Platelet microparticles (PMPs) are small vesicles released from blood platelets upon activation. The procoagulant activity of PMPs has been previously mainly characterized by their ability to bind coagulation factors VIII and Va in reconstructed systems. It can be supposed that PMPs can contribute to the development of thrombotic complications in the pathologic states associated with the increase of their blood concentration. In this study, we compared procoagulant properties of calcium ionophore A23187-activated platelets and PMPs using several in-vitro models of hemostasis. Surface densities of phosphatidylserine, CD61, CD62P and factor X bound per surface area unit were determined by flow cytometry. They were 2.7-, 8.4-, 4.3-, and 13-fold higher for PMPs than for activated platelets, respectively. Spatial clot growth rate (V(clot)) in the reaction-diffusion experimental model and endogenous thrombin potential (ETP) were determined in plasma, which was depleted of phospholipid cell surfaces by ultra-centrifugation and supplemented with activated platelets or PMPs at different concentrations. Both V(clot) and ETP rapidly increased with the increase of PMP or platelet concentration until saturation was reached. The plateau values of V(clot) and ETP for activated platelets and PMPs were similar. In both assays, the procoagulant activity of one PMP was almost equal to that of one activated platelet despite at least two-orders-of-magnitude difference in their surface areas. This suggests that the PMP surface is approximately 50- to 100-fold more procoagulant than the surface of activated platelets.
A meridional Northern Hemisphere (NH) circulation epoch, which began in 1957, is marked by changes in the temperature and precipitation regimes over southwest Russia and central USA depending on the occurrence of NH atmospheric circulation regimes. A classification scheme proposed in 1968, and studied later put forth 13 NH circulation types, fitting more broadly into four groups, two of which are more zonal type flows and two of which are more meridional flows. Using the results of a previous study that showed four distinct sub-periods during the 1957–2017 epoch, the temperature and precipitation regimes of both regions were studied across all seasons in order to characterize modern day climate variability and their suitability for vegetation growth. Then the Hydrologic Coefficient, which combined the temperature and precipitation variables, was briefly studied. The most optimal conditions for vegetation growth, positive temperature and precipitation anomalies, were noted during the period 1970–1980 for southwest Russia, which was dominated by an increasingly more zonal flow regime in the Belgorod region and NH in general. For the central USA, the HTC showed more ideal conditions for agriculture in recent years due to favorable precipitation occurrence. In southwest Russia, variable precipitation regimes were noted during the meridional flow periods, and with the increase in temperature (since 1998), these can adversely affect the hydrothermal characteristics of the growing season. Finally, a comparison of the 13 NH circulation types with several teleconnection indexes demonstrated the robustness of the NH flow regime classification scheme used here.
The goal of this research is to evaluate changes in temperature and precipitation in the Central Chernozem Region of southwestern Russia during the summer and relate these to large-scale circulation types and synoptic circulation processes. Some of these circulation regimes result in extreme weather conditions over the region. Using a classification system for Northern Hemisphere large-scale flow regimes and observations of weather within the Central Chernozem Region, the role of individual synoptic patterns in the formation of weather anomalies was identified. Also, comparing the periods 1981–2010 and 1971–2000, the mean summer temperatures increased by 0.6°C regionally. During the most recent decade the increase was 1.3°C. Total precipitation for the summer increased over the 20th century and was characterized by less variability during the second half when compared to the first half. However, in the beginning of the 21st century, precipitation has decreased during the growing season, but variability has increased. The increase in summer temperatures and increased variability in precipitation were then linked to an increase in the occurrence of weather regimes associated with warm anomalies and blocking. Finally, the results of this study can be used to translate larger-scale seasonal or climate forecasts to the regional scale.
Геоинформационное и картограф ическое обеспечение экологических, экономических и социальных аспектов устойчивого развития территорий в условиях глобальных климатических изменений 209 the warmer time of the year-by 1.3 °С. However, it was frosty during January. This trend indicates an increased risk of higher fluctuations of the air temperature in the republic.
The ongoing climate change requires a quantitative assessment of the impact of weather conditions on the nature and livelihoods of the population. However, to date, the concept of “climate risk” has not been finally defined, and the corresponding terminology is not universally recognized. One manifestation of climate change is an increase in climate variability and extremeness in many regions. At the same time, modern statistics indicate growing worldwide damage from dangerous weather and climate events. The most widely used in climate services is the concept of “Vulnerability index”, which reflects a combination (with or without weighing) of several indicators that indicate the potential damage that climate change can cause to a particular sector of the economy. development of adaptation measures to ensure sustainable development of territories. The main criterion for the vulnerability of the territory from the point of view of meteorological parameters is the extremeness of the basic values: daily air temperature, daily precipitation, maximum wind speed. To fully take into account the possible impacts of extreme climatic conditions on the region’s economy, it is necessary to detail the weather and climate risks taking into account the entire observation network, since significant differences in quantitative assessment are possible. The obtained average regional values of the climate vulnerability indices for the Belgorod Region of the Russian Federation provide 150 points for the winter period, 330 points for the summer season, which indicates the prevalence of extreme weather conditions in the warm season. Most of the territory has a relative influence on climatic phenomena, with the exception of the East and the Southeast Region. Moreover, the eastern part of the region is the most vulnerable in climatic terms.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.