31 research outputs found

    The adventive species community changes in the Cheboksary reservoir during 2001-2021

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    Generally publications devoted to invasive fish species in the Volga-Kama cascade of reservoirs represents relative indicators and do not provide data on the abundance, numbers and invasive communities’ single species dynamics. It does not allow providing a correct assessment of population’s state and changes in the nonindigenous species composition. In this work, changes in the abundance and species structure of the Cheboksary reservoir’s invasive fish community during 2001-2021 were estimated. The total fish count was determined on data of active fishing gears catches and precise reservoir area. Differentiation into mass, widespread and relatively numerous and locally found with a small average abundance species was noted. A decrease in the species evenness of the invasive community was recorded in consequence of the Black Sea-Caspian sprat Clupeonella cultriventris (Nordmann, 1840) and the round goby Neogobius melanostomus (Pallas, 1814) domination rise. The Black Sea-Caspian sprat and the round goby put together for 98.7% of the total number of invasive fish in the current period. Due to this two dominant species there is a tendency to increase the relative abundance of invasive fish species in the reservoir up to 561 unit/ha despite a significant decrease in the abundance of some other invaders

    Photon storage in Lambda-type optically dense atomic media. III. Effects of inhomogeneous broadening

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    In a recent paper [Gorshkov et al., Phys. Rev. Lett. 98, 123601 (2007)] and in the two preceding papers [Gorshkov et al., Phys. Rev. A 76, 033804 (2007); 76, 033805 (2007)], we used a universal physical picture to optimize and demonstrate equivalence between a wide range of techniques for storage and retrieval of photon wave packets in homogeneously broadened Lambda-type atomic media, including the adiabatic reduction of the photon group velocity, pulse-propagation control via off-resonant Raman techniques, and photon-echo-based techniques. In the present paper, we generalize this treatment to include inhomogeneous broadening. In particular, we consider the case of Doppler-broadened atoms and assume that there is a negligible difference between the Doppler shifts of the two optical transitions. In this situation, we show that, at high enough optical depth, all atoms contribute coherently to the storage process as if the medium were homogeneously broadened. We also discuss the effects of inhomogeneous broadening in solid state samples. In this context, we discuss the advantages and limitations of reversing the inhomogeneous broadening during the storage time, as well as suggest a way for achieving high efficiencies with a nonreversible inhomogeneous profile.Comment: 15 pages, 8 figures. V2: minor changes in presentation, new references, higher resolution of figure

    Photon storage in Lambda-type optically dense atomic media. I. Cavity model

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    In a recent paper [Gorshkov et al., Phys. Rev. Lett. 98, 123601 (2007)], we used a universal physical picture to optimize and demonstrate equivalence between a wide range of techniques for storage and retrieval of photon wave packets in Lambda-type atomic media in free space, including the adiabatic reduction of the photon group velocity, pulse-propagation control via off-resonant Raman techniques, and photon-echo-based techniques. In the present paper, we perform the same analysis for the cavity model. In particular, we show that the retrieval efficiency is equal to C/(1+C) independent of the retrieval technique, where C is the cooperativity parameter. We also derive the optimal strategy for storage and, in particular, demonstrate that at any detuning one can store, with the optimal efficiency of C/(1+C), any smooth input mode satisfying T C gamma >> 1 and a certain class of resonant input modes satisfying T C gamma ~ 1, where T is the duration of the input mode and 2 gamma is the transition linewidth. In the two subsequent papers of the series, we present the full analysis of the free-space model and discuss the effects of inhomogeneous broadening on photon storage.Comment: 16 pages, 2 figures. V2: significant changes in presentation, new references, higher resolution of figure

    Permalloy-Based Thin Film Structures: Magnetic Properties and the Giant Magnetoimpedance Effect in the Temperature Range Important for Biomedical Applications

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    Permalloy-based thin film structures are excellent materials for sensor applications. Temperature dependencies of the magnetic properties and giant magneto-impedance (GMI) were studied for Fe19Ni81-based multilayered structures obtained by the ion-plasma sputtering technique. Selected temperature interval of 25 degrees C to 50 degrees C corresponds to the temperature range of functionality of many devices, including magnetic biosensors. A (Cu/FeNi)(5)/Cu/(Cu/FeNi)(5) multilayered structure with well-defined traverse magnetic anisotropy showed an increase in the GMI ratio for the total impedance and its real part with temperature increased. The maximum of the GMI of the total impedance ratio Delta Z/Z = 56% was observed at a frequency of 80 MHz, with a sensitivity of 18%/Oe, and the maximum GMI of the real part Delta R/R = 170% at a frequency of 10 MHz, with a sensitivity of 46%/Oe. As the magnetization and direct current electrical resistance vary very little with the temperature, the most probable mechanism of the unexpected increase of the GMI sensitivity is the stress relaxation mechanism associated with magnetoelastic anisotropy.This work was supported in part by the Russian Foundation for Basic Research under grants mol nr no. 16-32-50054 and by the ELKARTEK grant KK-2016/00030 of the Basque Country Government

    Photon storage in Lambda-type optically dense atomic media. IV. Optimal control using gradient ascent

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    We use the numerical gradient ascent method from optimal control theory to extend efficient photon storage in Lambda-type media to previously inaccessible regimes and to provide simple intuitive explanations for our optimization techniques. In particular, by using gradient ascent to shape classical control pulses used to mediate photon storage, we open up the possibility of high efficiency photon storage in the non-adiabatic limit, in which analytical solutions to the equations of motion do not exist. This control shaping technique enables an order-of-magnitude increase in the bandwidth of the memory. We also demonstrate that the often discussed connection between time reversal and optimality in photon storage follows naturally from gradient ascent. Finally, we discuss the optimization of controlled reversible inhomogeneous broadening.Comment: 16 pages, 7 figures. V2: As published in Phys. Rev. A. Moved most of the math to appendices or removed altogether. Switched order of Sections II and III. Shortened abstract. Added reference

    Cerebrovascular complications of hematopoetic stem cell transplantation in patients with hematologic malignancies

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    Introduction. Modern transplantation and biological therapy methods are associated with a wide range of adverse events and complications. Incidence and variety of neurological complications mostly depend on myelo- and immunosuppression severity and duration as well as on donor's and recipient's characteristics. The most frequent complications involving the nervous system include neurotoxic reactions, infections, autoimmune and lymphoproliferative diseases, and dysmetabolic conditions as well as cerebrovascular complications that potentially affect transplantation outcomes. Objective. To evaluate the impact of post-transplantation cerebrovascular events (CVEs) on transplantation outcomes in patients with hematologic malignancies. Materials and methods. We analyzed 899 transplantations performed at the Raisa Gorbacheva Memorial Research Institute for Pediatric Oncology, Hematology, and Transplantation, Pavlov First Saint Petersburg State Medical University, from 2016 to 2018. We assessed transplantation parameters and donor's and recipient's characteristics by intergroup comparison, pseudo-randomization (propensity score matching), KaplanMeier survival analysis, and log-rank tests. Results. Post-transplantatively, CVEs developed in 2.6% (n = 23) of cases: 13 (1.4%) ischemic strokes and 11 (1.2%) hemorrhagic strokes or intracranial hemorrhages were diagnosed. CVEs developed on days 99.5 39.2 post hematopoetic stem cell transplantation (HSCT). There were more patients with non-malignant conditions in the CVE group as compared to the non-CVE group (21.7% vs 7.9%; p = 0.017). Patients with CVE had a significantly lower Karnofsky index (75.6 21.3 vs 85.2 14.9; p = 0.008). Statistically, we also note some non-significant trends: patients with CVE more often underwent allogenic HSCT (82.6% vs 64.0%; p = 0.077) while donors were more often partially (rather than totally) HLA compatible for recipients (39.1% vs 21.1%; p = 0.33). Patients with CVE more often had a history of venous thromboses (13.3% vs 4.2%; p = 0.077). Post-HSCT stroke decreased post-transplantation longevity by approximately 3 times (331.8 81.6 vs 897.9 25.4 post HSCT; p = 0.0001). In the CVE group, survival during first 180 days post HSCT (landmarks post-HSCT Day+60 and Day+180) was significantly lower as compared to that in the CVE-free group. If CVE developed during first 30 days and 100 days post HSCT, vascular catastrophe did not affect post-HSCT survival significantly. Conclusion. Whereas ischemic stroke is a long-term HSCT complication (beyond D+100 post transplantation), hemorrhagic stroke is a short-term complication (D0D+100 post HSCT). CVEs affect survival in patients with hematologic malignancies, especially those developed between D+60 and D+180 post HSCT. History of venous abnormalities, low Karnofsky index at HSCT initiation, and the type of allogenic HSCT, especially from half-matched donors, can be considered as negative outcome risk factors in post-HSCT CVE

    НЕПОСРЕДСТВЕННЫЕ И ОТДАЛЕННЫЕ РЕЗУЛЬТАТЫ ЭНДОПРОТЕЗИРОВАНИЯ ПРИ РАССЛОЕНИЯХ И АТЕРОСКЛЕРОТИЧЕСКИХ АНЕВРИЗМАХ ГРУДНОЙ АОРТЫ

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    Objective: to analyze the results of endovascular stent-graftingin dissections and atherosclerotic aneurysms of descending part of thoracic aorta.Material and method: in this analysis includes 28 patients with dissections and atherosclerotic aneurysms of descending part of thoracic aorta. Acute aortic dissection type 3 was occurred in 10 patients and two of them were complicated with rupture into the left pleural cavity. 10 patients with chronic aortic dissection type bunderwent operations and one of them was complicated with rupture into the left pleural cavity. Among 8 operated patients due to chronic aneurysms of descending part of thoracic aorta, 4 patients were manifested with symptoms of hemothorax. In 3 patients with aortic dissection type 1 in long-term period, endovascular stent-grafting was performed concerning with the dilatation of descending thoracic aorta and patent false lumen. During in-hospital and long-term periods immediate clinical results, serious clinical complications and long-term survival were compared.Results: technical success of endovascular stent-grafting was achieved in 100 % of cases. In-hospital mortality was 4 (14,2 %) and 30-day mortality was 3 (10,7 %). Events of paraplegia, TIA (Transient Ischemic Attack), prosthetic infection were not found in our research. Two clinical occurrences of vascular approach site complication were found; one case of endoleak type 1 and stent-graft dislocation which required repeated endovascular stent-grafting and one case of endoleak type 2 which was performed subclaviancarotid bypass and ligation of left subclavian artery. Prolong intubation was needed in 5 patients (18,5 %).conclusion: Endovascular stent-grafting in dissections and atherosclerotic aneurysms of descending part of thoracic aorta contributes good immediate clinical results associating with less quantity of serious complications.ЦЕЛЬ ИССЛЕДОВАНИЯ: анализ результатов эндопротезирования (ЭП) при расслоениях и атеросклеротических аневризмах нисходящего отдела грудной аорты.МАТЕРИАЛЫ И МЕТОДЫ: в анализ были включены 28 пациентов с расслоениями и атеросклеротическими аневризмами нисходящего отдела грудной аорты. Острое расслоение 3 типа было у 10 пациентов, из них у 2 пациентов имелось осложнение в виде прорыва в левую плевральную полость. С хроническим расслоением В типа прооперировано 10 пациентов, из них у 1 – прорыв в левую плевральную полость. Из 8 пациентов, оперированных по поводу хронической атеросклеротической аневризмы нисходящего отдела грудной аорты, у 4 симптомы манифестировали в виде гемоторакса. У 3 пациентов с расслоением аорты 1 типа в отдаленном периоде выполнялось эндопротезирование в связи с дилатацией нисходящей рудной аорты и функционирующим ложным просветом. В госпитальном и отдаленном периодах сравнивались непосредственные клинические результаты, серьезные клинические осложнения и отдаленная выживаемость.РЕЗУЛЬТАТЫ. Технический успех ЭП был достигнут в 100 % случаев. Госпитальная летальность составила 4 (14,2 %), 30-дневная летальность – 3 (10,7 %). Случаев параплегии, ОНМК, инфекции эндографта в нашем исследовании не было. Наблюдалось два клинических случая развития осложнений в месте сосудистого доступа; один случай эндолика 1 типа и дислокация стент-графта, требующего повторного эндопротезирования, и один эндолик 2 типа, проведено подключично-сонное шунтирование, перевязка левой подключичной артерии. Продленная интубация потребовалась у 5 пациентов (18,5 %).ВЫВОДЫ: эндопротезирование при расслоениях и атеросклеротических аневризмах нисходящего отдела грудной аорты дает хороший непосредственный клинический результат, сопровождается меньшим количеством серьезных осложнений

    Global maps of soil temperature

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    Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world\u27s major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications
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