A study of contact binaries with large temperature differencies between components

We present an extensive analysis of new light and radial-velocity (RV) curves, as well as high-quality broadening-function (BF) profiles of twelve binary systems for which a contact configuration with large temperature differencies between components has been reported in the literature. We find that six systems (V1010 Oph, WZ Cyg, VV Cet, DO Cas, FS Lup, V747 Cen) have near-contact configurations. For the remaining systems (CX Vir, FT Lup, BV Eri, FO Hya, CN And, BX And), our solutions of the new observations once again converge in a contact configuration with large temperature differencies between the components. However, the bright regions discovered in the BFs for V747 Cen, CX Vir, FT Lup, BV Eri, FO Hya, and CN And, and further attributed to hot spots, shed new light on the physical processes taking place between the components and imply the possibility that the contact configurations obtained from light- and RV-curve modelling are a spurious result.Comment: Submited to Acta Astronomic

A photometric and spectroscopic study of WW And - an Algol-type, long period binary system with an accretion disc

We have analyzed the available spectra of WW And and for the first time obtained a reasonably well defined radial velocity curve of the primary star. Combined with the available radial velocity curve of the secondary component, these data led to the first determination of the spectroscopic mass ratio of the system at q-spec = 0.16 +/- 0.03. We also determined the radius of the accretion disc from analysis of the double-peaked H-alpha emission lines. Our new, high-precision, Johnson VRI and the previously available Stromgren vby light curves were modelled with stellar and accretion disc models. A consistent model for WW And - a semidetached system harbouring an accretion disc which is optically thick in its inner region, but optically thin in the outer parts - agrees well with both spectroscopic and photometric data.Comment: Accepted by New Astronom

The Effect of Dairy Cattle Housing Systems on the Concentrations and Emissions of Gaseous Mixtures in Barns Determined by Fourier-Transform Infrared Spectroscopy

The aim of this study was to determine the concentrations and emissions of greenhouse and odorous gases in different types of dairy cattle housing systems with the use of Fourier-transform infrared (FTIR) spectroscopy. The study was performed in autumn and winter in four types of dairy cattle barns with different process and technical systems (free-stall, deep litter – FS-DL; free-stall, sub-floor manure storage – FS-SFM; free-stall, litter in stalls – FS-LS; tie-stall, litter in stalls – TS-LS) in northern Poland. Analyses of gaseous mixtures in barn air were conducted by infrared spectrometry with the multi-component Gasmet DX4030 analyzer. A total of 200 measurement spectra were acquired and subjected to qualitative and quantitative analyses with the Calcmet Professional program with a library of reference spectra for 200 chemical compounds. The results of the study indicate that housing systems and the technological solutions applied in barns exert a considerable influence on the production of greenhouse and odorous gases. Free-stall housing with slatted floors and sub-floor manure storage appears to be the optimal solution for reducing the animals’ exposure to the presence of the analyzed chemical compounds in air, improving animal welfare and minimizing GHG emissions to the environment (considering the optimal ventilation rate). It should be noted that the concentrations of other potentially harmful compounds, for which the maximum safe levels have been specified, were also relatively low in the remaining systems, which points to the observance of high sanitary standards and the use of efficient ventilation systems in the evaluated barns

Is there a circumbinary planet around NSVS 14256825?

The cyclic behaviour of (O-C) residuals of eclipse timings in the sdB+M eclipsing binary NSVS 14256825 was previously attributed to one or two Jovian-type circumbinary planets. We report 83 new eclipse timings that not only fill in the gaps in those already published but also extend the time span of the (O-C) diagram by three years. Based on the archival and our new data spanning over more than 17 years we re-examined the up to date system (O-C). The data revealed systematic, quasi-sinusoidal variation deviating from an older linear ephemeris by about 100 s. It also exhibits a maximum in the (O-C) near JD 2,456,400 that was previously unknown. We consider two most credible explanations of the (O-C) variability: the light propagation time due to the presence of an invisible companion in a distant circumbinary orbit, and magnetic cycles reshaping one of the binary components, known as the Applegate or Lanza-Rodono effect. We found that the latter mechanism is unlikely due to the insufficient energy budget of the M-dwarf secondary. In the framework of the third-body hypothesis, we obtained meaningful constraints on the Keplerian parameters of a putative companion and its mass. Our best-fitting model indicates that the observed quasi-periodic (O-C) variability can be explained by the presence of a brown dwarf with the minimal mass of 15 Jupiter masses rather than a planet, orbiting the binary in a moderately elliptical orbit (~ 0.175) with the period of ~ 10 years. Our analysis rules out two planets model proposed earlier.Comment: 17 pages, 9 figures, 4 tables, accepted to A

Vitamin D supplementation to treat SARS-CoV-2 positive patients. Evidence from meta-analysis

Background: Vitamin D is a likely candidate for treatment as its immune modulating characteristics have effects on coronavirus disease 2019 (COVID-19) patients. It was  sought herein, to summarize the studies published to date regarding the vitamin D supplementation to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive patients. Methods: A systematic review and meta-analysis were performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The primary outcome were 14-day and in-hospital mortality reported as an odds ratio (OR) with the associated 95% confidence interval (CI). Results: Eight articles were included in the review with a combined total of 2,322 individual patients, 786 in the vitamin D supplementation group and 1,536 in the control group. The use of vitamin D compared to the group without vitamin D supplementation was associated with a lower 14-day mortality (18.8% vs. 31.3%, respectively; OR = 0.51; 95% CI: 0.12–2.19; p = 0.36), a lower in-hospital mortality (5.6% vs. 16.1%; OR = 0.56; 95% CI: 0.23–1.37; I2 = 74%; p = 0.20), the rarer intensive care unit admission (6.4% vs. 23.4%; OR = 0.19; 95% CI: 0.06–0.54; I2 = 77%; p = 0.002) as well as rarer mechanical ventilation (6.5% vs. 18.9%; OR = 0.36; 95% CI: 0.16–0.80; I2 = 0.48; p = 0.01). Conclusions: Vitamin D supplementation in SARS-CoV-2 positive patients has the potential to positively impact patients with both mild and severe symptoms. As several high-quality randomized control studies have demonstrated a benefit in hospital mortality, vitamin D should be considered a supplemental therapy of strong interest. Should vitamin D prove to reduce hospitalization rates and symptoms outside of the hospital setting, the cost and benefit to global pandemic mitigation efforts would be substantial

Adhesive protein-mediated crosstalk between <i>Candida albicans</i> and <i>Porphyromonas gingivalis</i> in dual species biofilm protects the anaerobic bacterium in unfavorable oxic environment

Abstract The oral cavity contains different types of microbial species that colonize human host via extensive cell-to-cell interactions and biofilm formation. Candida albicans —a yeast-like fungus that inhabits mucosal surfaces—is also a significant colonizer of subgingival sites in patients with chronic periodontitis. It is notable however that one of the main infectious agents that causes periodontal disease is an anaerobic bacterium— Porphyromonas gingivalis. In our study, we evaluated the different strategies of both pathogens in the mutual colonization of an artificial surface and confirmed that a protective environment existed for P. gingivalis within developed fungal biofilm formed under oxic conditions where fungal cells grow mainly in their filamentous form i.e. hyphae. A direct physical contact between fungi and P. gingivalis was initiated via a modulation of gene expression for the major fungal cell surface adhesin Als3 and the aspartic proteases Sap6 and Sap9. Proteomic identification of the fungal surfaceome suggested also an involvement of the Mp65 adhesin and a “moonlighting” protein, enolase, as partners for the interaction with P. gingivalis. Using mutant strains of these bacteria that are defective in the production of the gingipains—the proteolytic enzymes that also harbor hemagglutinin domains—significant roles of these proteins in the formation of bacteria-protecting biofilm were clearly demonstrated

Sleep duration and the risk of obesity – a cross-sectional study

Introduction: So far, the association between a longer sleep duration, state of health, and the risk of obesity and the influence of gender on the association between sleep duration and the risk of obesity has not been fully explained. Aim of the research: To examine the relationships between self-reported sleep duration, body mass index (BMI), and body fat percentage (%BF), and also to determine whether such associations are the same in men and in women. Material and methods : This study included 10,367 participants aged 37 to 66 years. Logistic regression was applied for risk assessment of the prevalence of abnormal BMI values and %BF in groups of sleep duration. Sleep of 7–8 h per night was adopted as a reference level. Results: In men, the risk of obesity was significantly greater only in the group sleeping ≤ 6 h (OR = 1.18, 95% CI: 1.08–1.28; p < 0.05); however, in women, only among those sleeping ≥ 9 h (OR = 1.14, 95% CI: 1.02–1.26; p < 0.05). The risk of obesity, determined on the basis of %BF, was higher only in individuals sleeping ≥ 9 h. In the adjusted model, it turned out to be significant in the general study population (OR = 1.28, 95% CI: 1.07–1.53; p < 0.05) and in women (OR = 1.14, 95% CI: 1.03–1.27; p < 0.05). Conclusions: In women, a greater risk of obesity was related to a longer sleep duration (≥ 9 h), whereas in men, the tendency of obesity occurrence along with shorter sleep (≤ 6 h). Thus, the physiological consequences of sleep duration may be different in women than in men

The Effect of Dairy Cattle Housing Systems on the Concentrations and Emissions of Gaseous Mixtures in Barns Determined by Fourier-Transform Infrared Spectroscopy

The aim of this study was to determine the concentrations and emissions of greenhouse and odorous gases in different types of dairy cattle housing systems with the use of Fourier-transform infrared (FTIR) spectroscopy. The study was performed in autumn and winter in four types of dairy cattle barns with different process and technical systems (free-stall, deep litter – FS-DL; free-stall, sub-floor manure storage – FS-SFM; free-stall, litter in stalls – FS-LS; tie-stall, litter in stalls – TS-LS) in northern Poland. Analyses of gaseous mixtures in barn air were conducted by infrared spectrometry with the multi-component Gasmet DX4030 analyzer. A total of 200 measurement spectra were acquired and subjected to qualitative and quantitative analyses with the Calcmet Professional program with a library of reference spectra for 200 chemical compounds. The results of the study indicate that housing systems and the technological solutions applied in barns exert a considerable influence on the production of greenhouse and odorous gases. Free-stall housing with slatted floors and sub-floor manure storage appears to be the optimal solution for reducing the animals’ exposure to the presence of the analyzed chemical compounds in air, improving animal welfare and minimizing GHG emissions to the environment (considering the optimal ventilation rate). It should be noted that the concentrations of other potentially harmful compounds, for which the maximum safe levels have been specified, were also relatively low in the remaining systems, which points to the observance of high sanitary standards and the use of efficient ventilation systems in the evaluated barns.This article is published as Witkowska D., Korczyński M., Koziel J.A., Sowińska J., Chojnowski B. "The Effect of Dairy Cattle Housing Systems on the Concentrations and Emissions of Gaseous Mixtures in Barns Determined by Fourier-Transform Infrared Spectroscopy." Annals of Animal Science 20, no. 4 (2020): 1487–1507. DOI: 10.2478/aoas-2020-0039. Posted with permission.</p