Summer Decline Research Articles

Seasonal variation and demographic characteristics of acute tonsillitis and peritonsillar abscess in ENT practices in Germany (2019-2023).

Peritonsillar abscess (PTA) is a common soft tissue infection of the head and neck. It remains unclear to what extent inflammatory diseases of the palatine tonsils or other infections contribute to the development of PTA. This study examines the demographic characteristics and seasonal variations of acute tonsillitis (aT) and PTA in ENT practices in Germany using a practice database. Retrospective analysis based on data from the German-wide IQVIA™ Disease Analyzer database for the period 2019 to 2023. Data include diagnoses of aT (ICD-10: J03) and PTA (ICD-10: J36) as well as patient demographics (age, sex). Seasonal variations were identified by analysing the monthly diagnosis rates. The Pearson correlation between the monthly case numbers of aT and PTA was determined. 59,934 cases of aT and 5,024 cases of PTA were recorded. The mean age was 30.3 years (aT) and 39.4 years (PTA). The proportion of female patients was 60% (aT) and 49% (PTA). Both diagnoses showed seasonal variations with peaks in winter and spring and a decline in summer, although the decline was less pronounced for PTA. The monthly case numbers of aT and PTA showed high correlations between r = 0.75 (2019) and r = 0.94 (2020). The average correlation for the period 2019-2023 was r = 0.81. During the coronavirus pandemic, a significant decrease in the case numbers of both diseases was observed, while the typical seasonal variations disappeared. After the pandemic, the case numbers increased to higher levels than before the pandemic. aT and PTA both show seasonal variations with peaks in winter and spring and a decline in summer. The correlation between the variations of aT and PTA could be related to a partly common aetiology or to the specific sample of the practice database. The attenuation of seasonal variation during the coronavirus pandemic illustrates the impact of COVID-19 on the incidence of other diseases and on the use of healthcare pathways by patients.

Spatio-Temporal Influence on the Distribution of Forensically Relevant Blowflies (Diptera: Calliphoridae) in Gyeongsangnam-do, South Korea.

The study of blowfly (Diptera: Calliphoridae) biodiversity and distribution is crucial for forensic investigations. Abiotic and biotic factors, such as season and habitat type, have a significant impact on blowfly populations. However, only a few forensic entomology studies have been conducted in South Korea, particularly in the Gyeongsangnam-do region. To address this, an extensive year-long survey was conducted to analyze the compositions, habitat preferences, distribution, and seasonal abundance of forensically relevant blowflies in urban and forested habitats of Gyeongsangnam-do, with sampling conducted twice a month using mouse carcass-baited traps set for 48 h each time. A total of 3470 adult blowflies were recorded, encompassing five genera and 13 species, with a noted absence of specimens during the winter months. The predominant species was Lucilia porphyrina, accounting for 37.2% of the total sample, followed by Chrysomya pinguis (27.6%), Lucilia sericata (7.6%), and Lucilia illustris (7.1%). The species composition was consistent across all surveyed regions; however, seasonal variation in species diversity was evident, with a peak in spring and a decline in summer. Notably, certain species exhibited clear preferences for either urban (Calliphora calliphoroides and L. sericata) or forested habitats (L. porphyrina and Ch. pinguis). This pioneering study elucidates the diverse blowfly communities in Gyeongsangnam-do, highlighting significant seasonal and habitat-dependent variations. These findings enrich our understanding of blowfly ecology in this region, offering valuable insights for forensic applications and underscoring the necessity for ongoing entomological surveillance and research.

Age and sex differences in the annual and seasonal variation of Australia’s suicide rate, 2000–2020

Suicide is a major public health concern both globally and in Australia. But in Australia the extent of substantive annual and seasonality trends since 2000 through the first two decades of the 21st Century, by age and sex, has not been formally reported. The current paper sought to identify annual and within-year (seasonality) trajectories in age-sex standardized suicide rates between 2000 and 2020. The annual and within-year (seasonality) trajectories of suicide were estimated from generalised regression analyses of Australia’s mortality database. No systematic variation in Australia’s suicide rate since 2000 was reported and was consistent between sex and age cohorts. Seasonal variation in rates were identified, with peaks in the new year (January), declines in late Summer/Autumn, stability in Winter, increases in Spring, but with a notable decline in early summer (November–December). These trends were driven men only. Interpretation of current suicide rates need to consider systematic long-term historical context. Despite a historical focus on youth suicide especially, working-aged and very old men have consistently reported higher standardized suicide rates over the first two decades of the 21st Century. Seasonal variation was reported but only reported by men, potentially because across the lifespan, suicide rates for females were a comparatively low incidence event. Particularly after recent successive national and international crises, we emphasise that surveillance and interpretation of current suicide rate requires careful consideration as to the extent any immediate variation may otherwise fall within otherwise normal historical norms.

Quality-controlled meteorological datasets from SIGMA automatic weather stations in northwest Greenland, 2012–2020

Abstract. In situ meteorological data are essential to better understand ongoing environmental changes in the Arctic. Here, we present a dataset of quality-controlled meteorological observations from two automatic weather stations in northwest Greenland from July 2012 to the end of August 2020. The stations were installed in the accumulation area on the Greenland Ice Sheet (SIGMA-A site, 1490 m a.s.l.) and near the equilibrium line of the Qaanaaq Ice Cap (SIGMA-B site, 944 m a.s.l.). We describe the two-step sequence of quality-controlling procedures that we used to create increasingly reliable datasets by masking erroneous data records. Those datasets are archived in the Arctic Data archive System (ADS) (SIGMA-A – https://doi.org/10.17592/001.2022041303, Nishimura et al., 2023f; SIGMA-B – https://doi.org/10.17592/001.2022041306, Nishimura et al., 2023c). We analyzed the resulting 2012–2020 time series of air temperature, surface height, and surface albedo and histograms of longwave radiation (a proxy of cloudiness). We found that surface height increased, and no significant albedo decline in summer was observed at the SIGMA-A site. In contrast, high air temperatures and frequent clear-sky conditions in the summers of 2015, 2019, and 2020 at the SIGMA-B site caused significant albedo and surface lowering. Therefore, it appears that these weather condition differences led to the apparent surface height decrease at the SIGMA-B site but not at the SIGMA-A site. We anticipate that this quality-controlling method and these datasets will aid in climate studies of northwest Greenland and will contribute to the advancement of broader polar climate studies.

Distinct Role of a Spring Atmospheric Circulation Mode in the Arctic Sea Ice Decline in Summer

AbstractA distinguishing feature of Arctic sea ice is the rapid declining in the Pacific Arctic Sector (PAS) in recent years. The atmospheric variability during spring (March‐May) plays a critical role in determining the sea ice extent (SIE) during the following summer. The summertime (June‐August) SIE reduction in the eastern part of PAS, including the East Siberian Sea and the Laptev Sea, is strongly related to the first two leading atmospheric circulation modes in spring, the Arctic Oscillation and the Arctic Dipole, retrieved from empirical orthogonal function analysis. Here, we show that the third leading mode of atmospheric circulation in spring, namely the Barents‐Beaufort Oscillation (BBO), can also change the summer SIE, especially on the western regime of the PAS across the Beaufort and Chukchi Seas. We find that a positive phase of springtime BBO (i.e., BBO+), relative to the BBO−, acts to decrease sea ice thickness via advection and generate sea ice deformation through divergence and shear processes, thereby preconditioning for a rapid sea ice loss within the PAS in the following summer. Furthermore, the occurrence of BBO is state‐dependent and potentially modulated by the phase shift of the Atlantic Multidecadal Oscillation (AMO) and the Pacific Decadal Oscillation (PDO). Since the mid‐1990s, the AMO (PDO) index has changed from a dominant negative (positive) to a positive (negative) phase. These phase shifts in AMO and PDO would have contributed to the subsequently increased appearance of anomalous BBO+ after 2000 and enhanced the summertime sea ice loss in the western regions of the PAS in recent years.

Seasonal evolution of aerosol loading and its vertical distribution in northeastern China from long-term satellite observations and model reanalysis

The vertical structure of aerosols plays an important role in regional air pollution and climate change. Using long-term data on aerosol optical properties obtained through satellite observations (MODIS/Terra, MODIS/Aqua, CALIOP) and reanalysis products (CAMS) during 2007–2021, we analysed the seasonal evolution and vertical distribution of aerosol loading in northeastern China (NEC). We also analysed the seasonal variation trends of aerosol optical depth (AOD) of aerosol species. The AODs during spring and summer were high and distributed in Liaoning (LN) with an average value of approximately 0.6, which was higher in central Jilin and southern Heilongjiang. Sulfate AOD (AOD_SO4) and organic matter AOD (AOD_OM) in NEC were higher during spring and summer (approximately 0.2), and the maximum value of dust AOD (AOD_DU) was approximately 0.1 obtained for western LN. During spring, the aerosol extinction coefficient (AEC) for NEC was high at heights below 2.0 km in LN, and its value was maximum (approximately 0.16 km−1) near the ground in LN during winter. The AEC was concentrated within 0–1 km during winter and higher within 1–3 km during spring and summer in NEC. During 2007–2021, AOD exhibited a decreasing trend, with higher average AOD during spring and summer and lower average AOD during autumn and winter. The seasonal trend of AOD in NEC exhibited a decreasing trend. BC_AOD showed the largest decline in spring, followed by DU_AOD and OM_AOD, and SO4_AOD showed a significant decline in summer. This paper presents accurate information on regional types and vertical distribution of aerosols. This information can be used for model improvement and satellite validation.

Depression and Anxiety on Twitter During the COVID-19 Stay-At-Home Period in 7 Major U.S. Cities

Although surveys are a well-established instrument to capture the population prevalence of mental health at a moment in time, public Twitter is a continuously available data source that can provide a broader window into population mental health. We characterized the relationship between COVID-19 case counts, stay-at-home orders because of COVID-19, and anxiety and depression in 7 major U.S. cities utilizing Twitter data. We collected 18 million Tweets from January to September 2019 (baseline) and 2020 from 7 U.S. cities with large populations and varied COVID-19 response protocols: Atlanta, Chicago, Houston, Los Angeles, Miami, New York, and Phoenix. We applied machine learning‒based language prediction models for depression and anxiety validated in previous work with Twitter data. As an alternative public big data source, we explored Google Trends data using search query frequencies. A qualitative evaluation of trends is presented. Twitter depression and anxiety scores were consistently elevated above their 2019 baselines across all the 7 locations. Twitter depression scores increased during the early phase of the pandemic, with a peak in early summer and a subsequent decline in late summer. The pattern of depression trends was aligned with national COVID-19 case trends rather than with trends in individual states. Anxiety was consistently and steadily elevated throughout the pandemic. Google search trends data showed noisy and inconsistent results. Our study shows the feasibility of using Twitter to capture trends of depression and anxiety during the COVID-19 public health crisis and suggests that social media data can supplement survey data to monitor long-term mental health trends.

Inferring Changes in Arctic Sea Ice through a Spatio-Temporal Logistic Autoregression Fitted to Remote-Sensing Data

Arctic sea ice extent (SIE) has drawn increasing attention from scientists in recent years because of its fast decline in the Boreal summer and early fall. The measurement of SIE is derived from remote sensing data and is both a lagged and leading indicator of climate change. To characterize at a local level the decline in SIE, we use remote-sensing data at 25 km resolution to fit a spatio-temporal logistic autoregressive model of the sea-ice evolution in the Arctic region. The model incorporates last year’s ice/water binary observations at nearby grid cells in an autoregressive manner with autoregressive coefficients that vary both in space and time. Using the model-based estimates of ice/water probabilities in the Arctic region, we propose several graphical summaries to visualize the spatio-temporal changes in Arctic sea ice beyond what can be visualized with the single time series of SIE. In ever-higher latitude bands, we observe a consistently declining temporal trend of sea ice in the early fall. We also observe a clear decline in and contraction of the sea ice’s distribution between 70∘N–75∘N, and of most concern is that this may reflect the future behavior of sea ice at ever-higher latitudes under climate change.

Competing water uses between agriculture and energy: Quantifying future climate change impacts for the Portuguese power sector

Climate change may increase water needs for irrigation in southern Europe competing with other water uses, such as hydropower, which may likely be impacted by lower precipitation. Climate change will also potentially affect the variability and availability of other renewable energy resources (solar and wind) and electricity consumption patterns. This work quantifies the effect of competition for water use between irrigation and hydropower in the future 2050 Portuguese carbon-neutral power sector and under Representative Concentration Pathway 8.5 climate change projections. It uses the power system eTIMES_PT model to assess the combined effects of climate change on the cost-optimal configuration of the power sectorconsidering changes in irrigation, hydropower, wind and solar PV availability. eTIMES_PT is a linear optimisation model that satisfies electricity demand at minimal total power system cost. Results show that, by 2050, climate change can lead to an increase in annual irrigation water needs up to 12% in Tagus and 19% in Douro watersheds (from 2005 values), with substantially higher values for spring (up to 84%). Combining these increased water needs with the expected reduction in river runoff can lead to a decline in summer and spring hydropower capacity factors from half to three times below current values. By 2050, concurrent water uses under climate change can reduce hydropower generation by 26–56% less than historically observed, mainly in summer and spring. Higher solar PV, complemented with batteries’ electricity storage, can offset the lower hydropower availability, but this will lead to higher electricity prices. Adequate transboundary water management agreements and reducing water losses in irrigation systems will play a key role in mitigating climate impacts in both agriculture and power sector.

PSXI-21 Soil emission of carbon dioxide and behavior of microorganisms in soils of Western Kazakhstan

Abstract Kazakhstan Western ecosystems are intensively used in agricultural production. Assessing greenhouse gas emissions from soils, especially CO2, is important. In the upper stages, microbiology, characteristics and condition of the soil change. Biological intensity indicators are soil respiration processes, numerous microbiocenoses species composition. Soil CO2 emissions were measured 5 times monthly during three years. The CO2 flow rate from soil surface is measured by a closed dynamic chamber method with Li-8100A field respirometer. Metagenomic soil testing used bacteria DNA, archaea, real-time PCR, 16SrRNA sequencing. The soil CO2 monthly dynamics fluxes varied among the lands, within the season. In 2020, the CO2 emissions soil peak noted in the pasture. There is a slight decline in summer with a decrease towards the cold season. Comparison between the CO2 flux pasture soils is less in virgin soil. The minimum CO2 flux was recorded in November - February; in the spring, the flux increases. The above CO2 emissions were recorded in summer. In soils, there is wide variety of microorganisms with opposite and incompatible properties for one habitat. The microbial communities structure identified at the family level. The taxonomic samples structure ominated by phylae - Actinobacteria, Proteobacteria, Chloroflexi, Acidobacteria, Gemmatimonadetes, Firmicutes, Actinobacteria. The spread explained by increased actinomycetes resistance characteristic to low moisture content with long dry period. For comparative evaluation microbial communities results comparing by cenoses of upper horizons with dark chestnut soil indicators. This violation caused microorganisms resistance to disturbing factors. On anthropogenically disturbed saline soils, the bacteria found were specific and resistant to critical conditions. CO2 emission in soil varied cenosis type. The CO2 intensity factors were precipitation deficit, high temperature. The profile microorganisms distribution corresponded to the soil horizons humus content. During summer soil drying, the deep soil horizons abundance occurred where moisture is retained.

Analysis of the Atmospheric Water Cycle for the Laurentian Great Lakes Region Using CMIP6 Models

AbstractThis study evaluates the historical climatology and future changes of the atmospheric water cycle for the Laurentian Great Lakes region using 15 models from phase 6 of the Coupled Model Intercomparison Project (CMIP6). While the models have unique seasonal characteristics in the historical (1981–2010) simulations, common patterns emerge in the midcentury SSP2–4.5 scenario (2041–70), including a prevalent shift in the precipitation seasonal cycle with summer drying and wetter winter and spring months, and a ubiquitous increase in the magnitudes of convective precipitation, evapotranspiration, and moisture inflow into the region. The seasonal cycle of moisture flux convergence is amplified (i.e., the magnitude of winter convergence and summer divergence increases), which is the primary driver of future total precipitation changes. The precipitation recycling ratio is also projected to decline in summer and increase in winter by midcentury, signifying a larger contribution of the regional moisture (via evapotranspiration) to total precipitation in the colder months. Most models (10/15) either do not represent the Great Lakes or have major inconsistencies in how the lakes are simulated both in terms of spatial representation and treatment of lake processes. In models with some lake presence, the contribution of lake grid cells to the regional evapotranspiration magnitude can be more than 50% in winter. In the future, winter months have a larger increase in evaporation over water surfaces than the surrounding land, which corroborates past findings of sensitivity of deep lakes to climate warming and highlights the importance of lake representation in these models for reliable regional hydroclimatic assessments.

Evidence for an increasing role of ocean heat in Arctic winter sea ice growth

AbstractWe investigate how sea ice decline in summer and warmer ocean and surface temperatures in winter affect sea ice growth in the Arctic. Sea ice volume changes are estimated from satellite observations during winter from 2002 to 2019 and partitioned into thermodynamic growth and dynamic volume change. Both components are compared to validated sea ice-ocean models forced by reanalysis data to extend observations back to 1980 and to understand the mechanisms that cause the observed trends and variability. We find that a negative feedback driven by the increasing sea ice retreat in summer yields increasing thermodynamic ice growth during winter in the Arctic marginal seas eastward from the Laptev Sea to the Beaufort Sea. However, in the Barents and Kara Seas, this feedback seems to be overpowered by the impact of increasing oceanic heat flux and air temperatures, resulting in negative trends in thermodynamic ice growth of -2 km3month-1yr-1 on average over 2002-2019 derived from satellite observations.

Coronavirus epidemic in Croatia: case fatality decline during summer?

AimTo describe the SARS-CoV-2 epidemic pattern in Croatia during February-September 2020 and compare the case fatality ratio (CFR) between spring and summer.MethodsNational data were used to calculate the weekly and monthly CFRs, stratified by three age groups: 0-64, 65-79, and 80+ years. We also calculated the standardized mortality ratios (SMR) to offset the differences in age composition.ResultsThe epidemic consisted of the initial wave, a trough in June, and two conjoined summer waves, yielding 17 206 coronavirus disease 2019 cases and 290 deaths. While the number of confirmed cases nearly quadrupled during summer, case fatality estimates decreased; CFR in spring was 4.81 (95% confidence interval 3.91-5.71), compared with 1.24 (1.06-1.42) in summer. The SMR for summer was 0.45 (0.37-0.55), suggesting that the case fatality risk halved compared with spring. Cardiovascular comorbidity was an important risk factor for case fatality (SMR 2.63 [2.20-3.13] during spring and 1.28 [1.02-1.59] during summer). The risk of death in ventilated patients remained unchanged (SMR 0.98 [0.77-1.24]).ConclusionsThe epidemic dynamics suggests summer decline in case fatality, except in ventilated patients. While the effect of comorbidity also decreased, cardiovascular comorbidity remained an important risk factor for death even during summer. A plethora of possible confounders and an ever-changing landscape of SARS-CoV-2 epidemic in Croatia require constant monitoring and evaluation, with an aim to prevent the uncontrolled spread of the virus and a disruption of health care functioning.

Seasonal Fluctuation in Intraocular Pressure and Retinal Nerve Fiber Layer Thinning in Primary Open-Angle Glaucoma

To detect seasonal fluctuations in intraocular pressure (IOP) in healthy eyes and eyes with primary open-angle glaucoma (POAG) and to evaluate whether these seasonal fluctuations affect retinal nerve fiber layer (RNFL) thinning in eyes with POAG. Observational, retrospective cohort study. Healthy population who underwent a comprehensive health check-up and patients with POAG using only topical medications were enrolled. Kaplan-Meier survival analysis was used to compare the cumulative incidence probabilities of RNFL thinning between different seasonal IOP fluctuation groups. A Cox proportional hazards model, with adjustments for potential confounding factors, was used to evaluate the association between seasonal fluctuations in IOP and RNFL thinning. Intraocular pressure fluctuation rate calculated from winter and summer IOPs and RNFL thinning as determined by event-based analysis with high-definition OCT. A total of 12 686 healthy eyes and 179 eyes of 179 POAG patients showed a significantly higher IOP in winter than in summer (healthy, 13.2 ± 3.0 mmHg vs. 12.5 ± 2.9 mmHg [P < 0.001]; POAG, 13.1 ± 2.7 mmHg vs. 11.8 ± 2.3 mmHg [P < 0.001]). In POAG patients, the mean age at initial OCT and follow-up duration were 55.1± 11.7 years and 98.4 ± 26.4 months, respectively. The mean deviation (MD) at first visit, MD slope, and RNFL thinning rate were -2.2 ± 3.4 dB, -0.07 ± 0.44 dB/year, and -0.44 ± 0.88 μm/year, respectively. During the study period, 85 eyes (47.5%) showed RNFL thinning progression. Kaplan-Meier analysis showed that a high seasonal IOP fluctuation rate significantly suppressed RNFL thinning (P < 0.05, log-rank test). After adjusting for confounders in the Cox analysis, the seasonal IOP fluctuation rate still showed a significantly negative association with RNFL thinning (hazard ratio, 0.98; 95% confidence interval, 0.96-0.99; P= 0.005). Winter IOP was higher than summer IOP in both healthy and POAG eyes. The temporary IOP decline in summer, rather than a constant IOP throughout the year, may prevent glaucoma progression.

Influence of Potamogeton crispus on Lake Water Environment and Phytoplankton Community Structure

The decomposition of submerged macrophytes is generally associated with dramatic changes in the water environment, such as the large release of nutrients (e.g., nitrogen and phosphorus) and organic carbon to the surrounding waters, which may result in significant changes in phytoplankton community structure. In this study, Potamogeton crispus, physicochemical variables, and phytoplankton samples were collected in 14 shallow lakes in the middle and lower Jianghuai Plain in spring (growing period of P. crispus) and summer (decomposition phase of P. crispus) of 2018. The effects of the decline of P. crispus on water quality and phytoplankton community structure were quantified. The results showed that water transparency increased significantly in spring because the growth of P. crispus inhibits sediment resuspension and macrophytes can transport the nutrients from the water column to the sediment. The values of dissolved oxygen and pH also increased significantly due the photosynthesis by macrophytes. In contrast, the decomposition of P. crispus during summer months caused a significant increase in water turbidity and organic matter. There were considerable differences in phytoplankton biomass and cyanobacterial biomass in the sites with or without P. crispus, and the corresponding ratios of cyanobacterial biomass to the total algal biomass were 18.96% and 34.05%, respectively. Higher values of cyanobacterial biomass were observed with the decomposition of P. crispus than its counterpart in summer because ① the decomposition of macrophytes provided sufficient organic matter and nutrient (nitrogen and phosphorus) resources for cyanobacterial growth; ② P. crispus decline in summer significantly increased water turbidity, which makes cyanobacteria occupy a better ecological niche and more efficiently utilize nitrogen and phosphorus.

Creeping bentgrass summer decline as influenced by climatic conditions and cultural practices

AbstractDespite its popularity as a putting surface in North Carolina, creeping bentgrass (Agrostsis stolonifera L.) is highly susceptible to summer bentgrass decline (SBD) during hot summer months. Cultural practices have been shown to help alleviate the pressure of SBD. The objectives of this study were to detail the impacts of N fertility, soil water content, and hollow‐ and solid‐tine cultivation on creeping bentgrass quality. Cultural treatments included four N rates (97, 195, 293, and 391 kg ha−1 yr−1), four hollow‐tine core cultivation programs (6.4 mm diam. tines two times yr−1, 9.5 mm diam. tines two and three times yr−1, and a non‐cored control), two soil water content levels (low and high), and two summer solid‐tine spiking cultivation treatments (spiked and not spiked). Visual turfgrass quality was measured. A N rate greater than 195 kg ha−1 was needed to maintain acceptable turfgrass quality. High soil water content consistently provided better summer turfgrass quality compared to low soil water content conditions. Nitrogen fertility and soil water content interacted where higher levels of both resulted in the best quality ratings. Hollow‐core cultivation reduced turfgrass quality at the lower N rates; whereas, solid‐tine spiking had no effect on turfgrass quality. Although weather plays a large role in SBD in North Carolina, results from this study show that cultural practices can influence its severity.

Fast Warming Has Accelerated Snow Cover Loss during Spring and Summer across the Northern Hemisphere over the Past 52 Years (1967–2018)

With snow cover changing worldwide in several worrisome ways, it is imperative to determine both the variability in snow cover in greater detail and its relationship with ongoing climate change. Here, we used the satellite-based snow cover extent (SCE) dataset of National Oceanic and Atmospheric Administration (NOAA) to detect SCE variability and its linkages to climate over the 1967–2018 periods across the Northern Hemisphere (NH). Interannually, the time series of SCE across the NH reveal a substantial decline in both spring and summer (−0.54 and −0.71 million km2/decade, respectively), and this decreasing trend corresponded with rising spring and summer temperatures over high-latitude NH regions. Among the four seasons, the temperature rise over the NH was the highest in winter (0.39 °C/decade, p &lt; 0.01). More precipitation in winter was closely related to an increase of winter SCE in mid-latitude areas of NH. Summer precipitation over the NH increased at a significant rate (1.1 mm/decade, p &lt; 0.01), which likely contribute to the accelerated reduction of summer’s SCE across the NH. However, seasonal sensitivity of SCE to temperature changes differed between the Eurasian and North American continents. Thus, this study provides a better understanding of seasonal SCE variability and climatic changes that occurred at regional and hemispheric spatial scales in the past 52 years.

Seasonal variation in blood pressure: Evidence, consensus and recommendations for clinical practice. Consensus statement by the European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability.

: Blood pressure (BP) exhibits seasonal variation with lower levels at higher environmental temperatures and higher at lower temperatures. This is a global phenomenon affecting both sexes, all age groups, normotensive individuals, and hypertensive patients. In treated hypertensive patients it may result in excessive BP decline in summer, or rise in winter, possibly deserving treatment modification. This Consensus Statement by the European Society of Hypertension Working Group on BP Monitoring and Cardiovascular Variability provides a review of the evidence on the seasonal BP variation regarding its epidemiology, pathophysiology, relevance, magnitude, and the findings using different measurement methods. Consensus recommendations are provided for health professionals on how to evaluate the seasonal BP changes in treated hypertensive patients and when treatment modification might be justified. (i) In treated hypertensive patients symptoms appearing with temperature rise and suggesting overtreatment must be investigated for possible excessive BP drop due to seasonal variation. On the other hand, a BP rise during cold weather, might be due to seasonal variation. (ii) The seasonal BP changes should be confirmed by repeated office measurements; preferably with home or ambulatory BP monitoring. Other reasons for BP change must be excluded. (iii) Similar issues might appear in people traveling from cold to hot places, or the reverse. (iv) BP levels below the recommended treatment goal should be considered for possible down-titration, particularly if there are symptoms suggesting overtreatment. SBP less than 110 mmHg requires consideration for treatment down-titration, even in asymptomatic patients. Further research is needed on the optimal management of the seasonal BP changes.

Seasonality in acute promyelocytic leukemia: Fact or myth?

BACKGROUND: Acute promyelocytic leukemia (APL) is a biologically and clinically distinct subtype of acute myeloid leukemia (AML) Etiological and seasonal factors that play a role in APL still unclear.OBJECTIVES: The aim of the study was to retrospectively evaluate the available data to assess the impact of seasonal variations on incidence of APL over a period of 6 years.PATIENTS AND METHODS: A retrospective, observational study based on APL record of a Hematology Nasiriyah Center from January 2014 to January 2020 was processed. The collected data of diagnosed (APL) patients at this center for 6 years was analyzed, and APL presenting in each month of the year was also assessed for any evidence of seasonality.RESULTS: Fifty-eight cases of APL were included in this study: there were 22 males (37.93%) and 36 females (62.07%). The mean age was 31.1 ± 14.4 years (minimum 15 and maximum 67). We found a pronounced peak of APL occurrence in March (within winter and early spring months) and decline in summer to zero point in August, which was repeated periodical all studied 6 years.CONCLUSIONS: Seasonal pattern of APL was observed. Investigation of specific seasonal risk factors would be informative in explaining the etiology behind the observed variation.

Relationship between seasonal variations of primary production, abiotic factors and phytoplankton composition in the coastal zone of the south-eastern part of the Baltic Sea

Seasonal variations in marine primary production (PP) in the coastal zone of the south-eastern part of the Baltic Sea were studied between April 2008 and April 2009. The spring PP maximum was observed to be limited by the concentration of nitrates. Following a decrease in photosynthetic consumption of nutrients, an increase in ammoniacal nitrogen due to the decomposition of organic matter and concomitant increase in the biomass of diazotrophic cyanobacterial species, the growth of phytoplankton was limited by phosphates. By the middle of summer, concentrations of nitrate and phosphates had reached the analytical minimum (0.07 mmol m −3 and 0.06 mmol m−3, respectively). Terrestrial runoff, whose maximum occurred during the spring–summer decline of phytoplankton growth, had a moderately positive influence on PP, with the annual rate reaching the eutrophic level (290 g C m−2 yr−1); however, the seasonal cycle was typical for mesotrophic waters of temperate latitudes of the Northern Hemisphere. The most significant producers of phytoplankton biomass (PB) were representatives of the Dinophyta, Chlorophyta and Cyanophyta systematic divisions at the study site. 77% of carbon-to-chlorophyll a ratio variability was determined by the seasonal variations in green algae biomass. During the spring bloom, dinoflagellates provided the highest contribution in the total biomass in comparison with diatoms.