Size, trend, and policy implications of the underground economy

We study the underground economy within a dynamic and stochastic general equilibrium framework. Our model combines limited tax enforcement with an otherwise standard two-sector neoclassical stochastic growth model. The Bayesian estimation of the model based on Italian data provides evidence in favor of an important underground sector in Italy, with a size that has increased steadily over the whole sample period. We show that this pattern is due to a steady increase in taxation. Fiscal policy experiments suggest that a moderate tax cut, along with a stronger effort in the monitoring process, causes a sizeable reduction in the size of the underground economy and provides a positive stimulus for the regular economy. Both of these effects jointly increase total fiscal revenues.Francesco Turino is grateful for the financial support provided by the Spanish Ministerio de Educación y Ciencia and FEDER funds (project SEJ-2007-62656/ECON)

Size, Trend, and Policy Implications of the Underground Economy

We study the underground economy in a dynamic and stochastic general equilibrium framework. Our model combines limited tax enforcement with an otherwise standard two-sector neoclassical stochastic growth model. The Bayesian estimation of the model based on Italian data provides evidence in favor of an important underground sector in Italy, with a size that has steadily increased over the whole sample period. We show that this pattern is due to a persistent increase in taxation. Fiscal policy experiments suggest that a moderate tax cut, along with a stronger effort in the monitoring process, causes a sensitive reduction in the size of the underground economy and positive stimulus to the regular sector that jointly increase the total fiscal revenues

Assessing the potential economic viability of precision irrigation: A theoretical analysis and pilot empirical evaluation

The present study explores the value generated by the use of information to rationalize the use of water resources in agriculture. The study introduces the value of information concept in the field of irrigation developing a theoretical assessment framework to evaluate whether the introduction of "Precision Irrigation" (PI) practices can improve expectations on income. This is supported by a Stakeholders consultation and by a numerical example, using secondary data and crop growth models. The study reveals that the value generated with the transition to PI varies with pedo-climate, economic, technological and other conditions, and it depends on the initial status of the farmer's information environment. These factors affect the prerequisite needed to make viable PI. To foster the adoption of PI, stakeholders envisaged the need to set up free meteorological information and advisory service that supports farmers in using PI, as well as other type of instruments. The paper concludes that the profitability of adoption and the relevant impact on the environment cannot be considered as generally given, but must be evaluated case by case justifying (or not) the activation of specific agricultural policy measures supporting PI practices to target regions

Meccanismi molecolari di regolazione dell’espressione del gene di GH e IGF-I da parte di PPAR-γ

L’Acromegalia è caratterizzata da eccessiva secrezione di ormone della crescita (GH),dovuta alla presenza di adenomi ipofisari, con il conseguente elevato aumento della sintesi del fattore di crescita insulino-simile di tipo I (IGF-I ). L’isoforma gamma del recettore attivato dai proliferatori dei perossisomi (PPARgamma), è un fattore di trascrizione nucleare appartenente alla superfamiglia dei recettori steroidei e tiroidei. PPARgamma è espresso negli adenomi ipofisari GH-secernenti, nella linea cellulare ipofisaria GH-secernente di ratto (GH3) e in misura minore, nel fegato. I tiazolidinedioni (TZDs), ligandi sintetici di PPARgamma, sono stati proposti come nuovi farmaci nel trattamento degli adenomi ipofisari. Nel fegato, il GH stimola la produzione di IGF-I attivando STAT5b. Lo scopo del progetto di ricerca è stato quello di valutare il ruolo di PPARgamma e dei suoi ligandi nella regolazione dell’espressione di GH e di IGF-I, sia in vitro, impiegando due linee cellulari specifiche dell’ipofisi e del fegato (GH3 e HepG2, rispettivamente), sia in vivo, utilizzando un modello acromegalico murino. I risultati dimostrano che nelle GH3, i TZDs inibiscono la sintesi e la secrezione dell’ormone della crescita, attraverso un meccanismo PPARgamma¬dipendente che coinvolge la 5’flanking region del gene del GH (hGH). PPARgamma, come complesso eterodimerico con il recettore dell’acido 9-cis (RXRalfa), si lega al promotore di hGH in corrispondenza della sequenza nucleotidica di 54 paia di basi (bp) tra la posizione -330 e -276, indicando la presenza di un putativo elemento di risposta a PPAR (PPRE). Nelle HepG2, i TZDs inibiscono l’espressione di IGF-I con un meccanismo PPARgamma-dipendente; tuttavia, in esperimenti di trasfezione transitoria impiegando la 5’flanking region del gene di IGF-I, i ligandi di PPARgamma non modificano il livello di espressione del “reporter gene”, suggerendo un effetto indiretto. Inoltre, il trattamento con GH, come atteso, aumenta l’espressione di STAT5b, contrariamente ai TZDs che la riducono. Perciò è probabile che l’azione del GH e dei ligandi di PPARgamma nella regolazione dell’espressione di IGF-I sia mediata, a livello molecolare, da STAT5b. D’altra parte, un esperimento pilota impiegando topi transgenici che sovraesprimono il GH bovino, dimostra che somministrando a lungo termine i TZDs (1mg/Kg die) non si modifica il livello di IGF-I circolante. Al contrario, trattando ratti Wistar-Furth portatori di tumori GH-secernenti con rosiglitazone (120mg/Kg die) si osserva una riduzione significativa della concentrazione sierica di IGF-I. In conclusione, i dati riportati suggeriscono che i TZDs potenzialmente possono regolare l’espressione di GH nell’ipofisi e di IGF-I nel fegato con un meccanismo tessuto-specifico; tuttavia, sono necessari ulteriori studi per chiarire il loro ruolo nel trattamento dell’acromegalia

Cardiovascular Risk Prediction in Patients With Human Immunodeficiency Virus

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The value of information for the management of water resources in agriculture: Assessing the economic viability of new methods to schedule irrigation

Abstract This study develops a methodology to assess the comparative advantages of new methods to plan irrigation with respect to prevailing existing irrigation practices. The methodology consists of a comparative cost-benefit analysis based on the Value of Information approach that makes it possible to analyse whether an improvement in the information available to farmers generates economic benefits. The method is applied to the problem of comparing computer irrigation models (providing irrigation advice based on measurements, water balance models and weather predictions) and prevailing irrigation practices (at times based on soil and plant observations, or on advanced technologies) in estimating and predicting crop water requirements, in pilot experiments located in four different European regions. The results reveal that the introduction of the alternative method improves the performance of irrigation practices in Mediterranean regions that are characterised by high weather variability and for those crops for which the consequences of failing to meet predictions are relatively low (i.e. tomato instead of maize, drip irrigated crops instead of sprinkler irrigated crops). Under favourable conditions, the use of the alternative technology generates a 0–20% increase in gross margin and a 10–30% water saving with respect to prevailing existing irrigation practices. The study concludes by addressing the conditions that justify the use of advanced information systems to schedule irrigation interventions and by offering some policy recommendations to drive their uptake. These include subsidising research at the evaluation stage and public investments aimed at knowledge creation (weather and shallow water table monitoring stations) and knowledge sharing (counselling) at the adoption stage

Lacking P2X7-receptors protects substantia nigra dopaminergic neurons and hippocampal-related cognitive performance from the deleterious effects of high-fat diet exposure in adult male mice

BackgroundDietary fat consumption, involved in the pathogenesis of insulin resistance and impaired glucose metabolism, is linked with decline in cognitive functions, dementia, and development of Parkinson’s disease and Alzheimer’s disease. Mature IL-1β, requiring the activation of the P2X7 receptor (P2X7R)-inflammasome complex, is an important mediator of neuroinflammation. The aim of the study was to test whether P2X7R activation might interfere with systemic and cerebral metabolic homeostasis.MethodsWe treated WT and P2X7R KO mice with a high-fat diet (HFD) for 16 weeks, evaluating the effects on the Substantia Nigra and Hippocampus, target areas of damage in several forms of cognitive impairment.ResultsHFD-treated WT and P2X7R KO mice showed a different brain mRNA profile of Insulin and Igf-1, with these genes and relative receptors, more expressed in KO mice. Unlike P2X7R KO mice, WT mice treated with HFD displayed a diameter reduction in dopaminergic neurons in the Substantia Nigra, accompanied by an increased IBA1 expression in this area; they also showed poor performances during Y-Maze and Morris Water Maze, tasks involving Hippocampus activity. Conversely, Parkin, whose reduction might promote neuronal cell death, was increased in the brain of P2X7R KO animals.ConclusionWe report for the first time that HFD induces damage in dopaminergic neurons of the Substantia Nigra and a Hippocampus-related worse cognitive performance, both attenuated in the absence of P2X7R. The involved mechanisms might differ in the two brain areas, with a predominant role of inflammation in the Substantia Nigra and a metabolic derangement in the Hippocampus

Growth Hormone Is Necessary for the p53-Mediated, Obesity-Induced Insulin Resistance in Male C57BL/6J × CBA Mice

Insulin resistance is a key marker of both obesity and GH excess. The purpose of the study was to assess the role of GH on p53-mediated insulin resistance of male mice with obesity due to a high-fat diet. C57BL/6J CBA male mice fed on a high-fat diet (Obe) were studied; male mice fed a normal diet (Lean) or transgenic mice for bovine GH under the same genetic background (Acro) served as controls. The convergence of p53 and GH pathways was evaluated by Western blot. Obe mice had insulin resistance, which was sustained by a selective increased expression of p53 in adipose tissue. Normal insulin sensitivity was restored, and adipose p53 expression normalized when the GH pathway was blocked. Only the adipose p53 expression was sensitive to the GH blockage, which occurred through the p38 pathway. Adipose tissue of Obe mice had a coordinate overexpres- sion of suppressors of cytokine signal 1–3 and signal transducers and activators of transcrip- tion-1, -3, and -5b, not different from that of Acro mice, suggesting an increased sensitivity of adipose tissue to GH. On the contrary, Lean mice were unaffected by changes of GH action. GH seems to be necessary for the increased adipose p53 expression and for insulin resistance of obese mice