Long-run relationship between crop-biodiversity and cereal production under the CAP reform: evidence from Italian regions

Biodiversity has a prominent role in defining and preserving ecosystem well-being; the analysis of biodiversity effects on agricultural production is well documented. The paper offers empirical evidence on the role of intra-species biodiversity in sustaining cereal production within Italian regions, covering a time span (1989-2007) which accounts for the important CAP policy reforms. A Cobb-Douglas production function that includes both biodiversity and subsidies as control variables is estimated for 20 Italian regions, controlling for both cross-sectional heterogeneity and the dynamic structure of agricultural production. Different estimation methods are compared, including Mean Group and Pooled Mean Group estimators which allow for the possibility of potential non stationarity of the series and heterogeneous parameters across-groups. We find clear evidence of significant long-run relationships between biodiversity and cereal production; moreover, the evidence on the role of PAC intervention measures is less clear-cut, showing a potentially negative effect on production along the period under analysis that can be attributed to the aforementioned policy shift.

Water resource as a factor of production - water use and economic growth

Water is one of the most important natural resources that is necessary for the rise and development of any biological and human activity. Being water resource a necessary good for multiple uses, it generates a series of competitive demands whose degree of competitiveness becomes greater in the presence of relevant and increasing pressure factors. The paper sets out a logical scheme for the analysis of productive uses of water, with the purpose of understanding both the functioning of an economy in the presence of a technical constraint to the exploitation of water resources, and the possible policy instruments available to the public authority. Our starting point is the definition of productive uses of water in terms of the amount of resource that is activated to make the stock of physical capital productive. Water resource is not a pure public good, it is available at private and social costs, given the existence of an optimal ratio between physical capital and water resources needed by the economic system in order to be productive. A complementarity hypothesis between the two forms of capital considered (physical and water capital) arises, with the first coming from private investment and the second being defined as the amount of public investment in services and infrastructures for water resource exploitation. As public investment in water capital crowds out private saving eventually available for private physical capital accumulation, an allocation criterion is needed to maximize total production of the system, never falling behind the optimal physical capital-water capital ratio. The first section of the paper reviews the literature dealing with the relationship between natural resources use and economic growth; the second section is focused on the presentation of a Solow-type model that introduces water in a general production function. In developing the model, equilibrium conditions in a “water economy” are described and a parametrical device is set in order to identify optimal taxation policies to finance public water infrastructures investment. The last section shows the results of an empirical analysis that is carried out in order to test the existence of a significant relationship between the aggregate use of water and per capita income produced by an economy. A country-based panel data analysis is performed with the aim of estimating a “water” production function.

GENETICA DI CONSERVAZIONE DI DUE SPECIE ALPINE IN DECLINO: APPROCCIO NON INVASIVO APPLICATO ALLO STUDIO DI LEPRE BIANCA (Lepus timidus) E PERNICE BIANCA (Lagopus mutus)

La lepre bianca (Lepus timidus varronis) e la pernice bianca (Lagopus mutus helveticus) sono considerate sull'arco alpino delle specie relitto delle passate glaciazioni, che hanno trovato rifugio e si sono adattate agli ambienti di alta montagna a cui ora restano strettamente legate. I cambiamenti climatici e antropici stanno causando un'elevata frammentazione dei territori occupati da queste specie, con conseguenti rischi di isolamento, diminuzione del successo riproduttivo e perdita di variabilità genetica. La riduzione della variabilità genetica per queste specie era già stata documentata in precedenti lavori. Con questa tesi sono state ampliate le conoscenze attuali sulla lepre bianca e la pernice bianca a livello di arco alpino, aggiungendo i campioni raccolti nel settore orientale (provincia di Belluno). Sono state inoltre testate per entrambe le specie delle metodiche di campionamento non invasivo e di estrazione e amplificazione del DNA da questo tipo di campioni. Per entrambe le specie è stata eseguita un'analisi del D-loop del DNA mitocondriale a livello di arco alpino, per indagare i livelli di variabilità e la presenza di struttura genetica. La stessa analisi per la pernice bianca è stata effettuata anche a livello di distribuzione globale della specie per confrontare la variabilità genetica e verificare quanto la sottospecie alpina si discosti geneticamente dalle altre popolazioni. Da queste analisi è emersa una considerevole struttura genetica per la lepre bianca, la cui variabilità genetica si presenta comunque ancora molto elevata a livello di arco alpino, estremamente bassa invece per la provincia di Belluno. Per la pernice bianca, invece, è stata riscontrata una debole struttura e dei valori di variabilità genetica superiori rispetto alle popolazioni nordiche. Per i campioni di pernice bianca raccolti nelle province di Belluno e Trento è stata, inoltre, eseguita un'analisi del DNA nucleare attraverso 10 loci microsatellite, dalla quale è emersa l'assenza di struttura a livello locale e un'elevata variabilità con valori di diversità genica paragonabili a quelli delle popolazioni nordiche. Da questa tesi emerge dunque la differente situazione genetica delle due specie a livello alpino: la pernice nonostante il calo demografico di cui ha risentito in varie località delle Alpi, presenta una buona salute genetica. Le analisi sulla lepre bianca, invece, evidenziano un quadro più critico, soprattutto in alcune aree. Si ritiene dunque necessaria un'attenta gestione ambientale e venatoria nei confronti di queste specie, per preservarne la variabilità genetica (e in alcuni casi favorirne l'incremento) e limitare la presenza o quanto meno minimizzare l'effetto di barriere che impediscano un adeguato flusso genico tra sotto-popolazioni.ope

Non-Natural Linker Configuration in 2,6-Dipeptidyl-Anthraquinones Enhances the Inhibition of TAR RNA Binding/Annealing Activities by HIV-1 NC and Tat Proteins

The HIV-1 nucleocapsid (NC) protein represents an excellent molecular target for the development of antiretrovirals by virtue of its well-characterized chaperone activities, which play pivotal roles in essential steps of the viral life cycle. Our ongoing search for candidates able to impair NC binding/annealing activities led to the identification of peptidylanthraquinones as a promising class of nucleic acid ligands. Seeking to elucidate the inhibition determinants and increase the potency of this class of compounds, we have now explored the effects of chirality in the linker connecting the planar nucleus to the basic side chains. We show here that the non-natural linker configuration imparted unexpected TAR RNA targeting properties to the 2,6-peptidyl-anthraquinones and significantly enhanced their potency. Even if the new compounds were able to interact directly with the NC protein, they manifested a consistently higher affinity for the TAR RNA substrate and their TARbinding properties mirrored their ability to interfere with NC-TAR interactions. Based on these findings, we propose that the viral Tat protein, sharing the same RNA substrate but acting in distinct phases of the viral life cycle, constitutes an additional druggable target for this class of peptidyl-anthraquinones. The inhibition of Tat-TAR interaction for the test compounds correlated again with their TAR-binding properties, while simultaneously failing to demonstrate any direct Tat-binding capabilities. These considerations highlighted the importance of TAR RNA in the elucidation of their inhibition mechanism, rather than direct protein inhibition. We have therefore identified anti-TAR compounds with dual in vitro inhibitory activity on different viral proteins, demonstrating that it is possible to develop multitarget compounds capable of interfering with processes mediated by the interactions of this essential RNA domain of HIV-1 genome with NC and Tat proteins

On the Impact of Trees on Ventilation in a Real Street in Pamplona, Spain

This paper is devoted to the quantification of changes in ventilation of a real neighborhood located in Pamplona, Spain, due to the presence of street trees Pollutant dispersion in this urban zone was previously studied by means of computational fluid dynamic (CFD) simulations. In the present work, that research is extended to analyze the ventilation in the whole neighborhood and in a tree-free street. Several scenarios are investigated including new trees in the tree-free street, and different leaf area density (LAD) in the whole neighborhood. Changes between the scenarios are evaluated through changes in average concentration, wind speed, flow rates and total pollutant fluxes. Additionally, wind flow patterns and the vertical profiles of flow properties (e.g., wind velocity, turbulent kinetic energy) and concentration, horizontally-averaged over one particular street, are analyzed. The approach-flow direction is almost perpendicular to the street under study (prevailing wind direction is only deviated 4º from the perpendicular direction). For these conditions, as LAD increases, average concentration in the whole neighborhood increases due to the decrease of wind speed. On the other hand, the inclusion of trees in the street produces an increase of averaged pollutant concentration only within this street, in particular for the scenario with the highest LAD value. In fact, the new trees in the street analyzed with the highest LAD value notably change the ventilation producing an increase of total pollutant fluxes inward the street. Additionally, pollutant dispersion within the street is also influenced by the reduction of the wind velocity along the street axis and the decrease of turbulent kinetic energy within the vegetation canopy caused by the new trees. Therefore, the inclusion of new trees in a tree-free street should be done by considering ventilation changes and traffic emissions should be consequently controlled in order to keep pollutant concentration within healthy levels

Analysis of urban greening scenarios for improving outdoor thermal comfort in neighbourhoods of Lecce (Southern Italy)

This study analyses the interactions and impacts between multiple factors i.e., urban greening, building layout, and meteorological conditions that characterise the urban microclimate and thermal comfort in the urban environment. The focus was on two neighbourhoods of Lecce city (southern Italy) characterised through field campaigns and modelling simulations on a typical hot summer day. Field campaigns were performed to collect greening, building geometry, and microclimate data, which were employed in numerical simulations of several greening scenarios using the Computational Fluid Dynamics-based and microclimate model ENVI-met. Results show that, on a typical summer day, trees may lead to an average daily decrease of air temperature by up to 1.00 °C and an improvement of thermal comfort in terms of Mean Radiant Temperature (MRT) by up to 5.53 °C and Predicted Mean Vote (PMV) by up to 0.53. This decrease is more evident when the urban greening (in terms of green surfaces and trees) is increased by 1266 m2 in the first neighbourhood and 1988 m2 in the second one, with respect to the current scenario, proving that shading effect mainly contributes to improving the urban microclimate during daytime. On the contrary, the trapping effect of heat, stored by the surfaces during the day and released during the evening, induces an increase of the spatially averaged MRT by up to 2 °C during the evenings and a slight deterioration of thermal comfort, but only locally where the concentration of high LAD trees is higher. This study contributes to a better understanding of the ecosystem services provided by greening with regard to microclimate and thermal comfort within an urban environment for several hours of the day. It adds knowledge about the role of green areas in a Mediterranean city, an important hot spot of climate change, and thus it can be a guide for important urban regeneration plans