Cool carbon stars in the halo and in dwarf galaxies: Halpha, colours, and variabiity

The population of cool carbon (C) stars located far from the galactic plane is probably made of debris of small galaxies such as the Sagittarius dwarf spheroidal galaxy (Sgr), which are disrupted by the gravitational field of the Galaxy. We aim to know this population better through spectroscopy, 2MASS photometric colours, and variability data. When possible, we compared the halo results to C star populations in the Fornax dwarf spheroidal galaxy, Sgr, and the solar neighbourhood. We first present a few new discoveries of C stars in the halo and in Fornax. The number of spectra of halo C stars is now 125. Forty percent show Halpha in emission. The narrow location in the JHK diagram of the halo C stars is found to differ from that of similar C stars in the above galaxies. The light curves of the Catalina and LINEAR variability databases were exploited to derive the pulsation periods of 66 halo C stars. A few supplementary periods were obtained with the TAROT telescopes. We confirm that the period distribution of the halo strongly resembles that of Fornax, and we found that is it very different from the C stars in the solar neighbourhood. There is a larger proportion of short period Mira/SRa variables in the halo than in Sgr, but the survey for C stars in this dwarf galaxy is not complete, and the study of their variability needs to be continued to investigate the link between Sgr and the cool halo C stars.Comment: 11 pages, 10 figures + one appendix of 26 pages; accepted for publication in Astronomy and Astrophysic

Multiple recombinant dengue type 1 viruses in an isolate from a dengue patient

Between 2000 and 2004, dengue virus type 1 (DENV-1) genotypes I and II from Asia were introduced into the Pacific region and co-circulated in some localities. Envelope protein gene sequences of DENV-1 from 12 patients infected on the island of New Caledonia were obtained, five of which carried genotype I viruses and six, genotype II viruses. One patient harboured a mixed infection, containing viruses assigned to both genotypes I and II, as well as a number of inter-genotypic recombinants. This is the first report of a population of dengue viruses isolated from a patient containing both parental and recombinant viruses

Isolation of Trichophyton concentricum from chronic cutaneous lesions in patients from the Solomon Islands

Tinea imbricata, also known as ‘Tokelau’, is an uncommon superficial mycosis caused by the anthropophilic dermatophyte Trichophyton concentricum. Cutaneous lesions appear characteristically as scaly and concentric rings that may cover all parts of the body. Often acquired in childhood, tinea imbricata is a chronic disease and lichenification is extremely common due to pruritus. The dermatophytosis mainly occurs in the South Pacific, but also in some regions of Southeast Asia and Central or South America. Tinea imbricata usually affects people living in primitive and isolated conditions. Mycological analysis is required for the diagnosis. The epidemiological and mycological study reported here took place in the Solomon Islands from June–September 2006. Skin scrapings were collected from 29 Melanesian patients (aged 8 months to 58 years) with chronic cutaneous lesions and were analysed mycologically in the Laboratory of Parasitology and Mycology of Angers University Hospital (France). Ten patients showed very evocative lesions with a positive direct examination, but T. concentricum was only isolated from three patients. Identification of the strains was confirmed by sequencing of the internal transcribed spacer (ITS) regions. With the increase in international travel, one cannot disregard that this very rare species may be isolated by mycologists in temperate areas from patients coming from endemic foci

Infectious Etiologies of Acute Febrile Illness among Patients Seeking Health Care in South-Central Cambodia

The agents of human febrile illness can vary by region and country suggesting that diagnosis, treatment, and control programs need to be based on a methodical evaluation of area-specific etiologies. From December 2006 to December 2009, 9,997 individuals presenting with acute febrile illness at nine health care clinics in south-central Cambodia were enrolled in a study to elucidate the etiologies. Upon enrollment, respiratory specimens, whole blood, and serum were collected. Testing was performed for viral, bacterial, and parasitic pathogens. Etiologies were identified in 38.0% of patients. Influenza was the most frequent pathogen, followed by dengue, malaria, and bacterial pathogens isolated from blood culture. In addition, 3.5% of enrolled patients were infected with more than one pathogen. Our data provide the first systematic assessment of the etiologies of acute febrile illness in south-central Cambodia. Data from syndromic-based surveillance studies can help guide public health responses in developing nations

Leptospirosis in American Samoa – Estimating and Mapping Risk Using Environmental Data

Leptospirosis is the most common bacterial infection transmitted from animals to humans. Infected animals excrete the bacteria in their urine, and humans can become infected through contact with animals or a contaminated environment such as water and soil. Environmental factors are important in determining the risk of human infection, and differ between ecological settings. The wide range of risk factors include high rainfall and flooding; poor sanitation and hygiene; urbanisation and overcrowding; contact with animals (including rodents, livestock, pets, and wildlife); outdoor recreation and ecotourism; and environmental degradation. Predictive risk maps have been produced for many infectious diseases to identify high-risk areas for transmission and guide allocation of public health resources. Maps are particularly useful where disease surveillance and epidemiological data are poor. The objectives of this study were to estimate leptospirosis seroprevalence at geographic locations based on environmental factors, produce a predictive disease risk map for American Samoa, and assess the accuracy of the maps in predicting infection risk. This study demonstrated the value of geographic information systems and disease mapping for identifying environmental risk factors for leptospirosis, and enhancing our understanding of disease transmission. Similar principles could be used to investigate the epidemiology of leptospirosis in other areas

Temporal and thematic trends in water, sanitation and hygiene (WaSH) research in Pacific Island Countries: a systematic review

Pacific Island Countries (PICs) lag behind global trends in water, sanitation and hygiene (WaSH) development. We conducted a systematic search of all English language papers (published before February 2015) about WaSH in PICs to evaluate the state of the peer-reviewed literature and explore thematic findings. A total of 121 papers met the criteria for full-text review following an initial search result of more than 6,000 papers. Two reviewers independently assessed the quality and relevance of each article and consolidated their findings according to four emergent themes: public health, environment, emergency response and interventions, and management and governance. Findings indicate a knowledge gap in evidence-guided WaSH management strategies that advocate for human health while concurrently protecting and preserving drinking water resources. Extreme weather events threaten the quantity and quality of limited freshwater resources, and cultural factors that are unique to PICs present challenges to hygiene and sanitation. This review highlights the strengths and weaknesses of the peer-reviewed literature on WaSH in PICs, addresses spatial and temporal publication trends, and suggests areas in need of further research to help PICs meet development goals

Leptospirosis in the Asia Pacific region

<p>Abstract</p> <p>Background</p> <p>Leptospirosis is a worldwide zoonotic infection that has been recognized for decades, but the problem of the disease has not been fully addressed, particularly in resource-poor, developing countries, where the major burden of the disease occurs. This paper presents an overview of the current situation of leptospirosis in the region. It describes the current trends in the epidemiology of leptospirosis, the existing surveillance systems, and presents the existing prevention and control programs in the Asia Pacific region.</p> <p>Methods</p> <p>Data on leptospirosis in each member country were sought from official national organizations, international public health organizations, online articles and the scientific literature. Papers were reviewed and relevant data were extracted.</p> <p>Results</p> <p>Leptospirosis is highly prevalent in the Asia Pacific region. Infections in developed countries arise mainly from occupational exposure, travel to endemic areas, recreational activities, or importation of domestic and wild animals, whereas outbreaks in developing countries are most frequently related to normal daily activities, over-crowding, poor sanitation and climatic conditions.</p> <p>Conclusion</p> <p>In the Asia Pacific region, predominantly in developing countries, leptospirosis is largely a water-borne disease. Unless interventions to minimize exposure are aggressively implemented, the current global climate change will further aggravate the extent of the disease problem. Although trends indicate successful control of leptospirosis in some areas, there is no clear evidence that the disease has decreased in the last decade. The efficiency of surveillance systems and data collection varies significantly among the countries and areas within the region, leading to incomplete information in some instances. Thus, an accurate reflection of the true burden of the disease remains unknown.</p

Mira Variables explained by a planetary companion interaction: A means to drop the pulsation paradigm?

We emphasize the limits of the classical paradigm explaining the periodic appearance of emission lines by shock waves induced by radial periodic pulsations. In particular, we argue that, if pulsation occurs, it would not be purely radial and the light curve resulting from the contribution of zones at different phases would have a shape different from what we actually observe. The discovery of low mass companions to numerous G stars, some of them very close to the star, led us to look at the fate and the influence of this companion when the star becomes a giant. After Rudnitskij 2000), we suggest that the behavior of the Mira variables is mainly due to the presence of a companion in the tenuous atmosphere of the giant instead of the effect of a pulsating atmosphere explaining the presence of emission lines and the periodicity of these variables. We argue that the presence of a companion may account for the shape of the light curve and the observed phase lag between the maximum visual and the maximum maser light

Spectral synthesis with Synspec applied to static and dynamic models of cool objects


Miras and Semi-Regular variables are, among Red Giants, cool objects which are difficult to understand. This paper presents an adaptation of the spectral synthesis code SYNSPEC to cool objects. Some examples of application of this code to static and dynamical structures are presented.

Observation et modélisation des étoiles variables Mira (discussion des mécanismes en jeu)

Les étoiles de type Mira, situées sur la branche asymptotique des géantes, présentent une variabilité de 2 à 8 magnitudes sur une période de 150 à 500 jours. Ces objets restent à ce jour mal compris et malgré de très nombreuses tentatives résistent à une description cohérente. L'idée générale qui s'est imposée repose sur une pulsation radiale de ces objets qui engendrerait des ondes de choc et serait à la fois responsable de la variabilité et de l'apparition de raies d'émission. Je réalise d'abord une synthèse de nombreux travaux de la littérature. Puis je présente des résultats de mesure en interférométrie des tavelures de la Mira Chi Cygni et les compare à ceux d'autres auteurs. Je présente ensuite des spectres de la même Mira à différentes phases de sa courbe de lumière qui montrent une grande variété de profils des raies en fonction de la phase, de l'élément et du niveau d'excitation. L'étape suivante est l'étude théorique et la mise au point pratique d'un modèle hydrodynamique et radiatif à deux dimensions d'espace. Les résultats de ce modèle sont injectés dans un modèle de calcul de spectre synthétique que j'ai adapté pour la prise en compte des très nombreuses raies moléculaires présentes dans les étoiles froides. J'aborde ensuite l'interprétation des données d'observation par la propagation d'un choc dans l'atmosphère de ces étoiles et par la théorie de la pulsation de ces étoiles. La complexité du problème est telle qu'il n'existe pas de modèle auto-cohérent. Je présente donc successivement la pulsation de la structure et son effet sur l'atmosphère simulé par un piston. Force est de constater que la théorie de la pulsation et ses effets prévisibles sur l'atmosphère sont contredits par plusieurs arguments théoriques et observationnels. Je propose que les phénomènes observés aient pour origine la perturbation d'un compagnon dans l'atmosphère ténue de ces objets et tente de tirer les conséquences de cette présence et les limites de cette hypothèse.LYON1-BU.Sciences (692662101) / SudocSudocFranceF