UHCL Faculty Works (Abstracts Only)

Permanent URI for this communityhttps://hdl.handle.net/10657.1/879

Browse

Now showing 1 - 20 of 401

30-Day Mortality Prediction of Patients With Congestive Heart Failure (CHF)
(2016-05-21) Khuriekar, N.; Aladeemy, M.; Chou, C. A.; Shan, Xiaojun; Poranki, S.; Khasawneh, M. T.; Srihari, K.
The paper builds a prediction model of 30-day mortality risk in patients with CHF. Least absolute shrinkage and selection operator (LASSO) was applied to select the significant features. Three data mining techniques, namely, decision tree, logistic regression, and AdaBoost.M1 algorithms were used to predict mortality risk in patients with CHF. A case study was conducted using data (January 2012 to December 2014) from a community hospital in Upstate New York and a comparison among the three predictive algorithms was performed. The primary measure for comparing the performance of the prediction algorithms were area under the receiver operating characteristic curve (AUC), specificity, sensitivity, and accuracy. The results show that logistic regression model resulted in an accuracy of 84.85% with the specificity, sensitivity and AUC of 1, 0.44 and 0.72, respectively. On the other hand, the decision tree algorithm resulted in an accuracy of 75.76% with specificity, sensitivity and AUC of 0.83, 0.56 and 0.69, respectively, whereas the AdaBoost.M1 algorithm resulted in 81.82% accuracy with specificity, sensitivity and AUC of 0.56, 0.54 and 0.55, respectively. This research concludes that the logistic regression model fitted with LASSO outperforms AdaBoost.M1 and decision tree in terms of both AUC score as well as predictive accuracy. Accurate prediction of 30-day mortality based on this research can be useful in risk stratification, individualized treatment, and patient management.
Absolute Configuration and Polymorphism of 2-phenylbutyramide and a-methyl -a-phenylsuccinimide
(Crystal Growth & Designs, 2014) Krivoshein, Arcadius
Crystal structures of racemic and homochiral forms of 2-phenylbutyramide (1) and 3-methyl-3-phenylpyrrolidine-2,5-dione (2) were investigated in detail by a single crystal X-ray diffraction study. Absolute configurations of the homochiral forms of 1 and 2, obtained by chromatographic separation of racemates, were determined. It was revealed that racemate and homochiral forms of 1 are very similar in terms of supramolecular organization (H-bonded ribbons) in crystal, infrared (IR) spectral characteristics, and melting points. The presence of two different molecular conformations in homochiral forms of 1 allowed mimicking of crystal packing of the H-bonded ribbons in racemate 1. Two polymorph modifications (monoclinic and orthorhombic) comprising very similar H-bonded zigzag-like chains were found for the homochiral forms of compound 2 that were significantly different in terms of crystal structure, IR spectra, and melting points from the racemic form of 2. Unlike compound 1, homochiral forms of compound 2 have a higher density than the corresponding racemate which contradicts the Wallach rule and indicates that, in this case, homochiral forms are more stable than racemate forms.
Accurate Characterization of Moisture Absorption in Polymeric Materials
(SPE Plastics Research Online, 2017) Hamidi, Youssef
The importance of using the exact solution of the hindered diffusion model is demonstrated on experimental data from a nanoclay/epoxy composite.
Acoustic Flame Suppression Mechanics in a Microgravity Environment
(Microgravity Science and Technology, 2015) Yue, Kwok-Bun
The following paper deals with acoustic flame suppression mechanics in a microgravity environment with measurements taken from an Arduino-based sensor system and validation of the technique. A Zippo lighter is ignited in microgravity and then displaced from the base of the flame and suppressed using surface interactions with single tone acoustic waves to extinguished the flame. The analysis of data collected shows that the acoustic flame suppression measurementtechniques are effective to finding qualitative differences in extinguishing in microgravity and normal gravity. Further, the results suggest that the suppression may be more effective in a microgravity environment than in a normal (1g) environment and may be a viable method of extinguishing fires during space flight.
An Ada Solution to the General Mutual Exclusion Problem
(Ada Letters, 1993) Yue, Kwok-Bun
Although some specific mutual exclusion problems have been studied extensively, automatic solutions to synchronize general mutual exclusion problems with arbitrary mutual exclusion constraints have not been fully explored. This paper discusses an Ada 83 solution that can be applied to any general mutual exclusion problem. This solution is based on strong binary semaphores. A generic package is used to generate the solution for an given mutual exclusion problem. An Ada program for the simulation of the classical Dining Philosophers Problem is presented as an example to demostrate how the solution can be used.
Adaptive Privacy-Preserving Authentication in Vehicular Networks
(Journal of Computer Science and Technology, 2008) Kewei, Sha
Vehicular networks have attracted extensive attention in recent years for their promises in improving safety and enabling other value-added services. Most previous work focuses on designing the media access and physical layer protocols. Privacy issues in vehicular networks have not been well addressed. We argue that privacy is a user-specific concept and a good privacy protection mechanism should allow users to select the degree of privacy they wish to have. To address this requirement, we propose an adaptive privacy-preserving authentication mechanism that can trade off the privacy degree with computational and communication overheads (resource usage). This mechanism, to our knowledge, is the first effort on adaptive privacy-preserving authentication. We present analytical and preliminary results to show that the proposed protocol is nt only adaptive but scalable.
An Advanced Bus Architecture for AES-Encrypted High-Performance Embedded Systems
(2017-10-19) Yang, Xiaokun
Methods and systems of AES-centric bus architectures and AES-centric state transfer modes are provided. The bus architecture may be implemented on system-on-chip (SoC) devices in conjunction with existing intellectual property (IP) cores. The bus architecture can include a control-bus with a single master, such as a microprocessor, and a data-bus with a single slave, such as DMA.
Aerobic Biodegradation Kinetics of Four Anionic and Nonionic Surfactants at Sub and Supra Critical Micelle Concentrations
(Water Resarch, 1999) Zhang, Carl
Aerobic biodegradation of four representative commercial surfactants under a range of concentrations (i.e., sub- and supra-critical micelle concentrations, CMCs) beyond those ordinarily used in biodegradation studies was investigated. Of the four surfactants tested, sodium dodecylbenzene sulfonate (SDBS) showed no biodegradation and foam degradation. At a sub-CMC (500 mg/l), primary biodegradation, as measured by methylene blue active substances (MBAS) for an anionic surfactant sodium dodecyl sulphate (SDS) and by cobalt thiocyanate active substances (CTAS) for a nonionic surfactant Witconol, followed Monod kinetics, substrate depletion being a function of both microbial growth and substrate concentrations. However, primary biodegradation at supra-CMCs (500 for Tergitol and 2500 mg/l for SDS and Witconol) and ultimate biodegradation (mineralization) at both sub- and supra-CMCs were best described by first-order kinetics, the degradation rate being a sole function of substrate concentrations. Parameters for the kinetic models (Ks, Y, μmax, and k) were estimated using non-linear least squares methods. Increasing surfactant concentrations from sub- to supra-CMCs significantly decreased primary biodegradation, ultimate biodegradation, and foam degradation. This decrease may be attributed to the limited bioavailability of surfactants in the micellar phase as compared to the monomeric surfactants. The results are of significance for surfactant-based remediation, since the concentrations of surfactants employed in remediation are typically much higher than CMCs, while surfactant concentrations of primary interest in biodegradation work are in the neighborhood of and below 10 mg/l, which is usually 10–100 times lower than CMCs.
An Algorithm for Combining Graphs Based on Shared Knowledge
(International Conference on Bioinformatics and Computational Biology, 2012) Bettayeb, Said
We propose an algorithm for connecting nodes from multiple disconnected graphs based on a given tuple set representing shared knowledge. The set of tuples is used to create bridgeedges for combining two graphs. The path from a node in a graph to a node in the other graph passes through a bridgeedge. This method of combining two graphs will enable more comprehensive understanding and exploring of the relatedness of the knowledge entities (the nodes) in two graphs based on a given domain knowledge represented in the set of tuples. This approach has useful applications in various domains and in particular in bioinformatics. In bioinformatics, for example, we can explore the functional relationship between two gene products given their Gene Ontology annotation terms from the molecular function MF and biological process BP graphs of GO. Moreover, the proposed algorithm can be applied to WordNet to enable exploring the relative degree of relatedness of words from multiple lexical hierarchies, like nouns and verbs, within the WordNet.
Amino acid biosynthesis in chloroplasts
(Balaban International Science Service, 1981) Mills, Ronald
Amino acid biosynthesis in isolated pea chloroplasts: metabolism of labeled aspartate and sulfate
(FEBS Letters, 1978) Mills, Ronald
Accumulating evidence points to chloroplasts as the site of nitrite and sulfate reduction and incorporation into carbon skeletons [I] Furthermore, several enzymes of aspartate-family amino acid biosynthesis recently have been localized in plastids. These are : aspartate kinase [2] , homoserine dehydrogenase [3] , diaminopimelate decarboxylase [4] , acetolactate synthetase [S] and homocysteine-dependent 5-methyltetrahydrqpteroyl glutamate transmethylase [6]. In whole plants Lys and/or Thr have been shown to regulate the production of the aspartatederived amino acids [7]. Biosynthesis of this family of amino acids and its regulation in isolated chloroplasts has, however, received little attention. In this report we describe the biosynthesis of amino acids in pea chloroplasts from labeled aspartate and sulfate.
Anaerobic Biotransformation of 2,4-Dinitrotoluene and 2,6-Dinitotoluene by Clostridium acetobutylicum: A Pathway through Dihydroxylamino-Intermediates
(Environmental Science and Technology, 1999) Zhang, Carl
Experiments were conducted to isolate and identify the intermediates and products of 2,4-dinitrotoluene and 2,6-dinitrotoluene metabolism by Clostridium acetobutylicum. Transformation of both dinitrotoluenes initially resulted in the formation of hydroxylaminonitrotoluenes. Subsequent transformation favored the formation of dihydroxylaminotoluenes, with a limited reduction to aminonitrotoluene isomers. In cell cultures, metabolism beyond the level of dihyroxylaminotoluene was not observed. In cell extracts, where activity could be maintained for periods in excess of those in cell cultures, further transformation yielded aminohydroxylaminotoluenes and eventually diaminotoluenes. These findings further demonstrate the potential for hydroxylamines to be significant intermediates of nitroaromatic transformation under anaerobic fermentative conditions. Interestingly, the rearrangement of dihydroxylaminotoluenes was not observed, as was the case in previous studies of 2,4-dihydroxylamino-6-nitrotoluene metabolism (e.g., the dihydroxylamino metabolite of 2,4,6-trinitrotoluene transformation by C. acetobutylicum). Dihydroxylaminotoluenes were found to be quite unstable, decomposing rapidly upon exposure to oxygen, complicating the assessment of their fate in remediation processes.
Analysis and Metrics of XML Schema
(Proceedings of the 2004 International Conference on Software Engineering Research and Practice, 2004-06) Yue, Kwok-Bun
Despite the ubiquity of XML, research in metrics for XML documents is scarce. This paper proposes and discusses eleven metrics to measure the quality and complexity of XML Schema and conforming XML documents. To provide an easy view of these metrics, two composite indices have been defined to measure quality and complexity. An open source metric analyzer tool for XML Schema has been developed. The tool can easily be extended to add new metrics and alter the composition of the indices to best fit the requirements of a given application.
Analysis of Inorganic Nitrogen and Related Anions in High Salinity Water Using Ion Chromatography with Tandem UV and Conductivity Detectors
(Journal of Chromatographic Science, 2011) Zhang, Carl
Over 97% of the Earth's water is high salinity water in the form of gulfs, oceans, and salt lakes. There is an increasing concern for the quality of water in bays, gulfs, oceans, and other natural waters. These waters are affected by many different sources of contamination. The sources are, but not limited to, groundwater run-off of nitrogen containing fertilizer, pesticides, cleaning agents, solid wastes, industrial waters, and many more. The final destinations of these contaminants are rivers, lakes, and bayous that eventually will lead to bays, gulfs, and oceans. Many industries depend on the quality of these waters, such as the fishing industry. In addition to wild marine life, there are large aquariums and fish and shrimp farms that are required to know the quality of the water. However, the ability of these industries to monitor their processes is limited. Most analytical methods do not apply to the analysis of high salinity waters. They are dependent on wet chemistry techniques, spectrophotometers, and flow analyzers. These methods do not have the accuracy, precision, and sensitivity when compared to ion chromatography (IC). Since the inception of IC, it has become a standard practice for determining the content of many different water samples. Many IC methods are limited in the range of analytes that can be detected, as well as the numerous sample sources of which the methods are applicable. The main focus of current IC methods does not include high salinity waters. This research demonstrates an ion chromatographic method that has the ability to determine low level concentrations of inorganic nitrogen and related anions (nitrite-N, nitrate-N, phosphorous-P, sulfate, bromide, chloride, sulfide, fluoride, ammonia, calcium, and magnesium) in a single run using a combination of UV and conductivity detectors. This method is applicable to various waters, and uses both freshwater and high salinity water samples.
Analytical Position and Velocity Partials for Conic and Non-Conic Trajectories
(AAS Paper, 2017-02) Feagin, Terry
Anatomy of the stimulative sequences flanking the ARS consensus sequence of chromosome VI in S. cerevisiae
(Gene, 1994) Rashid, Bazlur
Anticonvulsant Lactams, Cyclic Imides and Acetamides: From Chemical Crystallograpy to Molecular Pharmaceutics
(Current Pharmaceutical Designs, 2016) Krivoshein, Arcadius
The antiepileptic activity of α-substituted acetamides, lactams, and cyclic imides has been known for over six decades. We recently proposed an α-substituted amide group as the minimum pharmacophore responsible for inhibition of neuronal nicotinic acetylcholine receptors by these compounds, with the implication that inhibition of these receptors in the brain might be the unifying mechanism of action for these classes of antiepileptic drugs. In order to realize the pharmacological potential of these orally administered drugs, the relevant aspects of solid-state chemistry and pharmaceutics (including solubility and stability) need to be addressed. A better - more cohesive and generalized - understanding of the solid-state properties of these drugs would pave the road for a rational approach to their development, formulation, and manufacturing. In this paper, Pharmaceutically relevant aspects of the crystal structure and solid-state chemistry of antiepileptic drugs containing the α-substituted amide bond pharmacophore - α-substituted acetamides, lactams, and cyclic imides and the structurally related barbiturates, hydantoins, and acetylureas are reviewed. The applicable experimental and computational approaches are also briefly mentioned.
Anticonvulsants Based on the a-substituted Amide Group Pharmacophore Bind to and Inhibit Functions of Neuronal Nicotinic Acetylcholine Receptors
(ACS Chemical Neuroscience, 2016) Krivoshein, Arcadius
Although the antiepileptic properties of α-substituted lactams, acetamides, and cyclic imides have been known for over 60 years, the mechanism by which they act remains unclear. I report here that these compounds bind to the nicotinic acetylcholine receptor (nAChR) and inhibit its function. Using transient kinetic measurements with functionally active, nondesensitized receptors, I have discovered that (i) α-substituted lactams and cyclic imides are noncompetitive inhibitors of heteromeric subtypes (such as α4β2 and α3β4) of neuronal nAChRs and (ii) the binding affinity of these compounds toward the nAChR correlates with their potency in preventing maximal electroshock (MES)-induced convulsions in mice. Based on the hypothesis that α-substituted amide group is the essential pharmacophore of these drugs, I found and tested a simple compound, 2-phenylbutyramide. This compound indeed inhibits nAChR and shows good anticonvulsant activity in mice. Molecular docking simulations suggest that α-substituted lactams, acetamides, and cyclic imides bind to the same sites on the extracellular domain of the receptor. These new findings indicate that inhibition of brain nAChRs may play an important role in the action of these antiepileptic drugs, a role that has not been previously recognized.
Assessing Information Systems and Computer Information Systems Programs from a Balanced Scorecard Perspective
(Journal of Information Systems Education (JISE), 2012) Yue, Kwok-Bun
Assessment of educational programs is one of the important means used in academia for accountability, accreditation, and improvement of program quality. The assessment practices, guidelines, and requirements are very broad and vary widely among academic programs and from one institution to the other. In this paper, from the theoretical lenses of a strategic planning and management methodology, the Balanced Scorecard, we try to integrate various perspectives into a performance assessment framework for an educational assessment of computing and information systems. Particularly, based on the actual accreditation experience, we propose two assessment models: a conceptual model and a process model. This modeling approach addresses the critical conceptual elements required for educational assessment and provides practical guidelines to follow for a complete, smooth and successful assessment process. In addition, we present a set of robust tools and techniques, incorporated into the process steps, team work, and task-driven management process. We were successful in our accreditation efforts, and improved the quality of our computing and information systems programs by using these presented assessment methods. We share our views and thoughts in the form of lessons learned and suggested best practices so as to streamline program assessment and simplify its procedures and steps.
Assessing the Policy Interaction Effect of Renewable Portfolio Standards (RPS) and Clean Power Plan (CPP) Emissions Goals for States in the U.S. Northeast
(PowerEnergy2016, 2016-06-26) Chandramowli, S. N.; Felder, F. A.; Shan, Xiaojun
With the proposed Clean Power Plan for regulating carbon emissions from the power sector in the U.S, policymakers are likely to use a cost optimization framework to plan for future scenarios and implementation strategies. The modeling framework introduced in this paper would help such policymakers to make the appropriate investment decisions for the power sector. This paper applies an analytical model and an optimization model to investigate the implications of coimplementing an emission cap and a Renewable Portfolio Standards (RPS) policy for the U.S. Northeast. A simplified analytical model is specified and the first order optimality conditions are derived. The results from the analytical model are verified by running simulations using LP-CEM, a linear programming-based supply cost optimization model. The LP-CEM simulation results are analyzed under the recently proposed Clean Power Plan emissions cap rules and RPS scenarios for the U.S. Northeast region. The marginal abatement cost estimates, derived from a limited set of LP-CEM runs, are analyzed and compared to the theoretical results. For encouraging renewables generation, an RPS instrument is costeffective at higher policy targets, while an emissions cap instrument is cost-effective at lower policy targets. For CO2 emissions reduction, an emissions cap instrument is found be cost-effective for all policy targets. There is a trade-off between emissions levels and supply costs when the two instruments are co-implemented.

Browse

Browsing UHCL Faculty Works (Abstracts Only) by Title