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1.
Nat Commun ; 14(1): 20, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36596764

RESUMO

Miniaturized rotors based on Marangoni effect have attracted great attentions due to their promising applications in propulsion and power generation. Despite intensive studies, the development of Marangoni rotors with high rotation output and fuel economy remains challenging. To address this challenge, we introduce an asymmetric porosity strategy to fabricate Marangoni rotor composed of thermoresponsive hydrogel and low surface tension anesthetic metabolite. Combining enhanced Marangoni propulsion of asymmetric porosity with drag reduction of well-designed profile, our rotor precedes previous studies in rotation output (~15 times) and fuel economy (~34% higher). Utilizing thermoresponsive hydrogel, the rotor realizes rapid refueling within 33 s. Moreover, iron-powder dopant further imparts the rotors with individual-specific locomotion in group under magnetic stimuli. Significantly, diverse functionalities including kinetic energy transmission, mini-generator and environmental remediation are demonstrated, which open new perspectives for designing miniaturized rotating machineries and inspire researchers in robotics, energy, and environment.


Assuntos
Hidrogéis , Porosidade , Fenômenos Físicos , Tempo , Tensão Superficial
2.
Cogn Sci ; 47(1): e13224, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36655934

RESUMO

Previous research on linguistic relativity and economic decisions hypothesized that speakers of languages with obligatory tense marking of future time reference (FTR) should value future rewards less than speakers of languages which permit present tense FTR. This was hypothesized on the basis of obligatory linguistic marking (e.g., will) causing speakers to construe future events as more temporally distal and thereby to exhibit increased "temporal discounting": the subjective devaluation of outcomes as the delay until they will occur increases. However, several aspects of this hypothesis are incomplete. First, it overlooks the role of "modal" FTR structures which encode notions about the likelihood of future outcomes (e.g., might). This may influence "probability discounting": the subjective devaluation of outcomes as the probability of their occurrence decreases. Second, the extent to which linguistic structures are subjectively related to temporal or probability discounting differences is currently unknown. To address these, we elicited FTR language and subjective ratings of temporal distance and probability from speakers of English, which exhibits strongly grammaticized FTR, and Dutch, which does not. Several findings went against the predictions of the previous hypothesis: Framing an FTR statement in the present ("Ellie arrives later on") versus the future tense ("…will arrive…") did not affect ratings of temporal distance; English speakers rated future statements as relatively more temporally proximal than Dutch speakers; and English and Dutch speakers rated future tenses as encoding high certainty, which suggests that obligatory future tense marking might result in less discounting. Additionally, compared with Dutch speakers, English speakers used more low-certainty terms in general (e.g., may) and as a function of various experimental factors. We conclude that the prior cross-linguistic observations of the link between FTR and psychological discounting may be caused by the connection between low-certainty modal structures and probability discounting, rather than future tense and temporality.


Assuntos
Idioma , Linguística , Humanos , Tempo , Probabilidade
3.
Sci Rep ; 13(1): 866, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36650269

RESUMO

Understanding how a disease spreads in a population is a first step to preparing for future epidemics, and machine learning models are a useful tool to analyze the spreading process of infectious diseases. For effective predictions of these spreading processes, node embeddings are used to encode networks based on the similarity between nodes into feature vectors, i.e., higher dimensional representations of human contacts. In this work, we evaluated the impact of homophily and structural equivalence on node2vec embedding for disease spread prediction by testing them on real world temporal human contact networks. Our results show that structural equivalence is a useful indicator for the infection status of a person. Embeddings that are balanced towards the preservation of structural equivalence performed better than those that focus on the preservation of homophily, with an average improvement of 0.1042 in the f1-score (95% CI 0.051 to 0.157). This indicates that structurally equivalent nodes behave similarly during an epidemic (e.g., expected time of a disease onset). This observation could greatly improve predictions of future epidemics where only partial information about contacts is known, thereby helping determine the risk of infection for different groups in the population.


Assuntos
Epidemias , Humanos , Tempo
4.
Sci Rep ; 13(1): 464, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36627356

RESUMO

One of the fundamental goals in neuroscience is to determine how the brain processes information and ultimately controls the execution of complex behaviors. Over the past four decades, there has been a steady growth in our knowledge of the morphological and functional diversity of neurons, the building blocks of the brain. These cells clearly differ not only for their anatomy and ion channel distribution, but also for the type, strength, location, and temporal pattern of activity of the many synaptic inputs they receive. Compartmental modeling programs like NEURON have become widely used in the neuroscience community to address a broad range of research questions, including how neurons integrate synaptic inputs and propagate information through complex neural networks. One of the main strengths of NEURON is its ability to incorporate user-defined information about the realistic morphology and biophysical properties of different cell types. Although the graphical user interface of the program can be used to run initial exploratory simulations, introducing a stochastic representation of synaptic weights, locations and activation times typically requires users to develop their own codes, a task that can be overwhelming for some beginner users. Here we describe NRN-EZ, an interactive application that allows users to specify complex patterns of synaptic input activity that can be integrated as part of NEURON simulations. Through its graphical user interface, NRN-EZ aims to ease the learning curve to run computational models in NEURON, for users that do not necessarily have a computer science background.


Assuntos
Redes Neurais de Computação , Neurônios , Neurônios/fisiologia , Canais Iônicos , Tempo , Modelos Neurológicos , Sinapses/fisiologia
5.
Sci Rep ; 13(1): 952, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36653404

RESUMO

Intensive longitudinal data can be used to explore important associations and patterns between various types of inputs and outcomes. Nonlinear relations and irregular measurement occasions can pose problems to develop an accurate model for these kinds of data. This paper focuses on the development, fitting and evaluation of a prediction model with irregular intensive longitudinal data. A three-step process for developing a prediction tool for (daily) monitoring and prediction is outlined and illustrated for intensive weight measurements in piglets. Step 1 addresses a nonlinear relation in the data by developing and applying a normalizing transformation. Step 2 addresses the intermittent nature of the time points by aligning the measurement times to a common time grid with a broken-stick model. Step 3 addresses the prediction problem by selecting and evaluating inputs and covariates in the model to obtain accurate predictions. The final model predicts future outcomes accurately, while allowing for nonlinearities between input and output and for different measurement histories of individuals. The methodology described can be used to develop a tool to deal with intensive irregular longitudinal data that uses the available information in an optimal way. The resulting tool demonstrated to perform well for piglet weight prediction and can be adapted to many different applications.


Assuntos
Tempo , Suínos , Animais , Previsões
6.
Int J Mol Sci ; 24(2)2023 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-36675200

RESUMO

In Parkinson's disease, hypercholinism in the striatum occurs, with the consequence of disturbed motor functions. Direct application of Botulinum neurotoxin-A in the striatum of hemi-Parkinsonian rats might be a promising anticholinergic therapeutic option. Here, we aimed to determine the spread of intrastriatally injected BoNT-A in the brain as well as the duration of its action based on the distribution of cleaved SNAP-25. Rats were injected with 1 ng of BoNT-A into the right striatum and the brains were examined at different times up to one year after treatment. In brain sections immunohistochemically stained for BoNT-A, cleaved SNAP-25 area-specific densitometric analyses were performed. Increased immunoreactivity for cleaved SNAP-25 was found in brain regions other than the unilaterally injected striatum. Most cleaved SNAP-25-ir was found in widespread areas ipsilateral to the BoNT-A injection, in some regions, however, immunoreactivity was also measured in the contralateral hemisphere. There was a linear relationship between the distance of a special area from the injected striatum and the time until its maximum averaged immunoreactivity was reached. Moreover, we observed a positive relationship for the area-specific distance from the injected striatum and its maximum immunoreactivity as well as for the connection density with the striatum and its maximum immunoreactivity. The results speak for a bidirectional axonal transport of BoNT-A after its application into the striatum to its widespread connected parts of the brain. Even one year after BoNT-A injection, cleaved SNAP-25 could still be detected.


Assuntos
Corpo Estriado , Doença de Parkinson , Ratos , Animais , Neostriado , Injeções , Tempo
7.
Sensors (Basel) ; 23(1)2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36617049

RESUMO

The Chinese Remainder Theorem (CRT) based frequency estimation has been widely studied during the past two decades. It enables one to estimate frequencies by sub-Nyquist sampling rates, which reduces the cost of hardware in a sensor network. Several studies have been done on the complex waveform; however, few works studied its applications in the real waveform case. Different from the complex waveform, existing CRT methods cannot be straightforwardly applied to handle a real waveform's spectrum due to the spurious peaks. To tackle the ambiguity problem, in this paper, we propose the first polynomial-time closed-form Robust CRT (RCRT) for the single-tone real waveform, which can be considered as a special case of RCRT for arbitrary two numbers. The time complexity of the proposed algorithm is O(L), where L is the number of samplers. Furthermore, our algorithm also matches the optimal error-tolerance bound.


Assuntos
Algoritmos , Tempo
8.
Sensors (Basel) ; 23(1)2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36617082

RESUMO

We performed a non-stationary analysis of a class of buffer management schemes for TCP/IP networks, in which the arriving packets were rejected randomly, with probability depending on the queue length. In particular, we derived formulas for the packet waiting time (queuing delay) and the intensity of packet losses as functions of time. These results allow us to observe how the evolution of the waiting time and losses depend on initial conditions (e.g., the full buffer) and system parameters (e.g., dropping probabilities, load, packet size distribution). As side results, the stationary waiting time and packet loss probability were obtained. Numerical examples demonstrate applicability of the theoretical results.


Assuntos
Algoritmos , Software , Tempo , Probabilidade
9.
PLoS One ; 18(1): e0280145, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36608003

RESUMO

Humans are born with very low contrast sensitivity, meaning that inputs to the infant visual system are both blurry and low contrast. Is this solely a byproduct of maturational processes or is there a functional advantage for beginning life with poor visual acuity? We addressed the impact of poor vision during early learning by exploring whether reduced visual acuity facilitated the acquisition of basic-level categories in a convolutional neural network model (CNN), as well as whether any such benefit transferred to subordinate-level category learning. Using the ecoset dataset to simulate basic-level category learning, we manipulated model training curricula along three dimensions: presence of blurred inputs early in training, rate of blur reduction over time, and grayscale versus color inputs. First, a training regime where blur was initially high and was gradually reduced over time-as in human development-improved basic-level categorization performance in a CNN relative to a regime in which non-blurred inputs were used throughout training. Second, when basic-level models were fine-tuned on a task including both basic-level and subordinate-level categories (using the ImageNet dataset), models initially trained with blurred inputs showed a greater performance benefit as compared to models trained exclusively on non-blurred inputs, suggesting that the benefit of blurring generalized from basic-level to subordinate-level categorization. Third, analogous to the low sensitivity to color that infants experience during the first 4-6 months of development, these advantages were observed only when grayscale images were used as inputs. We conclude that poor visual acuity in human newborns may confer functional advantages, including, as demonstrated here, more rapid and accurate acquisition of visual object categories at multiple levels.


Assuntos
Redes Neurais de Computação , Aprendizagem Espacial , Recém-Nascido , Lactente , Humanos , Tempo
10.
BMC Med Res Methodol ; 23(1): 15, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36647014

RESUMO

INTRODUCTION: Surveys are common research tools, and questionnaires revisions are a common occurrence in longitudinal studies. Revisions can, at times, introduce systematic shifts in measures of interest. We formulate that questionnaire revision are a stochastic process with transition matrices. Thus, revision shifts can be reduced by first estimating these transition matrices, which can be utilized in estimation of interested measures. MATERIALS AND METHOD: An ideal survey response model is defined by mapping between the true value of a participant's response to an interval in the grouped data type scale. A population completed surveys multiple times, as modeled with multiple stochastic process. This included stochastic processes related to true values and intervals. While multiple factors contribute to changes in survey responses, here, we explored the method that can mitigate the effects of questionnaire revision. We proposed the Version Alignment Method (VAM), a data preprocessing tool, which can separate the transitions according to revisions from all transitions via solving an optimization problem and using the revision-related transitions to remove the revision effect. To verify VAM, we used simulation data to study the estimation error and a real life MJ dataset containing large amounts of long-term questionnaire responses with several questionnaire revisions to study its feasibility. RESULT: We compared the difference of the annual average between consecutive years. Without adjustment, the difference is 0.593 when the revision occurred, while VAM brought it down to 0.115, where difference between years without revision was in the 0.005, 0.125 range. Furthermore, our method rendered the responses to the same set of intervals, thus comparing the relative frequency of items before and after revisions became possible. The average estimation error in L infinity was 0.0044 which occupied the 95% CI which was constructed by bootstrap analysis. CONCLUSION: Questionnaire revisions can induce different response bias and information loss, thus causing inconsistencies in the estimated measures. Conventional methods can only partly remedy this issue. Our proposal, VAM, can estimate the aggregate difference of all revision-related systematic errors and can reduce the differences, thus reducing inconsistencies in the final estimations of longitudinal studies.


Assuntos
Falha de Prótese , Humanos , Tempo , Inquéritos e Questionários , Reoperação
11.
PLoS One ; 18(1): e0277314, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36649267

RESUMO

In this paper, we separately constructed ARIMA, ARIMAX, and RNN models to determine whether there exists an impact of the air pollutants (such as PM2.5, PM10, CO, O3, NO2, and SO2) on the number of pulmonary tuberculosis cases from January 2014 to December 2018 in Urumqi, Xinjiang. In addition, by using a new comprehensive evaluation index DISO to compare the performance of three models, it was demonstrated that ARIMAX (1,1,2) × (0,1,1)12 + PM2.5 (lag = 12) model was the optimal one, which was applied to predict the number of pulmonary tuberculosis cases in Urumqi from January 2019 to December 2019. The predicting results were in good agreement with the actual pulmonary tuberculosis cases and shown that pulmonary tuberculosis cases obviously declined, which indicated that the policies of environmental protection and universal health checkups in Urumqi have been very effective in recent years.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Tuberculose Pulmonar , Humanos , Poluentes Atmosféricos/análise , Tuberculose Pulmonar/epidemiologia , Tempo , Material Particulado/análise , Poluição do Ar/análise , China/epidemiologia
12.
Structure ; 31(1): 4-19, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36584678

RESUMO

Molecular machines, such as polymerases, ribosomes, or proteasomes, fulfill complex tasks requiring the thermal energy of their environment. They achieve this by restricting random motion along a path of possible conformational changes. These changes are often directed through engagement with different cofactors, which can best be compared to a Brownian ratchet. Many molecular machines undergo three major steps throughout their functional cycles, including initialization, repetitive processing, and termination. Several of these major states have been elucidated by cryogenic electron microscopy (cryo-EM). However, the individual steps for these machines are unique and multistep processes themselves, and their coordination in time is still elusive. To measure these short-lived intermediate events by cryo-EM, the total reaction time needs to be shortened to enrich for the respective pre-equilibrium states. This approach is termed time-resolved cryo-EM (trEM). In this review, we sum up the methodological development of trEM and its application to a range of biological questions.


Assuntos
Simulação de Dinâmica Molecular , Ribossomos , Microscopia Crioeletrônica , Movimento (Física) , Tempo
13.
J Chromatogr A ; 1689: 463726, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36586281

RESUMO

In proteomics, the need to precisely examine the protein compounds of small samples, requires sensitive analytical methods which can separate and enrich compounds with high precision. Current techniques require a minimal analysis time to obtain satisfactory compound separation where longer analysis time means better separation of compounds. But, molecular diffusion will create broadening of the separated compound bands over time, increasing the peak width, and thus reducing the resolution and the enrichment. Electric field gradient focusing (EFGF) is a separation technique, in which proteins are simultaneously separated and enriched by balancing a gradient electrostatic force with a constant hydrodynamic drag force. Because of this balance, analytes are continuously pushed back to their focusing point, limiting the time-dependent peak broadening due to molecular diffusion. Current EFGF techniques are however still suffering from peak broadening because of flow-profile inhomogeneities. In this paper, we propose to use AC electro-osmotic flow (AC EOF) to create a homogeneous flow in EFGF. The interference between the electric field gradient and the AC EOF was thoroughly analysed and the concept was validated using numerical simulations. The results show that a plug flow is obtained on top of a small, distorted boundary layer. While applying different DC electric fields in the electrolyte, a constant flow velocity can be obtained by including a DC offset to the electrodes generating the AC EOF. The plug flow is then maintained over the whole separation channel length, while an electric field gradient is applied. This way, the flow-induced contribution to peak broadening can be minimized in EFGF devices. By modelling the separation of green fluorescent protein (GFP) and R-Phycoerythrin (R-PE), it was shown that the peak width of separated compounds can be reduced and that the separation resolution can be improved, compared to current EFGF methods.


Assuntos
Eletricidade , Proteínas de Fluorescência Verde , Tempo
14.
Rev. neurol. (Ed. impr.) ; 75(12): 383-385, Dic 12, 2022. ilus
Artigo em Espanhol | IBECS | ID: ibc-213692

RESUMO

La cronotaraxis es una afectación de la percepción de la secuencia temporal. Esta alteración de la temporalidad se ha descrito asociada de forma característica a la afectación talámica, concretamente al núcleo dorsomediano. Casos clínicos. Presentamos los casos clínicos de dos pacientes con ictus isquémicos agudos de localización en dicho territorio, con una clínica basada en este síntoma y cuyo reconocimiento resultó esencial en el abordaje terapéutico. Tanto en el primero como en el segundo caso se describe cómo la percepción de la temporalidad fue esencial para el diagnóstico de la patología isquémica de ambos pacientes. Discusión. El conocimiento y la divulgación de esta asociación pueden resultar fundamentales en el manejo de los pacientes con alteraciones talámicas. Esto se debe a la posibilidad que surge de influir y modificar el abordaje inicial, puesto que el reconocimiento de un síntoma específico, como es la cronotaraxis, puede evitar la extensión del daño talámico, y prevenir de esta manera las secuelas, sobre todo cognitivas, que ocasiona a largo plazo.(AU)


Introduction: Chronotaraxis is an impairment of the perception of the sequencing of time. This alteration of temporality has been described as being characteristically associated with thalamic involvement, specifically in the dorsomedial nucleus. Case reports: We report the clinical cases of two patients with acute ischaemic strokes located in said territory, with a clinical presentation based on this symptom and the recognition of which was essential in the therapeutic approach. In the first and second cases, it is described how the perception of temporality was essential for the diagnosis of the ischaemic condition in both patients. Discussion: Awareness and dissemination of this association may be vital in the management of patients with thalamic disorders. This is due to the possibility of influencing and modifying the initial approach, since the recognition of a specific symptom, such as chronotaraxis, can prevent the spread of thalamic damage, in addition to the long-term sequelae that it causes, especially those of a cognitive nature.(AU)


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Acidente Vascular Cerebral , Tálamo , Tempo , Atenção , Espectroscopia de Ressonância Magnética , Neurologia , Doenças do Sistema Nervoso
15.
Sci Rep ; 12(1): 22416, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36575232

RESUMO

Many parts of our social lives are speeding up, a process known as social acceleration. How social acceleration impacts people's ability to judge the veracity of online news, and ultimately the spread of misinformation, is largely unknown. We examined the effects of accelerated online dynamics, operationalised as time pressure, on online misinformation evaluation. Participants judged the veracity of true and false news headlines with or without time pressure. We used signal detection theory to disentangle the effects of time pressure on discrimination ability and response bias, as well as on four key determinants of misinformation susceptibility: analytical thinking, ideological congruency, motivated reflection, and familiarity. Time pressure reduced participants' ability to accurately distinguish true from false news (discrimination ability) but did not alter their tendency to classify an item as true or false (response bias). Key drivers of misinformation susceptibility, such as ideological congruency and familiarity, remained influential under time pressure. Our results highlight the dangers of social acceleration online: People are less able to accurately judge the veracity of news online, while prominent drivers of misinformation susceptibility remain present. Interventions aimed at increasing deliberation may thus be fruitful avenues to combat online misinformation.


Assuntos
Comunicação , Mídias Sociais , Humanos , Reconhecimento Psicológico , Tempo
16.
Medicina (Kaunas) ; 58(12)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36557045

RESUMO

Background and Objectives: Previous studies have suggested that long-term ß-blocker therapy before sepsis is associated with reduced mortality. Sepsis-associated coagulopathy (SAC) remains a common complication in patients with sepsis and is associated with increased mortality. Adrenergic pathways are involved in the regulation of the coagulation system. Pre-existing long-term ß-blocker therapy may have potentially beneficial effects on SAC and has yet to be well characterized. We aimed to assess the potential association between pre-existing long-term ß-blocker therapy and the outcomes of patients with SAC. Materials and Methods: This study retrospectively screened the clinical data of adult patients with SAC admitted to the Intensive Care Unit (ICU) and respiratory ICU between May 2020 and October 2022. Patients with SAC who took any ß-blocker for at least one year were considered pre-existing long-term ß-blocker therapy. All enrolled patients were followed up for 28 days or until death. Results: Among the 228 SAC patients, 48 received long-term ß-blocker therapy before septic episodes. Pre-existing long-term ß-blocker therapy was associated with reduced vasopressor requirements and a decreased 28-day mortality (log-rank test: p = 0.041). In particular, long-term ß-blocker therapy was related to substantially lower D-dimer levels and a trend of improved activated partial thromboplastin time in patients with SAC during initial ICU admission. Multivariable regression analysis showed that long-term ß-blocker therapy was significantly and independently associated with a 28-day mortality among patients with SAC (adjusted odds ratio, 0.55; 95% confidence interval, (0.32-0.94); p = 0.030). Conclusions: Pre-existing long-term ß-blocker therapy might be associated with reduced vasopressor requirements and a decreased 28-day mortality among patients with SAC, providing evidence for the protective effect of ß-blockers against SAC in managing sepsis.


Assuntos
Transtornos da Coagulação Sanguínea , Sepse , Adulto , Humanos , Estudos Retrospectivos , Sepse/complicações , Sepse/tratamento farmacológico , Transtornos da Coagulação Sanguínea/complicações , Transtornos da Coagulação Sanguínea/tratamento farmacológico , Tempo , Mortalidade Hospitalar , Antagonistas Adrenérgicos beta/uso terapêutico , Unidades de Terapia Intensiva
17.
PeerJ ; 10: e14486, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36536628

RESUMO

Background: While it is well known that illnesses such as cancer modify the experience of time, the impact of the rhythm and length of treatment on patients' time perspectives remains unknown. Methods: A short version of Zimbardo Time Perspective Inventory and Transcendental Future Perspective Questionnaire as well as a demographic questionnaire on a convenience sample of 259 patients (66.8% female, mean age 52.36) with various cancers and undergoing chemotherapy with different frequencies (1, 2, 3 weeks) and mean time in treatment 23.4 months. Results: The temporal perspectives mean scores of cancer patients are: positive past 3.69, negative past 3.13, present hedonism 3.08, future 3.77, transcendental future 3.40. Patients tend only slightly to lose faith alongside the course of oncological treatment regardless of their age (ρ =  - 0.210, p < 0.01). The frequency of chemotherapy mildly differentiates temporal perspectives of patients regarding present hedonism and transcendental future: a weekly treatment is more disturbing than the triweekly one and no treatment in terms of hedonism, while patients not in chemo score significantly higher in transcendental future than patients in biweekly and triweekly chemo. Conclusions: The variations of treatment rhythm are less significant than predicted, although still relevant. Since most sociodemographic variables are of no relevance, cancer experience likely unifies temporal perspectives among people of different backgrounds.


Assuntos
Neoplasias , Percepção do Tempo , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Tempo , Nível de Saúde , Previsões
18.
Sensors (Basel) ; 22(24)2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36560301

RESUMO

We develop a probabilistic model for determining the location of dc-link faults in MT-HVdc networks using discrete wavelet transforms (DWTs), Bayesian optimization, and multilayer artificial neural networks (ANNs) based on local information. Likewise, feedforward neural networks (FFNNs) are trained using the Levenberg-Marquardt backpropagation (LMBP) method, which multi-stage BO optimizes for efficiency. During training, the feature vectors at the sending terminal of the dc link are selected based on the norm values of the observed waveforms at various frequency bands. The multilayer ANN is trained using a comprehensive set of offline data that takes the denoising scheme into account. This choice not only helps to reduce the computational load but also provides better accuracy. An overall percentage error of 0.5144% is observed for the proposed algorithm when tested against fault resistances ranging from 10 to 485 Ω. The simulation results show that the proposed method can accurately estimate the fault site to a precision of 485 Ω and is more robust.


Assuntos
Algoritmos , Redes Neurais de Computação , Teorema de Bayes , Simulação por Computador , Tempo
19.
Sci Rep ; 12(1): 21894, 2022 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-36536054

RESUMO

Understanding climate variability and stability under extremely warm 'greenhouse' conditions in the past is essential for future climate predictions. However, information on millennial-scale (and shorter) climate variability during such periods is scarce, owing to a lack of suitable high-resolution, deep-time archives. Here we present a continuous record of decadal- to orbital-scale continental climate variability from annually laminated lacustrine deposits formed during the late Early Cretaceous (123-120 Ma: late Barremian-early Aptian) in southeastern Mongolia. Inter-annual changes in lake algal productivity for a 1091-year interval reveal a pronounced solar influence on decadal- to centennial-scale climatic variations (including the ~ 11-year Schwabe cycle). Decadally-resolved Ca/Ti ratios (proxy for evaporation/precipitation changes) for a ~ 355-kyr long interval further indicate millennial-scale (~ 1000-2000-yr) extreme drought events in inner-continental areas of mid-latitude palaeo-Asia during the Cretaceous. Millennial-scale oscillations in Ca/Ti ratio show distinct amplitude modulation (AM) induced by the precession, obliquity and short eccentricity cycles. Similar millennial-scale AM by Milankovitch cycle band was also previously observed in the abrupt climatic oscillations (known as Dansgaard-Oeschger events) in the 'intermediate glacial' state of the late Pleistocene, and in their potential analogues in the Jurassic 'greenhouse'. Our findings indicate that external solar activity forcing was effective on decadal-centennial timescales, whilst the millennial-scale variations were likely amplified by internal process such as changes in deep-water formation strength, even during the Cretaceous 'greenhouse' period.


Assuntos
Sedimentos Geológicos , Água , Tempo , Ásia , Plantas
20.
Artigo em Inglês | MEDLINE | ID: mdl-36360925

RESUMO

The many facets of work, including employment relationships and attendant employment quality, the day-to-day conditions experienced in any given job, and the evolution of one's working circumstances over time can support or detract from health, and combine in myriad ways to impact worker well-being [...].


Assuntos
Equidade em Saúde , Humanos , Emprego , Estudos Longitudinais , Tempo
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