Earth matter density uncertainty in atmospheric neutrino oscillations

That muon neutrinos $\nu_{\mu}$ oscillating into the mixture of tau neutrinos $\nu_{\tau}$ and sterile neutrinos $\nu_{s}$ has been studied to explain the atmospheric $\nu_{\mu}$ disappearance. In this scenario, the effect of Earth matter is a key to determine the fraction of $\nu_{s}$. Considering that the Earth matter density has uncertainty and this uncertainty has significant effects in some neutrino oscillation cases, such as the CP violation in very long baseline neutrino oscillations and the day-night asymmetry for solar neutrinos, we study the effects caused by this uncertainty in the above atmospheric $\nu_{\mu}$ oscillation scenario. We find that this uncertainty seems to have no significant effects and that the previous fitting results need not to be modified fortunately.Comment: 7 pages, 1 figure, to appear in Phys. Rev.

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

An inverse method to interpret colour-magnitude diagrams

An inverse method is developed to determine the star formation history, the age-metallicity relation, and the IMF slope from a colour-magnitude diagram. The method is applied to the Hipparcos HR diagram. We found that the thin disk of our Galaxy shows a peak of stellar formation 1.6 Gyr ago. The stars close to the Sun have a solar metallicity and a mean IMF index equal to 3.2. However, the model and the evolutionary tracks do not correctly reproduce the horizontal giant branch.Comment: 14 pages, 11 figures. To be published in Astronomy & Astrophysic

A systematic review of epidemiological literature on the eye health of marginalized fishing populations

Abstract A systematic review was conducted in December 2013 to examine the extent to which health research has been focused on the eyehealth issues of fishing communities. We searched multiple databases to identify relevant citations, using a combination of Medical Subject Headings (MeSH) and text words representing eye health, fishing populations and measures of disease frequency. The search yielded only 4 studies, described in 5 articles. Three studies (one each in Turkey, Egypt and Spain) provided data on self-reported eye problems in fishermen or fishery workers, with prevalence ranging from 38% to 81%. There was only one study in the literature that objectively assessed the burden and causes of vision impairment and blindness in fishing communities. None of the studies examined availability, accessibility, acceptability and quality of eye care services. We conclude that marginalized fishing communities are almost non-existent in eye health literature. Eye health needs of these and other marginalized populations must be identified and addressed in post-2015 health and development agenda

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

Conséquences démographiques du sida en Abidjan : 1986-1992

Les statistiques de l'état civil et des formations sanitaires sont notoirement peu utilisées en Afrique pour étudier les tendances de la mortalité. L'étude d'Abidjan montre que c'est une situation très regrettable, car ces statistiques peuvent fournir de précieux renseignements sur l'état sanitaire de la population. Dans le cas présent, l'analyse fine des tendances de la mortalité, couplée avec l'analyse des causes de décès dans les hôpitaux, révèle assez précisément les conséquences démographiques du sida dans la capitale de la Côte d'Ivoire, malgré l'imperfection des données. Les estimations indiquent que près de 25 000 personnes seraient décédées du sida entre 1986 et 1992, les sept premières années de l'épidémie, ce qui confirme qu'Abidjan est une des villes les plus touchées au monde par cette troublante épidémie. Ce sont surtout les jeunes de sexe masculin qui ont été les plus touchés, dans toutes les couches de la société. Un modèle a permis de reconstruire la dynamique de l'épidémie, qui montre que le premier pic des infections se serait produit vers 1987. On peut s'attendre à une moyenne d'environ 7 000 cas de sida par an dans la ville jusqu'à l'an 2000, ce qui aura des conséquences importantes sur l'utilisation des infrastructures hospitalières. L'importance numérique de ces estimations souligne l'urgence de renforcer la lutte contre l'épidémie de sida en Côte d'Ivoire et dans le monde. (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