216 research outputs found

    Hi-fi phenomenological description of eclipsing binary light variations as the basis for their period analysis

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    In-depth analysis of eclipsing binary (EB) observational data collected for several decades can inform us about a lot of astrophysically interesting processes taking place in the systems. We have developed a wide-ranging method for the phenomenological modelling of eclipsing binary phase curves that enables us to combine even very disparate sources of phase information. This approach is appropriate for the processing of both standard photometric series of eclipses and data from photometric surveys of all kind. We conclude that mid-eclipse times, determined using the latest version of our 'hi-fi' phenomenological light curve models, as well as their accuracy, are nearly the same as the values obtained using much more complex standard physical EB models.Comment: 4 pages, 3 figures, EAS - Proceedings of the conference: Setting a new standard in the analysis of binary stars, 16 to 19 September 2013, Leuven, Belgiu

    CCD photometric study of the W UMa-type binary II CMa in the field of Berkeley 33

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    The CCD photometric data of the EW-type binary, II CMa, which is a contact star in the field of the middle-aged open cluster Berkeley 33, are presented. The complete R light curve was obtained. In the present paper, using the five CCD epochs of light minimum (three of them are calculated from Mazur et al. (1993)'s data and two from our new data), the orbital period P was revised to 0.22919704 days. The complete R light curve was analyzed by using the 2003 version of W-D (Wilson-Devinney) program. It is found that this is a contact system with a mass ratio q=0.9q=0.9 and a contact factor f=4.1f=4.1%. The high mass ratio (q=0.9q=0.9) and the low contact factor (f=4.1f=4.1%) indicate that the system just evolved into the marginal contact stage

    Comparing Enterovirus 71 with Coxsackievirus A16 by analyzing nucleotide sequences and antigenicity of recombinant proteins of VP1s and VP4s

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    <p>Abstract</p> <p>Background</p> <p>Enterovirus 71 (EV71) and Coxsackievirus A16 (CA16) are two major etiological agents of Hand, Foot and Mouth Disease (HFMD). EV71 is associated with severe cases but not CA16. The mechanisms contributed to the different pathogenesis of these two viruses are unknown. VP1 and VP4 are two major structural proteins of these viruses, and should be paid close attention to.</p> <p>Results</p> <p>The sequences of <it>vp1s </it>from 14 EV71 and 14 CA16, and <it>vp4s </it>from 10 EV71 and 1 CA16 isolated in this study during 2007 to 2009 HFMD seasons were analyzed together with the corresponding sequences available in GenBank using DNAStar and MEGA 4.0. Phylogenetic analysis of complete <it>vp1s </it>or <it>vp4s </it>showed that EV71 isolated in Beijing belonged to C4 and CA16 belonged to lineage B2 (lineage C). VP1s and VP4s from 4 strains of viruses expressed in <it>E. coli BL21 </it>cells were used to detect IgM and IgG in human sera by Western Blot. The detection of IgM against VP1s of EV71 and CA16 showed consistent results with current infection, while none of the sera were positive against VP4s of EV71 and CA16. There was significant difference in the positive rates between EV71 VP1 and CA16 VP1 (χ<sup>2 </sup>= 5.02, P < 0.05) as well as EV71 VP4 and CA16 VP4 (χ<sup>2 </sup>= 15.30, P < 0.01) in the detection of IgG against recombinant proteins with same batch of serum samples. The sera-positive rate of IgG against VP1 was higher than that against VP4 for both EV71 (χ<sup>2 </sup>= 26.47, P < 0.01) and CA16 (χ<sup>2 </sup>= 16.78, P < 0.01), which might be because of different positions of VP1 and VP4 in the capsid of the viruses.</p> <p>Conclusions</p> <p>EV71 and CA16 were highly diverse in the nucleotide sequences of <it>vp1s </it>and <it>vp4s</it>. The sera positive rates of VP1 and VP4 of EV71 were lower than those of CA16 respectively, which suggested a less exposure rate to EV71 than CA16 in Beijing population. Human serum antibodies detected by Western blot using VP1s and VP4s as antigen indicated that the immunological reaction to VP1 and VP4 of both EV71 and CA16 was different.</p

    Wavelength Dependence of Solar Irradiance Enhancement During X-Class Flares and Its Influence on the Upper Atmosphere

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    The wavelength dependence of solar irradiance enhancement during flare events is one of the important factors in determining how the Thermosphere-Ionosphere (T-I) system responds to flares. To investigate the wavelength dependence of flare enhancement, the Flare Irradiance Spectral Model (FISM) was run for 61 X-class flares. The absolute and the percentage increases of solar irradiance at flare peaks, compared to pre-flare conditions, have clear wavelength dependences. The 0-14 nm irradiance increases much more (approx. 680% on average) than that in the 14-25 nm waveband (approx. 65% on average), except at 24 nm (approx. 220%). The average percentage increases for the 25-105 nm and 122-190 nm wavebands are approx. 120% and approx. 35%, respectively. The influence of 6 different wavebands (0-14 nm, 14-25 nm, 25-105 nm, 105- 120 nm, 121.56 nm, and 122-175 nm) on the thermosphere was examined for the October 28th, 2003 flare (X17-class) event by coupling FISM with the National Center for Atmospheric Research (NCAR) Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) under geomagnetically quiet conditions (Kp=1). While the enhancement in the 0-14 nm waveband caused the largest enhancement of the globally integrated solar heating, the impact of solar irradiance enhancement on the thermosphere at 400 km is largest for the 25-105 nm waveband (EUV), which accounts for about 33 K of the total 45 K temperature enhancement, and approx. 7.4% of the total approx. 11.5% neutral density enhancement. The effect of 122-175 nm flare radiation on the thermosphere is rather small. The study also illustrates that the high-altitude thermospheric response to the flare radiation at 0-175 nm is almost a linear combination of the responses to the individual wavebands. The upper thermospheric temperature and density enhancements peaked 3-5 h after the maximum flare radiation

    Predictive value of controlling nutritional status score for prostate cancer diagnosis

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    ObjectiveThis study aims to explore the predictive value of the Controlling Nutritional Status (CONUT) score for prostate cancer (PCa) diagnosis.MethodsThe data of 114 patients who underwent prostate needle biopsies from June 2020 to December 2022 were retrospectively analyzed. The relationship between CONUT score and various clinical factors as well as PCa diagnosis was evaluated.ResultsThe pathological results classified patients into the PCa (n = 38) and non-PCa (n = 76) groups. Compared with the non-PCa group, the PCa group exhibited statistically significant differences in age, prostate-specific antigen (PSA), PSA density (PSAD), the proportion of PI-RADS ≥ 3 in mpMRI, and the CONUT score, prostate volume, lymphocyte count, and total cholesterol concentration (p &lt; 0.05). ROC curve analyses indicated the diagnostic accuracy as follows: age (AUC = 0.709), prostate volume (AUC = 0.652), PSA (AUC = 0.689), PSAD (AUC = 0.76), PI-RADS ≥ 3 in mpMRI (AUC = 0.846), and CONUT score (AUC = 0.687). When CONUT score was combined with PSA and PSAD, AUC increased to 0.784. The AUC of CONUT score combined with PSA, PSAD, and mpMRI was 0.881, indicates a higher diagnostic value. Based on the optimal cut-off value of CONUT score, compared with the low CONUT score group, the high CONUT score group has a higher positive rate of PCa diagnosis (p &lt; 0.05).ConclusionCONUT score is an excellent auxiliary index for PCa diagnosis in addition to the commonly used PSA, PSAD, and mpMRI in clinical practice. Further prospective trials with a larger sample size are warranted to confirm the present study findings
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