Pattern Correlation Analysis Research Articles

In vitro burn model illustrating heat conduction patterns using compressed thermal papers.

To date, heat conduction from heat sources to tissue has been estimated by complex mathematical modeling. In the present study, we developed an intuitive in vitro skin burn model that illustrates heat conduction patterns inside the skin. This was composed of tightly compressed thermal papers with compression frames. Heat flow through the model left a trace by changing the color of thermal papers. These were digitized and three-dimensionally reconstituted to reproduce the heat conduction patterns in the skin. For standardization, we validated K91HG-CE thermal paper using a printout test and bivariate correlation analysis. We measured the papers' physical properties and calculated the estimated depth of heat conduction using Fourier's equation. Through contact burns of 5, 10, 15, 20, and 30 seconds on porcine skin and our burn model using a heated brass comb, and comparing the burn wound and heat conduction trace, we validated our model. The heat conduction pattern correlation analysis (intraclass correlation coefficient: 0.846, p < 0.001) and the heat conduction depth correlation analysis (intraclass correlation coefficient: 0.93, p < 0.001) showed statistically significant high correlations between the porcine burn wound and our model. Our model showed good correlation with porcine skin burn injury and replicated its heat conduction patterns.

Boreal winter low‐frequency variability in CMIP5 models

AbstractThis study assesses the capability of CMIP5 models in representing primary modes of boreal winter extratropical low‐frequency variability. Rotated principal component analysis is applied to monthly mean output from historical simulations of 14 plus two variants models and National Centers for Environmental Prediction–National Center for Atmospheric Research reanalyses (NNR) to isolate the leading patterns of variability in 500 hPa height. For each model data set, North Atlantic Oscillation (NAO)‐like and Pacific‐North American (PNA)‐like patterns are identified using pattern correlation analysis (against NNR patterns). The relative pattern correspondence among CMIP5 models and reanalyses is further quantified via cluster analyses of the rotated empirical orthogonal function, NAO‐like, and PNA‐like patterns, respectively. For both NAO and PNA, 18.8% of the model patterns lie within the same cluster as NNR. Composite structural differences among clusters chiefly consist of (a) spatial displacements of or (b) regional magnitude disparities in the primary anomaly features. While all models replicate the basic aspects of PNA, a small minority of models fails to replicate NAO pattern. Overall, the best performing model is the “GFDL‐ESM2G.” Interestingly, models having a well‐resolved stratosphere generally perform more poorly than those without. Model biases in low‐frequency mode structure have important consequences for the representation of associated regional anomalies in surface air temperature and storm track behavior. Those differences among clusters are linked to variations in dynamical structures and their relation to the climatological‐mean flow. It is concluded that some state‐of‐the‐art models have important deficiencies in representing low‐frequency variability and some of these deficiencies are associated with the failure of models to adequately replicate the observed climatological stationary waves.

Functional Magnetic Resonance Imaging for Imaging Neural Activity in the Human Brain: The Annual Progress

Functional magnetic resonance imaging (fMRI) is recently developed and applied to measure the hemodynamic response related to neural activity. The fMRI can not only noninvasively record brain signals without risks of ionising radiation inherent in other scanning methods, such as CT or PET scans, but also record signal from all regions of the brain, unlike EEG/MEG which are biased towards the cortical surface. This paper introduces the fundamental principles and summarizes the research progress of the last year for imaging neural activity in the human brain. Aims of functional analysis of neural activity from fMRI include biological findings, functional connectivity, vision and hearing research, emotional research, neurosurgical planning, pain management, and many others. Besides formulations and basic processing methods, models and strategies of processing technology are introduced, including general linear model, nonlinear model, generative model, spatial pattern analysis, statistical analysis, correlation analysis, and multimodal combination. This paper provides readers the most recent representative contributions in the area.

The Relationship between the North Atlantic Jet and Tropical Convection over the Indian and Western Pacific Oceans

Abstract Boreal winter jet variability over the North Atlantic is investigated using 40-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40) data, where the variability is defined by the first EOF of the zonal wind on seven vertical levels. The principal component time series of this EOF is referred to as the jet index. A pattern correlation analysis indicates that the jet index more accurately describes intraseasonal North Atlantic zonal wind variability than does the North Atlantic Oscillation (NAO). A series of composite calculations of the jet index based on events of intraseasonal convective precipitation over the tropical Indian and western Pacific Oceans reveals the following statistically significant relationships: 1) negative jet events lead enhanced Indian Ocean precipitation, 2) positive jet events lag enhanced Indian Ocean precipitation, 3) positive jet events lead enhanced western Pacific Ocean precipitation, and 4) negative jet events lag enhanced western Pacific Ocean precipitation. These intraseasonal relationships are found to be linked through the circumglobal teleconnection pattern (CTP). Implications of the sign of the CTP being opposite to that of the jet index suggest that relationships 1 and 3 may arise from cold air surges associated with the CTP over these oceans. On interdecadal time scales, a much greater increase in the frequency of precipitation events from 1958 to 1979 (P1) to 1980 to 2001 (P2) was found for the Indian Ocean relative to the western Pacific Ocean. This observation, combined with relationships 2 and 4, leads to the suggestion that this change in the frequency of intraseasonal Indian Ocean precipitation events may make an important contribution to the excitation of interdecadal variability of the North Atlantic jet.

Urban roadside aromatic hydrocarbons in three cities of the Pearl River Delta, People's Republic of China

Urban roadside levels of benzene, toluene, ethylbenzene and xylenes (BTEX) were investigated in three typical cities (Guangzhou, Macau and Nanhai) in the Pearl River Delta Region of south China. Air samples were collected at typical ground level microenvironments by multi-bed adsorbent tubes. The BTEX concentrations were determined by thermal desorption–gas chromatography–mass selective detector (TD–GC–MSD) technique. The mean concentrations of benzene, toluene, ethylbenzene and xylenes were, respectively, 51.5, 77.3, 17.8 and 81.6 μg/m 3 in Guangzhou, 34.9, 85.9, 24.1, 95.6 μg/m 3 in Macau, and 20.0, 39.1, 3.0 and 14.2 μg/m 3 in Nanhai. The relative concentration distribution pattern and mutual correlation analysis indicated that in Macau BTEX were predominantly traffic-related while in Guangzhou benzene had sources other than vehicle emission. In Nanhai, both benzene and toluene had different sources other than vehicle emission. The samples collected from Guangzhou showed that BTEX had significant higher concentrations in November than those in July.

Genome flux in tomato cell clones cultured in vitro in different physiological equilibria. II. A RAPD analysis of variability

An analysis of the effect of changing physiological conditions on genome evolution in tomato cell populations has been carried out on long-term in vitro cultured clones grown on different auxin-cytokinin equilibria or selected for low-high competence for active defense against Fusarium oxysporum f.sp. lycopersici. RAPD analysis, confirmed through pattern rehybridization, was used as a random tool to measure the genetic variability. Through the use of a modified ANOVA, variation was shown to depend on both the initial genotype and the physiological conditions. Pattern correlation analysis through a mutual information algorithm suggested the fixation of RAPD patterns specific to physiological equilibria. The results are discussed in view of the possible relevance for evolution at hierarchical levels higher than cell populations. Key words : tomato clones, somaclonal variation, RAPD, coadaptation.

Inegrated autocorrelation method for plastic strain determination

This paper presents an integrated autocorrelation method for the measurement of plastic deformation in metallic materials. The method employs a laser beam to illuminate the test objects. The diffracted images are digitised, recorded and processed on a computer based image processing system. The subsequent speckle pattern correlation analysis yields information on the surface deformation of the test objects. The technique is applied to brass tensile specimens and it is found that the integrated autocorrelation coefficient is linearly proportional to the plastic shear strain. For the range of plastic strain measured the error involved would be less than 10%.