keyword
MENU ▼
Read by QxMD icon Read
search

Principal components analysis

keyword
https://www.readbyqxmd.com/read/28214938/baseline-trace-metals-in-patella-caerulea-in-a-central-tyrrhenian-ecosystem-pontine-islands-archipelago-and-lazio-region-coastal-sites-italy
#1
Marcelo Enrique Conti, Giustino Mele, Maria Grazia Finoia
In this study, we tested the aptitude of the gastropod mollusk Patella caerulea as biomonitor of elemental pollution in seawater of a central Tyrrhenian ecosystem (Pontine Islands archipelago and Lazio region coastal sites, Italy). Concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were measured in 120 individuals collected in six strategic locations in two sampling campaigns during 2011 and 2012. Samples of surrounding seawater were also collected in the same sites and tested for the same metals in order to obtain the respective concentration factors (CFs)...
February 18, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28214617/demonstrating-construct-validity-of-the-american-board-of-physical-medicine-and-rehabilitation-part-i-examination-an-analysis-of-dimensionality
#2
Mikaela Raddatz, Lawrence R Robinson
BACKGROUND: Ideally, high stakes examinations assess one dimension of medical knowledge to produce precise estimates of a candidate's performance. It has not been reported whether the American Board of Physical Medicine and Rehabilitation Part 1 Certification Examination (ABPMR-CE-1) is unidimensional or not. OBJECTIVE: To examine the ABPMR-CE-1 to measure how many dimensions it assesses. DESIGN: Retrospective observational study. SETTING: We assessed examination results from the 2015 ABPMR-CE-1...
February 15, 2017: PM & R: the Journal of Injury, Function, and Rehabilitation
https://www.readbyqxmd.com/read/28213955/the-skin-barrier-function-gene-spink5-is-associated-with-challenge-proven-ige-mediated-food-allergy-in-infants
#3
Sarah E Ashley, Hern-Tze Tina Tan, Peter Vuillermin, Shyamali C Dharmage, Mimi L K Tang, Jennifer Koplin, Lyle C Gurrin, Adrian Lowe, Caroline Lodge, Anne-Louise Ponsonby, John Molloy, Pamela Martin, Melanie C Matheson, Richard Saffery, Katrina J Allen, Justine A Ellis, David Martino
BACKGROUND: A defective skin barrier is hypothesised to be an important route of sensitisation to dietary antigens, and may lead to food allergy in some children. Missense mutations in the Serine peptidase inhibitor kazal type 5 (SPINK5) skin barrier gene have previously been associated with allergic conditions. OBJECTIVE: To determine whether genetic variants in and around SPINK5 are associated with IgE mediated food allergy. METHOD: We genotyped 71 'tag' single nucleotide polymorphisms (tag-SNPs) within a region spanning ~263 kilobases (kb) including SPINK5 (~61kb) in n=722 (n=367 food allergic, n=199 food sensitised, tolerant and n=156 non-food allergic controls) 12-month infants (discovery sample) phenotyped for food allergy with the gold standard oral food challenge (OFC)...
February 18, 2017: Allergy
https://www.readbyqxmd.com/read/28213321/effects-of-selenium-lead-interaction-on-the-gene-expression-of-inflammatory-factors-and-selenoproteins-in-chicken-neutrophils
#4
Xiaojing Li, Mengyuan Xing, Menghao Chen, Jinxin Zhao, Ruifeng Fan, Xia Zhao, Changyu Cao, Jie Yang, Ziwei Zhang, Shiwen Xu
Lead (Pb) is one of the most highly toxic metal pollutant that can cause damage to the immune system. It is known that selenium (Se) can antagonize heavy metals. To explore the toxic effects of Pb poisoning on bird immune cells, as well as the alleviating effects of Se on Pb, Se supplement and/or Pb poisoning chicken models were established. One hundred and eighty Hyline 7-day-old male chickens received either Se (1mg Se per kg of diet), Pb (350mg Pb per liter water) or Se+Pb in their diet and water for 90 days...
February 14, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28213297/retention-of-silver-nano-particles-and-silver-ions-in-calcareous-soils-influence-of-soil-properties
#5
Samaneh Rahmatpour, Mehran Shirvani, Mohammad R Mosaddeghi, Mehdi Bazarganipour
The rapid production and application of silver nanoparticles (AgNPs) have led to significant release of AgNPs into the terrestrial environments. Once released into the soil, AgNPs could enter into different interactions with soil particles which play key roles in controlling the fate and transport of these nanoparticles. In spite of that, experimental studies on the retention of AgNPs in soils are very scarce. Hence, the key objective of this research was to find out the retention behavior of AgNPs and Ag(I) ions in a range of calcareous soils...
February 14, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28213278/identifying-overarching-excipient-properties-towards-an-in-depth-understanding-of-process-and-product-performance-for-continuous-twin-screw-wet-granulation
#6
N Willecke, A Szepes, M Wunderlich, J P Remon, C Vervaet, T De Beer
The overall objective of this work is to understand how excipient characteristics influence the process and product performance for a continuous twin-screw wet granulation process. The knowledge gained through this study is intended to be used for a Quality by Design (QbD)-based formulation design approach and formulation optimization. A total of 9 preferred fillers and 9 preferred binders were selected for this study. The selected fillers and binders were extensively characterized regarding their physico-chemical and solid state properties using 21 material characterization techniques...
February 14, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28213237/revealing-the-location-of-semen-vaginal-fluid-and-urine-in-stained-evidence-through-near-infrared-chemical-imaging
#7
Félix Zapata, Fernando E Ortega-Ojeda, Carmen García-Ruiz
Crime scene investigation (CSI) requires the ultimate available technology for a rapid, non-destructive, and accurate detection of a wide variety of evidence including invisible stains of bodily fluids. Particularly crucial is the discrimination of semen in stained evidence from sexual abuse cases. This is because those evidence have high odds of containing the DNA from the aggressor. To this aim, we demonstrated the potential of near infrared hyperspectral imaging (NIR-HSI) to make visible stains of semen, vaginal fluid, and urine on fabrics, which lays the bases to face the challenging visualization and discrimination of semen within bodily fluids mixtures...
May 1, 2017: Talanta
https://www.readbyqxmd.com/read/28213211/application-of-2d-hplc-coupled-with-principal-component-analysis-to-study-an-industrial-opiate-processing-stream
#8
Paul G Stevenson, Niki K Burns, Stuart D Purcell, Paul S Francis, Neil W Barnett, Fiona Fry, Xavier A Conlan
Principal component analysis (PCA) loading plots were used to elucidate key differences between two-dimensional high performance liquid chromatography (2D-HPLC) fingerprint data from samples collected from stages along the Papaver somniferum industrial process chemistry workflow. Data reduction was completed using a 2D-HPLC peak picking approach as a precursor to chemometric analysis. Using comparisons of the final stages of product extraction as an example, PCA analysis of characteristic 2D-HPLC fingerprints accounted for 84...
May 1, 2017: Talanta
https://www.readbyqxmd.com/read/28212461/fatty-acid-composition-of-baobab-seed-and-its-relationship-with-the-genus-adansonia-taxonomy
#9
Gaylor Razafimamonjison, Jean Michel Leong Pock Tsy, Manitriniaina Randriamiarinarivo, Panja Ramanoelina, Jean Rasoarahona, Fanjaniaina Fawbush, Pascal Danthu
Baobab seed oil contains specific fatty acids. Most of the studies on baobab fatty acids have been carried out singly and in isolation from each other, making it difficult to compare results through different species. The objective of the present study is to establish the seed fatty acid composition of each Adansonia species in order to evaluate and understand the relationships between the oil chemical compositions, the baobabs' taxonomy and, the ecological and geographical origin of each seed lot. The seed oils have been analysed using gas chromatography (GC)...
February 17, 2017: Chemistry & Biodiversity
https://www.readbyqxmd.com/read/28212095/identifying-bacterial-essential-genes-based-on-a-feature-integrated-method
#10
Yan Lin, Fa-Zhan Zhang, Kai Xue, Yi-Zhou Gao, Feng-Biao Guo
Essential genes are those genes of an organism that are considered to be crucial for its survival. Identification of essential genes is therefore of great significance to advance our understanding of the principles of cellular life. We have developed a novel computational method, which can effectively predict bacterial essential genes by extracting and integrating homologous features, protein domain feature, gene intrinsic features and network topological features. By performing the principal component regression (PCR) analysis for Escherichia coli MG1655, we established a classification model with the average area under curve (AUC) value of 0...
February 15, 2017: IEEE/ACM Transactions on Computational Biology and Bioinformatics
https://www.readbyqxmd.com/read/28211884/responses-of-spatial-temporal-dynamics-of-bacterioplankton-community-to-large-scale-reservoir-operation-a-case-study-in-the-three-gorges-reservoir-china
#11
Zhe Li, Lunhui Lu, Jinsong Guo, Jixiang Yang, Jiachao Zhang, Bin He, Linlin Xu
Large rivers are commonly regulated by damming, yet the effects of such disruption on bacterioplankton community structures have not been adequately studied. The aim of this study was to explore the biogeographical patterns present under dam regulation and to uncover the major drivers structuring bacterioplankton communities. Bacterioplankton assemblages in the Three Gorges Reservoir (TGR) were analyzed using Illumina Miseq sequencing by comparing seven sites located within the TGR before and after impoundment...
February 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28211833/an-anthropometric-study-of-serbian-metal-industry-workers
#12
S Omić, V K Spasojevic Brkić, T A Golubović, A Dj Brkić, M M Klarin
BACKGROUND: There are recent studies using new industrial workers' anthropometric data in different countries, but for Serbia such data are not available. OBJECTIVE: This study is the first anthropometric study of Serbian metal industry workers in the country, whose labor force is increasingly employed both on local and international markets. The metal industry is one of Serbia's most important economic sectors. METHODS: To this end, we collected the basic static anthropometric dimensions of 122 industrial workers and used principal components analysis (PCA) to obtain multivariate anthropometric models...
February 17, 2017: Work: a Journal of Prevention, Assessment, and Rehabilitation
https://www.readbyqxmd.com/read/28211085/variable-selection-in-the-functional-linear-concurrent-model
#13
Jeff Goldsmith, Joseph E Schwartz
We propose methods for variable selection in the context of modeling the association between a functional response and concurrently observed functional predictors. This data structure, and the need for such methods, is exemplified by our motivating example: a study in which blood pressure values are observed throughout the day, together with measurements of physical activity, location, posture, affect or mood, and other quantities that may influence blood pressure. We estimate the coefficients of the concurrent functional linear model using variational Bayes and jointly model residual correlation using functional principal components analysis...
February 17, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28209493/quantitative-analysis-of-fetal-facial-morphology-using-3d-ultrasound-and-statistical-shape-modelling-a-feasibility-study
#14
Andrea Dall'Asta, Silvia Schievano, Jan L Bruse, Gowrishankar Paramasivam, Christine Tita Kaihura, David Dunaway, Christoph C Lees
BACKGROUND: The antenatal detection of facial dysmorphism using three-dimensional ultrasound may raise the suspicion of an underlying genetic conditions but infrequently leads to a definitive antenatal diagnosis. Despite advances in array and non invasive prenatal testing, not all genetic conditions can be ascertained from such testing. OBJECTIVES: The aim of this study was to investigate the feasibility of quantitative assessment of fetal face features using prenatal three-dimensional ultrasound volumes and statistical shape modelling...
February 13, 2017: American Journal of Obstetrics and Gynecology
https://www.readbyqxmd.com/read/28209428/an-artificial-intelligence-based-improved-classification-of-two-phase-flow-patterns-with-feature-extracted-from-acquired-images
#15
C Shanthi, N Pappa
Flow pattern recognition is necessary to select design equations for finding operating details of the process and to perform computational simulations. Visual image processing can be used to automate the interpretation of patterns in two-phase flow. In this paper, an attempt has been made to improve the classification accuracy of the flow pattern of gas/ liquid two- phase flow using fuzzy logic and Support Vector Machine (SVM) with Principal Component Analysis (PCA). The videos of six different types of flow patterns namely, annular flow, bubble flow, churn flow, plug flow, slug flow and stratified flow are recorded for a period and converted to 2D images for processing...
February 13, 2017: ISA Transactions
https://www.readbyqxmd.com/read/28208113/ranking-the-factors-influencing-polycyclic-aromatic-hydrocarbons-pahs-build-up-on-urban-roads
#16
An Liu, Yukun Ma, Kaveh Deilami, Prasanna Egodawatta, Ashantha Goonetilleke
An in-depth understanding of polycyclic aromatic hydrocarbons (PAHs) build-up on urban roads is essential for effective stormwater treatment design. Past research studies have pointed out the relationship between influential factors and PAHs build-up individually. However, these studies do not provide a comprehensive analysis of the relationships and the hierarchy of factors in terms of their importance in influencing PAHs build-up. This paper presents the outcomes of an in-depth investigation into the range of influential factors, including traffic volume, land use, distance to highway and roughness of road surfaces by ranking them in terms of their influence on PAHs build-up...
February 13, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28207900/classification-and-identification-of-rhodobryum-roseum-limpr-and-its-adulterants-based-on-fourier-transform-infrared-spectroscopy-ftir-and-chemometrics
#17
Zhen Cao, Zhenjie Wang, Zhonglin Shang, Jiancheng Zhao
Fourier-transform infrared spectroscopy (FTIR) with the attenuated total reflectance technique was used to identify Rhodobryum roseum from its four adulterants. The FTIR spectra of six samples in the range from 4000 cm-1 to 600 cm-1 were obtained. The second-derivative transformation test was used to identify the small and nearby absorption peaks. A cluster analysis was performed to classify the spectra in a dendrogram based on the spectral similarity. Principal component analysis (PCA) was used to classify the species of six moss samples...
2017: PloS One
https://www.readbyqxmd.com/read/28207859/differential-effects-of-silencing-crustacean-hyperglycemic-hormone-gene-expression-on-the-metabolic-profiles-of-the-muscle-and-hepatopancreas-in-the-crayfish-procambarus-clarkii
#18
Wenfeng Li, Kuo-Hsun Chiu, Yi-Chun Tien, Shih-Fu Tsai, Li-Jane Shih, Chien-Hsun Lee, Jean-Yves Toullec, Chi-Ying Lee
In order to functionally characterize the metabolic roles of crustacean hyperglycemic hormone (CHH), gene expression of CHH in the crayfish (Procambarus clarkii) was knocked down by in vivo injection of CHH double-stranded RNA (dsRNA), followed by metabolomic analysis of 2 CHH target tissues (the muscle and hepatopancreas) using nuclear magnetic resonance spectroscopy. Compared to the levels in untreated and saline-injected (SAI) animals, levels of CHH transcript, but not those of molt-inhibiting hormone (a CHH-family peptide), in the eyestalk ganglia of CHH dsRNA-injected (DSI) animals were significantly decreased at 24, 48, and 72 hour post injection (hpi), with concomitant changes in levels of CHH peptide in the sinus gland (a neurohemal organ) and hemolymph...
2017: PloS One
https://www.readbyqxmd.com/read/28205533/a-data-driven-approach-for-evaluating-multi-modal-therapy-in-traumatic-brain-injury
#19
Jenny Haefeli, Adam R Ferguson, Deborah Bingham, Adrienne Orr, Seok Joon Won, Tina I Lam, Jian Shi, Sarah Hawley, Jialing Liu, Raymond A Swanson, Stephen M Massa
Combination therapies targeting multiple recovery mechanisms have the potential for additive or synergistic effects, but experimental design and analyses of multimodal therapeutic trials are challenging. To address this problem, we developed a data-driven approach to integrate and analyze raw source data from separate pre-clinical studies and evaluated interactions between four treatments following traumatic brain injury. Histologic and behavioral outcomes were measured in 202 rats treated with combinations of an anti-inflammatory agent (minocycline), a neurotrophic agent (LM11A-31), and physical therapy consisting of assisted exercise with or without botulinum toxin-induced limb constraint...
February 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28202815/covariation-in-levels-of-nucleotide-diversity-in-homologous-regions-of-the-avian-genome-long-after-completion-of-lineage-sorting
#20
Ludovic Dutoit, Nagarjun Vijay, Carina F Mugal, Christen M Bossu, Reto Burri, Jochen Wolf, Hans Ellegren
Closely related species may show similar levels of genetic diversity in homologous regions of the genome owing to shared ancestral variation still segregating in the extant species. However, after completion of lineage sorting, such covariation is not necessarily expected. On the other hand, if the processes that govern genetic diversity are conserved, diversity may potentially covary even among distantly related species. We mapped regions of conserved synteny between the genomes of two divergent bird species-collared flycatcher and hooded crow-and identified more than 600 Mb of homologous regions (66% of the genome)...
February 22, 2017: Proceedings. Biological Sciences
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"