2,639 research outputs found
Il Simposio per immagini. Settimo Simposio Internazionale. Il monitoraggio costiero mediterraneo: problematiche e tecniche di misura
No full textIl volume è un appendice del VII Simposio "Il Monitoraggio Costiero Mediterraneo: problematiche e tecniche di misura" che si è tenuto a Livorno dal 19 al 21 giugno 2018. Nel volume, curato da Gianni Fasano e Matteo De Vincenzi, vengono illustrate le attività scientifico-culturali svolte in concomitate dell'Evento. Nel Volume sono presenti contributi di Paola Baldari,Fabrizio Benincasa, Fabio Berti Matteo De Vincenzi, Gianni Fasan
New mechanistic insight into replication fork reversal and restart
No full textAn emerging model of how stalled or damaged forks are processed is that replication
fork
s can reverse to aid repair of the damage. The first evidence that replication forks
regress in human cells came from a recent study with topoisomerase I (T
op
1) inhibitors, an
important class of anticancer drugs currently in clinical use. Their cytotoxicit
y, and thus
their efficacy, has been generally linked to their ability to cause the accumulation of DNA
nicks, which are later converted into double
-
stranded breaks (DSBs) by the collision of the
DNA replication fork with the primary lesion. The discovery
that replic
ation forks can
regress upon Top
1 inhibition provided new insight into
the molecular basis of Top
1
cytotoxicity by showing that clinically relevant
, nanomolar doses of Top
1 poisons induce
replication fork slowing and reversal in a process that c
an be uncoupled from DSB
formation
and
requires poly(ADP
-
ribose) polymerase
1
(
PARP1) activity.
However,
w
hether re
versed
forks can efficiently restart
and wh
ich
factors are
involved in this
mechanism
was
still unknown.
In this thesis
,
u
sing a combination
of biochemical and
cellular approaches, we provided the first evidence that regressed forks can restart
in vivo
and identified a key role for the human RECQ1 helicase in promoting efficient re
plication
fork restart after Top
1 inhibition
that is not shared
by other human RecQ
members
.
Our
data also provided the first insight into the molecular role of PARP1 in fork reversal by
showing that the poly(ADP
-
ribosyl)ation activity of PARP inhibits RECQ1 activity on
replication forks after Top 1 inhibition. Thus, PARP activity is not required to form, but
rather to "accumulate" reversed fork structures by maintaining/protecting them from a
counteracting activity (RECQ1), which would otherwise cause an untimely restart of
reversed forks, leading to DSB formation. The
identification of a specific and controlled
biochemical activity that drives
the
restart of reversed forks strongly supports the
physiological relevance of this DNA transaction during replication stress in human cells.
Moreover, our
studies provide new mec
hanistic insights into the roles of
RECQ1 and
PARP
1
in DNA replication and offer molecular perspectives to potentiate
chemo
therapeutic regimens based on Top
1 inhibition
Groundwater and ground displacement monitoring in the source area of the Montecchi earthflow (Northern Apennines, Italy)
No full textThe importance of pore water pressure regime for landslide activity is generally accepted. In the case of earthflows, generalized failures (reactivations) are rare and sustained slow movements can proceed for decades. The relationship between precipitation, pore water pressure responses and movement is not straightforward. We document rainfall, pore pressure regime and displacements in the source area of an active earthflow. Pressure heads at shallow depth are clearly related to infiltration from the surface and can be satisfactorily reproduced by a diffusive model while the hypothesis of gravity-dominated flow can be rejected based on the short delay between rainfall and pressure response. Displacement rates are very small to zero during the summer and increase a couple of months later than the onset of the precipitation of the wet season. Only late in the wet season, velocities attain peak values (up to 4 mm/day) and show a remarkable correlation to rainfall episodes. Higher displacement rates correspond to unexceptional pressure head values, we therefore believe that alternative mechanisms of water pressure build-up may exist. Fractures likely act as a preferential flow system and influence both the hydrological responses to rainfall and the deformation behavior of the landslide
Lithologic and morphologic controls on debris flow dynamics in the Dolomites (Italian Alps, Italy)
No full textIn high-relief landscapes, debris flows represent the most efficient mean of erosion and sediment transport across
spatial scales ranging from hectares to tens of square kilometers.
In the Dolomite region of Italy, the landscape is dominated by steep massifs mainly made of limestone and
dolostone rocks. Abundant talus and fan deposits connect the bottom of the valleys to the rocky massifs. Thick
debris talus was deposited in post-glacial climatic conditions and is actively fed by steep dolomitic rock walls.
Debris flows are widespread over the territory. They are commonly triggered by water discharge concentrated on
steep headwater catchments and delivered to talus slopes. Headwater catchments are typically very steep (45°-60°
on the average) and mostly consist of exposed bedrock with no vegetation and sparse to none soil cover. Debris
flow fans are relatively steep (10 to 30°)
Our study area extends over 250 km2 and includes about one-hundred debris flow catchments. We take advantage
of the remarkable morphological similarities of the catchments to characterize their lithology, morphometry and
investigate scale-relationships. We use LiDAR, field surveys and aerial photo interpretation to describe the
principal topographic conditions associated with debris-flow initiation, transportation, and deposition. Debris
flow-prone catchments associated to recent activity has been selected to investigate the role of geology and
morphology as influencing factor at basin scale. They display a decreasing specific sediment yield with increasing
size. Depending on the abundance of loose debris deposits, volumes of sediment delivered to the fan span about
one order of magnitude. Dependence of deposited sediment volumes on the basin scale is clear and translates into
an inverse proportionality when specific yield is considered
Atteso ma imprevedibile: il problema del dissesto idrogeologico in Italia
No full text[inizio del testo]: L’Italia è uno dei paesi europei più esposti al rischio frane. Secondo un recente studio del Joint Research Center della Commissione Europea (Van Den Eeckhaut and Hervas, 2012) i database nazionali e regionali di 22 stati membri contengono informazioni su oltre 630.000 fenomeni franosi. Di questi, il 75% si trova in Italia. Per gli addetti al settore questa non è una sorpresa. L’Italia è stato uno dei primi paesi a realizzare un censimento capillare delle frane e delle alluvioni a scala nazionale. Nel 1989 il Dipartimento di Protezione Civile commissionò al Consiglio Nazionale delle Ricerche il primo censimento delle aree del paese colpite da frane e alluvioni nell’ultimo secolo (Progetto AVI; CNR-GNDCI, 1994)..
Approaches of data analysis from multi‐parametric monitoring systems for landslide risk management
No full textIn the last decades, several approaches were proposed accounting for early warning
systems to manage in real time the risks due to fast slope failures where important
elements, such as structures, infrastructures and cultural heritage are exposed. The
challenge of these approaches is to forecast the slope evolution, thus providing alert
levels suitable for managing infrastructures in order to mitigate the landslide risk and
reduce the “response” time for interventions.
Three different strategies can be defined in this regard: an Observation‐Based
Approach (OBA), a Statistic‐Based Approach (SBA) and a Semi‐Empirical Approach
(SEA). These approaches are focused on searching relations among destabilizing
factors and induced strain effects on rock mass.
At this aim, some experiments are being performed at different scales in the
framework of consulting activities and research projects managed by the Research
Centre for the Geological Risk (CERI) of the University of Rome “Sapienza”. These
experiments are testing different kind of sensors including extensometers, strain
gauges, rock‐thermometers, interferometers, optical cams connected to Artificial
Intelligence (AI) systems, for detecting changes in rock properties and detecting stressstrain
changes, as well as pluviometers, anemometers, hygrometers, air‐thermometers,
micro‐ or nano‐ accelerometers and piezometers for detecting possible trigger of
deformational events.
The results of this Ph.D. thesis demonstrate that the data analysis methods allowed
the identification of destabilizing actions responsible for strain effects on rock mass at
different dimensional scale and over several time‐window, from short‐ to long‐ period
time scale. Furthermore, the three approaches were to be suitable to recognize
precursor signals of rock mass deformation and demonstrated the possibility to
provide an early warning
Air quality monitoring for pervasive health
No full textTwo monitoring projects relate to this issue's theme, "Hostile Environments": "Landslide Monitoring in the Emilia Romagna Apennines" and "Air Quality Monitoring for Pervasive Health." In addition, "Task-Driven Framework for Pervasive Computing" reports on TaskOS, a project to develop task-driven recommendation systems for pervasive computing environments.Science Foundation IrelandPart of Environmental Monitoring and Task-Driven Computing
Rosi, Alberto Bicocchi, Nicola Castelli, Gabriella Corsini, Alessandro Mamei, Marco Zambonelli, Franco Berti, Matteo Angove, Philip O'Flynn, Brendan Hayes, Jer Diamond, Dermot O'Grady, Michael J. O'Hare, Gregory M.P. Vo, Chuong C. Torabi, Torab Loke, Seng W. Page(s): 48 - 50 http://ieeexplore.ieee.org - AV 12/05/2011/xpls/abs_all.jsp?arnumber=558669
Uncertainty of debris flow mobility relationships and its influence on the prediction of inundated areas
No full textEmpirical mobility relationships can be used for delineating debris flow inundated areas. A database of
documented events in alpine mountain catchments of northeastern Italy is used to test the model DFlowz
(Berti and Simoni, 2007). We back-analyzed 25 DF events, ranging in volume from 3000 to 350,000 m3, with
the support of high resolution topographic information derived from LiDAR. The analysis makes use of an
objective methodology for evaluating the accuracy of the predictions and involves the calibration of the model
based on factors describing the uncertainty associated with the empirical relationships.
Results indicate that the model is capable of reproducing the observed behavior with amaximum uncertainty
of a factor of 3. The most relevant source of error lies in the estimation of the deposited volumes which affects
the results of back-calculation and is mainly responsible also for the scatter associated with the empirical
mobility relationships. On the contrary, the influence of different flow properties on the depositional process
appears to play a minor role as the mutual relations between the three main scaling parameters (volume,
inundated area, and cross-sectional area) are respected in the vast majority of cases and calibrated mobility
coefficients show no significant relationship with the angle of reach of the deposit
TUTELA DEL LAVORO E LIBERTA' D'IMPRESA NEI PROCESSI DI ESTERNALIZZAZIONE
No full textL’elaborato analizza le conseguenze lavoristiche della successione fra imprenditori, muovendo da una ricognizione delle varie tipologie di esternalizzazione con le relative esigenze e principali criticità.
L’indagine si concentra in primo luogo sul trasferimento d’azienda, esaminando la normativa e la giurisprudenza europee per passare poi alla disciplina di diritto interno, alle procedure sindacali e a uno specifico focus sul trasferimento delle aziende in crisi.
Successivamente l’autore si sofferma sull’appalto, prendendone in particolare considerazione gli indici di genuinità, i criteri di distinzione dalla somministrazione illecita di manodopera e la tutela delle maestranze in caso di avvicendamento fra imprese.
Da ultimo, la ricerca approfondisce le c.d. “clausole sociali”, sia di prima che di seconda generazione, valutandone la compatibilità con il diritto eurounitario e con la costituzione nonché riflettendo sui possibili rimedi in caso di loro violazione.The author analyzes the labour consequences of the succession between entrepreneurs, starting from a recognition of the various types of outsourcing with the related needs and main critical issues.
The survey focuses primarily on the transfer of businesses, examining European legislation and case-law and then moving on to internal legislation, trade union procedures and a specific focus on the transfer of companies in crisis.
The author then dwells on the contract, taking into account in particular the indications of authenticity, the criteria of distinction from the illicit administration of labour and the protection of workers in the event of turnover between companies.
Finally, the research deepens the "social clauses", both first and second generation, assessing their compatibility with European law and with the constitution and reflecting on possible remedies in case of their violation
Performance and reliability of empirical mobility relationships for the prediction of debris flow inundated areas.
No full textEmpirical mobility relationships can be used for preliminary DF Hazard assessment. An adaptation of the original relationships has been proposed for alpine debris flows (DFLOWZ model; Berti and Simoni, 2007). Once a reference debris flow volume is chosen, the code DFLOWZ allows to estimate the area potentially affected by the event based on the mutual relationships between channel cross-sectional area, planimetric area of the deposit and overall volume.
We back-analyzed 25 DF events occurred in the Bolzano province (Italy), ranging in volume from 3,000 to 300,000 m3 and evalutated the performance of the automated method through an objective reliability index. Our aim is:
- evaluate the effects of uncertainty associated with the empirical mobility relationships;
- assess other possible sources of error or violations of the assumptions that underlie the model.
Results indicate that a high-resolution DEM (≤ 2.5 m) is essential to get a reliable inundation prediction over a fan. The code itself performs well, in a wide range of situations, demonstrating the conceptual correctness of underlying assumptions. The most relevant source of error remains the uncertainty associated with the empirical mobility relationships, due mainly to errors in volume measurements of DF deposits. Their improvement can be achieved through the collection of high quality field data of DF events
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