Cosmological Tests for a Linear Coasting Cosmology

A strictly linear evolution of the scale factor is a characteristic feature in several classes of alternative gravity theories, as also in the standard (big-bang) model with specially chosen matter equation of state. In this article we report that this model is consistent with gravitational lensing statistics (within $1\sigma$) and accomodates old high-redshift galaxies. We finally conclude that linear coasting cosmology, \a(t) = t, is not ruled out basis of these observational tests

Degeneracy in exotic gravitational lensing

We present three different theoretically foreseen, but unusual, astrophysical situations where the gravitational lens equation ends up being the same, thus producing a degeneracy problem. These situations are (a) the case of gravitational lensing by exotic stresses (matter violating the weak energy condition and thus having a negative mass, particular cases of wormholes solutions can be used as an example), (b) scalar field gravitational lensing (i.e. when considering the appearance of a scalar charge in the lensing scenario), and (c) gravitational lensing in closed universes (with antipodes).The reasons that lead to this degeneracy in the lens equations, the possibility of actually encountering it in the real universe, and eventually the ways to break it, are discussed.Comment: Accepted for publication in Modern Physics Letters

Hard x-ray photon-in-photon-out spectroscopy with lifetime resolution – of XAS, XES, RIXSS and HERFD

Spectroscopic techniques that aim to resolve the electronic configuration and local coordination of a central atom by detecting inner-shell radiative decays following photoexcitation using hard X-rays are presented. The experimental setup requires an X-ray spectrometer based on perfect crystal Bragg optics. The possibilities arising from non-resonant (X-Ray Emission Spectroscopy - XES) and resonant excitation (Resonant Inelastic X-Ray Scattering Spectroscopy – RIXSS, High-Energy-Resolution Fluorescence Detected (HERFD) XAS) are discussed when the instrumental energy broadenings of the primary (beamline) monochromator and the crystal spectrometer for x-ray emission detection are on the order of the core hole lifetimes of the intermediate and final electronic states. The small energy bandwidth in the emission detection yields line-sharpened absorption features. In transition metal compounds, electron-electron interactions as well as orbital splittings and fractional population can be revealed. Combination with EXAFS spectroscopy enables to extent the k-range beyond unwanted absorption edges in the sample that limit the EXAFS range in conventional absorption spectroscopy

Motion of a Vector Particle in a Curved Spacetime. II First Order Correction to a Geodesic in a Schwarzschild Background

The influence of spin on a photon's motion in a Schwarzschild and FRW spacetimes is studied. The first order correction to the geodesic motion is found. It is shown that unlike the world-lines of spinless particles, the photons world-lines do not lie in a plane.Comment: 14 pages, LaTeX2e, second paper in the series (the first one: gr-qc/0110067), replaced with typos and style corrected version, accepted in MPL

Ultrasound investigation in pregnant women with diabetes mellitus

Introduction. Ultrasound (US) has been used in obstetrics for more than 30 years and is considered to be reliable, simple, quick in results, painless and cheap method. The aim: to optimize the use of US in childbirth in pregnant women with diabetes and determine the outcome of childbirth, taking into account the condition of the fetus and newborn. Materials and methods. 52 pregnant women, among them 32 with diabetes mellitus (pre-gestational diabetes was in 20 persons and 12 persons had gestational diabetes) have been examined.  The average age of pregnant women in the main group was 29.8 ± 5.4 years, in the control group - 25.7 ± 4.3 years. All women in the main and control groups were primiparous. The gestation period in the main group was 39.1 ± 0.5 weeks [38.0; 39.6], in the control group - 39.5 ± 0.7 [38.4; 40.5] weeks. Clinical-laboratory and instrumental examinations were made. Control group consisted of  20 physiologically pregnant women. To determine the condition and size of the fetus and its progress in labor, immediately at the end of the first and during the second staage of labor, transabdominal and transperineal US and Doppler examination were performed with device HD 11 XE Phillips (USA). Results. Pregnant women with diabetes are more likely to have a pathological second stage of labors due to macrosomia and problems with the birth of the fetus, as evidenced by the lack of increased angle of progress and decreased head-perineal distance. The data obtained indicate the prospects of using ultrasound in childbirth as an objective non-invasive method for predicting the likelihood of vaginal birth, which will reduce operative delivery and perinatal pathology. Conclusions. The use of ultrasound in childbirth in women with diabetes and diabetic fetopathy can determine the possibility of complications in the promotion of the fetus, including clinical narrow pelvis, shoulder dystocia, the occurrence of distress, as evidenced by the Apgar scale and CLS. Intraparietal ultrasound helps to guide the plan of childbirth, reduce the frequency of cesarean delivery, perinatal morbidity and mortality, and birth trauma

Adakite-like granitoids of Songkultau: A relic of juvenile Cambrian arc in Kyrgyz Tien Shan

The early Paleozoic Terskey Suture zone, located in the southern part of the Northern Tien Shan domain in Kyrgyzstan, comprises tectonic slivers of dismembered ophiolites and associated primitive volcanics and deep-marine sediments. In the Lake Songkul area, early-middle Cambrian pillow basalts are crosscut by the Songkultau intrusion of coarse-grained gneissose quartz diorites and tonalites with geochemical characteristics typical for high-SiO2 adakites (SiO2 ​> ​56 ​wt.%, Al2O3 ​> ​15 ​wt.%, Na2O ​> ​3.5 ​wt.% and high Sr/Y and La/Yb ratios). The Songkultau granitoids have positive initial εNd (+3.8 to +6.4) and εHf (+12.3 to +13.5) values indicating derivation from sources with MORB-like isotopic signature. Volcanic formations, surrounding the Songkultau intrusion, have geochemical affinities varying from ocean floor to island arc series. This rock assemblage is interpreted as a relic of an early-middle Cambrian primitive arc where the adakite-like granitoids were derived from partial melting of young and hot subducted oceanic crust. An age of 505 ​Ma, obtained for the Songkultau intrusion, shows that hot subduction under the Northern Tien Shan continued until middle Cambrian. The primitive arc complexes were obducted onto the Northern Tien Shan domain, where the Andean type continental magmatic arc developed in Cambrian and Ordovician. Formation of the Andean type arc was accompanied by uplift, erosion and deposition of coarse clastic sediments. A depositional age of ca. 470 Ma, obtained for the gravellites in the Lake Songkul area, is in agreement with the timing of deposition for lower Ordovician conglomerates elsewhere in the Northern Tien Shan, and corresponds to the main phase of the Andean type magmatism. The Songkultau adakites in association with surrounding ocean floor and island arc formations constitute a relic of a primitive Cambrian arc and represent a juvenile domain of substantial size identified so far within the predominantly crustal-derived terranes of Tien Shan. On a regional scale this primitive arc can be compared with juvenile Cambrian arcs of Kazakhstan, Gorny Altai and Mongolia.©2020 China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Microlensing by natural wormholes: theory and simulations

We provide an in depth study of the theoretical peculiarities that arise in effective negative mass lensing, both for the case of a point mass lens and source, and for extended source situations. We describe novel observational signatures arising in the case of a source lensed by a negative mass. We show that a negative mass lens produces total or partial eclipse of the source in the umbra region and also show that the usual Shapiro time delay is replaced with an equivalent time gain. We describe these features both theoretically, as well as through numerical simulations. We provide negative mass microlensing simulations for various intensity profiles and discuss the differences between them. The light curves for microlensing events are presented and contrasted with those due to lensing produced by normal matter. Presence or absence of these features in the observed microlensing events can shed light on the existence of natural wormholes in the Universe.Comment: 16 pages, 24 postscript figures (3 coloured), revtex style, submitted to Phys. Rev.

THE EFFECT OF “FAN” LIMB LENGTHENING TECHNIQUE ON MORPHOFUNCTIONAL STATE OF THE FIRST SENSITIVE NEURONS OF THE MOTOR ANALYZER (EXPERIMENTAL MORPHOLOGICAL STUDY)

The experiment was performed on 10 adult dogs underwent tibial lengthening by 14—18 % from the initial length using a "fan" technique interchanging weekly active periods of dosed lengthening on various muscle groups and. their weekly rest. This effect created sufficiently favourable conditions for bone distraction regenerate formation and functioning of the first sensitive neurons of the motor analyzer