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1.
Mol Med Rep ; 23(5)2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33760141

RESUMO

Isocitrate dehydrogenase1 (IDH1) mutation is the most important genetic change in glioma. The most common IDH1 mutation results in the amino acid substitution of arginine 132 (Arg/R132), which is located at the active site of the enzyme. IDH1 Arg132His (R132H) mutation can reduce the proliferative rate of glioma cells. Numerous diseases follow circadian rhythms, and there is growing evidence that circadian disruption may be a risk factor for cancer in humans. Dysregulation of the circadian clock serves an important role in the development of malignant tumors, including glioma. Brain­Muscle Arnt­Like protein 1 (BMAL1) and Circadian Locomotor Output Cycles Kaput (CLOCK) are the main biological rhythm genes. The present study aimed to further study whether there is an association between IDH1 R132H mutation and biological rhythm in glioma, and whether this affects the occurrence of glioma. The Cancer Genome Atlas (TCGA) database was used to detect the expression levels of the biological rhythm genes BMAL1 and CLOCK in various types of tumor. Additionally, U87­MG cells were infected with wild­type and mutant IDH1 lentiviruses. Colony formation experiments were used to detect cell proliferation in each group, cell cycle distribution was detected by flow cytometry and western blotting was used to detect the expression levels of wild­type and mutant IDH1, cyclins, biological rhythm genes and Smad signaling pathway­associated genes in U87­MG cells. TCGA database results suggested that BMAL1 and CLOCK were abnormally expressed in glioma. Cells were successfully infected with wild­type and mutant IDH1 lentiviruses. Colony formation assay revealed decreased cell proliferation in the IDH1 R132H mutant group. The cell cycle distribution detected by flow cytometry indicated that IDH1 gene mutation increased the G1 phase ratio and decreased the S phase ratio in U87­MG cells. The western blotting results demonstrated that IDH1 R132H mutation decreased the expression levels of the S phase­associated proteins Cyclin A and CDK2, and increased the expression levels of the G1 phase­associated proteins Cyclin D3 and CDK4, but did not significantly change the expression levels of the G2/M phase­associated protein Cyclin B1. The expression levels of the positive and negative rhythm regulation genes BMAL1, CLOCK, period (PER s (PER1, 2 and 3) and cryptochrom (CRY)s (CRY1 and 2) were significantly decreased, those of the Smad signaling pathway­associated genes Smad2, Smad3 and Smad2­3 were decreased, and those of phosphorylated (p)­Smad2, p­Smad3 and Smad4 were increased. Therefore, the present results suggested that the IDH1 R132H mutation may alter the cell cycle and biological rhythm genes in U87­MG cells through the TGF­ß/Smad signaling pathway.


Assuntos
Proteínas de Ciclo Celular/genética , Proliferação de Células/genética , Glioma/genética , Isocitrato Desidrogenase/genética , Ciclo Celular , Proteínas de Ciclo Celular/classificação , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Glioma/patologia , Humanos , Mutação/genética , Periodicidade , Proteínas Smad/genética
2.
Medicine (Baltimore) ; 100(13): e25298, 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33787619

RESUMO

ABSTRACT: This study was aimed at assessing the impact of the dusk phenomenon on the total glucose exposure in Chinese people with type 2 diabetes.A total of 380 type 2 diabetes who received a retrospective continuous glucose monitoring system (CGMs) for 72 hours were enrolled in our study, 32 of them failed in CGMs. The patients were first divided into 2 groups: dusk phenomenon (n = 95) and non dusk phenomenon group (n = 253). The magnitude of the dusk phenomenon (δDusk) was quantified by pre-dinner glucose minus post-lunch 2 hours glucose. A persistent δDusk ≥ 0 or a once only δDusk < 0 can be diagnosed with the dusk phenomenon. The participants were secondarily matched for the post-lunch 2 hours glucose to assess the impact of the dusk phenomenon on the overall glucose exposure. The impact of the dusk phenomenon was assessed on high-performance liquid chromatography assay (HbA1c) and 24-hour mean glucose.There were 95 of 348 (27.3%) participants with the dusk phenomenon in the overall population, and the median of δDusk level was -0.8 (-1.8, 0.2) mmol/L. The median of glucose differences between the 2 paired groups were 0.4 (-0.4, 1.0)% for HbA1c, 0.9 (0.2, 1.4) mmol/L for 24 hours mean glucose. The correlation analysis showed no relationship between the magnitude of dawn phenomenon and the dusk phenomenon (r = 0.052, P = .472).The incidence of dusk phenomenon is about 27.3% in people with type 2 diabetes. The impacts of dusk phenomenon on HbA1c and 24-hour mean glucose were about 0.4% and 0.9 mmol/L and the dusk phenomenon was not related with the dawn phenomenon.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Hemoglobina A Glicada/metabolismo , Hiperglicemia/sangue , Refeições/fisiologia , Idoso , Automonitorização da Glicemia , Fenômenos Fisiológicos Sanguíneos , China , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Hiperglicemia/etiologia , Masculino , Pessoa de Meia-Idade , Periodicidade
3.
Planta ; 253(3): 75, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33629150

RESUMO

MAIN CONCLUSION: Plants exposed to equivalent ozone fluxes administered during day-time versus night-time exhibited greater losses in biomass at night and this finding is attributed to night-time depletion of cell wall-localised ascorbate. The present study employed Lactuca sativa and its closest wild relative, L. serriola, to explore the relative sensitivity of plants to ozone-induced oxidative stress during day-time versus night-time. By controlling atmospheric ozone concentration and measuring stomatal conductance, equivalent ozone uptake into leaves was engineered during day and night, and consequences on productivity and net CO2 assimilation rate were determined. Biomass losses attributable to ozone were significantly greater when an equivalent dose of ozone was taken-up by foliage at night compared to the day. Linkages between ozone impacts and ascorbic acid (AA) content, redox status and cellular compartmentation were probed in both species. Leaf AA pools were depleted by exposure of plants to darkness, and then AA levels in the apoplast and symplast were monitored on subsequent transfer of plants to the light. Apoplast AA appeared to be more affected by light-dark transition than the symplast pool. Moreover, equivalent ozone fluxes administered to leaves with contrasting AA levels resulted in contrasting effects on the light-saturated rate of CO2 assimilation (Asat) in both species. Once apoplast AA content recovered to pre-treatment levels, the same ozone flux resulted in no impacts on Asat. The results of the present investigation reveal that plants are significantly more sensitive to equivalent ozone fluxes taken-up at night compared with those during the day and were consistent with diel shifts in apoplast AA content and/or redox status. Furthermore, findings suggest that some thought should be given to weighing regional models of ozone impacts for extraordinary night-time ozone impacts.


Assuntos
Alface/fisiologia , Ozônio , Periodicidade , Folhas de Planta/fisiologia , Ácido Ascórbico/análise , Transporte Biológico , Oxirredução , Ozônio/toxicidade
4.
Biol Lett ; 17(2): 20200673, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33563135

RESUMO

How ecosystem biodiversity is maintained remains a persistent question in the field of ecology. Here, I present a new coexistence theory, i.e. diversity of biological rhythm. Circadian, circalunar and circannual rhythms, which control short- and long-term activities, are identified as universal phenomena in organisms. Analysis of a theoretical food web with diel, monthly and annual cycles in foraging activity for each organism shows that diverse biological cycles play key roles in maintaining complex communities. Each biological rhythm does not have a strong stabilizing effect independently but enhances community persistence when combined with other rhythms. Biological rhythms also mitigate inherent destabilization tendencies caused by food web complexity. Temporal weak interactions due to hybridity of multiple activity cycles play a key role toward coexistence. Polyrhythmic changes in biological activities in response to the Earth's rotation may be a key factor in maintaining biological communities.


Assuntos
Ecossistema , Cadeia Alimentar , Biodiversidade , Ritmo Circadiano , Ecologia , Modelos Biológicos , Periodicidade
5.
J Dairy Sci ; 104(5): 5794-5804, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33516553

RESUMO

Fertility is of primary economic importance in dairy cattle and the most common reason for involuntary culling. However, standard fertility traits have very low heritability that renders genetic selection slow and difficult. In this study, we explored fertility from an endocrine standpoint. A total of 1,163 crossbred Holstein-Normande females in a 3-generation familial design were studied for progesterone level measured every 10 d to determine age at puberty (PUB) and commencement of postpartum luteal activity (CPLA). Genetic parameters were estimated using REML with WOMBAT software. The heritability estimates were 0.38 ± 0.10 and 0.16 ± 0.07 for PUB and CPLA, respectively. Moreover, the 2 traits were genetically correlated (0.45 ± 0.23), suggesting a partially common determinism. Because of the family structure, a linkage disequilibrium and linkage analysis approach was preferred over standard genome-wide association study to map genomic regions associated with these traits. Ten quantitative trait loci (QTL) were detected for PUB on chromosomes 1, 3, 11, 13, 14, 21, and 29, whereas 3 QTL were associated with CPLA on chromosomes 21 and 26. Only the QTL on chromosome 21 was common to both traits. Four functional candidate genes (NCOA2, GAS2, OVOL1, and FOSL1) were identified in the detected regions. These findings will contribute to a clearer understanding of fertility determinism and enhance the value of introducing endocrinological data in fertility studies.


Assuntos
Estudo de Associação Genômica Ampla , Progesterona , Animais , Bovinos/genética , Feminino , Fertilidade/genética , Estudo de Associação Genômica Ampla/veterinária , Periodicidade , Maturidade Sexual/genética
6.
Nat Metab ; 3(1): 43-58, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33432202

RESUMO

The mammalian liver is a central hub for systemic metabolic homeostasis. Liver tissue is spatially structured, with hepatocytes operating in repeating lobules, and sub-lobule zones performing distinct functions. The liver is also subject to extensive temporal regulation, orchestrated by the interplay of the circadian clock, systemic signals and feeding rhythms. However, liver zonation has previously been analysed as a static phenomenon, and liver chronobiology has been analysed at tissue-level resolution. Here, we use single-cell RNA-seq to investigate the interplay between gene regulation in space and time. Using mixed-effect models of messenger RNA expression and smFISH validations, we find that many genes in the liver are both zonated and rhythmic, and most of them show multiplicative space-time effects. Such dually regulated genes cover not only key hepatic functions such as lipid, carbohydrate and amino acid metabolism, but also previously unassociated processes involving protein chaperones. Our data also suggest that rhythmic and localized expression of Wnt targets could be explained by rhythmically expressed Wnt ligands from non-parenchymal cells near the central vein. Core circadian clock genes are expressed in a non-zonated manner, indicating that the liver clock is robust to zonation. Together, our scRNA-seq analysis reveals how liver function is compartmentalized spatio-temporally at the sub-lobular scale.


Assuntos
Relógios Circadianos/genética , Expressão Gênica/fisiologia , Fígado/metabolismo , Periodicidade , Algoritmos , Aminoácidos/metabolismo , Animais , Metabolismo dos Carboidratos/genética , Perfilação da Expressão Gênica , Hepatócitos/metabolismo , Metabolismo dos Lipídeos/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Chaperonas Moleculares/metabolismo , Proteínas Circadianas Period/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Via de Sinalização Wnt/genética
7.
Clin EEG Neurosci ; 52(1): 61-65, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33334178

RESUMO

INTRODUCTION: Lateralized rhythmic delta activity (LRDA) is a rare pattern on the ictal-interictal continuum (IIC) encountered in critically ill patients. Its association with acute seizures is yet to be fully explored. Insular involvement is a common finding in patients with infectious and autoimmune encephalitis. The association between acute insular lesions and the ictal-interictal continuum, particularly LRDA, has not been explored before. METHODS: A case series of 4 patients with either herpetic or autoimmune encephalitis and prominent insular cortex involvement who had LRDA when monitored on continuous EEG is being presented. RESULTS: Two patients had herpetic encephalitis and 2 patients had autoimmune encephalitis. All patients had either clinical or electrographic seizures with 1 patient progressing into new-onset refractory status epilepticus. CONCLUSION: LRDA can be seen in patients with insular cortex acute inflammation. In this group of patients, LRDA may be associated with a higher risk of acute seizures. The presence of this otherwise not clearly epileptiform pattern should raise the clinical suspicion for the development of acute seizures. Patients with LRDA and ipsilateral insular lesions should be carefully monitored for the development of recurrent electrographic or electroclinical seizures and status epilepticus.


Assuntos
Ritmo Delta/fisiologia , Encefalite/imunologia , Doença de Hashimoto/imunologia , Convulsões/fisiopatologia , Estado Epiléptico/fisiopatologia , Idoso , Ritmo Delta/imunologia , Eletroencefalografia/métodos , Encefalite/fisiopatologia , Feminino , Doença de Hashimoto/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Periodicidade , Convulsões/imunologia , Estado Epiléptico/imunologia
8.
J Oral Rehabil ; 48(4): 392-402, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33368502

RESUMO

BACKGROUND: Closing movements are among the jaw's basic physiological motor actions. During functional movements, the jaw changes position continually, which requires appropriate proprioception. However, the significance of the various proprioceptive receptors involved and how they interact is not yet fully clear. OBJECTIVES: This study's main objective was to test whether preventing intercuspation (IC) for 1 week would affect the precision of jaw-closing movements into IC and the functional space of habitual chewing movements (HCM). A secondary objective was to compare precision of jaw-closing movements into IC with the precision of movements into a target position (TP) far from IC. METHODS: Fourteen participants' HCM and jaw-closing movements into IC were recorded on two sessions (T1 and T2) 1 week apart. Between sessions, participants wore posterior bite plates to prevent IC. They also received a 10-minute training session at T1 to guide their jaw-closing movements into TP. The precision of the closing movements into IC and TP was analysed. For HCM, the vertical amplitude, lateral width and area of chewing cycles were evaluated. RESULTS: The precision of jaw movements into IC increased as the jaw gap decreased, but precision did not differ significantly between T1 and T2. For HCM, the vertical amplitude and area of chewing cycles increased significantly between T1 and T2. The precision of the closing trajectory into TP increased significantly during the training session. CONCLUSION: Our results confirm the excellent adaptability of the craniomandibular system, controlled by stringent motor programmes that are supported by continuous peripheral sensory input.


Assuntos
Mastigação , Movimento , Humanos , Arcada Osseodentária , Periodicidade
9.
J Stroke Cerebrovasc Dis ; 30(3): 105544, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33341022

RESUMO

AIM: This study aims to analyze the effects of rhythm of music therapy on gait in patients with ischemic stroke, and explore the value of music therapy in walking training in stroke. METHODS: The present study is a prospective clinical study. Sixty patients with ischemic stroke, who were admitted to our hospital from October 2017 to December 2018, were enrolled. These patients were divided into two groups, according to the method of the random number table, with thirty patients in each group: control group and study group. Patients in the control group received conventional drug therapy, rehabilitation training and walking training, while the patients in the study group were given music therapy on the basis of the above mentioned therapies for four weeks, during which Sunday was regarded as a rest day, and the music therapy was suspended. The main outcome measures included indexes in evaluating the walking ability of patients in these two groups. At each time point, the Fugl-Meyer Assessment (FMA), Berg Balance Scale (BBS) and stroke rehabilitation treatment satisfaction questionnaire were used. RESULTS: The results revealed that the stride length, cadence and maximum velocity were higher in patients in the study group, when compared to patients in the control group, at the second week and end of the therapy, and the difference in step length between the affected side and healthy side was significantly lower in the study group than in the control group. These differences were statistically significant (P < 0.05). In the second week of therapy and at the end of therapy, the FMA and BBS scores were higher in the study group than in the control group, and the difference was statistically significant (P < 0.05). The total satisfaction rate was higher in the study group than in the control group, and the difference was statistically significant (P < 0.05). CONCLUSION: Under the stimulation of music rhythm, applying music therapy to patients with ischemic stroke can improve their gait, walking ability, lower limb motor function, balance ability and treatment satisfaction.


Assuntos
Marcha , Musicoterapia , Música , Periodicidade , Reabilitação do Acidente Vascular Cerebral , Idoso , Estudos de Casos e Controles , Feminino , Humanos , /fisiopatologia , Masculino , Pessoa de Meia-Idade , Atividade Motora , Satisfação do Paciente , Equilíbrio Postural , Estudos Prospectivos , Distribuição Aleatória , Recuperação de Função Fisiológica , Fatores de Tempo , Resultado do Tratamento
10.
Lancet Neurol ; 20(2): 127-135, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33341149

RESUMO

BACKGROUND: People with epilepsy are burdened with the apparent unpredictability of seizures. In the past decade, converging evidence from studies using chronic EEG (cEEG) revealed that epileptic brain activity shows robust cycles, operating over hours (circadian) and days (multidien). We hypothesised that these cycles can be leveraged to estimate future seizure probability, and we tested the feasibility of forecasting seizures days in advance. METHODS: We did a feasibility study in distinct development and validation cohorts, involving retrospective analysis of cEEG data recorded with an implanted device in adults (age ≥18 years) with drug-resistant focal epilepsy followed at 35 centres across the USA between Jan 19, 2004, and May 18, 2018. Patients were required to have had 20 or more electrographic seizures (development cohort) or self-reported seizures (validation cohort). In all patients, the device recorded interictal epileptiform activity (IEA; ≥6 months of continuous hourly data), the fluctuations in which helped estimate varying seizure risk. Point process statistical models trained on initial portions of each patient's cEEG data (both cohorts) generated forecasts of seizure probability that were tested on subsequent unseen seizure data and evaluated against surrogate time-series. The primary outcome was the percentage of patients with forecasts showing improvement over chance (IoC). FINDINGS: We screened 72 and 256 patients, and included 18 and 157 patients in the development and validation cohorts, respectively. Models incorporating information about multidien IEA cycles alone generated daily seizure forecasts for the next calendar day with IoC in 15 (83%) patients in the development cohort and 103 (66%) patients in the validation cohort. The forecasting horizon could be extended up to 3 days while maintaining IoC in two (11%) of 18 patients and 61 (39%) of 157 patients. Forecasts with a shorter horizon of 1 h, possible only for electrographic seizures in the development cohort, showed IoC in all 18 (100%) patients. INTERPRETATION: This study shows that seizure probability can be forecasted days in advance by leveraging multidien IEA cycles recorded with an implanted device. This study will serve as a basis for prospective clinical trials to establish how people with epilepsy might benefit from seizure forecasting over long horizons. FUNDING: None. VIDEO ABSTRACT.


Assuntos
Epilepsias Parciais/diagnóstico , Convulsões/diagnóstico , Adulto , Eletroencefalografia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Periodicidade , Valor Preditivo dos Testes , Probabilidade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Autorrelato , Resultado do Tratamento
11.
PLoS Biol ; 18(12): e3000506, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33347440

RESUMO

Smallpox is unique among infectious diseases in the degree to which it devastated human populations, its long history of control interventions, and the fact that it has been successfully eradicated. Mortality from smallpox in London, England was carefully documented, weekly, for nearly 300 years, providing a rare and valuable source for the study of ecology and evolution of infectious disease. We describe and analyze smallpox mortality in London from 1664 to 1930. We digitized the weekly records published in the London Bills of Mortality (LBoM) and the Registrar General's Weekly Returns (RGWRs). We annotated the resulting time series with a sequence of historical events that might have influenced smallpox dynamics in London. We present a spectral analysis that reveals how periodicities in reported smallpox mortality changed over decades and centuries; many of these changes in epidemic patterns are correlated with changes in control interventions and public health policies. We also examine how the seasonality of reported smallpox mortality changed from the 17th to 20th centuries in London.


Assuntos
Varíola/epidemiologia , Varíola/mortalidade , Surtos de Doenças , Inglaterra/epidemiologia , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , Humanos , Londres/epidemiologia , Periodicidade , Varíola/história
12.
BMC Bioinformatics ; 21(1): 485, 2020 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-33121431

RESUMO

BACKGROUND: Even though several computational methods for rhythmicity detection and analysis of biological data have been proposed in recent years, classical trigonometric regression based on cosinor still has several advantages over these methods and is still widely used. Different software packages for cosinor-based rhythmometry exist, but lack certain functionalities and require data in different, non-unified input formats. RESULTS: We present CosinorPy, a Python implementation of cosinor-based methods for rhythmicity detection and analysis. CosinorPy merges and extends the functionalities of existing cosinor packages. It supports the analysis of rhythmic data using single- or multi-component cosinor models, automatic selection of the best model, population-mean cosinor regression, and differential rhythmicity assessment. Moreover, it implements functions that can be used in a design of experiments, a synthetic data generator, and import and export of data in different formats. CONCLUSION: CosinorPy is an easy-to-use Python package for straightforward detection and analysis of rhythmicity requiring minimal statistical knowledge, and produces publication-ready figures. Its code, examples, and documentation are available to download from https://github.com/mmoskon/CosinorPy . CosinorPy can be installed manually or by using pip, the package manager for Python packages. The implementation reported in this paper corresponds to the software release v1.1.


Assuntos
Periodicidade , Linguagens de Programação , Software , Automação , Humanos
13.
Nature ; 586(7827): 31-32, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32939081
14.
Am J Physiol Heart Circ Physiol ; 319(4): H893-H905, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32886003

RESUMO

Heart rate variability (HRV) is a measure of variation in time interval between heartbeats and reflects the influence of autonomic nervous system and circulating/locally released factors on sinoatrial node discharge. Here, we tested whether electrocardiograms (ECGs) obtained in conscious, restrained mice, a condition that affects sympathovagal balance, reveal alterations of heart rhythm dynamics with aging. Moreover, based on emergence of sodium channels as modulators of pacemaker activity, we addressed consequences of altered sodium channels on heart rhythm. C57Bl/6 mice and mice with enhanced late sodium current due to Nav1.5 mutation at Ser571 (S571E) at ~4 to ~24 mo of age, were studied. HRV was assessed using time- and frequency-domain and nonlinear parameters. For C57Bl/6 and S571E mice, standard deviation of RR intervals (SDRR), total power of RR interval variation, and nonlinear standard deviation 2 (SD2) were maximal at ~4 mo and decreased at ~18 and ~24 mo, together with attenuation of indexes of sympathovagal balance. Modulation of sympathetic and/or parasympathetic divisions revealed attenuation of autonomic tone at ~24 mo. At ~4 mo, S571E mice presented lower heart rate and higher SDRR, total power, and SD2 with respect to C57Bl/6, properties reversed by late sodium current inhibition. At ~24 mo, heart rate decreased in C57Bl/6 but increased in S571E, a condition preserved after autonomic blockade. Collectively, our data indicate that aging is associated with reduced HRV. Moreover, sodium channel function conditions heart rate and its age-related adaptations, but does not interfere with HRV decline occurring with age.NEW & NOTEWORTHY We have investigated age-associated alterations of heart rate properties in mice using conscious electrocardiographic recordings. Our findings support the notion that aging is coupled with altered sympathovagal balance with consequences on heart rate variability. Moreover, by using a genetically engineered mouse line, we provide evidence that sodium channels modulate heart rate and its age-related adaptations.


Assuntos
Envelhecimento , Frequência Cardíaca , Coração/inervação , Periodicidade , Sistema Nervoso Simpático/fisiologia , Nervo Vago/fisiologia , Fatores Etários , Animais , Relógios Biológicos , Estado de Consciência , Eletrocardiografia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Mutação , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo , Restrição Física , Nó Sinoatrial/inervação , Nó Sinoatrial/metabolismo , Fatores de Tempo
15.
PLoS One ; 15(9): e0238949, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925925

RESUMO

Divergence in ecological niche offers organisms the opportunity of exploiting different food and habitat resources, scaling down competition and predation both among species, and within different age or size-classes of the same species. In harsh environments, where abiotic factors determine a clustering of resources during short timespans, competition and predation between organisms is likely to be enhanced. This is the case in tropical dry forests, where amphibians have limited opportunities to feed, their activity being restricted to the short rainy season. One way to maximize resource exploitation while avoiding predation risk is by adopting different diel activity patterns. We tested this hypothesis by comparing activity patterns in adults and recently metamorphosed juveniles of Pacific horned frogs (Ceratophrys stolzmanni) during field surveys and in an experimental study. Field surveys showed that the adults are strictly nocturnal, whereas freshly metamorphosed juveniles can be found active above ground at all hours, with a peak activity during daytime. The average body condition index of juveniles found active during the night was higher than that of juveniles found active during the day, suggesting that the weaker individuals may be constrained to being active during the day. On the other hand, in a laboratory experiment, juveniles that were visually exposed to adults moved less than those in the absence of adults. Both field and experimental observations indicate a temporal niche divergence between life stages. The results of the experiment offer support to the hypothesis that the juveniles in this species display an inverse activity pattern compared to adults, which can reduce competitive interactions and predation pressure from the larger conspecifics.


Assuntos
Ciclos de Atividade/fisiologia , Fatores Etários , Anuros/metabolismo , Anfíbios/metabolismo , Animais , Comportamento Competitivo , Ecossistema , Comportamento Alimentar , Florestas , Periodicidade , Comportamento Predatório , Estações do Ano
16.
PLoS One ; 15(9): e0239033, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925966

RESUMO

Mood and behaviour are thought to be under considerable influence of the seasons, but evidence is not unequivocal. The purpose of this study was to investigate whether mood and affect are related to the seasons, and what is the role of neuroticism in this association. In a national internet-based crowdsourcing project in the Dutch general population, individuals were invited to assess themselves on several domains of mental health. ANCOVA was used to test for differences between the seasons in mean scores on the Positive and Negative Affect Schedule (PANAS) and Quick Inventory of Depressive Symptomatology (QIDS). Within-subject seasonal differences were tested as well, in a subgroup that completed the PANAS twice. The role of neuroticism as a potential moderator of seasonality was examined. Participants (n = 5,282) scored significantly higher on positive affect (PANAS) and lower on depressive symptoms (QIDS) in spring compared to summer, autumn and winter. They also scored significantly lower on negative affect in spring compared to autumn. Effect sizes were small or very small. Neuroticism moderated the effect of the seasons, with only participants higher on neuroticism showing seasonality. There was no within-subject seasonal effect for participants who completed the questionnaires twice (n = 503), nor was neuroticism a significant moderator of this within-subjects effect. The findings of this study in a general population sample participating in an online crowdsourcing study do not support the widespread belief that seasons influence mood to a great extent. For, as far as the seasons did influence mood, this only applied to highly neurotic participants and not to low-neurotic participants. The underlying mechanism of cognitive attribution may explain the perceived relation between seasonality and neuroticism.


Assuntos
Afeto/fisiologia , Periodicidade , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Saúde Mental/tendências , Pessoa de Meia-Idade , Neuroticismo/fisiologia , Estações do Ano , Inquéritos e Questionários
17.
Rev. bras. ativ. fís. saúde ; 25: 1-10, set. 2020. tab, fig
Artigo em Inglês | LILACS | ID: biblio-1141478

RESUMO

This study aims to describe objectively measured physical activity (PA) in different periods of the day in young adults according to sex, socioeconomic position and during weekdays and weekends. This is a cross-sectional analysis carried out with the participants of the 1993 Pelotas Birth Cohort at 22 years. PA was assessed by triaxial accelerometer. Descriptive analyses were performed presenting the time spent on light PA (LPA) and bouted moderate to vigorous PA (MVPA) in different periods of the day (morning - 6am to 11:59 am, afternoon ­ 12pm to 7:59 pm and night ­ 8pm to 11:59pm). The present study included 2,766 individuals (48.2% male and 51.8% female). LPA was higher among women, while bouted MVPA levels were higher among men. The median of PA was higher on weekdays compared to weekends for all intensities. The bouted MVPA medians in the morning and at night were zero minutes for all days and both sexes. The richest group presented a higher percentage of individuals with zero minutes. PA may vary according to different periods of the day and intensity. The absence of PA practice was markedly influenced by sex and socioeconomic position


Este estudo teve o objetivo de mensurar atividade física (AF) objetivamente em diferentes períodos do dia em adultos jovens de acordo com sexo, posição socioeconômica e dia de semana e final de semana. Esta é uma análise transversal conduzida com participantes da Coorte de Nascimentos de 1993 de Pelotas aos 22 anos. AF foi avaliada por um acelerômetro triaxial. Foram realizadas análises descritivas apresentando o tempo em AF leve (AFL) e moderada a vigorosa (AFMV ) em diferentes períodos do dia (manhã ­ 6h às 11:59h, tarde ­ 12h às 19:59h e noite ­ 20h às 0h). O presente estudo incluiu 2.766 individuos (48.2% homens e 51.8% mulheres). AFL foi maior entre as mulheres enquanto AFMV foi maior entre os homens. A mediana de AF foi maior nos dias de semana comparado aos dias de final de semana para qualquer intensidade. As medianas de AFMV pela manhã e noite foram zero minutos para todos os dias nos dois sexos. O grupo econômico mais alto apresentou maior percentual de individuos com zero minutos de AFMV. AF pode variar de acordo com diferentes períodos do dia e intensidades. A ausência de prática de AF foi marcadamente influenciada por sexo e posição socioeconômica


Assuntos
Periodicidade , Acelerometria , Atividade Motora
18.
Epidemiol Psychiatr Sci ; 29: e163, 2020 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-32829741

RESUMO

AIMS: We aimed to investigate the heterogeneity of seasonal suicide patterns among multiple geographically, demographically and socioeconomically diverse populations. METHODS: Weekly time-series data of suicide counts for 354 communities in 12 countries during 1986-2016 were analysed. Two-stage analysis was performed. In the first stage, a generalised linear model, including cyclic splines, was used to estimate seasonal patterns of suicide for each community. In the second stage, the community-specific seasonal patterns were combined for each country using meta-regression. In addition, the community-specific seasonal patterns were regressed onto community-level socioeconomic, demographic and environmental indicators using meta-regression. RESULTS: We observed seasonal patterns in suicide, with the counts peaking in spring and declining to a trough in winter in most of the countries. However, the shape of seasonal patterns varied among countries from bimodal to unimodal seasonality. The amplitude of seasonal patterns (i.e. the peak/trough relative risk) also varied from 1.47 (95% confidence interval [CI]: 1.33-1.62) to 1.05 (95% CI: 1.01-1.1) among 12 countries. The subgroup difference in the seasonal pattern also varied over countries. In some countries, larger amplitude was shown for females and for the elderly population (≥65 years of age) than for males and for younger people, respectively. The subperiod difference also varied; some countries showed increasing seasonality while others showed a decrease or little change. Finally, the amplitude was larger for communities with colder climates, higher proportions of elderly people and lower unemployment rates (p-values < 0.05). CONCLUSIONS: Despite the common features of a spring peak and a winter trough, seasonal suicide patterns were largely heterogeneous in shape, amplitude, subgroup differences and temporal changes among different populations, as influenced by climate, demographic and socioeconomic conditions. Our findings may help elucidate the underlying mechanisms of seasonal suicide patterns and aid in improving the design of population-specific suicide prevention programmes based on these patterns.


Assuntos
Estações do Ano , Suicídio/estatística & dados numéricos , Temperatura Baixa , Feminino , Temperatura Alta , Humanos , Masculino , Periodicidade , Distribuição por Sexo , Fatores Socioeconômicos , Suicídio/psicologia
19.
Am J Physiol Heart Circ Physiol ; 319(2): H507-H518, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32706268

RESUMO

The lymphatic system drains and propels lymph by extrinsic and intrinsic mechanisms. Intrinsic propulsion depends upon spontaneous rhythmic contractions of lymphatic muscles in the vessel walls and is critically affected by changes in the surrounding tissue like osmolarity and temperature. Lymphatics of the diaphragm display a steep change in contraction frequency in response to changes in temperature, and this, in turn, affects lymph flow. In the present work, we demonstrated in an ex vivo diaphragmatic tissue rat model that diaphragmatic lymphatics express transient receptor potential channels of the vanilloid 4 subfamily (TRPV4) and that their blockade by both the nonselective antagonist Ruthenium Red and the selective antagonist HC-067047 abolished the response of lymphatics to temperature changes. Moreover, the selective activation of TRPV4 channels by means of GSK1016790A mirrored the behavior of vessels exposed to increasing temperatures, pointing out the critical role played by these channels in sensing the temperature of the lymphatic vessels' environment and thus inducing a change in contraction frequency and lymph flow.NEW & NOTEWORTHY The present work addresses the putative receptor system that enables diaphragmatic lymphatics to change intrinsic contraction frequency and thus lymph flow according to the changes in temperature of the surrounding environment, showing that this role can be sustained by TRPV4 channels alone.


Assuntos
Linfa/fisiologia , Vasos Linfáticos/metabolismo , Contração Muscular , Músculo Liso/metabolismo , Canais de Cátion TRPV/metabolismo , Temperatura , Animais , Diafragma , Feminino , Técnicas In Vitro , Vasos Linfáticos/efeitos dos fármacos , Masculino , Morfolinas/farmacologia , Músculo Liso/efeitos dos fármacos , Periodicidade , Pirróis/farmacologia , Ratos , Ratos Wistar , Rutênio Vermelho/farmacologia , Transdução de Sinais , Canais de Cátion TRPV/antagonistas & inibidores , Canais de Cátion TRPV/genética , Fatores de Tempo
20.
Nat Commun ; 11(1): 3454, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32651383

RESUMO

Biological rhythms are a fundamental property of life. The deep ocean covers 66% of our planet surface and is one of the largest biomes. The deep sea has long been considered as an arrhythmic environment because sunlight is totally absent below 1,000 m depth. In the present study, we have sequenced the temporal transcriptomes of a deep-sea species, the ecosystem-structuring vent mussel Bathymodiolus azoricus. We reveal that tidal cycles predominate in the transcriptome and physiology of mussels fixed directly at hydrothermal vents at 1,688 m depth at the Mid-Atlantic Ridge, whereas daily cycles prevail in mussels sampled after laboratory acclimation. We identify B. azoricus canonical circadian clock genes, and show that oscillations observed in deep-sea mussels could be either a direct response to environmental stimulus, or be driven endogenously by one or more biological clocks. This work generates in situ insights into temporal organisation in a deep-sea organism.


Assuntos
Mytilidae/fisiologia , Animais , Ecossistema , Fontes Hidrotermais , Biologia Marinha , Periodicidade
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