Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.704
Filtrar
Más filtros

Intervalo de año de publicación
1.
Cell ; 167(4): 1111-1124.e13, 2016 11 03.
Artículo en Inglés | MEDLINE | ID: mdl-27814508

RESUMEN

Differences in susceptibility to immune-mediated diseases are determined by variability in immune responses. In three studies within the Human Functional Genomics Project, we assessed the effect of environmental and non-genetic host factors of the genetic make-up of the host and of the intestinal microbiome on the cytokine responses in humans. We analyzed the association of these factors with circulating mediators and with six cytokines after stimulation with 19 bacterial, fungal, viral, and non-microbial metabolic stimuli in 534 healthy subjects. In this first study, we show a strong impact of non-genetic host factors (e.g., age and gender) on cytokine production and circulating mediators. Additionally, annual seasonality is found to be an important environmental factor influencing cytokine production. Alpha-1-antitrypsin concentrations partially mediate the seasonality of cytokine responses, whereas the effect of vitamin D levels is limited. The complete dataset has been made publicly available as a comprehensive resource for future studies. PAPERCLIP.


Asunto(s)
Citocinas/genética , Citocinas/inmunología , Interacción Gen-Ambiente , Adolescente , Adulto , Anciano , Envejecimiento , Animales , Artritis/inmunología , Sangre/inmunología , Índice de Masa Corporal , Femenino , Proyecto Genoma Humano , Humanos , Infecciones/inmunología , Infecciones/microbiología , Infecciones/virología , Inflamación/inmunología , Inflamación/microbiología , Leucocitos Mononucleares/inmunología , Macrófagos/inmunología , Masculino , Ratones , Persona de Mediana Edad , Estaciones del Año , Caracteres Sexuales
2.
Am Nat ; 203(5): 562-575, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38635362

RESUMEN

AbstractIn species with resource-defense mating systems (such as most temperate-breeding songbirds), male dispersal is often considered to be limited in both frequency and spatial extent. When dispersal occurs within a breeding season, the favored explanation is ecological resource tracking. In contrast, movements of male birds associated with temporary emigration, such as polyterritoriality (i.e., defense of an additional location after attracting a female in the initial territory), are usually attributed to mate searching. We suggest that male dispersal and polyterritoriality are functionally related and that mate searching may be a unifying hypothesis for predicting the within-season movements of male songbirds. Here, we test three key predictions derived from this hypothesis in Wood Warblers (Phylloscopus sibilatrix). We collected data on the spatial behavior of 107 males between 2017 and 2019 and related male movements to a new territory (in both a dispersal and a polyterritorial context) to mating potential in the current territory. Most males dispersed from their territories within days or weeks after failing to attract a female, despite occupying territories in apparently suitable habitat. Probability of polyterritoriality by paired males increased after the peak fertile period of their mate. Males never dispersed following nest predation if the female remained to renest. Thus, our data are consistent with the hypothesis that both movement types are functionally related to mate searching.


Asunto(s)
Pájaros Cantores , Animales , Femenino , Masculino , Conducta Sexual Animal , Estaciones del Año , Ecosistema , Reproducción
3.
Planta ; 259(4): 72, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38386103

RESUMEN

MAIN CONCLUSION: Molecular mechanisms of biological rhythms provide opportunities to harness functional allelic diversity in core (and trait- or stress-responsive) oscillator networks to develop more climate-resilient and productive germplasm. The circadian clock senses light and temperature in day-night cycles to drive biological rhythms. The clock integrates endogenous signals and exogenous stimuli to coordinate diverse physiological processes. Advances in high-throughput non-invasive assays, use of forward- and inverse-genetic approaches, and powerful algorithms are allowing quantitation of variation and detection of genes associated with circadian dynamics. Circadian rhythms and phytohormone pathways in response to endogenous and exogenous cues have been well documented the model plant Arabidopsis. Novel allelic variation associated with circadian rhythms facilitates adaptation and range expansion, and may provide additional opportunity to tailor climate-resilient crops. The circadian phase and period can determine adaptation to environments, while the robustness in the circadian amplitude can enhance resilience to environmental changes. Circadian rhythms in plants are tightly controlled by multiple and interlocked transcriptional-translational feedback loops involving morning (CCA1, LHY), mid-day (PRR9, PRR7, PRR5), and evening (TOC1, ELF3, ELF4, LUX) genes that maintain the plant circadian clock ticking. Significant progress has been made to unravel the functions of circadian rhythms and clock genes that regulate traits, via interaction with phytohormones and trait-responsive genes, in diverse crops. Altered circadian rhythms and clock genes may contribute to hybrid vigor as shown in Arabidopsis, maize, and rice. Modifying circadian rhythms via transgenesis or genome-editing may provide additional opportunities to develop crops with better buffering capacity to environmental stresses. Models that involve clock gene‒phytohormone‒trait interactions can provide novel insights to orchestrate circadian rhythms and modulate clock genes to facilitate breeding of all season crops.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Relojes Circadianos , Relojes Circadianos/genética , Arabidopsis/genética , Reguladores del Crecimiento de las Plantas , Fitomejoramiento , Alelos , Productos Agrícolas/genética , Factores de Transcripción/genética
4.
BMC Microbiol ; 24(1): 239, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38961321

RESUMEN

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


Asunto(s)
Bacterias , Microbioma Gastrointestinal , ARN Ribosómico 16S , Estaciones del Año , Animales , Microbioma Gastrointestinal/genética , ARN Ribosómico 16S/genética , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , China , Ecosistema , Filogenia , Acuicultura , Lubina/microbiología , Secuenciación de Nucleótidos de Alto Rendimiento , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Biodiversidad
5.
New Phytol ; 243(6): 2486-2500, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39049577

RESUMEN

Changes to flowering phenology are a key response of plants to climate change. However, we know little about how these changes alter temporal patterns of reproductive overlap (i.e. phenological reassembly). We combined long-term field (1937-2012) and herbarium records (1850-2017) of 68 species in a flowering plant community in central North America and used a novel application of Bayesian quantile regression to estimate changes to flowering season length, altered richness and composition of co-flowering assemblages, and whether phenological shifts exhibit seasonal trends. Across the past century, phenological shifts increased species' flowering durations by 11.5 d on average, which resulted in 94% of species experiencing greater flowering overlap at the community level. Increases to co-flowering were particularly pronounced in autumn, driven by a greater tendency of late season species to shift the ending of flowering later and to increase flowering duration. Our results demonstrate that species-level phenological shifts can result in considerable phenological reassembly and highlight changes to flowering duration as a prominent, yet underappreciated, effect of climate change. The emergence of an autumn co-flowering mode emphasizes that these effects may be season-dependent.


Asunto(s)
Cambio Climático , Flores , Estaciones del Año , Flores/fisiología , Biodiversidad , Factores de Tiempo , Especificidad de la Especie , Reproducción/fisiología , Teorema de Bayes
6.
New Phytol ; 241(6): 2379-2394, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38245858

RESUMEN

Increasing rainfall variability is widely expected under future climate change scenarios. How will savanna trees and grasses be affected by growing season dry spells and altered seasonality and how tightly coupled are tree-grass phenologies with rainfall? We measured tree and grass responses to growing season dry spells and dry season rainfall. We also tested whether the phenologies of 17 deciduous woody species and the Soil Adjusted Vegetation Index of grasses were related to rainfall between 2019 and 2023. Tree and grass growth was significantly reduced during growing season dry spells. Tree growth was strongly related to growing season soil water potentials and limited to the wet season. Grasses can rapidly recover after growing season dry spells and grass evapotranspiration was significantly related to soil water potentials in both the wet and dry seasons. Tree leaf flushing commenced before the rainfall onset date with little subsequent leaf flushing. Grasses grew when moisture became available regardless of season. Our findings suggest that increased dry spell length and frequency in the growing season may slow down tree growth in some savannas, which together with longer growing seasons may allow grasses an advantage over C3 plants that are advantaged by rising CO2 levels.


Asunto(s)
Pradera , Poaceae , Poaceae/fisiología , Ecosistema , Árboles/fisiología , Suelo , Estaciones del Año , Agua
7.
J Med Virol ; 96(4): e29602, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38597349

RESUMEN

China experienced severe epidemics of multiple respiratory pathogens in 2023 after lifting "Zero-COVID" policy. The present study aims to investigate the changing circulation and infection patterns of respiratory pathogens in 2023. The 160 436 laboratory results of influenza virus and respiratory syncytial virus (RSV) from February 2020 to December 2023, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from June 2020 to December 2023, Mycoplasma pneumoniae, adenovirus, and human rhinovirus from January 2023 to December 2023 were analyzed. We observed the alternating epidemics of SARS-CoV-2 and influenza A virus (IAV), as well as the out-of-season epidemic of RSV during the spring and summer of 2023. Cocirculation of multiple respiratory pathogens was observed during the autumn and winter of 2023. The susceptible age range of RSV in this winter epidemic (10.5, interquartile range [IQR]: 5-30) was significantly higher than previously (4, IQR: 3-34). The coinfection rate of IAV and RSV in this winter epidemic (0.695%) was significantly higher than that of the last cocirculation period (0.027%) (p < 0.001). Similar trend was also found in the coinfection of IAV and SARS-CoV-2. The present study observed the cocirculation of multiple respiratory pathogens, changing age range of susceptible population, and increasing coinfection rates during the autumn and winter of 2023, in Beijing, China.


Asunto(s)
Coinfección , Virus de la Influenza A , Gripe Humana , Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Infecciones del Sistema Respiratorio , Humanos , Estudios Retrospectivos , Infecciones del Sistema Respiratorio/epidemiología , Beijing/epidemiología , Estaciones del Año , Coinfección/epidemiología , China/epidemiología , SARS-CoV-2 , Gripe Humana/epidemiología , Infecciones por Virus Sincitial Respiratorio/epidemiología
8.
Plant Cell Environ ; 47(3): 976-991, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38164069

RESUMEN

Mosses are vital components of ecosystems, exhibiting remarkable adaptability across diverse habitats from deserts to polar ice caps. Sanionia uncinata (Hedw.) Loeske, a dominant Antarctic moss survives extreme environmental condition through perennial lifecycles involving growth and dormancy alternation. This study explores genetic controls and molecular mechanisms enabling S. uncinata to cope with seasonality of the Antarctic environment. We analysed the seasonal transcriptome dynamics of S. uncinata collected monthly from February 2015 to January 2016 in King George Island, Antarctica. Findings indicate that genes involved in plant growth were predominantly upregulated in Antarctic summer, while those associated with protein synthesis and cell cycle showed marked expression during the winter-to-summer transition. Genes implicated in cellular stress and abscisic acid signalling were highly expressed in winter. Further, validation included a comparison of the Antarctic field transcriptome data with controlled environment simulation of Antarctic summer and winter temperatures, which revealed consistent gene expression patterns in both datasets. This proposes a seasonal gene regulatory model of S. uncinate to understand moss adaptation to extreme environments. Additionally, this data set is a valuable resource for predicting genetic responses to climatic fluctuations, enhancing our knowledge of Antarctic flora's resilience to global climate change.


Asunto(s)
Briófitas , Briófitas/genética , Ecosistema , Regiones Antárticas , Nieve , Ambientes Extremos , Perfilación de la Expresión Génica
9.
Glob Chang Biol ; 30(5): e17304, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38711381

RESUMEN

Subtropical forests, recognized for their intricate vertical canopy stratification, exhibit high resistance to extreme drought. However, the response of leaf phenology to drought in the species-rich understory remains poorly understood. In this study, we constructed a digital camera system, amassing over 360,000 images through a 70% throughfall exclusion experiment, to explore the drought response of understory leaf phenology. The results revealed a significant advancement in understory leaf senescence phenology under drought, with 11.75 and 15.76 days for the start and end of the leaf-falling event, respectively. Pre-season temperature primarily regulated leaf development phenology, whereas soil water dominated the variability in leaf senescence phenology. Under drought conditions, temperature sensitivities for the end of leaf emergence decreased from -13.72 to -11.06 days °C-1, with insignificance observed for the start of leaf emergence. Consequently, drought treatment shortened both the length of the growing season (15.69 days) and the peak growth season (9.80 days) for understory plants. Moreover, this study identified diverse responses among intraspecies and interspecies to drought, particularly during the leaf development phase. These findings underscore the pivotal role of water availability in shaping understory phenology patterns, especially in subtropical forests.


Asunto(s)
Sequías , Hojas de la Planta , Estaciones del Año , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/fisiología , Temperatura , Bosques , Agua/metabolismo , Árboles/crecimiento & desarrollo , Árboles/fisiología , Suelo , Clima Tropical , China
10.
Glob Chang Biol ; 30(4): e17260, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38563236

RESUMEN

The impact of anthropogenic global warming has induced significant upward dispersal of trees to higher elevations at alpine treelines. Assessing vertical deviation from current uppermost tree distributions to potential treeline positions is crucial for understanding ecosystem responses to evolving global climate. However, due to data resolution constraints and research scale limitation, comprehending the global pattern of alpine treeline elevations and driving factors remains challenging. This study constructed a comprehensive quasi-observational dataset of uppermost tree distribution across global mountains using Google Earth imagery. Validating the isotherm of mean growing-season air temperature at 6.6 ± 0.3°C as the global indicator of thermal treeline, we found that around two-thirds of uppermost tree distribution records significantly deviated from it. Drought conditions constitute the primary driver in 51% of cases, followed by mountain elevation effect which indicates surface heat (27%). Our analyses underscore the multifaceted determinants of global patterns of alpine treeline, explaining divergent treeline responses to climate warming. Moisture, along with temperature and disturbance, plays the most fundamental roles in understanding global variation of alpine treeline elevation and forecasting alpine treeline response to ongoing global warming.


Asunto(s)
Ecosistema , Árboles , Árboles/fisiología , Temperatura , Frío , Clima , Altitud
11.
Glob Chang Biol ; 30(3): e17231, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38481067

RESUMEN

Leaf coloring and fall mark the end of the growing season (EOS), playing essential roles in nutrient cycling, resource allocation, ecological interactions, and as climate change indicators. However, understanding future changes in autumn phenology is challenging due to the multitude of likely environmental cues and substantial variations in timing caused by different derivation methods. Yet, it remains unclear whether these two factors are independent or if methodological uncertainties influence the environmental cues determined. We derived start of growing season (SOS) and EOS at a mixed beech forest in Central Germany for the period 2000-2020 based on four different derivation methods using a unique long-term data set of in-situ data, canopy imagery, eddy covariance measurements, and satellite remote sensing data and determined their influence on a predictor analysis of leaf senescence. Both SOS and EOS exhibited substantial ranges in mean onset dates (39.5 and 28.6 days, respectively) across the different methods, although inter-annual variations and advancing SOS trends were similar across methods. Depending on the data, EOS trends were advanced or delayed, but inter-annual patterns correlated well (mean r = .46). Overall, warm, dry, and less photosynthetically productive growing seasons were more likely to be associated with a delayed EOS, while colder, wetter, and more photosynthetically productive vegetation periods resulted in an earlier EOS. In addition, contrary to recent results, no clear influence of pre-solstice vegetation activity on the timing of senescence was detected. However, most notable were the large differences in sign and strength of potential drivers both in the univariate and multivariate analyses when comparing derivation methodologies. The results suggest that an ensemble analysis of all available phenological data sources and derivation methods is needed for general statements on autumn phenology and its influencing variables and correct implementation of the senescence process in ecosystem models.


Asunto(s)
Señales (Psicología) , Ecosistema , Estaciones del Año , Temperatura , Bosques , Cambio Climático
12.
J Exp Biol ; 227(8)2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38516936

RESUMEN

In temperate climates, honey bees show strong phenotypic plasticity associated with seasonal changes. In summer, worker bees typically only survive for about a month and can be further classified as young nurse bees (which feed the developing brood) and older forager bees. In winter, brood production and foraging halt and the worker bees live for several months. These differences in task and longevity are reflected in their physiology, with summer nurses and long-lived winter bees typically having large fat bodies, high expression levels of vitellogenin (a longevity-, nutrition- and immune-related gene), and large provisioning glands in their head. The environmental factors (both within the colony and within the surrounding environment) that trigger this transition to long-lived winter bees are poorly understood. One theory is that winter bees are an extended nurse bee state, brought on by a reduction in nursing duties in autumn (i.e. lower brood area). We examined that theory here by assessing nurse bee physiology in both the summer and autumn, in colonies with varying levels of brood. We found that season is a better predictor of nurse bee physiology than brood area. This suggests that seasonal factors beyond brood area, such as pollen availability and colony demography, may be necessary for inducing the winter bee phenotype. This finding furthers our understanding of winter bee biology, which could have important implications for colony management for winter, a critical period for colony survival.


Asunto(s)
Medio Social , Vitelogeninas , Abejas , Animales , Humanos , Estaciones del Año
13.
J Sleep Res ; : e14225, 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39039613

RESUMEN

The interplay of daily life factors, including mood, physical activity, or light exposure, influences sleep architecture and quality. Laboratory-based studies often isolate these determinants to establish causality, thereby sacrificing ecological validity. Furthermore, little is known about time-of-year changes in sleep and circadian-related variables at high resolution, including the magnitude of individual change across time of year under real-world conditions. The Ecology of Human Sleep (EcoSleep) cohort study will investigate the combined impact of sleep determinants on individuals' daily sleep episodes to elucidate which waking events modify sleep patterns. A second goal is to describe high-resolution individual sleep and circadian-related changes across the year to understand intra- and inter-individual variability. This study is a prospective cohort study with a measurement-burst design. Healthy adults aged 18-35 years (N = 12) will be enrolled for 12 months. Participants will continuously wear actimeters and pendant-attached light loggers. A subgroup will also measure interstitial fluid glucose levels (six paticipants). Every 4 weeks, all participants will undergo three consecutive measurement days of four ecological momentary assessments each day ('bursts') to sample sleep determinants during wake. Participants will also continuously wear temperature loggers (iButtons) during the bursts. Body weight will be captured before and after the bursts in the laboratory. The bursts will be separated by two at-home electroencephalogram recordings each night. Circadian phase and amplitude will be estimated during the bursts from hair follicles, and habitual melatonin onset will be derived through saliva sampling. Environmental parameters (bedroom temperature, humidity, and air pressure) will be recorded continuously.

14.
Malar J ; 23(1): 274, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39256741

RESUMEN

BACKGROUND: Malaria remains an important public health problem, particularly in sub-Saharan Africa. In Rwanda, where malaria ranks among the leading causes of mortality and morbidity, disease transmission is influenced by climatic factors. However, there is a paucity of studies investigating the link between climate change and malaria dynamics, which hinders the development of effective national malaria response strategies. Addressing this critical gap, this study analyses how climatic factors influence malaria transmission across Rwanda, thereby informing tailored interventions and enhancing disease management frameworks. METHODS: The study analysed the potential impact of temperature and cumulative rainfall on malaria incidence in Rwanda from 2012 to 2021 using meteorological data from the Rwanda Meteorological Agency and malaria case records from the Rwanda Health Management and Information System. The analysis was performed in two stages. First, district-specific generalized linear models with a quasi-Poisson distribution were applied, which were enhanced by distributed lag non-linear models to explore non-linear and lagged effects. Second, random effects multivariate meta-analysis was employed to pool the estimates and to refine them through best linear unbiased predictions. RESULTS: A 1-month lag with specific temperature and rainfall thresholds influenced malaria incidence across Rwanda. Average temperature of 18.5 °C was associated with higher malaria risk, while temperature above 23.9 °C reduced the risk. Rainfall demonstrated a dual effect on malaria risk: conditions of low (below 73 mm per month) and high (above 223 mm per month) precipitation correlated with lower risk, while moderate rainfall (87 to 223 mm per month) correlated with higher risk. Seasonal patterns showed increased malaria risk during the major rainy season, while the short dry season presented lower risk. CONCLUSION: The study underscores the influence of temperature and rainfall on malaria transmission in Rwanda and calls for tailored interventions that are specific to location and season. The findings are crucial for informing policy that enhance preparedness and contribute to malaria elimination efforts. Future research should explore additional ecological and socioeconomic factors and their differential contribution to malaria transmission.


Asunto(s)
Cambio Climático , Malaria , Lluvia , Temperatura , Rwanda/epidemiología , Malaria/epidemiología , Malaria/transmisión , Incidencia , Humanos , Estaciones del Año , Clima
15.
Am J Bot ; 111(2): e16286, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38366863

RESUMEN

PREMISE: In frequently burned southeastern USA pine-grassland communities, wiregrass (Aristida stricta and A. beyrichiana) are dominant bunchgrasses whose flowers are infected during flowering by a smut fungus (Langdonia walkerae). We hypothesized that because prescribed fire timing affects wiregrass flowering patterns, it could affect smut incidence (occurrence of smut on plants) and severity of infection in inflorescences and spikelets. Because soil order could influence plant susceptibility, we hypothesized that these patterns would differ between soil orders. We hypothesized differences between species as representative of geographic variation in this ecosystem. METHODS: We surveyed the incidence and severity of L. walkerae in wiregrass populations (85 populations at 14 sites) that had been prescription burned at different times during the previous year. We used binomial regressions to test whether incidence and severity differed by burn day, soil order, or species, with site as a random effect. RESULTS: Fires that occurred in the winter were associated with significantly lower incidence than fires later in the year (as the months progressed into summer). Plants growing on Spodosol soils were significantly less likely to be infected than those on other soils. More variation in incidence, however, was explained by site, suggesting that site-specific characteristics were important. Smut severity in inflorescences and spikelets was greater overall in populations of A. stricta than in southern populations (A. beyrichiana). CONCLUSIONS: Our findings indicate that fire timing and soil order affect L. walkerae incidence in wiregrass plants, but neither appears to be associated with greater severity. Patterns of smut infection are related to site history and geographic variation.


Asunto(s)
Ecosistema , Incendios , Incidencia , Poaceae , Suelo , Hongos
16.
J Med Primatol ; 53(2): e12695, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38454195

RESUMEN

BACKGROUND: Type 2 Diabetes Mellitus (T2D) is a chronic disease with a high prevalence worldwide. Human literature suggests factors beyond well-known risk factors (e.g., age, body mass index) for T2D: cytomegalovirus serostatus, season of birth, maternal age, birth weight, and depression. Nothing is known, however, about whether these variables are influential in primate models of T2D. METHODS: Using a retrospective methodology, we identified 22 cases of spontaneously occurring T2D among rhesus monkeys at our facility. A control sample of n = 1199 was identified. RESULTS: Animals born to mothers that were ≤5.5 years of age, and animals that showed heightened Activity and Emotionality in response to brief separation in infancy, had a greater risk for development of T2D in adulthood. CONCLUSIONS: Knowledge of additional risk factors for T2D could help colony managers better identify at-risk animals and enable diabetes researchers to select animals that might be more responsive to their manipulations.


Asunto(s)
Diabetes Mellitus Tipo 2 , Humanos , Animales , Macaca mulatta/fisiología , Diabetes Mellitus Tipo 2/etiología , Diabetes Mellitus Tipo 2/veterinaria , Estudios Retrospectivos , Factores de Riesgo
17.
Environ Sci Technol ; 58(17): 7415-7424, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38578215

RESUMEN

We found that a winter of abnormally low snowfall and numerous dust storms from eolian processes acting on exposed landscapes (including a major 4-day dust storm while onsite in May 2014) caused a cascade of impacts on the physical, chemical, and ecological functioning of the largest lake by volume in the High Arctic (Lake Hazen; Nunavut, Canada). MODIS imagery revealed that dust deposited in snowpacks on the lake's ice acted as light-absorbing impurities (LAIs), reducing surface reflectance and increasing surface temperatures relative to normal snowpack years, causing early snowmelt and drainage of meltwaters into the lake. LAIs remaining on the ice surface melted into the ice, causing premature candling and one of the earliest ice-offs and longest ice-free seasons on record for Lake Hazen. Meltwater inputs from snowpacks resulted in dilution of dissolved, and increased concentration of particulate bound, chemical species in Lake Hazen's upper water column. Spring inputs of nutrients increased both heterotrophy and algal productivity under the surface ice following snowmelt, with a net consumption of dissolved oxygen. As climate change continues to alter High Arctic temperatures and precipitation patterns, we can expect further changes in dust storm frequency and severity with corresponding impacts for freshwater ecosystems.


Asunto(s)
Polvo , Lagos , Estaciones del Año , Regiones Árticas , Nieve , Cambio Climático
18.
Oecologia ; 204(1): 59-69, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38091103

RESUMEN

Rising temperatures pose a threat to the stability of climate regulation by carbon metabolism in subtropical forests. Although the effects of temperature on leaf carbon metabolism traits in sun-exposed leaves are well understood, there is limited knowledge about its impacts on shade leaves and the implications for ecosystem-climate feedbacks. In this study, we measured temperature response curves of photosynthesis and respiration for 62 woody species in summer (including both evergreen and deciduous species) and 20 evergreen species in winter. The aim was to uncover the temperature dependence of carbon metabolism in both sun and shade leaves in subtropical forests. Our findings reveal that shade had no significant effects on the mean optimum photosynthetic temperatures (TOpt) or temperature range (T90). However, there were decreases observed in mean stomatal conductance, mean area-based photosynthetic rates at TOpt and 25 °C, as well as mean area-based dark respiration rates at 25 °C in both evergreen and deciduous species. Moreover, the respiration-temperature sensitivity (Q10) of sun leaves was higher than that of shade leaves in winter, with the reverse being true in summer. Leaf economics spectrum traits, such as leaf mass per area, and leaf concentration of nitrogen and phosphorus across species, proved to be good predictors of TOpt, T90, mass-based photosynthetic rate at TOpt, and mass-based photosynthetic and respiration rate at 25 °C. However, Q10 was poorly predicted by these leaf economics spectrum traits except for shade leaves in winter. Our results suggest that model estimates of carbon metabolism in multilayered subtropical forest canopies do not necessitate independent parameterization of T90 and TOpt temperature responses in sun and shade leaves. Nevertheless, a deeper understanding and quantification of canopy variations in Q10 responses to temperature are necessary to confirm the generality of temperature-carbon metabolism trait responses and enhance ecosystem model estimates of carbon dynamics under future climate warming.


Asunto(s)
Ecosistema , Árboles , Temperatura , Árboles/fisiología , Hojas de la Planta/fisiología , Bosques , Fotosíntesis/fisiología
19.
J Asthma ; 61(7): 745-753, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38193466

RESUMEN

INTRODUCTION: Asthma is a chronic heterogeneous disease with characteristic symptoms, but with proper treatment the patient can lead a full life. In patients with allergic asthma, symptoms appear after irritation with an allergen, most often in the pollen season. In 2019, the viral disease COVID-19 appeared, which, especially in people with asthma, led not only to an asthma attack, but also to other serious diseases. METHODS: The main aim was to investigate differences in patients' health status by comparing spirometric values in and out of pollen season (A), spirometric values before and after COVID-19 viral illness (B) and an anonymous questionnaire (C). Spirometric values were recorded in each patient (control group - patients diagnosed with asthma, research group - patients after overcoming COVID-19 disease) in 3 cycles, namely (in the pollen period, in the non-pollen period and after overcoming COVID-19 disease - at an interval of 2 months after a negative PCR test). RESULTS: We observed significant results during the individual spirometry performed (A) during the pollen season and non-pollen season. We observed the same in patients after they received COVID-19 treatment (B). Patients were also asked questions regarding family history, symptoms and their variability, worsening of the condition or correct inhalation technique (C). CONCLUSION: Our research shows that the PEF parameter is most affected by the pollen and non-pollen season in asthmatic patients. Significant differences in PEF parameter were observed between genders, where we observed highly significant statistical significance of PEF parameter in pollen and non-pollen season in females.


Asunto(s)
Asma , COVID-19 , Polen , Estaciones del Año , Espirometría , Humanos , COVID-19/epidemiología , Femenino , Masculino , Adulto , Persona de Mediana Edad , Polen/inmunología , Eslovaquia/epidemiología , Encuestas y Cuestionarios , Asma/fisiopatología , SARS-CoV-2 , Rinitis Alérgica Estacional/fisiopatología , Rinitis Alérgica Estacional/epidemiología , Adulto Joven , Anciano
20.
Audiol Neurootol ; 29(4): 290-296, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38402865

RESUMEN

INTRODUCTION: Several studies have reported that the number of patients with Bell's palsy varied significantly by month and season. However, few studies have reported the monthly variation in Bell's palsy based on the whole population. We investigated the monthly variation in Bell's palsy in Korea during a long-term period based on whole population data. METHODS: This retrospective study used the data of the National Health Insurance Service of Korea, which included the entire Korean population from 2008 to 2020. The monthly incidence of Bell's palsy per 100,000 was evaluated in total and according to sex, age, and residence. RESULTS: The total average monthly incidence differed significantly by month, with the highest observed in January (9.1 per 100,000) and the lowest in June (7.7 per 100,000) (p < 0.001). The average monthly incidence according to sex, age, and residence also varied significantly by month, with most of the highest values noted in January and the lowest in June. CONCLUSION: There was significant monthly variation in the incidence of Bell's palsy, with the highest in January during the winter and the lowest in June during the summer, based on whole population data over a long-term period in Korea.


Asunto(s)
Parálisis de Bell , Estaciones del Año , Parálisis de Bell/epidemiología , Humanos , República de Corea/epidemiología , Masculino , Femenino , Persona de Mediana Edad , Adulto , Incidencia , Estudios Retrospectivos , Anciano , Adulto Joven , Adolescente , Niño , Preescolar , Lactante , Anciano de 80 o más Años , Recién Nacido
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA