Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 536
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 120(20): e2300758120, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37155871

RESUMO

In 1967, scientists used a simple climate model to predict that human-caused increases in atmospheric CO2 should warm Earth's troposphere and cool the stratosphere. This important signature of anthropogenic climate change has been documented in weather balloon and satellite temperature measurements extending from near-surface to the lower stratosphere. Stratospheric cooling has also been confirmed in the mid to upper stratosphere, a layer extending from roughly 25 to 50 km above the Earth's surface (S25 - 50). To date, however, S25 - 50 temperatures have not been used in pattern-based attribution studies of anthropogenic climate change. Here, we perform such a "fingerprint" study with satellite-derived patterns of temperature change that extend from the lower troposphere to the upper stratosphere. Including S25 - 50 information increases signal-to-noise ratios by a factor of five, markedly enhancing fingerprint detectability. Key features of this global-scale human fingerprint include stratospheric cooling and tropospheric warming at all latitudes, with stratospheric cooling amplifying with height. In contrast, the dominant modes of internal variability in S25 - 50 have smaller-scale temperature changes and lack uniform sign. These pronounced spatial differences between S25 - 50 signal and noise patterns are accompanied by large cooling of S25 - 50 (1 to 2[Formula: see text]C over 1986 to 2022) and low S25 - 50 noise levels. Our results explain why extending "vertical fingerprinting" to the mid to upper stratosphere yields incontrovertible evidence of human effects on the thermal structure of Earth's atmosphere.

2.
Cereb Cortex ; 34(5)2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38700440

RESUMO

While the auditory and visual systems each provide distinct information to our brain, they also work together to process and prioritize input to address ever-changing conditions. Previous studies highlighted the trade-off between auditory change detection and visual selective attention; however, the relationship between them is still unclear. Here, we recorded electroencephalography signals from 106 healthy adults in three experiments. Our findings revealed a positive correlation at the population level between the amplitudes of event-related potential indices associated with auditory change detection (mismatch negativity) and visual selective attention (posterior contralateral N2) when elicited in separate tasks. This correlation persisted even when participants performed a visual task while disregarding simultaneous auditory stimuli. Interestingly, as visual attention demand increased, participants whose posterior contralateral N2 amplitude increased the most exhibited the largest reduction in mismatch negativity, suggesting a within-subject trade-off between the two processes. Taken together, our results suggest an intimate relationship and potential shared mechanism between auditory change detection and visual selective attention. We liken this to a total capacity limit that varies between individuals, which could drive correlated individual differences in auditory change detection and visual selective attention, and also within-subject competition between the two, with task-based modulation of visual attention causing within-participant decrease in auditory change detection sensitivity.


Assuntos
Atenção , Percepção Auditiva , Eletroencefalografia , Percepção Visual , Humanos , Atenção/fisiologia , Masculino , Feminino , Adulto Jovem , Adulto , Percepção Auditiva/fisiologia , Percepção Visual/fisiologia , Estimulação Acústica/métodos , Estimulação Luminosa/métodos , Potenciais Evocados/fisiologia , Encéfalo/fisiologia , Adolescente
3.
Proc Natl Acad Sci U S A ; 119(44): e2209933119, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36279450

RESUMO

Circadian clocks are synchronized by external timing cues to align with one another and the environment. Various signaling pathways have been shown to independently reset the phase of the clock. However, in the body, circadian clocks are exposed to a multitude of potential timing cues with complex temporal dynamics, raising the question of how clocks integrate information in response to multiple signals. To investigate different modes of signal integration by the circadian clock, we used Circa-SCOPE, a method we recently developed for high-throughput phase resetting analysis. We found that simultaneous exposure to different combinations of known pharmacological resetting agents elicits a diverse range of responses. Often, the response was nonadditive and could not be readily predicted by the response to the individual signals. For instance, we observed that dexamethasone is dominant over other tested inputs. In the case of signals administered sequentially, the background levels of a signal attenuated subsequent resetting by the same signal, but not by signals acting through a different pathway. This led us to examine whether the circadian clock is sensitive to relative rather than absolute levels of the signal. Importantly, our analysis revealed the involvement of a signal-specific fold-change detection mechanism in the clock response. This mechanism likely stems from properties of the signaling pathway that are upstream to the clock. Overall, our findings elucidate modes of input integration by the circadian clock, with potential relevance to clock resetting under both physiological and pathological conditions.


Assuntos
Relógios Circadianos , Relógios Circadianos/fisiologia , Ritmo Circadiano/fisiologia , Transdução de Sinais , Sinais (Psicologia) , Dexametasona/farmacologia
4.
Glob Chang Biol ; 30(2): e17185, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38361266

RESUMO

Climate change in northern latitudes is increasing the vulnerability of peatlands and the riparian transition zones between peatlands and upland forests (referred to as ecotones) to greater frequency of wildland fires. We examined early post-fire vegetation regeneration following the 2011 Utikuma complex fire (central Alberta, Canada). This study examined 779 peatlands and adjacent ecotones, covering an area of ~182 km2 . Based on the known regional fire history, peatlands that burned in 2011 were stratified into either long return interval (LRI) fire regimes of >80 years (i.e., no recorded prior fire history) or short fire return interval (SRI) of 55 years (i.e., within the boundary of a documented severe fire in 1956). Data from six multitemporal airborne lidar surveys were used to quantify trajectories of vegetation change for 8 years prior to and 8 years following the 2011 fire. To date, no studies have quantified the impacts of post-fire regeneration following short versus long return interval fires across this broad range of peatlands with variable environmental and post-fire successional trajectories. We found that SRI peatlands demonstrated more rapid vascular and shrub growth rates, especially in peatland centers, than LRI peatlands. Bogs and fens burned in 1956, and with little vascular vegetation (classified as "open peatlands") prior to the 2011 fire, experienced the greatest changes. These peatlands tended to transition to vascular/shrub forms following the SRI fire, while open LRI peatlands were not significantly different from pre-fire conditions. The results of this study suggest the emergence of a positive feedback, where areas experiencing SRI fires in southern boreal peatlands are expected to transition to forested vegetation forms. Along fen edges and within bog centers, SRI fires are expected to reduce local peatland groundwater moisture-holding capacity and promote favorable conditions for increased fire frequency and severity in the future.


Assuntos
Incêndios , Incêndios Florestais , Florestas , Áreas Alagadas , Alberta , Ecossistema
5.
Psychol Sci ; 35(5): 504-516, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38564652

RESUMO

Motion silencing is a striking and unexplained visual illusion wherein changes that are otherwise salient become difficult to perceive when the changing elements also move. We develop a new method for quantifying illusion strength (Experiments 1a and 1b), and we demonstrate a privileged role for rotational motion on illusion strength compared with highly controlled stimuli that lack rotation (Experiments 2a to 3b). These contrasts make it difficult to explain the illusion in terms of lower-level detection limits. Instead, we explain the illusion as a failure to attribute changes to locations. Rotation exacerbates the illusion because its perception relies upon structured object representations. This aggravates the difficulty of attributing changes by demanding that locations are referenced relative to both an object-internal frame and an external frame. Two final experiments (4a and 4b) add support to this account by employing a synchronously rotating external frame of reference that diminishes otherwise strong motion silencing. All participants were Johns Hopkins University undergraduates.


Assuntos
Percepção de Movimento , Humanos , Percepção de Movimento/fisiologia , Adulto , Feminino , Masculino , Adulto Jovem , Ilusões Ópticas/fisiologia , Rotação
6.
Sensors (Basel) ; 24(5)2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38475044

RESUMO

Remote sensing images change detection technology has become a popular tool for monitoring the change type, area, and distribution of land cover, including cultivated land, forest land, photovoltaic, roads, and buildings. However, traditional methods which rely on pre-annotation and on-site verification are time-consuming and challenging to meet timeliness requirements. With the emergence of artificial intelligence, this paper proposes an automatic change detection model and a crowdsourcing collaborative framework. The framework uses human-in-the-loop technology and an active learning approach to transform the manual interpretation method into a human-machine collaborative intelligent interpretation method. This low-cost and high-efficiency framework aims to solve the problem of weak model generalization caused by the lack of annotated data in change detection. The proposed framework can effectively incorporate expert domain knowledge and reduce the cost of data annotation while improving model performance. To ensure data quality, a crowdsourcing quality control model is constructed to evaluate the annotation qualification of the annotators and check their annotation results. Furthermore, a prototype of automatic detection and crowdsourcing collaborative annotation management platform is developed, which integrates annotation, crowdsourcing quality control, and change detection applications. The proposed framework and platform can help natural resource departments monitor land cover changes efficiently and effectively.

7.
Sensors (Basel) ; 24(4)2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38400425

RESUMO

To address the challenges of handling imprecise building boundary information and reducing false-positive outcomes during the process of detecting building changes in remote sensing images, this paper proposes a Siamese transformer architecture based on a difference module. This method introduces a layered transformer to provide global context modeling capability and multiscale features to better process building boundary information, and a difference module is used to better obtain the difference features of a building before and after a change. The difference features before and after the change are then fused, and the fused difference features are used to generate a change map, which reduces the false-positive problem to a certain extent. Experiments were conducted on two publicly available building change detection datasets, LEVIR-CD and WHU-CD. The F1 scores for LEVIR-CD and WHU-CD reached 89.58% and 84.51%, respectively. The experimental results demonstrate that when utilized for building change detection in remote sensing images, the proposed method exhibits improved robustness and detection performance. Additionally, this method serves as a valuable technical reference for the identification of building damage in remote sensing images.

8.
Sensors (Basel) ; 24(11)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38894286

RESUMO

Research on transformers in remote sensing (RS), which started to increase after 2021, is facing the problem of a relative lack of review. To understand the trends of transformers in RS, we undertook a quantitative analysis of the major research on transformers over the past two years by dividing the application of transformers into eight domains: land use/land cover (LULC) classification, segmentation, fusion, change detection, object detection, object recognition, registration, and others. Quantitative results show that transformers achieve a higher accuracy in LULC classification and fusion, with more stable performance in segmentation and object detection. Combining the analysis results on LULC classification and segmentation, we have found that transformers need more parameters than convolutional neural networks (CNNs). Additionally, further research is also needed regarding inference speed to improve transformers' performance. It was determined that the most common application scenes for transformers in our database are urban, farmland, and water bodies. We also found that transformers are employed in the natural sciences such as agriculture and environmental protection rather than the humanities or economics. Finally, this work summarizes the analysis results of transformers in remote sensing obtained during the research process and provides a perspective on future directions of development.

9.
Sensors (Basel) ; 24(7)2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38610483

RESUMO

Relative radiometric normalization (RRN) is a critical pre-processing step that enables accurate comparisons of multitemporal remote-sensing (RS) images through unsupervised change detection. Although existing RRN methods generally have promising results in most cases, their effectiveness depends on specific conditions, especially in scenarios with land cover/land use (LULC) in image pairs in different locations. These methods often overlook these complexities, potentially introducing biases to RRN results, mainly because of the use of spatially aligned pseudo-invariant features (PIFs) for modeling. To address this, we introduce a location-independent RRN (LIRRN) method in this study that can automatically identify non-spatially matched PIFs based on brightness characteristics. Additionally, as a fast and coregistration-free model, LIRRN complements keypoint-based RRN for more accurate results in applications where coregistration is crucial. The LIRRN process starts with segmenting reference and subject images into dark, gray, and bright zones using the multi-Otsu threshold technique. PIFs are then efficiently extracted from each zone using nearest-distance-based image content matching without any spatial constraints. These PIFs construct a linear model during subject-image calibration on a band-by-band basis. The performance evaluation involved tests on five registered/unregistered bitemporal satellite images, comparing results from three conventional methods: histogram matching (HM), blockwise KAZE, and keypoint-based RRN algorithms. Experimental results consistently demonstrated LIRRN's superior performance, particularly in handling unregistered datasets. LIRRN also exhibited faster execution times than blockwise KAZE and keypoint-based approaches while yielding results comparable to those of HM in estimating normalization coefficients. Combining LIRRN and keypoint-based RRN models resulted in even more accurate and reliable results, albeit with a slight lengthening of the computational time. To investigate and further develop LIRRN, its code, and some sample datasets are available at link in Data Availability Statement.

10.
Environ Monit Assess ; 196(4): 383, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38502244

RESUMO

Land use and land cover are critical factors that influence the environment and human societies. The dynamics of LULC have been constantly changing over the years, and these changes can be analyzed at different spatial and temporal scales to evaluate their impact on the natural environment. This study employs multitemporal satellite data to investigate the spatial and temporal transformations that occurred in Sidi Bel Abbes province, situated in the northwestern region of Algeria, spanning from the early 1990s to 2020. Notably, this province is marked by semi-arid and arid climates and hosts a wide range of areas susceptible to gravitational hazards, especially concerning alterations in land use and forest fires. The interactive supervised classification tool utilized multiple machine learning algorithms including Random Forest, Support Vector Machine, Classification and Regression Tree, and Naïve Bayes to produce land cover maps with six main classes: forest, shrub, agricultural, pasture, water, and built-up. The findings showed that the LULC in the research area is undergoing continuous change, particularly in the forest and agricultural lands. The forest area has decreased significantly from 10.80% in 1990 to 5.25% in 2020, mainly due to repeated fires. Agricultural land has also undergone fluctuations, with a decrease between 1990 and 2000, followed by a fast increase and near stabilization in 2020. At the same time, pasture lands and built-up areas grew steadily, increasing by 11% and 13% respectively. This research highlights the significant impact of anthropogenic activities on LULC changes in the study area and can provide valuable insights for promoting sustainable land use policies.


Assuntos
Efeitos Antropogênicos , Monitoramento Ambiental , Humanos , Argélia , Teorema de Bayes , Clima Desértico , Conservação dos Recursos Naturais
11.
Environ Monit Assess ; 196(3): 233, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38311668

RESUMO

Remote sensing is one of the most important methods for analysing the multitemporal changes over a certain period. As a cost-effective way, remote sensing allows the long-term analysis of agricultural land by collecting satellite imagery from different satellite missions. Landsat is one of the longest-running world missions which offers a moderate-resolution earth observation dataset. Land surface mapping and monitoring are generally performed by incorporating classification and change detection models. In this work, a deep learning-based change detection (DCD) algorithm has been proposed to detect long-term agricultural changes using the Landsat series datasets (i.e., Landsat-7, Landsat-8, and Landsat-9) during the period 2012 to 2023. The proposed algorithm extracts the features from satellite data according to their spectral and geographic characteristics and identifies seasonal variability. The DCD integrates the deep learning-based (Environment for visualizing images) ENVI Net-5 classification model and posterior probability-based post-classification comparison-based change detection model (PCD). The DCD is capable of providing seasonal variations accurately with distinct Landsat series dataset and promises to use higher resolution dataset with accurate results. The experimental result concludes that vegetation has decreased from 2012 to 2023, while build-up land has increased up to 88.22% (2012-2023) for Landsat-7 and Landsat-8 datasets. On the other side, degraded area includes water (3.20-0.05%) and fallow land (1-0.59%). This study allows the identification of crop growth, crop yield prediction, precision farming, and crop mapping.


Assuntos
Aprendizado Profundo , Monitoramento Ambiental/métodos , Imagens de Satélites , Agricultura , Estações do Ano
12.
Environ Monit Assess ; 196(3): 250, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38340236

RESUMO

The Madaba Governorate, as the second-largest wheat producer in Jordan, holds a crucial position in safeguarding regional food security. Its evolving landscape, marked by changes in land use, presents environmental and socio-economic challenges that necessitate sustainable urban planning and land management practices. This study delves into the intricate relationship between the conversion of agricultural lands into urban areas and the concurrent rise in population within the Madaba Governorate. Utilizing a Markov model, this research employs land use and land cover (LULC) data from 1994, 2004, and 2015 to project future changes in 2025 and 2035 with an impressive 80% accuracy (kappa coefficient). The findings reveal a projected 6% increase in urban areas over the next decade and a notable 11.81% decline in rural lands, signifying a substantial urbanization trend. In response to these population-driven LULC dynamics, there is an urgent need for the implementation of sustainable land use planning and management solutions. Given the constraints of limited water resources in the region, this study also places emphasis on water resource management. Recommendations include measures such as restricting urban sprawl, preserving agricultural lands, managing population growth, and implementing water conservation strategies. These insights provide invaluable information for stakeholders in the Madaba Governorate, including policymakers and land use planners, fostering a comprehensive understanding of the complex interplay between regional water resources, population expansion, and land use changes.


Assuntos
Conservação dos Recursos Naturais , Crescimento Demográfico , Jordânia , Monitoramento Ambiental , Urbanização , Agricultura
13.
Environ Monit Assess ; 196(2): 182, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38252360

RESUMO

A key source of information for many decision support systems is identifying land use and land cover (LULC) based on remote sensing data. Land conservation, sustainable development, and water resource management all benefit from the knowledge obtained from detecting changes in land use and land cover. The present study aims to investigate the multi-decadal coastal change detection for Ras El-Hekma and El-Dabaa area along the Mediterranean coast of Egypt, a multi-sectoral development area. Besides, the superiority of the area is highly dependent on its proximity to three development projects: the tourism and urban growth pole at Ras El-Hekma, the beachfront Alamain New Mega City, and the Nuclear Power Plant at El Dabaa. This study utilized multi-spectral Landsat satellite images covering 1990, 2010, and 2020 to perceive the post-classification change detection analysis of the land use and land cover changes (LULCC) over 30 years. The results of the supervised classification from 1990 to 2020 showed a 47.33 km2 (4.13%) expansion of the agricultural land area, whereas the bare soil land area shrunk to 73.13 km2 (6.24%). On the other hand, the built-up activities in the area launched in 2010 and escalated to 20.51 km2(1.77%) in 2020. The change in land use reveals the shift in the economic growth pattern in the last decade toward tourism and urban development. Meanwhile, it indicates that no conflict has yet arisen regarding the land use between the expanded socioeconomic main sectors (i.e., agriculture, and tourism). Therefore, the best practices of land use management and active participation of the stakeholders and the local community should be enhanced to achieve sustainability and avoid future conflicts. An area-specific plan including resource conservation measures and the provision of livelihood alternatives should be formulated within the National Integrated Coastal Zone Management (ICZM) plan with the participation of the main stakeholders and beneficiaries. The findings of the present work may be considered useful for sustainable management and supportive to the decision-making process for the sustainable development of this area.


Assuntos
Monitoramento Ambiental , Tecnologia de Sensoriamento Remoto , Egito , Agricultura , Ciclo Celular
14.
Psychol Sci ; 34(1): 111-119, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36322970

RESUMO

We typically think of intuitive physics in terms of high-level cognition, but might aspects of physics also be extracted during lower-level visual processing? Might we not only think about physics, but also see it? We explored this using multiple tasks in online adult samples with objects covered by soft materials-as when you see a chair with a blanket draped over it-where you must account for the physical interactions between cloth, gravity, and object. In multiple change-detection experiments (n = 200), observers from an online testing marketplace were better at detecting image changes involving underlying object structure versus those involving only the superficial folds of cloths-even when the latter were more extreme along several dimensions. And in probe-comparison experiments (n = 100), performance was worse when both probes (vs. only one) appeared on image regions reflective of underlying object structure (equating visual properties). This work collectively shows how vision uses intuitive physics to recover the deeper underlying structure of scenes.


Assuntos
Cognição , Percepção Visual , Adulto , Humanos , Atenção , Física
15.
Psychol Sci ; 34(10): 1087-1100, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37650877

RESUMO

Visual working memory (VWM) is limited in capacity, though memorizing meaningful objects may refine this limitation. However, meaningful and meaningless stimuli typically differ perceptually, and objects' associations with meaning are usually already established outside the laboratory, potentially confounding experimental findings. Here, in two experiments with young adults (N = 45 and N = 20), we controlled for these influences by having observers actively learn associations of (for them) initially meaningless stimuli: Chinese characters, half of which were consistently paired with pictures of animals or everyday objects in a learning phase. This phase was preceded and followed by a (pre- and postlearning) change-detection task to assess VWM performance. The results revealed that short-term retention was enhanced after learning, particularly for meaning-associated characters, although participants did not quite reach the accuracy level attained by native Chinese observers (young adults, N = 20). These results thus provide direct experimental evidence that participants' VWM of objects is boosted by them having acquired a long-term-memory association with meaning.

16.
Psychol Sci ; 34(3): 370-383, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36608146

RESUMO

Visual short-term memory (STM) is a foundational component of general cognition that develops rapidly during the first year of life. Although previous research has revealed important relations between overt visual fixation and memory formation, it is unknown whether infants can maintain distinct memories for sequentially fixated items or remember nonfixated array items. Participants (5-month-olds, 11-month-olds, and adults; n = 24 at each age) from the United States were tested in a passive change-detection paradigm with an n-back manipulation to examine memory for the last fixated item (one-back), second-to-last fixated item (two-back), or nonfixated item (change-other). Eye tracking was used to measure overt fixation while participants passively viewed arrays of colored circles. Results for all ages revealed convergent evidence of memory for up to two sequentially fixated objects (i.e., one-back, two-back), with moderate evidence for nonfixated array items (change-other). A permutation analysis examining change preference over time suggested that differences could not be explained by perseverative looking or location biases.


Assuntos
Cognição , Memória de Curto Prazo , Humanos , Adulto , Lactente , Fixação Ocular , Rememoração Mental , Percepção Visual
17.
Cereb Cortex ; 32(23): 5467-5477, 2022 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-35149872

RESUMO

Neuronal repetition effect (repetition suppression and repetition enhancement) and change detection responses are fundamental brain responses that have implications in learning and cognitive development in infants and children. Studies have shown altered neuronal repetition and change detection responses in various clinical populations. However, the developmental course of these neuronal responses from infancy through childhood is still unknown. Using an electroencephalography oddball task, we investigate the developmental peculiarities of repetition effect and change detection responses in 43 children that we followed longitudinally from 3 months to 4 years of age. Analyses were conducted on theta (3-5 Hz), alpha (5-10 Hz), and beta (10-30 Hz) time-frequency windows. Results indicated that in the theta time-frequency window, in frontocentral and frontal regions of the brain, repetition and change detection responses followed a U-shaped pattern from 3 months to 4 years of age. Moreover, the change detection response was stronger in young infants compared to older children in frontocentral regions, regardless of the time-frequency window. Our findings add to the evidence of top-down modulation of perceptual systems in infants and children.


Assuntos
Encéfalo , Eletroencefalografia , Lactente , Humanos , Criança , Adolescente , Estudos Longitudinais , Eletroencefalografia/métodos , Encéfalo/fisiologia , Aprendizagem/fisiologia , Neurônios/fisiologia
18.
Environ Res ; 222: 115379, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36716805

RESUMO

Understanding terrestrial ecosystem dynamics requires a comprehensive examination of vegetation changes. Remote sensing technology has been established as an effective approach to reconstructing vegetation change history, investigating change properties, and evaluating the ecological effects. However, current remote sensing techniques are primarily focused on break detection but ignore long-term trend analysis. In this study, we proposed a novel framework based on a change detection algorithm and a trend analysis method that could integrate both short-term disturbance detection and long-term trends to comprehensively assess vegetation change. With this framework, we characterized the vegetation changes in Zhejiang Province from 1990 to 2020 using Landsat and landcover data. Benefiting from combining break detection and long-term trend analysis, the framework showcased its capability of capturing a variety of dynamics and trends of vegetation. The results show that the vegetation was browning in the plains while greening in the mountains, and the overall vegetation was gradually greening during the study period. By comparison, detected vegetation disturbances covered 57.71% of the province's land areas (accounting for 66.92% of the vegetated region) which were mainly distributed around the built-up areas, and most disturbances (94%) occurred in forest and cropland. There were two peak timings in the frequency of vegetation disturbances: around 2003 and around 2014, and the proportions of more than twice disturbances in a single location were low. The results illustrate that this framework is promising for the characterization of regional vegetation growth, including long-term trends and short-term features. The proposed framework enlightens a new direction for the continuous monitoring of vegetation dynamics.


Assuntos
Ecossistema , Monitoramento Ambiental , Fatores de Tempo , Monitoramento Ambiental/métodos , Florestas , Tecnologia de Sensoriamento Remoto , Mudança Climática , China
19.
Conscious Cogn ; 112: 103533, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37263078

RESUMO

Metacognition is the process by which we know what we know. Knowing has both declarative and sensed components. Differences exist in the information that moves to our conscious awareness and how it is synthesised with existing knowledge. The current study measured metacognition by extending a visual change detection paradigm that promoted explicit or implicit detection by either a local or global manipulation of a scene. A within-subjects design was used to investigate how 91 participants detected change and made metacognitive judgements. Cognitive modelling, based on confidence judgements, estimated the relative contributions of discrete and continuous cognitive processes to change detection, and to metacognition. Metacognition was sensitive to both the discrete and continuous processes underlying change detection, but was more sensitive to the discrete process. These results demonstrate that metacognition attunes confidence differentially to explicit and implicit processes, and support direct-access theories for discrete processing and meta-representation theories for continuous processing.


Assuntos
Metacognição , Humanos , Julgamento
20.
Conscious Cogn ; 107: 103446, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36508897

RESUMO

In three experiments we investigated the effects of selective attention in iconic memory and fragile-visual short-term memory (VSTM), which have been related to phenomenal consciousness. We used a novel retro-cue paradigm with different delays (early vs late) and object priorities (high vs equal vs low), to investigate (a) attentional costs and benefits and the role of (b) bottom-up factors and (c) fragile-VSTM in feature-based attentional selection. Experiment 1 showed that attentional costs modulate visual maintenance at longer delays, while Experiment 2 showed that by reducing the time exposure of the memory array from 250 ms to 100 ms, as a bottom-up factor, participants were not able to select the objects based on their priorities. Finally, Experiment 3 showed that a pattern mask presented before the transfer in visual working memory, attenuates the overall performance while preserving the priority effect. The implications for phenomenal consciousness before conscious access are discussed.


Assuntos
Atenção , Estado de Consciência , Humanos , Memória de Curto Prazo , Percepção Visual , Sinais (Psicologia)
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA