Creating composite indicators with DEA and robustness analysis: The case of the technology achievement index.

Composite indicators are regularly used for benchmarking countries’ performance, but equally often stir controversies about the unavoidable subjectivity that is connected with their construction. Data Envelopment Analysis helps to overcome some key limitations, viz., the undesirable dependence of final results from the preliminary normalization of sub-indicators, and, more cogently, from the subjective nature of the weights used for aggregating. Still, subjective decisions remain, and such modelling uncertainty propagates onto countries’ composite indicator values and relative rankings. Uncertainty and sensitivity analysis are therefore needed to assess robustness of final results and to analyze how much each individual source of uncertainty contributes to the output variance. The current paper reports on these issues, using the Technology Achievement Index as an illustration.Indexes; Indicators; Robustness; Technology;

Bifurcated polarization rotation in bismuth-based piezoelectrics

ABO3 perovskite-type solid solutions display a large variety of structural and physical properties, which can be tuned by chemical composition or external parameters such as temperature, pressure, strain, electric, or magnetic fields. Some solid solutions show remarkably enhanced physical properties including colossal magnetoresistance or giant piezoelectricity. It has been recognized that structural distortions, competing on the local level, are key to understanding and tuning these remarkable properties, yet, it remains a challenge to experimentally observe such local structural details. Here, from neutron pair-distribution analysis, a temperature-dependent 3D atomic-level model of the lead-free piezoelectric perovskite Na0.5Bi0.5TiO3 (NBT) is reported. The statistical analysis of this model shows how local distortions compete, how this competition develops with temperature, and, in particular, how different polar displacements of Bi3+ cations coexist as a bifurcated polarization, highlighting the interest of Bi-based materials in the search for new lead-free piezoelectrics

Effect of slaughter age on meat qualitative traits of veals calves

Scopo del presente lavoro è stato quello di verificare alcune caratteristiche organolettiche e chimico bromatologhe della carne di 15 vitelli di razza Frisona. I vitelli sono stati macellati a 140, 160 e 190 giorni. I parametri analizzati non sono stati significativamente influenzati dall'età di macellazione se non per una riduzione del tenore proteico della sostanza secca a 160 giorni. Pertanto la scelta dell'età di macellazione, per il periodo studiato, può essere fatta sulla base di criteri di natura economica piuttosto che riferita ad aspetti qualitativi della carn

Getting the Measure of the Flatness Problem

The problem of estimating cosmological parameters such as $\Omega$ from noisy or incomplete data is an example of an inverse problem and, as such, generally requires a probablistic approach. We adopt the Bayesian interpretation of probability for such problems and stress the connection between probability and information which this approach makes explicit. This connection is important even when information is ``minimal'' or, in other words, when we need to argue from a state of maximum ignorance. We use the transformation group method of Jaynes to assign minimally--informative prior probability measure for cosmological parameters in the simple example of a dust Friedman model, showing that the usual statements of the cosmological flatness problem are based on an inappropriate choice of prior. We further demonstrate that, in the framework of a classical cosmological model, there is no flatness problem.Comment: 11 pages, submitted to Classical and Quantum Gravity, Tex source file, no figur

Estimating Nuisance Parameters in Inverse Problems

Many inverse problems include nuisance parameters which, while not of direct interest, are required to recover primary parameters. Structure present in these problems allows efficient optimization strategies - a well known example is variable projection, where nonlinear least squares problems which are linear in some parameters can be very efficiently optimized. In this paper, we extend the idea of projecting out a subset over the variables to a broad class of maximum likelihood (ML) and maximum a posteriori likelihood (MAP) problems with nuisance parameters, such as variance or degrees of freedom. As a result, we are able to incorporate nuisance parameter estimation into large-scale constrained and unconstrained inverse problem formulations. We apply the approach to a variety of problems, including estimation of unknown variance parameters in the Gaussian model, degree of freedom (d.o.f.) parameter estimation in the context of robust inverse problems, automatic calibration, and optimal experimental design. Using numerical examples, we demonstrate improvement in recovery of primary parameters for several large- scale inverse problems. The proposed approach is compatible with a wide variety of algorithms and formulations, and its implementation requires only minor modifications to existing algorithms.Comment: 16 pages, 5 figure

Tracing a relativistic Milky Way within the RAMOD measurement protocol

Advancement in astronomical observations and technical instrumentation implies taking into account the general relativistic effects due the gravitational fields encountered by the light while propagating from the star to the observer. Therefore, data exploitation for Gaia-like space astrometric mission (ESA, launch 2013) requires a fully relativistic interpretation of the inverse ray-tracing problem, namely the development of a highly accurate astrometric models in accordance with the geometrical environment affecting light propagation itself and the precepts of the theory of measurement. This could open a new rendition of the stellar distances and proper motions, or even an alternative detection perspective of many subtle relativistic effects suffered by light while it is propagating and subsequently recorded in the physical measurements.Comment: Proceeding for "Relativity and Gravitation, 100 Years after Einstein in Prague" to be published by Edition Open Access, revised versio

Mortality impact of AIDS in Abidjan, 1986-1992

To quantify the mortality impact of AIDS in the city of Abidjan (Côte d'Ivoire) by a full scale analysis of mortality trends before and after the onset of the epidemic. Data on deaths registered in the 10 vital registration centers of the city between 1973 and 1992, and data on causes of deaths in the four public hospitals were coded and investigated. Data on deaths were compared with census data in order to compute death rates. Life tables were computed for each of the 20 years of the study. The trends in death rates were analysed during the 10 years before the onset of the AIDS epidemic (1973-1982) and compared with the changing death rates in the following 10 years (1983-1992). Deaths attributable to AIDS were defined as those in excess of the original trends. The evolution in the number of deaths in the hospital allowed an analysis by cause of death. There was a marked increase in death rates starting in 1986, date of the first diagnosed AIDS cases in the city. This increase was significant for both sexes, but more pronounced among men. It was concentrated primarily among young adults (aged 25-44 years) and among older children (aged 5-14 years), and most of it was considered to be attributable to AIDS and related infections, tuberculosis in particular. When data were cumulated from 1986 to 1992, approximately 25000 persons were estimated to have died of AIDS. The high number of AIDS deaths estimated in Abidjan underlines the heavy toll already paid by african populations, and calls for intensive action. (Résumé d'auteur

Self-perceived barriers to eye care in a hard-to-reach population: The Karachi marine fishing communities eye and general health survey

Abstract Purpose.: We examined self-reported barriers to eye care among marginalized, hard-to-reach fishing communities in Karachi, Pakistan. Methods.: The Karachi Marine Fishing Communities Eye and General Health Survey was a cross-sectional survey conducted between March 2009 and April 2010 in fishing communities in Keamari, Karachi, located on the coast of the Arabian Sea. Adults aged ≥50 years living on seven islands and coastal areas were interviewed regarding sociodemographic background, experience of eye problems, eye care use, and barriers to access. They also were examined to determine visual acuity with a reduced logMAR chart and underwent a detailed eye examination. Results.: Of 700 people planned to be included in the study, 638 (91.1%) were interviewed and examined. Of these participants, 599 (93.9%) lived in extreme poverty and 84.3% had no school-based education, and 349 (54.7%; 95% confidence interval [CI], 50.8–58.6) of them had never had an eye examination. The common barriers to access identified included a perceived lack of or low need (176/349 or 50.4%), financial hardships (36.4%), “fears” (8.6%), and social support constraints (6.3%). Of those reporting a “lack of need,” 21.9% had significant visual loss. Financial hardships, “fears,” and social support constraints were more prevalent among women than men. Bengalis compared to Kutchis and Sindhis, and individuals with “poor/fragile” household financial status (self-reported) compared to those with “fine” status, were more likely to cite financial hardships. Conclusions.: Access to eye care in this marginalized population is substantially hindered by perceived lack of need, financial hardships, and a range of “fears” and anxieties, despite a large unmet need. These barriers should be addressed while paying particular attention to gender, and ethnic and socioeconomic differences

Effects of low doses of dexamethasone on productive traits and meat quality of veal calves

An experimental administration of dexamethasone was carried out on 15 veal calves in order to assess the rôle of low doses of exogenous glucocorticoids on productive traits and meat quality. Three groups, of five veal calves each, were formed : one group received oral dexamethasone (0.4 mg per calf per day for 25 days), another intramuscular (i. m.) dexamethasone (2 mg at days 14 and 21), and the third was the control. Calves were slaughtered at 165 days of age (day 31). Food conversion ratio (FCR), hot dressing percentage (HDP), chilled dressing percentage (CDP) and shrinkage were determined. From all carcasses, samples of m. longissimus thoracis (between the 8th and 10th rib) were taken in order to evaluate the chemical composition and some organoleptic characteristics : meat colour, water-holding capacity and tenderness. The animals treated with oral dexamethasone showed the lowest daily weight gain (P < 0.05) and the poorest FCR (P < 0.05). Hot dressing percentage, cold dressing percentage and shrinkage were not affected by the oral treatment. The i. m. injections of dexamethasone did not influence the overall performance. Muscle chemical composition and pH were not affected by the treatments; the meat of calves treated with oral dexamethasone was significantly lighter (P < 0.05) and tended to be paler, while i. m. treatment induced intermediate characteristics. The shear force of the meat was rather low. Shear force of cooked meat from animals treated with dexamethasone (both oral and i. m.) was significantly lower than the control (P < 0.05). Treatment with dexamethasone i. m. induced a decrease in water-holding capacity; the oral treatment had no effect on this parameter