Sudden Events Research Articles

Clinical History of Patients with Hypertrophic Cardiomyopathy-How to Improve the Initiation Process of the Diagnosis?

Background: Regardless of genetic origin and recommended screening methods, hypertrophic cardiomyopathy (HCM) is commonly diagnosed late in the advanced stages of the disease. The aim of this study was to analyse the case history of patients with HCM in order to obtain an initiation of the diagnostic process. Methods: This study was a retrospective, tertiary, single-centre cohort analysis of 85 consecutive pts with HCM (mean age at the time of HCM diagnosis: 51 ± 15 years; F/M: 42/43) who were hospitalized during the period from 1 January 2013 to 31 December 2022. Type of referral to the hospital, the reason for hospitalization as well as accompanying symptoms, comorbidities, and family history were analysed to obtain an initiation of the diagnostic process. The analysis was limited to hospitalizations in which the diagnosis of HCM was stated for the first time. Results: An analysis of the type of referral to the hospital revealed the following data: 18% of patients were admitted as urgent hospitalizations (UHs) and 82% as elective hospitalizations (EHs). Among the UHs, the majority of patients were transferred from another hospital (13%), and among the EHs, 65% of patients were referred from a specialised outpatient medical care (SMC) facility. The majority of patients in both the UH and EH groups were symptomatic: 84% in the EH group (the most common symptom was exertional dyspnea in 56% of pts) and 93% in the UH group (the most common symptom was syncope in 60% of pts). Among the analysed population, the most frequent comorbidities were systemic hypertension (51%), lipid metabolism disorders (38%) and obesity (23%). Conclusions: A diagnosis of HCM is often made at an advanced age in symptomatic patients, mainly during an EH. Nearly one-fifth of the Polish HCM population is diagnosed during a UH after a sudden event, which suggests the need for improvements in medical care in Poland.

Unbalanced burden is escalating: Urban inequality landscape under sudden shocks?

Sudden and unforeseen events, notably the COVID-19 pandemic has underscored and exacerbated pre-existing urban inequalities. These disruptions have disproportionately affected the most vulnerable sectors of society, thereby further aggravating existing inequalities. Addressing these inequality issues requires systematic research into academic community's response to significant global disturbances. Therefore, we have integrated bibliometric analysis with meta-analysis (quantitatively combines research results from systematic reviews) techniques, culminating in a research framework based on KNIME software (a software for creating data applications and services) and Python programming. Noteworthy for its open-source nature, scalability, and reproducibility, this framework tries to decode the developmental patterns and response characteristics of urban inequality research under sudden shocks. Additionally, it seeks to clarify its causal pathways, predict the emergence of new or strengthened inequalities, and provide effective suggestions to promote inclusive and sustainable urban development. Our findings indicate that the COVID-19 has exacerbated the existing urban inequality, attracting widespread attention in fields such as society and public health. Issues of fairness and justice of human health, resource allocation, urban resilience and vulnerability have become hot topics around COVID-19 related urban inequalities. Simultaneously, the sudden shocks have led to disparities in research areas and themes. Social, economic, and urban planning are the main drivers behind urban inequality, and particularly affecting vulnerable groups, including low-income populations and those living in remote regions. Before and after the COVID-19, the average global urban inequality are 0.57 and 0.61, respectively. Inequality issues are particularly severe in Africa and countries such as Afghanistan, Pakistan, and India. The pandemic changed the focus of urban inequality to health and social issues, worsening inequality performance in these regions and deepening global gaps. Additionally, countries with high urban inequality are more prone to large-scale outbreaks and higher mortality rates. To this end, we advocate academia for in-depth research and comprehensive evaluation, focusing on vulnerable groups, providing integrated policy recommendations, supporting interdisciplinary exchanges and cooperation, and committing to find long-term sustainable solutions. These efforts aim to propose more comprehensive and reasonable solutions to alleviate and address complex urban inequality issues under sudden shocks.

Hypercholesterolemia - non-pharmacological treatment, monotherapy or combination therapy. Review of the literature

Introduction: As the number of scientific studies on lipid metabolism disorders increases, awareness among the medical community and the general population about the impact of hypercholesterolemia on the risk of cardiovascular diseases is growing. Elevated cholesterol levels in the blood are a major factor in the development of atherosclerosis, thereby increasing the likelihood of sudden cardiovascular events such as heart attacks or strokes. Maintaining normal cholesterol levels in the blood requires effective collaboration between the doctor and the patient, combining optimal pharmacotherapy with effective non-pharmacological methods based on the introduction of a balanced diet and moderate, regular physical activity. Current guidelines, based on numerous scientific studies, provide a clear framework for lipid-lowering treatment, with statins being an integral part. In cases where monotherapy is ineffective, ezetimibe and monoclonal antibodies, among others, can be used. In our work, we will discuss the possibilities of both non-pharmacological therapy and pharmacotherapy. Aim of the study: The aim of this study is to review current knowledge on non-pharmacological and pharmacological therapy in hypercholesterolemia. Material and method: This article presents the current state of knowledge about non-pharmacological and pharmacological therapy in hypercholesterolemia. Publications reviewed using the PubMed platform contain recent report in field of lipid metabolism disorders. The search included the keywords: ‚Hypercholesterolemia’, ‚LDL-C’, ‚Statin’, ,Ezetimibe’, ,PCSK9 inhibitors’.

Uncovering the Sino‐US Dynamic Risk Spillovers Effects: Evidence From Agricultural Futures Markets

ABSTRACTWith economic globalization and the financialization of agricultural products continuing to advance, the interconnections between different agricultural futures have become closer. We utilize a TVP‐VAR‐DY model combined with the quantile method to measure the risk spillover between 11 agricultural futures in the United States and China from July 9, 2014, to December 31, 2022. We obtain several findings. First, CBOT corn, soybean, and wheat are identified as the primary risk transmitters, with DCE corn and soybean as the main risk receivers. Second, sudden events or increased economic uncertainty can enlarge the overall risk spillovers. Third, there is an aggregation of risk spillovers amongst agricultural futures based on the dynamic directional spillovers. Lastly, the central agricultural futures under the conditional mean are CBOT corn and soybean, while CZCE hard wheat and long‐grained rice are the two risk‐spillover centers in extreme cases, as per the results of the spillover network and minimum spanning tree.

Multisystemic inflammatory disease in Pheasantshell (Unionidae, Actinonaias pectorosa) associated with Yokenella regensburgei infection at sites experiencing seasonal mass mortality events.

Freshwater mussels are integral components of riverine ecosystems, influencing water quality, nutrient cycling, and habitat characteristics. Enigmatic freshwater mussel declines, often characterized by sudden mass mortality events, pose significant challenges to conservation efforts. The Clinch River, a freshwater biodiversity hotspot in Virginia and Tennessee, USA, has experienced several enigmatic mass mortality events since 2016. Studies have reported bacteria associated with moribund Pheasantshell (Actinonaias pectorosa) during mortality events in the Clinch River, specifically Yokenella regensburgei. Despite reports of bacterial infection, little is known about their role as pathogens. Through a multiyear case-control study, combining in-situ experiments, field surveys, histology, bacterial isolation, and high-throughput sequencing, we assessed the role of bacteria in Pheasantshell (Actinonais pectorosa) mortality at three sites in the Clinch River. Between May 2021 and December 2023, we collected 21 wild moribund free-living A. pectorosa and 68 hatchery-reared A. pectorosa maintained in silos at the same sites and investigated differences in pathology and microbiologye between groups. No silo mussels presented clinical signs of disease, or gross or microscopic lesions associated with pathological conditions leading to mortality. Our findings reveal a significant association between Yokenella regensburgei and severe multisystemic and multifocal infiltrative hemocytosis with necrosis, consistent with sepsis. Lesions associated with yokenellosis were of sufficient severity and physiological significance to explain mortality in infected hosts. Although our study does not explain the cause of these infections, it confirms that mussels at our study sites are ultimately dying with an infectious disease and that Y. regensburgei can be pathogenic in free-living mussels. Our results underscore the importance of considering bacterial diseases in wild mussel populations and emphasize the need for further research to elucidate the epidemiology and pathogenicity of Y. regensburgei. Overall, our study highlights the importance of integrated approaches combining pathology, microbiology, and epidemiology in freshwater mussel conservation efforts.

Mechanistic Insights and Genetic Approaches for Enhancing Submergence Tolerance in Rice

Rice, a pivotal staple crop, serves as a dietary foundation for approximately half of the global population. Its cultivation, traditionally reliant on submerged conditions, faces significant challenges due to sudden flooding events. The majority of rice varieties are highly sensitive to prolonged submersion beyond a mere seven days, resulting in substantial yield losses. As global climate patterns shift, the occurrence and intensity of flooding are predictable to increase, exacerbating this issue. Therefore, development of rice varieties having enhanced submergence tolerance is critical to sustaining productivity and ensuring food security in flood-prone regions. Understanding the physiological and biochemical mechanisms underlying submergence tolerance is crucial in this context. Key physiological mechanisms include the regulation of carbohydrate reserves for energy during low oxygen availability, ethylene-responsive factors, especially the Sub1A gene to, regulate growth and stress responses, curbing excessive elongation to conserve energy and enhance survival. Additionally, specialized tissues such as aerenchyma and adventitious roots improve oxygen transport and nutrient uptake under flooded conditions. Genetic approaches, including Marker-Assisted Selection (MAS), have been instrumental in the development of submergence-tolerant rice varieties. The integration of the Sub1 QTL, especially the Sub1A gene, into high-yielding rice varieties has led to significant advancements in breeding submergence-tolerant cultivars. These genetic improvements provide a promising solution to mitigate the detrimental effects of flooding on rice production, ensuring the stability and sustainability of this essential crop in the face of changing climate conditions. This review discusses various mechanisms adapted by rice and genetic advancements aimed at enhancing submergence tolerance in rice to secure food production for future generations.

Spatial Allocation Rationality Analysis of Medical Resources Based on Multi-Source Data: Case Study of Taiyuan, China.

Reasonably allocating medical resources can effsectively optimize the utilization efficiency of such resources. This paper took Taiyuan City as an example and established a model to evaluate the rationality of medical resource spatial allocation, incorporating two key dimensions: the spatial layout and the supply and demand of medical resources. In terms of the spatial layout, three indexes were included: Firstly, the service coverage rates of different levels of medical institutions, based on residents' medical orientations, were calculated using network analysis methods. Secondly, the Huff-2SFCA method was improved to calculate the accessibility of medical resources for four different modes of transportation. Then, the Health Resource Agglomeration Degree (HRAD) and Population Agglomeration Degree (PAD) were used to quantify the equity of medical resources. In terms of the supply and demand of medical resources, one index was included: the supply-demand ratio of medical resources during sudden public health events, which was calculated using the number of beds per thousand people as an indicator. These four indexes were weighted using the entropy weight method to obtain the rationality grade of medical resource spatial allocation in Taiyuan City. The study found that the rationality evaluation level of medical resource allocation in the central urban area of Taiyuan City followed a "concentrically decreasing" pattern. The rating ranged from "very reasonable" to "less reasonable", with the area of each level expanding gradually. The areas rated within the top two categories only accounted for 19.92% of the study area, while the area rated as "less reasonable" occupied 38.73% of the total area. These results indicate that the model accounted for residents' travel for various medical orientations and the availability of resources during public health emergencies. It considered both the spatial layout and supply and demand of medical resources, offering recommendations for the precise allocation of urban medical resources.

Impaired vascular function among young users of anabolic–androgenic steroids

Supraphysiological doses of anabolic–androgenic steroids (AAS) is popular among recreational weightlifters and bodybuilders due to the performance-enhancing properties but is also associated with adverse cardiovascular effects. The knowledge about how AAS affect the vasculature is limited, although results from previous studies suggest alterations in vasoreactivity and morphology. In the present study we investigate the association between long-term use of AAS and vascular function. Hundred and twenty-three males were included in the study, 56 of them current AAS users and 67 weightlifting controls. Vascular function was evaluated by carotid artery reactivity and flow-mediated dilation. AAS users had significantly reduced carotid artery reactivity (p < 0.001) and flow-mediated dilation (p < 0.001) compared to weightlifting controls. Results from the present study indicate that long-term use of AAS affect the cardiovascular system negatively, measured as reduced carotid artery reactivity and flow-mediated dilation. These findings could partly explain sudden cardiovascular events among young long-term users of AAS.

Climate change loss and damage from droughts: key insights from Fiji’s sugar industry

ABSTRACT Climate change loss and damage (L&D) due to both sudden and slow-onset events are a growing concern for vulnerable countries. Over the last decade, agricultural communities in Fiji have suffered a range of serious L&D from severe drought events. Through a grounded theoretical lens, qualitative research was used to gain in-depth insights into L&D from droughts in the Fijian sugar industry. In-depth semi-structured interviews (n = 68) were conducted in two Indo-Fijian sugarcane communities, Barotu and Toko settlements in Western Viti Levu, Fiji, and with key stakeholders from government ministries, academia, and climate change experts at the national level. Purposive sampling was initially used to identify smallholder sugarcane farmers and key stakeholders. Theoretical sampling further identified key stakeholders for the interview. Despite implementing various adaptation measures, the Fijian sugar industry has suffered severe L&D, including non-economic L&D (NELD) and associated cascading effects. L&D included reduced yields, loss of crops, and reduced income. NELD included deterioration of mental, physical, and emotional health, loss of hope, and uncertainty. Cascading effects included increased food insecurity risks and impacts on children’s education. Key policy interventions are recommended, such as removing adaptation constraints, developing drought risk profiles and early warning systems, investing in livelihood diversification, and engaging in new markets to facilitate social and ecological transformations that will promote livelihood resilience. Key Policy Highlights: Climatic and non-climatic stressors are inherently interconnected and interact in a complex and complicated manner to enhance social-ecological systems (SES) vulnerability. Inadequate drought adaptation measures further marginalise farmers and ultimately increase their vulnerability to drought risks and loss and damage (L&D). L&D presents itself in various ways, including non-economic L&D and cascading effects that are impacting upon future generations. With projected climate change and the likelihood of impacts worsening, there is an urgency to address L&D more coherently through crucial policy interventions.

Mediating effects of insomnia and resilience on COVID-19-related post-traumatic stress disorder and quality of life in adolescents

The coronavirus disease-2019 (COVID-19) pandemic has impaired the quality of life (QoL) for many due to its extensive impacts. However, few studies have addressed the specific impact of COVID-19 on the mental health of adolescents, particularly post-traumatic stress disorder (PTSD). This study considered the impact of COVID-19-related PTSD on the QoL of adolescents in China, the mediating effects of insomnia, and the moderating effects of resilience. Participants included 50,666 adolescents aged 12–18 years selected using a comprehensive sampling method. We performed data collection from January 8th to January 18th, 2023, using the Children’s Revised Impact of Event Scale, Pittsburgh Sleep Quality Index, Ten-item Connor-Davidson Resilience Scale, and Screening for and Promotion of Health-related QoL in Children and Adolescents Questionnaire for data collection. Male adolescents exhibited significantly lower levels of PTSD and insomnia compared to females and scored significantly higher in psychological resilience and overall QoL. Insomnia played a mediating role between PTSD and QoL. Psychological resilience moderated the impact of COVID-19-related stress on adolescents’ QoL through its influence on insomnia. PTSD resulting from the COVID-19 pandemic affects the QoL of adolescents through the presence of insomnia. Psychological resilience plays a moderating role in this process. Cultivating psychological resilience in adolescents can effectively enhance their ability to cope with the impacts of sudden public events.

Quasi-critical dynamics in large-scale social systems regulated by sudden events.

How do heterogeneous individual behaviors arise in response to sudden events and how do they shape large-scale social dynamics? Based on a five-year naturalistic observation of individual purchasing behaviors, we extract the long-term consumption dynamics of diverse commodities from approximately 2.2 million purchase orders. We subdivide the consumption dynamics into trend, seasonal, and random components and analyze them using a renormalization group. We discover that the coronavirus pandemic, a sudden event acting on the social system, regulates the scaling and criticality of consumption dynamics. On a large time scale, the long-term dynamics of the system, regardless of arising from trend, seasonal, or random individual behaviors, is pushed toward a quasi-critical region between independent (i.e., the consumption behaviors of different commodities are irrelevant) and correlated (i.e., the consumption behaviors of different commodities are interrelated) phases as the pandemic erupts. On a small time scale, short-term consumption dynamics exhibits more diverse responses to the pandemic. While the trend and random behaviors of individuals are driven to quasi-criticality and exhibit scale-invariance as the pandemic breaks out, seasonal behaviors are more robust against regulations. Overall, these discoveries provide insights into how quasi-critical macroscopic dynamics emerges in heterogeneous social systems to enhance system reactivity to sudden events while there may exist specific system components maintaining robustness as a reflection of system stability.

Designing a model of emergency medical services preparedness in response to mass casualty incidents: a mixed-method study

BackgroundEmergency medical services preparedness in mass casualty incidents is one of the most important concerns in emergency systems. A mass casualty incident is a sudden event with several injured individuals that overwhelms the local health care system. This study aimed to identify and validate the components of emergency medical services readiness in mass casualty incidents which ultimately led to designing a conceptual model.MethodsThis research was an explanatory mixed-method study conducted in five consecutive stages in Iran between November 2021 and September 2023. First, a systematic review was carried out to extract the components of emergency medical services preparedness in mass casualty incidents based on the PRISMA guideline. Second, a qualitative study was designed to explore the preparedness components through in-depth semi-structured interviews and analyzed using the content analysis approach. Third, the integration of the components extracted from the two stages of the systematic review and qualitative study was done by an expert panel. Fourth, the obtained components were validated using the Delphi technique. Two rounds were done in the Delphi phase. Finally, the conceptual model of emergency medical services preparedness in mass casualty incidents was designed by a panel of experts.Results10 articles were included in the systematic review stage and sixteen main components were extracted and classified into four categories. In the second stage, thirteen components were extracted from the qualitative study and classified into five categories. Then, the components of the previous two phases were integrated into the panel of experts and 23 components were identified. After validation with the Delphi technique, 22 components were extracted. Lastly, the final components were examined by the panel of experts, and the conceptual schematic of the model was drawn.ConclusionsIt is necessary to have an integrated framework and model of emergency medical service readiness in the planning and management of mass casualty incidents. The components and the final model of this research were obtained after the systematic scientific steps, which can be used as a scheme to improve emergency medical service preparedness in response to mass casualty incidents.

A Proximization Study of Critical Discourse Analysis---Taking the Documentary Itaewon Crush as an Example

Based on the documentary Itaewon Crush, guided by proximization theory, this paper makes a comparative study of the discourse strategies of the documentary on the theme of sudden catastrophic events from two aspects: negative proximization and positive proximization. It is found that the entities recognized to be ODCs and IDCs, the use of lexical items, and the communication effects achieved are different in negative proximization and positive proximization. The former takes government and disaster as the external threat to the deictic center, emphasizing the serious consequences of disasters and government actions to realize the documentary’s warning effect. The latter establishes a positive influence between the external entities and the deictic center to achieve the documentary’s humanistic value.

A dynamic snow depth retrieval model based on time-series clustering optimization for GPS-IR

Due to the influence of environmental factors (i.e., terrain and surface coverage) around the GPS receivers, the snow depth retrieval results obtained by the existing global positioning system interferometric reflection (GPS-IR) method show significant variability. The resulting loss of reliability and accuracy limits the broad application of this technology. Therefore, this paper proposes a dynamic snow depth retrieval model based on time-series clustering optimization for GPS-IR to fully leverage multi-source satellite observation data for automatic and high-precision snow depth retrieval. The model employs Dynamic Time Warping distance measurement combined with the K-Medoids clustering algorithm to categorize frequency sequences obtained from various satellite trajectories, facilitating effective integration of multi-constellation data and acquisition of optimal datasets. Additionally, Long Short-Term Memory networks are integrated to capture and process the long-term dependencies in snow depth data, enhancing the model’s adaptability in handling time-series data. Validated against SNOTEL measured data and standard machine learning algorithms (such as BP Neural Networks, RBF, and SVM), the model’s retrieval capability is confirmed. For P351 and AB39 sites, the correlation coefficients for L1 band data retrieval were both 0.996, with RMSEs of 0.051 and 0.018 m, respectively. The experiment results show that the proposed model demonstrates superior precision and robustness in snow depth retrieval compared to the previous method. Then, we analyze the accuracy loss caused by sudden snowfall events. The proposed model and methodology offer new insights into the in-depth study of snow depth monitoring.

Oasis civilization collapse under 3.9 ka climate event in Bactria, Central Asia

Central Asia played a significant role in the early exchange of civilizations across Eurasia. The arid climate, which makes the local ecology sensitive to climate change and the well-preserved archaeological remains, make Central Asia an ideal location for studying the mechanisms of interactions between civilization evolution and environmental change. This research presents archaeobotanical, palynological and stable isotope records from the Djarkutan site in southeastern Uzbekistan, which was occupied between 4100 and 3700 cal yr BP. Our research shows that in the Late Bronze Age, after 4000 yr BP, the local agricultural structure was highly complex. Pollen and stable isotope result indicate a sudden drought event occurred in the local area around 3900 yr BP, which had an impact on the local oasis agricultural system. Subsequently, this event promoted the migration of northern steppe populations into Central Asia, leading to the development of an agro-pastoral economy in the research area.

Advancing Wireless Strain Sensing with Low-cost Printable Supersensitive Radiofrequency Patches

Engineering structures experience changes in material and functional properties due to structural damage, induced by sudden events or gradual degradation over time. Structural Health Monitoring (SHM) is crucial, utilizing real-time monitoring systems with various sensors. Suitable sensors for monitoring structures are vital for future economies. They should feature sensitivity, cost-effectiveness, easy integration, and reduced complexity. Current strain sensors, like strain gauges and Fiber-optic Brag Gratings (FBG), are sensitive but have drawbacks, including wiring complexities, installation time, and limited lifetimes. Introducing wireless sensors as a solution, enables autonomous strain monitoring, overcoming the drawbacks of traditional wired sensors. Chipless Radio Frequency (RF) technology, specifically passive RF sensors, stands out for smart structure development. These sensors, relying on RF readers for power, offer compactness, non-intrusiveness, longer lifetimes, and cost-effectiveness, making them promising for monitoring large structures. This research aims to develop an innovative chipless RF strain sensor for wireless communication, emphasizing enhanced sensitivity and seamless integration into real structures for integrity monitoring. First, the structure and processing technique of such sensors will be presented. Second, an external readout coil connected to a vector network analyzer was used to make electromagnetic coupling with the receiver coil in the sensor and resonate the sensor on its resonant frequency. When experiencing strain, the signal activates a transmission line mechanism, increasing the attenuation along the capacitive element. The consequence is a strong variation in the effective sensor length making a remarkable variation in the resonant frequency. We demonstrate the exceptional gauge factor in the resonant frequency at different strain levels, which gives our sensor a big advantage, compared to pure resistive sensors and geometrically related capacitive sensors. We also demonstrate that such sensors can be fabricated in large quantities at very low cost as they are by design compatible with classical printing technologies.

The importance and use of defibrillation in pediatric surgery

Pediatric surgery is a delicate and complex process. Anatomical and physiological characteristics of pediatric patients are different compared to adults and this may increase the risk for some complications during surgical interventions. Complications that may occur during surgical procedures may include sudden cardiac events and cardiac arrest. These situations are among the emergencies that require rapid intervention and one of the most effective tools of this is defibrillation. Defibrillation is a procedure that is used to correct the life-threatening arrhythmia (ventricular fibrillation and pulseless ventricular tachycardia). This procedure aims to restore normal rhythm through electric shock to the heart. In children, defibrillation requires great care in terms of correct timing and using appropriate energy levels. Since incorrect practices may cause serious harm, correct use of defibrillation is vital in the management of possible complications during pediatric surgery.

Implementation of extended kalman filter for localization of ambulance robot

AbstractThis paper focuses on the implementation of the Extended Kalman Filter for indoor localization of a semi-autonomous Ambulance Robot system named Ambubot. The system is designed to reduce the response time for lay rescuers to locate an Automated External Defibrillator (AED) during sudden cardiac arrest events. To achieve this objective, the robot is equipped with an AED, and the Extended Kalman Filter is utilized for optimal indoor localization. The filter is implemented using data from the robot’s Inertial Measurement Unit, which comprises 9 Degrees of Freedom. The paper provides an explicit description of the performance of the Extended Kalman Filter in estimating the position of Ambubot, and demonstrates that the proposed approach is effective in accurately determining and estimating the robot’s position in unknown indoor environments. The results suggest that the proposed method is a promising solution for improving survival rates in cardiac arrest cases, and may have potential applications in other fields where accurate indoor localization is required.

Large-scale dynamic processes during the minor and major sudden stratospheric warming events in January–February 2023

Using data from reanalyses of meteorological information, this study examines peculiarities of the thermodynamic regime of the Arctic stratosphere in the winter season of 2022–2023. For this purpose, components of the global meridional circulation, wave activity fluxes, volume of polar stratospheric clouds type I (PSC NAT) are analyzed, as well as changes in these indicators during sudden stratospheric warming (SSW) events formed in January–February. The main features of the 2022–2023 winter season were the following: (1) a persistent cold stratospheric polar vortex was observed until mid-January, which caused the PSC NAT volume growth to its maximum values since 1980; (2) enhanced wave activity from mid-January led to the formation of a minor SSW at the end of January, an increase in the temperature of the lower stratosphere and a sharp reduction in PSC NAT; (3) a week of intensification of the polar vortex was then observed, followed by a weakening due to the next burst of wave activity propagation during the second SSW event in mid-February. This second SSW event was major, accompanied by a reversal of the mean zonal wind, which lasted until early March; (4) meridional heat flux in January–February 2023 was the highest since 1948, resulting in unprecedented warming of the lower Arctic stratosphere and preventing ozone depletion in March; (5) the minor SSW at the end of January was accompanied by a more intense change in the meridional circulation than the major SSW in mid-February. Formation of ozone mini-hole over Northern and Central Europe in February 2023 was associated with the strengthening of the anticyclone, leading to a stratopause elevation and northward transport of ozone-poor air masses from the subtropics along the western periphery of the anticyclone additionally to related to the major SSW temperature changes affected the ozone concentration in the lower stratosphere.

The Influence of Climate Change on the Distribution of Hibiscus mutabilis in China: MaxEnt Model-Based Prediction.

Our study utilized 374 geographical distribution records of H. mutabilis and 19 bioclimatic factors, employing the MaxEnt model and the Geographic Information System (ArcGIS). The key environmental variables influencing the suitable distribution areas of H. mutabilis were analyzed through the comprehensive contribution rate, permutation importance, and Pearson correlation coefficient. Based on this analysis, the contemporary and future suitable distribution areas and their extents were predicted. The results indicate that the key limiting factor affecting the suitable distribution areas of H. mutabilis is the precipitation of the driest month (bio14), with secondary factors being annual precipitation (bio12), annual mean temperature (bio1), and annual temperature range (bio7). Under contemporary climate conditions, the total suitable area for H. mutabilis is approximately 2,076,600 km2, primarily concentrated in the tropical and subtropical regions of southeastern China. Under low-to-medium-emission scenarios (SSP1-2.6, SSP2-4.5), the total suitable area of H. mutabilis shows a trend of first decreasing and then increasing compared to the current scenario. In contrast, under high-emission scenarios (SSP5-8.5), it exhibits a trend of first increasing and then decreasing. The spatial pattern changes indicate that the retention rate of suitable areas for H. mutabilis ranges from 95.28% to 99.28%, with the distribution centers primarily located in Hunan and Guizhou provinces, showing an overall migration trend towards the west and north. These findings suggest that H. mutabilis possesses a certain level of adaptability to climate change. However, it is crucial to consider regional drought and sudden drought events in practical cultivation and introduction processes. The results of our study provide a scientific basis for the rational cultivation management, conservation, and utilization of germplasm resources of H. mutabilis.