Multiferroicity in V-doped PbTiO3_{3}

We report \emph{ab initio} predictions on the proper multiferroic (ferromagnetic, insulating and ferroelectric) character of PbTiO$_{3}$ doped with vanadium. V impurities coupled ferromagnetically carry a magnetization of 1 $\mu_{\rm B}$ each. The coupling is expected to be strong, since the paramagnetic solution is higher by 150 meV/vanadium, and no stable antiferromagnetic solution was found. The electronic gap in the doped system is about 0.2-0.3 eV in GGA, hence the system is properly multiferroic. V doping increases the spontaneous polarization in PbTiO$_{3}$, with an approximate percentual rate of 0.7 $\mu$C/cm$^{2}$.Comment: 4 pages, 3 figures, 1 tabl

Determinants of Public Health Outcomes: A Macroeconomic Perspective

This paper investigates the nature of the aggregate production function of health services. We build a model to analyze the role of public policy in determining social health outcomes, taking into account households choices concerning education, health related expenditures and saving. In the model, education has a positive external effect on health outcomes. Next, we perform an empirical analysis using a data set covering 80 countries from 1961 to 1995. We find strong evidence for a dual role of education as a determinant of health outcomes. In particular, we find that society’s tertiary education attainment levels contribute positively to how many years an individual should expect to live, in addition to the role that basic education plays for life expectancy at the individual household level. This finding uncovers a key externality of the educational sector on the ability of society to take advantage of best practices in the health service sector.Education, life expectancy, external effects, absorptive capacity.

Optimal Growth when Environmental Quality is a Research Asset

If environmental quality positively affects the productivity of labor in R&D and pollution is caused by the use of a non-renewable resource, it is socially optimal to postpone extraction and to intertemporally adjust R&D effort.endogenous growth; non-renewable resources; environmental quality

Longevity and Education: A Macroeconomic Perspective

This paper investigates the determinants of longevity at a macroeconomic level, emphasizing the important role played by education. To analyze the determinants of longevity, we build a model where households intentionally invest in health and education, and where education exerts external effects on longevity. Performing an empirical analysis using data across 71 countries, we find that society’s tertiary education attainment rate is important for longevity, in addition to any role that basic education plays for life expectancy at the individual level. This finding uncovers a key externality of education, consistent with the theoretical hypothesis advanced in our macroeconomic model.Education, life expectancy, health, externalities, absorptive capacity, welfare

Cardiac hypertrophy and heart failure: from the case to review of literature

In response to an increased workload due to physiological or pathological stimuli, the heart may undergo a process of growth with increased muscle mass called cardiac hypertrophy. It is a particular mechanism of long term compensation used by the heart to adapt permanently to a greater workload. Although, through its peculiar structural, molecular and metabolic characteristics, in early stage the hypertrophy allows to maintain an adequate cardiac function, after a variable period of time, the same characteristics promote the evolution to contractile dysfunction and heart failure. The latter represents an important cause of death and so the cardiac hypertrophy increases the cardiovascular morbidity and mortality. In this paper we report a rare case of extremely high degree of concentric cardiac hypertrophy, with a heart weight of 1050 g and longitudinal diameter of 16.5 cm, transverse diameter of 16 cm and antero-posterior diameter of 9 cm. The thickness of the left ventricle free wall was 4.2 cm, of the septum 4.3 cm and at the apex level 3.5 cm. These data, compared with those described in scientific literature, indicate the exceptional nature of our necropsy finding of a huge cardiac hypertrophy. The analysis of the pathogenetic mechanisms, which may determinate the fatal event in case of cardiac hypertrophy, shows that in the described case the death cause can be the onset of heart failure in presence of cardiomegaly

Knowledge-aided covariance matrix estimation and adaptive detection in compound-Gaussian noise

We address the problem of adaptive detection of a signal of interest embedded in colored noise modeled in terms of a compound-Gaussian process. The covariance matrices of the primary and the secondary data share a common structure while having different power levels. A Bayesian approach is proposed here, where both the power levels and the structure are assumed to be random, with some appropriate distributions. Within this framework we propose MMSE and MAP estimators of the covariance structure and their application to adaptive detection using the NMF test statistic and an optimized GLRT herein derived. Some results, also conducted in comparison with existing algorithms, are presented to illustrate the performances of the proposed algorithms. The relevant result is that the solutions presented herein allows to improve the performance over conventional ones, especially in presence of a small number of training data

Knowledge-aided Bayesian covariance matrix estimation in compound-Gaussian clutter

We address the problem of estimating a covariance matrix R using K samples zk whose covariance matrices are kR, where k are random variables. This problem naturally arises in radar applications in the case of compound-Gaussian clutter. In contrast to the conventional approach which consists in considering R as a deterministic quantity, a knowledge-aided (KA) approach is advocated here, where R is assumed to be a random matrix with some prior distribution. The posterior distribution of R is derived. Since it does not lead to a closed-form expression for the minimum mean-square error (MMSE) estimate of R, both R and k are estimated using a Gibbs-sampling strategy. The maximum a posteriori (MAP) estimator ofR is also derived. It is shown that it obeys an implicit equation which can be solved through an iterative procedure, similarly to the case of deterministic ks, except that KA is now introduced in the iterative scheme. The new estimators are shown to improve over conventional estimators, especially in small sample support

Adaptive detection of distributed targets in compound-Gaussian noise without secondary data: A Bayesian approach

In this paper, we deal with the problem of adaptive detection of distributed targets embedded in colored noise modeled in terms of a compound-Gaussian process and without assuming that a set of secondary data is available.The covariance matrices of the data under test share a common structure while having different power levels. A Bayesian approach is proposed here, where the structure and possibly the power levels are assumed to be random, with appropriate distributions. Within this framework we propose GLRT-based and ad-hoc detectors. Some simulation studies are presented to illustrate the performances of the proposed algorithms. The analysis indicates that the Bayesian framework could be a viable means to alleviate the need for secondary data, a critical issue in heterogeneous scenarios