Seasonal variation in non-volatile flavor substances of fresh tea leaves (Camellia sinensis) by integrated lipidomics and metabolomics using UHPLC-Q-Exactive mass spectrometry.

Harvest season exerts great influence on tea quality. Herein, the variations in non-volatile flavor substances in spring and summer fresh tea leaves of four varieties were comprehensively investigated by integrating UHPLC-Q-Exactive based lipidomics and metabolomics. A total of 327 lipids and 99 metabolites were detected, among which, 221 and 58 molecules were significantly differential. The molecular species of phospholipids, glycolipids and acylglycerolipids showed most prominent and structure-dependent seasonal changes, relating to polar head, unsaturation and total acyl length. Particularly, spring tea contained higher amount in aroma precursors of highly unsaturated glycolipids and phosphatidic acids. The contents of umami-enhancing amino acids and phenolic acids, e.g., theanine, theogallin and gallotannins, were increased in spring. Besides, catechins, theaflavins, theasinensins and flavone/flavonol glycosides showed diverse changes. These phytochemical differences covered key aroma precursors, tastants and colorants, and may confer superior flavor of black tea processed using spring leaves, which was verified by sensory evaluation.

Insights into the seasonal characteristics of single particle aerosols in Chengdu based on SPAMS.

To investigate the seasonal characteristics in air pollution in Chengdu, a single particle aerosol mass spectrometry was used to continuously observe atmospheric fine particulate matter during one-month periods in summer and winter, respectively. The results showed that, apart from O3, the concentrations of other pollutants (CO, NO2, SO2, PM2.5 and PM10) were significantly higher in winter than in summer. All single particle aerosols were divided into seven categories: biomass burning (BB), coal combustion (CC), Dust, vehicle emission (VE), K mixed with nitrate (K-NO3), K mixed with sulfate and nitrate (K-SN), and K mixed with sulfate (K-SO4) particles. The highest contributions in both seasons were VE particles (24%). The higher contributions of K-SO4 (16%) and K-NO3 (10%) particles occurred in summer and winter, respectively, as a result of their different formation mechanisms. S-containing (K-SO4 and K-SN), VE, and BB particles caused the evolution of pollution in both seasons, and they can be considered as targets for future pollution reduction. The mixing of primary sources particles (VE, Dust, CC, and BB) with secondary components was stronger in winter than in summer. In summer, as pollution worsens, the mixing of primary sources particles with 62 [NO3]- weakened, but the mixing with 97 [HSO4]- increased. However, in winter, the mixing state of particles did not exhibit an obvious evolution rules. The potential source areas in summer were mainly distributed in the southern region of Sichuan, while in winter, besides the southern region, the contribution of the western region cannot be ignored.

Seasonal influenza vaccination: A global review of national policies in 194 WHO member states in 2022.

INTRODUCTION: Seasonal influenza vaccination prevents severe influenza disease and death. The World Health Organization (WHO) encourages all countries to consider annual seasonal influenza vaccination for health workers, people with chronic conditions, older adults, pregnant women and other high-risk populations as relevant for their national context. This paper provides a global update on the status of countries' influenza vaccination policies and programmes as of December 2022. METHODS: We analysed the WHO-UNICEF (United Nations Children's Fund) Joint Reporting Form on Immunization's influenza vaccine-related data. We used STATA 17 to conduct descriptive analyses of reported seasonal influenza vaccine availability and seasonal influenza vaccination policies globally. RESULTS: Seasonal influenza vaccine doses were available in 74 % of WHO Member States (143/194) in 2022. Fewer countries, 66 % of WHO Member States (128/194), had a seasonal influenza vaccination policy, of which 68 countries reported having a policy for the public sector, 53 for the public and private sectors, two for the private sector only, and five did not report the sector. More than half of WHO Member States (100 countries) recommend annual seasonal influenza vaccination for all four of the WHO recommended priority groups. Influenza vaccination coverage data were reported by 64 countries; globally the median coverage rates varied by group: 37 % for pregnant women, 55 % for older adults and 62 % for health workers. DISCUSSION: The number of countries using seasonal influenza vaccines has grown over time, but there is still opportunity for continued development and strengthening of national programmes, particularly in low- and middle-income countries (LMICs). To support countries, WHO is providing technical guidance and resources to enable better reporting of influenza vaccination data. More complete and higher quality data will help countries and global health stakeholders to support national decision-making and programme strengthening. Where available, WHO encourages countries to co-administer influenza and COVID-19 vaccination to increase programmatic efficiency and coverage of both vaccines among recommended groups.

Tanycytes from a bird's eye view: gene expression profiling of the tanycytic region under different seasonal states in the Svalbard ptarmigan.

In mammals and birds, tanycytes are known to regulate thyroid hormone conversion, and this process is central to the control of seasonal reproduction. In mammals, this cell type is also implicated in retinoic acid signalling, neurogenesis, and nutritional gatekeeping, all of which have been linked to hypothalamic regulation of energy metabolism. Less is known about these potential wider roles of tanycytes in birds. To address this gap, we combined LASER capture microdissection and transcriptomics to profile the tanycytic region in male Svalbard ptarmigan, a High Arctic species with photoperiod-dependent seasonal rhythms in reproductive activation and body mass. Short photoperiod (SP) adapted birds were transferred to constant light (LL) to trigger breeding and body mass loss. After five months under LL, the development of photorefractoriness led to spontaneous re-emergence of the winter phenotype, marked by the termination of breeding and gain in body mass. The transfer from SP to LL initiated gene expression changes in both thyroid hormone and retinoic acid pathways, as described in seasonal mammals. Furthermore, transcriptomic signatures of cell differentiation and migration were observed. Comparison to data from Siberian hamsters demonstrated that a photoperiod-dependent re-organisation of the hypothalamic tanycytic region is likely a conserved feature. Conversely, the spontaneous development of photorefractoriness showed a surprisingly small number of genes that reverted in expression level, despite reversal of the reproductive and metabolic phenotype. Our data suggest general conservation of tanycyte biology between photoperiodic birds and mammals and raise questions about the mechanistic origins of the photorefractory state.

Comparison of flea diversity in the burrows of Richardson's ground squirrels (Urocitellus richardsonii) in urban and rural sites in central Saskatchewan, Canada.

Spatial and temporal differences in the relative abundance of arthropod vectors are important factors that influence the risk of disease for mammalian hosts. Seasonal changes in the diversity and abundance of fleas (Siphonaptera) in Richardson's ground squirrel (Urocitellus richardsonii) burrows were studied at two sites in central Saskatchewan. A total of 225 fleas (151 at an urban site and 74 at a rural site) were collected. Flea prevalence differed among seasons at the urban site but not at the rural site. Of the nine flea species detected (eight at the urban site and six at the rural site), Oropsylla rupestris, O. bruneri, O. labis, O. tuberculata, and Aetheca wagneri are vectors of Yersinia pestis, the causative agent of plague. The presence and abundance of some fleas differed between sites and seasons. Neopsylla inopina and O. rupestris were the most abundant species at the urban site during the spring and summer, respectively, while O. bruneri was the most abundant species at the rural site. Our findings may have implications for the management of the black-tailed prairie dogs (Cynomys ludovicianus) in southwestern Saskatchewan because they coexist with U. richardsonii, are hosts for Oropsylla, and are at great risk of plague exposure/infection.

Seasonal Study Chemical Profiles and Bioactivities of Hedychium coronarium J. Koenig Essential Oils: Nematicidal, Insecticidal, Phytotoxic, Antifungal Potentials, and Molecular Docking Insights.

Hedychium coronarium plant has attracted considerable attention from researchers due to its diverse phytochemical composition and potential therapeutic applications. The objective of this study was to evaluate the phytochemical profile and biological attributes of H. coronarium essential oils collected during different seasons in the Kumaun region of Uttarakhand. The essential oils were extracted from the rhizomes using hydrodistillation with a Clevenger-type apparatus yielding between 0.07% to 0.38% (w/w). The major compounds identified by GC-MS analysis exhibited seasonal variations and included 1,8-cineole (26.6-38.5%), coronarin E (11.9-18.8%), α-pinene (5.00-14.9%), α-terpineol (4.2-9.3%), (E)-ß-caryophyllene (1.2-9.7%), and linalool (0.4-2.9%). To illustrate the variations in oil composition, visualization techniques such as heat map and PCA were employed. The essential oils demonstrated potential biological activity in all tests conducted. The molecular modeling study indicated that the potential mechanism may be associated with acetylcholinesterase. Consequently, this study contributes to the development of novel natural pesticides.

Deep insights into the assembly mechanisms, co-occurrence patterns, and functional roles of microbial community in wastewater treatment plants.

The understanding of activated sludge microbial status and roles is imperative for improving and enhancing the performance of wastewater treatment plants (WWTPs). In this study, we conducted a deep analysis of activated sludge microbial communities across five compartments (inflow, effluent, and aerobic, anoxic, anaerobic tanks) over temporal scales, employing high-throughput sequencing of 16S rRNA amplicons and metagenome data. Clearly discernible seasonal patterns, exhibiting cyclic variations, were observed in microbial diversity, assembly, co-occurrence network, and metabolic functions. Notably, summer samples exhibited higher α-diversity and were distinctly separated from winter samples. Our analysis revealed that microbial community assembly is influenced by both stochastic processes (66%) and deterministic processes (34%), with winter samples demonstrating more random assembly compared to summer. Co-occurrence patterns were predominantly mutualistic, with over 96% positive correlations, and summer networks were more organized than those in winter. These variations were significantly correlated with temperature, total phosphorus and sludge volume index. However, no significant differences were found among microbial community across five compartments in terms of ß diversity. A core community of keystone taxa was identified, playing key roles in eight nitrogen and eleven phosphorus cycling pathways. Understanding the assembly mechanisms, co-occurrence patterns, and functional roles of microbial communities is essential for the design and optimization of biotechnological treatment processes in WWTPs.

Relationship between sun exposure and seasonal affective disorder symptoms in rural older people with different personalities: a cross-sectional study.

OBJECTIVES: Evidence suggests that environmental support, personality traits, and psychological factors can influence seasonal changes in human mood and behavior, particularly in rural middle-aged women and older people. This study aimed to quantify the associations between personality traits, seasonal affective disorder symptoms, and sun exposure in rural older people. METHODS: This study is a cross-sectional analytical study, the participants were 300 rural older persons from 12 natural villages and 5 geriatric service centers in 4 different cities in Jiangxi Province, China. The Eysenck Personality Questionnaire (EPQ), the Personal Inventory of Depression and Seasonal Affective Disorder (PIDS-SA-SimpChi), and the Sunlight Exposure Scale were used to conduct follow-up interviews throughout the year. Spatial analysis was performed using ArcGIS and Geodetic Probes. The data were analyzed using SPSS 21 and Amos 23.0 mediated models. RESULTS: Rural older people with low sun exposure exhibited higher personality trait scores (p < 0.001). Personality traits were directly associated with seasonal affective disorder symptoms(p < 0.01); Sun exposure mediated this effect in rural older people (p < 0.05). CONCLUSION: High-scoring personalities are more typical of rural older people with low sun exposure, and there is a greater risk of emotional and behavioral instability. Latitudinal differences are not a determinant of SAD. Increased sun exposure is associated with symptom relief. The promotion of light therapy devices in rural areas with low sunlight is warranted.

Seasonal Comparison of Pre-Adolescent Soccer Players' Physical Performance Using an Objective Physical Test Battery.

BACKGROUND/OBJECTIVE: Soccer is a multifactorial sport, requiring physical, psychological, technical, and tactical skills to succeed. Monitoring and comparing physical characteristics over time is essential to assess players' development, customize training, and prevent injury. The use of wearable sensors is essential to provide accurate and objective physical data. METHODS: In this longitudinal study, 128 male adolescent soccer players (from Under 12 to Under 19) were evaluated at two time points (pre- and post-season). Participants completed the Euleria Lab test battery, including stability, countermovement and consecutive jumps, agility, and quick feet tests. A single Inertial Measurement Unit sensor provided quantitative data on fifteen performance metrics. Percentage changes were compared to the Smallest Worthwhile Changes to assess significant changes over time. RESULTS: The results showed significant improvements in most variables, including a 19.7% increase in quick feet, 10.9% in stability, and 9.6% in countermovement jumps. In principal component analysis, we identified four principal components-strength-power, balance, speed-agility, and stiffness-that explained over 80% of the variance. CONCLUSIONS: These findings align with previous studies assessing seasonal changes in adolescent soccer players, showing that the proposed test battery seems to be adequate to highlight physical performance changes and provide coaches with meaningful data to customize training and reduce injury rates.

Assessment of pesticide residues: a comprehensive analysis of seasonal trends and health implications.

This study assessed the presence of eight pesticide residues in the Indus River, Mianwali, Pakistan, focusing on three sampling sites (S1, S2, and S3) in water, sediment, and the fish species Cyprinus carpio during both dry and wet seasons. Analysis was conducted using gas chromatography with an electron capture detector. Results indicated elevated pesticide concentrations in both seasons, with levels of 0.84 and 0.62 µg/L in water, 12.47 and 9.21 µg/g/dw in sediment, and 17.33 and 12.17 µg/g/ww in fish, with higher concentrations observed during the dry season. Cypermethrin and carbofuran were the primary pesticides detected in water, while endosulfan and cypermethrin were dominant in sediment and fish tissue, often exceeding standard safety thresholds. Principal Component Analysis (PCA) and cluster analysis revealed stronger correlations between sediment and fish muscle, with varying associations among pesticides across seasons. The Hazard Index (HI) surpassed 1 in both seasons, signaling potential health risks to humans. These findings underscore the substantial risk agricultural pesticides pose to the aquatic ecosystem and food chain, highlighting the urgent need for sustainable agricultural practices and stricter regulations to minimize pesticide use and encourage eco-friendly pest management strategies.

Dynamics of phytoplankton assemblages determined by the HPLC-PIGMENTUM approach and the related environmental variables in the northern Chinese sea.

During the spring and summer of 2021, two investigations were conducted in the northern Chinese sea by using the high-performance liquid chromatography with the pigment-based chemotaxonomic tool PIGMENTUM. Results showed that the average chlorophyll a (Chl a) concentration during spring was significantly higher (p < 0.01) than that during summer. 19'-hexanoyloxyfucoxanthin-containing algae, alloxanthin-containing algae (ACA), and fucoxanthin-containing algae (FCA) were the main pigment groups in spring, whereas zeaxanthin-containing algae (ZCA) and peridinin-containing algae (PeCA) were dominated in summer. Five ecological provinces were divided, and the phytoplankton biomass (Chl a) in Province V was the lowest. Redundancy analysis showed that ACA, FCA, and PeCA were positively correlated with nutrients; in comparison, ZCA preferred high salinity. The PIGMENTUM estimates were significantly positively correlated (p < 0.01) with CHEMTAX for all phytoplankton assemblages. Nevertheless, the coefficients of determination and slope by regression analysis between two methods showed large differences for several phytoplankton groups.

Sources of PM2.5 exposure misclassification in three Finnish register-based study populations and the impact on attenuation of health effect estimates.

Air pollution is a leading environmental health risk factor. The risk estimates, primarily based on air pollution epidemiology, are sensitive to exposure misclassification, which can result in underestimation. To address some of these challenges, our aim is to investigate how the length of the period over which the exposure is averaged, trends in long-term PM2.5 concentrations, and the seasonal variability are associated with each other. Furthermore, we assess the impact of residential relocation on exposure levels and quantify random exposure misclassification due to modelling and its impact on the attenuation of effects with respect to averaging time. We used nested air quality modelling across Finland, gridded population, and address histories from three study populations: the MATEX pregnancy and preschool children cohorts, as well as the FINPARK study's individuals diagnosed with Parkinson's disease and their controls, to estimate PM2.5 exposures. The prediction error was estimated by comparing modelled concentrations to observations and by using previous estimates for random monitoring instrument error. Due to the decreasing trend in PM2.5 concentrations, exposure levels rose progressively with longer averaging times, increasing by up to 28 % over a 16-year period. The shorter the exposure period, the more pronounced the seasonal effects: pregnant mothers' trimester-specific exposures were 13-22 % higher for trimesters ending in spring and 10-16 % lower for those ending in autumn compared to the average for the entire pregnancy. Residential relocation had a relatively minor impact on the exposure levels of the preschool children and adult FINPARK study population, but this effect was possibly partly masked by the decreasing trend. The results indicated that using predicted concentrations led to random exposure misclassification and potentially attenuated health effects. This effect became more notable when increasing the length of the exposure period from 3 months to 5 years, doubling the underestimation ratio from 1.5 to 3.1.

Intracellular metabolomic profiling of Picochlorum sp. under diurnal conditions mimicking outdoor light, temperature, and seasonal variations.

INTRODUCTION: This study focuses on metabolic profiling of a robust marine green algal strain Picochlorum sp. MCC39 that exhibits resilient growth under diverse outdoor open pond conditions. Given its potential for producing high-value chemicals through metabolic engineering, understanding its metabolic dynamics is crucial for pathway modification. OBJECTIVES: This study primarily aimed to investigate the metabolic response of Picochlorum sp. to environmental changes. Unlike heterotrophs, algae are subject to diurnal light and temperature, which affect their growth rates and metabolism. Using an environmental photobioreactor (ePBR), we explored how the algal strain adapts to fluctuations in light intensities and temperature within a simulated pond environment. METHODS: We performed a reverse phase ion pairing-LC/MS-MS based metabolome profiling of the MCC39 strain cultivated in simulated pond conditions in ePBR. The experimental setup included diurnal and bi-seasonal variations in light intensities and temperature. RESULTS: The metabolome profile revealed significant differences in 85 metabolites, including amino acids, carboxylic acids, sugar phosphates, purines, pyrimidines, and dipeptides, which exhibited up to 25-fold change in relative concentration with diurnal variations. Seasonal variations also influenced the production of storage molecules, revealing a discernible pattern. The accumulation pattern of metabolites involved in cellular wall formation and energy generation indicated a well-coordinated initiation of photosynthesis and the Calvin cycle with the onset of light. CONCLUSION: The results contribute to a deeper understanding of the adaptability and metabolic response of Picochlorum sp., laying the groundwork for future advancements in algal strain modification.

Influenza vaccine effectiveness in immunocompromised patients with cancer: A Danish nationwide register-based cohort study.

BACKGROUND: Influenza vaccination is free of charge for Danish citizens with acquired immunodeficiency but recommendations do not specifically target patients with cancer. This study investigated whether influenza vaccination reduces the main outcome of overall mortality and the secondary outcomes of influenza requiring treatment, pneumonia, myocardial infarction, stroke, heart failure, and venous thromboembolism in patients with cancer. METHODS: This was a register-based nationwide cohort study. Adjusted hazard ratios (aHRs) and 95% confidence intervals (95% CIs) for overall mortality and secondary outcomes were estimated using Cox proportional hazards models. Analyses were conducted separately for four subgroups: patients aged <65 years with solid tumors, patients aged ≥65 years with solid tumors, patients aged <65 years with hematological cancer, and patients aged ≥65 years with hematological cancer. RESULTS: A total of 53,249 adult patients with solid tumors who received chemotherapy and 22,182 adult patients with hematological cancer were followed for up to five influenza seasons in the study period of 2007-2018. In the main analysis covering December-March, influenza vaccination was associated with reduced overall mortality in all four subgroups. The reduction was most pronounced in patients with hematological cancer aged <65 years (aHR, 0.66; 95% CI, 0.51-0.87) and smallest in patients with solid tumors aged <65 years (aHR, 0.91; 95% CI, 0.84-0.99). In sensitivity analyses covering January-March, the aHR was 0.87 (95% CI, 0.65-1.16) in patients with hematological cancer aged <65 years and 1.01 (95% CI, 0.92-1.10) in patients with solid tumors aged <65 years. Results for the secondary outcomes were inconclusive. CONCLUSIONS: The results of this study cannot reject that influenza vaccination reduces overall mortality in immunocompromised patients with cancer. The results must be interpreted with caution because of potential unmeasured confounding, which can result in the overestimation of influenza vaccine effectiveness.

Clinical and Molecular Analysis of Longitudinal Rhinitis Phenotypes in an Urban Birth Cohort.

BACKGROUND: Chronic rhinitis symptoms cause significant health burden among children and can have a heterogeneous presentation. Defining phenotypes of childhood chronic rhinitis and associated pathobiology may lead to prevention or improved treatments. OBJECTIVES: To identify longitudinal patterns of rhinitis symptoms in childhood and determine their associations with early life risk factors, allergic comorbidities, and nasal epithelial cell gene expression. METHODS: Chronic rhinitis symptoms were evaluated from ages 1 through 11 years in 485 urban children at high risk for allergic disease in the Urban Environment and Childhood Asthma (URECA) birth cohort. We identified longitudinal rhinitis phenotypes and their relationships to early life exposures, atopic comorbidities, and patterns of nasal epithelial gene expression at age 11 years. RESULTS: Chronic rhinitis symptoms started early in many children and were a risk factor for developing aeroallergen sensitization. We identified four longitudinal rhinitis phenotypes: low/minimal disease, persistent, persistent decreasing, and late increasing. Persistent rhinitis was most closely linked to allergic sensitization and asthma. Risk factors for persistent rhinitis included frequent colds (p<0.001), antibiotic use (p<0.001), and reduced exposure to common indoor aeroallergens (p=0.003). Compared to low/minimal disease, rhinitis phenotypes were associated with increased expression of canonical Type 2 genes and decreased expression of immune response genes. CONCLUSIONS: In urban children, rhinitis symptoms often precede aeroallergen sensitization. Rhinitis phenotypes based on symptoms had distinct risk factors and nasal transcriptome. These results suggest that focusing on early life risk factors and distinct immune mechanisms may be a target to preventing chronic rhinitis in childhood.

Migratory herbivorous waterfowl track multiple resource waves during spring migration.

East Asian herbivorous waterfowl intensively use farmland in spring, next to their natural habitat. Accordingly, they might have expanded their migration strategy from merely tracking the green wave of newly emerging vegetation to also incorporating the availability of post-harvest agricultural seeds (here dubbed the seed wave). However, if and how waterfowl use multiple food resources to time their seasonal migration is still unknown. We test this migration strategy using 167 spring migration tracks of five East Asian herbivorous waterfowl species and mixed-effect resource selection function models. We found that all study species arrived at their core stopover sites in the Northeast China Plain after agricultural seeds became available, extended their stay after spring vegetation emerged and arrived at their breeding sites around the emergence of vegetation. At the core stopover sites, all study species used snowmelt as a cue to track seed availability, although smaller-bodied species tended to arrive later. At the breeding sites, swans tracked the onset of vegetation emergence and geese tracked the mid- or end phases of snowmelt. Our findings suggest that waterfowl track multiple resource waves to fine-tune their migration, highlighting new opportunities for conservation.

The effect of seasonal heat acclimatization on cool-seeking behaviour during passive heat stress in young adults.

Seasonal heat acclimatization is known to enhance autonomic thermoeffector responses, whereas the behavioural response following seasonal heat acclimatization remains unknown. We investigated whether seasonal heat acclimatization would alter autonomic and behavioural thermoregulatory responses. Sixteen healthy participants (eight males and eight females) underwent two trials involving 50 min of lower-leg passive heating (lower-leg submersion in 42°C water) with (Fan trial) and without (No fan trial) the voluntary use of a fan in a moderate thermal environment (27°C, 50% relative humidity) across winter and summer months. In Fan trials, participants were allowed to use a fan to maintain thermal comfort, but this was not allowed in the No fan trials. Cool-seeking behaviour was initiated at a lower change in rectal temperature [mean (SD): 0.21 (0.18)°C vs. 0.11 (0.13)°C, P = 0.0327] and change in mean skin temperature [2.34 (0.56)°C vs. 1.81 (0.32)°C, P < 0.0001], and cooling time was longer [16.46 (5.62) vs. 20.40 (4.87) min, P = 0.0224] in summer compared with winter. However, thermal perception was not modified by season during lower-leg passive heating (all P > 0.0864). Furthermore, rectal temperature was higher in summer (P = 0.0433), whereas mean body temperature and skin temperature were not different (all P > 0.0631) between the two seasons in Fan trials. In conclusion, seasonal heat acclimatization enhanced the cool-seeking behaviour from winter to summer.

Atmospheric Mercury Concentrations and Isotopic Compositions Impacted by Typical Anthropogenic Mercury Emissions Sources.

Coal-fired power plants (CFPPs) and cement plants (CPs) are important anthropogenic mercury (Hg) emission sources. Mercury speciation profiles in flue gas are different among these sources, leading to significant variations in local atmospheric Hg deposition. To quantify the impacts of Hg emissions from CFPPs and CPs on local-scale atmospheric Hg deposition, this study determined concentrations and isotopes of ambient gaseous elemental mercury (GEM), particulate-bound mercury (PBM), and precipitation total Hg (THg) at multiple locations with different distances away from a CFPP and a CP. Higher concentrations of GEM and precipitation THg in the CFPP area in summer were caused by higher Hg emission from the CFPP, resulting from higher electricity demand. Higher concentrations of GEM, PBM, and precipitation THg in the CP area in winter compared to those in summer were related to the higher output of cement. Atmospheric Hg concentration peaked near the CFPP and CP and decreased with distance from the plants. Elevated GEM concentration in the CFPP area was due to flue gas Hg0 emissions, and high PBM and precipitation Hg concentrations in the CP area were attributed to divalent Hg emissions. It was estimated that Hg emissions from the CFPP contributed 58.3 ± 20.9 and 52.3 ± 25.9% to local GEM and PBM, respectively, and those from the CP contributed 47.0 ± 16.7 and 60.0 ± 25.9% to local GEM and PBM, respectively. This study demonstrates that speciated Hg from anthropogenic emissions posed distinct impacts on the local atmospheric Hg cycle, indicating that Hg speciation profiles from these sources should be considered for evaluating the effectiveness of emission reduction policies. This study also highlights the Hg isotope as a useful tool for monitoring environmental Hg emissions.

Influenza virus shedding and symptoms: Dynamics and implications from a multiseason household transmission study.

Isolation of symptomatic infectious persons can reduce influenza transmission. However, virus shedding that occurs without symptoms will be unaffected by such measures. Identifying effective isolation strategies for influenza requires understanding the interplay between individual virus shedding and symptom presentation. From 2017 to 2020, we conducted a case-ascertained household transmission study using influenza real-time RT-qPCR testing of nasal swabs and daily symptom diary reporting for up to 7 days after enrolment (≤14 days after index onset). We assumed real-time RT-qPCR cycle threshold (Ct) values were indicators of quantitative virus shedding and used symptom diaries to create a score that tracked influenza-like illness (ILI) symptoms (fever, cough, or sore throat). We fit phenomenological nonlinear mixed-effects models stratified by age and vaccination status and estimated two quantities influencing isolation effectiveness: shedding before symptom onset and shedding that might occur once isolation ends. We considered different isolation end points (including 24 h after fever resolution or 5 days after symptom onset) and assumptions about the infectiousness of Ct shedding trajectories. Of the 116 household contacts with ≥2 positive tests for longitudinal analyses, 105 (91%) experienced ≥1 ILI symptom. On average, children <5 years experienced greater peak shedding, longer durations of shedding, and elevated ILI symptom scores compared with other age groups. Most individuals (63/105) shed <10% of their total shed virus before symptom onset, and shedding after isolation varied substantially across individuals, isolation end points, and infectiousness assumptions. Our results can inform strategies to reduce transmission from symptomatic individuals infected with influenza.

Dispersal limitation determines the ecological processes that regulate the seasonal assembly of bacterial communities in a subtropical river.

Bacteria play a crucial role in pollutant degradation, biogeochemical cycling, and energy flow within river ecosystems. However, the underlying mechanisms governing bacterial community assembly and their response to environmental factors at seasonal scales in subtropical rivers remain poorly understood. In this study, we conducted 16S rRNA gene amplicon sequencing on water samples from the Liuxi River to investigate the composition, assembly processes, and co-occurrence relationships of bacterial communities during the wet season and dry season. The results demonstrated that seasonal differences in hydrochemistry significantly influenced the composition of bacterial communities. A more heterogeneous community structure and increased alpha diversity were observed during the dry season. Water temperature emerged as the primary driver for seasonal changes in bacterial communities. Dispersal limitation predominantly governed community assembly, however, during the dry season, its contribution increased due to decreased immigration rates. Co-occurrence network analysis reveals that mutualism played a prevailing role in shaping bacterial community structure. Compared to the wet season, the network of bacterial communities exhibited higher modularity, competition, and keystone species during the dry season, resulting in a more stable community structure. Although keystone species displayed distinct seasonal variations, Proteobacteria and Actinobacteria were consistently abundant keystone species maintaining network structure in both seasons. Our findings provide insights into how bacterial communities respond to seasonal environmental changes, uncovering underlying mechanisms governing community assembly in subtropical rivers, which are crucial for the effective management and conservation of riverine ecosystems.