bluuebunny/crossref_metadata_2025 huggingface dataset:
Consequences of limited palm incision carpal tunnel release
Authors:   , Michlovitz Susan L.
Published: July 2024

Carpal tunnel syndrome (CTS) can be treated carpal tunnel release (CTR) surgery, if conservative treatment has failed. Open (OCTR), endoscopic (ECTR) and limited palm (LP-CTR) are the categories of CTR. LP-CTR has not been studied with the rigor as OCTR and ECTR. Studies on CTR have not reported functional performance measures including finger dexterity and dynamic prehension. A within subjects, repeated measures design was used to examine whether LP-CTR use effective. A sample of convenience from one surgeon included 15 adults with CTS, age range 29-72, who underwent LP-CTR to ameliorate symptoms of CTS. Measurements were taken by one investigator within one month before surgery, at 4 to 5 weeks and at 10 to 12 weeks after surgery. Eleven of the 15 patients were also examined 6 to 9 months. Repeated measures or Friedman ANOVA tests revealed significant differences in pillar pressure-pain threshold, dynamic prehension, grip strength, chuck and lateral pinch strengths and patient-reported symptoms and function after LP-CTR. There were significant decreases in grip and pinch strengths and pillar pressure-pain threshold at 4-5 weeks. Symptoms severity decreased significantly from pre-operative to 4-5 weeks. Functional status improved significantly by 10-12 weeks. By 10-12 weeks, grip and pinch had not returned to pre-operative values, but did by 6-9 months. There were no differences in recovery between chuck and lateral pinch strengths. Dynamic prehension was above the pre-operative measure at 10-12 weeks after surgery. There was a positive trend (p >.05) toward improved finger dexterity by 10-12 weeks and continued at 6-9 months after surgery. Spearman correlation coefficients between pillar pain and grip strength and pillar pain and dynamic prehension were significant at 4-5 weeks after surgery, suggesting that pain can contribute to a decrease in physical performance. Reduction in numbness and improvement in dynamic prehension at 6-9 months (r =.67, p <.03), suggested that a decrease in numbness contributes to improvement in dynamic prehension. LP-CTR relieves primary complaints of numbness, tingling and pain in the fingers. Further study is needed to determine if a post-operative physical therapy within the first month after surgery will have an impact on recovery after LP-CTR.
Phosphorylation of transcription factor Sp1 by the ATM pathway modulates the cellular response to DNA damage
Authors:   , Olofsson Beatrix A. , Clifford Jane
Published: July 2024

The human genome is constantly threatened by cytotoxic and mutagenic lesions that can lead to genomic instability, cancer and/or cell death. These lesions include small or bulky modifications to DNA bases and sugars, inter- and intra-strand crosslinks, as well as single- and double-strand breaks. In order to avoid cell death or neoplastic transformation generated by DNA damage, the cell has systems in place to sense, signal and repair this damage in a timely manner, ensuring that daughter cells do not inherit a dysfunctional genome. The PI3-related kinases ATM and ATR play a major role in transducing the DNA damage signal, targeting a variety of proteins to engage cell cycle checkpoints, facilitate DNA repair, and promote cell survival. Specificity Protein 1 (Sp1), an essential metazoan transcription factor involved in the regulation of a wide variety of cellular promoters including housekeeping and stress-inducible genes, is a target of this DNA damage response pathway in normal human fibroblasts. Sp1 is rapidly phosphorylated in response to DNA damaging agents such as hydrogen peroxide, ionizing radiation and ultraviolet radiation. This phosphorylation is mediated by the ATM/ATR kinases. We have identified that Sp1 is phosphorylated on serine-101, which is located within a cluster of ATM/ATR consensus SQ/TQ sites. The kinetics of Sp1 phosphorylation and dephosphorylation parallel those of H2AX, a marker of double strand breaks. Following the induction of DNA damage, Sp1 becomes more tightly associated with chromatin, with kinetics that coincide with Sp1 phosphorylation. While Sp1 forms foci in response to DNA damage, they do not co-localize with phospho-H2AX foci, suggesting that Sp1 is not at the DNA damage site. When cells are depleted of Sp1 by RNA interference, they become more sensitive to the cytotoxic effects of H₂O₂ or IR exposure. Together, these data place Sp1 in the DNA damage response pathway, and suggest that Sp1 may be involved in mediating cell survival following genotoxic stress.
A longitudinal study of executive compensation
Authors:   , Wilson Alexander H. , Chiang Thomas Chi-Nan
Published: July 2024

This dissertation examines how executive compensation practice and theory has changed over the past 50 years. The data is primarily the Dow 30 industrial companies augmented and extended by a 900 firm five year contemporary data set. In a series of three essays, compensation levels, pay/performance sensitivity and determinants of CEO compensation is examined. Essay One finds that compensation levels have changed significantly both in total and by component during the study period. On a real, after-tax basis, compensation remained relatively stable from 1947 until the early 1980s, when a sharp upward trend began. The composition of compensation packages has significantly changed over the study period from salary domination to option domination. Compensation is consistently driven by firm performance when measured by market returns. Additionally, tax theories have significant explanatory value. CEOs have benefited extraordinarily from the series of tax rate cuts during the study period. Each significant cut created a permanent upward change in compensation. Contrary to prior literature, pay/performance sensitivity is generally consistent over the study period and shows signs of increasing in the most recent periods. A market driven definition of firm performance is most closely tied to compensation, but the neoclassical (accounting driven) and managerial (revenue growth driven) theories have historic periods of dominance. Compensation is most strongly determined by CEO tenure and CEO ownership and tax considerations. Macroeconomic factors have little predictive ability. The determinants have evolved over time and continue to show trend changes. I find significant inter-industry and firm size differences in the predictive model. Tax theory has significant explanatory power, although agency-alignment explanations of compensation are more consistently significant.
Frontal lobe system mediation of social problem solving
Authors:   , Small Michael , Williams Joseph M
Published: July 2024

The consequences of lesions in the frontal lobes of the brain include changes in personality, deficits in attentional mechanisms, loss of self control, and general inability to conceptualize, plan, and execute problem solving strategies. The present study compared a group of individuals with frontal lobe lesions (FL Group: N = 17) to a group of non-frontal lobe lesioned individuals (NL Group: N = 27) on measures of social problem solving: the Social Situation Vignettes (SSV: Small, 1994, unpublished), the Social Problem Solving Inventory - Revised (SPSI-R: D'Zurilla, Nezu, & Maydeu-Olivares, 1994), and the Frontal Lobe Personality Scale, Patient and Family report versions (FLOPS; Grace & Malloy, 1992). It was hypothesized that subjects from the FL group would be significantly poorer than those from the NL group at social problem solving, while, at the same time, over-rating their abilities in these areas. It was further hypothesized that a comparison between self and other reports on the FLOPS would demonstrate deficits among FL individuals in self awareness, with no such deficits seen in NL individuals. Results confirmed the hypothesized paucity in problem solving skills among the FL group. The study also found the expected negative correlation in FL subjects between prediction of success and actual demonstration of skills. However, unexpectedly, a similar negative correlation was demonstrated by the NL group members. Finally, results confirmed the hypothesized similarity between self- and other-ratings among the NL group, but failed to confirm the hypothesized disparity between self- and other-ratings among the FL group.
What mediates quality of life for the severely and persistently mentally ill?
Authors:   , Hartfield Cara Rose
Published: July 2024

Investigated were the factors that mediate quality of life in severe mental illness. Two models explaining the relationship between independent living skill, mood disturbance, psychotic symptoms and quality of life were tested. The first posits that protective factors such as treatment compliance and skill level will be reduced when mood disturbance increases, leading to an increase in psychotic symptoms and reduced quality of life. Another interpretation of the literature on severe mental illness and quality of life is that those clients with increased protective factors i.e. independent living skills and treatment compliance, have reduced mood disturbance, have reduced psychotic symptoms and improved quality of life. These models were compared with a null model indicating skill level, treatment compliance, mood disturbance and psychotic symptoms predict but do not mediate quality of life. Data was collected from a population of previously homeless severely mentally ill clients receiving supportive housing services. Structural equation modeling was used to test the described models. The partial path depicted by the hypothesized interpretations of the stress vulnerability model, that mood disturbance and treatment compliance impact psychotic symptoms and quality of life, was found to be significant. Support was also found for the hypothesis that skill level mediates the effect of mood disturbance on psychotic symptoms. However, none of the models were found to be a good fit for the data. The impact of missing data and measurement of the constructs is discussed.
Assessment of dynamic balance abilities in Pakistani children ages 5 to 13
Authors:   , Habib Zehra
Published: July 2024

Balance is a multifactorial ability, not the outcome of a single developmental sequence. A comprehensive balance assessment requires sensitivity towards cultural influences and biological competence. Differing environmental and social experiences can indirectly impact on motor and postural competencies of children belonging to different cultures. This study is the first to evaluate dynamic balance abilities from a functional perspective in Pakistani children. Additionally, the study looked at effects of gender, socio-economic status (SES), and anthropometric parameters on postural development of 180 Pakistani children. Children between the ages of 5 and 13 years were evaluated using the Functional Reach Test (FRT), Timed Up and GO (TUG), Running Speed and Agility (RSA) and Balance subtests of the Bruininks Oseretsky Test of Motor Proficiency (BOTMP). Demographic data, anthropometric parameters, and balance performances of Pakistani children are reported. These results were compared to published American values. Pakistani children were shorter in stature, and performed at a lower level of competence (maturity), in comparison to their American peers, on the FRT, RSA and Balance subtests of the BOTMP. Development of postural skills was noted as the children's age increased. There were significant differences in balance abilities of male and female Pakistani children belonging to low and high SES. In general males performed better on balance tests vs. females. The effect of gender was more pronounced in the high vs. the low SES. Significant correlations were found among the 4 balance tests of interest, especially between the TUG and RSA. Principle component factor analysis demonstrated that all 4 balance tests measure the same construct (assumed to be dynamic balance on face validity). After accounting for age, height and base of support seemed to be important variables in predicting the mean TUG and FRT scores of the Pakistani children in this sample. The findings of this research study indicate the importance of developing culturally sensitive norms, in order to get a true picture of a child's motor and postural ability. Therapists, therefore, need to consider the ethnic background of children, when evaluating their motor and postural competencies, so that they can better serve children from different cultural backgrounds.
The medical competency scale
Authors:   , Kennedy Colleen Marie , Williams Joseph M
Published: July 2024

The issue of competency to give informed consent to medical treatments arises frequently in medical settings. This study proposed a new method for assessing competency, the Medical Competency Scale (MCS). The MCS was developed to aid health care providers in the objective assessment of competency. The MCS consists of three vignettes that describe medical procedures, ranging from low risk to high risk procedures, followed by questions based on the legal standards of competency. This study was designed to explore the psychometric properties of the MCS. One aspect of validity was studied by comparing the MCS to standardized neuropsychological tests of attention, memory, reasoning, judgment and abstract reasoning. The literature suggests that these areas of cognitive functioning are necessary for individuals to make competent decisions. Results of this study indicated that the MCS is a reliable measure of competency and has good inter-rater reliability. The MCS was found to be a valid measure of competency to give informed consent, and results suggested that the MCS is a better measure of competency than the Mini Mental State Exam. Although it has been suggested that competency should be measured on a continuum, with decisions regarding high risk procedures demanding greater cognitive abilities than low risk procedures, this study did not support this notion.
The effect on users' understanding of alternative attest reports on investment managers' compliance with performance presentation standards
Authors:   , Rexer Marianne Scicchitano
Published: July 2024

In recent years, accountants have performed attest services and provided reports on information other than financial statements. The American Institute of Certified Public Accountants has promulgated attestation standards under which accountants can report on whether investment managers' and their firm's performance reports comply with the Performance Presentation Standards (PPS) of the Association for Investment Management and Research (AIMR). The first purpose of this research is to examine users' perceptions of an attestation report on an investment manager's compliance with the PPS. While compliance with the PPS is mandatory, the investment manager engaging a third party to attest to his or her compliance is voluntary. Additionally, the PPS do not prohibit a firm from attaching to its report additional information not examined by the accountant. As a result, report users may not understand precisely what information was and was not examined and attested to by the accountant. In order to inform users as to what was and was not examined by the accountant, a disclaimer on the unattested information may be included in the attestation report. The second purpose of this research is to examine whether a disclaimer on additional composites or a disclaimer on additional schedules influences users' perceptions about the additional composite or schedules being in compliance with the PPS. The research indicates that the attestation report has an effect on users' perceptions that the performance presentation is in compliance with the PPS as well as on the decision to engage the investment manager who presented the performance report. The research also indicates that there is a negative signal sent out by a disclaimer on additional composites or schedules. However, the research indicates that there is an interaction effect between the disclaimer on additional composites and the disclaimer on additional schedules.
Analysis of the high nitric oxide and high eosinophil phenotypes in the brown Norway rat
Authors:   , Gabrea Ana Irina , Blankenhorn Elizabeth P
Published: July 2024

Lewis (LEW) and Brown Norway (BN) rats are used as animal models for human diseases such as multiple sclerosis and metal ion-induced autoimmunity. In vitro studies conducted with these rat strains showed that (1) BN splenic T cells have a low proliferation response to superantigens and mitogens compared to LEW splenic T cells and (2) the low T cell proliferation phenotype in the BN splenic cultures correlates with the ability of the BN splenic macrophages to produce uniquely high levels of nitric oxide. The regulation of high nitric oxide levels, and the genetic basis for this regulation, are questions addressed in my dissertation project. I have determined that the high nitric oxide production in purified BN macrophage cultures corresponds to higher levels of mRNA for the inducible nitric oxide synthase (iNOS) and that stability of the iNOS mRNA is similar for LEW and BN. Microsatellite analysis conducted on (LEWxBN)xBN backcross rats allowed me to (1) map three loci on chromosomes 8, 19 and 20 that influence the high nitric oxide phenotype and (2) determine that this phenotype is not linked to the structural iNOS gene on chromosome 10. Analysis of the LEW and BN iNOS promoters and coding regions, together with the mapping data, suggest that cis-regulating elements are not involved in the regulation of the nitric oxide difference between LEW and BN. As possible candidates for trans-regulation of the nitric oxide difference, IFN[alpha]/[beta] and TNF[alpha] were analyzed. Results show that (1) IFN[alpha]/[beta] remains a good candidate for regulation of the nitric oxide difference between LEW and BN and (2) TNF[alpha], although necessary for nitric oxide production, does not contribute to the high nitric oxide phenotype. I have identified a novel phenotypic difference between LEW and BN rats. Specifically, naive BN rats display high numbers of eosinophils as compared to naive LEW rats. Genetic analysis using the (LEWxBN)xBN backcross, led to the identification of a strong suggestive locus on chromosome 2 associated with this phenotype. The high nitric oxide and high eosinophil phenotypes coexist and are regulated by distinct genetic factors. Both phenotypes may have direct relevance to the susceptibility of LEW and BN rats to autoimmune diseases.
Current-sensitive magnetic resonance imaging technique
Authors:   , Pinus Alexander B. , Faro Scott H. , Tretiak Oleh John , Mohamed Feroze B
Published: July 2024

This work investigates the theory and ascertains an experimental feasibility of the current-sensitive magnetic resonance imaging technique, a method to study various human physiological functions. The method's physical principles are based on non-invasive magnetometric detection and measurement of weak magnetic fields originated from electrical currents, which could be of an electrochemical origin. Such current-induced magnetic fields manifest themselves through an interference with nuclear magnetism. The infinitesimal deviations of precession rates produced by these interactions affect the generated magnetic resonance signal and result in specific imaging artifacts which can be employed as endogenous markers of the original currents. The following original theoretical results were obtained: (1) the relations between the amplitude of the original electrical currents and related magnetic resonance signal; (2) the expressions for the sensitivity limit given as a function of the most essential parameters and characteristics of the imaging system, such as echo time, reception band-width; (3) the description of the technique sensitivity dependence on system's static magnetic field strength. These results led to predictions of the system- and imaging protocol-specific lowest detectable currents. The experimental trials with various imaging protocols confirmed the important role of the echo time. To achieve the utmost sensitivity, in a novel approach the "spiral" imaging protocols specifically tailored to target lower electrical currents were employed. Another significant result was attained in comparative experiments on imaging systems with different static magnetic field strengths. It was shown for the first time, both theoretically and experimentally, that the higher field strength decreases the detection sensitivity, and that higher amplification gains of the detection electronics can be used to compensate for such sensitivity losses. Overall, this work establishes the basis of the proposed current-sensitive magnetic resonance imaging technique and contributes its design, theoretical and feasibility considerations to the knowledge base of the methods aimed towards non-invasive detection and assessment of human neuronal functions. It is hoped that the proposed methodology will have an eventual effect in the field of neuroscience in general and in the study of human neuronal functions in particular.
The role of hepatic lipase in the delivery of high density lipoprotein cholesterol to cells in culture
Authors:   , Bamberger Mark
Published: July 2024

Human HDL was incubated with rat hepatic lipase and subjected to compositional analysis. 30% of the HDL phosphatidylcholine was hydrolyzed by hepatic lipase but no change was detected in apoprotein content of the HDL compared to HDL incubated with heat-inactivated hepatic lipase. Cultured Fu5AH rat hepatoma cells exposed to hepatic lipase-modified HDL showed an increased uptake of HDL free cholesterol relative to cells exposed to control HDL. The increased delivery of HDL was dose-dependent, and could be demonstrated by both isotopic and mass determinations. The enhanced cellular accumulation of HDL free cholesterol observed with hepatic lipase was directly related to the extent of phosphatidylcholine hydrolysis, and appears to be due to the phospholipase activity of this enzyme, since similar results were obtained with HDL that had been modified with snake venom phospholipase A(,2). To investigate the mechanism of this response, the influence of hapatic lipase on the metabolism of other HDL components relative to free cholesterol was determined. Experiments utilizing doubly-labeled HDL ([('14)C]free cholesterol. ('125)I-labeled HDL) demonstrated that the mechanism does not involve an enhanced uptake and degradation of the entire lipoprotein molecule. The delivery of HDL phospholipid, as sphingomyelin, was also unaffected by the action of hepatic lipase. Hepatic lipase-modification does stimulate the incorporation of HDL cholesteryl ester, as measured by the uptake of either [('3)H]cholesteryl ester or the nondegradable marker, [('3)H]cholesteryl ether; however, this response is minor when compared to the amount of HDL free cholesterol that was transported into the cell. Only one-tenth of the HDL free cholesterol incorporated by the cell as a result of the modification of HDL by hepatic lipase could be attributed to the stimulated delivery of cholesteryl ester. In an attempt to correlate the events observed at the cellular level with lipoprotein structure, nuclear magnetic resonance spectroscopy was employed. Modification of HDL by either hepatic lipase or phospholipase A(,2) generated a movement of free cholesterol molecules from the core of the lipoprotein to the surface. These results indicate that HDL which has been modified by hepatic lipase preferentially delivers free cholesterol to cells by a surface transfer process and support the hypothesis that hepatic lipase may modulate the delivery of cholesterol to the liver.
Genetic determinants of susceptibility to herpes simplex virus encephalitis in the murine host
Authors:   , Richardson Angela , Blankenhorn Elizabeth P
Published: July 2024

Herpes simplex virus type 1 (HSV-1) is a ubiquitous pathogen. This double-stranded DNA virus commonly infects people, but only rarely causes a severe life-threatening encephalitis. The host innate immune system initiates the early response to infection and is crucial for protection from herpes simplex encephalitis (HSE) in both the murine and human host. Toll-like receptors (TLRs) are pattern recognition receptors that are activated in response to conserved pathogen motifs. A role for HSV-1 ligation of TLRs 2, 3, and 9 has been observed with stimulation of these pathways providing protection and inhibition leading to susceptibility to infection. Like TLRs 2 and 3, TLR7 senses nucleic acids in the endosome; however, a role for this receptor has not been established in HSV-1 infection. Here we show that murine susceptibility to HSE is dependent on TLR7 dose. We infected B6. Yaa mice bearing two genomic copies of TLR7, wild-type B6 mice with one copy of TLR7, and B6. TLR7 -/Y mice with no copies of TLR7 both peripherally in the footpad and intracranially. B6. Yaa mice were resistant, B6 mice exhibited an intermediate phenotype, and B6. TLR7-/Y mice were susceptible to these infections. Surprisingly, the Yaa-mediated protection that we observed was not associated with decreased viral load, but was associated with a decreased early inflammatory response. This is the first example of natural TLR7 overexpression providing protection from an infectious agent. Upon activation of pattern recognition receptors, interferons are produced and exert antiviral effects. Tyrosine kinase 2 (Tyk2) is an adaptor molecule that transduces signals from the type I interferon receptor into the cell. We utilized mice with different alleles of Tyk2 to assess the effect of diminished signaling through this pathway on HSE susceptibility. Mice bearing the mutant Tyk2 allele were susceptible to HSE at doses ranging from 1 x 10 6 PFU to 1 x 107 PFU, while mice bearing the wild-type allele were more resistant at these same doses. Thus, a single nucleotide change is sufficient to increase HSV induced mortality. These data demonstrate the importance of the innate immune system and control of inflammation on susceptibility to HSE.
A new method for evaluating the structural characteristics of biological and artificial joints
Authors:   , Nobilini Robert James , Siegler Sorin
Published: July 2024

The purpose of this study was to develop a new method for evaluating the relationship between load and displacement in biological structures. The method developed centers on a six degree of freedom instrumented linkage device. This device allows for the application and measurement of loads and displacements in the same reference frame without constraining the structure being tested. Loads and displacements are measured and described with respect to three rotational and three translational parameters28, which can be easily renamed with clinically terminology to make data clear to clinicians as well as engineers. This method was applied in two different ways to human joints. First, three joint flexibility testers were developed for the ankle, knee, and cervical spine. Second the feasibility to using this method to simulate artificial joints for wear testing was examined. The joint flexibility testers were designed, fabricated, and used in a number of studies. The Ankle Flexibility Tester (AFT) was found to have positional accuracy of better than 1.2[degrees] in rotation and 0.5 mm in translation. Intraclass Correlation Coefficients (ICC's) calculated from test-retest data for 13 young, healthy subjects tested several days apart indicated that the AFT has a reliability higher that 0.85. A similar study on the Neck Flexibility Tester (NFT), performed on 12 healthy subjects showed the reliability of the NFT, in measuring flexibility, to be good to excellent with ICC values ranging from 0.57 to 0.97 with an average of 0.83. These devices were used to study the flexibility of joints under various conditions. The studies demonstrated the ability of these devices to detect differences in flexibility. A numerical model of a Universal Joint Simulator (UJS) was created with Adams, a dynamic simulation software. This model was used to evaluate the usefulness of the newly developed method to simulate a hip joint for wear testing. Displacement and loading data was digitized from the literature4,31 and used to simulate a hip joint through a single gait cycle. Load requirements for the rotational and translational actuators were determined from the model. The development of this model was a good first iteration through the design process and will be useful in the future development of an actual UJS.
Reliability and third party informants
Authors:   , Philipson Judith , Heilbrun Kirk
Published: July 2024

This study addressed the use of third party information in criminal forensic assessment. The perceptions of direct care staff in a forensic hospital regarding the genuineness of patient symptoms were explored. Staff (N = 108) were asked to rate eight case vignettes in which the patient variables of prior psychiatric history, cooperativeness with staff, and inconsistency across observations were systematically manipulated within a 2 x 2 x 2 within-subjects design. Results indicated that prior psychiatric history and behavioral inconsistency were significantly related to staff perceptions of symptom genuineness, but uncooperativeness was not.
Physical-chemical mechanisms of the reaction of ozone with aquatic humic substances
Authors:   , Chrostowski Paul C.
Published: July 2024

The purpose of this investigation is to assess the nature of the interactions of ozone with aquatic humic materials. Specifically, the validity and use of ozone in water treatment for humics removal, definition of concepts and terms used in ozonation practice, control of the process, the importance of mass transfer, and the chemical properties of the humics were investigated. The major avenue of approach was to follow changes in different parameters as a function of time of ozonation in a heterogeneous reaction matrix. These includes non-specific measurements of substrate concentration such as ultraviolet absorbance, dissolved organic carbon, and particle size; products of ozonation such as carbonyl compounds and phenolics, and ozone concentration. Reactions were conducted with natural humics, analogs and model compounds. These included soil humic acid, soil fulvic acid, lignosulfonic acid, and several low molecular weight phenolic type compounds. The results indicate that classical rate laws could be used to describe the reactions. All the reactions could be separated into three mechanisms: slow, reaction rate limited; slow mass transfer limited;, and fast mass transfer limited. The importance of ozone decomposition, presence of inhibitors, and voltilization was also demonstrated. Rate curves were used to differentiate between oxidative coupling and degradative mechanisms. The information derived was utilized as input to a protocol for design of water treatment facilities utilizing ozone for organics control. The conditions of ozonation were defined such that control over the process and reproducibility of results could be ensured.
Polymer materials as modified optical fiber cladding for chemical sensors
Authors:   , Yuan Jianming , El-Sherif Mahmoud
Published: July 2024

An intrinsic fiber optic chemical sensor has been designed and developed by using a polymer material as a modified fiber cladding. The sensor is constructed by replacing a certain portion of the original cladding with a chemically sensitive material, specifically, polyaniline or polypyrrole. Both the light absorption coefficient and the refractive index of the polymers change upon the exposure to different chemical vapors. These changes induce the optical intensity modulation of the fiber optic sensor. Polyaniline or polypyrrole is coated as the modified cladding by either spin-cast or in-situ deposition method for sensing HCl, NH3, H 2O2, and H4N2 vapors. All sensors show rapid and strong response to the chemical vapors. Thus, these sensors demonstrate that polyaniline and polypyrrole are viable candidate materials for the detection of volatile toxic gases. Sensors exhibit better performance when correct parameters, such as modification area, in-situ deposition time, and spin-rate, are used in the cladding modification process. The reversibility of the sensor depends on the reaction between the modified cladding material and the chemical vapors. Polyaniline cladding has better reversibility than polypyrrole. The optimized sensor response and sensitivity can be achieved by selecting an incident light with suitable wavelength, power, and incident angle.
A combustion kinetic model for refuse derived fuel in fluid bed boilers
Authors:   , Smith Stephen Vaughn , Cernansky Nicholas Peter , Miller David Leslie
Published: July 2024

A modelling study of the combustion kinetics of refuse derived fuel (RDF) in fluid bed boilers is presented. Refuse derived fuels are significantly different from traditional fuels due to a larger fraction of volatile matter and a lower carbon content. As they are derived from waste, their composition varies widely. RDF also has a significantly shorter total combustion time than traditional fuels. The devolatilization behavior of RDF during combustion is key to understanding the overall kinetics. A mathematical model is presented for the prediction of the devolatilization behavior of RDF based on the individual component devolatilization behavior. The individual component devolatilization behaviors are correlated as mean apparent activation energies determined from thermogravimetric analysis. The model is solved in a FORTRAN computer program and describes the RDF devolatilization within the range of experimental results. A method to estimate the RDF moisture, volatile matter, fixed carbon, ash, and heating values is presented for alternative levels of preprocessing of waste material. Results are given for various levels of removal of metals, glass, paper and plastic. A combustion kinetic model which incorporates the devolatilization model for a single particle of RDF is presented. The model predicts the time-temperature behavior for RDF particles with widely varying compositions. The mathematical model has been solved in a FORTRAN computer program and the results are compared to a limited set of pilot plant data. For small particles (1/4 gram), the model predicts the pilot plant RDF combustion times within 5% for total combustion time, 9% for fixed carbon burnout time, and 18% for drying and devolatilization time. A method is presented to scale-up the combustion kinetic model for larger particles to full scale fluid bed combustion conditions and results are estimated for larger particles.
Stress distribution and bearing stiffeners details related to fatigue and fracture of steel girders with corrugated webs
Authors:   , Rodriguez Roberto , Elgaaly Mohamed
Published: July 2024

The use of corrugated webs in steel girders has been shown to be an innovative, economical and structurally adequate solution to premature web stability failure. It allows relatively thin webs without the need for welded stiffeners. The elimination of welded stiffeners reduces the fabrication cost and increases the fatigue life of the beams. A reasonable number of investigations have been carried out to study beams with corrugated webs under static loads, however minimum work has been done to describe the behavior of this type of beams under repeated cyclic loads. These limited results clearly showed that beams with corrugated webs sustain longer fatigue lives than conventionally stiffened beams. A need, therefore exists for conducting experimental and analytical studies that would demonstrate the potential of beams with corrugated webs under fatigue loads. This thesis investigates the fatigue life of these beams analytically and experimentally. A total of six girders with trapezoidal corrugation were tested under cyclic loads; the main parameters were the stress range at the top of the bottom flange, the stiffener type and location. The experimental program showed that, from the fatigue standpoint, the best stiffener detail is a single plate stiffeners on both sides of the inclined fold, welded to the top flange and web and cut short from the bottom flange. More importantly, the experimental results exhibited a fatigue life 2.6 times longer than the one calculated for a conventionally stiffened beam under the same stress range. Finite Element Methods were used to analyze the state of stresses in beams with corrugated webs. This analysis showed two critical areas susceptible to fatigue failure: (a) the bottom flange at the web fold line and (b) the center region of the inclined fold. In addition, Fracture Mechanics in conjunction with Finite Element Models were used to develop logarithmic equation that would approximate the fatigue life of beams with corrugated webs; good agreement between the experimental results and this formulation was observed.
Selection criteria for potential wholesaler-distributors
Authors:   , Tripuraneni Ravi
Published: July 2024

The primary objective of this study is to understand the selection criteria that manufacturers use in selecting their potential wholesaler-distributors. Alpha factor analysis reduced the large data set used in the descriptive study to eight dimensions. The eight dimensions (variables) considered important (in order of decreasing importance) by the manufacturers in the selection of wholesaler-distributors are: (1) distributor sales resource, (2) distributor credibility, (3) distributor functional participation, (4) distributor promotional participation, (5) distributor financial strength, (6) distributor external credibility, (7) distributor market coverage, (8) distributor similar/competitive product practices. Preliminary findings indicate that middle level managers, top level managers and sometimes a committee comprised of top, middle and field personnel from sales, marketing and finance are involved in the selection of potential wholesaler-distributors. Field sales personnel (typically salespeople) and trade sources are the two most widely used sources of information for locating potential wholesale-distributors. In this study, policy capturing is used to identify the policies of the twenty four decision makers (raters). All the policies are statistically significant (p < 0.01). The results also validate the usefulness of multiple regression analysis as a technique for capturing the policies of the decision makers. Judgment analysis (JAN) answers the question of the existence of a single policy or several policies among the raters in the selection of wholesaler-distributors. In this study, the results of judgment analysis show the existence of a single policy among the raters in the selection of potential wholesaler-distributors. Results from MANOVA validate the hypothesis that personal variables of the rater (age, sex, educational qualifications, professional experience, position in the company, income) have no effect on the selection of potential wholesaler-distributors. The importance of proper selection policies has been highlighted in literature. The findings from this study can be used to improve the selection process used by the manufacturers in selecting their wholesaler-distributors. The selection techniques and methodology used in this study can be easily adopted to other areas where selection is involved such as: (1) selecting personnel, (2) selecting managers, (3) selecting faculty in colleges and universities, (4) selecting credit worthy loan applicants.
Multi-sensor fusion system using wavelet based detection algorithm applied to physiological monitoring under high-G environment
Authors:   , Ryoo Han Chool , Hrebien Leonid , Sun Hun H
Published: July 2024

A significant problem in physiological state monitoring systems with single data channels is high rates of false alarm. In order to reduce false alarm probability, several data channels can be integrated to enhance system performance. In this work, we have investigated a sensor fusion methodology applicable to physiological state monitoring, which combines local decisions made from dispersed detectors. Difficulties in biophysical signal processing are associated with nonstationary signal patterns and individual characteristics of human physiology resulting in nonidentical observation statistics. Thus a two compartment design, a modified version of well established fusion theory in communication systems, is presented and applied to biological signal processing where we combine discrete wavelet transforms (DWT) with sensor fusion theory. The signals were decomposed in time-frequency domain by discrete wavelet transform (DWT) to capture localized transient features. Local decisions by wavelet power analysis are followed by global decisions at the data fusion center operating under an optimization criterion, i.e., minimum error criterion (MEC). We used three signals acquired from human volunteers exposed to high-G forces at the human centrifuge/dynamic flight simulator facility in Warminster, PA. The subjects performed anti-G straining maneuvers to protect them from the adverse effects of high-G forces. These maneuvers require muscular tensing and altered breathing patterns. We attempted to determine the subject's state by detecting the presence or absence of the voluntary anti-G straining maneuvers (AGSM). During the exposure to high G force the respiratory patterns, blood pressure and electroencephalogram (EEG) were measured to determine changes in the subject's state. Experimental results show that the probability of false alarm under MEC can be significantly reduced by applying the same rule found at local thresholds to all subjects, and MEC can be employed as a robust system to the case of defective/jammed local sensors. This implies the feasibility of our system for physiological state monitoring under a unifying criterion by biological information fusion, and provides significant guidance for algorithm development.
Modes of action of two newly identified interferon-induced antiviral proteins, IFITM3 and GBP5, against vesicular stomatitis virus infection
Authors:   , Weidner Jessica , Guo Ju-Tao
Published: July 2024

Type I interferon (IFN-[alpha]/[beta]) plays an essential role in eliminating, or at the very least, controlling the severity of, viral infections in vertebrates. Treatment of cells with IFN-[alpha] typically induces hundreds of IFN-stimulated genes (ISGs) which work cooperatively to inhibit virus infections. However, only a handful of these ISGs have been implicated in direct antiviral action. In our search for novel IFN-induced proteins that may mediate the antiviral function of the cytokines against flaviviruses, we discovered that GBP5, a member of the IFN-induced guanylate binding protein (GBP) family, and IFITM2 and IFITM3, members of the IFN-induced tramsmembrane (IFITM) protein family, were able to inhibit infection of two medically important flaviviruses, West Nile virus and dengue virus, upon expression in HEK293 cells. In order to dissect their antiviral mechanisms, we further demonstrated that GBP5, IFITM2, IFITM3, as well as another recently identified IFN-induced antiviral protein, tetherin (BST-2), potently inhibited vesicular stomatitis virus (VSV) infection. Using this well-studied virus infection system, we showed that the antiviral activity of GBP5 relies on its putative GTPase activity, as well as its putative isoprenylation sequence. In addition, we provide strong evidence suggesting that GBP5 inhibited VSV genome replication, but not virus binding and entry into host cells. In contrast, we found that while both IFITMs and tetherin are plasma membrane proteins, IFITMs inhibited VSV infection by disrupting virus entry into cells, while tetherin inhibited virion particle release from infected cells. Through our mutagenesis studies, which involved the shuffling of structural domains between IFITM3 and IFITM1, we discovered that both the N-terminal 21 amino acid extension and C-terminal transmembrane region of IFITM3 are essential for its antiviral activity. The mutagenesis strategy was determined based on the observation that IFITM1 did not elicit an antiviral activity against VSV, yet shares 70% amino acid identity with IFITM3. In conclusion, our work reveals the distinct antiviral mechanisms of two newly identified antiviral ISGs, whose novel function will help to better understand how the innate immune system works to control of virus infection.
Sensor concepts for polymer injection molding
Authors:   , Thomas Charles Landreth , Rose Joseph L. , Tseng Ampere A.
Published: July 2024

In order to increase the economic competitiveness of injection molding, the process is analyzed to identify areas where either the process capability or efficiency can be improved. While several avenues for improvement are identified, it is noted that each possibility requires, or would be augmented by automated techniques to monitor both the state of the polymer during processing and final product quality. This is only possible with new sensor technology. Hence new concepts and techniques in a number of different sensing areas are explored, including ultrasonic sensing, optical sensing, fluorescence based sensing, and pressure sensing. Changes in the reflection factor of a transient ultrasonic pulse at the polymer/mold interface are exploited giving the ability to sense mold filling, flash, and shrinkage in the mold. The sonic velocity in the polymer during solidification demonstrates sensitivity to temperature and pressure. Features of this signal indicate the cooling rate and the moment of gate seal. Two fluorescent dyes are investigated that, when doped at low concentration into the polymer, provide the ability to monitor both the temperature and solidification state during molding. The emission of one dye clearly indicates the glass transition in an amorphous polymer. The second dye responds smoothly to changes in temperature, without directly indicating the glass transition. In a semi-crystalline polymer, these dyes are sensitive to the heat of crystallization generated upon crystallization. An optical sensor is developed that is sensitive to the formation of the crystal morphology in a semi-crystalline polymer of low optical density. Features of this signal indicate the formation of skin, the end of primary crystallization, and the average crystallinity of the finished part. The physical basis for sensor signals are demonstrated using a process model. This model is used to interpret and explain correlations between observed features of the sensor signals and process milestones such as gate seal or final solidification. Finally, the application of these sensors to process control is discussed. An example application is demonstrated using a cavity pressure transducer and ultrasonic transducer to monitor and control the hold time setting.
The role of paradox in behavioral change
Authors:   , Weber Phil
Published: July 2024

The purpose of this dissertation is to investigate the role of paradox in behavioral change. The vehicle used for this investigation is the comparison of two theories which utilize contralogical and paradoxical means of behavioral change. Those theories are the analytical psychology of C. G. Jung and systems theory as it is applied to the behavioral sciences. Second order change, as described by systems theorists, and Jung's concept of transformation, both involve stepping outside the frame of competing and mutually exclusive choices to a conceptual meta-level where the duality and polarities of our existence can be acknowledged, recognized as complementary, and embraced. In analytical psychology, this superordinate level is the Self, which unifies conscious and unconscious aspects of our psyches. For systems theorists, the meta-level is the move to a higher logical typology through second order change. The processes to achieve this meta-level are illogical, "irrational," and paradoxical. Techniques which promote this type of change are compared and discussed.