bluuebunny/crossref_metadata_2025 huggingface dataset:
Motivational Personality Sphere and Psychoemotional Features in Patients with Drug Addiction Disorders at Different Stages of the Treatment and Rehabilitation Process (Part I)
Authors: Fadeeva E.V. , Lanovaya A.M.
Published: July 2024

The aim of the study was to analyze dynamic changes in the motivational and psychoemotional features of patients with drug addiction disorders at different stages of the treatment and rehabilitation process (TRP). The study involved 226 patients (163 men and 63 women) with narcological disorders. The following scales were used: Socrates, DASS-21 and GSE. Using the Socrates scale, results were obtained indicating: 1) significantly higher scores on the Ambivalence subscale at the early and recovery stages of the TRP in patients diagnosed with alcohol dependence (p≤0.05); 2) significantly higher scores on the total score (p≤0.001), the Ambivalence subscale (p≤0.05), and the Action subscale (p≤0.05) (p≤0.05) at the restorative and stabilizing stages of LRP, typical for women. Evaluation of the features of the DASS-21 revealed: 1) the presence of signs of moderate depression in patients with drug dependence (p≤0.01) and mild stress (p≤0.01) at the early stage of TRP were determined; 2) at the restorative stage of TRP, a higher level of depression (p≤0.01), anxiety (p≤0.05) and stress (p≤0.001) was detected in the group of patients with drug dependence. The analysis of the results obtained will make it possible to provide targeted assistance to patients with drug use disorders and increase the effectiveness of psychological and psychotherapeutic interventions in clinical practice.
A technique for assessing foot kinematics and plantar surface characteristics during stance for varying arch structures
Authors:   , Roposh Carolyn Michelle , Seliktar Rahamim
Published: July 2024

Clinical knowledge provides a framework for assessing the influence of the foot's arch structure on foot kinematics and plantar surface properties. However, attempts to quantify this relationship have resulted in conflicting outcomes and rely on inconsistent methodology. In this work, a technique was developed to examine foot mechanics and plantar surface characteristics during the stance phase of gait in individuals with different arch structures. Twenty-one subjects were categorized by arch height and flexibility and walked over a pressure mat while motion capture technology detected reflective markers placed on their feet. The trajectory data were used to analyze foot kinematics and calculate the relative deformation of the plantar surface in the vertical direction during walking. The force data were coupled with vertical position data to generate load-deformation curves of the plantar surface that depict the compression and relaxation of the plantar surface. The curves examine the changing stiffness during stance, the overall stiffness and dampening coefficients, and energy dissipation percentages. A generalized standard linear model was used to analyze statistical differences (p<0.05) with body mass index as a random effect parameter. The kinematic results showed statistical differences in mean and range between varying arch heights in the coronal tibia-heel rotations during the loading response and pre-swing, and the transverse plane during midstance and terminal stance. Arch flexibility statistically affected the coronal plane of the heel-tibia rotations during the loading response and midstance, and first metatarsal-midfoot rotations during terminal stance. The plantar surface characteristics showed statistical differences between varying arch heights in the stiffness and dampening properties under the fifth metatarsal, dampening of the midfoot, and energy dissipation ratio of the first metatarsal. There were statistical differences between varying arch flexibility structures in dampening of the midfoot and fifth metatarsal. Our results support kinematic differences in foot motion due to the arch structure, and the utility of combined plantar forces and kinematic data to depict load-deformation curves to detect differences in foot function during gait in varying arch structures. Overall, this technique assesses structural components of the plantar surface and functional mechanisms of foot motion to provide advancement in foot biomechanics research.
Art world maps
Authors:   , Stagg Deborah Bolton
Published: July 2024

The objective of this research is the automatic style-classification of artists via relationships in the literature between artist-pairs and the graphical depiction of the relationships in a two-dimensional map. This research applies the co-citation methodology, developed and validated for mapping the structure of the science and social science literatures, to the literature of the visual arts. Co-mention, a co-word measure, is substituted for the co-citation unit of analysis. The study derives style structure from the visual arts literature using the multivariate techniques of cluster analysis, factor analysis, and multidimensional scaling applied to co-mention matrices derived from two bibliographical databases, Art Literature International (RILA) and Arts & Humanities Search[registered]. The co-mention methodology is validated by the comparison of the classification produced by each of the two source databases with the independent qualitative classification of artists synthesized by Diana Crane in her book The Transformation of the Avant-Garde: the New York Art World, 1940-1995, from the major critics and historians of the period. The Rand Index, Rg, provided a metric for comparison of the groupings obtained and produced ratings xindicating very good agreement between each of the database-generated classifications and the qualitative synthesis (3-D RILA and synthesis: Rg = 0.8873; 3-D AHCI and synthesis: Rg = 0.8297), as well as between the two quantitative classifications (Rg = 0.8070). Additional support for the validity of the method can be seen from the consistency of the structures produced by the three different quantitative techniques. The multidimensional scaling produced maps which provide coherent displays of the structures (RILA: 3-D RSQ = 0.799, stress = 0.170; AHCI: 3-D RSQ = 0.758, stress = 0.188). SPSS's INDSCAL scaling model of the ALSCAL procedure was used to compare the two maps and indicated a moderately good fit (3-D RSQ = 0.604, stress = 0.240). Graphical depiction of style groupings appears generally consistent among the maps and Crane classification; deviations from the expected groupings are interpretable, augmenting the understanding of style or movement affiliation.
Rheoencephalography in simulated aviation environment stress
Authors:   , Shender Barry Scott , Dubin Stephen E
Published: July 2024

The use of electrical impedance plethysmography of the head, or Rheoencephalography (REG), has been demonstrated in a high acceleration stress environment on human volunteer subjects. Acceleration stress was applied in the head-to-foot direction and is referred to as +Gz. The REG instrument divides the cephalic impedance waveform into two components: (1) a baseline impedance signal, Zb, that is referable to the bulk movement of blood in and out of the head, and (2) a pulsatile impedance waveform that is heart beat coincident. The REG waveform also contains information about cerebrospinal fluid (CSF) volume changes and shifts resulting from the application of acceleration stress. Blood and CSF shifts in and out of the cranial and spinal compartments impinge directly upon the overall function of the central nervous system. The high acceleration environment provides an ideal arena in which to noninvasively alter cephalic fluid volumes in order to obtain basic physiologic knowledge of importance to both aviation and clinical medicine. This information has been obtained in a noninvasive, safe, convenient, and unobtrusive manner on the Naval Air Development Center (NADC) human centrifuge. Using data derived from three different sets of human experiments conducted in a high +Gz environment have led to the characterization of the changes in the REG waveform that occur with increasing acceleration load. Alterations in the Zb waveform indicate its utility as an aid in determining the effectiveness of anti-G protective devices, such as reclining aircraft seats, and anti-G techniques, such as anti-G straining maneuvers. Use of the Zb waveform provides the first indirect (or direct) estimate of the bulk movement of blood under a +Gz load as predicted by the hydrostatic column theory of the physiological response in increasing acceleration load. An outline for animal and human experimentation necessary to develop a mathematical model to describe the changes in both vascular and CSF compartments is presented.
Diastereoselective reductions of cyclic N-diphenylphosphinyl imines to N-diphenylphosphinyl amines using amine boranes
Authors:   , Rutkowsky Susan A. , Hutchins Robert O.
Published: July 2024

Part I. Various amine boranes were used in the reduction of substituted cyclic N-diphenylphosphinyl imines to the corresponding N-diphenylphosphinyl amines, which represent protected primary amines. t-Butylamine borane in methanol appeared to be the most efficient amine borane reagent to accomplish diastereoselective reductions. For reductions of 3- and 4-substituted cyclohexyl systems, this reagent showed a strong preference for axial attack to give the equatorial (trans) isomers. Results with 2-substituted cyclohexyl systems varied depending on the substituent, although all showed a preference for the trans isomer. Cyclopentyl and bicyclic imines were attacked from the less sterically hindered face. Part II. Attempts to synthesize alkylphosphinyl imines from oximes using diphenylchlorophosphine and triethylamine at -50° C led instead to the corresponding phosphinyl enamides, which are apparently more thermodynamically stable. Attention was then turned to the utilization of the phosphinyl enamides in Diels-Alder cycloaddition reactions. This section describes the results.
The attenuation of auditory neglect by implicit cues
Authors:   , Coleman Allen Rand
Published: July 2024

The following study examined the influence of verbal implicit cues on perception of auditory stimuli among patients suffering a lesion of the right hemisphere and auditory neglect of sound perceived by the left ear (N = 16). Because the language centers are intact among these patients, it was hypothesized that certain verbal stimuli presented dichotically would attenuate neglect phenomena. The selected patients were administered an experimental dichotic listening test comprised of six types of word-pairs, including unrelated word pairs, synonyms, antonyms, categorically related words, compound words, and rhyming words. Words that were semantically related, such as synonyms, antonyms, categorically related words, and compound words were more accurately perceived than unrelated words. Rhyming words were less accurately perceived than unrelated words. These findings suggest that the perception and awareness of auditory information is strongly affected by the specific content conveyed by the auditory system. Language centers will process a degraded stimulus that contains salient language related content. In general, these findings suggest that auditory neglect phenomena involve a complex interaction of intact and impaired processing centers in the brain with content that is selectively processed by these centers.
Coupled heat transfer and fluid flow analysis in the Hazelett twin-belt caster
Authors:   , Kim Yoon-Gi , Apelian Diran , Farouk Bakhtier
Published: July 2024

The twin-belt (Hazelett) process incorporates two cooled continuously moving thin metal belts wrapped around pulleys which tension and drive the belts at a predetermined speed. A coupled heat transfer and fluid flow mathematical model was developed which describes the twin-belt casting process to predict the metallurgical integrity of the cast product, as well as to evaluate process variable effects on the cast product. The k-e turbulence model was used to calculate turbulent viscosity in the melt pool. In addition, heat flux data at belt surface has been experimentally measured and used as boundary conditions for the heat transfer model. Lastly, a model has been developed which describes inclusion trajectories in solidifying slab using theoretical principles. The resultant differential equations were solved numerically using a Digital computer. The process variables considered were the belt speed, nozzle width and cooling conditions of the belt. 3105 and 5182 aluminum alloys, and 1020 steel were considered as cast metals. It was expected that the variation of computed cell size across the thickness of the aluminum alloys would be small in comparision to the steel slab castings. Effects of casting speed on the cooling rate and cell size of aluminum alloys become prominent when the temperature interval of mushy zones increase. Calculated inclusion trajectories indicate that it is difficult for inclusions to float and be absorbed in slag in the Hazelett type horizontal type caster. As indicated earlier, inclusions can significantly affect the quality of products from horizontal casters such as the twin belt caster. This paper demonstrates models for idealized process controls and the optimization of the integrity of the cast slab.
Complications of attention-deficit hyperactivity disorder among cocaine abusers
Authors:   , Mountain Kimberly C.
Published: July 2024

Studies which have addressed the comorbid psychopathology in samples of substance abusers have found significantly higher rates of ADHD among cocaine abusers. The self-medication theory suggests that individuals with ADHD may be more likely to abuse cocaine because of its stimulant properties. Studies which have examined cocaine abusers with histories of ADHD have found these individuals to be younger at presentation for treatment, and to report an earlier onset of cocaine use, more severe polysubstance use, and a greater involvement in treatment. In addition to drug use history, this study investigated the relationship between reports of ADHD and emotional, psychosocial, neuropsychological, and occupational functioning. Forty-four percent of the sample endorsed symptoms of ADHD consistent with the DSM-IV diagnosis. Individuals in this sample who met diagnostic criteria for ADHD began using cocaine at an earlier age, used for a longer period of time, and reported shorter periods of abstinence obtained in the past. Additionally, the average period of previous full-time employment reported by subjects in the ADHD group was only half of that reported by subjects in the non-ADHD group. Subjects in the ADHD also reported more symptoms of depression, a greater number of previous psychiatric hospitalizations, and a greater number of days in the past month troubled by emotional problems. Neuropsychological performance of individuals in both groups was impaired. The only tests on which subjects in the ADHD group performed significantly worse were the Digit Span and Wisconsin Card Sorting tests. Results of a discriminant function analysis revealed that a combination of the following variables: subjects' reports of emotional difficulties, age of onset of cocaine use, and previous employment history correctly classified 72% of the cases into either the ADHD or non-ADHD groups. By increasing our knowledge of the emotional, social, occupational, and cognitive functioning of cocaine abusers, researchers and clinicians will be better able to develop and implement treatment programs suited to the needs of these clients. Further, the matching of client variables with treatment services may prove to enhance treatment outcome.
Development and validation of the lifetime history of impulsive behaviors interview and self-report measures
Authors:   , Schmidt Catherine A. , Coccaro Emil F.
Published: July 2024

The purpose of this study was to construct and validate an interview and a self-report measure of clinical impulsivity. In the first study, items were written and revised based upon a thorough literature review, domain sampling, and expert consultations. Item analyses were performed by expert panel ratings and through administration of the scales to 20 subjects. The results of the item analysis were used to determine which items were the most relevant and useful. These items were retained for the second part of the study in which both the reliability (inter-rater and test-retest reliability) and validity (construct, concurrent, and discriminant validity) of the measures were assessed. Forty-two personality disordered and 20 control subjects participated by completing both versions of the Lifetime History of Impulsive Behaviors (LHIB), several self-report measures of impulsivity, depression, anxiety, and social desirability, and laboratory measures of impulsivity. Both versions of the LHIB demonstrate good to excellent internal consistency and test-retest reliability. Additionally, both versions are associated with other self-report measures of impulsivity. Differences in scores on both versions of the LHIB were found between diagnostic groups. No relationship was obtained between either version and laboratory measures. Finally, evidence of discriminant validity was mixed, with the LHIB demonstrating a relationship with depression and anxiety, but little association with a measure of empathy. Although additional examination is warranted, the results suggest that both versions of the LHIB appear to be promising instruments for use as either an alternative or complement to other measures of impulsivity.
Acid hydrolysis of corn stover in a concentrated slurry system
Authors:   , Teng Kwuang-Fo
Published: July 2024

The objective of this research was to characterize the hydrolysis kinetics of corn stover using sulfuric acid as the catalyst in a concentrated slurry. The kinetic data were obtained in a specially constructed continuous flow reactor with an in-line sampling system. The scope and range of experimental variables included temperature (200 to 220(DEGREES)C), acid concentration (0.3 to 1.4 N), liquid-to-solid ratio (1.75:1 to 7:1 ml/g) and reaction time (0 to 35 s). It is found that glucan hydrolysis follows a zero order kinetic in the range of experimental variables investigated. Both acid concentration and temperature increase the rate of glucan hydrolysis. A rate expression for glucan hydrolysis is developed both on the basis of adsorbed acid and bulk acid concentration. A kinetic model is proposed for the reaction: Glucan (-[right arrow]) Glucose (-[right arrow]) 5-hydroxymethyl-2-furaldehyde (-[right arrow]) Levulinic Acid and for the reaction: Glucose (-[right arrow]) Other degradation products. An integral approach is used to determine the parameters in the kinetic model and their numerical values are found to be comparable to those reported in the literature. It is found that at a given temperature, acid concentration and glucan conversion, there is an optimum liquid-to-solid ratio which maximizes glucose concentration. It is shown experimentally that glucan hydrolysis is not mass transfer limited at as low a liquid-to-solid ratio as 2.5:1.
Mutational and topological analysis of Fks1
Authors:   , Johnson Michael E. , Edlind Thomas D
Published: July 2024

Echinocandins represent a new antifungal group with potent activity against most Candida and Aspergillus species. These lipopeptides inhibit synthesis of [beta]-1,3-glucan, a major cell wall polysaccharide. Rare acquired resistance is associated with mutations in two "hotspot" regions of Fks1 or Fks2, the probable [beta]-1,3-glucan syntheses. Intrinsic resistance of fungi such as Fusarium, Scedosporium, and Cryptococcus species represents a major limitation. Here, we explored the basis for echinocandin resistance using Saccharomyces cerevisiae as a model. Previously characterized mutations confer cross-resistance; we screened for mutations conferring differential resistance, consistent with a direct interaction of that residue with a variable echinocandin side chain. One mutant (fks1[delta] background) exhibited [greater than or equal to]16-fold differential resistance to micafungin versus caspofungin. Sequencing revealed a novel double mutation, W714/Y715N, in a previously uncharacterized region of Fks2. Equivalent (W695/Y696N) and related mutations in Fks1 confirmed the role of new "hotspot 3" in resistance. Further mutagenesis expanded hotspot 3 to residues 690-700, yielding phenotypes including differential resistance, cross-resistance, and hypersensitivity. Fks1 sequences from intrinsically resistant Scedosporium species revealed W695F-equivalent substitutions; Fks1 hybrids expressing Scedosporium prolificans hotspot 3 confirmed this substitution imparts resistance. With evidence of direct Fks1-echinocandin interaction, we turned our attention to where and how this interaction occurs. Since Fks1 is an integral membrane protein and echinocandins are cyclic peptides with lipid tails essential to their activity, protein topology is key to understanding the Fks1-echinocandin interaction. To address this, we used a Suc2/His4C reporter fused to a series of C-terminal truncations to experimentally define Fks1 topology in S. cerevisiae. Of the 15-18 transmembrane helices predicted in silico, 13 were experimentally confirmed. The N-terminus (residues 1-445) is cytosolic and the C-terminus (residues 1823-1876) external; both are important for Fks1 activity. The cytosolic central domain (residues 715-1294) includes newly recognized homology to glycosyltransferases; residues potentially involved in catalysis and UDP-glucose binding are essential. Importantly, all three hotspots are external, with hotspots 1 and 2 adjacent to and hotspot 3 largely embedded within the outer leaflet of the membrane. This topology suggests a model where echinocandins interact through their lipid tails with hotspot 3 and through their cyclic peptides with hotspots 1 and 2.
Biological role and regulation of pur-[alpha]
Authors:   , Muralidharan Vandhana , Khalili Kamel
Published: July 2024

Progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease of the human central nervous system (CNS) is caused by the replication of the human neurotropic virus, JCV. An early viral protein, JC large tumor (T)-antigen, mediates JC viral replication and the assembly of viral particles. JC T-antigen transgenic mice developed severe dysmyelination with reduced myelin basic protein (MBP) levels, suggesting the importance of T-antigen in JCV induced PML. Transcription factors that regulate MBP gene expression were investigated as one of the possible mechanisms through which JC T-antigen causes dysmyelination. Pur-[special characters omitted] is a transcription factor that upregulates MBP (myelin basic protein) promoter expression in in vitro assays. Pur-[special characters omitted] protein associates with JC T antigen in hamster glial cells as demonstrated by immunoprecipitation. This led to the hypothesis, 'the abrogation of the function of Pur-[special characters omitted] as transcription factor for MBP gene expression by T antigen could lead to demyelination in PML'. To test this hypothesis, Pur[special characters omitted]-/- mice were created and their myelin status was analyzed. Pur-[special characters omitted] null mice survived the embryonic development. However, around postnatal day 14, they exhibited slack posture, kyphosis, resting tremors, growth retardation and eventually died around day 25. This demonstrates that Pur-[special characters omitted] is not essential for the embryonic survival of the mice, but vital for the survival of adult animals. Compared to the wild type mice, Pur-[special characters omitted]-/- mice did not show any significant difference in the (i) levels of MBP, PLP and MAG mRNA by Northern analysis; (ii) distribution and in the amount of MBP protein by MB immunohistochemistry; (iii) amount of MBP mRNAs from the sciatic nerve and spinal cord as demonstrated by quantitative RT-PCR. The above analysis demonstrated that Pur-[special characters omitted] is not an essential transcription factor for MBP gene expression. Since Pur-[special characters omitted] deficient mice exhibited normal myelination, it was concluded that inactivation of Pur-[special characters omitted] alone by T antigen is not sufficient to cause demyelination in PML. Parallely, the transcriptional start site of Pur-[special characters omitted] gene was identified. The promoter fragment of Pur-[special characters omitted] gene was characterized and negative regulation of Pur-[special characters omitted] on its own promoter was identified demonstrating the negative auto regulation of Pur-[special characters omitted].
The mechanisms of scavenger receptor (SR)-BI-mediated lipid uptake from high density lipoprotein
Authors:   , Thuahnai Stephen Thuahliansang , Lund-Katz Sissel , Phillips Michael C.
Published: July 2024

Scavenger receptor class B, type I (SR-BI) is the first molecularly defined receptor for high density lipoprotein (HDL). Cholesteryl esters from HDL enter cells in a selective manner without whole particle uptake. The mechanism of this selective uptake pathway remained largely unknown until the discovery of SR-BI. Lipid uptake via SR-BI involves two steps. The first step is the binding of the lipid donor particle to SR-BI and the second step is the movement of lipids from the SR-BI-bound lipid donor particle to the cell. In this dissertation, the molecular mechanisms of SR-BI-mediated HDL lipid uptake were examined. There were three specific aims in the project: Aim 1 examined the binding of various components of HDL to the receptor; Aim 2 compared the selectivity of the receptor for various HDL lipids: and Aim 3 focused on the consequence of lipid uptake from apolipoprotein-free lipid donor particles. The results show that the binding of a lipid donor particle to SR-BI and the movement of lipid into cells are linked processes. Quantitative comparison of various HDL components show that binding to the receptor can be mediated either by the lipid or protein component of the lipoprotein. Examination of binding using apolipoprotein A-I peptides and synthetic peptides show that a recognition motif on HDL is the amphipathic [alpha]-helix in apolipoproteins. Selective transfer of lipid from the SR-BI-bound lipid donor particle requires these amphipathic [alpha]-helices. If the binding to the receptor is mediated by an apolipoprotein-free lipid donor particle (e.g. phospholipid unilamellar vesicles, lipid emulsion), then the lipid movement into the cells via SR-BI is stoichiometric (i.e. non-selective transfer occurs), consistent with fusion of the lipid donor particle with the cell membrane. A low activation energy for CE selective uptake from the SR-BI-bound HDL to the cell membrane suggests that a non-aqueous channel is involved in this process. The putative hydrophobic channel created by SR-BI is able to accommodate the movement of all the major HDL lipids into cells with the relative rates of uptake of lipids being in the order cholesterol > cholesterol esters > triglycerides > phospholipids. Overall, these results provide new insights into the molecular mechanism of the last stage of the reverse cholesterol transport pathway, by which HDL returns cholesterol from the periphery to the liver.
The contribution of higher-level visual processes to everyday functional activities in Alzheimer's disease (AD)
Authors:   , Jefferson Angela Lee , Barakat Lamia , Glosser Guila
Published: July 2024

Declines in functional status (i.e., activities of daily living (ADLs) which include instrumental activities of daily living (IADLs) and basic-self care activities of daily living (BADLs) are a necessary feature of a dementia diagnosis. Furthermore, such declines are associated with decreased quality of life, institutionalization risk, and death for patients as well as increased caregiver burden. Thus, understanding the cognitive correlates of functional status in individuals with dementia, and specifically Alzheimer's disease (AD), is important. The present study explored relationships between cognitive capacities and performance of everyday activities among patients with dementia. The contribution of memory and executive dysfunction (two well studied areas) as well as higher level visual perceptual processes (a less well studied domain) to overall ADL functioning was examined in a group of patients diagnosed with probable AD. Contrary to predictions, memory, executive dysfunction, nor visuoperceptual abilities contributed significantly to impairments in ADLs when cognitive status was taken into account. Rather, a global measure of dementia severity was the only significant predictor of overall ADL performance, accounting for 35% of the variance in a regression model. This finding is consistent with the results of a number of other investigations (e.g., Giovannetti et al., 2002). Furthermore, it is consistent with the resource theory (Schwartz et al., 1998), which proposes that naturalistic actions, such as ADLs, demand cognitive resources. A depletion of these resources results in naturalistic action impairments and difficulties. Thus, the more limited the cognitive resources, the more difficulty one will experiencing when performing an ADL task. Given the multi-factorial nature of functions assessed in a composite index of ADLs, it may be that these are best predicted by more global measures of overall cognitive ability, rather than discrete cognitive capacities. Further investigations may examine whether impairments in more specific functional activities are associated with deficits in discrete cognitive domains.
Psychopathy in a noninstitutionalized population
Authors:   , DeMatteo David , Heilbrun Kirk
Published: July 2024

This study examined the construct of psychopathy in a sample of 54 participants recruited from the general community population of the greater Philadelphia metropolitan area using an empirically-validated and widely-accepted measure of psychopathy-the Psychopathy Checklist-Revised (PCL-R). This study compared the data obtained from the present sample to the PCL-R normative data, which provided a direct comparison between institutionalized and noninstitutionalized individuals with elevated levels of psychopathic characteristics. This study also examined the role of specified protective factors among the participants with elevated levels of psychopathic characteristics, including their relationship to PCL-R scores and three measures of antisocial behavior. Another purpose of this study was to evaluate the utility and effectiveness of the methodology for locating, recruiting, and studying individuals from a noninstitutionalized population with elevated levels of psychopathic characteristics. The results indicated that the methodology effectively located individuals from the general community population with moderately elevated levels of psychopathic characteristics. The results indicated that the participants in the High Psychopathic Group exhibited the core personality features of psychopathy, but not the core behavioral features of psychopathy. A comparison between the present data and the PCL-R normative data revealed that the present sample differed significantly from the correctional samples included in the PCL-R normative studies. The results indicated that there is a demonstrable relationship between PCL-R scores and the number of protective factors for the participants in the High Psychopathic Group. When using a conservative approach to measure the presence of protective factors, there was a significant negative correlation between the number of protective factors and PCL-R scores for the participants in the High Psychopathic Group. The results indicated that there was no statistically significant relationship between the number of protective factors and three measures of antisocial behavior (i.e., number of arrests, number of MacArthur arrests, and number of sub-arrest MacArthur offenses) for the participants in the High Psychopathic Group. Finally, the results indicated that the number of protective factors and the severity of current substance abuse were not significant predictors of the three measures of antisocial behavior for the participants in the High Psychopathic Group.
Removal of solid inclusions from steel melts
Authors:   , Ali Sabit
Published: July 2024

The removal of non-metallic inclusions from steel melts prior to casting has much merit both financially and technologically. Laboratory prepared steel melts have been successfully filtered through an alumina filter bed to remove carefully prepared alumina inclusions at 1600(DEGREES)C. Three distinct types of filters have been used in this investigation: (i) tabular alumina (0.2-0.5 cm size) packed bed (ii) extruded monolithic alumina (400 square cells/sq. in.) and (iii) open pores alumina foam (10 and 30 pores per linear inch). Filter heights of 5, 10 and 15 cm and melt velocity range of 0.08 to 0.58 cm/s have been used in this investigation. The steel cleanliness has been characterized both quantitatively and qualitatively. Chemical and quantitative metallographic analyses were performed for the filtered and unfiltered steel. In chemical analysis, total oxygen, total aluminum, soluble aluminum and insoluble aluminum contents were determined, while in quantitative metallographic analysis, volume fractions of alumina inclusions and their size distributions were determined. The kinetics of the filtration process have been modeled and inclusion removal efficiencies up to 96% have been achieved. The inclusion removal efficiency is indluened by the melt velocity, the type of filter, the length of the filter and the total surface area of the filter. Out of the above variables, melt velocity and total surface area of the filter play a dominant role in melt filtration process. The inclusion removal efficiency has been found to decrease with an increase in melt velocity and to increase with an increase in the total surface area of the filter. For a given filter height and melt velocity, the monolithic alumina filter yields a cleaner steel than the tabular alumina filter. The alumina inclusions present in unfiltered steel melts are < 5 microns in size and in most of the filtration experiments inclusions greater than 2.5 microns are totally removed from the melt. A good correlation has been found between the filtration performance results obtained from chemical analysis and quantitative metallographic techniques. The inclusion capture kinetics and filtration characteristics of the filter media tested have been discussed.
Limit cycle analysis of multivariable nonlinear dynamic systems
Authors:   , Piper George Edward , Kwatny Harry G
Published: July 2024

The analysis of limit cycle behavior in multivariable nonlinear systems and systems containing multiple nonlinear elements is examined. Characterization of limit cycle behavior about an isolated equilibrium is provided by the Hopf bifurcation theorem. Interpreting the Hopf bifurcation theorem in the frequency domain is discussed and a frequency-domain version of the Hopf bifurcation theorem is presented. The frequency-domain version of the Hopf bifurcation theorem provides a convenient method of establishing the existence and stability of a limit cycle in multivariable nonlinear systems. In conjunction with the study of two nonlinear dynamical systems, analytical techniques have been applied and enhanced to understand the behavior of limit cycles. Parametric instabilities in electric power networks associated with Hopf bifurcations are studied via the frequency domain version of the Hopf bifurcation theorem. The analysis of a flutter instability of a three machine, four bus electric power network has been completed by showing that the encountered instability is a subcritical Hopf bifurcation. The analysis emphasized the feasibility for application to systems of large scale and more complex models. The oscillatory behavior of a spacecraft attitude control system is investigated. It is shown that a commonly used, momentum exchange, spacecraft attitude control configuration gives rise to complex nonlinear behavior involving multiple limit cycles and strange attractors. The results are based on the analysis of a simple single axis problem.
Finite element simulation of segmented chip formation in high-speed machining
Authors:   , Hashemi Javad , Chou Pei Chi
Published: July 2024

This thesis presents the modification and application of a version of the finite-element code, DEFEL, for modeling segmented chip formation in high-speed machining processes (HSM). In HSM three different types of chips can be formed: continuous, segmented, and continuous with a built-up edge. In this research the mechanics of formation of segmented chips is simulated. A new slide-line algorithm and a fracture algorithm were developed which simulated the automatic generation of cracks and interaction of contacting surfaces. Three criteria for crack formation were implemented. The fracture criteria available are based on maximum principal stresses, maximum shearing stresses or maximum effective plastic strain respectively. DEFEL is capable of analyzing large changes in geometry and is effective in calculating the stress and deformation. The addition of the slide-line generation routine to the DEFEL code gives it the needed capability to simulate the segmented chip formation of material in high-speed machining processes. The modification of DEFEL and the implementation of the slide-line and fracture algorithms are the main contributions of this thesis. A plane strain simulation of orthogonal metal cutting process with elastic-perfectly plastic material and frictionless boundary conditions was performed in which a cutting speed well within the high speed range was used (1000. in/sec). DEFEL successfully simulated the formation of segmented chips at high speed. The results have been compared with existing experimental data, analytical solutions, and numerical results. It is concluded that his version of DEFEL is capable of modeling the process of machining. Addition of more accurate material models and friction simulation will further improve the results.
Nanocomposite Hydrogel with Polycaprolactone Single Crystal-Directed Silica Nanoparticle Assembly
Authors:   , Lau Hang Kuen , Li Christopher Y.
Published: July 2024

Hydrogel has been widely studied in biomedical applications because of its similarity to extracellular matrix (ECM) that enables cell attachment, growth and tissue development. The high water content and high swelling ratio of hydrogel allow essential nutrient diffusion into the matrices and make hydrogel ideal for tissue engineering applications. Much stronger hydrogel is required for cellular growth. To this end, composite hydrogels with different fillers, including nanoparticles, fibers and two dimensional (2D) clays, have been developed to improve the mechanical properties ofthe system. In such systems, nanoparticle assembly is critical to the hydrogel mechanical properties, and it has not been addressed in the field. In this thesis study, we used a 2D polymer single crystal to guild silica nanoparticle assembly in a model hydrogel system. Polycaprolactone PCL)-silica hybrid filler was fabricated by directing silica orientation using the PCL single crystal as a template. The PCL-silica hybrid was incorporated in polyacrylamide hydrogel through in-situ free radical polymerization. Mechanical properties and water swelling of the hydrogel have been systematically correlated to nanoparticle assembly and will be discussed in detail.
A parametric study of the evolution of microporosity in Al-Si foundry alloys
Authors:   , Tynelius Karin Elisabeth , Apelian Diran , Major James Frederick
Published: July 2024

Experimental data has been collected over a wide range of alloying and processing conditions in A356 alloy. A multiple regression analysis has been performed to correlate the casting parameters to the size and quantity of microporosity observed in the samples. It has been found that the hydrogen content had the strongest influence on microporosity, and that both local solidification time and the local thermal conditions in the casting contributed to the final amount, size and shape of the pores. A hypothesis has been proposed which suggests that the pore growth is diffusion controlled. Factors that influenced the pore nucleation conditions, e.g. oxide inclusions and strontium content, have also been found to be important to the porosity. The relations describing pore size and total fraction porosity have shown quantitative differences. Finally, previous assumptions used for modeling of porosity have been critically evaluated, and an outline for a new approach to mathematical modeling has been established.
The neuropsychology of sexual consent
Authors:   , Kennedy Carrie Hill , Zillmer Eric
Published: July 2024

The question of sexual consent capacity is a difficult issue for psychologists and providers, when dealing with individuals with cognitive impairments. A struggle exists, between promoting rights and protection from harm, when cognitive impairments interfere with the ability to make informed decisions. The current study examines the consensus of psychologists as to the criteria that make up sexual consent; how those criteria relate to the Sexual Consent and Education Assessment (SCEA); and the sensitivity of neuropsychological indices as they relate to the construct of sexual consent. In the first phase of the study, 305 licensed psychologists completed a 56-item questionnaire regarding their opinions about sexual knowledge and safety skills. A factor analysis revealed five factors: Factor 1 - Consequences of Sexual Activity, Factor 2 - Essential Sexual Knowledge, Factor 3 - Unessential Sexual Knowledge, Factor 4 - Safety for Self and Others, and Factor 5 - Basic Safety Skills. In the second phase of the experiment, 64 individuals with mental retardation were given the SCEA and surveyed regarding sexuality education and other sexuality-related issues. Additionally, a neuropsychological test battery was administered in order to evaluate the sensitivity of neuropsychological tests in relation to sexual consent. Executive measures (i.e., a tower task, card sorting, and word fluency) were found to be primarily associated with sexual consent capacity.
The impact of the locus coeruleus efferent pathway on thalamic and cortical sensory neuron response properties in the awake rat
Authors:   , Devilbiss David M. , Waterhouse Barry D.
Published: July 2024

The nucleus locus coeruleus (LC) and its norepinephrine (NE) containing efferent system have been implicated in modulating arousal states and attentional processes. The goal of this work was to characterize the impact of tonic and phasic LC system output on simultaneously recorded target neurons of the somatosensory thalamus and cortex in the awake behaving rat. The general hypothesis tested in this dissertation is that electrical or chemical manipulations of LC neuron output over the physiological range of tonic discharge frequencies, alters sensory-evoked response properties of target thalamic and cortical neurons recorded simultaneously in the awake freely moving rat. The first portion of this research was to develop a set of techniques to record the effects of pharmacological or electrical manipulations of the LC on sensory evoked responses of many simultaneously recorded single neurons along the trigeminal somatosensory system of the awake freely moving rat. The second portion of this research characterized the effects of tonic LC stimulation on the magnitude and latency of whisker pad stimulus-evoked responses. Target cells at the thalamic and cortical levels of the rat trigeminal somatosensory pathway primarily demonstrated either an augmentation or a suppression of the stimulus-evoked discharge over the range of LC stimulus frequencies tested. The third portion of this research characterized the effects of systemic and local administration of the alpha-2 adrenergic receptor agonist clonidine on whisker pad stimulus-evoked response firing rates and latencies. These treatments resulted in the preferential augmentation of stimulus-evoked discharge for thalamic and cortical neurons. The fourth portion of this research characterized the effects of phasic LC electrical stimulation on whisker pad stimulus-evoked response firing rates and latencies. Target somatosensory cells of the thalamus and cortex demonstrated augmentation or a suppression of the stimulus-evoked discharge in equal proportions following phasic LC stimulation. The results of these studies suggest that LC output mediates changes in sensory information processing at the cellular level and that these changes are likely to enhance sensory signal detection and discrimination in the behaving animal. Moreover, the work provides a perspective on how a broadly projecting brainstem modulatory system can coordinately influence signal transmission at multiple stages of a complex, ascending sensory network. (Abstract shortened by UMI.).
A bibliometric analysis of pharmaceutical research
Authors:   , Koenig Michael E. D.
Published: July 2024

This study bibliometrically examines the research process of U.S. based for-profit pharmaceutical companies (pharmcos). The comparative performance of bibliometric analysis versus expert judgement in predicting research performance was examined, in an arena which may be uniquely capable of permitting such an examination. For each pharmaceutical company, the drug as output of the research process was examined, and for each company composite research output scores were calculated based on that company's drug output (1965-1976). These research production scores normalized by research budget as an indicator of research organizational size produced an indicator of research productivity, an output/input ratio. For drug research performance, the best and most consistent predictors in general were the number of clinical articles, and in particular highly cited clinical articles. In general there was a tendency for bibliometric indicators to perform better than expert judgements in predicting research performance. The expert judgements appeared to depend to a high degree upon the bibliometric variables, in a subject specific fashion related to the scientific discipline of the judges. Regression techniques indicated an initial factor of bibliometric size, and a seconary factor of bibliometric quality. This corroborates and extends the earlier (1978) results of Anderson, Narin and McAllister, demonstrating the phenomenon in a much more robust fashion. Pharmco articles were found to be highly cited, particularly in the area of biomedical research, where they appear to be on a par with NIH funded medical school articles. This has implications for science policy, as it indicates that pharmaceutical research may have scientific outputs that are of far broader utility than just to the pharmaceutical company concerned, outputs that policy formulation may wish to encourage.
The role of social support in psychosocial outcome following traumatic brain injury
Authors:   , Gayda Christine Anne , Williams Joseph M
Published: July 2024

The purpose of the present study was to investigate the role of social support in predicting employment status, independent living, and participation and satisfaction in social activities following traumatic brain injury (TBI). Fifty individuals who had sustained a TBI one year ago or more participated in the study. Subjects completed several questionnaires assessing perceived social support, employment status, living situation, and satisfaction and participation in social activities. The investigator completed measures assessing the subject's physical and cognitive functioning. The results indicated that perceived social support predicted overall satisfaction and participation in social activities. The hypothesis that social support would act as a "moderator" in buffering the effects of deficits in physical and cognitive functioning was supported. Females reported greater satisfaction and participation in social activities than males. The findings suggest that perceived social support may be an important first step in evaluating those factors which may impact a person's social life following TBI. Further research with a larger and more heterogeneous sample is suggested.