102 research outputs found
Cloning of mouse integrin alphaV cDNA and role of the alphaV-related matrix receptors in metanephric development.
Metanephrogenesis has been a long-standing model to study cell-matrix interactions. A number of adhesion molecules, including matrix receptors (i.e., integrins), are believed to be involved in such interactions. The integrins contain alpha and beta s ubunits and are present in various tissues in different heterodimeric forms. In this study, one of the members of the integrin superfamily, alphaV, was characterized, and its relevance in murine nephrogenesis was investigated. Mouse embryonic renal cDNA libraries were prepared and screened for alphaV, and multiple clones were isolated and sequenced. The deduced amino acid sequence of the alpha-v cDNA clones and hydropathic analysis revealed that it has a typical signal sequence and extracellular, transmembrane, and cytoplasmic domains, with multiple Ca2+ binding sites. No A(U)nA mRNA instability motifs were present. Conformational analysis revealed no rigid long-range-ordered structure in murine alphaV. The alphaV was expressed in the embryonic kidney at day 13 of the gestation, with a transcript size of approximately 7 kb. Its expression increased progressively during the later gestational stages and in the neonatal period. It was distributed in the epithelial elements of developing nephrons and was absent in the uninduced mesenchyme. In mature metanephroi, the expression was relatively high in the glomeruli and blood vessels, as compared to the tubules. Various heterodimeric associations of alphaV, i.e., with beta1, beta3, beta5, and beta6, were observed in metanephric tissues. Inclusion of alphaV-antisense-oligodeoxynucleotide or -antibody in metanephric culture induced dysmorphogenesis of the kidney with reduced population of the nephrons, disorganization of the ureteric bud branches, and reduction of mRNA and protein expressions of alphaV. The expressions of integrin beta3, beta5, and beta6 were unaltered. These findings suggest that the integrin alphaV is developmentally regulated, has a distinct spatio-temporal expression, and is relevant in the mammalian organogenesis
From bottom landers to observatory networks
For a long time, deep-sea investigation relied on autonomous bottom landers. Landers can vary in size from 200 kg
weight to more than 2 t for the heaviest scientific landers and are used during exploration cruises on medium periods,
from one week to some months. Today, new requirements appear. Scientists want to understand in detail the phenomena
outlined during exploration cruises, to elaborate a model for future forecasting. For this, it is necessary to deploy
instrumentation at a precise location often for a long period. A new mode of ocean science investigation using longterm
seafloor observatories to obtain four dimensional data sets has appeared. Although this concept has been proposed
for many years, the high level of investment required limits the number of projects implemented. Only multidisciplinary
programs, supported by a strong social requirement were funded. Some observatories have been deployed
European Seafloor Observatory Offers New Possibilities For Deep Sea Study
The Geophysical and Oceanographic Station for Abyssal Research (GEOSTAR), an autonomous seafloor observatory that collects measurements benefiting a number of disciplines during missions up to 1 year long, will begin the second phase of its first mission in 2000. The 6-8 month investigation will take place at a depth of 3400 m in the southern Tyrrhenian basin of the southern Tyrrhenian basin of the central Mediterranean.
GEOSTAR was funded by the European Community (EC) for 2 million (US dollars), will carry equipment for chemical, biological and isotopic analyses not used in the first phase, which will broaden the data collection effort.Published45, 48-492.5. Laboratorio per lo sviluppo di sistemi di rilevamento sottomariniN/A or not JCRreserve
Single-frame multiparameter platforms for seafloor geophysical and environmental observations: projects and missons from GEOSTAR to ORION
The paper presents an overview of recent seafloor long-term single-frame multiparameter platform developed in the framework of the European Commission and Italian projects starting from the GEOSTAR prototype. The main features of the different systems are described as well as the sea missions that led to their validation. The ORION seafloor observatory network recently developed, based on the GEOSTAR-type platforms and engaged in a deep-sea mission at 3300 m w.d. in the Mediterranean Sea, is also describe
A fleet of multiparameter observatories for geophysical and environmental monitoring at seafloor
Seafloor long-term, multiparameter, single-frame observatories have been developed within the framework of European Commission and Italian projects since 1995. A fleet of five seafloor observatories, built-up starting from 1995 within the framework of an effective synergy among research institutes and industries, have carried out a series of long-term sea experiments. The observatories are able to operate from shallow waters to deep sea, down to 4,000 m w.d., and to simultaneously monitor a broad spectrum of geophysical and environmental processes, including seismicity, geomagnetic field variations, water temperature, pressure, salinity, chemistry, currents, and gas occurrence. Moreover, they can transmit data in (near)-real-time that can be integrated with those of the on-land networks. The architecture of the seafloor observatories follows the criteria of modularity, interoperability and standardisation in terms of materials, components and communication protocols. This paper describes the technical features of the observatories, their experiments and data
Detection potential of the KM3NeT detector for high-energy neutrinos from the Fermi bubbles
A recent analysis of the Fermi Large Area Telescope data provided evidence for a high-intensity emission of high-energy gamma rays with a E 2 spectrum from two large areas, spanning 50 above and below the
Galactic centre (the ‘‘Fermi bubbles’’). A hadronic mechanism was proposed for this gamma-ray emission making the Fermi bubbles promising source candidates of high-energy neutrino emission. In this work Monte Carlo simulations regarding the detectability of high-energy neutrinos from the Fermi bubbles
with the future multi-km3 neutrino telescope KM3NeT in the Mediterranean Sea are presented. Under the hypothesis that the gamma-ray emission is completely due to hadronic processes, the results indicate
that neutrinos from the bubbles could be discovered in about one year of operation, for a neutrino spectrum with a cutoff at 100 TeV and a detector with about 6 km3 of instrumented volume. The effect of a
possible lower cutoff is also considered.Published7–141.8. Osservazioni di geofisica ambientaleJCR Journalrestricte
Expansion cone for the 3-inch PMTs of the KM3NeT optical modules
[EN] Detection of high-energy neutrinos from distant astrophysical sources will open a new window on the Universe. The detection principle exploits the measurement of Cherenkov light emitted by charged particles resulting from neutrino interactions in the matter containing the telescope. A novel multi-PMT digital optical module (DOM) was developed to contain 31 3-inch photomultiplier tubes (PMTs). In order to maximize the detector sensitivity, each PMT will be surrounded by an expansion cone which collects photons that would otherwise miss the photocathode. Results for various angles of incidence with respect to the PMT surface indicate an increase in collection efficiency by 30% on average for angles up to 45 degrees with respect to the perpendicular. Ray-tracing calculations could reproduce the measurements, allowing to estimate an increase in the overall photocathode sensitivity, integrated over all angles of incidence, by 27% (for a single PMT). Prototype DOMs, being built by the KM3NeT consortium, will be equipped with these expansion cones.This work is supported through the EU, FP6 Contract no. 011937, FP7 grant agreement no. 212252, and the Dutch Ministry of Education, Culture and Science.Adrián MartÃnez, S.; Ageron, M.; Aguilar, JA.; Aharonian, F.; Aiello, S.; Albert, A.; Alexandri, M.... (2013). Expansion cone for the 3-inch PMTs of the KM3NeT optical modules. Journal of Instrumentation. 8(3):1-19. https://doi.org/10.1088/1748-0221/8/03/T03006S1198
[Pool and addition order of ribosomal proteins in biogenesis of E. coli ribosomes]
International audiencexx
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