cssi/SciSciGPT-SciSciNet huggingface dataset:
Crystallographic Structure of a Rheumatoid Arthritis MHC Susceptibility Allele, HLA-DR1 (DRB1*0101), Complexed with the Immunodominant Determinant of Human Type II Collagen

The expression of HLA-DR1 (DRB1*0101) is associated with an enhanced risk for developing rheumatoid arthritis (RA). To study its function, we have solved the three-dimensional structure of HLA-DR1 complexed with a candidate RA autoantigen, the human type II collagen peptide CII (259-273). Based on these structural data, the CII peptide is anchored by Phe263 at the P1 position and Glu266 at P4. Surprisingly, the Lys at the P2 position appears to play a dual role by participating in peptide binding via interactions with DRB1-His81 and Asn82, and TCR interaction, based on functional assays. The CII peptide is also anchored by the P4 Glu266 residue through an ionic interaction with DRB1-Arg71 and Glu28. Participation of DRB1-Arg71 is significant because it is part of the shared epitope expressed by DR alleles associated with RA susceptibility. Potential anchor residues at P6 and P9 of the CII peptide are both Gly, and the lack of side chains at these positions appears to result in both a narrower binding groove with the peptide protruding out of the groove at this end of the DR1 molecule. From the TCR perspective, the P2-Lys264, P5-Arg267, and P8-Lys270 residues are all oriented away from the binding groove and collectively represent a positive charged interface for CII-specific TCR binding. Comparison of the DR1-CII structure to a DR1-hemagglutinin peptide structure revealed that the binding of these two peptides generates significantly different interfaces for the interaction with their respective Ag-specific TCRs.
Observations of pre-flare activity with TRACE and Yohkoh

Many theories and observations appear to indicate that a simple bipolar structure with strong shearing along the neutral line can produce a coronal mass ejection (i.e. “tether cutting”). The “breakout reconnection” model, in contrast, states that multi-polar magnetic fields are necessary for a CME. Here I briefly review TRACE and Yohkoh observations related to these two competing views on the amount of magnetic complexity needed for a coronal mass ejection.
Development of an active haptic cane for gait rehabilitation

This research aims to develop a novel gait assistive device with enhanced gait stability and training efficiency for stroke patients. The proposed assistive device for mobility aid is composed of a motored wheel and a cane for providing only a light grip force, which prevent a patient using excessive support force of an upper limb like a conventional cane and motivate the patient to use more actively a paralyzed limb due to the reduced weight support. In addition, the proposed device can provide the user with intuitive and safe interaction during walking by integrating an F/T sensor and a tilt sensor at the cane, and a switch sensor at the hand grip. Also, admittance control has been implemented for a patient, it intuitively changes cane speed by measuring interaction forces at the hand grip. A hemi-paretic stroke patient participated in the walking experiments as a pilot study to verify effectiveness of the proposed system. The results showed that the patient could improve walking speed and muscle activation during experiments with a constant speed mode of the haptic cane. Moreover, in the admittance control mode of the haptic cane, the patient could keep higher preferred walking speed and higher gait stability regardless of magnitude of resistance forces. The proposed gait assistive device with cheap, compact and easy-to-use characteristics can provide efficient gait training modes to chronic stroke patients.
Functional comparison of the basic domains of the Tat proteins of human immunodeficiency virus types 1 and 2 in trans activation.

Abstract The trans-activator Tat proteins coded by human immunodeficiency virus type 1 (HIV-1) and HIV-2 appear to be similar in structure and function. However, the Tat protein of HIV-2 (Tat2) activates the HIV-1 long terminal repeat (LTR) less efficiently than Tat1 (M. Emerman, M. Guyader, L. Montagnier, D. Baltimore, and M. A. Muesing, EMBO J. 6:3755-3760, 1987). To determine the functional domain of Tat2 which contributes to this incomplete reciprocity, we have carried out domain substitution between Tat1 and Tat2 by exchanging the basic domains involved in Tat interaction with its target trans-activation-response (TAR) RNA structure. Our results indicate that Tat1 proteins containing substitutions of either 8 or 14 amino acids of the basic domain of Tat2 exhibited reduced trans activation of the HIV-1 LTR by about 1/20 or one-fourth the level induced by wt Tat1. In contrast, Tat2 containing a substitution of the 9-amino-acid basic domain of Tat1 trans activated HIV-1 LTR like native Tat1. A substitution of the highly conserved core domain of Tat2 with that of Tat1 did not have any significant effect on trans activation of the HIV-1 LTR. These results indicate that the basic domain of Tat2 contributes to its inefficient trans activation of the HIV-1 LTR. Mutation of an acidic residue (Glu) located between the core domain and the Arg-rich basic domain of Tat2 at position 77 to a Gly residue increased the activity of Tat2 substantially. These results further suggest that the presence of an acidic residue (Glu) adjacent to Arg-rich sequences may at least partially contribute to the reduced activity of the Tat2 basic domain.
ASSESSING UNIT-PRICE RELATED REMIFENTANIL CHOICE IN RHESUS MONKEYS

Given a commodity available at different prices, a unit-price account of choice predicts preference for the cheaper alternative. This experiment determined if rhesus monkeys preferred remifentanil (an ultra-short-acting micro-opioid agonist) delivered at a lower unit price over a higher-priced remifentanil alternative (Phases 1 and 3). Choice between equal-priced alternatives also was assessed (Phase 2). A discrete-trials procedure was arranged in which three monkeys chose between two remifentanil alternatives by responding on one of two levers. Different prices were arranged by manipulating drug dose (0.3 and 0.1 microg/kg/injection) and/or the ratio requirement. Monkeys usually chose the larger-dose alternative even when it was more expensive. Only when unit prices were relatively high (e.g., large response requirements) did monkeys choose the cheaper (or equally priced) smaller-dose alternative. Employing larger doses (0.9 and 0.3 microg/kg/injection) attenuated the larger-dose preference. The results demonstrate that choice was not determined simply by unit price. An alternative model that employs demand-function analysis to generate choice predictions is proposed.
Pollutant monitoring in the Olympic National Park Biosphere Reserve.

Interest in global contamination has been instrumental in the establishment of over 33 Biosphere Reserves in the United States. These reserves include pristine areas that have been protected from industrial development. They serve as areas in which present and future environmental pollution can be assessed. Pollutant monitoring studies are being conducted in the Olympic National Park Biosphere Reserve by the U.S. Park Service and the U.S. Environmental Protection Agency. Studies are designed to identify levels of trace element and organic contaminants in physical and biological media. Ten remote sites were selected for intensive sampling. These areas were located in the Hoh, Quinault, and Dosewallips River drainages; at Anderson and Grand Pass; near Ozette Lake and, at the northern edge of Blue Glacier. Their proximity to vehicle-traveled roads varied from 3 to 20 kilometers. Samples were taken in air, water, soil, litter and vegetation. Samples will be analyzed for organic and heavy metal contaminants. Airborne particulate size and chemical characterization is being investigated.
Labor market differentials and the expected gain from search

Abstract Several recent empirical studies have used the residuals from estimated earnings equations as explanatory variables in models of on-the-job search and quit behavior. It has often been argued that the coefficients on these “market differential” variables are biased downward because estimated residuals overstate the “true” quasi-rent or disincentive to search for alternative employment. This argument—that observed wages include implicit payments for workplace and person-specific characteristics not fully specified in earnings models— ignores an opposing bias associated with the value of being able to reject unattractive wage offers. As a consequence, there is no unambiguous a priori relationship between estimated wage residuals and the theoretical expected gain from search. Some evidence bearing on the relative magnitudes of the two biases is discussed.
Factorial Structure of the Mach v Scale for Chicano and White College Students

121 Mexican-American and 112 white college students filled out Christie's Mach V scale which measures proclivities for interpersonal manipulation and deceit. Analysis of responses indicated that the Mach V factorial structure was more identifiable for the white students than for the Mexican-Americans. It was concluded that of several possible factorial summaries, a three-factor solution afforded the most succinct reduction of the data.
Study of transport phenomena of FITC labeled dextran through nano self assembled microshells

Abstract The transport characteristics of hollow shells formed via self assembly of polyelectrolytes was the focus of this study. The shells were formed by layering on 5 μm diameter sacrificial cores that were subsequently dissolved in an acidic media. The effect of two polyanions was compared: polyvinyl sulfonate (PVS) and polystyrene sulfonate (PSS) along with two polycations: polyallylamine hydrochloride (PAH), and polydimethyldiallyl ammonium (PDDA). The number of polyelectrolyte bilayers was varied from 2, 4, and 6. The diffusion of fluorescein-isothiocyanate (FITC) labeled dextran was monitored over a period of days after loading times of 12, 36, or 60 h. Loading was also characterized using confocal laser scanning microscopy (CLSM). Two molecular weights of FITC labeled dextran, 4000 and 77,000, were utilized in this study. The choice in polycation results in the largest changes in wall permeability for the neutral pH tested. PDDA architectures produce a higher permeability than PAH structures. Loading of 77,000 MW FITC-dextran was observed in both the PVS/PDDA and PSS/PDDA structures.
Spatial resolution effects on the measurement of scalar variance and scalar gradient in turbulent nonpremixed jet flames

The effect of spatial averaging is important for scalar gradient measurements in turbulent nonpremixed flames, especially when the local dissipation length scale is small. Line imaging of Raman, Rayleigh and CO-LIF is used to investigate the effects of experimental resolution on the scalar variance and radial gradient in the near field of turbulent nonpremixed CH4/H2/N2 jet flames at Reynolds numbers of 15,200 and 22,800 (DLR-A and B) and in piloted CH4/air jet flames at Reynolds numbers of 13,400, 22,400 and 33,600 (Sandia flames C/D/E). The finite spatial resolution effects are studied by applying the Box filter with varying filter widths. The resulting resolution curves for both scalar variance and mean squared-gradient follow nearly the same trends as theoretical curves calculated from the model turbulence kinetic energy spectrum of Pope. The observed collapse of resolution curves of mean squared-gradient for nearly all studied cases implies the shape of the dissipation spectrum is approximately universal. Fluid transport properties are shown to have no effect on the dissipation resolution curve, which implies that the dissipation length scale inferred from the square gradient is equivalent to the length scale for the scalar dissipation rate, which includes the diffusion coefficient. With the Box filter, the required spatial resolution to resolve 98% of the mean dissipation rate is about one−two times of the dissipation cutoff length scale (analogous to the Batchelor scale in turbulent isothermal flows). The effects of resolution on the variances of mixture fraction, temperature, and the inverted Rayleigh signal are also compared. The ratio of the filtered variance to the true variance is shown to depend nearly linearly on the probe resolution. The inverted Rayleigh scattering signal can be used to study the resolution effect on temperature variance even when the Rayleigh scattering cross section is not constant. The experimental results also indicate that these laboratory scale turbulent jet flames have small effective Reynolds numbers, such that there is some direct interaction of the large (energy containing) and small (dissipative) scalar length scales, especially for the near field case at x/d = 7.5 of the piloted Sandia flames C/D/E.
LIM domains: multiple roles as adapters and functional modifiers in protein interactions

The LIM domain is a specialized double-zinc finger motif found in a variety of proteins, in association with domains of divergent functions or forming proteins composed primarily of LIM domains. LIM domains interact specifically with other LIM domains and with many different protein domains. LIM domains are thought to function as protein interaction modules, mediating specific contacts between members of functional complexes and modulating the activity of some of the constituent proteins. Nucleic acid binding by LIM domains, while suggested by structural considerations, remains an unproven possibility. LIM-domain proteins can be nuclear, cytoplasmic, or can shuttle between compartments. Several important LIM proteins are associated with the cytoskeleton, having a role in adhesion-plaque and actin-microfilament organization. Among nuclear LIM proteins, the LIM homeodomain proteins form a major subfamily with important functions in cell lineage determination and pattern formation during animal development.
Review of: Deus in Machina: Religion, Technology, and the Things in Between, by J. Stolow, ed.

New York, NY: Fordham University Press, 354 pp. $95 (hardcover), $28 (paperback).Deus in Machina consists of 11 essays aimed at correcting the supposition that religion and technology are separate ...
Comparison of calculated, measured, and beam sampled impedances of a higher-order-mode-damped rf cavity

Accelerating structures with damped higher-order modes (HOMs) have been the focus of many studies over the past decade. This report compares the results of numerical simulations of damping of HOMs using a new calculation technique applied to the case of the PEP-II rf cavity. We compare these results using this technique, which was not yet developed at the time of the original design, with bench and beam-based measurements of the HOM damping. These results show agreement with bench measurements of the shunt impedances of the strongest HOMs as well as measurements of the beam-induced signals on cavities installed in PEP-II.
Every-three-week versus dose dense weekly paclitaxel neoadjuvant chemotherapy for advanced stage ovarian, fallopian tube, and peritoneal cancers

Objectives: The aim of this study was to compare operative data, toxicity, and survival between weekly dose dense (ddT) and every 3week (q3wT) paclitaxel given with carboplatin as neoadjuvant chemotherapy (NACT) for advanced ovarian cancer. Methods: We performed a retrospective study of stage III–IV ovarian, fallopian tube, or peritoneal cancers treated with NACT followed by interval cytoreduction from January 2009 to present. Carboplatin (AUC 5-6) was given every 3 weeks with ddT (paclitaxel 80 mg/m) or q3wT (paclitaxel 175 mg/m). Chi-square, Student's t test, Kaplan– Meier method, and log-rank statistics were used. Results: Eleven women treated with ddT, and 51 women treated with NACT met inclusion criteria. There were no demographic differences. Median agewas 64. Fifty-nine percent of patients had stage IIIC and 41% stage IVdisease. Therewas nodifference inmean cycles of NACT (3.6 for ddT v. 3.8 q3wT), proportion achieving a 50% decline in CA-125 (91% of ddT v. 94% of q3wT p= 0.51), or radiologic response (100% ddT v. 72% q3wT, p = 0.12). Ten ddT women (91%) and 28 q3wT women (55%) had no gross residual disease after interval cytoreduction (OR 8.21, 95% CI 0.98–69). Mean operative time (181 min ddT v. 166 min q3wT, p = 0.46), EBL (416 cc ddT v. 358 cc q3wT, p = 0.49), and rate of postoperative complications (9% ddT v. 18% q3wT, p = 0.43) were similar. Eighty-two percent of ddT v. 51% q3wT experienced grade 1–2 anemia (p= 0.043) and 55% of ddT v. 14% of q3wT had a grade 1–2 leukopenia or neutropenia (p= 0.029). One ddT patient had grade 3 hypokalemia and one q3wT patient had grade 3 anemia. A similar number of patients in each group was treated with G-CSF (36% ddT v. 55% q3wT, p = 0.26). Median progression-free survival was 16 months for ddT v. 15 months for q3wT, (p= 0.69); overall survival has not been reached. After a median of 15 months, 9% ddT women have died and 27% are alive with the disease. After a median of 21 months, 44% q3wT women have died and 27% are alive with the disease. The remaining patients have no evidence of disease. Conclusion: ddT has similar outcomes with a trend toward increased rate of cytoreduction to no gross residual disease compared to q3wT. Future studies evaluating survival benefit and symptom control between these regimens in the NACT setting are needed.
Surface plasmon resonance biosensor for detection of feline calicivirus, a surrogate for norovirus.

Abstract The human noroviruses are the most common non-bacterial cause of gastroenteritis and are responsible for as much as 50% of all gastroenteritis outbreaks worldwide. Norovirus (NoV), a single stranded RNA virus, is highly contagious with an infectious dose of less than 100 viral particles. While techniques exist for the identification of NoV, the lack of a reliable cell culture system, NoV genetic variability, and time-consuming sample preparation steps required to isolate the virus (or its genome) prior to molecular based methods has hindered rapid virus detection. To better protect the public from virus-contaminated food and enable better detection in clinical and environmental samples, sensitive and selective methods with simple sample preparation are needed. Surface plasmon resonance (SPR) biosensors represent an emerging detection platform, and this approach has been applied to the rapid detection of foodborne small molecule toxins, protein toxins, and bacteria. This analytical technique, however, has yet to be fully investigated for rapid virus detection, especially for intact viral particles extracted from food matrices. For this study, the culturable, non-human pathogen feline calicivirus (FCV), which has similar morphology and is genetically related to NoV, was chosen as a surrogate virus for designing and evaluating an SPR assay. An antibody-based assay was performed by first immobilizing anti-FCV to an SPR chip surface and then directly measuring virus binding and subsequent secondary antibody binding. The resulting biosensor directly detected intact FCV particles with limits of detection of approximately 10 4 TCID 50 FCV/mL from purified cell culture lysates. In addition, intact virus detection in FCV-spiked oyster matrix was possible when using a simple extraction procedure and employing a secondary antibody to FCV for quantitation. The results from these preliminary studies show promise for the development of a rapid assay for detecting intact viruses, such as NoV, using an SPR biosensor. While the current level of sensitivity achieved with this SPR biosensor may be more applicable to virus detection in clinical specimens, broader application and increased sensitivity of this method for foodborne viruses may be achieved when performed in conjunction with efficient virus extraction and concentration methods.
Rho-omega mixing and the pion form factor in the timelike region

We determine the magnitude, phase, and $s$ dependence of $\ensuremath{\rho}$-$\ensuremath{\omega}$ ``mixing'' in the pion form factor in the timelike region through fits to ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ data. The associated systematic errors in these quantities, arising from the functional form used to fit the $\ensuremath{\rho}$ resonance, are small. The systematic errors in the $\ensuremath{\rho}$ mass and width, however, are larger than previously estimated.
Entrainment in cumulus clouds. II: Drop size variability

A new analysis method for examining the effects of entrained subsaturated air on cloud drop sizes is described. This, independently, gives information about height changes following dilution with subsaturated air, and hence about whether the cloud parcels received the subsaturated air when higher or lower than their present level. The physical details of the entrainment mechanisms are first discussed to provide a basis for interpreting the data. Drop-size distributions, measured by a Forward Scattering Spectrometer Probe and obtained from aircraft cloud samples at constant altitude in convective clouds in Montana, are used to analyse these cloud processes. The volume averaged drop radii for each parcel (i.e. each measured spectrum), in several clouds for several horizontal traverses in each, are plotted against concentration, given here in the form of drop numbers per unit mass of air. This concentration from parcel to parcel depends on the fraction of subsaturated air which has been entrained. The entity-type entrainment mixing mechanism provides a satisfactory explanation for all the examples found in this study, where the average drop radius changes very little with drop-number concentration from parcel to parcel. Alternative mechanisms are discussed and found to be insufficient.
New syntheses of per-N-alkyl-substituted triaza- and tetraaza-crovm compounds containing an allyloxymethyl substituent

Seven new per-N-alkyl-substituted triaza- and tetraaza-crovm compounds have been prepared using commercially available or easily synthesized per-N-alkyl-substituted oligoethylene and oligopropylene polyamines, tetraazapentaethylene and tetraazaheptaethylene glycols. Five of these new polyaza-crowns have a pendant allyloxymethyl substituent.
Heme Distortions in Sperm-Whale Carbonmonoxy Myoglobin: Correlations between Rotational Strengths and Heme Distortions in MD-Generated Structures

The authors have investigated the effects of heme rotational isomerism in sperm-whale carbonmonoxy myoglobin using computational techniques. Several molecular dynamics simulations have been performed for the two rotational isomers A and B, which are related by a 180{degree} rotation around the {alpha}-{gamma} axis of the heme, of sperm-whale carbonmonoxy myoglobin in water. Both neutron diffraction and NMR structures were used as starting structures. In the absence of an experimental structure, the structure of isomer B was generated by rotating the heme in the structure of isomer A. Distortions of the heme from planarity were characterized by normal coordinate structural decomposition and by the angle of twist of the pyrrole rings from the heme plane. The heme distortions of the neutron diffraction structure were conserved in the MD trajectories, but in the NMR-based trajectories, where the heme distortions are less well defined, they differ from the original heme deformations. The protein matrix induced similar distortions on the heroes in orientations A and B. The results suggest that the binding site prefers a particular macrocycle conformation, and a 180{degree} rotation of the heme does not significantly alter the protein's preference for this conformation. The intrinsic rotational strengths of the two Soret transitions, separated according to their polarization in the heme plane, show strong correlations with the ruf-deformation and the average twist angle of the pyrrole rings. The total rotational strength, which includes contributions from the chromophores in the protein, shows a weaker correlation with heme distortions.
Modeling T Tauri Winds from He I λ10830 Profiles

The high opacity of He I λ10830 makes it an exceptionally sensitive probe of the inner wind geometry of accreting T Tauri stars. In this line, blueshifted absorption below the continuum results from simple scattering of stellar photons, a situation that is readily modeled without definite knowledge of the physical conditions and recourse to multilevel radiative transfer. We present theoretical line profiles for scattering in two possible wind geometries, a disk wind and a wind emerging radially from the star, and compare them to observed He I λ10830 profiles from a survey of classical T Tauri stars. The comparison indicates that subcontinuum blueshifted absorption is characteristic of disk winds in ~30% of the stars and of stellar winds in ~40%. We further conclude that for many stars the emission profile of helium likely arises in stellar winds, increasing the fraction of accreting stars inferred to have accretion-powered stellar winds to ~60%. Stars with the highest disk accretion rates are more likely to have stellar wind than disk wind signatures and less likely to have redshifted absorption from magnetospheric funnel flows. This suggests the possibility that when accretion rates are high, disks can extend closer to the star, magnetospheric accretion zones can be reduced in size, and conditions can arise that favor radially outflowing stellar winds.
Translating multilevel theory into multilevel research: challenges and opportunities for understanding the social determinants of psychiatric disorders

Introduction The observation that features of the social environment, including family, school, and neighborhood characteristics, are associated with individual-level outcomes has spurred the development of dozens of multilevel or ecological theoretical frameworks in epidemiology, public health, psychology, and sociology, among other disciplines. Despite the widespread use of such theories in etiological, intervention, and policy studies, challenges remain in bridging multilevel theory and empirical research.
Influence of Salt Stress on Growth and Essential Oil Production in Peppermint, Pennyroyal, and Apple Mint

ABSTRACT The effect of salt stress on the growth and chemical composition of the essential oils of peppermint (Mentha x piperita L.), pennyroyal (Mentha pulegium L.) and apple mint (Mentha suaveolens Ehrh.) was investigated. Plantings in a greenhouse were irrigated with full-strength Hoaglund's solution containing 0, 1.5, 3.0, or 4.5 g/L− 1 of NaCl for 74 days. Under salt stress, reduced growth was observed in all three species, although differences in sensitivity to the stress were noted. The fresh weight of apple mint was reduced more, as compared with respective untreated controls, than the other tested species at all the tested salinity levels. Essential oil yields per plant under salt stress were reduced in all three species, as compared with untreated controls not under salt stress. The lower oil yields were a function of smaller plant size and, for peppermint and apple mint, the lower concentration of oil within the tissue as compared with untreated controls. In pennyroyal, the oil concentration in...
Renal medullary hypertonicity and the pathogenesis of acute renal failure.

Des rats furent proteges d'une insuffisance renal aIgue par une diurese aqueuse chronique plutOt qu'intense. L'hypotonicite de la moelle renale est consideree comme un facteur significatif dans le developpement de la deterioration renale.
Electrokinetic Flow Instability in High Concentration Gradient Microflows

This paper documents the scalar imaging of an electrokinetic flow instability that is directly relevant to microfluidic systems that aim to handle and analyze heterogeneous sample streams. The instability occurs in simple T-junctions where two streams of different ionic concentration flow into a common channel. Using neutral dye visualizations, general qualitative behavior of the instability is documented including the formation of a wave in the stream/stream material line that originates at the junction of the two channels and propagates downstream. Several quantitative properties of this phenomenon are measured including wave speed and the extent of the perturbation boundary. This work is part of an ongoing project to identify the physics of this instability and determine the regime of stability, with an ultimate goal of developing methods to either enhance or suppress the instability.Copyright © 2002 by ASME
Wolfhart Pannenberg's Doctrine of the Trinity

In the past some of Wolfhart Pannenberg's interpreters have suggested that a major weakness of his revision of the doctrine of God is a neglect of the doctrine of the Trinity. In 1975 Herbert Burhenn criticised Pannenberg for exercising considerable reservation with regard to the three-in-oneness of God and for reducing the trinitarian distinctions of Father, Son, and Holy Spirit to temporal distinctions. He also stated that ‘The Trinity cannot function for Pannenberg, as it does for Barth, as a structural principle of theology.’ About a decade later Elizabeth Johnson very cogently noted the need for a well-developed concept of the Trinity in Pannenberg's theology:
The management of life-threatening hyperammonemia: A comparison of several therapeutic modalities

THE DEVASTATING central nervous @stem effects of marked hyperammonemia are most clearly evident in congenital defects in the activity of each of the five urea cycle enzymes, the most common of which is ornithine transcarbamylase deficiency? Recent advances in the dietary management of patients with these hyperammonemic syndromes have been demonstrated to prolong or preserve life. 2 Further, temporary hyperammonemia has been described in premature infants? Thus treatment of life-threatening hyperammonemia is important since efficient removal of ammonia in a crisis situation, coupled with steps taken to control NH3 reaccumulation, may be life saving. Recently Donn et aP demonstrated the advantages of hemodialysis over exchange transfusion and peritoneal dialysis in the removal of ammonia from a neonate with OCT deficiency. A newborn infant with extreme hyperammonemia due to this enzyme defect provided us the opportunity to compare the relative effectiveness of these treatments, charcoal hemoperfusion, and resin hemoperfusion as means of NH~ removal.
Stochastic analysis of protein-mediated and microRNA-mediated feedback circuits in HIV

Abstract After infecting a CD4 + T cell, Human Immunodeficiency Virus (HIV) can either replicate and kill the cell or enter latency, a dormant state of the virus where viral gene-expression is turned OFF. This cell fate decision between viral replication and latency is controlled by the viral regulatory protein, Tat. This protein is known to activate its own production, creating a positive feedback circuit. Our previous work has shown that a stochastic model of this feedback circuit exhibits bimodal distributions of Tat levels, even though this circuit lacks deterministic bistability. The modes of the distribution correspond to infected cells with high Tat levels (corresponding to viral replication) or no Tat at all (corresponding to HIV latency). Experimental evidence points to an additional positive feedback loop mediated through a microRNA: a host microRNA targets Tat mRNA for degradation and Tat protein blocks synthesis of this microRNA. Here we investigate the interplay between Tat-mediated and microRNA-mediated positive feedback loops using deterministic and stochastic modeling. Our results show that these positive feedbacks together can exhibit deterministic bistability if the microRNA-mRNA interaction is sufficiently strong. Intriguingly, stochastic analysis reveals bimodal distributions for Tat even for parameter regimes where the coupled feedback system is not bistable. In summary, addition of the micro-mediated feedback loop can lead to bimodal Tat levels for wide a range of parameter values, and suggests a role for microRNAs in the viral cell fate decision in vivo.
Microstructure and elastic properties of sintered hydroxyapatite

The paper focuses on the dependence of microstructure and elastic properties of sintered hydroxyapatite on the processing parameters. Several specimens were sintered in conventional furnace at various temperatures. Elastic moduli were measured ultrasonically and information about the microstructure was recovered from these data and then verified by analysis of microphotographs. It was obtained that the average shape of pores becomes more “round” as the sintering temperature increases. That leads, in particular, to higher fracture toughness of the material since the stress concentration near pores is reduced.
Geographic variation in two deep-sea gastropods, Benthonella tenella (Jeffreys) and Benthomangelia antonia (Dall)

Abstract Benthomangelia antonia and Benthonella tenella are the most abundant benthic gastropod species living at continental rise and abyssal depths south of New England, and are widely distributed in the deep sea of the Atlantic. Both species have planktotrophic development with ontogenetic vertical migration and the potential for large-scale dispersal. A multivariate analysis of shell form in the two species revealed only weak population differentiationon bathymetric scales of about a thousand meters and horizontal separation of hundreds of kilometers in the North American Basin. The degree of differentiation is considerably less than that observed in upper bathyal and coastal snails on much smaller spatial scales. Population differentiation in deep-dwelling snails like B. antonia and B. tenella may be constrained by both their potential for gene flow and the more spatially uniform selective regime at great depths. Lower bathyal and especially abyssal regions may not be as conducive to population differentiation in deep-sea snails as the continental slope.
Trellis Exploration Algorithm Aided Precoder Design in Maximizing MIMO Capacity with Limited Feedback

In this paper, a novel precoder design method is proposed for maximizing MIMO capacity. Specifically, under equal power allocation, we employ the trellis exploration algorithm to design the precoding matrix such that the condition number of the resulting effective channel matrix is minimized. Since the trellis exploration algorithm operates on a finite set of phases, the polyphase precoder is first custom designed at the receiver. Then, a small number of bits indicating phase indices of the corresponding precoding matrix is fed back to the transmitter. We show that for a 2 × 2 MIMO, only 8 feedback bits are necessary to achieve desired performance gain. Simulation results demonstrate that the proposed approach outperforms the well-known "water-filling" scheme at high SNR in terms of ergodic capacity.
Purification and Characterization of the Small Subunit of Phage T4 Terminase, gp16, Required for DNA Packaging

Phage T4 terminase is an enzyme that binds to the portal protein of proheads and cuts and packages concatemeric DNA. The T4 terminase is composed of two subunits, gene products (gp) 16 and 17. The role of the small subunit, gp16, in T4 DNA packaging is not well characterized. We developed a new purification procedure to obtain large quantities of purified gp16 from an overexpression vector. The pure protein is found in two molecular weight forms, due to specific C-terminal truncation, displays in vitro packaging activity, and binds but does not hydrolyze ATP. gp16 forms specific oligomers, rings, and side-by-side double rings, as judged by native polyacrylamide gel electrophoresis and scanning transmission electron microscopy measurements. The single ring contains about eight monomers, and the rings have a diameter of about 8 nm with a central hole of about 2 nm. A DNA-binding helix-turn-helix motif close to the N terminus of gp16 is predicted. The oligomers do not bind to DNA, but following denaturation and renaturation in the presence of DNA, binding can be demonstrated by gel shift and filter binding assays. gp16 binds to double-stranded DNA but not single-stranded DNA, and appears to bind preferentially to a gene 16-containing DNA sequence.
Free mobility determination by electrophoresis in polyacrylamide containing agarose at a nonrestrictive concentration

In the determination of the free mobility, related to the surface net charge, by quantitative gel electrophoresis, the previous arbitrary extrapolation of Ferguson plots from the lowest gel concentrations that give a mechanically stable gel to 0% T has recently been replaced by measurement of mobilities across that concentration range, using the addition of 0.5% agarose to polyacrylamide at the various low concentrations in application to a DNA fragment 155 bp in size (Orban, L. et al., in preparation). The present study applies that approach to several proteins and DNA fragments smaller than 1300 bp, using 0.4% agarose in polyacrylamide gels of varying concentration. The intercepts of the plots with the mobility axis provide experimental data by which the free mobility in polyacrylamide gel electrophoresis can be estimated for molecules not significantly retarded in their migration at the agarose concentration admixed to polyacrylamide. Across the gel concentration range below 3% T, in the presence of agarose, the Ferguson plots of proteins and DNA fragments are convex. It was shown by mass spectrometry that this convex curvature of the plots in the mixed polymer is not significantly due to low polymerization efficiency in the concentration range of liquid polyacrylamide (below 3%T).
Collapse and repair of replication forks in Escherichia coli

Single-strand interruptions in a template DNA are likely to cause collapse of replication forks. We propose a model for the repair of collapsed replication forks in Escherichia coli by the RecBCD recombinational pathway. The model gives reasons for the preferential orientation of Chi sites in the E. coli chromosome and accounts for the hyper-rec phenotype of the strains with increased numbers of single-strand interruptions in their DNA. On the basis of the model we offer schemes for various repeat-mediated recombinational events and discuss a mechanism for quasi-conservative DNA replication explaining the recombinational repair-associated mutagenesis.
An ARIMA supply chain model with a generalized ordering policy

Purpose – This paper aims to present a method for production planning that reduces the bullwhip effect.Design/methodology/approach – The methods are derived using ARIMA models of the supply chain.Findings – The resulting techniques produced an order policy that uses inventory or backlog to absorb the random variation in demand, but has immediate response to variation in the forecast level of demand.Research limitations/implications – The limitation of the research is that the optimality of the order policy is based on the assumption that the demand can be modeled using ARIMA models. When this is not the case the method can still be used as a heuristic approach to production smoothing.Practical implications – This paper offers a practical and easy to implement approach to production planning.Originality/value – The paper introduces a generalized order policy and derives optimal production smoothing parameters for that order policy.
Zolmitriptan and human aggression: interaction with alcohol

The serotonin 1B/D (5-HT1B/D) receptor has shown potential as a target for decreasing aggression. The 5-HT1B/D agonist zolmitriptan's ability to reduce aggressive behavior in humans and its interaction with the well-known aggression-enhancing drug alcohol were examined. Our objective was to investigate zolmitriptan's potential to modify human aggression in a laboratory paradigm across a range of alcohol doses. Alcohol has been consistently associated with aggression and violence, thus we hoped to expand current understanding of alcohol's role in aggressive behavior via manipulation of the serotonin (5-HT) system. Eleven social drinkers, seven male, were recruited to participate in a research study lasting 3–4 weeks. Aggression was measured using the point-subtraction aggression paradigm (PSAP), a laboratory model widely used in human aggression studies. Subjects were administered 5-mg zolmitriptan and placebo capsules along with alcohol doses of 0.0, 0.4 and 0.8 g/kg in a within-subject, counterbalanced dosing design. Data were analyzed as the ratio of aggressive/monetary-earning responses, to account for possible changes in overall motor function due to alcohol. There was a significant alcohol by zolmitriptan interaction on the aggressive/monetary response ratio. Specifically, compared to placebo, zolmitriptan decreased the aggressive/monetary ratio at the 0.4- and 0.8-g/kg alcohol doses. A 5-mg dose of zolmitriptan effectively reduced alcohol-related aggression in an acute dosing protocol, demonstrating an interaction of 5-HT and alcohol in human aggressive behavior.
Recent Results from the MAC and MARK II Detectors at PEP

The results presented below come from data taken at PEP by the MARK II and MAC detectors. The MARK II detector is well-known and a description of the detector can be found in Ref. 1. During the 1981 summer shutdown, the MARK II group removed their inner drift chamber and replaced it with a vertex detector. The vertex detector (fully described in Ref. 2) is a high-precision drift chamber which has four layers of axial wires clustered close to the beam axis at an average radius of 11 cm and three layers clustered at an average radius of 31 cm. The chamber construction and operating considerations have been chosen so as to achieve excellent spatial resolution. The chamber routinely achieves a spatial resolution (per layer) of < 100μ and has been successfully incorporated into the detector trigger, software, et cetera. Because of a short in the MARK II coil, all data taken since January 1982 have half the normal magnetic field of 4.5 Kg. Fortunately, the vertex chamber’s impressive resolution all but salvages the lost momentum resolution due to the reduced field. Most of the MARK II data presented herein correspond to 14.5 pb−1 collected prior to the installation of the vertex detector or the short in the magnet. Some results, as noted in the text, are based on additional data with the vertex chamber and the reduced field. The Monte Carlo simulations for this new data incorporate the changes in the detector configuration
Surface airflow around Windless Bight, Ross Island, Antarctica

Ross Island, Antarctica is located along the Transantarctic Mountains and is subjected to a strong southerly mountain-parallel wind regime. Despite this, Windless Bight on the island's southern coast is a region of anomalous calm. The atmospheric boundary layer dynamics that gives rise to this phenomenon is analysed both theoretically and observationally. It is the strong static stability of the boundary layer air encountering the high steep topography of Ross Island, that causes a stagnation zone resulting in the calm conditions of Windless Bight. Direct and proxy observations of boundary layer winds provide a detailed description of airflow around the island. The anomalous (with respect to the synoptic pressure field) but persistent north-easterly winds at Scott Base are due to the deflection of highly stable, low-level air around Hut Point Peninsula. By contrast, the less frequent, strong southerly winds which override the peninsula are associated with the influx of warm maritime air from cyclonic systems to the east. It is inferred that flow of air around the terrain of Ross Island gives rise to locally strong winds; these are responsible for the ice breakout and polynya occurrences in McMurdo Sound. The surface airflow past Ross Island can be modelled by a two-dimensional, steady, frictionless, irrotational, incompressible flow past an obstacle, with a shape based on an island height contour. The flow is assumed to separate from the eastern and western sides of the island and form a wake downstream. A solution for this flow is presented, based on potential theory for streaming motion past an obstacle. The streamline and isobar patterns clearly depict the stagnation region in Windless Bight. For approaching winds of 20 ms−1 the local pressure field is perturbed by several millibars.
Ten “Laws” concerning patterns of change in the history of mathematics

Abstract Using the new historiography of science as a touch-stone, the historiography of mathematics is examined. Ten “laws” concerning patterns of conceptual change in mathematics are then suggested.
Trace Element (Se, As, Mo, B) Contamination of Evaporites in Hypersaline Agricultural Evaporation Ponds

Disposal of saline drainage waters containing elevated concentrations of the trace elements Se, As, B, and Mo poses a severe environmental hazard in the western part of the San Joaquin Valley of California. This study investigated the partitioning of these trace elements into evaporite minerals formed in agricultural evaporation ponds to determine trace element behavior during the evaporite formation stage and to provide information for development of management strategies to minimize environmental hazards. The trace elements were largely excluded from the evaporite minerals (∼100 times depleted relative to the solution phase), resulting in comparatively low trace element concentrations in these minerals. The affinity of trace element partitioning to the solid phase follows: Se B > As Mo. No differences in trace element partitioning were evident between summer and winter seasons, the type of evaporite formed, or whether the evaporites were collected wet or dry. Since trace elements accumulate in the solution phase, highly evapoconcentrated waters may exceed threshold levels for hazardous waste classification. Isolating these trace element-rich solutions during the latter stages of evapoconcentration into specialized treatment and handling facilities may provide an effective management strategy that minimizes both exposure to waterfowl and the amount of hazardous solid waste generated.
Tenascin-C Is Expressed in Macrophage-Rich Human Coronary Atherosclerotic Plaque

Background Tenascin is a large extracellular matrix glycoprotein generally found in adult tissues undergoing active remodeling such as healing wounds and tumors. To determine the potential role of tenascin-C (TN-C) in the pathophysiology of atherosclerosis, we investigated the pattern of expression of TN-C in human coronary atherosclerotic plaques. Methods and results Immunohistochemical staining and in situ hybridization demonstrated minimal and random expression of TN-C in fibrotic but lipid-poor atherosclerotic plaques. In contrast, all plaques with an organized lipid core or ruptured intimal surface strongly expressed TN-C, which was preferentially concentrated around the lipid core, shoulder regions, and ruptured area of the plaques but not in the fibrous cap. TN-C was not detected in normal arterial tissue. To identify the cellular source of TN-C, the plaques were stained with smooth muscle cell- and macrophage-specific antibodies. TN-C expression correlated with the infiltration of macrophages. Northern blot and immunoprecipitation analysis showed that macrophages expressed 7. 0-kb TN-C mRNA and 220-kDa protein. Reverse transcription-polymerase chain reaction of total RNA derived from macrophages showed that they express the small isoform of TN-C. Zymogram analysis revealed that macrophages markedly increased MMP-9 expression. Conclusions This study demonstrates that the level of TN-C expression correlates with the degree of inflammation present, not with plaque size. In addition, cultured macrophages have the capacity to express the TN-C gene. These findings suggest the significance of macrophages in the remodeling of atherosclerotic plaque matrix composition.
Needs for fundamental atomic reference data: graphite furnaces and transient plasmas

Abstract The needs for fundamental data for analytical spectroscopy using transient atomizers or sources are discussed. It is argued that collision cross-sections and data on surface chemical behavior are needed more urgently than transition probabilities to solve current problems. Data on line shifts, line broadening and plasma ionization potential lowering would also be helpful. Bulk transport properties of non-equilibrium plasmas need to be better understood.