cssi/SciSciGPT-SciSciNet huggingface dataset:
Chapter 8 – Laboratory Detection of Human Retroviral Infection

This chapter reviews the methods and limitations of assays to detect evidence of HIV exposure, and provides an approach to the rational use and interpretation of these tests. To interpret past literature, an historical context is also provided. The armamentarium of HIV and HTLV detection systems has continued to grow rapidly. Testing alternatives continue to move from the research bench to the clinical laboratory. The judicious choice of these tools depends upon an increased understanding of the dynamics of retroviral infection, critical head-to-head comparison testing, and cost-benefit decision analyses. Further development and evaluation are warranted for direct HIV-detection methods as well as other immunologic tests of HIV exposure and serologic detection and confirmation of HTLV infection. The context within which any test is used is of critical importance to its interpretation. No test, per se, should be the basis for diagnosis on its own, but rather, a test is merely an aid in correct diagnosis. The practitioner must use test results in the context of a clinical picture to reach an accurate diagnosis.
Seasonal acclimatization to temperature in cardueline finches

1. Seasonal variation in body constituents and utilization of lipid, protein, and carbohydrate during cold stress in American goldfinches were studied to determine relations of these functions to the pronounced seasonal shift in thermogenic capacity documented in a previous study (Dawson and Carey, 1976). 2. Mean body mass for adults increases from a low of 11.4 g in July to a high of 15.1 g in December and January. Seasonal variation in lipid content accounts for the major part of the observed changes in body mass, but such variation in water and protein content is also appreciable. 3. Linoleic acid (18∶2) is the predominant fatty acid in neutral lipids of liver, pectoralis muscle, and furcular depots at all seasons. Unsaturated fatty acids comprise a much greater proportion of total fatty acids in liver and pectoralis muscle during winter (71% and 73%, respectively) than in spring or fall. 4. Fasting winter goldfinches exposed to −10°C for 17 h overnight utilize significant amounts of body lipid. However, total body protein, liver and pectoralis muscle carbohydrate, and pectoralis muscle fatty acids do not differ significantly between control and cold-stressed individuals. 5. Glycogen stores in the pectoralis muscles are significantly higher in winter than in summer birds. Winter goldfinches exposed to −70°C utilize significant amounts of total body lipids and pectoralis glycogen. Birds tested in this manner in summer do not do so and quickly become hypothermic. 6. Histochemical characteristics and succinate oxidase activities of pectoralis muscles do not vary appreciably over the year. 7. Increased stores of body lipid and muscle carbohydrate and the ability to mobilize these substrates rapidly during cold stress seem to be key factors in the superior thermogenic capacities of winter goldfinches.
The Theory of Common Markets as Applied to Regional Arrangements Among Developing Countries

By and large the theory of customs unions has been confined to considerations of welfare gains or losses arising from a disturbance of the existing pattern of trade which is assumed to reflect comparative advantages in the commodities traded as determined by existing factor endowments. Some attention has been paid to the realization of gains from the economies of scale and from increased competition. However, the effects of the creation of regional markets on the more fundamental problems of developing countries such as increasing opportunities for profitable foreign and domestic investment, broadening the export base, achieving balance of payments equilibrium, mobilizing unemployed resources and avoiding economic dualism, have been largely neglected. Some of these problems, which are concerned with the dynamics of economic growth, are of interest to under-developed and to industrially advanced countries alike. I doubt, for example, if the most significant gains from the creation of the European Economic Community are to be discovered through a comparison of trade-diverting and trade-creating effects on welfare, even if we could measure them. Rather, the major impact will occur as a consequence of the effects on entrepreneurial decisions arising out of the new market structure and out of the acute awareness of the continual generation of new products, new processes and new methods of distribution on the part of competitors within the broad regional market.
Thiogalactoside transacetylase. Amino- and carboxyl-terminal studies.

Abstract Carboxypeptidase digestion of denatured thiogalactosidase transacetylase showed that the COOH-terminal sequence is Ser-Val and that 2 moles of valine are released per mole of protein. Although this is consistent with the previous finding that the protein is composed of two identical chains, studies of the NH2 terminus show heterogeneity and lack of stoichiometry. Instead of 2 moles of a single amino acid per mole of protein, 0.5 mole of aspartic acid (or asparagine) and 0.4 mole of methionine were found by both the Sanger and the Stark and Smyth procedures. The same result was obtained after treatment of the protein under conditions expected to cleave α-N-formyl groups. Various explanations to account for these findings are discussed, including blocked NH2-terminal end groups, proteolytic hydrolysis, and random cleavage as a consequence of a step in protein biosynthesis.
Frequency-domain penalized least-squares beamformer design for early detection of breast cancer via microwave imaging

Microwave imaging has been proposed as an alternative to X-ray mammography for early-stage breast cancer detection. We investigate a method of microwave imaging via space-time (MIST) beamforming for detecting backscattered energy from small malignant breast tumors. The beamformer weights are designed to optimally compensate for frequency-dependent propagation effects and minimize clutter by solving a set of penalized least-squares problems that are formulated in the frequency domain. We demonstrate the efficacy of our space-time beamforming approach using backscatter data acquired from two types of breast phantoms: a realistic numerical breast model and a simple experimental breast phantom. The numerical model is derived from a magnetic resonance image of the breast and the backscatter waveforms are computed using the finite-difference time-domain method for solving Maxwell's equations. The experimental phantom consists of a synthetic tumor suspended in a homogeneous liquid. The dielectric-properties contrast between the liquid and synthetic tumor is similar to the contrast between normal and malignant breast tissue. Our images exhibit high signal-to-clutter ratios and good tumor localization even under various challenging conditions.
Registering two overlapping range images

The paper describes a method of automatically performing the registration of two range images that have significant overlap. We first find points of interest in the intensity data that comes with each range image. Then we perform a triangulation of the 3D range points associated with these 2D interest points. All possible pairs of triangles between the two 3D triangulations are then matched. The fact that we have 3D data available makes it possible to efficiently prune matches. We do this pruning by using a simple and effective set of compatibility tests between potentially matching triangles and vertices. The best match is the one that aligns the largest number of interest points between the two range images. The algorithms are demonstrated experimentally on a number of different range image pairs.
Fostering Resilience: A Necessary Skill for Teacher Retention

The goal of this qualitative 2-year study was to examine the resilience building process in four novice secondary science teachers and its link to teacher retention. To achieve the research goal, a resilience framework was established. Three factors were instrumental in creating the framework. The first focused on stressors and protective factors in the lives of novice secondary science teachers and provided direction and goals for the research. Second, a case study was developed for each of the four teachers participating in the research in order to emphasize the detailed analysis of factors linked to resilience. Finally, cross-case analysis was employed to identify similarities and differences and provide insight into issues concerning the resilience process. Results of this study suggest that the interaction between stressors and protective factors acts as a primary force in the resilience process and stimulate responses to help counteract negative effects of resulting stress. Therefore, it can be reasoned that resilience can be fostered in novice teachers as a means to encourage teacher retention.
Biosynthesis and secretion of milk proteins: a review

Recent years have seen a great increase in the knowledge and understanding of milk proteins. Arising from several origins including the blood stream and various cellular sources, many of the proteins found in milk are products of the secretory cells directly involved in the synthesis and secretion processes of various milk components. The lactation-specific proteins present in major amounts are synthesized in the rough endoplasmic reticulum (RER) under genetic control and undergo further post-translational modifications in their secretory route from the RER through the Golgi apparatus and secretory vesicles before ejection into the lumen with other milk components. Various molecular aspects of these mechanisms and their control are now understood, but many remain to be described.
Isomeric Forms of the Products of the Collisional Associations of CH3+ with CH3OH and H3O+ with C2H4

A selected ion flow tube has been used to study the reactions of C2H7O+ generated by the collisional associations of CH3+ with CH3OH and H3O+ with C2H4. Reactions with C2H5OCHO, (CH3)2CHOH, CH3CO2H, CH3C6H5, CH3CHO, H2CCCH2 (allene), CH3OH, c-C3H6, H2O, and C2H6 were studied to give information on the isomeric forms of the C2H7O+ ions. The data were compared with previous data on the reactivity of other isomeric forms, (CH3)2OH+ and C2H5OH2+, with the same reactant neutrals. The rate coefficient data show a very strong correlation between the reactivities of (CH3)2OH+ and the associated ion CH3+/CH3OH and between C2H5OH2+ and H3O+/C2H4, indicating that the associated ions are similar in form to these strongly bonded species. This is consistent with conclusions based on potential energy surfaces calculated in the accompanying paper. The agreement between the product ion distributions is not so conclusive. Generally, where proton transfer is exothermic for the strongly bonded species, it occurs rapidly for ...
ADVANTAGES AND LIMITATIONS OF MEDICAL ASSISTANTS

An outline is given of the experience at Duke University with training young men for the manpower category of Physician Assistant. The selection of candidates, the two-year training course and the post-certification duties are described. Despite the stated problems and dangers, the results to date have been most encouraging.
Experimental investigation of purely elastic instabilities in periodic flows

Abstract Purely elastic instabilities in the flows of polyisobutylene-based Boger fluids in the periodic channel (PC) and past a (linear) periodic array of closely spaced cylinders (PAC) in a channel have been experimentally examined. The test geometries have the same wavelength and amplitude associated with the periodic variation in the cross-sectional area. Pressure measurements show temporal fluctuations that appear when the Weissenberg number exceeds approximately 0.7 and 1.1 for the PC and PAC geometries, respectively. Flow visualization using digital particle imaging velocimetry (DPIV) shows that below the critical Weissenberg number, flows are two-dimensional and steady consisting of slow vortex motion in the wake region for the flow past the PAC flow and in the near wall region for the PC flow. Inception of flow instability results in the breakdown of the symmetric vortices in the flow past the PAC flow and in time-dependent vortex motion in the PC flow. The onset of flow instability is also accompanied by enhanced flow resistance. The power spectral composition of the pressure fluctuations is uniform along the flow direction for both geometries. This implies that in time-dependent simulations a unit cell with periodic boundary conditions can faithfully represent these geometries. The onset Weissenberg number values, when scaled with the maximum curvature of the streamlines, are very close to each other indicating that the instability arises from the coupling between streamline curvature and elastic normal stresses.
Boltzmann equation solver adapted to emergent chemical non-equilibrium

We present a novel method to solve the spatially homogeneous and isotropic relativistic Boltzmann equation. We employ a basis set of orthogonal polynomials dynamically adapted to allow for emergence of chemical non-equilibrium. Two time dependent parameters characterize the set of orthogonal polynomials, the effective temperature T ( t ) and phase space occupation factor ? ( t ) . In this first paper we address (effectively) massless fermions and derive dynamical equations for T ( t ) and ? ( t ) such that the zeroth order term of the basis alone captures the particle number density and energy density of each particle distribution. We validate our method and illustrate the reduced computational cost and the ability to easily represent final state chemical non-equilibrium by studying a model problem that is motivated by the physics of the neutrino freeze-out processes in the early Universe, where the essential physical characteristics include reheating from another disappearing particle component ( e ? -annihilation).
Locational dynamics of automobile dealerships and explanations for spatial clustering

This paper examines the locational dynamics of automobile dealerships in a USA metropolitan area for the period 1950 to 1990. This retailing activity has shifted from CBD locations in the 1950s and 1960s to suburban sites along major commercial ribbons in recent decades. Dealerships have become concentrated into a small number of large suburban clusters with the spacing between clusters influenced by territorial security concerns for dealers selling the same make of automobile. The strong clustering tendency of dealerships has been attributed to comparison shopping opportunities for consumers and advertising advantages to sellers. However, other important factors contributing to the establishment and expansion of these clusters include the availability of attractive locational opportunities, constraints placed on franchise locations by franchise contracts and state legislation and the ownership of multiple dealerships (mega-dealers) by a single firm or individual.
Bright-state expansion and optimal control of highly excited polyatomics

Abstract A basis expansion of a quantum state of a molecule in a small orthogonal set of dynamically motivated, active bright states is presented and tested. The active bright states are derived from wavepackets (in a discrete variable representation) corresponding to different times in the time evolution of the molecule in a specified external laser field. Time evolution using the active bright-state representation is computationally less intensive and contains the essential dynamics in the quasiharmonic, quasicontinuum, and continuum regimes. Knowledge of the exact molecular spectroscopy is not needed. The active bright-state representation is thus well suited for optimal-control calculations which require a large number of wavepacket propagations.
Power-aware FPGA logic synthesis using binary decision diagrams

Power consumption in field programmable gate arrays (FPGAs) has become an important issue as the FPGA market has grown to include mobile platforms. In this work we present a power-aware logic optimization tool that is specialized to facilitate subsequent power-aware technology mapping. Our synthesis framework uses binary decision diagram (BDD) based collapsing and decomposition techniques in conjunction with signal switching estimates to achieve power-efficient circuit networks. The results of synthesis and subsequent power-aware technology mapping are evaluated using two distinct physical design platforms: academic VPR and Altera Quartus II. Our approach achieves an average energy reduction of 13% for Altera Cyclone II devices versus synthesis with SIS-based algebraic optimization at the cost of 11% average circuit performance if performance-optimal technology mapping is performed after synthesis. If technology mapping is tuned to achieve the same average delay for both SIS and BDD-based flows, a 3% average energy reduction is achieved by our new synthesis approach.
Generalized Descent Methods for Asymmetric Systems of Equations

We consider generalizations of the steepest descent algorithm for solving asymmetric systems of equations. We first show that if the system is linear and is defined by the matrix M, then the method converges if M2 is positive definite. We also establish easy to verify conditions on the matrix M that ensure that M2 is positive definite, and develop a scaling procedure that extends the class of matrices that satisfy the convergence conditions. In addition, we establish a local convergence result for nonlinear systems defined by uniformly monotone maps, and discuss a class of general descent methods. All of the methods that we consider reduce to standard nonlinear programming algorithms for equivalent optimization problems when the Jacobian of the underlying problem map is symmetric. We interpret the convergence conditions for the generalized steepest descent algorithms as restricting the degree of asymmetry of the problem map.
THERMODYNAMIC STUDIES ON DOLOMITE FORMATION AND THEIR GEOLOGIC IMPLICATIONS: AN INTERIM REPORT

SUMMARY Many theories have been advanced for the origin of sedimentary dolomites. Yet some of these theories are chemically and thermodynamically unsound. The present paper is an interim report on the study of thermodynamics (and chemistry) of dolomite formation. It is hoped that this and other similar papers on chemistry and thermodynamics of dolomite formation will prevent the perpetuation of unsound and untenable theories in the geological literature.
Creative industries in East Asia

Throughout East Asia, the growth process and its sources are changing in a number of important respects, especially for middle and higher income economies. Growth will increasingly come from the strength of innovative activities in these economies instead of factor accumulation as in the past. Recent research suggests that such innovative activities, especially in producer services and the creative industries, are concentrated in high-tech clusters in globally linked cities. The development of such cities is influenced by ongoing structural changes and initiatives by governments and firms. This paper explores these issues and suggests how policies and institutions can induce and furnish an urban environment that supports innovative activities that in turn lead to rapid growth.
Use of the stages of change in exercise adherence model among older adults with a cardiac diagnosis.

PURPOSE: Researchers have recommended use of the Stages of Change in Exercise Adherence (STAGES), a process-oriented model, to better understand exercise adherence behavior. This study aimed to further understand the process by evaluating the predictors of exercise adherence and the validity of the STAGES model among older adults (N = 349) with a cardiac diagnosis after discharge from a cardiac rehabilitation inpatient program. METHODS: Recently discharged inpatient participants, aged 65 years or older and ambulatory, responded to a computer-assisted telephone interview regarding their exercise behaviors and attitudes toward exercise (mean response time = 32.3 minutes). Between 55 and 80 participants in each of five stages of exercise adherence were interviewed. Demographic profiles and other information were obtained from a chart review of cardiac rehabilitation inpatient records. RESULTS: Perceived self-efficacy, perceived benefits of exercise, interpersonal support for exercise, and perceived barriers to exercise were significant predictors of exercise adherence using direct entry discriminant analysis. These predictors accounted for 50% of the variance in stage of exercise adherence. The theoretical ordering of the STAGES model was supported (P < .0001). Exercise time significantly increased with each subsequent stage of exercise adherence from the precontemplation stage to the maintenance stage. CONCLUSIONS: This study evaluated the validity of the STAGES model in a sample of older cardiac rehabilitation participants. The STAGES model can be applied to the study of exercise behavior among this group of older adults.
Dispersion of Acoustic Waves By an Alumina-Epoxy Mixture

A differential-path ultrasonic technique is used to obtain the acoustic wave propagation characteristics of a mixture of alumina (Al2O3) particles and epoxy (Epon 828-Z). Longitudinal and shear acoustic data are ob tained over a frequency range of 0.5 to 2 MHz and a temperature range of —61°C to 75°C. The longitudinal, shear, and Poisson's ratio master-curve material functions are derived from these data using techniques that were developed for homogeneous isotropic polymers. These functions constitute a complete material description for the mixture in the time (frequency) and temperature range where viscoelastic dispersion is the dominant disper sion mechanism in the composite.
A labeling study of π-cycloheptatrienetricarbonylchromium(0)

Peaks of different intensities in the mass spectra of π-toluenetricarbonylchromium and π-cycloheptatrienetricarbonylchromium were studied by deuterium labeling of the latter compound. Incomplete hydrogen randomization in cycloheptatriene ligands preceding different reactions was observed, in contrast to the results for cycloheptatriene itself.
Methodology in Business Ethics Research: A Review and Critical Assessment

Using 94 published empirical articles in academic journals as a data base, this paper provides a critical review of the methodology employed in the study of ethical beliefs and behavior of organizational members. The review revealed that full methodological detail was provided in less than one half of the articles. Further, the majority of empirical research articles expressed no concern for the reliability or validity of measures, were characterized by low response rates, used convenience samples, and did not offer a theoretic framework, hypotheses, or a definition of ethics. Several recommendations, including a reviewer rating form addressing methodological decisions and inclusion of methodologists on the review panel, are offered to improve methodological rigor in published ethics research.
Testing the Efficacy of a Computer-Based Parent-Adolescent Sexual Communication Intervention for Latino Parents

The efficacy of a computer-based intervention to increase parent-adolescent communication among Latino parents and adolescents was tested in a randomized controlled trial. Parents assigned to receive the 2-session intervention reported greater general communication, sexual communication, and comfort with communication at 3 month follow-up than did parents assigned to the wait-list control condition. Adolescents, whose parents received the intervention, reported higher sexual communication than did adolescents whose parents were in the wait-list control condition. Results provide support for the efficacy of brief parent interventions designed to maximize adolescent support systems. The acceptability of the computer-based format for an underserved population provides an important venue for the delivery and use of health information.
Correlation-Based Rectangular Encoding

In this paper, a technique is presented for improving the compression achieved with any linear decompressor by adding a small nonlinear decoder that exploits bit-wise and pattern-wise correlations present in test vectors. The proposed nonlinear decoder has a regular and compact structure, and allows continuous-flow decompression. It has a very important feature, which is that its design does not depend on the test data. This simplifies the design flow and allows the decoder to be reused when testing multiple cores on a chip. Experimental results show that combining a linear decompressor with the small nonlinear decoder proposed here significantly improves the overall compression.
Population Control in India: Prologue to the Emergency Period

Some 30 years after the event the Emergency Period remains the one episode in the history of family planning in India that would appear to require no introduction. It has become emblematic of everything that can go wrong in a program premised on "population control" rather than on reproductive rights and health. This included time-bound performance targets; a preference for methods that minimized the need for sustained motivation; disregard for basic medical standards; incentive payments that for the very poorest constituted a form of coercion; disincentives that punished nonparticipation; and official consideration of compulsory sterilization which even if never enacted into law signaled that achieving national population targets might override individual dignity and welfare. (excerpt)
Polymer-protein conjugates. II. Affinity precipitation separation of human immunogammaglobulin by a poly(N-isopropylacrylamide)-protein A conjugate.

The conjugate of protein A with poly(N-isopropylacrylamide) was synthesized and utilized in the separation of human immunogammaglobulin. In the separation process, poly(N-isopropylacrylamide)-protein A conjugate binds to the immunoglobulin with high specificity to form the poly(N-isopropylacrylamide)-protein A/immunoglobulin complex. The complex can be conveniently separated by precipitation upon heating above the lower critical solution temperature of the poly(N-isopropylacrylamide)-protein A/immunogammaglobulin complex. The separation capacity of poly(N-isopropylacrylamide)-protein A conjugate for human immunogammaglobulin was studied and it was demonstrated that approximately one out of every four protein A molecules binds to human immunogammaglobulin with a dissociation constant (Ks) of 3 × 10−6 m. The affinity precipitation separation of human immunogammaglobulin is a rapid process which avoids the need for chromatographic columns. It can also be designed to run in a continuous mode.
Should further mergers be allowed? Product differentiation and merger in the external audit market

The external audit market in US is a market with noticeable features: a highly concentrated market, various choice patterns of auditors and the sequential mergers of big auditors over time. There has been growing concern about the impact of mergers and the increasing market concentration. Using a flexible multinomial probit model and micro level data on over 3000 public companies, this article investigates production differentiation and merger in the external audit service market between the Big Four accounting firms. Based on the estimation results of the demand estimates, a model of post-merger conduct is then used to simulate the competitive effects of a merger. The results suggest that merger effects on prices in this market are not significant with no larger than 3%.
35nm SOI-CMOS for Sub-Ambient Temperature Operation

We demonstrate over 40% CMOS performance gain with minimal process changes by lowering the operating temperature from 100degC to -50degC. For the same performance, the lower temperature operation delivers a 60% reduction in power-delay product at a reduced supply voltage. Coupled with recent advances in liquid cooling techniques, our results suggest that sub-ambient temperature operation is an attractive option for high performance and energy-efficient CMOS.
Survival and self-renewing capacity of breast cancer initiating cells during fractionated radiation treatment.

Recent data indicate a hierarchical organization of many solid cancers, including breast cancer, with a small number of cancer initiating cells (CICs) that have the ability to self-renew and exhibit multi-lineage potency. We, and others, have demonstrated that CICs in breast cancer and glioma are relatively resistant to ionizing radiation if compared to their non-tumorigenic counterparts. However, the extent of the remaining self-renewing capacity of CICs after fractions of radiation is currently unknown. We hypothesized that CICs, in contrast to their non-tumorigenic counterparts, not only survive fractions of ionizing radiation but also retain the CIC phenotype as defined by operational means. We used two marker systems to identify breast CICs (CD24-/low/CD44high, or lack of proteasome activity) and performed sphere-forming assays after multiple clinical fractions of radiation. Lineage tracking was performed by membrane staining. Cell cycle distribution and RNA content were assessed by flow cytometry and senescence was assessed via β-galactosidase staining. We demonstrated that irradiated CICs survived and retained their self-renewal capacity for at least four generations. We show that fractionated radiation not only spared CICs but also mobilized them from a quiescent/G0 phase of the cell cycle into actively cycling cells, while the surviving non-tumorigenic cells were driven into senescence. The breast CIC population retains increased self-renewal capacity over several generations and therefore, we conclude that increases in the number of CICs after sublethal doses of radiation have potential clinical importance. Prevention of this process may lead to improved clinical outcome.
Geophysical Investigations at an Abandoned Mine Site Subjected to Reclamation Using a Fixated Scrubber Sludge Cap

A series of geophysical investigations were undertaken to evaluate relationships between sources and areas of groundwater contamination and the effects of reclamation on groundwater quality in part of an abandoned mine land site in the coal-mining district of Indiana. Prior to reclamation, acidic groundwater was perennially draining from a deposit of coarse refuse that was the main source of contaminated water leaving the site. Fixated scrubber sludge (FSS) was used as a capping material to isolate the pyritic refuse from further recharge, and the FSS was in turn capped by a layer of soil material. The buried refuse and associated plume of acidic groundwater could be seen as a low-resistivity layer when an electrode spacing of 16 m was deployed in an Offset Wenner configuration. An electromagnetic terrain conductivity survey was undertaken in conjunction with a magnetometry survey to identify the areas of high metal (pyrite) content and acidic groundwater. A comparison between the apparent conductivity distribution and a map of the prereclamation distribution of mine waste indicated that the plume of acidic groundwater had migrated toward, but not reached, the surface-water outlet of the site. Repeated measurements of soil-moisture profiles from the surface into the buried refuse revealed the FSS layer to be a zone of no moisture change, which indicated that the layer was serving as an effective barrier to further recharge of the aquifer in the buried refuse. Continuous monitoring of water levels in the buried refuse and the soil layer above the FSS confirmed that water was perching on the layer of FSS. Iron concentrations in samples of water collected from the well that was screened in the refuse declined from a maximum of 6,000 mg/L prior to reclamation to <2,000 mg/L three years after the FSS was applied.
Powdered Sorbent Liver Dialysis and Pheresis in Treatment of Hepatic Failure

The Liver Dialysis Unit (the Unit) is a liver-assist device that employs hemodiabsorption (dialysis of blood against powdered sorbents) to selectively remove numerous small molecular weight toxins of hepatic failure. The Unit has been cleared by the Food and Drug Administration and is indicated and marketed for treatment of acute hepatic encephalopathy (AHE) due to decompensation of chronic liver disease (A-on-C) or fulminant hepatic failure (FHF). Controlled, prospective, and randomized studies of liver dialysis were conducted at several centers, enrolling 56 patients with AHE, grades II-IV with or without renal and respiratory insufficiency or failure. Liver dialysis treatments were for 6 h daily, 1-5 days with similar observation periods for control patients. Physiologic status, neurologic status, and outcome (recovery of hepatic function, improvement for transplant, or death) were measured, and results were compared for treated patients versus controls for patients with A-on-C and patients with FHF. Liver dialysis resulted in physiologic and neurologic improvement of patients with AHE, regardless of etiology. Liver dialysis significantly improved the incidence of positive outcomes (recovery of hepatic function or improvement for transplant) of A-on-C patients versus controls (71.5% treated, 35.7% control, p = 0.036), but had an insignificant improvement in the outcome of patients with FHF as compared with the control group. Among the overall 31 treated patients, 51.6% survived. Outcome was not negatively affected by the presence of kidney failure or respiratory failure. The plasmafilter unit (PF-Unit) combines hemodiabsorption with push-pull sorbent-based pheresis (the PF add-on module, with powdered sorbent surrounding plasmafilters). At blood flow rates of 200 ml/min, the system clears creatinine and aromatic amino acids at 120-160 ml/min, unconjugated bilirubin at 20-40 ml/min, and cytokines at 15-25 ml/min. The PF-Unit has been tested in a few patients with hepatic failure with Grades III and IV encephalopathy, and respiratory, and kidney insufficiency. Treatment appeared to be safe, and there were no significant hematologic changes. Physiologic changes included improved blood pressure, and encephalopathy, and stable urine output. Chemical changes included a decrease in the plasma levels of bilirubin, aromatic amino acids, ammonium, creatinine, and IL-1beta. The PF add-on module adds the capability to the Unit to remove bilirubin and other strongly protein-bound toxins from treated patients and may be of clinical benefit in the management of patients with the most severe hepatic failure and encephalopathy, including patients with FHF or concomitant sepsis.
Distribution and colocalization of cholecystokinin with the prohormone convertase enzymes PC1, PC2, and PC5 in rat brain.

During posttranslational processing to generate CCK 8, pro-cholecystokinin (CCK) undergoes endoproteolytic cleavage at three sites. Several studies using endocrine and neuronal tumor cells in culture and recombinant enzymes and synthetic substrates in vitro have pointed to the subtilisin/kexin-like enzymes prohormone convertase (PC) 1, PC2, and PC5 as potential candidates for these endoproteolytic cleavages. In these experimental models, they all appear to be able to cleave pro-CCK to make the correct products. One rodent model has provided information about the role of PC2. PC2 knockout mouse brains had less CCK 8 than wild-type, although a substantial amount of CCK was still present. The degree to which CCK levels were reduced in these mice was regionally specific. These data indicated that PC2 is important for normal production of CCK but that it is not the only endoprotease that is involved in CCK processing. To evaluate whether PC1 and PC5 are possible candidates for the other enzymes involved in CCK processing, the distribution of PC1, PC2, and PC5 mRNA was studied in rat brain. Their colocalization with CCK mRNA was examined using double-label in situ hybridization. PC2 was the most abundant of these enzymes in terms of the intensity and number of cells labeled. It was widely colocalized with CCK. PC1 and PC5 mRNA-positive cells were less abundant, but they were also widely distributed and strongly colocalized with CCK in the cerebral cortex, hippocampus, amygdala, ventral tegmental area, and substantia nigra zona compacta. The degree of colocalization of the enzymes with CCK was regionally specific. It is clear that PC1 and PC5 are extensively colocalized with CCK and could be participating in CCK processing in the rat brain and may be able to substitute for PC2 in its absence. These three enzymes may represent a redundant system to ensure production of biologically active CCK.
A numerical investigation of wake deformation in density stratified fluids

The collapse shape and internal velocity field of an initially circular homogeneous fluid mass surrounded by a linearly stratified fluid are computed. During the initial stage of collapse, the fluid is assumed to be irrotational and inviscid while in later stages the Navier-Stokes equations are solved numerically by a modification of Chorin's primitive variable decomposition method. The final stage is analyzed by means of an asymptotic viscous long-wave theory.
UThPb and SmNd isotopic systematics of the Goalpara ureilite: Resolution of terrestrial contamination

The UThPb and SmNd isotopic systematics of mineral separates from the Goalpara ureilite were studied after applying acid leaching techniques. The separates were successively leached with dilute HBr and HNO3 in order to remove any secondary Pb components in the meteorite as well as to separate a light REE-rich component which has been known to be dissolved using a similar acid leaching procedure. The leachates contained large amounts of terrestrial Pb as well as significant amounts of U, Th, Sm, and Nd, whereas the residues were highly depleted in all five of these elements (between 0.1 and 0.001 times CI chondritic abundance). The UPb, ThPb, and SmNd isotopic systematics can be interpreted as mixtures of highly depleted ureilite and terrestrial contamination in all fractions. For this reason, precise ages could not be obtained from any of these systems. The lead isotopic compositions in the residues are considered mixtures of terrestrial Pb and primordial meteoritic Pb (Canon Diablo troilite Ph) with a small amount of radiogenic Pb. However, on a UPb concordia diagram the residues indicate a formation age as old as 4.55 Ga, assuming the UPb data represent a mixture of terrestrial and ureilite U and Pb. Similarly, SmNd systematics of the residues form a mixing line between the composition of 4.55-Gy old material and an average terrestrial crustal composition, yielding a 3.74-Ga pseudo-isochron. Furthermore, the acid leachates show terrestrial signatures of ThU and SmNd ratios, and Pb and Nd isotopic ratios. Therefore, it is doubtful that the so-called light REE-rich component in ureilites is indigenous, and that the implied metasomatic event on the ureilite parent body is real.
Total cross sections for some (α, n) and (α, p) reactions in medium-weight nuclei

Abstract Total cross sections have been measured for the 45 Sc(α, n), 46 Ti(α, n), 50 Cr(α, n), 51 V(α, n), 54 Fe(α, n) and 58 Ni(α, p) reactions, and stellar reaction rates have been calculated from them. These have been compared to recent theoretical calculations which used compound nuclear theory. The calculated values are generally higher than the experimental values by factors ranging from 2 to 10.
Requirements for catalysis in mammalian glycogenin.

Abstract Glycogenin is a glycosyltransferase that functions as the autocatalytic initiator for the synthesis of glycogen in eukaryotic organisms. Prior structural work identified the determinants responsible for the recognition and binding of UDP-glucose and the catalytic manganese ion and implicated two aspartic acid residues in the reaction mechanism for self-glucosylation. We examined the effects of substituting asparagine and serine for the aspartic acid residues at positions 159 and 162. We also examined whether the truncation of the protein at residue 270 (Δ270) was compatible with its structural integrity and its functional role as the initiator for glycogen synthesis. The truncated form of the enzyme was indistinguishable from the wild-type enzyme by all measures of activity and could support glycogen accumulation in a glycogenin-deficient yeast strain. Substitution of aspartate 159 by either serine or asparagine eliminated self-glucosylation and reduced trans-glucosylation activity by at least 260-fold but only reduced UDP-glucose hydrolytic activity by 4-14-fold. Substitution of aspartate 162 by either serine or asparagine eliminated self-glucosylation activity and reduced UDP-glucose hydrolytic activity by at least 190-fold. The trans-glucosylation of maltose was reduced to undetectable levels in the asparagine 162 mutant, whereas the serine 162 enzyme showed only an 18-30-fold reduction in its ability to trans-glucosylate maltose. These data support a role for aspartate 162 in the chemical step for the glucosyltransferase reaction and a role for aspartate 159 in binding and activating the acceptor molecule.
Straddling tricuspid valve as a sign of ventriculoatrial malalignment: A morphometric study of 19 postmortem cases.

Abstract Background Straddling tricuspid valve, despite extensive investigation, remains an incompletely understood form of complex congenital heart disease. Methods A morphometric study of 19 postmortem cases of straddling tricuspid valve was performed, and the results were compared with 32 normal control heart specimens. Results In straddling tricuspid valve, marked malalignment of the ventricles was always found relative to the atria. The angle between the ventricular septum and the atrial septum in the short-axis projection averaged 61° ± 24°, the normal ventriculoatrial septal angle averaging 5° ± 2° (P
Modeling Heat Shock Protein Expression Produced by a Heat Wrap

The healing effect of therapeutic hyperthermia induced by widely available heat wrap products is understood to be based on concomitant temperature dependent vasodilation and increase in mass transport. We hypothesize that an additional mechanism of healing associated with increased heat shock protein (HSP) expression is also a contributing factor. HSP expression is controlled by the level and duration of heating and can have a potent effect on healing. We have developed a combined thermal stress and HSP expression model for bioheat transport into the tissues of the back produced by a therapeutic heat wrap. The model predicts temperature distribution in the deep tissues of the back by a modified version of the Pennes (1948, “Analysis of Tissue and Arterial Blood Temperatures in the Resting Human Forearm,” J. Appl. Physiol., 1(2), pp. 93‐122) bioheat equation. The model also predicts HSP70/actin concentrations based on existing empirical expression data from our laboratory as a function of heating time and temperature. Thermal boundary conditions were input for a typical heat wrap worn for its functional duration o f8ho r more. Temperatures in the paraspinal muscles of the back increase by a minimum of 1°C afte r1ho fheating and persist for at least 2 h. HSP70/actin expression is increased 1.7-fold above the control. The model demonstrates that elevated HSP expression may provide an important contribution to the healing process in injured tissue when a therapeutic heat wrap is worn. DOI: 10.1115/1.3143030
A Perspective on the Use of Control Variables to Increase the Efficiency of Monte Carlo Simulations

This is a survey paper on the application of control variables to increase the efficiency of discrete event simulations. The emphasis is on the practical problems and potential of applying the method in the simulation of complex systems. The basic theory of control variables is reviewed and the equivalence of control variables and multiple estimators is discussed. Techniques for generating control variables are described. Inefficiencies resulting from the statistical estimation of control variable coefficients and the problem of confidence interval generation are treated. This is done both within the context of the method of independent replications and the regenerative method. The application literature is reviewed and the conditions under which control variables could be profitably applied in practical simulations are described. Finally, there is a set of recommended directions for future research.
The intra-rater reliability and agreement of compensatory stepping thresholds of healthy subjects

The purpose of this study was to evaluate the test-retest, intra-rater reliability and agreement of compensatory stepping thresholds. A protocol was developed to establish anteroposterior single-stepping thresholds, anteroposterior multiple-stepping thresholds, and lateral single-stepping thresholds. Healthy, young subjects stood on a microprocessor-controlled treadmill, and responded to three series of progressively challenging surface translations. Subjects were instructed to "try not to step" when establishing single-stepping thresholds or "try to take only one step" when establishing multiple-stepping thresholds. Stepping thresholds were defined as the minimum disturbance magnitude that consistently elicited a single or second compensatory step. Thresholds were expressed as the ankle torque necessary to maintain upright posture. Thresholds studied included anterior single-stepping thresholds (τ = 273.0 ± 82.3 N m), posterior single-stepping, thresholds (τ = 235.5 ± 98.0 N m), anterior multiple-stepping thresholds (τ = 977.0 ± 416.3 N m), posterior multiple-stepping thresholds (τ = 701.9 ± 237.5 N m), stability-side lateral single-stepping thresholds (τ = 225.7 ± 77.7 Nm), and mobility-side lateral single-stepping thresholds (τ = 236.8 ± 85.4 N m). Based on intraclass correlation coefficients (ICC) and Bland-Altman plots, all thresholds demonstrated excellent reliability (ICC(2,1) = 0.87-0.97) and agreement. These results suggest that compensatory stepping thresholds have sufficient repeatability to be used in clinical and research-related assessments of fall-risk. Additional study is needed to determine the intra- and inter-rater reliabilities and validity of thresholds specific to the patient populations of interest.
School-Based Risk Assessments: A Conceptual Framework and Model for Professional Practice.

The school-based risk assessment evolved from concerns about the presumed prevalence of children and adolescents willing to plan and commit serious violence at school. This article describes a pragmatic and clinical approach to school violence that addresses both dangerousness and threat assessments. Following a brief review of juvenile crime and the rare instances of school shootings, the article outlines a best-practice approach for school-based risk assessment. It explores the type of youngsters seen in these evaluations and stresses case management over predictive accuracy. With few exceptions, youths referred for school-based risk assessments need services and support rather than punishment, with interventions aimed at helping them to function more effectively.
Noise in strong laser-atom interactions: Frequency fluctuations and nonexponential correlations

We extend our study of the effects of jump-type noise on laser-atom interactions to frequency-telegraph noise. Such noise can be used as a model of collisional effects, in which the atomic transition frequency randomly jumps, or as a model of finite laser bandwidth effects, in which the laser frequency exhibits random jumps. We show that these two types of frequency noise can be distinguished in light-scattering spectra. We also discuss examples which demonstrate both temporal and spectral motional narrowing, nonexponential correlations, and non-Lorentzian spectra. Its exact solubility in finite terms makes the frequency-telegraph noise model an attractive alternative to the white-noise Ornstein-Uhlenbeck frequency noise model which has been previously applied to laser-atom interactions.