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1.
Rev. biol. trop ; 72(1): e52855, ene.-dic. 2024. tab, graf
Artigo em Espanhol | LILACS, SaludCR | ID: biblio-1559313

RESUMO

Resumen Introducción: El uso de artrópodos en estudios ecológicos en el bosque seco tropical (Bs-T) de Colombia se centra mayormente en arañas, mariposas, hormigas y escarabajos coprófagos; por lo tanto, es necesario comprender como es la dinámica estacional de otros grupos como Geadephaga en este ecosistema. Objetivo: Evaluar la variación espacio-temporal y el efecto de las condiciones ambientales sobre la diversidad de las comunidades de Geadephaga en dos fragmentos de Bs-T en el Caribe colombiano. Métodos: El estudio se llevó a cabo en cuatro eventos de muestreo entre febrero y junio de 2018; cada uno con una duración de cuatro días y cuatro noches. En cada localidad (Reserva Campesina La Montaña = RCM y Reserva La Flecha = RLF), se marcaron cuatro estaciones distanciadas 350 m, con parcelas de 50×50 m. En el centro de cada parcela se instaló una trampa de luz, mientras que en los cuatro vértices se instalaron trampas de caída, y se realizó captura manual, cernido de hojarasca y perturbación de follaje. Resultados: Se capturó un total de 348 ejemplares de Carabidae y 114 de Cicindelidae. La riqueza y la abundancia presentaron los valores más bajos durante el período seco, mientras que los mayores valores se observaron durante el período de lluvias, en ambos fragmentos. Tetracha affinis (Dejean, 1825) fue la especie más abundante en la RCM durante el período lluvioso. Conclusiones: La variación de la riqueza y abundancia de Geadephaga responde a un patrón estacional en ambos fragmentos. Se encontró una amplia disimilitud entre las comunidades de Geadephaga de ambos fragmentos, pese a tener condiciones ambientales parecidas.


Abstract Introduction: The use of arthropods in ecological studies in the tropical dry forest (TDF) of Colombia focused mainly on spiders, butterflies, ants, and dung beetles; therefore, it is necessary to understand the seasonal dynamics of the other groups such as Geadephaga in this ecosystem. Objective: To evaluate the spatio-temporal variations and the effect of environmental conditions on the diversity of the Geadephaga communities in two TDF fragments in the Colombian Caribbean. Methods: This study was conducted during four sampling events between February and June 2018, each lasting four days, and four nights. Four sampling stations were selected in each locality (Reserva Campesina La Montaña = RCM and Reserva La Flecha = RLF), separated 350 m one from another, with square plots of 50 × 50 m. A light trap was installed in the center of each square, while pitfall traps were installed in the four vertices, and manual capture, beating sheets and leaf litter sieve were carried out. Results: A total of 348 Carabidae and 114 of Cicindelidae were captured. In both fragments, the richness and abundance presented the lowest values in dry season, while the highest values were observed during the rainy season. Tetracha affinis (Dejean, 1825) was the most abundant species in RCM during rainy season. Conclusions: The richness variation and abundance of Geadephaga corresponds to a seasonal pattern at both locations. A high dissimilarity between the communities of Geadephaga from the two fragments was found, despite having similar environmental conditions.


Assuntos
Animais , Besouros/classificação , Estudos de Amostragem , Colômbia , Biodiversidade
2.
Sci Rep ; 14(1): 19436, 2024 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-39169107

RESUMO

As reproduction phenologies shift with climate change, populations can experience intraspecific priority effects, wherein early hatching cohorts experience an advantage over late-hatching cohorts, resulting in altered demography. Our study objective was to identify how variation in egg hatching phenology alters intraspecific interactions in small-mouthed salamanders, Ambystoma texanum. We addressed two research questions: (Q1) How are demographic responses altered by variation in the temporal duration of hatching between cohorts, and (Q2) How does the seasonality of hatching delays affect demographic responses? We manipulated hatching phenologies of A. texanum eggs and reared larvae in outdoor mesocosms to metamorphosis. For Q1, hatching delay exhibited non-linear relationships with survival and body size, with the greatest asynchrony in cohort additions resulting in the highest mortality and largest body sizes. For Q2, hatching delay effects were stronger (i.e., survival was lower and body sizes larger) when they occurred later in the season, potentially due to temperature differences that larvae experienced. Overall, our results demonstrate that changes in intraspecific interactions due to phenological shifts can be context-dependent, depending on the strength (i.e., temporal duration) and seasonality of such processes. Identifying context-dependencies of phenological shifts will be critical for predicting changes in organismal demographics with climatic shifts.


Assuntos
Larva , Metamorfose Biológica , Reprodução , Animais , Larva/fisiologia , Larva/crescimento & desenvolvimento , Reprodução/fisiologia , Metamorfose Biológica/fisiologia , Lagoas , Mudança Climática , Estações do Ano , Tamanho Corporal , Ambystoma/fisiologia , Óvulo/fisiologia , Temperatura , Cruzamento
3.
J Infect Public Health ; 17(9): 102521, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39173555

RESUMO

BACKGROUND: Influenza represents a significant global health burden for individuals and society. This study assessed the burden of medically attended influenza at a tertiary medical center in Lebanon to describe the demographics, risk factors, and outcomes prior to the COVID-19 pandemic. METHODS: This was a retrospective review of patients who tested positive for the influenza virus during three seasons between July 1, 2016 to June 30, 2019, at the American University of Beirut Medical Center. RESULTS: A total of 2049 patients who tested positive for influenza were analyzed. Influenza A accounted for 79.6 % of cases, and influenza B for 19.7 %, with influenza activity starting in October/November and peaking in December/January. Older age above 65 years (AOR=3.584), obesity (AOR=2.183), and chronic conditions such as chronic lung diseases (AOR=1.832), and bacterial co-infection (AOR= 2.834) were found to be independent risk factors for developing complications. Viral co-infection increased the likelihood of death tenfold. Vaccinated patients had a shorter mean hospital stay duration and a lower intensive care unit admission rate. CONCLUSION: The burden of medically attended influenza at our tertiary medical center in Lebanon prior to the COVID-19 pandemic was high. Vaccination decreased the likelihood of complications leading to intensive care unit admission in patients at risk.

4.
J Affect Disord ; 364: 96-103, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39142572

RESUMO

BACKGROUND: Growing evidence suggests the relevance of affective temperaments in the development of mood disorders. This study aims to assess their potential role as a vulnerability factor for seasonal affective disorder (SAD) and subsyndromal SAD (S-SAD) in a sample of young individuals without a history of clinical diagnosis. METHODS: Eight hundred and forty-six university students were enrolled in a cross-sectional study. Participants were evaluated for exclusion and inclusion criteria and divided into Control, S-SAD, and SAD groups. They filled out two self-administered questionnaires to assess the degree of seasonality problems and the predominant type of affective temperaments, the Seasonal Pattern Assessment Questionnaire (SPAQ), and the Temperament Evaluation Instrument of Memphis, Pisa, Paris, and San Diego-Auto-questionnaire version scale (briefTEMPS-M version). We conducted a multinomial logistic regression model to explore the relationship between affective temperaments and seasonality. RESULTS: Our results evidenced that cyclothymic [χ2 (2) = 33.486, p < 0.001] and anxious [χ2 (2) = 86.991, p < 0.001] temperaments were significant predictors in the model, suggesting that individuals with cyclothymic and anxious temperaments are at increased risk of developing SAD, due to heightened seasonal changes in mood and behavior. In contrast, people with hyperthymic temperament appear less susceptible to experiencing seasonal problems. LIMITATIONS: The homogeneity of the sample; only retrospective self-reported data were considered; measures of temperament and seasonality were simultaneously assessed. CONCLUSIONS: Understanding which affective temperaments may constitute a potential predisposing factor for vulnerability to seasonal changes can aid in better assessing SAD and predicting its outcome.

5.
Curr Zool ; 70(4): 453-464, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39176064

RESUMO

Knowledge regarding the influence of individual traits on interaction patterns in nature can help understand the topological role of individuals within a network of intrapopulation interactions. We tested hypotheses on the relationships between individuals' positions within networks (specialization and centrality) of 4 populations of the mouse opossum Gracilinanus agilis and their traits (i.e., body length, body condition, tail length relative to body length, sex, reproductive condition, and botfly parasitism) and also seasonal effects in the Brazilian savanna. Individuals with lower body length, better body condition, and relatively shorter tail were more specialized (i.e., less connected within the network). Individuals were also more specialized and less connected during the warm-wet season. The relationship between individuals' position in the network and body traits, however, was independent of season. We propose that specialization may arise not only as a result of preferred feeding strategies by more capable individuals (i.e., those with better body condition and potentially prone to defend and access high-quality food resources) but also because of morphological constraints. Smaller/younger individuals (consequently with less experience in foraging) and short-tailed individuals (less skilled to explore the vertical strata of the vegetation) would feed only on a subset of the available food resources and consequently become more specialized. Moreover, individuals are more specialized during the warm-wet season because of high competition (population-dense period) and higher ecological opportunities (resource-rich period). Therefore, our study reveals the relevance of individual traits in shaping interaction patterns and specialization in populations.

6.
Stud Health Technol Inform ; 316: 1632-1636, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39176523

RESUMO

Seasonality patterns are reported for various psychiatric disorders. Concerning adolescents, there is an increased frequency of general emergency department visits for mental health disorders observed between March and May, as well as in October and November. We conducted a retrospective cohort study using the French health insurance medico-administrative database. We extracted psychotropic drug deliveries occurring between 2015 and 2019 for patients aged between 12 and 18 years old. Each drug delivery was classified as occurring during a school period (Sc), the summer holidays (SumH) or other shorter holidays periods (ShH). We compared the number of distinct patients, as well as the proportion of new consumers, according to week status. Anxiolytics and hypnotics were more frequently dispensed during the school periods and short breaks than during the summer holidays. Conversely, antidepressants were more commonly dispensed during the short breaks rather than school periods and summer holidays. The stressful effects induced by schooling appear to be addressed in the first line by anxiolytics and hypnotics, while antidepressants are more frequently introduced during school holidays.


Assuntos
Psicotrópicos , Humanos , Adolescente , Estudos Retrospectivos , Psicotrópicos/uso terapêutico , França , Criança , Feminino , Masculino , Instituições Acadêmicas , Estações do Ano
8.
Ann Bot ; 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39166296

RESUMO

BACKGROUND AND AIMS: Changing precipitation regimes can influence terrestrial plants and ecosystems. However, plant phenological responses to changing precipitation temporal patterns and the underlying mechanisms are largely unclear. This study was conducted to explore the effects of seasonal precipitation redistribution on plant reproductive phenology in a temperate steppe. METHODS: A field experiment with control (C), advanced (AP) and delayed (DP) growing-season precipitation peaks, and the combination of AP and DP (ADP) were employed. Seven dominant plant species were selected and divided into two functional groups (early- vs. middle-flowering species, shallow- vs. deep-rooted species) to monitor reproductive phenology including budding, flowering, and fruiting date, as well as reproductive duration for four growing seasons from 2015 to 2017, and 2022. KEY RESULTS: The AP, but not DP treatment advanced the phenological (i.e., budding, flowering, and fruiting) dates and lengthened the reproductive duration across the 4 growing seasons and 7 monitored species. In addition, the phenological responses showed divergent patterns among different plant functional groups, which could be attributed to shifts in soil moisture and its variability in different months and soil depths. Moreover, species with lengthened reproductive duration increased phenological overlap with other species, which could have a negative impact on their dominance under the AP treatment. CONCLUSIONS: Our findings reveal that changing precipitation seasonality could have considerable impacts on plant phenology by affecting soil water availability and variability. Incorporating these two factors simultaneously in the phenology models will help us understand the response of plant phenology under intensified changing precipitation scenarios. In addition, the observations of decreased dominance for the species with lengthened reproductive duration suggest that changing reproductive phenology can have a potential to affect community composition in grasslands under global change.

9.
Sci Rep ; 14(1): 18274, 2024 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-39107404

RESUMO

Nursing honeybees produce brood food with millimolar concentrations of acetylcholine (ACh), which is synthesized through head gland secretions mixed with honey stomach contents. While we previously demonstrated the necessity of ACh for proper larval development, the dynamics of ACh levels throughout ontogenesis and their seasonal variations have remained unclear until now. Our HPLC analysis reveals dependencies of choline and ACh levels on larval development days (LDDs), influenced by seasonal (April-September) variations. Median ACh concentrations peak on LDD 2, declining significantly toward cell capping, while choline levels are lowest during the initial LDDs, rising markedly toward cell capping. Seasonal patterns show peak ACh levels from April to June and a low in August, paralleling choline's peak in July and low in August. This seasonality holds consistently across multiple years (2020-2022) and colonies, despite potential variations in colony performance and environmental conditions. Our analysis found no correlation between temperature, sunshine, precipitation, or favourable foraging days and ACh/choline levels, suggesting the involvement of additional factors. These findings underscore the seasonal fluctuation of ACh levels and its potential implications for the genetic programs governing winter bee development.


Assuntos
Acetilcolina , Colina , Estações do Ano , Animais , Abelhas/metabolismo , Abelhas/fisiologia , Colina/metabolismo , Colina/análise , Acetilcolina/metabolismo , Acetilcolina/análise , Larva/metabolismo , Mel/análise , Fatores Etários
10.
Mult Scler Relat Disord ; 90: 105814, 2024 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-39151237

RESUMO

BACKGROUND: Seasonal variation in attacks of acute disseminated encephalomyelitis (ADEM1) is reported in some studies. Myelin oligodendrocyte glycoprotein (MOG) antibodies are found in up to 50 % of ADEM cases. Despite this, there has been no adequately powered study of seasonality in MOG antibody-associated disease (MOGAD). We sought to determine whether there was an effect of season on incidence of total attacks and onset attacks of MOGAD. METHODS: We searched the large national Oxford-based NMO Service database to identify attacks of MOGAD occurring between 2010 and 2021. Month of each attack was extracted and Edwards' test of seasonal variation was applied to determine whether there was a seasonal effect on total attacks and onset attacks. RESULTS: Neither incidence of total attacks nor incidence of onset attacks varied significantly by month. CONCLUSION: There is no evidence of seasonal fluctuations in the incidence of MOGAD attacks in the UK.

11.
Domest Anim Endocrinol ; 89: 106878, 2024 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-39151257

RESUMO

Hormonal protocols based on progestogens and equine chorionic gonadotrophin (eCG) are efficient for estrus and ovulation synchronization in ewes. Although eCG is indispensable during seasonal anestrus, it may not be necessary during the breeding season. Thus, we tested the hypothesis that GnRH is effective in replacing eCG during the breeding season allowing satisfactory ovulation rate, luteal function and conception rates after timed artificial insemination (TAI). Ewes (n = 134) with a minimum body condition score of 2.5 (0-5 scale) were treated with intravaginal devices (IVD) containing 60 mg of medroxyprogesterone acetate (MPA) for seven days and received 0.26 mg of sodium cloprostenol at the time of IVD removal. In Exp. 1, at IVD removal, ewes (n = 29) were allocated to three groups: eCG (200 IU at IVD removal; n = 10); eCG+GnRH (200 IU eCG at IVD removal and 4 µg of buserelin 36 h later; n = 10); or GnRH (buserelin 36 h after IVD removal; n = 9). Blood samples were collected 2, 6 and 12 days after TAI moment (54 h after IVD removal), for progesterone (P4) analysis. In Exp 2, the ewes were allocated to eCG (n = 10) or GnRH (n = 10) groups, as above described, and ovulation moment was evaluated 54, 66 and 78 h after IVD removal. In Exp 3, TAI was performed in ewes from eCG (n = 45) and GnRH (n = 40) groups using 100 × 106 motile spermatozoa from a pool of semen collected from four rams. In Exp. 1, based on P4 levels, we confirmed that all the ewes ovulated (29/29) and there was no significant effect of group (P = 0.89) or group x day (P = 0.18) on P4 concentration, being observed a significant effect of day (P = 0.0001). In Exp. 2, the maximum DF diameter (P = 0.26) and ovulation moment (P = 0.69) did not differ between groups. In Exp. 3, pregnancy rate was significantly lower (P = 0.02) in GnRH (22.5 %; 9/40) compared to eCG (46.7 %; 21/45). The results indicate that, although ovulation and luteal function were not altered after eCG, eCG+GnRH or GnRH treatment, GnRH alone before TAI cannot be used to replace eCG treatment during the breeding season.

12.
Sci Total Environ ; : 175463, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39153608

RESUMO

Hydrometeorological processes are often assumed to be key drivers of plastic transport. However, the predominant focus on these factors overlooks the impact of anthropogenic factors, such as mismanaged plastic waste (MPW) on plastic transport variability. Here, we investigate the roles of both anthropogenic and hydrometeorological factors on plastic pollution in the Odaw catchment, Ghana. Data on macroplastic transport and density were collected at ten locations between December 2021 and December 2022. We tested for differences between the wet and dry seasons and applied a multiple regression analysis to examine the separate and combined impact of hydrometeorological variables (rainfall, discharge, and windspeed) on macroplastic transport. Additionally, we analyzed the spatial correlation in macroplastic transport/density with MPW and population density. Data collection involved visual counting of floating macroplastics at 10 river locations and counting litter at 9 riverbanks and land locations. Rainfall data was sourced from TAHMO (Trans-African Hydrometeorological Observatory), discharge was measured during field campaigns, and windspeed data sourced from a global climate data provider. We used globally modelled MPW estimates to represent anthropogenic factors. Contrary to previous studies, we found no seasonal differences in macroplastic pollution and only weak correlations were observed between the hydrometeorological variables and macroplastic transport. However, a strong correlation was observed between MPW and macroplastic pollution. We hypothesize that, the influence of hydrometeorological factors on macroplastic transport depend on the relative impact of anthropogenic factors. Our research highlights the limited role of hydrometeorology, showing the significant role of mismanaged plastic waste to field monitored macroplastic pollution variability in the catchment. This insight is essential for future research as it highlights the importance of holistically investigating both anthropogenic and hydrometeorological factors in explaining plastic transport and retention dynamics. This insight is essential for developing interventions that effectively address plastic pollution in catchments.

13.
Proc Natl Acad Sci U S A ; 121(33): e2313428121, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39102551

RESUMO

Moral values guide consequential attitudes and actions. Here, we report evidence of seasonal variation in Americans' endorsement of some-but not all-moral values. Studies 1 and 2 examined a decade of data from the United States (total N = 232,975) and produced consistent evidence of a biannual seasonal cycle in values pertaining to loyalty, authority, and purity ("binding" moral values)-with strongest endorsement in spring and autumn and weakest endorsement in summer and winter-but not in values pertaining to care and fairness ("individualizing" moral values). Study 2 also provided some evidence that the summer decrease, but not the winter decrease, in binding moral value endorsement was stronger in regions with greater seasonal extremity. Analyses on an additional year of US data (study 3; n = 24,199) provided further replication and showed that this biannual seasonal cycle cannot be easily dismissed as a sampling artifact. Study 4 provided a partial explanation for the biannual seasonal cycle in Americans' endorsement of binding moral values by showing that it was predicted by an analogous seasonal cycle in Americans' experience of anxiety. Study 5 tested the generalizability of the primary findings and found similar seasonal cycles in endorsement of binding moral values in Canada and Australia (but not in the United Kingdom). Collectively, results from these five studies provide evidence that moral values change with the seasons, with intriguing implications for additional outcomes that can be affected by those values (e.g., intergroup prejudices, political attitudes, legal judgments).


Assuntos
Princípios Morais , Estações do Ano , Humanos , Estados Unidos , Valores Sociais , Feminino , Masculino
14.
Proc Biol Sci ; 291(2028): 20241013, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39106952

RESUMO

Males and females often differ in ecology, behaviour and lifestyle, and these differences are expected to lead to sex differences in parasite susceptibility. However, neither the sex differences in parasite prevalence, nor their ecological and evolutionary drivers have been investigated across a broad range of taxa using phylogenetically corrected analyses. Using the most extensive dataset yet that includes 755 prevalence estimates from 151 wild bird species in a meta-analytic framework, here we compare sex differences in blood and gastrointestinal parasites. We show that despite sex differences in parasite infection being frequently reported in the literature, only Haemoproteus infections were more prevalent in females than in males. Notably, only seasonality was strongly associated with the sex-specific parasite prevalence of both Leucocytozoon and Haemoproteus, where birds showed greater female bias in prevalence during breeding periods compared to the non-breeding period. No other ecological or sexual selection variables were associated with sex-specific prevalence of parasite prevalence. We suggest that much of the variation in sex-biased prevalence could be idiosyncratic, and driven by local ecology and behavioural differences of the parasite and the host. Therefore, breeding ecology and sexual selection may only have a modest influence on sex-different parasite prevalence across wild birds.


Assuntos
Evolução Biológica , Doenças das Aves , Aves , Animais , Aves/parasitologia , Feminino , Doenças das Aves/parasitologia , Doenças das Aves/epidemiologia , Masculino , Prevalência , Haemosporida/fisiologia , Fatores Sexuais , Caracteres Sexuais , Animais Selvagens/parasitologia , Estações do Ano , Infecções Protozoárias em Animais/epidemiologia , Infecções Protozoárias em Animais/parasitologia
15.
Open Forum Infect Dis ; 11(8): ofae418, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39113828

RESUMO

Background: We characterized the global epidemiology and seasonality of human coronaviruses (HCoVs) OC43, NL63, 229E, and HKU1. Methods: In this systematic review, we searched MEDLINE, EMBASE, Web of Science, SCOPUS, CINAHL, and backward citations for studies published until 1 September 2023. We included studies with ≥12 months of consecutive data and tested for ≥1 HCoV species. Case reports, review articles, animal studies, studies focusing on SARS-CoV-1, SARS-CoV-2, and/or Middle East respiratory syndrome, and those including <100 cases were excluded. Study quality and risk of bias were assessed using Joanna Briggs Institute Critical Appraisal Checklist tools. We reported the prevalence of all HCoVs and individual species. Seasonality was reported for studies that included ≥100 HCoVs annually. This study is registered with PROSPERO, CRD42022330902. Results: A total of 201 studies (1 819 320 samples) from 68 countries were included. A high proportion were from China (19.4%; n = 39), whereas the Southern Hemisphere was underrepresented. Most were case series (77.1%, n = 155) with samples from secondary care (74.1%, n = 149). Seventeen (8.5%) studies included asymptomatic controls, whereas 76 (37.8%) reported results for all 4 HCoV species. Overall, OC43 was the most prevalent HCoV. Median test positivity of OC43 and NL63 was higher in children, and 229E and HKU1 in adults. Among 18 studies that described seasonality (17 from the Northern Hemisphere), circulation of all HCoVs mostly peaked during cold months. Conclusions: In our comprehensive review, few studies reported the prevalence of individual HCoVs or seasonality. Further research on the burden and circulation of HCoVs is needed, particularly from Africa, South Asia, and Central/South America.

16.
J Pineal Res ; 76(5): e12996, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39129720

RESUMO

In mammals, seasonal opportunities and challenges are anticipated through programmed changes in physiology and behavior. Appropriate anticipatory timing depends on synchronization to the external solar year, achieved through the use of day length (photoperiod) as a synchronizing signal. In mammals, nocturnal production of melatonin by the pineal gland is the key hormonal mediator of photoperiodic change, exerting its effects via the hypothalamopituitary axis. In this review/perspective, we consider the key developments during the history of research into the seasonal synchronizer effect of melatonin, highlighting the role that the pars tuberalis-tanycyte module plays in this process. We go on to consider downstream pathways, which include discrete hypothalamic neuronal populations. Neurons that express the neuropeptides kisspeptin and (Arg)(Phe)-related peptide-3 (RFRP-3) govern seasonal reproductive function while neurons that express somatostatin may be involved in seasonal metabolic adaptations. Finally, we identify several outstanding questions, which need to be addressed to provide a much thorough understanding of the deep impact of melatonin upon seasonal synchronization.


Assuntos
Mamíferos , Melatonina , Estações do Ano , Melatonina/metabolismo , Animais , Mamíferos/metabolismo , Fotoperíodo , Humanos , Glândula Pineal/metabolismo
17.
Glob Chang Biol ; 30(8): e17454, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39132898

RESUMO

Tropical and subtropical evergreen broadleaved forests (TEFs) contribute more than one-third of terrestrial gross primary productivity (GPP). However, the continental-scale leaf phenology-photosynthesis nexus over TEFs is still poorly understood to date. This knowledge gap hinders most light use efficiency (LUE) models from accurately simulating the GPP seasonality in TEFs. Leaf age is the crucial plant trait to link the dynamics of leaf phenology with GPP seasonality. Thus, here we incorporated the seasonal leaf area index of different leaf age cohorts into a widely used LUE model (i.e., EC-LUE) and proposed a novel leaf age-dependent LUE model (denoted as LA-LUE model). At the site level, the LA-LUE model (average R2 = .59, average root-mean-square error [RMSE] = 1.23 gC m-2 day-1) performs better than the EC-LUE model in simulating the GPP seasonality across the nine TEFs sites (average R2 = .18; average RMSE = 1.87 gC m-2 day-1). At the continental scale, the monthly GPP estimates from the LA-LUE model are consistent with FLUXCOM GPP data (R2 = .80; average RMSE = 1.74 gC m-2 day-1), and satellite-based GPP data retrieved from the global Orbiting Carbon Observatory-2 (OCO-2) based solar-induced chlorophyll fluorescence (SIF) product (GOSIF) (R2 = .64; average RMSE = 1.90 gC m-2 day-1) and the reconstructed TROPOspheric Monitoring Instrument SIF dataset using machine learning algorithms (RTSIF) (R2 = .78; average RMSE = 1.88 gC m-2 day-1). Typically, the estimated monthly GPP not only successfully represents the unimodal GPP seasonality near the Tropics of Cancer and Capricorn, but also captures well the bimodal GPP seasonality near the Equator. Overall, this study for the first time integrates the leaf age information into the satellite-based LUE model and provides a feasible implementation for mapping the continental-scale GPP seasonality over the entire TEFs.


Assuntos
Florestas , Folhas de Planta , Tecnologia de Sensoriamento Remoto , Estações do Ano , Folhas de Planta/crescimento & desenvolvimento , Fotossíntese , Modelos Teóricos , Luz , Árvores/crescimento & desenvolvimento , Modelos Biológicos , Clima Tropical
18.
Water Res ; 263: 122140, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39096811

RESUMO

The most widely used herbicide glyphosate contaminates surface waters around the globe. Both agriculture and urban applications are discussed as sources for glyphosate. To better delineate these sources, we investigated long-term time series of concentrations of glyphosate and its main transformation product aminomethylphosphonic acid (AMPA) in a large meta-analysis of about 100 sites in the USA and Europe. The U.S. data reveal pulses of glyphosate and AMPA when the discharge of the river is high, likely indicating mobilization by rain after herbicide application. In contrast, European concentration patterns of glyphosate and AMPA show a typical cyclic-seasonal component in their concentration patterns, correlating with patterns of wastewater markers such as pharmaceuticals, which is consistent with the frequent detection of these compounds in wastewater treatment plants. Our large meta-analysis clearly shows that for more than a decade, municipal wastewater was a very important source of glyphosate. In addition, European river water data show rather high and constant base mass fluxes of glyphosate all over the year, not expected from herbicide application. From our meta-analysis, we define criteria for a source of glyphosate, which was hidden so far. AMPA is known to be a transformation product not only of glyphosate but also of aminopolyphosphonates used as antiscalants in many applications. As they are used in laundry detergents in Europe but not in the USA, we hypothesize that glyphosate may also be a transformation product of aminopolyphosphonates.

19.
Mol Ecol ; : e17447, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38946196

RESUMO

Organisms adapt to daily and seasonal environmental changes to maximise their metabolic and reproductive fitness. For seasonally breeding animals, photoperiod is considered the most robust cue to drive these changes. It, however, does not explain the interannual variations in different seasonal phenotypes. Several studies have repeatedly shown the influence of ambient temperature on the timing of different seasonal physiologies including the timing of migration, reproduction and its associated behaviours, etc. In the present review, we have discussed the effects of changes in ambient temperature on different seasonal events in endotherms with a focus on migratory birds as they have evolved to draw benefits from distinct but largely predictable seasonal patterns of natural resources. We have further discussed the physiological and molecular mechanisms by which temperature affects seasonal timings. The primary brain area involved in detecting temperature changes is the hypothalamic preoptic area. This area receives thermal inputs via sensory neurons in the peripheral ganglia that measure changes in thermoregulatory tissues such as the skin and spinal cord. For the input signals, several thermal sensory TRP (transient receptor potential ion channels) channels have been identified across different classes of vertebrates. These channels are activated at specific thermal ranges. Once perceived, this information should activate an effector function. However, the link between temperature sensation and the effector pathways is not properly understood yet. Here, we have summarised the available information that may help us understand how temperature information is translated into seasonal timing.

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