Asymmetric Faraday Effect in a Magnetophotonic Crystal

It is widely known that the magneto-optical Faraday effect is linear in magnetization and therefore the Faraday angles for the states with opposite magnetizations are of opposite sign but equal in modulus. Here we experimentally study propagation of light through a one-dimensional all-garnet magnetophotonic crystal to demonstrate an asymmetric Faraday effect (AFE) for which Faraday angles for opposite magnetic states differ not only in sign but in the absolute value as well. AFE appears in the vicinity of the cavity resonance for an oblique incidence of light which plane of polarization is inclined to the incidence plane. Under proper incidence and polarization angles the magnitude of AFE could be very large reaching 30% of the absolute value of the Faraday effect. The effect originates from the difference in Q-factors for p- and s- polarized cavity modes that breaks the symmetry between the two opposite directions of polarization rotation. The discovered AFE is of prime importance for nanoscale magnonics and optomagnetism.Comment: Supplementary information provided after the main tex

Practices of Protest in the Conditions of the Developing Academic Capitalism

The article focuses on the problem of professional motivation of University teaching staff in the context of developing “academic capitalism” and presents the results of the empirical study carried out by the authors at the North-Western Institute of management of RANEPA in March–June 2020. Based on the data obtained, it is revealed that teachers, experiencing deep deprivation of their social needs – the needs for respect, recognition and honor, are trying to find their place in the modern system, get out of the grip of double pressure, on the one hand, from the administration, which purposefully imposes rating systems and effective contracts, increasing competition between teachers, and on the other hand – students, who are now positioned as clients of universities. In the context of developing academic capitalism, teachers choose one of two adaptation strategies: 1) conformism as an opportunity to integrate into a constantly changing situation; 2) the practice of quiet protest as an opportunity to demonstrate the inefficiency of the entrepreneurial model of higher education, at least in its current version, and 3) neutral position to protect the classical values of the academic community

Pulsation in the atmosphere of the roAp star HD 24712. I. Spectroscopic observations and radial velocity measurements

We have investigated the structure of the pulsating atmosphere of one of the best studied rapidly oscillating Ap stars, HD 24712. For this purpose we analyzed spectra collected during 2001-2004. An extensive data set was obtained in 2004 simultaneously with the photometry of the Canadian MOST mini-satellite. This allows us to connect directly atmospheric dynamics observed as radial velocity variations with light variations seen in photometry. We directly derived for the first time and for different chemical elements, respectively ions, phase shifts between photometric and radial velocity pulsation maxima indicating, as we suggest, different line formation depths in the atmosphere. This allowed us to estimate for the first time the propagation velocity of a pulsation wave in the outer stellar atmosphere of a roAp star to be slightly lower than the sound speed. We confirm large pulsation amplitudes (150-400 m/s) for REE lines and the Halpha core, while spectral lines of the other elements (Mg, Si, Ca, and Fe-peak elements) have nearly constant velocities. We did not find different pulsation amplitudes and phases for the lines of rare-earth elements before and after the Balmer jump, which supports the hypothesis of REE concentration in the upper atmosphere above the hydrogen line-forming layers. We also discuss radial velocity amplitudes and phases measured for individual spectral lines as tools for a 3D tomography of the atmosphere of HD 24712.Comment: accepted by A&

Protecting Mice from H7 Avian Influenza Virus by Immunisation with a Recombinant Adenovirus Encoding Influenza A Virus Conserved Antigens

Influenza is a highly contagious disease that causes annual epidemics and occasional pandemics. Birds are believed to be the source of newly emerging pandemic strains, including highly pathogenic avian influenza viruses of the subtype H7. The aim of the study: to evaluate the ability of the recombinant human adenovirus, serotype 5, which expresses genes of influenza A highly conserved antigens (ion channel M2 and nucleoprotein NP), to provide protection to laboratory mice against infection with a lethal dose of avian influenza virus, subtype H7. To achieve this goal, it was necessary to adapt influenza A virus, subtype H7 for reproduction in the lungs of mice, to characterise it, and to use it for evaluation of the protective properties of the recombinant adenovirus. Materials and methods: avian influenza virus A/Chicken/NJ/294508-12/2004 (H7N2) was adapted for reproduction in the lungs of mice by repeated passages. The adapted strain was sequenced and assessed using hemagglutination test, EID50 and LD50 for laboratory mice. BALB/c mice were immunised once with Ad5-tet-M2NP adenovirus intranasally, and 21 days after the immunisation they were infected with a lethal dose (5 LD50) of influenza virus A/Chicken/NJ/294508-12/2004 (H7N2) in order to assess the protective properties of the recombinant adenovirus. The level of viral shedding from the lungs of the infected mice was evaluated by titration of the lung homogenates in MDCK cell culture on days 3 and 6 after infection. The level of specific antibodies to H7 avian influenza virus was determined by indirect enzyme immunoassay. Results: the use of Ad5-tet-M2NP adenovirus for immunisation of the mice ensured 100% survival of the animals that had disease symptoms (weight loss) after their infection with the lethal dose (5 LD50) of H7 avian influenza virus. The study demonstrated a high post-vaccination level of humoral immune response to H7 avian influenza virus. The virus titer decreased significantly by day 6 in the lungs of mice that had been immunised with Ad5-tet-M2NP compared to the control group. Conclusion: the Ad5-tetM2NP recombinant adenovirus can be used to create a candidate pandemic influenza vaccine that would protect against avian influenza viruses, subtype H7, in particular

The adaptive potential of North American subtype H7N2 avian influenza viruses to mammals

Introduction. H7 subtype avian influenza viruses causing severe epizootics among birds are phylogenetically different in the Eastern and Western hemispheres. Numerous human infections caused by these viruses in the Eastern hemisphere indicate that H7 viruses can overcome the interspecies barrier and pose a potential threat of a new pandemic.The H7N2 viruses with deletion of amino acids 221–228 (H3 numbering) in hemagglutinin (HA) had been circulating among poultry in the Western Hemisphere during 1996–2006, and had once again been detected in 2016 in an animal shelter, where they caused cat diseases. The objective of this study is to elucidate the mechanism of adaptation to mammals of North American H7N2 influenza viruses with deletion in HA. Materials and methods. The A/chicken/New Jersey/294598-12/2004 (H7N2) virus was adapted to mice by the lung passages. Complete genomes of original and mouse-adapted viruses were analyzed. The receptor specificity and thermostability of viruses, HA activation pH and virulence for mice were determined. Results. The non-pathogenic H7N2 avian influenza virus became pathogenic after 10 passages in mice. Amino acid substitutions occurred in five viral proteins: one in PB2 (E627K), NA (K127N), NEP (E14Q), four in HA and six in NS1. Mutations in HA slightly changed receptor specificity but increased the pH of HA activation by 0.4 units. The NS1 protein undergone the greatest changes in the positions (N73T, S114G, K118R, G171A, F214L and G224R), where amino acid polymorphisms were observed in the original virus, but only minor amino acid variants have been preserved in the mouse adapted variant. Conclusion. The results show that H7N2 viruses have the potential to adapt to mammals. The increase in virulence is most likely due to the adaptive E627K mutation in PB2 and possibly in HA

Защита мышей от заражения вирусом гриппа птиц субтипа H7 с помощью иммунизации рекомбинантным аденовирусом, кодирующим консервативные антигены вируса гриппа А

Influenza is a highly contagious disease that causes annual epidemics and occasional pandemics. Birds are believed to be the source of newly emerging pandemic strains, including highly pathogenic avian influenza viruses of the subtype H7. The aim of the study: to evaluate the ability of the recombinant human adenovirus, serotype 5, which expresses genes of influenza A highly conserved antigens (ion channel M2 and nucleoprotein NP), to provide protection to laboratory mice against infection with a lethal dose of avian influenza virus, subtype H7. To achieve this goal, it was necessary to adapt influenza A virus, subtype H7 for reproduction in the lungs of mice, to characterise it, and to use it for evaluation of the protective properties of the recombinant adenovirus. Materials and methods: avian influenza virus A/Chicken/NJ/294508-12/2004 (H7N2) was adapted for reproduction in the lungs of mice by repeated passages. The adapted strain was sequenced and assessed using hemagglutination test, EID50 and LD50 for laboratory mice. BALB/c mice were immunised once with Ad5-tet-M2NP adenovirus intranasally, and 21 days after the immunisation they were infected with a lethal dose (5 LD50) of influenza virus A/Chicken/NJ/294508-12/2004 (H7N2) in order to assess the protective properties of the recombinant adenovirus. The level of viral shedding from the lungs of the infected mice was evaluated by titration of the lung homogenates in MDCK cell culture on days 3 and 6 after infection. The level of specific antibodies to H7 avian influenza virus was determined by indirect enzyme immunoassay. Results: the use of Ad5-tet-M2NP adenovirus for immunisation of the mice ensured 100% survival of the animals that had disease symptoms (weight loss) after their infection with the lethal dose (5 LD50) of H7 avian influenza virus. The study demonstrated a high post-vaccination level of humoral immune response to H7 avian influenza virus. The virus titer decreased significantly by day 6 in the lungs of mice that had been immunised with Ad5-tet-M2NP compared to the control group. Conclusion: the Ad5-tetM2NP recombinant adenovirus can be used to create a candidate pandemic influenza vaccine that would protect against avian influenza viruses, subtype H7, in particular.Грипп – высококонтагиозное заболевание, вызывающее ежегодные эпидемии и через неравные интервалы времени – пандемии. Источником вновь возникающих пандемичных штаммов, как правило, являются птицы, а наибольшее беспокойство в настоящее время вызывают высокопатогенные вирусы гриппа птиц субтипа H7. Цель работы: оценить способность рекомбинантного аденовируса человека пятого серотипа, экспрессирующего гены высококонсервативных антигенов вируса гриппа А (ионного канала М2 и нуклеопротеина NP), обеспечивать защиту от заражения лабораторных мышей летальной дозой вируса гриппа птиц субтипа H7. Для достижения цели необходимо было адаптировать для размножения в легких мышей вирус гриппа А субтипа Н7, охарактеризовать и с его помощью оценить защитные свойства рекомбинантного аденовируса. Материалы и методы: вирус гриппа птиц A/Chicken/NJ/294508-12/2004 (H7N2) был адаптирован для размножения в легких мышей путем многократного пассирования. Этот штамм был секвенирован и охарактеризован в реакции гемагглютинации, установлены его ЭИД50 и ЛД50 для лабораторных мышей. Для изучения защитных свойств рекомбинантного аденовируса мыши линии BALB/c были иммунизированы аденовирусом Ad5-tet-M2NP однократно интраназально и через 21 сутки после иммунизации заражены летальной дозой (5 ЛД50) вируса гриппа птиц A/Chicken/NJ/294508-12/2004 (H7N2). Уровень вирусовыделения из легких мышей был оценен на 3 и 6 сутки после заражения с помощью титрования гомогенатов легких на культуре клеток MDCK. Уровень специфических антител к вирусу гриппа птиц субтипа Н7 определяли методом непрямого иммуноферментного анализа. Результаты: иммунизация мышей аденовирусом Ad5-tet-M2NP при наличии симптомов заболевания (снижение массы тела) обеспечила 100% выживаемость животных после заражения летальной дозой (5 ЛД50) вируса гриппа птиц субтипа H7. Продемонстрирован высокий поствакцинальный уровень гуморального иммунного ответа к вирусу гриппа птиц субтипа H7. Показано, что в легких мышей из группы, иммунизированной Ad5-tet-M2NP, уже к 6 суткам наблюдалось существенное снижение титра вируса гриппа птиц субтипа H7 по сравнению с контрольной группой. Заключение: рекомбинантный аденовирус Ad5-tet-M2NP может быть использован для создания потенциальной пандемичной противогриппозной вакцины, в том числе и от вирусов гриппа птиц субтипа H7