154 research outputs found
Quantum field theory and time machines
We analyze the "F-locality condition" (proposed by Kay to be a mathematical
implementation of a philosophical bias related to the equivalence principle, we
call it the "GH-equivalence principle"), which is often used to build a
generalization of quantum field theory to non-globally hyperbolic spacetimes.
In particular we argue that the theorem proved by Kay, Radzikowski, and Wald to
the effect that time machines with compactly generated Cauchy horizons are
incompatible with the F-locality condition actually does not support the
"chronology protection conjecture", but rather testifies that the F-locality
condition must be modified or abandoned. We also show that this condition
imposes a severe restriction on the geometry of the world (it is just this
restriction that comes into conflict with the existence of a time machine),
which does not follow from the above mentioned philosophical bias. So, one need
not sacrifice the GH-equivalence principle to "emend" the F-locality condition.
As an example we consider a particular modification, the "MF-locality
condition". The theory obtained by replacing the F-locality condition with the
MF-locality condition possesses a few attractive features. One of them is that
it is consistent with both locality and the existence of time machines.Comment: Revtex, 14 pages, 1 .ps figure. To appear in Phys. Rev. D More
detailed discussion is given on the MF-locality condition. Minor corrections
in terminolog
Lambda-inflation and CMB anisotropy
We explore a broad class of three-parameter inflationary models, called the
-inflation, and its observational predictions: high abundance of
cosmic gravitational waves consistent with the Harrison-Zel'dovich spectrum of
primordial cosmological perturbations, the non-power-law wing-like spectrum of
matter density perturbations, high efficiency of these models to meet current
observational tests, and others. We show that a parity contribution of the
gravitational waves and adiabatic density perturbations into the large-scale
temperature anisotropy, T/S , is a common feature of
-inflation; the maximum values of T/S (basically not larger than 10)
are reached in models where (i) the local spectrum shape of density
perturbations is flat or slightly red (), and (ii) the residual
potential energy of the inflaton is near the GUT scale (). The conditions to find large T/S in the paradigm of cosmic
inflation and the relationship of T/S to the ratio of the power spectra, ,
and to the inflationary and Hubble parameters, are discussed. We argue
that a simple estimate, T/S, is true for most known inflationary solutions and allows
to relate straightforwardly the important parameters of observational and
physical cosmology.Comment: 29 pages, 3 figures include
Фармакоэпидемиология лекарственных средств, применяемых для лечения инфаркта мозга, в стационарах различного типа
cerebral infarction – is serious medical and social problem. Results of pharmacoepidemiological studies provide an objective assessment of the quality of pharmacotherapy of brain infarction, and find out the rational use of drugs and to identify ways to optimize the consumption of drugs. The results of pharmacoepidemiological analysis of drugs used for the treatment of cerebral infarction in hospitals of various types, are presented. An assessment of compliance with national and international recommendations «is carried out».инфаркт головного мозга – серьезная медицинская и социальная проблема. Результаты фармакоэпидемиологических исследований позволяют объективно оценить качество фармакотерапии инфаркта мозга, выяснить рациональность использования лекарственных средств и наметить пути оптимизации потребления медикаментов. Представлены результаты фармакоэпидемиологического анализа лекарственных средств, применяемых для лечения инфаркта мозга в стационарах различного типа. Проведена оценка их соответствия национальным и международным рекомендациям
On creating mass/matter by extra dimensions in the Einstein-Gauss-Bonnet gravity
Kaluza-Klein (KK) black hole solutions in the Einstein-Gauss-Bonnet (EGB)
gravity in dimensions obtained in the current series of the works by Maeda,
Dadhich and Molina are examined. Interpreting their solutions, the authors
claim that the mass/matter is created by the extra dimensions. To support this
claim, one needs to show that such objects have classically defined masses. We
calculate the mass and mass flux for 3D KK black holes in 6D EGB gravity whose
properties are sufficiently physically interesting. Superpotentials for
arbitrary types of perturbations on arbitrary curved backgrounds, recently
obtained by the author, are used, and acceptable mass and mass flux are
obtained. A possibility of considering the KK created matter as dark matter in
the Universe is discussed.Comment: 15 pages, no figures, minor changes related to the Journal
publication with adding two references in footnote
The Quantum Propagator for a Nonrelativistic Particle in the Vicinity of a Time Machine
We study the propagator of a non-relativistic, non-interacting particle in
any non-relativistic ``time-machine'' spacetime of the type shown in Fig.~1: an
external, flat spacetime in which two spatial regions, at time and
at time , are connected by two temporal wormholes, one leading from
the past side of to t the future side of and the other from the
past side of to the future side of . We express the propagator
explicitly in terms of those for ordinary, flat spacetime and for the two
wormholes; and from that expression we show that the propagator satisfies
completeness and unitarity in the initial and final ``chronal regions''
(regions without closed timelike curves) and its propagation from the initial
region to the final region is unitary. However, within the time machine it
satisfies neither completeness nor unitarity. We also give an alternative proof
of initial-region-to-final-region unitarity based on a conserved current and
Gauss's theorem. This proof can be carried over without change to most any
non-relativistic time-machine spacetime; it is the non-relativistic version of
a theorem by Friedman, Papastamatiou and Simon, which says that for a free
scalar field, quantum mechanical unitarity follows from the fact that the
classical evolution preserves the Klein-Gordon inner product
Production of Rabbit Anti-Rabies Immunoglobulin Using Cultural Antigen
Justified is the possibility of application of fixed rabies virus Moscow 3253, reproduced on the cell culture Vero, as an antigen for heterologous anti-rabies immunoglobulin production. Application of the adjuvant - aluminium hydrate - is determined to be effective. Herein, by the day 73 post immunization, specific antibodies titer is ≥ 1:500 (wherein specific activity has been identified by means of neutralization test, carried out on white mice, and dot-blot immunoassay). The level of specific activity in experimental samples of anti-rabies immunoglobulin, isolated from rabbit immune serum, corresponds to 332 and 347 ME/ml. Physicochemical and biological properties of anti-rabies immunoglobulin, produced with the help of cultural antigen, fully comply with regulatory requirements specified for commercial preparation of heterologous anti-rabies immunoglobulin
СРАВНИТЕЛЬНЫЙ АНАЛИЗ МЕТОДИК РЕНТГЕНОФЛУОРЕСЦЕНТНОГО ОПРЕДЕЛЕНИЯ ЭЛЕМЕНТНОГО СОСТАВА АРХЕОЛОГИЧЕСКОЙ КЕРАМИКИ ИЗ МАЛЫХ НАВЕСОК
Wavelength-dispersive X-ray fluorescence analysis (WDXRF) and total-reflection X-ray fluorescence (TXRF) analysis were applied to study the elemental composition of the Late Neolithic ancient ceramics collected at the Popovsky Lug burial site (Kachug, Upper Lena river, Russia). Semi-quantitative non-destructive analysis of ceramic pieces showed that measurements of the upper and lower sides of the ceramic are less informative than the measurement of its cut. Various sample preparation techniques for the low quantity of crushed ceramics such as fusion, pressing and preparation of suspensions were compared to preserve the material. Samples were prepared as 150 mg fused beads and 250 mg pressed pellets for WDXRF, and as suspensions of 20 mg sample based on the aqueous solution of the Triton X-100 surfactant for TXRF. Certified methods were used to validate the obtained contents of rock-forming oxides and inductively coupled plasma mass spectrometry was used to confirm the results of trace elements determination. Based on the carried-out studies, a combination of the wavelength-dispersive X-ray fluorescence analysis (glass) and total-reflection X-ray fluorescence analysis (suspension) methods was chosen to obtain the data on the elemental bulk composition of archaeological ceramics. The proposed combination allowed the quantitative determination of Na, Mg, Al, Si, P, K, Ca, Ti, Mn, Fe, V, Cr, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Pb, and Ba from the sample of crushed ceramics weighing only about 170 mg.Keywords: wavelength-dispersive X-ray fluorescence analysis, total reflection X-ray fluorescence analysis, ceramics, archeology, Popovsky Lug, Upper Lena River DOI: http://dx.doi.org/10.15826/analitika.2020.25.1.001 G.V. Pashkova1,2, M.M. Mukhamedova1,2, V.M. Chubarov1,3, A.S. Maltsev1,4,A.A. Amosova3, E.I. Demonterova1, E.A. Mikheeva1, D.L. Shergin1,2,5, V.A. Pellinen1, A.V. Teten'kin1,4 1Institute of the Eatrh’s Crust, SB RAS, 128 Lermontov St., 640033, Irkutsk, Russian Federation2Irkutsk State University, 1 K. Marx St., 664003, Irkutsk, Russian Federation3Vinogradov Institute of Geochemistry, SB RAS, 1А Favorsky st., 664033, Irkutsk, Russian Federation4Irkutsk National Research Technical University, 83 Lermontov st., 664074, Irkutsk, Russian Federation5Irkutsk Regional Museum of Local Lore; 13 K. Marx st., 664003, Irkutsk, Russian FederationДля изучения элементного состава древней керамики эпохи позднего неолита стоянки-могильника Поповский Луг (район поселка Качуг, верховье реки Лены, Россия) использованы два варианта рентгенофлуоресцентного анализа: традиционный рентгенофлуоресцентный анализ с волновой дисперсией (WDXRF) и рентгенофлуоресцентный анализ с полным внешним отражением (TXRF). Приближенно-количественный анализ фрагментов керамики без измельчения показал, что измерения внешней и внутренней поверхности фрагментов керамики являются менее информативными, по сравнению с измерением ее среза. Апробированы способы подготовки проб, ориентированные на анализ малых навесок измельченной керамики с целью сохранения материала: сплавление, прессование и приготовление суспензий. Для WDXRF излучатели готовили в виде сплавленных стекол из 150 мг пробы, а также в виде прессованных таблеток из 250 мг пробы. Для проведения TXRF использовали суспензии из 20 мг пробы на основе водного раствора поверхностно-активного вещества Triton X-100. В качестве методик сравнения при определении породообразующих оксидов применяли аттестованные методики количественного химического анализа, при определении микроэлементов – метод масс-спектрометрии с индуктивно-связанной плазмой. Проведенные исследования показали, что для получения данных об элементном валовом составе археологической керамики предпочтительно использование комбинации методов WDXRF (стекло) и TXRF (суспензия). Предложенная схема позволяет проводить количественное определение Na, Mg, Al, Si, P, K, Ca, Ti, Mn, Fe, V, Cr, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Pb и Ba из навески измельченной керамики массой примерно 170 мг.Ключевые слова: рентгенофлуоресцентный анализ с волновой дисперсией, рентгенофлуоресцентный анализ с полным внешним отражением, керамика, археология, Поповский Луг, Верхняя ЛенаDOI: http://dx.doi.org/10.15826/analitika.2020.25.1.00
Кафедре педиатрии Российской медицинской академии непрерывного профессионального образования — 85 лет: от прошлого к будущему
.
Observational Manifestations of the First Protogalaxies in the 21 cm Line
The absorption properties of the first low-mass protogalaxies (mini-halos)
forming at high redshifts in the 21-cm line of atomic hydrogen are considered.
The absorption properties of these protogalaxies are shown to depend strongly
on both their mass and evolutionary status. The optical depths in the line
reach 0.1-0.2 for small impact parameters of the line of sight. When a
protogalaxy being compressed, the influence of gas accretion can be seen
manifested in a non-monotonic frequency dependence of the optical depth. The
absorption characteristics in the 21-cm line are determined by the thermal and
dynamical evolution of the gas in protogalaxies. Since the theoretical line
width in the observer's reference frame is 1-6 kHz and the expected separation
between lines 8.4 kHz, the lines from low mass protogalaxies can be resolved
using ongoing and future low frequency interferometers.Comment: 12 pages, 5 figure
СОСТОЯНИЕ ОБМЕНА ВЕЩЕСТВ, ОРГАНОВ ПИЩЕВАРЕНИЯ, РЕПРОДУКТИВНОЙ СИСТЕМЫ И ДИСТАЛЬНЫХ ОТДЕЛОВ КОНЕЧНОСТЕЙКРУПНОГО РОГАТОГО СКОТА В УДМУРТСКОЙ РЕСПУБЛИКЕ
The paper explores metabolic peculiarities, immune-biochemical status of mother-cows and their calves in breed livestock farms and commercial farm of the Udmurtian Republic. The authors outline relation between defects of biochemical blood parameters and pathology of digestive apparatus, reproductive system and distal limbs. The article reflects data on the status of digestible apparatus, distal limbs and reproductive system of cows in breed livestock farms and peculiarities of endocrine capacities. The publication contains data on fertility, status and quality of feeding, proportion of diseases and cow disposal. The authors determine gynecological diseases, mastitis and limbs disease of cows in the Udmurtian Republic in 2012–2014 whereas process defect is 37 %. Analysis of blood serum shows low and medium asidoses 38–75.7 % and 90 % in some districts. The authors determine the reasons of calves aged 3–4 months age reponse to pneumoenteritis. The research recommends arranging cows and calves feeding according to fertility and metabolic status, making balance in protein consumption, sugar, microelements and macroelements and vitamins. The researchers suggest arranging forage conservation and storage and sufficient feeding with concentrated feeds; making herd high immunity with application of vaccines and natural resistance adjusted for metabolism and medical aids.Изучены особенности обмена веществ у коров в племенных и товарных хозяйствах Удмуртской Республики, в том числе иммунобиохимического статуса коров-матерей и полученных от них телят. Определена взаимосвязь нарушений биохимических показателей крови с патологией органов пищеварения, репродуктивной системы и дистальных отделов конечностей. В работе изложены материалы о состоянии органов пищеварения, дистальных отделов конечностей и репродуктивной системы у коров в племенных хозяйствах, а также об особенностях работы эндокринных органов. Отражены данные о продуктивности, состоянии и качестве кормления, удельном весе заболеваний и выбраковке молочных коров за ряд лет. В структуре болезней коров по Удмуртской Республике за 2012–2014 гг. первое место занимают гинекологические болезни, второе – маститы и третье – болезни конечностей. На технологический брак приходится всего в среднем 37%. Анализ данных показателей сыворотки крови свидетельствует о наличии ацидозов слабой и средней степени тяжести – от 38 до 75,7% по стаду, а в некоторых районах до 90%. Определены причины восприимчивости телят до 3–4-месячного возраста к пневмоэнтеритам. На основании исследований рекомендовано организовывать уровень кормления коров и телят в зависимости не только от продуктивности, но и от состояния обмена веществ, балансируя корма по потребности в белке, сахарах, микро-, макроэлементах и витаминах; совершенствовать технологии заготовки и хранения кормов, проводить надлежащую подготовку концентрированных кормов к скармливанию; создавать стадный иммунитет высокого уровня с подбором необходимых вакцин и уровень естественной резистентности с учетом обмена веществ и применяемых медикаментозных средств
- …