1,106 research outputs found
Navigatori e prevenzione degli incidenti
Un ausilio sonoro che indichi al conducente la presenza dei segnali di “dare precedenza” potrebbe rappresentare un valido supporto nell’ambito della sicurezza stradal
Seasonal changes in morpho-functional aspects of two Anemonia sulcata (Pennant, 1777) wild populations
Marine benthic organisms can be used as indicators of the quality of environmental status and as monitoring tools to detect natural or anthropogenic perturbations. In temperate waters, metabolic and biochemical responses may be governed by physiological changes driven by seasonal factors. Gathering baseline information on the mechanisms underlying seasonal acclimation patterns is therefore a critical step towards the understanding of the physiological responses of biological indicators. In poikilothermic metazoans, the production of regulatory metabolic enzymes can be used as tools for deciphering the acclimation potential. The aim of this study was to characterize the natural seasonal variability in biometric traits and enzymatic biomarkers over a 12-month period in the sea anemone, Anemonia sulcata (Anthozoa, Cnidaria), from two areas with different environmental and anthropic impacts. Seasonality and site factors affected enzymatic kinetics at tentacle levels, while seasonality, site and biometrical characteristics modulated the same enzymes in the body column of A. sulcata. The results showed a decrease in enzymatic activity in summer and an increased synthesis of enzymes in the late fall and winter months. The interaction between biometric features and temperature appeared significant for mesolittoral sea anemones but not for infralittoral specimens. This study showed seasonal patterns of variations of biochemical responses in A. sulcata, suggesting that this species, an abundant member of shallow rocky bottom communities in temperate European seas, may represent a sensitive bio-indicator organism worth considering for further ecological studies on climate change as well as for environmental monitoring programs
Molecular characterisation, evolution and expression analysis of g-type lysozymes in Ciona intestinalis
Lysozyme is an important defense molecule of the innate immune system. Known for its bactericidal
properties, lysozyme catalyzes the hydrolysis of b-(1,4)-glycosidic bonds between the N-acetyl glucosamine
and N-acetyl muramic acid in the peptidoglycan layer of bacterial cell walls. In this study, the
complete coding sequence of four g-type lysozymes were identified in Ciona intestinalis. Phylogenetic
analysis and modelling supported the hypothesis of a close relationship with the vertebrate g-type lysozymes
suggesting that the C. intestinalis g-type lysozyme genes (CiLys-g1, Cilys-g2, CiLys-g3, CiLys-g4)
share a common ancestor in the chordate lineage. Protein motif searches indicated that C. intestinalis gtype
lysozymes contain a GEWL domain with a GXXQ signature, typical of goose lysozymes. Quantitative
Real-Time PCR analysis results showed that transcripts are expressed in various tissues from
C. intestinalis. In order to determine the involvement of C. intestinalis g-type lysozymes in immunity, their
expression was analyzed in the pharynx, showing that transcripts were significantly up-regulated in
response to a challenge with lipopolysaccharide (LPS). These data support the view that CiLys g-type are
molecules with potential for immune defense system against bacterial infection
Ciona intestinalis galectin (CiLgals-a and CiLgals-b) genes are differentially expressed in endostyle zones and challenged by LPS
Immunohistochemical and in situ hybridization assays were performed to answer the question whether
the endostyle, that is the initial gastro-intestinal trait of Ciona intestinalis pharynx, is involved in galectin
(CiLgals-a and CiLgals-b) production during the pharynx inflammatory response to LPS inoculation.
Specific anti-CiLgal-a and anti-CiLgals-b antibodies, and oligonucleotide probes, that mark inflammatory
hemocytes inside the pharynx vessels and vessel epithelium as shown by a previous paper, were assayed
on endostyle histological sections. For the first time, we show that galectins are produced by endostyle
zones, and both CiLgals-a and eb genes are upregulated by LPS. CiLgals-a and CiLgals-b are constitutively
expressed in the endostyle zone 2 and 3, respectively, both genes are upregulated by LPS in the zone 2,
and CiLgals-b in the zone 3 and 4. The antibody-reacting material contained in intracellular and extracellular
large vesicles suggest an unexpected vesicle-dependent transporting mechanism of galectins not
provided with signal peptide. Differential expression and gene upregulation in not-treated and LPStreated
specimens, support the role of endostyle galectins both in filter feeding and defense responses
Experimental determination of the quasi-projectile mass with measured neutrons
The investigation of the isospin dependence of multifragmentation reactions
relies on precise reconstruction of the fragmenting source. The criteria used
to assign free emitted neutrons, detected with the TAMU Neutron Ball, to the
quasi-projectile source are investigated in the framework of two different
simulation codes. Overall and source-specific detection efficiencies for
multifragmentation events are found to be model independent. The equivalence of
the two different methods used to assign experimentally detected charged
particles and neutrons to the emitting source is shown. The method used
experimentally to determine quasi-projectile emitted free neutron multiplicity
is found to be reasonably accurate and sufficiently precise as to allow for the
study of well-defined quasi-projectile sources.Comment: 10 pages, 8 figures. To be submitted to Nucl. Instr. and Meth.
Novel technique to extract experimental symmetry free energy information of nuclear matter
A new method of accessing information on the symmetry free energy from yields
of fragments produced in Fermi-energy heavy-ion collisions is proposed.
Furthermore, by means of quantum fluctuation analysis techniques, correlations
between extracted symmetry free-energy coefficients with temperature and
density were studied. The obtained results are consistent with those of
commonly used isoscaling techniques.Comment: 6 pages, 3 figures Heavy-ion nuclear reactions at Fermi energies,
Nuclear equation of State, Fragmentatio
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