bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of physical conditioning in children with chronic arthritis
Authors:   , Klepper Susan E. , Effgen Susan K.
Published: July 2024

Children with chronic arthritis are reported to have lower aerobic and muscular fitness than children without arthritis, but treatment protocols do not include physical conditioning programs, and the effects of conditioning in children with arthritis are unknown. Research during the past 20 years reveals adults with arthritis, who participate in physical conditioning, experience improved aerobic capacity, muscle strength and endurance, function and self-esteem, and decreased articular symptoms. This within subjects, repeated measures study examined the effects of an 8 week physical conditioning program on disease signs and symptoms, physical fitness, and function in children with arthritis. The sample included 25 children with chronic arthritis, ages 8-17 years, from the Alfred I. duPont Institute in Wilmington, DE, St. Christopher's Hospital and the Children's Seashore House in Philadelphia, PA. Measurements, including joint counts (JC), a cumulative articular severity index (ASI) (joint swelling, pain on motion, tenderness, and limitation of motion), 10 cm visual analogue scale (VAS) for worst pain during the previous week, Piers-Harris Self-Concept Scale (PH), Juvenile Arthritis Functional Assessment Report (JAFAR), physiological cost index, and the four components of the Health Related Physical Fitness Test (9 minute run-walk, 1-minute sit-up, sit and reach, and skinfold thickness), were taken at study entry, after an 8 week control (no exercise) period, and after 8 weeks of physical conditioning. The number of days absent from school during the control and exercise periods was recorded. The 60 minute conditioning program, included warm-up, low-impact aerobics, strengthening, cool-down and stretching. Subjects exercised twice a week at the hospital, and once a week at home, using a 60 minute commercial exercise videotape. Repeated measures ANOVA or Friedman ANOVA tests revealed significant differences in the ASI, JC, VAS, run-walk, sit and reach, and Piers-Harris scores. Post-hoc tests showed significant improvement in ASI, JC, run-walk, and sit and reach scores from the pre to post-exercise tests. VAS and Piers-Harris scores improved significantly from baseline to the pre-exercise tests, but the pre to post-exercise difference scores were not significant. No differences were found on the other measures, but there was a positive trend toward improvement in scores on the JAFAR. These results suggest children with arthritis can improve their aerobic endurance and flexibility through physical conditioning without disease exacerbation, and can achieve benefits of decreased articular signs and symptoms. Further study is needed to examine the impact of longer term conditioning programs on functional abilities and self-esteem.
Some attributes of online search intermediaries that relate to search outcome
Authors:   , Hahn Trudi Bellardo
Published: July 2024

The purpose of the study was to investigate some personal attributes of online search intermediaries that were believed to affect the quality of their search results. Sixty-one subjects were selected from the online searching courses in six graduate programs in library and information science. The degree of proficiency of the subjects at the end of their DIALOG training was measured by their performance on two questions that they searched in the ERIC ONTAP database. Their creativity level was measured using two self-report inventories, their intelligence level was approximated from their GRE Quantitative and Verbal scores, and their personality traits in regard to masculinity, femininity, and self-esteem were assessed were measured using the Interpersonal Disposition Inventory. Factor analysis was used to reduce the large number of independent variables to four clusters, called Attributes. Attribute 1 was a dimension reflecting an assertive, self-confident, risk-taking personality type. Attribute 2 was defined in terms of scholastic aptitude and artistic creativity. Attribute 3 reflected a critical and original personality type that prefers to work alone and thinks for himself. Attribute 4 was a dimension reflecting compassion, nurturing, sensitivity and understanding. The four Attributes were related to the dependent variables in a regression analysis to see which, if any, of the Attributes predicted the ERIC ONTAP scores. The result was the average recall was predicted by Attribute 2 and recall for one of the search topics was predicted by Attribute 3. Recall for the other search topic, all precision scores, and all unit cost scores could not be predicted by any of the Attributes. The study findings suggest that the differences in performance among individuals with the same level of experience and type of training can be attributed, to a small degree only, to their general verbal and quantitative aptitude, their artistic creativity, and to their inclination toward critical and analytical creative thinking. The findings also raised serious doubts, however, that high intelligence and other attributes cited by writers in the field are necessary for high performance. The validity of the notion that online search intermediary performance can be predicted by or is dependent upon certain cognitive or personality traits has thus become highly suspect.
Determination of the level of understanding in the use of peripheral nerve stimulators among three groups of anesthesia providers
Authors:   , Wallace Allen F.
Published: July 2024

The use of neuromuscular blocking agents in the operating room is common. A peripheral nerve stimulator (PNS) is often used to monitor neuromuscular function following the administration of neuromuscular blocking agents. This study employed a questionnaire to investigate whether knowledge deficits exist among practitioners in the use of PNS. The study focused on the technical, physiological, and pathophysiological implications of neuromuscular assessment. The study evaluated the degrees of understanding among three groups of anesthesia providers: nurse anesthesia students (NAS), CRNA's, and anesthesiologists. NAS knew significantly more about the technical aspects of PNS than either CRNAs or anesthesiologists and significantly less about pathophysiological aspects than the other two groups. Inservice attendance did not significantly effect knowledge levels. Knowledge of pathophysiological and technical aspects of PNS were significant related to years of experience. Greater experience had a negative association with technical knowledge and a positive association with pathophysiological knowledge.
Structure and properties of polymer nanocomposite coatings applied by the HVOF process
Authors:   , Petrovicova Elena , Knight Richard , Twardowski Thomas
Published: July 2024

A high velocity oxy-fuel (HVOF) combustion spray process was used to produce coatings from nylon 11 powders with average starting particle diameters of 30 and 60 gin. Silica and carbon black were used as nanosized reinforcements, and their nominal content was varied from 0 to 15 vol. %. Optimization of the HVOF processing parameters was based on an assessment of the degree of splatting of polymer particles, and was accomplished by varying the jet temperature (via the hydrogen/oxygen ratio). Gas mixtures with low hydrogen contents minimized polymer particle degradation. Analytical modeling of particle temperature profiles confirmed the effect of the gas velocity and temperature on the particle heating and resulting coating properties. The morphology of the polymer and the microstructure of the coatings depended on the reinforcement surface chemistry and the volume fraction of the reinforcement, as well as the initial nylon 11 particle size. Although all reinforced coatings had higher crystallinities than pure nylon 11 coatings, coatings produced from a smaller starting polymer particle size (30 [mu]m) exhibited improved spatial distribution of the silica in the matrix and lower crystallinity. In addition, coatings produced from the smaller polymer particles had a higher density and lower porosity due to a higher degree of melting and splatting compared to coatings produced from larger particles (60 [mu]m). Nanoreinforced coatings exhibited increased scratch and sliding wear resistance and improved mechanical and barrier properties. Improvements of up to 35% in scratch and 67% in wear resistance were obtained for coatings with nominal 15 vol. % contents of hydrophobic silica or carbon black, relative to nonreinforced coatings. Reinforcement of the polymer matrix resulted in increases of ca. 200% in the storage modulus both below and above the glass transition temperature. The increase in crystallinity seemed to further enhance the reinforcement provided by the nanoparticulates. Results also showed a decrease in the water vapor transmission rate through nanoreinforced coatings by up to 50% compared to pure polymer coatings. The aqueous permeability of coatings produced from 30 [mu]m polymer particles was lower due to the decrease in porosity. Crystallinity seemed to have a strong influence on the mechanical properties, whereas permeability of thermally sprayed coatings was dominated by coating porosity.
Modeling, simulation and prediction of rockwell hardness indentation
Authors:   , Ma Li , Zhou Gongyao
Published: July 2024

Rockwell C hardness (HRC) test, which measures a material's resistance to localized plastic deformation, is a valuable and commonly used mechanical test for evaluating mechanical properties of steels and other high-strength metals because of its simplicity, low cost and non-destructivity. However, the accuracy of HRC measurements is still in question. An international effort is being made to establish a world-wide unified Rockwell hardness scale with metrological traceability. A key factor affecting Rockwell hardness testing and standardization is the Rockwell diamond indenter. The National Institute of Standards and Technology (NIST) proposed a metrological approach using high accuracy standard Rockwell indenters to reduce the HRC measurement uncertainty. The difficulty of manufacturing diamond indenters to the required geometric specifications has resulted in most commercially manufactured indenters, to vary in shape from one to another. This difference in shapes is thought to be a major contributor to Rockwell hardness measurement uncertainty. In this study, HRC hardness tests and influence quantities are investigated. The mechanical models for Rockwell hardness indentation are established and analyzed for both elastic and inelastic materials using self-similarity simplification approaches. It is shown that by using principles of similarity and cumulative superposition, the complicated moving boundary condition problems could be simplified to that of an intermediate stationary one for a flat indenter. A Finite Element Analysis (FEA) model for Rockwell hardness measurement is established and analyzed. The specimen size, element type and mesh selection are studied to obtain high efficiency and accuracy of the FEA model. Different FEA simulation results including the force-depth relation, stress strain distribution and geometrical effects of the Rockwell indenter (tip radius, cone angle and form error) are discussed, analyzed and verified by the experimental results. A new method is developed to input the Rockwell indenter profiles into the FEA model for HRC prediction directly. The prediction results show good agreement with NIST experimental results. In order to obtain the test material properties, a reverse computation method is introduced. In this method, the reverse computations are conducted based on different loading conditions. The method is further verified by NIST experimental results.
Cephalic blood flow velocity and tissue oxygen desaturation during exposure to +G_z acceleration profiles
Authors:   , Johanson David Carl , Dubin Stephen E
Published: July 2024

Incapacitation of aircrew due to Loss of Consciousness following exposure to high acceleration levels (GLOC) has been frequently reported during the past decade. While a few noninvasive measurements of the physiological parameters contributing to the phenomenon have been reported, they have generally been reported singularly. Though not directly measured, a lack of cerebral oxygenation has been indicated in several studies. Of those measurements reported, estimation of peripheral light loss (PLL) and Doppler blood flow velocity are among the most common. Estimated or measured PLL can be considered both a subjective and objective form of measurement of oxygen delivery to a specific tissue; Doppler velocity is an indirect objective measurement of the flow of blood. A more direct objective measure of oxygen delivery is provided by blood oxygen saturation. This study reports changes in measurement of oxygen saturation (SaO2) measured at the bridge of the nose and changes in Doppler blood flow velocity measured at the superficial temporal artery and the associated levels of PLL in 11 subjects exposed to accelerations up to 10 G2. Acceleration onset rates varied from 0.1 to 5 G*sec-1 and offset rates varied from 1.82 to 5.91 G*sec-1. Oxygen saturation values, following G onset, ranged from 99%-61%; doppler velocities, following G offset, demonstrated 7%-267% increases over the pre-stress values. The following observations were made. (1) Rapid Onset Rate (ROR) and Gradual Onset Rate (GOR) onset runs have to be considered separately, (2) Time of lowest SaO2 reading did not appear to have any effect on the duration (time) of run, (3) GOR and ROR exposures generally produce different relative amounts of "desaturation" at Peripheral Light Loss (PLL) or fifteen seconds at peak G (G15), (4) Offset rates didn't appear to contribute significantly to the response to G, (5) Reactive hyperemic response, as measured by the doppler, returns to pre-run value prior to the oximeter returning to pre-run values, and (6) The duration of the reactive hyperemic response provides an indication of the relative amount of tissue oxygen desaturation, (r =.85). The monitoring of blood oxygen saturation may be a potentially good measure of an impending LOC episode; further study is required to confirm this observation.
Closed Loop Control of Wire Loop Profile on Wire Bonders
Authors:   , Milton Basil , Qin Ivy W
Published: July 2024

Wire Bonding involves establishing interconnections between a microchip and other electronic pars during semiconductor device packaging process. The wires are welded using thermosonic or thermo compression bonding. One of the major challenges in wire bonding that affects performance and reliability is the formation of wire bond loop. The wire bond loop shape needs to satisfy all the complex interconnections required by the semiconductor device within industry standards as well as the device dimensions and pad spacing constraints. The wire loop is characterized by its shape, length and height which collectively define a 'Loop Profile'. This paper presents a detailed analysis of the factors that determine the shape of a mechanically stable wire towards establishing closed loop control of the loop profile on the wire bonder. Mechanically stable configuration is determined from the analysis of factors affecting loop shapes via a collection of experiments performed on the wire bonder. The relationship between the parameters used to construct different wires and the actual shape of the wire is used to construct a model that simulates the wire bonder. Furthermore, the paper explores ways to achieve closed loop optimization by using on bonder measurements and development of optimization algorithms. 'Advanced Process Control [APC] ideologies are collaborated into advanced optimization algorithms using MatLab® and on-bonder wire loop measurement features to automate and culminate precise loop profile development incorporating external factors. This effort will help curtail expenditure and save time prodigiously.
Thin film CuInSe₂/Cd(Zn)S heterojunction solar cell
Authors:   , Eron Murat Nezir
Published: July 2024

The results of experimental measurements and characterization of high efficiency, thin film CuInSe₂/Cd(Zn)S solar cells provided by Boeing are reported. These devices are produced by elemental evaporation; they have very high I_[SC] but lower than expected V_[OC] and FF. An automated, multi-purpose experimental station was developed which can carry out capacitance, current, spectral response measurements as a function of voltage, frequency, wavelength, light bias intensity and temperature. The device is modeled as a p-i-n heterojunction where the interface largely determines the device properties and transport. Long time constants of capacitance transients were observed as light or voltage bias was changed. From such transient data it is deduced that a bulk deep level hole trap exists in the selenide which has a density nearly the same as the free carrier density. It was also observed that the photocurrent is strongly bias dependent in violation of the superposition principle. It is shown, by using chopped light data of collection efficiency and the dark I-V, that the "light" diode can be fully explained on the basis of a voltage dependence of the photocurrent. The crossover of light and dark I-V curves is similarly explained. The effects of such a voltage dependent collection factor on all cell parameters are analyzed and explained. Heat treatments were carried out, and device parameters and cell performance were monitored as a function of baking. It is concluded that baking mainly improves the selenide properties rather than improving the interface. A detailed interface charging model is proposed which successfully accounts for A, I_O and the voltage dependence of the photocurrent. It is concluded that higher efficiencies, on the order of 13-14%, are possible if selenide conductivities can be increased, R_S lowered, conduction band discontinuity reduced, back contact improved and higher energy photons are utilized in I_[SC] by an electroluminescent front cover.
Design of H-infinity controller by energy dissipation approach
Authors:   , Yang Paohwa , Chang Bor-Chin
Published: July 2024

In this thesis, a controller design based on the energy dissipation approach is proposed to solve a more general H[infinity] control problem with nonzero direct feedthrough term D11(x) from the exogenous input to the controlled output. Initially, we discuss the relationship between the dissipative system and the H[infinity] control and then formulate the H[infinity] control problem as an energy dissipation problem. Due to the requirement of the closed-loop system to be [gamma]-dissipative, the conditions for the existence of solution to the problem can be derived. With the separation principle proposed by Bail, Helton and Walker, a dissipative controller can be constructed as well. For the nonlinear system, we will derive the necessary conditions for the closed-loop system to be dissipative and present the formulas to constructing a dissipative controller. These necessary conditions involve two Hamilton Jacobi inequalities which are the counterpart of the Riccati inequalities in the linear H[infinity] control. With the proposed dissipative controller, we show that the closed-loop system is [gamma]-dissipative. The solution to the linear case of the problem will also be given. The two Hamilton Jacobi inequalities will reduce to the two Riccati inequalities in the linear case and the coupling condition between the two Hamilton Jacobi solutions corresponds to that the spectral radius of the product of the two Riccati solution is less than the square of the prescribed bound.
Estrogen receptors in Gladiolus primulinus, and Studies on estrogen stimulation of reproductive cells in Sprague-Dawley rats
Authors:   , Janik Joseph R.
Published: July 2024

An endogenous receptor for 17 (beta)-estradiol was characterized from the ovules of Gladiolus primulinus. This protein "translocates" from the cytoplasm to the nucleus upon activation by 17 (beta)-estradiol. The activated receptor has a sedimentation coefficient of 4.7 (+OR-) 0.1, and association constants with total specific binding capacities in the cytoplasm of 8.9 x 10('8) M('-1) and 16.2 x 10('-4) picomoles of estradiol per mg of tissue; and in the nucleus of 9.1 x 10('8) M('-1) and 22.6 x 10('-4) picomoles of estradiol per mg of tissue. Estradiol, estriol and diethyl-stilbestrol bind to this receptor while testosterone and progesterone essentially do not. This receptor was not detected in the anthers. Stimulation by 17 (beta)-estradiol induced a quantitative synthesis of proteins (receptors) which specifically bind progesterone in the uterine and ovarian cells of Sprague-Dawley rats. Both ovarectomized and intact animals had a similiar response. In the estrogen primed uterus of Sprague-Dawley rats, a receptor for epidermal growth factor (EGF) was present on myometrial cells but not on epithelial or stromal cells. The EGF receptor has an association constant of 6.4 x 10('9) M('-1) with a total specific binding capacity of 56 picomoles of EGF per mg of uterus. Preliminary evidence suggest the existence of a similiar EGF receptor on Human adenocarcinoma cells (HEC-59).
Studies applying computers to the analysis of the thermodynamics and molecules spectroscopy of sulfur
Authors:   , Vinansky George
Published: July 2024

This thesis is concerned with the genesis of algorithms and of protocols needed to achieve proper and unambiguous computer analysis of thermodynamic and of molecular spectroscopic data. Scrutiny of thermodynamic literature of pure sulfur revealed that gaseous homogeneous sulfur systems were understood, the heterogeneous systems were not. Of all saturated vapor pressure data only five data sets were suitable for regression analysis. Analysis showed that although Meisen and Bennet's work did not use all suitable data their results were acceptable. The results obtained here gave a nine parameter equation having an error of less than 20% in pressure and a two parameter with an error of less than 90% spanning the entire temperature range of liquid sulfur. Inasmuch as the B('3)(SIGMA)(,u)('-) - X('3)(SIGMA)(,g)('-) system of diatomic sulfur was studied by a multitude of researchers for well over half a century, it was decided to critique the literature. This revealed that the ground state (X('3)(SIGMA)(,g)('-)) was well understood. The B('3)(SIGMA)(,u)('-) state was perceived to be so extremely perturbed as to prohibit molecular constants determination. Scrutizing the analytics used in the past divulged that either graphic or numerical methods had been employed but not simultaneously. Creation of essential algorithms was to be the marriage of graphic and numerical methods within a cybernetic framework. The Bohr frequency condition proved to be necessary and sufficient for the construction of the theroretical principles needed for analysis to be independent of mathematical models. This enabled the creation of an algebra which when taken in conjunction with past analytics revealed that all previous analysis were one-dimensional. This algebra enabled the prediction of band structure via a simple visual template using "ball-and-stick" diagrams for the "calculation" of branches. A protocol established multi-dimensional the necessary analysis and also the consistency of data. Analysis incorporated the use of point statistics and Grubb's outlier procedure for rejecting data points. The results of the entire spectral analysis project was the characterization of the B state, the determination of B state molecular constants, and the generation of a compendium of synthetic B-X spectra for 0 (LESSTHEQ) v' (LESSTHEQ) 9 and 0 (LESSTHEQ) v'' (LESSTHEQ) 22 to within 0.05 cm('-1).
Determinants of trust and use in virtual communities
Authors:   , Ridings Catherine M. , Arinze Orakwue Bay , Gefen David
Published: July 2024

Virtual communities have become hot topic in the popular press and MIS research. Community sites are one of the fastest growing categories of Web-sites, and the virtual communities themselves are growing. Understanding virtual communities is crucial to organizations that want to tap into their enormous information potential. By sponsoring and cultivating virtual communities that give customers the ability to interact with each other and with the company itself, businesses can build new and deeper relationships with customers. Businesses can obtain demographic information about their target market and likes and dislikes regarding products. Since virtual communities are places where computer mediated communication takes place, they involve social exchange of information and social support. Trust has been found in the literature to be an essential ingredient in social exchange, and thus must be present in the virtual community. However, little empirical research exists to support theories of trust development in virtual communities and what motivates people to use virtual communities. The purpose of this research is to study trust and the motivations to use a virtual community, and the interaction between these two concepts. The results gathered from 663 virtual community members suggest that trust has two dimensions, not three as had been found previously in some other settings. Trust was composed of trust in abilities, and trust in benevolence/integrity. Responsiveness, the degree to which others confide personal information and disposition to trust were found to build trust. Stability in the community was found to be negatively related to trust, meaning that new people in the community were associated with higher levels of trust. This may indicate that new people with new ideas and contributions add an element of confidence and faith to the community. Several measures of use, such as hours spent in the community and posting behavior, were found to be influenced by the desire to exchange information and exchange social support. Finally, the moderating effects of trust on the desire-use relationship were found to be significant in very few cases, suggesting that trust does not moderate the relationship. Implications and areas for further research are discussed.
The regulation of meiotic S phase in Saccharomyces cerevisiae
Authors:   , Rice Lyndi Michelle , Nickels Joseph T
Published: July 2024

Protein phosphatase 2A is a heterotrimeric serine/threonine phosphatase comprised of two regulatory subunits and a catalytic subunit. We have found that the gene encoding one of two B regulatory subunits, CDC55, is required for meiotic progression. Mutant cells lacking CDC55 are capable of inducing the early meiotic genes, IME1 and IME2, but are defective in the expression of the middle sporulation gene, NDT80. Furthermore, we find that cdc55 cells are capable of completing intragenic recombination, but are defective in premeiotic DNA replication, intergenic recombination, harbor spindle pole body duplication and microtubule elongation defects, and are unable to sporulate. We are unable to bypass defects caused by the loss of CDC55 by deletion of genes that act at the pachytene checkpoint that monitors recombination. However, deletion of the DNA damage checkpoint gene, RAD9, allows for the partial suppression of premeiotic DNA replication and sporulation defects. Additionally, we find that deletion of CDC55 and CLB5, which encodes for the major S phase B-type cyclin, is synthetically lethal. Taken together, these data suggest that CDC55 is required at premeiotic S phase. In parallel studies, we have discovered two mutants that are able to complete several rounds of premeiotic S phase and form asci containing more than four spores, called multi-spores. Deletion of the tyrosine kinase and CDK inhibitor, SWE1, or expression of the constitutively active allele, CDC28AF, allows for the re-initiation of replication within one meiotic cycle. Multi-spores contain even and odd number of viable spores, which exhibit Mendelian segregation and are capable of homologous recombination. The Rad9p- and Rad17p-dependent checkpoints are not required for multi-spore formation; deletion of the S phase cyclin, CLB6, or the CDK inhibitor, SIC1, does not affect multi-sporulation. Interestingly, there is a requirement for the premeiotic S phase proteins, Clb5p and Cdc55p, as well as the recombination proteins, Spo11p and Rec102p, for re-replication. The fact that cdc55, swe1, and CDC28AF mutants are replication-competent during mitotic S phase but exhibit defects during premeiotic S phase suggests that mitotic and premeiotic DNA replication is regulated differently during these processes.
NMDA glutamate receptors in Alzheimer's disease
Authors:   , Eberz Amanda , Armstrong David M.
Published: July 2024

Alzheimer's disease (AD) is a multi-faceted disease that affects several neurotransmitter systems and a number of brain regions. The hippocampus, which is affected early in the disease process, is of particular interest based on observations that some hippocampal subregions and more specifically, certain cell populations within these subregions, are more vulnerable to cell death than others. While the underlying cause of this specific vulnerability is not clearly understood, excitotoxicity, mediated via ionotropic glutamate receptors, may play a crucial role. Moreover, the repertoire of glutamate receptors expressed on neurons may influence this glutamate-mediated vulnerability. Therefore, it is hypothesized that perturbations of glutamate receptor subunits may contribute significantly to the viability of the cell. N-methyl-D-aspartate (NMDA) receptor subunits were examined in subregions of the AD hippocampus in patients representing a broad range of AD pathology (mild, moderate, severe groups) using both biochemical and in situ hybridization techniques. Importantly, both protein level and mRNA expression of NR1, NR2A, and NR2B subunits were examined in the same groups of patients. Protein levels and mRNA expression for NR1 were significantly reduced in the hippocampus between patient groups. Further post hoc analysis showed a significant reduction of mRNA expression in the CA4 subregion of the hippocampus while the protein level was reduced in the subiculum. NR2B protein level and mRNA expression were reduced in moderate and severe AD groups. The NR2A subunit mRNA expression and protein level did not change throughout the disease. Cellular analysis of gene expression by grain density counts revealed a change only in NR2A subunit and showed a significant increase in the moderate group compared to mild and severe groups. This investigation provides evidence to support the hypothesis that an alteration in expression of NMDA receptor subunit may render it more vulnerable to glutamate excitotoxicity.
The psychology of the taming of the shrew
Authors:   , Sealy Roger C.
Published: July 2024

A psychological analysis of The Taming of the Shrew is presented, and its relevance to psychotherapy and to the male in present-day society considered. (i) The character of the shrew is explored and the qualities that define her are compared with those associated with representations of the negative mother derived from investigations of primitive cultures and from psychological studies. It is concluded from this analysis that the characteristics of the shrew approximate those of a primitive form of the negative mother, and it is hypothesized that the powerfully negative emotions that can be triggered by the shrew are likely to come from an association with this aspect of the internalized mother. Further examination reveals that the shrew possesses additional qualities-those of the hurt and unloved child-which are complementary to those of the negative mother. It is argued that these two sides to the shrew can be integrated within a perspective which views her behavior as the reflection of the two components of a developmental conflict. (ii) The development of the image of the shrew in the male mind is examined. Data and theories on the development of the negative female object are reviewed and the interplay between interpersonal and intrapsychic aspects explored, in assembling a picture of how the image of the shrew may develop and how it may derive its particular fascination and power. (iii) The value there might be for the male in "taming the shrew" is considered from both interpersonal and intrapsychic perspectives. It is argued that a capacity of the male to consciously be aware of, and have access to, his own shrewishness is essential if the taming is to be truly effective, and the relevance of such taming to the psychotherapy of character disorders is considered.
Modulation recognition over multipath-fading channels
Authors:   , Zhu Qiang , Kam Moshe
Published: July 2024

The objective of this study is to design a reliable and comprehensive identification algorithm for symbol constellations in digital communications, using finite-length sample sequences. Such algorithms are known as modulation recognizers and are expected to play an important role in many communication applications such as the realization of "universal" receivers, signal confirmation and interference identification, multi-drop networks, surveillance, electronic warfare and military threat analysis. Despite the fact that several studies on modulation recognition have appeared in the last fifteen years, many problems remain. Most existing algorithms cannot tackle large sets of constellations, multipath-fading channels, and constrained channels (in power, bandwidth and signal shape, etc.). The present investigation attempts to resolve some of these issues. Two classifiers are proposed here for QAM constellation identification in noise (chapter 2). They are the optimal maximum-likelihood (ML) classifier (which maximizes the average probability of correct decision) and a (non-parametric) feature-based classifier which is based on Fourier-domain analysis. The performance of these classifiers is analyzed, and trade-offs are studied between performance and the amount of information required for reliable decision-making. The non-parametric classifier is then extended to operate in multipath-fading channels (chapter 3). Then a blind equalization technique is presented. It provides preprocessing for the modulation recognizers and can also be used in improving demodulation and information retrieval. In devising this blind equalization technique, we noted that most existing blind equalization algorithms assume little about the multipath channel which they equalize. They do, however, require significant amount of information about the communicated constellation. In some applications the situation is reversed-the communicated constellation is unknown, but a multi-ray fading model can be confidently assumed. For this situation an iterative algorithm based on a non-parametric multipath channel model was developed (chapter 4). It jointly estimates the information sequence and the channel parameters over a fixed block of data in a "bootstrapping" manner. The algorithm is shown to be very effective for modulation recognition and information retrieval from the constellation set {BPSK, QPSK, 8PSK, l6QAM, 64QAM, 256QAM, 9QPR, 49QPR}, even if the order of the channel model is underestimated.
The accounting standards overload issue
Authors:   , Hiltebeitel Kenneth Merrill
Published: July 2024

The number of financial accounting standards has expanded rapidly since 1972, resulting in a concern in the accounting profession of accounting standards overload and the possible burden that it may place on the small or private company. The American Institute of Certified Public Accountants and the Financial Accounting Standards Board have expended a considerable amount of effort in evaluating the issue: Committees have been formed, invitations to comment have been circulated, and research studies have been sponsored. An empirical study, using a decision simulation design, was undertaken to determine if the modification of four financial accounting standards influenced the preliminary risk assessment or request for additional information by bank loan officers (BLOs) as they considered a request for a line of credit from a small, hypothetical company. In addition, an analysis was made of the possible effect of demographic factors on the decisions of BLOs who were asked to evaluate the usefulness of the financial statements provided to them. A set of financial statements that included modified treatments for APB No. 11 (Accounting for Income Taxes), SFAS No.13 (Acconting for Leases), SFAS No. 34 (Capitalization of Interest Costs), and excluded a statement of changes in financial position (APB No.19) resulted in a statistically significant difference in the BLOs' perceived usefulness of the financial statements. Those treatments, however, did not influence the BLOs' risk assessment or need for additional information. Several demographic factors influenced the decisions of the BLOs, the most notable being bank size. Finally, a significant correlation was found among perceived usefulness, risk assessment, and information needs. The results of the study suggest a possible approach to providing relief to the small company in complying with selected financial accounting standards, namely, disclosing information about income taxes, leases, and interest costs in the notes to the financial statements rather than in the body of the financial statements. A movement from certain complex measurement standards to less complex disclosure standards could provide the small company with some relief from accounting standards overload without denying the BLO information that BLOs perceive to be useful.
The structural features of the ligand binding site of the serotonin type 3 receptor
Authors:   , Yan Dong , White Michael M
Published: July 2024

A member of the ligand-gated ion channel (LGIC) superfamily, the serotonin type 3 receptor (5-HT₃R) is involved in many important physiological and pathological actions in both the central and peripheral nervous system. Functional studies have been conducted extensively on various aspects of this receptor, for example, regulation of the release of other neurotransmitters, pain transmission, vomiting reflex, and some aspects have been transformed into clinical applications, such as antiemetic treatment with 5-HT₃R antagonists after chemotherapy. To date, structural studies have been lacking. Consequently, the molecular basis for the functional activation of the 5-HT₃R has remained unclear until now. In the present study, we applied ligand binding assays, whole-cell patch clamping, and site-directed mutagenesis techniques, including the "alanine scan" method, to specifically target the ligand-binding domain at the N-terminal region of the 5-HT₃R. By using curare and its analogs to interact with 5-HT₃R, and then correlating with data from previous studies on the nicotinic acetylcholine receptor (nAChR), we showed a close resemblance between the ligand-binding domains of nAChR and 5-HT₃R. Using the information from the curare analog binding experiments, we focused on Trp90, which is homologous to [gamma]Trp55 and [delta]Trp57 in nAChR, and on the region neighboring Trp90. Those two tryptophan residues in nAChR have been shown to be involved in curare binding. We successfully identified Trp90 in 5-HT₃R as involved in curare and granisetron binding, Arg92 in serotonin and granisetron binding, and Tyr94 in granisetron binding only. We also determined that the secondary structure for the local region flanking Trp90 is [beta]-strand. However, further studies indicate that although this region is involved in ligand binding in 5-HT₃R, it may not come in to direct contact with the ligand. Our findings reveal for the first time evidence for the secondary structure of part of the ligand binding domain of 5-HT₃R, providing a better understanding of the ligand binding process of this ligand-gated ion channel. This understanding will facilitate the design of new 5-HT₃R ligands, with the aim of more accurate targeting and fewer side effects in their clinical usage.
Understanding the Role of Mammalian Sterile-20 like Kinase 1 (Mst1) in Cells by Identifying its Interactors
Authors:   , Rawat Sonali Jalan , Chernoff Jonathan
Published: July 2024

The mammalian Ste20-like kinase 1 (Mst1) and 2 (Mst2) are serine/threonine protein kinases that are activated in response to various apoptotic or stress stimuli, including oxidative stress. Recently, Mst1/2 has become a subject of intense investigation due its role in tumor suppression. Despite this interest, very little is known about the regulation of Mst1/2 activity and its cellular targets. In this work, we sought to learn more about the regulation and function of Mst1 by identifying its interactors. We used tandem affinity chromatography to identify novel binding partners for Mst1 under basal and oxidative stress conditions. We identified two novel interactors of Mst1, Peroxiredoxin 1 (Prdx1) and Mst2. Prdx1 was identified only under oxidative stress condition while Mst2 was identified under both non-stress and under the conditions of oxidative stress. Peroxiredoxin 1 (Prdx1) is an antioxidant enzyme that regulates the cellular redox state by reducing hydrogen peroxide to water and oxygen. We confirmed the association between Mst1 and Prdx1 by co-immunoprecipitation experiments and found that the interaction between Mst1 and Prdx1 is induced by oxidative stress. We also demonstrated that Prdx1 is a Mst1 substrate; Mst1 phosphorylates Prdx1 at three predominant sites Thr18, Thr90 and Thr183 in vitro. We further showed that phosphorylation of Prdx1 by Mst1 inactivates Prdx1, leading to accumulation of hydrogen peroxide in cells. Our results suggest that hydrogen peroxide stimulated Mst1 activates a positive feedback loop to sustain a pro-oxidative state in cells. The Mst1 interaction screen revealed another Mst1 interactor, Mst2, suggesting that Mst1 and Mst2 form heterodimers in cells. Using co-immunoprecipitation experiments, we confirmed Mst1 association with Mst2 and also identified the domain required for Mst1/Mst2 complex formation. We evaluated dissociation constants (Kdis) of Mst1/2 homo- and heterodimers and found that the Kdis of Mst1/Mst2 heterodimer is much lower than Mst1/2 homodimers. We also compared the kinase activities of Mst1/2 homo- and heterodimers and found that heterodimers have much lower kinase activity than Mst1/2 homodimers. These findings suggest that Mst1 and Mst2 can associate with one another to form Mst1/Mst2 heterodimers, which are tighter and have lower kinase activity than corresponding homodimers.
Mechanical instability of the ankle joint complex
Authors:   , Liu Wen
Published: July 2024

Injury to human ankle joint complex (a combination of the ankle and subtalar joints) is a common occurrence. Despite the type of treatment for acute injury, about 10%-30% of the patients develop chronic ankle instability. Upon long-term follow up many complaints were revealed from patients with chronic ankle instability. Current diagnostic methods are neither reliable nor accurate in detecting the mechanical instability of the ankle joint complex. Clinical studies have suggested that secondary osteoarthritis (OA) of the ankle might be caused by the abnormal joint motion due to ligamentous deficit in chronic unstable ankle, but there has been no diagnostic technique available which could objectively determine abnormal joint motion during gait for those ankles with mechanical instability. The main objectives of this study were (1) to develop an objective and reliable diagnostic tool for assessment of mechanical instability in ankle joint complex with acute injury as well as chronic symptoms, and (2) to develop a quantitative diagnostic tool for evaluation of abnormal joint kinematics during gait in the ankle joint complex with chronic mechanical instability. Total 27 patients were classified into the acute injury and the chronic instability groups. In the acute injury group, there was no significant differences in the mean ankle flexibility (in all motion directions) between the injured and intact ankles. In the chronic ankle instability group, there was a significant difference in the mean anterior drawer flexibility between the involved and intact ankles. The results indicated that mechanical instability of the ankle joint complex is correlated to ankle chronic instability, but it is not the only cause of ankle chronic instability. The results also demonstrated that mechanical instability of the ankle joint complex mostly occurred in the anterior translational motion due to the permanent damage to the anterior talar-fibular ligament. Ten healthy subjects and four patients with ankle mechanical instability in the chronic instability group were tested for ankle kinematics with gait analysis. Normative subjects had similar kinematic pattern in dorsiflexion/plantar flexion and limited range of translational motions in the ankle joint complex during gait. However, three patients with anterior drawer instability were found to have excessive anterior/posterior and medial/lateral translations in the involved ankles compared to the intact sides, and to normal ankles. The results indicated that patients with chronic mechanical instability might have excessive joint translations during level walking, which may lead to secondly ankle osteoarthritis.
Characterizing the APC/C-AMA1-substrate complex and its role in regulating meiotic progression
Authors:   , Tan Grace Sim Yuen , Cooper Katrina F.
Published: July 2024

The anaphase promoting complex/cyclosome (APC/C) is one of two main multi-subunit ubiquitin ligase (E3) complexes involved in the ubiquitylation pathway during mitosis and meiosis. By targeting the degradation of key proteins, the cell ensures its irreversible progression through mitosis and meiosis. The focus of this thesis is on Ama1p, a meiosis-specific activator of the APC/C, which acts to recruit specific meiotic proteins to the E3 ligase for ubiquitylation and subsequent degradation. To understand how the APC/C works during meiosis, we undertook analysis as to how Ama1p recognizes both the APC/C and its substrates. The known determinants for APC/C binding were not essential for Ama1p to bind to the E3 ligase complex, but were required for APC/CAmal activity. In addition, the amino terminus contains an uncharacterized region that is required for APC/C binding, but not activation, suggesting a model in which binding of Ama1p to APC/C is uncoupled from APC/C activation. Substrate specificity is also determined by the highly divergent amino-terminus of Ama1p. However, analysis of a chimeric Ama1/Hct1 protein revealed that the N-terminus region can only partially activate the APC/C, suggesting the amino terminus is sufficient for the downregulation of substrates during meiosis; however the C-terminal domain is important for other Ama1p functions. Studies with Cdc20p as a substrate of APC/CAmal reveals that its D1 destruction box motif is important for its own downregulation during meiosis, but other novel uncharacterized degradation determinants may be involved. Gaining knowledge about assembly of the APC/C-Amal-substrate complex and the mechanisms involved in regulating its temporal activities will lead to invaluable insights of how the cell controls meiotic progression.