1,240 research outputs found
Value creation strategies in credence food productions. The case of organic farming in Italy
In this paper we analyse different strategies used by Italian organic farmers to create value from credence food production. More specifically, we consider the following strategies: participation in policy support programmes (i.e. rural development measures and agro-environmental schemes), direct marketing (i.e. short-chains, on-farm businesses, agro-tourism), on-farm processing and being a member of a marketing and/or processing cooperative. We use data from the 2006 Italian FADN (Farm Accountancy Data Network) related to 981 organic farmers. To estimate the factors affecting farmers’ strategies and to evaluate them simultaneously we implement a multivariate probit model (MVP). The results could be helpful to implement guidelines for public and private intervention in the next CAP programming period. Allowing for differences in farmers’ goals and their impact on the choice of farming method and strategies is important in a modern competitive scenario
Factors Affecting Participation of Italian Farmers in Rural Development Policy
In this paper a (micro)econometric approach is developed by considering the farmer likelihood to participate in different policy programs as linked to the objective of farmer to maximize their welfare. In this way we model farmers participation in policy support scheme by using a new institutional economics approach and conceptualizing the decision to entry as a contractual choice between two rural development types of policy. Different discrete choice modelling approaches are used to analyze the complementarity/ substitutability of different policy programs such as environmental-related measures and farm investment supports policy schemes and the main driving factors behind them. We use an extensive cross-sectional database related to the Italian FADN 2006. Results indicate that social capital and institutional factors should be taken much more into account in order to understand farmers likelihood to entry in policy support schemes. Location and farm(er) socio-economic features are also relevant factors. Moreover complementarity has been found between different policy schemes
Missing hard states and regular outbursts: the puzzling case of the black hole candidate 4U 1630-472
4U 1630-472 is a recurrent X-ray transient classified as a black-hole
candidate from its spectral and timing properties. One of the peculiarities of
this source is the presence of regular outbursts with a recurrence period
between 600 and 730 d that has been observed since the discovery of the source
in 1969. We report on a comparative study on the spectral and timing behaviour
of three consecutive outbursts occurred in 2006, 2008 and 2010. We analysed all
the data collected by the INTErnational Gamma-Ray Astrophysics Laboratory
(INTEGRAL) and the Rossi X-ray timing Explorer (RXTE) during these three years
of activity. We show that, in spite of having a similar spectral and timing
behaviour in the energy range between 3 and 30 keV, these three outbursts show
pronounced differences above 30 keV. In fact, the 2010 outburst extends at high
energies without any detectable cut-off until 150-200 keV, while the two
previous outbursts that occurred in 2006 and 2008 are not detected at all above
30 keV. Thus, in spite of a very similar accretion disk evolution, these three
outbursts exhibit totally different characteristics of the Compton electron
corona, showing a softening in their evolution rarely observed before in a low
mass X-ray binary hosting a black hole. We argue the possibility that the
unknown perturbation that causes the outbursts to be equally spaced in time
could be at the origin of this particular behaviour. Finally we describe
several possible scenarios that could explain the regularity of the outbursts,
identifying the most plausible, such as a third body orbiting around the binary
system.Comment: April 2015: accepted for publication in MNRAS. May 2015: in pres
Subduction and break-off controls on Indentation tectonics and Western Syntaxis formation during India-Asia convergence
Abstract HKT-ISTP 2013
A
Mesozoic spreading kinematics: consequences for Cenozoic Central and Western Mediterranean subduction
The highly complex tectonics of Central and Western Mediterranean subduction are well documented, but there is significant debate about the responsible dynamics. The motions of the main plates, Africa including Adria, Europe and Iberia, imposed initial and boundary conditions on the evolution of subduction that are often not considered. To quantitatively evaluate these conditions, we make a set of reconstructions from Mesozoic opening through Cenozoic closing of the Alpine Tethys, using main-plate kinematic data from several authors. Geologic and tectonic information are only added to constrain the location of the break-up boundary and a single plate-margin rearrangement at the end of the opening phase. Otherwise, the plates remain undeformed. This rigid-plate approach illustrates the context in which surface deformation and subduction occurred and provides estimates (with uncertainties) of the amount of material that should be accounted for in orogens or documented seismically in the mantle. Full tectonic reconstructions should satisfy such constraints. Opening led to alternating domains of predominantly oceanic lithosphere formed by normal spreading and domains dominated by transform motion, floored mainly by extended continental lithosphere. The transform domain structures provide logical decoupling zones to allow Penninic, Ligurian and Pyrenean basins to start subducting independently. The complex buoyancy in the transform domain linking Ligurian and Penninic basins, and obliquity between directions of opening and closing may account for a number of the oceanic basins and continental slivers often invoked to explain Alpine geology. The significant proportion of continental lithosphere in the Alboran would have favoured delamination of mantle lithosphere over subduction. The almost completely subducted Penninic slab obstructed subduction of the Ligurian domain in the direction of Africa-Europe convergence, possibly forcing the rollback of the Appeninic/Calabrian trenc
The failed state transition of the ATOLL source GRS 1724-308
The 2004-2012 X-ray time history of the NS LMXB GRS 1724-308 shows, along
with the episodic brightenings associated to the low-high state transitions
typical of the ATOLL sources, a peculiar, long lasting (about 300 d) flaring
event, observed in 2008. This rare episode, characterised by a high-flux hard
state, has never been observed before for GRS 1724-308 , and in any case is not
common among ATOLL sources. We discuss here different hypotheses on the origin
of this peculiar event that displayed the spectral signatures of a failed
transition, similar in shape and duration to those rarely observed in Black
Hole binaries. We also suggest the possibility that the atypical flare occurred
in coincidence with a new rising phase of the 12-years super-orbital modulation
that has been previously reported by other authors. The analysed data also
confirm for GRS 1724-308 the already reported orbital period of about 90 d.Comment: accepted for publication in MNRA
The first outburst of the black hole candidate MAXI J1836-194 observed by INTEGRAL, Swift, and RXTE
MAXI J1836-194 is a transient black-hole candidate discovered in outburst by
MAXI on 30 August 2011. We report on the available INTEGRAL, Swift, and RXTE
observations performed in the direction of the source during this event before
55 864 MJD. Combining the broad band (0.6-200 keV) spectral and timing
information obtained from these data with the results of radio observations, we
show that the event displayed by MAXI J1836-194 is another example of "failed"
outburst. During the first ~20 days after the onset of the event, the source
underwent a transition from the canonical low/hard to the hard intermediate
state, while reaching the highest X-ray flux. In the ~40 days following the
peak of the outburst, the source displayed a progressive spectral hardening and
a decrease of the X-ray flux, thus it entered again the low/hard state and
began its return to quiescence.Comment: Accepted for A&A Letters on 22 Dec. 201
INTEGRAL high energy behaviour of 4U 1812-12
The low mass X-ray binary system 4U 1812-12 was monitored with the INTEGRAL
observatory in the period 2003-2004 and with BeppoSAX on April 20, 2000. We
report here on the spectral and temporal analysis of both persistent and burst
emission. The full data set confirms the persistent nature of this burster, and
reveals the presence of emission up to 200 keV. The persistent spectrum is well
described by a comptonization (CompTT) model plus a soft blackbody component.
The source was observed in a hard spectral state with a 1-200 keV luminosity of
2*10^(36) ergs/s and L/LEdd~1% and no meaningful flux variation has been
revealed, as also confirmed by a 2004 RXTE observation. We have also detected 4
bursts showing double peaked profiles and blackbody spectra with temperatures
ranging from 1.9 to 3.1 keV.Comment: 6 pages, 4 figures. Accepted for publication by A&
RISCHIO, CRISI E INTERVENTO PUBBLICO NELL'AGRICOLTURA EUROPEA
Esiste un’ampia discussione tra le Istituzioni Europee (Commissione, Parlamento e Governi degli Stati Membri) sull’opportunità di istituire un quadro istituzionale di riferimento a livello europeo per la gestione del rischio e delle crisi in agricoltura. Allo scopo di analizzare la posizione assunta dalla Commissione Europea nel Marzo del 2004, l’articolo discute della possibilità di istituire un tale quadro comune di riferimento date le prospettive cui si trova di fronte la Politica Agricola Comune recentemente riformata. Nel far ciò, vengono passate in rassegna le misure esistenti nei vari Stati Membri e vengono valutati i punti di forza e di debolezza delle opzioni avanzate dalla Commissione. La conclusione è che, dati i vincoli esistenti sulla possibile espansione della spesa in agricoltura, l’istituzione di un programma comune basato sul pagamento di integrazioni di reddito o di sussidi a premi assicurativi è molto poco verosimile. Prospettive migliori sono quelle per un intervento basato sul sostegno di fondi mutualistici tra gli agricoltorie, più in generale, su sostegni indiretti al credito, alle assicurazioni e ai mercati finanziari, orientati al rendere tali strumenti più facilmente accessibili per gli agricoltor
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