Self-gravitating astrophysical mass with singular central density vibrating in fundamental mode

The fluid-dynamical model of a self-gravitating mass of viscous liquid with singular density at the center vibrating in fundamental mode is considered in juxtaposition with that for Kelvin fundamental mode in a homogeneous heavy mass of incompressible inviscid liquid. Particular attention is given to the difference between spectral formulae for the frequency and lifetime of $f$-mode in the singular and homogeneous models. The newly obtained results are discussed in the context of theoretical asteroseismology of pre-white dwarf stage of red giants and stellar cocoons -- spherical gas-dust clouds with dense star-forming core at the center.Comment: Mod. Phys. Lett. A, Vol. 24, No. 40 (2009) pp. 3257-327

Особенности организации помощи и диспансерное наблюдение взрослых, больных муковисцидозом

Based on the long-term surveillance of 127 patients older than 15 yrs and 173 children aged 3 months to 15 yrs we concluded of the survival age of cystic fibrosis patients in Russia (16.9 ±1.1 yrs). Patients older than 15 yrs take 30.1 % of all the investigated patients. Under the adequate surveillance and treatment conditions 82.4 % of adult patients keep their social activity and only 17.6 % of the patients do not work and do not study.На основании многолетнего наблюдения за 127 пациентами старше 15 лет и 173 детьми в возрасте от 3 мес. до 15 лет делаются выводы о возрасте выживаемости больных муковисцидозом в России (16,9 ± 1,1 год), лица старше 15 лет среди всех обследованных составляют 30,1 % . При правильно организованном диспансерном наблюдении и лечении 82,4 % взрослых сохраняют социальную активность и только 17,6 % не работают и не учатся

Frequency spectrum of toroidal Alfv\'en mode in a neutron star with Ferraro's form of nonhomogeneous poloidal magnetic field

Using the energy variational method of magneto-solid-mechanical theory of a perfectly conducting elastic medium threaded by magnetic field, the frequency spectrum of Lorentz-force-driven global torsional nodeless vibrations of a neutron star with Ferraro's form of axisymmetric poloidal nonhomogeneous internal and dipole-like external magnetic field is obtained and compared with that for this toroidal Alfv\'en mode in a neutron star with homogeneous internal and dipolar external magnetic field. The relevance of considered asteroseismic models to quasi-periodic oscillations of the X-ray flux during the ultra powerful outbursts of SGR 1806-20 and SGR 1900+14 is discussed.Comment: Accepted for publication in Astrophysics & Space Scienc

Research is needed to inform environmental management of hydrothermally inactive and extinct polymetallic sulfide (PMS) deposits

Polymetallic sulfide (PMS) deposits produced at hydrothermal vents in the deep sea are of potential interest to miners. Hydrothermally active sulfide ecosystems are valued for the extraordinary chemosynthetic communities that they support. Many countries, including Canada, Portugal, and the United States, protect vent ecosystems in their Exclusive Economic Zones. When hydrothermal activity ceases temporarily (dormancy) or permanently (extinction), the habitat and associated ecosystem change dramatically. Until recently, so-called "inactive sulfide" habitats, either dormant or extinct, received little attention from biologists. However, the need for environmental management of deep-sea mining places new imperatives for building scientific understanding of the structure and function of inactive PMS deposits. This paper calls for actions of the scientific community and the emergent seabed mining industry to i) undertake fundamental ecological descriptions and study of ecosystem functions and services associated with hydrothermally inactive PMS deposits, ii) evaluate potential environmental risks to ecosystems of inactive PMS deposits through research, and iii) identify environmental management needs that may enable mining of inactive PMS deposits. Mining of some extinct PMS deposits may have reduced environmental risk compared to other seabed mining activities, but this must be validated through scientific research on a case-by-case basis.FCT: IF/00029/2014/CP1230/CT0002/ UID/05634/2020/ CEECIND005262017/ UID/MAR/00350/2019; Direcao-Geral de Politica do Mar (DGPM) Mining2/2017/005/ Mining2/2017/001info:eu-repo/semantics/publishedVersio

The Magnitude of Global Marine Species Diversity

Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. Results: There are ∼226,000 eukaryotic marine species described. More species were described in the past decade (∼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∼170,000 synonyms, that 58,000–72,000 species are collected but not yet described, and that 482,000–741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7–1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century

The Salas y Gomez and Nazca ridges: A review of the importance, opportunities and challenges for protecting a global diversity hotspot on the high seas

http://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr18-06_leg3/