Influence of Season on Biodegradation Rates in Rivers

Biodegradation plays a key role in the fate of chemicals in the environment. The variability of biodegradation in time can cause uncertainty in evaluating the environmental persistence and risk of chemicals. However, the seasonality of biodegradation in rivers has not yet been the subject of environmentally relevant testing and systematic investigation for large numbers of chemicals. In this work, we studied the biodegradation of 96 compounds during four seasons at four locations (up- and downstream of WWTPs located on two Swedish rivers). Significant seasonality (ANOVA, p < 0.05) of the first-order rate constant for primary biodegradation was observed for most compounds. Variations in pH and total bacterial cell count were not the major factors explaining the seasonality of biodegradation. Deviation from the classical Arrhenius-type behavior was observed for most of the studied compounds, which calls into question the application of this relationship to correct biodegradation rate constants for differences in environmental temperature. Similarities in magnitude and seasonality of biodegradation rate constants were observed for some groups of chemicals possessing the same functional groups. Moreover, reduced seasonality of biodegradation was observed downstream of WWTPs, while biodegradation rates of most compounds were not significantly different between up- and downstream.

NORSE seasonality may vary geographically in adults

The mechanisms causing new onset refractory status epilepticus (NORSE) are often unknown. Recently, a seasonal variation with NORSE peaking during the summer was described in a mixed cohort of adults and children why we here studied the seasonal variation in a Danish status epilepticus (SE) cohort. This retrospective cohort study comprised SE patients aged ≥18 diagnosed and treated 2008-2017 at the Odense University Hospital. Clinical characteristics and seasonality of patients fulfilling the diagnostic criteria for NORSE were compared with patients with refractory SE (RSE) due to other reasons and with the seasonal variation of autoantibodies associated with autoimmune encephalitis in the Danish autoimmune encephalitis register. In this cohort, 26 patients met NORSE criteria. As compared to RSE patients not fulfilling NORSE criteria (n = 152), NORSE patients were more likely to have symptoms of systemic inflammation (C-reactive protein concentrations ≥10 mg/L or fever ≥38°C) at admission; nine fulfilled the criteria for febrile infection related epilepsy syndrome (FIRES). In contrast to the even seasonal distribution of patients with RSE not fulfilling the NORSE criteria, admissions due to NORSE peaked during the winter (46.1%, p = 0.04 as compared to non-NORSE RSE); six out of nine FIRES episodes occurred in the winter season. The seasonal variation was not explained by a seasonal variation of the detection rates of autoantibodies associated with autoimmune encephalitis (incl. NMDAR, LGI1, CASPR2, GABAR, GFAP) in a Danish nationwide register (n = 259). In conclusion, we confirm the seasonality of NORSE in a Danish cohort, however, with a peak during winter suggesting a geographical variation not solely explained by autoimmune encephalitis associated with known autoantibodies. PLAIN LANGUAGE SUMMARY: The study investigated the seasonal patterns of new-onset refractory status epilepticus (NORSE), i.e. severe seizures that occur without an obvious cause and require very intensive treatment. In contrast to the previously observed peak frequency in summer, this Danish study found that NORSE cases peak in winter. Furthermore, the seasonal variation in NORSE cases was not found to be associated with autoimmune encephalitis caused by known autoantibodies. Together with the high rate of patients showing symptoms of systemic inflammation compared to other status epilepticus patients, the data suggest a link between misdirected immune system responses and NORSE. The study can therefore help in the further search for the currently unknown causes of NORSE.

Uncoupling of behavioral and metabolic 24-h rhythms in reindeer

Reindeer in the Arctic seasonally suppress daily circadian patterns of behavior present in most animals.1 In humans and mice, even when all daily behavioral and environmental influences are artificially suppressed, robust endogenous rhythms of metabolism governed by the circadian clock persist and are essential to health.2,3 Disrupted rhythms foster metabolic disorders and weight gain.4 To understand circadian metabolic organization in reindeer, we performed behavioral measurements and untargeted metabolomics from blood plasma samples taken from Eurasian tundra reindeer (Rangifer tarandus tarandus) across 24 h at 2-h intervals in four seasons. Our study confirmed the absence of circadian rhythms of behavior under constant darkness in the Arctic winter and constant daylight in the Arctic summer, as reported by others.1 We detected and measured the intensity of 893 metabolic features in all plasma samples using untargeted ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS). A core group of metabolites (66/893 metabolic features) consistently displayed 24-h rhythmicity. Most metabolites displayed a robust 24-h rhythm in winter and spring but were arrhythmic in summer and fall. Half of all measured metabolites displayed ultradian sleep-wake dependence in summer. Irrespective of the arrhythmic behavior, metabolism is rhythmic (24 h) in seasons of low food availability, potentially favoring energy efficiency. In seasons of food abundance, 24-h rhythmicity in metabolism is drastically reduced, again irrespective of behavioral rhythms, potentially fostering weight gain.

Environmental drivers of global variation in home range size of terrestrial and marine mammals

As animal home range size (HRS) provides valuable information for species conservation, it is important to understand the driving factors of HRS variation. It is widely known that differences in species traits (e.g. body mass) are major contributors to variation in mammal HRS. However, most studies examining how environmental variation explains mammal HRS variation have been limited to a few species, or only included a single (mean) HRS estimate for the majority of species, neglecting intraspecific HRS variation. Additionally, most studies examining environmental drivers of HRS variation included only terrestrial species, neglecting marine species. Using a novel dataset of 2800 HRS estimates from 586 terrestrial and 27 marine mammal species, we quantified the relationships between HRS and environmental variables, accounting for species traits. Our results indicate that terrestrial mammal HRS was on average 5.3 times larger in areas with low human disturbance (human footprint index [HFI] = 0), compared to areas with maximum human disturbance (HFI = 50). Similarly, HRS was on average 5.4 times larger in areas with low annual mean productivity (NDVI = 0), compared to areas with high productivity (NDVI = 1). In addition, HRS increased by a factor of 1.9 on average from low to high seasonality in productivity (standard deviation (SD) of monthly NDVI from 0 to 0.36). Of these environmental variables, human disturbance and annual mean productivity explained a larger proportion of HRS variance than seasonality in productivity. Marine mammal HRS decreased, on average, by a factor of 3.7 per 10°C decline in annual mean sea surface temperature (SST), and increased by a factor of 1.5 per 1°C increase in SST seasonality (SD of monthly values). Annual mean SST explained more variance in HRS than SST seasonality. Due to the small sample size, caution should be taken when interpreting the marine mammal results. Our results indicate that environmental variation is relevant for HRS and that future environmental changes might alter the HRS of individuals, with potential consequences for ecosystem functioning and the effectiveness of conservation actions.

Dissociating Mechanisms That Underlie Seasonal and Developmental Programs for the Neuroendocrine Control of Physiology in Birds

Long-term programmed rheostatic changes in physiology are essential for animal fitness. Hypothalamic nuclei and the pituitary gland govern key developmental and seasonal transitions in reproduction. The aim of this study was to identify the molecular substrates that are common and unique to developmental and seasonal timing. Adult and juvenile quail were collected from reproductively mature and immature states, and key molecular targets were examined in the mediobasal hypothalamus (MBH) and pituitary gland. qRT-PCR assays established deiodinase type 2 (DIO2) and type 3 (DIO3) expression in adults changed with photoperiod manipulations. However, DIO2 and DIO3 remain constitutively expressed in juveniles. Pituitary gland transcriptome analyses established that 340 transcripts were differentially expressed across seasonal photoperiod programs and 1,189 transcripts displayed age-dependent variation in expression. Prolactin (PRL) and follicle-stimulating hormone subunit beta (FSHβ) are molecular markers of seasonal programs and are significantly upregulated in long photoperiod conditions. Growth hormone expression was significantly upregulated in juvenile quail, regardless of photoperiodic condition. These findings indicate that a level of cell autonomy in the pituitary gland governs seasonal and developmental programs in physiology. Overall, this paper yields novel insights into the molecular mechanisms that govern developmental programs and adult brain plasticity.

Spatiotemporal variability in population demography and morphology of the habitat-forming macroalga Saccorhiza polyschides in the Western English Channel

BACKGROUND AND AIMS

Large brown macroalgae serve as foundation organisms along temperate and polar coastlines, providing a range of ecosystem services. Saccorhiza polyschides is a warm-temperate kelp-like species found in the northeast Atlantic, which is suggested to have proliferated in recent decades across the southern UK, possibly in response to increasing temperatures, physical disturbance and reduced competition. However, little is known about S. polyschides with regard to ecological functioning and population dynamics across its geographical range. Here we examined the population demography of S. polyschides populations in southwest UK, located within the species' range centre, to address a regional knowledge gap and to provide a baseline against which to detect future changes.

METHODS

Intertidal surveys were conducted during spring low tides at three sites along a gradient of wave exposure in Plymouth Sound (Western English Channel) over a period of 15 months. Density, cover, age, biomass and morphology of S. polyschides were quantified. Additionally, less frequent sampling of shallow subtidal reefs was conducted to compare intertidal and subtidal populations.

KEY RESULTS

We recorded pronounced seasonality, with fairly consistent demographic patterns across sites and depths. By late summer, S. polyschides was a dominant habitat-former on both intertidal and subtidal reefs, with maximum standing stock exceeding 13 000 g wet weight m-2.

CONCLUSIONS

Saccorhiza polyschides is a conspicuous and abundant member of rocky reef assemblages in the region, providing complex and abundant biogenic habitat for associated organisms and high rates of primary productivity. However, its short-lived pseudo-annual life strategy is in stark contrast to dominant long-lived perennial laminarian kelps. As such, any replacement or reconfiguration of habitat-forming macroalgae due to ocean warming will probably have implications for local biodiversity and community composition. More broadly, our study demonstrates the importance of high-resolution cross-habitat surveys to generate robust baselines of kelp population demography, against which the ecological impacts of climate change and other stressors can be reliably detected.

Factors to take into account when interpreting 25-hydroxy-vitamin D serum levels

BACKGROUND

Assessing vitamin D status, typically evaluated using serum or plasma 25-hydroxy vitamin D [25(OH)D] concentration, is complex because of various influencing factors.

METHODS

Seasonality significantly affects intra-individual variability in 25(OH)D levels. This variation can be addressed by employing cosinor functions that are tailored to the geographical location of the patient to correct for seasonal effects. In addition to seasonality, genetic factors, such as DBP polymorphism and body composition, particularly adiposity, play crucial roles. Dialysis patients with DBP 2-2 phenotype exhibit higher vitamin D requirements. Genotyping/phenotyping of DBP allows for better tailored vitamin D supplementation. The lipid-soluble nature of vitamin D also interacts with plasma components such as serum triglycerides, which can influence vitamin D measurements. Adiposity, which is negatively correlated with vitamin D concentration, necessitates body mass-based mathematical adjustments for accurate vitamin D assessment in subjects with extreme BMI values.

CONCLUSIONS

Accordingly, vitamin D replacement therapy must be personalized, taking into account factors such as body size and seasonal variations, to effectively reach the target serum 25(OH)D concentrations.

Linear enamel hypoplasia in Homo naledi reappraised in light of new Retzius periodicities

OBJECTIVES

Among low-latitude apes, developmental defects of enamel often recur twice yearly, linkable to environmental cycles. Surprisingly, teeth of Homo naledi from Rising Star in South Africa (241-335 kya), a higher latitude site with today a single rainy season, also exhibit bimodally distributed hypoplastic enamel defects, but with uncertain timing and etiology. Newly determined Retzius periodicities for enamel formation in this taxon enable a reconstruction of the temporal patterning of childhood stress.

METHODS

Using high resolution casts of 31 isolated anterior teeth from H. naledi, 82 enamel defects (linear enamel hypoplasia [LEH]) were identified. Seventeen teeth are assigned to three individuals. Perikymata in the occlusal wall of enamel furrows and between the onsets of successive LEH were visualized with scanning electron microscopy and counted. Defects were measured with an optical scanner. Conversion of perikymata counts to estimates of LEH duration and inter-LEH interval draws upon Retzius periodicities of 9 and 11 days.

RESULTS

Anterior teeth record more than a year of developmental distress, expressed as two asymmetric intervals centered on 4.5 and 7.5 months bounded by three LEH. Durations, also, show bimodal distributions, lasting 3 or 12 weeks. Short duration LEH are more severe than long duration. Relative incisor/canine rates of formation are indistinguishable from modern humans.

DISCUSSION

We invoke a disease and dearth model, with short episodes of distress reflecting onset of disease in young infants, lasting about 3 weeks, followed by a season of undernutrition, possibly intensified by secondary plant compounds, spanning about 12 weeks, inferably coincident with austral winter.

Evolution of intermediate latency strategies in seasonal parasites

Traditional mechanistic trade-offs between transmission and parasite latency period length are foundational for nearly all theories on the evolution of parasite life-history strategies. Prior theoretical studies demonstrate that seasonal host activity can generate a trade-off for obligate-host killer parasites that selects for intermediate latency periods in the absence of a mechanistic trade-off between transmission and latency period lengths. Extensions of these studies predict that host seasonal patterns can lead to evolutionary bistability for obligate-host killer parasites in which two evolutionarily stable strategies, a shorter and longer latency period, are possible. Here we demonstrate that these conclusions from previously published studies hold for non-obligate host killer parasites. That is, seasonal host activity can select for intermediate parasite latency periods for non-obligate killer parasites in the absence of a trade-off between transmission and latency period length and can maintain multiple evolutionarily stable parasite life-history strategies. These results reinforce the hypothesis that host seasonal activity can act as a major selective force on parasite life-history evolution by extending the narrower prior theory to encompass a greater range of disease systems.

The second most abundant dinophyte in the ponds of a botanical garden is a species new to science

In the microscopy realm, a large body of dark biodiversity still awaits to be uncovered. Unarmoured dinophytes are particularly neglected here, as they only present inconspicuous traits. In a remote German locality, we collected cells, from which a monoclonal strain was established, to study morphology using light and electron microscopy and to gain DNA sequences from the rRNA operon. In parallel, we detected unicellular eukaryotes in ponds of the Botanical Garden Munich-Nymphenburg by DNA-metabarcoding (V4 region of the 18S rRNA gene), weekly sampled over the course of a year. Strain GeoK*077 turned out to be a new species of Borghiella with a distinct position in molecular phylogenetics and characteristic coccoid cells of ovoid shape as the most important diagnostic trait. Borghiella ovum, sp. nov., was also present in artificial ponds of the Botanical Garden and was the second most abundant dinophyte detected in the samples. More specifically, Borghiella ovum, sp. nov., shows a clear seasonality, with high frequency during winter months and complete absence during summer months. The study underlines the necessity to assess the biodiversity, particularly of the microscopy realm more ambitiously, if even common species such as formerly Borghiella ovum are yet unknown to science.

Does recovery after sport-related concussion vary by time point in a season? A multi-sport investigation

OBJECTIVE

Seasonality, or the specific point in time within a season in which the injury occurs, may have an impact on the recovery following sport-related concussions (SRCs). In a cohort of high school athletes across multiple sports, the authors sought to investigate the impact of seasonality on 1) concussion frequency, 2) acute symptom presentation (initial Post-Concussion Symptom Scale [PCSS] score), and 3) recovery outcomes, including the time to return to learn (RTL), symptom resolution (SR), and return to play (RTP).

METHODS

A retrospective, single-institution, cohort study was conducted with adolescent athletes aged 14-19 years who sustained an SRC between November 2017 and April 2022 and presented to a multidisciplinary specialty concussion clinic. The time from first practice to the end of the regular season was evenly trichotomized into early, middle, and late season. Teams that participated in the playoffs were included in a subanalysis. One-way ANOVA and independent t-tests were used to compare PCSS scores, RTL, SR, and RTP across seasonality. Univariable and multivariable regressions were used to determine predictors for recovery, defined as total days from initial visit to each outcome.

RESULTS

Of the 1504 eligible athletes, 620 high school athletes met inclusion criteria; 491 (79.2%) sustained a concussion during the regular season with 73 (14.9%), 136 (27.7%), and 282 (57.4%) concussions occurring in the early, middle, and late seasons, respectively. No differences were seen for initial PCSS score, RTL, SR, or RTP across early-, middle-, and late-season concussions. The initial PCSS score was significantly higher for playoff compared with regular-season concussions (playoffs: 33.4 ± 27.5; regular season: 23.3 ± 22.8; t = -1.979, p = 0.048). A subanalysis of playoff concussions (n = 24) compared with regular-season concussions showed that concussion in the playoffs was associated with a higher initial PCSS score in univariable (β = 0.093, p = 0.048) and multivariable (β = 0.112, p = 0.014) analyses.

CONCLUSIONS

The majority of concussions occurred during the late-season period. No difference in acute symptoms or recovery outcomes was seen when comparing the three regular season time points. Playoff concussions were associated with significantly increased symptom scores compared with nonplayoff concussions.

Climate change disrupts the seasonal coupling of plant and soil microbial nutrient cycling in an alpine ecosystem

The seasonal coupling of plant and soil microbial nutrient demands is crucial for efficient ecosystem nutrient cycling and plant production, especially in strongly seasonal alpine ecosystems. Yet, how these seasonal nutrient cycling processes are modified by climate change and what the consequences are for nutrient loss and retention in alpine ecosystems remain unclear. Here, we explored how two pervasive climate change factors, reduced snow cover and shrub expansion, interactively modify the seasonal coupling of plant and soil microbial nitrogen (N) cycling in alpine grasslands, which are warming at double the rate of the global average. We found that the combination of reduced snow cover and shrub expansion disrupted the seasonal coupling of plant and soil N-cycling, with pronounced effects in spring (shortly after snow melt) and autumn (at the onset of plant senescence). In combination, both climate change factors decreased plant organic N-uptake by 70% and 82%, soil microbial biomass N by 19% and 38% and increased soil denitrifier abundances by 253% and 136% in spring and autumn, respectively. Shrub expansion also individually modified the seasonality of soil microbial community composition and stoichiometry towards more N-limited conditions and slower nutrient cycling in spring and autumn. In winter, snow removal markedly reduced the fungal:bacterial biomass ratio, soil N pools and shifted bacterial community composition. Taken together, our findings suggest that interactions between climate change factors can disrupt the temporal coupling of plant and soil microbial N-cycling processes in alpine grasslands. This could diminish the capacity of these globally widespread alpine ecosystems to retain N and support plant productivity under future climate change.

Gene co-expression patterns in Atlantic salmon adipose tissue provide a molecular link among seasonal changes, energy balance and age at maturity

Sexual maturation in many fishes requires a major physiological change that involves a rapid transition between energy storage and usage. In Atlantic salmon, this transition for the initiation of maturation is tightly controlled by seasonality and requires a high-energy status. Lipid metabolism is at the heart of this transition since lipids are the main energy storing molecules. The balance between lipogenesis (lipid accumulation) and lipolysis (lipid use) determines energy status transitions. A genomic region containing a transcription co-factor of the Hippo pathway, vgll3, is the main determinant of maturation timing in Atlantic salmon. Interestingly, vgll3 acts as an inhibitor of adipogenesis in mice and its genotypes are potentially associated with seasonal heterochrony in lipid storage and usage in juvenile Atlantic salmon. Here, we explored changes in expression of more than 300 genes directly involved in the processes of adipogenesis, lipogenesis and lipolysis, as well as the Hippo pathway in the adipose tissue of immature and mature Atlantic salmon with distinct vgll3 genotypes. We found molecular evidence consistent with a scenario in which immature males with different vgll3 genotypes exhibit contrasting seasonal dynamics in their lipid profiles. We also identified components of the Hippo signalling pathway as potential major drivers of vgll3 genotype-specific differences in adipose tissue gene expression. This study demonstrates the importance of adipose gene expression patterns for directly linking environmental changes with energy balance and age at maturity through genetic factors bridging lipid metabolism, seasonality and sexual maturation.

Impact of Subgroup Distribution on Seasonality of Human Respiratory Syncytial Virus: A Global Systematic Analysis

BACKGROUND

Previous studies reported inconsistent findings regarding the association between respiratory syncytial virus (RSV) subgroup distribution and timing of RSV season. We aimed to further understand the association by conducting a global-level systematic analysis.

METHODS

We compiled published data on RSV seasonality through a systematic literature review, and unpublished data shared by international collaborators. Using annual cumulative proportion (ACP) of RSV-positive cases, we defined RSV season onset and offset as ACP reaching 10% and 90%, respectively. Linear regression models accounting for meteorological factors were constructed to analyze the association of proportion of RSV-A with the corresponding RSV season onset and offset.

RESULTS

We included 36 study sites from 20 countries, providing data for 179 study-years in 1995-2019. Globally, RSV subgroup distribution was not significantly associated with RSV season onset or offset globally, except for RSV season offset in the tropics in 1 model, possibly by chance. Models that included RSV subgroup distribution and meteorological factors explained only 2%-4% of the variations in timing of RSV season.

CONCLUSIONS

Year-on-year variations in RSV season onset and offset are not well explained by RSV subgroup distribution or meteorological factors. Factors including population susceptibility, mobility, and viral interference should be examined in future studies.

Diurnal temperature variation impacts energetics but not reproductive effort across seasons in a temperate dung beetle

Temperature varies on multiple timescales and ectotherms must adjust to these changes to survive. These adjustments may lead to energetic trade-offs between self-maintenance and reproductive investment. However, we know little about how diurnal and seasonal temperature changes impact energy allocation. Here we used a combination of empirical data and modeling of both thermoregulatory behaviors and body temperature to examine potential energetic trade-offs in the dung beetle Onthophagus taurus. Beginning in March 2020, universities and laboratories were officially closed due to the COVID-19 pandemic. We thus performed experiments at a private residence near Knoxville, Tennessee, USA, leveraging the heating, ventilation and air conditioning of the home to manipulate temperature and compare beetle responses to stable indoor temperatures versus variable outdoor temperatures. We collected O. taurus beetles in the early-, mid-, and late-breeding seasons to examine energetics and reproductive output in relation to diurnal and seasonal temperature fluctuations. We recorded the mass of field fresh beetles before and after a 24-h fast and used the resulting change in mass as a proxy for energetic costs of self-maintenance across seasons. To understand the impacts of diurnal fluctuations on energy allocation, we held beetles either indoors or outdoors for 14-day acclimation trials, fed them cow dung, and recorded mass change and reproductive output. Utilizing biophysical models, we integrated individual-level biophysical characteristics, microhabitat-specific performance, respirometry data, and thermoregulatory behaviors to predict temperature-induced changes to the allocation of energy toward survival and reproduction. During 24 h of outdoor fasting, we found that beetles experiencing reduced temperature variation lost more mass than those experiencing greater temperature variation, and this was not affected by season. By contrast, during the 14-day acclimation trials, we found that beetles experiencing reduced temperature variation (i.e., indoors) gained more mass than those experiencing greater temperature variation (i.e., outdoors). This effect may have been driven by shifts in the metabolism of the beetles during acclimation to increased temperature variation. Despite the negative relationship between temperature variation and energetic reserves, the only significant predictor of reproductive output was mean temperature. Taken together, we find that diurnal temperature fluctuations are important for driving energetics, but not reproductive output.

Environmental Risk Factors for Pediatric Epistaxis vary by Climate Zone

INTRODUCTION AND OBJECTIVE

Prior studies have provided variable results regarding environmental risk factors for epistaxis. These studies were conducted in varying climate zones, which may explain discrepancies in results. The objective of this study is to investigate correlations between season, temperature, and humidity on frequency of pediatric epistaxis across climate zones.

METHODS

Children seen in the outpatient setting for epistaxis were identified from the 2007-2010 IBM MarketScan database. Climate zones were assigned according to International Energy Conservation Code (IECC) classification, where temperature zones in the United States and territories were assigned on an ordinal scale from 1 (tropical) to 8 (subarctic), and humidity zones were categorized as moist, dry, or marine. The control population was a sample of all well-child visits matched by age and county.

RESULTS

We identified 184,846 unique children seen for epistaxis and 1,897,012 matched controls. Moderate temperature zones were associated with lower odds of epistaxis compared with the hottest and coldest zones. Humidity was associated inversely with epistaxis rates in moderate temperature zones but was not a significant predictor of epistaxis in climates with extreme heat. Additionally, summer was associated with lower odds of epistaxis compared to winter. Interestingly, however, there were significantly higher rates of cautery procedures during summer months, driven largely by increased procedures performed in clinic, as opposed to the operating room or emergency room.

CONCLUSIONS

Environmental risk factors for epistaxis vary by climate zone. The model presented reconciles prior reports and may allow for more personalized clinical management based on regional climate.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:1450-1456, 2024.

Change in water quality in an Amazonian microbasin: ecological and human health implications

The decline in the quality of water resources in the Amazon is very rapid in cities suffering from unplanned urban growth. The region has two defined seasons, winter (wet) and summer (dry), which directly affect the behavior of contaminants in aquatic ecosystems. The aim of this study was to assess the ecological and human health risks associated with the use of the watershed. In addition, an ecological index was proposed: the Quality Index for Aquatic Life, for the risk of contaminants to aquatic life. Sampling was carried out at six points in the Juá watershed. Physicochemical parameters, major anions, metals and total phosphorus were analyzed at both stations between 2020 and 2021. The highest concentrations of contaminants were found in the rainy season, due to the washing away of the banks. In this sense, Cl presented a concentration more than 307 times higher than that permitted by Brazilian legislation (wet). The ecological index showed that the watershed has a high risk of metals such as Cr III and Cr VI for the biota. The human health risk analysis showed a low risk; however, the lack of basic sanitation in the city indicates that monitoring of urban water resources is necessary.

Consistent seasonal flexibility of the gut and its regions across wild populations of a winter-quiescent fish

Seasonality in north-temperate environments imposes drastic temperature and resource variations that shape the seasonal ecophysiology of resident organisms. A better understanding of an organism's capacity to flexibly respond to this drastic seasonal variation may reveal important mechanisms for tolerating or responding to environmental variation introduced by global change. In fishes, the digestive system is both the interface between resource and energy acquisition and one of the most expensive organ systems to maintain. However, little evidence describing the capacity for seasonal flexibility in the digestive tract of wild northern fishes exists. Here, we investigated phenotypic flexibility in the size of the gastrointestinal (GI) tract across three northern populations of a winter-dormant warm-water fish, pumpkinseed sunfish (Lepomis gibbosus). In all populations, pumpkinseed exhibited pronounced structural flexibility in the GI tract, aligned with winter and the timing of reproduction. The dry mass of the GI increased by 1.3- to nearly 2.5-fold in the early spring. The pyloric caeca demonstrated the greatest capacity for flexibility, increasing by up to 3.7-fold prior to reproduction. In all populations, minimum dry GI mass was consistently achieved during winter and mid-summer. This capacity for gut flexibility may represent a novel mechanism for facilitating rapid adaptive responses (e.g. metabolic plasticity) to future environmental change.

Vernal growth of vocal control nucleus Area X, but not HVC, precedes gonadal recrudescence in wild black-capped chickadees (Poecile atricapillus)

In temperate-zone songbirds, the neuroanatomical changes which occur in advance of breeding, including the growth of nuclei of the vocal control system, are believed to occur downstream of gonadal recrudescence. However, evidence from wild birds is mixed. Here, we captured black-capped chickadees from the wild in early spring (March-April), summer (August-September), and winter (December-January); in addition to measuring the volumes of two vocal control nuclei (Area X and HVC), we also quantified two indicators of reproductive state (gonads and circulating gonadal steroids). Most birds captured in early spring had regressed gonads and low levels of circulating gonadal steroids, indicating these birds were not yet in full breeding condition. However, these early spring birds still had a significantly larger Area X than winter birds, while HVC did not differ in size across groups. Using data from a previously published seasonal study of black-capped chickadees (Phillmore et al., Developmental Neurobiology, 2015;75:203-216), we then compared Area X and HVC volumes from our early spring group to a breeding group of chickadees captured 3-4 weeks later in the spring. While Area X volume did not differ between the studies, breeding males in Phillmore et al. (2015) had a significantly larger HVC. Taken together, this suggests that the vernal growth of Area X occurs ahead of HVC in black-capped chickadees, and that the overall vernal changes in the vocal control system occur at least partially in advance of the breeding-associated upregulation of the hypothalamic-pituitary-gonadal axis.

Trends in healthcare utilization by patients with gout: A cross-sectional study using Health Insurance Review and Assessment Service data

This study aimed to analyze the distribution of gout patients and the utilization of healthcare services in South Korea to provide valuable recommendations to clinicians and policymakers. A cross-sectional study was conducted. Claims data from the Health Insurance Review and Assessment Service spanning 2010 to 2019 were utilized, and a sample of 69,680 patients was included in the study. The incidence of gout was observed to be high in male patients over the age of 40, with most patients receiving outpatient care for gout management. Nonsteroidal anti-inflammatory drugs and urate-lowering agents were the most frequently prescribed medications, with prescriptions for colchicine and febuxostat increasing among urate-lowering agents. Musculoskeletal disorders were found to be the most common comorbidities among gout patients. Although the total costs of gout management increased, there was no significant increase in cost per patient. This study provides insights into the current state of healthcare utilization for gout patients in South Korea and trends in the disease burden and use of medications. The findings have crucial implications for clinicians and policymakers involved in decision-making regarding the management and treatment of gout.

A cosmopolitan inversion facilitates seasonal adaptation in overwintering Drosophila

Fluctuations in the strength and direction of natural selection through time are a ubiquitous feature of life on Earth. One evolutionary outcome of such fluctuations is adaptive tracking, wherein populations rapidly adapt from standing genetic variation. In certain circumstances, adaptive tracking can lead to the long-term maintenance of functional polymorphism despite allele frequency change due to selection. Although adaptive tracking is likely a common process, we still have a limited understanding of aspects of its genetic architecture and its strength relative to other evolutionary forces such as drift. Drosophila melanogaster living in temperate regions evolve to track seasonal fluctuations and are an excellent system to tackle these gaps in knowledge. By sequencing orchard populations collected across multiple years, we characterized the genomic signal of seasonal demography and identified that the cosmopolitan inversion In(2L)t facilitates seasonal adaptive tracking and shows molecular footprints of selection. A meta-analysis of phenotypic studies shows that seasonal loci within In(2L)t are associated with behavior, life history, physiology, and morphological traits. We identify candidate loci and experimentally link them to phenotype. Our work contributes to our general understanding of fluctuating selection and highlights the evolutionary outcome and dynamics of contemporary selection on inversions.

Seasonality and Genotype Diversity of Human Rhinoviruses during an Eight-Year Period in Slovenia

Due to the high socioeconomic burden of rhinoviruses, the development of prevention and treatment strategies is of high importance. Understanding the epidemiological and clinical features of rhinoviruses is essential in order to address these issues. Our study aimed to define the seasonality and molecular epidemiology of rhinoviruses in Slovenia. Over a period of eight years, a total of 20,425 patients from sentinel primary healthcare settings and sentinel hospitals were examined for a panel of respiratory viruses in the national programme for the surveillance of influenza-like illnesses and acute respiratory infections. The patients were from all age groups and had respiratory infections of various severity. Infection with a rhinovirus was confirmed using an RT-rPCR in 1834 patients, and 1480 rhinoviruses were genotyped. The molecular analysis was linked to demographical and meteorological data. We confirmed the year-round circulation of rhinoviruses with clear seasonal cycles, resulting in two seasonal waves with peaks in spring and autumn. High levels of genotype variability and co-circulation were confirmed between and within seasons and were analysed in terms of patient age, the patient source reflecting disease severity, and meteorological factors. Our study provides missing scientific information on the genotype diversity of rhinoviruses in Slovenia. As most previous investigations focused on exclusive segments of the population, such as children or hospitalised patients, and for shorter study periods, our study, with its design, size and length, contributes complementary aspects and new evidence-based knowledge to the regional and global understanding of rhinovirus seasonality and molecular epidemiology.

Peak timing of slowest growth velocity among young children coincides with highest ambient temperatures in Burkina Faso: a longitudinal study

BACKGROUND

Seasonal cycles in climatic factors affect drivers of child growth and contribute to seasonal fluctuations in undernutrition. Current growth seasonality models are limited by categorical definitions of seasons that rely on assumptions about their timing and fail to consider their magnitude.

OBJECTIVE

We disentangle the relationship between climatic factors and growth indicators, using harmonic regression to determine how child growth is related to peaks in temperature, precipitation, and vegetation.

METHODS

Longitudinal anthropometric data collected between August 2014 and December 2016 from 5039 Burkinabè children measured monthly from age 6 to 28 mo (108,580 observations) were linked with remotely sensed daily precipitation, vegetation, and maximum air temperature. Our models parsimoniously extract a cyclic signal with multiple potential peaks, to compare the magnitude and timing of seasonal peaks in climatic factors and morbidity with that of nadirs in growth velocity (cm/mo, kg/mo).

RESULTS

Length and weight velocity were slowest twice a year, coinciding both times with the highest temperatures, and peak fever incidence. Length velocity is slowest 13 d after the first temperature peak in April, and 5 d after the second. Similarly, weight velocity is slowest 13 d before the first temperature peak, and 11 d before the second. The statistical relationship between temperature and anthropometry shows that when the current temperature is higher, weight velocity is lower (β = -0.0048; 95% CI: -0.0059, -0.0038), and length velocity is higher (β = 0.0088; 95% CI: 0.0070, 0.0105).

CONCLUSIONS

Results suggest that child health and development are more affected by high temperatures than by other aspects of climatic seasonality such as rainfall. Emerging shifts in climatic conditions will pose challenges to optimal growth, highlighting the importance of changes that optimize the timing of nutrition interventions and address environmental growth-limiting conditions.

CLINICAL TRIAL REGISTRY

Clinicaltrials.gov: NCT02071563.

Season-specific impacts of climate change on canopy-forming seaweed communities

Understory assemblages associated with canopy-forming species such as trees, kelps, and rockweeds should respond strongly to climate stressors due to strong canopy-understory interactions. Climate change can directly and indirectly modify these assemblages, particularly during more stressful seasons and climate scenarios. However, fully understanding the seasonal impacts of different climate conditions on canopy-reliant assemblages is difficult due to a continued emphasis on studying single-species responses to a single future climate scenario during a single season. To examine these emergent effects, we used mesocosm experiments to expose seaweed assemblages associated with the canopy-forming golden rockweed, Silvetia compressa, to elevated temperature and pCO2 conditions reflecting two projected greenhouse emission scenarios (RCP 2.6 [low] & RCP 4.5 [moderate]). Assemblages were grown in the presence and absence of Silvetia, and in two seasons. Relative to ambient conditions, predicted climate scenarios generally suppressed Silvetia biomass and photosynthetic efficiency. However, these effects varied seasonally-both future scenarios reduced Silvetia biomass in summer, but only the moderate scenario did so in winter. These reductions shifted the assemblage, with more extreme shifts occurring in summer. Contrarily, future scenarios did not shift assemblages within Silvetia Absent treatments, suggesting that climate primarily affected assemblages indirectly through changes in Silvetia. Mesocosm experiments were coupled with a field Silvetia removal experiment to simulate the effects of climate-mediated Silvetia loss on natural assemblages. Consistent with the mesocosm experiment, Silvetia loss resulted in season-specific assemblage shifts, with weaker effects observed in winter. Together, our study supports the hypotheses that climate-mediated changes to canopy-forming species can indirectly affect the associated assemblage, and that these effects vary seasonally. Such seasonality is important to consider as it may provide periods of recovery when conditions are less stressful, especially if we can reduce the severity of future climate scenarios.

Parechovirus A Circulation and Testing Capacities in Europe, 2015-2021

Parechovirus infections usually affect neonates and young children; manifestations vary from asymptomatic to life-threatening. We describe laboratory capacity in Europe for assessing parechovirus circulation, seasonality, and epidemiology. We used retrospective anonymized data collected from parechovirus infection case-patients identified in Europe during January 2015-December 2021. Of 21 laboratories from 18 countries that participated in the study, 16 (76%) laboratories with parechovirus detection capacity reported 1,845 positive samples; 12/16 (75%) with typing capability successfully identified 517 samples. Parechovirus A3 was the most common type (n = 278), followed by A1 (153), A6 (50), A4 (13), A5 (22), and A14 (1). Clinical data from 1,269 participants highlighted correlation of types A3, A4, and A5 with severe disease in neonates. We observed a wide capacity in Europe to detect, type, and analyze parechovirus data. To enhance surveillance and response for PeV outbreaks, sharing typing protocols and data on parechovirus-positive cases should be encouraged.

Does the effectiveness of biological medications in the treatment for psoriasis depend on the moment of starting therapy? A preliminary study

Introduction

It is well known that biological medications acting on selected elements of the immune response are highly effective in psoriasis treatment. It is a common perception that psoriasis is a seasonal disorder with improvement in warmer months, however it has not been unequivocally confirmed. It is not known whether the time of year of starting systematic therapy for psoriasis influences treatment outcomes.

Material and methods

Changes in psoriasis severity scores during treatment with biologics were investigated. The scores were recorded for 62 patients with moderate to severe psoriasis at the beginning, after 1, 4 and 7 months of the therapy. Patients were divided into two groups: those beginning the treatment in the cold period of the year (November-March) and in the warm period (May-September). The seasonal groups were also divided into subgroups according to the type of biologics used: interleukin inhibitors and tumor necrosis factor α (TNF-α) inhibitors. Results of the treatment were analysed using standard statistical tests of differences between samples.

Results

After 1 and 4 months of the therapy, better efficacy of interleukin inhibitors was found in patients starting treatment in summer. The course of psoriasis improvement in patients taking TNF-α inhibitors resulted in consistent improvement regardless of the season. The outcome of the treatment after 7 months was similar for both seasonal groups and types of biologics used.

Conclusions

Our understanding of the effectiveness of the treatments depending on the time of the year combined with the type of biologics used, may further improve results of the therapy.

Seasonal migration alters energetic trade-off optimization and shapes life history

Trade-offs between current and future reproduction manifest as a set of co-varying life history and metabolic traits, collectively referred to as 'pace of life' (POL). Seasonal migration modulates environmental dynamics and putatively affects POL, however, the mechanisms by which migratory behaviour shapes POL remain unclear. We explored how migratory behaviour interacts with environmental and metabolic dynamics to shape POL. Using an individual-based model of movement and metabolism, we compared fitness-optimized trade-offs among migration strategies. We found annual experienced seasonality modulated by migratory movements and distance between end-points primarily drove POL differentiation through developmental and migration phenology trade-offs. Similarly, our analysis of empirically estimated metabolic data from 265 bird species suggested seasonal niche tracking and migration distance interact to drive POL. We show multiple viable life-history strategies are conducive to a migratory lifestyle. Overall, our findings suggest metabolism mediates complex interactions between behaviour, environment and life history.

Helminth ecological requirements shape the impact of climate change on the hazard of infection

Outbreaks and spread of infectious diseases are often associated with seasonality and environmental changes, including global warming. Free-living stages of soil-transmitted helminths are highly susceptible to climatic drivers; however, how multiple climatic variables affect helminth species, and the long-term consequences of these interactions, is poorly understood. We used experiments on nine trichostrongylid species of herbivores to develop a temperature- and humidity-dependent model of infection hazard, which was then implemented at the European scale under climate change scenarios. Intestinal and stomach helminths exhibited contrasting climatic responses, with the former group strongly affected by temperature while the latter primarily impacted by humidity. Among the demographic traits, larval survival heavily modulated the infection hazard. According to the specific climatic responses of the two groups, climate change is expected to generate differences in the seasonal and spatial shifts of the infection hazard and group co-circulation. In the future, an intensification of these trends could create new opportunities for species range expansion and co-occurrence at European central-northern latitudes.

Time-varying habitat selection analysis: A model and applications for studying diel, seasonal, and post-release changes

Resource selection functions are commonly used to evaluate animals' habitat selection, for example, the disproportionate use of habitats relative to their availability. While environmental conditions or animal motivations may vary over time, sometimes in an unknown manner, studying changes in habitat selection usually requires an a priori segmentation of time in distinct periods. This limits our ability to precisely answer the question "When is an animal's habitat selection changing?" Here, we present a straightforward and flexible alternative approach based on fitting dynamic logistic models to used/available data. First, using simulated datasets, we demonstrate that dynamic logistic models perform well in recovering temporal variations in habitat selection. We then show real-world applications for studying diel, seasonal, and post-release changes in the habitat selection of the blue wildebeest (Connochaetes taurinus). Dynamic logistic models allow the study of temporal changes in habitat selection in a framework consistent with resource selection functions but without the need to segment time in distinct periods, which can be a difficult task when little is known about the process studied or may obscure interindividual variability in timing of change. These models should undoubtedly find their place in the movement ecology toolbox. We provide R scripts to facilitate their adoption. We also encourage future research to focus on how to account for temporal autocorrelation in location data, as this would allow statistical inference from location data collected at a high frequency, an increasingly common situation.

Ecotype-Specific and Correlated Seasonal Responses of Biomass Production, Non-Structural Carbohydrates, and Fatty Acids in Zostera marina

Seagrasses, which are marine flowering plants, provide numerous ecological services and goods. Zostera marina is the most widely distributed seagrass in temperate regions of the northern hemisphere, tolerant of a wide range of environmental conditions. This study aimed to (i) examine seasonal trends and correlations between key seagrass traits such as biomass production and biochemical composition, and (ii) compare seasonal adaptation of two ecotypes of Z. marina exposed to similar environmental conditions on the west coast of Ireland. During summer, plants accumulated higher levels of energetic compounds and levels of unsaturated fatty acids (FAs) decreased. Conversely, the opposite trend was observed during colder months. These findings indicate a positive seasonal correlation between the production of non-structural carbohydrates and saturated fatty acids (SFAs), suggesting that seagrasses accumulate and utilize both energetic compounds simultaneously during favorable and unfavorable environmental conditions. The two ecotypes displayed differential seasonal responses by adjusting plant morphology and production, the utilization of energetic reserves, and modulating unsaturation levels of fatty acids in seagrass leaves. These results underscore the correlated seasonal responses of key compounds, capturing ecotype-specific environmental adaptations and ecological strategies, emphasizing the robust utility of these traits as a valuable eco-physiological tool.

Seasonal Variations in 25-Hydroxyvitamin D Levels among Pediatric Patients Attending the Healthcare Centre

Vitamin D plays an essential role in maintaining bone density, building the immune system, and regulating cell growth alongside other key biological functions. Limited data are available about the seasonal variation in vitamin D levels in the pediatric population in Saudi Arabia. This study aimed to investigate the seasonal influence on the pediatric circulating levels of 25(OH)D. A total of 1790 pediatric outpatients who visited the University healthcare centre were included in this study. Overall, there was a noticeably high prevalence (69%) of both combined 25(OH)D deficiency and insufficiency. The highest mean serum concentration of 25(OH)D was recorded in summer (29 ng/mL) and autumn (27 ng/mL). The deficient and insufficient categories were predominant, accounting for 33% and 36%, respectively. Comparable patterns were recorded during autumn, winter, and spring. Interestingly, the 25(OH)D level was significantly associated with the four seasons (p = 0.001), with females having a higher prevalence of 25(OH)D deficiency in the spring and summer than males. Furthermore, only in autumn and winter, we found a significant association between gender and 25(OH)D status (p < 0.001 for both). Another association between nationality and the circulating levels 25(OH)D was found during autumn and winter (p < 0.001 and p = 0.01), respectively. In all seasons, age had a negative impact on serum (OH)D levels. However, this relationship was statistically significant (p < 0.05) only in summer, autumn, and winter. Gender was a significant predictor, with 25(OH)D levels in autumn and winter and an odds ratio of 1.67 in autumn and 2 in winter, indicating that being men had a positive influence on circulating 25(OH)D levels. There were highly significant differences in 25(OH)D concentrations among different age categories. The Saudi population experiences low levels of vitamin D, particularly in autumn and winter periods. This study showed that seasonality, age category, nationality, and gender influence vitamin D status, suggesting the need for tailored intervention and monitoring of 25(OH)D status to reach adequate levels of vitamin D. Healthcare practitioners and policymakers may consider the interplay between age, nationality, gender, and seasonal variations when addressing vitamin D status and a targeted supplementation approach for high-risk groups that may develop health issues.

Seasonal Diet Changes and Trophic Links of Cold-Water Fish (Coregonus albula) within a Northern Lake Ecosystem

The seasonal feeding patterns of the cold-adapted fish, Coregonus albula, are poorly studied in high-latitude lakes but could provide insight for predicting the effects of global warming. We examined vendace's diet composition, traced the carbon and nitrogen isotope ratios from producers to consumers in the food web, and estimated vendace's trophic position in a subarctic lake (the White Sea basin). Results showed the vendace to be a typical euryphagous fish, but clear seasonal differences were found in the relative importance of plankton and benthos in the diet. The vendace consumed primarily benthic amphipods in the summer, planktonic cladocerans in the autumn, and copepods in the winter-spring (under ice); larvae of aquatic insects were the second-most important food items throughout the year. Because of the substantial proportion of fish embryos in its diet, the vendace had a trophic position similar to that of a predatory fish (perch). The Bayesian food source-mixing model revealed that the majority of vendace energy derives from planktonic copepods. The dominant Cyclops had the lowest carbon isotope values, suggesting a carbon-depleted diet typical for methanotrophic bacteria, as its probable food source was in a lake under ice. Understanding the feeding patterns of vendace provides information to better predict the potential biotic effects of environmental change on lake ecosystems.

Incidence of central retinal artery occlusion peaks in winter season

Introduction

Stroke incidence exhibits seasonal trends, with the highest occurrences observed during winter. This study investigates the incidence of central retinal artery occlusion (CRAO), a stroke equivalent of the retina, and explores its monthly and seasonal variations, as well as potential associations with weather and ambient air pollutants.

Methods

A retrospective search of medical records spanning 15 years (January 2008-December 2022) was conducted at the University Eye Hospital Tübingen, Germany, focusing on diagnosed cases of CRAO. Incidences were evaluated on a monthly and seasonal basis (winter, spring, summer, fall). Weather data (temperature, precipitation, atmospheric pressure) and concentrations of ambient air pollutants [fine particulate matter (PM2.5), coarse particulate matter (PM10), nitrogen dioxide (NO2), and ozone (O3)], were analyzed for a potential association with CRAO incidence.

Results

Out of 432 patients diagnosed with CRAO between 2008 and 2022, significantly varying incidences were observed monthly (p = 0.025) and seasonally (p = 0.008). The highest rates were recorded in February and winter, with the lowest rates in June and summer. Concentrations of NO2, PM2.5 and lower ambient air temperature (average, minimum, maximum) showed significant correlations with CRAO incidence.

Discussion

This comprehensive 15-year analysis reveals a pronounced winter peak in CRAO incidence, with the lowest occurrences in summer. Potential associations between CRAO incidence and ambient air pollutants and temperature underscore the importance of considering seasonal trends and call for further investigations to elucidate contributing factors, potentially leading to targeted preventive strategies and public health interventions.

Seasonal variations for newly prescribed urate-lowering drugs for asymptomatic hyperuricemia and gout in Japan

Background: Urate-lowering drugs (ULDs) have been approved for treatment of asymptomatic hyperuricemia and gout in Japan. Although serum urate levels and rates of gout onset are known to have seasonal variations, no survey results regarding the seasonality of ULD prescriptions for asymptomatic hyperuricemia and gout have been reported. Methods: A large-scale database of medical claims in Japan filed between January 2019 and December 2022 was accessed. In addition to total size of the recorded population for each month examined, the numbers of patients every month with newly prescribed ULDs for asymptomatic hyperuricemia and gout were noted, based on the International Classification of Diseases, 10th Revision, codes E79.0 and M10. Results: The results identified 201,008 patients with newly prescribed ULDs (median age 49.0 years, male 95.6%). Of those, 64.0% were prescribed ULDs for asymptomatic hyperuricemia and 36.0% for gout. The proportion of new ULD prescriptions was seasonal, with that significantly (p < 0.001) higher in summer (June-August) [risk ratio (RR) 1.322, 95% CI 1.218 to 1.436] and autumn (September-November) (RR 1.227, 95% CI 1.129-1.335) than in winter (December-February), whereas the proportion in spring (March-May) was not significantly different from winter. There was no significant difference after stratification by drug type (uric acid production inhibitor/uricosuric agent) or size of the medical institution, nor subgrouping by age or sex (p for interaction = 0.739, 0.727, 0.886, and 0.978, respectively). On the other hand, the proportions of new ULD prescriptions for asymptomatic hyperuricemia were significantly lower and for gout significantly higher in spring than winter, while those were similar in summer and autumn for both groups (p for interaction<0.001). Conclusion: The present findings indicate that new prescriptions for ULDs to treat asymptomatic hyperuricemia or gout in Japan show seasonal differences, with higher rates noted in summer and autumn as compared to winter.

Application of New Filling Material Based on Combined Heat and Power Waste for Sewage Treatment in Constructed Wetlands

The filling of constructed wetlands (CWs) affects the efficiency of sewage treatment and proper operation. Mineral aggregates are most often used as filling materials. Significant environmental burdens from mineral mining operations justify the search for waste fill. This study aimed to determine the possibility of increasing the efficiency of CW by using a Certyd aggregate as a new filling. Certyd is produced in the sintering process of coal ash, a waste from combined heat and power (CHP) plant operation. Comprehensive two-year studies were conducted using two real-scale subsurface vertical flow (SS VF) CWs supplied with domestic sewage. One bed was filled with a Certyd and the other was filled with appropriate fractions of a mineral aggregate. Both beds worked in parallel, and to compare their effectiveness, account seasonality was taken into account. The SS-VF Certyd-filled bed achieved an average efficiency of 88.0% for biological oxygen demand (BOD5), 80.2% for chemical oxygen demand (COD), 80.4% for suspended solids (SSs), 80.2 for ammonia nitrogen (N-NH4), 72.2% for total nitrogen (TN), and 55.3% for total phosphorus (TP), while the gravel-filled bed achieved 84.5%, 77.0%, 86.9%, 74.2%, 69.4%, and 57.8% for the whole research period, respectively. A higher effect of the removed unit load was achieved in the bed filled with Certyd (36.2 g BOD5 m-2 d-1, 50.0 g COD m-2 d-1, 5.88 g SS m-2 d-1, 7.1 g TN m-2 d-1, 7.9 g N-NH4 m-2 d-1, 0.79 g TP m-2 d-1) compared to the gravel-filled bed (34.7 g BOD5 m-2 d-1, 47.0 g COD, 6.35 g SS m-2 d-1, 6.9 g TN m-2 d-1, 7.3 g m-2 d-1 N-NH4, 0.83 g TP m-2 d-1).

Spatio-temporal variability in transmission risk of human schistosomes and animal trematodes in a seasonally desiccating East African landscape

Different populations of hosts and parasites experience distinct seasonality in environmental factors, depending on local-scale biotic and abiotic factors. This can lead to highly heterogeneous disease outcomes across host ranges. Variable seasonality characterizes urogenital schistosomiasis, a neglected tropical disease caused by parasitic trematodes (Schistosoma haematobium). Their intermediate hosts are aquatic Bulinus snails that are highly adapted to extreme rainfall seasonality, undergoing prolonged dormancy yearly. While Bulinus snails have a remarkable capacity for rebounding following dormancy, we investigated the extent to which parasite survival within snails is diminished. We conducted an investigation of seasonal snail schistosome dynamics in 109 ponds of variable ephemerality in Tanzania from August 2021 to July 2022. First, we found that ponds have two synchronized peaks of schistosome infection prevalence and observed cercariae, though of lower magnitude in the fully desiccating than non-desiccating ponds. Second, we evaluated total yearly schistosome prevalence across an ephemerality gradient, finding ponds with intermediate ephemerality to have the highest infection rates. We also investigated dynamics of non-schistosome trematodes, which lacked synonymity with schistosome patterns. We found peak schistosome transmission risk at intermediate pond ephemerality, thus the impacts of anticipated increases in landscape desiccation could result in increases or decreases in transmission risk with global change.

Age-dependent seasonality in the incidence of stroke: A 21-year population-based study

INTRODUCTION

Seasonality in the incidence of stroke has been examined in numerous studies, yet data on whether it differs with age are limited. To fill this gap, we utilized a largescale dataset from Israel.

PATIENTS AND METHODS

We retrieved data of all hospitalizations for ischemic stroke (IS), transient ischemic attack (TIA) and intra cerebral hemorrhage (ICH) from 2000 to 2020. We maintained separate datasets for IS/TIA and ICH, divided into five age groups: 18-49, 50-59, 60-69, 70-79, and 80+. We modeled the monthly incidence using a generalized additive model. The seasonal effect was defined by the rate ratio (RR) of each month compared to the annual mean.

RESULTS

The analysis included 317,586 and 23,789 events of IS/TIA and ICH respectively. We found an interaction between age and seasonality, accounting for a phase shift with age in the seasonal pattern of IS/TIA incidence. For cases under 70 years, the peak was during summertime and the RRs increased with decreasing age, reaching 1.11 (95% CI 1.09-1.13) at the youngest age group. In contrast, among the elderly, a winter peak was observed and the RRs increased with age to 1.07 (95% CI 1.06-1.08) at the oldest age group. For ICH, a winter/autumn peak was identified and the RRs increased with age to 1.20 (95% CI 1.16-1.24).

CONCLUSIONS

Our finding of age-dependent seasonal patterns in the occurrence of stroke, suggests closer monitoring of cardiovascular risk factors during wintertime among elderly individuals. The mechanism governing the seasonal phase shift with age in IS/TIA incidence, requires further investigation.

Seasonal variation in the biological succession of marine diatoms over 316L stainless steel in a coastal environment of Chile

Characterizing seasonal changes in diatom community profiles in coastal environments is scarce worldwide. Despite diatoms being prevalent in microfouling, their role in microbially influenced corrosion of metallic materials remains poorly understood. This study reports the effect of seasonal variations on the settlement of marine diatoms and corrosion of 316 L stainless steel surfaces exposed to Chilean coastal seawater. Electron microscopy imaging revealed a diverse assembly of diatoms, exhibiting pronounced differences at genus level between summer and winter seasons, with a significant delay in diatom settlement during winter. Electrochemical measurements indicated an active role of diatoms in increasing corrosion current during biofilm development. While the final diatom composition was similar irrespective of the season, the analyses of diatom assemblages over time differed, showing faster colonization when silicate and nitrate were available. This study lays the foundation for future research on the dominant season-specific genera of diatoms to unveil the microbial interactions that could contribute to corrosion and to evaluate their potential as bioindicators for alternative surveillance strategies.

Chytrid infections exhibit historical spread and contemporary seasonality in a declining stream-breeding frog

Species with extensive geographical ranges pose special challenges to assessing drivers of wildlife disease, necessitating collaborative and large-scale analyses. The imperilled foothill yellow-legged frog (Rana boylii) inhabits a wide geographical range and variable conditions in rivers of California and Oregon (USA), and is considered threatened by the pathogen Batrachochytrium dendrobatidis (Bd). To assess drivers of Bd infections over time and space, we compiled over 2000 datapoints from R. boylii museum specimens (collected 1897-2005) and field samples (2005-2021) spanning 9° of latitude. We observed a south-to-north spread of Bd detections beginning in the 1940s and increase in prevalence from the 1940s to 1970s, coinciding with extirpation from southern latitudes. We detected eight high-prevalence geographical clusters through time that span the species' geographical range. Field-sampled male R. boylii exhibited the highest prevalence, and juveniles sampled in autumn exhibited the highest loads. Bd infection risk was highest in lower elevation rain-dominated watersheds, and with cool temperatures and low stream-flow conditions at the end of the dry season. Through a holistic assessment of relationships between infection risk, geographical context and time, we identify the locations and time periods where Bd mitigation and monitoring will be critical for conservation of this imperilled species.

Evaluating enteric methane emissions within a herd of genetically divergent grazing dairy cows

Enteric methane (CH4) emissions of 3 genetic groups (GG) of dairy cows were recorded across the grazing season (early March to late October). The 3 GG were (1) high economic breeding index (EBI) Holstein-Friesian (HF) representative of the top 1% of dairy cows in Ireland at the time of the study (elite), (2) national average (NA) EBI, which were representative of the average HF dairy cow in Ireland, and (3) purebred Jersey (JE) cows. Enteric CH4 was recorded using GreenFeed technology. Seasonal variation in CH4 was observed, with the lowest daily CH4 emissions and CH4 expressed per unit of dry matter intake occurring in spring (253 g/d and 15.56 g/kg, respectively), intermediate in summer (303 g/d and 18.26 g/kg, respectively), and greatest in autumn (324 g/d and 19.80 g/kg, respectively). Seasonal variation was also observed in the proportion of gross energy intake converted to CH4 (Ym); in the spring the Ym was lowest at 0.046, increasing to 0.053 and 0.058 in the summer and autumn, respectively. There was no difference in daily CH4 between the elite and NA, whereas JE had lower CH4 emissions compared with the elite. When expressed per unit of milk solids (fat + protein yield; MS), the elite and JE produced 6.8% and 9.7% less CH4 per kilogram of MS, respectively, compared with NA. There was no difference between the GG for CH4 per unit of DMI or the Ym. This research emphasizes the variation in CH4 emissions across the grazing season and among cows of differing genetic merit for CH4 emission intensities but not for CH4 per unit of DMI or the Ym.

Impact of a Homestead Food Production Program on Dietary Diversity: Seasonal and Annual Results from the Cluster-Randomized FAARM Trial in Sylhet, Bangladesh

BACKGROUND

Rice-predominant diets are common in Bangladesh, leading to widespread nutritional deficiencies. The Food and Agricultural Approaches to Reducing Malnutrition (FAARM) cluster-randomized controlled trial in rural Sylhet, Bangladesh evaluated a homestead food production intervention implemented 2015-2018 through Helen Keller International, aiming to improve child growth.

OBJECTIVES

We estimated the intervention's impact on women's and children's dietary diversity, a secondary trial objective.

METHODS

We collected dietary diversity throughout the trial (March 2015 to June 2020) at multiple times each year using standard, United Nations-endorsed, self-reported measures for women (10-food group scale) and children (7-food group scale). We included 28,282 observations of 2701 women (out of 2705 enrolled) and 17,445 observations of their 3257 children (aged 6-37 mo) in 96 settlements, 48 of which received the intervention. We estimated the intervention's impact on dietary diversity by year of intervention, overall periods following the start of the intervention, and seasonally, using multilevel regression with the control group as the counterfactual, controlling for seasonality, baseline dietary diversity, and clustering by settlement and repeated measures.

RESULTS

At baseline, approximately one-third of women and children consumed a minimally diverse diet. Over the entire intervention and postintervention period, women's and children's odds of consuming a minimally diverse diet nearly doubled (odds ratio [OR] 1.8, P < 0.001, for both). This benefit was barely present in the first year, increased in the second, and peaked in the last intervention year (OR 2.4 for women, OR 2.5 for children, both P < 0.001) before settling at around double the odds in postintervention years (P < 0.001). Dietary improvement was observed throughout the year for both women and children with incremental increases in nearly all food groups.

CONCLUSIONS

The nutrition-sensitive agriculture intervention successfully increased dietary diversity in women and children, and these impacts persisted after the project closed, including during the early COVID 19 lockdown period. This trial was registered at clinicaltrials.gov as NCT02505711.

Seasonal Variation in Detection of Haemosporidia in a Bird Community: A Comparison of Nested PCR and Microscopy

In a 2-yr study on prevalence of Haemosporidia in an avian community in Ithaca, New York, USA, we tested the hypothesis that apparent seasonal variation in prevalence is influenced by the detection protocol. We confirmed a higher detection of Haemosporidia using a molecular diagnosis technique (PCR) than by microscopy; this further increased when the PCR test was triplicated. Microscopic examination and PCR techniques have different specificity and sensitivity and therefore different probabilities of detecting hemoparasites. Birds with chronic infections or sampled during winter often have very low parasitemia, and such infections may be missed by microscopy but detected by PCR. Haemosporidian prevalence was higher during the breeding season than during the nonbreeding season regardless of the method used. Detection of Leucocytozoon spp. infection from blood smears using microscopy was challenging.

Increase of respiratory illnesses among children in Beijing, China, during the autumn and winter of 2023

In 2023, through an ongoing respiratory pathogen surveillance system, we observed from mid-September onwards, an increase of respiratory illness among children aged ≤ 15 years presenting at hospital outpatient clinics in Beijing, China. Data indicated that illness was caused by multiple pathogens, predominantly Mycoplasma pneumoniae. Seasonality, periodicity and high prevalence of resistance to macrolide (30 of 30 strains sequenced with the A2063G mutation) were important characteristics of the M. pneumoniae epidemic, which resulted in a rise in consultations at specialised paediatric hospitals.

Application of Time-Series Analysis and Expert Judgment in Modeling and Forecasting Blood Donation Trends in Zimbabwe

Background. Blood cannot be artificially manufactured, and there is currently no substitute for human blood. The supply of blood in transfusion facilities requires constant and timely collection of blood from donors. Modeling and forecasting trends in blood collections are critical for determining both the current and future capacity requirements and appropriate models of adequate blood provision. Objectives. The objective of this study is to determine blood collection or donation patterns and develop time-series models that can be updated and refined in predicting future blood donations in Zimbabwe when given the historical data. Materials and Methods. Monthly blood donation data for the period 2009 to 2019 were collected retrospectively from the National Blood Service Zimbabwe database. Time-series models (i.e., the Seasonal Autoregressive Integrated Moving Average [SARIMA] and Error, Trend and Seasonal [ETS]) models were applied and compared. The models were chosen because of their ability to handle the seasonality and other time-series components evident in the blood donation data. Expert opinions and experience were used in selecting the models and in making inferences in the analysis. Results. Time-series plots of blood donations showed seasonal patterns, with significant drops in blood donations in months associated with Zimbabwe's school holidays (April, August, and December) and public holidays. During these holidays, there is a reduced number of school donors, while at about the same time, there is increasing blood demand as a result of road accidents. Model identification procedures established the SARIMA ( 1 , 1 , 2 ) ( 0 , 1 , 1 ) 12 model as the appropriate model for forecasting total blood donation in Zimbabwe. The results and forecasts show an upward trend in blood donations. According to the accuracy measures used, the SARIMA model outperforms the ETS model. Conclusions. Expert knowledge in the blood donation process, coupled with statistical models, can help explain trends exhibited in blood donation data in Zimbabwe. These findings help the blood authorities plan for blood donor campaign drives. The findings are key indicators of where to allocate more resources toward blood donation and when to collect more blood units. The increasing blood donation projections ensure a stable blood bank inventory in the near future.

Highlights

A SARIMA model can be used to predict the flow of blood donations in Zimbabwe.The seasonal blood donation pattern peaks in the months of March, June/July, and September.The donations troughs are in the months of April, August, December, and January. These are the months coinciding with school holidays in Zimbabwe.Both the SARIMA and ETS models provided similar forecasts, but measures of fit and expert knowledge gave a slight preference to the SARIMA ( 1 , 1 , 2 ) ( 0 , 1 , 1 ) 12 model in predicting the flow of blood donations in Zimbabwe.These model results are useful for guiding allocation of blood donation resources and blood donation drive timing.

Evening Chronotype and Suicide: Exploring Neuroinflammation and Psychopathological Dimensions as Possible Bridging Factors-A Narrative Review

A chronotype is generally defined as the variability of the phase angle of entrainment, while the latter reflects the relationship between the timing of a certain rhythm (e.g., the sleep-wake cycle) and the timing of an external temporal cue. Individuals can be placed on a spectrum from "morning types" (M types) to "evening types" (E types). E-chronotype has been proposed as a transdiagnostic risk factor for psychiatric conditions, and it has been associated with psychopathological dimensions. Eveningness seems to be correlated with both suicidal ideation (SI) and suicidal behavior (SB) through several possible mediating factors. Immunological alterations have also been linked to later chronotypes and SI/SB. This narrative review aims to summarize the evidence supporting the possible association between chronotypes and suicide and the eventual mediating role of neuroinflammation and several psychopathological dimensions. A search of the literature (2003-2023) was conducted using various databases: PUBMED, EMBASE, Scopus, UpToDate, PsycINFO, and Cochrane Library. English-language articles were collected and screened for eligibility. Despite the apparent absence of a direct correlation between E-chronotype and suicidality, E-chronotype promotes a chain of effects that could be involved in an increased risk of SB, in which with neuroinflammation possibly plays an intriguing role and some psychopathological dimensions may stand out.

Effect of age and season on respiratory mucosal immune marker profiles

BACKGROUND

The upper respiratory tract is continuously exposed to microorganisms and noxious elements, leading to local immune responses and the secretion of immune markers. While several studies describe immune marker profiles in respiratory mucosal samples in defined patient cohorts, mucosal immune profiles from the general population during the different seasons are lacking. Such baseline profiles are essential to understand the effect of various exposures to the mucosal immune system throughout life.

OBJECTIVE

We sought to establish baseline local upper respiratory mucosal immune profiles in the general population and assess these profiles with regard to age, sex, seasonality, and basic health and lifestyle factors.

METHODS

We measured the concentrations of 35 immune markers involved in a broad range of immunological processes at the mucosa in nasopharyngeal swab samples from 951 individuals, aged 0 to 86 years, from a nationwide study.

RESULTS

Clustering analysis showed that immune marker profiles clearly reflected immunological functions, such as tissue regeneration and antiviral responses. Immune marker concentrations changed strongly with seasonality and age, with the most profound changes occurring in the first 25 years of life; they were also associated with sex, body mass index, smoking, mild symptoms of airway infection, and chronic asthma and hay fever.

CONCLUSION

Immunological analyses of noninvasive mucosal samples provide insight into mucosal immune responses to microbial and noxious element exposure in the general population. These data provide a baseline for future studies on respiratory mucosal immune responses and for the development of mucosal immune-based diagnostics.

Emotional Bias among Individuals at Risk for Seasonal Affective Disorder-An EEG Study during Remission in Summer

Emotional bias in attention and memory is well researched in depression. Patients with depression prioritize processing of negative information over positive input. While there is evidence that emotional bias exists in seasonal affective disorder (SAD) during winter, it is unclear whether such altered cognition exists also during summer. Moreover, it is unclear whether such bias affects attention, memory, or both. In this study, we investigated 110 individuals in summer, 34 of whom reported suffering from low mood during winter, according to the seasonal pattern assessment questionnaire. While the electroencephalogram was recorded, participants learned 60 emotional pictures and subsequently were asked to recognize them in an old/new task. There were no clear group differences in behavioral measures, and no brain response differences in frontal alpha power during learning. During recognition, at 100-300 ms post stimulus individuals with higher seasonality scores exhibited larger alpha power in response to negative as compared to neutral stimuli, while individuals with low seasonality scores exhibited larger alpha power in response to positive as compared to neutral stimuli. While we cannot draw conclusions whether this is an effect of attention or memory, the finding suggests that early cognitive processes are altered already during summer in individuals with increased likelihood to experience SAD during winter. Our data provide evidence for an all-year-round cognitive vulnerability in this population.

Risk for Seasonal Affective Disorder (SAD) Linked to Circadian Clock Gene Variants

Molecular pathways affecting mood are associated with circadian clock gene variants and are influenced, in part, by the circadian clock, but the molecular mechanisms underlying this link are poorly understood. We use machine learning and statistical analyses to determine the circadian gene variants and clinical features most highly associated with symptoms of seasonality and seasonal affective disorder (SAD) in a deeply phenotyped population sample. We report sex-specific clock gene effects on seasonality and SAD symptoms; genotypic combinations of CLOCK3111/ZBTB20 and PER2/PER3B were significant genetic risk factors for males, and CRY2/PER3C and CRY2/PER3-VNTR were significant risk factors for females. Anxiety, eveningness, and increasing age were significant clinical risk factors for seasonality and SAD for females. Protective factors for SAD symptoms (in females only) included single gene variants: CRY1-GG and PER3-VNTR-4,5. Clock gene effects were partially or fully mediated by diurnal preference or chronotype, suggesting multiple indirect effects of clock genes on seasonality symptoms. Interestingly, protective effects of CRY1-GG, PER3-VNTR-4,5, and ZBTB20 genotypes on seasonality and depression were not mediated by chronotype, suggesting some clock variants have direct effects on depressive symptoms related to SAD. Our results support previous links between CRY2, PER2, and ZBTB20 genes and identify novel links for CLOCK and PER3 with symptoms of seasonality and SAD. Our findings reinforce the sex-specific nature of circadian clock influences on seasonality and SAD and underscore the multiple pathways by which clock variants affect downstream mood pathways via direct and indirect mechanisms.

Seasonality of syphilis in males through the 2011 to 2019 mandatory surveillance period: A cross-sectional study in South Korea

Although the effects of seasonality on syphilis have been discussed previously, no previous study has evaluated the seasonality of syphilis incidence by sex and age group. We examined the seasonality of syphilis incidence by sex and age group in Korea from 2011 to 2019. The incidence of syphilis was calculated on the basis of Korea Diseases Control and Prevention Agency data, and an autoregressive integrated moving average (ARIMA) model and seasonal and trend decomposition using Loess were used to analyze the seasonality of the incidence in relation to epidemiological factors. The annual age-standardized incidence rates of primary, secondary, and congenital syphilis were 21.1, 8.8, and 64.0 cases/million persons, respectively, from 2011 to 2019. The highest incidence rates for primary and secondary syphilis were observed among those aged 20 to 29, 13 to 19, and 30 to 49 years, but not among the lower age groups. In analyses based on the ARIMA model, all univariate time series showed the highest goodness-of-fit results with ARIMA for primary syphilis (1,1,2), secondary syphilis (1,1,1), and congenital syphilis (0,1,2) (2,0,0) models. This study suggests that the incidence of secondary syphilis shows a summer seasonality for males and the highest incidence rate in the 20 to 29-year age group for both males and females in Korea. Public health action is needed to prevent an increase in syphilis incidence associated with sex, age group, and seasonal patterns.

Tensorial Principal Component Analysis in Detecting Temporal Trajectories of Purchase Patterns in Loyalty Card Data: Retrospective Cohort Study

BACKGROUND

Loyalty card data automatically collected by retailers provide an excellent source for evaluating health-related purchase behavior of customers. The data comprise information on every grocery purchase, including expenditures on product groups and the time of purchase for each customer. Such data where customers have an expenditure value for every product group for each time can be formulated as 3D tensorial data.

OBJECTIVE

This study aimed to use the modern tensorial principal component analysis (PCA) method to uncover the characteristics of health-related purchase patterns from loyalty card data. Another aim was to identify card holders with distinct purchase patterns. We also considered the interpretation, advantages, and challenges of tensorial PCA compared with standard PCA.

METHODS

Loyalty card program members from the largest retailer in Finland were invited to participate in this study. Our LoCard data consist of the purchases of 7251 card holders who consented to the use of their data from the year 2016. The purchases were reclassified into 55 product groups and aggregated across 52 weeks. The data were then analyzed using tensorial PCA, allowing us to effectively reduce the time and product group-wise dimensions simultaneously. The augmentation method was used for selecting the suitable number of principal components for the analysis.

RESULTS

Using tensorial PCA, we were able to systematically search for typical food purchasing patterns across time and product groups as well as detect different purchasing behaviors across groups of card holders. For example, we identified customers who purchased large amounts of meat products and separated them further into groups based on time profiles, that is, customers whose purchases of meat remained stable, increased, or decreased throughout the year or varied between seasons of the year.

CONCLUSIONS

Using tensorial PCA, we can effectively examine customers' purchasing behavior in more detail than with traditional methods because it can handle time and product group dimensions simultaneously. When interpreting the results, both time and product dimensions must be considered. In further analyses, these time and product groups can be directly associated with additional consumer characteristics such as socioeconomic and demographic predictors of dietary patterns. In addition, they can be linked to external factors that impact grocery purchases such as inflation and unexpected pandemics. This enables us to identify what types of people have specific purchasing patterns, which can help in the development of ways in which consumers can be steered toward making healthier food choices.