BCIT Citations Collection | BCIT Institutional Repository

BCIT Citations Collection

Pages

A declarative model for reasoning about form security
Proceedings of the International Conference on Agents and Artificial Intelligence in Lisbon, Portugal 2015. We introduce a formal methodology for analysing the security of digital forms, by representing form signing procedures in a declarative action formalism. In practice, digital forms are represented as XML documents and the security of information is guaranteed through the use of digital signatures. However, the security of a form can be compromised in many different ways. For example, an honest agent might be convinced to make a commitment that they do not wish to make or they may be fooled into believing that another agent has committed to something when they have not. In many cases, these attacks do not require an intruder to break any form of encryption or digital signature; instead, the intruder simply needs to manipulate the way signatures are applied and forms are passed between agents. In this paper, we demonstrate that form signing procedures can actually be seen as a variation of the message passing systems used in connection with cryptographic protocols. We start with an exis ting declarative model for reasoning about cryptographic protocols in the Situation Calculus, and we show how it can be extended to identify security issues related to digital signatures, and form signing procedures. We suggest that our results could be used to help users create secure digital forms, using tools such as IBM’s Lotus Forms software., Conference paper, Published.
Design, learn, and play
Proceedings of 2015 Annual Meeting of the American Educational Research Association, Chicago, Illinois, 2015. Evidence suggests that computer game-based learning (GBL) environments are effective in increasing students’ motivation and supporting learning (de Freitas, 2013; Kiili, Ketamo, Koivisto, & Finn, 2014; Spires, Rowe, Mott, & Lester, 2011). Many intelligent tutoring systems and advanced learning technologies are designed as educational games (Aleven, Beal, & Graesser, 2013; Conati, Jaques, & Muir, 2013; Rodrigo, et al., 2012). This paper presents the lessons learned during the design, implementation and evaluation of an educational game, Heroes of Math Island, for students in grades five through seven. The game was designed and implemented with the purpose of researching (1) affective states that are relevant to learning during gameplay and (2) methods that are better suited for design of engaging educational games. This paper focuses on the second objective., Conference paper, Published., Peer reviewed
Design of a dynamic model of genes with multiple autonomous regulatory modules by evolutionary computations
A new approach to design a dynamic model of genes with multiple autonomous regulatory modules by evolutionary computations is proposed. The approach is based on Genetic Algorithms (GA), with new crossover operators especially designed for these purposes. The new operators use local homology between parental strings to preserve building blocks found by the algorithm. The approach exploits the subbasin-portal architecture of the fitness functions suitable for this kind of evolutionary modeling. This architecture is significant for Royal Road class fitness functions. Two real-life Systems Biology problems with such fitness functions are implemented here: evolution of the bacterial promoter rrnP1 and of the enhancer of the Drosophila even-skipped gene. The effectiveness of the approach compared to standard GA is demonstrated on several benchmark and reallife tasks., Peer-reviewed article, Published.
Designing an educational game (Heroes of Math Island)
Proceedings of the 2014 Annual Meeting of the American Educational Research Association, Philadelphia, Pennsylvania. In response to the need for more empirical research with respect to emotion and learning, this study provided an empirical investigation of the students’ interaction with an educational game, Heroes of Math Island, specifically designed for this study. The purpose of this study was to explore learners’ emotional states triggered during gameplay with the goal of providing critical information needed for the design of advanced learning technologies (ALTs) and intelligent tutoring systems (ITSs). The study used the design-based research (DBR) paradigm by combining exploration with design, and mixed methodologies including: pretest, intervention (gameplay), posttest, post-questionnaire, and interview. Fifteen students (seven boys and eight girls) from grades six and seven participated in this study. Findings report on heuristics of educational technology design, emotion, and learning., Conference paper, Published., Peer reviewed
Determination of Aloin A and Aloin B in aloe vera raw materials and finished products by high-performance liquid chromatography
A single-laboratory validation (SLV) was conducted on an HPLC method for the detection and quantification of aloin A and aloin B in Aloe vera raw materials and finished products. An extraction procedure using sonication with an acidified solvent was used for solid test materials while liquid test materials only required dilution, if necessary, prior to filtration and analysis. Separation was achieved using a fused core C18 column in 18 min under isocratic elution conditions allowing for a single analyte (aloin A) calibration curve to quantify both aloins. Adequate chromatographic resolution (Rs ≥ 1) was achieved for aloin A and aloin B. The calibration curves for aloin A exhibited coefficients of determination (r(2)) of ≥ 99.9% over the linear range of 0.3-50 μg/mL. The LOD values were 0.092 and 0.087 μg/mL, and LOQ 0.23 and 0.21 μg/mL for aloin A and aloin B, respectively. Repeatability studies were performed on nine test materials on each of 3 separate days, with five of the test materials determined to be above the LOQ having repeatability RSD (RSDr) values ranging from 0.61 to 6.30%. Method accuracy was determined through a spike recovery study on both liquid and solid matrixes at three different levels: low, medium, and high. For both aloins, the recovery in the liquid matrix ranged from 92.7 to 106.3% with an RSDr of 0.15 to 4.30%, while for the solid matrix, the recovery ranged from 84.4 to 108.9% with an RSDr of 0.23 to 3.84%. Based on the results of the SLV study, it is recommended that this method be evaluated for reproducibility through a collaborative study., Peer-reviewed article, Published. Received January 27, 2013; Accepted by AP April 10, 2014.
Determination of anthocyanins in cranberry fruit and cranberry fruit products by high-performance liquid chromatography with ultraviolet detection
A single-laboratory validation study was conducted on an HPLC method for the detection and quantification of cyanidin-3-O-galactoside (C3Ga), cyanidin-3-O-glucoside (C3GI), cyanidin-3-O-arabinoside (C3Ar), peonidin-3-O-galactoside (P3Ga), and peonidin-3-O-arabinoside (P3Ar) in cranberry fruit (Vaccinium macrocarpon Aiton) raw material and finished products. An extraction procedure using a combination of sonication and shaking with acidified methanol was optimized for all five anthocyanins in freeze-dried cranberry fruit and finished products (commercial extract powder, juice, and juice cocktail). Final extract solutions were analyzed by HPLC using a C18 RP column. Calibration curves for all anthocyanin concentrations had correlation coefficients (r2) of > or = 99.8%. The method detection limits for C3Ga, C3Gl, C3Ar, P3Ga, and P3Ar were estimated to be 0.018, 0.016, 0.006, 0.013, and 0.011 microg/mL, respectively. Separation was achieved with a chromatographic run time of 35 min using a binary mobile phase with gradient elution. Quantitative determination performed in triplicate on four test materials on each of 3 days (n = 12) resulted in RSD(r) from 1.77 to 3.31%. Analytical range, as defined by the calibration curves, was 0.57-36.53 microg/mL for C3Ga, 0.15-9.83 microg/mL for C3GI, 0.28-17.67 microg/mL for C3Ar, 1.01-64.71 microg/mL for P3Ga, and 0.42-27.14 microg/mL for P3Ar. For solid materials prepared by the described method, this translates to 0.06-3.65 mglg for C3Ga, 0.02-0.98 mg/g for C3Gl, 0.03-1.77 mg/g for C3Ar, 0.10-6.47 mg/g for P3Ga, and 0.04-2.71 mg/g for P3Ar., Peer-reviewed article, Published. Received August 5, 2010; Accepted by AP October 27, 2010.
Determination of ginsenoside content in Asian and North American ginseng raw materials and finished products by high-performance liquid chromatography
A single-laboratory validation study was conducted for the quantification of Rg1, Re, Rb1, Rc, Rb2, and Rd in Asian ginseng (Panax ginseng C.A. Meyer) and North American ginseng (Panax quinquefolius L.) raw materials and finished products by RP-HPLC. The extraction with aqueous methanol was optimized for whole root, powdered extract, and finished product (raw, tablet, and capsule matrixes) test articles. Root materials were treated with base to hydrolyze acidic malonyl ginsenosides to their neutral counterparts. Calibration curves for each ginsenoside were linear over the following ranges (microg/g): 5-394 for Rg1, 15-1188 for Re, 39-2981 for Rb1, 6-499 for Rc, 5-406 for Rb2, and 7-600 for Rd, all having a coefficient of determination (r2) of > or = 99.5%. The LOD for Rg1, Re, Rb1, Rc, Rb2, and Rd was determined to be 1.06, 1.25, 2.19, 1.24, 1.27, and 1.70 microg/mL, respectively. Quantitative determinations performed with eight test materials by two analysts over 3 days (n = 12) resulted in RSDr values that ranged from 1.11 to 7.61%., Peer-reviewed article, Published. Received May 10, 2011; Accepted by AP May 11, 2011.
Determination of ginsenoside content in Panax ginseng C.A. Meyer and Panax quinquefolius L. root materials and finished products by high-performance liquid chromatography with ultraviolet absorbance detection
An interlaboratory study was conducted on an HPLC method with UV absorbance detection, previously validated using AOAC single-laboratory validation guidelines, for the determination of the six major ginsenosides (Rg1, Re, Rb1, Rc, Rb2, and Rd) in Panax ginseng C.A. Meyer and Panax quinquefolius L. root materials, extracts, and finished products. Fourteen participating laboratories analyzed five test materials (P. ginseng whole root, P. ginseng powdered extract, P. quinquefolius whole root, P. quinquefolius powdered extract, and P. ginseng powdered extract spiked in a matrix blank) as blind duplicates, and two test materials (P. ginseng powdered whole root tablet and P. quinquefolius powdered extract hard-filled capsule) as single samples. Due to the variability of the ginsenosides (low level concentration of Rb2 in P. quinquefolius raw materials and in P. ginseng spiked matrix blanks, and the possibility of incomplete hydrolysis of the finished products during processing), it was deemed more applicable to analyze total ginsenosides rather than individual ones. Outliers were evaluated and omitted using the Cochran's test and single and double Grubbs' tests. The reproducibility RSD (RSD(R)) for the blind duplicate samples ranged from 4.38 to 5.39%, with reproducibility Horwitz Ratio (HorRat(R)) values ranging from 1.5 to 1.9. For the single replicate samples, the data sets were evaluated solely by their repeatability HorRat (HorRat(r)), which were 2.9 and 3.5 for the capsule and tablet samples, respectively. Based on these results, the method is recommended for AOAC Official First Action for the determination of total ginsenosides in P. ginseng and P. quinquefolius root materials and powdered extracts., Peer-reviewed article, Published.
Determination of hydrastine and berberine in goldenseal raw materials, extracts, and dietary supplements by high-performance liquid chromatography with UV
A multilaboratory collaborative study was conducted on a high-performance liquid chromatographic (HPLC) method utilizing UV detection, previously validated using AOAC single-laboratory validation guidelines for determination of hydrastine and berberine in goldenseal (Hydrastis canadensis L.) raw materials, extracts, and dietary supplements at levels ranging from 0.4 to 6% (w/w). Nine collaborating laboratories determined the hydrastine and berberine content in 8 blind samples. Sample materials included powdered botanical raw materials, whole root material, and 4 finished product dietary supplements containing either goldenseal powdered root material or extract. The materials were extracted with an acidified water and acetonitrile solution. HPLC analyses of the extracts were performed on a C18 column using UV detection at 230 nm. Results for powdered root material and capsule products ranged from about 0.2% (w/w) for each alkaloid to about 4% (w/w) for each alkaloid. Liquid tincture results were approximately 4000-5000 microg/mL for each alkaloid. Reproducibility relative standard deviations (RSDR) for hydrastine ranged from 2.68 to 6.65%, with HorRat values ranging from 0.77 to 1.89. RSDR for berberine ranged from 5.66 to 7.68%, with HorRat values ranging from 1.32 to 2.12. All finished products containing goldenseal extract yielded HorRat values <2.0. Based on these results, the method is recommended for Official First Action for determination of hydrastine and berberine in goldenseal raw materials and dietary supplement finished products containing powdered goldenseal and goldenseal extract., Peer-reviewed article, Published.
Determination of major phenolic compounds in Echinacea spp. raw materials and finished products by high-performance liquid chromatography with ultraviolet detection
A method previously validated to determine caftaric acid, chlorogenic acid, cynarin, echinacoside, and cichoric acid in echinacea raw materials has been successfully applied to dry extract and liquid tincture products in response to North American consumer needs. Single-laboratory validation was used to assess the repeatability, accuracy, selectivity, LOD, LOQ, analyte stability (ruggedness), and linearity of the method, with emphasis on finished products. Repeatability precision for each phenolic compound was between 1.04 and 5.65% RSD, with HorRat values between 0.30 and 1.39 for raw and dry extract finished products. HorRat values for tinctures were between 0.09 and 1.10. Accuracy of the method was determined through spike recovery studies. Recovery of each compound from raw material negative control (ginseng) was between 90 and 114%, while recovery from the finished product negative control (maltodextrin and magnesium stearate) was between 97 and 103%. A study was conducted to determine if cichoric acid, a major phenolic component of Echinacea purpurea (L.) Moench and E. angustifolia DC, degrades during sample preparation (extraction) and HPLC analysis. No significant degradation was observed over an extended testing period using the validated method., Peer-reviewed article, Published.
Determination of mitragynine in mitragyna speciosa raw materials and finished products by liquid chromatography with UV detection
Mitragyna speciosa (kratom) is a tree indigenous to Southeast Asia, and its leaves are used in herbal formulations because they contain indole alkaloids mitragynine and 7-hydroxy (7-OH) mitragynine. An HPLC method was developed, optimized, and validated using single-laboratory validation guidelines to quantify mitragynine in kratom raw materials and finished products. The method optimization evaluated several extraction parameters including solvent type, solvent volume, time, and extraction method. The separation of the mitragynine alkaloids was achieved in 18 min with a fused-core C18 EVO column using gradient separation with ammonium bicarbonate (pH 9.5) and acetonitrile. The calibration range for mitragynine was 1.0–500 μg/mL with correlation coefficients of ≥99.9% throughout method development and validation. The method detection limit and LOQ were 0.2 and 0.6 μg/mL, respectively for mitragynine. Eight test samples were obtained to evaluate method repeatability. RSDr ranged from 0.4 to 1.0%, whereas intermediate precision ranged from 3.7 to 7.3%, with HorRat values from 0.68 to 1.96. 7-OH mitragynine was below the LOQ for all samples, therefore, spikes repeatability sample RSD values were <1%. The validation data presented meet the Standard Method Performance Requirements as specified by the AOAC INTERNATIONAL Kratom Working Group., Peer-reviewed article, Published. Received July 12, 2016; Accepted by AP September 12, 2016.
Determination of phenolic constituents in echinacea raw materials and dietary supplements by HPLC-UV
A collaborative study was conducted to evaluate an HPLC method for determining phenolic compounds in Echinacea spp. raw materials, powdered extracts, and tinctures. Eleven collaborating laboratories received three practice samples representing each matrix type, phenolic reference standards, eight test samples as blind duplicates, the validated analytical method, and instructions. Test samples included two raw materials, four extracts (including one in combination with astragalus and reishi), one ethanolic tincture in combination with goldenseal, and one glycerite tincture. Each material was extracted with a 60% methanol aqueous solution, separated on a C18 column, and detected at 330 nm. Results reported by laboratories for total phenolics in Echinacea roots, aerial parts, and extracts ranged from 9.5 to 62.9 mg/g with RSDR ranging from 3.64 and 7.95% and Horwitz ratio (HorRat) values ranging from 1.06 to 2.01. Total phenolics in the ethanolic tincture ranged from 4837 to 5962 μg/mL, with an RSDR of 6.35% and a HorRat value of 1.45. The glycerite tincture showed poor interlaboratory precision with a HorRat value of 3.32, an RSDR of 21.8%, and reported total phenolic values ranging from 257 to 539 μg/mL., Peer-reviewed article, Published. Received May 4, 2016; Accepted by AP May 25, 2016.

Pages