Direct cell mass measurements expand the role of small microorganisms in nature.

Microbial biomass is a key parameter needed for the quantification of microbial turnover rates and their contribution to the biogeochemical element cycles. However, estimates of microbial biomass rely on empirically-derived mass-to-volume relationships and large discrepancies exist between the available empirical conversion factors. Here we report a significant non-linear relationship between carbon mass and cell volume (mcarbon = 197 × V0.46.; R2 = 0.95) based on direct cell mass, volume and elemental composition measurements of twelve prokaryotic species with average volumes between 0.011 – 0.705 μm3. The carbon mass density of our measured cells ranged from 250 to 1800 fg C μm-3 for the measured cell volumes. Compared to other currently used models, our relationship yielded up to 300 % higher carbon mass values. A compilation of our and previously published data showed that cells with larger volumes (> 0.5 μm3) display a constant (carbon) mass-to-volume ratio whereas cells with volumes below 0.5 μm3 exhibit a nonlinear increase in (carbon) mass density with decreasing volume. Small microorganisms dominate marine and freshwater bacterioplankton as well as soils and marine and terrestrial subsurface. The application of our experimentally-determined conversion factors will help to quantify the true contribution of these microorganisms to ecosystem functions and global microbial biomass

VOLUNTEERING IN RUSSIAN REGIONS: SOCIO-PSYCHOLOGICAL FEATURES, PROBLEMS OF REALIZATION AND ITS SOLUTION

Volunteering, as a relatively new form of manifesting social activity, but in demand in society, requires a comprehensive study. The main purpose of this research is assessment of socio-psychological features of volunteer activities and the problems of its implementation in the regions of Russia, including in conditions of increased social tension caused by the coronavirus pandemic. The article presents the results of the interregional sociological Internet survey of volunteers conducted by the authors (on the example of the regions of the Central Federal District of the Russian Federation). Their analysis made it possible to obtain new evaluation and analytical information about the phenomenon being studied, to expand ideas about modern trends in the development of volunteering, including in the current situation of social tension; determine the vector of solving the existing problems in this area. Based on the results of the study, the authors propose practical recommendations to increase the effectiveness of volunteer activities in the regions, which can be integrated into the processes of making political and organizational and methodological decisions

Тяжесть поражения коронарных артерий у больных ишемической болезнью сердца с различными вариантами гена рецептора витамина D и уровнем обеспеченности витамином D

Introduction. Vitamin D deficiency may be an independent predictor of coronary heart disease (CHD) and the severity of coronary atherosclerosis. The results of studies of the association of various polymorphisms of the vitamin D receptor (VDR) gene with the risk and severity of CHD are contradictory, which necessitates the study of genetic variants of the VDR gene and the characteristics of the clinical course of CHD in the Russian population.The objective was to determine the distribution of genotypes of TaqI, BsmI and ApaI of polymorphic variants of the VDR gene and the level of vitamin D sufficiency in CHD patients with varying severity of CHD, residents of St. Petersburg.Methods and materials. The study included 407 CHD patients and 318 patients without clinical signs of CHD of comparable age (p>0.05). All CHD patients underwent coronary angiography. Typing of the VDR gene variants was performed by polymerase chain reaction and subsequent restriction analysis. Determination of the level of 25(OH)D blood serum was carried out by enzyme immunoassay.Results. Vitamin D deficiency was detected in 82 % of CHD patients, the content of 25(OH)D in blood serum was lower in CHD patients who had 2 or more myocardial infarctions (MI) than in those who had one MI (p=0.03). Vitamin D deficiency is associated with a 3.6-fold increased risk of multivessel disease (p=0.01). The presence of the aa genotype and the a allele (ApaI), the bb genotype and the b allele of the VDR gene (BsmI) is associated with an increased risk of CHD and the severity of atherosclerotic lesions of the coronary arteries.Conclusion. Vitamin D deficiency is typical for CHD patients and is associated with the severity of coronary atherosclerosis. The presence of aa genotype and a allele (ApaI polymorphism), bb genotype and b allele of the VDR gene (BsmI polymorphism) is associated with an increased risk of CHD and the severity of atherosclerotic lesions of the coronary arteries. TaqI polymorphism of the VDR gene is not associated with the risk of CHD.Актуальность. Дефицит витамина D может быть независимым предиктором ишемической болезни сердца (ИБС) и тяжести коронарного атеросклероза. Результаты исследований связи различных полиморфизмов гена рецептора витамина D (VDR) с риском и тяжестью ИБС противоречивы, что обуславливает необходимость изучения генетических вариантов гена VDR и особенностей клинического течения ИБС в российской популяции.Введение. Дефицит витамина D может быть независимым предиктором ишемической болезни сердца (ИБС) и тяжести коронарного атеросклероза. Результаты исследований связи различных полиморфизмов гена рецептора витамина D (VDR) с риском и тяжестью ИБС противоречивы, что обуславливает необходимость изучения генетических вариантов гена VDR и особенностей клинического течения ИБС в российской популяции.Цель – определить распределения генотипов TaqI, BsmI и ApaI полиморфных вариантов гена рецептора витамина D и уровня обеспеченности витамином D у больных ИБС с различной тяжестью поражения коронарных артерий, жителей Санкт-Петербурга.Методы и материалы. В исследование включены 407 больных ИБС и 318 обследованных без клинических признаков ИБС, сопоставимого возраста (р>0,05). Всем больным ИБС была выполнена коронарография. Типирование вариантов гена VDR проводили методом полимеразной цепной реакции и последующего рестрикционного анализа. Определение уровня 25(OH)D сыворотки крови проводили иммуноферментным методом.Результаты. У 82 % больных ИБС выявлен дефицит витамина D, содержание 25(ОН)D сыворотки крови было ниже у больных ИБС, перенесших два и более инфаркта миокарда (ИМ), чем у перенесших один ИМ (р=0,03). Дефицит витамина D ассоциируется с повышением риска многососудистого поражения в 3,6 раза (р=0,01). Наличие aa­генотипа и а-аллеля (АраI), bb-генотипa и b-аллеля гена VDR (BsmI) ассоциируется с повышением риска ИБС и с тяжестью атеросклеротического поражения коронарных артерий.Заключение. Дефицит витамина D характерен для больных ИБС и ассоциируется с тяжестью коронарного атеросклероза. Наличие aa-генотипа и а-аллеля (АраI-полиморфизм), bb-генотипa и b-аллеля гена VDR (BsmI-полиморфизм) ассоциируется с повышением риска ИБС и с тяжестью атеросклеротического поражения коронарных артерий. TaqI-полиморфизм гена VDR не ассоциирован с риском ИБС

SEIS: Insight’s Seismic Experiment for Internal Structure of Mars

By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars’ surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking’s Mars seismic monitoring by a factor of ∼ 2500 at 1 Hz and ∼ 200 000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars’ surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of Mw ∼ 3 at 40◦ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution

Carbon recycling efficiency and phosphate turnover by marine nitrifying archaea

Thaumarchaeotal nitrifiers are among the most abundant organisms in the ocean, but still unknown is the carbon (C) yield from nitrification and the coupling of these fluxes to phosphorus (P) turnover and release of metabolites from the cell. Using a dual radiotracer approach, we found that Nitrosopumilus maritimus fixed roughly 0.3 mol C, assimilated 2 mmol P, and released ca. 10(-2) mol C and 10(-5) mol P as dissolved organics (DOC and DOP) per mole ammonia respired. Phosphate turnover may influence assimilation fluxes by nitrifiers in the euphotic zone, which parallel those of the dark ocean. Collectively, marine nitrifiers assimilate up to 2 Pg C year(-1) and 0.05 Pg P year(-1) and thereby recycle roughly 5% of mineralized C and P into marine biomass. Release of roughly 50 Tg DOC and 0.2 Tg DOP by thaumarchaea each year represents a small but fresh input of reduced substrates throughout the ocean

Spectrotemporal similarity and self-imaging of nonlinear dispersive similarition

International audienceUsing spectral-interferometry for short pulse complete characterization, we studied the similariton generated in single-mode fiber without gain due to the combined impacts of nonlinearity and dispersion. The nonlinear-spectronic nature of such a similariton, with the key specificity of linear chirping, leads to its self-spectrotemporal imaging, important for applications to signal analysis - synthesis problems in ultrafast optics

GPS-Aided Real-Time Earthquake and Tsunami (GREAT) Alert System

No abstract availabl