Ashoka D. Polpitiya

ORCID: 0000-0001-5439-1375
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About
Contact & Profiles
Research Areas
  • Advanced Proteomics Techniques and Applications
  • Metabolomics and Mass Spectrometry Studies
  • Preterm Birth and Chorioamnionitis
  • Neonatal Respiratory Health Research
  • Mass Spectrometry Techniques and Applications
  • Infant Nutrition and Health
  • Gene expression and cancer classification
  • Bioinformatics and Genomic Networks
  • Ophthalmology and Eye Disorders
  • Pneumonia and Respiratory Infections
  • Evolution and Genetic Dynamics
  • Gene Regulatory Network Analysis
  • Control and Dynamics of Mobile Robots
  • Glaucoma and retinal disorders
  • Microbial Metabolic Engineering and Bioproduction
  • Gaze Tracking and Assistive Technology
  • Axon Guidance and Neuronal Signaling
  • Cell Image Analysis Techniques
  • Aortic aneurysm repair treatments
  • Connective tissue disorders research
  • Clusterin in disease pathology
  • Retinal Development and Disorders
  • Vestibular and auditory disorders
  • Bacterial Infections and Vaccines
  • Clinical practice guidelines implementation

University of Colombo
2021

Prognos (Germany)
2015

Wright State University
2015

Christiana Care Health System
2015

Cincinnati Children's Hospital Medical Center
2015

Coombe Women & Infants University Hospital
2015

University of Miami
2015

Royal College of Surgeons in Ireland
2015

Medical University of South Carolina
2015

Duke University
2015

After hundreds of generations adaptive evolution at exponential growth, Escherichia coli grows as predicted using flux balance analysis (FBA) on genome‐scale metabolic models (GEMs). However, it is not known whether the pathway usage in FBA solutions consistent with gene and protein expression wild‐type evolved strains. Here, we report that >98% active reactions from optimal growth are supported by transcriptomic proteomic data. Moreover, when E. adapts to rate selective pressure, strains...

10.1038/msb.2010.47 article EN cc-by-nc-sa Molecular Systems Biology 2010-01-01

Abstract Summary: Data Analysis Tool Extension (DAnTE) is a statistical tool designed to address challenges associated with quantitative bottom-up, shotgun proteomics data. This has also been demonstrated for microarray data and can easily be extended other high-throughput types. DAnTE features selected normalization methods, missing value imputation algorithms, peptide-to-protein rollup an extensive array of plotting functions comprehensive hypothesis-testing scheme that handle unbalanced...

10.1093/bioinformatics/btn217 article EN Bioinformatics 2008-05-03

Mass spectrometry-based proteomics has become the tool of choice for identifying and quantifying proteome an organism. Though recent years have seen a tremendous improvement in instrument performance computational tools used, significant challenges remain, there are many opportunities statisticians to make important contributions. In most widely used "bottom-up" approach proteomics, complex mixtures proteins first subjected enzymatic cleavage, resulting peptide products separated based on...

10.1214/10-aoas341 article EN The Annals of Applied Statistics 2010-12-01

Abstract Motivation: The size and complex nature of mass spectrometry-based proteomics datasets motivate development specialized software for statistical data analysis exploration. We present DanteR, a graphical R package that features extensive diagnostic functions quantitative analysis, including normalization, imputation, hypothesis testing, interactive visualization peptide-to-protein rollup. More importantly, users can easily extend the existing functionality by their own algorithms...

10.1093/bioinformatics/bts449 article EN Bioinformatics 2012-07-19

Preterm delivery remains the leading cause of perinatal mortality. Risk factors and biomarkers have traditionally failed to identify majority preterm deliveries.To develop validate a mass spectrometry-based serum test predict spontaneous in asymptomatic pregnant women.A total 5501 women were enrolled between 17(0/7) 28(6/7) weeks gestational age prospective Proteomic Assessment study at 11 sites United States 2011 2013. Maternal blood was collected enrollment outcomes following delivery....

10.1016/j.ajog.2016.02.001 article EN cc-by-nc-nd American Journal of Obstetrics and Gynecology 2016-02-11

Cyanothece sp. ATCC 51142 is a diazotrophic cyanobacterium notable for its ability to perform oxygenic photosynthesis and dinitrogen fixation in the same single cell. Previous transcriptional analysis revealed that existence of these incompatible cellular processes largely depends on tightly synchronized expression programs involving ∼30% genes genome. To expand upon current knowledge, we have utilized sensitive proteomic approaches examine impact diurnal rhythms protein complement 51142. We...

10.1371/journal.pone.0016680 article EN cc-by PLoS ONE 2011-02-22

Novel biomarkers of type 1 diabetes must be identified and validated in initial, exploratory studies before they can assessed proficiency evaluations. Currently, untargeted "-omics" approaches are underutilized profiling clinical samples. This report describes the evaluation capillary liquid chromatography (LC) coupled with mass spectrometry (MS) a pilot proteomic analysis human plasma serum from subset control diabetic individuals enrolled Diabetes Autoantibody Standardization Program, goal...

10.1021/pr700606w article EN Journal of Proteome Research 2007-12-20

The quantitative comparison of protein abundances across a large number biological or patient samples represents an important proteomics challenge that needs to be addressed for discovery applications. Herein, we describe strategy incorporates stable isotope 18O-labeled "universal" reference sample as comprehensive set internal standards analyzing sets quantitatively. As pooled sample, the is spiked into each individually processed unlabeled and peptide/protein are quantified based on...

10.1021/pr800467r article EN Journal of Proteome Research 2008-11-21

In this paper, we study the human oculomotor system as a simple mechanical control system. It is well known physiological fact that all eye movements obey Listing's law, which states orientations form subset consisting of rotation matrices for axes are orthogonal to normal gaze direction. First, discuss geometry restricted configuration space (referred Listing space). Then formulate with holonomic constraint. We propose realistic model musculotendon complexes and address question controlling...

10.1109/tac.2006.887902 article EN IEEE Transactions on Automatic Control 2007-02-01

Hybrid two-stage mass spectrometers capable of both highly accurate measurement and high throughput MS/MS fragmentation have become widely available in recent years, allowing for significantly better discrimination between true false peptide identifications by the application a relatively narrow window maximum allowable deviations measured parent ion masses. To fully gain advantage measurements, it is important to limit systematic errors. Based on our previous studies biases errors, here, we...

10.1074/mcp.m900217-mcp200 article EN cc-by Molecular & Cellular Proteomics 2009-12-18

MultiAlign is a free software tool that aligns multiple liquid chromatography-mass spectrometry datasets to one another by clustering mass and chromatographic elution features across datasets. Applicable both label-free proteomics metabolomics comparative analyses, the can be operated in several modes. For example, clustered matched reference database identify analytes, used generate abundance profiles, linked tandem spectra based on parent precursor masses, culled for targeted...

10.1186/1471-2105-14-49 article EN cc-by BMC Bioinformatics 2013-02-12

Here, we report a new approach that integrates pulsed Q dissociation (PQD) and electron transfer (ETD) techniques for confident quantitative identification of iTRAQ-labeled phosphopeptides. The use isobaric tags relative absolute quantification enables high-throughput peptides via reporter ion signals in the low m/z range tandem mass spectra. PQD, form trap collision activated dissociation, allows detection mass-to-charge fragment ions, is especially useful sequencing contain...

10.1021/ac802605m article EN Analytical Chemistry 2009-04-16

The DNA damage response likely includes a global phosphorylation signaling cascade process for sensing the damaged condition and coordinating responses to cope with repair perturbed cellular state. We utilized label-free liquid chromatography−mass spectrometry approach evaluate changes in protein associated PP5 activity during response. Biological replicate analyses of bleomycin-treated HeLa cells expressing either WT-PP5 or mutant inactive lead identification six potential target proteins...

10.1021/pr9008207 article EN Journal of Proteome Research 2009-12-29

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Animals routinely rely on their eyes to localize fixed and moving targets. Such a localization process might include prediction of future target location, recalling sequence previously visited places or, for the motor control circuit, actuating successful movement. Typically, is carried out by fusing images from two eyes, in case binocular vision, wherein challenge have calibrated before fusion....

10.1109/jproc.2006.887320 article EN Proceedings of the IEEE 2007-01-01

Recent anatomical studies of extraocular muscles (EOM) demonstrate the stability muscle paths. This is due to fact that each rectus EOM passes through a pulley consisting an encircling ring or sleeve collagen. In this paper, EOMs are modeled using Hill type musculotendon complex and effect pulleys studied. The model proposed by Martin Schovanec (1999) for horizontal eye movement has been used as basic starting point. then introduced analyzed mainly study how Listing's law enforced it...

10.1109/acc.2002.1023985 article EN 2002-01-01

Gaze control in three dimensions is achieved by the geometrical arrangement of extra-ocular muscles. For head-fixed saccadic eye movements, ocular rotation axis constrained according to Listing's law. In this paper, an model developed gaze. Quaternions associated with positions and rotations are used precisely describe rotation.

10.1109/cdc.2003.1272353 article EN 2004-07-08

There is physiological evidence to support the thesis that all saccadic eye movements obey Listing's law, which states orientations form a subset consisting of rotation matrices axes are orthogonal normal gaze direction. Here we analyze geometry this restricted configuration space (referred as Listing space). We also compare distances needs travel subject law with geodesic in group.

10.23919/acc.2004.1383625 article EN 2004-01-01

Living cells are complex dynamic systems, showing a remarkable ability to adapt different environmental conditions for their survival. Central this characteristic trait is an underlying regulatory mechanism that controls various biological processes. Unraveling the basic principles of cellular regulation fundamental challenge and main subject article. In medical sciences, understanding can lead new treatments diseases, such as cancer diabetes, while facilitating drug discovery. agriculture,...

10.1109/mcs.2010.938100 article EN IEEE Control Systems 2010-11-30

Independent, greedy collection of data events using simple heuristics results in massive over-sampling the prominent features large-scale studies over what should be achievable through ¿intelligent", online acquisition such data. As a result, generated are more aptly described as large number small experiments rather than true experiment. Nevertheless, achieving ¿intelligent¿, control requires tight interplay between state-of-the-art, data-intensive computing infrastructure developments and...

10.1109/e-science.2009.21 article EN 2009-12-01

Introduction: Preterm birth (PTB), a condition with complex etiological factors, is the leading cause of neonatal mortality and morbidity. Existing tests have poor performance, especially for nulliparous women. There compelling need to identify robust biomarkers PTB enable identification at-risk A single-analyte assay may not be sufficient detect women at risk …

10.1093/ajcp/144.suppl2.065 article EN American Journal of Clinical Pathology 2015-10-01
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