cssi/SciSciGPT-SciSciNet huggingface dataset:
Midlife African-American women's protective and risky practices related to HIV.

Title. Midlife African-American women’s protective and risky practices related to HIV. Aim. This paper is a report of a study exploring the relationships between social, cultural and individual factors and midlife African-American women’s risk taking and protective practices related to HIV/AIDS. Background. The extent of the HIV epidemic among women of African descent around the world is difficult to discern, but women of color are disproportionately affected. While the risk factors for HIV infection are clearly defined, the context for sexual risk-taking and protective practices is poorly understood for midlife African-American women. Method. The study was guided by grounded theory methods. The Afrocentric Paradigm, Theory of Gender and Power, and Social Cognitive Theory formed the basis for developing semi-structured interview and focus group schedules. Theoretical sampling and principles of emergent design were used to guide data collection and analysis. Interview and focus group data were collected between 2003 and 2006. Transcripts were analyzed using constant comparison to develop descriptive themes, and member checking was used to verify findings. Findings. African-American women (n = 36) who were between the ages of 40 and 64 years and HIV negative volunteered for the study. Participants characterized their sexual decision-making as two conflicting processes –‘Taking Responsibility’ and ‘Getting Caught Up’– related to being accountable for sexual decision-making and having strong sexual desires. Conclusion. Stereotypical views of midlife African-American women must be overcome to ensure that they are treated appropriately in the clinical setting. Increasing emphasis on developing woman-controlled HIV prevention approaches holds the greatest hope for controlling the epidemic among women.
Design of sensor networks for long term monitoring of geological sequestration

Abstract Analysis of geologic sequestration on a wide scale with the aid of integrated assessment models showed earlier that overall leakage rates from the storage sites must be less than 0.1% of stored volume per year if the strategy is to be effective for long term control of atmospheric CO 2 concentrations. Early detection and characterization of a nascent leak significantly increases the probability that a timely solution can be found. Because potential leakage pathways are not necessarily known a priori , monitoring must be done across a region as large as 100 km 2 in the vicinity of a CO 2 injection well, which represents the area of review of the supercritical CO 2 bubble under typical injection scenarios. The relatively high background levels of CO 2 present in the atmosphere and soil, coupled with their seasonal and diurnal modulation, make immediate detection of a small CO 2 leak difficult. Co-injection of tracers during sequestration eliminates the ambiguity and delay in positive identification of a leak. We report here on the design of sensor networks, as a part of the development of a prototypical, field deployable sensor/tracer technology for monitoring the rate of leakage of geologically sequestered CO 2 . The primary focus is on conservative tracer technology for immediate leak detection. In so doing, we are laying a foundation from which reactive tracer technology for pathway characterization can be developed. A semi-analytical model developed earlier for modeling the injection, fate and transport of sequestered CO 2 was adapted for sensor network design. The design simulations are developed to answer several key questions about the sensor network layout. Simulation results indicate that the key parameters governing the monitoring network design are the sensor node spacing ( S ), sampling density D (no. of sensors/km 2 ), minimum detection limit of sensor ( L ), injected tracer concentration ( C o ) and dispersed tracer concentration ( C t ) in the environment. Environmental dispersal modeling shows that C t is a strong function of environmental conditions such as wind velocity. Analysis of the trade-offs indicates that a low detection limit allows effective monitoring with a minimal sensor sampling density and low tracer C o .
Biomass and nitrogen dynamics in an irrigated hybrid poplar plantation

Abstract A 3-year study measured the effects of ground cover treatments and N fertilization on biomass and nitrogen dynamics in an irridiated hybrid poplar (Populus deltoides Bartr. X P. trichocarpa Torr. and Gray, clone NC-9922) plantation in northern Wisconsin, U.S.A. Annually fertilized (112 kg N ha−1 year−1) and unfertilized plots were maintained weed free (bare soil), allowed to revegetate with native weeds, or seeded to birdsfoot trefoil (Lotus corniculatus L.). Biomass and N in trees and ground-cover vegetation were sampled before and after each growing season. Trees in bare-soil plots responded to fertilization primarily in the third growing season, but total biomass of 3-year-old trees was not increased by annual fertilization. In plots with a ground cover,fertilization increased tree growth but cover crop treatment had no effect. Ground cover biomass peaked during the second growing season, but declined thereafter, primarily due to reductions in below-ground biomass. Estimated recovery of fertilizer N was low in bare soil plots after 3 years, with 2% in the ‘perennial’ portion of the trees and 13% in the leaf litter. In contrast, recovery in the cover crop plots was 44%–51% in years 2–4. During that period, both biomass and N pool dominance shifted from primarily cover crop to primarily trees. The ground cover appeared to reduce tree growth in years 1–3, but total tree biomass after 4 years was greater in fertilized plots with ground cover (22.7 Mg/ha) than in fertilized bare soil plots (16.7 Mg/ha). Biomass production in fertilized trefoil plots in the fourth year (15.1 Mg ha−1 year−1, excluding leaves) exceeds that of local forests by 50%, and may be comparable to corn productivity in the area.
Supramammillary area mediates subcortical estrogenic action on hippocampal synaptic plasticity.

Abstract It is well established that systemically administered estrogen to ovariectomized rats positively affects the density of pyramidal cell spines in the hippocampal CA1 subfield and intact subcortical connections of the hippocampus are essential in this hormonal action. This study explored whether local estrogen administration into the supramammillary area influences the density of CA1 pyramidal cell spine synapses in ovariectomized rats. The first group of experiments using a combination of retrograde tracer technique and immunostaining for estrogen receptor-α demonstrated that a large population of supramammillary area estrogen receptor-α-containing neurons projects to the hippocampus. Animals belonging to the second experimental group were ovariectomized and received cannulae filled with 0.4% 17 β-estradiol placed unilaterally into the supramammillary area. Control animals received a cholesterol-containing cannula into the supramammillary area or an estrogen-filled cannula implanted into the head of the caudate nucleus. One week later, rats were killed and CA1 pyramidal cell spine synapse density was determined using electron microscopic unbiased stereological procedures. Animals that received an estrogen-filled cannula into the supramammillary area exhibited a significantly higher (37%) density of CA1 pyramidal cell spine synapses than both other control groups. These observations indicate that the supramammillary area is involved in mediating synaptoplastic, estrogenic effects to the hippocampus.
Selective Requirement of Myosin Light Chain 2v in Embryonic Heart Function

Two major myosin light chain 2 isoforms are coexpressed in the early stages of murine cardiogenesis, a cardiac ventricular isoform and a cardiac atrial isoform, each of which is tightly regulated in a muscle cell-type-specific manner during embryogenesis (Chien, K. R., Zhu, H., Knowlton, K. U., Miller-Hance, W., van Bilsen, M., O'Brien, T. X., and Evans, S. M. (1993) Annu. Rev. Physiol. 55, 77–95). We have disrupted myosin light chain 2v gene in mice and monitored in vivo cardiac function in living myosin light chain 2v −/− embryos. The mutant embryos die at approximately embryonic day 12.5. In mutant ventricles, the myosin light chain 2a protein level is increased and reaches levels comparable to the myosin light chain 2v in the ventricles of wild type littermates and is appropriately incorporated into the thick filaments of mutant embryonic hearts. However, despite the substitution of myosin light chain 2a, ultrastructural analysis revealed defects in sarcomeric assembly and an embryonic form of dilated cardiomyopathy characterized by a significantly reduced left ventricular ejection fraction in mutant embryos compared with wild type littermates. We conclude that myosin light chain 2v may have a unique function in the maintenance of cardiac contractility and ventricular chamber morphogenesis during mammalian cardiogenesis and that a chamber-specific combinatorial code for sarcomeric assembly may exist that ultimately requires myosin light chain 2v in ventricular muscle cells.
Inhibition of Bacterial DNA Replication by 6-(p-Hydroxyphenylazo)-uracil

THE semi-conservative replication of DNA of Gram-positive bacteria is specifically inhibited by 6-(p-hydroxyphenyIazo)-uracil (HPUra; obtained from ICI) in an apparently novel mechanism1–4. We have attempted to characterize the HPUra-sensitive site in replication using in vitro preparations of drug-sensitive bacteria. In particulate and soluble preparations of sensitive bacteria, however, HPUra at high concentration does not significantly inhibit polymerization of deoxyribonucleotides2,4. Since these systems may not accurately represent the process of DNA replication as it occurs in vivo, we have examined the effect of HPUra on a more suitable, toluene-treated preparation of Bacillus subtilis described by Matsushita et al.5. In this preparation, DNA replication is ATP-dependent, utilizes deoxyribonucleotides to give biologically active DNA, semi-conservatively and sequentially in the proper gene order. HPUra can inhibit DNA replication by this system. We describe here the characteristics of HPUra inhibition and the conditions necessary for it to occur.
The arrow of electromagnetic time and the generalized absorber theory

The problem of the direction of electromagnetic time, i.e., the complete dominance of retarded electromagnetic radiation over advanced radiation in the universe, is considered in the context of a generalized form of the Wheeler-Feynman absorber theory in an open expanding universe with a singularity atT=0. It is shown that the application of a four-vector reflection boundary condition at the singularity leads to the observed dominance of retarded radiation; it also clarifies the role of advanced and retarded waves in the emission of very weakly absorbed radiation such as neutrinos.
C-reactive protein and serum amyloid A mRNA stability following induction by cytokines.

Abstract We determined the effects of cytokine withdrawal on C-reactive protein (CRP) and serum amyloid A (SAA) mRNA abundance in Hep3B cells following 24 h of preinduction with interleukin 6 plus interleukin 1β. After cytokine withdrawal, CRP transcription rate rapidly fell to undetectable levels and mRNA levels fell with a half-disappearance time of about 2.5 h. In view of the relatively small amount of CRP transcription occurring at this time, it is likely that this value closely re?ects the actual half-life of CRP mRNA. In contrast, substantial SAA transcription continued for at least 8 h, while SAA mRNA fell with a half-disappearance time of about 8.5 h. It is not possible, under these conditions, to determine SAA mRNA half-life, but it clearly was no greater than 8.5 h. Both Actinomycin D (ActD) and cycloheximide enhanced the stability of SAA mRNA, strongly suggesting that SAA mRNA degradation requires synthesis of a short-lived protein. CRP mRNA stability was also enhanced by ActD, but cycloheximide did not have a protracted stabilizing effect, suggesting complex regulatory processes. These studies provide insight into the stability of CRP and SAA mRNA following induction with [IL-6 + IL-1β] and into the mechanisms regulating their degradation.
Development of Tricuspid Valvular Regurgitation During the Course of Chronic Cor Pulmonale

A case of chronic cor pulmonale leading to tricuspid insufficiency is traced over a nine year period and the apparent rarity of this complication noted. Clinical findings are supported by a wide range of laboratory techniques including cardiac catheterization and cineangiography.
Helix Sense-Selective Polymerization of Chloral with Chiral Alkoxide Initiators: Tuning the Chiroptical Properties of the Polymer

The helix sense-selective polymerization of chloral with chiral lithium alkoxides derived from R(−), S(+)-2-octanol and four mono-hydroxy sterols afforded optically active polymer samples with high solid state optical rotations at the sodium D-line (589 nm). This chiroptical behavior stemmed from a predominance of a single screw direction along the polymer’s rigid helical backbone. The sign and magnitude of the optical rotation enhancements were found to depend upon both initiator structure and the conditions under which the polymerizations were carried out. By carefully manipulating experimental conditions, polychloral samples with specific rotations ranging from (+) 4000° to (−) 4000° were readily prepared. Model end-group studies confirmed that the presence of asymmetric initiator fragments in the polymer contributed little to the observed optical rotations reported here. Polychloral prepared with achiral or racemic initiators was optically inactive.
Vectorization of tree traversals

Abstract A simple method for vectorizing tree searches, which operates by processing all relevant nodes at the same depth in the tree simultaneously, is described. This procedure appears to be general, assuming that gather-scatter operations are vectorizable, but is most efficient if the traversals proceed monotonically from the root to the leaves, or vice versa . Particular application is made to the hierarchical tree approach for computing the self-consistent interaction of N bodies. It is demonstrated that full vectorization of the requisite tree searches is feasible, resulting in a factor ∼4–5 improvement in cpu efficiency in the traversals on a CRAY X-MP. The overall gain in the case of the Barnes-Hut tree code algorithm is a factor ∼2–3, implying a net speed-up of ≈400–500 on a CRAY X-MP over a VAX 11/780 or SUN 3/50.
High‐affinity L‐aspartate transporter in prostate epithelial cells that is regulated by testosterone

The prostate gland produces and secretes extraordinarily high levels of citrate. Studies with rat ventral prostate (VP) have demonstrated that aspartate can serve as a four-carbon source of oxalacetate in the synthesis of citrate. To achieve this, prostate secretory epithelial cells must contain a transport system for the active uptake of aspartate from circulation. The present studies with VP epithelial cells confirm the existence of a Na+ -dependent high-affinity L-aspartate transporter. The transporter has an optimal pH ≈ 7.5 and is temperature dependent. It appears to be an anionic amino acid transporter capable of transporting L-glutamate but not basic or neutral amino acids. The transporter is inhibited by ATPase inhibitors, thereby indicating its dependency on a Na+ gradient. The characteristics of the high-affinity L-aspartate transporter are consistent with its operation at the basilar membrane for the transport of circulating aspartate into the cell. Castration (24 hr) resulted in a significant decrease- in the ability of VP epithelial cells to transport L-aspartate. The administration of testosterone to castrated rats completely restored L-aspartate transport. In addition, in vitro testosterone addition (10−8 M for 30 min) to isolated prostate epithelial cells markedly increased L-aspartate transport. Both cycloheximide and actinomycin inhibited the testosterone effect. The studies reveal that testosterone is a regulator of this Na+ -dependent high-affinity L-aspartate transporter. The mechanism of this testosterone effect appears to involve both RNA and protein synthesis. We now have a model system to elucidate this novel effect of testosterone. © 1993 Wiley-Liss, Inc.
Efficacy of cancer prevention by high-selenium garlic is primarily dependent on the action of selenium

We reported previously that garlic cultivated with selenite fertilization showed powerful chemopreventive activity in the rat dimethylbenz[a]anthracene (DMBA)-induced mammary tumor model (Carcinogenesis 15, 573-576, 1994). In order to ascertain that the efficacy of the high-selenium garlic in cancer protection is primarily dependent on the action of selenium we compared the effects of two batches of garlic powder with marked differences in their level of selenium enrichment, 112 or 1355 p.p.m. Se dry weight. Both products were added to the diet to achieve the same final concentration of 2 p.p.m. Se. The supplementation protocol was designed to evaluate the efficacy during either the initiation phase or post-initiation phase of DMBA mammary carcinogenesis. Significant tumor reduction was observed with either treatment protocol. Furthermore, the magnitude tumor suppression, as well as the extent of DMBA-DNA adduct inhibition, were very similar with the two batches of garlic, even though the amounts of garlic in the diet varied considerably between them (1.8% for the 112 p.p.m. Se garlic versus 0.15% for the 1355 p.p.m. Se garlic). This suggests that the anti-cancer activity of the high-selenium garlic was likely to be accounted for by the effect of selenium, rather than the effect of garlic per se. A continuous feeding of the high-selenium garlic produced a modest increase in total selenium in various tissues. In general the profile of selenium accumulation was comparable in rats ingesting either the 112 or the 1355 p.p.m. Se garlic. Thus, based on the results of several biological responses, it appears that the ability of the high-selenium garlic to protect against tumorigenesis is primarily dependent on increased intake of selenium provided by the vegetable. Future research will be focused on the chemical form of selenium in the garlic.
Calculating Availability Bounds in Complex Systems and IP Network Topologies

A bounding algorithm, including resource consolidation, for high-precision estimation of connection availability is derived. Resource mincuts in a sample core IP network are generated to estimate the connection availability under different diversity assumptions.
The Law and Hiring Practices in Faith-Based Schools

A key concern of educational leaders in faith-based schools is their ability to hire faculty members who support institutional missions. Insofar as the American legal system protects the rights of leaders in faith-based schools to hire those who share in school goals, this article is divided into three substantive sections. The first section provides a brief historical-legal overview of faith-based schools in the United States. The next part highlights federal anti-discrimination statutes along with illustrations of litigation interpreting and applying these laws in disputes impacting on hiring practices in faith-based schools. The final substantive section offers five recommendations for educational leaders in faith-based schools who must walk the fine line between complying with their Church teachings and American civil law in making hiring decisions.
Calcium modulates aluminum neurotoxicity and interaction with neurofilaments

We examined the influence of calcium on neurotoxicity of AlCl3 and Al-lactate toward differentiated NB2a/d1 cells. Apart from induction of perikaryal neurofibrillary inclusions, AlCl3 at 1 mM induced no obvious additional signs of toxicity when added to culture medium in the presence of the normal medium CaCl2 content of 1.8 mM, nor when extracellular calcium was decreased by the addition to the medium of 0.9 mM EDTA. Increasing the extracellular CaCl2 concentration by fivefold was only marginally toxic, but in the presence of AlCl3, reduced viable cell numbers by well over 50% as compared to control cultures, and by approximately 50% vs fivefold CaCl2 alone. A twofold increase in extracellular CaCl2 did not increase the percentage of cells exhibiting Bielschowsky-positive perikarya but induced a near doubling in the percentage of cells exhibiting accumulations in the presence of 1 mM Al-lactate. AlCl3 (1 mM) retards the electrophoretic migration of NF subunits on SDS-gels. This effect was eliminated by withholding CaCl2 from the incubation mixture and including 5 mM EDTA during incubation of cytoskeletons with AlCl3. The presence of CaCl2 alone did not alter NF migration. These findings underscore the possibility that multiple factors, including those that compromise general neuronal homeostasis, may contribute to neurofibrillary pathology.
Early avoidance of traumatic stimuli predicts chronicity of intrusive thoughts following burn injury

The role of avoidance behavior in perpetuating the experience of intrusive thoughts among burn survivors was investigated. The Impact of Events Scale (IES), which has subscales that measure the frequency of intrusive thoughts and avoidance behavior, was administered to burn survivors (n = 23) upon discharge and four months later. Both avoidance behavior and intrusive thoughts at discharge were significantly related to experiencing intrusive thoughts at four months (r = 0.59, P < 0.003, r = 0.45, P < 0.03, respectively). In a hierarchical regression analysis controlling for intrusive thoughts at discharge, avoidance behavior continued to significantly predict intrusive thoughts at four months [B = 0.43, t(20) = 2.9, P < 0.009]. Limitations of the study and implications for treatment are discussed.
The concentrations of free amino acids and other electrolytes in cerebrospinal fluid, in vivo dialysate of brain, and blood plasma of the dog.

SUMMARY The concentrations of free amino acids in plasma, CSF and in vivo dialysates of peripheral blood (neck sac fluid) and central nervous tissue (brain sac fluid) from each of five dogs (neck sac fluid from four of five dogs) were determined by ion-exchange chromatography. Dialysates were obtained by implanting small dialysis sacs filled with a dextran-saline solution into the subcutaneous tissue of the neck or the parenchyma of the brain at least 10 weeks before sample collection. The mean plasma concentration of most amino acids was within the range of values reported in the literature for human or dog plasma. The concentrations of most amino acids were higher in the neck sac fluid than in plasma; this discrepancy, however, was, for the most part, small and could most likely be accounted for by falling plasma free amino acid levels prior to sample taking. Previous conclusions that the CSF concentrations of most amino acids are lower than plasma concentrations are confirmed, although the present work indicates that there may be considerable individual variation in the CSF/plasma distribution ratio with respect to most amino acids. In the brain sac fluid the concentration of nearly every amino acid was consistently higher than that in CSF and lower than that in the neck sac fluid. The potassium concentration in the brain sac fluid was significantly higher than, and the total osmolality significantly lower than, those in the neck sac fluid. On the assumption that the brain sac fluid represents a dialysate of the brain extracellular fluid, these results contradict recent findings (Bito and Davson, 1965; 1966) indicating that the potassium concentration of the cortex extracellular fluid is lower than that of ventricular or cisterna magna CSF and certainly lower than that of plasma. Because of this and on the basis of consideration of the reaction of the brain to a foreign body, the possibility that the implanted brain sac lay on the‘blood side’of the bloodbrain barrier was suggested. Some implications of this possibility are discussed.
PHOTOELECTRON SPECTROSCOPY AT OXFORD, 1970-71

Abstract Presented herein is a recollection of a postdoctoral year spent in David Turner's laboratory in Oxford, 1970–71.
Monopole Catalysis of Skyrmion Decay

Abstract A semiclassical model of baryon-monopole interactions is presented. The model, which could serve as the basis for practical calculations of catalysis cross sections, interpolates between a soliton model of baryons at large distances and a radial field theory near the monopole core.
Tissue distribution and pharmacokinetics of 3H-butylated hydroxyanisole in female mice.

Butylated hydroxyanisole (BHA), a commonly used food additive, is a phenolic antioxidant. While metabolism of BHA has been studied in dog, man, rabbit and rat, information on tissue distribution is limited to rat and dog. Time dependent distribution and elimination of3H-BHA following a single oral dose of 50 mg/kg body weight in female Swiss-Webster mice were investigated. Animals were sacrificed at time intervals up to 168 h after dosing. Levels of3H were determined by liquid scintillation counting in the following tissues: brain, blood, serum, fat, heart, kidney, liver, lung, skeletal muscle and spleen. In most tissues the decline of BHA (log) was nonlinear with respect to time; a biphasic, post-absorptive aspect was observed. The highest3H activity was noted in kidney and liver 15 min after dosing. The lowest activity was in fat. In addition, a peak3H activity was recorded at 3 and 10 h after dosing for the blood and brain, respectively. Distribution of the3H-BHA in mouse organs is similar to that in rat.
Considerations on the Flynn Effect

Flynn has proposed a grand integrative theory, which he calls “scientific spectacles,” to explain the phenomenon of rising IQ scores across multiple decades known as the Flynn effect (FE). In his theory, he purports that modern society has placed increasing value and emphasis on the application and education of scientific principles—which include abstract fluid reasoning—and this has mirrored larger score increases in the abstract fluid reasoning tasks included as part of most intelligence tests. He highlights huge gains in the Wechsler Similarities subtest over time as one linchpin supporting his theory that fluid reasoning is rising faster than other aspects of intelligence, but further points to large increases in Wechsler performance tasks (i.e., perceptual organization and reasoning) relative to crystallized tasks, and to the many studies of Raven’s Progressive Matrices, which is widely held to be a fairly pure measure of fluid reasoning. As with any new theory of this magnitude, Flynn’s grand propos...
Shuttle navigation system

This paper will be an overview of the critical orbital flight missions for which navigation performance is well defined relative to the various mission phases and key events (e.g. ascent, orbital coast, deorbit, entry, drag acquisition, post blackout, Terminal Area Energy Management and Autoland). Special emphasis will be given to those missions, events and performance parameters that are drivers of navigation accuracy. The navigation sensors will be described and their usefulness in keeping navigation accuracy within specified limits will be discussed by mission phases.
Alternative Synthesis of C60‐Diphenylaminofluorene Derivatives for Nonlinear Photonic Applications: Method of Preparation and Characterization

An alternative synthetic route for the preparation of key intermediate synthons 7‐α‐bromoacetyl‐2‐diphenylaminofluorene (α‐BrDPAF‐H) and 7‐α‐bromoacetyl‐9,9‐dialkyl‐2‐diphenylaminofluorene (α‐BrDPAF‐Cn) was demonstrated. The latter reactions involved the first step of dialkylation of 2‐bromofluorene at C9 position of the fluorene moiety, the second step of a diphenylamino group attachment at C2 position of the resulting dialkylfluorene, and the third step of Friedel‐Craft acylation of α‐bromoacetyl group at C7 position of dialkylated diphenylaminofluorene. From the intermediates α‐BrDPAF‐H and α‐BrDPAF‐Cn, a series of C60‐keto‐DPAF nanostructures, such as the fullerene monoadducts C60(>DPAF‐H) and C60(>DPAF‐Cn), where n is 2, 4, or 10, were synthesized in a reasonable yield. Molecular mass ions of the dyads C60(>DPAF‐H), C60(>DPAF‐C2), C60(>DPAF‐C4), and C60(>DPAF‐C10) were clearly detected in positive ion matrix‐assisted laser desorption ionization mass spectrum (MALDI–MS) that confirmed the composition ...
Monitoring and controlling in-process inventories within high-rise storage via time series analysis

The use of time series analysis to characterize the behaviour of machine centre queues of in-process inventory stored within an automated high-rise warehousing system is discussed. By treating queue behaviour as a first-order continuous process, a time constant value is obtained which indicates imbalance in the shop. This value provides a basis for interpretation and control by shop floor managers without direct observation of the queues of in-process materials. Actual time series data of in-process inventory are modelled and interpreted using this approach. Practical aspects of data sampling and parameter estimation are also considered.
A microcomputer-controlled square-wave polarograph.

Abstract A dedicated microcomputer has been developed for control and operation of a square-wave polarograph. Microcomputer control allows a high degree of variation in the experimental parameters, such as square-wave frequency, gate delay times, gate aperture, drop-time, the amplitude of the square wave, and the magnitude of the staircase rise, but still maintains the required coherency in the signals so that an appropriate separation between the faradaic and capacitance currents is achieved. The variation is achieved through software control. Measurement is accomplished by the application of a multiplicity of square waves to each “tread” of a staircase voltage, thus providing a true square-wave polarogram.
FREQUENCY DOMAIN TECHNIQUES FOR FAST GPS ACQUISITION AND INTERFERENCE DETECTION/REJECTION

In earlier work, methods for using fast Fourier transform (FFT) techniques to process digitized GPS and GLONASS signals were presented. This paper presents data collected among the largest buildings in Hartford, Connecticut. Consistent with our laboratory findings, field analysis suggests that the FFT method is able to extract the times of arrival (TOAs) of the satellite signals given only brief glimpses of the signals, resulting in a receiver that can track more satellites than conventional receivers when operating in urban canyons. In addition, a method based on dynamic programming is presented which makes use of local maxima in the cross-correlation functions to find the optimal trajectory, thereby further increasing fix availability. Finally, a method of implementing the optimum matched filter for colored noise and interference is described. It is shown that the filter improves performance even when noise and interference are limited to white noise and other satellites, and notching/filtering noise as wide as 1.44 MHz centered in the GPS band is illustrated.
Quality Improvement of Clustering Engine in the Internet Based on Correlation

Search engines give so many results that a user cannot handle them all in a short period of time. Many approaches have been proposed to alleviate this problem. For example, some approaches try to add personalized features and some try to group the results into different categories. The latter one is called a clustering engine, which is the emphasis of this paper. It first reviews several existing approaches such as STC, SHOC, LINGO and SnakeT. It then gives a new approach called HICSEC (Hierarchical Clustering Search Engine with Correlation) to improve the accuracy of clustering by the Correlation calculated with the Singular Value Decomposition.
Nonnegativity, reducibility, and semistability of mass action kinetics

Mass action kinetics have numerous analytical properties that are of inherent interest from a dynamical systems perspective. We provide a general construction of the kinetic equation from reaction laws based upon the formulation given by Erdi et al. (1988). We consider the nonnegativity of the solutions to the kinetic equation, the reducibility of the mass action kinetics, and the stability of the equilibria of the kinetic equation. To do this, we apply Lyapunov methods to the kinetic equation and obtain results that guarantee semistability, that is, convergence to an equilibrium that depends upon initial concentrations. This notion was previously developed by the authors (1995, 1999), which extends the linear semistability theory to nonlinear systems. Finally, we revisit the "zero deficiency" result given by Feinberg (1995), which provides rate-independent conditions guaranteeing stability.
Importance of Filament Reactivity for CVD Diamond Growth

The behavior of tungsten filaments heated up to 2500°C in mixtures of CH4 or C2H2 and H2 at P = 9 and 25 Torr is analyzed. It has been found that the filament resistance R, spectral emissivity ϵ, power consumption, and CH4 and C2H2 partial pressures depend critically on the filament temperature as well as the reactant CH4/ H2 or C2H2/ H2 fraction. We interpret these results on the basis of a thermodynamic model which predicts that transitions between deposition and etching of solid carbon occur on the filament surface at high temperatures. The implications of these results for diamond CVD are discussed. Evidence for gas phase reactions is also presented.
Children and Funerals

Death is the most inevitable and irrevocable problem that we face as physicians and human beings. Although many people seldom think about death, when the death of a close friend or relative does occur, everyone is confronted with a feeling of loss and reminder of his or her own mortality. The emotional reaction triggered by such a loss is called mourning. While in decades past it was debated whether or not children mourned, the consensus now is that they do, but not as completely or satisfactorily as adults. The manner in which children mourn is based on their level of development and on the emotional climate provided them. Almost without exception in our society, when a person dies, there is a funeral. More often than not parents do not know whether children should attend funerals. Because of this, they often ask pediatricians, but there is little published data that can be used as a guide for an intelligent response. The purpose of this review is to provide practical guidelines and suggestions that can be discussed with parents when this question arises. FUNERALS IN GENERAL The funeral is the most ancient rite known. Much of what we know about prehistoric cultures comes from burial customs that favored including everyday objects with the corpse.
Extratropical Transition of Western North Pacific Tropical Cyclones: An Overview and Conceptual Model of the Transformation Stage

Abstract Extratropical transition (ET) in the western North Pacific is defined here in terms of two stages: transformation, in which the tropical cyclone evolves into a baroclinic storm; and reintensification, where the transformed storm then deepens as an extratropical cyclone. In this study, 30 ET cases occurring during 1 June–31 October 1994–98 are reviewed using Navy Operational Global Atmospheric Prediction System analyses; hourly geostationary visible, infrared, and water vapor imagery; and microwave imagery. A brief climatology based on these cases is presented for the transformation stage and the subsequent cyclone characteristics of the reintensification stage. A three-dimensional conceptual model of the transformation stage of ET in the western North Pacific Ocean is proposed that describes how virtually all 30 cases evolved into an incipient, baroclinic low. The three-step evolution of the transformation of Typhoon (TY) David (September 1997) is described as a prototypical example. Four importa...
Determination of the total grain size distribution in a Vulcanian eruption column, and its implications to stratospheric aerosol perturbation

The total grain distribution of tephra from the eruption by the Fuego volcano in Guatemala on Oct. 14, 1974 was determined by grain size analysis. The region within each isopach has a grain distribution which was weighted proportionally to its percentage volume; the total distribution had a median grain size of 0.6 mm and a sorting coefficient of 2.3. The ash composed of fine particles did not fall in the volcano area as part of the recognizable tephra blanket; the eruption column reached well into the stratosphere to the height of 10-12 km above sea level, with mass flux rate estimated altitudes of 18-23 km
Precipitation pulses and soil CO2flux in a Sonoran Desert ecosystem

Precipitation is a major driver of biological processes in arid and semiarid ecosystems. Soil biogeochemical processes in these water-limited systems are closely linked to episodic rainfall events, and the relationship between microbial activity and the amount and timing of rainfall has implications for the whole-system carbon (C) balance. Here, the influences of storm size and time between events on pulses of soil respiration were explored in an upper Sonoran Desert ecosystem. Immediately following experimental rewetting in the field, CO2 efflux increased up to 30-fold, but generally returned to background levels within 48 h. CO2 production integrated over 48 h ranged from 2.5 to 19.3 g C m−2 and was greater beneath shrubs than in interplant spaces. When water was applied on sequential days, postwetting losses of CO2 were only half a large as initial fluxes, and the size of the second pulse increased with time between consecutive events. Soil respiration was more closely linked to the organic matter content of surface soils than to rainfall amount. Beneath shrubs, rates increased nonlinearly with storm size, reaching an asymptote at approximately 0.5 cm simulated storms. This nonlinear relationship stems from (1) resource limitation of microbial activity that is manifest at small time scales, and (2) greatly reduced process rates in deeper soil strata. Thus, beyond some threshold in storm size, increasing the duration or depth of soil moisture has little consequence for short-term losses of CO2. In addition, laboratory rewetting across a broad range in soil water content suggest that microbial activity and CO2 efflux following rainfall may be further modified by the routing and redistribution of water along hillslopes. Finally, analysis of long-term precipitation data suggests that half the monsoon storms in this system are sufficient to induce soil heterotrophic activity and C losses, but are not large enough to elicit autotrophic activity and C accrual by desert shrubs.
Abbott ARCHITECT iPhenytoin assay versus similar assays for measuring free phenytoin concentrations.

Objective: To measure free phenytoin (FP) concentrations in filtered specimens using the Abbott ARCHITECT i Phenytoin assay and to compare results from this method with results from the Abbott TDx/FLx assays. Methods: We verified accuracy, analytic measurement range, and precision for FP measurements. For correlation and therapeutic interval studies, we used filtered calibrators, controls, proficiency-testing materials, and surplus clinical samples. After implementation, we determined proficiency testing results. Results: The analytic measurement range was 2.0 to 25.0 μmol/L. Quality control materials (6.1, 12.6, and 20.1 μmol/L) provided mean (SD) recoveries of 96.1 (5.0%), 99.2 (5.0%), and 99.3 (5.7%), respectively, and coefficients of variation of 5.2%, 5.0%, and 5.8%, respectively. Clinical specimens produced mean (SD) FP recovery levels of 103.7 (10.6%) (bias, 0.1 [0.3] μmol/L). Altering the FP therapeutic range (4.0–8.0 μmol/L) was unnecessary. Proficiency testing yielded consistently acceptable results. Conclusion: Our accuracy, precision, and correlation results were similar for the TDx/FLx and ARCHITECT assays, which demonstrates that the ARCHITECT i Phenytoin assay is acceptable for clinical FP measurements. * TP : total phenytoin CNS : central nervous system FP : free phenytoin FLMII : fetal lung maturity II CAP : College of American Pathologists LLOQ : lower limit of quantitation QC : quality control AMR : analytic measurement range FPIA : fluorescence polarization immunoassay EMIT : enzyme-multiplied immunoassay technique CMIA : chemiluminescent microparticle immunoassay CV : coefficient of variation TE : total error FDA : United States Food and Drug Administration
Supporting change and scholarship through review of online resources in professional development settings

How can we accelerate innovation and ensure effective dissemination of knowledge about online learning resources? This paper advocates strategies that systematically link online professional development with the research, development and diffusion cycle. The systemic approach we describe can accelerate knowledge advancement and help manage change by improving communication among teachers, trainers, developers and researchers. The examples that are provided are set within two funded projects in the United States that led to the development of two distinct but related strategies—the Online Site Evaluation Form for educators (a web-based review form used in workshops) and a six-week online course on technology-supported assessments. Both strategies make it easier to give feedback to developers and offer incentives to do so in ways that help teachers to learn about online resources individually and with colleagues. The examples are discussed with analysis of their strengths and weaknesses in supporting different modes of interaction. We highlight implications for instructional development, professional development, research and knowledge management in online communities.
Adaptive haptic framework

Research work that has been performed in the area of haptics have surely produced some remarkable results; there is a good variety of haptic devices that possess the potential to offer users a rich experience in a virtual reality setting. However, users always face difficulties in operating in such environments. Without doubt the need of users having to 'adjust to' operating haptic devices is an inconvenience. Nevertheless the lack of a uniform controlling mechanism able to use fully the abilities of haptic devices according to each user's personal attributes and needs is the main hurdle that must be overtaken. To bring about such architecture is an inspiring adventure that presents some challenges, but in turn, is immensely rewarding. The architecture that we are proposing is a layer based approach to overcome the lack of a uniform controlling mechanism that makes full use of the functionalities of haptic devices according to each user's personal needs. This framework is integrated with a behavioral data container, which defines the personalized information of the users. The latter is our context-aware, or intelligent component that dictates what device to use and how, according to the user's data that has already been collected and analyzed. This intelligent component takes the decisions and directs the user to the appropriate environment. With the relevant software and hardware, it is possible to offer to the user optimum experience of a haptic-induced virtual world.
High gradient studies for ILC with single-cell re-entrant shape and elliptical shape cavities made of fine-grain and large-grain niobium

Based on the encouraging results of the first 1300 MHz 70 mm aperture single-cell re-entrant cavities, we continue the high gradient studies for ILC with new re-entrant cavities made of fine-grain as well as large-grain niobium. These new cavities have smaller apertures of 60 mm, providing a further reduced Hpk/Eacc or a further improved ultimate gradient. Four 1300 MHz 60 mm aperture reentrant cavities are made, two out of fine grain niobium and the other two out of large-grain niobium. In addition, two elliptical shape 1500 MHz cavities are also made out of large-grain niobium. A new record gradient of 59 MV/m was achieved in a 60 mm aperture 1300 MHz single-cell fine-grain niobium cavity.
Vibration of Beam Structures

We treat the dynamics of beams in a manner similar to that for rods. The sequence of analysis followed is: derive the governing differential equations, use spectral analysis to obtain general solutions, obtain an exact matrix formulation, obtain an approximate matrix formulation.
Delineation of mu-antagonist, partial kappa agonist and non-opioid agonist activity of cyclazocine using urinary output of rats.

Abstract The effects of cyclazocine (SC) were studied under a variety of test conditions to determine its various activities on urinary output. Cyclazocine antagonized the morphine-induced (20 mg/kg), antidiuretic effect in water-loaded (3 ml/100 g b.wt.) rats at low doses (0.08, 0.16 and 0.32 mg/kg). At high doses (1.25, 5 and 20 mg/kg), cyclazocine caused diuresis in normally hydrated rats. The diuresis produced by 1.25 and 5, but not 20 mg/kg, was antagonized by naloxone (10 mg/kg). In water-deprived rats and in normally hydrated rats, cyclazocine, in a dose-related fashion, antagonized the diuretic effects of 0.08 mg/kg of bremazocine. These results are compatible with the interpretation that cyclazocine has mu-antagonist activity at low doses, then partial kappa-agonist activity at intermediate doses, followed by non-opioid agonist activities at the higher doses.
Psychiatric and Cognitive Disorders in Parkinson's Disease

Most doctors are familiar with Parkinson's disease, and treatment with levodopa was one of the great and stunning advances of the last century. Much less well understood are associated disorders such as dementia, hallucinations, psychosis and depression, which cause huge morbidity and require active and competent management. Together with cognitive defects, these tend to become more troublesome as the disease progresses. By that stage, management of all aspects of the illness has often passed from the neurologist to a community health team. I have increasingly felt the need to be expert in the management of Parkinson's disease. Psychiatric and Cognitive Disorders in Parkinson's Disease is an excellent text that should be helpful not only to old-age psychiatrists such as me but also to general practitioners, community health nurses and neurologists. It puts an evidence base behind many of the things I and my colleagues have had to derive from clinical experience. For example, in the treatment of psychosis, it has long been recognized that parkinsonism more commonly develops with olanzapine than with quetiapine or risperidone. With the advent of atypical antipsychotics there has been a great need for information on best use in patients with Parkinson's disease. Seemingly clozapine has advantages, despite the hazard of neutropenia. In the book there are good discussions on the mechanisms of cognitive impairment and how it relates to age, duration of illness and so on. A breakdown of cognitive deficits into types—e.g. bradyphrenia, visuospatial function, executive function, speech and language—offers a better understanding of the complex pictures we encounter in patients. One surprising omission is drugs for Parkinson's disease dementia and Lewy-body dementia—for which the evidence base is strong. By contrast, depression is well handled, with well based advice on the sort of antidepressant to consider. The book points out that electroconvulsive therapy should not be forgotten; as well as improving depression and psychosis it can lessen the motor symptoms of Parkinson's disease. It is clear to me that primary care and community health services require sufficient understanding of Parkinson's disease to diagnose and treat its psychiatric manifestations. Starkstein and Merello have provided a much needed text and I strongly recommend it.