Five new species of Eoptychopteridae (Diptera) from the Mesozoic of Asia

Five new species of the extinct family Eoptychopteridae are described from Asia. They are Eoptychoptera shurabica n.sp. (Lower or Middle Jurassic, Kyrgyzstan), E. elevata n.sp., Propty chopterina immensa n.sp., P. tenera n.sp. (last three from the Upper Jurassic or Lower Cretaceous, Siberia), and P. makarov a n.sp. (Lower Jurassic, Siberia).Five new species of the extinct family Eoptychopteridae are described from Asia. They are Eoptychoptera shurabica n.sp. (Lower or Middle Jurassic, Kyrgyzstan), E. elevata n.sp., Propty chopterina immensa n.sp., P. tenera n.sp. (last three from the Upper Jurassic or Lower Cretaceous, Siberia), and P. makarov a n.sp. (Lower Jurassic, Siberia)

Rational Solutions of the Painleve' VI Equation

In this paper, we classify all values of the parameters $\alpha$, $\beta$, $\gamma$ and $\delta$ of the Painlev\'e VI equation such that there are rational solutions. We give a formula for them up to the birational canonical transformations and the symmetries of the Painlev\'e VI equation.Comment: 13 pages, 1 Postscript figure Typos fixe

The Hamiltonian Structure of the Second Painleve Hierarchy

In this paper we study the Hamiltonian structure of the second Painleve hierarchy, an infinite sequence of nonlinear ordinary differential equations containing PII as its simplest equation. The n-th element of the hierarchy is a non linear ODE of order 2n in the independent variable $z$ depending on n parameters denoted by ${t}_1,...,{t}_{n-1}$ and $\alpha_n$. We introduce new canonical coordinates and obtain Hamiltonians for the $z$ and $t_1,...,t_{n-1}$ evolutions. We give explicit formulae for these Hamiltonians showing that they are polynomials in our canonical coordinates

Mesozoic fossils (>145 Mya) suggest the antiquity of the subgenera of Daphnia and their coevolution with chaoborid predators

<p>Abstract</p> <p>Background</p> <p>The timescale of the origins of <it>Daphnia </it>O. F. Mueller (Crustacea: Cladocera) remains controversial. The origin of the two main subgenera has been associated with the breakup of the supercontinent Pangaea. This vicariance hypothesis is supported by reciprocal monophyly, present day associations with the former Gondwanaland and Laurasia regions, and mitochondrial DNA divergence estimates. However, previous multilocus nuclear DNA sequence divergence estimates at < 10 Million years are inconsistent with the breakup of Pangaea. We examined new and existing cladoceran fossils from a Mesozoic Mongolian site, in hopes of gaining insights into the timescale of the evolution of <it>Daphnia</it>.</p> <p>Results</p> <p>We describe new fossils of ephippia from the Khotont site in Mongolia associated with the Jurassic-Cretaceous boundary (about 145 MYA) that are morphologically similar to several modern genera of the family Daphniidae, including the two major subgenera of <it>Daphnia</it>, i.e., <it>Daphnia </it>s. str. and <it>Ctenodaphnia</it>. The daphniid fossils co-occurred with fossils of the predaceous phantom midge (Chaoboridae).</p> <p>Conclusions</p> <p>Our findings indicate that the main subgenera of <it>Daphnia </it>are likely much older than previously known from fossils (at least 100 MY older) or from nuclear DNA estimates of divergence. The results showing co-occurrence of the main subgenera far from the presumed Laurasia/Gondwanaland dispersal barrier shortly after formation suggests that vicariance from the breakup of Pangaea is an unlikely explanation for the origin of the main subgenera. The fossil impressions also reveal that the coevolution of a dipteran predator (Chaoboridae) with the subgenus <it>Daphnia </it>is much older than previously known -- since the Mesozoic.</p

Brucellosis: Trends in the Development of Situation in the World and Forecast for 2022 in the Russian Federation

An analysis of trends in the development of situation on brucellosis in the world over past decade and the data on the main risk factors for the occurrence of epidemiological complications regarding this infection in various regions of the world are provided in the paper. An expert assessment of the current epizootiological and epidemiological situation on brucellosis, the coverage of population and animals with immunization in the Russian Federation is given. Over 9 months of 2021, 210 potentially hazardous as regards brucellosis in cattle areas and 24 sites – as regards brucellosis in small ruminants – were registered in Russia. Compared to the same period in 2020, there was a decrease in the number of newly identified hazardous sites for bovine brucellosis by 35.8 % (117 areas). However, long-term upward trend in epizootiological adversity for bovine brucellosis in Russia persists. The epidemiological situation on brucellosis in the country for the period of 2012–2021 is characterized as unfavorable. Decrease in the number of newly detected human brucellosis cases (by 25.1 % of long-term average values) is observed against the background of persistent unfavorable epizootic conditions for brucellosis among epidemiologically significant species of small ruminants and cattle in regions with developed animal husbandry. In 2021, clusters of human cases were registered in the Republic of Dagestan and Penza Region. In the Republic of Dagestan, against the background of aggravation of epizootiological and epidemiological situation on brucellosis, there was also an alarming trend towards prevalence of a relatively high incidence among minors. The proportion of cases of brucellosis among children under the age of 17 in the Republic amounted to 60.3 % of the total number of minors with newly diagnosed brucellosis in Russia over the past 10 years. Taking into account current epizootic, epidemic situations and the long-term dynamics of the development of situation on  brucellosis in the Russian Federation, the incidence of brucellosis among the population  is predicted to be 10–15 % lower than the average long-term values – 0.18–0.20 per 100000 of the population – in 2022. The number of human cases of brucellosis can range from 250 to 300

T Cell-Dependence of Lassa Fever Pathogenesis

Lassa virus (LASV), the causative agent of Lassa fever (LF), is endemic in West Africa, accounting for substantial morbidity and mortality. In spite of ongoing research efforts, LF pathogenesis and mechanisms of LASV immune control remain poorly understood. While normal laboratory mice are resistant to LASV, we report that mice expressing humanized instead of murine MHC class I (MHC-I) failed to control LASV infection and develop severe LF. Infection of MHC-I knockout mice confirmed a key role for MHC-I-restricted T cell responses in controlling LASV. Intriguingly we found that T cell depletion in LASV-infected HHD mice prevented disease, irrespective of high-level viremia. Widespread activation of monocyte/macrophage lineage cells, manifest through inducible NO synthase expression, and elevated IL-12p40 serum levels indicated a systemic inflammatory condition. The absence of extensive monocyte/macrophage activation in T cell-depleted mice suggested that T cell responses contribute to deleterious innate inflammatory reactions and LF pathogenesis. Our observations in mice indicate a dual role for T cells, not only protecting from LASV, but also enhancing LF pathogenesis. The possibility of T cell-driven enhancement and immunopathogenesis should be given consideration in future LF vaccine development

Analysis of Brucellosis Incidence and Molecular-Genetic Characteristics of Brucella Population in the Territory of the Russian Federation

An analysis of brucellosis incidence in Russia in 2013–2022 and the data on genetic diversity of Brucella melitensis and Brucella abortus populations isolated in Russia in 1939–2022 are provided in the review. Over the past decade, the epidemiological situation in Russia has been characterized as unstable against the background of persistent unfavorable conditions for brucellosis in cattle and small ruminants. During the period of 2013–2022 (9 months), 4298 epizootic foci as regards brucellosis in cattle (89164 sick animals) and 371 as regards brucellosis in small ruminants (13569) were registered. The largest number of epizootic brucellosis foci was recorded in the North-Caucasian and Southern Federal Districts. In 2013–2022, on average, 327 cases of brucellosis among people were registered annually, the incidence rate per 100 000 of the population was 0.24. Up to 70–90 % of brucellosis cases were detected in the south of the European part of the country. A trend towards deterioration of the situation on brucellosis in Volga (Penza and Samara Regions) and Central (Smolensk, Voronezh and Tula Regions) Federal Districts is observed. There is a connection between the intensity of epidemic manifestations of brucellosis and the level of anthropurgic enzooty of territories. In 2022, 467 cases of brucellosis were reported (0.32 per 100 000 of the population), which is 42.8 % higher than annual average values over 10 years. In 2023, a measure of stability of incidence rates, by 20–25 % above average long-term values, is to be expected. Incidence of brucellosis in humans will be within the range of 380–410 cases (0.26–0.28 per 100 000 of the population). The results of genotyping of B. melitensis strains point to an increase in the proportion of isolates with an MLVA-profile characteristic of strains from enzootic as regards brucellosis countries of Middle East and North Africa over past 20–25 years, which can indicate importation (introduction) of the infection from these territories to Russia through small ruminants and/or biomaterial from them

Выбор полимерных микросфер для проведения реакции латексной агглютинации в плашечном формате

Serological tests based on an agglutination reaction are commonly applied in clinical laboratories for the diagnosis of various infectious diseases. There is a wide selection of microsphere-based diagnostic agglutination tests (yes/no results) and assays (quantitative results) worldwide. However, due to rapidity and no need for special equipment passive hemagglutination tests are still the most frequently used routine tests in Russia. These hemagglutination tests are run in 96-well microplates with V-shaped bottoms. The substitution of red blood cells for polymer microspheres in such semi-quantitative tests is difficult due to a number of reasons. When choosing the appropriate microspheres for rapid passive latex agglutination tests, it is important to consider such variables as their size (and size distribution), density and colloidal stability. In our study we showed the development of rapid (1-3 hours) passive latex agglutination tests based on the knowledge of sedimentation stability of polymer suspensions. We studied sedimentation rates of sheep and chicken erythrocytes used in passive hemagglutination tests and identified the required intervals of sedimentation rate for polymer microspheres. Based on these dates a theoretical model of polymer microsphere motion within a V-shaped well was proposed, which revealed that the formation of a lattice in the passive latex agglutination reaction takes place not in the volume of the well, but on the surface of the well bottom.П оказано, что при создании латексного диагностикума для проведения полуколичественного анализа в плашечном формате требуются знания о седиментационной неустойчивости дисперсных систем в гравитационном поле. Создана теоретическая модель движения поли-мерного носителя внутри лунки, которая продемонстрировала, что формирование сетки зацепления из полимерных микросфер при протекании реакции латексной агглютинации в V-образных лунках происходит не в объеме, а на поверхности дна лунки

Tacaribe Virus but Not Junin Virus Infection Induces Cytokine Release from Primary Human Monocytes and Macrophages

The mechanisms underlying the development of disease during arenavirus infection are poorly understood. However, common to all hemorrhagic fever diseases is the involvement of macrophages as primary target cells, suggesting that the immune response in these cells may be of paramount importance during infection. Thus, in order to identify features of the immune response that contribute to arenavirus pathogenesis, we have examined the growth kinetics and cytokine profiles of two closely related New World arenaviruses, the apathogenic Tacaribe virus (TCRV) and the hemorrhagic fever-causing Junin virus (JUNV), in primary human monocytes and macrophages. Both viruses grew robustly in VeroE6 cells; however, TCRV titres were decreased by approximately 10 fold compared to JUNV in both monocytes and macrophages. Infection of both monocytes and macrophages with TCRV also resulted in the release of high levels of IL-6, IL-10 and TNF-α, while levels of IFN-α, IFN-β and IL-12 were not affected. However, we could show that the presence of these cytokines had no direct effect on growth of either TCRV of JUNV in macrophages. Further analysis also showed that while the production of IL-6 and IL-10 are dependent on viral replication, production of TNF-α also occurs after exposure to UV-inactivated TCRV particles and is thus independent of productive virus infection. Surprisingly, JUNV infection did not have an effect on any of the cytokines examined indicating that, in contrast to other viral hemorrhagic fever viruses, macrophage-derived cytokine production is unlikely to play an active role in contributing to the cytokine dysregulation observed in JUNV infected patients. Rather, these results suggest that an early, controlled immune response by infected macrophages may be critical for the successful control of infection of apathogenic viruses and prevention of subsequent disease, including systemic cytokine dysregulation

The Impact of Human Conflict on the Genetics of Mastomys natalensis and Lassa Virus in West Africa

Environmental changes have been shown to play an important role in the emergence of new human diseases of zoonotic origin. The contribution of social factors to their spread, especially conflicts followed by mass movement of populations, has not been extensively investigated. Here we reveal the effects of civil war on the phylogeography of a zoonotic emerging infectious disease by concomitantly studying the population structure, evolution and demography of Lassa virus and its natural reservoir, the rodent Mastomys natalensis, in Guinea, West Africa. Analysis of nucleoprotein gene sequences enabled us to reconstruct the evolutionary history of Lassa virus, which appeared 750 to 900 years ago in Nigeria and only recently spread across western Africa (170 years ago). Bayesian demographic inferences revealed that both the host and the virus populations have gone recently through severe genetic bottlenecks. The timing of these events matches civil war-related mass movements of refugees and accompanying environmental degradation. Forest and habitat destruction and human predation of the natural reservoir are likely explanations for the sharp decline observed in the rodent populations, the consequent virus population decline, and the coincident increased incidence of Lassa fever in these regions. Interestingly, we were also able to detect a similar pattern in Nigeria coinciding with the Biafra war. Our findings show that anthropogenic factors may profoundly impact the population genetics of a virus and its reservoir within the context of an emerging infectious disease