984 research outputs found
Light and Shape: A Contribution to Demonstrate Morphological Differences in Diurnal and Nocturnal Teleosts
No full text11 pages, 5 figures,1 table.Light intensity is an important environmental
factor affecting the structure of fish assemblages
during the day–night cycle. Light influences how organisms
perceive their environment, modulating their intraspecific
and interspecific relationships. The relationship
between light intensity variations and biological cycles
should be observed at the level of organismal morphology.
In this study the relationship between activity
rhythms, thus light intensity experienced by fish in the
period of major activity and external morphology, have
been investigated. The morphological traits of 97
selected fish species were compared in order to determine
the existence of a common morphological plan in
agreement with their diurnal or nocturnal activity
rhythm. Species sorting was performed by maximizing
the diversity of activity rhythm, habitat choice, ecology,
and trophic habits within the same family, to assess the
importance of the day–night cycle on species morphology
in relation to other environmental features. The morphological
characters selected for the geometric morphometric
analysis were body profile and the position of mouth,
eye, pelvic, pectoral, dorsal, and caudal fin. The present
analysis allowed different consensus forms for nocturnal
and for diurnal species to be identified. Two-block Partial
Least Squares analysis was then performed for the
purpose of modeling the covariation between the form
and two important external variables (ecology and activity).Ministero Italiano per le Politiche Agricole
e Forestali; Contract grant number: Law 41/82.
J. Aguzzi is a postdoctoral fellow
(Programa Juan de la Cierva), sponsored by Ministerio
de Educacio´n y Cultura, Espa˜na.Peer reviewe
Engineering Distributed Collective Intelligence in Cyber-Physical Swarms
No full textCyber-physical swarms represent a paradigm shift in distributed systems, mirroring characteristics akin to natural swarms, such as self-organization, scalability, and fault tolerance. This paper delves into these complex systems, characterized by vast networks of cyber-physical entities with limited environmental awareness, yet capable of exhibiting emergent collective behaviors. These systems encompass a diverse array of scenarios, ranging from swarm robotics to the interconnectivity in smart cities, as well as the collaboration among augmented humans. The engineering of such systems presents unique challenges, primarily due to their intricate complexity and the spontaneous nature of their collective behaviors.This paper aims to dissect these challenges, offering a clear delineation of potential approaches. We present a comprehensive analysis, shedding light on the intricacies of engineering cyber-physical swarms and discussing modern solutions in engineering collective applications for such systems
Shape analysis of different populations of clams in relation to their geographical structure
No full text10 pages, 6 figures, 5 tables.Bivalves are excellent candidates for geographically based studies of the morphological variation in individuals of different populations based on the analysis of their shape profiles. In this study, we quantified the overall shell shape differences in individuals of different populations of Ruditapes decussatus and Ruditapes philippinarum in relation to their geographical and genetic distances. A total of 395 and 124 individuals of R. decussatus (nine populations) and R. philippinarum (four populations), respectively, were sampled in different Mediterranean and Atlantic coastal locations. Pictures of the left valve were taken from all individuals. Their profiles were analysed using elliptic Fourier analysis. Mean outlines were computed. In order to classify different individuals for species, the coefficients of harmonic equations were analysed by partial least square discriminant analysis and soft independent modelling of class analogy. The results showed a high percentage of correct classification (99%) between the two species in the independent test. We found that the morphological distance between R. philippinarum and R. decussatus is higher than the morphological distance among populations of the same species. The absence of correspondence between the geographical location and the pattern of morphological and genetic variation indicates the occurrence of a reaction norm in the morphological adaptation of shell shapes to different local environmental conditions.We would like to thank Davide Cascione for his help during the process of image acquisition. Jacopo Aguzzi is a Fellow of the ‘Juan de la Cierva’ Postdoctoral Program (MECSpain).Peer reviewe
Paracrine inhibition of prion propagation by anti-PrP single-chain Fv miniantibodies.
No full textPrion diseases are characterized by the deposition of PrP(Sc), an abnormal form of the cellular prion protein PrP(C). A growing body of evidence suggests that antibodies to PrP(C) can antagonize deposition of PrP(Sc). However, host tolerance hampers the induction of immune responses to PrP(C), and cross-linking of PrP(C) by bivalent anti-PrP antibodies is neurotoxic. In order to obviate these problems, we explored the antiprion potential of recombinant single-chain antibody (scFv) fragments. scFv fragments derived from monoclonal anti-PrP antibody 6H4, flagged with c-myc and His6 tags, were correctly processed and secreted by mammalian RD-4 rhabdomyosarcoma cells. When cocultured with cells secreting anti-PrP scFv, chronically prion-infected neuroblastoma cells ceased to produce PrP(Sc), even if antibody-producing cells were physically separated from target cells in transwell cultures. Expression of scFv with irrelevant specificity, or of similarly tagged molecules, was not curative. Therefore, eukaryotically expressed scFv exerts a paracrine antiprion activity. The effector functions encoded by immunoglobulin constant domains are unnecessary for this effect. Because of their small size and their monovalent binding, scFv fragments may represent candidates for gene transfer-based immunotherapy of prion diseases
Propiedades termoterápicas y farmacotécnicas de formulaciones de peloides con excipientes hidrofílicos.
No full textOntogenetic and environmental effects on otolith shape variability in three Mediterranean European eel (Anguilla anguilla, L.) local stocks
No full text7 pages, 4 figures, 3 tablesOtolith morphology is an efficient tool for the discrimination of fish stocks, populations and species when comparative genetic data are not available. Currently, the relationship between environmental factors and otolith shape is poorly characterized for the European eel (Anguilla anguilla), a highly migratory catadromous species constituting a single, randomly mating stock. The present study analyses the differences in otolith morphology between three Mediterranean eel local stocks from different environmental contexts (i.e. two brackish lagoons and one river). The relationship between otolith shape and otolith size was studied by means of Elliptic Fourier analysis and multivariate statistics. Otolith profile was digitally acquired and Cartesian coordinates were extracted. Partial Least Square (PLS) analysis pointed to continuous allometric growth in size and shape in otoliths from all three sites. In the three environments, shape variations occurred during growth as indicated by the presence of a significant and positive relationship between otolith size and the first PLS latent vector (i.e. which bears most of the information regarding otolith outline). Differences between smaller and larger sized otoliths were investigated using PLS Discriminant Analysis (PLSDA) and cluster analysis. Results indicate that otolith shape is highly uniform at smaller than at larger sizes. These shape differences apparently overlap the initial differentiation of the small otolith outlines acquired by eels during the growing phase as elvers in the marine environment. Data were discussed considering that the physical and chemical habitat variability in brackish lagoons and river could underlie a marked change in otolith shape during the animals' growthThe present work was funded by a grant from the Ministry of Research and University to EC within the PRIN 2006 Project “An Integrated
Approach to the Conservation and Management of the European Eel in the Mediterranean Region” (Coordinator Prof. G. De Leo University of Parma); themorphological approach was developed within the framework of the project HIGHVISION (DM 19177/7303/03) to PM. The authors wish to thank the fishermen's associations of the river Tiber, Caprolace and Lesina for their help during samplings. Aguzzi J. is a Postdoctoral Fellow within the Ramon y Cajal Program (MICINN, España)Peer reviewe
Use of clays as drug delivery systems: possibilities and limitations
No full textThe need for safe, therapeutically effective and patient-compliant drug delivery systems continuously leads researchers to design novel tools and strategies. Clay minerals are widely used materials in drug products both as excipients and active agents. When administered simultaneously, drug–clay interactions have been observed and studied, but until recently were not considered as a possible mechanism to modify drug release. In recent years, and based on their high retention capacities as well as swelling and colloidal properties, clays have been proposed as very useful materials for modulating drug delivery. This paper first reviews the studies on drug–clay interactions, and then those focused on the applications of natural clays and their semi-synthetic or synthetic derivatives to carry out specific functions in new drug delivery systems. In particular, clays are used to delay and/or target drug release or even improve drug dissolution. Finally, new strategies are reported for increasing drug stability and simultaneously modifying drug delivery patterns through the use of clay minerals
Light-dependent genetic and phenotypic differences in the squat lobster Munida tenuimana (Crustacea: Decapoda) along deep continental margins
No full textSpecial issue Integrated study of a deep submarine canyon and adjacent open slopes in the Western Mediterranean Sea: an essential habitat.-- 11 pages, 7 figures, 4 tablesThe levels of environmental light experienced by organisms during the behavioral activity phase deeply influence the performance of important ecological tasks. As a result, their shape and coloring may experience a light-driven selection process via the day-night rhythmic behavior. In this study, we tested the phenotypic and genetic variability of the western Mediterranean squat lobster (Munida tenuimana). We sampled at depths with different photic conditions and potentially, different burrow emergence rhythms. We performed day-night hauling at different depths, above and below the twilight zone end (i.e., 700. m, 1200. m, 1350. m, and 1500. m), to portray the occurrence of any burrow emergence rhythmicity. Collected animals were screened for shape and size (by geometric morphometry), spectrum and color variation (by photometric analysis), as well as for sequence variation at the mitochondrial DNA gene encoding for the NADH dehydrogenase subunit I. We found that a weak genetic structuring and shape homogeneity occurred together with significant variations in size, with the smaller individuals living at the twilight zone inferior limit and the larger individuals above and below. The infra-red wavelengths of spectral reflectance varied significantly with depth while the blue-green ones were size-dependent and expressed in smaller animals, which has a very small spectral reflectance. The effects of solar and bioluminescence lighting are discussed as depth-dependent evolutionary forces likely influencing the behavioral rhythms and coloring of M. tenuimana. © 2013 Elsevier Ltd.The present work was developed within the framework of four Research Projects funded by the Spanish ‘‘Ministerio de Ciencia e Innovación’’ (MICINN): NERIT, RECS, PROMETEO, and DOS MARES, (with respective reference numbers: MAR/98/0935, REN02/04556/C02/MAR, CTM2007-66316-C02/MAR and CTM2010-21810-C03-03/MAR). Another contributing project was funded by the Italian Ministry of Agricultural, Food and Forestry Politics (MIPAF): High-Vision (DM 19177/7303/08). Jacopo Aguzzi is a Postdoctoral Fellow of the ‘‘Ramon y Cajal’’ Program (MICINN)Peer Reviewe
- …
