769 research outputs found

    Ulva as potential stimulant and attractant for a valuable sea urchin species: a chemosensory study

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    The green seaweed Ulva is close to becoming popular due to its suitability as potential feedstock production and for food items. However, there is a general lack of studies on the aversion or acceptability of this alga by marine organisms, particularly on its role as a chemoattractant and/or phagostimulant activity. Here we tested the effect of Ulva compressa and other biochemicals as potential chemostimulating compounds for a valuable sea urchin species, Paracentrotus lividus, selected as model species for our tests. Sea urchins’ chemical sensitivity was estimated by analysing movements of spines, pedicellariae, tube feet, and individual locomotion using an innovative bioassay. Our results showed that all forms of Ulva (fresh, defrosted, and fragmented) resulted in an effective stimulus, evoking in sea urchins strong responses with robust activation of spines and tube feet, where the defrosted one was the most stimulating. Among the amino acids tested, glycine, alanine, and glutamine produced a significant response, highlighting for the latter a concentration–response relationship. Sea urchins responded to glucose, not to fructose and sucrose. Spirulina resulted as the most effective stimulus, acting in a dose-dependent manner. Major results indicate the role of Ulva as a chemostimulant and strongly attractant for such herbivore species. From an applied point of view, the presence of potential Ulva’s feed-related compounds, acting as chemoattractants (to reduce food searching time) and/or feeding stimulants (to stimulate ingestion), would improve the several applications of Ulva in the formulation of the feeds for sustainable aquacultur

    optical coherence tomography angiography in optic nerve sheath meningioma

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    This study describes Spectral Domain-Optical Coherence Tomography (SD-OCT) and Optical Coherence Tomography Angiography (OCTA) features of Optic Nerve Sheath Meningioma (ONSM).A 22-year-old woman, diagnosed with meningioma encircling the right optic nerve inside the intraorbital segment optic canal at the magnetic resonance imaging, showed a normal fundus examination.Instead, SD-OCT and OCTA revealed alterations in the neurostructure and microvascular network of the optic nerve.Despite fundoscopy and fluorescein angiography, SD-OCT and OCTA represent valid, non-invasive and reliable methods to evaluate neurostructural and vascular irregularities in this benign tumor of the optic nerve. Keywords: Optic nerve sheath meningioma, OCT angiography, SD-OC

    Heparan sulfate phage display antibodies recognise epitopes defined by a combination of sugar sequence and cation binding.

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    Phage display antibodies are widely used to follow heparan sulfate (HS) expression in tissues and cells. We demonstrate by ELISA, that cations alter phage display antibody binding profiles to HS and this is mediated by changes in polysaccharide conformation, demonstrated by circular dichroism spectroscopy. Native HS structures, expressed on the cell surfaces of neuroblastoma and fibroblast cells, also exhibited altered antibody binding profiles following exposure to low mM concentrations of these cations. Phage display antibodies recognise conformationally-defined HS epitopes, rather than sequence alone, as has been assumed, and resemble proteins in being sensitive to changes in both charge distribution and conformation following binding of cations to HS polysaccharides

    Learning to Extract Motion from Videos in Convolutional Neural Networks

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    This paper shows how to extract dense optical flow from videos with a convolutional neural network (CNN). The proposed model constitutes a potential building block for deeper architectures to allow using motion without resorting to an external algorithm, \eg for recognition in videos. We derive our network architecture from signal processing principles to provide desired invariances to image contrast, phase and texture. We constrain weights within the network to enforce strict rotation invariance and substantially reduce the number of parameters to learn. We demonstrate end-to-end training on only 8 sequences of the Middlebury dataset, orders of magnitude less than competing CNN-based motion estimation methods, and obtain comparable performance to classical methods on the Middlebury benchmark. Importantly, our method outputs a distributed representation of motion that allows representing multiple, transparent motions, and dynamic textures. Our contributions on network design and rotation invariance offer insights nonspecific to motion estimation

    Re-identification of a lamnid shark embryo

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    nant female lamnid shark was caught that the morphometric arguments in the Strait of Messina, Mediterra- used by Sanzo (1912) did not rule out nean Sea. She was reported to contain the shortfin mako (Isurus oxyrinchus 25–30 embryos, one of which was Rafinesque, 1810) but that the high saved and taken to the local Marine fecundity of 25–30 was more consis-Institute, where it was subsequently tent with C. carcharias than with I. examined by Sanzo (1912). The male oxyrinchus or a Lamna species. A lack embryo measured 36.1 cm total length of information on lamnid reproduction (TL), weighed 800 g, and had a greatly and the misidentification of a likely distended abdomen, as is typical of Galeorhinus galeus (Stevens2) with a embryos of oophagous lamnoid sharks litter of 30 as Lamna by Neill (1811), (Gilmore, 1993). The mother and the may have led Sanzo (1912) to consider remaining embryos were not saved. the porbeagle Lamna nasus (Bon-Because Sanzo was not able to exam- naterre, 1788) instead of the shortfin ine the adult female from which the mako as the most likely alternativ

    Community resilience assessment integrating network interdependencies

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    The concept of Disaster Resilience has received considerable attention in recent years and it is increasingly used as an approach for measuring response of communities to natural disasters. Recently a framework named PEOPLES has been developed by MCEER to measure performance of communities to natural disasters. The method includes seven dimensions that include both technical and socio-economic aspects. All resilience dimensions and their respective indices to measure community performances are obviously interdependent. As first step, the physical dimension has been implemented in software and indices have been proposed to measure performance of buildings and lifelines. This paper tries to focus on developing methodologies to consider interdependencies between buildings (e.g. hospitals, strategic buildings, etc) and lifelines (road networks, etc.). An approach considering network interdependencies have been developed which is based on the time series analysis of the restoration curves of the different infrastructures. The case study of 2011 Tohoku Earthquake has been presented to illustrate the implementations issue

    Riqueza, endemismo y conservaciĂłn de los mamĂ­feros de Colombia

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    We update the list of Colombian mammal species based upon a new revision of specimens in the major collections within and outside the country and a compilation of recent taxonomic changes of species present in the country. The result of these changes is a total of 492 native species, which represents a net increment of 62 species with respect to the previous list published in the year 2000, and this exceeds similar updates in other Neotropical countries. Although the level of knowledge differs greatly between groups, we provide some general indicators, as diversity on the level of orders, endemism, patterns of distribution, and conservation state. The greatest species richness occurs in the orders Chiroptera (198 spp.) and Rodentia (122 spp.), but there are 23 endemic species of rodents in contrast to only seven endemic bats. According to the nature and scale of the evaluations, between 39 (MAVDT) and 52 (IUCN) species of Colombian mammals are considered to be endangered. The major threats are still deforestation, hunting and illegal commerce
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