Effects of Grass Fires on the Trajectory of Vegetation Dynamics in Abandoned Agricultural Lands: A 30-year Retrospective Based on Remote Sensing Data (A Study of an Area South of the Moscow Region)

The authors propose that the spatial structure of woody vegetation on former arable lands can be used as a diagnostic feature that indicates the occurrence or absence of grass fires after land abandonment. Based on the analysis of a series of Landsat satellite images from 1985 to 2016 for an area of 256.5 km2located in Central European Russia, the authors have reconstructed the history of spring fire events. They found correlations between the frequency of fire events and the density and spatial structure of woody vegetation on abandoned arable lands. Without fires, areas with homogeneous woody vegetation are formed: individuals of pioneer tree species (Betula pendula, B. pubescens and Salix caprea) are evenly distributed and exist in highdensities over the entire area. Affected by fires, trees become unevenly distributed over the area: pioneer trees grow in groups or as separate individuals depending on the intensity and frequency of grass fires. With frequent fires, the vegetation remains in a weedy stage for decades. Keywords: abandoned agricultural lands (old-fields), Earth remote sensing data, Landsat, grass fire, spatial structure of woody vegetatio

The Effect of Focusing and Caustics on Exit Phenomena in Systems Lacking Detailed Balance

We study the trajectories followed by a particle subjected to weak noise when escaping from the domain of attraction of a stable fixed point. If detailed balance is absent, a _focus_ may occur along the most probable exit path, leading to a breakdown of symmetry (if present). The exit trajectory bifurcates, and the exit location distribution may become `skewed' (non-Gaussian). The weak-noise asymptotics of the mean escape time are strongly affected. Our methods extend to the study of skewed exit location distributions in stochastic models without symmetry.Comment: REVTEX macros (latest version). Two accompanying PS figures, one of which is large (over 600K unpacked

Manifestation of Huntington's disease pathology in human induced pluripotent stem cell-derived neurons

© 2016 Nekrasov et al.Background: Huntington's disease (HD) is an incurable hereditary neurodegenerative disorder, which manifests itself as a loss of GABAergic medium spiny (GABA MS) neurons in the striatum and caused by an expansion of the CAG repeat in exon 1 of the huntingtin gene. There is no cure for HD, existing pharmaceutical can only relieve its symptoms. Results: Here, induced pluripotent stem cells were established from patients with low CAG repeat expansion in the huntingtin gene, and were then efficiently differentiated into GABA MS-like neurons (GMSLNs) under defined culture conditions. The generated HD GMSLNs recapitulated disease pathology in vitro, as evidenced by mutant huntingtin protein aggregation, increased number of lysosomes/autophagosomes, nuclear indentations, and enhanced neuronal death during cell aging. Moreover, store-operated channel (SOC) currents were detected in the differentiated neurons, and enhanced calcium entry was reproducibly demonstrated in all HD GMSLNs genotypes. Additionally, the quinazoline derivative, EVP4593, reduced the number of lysosomes/autophagosomes and SOC currents in HD GMSLNs and exerted neuroprotective effects during cell aging. Conclusions: Our data is the first to demonstrate the direct link of nuclear morphology and SOC calcium deregulation to mutant huntingtin protein expression in iPSCs-derived neurons with disease-mimetic hallmarks, providing a valuable tool for identification of candidate anti-HD drugs. Our experiments demonstrated that EVP4593 may be a promising anti-HD drug

КЛИНИКО-ЭПИДЕМИОЛОГИЧЕСКАЯ ХАРАКТЕРИСТИКА КОРИ У ВЗРОСЛЫХ ЖИТЕЛЕЙ АЛТАЙСКОГО КРАЯ

The aim of the study is to determine the clinical and epidemiological features of measles in the Altai territory. Materials and methods: a retrospective analysis of 92 medical histories of inpatient patients with a confirmed diagnosis of «Measles» at the age of 17 to 54 years, who were treated in the Infectious Departments of City Hospitals № 5 and №11 in Barnaul in 2015–2018, was made. Results: the epidemic situation of measles in the Altai territory is characterized by an increase of morbidity rate in 2015, as well as isolated cases in 2017–2018. The peculiarity of the outbreak of the disease was in-hospital infection of patients upon admission to medical hospitals and late diagnosis of measles, as well as the importation of infection from adjacent territories (regions of Russia and the Republic of Kazakhstan), which is confirmed by genotyping of the virus in patients. The development of the disease in 23,9% of those,who were vaccinated, was routinely observed in the age group older than 30 years. In the clinical picture of measles at the present stage, along with the classical manifestations, in 15.2% of patients in the first days of the disease gastroenteritis was marked, in 40,2% of patients the signs of hepatitis (cytolysis syndrome) were observed. Conclusion: the prevalence among the patientspersons, older than 30 years, may indicate the extinction of post-vaccination immunity. Timely immunization against measles in adulthood (after 30 years), will increase the effectiveness of measures to implement the program of elimination of measles in the Altai territory. The development of gastroenteritis up to the 5 days of the disease (on average 2,5±0.9 days), hepatitis in the period of height of the disease (in 15,2% and 40,2% of patients, respectively), determined the erroneous diagnosis of «Enterovirus infection», pseudotuberculosis, etc. and deserved the attention of practitioners.Цель: определить клинико-эпидемиологические особенности кори у взрослых на территории Алтайского края. Материалы и методы: проведен ретроспективный анализ 92 медицинских карт стационарного больного пациентов с подтвержденным диагнозом «Корь» в возрасте от 17 до 54 лет, находившихся на лечении в инфекционных отделениях КГБУЗГБ № 5 и № 11 г. Барнаула в 2015–2018 гг. Результаты: эпидемическая ситуация по кори в Алтайском крае характеризуется подъемом заболеваемости в 2015 г., а также единичными случаями в 2017– 2018 гг. Эпидемиологическими особенностями явились завоз инфекции из сопредельных территорий и из-за рубежа (Республики Казахстан, Турции, Мальдивских островов), несвоевременное установление диагноза кори при поступлении в медицинское учреждение и, как следствие, внутрибольничное инфицирование. Завозной характер инфекции подтвержден генотипированием вируса у заболевших. Развитие заболевания у 23,9% вакцинированных в плановом порядке наблюдалось в возрастной группе старше 30 лет. В клинической картине кори на современном этапе, наряду с классическими проявлениями, у 15,2% пациентов в первые дни болезни отмечены явления гастроэнтерита, у 40,2% заболевших – признаки гепатита (синдром цитолиза). Заключение: преобладание среди больных лиц старше 30 лет может свидетельствовать об угасании постпрививочного иммунитета. Дополнительное проведение иммунизации против кори в зрелом возрасте (после 30 лет) повысит эффективность мероприятий по реализации программы элиминации кори на территории Алтайского края. Развитие синдрома гастроэнтерита до 5-го дня болезни (в среднем на 2,5±0,9 сутки), гепатита в периоде разгара (у 15,2% и 40,2% больных соответственно) определяло постановку ошибочного диагноза «Энтеровирусная инфекция», «Псевдотуберкулез» и т.д. и заслуживает внимания практикующих врачей

THE HISTORY OF FIRES IN OLD-GROWTH KOREAN PINE – BROADLEAVED FORESTS IN THE MIDDLE REACHES OF THE BIKIN RIVER (WESTERN SLOPE OF THE SYKHOTE-ALIN MOUNTAINS) ACCORDING TO DENDROCHRONOLOGICAL AND PEDOANTHRACOLOGICAL DATA

The largest unfragmented tract of the rich-in-species old-growth Korean pine (Pinus koraiensis)- broadleaved forests in the world is situated in the basin of the Bikin River. The history of these forests, including the fire history, is very important for understanding factors of dynamics of these forests and prognosis of their development under different climate change scenarios and land-use regimes. However, this history has not been studied in detail so far. Here we aim at reconstructing the local history of fires in the middle reaches of the Bikin River using dendrochronology and pedoanthracology (analysis of charcoal in the soil). We used treefall mounds to search for charcoal in soils; charcoal was selected from 34 treefall mounds, 14 charcoal samples were radiocarbon dated. The age of fire scars on trunks was determined using the increment borer method on 45 Pinus koraiensis individuals. We defined that the main factors responsible for charcoal transport to the mineral soils were past treefalls with uprooting and soil erosion. The most ancient soil charcoals date back to the Upper Neolithic, about 3450 cal BP. The remaining charcoal samples are mainly grouped into four clusters: about 2250, 1610, 1450 and 600 cal BP. The increase of fire frequency is in good agreement with the previous results of lithologic-facies, botanical, spore-pollen and other analyses of bog sediments in the floodplain of the Bikin River. The earliest fires in the study area, which can be associated with human impacts, refer to the end of the first millennium (the time of the Bohai Kingdom). Fire scars were found on cores sampled from 39 out of 45 Pinus koraiensis individuals. The oldest Pinus we dated was 278 years old. Based on the cores, a fire chronology was built, covering the period from 1773 to 1993. Fires were marked for 36 years, while 10 years of them coincided in 3 and more cores. The periods with the highest frequency of fires are from 1937 to 1948 and from 1958 to 1980. We further followed possible connections between the frequency of fires and human activities. We also compared the fire chronology, data on precipitation and the number of fires in the Sikhote-Alin State Nature Reserve located closely to the study area. As expected, fires often occurred in the years with low precipitation or in the years following them. Preservation of a high species diversity of plants, especially the woody ones, with a significant frequency of fires in the study area can be explained by a complex relief determining the local fire spread and the presence of fire refugia. Soil charcoal analysis showed the existence of fire events from 3500 to 600 years BP and tree fire scars analysis showed the intensive fire history of the studied forests during the last 200 years. For the first time, fire regimes were reconstructed for Korean pine-broadleaved forest located on the slopes in the middle reaches of the Bikin River

The ecosystem approach to the reconstruction of the natural environment of ancient and medieval societies

Раскрывается важность экосистемного подхода для реконструкции природного окружения древних обществ.We developed an ecosystem approach to reconstruct an ecosystem history. For the proper reconstruction of the natural environment of ancient and medieval societies it is important to distinguish following points in the ecosystem history: (1) stages of spontaneous (free) dynamics of ecosystems when their changes are caused by the action of endogenous biotic factors; (2) stages of a plot existence in the form of agricultural land and (3) stages of successional dynamics after the action of anthropogenic factors such as fire or burning, plowing, cattle grazing, etc., and other exogenous factors. It is important to understand differences between the autogenous and allogenic successions. Methodically, this approach is based on a reconstruction of the historical events of particular ecosystems and on identification of factors that determined these events. Reconstruction can be performed by using a complex of methods combining the techniques of soil morphology, radiocarbon dating of charcoal fragments in soil, methods of palynology and analysis of historical data (for the last few centuries). Using of the soil morphological technique one can successfully reconstruct the traces of burrowing activity of the soil animals, old tree roots, ancient pits formed after treefalls; among the human impacts, traces of plowing and fires are easy recognized by this technique. The age of charcoal fragments shows the time of fire (or burning). The information of the form, size, location and occurrence of the charcoal pieces in soil can indicate the time and intensity of forest fires in the remote past as well as the events associated with fires, such as tree falls, plowing, etc. Radiocarbon dating allows us to synchronize the palyological information and data of a soil development in the study plots