544 research outputs found
"Con un remo in liogo de penelo": la regata di Marco Boschini
No full textViene illustrato il poemetto di Marco Boschini scritto in occasione della regata indetta dalla Serenissima in onore di Cortizzos di Calatrava (1670). Il testo illumina alcuni momenti della vita e dell'opera dell'autore della "Carta del navigar pitoresco"
Expression of the 70 kDa Heat shock protein family in Alpine freshwater chironomids (Diptera, Chironomidae) under natural conditions
No full textChironomidae represent up to 100% of the fauna of Alpine streams. Because they survive stress conditions such as extremely lowtemperature (annual mean cold and expression of stress proteins such as the 70 kDa Heat shock protein family. Fourth instar larvae of ten species of coldstenothermalchironomids (Pseudodiamesa branickii, Diamesa latitarsis, D. laticauda, D. cinerella, D. insignipes, D. zernyi, D.vaillanti, Orthocladius (O.) frigidus, O. (Euorthocladius) thienemanni and Paratrichocladius nivalis) were collected in a glacier-fedstream in NE Italy at two stations (1300 and 2600 m a.s.l.) and in two seasons (summer 2005 and spring 2006). Immunodetectionand quantification of the relative levels of Hsp70 family were performed via Western blot analysis. Significantly different levels ofHsp70 were detected among species. The highest amounts were recorded in P. nivalis and D. insignipes, the lowest in P. branickii.Within the genus Diamesa, lower levels of Hsp70 were observed in the most cold-stenothermal species than in the less coldstenothermalones. These differences may be explained by different species autoecology. The results provide information onbiochemical strategies of alpine midges to face cold temperatures under natural conditions and new insights into their possibleresponse to global warming
Encystment processes and the Matrioshka-like stage in a moss-dwelling and in a limnic species of eutardigrades (Tardigrada)
No full textTardigrades have two forms of dormancy, namely cryptobiosis and encystment. The encystment is a form of diapause known for a limited number of species of tardigrades and still little studied. To increase the knowledge on encystment, two species of eutardigrades from Italy have been considered: the moss-dwelling Amphibolus volubilis (Eohypsibiidae), and the limnic Dactylobiotus parthenogeneticus (Murrayidae). Cysts have been collected in nature, or induced under laboratory conditions. In the latter case, it was possible to follow the several steps of encystment processes. Two different types of cyst (type 1 and type 2) have been found in A. volubilis, while in D. parthenogeneticus only one type has been found. In general, the ovoid-shaped cysts are constituted by a series of cuticles surrounding the animals and resemble an onion or a Matrioshka Russian doll. In all three types of cyst, the encystment processes show both common and peculiar traits. Encystment begins with the discharging of the sclerified parts of the buccal-pharyngeal apparatus, as in the molting process, but without the loss of the old cuticle. Then, two or three new cuticles are serially synthesized, according to cyst type. In A. volubilis, the ultrastructure of these new cuticular involucra is similar to that of non-encysted animal cuticles, while in D. parthenogeneticus the ultrastructure of the new cuticular involucra differs from that of non-encysted animal cuticle. A modified buccal-pharyngeal apparatus has been observed both in type 2 cyst of A. volubilis and in the D. parthenogeneticus cyst
Preparazioni coronali totali e parziali dei settori posteriori: valutazione della quantità di tessuti duri asportati
No full textHeat shock proteins in encysted and anhydrobiotic eutardigrades
No full textHeat shock proteins (Hsps) can help organisms to survive environmental stresses. Tardigrades are aquatic metazoans able to colonize unpredictable, or “hostile to life”, terrestrial habitats entering resting stages such as cysts and anhydrobiotic tuns. In this paper we compared the Hsp70 and Hsp90 expression between resting stages (tuns or cysts) and active hydrated specimens of two eutardigrade species, namely Bertolanius volubilis and Ramazzottius oberhaeuseri. The two species partly differ in the kind of dormant stages utilized and in habitats colonized. In both species desiccation stress did not induce an up-regulation of either Hsps. Our data, together with those from literature, suggest that in tardigrades Hsps are involved in repairing molecular damages after anhydrobiosis, rather than in the stabilization of molecules during the dry state. Finally, the first demonstration of the presence of Hsps in diapausing cysts of B. volubilis are reported and discussed
Natural risk management for industrial plants and infrastructures: the DaBo system
No full textNatural risk management on complex critical infrastructures often requires integration of data coming out from
a huge number of sensors. Solutions are sometimes derived by classical supervisory control and data acquisition
systems (SCADAs), usually employed in manufacturing and industrial plants environment. This “control room”
approach often proves to be ineffective when the system to be monitored goes beyond the limits of the single plant
and it is extended to the surrounding environment including buildings and public infrastructures in a strong interaction
with local communities. The paper presents the case study of a hydroelectric plant extended over a territory
of a few tens of square kilometers and subject to hydrogeological problems of various kinds, with interactions
with buildings and infrastructures. The huge number of sensors installed for production control proved to be far
to monitor the safety of the plant in its environmental context. We present here the risk assessment procedure and
the proposed actions, also in terms of sensor installation. DaBo platform work as a data integrator. The structural
and hydraulic “ordinary state” is continuously generated by means of numerical modeling basing upon real time
observed boundary conditions. This state, via a suitable set of state variables, is compared with sensor data allowing
a clear synthesis of the safety of the infrastructure and its natural and anthropic context. DaBo poses itself as
a systems integrator both from a conceptual and an operational point of view, able to activate direct measures to
reduce the risk in case of emergency, involving also local civil protection authorities.
The platform integrates information from a wide range of sensors (viz. temperature, water level, strain, water content),
weather alerts, weather forecast from high resolution limited area models. The main innovation of DaBo
consists in the dashboard designed to provide communication of risk to the end user and to link the warnings to
action procedures. It is technically a responsive single page web application that is based on an information storage
and management layer by a high capacity relational database, a powerful scalable business logic tier for decision
support and early warning system, and a multi profiled responsive user interface. The goal is to ensure the operation
of the entire supply chain that connects the various sources of information to the entire user range
Diapause in tardigrades: a study of factors involved in encystment
No full textStressful environmental conditions limit survival, growth, and reproduction, or these conditions induce resting stages indicated as dormancy. Tardigrades represent one of the few animal phyla able to perform both forms of dormancy: quiescence and diapause. Different forms of cryptobiosis (quiescence) are widespread and studied, while little attention has been devoted to adaptive meaning of the encystment (diapause). Our goal was to determine environmental factors and token stimuli involved in the encystment process of tardigrades. The eutardigrade, Amphibolus volubilis, a species able to produce two types of cysts (type 1 and type 2), has been considered. Laboratory experiments and long-term study on cyst dynamics of a natural population were conducted. Laboratory experiments demonstrate that active tardigrades collected in April produced mainly type 2 cysts, whereas animals collected in November produced mainly type 1 cysts, indicating that the different responses are functions of the physiological state at the time they were collected. Dynamics of the two types of cyst show opposite seasonal trends: type 2 cysts are present only during the warm season and type 1 cysts, present during the cold season. Temperature represents the environmental factor involved in induction, maintenance, and termination of the cyst. We also evidenced that A. volubilis is able to perform both diapause and cryptobiosis, even overlapping the two phenomena. The induction phase of tardigrade encystment can be compared to the induction phase of insect diapause, also indicating an involvement of endogenous factors in tardigrade encystment. As in insect diapause, tardigrade encystment can be considered a diapausing state controlled by exogenous and endogenous stimuli
Progressive and efficient verification for digital signatures: extensions and experimental results
No full textISSN:2190-8508ISSN:2190-8516ISSN:2190-851
Thermal tolerance and expression of Hsp70 in larvae of Diamesa spp.
No full textAir temperature and precipitation patterns are likely to change under a scenario of global climate warming, with consequent effects on water temperature and hydrology of running waters, especially of those fed by glaciers. Invertebrates living in these habitats (mainly Chironomidae Diamesinae) are extremely specialised and have developed unique survival strategies to face environmental constraints. The ability to survive heat-shocks was investigated in cold stenothermal species, threatened of extinction by global warming. IV instar larvae of Diamesa cinerella gr. were collected seasonally (from March 2005 to March 2006) in the Noce river (Trentino, NE Italy) at two altitudes (1300 and 2600 m a.s.l.). Larvae were acclimated in a thermostatic chamber for 24 h at 4°C and then exposed for 1 h to heat-shocks from 26 to 35°C. Survival was recorded 1 h after the shock and thermal tolerance was evaluated as LT50. D. cinerella gr. resulted thermotolerant (LT50 varied from 30.1 to 32.9°C). Hsp70 were detected and quantified both in heat-shocked and un-shocked larvae of D. cinerella gr and in un-shocked larvae of other Diamesa species by means of SDS-Page and immunoblotting. An increase of Hsp70 expression was detected in shocked larvae of D. cinerella gr. collected in summer. Constitutive stress proteins were found in all species maintained at 4°C. This could explain the high resistance to brief heat-shocks found in D. cinerella gr
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