1,356,308 research outputs found
A novel approach to sparse histogram image lossless compression using JPEG
Full text linkIn this paper a novel approach to the compression of sparse histogram images is proposed. First, we define a sparsity index which gives hints on the relationship between the mathematical concept of matrix sparsity and the visual information of pixel distribution. We use this index to better understand the scope of our approach and its preferred field of applicability, and to evaluate the performance. We present two algorithms which modify one of the coding steps of the JPEG2000 standard for lossless image compression. A theoretical study of the gain referring to the standard is given. Experimental results on well standardized images of the literature confirm the expectations, especially for high sparse images
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
Frequency optimization of video-transect imaging routines with the Internet Operated Vehicle "Wally" in a deep cold-seep (Barkley Canyon, BC, Canada)
No full textTrabajo final presentado por Alejandro Suárez Avendaño para un Máster de la Universitat de Barcelona (UB), realizado bajo la dirección del Dr. Jacopo Aguzzi del Institut de Ciències del Mar (ICM-CSIC
A case of complete albinism in Lissotriton vulgaris meridionalis
Full text linkNew case of albinism in a Lisootriton vulgaris. The first record for L. vulgaris. meridionalis
Stratigraphic architecture of Late Quaternary deposits in the Lower Arno Plain (Tuscany, Italy)
No full textDetailed sedimentological investigation of two continuously-cored boreholes, up to 106 m deep,
combined with stratigraphic analysis of about 300 well logs performed for water research in the area between
Cascina and the Tyrrhenian coast, reveal subsurface stratigraphy of Late Quaternary deposits in the lower Arno
Plain.
Facies analysis of the cores allows identification of twelve different facies associations, grouped into alluvial
and coastal depositional systems. A stratigraphic cross section, roughly parallel to present Arno River and 30 km
long, shows the presence of two trangressive-regressive sequences, attributed to the last two interglacial-glacial
cycles (base of OIS 1 and 5e, respectively). Despite significant facies variability from proximal to distal locations,
the basal transgressive surfaces appear as the most readily identifiable features from both core and borehole data,
and constitute a stratigraphic marker that can be physically traced across the entire study area.
The high resolution stratigraphic data shown in this paper are in marked contrast with previous work, and provide
a new stratigraphic framework for the upper portion of the Viareggio Basin
Characterization of aquifer systems from high-resolution subsurface stratigraphy: the case of the eastern Valdarno basin (Tuscany, Italy)
No full textRealistic models of ground water circulation and transport in modern alluvial
and coastal plains demand an accurate reconstruction of subsurface
sedimentary architecture. In this study, we propose the characterization of a
multilayered aquifer from the subsiding eastern Valdarno Basin, a strategic
area far both water research and pollution issues, between the city of
Pontedera and S. Croce.
An integrated sedimentological, stratigraphic and micropaleontological study of
six continuously cored boreholes allows the detailed reconstruction of Pliocene
to Quaternary stratigraphy in the uppermost 100 m, and shows how a
multidisciplinary approach may represent a successful tool to define
three-dimensional facies relationships with in sedimentary bodies, and thus
aquifer geometries. Moreover, AMS 14C dates associated to Sr isotope data
prompt to place the identified stratigraphic units in a worthy
chronostratigraphic framework, with a coherent depositional evolution in terms
of space and time.
The study area, oriented SW-NE along the Arno River course, is rimmed to the
south and to the north by the Pisa and the Cerbaie Hills, respectively, both
formed by Plio-Quaternary marine and continental deposits. A fault, located
a long the southern margin of the Cerbaie Hills, causes the NNW-dipping, below
the Arno-plain, of the Plio-Quaternary deposits cropping out o n the Pisa Hills.
Stratigraphic architecture in the study area is varied. Except far the Holocene
succession, consisting mainly of fine-grained alluvial-plain deposits lying onto
transgressive swamp deposits and showing a homogenous spatial distribution,
the pre-Holocene deposits exhibit noticeable distinct features west and east of
Pontedera, respectively, due to the activity of a normal fault with an Apenninic
orientation, causing the lowering of the west side of the study area. A thick
Pleistocene alluvial succession, made up by a cyclic alternation of
coarse-grained fluvial channel and fine-grained floodplain deposits, is recorded
beneath Pontedera, whereas eastwards the stratigraphic sequence is
characterized by Early-Middle Pliocene deposits, related to coastal-shallow
marine sands with very subordinate alluvial facies.
Given this structural setting, the reconstruction of stratigraphic architecture
leads to the identification, in the uppermost 100 m, of a multilayered confined
aquifer consisting of five aquifer systems (A-E) ranging in age between the
Holocene and the Early-Middle Pliocene.
Aquifer system A developed during the Holocene and exhibits a markedly
lenticular geometry recording the recent dynamics of the Arno River. The
underlying aquifer system (B), Lower-Middle Pleistocene-Holocene in age,
consists of sands an d gravels of fluvial origin and is recorded only in the
western sector of the examined area. The lower three aquifer systems (C-D-E),
characterizing the eastern sector of the study area, mainly consist of sandy
shallow-marine deposits, Early to Middle Pliocene in age, showing a cyclic
arrangement.
The Quaternary aquifer systems (A-B) exhibit a strongly lenticular shape,
reflecting their fluvial origin, while the Early-Middle Pliocene aquifer systems
(C-D-E) display a higher lateral continuity, as expected from sedimentary
bodies deposited in coastal-littoral setting.
The geological framework and the structural setting suggest the identification
of water recharge areas in the Middle Pliocene sandy deposits cropping out on
the Pisa Hills, taking into account their NNW dipping toward the Arno Plain
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
Full text link7 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
Industrial Design and Aerospace: A Methodological Prespective
No full textThe new targets of human exploration (Moon and Mars) involve the extention of mission duration time. to face the long-term exploration a deeper investigation on issues related to human beings and hability in space is required. These issues entail that engineering disciplines will be integrated into multidisciplinary teams. This raises the problem of the definition of an interdisciplinary porcess, that can allow people from diferent disciplines (biologists, psychologiss, architects, designers, geologists...) to work together to achieve the same goal.
This paper presents a description of aerospace engineering and industrial designapproches in order to find possibilities of integration into an interdisciplinary design process. The methodology currently used in aerospace field for design of systems and elements will be described ad compared to the approach conventionally used by industrial designers in non-aerospace applications
Preparation of interstratified compounds by intercalation and in situ polymerization of acrylate anions into the galleries of layered double hydroxides.
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