Projection to latent structures with orthogonal constraints for metabolomics data

2018 ◽  
Vol 32 (5) ◽  
pp. e2987 ◽  
Author(s):  
Matteo Stocchero ◽  
Samantha Riccadonna ◽  
Pietro Franceschi
Keyword(s):  
Metabolomics Data ◽  
Projection To Latent Structures ◽  
Latent Structures

scholarly journals Projection to latent structures with orthogonal constraints for metabolomics data

2018 ◽  
Vol 32 (5) ◽  
pp. e3047 ◽  
Author(s):  
Matteo Stocchero ◽  
Samantha Riccadonna ◽  
Pietro Franceschi
Keyword(s):  
Metabolomics Data ◽  
Projection To Latent Structures ◽  
Latent Structures

Determination of Pyridostigmine Bromide in Presence of its Related Impurities by Four Modified Classical Least Square Based Models: A Comparative Study

2020 ◽  
Vol 17 (1) ◽  
pp. 87-94
Author(s):  
Ibrahim A. Naguib ◽  
Fatma F. Abdallah ◽  
Aml A. Emam ◽  
Eglal A. Abdelaleem
Keyword(s):  
Comparative Study ◽  
Least Squares ◽  
Orthogonal Projection ◽  
Predictive Ability ◽  
Least Square ◽  
Projection To Latent Structures ◽  
Preprocessing Method ◽  
Spectral Residual ◽  
Latent Structures

: Quantitative determination of pyridostigmine bromide in the presence of its two related substances; impurity A and impurity B was considered as a case study to construct the comparison. Introduction: Novel manipulations of the well-known classical least squares multivariate calibration model were explained in detail as a comparative analytical study in this research work. In addition to the application of plain classical least squares model, two preprocessing steps were tried, where prior to modeling with classical least squares, first derivatization and orthogonal projection to latent structures were applied to produce two novel manipulations of the classical least square-based model. Moreover, spectral residual augmented classical least squares model is included in the present comparative study. Methods: 3 factor 4 level design was implemented constructing a training set of 16 mixtures with different concentrations of the studied components. To investigate the predictive ability of the studied models; a test set consisting of 9 mixtures was constructed. Results: The key performance indicator of this comparative study was the root mean square error of prediction for the independent test set mixtures, where it was found 1.367 when classical least squares applied with no preprocessing method, 1.352 when first derivative data was implemented, 0.2100 when orthogonal projection to latent structures preprocessing method was applied and 0.2747 when spectral residual augmented classical least squares was performed. Conclusion: Coupling of classical least squares model with orthogonal projection to latent structures preprocessing method produced significant improvement of the predictive ability of it.

scholarly journals Coronary Artery Calcification Is Related to Inflammation in Rheumatoid Arthritis: A Long-Term Follow-Up Study

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Bengt Wahlin ◽  
Thomas Meedt ◽  
Fredrik Jonsson ◽  
Michael Y. Henein ◽  
Solveig Wållberg-Jonsson
Keyword(s):  
Rheumatoid Arthritis ◽  
Coronary Artery ◽  
Coronary Artery Calcification ◽  
Intima Media Thickness ◽  
Projection To Latent Structures ◽  
Follow Up Study ◽  
Long Term Follow Up ◽  
Latent Structures

Objective. A long-term follow-up of patients with rheumatoid arthritis (RA) to evaluate factors related to coronary artery calcification (CAC).Methods. All 22 eligible patients (4 males/18 females, mean age 65 years, and RA-duration 30–36 years) from the original (baseline;n=39) study of atherosclerosis were included. Inflammation, cardiovascular risk factors, and biomarkers were measured at baseline. At follow-up 13 years later, CAC was assessed by computed tomography (CT) and the grade of inflammation was measured. Multivariate analysis of differences between patients with low (0–10) and high CAC (>10) was done by orthogonal projection to latent structures (OPLS).Results. Ten patients had CAC 0–10 and 12 had >10 (range 18–1700). Patients with high CAC had significantly higher ESR (24.3 versus 9.9 mm/h) and swollen joint count (2 versus 0). The OPLS models discriminated between patients having high or low CAC. With only baseline variables, the sensitivity was 73% and the specificity 82%. The model that also included inflammatory variables from follow-up had a sensitivity of 89% and a specificity of 85%. Exclusion of baseline intima media thickness and plaque from the latter model modestly reduced the accuracy (sensitivity 80% and specificity 83%).Conclusions. CAC is related to inflammation in patients with RA.

scholarly journals Inability to act was associated with an extended delay prior to care-seeking, in patients with an acute myocardial infarction

2019 ◽  
Vol 18 (6) ◽  
pp. 512-520 ◽  
Author(s):  
Carolin Nymark ◽  
Peter Henriksson ◽  
Anne-Cathrine Mattiasson ◽  
Fredrik Saboonchi ◽  
Anna Kiessling
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Medical Care ◽  
Patient Delay ◽  
Care Seeking ◽  
Projection To Latent Structures ◽  
Symptom Appraisal ◽  
Latent Structures ◽  
Appraisal Processes ◽  
Main Influence

Background:The out-of-hospital mortality in patients with acute myocardial infarction remains unchanged in contrast to a decrease in inhospital mortality. Interventions aiming to shorten patient delay have been largely unsuccessful. A deeper understanding is apparently needed on patients’ appraisal prior to care-seeking.Aim:To investigate whether appraisal processes influence patient delay, and if the questionnaire ‘Patients’ appraisal, emotions and action tendencies preceding care seeking in acute myocardial infarction’ (PA-AMI) could discriminate between patients with prolonged care-seeking and those with a short delay.Methods:A cross-sectional study including 326 acute myocardial infarction patients filling out the validated questionnaire PA-AMI. The impact of subscales on delay was analysed by projection to latent structures regression. Discrimination opportunities between patients with short and long delays were analysed by projection to latent structures discriminant analysis.Results:The subscales ‘perceived inability to act’ and ‘symptom appraisal’ had a major impact on patient delay ( P<0.0001). ‘Perceived inability to act’ had its main influence in patients with a delay exceeding 12 hours, and ‘symptom appraisal’ had its main influence in patients with a delay shorter than one hour.Conclusion:Appraisal processes influence patient delay. Acute myocardial infarction patients with a prolonged delay were, besides a low perceived symptom severity and urgency to seek medical care, characterised by a perceived loss of control and ability to act. Therefore, future interventions aimed at decreasing delay should pay attention to appraisal processes, and perceived inability to act may be a sign of a health threat and therefore a signal to seek medical care.

Improving Continuous Powder Blending Performance Using Projection to Latent Structures Regression

2013 ◽  
Vol 8 (2) ◽  
pp. 99-110 ◽  
Author(s):  
Yijie Gao ◽  
Fani Boukouvala ◽  
William Engisch ◽  
Wei Meng ◽  
Fernando J. Muzzio ◽  
...  
Keyword(s):  
Projection To Latent Structures ◽  
Powder Blending ◽  
Latent Structures ◽  
Continuous Powder Blending
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