A multi-regional general equilibrium model to assess policy effects at regional level

This paper develops a multi-regional general equilibrium model (MEG-R) to compare the social desirability of the CAP reform in the three Italian macro-regions: North, Center and South. The model employs a mixed complementary framework that allows for the decision of not producing a particular crop in one or more regions and presents an attempt to model interregional trade flows. The model incorporates the links between production and consumption that characterize farm household’s behavior and allows for heterogeneous household responses across regions. Results show a general tendency to reallocations from cereal crops to forage that appear more severe in the South. In this region, the reduction in crops cannot be translated into an effective expansion of fodder and could lead to the “deactivation” of the land.Multi-regional general equilibrium model, farm households, interregional trade, Agricultural and Food Policy, C68, R13, Q18,

A multi-regional general equilibrium model to assess policy effects at regional level

In this paper we develop a multi-regional general equilibrium model (MEG-R) to compare the social desirability of the CAP reform in the three Italian macro-regions: North, Center and South. The model employs a mixed complementary framework that allows for the decision of not producing a particular crop in one or more regions and presents an attempt to model interregional trade flows. The model incorporates the links between production and consumption that characterize farm household’s behavior and allows for heterogeneous household responses across regions. Results show a general tendency to reallocations from cereal crops to forage that appear more severe in the South. In this region, the reduction in crops cannot be translated into an effective expansion of fodder and could lead to the “deactivation” of the land.Multi regional general equilibrium model, farm households, interregional trade., Agribusiness, Agricultural and Food Policy, Community/Rural/Urban Development, Food Consumption/Nutrition/Food Safety, Labor and Human Capital,

High-frequency seasonal variation of leaf fluorescence and reflectance in Mediterranean forest species under natural environmental conditions

The strategies of two evergreen Mediterranean tree species (Arbutus unedo L. and Quercus ilex L.) to face annual temperature variability and extreme event responses has been monitored in continuum by leaf fluorescence and reflectance. The effect of chilling spells and the accumulation of cold days with chilling and freezing temperatures on winter photo-inhibition was discussed in terms of modulation capacity for fluorescence parameters to daily temperature and irradiance conditions. Throughout the winter Q. ilex resulted less photoinhibited than A. unedo, showing a more dynamic response in all fluorescence parameters and a higher non-photochemical quenching capacity. These characteristics effectively act to maintain a higher electron transport capacity in Q. ilex than in A. unedo

Construction and Simulation of the General Economic Equilibrium Model Meg-Ismea for the Italian Economy

Common Agricultural Policy, Agricultural policy, reform, Computable general equilibrium models.

Let's Exploit Available Knowledge on Vegetation Fluorescence

The potential to measure vegetation fluorescence from space (1) and to derive from it direct information on the gross primary productivity (GPP) of terrestrial ecosystems is probably the most thrilling development in remote sensing and global ecology of recent years, as it moves Earth observation techniques from the detection of canopy biophysics (e.g., fraction of absorbed radiation) and biochemistry (chlorophyll and nitrogen content) to the realm of ecosystem function. The existence of a functional relationship between fluorescence and photosynthesis has been elucidated over the last decade by several laboratories, notably as part of the preliminary studies of the European Space Agency Fluorescence Explorer (FLEX) Earth Explorer Mission. The empirical observation presented by Guanter et al. (2) of a linear relationship between fluorescence radiance and GPP, however, provides the first experimental confirmation of the feasibility of the approach already thoroughly tested at leaf levelat the desired scale, despite the confounding effects associated with the satellite detection of such a faint signal. A word of clarification is needed here. The use of fluorescence as a probe of leaf photochemistry has been a staple of plant ecophysiology for decades, rooted in a sound understanding of photosynthetic energy dissipation. However, most past studies had to rely for the interpretation of results on active (pulse-saturated) techniques, making them unsuitable for remote-sensing applications. Over recent years, however, novel process based models have been developed for the interpretation of steady-state, solar-induced fluorescence at the leaf to canopy scale (3). We are therefore in a position to move beyond the mere empirical observation of an association between GPP and fluorescence radiance. In particular, Guanter et al. (2) base their analysis on the assumption of a constant ratio between photosynthetic and fluorescence light use efficiencies (equation 3 in ref. 2).We know, however, that the ratio is not constant, but changes widely in response to light, CO2, stomatal limitations, and extreme stress (4, 5). Whats more, we can make sense of such changes, thus extracting valuable information from the very scatter that is apparent in their data. However, this process will require the availability of more tailored instruments, such as the one planned for the FLEX mission. As already stressed by Guanter et al. (2), the spatial resolution of the Global Ozone Monitoring Experiment-2 sensor (40 80 km) makes it difficult to compare meaningfully the fluorescence signal with ground measurements, when only 6070% of the footprint consists of the desired land-cover type (table S1 in ref. 2), suggesting that this could be largely responsible for the low signals observed in European grasslands. Moreover, the overpass time of the MetOp-A satellite (9:30 AM) implies that fluorescence is generally measured under light-limiting conditions, when fluorescence is only marginally affected by stomatal closure even under stress conditions. This result could explain the seasonal mismatch with daily GPP observed in natural ecosystems in the absence of irrigation (figure 4 in ref. 2). We hope, therefore, that this welcome contribution to this fast-advancing field will help demonstrate the potential of the new technique, and pave the way for more refined studies under both a technological and scientific point of view

Afforestazione e fissazione della CO2 atmosferica: qualche cifra indicativa dalla ricerca scientifica

Afforestation is often proposed as one of the most effective nature-based solutions to sequester carbon from the atmosphere, so mitigating the impending climate crisis. As a result, we have witnessed over the last few years a flourishing of projects aimed at planting new forests, particularly in periurban and agricultural settings, without a preliminary scientific discussion of their expected impact. In this contribution, we have therefore tried to summarize the evidence available for Italian settings, so as to define the range of sequestration rates that can be realistically expected. Moreover, we have tried to highlight some of the issues (age effects, single tree vs. stand perspective) that should be taken into account in the debate in order to harmonize results and approaches. Based on available evidence, under mesic conditions and with adequate cures at and after planting, we could realistically expect over the first decades a Net Ecosystem Production of about 3.5 t C ha-1 yr-1, in good agreement with results from other European deciduous tree plantations. Higher rates are definitely possible with fast-growing species (e.g., poplar, eucalypt) and intensive management, not always compatible with the environmental aims of such projects. In conclusion, afforestation can yield important results (also considering the other ecosystem services provided, particularly important in peri-urban and agricultural settings), although far from the C sequestration provided by the protection and sustainable management of existing forests

A global assessment of forest surface albedo and its relationships with climate and atmospheric nitrogen deposition

We present a global assessment of the relationships between the short-wave surface albedo of forests, derived from the MODIS satellite instrument product at 0.5° spatial resolution, with simulated atmospheric nitrogen deposition rates (Ndep), and climatic variables (mean annual temperature Tm and total annual precipitation P), compiled at the same spatial resolution. The analysis was performed on the following five forest plant functional types (PFTs): evergreen needle-leaf forests (ENF); evergreen broad-leaf forests (EBF); deciduous needle-leaf forests (DNF); deciduous broad-leaf forests (DBF); and mixed-forests (MF). Generalized additive models (GAMs) were applied in the exploratory analysis to assess the functional nature of short-wave surface albedo relations to environmental variables. The analysis showed evident correlations of albedo with environmental predictors when data were pooled across PFTs: Tm and Ndep displayed a positive relationship with forest albedo, while a negative relationship was detected with P. These correlations are primarily due to surface albedo differences between conifer and broad-leaf species, and different species geographical distributions. However, the analysis performed within individual PFTs, strengthened by attempts to select ‘pure’ pixels in terms of species composition, showed significant correlations with annual precipitation and nitrogen deposition, pointing toward the potential effect of environmental variables on forest surface albedo at the ecosystem level. Overall, our global assessment emphasizes the importance of elucidating the ecological mechanisms that link environmental conditions and forest canopy properties for an improved parameterization of surface albedo in climate models

Inhibition of HIV-1 replication in macrophages by red blood cell-mediated delivery of a heterodinucleotide of azidothymidine and 9-(R)-2-(phosphono methoxypropyl)adenine.

Monocyte-derived macrophages (M/M) are considered important in vivo reservoirs for different kinds of viruses, including HIV. Hence, therapeutic strategies are urgently needed to protect these cells from virus infection or to control viral replication. In this paper, we report the synthesis, target delivery and in vitro efficacy of a new heterodinucleotide (AZTpPMPA), able to inhibit HIV-1 production in human macrophages. AZTpPMPA consists of two established anti-HIV drugs [zidovudine (AZT) and tenofovir (PMPA)] chemically coupled together by a phosphate bridge. This drug is not able to prevent p24 production when administered for 18 h to M/M experimentally infected with HIV-1 Bal (inhibition 27%), but can almost completely suppress virus production when given encapsulated into autologous erythrocytes (inhibition of p24 production 97%). AZTpPMPA is slowly converted to PMPA, AZT monophosphate and AZT (36 h half-life at 37°C) by cell-resident enzymes. Thus AZTpPMPA should be considered a new prodrug of AZT and PMPA that is able to provide stechiometric amounts of both nucleoside analogues to macrophage cells and to overcome the low phosphorylating activity of M/M for AZT and the modest permeability of PMPA