cssi/SciSciGPT-SciSciNet huggingface dataset:
Simulation-Based Design of Orthopedic Trauma Implants

A computer-aided simulation model is developed to aid in the design and optimization of orthopaedic trauma implants. The developed model uses digital imaging, computer-aided solid modeling, and finite element methods in order to study the effects of various geometric parameters of fixation devices in orthopedic surgery practice. The results of the present simulation model would lead to the determination of the optimum implant design that provides the best match with the geometry of the human femur — reducing the risk of over-stressing bone tissue during implant insertion. The effectiveness of the presented simulation model is demonstrated through the design of intramedullary (IM) nails used in treating femoral shaft fractures. CT scans were taken of forty intact human femora. A technique was developed in order to digitally reconstruct the scans into 3D solid models using image segmentation, surface simplification, and smoothing methods while maintaining accurate representation of the original scans. Each resulting surface model is characterized by a network of nearly equilateral triangles of approximately the same size allowing for quality finite element meshing. Femoral lengths, curvature, shaft diameters, and location of maximum curvature were then quantified. An average geometric model was then generated for the investigated sample by averaging corresponding nodal coordinates in each femur model. Using the average model, a length-standardized function representing the curvature of the medullary canal was derived to create a geometrically optimized IM nail for the entire sample. “Virtual surgery” simulating the insertion process was then performed using finite element methods in order to validate the proposed optimal IM nail design. The results of both the optimum nail and a current nail were compared using the femur having the highest curvature in the sample. The present study shows that the developed simulation model leads to a nail design that reduces the insertion-induced stress within the femur to an acceptable level compared to current nails.Copyright © 2010 by ASME
Charmed-particle production by photon-gluon fusion

We apply a simple extension of the gluon-fusion model of Einhorn and Ellis to the photoproduction of charmed particles at high energies. Overall rates of production are not much different from those predicted by various current models for strong production of charm, leading to the belief that charm should be more easily seen in the photoproduction case where background are smaller. The predictions of the model for various energy and angle distributions are presented. Predicted rates depend strongly on the mass of the charmed quark.
The Stampede Toward Hofstede's Framework: Avoiding the Sample Design Pit in Cross-Cultural Research

We propose a method to design better multi-country samples for international business studies using Hofstede's framework and aimed at determining the effects of national culture on various business phenomena. We describe typical research scenarios, then develop sets of algorithms that calculate indexes reflecting the power of different samples for hypotheses testing. The indexes were computed from Hofstede's data, then rank ordered. The top multi-country samples are presented in tables for selection when designing studies.
The ion kinetic energy spectrum and the mass spectrum of argon

Abstract The technique of Ion Kinetic Energy Spectroscopy (I.K.E.S.) is described and results obtained with a sample of argon gas are discussed. When coupled with conventional mass spectroscopy, the technique enables the route to formation of the ions in the mass spectrum to be deduced. It can provide information on unimolecular or collision-induced decompositions of meta-stable ions. Its application to the study of the reactions of high-kinetic energy argon ions with nitrogen molecules is described.
Meroles revisited: complementary systematic inference from additional mitochondrial genes and complete taxon sampling of southern Africa's desert lizards.

The desert lizards (Meroles: Lacertidae) form a small clade of ground-dwelling taxa inhabiting arid southwest Africa (Arnold, 1991). All seven species have some portion of their range in the Namib Desert, and four of the seven are Namib endemics. Their close geographic ties to the Namib are hypothesized to reflect an interesting pattern of speciation, one in which the lineage infiltrated progressively extreme desert habitats through successive rounds of adaptation (Arnold, 1981, 1990, 1991). Ecological competition plays a key role in Arnold s (1981) speciation model, establishing a sequence of displacement, subsequent adaptation, and species formation. In this iterative process, the lineage s inchoate species came to occupy increasingly xeric environments, culminating in successful entry to aeolian dunes of the Namib s vast ‘‘sand seas.’’ A phylogenetic tree reflecting this iterative mode of speciation should yield a pectinate topology, and, indeed, Arnold (1991) generated just such a tree for Meroles, one fully resolved with little character conflict, in a parsimony analysis of morphological data. To test Arnold s phylogenetic estimate and address independently its progression of morphological adaptation, Harris et al. (1998) conducted a molecular phylogenetic analysis of the desert lizards, using sequence data from the mitochondrial 12S and 16S ribosomal genes. Their molecular phylogeny corroborated the monophyly of Meroles, with its inclusion of the formerly monotypic Aporosaura anchietae [transferred to Meroles by Arnold
A Method to Make a Craniotomy on the Ventral Skull of Neonate Rodents

The use of a craniotomy for in vivo experiments provides an opportunity to investigate the dynamics of diverse cellular processes in the mammalian brain in adulthood and during development. Although most in vivo approaches use a craniotomy to study brain regions located on the dorsal side, brainstem regions such as the pons, located on the ventral side remain relatively understudied. The main goal of this protocol is to facilitate access to ventral brainstem structures so that they can be studied in vivo using electrophysiological and imaging methods. This approach allows study of structural changes in long-range axons, patterns of electrical activity in single and ensembles of cells, and changes in blood brain barrier permeability in neonate animals. Although this protocol has been used mostly to study the auditory brainstem in neonate rats, it can easily be adapted for studies in other rodent species such as neonate mice, adult rodents and other brainstem regions.
Communication and Transition in the Middle East: A Critical Analysis of US Intervention and Academic Literature

US intervention in the Middle East builds on a problematic assumption that western technology and knowledge will transform the region into modern, democratic nation-states. The Arab Middle East in particular tends to be constructed in public discourse as suffering from social, political and economic hardships, in order to justify military action and development assistance. In this article, the author considers and critiques recent development intervention using communication technologies in terms of academic literature on communication and transition in the Middle East.
Physician hearing loss

Abstract Purpose Hearing is an important sense for physicians, making communication and stethoscope use possible, yet not much is known about the impact of hearing loss on professional function. The purpose of this study was to explore hearing-related issues affecting physicians. Materials and methods We administered a hearing test and questionnaire to 107 physicians and medical students. Results The proportion of physicians reporting trouble with their hearing increased with age, reaching almost 100% in those older than 60 years. Audiometric hearing loss also increased with age. Perceived hearing trouble was significantly associated with audiometric hearing loss, yet 46% of physicians with hearing loss described their hearing as good. Older physicians more frequently reported difficulty communicating with patients, staff, and colleagues owing to hearing problems ( P = .007). Reported stethoscope difficulties did not significantly increase with age; there was no association with hearing thresholds. No physician reported use of electronic stethoscopes or hearing aids. Noise exposures were common, yet 51% of respondents never used hearing protection. Younger physicians were less likely to use protection ( P = .002). Conclusion Physicians lose hearing with age but may not notice or report the loss. Physician hearing loss is associated with difficulty communicating with patients, staff, and colleagues. Neither age nor hearing level predicts problems with stethoscope use; possible explanations include a training effect or denial. Many physicians, especially younger ones, never use hearing protection around noise. Strategies to recognize and reduce the impact of hearing loss on professional function throughout a physician's career deserve greater attention.
Leadership preference, leadership behavior, and employee satisfaction

Abstract This study investigated five leadership dimensions and seven satisfaction criteria in two state highway department bureaus. One bureau dealt with Construction, the other was a bureau of Design. Each bureau differed in work demands and potential for supervisor-subordinate interaction. Data about leadership preference, leadership behavior, and satisfaction criteria were obtained statewide by mail questionnaires. Differences between the Construction and Design bureaus were predicted for: (1) leadership preference scores; (2) leadership behavior scores and their relationships with criteria; (3) leadership preference minus behavior discrepancy scores and their relationships with criteria; and (4) interactive leadership behavior X preference relationships with criteria. It was also predicted that the models in (3) and (4) above would have a stronger relationship with criteria than would leadership behavior alone. In general, a number of differences were found between the two bureaus concerning (1–4) above but the discrepancy and interactive models were not more strongly related to criteria than leadership behavior alone. Implications of these findings are discussed.
Generalized molecular descriptors

We review algebraic characterizations of molecular structures and in particular consider different matrices associated with a molecule as a source of novel graph invariants for use in structure-property and structure-activity studies. Such matrices can be classified as structure-explicit, structure-cryptic, and structure-implicit corresponding to a previous classification of molecular descriptors. In order to tame the proliferation of unwarranted topological indices, we propose requirements on indices and on the “source” matrices used for construction of molecular descriptors. Several structure-explicit and structure-implicit matrices are illustrated. A novel bond descriptorP′/P defined by the ratio of the number of paths in a graph G′, in which an edge is erased, and in the parent graphG′ is introduced. The derived bond-additive molecular P'/P index, which correlates well with the octane numbers in octanes, was found to be linearly related to the Wiener numbers.
A stochastic model for fluidized beds

Abstract A mathematical model for gas-fluidized beds is proposed that allows for a randomly fluctuating flow pattern. It is shown how mean first-order conversion is related to contact time distribution for arbitrary models of this type. A simplified version of the model is then studied, and it is found that the effect of fluctuating flow is similar to that of stagnancy in steady systems. This effect is inconsistent with the usual steady-state models, but it is shown that some published data on conversion in fluidized beds [6] exhibit this effect.
Tenotomy of the avian anterior latissimus dorsi muscle. I. Effect of age on fiber‐type transformation and regeneration from the stump in chicks

The chick's anterior latissimus dorsi muscle (ALD) was tenotomized at its origin at either 1 day or 4 weeks of age, and investigated histochemically and ultrastructurally at intervals thereafter to determine whether muscle fiber-type transformation from a slow to a twitch type is greater in young birds than older birds. No transformation of fiber type occurred in either procedure, but a new muscular connection regenerated between the scar tissue at the end of the original tenotomized stump and the former origin. This regenerated muscle had a mosaic pattern of fiber types, as demonstrated by myofibrillar ATPase activity, and contained predominantly fast fibers, as contrasted with controls or the tenotomized portion, which contained predominantly slow tonic muscle fibers. The regenerated portion contained muscle spindles. The original portion of the tenotomized muscle was indistinguishable from the control muscle. These responses of the chick ALD to tenotomy are quite different from those in the pigeon, which are reported in the following study.
Micrographia in Parkinson's disease.

Abstract Micrographia has been of interest to many neurologists; the phenomenon, however, remained unexplained. We have defined the incidence and characteristics of severe micrographia in a large population of Parkinsonian patients. It is totally separable from tremor and rigidity in these patients and has only an indefinite relationship to akinesia. In about 5% of all Parkinsonian patients, micrographia is present as a prodromal symptom before any other manifestation of the disease is noted; this is true in 30% of those patients who will later develop severe micrographia during the course of their disease. It remains essentially uninfluenced by various forms of treatment of Parkinsonism including stereotaxic thalamotomy; however, during treatment with levodopa some cases of micrographia improve. We feel that micrographia is of central origin, and evidence is offered in support of this hypothesis. A more complete understanding of the mechanism of micrographia would add much to our understanding of some subtleties of extrapyramidal motor dysfunction.
Trade vote determinants: Partisan effects of political action committee contribution percentages

Abstract Free trade agreements are less likely than other major congressional roll call votes to be decided by party affiliation, and are therefore regarded as opportunities to test the impact of interest group influence in the observable form of campaign donations. In this project, the vote to normalize trade relations with China is analyzed by variables including the percentage of total campaign donations from either labor or business. The data indicate that higher percentages of labor contributions, or relative interest group support, raised the probability that a member would vote against the trade bill, and the effect appeared more pronounced among Republicans than Democrats.
Exploring the importance of the relative solubility of matrix and analyte in MALDI sample preparation using HPLC.

New insight into the role of solubility in the sample preparation process for MALDI MS is reported. Reversed-phase gradient HPLC conditions were developed that enable the analysis of a broad range of analyte polarities with a single method. This HPLC method was used to establish a relative polarity scale for a series of 15 MALDI matrix materials, a set of example peptides, and a series of model polymer materials with a broad range of polarity. Examples of each polymer type within the range of 6000−10 000 were analyzed with six matrixes that cover a broad range of polarity using MALDI TOFMS. With regard to polymer signal-to-noise ratio, the matrix and polymer combinations that had a close match of HPLC retention time produced the best MALDI spectra. Conversely, the matrix and polymer combinations that have a large difference in HPLC retention time produced poor MALDI spectra. The results suggest that there is a relationship between polarity (solubility) and effective MALDI sample preparation. The relative ...
GPU acceleration of Data Assembly in Finite Element Methods and its energy implications

The Finite Element Method (FEM) is a numerical technique widely used in finding approximate solutions for many scientific and engineering problems. The Data Assembly (DA) stage in FEM can take up to 50% of the total FEM execution time. Accelerating DA with Graphics Processing Units (GPUs) presents challenges due to DA's mixed compute-intensive and memory-intensive workloads. This paper uses a representative finite element mini-application to explore DA acceleration on CPU+GPU platforms. Implementations based on different thread, kernel and task design approaches are developed and compared. Their performance and energy consumption are measured on four CPU+GPU and two CPU only platforms. The results show that (i) the performance and energy for different implementations on the same platform can vary significantly but the performance and energy trends are the same, and (ii) there exist performance and energy tradeoffs across some platforms if the best implementation is chosen for each of the platforms.
Mr assessment of the extremity veins

This article provides an overview of the technique of magnetic resonance venography (MRV) and its relative value in the diagnostic work-up of suspected lower or upper extremity venous thrombosis. MRV is accurate for diagnosis or exclusion of deep vein thrombosis. MRV should be considered complimentary, in many instances, to the less expensive modality of venous sonography. It is the complimentary use of magnetic resonance techniques at the level of the pelvis and the mediastinum that offers the greatest cost benefit as part of an incremental strategy for the work-up of patients presenting with lower or upper extremity swelling.
The Role of Gender in Heart Transplantation

Abstract Background . The effect of donor and recipient gender on the outcome of heart transplantation (HT) remains uncertain. Methods . One hundred seventy-four patients who underwent HT were divided into four groups according to donor and recipient gender. Group A consisted of 81 men who received male donor hearts, group B of 18 women who received female donor hearts, group C of 21 women who received male donor hearts, and group D of 54 men who received female donor hearts. All patients were treated by the same group of surgeons according to standard HT protocols. Comparisons were made between groups with regard to short- and long-term outcomes. Results . Donor gender and recipient gender did not affect outcomes significantly. Overall, donor-recipient gender mismatching significantly increased the number of rejection episodes and reduced creatinine clearance, survival, and censored survival in the first year after HT ( p p p Conclusions . Donor-recipient gender matching plays a significant role in determining HT outcomes.
Crossing Cultures in Marriage: Implications for Counseling African American/African Couples.

A wealth of literature exists regarding intermarriage between White and ethnic minority couples. Noticeably lacking, however, is information considering within-group diversity amongst Black couples. This paper will focus on cultural dynamics that may operate with African American and African couples residing in the United States. Through an examination of within-group differences and similarities, counselors can be better prepared to assist such couples in addressing and negotiating possible cross-cultural challenges. A case study example will be considered with critical incidents discussed and essential cross-cultural counseling competencies will be addressed.
Crash behavior of a 3D S-shape space frame structure

Abstract In order to ensure enough passenger space and reduce the damage of occupants during a car front collision, it is necessary to understand the crushing behavior and to improve the energy absorption capability of space frame structures. In this study, the crushing behavior of a 3D S-shape extruded aluminum square frame with 45° curvature angle (α) and 45° rotation angle (β) is studied under an axial loading. Different cross-section reinforcements (parallel and diagonal internal lateral support profiles) and aluminum foam-filled reinforcement are discussed. The effectiveness of reinforcement is assessed using the specific energy absorption and the peak force. Based on the numerical analyses, the left diagonal reinforced structure shows the highest specific energy absorption (SEA = 3.813 J/g). This is 277% of the SEA of the empty column structure (SEA = 1.375 J/g). In addition, the aluminum foam-filled reinforcement increases the energy absorbed by the 3D space frame structure by an additional 78%. The results show that aluminum foam is an efficient alternative energy absorber. However, it does not increase the SEA of the structure due to the increased mass and increases the peak force significantly.
Clonidine reduces plasma melatonin levels.

Clonidine, an α-adrenoceptor agonist, reduces human plasma melatonin levels when administered intravenously at 2–3 (μg kg−1 to sleeping volunteers. Measurement of plasma melatonin levels after administration of clonidine could be the basis for a clinical in-vivo test of α-adrenoceptors.
Root distribution of lettuce under commercial production: implications for crop uptake of nitrogen

ABSTRACT Crop root distribution is important for management of soil fertility and for development of practice that minimize leaching of nitrate (NO3 −-N) below the root zone. Objectives of this study were to describe lettuce (Lactuca sativa L.) rooting patterns under actual management practices in growers' fields and to relate rooting patterns to soil NO3 −-N distribution in lettuce production systems. Three conventional farms (Farms 1, 2 and 3) and one organic farm (Farm 4) were evaluated: 1) a direct-seeded crisphead lettuce field which was sprinkler irrigated until thinning and later furrow irrigated; 2) a similarly managed site planted with both direct-seeded and transplanted crisphead lettuce; 3) a direct-seeded crisphead lettuce field under subsurface drip irrigation; and 4) a high-density planting of leaf lettuce grown under surface drip irrigation. The ‘Salinas’ or a closely-related crisphead cultivar was planted at the first three sites and leaf lettuce was grown at the organic farm. Root charact...
Simulation of the conformation of the murein fabric: the oligoglycan, penta-muropeptide, and cross-linked nona-muropeptide

The structure and conformation of the sacculus of bacteria at a scale much larger than just the component disaccharide penta-muropeptide is not well known and is crucially important for the understanding of bacterial growth and cell wall function. By computer simulations, the minimal energy conformations and the energy needed for stretching the component parts were found. The oligosaccharide chain, modeled as (GlcNAc-MurNAc)8 when under no tension, can assumed a variety of nearly iso-energetic conformations. These included a variety of bends and kinks, with the chain forming an irregular random coil. In the most relaxed and minimal energy state, the D-lactyl groups of the MurNAc (N-acetyl muramic acid) residues protruded at about an angle of 90° relative to the D-lactyl groups of their immediate MurNAc neighbors in the same chain. The cell wall penta-muropeptide precursor is identical for Escherichia coli and Bacillus subtilis; it also adopted many conformations, each of an energy almost equal to the global minimum. The cross-bridged structure of the tail-to-tail linkage of disaccharide nona-muropeptide has a second type of association, in addition to the covalent cross-bridge, which has not been considered before. This is the ionic interaction between the free D-Ala and the free amino group of the m-A2 pm. In vivo, when the cross-bridge is stretched (in the computer to simulate growth), this pairing dissociates. The possible biological significance of this is that it exposes the underlying 'tail-to-tail' peptide bond to autolysis and will expose both the ends of the m-A2 pm and the D-Ala-D-Ala groups that may then be able to react with nascent penta-muropeptides to form trimers. This suggests a new model for growth of the bacterial cell wall that depends on changes in the chemical conformation of the cross-bridge structure as it comes to bear stress.
Predicting Death in Pediatric Patients With Acute Respiratory Failure

Objective To estimate mortality risk in pediatric patients with acute hypoxemic respiratory failure (AHRF). Design Retrospective chart review. Setting Forty-one pediatric ICUs. Subjects Four hundred seventy children with AHRF. We defined AHRF as mechanical ventilation with positive end-expiratory pressure ≥6 cm H 2 O and fraction of inspired oxygen greater than or equal to 0.5 for 12 or more hours. Measurements Physiologic and treatment variables were recorded every 12 h for 14 days. Cases were randomly assigned to score development and score validation subsets. Variables were assessed for their association with mortality in the development subset by logistic regression analysis. The analysis generated a series of logistic equations, which we called the Pediatric Respiratory Failure (PeRF) score, to estimate mortality risk at 12-h intervals over the first 7 days of treatment for AHRF. The predictive ability of the score was assessed in the validation subset by receiver operating characteristic curve area and goodness-of-fit χ 2 . Results Mortality of the collected cases was 43%. The PeRF score included age, operative status, Pediatric Risk of Mortality score, fraction of inspired oxygen, respiratory rate, peak inspiratory pressure, positive end-expiratory pressure, PaO 2 , and PaCO 2 . Area under the receiver operating characteristic curve was 0.769 at entry and increased to greater than 0.8 after 36 h. When the score was applied to the validation subset of patients, goodness-of-fit χ 2 showed no significant difference between estimated and actual mortality between 0 and 96 h. Conclusions The PeRF Score accurately estimated mortality risk in this retrospectively sampled group of high-risk pediatric patients with AHRF. This score may be useful in studies of newer therapies for pediatric AHRF, though prospective validation is necessary before it could be used to make clinical decisions.
Robust Classification of “Relevant” Water Molecules in Putative Protein Binding Sites

A statistically validated protocol to identify “relevant” water molecules in protein binding sites using HINT score and a geometric descriptor termed Rank is described. In training, conservation/nonconservation was modeled for 86% of the waters. For the test set, 87% of waters were correctly classified (92% when crystallographic resolution was ≤2.0 A). Conserved waters make at least two hydrogen bonds with protein and gain 0.6−2.0 kcal mol−1 more binding energy than nonconserved waters.
When does time perspective matter? Self-control as a moderator between time perspective and academic achievement

This study examined how individual differences in self-control moderated the relationship between time perspective and academic achievement, consistent with self-regulatory theory. The results, based on 255 participants, revealed that college students with a future time perspective reported higher GPAs, while students with a present time perspective had lower GPAs, even when controlling for differences in demographic variables. However, in support of the moderation hypothesis, these relationships were only present in low self-control students. For students who reported higher perceptions of self-control, the only significant predictors of GPA were ACT scores, race, and sex. These results were interpreted as providing empirical support for the importance of self-control as a mechanism that influences the link between dispositions and behavioral outcomes.
Quantifying Local Microcrack Density in Ceramics: A Comparison of Instrumented Indentation and Thermal Wave Techniques

Instrumented indentation and thermal wave techniques are used as local, quantitative probes of microcrack density in a silicon nitride that has been subjected to severe Hertzian contact stress. The techniques act as local probes, sampling volumes of material <10{sup {minus}3} mm{sup 3}. Microcracked regions are created using a tungsten carbide spherical indenter, as a result of high shear stress in the compressive zone beneath the indenter. The microcracked zones, studied in cross section using a ``bonded interface`` technique, increased both in size and in degree of damage with increasing Hertzian load. Within the zones, Young`s modulus is measured using instrumented indentation, and the thermal diffusivity using a thermal wave technique; both quantities are lower in the damaged regions than in the undamaged regions. The shifts in modulus and diffusivity are used independently to calculate microcrack densities using related models of the effect of microcracks on each property. The two techniques show the same functional relationship between Hertzian contact load and microcrack density, and yield densities that agree to within a factor of approximately 2.
The Effect of Surface Nano/Micro-Texturing on Escherichia Coli Cell Adhesion

Control of cell-to-surface adhesion has significant impacts on various biological and biomedical applications. In this study, the adhesion of Escherichia coli (E. coli) cells on nano/micro-textured surfaces produced by a unique surface texturing technique, aluminum-induced crystallization (AIC) of amorphous silicon (a-Si), was studied in order to control E. coli cell adhesion on glass substrates in an E. coli-based whole-cell chemical sensor. It was found that textured surfaces significantly enhanced cell-to-surface adhesion. Among the textured surfaces, nano/micro-textured surfaces showed advantage over micro-textured surfaces on the cell-to-surface adhesion. Study of the cell-to-surface adhesion mechanism suggests that the cell adhesion efficiency was controlled by the particle density of the textured surfaces.Copyright © 2008 by ASME
A gas chromatographic method for the assessment of used frying oils: Comparison with other methods

The application of a simple and rapid method, based on gas chromatographic measurement of dimer triglycerides, is proposed for evaluation of the quality of used frying oils. The technique involves complete conversion of the oil to its methyl esters followed by analysis on a short column packed with 3% JXR. Parameters are adjusted to provide a pattern in which the dimeric esters emerge as a doublet peak with a retention time of ca. 3 min, whereas all other monomeric esters elute with the solvent peak. The relative heights of the two components of the doublet peak appear to reverse as the frying time is increased. The test correlated well with changes in dielectric constant measurements, as well as with “altered triglycerides” in continuously heated corn oil.
On the 2-extendability of the generalized Petersen graphs

Abstract A graph G is n -extendable if it is connected, contains a set of n independent edges and every set of n independent edges extends to (i.e. is a subset of) a perfect matching. Combining the results of this and previous papers we answer the question of 2-extendability for all the generalized Petersen graphs G ( n , k ) with k ⩽7 as well as for all G ( n , k ) with n ⩾3 k + 5.
A fuzzy logic intelligent control system paradigm for an in-line-of-sight leader-following HMMWV

A hierarchical intelligent control system paradigm for a vision-based autonomous driving scheme is presented for a leader-following HMMWV. This article shows how fuzzy logic is employed to represent knowledge at the organization level, how to resolve conflicting perceived information at the coordination level, and how to carry out the best action for the vehicle at the execution level. After introducing the methodology, simulation and experimental aspects for realizing and testing the scheme are discussed. ©1997 by John Wiley & Sons, Inc.
The optometric correlates of migraine

Migraine is a common, chronic, multi-factorial, neuro-vascular disorder typically characterised by recurrent attacks of unilateral, pulsating headache and autonomic nervous system dysfunction. Migraine may additionally be associated with aura; those focal neurological symptoms that may precede or sometimes accompany the headache. This review describes the optometric aspects of migraine headache. There have been claims of a relationship between migraine headaches and errors of refraction, binocular vision anomalies, pupil anomalies, visual field changes and pattern glare. The quality of the evidence for a relationship between errors of refraction and binocular vision and migraine is poor. The quality of the evidence to suggest a relationship between migraine headache and pupil anomalies, visual field defects and pattern glare is stronger. In particular the link between migraine headache and pattern glare is striking. The therapeutic use of precision-tinted spectacles to reduce pattern glare (visual stress) and to help some migraine sufferers is described.
The Relationship Between Perceptions of Response to Disclosure of Childhood Sexual Abuse and Later Outcomes

This study assessed whether perceptions of others' reactions to disclosure are related to psychological and physical outcomes among individuals with a history of child sexual abuse. Eighty-six female undergraduates completed a series of questionnaires assessing child sexual abuse, nonsexual trauma, depression, anxiety, posttraumatic stress disorder, somatic symptoms, disclosure, and social reactions to disclosure. Those who reported child sexual abuse endorsed higher levels of psychological and physical symptoms than those who reported a nonsexual traumatic event. Child sexual abuse survivors who reported more hurtful responses to disclosure had higher levels of posttraumatic stress disorder, anxiety, and physical symptoms than nonsexual trauma survivors. These findings suggest that many survivors of CSA may need psychological services, and an important focus of treatment may be assessing and strengthening social support.
Collaboration theory and tourism practice in protected areas: stakeholders, structuring and sustainability

A growing body of research is emerging on tourism and partnerships in protected areas, but conceptual development remains fragmented. This paper tackles this challenge by focusing on three aspects important for sustainability: (1) complexity (nested systems of biophysical environments, tourism and park management structures, community–resident systems, local–global systems and use–conservation gap; (2) scale, structure and scope of collaborations (including community involvement and control) and (3) challenges of implementation and long term structuring (for sustainability and success). Some related questions are: How does the tourism system fit with the protected area system? Who represents “Nature” in negotiations over conservation and use? How can plans and programmes be effectively enacted at the local level for long term success? A theoretical discussion plus an example of community-based collaboration for conservation and economic development in Bolivia (Chalalan Ecolodge) are provided to explore th...
POLITICAL SOCIALIZATION AND POLITICAL ROLES

This study challenges the theory that adult political behavior is little more than an elaboration of patterns rooted in childhood. It is based on evidence from 421 state legislators in 4 states and 129 city councilmen from 23 cities. Comparing and contrasting those who entered politics early and late, the authors conclude that political experiences in childhood and adolescence are less important than more relevant and pressing demands in orienting officeholders to their jobs. Kenneth Prewitt is Assistant Professor of Political Science at the University of Chicago, Heinz Eulau is Professor of Political Science at Stanford University, and Betty H. Zisk is Assistant Professor of Political Science at Boston University.
Relationships between welfare status, health insurance status, and health and medical care among children with asthma.

Objectives. This study evaluated the relationships between health insurance and welfare status and the health and medical care of children with asthma. Methods. Parents of children with asthma aged 2 to 12 years were interviewed at 6 urban clinical sites and 2 welfare offices. Results. Children whose families had applied for but were denied welfare had more asthma symptoms than did children whose families had had no contact with the welfare system. Poorer mental health in parents was associated with more asthma symptoms and higher rates of health care use in their children. Parents of uninsured and transiently insured children identified more barriers to health care than did parents whose children were insured. Conclusions. Children whose families have applied for welfare and children who are uninsured are at high risk medically and may require additional services to improve health outcomes.
Improved and Rapid High-Performance Liquid Chromatographic Assay for 13-cis- Retinoic Acid or All-trans-retinoic Acid

Abstract A rapid, specific, and sensitive reversed-phase high-performance liquid chromatographic (HPLC) assay for the quantitative determination of all - trans - retinoic acid (I) or 13- cis -retinoic acid (II) in rat serum without extraction or lyophilization is described. Chromatographic separation from retinol, serum components, and retinol acetate standard was achieved on octadecylsilane-coated particles with aceto-nitrile-1% ammonium acetate as the eluent. Serum samples (100 μ l) containing as little as 10 ng of retinoid were analyzed. Serum level profiles of rats dosed with the retinoids demonstrated the utility of the assay and indicated elimination half-lives of 0.58 and 0.92 hr for I and II, respectively.
STATUS AND DISTRIBUTION OF THE ENDANGERED BENTON CAVE CRAYFISH, CAMBARUS ACULABRUM (DECAPODA: CAMBARIDAE)

Abstract We present the first summary of the status and distribution of the Benton cave crayfish (Cambarus aculabrum). The range of this endangered crayfish is limited to 4 sites globally (3 in Benton County and 1 in Washington County, Arkansas). The identity of the species at these 4 sites is based upon morphological and genetic studies. The identities of cave crayfish inhabiting 2 additional Benton County sites remain undetermined. The current population census is 40 individuals. Threats to the species are analyzed, and subsequent conservation measures recommended. Habitat degradation remains a threat to the species, especially for water quality. Analyses from 1983 to 2002 document nutrient pollution of the subterranean stream habitats, originating from sources such as septic system discharge and run-off from confined animal feeding operations.
Regulation of subcellular localization of the Aryl Hydrocarbon Receptor (AhR)

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the toxicity of dioxin and other xenobiotics. In the absence of exogenous ligand, AhR is cytosolic. We investigated how AhR is retained in the cytosol and how dioxin induces AhR to move to the nucleus. Disruption of nuclear export of AhR by the nuclear export inhibitor leptomycin B (LMB) or by mutation of the AhR nuclear export signal resulted in nuclear accumulation of AhR in the absence of exogenous ligand. Mutation of the AhR nuclear localization signal resulted in defects in nuclear import of AhR in both the presence and the absence of exogenous ligand. Dioxin treatment caused a more rapid accumulation of AhR in the nucleus than LMB treatment. In the presence of both dioxin and LMB, nuclear accumulation of AhR was more rapid than in the presence of dioxin alone. Our results show that AhR shuttles between the nucleus and the cytosol in the absence of exogenous ligand. Binding of ligand induces an increase in the rate of nuclear import of AhR but does not eliminate nuclear export of AhR.
The role of the divalent cation in the structure of the I domain from the CD11a/CD18 integrin.

Background: The integrin family of cell-surface receptors mediates a wide variety of cell‐cell and cell‐extracellular matrix interactions. Integrin‐ligand interactions are invariably dependent on the presence of divalent cations, and a subset of integrins contain a ~200 amino acid inserted (I) domain that is important for ligand binding activity and contains a single divalent cation binding site. Many integrins are believed to respond to stimuli by undergoing a conformational change that increases their affinity for ligand, and there is a clear difference between two crystal structures of the CD11b I domain with different divalent cations (magnesium and manganese) bound. In addition to the different bound cation, a ‘ligand mimetic’ crystal lattice interaction in the CD11b I domain structure with bound magnesium has led to the interpretation that the different CD11b I domain structures represent different affinity states of I domains. The influence of the bound cation on I domain structure and function remains incompletely understood, however. The crystal structure of the CD11a I domain bound to manganese is known. We therefore set out to determine whether this structure changes when the metal ion is altered or removed. Results: We report here the crystal structures of the CD11a I domain determined in the absence of bound metal ion and with bound magnesium ion. No major structural rearrangements are observed in the metal-binding site of the CD11a I domain in the absence or presence of bound manganese ion. The structures of the CD11a I domain with magnesium or manganese bound are extremely similar. Conclusions: The conformation of the CD11a I domain is not altered by changes in metal ion binding. The cation-dependence of ligand binding thus indicates that the metal ion is either involved in direct interaction with ligand or required to promote a favorable quaternary arrangement of the integrin.
Convergent Snapshot Algorithms for Infinite-Dimensional Lyapunov Equations

We consider two algorithms to approximate the solution Z of a class of stable operator Lyapunov equations of the form AZ + ZA∗ + BB∗ = 0. The algorithms utilize time snapshots of solutions of certain linear infinite dimensional differential equations to construct the approximations. Matrix approximations of the operators A and B are not required and the algorithms are applicable as long as the rank of B is relatively small. The first algorithm produces an optimal low rank approximate solution using proper orthogonal decomposition. The second algorithm approximates the product of the solution with a few vectors and can be implemented with a minimal amount of storage. Both algorithms are known for the matrix case, however the extension of the algorithms to infinite dimensions appears to be new. We establish easily verifiable convergence theory and a priori error bounds for both algorithms and present numerical results for two model problems.
A novel, tapered, both in dimension and in index, velocity coupler switch

A digital optical switch using a velocity coupler tapered both in dimension and in index, which shows the smallest voltage-length product reported so far for digital optical switches, is presented. Numerical results for the graded-index channel waveguide coupler, which can be applied to all z-variant structures with 2D graded-index profile, are presented. >
Integrated plasmonic systems for ultrasensitive spectroscopy and biodetection

Plasmonics, by localizing light to the sub-wavelength volumes and dramatically enhancing local fields, is enabling myriad of exciting opportunities for construction of novel photonic devices and integrated nanophotonic systems. In this talk, I will present our recent work on integrated on-chip plasmonics, nanofluidics, and metamaterials and their applications in ultrasensitive spectroscopy and biodetection.
Tectonic Control of Late Paleozoic and Early Mesozoic Sedimentation Near Hinge Line of Cordilleran Miogeocline: ABSTRACT

Pennsylvanian, Permian, and Lower Triassic strata in the eastern Great Basin aggregate about 35,000 ft of dominantly marine clastic and carbonate rocks that accumulated in the eastern part of the Cordilleran miogeocline. Subsidence and hypersubsidence created the Sublett, Oquirrh, Arcturus, Park City, Bird Springs, and other sedimentary basins within this major downwarp of the earth's crust. Late Paleozoic and early Mesozoic tectonism within and adjacent to the miogeocline controlled contrasting realms of clastic and carbonate sedimentation. Highlands in western and northwestern Utah, in eastern and northeastern Nevada, and in southern Nevada, certain orogenic belts (e.g., Sonoma) were stripped, in places to their Precambrian cores, and provided abnormal thicknesses of se iment to adjacent mobile negative depocenters. The craton east of the tectonic hinge line provided additional sediment. The Cordilleran miogeocline did not close its doors in chaotic orogenic spasms at the end of the Paleozoic. Contrarily, the changeover from Permian to Early Triassic was not a major diastrophic event. A paraconformity typifies the boundary at many places, with disconformities elsewhere. Up to 4,000 ft of Early Triassic sediments accumulated; by Middle Triassic time, a major reversal occurred: what had been a major negative mobile belt since late Precambrian time was now uplifted, although the region east of the hinge line became negative, and the hinge line was a fulcrum. The Cordilleran miogeocline was destroyed, and some of its sediments were stripped away, only to be recycled and deposited in the Rocky Mountain geosyncline on the east. End_of_Article - Last_Page 770------------
Design considerations for air cooling electronic systems in high altitude conditions

Covers the impact of altitude on electronics cooling. MIL-STD 210 is reviewed to demonstrate the relationship of altitude to density as well as to outside air temperature. Once these relationships are understood the paper discusses the impact of altitude on the performance of air moving devices using the widely accepted fan laws. A discussion of both constant speed and altitude compensating fans addresses performance issues such as power dissipation, pressure drop, and free delivery of fans under these conditions. Once the fan performance has been characterized, the system impedance (or pressure drop) must be determined for the appropriate altitude. The paper covers how system impedance changes under laminar and turbulent flow regimes as altitude varies. This is most important since poor thermal designs have resulted when the flow regime was not known. Since every altitude has a unique system impedance, a modified system impedance curve, called the Sigma-Delta P curve, is presented. This collapses all of the altitude curves to one curve and is a powerful way to characterize a system for all altitudes. The impact of altitude on heat transfer is also discussed along with the effects of operating in the turbulent and laminar regimes. In order to demonstrate the concepts, an example problem is worked.