bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship between the leadership behavior of library supervisors and the performance of their professional subordinates
Authors:   , McCawley Christina Wolcott
Published: July 2024

The purpose of this study was to investigate the relationship between the leadership behavior of library supervisors and the performance of their professional subordinates. The research was based on Robert J. House's Path-Goal Theory of Leadership. The research hypothesized a triple interaction among Initiating Structure, Task Structure and Need-for-independence on subordinate Performance. Specifically, the hypotheses predicted that under high Task Structure, the Initiating Structure-Performance relationship would be more positive for subordinates with low Need-for-independence than for subordinates with high Need-for-independence. Under low Task Structure, the Initiating Structure-Performance relationship would be strongly positive regardless of the subordinate's Need-for-independence. It was further hypothesized that the reason for this triple interaction was a low relationship between Initiating Structure and Expectancy-II and between Initiating Structure and Intrinsic Activity Value for high Need-for-independence people under high Task Structure. Questionnaires were sent to 865 professional librarians in academic libraries in Pennsylvania and states contiguous to Pennsylvania. Performance evaluation questionnaires were also sent to their supervisors. The questionnaire to subordinates included the Initiating Structure and Consideration portions of the Leader Behavior Description Questionnaire-Form XII, and several other scales, including some which were self-constructed based on an analysis of the jobs of Reference Librarians and Catalogers. Data analysis was by moderated regression analysis and subgroup analysis. Results showed (1) that Need-for-independence did not function as a moderating variable between Initiating Structure and Performance. (2) The effect of Task Structure as a moderating variable was the opposite of the effect predicted by traditional Path-Goal Theory. The Initiating Structure-Performance relationship was higher under high Task Structure than under low Task Structure. (3) Subgroup analysis suggested the possibility of a curvilinear moderator effect in some groups. (4) Intrinsic Activity Value was the only intervening variable to mediate the relationship between Initiating Structure and Performance; it did not mediate the Initiating Structure-Task Structure interaction. It was conjectured that the high educational level of the subjects may have been responsible for the results being opposite to Path-Goal Theory. Also, it may be that librarians as a group have low Need-for-independence.
The focus-execute component of attention
Authors:   , Lesniak-Karpiak Katarzyna , Barakat Lamia
Published: July 2024

Children with Turner Syndrome (TS) (n = 61) and healthy children (n = 60), whose ages ranged from 6 to 17, were compared on the focus-execute attention measures. The focus-execute component of attention is the ability to identify salient features, and perform rapid responses under conditions of distractions (Lyon, 1994). Findings suggested that children with TS performed significantly less well on the following measures of the focus-execute component of attention: Stroop Color and Word Test (Golden, 1978) and the Trail Making Test B (Reitan & Wolfson, 1985). No differences between the groups were found on the Symbol Digit Modalities Test (Smith, 1982) and Concentration Endurance Test (Brickenkamp, 1981). The pattern of performance on the focus-execute attention measures of young and old children with TS did not differ from that of young and old healthy comparison children. In general, children with TS performed within the normative range on low but not high task demands. Karyotype of children with TS was not related to the level of performance on the focus-execute attention measures. In examining unique contributions of several potentially confounding variables (e.g., visual-spatial, motor, impulse control, and working memory) to the focus-execute attention measures, visual-spatial skills and working memory were found to account for variance in the performance on the Stroop Color condition only, indicating that the focus-execute measures used in the study were relatively not confounded. Results are discussed in the context of an integrated model of attention proposed by the present author to explain the nature of the focus-execute component of attention in children with TS. The need for establishing ecological validity of the focus-execute attention measures to assist in planning psychoeducational interventions for children with TS is suggested.
Synthesis, processing and characterization of nanostructured metal oxides as electrode materials
Authors:   , Liu Xinghua , Shih Wei-Heng
Published: July 2024

The performance of electrodes is of major importance to battery and electrolysis systems. The main functions of electrodes are to provide reaction sites for the electrochemical reactions to take place and to supply pathways for electrical conduction and mass transportation. Therefore, electrode materials must be very stable and have sufficient electrical conductivity, electrocatalytic activity and surface area at operating conditions. In the oxidative anode (electrolysis) or cathode (fuel cells) environment, only certain metal oxides could meet these requirements. Nanostructured materials, such as mesostructured and nanosized particles can provide very high surface area. Mesostructured nickel oxide was formed in NiSO₄ and cetyltrimethylammonium bromide (CTAB) aqueous solution. Addition of sodium silicate in the solution stabilized the mesostructure. Mesostructured nickel silicate with specific surface area as high as 530 m²/g was achieved. For improving the conductivity of electrodes, nanosized powders of Electrically conductive perovskite-type oxides such as LaNiO₃ and La_[1-x]Sr_xM_nNi_yO₃ were synthesized by a sol-gel co-precipitation method. By changing the amount x of A-site strontium substitution and y of nickel nonstoichiometry addition in La_[1-x]Sr_xMnNi_yO₃, the electrical conductivity of La_[1-x]Sr_xMnNi_yO₃ at elevated temperatures in air could be improved. Electrochemical properties of mesostructured NiO and perovskite-type oxides were investigated by cyclic voltammetry, steady-state polarization and AC-impedance techniques in strong basic solution at room temperature or in air at 800 °C. The hybrid electrode of a mixture of mesostructured nickel silicate with nanosized powders of LaNiO₃ shows remarkable specific capacitance of ~83 F/g. Cathode of solid oxide fuel cell (SOFC) made of La_[1-x]Sr_xMnNi_yO₃ has lower (~ factor of 2) interfacial resistance and overpotential than that of the most popular cathode material La_[1-x]Sr_xMnO₃. It indicates that La_[1-x]Sr_xMnNi_yO₃ is a promising cathode material for SOFC application.
End-user computing
Authors:   , Wildemuth Barbara M. , Griffith Belver C.
Published: July 2024

One feature of the current information age is the use of computing and other information technologies in work settings. In particular, a new type of technology, called an intellectual technology, has emerged, requiring that the user of adopter take an active role in developing the functionality of the technology. The goals of the current research were to develop an empirically-grounded model of the adoption process for intellectual technologies, and to identify the variables which have the strongest effects on that process. To accomplish these goals, the adoption of end-user computing applications was studied in five intact departments from three different corporations. Data were collected through a series of five in-depth interviews with each study participant, direct observation of the department's activities, and examination of already-existing documents related to the department's computer use. Based on the computing applications in use in these five departments, a five-stage model of the adoption process was developed. The five stages are: Resource Acquisition, in which staff, hardware, software and training are acquired; Application Development, in which specific procedures for using a specific hardware/software combination are developed to perform a specific function; Adoption/Renewal, in which the application is adopted by a person other than the developer and/or additional resources are acquired; Routinization/Enhancement, in which the application becomes part of the department's standard operating procedure and/or is enhanced in some way; and External Adoption, in which the application is adopted by someone outside the developer's department. The results of this study also indicate that the manager's approach to computing, the availability of slack time, the accessibility of hardware/software, and computer expertise within the end-use department have strong effects on the adoption of end-user computing applications. In addition to the implications that these findings have for managers in end-user departments, this study has three implications for researchers: it has clarified the definition of intellectual technologies, proposed a new model of the adoption process that is relevant to intellectual technologies, and developed a method for coding events occurring in an ongoing process.
Enabling technologies for robotically-assisted suturesless coronary anastomosis
Authors:   , Kennedy Christopher William , Desai Jaydev P.
Published: July 2024

Over the past thirty years of technical and surgical evolution, the approach to coronary artery bypass graft (CABG) surgery has remained principally unaltered. The need for cardiopulmonary bypass (CPB) to provide a still and flaccid field carries costs and risks such as systemic inflammatory response, stroke and neurocognitive defects, and cardiac complications such as perioperative myocardial infarction. To eliminate the need for CPB during CABG procedures, this dissertation discusses the development of a robotic system for sutureless coronary anastomosis during an off-pump CABG (OPCABG) procedure. The goal of this work is to present a stationary operative site to the surgeon performing the procedure, while providing both visual and force feedback. Towards achieving that goal, this dissertation presents: (1) a method for force-feedback based on information obtained from the vision system, (2) a model of the Mitsubishi PA-10 robot arm that provides minimal interaction forces during the surgical procedure, and (3) a system for bilateral teleoperation that provides motion-cancellation relative to a moving surface. The experimental results presented in this work verify that vision based techniques combined with the material properties of the membrane can provide a reasonably good estimate of the interaction forces without using a force sensor. Our results further demonstrate that our model of the harmonic drive systems in the Mitsubishi PA-10 robot arm provides reasonable trajectory tracking performance with low feedback gains. Finally, our results lead us to the qualitative conclusion that force-feedback minimizes contact forces in motion-canceling teleoperation due to: (a) minimization of the collision forces with the target surface, and (b) minimization of forces due to accidental contact, by taking advantage of the naturally low impedance of the human hand during fine manipulation tasks.
Structure and mechanical properties of 3-D braided composites
Authors:   , Mohajerjasbi Soheil , Wang Albert S. D.
Published: July 2024

Textile preforming is one of the manufacturing processes that offers the potential to make composite structures cost-effective compared to aluminum structures. The thermoelastic properties of the composites made from these textile preforms depend on the fiber architecture (three-dimensional yarn structure of the preform), which in turn depends on the preform processing parameters. In this thesis, the structure of the preform in the 4-step (1 x 1) 3-D braiding process is investigated and the fiber architecture of the braided composite is established based on the movement of the fiber carriers on the machine bed. It is demonstrated that the fiber architecture in the interior, the boundaries, and the corners of the braided composite are different. It is shown that the yarns inside the braided composite do not change direction to create interlocking points. The yarns only change direction in the boundaries and the corners. Five parameters are needed to define the geometry of the preform and the composite. The relationship between the geometric parameters, which may be measured from the surface of the specimen, and the interior fiber architecture of the specimen is demonstrated. A graphical notation, called "compact form", is introduced for depicting the fiber architecture of the preform. This notation facilitates tracing the trajectory of any yarn in the composite. A finite element method is proposed for modeling the deformation behavior of the braided composite. In this method the matrix and the fiber architecture identified for the preform are modeled separately. The fiber and the matrix are distinct elements with no smearing as is customary in lamination theory. The model of the braided composite is obtained by superposition of these two models. The variation of the thermoelastic constants of the braided composite as a function of braiding angle and fiber volume fraction is demonstrated. The approach proposed in this thesis for establishing the fiber architecture of the preform is general enough to be applicable to other textile composite processes. The modeling technique of this thesis may be applied to calculate the thermoelastic properties of braided composite parts including axial yarns. It can also be used to study the response of braided parts of complex shapes under complex boundary conditions and loading.
Simulation Learning Modalities among Nurse Practitioner Students using Herpes as a Case Exemplar
Authors:   , O'Meara Amy M. , Bloch Joan R
Published: July 2024

INTRODUCTION: Clinical simulation education is increasingly popular in health care education. Methods such as use of standardized patients to teach and practice communication skills, however, are either minimally studied or not studied at all. Communicating with patients about asymptomatic herpes screening is one such communication scenario. Herpes is a complex and highly stigmatized infection. In recent years, tests to screen for exposure to herpes have become readily available. With this availability has come the need for nurse practitioners well versed in the virus and the implications of testing who are able to communicate this information to patients. The objective of this study was to compare practicing with standardized patients to practicing with student peers for nurse practitioner students learning to provide counseling to patients desiring screening for asymptomatic herpes. METHODS: Nurse practitioner students were recruited and randomized into two groups. One group participated in a herpes screening patient education scenario with a standardized patient. The second group practiced an identical scenario with a randomly selected peer. Students' communication was assessed, as was student perception of the simulation and its effectiveness. RESULTS: An experimental design was used. Twenty two nurse practitioner students were randomized into two groups. When comparing the two groups, all results were statistically identical. The null hypothesis, that both groups would perform identically, was rejected only for the following statement: "I developed a better understanding of the pathophysiology of the conditions in the scenario". For this statement, the peer role playing group scored two standard deviations higher than did the standardized patient group (P = 0.00092 for the t-test). Though the sample size was small, sophisticated statistical simulations were run that suggested results would be equivalent given a more robust sample size. CONCLUSIONS: There is no evidence from this work that performing with standardized patients is superior to peer role playing for the scenario provided; in fact, there is some suggestion that peer role playing may be the superior pedagogical methodology in this instance. Because of the resources required for clinical simulation education, these methods deserve the same scrutiny and basis on evidence as our clinical practice should
O-GlcNAcylation Regulates Pancreatic Cancer Cell Survival and NF-[kappa]B Signaling
Authors:   , Ma Zhiyuan , Vosseller Keith
Published: July 2024

Cancer cell metabolic reprogramming includes a shift in energy production from oxidative phosphorylation to less efficient glycolysis even in the presence of oxygen (Warburg effect) and use of glutamine for increased biosynthetic needs. This necessitates greatly increased glucose and glutamine uptake, both of which enter the hexosamine biosynthetic pathway (HBP). The HBP end product UDP-N-acetylglucosamine (UDP-GlcNAc) is used in enzymatic post-translational modification of many cytosolic and nuclear proteins by O-linked [beta]-N-acetylglucosamine (O-GlcNAc). Increased HBP flux in diabetes has been linked to increased levels of O-GlcNAcylation. This led us to hypothesize that cancer metabolic reprogramming may drive increased levels of O-GlcNAcylation. In this study, we observed increased HBP flux and hyper-O-GlcNAcylation in human pancreatic ductal adenocarcinoma (PDAC). PDAC hyper-O-GlcNAcylation was associated with elevation of OGT and reduction of the enzyme that removes O-GlcNAc (OGA). Reducing hyper-O-GlcNAcylation had no effect on non-transformed pancreatic epithelial cell growth, but inhibited PDAC cell proliferation, anchorage-independent growth, orthotopic tumor growth, and triggered apoptosis. PDAC is supported by oncogenic NF-[kappa]B transcriptional activity. The NF-[kappa]B p65 subunit and upstream kinases IKK[alpha]/IKK[beta] were O-GlcNAcylated in PDAC. Reducing hyper-O-GlcNAcylation decreased PDAC cell p65 activating phosphorylation (S536), nuclear translocation, NF-[kappa]B transcriptional activity, and target gene expression. Conversely, mimicking PDAC hyper-O-GlcNAcylation through pharmacological inhibition of OGA suppressed suspension culture-induced apoptosis and increased IKK[alpha] and p65 O-GlcNAcylation, accompanied by activation of NF-[kappa]B signaling. Furthermore, we mapped O-GlcNAcylation of p65 at T305, S319, 5337, T352, and S374. O-GlcNAcylation of p65 at T305 increased CBP/p300-dependent activating acetylation of p65 at K310, contributing to NF-[kappa]B transcriptional activation. In addition, elevation of O-GlcNAcylation by overexpression of OGT increased the expression of p300, IKK[alpha] and IKK[beta] and promoted IKK-mediated activating phosphorylation of p65 at S536, contributing to NF-[kappa]B activation. Our data indicate that pancreatic cancer exhibits hyper-O-GlcNAcylation and that hyper-O-GlcNAcylation is anti-apoptotic and through interplay with phosphorylation and acetylation contributes to NF-[kappa]B oncogenic activation in PDAC.
Impact of Defendant Race and Gender on Mock Jurors' Sentencing of Psychopathic Defendants
Authors:   , Strohmaier Heidi , Heilbrun Kirk
Published: July 2024

Although recent studies have examined the prejudicial effects of labeling a defendant as psychopathic, no research has explored whether the race and gender of a psychopathic defendant impact the manner in which the defendant is evaluated by mock jurors. The purpose of this study was to investigate whether these particular demographic variables interact to influence mock jurors' sentencing recommendations and perceptions of psychopathic defendants. A total of 178 participants were recruited from a large northeastern university and separated into four conditions. Using vignettes, the race (African American or Caucasian) and gender (male or female) of the psychopathic defendant were manipulated. Participants' responses to an online questionnaire were analyzed to examine the hypotheses that the race and gender of a psychopathic defendant interact to affect mock jurors' sentencing recommendations and perceptions of the defendant. Results revealed that participants generally perceived and treated Caucasian male psychopathic defendants most negatively, whereas they tended to perceive and treat Caucasian female psychopathic defendants most favorably. Possible influences of cultural stereotypes and popular culture's depiction of the prototypical Caucasian male psychopath are discussed.
Determinants and outcomes of social support provided by women and men in dual-earner relationships
Authors:   , Purohit Yasmin Surendra , Parasuraman Saroj
Published: July 2024

Research on social support has highlighted the importance of supportive social relationships in sustaining the health and well being of individuals. Support has been examined extensively as an independent variable and from the support receiver's point of view, but rarely as a dependent variable from the support provider's point of view. In addition, researchers have not examined the outcomes of providing support. This study addressed these research oversights and examined the determinants and outcomes of support provision from the support provider's point of view. Supportive relationships have been hypothesized to be particularly important in the case of dual-earner couples who experience severe difficulties in balancing the conflicting demands of two careers in conjunction with maintaining family relationships. In the context of dual-earner couples, social support represents an important interpersonal coping resource. Thus, the determinants and consequences of support provision need to be examined with reference to the needs, abilities, resources, and motivation of the two parties involved in the support exchange. The present study examined the determinants and outcomes of support provision in the context of dual-eamer couples. More specifically, the study examined the support providers' work and family role characteristics, their partners' work and family role characteristics, and the couples' relational characteristics as predictors of emotional and tangible support provision. The model examined in this study predicted both direct and moderated relationships between the above-mentioned variables, support provision and the outcomes of support provision. Data were collected from 104 couples involved in dual-earner relationships where each partner was employed for at least 20 hours/week. Data analyses indicated that the couples' relationship characteristics (the quality of the couples' relationship, and their relative incomes) were the strongest predictors of support provision, followed by the partners' characteristics (work and family role demands and involvement). Interestingly enough, the support providers' characteristics (work and family role demands and involvement and normative beliefs) explained the least variance in support provision. The data also indicated that women reported providing more emotional support than men. Finally, the data indicated no support for the relationship between support provision and the outcome variables (quality of life and burnout).
Effect of calcaneal eversion on standing and walking in children
Authors:   , Orlin Margo Noyovitz , Palisano Robert J
Published: July 2024

The objectives of this study were to examine the immediate effect of excessive calcaneal eversion on the gait parameters of lower extremity peak joint kinematics, temporal spatial characteristics, biomechanical performance and balance skills during standing and walking. A convenience sample of 50 children, ages 6 years to 10 years with typical development, were tested with a counterbalanced repeated measures design in three conditions: no wedges, 5° wedges and 10° wedges. These wedges were affixed to the subject's bare feet to evert the rearfoot resulting in pronation during walking. Results indicated that peak joint kinematics and temporal spatial gait characteristics did not differ across conditions. Biomechanical performance, as measured by vertical sacral displacement during walking was diminished in the 10° compared to the no wedge conditions (p = .001) but not in the 5° compared to the no wedge conditions or in the 10° compared to the 5° conditions. Balance skills were significantly decreased in the 5° compared to the no wedge condition (p = .002) and in the 10° compared to the no wedge conditions (p < .001), but not in the 5° compared to the 10° conditions. The results indicate that the subjects adapted to the wedges and produced their preferred joint kinematics and temporal spatial characteristics when walking. Subjects were unable to adapt as well for biomechanical performance. Balance skills, more novel and challenging than walking for these children, were the most affected by the wedges. These findings should be applied cautiously to children with neuromuscular and musculoskeletal impairments who may not have the adaptation abilities of children with typical development. Excessive calcaneal eversion in these children may create an additional problem for their joint kinematics and temporal spatial characteristics when walking. However, excessive calcaneal eversion is more likely to impact biomechanical performance during walking and balance skills in children both with and without movement disorders. Therefore, intervention to address excessive calcaneal eversion may be indicated to enhance biomechanical performance during walking and standing and walking balance skills.
Reticulocyte-associated protein export machinery and cytoadherence in blood stage malaria parasites
Authors:   , Meibalan Elamaran , Burns James M.
Published: July 2024

Malaria parasites replicating inside red blood cells export several proteins into the erythrocyte cytosol that modify the host cell to facilitate parasite growth and sequestration. Protein export pathways in Plasmodium falciparum utilize parasite-derived structures in the host cytosol including Maurer's clefts, small vesicles and a tubulovesicular membrane network. Studies on exported proteins, trafficking pathways and cytoadherence in reticulocyte-restricted parasites such as P. vivax are limited. Using the P. yoelii 17X rodent model, we performed a proteomic analysis of infected reticulocyte membrane fraction and identified Plasmodium proteins potentially involved in protein trafficking and cytoadherence including PyExp2 (PY05892), pyst-a (PY04481, PY07631), Py14-3-3 (PY01841), PyEnolase (PY06644), hypothetical protein (PY07648) and a putative adhesin (PY00631). Our initial studies were focused on P. yoelii Exported protein-2 (PyExp2). Immunofluorescence studies showed that PyExp2 was localized to the parasitophorous vacuolar membrane (PVM) but also exported into the host cytoplasm on membrane-bound vesicles budding from the PVM. This is in contrast to P. falciparum where PfExp2 was identified as part of the PTEX translocon exclusively localized to the PVM. Co-localization studies showed that two exported proteins, PY04481 (pyst-a) and PY06203 (PypAg-1), were carried within the PyExp2 positive vesicles indicative of vesicle-mediated transport. PyExp2 positive vesicles were primarily observed in CD71+ reticulocytes but not in mature RBCs infected with P. yoelii, P. berghei or P. falciparum. In transgenic P. yoelii 17X parasites, the association of hemagglutinin-tagged PyExp2 with the PVM and cytosolic vesicles was retained but the pyexp2 gene was refractory to deletion. Our data indicate that in addition to its role as a component of PTEX, Exp2 delineates a distinct vesicular protein trafficking machinery in Plasmodium infected reticulocytes. Preliminary studies showed that the endothelial receptor CD36 bound strongly to 30-32 kDa protein(s) in the P. yoelii 17X infected reticulocyte membrane fraction. Of the Plasmodium proteins identified from the membrane fraction, PY00631, a highly charged conserved protein, bound to CD36. Transgenic P. yoelii 17X parasites expressing a 6xHis-tagged PY00631 was generated to purify the native protein. PY00631 was localized to the host reticulocyte membrane during the schizont stages, strongly supporting a role in the cytoadherence of mature blood stages.
Impact of a downstream C/EBP site on HIV-1 gene expression and pathogenesis
Authors:   , Liu Yujie , Wigdahl Brian
Published: July 2024

Previous studies have shown that two CCAAT enhancer binding protein (C/EBP) sites, upstream of the transcriptional start site, are necessary for subtype B human immunodeficiency virus type 1 (HIV-1) gene expression in cells of the monocytemacrophage lineage. However, no studies have been reported concerning the C/EBP sites within the non-subtype B HIV-1 LTRs or downstream of the transcriptional start site within the subtype B LTR. Electrophoretic mobility shift (EMS) analyses demonstrated that one of three putative downstream C/EBP binding sites (downstream element three, DS3) within the subtype B LTR was able to form a DNA-protein complex containing C/EBP[beta]. By utilizing the DS3-9C variant, which exhibits low DNA binding affinity for C/EBP[beta], it has been shown that the DS3 binding site is important for HIV-1 basal transcription. The DS3-9C-containing LTR exhibits a lower basal transcription level and is able to be transactivated by C/EBP[beta]-2 to a lower extent compared to the parental HIV-1 subtype B LTR. However, upon activation with Tat alone or with C/EBP[beta]-2 together, the DS3-9C-containing LTRs exhibit a similar or even greater transcriptional activation than that of the parental LTR. HIV-1 molecular clone viruses containing the DS3-9C C/EBP binding site variant have revealed a decreased replication capacity and a delayed rate of replication. These results suggest that the DS3-9C configuration might be related to virual persistence and reactivation in cells of the monocyte-macrophage lineage. Furthermore, one C/EBP binding site has been identified within the subtype C LTR. Subtype B and C LTRs are able to be activated by C/EBP[beta]-2 to similar levels in the monocytic cell line, U-937. The interaction observed between C/EBP[beta]-2 and Tat with the subtype B and C LTRs suggest the functionally important transactivation ability of C/EBP[beta] among different subtypes that, under certain circumstances, may be cell type dependent.
Highly interactive multimedia in chemical education
Authors:   , Oliver-Hoyo Maria T. , Hutchins Robert O.
Published: July 2024

This dissertation explores the use of multimedia as a tool to introduce history into the chemistry curriculum. Steele's book, "Fourteen Weeks in Chemistry", written in the 1860's is the framework for this highly interactive multimedia project. Five features were developed that provided opportunities for interaction through connections of the past with the present, video clips, timelines, quizzes and interactive questions. Out of this project grew the development of interactive modules that could accompany any chemistry course. The exchange of information between computer and user is based on text and numerical recognition operations. Extensive surveying of student responses to questions and problems led to lesson scripts. Programming in Lingo, Director's authoring language, transformed lesson scripts into interactive software. Students' evaluations showed a strong preference for programs in which user inputs received a specific response. Stronger authoring systems would make the creation and editability of materials easier because of improved text recognition capabilities.
The use of small scale modeling to study the behavior of simply-supported reinforced concrete slabs with openings under uniform loading
Authors:   , Sagur Salah Mohammed , Harris Harry George
Published: July 2024

The small scale modeling techniques are implemented to carry out an extensive experimental study on the complex behavior of reinforced concrete slabs, with particular emphasis on slabs with openings. A total of thirty small scale model slabs were constructed (at one tenth scale) and tested for this investigation. Eight of the slabs tested were solid slabs which were studied for variation in the method of reinforcement (uniform isotropic reinforcement compared to strip method reinforcement), and for variation in the amount of top corner reinforcement. The remaining 22 slabs were slabs with one or two openings at various locations and of various sizes. The slabs were tested using uniformly distributed monotonic loading to failure. The test results were correlated and compared to analytical solutions, and to each other. Overall, the test results on the slabs indicate that the analytical solutions of the slab configurations tested are on the conservative side. It was found from these tests that slabs designed using the strip method behaved satisfactorily and were comparable in behavior to slabs designed using other methods, such as the yield line theory. Three different opening sizes were studied (K = 1/4, 1/2, and 5/8) where K is the ratio of the opening side length to the slab length. It was found that the strength of the slab is not greatly reduced by the presence of the opening, up to a value of K = 1/2, as long as the steel in the area disturbed by the opening is redistributed around the opening edges. In the slabs which had no redistributed steel around the opening, the load carrying capacity was reduced (by up to 30%) especially for uniformly reinforced slabs, as opposed to slabs designed using the strip method. The behavior of slabs with two openings at three different locations is reported and analyzed. All such slabs showed no sign of excessive weakness despite the presence of two openings.
Use of a joystick by people with cerebral palsy in performing screen positioning tasks
Authors:   , Rao Raghavendra Shankar , Seliktar Rahamim
Published: July 2024

Study of the interaction between individuals with disability and the computer has implications in the design of input devices, such as the mouse and keyboard, and in expanding knowledge about movement control. The present work evaluated the performance of non-disabled individuals and those with cerebral palsy in the use of a position-controlled spring-centered position joystick versus a position-controlled isometric joystick. The subjects acquired differently sized targets at different distances by positioning a cursor on the target. Performance with the position joystick was superior when compared with the performance with the isometric joystick. It was found that due to the high stiffness of the isometric joystick, physiological noise was recorded. This led to uncontrolled movement of the cursor on the screen, which added to the distance traversed by the cursor and increased the time needed to reach the target. With the position joystick, the inertial load due to the displacement of the stick and the elastic action of the spring provides damping of the physiological noise. Arm movement generates signals from the joint receptors, providing additional propioceptive feedback in controlling the cursor movement. Movement time was directly proportional to the cursor-target distance, and indirectly proportional to the target size. The phase-plane plot and trajectory of the cursor movement revealed the presence of one primary movement that accounts for the peak velocity, and several submovements. Fitts' paradigm was a good predictor of cursor positioning task for the non-disabled individuals. Subjects chose to move more slowly towards the smaller and closer targets, and they increased speed for larger and more distant targets. Fur individuals with disability, a linear relationship was found between the movement time and accuracy when a force joystick was used.
A study of physical water treatment technology to mitigate the mineral fouling in a heat exchanger
Authors:   , Lee Sung H. , Cho Young I.
Published: July 2024

The objectives of the present study were to investigate the fundamental mechanism of physical water treatments for hard water-bulk precipitation-and specifically to investigate how electromagnetic fields alter the characteristics of scale deposits-particulate fouling-on the surface of a heat exchanger. In an attempt to understand the role of these electromagnetic fields, the present study examined how the performance of the PWT (i.e., permanent magnets or solenoid-coil induction technology) was affected by various parameters such as flow velocity, concentration, geometric arrangement, etc. All experimental studies were conducted in a heat exchanger with circulating cooling-tower water, and the fouling resistance was estimated over a period of time. PWT technology uses a magnetic or electric field to treat hard water physically. It is hypothesized that the external magnetic or electric field precipitates dissolved mineral ions in bulk water to form clusters (i.e., colloidal particles of submicron size). The clusters grow in size as the solubility of the mineral ions drops due to an increased temperature of the water inside the heat transfer equipment. As the clusters compete for dissolved mineral ions with heat transfer surfaces, the fouling at the heat-transfer surfaces is significantly reduced. The present study was conducted to validate this hypothesis. As a direct method, a particle-size analyzer was used to provide supporting data for the bulk precipitation hypothesis. In addition, surface tension measurement and water analysis were used together with one of the PWT technologies to further provide supporting data for the hypothesis. Fouling resistances, which indicated the performance degradation of a heat exchanger, were experimentally measured through heat transfer tests. Real-time microscopy, SEM photographs, and X-ray diffraction were performed to characterize scale deposits. Various key parameters such as flow velocity, water concentration, the arrangement of permanent magnets, and the frequency and strength of the current signal in a solenoid-coil device were examined to determine the optimum conditions for maximum efficiency of physical water treatment methods.
Factor analytic study of the Rorschach Comprehensive System
Authors:   , Vuz Jacqueline Kay
Published: July 2024

The present study considered a factor analysis of the Rorschach Comprehensive System. That is, exploratory factor analysis was conducted to examine the psychometric structure of the Rorschach Comprehensive System using protocols from two diagnostic categories, some of which were used to construct the standardization population for this instrument. The current study utilized protocols from a total of 714 subjects. These subjects can best be described when stratified into two major categories: nonpatient and inpatient depressive adults. The Rorschach Comprehensive System was administered to each patient by experienced psychometricians according to standard procedures set forth in the manual some of which were used to construct the standardization population (Exner, 1990). Permission to use this data was granted by Rorschach Workshops and John Exner, Jr. Thirty variables which met the basic assumptions were submitted to maximum likelihood (ML) factor analysis. The resulting 4 factors were subjected to oblique rotation procedures for further clarification of the underlying dimensions. Maximum likelihood (ML) factor analysis extracted a four factor model which accounted for 37.5% of the total variance in the nonpatient group and 42.6% for the depressives. Findings from these factor analyses are discussed in semblance to previously established factor analytic findings for the Rorschach Comprehensive System. Current findings are also discussed in relation to the underlying content dimensions represented in the Rorschach Comprehensive System for nonpatient and inpatient depressive adults, development of factor analytically derived subscales, and the implications of this factor model for the interpretation strategies with this instrument.
The mitochondrion in the life and death of Plasmodium falciparum
Authors:   , Painter Heather Jill , Vaidya Akhil B.
Published: July 2024

Plasmodium falciparum is the causative protozoan parasite of the most severe form of malaria. This disease is still a major problem throughout many regions of the world and eradication efforts have fallen short. Although effective anti-malaria chemotherapies have been developed, we don't know why these drugs work and whether their effects on the parasite are static or cidal. Mitochondrial electron transport chain is a well established anti-malarial drug target, molecular details underlying the parasite demise have not been elucidated. However, the mitochondrion remains a validated drug target in the malaria parasite. Disruption of the mitochondrial electron transport leads to parasite death. Here we show that the blood-stages of the parasite seem to maintain an active electron transport chain to serve one function; de novo pyrimidine synthesis. By supplying P. falciparum with the Saccharomyces cerevisiae dihydroorotate dehydrogenase (DHOD), which does not require ubiquinone to function, the transgenic parasites become resistant to electron transport inhibitors. Surprisingly, disrupting the flow of electrons does not abolish the mitochondrial membrane potential in P. falciparum and these parasites have established an alternate mode of generating this potential. Subsequently, we explored the effects of atovaquone, alone as well as in combination with its synergistic partner, proguanil, on mitochondrial physiology and the stage specific static or cidal effects of the inhibition of mitochondrial electron transport. Our results suggest that, in P. falciparum, the in vitro effects of atovaquone and atovaquone/proguanil are dependent upon the erythrocytic stage of the parasites exposed to the drugs. We found a large proportion of ring-stage parasites are most resilient to drug treatment and seem to survive for up to 48 hours, with a small fraction remaining viable even after 96 hours of treatment. The survival of the parasites depends on their ability to exist in a 'static' phase; once treatment ceases, the parasites re-enter the erythrocytic development cycle as seen by parasite morphology. To further elucidate the mechanism of resistance development, we have analyzed the response of drug selected parasites to a subsequent drug treatment. These studies begin to provide information on the physiological state of the drug-inhibited parasites when mutations in mitochondrial DNA could arise that lead to drug resistance.
Sphingolipid-dependent endocytosis of multiple sugar transporters
Authors:   , Morgan Jeanelle Marie , Nickels Joseph T
Published: July 2024

Rvs161 is a homologue of the mammalian amphiphysin protein, which has been shown to be involved in endocytosis at synaptic vesicles. Yeast cells lacking Rvs161 have pleiotrophic defects, including endocytosis defects. SUR4 encodes a very long chain fatty acid elongase that is involved in the sphingolipid biosynthetic pathway. Loss of function of SUR4 alters the composition of sphingolipids produced in the yeast cell; in particular, long chain sphingoid bases accumulate in sur4 cells. Loss of function of SUR4 in rvs161 cells re-initiates endocytosis. We are using rvs161 sur4 cells as a model to explore sphingolipid-dependent endocytosis. Studies have identified a long chain base (LCB) dependent endocytic pathway and the cell factors required for its function. rvs161 cells properly localize multiple sugar transporter protein(s) but are unable to endocytose these transporters. Rvs161 is required for endocytosis of these transporters: rvs161 cells accumulate these transporters at the plasma membrane under conditions when these transporters would normally undergo endocytosis and degradation. Deletion of SUR4 re-initiates sugar transporter endocytosis in rvs161 cells. We found that re-initiation of transporter endocytosis requires DOA1, DOA4 and RSP5. Using the endocytosis of the high affinity glucose transporter Hxt2-GFP, we have found a requirement for ceramide activated protein phosphatases (CAPP), the B subunit of which is Cdc55, in long chain base dependent endocytosis.
Essays on corporate fraud
Authors:   , Uzun Hatice , Szewczyk Samuel Hideyo
Published: July 2024

The first essay investigates how the market reacts to announcements of alleged or actual corporate fraud from three different perspectives. First, I analyze the impact on stock prices of such announcements by measuring abnormal returns for different types of fraud announcements at different types of announcement dates. Results show that there are negative and statistically significant market losses around the fraud announcements for firms that are accused of corporate fraud. Second, I examine how financial analysts react to the announcement of corporate fraud for fraud firms by measuring the average and cumulative abnormal forecast revision for the current year, and five-year earnings. Results show that cumulative average forecast revisions for the entire sample are negative and statistically significant for the current year, but not five-year earnings growth. These results suggest that analysts believe that the negative effects that acts of corporate fraud have on the firm's business are short-lived and will not affect future prospects. Third, the effects of corporate fraud on the competitors of the firms accused of fraud are investigated. I examine whether the effects are positive or negative on the rival firms. If rivals are expected to take advantage of the losses of the fraud firms, a positive industry effect is expected. On the other hand, if uncovered fraud reveals the possibility of other firms in the industry engaging in fraud, a negative industry effect is expected. Overall, stock price effects of corporate fraud on competitors differ by types of fraud, types of announcement dates, and firm size. In the second essay, I examine the relationship between effectiveness of internal and external monitoring in prevention of fraud. First, I investigate how characteristics of the board of directors as an internal monitoring affect the occurrence of corporate wrongdoing. Overall results suggest that board composition, board size and composition of committees are important factors to monitor management although results vary across types of corporate fraud. Second, institutional holdings are analyzed to determine its effectiveness in prevention of fraud. Results show that all institution holdings and types of institutional holdings do not affect likelihood of corporate fraud.