cssi/SciSciGPT-SciSciNet huggingface dataset:
Anxiety in Oral Performance Tests: a Case Study of Indonesian Learners

This study examined anxiety experienced by students before an oral performance test, the relationship between the anxiety and their test performance, and strategies they applied to reduce the anxiety. The participants were 107 Indonesian students who enrolled the English speaking classes. This study revealed that the students did not experience a high level of anxiety before the oral performance test. There was not a very significant relationship between anxiety and their score in the performance test. Finally, some strategies to cope the anxiety were also discussed. Keywords: anxiety, oral performance test, strategies, and scores
Background and Tools

We begin this section by setting up the basic terminology and notation to be used in this book. Then we will discuss briefly the main foundational results and other tools that will be used later. Many of these are taken from IPS, so the proofs will often not be given here. Insofar as possible, we will use the notation from IPS. The first part of this section should be read at the outset. The latter material is more special, and can be read when it comes up later. This material appears in roughly the order in which it is used in the rest of the book.
Passivity of a class of sampled-data systems: application to haptic interfaces

Passivity of systems comprising a continuous time plant and discrete time controller is considered. This topic is motivated by stability considerations arising in the control of robots and force-reflecting human interfaces ("haptic interfaces"). A necessary and sufficient condition for the passivity of a class of sampled-data systems is derived. An example-implementation of a "virtual wall" via a one degree-of-freedom haptic interface-is presented.
The Diversity of AI

This issue of AI Magazine showcases the diversity of AI activities by accompanying its articles with an extensive set of reports on conferences and workshops, as well as with two special features.
Experimental results from an antineutrino detector for cooperative monitoring of nuclear reactors

Our collaboration has designed, installed, and operated a compact antineutrino detector at a nuclear power station, for the purpose of monitoring the power and plutonium content of the reactor core. This paper focuses on the basic properties and performance of the detector. We describe the site, the reactor source, and the detector, and provide data that clearly show the expected antineutrino signal. Our data and experience demonstrate that it is possible to operate a simple, relatively small, antineutrino detector near a reactor, in a non-intrusive and unattended mode for months to years at a time, from outside the reactor containment, with no disruption of day-to-day operations at the reactor site. This unique real-time cooperative monitoring capability may be of interest for the International Atomic Energy Agency (IAEA) reactor safeguards program and similar regimes.
Validation of a Geometry-Based Statistical mmWave Channel Model Using Ray-Tracing Simulation

Next-generation wireless communications systems are expected to exploit frequency bands above 6 GHz. An important transition towards such bands will be design of channel models capable of supporting the design of efficient air-interface and networks. In this paper, we describe a geometry-based statistical channel model and apply ray-tracing simulation for its validation. Focusing on path loss and root-mean-square (RMS) delay spread as metrics, we show that the proposed modeling approach is flexible and realistic.
Kinetics of cross-linking of peptidoglycan in Bacillus megaterium.

Abstract The extent and rate of cross-linking of diaminopimelic acid in the peptidoglycan of Bacillus megaterium have been determined by a new procedure. The method is based on the reaction of nitrous acid with the unprotected amino groups of non-cross-linked diaminopimelic acid. Pulse label experiments in a mutant where diaminopimelic acid is incorporated specifically into peptidoglycan demonstrated that the cross-linking reaction continued for many minutes after incorporation of precursor subunits into peptidoglycan. The method has been used to demonstrate the sensitivity of the cross-linking reaction to penicillin in vivo. Models for assembly of peptidoglyan are discussed.
Globalization, Decentralization, and the Subnational Debt Problem

According to the World Bank, decentralization of government is a pivotal force that will shape global development policy in the 21st Century. Subnational debt restructuring has emerged, however, as one of decentralization's most difficult problems. Financially troubled municipalities face many of the same concerns, for example, as financially troubled nations: holdout creditors can stymie collective attempts at debt restructuring, and reliance on politically-motivated lenders of last resort (the International Monetary Fund in the case of troubled nations, the central government in the case of troubled municipalities) can foster moral hazard. In a recent article, I argued that an international convention for sovereign debt restructuring based on several fundamental principles of bankruptcy reorganization law can effectively address these concerns for nations. In this article, I argue that similar principles can even more easily be applied to the financial problems of subnational governments. To this end, I propose a model law based on these principles that might form the foundation for national laws, informed by local political and legal culture. Then, using the Japanese municipal crisis as an example, I show that countries enacting such a law can prudently and equitably resolve their subnational debt burdens.
Scaling Variable Distributions for Neutrino Proton Interactions in the Fermilab 15-ft. Bubble Chamber with External Muon Identifier

The Fermilab 15-ft. liquid hydrogen bubble chamber was exposed to a one-horn neutrino beam produced by 300 GeV/c protons. Data from 75,000 pictures yielding 343 events after cuts are analyzed here. Previous publications [1] have presented scaling variable (x and y) distribution from these same data analyzed without the use of auxilliary muon identification. These previous results depended upon the use of a purely kinematic method [2] for the identification of the muon in charged current events and thus for the separation of charged current (CC) and neutral current (NC) events. Since there might be important biases and backgrounds in the kinematic selection method, it is important to re-examine the data by means of a different selection method with different, and hopefully smaller, biases. The External Muon Identifier (EMI) mounted on the bubble chamber permits such an analysis.
Comparison of polymerase chain reaction and culture for detection of Borrelia burgdorferi in naturally infected Peromyscus leucopus and experimentally infected C.B-17 scid/scid mice.

Abstract Culture and the polymerase chain reaction (PCR) were compared for detection of Borrelia burgdorferi infection in wild-caught Peromyscus leucopus and experimentally inoculated C.B-17 scid/scid (severe combined immunodeficient) mice. PCR targeted highly conserved regions of the ospA gene and could detect one to five cultured organisms and 10 to 50 copies of molecularly cloned ospA DNA. Organs (kidney, spleen, and urinary bladder) and/or ear biopsy samples were obtained from 108 captured P. leucopus mice, and tissues were obtained from 7 experimentally inoculated mice. A simple sample-processing procedure with proteinase K and detergent treatment was used in the PCR analysis. Overall, B. burgdorferi was detected in 29 of 108 (27%) P. leucopus mice by culture and in 31 of 108 (29%) mice by PCR. As assessed by the kappa statistic, agreement between PCR and culture was high for ear and bladder (kappa = 0.80 and 0.65, respectively) and low for kidney and spleen (kappa = 0.37 and 0.03, respectively). While concordant results were obtained from 98 animals, PCR detected B. burgdorferi from 6 additional mice for which cultures were negative and culture detected B. burgdorferi from 4 animals which were PCR negative. Further phenol-chloroform extraction of DNA in a limited number of samples improved the sensitivity of PCR compared with that of culture. These results indicate that PCR may be as sensitive as culture for detecting B. burgdorferi in ear samples and that PCR analysis is suitable for establishing the infection status of animals in mark-release-recapture studies.
New complexes of peroxidases with hydroxamic acids, hydrazides, and amides.

Abstract Horseradish peroxidase forms spectroscopically distinct, reversible complexes with hydroxamic acids (R─CO─ NHOH), hydrazides (RCO─NHNH2), amides (RCONH2), and α-hydroxyketones (RCO─CH2OH). Binding of these compounds to the enzyme depends on the polar and steric character of R and the hydrogen bonding capacity of ─CO─ X─Y (X─Y = NH─OH, NH─NH2, NH─H, CH2OH). Hydroxamate anions and hydrazide cations do not associate with the enzyme. The dissociation constants (K1) for the enzyme-RCOXY complexes span seven orders of magnitude (K1 ∼ 0.3 to 2 x 10-7 m), the greatest affinity being shown by compounds with a planar, aromatic R group. This is attributed to an interaction of the R moiety at an apoprotein hydrophobic crevice. Spectrophotometric, electron paramagnetic resonance, and magnetic susceptibility measurements indicate that the association of horseradish peroxidase with hydroxamic acids entails a transition from a mixed spin state of the enzyme to a high spin derivative. The spectroscopic characteristics of enzyme-RCOXY complexes are similar, suggesting that X─Y substituents do not interact directly with the metal ion of the prosthetic group but perturb its environment. Analogous conclusions were drawn from (a) the parallelism between RCOXY affinities for manganic and ferric peroxidases which does not pertain to ligands (e.g. F-) substituting in the first coordination sphere of the metal ion and (b) the lack of pronounced spectroscopic changes in RCOXY-ferroperoxidase complexes. The association of peroxidase with hydroxamic acids is competitively inhibited by specific enzyme substrates (hydrogen donors), permitting the evaluation of so far unknown enzyme-(donor) substrate binding parameters (Ks). Such a competitive behavior also implies the proximity of RCOXY to the active site. RCOXY compounds influence heme-linked ionizations and ligand interchange reactions, e.g. they inhibit the formation of alkaline peroxidase and peroxidase-cyanide complex. With cyanide and RCOXY, ferriperoxidase gives tertiary complexes. Their formation occurs sequentially: enzyme (HCN)/⇌ enzyme-cyanide (RCOXY)/⇌ enzyme-cyanide·RCOXY.
Kinematic Analysis, Obstacle Avoidance and Self-localization for a Mobile Robot

This paper presents a novel omni-directional mobile robot with obstacle avoidance and self-location function. Since a special transmission mechanism is designed, we introduce the mechanism design of the mobile robot and analyze its kinematics. A fuzzy-neural control algorithm is presented to realize the obstacle avoidance of the mobile robot. The obstacle avoidance system based on FKCN and the control algorithm for obstacle avoidance are described. A self-localization technique that uses the ceiling light for the landmark is proposed. Using this self-location function, the mobile robot could locate itself in a world coordinate system.
Rethinking the Focus of Heart Failure Quality Measures

By the early 2000s, several landmark trials had demonstrated clear morbidity and mortality benefit for neurohormonal antagonists and vasodilators in patients with heart failure and reduced ejection fraction (HFrEF), including beta-blockers (BB), angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), aldosterone antagonists (AldA), and the combination of hydralazine and isosorbide dinitrate (H-ISDN). These therapies were justifiably assimilated into guidelines for the treatment of patients with HFrEF, but evidence emerged documenting wide variability in compliance with evidence-based therapies and clinical outcomes. 1 At the same time, important studies highlighted that patients started on ACEi and BB while hospitalized for heart failure (HF) were much more likely to remain on these therapies during follow-up than if initiation was deferred to the outpatient setting. 2, 3 Hospital-based interventions to improve compliance with HF therapies suggested clinical benefit with reduced HF readmissions and mortality 4 , and support for this inpatient strategy was buttressed by similar efforts aimed at patients with coronary artery disease. 5
Banking Brain Tumor Specimens Using a University Core Facility

Within the past three decades, the significance of banking human cancer tissue for the advancement of cancer research has grown exponentially. The purpose of this article is to detail our experience in collecting brain tumor specimens in collaboration with the University of Miami/Sylvester Tissue Bank Core Facility (UM-TBCF), to ensure the availability of high-quality samples of central nervous system tumor tissue for research. Successful tissue collection begins with obtaining informed consent from patients following institutional IRB and federal HIPAA guidelines, and it needs a well-trained professional staff and continued maintenance of high ethical standards and record keeping. Since starting in 2011, we have successfully banked 225 brain tumor specimens for research. Thus far, the most common tumor histology identified among those specimens has been glioblastoma (22.1%), followed by meningioma (18.1%). The majority of patients were White, non-Hispanics accounting for 45.1% of the patient population; ...
Structure and expression of germ line immunoglobulin heavy-chain epsilon transcripts: interleukin-4 plus lipopolysaccharide-directed switching to C epsilon.

Abstract We have isolated cDNA clones complementary to a truncated immunoglobulin heavy-chain C epsilon RNA transcript previously found to be induced in B lymphoid cells by treatment with lipopolysaccharide (LPS) combined with interleukin-4 (IL-4). We demonstrate that this transcript initiates from a promoter upstream of the germ line epsilon class-switch recombination region (S epsilon region). The major germ line C epsilon transcript contains a small 5' exon contributed by sequences upstream of the S epsilon region spliced to the normal C epsilon exons. Treatment of splenic B lymphoid cells with LPS plus IL-4 induces the expression of transcripts from the germ line epsilon transcription unit followed by expression of normal immunoglobulin epsilon heavy-chain mRNA. Furthermore, we demonstrate that similar treatment of transformed precursor B cell lines induces the expression of germ line epsilon transcripts followed by class switching to epsilon expression in these lines. This is the first demonstration of switching to epsilon in cells of the pre-B stage. The general structure of the germ line epsilon transcript and transcription unit is similar to that previously characterized for germ line gamma 2b transcripts. However, expression of these two germ line transcription units in B-lineage cells is inversely regulated by IL-4 (plus LPS) treatment, correlating with the effects of these treatments on switching to these loci.
The diameter of bipartite distance-regular graphs

Abstract It is shown that any bipartite distance-regular graph with finite valency k and at least one cycle is finite, with diameter d and girth g satisfying d≤ (k−1)(g−2) 2+1 . In particular, the number of bipartite distance-regular graphs with fixed valency and girth is finite.
Dying Epistemologies: An Analysis of Home Death and its Critique

Within the debate between medical and health geographers there are often calls for methodological and philosophical conciliation. The purpose of this paper is to detail some of the epistemological difficulties in ever achieving that aim. We do so by offering a foundational scientific analysis of home death in Washington State, and then turning to a postmedical deconstruction of that scholarship within the space of a single paper. Although the result is a reflexive self-critical paper on how we know the geography of home death, it is by no means a resolution of the debate. A key epistemological impasse is identified between the foundationalism in our quantitative analysis and our poststructural critique. This impasse leads to different and irreconcilable aims between the two halves of the paper. In our reflections we stress the need to recognize explicitly this epistemological irreconcilability in order to temper the promise of an easy solution to the debate between medical and health geography. We neverth...
THE DEVELOPMENT OF RADIOACTIVE GLASS SURROGATES FOR FALLOUT DEBRIS

The production of glass that emulates fallout is desired by the nuclear forensics community for training and measurement exercises. The composition of nuclear fallout is complex, with widely varying isotopic compositions (Fahey et al., Proc Natl Acad Sci USA 107(47):20207–20212, 2010; Bellucci et al., Anal Chem 85:7588–7593, 2013; Wallace et al., J Radioanal Nucl Chem, 2013; Belloni et al., J Environ Radioact 102:852–862, 2011; Freiling, Science 139:1058–1059, 1963; Science 133:1991–1999, 1961; Bunney and Sam Government Report: Naval Ordinance Laboratory, White Oak, 1971). As the gaseous cloud traverses from hotter to cooler regions of the atmosphere, the processes of condensation and nucleation entrain environmental materials, vaporized nuclear materials and fission products. The elemental and isotopic composition of the fission products is altered due to chemical fractionation (i.e. the fission product composition that would be expected from fission of the original nuclear material is altered by differences in condensation rates of the elements); the fallout may be enriched or depleted in volatile or refractory fission products. This paper describes preliminary work to synthesize, irradiate and fractionate the fission product content of irradiated particulate glass using a thermal distillation 2 h after irradiation. The glass was synthesized using a solution-based polymerization of tetraethyl orthosilicate. (Izrael, Radioactive fallout after nuclear explosions and accidents, 2002) Uranium was incorporated into the glass particulate at trace concentrations during polymerization. The particulate was subjected to a short thermal neutron irradiation then heated to 1,273 K approximately 2 h after the end of irradiation. Fission products of 133, 134, 135I, 132, 134Te, 135Xe, 138Cs and 91, 92Sr were observed to be distilled from the particulate. The results of these preliminary studies are discussed.
Effect of ozone on drug-induced sleeping time in mice pretreated with mixed-function oxidase inducers and inhibitors

Abstract Prior studies have shown that ozone (O 3 ) increases pentobarbital (PEN)-induced sleeping time (S.T.) in female mice, rats, and hamsters. To investigate some potential mechanisms producing these effects, we measured zoxazolamine-induced paralysis time and thiopental- and hexobarbital-induced S.T., all of which were prolonged significantly in mice following a 5-hr exposure to 1960 μg O 3 /m 3 (1 ppm). To probe the effect of O 3 exposure on the drug metabolism microsomal monooxygenase system, CD-1 mice were pretreated with mixed-function oxidase inducers [PEN, phenobarbital, pregnenolone-16α-carbonitrile, and β-naphthoflavone (BNF)] or inhibitors (SKF 525A and piperonyl butoxide) prior to a 5-hr exposure to 1960 μg O 3 /m 3 (1 ppm). In CD-1 mice, pretreatment with PEN caused no effects on PEN-induced S.T. For all other compounds, the PEN-induced S.T. of CD-1 mice was significantly decreased, irrespective of whether the animals were exposed to air or O 3 . Ozone exposure significantly increased PEN-induced S.T. equivalently in the vehicle- and inducer-pretreated animals. Similar studies were conducted in DBA and C57BL mice pretreated with BNF. DBA mice responded similarly to CD-1 mice. However, with C57BL mice, O 3 significantly increased PEN-induced S.T. in the vehicle, but not in the BNF group. When CD-1 mice were pretreated with inhibitors, a generally increased magnitude of the O 3 effect was observed with increasing doses of inhibitor. These data suggest that O 3 exposure may affect several aspects of drug metabolism and distribution.
Modulation of the Regulatory Activity of Bacterial Two-component Systems by SlyA

Activation of the transcriptional regulator SlyA by the PhoP/PhoQ two-component system controls intracellular expression of numerous factors influencing Salmonella virulence. By dissecting the SlyA regulon using stable isotope labeling with amino acids in cell culture analysis, we found that SlyA enhances overall transcription of PhoP-activated loci. This amplification of cellular responses to Mg2+ occurs when SlyA binds to the phoPQ promoter thereby activating phoP autoregulation via a positive feedback mechanism. SlyA footprints a DNA region located one helical turn upstream of the PhoP box, which overlaps the H-NS-binding motif required for signal-dependent phoP repression in high Mg2+ conditions. Therefore, binding of SlyA likely antagonizes H-NS and facilitates the interaction of PhoP to its own promoter, subsequently activating the phoPQ operon. Establishment of this regulatory circuit allows SlyA to exert its effect on the PhoP/PhoQ system specifically in Salmonella, which may confer an additional transcriptional regulation. Thus, our results provide a molecular mechanism that determines SlyA-dependent activation of PhoP-regulated genes in modulating Salmonella virulence. Evidence from this study also suggests a function of SlyA as a mediator in signal transduction from the PhoP/PhoQ system to other bacterial two-component systems in Salmonella.
Too Little, Too Late? The Radiocarbon Chronology of Alaska and the Peopling of the New World

Alaska is commonly viewed as a gateway between the Old and New Worlds, and as such, figures prominently in most models of the peopling of the New World. With a growing number of archaeological sites dating to the terminal Pleistocene, Alaska might be expected to provide direct evidence bearing on the colonization of the Americas. Based on 27 site components with 114 radiocarbon dates, this paper discusses the archaeological record of late Pleistocene Alaska, organized around the characteristics and chronology of three complexes: the microblade-bearing Denali complex, the Nenana complex, and the Mesa complex. This paper shows that the archaeological record of late Pleistocene Alaska is quite diverse, and not lacking in controversy and conflicting interpretations. In addition, this period of archaeological diversity coincides with the Younger Dryas climatic event. However, none of the reliably dated sites is older than the earliest evidence of human occupation further south in the Americas. Despite this, evidence from DNA studies points strongly to a north-central Asian homeland for Native Americans, upholding Alaska as the point of entry into the New World. Suggestions are offered, then, as to why the Alaskan record remains silent about the initial peopling of the New World.
Recreation and Racial Politics in the Young Women's Christian Association of the United States, 1920s–1950s

Founded in the early twentieth century, the Young Women's Christian Association of the United States of America was one of the country's largest independent organizations for women. Unusually cross-class and multi-racial, the group's members, professional staff and volunteer officers frequently debated the YWCA's principles and programmes before mid-century, especially in relation to its segregated black centres. The most contested sites of discrimination were the gymnasium, swimming pool, and summer camp. This essay examines the arguments of advocates and opponents of interracial recreation between the 1920s and 1950s as well as their practical struggles over local policies and reforms. Based on the archival records of the YWCA National Board and nine representative city associations (white and black), the essay demonstrates the important role of voluntary groups and non-professional women in female recreation. More broadly, it explores the volatile politics of race relations, social justice and active b...
A mixed integer programming approach for allocating operating room capacity

We have developed a methodology for allocating operating room capacity to specialties. Our methodology consists of a finite-horizon mixed integer programming (MIP) model which determines a weekly operating room allocation template that minimizes inpatients' cost measured as their length of stay. A number of patient type priority (eg emergency over non-emergency patient) and clinical constraints (eg maximum number of hours allocated to each specialty, surgeon, and staff availability) are included in the formulation. The optimal solution from the analytical model is inputted into a simulation model that captures some of the randomness of the processes (eg surgery time, demand, arrival time, and no-show rate of the outpatients) and non-linearities (eg the MIP assumes proportional allocation of demand satisfaction (output) with room allocation (input)). The simulation model outputs the average length of stay for each specialty and the room utilization. On a case example of a Los Angeles County Hospital, we show how the hospital length of stay pertaining to surgery can be reduced.
Multiphoton Ionization of Nitrobenzene in Non-Aqueous Solutions: Characterization of the Cation and Ion-Molecule Chemistry

The phenoxy cation has been generated in polar and nonpolar solutions by multiphoton ionization of nitrobenzene using nanosecond pulses of 266 nm and 355 nm light. The ions have been characterized by pulsed conductivity (ion mobility) measurements and transient absorption spectroscopy. The involvement of the phenoxy ion in ion-molecule chemistry with either neutral solute or solvent molecules has also been observed and the photochemical products and quantum yields of the ion-molecule products are presented and compared with the neutral photochemistry results.
Relation of Hemodynamic Volume Load to Arterial and Cardiac Size

Abstract Objectives. This study sought to assess the relation of Doppler stroke volume (SV) to cardiac and carotid artery size and to determine whether volume load accounts for the parallelism between the two. Background. It has been suggested that altered hemodynamic volume load can modify the degree and pattern of left ventricular (LV) hypertrophy from that predicted from blood pressure (BP) alone. Methods. We related Doppler echocardiographic SV in 342 normotensive or unmedicated asymptomatic hypertensive adults to echocardiographic LV mass, LV internal dimension (LVID), wall thickness, carotid ultrasound arterial lumen diameter, intimal–medial thickness (IMT) and cross-sectional area (CSA). Results. SV was positively related to LV mass (r = 0.42), LVID (r = 0.45), ventricular wall thickness (r = 0.20 to 0.29) and carotid diameter (r = 0.23, all p Conclusions. SV measured by invasively validated Doppler echocardiography is associated with LV and carotid artery enlargement and eccentric hypertrophy, independent of arterial pressure, LV contractility, age and body size; however, SV and other variables do not account for the previously documented parallelism between cardiac and arterial structure. (J Am Coll Cardiol 1997;29:1303–10)
Paramagnetic Resonance Absorption of Carbazyl and Hydrazyl

The paramagnetic resonance spectra of single crystals of carbazyl and hydrazyl show distinct anisotropies, which appear to be associated with the microscopic magnetic susceptibility within the molecule in the vicinity of the unpaired electron. This leads to an asymmetry in the absorption line of a polycrystalline specimen. The hyperfine structures of the two radicals in a benzene solution show that in carbazyl the two N atoms are nonequivalent in that the odd electron spends approximately twice as long in the vicinity of one, compared to the other.
Anion inclusion within the cavity of π-metalated p-t-butylcalix[5]arene

Abstract The X-ray crystal structure of the triiridium p-t-butylcalix[5]arene host molecule [{Ir(η5-C5Me5)}3(p-t-butylcalix[5]arene-H)][BF4]5 5 reveals the deep inclusion of one of the BF4 anions within the bowl shaped cavity of the macrocycle.
Inhibition of reduced glutathione synthesis by cyanobacterial alkaloid cylindrospermopsin in cultured rat hepatocytes.

Abstract Cylindrospermopsin (CY) is a naturally occurring alkaloid produced by the cyanobacterium Cylindrospermopsis raciborskii, which has been linked to an outbreak of hepatoenteritis in humans. We previously showed that CY is cytotoxic to primary cultures of rat hepatocytes and that CY lowers cell reduced glutathione (GSH) at nontoxic doses. Lower cell GSH also potentiates CY-induced cytotoxicity (Runnegar etal., Biochem Biophys Res Commun201: 235–241, 1994). Our current work examined the mechanism of the fall in cell GSH induced by CY. We excluded several possible explanations for the loss in GSH, namely increased formation of oxidized glutathione (GSSG), increased GSH efflux, hidden forms of GSH, decreased GSH precursor availability, or decreased cellular ATP level. To address whether the fall in GSH was due to decreased GSH synthesis or increased GSH consumption, we examined the rate of fall in total GSH after 5 mM buthionine sulfoximine (BSO, an irreversible inhibitor of GSH synthesis) treatment. The rates of fall in total GSH (nmol/106 cells/hr) were 8.2 ± 2.5, 6.0 ± 1.7 and 5.9 ± 1.3 for control, 2.5 μM and 5 μM CY-pretreated cells, respectively. This suggests that the fall in GSH induced by CY was due to the inhibition of GSH synthesis rather than increased consumption, because in the latter case the rate of fall in GSH would have been accelerated by CY pretreatment. Furthermore, excess GSH precursor (20 mM N-acetylcysteine), which supported GSH synthesis in control cells, did not prevent the fall in GSH or toxicity induced by CY. Treatment of cells with the cytochrome P450 inhibitor α-naphthoflavone protected partially from CY-mediated toxicity and from the fall in cell GSH. Thus, it is likely that cytochrome P450 is involved in the metabolism of CY, and the metabolite(s) that is generated may be more toxic and/or potent in inhibiting GSH synthesis. Inhibition of GSH synthesis is most likely an important factor in the cytotoxicity of CY.
Some further tests of the constant-ratio rule

Five experiments sought to test the constant-ratio rule (CRR) with single dimensional ensembles composed of 2, 4, or 8 stimulus objects. Each S attempted to identify stimuli which varied in weight or in visual size or brightness. The results demonstrated: (a) The CRR predicts equally well the response proportions of single dimensional visual, kinesthetic, and auditory stimulus ensembles, but less well than those for multidimensional auditory stimuli. (b) Better predictions are obtained with four than with two stimulus objects.(c) The CRR is sensitive to variations in the spacing and range of the stimulus ensembles and to practice on the task. It is concluded that the rule tends to fail whenever stimulus conditions elicit differential amounts of stimulus and response confusion.
A comparative evaluation of new fine particle size separation technologies

Abstract The conventional technologies used in industrial operations to achieve fine size separations at 150 μm and below are inefficient. To obtain precise fine size separations, the state of the art fine particle sizing technologies investigated in this study include the newly developed Pansep screen as well as a new design cyclone (gMax TM ) with and without an apex water injection system (Cyclowash TM ). The performance of a Pansep screen having a screening surface area of 0.5 m 2 is evaluated for size separations at 150 μm and 45 μm particle sizes, whereas a 15 cm diameter gMax cyclone with and without a Cyclowash attachment is studied for particle size separation at 45 μm only. The results of this study indicate that the size separation performance obtained by the Pansep screen is significantly better than the performance obtained from conventional technologies such as, cyclone and sieve bend for classifying the minus 1 mm particle size coal slurry at 150 μm. An excellent overall screening efficiency of 98% is obtained from the Pansep screen in comparison to the 44% obtained from the sieve bend and 57% from the raw coal classifying cyclone operating in an Illinois coal preparation plant. For the 45 μm size separation, a conventional cyclone efficiency of 37% is improved to 68% by the gMax cyclone, 70% with the use of Cyclowash attachment and to nearly 99% by the Pansep screening technology. The oversize throughput capacity of the Pansep screen for a particle size separation at 45 μm can be high as 5 ton/h m 2 without any significant negative effect on the overall size separation efficiency. No significant deterioration in the overall screening efficiency is noticed for the particle size separation at 150 μm while obtaining the same oversize throughput indicating the possibility of obtaining higher throughput rates for coarser size separations.
Down-regulation of MHC class I antigen presentation by HCMV; lessons for tumor immunology.

MHC class I antigen presentation is a tightly regulated process that begins in the cell cytoplasm with the generation of peptide ligands by the proteasome (1, 2). Peptides are translocated from the cytosol into the endoplasmic reticulum (ER) lumen through the MHC-encoded TAP complex. These peptides are loaded onto the class I heterodimer that is comprised of a 43 kDa type I membrane glycoprotein heavy chain and a 12 kDa soluble light chain (p2m). Shortly after synthesis of the class I heavy chain and &m, the complex is properly folded with assistance from ER resident chaperones such as calnexin, calreticulin and the thiol-reductase, ERp57(3). Tapasin, an ER-resident protein that associates with TAP, can interact with peptide-free class I heterodimerkhaperone complex and guide it to the TAP, where it is subsequently loaded with peptide. The generation of the trimeric class I complex allows its exit out of the ER and through the Golgi to the cell surface. The major histocompatibility complex (MHC) class I molecules present peptides derived from microbial and cellular proteins on the cell surface (4). The interaction of the MHC class I molecules with cytotoxic CD8'T lymphocytes (CTL) can activate an immune response and target the host cell for lysis, thereby eliminating the infected or abnormal cell. Several viruses and tumor cells can down-regulate the surface expression of class I molecuies at the transcriptional and post-translational levels(5, 6). The prevention of class I surface expression allows these cells to escape CTL detection. The mechanism by which tumors down-regulate class I molecules is not clearly understood. However, viral proteins have been identified which interfere with class I antigen presentation and may provide insight into how class I down-regulation is achieved in tumor cells as well.
INFERRING THE DISTRIBUTIONAL EFFECTS OF BUREAUCRATIC DECISION RULES

Although the bureaucratic decision rules that govern delivery of municipal public services are presumably distributionally benign, they may in fact exert a strong influence on the distribution of urban policy benefits. This article explicates the decision rule governing delivery of two specific types of fire protection services in a small city, measures the distributional inequity characteristic of the patterns of delivery, and infers one or more distributional standards implicit in the decision rule. Statistical analysis using the Index of Inequity indicates that some decision rules incorporate elements of both equality and market standards, while others support need as the distributional standard.
The prevalence of postpartum depression: the relative significance of three social status indices.

Background Little is known about the prevalence of clinically significant postpartum depression in women of varying social status. The purpose of the present study was to examine the prevalence of postpartum depression as a function of three indices of social status: income, education and occupational prestige.
Frozen-in birefringence and anisotropic shrinkage in optical moldings: I. Theory and simulation scheme

An unconditionally stable upwinding scheme was proposed to improve the efficiency of the viscoelastic simulation in molding of optical products using a CV/FEM/FDM technique. A significant computation time saving was achieved due to an elimination of subdivision of the time step as required in the conventional numerical scheme. The approach was applied to simulate the flow-induced birefringence and anisotropic shrinkage in disk moldings using a nonlinear viscoelastic constitutive equation, orientation functions and equation of state. The two-dimensional triangular finite element meshes were used in the disk cavity and the one-dimensional tubular elements were utilized in the delivery system. Good agreement was shown between the simulated pressure traces and flow birefringence in the molding using the unconditionally stable upwinding scheme of the present study and the conventional numerical scheme of the earlier study. In addition, an algorithm for simulation of the thermal stresses and birefringence in moldings using linear viscoelastic and photoviscoelastic constitutive equations was presented by combining constrained and free quenching approaches. The proposed numerical scheme for viscoelastic simulation of injection molding is more suitable for future commercial applications.
Quantum Theory of Many-Particle Systems. I. Physical Interpretations by Means of Density Matrices, Natural Spin-Orbitals, and Convergence Problems in the Method of Configurational Interaction

In order to calculate the average value of a physical quantity containing also many-particle interactions in a system of $N$ antisymmetric particles, a set of generalized density matrices are defined. In order to permit the investigation of the same physical situation in two complementary spaces, the Hermitean density matrix of order $k$ has two sets of indices of each $k$ variables, and it is further antisymmetric in each set of these indices.Every normalizable antisymmetric wave function may be expanded in a series of determinants of order $N$ over all ordered configurations formed from a basic complete set of one-particle functions ${\ensuremath{\psi}}_{k}$, which gives a representation of the wave function and its density matrices also in the discrete $k$-space. The coefficients in an expansion of an eigenfunction to a particular operator may be determined by the variation principle, leading to the ordinary secular equation of the method of configurational interaction. It is shown that the first-order density matrix may be brought to diagonal form, which defines the "natural spin-orbitals" associated with the system. The situation is then partly characterized by the corresponding occupation numbers, which are shown to lie between 0 and 1 and to assume the value 1, only if the corresponding spin-orbital occurs in all configurations necessary for describing the situation. If the system has exactly $N$ spin-orbitals which are fully occupied, the total wave function may be reduced to a single Slater determinant. However, due to the mutual interaction between the particles, this limiting case is never physically realized, but the introduction of natural spin-orbitals leads then instead to a configurational expansion of most rapid convergence.In case the basic set is of finite order $M$, the best choice of this set is determined by a form of extended Hartree-Fock equations. It is shown that, in this case, the natural spin-orbitals approximately fulfill some equations previously proposed by Slater.
Total oesophagogastric dissociation: experience in 2 centres

Abstract Background/Purpose Neurologically impaired (NI) children have an increased incidence of gastroesophageal reflux and many will require surgery. Methods The case notes of 50 NI children who underwent total oesophagogastric dissociation (TOGD) were reviewed. Thirty-four were done as a primary procedure, and 16 were rescues for failed fundoplications. Results There was no operative mortality. Morbidity consisted of 1 subphrenic collection, 1 oesophagojejunal dehiscence and 2 stenoses that responded to dilatation, and 2 bowel obstructions. In 1 case, partial gastric resection was needed because of transhiatal herniation of stomach. Gastrostomy feeding was established by 3 to 5 days. The mean hospital stay was 10.9 days. At 4 months to11 years of follow-up, there was no recurrence of reflux. Children who could swallow enjoyed oral feeds. Their general health and weight SD scores improved. Food aspiration, chest infections, and hospitalizations were reduced, with an improvement in quality of life. There were 5 late deaths in the "primary" and 7 in the "rescue" group from deterioration in their original condition. Conclusion Total oesophagogastric dissociation is a safe and versatile procedure without immediate mortality and limited surgery-related morbidity. Review of our practice suggests TOGD should be considered as a primary procedure in severely NI children with gastroesophageal reflux and significant oropharyngeal incoordination and dependence on enteral tube feeding. Rescue TOGD carries a greater morbidity because of previous surgery with consequent difficult dissection, poor oesophageal tissue, and higher incidence of vagal nerve injury.
Pressure prediction in the Bullwinkle Basin through petrophysics and flow modeling (Green Canyon 65, Gulf of Mexico)

Reservoir pressures within the Bullwinkle minibasin (Green Canyon 65, Gulf of Mexico continental slope) increase at a hydrostatic gradient whereas pressures predicted from porosity within mudstones bounding these reservoirs increase at a lithostatic gradient: they are equal at a depth 1/3 of the way down from the crest of the structure. Two- and three-dimensional steady-state flow models demonstrate that bowl-shaped structures will have lower pressures than equivalent two-dimensional structures and that if a low permeability salt layer underlies the basin, the pressure is reduced. We conclude that at Bullwinkle, pressure is reduced due to an underlying salt body and the bowl-shape of the basin. A geometric approach to predict sandstone pressure is to assume that the reservoir pressure equals the area-weighted average of the mudstone pressure. When the mudstone pressure gradient is constant, as at Bullwinkle, the reservoir pressure equals the mudstone pressure at the average depth (centroid) of the reservoir.
The introduction of dated observations and precise measurement in Greek astronomy

It is a commonplace that a characteristic feature of scientific astronomy is the use of precise positional data observed at specified moments in time. Thus, it is surprising that there has been little discussion regarding the introduction of such data in Greek astronomy. While much is now known about the Babylonian observational texts with their dated reports that may go back to as early as the 8th century bc [cf. Sachs & Hunger 1988], we still lack an account for the introduction and use of such information in the Greek world. Accordingly, our goal here is to review the reports of the earliest Greek astronomical observations that include dates or precise measurement, and to provide a preliminary assessment of their motivation. In the technical literature, the primary source of reports of dated Greek observations prior to Hipparchus (d. after 126:1 cf. Toomer 1978, 207-208) is Ptolemy's Almagest. According to Pedersen [1974, 408-413], Ptolemy mentions a total of 36 such reports [see Table 1 for summary, App. 1 for texts]; but there are, in fact, at most 35, since No. 19 is not an observation at all but a computation by Ptolemy based on No. 18 [see § 3, below]. Moreover, we discount the claims made in Nos. 8 and 16 for observations of summer solstices by the 'Metonians and Euctemonians'2 and the 'Aristarchans'3; and, though it has often been assumed by modern scholars that Nos. 34, 35, and 36 are due to Hipparchus, Toomer [1984, 133n8] rightly notes that there is nothing in the Almagest to support this claim. Consequently, since 13 of the dated observations reported by Ptolemy are Babylonian in origin, this leaves, in our view, a body of 20 technical reports of dated Greek observations before Hipparchus' time.
The Behavior of Ions Inside the Cytoplasmic Domain of Inward Rectifier Potassium Channels

Inward rectifiers are a subfamily of potassium channels that control the amounts of outward K+ current in a cell. These channels achieve rectification through intracellular block by strongly charged cations such as Mg2+ and polyamines like spermine (SPM4+). The large cytoplasmic domain that extends the ion permeation pathway has been shown to be an important determinant of conductance and rectification, however the organization of ions within this part of the pore is not well understood. In this study, the properties of ions inside the cytoplasmic domains of a weak (Kir1.1/ROMK) and strong (Kir2.1/IRK) rectifier are investigated via explicit solvent molecular dynamics simulations in 1M KCl. Both channels concentrate K+ ions in large amounts (local concentration > 3M), with the highest densities near the protein surface. An additional concentrating region specific to Kir2.1/IRK is observed near the cytoplasmic opening. Simulations are also carried out with Mg2+ or SPM4+ inside the domain. Mg2+ interacts directly with pore-lining residues, resulting in a depletion of K+ and increase in the local concentration of Cl−. SPM4+ shows high density throughout the central pore and selectively depletes K+ in the upper region of the pore closest to the transmembrane domain. Two long-lived states of SPM4+ are observed in Kir2.1/IRK: (i) inside the central pore in contact with residues D2591, E2241, E2242 and E2992 from two adjacent subunits, and (ii) near the cytoplasmic entrance interacting with residues D255, D259 and E224 on a single monomer. These results demonstrate a level of molecular specificity with respect to ion behavior within the cytoplasmic domains that could correspond to differences in rectification properties.
A comparison of pretrial and intertriai rewards on runway extinction

In two experiments, rats were trained to run a straight alley for food reward in the goalbox. During subsequent extinction sessions, food rewards were given in the holding cages either immediately pretrial or during the intertriai interval. Pretrial rewards retarded extinction. Importantly, this resistance to extinction was also apparent on nonprefed test trials that occurred either embedded within the daily extinction sessions or at the start of the daily sessions. The results suggest that food reinforcers have a temporary aftereffect that can maintain already conditioned behaviors.
On selecting a measure of retrieval effectiveness part II. Implementation of the philosophy

It was argued in Part I (see JASIS, March-April 1973 p. 87) that the best way to evaluate a retrieval system is, in principle at least, to elicit subjective estimates of the system's utility to its users, quantified in terms of the numbers of utiles (e.g. dollars) they would have been willing to give up in exchange for the privilege of using the system; and a naive methodology was outlined for evaluating retrieval systems on this basis. But the impracticality of the naive evaluation procedure as it stands raises the questions: How can one decide which practical measure is likely to yield results most closely resembling those of the naive methodology? And how can one tell whether the resemblance is close enough to make applying the measure worth while? In the present paper two kinds of solution to these problems are taken up. The first answers the questions in terms of the reasonableness of the simplifying assumptions needed to get from the naive measure to the proposed substitute. The second answers it by experimentation.