cssi/SciSciGPT-SciSciNet huggingface dataset:
An Effective Version of Belyi's Theorem☆

Abstract We compute bounds on covering maps that arise in Belyi's Theorem. In particular, we construct a library of height properties and then apply it to algorithms that produce Belyi maps. Such maps are used to give coverings from algebraic curves to the projective line ramified over at most three points. The computations here give upper bounds on the degree and coefficients of polynomials and rational functions over the rationals that send a given set of algebraic numbers to the set {0,1,∞} with the additional property that the only critical values are also contained in {0,1,∞}.
Beyond the implantable cardioverter-defibrillator: are we making progress?

Sudden cardiac death due to ventricular fibrillation occurs when a dynamic interaction between triggers and substrate leads to the development of reentry, initiation of ventricular tachycardia, and its degeneration to fibrillation. To move beyond the implantable cardioverter-defibrillator as the only effective therapy for aborting sudden cardiac death, an improved understanding of trigger–substrate interaction is essential. This brief review summarizes some of the recent progress in this direction.
Design and Fabrication of a High-Temperature Helium Regenerator.

Abstract Refractory metallic foams can increase heat transfer efficiency in gas-to-gas and liquid metal-to-gas heat exchangers by providing an extended surface area for better convection, i.e. conduction into the foam ligaments providing a “fin-effect,” and by disruption of the thermal boundary layer near the hot wall and ligaments by turbulence promotion. In this article, we describe the design of a high-temperature refractory regenerator (closed-loop recuperator) using computational fluid dynamics (CFD) modeling of actual foam geometries obtained through computerized micro-tomography. The article outlines the design procedure from geometry import through meshing and thermo-mechanical analysis and discusses the challenges of fabrication using pure molybdenum and TZM. The foam core regenerator is more easily fabricated, less expensive and performs better than refractory flat plate-type heat exchangers. The regenerator can operate with a maximum hot leg inlet temperature of 900 °C and transfer 180 kW to the cold leg using 100 g/s helium at 4 MPa. Future high heat flux experiments on helium-cooled plasma facing components will utilize the high temperature and high pressure capabilities of this unique regenerator. Similar components will be required to adapt fusion power reactors to high-efficiency Brayton power conversion systems and enable operation of advanced divertor and blanket systems.
Images of Fictional Community College Students

Popular media represent outlets for shaping and informing public perception of institutions and institutional actors found in our society. Community colleges and their students have been featured in a number of fictional works. This paper provides an analysis of the portrayal of community college students in the fictional works of novels, short stories, television programs, and motion pictures. Through this analysis, the authors highlight significant lessons that can be learned from increased understanding of fictional portrayals of community colleges and their students and applied to both community college practice and continued research.
Implementation of a robust transmission system for astronomical images over error-prone links

The James Webb Space Telescope (JWST) is expected to produce a vast amount of images that are valuable for astronomical research and education. To support research activities related to the mission, the National Aeronautical and Space Administration (NASA) has provided funds to establish the Structures Pointing and Control Engineering (SPACE) Laboratory at the California State University, Los Angeles (CSULA). One of the research activities in SPACE lab is to design and implement an effective and efficient transmission system to disseminate JWST images across networks. In on our previous research, a prioritized transmission method was proposed to provide the best quality of the transferred image based on the joint-optimization of content-based retransmission and error concealment. In this paper, the design and implementation of a robust transmission system is presented to utilize our previously proposed methods over error-prone links. The implemented system includes three parts. First, a zero-tree based error-resilient wavelet codec is used to compress the incoming astronomical image at the sender. Tree-based interleaving is adopted in packetization to increase the system's capability to combat burst losses in error-prone channels. Second, various error concealment approaches are investigated and implemented at the receiver to improve the quality of the reconstructed image. The transmission system uses UDP as the transport protocol, but with an error control module to incorporate the optimal retransmission with the delay constraint. A user-friendly graphical interface is designed to allow easy usage for users of diverse backgrounds.
Fracture Toughness of Fused SiO2 and Float Glass at Elevated Temperatures

The fracture toughnesses of fused SiO2 and float glass were measured at high temperatures. In both glasses, low-temperature regions of elastic fracture were identified and correlated with the elastic moduli and their temperature dependence. A viscous flow contribution to the fracture toughness was identified in the fused SiO2 at T>800°C. Similar indications of viscous flow were also noted in the float glass, although at much lower temperatures.
Comments on the reduction of large-N chiral models

The construction of reduced chiral models via dimensional reduction of gauge theories is critically reanalyzed, the question of spontaneous symmetry breaking is reexamined, and further numerical results are presented.
Statistical designation of traffic control subareas

A method for identifying control subareas in traffic signal networks has been developed and tested with data from the Miami, Florida, business district. The procedure combines the use of cluster and discriminant analysis to group signalized intersections. Unlike existing procedures which use degrees of association between adjacent signals, the multivariate procedures used in this method allow for consideration of degrees of association among all signals in the original network. Model tests used the flow ratio for each intersection approach as the vector of intersection attributes. The resulting subareas were compact, well defined and slightly different for morning and midday traffic conditions. The procedure appears to have considerable utility in defining control subgroups in signal system design.
Ganglioside and morphological changes in mouse embryo cells with time.

Summary Ganglioside and morphological changes were observed in C3H/10T1/2CL8 cells during a 4-year period of maintenance in the laboratory. The cellular morphology at confluency, as determined by scanning electron microscopy, changed from being polygonal and flattened to a fusiform shape with some piling up of cells. The saturation density increased about three-fold and the level of the simplest ganglioside GM 3 ( N -acetylneuraminylgalactosylglucosylceramide) increased about two-fold. While the reasons for the alterations are unknown, the data suggest a relationship among ganglioside composition, cellular morphology and regulation of cell growth. The possible implications of such biochemical and biological changes on studies comparing normal and transformed cells are discussed.
The in vivo neuron-to-astrocyte lactate shuttle in human brain: evidence from modeling of measured lactate levels during visual stimulation

Functional magnetic resonance spectroscopy (fMRS) allows the non-invasive measurement of metabolite concentrations in the human brain, including changes induced by variations in neurotransmission activity. However, the limited spatial and temporal resolution of fMRS does not allow specific measurements of metabolites in different cell types. Thus, the analysis of fMRS data in the context of compartmentalized metabolism requires the formulation and application of mathematical models. In the present study we utilized the mathematical model introduced by Simpson et al. (2007) to gain insights into compartmentalized metabolism in vivo from the fMRS data obtained in humans at ultra high magnetic field by Mangia et al. (2007a). This model simulates brain glucose and lactate levels in a theoretical cortical slice. Using experimentally determined concentrations and catalytic activities for the respective transporter proteins, we calculate inflow and export of glucose and lactate in endothelium, astrocytes, and neurons. We then vary neuronal and astrocytic glucose and lactate utilization capacities until close correspondence is observed between in vivo and simulated glucose and lactate levels. The results of the simulations indicate that, when literature values of glucose transport capacity are utilized, the fMRS data are consistent with export of lactate by neurons and import of lactate by astrocytes, a mechanism that can be referred to as a neuron-to-astrocyte lactate shuttle. A shuttle of lactate from astrocytes to neurons could be simulated, but this required the astrocytic glucose transport capacity to be increased by 12-fold, and required that neurons not respond to activation with increased glycolysis, two conditions that are not supported by current literature.
Role of brachytherapy in the management of the skull base meningioma. Treatment of skull base meningiomas.

Background. The treatment of primary and recurrent skull base meningiomas presents a formidable surgical problem. Methods. Fifteen patients with primary and recurrent skull base meningiomas were treated by means of interstitial irradiation with iodine 125 ( 125 I) seed implantation. The physical characteristics of 125 I enabled the authors to administer a minimum tumor dose ranging from 100 to 500 Gy at a low dose rate of 0.05-0.25 Gy per hour. Results. All 15 patients are alive at a median followup of 29 months. Of the 15 patients, 2 with calcification and 2 without calcification achieved only partial responses. The remaining 11 patients achieved a complete response. No early or late complications were observed
Graphical representation of Timoshenko beam modes for clamped–clamped boundary conditions at high frequency: Beyond transverse deflection

Abstract Transverse deflection and bending-slope mode shapes for a clamped–clamped Timoshenko beam are presented in combined form and compared with finite element (FE) results. The linkage between the cut-on frequency for multiple phase velocities, and noteworthy change in the character of the mode shapes predicted by Timoshenko beam theory (TBT), observed in recent paper by van Rensburg and van der Merwe, is illustrated. While previous work in bounded systems has employed comparisons of TBT and FE obtained resonance frequencies to demonstrate the limits of validity of TBT, direct comparison of the mode shapes predicted by TBT and FE provides an alternative means of comparison, and unambiguously indicates TBT is not valid above the cut-on frequency for the case considered. Typographical errors in Huang’s analysis are also noted.
Acute paraparesis secondary to Arnold‐Chiari type I malformation and neck hyperflexion

A 2-year-old child experienced clinical manifestations of Arnold-Chiari Type I malformation, rare in early childhood, after a mild hyperflexion injury of the neck that resulted in acute paraparesis. Recovery occurred after decompressive laminectomy.
Buncher for a Microwave Linear Electron Accelerator

This paper reports on design and construction features of a bunching system built at the Naval Research Laboratory (NRL) for the NRL linac, with emphasis on solution of the impedance matching and tuning problems inherent in the buncher design.
The Probability of Small Schedule Values and Preference for Random-Interval Schedules

Preference for working on variable schedules and temporal discrimination were simultaneously examined in two experiments using a discrete-trial, concurrent-chains arrangement with fixed interval (FI) and random interval (RI) terminal links. The random schedule was generated by first sampling a probability distribution after the programmed delay to reinforcement on the FI schedule had elapsed, and thus the RI never produced a component schedule value shorter than the FI and maintained a rate of reinforcement half that of the FI. Despite these features, the FI was not strongly preferred. The probability of obtaining the smallest programmed delay to reinforcement on the RI schedule was manipulated in Experiment 1, and the interaction of this probability and initial link length was examined in Experiment 2. As the probability of obtaining small values in the RI increased, preference for the schedule increased while the discriminated time of reinforcer availability in the terminal link decreased. Both of these effects were attenuated by lengthening the initial links. The results support the view that in addition to the delay to reinforcement, the probability of obtaining a short delay is an important choice-affecting variable that likely contributes to the robust preferences for variable, as opposed to fixed, schedules of reinforcement.
What the Eczema Area and Severity Index score tells us about the severity of atopic dermatitis: an interpretability study.

SummaryBackground The Eczema Area and Severity Index (EASI) is an investigator-assessed instrument measuring the severity of clinical signs in atopic dermatitis (AD). The EASI was identified as one of the best-validated outcome measures for AD; however, no previous studies address how to interpret the EASI score for clinical use. Objectives To evaluate the interpretability and the ease of use of the EASI. Methods A retrospective analysis of paediatric and adult patients with AD was performed. Interpretability was evaluated by stratifying the EASI scores according to the Investigator's Global Assessment. The severity strata displaying the highest kappa coefficient of agreement were then selected as the recommended EASI band. The time to administer the EASI was recorded in a subgroup of patients. Results The suggested severity strata for the EASI are as follows: 0 = clear; 0·1–1·0 = almost clear; 1·1–7·0 = mild; 7·1–21·0 = moderate; 21·1–50·0 = severe; 50·1–72·0 = very severe (κ = 0·75). The EASI was also found to be acceptable in terms of ease of use, with assessments by trained investigators taking approximately 6 min. Conclusions Our study provides the first guide for interpreting the EASI score. It enables translation of the EASI numerical output into an AD global severity state that should be more meaningful to providers and patients. Along with a short administration time, the EASI demonstrates adequate feasibility, further supporting its use in clinical trials.
Impact of prior bariatric surgery on maternal and fetal outcomes among obese and non-obese mothers

To assess the association between bariatric surgery and pregnancy-related outcomes among obese and non-obese women in the state of Florida. We conducted a population-based, retrospective cohort analysis using vital records and hospital discharge data in Florida during 2004–2007. Women were categorized based on prior bariatric surgery and pre-pregnancy obesity status. Maternal complications (i.e., anemia, pre-eclampsia, gestational diabetes, chronic hypertension, endocrine disorders, cesarean section, prolonged hospital stay) and fetal morbidities [macrosomia, preterm birth, small for gestational age (SGA)] were the outcomes of interest. Adjusted odds ratios (AOR) and 95% confidence intervals (CI) were computed. Mothers with a prior history of bariatric surgery, regardless of obesity status, were more likely to have anemia, chronic hypertension, endocrine disorders, and SGA infants. Classification based on prior history of bariatric surgery and obesity status showed that non-obese mothers with prior bariatric surgery were more likely to have anemia, chronic hypertension, endocrine disorders, and SGA infants, whereas obese mothers without prior bariatric surgery were at greater risk of having gestational diabetes, chronic hypertension, macrosomic infants (AOR = 1.69, 95% CI = 1.65–1.73), and prolonged hospital stay as compared to non-obese mother without prior bariatric surgery. Although prior bariatric surgery is associated with multiple negative maternal and fetal outcomes, it is protective against infant macrosomia in obese mothers. Our findings support the need for preconception/interconception services tailored for former bariatric surgery patients to improve maternal and feto-infant health outcomes.
A new alternative singles rate dead time correction algorithm for use in neutron multiplicity analysis

In this article we extend the neutron multiplicity counting dead time correction scheme devised by Dytlewski to include Singles. In this way a self consistent, item specific, Singles dead time correction is obtained under the same physical assumptions and approximations as are used for the Doubles and Triples corrections. This correction for the Singles count rate also affects the Doubles and Triples dead time correction because it is also the correction needed for the number of coincidence gates opened. We develop the new dead time formula, which we call the Croft–Dytlewski formula, as an action on the Accidentals histogram, and apply it to simulated pulse train data for which the correct results are known. The new formula was found to perform better than the standard ad-hoc Dytlewski Singles dead time correction formula, particularly for highly correlated high count rate items.
Information effects of earnings and dividend announcements on common stock returns: Are they interactive?

Abstract This article reexamines the interaction effect between the concurrently released earnings and divided announcement on common stock returns. On the basis of a synthesis of two models that separately identify the effects of earnings and dividend surprises, it is hypothesized that the total effect of two types of signals should explain the total changes in stock prices without any interaction between them, regardless of their release time. In the ensuing attempt to test this hypothesis, we find that an analysis of this nature is very sensitive to the interval between the two signals and the specified test period surrounding the announcements. The overall test results are not supportive of a corroborative effect between earnings and dividend announcements. This is consistent with our a priori presumption and the observed corporate practice of information disclosures, but not with the findings of an earlier study.
WE‐D‐303A‐08: Nonlinear Kernels as a Visual Analytics Tool for Radiotherapy Treatment Outcomes

Purpose: The most commonly used NTCP and TCP models are acknowledged to be over simplified. The typical approach to determining if a model ‘fits’ the data is to look at residuals of predicted rates, but this is not straightforward in multi‐dimensional modeling problems because data are sparse. It is therefore crucial to develop methods that investigate the goodness of fit of the models over the dataspace. The goal of this work is to investigate a supervised machine‐learning tool for producing contour plots of outcome probability, as a reference against simpler models.Method and Materials: For demonstrative purposes, we used an institutional dataset consisting of 281 patients treated for non‐small cell lungcancer. Two endpoints were investigated: radiation‐induced pneumonitis (n=219), and local control (n=56). Clinical and dosimetric variables were extracted using CERR and logistic regression model building was performed in the DREES software system. Kernel‐based support vector machines with radial basis functions (SVM‐RBF) were used to produce corresponding contour maps of risk levels. Results: The SVM projection plots identified four possible regions based on the risk group and the confidence level: (i) a region of low risk patients with high confidence prediction level; (ii) a region of low risk patients with lower confidence prediction level; (iii) a region of high risk patients with lower confidence prediction level, and (iv) a region of high risk patients with lower confidence prediction level. The SVM‐RBF produces nonlinear contours that differ significantly from the logistic regression contours, with some agreement where the data is most dense. Conclusion: SVM models provide a powerful, automated, tool to help understand NTCP and TCP model fits. We plan to integrate SVM methods within the open‐source DREES modeling system. Partially supported by K25 CA 128809 and R01 CA85181.
When is a failure to replicate not a type II error

Zentall and Singer (2007) challenge our conclusion that the work-ethic effect reported by Clement, Feltus, Kaiser, and Zentall (2000) may have been a Type I error by arguing that (a) the effect has been extensively replicated and (b) the amount of overtraining our pigeons received may not have been sufficient to produce it. We believe that our conclusion is warranted because (a) the original effect has not been replicated despite multiple attempts to do so and (b) the statement that more extended overtraining may be needed itself suggests that the original effect is not reliable.
Intermediates of the borane reduction of some imidazolidines: An AM1 study

Amine(NB)-aminoborane internal complexes and 1,3,2-diazaborolidines were recently identified as intermediates of the borane reduction of imidazolidino[1,2-d]dithiazepines. Theoretical Mo calculations were used to obtain the structural, conformational, and electronic properties and heats of formation of the boron compounds in the framework of the semiempirical AM1 approximation. Internal constraints in the bicyclic system were analyzed through comparisons with the calculated molecular geometries, electron distribution of monocyclic, and open-chain models. The geometry of the five-membered diazaborolidine systems becomes distorted upon building up the complex bicyclic structure, compared to the nearly planar monocycles. The weak coordinative nitrogen–boron bond (calculated bond order around 0.5) in the internal complexes exerts less conformational strains in the adjoining nine-membered ring containing the disulfide than does the covalent NB bond in the corresponding 1,2,3-diazaborolidine. Thus, the internal constraints of the bicyclic system is taken up by the five-membered ring to a lesser degree in the 1,3,2diazaborolidine than in the internal complex. © 1992 John Wiley & Sons, Inc.
Human Capital and Direct Investment in Poor Countries

Abstract Robert Lucas, Richard Easterlin, and others hold that lack of human capital, especially in the sense of formal education and training, explains why poor countries traditionally have received so little capital and technology from rich countries. The evidence presented here is consistent with a significant role for human capital, but it also suggests that Lucas and Easterlin underrate other influences on capital and technology flows, especially political risk and institutional incompatibility among countries. In addition, countries may be denied investment because investors do not respect personal qualities of workers, particularly in Asia.
Statistical studies of intermetallics stressing the validity of three principles

Abstract The design of new materials and the prediction of their properties are becoming an essential component of materials science. Combinations of phase diagram information, structural information and a variety of physical property information are necessary components of such predictive systems. In this paper we analyse structural and chemical data of intermetallic compounds and show how they comply with the following principles: (1) symmetry principles, (2) simplicity principles, (3) chemistry principles. The results of many of the statistics shown in this paper can be used to develop additional information for a knowledge base in a predictive system. With the aid of statistical plots we will demonstrate some practical applications, such as exploring certain research trends and querying the database to narrow down the number of compounds of specific interest.
Discomalleolar and anterior malleolar ligaments: Possible causes of middle ear damage during temporomandibular joint surgery

Damage to structures within the middle ear during surgical manipulation of the temporomandibular joint (TMJ) has been reported. Two structures are proposed as possible intermediaries in this trauma: the discomalleolar ligament (DML), which passes from the malleus to the medial retrodiscal tissue of the TMJ, and the anterior malleolar ligament (AML), which connects the malleus with the lingula of the mandible via the sphenomandibular ligament (SML). It has been hypothesized that when tension is applied to the DML and/or AML, the resulting movement of the malleus could cause damage to the tympanic membrane and associated structures. The objective of this study was to determine whether tension applied to the DML and/or the AML could cause movement of the malleus. With the use of a superior medial approach through the middle cranial fossa, the ligaments connecting the malleus with the mandible were examined in 52 adult/human cadaveric half-heads. Tension applied directly to the SML resulted in movement of the malleus in three specimens. Similar tension applied to the DML did not cause movement of the malleus. Histologic evidence showed a continuity of fibers between the SML and AML. When the mandibular condyle was distracted inferiorly, tension was demonstrated in the SML. The results indicate that the AML via the SML has the potential to cause middle ear damage and is more likely to do so than the DML.
Modification of development in isolated dorsal root ganglia by nutritional and physical factors.

Abstract Dorsal root ganglia isolated from embryonic chicks of 8–10 days normally maintain tissue interrelationships in culture that lead to the progressive differentiation of the cellular community. By modifying the nutritional or physical conditions of cultivation in this system it is possible to dissociate certain elements of the developmental complex, suppressing one cell function while advancing another. By this means it has been shown that the production and storage of Nissl substance in the neuron is independent of the development of supporting cells and the differentiation of other structures. The formation of reticulin capsule and sheath is dependent upon a specific relationship of satellite and Schwann cells to the neuron, but quite independent of the maturation of the soma. The formation of myelin appears to depend upon both the chromidial maturation of the neuron soma and an appropriate relationship between Schwann cell and axis cylinder. The altered shape which some cultural conditions impose on neurons may be a limiting factor to their later development and survival. Several chemically defined media that are adequate for long-term propagation of strains of mouse fibroblasts are not adequate for differentiation or maintenance of this heterogeneous developing chick system.
Effective thermal conductivity of a matrix with two kinds of inclusions

Previous approximations for the effective conductivity of a matrix with inclusions of low conductivity, and for the effective resistivity of a matrix with inclusions of high conductivity, are combined to give the effective conductivity when both types of inclusions are present. This applies, for example, to a ceramic which contains both pores and metallic inclusions.
Effect of High Dietary Zinc upon Zinc Metabolism and Intracellular Distribution in Cows and Calves

Changes in the metabolism of zinc were investigated in mature nonlactating Holstein cows and 4-mo old calves fed high but nontoxic amounts of dietary zinc. Increasing dietary zinc of calves from 42 to 642 ppm elevated the zinc content of liver and pancreas 600% and 1400%, respectively. The elevated zinc in liver and pancreas involved a substantial increase in all intracellular fractions, with by far the largest amount associated with a 10,000 molecular-weight protein in the soluble cell fraction. This zinc-binding protein may protect the cell against damage from increased zinc. A comparable increase in dietary zinc of mature cows did not affect zinc content of liver or kidney nor alter the intracellular distribution of zinc in the liver. In mature cows, homeostatic control mechanisms which regulate the zinc content of tissue are much more effective than in calves. Accordingly, mature cows probably are able to tolerate higher concentrations of dietary zinc.
Two series of rare earth complexes of the 2-thiopyridine N-oxide anion

Abstract Two series of rare earth compounds of the anion 2-thiopyridine N-oxide have been isolated and characterized (i.e. Ln = La, Pr, Sm, Eu, Tb and Er). One series involves only the pyridine N-oxide ligand while the second series also involves aquo ligands. Characterization involves partial elemental analysis, DSC, TGA, IR and UV-vis spectra. The IR spectrum of the coordinated ligand is reassigned when compared to previous authors.
Location and configuration of magma bodies beneath Long Valley, California, determined from anomalous earthquake signals

Recordings of 281 small earthquakes which occurred recently near the southern edge of Long Valley caldera at depths from 1 to 15 km are used to map the subsurface geometry of shear wave attenuating bodies in the caldera. Signatures of these events recorded northwest, north, northeast, and east of Long Valley with ray paths through the caldera are often anomalous in that S wave arrivals have very low amplitudes, and high frequency P and S wave energy is missing for the same station-event combinations. The volcanic and geothermal history of the region suggests that ray paths for these anomalous signals have passed through magma which absorbed much of the S wave energy and also attenuated the higher frequencies. With over 1200 normal and anomalous ray paths through the caldera we have located two apparently massive magma bodies in the central and northwest caldera as well as two more dispersed magma areas in the southern caldera and beneath Crowley Lake. The central magma body extends from 4.5 to at least 13 km beneath the surface, and the northwest body is as shallow as 5.5 km. These two magma bodies are probably connected below about 8 km. Secondary arrivals seen on select seismograms are tentatively interpreted as reverberations inside the central magma chamber and are consistent with the interpreted lateral extent of the magma. The northwest and central magma bodies lie beneath the northwest and southeast corners of the caldera's resurgent dome and probably connect beneath the dome's center. Also the shallower parts of these magma bodies and the southern anomalous area lie beneath the surface expression of the medial graben faults suggesting that structural features seen at the surface of the valley may be related to magma location at depth.
Biology and the moral paradoxes

Considerations from biology suggest (1) that human interests can be generalized as reproductive, involving activities by individuals that tend to promote the survival of their individualized sets of genes; (2) that ethical, moral and legal questions arise out of conflicts of interest that exist because of our history of genetic differences; (3) that human behavior probably always involves egoistic tendencies and moral inconsistency; (4) that the stages of moral development described by social scientists correspond to the patterns of life effort discussed by biologists; (5) that the idealized moral systems of philosophy and religion have been developed as models that are promoted in others but not (or more than) in one's self; and (6) that what are usually seen as the closest approaches to these idealized models are the sources of our most severe problems because they involve between-group competition and strife.
Role of FNA and Core Biopsy of Primary and Metastatic Liver Disease

Objective. To examine our experience with cytology and histology biopsy of the liver and to define methods for improvement of diagnosis of primary liver tumors. Methods. This include retrospective study of 189 biopsies of 185 liver masses for cytological or histological analysis. Patients were subdivided into two groups. Group 1 consisted of 124 suspected metastasis. Group 2 consisted of 61 suspected primary neoplasms. Biopsies were considered positive or equivocal. In equivocal cases, special stains were performed. In Group 2, cases were classified by contrast CT or MRI as to (I) classic HCC, (II) infiltrated HCC, or (Ill) equivocal. Results. Definitive diagnosis was obtained in 117/124 masses (94%) in Group 1, 48/61 masses (79%) in Group 2, and (Ill) equivocal 13 cases in Group II. In two equivocal cases in which special stains were performed, they were reclassified as HCC. In 8/13 cases, CT findings were consistent with HCC. Conclusion. Liver biopsies are useful in obtaining a definitive diagnosis of suspected metastatic liver disease. Biopsy results are less reliable in patients with suspected primary liver tumors. In these situations, strategies can include basing treatment on imaging criteria or use of newer special pathological stains. Advances in Knowledge. Use of newer special immunological stains improves accuracy in definitive diagnosis of primary liver tumors.
Measurement of spontaneous transfer and transbilayer movement of BODIPY-labeled lipids in lipid vesicles

An assay was developed to study the spontaneous transfer and transbilayer movement (flip-flop) of lipid analogs labeled with the fluorescent fatty acid, 5-(5,7-dimethyl BODIPY)-1-pentanoic acid (C5-DMB-) in large unilamellar lipid vesicles comprised of 1-palmitoyl-2-oleoyl phosphatidylcholine (POPC). The assay is based on the concentration-dependent changes in fluorescence intensity that occur when donor vesicles containing a C5-DMB-lipid are mixed with nonfluorescent acceptor vesicles. A kinetic model was developed to describe the time-dependent changes in concentration of a lipid undergoing both spontaneous transfer between unilamellar vesicles and transbilayer movement within the vesicle membranes, and a mathematical solution was obtained. Data were obtained using C5-DMB-labeled analogs of sphingomyelin (C5-DMB-SM), ceramide (C5-DMB-Cer), phosphatidylcholine (C5-DMB-PC), and diacylglycerol (C5-DMB-DAG), and kinetic parameters for each lipid were determined using a nonlinear least-squares fitting program. The half-times for interbilayer transfer of the lipids were C5-DMB-SM (21 s) < C5-DMB-PC (350 s) approximately C5-DMB-Cer (400 s) << C5-DMB-DAG (100 h). C5-DMB-Cer (t1/2 approximately 22 min) and C5-DMB-DAG (t1/2 approximately 70 ms) exhibited rapid spontaneous transbilayer movement, while C5-DMB-SM (t1/2 approximately 3.3 h) and C5-DMB-PC (t1/2 approximately 7.5 h) moved across the bilayer very slowly. These results provide a basis for interpreting the behavior of these lipid analogs in cells.
The forecasting abilities of implied and econometric variance–covariance models across financial measures

Abstract This study evaluates the forecasting ability of implied and econometric forecasting models under statistical and financial evaluation measures. The econometric models outperform the implied model on all criteria. Overall, the exponentially weighted moving average model is the best forecasting model since it produces hedged portfolios with the lowest variance. It also has the ability to time market fluctuations while maintaining minimal capital allocation, and thus enhances profitability when employed as a tool for trading strategies. Our empirical results suggest that firms should explore the use of dynamic statistical forecasting models rather than relying on the implied model.
Optimal experimental design in an epidermal growth factor receptor signalling and down-regulation model.

We apply the methods of optimal experimental design to a differential equation model for epidermal growth factor receptor signalling, trafficking and down-regulation. The model incor- porates the role of a recently discovered protein complex made up of the E3 ubiquitin ligase, Cbl, the guanine exchange factor (GEF), Cool-1 (b-Pix) and the Rho family G protein Cdc42. The complex has been suggested to be important in disrupting receptor down-regulation. We demon- strate that the model interactions can accurately reproduce the experimental observations, that they can be used to make predictions with accompanying uncertainties, and that we can apply ideas of optimal experimental design to suggest new experiments that reduce the uncertainty on unmeasurable components of the system. The epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor which becomes activated upon binding of its ligand, epidermal growth factor (EGF) and signals via phosphorylation of various effectors (1). Besides sending signals to downstream effectors, the activated EGFR also will initialise endo- cytosis which is followed by either degradation or recycling of the receptor. These are the normal receptor down- regulation processes. Persistence of activated receptor on the cell surface can lead to aberrant signalling and transformation of cells (2). In addition, a variety of tumour cells exhibit overexpressed or hyperactivated EGF receptor (3, 4), indicative of the failure of normal receptor down-regulation. We concern ourselves with building a mathematical model of the receptor endocytosis, recycling, degradation and signalling processes that can reproduce experimental data and incorporates the effects of regulating proteins that themselves become active after EGF stimulation. The schematic for the model is shown in Fig. 1. In particular,
Endothelin-1 raises excitability and reduces potassium currents in sensory neurons

Abstract Exposure to endothelin-1 (ET-1, 50 nM) of sensory neurons, acutely isolated from rat dorsal root ganglia (DRG), results in an increase in the number of action potentials elicited by a linear ramp of stimulating current. The changes are complete in 5 min after ET-1 treatment and do not reverse in 5–10 min after ET-1's removal. Neither the resting potential, nor the threshold potential for the first or second action potentials, nor their rate-of-rise or decay, are changed by ET-1 exposure, but the slow depolarizations which occur before the first and second action potentials during the current ramp are increased by ca. 50% by ET-1. The delayed rectifier type of K + currents ( I K ), measured under whole-cell voltage clamp, are depressed by ∼30% during such exposure to ET-1. The voltage-dependent gating of steady-state I K and the current kinetics are unchanged by ET-1, leaving the sole effect as a drop in the number of available channels. I K is affected by ET-1 only in Isolectin B 4 -positive cells, suggesting that there may be a selective action in enhancing impulse activity on this class of nociceptive neuron. This decrease in I K will potentiate the excitability-inducing actions of the previously reported negative shift in tetrodotoxin-resistant Na + channel gating in such neurons.
Testing endothelial vasomotor function: nitric oxide, a multipotent molecule.

The initial description in 1980 by Furchgott and Zawadzki1 of endothelium-derived vasodilator factor has stimulated more than 2 decades of intense research to delineate the basic biology of the endothelium and its importance in the clinical setting.2 Endothelium-derived vasodilator factor has been identified as nitric oxide (NO).2 It is formed in endothelial cells from the amino acid l-arginine by endothelial isoform of NO synthase (eNOS), which is the product of the NOS3 gene.2,3 In addition to producing NO constitutively, the enzyme may be stimulated to increase NO synthesis by a variety of physiological agonists, shear stress, and pharmacological agents. Although discovered as a vasodilator, NO mediates many of the protective functions of the endothelium.4 It limits vascular recruitment of leukocytes by inhibiting the expression of proinflammatory cytokines, chemokines, and leukocyte adhesion molecules.2,4 It inhibits vascular smooth muscle proliferation and platelet adhesion and aggregation.2,4 NO also inhibits the production of tissue factor, a molecule that plays a critical role in the propensity of disrupted atherosclerotic plaques to cause intravascular thrombosis.5 In the setting of risk factors and experimental atherosclerosis, loss of the biological activity of endothelium-derived NO is accompanied by other alterations in endothelial phenotype that further increase the propensity for vasoconstriction, thrombosis, inflammation, and cellular proliferation in the vascular wall.6 Thus, endothelial dysfunction has the potential to contribute to key events in the course of human atherosclerosis. The experimental observations of Furchgott and others have stimulated translational research to elucidate the importance of endothelium-dependent vasodilation in human coronary atherosclerosis. Accordingly, Ludmer and colleagues7 administered the endothelium-dependent dilator acetylcholine into the coronary arteries of subjects undergoing cardiac catheterization. Acetylcholine induced dilation of normal epicardial coronary arteries but induced abnormal vasoconstriction, indicative of endothelial dysfunction, in patients with angiographic evidence of …
Configurable Computing Platforms - Promises, Promises

For some time now, configurable computing has been hailed as the future for application-specific architectures. The purported advantages are well-known: the increasing NRE cost of chip fab is avoided, the same platform can be used for a variety of applications, and implementations can be fixed or upgraded in the field. But in spite of many attempts to move configurable computing platforms into the mainstream, they have yet to achieve their full promise. This talk will explore the barriers that have kept configurable computing on the sidelines thus far, and suggest steps that we might take to take advantage of its full potential.
An Item and Factor Analysis of Danish, Lebanese and United States College Students' Responses to the Marlowe-Crowne Social Desirability Scale

Arabic, Danish and English versions of the Marlowe-Crowne Social Desirability Scale were administered to college students in Lebanon, Denmark and the United States. There were 200 Lebanese, 150 Danes and 200 Americans, each group divided evenly on the basis of sex. The mean raw scores of the Danes, Americans and Lebanese were 9.59, 12.45 and 19. 11, respectively. Separate item analyses yielded a total of 27 common items which correlated significantly with total score in all three groups. Correlations between item rankings across groups ranged from. 53 to. 79 with considerable agreement in the placement of items in the extreme ranks. The factor analyses produced factors which were only moderately similar across groups. It was inferred that the overall findings of the study support the use of the Marlowe-Crowne scale for estimating social desirability with both Danish and Lebanese college students. Sampling limitations, however, mitigate against the uncritical use of the scale within these cultures without ...
Cortical Cell Orientation Selectivity Fails to Develop in the Absence of ON-Center Retinal Ganglion Cell Activity

Neuronal activity is necessary for the normal development of visual cortical cell receptive fields. When neuronal activity is blocked, cortical cells fail to develop normal ocular dominance and orientation selectivity. Patterned activity has been shown to play an instructive, rather than merely permissive, role in the segregation of geniculocortical afferents into ocular dominance columns. To test whether normal patterns of activity are necessary to instruct the development of cortical orientation selectivity, we studied ferrets raised without ON-center retinal ganglion cell activity. The ON-center blockade was produced by daily intravitreal injections of DL-2-amino-4-phosphonobutyric acid (APB). Effects of this treatment on the development of orientation selectivity in primary visual cortex were assessed using extracellular electrode recordings and optical imaging. In animals raised with an ON-center blockade starting after visual cortical cells are visually driven but still poorly tuned for orientation, cortical cell responsivity was maintained, but no maturation of orientation selectivity was seen. No recovery of orientation tuning was seen in animals treated with APB during the normal period of orientation development and then allowed several months of development without treatment. These results suggest that patterns of neuronal activity carried in the separate ON- and OFF-center visual pathways are necessary for the development of orientation selectivity in visual cortical neurons of the ferret and that there is a critical period for this development.
Cilostazol for Prevention of Thrombosis and Restenosis after Intracoronary Stenting

OBJECTIVE:To evaluate the potential use of cilostazol in intracoronary stenting.DATA SOURCES:Clinical literature was accessed through MEDLINE (1966–March 2001). Key search terms included cilostazol, intracoronary stenting, and coronary angioplasty. Abstracts of clinical trials presented at major cardiology professional association meetings were also reviewed.DATA SYNTHESIS:Intracoronary stent placement represents the fastest growing medical device implant. Complications of stent implantation include acute and subacute vessel closure, as well as late restenosis. Currently, antiplatelet agents are used for preventive therapy. Cilostazol is a vasodilating antiplatelet agent that reversibly inhibits platelet aggregation induced by many factors. In seven randomized trials comparing cilostazol with either aspirin or ticlopidine, cilostazol was found to be superior to aspirin and equivalent to ticlopidine in decreasing both cardiac events and rates of restenosis. In addition, cilostazol was found to be well tole...
Relationships among selected attributes and three measures of upper body strength and endurance in elementary school children.

The purpose of this investigation was to assess (a) proportions of children unable to perform each of three measures of upper body strength and endurance—pull-up, flexed-arm hang, and modified pull...
Anaplastic pancreatic carcinoma. A case report and review of literature .

Context :Anaplastic pancreatic carcinoma is an aggressive neoplasm with survival measurable in weeks. It presents as a large cystic mass with loco-regional and distant spread. Three histological types have been described: pleomorphic, spindle cell and sarcomatoid. Case report We describe the case of a 74- year-old woman with pleomorphic anaplastic carcinoma of the pancreas diagnosed after laparoscopic biopsy. The patient had a rapid downhill course with progression of the disease and demise within 4 weeks after diagnostic laparoscopy. Conclusion Due to the rapid spread of the disease, no effective cure exists for these tumors. A brief review of the histological and radiological findings and the possible mechanisms of the pathogenesis of anaplastic tumors is included in the discussion..
Motivating Appropriate Challenges in a Reciprocal Tutoring System

Formalizing a student model for an educational system requires an engineering effort that is highly domain-specific. This model-specificity limits the ability to scale a tutoring system across content domains. In this work we offer an alternative, in which the task of student modeling is not performed by the system designers. We achieve this by using a reciprocal tutoring system in which peer-tutors are implicitly tasked with student modeling. Students are motivated, using the Teacher's Dilemma, to use these models to provide appropriately-difficult challenges. We implement this as a basic literacy game in a spelling-bee format, in which players choose words for each other to spell across the internet. We find that students are responsive to the game's motivational structure, and we examine the affect on participants' spelling accuracy, challenge difficulty, and tutoring skill.
Exploring the Relationship between Global Quality and Group Engagement in Toddler Child Care Classrooms.

Toddlers’ engagement with their social and physical environment is an important aspect of their experience in early care and education programs. The purpose of this research study was to examine ho...