Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “spatiotemporal analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed2026

Genome-wide identification of HCT gene family in sugarcane (Saccharum spp. hybrid) and characterization of putative cis-elements in gene regulation.

BACKGROUND: Sugarcane (Saccharum spp. hybrid) is a globally important crop, and its bagasse can be converted into bioethanol and other industrial products. Lignin, a core component of sugarcane cell walls, plays a crucial role in bagasse quality and lodging resistance. Shikimic acid hydroxycinnamyl transferase (HCT) is the key enzyme in lignin biosynthesis. However, the HCT gene family in sugarcane and its regulatory roles in sugarcane remain poorly understood. RESULTS: A total of 663 HCT genes (including alleles) were identified in the Saccharum hybrid R570 genome, which were classified into six groups (I-VI) and were unevenly distributed across 77 chromosomes. Bioinformatics analysis revealed that the subgroups of R570HCTs had similar gene structures, suggesting conserved functions. Moreover, the different subgroups presented unique putative cis‑element distribution patterns. Transcriptome data indicated that some R570HCTs exhibited significant spatiotemporal and tissue‑specific expression patterns. Further Pearson correlation analysis between putative cis‑element distribution and normalized expression values at the subgroup level revealed that light-responsive elements (L‑box and GA‑motif) were positively correlated with R570HCT expression, and different subgroups formed a complex regulatory network by integrating hormone response and stress elements. Importantly, this subgroup-level correlation was cross-validated by comparing the cis‑element clustering heatmap with the expression heatmap, revealing consistent enrichment patterns. CONCLUSIONS: The study's findings provide novel insights into the correlation among motifs, putative cis‑elements, and gene expression, and propose a cross-validated framework for understanding regulatory divergence among HCT subfamilies in polyploid sugarcane, serving as a hypothesis generating resource for future research on R570HCT expression.

Saccharum↗
PubMed1992

Evoked potential and psychophysical analysis of Fourier and non-Fourier motion mechanisms.

Some visual stimuli produce a strong percept of motion, even though they fail to excite motion detectors based on Fourier energy or cross correlation. Models which suffice to explain the motion percept in these non-Fourier motion (NFM) stimuli include linear spatiotemporal filtering, followed by rectification, followed by standard motion analysis (Chubb & Sperling 1988). We used the human "motion-onset" evoked potential, which has been assigned to area 17 on the basis of work in the macaque (van Dijk et al., 1986; van Dijk & Spekreijse, 1989), to investigate the neural substrate of the processing stages postulated in the above models. Motion-onset VEPs elicited by FM and NFM matched for spatial and temporal characteristics were indistinguishable in temporal characteristics and scalp topography at a transverse chain of electrodes. Addition of textural cues (granularity and higher-order form) did not influence the response dynamics or scalp topography of NFM responses. However, comparison of responses to NFM stimuli and related stimuli without coherent motion but similar spatial and temporal properties showed that the motion-onset responses were distinct from responses to the onset of fixed flicker-defined contours not undergoing coherent motion. We discuss the implications of these results for computational models of motion analysis.

Adult↗
PubMed1991

Autokinetic illusion as affected by suggestions of experimenter and observer.

Two experiments were done to examine whether an experimenter's suggestion and self-suggestion could affect the autokinetic illusion and to specify that effect. Exp. I compared the effect of a facilitative suggestion with a suppressive one, by measuring the moving latency, duration, frequency, and by analyzing the movement trace. Time and frequency did not detect any effects of marked individual differences. Trace analysis, on the other hand, showed that suggestions were effective in the expected direction for some subjects. Exp. II gave the suggestion for and against subjects' dominant direction of the movement and was designed to specify the effect. While effects indicated by time and frequency measures were not consistent, the movement trace showed the effect in suggested directions, which was more distinct for subjects whose nonsuggested illusion was not so markedly directed. These findings indicate that suggestion could affect the spatiotemporal aspect of the illusion, so the trace analysis may be useful for studies in this field.

Adult↗
PubMed2005

Motor function and joint position sense in relation to gait performance in chronic stroke patients.

OBJECTIVES: To determine the association between joint position sense (JPS) and motor function of the lower extremity and gait performance of patients with chronic stroke. DESIGN: Single-group cross-sectional design. SETTING: University gait laboratory. PARTICIPANTS: Twenty-one patients with stroke onset of more than 6 months. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The isometric strength, Fugl-Meyer Assessment (FMA) motor status, and JPS of the lower extremity were tested. Spatiotemporal gait characteristics were measured using a 6-camera motion analysis system, with patients walking at their comfortable speeds while using their usual devices. RESULTS: Lower-extremity muscle strength and FMA motor score correlated significantly with the spatiotemporal characteristics of gait and contributed significantly to the variance in gait velocity, stride length, and double-stance time. The JPS was not related to gait performance, except that the ankle JPS contributed significantly to the variance in gait velocity and stride length. CONCLUSIONS: For patients with chronic stroke, motor function was significantly related to gait performance. Although the JPS was not, that of the ankle joint made a significant contribution. When enhancing gait performance is desired, improving the motor function is recommended, and the role of JPS should also be taken into consideration.

Aged↗
PubMed1999

[Event-related desynchronization and Parkinson disease. Importance in the analysis of the phase of preparation for movement].

This study was aimed at determining the spatiotemporal distribution of event-related desynchronization (ERD) during self-paced voluntary movement in order to establish the interest of this method for the analysis of movement programming in Parkinson's disease. Desynchronization of mu rhythm was recorded 2 s before to 0.5 s after right then left self-paced voluntary wrist flexions from 11 leads covering the primary sensorimotor cortex (central), supplementary motor area (frontocentral) and parietal cortex (parietocentral). Recordings were obtained from ten control subjects, ten patients treated for Parkinson's disease (bilateral symptoms) and 20 patients presenting with right or left hemiparkinsonism before and after chronic administration of L-dopa. In the control group, ERD started over the contralateral primary sensorimotor cortex 1,750 ms before movement and was bilateral just before performance of the movement. In both treated and de novo Parkinson's disease groups, decrease in ERD latency (1,000 to 1,250 ms before movement) was only observed when movements were performed with the akinetic hand and corresponded to a decrease in motor cortical activity. This confirmed that programming of movement is affected in Parkinson's disease. Earlier ERD with central ipsilateral distribution were also observed, suggesting that other cortical areas might be activated to compensate for dysfunction of movement programming and to increase the level of cortical activity required for performance of the movement. The administration of L-dopa to de novo hemiparkinsonians patients resulted in increased ERD latency over contralateral and ipsilateral central areas. As in the treated Parkinson's disease group, frontocentral ERD could also be recorded. L-dopa would thus partially restore the affected motor programmation and modulate cortical activation in both supplementary motor area and primary motor cortex, the later receiving more afferences from basal ganglia.

Antiparkinson Agents↗
PubMed2003

Multivariate analysis of neuronal interactions in the generalized partial least squares framework: simulations and empirical studies.

Identification of spatiotemporal interactions within/between neuron populations is critical for detection and characterization of large-scale neuronal interactions underlying perception, cognition, and behavior. Univariate analysis has been employed successfully in many neuroimaging studies. However, univariate analysis does not explicitly test for interactions between distributed areas of activity and is not sensitive to distributed responses across the brain. Multivariate analysis can explicitly test for multiple statistical models, including the designed paradigm, and allows for spatial and temporal model detection. Here, we investigate multivariate analysis approaches that take into consideration the 4D (time and space) covariance structure of the data. Principal component analysis (PCA) and independent component analysis (ICA) are two popular multivariate approaches with distinct mathematical constraints. Common difficulties in using these two different decompositions include the following: classification of the revealed components (task-related signal versus noise), overall signal-to-noise sensitivity, and the relatively low computational efficiency (multivariate analysis requires the entire raw data set and more time for model identification analysis). Using both Monte Carlo simulations and empirical data, we derived and tested the generalized partial least squares (gPLS) framework, which can incorporate both PCA and ICA decompositions with computational efficiency. The gPLS method explicitly incorporates the experimental design to simplify the identification of characteristic spatiotemporal patterns. We performed parametric modeling studies of a blocked-design experiment under various conditions, including background noise distribution, sampling rate, and hemodynamic response delay. We used a randomized grouping approach to manipulate the degrees of freedom of PCA and ICA in gPLS to characterize both paradigm coherent and transient brain responses. Simulation data suggest that in the gPLS framework, PCA mostly outperforms ICA as measured by the receiver operating curves (ROCs) in SNR from 0.01 to 100, the hemodynamic response delays from 0 to 3 TR in fMRI, background noise models of Guassian, sub-Gaussian, and super-Gaussian distributions and the number of observations from 5, 10, to 20 in each block of a six-block experiment. Further, due to selective averaging, the gPLS method performs robustly in low signal-to-noise ratio (<1) experiments. We also tested PCA and ICA using PLS in a simulated event-related fMRI data to show their similar detection. Finally, we tested our gPLS approach on empirical fMRI motor data. Using the randomized grouping method, we are able to identify both transient responses and consistent paradigm/model coherent components in the 10-epoch block design motor fMRI experiment. Overall, studies of synthetic and empirical data suggest that PLS analysis, using PCA decomposition, provides a stable and powerful tool for exploration of fMRI/behavior data.

Algorithms↗
PubMed2002

Method for detecting the signature of noise-induced structures in spatiotemporal data sets.

Spatiotemporal stochastic resonance (STSR) is a phenomenon, where the stability of spatial patterns in an extended dynamical system displays a resonance-type dependence on the noise amplitude with the patterns being optimal at intermediate noise level. This dynamical behavior has been found in theoretical systems as well as in biochemical processes, where the noise level has been controlled externally. However, it is an open question how to identify the signature of a spatiotemporal stochastic resonance in a natural system, e.g., in ecology, when the noise amplitude is not known. This question is addressed in the present paper. We provide analysis tools, which allow to reconstruct the noise intensity in a spatiotemporal data set from the data alone. These tools are based on nearest-neighbor considerations inspired by cellular automata and are an appropriate method for detecting STSR, when combined with some measure of spatial order. As a test of our analysis tools, we apply them to sample data generated by four theoretical model systems. We show explicitly that without knowledge of the theoretical value of the noise amplitude for those systems displaying STSR the corresponding resonance curve can be reconstructed from the data alone. In addition, the other (nonresonant) cases are properly identified by our method with no resonance curve being found.

Journal Article↗
PubMed1994

Implications of motion detection for early non-linearities.

Analysis of motion may be accomplished using the spatiotemporal variations produced when a spatially varying luminance waveform moves across linear receptive fields. Moving contrast-modulated patterns which consist of coarse-scale spatial variations in the contrast of fine-scale luminance patterns cannot be analysed in this way. The human visual system can analyse the motion of contrast-modulated patterns and this suggests it may contain mechanisms that use non-linear transformations. Non-linear transformation of contrast-modulated patterns would give rise to a component (a distortion product) that varies on the same spatial scale as the contrast variation; this can be analysed to extract motion. Is the non-linearity simply an inherent part of the transduction process or is it a characteristic of a mechanism specialized for the analysis of the motion of such patterns? Comparisons of the spatial and temporal limitations of motion discrimination using luminance and contrast-modulated patterns suggest that the mechanisms which analyse the two types of patterns are different, although recent physiological evidence suggests that they may have common elements.

Animals↗
PubMed2026

Phylogeography and molecular evolution of Newcastle disease virus across a century of global surveillance.

Newcastle disease virus (NDV) remains one of the most economically important avian pathogens worldwide, causing recurrent outbreaks in poultry despite decades of vaccination and disease control efforts. Since the first reported outbreak of NDV a hundred years ago, numerous molecular epidemiological studies have been conducted globally across diverse geographic and production settings. Following a century of NDV circulation and evolution, the present study aimed to compile all publicly available NDV sequence data and perform a comprehensive global analysis of the genetic diversity, phylogenetic relationship, and global spatiotemporal distribution of NDV over a 100-year timescale. All publicly available NDV complete genome and full-length fusion (F) gene sequences were retrieved from GenBank up to February 2026. Following rigorous quality control, phylogenetic analyses were performed based on complete genomes and F gene datasets. Phylogenetic analysis identified two genotypes within Class I and 20 genotypes within Class II NDVs, with extensive diversification at the sub-genotype level. Genotype XIII exhibited the greatest sub-genotypic diversity, while genotype VII represented the most globally disseminated genotype, reported across 36 countries. Chronological assessment based on the earliest available reports indicated an increasing number of recognized genotypes from the 1930s to recently described sub-genotypes such as XIII.2.3 and XXII.2.2. Regional diversity analysis revealed the highest genotype diversity in Western Africa, Eastern Asia, and Southern Asia. Comparative residue analysis demonstrated substantial genotype-specific variation within critical functional domains of the fusion protein, including cleavage sites, neutralizing epitopes, and heptad repeat regions. Overall, this study provides the first comprehensive 100-year global overview of NDV evolution and phylogeography. The findings highlight continuous viral diversification, broad geographic dissemination of multiple genotypes, and ongoing molecular variation, emphasizing the need for sustained genomic surveillance and periodic evaluation of vaccine compatibility with emerging NDV genotypes.

100-years of data↗
PubMed1985

The spatiotemporal properties of the r-g X-cell channel.

Analysis of the simple-opponent r-g receptive field of the X-channel shows that it is tuned to both high and low temporal frequencies, high and low spatial frequencies, and that its spectral sensitivity is both chromatic and achromatic.

Animals↗
PubMed1998

Infants' acquisition of spatiotemporal expectations.

The microdevelopment of infants' visual expectations was examined by analysis of the eye movements that 80 three-month-old human infants made during interstimulus intervals (ISIs) of an alternating picture sequence. For comparison, identical eye movement data were gathered from 10 infants who watched an irregular sequence. Shifts during ISIs were exhibited by all infants and occurred on 48% of all trials. Initially, infants' ISI shifts repeated saccades that had successfully located the preceding picture; during the course of the alternating session, repetitive saccades declined while alternating and anticipatory saccades increased. For infants who saw the irregular sequence, the frequency of ISI shifts did not vary systematically over trials. Analysis of saccade latencies suggested that infants quickly learned to inhibit a prepotent tendency in order to execute task-appropriate saccades.

Female↗
PubMed2005

Combined ICA-LORETA analysis of mismatch negativity.

A major challenge for neuroscience is to map accurately the spatiotemporal patterns of activity of the large neuronal populations that are believed to underlie computing in the human brain. To study a specific example, we selected the mismatch negativity (MMN) brain wave (an event-related potential, ERP) because it gives an electrophysiological index of a "primitive intelligence" capable of detecting changes, even abstract ones, in a regular auditory pattern. ERPs have a temporal resolution of milliseconds but appear to result from mixed neuronal contributions whose spatial location is not fully understood. Thus, it is important to separate these sources in space and time. To tackle this problem, a two-step approach was designed combining the independent component analysis (ICA) and low-resolution tomography (LORETA) algorithms. Here we implement this approach to analyze the subsecond spatiotemporal dynamics of MMN cerebral sources using trial-by-trial experimental data. We show evidence that a cerebral computation mechanism underlies MMN. This mechanism is mediated by the orchestrated activity of several spatially distributed brain sources located in the temporal, frontal, and parietal areas, which activate at distinct time intervals and are grouped in six main statistically independent components.

Adult↗
PubMed2001

Effects of bilateral pallidal or subthalamic stimulation on gait in advanced Parkinson's disease.

Bilateral high-frequency stimulation of the internal globus pallidus (GPi) and the subthalamic nucleus (STN) both alleviate akinesia, rigidity, and tremor in idiopathic Parkinson's disease. To test the specific effect of these procedures on gait, we used quantitative gait analysis in addition to relevant subscores of the Unified Parkinson's Disease Rating Scale in a group of 10 patients with advanced Parkinson's disease treated by GPi stimulation and eight patients treated by STN stimulation. Patients were assessed before and 3 months after surgery. Thirty age-matched healthy subjects served as controls. The non-random selection allowed a descriptive but no direct statistical comparison of the respective procedure. Gait analysis showed significant stimulation-induced improvements of spatiotemporal gait and step parameters in both patient groups. Moreover, the effects on step length and cadence suggested a differential effect of both basal ganglia targets. Hence, the increase in gait velocity in the STN group was almost exclusively due to a significant increase in step length, while in the GPi group statistically non-significant increases in both step length and cadence contributed.

Aged↗
PubMed2006

Shear wave group velocity inversion in MR elastography of human skeletal muscle.

In vivo quantification of the anisotropic shear elasticity of soft tissue is an appealing objective of elastography techniques because elastic anisotropy can potentially provide specific information about structural alterations in diseased tissue. Here a method is introduced and applied to MR elastography (MRE) of skeletal muscle. With this method one can elucidate anisotropy by means of two shear moduli (one parallel and one perpendicular to the muscle fiber direction). The technique is based on group velocity inversion applied to bulk shear waves, which is achieved by an automatic analysis of wave-phase gradients on a spatiotemporal scale. The shear moduli are then accessed by analyzing the directional dependence of the shear wave speed using analytic expressions of group velocities in k-space, which are numerically mapped to real space. The method is demonstrated by MRE experiments on the biceps muscle of five volunteers, resulting in 5.5+/-0.9 kPa and 29.3+/-6.2 kPa (P<0.05) for the medians of the perpendicular and parallel shear moduli, respectively. The proposed technique combines fast steady-state free precession (SSFP) MRE experiments and fully automated processing of anisotropic wave data, and is thus an interesting MRI modality for aiding clinical diagnosis.

Adult↗
PubMed2024

Myosin XI-mediated BIK1 recruitment to nanodomains facilitates FLS2-BIK1 complex formation during innate immunity in Arabidopsis.

Plants rely on immune receptor complexes at the cell surface to perceive microbial molecules and transduce these signals into the cell to regulate immunity. Various immune receptors and associated proteins are often dynamically distributed in specific nanodomains on the plasma membrane (PM). However, the exact molecular mechanism and functional relevance of this nanodomain targeting in plant immunity regulation remain largely unknown. By utilizing high spatiotemporal resolution imaging and single-particle tracking analysis, we show that myosin XIK interacts with remorin to recruit and stabilize PM-associated kinase BOTRYTIS-INDUCED KINASE 1 (BIK1) within immune receptor FLAGELLIN SENSING 2 (FLS2)-containing nanodomains. This recruitment facilitates FLS2/BIK1 complex formation, leading to the full activation of BIK1-dependent defense responses upon ligand perception. Collectively, our findings provide compelling evidence that myosin XI functions as a molecular scaffold to enable a spatially confined complex assembly within nanodomains. This ensures the presence of a sufficient quantity of preformed immune receptor complex for efficient signaling transduction from the cell surface.

Arabidopsis↗
PubMed2002

Growth of binary fluid convection: role of the concentration field.

The growth of convection in binary fluid mixtures out of different perturbations of the quiescent conductive state is investigated using finite-difference numerical simulations for realistic ethanol-water parameters with strong negative Soret coupling between temperature and concentration fluctuations. Several different analysis tools are used to elucidate the complex spatiotemporal behavior associated with the dramatic concentration redistribution during the transients. It shows first the competition between counterpropagating waves that initially superimpose to form standing wave perturbations. Having reached a critical amplitude an advective breaking of the concentration wave triggers a very fast flow-induced transition from standing to traveling wave convection with large phase velocity and large concentration field amplitudes. Strongly nonlinear advective mixing and weak long-time diffusive homogenization then slow down the waves.

Journal Article↗
PubMed2002

Transition from Townsend to glow discharge: subcritical, mixed, or supercritical characteristics.

The transition from Townsend to glow discharge is investigated numerically in one space dimension in full parameter space within the classical model: with electrons and positive ions drifting in the local electric field, impact ionization by electrons (alpha process), secondary electron emission from the cathode (gamma process) and space charge effects. We also perform a systematic analytical small current expansion about the Townsend limit up to third order in the current that fits our numerical data very well. Depending on the two determining parameters gamma and system size pd, the transition from Townsend to glow discharge can show the textbook subcritical behavior, but for smaller values of pd, we also find supercritical or some unexpected intermediate "mixed" behavior. Our work shows the same qualitative dependence of U=U(I,pd) for fixed gamma as the old experiments by Pokrovskaya-Soboleva and Klyarfeld. Furthermore, the analysis lays the basis for understanding the complex spatiotemporal patterns in short planar barrier discharge systems.

Journal Article↗