Hjem
Olav Martin Kvalheims bilde

Olav Martin Kvalheim

Professor
  • E-postOlav.Kvalheim@uib.no
  • Telefon+47 55 58 33 66
  • Besøksadresse
    Realfagbygget, Allégt. 41
  • Postadresse
    Postboks 7803
    5020 BERGEN

I am mainly working with i) instrumental characterization/profiling of complex multicomponent systems (body fluids and tissue) and development of data-analytical methods and algorithms for resolution, exploration, pattern recognition, discrimination and classification of such systems, and, ii) applications of such methods to solve multifaceted problems of medical and pharmaceutical origin. Typically, spectral or chromatographic fingerprints of whole or fractionated samples are used to select features characterizing and/or discriminating groups of samples or to predict properties such as e.g. bioactivity of natural products or disease states for patients. Feature selection provides a strategy to reveal so-called biomarkers, molecules carrying specific information about biological processes such as pathogenesis. This can be molecules displaying the disease pattern in a way that can be utilized for diagnostic or therapeutic purposes. Collaboration with medical research groups is established in obesity research, and, for neurological diseases (multiple sclerosis). Analytical instrumentation such as NMR, chromatography and mass spectroscopy combined with chemometrics represents key technologies for pattern recognition and biomarker discovery for early diagnosis, risk analysis, and, monitoring of disease development and therapeutic effects.

Master and PhD projects are provided within the areas of new algortihms and methods for profiling and data analysis of complex systems, and, application of such methods to solve medical and pharmaceutical problems.

Examples of recent master theses:

1. Analysis of Brain Lipids Using NMR and Multivariate Methods

2. Multivariate characterization and analysis of brain lipids

Vitenskapelig artikkel
  • Vis forfatter(e) 2019. Opportunities and limitations for untargeted mass spectrometry metabolomics to identify biologically active constituents in complex natural product mixtures. Journal of natural products. 469-484.
  • Vis forfatter(e) 2019. Number of components and prediction error in partial least squares regression determined by Monte Carlo resampling strategies. Chemometrics and Intelligent Laboratory Systems. 79-86.
  • Vis forfatter(e) 2019. Interpretation of multivariate association patterns between multicollinear physical activity accelerometry data and cardiometabolic health in children-a tutorial. Metabolites. 14 sider.
  • Vis forfatter(e) 2019. Associations of physical activity and sedentary time with lipoprotein subclasses in Norwegian schoolchildren: The Active Smarter Kids (ASK) study. Atherosclerosis. 186-193.
  • Vis forfatter(e) 2018. The multivariate physical activity signature associated with metabolic health in children. International Journal of Behavioral Nutrition and Physical Activity.
  • Vis forfatter(e) 2018. Strong association between cardiorespiratory fitness and serum lipoprotein subclass pattern in prepubertal healthy children. Scandinavian Journal of Medicine & Science in Sports. 220-227.
  • Vis forfatter(e) 2018. Integration of Biochemometrics and Molecular Networking to Identify Antimicrobials in Angelica keiskei. Planta Medica. 721-728.
  • Vis forfatter(e) 2018. Hierarchical Cluster Analysis of Technical Replicates to Identify Interferents in Untargeted Mass Spectrometry Metabolomics. Analytica Chimica Acta. 69-77.
  • Vis forfatter(e) 2018. Determination of optimum number of components in partial least squares regression from distributions of the root‐mean‐squared error obtained by Monte Carlo resampling. Journal of Chemometrics. 1-12.
  • Vis forfatter(e) 2018. Biochemometrics to Identify Synergists and Additives from Botanical Medicines: A Case Study with Hydrastis canadensis (Goldenseal). Journal of natural products. 484-493.
  • Vis forfatter(e) 2017. Aerobic fitness and metabolic health in children: A clinical validation of directly measured maximal oxygen consumption versus performance measures as markers of health. Preventive Medicine Reports. 74-76.
  • Vis forfatter(e) 2016. Serum fatty acid and lipoprotein subclass concentrations and their associations in prepubertal healthy Norwegian children. Metabolomics.
  • Vis forfatter(e) 2016. Predictive associations between serum fatty acids and lipoproteins in healthy non-obese Norwegians: implications for cardiovascular health. Metabolomics.
  • Vis forfatter(e) 2016. Intensive lifestyle intervention provides rapid reduction of serum fatty acid levels in women with severe obesity without lowering omega-3 to unhealthy levels. Clinical Obesity. 259-267.
  • Vis forfatter(e) 2016. Biochemometrics for Natural Products Research: Comparison of Data Analysis Approaches and Application to Identification of Bioactive Compounds. Journal of natural products. 376-386.
  • Vis forfatter(e) 2015. Moffat-swern oxidation of alcohols: Translating a batch reaction to a continuous-flow reaction. Journal of Flow Chemistry. 183-189.
  • Vis forfatter(e) 2015. Changes in Serum Fatty Acid Levels During the First Year After Bariatric Surgery. Obesity Surgery.
  • Vis forfatter(e) 2015. Active Smarter Kids (ASK): Rationale and design of a cluster-randomized controlled trial investigating the effects of daily physical activity on children's academic performance and risk factors for non-communicable diseases. BMC Public Health.
  • Vis forfatter(e) 2014. Variable importance in latent variable regression models. Journal of Chemometrics. 615-622.
  • Vis forfatter(e) 2013. Physical activity versus sedentary behavior: associations with lipoprotein particle subclass concentrations in healthy adults. PLOS ONE. 9 sider.
  • Vis forfatter(e) 2013. Investigation of serum protein profiles in scrapie infected sheep by means of SELDI-TOF-MS and multivariate data analysis. BMC Research Notes. 14 sider.
  • Vis forfatter(e) 2013. Impact of physical activity and diet on lipoprotein particle concentrations in severely obese women participating in a 1-year lifestyle intervention. Clinical Obesity. 202-213.
  • Vis forfatter(e) 2012. History, philosophy and mathematical basis of the latent variable approach - from a peculiarity in psychology to a general method for analysis of multivariate data. Journal of Chemometrics. 210-217.
  • Vis forfatter(e) 2011. Resolving co-eluting chromatographic patterns by means of dissimilarity analysis in iterative target transformation factor analysis. Journal of Chromatography A. 7219-7225.
  • Vis forfatter(e) 2011. Chromatographic profiling and multivariate analysis for screening and quantifying the contributions from individual components to the bioactive signature in natural products. Chemometrics and Intelligent Laboratory Systems. 98-105.
  • Vis forfatter(e) 2010. The vector of calibration ratios: A simple transfer method for mass spectra. Journal of Chromatography A. 5986-5994.
  • Vis forfatter(e) 2010. Interpretation of partial least squares regression models by means of target projection and selectivity ratio plots. Journal of Chemometrics. 9 sider.
  • Vis forfatter(e) 2010. Detection and use of selective ions for providing initial estimates of the concentration vectors in iterative target transformation factor analysis. Journal of Chromatography A. 3128-3135.
  • Vis forfatter(e) 2010. A multivariate approach to reveal biomarker signatures for disease classification: application to mass spectral profiles of cerebrospinal fluid from patients with multiple sclerosis. Journal of Proteome Research. 3608-3620.
  • Vis forfatter(e) 2009. X-tended target projection (XTP) - comparison with orthogonal partial least squares (OPLS) and PLS post-processing by similarity transformation (PLS + ST). Journal of Chemometrics. 49-55.
  • Vis forfatter(e) 2009. Recipe for Uncovering the Bioactive Components in Herbal Medicine. Analytical Chemistry. 7217-7225.
  • Vis forfatter(e) 2009. Discriminating Variable Test and Selectivity Ratio Plot: Quantitative Tools for Interpretation and Variable (Biomarker) Selection in Complex Spectral or Chromatographic Profiles. Analytical Chemistry. 2581-2590.
  • Vis forfatter(e) 2009. Biomarker discovery in mass spectral profiles by means of selectivity ratio plot. Chemometrics and Intelligent Laboratory Systems. 35-48.
  • Vis forfatter(e) 2008. Uncorrelated linear discriminant analysis (ULDA): A powerful tool for exploration of metabolomics data. Chemometrics and Intelligent Laboratory Systems. 70-79.
  • Vis forfatter(e) 2008. Modeling based on subspace orthogonal projections for QSAR and QSPR research. Journal of Chemometrics. 23-36.
  • Vis forfatter(e) 2007. Quantifying disturbances in benthic communities - comparison of the community disturbance index (CDI) to other multivariate methods. Ecological Indicators. 254-276.
  • Vis forfatter(e) 2007. Pretreatment of mass spectral profiles: Application to proteomic data. Analytical Chemistry. 7014-7026.
  • Vis forfatter(e) 2007. Pre-analytical influence on the low molecular weight cerebrospinal fluid proteome. PROTEOMICS - Clinical Applications. 699-711.
  • Vis forfatter(e) 2007. A comparison of different pre-treatment procedures for reducing heteroscedasticity and other irrelevant features in data prior to modelling of benthic count profiles. Journal of Chemometrics. 386-396.
  • Vis forfatter(e) 2004. Toxicological evaluation of complex mixtures: fingerprinting and multivariate analysis. Environmental Toxicology and Pharmacology. 127-133.
  • Vis forfatter(e) 2004. Quantification of pollution levels by multiway modelling. Journal of Chemometrics. 173-182.
  • Vis forfatter(e) 2004. Quantification of pollution levels by multiway modelling. Journal of Chemometrics. 173-182.
  • Vis forfatter(e) 2004. Assigning environmental variables to observed biological changes. Analytical and Bioanalytical Chemistry. 453-466.
  • Vis forfatter(e) 2004. A method for validation of reference sets in SIMCA modelling. Chemometrics and Intelligent Laboratory Systems. 101-109.
  • Vis forfatter(e) 2004. A method for validation of reference sets in SIMCA modelling. Chemometrics and Intelligent Laboratory Systems. 101-109.
  • Vis forfatter(e) 2003. Screening of biomakers in rat urine using LC/MC electrospray ionization-MS and two-way data analysis. Analytical Chemistry. 4784-4792.
  • Vis forfatter(e) 2002. Toxicological evaluation of complex mixtures by pattern recognition: Correlating chemical fingerprints to mutagenicity. Environmental Health Perspectives. 985-988.
  • Vis forfatter(e) 2002. Study of the Self-Association of Alcohols by Near-Infrared Spectroscopy and Multivariate 2D Techniques. Journal of Physical Chemistry A. 8543-8553.
  • Vis forfatter(e) 2002. Feasibility study of NIR for surveillance of a pharmaceutical process, including a study of different preprocessing techniques. Journal of Chemometrics. 529-541.
  • Vis forfatter(e) 2001. Resolution of GC-MS Data of Complex PAC Mixtures and Regression Modeling of Mutagenicity by PLS. Environmental Science and Technology. 2314-2318.
  • Vis forfatter(e) 2001. Interactions in chromatographic separation of resins from deasphaltened crude oils studied by means of infrared spectroscopy and principal component analysis. Fuel. 717-730.
  • Vis forfatter(e) 2001. Automated curve resolution applied to data from multi-detection instruments. Analytica Chimica Acta. 313-328.
  • Vis forfatter(e) 2000. Quantitative determination of asphaltenes and resins in solution by means of near-infrared spectroscopy. Correlations to emulsion stability. Journal of Colloid and Interface Science. 494-504.
  • Vis forfatter(e) 2000. Multivarite screening analysis of water-in-oil emulsions in high external electric fields as studied by means of dielectric time domain spectroscopy - III emulsions containing asphaltenes and resins. Journal of Colloid and Interface Science. 262-271.
  • Vis forfatter(e) 2000. Morphological score and its application to chemical rank determination. Chemometrics and Intelligent Laboratory Systems. 37-47.
  • Vis forfatter(e) 2000. Determination of chemical rank of two-way data from subspace comparisons. Chemometrics and Intelligent Laboratory Systems. 49-59.
  • Vis forfatter(e) 2000. Crude oil model emulsion characterised by means of near infrared spectroscopy and multivariate techniques. Journal of Dispersion Science and Technology. 245-262.
  • Vis forfatter(e) 1998. Friedel-Crafts Acylation on Porous Divinyl Benzene Polymer Particles: A Reaction Kinetic Process Studied by Mid-and Near-Infrared spectroscopy. Applied Spectroscopy. 1230-1239.
  • Vis forfatter(e) 1997. Complexation between benzoic acid and fatty amines. An adsorption and chemometric study. Colloids and Surfaces. 135-144.
  • Vis forfatter(e) 1997. Associative bahaviour of benzyl alcohol in carbon tetrachloride solutions. Journal of Physical Chemistry A. 6960-6969.
  • Vis forfatter(e) 1997. Associative Behavior of Benzyl Alcohol in Carbon Tetrachloride Solutions. Journal of Physical Chemistry. 6960-6969.
  • Vis forfatter(e) 1996. Self-Association of Medium-Chain Alcohols in n-Decane Solutions. Applied Spectroscopy. 1264-1272.
  • Vis forfatter(e) 1996. Resolution of infrared profiles from variable temperature experiments on mixtures and conformers in rapid equilibrum by compensating for thermal and solvent effects. Vibrational Spectroscopy. 163-176.
  • Vis forfatter(e) 1996. Proton nuclear magnetic resonance spectroscopy of serum from patients with colorectal neoplasia. European Journal of Surgical Oncology. 78-83.
  • Vis forfatter(e) 1996. Proton nuclear magnetic resonance spectroscopy of serum from patients with colorectal neoplasia. European Journal of Surgical Oncology. 78-83.
  • Vis forfatter(e) 1996. Proton nuclear magnetic resonance spectroscopy of serum from patients with colorectal neoplasia. European Journal of Surgical Oncology. 78-83.
  • Vis forfatter(e) 1996. Proton nuclear magnetic resonance spectroscopy of serum from patients with colorectal neoplasia. European Journal of Surgical Oncology. 78-83.
  • Vis forfatter(e) 1996. Projective modelling by SIMCA - a new dynamic strategy for cost-efficient environmental monitoring around offshore installations. Aquatic Sciences. 120-138.
  • Vis forfatter(e) 1996. Methods for multivariate analysis. Chemometrics and Intelligent Laboratory Systems. 1-10.
  • Vis forfatter(e) 1996. Influence and correction of peak shift and band broadening observed by rank analysis on vibrational bands from variable-temperature measurement. Vibrational Spectroscopy. 105-123.
  • Vis forfatter(e) 1996. A multivariate analysis of w/o emulsions in high external electric fields, as studied by means of dielectric time domain spectroscopy. Part II. Model emulsions stabilised by interfacially active fractions from crude oils. Journal of Colloid and Interface Science. 396-405.
  • Vis forfatter(e) 1996. A multivariate analysis of w/o emulsions in high external electric fields, as studied by means of dielectric time domain spectroscopy. Journal of Colloid and Interface Science. 117-125.
  • Vis forfatter(e) 1995. Particle size effect on diffuse reflectance spectra: Modification of Kubelka-Munk equation. Vibrational Spectroscopy. 19-27.
  • Vis forfatter(e) 1995. Maturity trends in asphaltenes from pyrolysed source rocks and natural coals-Multivariate modelling of diffuse reflectance Fourier transform infrared spectra. Organic Geochemistry. 139-158.
  • Vis forfatter(e) 1995. Determination of the equilibrium constant and resolution of the HOD spectrum by alternating least squares. Applied Spectroscopy. 561-568.
  • Vis forfatter(e) 1994. Structure of liquid water determined from infrared temperature profiling and evolutionary curve resolution. Journal of the American Chemical Society. 8311-8316.
  • Vis forfatter(e) 1994. Speed improvement of multivariate algorithms by the method of postponed basis matrix multiplication method. Part II. Three-mode principal component analysis. Chemometrics and Intelligent Laboratory Systems. 43-54.
  • Vis forfatter(e) 1994. Speed improvement of multivariate algorithms by the method of postponed basis matrix multiplication method. Part 1. Principal component analysis. Chemometrics and Intelligent Laboratory Systems. 31-42.
  • Vis forfatter(e) 1994. Spectra of water in the near- and mid-infrared region. Vibrational Spectroscopy. 243-254.
  • Vis forfatter(e) 1994. Resolution of infrared spectra and kinetic analysis of mutarotation of D-Glucose in water by sequential rank analysis. Vibrational Spectroscopy. 139-148.
  • Vis forfatter(e) 1994. Resolution of embedded chromatographic peaks by sequential rank analysis of the firs-order differentiated elution profile in the domiain. Chemometrics and Intelligent Laboratory Systems. 229-240.
  • Vis forfatter(e) 1994. Rank determination of spectroscopi data by means of cross validation - The effect of replicated measurements on the degrees of fredom. Chemometrics and Intelligent Laboratory Systems. 115-125.
  • Vis forfatter(e) 1994. Preprocessing of analytical profiles in the presence of homoscedastic or heteroscedastic noise. Analytical Chemistry. 43-51.
  • Vis forfatter(e) 1994. Prediction of the Shannon Wiener index from trace element profiles in sediments around the Statfjord platforms. Chemosphere. 1441-1465.
  • Vis forfatter(e) 1994. Nonlinear curve fitting of bilinear data by ortogonal projections for rank analysis. Applications to GC-IR and temperature IR studies. Vibrational Spectroscopy. 125-137.
  • Vis forfatter(e) 1994. Non-linear curvefitting of bilinear data using orthogonal projections for rank analysis. Applications to gas chromatography/ infrared spectrometry and variable temperature infrared studies. Vibrational Spectroscopy. 125-137.
  • Vis forfatter(e) 1994. Non-linear curvefitting of bilinear data using orthogonal projections for rank analysis. Applications to gas chromatography/ infrared spectrometry and variable temperature infrared studies. Vibrational Spectroscopy. 125-137.
  • Vis forfatter(e) 1994. Multi-array resolution parameter for multidetection chromatography. Performance of alternating regression, iterative target transformation factor analysis and heuristic evolving latent projections. Chemometrics and Intelligent Laboratory Systems. 61-75.
  • Vis forfatter(e) 1994. Investigation of the allomerization reaction of chlorophyll a: use of diode array HPLC, mass spectrometry and chemometric factor analysis for the detection of early products. Photochemistry and Photobiology. 99-110.
  • Vis forfatter(e) 1994. Diagnosis and resolution of multiwavelength chromatograms by rank map, orthogonal projections and sequential rank analysis. Analytica Chimica Acta. 5-15.
  • Vis forfatter(e) 1994. Determination of kinetic parameters for the dehydration of calcium oxalate monohydrate by diffuse reflectance infrared FT-IR spectroscopy. Applied Spectroscopy. 561-568.
  • Vis forfatter(e) 1994. Compression of three-mode data arrays by B-splines prior to three-mode principal component analysis (PCA). Chemometrics and Intelligent Laboratory Systems. 29-38.
  • Vis forfatter(e) 1994. Compression of an order data arrays by B-splines. Part 2. Application to second- order FT-IR data. Journal of Chemometrics. 127-145.
  • Vis forfatter(e) 1994. Bulk compositional variations of coal asphaltenes studied by latent variable analysis of infrared microspectroscopic data. Chemometrics and Intelligent Laboratory Systems. 197-204.
  • Vis forfatter(e) 1994. Assessment of peak origin and purity by orthogonal design and Heuristic evolving latent projections. Journal of Chromatography A. 113-122.
  • Vis forfatter(e) 1993. White, grey and black - A classification of methods for quantitative analysis of multicomponent analytical systems. Chemometrics and Intelligent Laboratory Systems. 235-250.
  • Vis forfatter(e) 1993. Use of chemometrics factor analysis for chromatographic integration: Application to diode-array high-performance liquid chroma tography of mixtures of chlorophyll a degradation products. The Analyst. 779-790.
  • Vis forfatter(e) 1993. Unique resolution of hidden peaks in multidetection chromatography by first-order differentiation and orthogonal projectio ns. Analytica Chimica Acta. 425-440.
  • Vis forfatter(e) 1993. Resolution parameter for multidetection chromatography. Analytical Chemistry. 2270-2275.
  • Vis forfatter(e) 1993. Resolution of strongly overlapping two-way multicomponent data by means of Heuristic Evolving Latent Projections. Journal of Chemometrics. 15-43.
  • Vis forfatter(e) 1993. Interpretation of chemical structural changes by target-projection analysis of infrared profiles. Vibrational Spectroscopy. 1-14.
  • Vis forfatter(e) 1993. Heuristic evolving latent projections: Resolving hyphenated chromatographic profiles by component stripping. Chemometrics and Intelligent Laboratory Systems. 115-125.
  • Vis forfatter(e) 1993. Eigenstructure tracking analysis for demonstration of heteroscedastic noise in instrumental profiles - application to transm ittance and aborbance IR. Chemometrics and Intelligent Laboratory Systems. 65-73.
  • Vis forfatter(e) 1993. Effect of particle size on diffuse reflectance Fourier-transform infrared spectra of polystyrene spheres. Vibrational Spectroscopy. 233-244.
  • Vis forfatter(e) 1993. Determination of detection limit and local chemical rank by designing a nonparametric test from the zero-component regions. Journal of Chemometrics. 277-289.
  • Vis forfatter(e) 1993. Deconvolution in one-dimensional chromomatography by heuristic evolving latent projections of whole profiles retention time shifted b y Simplex optimization of cross correlation between target peaks. Analytica Chimica Acta. 101-114.
  • Vis forfatter(e) 1993. Compression of n-order data arrays by B-splines. Part 1. Theory. KJ. Chemometrics. 61-73.
  • Vis forfatter(e) 1993. A two-way procedure for background correction of chromatographic/spectroscopic data by means of congruence analysis and least-squares fit of the zero-component regions, comparison with double-centering. Chemometrics and Intelligent Laboratory Systems. 265-279.
  • Vis forfatter(e) 1993. A gas cell for on-line transmission Fourier-transform infrared spectrometry. Vibrational Spectroscopy. 365-371.
  • Vis forfatter(e) 1992. White, grey and black - A classification of methods for quantitative and qualitative analysis of multicomponent analytical systems. Chemometrics and Intelligent Laboratory Systems.
  • Vis forfatter(e) 1992. The latent variable. Chemometrics and Intelligent Laboratory Systems. 1-3.
  • Vis forfatter(e) 1992. Resolution of strongly overlapping two-way multicomponent data by means of Heuristic Evolving Latent Projections. Journal of Chemometrics.
  • Vis forfatter(e) 1992. On-line pyrolysis of asphaltenes studied by Diffuse reflectance Fourier transform infrared spectroscopy. Fuel. 125-127.
  • Vis forfatter(e) 1992. Laboratory Profile. Journal of Chemometrics. 113-116.
  • Vis forfatter(e) 1992. Investigation of the allomerization reaction of chlorophylla: use of diode array HPLC, mass spectrometry and chemometrics factor analysis for the detection of early products. Photochem.
  • Vis forfatter(e) 1992. Investigation of the allomerization reaction of chlorophylla: use of diode array HPLC, mass spectrometry and chemometrics factor analysis for the detection of early products. Photobiol.
  • Vis forfatter(e) 1992. Heuristic Evolving Latent Projection - resolving two-way multicomponent data. Part 2. Detection and resolution of minor component. Analytical Chemistry. 946-953.
  • Vis forfatter(e) 1992. Heuristic Evolving Latent Projection - resolving two-way multicomponent data. Part 1. Selectivity, latent-projective graph, datascope, local rank analysis and unique resolution. Analytical Chemistry. 936-946.
  • Vis forfatter(e) 1992. Evolving factor analysis in the presence of heteroscedastic noise. Analytica Chimica Acta. 29-36.
  • Vis forfatter(e) 1992. Estimation of prediction error for samples within the calibration range. Journal of Chemometrics. 177-188.
  • Vis forfatter(e) 1992. Eigenstructure tracking analysis for demonstration of heteroscedastic noise in instrumental profiles - application to transmittance and oborbance IR. Chemometrics and Intelligent Laboratory Systems.
  • Vis forfatter(e) 1992. Effect of particle size on diffuse reflectance infrared spectra of polysterene spheres. Vibrational Spectroscopy.
  • Vis forfatter(e) 1992. Deconvolution in one-dimensional chromotography by heuristic evolving latent projections of whole profiles retention time shifted by Simplex optimization of cross correlation between target peaks. Analytica Chimica Acta.
  • Vis forfatter(e) 1992. Constrained background bilinearization. Chemometrics and Intelligent Laboratory Systems. 175-184.
  • Vis forfatter(e) 1992. Compression of n-order data arrays by B-plines. Part. theory. Journal of Chemometrics.
  • Vis forfatter(e) 1992. Applications of diffuse reflectance Fourier-transform infrared spectroscopy in petroleum geochemistry. Scan Time, Spectra-Tech.
  • Vis forfatter(e) 1992. Applications of diffuse reflectance Fourier-transform infrared spectroscopy in petroleum geochemistry. Scan Time.
  • Vis forfatter(e) 1992. Applications of diffuse reflectance Fourier transform infrared spectroscopy in petroleum geochemistry. Spectra-Tech.
  • Vis forfatter(e) 1992. Analysis of nontransparent polymers-mixture design, 2nd derivative attenuated total internal reflectance FT-IR and multivariate calibration. Applied Spectroscopy. 1002-1008.
  • Vis forfatter(e) 1992. Analysis of non transparent polymers: Mixture design, 2nd derivate attenuated total internal reflectance FT-IR and multivariate calibration. Applied Spectroscopy. 1002-1008.
  • Vis forfatter(e) 1992. A two-way procedure for background correction of chromatographic/ spectroscopic data by means of congruence analysis and least-squares fit of the zerocomponent regions, comparison with double-centering. Chemometrics and Intelligent Laboratory Systems.
  • Vis forfatter(e) 1992. A comparison of the Heuristic envolving latent projection and evolving factor analysis methods for peak purity control in HPLCDAD. Analytica Chimica Acta. 63-71.
  • Vis forfatter(e) 1991. On-Line pyrolysis of asphaltenes studied by Diffuse reflectance Fourier-transform infrared spectroscopy. Fuel. 125-127.
  • Vis forfatter(e) 1991. Maturity of Kerogen and asphaltenes determined by Partial-Least -Squares (PLS) calibration and target projection of diffuse reflectance Fourier-transformed infrared spectra. Organic Geochemistry. 63-74.
  • Vis forfatter(e) 1991. Diffuse reflectance Fourier-transformed infrared spectroscopy in petroleum exploration: A multivariate approach to maturity determination. Journal of Geochemical Exploration. 213-226.
  • Vis forfatter(e) 1990. Detection of malignant tumors by multivariate analysis of proton magnetic resonance spectra of serum. European Journal of Cancer. 615-618.
  • Vis forfatter(e) 1989. Structural features of resins, asphaltenes and kerogen studied by diffuse reflectance Fourier-transform infrared spectroscopy. Fuel. 429-435.
  • Vis forfatter(e) 1989. Quantitative determination of thermal maturity in sedimentary organic matter by diffuse reflectance infrared spectroscopy of asphaltenes. Organic Geochemistry. 77-81.
  • Vis forfatter(e) 1987. Multivariate calibration of diffuse reflectance Fourier-transform infrared spectra of coals as an alternative to rank determination by vitrinite reflectance. Chemometrics and Intelligent Laboratory Systems. 199-207.
  • Vis forfatter(e) 1987. Maturity determination of organic matter in coals using the methyl phenanthrene distribution. Geochimica et Cosmochimica Acta. 1883-1888.
  • Vis forfatter(e) 1987. Interpretation of multivariate data: Relationship between phenanthrenes in crude oils. Chemometrics and Intelligent Laboratory Systems. 149-153.
Vitenskapelig foredrag
  • Vis forfatter(e) 2019. What is the best measure(s) of variable importance for interpretation and variable selection in multivariate regression models?
  • Vis forfatter(e) 2019. Using chromatography and chemometrics for detecting bioactive components in very complex extracts of natural products.
  • Vis forfatter(e) 2019. Optimal partial least squares models and predictions of properties using Monte Carlo resampling strategies.
  • Vis forfatter(e) 2019. Optimal Partial Least Squares models and predictions of properties using Monte Carlo resampling strategies.
  • Vis forfatter(e) 2018. Development and maintenance of process models - automating the selection and updating of models.
  • Vis forfatter(e) 2018. Bruk av kjemometri til persontilpasset forebygging av livsstilssykdommer.
  • Vis forfatter(e) 2017. Variable selection in process modeling.
  • Vis forfatter(e) 2017. Selecting the “right” variables in latent variable regression (LVR) modelling in the presence of multicolinearity and orthogonal variation - optimal interpretation and prediction at the same time .
  • Vis forfatter(e) 2017. Revealing the bioactive signature in multicomponent profiles.
  • Vis forfatter(e) 2017. Monte Carlo Cross validation for component selection and determination of prediction error in latent-variable regression.
  • Vis forfatter(e) 2017. Determination of optimum number of components in partial least squares regression.
  • Vis forfatter(e) 2016. Which factors impact the lipid metabolism and how?
  • Vis forfatter(e) 2016. Analysis of metabolomics data – examples from the study of the lipid metabolism.
  • Vis forfatter(e) 2015. Predictive and orthogonal variation in latent variable regression and implications for the concept of model quality and model reduction.
  • Vis forfatter(e) 2015. Chemometric-directed bioexploration of natural products.
  • Vis forfatter(e) 2014. Variable importance and variable selection in spectral profiles from process analysers.
  • Vis forfatter(e) 2014. Predictive and orthogonal variation in latent variable regression – model quality and model reduction .
  • Vis forfatter(e) 2014. Optimal strategies and tools for interpretation and variable selection in spectral profiles from process analysers .
  • Vis forfatter(e) 2014. Optimal strategies and tools for interpretation and variable selection in spectral profiles from process analysers.
  • Vis forfatter(e) 2014. Model performance, interpretation, prediction performance and SOLV-DPM for process control.
  • Vis forfatter(e) 2013. Relationship between physical activity and lipoprotein subclass changes in severely obese women.
  • Vis forfatter(e) 2007. Target projection and proper data pre-treatment for the analysis of proteomic profiles.
  • Vis forfatter(e) 2007. Preteatment of Mass Spectral Profiles: Application to proteomic data.
  • Vis forfatter(e) 2007. Analysis of Proteomic Profiles: Pretreatment and Biomarker Discovery for early diagnosis of diseases.
  • Vis forfatter(e) 2007. Analysis of Proteomic Profiles - Biomarker Discovery and Early Diagnosis.
  • Vis forfatter(e) 2007. Analysis of Proteomic Profiles.
  • Vis forfatter(e) 2003. Resolution of GC-MS and LC-MS profiles of very complex biomedical samples.
  • Vis forfatter(e) 2003. Medical application of GC- and LC- MS and MS resolver.
  • Vis forfatter(e) 2003. Introduction to design, Design of Experiments.
  • Vis forfatter(e) 2003. Introduction of NOx-handling (pre & post, existing context, R&D, where are we today?) Handling of NOx in exhaust gases.
  • Vis forfatter(e) 2001. Identification of and solution to the problem of lurking variables in industrial processes.
  • Vis forfatter(e) 1997. The associative behaviour of benzyl alcohol in carbon tetrachloride solutions.
  • Vis forfatter(e) 1997. PVA and related methods applied to improvement of industrial processes and product quality.
  • Vis forfatter(e) 1997. Multivariate information extraction as a strategic and communication tool in the industrial enterprise.
  • Vis forfatter(e) 1997. Kjemometri og kvalitet processes and product quality.
  • Vis forfatter(e) 1997. Environmental monitoring and forecasting by means of multivariate methods.
  • Vis forfatter(e) 1997. En innføring i multikomponentanalyse.
  • Vis forfatter(e) 1997. Detection and resolution of overlapping peaks in multidetection chromatography.
  • Vis forfatter(e) 1997. Chemometrics - advanced methods.
  • Vis forfatter(e) 1997. 2-D multicomponent analysis by means of Extricator.
  • Vis forfatter(e) 1993. Temperature dependency of the infrared spectra of water studied by Fourier-transform infrared spectroscopy.
  • Vis forfatter(e) 1993. Particle size problem in diffuse reflectance spectrometry.
  • Vis forfatter(e) 1993. Particle size problem in diffuse reflectance Fourier-transform infrared spectrometry. Plenary lecture.
  • Vis forfatter(e) 1992. Multivariate analysis of infrared spectroscopic data: Application to the chemical transformation of sedimentary organic matter.
  • Vis forfatter(e) 1992. Determination of activation energy for the thermal decomposition of kerogen by on-line pyrolysis infrared spectroscopy.
  • Vis forfatter(e) 1992. Applications of chemometrics in infrared microspectroscopy.
Sammendrag/abstract
  • Vis forfatter(e) 2018. The multivariate physical activity signature associated with metabolic health in children. Journal of Physical Activity and Health. 248-249.
  • Vis forfatter(e) 2018. Lipoprotein subclasses and their associations with physical activity and sedentary time in Norwegian schoolchildren: The Active Smarter Kids study. Journal of Physical Activity and Health. 109-110.
  • Vis forfatter(e) 2018. Associations for volumes and patterns of physical activity with metabolic health in children: a multivariate pattern analysis approach. Preventive Medicine.
  • Vis forfatter(e) 2017. Strong association between cardiorespiratory fitness and serum lipoprotein subclass pattern in prepubertal healthy children. Medicine & Science in Sports & Exercise. 640-640.
  • Vis forfatter(e) 2016. New strategies to identify synergists from Hydrastis canadensis (goldenseal). Planta Medica. 1 sider.
  • Vis forfatter(e) 2016. Biochemometric analysis reveals complimentary bacterial inhibitory functionalities of the medicinal lichen Usnea barbata. Planta Medica. 1 sider.
  • Vis forfatter(e) 2014. Effect of two types of bariatric surgery on the fatty acid profile in serum. The Complexity of obesity proceedings.
  • Vis forfatter(e) 2014. A multivariate approach to reveal biomarker signatures in instrumental profiles of body fluids. The Complexity of obesity proceedings.
  • Vis forfatter(e) 2011. Health Related Quality of Life in in-patients undergoing lifestyle treatment for morbid obesity. Obesity Reviews. 87-87.
  • Vis forfatter(e) 2008. PAT - Optimal prediction of properties by means of tailormade modelling of spectroscopic/chromatographic profiles. European Journal of Pharmaceutical Sciences. S16-S16.
  • Vis forfatter(e) 2008. Early diagnosis and biomarker discovery from mass spectral profiles: application to multiple sclerosis. Multiple Sclerosis. S285-S285.
  • Vis forfatter(e) 2008. Biomarker discovery from mass spectral profiles: A combined proteomics and multivariate analysis. European Journal of Pharmaceutical Sciences. S27-S27.
Vitenskapelig oversiktsartikkel/review
  • Vis forfatter(e) 2011. Multivariate data analysis in pharmaceutics: A tutorial review. International Journal of Pharmaceutics. 280-290.

Se fullstendig oversikt over publikasjoner i CRIStin.

Arneberg R., Rajalahti T., Flikka K., Berven F.S., Kroksveen A.C., Berle M., Myhr K.-M., Vedeler C., Ulvik  R.J., Kvalheim O.M. (2007) Pretreatment of mass spectral profiles: Applications to proteomic data, Anal. Chem., 79, 7014-7026.

Kvalheim O.M., Rajalahti T., Arneberg R. (2009) X-tended Target Projection (XTP) – comparison with ortogonal partial least squares (OPLS) and PLS post-processing by similarity transformation (PLS+ST), J. Chemometrics, 23, 49-55.

Rajalahti T., Arneberg R., Berven F.S., Myhr K.-M., Ulvik R.J., Kvalheim O.M. (2009) Biomarker discovery in mass spectral profiles by means of selectivity ratio plot, Chemometrics & Intell. Lab. Syst., 95, 35-48.

Rajalahti T., Arneberg R, Kroksveen A.C., Berle M., Myhr K.-M., Kvalheim O.M. (2009) Discriminating variables test and selectivity ratio plot – Quantitative tools for interpretation and variable (biomarker) selection in complex spectral or chromatographic profiles, Analytical Chemistry, 81, 2581-90.

Chau F.-T., Chan H.-Y., Cheung C.-Y., Xu C.-J., Liang Y., Kvalheim O.M. (2009) Recipe for Uncovering the Bioactive Components in Herbal Medicine, Analytical Chemistry, 81, 7217-7225.

Rajalahti T., Kroksveen A.C., Arneberg R., Berven F.S., Vedeler C., Myhr K.-M., Kvalheim O.M. (2010) A multivariate approach to reveal biomarker signatures for disease classification: Application to mass spectral profiles of cerebrospinal fluid from patients with multiple sclerosis, J. Proteome Res., 9, 3608-3620.

Kvalheim O.M. (2010) Interpretation of partial least squares regression models by means of target projection and selectivity ratio plots, J. Chemometrics, 24, 496-504.

Kvalheim O.M., Chan H.-Y., Lau T.-Y., Benzie I.F.F, Szeto Y.-T., Tzang A.H.-C., Chau F.-T. (2011) Chromatographic Profiling and Multivariate analysis for revealing and quantifying the contributions from individual components to the Bioactive Signature in Natural Products, Chemom. & Intell. Lab. Syst., in press.

Rajalahti T., Kvalheim O.M. (2011), Multivariate data analysis in pharmaceutics: a tutorial review, Intern. J. Pharmaceutics, in press.