1,204 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 farmersā 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 farmersā 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
The cytochrome chain of mitochondria exhibits variable H+/eā stoichiometry
AbstractA study is presented of the āH+/eā stoichiometry for H+ pumping by the cytochrome chain in isolated rat liver mitochondria under level-flow and steady-state conditions. It is shown that the āH+/eā stoichiometry for the cytochrome chain varies under the influence of the flow rate and transmembrane ĪĪ¼H+. The rate-dependence is shown to be associated with cytochrome c oxidase, whose āH+/eā ratio varies from 0 to 1, whilst the āH+/cā ratio for the span covered by cytochrome c reductase is invariably 2
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
X-ray spectral state evolution in IGR J17091-3624 and comparison of its heartbeat oscillation properties with those of GRS 1915+105
In this work, we study the X-ray timing and spectral evolution of the
transient low mass X-ray binary IGR J17091-3624 during first 66 days of its
2011 outburst. We present results obtained from observations with two
instruments, Rossi X-ray Timing Explorer (RXTE)/Proportional Counter Array
(PCA) and SWIFT/X-ray telescope (XRT), between 09 February, 2011 and 15 April,
2011. Using quasi-periodic oscillation classifications, power density spectrum
characteristics, time-lag behavior and energy spectral properties, we determine
source states and their transitions at different times of the outburst. During
the first part of the evolution, the source followed trends usually observed
from transient black hole X-ray binaries (BHXBs). Interestingly, a gradual
transition is observed in IGR J17091-3624 from the low-variability SIMS,
commonly seen in BHXBs, to a high-variability state with regular, repetitive
and structured pulsations, seen only from GRS 1915+105 (also known as 'rho'
class variability/'heartbeat' oscillations). We study the time evolution of
characteristic time-scale, quality factor and rms amplitude of heartbeat
oscillations in IGR J17091-3624. We also present a detailed comparison of the
timing and spectral properties of heartbeat oscillations and their evolution in
IGR J17091-3624 and GRS 1915+105.Comment: 23 pages, 10 figures, 3 tables, accepted for publication in the Ap
Timescales of successful and failed subduction: insights from numerical modelling
The relatively short duration of the early stages of subduction results in a poor geological record, limiting our understanding of this critical stage. Here, we utilize a 2D numerical model of incipient subduction, that is the stage after a plate margin has formed with a slab tip that extends to a shallow depth and address the conditions under which subduction continues or fails. We assess energy budgets during the evolution from incipient subduction to either a failed or successful state, showing how the growth of potential energy, and slab pull, is resisted by the viscous dissipation within the lithosphere and the mantle. The role of rheology is also investigated, as deformation mechanisms operating in the crust and mantle facilitate subduction. In all models, the onset of subduction is characterized by high lithospheric viscous dissipation and low convergence velocities, whilst successful subduction sees the mantle become the main area of viscous dissipation. In contrast, failed subduction is defined by the lithospheric viscous dissipation exceeding the lithospheric potential energy release rate and velocities tend towards zero. We show that development of a subduction zone depends on the convergence rate, required to overcome thermal diffusion and to localise deformation along the margin. The results propose a minimum convergence rate of ā¼ 0.5 cm yrā1 is required to reach a successful state, with 100 km of convergence over 20 Myr, emphasizing the critical role of the incipient stage
Electro-optic deflectors deliver advantages over acousto-optical deflectors in a high resolution, ultra-fast force-clamp optical trap
Probing mechanotransduction in living cells by optical tweezers and FRET-based molecular force microscopy
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