bluuebunny/crossref_metadata_2025 huggingface dataset:
Three essays on empirical analysis of closed-end country fund price behavior
Authors:   , Lee Euiseong , Chiang Thomas Chi-Nan
Published: July 2024

In this dissertation, we investigate the time-varying behavior of country fund premiums and the pricing of country funds in the US market by applying monthly data of 37 single-country funds. Essay 1 provides empirical evidence on the relationship between closed-end country fund discounts and time-varying risk. We hypothesize that the existence, persistence, and time-variation in country fund discounts are attributable to the risk assessed on different countries by investors. We measure the risk with the conditional standard deviations from major macro-economic variables including stock returns, the change of exchange rates, inflation rates, real incomes, and interest rates. Empirical findings provide supportive evidence on the time-varying risk hypothesis. Among all the risk measures, the U.S. stock return volatility appears to be the most dominant risk factor in predicting the time varying country fund premium. Essay 2 analyzes the relationship between country fund returns and market factors, such as stock market return, fund premium (discount), and volatility in both US and foreign country. We also examine the impact of news (shock) variable from the US and foreign stock markets on the country fund pricing. The evidence shows that the US stock market returns and the previous level of fund premiums play significant roles in determining country fund prices. The evidence also indicates that the unexpected volatility of the foreign stock return has information content in explaining the country fund returns. Building on the empirical evidence derived from essay two, the third essay explores the nonlinear specifications of the country fund pricing to see if such linear multivariate models can be generalized by nonlinear behavior to capture a more comprehensive relationship among the variables. Our analysis shows that the hypothesis of linearity is rejected and there are at least several nonlinear variables that help explain the pricing of country funds.
Characterization of a functional DNA repair enzyme from Plasmodium falciparum that displays glycosylase and AP-lyase activity
Authors:   , Stumhofer Jason Scott , Vaidya Akhil B.
Published: July 2024

Throughout its residence within the red blood cell the malaria parasite must cope with a significant amount of oxidative stress that results in the increased production of reactive oxygen species. In order to prevent these reactive oxygen species from causing deleterious mutations to its genome the parasite must employ a number of effective strategies for repairing its DNA. We have characterized an Nth/Endonuclease III homologue protein in P. falciparum (PfNth) that effectively recognizes and excises oxidatively damaged DNA as part of the base excision repair pathway. A truncated PfNth [PfNth(s)] protein was produced in E. coli and shown to have both DNA glycosylase and AP-lyase activity specifically directed towards excision of oxidatively damaged DNA. Analysis of the PfNth genomic sequence from seven geographically distinct P. falciparum isolates revealed variations involving a ten amino acid sequence repeat present in the central portion of the protein, as well as a number of nonsynonymous single nucleotide polymorphisms. We tested the possibility that these sequence variations may affect the ability of individual strains to recognize and excise oxidatively damaged DNA thus contributing to the frequency with which drug resistance may arise. However, the biochemical activity of the truncated PfNth(s) from the isolates tested was not affected by the variations in the genomic sequence. In addition, the effect of exogenous oxidative stress on the transcriptome of the blood stage parasite was examined. The exogenous stress administered to the parasites came in the form of a known pro-oxidant antimalarial drug, artemisinin and an antimalarial drug, atovaquone, which we believe may act as a pro-oxidant. The compounds buthionine sulfoximine, which depletes intracellular levels of glutathione and glucose oxidase, which increases production of hydrogen peroxide, were also tested. We were specifically looking at differences in the transcript levels for genes whose products are involved in DNA repair and antioxidant redox systems. However, over a 4-hour period of treatment with the aforementioned compounds there were no significant changes in the transcript levels for any of these genes. In fact, there were no significant changes in the level of transcription for most genes during this 4-hour period. This is a strikingly different observation than what has been observed for other organisms, where gene expression changes occur within minutes in response to changes in growth conditions such as increased oxidative stress.
The role of protein kinase C in the regulation of gallbladder sodium transport during gallstone formation
Authors:   , Narins Seth C. , Abedin Mohammad Z
Published: July 2024

Background and aims. Gallbladder Na⁺ and water absorption increases prior to gallstone formation and promotes cholesterol nucleation. Na⁺/H⁺ exchange (NHE) is a major pathway for gallbladder Na⁺ transport. Data suggest that NHE activity is altered during gallstone formation and may be partly due to altered NHE regulation. Studies show that Ca²⁺-dependent second messengers, including protein kinase C (PKC), inhibit basal gallbladder Na⁺ transport. Multiple PKC isoforms have been reported with species and tissue-specific expression. PKC isoform expression and functional role in regulating gallbladder NHE are not known. This dissertation characterized gallbladder PKC isoforms and examined if increased Na⁺ absorption via NHE observed during gallstone formation is in part due to altered Ca²⁺-dependent PKC signaling pathways. Methods. Gallbladders were harvested from prairie dogs fed either nonlithogenic chow or 1.2% cholesterol-enriched diet for varying lengths of time to induce various stages of gallstone formation. PKC regulation of gallbladder NHE activity was examined by measuring unidirectional mucosa-to-serosa Na⁺ flux (J^[Na]_[ms]) and DMA-inhibitable ²²Na uptake, respectively. Gallbladder PKC activity was assayed by histone III-S phosphorylation under maximal stimulation conditions. PKC-[alpha] contributions were determined with Gö 6976, a PKC-[alpha] specific inhibitor. Gallbladder PKC isoform mRNA and protein expression were examined by Northern and Western blot analysis, respectively. Results. PKC activation significantly decreased GB J^[Na]_[ms] and reduced baseline apical ²²Na⁺ uptake. Prairie dog and human GB expresses PKC-[alpha], [beta]II and [delta] isoforms. PKC-[alpha] appeared dominant and mediated ~42% of total PKC activity under basal conditions. PKC-[alpha] regulates basal GB Na⁺ transport via NHE2 stimulation and NHE3 inhibition. PKC-[alpha] blockade significantly reversed (~45%) PKC-induced inhibition of J^[Na]_[ms] and reductions in NHE-mediated ²²Na⁺ uptake in controls but was progressively less effective during the various stages of gallstone formation. PKC-[alpha] contribution to total PKC activity was progressively reduced during gallstone formation. PKC-[alpha] mRNA and protein expression significantly increased (~60%) during gallstone formation. Conclusions. PKC-[alpha]-mediated regulation of gallbladder NHE becomes progressively dysfunctional during gallstone formation, paralleling a progressive loss of PKC-[alpha] phosphorylation activity, despite compensatory increases in mRNA and protein expression. Loss of PKC-[alpha]-mediated regulation of gallbladder NHE may in part account for increased Na⁺ absorption observed during gallstone formation.
Development of a zirconia toughed hydroxyapatite
Authors:   , Mager Carie Christine Wilkinson , Barsoum Michel W.
Published: July 2024

Because of its low fracture toughness (<1 MPa m^(1/2)) compared to bone (2-12 MPa m^(1/2)), the use of HAp in dentistry and orthopedics is limited to low load bearing applications. In order to broaden its applications, HAp was reinforced through the addition of partially stabilized zirconia. HAp composites with varying amounts of zirconia were processed using a 2 level, 8 variable factorial design to determine the effect of various processing conditions on the stability of the zirconia and HAp phases and on the resulting toughening behavior of the composites. The processing conditions included in the design were; a) milling times and fluid dispersion mediums; b) sintering times and temperatures in ambient air and atmospheric pressure; and c) hot isostatic pressing time and temperature in inert and "wet" environments. The effect of volume fraction and particle size of the zirconia in the range of 0-30 wt % and -0.9[mu]m to -2.0[mu]m respectively on the material's fracture toughness were also determined. The composites were also placed in a serum like solution for 6 months to study the effect of physiological environment on the various processing parameters and the resulting toughening behavior. The toughening behavior before and after in vitro exposure was monitored using micro Raman spectroscopy which enabled the size and shape of the transformation zone to, be quantified. The optimization of the design parameter's resulted in an increase in the fracture toughness by a factor of three and the six month in vitro study indicated that a zirconia toughened HAp implant could be processed so as to retain its hardness and toughness in vivo.
Use of international networks and databases to access U.S. scientific information from Japan
Authors:   , Liebergot Harris L. , Andriole Stephen J.
Published: July 2024

The development of high speed worldwide data communications capabilities and numerous online databases of scientific information will undoubtedly lead to more exchange of such information among the world's developed countries. Various factors will facilitate such exchanges, while others will act as barriers. This research work determines such factors within one of the world's premier high energy physics laboratories, located in Japan. The methodology used was a series of structured interviews with a significant number of the theoretical and experimental physicists in the facility. The results show that the physicists in this laboratory do access scientific information from the U.S. via computer networks. Significant factors are shown to be the researcher's work group, job position and age, and the availability of a database with appropriate information and facilities for full text hard copy. A number of other non-significant factors are also indicated.
An Interactive Media Platform for the Ski Industry
Authors:   , Marchesani Brian Thomas , Tedesco Albert S. , Salas Philip W.
Published: July 2024

It was in the 2010/2011 North American winter ski season that Vail Resorts Inc. debuted its newest technology development called EpicMix. Using RFID scanners attached to the top and bottom of lifts, combined with RFID chips embedded in lift passes, Vail resorts can automatically track a skier's or snowboarder's activity on the mountain and provide them a snapshot of their day through the EpicMix dashboard. This EpicMix Dashboard can be accessed online and through a mobile phone application and shows vertical feet skied and lifts ridden during the day. The platform also allows individuals to earn virtual pins and points and compete against the Vail Resorts community. The platform and use of RFID will not only potentially change the way ski resorts communicate with their guests, but also market and advertise to their guests. The goal of this thesis is to provide an in-depth analysis of some of the questions that may have arisen in the discussions concerning EpicMix's beta season. Who will use the platform, what are the initial reactions, are there any concerns with privacy, as well as what may happen in the future with the platform?
Disciplinary institutional infractions
Authors:   , Westendorf Melissa Jean
Published: July 2024

Violent criminal behavior and recidivism has been a growing concern for society. Institutions such as prisons or forensic hospitals are also concerned with violent behavior during inmate or patient confinement. Prisons and mental health facilities generally dedicate significant resources to maintaining institution safety. Prediction of violent and antisocial behavior has encountered mixed results. One of the most promising personality traits in the prediction of violent and antisocial behavior has been psychopathy. This study examined whether psychopathy, as measured by the PCL-R, could be useful in predicting institutional infractions, given the success of psychopathy predicting recidivism. In addition, this study investigated whether psychopaths commit more violent institutional infractions than nonpsychopaths. The study found that psychopaths, as measured by the PCL-R, do not commit significantly more institutional infractions than nonpsychopaths. In addition, this study demonstrated that psychopaths do not commit more violent institutional infractions than nonpsychopaths. This study indicates that the PCL-R is not a useful tool for classification, therefore the PCL-R is not a prudent use of institution resources.
The influence of physical therapists' attitudes, child's motor ability, and parenting stress on mothers' perceptions of family-centered care in early intervention
Authors:   , O'Neil Margaret E. , Palisano Robert J
Published: July 2024

This research project consists of three studies each examining components of the interpersonal aspects of care in early intervention. Rationale for this research is found in current health care, public policy, and pediatric physical therapy trends. The first study presents a research model to examine the influence of physical therapists' attitudes, child's motor ability, and parenting stress on mothers' perceptions of family-centered early intervention physical therapy. Twenty-five physical therapists and 75 mother-child dyads participated in this study. Results of multiple regression analyses indicated that parenting stress was the strongest determinant of mothers' perceptions of family-centered care. Therapists' attitude was a determinant to a lesser degree and child's motor ability was not a determinant of mothers' perceptions of care. The second study examined physical therapists' attitudes towards family-centered care and factors in clinical decision making. Twenty-five physical therapists working in early intervention participated. Results indicated that therapists had strong, positive attitudes towards family-centered care. Therapists considered child characteristics to be the most important category when determining frequency and duration of physical therapy services. Findings on clinical decision making suggest that therapists use a child-focused approach when determining levels of service. The third study examined the influence of child and early intervention factors on parenting stress for mothers of children receiving early intervention physical therapy. This study also examined the relationship between parenting stress and mothers' perceptions of family-centered physical therapy and the relationship between parenting stress and mothers' overall satisfaction with physical therapy. Eighty mother-child dyads participated. Results of multiple regression analyses indicated that a child factor was a significant determinant of child-related parenting stress and an early intervention factor was a significant determinant of parent-related parenting stress. Results of correlation analyses indicated a significant, inverse relationships between mothers' perceptions of family-centered care and child-related parenting stress and a significant, inverse relationship between satisfaction and child-related parenting stress. Overall, mothers had very positive perceptions of family-centered early intervention physical therapy and therapists had very positive attitudes towards family-centered care. Mothers were very satisfied with physical therapy. Findings suggest that therapy may be a protective factor for child-related parenting stress.
The significance of general locus of control beliefs, weight-specific locus of control beliefs and restraint in predicting binge eating behaviors in an eating disordered population
Authors:   , Kerzhnerman Irina , Lowe Michael R
Published: July 2024

Despite the fact that theoretical and diagnostic conceptualizations of eating disorders identify control beliefs as being integral to these disorders, there has been limited empirical investigation of the relationship between control beliefs and eating disordered behaviors. This study examined the significance of general locus of control, weight-specific locus of control beliefs, and dietary restraint in predicting binge eating behaviors in an eating disordered population. Participants included 154 females being admitted for inpatient treatment of eating disorder symptoms (Mean age = 25.14±8.21; Mean BMI = 18.91±4.42) and 30 female university students without eating disorders (Mean age = 24.33±9.74; Mean BMI = 22.86±4.82). Using analysis of variance and regression techniques, this study suggested that: (1) individuals diagnosed with Bulimia Nervosa-purging subtype (BN) endorse a more external general locus of control that individuals without any eating disorder diagnosis; (2) there is no difference between the weight-specific locus of control of individuals with and without eating disorders; (3) comparing between the eating disorder diagnostic categories, individuals diagnosed with BN endorsed the most external general locus of control beliefs, followed by individuals diagnosed with AN-binge/purge subtype and AN-restrictive subtype, respectively; (4) there is no statistically significant differences between the eating disorders on weight-specific locus of control; and (5) having a external weight-specific locus of control is associated with more frequent objective binge episodes. The results are discussed in light of previous research on control and on binge eating. Future directions for research in this area are suggested.
Afferent regulation of force-field primitives during real limb behaviors
Authors:   , Kargo William J. , Giszter Simon F.
Published: July 2024

Spinal interneurons may be organized into functional assemblies that form building blocks for constructing limb movement. Understanding how such assemblies are recruited and used to construct limb behaviors and how sensory feedback supports the operation of these assemblies represent important areas of research. A mathematical framework, which describes the motor output of spinal circuits as a force field, has been developed using the frog as a model preparation. Force-field measurements describe the combined action of a stimulated interneuronal assembly, an activated muscle synergy and sensory feedback across the configuration-space of the hindlimb. A small number of invariant force-field structures and associated muscle synergies were organized in the frog's spinal cord. The invariant field structures were termed 'force-field primitives'. Microstimulation studies showed that force-field primitives could be combined by vector summation and scaled in amplitude to produce a larger range of force-field patterns. It was hypothesized that force-field primitives might form stable building blocks for constructing more complex, natural limb behaviors. The first part of this thesis tests whether a reflex behavior, which is organized at the level of the spinal cord, is constructed by a combination of force-field primitives. The behavior examined is the hindlimb to hindlimb wiping reflex. This behavior requires coordination of muscle activation and of joint torques at the hip and knee to accurately move the endpoint of the hindlimb to a target and to remove the target. Several methods were used to decompose this behavior and correction responses during this behavior into a combination of primitives: (1) natural observations of primitive deletions, (2) perturbations to evoke primitive deletions/additions, and (3) statistical decomposition techniques. The second part of this thesis tests whether sensory feedback regulates the operation of individual primitives, the temporal pattern of primitive activation, and functional aspects of the behavior. Several methods were used including (1) whole-limb and selective deafferentation, (2) selective (muscle vibration) and whole-limb perturbations, and (3) single unit recordings of sensory afferents. The results of this thesis provide strong evidence that reflex behaviors are constructed from primitives and that sensory feedback scales the amplitude and regulates the phasing of primitive activation.
TEM Investigation of Ag Diffusion Mechanisms in [beta]-SiC Fuel Particle Materials
Authors:   , Coward Robert A. , Taheri Mitra L
Published: July 2024

The nuclear industry is on the verge of creating and implementing a new generation of reactors that are meant to be safer and more efficient. One of the new fuel designs utilizes tri-structural isotropic (TRISO) fuel particles. P-silicon carbide (SiC) is the main layer for metallic fission product retention in TRISO fuel particles. However, under the extreme environment of a nuclear reactor, these particles can fail with the release of fission products into the containment vessel of the reactor. There is a need for the tracking of these fission products in the SiC layer to provide support that it is a safe fuel type for a new generation of nuclear reactors. At these elevated temperatures, the only true way to determine the mechanism for Ag mobility is through the use of heating in situ TEM experiments. With this paper, we explore the advantages of using this powerful technique. In this study the microstructural evolution of the beta-sic layer is examined by ion implantation of Ag and annealing samples up to 1600 C. Under examination in the transmission electron microscope (TEM) faceted voids were observed around the Ag particles post-annealing. This gives way to the possible theory of a void mediated transport mechanism due to the change in microstructure of the beta-sic layer at elevated temperatures. In addition, the implanted Ag particles appear to agglomerate during annealing. It was found that the implanted Ag particles are mobile at 1000 C and their mobility appears to be driven by the recrystallization of the amorphized beta-sic.
Development and initial psychometric evaluation of the denial questionnaire for sex offenders
Authors:   , Malloy Cordella Denise , Nezu Christine M.
Published: July 2024

Clinical experts have indicated that individuals identified as perpetrators of sexual assault often deny their sex-offending behavior and that such denial hinders successful treatment. However, the construct of denial has not been systematically defined or examined empirically regarding its impact on treatment or risk of reoffense of sex-offending behavior. Recent research has produced evidence indicating that denial of sex-offending behavior may be amendable to treatment. Despite these findings, many treatment programs will not accept sex offenders who deny their sex offenses. This situation is unfortunate, in that those who deny their sex-offending behavior may be most in need of treatment. Terms such as distortion, minimization, and lying have been used interchangeably with denial, creating problems regarding consistency or replication of research findings. Moreover, the lack of a clear definition of denial in the sex offender literature continues to serve as an obstacle regarding treatment research. This project involved the development and initial psychometric evaluation of a denial questionnaire. The questionnaire is designed to provide an operational and systematic definition of denial, such that the construct may be studied empirically.
Spray forming of metal matrix composites
Authors:   , Majagi Shivanand I.
Published: July 2024

Spray deposition via the OspreyTM process is a potential technology for developing Metal Matrix Composites (MMCs). Advantages of this approach include a near net shape capability, fine scale microstructure devoid of segregation and a uniform distribution of the second phase reinforcement. In this study the fabrication of particulate reinforced MMCs was evaluated by injecting inert or reactive particles into metal spray droplets. A model has been developed to quantify criteria for the penetration of solid particles into the liquid droplets of the spray in the atomizing zone. This is of importance since the scale of the dispersion of reinforcement in the metal matrix is dictated by the extent to which solid particles penetrate the liquid droplets of the spray. The different forces considered in developing this penetration model are the surface tension, hydrostatic, gravitational and the retarding (drag) force. The model identifies particle droplet wettability, particle-droplet relative velocity, particle size and density, as key material/process parameters in determining the degree of penetration. An assessment of the penetration model was made using three different sprays (Cu, Cu-6w/o Ti and Fe-5w/o Ti) and seven species of injected particles (Cu, W, Al2O3, Ni-coated Al2O3, Ta, Fe-2.5w/o C and B4C). Resulting microstructure in the preform and the overspray particles were characterized in terms of the distribution of the reinforcing phase. Injection of cold inert or reactive particles into the liquid droplets alters the thermal condition of the spray. Thus the spray model was modified in order to quantify the effect of the injected particles on spray enthalpy. The modified model predicts the process parameters (melt superheat, gas:metal ratio) required in order to produce preforms with a minimum level of porosity.
The effects of prenatal exposure to cocaine on dendritic development evidence of targeting of specific cortical areas dependent upon neurotransmitter innervation
Authors:   , Jones Liesl Beth Kerns , Levitt Pat
Published: July 2024

Activation of dopamine receptors can cause differing effects on neurite outgrowth from cortical neurons. Since cocaine can bind to the transporters of these monoamines and thereby alter the available levels of these neurotransmitters during development, it may adversely affect the development of the cerebral cortex by changing the balance of the available monoamines during critical developmental time points. We have chosen to examine cortical areas based upon their different neurotransmitter innervation. This approach will allow examination of the effects of in utero cocaine exposure on general cortical development and more specifically, in specific areas. We will attempt to answer the question of whether cocaine adversely affects cortical development, based on the organization of neurotransmitter innervation. The cortical areas chosen had either a dense dopamine innervation, such as anterior cingulate cortex and medial prefrontal cortex, or a sparse dopamine input and a dense serotonergic innervation, visual cortex and somatosensory cortex. Using a variety of anatomical and biochemical methods, our results suggest that cocaine adversely effects the development and final structure of neurons in areas that receive a dense dopaminergic innervation. Our results suggest that cocaine affects dendritic development of pyramidal neurons in anterior cingulate and medial prefrontal cortex and not in the visual or somatosensory cortices. Alterations in function of these areas could lead to dramatic changes in cognitive function. (Abstract shortened by UMI.).
Investigation of the unusual tricarboxylic acid metabolism and mitochondrial electron transport chain functions in Plasmodium falciparum
Authors:   , Ke Hangjun , Vaidya Akhil B.
Published: July 2024

Tricarboxylic acid (TCA) metabolism in malaria parasites is poorly understood. We knocked out [alpha]-ketoglutarate dehydrogenase (KDH), succinyl-CoA synthetase (SCS), succinate dehydrogenase (SDH) and isocitrate dehydrogenase (IDH) genes individually. KDH/SCS and SCS/SDH were also knocked out simultaneously. Remarkably, none of the knockout lines exhibited growth defects, suggesting these enzymes are nonessential. The KDH/SCS double-knockout line indicated an unusual mode of heme biosynthesis. Fumarate hydratase could not be deleted, suggesting it is essential. We fed the knockout lines 13C-5N-glutamine and examined changes of TCA metabolites by mass-spectrometry. No significant changes in the TCA metabolites measured were found in the [delta]SCS line. [delta]KDH knockout lines contained lower levels of +4-13C-succinate and +4-13C-malate. [delta]SDH knockout lines produced higher succinate and lower +4-13C-malate levels. The [delta]IDH knockout line had lower levels of malate (unlabeled, +3-13C-labeled, +4- 13C-labeled), citrate (+5-13C-labeled), and succinate (unlabeled, +4-13C-labeled). These data suggest such changes in TCA metabolites do not affect parasite survival, indicating a high degree of metabolic redundancy in malaria parasites. Previous work has shown that the most important function of the mtETC (mitochondrial electron transport chain) in P. falciparum (D10 strain) is to provide an electron sink for pyrimidine biosynthesis. To investigate general applicability of this finding, we integrated a single copy the yeast DHODH gene into the genomes of D10, 3D7, Dd2 and HB3. The gene was equally expressed in all strains. All transgenic strains were highly resistant to atovaquone and DSM1 (P. falciparum DHODH inhibitor) in short-term assays. When exposed to atovaquone for longer periods, D10 and 3D7 transgenic parasites were able to survive, while Dd2 and HB3 transgenic parasites died after 3-4 days of exposure. No differences were found in the responses to DSM1. The ubiquinone analog, decylubiquinone, substantially rescued Dd2 and HB3 transgenic parasites during extended growth under atovaquone. These data suggest there are strain specific differences in the requirement for mtETC. It's possible that dehydrogenases in the mtETC other than DHODH are more essential in some strains than in others. Overall, our studies have discovered unique aspects of TCA metabolism and mtETC functions in blood-stage P. falciparum with the potential to inform drug discovery efforts.
Issues in public and private equity offerings
Authors:   , Marciukaityte Dalia , Szewczyk Samuel Hideyo
Published: July 2024

This study examines post-issue performance of public and private equity issuers. The samples of primary, combination, and secondary public seasoned equity offerings include offerings made during the period 1974 to 1997. The sample of private primary equity placements includes placements made during the period 1979 to 1994. Secondary equity issuers significantly overperform, while primary (public and private) and combination equity issuers underperform matching companies in the five year post-issue period. I find some support for the incorrect risk matching explanation of underperformance for public primary and combination equity issuers. The results are inconsistent with the predictions of investor overoptimism, the Barberis, Shleifer, Vishny (1998) investor sentiment model, and the Daniel, Hirshleifer, Subramanyam (1998) model. However, they are consistent with the representativeness heuristic. Also, the results show that abnormal performance is stronger when uncertainty is higher. Secondary equity issuers overperformance is stronger for smaller companies, issues made in December, and for issues in which sellers have strong reasons to sell the shares. Overperformance is smaller or does not exist for issues in which the seller is related to management. Post-placement performance is worse for companies with low book-to-market value, for companies with high standard deviation of earnings forecasts, companies with negative prior earnings, developing and distressed companies. The results are inconsistent with the hypotheses that in general private equity placements increase the value of company by providing quality certification or improved monitoring. Companies that have positive investor reaction to the placement announcement have even worse post-placement performance than other placing companies. However, the placements made to managers or significant shareholders seem to increase the company value. Positive investor reaction to the placement announcement followed by increase in the number of public equity issues and poor stock price performance suggest that, although incorrectly, investors may be believing that private equity placements provide quality certification.
Correlates of narcissism in committed couples
Authors:   , Colombo Diane M. , Lowe Michael R
Published: July 2024

The individual characteristics of a person within a relationship can positively or negatively affect the satisfaction of the couple as a whole. Empirical research and theory support the notion that there are negative effects of narcissism for the individual (e.g., hypersensitivity, hostility and decreased ability to resolve conflict via negotiation skills). Yet, there is little empirical evidence of the effect of narcissism within committed relationships. This investigation looked into the potential influence of narcissism, pathological and non-pathological, within the relationship. It tested the assumptions of its harmful effect on core aspects of relationships: the association of narcissism with intimacy, empathy and aggression. This study tested this association using committed couples. Results showed that for male narcissism, females perceived higher intimacy (i.e., intellectual intimacy) yet less emotional intimacy. For female narcissism, males perceived greater aggression. Empathy was not associated with narcissism in the predicted direction for either gender. It appears that narcissism does not have as pervasively a negative effect, although does have harmful aspects, on a couple's relationship as it was hypothesized. The effect appears to be determined by what aspect of the relationship one chooses to evaluate.
Studies on DNA photolyase from Escherichia coli and Saccharomyces cerevisiae
Authors:   , Lipman Richard Simon Adam
Published: July 2024

DNA Photolyase catalyzes the direct photorepair of the cyclobutane dimer between adjacent pyrimidines, the main product of DNA exposed to ultraviolet light. The native enzymes from both Escherichia coli and Saccharomyces cerevisiae contain a folate chromophore ( (6R) -5, 10-CH+-H4Pte(Glu)n, n = 3-6) and a fully reduced flavin (FADH2). In E. coli photolyase, the folate acts as an antenna to transfer light energy to the FADH2 at a high efficiency (EET=0.92). Apophotolyase reconstituted after an overnight incubation with (6-R,S) -5, 10-CH+-H4folate, a monoglutamate analog of the native cofactor) contains equimolar amounts of the [6R]- and [6S]-isomers, suggesting similar binding affinities. A rapid biphasic increase in fluorescence ([approx equals]100-fold) is observed upon binding of 5,10-CH+-H4folate to apophotolyase ar 5 [degrees] C; the [6S]-isomer binds about 25-fold faster than the [6R]-isomer. Although identical absorption and fluorescence emission maxima are observed for enzyme reconsitituted with [6R]-, [6S]-, or [6-R,S]-5,10-CH+-H4folate, folate fluorescence quantum yield values vary depending on the stereochemical configuration at the 6 position ([Phi]=0.82, 0.18, or 0.46, respectively, at 5 [degrees]C), a feature not seen with free folate. The fluorescence of enzyme-bound folate is quenched upon flavin binding; the quenching efficiency by flavin radical (EQ=0.96) or FADH2 (EQ=0.89) is the same for both folate isomers. In contrast, energy transfer from folate to FADH2 is sensitive to the stereochemical configuration at the 6 position. The efficiency of energy transfer observed for enzyme containing FADH2 and [6R]-, or [6S]-, or [6-R,S]-5, 10-CH+-H4folate (0.66, 0.26, or 0.44, respectively) is directly proportional to the fluorescence quantum yield observed for folate in the absence of FADH2, as expected for Forster-type energy transfer. Although less efficient, the unnatural [6S]-isomer is catalytically functional, a feature not previously observed with other folate-dependent enzymes. Fluorescence quantum yield studies at 77 K with free ([Phi]=0.67) and enzyme-bound ([Phi]=1.0) folate suggest that differences in solvent exposure may contribute to the fluorescence efficiency differences observed with the enzyme-bound folate isomers at 5 [degrees] C. Expression of yeast photolyase from the existing tac expression system, using the pCB1241 plasmid, produced only modest yields of isolable enzyme (0.13 mg enzyme per gram of cells) due to proteolysis and the presence of insoluble aggregates. An improved expression system for yeast photolyase has been constructed utilizing the highly specific T7 promoter and an expression strain lacking the major E. coli proteases. Using the new plasmid, pRL100, larger quantities of recombinant enzyme have been isolated (2.1 mg/g of cells), free from proteolytic degradation, in a yield 15-fold greater than the earlier expression system. The availability of substantial amounts of pure yeast photolyase has permitted preliminary crystallographic studies.
Brand Anthropomorphism
Authors:   , Reavey Brooke M. , Andras Trina Larsen
Published: July 2024

Brand anthropomorphism is known to affect consumers' attitudes towards products. However, to date, research has treated anthropomorphized brand stimuli as unidimensional in both its design and effects. Here, we investigate two levels of brand anthropomorphism (i.e., implicit versus explicit) that generate different impacts on brand performance. Explicit brand anthropomorphism is defined as imbuing a nonhuman entity with observable and overt human characteristics, whereas implicit brand anthropomorphism is defined as imbuing a nonhuman entity with indirect and subtle human characteristics. Accordingly, we find that these two levels of brand anthropomorphisms interact with the degree of cognitive resources used and the accessibility of persuasion knowledge. In other words, we find that implicit brand anthropomorphism is liked more by consumers because it is considered more artfully deviant but that it also consumes more cognitive resources and does not work well in highly persuasive advertisements. In contrast, explicit brand anthropomorphism does not require the use of as many cognitive resources and is best used in highly persuasive advertisements.
Axonal growth, retraction, and growth-cone navigation are regulated by the balance of molecular motor forces within the axon
Authors:   , Myers Kenneth A. , Baas Peter W
Published: July 2024

During axonal growth, retraction, and growth-cone navigation, the neuronal microtubule array is subjected to molecular motor-based forces that are tighly coordinated with the polarized morphological adaptations of the actin cytomatrix. Within the axon, microtubule-actin interactions drive the advance and retreat of the microtubule array; while within the growth-cone, these same interactions determine the directionality of axonal elongation in response to extracellular signaling cues. These motor-based organizational changes are dependent upon the particular properties of the motor protein, as well as the orientation of the microtubule array. Despite the well documented importance for microtubule-actin interactions, to date there is little evidence regarding the influences of molecular motor forces generated between neuronal microtubules and the actin cytomatrix. My dissertation investigates the balance of motor forces during axonal growth, retraction, and growth-cone navigation. There are three specific aims. Aim 1: Determine the influence of cytoplasmic dynein forces on the transport and organization of axonal microtubules during growth. Aim 2: Characterize the influences of myosin-11 and dynein motor forces on microtubule-actin organization during axonal retraction and growth-cone navigation. Aim 3: Identity how the homotetrameric kinesin-5 motor influences axonal microtubule transport and its relationship to axonal outgrowth and retraction. Methodology for Aim 1 utilized siRNA-based depletion of cytoplasmic dynein, as well as pharmacologic depletion of filamentous actin. These studies revealed that both actin filaments and the dynein motor effect the anterograde transport of short microtubules without influencing retrograde transport. In addition, dynein depletion resulted in a reduction in axonal length and increses in the distance of axonal retraction. Aim 2 combined dynein depletion with pharmacologic inhibition of the myosin-II motor. These studies revealed that dynein motor forces are crucial to proper microtubule invasion of actin-rich growth cone filopodia during growth cone turning, while myosin-II forces act to antagonize dynein's effects on microtubule advance. Aim 3 utilized kinesin-5 siRNA in order to study microtubule transport and neuronal morphology. These investigations revealed that the kinesin-5 motor regulates the bi-directional transport of axonal microtubules and also functions to regulate stepwise axonal growth and retraction.
A methodological study of a nonlinear stochastic model of the AIDS epidemic in Philadelphia
Authors:   , Sleeman Candace Kim
Published: July 2024

A nonlinear stochastic model with heterogeneous risk behavior and recruitment is fitted to Philadelphia public health data adjusted for delays in reporting. Nonlinear difference equations embedded in a stochastic population process are used in computer intensive searches through the parameter space of time homogeneous factor and level combinations to fit projections for cumulative new AIDS cases to data for whites and blacks. Time inhomogeneous factors are applied in efforts to improve the fits and compute confidence bounds for the projections by Monte Carlo simulation, which measures central tendency for the random functions of the process. The model partitions the population into the risk categories of homosexual, bisexual, or heterosexual male, and prostitute or nonprostitute female. Each is further partitioned by intravenous or non-intravenous drug use, a low or high level of needle sharing and sexual contact, and state of HIV disease. The epidemics are seeded by high risk homosexual and bisexual males with recruitment of susceptibles based on census and behavioral data. The Philadelphia public health data covers 1981 to 1992 with a sharp upturn in AIDS cases in 1987 corresponding to a change in the definition of AIDS. The various combinations of factors providing good fits to the data for individual risk categories suggest that several different epidemics exist. Further, for white and black male homosexual/bisexual non-intravenous drug users, the largest data risk categories, the better fitting confidence bounds are achieved with the probabilities of infection per sexual contact decreasing over time. This could suggest an increased awareness of HIV transmission and the use of condoms to prevent infection. For white male homosexual/bisexual non-intravenous drug users, the fit suggests that recruits may be decreasing over time as well.
Deposition and characterization of diamond-like carbon, SiO₂, and their nanocomposite thin films by ion-assisted PECVD
Authors:   , Lee Junghwan , Lee Young Hee
Published: July 2024

There has been much interest in depositing high quality thin films of diamond-like carbon (DLC) and silicon dioxide (SiO₂) at low temperatures for applications in wear-resistant coatings and microelectronics. In this work, the effects of reactor parameters on the structure, and properties of DLC, SiO₂, and their nanocomposite films are investigated. The films are deposited in a 13.56 MHz, rf power driven asymmetric reactor. In-situ impedance analysis is used to estimate the ion energy and flux at the substrate, while an on-line mass spectrometer (MS) and optical emission spectrometer (OES) are used to analyze plasma chemistry. The film structure is evaluated by a Raman spectrometer, a FTIR a Rutherford backscattering spectrometer (RBS), and an ellipsometer. In depositing DLC films, styrene (C₈H₈) is used as the source gas, while H₂ or Ar is used as the carrier gas. The impedance analysis shows that the ion energy flux (IEF) is linearly proportional to power/pressure ratio. The FTIR spectra of the deposited film indicate that CH₃* is likely to be the precursor for the DLC. The film structure reveals that the sp² carbon fraction, density, and refractive index of the film increase with increasing IEF, while the film's hydrogen content decreases. It appears that the IEF has a significant effect on the thermal stability and the optical band gap. For depositing SiO₂ films, tetraethylorthosilane (TEOS) is used as the source gas, while Ar and O₂ are used as carrier gases. The MS and OES results indicate that the decomposition of TEOS is enhanced as the power input is increased and that the role of O₂ is to oxidize the hydrocarbon molecules. It appears that high quality film close to thermal oxide can be obtained at relatively high IEF. It appears that the structure and properties of nanocomposite films are affected significantly by the gas flow rate ratio of the source gases. As the fraction of TEOS flow rate is increased, the refractive index, intrinsic stress, and graphitization decrease, while the transparency increases. The nanocomposite films show excellent adhesion on inorganic substrate, and thus relatively thick films (up to 5 [mu]m) can be deposited without delamination. Also, they exhibit comparable hardness to DLC films.
The cognitive correlates of autonomic functioning in patients with schizophrenia
Authors:   , Monaco Catherine Ann , Chute Douglas L.
Published: July 2024

The specific goal of this dissertation is to determine the relationship between cognitive functioning and autonomic functioning in chronic schizophrenia patients. The present study represents a first attempt to empirically test the relationship between a full set of neuropsychological tests and a complement of both tonic and phasic measures of autonomic functioning. A sample of forty-three patients with schizophrenia was examined to determine if sympathetic arousal has a general, common effect across all cognitive domains, or selective effects on particular domains of function. Cognitive functioning was assessed through composite measures of functioning in 11 neuropsychological domains, and with selected individual tests that capture the distinction between automatic and effortful processing. Autonomic functioning was assessed through measures of tonic and phasic skin conductance levels. It was hypothesized, based on several findings and theoretical positions, that low autonomic arousal would have a non-selective negative effect across all cognitive domains. In general, the hypotheses of this study were not supported. Results indicated several trends showing that cognitive performance is better when autonomic arousal is lower. The results of a Discriminant Function Analysis yielded no significant differences between patients identified as consistently phasically high or low and performance on cognitive tests. Alternate factors such as medication regimen, smoking status, symptomatology, duration of illness, education and gender, also did not appear to affect either cognitive performance or autonomic arousal levels. Results are discussed in light of several models of information processing, methodological considerations, and major models of arousal and performance (e.g., the Yerkes-Dodson law). It is emphasized that the reduced levels of autonomic arousal under cognitive demand as observed in the present study, may reflect methodological issues that need to be addressed in future research of this nature.