Average Winter Temperatures Research Articles

Solar PV system with maximum power tracking

The paper investigates the state-of-the-art architecture of photovoltaic systems (PVS) by evaluating the performance of the developed maximum power point tracking (MPPT) algorithm of fuzzy particle swarm optimization (FPSO) for temperate continental latitudes. The material of the paper gives an evaluation of traditional MPPT algorithms in relation to the state-of-the-art FPSO algorithm. The study summarizes the problems of On-Grid PV systems and analyzes methods of solving them by combining them with hydrogen technologies. The paper summaries the experience of observations of climatic factors and solar resources on the example of the Russian Federation. Thus, in 2023, the average winter temperature exceeded the norm by 4.7 °C, and the average summer temperature exceeded the norm by 4.9 °C compared to 2022. The paper analyses the level of insolation, which increased by 0.03 kWh/m2 by regions of Russia for the period 2022–2023. The experimental part of the work was carried out at the solar power plant (SPP) «Kalmykskaya» with coordinates 53.422832 north latitude and 55.266895 east longitude. The watt-volt field characteristic of photovoltaic modules (PVM) connected to the inverter was obtained experimentally. When compared, the correlation coefficient between the experimental power (P) and voltage (U) of the panels was found to be higher than that of the ideal panels, 0.933 versus 0.914. The correlation coefficient between the ideal P(U) function and the experimental one is (−0.475). The data for calculating the coefficient of performance (COP) of the implemented MPPT algorithm was also obtained experimentally, which was about 98.7%. The reliability of the data used in the calculations was confirmed by two independent means of measurement, the difference of the obtained results was less than 1%. In the last part of the experiment of this study, the dependence of insolation in a given geographical point on the generated PV field power was evaluated. The correlation coefficient was 0.47, while the inverter output voltage was maintained in the nominal range of (600 ± 20%)V. Thus, the authors of the study experimentally proved the efficiency of using MPPT on FPSO in temperate continental climate with duration of sunshine T = 1850 h per year. The effectiveness of the FPSO algorithm under the conditions of inverter distance from the common point of the DC switching cabinet (DСCC) has been confirmed. The effectiveness of the MPPT algorithm based on FPSO under conditions of partial shading, increased cloud cover and increased air temperature is concluded. Using the description of the current architecture of On-Grid SPP, the authors draw attention to the impossibility of operation of such systems without the presence of voltage in the reference network. In addition, the impossibility of the system operation at the value of PVM power over 1500 kW and at the voltage of panels less than 900 V is noted. To modernize the existing PVS architecture, for the first time, the use of a DCCC and an inverter with implemented MPPT on the FPSO in combination with a hydrogen (H2) production unit and nickel-hydrogen (Ni–H2) batteries is proposed. The researchers propose that when the PVM field voltage is below 900 V and when the PVM field power exceeds 1500 kW, energy can be diverted to H2 generation or to charge Ni–H2 batteries via a DCCC controller. Such an architecture will improve the continuity and efficiency of the PVS, reduce the carbon footprint, and allow the PVS to be used as an industrial uninterruptible power supply (UPS). The authors see the lack of standardization of implemented projects based on the ESG principle as the main problem of alternative energy development.

Off-Season Swarming in the Japanese Honey Bee (Apis Cerana Japonica)

Abstract Several studies have reported fragmentary evidence that climate change is altering the phenology and behavior of honey bees. We compiled records of off-season swarming of the Japanese honey bee (Apis cerana japonica) between autumn and winter to improve our understanding of the impact of climate change on the subspecies’ swarming phenology. Based on a survey of 311 beekeepers, eleven off-season swarming records were collected, with ten of them are from 2020 onward. The beekeepers who reported off-season swarming records had eight to twenty years of beekeeping experience, and they declared that they were witnessing off-season swarming for the first time, suggesting a recent increase. One possible factor contributing to the increase in off-season swarming is the temperature rise, as average autumn and winter temperatures in Japan have been increasing.

Long-term exposure to air pollution, greenness and temperature and survival after a nonfatal myocardial infarction

BackgroundLittle is known about the impact of environmental exposures on mortality risk after a myocardial infarction (MI). ObjectiveThe goal of this study was to evaluate associations of long-term temperature, air pollution and greenness exposures with mortality among survivors of an MI. MethodsWe used data from the US-based Nurses’ Health Study to construct an open cohort of survivors of a nonfatal MI 1990–2017. Participants entered the cohort when they had a nonfatal MI, and were followed until death, loss to follow-up, end of follow-up, or they reached 80 years old, whichever came earliest. We assessed residential 12-month moving average fine particulate matter (PM2.5) and nitrogen dioxide (NO2), satellite-based annual average greenness (in a circular 1230 m buffer), summer average temperature and winter average temperature. We used Cox proportional hazard models adjusted for potential confounders to assess hazard ratios (HR and 95% confidence intervals). We also assessed potential effect modification. ResultsAmong 2262 survivors of a nonfatal MI, we observed 892 deaths during 19,216 person years of follow-up. In single-exposure models, we observed a HR (95%CI) of 1.20 (1.04, 1.37) per 10 ppb NO2 increase and suggestive positive associations were observed for PM2.5, lower greenness, warmer summer average temperature and colder winter average temperature. In multi-exposure models, associations of summer and winter average temperature remained stable, while associations of NO2, PM2.5 and greenness attenuated. The strength of some associations was modified by other exposures. For example, associations of greenness (HR = 0.88 (0.78, 0.98) per 0.1) were more pronounced for participants in areas with a lower winter average temperature. ConclusionWe observed associations of air pollution, greenness and temperature with mortality among MI survivors. Some associations were confounded or modified by other exposures, indicating that it is important to explore the combined impact of environmental exposures.

Preference for hibernacula microclimates varies among 3 bat species susceptible to white-nose syndrome

Abstract North American bat populations have experienced precipitous declines since the introduction of white-nose syndrome (WNS). Evidence that bats have responded to WNS by altering their winter habitat selection has been used to manipulate underground environments and improve winter survival. However, such management practices must be based on local data, which do not exist for all regions. Our goal was to identify determinants of winter habitat use for 3 bat species with varying susceptibility to WNS. To do so, we conducted 188 surveys of 129 potential hibernacula over 3 winters. We found that the range of winter temperatures and presence of water were important for the Little Brown Myotis (Myotis lucifugus) and Tricolored Bat (Perimyotis subflavus), species that are highly susceptible to WNS. Counts of both species were greater in sites with a narrow (<5 °C) temperature range and where streams or water bodies >25 m2 were present. In addition, we found larger groups of Little Brown Myotis in abandoned railroad tunnels than in caves. Winter counts of these species increased over time at 3 railroad tunnels that were surveyed for 3 consecutive winters, whereas populations were extirpated from historically important caves and mines. Counts of Big Brown Bats (Eptesicus fuscus), which are less susceptible to WNS, were also greater in hibernacula with water bodies. However, average winter temperature also helped predict counts of Big Brown Bats. This species had a curvilinear response to temperature, with most bats found at hibernacula with average winter temperatures of 4 to 6 °C, and fewer bats observed at warmer and colder conditions. These data show that focusing solely on historically important hibernacula may fail to achieve conservation goals for the Little Brown Myotis and Tricolored Bat in our region, and suggest that anthropogenic structures can provide habitat for remnant populations of imperiled bat species.

A National Database Analysis: Does Cold Weather Affect the Surgical Intervention Rate for Developmental Dysplasia of the Hip in Children Under Five Years?

Background Cold weather in the first few months of life may increase the risk of a late diagnosis of developmental dysplasia of the hip (DDH). Early detection of DDH can often be treated non-surgically. The purpose of this study is to observe whether the rates of surgical intervention for DDH differ based on average outdoor temperatures in the winter months. Methods A retrospective observational study of DDH patients diagnosed from 2010 to 2021 was conducted using a national administrative database. Five geographic regions were defined based on the average temperatures in the coldest quarter of the year. The rates of DDH-related surgeries were compared across these temperature regions. Results A total of 55,911 patients ≤5 years old with a DDH diagnosis from 2010 to 2021 were identified in the database. When compared to the warmest region (Group 5), the coldest region (Group 1) had higher rates of open reduction (4.59% vs. 2.06%, p<0.001), adductor tenotomy (6.95% vs. 2.91%, p<0.001), femoral osteotomy (5.75% vs. 2.04%, p<0.001), pelvic osteotomy (5.27% vs. 2.04%, p<0.001), and total DDH surgeries (11.42% vs. 5.03%, p<0.001). Conclusion Children living in states with an average winter temperature of -6.17°C had an increased likelihood of requiring surgical intervention for DDH within the first five years of life.

Research on Energy Consumption Model of Heat Pump Air Conditioning System for New Energy Vehicles Based on Digital Technology

Energy shortages and environmental degradation are issues that are getting more and more significant globally. New energy vehicles are being promoted by the state due to the advantages of low pollution and low fuel consumption. However, due to battery technology, the range of new energy vehicles cannot meet the needs of users. As the most energy-efficient auxiliary device, the energy consumption of air conditioning will significantly reduce the range of new energy vehicles. In low temperature environments, heating energy consumption will reduce the range of vehicles by more than 50%. Therefore, the research aims to reduce the energy consumption of air conditioning systems in new energy vehicles by reducing load demand and improving operating efficiency. The study designs a low-temperature heat pump air conditioning system based on digital technology and then uses a computational algorithm to construct an energy consumption model for the heat pump air conditioning system of a new energy vehicle. According to the test results, the system’s average increase in heat production after activating the enthalpy charge is 35% and its average COP is 0.14% lower than when switched off. At -5oC, the air outlet temperature of the system reaches up to 50.0oC. Summer cooling energy consumption increases exponentially with temperature, while winter heating energy consumption decreases linearly with temperature. In addition, the range decreases significantly as the ambient temperature deviates from the human comfort zone. The decline in the winter range is more severe than that in summer, moreover, the range of modern energy vehicles is reduced by 30% at an average winter temperature of -10oC. In summary, the low-temperature heat pump system offers greater performance. It is more useful in real-world applications and can offer a rational alternative to air conditioning’s energy-saving tactics.

Methodological approach to determining the area of air recycling on metro lines with double track tunnels

The article discusses the issues of operating existing metro lines with double-track tunnels. Significant differences between average annual, average monthly and extreme values of outdoor air temperature affecting the thermodynamic and thermophysical parameters of the mine atmosphere of subway tunnels, both in Russia and abroad, are analyzed. The results of a comprehensive analysis of the conditions that determine the temperature regime of the lines of double-track tunnels are presented. Air recirculation in the tunnels has been determined considering climatic conditions. Engineering and technical calculations have been carried out in metro tunnels when the seasonal periods of their operation change. Each of these periods is characterized by its own temperature, for example, for the winter period these are: average winter temperatures, temperatures of the coldest month, the coldest five-day period. The obtained results of the research work will make it possible to select the amount of air for each specific variant of the year, which will ensure, during the operation of this kind of metro lines, the standard thermodynamic parameters of the air environment, both in underground stations and in metro tunnels, and possibly lead to a positive economic effect.

Climatic changes in the forest and steppe zones of the Volga region and the Urals

The article analyses the dynamics of changes in the main components of the climate. The variability and cyclicity of the climate and the weather conditions forming it by year, autumn-winter period and vegetation period of grain crops on arable lands in the forest and steppe zones of the Volga region and the Urals for the entire period of meteorological observations is studied. Differences in the rates of climate change over time and by seasons have been revealed. Annual precipitation, on average in 1887-2020, per 100 years, increased by 55 mm, mainly due to precipitation in winter. The average annual air temperature increased by 1.8 °C, the average air temperature in winter by 2.3 °C and the average air temperature in summer by 1 °C. The air temperature in the steppe zone increases 20% faster compared to the forest zone.

Vairimorpha apis Versus Vairimorpha ceranae, Replacement or Dynamic Prevalence?

Abstract Nosematosis is currently a frequently discussed disease of bees caused by two species of microsporidia: Vairimorpha apis, and Vairimorpha ceranae. Vairimorpha apis represents the original species of Apis mellifera parasite, and Vairimorpha ceranae, is a species introduced from Asia. In the last two decades, epidemiological data on the growth of the prevalence of V. ceranae infection have increased, which has led to its dominant position at the expense of its congener V. apis, practically all over the world. This process is assumed to be the result of asymmetric competition within the host, where V. ceranae, showed a better ability to adapt to higher temperatures, which was first manifested by its spread in warmer climate zones. However, several results of studies from recent years somewhat unexpectedly showed that it is premature to talk about the complete replacement of V. apis by V. ceranae. They pointed to a greater influence of seasonality and average temperatures in winter and summer in a given year on the result of the current prevalence of infection and co-infection of Vairimorpha spp., regardless of the climatic zone in which the colonies were located. Considering the different clinical and subclinical manifestations of infection caused by V. apis, and V. ceranae, and its impact on the defense, survival and productivity of bee colonies, the aim of our work was to analyze the factors affecting the distribution and prevalence of Vairimorpha spp.

Italian Ryegrass as a Forage Crop for the Baltics: Opportunities and Challenges in Light of Climate Change.

Grasslands are important for sustainable milk and meat production as well as for providing other ecosystem services. One of the most productive components of short-term grasslands is Italian ryegrass (Lolium multiflorum subsp. italicum Lam.), offering high yield, excellent feed value, and high palatability to animals but low tolerance to abiotic stress. Global climate warming opens new opportunities and could be beneficial in increasing the potential of biomass production. In this study, we aimed to assess an Italian ryegrass cultivar of Lithuanian origin, 'Ugnė', for productivity and yield stability, with special emphasis on their relationship with climatic factors over a period of 14 years. The average winter temperatures and total spring precipitation explained 51% of the first-cut dry matter yield (DMY) variance. Second- and third-cut DMYs were associated with average temperature only. Italian ryegrass cv. 'Ugnė' demonstrated the potential to produce high dry matter yields after warm winters and withstand summer drought spells under Lithuanian conditions. However, mid-to-late-summer heat waves might reduce productivity and should be taken into consideration when breeding new Italian ryegrass cultivars.

The Ongoing Epidemic of West Nile Virus in Greece: The Contribution of Biological Vectors and Reservoirs and the Importance of Climate and Socioeconomic Factors Revisited.

Emerging infectious diseases have inflicted a significant health and socioeconomic burden upon the global population and governments worldwide. West Nile virus, a zoonotic, mosquito-borne flavivirus, was originally isolated in 1937 from a febrile patient in the West Nile Province of Uganda. It remained confined mainly to Africa, the Middle East, and parts of Europe and Australia until 1999, circulating in an enzootic mosquito-bird transmission cycle. Since the beginning of the 21st century, a new, neurotropic, more virulent strain was isolated from human outbreaks initially occurring in North America and later expanding to South and South-eastern Europe. Since 2010, when the first epidemic was recorded in Greece, annual incidence has fluctuated significantly. A variety of environmental, biological and socioeconomic factors have been globally addressed as potential regulators of the anticipated intensity of the annual incidence rate; circulation within the zoonotic reservoirs, recruitment and adaptation of new potent arthropod vectors, average winter and summer temperatures, precipitation during the early summer months, and socioeconomic factors, such as the emergence and progression of urbanization and the development of densely populated areas in association with insufficient health policy measures. This paper presents a review of the biological and socioenvironmental factors influencing the dynamics of the epidemics of West Nile virus (WNV) cases in Greece, one of the highest-ranked European countries in terms of annual incidence. To date, WNV remains an unpredictable opponent as is also the case with other emerging infectious diseases, forcing the National Health systems to develop response strategies, control the number of infections, and shorten the duration of the epidemics, thus minimizing the impact on human and material resources.

The impacts of temperature averages, variabilities and extremes on China’s winter wheat yield and its changing rate

China is the world’s largest producer and consumer of wheat. The impact of temperature averages, variabilities, and extremes on winter wheat yield changes is still not very clear. The annual production data for winter wheat in China’s provinces and municipalities and NCEP-NCAR Reanalysis-1 data were used from November to April in the period 1949–2018, to investigate the impact of temperature-related variables, such as the winter average temperature (), winter variance of temperature (), extreme hot days (EHD), and extreme cold days (ECD), on China’s winter wheat yield. Ensemble Empirical Mode Decomposition (EEMD) analysis showed that winter wheat yield has an in-phase relationship with average temperature but an out-of-phase relationship with variance of temperature, extreme hot days, and extreme cold days on timescales greater than 20 years. The changing rates of winter wheat yield and temperature-related variables were well measured by their sliding trends. At the overwintering growth stage, the increasing rate of average temperature and extreme hot days (temperature variance and extreme cold days) exhibit negative (positive) correlations with the rate of winter wheat yield change, with the strongest correlation observed in southeast China. During the tillering growth stage, the changing rates of average temperature exhibited a positive correlation with the rate of winter wheat yield change, whereas negative associations were observed with temperature variance, extreme hot days, and extreme cold days. Among the regions, Central China showed the weakest correlations. At the reviving growth stage, however, the relationship of changing rates of temperature-related variables with that of winter wheat yield was much weaker. These observational results are important and can be used as a reference in climate models for improving the climatic impacts on the winter wheat yield.

Geographical patterns and determinants in plant reproductive phenology duration.

Biodiversity is and always has been an important issue in ecological research. Biodiversity can reflect niche partitioning among species at several spatial and temporal scales and is generally highest in the tropics. One theory to explain it is that low-latitude tropical ecosystems are dominated by species that are generally only distributed over a narrow area. This principle is known as Rapoport's rule. One previously unconsidered extension of Rapoport's rule may be reproductive phenology, where variation in flowering and fruiting length may reflect a temporal range. Herein, we collected reproductive phenology data for more than 20,000 species covering almost all angiosperm species in China. We used a random forest model to quantify the relative role of seven environmental factors on the duration of reproductive phenology. Our results showed that the duration of reproductive phenology decreased with latitude, although there was no obvious change across longitudes. Latitude explained more of the variation in the duration of flowering and fruiting phases in woody plants than in herbaceous plants. Mean annual temperature and the length of the growing season strongly influenced the phenology of herbaceous plants, and average winter temperature and temperature seasonality were important drivers of woody plant phenology. Our result suggests the flowering period of woody plants is sensitive to temperature seasonality, while it does not influence herbaceous plants. By extending Rapoport's rule to consider the distribution of species in time as well as space, we have provided a novel insight into the mechanisms of maintaining high levels of diversity in low-latitude forests.

Cold homes in Australia: Questioning our assumptions about prevalence

Australia is considered by many to be a warm climate country and hence winter cold and its health effects are often overlooked. The majority of the Australian population live in temperate climate regions, which are heating-dominated and experience cold wintertime conditions. The prevalence of cold in Australian homes has to date been rarely measured or estimated, and the few studies that do are based on proxy data that estimate a low prevalence (around 5 %). This paper tests these proxy measures, using high resolution temperature data on indoor temperature from 100 homes across temperate Australia. The data were assessed using the World Health Organization's Housing and Health guideline for minimum indoor temperature (18 °C), which provides an internationally recognised benchmark for defining cold in homes. Across the sampled homes, 81 % were below 18 °C on average across the whole of winter (June–August 2022). Average winter indoor temperatures were 16.5 ± 2.7 °C across all homes, with no significant difference between locations. These early findings suggest that the problem of unhealthily cold homes in Australia is likely to be significantly more prevalent than previously estimated. Far from affecting 5 % of Australian households, the affected population may be 10 times this value. These initial findings have important implications for how we model health impacts and develop policy. This early release data from a recently commenced large environmental monitoring project is of timely importance. It challenges our understanding of the prevalence of cold housing in Australia context, flagging the pressing need to increase policy attention in advance of winter.

Sıcaklık Değişkenliğinin Afitlerin Yaşam Döngüsüne Etkileri: Dört Örnek Tür

Global warming has great potential to influence all organisms including many animal species, in particular aphids. It has been shown that four aphid species, Cinara cedri, Cinara tujafilina, Metopolophium dirhodum, Pterochloroides persicae, maintained their parthenogenetic generations in Niğde and Artvin Provinces during the winter season in contrast to common life cycles related with cooler and dry conditions. It has been considered that determined aphid species should spend winter season as an overwintering egg as these species mainly show holocyclic life cycles in Niğde and Artvin. Fluctuations in winter average temperature in Niğde and Artvin during last two years enable them to produce more parthenogenetic generations as an indicator of the influences of the temperature fluctuations. These findings are in coincidence with the general approaches that increase in temperature most probably result in more generations in aphid species and in turn let these species to become a severe pest.

지역난방 적용 공동주택의 동절기 급탕 사용패턴과 열손실 분석

In this study, consumption pattern and heat loss of hot water of a 84 m² floor area apartment located in the western region of Seoul using district heating as heat source were analyzed for winter season. Measurement systems for measuring temperatures and flow rates of hot water, indoor and ambient temperature and humidity, temperature and humidity of pipe shaft and heat fluxes of pipe shaft wall were installed and measurements were taken for a whole year from November, 2013 to October, 2014. Measurement results showed that hot water consumption was the highest between 6:00 and 9:00 in the morning and 19:00 and 22:00 in the evening. Average hot water consumption for five months (November-March) in winter season was 14 kWh/house during peak 6 hours, three hours in the morning and three hours in the evening. As a result of analyzing hot water consumption and heat loss rate according to average outdoor temperature in winter, hot water consumption in February was the highest at 15.5 kWh/house during peak 6 hours and heat loss rate was 5.1%. Hot water consumption in November was the lowest at 11.6 kWh/house during peak 6 hours and the heat loss rate was 4.6%.

Enhancing Forecast Skill of Winter Temperature of East Asia Using Teleconnection Patterns Simulated by GloSea5 Seasonal Forecast Model

GloSea5, a seasonal forecast system of the UK Met Office, shows reasonable skill among state-of-the-art operational seasonal forecast systems. However, the average surface temperature (T2m) in winter (December–February) of GloSea5 is particularly low in East Asia. To improve the seasonal forecast skill over East Asia, we focused on the high skill score of global teleconnection patterns simulated by GloSea5. Among the well-predicted teleconnection patterns, we selected those highly correlated with the East Asian T2m: East Atlantic (EA), Polar/Eurasia (PE), East Atlantic/Western Russia (EAWR), and West Pacific (WP) patterns. A multiple linear regression model was constructed using the selected teleconnection indices as predictors. These results are promising. The statistical skill-score evaluation of the constructed linear regression model using the anomaly correlation coefficient (ACC), root mean squared error (RMSE), and mean-squared skill score (MSSS) showed an improvement in the predicted T2m of East Asia, where the values of ACC and MSSS increased by 0.25 and 0.37, respectively, and the RMSE decreased by 0.63 compared to the dynamic forecast model results. These results suggest that a well-designed combined statistical and dynamical approach for seasonal prediction can be beneficial for some regions where the predictability of the dynamic model exhibits a low value.

Efekat godine na morfološka i ornamentalna svojstva stepskog božura

The steppe peony (Paeonia tenuifolia L.) is an endangered medicinal plant species that occurs in Serbia in three habitats, of which the Deliblato Sands is the richest. Based on the results of research conducted at Deliblato Sands in 2023, it was found that the development of the flowering stems of Paeonia tenuifolia was not affected by the slightly higher average winter temperatures. One hundred randomly selected plants were measured in the field, including height, plant girth, number of branches per plant bush, the ratio of flowering to non-flowering branches, shoot-toroot ratio, and stem-to-branch-to-flower ratio. The results showed that the root-to-shoot ratio was 1:2.5, the average height of the tested plants was 41±6 cm, ranging from 30-60 cm, and the girth of the plant bush was 121±30 cm, ranging from 40-170 cm, and was positively correlated with the number of branches. The average number of branches per plant was 8±2.5. Based on the measurement of the absolute dry plant material, it was found that the mass of a branch contained on average 22.5% of the stem, 73.5% of the leaf twigs, and 4% of the flower mass. The petals make up, on average, 34.3% of the mass of the flower.

Modifying impact of environmental factors on the course of an epidemic process

Introduction. It is necessary to establish peculiarities and regularities of COVID-19 infection; this task requires further research on how to formalize and build spatial-temporal models of the infection spread. This article focuses on determining non-infectious factors that can modify the epidemic process caused by the COVID-19 coronavirus for further substantiation of integrated solutions that are necessary to ensure sanitary-epidemiological welfare of the RF population. Materials and methods. Our study involved analyzing regularities of regional differentiation in parameters introduced into mathematical models. These models described how the epidemic process developed in RF regions depending on modifying non-infectious factors identified by modelling the dynamics of spread of SARS-CoV-2 delta strain. These modifying factors included anti-epidemic activities; sanitary-epidemiological, sociodemographic, and economic conditions in a region; weather and climate; public healthcare systems and people’s lifestyles in RF regions over 2020-2021. The dynamics of the epidemic process was modelled by using the conventional SIR-model. Relationships between parameters introduced into the model of the epidemic process and modifying regional conditions were examined by using correlation-regression analysis. Results. The modelling made it possible to identify priority risk factors that modified COVID-19 spread authentically (p&lt;0.05) and explained regional differences in intensity of contagion, recovery and lethality. We established that population coverage with vaccination, especially among people aged 31-40 years, had the greatest authentic positive influence on the decline of reproduction index (R0) of the virus (r=-0.37). An increase in monthly average temperatures in autumn and winter as well as over a year made for people moving faster from the susceptible to infected category (r=0.21-0.22). Growing sun insolation over a year, especially in summer, resulted in slower movement of susceptible people into the infected category (r=-0.02-(-0.23)). Next, several sanitary-epidemiological indicators authentically made the infection spread faster; they were improper working conditions (not conforming to the safety standards as per physical indicators) and ambient air quality in settlement not corresponding to the hygienic standards as per chemical indicators and noise (r=0.29-0.24). Recovery took longer in regions where alcohol consumption was comparatively higher (r=-0.32). Limitations. The limitations of the study include modelling the epidemic process using the standard SIR model; limited set of indicators and period of analysis. Conclusions. The existing regional differentiation in development of specific stages in the epidemic process related to the COVID-19 delta strain occurs due to complex interactions and influence exerted by modifying factors that create a certain multi-level and multi-component system. This system is able to transform the epidemic process either potentiating it or slowing it down.

Effects of long-term average temperature on cardiovascular disease hospitalizations in an American elderly population

BackgroundShort-term exposure to high or low temperatures is associated with increased mortality and morbidity. Less is known about effects of long-term exposure to high or low temperatures. Prolonged exposure to high or low temperatures might contribute to pathophysiological mechanisms, thereby influencing the development of diseases. Our aim was to evaluate associations of long-term temperature exposure with cardiovascular disease (CVD) hospitalizations. MethodsWe constructed an open cohort consisting of all fee-for-service Medicare beneficiaries, aged ≥65, living in the contiguous US from 2000 through 2016 (∼61.6 million individuals). We used data from the 4 km Gridded Surface Meteorological dataset to assess the summer (June–August) and winter (December–February) average daily maximum temperature for each year for each zip code. Cox-equivalent Poisson models were used to estimate associations with first CVD hospitalization, after adjustment for potential confounders. We performed stratified analyses to assess potential effect modification by sex, age, race, Medicaid eligibility and relative humidity. ResultsHigher summer average and lower winter average temperatures were associated with an increased risk of CVD hospitalization. We found a HR of 1.068 (95% CI: 1.063, 1.074) per IQR increase (5.2 °C) for summer average temperature and a HR of 1.022 (95% CI: 1.017, 1.028) per IQR decrease (11.7 °C) for winter average temperature. Positive associations of higher summer average temperatures were strongest for individuals aged <75 years, Medicaid eligible, and White individuals. Positive associations of lower winter average temperatures were strongest for individuals aged <75 years and Black individuals, and individuals living in low relative humidity areas. ConclusionsLiving in areas with high summer average temperatures or low winter average temperatures could increase the risk of CVD hospitalizations. The magnitude of the associations of summer and winter average temperatures differs by demographics and relative humidity levels.