Potassium Ions are More Effective than Sodium Ions in Salt Induced Peptide Formation

Prebiotic peptide formation under aqueous conditions in the presence of metal ions is one of the plausible triggers of the emergence of life. The salt-induced peptide formation reaction has been suggested as being prebiotically relevant and was examined for the formation of peptides in NaCl solutions. In previous work we have argued that the first protocell could have emerged in KCl solution. Using HPLC-MS/MS analysis, we found that K(+) is more than an order of magnitude more effective in the L-glutamic acid oligomerization with 1,1'-carbonyldiimidazole in aqueous solutions than the same concentration of Na(+), which is consistent with the diffusion theory calculations. We anticipate that prebiotic peptides could have formed with K(+) as the driving force, not Na(+), as commonly believed

Diffractive Structure Function in a Quasi-Classical Approximation

We derive an expression for diffractive F_2 structure function which should be valid at small x for quasi-elastic scattering on a hadron and for quasi-elastic scattering on a large nucleus. This expression includes multiple rescatterings of the quark-antiquark pair produced by the virtual photon off the sources of color charge in a quasi-classical approximation. We find that there is a relation between such diffractive production and inclusive processes. In the former, one averages over all colors of sources before squaring the amplitude, and in the latter one first squares the amplitude and then averages it in the hadron's or nuclear wave function. We show that in the limit of a large virtuality of the photon Q^2 the diffractive structure function becomes linearly proportional to the gluon distribution of the hadron or nucleus, therefore proving that in this sense diffraction is a leading twist effect.Comment: 11 pages, 4 figures, REVTeX, some changes included, a mistake is correcte

Small-x F_2 Structure Function of a Nucleus Including Multiple Pomeron Exchanges

We derive an equation determining the small-x evolution of the F_2 structure function of a large nucleus which includes all multiple pomeron exchanges in the leading logarithmic approximation using Mueller's dipole model. We show that in the double leading logarithmic limit this evolution equation reduces to the GLR equation.Comment: REVTeX, 11 pages, 4 figures, few minor changes include

First Search for Axion-Like Particles in a Storage Ring Using a Polarized Deuteron Beam

Based on the notion that the local dark-matter field of axions or axion-like particles (ALPs) in our Galaxy induces oscillating couplings to the spins of nucleons and nuclei (via the electric dipole moment of the latter and/or the paramagnetic axion-wind effect), we performed the first experiment to search for ALPs using a storage ring. For that purpose, we used an in-plane polarized deuteron beam stored at the Cooler Synchrotron COSY, scanning momenta near 970 MeV/c. This entailed a scan of the spin precession frequency. At resonance between the spin precession frequency of deuterons and the ALP-induced EDM oscillation frequency there will be an accumulation of the polarization component out of the ring plane. Since the axion frequency is unknown, the momentum of the beam and consequently the spin precession frequency were ramped to search for a vertical polarization change that would occur when the resonance is crossed. At COSY, four beam bunches with different polarization directions were used to make sure that no resonance was missed because of the unknown relative phase between the polarization precession and the axion/ALP field. A frequency window of 1.5-kHz width around the spin precession frequency of 121 kHz was scanned. We describe the experimental procedure and a test of the methodology with the help of a radiofrequency Wien filter located on the COSY ring. No ALP resonance was observed. As a consequence an upper limit of the oscillating EDM component of the deuteron as well as its axion coupling constants are provided.Comment: 25 pages, 24 figures, 7 tables, 67 reference

USE OF HIGH SURFACE NANOFIBROUS MATERIALS IN MEDICINE

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Snow Cover and Permafrost Soil Temperature Influence on the Radial Growth of Trees in Central Yakutia

Проведен анализ связи снежного покрова с температурным режимом мерзлотных почв и их влияние на радиальный прирост лиственницы Гмелина и сосны обыкновенной в Центральной Якутии. Высота снежного покрова и период его установления в предыдущем году определяет температурный режим почвогрунтов. Установлено, что при малой высоте снежного покрова происходит сильное промерзание грунтов в зимний период, что отрицательно сказывается на радиальном приросте деревьев в последующий год. Кроме предзимних характеристик снежного покрова на развитие лесной растительности большое влияние оказывают максимальная высота и время схода снежного покрова. Выявлены различия влияния снежного покрова на рост деревьев в различных почвогрунтовых и ландшафтно-географических условиях произрастания.Analysis of snow cover and permafrost soil temperature regime and their influence on the radial growth of trees in Central Yakutia were carried out. Snow depth and the period of its establishment in the previous year determines the intensity and rate of soil freezing and , as a result, the temperature regime of soil. It was founded that shallow snow depth leads to strong freezing of soils during winter, which affects the radial increment of trees in the subsequent year. Except of pre-winter snow cover characteristics, the maximum height and time of snow cover melting strongly affect the forest vegetation development of the study area. This study revealed differences in snow cover influence on the tree growth among different soils and landscape-geographical conditions

Snow Cover and Permafrost Soil Temperature Influence on the Radial Growth of Trees in Central Yakutia

Проведен анализ связи снежного покрова с температурным режимом мерзлотных почв и их влияние на радиальный прирост лиственницы Гмелина и сосны обыкновенной в Центральной Якутии. Высота снежного покрова и период его установления в предыдущем году определяет температурный режим почвогрунтов. Установлено, что при малой высоте снежного покрова происходит сильное промерзание грунтов в зимний период, что отрицательно сказывается на радиальном приросте деревьев в последующий год. Кроме предзимних характеристик снежного покрова на развитие лесной растительности большое влияние оказывают максимальная высота и время схода снежного покрова. Выявлены различия влияния снежного покрова на рост деревьев в различных почвогрунтовых и ландшафтно-географических условиях произрастания.Analysis of snow cover and permafrost soil temperature regime and their influence on the radial growth of trees in Central Yakutia were carried out. Snow depth and the period of its establishment in the previous year determines the intensity and rate of soil freezing and , as a result, the temperature regime of soil. It was founded that shallow snow depth leads to strong freezing of soils during winter, which affects the radial increment of trees in the subsequent year. Except of pre-winter snow cover characteristics, the maximum height and time of snow cover melting strongly affect the forest vegetation development of the study area. This study revealed differences in snow cover influence on the tree growth among different soils and landscape-geographical conditions

General relativity effects in precision spin experimental tests of fundamental symmetries

A search for the $P$- and $CP(T)$-violating electric dipole moments (EDM) of atoms, particles and nuclei with sensitivity up to $10^{-15}$ in units of magnetic dipole moments, allowed by all discrete symmetries, is one of the topical problems of modern physics. According to Sakharov, $CP$-violation is one of the three key criteria of baryogenesis in generally accepted paradigm of the Big Bang cosmology. All three criteria are supported by the Standard Model (SM), but it fails to describe the observed baryon asymmetry of the Universe. This is regarded a strong argument in favor of existence of $CP$-symmetry breaking mechanisms beyond minimal SM, which can lead to measurable EDMs of atoms, particles and nuclei. Direct searches for EDM of charged particles and nuclei are possible only in storage rings (COSY, NICA). After successful studies by the JEDI collaboration at the COSY synchrotron, at the forefront is a search for the proton EDM in an electrostatic storage ring with the proton spin frozen at the magic energy with projected sensitivity $d_p\sim 10^{-29}\,e\cdot$cm. Following a brief introduction to the $CP$-violation physics and the baryogenesis, the review presents a detailed discussion of significant contributions to the spin dynamics from the terrestrial gravity along with the new effects of Earth's rotation in ultrasensitive searches for the EDM of charged particles and neutrons. Quite remarkably, for the projected sensitivity to the proton EDM, these false EDM effects can by one to two orders of magnitude exceed the signal of the proton EDM, and become comparable to an EDM contribution in experiments with ultracold neutrons. We also discuss the role of a precessing spin as a detector of the axion-like dark matter, and consider applications of the quantum gravitational anomalies to the dense matter hydrodynamics and the spin phenomena in the non-central nuclear collisions.Comment: 47 pages, no figures, Revtex, minor editing with misprints removed, accepted for publication in Physics-Uspekh

Re-Os Systematics in the Layered Rocks and Cu-Ni-PGE Sulfide Ores from the Dovyren Intrusive Complex in Southern Siberia, Russia: Implications for the Original Mantle Source and the Effects of Two-Stage Crustal Contamination

The Dovyren Intrusive Complex (Northern Baikal region, 728 ± 3 Ma) includes the dunite–troctolite–gabbronorite Yoko–Dovyren massif (YDM) associated with a sequence of underlying mafic-to-ultramafic sills, locally demonstrating interbedding relations with the most primitive rocks of the pluton. These sills and apophyses contain sulfide mineralization ranging from globular to net-textured and massive ores. Major types of the YDM cumulates and sulfide mineralization were examined for their PGE contents and Re-Os isotopic systematics. The ten analyzed samples included chilled and basal rocks, poorly mineralized troctolite, PGE-rich anorthosite, as well as three samples from a thick ore-bearing apophysis DV10 connected with the YDM. These samples yielded a Re-Os isochron with an age of 759 ± 36 Ma and an initial 187Os/188Os of 0.1309 ± 0.0026 (MSWD = 110), which is in consistent with the previously reported U–Pb zircon age. It is shown that being recalculated to γOs(t) at t = 728 Ma, these isotopic compositions demonstrate three clusters regarding the relationship between γOs(t) and 187Re/188Os: (i) the chilled gabbronorite (YDM) and subcontact olivine gabbronorite (DV10) yielded the most radiogenic values of γOs(t) 10.5 and 10.0 among basal ultramafics, (ii) plagiodunite, troctolite, and sulfide ores showed lower radiogenic compositions, with γOs(t) ranging from 7.3 to 8.7, (iii) olivine gabbronorite, plagioperidotite, and one sample of PGE-rich anorthosite yield very primitive γOs(t) in the range 4.5 to 5.6 (on average 5.2 ± 0.6). The lowest values of γOs(t) for the least fractionated rocks of the YDM suggest a primitive mantle source, formed from a partly contaminated Neoarchean protolith, which is considered to be anomalous in Upper Riphean due to very low εNd(t) of −16 for the most primitive Dovyren magma (Fo88-parent). The highest values of γOs(t) and relative enrichment in the 34S isotope in the chilled gabbronorite (YDM) and subcontact olivine gabbronorite (DV10) evidence that their primitive to evolved magmatic precursors could be affected by a metamorphic fluid enriched in radiogenic 187Os, originating in the exocontact halo due to the thermal decomposition of pyrite from the dehydrated country rocks. This is consistent with the second-stage contamination of the Dovyren magma by the hosting crustal rocks (probably of 10 wt% shists), generating more evolved Fo86-parent magma with higher εNd(t) of −14