advancing the field is Cecilia Laschi, of The BioRobotics Institute and the Scuola Superiore Sant’Anna, Italy. Laschi also serves as the coordinator for RoboSoft. Previously, Laschi and colleagues developed a soft robot tentacle prototype capable of mirroring an octopus’ tentacle locomotion. Unlike hard-bodied robots, soft robots are designed without a skeleton. This allows them to potentially bypass any problems posed by rigidity. Researchers in the field are also looking at caterpillars, jellyfish, and other flexible creatures for inspiration. DARPA is even experimenting with soft exoskeletons for the military. Laschi told Nature News that she envisions soft robots eventually being combined with traditional robotics. Her colleagues at Kings College London are developing a surgical endoscope based on her previous work, the media outlet reported. The challenge is part of the second Soft Robotics Week, which will be held from April 25 to 30.

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