RESUMO
Respiratory sinus arrhythmia (RSA), an index of the parasympathetic nervous system activity, has been considered indicative of stress response and emotion regulation. However, the relationship between RSA and anxiety remains inconclusive, partly because previous research has primarily focused on static RSA levels. In this nonclinical sample (N = 75, Mage = 20.89 ± 1.72 SD, 48 males), we used a damped oscillator model to characterize RSA dynamics across 30-s epochs while participants completed the Trier social stress test. Results showed that RSA constantly oscillated during the three periods of TSST (namely Rest, Stress, and Recovery). Importantly, slower RSA oscillation in the Stress period was related to elevated state anxiety, whereas in the Recovery period, it was related to higher trait anxiety. These findings demonstrated the dynamic nature of RSA during the whole course of stress response. Slower RSA oscillation may indicate inflexible and tardy physiological regulation which may give rise to anxiety issues.
Assuntos
Ansiedade , Arritmia Sinusal Respiratória , Estresse Psicológico , Humanos , Masculino , Arritmia Sinusal Respiratória/fisiologia , Estresse Psicológico/fisiopatologia , Adulto Jovem , Feminino , Ansiedade/fisiopatologia , Adulto , Regulação Emocional/fisiologia , Adolescente , Sistema Nervoso Parassimpático/fisiopatologia , Sistema Nervoso Parassimpático/fisiologiaRESUMO
BACKGROUND: Lithophytic bryophytes grow on the rock surface, change the habitat on the rock surface through biological karstification, and provide a material basis for the growth of other plants. However, the surface calcium content of bare rock is high. The lithophytic bryophytes may have a special mechanism to adapt to the karst high calcium environment. The present study aimed to explore the physiological regulation process of karst lithophytic bryophytes under high calcium environment, and to provide scientific basis for revealing the maintenance mechanism of karst biodiversity. RESULTS: With the increase of Ca2+ concentration, the contents of Pro, SP and MDA of lithophytic bryophytes showed a downward-upward-downward trend. However, when Ca2+ ≥ 400 mmol/L, the contents of Pro and SP changed significantly at 1d, 2d, 3d, 5d and 7d with the extension of culture time, and lithophytic bryophytes died after 2 months of culture. Under different Ca2+ concentrations, the maximum SOD activity of lithophytic bryophytes is 1758.00 (U/g FW), the minimum is 92.60 (U/g FW), the maximum POD activity is 120.88 (U/g FW), and the minimum is 4.80 (U/g FW). The antioxidative activity of of Hyophila involuta are higher than that of Didymodon constrictus and Eurohypnum leptothallum, and its enzyme activity changed significantly with the increase of calcium concentration and time.At the same time, the contents of TChl, Chla, and Chlb in lithophytic bryophytes decreased with the increase of Ca2+ concentration. When Ca2+ = 400 mmol/L, the contents of TChl and Chla were the lowest, but when Ca2+ > 400 mmol/L, they began to increase. In addition, ABA is negatively correlated with TChl and Chla, and positively correlated with ROS. It shows that ABA has a certain role in regulating the adaptation of lithophytic bryophytes to high calcium environment. CONCLUSIONS: Lithophytic bryophytes have strong calcium tolerance, and their physiological response to high calcium stress is different from vascular bundle plants. The general stress principle is not applicable to lithophytic bryophytes. The response of lithophytic bryophytes to the change of Ca2+concentration is slow, showing passive response or inert response.
Assuntos
Briófitas , Bryopsida , Cálcio , Ecossistema , Adaptação FisiológicaRESUMO
The depth of the substrate of subsurface flow (SSF) constructed wetlands (CWs) is closely related to their cost and operation stability. To explore the physiological regulation mechanism of wetland plants and pollutant removal potential of SSF CWs under "vertical spatial stress of roots" (by greatly reducing the depth of the substrate in SSF CWs to limit the vertical growth space of roots, VSSR), the physiological response and wetland purification effect of a 0.1 m Canna indica L. CW under VSSR were studied compared with conventional SSF CWs (0.6 m, 1.2 m). The results demonstrated that VSSR significantly enhanced the dissolved oxygen (DO) concentration (p < 0.05) within the SSF CWs, with the DO in 0.1 m CW remaining stable at over 3 mg/L. Under the same hydraulic retention time (HRT), VSSR significantly improved the removal effect of pollutants (p < 0.05). The removal rates of COD, NH4+-N, and total phosphorus (TP) remained above 87%, and the mean removal rates of total nitrogen (TN) reached 91.71%. VSSR promoted the morphological adaptation mechanisms of plants, such as significantly increased root-shoot ratio (p < 0.05), changed biomass allocation. Plants could maintain the stability of the photosynthetic mechanism by changing the distribution of light energy. The results of microbial community function prediction demonstrated that aerobic denitrification was the main mechanism of N transformation in the 0.1 m CW under VSSR. VSSR could induce the high root activity of plants, augment the concentration of root exudates, enhance the redox environment of the plant rhizosphere, further foster the enrichment of aerobic denitrifying bacteria, and strengthen the absorption efficiency of wetland plants and substrate, thus achieving an efficient pollutant removal capacity. Studies showed that VSSR was an effective means to enhance the rhizosphere effect of plants and pollutant removal in SSF CWs.
Assuntos
Poluentes Ambientais , Eliminação de Resíduos Líquidos , Eliminação de Resíduos Líquidos/métodos , Áreas Alagadas , Rizosfera , Plantas , Nitrogênio/análiseRESUMO
Porges' polyvagal theory (1991) proposes that the activity of the vagal nerve modulates moment-by-moment changes in adaptive behavior during stress. However, most work, including research with infants, has only examined vagal changes at low temporal resolutions, averaging 30+ s across phases of structured stressor paradigms. Thus, the true timescale of vagal regulation-and the extent to which it can be observed during unprompted crying-is unknown. The current study utilized a recently validated method to calculate respiratory sinus arrhythmia (RSA) dynamically at a high resolution of 5 Hz (updated every 200 ms) in a home-based infant study. Using an event-related analysis, we calculated the relative change in RSA around the onset of naturally occurring unprompted instances of n = 41 infants' 180 crying events. As predicted, RSA significantly decreased after the onset of crying compared to non-crying chance changes in RSA. Decreasing trends in RSA were driven by infants with higher pre-cry RSA values, infants rated lower in Negative Affectivity, and those rated both high and low in Orienting by their mothers. Our results display the timescale of RSA in spontaneous and naturalistic episodes of infant crying and that these dynamic RSA patterns are aligned with real-time levels of RSA and also caregiver-reported temperament.
Assuntos
Choro , Arritmia Sinusal Respiratória , Feminino , Humanos , Lactente , Choro/fisiologia , Nervo Vago/fisiologia , Mães , Arritmia Sinusal Respiratória/fisiologia , Arritmia SinusalRESUMO
This study examined the extent to which mothers' physiological arousal (i.e., skin conductance level [SCL] augmentation) and regulation (i.e., respiratory sinus arrhythmia [RSA] withdrawal) interacted to predict subsequent maternal sensitivity. Mothers' (N = 176) SCL and RSA were measured prenatally during a resting baseline and while watching videos of crying infants. Maternal sensitivity was observed during a free-play task and the still-face paradigm when their infants were 2 months old. The results demonstrated that higher SCL augmentation but not RSA withdrawal predicted more sensitive maternal behaviors as a main effect. Additionally, SCL augmentation and RSA withdrawal interacted, such that well-regulated maternal arousal was associated with greater maternal sensitivity at 2 months. Further, the interaction between SCL and RSA was only significant for the negative dimensions of maternal behavior used to derive the measure of maternal sensitivity (i.e., detachment and negative regard) suggesting that well-regulated arousal is particularly important for inhibiting the tendency to engage in negative maternal behaviors. The results replicate findings from mothers in previous studies and demonstrate that the interactive effects of SCL and RSA in relation to parenting outcomes are not sample specific. Considering joint effects of physiological responding across multiple biological systems may enhance understanding of the antecedents of sensitive maternal behavior.
Assuntos
Relações Mãe-Filho , Arritmia Sinusal Respiratória , Feminino , Lactente , Humanos , Comportamento Materno/fisiologia , Mães , Nível de Alerta/fisiologiaRESUMO
The water lily (Nymphaea tetragona) is an ancient angiosperm that belongs to the Nymphaeaceae family. As a rooted floating-leaf plant, water lilies are generally cultivated in fresh water, therefore, little is known about their survival strategies under salt stress. Long-term salt stress causes morphological changes, such as the rapid regeneration of floating leaves and a significant decrease in leaf number and surface area. We demonstrate that salt stress induces toxicity soon after treatment, but plants can adapt by regenerating floating leaves that are photosynthetically active. Transcriptome profiling revealed that ion binding was one of the most-enriched GO terms in leaf-petiole systems under salt stress. Sodium-transporter-related genes were downregulated, whereas K+ transporter genes were both up- and downregulated. These results suggest that restricting intracellular Na+ importing while maintaining balanced K+ homeostasis is an adaptive strategy for tolerating long-term salt stress. ICP-MS analysis identified the petioles and leaves as Na-hyperaccumulators, with a maximum content of over 80 g kg-1 DW under salt stress. Mapping of the Na-hyperaccumulation trait onto the phylogenetic relationships revealed that water lily plants might have a long evolutionary history from ancient marine plants, or may have undergone historical ecological events from salt to fresh water. Ammonium transporter genes involved in nitrogen metabolism were downregulated, whereas NO3--related transporters were upregulated in both the leaves and petioles, suggesting a selective bias toward NO3- uptake under salt stress. The morphological changes we observed may be due to the reduced expression of genes related to auxin signal transduction. In conclusion, the floating leaves and submerged petioles of the water lily use a series of adaptive strategies to survive salt stress. These include the absorption and transport of ions and nutrients from the surrounding environments, and the ability to hyperaccumulate Na+. These adaptations may serve as the physiological basis for salt tolerance in water lily plants.
Assuntos
Nymphaea , Filogenia , Estresse Salino , Folhas de Planta/metabolismo , Tolerância ao Sal/genética , Regulação da Expressão Gênica de Plantas , Estresse FisiológicoRESUMO
Body size has fundamental impacts on animal ecology and physiology but has been strongly influenced by recent climate change and human activities, such as size-selective harvesting. Understanding the ecological and life history consequences of body size has proved difficult due to the inseparability of direct effects of body size from processes connected to it (such as growth rate and individual condition). Here, we used the cnidarian Hydra oligactis to directly manipulate body size and understand its causal effects on reproduction and senescence. We found that experimentally reducing size delayed sexual development and lowered fecundity, while post-reproductive survival increased, implying that smaller individuals can physiologically detect their reduced size and adjust life history decisions to achieve higher survival. Our experiment suggests that ecological or human-induced changes in body size will have immediate effects on life history and population dynamics through a growth-independent link between body size, reproduction and senescence.
Assuntos
Hydra , Animais , Tamanho Corporal , Fertilidade , Humanos , Dinâmica Populacional , ReproduçãoRESUMO
Autophagy exists widely in eukaryotic cells and is regulated by a variety of molecular mechanisms. Its physiological functions include providing energy, maintaining cell homeostasis, and promoting apoptosis of abnormal cells. At present, the regulation of autophagy in tumor, degenerative disease, and cardiovascular disease has attracted much attention. Gradually, the role of autophagy in pregnancy tends to be valued. The previous literature has shown that autophagy can influence the occurrence and maintenance of pregnancy from three aspects: embryo (affecting the process of fertilization and embryonic development and the function of trophoblast cells), maternal (decidualization), and maternal-to-fetal immune crosstalk. Undoubtedly, abnormalities in autophagy levels are associated with a variety of pregnancy complications, such as preeclampsia, fetal growth restriction, and preterm delivery which have been proven by human, animal, and in vitro experiments. The regulation of autophagy is expected to be a target for the treatment of these pregnancy complications. This article reviews the research on autophagy, especially about its physiological and pathological regulation during pregnancy.
Assuntos
Autofagia/fisiologia , Pré-Eclâmpsia/patologia , Trofoblastos/fisiologia , Animais , Desenvolvimento Embrionário , Feminino , Retardo do Crescimento Fetal/patologia , Humanos , Gravidez , Nascimento PrematuroRESUMO
In the current study, we evaluated the extent to which mothers reported emotion dysregulation on the Difficulties with Emotion Regulation Questionnaire (DERS) (a) converged with physiological indices of emotion dysregulation while parenting, (b) correlated with maternal sensitivity, and (c) predicted infant attachment disorganization and behavior problems in a sample of 259 mothers and their infants. When infants were 6 months old, mothers' physiological arousal and regulation were measured during parenting tasks and mothers completed the DERS. Maternal sensitivity was observed during distress-eliciting tasks when infants were 6 and 14 months old. Infant attachment disorganization was assessed during the Strange Situation when infants were 14 months old and mothers reported on infants' behavior problems when infants were 27 months old. Mothers who reported greater emotion regulation difficulties were more physiologically dysregulated during stressful parenting tasks and also showed lower levels of maternal sensitivity at 6 months. Mother-reported dysregulation predicted higher likelihood of infant attachment disorganization and more behavior problems. Results suggest that the DERS is a valid measure of maternal emotional dysregulation and may be a useful tool for future research and intervention efforts aimed toward promoting positive parenting and early child adjustment.
En el presente estudio, evaluamos el punto al cual la madre reporta la desregulación de la emoción en el Cuestionario de Dificultades con la Regulación de la Emoción (DERS) (1) presentaba una convergencia con índices fisiológicos de desregulación de la emoción durante la crianza, (2) se correlacionaba con la sensibilidad materna, y (3) predecía la desorganización de la afectividad del infante y problemas de comportamiento en un grupo muestra de 259 madres y sus infantes. Cuando los infantes tenían 6 meses de edad, se midió la excitación y regulación fisiológica de las madres durante tareas de crianza y las madres completaron el DERS. La sensibilidad de las madres fue observada durante una tarea que motivaba la angustia cuando los infantes tenían 6 y 14 meses de edad. La desorganización de la afectividad del infante fue evaluada durante una sesión de la Situación Extraña cuando los infantes tenían 14 meses de edad y las madres reportaron acerca de los problemas de comportamiento de los infantes cuando los infantes tenían 27 meses de edad. Las madres que reportaron mayores dificultades con la regulación de la emoción se encontraban más desreguladas fisiológicamente durante las estresantes tareas de crianza y también mostraron más bajos niveles de sensibilidad materna a los 6 meses. La desregulación reportada por las madres predijo una más alta propensión de la desorganización de afectividad del infante y más problemas de comportamiento. Los resultados sugieren que el DERS es una medida válida para la desregulación emocional materna y pudiera ser una herramienta útil para la futura investigación y los esfuerzos de intervención con miras a promover la crianza positiva y la adaptación temprana del niño. Palabras claves: regulación de la emoción, interacción madre-infante, desorganización de la afectividad, problemas de comportamiento, regulación fisiológica.
Dans cette étude nous avons évalué dans quelle mesure la dysrégulation de l'émotion rapportée par la mère dans le Questionnaire sur les Difficultés de Régulation de l'Emotion (DERS, soit en anglais Difficulties with Emotion Regulation Questionnaire) (1) convergeait avec des indices physiologiques de dysrégulation de l'émotion durant le parentage, (2) était liée à la sensibilité maternelle, et (3) prédisait la désorganisation de l'attachement du nourrisson et des problèmes de comportement chez un échantillon de 259 mères et leurs bébés. Lorsque les bébés ont atteint l'âge de soi moi, la stimulation physiologique des mères et la régulation ont été mesurées durant des exercices de parentage et les mères ont rempli le questionnaire DERS. La sensibilité maternelle a été observée durant les exercices déclenchant de la détresse quand les bébés avaient 6 et 14 mois. La désorganisation de l'attachement du bébé a été évaluée en utilisant la Situation Etrange lorsque les bébés avaient 14 mois et les mères ont fait état des problèmes de comportement de leurs bébés lorsque ceux-ci avaient 27 mois. Les mères ayant rapporté de plus grandes difficultés de régulation de l'émotion étaient plus dysrégulées physiologiquement durant les exercices de parentage stressant et faisaient également preuve de niveaux de sensibilité maternelle plus bas à six mois. La dysrégulation rapportée par la mère prédisait une plus grande propension à la désorganisation de l'attachement du bébé et plus de problèmes de comportement. Les résultats suggèrent que le questionnaire DERS est une mesure valide de la dysrégulation émotionnelle maternelle et peut être un outil utile pour les recherches à venir et les efforts d'intervention visant la promotion d'un parentage positive et l'ajustement précoce de l'enfant. Mots clés: régulation de l'émotion, interaction mère-bébé, désorganisation de l'attachement, problèmes de comportement, régulation physiologique.
Assuntos
Regulação Emocional/fisiologia , Comportamento do Lactente/fisiologia , Comportamento Materno/fisiologia , Mães , Poder Familiar , Comportamento Problema , Autorrelato/normas , Adulto , Feminino , Humanos , Lactente , Masculino , Mães/psicologia , Poder Familiar/psicologia , Reprodutibilidade dos TestesRESUMO
Local brain hypothermia is an attractive method for providing cerebral neuroprotection for ischemic stroke patients and at the same time reducing systemic side effects of cooling. In acute ischemic stroke patients with large vessel occlusion, combination with endovascular mechanical recanalization treatment could potentially allow for an alleviation of inflammatory and apoptotic pathways in the critical phase of reperfusion. The direct cooling of arterial blood by means of an intra-carotid heat exchange catheter compatible with recanalization systems is a novel promising approach. Focusing on the concept of "cold reperfusion", we developed an energetic model to calculate the rate of temperature decrease during intra-carotid cooling in case of physiological as well as decreased perfusion. Additionally, we discussed and considered the effect and biological significance of temperature decrease on resulting brain perfusion. Our model predicted a 2 °C brain temperature decrease in 8.3, 11.8 and 26.2 min at perfusion rates of 50, 30 and 10ml100gâ min, respectively. The systemic temperature decrease - caused by the venous blood return to the main circulation - was limited to 0.5 °C in 60 min. Our results underline the potential of catheter-assisted, intracarotid blood cooling to provide a fast and selective brain temperature decrease in the phase of vessel recanalization. This method can potentially allow for a tissue hypothermia during the restoration of the physiological flow and thus a "cold reperfusion" in the setting of mechanical recanalization.
Assuntos
Temperatura Corporal , Encéfalo/irrigação sanguínea , Encéfalo/fisiologia , Hipotermia Induzida , Infarto da Artéria Cerebral Média/terapia , Modelos Biológicos , Acidente Vascular Cerebral/terapia , Animais , Cateterismo , HumanosRESUMO
Variable-Internal-Stores models of microbial metabolism and growth have proven to be invaluable in accounting for changes in cellular composition as microbial cells adapt to varying conditions of nutrient availability. Here, such a model is extended with explicit allocation of molecular building blocks among various types of catalytic machinery. Such an extension allows a reconstruction of the regulatory rules employed by the cell as it adapts its physiology to changing environmental conditions. Moreover, the extension proposed here creates a link between classic models of microbial growth and analyses based on detailed transcriptomics and proteomics data sets. We ascertain the compatibility between the extended Variable-Internal-Stores model and the classic models, demonstrate its behaviour by means of simulations, and provide a detailed treatment of the uniqueness and the stability of its equilibrium point as a function of the availabilities of the various nutrients.
Assuntos
Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Meio Ambiente , Modelos Biológicos , Simulação por Computador , Proteoma , TranscriptomaRESUMO
Environmental temperature has profound effects on animal physiology, ecology, and evolution. Glucocorticoid (GC) hormones, through effects on phenotypic performance and life history, provide fundamental vertebrate physiological adaptations to environmental variation, yet we lack a comprehensive understanding of how temperature influences GC regulation in vertebrates. Using field studies and meta- and comparative phylogenetic analyses, we investigated how acute change and broadscale variation in temperature correlated with baseline and stress-induced GC levels. Glucocorticoid levels were found to be temperature and taxon dependent, but generally, vertebrates exhibited strong positive correlations with acute changes in temperature. Furthermore, reptile baseline, bird baseline, and capture stress-induced GC levels to some extent covaried with broadscale environmental temperature. Thus, vertebrate GC function appears clearly thermally influenced. However, we caution that lack of detailed knowledge of thermal plasticity, heritability, and the basis for strong phylogenetic signal in GC responses limits our current understanding of the role of GC hormones in species' responses to current and future climate variation.
Assuntos
Adaptação Fisiológica , Glucocorticoides/metabolismo , Temperatura , Vertebrados/fisiologia , Animais , FilogeniaRESUMO
Environmental temperature gradients provide habitat structure in which fish orientate and individual thermal choice may reflect an essential integrated response to the environment. The use of subtle thermal gradients likely impacts upon specific physiological and behavioural processes reflected as a suite of traits described by animal personality. In this study, we examine the relationship between thermal choice, animal personality and the impact of infection upon this interaction. We predicted that thermal choice in Nile tilapia Oreochromis niloticus reflects distinct personality traits and that under a challenge individuals exhibit differential thermal distribution. Nile tilapia were screened following two different protocols: 1) a suite of individual behavioural tests to screen for personality and 2) thermal choice in a custom-built tank with a thermal gradient (TCH tank) ranging from 21 to 33 °C. A first set of fish were screened for behaviour and then thermal preference, and a second set were tested in the opposite fashion: thermal then behaviour. The final thermal distribution of the fish after 48 h was assessed reflecting final thermal preferendum. Additionally, fish were then challenged using a bacterial Streptococcus iniae model infection to assess the behavioural fever response of proactive and reactive fish. Results showed that individuals with preference for higher temperatures were also classified as proactive with behavioural tests and reactive contemporaries chose significantly lower water temperatures. All groups exhibited behavioural fever recovering personality-specific thermal preferences after 5 days. Our results show that thermal preference can be used as a proxy to assess personality traits in Nile tilapia and it is a central factor to understand the adaptive meaning of animal personality within a population. Importantly, response to infection by expressing behavioural fever overrides personality-related thermal choice.
Assuntos
Comportamento de Escolha , Ciclídeos/fisiologia , Personalidade , Animais , Doenças dos Peixes/microbiologia , Distribuição Aleatória , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/veterinária , Streptococcus iniae/fisiologia , TemperaturaRESUMO
Activation of the adenosine 2A receptor (A2AR) reduces inflammation in models of acute injury but contribution in development of chronic abdominal aortic aneurysms (AAAs) is unknown. Elastase perfusion to induce AAA formation in A2AR-knockout (A2ARKO) and C57BL6/J wild-type (WT) mice resulted in nearly 100% larger aneurysms in A2ARKO compared to WT at d 14 (P<0.05), with evidence of greater elastin fragmentation, more immune cell infiltration, and increased matrix metallatoproteinase (MMP) 9 expression (P<0.05). Separately, exogenous A2AR antagonism in elastase-perfused WT mice also resulted in larger aneurysms (P<0.05), while A2AR agonism limited aortic dilatation (P<0.05). Activated Thy-1.2(+) T lymphocytes from WT mice treated in vitro with A2AR antagonist increased cytokine production, and treatment with A2AR agonist decreased cytokine production (P<0.05 for all). Primary activated CD4(+) T lymphocytes from A2ARKO mice exhibited greater chemotaxis (P<0.05). A2AR antagonist increased chemotaxis of activated CD4(+) cells from WT mice in vitro, and A2AR agonist reduced this effect (P<0.05). A2AR activation attenuates AAA formation partly by inhibiting immune cell recruitment and reducing elastin fragmentation. These findings support augmenting A2AR signaling as a putative target for limiting aneurysm formation.
Assuntos
Aneurisma da Aorta Abdominal/metabolismo , Receptores A2 de Adenosina/metabolismo , Adenosina/análogos & derivados , Adenosina/farmacologia , Agonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Animais , Aneurisma da Aorta Abdominal/imunologia , Aneurisma da Aorta Abdominal/patologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Citocinas/metabolismo , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Elastase Pancreática/administração & dosagem , Fenetilaminas/farmacologia , Fenótipo , Receptores A2 de Adenosina/deficiência , Receptores A2 de Adenosina/genética , Triazinas/farmacologia , Triazóis/farmacologiaRESUMO
Scleractinian corals are capable of accumulating polycyclic aromatic hydrocarbons (PAHs) in reef environments; however, the mechanism behind their PAHs tolerance is unknown. This study investigated the occurrence and bioaccumulation of PAHs in coral reef ecosystems and examined the physiological responses induced by PAHs in coral hosts and their algal symbionts, the massive coral Galaxea fascicularis and branching coral Pocillopora damicornis. G. fascicularis had a higher PAHs accumulation capacity than P. damicornis. Both the coral hosts and algal symbionts preferentially accumulated acenaphthene, dibenzo(a,h)anthracene, and benzo(a)pyrene. The accumulated PAHs by G. fascicularis and P. damicornis hosts was accompanied by a reduction in detoxification ability. The accumulated PAHs could induce oxidative stress in P. damicorni hosts, thus G. fascicularis demonstrated a greater tolerance to PAHs compared to P. damicornis. Meanwhile, their algal symbionts had fewer physiological responses to accumulated PAHs than the coral hosts. Negative effects were not observed with benzo(a)pyrene. Taken together, these results suggest massive and branching scleractinian corals have different PAHs bioaccumulation and tolerance mechanisms, and indicate that long-term PAHs pollution could cause significant alterations of community structures in coral reef ecosystems.
Assuntos
Antozoários , Recifes de Corais , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Antozoários/fisiologia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes Químicos da Água/metabolismo , Bioacumulação , Monitoramento Ambiental , SimbioseRESUMO
The presence of dissolved Fe(III) and Fe(III)-containing minerals has been found to alleviate cadmium (Cd) accumulation in wheat plants grown in Cd-contaminated soils, but the specific mechanism remains elusive. In this work, hydroponic experiments were conducted to dissect the mechanism for dissolved Fe(III) (0-2000 µmol L-1) to decrease Cd uptake of wheat plants and study the influence of Fe(III) concentration and Cd(II) pollution level (0-20 µmol L-1) on the Cd uptake process. The results indicated that dissolved Fe(III) significantly decreased Cd uptake through rhizosphere passivation, competitive absorption, and physiological regulation. The formation of poorly crystalline Fe(III) oxides facilitated the adsorption and immobilization of Cd(II) on the rhizoplane (over 80.4 %). In wheat rhizosphere, the content of CaCl2-extractable Cd decreased by 52.7 % when Fe(III) concentration was controlled at 2000 µmol L-1, and the presence of Fe(III) may reduce the formation of Cd(II)-organic acid complexes (including malic acid and succinic acid secreted by wheat roots), which could be attributed to competitive reactions. Down-regulation of Cd uptake genes (TaNramp5-a and TaNramp5-b) and transport genes (TaHMA3-a, TaHMA3-b and TaHMA2), along with up-regulation of the Cd efflux gene TaPDR8-4A7A, contributed much to the reduction of Cd accumulation in wheat plants in the presence of Fe(III). The inhibitory effect of Fe(III) on Cd uptake and transport in wheat plants declined with increasing Cd(II) concentration, particularly at 20 µmol L-1. This work provides important implications for remediating Cd-contaminated farmland soil and ensuring the safe production of wheat by using dissolved Fe(III) and Fe(III)-containing minerals.
Assuntos
Cádmio , Rizosfera , Poluentes do Solo , Triticum , Triticum/metabolismo , Cádmio/metabolismo , Poluentes do Solo/metabolismo , Ferro/metabolismo , Compostos Férricos , Raízes de Plantas/metabolismo , Solo/químicaRESUMO
The fundamental models underlying hormonal physiological regulation and homeostasis remain poorly understood. We aimed to derive quantitative evidence regarding these models from the study of population data of balance points of different parameters and their respective controlling hormones. We studied the slopes of correlations between concentrations of circulating free thyroxine and thyrotropin, calcium and parathyroid hormone, hemoglobin and erythropoietin, and glucose and insulin in such population data, as well as the slopes of the limbs of various feedback loops estimated empirically and by reverse engineering of the population data. We used computer simulations to model the factors that influence the slopes derived from the population data, and then matched these simulations with the empirically derived slopes. Our simulations showed that changes to the population distribution of feedback loop limbs may alter the slopes of correlations within population data in specific ways. Non-random (interdependent) associations of the limbs of feedback loops may also have this effect, as well as producing discrepancies between the slopes of feedback limb loops determined experimentally and the same slopes determined by derivation from population data. Our corresponding empirical findings were consistent with the presence of such interdependence in the free thyroxine/thyrotropin, hemoglobin/erythropoietin, and glucose/insulin systems. The glucose/insulin data provided evidence consistent with increasing interdependence with age in childhood. Our findings therefore provide strong evidence that the interdependence of the limbs of feedback loops is a general feature of endocrine homeostatic regulation. This interdependence potentially bestows evolutionary homeostatic and regulatory advantages.
Assuntos
Glicemia , Retroalimentação Fisiológica , Insulina , Tireotropina , Tiroxina , Humanos , Tiroxina/sangue , Retroalimentação Fisiológica/fisiologia , Tireotropina/sangue , Insulina/sangue , Adulto , Masculino , Feminino , Glicemia/metabolismo , Glicemia/análise , Simulação por Computador , Hormônio Paratireóideo/sangue , Pessoa de Meia-Idade , Criança , Cálcio/sangue , Cálcio/metabolismo , Adolescente , Eritropoetina/sangue , Modelos Biológicos , Hemoglobinas/metabolismo , Hemoglobinas/análise , Idoso , Hormônios/sangue , Homeostase/fisiologia , Adulto JovemRESUMO
BACKGROUND: Callous-unemotional (CU) traits are characterized by low empathy, guilt, and prosociality, putting children at risk for lifespan antisocial behavior. Elevated CU traits have been linked separately to difficulties with emotion understanding (i.e., identifying emotional states of others) and disrupted parasympathetic nervous system (PNS) functioning. However, no study has investigated how PNS functioning and emotion understanding are jointly related to CU traits. METHOD: We explored associations between CU traits, emotion understanding, and PNS functioning (indexed via respiratory sinus arrhythmia [RSA]) among children aged 7-10 years old (n = 55). We also tested whether deficits in emotion understanding differ across specific emotions (i.e., fear, pain, happiness, anger). Each child's RSA was continuously recorded while they watched a film that included emotionally evocative social interactions. To assess emotion understanding, children identified emotions replayed in 1s animations of scenes from the film. Parents reported on child CU traits, conduct problems, and demographic information. RESULTS: Higher CU traits were related to lower emotion understanding (ß = -0.43, p = 0.03). PNS activity during the film moderated this association (ß = -0.47, p < 0.001), such that CU traits were associated with lower emotion understanding among children with mean (B = -0.01, t = -2.46, p = 0.02) or high (i.e., 1 SD > M; B = -0.02, t = -3.00, p < 0.001) RSA levels during the film, but not among children with low RSA levels (i.e., 1 SD < M; B = 0.00, t = -0.53, p = 0.60). Moreover, we found that the observed moderated associations are driven by deficits in fear, specifically. CONCLUSIONS: The link between poorer emotion understanding, fear understanding in particular, and CU traits was attenuated for children who demonstrated patterns of PNS functioning consistent with attentional engagement while viewing the emotion stimuli.
RESUMO
Accumulation and enrichment of excessive heavy metals due to industrialization and modernization not only devastate our ecosystem, but also pose a threat to the global vegetation, especially crops. To improve plant resilience against heavy metal stress (HMS), numerous exogenous substances (ESs) have been tried as the alleviating agents. After a careful and thorough review of over 150 recently published literature, 93 reported ESs and their corresponding effects on alleviating HMS, we propose that 7 underlying mechanisms of ESs be categorized in plants for: 1) improving the capacity of the antioxidant system, 2) inducing the synthesis of osmoregulatory substances, 3) enhancing the photochemical system, 4) detouring the accumulation and migration of heavy metals, 5) regulating the secretion of endogenous hormones, 6) modulating gene expressions, and 7) participating in microbe-involved regulations. Recent research advances strongly indicate that ESs have proven to be effective in mitigating a potential negative impact of HMS on crops and other plants, but not enough to ultimately solve the devastating problem associated with excessive heavy metals. Therefore, much more research should be focused and carried out to eliminate HMS for the sustainable agriculture and clean environmental through minimizing towards prohibiting heavy metals from entering our ecosystem, phytodetoxicating polluted landscapes, retrieving heavy metals from detoxicating plants or crop, breeding for more tolerant cultivars for both high yield and tolerance against HMS, and seeking synergetic effect of multiply ESs on HMS alleviation in our feature researches.
Assuntos
Metais Pesados , Poluentes do Solo , Ecossistema , Poluentes do Solo/análise , Melhoramento Vegetal , Metais Pesados/análise , Produtos Agrícolas/metabolismo , Solo/químicaRESUMO
Bettinger, J. S., K. J. Friston. Conceptual Foundations of Physiological Regulation incorporating the Free Energy Principle & Self-Organized Criticality. NEUROSCI BIOBEHAV REV 23(x) 144-XXX, 2022. Since the late nineteen-nineties, the concept of homeostasis has been contextualized within a broader class of "allostatic" dynamics characterized by a wider-berth of causal factors including social, psychological and environmental entailments; the fundamental nature of integrated brain-body dynamics; plus the role of anticipatory, top-down constraints supplied by intrinsic regulatory models. Many of these evidentiary factors are integral in original descriptions of homeostasis; subsequently integrated; and/or cite more-general operating principles of self-organization. As a result, the concept of allostasis may be generalized to a larger category of variational systems in biology, engineering and physics in terms of advances in complex systems, statistical mechanics and dynamics involving heterogenous (hierarchical/heterarchical, modular) systems like brain-networks and the internal milieu. This paper offers a three-part treatment. 1) interpret "allostasis" to emphasize a variational and relational foundation of physiological stability; 2) adapt the role of allostasis as "stability through change" to include a "return to stability" and 3) reframe the model of homeostasis with a conceptual model of criticality that licenses the upgrade to variational dynamics.