Favorable Background Research Articles

Post-COVID Myocarditis in Patients with Primary Cardiomyopathies: Diagnosis, Clinical Course and Outcomes.

The aim of this study was to evaluate the clinical course and outcomes of post-COVID myocarditis in patients with cardiomyopathies (CMP). This case series includes 10 patients with different CMPs who had COVID-19 (seven men; 48.4 ± 11.4 yr.): left ventricular non-compaction (n = 2), arrhythmogenic right ventricular CMP in combination with a heterozygous form of hemochromatosis (n = 1, HFE), restrictive CMP (n = 1, MyBPC3), laminopathy (n = 1, LMNA), dilated cardiomyopathy (n = 1, MYH7 + MyBPC3), Danon's disease (n = 1, LAMP2) and AL cardiac amyloidosis (n = 3). Myocardial morphological examination with immunohistochemical staining and PCR for SARS-CoV-2 and cardiotropic viruses was performed in six patients, while cardiac MRI and anti-cardiac antibody titres were evaluated in all patients. Post-COVID lymphocytic myocarditis was confirmed morphologically in six patients (with LVNC, RCM, ARCV, Danon's disease, and AL amyloidosis). Spike and nucleocapsid coronavirus proteins were detected in cell infiltrates, endothelium and cardiomyocytes in all biopsies; SARS-CoV-2 RNA was found in five out of six. In four patients, the diagnosis of myocarditis was based on MRI, high titres of anti-cardiac antibodies and clinical data. The mean time from COVID-19 to the diagnosis of myocarditis was 7 (5; 10.5) months. Myocarditis manifested with the onset/increase of arrhythmias and heart failure. Immunosuppressive therapy with corticosteroids was administered to six patients and led to an increase in ejection fraction and improvement of heart failure symptoms in five of them. CMPs are a favourable background for the development of post-COVID myocarditis. The onset or deterioration of heart failure and/or arrhythmias in patients with CMPs after COVID-19 requires the exclusion of myocarditis and, if present, the administration of immunosuppressive therapy.

Interannual Fluctuations and Their Low-Frequency Modulation of Summertime Heavy Daily Rainfall Potential in Western Japan

Heavy rainfall under the conditions of the changing climate has recently garnered considerable attention. The statistics on heavy daily rainfall offer vital information for assessing present and future extreme events and for clarifying the impacts of global climate variability and change, working to form a favorable background. By analyzing a set of large-ensemble simulations using a global atmospheric model, this study demonstrated that two different physical processes in global climate variability control the interannual fluctuations in the 99th- and 90th-percentile values of summertime daily rainfall (i.e., the potential amounts) on Kyushu Island in western Japan. The 90th-percentile values were closely related to large-scale horizontal moisture transport anomalies due to changes in the subtropical high in the northwestern Pacific, which was usually accompanied by basin-scale warming in the Indian Ocean subsequent to the wintertime El Niño events. The contributions of the sea surface temperatures over the northern Indian Ocean and the eastern tropical Pacific Ocean showed low-frequency modulations, mainly due to the influences of the global warming tendency and the interdecadal variability in the climate system, respectively. In contrast, tropical cyclone activity played a major role in changing the 99th-percentile value. The potentials of both the tropical cyclone intensity and the existence density fluctuated, largely owing to the summertime sea surface temperature over the tropical Pacific, which can be modulated by the El Niño diversity on interdecadal timescales.

VALUE OF BONE REMODELLING MARKERS IN MANDIBULAR FRACTURE PATIENTS BY GENDER AND BONE MINERAL DENSITY

Numerous studies have shown that fractures of the mandible are the most common injuries of the facial skeleton. The high incidence of such fractures is due to the anatomical and physiological characteristics of the mandible, as well as a variety of local and general causes. Disturbances in the structural-functional properties of bone tissue can occur as a result of internal and external influences and provide a favorable background for the development of fractures in various locations, including the mandible. A large number of regulatory factors of a nervous, humoral and immune nature, the presence of inflammation as an obligatory (first) phase of reparative regeneration after bone damage, dictate the need for an in-depth study of the structuralfunctional state of bone tissue in patients with traumatic injuries of the mandible, through the improvement of diagnostic and therapeutic methods. The aim of the study is to analyze the levels of bone remodeling markers in the oral fluid of patients with traumatic lesions of the mandible according to sex and BMD status compared with those of practically healthy control subjects (without general somatic and dental diseases). Materials and methods. The study is based on the results of laboratory tests on 151 people (main group) with mandibular fractures and 30 people (control group) without general somatic and dental diseases. The study included patients of both sexes aged 18-44 years: 92 (60,93%) male and 59 (39,07%) female patients. The levels of total calcium (Ca) and inorganic phosphorus (P) in the oral fluid were determined by photometric methods using commercial kits from «Filisit-Diagnostics» (Ukraine). The activity of alkaline phosphatase and acid phosphatase in oral fluid was determined by the kinetic method with n-nitrophenol phosphate. Oxyproline excretion was determined in daily urine using the Cobas test system (Roshe Diagnostics, Germany). Statistical processing of the study results was performed using Microsoft Excel and Statistics software packages for the statistical analysis of biomedical research data. Results and discussion. As a result of the studies, it was found that in men with osteoporosis, the levels of P in oral fluid were not significantly different from those in the control group, p>0,05. At the same time, the remaining values of bone remodeling markers in biological fluids were characterized by a pronounced imbalance, namely an increase in Ca content by 92,85%, p<0,01, p1<0,05, Ca/P ratio by 2,8 times, p, p1<0,01, AP activity by 89,48%, p<0,01, p1>0,05, ALP by 56,34%, p<0,05, p1>0,05, and urinary hydroxyproline level by 54,09%, p, p1<0,01, compared with the same data in the control group. In women with osteoporotic mandibular fractures, the values of all the parameters studied were significantly different from those of the control group. Thus, we found an increase in the oral fluid content of Ca – by 102,38%, p, p1<0,05, Ca/P ratio – by 3,5 times, p, p1<0,01, AP activity – by 99,06%, p, p1<0,01, ALP – by 65,15%, p, p1<0,01 against a decrease in the value of P – by 42,31%, p, p1<0,05, compared to the data of the control group. At the same time, in this subgroup of women there was an increase in urinary hydroxyproline by 58,26%, p, p1<0,01, compared to the data in the control group. Conclusions. Thus, analysis of bone remodeling marker levels showed that in patients with mandibular fractures due to destruction of the bone matrix as a result of trauma, there was an increase in osteoresorption activity that depended on the structural-functional state of the patients' bone tissue and was more pronounced in women.

The perception of Ukrainians about political life in the post-war period and the prospects for the spread of populism

The non-acceptance by the majority of the population of Ukraine of the idea of elections during a full-scale war is a forced prolongation of the legitimacy of existing state institutions. Ukrainians understand all the risks of such elections for the political system under martial law, agreeing to the norms of legislation and compliance with democratic procedures. At the same time, a sufficiently significant number of the population is forming, which does not share the monopolization of power during the war by one political force. Accumulation of political issues, which will be expressed in the post-war period, will become a significant challenge for the political class of Ukraine. The low level of trust in existing political parties and the growing demand for new political forces can become a favorable background for the spread of anti-elitist ideas of populism. In public opinion, there is a demand mostly for politicians from the military environment and to a lesser extent from expert and civil sectors, intelligentsia, and volunteers. Reconstruction of the post-war economy will require non-standard solutions, in particular, optimization of expenditures in the social sphere and maximum liberalization. Several innovations will not have support in the mass consciousness. In particular, Ukrainians are mostly in favor of free medicine and education, a ban on the sale of land to foreigners, and assigning responsibility for increasing people’s incomes to the state, not to the individual. The lack of financial resources after the end of the war can accelerate the growing social deprivation. The combination of these potentially conflicting attitudes with a high level of antagonism and intolerance to a different political point of view can be skilfully «warmed up» by populist forces.

Comparisons between Short- and Long-Lived Cross-Equatorial Flow Events over the Maritime Continent: Perspective from the Intraseasonal Oscillation

Abstract The duration of cross-equatorial flow (CEF) events over the Maritime Continent (MC) varies greatly, from 3 days to more than 1 month. In this study, we classify CEF events into short- and long-lived ones using a threshold of 7 days, and conduct separate investigations on their statistical and evolution characteristics, as well as the associated physical processes from the perspective of two dominant modes of the intraseasonal oscillation. Results indicate that short-lived events, characterized by westward-propagation southerly anomalies, are largely dependent on the 10–25-day oscillation, while the contribution of the 30–60-day component is negligible. The associated enhanced convection is primarily confined to the western North Pacific (WNP) and moves northwestward, accompanied by an anomalous cyclone. In contrast, long-lived events show consistent changes among different CEF branches, characterized by southerly anomalies dominating the MC, which benefit from the favorable background of the 30–60-day oscillation. Associated convection anomalies show a dipole pattern, with enhanced convection over WNP and suppressed convection over the Indian Ocean. The enhanced WNP convection gradually migrates northward, inducing CEF anomalies via a continuous anomalous cyclone, while the suppressed convection can be found to slightly expand to the MC. Meanwhile, the 10–25-day oscillation shows similar magnitude and evolution with that in short-lived events, but is no longer crucial to the establishment of long-lived events.

A Case Study on the Rainstorm‐Producing Mesoscale Vortices in Central‐Eastern China

AbstractDuring 26–27 June 2022, mainly influenced by three mesoscale vortices, central‐eastern China (particularly for Henan and Shandong) experiences the first widespread torrential rainfall event of the 2022 flood season (maximum 24‐hr accumulated precipitation is ∼380.9 mm), resulting in severe social impacts. The three mesoscale vortices form and sustain under favorable background conditions, mainly including a strong upper‐level divergence, an intense middle‐level warm advection, and a powerful lower‐level convergence associated with a low‐level jet. Among the vortices, the vortex which forms over Shandong, lasts for ∼9 hr, and makes a much larger contribution than the other vortices to the accumulated precipitation, is defined as the primary vortex. More than a half of the hourly precipitation peaks in this event appear in the life span of the primary vortex, which is closely related to the variations of the vortex in its cyclonic‐vorticity and vertical extent. Backward trajectory analysis indicates that air particles originating from the lower troposphere southwest of the primary vortex contribute the most to its formation (∼82.7%). These air particles mainly experience a notable increase in their cyclonic‐vorticity due to convergence‐related vertical stretching, which directly renders the formation of primary vortex. During the whole life span of the primary vortex, convergence‐related vertical stretching is the most favorable factor for its development/sustainment, and the convection‐related vertical transport of cyclonic vorticity ranks second; whereas, the horizontal transport is the most detrimental factor. Moisture budget shows that Southeast China is the most important moisture source for this event (accounting for ∼48.9%).

Mechanisms Accounting for the Formation of the Strong Winds that Caused the Tripping Incident of Transmission Line in Eastern Inner Mongolia

Meteorological disasters pose a serious threat to the State Grid Corporation of China, which covers ~ 88% of Chinese national territory. Of these, strong winds deserve a special attention, as they often induce windage yaw discharge of transmission lines and even toppling of transmission towers, resulting in serious economic losses. On 28 June 2023, a severe tripping incident of transmission line appears in Eastern Inner Mongolia due to strong winds. In this study, we conduct comprehensive analyses to clarify the favorable background conditions and governing mechanisms for producing the strong winds. Main results are shown as follows. Synoptic analysis indicates that, the favorable background environments for the event are characterized by a strong upper-level jet associated upper tropospheric divergence; an intense middle-level warm advection ahead of a shortwave trough; and a long-lived lower-tropospheric mesoscale vortex. The strong winds that cause the tripping incident mainly occur in the southeastern quadrant of the vortex. Vorticity budget presents that the period from the mesoscale-vortex’s formation to 4 h before is crucial to the mesoscale vortex, as cyclonic vorticity increases rapidly mainly due to the lower-level convergence-related vertical stretching. In contrast, the horizontal transport mainly results in a net export of cyclonic vorticity, which is the most detrimental factor. Kinetic energy (KE) budget shows that, after the mesoscale vortex forms, the strong winds within its southeastern quadrant enhance rapidly. Overall, the positive work done by the pressure gradient force associated with the mesoscale vortex dominates the enhancement of strong winds; the horizontal transport of KE is the second dominant factor, and the vertical transport of KE (i.e., the downward momentum transportation) shows the least contribution.

Main peculiarities in the process of integration and social inclusion of refugees and/or forcibly displaced persons of various quintiles

The process of integration and social inclusion of representatives of various socio-economical quintiles has always been a controversial issue. Since the moment of massive influx of representatives of the “rich quintile” in the last decade, scientists alongside with the local community were tended to think that the financial prosperity and unordinary assets, properties, skills and knowledge, which make more difficult the process of a proper “distinguishing” refugees and/or forcibly displaced persons (it means, make them unrecognized as ones, who are in need of actual help) lead to disruption of supportive relationships between newcomers and accepting community. However, the practice of cooperation between people seeking for a refugee from one side and accepting community of global society, in particular, EU one from another one, shows that people coming from less favorable backgrounds and possessing less favorable starting points can also be discriminated and underestimated on their way to the wellbeing in a receiving community. In the following article we are presenting tools and methods of obtaining a necessary level of long lasting appropriate and sustainable societal development by enabling a proper level of integration and social inclusion of all quintiles of refugees/forcibly displaced persons by recognizing their current and/or future potential.

Frequency and causes of blood chimera in combat trauma victims

The frequency and causes of blood chimeras in victims of combat trauma who arrived from special military operations were analyzed. Data from immunohematological studies of patients admitted to the clinics of the Military Medical Academy named after S. M. Kirov in the period from February to December 2022 were analyzed. All patients were assessed for blood group membership by AV0 systems and Rh factor with phenotyping of erythrocytes and the presence of antierythrocyte antibodies. Chimerism was found in 21% of the patients. According to the AB0 system, general chimerism was detected in 3. 1% of cases, whereas blood chimerisms for antigens A and B were found in 81. 8% and 36. 4% of the cases, respectively. Moreover, blood chimerism for antigens C, c, E, and e was detected in 100% of the cases, and for antigen D, the rate of chimerism was 7. 6%. The identified chimerism in the patients was caused by the use of “universal” doses of erythrocyte blood components by advanced medical service units. In general, the frequency of blood chimerism in victims of combat trauma in the clinics of the Military Medical Academy named after S. M. Kirov was 21%. Blood chimerism in combat trauma victims did not lead to significant immunization. Despite the absence of detected immunization, blood chimerism was a favorable background for possible hemolytic posttransfusion complications during treatment. Possible options for the prevention of blood chimerism include the introduction into practice of advanced use of artificial oxygen carriers, active use of hardware support for reinfusion of blood spilled into the cavity, and preparation of autokrovi for certain patients. These measures are aimed at reducing the number of transfusions of donor blood components, thereby preventing the formation of antierythrocyte antibodies and blood chimeras.

The Phygitalization of Moderne Languages Teaching in the Aftermath of COVID-19

Against numerous, more or less favourable backgrounds, education is among the many fields of activity always changing for progress, as it is designed so as to meet the needs of society. For some decades now, and even more to come, the main trigger for change has been technology. Being acknowledged for its immediate benefits, such as effort and time saving or enjoying the convenience of accessing wide-open resources, digital technology has considerably influenced all interested stakeholders’ perspective on education. This article aims to present the role that digital technology tools play, not only in addressing the teaching challenges inherent in the aftermath of the COVID-19, but also in engaging and empowering students attending the English for Economics and Business Communication seminar at the Bucharest University of Economic Studies (ASE Bucharest). Many of the approaches used in what was called hybrid, blended, asynchronous or semi-synchronous teaching and learning currently prove to be useful tools in bridging the digital world with the physical one, with the purpose of driving engagement, avoiding info dumping, diversifying assessment means, all in all providing interactive experiences for both teachers and learners.

ANTISOCIAL PERSONALITY DISORDER IN CHILDREN WHO WERE BORN IN INTERNATIONAL FAMILIES

Introduction. The postulate of integration and social inclusion of people possessing somehow migrational backgrounds remains a fundamental issue for our nowadays society. On one hand, there is a totally favorable background to create multiculturalism and diversity in the particularly European community. On the other hand, once we analyze individual situations, especially ones, which take place in the international families, we will predominantly see a completely opposite tendency i.e. to maximally assimilate the way their child will be raised and educated. Thus, these are exactly parents possessing migrational backgrounds, who do want to “limit” their child from being “international” by claiming that this attitude will help them to protect a necessary identity for future integration and social inclusion. In the reality, however, the tendency of international families to raise/educate monocultural children may lead to disruption of social, societal, economical and educational wellbeing of the offsprings, as well as will rather than not lead to development of the antisocial personality disorder. Materials and methods. Naturalistic observation, case studies, survey/self-report data, analysis, synthesis, induction, deduction. In the frame of our cooperation and voluntary activity at the DAR for peace and equality (non-formal international group, based in Milan, Italy), we have analyzed the results of anonymous survey, which was led by us within the group of 73 people, from 18 to 43 years old, who are representatives of generation of locals “with migrational background” (the third migrational generation). The main characteristic feature of this social group is that they were born in so-called “international families” i.e. families, where one of the parents possesses either direct or indirect migrational background. Primarily, to assess the probability of declining of the appropriate (“desirable”) level of integration and social inclusion in the aforementioned individuals, we have assessed the gender and age balance between analyzed persons. Thus, there were 73 people, namely: 41 women and 32 men with the age range from 18 to 43 years old. The average age of persons in the group reached the index of 30,1 years old. Digital data were processed by using the method of variation statistic with calculating of the arithmetic mean (M), standard deviation (δ), the average error difference (m), the difference probability (p). The last data between two average in small samples was determined according to the Student’s table in compliance of condition (n1+n2-2). In determining of the probability level it was admitted an accuracy of p<0.05. Results. As a result, we have assessed a probability of development of the antisocial personality disorder in this social group, as well as possible reasons for the development of the analyzed condition. The probability of the APD development in the analyzed social group is tightly connected with the way these people (former children, who were born in international families) were grown and educated. Especially, if the multicultural families are forcibly rendered “monocultural” because of the “desire” of one of the parents, or mutual one. Neither of the expected scenarios of “assimilation” appear to be successful to make the process of the child’s integration and social inclusion appropriate, adequate and positive. In over 90% of cases, children who were forcibly rendered “monocultural” despite having international family, experience APD of various types, severe depression, tendency to migrational nomadism and migrational vacuum. Their condition may be however relieved through healing amnesia phenomenon, as it was numerously postulated in our former article within the framework research. Discussion. The tendency to forcibly render multicultural families monocultural is tightly connected with dominating prejudices, biases, fears, expectations and stereotypes regarding the community of migrants, refugees and forcibly displaced persons. They are socially “supposed to be different”, The difference may noticeably aggravate every pattern of their existence. Thus, the parents of such children are tended to refuse to “share their migrational background” with their child and try to make him/her “assimilate” from the very young age. However, it is exactly the forcible assimilation, which may lead to development of the antisocial personality disorder, migrational nomadism and migrational vacuum in case of the representatives of the third generation. Thus, the postulates of “desirable” diversity and multiculturalism, which are accepted and tolerated not exclusively within the legal framework, but also in societal realities will definitely lead to optimizing the general pattern of integration and social inclusion of persons, who possess migrational background; will decrease the index of probability of APD development in the similar cases, as well as will eliminate a typical tendency to “waste human potential” regarding “newcomers”.

Русско-турецкие официальные контакты в Приазовье летом 1699 г. (к предыстории миссии чрезвычайного посланника Е.И. Украинцева)

The article examines official contacts between the Russian Tsardom and the Ottoman Empire in the Sea of Azov Region during the preparation of the embassy of Y.I. Ukraintsev to Constantinople in 1699. The parties were represented by officials who did not have diplomatic status: Admiral F.A. Golovin, who arrived in Azov and the Beylerbey of Kefe Tatar Murtaza Pasha, who was in Kerch. The Azov Palatine (Governor) participated in organizing communication between them, within the framework of the so-called border diplomacy. The Armistice of Karlowitz established in 1699 and the mutual hope for concluding a long-term peace served as a favorable background for the development of bilateral relations at the local level. It is shown that, largely thanks to successfully conducted negotiations, including through envoys and correspondence, the admiral and the beylerbey managed to organize a temporary stay in the Kerch Strait for a squadron of the Azov Fleet and the dispatch of a Tsar’s Envoy to Constantinople on a Russian warship. The source base for the study consisted mainly of archival documents, some of which were introduced into scientific circulation for the first time.

MORPHOLOGICAL CHARACTERS VARIABILITY OF THE A4-10 WINTER WHEAT LINE UNDER CURRENT CLIMATE CONDITIONS

Currently, wheat plants know permanent evolutions of productive potential, of quality and of different resistances. The morphology of the plant in general, as well as the production elements: ears, grains and mass of a thousand grains, know true performances. The expression of the morphological characters of the plants is, however, closely related to the natural provision of water. Being a plant that capitalizes on moisture, frequently encounters periods of deficit, especially during the period of depositing dry matter in the grains. The intensity of these drought periods causes some decreases in the expression of plant and grain morphology respectively. In the present research, the appearance of the plants is compared together with the production elements obtained in three different years, namely one with a favorable background and two dry years. From the obtained data, the plants of line A.4-10 affected by drought had a smaller height by 3-7 cm and stem thicknesses reduced by 0.15 mm. The length of the ear was shorter by 1.5 cm, the number of grains in an ear was 18 less, and the mass of the grains was also reduced by 0.9 g. The mass of a thousand grains decreased by about 3 g. Correlations between characters were positive and statistically well supported. Straw length was negatively correlated with the other characters, possibly due to the reduced waist obtained in its breeding.

Triple-dip La Niña in 2020–23: understanding the role of the annual cycle in tropical Pacific SST

The triple-dip La Niña in 2020–23 is characterized by persisting southeasterly wind anomalies over the tropical central and eastern Pacific. Our results show that the wind anomalies are associated with the anomalously negative phase of the first two leading modes of the annual cycle (antisymmetric and symmetric modes about the equator) of sea surface temperature (SST) in the tropical Pacific. The two modes account for 82.2% and 13.5% of the total variance, linking to the seasonal swing of SST between the northern and southern hemispheres and the temporal evolution of El Niño-Southern Oscillation, respectively. During 2020–23, the persistently and anomalously negative phase of the symmetric mode enhances easterly wind over the tropical central Pacific, while the antisymmetric mode strengthens the southeasterly wind over the tropical eastern Pacific. The anomalously negative phase of the antisymmetric mode is associated with the contrast of SST anomalies between the northern and southern hemispheres, which provided a favorable background for the triple-dip La Niña in 2020–23.

Effect of Large-Scale Circulation Anomalies on Summer Rainfall over the Yangtze River Basin: Tropical versus Extratropical

Abstract This study investigates the tropical and extratropical circulation anomalies that directly affect the summer rainfall over the Yangtze River basin (YRB). In the lower troposphere, the tropical circulation anomalies that enhance the YRB rainfall manifest as an anticyclonic anomaly over the tropical western North Pacific (WNP) and the extratropical circulation anomalies are characterized by northeasterly anomalies to the north of the YRB. It is found that the heavier the YRB rainfall, the more necessary the cooperation between the tropical WNP anticyclonic anomaly and the midlatitude northeasterly anomalies, and compared to the tropical WNP anticyclonic anomaly, the midlatitude northeasterly anomalies can more efficiently induce the YRB rainfall. Further results indicate that the tropical WNP anticyclonic anomaly exhibits notable quasi-biweekly feature and provides a favorable background for the enhanced YRB rainfall. By contrast, the northeasterly anomalies are dominated by synoptic variability. Furthermore, there are significant precursor signals for the lower-tropospheric northeasterly anomalies. These signals manifest as the eastward propagation of two wave trains in the upper troposphere: a midlatitude one and a high-latitude one, which tend to be independent. The midlatitude one originates around the Mediterranean Sea and propagates eastward along the Asian westerly jet. The high-latitude one propagates over the high-latitude Eurasian continent, from Europe eastward to Lake Baikal and then southeastward to East Asia.

Human capital consequences of missing out on a grammar school education

This paper disentangles the effect of selective schooling on long-term human capital from that of individual background. The study design proxies entry test scores for selective secondary schools in England with historical data, estimating discontinuities in school assignment directly from the data. We find that, for the marginal admitted student, selective school attendance positively affects educational attainment. Adult labour market and health outcomes are not affected for the marginal admitted student. The effect on educational outcomes is conditional on having a favourable background, and partly explained by higher-ability peers and single-sex schools.

Mechanisms Governing the Formation and Long-Term Sustainment of a Northeastward Moving Southwest Vortex

From 10 July to 12 July 2021, a long-lived (~66 h) southwest vortex (SWV), moved from Southwest China to Northeast China and caused a series of heavy rainfall events. This SWV case was rarely seen, as its lifespan was much longer than the SWVs’ mean lifespan, and the vast majority of SWVs showed a quasi-stationary behavior. It was found that the SWV formed and sustained in favorable background environments, which were characterized by a strong upper-level divergence (related to the South Asia High), a notable middle-tropospheric warm advection (related to a shortwave trough), and a vigorous low-level jet. The SWV showed remarkable interactions with a middle-tropospheric mesoscale vortex. The strong southwesterly wind in the eastern section of a deep shortwave trough east of the Tibetan Plateau acted as the steering flow for the northeastward movement of both vortices. Vorticity budget showed that the convergence-related vertical stretching dominated the SWV’s formation and development; the convection-related upward transport of cyclonic vorticity was the most favorable factor for the SWV’s sustainment, whereas, during the decaying stage, the SWV dissipated mainly due to the tilting effects and the net export transport of cyclonic vorticity. Backward trajectory analyses showed that most of the air particles that formed the SWV (at its formation time) were sourced from the lower troposphere. These air particles mainly ascended and experienced a rapid increase in cyclonic vorticity during the SWV’s formation stage. The topography of the Yunnan–Guizhou Plateau was crucial for the SWV’s formation, as around a half of the air particles (that formed the SWV) came from this region. Most of these air particles enhanced in their cyclonic vorticity and convergence when they descended along the topography of the plateau.

Chapman–Jouguet deflagration criteria and compressibility dynamics of turbulent fast flames for turbulence-induced deflagration-to-detonation transition

This work characterizes the compressibility dynamics in turbulent fast flames for a range of turbulent flame speeds. These turbulent fast flames experience increased effects of compressibility through the formation of strong shocks and may develop a runaway acceleration combined with a pressure buildup that leads to turbulence induced deflagration-to-detonation transition (tDDT). Simultaneous high-speed particle image velocimetry, OH* chemiluminescence, schlieren, and pressure measurements are used to examine the reacting flow field and flame dynamics. We examine flames with turbulent flame speeds ranging from 100 to 600 m/s. At lower turbulent flame speeds, the flame is not able to produce favorable background conditions for deflagration-to-detonation transition (DDT) onset, and thus flame compressibility and turbulence amplification are less dominant, resulting in a weaker acoustic coupling between the flame and compressed region. As the turbulent burning velocities exceed the Chapman–Jouguet deflagration speed, favorable background conditions are produced, as we observe flame-generated shocks and flame-generated turbulence with higher turbulent velocities and larger turbulent scales. At this regime, the flame is categorized to be at the runaway transition regime that leads to tDDT.

Natural resources and rational nature management as one of the aspects of sustainable development of the territory

The article deals with natural resources, their organization and rational use from the point of view of ensuring the ecological sustainability of territories. The effective use of natural monuments will create the necessary favorable background for the territories and the life of the population.

Extreme Cold Events in North America and Eurasia in November-December 2022: A Potential Vorticity Gradient Perspective

From 17 November to 27 December 2022, extremely cold snowstorms frequently swept across North America and Eurasia. Diagnostic analysis reveals that these extreme cold events were closely related to the establishment of blocking circulations. Alaska Blocking (AB) and subsequent Ural Blocking (UB) episodes are linked to the phase transition of the North Atlantic Oscillation (NAO) and represent the main atmospheric regimes in the Northern Hemisphere. The downstream dispersion and propagation of Rossby wave packets from Alaska to East Asia provide a large-scale connection between AB and UB episodes. Based on the nonlinear multi-scale interaction (NMI) model, we found that the meridional potential vorticity gradient (PVy) in November and December of 2022 was anomalously weak in the mid-high latitudes from North America to Eurasia and provided a favorable background for the prolonged maintenance of UB and AB events and the generation of associated severe extreme snowstorms. However, the difference in the UB in terms of its persistence, location, and strength between November and December is related to the positive (negative) NAO in November (December). During the La Niña winter of 2022, the UB and AB events are related to the downward propagation of stratospheric anomalies, in addition to contributions by La Niña and low Arctic sea ice concentrations as they pertain to reducing PVy in mid-latitudes.