AN EFFICIENT AND STABLE STRUCTURE PRESERVING ALGORITHM FOR COMPUTING THE EIGENVALUES OF A HAMILTONIAN MATRIX

An efficient and stable structure preserving algorithm, which is a variant of the QR like (SR) algorithm due to Bunse-Gerstner and Mehrmann, is presented for computing the eigenvalues and stable invariant subspaces of a Hamiltonian matrix. In the algorithm two strategies are employed, one of which is called dis-unstabilization technique and the other is preprocessing technique. Together with them, a so-called ratio-reduction equation and a backtrack technique are introduced to avoid the instability and breakdown in the original algorithm. It is shown that the new algorithm can overcome the instability and breakdown at low cost. Numerical results have demonstrated that the algorithm is stable and can compute the eigenvalues to very high accuracy.

The interaction effect of foreign capital inflows and financial development on economic welfare in sub-Saharan Africa

This study examines the interaction effects of foreign capital inflows and financial development on economic welfare in sub-Saharan Africa(SSA).Estimates based on the system-GMM estimator using panel data on 23 SSA countries for 2000 to 2013 establish several results.First,the interaction between foreign capital inflows and financial development positively affects economic welfare in SSA.However,this effect was negative after one year.Second,the partial indirect effects of foreign capital inflows on economic welfare,conditional on the level of financial development,are positive,though they become negative after one year.Third,the total effect of foreign capital inflows on economic welfare is positive.The effect becomes negative after a year,though the predominant source of financial development is domestic credit.The consistency of these results indicates the importance of financial development in transmitting foreign capital to economic welfare enhancement.Developing the SSA’s financial sector to meet specific welfare-enhancing demands may potentially convert a large share of capital inflows into improved economic welfare and eliminate the negative effects.

Comparative Oral Absorption of Different Citicoline and Homotaurine Formulations: A Single-Dose, Two-Period Crossover Trial in the Dog

Background: Citicoline and homotaurine are compounds with a potent neuroprotective activity and they have been administered for many years in the treatment of numerous neurodegenerative and ophthalmological diseases, including glaucoma. Initially available only as liquid form, through parenteral route, nowadays citicoline can be administered also as tablet but no data on bioavailability of these different forms are available. In the present study, pharmacokinetics of citicoline in tablet versus vials, each at the therapeutic dose of 500 mg, in addition to 50 mg of homotaurine was investigated. Materials and methods: Ten mixed breed dogs received a single dose of 50 mg oral homotaurine and 500 mg citicoline in tablet and vials with the same dose were administered after a seven days wash-out period. Parameters assessed for citicoline metabolites (cytidine, uridine and choline) were AUC0−t, Cmax and Tmax. Results: Citicoline bioavailability appeared to be slightly higher for the tablet compared to the vial formulation. Cytidine is equivalent in absorption dynamics both for tablet and liquid form;uridine for tablet reaches its maximum and is reabsorbed more quickly while choline for the liquid form reaches the maximum first and is reabsorbed more quickly. Conclusions: Citicoline in tablet and liquid formulation have pharmacokinetic properties leading to a very similar bioavailability.

Revealed Cores: Characterizations and Structure

Characterizations of the classes of all choice functions that select the cores or the externally stable cores induced by an underlying revealed dominance digraph are provided. Relying on such characterizations, the basic order-theoretic structure of the corresponding sets of revealed cores is also analyzed. In particular, it is shown that the poset of all revealed cores ordered by set inclusion is a median meet semilattice: therefore, any profile of revealed cores may be aggregated by means of the simple majority rule.

Italian Psychometric Validation of the Multidimensional Students’ Health-Promoting Lifestyle Profile Scale

The present study examines the factorial structure and assesses the psychometric properties of the adapted multidimensional Health-Promoting Lifestyle Profile II Scale, considering a sample of Italian university students who participated to an online survey. The original 52-items Scale showed a high overall internal consistency. Four of the six subscales were associated with good values of the Cronbach’s α coefficient, whereas two subscales had lower values. Hence corrected item-total correlation was calculated and 26 items that decreased the scale’s reliability were deleted. The remaining 26 items were first subjected to Principal Component Analysis that suggested a conceptually meaningful five-factor model. This result was further supported by the first-order confirmatory factor analysis, in which all the factor loadings were statistically significant. The internal consistency and the composite reliability for the reduced version of the Scale and its subscales have shown a good reliability for the measurement models. The multidimensionality of the scale was also confirmed by a second-order factor model.

A Cumulative Proportional Odds Model to Analyze the Influence of Mass Media on Teenagers in Messina

The media are constantly evolving at a breakneck pace and mainly young people, with their flexibility of mind and their continuous curiosity, can better understand the characteristics and potential of such advances. The aim of this paper is to analyze the relationship between teenagers and media, in order to try to better understand the habits and to conduct analysis on social interactions with young people. In order to evaluate the influence of mass media in the life of the young people, the Statisticians of Messina University decided to perform a statistical survey to evaluate the influence of the media in the life of Messina＇s teenagers. A questionnaire entitled ＂Perceptions of the influence exerted by mass media＂ was administered in some schools. From the methodological point of view, three statistical models were estimated in order to formalize the dependence of the mass media influence by the kind of TV programs, the time spent on TV viewing and computer use and the kind of most used social networks. Since the mass media influence is an ordinal variable expressed by four ordered categories （1 = nothing; 2 = low; 3 = average; 4 = high） we used the Cumulative Proportional Odds Model to formalize the dependence by the potential predictors.

Consumer attitudes towards the mountain product label: Implications for mountain development

To protect and promote the originality and authenticity of mountain foodstuffs, the European Union set Regulation No 1151/2012 to create the optional quality term "mountain product". Our research aimed at exploring the attractiveness of the mountain product label for consumers, considering both attitude towards the label itself and purchase intentions. We propose a model to investigate relationships between four latent constructs-mountain attractiveness, mountain food attractiveness, attitude towards the mountain product label, and purchase intention-which have been tested, thus confirming the statistical relevance of the relationships. All 47 items selected for describing the latent constructs are suitable for this purpose. Ridge and LASSO results also show that 17 items of the first three constructs are relevant in explaining purchase intentions. Some contextual variables, such as age, income, geographical origin of consumers, and knowledge of mountain products and mountains for tourism purposes, can positively influence consumers’ behavior. These findings could support the design of mountain development strategies, in particular marketing actions for both the product and the territory.

The Future Human Lifespan: A Study on Italian Population

In the latter part of the 20th century, continued improvements in living standards, health behaviors, and medical care reduced mortality and produced amazing advances in life expectancy. These trends, followed by all industrial nations, decidedly affect the financial position of an insurance company, interested in the construction of updated life tables. The approach to this problem is faced in this paper by using the Lee-Carter methodology. In particular, in the present work, we are interested in modeling and forecasting mortality and life expectancy on a period basis through the use of a stochastic forecasting method which uses time-series models to make long-term forecasts.

Assessing Actuarial Projections Accuracy: Traditional vs. Experimental Strategy

This paper gives an overview of the Lee Carter method and reiterates the feasibility of using it to construct mortality forecast for the population data. In a first step, the model is fitted in a traditional way and used to extrapolate forecast of the time-varying mortality index. The observed pattern of the mortality rates shows a different variability at different ages, highlighting that the homoscedasticity hypothesis is quite unrealistic. Thus, in a second step, the paper aims to produce more reliable mortality forecasting, focusing on the errors in the estimation of the model parameters. The robustness of the estimated parameter is analysed throughout an experimental strategy which allows to assess the robustness of the Lee Carter model by inducing the errors to satisfy the homoscedasticity hypothesis. The graphical and numerical results are tested by means of a comparison in terms of prediction accuracy.

Fiscal illusion and progressive taxation with retrospective voting

This article addresses the tax progressivity decision of a rent-maxi-mising government under the circumstances that voters’percep-tions of the tax price of public goods are biased by cognitive anomalies(i.e.fiscal illusion)and that the electorate opts for re-appointing or for dismissing the incumbent according to a retro-spective voting logic.Given electoral and constitutional constraints,we show that the design of the tax system can be sensibly affected by fiscal illusion within the population of voters.Specifically,we find that(i)the tax system is more(less)progressive when taxes and public expenditures are perceived less(more),and(ii)an increase in the median voter’s income may positively or negatively affect tax progressivity depending on the nature(pessimistic or optimistic)of fiscal illusion.The impact of fiscal illusion on tax pro-gressivity has been validated by econometric analysis.

Role of knowledge economy in managing demand-based environmental Kuznets Curve

Aggregate demand or supply at equilibrium is commonly used as a representative of the macroeconomic activity of an economy whereby aggregate demand denotes the behaviour of individuals and households.However,aggregate demand can also directly affect environmental deterioration via changes in aggregate production.This study tried to explore this relationship,known as the demand-based Environmental Kuznets Curve(Demand EKC)and the role of different knowledge economy indicators.Knowledge economy indicators are proposed to influence consumption patterns,altering the demand EKC that empirical studies have understudied.For this purpose,secondary data for 147 countries were collected from 2008 to 2018,also classified as development-wise.This study found that aggregate demand significantly affects carbon emissions.The long-run results are estimated using the Fully Modified Ordinary Least Square method.Controlling factors like renewable energy consumption,population density,and financial development significantly affect carbon emissions in sample countries.This study has incorporated four pillars of a knowledge-based economy and the results showed that these indicators helped reduce consumption-related CO_(2) emissions.

IAS/IFRS and financial reporting quality:Lessons from the European experience

This paper discusses the effects of the adoption of IAS/IFRS in Europe on the quality of financial reporting.In doing so,it adopts the perspective of stock market investors and focuses on value-relevance research.The adoption of IAS/IFRS in Europe is an example of accounting standardization among countries with different institutional frameworks and enforcement rules.This allows investigating whether,and to what extent,accounting regulation per se can affect the quality of financial reporting and leads to convergence in financial reporting.This is a key issue for standard setting purposes as IAS/IFRS have been adopted in very diverse countries all over the world,and many others are likely to adopt them in the near future.

Can gender predict virological response to standard antiviral therapy for chronic hepatitis C? A retrospective study

Aim:The liver is a sexually dimorphic organ presenting gender differences in its metabolism,functions,enzyme activity,membrane lipid composition and immune response.This paper aimed to assess whether gender may predict virological response to standard antiviral therapy in subjects with chronic hepatitis C(CHC).Methods:The authors retrospectively analyzed 100 patients with genotype 1 CHC(55 men,45 women),who performed standard antiviral therapy(interferon and ribavirin for 12 months)in the period 2002-2012,evaluated with blood tests and abdominal ultrasound to compare different virological and biochemical response in both gender.Results:Rate of substained virological response(SVR)was higher,but not significant,in women than men(46.7%vs.34.5%,P=0.05);difference became significant after stratification by age(<50 and≥50 years).Specifically in the group aged under 50 years,rate of SVR was significantly higher in women than in men(66.7%vs.38.2%,P<0.05).Conclusion:Female gender may predict virological response to standard antiviral therapy in subjects with CHC aged below 50 years.Considering new potent and more expensive antiviral drugs actually available for HCV treatment,it could be useful to identify candidates firstly eligible to therapy.