Pivotal Role of Reduced Glutathione in Oxygen-induced Regulation of the Na + /K + Pump in Mouse Erythrocyte Membranes

This study addresses the mechanisms of oxygen-induced regulation of ion transport pathways in mouse erythrocyte, specifically focusing on the role of cellular redox state and ATP levels. Mouse erythrocytes possess Na+/K+ pump, K+-Cl− and Na+-K+-2Cl− cotransporters that have been shown to be potential targets of oxygen. The activity of neither cotransporter changed in response to hypoxia-reoxygenation. In contrast, the Na+/K+ pump responded to hypoxic treatment with reversible inhibition. Hypoxia-induced inhibition was abolished in Na+-loaded cells, revealing no effect of O2 on the maximal operation rate of the pump. Notably, the inhibitory effect of hypoxia was not followed by changes in cellular ATP levels. Hypoxic exposure did, however, lead to a rapid increase in cellular glutathione (GSH) levels. Decreasing GSH to normoxic levels under hypoxic conditions abolished hypoxia-induced inhibition of the pump. Furthermore, GSH added to the incubation medium was able to mimic hypoxia-induced inhibition. Taken together these data suggest a pivotal role of intracellular GSH in oxygen-induced modulation of the Na+/K+ pump activit

Cluster observations of the midaltitude cusp under strong northward interplanetary magnetic field

We report on a multispacecraft cusp observation lasting more than 100 min. We determine the cusp boundary motion and reveal the effect on the cusp size of the interplanetary magnetic field (IMF) changing from southward to northward. The cusp shrinks at the beginning of the IMF rotation and it reexpands at the rate of 0.40° invariant latitude per hour under stable northward IMF. On the basis of plasma signatures inside the cusp, such as counterstreaming electrons with balanced fluxes, we propose that pulsed dual lobe reconnection operates during the time of interest. SC1 and SC4 observations suggest a long-term regular periodicity of the pulsed dual reconnection, which we estimate to be ~1–5 min. Further, the distances from the spacecraft to the reconnection site are estimated on the basis of observations from three satellites. The distance determined using SC1 and SC4 observations is ~15 RE and that determined from SC3 data is ~8 RE. The large-scale speed of the reconnection site sunward motion is ~16 km s-1. We observe also a fast motion of the reconnection site by SC1, which provides new information about the transitional phase after the IMF rotation. Finally, a statistical study of the dependency of plasma convection inside the cusp on the IMF clock angle is performed. The relationship between the cusp stagnation, the dual lobe reconnection process, and the IMF clock angle is discussed

Search for Low Mass Exotic mesonic structures. Part II: attempts to understand the experimental results

Our previous paper, part I of the same study, shows the different experimental spectra used to conclude on the genuine existence of narrow, weakly excited mesonic structures, having masses below and a little above the pion (M=139.56 MeV) mass. This work \cite{previous} was instigated by the observation, in the $\Sigma^{+}$ disintegration: $\Sigma^{+}\to$pP$^{0}$, P$^{0}\to\mu^{-}\mu^{+}$ \cite{park}, of a narrow range of dimuon masses. The authors conclude on the existence of a neutral intermediate state P$_{0}$, with a mass M=214.3 MeV $\pm$ 0.5 MeV. We present here some attempts to understand the possible nature of the structures observed in part I.Comment: 3 pages, 4 figures. Follows 0710.1796. Both replace arXiv:0707.1261 [nucl-ex

Is the Relation Between the Solar Wind Dynamic Pressure and the Magnetopause Standoff Distance so Straightforward?

We present results of global magnetohydrodynamic simulations which reconsider the relationship between the solar wind dynamic pressure (Pd) and magnetopause standoff distance (RSUB). We simulate the magnetospheric response to increases in the dynamic pressure by varying separately the solar wind density or velocity for northward and southward interplanetary magnetic field (IMF). We obtain different values of the power law indices N in the relation RSUB- ¼Pd- 1/N depending on which parameter, density, or velocity, has been varied and for which IMF orientation. The changes in the standoff distance are smaller (higher N) for a density increase for southward IMF and greater (smaller N) for a velocity increase. An enhancement of the solar wind velocity for a southward IMF increases the magnetopause reconnection rate and Region 1 current that move the magnetopause closer to the Earth than it appears in the case of density increase for the same dynamic pressure.Plain Language SummaryThe magnetopause is the boundary between the near- Earth space, which is governed by the magnetic field produced in the Earth’s core, and interplanetary space populated by the plasma emitted from the Sun called the solar wind. It is well known that the position of this boundary is defined by the balance of the pressures from both sides of the magnetopause and in a unique way depends on the velocity and density of the plasma in the interplanetary space. In this work, we reexamine the relationship between the magnetopause position and parameters of the solar wind by means of computer modeling. It is shown that the relationship between solar wind velocity and density and magnetopause position is more complex than originally thought. It is suggested that the pressure balance condition through the magnetopause depends on the continuing magnetic reconnection between the interplanetary and magnetospheric magnetic field lines and that the consequences of the reconnection change the relationship between the solar wind dynamic pressure and magnetopause boundary location.Key PointsWe reconsider the relation between the solar wind dynamic pressure and magnetopause standoff distanceThe magnetopause reacts differently to density, and velocity increases for the same dynamic pressureA new scaling law for magnetopause standoff distance is proposedPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154966/1/grl60461_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154966/2/grl60461.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154966/3/grl60461-sup-0001-Supporting_Information_SI-S01.pd

Statistical study of the location and size of the electron edge of the Low-Latitude Boundary Layer as observed by Cluster at mid-altitudes

The nature of particle precipitations at dayside mid-altitudes can be interpreted in terms of the evolution of reconnected field lines. Due to the difference between electron and ion parallel velocities, two distinct boundary layers should be observed at mid-altitudes between the boundary between open and closed field lines and the injections in the cusp proper. At lowest latitudes, the electron-dominated boundary layer, named the "electron edge" of the Low-Latitude Boundary Layer (LLBL), contains soft-magnetosheath electrons but only high-energy ions of plasma sheet origin. A second layer, the LLBL proper, is a mixture of both ions and electrons with characteristic magnetosheath energies. The Cluster spacecraft frequently observe these two boundary layers. We present an illustrative example of a Cluster mid-altitude cusp crossing with an extended electron edge of the LLBL. This electron edge contains 10–200 eV, low-density, isotropic electrons, presumably originating from the solar wind halo population. These are occasionally observed with bursts of parallel and/or anti-parallel-directed electron beams with higher fluxes, which are possibly accelerated near the magnetopause X-line. We then use 3 years of data from mid-altitude cusp crossings (327 events) to carry out a statistical study of the location and size of the electron edge of the LLBL. We find that the equatorward boundary of the LLBL electron edge is observed at 10:00–17:00 magnetic local time (MLT) and is located typically between 68° and 80° invariant latitude (ILAT). The location of the electron edge shows a weak, but significant, dependence on some of the external parameters (solar wind pressure, and IMF <i>B<sub>Z</sub></i>- component), in agreement with expectations from previous studies of the cusp location. The latitudinal extent of the electron edge has been estimated using new multi-spacecraft techniques. The Cluster tetrahedron crosses the electron and ion boundaries of the LLBL/cusp with time delays of 1–40 min between spacecraft. We reconstruct the motion of the electron boundary between observations by different spacecraft to improve the accuracy of the estimation of the boundary layer size. In our study, the LLBL electron edge is distinctly observed in 87% of mid-altitude LLBL/cusp crossings with clear electron and ion equatorward boundaries equivalent to 35% of all LLBL/cusp crossings by Cluster. The size of this region varied between 0°–2° ILAT with a median value of 0.2° ILAT. Generally, the size of the LLBL electron edge depends on the combination of many parameters. However, we find an anti-correlation between the size of this region and the strength of the IMF, the absolute values of the IMF <i>B<sub>Y</sub></i>- and <i>B<sub>Z</sub></i>-components and the solar wind dynamic pressure, as is expected from a simple reconnection model for the origin of this region

Моніторинг дерматологічної патології дрібних тварин в умовах ветеринарної клініки “Велес” (м. Миколаїв)

Dermatological diseases are a fairly common problem encountered in the practice of veterinarians worldwide. However, the types of clinical cases of dermatopathology and their prevalence may vary from region to region due to factors such as breed prevalence, genetics, environmental conditions and epizootic data, available methods of prevention and treatment, etc. This study aimed to monitor dermatological patients in Mykolaiv to determine their current prevalence and the possibility of reducing the trends of the most common dermatological problems in the future. The following objectives were set: to collect statistical data on cases of dermatological diseases among cats and dogs; to study the species, sex, breed, and age prevalence of diseases in animals owned by residents of Mykolaiv; to analyze the data obtained on the types of diseases, compare their prevalence and identify trends. The study's material was data from the register of sick animals at the Veles Veterinary Clinic (Mykolaiv), which were entered into tables and used for statistical analysis. During the study period (from 22.12.2023 to 19.01.2024), 41 dermatological patients were diagnosed, the majority of whom were cats (49 %) and dogs (46 %), with a predominance of male sex and age under 1 year. The most commonly diagnosed conditions were dermatomycosis (22 %), dermatitis (19.5 %), malassezia (9.8 %), eczema (9.8 %), pododermatitis (7.3 %) and eosinophilic granuloma (7.3 %). The systematic monitoring of dermatological pathologies of small animals in Mykolaiv will be carried out to control the epizootic situation in the city, possibly further reducing the incidence trends.Дерматологічні захворювання – досить поширена проблема, що спостерігається в практиці ветеринарних лікарів всього світу. Однак типи клінічних випадків дерматопатологій та їх розповсюдженість можуть відрізнятися залежно від регіону через такі фактори, як: породна поширеність тварин, генетика, екологічні умови та епізоотологічні дані, наявні методи профілактики і лікування тощо. Саме тому за мету даного дослідження було поставлено моніторинг дерматологічних пацієнтів у м. Миколаєві для визначення їх поширеності на теперішній час та можливості зменшення тенденцій найрозповсюдженіших проблем дерматології у майбутньому. Для вирішення поставленої мети було визначено такі завдання: збір статистичних даних про випадки дерматологічних захворювань серед котів та собак; вивчення видової, статевої, породної та вікової поширеності захворювань тварин, які перебувають у власності мешканців Миколаєва; аналіз отриманих даних щодо видів захворювань, порівняння їх поширеності та визначення тенденцій. Матеріалом для дослідження слугували дані реєстраційного журналу хворих тварин ветеринарної клініки “Велес” (м. Миколаїв), які було внесено у таблиці й на основі яких проведений статистичний аналіз. За період проведення дослідження (з 22.12.2023 по 19.01.2024) було діагностовано 41 дерматологічний пацієнт, серед яких основну частину становили коти (49 %) та собаки (46 %) із переважанням за статтю самців та за віком – до 1 року. У пацієнтів найчастіше діагностувались дерматомікози (22 %), дерматити (19,5 %), маласезіоз (9,8 %), екземи (9,8 %), пододерматит (7,3 %) та еозинофільна гранульома (7,3 %). Систематичний моніторинг дерматологічних патологій дрібних тварин в м. Миколаєві проводитиметься й надалі з метою контролю епізоотичної ситуації міста, з можливістю подальшого зменшення тенденцій захворюваностей

RED-CELL MEMBRANE PROTEINS AND DIAMETER-THICKNESS RATIO IN PATIENTS WITH ESSENTIAL ARTERIAL HYPERTENSION COMPLICATED AND NON-COMPLICATED WITH METABOLIC SYNDROME

Change in structural and functional properties of red cell membrane proteins in patients with the essential arterial hypertension (EAH) can promote development of significant dysfunction of these cells and can complicate the course of a system hypoxia in this category of patients. The aim of our research was to determine the interrelation between red cell sphericity and the level of proteins of their membrane in patients with EAH complicated and non-complicated with metabolic syndrome (MS). 51 male patients with EAH I and II (average age - 42 ± 1.5 years) were examined and divided into 2 groups: group 1 - 29 patients with EAH complicated with MS; group 2 - 22 patients with EAH non-complicated with MS. Protein spectrum was assessed by 10 red cell membrane proteins. Results. Patients with EAH complicated with MS had decrease in spectrin level and loss of correlations between the levels of red cell membrane proteins. Number of patients with diameter-thickness ratio < 3.4 (indicates the existence of cells prone to spherocytosis) in the group 1 was twice more than in the group 2 (29.4 % vs 13.7 %). Conclusion. We determined structural and functional disorders in interrelations of such membrane proteins as a-spektrin, ATP and GAPDH (in patients with EAH complicated with MS), and ATP, GAPDH and actin (in patients with EAH non-complicated with MS) which promote development of acquired spherocytosis and further impairments in microcirculation and gaseous metabolism in tissues

NITRILIUM DERIVATES OF NIDO-CARBORANE IN SYNTHESIS OF TRANSITIONAL METAL COMPLEXES

This work was supported by Russian Science Foundation, project № 21-73-10199

Localization of shadow poles by complex scaling

Through numerical examples we show that the complex scaling method is suited to explore the pole structure in multichannel scattering problems. All poles lying on the multisheeted Riemann energy surface, including shadow poles, can be revealed and the Riemann sheets on which they reside can be identified.Comment: 6 pages, Latex with Revtex, 3 figures (not included) available on reques

Extended magnetic reconnection across the dayside magnetopause

The extent of where magnetic reconnection (MR), the dominant process responsible for energy and plasma transport into the magnetosphere, operates across Earth’s dayside magnetopause has previously been only indirectly shown by observations. We report the first direct evidence of X-line structure resulting from the operation of MR at each of two widely separated locations along the tilted, subsolar line of maximum current on Earth’s magnetopause, confirming the operation of MR at two or more sites across the extended region where MR is expected to occur. The evidence results from in-situ observations of the associated ion and electron plasma distributions, present within each magnetic X-line structure, taken by two spacecraft passing through the active MR regions simultaneously