326 research outputs found

    Orbital evolution of the Carina dwarf galaxy and self-consistent star formation history determination

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    We present a new study of the evolution of the Carina dwarf galaxy that includes a simultaneous derivation of its orbit and star formation history. The structure of the galaxy is constrained through orbital parameters derived from the observed distance, proper motions, radial velocity and star formation history. The different orbits admitted by the large proper motion errors are investigated in relation to the tidal force exerted by an external potential representing the Milky Way (MW). Our analysis is performed with the aid of fully consistent N-body simulations that are able to follow the dynamics and the stellar evolution of the dwarf system in order to determine self-consistently the star formation history of Carina. We find a star formation history characterized by several bursts, partially matching the observational expectation. We find also compatible results between dynamical projected quantities and the observational constraints. The possibility of a past interaction between Carina and the Magellanic Clouds is also separately considered and deemed unlikely.Comment: Accepted in A&

    Lung cancer mortality in a cohort of workers in a petrochemical plant: occupational or residential risk?

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    Gela area is an Italian polluted site qualifying for remediation because of widespread contamination from a petrochemical complex. This study investigates mortality and morbidity of the cohort of employees in Gela petrochemical plant with the aim of disentangling the health effect of work and residence. Work experience was classified in terms of job title, while an ad hoc mobility model was applied to define qualitative categories of residence in Gela as probable residents and probable commuters. Mortality rate ratio for lung cancer was 1.60 (90% CI 1.01-2.53) in workers probable resindents compared to probable commuters. For the same comparison, Hospital Discharge Prevalence Ratio for COPD was 1.39 (0.94-2.07). The crude categories of work and residence limits the interpretation of the causal nature of the study results. Despite several limitations, the results for respiratory pathologies are compatible with an etiological role of the documented contamination.The purpose of the present study is to examine the role of environmental (non occupational) exposures in lung cancer risk among petrochemical workers at a large petrochemical plant built on the Sicilian coast in the immediate vicinity of the town of Gela, Italy in 1960. The cohort included workers employed in the Gela petrochemical plant in 1960-1993. We looked at mortality rates for the period 1960-2002. An internal comparison was performed between two categories of workers with different likelihood of residence in Gela during the period of employment. The rate ratio of mortality from lung cancer comparing "probable residents" with "possible non residents," adjusted for age, calendar period, andjob classification (only blue collar, only white collar and both), was 1.66 (90% Confidence Interval 1.07-2.58). Although the information collected is quite sparse and no inferences can be made about risk sources, the results show a possible excess of residential/environmental risk from lung cancer mortality for those workers more likely to have been residents in Gela

    Blocking entry of hepatitis B and D viruses to hepatocytes as a novel immunotherapy for treating chronic infections

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    Background. Chronic hepatitis B and D virus (HBV/HDV) infections can cause cancer. Current HBV therapy using nucleoside analogues (NAs) is life-long and reduces but does not eliminate the risk of cancer. A hallmark of chronic hepatitis B is a dysfunctional HBV-specific T-cell response. We therefore designed an immunotherapy driven by naive healthy T cells specific for the HDV antigen (HDAg) to bypass the need for HBV-specific T cells in order to prime PreS1-specific T cells and PreS1 antibodies blocking HBV entry. Methods. Ten combinations of PreS1 and/or HDAg sequences were evaluated for induction of PreS1 antibodies and HBV- and HDV-specific T cells in vitro and in vivo. Neutralization of HBV by PreS1-specific murine and rabbit antibodies was evaluated in cell culture, and rabbit anti-PreS1 were tested for neutralization of HBV in mice repopulated with human hepatocytes. Results. The best vaccine candidate induced T cells to PreS1 and HDAg, and PreS1 antibodies blocking HBV entry in vitro. Importantly, adoptive transfer of PreS1 antibodies prevented, or modulated, HBV infection after a subsequent challenge in humanized mice. Conclusions. We here describe a novel immunotherapy for chronic HBV/HDV that targets viral entry to complement NAs and coming therapies inhibiting viral maturation

    Cancer incidence in Italian contaminated sites

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    INTRODUCTION: The incidence of cancer among residents in sites contaminated by pollutants with a possible health impact is not adequately studied. In Italy, SENTIERI Project (Epidemiological study of residents in National Priority Contaminated Sites, NPCSs) was implemented to study major health outcomes for residents in 44 NPCSs. METHODS: The Italian Association of Cancer Registries (AIRTUM) records cancer incidence in 23 NPCSs. For each NPCSs, the incidence of all malignant cancers combined and 35 cancer sites (coded according to ICD-10), was analysed (1996-2005). The observed cases were compared to the expected based on age (5-year period,18 classes), gender, calendar period (1996-2000; 2001-2005), geographical area (North-Centre and Centre-South) and cancer sites specific rates. Standardized Incidence Ratios (SIR) with 90% Confidence Intervals were computed. RESULTS: In both genders an excess was observed for overall cancer incidence (9% in men and 7% in women) as well as for specific cancer sites (colon and rectum, liver, gallblad-der, pancreas, lung, skin melanoma, bladder and Non Hodgkin lymphoma). Deficits were observed for gastric cancer in both genders, chronic lymphoid leukemia (men), malignant thyroid neoplasms, corpus uteri and connective and soft-tissue tumours and sarcomas (women). DISCUSSION: This report is, to our knowledge, the first one on cancer risk of residents in NPCSs. The study, although not aiming to estimate the cancer burden attributable to the environment as compared to occupation or life-style, supports the credibility of an etiologic role of environmental exposures in contaminated sites. Ongoing analyses focus on the interpretation of risk factors for excesses of specific cancer types overall and in specific NPCSs in relation to the presence of carcinogenic pollutants

    Synthesis of Specimen Preparation and Curing Processes for Cold Recycled Asphalt Mixes

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    The process of cold recycling (CR) is becoming method of choice for pavement rehabilitation due to significantly added environmental and economic benefits. Understanding and standardization of specimen preparation and curing processes are critical to replicate field conditions in lab. This paper presents an extensive synthesis of various specimen preparation and curing processes for cold recycled asphalt mixes. Topics synthesized include RAP, emulsion/bitumen and aggregate preparation, mixing processes, pre- and post- compaction curing, compaction and mechanical testing. This paper was developed through efforts of cold recycling task group (TG6) of RILEM Technical Committee on Testing and Characterization of Sustainable Innovative Bituminous Materials and Systems (TC-SIB)
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