Fractional differential equations solved by using Mellin transform

In this paper, the solution of the multi-order differential equations, by using Mellin Transform, is proposed. It is shown that the problem related to the shift of the real part of the argument of the transformed function, arising when the Mellin integral operates on the fractional derivatives, may be overcame. Then, the solution may be found for any fractional differential equation involving multi-order fractional derivatives (or integrals). The solution is found in the Mellin domain, by solving a linear set of algebraic equations, whose inverse transform gives the solution of the fractional differential equation at hands.Comment: 19 pages, 2 figure

Open Source Software: From Open Science to New Marketing Models

-Open source Software; Intellectual Property; Licensing; Business Model.

ICT, Skills and Organisational Change: Evidence from a Panel of Italian Manufacturing Firms

This paper explores the complementarity between skills, organizational change and investments in information and communication technology (ICT). Our work contributes to the literature on the effects of ICT by testing the hypothesis of complementarity in a panel of 540 Italian manufacturing firms during the period 1995-2000. Our analysis provides strong support to the hypothesis of complementarity between skills and ICT (which is at the core of the skill-biased technical change theory). We also find some evidence in favour of the skill-biased organizational change hypothesis. The results obtained by drawing on different statistical methods suggest that interactions among ICT, skills and organizational change are complex and non-linear and difficult to explain.Organisational Change, ICT Investment, Workplace Organization, Human Capital, Productivity

Galectin genes: regulation of expression.

In this review we have summarized the more recent studies on the expression of mammalian galectins. One interesting observation that can be made is that in most of microarrays and/or differential display analysis performed in recent years one or more galectins have been picked up. From a critical evaluation of the pertinent studies the main conclusion that can be drawn is that, although it is not yet clear whether the 14 galectins identified so far have functions in common, a striking common feature of all galectins is the strong modulation of their expression during development, differentiation stages and under different physiological or pathological conditions. This suggests that the expression of different galectins is finely tuned and possibly coordinated. In spite of these observations it is rather unexpected that very few studies have been performed on the molecular mechanisms governing the activity of galectin genes

Skills, Division of Labor and Performance in Collective Inventions. Evidence from the Open Source Software

This paper investigates the role of skills and the division of labor among participants in collective inventions. Our analysis draws on a large sample of projects registered at Sourceforge.net, the world’s largest incubator of open source software activity. We explore the hypothesis that the level of skills of participants and their skill variety are important for project performance. Skill heterogeneity across participants is in line with two fundamental organizational features of the open source development model: team work and modular design. We also test the hypothesis whether the level of modularization of project activities is an important predictor of performance. The results provide support to the hypothesis that the skill level is important for the survival of open source projects. Moreover, we found that skill heterogeneity is positive for innovation. Finally, design modularity is positively associated with the performance of the project.Software, Technological innovation, Human capital, Modularity

Exploring the link among state of mind concerning childhood attachment, attachment in close relationships, parental bonding, and psychopathological symptoms in substance users

In the present study, we have explored the link among styles of attachment and psychopathology in drug users. We know that insecure attachment predisposes the individuals the development of drug-addiction and psychopathological symptoms. However, we do not know which attachment is more frequent in drug users and which is related to particular psychopathological symptoms. The aim of the present work is to explore the relationship between childhood attachment state of mind, attachment in close relationships, parental bonding and psychopathology in sample of Italian substance users

From soil remediation to biofuel. Process simulation of bioethanol production from Arundo donax

A range of energy crops can be grown on marginal land (i.e. land that is not suitable for food crop production or contaminated site) to provide feedstocks for bioenergy, non-food products and biofuels. The food versus fuel debate had a significant negative impact in Europe on first generation biofuels production from food crops (i.e. wheat, rapeseed, etc). A new approach involving the use of marginal land for the production of lignocellulosic species for the production of bioethanol is now pursued in Italy and in many other countries, where the demand for high quality water resources, arable land, food and fossil fuels is rapidly growing. With an emerging “feed versus fuel debate” there is a pressing need to find options for the use of marginal lands and wastewaters or saline ground waters to produce second generation biofuel or bio paper crops. Arundo donax was selected as a potential crop for use in these areas, since it produces more cellulosic biomass and sequesters more contaminants, using less land and pesticides than any other alternative crops reported in the literature. The objective of this paper is to evaluate economically a simplified process for the production of second generation bioethanol from A. donax. Process calculations and economic analyses are performed using the software SuperPro Designer®

Genes and primary headaches: discovering new potential therapeutic targets

Genetic studies have clearly shown that primary headaches (migraine, tension-type headache and cluster headache) are multifactorial disorders characterized by a complex interaction between different genes and environmental factors. Genetic association studies have highlighted a potential role in the etiopathogenesis of these disorders for several genes related to vascular, neuronal and neuroendocrine functions. A potential role as a therapeutic target is now emerging for some of these genes. The main purpose of this review is to describe new advances in our knowledge regarding the role of MTHFR, KCNK18, TRPV1, TRPV3 and HCRTR genes in primary headache disorders. Involvement of these genes in primary headaches, as well as their potential role in the therapy of these disorders, will be discussed

Mellin transform approach for the solution of coupled systems of fractional differential equations

In this paper, the solution of a multi-order, multi-degree-of-freedom fractional differential equation is addressed by using the Mellin integral transform. By taking advantage of a technique that relates the transformed function, in points of the complex plane differing in the value of their real part, the solution is found in the Mellin domain by solving a linear set of algebraic equations. The approximate solution of the differential (or integral) equation is restored, in the time domain, by using the inverse Mellin transform in its discretized form

Sediment features and heavy metal levels in four areas of Sardinia devoted to bivalve culture = Caratteristiche dei sedimenti e livelli di metalli pesanti in quattro aree della Sardegna idonee all’allevamento dei bivalvi

Sediment characteristics and Cd, Cu, Mn, Pb and Zn concentrations were assessed in the lagoons of Marceddì, Calich and Porto Pozzo, and in the inner part of the Gulf of Olbia. Sediment of the zones examined were quite similar, except for the Calich lagoon that showed the higher content of total organic carbon. High values of Cd, Pb and Zn were detected in the sediments of the Marceddì lagoon, while remarkable levels of Cu and Mn were found in the Calich lagoon and in the Gulf of Olbia