cssi/SciSciGPT-SciSciNet huggingface dataset:
What is shaping the coronavirus pandemic in Africa

CONTEXT: The low prevalence of the coronavirus (COVID-19) outbreak in Africa has puzzled many experts. Some have attributed the low prevalence to the continent's inadequate testing capacity, whereas others have suggested other less substantiated evidence such as the preponderance of active global tuberculosis vaccination policies in African countries. Regardless of the true prevalence of COVID-19 in Africa, the pandemic is expected to exhibit a different pattern in Africa compared to other parts of the world because of the continent's peculiarities. AIM: In this article, we discuss the major factors that are currently shaping the pattern and prevalence of the outbreak in Africa. CONCLUSIONS: Based on this assessment, Africa will face an uphill battle against the COVID-19 pandemic with significant long-term effects.
Viral Performance: Contagious Theaters from Modernism to the Digital Age By Miriam Felton-Dansky. Evanston, IL: Northwestern University Press, 2018; pp. ix + 246. $34.95 e-book.

Chapter 1 explores the viral dramaturgy that circulated between Antonin Artaud (among the first to conceptualize theatre as a viral contagion) and the Living Theatre The third viral dramaturgy exploited these via a dramaturgy of "publicly performed fiction - spectacular stories unbounded by theatrical stages" (113) In I Viral Performance: Contagious Theaters from Modernism to the Digital Age i , Miriam Felton-Dansky addresses these problems by way of the concept of "viral performance " [Extracted from the article] Copyright of Theatre Survey is the property of Cambridge University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission However, users may print, download, or email articles for individual use This abstract may be abridged No warranty is given about the accuracy of the copy Users should refer to the original published version of the material for the full abstract (Copyright applies to all Abstracts )
The “So What” of Voice Research

In my tenure as editor, I have offered thoughts and tips on writing for voice research in many of the Editor’s Notes.1 The Voice and Speech Review’s (VSR) mission includes supporting and encouragin...
Linear response of mutans streptococci to increasing frequency of xylitol chewing gum use: a randomized controlled trial [ISRCTN43479664]

Xylitol is a naturally occurring sugar substitute that has been shown to reduce the level of mutans streptococci in plaque and saliva and to reduce tooth decay. It has been suggested that the degree of reduction is dependent on both the amount and the frequency of xylitol consumption. For xylitol to be successfully and cost-effectively used in public health prevention strategies dosing and frequency guidelines should be established. This study determined the reduction in mutans streptococci levels in plaque and unstimulated saliva to increasing frequency of xylitol gum use at a fixed total daily dose of 10.32 g over five weeks. Participants (n = 132) were randomized to either active groups (10.32 g xylitol/day) or a placebo control (9.828 g sorbitol and 0.7 g maltitol/day). All groups chewed 12 pieces of gum per day. The control group chewed 4 times/day and active groups chewed xylitol gum at a frequency of 2 times/day, 3 times/day, or 4 times/day. The 12 gum pieces were evenly divided into the frequency assigned to each group. Plaque and unstimulated saliva samples were taken at baseline and five-weeks and were cultured on modified Mitis Salivarius agar for mutans streptococci enumeration. There were no significant differences in mutans streptococci level among the groups at baseline. At five-weeks, mutans streptococci levels in plaque and unstimulated saliva showed a linear reduction with increasing frequency of xylitol chewing gum use at the constant daily dose. Although the difference observed for the group that chewed xylitol 2 times/day was consistent with the linear model, the difference was not significant. There was a linear reduction in mutans streptococci levels in plaque and saliva with increasing frequency of xylitol gum use at a constant daily dose. Reduction at a consumption frequency of 2 times per day was small and consistent with the linear-response line but was not statistically significant.
Specificity and Evolutionary Divergence of the Antigenic Structure of the Polypeptide Chain Elongation Factors

Antisera have been prepared against two electrophoretically homogeneous "polypeptide chain elongation factors," T and G, from Escherichia coli. Inactivation and precipitation tests showed that these two fractions were antigenically distinct with no cross-reaction. The immune inactivation curve of G factor from E. coli was distinguishable from that of G factor from Pseudomonas fluorescens. Mammalian factors were not inhibited by antibody directed against the E. coli T and G factors. By Ouchterlony diffusion tests, the antisera also detected significant antigenic variability among different bacterial species. It is concluded that the factors have undergone considerable evolutionary divergence in their antigenic structure.
Work in progress: multidisciplinary engineering project abroad

The convergence of scientific and engineering disciplines in current applications requires engineers to have multidisciplinary teamwork skills. This paper describes an international experience that brought together students in engineering, science, social science and the humanities to work on a project that requires technical, foreign language, and research skills. The focus of the experience was to have students work in multidisciplinary teams to develop a chronological map of the city of Cordoba, Spain. They used a geographical information system (GIS) application to develop the map layers, and they constructed Web pages that are linked to the map. This paper summarizes experiences from the first offering in the summer of 2003. We also present planned improvements for the evaluation of the next offering in December 2004.
Speciation and trends of organic nitrogen in southeastern U.S. fine particulate matter (PM2.5)

[1] The impacts of meteorology and air quality on the concentrations and relative distributions of free and combined amino acids (FAA; CAA) are evaluated during a month-long sampling campaign at a semiurban site in the southeastern U.S. The average FAA concentration in fine aerosols (PM2.5) was 11 ± 6 ng m–3, while CAA was found to be several times higher at 46 ± 21 ng m–3. Glycine and alanine were the most abundant amino acids, accounting for 48% of FAA and 58% of the CAA, while distinct differences were observed in compound distributions; glutamic acid, aspartic acid, serine, and threonine accounted for a further 29% of FAA and 30% of the total CAA. An intense rainfall event during the campaign demonstrated the significant impact of meteorological and air quality conditions on FAA-CAA concentrations and distributions. Correlative trends with atmospheric oxidant (ozone) and inorganic nitrogen levels suggest an important role for atmospheric processing. The liquid chromatography-mass spectrometry (quadrupole time-of-flight) technique used in this study allowed for detection of coextracted water-soluble organic compounds and characterization of a larger fraction of the organic nitrogen mass. N-heterocyclic compounds were detected in samples from this campaign, indicating a likely biomass burning source contribution for organic nitrogen.
Hardening at the design level

The problem of hardening against single event upset in integrated circuits can be considered in terms of charge collected by a given device in a given environment. The author focuses on silicon on epi and silicon on buried insulator (SOI) CMOS digital latched and combinatorial circuits operating in a single event environment. >
Static Magnetic Fields

This chapter contains sections titled: Magnetic Force Magnetostatics in Free Space Magnetic Vector Potential The Biot-Savart Law Historical Conclusions Atomic Magnetism Magnetization Equivalent Surface Current Density Equivalent Magnetic Monopole Charge Density Magnetic Field Intensity and Permeability Ferromagnetism Boundary Conditions for Magnetic Fields Inductance and Inductors Torque and Energy
A computational strategy for the solution of large linear inverse problems in geophysics

This paper discusses the use of singular values and singular vectors in the solution of large inverse problems that arise in the study of physical models for the internal structure of the Earth. In this study, the Earth is discretized into layers and the layers into cells, and travel times of sound waves generated by earthquakes are used to construct the corresponding physical models. The underlying numerical models lead to sparse matrices with dimensions up to 1.3/spl times/10/sup 6/-by-3/spl times/10/sup 5/. Singular values and singular vectors of these matrices are then computed and used in the solution of the associated inverse problems and also to estimate uncertainties. The paper outlines the formulation adopted to model the Earth and the strategy employed to compute singular values and singular vectors, shows results for two models that have been studied, comments on the main computation issues related to the solution of these problems on high performance parallel computers, and discusses future improvements of the adopted computational strategy.
The pre-operative anaesthetic visit. Its value to the patient and the anaesthetist.

Summary One hundred and thirty-two patients staying in hospital more than 24 h were visited pre- and postoperatively. Patients were asked a standard set of questions, and 39% could not remember accurately what they were asked. This has important medicolegal implications. In 15% of patients, information that significantly altered subsequent anaesthetic management was discovered, but in less than 3% would ignorance of the patient's condition have required postponement of the surgery. We conclude that the major reason for a pre-operative visit by an anaesthetist is that patients appreciate it, rather than it being medically necessary.
SYNTHESIS AND CHARACTERIZATION OF PROPYL O‐β‐D‐GALACTOPYRANOSYL‐(1→4)‐O‐β‐D‐GALACTOPYRANOSYL‐(1→# 4)‐α‐D‐GALACTOPYRANOSIDE

Allyl 4-O-(4-O-acetyl-2-O-benzoyl-3,6-di-O-benzyl-beta-D-galactopyranosyl)- 2-O-benzoyl-3,6-di-O-benzyl-alpha-D-galactopyranoside was O-deallylated to give the 1-hydroxy derivative, and this was converted into the corresponding 1-O-(N-phenylcarbamoyl) derivative, treatment of which with dry HCl produced the alpha-D-galactopyranosyl chloride. This was converted into the corresponding 2,2,2-trifluoroethanesulfonate, which was coupled to allyl 2-O-benzoyl-3,6-di-O-benzyl-alpha-D-galactopyranoside, to give crystalline allyl 4-O-[4-O-(4-O-acetyl-2-O-benzoyl-3,6-di-O-benzyl- beta-D-galactopyranosyl)-2-O-benzoyl-3,6-di-O-benzyl-beta-D-galactopyran osyl]- 2-O-benzoyl-3,6-di-O-benzyl-alpha-D-galactopyranoside (15) in 85% yield, no trace of the alpha anomer being found. The trisaccharide derivative 15 was de-esterified with 2% KCN in 95% ethanol, and the product O-debenzylated with H2-Pd, to give the unprotected trisaccharide. Alternative sequences are discussed.
System Analysis of the Ciliary Response to Red Light in Chlamydomonas reinhardtii

To understand signal processing networks within cells we study the motile green alga Chlamydomonas reinhardtii. This organism swims with two cilia and has an eye with rhodopsin (peak sensitivity 500 nm, green) controlling the direction of its swimming (phototaxis). Here we report on a red light receptor (peak sensitivity 670 nm) that influences the frequency of ciliary beating, which we monitor by observing a single cell held on a micropipette with a quadrant photodiode. For square-wave on-off stimuli, the recorded beating frequency shows the on-step latency is strongly light intensity dependent, ranging from 700 ms at 1.3 W/m2 to 200 ms at 50 W/m2. This long delay suggests a diffusive step in the signaling pathway and contrasts with the sub-milliseconds latency of green light stimuli. The response amplitude is sustained for the full length of the on-step and is also light intensity dependent. However, the off-step latency seems light independent ranging from 400 to 1600 ms. Following the light off, the beating frequency drops more rapidly and farther the greater the prior light intensity. Products appear to be synthesized in proportion to the light intensity, but once the light is off these products in the cilium run out after about a second. Since the beating frequency is feedback regulated, the red-light elevation of the beating frequency is compensated by a counter molecular change in the cilia. Consequently, when these products run out, there is a rapid declined in beating frequency that takes about 10 s to recover. In addition to steps, sine and white-noise stimuli have been used to refine the response function.
DPI 201-106 for severe congestive heart failure

Abstract DPI 201-106 is a new oral inotropic agent that exerts its effects through a novel mechanism of action, namely, by enhancing sensitivity of myofilaments to calcium and prolonging inward sodium current. In a double-blind, randomized, placebo-controlled fashion, single oral doses (80 and 100 mg) of DPI 201-106 were administered to 15 patients with severe congestive heart failure. Dose-dependent increases in cardiac index (25%, p = 0.016), left ventricular stroke work index (24%, p = 0.018), left ventricular stroke volume index (32%, p = 0.005) and QT c interval (7%, p = 0.009) were observed. Significant effects on heart rate and systemic arterial pressure were not observed. Positive correlations of QT c interval with DPI plasma level (r = 0.64, p = 0.0001), stroke work index (r = 0.47, p = 0.0001) and ventricular ectopic activity on ambulatory electrocardiography (r = 0.49, p = 0.0001) were observed. Maximum changes occurred approximately 3 to 4 hours after ingestion and lasted more than 8 hours. Plasma drug levels were consistent with a 2-compartment model exhibiting first-order absorption and elimination kinetics. DPI 201-106 produced hemodynamic improvement in patients with severe congestive heart failure.
Genetic dissection of diseases: design and methods

The etiology of heritable diseases may be elucidated by localizing genes conferring susceptibility and by subsequent biological characterization of these genes. To localize genetic components for multifactorial traits, both hypothesis-driven candidate gene and hypothesis-free genome scan approaches have been applied. To date, only a handful of results have been reproduced in either a different cohort or model organisms. The integration of genetic approaches with high-throughput genomic techniques is very promising. Unfortunately, most genetic studies completely ignore strong nongenetic effects such as low education and poverty even though these factors are well-known to predict, for example, obesity. Thus, what are most needed in future research are statistical methods for discovering sets of susceptibility genes and environmental factors, as well as systematic verifications of the gene-environment-disease network.
The investigation and management of the infant with ambiguous genitalia: a surgeon's perspective.

ntersexuality comprises a rare but important group of disorders, which usually present at birth with genital ambiguity. The most familiar disorder is congenital adrenal hyperplasia (CAH), about which the pediatrician has a unique perspective regarding the complex management problems these patients often present. The role of the pediatric urologist in these cases is often solely to perform some form of feminizing genitoplasty when such a procedure is deemed appropriate. Among the remaining disorders, which, although individually rare, together make up a substantial proportion of the intersex population, the pediatric urologist brings a particular expertise to bear. This derives from a familiarity with a variety of genital appearances, ranging from female infants with a cloacal or urogenital sinus anomaly to males with hypospadias of varying degrees of severity. Surgeons also have a unique experience of the variability of internal duct and gonadal anatomy as seen at laparotomy or laparoscopy, upon which a definitive diagnosis will often be based. The purpose of this article is to provide a brief overview of normal sexual differentiation and indicate how aberrations along this pathway can lead to genital ambiguity in both the female and the male. A comprehensive classification of intersex disorders is then presented based on gonadal histology, which is both conceptually simple and clinically relevant. In this era of cost containment, a shotgun approach to investigation no longer seems appropriate. Instead, a rational sequence, based on the physical findings, is proposed. Certain conditions with specific surgical implications are then reviewed, and finally, an attempt is made to bring clarity to the present confusion swirling around the question of gender assignment and the place of feminizing genitoplasty among infants to be raised as girls.
Photoelectron spectra of Arn·(IHI)- (n = 0-6, 12, 20), a theoretical study

The effects of the introduction of argon atoms on the photoelectron (PE) spectra of Ar n ·(IHI) - with n = 0-6, 12, and 20 are investigated. Time-independent quantum simulations of the spectra using a rigid cage approximation and allowing the motion of the IHI core are performed. As in our previous classical studies on this system, we find an increase in the confinement of the hydrogen atom motion as the number of argon atoms is increased. Comparison of the quantum and classical descriptions of this confinement provides evidence of the importance of quantum mechanical effects in this system. Three approaches are used to calculate the spectrum of the bare (IHI) - system. Excellent agreement is found between the simulated peaks in the v' 3 = 2 region using a full three-dimensional quantum simulation of the PE spectrum, those from the corresponding experimental threshold photodetachment spectrum and those obtained by employing an adiabatic separation of the motions of the hydrogen and the iodine atoms. This provides further confirmation that these peaks are the result of motions of the iodine atoms. Simulations of the Ar n ·(IHI) - PE spectra show a shift of the spectra to lower electron kinetic energies as the number of argon atoms is increased. Similar shifts are found in the experimental spectra and in our previous study of this system using classical trajectory simulations. It is also found that the I-I motion mainly affects the v' 3 spectrum features, whereas the progressions associated with hindered rotor transitions are less affected. Finally, an increase in the intensity of the v' 3 = 0 peak and an accumulation of transitions in the low-frequency hindered rotor region with increasing number of argon atoms are observed.
A TGFβ-Responsive Gene Signature Is Associated with a Subset of Diffuse Scleroderma with Increased Disease Severity

Systemic sclerosis is a complex disease with widespread skin fibrosis and variable visceral organ involvement. Since transforming growth factor-β (TGFβ) has been implicated in driving fibrosis in systemic sclerosis, a mechanism-derived gene expression signature was used to assay TGFβ-responsive gene expression in the skin of patients with systemic sclerosis (SSc). Primary dermal fibroblasts from patients with diffuse SSc (dSSc) and healthy controls were treated with TGFβ, and the genome-wide gene expression was measured on DNA microarrays over a time course of 24hours. Eight hundred and ninety-four probes representing 674 uniquely annotated genes were identified as TGFβ responsive. Expression of the TGFβ-responsive signature was examined in skin biopsies from 17 dSSc, seven limited SSc (lSSc), three morphea patients, and six healthy controls. The TGFβ-responsive signature was expressed in 10 out of 17 dSSc skin biopsies, but was not found in lSSc, morphea, or healthy control biopsies. Expression of dSSC the TGFβ-responsive signature stratifies patients into two major groups, one of which corresponds to the "diffuse-proliferation" intrinsic subset that showed higher modified Rodnan skin score and a higher likelihood of scleroderma lung disease. The TGFβ-responsive signature is found in only a subset of dSSc patients who could be targeted by specific therapies.
A commentary on high-dose enzyme replacement therapy attenuates cerebroventriculomegaly in a mouse model of mucopolysaccharidosis type II

A commentary on high-dose enzyme replacement therapy attenuates cerebroventriculomegaly in a mouse model of mucopolysaccharidosis type II
Near-infrared resonance Raman excitation profile studies of single-walled carbon nanotube intertube interactions: A direct comparison of bundled and individually dispersed HiPco nanotubes

Complete Raman excitation profiles for single-walled carbon nanotube radial breathing modes were obtained for bundled $\mathrm{HiPco}$ carbon nanotube samples in the region from 700 to $985\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ excitation. Results are compared to similar profiles generated from individual carbon nanotubes dispersed in aqueous solution, allowing a direct determination of intertube interaction effects on electronic properties for 12 specific semiconducting nanotube chiralities. Redshifts in the excitation profiles (ranging from 54 to $157\phantom{\rule{0.3em}{0ex}}\mathrm{meV}$) are observed on going from isolated individual to bundled nanotubes. Additionally, bundling is found to broaden the electronic transitions by an average factor of 2.4 compared to individualized nanotube bandwidths. These results compare well with recent theoretical predictions for bundling effects. An investigation of bundling effects on radial breathing mode frequencies for 17 different nanotube chiralities finds no evidence for significant perturbation of these frequencies resulting from intertube interactions. Our results demonstrate that previously reported radial breathing mode frequency shifts are apparent shifts only, resulting from redshifting of the resonant electronic transitions for bundled nanotubes. Bundle inhomogeneity, packing efficiency, orientational disorder, and symmetry reduction are indicated as important factors in determining the degree of intertube interaction.
AS01-03 - Criticsms of proposed changes in DSM V

Introduction Current diagnositic criteiria for sexual dysfunctions in the ICD 10 and DSM IV have been criticized for their lack of precision and failure to differentiate normal variation in sexual function from disordered sexual behavior requiring medical intervention. Objectives The objective of this presentation is to review the rationale for proposed changes in diagnositc criteria in DSM V. Aims The aims of this presentation are to review proposed changes in diagnositc criteiria for sexual disorders which set severity and duration criteira. Methods Evidence for proposed diagnostic thresholds will be presented. Results Proposed new defintions will incorporate severity (present of 75% of occasions) and duration (present for 6 months) criteria. Conclusions Clinicians have criticized these diagnostic thresholds because many patients seeking treatment for sexual problems will not meet diagnostic criteira. There are no perfect diagnositic thresholds. One always has to balance the risk of false positives (misclassifying normals as ill) versus the risk of false negatives (misclassifying the ill as normal).
Female colour polymorphism in damselflies: failure to reject the null hypothesis

Abstract Abstract. The adaptive significance of colour polymorphisms in adult females within the Odonata remains controversial. Proposed benefits for male-like andromorphs include increased reproductive isolation and/or decreased harassment from conspecific or heterospecific males. Proposed costs balancing such benefits are increased predation on andromorphs, and/or failure of andromorphs to mate at low male densities. Nevertheless, data from past studies are insufficient to reject convincingly the null hypothesis that colour polymorphisms are neutral with respect to natural or sexual selection. Long-term data on two species of Enallagma damselflies are presented that are consistent with the null hypothesis. Male responses to tethered females suggested that males more readily recognize the most abundant morph as 'female'. Nevertheless, the two colour morphs did not differ in the time of day that they were seen in tandem, daily or lifetime mating frequency, life span, oviposition duration, inter-clutch interval, or maturation rate. These results indicated that male discrimination between morphs was predictive of neither costs nor benefits of the polymorphism in terms of female reproductive success.
Mesopheric odd nitrogen enhancements during relativistic electron precipitation events

The behavior of mesospheric odd nitrogen species during and following relativistic and diffuse auroral precipitation events is simulated, Below 75 km nitric oxide is enhanced in proportion to the ion pair production function associated with the electron precipitation and the length of the event. Nitrogen dioxide and nitric acid are also enhanced. At 65 km the percentage of odd nitrogen for N is 0.1%, HNO3 is 1.6%, NO2 is 15%, and NO is 83.3%. Between 75 and 85 km NO is depleted during particle events due to the faster destruction of NO by N relative to the production of NO by N reacting with O2. Recovery of NO depends on transport from the lower thermosphere, where NO is produced in abundant amounts during particle events.
Analytical and finite element solutions of some problems using a viscoplastic model

The feasibility of using a viscoplastic model developed by Robinson to perform a nonlinear structural analysis was investigated. The paper presents analytical solutions for three classical problems: (1) a pressurized thick-walled cylinder, (2) a thin rotating disk, and (3) a pressurized thick-walled sphere. The analytical expressions derived for the stress and the strain rates for these components are general in nature as they consider both the mechanical and thermal loadings to be time-dependent. A computer program VISTAN (VIscoplastic STructural ANalyzer) was developed to obtain the stress and strain distributions. The finite element solutions for these problems are also presented. The numerical results pertaining to isothermal loading conditions are provided. The results obtained demonstrate the feasibility of using the viscoplastic model developed by Robinson to perform nonlinear structural analyses.
A non-natural nucleoside with combined therapeutic and diagnostic activities against leukemia.

Acute lymphoblastic leukemia (ALL) is the most common type of childhood cancer, presenting with approximately 5,000 new cases each year in the United States. An interesting enzyme implicated in this disease is terminal deoxynucleotidyl transferase (TdT), a specialized DNA polymerase involved in V(D)J recombination. TdT is an excellent biomarker for ALL as it is overexpressed in ~90% of ALL patients, and these higher levels correlate with a poor prognosis. These collective features make TdT an attractive target to design new selective anti-cancer agents against ALL. In this report, we evaluate the anti-leukemia activities of two non-natural nucleotides designated 5-nitroindolyl-2′-deoxynucleoside triphosphate (5-NITP) and 3-ethynyl-5-nitroindolyl-2′-deoxynucleoside triphosphate (3-Eth-5-NITP). Using purified TdT, we demonstrate that both non-natural nucleotides are efficiently utilized as TdT substrates. However, 3-Eth-5-NITP is poorly elongated, and this observation validates its activity as a chain-terminator for blunt-end DNA synthesis. Cell based experiments validate that the corresponding non-natural nucleoside produces robust cytostatic and cytotoxic effects against leukemia cells that overexpress TdT. The strategic placement of the ethynyl moiety allows the incorporated nucleoside triphosphate to be selectively tagged with an azide-containing fluorophore via “click” chemistry. This reaction allows the extent of nucleotide incorporation to be quantified such that the anti-cancer effects of the corresponding non-natural nucleoside can be self-assessed. The applications of this novel nucleoside are discussed, focusing on its use as a “theranostic” agent that can improve the accuracy of dosing regimens and accelerate clinical decisions regarding therapeutic intervention.
Use of stable sulfur isotopes to identify sources of sulfate in Rocky Mountain snowpacks

Stable sulfur isotope ratios and major ions in bulk snowpack samples were monitored at a network of 52 highelevation sites along and near the Continental Divide from 1993 to 1999. This information was collected to better de"ne atmospheric deposition to remote areas of the Rocky Mountains and to help identify the major source regions of sulfate in winter deposition. Average annual ! "# S values at individual sites ranged from #4.0 to #8.2! and standard deviations ranged from 0.4 to 1.6! . The chemical composition of all samples was extremely dilute and slightly acidic; average sulfate concentrations ranged from 2.4 to 12.2! eql$% and pH ranged from 4.82 to 5.70. The range of ! "# S values measured in this study indicated that snowpack sulfur in the Rocky Mountains is primarily derived from anthropogenic sources. A nearly linear relation between ! "# S and latitude was observed for sites in New Mexico, Colorado, and southern Wyoming, which indicates that snowpack sulfate in the southern part of the network was derived from two isotopically distinct source regions. Because the major point sources of SO & in the region are coal-"red powerplants, this pattern may re#ect variations in the isotopic composition of coals burned by the plants. The geographic pattern in ! "# S for sites farther to the north in Wyoming and Montana was much less distinct, perhaps re#ecting the paucity of major point sources of SO & in the northern part of the network. Published by Elsevier Science Ltd.
Abundances in Stars from the Red Giant Branch Tip to Near the Main-Sequence Turnoff in M71. III. Abundance Ratios

We present [Fe/H] abundance results that involve a sample of stars with a wide range in luminosity, from luminous giants to stars near the turnoff in a globular cluster. Our sample of 25 stars in M71 includes 10 giant stars more luminous than the RHB, three horizontal branch stars, nine giant stars less luminous than the RHB, and three stars near the turnoff. We analyzed both Fe I and Fe II lines in high-dispersion spectra observed with HIRES at the W. M. Keck Observatory. We find that the [Fe/H] abundances from both Fe I and Fe II lines agree with each other and with earlier determinations. Also the [Fe/H] obtained from Fe I and Fe II lines is constant within the rather small uncertainties for this group of stars over the full range in Teff and luminosity, suggesting that non-LTE effects are negligible in our iron abundance determination. In this globular cluster, there is no difference among the mean [Fe/H] of giant stars located at or above the RHB, RHB stars, giant stars located below the RHB and stars near the turnoff.
Error diffusion coding for A/D conversion

Various novel techniques for A/D conversion of signals subject to a fidelity criterion are presented, leading to optimum digital representations, in which each signal sample is not necessarily quantized to the closest reconstruction level. Quantization is treated as an optimization problem, and the tradeoffs among sampling rate, quantization stepsize, and quantization distortion are examined. It is shown that symmetric neural networks offer a natural means for efficient implementation of the proposed technique. Applications include digital image halftoning, as well as all forms of PCM coding and oversampled A/D conversion. It is shown that concepts and structures used in digital image halftoning are directly applicable to oversampled sigma-delta modulation of sound signals. A novel kind of parallel analog network is introduced and shown to be appropriate for this task. These networks contain a nonmonotonic nonlinearity in lieu of the sigmoid function and perform error diffusion in all directions. Ideas for massively parallel analog VLSI implementation are offered. >
If I only had a whole brain: the importance of extrahypothalamic areas in the energy balance equation.

It seems that the growth in obesity research is matched only by the expansion of worldwide obesity. The literature on obesity-related peptides is overwhelming in size and complexity and offers little in the way of practical solutions. Obesity is seldom due to simple overeating but, rather, to decreased energy expenditure, inactivity, lowered thermogenesis, reduced metabolic rate, misdirected energy partitioning, and the interaction of these factors with diet and other environmental factors. To make matters more complex, energy intake, storage, and expenditure are orchestrated by many parts of the brain and periphery. It is difficult to imagine that most investigators are unaware of this complexity, and so it is surprising that so few of them have actually attempted to measure aspects of energy expenditure (such as oxygen consumption, body temperature, heart rate, vasoconstriction, or expenditure on reproduction or immune function) along with energy intake. Years of research focused on either energy intake or expenditure have left us with many questions about the mechanisms that integrate these aspects of energy balance. Skibicka and Grill in this issue (1) are perhaps taking us in a better direction, demonstrating that a putative satiety peptide also increases core body temperature and heart rate when infused in two different picomolar doses to several different, widely distributed brain sites including areas of the hypothalamus and hindbrain. Remarkably, no strict segregation of function was apparent. The impact of this paper will be great if readers get the message that the brain is organized into a network of areas that display a great deal of redundancy of function, most of which impact aspects of energy intake and expenditure. As the authors point out, progress would be enormously facilitated if this paper discouraged the tendency to examine gene expression in one brain area as a marker for behavioral function, e.g. the arcuate nucleus as evidence for control of feeding.
Effect of temperature on strength and stiffness properties of near-surface mounted FRP reinforcement

Abstract This paper presents results from an experimental study on the effect of temperature on tensile strength and elastic modulus of two types of near-surface mounted (NSM) reinforcement, CFRP strip and CFRP rod, in 20–600 °C temperature range. Results from these tests indicate that both CFRP strip and rod retain most of their initial tensile strength and elastic modulus properties up to 200 °C. However, these properties degrade significantly beyond 300 °C due to decomposition of FRP resin. Further study shows NSM strip and rod possess relatively higher strength than those used for internal reinforcement and external laminates. Data from tests is utilized to propose empirical relations for variation of strength and modulus of NSM CFRP reinforcement with temperature.
Orally administered opioid antagonists reverse both mu and kappa opioid agonist delay of gastrointestinal transit in the guinea pig

Abstract Kappa(κ) opioid agonists slow gastrointestinal transit in the guinea pig and the mouse but not the rat. Opioid antagonists naloxone and naltrexone are mu (μ) preferring, while the antagonist nalmefene has more κ binding activity. When administered orally, the specific opioid antagonists naloxone, naltrexone, and nalmefene are able to reverse the gastrointestinal transit delay caused by orally administered μ and κ opioid agonists (morphine and U-50,488H) in a dose dependent fashion as measured by the leading edge of charcoal meal in the guinea pig. Oral naltrexone and nalmefene have significantly more central nervous system (CNS) bioavailability than oral naloxone. However, orally administered naloxone was as effective as either naltrexone or nalmefene in reversing μ opioid agonist induced orocecal transit delays (single agonist dose apparent ED 50 s = 12.3 ± 4, 7.3 ± 4, and 13.5 ± 6 mg/kg respectively). Nalmefene was more active than either naltrexone or naloxone in its ability to reverse the κ agonist U-50;488H (single agonist dose apparent ED 50 s = 18.3 ± 12 ∗ , 37.5 ± 5, and 61.9 ± 5 mg/kg respectively; ∗ = p ). These data confirm the enteric action of orally administered opioids and further supports our earlier findings of the presence of κ opioid activity in the guinea pig enteric nervous system.
The role of early maternal responsiveness in supporting school-aged cognitive development for children who vary in birth status.

OBJECTIVES. To examine the relation between the pattern of maternal responsiveness that children experienced in the infancy, preschool, and school-age periods and growth in cognitive skills across 3–10 years of age and determine whether the relation differs by birth status. METHODS. In 1990–1992, 360 children varying in birth status (very low birthweight [VLBW]; demographically matched controls) were recruited to examine parenting and birth status influences on development. This report includes children with observations of parenting at 6, 12, and 24 months and 3, 4, 6, 8, and 10 years and cognitive skills evaluated at 3, 4, 6, 8, and 10 years of age (71% of original cohort). RESULTS. Four groups of mothers varying in the pattern of responsiveness displayed across the infancy and the preschool period were found. When controlling for school-age parenting and economic status, children parented with higher levels of responsiveness across both developmental periods, irrespective of birth status, showed higher levels in development than those who experienced responsiveness in only 1 development period or minimal responsiveness. Greater benefit was found for consistency in responsiveness for children born VLBW with less, versus more, severe neonatal complications. Inspection of the means showed that higher risk birth status combined with minimal responsiveness resulted in cognitive scores, on average, 14 points lower than when parented with consistently higher responsiveness. CONCLUSIONS. Cognitive development for children born at VLBW, particularly those with less severe complications, are supported by consistently responsive parenting across early childhood in similar ways to those born at term. This effect persisted through 10 years of age even after school-age parenting and economic level. These findings have important implications for the timing (across early childhood) and content (responsive interactive behaviors) of early intervention to enhance the outcomes for children born at VLBW.
Effect of low-dose methotrexate on the disposition of glucocorticoids and theophylline.

Abstract Low-dose methotrexate (MTX) therapy has been recently proposed as alternative therapy for patients with severe steroid-requiring asthma. Several questions have been raised regarding the mechanism of action, including alteration of pharmacokinetics of two medications used in these patients, specifically, glucocorticoids and theophylline. To address this question, pharmacokinetic studies were performed at baseline and after 6 weeks of treatment with either intramuscular MTX or placebo (folic acid). Plasma concentrations of theophylline were measured by fluorescence polarization immunoassay (TDx, Abbott Diagnostics, Abbott Park, Ill.). Prednisolone, methylprednisolone, and cortisol concentrations were measured by high-performance liquid chromatography. Fifteen adults were enrolled in the double-blind, placebo-controlled trial. No change in prednisolone pharmacokinetic parameters was found. Theophylline clearance decreased an average of 19% in patients randomized to receive MTX, from 48.0 ± 2.0 ml/hr/kg to 38.9 ± 3.6 ml/hr/kg ( p
Carbon isotope enrichment by retention of isotopic excitation selectivity in vv ladder climbing collisions

Initial isotopic excitation selectivity in cw CO2 laser pumping of 12CH3F and 13CH3F is retained in upper vibrational states even after ladder climbing collisions. Reaction of these states with atomic bromine samples this non-equilibrium distribution and produces isotopically enriched product, CH2FBr, with projected excellent energy efficiency.
On-chip voltage regulator without physical inductor

Voltage regulators are at the heart of portable and embedded systems, which demand high-performance and low-power microprocessor design. These regulators will provide best voltage switching and power delivery when they can be integrated on the same chip with the microprocessor. However, their on-chip implementation is challenging because of low power-conversion efficiency and noisy output due to inductive element. Furthermore, inductors are difficult to be implemented on the chip, because they occupy valuable space due to their large size and introduce many parasitic effects. In this paper we investigate several techniques to replace inductors in a voltage regulator. The purpose is to identify the most suitable option to design physical inductor-less regulator. From primary observation it appears that active circuit elements based inductor can replace inductor in on-chip regulator design.
The passage of ascorbic acid across the membrane of the human erythrocyte

Abstract 1. 1. Under controlled conditions in vitro , when the ascorbic acid concentration outside washed erythrocytes ranged between 0 and 4.60 mg./100 ml., there was no evidence that ascorbic acid either moved out of or into the cell. 2. 2. Wide variations in p co 2 and the presence or absence of adrenaline or insulin did not alter, within this range of concentrations, the transfer of ascorbic acid across the cell membrane. 3. 3. In vivo , ascorbic acid moved slowly across the cell membrane. Ascorbic acid passed into the erythrocyte more rapidly than it passed out. 4. 4. The presence of ascorbigen (bound ascorbic acid) in laked whole blood was not confirmed.
Determination of the density of gap states: field effect and surface adsorption

Abstract Can the conductivity, the thermopower or the photoconductivity of an amorphous silicon film be determined? Does the field effect measure the density of gap states? What is the magnitude of the mobility gap? These questions do not have a simple answer. High quality films contain space charge layers adjacent to the substrate interface and near the top surface. These layers can strongly influence the electronic properties of the film, and changes may occur during the course of measurements as charges are exchanged with adsorbates, with the surface oxide or with traps in the insulating substrate. Other causes for change are light, thermal treatments and high transverse electric fields. Attempts to remove or fix these space charges or at least to understand their origin and effects are discussed. The validity of several assumptions needed for interpreting field effect measurements is questioned.
Modeling central bank behavior: What have we learned?

Abstract Within the literature on monetary and fiscal policy there exists a wide range of results on the role and effects of policy, both domestically and internationally. This article focuses on various inadequacies associated with the modeling of central bank behavior as an important source of the disparities. The role of policy procedures and regulations in influencing causal relationships and the dynamic adjustment of the financial system to disturbances is highlighted. At the practical level, the evolution of monetary policy in the United States is reviewed and compared to policy procedures in other major countries, with special emphasis on the implications for empirical studies. Finally, the various ramifications for contemporary policy analysis within the across interdependent nations are explored with an eye towards enhancing the reliability, robustness, and predective power of our models.
Quantitative measurement of density and velocity in compressible flows using laser-induced iodine fluorescence

A nonintrusive optical technique for the quantitative measurement of molecular density and velocity at a point or in an entire cross-sectional plane of a compressible flowfield is reported. Iodine molecules, seeded into the flowfield reservoir, are excited by a tunable narrow-bandwidth laser and the resulting spatially-resolved fluorescence is collected by a single- or multiple-element detector. A theoretical model for the iodine laser-induced fluorescence process is essential for quantitative measurements and is developed using a rate-equation approach. Density measurements using laser-induced fluorescence are normally complicated by collisional quenching; however, the theory predicts that the off-resonant fluorescent signal is directly proportional to density. Velocity is directly related to the Doppler shift of the iodine absorption line, determined by monitoring the broadband fluorescent signal as the laser is tuned in frequency. Experiments in a steady supersonic flowfield are compared with numerical calculations to demonstrate the accuracy of the approach for density and velocity measurement and the lack of perturbation to the flowfield by the iodine seeding. Extensions of the current approach to density and velocity measurement in lower Mach number flows, to the measurement of pressure and temperature, and to temporally-resolved measurements are discussed.
Postoperative analgesia using a low-dose, oral-transdermal clonidine combination: lack of clinical efficacy.

Study Objective To determine if a lower than previously reported oral-transdermal clonidine regimen could reduce postoperative morphine requirements without producing systemic side effects. Design Double-blind, randomized, placebo-controlled study. Setting University-affiliated hospital. Patients 29 healthy, ASA physical status I and II females undergoing elective abdominal hysterectomy. Interventions Patients received preoperative oral clonidine 4 to 5 μ/kg and a 7 cm 2 transdermal clonidine patch (0.2 mg/24 hours) or a placebo tablet and patch. Measurements and Main Results Postoperative patient-controlled analgesia pumps provided morphine during the 48-hour study period. Morphine use, hemodynamic changes, and nonhemodynamic side effects were recorded. Additionally, visual analog pain scales (VAPS) and plasma concentrations of morphine and clonidine were measured. We found that low-dose clonidine had no potentiating effect on morphine analgesia. Postoperative morphine use, VAPS, and morphine plasma levels were similar between the control and clonidine-treated groups. Nevertheless, patients in the clonidine group experienced a significantly greater incidence of intraoperative and postoperative hypotension and brady cardia than did the control group. No differences were noted in the incidence of nonhemodynamic side effects. Conclusions The low-dose oral-transdermal clonidine regimen evaluated failed to reduce postoperative morphine requirements, although patients who received clonidine were still at risk for developing hypotension.
Synthesis of Cephalosporin C from Sulfate by Mutants of Cephalosporium acremonium

The innate ability of Cephalosporium acremonium to use methionine preferentially over sulfate for synthesis of cephalosporin C can be influenced through mutation. Mutants of C. acremonium with altered capacity to utilize sulfate for synthesis of antibiotic were isolated and partially characterized with respect to the uptake of sulfate and the regulation of arylsulfatase.