keyword
MENU ▼
Read by QxMD icon Read
search

Principal components analysis

keyword
https://www.readbyqxmd.com/read/28806714/f-norm-distance-metric-based-robust-2dpca-and-face-recognition
#1
Tao Li, Mengyuan Li, Quanxue Gao, Deyan Xie
Two-dimensional principal component analysis (2DPCA) employs squared F-norm as the distance metric for dimensionality reduction. It is commonly known that squared F-norm is sensitive to the presence of outliers. To address this problem, we use F-norm instead of squared F-norm as the distance metric in the objective function and develop a non-greedy algorithm, which has a closed-form solution in each iteration and can maximize the criterion function, to solve the optimal solution. Our approach not only is robust to outliers but also well characterizes the geometric structure of data...
July 21, 2017: Neural Networks: the Official Journal of the International Neural Network Society
https://www.readbyqxmd.com/read/28806597/a-nested-multivariate-chemometrics-based-calibration-strategy-for-direct-trace-biometal-analysis-in-soft-tissue-utilizing-energy-dispersive-x-ray-fluorescence-edxrf-and-scattering-spectrometry
#2
REVIEW
J J Okonda, K H Angeyo, J M Mangala, S M Kisia
Compton scatter-modulated fluorescence and multivariate chemometric (artificial neural network (ANN) and principal component regression (PCR)) calibration strategy was explored for direct rapid trace biometals (Mn, Fe, Cu, Zn, Se) analysis in "complex" matrices (model soft tissues). This involved spectral feature selection (multiple fluorescence signatures) normalized to or in conjunction with Compton scatter. ANN model resulted in more accurate trace biometal determination (R(2)>0.9) compared to PCR. Hybrid nested (ANN and PCR) approach led to optimized accurate biometals' concentrations in Oyster tissue (≤ ± 10%)...
August 8, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28806590/how-multi-segmental-patterns-deviate-in-spastic-diplegia-from-typical-developed
#3
Matteo Zago, Chiarella Sforza, Alessia Bona, Veronica Cimolin, Pier Francesco Costici, Claudia Condoluci, Manuela Galli
BACKGROUND: The relationship between gait features and coordination in children with Cerebral Palsy is not sufficiently analyzed yet. Principal Component Analysis can help in understanding motion patterns decomposing movement into its fundamental components (Principal Movements). This study aims at quantitatively characterizing the functional connections between multi-joint gait patterns in Cerebral Palsy. METHODS: 65 children with spastic diplegia aged 10.6 (SD 3...
August 8, 2017: Clinical Biomechanics
https://www.readbyqxmd.com/read/28806565/implications-of-biological-factors-on-accumulation-of-persistent-organic-pollutants-in-antarctic-notothenioid-fish
#4
J M Ríos, N B Lana, N F Ciocco, A Covaci, E Barrera-Oro, E Moreira, J C Altamirano
In the present study, the possible associations between selected persistent organic pollutants (POPs) and biological factors were assessed in different tissues of two Antarctic notothenioid fish: Notothenia rossii (NOR) and Trematomus newnesi (TRN) collected at Potter Cove, King George Island/Isla 25 de Mayo, South Shetland Islands. Specifically, association patterns between biological factors (body size, lipid content, body condition) and POP concentrations (polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and metabolites, polybrominated diphenyl ethers (PBDEs), and hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), chlordanes (CHLs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs)), were explored by using two approaches: multivariate analyses (principal component analysis: PCA) and intraspecific correlations...
August 11, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28805930/reliability-of-the-qualitative-behavior-assessment-as-included-in-the-welfare-quality-assessment-protocol-for-growing-pigs
#5
I Czycholl, E Grosse Beilage, C Henning, J Krieter
Positive emotions constitute a very important part of animal welfare. They are, however, also the most challenging elements to be objectively measured. Due to its feasibility, the qualitative behavior assessment (QBA) is included in the Welfare Quality Assessment protocol for growing pigs as the animal-based measurement tool for positive emotions. Reliability testing on the QBA in the form as included in the protocols is, however, rare. Therefore, the present study aimed at the evaluation of the inter- and intraobserver as well as test-retest reliability of the QBA in growing pigs...
August 2017: Journal of Animal Science
https://www.readbyqxmd.com/read/28805384/lipidomics-insights-in-health-and-nutritional-intervention-studies
#6
Clara Ibañez, Lamia Mouhid, Guillermo Reglero, Ana Ramirez de Molina
Lipids are among the major components of food and constitute the principal structural biomolecules of human body together with proteins and carbohydrates. Lipidomics encompasses the investigation of the lipidome, defined as the entire spectrum of lipids in a biological system at a given time. Among metabolomics technologies, Lipidomics has evolved due to the relevance of lipids in nutrition and their well-recognized roles in health. Mass spectrometry advances have greatly facilitated Lipidomics but owing to the complexity and diversity of the lipids, lipidome purification and analysis is still challenging...
August 14, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28805139/mental-representation-of-fractions-it-all-depends-on-whether-they-are-common-or-uncommon
#7
Fuchang Liu
This study examined whether common and uncommon fractions are mentally represented differently and whether common ones are used in accessing the magnitudes of uncommon ones. In Experiments 1 and 2, college education majors, most of whom were female, Caucasian, and in their early 20s, made comparisons involving common and uncommon fractions. In Experiment 3, participants were presented with comparison tasks involving uncommon fractions and asked to describe the strategies which they used in making such comparisons...
August 13, 2017: Quarterly Journal of Experimental Psychology: QJEP
https://www.readbyqxmd.com/read/28804506/improved-k-t-pca-algorithm-using-artificial-sparsity-in-dynamic-mri
#8
Yiran Wang, Zhifeng Chen, Jing Wang, Lixia Yuan, Ling Xia, Feng Liu
The k-t principal component analysis (k-t PCA) is an effective approach for high spatiotemporal resolution dynamic magnetic resonance (MR) imaging. However, it suffers from larger residual aliasing artifacts and noise amplification when the reduction factor goes higher. To further enhance the performance of this technique, we propose a new method called sparse k-t PCA that combines the k-t PCA algorithm with an artificial sparsity constraint. It is a self-calibrated procedure that is based on the traditional k-t PCA method by further eliminating the reconstruction error derived from complex subtraction of the sampled k-t space from the original reconstructed k-t space...
2017: Computational and Mathematical Methods in Medicine
https://www.readbyqxmd.com/read/28802824/highly-accurate-prediction-of-protein-self-interactions-by-incorporating-the-average-block-and-pssm-information-into-the-general-pseaac
#9
Jing-Xuan Zhai, Tian-Jie Cao, Ji-Yong An, Yong-Tao Bian
It is a challenging task for fundamental research whether proteins can interact with their partners. Protein self-interaction (SIP) is a special case of PPIs, which plays a key role in the regulation of cellular functions. Due to the limitations of experimental self-interaction identification, it is very important to develop an effective biological tool for predicting SIPs based on protein sequences. In the study, we developed a novel computational method called RVM-AB that combines the Relevance Vector Machine (RVM) model and Average Blocks (AB) for detecting SIPs from protein sequences...
August 9, 2017: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/28802670/chemoselective-fluorination-and-chemoinformatic-analysis-of-griseofulvin-natural-vs-fluorinated-fungal-metabolites
#10
Noemi D Paguigan, Mohammed H Al-Huniti, Huzefa A Raja, Austin Czarnecki, Joanna E Burdette, Mariana González-Medina, José L Medina-Franco, Stephen J Polyak, Cedric J Pearce, Mitchell P Croatt, Nicholas H Oberlies
Griseofulvin is a fungal metabolite and antifungal drug used for the treatment of dermatophytosis in both humans and animals. Recently, griseofulvin and its analogues have attracted renewed attention due to reports of their potential anticancer effects. In this study griseofulvin (1) and related analogues (2-6, with 4 being new to literature) were isolated from Xylaria cubensis. Six fluorinated analogues (7-12) were synthesized, each in a single step using the isolated natural products and Selectflour, so as to examine the effects of fluorine incorporation on the bioactivities of this structural class...
July 28, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/28802139/analysis-of-neurobehavioural-data-by-chemometric-methods-in-ecotoxicological-studies
#11
Cristian Gómez-Canela, Eva Prats, Romà Tauler, Demetrio Raldúa
Incorporation of chemometric tools in behavioural data management workflows allows for the early identification of most relevant endpoints complementarily to statistical confirmatory approaches. In this work, the effects of two model neurotoxicants, chlorpyrifos (CPF) and nicotine, exposures on behavioural profiles of adult zebrafish at three different times (2, 6 and 24h) were evaluated using open field test (OFT) paradigm experiments. Two chemometric methods like Principal Component Analysis (PCA) and Analysis of Variance-Simultaneous Component Analysis (ASCA) have been used to interpret the changes observed in the obtained behavioural data...
August 9, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28802105/combined-influence-of-multiple-climatic-factors-on-the-incidence-of-bacterial-foodborne-diseases
#12
Myoung Su Park, Ki Hwan Park, Gyung Jin Bahk
Information regarding the relationship between the incidence of foodborne diseases (FBD) and climatic factors is useful in designing preventive strategies for FBD based on anticipated future climate change. To better predict the effect of climate change on foodborne pathogens, the present study investigated the combined influence of multiple climatic factors on bacterial FBD incidence in South Korea. During 2011-2015, the relationships between 8 climatic factors and the incidences of 13 bacterial FBD, were determined based on inpatient stays, on a monthly basis using the Pearson correlation analyses, multicollinearity tests, principal component analysis (PCA), and the seasonal autoregressive integrated moving average (SARIMA) modeling...
August 9, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28801843/sex-estimation-of-infants-through-geometric-morphometric-analysis-of-the-ilium
#13
Enrique J Estévez, Sandra López-Lázaro, Claudia López-Morago, Inmaculada Alemán, Miguel C Botella
In archeology or forensics, the analysis of the ilia is often used to determine the age and sex of unknown individuals. However, sex determination using the skeletal remains of individuals who did not develop secondary sexual characteristics remains controversial. Accurately estimating the sex of subadults is hampered by a small number of studies based on identified skeletal collections of juvenile individuals. Here, we analyzed the sexual dimorphism of the subadult ilia using geometric morphometric techniques and individuals from the osteological collection of identified subadults from San José's graveyard (Granada)...
August 11, 2017: International Journal of Legal Medicine
https://www.readbyqxmd.com/read/28801833/concentrations-input-prediction-and-probabilistic-biological-risk-assessment-of-polycyclic-aromatic-hydrocarbons-pahs-along-gujarat-coastline
#14
Haren B Gosai, Bhumi K Sachaniya, Dushyant R Dudhagara, Rahul K Rajpara, Bharti P Dave
A comprehensive investigation was conducted in order to assess the levels of PAHs, their input prediction and potential risks to bacterial abundance and human health along Gujarat coastline. A total of 40 sediment samples were collected at quarterly intervals within a year from two contaminated sites-Alang-Sosiya Shipbreaking Yard (ASSBRY) and Navlakhi Port (NAV), situated at Gulf of Khambhat and Gulf of Kutch, respectively. The concentration of ΣPAHs ranged from 408.00 to 54240.45 ng g(-1) dw, indicating heavy pollution of PAHs at both the contaminated sites...
August 11, 2017: Environmental Geochemistry and Health
https://www.readbyqxmd.com/read/28801797/planar-covariance-of-upper-and-lower-limb-elevation-angles-during-hand-foot-crawling-in-healthy-young-adults
#15
M J MacLellan, G Catavitello, Y P Ivanenko, F Lacquaniti
Habitual quadrupeds have been shown to display a planar covariance of segment elevation angle waveforms in the fore and hind limbs during many forms of locomotion. The purpose of the current study was to determine if humans generate similar patterns in the upper and lower limbs during hand-foot crawling. Nine healthy young adults performed hand-foot crawling on a treadmill at speeds of 1, 2, and 3 km/h. A principal component analysis (PCA) was applied to the segment elevation angle waveforms for the upper (upper arm, lower arm, and hand) and lower (thigh, shank, and foot) limbs separately...
August 11, 2017: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
https://www.readbyqxmd.com/read/28801042/triacylglycerols-tags-in-edible-oils-determination-characterization-quantitation-chemometric-approach-and-evaluation-of-adulterations
#16
REVIEW
Serena Indelicato, David Bongiorno, Rosa Pitonzo, Vita Di Stefano, Valentina Calabrese, Sergio Indelicato, Giuseppe Avellone
Vegetable oils are a dietary source of lipids that constitute an essential component of a healthy diet. The commonly used vegetable oils differ significantly for their triacylglycerol (TAG) profile. TAGs represent the principal components of oils and may contain different fatty acids (FA) esterified with glycerol leading to several positional isomers. To differentiate individual TAGs species in edible oils, advanced analysis systems and innovative methods are therefore required. TAGs can be considered as good fingerprints for quality control and many studies have been performed to develop rapid and low cost analytical methods to determinate the authenticity, origin and eventually evidence frauds or adulterations...
August 2, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28800628/genome-wide-analysis-of-sotalol-induced-ikr-inhibition-during-ventricular-repolarization-generepol-study-lack-of-common-variants-with-large-effect-sizes
#17
Joe-Elie Salem, Marine Germain, Jean-Sébastien Hulot, Pascal Voiriot, Bruno Lebourgeois, Jean Waldura, David-Alexandre Tregouet, Beny Charbit, Christian Funck-Brentano
Many drugs used for non-cardiovascular and cardiovascular purposes, such as sotalol, have the side effect of prolonging cardiac repolarization, which can trigger life-threatening cardiac arrhythmias by inhibiting the potassium-channel IKr (KCNH2). On the electrocardiogram (ECG), IKr inhibition induces an increase in QTc and Tpeak-Tend (TpTe) interval and a decrease of T wave maximal amplitude (TAmp). These changes vary markedly between subjects, suggesting the existence of predisposing genetic factors. 990 healthy individuals, prospectively challenged with an oral 80mg sotalol dose, were monitored for changes in ventricular repolarization on ECG between baseline and 3 hours post dosing...
2017: PloS One
https://www.readbyqxmd.com/read/28800443/a-novel-approach-to-spinal-3-d-kinematic-assessment-using-inertial-sensors-towards-effective-quantitative-evaluation-of-low-back-pain-in-clinical-settings
#18
Sajad Ashouri, Mohsen Abedi, Masoud Abdollahi, Farideh Dehghan Manshadi, Mohamad Parnianpour, Kinda Khalaf
This paper presents a novel approach for evaluating LBP in various settings. The proposed system uses cost-effective inertial sensors, in conjunction with pattern recognition techniques, for identifying sensitive classifiers towards discriminate identification of LB patients. 24 healthy individuals and 28 low back pain patients performed trunk motion tasks in five different directions for validation. Four combinations of these motions were selected based on literature, and the corresponding kinematic data was collected...
August 4, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28800126/human-adenocarcinoma-cell-line-sensitivity-to-essential-oil-phytocomplexes-from-pistacia-species-a-multivariate-approach
#19
Alessandro Buriani, Stefano Fortinguerra, Vincenzo Sorrenti, Stefano Dall'Acqua, Gabbriella Innocenti, Monica Montopoli, Daniela Gabbia, Maria Carrara
Principal component analysis (PCA) multivariate analysis was applied to study the cytotoxic activity of essential oils from various species of the Pistacia genus on human tumor cell lines. In particular, the cytotoxic activity of essential oils obtained from P. lentiscus, P. lentiscus var. chia (mastic gum), P. terebinthus, P. vera, and P. integerrima, was screened on three human adenocarcinoma cell lines: MCF-7 (breast), 2008 (ovarian), and LoVo (colon). The results indicate that all the Pistacia phytocomplexes, with the exception of mastic gum oil, induce cytotoxic effects on one or more of the three cell lines...
August 11, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28799654/physicochemical-properties-and-extrusion-behaviour-of-selected-common-bean-varieties
#20
Hedwig Natabirwa, John H Muyonga, Dorothy Nakimbugwe, Mercy Lungaho
BACKGROUND: Extrusion processing offers the possibility of processing common beans industrially into highly nutritious and functional products. However, there is limited information on properties of extrudates from different beans varieties and their association with raw material characteristics and extrusion conditions. In this study, physicochemical properties of raw and extruded Bishaz, K131, NABE19, Roba1 and RWR2245 common beans were determined. The relationships between bean characteristics and extrusion conditions on the extrudate properties were analyzed...
August 11, 2017: Journal of the Science of Food and Agriculture
keyword
keyword
22537
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"