Search results for "PCA"
showing 10 items of 130 documents
Reuse of Food Waste: The Chemical Composition and Health Properties of Pomelo (Citrus maxima) Cultivar Essential Oils
2022
The aim of the present study is to investigate the chemical profile, antioxidant activity, carbohydrate-hydrolysing enzyme inhibition, and hypolipidemic effect of essential oils (EOs) extracted from Sicilian Citrus maxima (pomelo) flavedo. Using gas-chromatography-mass spectrometry analysis (GC-MS) we analysed the Eos of five cultivars of C. maxima, namely, ‘Chadock’, ‘Maxima’, ‘Pyriformis’, ‘Terracciani’, and ‘Todarii’, and their blends. The antioxidant activity was performed by using a multi-target approach using 2,2′-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic acid (ABTS), 2,2-Diphenyl-1-picrylhydrazyl (DPPH), ferric reduc…
Multiple factor analysis: principal component analysis for multitable and multiblock data sets
2013
On application of kernel PCA for generating stimulus features for fMRI during continuous music listening
2018
Background There has been growing interest towards naturalistic neuroimaging experiments, which deepen our understanding of how human brain processes and integrates incoming streams of multifaceted sensory information, as commonly occurs in real world. Music is a good example of such complex continuous phenomenon. In a few recent fMRI studies examining neural correlates of music in continuous listening settings, multiple perceptual attributes of music stimulus were represented by a set of high-level features, produced as the linear combination of the acoustic descriptors computationally extracted from the stimulus audio. New method fMRI data from naturalistic music listening experiment were…
Optimal Spectral Wavelengths for Discriminating Orchard Species Using Multivariate Statistical Techniques
2019
Sustainable management of orchard fields requires detailed information about the tree types, which is a main component of precision agriculture programs. To this end, hyperspectral imagery can play a major role in orchard tree species mapping. Efficient use of hyperspectral data in combination with field measurements requires the development of optimized band selection strategies to separate tree species. In this study, field spectroscopy (350 to 2500 nm) was performed through scanning 165 spectral leaf samples of dominant orchard tree species (almond, walnut, and grape) in Chaharmahal va Bakhtiyari province, Iran. Two multivariable methods were employed to identify the optimum wavelengths:…
Detección de nuevos marcadores asociados a daño por reperfusión y fibrosis en infarto de miocardio validados histopatológicamente mediante análisis m…
2022
La resonancia magnética cardiovascular (RMC) con realce tardío es la técnica de referencia para la evaluación no invasiva del daño cardíaco después de un infarto de miocardio (IM). Sin embargo, la interpretación de estas imágenes en términos de daño tisular es aún complicado y el uso de agentes de contraste en esta técnica está contraindicado en un amplio sector de la población con insuficiencia renal crónica. La microscopía de resonancia magnética (MRM) proporciona un nivel de detalle comparable al objetivo macroscópico de la microscopía óptica. Por ello, podría ser una herramienta muy útil en la interpretación de la imagen de RMC y en la identificación de nuevos marcadores de imagen de re…
Determination of Changes in the Quality of Surface Water in the River—Reservoir System
2021
Assessing the changing parameters of water quality at different points in the river–reservoir system can help prevent river pollution and implement remedial policies. It is also crucial in modeling water resources. Multivariate statistical analysis is useful for the analysis of changes in surface water quality. It helps to identify indicators that may be responsible for the eutrophication process of a reservoir. Additionally, the analysis of the water quality profile and the water quality index (WQI) is useful in assessing water pollution. These tools can support and verify the results of a multivariate statistical analysis. In this study, changes in water quality parameters of the Turawa r…
Improved chemometric approach for XRF data treatment: application to the reverse glass paintings from the Lipari collection
2023
The Aeolian cultural heritage preserves hundreds of testimonies of the past that have passed through six millennia of history. Among these, the Archeological Park of the Aeolian Islands with the Museum Luigi Bernab`o Brea (Italy) preserves a valuable set of artworks, which are related to a little-known ‘popular’ figurative heritage. It is an assemblage of small glass foils decorated using the technique of reverse painting, datable to between the end of the 17th century and the end of the 18th century, and actually under investigation by historians. Here, an X-ray fluorescence (XRF) spectroscopy study (performed with portable equipment) is combined with a multivariate approach that allows us…
Chemical composition of the essential oil of Centaurea grinensis Reuter and Centaurea apiculata Ledeb: Growing wild in Croatia and Bulgaria, respecti…
2016
AbstractIn the present study, the chemical composition of the essential oils from aerial parts of Centaurea grinensis Reuter (K) collected at Žuta Lova, near Senj (Croatia), and aerial parts (L1) and flowers (L2) of C. apiculata Ledeb. collected near Rebro village, near Breznik town, Znepole Region (Bulgaria), both belonging to subgenus Lopholoma (Cass.) Dobrocz, was evaluated by GC and GC-MS. The main components of K were 4-vinyl guaiacol (21.5%), hexadecanoic acid (16.2%), acetophenone (12.5%). Caryophyllene oxide (15.8%) together with sphathulenol (14.5%) and humulene epoxide II (9.4%) were recognized as the main constituent of both the aerial part (L1) and flowers (L2) of C. apiculata. …
Combining PCA and multiset CCA for dimension reduction when group ICA is applied to decompose naturalistic fMRI data
2015
An extension of group independent component analysis (GICA) is introduced, where multi-set canonical correlation analysis (MCCA) is combined with principal component analysis (PCA) for three-stage dimension reduction. The method is applied on naturalistic functional MRI (fMRI) images acquired during task-free continuous music listening experiment, and the results are compared with the outcome of the conventional GICA. The extended GICA resulted slightly faster ICA convergence and, more interestingly, extracted more stimulus-related components than its conventional counterpart. Therefore, we think the extension is beneficial enhancement for GICA, especially when applied to challenging fMRI d…
Implementation of an innovative technique to improve Sauvignon Blanc wine quality
2018
The purpose of the study was to compare two different pressing systems of Sauvignon Blanc grapes using an innovative wine press manufactured by Puleo Srl Company (Marsala, Italy). Grape pressing is a very important step in the winemaking process as it may promote the presence and/or absence of enzyme processes on the must, leading to the creation of different products in terms of chemical composition from the same grapes. Chemical composition of must firstly and wine after, obtained from the two pressing mode, was analysed in first instance with PCA method.