Variation In Seasonality Research Articles

Understanding the local-level variations in seasonality of human respiratory syncytial virus infection: a systematic analysis

BackgroundWhile previous reports characterised global and regional variations in RSV seasonality, less is known about local variations in RSV seasonal characteristics. This study aimed to understand the local-level variations in RSV seasonality and to explore the role of geographical, meteorological, and socio-demographic factors in explaining these variations.MethodsWe conducted a systematic literature review to identify published studies reporting data on local-level RSV season onset, offset, or duration for at least two local sites. In addition, we included three datasets of RSV activity from Japan, Spain, and Scotland with available site-specific data. RSV season onset, offset, and duration were defined using the annual cumulative proportion method. We estimated between-site variations within a region using the earliest onset, the earliest offset, and the shortest duration of RSV season of that region as the references and synthesised the variations across regions by a multi-level mixed-effects meta-analysis. Using the three datasets from Japan, Spain and Scotland, we applied linear regression models with clustered standard errors to explore the association of geographical, meteorological, and socio-demographic factors with the season onset and offset, respectively.ResultsWe included 7 published studies identified from the systematic literature search. With the additional 3 datasets, these data sources covered 888,447 RSV-positive cases from 101 local study sites during 1995 to 2020. Local-level variations in RSV season within a region were estimated to be 6 weeks (41 days, 95% CI: 25–57) for season onset, 5 weeks (32 days, 13–50) for season offset, and 6 weeks (40 days, 20–59) for season duration, with substantial differences across years. Multiple factors, such as temperature, relative humidity, wind speed, annual household income, population size, latitude, and longitude, could jointly explain 66% to 84% and 35% to 49% of the variations in season onset and offset, respectively, although their individual effects varied by individual regions.ConclusionsLocal-level variations in RSV season onset could be as much as 6 weeks, which could be influenced by meteorological, geographical, and socio-demographic factors. The reported variations in this study could have important implications for local-level healthcare resources planning and immunisation strategy.Trial registrationPROSPERO CRD42023482432.

Counteracting greenhouse gas and aerosol influences intensify global water seasonality over the past century

Variations in water availability seasonality significantly impact society and ecosystems. While many studies have focused on mean or extreme precipitation, the response of water availability seasonality, influencing yearly water distribution beyond individual extremes, to human-induced climate change remains underexplored. Here we examine global and regional water availability seasonality changes from 1915 to 2014, quantifying how anthropogenic greenhouse gases and aerosols have influenced these variations using reanalysis and simulations from Coupled Model Intercomparison Project Phase 6. Despite large spatiotemporal uncertainties due to regional variability and model assumptions, we find that greenhouse gases significantly amplify the seasonality, while aerosols reduce it. Given that the positive effects of greenhouse gases surpass the aerosols’ negative effects, the counterbalancing influences have led to an overall enhancement in seasonality of water availability over the past century. This trend is expected to continue in the future as greenhouse gases-induced warming continues to rise and aerosol levels decline.

Factors influencing the presence and relative abundance of Didymosphenia geminata: impact on the composition of diatom assemblages over a broad latitudinal gradient in Chilean rivers

This study explored the abiotic factors influencing Didymosphenia geminata blooms and the combined effect of D. geminata and abiotic factors on local diatom assemblages in 13 Chilean watersheds across a broad latitudinal range (37°–47° S). To understand the multi-scale drivers, we used generalized linear mixed-effects models to assess the abiotic factors most influential on D. geminata presence and relative abundance. We then explored the effects of D. geminata and abiotic factors on the α- and β-diversity of diatom assemblages using generalized linear models and permutational analyses of variance, respectively. Three watersheds lacked D. geminata and another three had low relative abundance. Seasonally, the relative abundance of D. geminata was significantly higher in spring than in autumn. We found positive correlations between elevation, river order, pH and D. geminata presence and relative abundance, while water temperature was negatively correlated with D. geminata relative abundance. Diversity indices were significantly influenced by watershed and to a lower extent by the presence of D. geminata. We found significant spatial (i.e. between watersheds along a south–north latitudinal gradient) and temporal (i.e. between seasons) variations in β-diversity of diatom assemblages. Moreover, increasing relative abundance of D. geminata in the assemblage was correlated with lower diatom diversity. In addition, the compositions of diatom assemblages with D. geminata were more alike and less variable than those in non-invaded sites. This study is a first attempt to understand the multi-scale drivers of diatom assemblages in Chilean lotic ecosystems.

Risk assessment of potential toxic metals in soils based on children’s blood lead levels: Seasonable variations and Monte Carlo simulations

Risk assessment of potential toxic metals in soils based on children’s blood lead levels: Seasonable variations and Monte Carlo simulations

Complexity and Variation in Infectious Disease Birth Cohorts: Findings from HIV+ Medicare and Medicaid Beneficiaries, 1999-2020.

The impact of uncertainty in information systems is difficult to assess, especially when drawing conclusions from human observation records. In this study, we investigate survival variation in a population experiencing infectious disease as a proxy to investigate uncertainty problems. Using Centers for Medicare and Medicaid Services claims, we discovered 1,543,041 HIV+ persons, 363,425 of whom were observed dying from all-cause mortality. Once aggregated by HIV status, year of birth and year of death, Age-Period-Cohort disambiguation and regression models were constructed to produce explanations of variance in survival. We used Age-Period-Cohort as an alternative method to work around under-observed features of uncertainty like infection transmission, receiver host dynamics or comorbidity noise impacting survival variation. We detected ages that have a consistent, disproportionate share of deaths independent of study year or year of birth. Variation in seasonality of mortality appeared stable in regression models; in turn, HIV cases in the United States do not have a survival gain when uncertainty is uncontrolled for. Given the information complexity issues under observed exposure and transmission, studies of infectious diseases should either include robust decedent cases, observe transmission physics or avoid drawing conclusions about survival from human observation records.

Sustaining Soil Biological Activity: The Role of Extended Reduced and No-Tillage Techniques

Soil management techniques can have varying effects on various soil properties. This study investigated the impact of various tillage techniques on soil properties for 14 years. The experiment was conducted at the Çukurova University Research Station, located in a region with a dominant Mediterranean climate. The research aimed to assess the changes in soil organic matter (SOM) content, soil respiration (SR), dehydrogenase enzyme activity (DHA), and soil temperature (ST) under seven different long-term tillage practices. The results revealed significant increases (p ≤ 0.05) in SOM (17-115%), SR (19-37%), and DHA (63-142%), under conservation tillage compared to conventional tillage practices. Additionally, conventional tillage with stubble burned consistently had the lowest values across all measured properties. Seasons variations also significantly (p≤0.05) affected the observed values. These findings suggest that conventional tillage practices have a negative effect on the analyzed biological activities, with stubble burning further exacerbating this impact. Further research exploring the long-term effects of different tillage practices under varying crop rotations and soil conditions can contribute to the sustainable development of agricultural production in the region.

Underappreciated roles of soil nitrogen oxide emissions on global acute health burden

The recognized importance of ambient fine particulate matter (PM2.5), ozone (O3), and nitrogen dioxide (NO2) on human health has prompted the world to enact increasingly strict regulations on anthropogenic nitrogen oxides (NOx) emissions. However, the health concerns from soil NOx, potentially driven by fertilizer input but conventionally categorized as natural sources, remain less studied. Here, we emphasize the underappreciated roles of soil NOx emissions on health burden attributable to short-term PM2.5, O3, and NO2 exposure. Globally, we quantify acute health effects using machine-learning-based daily exposure estimates and identify influences of soil NOx emissions based on chemical transport model simulations. We find that 72.3% of the globe is affected by soil NOx emissions, whose contributions to short-term PM2.5, O3, and NO2 pollution lead to 13.9 (95% Confidence Interval [CI]: 9.1–18.8), 26.0 (18.2–34.2), and 13.9 (10.3–17.5) thousand premature mortality, respectively, in 2019. With distinct variations in regions, seasons, and pollutants, soil NOx-originated air pollution poses a global health concern, particularly for developing regions and intensively agricultural areas. In response to the intensive fertilizer use, South Asia, Southern Sub-Saharan Africa, and Central Europe witness the largest soil NOx-related health burden of up to 1.6 (95% CI: 1.1–2.1) mortality per 100k population. The overall health risk peaks in May, with O3 pollution typically dominating the soil NOx-attributable health burden during warm seasons and NO2 or PM2.5 during cold months. Our study highlights the necessity of dynamically adapted agricultural strategies for health-oriented multi-pollutant control, among which the improved use of synthetic fertilizers deserves priority under the ever-changing climate.

Effects of Tin Mining on Water Sources in Mwerasandu Tin Mine, Ntungamo District, Uganda

Tin mining is a widespread economic activity across various regions worldwide. Understanding the consequences of such operations is crucial for sustainable water management and environmental conservation. The current study aimed at determining the concentrations tin, lead and mercury in the water sources of Nyakahiimbura Stream in Mwerasandu, and assessed the physico-chemical properties including pH, turbidity, and chemical oxygen demand (COD) of the water from the Nyamuhimbura stream, Ntungamo district. Water samples from three locations, that is; the upstream, impact area and downstream of the Nyakahiimbura water stream were collected during the dry and wet seasons of the year 2024. The samples collected were analyzed for the physico-chemical properties in the laboratory while the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP – OES) was used to determine the concentration of heavy metals in the water samples. The pH, COD values obtained were within the acceptable effluent standards while the turbidity values at the upstream and downstream of the dry season and downstream during the wet season were above the acceptable effluent Standards. The tin concentration was high in the dry season (0.09mg/L) as compared to concentration (0.118mg/L) in the wet season. Lead concentration was the same (0.015mg/L) in both seasons. The concentrations of the heavy metals showed some variations in both dry and wet seasons in the upstream, impacted area and the downstream of the study area as compared to the values of the effluent standards. The study recommends that alternative sources of water for domestic use should be sought of. Also, the government officials especially from the Ministry of Health should carry out awareness campaigns to members of the community about the health risks associated with the uptake of the contaminated waters for domestic purposes. Constructed wetlands should be in place around the mining sites to act as filters for the dangerous metals before the water enters the surrounding environment.

Sexual activity and climatic adaptation assessment of West African Dwarf goats introduced into Algeria

This study aimed to highlight the effects of variations in age, seasons and climatic conditions on the reproductive activity of West African Dwarf Goats imported from tropical zones in Algeria, and to verify the degree of their adaptation to Mediterranean climatic conditions. For this purpose, testicular biometry and hormonal analysis (testosterone and LH levels) using the radioimmunological method were carried out monthly. In total, seven goats aged between 18 to 48+ months were surveyed during the period from September 2021 to March 2022. The results showed a considerable effect of age on testicular measurements. Bucks less than 18 months recorded the lowest average testicular length, width, thickness and volume, scrotal width and circumference, as levels of testosterone concentrations. All variables were strong correlated. Seasonal variations in the average testicular measurements and hormonal concentrations were observed, without affecting testicular activity. Apart from thenegative action of ambient temperature, no effects of relative humidity or atmospheric pressure were revealed. West African Dwarf Goats showed a good capacity to adapt to Mediterranean climatic conditions through their continuous testicular activity during the year.

Disentangling seasonal and annual precipitation signals in the tropics over the Holocene: Insights from δD, alkanes and GDGTs

Rainfall seasonality in the tropics has a substantial impact on both ecosystems and human livelihoods. Yet, reconstructions of past rainfall variability have so far generally been unable to differentiate between annual and seasonal precipitation changes. Past variations in seasonality are therefore largely unknown. Here, we disentangle hydrogen isotopic (δD) signals from terrestrial leaf waxes and algae in an 8000-year peat core from Sumatra, which reflect annual versus wet season rainfall signals, respectively. We validate these results using lipid biomarkers by reconstructing vegetation dynamics via n-alkane distributions and peatland hydrological conditions using glycerol dialkyl glycerol tetraethers (GDGTs), as well as biomass burning using levoglucosan concentrations in the core. Finally, we compare our proxy results to a transient climate model simulation (MPI-ESM1.2) to identify the mechanism for seasonality changes. We find that algal δD indicates stronger Indonesian-Australian Summer Monsoon (IASM) precipitation in the Mid-Holocene, between 8 and 4.2 cal ka BP. A period of alternating flooding, droughts and wildfires is reconstructed between 6 and 4.2 cal ka BP, implicating very strong monsoonal precipitation and drying out and burning during a longer and intensified dry season. We attribute this strong rainfall seasonality in the Mid-Holocene mainly to orbitally forced insolation seasonality and a strengthened IASM, consistent with the modeling results. In terms of annual rainfall, terrestrial plant δD, vegetation composition and GDGTs all indicate wetter conditions peaking between 3 and 4.5 cal ka BP, preceded by drier conditions, followed by drastic and rapid drying in the late Holocene from around 2.8 cal ka BP. Our multiproxy annual precipitation reconstruction thereby indicates the wettest overall conditions approximately 1500–2000 years later than a nearby speleothem δ18O record, which instead follows the seasonally biased algal δD in our record. We, therefore, hypothesize that speleothem reconstructions over the Holocene in parts of the tropics with low but significant seasonality may carry a stronger seasonal component than previously suggested. The data presented here contribute with new insights on how isotopic rainfall proxies in the tropics can be interpreted. Our findings resolve the seasonal versus annual components of Holocene rainfall variability in the Indo-Pacific Warm Pool region, highlighting the importance of considering seasonality in rainfall reconstructions.

Carbon and nitrogen sources in tropical coastal lagoon food webs under variable hydrological conditions

Whilst the impact of continental and marine nutrient sources on the ecological functioning of coastal food webs is well investigated in temperate regions, tropical ecosystems remain less well understood, in particular coastal lagoons. In this study, the sources of carbon and nitrogen in a coastal lagoon system in the southeast of Madagascar are traced using stable isotopes of carbon (δ13C) and nitrogen (δ15N). Three interconnected coastal lagoons with different degree of river influence and eutrophication are investigated. Their food webs are assessed with respect to spatial and seasonal (wet and dry seasons) variations in lagoon water conditions, as well as with respect to the sources of nutrients and organic matters. Results show that river input is the main source of NO3−, and that NO3− supply is significantly higher during the wet season. In contrast, NH4+ is produced internally in the lagoon, and concentrations are higher during the dry season. A lower δ13C value observed in particulate organic matter (POM; proxy of phytoplankton) indicates terrestrial-riverine carbon inputs, which generally have low δ13C values. During the dry season, exceptionally high δ15N values of lagoon POM suggest the uptake of newly produced lagoon water NH4+ and/or the 15N enrichment of lagoon POM pool due to mineralization, resulting in 15N enrichment in consumers. Moreover, δ13C and δ15N values of consumers (fishes and invertebrates) reflect predominantly those of lagoon POM and sediment organic matter (SOM), suggesting that consumers primarily depend on lagoon POM and SOM as sources of carbon and nitrogen. The δ15N values in consumers further indicate that some species feed on more than one trophic level, suggesting flexible foraging strategy of consumers as a function of food source availability. This study demonstrates the roles of both river inflow and sediment in supplying carbon and nitrogen to a coastal lagoon food web, documenting the ecological implications of seasonal variations in lagoon hydrological conditions.

Evidence for seasonal migration by a cryptic top predator of the deep sea

BackgroundIn ecosystems influenced by strong seasonal variation in insolation, the fitness of diverse taxa depends on seasonal movements to track resources along latitudinal or elevational gradients. Deep pelagic ecosystems, where sunlight is extremely limited, represent Earth’s largest habitable space and yet ecosystem phenology and effective animal movement strategies in these systems are little understood. Sperm whales (Physeter macrocephalus) provide a valuable acoustic window into this world: the echolocation clicks they produce while foraging in the deep sea are the loudest known biological sounds on Earth and convey detailed information about their behavior.MethodsWe analyze seven years of continuous passive acoustic observations from the Central California Current System, using automated methods to identify both presence and demographic information from sperm whale echolocation clicks. By integrating empirical results with individual-level movement simulations, we test hypotheses about the movement strategies underlying sperm whales’ long-distance movements in the Northeast Pacific.ResultsWe detect foraging sperm whales of all demographic groups year-round in the Central California Current System, but also identify significant seasonality in frequency of presence. Among several previously hypothesized movement strategies for this population, empirical acoustic observations most closely match simulated results from a population undertaking a “seasonal resource-tracking migration”, in which individuals move to track moderate seasonal-latitudinal variation in resource availability.DiscussionOur findings provide evidence for seasonal movements in this cryptic top predator of the deep sea. We posit that these seasonal movements are likely driven by tracking of deep-sea resources, based on several lines of evidence: (1) seasonal-latitudinal patterns in foraging sperm whale detection across the Northeast Pacific; (2) lack of demographic variation in seasonality of presence; and (3) the match between simulations of seasonal resource-tracking migration and empirical results. We show that sperm whales likely track oceanographic seasonality in a manner similar to many surface ocean predators, but with dampened seasonal-latitudinal movement patterns. These findings shed light on the drivers of sperm whales’ long-distance movements and the shrouded phenology of the deep-sea ecosystems in which they forage.

Flow-weighted sourcing of freshwater runoff from Pacific-draining continental and coastal basins in south-western Patagonia (41-56° S): characterizing regional inputs to Chilean fjords

Global estimates of the supply of dissolved and suspended materials to the ocean, in order to be relevant at either political or ecological scales, belie a finer-scale analysis necessary for understanding specific terrestrial-marine interactions. This is especially true for continental runoff to the marine critical zone of inland fjords and channels, where mechanisms, drivers, and predictions need to be elaborated in the context of changing land use and shifting climate forcing. In fjords in south-western Patagonia, runoff from small coastal and large continental basins (~310 x103 km2), sourced from a diverse geography and wide climatic gradient (<150 – 6,000+ mm/year), correspond with a very low density of hydrological and water quality observations. Based on the recently developed regional runoff model (FLOW), we estimated the coastal freshwater discharges and characterized flow-weighted sourcing (land use-cover type, climate, glaciers/geology, and soil province) for Pacific drainages from 41° to 56° south latitude. An estimated 692 km3/year (mean across 1979-2018), or 2% of worldwide total, is more than 85% of previous estimates for the much larger Pacific South American input. Based on limited water quality observations and inference from runoff sourcing, we predict general patterns of export for four groups of continental resources important for marine productivity, including: significant regional variation in flow seasonality, a N-S gradient in declining input of silicic acid and increased glacial input of sediment and iron, and potential shift in dissolved organic matter input sources from rainforest (potentially labile) to peatlands (refractory). Finally, we emphasize the temporal and spatial consequences of near-reference condition river runoff for marine ecosystem productivity and function in the Patagonian fjords, with specific recommendations for water quality standards and sustained monitoring for coupled river and marine ecosystems.

Detection of functional diversity gradients and their geoclimatic filters is sensitive to data types (occurrence vs. abundance) and spatial scales (sites vs. regions)

Functional diversity (FD) reflects within- and between-site variation of species traits (α- and β-FD, respectively). Understanding how much data types (occurrence-based vs. abundance-weighted) and spatial scales (sites vs. regions) change FD and ultimately interfere with the detection of underlying geoclimatic filters is still debated. To contribute to this debate, we explored the occurrence of 1690 species in 690 sites, abundances of 1198 species in 343 sites, and seven functional traits of the Atlantic Forest woody flora in South America. All FD indices were sensitive and dependent on the data type at both scales, with occurrence particularly increasing α richness and dispersion (occurrence > abundance in 80% of the sites) while abundance increased β total, β replacement, and α evenness (abundance > occurrence in 60% of the sites). Furthermore, detecting the effect of geoclimatic filters depended on the data type and was scale-dependent. At the site scale, precipitation seasonality and soil depth had weak effects on α- and β-FD (max. R2 = 0.11). However, regional-scale patterns of α richness, dispersion, and evenness strongly mirrored the variation in precipitation seasonality, soil depth, forest stability over the last 120 kyr, and cation exchange capacity (correlations > 0.80), suggesting that geoclimatic filters manifest stronger effects at the regional scale. Also, the role of edaphic gradients expands the idea of biogeographical filters beyond climate. Our findings caution functional biogeographic studies to consider the effect of data type and spatial scale before designing and reaching ecological conclusions about the complex nature of FD.

Impact of captivity and natural habitats on gut microbiome in Epinephelus akaara across seasons

BackgroundThe gut microbiota significantly influences the health and growth of red-spotted grouper (Epinephelus akaara), a well-known commercial marine fish from Fujian Province in southern China. However, variations in survival strategies and seasons can impact the stability of gut microbiota data, rendering it inaccurate in reflecting the state of gut microbiota. Which impedes the effective enhancement of aquaculture health through a nuanced understanding of gut microbiota. Inspired by this, we conducted a comprehensive analysis of the gut microbiota of wild and captive E. akaara in four seasons.ResultsSeventy-two E. akaara samples were collected from wild and captive populations in Dongshan city, during four different seasons. Four sections of the gut were collected to obtain comprehensive information on the gut microbial composition and sequenced using 16S rRNA next-generation Illumina MiSeq. We observed the highest gut microbial diversity in both captive and wild E. akaara during the winter season, and identified strong correlations with water temperature using Mantel analysis. Compared to wild E. akaara, we found a more complex microbial network in captive E. akaara, as evidenced by increased abundance of Bacillaceae, Moraxellaceae and Enterobacteriaceae. In contrast, Vibrionaceae, Clostridiaceae, Flavobacteriaceae and Rhodobacteraceae were found to be more active in wild E. akaara. However, some core microorganisms, such as Firmicutes and Photobacterium, showed similar distribution patterns in both wild and captive groups. Moreover, we found the common community composition and distribution characteristics of top 10 core microbes from foregut to hindgut in E. akaara.ConclusionsCollectively, the study provides relatively more comprehensive description of the gut microbiota in E. akaara, taking into account survival strategies and temporal dimensions, which yields valuable insights into the gut microbiota of E. akaara and provides a valuable reference to its aquaculture.

Analysis of trends and abrupt changes in groundwater and meteorological droughts in the United Kingdom

In recent years, the escalating impact of climate change, coupled with growing concerns regarding groundwater drought, has underscored the critical importance of analyzing hydrological trends. This is a foundational step in advancing effective water resource planning and management. This study presents a regional investigation of groundwater and meteorological droughts in the UK, utilizing the Standardized Groundwater Index (SGI) and the Standardized Precipitation Index (SPI). The analysis encompasses drought duration and an evaluation of the correlation between the SGI and SPI. Subsequently, the seasonal Mann-Kendall (MK) test and the Bayesian Changepoint Detection and Time Series Decomposition (BEAST) algorithm were employed to assess overall trends for both SGI and SPI. Additionally, these methods were utilized to pinpoint trend and seasonal abrupt changes within the time series of both indices.The seasonal MK test revealed statistically significant trends in many SGI stations across the UK, spanning from Northern Scotland down to the South of England, encompassing both increasing and decreasing trends. Additionally, the MK test showed slightly positive trends at the low SPI time scale, though these were not statistically significant. In contrast, more consistent and significant increasing trends were observed throughout the entire UK, except for Northern Scotland, which exhibited negative trends. Despite indications of a progressively more humid UK, the BEAST analysis enabled the detection of decreasing abrupt changes in trends. These changes result in sudden transitions from wet to dry conditions, which can be challenging to identify using the MK test alone. However, BEAST revealed both positive and negative abrupt changes across the entire UK, as well as positive or negative variations in seasonality. This suggests a high degree of variability in seasonal patterns. In summary, this study provides a detailed assessment of groundwater and meteorological drought trends and abrupt changes, considering the impact of climate change on various regions of the UK.

Influence of spatiotemporal and meteorological variation on Norwegian atmospheric pollen seasonality

Climate change is and will continue to alter plant responses to their environment. This is especially prominent concerning the adaptive tracking in reproductive phenology. For wind pollinated plants, this will substantially influence their pollen seasonality, yet there are gaps in knowledge about how environmental variation influences pollen seasonality. To investigate this, we monitored daily atmospheric pollen concentrations of seven pollen types from ecologically, economically and allergenically important plants (alder, hazel, willow, birch, pine, grass and mugwort) in twelve Norwegian locations spanning the entire country for up to 28 years. Six daily meteorological variables (maximum temperature, precipitation, wind speed, relative humidity, solar radiation and atmospheric pressure) was obtained from the MET Nordic dataset with full data cover. The pollen seasonality was then modelled using four spatial, three temporal and the six meteorological variables in a generalized linear model approach with a negative binomial distribution to investigate how each variable group thematically and individually contribute to variation in pollen seasonality. We found that the full models explained the most variation, ranging from R2 = 20.3 % to 59.5 %. The models were also highly accurate, being able to predict 54.5 % to 99.1 % of daily pollen concentrations to within 20.1 pollen grains/m3. Overall, the temporal variables were able to explain more variation than spatial and meteorological variables for most pollen types. Month, altitude and maximum temperature were the most important single variables for each category. The importance of each variable could be traced back to their individual effects of reproductive phenology, plant metabolism, species distributions and pollen release processes. We further emphasise the importance of source maps and atmospheric regional transport models in further model improvements. By understanding the relevance of environmental variation to pollen seasonality we can make better predictions regarding the consequences of climate change on plant populations.

Respiratory syncytial virus seasonality, transmission zones, and implications for seasonal prevention strategy in China: a systematic analysis

Respiratory syncytial virus (RSV) represents a substantial global health challenge, with a disproportionately high disease burden in low-income and middle-income countries. RSV exhibits seasonality in most areas globally, and a comprehensive understanding of within-country variations in RSV seasonality could help to define the timing of RSV immunisation programmes. This study focused on China, and aimed to describe the geographical distribution of RSV seasonality, identify distinct RSV transmission zones, and evaluate the potential suitability of a seasonal RSV prevention strategy. We did a systematic analysis of RSV seasonality in China, with use of data on RSV activity extracted from a systematic review of studies published on Embase, MEDLINE, Web of Science, China National Knowledge Infrastructure, Wanfang Data, Chongqing VIP Information, and SinoMed, from database inception until May 5, 2023. We included studies of any design in China reporting at least 25 RSV cases, which aggregated RSV case number by calendar month or week at the province level, and with data covering at least 12 consecutive months before the year 2020 (prior to the COVID-19 pandemic). Studies that used only serology for RSV testing were excluded. We also included weekly data on RSV activity from open-access online databases of the Taiwan National Infection Disease Statistics System and Hong Kong Centre for Health Protection, applying the same eligiblity requirements. Across all datasets, we excluded data on RSV activity from Jan 1, 2020, onwards. We estimated RSV seasonal epidemic onset and duration using the annual average percentage (AAP) approach, and summarised seasonality at the provincial level. We used Pearson's partial correlation analysis to assess the correlation between RSV season duration and the latitude and longitude of the individual provinces. To define transmission zones, we used two independent approaches, an infant-passive-immunisation-driven approach (the moving interval approach, 6-month interval) and a data-driven approach (k-means), to identify groups of provinces with similar RSV seasonality. The systematic review was registered on PROSPERO, CRD42022376993. A total of 157 studies were included along with the two online datasets, reporting data on 194 596 RSV cases over 442 study-years (covering the period from Jan 1, 1993 to Dec 31, 2019), from 52 sites in 23 provinces. Among 21 provinces with sufficient data (≥100 reported cases), the median duration of RSV seasonal epidemics was 4·6 months (IQR 4·1-5·4), with a significant latitudinal gradient (r=-0·69, p<0·0007), in that provinces on or near the Tropic of Cancer had the longest epidemic duration. We found no correlation between longitude and epidemic duration (r=-0·15, p=0·53). 15 (71%) of 21 provinces had RSV epidemics from November to March. 13 (62%) of 21 provinces had clear RSV seasonality (epidemic duration ≤5 months). The moving interval approach categorised the 21 provinces into four RSV transmission zones. The first zone, consisting of five provinces (Fujian, Guangdong, Hong Kong, Taiwan, and Yunnan), was assessed as unsuitable for seasonal RSV immunisation strategies; the other three zones were considered suitable for seasonal RSV immunisation strategies with the optimal start month varying between September (Hebei), October (Anhui, Chongqing, Henan, Hubei, Jiangsu, Shaanxi, Shandong, Shanghai, Sichuan, and Xinjiang), and November (Beijing, Gansu, Guizhou, Hunan, and Zhejiang). The k-means approach identified two RSV transmission zones, primarily differentiated by whether the province was on or near the Tropic of Cancer (Fujian, Guangdong, Hong Kong, Taiwan, Yunan, and Hunan) or not (the remaining 15 provinces). Although substantial variations in RSV seasonality were observed across provinces of China, our study identified distinct transmission zones with shared RSV circulating patterns. These findings could have important implications for decision making on RSV passive immunisation strategy. Furthermore, the methodological framework in this study for defining RSV seasons and identifying RSV transmission zones is potentially applicable to other countries or regions. Nanjing Medical University. For the Chinese translation of the abstract see Supplementary Materials section.

Efficient and flexible thermal-integrated pumped thermal energy storage through composition adjustment

Thermal-integrated pumped thermal electricity storage (TI-PTES) could realize efficient energy storage for fluctuating and intermittent renewable energy. However, the boundary conditions of TI-PTES may frequently change with the variation of times and seasons, which causes a tremendous deterioration to the operating performance. To realize efficient and flexible energy storage in operating conditions, a novel composition-adjustable TI-PTES is proposed, and the operating performance is investigated and compared with composition-fixed TI-PTES. Simulation results show that, compared to composition-fixed TI-PTES, the energy storage efficiency of TI-PTES could be enhanced by the absolute value of 4.4–18.3% by introducing composition adjustment method under various boundary conditions. Besides, tuning sub-system composition could simultaneously adjust the capacities of power input, heat storage and power output, realizing a more flexible operating range for TI-PTES. A case study for an isolated energy community shows that composition-adjustable TI-PTES could realize 100% conversion of off-peak electric energy and reduce daily investment by 35.6% compared with composition-fixed TI-PTES.

Seasonal Changes of Surface-Active Beach Invertebrate Assemblages in Southern Central Victoria, Australia

Invertebrates play a critical role in beach ecosystems, and seasonal variation in their occurrence and abundance likely influences food webs. We examine and characterise seasonal patterns in invertebrate activity on a temperate, southern sandy dune and beach ecosystem at Venus Bay, Victoria, Australia. We index invertebrate abundance, diversity and assemblage composition at fixed-site pitfall traps which were deployed in four transects from the lower dunes to the beach. Seasonal differences occurred in assemblage composition (foredunes only), richness and abundance. Insects dominated assemblages in summer, spring and autumn; crustaceans dominated winter assemblages. Morphospecies richness was lowest in winter (139% higher in summer and 169% higher in autumn). Our results contrast with other studies from temperate beaches in that (1) richness was higher on beaches compared to in foredunes across all seasons and (2) abundance differed significantly such that winter abundance was higher than for all other seasons. Possible explanations include the exposed nature of the study foredunes, marine ecological subsides in the form of beach wrack in winter and/or between-site variations in such factors. Further studies would usefully examine between-beach variation in seasonality in invertebrate activity in foredunes and dunes.