Some data on the biology of stone cockscomb Alectrias alectrolophus (Stichaeidae) from the Tauysk Bay of the Sea of Okhotsk

On the basis of the materials collected in the period of 2010–2018 the features of biology: the size-age structure, linear growth pattern and body mass growth of the stone cockscomb Alectrias alectrolophus from the Tauysk Bay, the Sea of Okhotsk, have been studied. In the intertidal zone, in the period from May to September, individuals of this species the body length 31.2–133.4 mm and body weight 0.1–12.8 g at the age of up to 6+ years are found in large quantities. The size and age characteristics, rates of growth of females and males are quite similar, but in general, females are slightly larger than males.

Subcutanaeous emphysema: An extremely rare manifestation of supraglottic squamous cell carcinoma

We present the case report of a 60 years old man who presented to the emergency department with complaints of breathlessness for 2 weeks. After all common causes were ruled out, the patient was subjected to CT scan of neck in which he showed laryngeal mass growth which was perforating through the cartilage. There were a few surrounding lymph nodes and after an FNAC, it was found to be squamous cell carcinoma. The patient was referred for chemotherapy and radiotherapy at higher centre. To our knowledge, this is a very rare presentation of local extension of tumour. The patient presenting with carcinoma at a very late stage, succumbed to it 2 months later.

Cosmological black holes are not described by the Thakurta metric: LIGO-Virgo bounds on PBHs remain unchanged

We show that the physical conditions which induce the Thakurta metric, recently studied by Bœhm et al. in the context of time-dependent black hole masses, correspond to a single accreting compact object in the entire Universe filled with isotropic non-interacting dust. In such a case, accretion physics is not local but tied to the properties of the whole Universe. We show that radiation, primordial black holes or particle dark matter cannot produce the specific energy flux required for supporting the mass growth of the compact objects described by the Thakurta metric. In particular, this solution does not apply to black hole binaries. We conclude that compact dark matter candidates and their mass growth cannot be described by the Thakurta metric, and thus existing constraints on the primordial black hole abundance from the LIGO-Virgo and the CMB measurements remain valid.

Optical Spectroscopy of Dual Quasar Candidates from the Subaru HSC-SSP program

We report on a spectroscopic program to search for dual quasars using Subaru Hyper Suprime-Cam (HSC) images of SDSS quasars, which represent an important stage during galaxy mergers. Using Subaru/FOCAS and Gemini-N/GMOS, we identify three new physically associated quasar pairs having projected separations less than 20 kpc, out of 26 observed candidates. These include the discovery of the highest-redshift (z = 3.1) quasar pair with a separation <10 kpc. Based on the sample acquired to date, the success rate of identifying physically associated dual quasars is 19% when excluding stars based on their HSC colors. Using the full sample of six spectroscopically confirmed dual quasars, including three previously published, we find that the black holes in these systems have black hole masses (M BH ∼ 108−9 M ⊙), bolometric luminosities (log L bol ∼ 44.5–47.5 erg s–1) and Eddington ratios (0.01–0.3) similar to single SDSS quasars. We measure the stellar mass of their host galaxies based on 2D image decomposition of the five-band (grizy) optical emission and assess the mass relation between supermassive black holes (SMBHs) and their hosts. Dual SMBHs appear to have elevated masses relative to their host galaxies. Thus, mergers may not necessarily align such systems onto the local mass relation, as suggested by the Horizon-AGN simulation. This study suggests that dual luminous quasars are triggered by mergers prior to the final coalescence of the two SMBHs, resulting in early mass growth of the black holes relative to their host galaxies.

Unfounded claims about productivity beyond density for reindeer pastoralism systems

We point out problems with the article Productivity beyond density: A critique of management models for reindeer pastoralism in Norway by Marin and co-workers published in Pastoralism in 2020. In our opinion, there are several misleading claims about the governance of the reindeer pastoralist system in Norway, the Røros model for herd management and density dependence in reindeer herds in their article. We point out the errors in their empirical re-evaluation of previous work on the relationship between reindeer densities and the productivity and slaughter weights in herds. These errors have a significant bearing on their conclusions. We agree that weather variability has a substantial impact on reindeer body mass growth, fecundity and survival, but disagree with Marin et al. when they argue that reindeer densities are of minor importance for reindeer productivity and animal welfare.

Morphometric parameters and indices of the lumbar intervertebral disks at girls and women

Annotation. Individual variability of intervertebral discs is one of the factors that makes it difficult to recognize the early signs of their pathological changes before the onset of clinical manifestations. In the development of evidence-based medicine, it is important to use clear criteria for distinguishing between norm and pathology, taking into account individual variability. The “mathematical modeling” and a comprehensive approach to quantitative and qualitative assessment of intervertebral discs will help in the early detection of abnormalities, in the individualization of norm, as well as in modeling the parameters of the artificial intervertebral disc for reconstructive interventions. The analysis by methods of descriptive statistics and the correlation analysis for the purpose of further mathematical processing, selection of optimal parameters for mathematical modeling is carried out. Anthropometric characteristics (body length and body weight, mass-growth factor and mass-growth index) were determined in young women and women of the first period of adulthood (16-26 years), as in separate age groups and in the combined group. MRI of the lumbar spine was performed, followed by morphometry. Statistical analysis was performed in the license program “STATISTICA 6.1”. The mean values of the variation series, standard deviations, coefficients of variation and asymmetry, paired t-test, d-test of Kolmogorov-Smirnov type, Levene index were evaluated. It was determined that the sums of the transverse and sagittal dimensions and the sums of the three dimensions increase proportionally in the caudal direction, have a distribution of indicators as close as possible to normal, and their coefficients of variation are many times smaller than for cross-sectional areas and volumes. Indicators of the ratio of the sum of sagittal and transverse size and the sum of three sizes to the average height of the intervertebral discs have a variability of less than 10% and correspond to the characteristics of the general population. Body weight and body length have significantly higher correlation coefficients with the sums of sagittal and transverse dimensions, with the sums of three dimensions, and cross-sectional areas in comparison with the partial dimensions of the intervertebral discs.

Rapid mass growth and enhanced light extinction of atmospheric aerosols during the heating season haze episodes in Beijing revealed by aerosol–chemistry–radiation–boundary layer interaction

Despite the numerous studies investigating haze formation mechanism in China, it is still puzzling that intensive haze episodes could form within hours directly following relatively clean periods. Haze has been suggested to be initiated by the variation of meteorological parameters and then to be substantially enhanced by aerosol–radiation–boundary layer feedback. However, knowledge on the detailed chemical processes and the driving factors for extensive aerosol mass accumulation during the feedback is still scarce. Here, the dependency of the aerosol number size distribution, mass concentration and chemical composition on the daytime mixing layer height (MLH) in urban Beijing is investigated. The size distribution and chemical composition-resolved dry aerosol light extinction is also explored. The results indicate that the aerosol mass concentration and fraction of nitrate increased dramatically when the MLH decreased from high to low conditions, corresponding to relatively clean and polluted conditions, respectively. Particles having their dry diameters in the size of ∼400–700 nm, and especially particle-phase ammonium nitrate and liquid water, contributed greatly to visibility degradation during the winter haze periods. The dependency of aerosol composition on the MLH revealed that ammonium nitrate and aerosol water content increased the most during low MLH conditions, which may have further triggered enhanced formation of sulfate and organic aerosol via heterogeneous reactions. As a result, more sulfate, nitrate and water-soluble organics were formed, leading to an enhanced water uptake ability and increased light extinction by the aerosols. The results of this study contribute towards a more detailed understanding of the aerosol–chemistry–radiation–boundary layer feedback that is likely to be responsible for explosive aerosol mass growth events in urban Beijing.

Hygroscopic properties of particulate matter and effects of their interactions with weather on visibility

The hygroscopic property of particulate matter (PM) influencing light scattering and absorption is vital for determining visibility and accurate sensing of PM using a low-cost sensor. In this study, we examined the hygroscopic properties of coarse PM (CPM) and fine PM (FPM; PM2.5) and the effects of their interactions with weather factors on visibility. A censored regression model was built to investigate the relationships between CPM and PM2.5 concentrations and weather observations. Based on the observed and modeled visibility, we computed the optical hygroscopic growth factor, $$f\left( {RH} \right)$$ f RH , and the hygroscopic mass growth, $$GM_{VIS}$$ G M VIS , which were applied to PM2.5 field measurement using a low-cost PM sensor in two different regions. The results revealed that the CPM and PM2.5 concentrations negatively affect visibility according to the weather type, with substantial modulation of the interaction between the relative humidity (RH) and PM2.5. The modeled $$f\left( {RH} \right)$$ f RH agreed well with the observed $$f\left( {RH} \right)$$ f RH in the RH range of the haze and mist. Finally, the RH-adjusted PM2.5 concentrations based on the visibility-derived hygroscopic mass growth showed the accuracy of the low-cost PM sensor improved. These findings demonstrate that in addition to visibility prediction, relationships between PMs and meteorological variables influence light scattering PM sensing.