bluuebunny/crossref_metadata_2025 huggingface dataset:
IL-10 signal transduction and its influence on prostate cells
Authors:   , Liu Anjiang , Stearns Mark E.
Published: July 2024

Interleukin-10 (IL-10) is a cytokine whose many functions have attracted wide attention from immunologists and cancer researchers. One area that has not been investigated was the role of IL-10 in prostate cancer. Surprisingly, we discovered that IL-10 stimulated human PC-3 ML prostate cancer cell proliferation, indicating it may play an important role in the regulation of cell growth and/or survival. Following IL-10 treatment, differential RNA display analysis revealed that IL-10 upregulated follistatin production in PC-3 ML cells. Follistatin binds to activin, a growth inhibitory molecule, to support cell survival. We have examined whether IL-10, follistatin or activin play an important role in the growth and cell survival of primary prostate cell lines derived from normal, benign and malignant prostate tissues. IL-10 and follistatin independently stimulated the proliferation of these three cell lines. Activin failed to support cell growth and flow-cytometry cell cycle analysis showed that activin induced apoptosis in these cells. IL-10 and Follistatin both blocked activin's apoptotic effects. Many studies have suggested that IL-10 activated STAT signaling controls gene expression in human macrophages and B cells. In contrast, our studies revealed that IL-10 down regulated STAT 1 and STAT 3 signaling in PC-3 ML cells, indicating a novel IL-10 signaling pathway might be involved in control gene expression in prostate cells (i.e. follistatin). In sum, the work reported in this thesis has shown for the first time that IL-10 regulates follistatin expression in prostate cells. The mechanism of action of IL-10 is unknown, but may involve down regulation of STAT 1 and STAT 3 expression. This study also revealed, a novel autocrine/paracrine regulation system (follistatin and activin) and IL-10 might regulate cell growth and apoptosis in prostate cells.
The effectiveness of different career decision-making behaviors
Authors:   , Singh Romila , Greenhaus Jeffrey H
Published: July 2024

This study enhances our understanding of effective career decision-making by focusing on the consequences of engaging in particular career decision-making behaviors. More importantly, the study explores the consequences of simultaneously engaging in different career decision-making behaviors. In addition, the study examines the reasons for the effectiveness of different decision-making behaviors. Three career decision-making behaviors are examined in the study: rational decision-making behavior, intuitive decision-making behavior and dependent decision-making behavior. In the present study, person job fit is used as the criterion to gauge effective career decision-making behavior. The data were gathered on 124 professionals working in a large pharmaceutical company who had recently made a decision to change jobs. A job change decision was defined to include a change in job title and a change in job responsibilities. The results suggest that the effectiveness of each decision-making behavior is contingent on the presence of other decision-making behavior. Specifically, an effective decision is made when individuals engaged in extensive levels of both rational and intuitive decision-making. The reason for this is attributed to the enhanced levels of self and environment awareness that result from this particular combination of decision-making. Similarly, the effectiveness of dependent decision-making was found to be contingent on the presence of either rational or intuitive decision-making behavior. Dependent decision-making was found to be more effective in the presence of extensive rational or intuitive decision-making behaviors than in the absence of these behaviors. The reason for the effectiveness of a combined dependent and rational decision-making approach as well as dependent and intuitive decision-making approach was due to heightened levels of self and environment awareness. The study empirically confirmed the reasons why different career decision-making behaviors are effective. Self and environment awareness served a useful function in explaining the reasons for the effectiveness of decision-making behaviors. The study developed several new measures for career decision-making that were specific to working adults engaged in making career decisions. All of these measures were found to be highly reliable. The findings of the study provide a contemporary view of career decision-making and make a contribution to the literature on career development and person-job fit.
Low frequency, large amplitude behavior of metal electrode polarization
Authors:   , Moussavi Maryam , Sun Hun H , Schwan H. P.
Published: July 2024

Historically, the study of the dynamical behavior of polarized metal electrode interfaces have been restricted to the linear range, i.e. small signal analysis over a narrow band of frequencies. The difficulties in collecting frequency response data over a wide range of frequencies and input amplitudes were mainly due to limitations of instrumentation. Advances in digital measurement technology and the evolution of the linear and nonlinear systems engineering field (time and frequency domain analysis) motivated us to apply these new tools to the study of interfacial polarization at frequency ranges well below 10 Hz. First part of this dissertation describes a computer based measurement technique implemented in our laboratory for automated data collection and processing over 4 decades below 10 Hz. Nonlinear data are presented to demonstrate the impedance gain compression phenomena and harmonics distortion of the Pt electrode immersed in physiological saline. Our results show that the behavior of the interface is linear for a certain range of frequency, AC amplitude, and clamped DC bias. The onset of nonlinearity is monitored in each of the above cases. For the first time the harmonics distortion as a product of nonlinearity are calculated and are used to check the validity of the only two models which have been proposed for explaining the dynamics of the interface in the nonlinear range.
Predicting juvenile recidivism and validating juvenile risk factors in an urban environment
Authors:   , Marczyk Geoffrey R. , Heilbrun Kirk
Published: July 2024

This study attempted to validate the risk factors associated with juvenile recidivism, which would provide an empirical basis for identifying risk factors, and improving prediction of juvenile recidivism in an urban environment. Its primary purpose was to investigate juvenile recidivism prediction as a function of the static and dynamic risk factors identified in the literature on juvenile recidivism by integrating three psychometric instruments (the PCL:YV, the MAYSI, and the YLS/CMI) into a classification and prediction model. Although not part of the original design, this study also examined the predictive relationship between these instruments and certification status, previous involvement with the juvenile justice system, and the number and severity of the charges brought against each participant as part of the decertification process. The results consistently demonstrated that there was little relationship or predictive utility between recidivism and any of the independent variables used in this study. Conversely, the results of this study data consistently demonstrated a relationship between certification status and a number of the independent variables used in this study. These results suggested that these variables and instruments might be useful in distinguishing participants who were decertified from those who were not, and for predicting certification status. Similarly, the results of this study suggested that these variables might be useful in distinguishing participants with past involvement with the criminal justice system, and for predicting such past involvement. The final areas of inquiry for this study was whether the PCL:YV, YLS/CMI, and the MAYSI possessed utility as predictors of violent charges/offenses and total charges. The results suggested that there is little utility in using these instruments to predict violent or total number of offenses. Generally, the results of this study do not support the direct use of the PCL:YV, YLS/CMI, and MAYSI for predicting recidivism, or for distinguishing between individuals who recidivated and those who did not. Results of this study do, however, lend significant support for the use of these instruments for indirectly assessing recidivism risk, and directly in the decertification process and for predicting previous charges. There was little support for the use of these instruments to predict violent crime or total charges. In conclusion, this study provided some empirical support for the use of these instruments in the juvenile justice system. The study demonstrated that these instruments have some utility in predicting certification status, which could be indirectly related to recidivism or dangerousness. Similarly, the results of this study support both the actuarial and dynamic risk factor approaches to risk assessment and classification.
Modeling of thermo-mechanical behavior of work rolls in steel rolling
Authors:   , Lin Fong-Han , Tseng Ampere A.
Published: July 2024

In the modern high-speed rolling mill, the severe thermal and mechanical loads in the work rolls have been identified as the critical factors in the problems of excessive roll wear or spalling. While thermal stress is induced by the large temperature gradient near the thin surface layer of the work roll, the mechanical stresses are caused by compressive forces both in the bite region and in the contact region of the work roll with the backup roll. These stresses frequently lead to local plastic deformation in the work roll, which will shorten roll life and affect rolled product quality. In this thesis, an integrated computer model has been developed for the investigation of thermo-mechanical behavior of work rolls in high speed strip rolling processes. Three numerical submodels are integrated for predicting complex phenomena associated with thermal-mechanical behavior in the rolling processes. Formulations of each submodel are presented, and examples, as well as results, are given to compare with existing solutions to demonstrate the feasibility and capability of the model developed. The first submodel, ROLLING, can be used to estimate the roll pressure, roll torque, deformation energy, and friction energy. The second submodel, RSTROL, can be used to evaluate the temperature distribution in both the roll and strip. The third submodel, EPTC, predicts the thermoelastic-plastic and/or contact stresses induced by the temperature and the roll-separation forces to the work roll. A typical condition of steel rolling is adopted to investigate the thermo-mechanical behavior of the work roll in rolling processes. The results show good agreements with available published data. This investigation not only demonstrates the capability of the model developed but also provides quantitative information to explain the roll spalling and the thermal crown behavior this will eventually lead to improve the roll life and the product shape quality.
Genetic regulation of long-term non-progression in E-55+ murine leukemia virus infection
Authors:   , Panoutsakopoulou Vassiliki
Published: July 2024

Certain inbred mouse strains display long-term survival after infection with E-55+ murine leukemia virus (E-55+MuLV) while others progress to lymphomas rather rapidly. This difference in disease progression occurs despite the fact that E-55+MuLV causes persistent infection in both BALB progressor (P) and C57BL long-term non-progressor (LTNP) mice. The goal of the studies in this thesis is to identify genetic loci and the functions mediated by these loci that are important in determining the LTNP phenotype. Immunosuppressed mice from P and LTNP strains develop lymphomas, indicating that LTNP is probably mediated by the immune system. Studies with bone marrow chimeras demonstrated that genes that determine the LTNP phenotype are expressed in donor bone marrow and not the recipient microenvironment. E-55+MuLV infection, in both the P and LTNP strains, is characterized by an acute and a persistent phase. During the acute phase, both P and LTNP mice demonstrate an initial increase in virus titer followed by a dramatic decrease in virus burden that occurs about two weeks after infection. Both P and LTNP mice require CD4+ T cells to mediate the decrease in virus burden but only P mice require CD8+ T cells as determined by in vivo depletion analysis. Moreover, during this phase of infection, both P and LTNP mice produce IFN-[gamma] whereas only P mice produce IL-4. IL-4 production in P strains results in the absolute requirement for CD8+ T cells to reduce the virus burden during the acute phase, whereas production of IFN-[gamma] is necessary for the development of the anti-virus CD8+ T cell response. On the other hand, LTNP strains do not produce IL-4 and do not require IFN-[gamma] to generate an effective immune response that reduces virus burden during the acute phase of infection. Backcross analysis of this phenotype suggests that more than one gene is responsible for these differences. Two candidate regions which may encode these genes, located on chromosome 7 and 19 respectively, were identified by recombinant inbred strain linkage analysis. During the persistent phase of infection, virus levels rise only in P strains and these mice progress to T cell lymphomas. Previous studies demonstrated that there is a difference in the cellular immune response between P and LTNP mice. Genetic studies on backcross mice show that there are two genes that regulate LTNP. Linkage analysis reveals that one of these genes is located on chromosome 15 (p = 0.00005) at the same region as the Rfv-3 gene. Rfv-3 is involved in recovery from Friend virus-induced leukemia and has been demonstrated to regulate neutralizing virus antibody titers. Previous studies, however, demonstrate that both P and LTNP strains produce similar titers of neutralizing anti-E-55+MuLV. Therefore, Rfv-3 may determine an influence on retrovirus infection that has not previously been described or these effects may be regulated by a closely linked gene.
Pretraining and shelving of neural networks by fourier analysis and their use for target classification
Authors:   , Melendez Gerardo J. , Kesler Stanislav B.
Published: July 2024

This effort was motivated by a problem of present and practical interest, namely, the classification of targets using radar data. The multi layer perceptron (MLP) neural network and its associated Back Propagation Algorithm (BPA) were proposed as a solution because of the expected payoff in robustness to some radar parameters such as dwell time. In so doing, the limitations associated with the BPA, such as the well documented long training time, had to be dealt with. The method proposed to reduce the training time of the BPA partitioned the training process in 2 steps, pretraining and final training. A network was first pretrained using one of four approaches. Final training then consisted of: (1) changing the topology of the pretrained network to accommodate the requirements of the specific target classification problem and; (2) training the network to classify the targets using the BPA. The final training step departed from the typical practice of initializing the weights of the MLP randomly. Instead, initial weights for the final training were obtained at the end of the pretraining process. The pretraining process trained a network to recognize a set of basic signal components that form the target's signature. If the basic signal components are selected independent of any specific target set, then the pretrained network can be shelved for future use against different target classification problems. For the specific problem of target classification by radar, the Fourier basis was proposed as the set of basic signal components. components. The objective of the pretraining process was to train the network to recognize sinusoids. Four pretraining approaches were developed to perform the spectrum estimation function. The algorithms for two of those approaches were tested against simulated signals. One of the two algorithms was used to classify aircraft using radar data. The performance of that one approach was compared to the performances of the baseline BPA and of an enhanced baseline that augmented the BPA by initializing the weights in a different fashion. The results indicate that the pretraining approach was effective at reducing the training time. Other benefits were also noted.
Investigation of mechanisms of hepatitis B virus (HBV) carcinogenesis in HBV transfected HEPG2 cells
Authors:   , Livezey Kristin Wallace , Simon D
Published: July 2024

Hepatitis B virus (HBV) is a major etiological factor associated with hepatocellular carcinoma (HCC) but its exact role in the transformation process remains unclear. Among several possible mechanisms it has been proposed that HBV functions directly or indirectly in HCC by promoting instability and chromosomal aberrations in hepatocytes. Recent reports suggest that the HBV DNA spanning the open reading frame that encodes the HBX protein interacts with several DNA repair factors and compromises the cell's ability to repair damaged DNA. The work summarized in this thesis was designed to explore the overall question whether or not the introduction and replication of HBV affects the genetic integrity of the host genome as measured by the identification of genetic alterations and HBV status in the host cell. First, we used three hepatoblastoma cell lines of the same genetic origin: the parental HepG2 cells, free from HBV virus, and its two HBV transfected variants-HepG2T14.1, with integrated non-replicating virus, and HepG2215, with integrated and actively replicating virus. We monitored genetic alterations in these cells in conjunction with HBV profile in vitro and in vivo to address the effect of HBV and its replication status on the integrity of the host genome. Our work demonstrate additional genetic changes at the chromosome and molecular levels in both HBV transfected cell lines that are not found in the original HepG2 cell line. Both HBV transfected variants developed tumors in nude mice within three weeks in contrast to parental HepG2 cells that did not form tumors in nude mice at that time period. A new HBV integration site was identified in HepG2215 cells replicating HBV while HepG2T14.1 cells maintained one stable HBV integration site. Further genetic alterations as well as clonal selection of particular changes were detected in both HBV transfected tumor derived cell lines. These data provide evidence that genomic integrity was affected in both HBV transfected variants and suggest that HBV and viral replication in the host cell is associated with enhanced genetic instability. We next investigated HepG2 transfectants with stable expression of the HBX gene to determine if expression of HBX gene is associated with genetic alterations in the host genome. We document HepG2 cells expressing the HBX gene have enhanced chromosome damage consisting of an increased number of chromosome rearrangements and micronuclei formation compared to their vector controls. This data provides cytogenetic evidence that genomic integrity was affected in cells expressing the HBX gene and implicate HBX in the process that leads to genetic alterations. Together, these results support the hypothesis that HBV, in particular HBY, may indirectly play a role in cellular transformation by interfering with normal cellular processes responsible for maintaining genomic stability, promoting the accumulation of genetic alterations and increasing the probability of neoplasia.
The effect of serotonin 5-HT2 receptor antagonists on classical conditioning of the rabbit nictitating membrane
Authors:   , Welsh Scott , Harvey John A
Published: July 2024

Psychedelics such as D-lysergic acid diethylamide (LSD), which act as agonists at 5-hydroxytryptamine2 (5-HT2) receptors, significantly accelerate the rate of learning in classical conditioning of the rabbit's nictitating membrane (NM) response. However, the effects of 5-HT2 receptor antagonists have not been extensively studied in this paradigm. The goal of this study was to characterize the effects of 5-HT2 receptor antagonists on NM response conditioning and to examine the behavioral mechanisms by which they produce their effects. Since both the 5-HT2A and 5-HT2C receptor subtypes have been implicated as potential targets for psychedelic drug action, antagonists with different affinities for these sites were used. Ritanserin, a fairly selective antagonist for both 5-HT2A and 5-HT2C receptors, impaired CR acquisition, increased the threshold for responding to the tone CS and reduced the magnitude of the UR without altering the threshold for eliciting URs. Ritanserin also blocked the ability of LSD to enhance the rate of CR acquisition to both tone and light CSs, but did so at doses that, by themselves, impaired CR acquisition. Thus, physiologic antagonism could not be ruled out. However, these would be the anticipated results if ritanserin was acting as an inverse agonist or antagonizing a tonic level of endogenous serotonergic activity. In dose response studies, ritanserin and the selective 5-HT2A receptor antagonist, MDL-11,939, significantly decreased the rate of learning in a dose dependent manner. LY-53,857, an antagonist with reportedly greater affinity for the 5-HT2C receptor had no significant effect on learning. Control experiments indicated that ritanserin, MDL-11,939 and LY-53,857 had no effect on baseline responding or responding to nonreinforced tones. However, both ritanserin and MDL-11,939 (but not LY-53,857) significantly reduced the magnitude of URs on US alone trials. To examine further the effects of these drugs on motor function, dose response studies were carried out using six 5-HT2 receptor antagonists to examine drug effects on both the US threshold for eliciting URs and on the amplitude of the elicited UR. Ritanserin, MDL-11,939 and mianserin significantly reduced UR magnitude while LY-53,857, ketanserin and BOL had no significant effect. However, none of the 5-HT2 antagonists changed US threshold. Altogether, these studies suggest that many 5-HT2 receptor antagonists impair associative learning by impairing the performance of both the CR and UR. These findings are consistent with theories suggesting serotonin probably acts as a modulator in both motor and sensory systems.
Stress-deformation behavior of footing foundations
Authors:   , Qubain Bashar S. , Martin Joseph Paul
Published: July 2024

A rational method for studying the fundamental aspects of the stress-deformation behavior of footing foundation systems on sand is proposed. This method incorporates a newly developed constitutive model which captures the single most important aspect of soil behavior in general, and sand in particular: the increase in stiffness due to confinement. This unique property makes soil stronger under certain applied loads. The constitutive model is based on the results of isotropic compression tests. It traces the increase in stiffness due to loading by describing the instantaneous bulk modulus in terms of the effective mean stress or volumetric strain levels and two hyperbolic constants, namely the initial bulk modulus and the ultimate volumetric strain. The nonlinear stress-strain relationships of the proposed constitutive model are incorporated into a comprehensive finite element analysis procedure for footing foundations. The solution process starts by calculating the initial state of stress for each element and performing a linear elastic analysis. Due to the linearization errors, the strains and stresses based on equilibrium will not agree with the nonlinear isotropic stress-strain relationships. This results in unbalanced loads. The solution is repeated using a combined incremental-iterative method until the equilibrium condition and the isotropic material stress-strain relations are simultaneously satisfied. Verification of the proposed constitutive model and analysis procedure is achieved by: (1) simulating the stress-strain curves generated in isotropic compression tests; (2) modeling two-, and three-dimensional systems of small-scale, strip and spread footings and checking the predicted settlements against the experimentally measured ones; and (3) comparing the analysis findings with elasticity-based finite element as well as traditional settlement prediction methods.
Mechanism of action studies defining the activity of the biguanide-based, human immunodeficiencey virus type 1 co-receptor inhibitor NB325
Authors:   , Rivera Nina Thakkar , Krebs Fred C
Published: July 2024

Our preclinical microbicide development efforts have focused on NB325, which was produced through studies of the biguanide-based compound polyethylene hexamethylene biguanide (PEHMB). Preliminary experiments designed to determine the mechanism by which NB325 inhibits HIV-1 infection suggested the involvement of the viral co-receptors, CXCR4 and CCR5. A number of in vitro assays were used to document the impact of NB325 exposure on CXCR4 and CCR5 detection and function. Flow cytometric assays using antibodies with distinct epitope specificities were used to probe changes in CXCR4 and CCR5 detection induced by NB325 exposure. Competitive binding assays with the sole CXCR4 ligand, CXCL12, and peptides derived from extracellular domains of CXCR4 were used to examine interaction specificity. Inhibition of CXCR4-induced chemotaxis was also assessed. These mechanistic studies demonstrated that NB325 altered the detection of CXCR4 on primary human memory CD4+ T lymphocytes in an epitope-specific manner. Differential detection of CXCR4 epitopes after NB325 exposure was consistent with inhibition of CXCL12-induced chemotaxis, no effect on CXCL12 binding, and a lack of CXCR4 internalization induced by NB325. Peptide competition experiments supported the hypothesis that NB325 interacts with CXCR4 extracellular loop 2 (ECL2). Further analyses demonstrated that NB325 persistently inhibited X4 HIV-1 infection and that mechanisms that provide immediate protection from infection also operate to provide antiviral memory activity and extended inhibition of CXCR4-induced chemotaxis. Similar studies involving CCR5 indicated that CCR5 detection was increased in an epitope-independent manner despite effective inhibition of R5 HIV-1 infection. Interestingly, NB325-induced changes in CCR5 detection were dependent on cellular stimulation. NB325 also conferred antiviral memory activity against R5 HIV-1 infection using a mechanism that also resulted in persistent elevation of CCR5 detection. Collectively, these findings indicate that NB325 provides immediate and persistent protection from X4 and R5 HIV-1 infection through interactions with CXCR4 and CCR5 that perturb their functions as HIV-1 co-receptors during virus attachment and entry into host cells. In conclusion, NB325 functions as a dual co-receptor inhibitor with immediate and memory antiviral activity against HIV-1.
Customer loyalty in interactive media
Authors:   , Ponnavolu Kishore , Anderson Rolph Ely
Published: July 2024

Historically, loyalty research has primarily been focussed on measurement issues around loyalty to a brand and the investigation of the antecedents of customer loyalty has been somewhat sketchy. This is especially true for customer loyalty in electronic commerce which is expected to grow from nothing in 1995 to $1 trillion in 2003-05 (OECD Report 1999), there is very little empirical research. In order to address this paucity of research, the current study has been constructed in four modules. In the first essay, the factors contributing to the changing loyalty context in electronic commerce relative to the conventional market are conceptually examined. In the second essay, the impact of business level variables in determining the loyalty of the customer to a Web site is evaluated. This study also ascertains the impact of loyalty on the actual behaviors of the customers. In the third essay, the current study examines the variables that moderate the relationship between satisfaction with a Web site and loyalty to the site. Finally, in the fourth essay, the mediating role of individual variables on loyalty is examined. These four essays together make theoretical contributions to our understanding of customer loyalty in electronic commerce by introducing new variables and models of loyalty. This study uses a two step methodology. First, a qualitative study was conducted for the model development. This model was then tested by using a cross-sectional design. A survey was used to collect the data and the sample was split into three groups. The first group was used to conduct exploratory factor analysis, the second to conduct confirmatory factor analysis and to test the predictive validity of the scales, and the third to validate the model and test the hypotheses.
Developing combination strategies for the treatment of spinal cord injury utilizing ex vivo gene therapy and alginate encapsulation
Authors:   , Tobias Christopher Alan , Murray Marion
Published: July 2024

Spinal cord injury (SCI) affects between 10,000 and 20,000 people each year in the United States. Most of these patients are left with motor and/or sensory dysfunction that limits their recovery. At the present time there is no treatment to repair the injured spinal cord or restore lost function. In the last decade, preclinical studies with transplants of stem cells and non-neural primary cells in combination with gene therapy have offered much promise for treatment of SCI. One of these therapies, ex vivo gene therapy utilizing primary fibroblasts genetically modified to secrete brain-derived neurotrophic factor (BDNF) or neurotrophic-factor-3 (NT-3), have been shown to be a successful strategy for stimulating regeneration, rescuing axotomized brainstem neurons, and eliciting behavioral recovery in adult rodent models of acute SCI. These studies were performed by grafting cells that secrete only one neurotrophin, which targeted a specific spinal tract that was injured. The goal of this thesis is to explore the capacity for combining therapeutic approaches utilizing genetically engineered fibroblasts to maximize neuron survival, regeneration and behavioral recovery for the treatment of acute and chronic SCI. Chapter 2 introduces this theme by showing that retroviral producer cell titers could be significantly increased by the addition of an inhibitor of histone deacetylase (trichostatin A) to an infection protocol. Chapters 3 and 4 show that grafting a combination of BDNF and NT-3 producing fibroblasts after a 6-week delay into the injured adult rat SCI site partially rescues axotomized Red nucleus neurons from loss and atrophy, provides a permissive environment for growth of chronically injured host axons, but elicits only modest recovery of function. Chapters 5 and 6 show that BDNF-producing fibroblasts that have been encapsulated in a semi-permeable alginate poly-L-ornithine membrane survive in culture for at least two months, remain viable after freezing in liquid nitrogen, create a permissive environment for host axons growth after grafting into the acutely injured spinal cord, and elicit behavioral recovery in tests of vertical forelimb exploration (cylinder test) and hindlimb function (rope test) in the absence of immune suppression. These results, utilizing a combination approach, demonstrate the diverse way in which engineered fibroblasts and alginate encapsulation can benefit the acutely and chronically injured adult spinal cord and provide evidence for their usefulness in treatment of human SCI.
Development of microfermenter chip
Authors:   , Kim Jong Woo , Lee Young Hee
Published: July 2024

Fermenters are used widely in biotechnology industry to grow cells and obtain information on their metabolic behavior, which is essential for developing industrial processes. To obtain such data in a short time, it is advantageous to run many fermenters concurrently. However, the capital and the operating costs become very high. The microfermenter chip developed in this work is intended to collect process data just as in a regular fermenter but at a much reduced cost. The microfermenter chip looks just like any other integrated circuit chip except that the chip has one or more well-instrumented micro-scale fermenters on it. Each fermenter is a bit smaller than a dime in size and has micro-scale sensors for measuring dissolved oxygen, pH, glucose, and cell density. These sensors are made from thin films of metals and dielectric materials, and are located at the bottom of the microfermenter. The sensors of the microfermenter were characterized in terms of measurement range, linearity, and stability. The micro pH sensor showed a linear response in the pH range of 2 to 10 with a slope of approximately -50 mV/pH at 20[degrees]C in an air saturated medium. The micro pH sensor showed good long term stability. The sensitivity of the pH sensor decreased as the oxygen level in the medium decreased. The micro DO sensor showed a linear response to partial pressure of oxygen. The micro glucose sensor was designed to operate in a kinetic regime, and the sensor showed a non-linear response. Cell density was measured by a micro interdigitated capacitance sensor which showed a linear response to cell concentrations. The capacitance was measured with varying depth of yeast solution from 0.5 mm to 1.5 mm. The capacitance was reduced with increasing the depth of yeast solution. It was demonstrated that the micro sensors were capable of measuring process variable in a batch fermentation.
Design and implementation of a two-port microstrip test fixture for complex permittivity characterization and near field imaging of biological materials up to 50 GHz
Authors:   , Tofighi Mohammad-Reza , Daryoush Afshin S.
Published: July 2024

Interaction of electromagnetic fields with human tissues, particularly the brain, is of great interest in omnipresent wireless communications. A field analysis (e.g., FDTD) requires knowledge of the complex permittivity of tissues exposed to the electromagnetic radiation. However, broadband complex permittivity values of biological tissues above 20 GHz obtained from direct measurements have not been reported in the literature. This thesis presents design and measurement results of a two-port microstrip test fixture for complex permittivity measurements of biological tissues up to 50 GHz. The test fixture uses aperture coupling for interaction with the tissue. Performance of the test fixture is modeled using a commercial finite element package. The simulated S parameters of the test fixture, obtained for various complex permittivity values, are fitted to a function similar to the pole-zero expansion of the transfer function of a linear system. The fitting procedure is computationally more efficient than the previously developed fitting methods. A two-port TRL method is selected to remove the measurement systematic errors. An Anritsu 37397C network analyzer is used for measurements from 5 to 50 GHz and the complex permittivity of white and grey brain matters is obtained for the first time up to 50 GHz. The results show very good agreements with previously reported results at 35 GHz. They also suggest that modifications to the available Cole-Cole models, extrapolated from the measured results below 26.5 GHz, are necessary. Small artifacts are seen due to the lack of repeatability of coaxial to microstrip launchers. Two correction methods, which utilize water (i.e., a known material) for correction, are introduced and successfully employed for removing these artifacts. Finally, the corrected results are fitted to a single term Cole-Cole relation for representing [gamma]-dispersion of white and grey matters up to 50 GHz. The test fixture design allows it to be used for near field imaging of brain slices. Such an image of a 1 mm thick sample slice immersed in saline is prepared. Qualitative (i.e., S₂₁ and quantitative (i.e., [epsilon][prime] and [epsilon][double prime], images are presented, and their resolution and contrast at various frequencies are discussed.
Human osteoblastic cell integrin expression, maturation and growth on tissue engineered matrices designed for skeletal regeneration
Authors:   , El-Amin Saadiq Farid , Laurencin Cato T.
Published: July 2024

The main objective of this study was to examine the molecular interaction involved in human osteoblastic cells seeded on biodegradable tissue engineered matrices, polylactic-co-glycolic acid (PLAGA) and polylactic acid (PLA) polymers designed for skeletal regeneration. Initial examination revealed that human osteoblastic cells isolated from trabecular bone were successfully obtained and grown on polymeric matrices both at relatively short and long-term periods. Examination of cells at the molecular level revealed, human osteoblastic cells adhered through their known adhesion receptors, integrins, with a higher rate of expression being controlled by the matrices polymeric composition and surface properties. In addition, studies on the extracellular matrix molecules (ECM), in which the integrins adheres to, were confirmed to be produced by osteoblastic cells seeded on matrices at various rates as well. Studies on blocking integrin adhesion receptors, via antibodies specific to the subunits, and peptides (RGD and RGE), revealed that initial cellular adhesion is dependent on integrin binding to key components of collagen ([alpha]2[beta]1) and fibronectin ([alpha]5[beta]1) molecules, respectively. Long-term growth of these materials revealed that human osteoblastic cells were able to grow, maturate and produce a mineralized matrix from collagen and proteoglycan constituents. In addition, studies on optimizing the PLAGA matrix into a 3-Dimensional microsphered matrix to resemble bone revealed that human osteoblastic cells were able to fully attach, grow, maintain their phenotypic behavior as well as a cytoskeletal (actin) framework throughout the material. During, in vivo analysis of this matrix in 15 mm non-union defect model in New Zealand White rabbits, osseointegration at the bone/implant site, integrin receptor formation and healing of the defect were observed and enhanced through providing a scaffold fabricated into an osteoinductive, osteocondcutive or osteogenic material. Overall, we feel that these studies have provided the area of tissue engineering of bone a better understanding of the molecular events involved in osteoblast adhesion, especially to novel polymeric matrices that are becoming more applicable in the fields of science and medicine.
Cloning and characterization of CSVTCG-specific receptor of thrombospondin-1
Authors:   , Zhou Jing , Tuszynski George P.
Published: July 2024

Thrombospondin-1 (TSP-1) is a 450 kDa glycoprotein involved in a variety of processes, including cell adhesion, tumor progression, and angiogenesis. Our laboratory previously showed that the CSVTCG sequence of TSP-1 functions as a tumor cell adhesion domain and CSVTCG peptides as well as an anti-peptide antibody had anti-metastasic activity in a murine model of lung metastasis. A novel tumor cell receptor was isolated from A549 human lung carcinoma by CSVTCG peptide affinity chromatography. A polyclonal antibody prepared against purified receptor stained human tumors and inhibited breast cancer progression both in vitro and in vivo. The full-length receptor cDNA was isolated from a lambda Zap-express prostate cancer cell (PC3-NII) cDNA library using the polyclonal receptor antibody. The full-length cDNA was then transferred from phage to a pBK-CMV vector and finally to a His tag expression vector. Recombinant receptor containing six histidine residues linked to the amino terminus was expressed in bacteria and isolated by Ni-chelation chromatography. The purified recombinant protein has a molecular weight of 60 kDa under reducing conditions and bound polyclonal receptor antibody, CSVTCG peptide and TSP-l. Recombinant protein (angiocidin) bound TSP-1 saturably with high affinity and specificity. To localize the region, we expressed truncated forms of receptor and examined their binding activity on TSP-1. Seven peptides were synthesized that spanned the active TSP-1 binding fragment. One of these peptides proved to have a higher binding activity than the others using the Affinity Sensor assay and ELISA competition assay. Our results suggest that the binding site resides in a small region FCTGIRVAHLALKHR between position 86 and 100 of the receptor molecule. Recombinant angiocidin specifically inhibited endothelial cell adhesion, and viability, while having no effect on a variety of cells including fibroblasts, smooth muscle cells, and tumor cells. Our results suggested that the site also resides in a small region between position 86 and position 100 of the angiocidin molecule. The TSP-1 binding site of angiocidin co-localized with the anti-angiogenic site. These experiments and other data from our laboratory should provide the basis for the development of this protein as an anti-cancer therapeutic.
Investigation of progressive collapse in precast concrete large panel buildings
Authors:   , Muskivitch John C.
Published: July 2024

The effects of joint details and joint behavior on the mechanism of progressive collapse in large panel precast concrete buildings was studied using small scale models and the finite element method. The adaptation of techniques to model the details of large panel buildings on a small scale is presented. Tests on 3/32 scale three story wall assemblies and a 3/32 scale-six story-three bay model, involved the removal of bearing walls to simulate the type of local damage which can cause progressive collapse in large panel structures. The results of these tests demonstrated the validity of applying the small scale techniques to the study of large panel buildings. The results identified and quantified the key aspects of the behavior in a damaged state. A finite element computer code was developed to include the types of finite elements which would aid in the modeling of the unique characteristics of joint behavior found in large panel buildings. Changes in the overall behavior of the joints through the loading history of a wall assembly above a damaged wall were incorporated in a nonlinear incremental analysis capability included in the computer code. The results of the experiments were compared to the finite element analysis of three different wall assembly models. The three finite element models were chosen as representative of the major behavioral aspects observed in the experimental models. From a comparison of the experimental and analytical results, the bond behavior of the joint reinforcement, the horizontal shear slip behavior of the horizontal joint, and the adequacy of the vertical support provided for a wall were found to be the critical aspects of the behavior. The proper design of details to control these aspects of behavior, through the use of design practices similar to those recommended by the Portland Cement Association is shown to contribute to the ability of the damaged struture to sustain simulated abnormal loading. The use of both the small scale modeling approach and the finite element method were successful in providing a more complete understanding of the nature and the internal mechanism of progressive collapse in large panel buildings.
Music in Images
Authors:   , Gupta Arjun , Artz Theo A
Published: July 2024

The development of the digital computer provides increasingly powerful means for automation of different processes. Today this development has reached a level that automation can even be applied in the production of forms of music, where the digital computer provides means of devising and implementing formal systems for the composition of music. While formal processes and algorithms have been utilized for centuries within the creative activity of music, the tools and technique of their application known as algorithmic composition. [5] This project offers an approach for generation of music (melody and chords) from digital images using their pixel values as input. The computer program reads an image and algorithmically assigns correlations between image pixel values. These values are then transformed into melody and chords, and music is produced using the computers audio interface.
An empirical evaluation of the legal assumption underlying workplace-based drug and alcohol testing
Authors:   , Messer Drew Carlson
Published: July 2024

A retrospective study of sequential non-random and random drug and alcohol testing programs used drug testing and treatment results and data on accidents, passenger and personal injuries for 16,000 employees at a large transportation agency (Agency) to evaluate empirically the legal assumptions underlying workplace based testing. During a four year period, employees identified as drug and alcohol users through testing and treatment averaged 139% more vehicular accidents than a matched group of employees not identified as users (6.58 vs. 4.73, respectively) and 173% more personal injuries (1.28 vs..74, respectively). Although the prevalence rate of psychoactive substance use, estimated by the number of employees identified as drug and alcohol users through testing and treatment over the total number of employees, declined by nearly 50% during the non-random testing program (1987 to 1989) and the subsequent random testing program (1990 to 1993), there was a 250% increase in the prevalence rate, from 2.1% in the final year of the non-random testing program (1989) to 5.2% in the first year of the random testing program (1990). Rates of vehicular accidents and passenger injuries for the workforce as a whole increased during the non-random program, but displayed decreasing trends during the random program. The results support the legal assumptions that drug and alcohol use is connected with harmful consequences in the workplace, that drug and alcohol testing is an effective means of addressing the problem, and that random testing is more effective than non-random testing.