Lagrangian Formulation for Free Mixed-Symmetry Bosonic Gauge Fields in (A)dS(d)

Covariant Lagrangian formulation for free bosonic massless fields of arbitrary mixed-symmetry type in (A)dS(d) space-time is presented. The analysis is based on the frame-like formulation of higher-spin field dynamics [1] with higher-spin fields described as p-forms taking values in appropriate modules of the (A)dS(d). The problem of finding free field action is reduced to the analysis of an appropriate differential complex, with the derivation Q associated with the variation of the action. The constructed action exhibits additional gauge symmetries in the flat limit in agreement with the general structure of gauge symmetries for mixed-symmetry fields in Minkowski and (A)dS(d) spaces.Comment: 17 pages, v2: clarifications added, misprints corrected; v3: minor changes, typos correcte

Metabolic changes from liver regeneration after metastatic colorectal cancer surgery

Background. The pathological effect of the surgical ischemia-reperfusion technique is a cause for the development of liver damage and occurrence of acute liver failure during the postoperative period in cancer patients after major resection as well as after transplantation. Despite the urgency of the problem, most of the pathological processes that accompany the above-mentioned conditions are still only incompletely studied. Objective. To investigate the mechanisms of the damaging effects of stress reaction after liver resection, to evaluate the functional state of residual liver tissue and to find ways to influence the regeneration and apoptosis of the resected liver, which in the future would make the liver surgery safer. Methods. The results of treatment of 15 patients with colorectal cancer (mCRC) and liver metastases, who had undergone surgery in the period from December 2015 to November 2016 at the National Cancer Institute. Determination of the state of the detoxifying function of hepatocytes and the coupling of biological oxidation and phosphorylation in the mitochondria of hepatocytes were performed by electron paramagnetic resonance at the temperature of liquid nitrogen. Results. It has been found that the levels of the oxidized and low-spin forms of cytochrome P-450 in the catalytic cycle of the detoxification system were 0.33 ± 0.08 relative units and 1.11 ± 0.13 relative units, respectively (the normal levels are 0.59 ± 0.03 relative units and 2.56 ± 0.02 relative units). Also, an increase registered in the levels of formation of complexes of NO-FeS-proteins up to the values of 0.33 ± 0.08 relative units (the normal level is 0.14 ± 0.07). We believe that such changes are the cause of disturbances in the energy function of mitochondria and the formation of cell hypoxia, which correlates with an increase of lactate levels in tissue of the future liver remnant. The liver remnant levels are > 2.00 mM/g·tissue, while the normal is 1.80 ± 0.26 mm/g·tissue. This confirms the functioning of hepatocytes under hypoxic conditions. Conclusions. In the residual liver tissue, we have found a decrease in detoxification system deficiency and the energy supply of hepatocytes. In hepatocytes of the future liver remnant, reprogramming of the metabolism of mitochondria from oxidative phosphorylation in glycolysis is registered, resulting in the formation of cell hypoxia and an increase in levels of lactate and superoxide radicals. To assess the degree of ALF in the postoperative period, we suggest use of the levels of lactate, the activity of cytochrome P-450, the levels of formation of complexes of NO and FeS-proteins in mitochondria ETC and the generation rate of SR as the markers

Metabolic changes from liver regeneration after metastatic colorectal cancer surgery

Background. The pathological effect of the surgical ischemia-reperfusion technique is a cause for the development of liver damage and occurrence of acute liver failure during the postoperative period in cancer patients after major resection as well as after transplantation. Despite the urgency of the problem, most of the pathological processes that accompany the above-mentioned conditions are still only incompletely studied. Objective. To investigate the mechanisms of the damaging effects of stress reaction after liver resection, to evaluate the functional state of residual liver tissue and to find ways to influence the regeneration and apoptosis of the resected liver, which in the future would make the liver surgery safer. Methods. The results of treatment of 15 patients with colorectal cancer (mCRC) and liver metastases, who had undergone surgery in the period from December 2015 to November 2016 at the National Cancer Institute. Determination of the state of the detoxifying function of hepatocytes and the coupling of biological oxidation and phosphorylation in the mitochondria of hepatocytes were performed by electron paramagnetic resonance at the temperature of liquid nitrogen. Results. It has been found that the levels of the oxidized and low-spin forms of cytochrome P-450 in the catalytic cycle of the detoxification system were 0.33 ± 0.08 relative units and 1.11 ± 0.13 relative units, respectively (the normal levels are 0.59 ± 0.03 relative units and 2.56 ± 0.02 relative units). Also, an increase registered in the levels of formation of complexes of NO-FeS-proteins up to the values of 0.33 ± 0.08 relative units (the normal level is 0.14 ± 0.07). We believe that such changes are the cause of disturbances in the energy function of mitochondria and the formation of cell hypoxia, which correlates with an increase of lactate levels in tissue of the future liver remnant. The liver remnant levels are > 2.00 mM/g·tissue, while the normal is 1.80 ± 0.26 mm/g·tissue. This confirms the functioning of hepatocytes under hypoxic conditions. Conclusions. In the residual liver tissue, we have found a decrease in detoxification system deficiency and the energy supply of hepatocytes. In hepatocytes of the future liver remnant, reprogramming of the metabolism of mitochondria from oxidative phosphorylation in glycolysis is registered, resulting in the formation of cell hypoxia and an increase in levels of lactate and superoxide radicals. To assess the degree of ALF in the postoperative period, we suggest use of the levels of lactate, the activity of cytochrome P-450, the levels of formation of complexes of NO and FeS-proteins in mitochondria ETC and the generation rate of SR as the markers

Connection between the Earth’s Climate Change and Variations in the Geomagnetic Field and Cosmic Ray Fluxes during the Past Ten Thousands of Years

Peer reviewe

Mechanism of filopodia initiation by reorganization of a dendritic network

Afilopodium protrudes by elongation of bundled actin filaments in its core. However, the mechanism of filopodia initiation remains unknown. Using live-cell imaging with GFP-tagged proteins and correlative electron microscopy, we performed a kinetic-structural analysis of filopodial initiation in B16F1 melanoma cells. Filopodial bundles arose not by a specific nucleation event, but by reorganization of the lamellipodial dendritic network analogous to fusion of established filopodia but occurring at the level of individual filaments. Subsets of independently nucleated lamellipodial filaments elongated and gradually associated with each other at their barbed ends, leading to formation of cone-shaped structures that we term Λ-precursors. An early marker of initiation was the gradual coalescence of GFP-vasodilator-stimulated phosphoprotein (GFP-VASP) fluorescence at the leading edge into discrete foci. The GFP-VASP foci were associated with Λ-precursors, whereas Arp2/3 was not. Subsequent recruitment of fascin to the clustered barbed ends of Λ-precursors initiated filament bundling and completed formation of the nascent filopodium. We propose a convergent elongation model of filopodia initiation, stipulating that filaments within the lamellipodial dendritic network acquire privileged status by binding a set of molecules (including VASP) to their barbed ends, which protect them from capping and mediate association of barbed ends with each other

The Mio-Pliocene transition in the Dacian Basin (Eastern Paratethys): Paleomagnetism, mollusks, microfauna and sedimentary facies of the Pontian regional stage

Well-documented, high-resolution sedimentary sections are critical to our understanding of the often eventful evolution of semi-isolated basins that form during the final stages of continent–continent convergence, as exemplified by the Mediterranean-Paratethys system. Due to its nearly land-locked position in the Late Miocene, the Mediterranean experienced the renowned Messinian Salinity Crisis. At the same time, the equally restricted Eastern Paratethys to the north-east evolved in a potentially related, but very distinctive way. The events of this period are fully recorded in the sediments deposited during the Pontian regional stage in the Dacian Basin, part of the Eastern Paratethys, which we here investigate in detail in the best available section. The studied interval of the Slănicul de Buzău section is more than 2 km thick and almost continuously exposed. It is analyzed for paleomagnetism, mollusks, microfauna and sedimentary facies. This allows us to refine previous results from nearby but less complete sections, with particular improvements concerning resolution, biostratigraphy and sedimentology. The marine incursion just below the base of the Pontian (6.1 Ma) is shown to significantly predate the early Pontian highstand. The biostratigraphically defined onset of the middle Pontian (6.0 Ma) coincides with the highstand and slightly predates the major regression (5.9–5.6 Ma) for which the middle Pontian is best known. In the here-investigated section, the transgression at the beginning of the late Pontian (5.6 Ma) is followed by a regressive trend culminating between 5.4 and 5.2 Ma around the Mio-Pliocene boundary (5.33 Ma). The late Pontian sedimentation then becomes relatively stable and the fauna gradually transitions (4.8 Ma) into assemblages characteristic for the Dacian stage of the Dacian Basin, while overall significantly diverging from the rest of the Eastern Paratethys. Finally, we discuss several factors that could affect accuracy and applicability of the updated chronostratigraphy, warranting some caution

Стробирование радиолокационных отметок при траекторной фильтрации в связанных координатах

Introduction. Modern air targets, particularly drones, are becoming less noticeable, while their manoeuvrability continues to improve. Trajectory processing algorithms have also been improved in order to provide for effective tracking of highly manoeuvring targets. The accuracy of filtering trajectory parameters is largely determined by the reliability of radar information. This has also required an enhanced role for strobe algorithms and the need to increase the effectiveness of strobe radar marks.Aim. To develop and investigate the efficiency of a trajectory strobe algorithm based on the target motion model in a high-speed coordinate system associated with the direction of the target motion and involving the formation of a strobe in the form of a truncated elliptical sector.Materials and methods. The study considered the target motion model in the body-fixed frame. This model was taken as the basis for new trajectory filtering algorithms based on Kalman filtering. Existing methods for strobing radar marks of the target were considered and a new approach based on filtering in the body-fixed frame proposed. The new algorithm assumes the formation of a strobe in the form of a truncated elliptical sector. This form corresponds to the most probable location of the marks of the tracked target. The effectiveness of the proposed solutions is confirmed by the results of mathematical modelling carried out using MATLAB.Results. The study produced analytical expressions for the motion model, recurrent filtering and strobe algorithm in the body-fixed frame. A comparative analysis of tracking effectiveness with the same volumes of the elliptical and proposed strobes was performed. It was established that the algorithm with strobe formation in the shape of a truncated elliptical sector provides for longer target tracking up to the time of the first loss of the mark for speed and highly manoeuvring targets, when compared to the elliptical strobe algorithm. In addition, the average duration of sector strobe tracking does not in practice depend on the initial speed of the target and provides greater accuracy for small measurement error values (less than 50 m) of the coordinates than in comparison with the elliptical one. Conclusion. The described results were achieved by the ability of the strobe in the body-fixed frame to adapt to the direction of motion and target manoeuvring, allowing high-quality target tracking within a larger speed range. Such strobe formation will also reduce the likelihood of skip-ping radar marks from the tracked target and will reduce the number of false marks belonging to other trajectories inside the strobe.Введение. Современные воздушные цели, в особенности беспилотные, становятся менее заметными, а их маневренные возможности продолжают совершенствоваться. Для обеспечения эффективного сопровождения высокоманевренных целей актуализируются и алгоритмы траекторной обработки. Поскольку точность фильтрации траекторных параметров во многом определяется достоверностью радиолокационной информации, возрастает роль алгоритмов стробирования. В связи с этим возникает задача повышения эффективности стробирования радиолокационных отметок.Цель работы. Разработка и исследование эффективности алгоритма траекторного стробирования, основанного на модели движения в скоростной связанной с направлением движения цели системе координат и предполагающего формирование строба в форме усеченного эллипсоидного сектора.Методы и материалы. Рассмотрены модели движения целей в связанных координатах, которые положены в основу новых алгоритмов траекторного сопровождения, базирующихся на калмановской фильтрации. Рассмотрены существующие методы стробирования радиолокационных отметок от цели и предложен новый подход на основе фильтрации в связанных координатах. Новый алгоритм предполагает формирование строба в форме усеченного эллипсоидного сектора. Такая форма соответствует наиболее вероятному местоположению отметок от сопровождаемой цели. Эффективность предложенных решений подтверждается результатами математического моделирования, выполненного в среде MATLAB.Результаты. Приведены аналитические выражения для модели движения, рекуррентной фильтрации и алгоритма стробирования в связанных координатах. Проведен сравнительный анализ эффективности сопровождения при одинаковых размерах эллиптического и предложенного стробов. Установлено, что для скоростных и высокоманевренных целей алгоритм с построением строба в форме усеченного эллипсоидного сектора обеспечивает до 30 % более длительное сопровождение до первой потери отметки от цели, чем алгоритм с эллиптическим стробированием. Кроме того, средняя продолжительность сопровождения для секторного строба практически не зависит от начальной скорости движения цели, а при значениях погрешностей измерения координат менее 50 м имеет большее значение, чем для эллиптического.Заключение. Достигнутый результат обеспечивается способностью строба в связанных координатах подстраиваться под направление движения и маневрирование цели, что позволяет осуществлять качественное сопровождение объектов в большем диапазоне скоростей. Построение такого строба также позволит снизить вероятность пропуска радиолокационных отметок от сопровождаемой цели и обеспечит уменьшение числа ложных отметок и отметок, принадлежащих другим траекториям, внутри строба