Downstream and soaring interfaces and vortices in 2-D stratified wakes and their impact on transport of contaminants

The flow of continuously stratified fluids past obstacles was studied analytically, numerically, and experimentally. The obstacles discussed here include a flat strip, aligned with the flow, inclined or transverse to the flow and a horizontal cylinder. In the flow pattern, transient and attached (lee) internal waves, downstream wakes with submerged interfaces and vortices, soaring singular interfaces, soaring vortices and vortex systems are distinguished. New components of laminar flow past a horizontally towed strip are presented. Fine transverse streaky structures on the strip in the downstream wake were visualized. Soaring isolated interfaces, which are internal boundary layers forming inside the downstream attached wave field past bluff bodies were observed. With increasing of the body velocity a vortex pair was formed directly at the leading edge of this interface

Geostrophic adjustement of density fronts: what do we learn from recent laboratory experiments ?

We present here a rapid review on recent laboratory investigations on geostrophic adjustment of density fronts. Several configurations were studied: warm core lens, cyclonic-anticyclonic PV patches and uniform PV front. The geostrophic adjustment is the first dynamical process which converts a significant fraction of the potential energy input of the atmosphere and the ocean into kinetic energy. According to the cases we studied we have shown that during this rapid adjustment toward a quasi-equilibrium state, an important part of the initial energy could be transferred to wave motion or dissipated by small-scale non-hydrostatic instabilities. A mean adjusted state is always reached after one or two inertial period. Even if a strong wave activity is present in the initial region of unbalance, the time-averaged mean flow could nevertheless be adjusted. We have shown that the wave modes frequency is concentrated around the inertial frequency. Besides, some anticyclonic structures may also exhibit sub-inertial o

Mobile app as a tool to collect health data: a survey on vaccination against COVID-19

Objective. To evaluate the feasibility of using a mobile app to collect health-related data and the impact of this data collection method on the results obtained, using the COVID-19 vaccination attitude assessment as an example. Material and methods. A survey was conducted on attitudes towards COVID-19 vaccination using the «Know Your Heart» mobile app. A total of 1,770 Arkhangelsk region residents aged 35—74 years who participated in the ЭССЕ-РФ3 survey conducted in the Arkhangelsk region in 2021 were invited to install the application and take part in the survey. Multiple logistic regression analysis was used to evaluate factors related to application installation and survey participation. Results. Of the total number of subjects invited to participate in the study, 611 (34.5%) installed the mobile app, and 150 (8.5%) participated in the survey. Subjects under 65 were more likely to install the application than those 65—74, as were subjects with a steady job versus those without one. Subjects under 65 years of age showed a higher responding rate to the invitation to participate in the mobile survey. Individuals who abused alcohol were less likely to agree to participate in the mobile survey. The majority of respondents are vaccinated against COVID-19 (81%). Vaccinated subjects and those confident in the effectiveness of nonspecific preventive measures were more likely to have positive attitudes towards vaccination. Conclusion. The low response rate to the survey resulting in an unrepresentative sample determined the low effectiveness of the survey using the mobile app. When overcoming these obstacles, mobile applications have the potential to be used in scientific research due to their high speed, accessibility, and ease of data collection

Differentially activated B cells develop regulatory phenotype and show varying immunosuppressive features: a comparative study

Regulatory B lymphocytes (Bregs) are B cells with well-pronounced immunosuppressive properties, allowing them to suppress the activity of effector cells. A broad repertoire of immunosuppressive mechanisms makes Bregs an attractive tool for adoptive cell therapy for diseases associated with excessive activation of immune reactions. Such therapy implies Breg extraction from the patient’s peripheral blood, ex vivo activation and expansion, and further infusion into the patient. At the same time, the utility of Bregs for therapeutic approaches is limited by their small numbers and extremely low survival rate, which is typical for all primary B cell cultures. Therefore, extracting CD19+ cells from the patient’s peripheral blood and specifically activating them ex vivo to make B cells acquire a suppressive phenotype seems to be far more productive. It will allow a much larger number of B cells to be obtained initially, which may significantly increase the likelihood of successful immunosuppression after adoptive Breg transfer. This comparative study focuses on finding ways to efficiently manipulate B cells in vitro to differentiate them into Bregs. We used CD40L, CpG, IL4, IL21, PMA, and ionomycin in various combinations to generate immunosuppressive phenotype in B cells and performed functional assays to test their regulatory capacity. This work shows that treatment of primary B cells using CD40L + CpG + IL21 mix was most effective in terms of induction of functionally active regulatory B lymphocytes with high immunosuppressive capacity ex vivo