In this paper, we revisit the problem of the determination of the frequency of occurrence of galactic nova outbursts which involve an oxygen-neon (ONe) white dwarf. The improvement with respect to ...previous work on the subject derives from the fact that we use the results that our evolutionary calculations provide for the final mass and for the chemical profiles of intermediate-to-massive primary components of close binary systems. In particular, the final evolutionary stages, such as the carbon burning phase, have been carefully followed for the whole range of masses of interest. The chemical profiles obtained with our evolutionary code are of interest in determining the chemical composition of the ejecta after being processed through the thermonuclear runaway, although such other factors as the efficiency of the mixing between the accreted material and that of the underlying white dwarf must also be considered. In our calculations of the frequency of occurrence of nova outbursts involving an ONe white dwarf, we also take into account the observational selection effects introduced by the different recurrence times of the outbursts and by the spatial distribution of novae. In spite of the very different evolutionary sequences, we find that approximately 1/3 of the observed nova outbursts should involve an oxygen-neon white dwarf, in agreement with previous theoretical estimates.
The Bidirectional Reflectance Distribution Function (BRDF) is essential to characterize an object's reflectance properties. This function depends both on the various illumination-observation ...geometries as well as on the wavelength. As a result, the comprehensive interpretation of the data becomes rather complex. In this work we assess the use of the multivariable analysis technique of Principal Components Analysis (PCA) applied to the experimental BRDF data of a ceramic colour standard. It will be shown that the result may be linked to the various reflection processes occurring on the surface, assuming that the incoming spectral distribution is affected by each one of these processes in a specific manner. Moreover, this procedure facilitates the task of interpolating a series of BRDF measurements obtained for a particular sample.
The evolution of the soft X-ray emission of V1974 Cyg has been simulated by a white dwarf envelope model with steady hydrogen burning. The comparison of the results obtained from ROSAT observations ...with the results of our envelope models indicates that the post-outburst evolution of the nova can be explained by steady H-burning on either a 0.9 $M_{\odot }$ white dwarf with 50% degree of mixing between solar-like accreted material and the ONe degenerate core, or on a 1.0 $M_{\odot}$ ONe white dwarf with 25% mixing.
•Patients presenting with cancer should benefit from vaccines as they are exposed to a heightened risk of invasive pneumococcal diseases (IPD) and influenza illness, leading to an increased risk of ...morbi-mortality.•Cancer patients are under vaccinated against the two main frequent and threatening diseases (IPD and the flu) with vaccination coverage of 7.2% and 28.6%, respectively.•Factors associated with appropriate vaccination in oncology and hematology include age ≥65 years, information received from family physicians, being treated for an hematological malignancy, and having a positive opinion about vaccination.
Chemotherapy increases the risk of infections, often severe, and some of them are vaccine-preventable infections. We aimed to assess vaccination coverage and associated factors in oncology and hematology patients.
Consecutive adult patients followed in a French university hospital for hematological malignancy or solid cancer voluntarily completed an anonymous questionnaire in September and October 2016. It included questions on underlying disease, chemotherapy, flu, and pneumococcal vaccination uptakes, and attitudes toward vaccination. Factors associated with vaccination uptake were assessed by multivariate logistic regression.
The response rate was 41.9% (N=671) among 1,600 questionnaires distributed; 232 patients had underlying hematological malignancy and 439 had solid cancer. Half of the patients were aged over 65 years. Chemotherapy was ongoing or discontinued for less than one year in 74.7% of patients. In patients aged <65 years undergoing chemotherapy, flu vaccination rate was 19.9% whereas patients aged >65 years had coverage of 47%. Pneumococcal vaccine uptake was 7.3%. However, 64.7% of patients were favorable to vaccination. Vaccine uptake was associated with age >65 years (OR 4.5 2.9–7.0), information about vaccination delivered by the family physician (OR 12.9 5.5–30.1), follow-up in hematology unit (OR 2.0 1.3–3.1), and positive opinion about vaccination (OR 2.0 1.3–3.1).
Despite specific recommendations regarding immunocompromised patients, anti-pneumococcal and flu vaccinations were rarely conducted, even in elderly patients. Targeted information campaigns to family physicians, oncologists, and patients should be implemented to improve vaccine coverage in patients with underlying malignancies.
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