1,215 research outputs found
Variation in Environmental Parameters in Research and Aquaculture: Effects on Behaviour, Physiology and Cell Biology of Teleost Fish
Over the last few years the increasing use of fish as animal models in scientific research and the increased fish breeding for human consumption have stressed the need for more knowledge on the effect of variations in environmental parameters on fish biology and on the welfare of specimens used both in research and aquaculture contexts. Experimental evidence shows that environmental variations can affect fish biology at various levels, from the molecular to that of the population, sometimes in a different way depending on the species considered. In order to achieve reproducible results in experiments involving fish it is necessary to set and maintain all environmental parameters constant at the optimal value to guarantee the wellness of the animal. The effects of the variation in environmental parameters on the behaviour, physiology and cell biology of teleosts are here discussed in order to provide useful information for research based on fish models
Unexpected effect of Ru-substitution in lightly doped manganites
In this Communication we report about the unexpected effect of ruthenium
doping in sodium ligthly-doped manganites. This effect seems to be in contrast
with the usual model applied to describe the effect of this magnetic ion into
the manganite structure. We propose a possible compensation mechanism which
seems also able to describe other peculiar features encountered in these
materials.Comment: 3 pages, 2 Figures to appear in ChemCom
High Pressure X-ray Diffraction Study of MgMn2O4 Tetragonal Spinel
The phase stability of the MgMn2O4 spinel has been studied by means of
high-pressure X-ray diffraction for pressures up to 30 GPa. Two samples with
different inversion degrees have been considered. Both spinels undergo a phase
transition towards an orthorhombic structure (CaMn2O4-type). For the more
inverted sample the transition pressure is at least 1 GPa lower with respect to
that of the less inverted spinel. Also the volume contraction, relative
compressibility and density trends are different for the two samples. These
variations have been explained according to differences in the cation
distribution. and electronic properties of the samples.Comment: 12 pages; 4 Figures presented at the SRMS-
Consistent Image Decoding from Multiple Lossy Versions
With the recent development of tools for data sharing in social networks and peer to peer networks, the same information is often stored in different nodes. Peer-to-peer protocols usually allow one user to collect portions of the same file from different nodes in the network, substantially improving the rate at which data are received by the end user. In some cases, however, the same multimedia document is available in different lossy versions on the network nodes. In such situations, one may be interested in collecting all available versions of the same document and jointly decoding them to obtain a better reconstruction of the original. In this paper we study some methods to jointly decode different versions of the same image. We compare different uses of the method of Projections Onto Convex Sets (POCS) with some Convex Optimization techniques in order to reconstruct an image for which JPEG and JPEG2000 lossy versions are available
An analysis method of the vortex-induced vibrations of a tethered sphere
Vortex-induced vibrations (VIV) in systems with more than one degree of freedom often present complex synchronization among the motion components, also hidden by the randomness that characterizes the motion itself. A phase average method has been here developed and applied to the displacements of a tethered sphere, at low mass and damping, to analyze its xy trajectories over a wide range of reduced velocities, 5 ≤ U* ≤ 25 (Reynolds numbers, 5.1 × 103 ≤ Re ≤ 2.67 × 104). This method has allowed the identification of both the periodic and chaotic contribution of each motion component, accurately reconstructing the underlying trajectory periodic pattern. The two classical vibration modes, I and II, have been also observed. The method developed here was able to better rebuild the experimental data compared to other methods found in the relevant literature, providing useful insights into the study of the dynamic response of a freely-oscillating tethered sphere immersed in a steady flow
Il "politico cattedrante": Paolo Paruta teorico dell'oligarchia illuminata e gli scritti di Traiano Boccalini
Evidence of a pressure-induced metallization process in monoclinic VO
Raman and combined trasmission and reflectivity mid infrared measurements
have been carried out on monoclinic VO at room temperature over the 0-19
GPa and 0-14 GPa pressure ranges, respectively. The pressure dependence
obtained for both lattice dynamics and optical gap shows a remarkable stability
of the system up to P*10 GPa. Evidence of subtle modifications of V ion
arrangements within the monoclinic lattice together with the onset of a
metallization process via band gap filling are observed for PP*. Differently
from ambient pressure, where the VO metal phase is found only in
conjunction with the rutile structure above 340 K, a new room temperature
metallic phase coupled to a monoclinic structure appears accessible in the high
pressure regime, thus opening to new important queries on the physics of
VO.Comment: 5 pages, 3 figure
Quasiparticle evolution and pseudogap formation in V2O3: An infrared spectroscopy study
The infrared conductivity of V2O3 is measured in the whole phase diagram.
Quasiparticles appear above the Neel temperature TN and eventually disappear
further enhancing the temperature, leading to a pseudogap in the optical
spectrum above 425 K. Our calculations demonstrate that this loss of coherence
can be explained only if the temperature dependence of lattice parameters is
considered. V2O3 is therefore effectively driven from the metallic to the
insulating side of the Mott transition as the temperature is increased.Comment: 5 pages, 3 figure
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