1,518 research outputs found
Sviluppo rurale e occupazione
No full textContenente: a) ESPOSTI R., L’andamento generale dell’economia delle Marche, 47-62. b) ESPOSTI R., I risultati del settore agricolo secondo la RICA, 158-185. c) ESPOSTI R., Sviluppo regionale sviluppo rurale nelle Marche, 263-296
Le dinamiche del rurale. Letture del caso italiano
No full textContenente: a) ESPOSTI R. e Sotte F., Introduzione, 9-20. b) ESPOSTI R., Crescita, disoccupazione, e cambiamento strutturale: convergenza economica e aree rurali, 83-108. c) ESPOSTI R., e Berloni, D., Contiguità spaziale, migrazione e produttività: una analisi provinciale della dimensione rurale, 159-177
PUBLIC R&D INVESTMENT FROM PRIVATE AND SOCIAL PERSPECTIVE. AN APPLICATION TO ITALIAN AGRICULTURE, 1960-1995
No full textPublic R&D stock is considered as quasi-fixed input in a variable cost function. Its shadow price allows to measure the long run optimal level thus explicitly assessing the hypothesis of under (over) investment. Two alternative R&D prices are defined depending on whether the social or private (farmers) view prevails. The results under these alternatives provide evidence on the hypothesis that free-riding on public R&D explain overinvestment. The application to the Italian agriculture (1960-1995) suggests overinvestment in public research since the late seventies with a significant difference between the social and private optimal R&D, the former being much closer to the observed level.Research and Development/Tech Change/Emerging Technologies,
La dimensione rurale dello sviluppo locale. Esperienze e casi di studio. Milano: Franco Angeli.
No full textContenente: a) ESPOSTI R. e Sotte, F., Il quadro metodologico, 9-26. b) ESPOSTI R. e Sotte, F., “Poli Rurali” e processi di integrazione territoriale: Ancona ed Ascoli Piceno, 167-219
Why Should Regional Agricultural Productivity Growth Converge? Evidence from Italian Regions
No full textThe paper analyses agricultural TFP growth across Italian regions during the 1952-2002 period, and aims at identifying those factors that favour or hinder regional agricultural TFP growth convergence. Of major relevance is whether regions, despite their inescapable heterogeneity, tend to share common technological improvements, that is, to move along the same productivity growth rate. TFP growth decomposition ultimately allows attributing observed productivity performance to convergence and divergence forces. Appropriate testing and estimation procedures are adopted to take into account panel unit-root issues and cross-sectional dependence.TFP growth, Convergence, Panel Data, Productivity Analysis,
Building the Knowledge Stock: Lags, Depreciation, and Uncertainty in R&D Investment and Link with Productivity Growth
No full textThe search for an appropriate methodology to investigate the relation between R&D investment,
knowledge stock and productivity growth is the main purpose of the paper. In
analogy with physical assets, we present a model of knowledge capital formation which
allows the calculation of the relevant user cost, as well. The proposed model accumulates
R&D investment based on a stochastic gestation lag and a geometric depreciation
of the stock. The basic parameters underlying the lag structure differ according to the
types of research expenditure. The approach is applied to public R&D investment in
Italian agriculture; the results provide interesting information about the economic structure
of public research effort in Italian agriculture and plausible estimates of its internal rate
of return
Price, private demand and optimal provision of public R&D investment: An application to Italian agriculture, 1960–1995
No full textPublic agricultural R&D, Variable cost function, R&D price, Q160, O300,
Public R&D investment and cost structure in Italian agriculture, 1960-1995
No full textThis paper deals with the role of public research in Italian agriculture during the period
1960–1995. A short-run Generalised Leontief cost function capable of accommodating
quasi-fixed factors and variable returns is used. Temporary equilibrium and scale
economies are investigated with special emphasis on the methodological implications
of R&D stock and the consistency of the estimated model with microeconomic theory.
Comparing the relevant shadow and rental price provides evidence on under- (over)-
investment and the rationale driving public research expenditure in agriculture. A
formal test of the induced innovation hypothesis and the calculation of the internal
rate of returns are also presented
Agricoltura e natura
No full textContenente: ESPOSTI R., Moderne biotecnologie e agricoltura: una analisi delle implicazioni economiche, 47-65
Synchronisation of hand-foot coupled movements does not need interlimb feedback interactions
No full textIt has been prospected that synchrony of coupled limb oscillations may be controlled by mutual kinaesthetic feedback between the limbs [1, 5, 3]. Recent analysis of agonist-antagonist alternation in different mechanical contexts [2] led to hypothesise that oscillatory movements of each limb may be controlled by a neural mechanism that compares the intended position (encoded by a ‘central command’) with the actual position (encoded by the kinaesthetic afferences) and corrects for position errors. By this ‘private’ position controller, each limb may continuously adjust the movement to the central motor command, overcoming the mechanical contingencies. Through this mechanism, synchrony of coupled movements may be accomplished by independent linkage of each limb to a common clock signal, without need of an interlimb afferent feedback.
To test this hypothesis, subjects were asked to rhythmically oscillate their hand (prone) and foot on the parasagittal plane, either alone or together (iso- and antidirectionally coupled), taking care of carefully synchronising the oscillation peaks to the metronome. Movement position error was expressed as the phase-lag between the metronome beat (intended oscillation peak) and the actual oscillation peak. Oscillations were performed at different frequencies (0.4-3.0Hz), in unloaded conditions and after inertial loading of either extremity. Wrist and ankle angular position and EMG from the respective flexors and extensors were recorded.
With the limbs uncoupled and unloaded, the peak of both the hand and foot oscillations maintained a slight constant phase-delay with respect to the metronome over all frequencies (mean: hand 13.2°; foot -4.7°). This constancy was obtained by phase-advancing, at each frequency increment, the EMG activation with respect to the clock by the amount necessary to compensate for the simultaneous increase of the EMG-movement phase-lag, caused by limb mechanical impedance.
If the EMG-movement phase-lag was further increased by loading the moving limb, the phase-advance of EMG activation, albeit increased, became insufficient for a complete compensation and the movement progressively phase-lagged the metronome.
When limb oscillations were iso- or antidirectionally coupled, either in loaded or unloaded condition, all delays remained unchanged with respect to values measured when each limb was moved separately, showing that the synchrony control of either limb was uninfluenced by the simultaneous movement of the other limb. Thus, during both iso- and antidirectional hand-foot oscillations, each limb seems synchronised to a common clocking process [4] by a ‘private’ position control, with no need for a crossed feedback interaction between limbs.
References
1. Baldissera, F, Cavallari, P, Marini, G, Tassone, G (1991). Differential control of in-phase and anti-phase coupling of rhythmic movements of ipsilateral hand and foot. Exp Brain Res, 83, 375-380.
2. Esposti, R, Cavallari, P, Baldissera, F (2005). Partition of voluntary command to antagonist muscles during cyclic flexion-extension of the hand. Exp Brain Res, 162, 436-448.
3. Ridderikhoff, A, Peper, CE, Beek, PJ (2005). Unravelling interlimb interactions underlying bimanual coordination. J Neurophysiol, 94, 3115-3125.
4. Turvey, MT, Schmidt, RC, Rosenblum, LD, Kugler, PN (1986). Fluctuations and phase
symmetry in coordinated rhythmic movements. J Exp Psychol Hum Percept Perform, 12, 564–583.
5. Verschueren, SM, Swinnen, SP, Cordo, PJ, Dounskaia, NV (1999). Proprioceptive control of multijoint movement: bimanual circle drawing. Exp Brain Res, 127, 182-192
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