cssi/SciSciGPT-SciSciNet huggingface dataset:
Acceleration of oxidative folding of bovine pancreatic ribonuclease A by anion-induced stabilization and formation of structured native-like intermediates

Phosphate anions accelerate the oxidative folding of reduced bovine pancreatic ribonuclease A with dithiothreitol at several temperatures and ionic strengths. The addition of 400 mM phosphate at pH 8.1 increased the regeneration rate of native protein 2.5-fold at 15°C, 3.5-fold at 25°C, and 20-fold at 37°C, compared to the rate in the absence of phosphate. In addition, the effects of other ions on the oxidative folding of RNase A were examined. Fluoride was found to accelerate the formation of native protein under the same oxidizing conditions. In contrast, cations of high charge density or ions with low charge density appear to have an opposite effect on the folding of RNase A. The catalysis of oxidative folding results largely from an anion-dependent stabilization and formation of tertiary structure in productive disulfide intermediates (des-species). Phosphate and fluoride also accelerate the initial equilibration of unstructured disulfide ensembles, presumably due to non-specific electrostatic and hydrogen bonding effects on the protein and solvent.
SOCIAL WORKERS AND THE NASW CODE OF ETHICS: BELIEF, BEHAVIOR, DISJUNCTURE

A quantitative descriptive survey of a national sample of social workers (N = 206) examined discrepancies between belief in the NASW Code of Ethics and behavior in implementing the code and social workers' disjunctive distress (disjuncture) when belief and behavior are discordant. Relationships between setting and disjuncture and ethics education and disjuncture were also examined. Variables were measured with a survey instrument that was based on the NASW Code of Ethics and that incorporated a validated professional opinions scale. Findings indicated disjuncture when belief and behavior scores were discordant; lower disjuncture occurred when behavior was congruent with the code, and disjuncture increased with incongruent behavior. Belief in the code did not influence behavior congruent with the code. There were significant disjuncture score differences among different work settings, with the highest scores among social workers in public agencies and the lowest among those in private agencies. Lower discordance of belief and behavior scores and lower belief scores occurred among those who took separate ethics courses, perhaps making them more doubtful about implementing the code in the real world. Respondents said they valued their work more with supervision; however, the amount of clinical and administrative supervision decreased with time.
Savoring, resilience, and psychological well-being in older adults

Objectives: Guided by Fredrickson's broaden and build theory of positive emotions and Zautra's dynamic model of affect, the current study examines the relation between savoring positive experiences (i.e., the ability to notice and regulate positive feelings) and psychological well-being for older adults with higher and lower levels of resilience.Method: A sample of 164 (74% female) older adults living in a large metropolitan area participated in this study. Participants were recruited from a continuing care retirement community and community centers in the surrounding area. Participants completed a survey measuring savoring, resilience, happiness, depression, and satisfaction with life.Results: In older adults, greater ability to savor positive experiences and higher resilience both predicted greater happiness, lower depression, and greater satisfaction with life (i.e., greater psychological well-being). Savoring is associated with positive outcomes for people with higher and lower levels of resilience. H...
Studies of the Hydrolysis and Polymerization of Silicon Alkoxides in Basic Alcohol Solutions

We report here an experimental technqiue based on changes in reaction medium volume which we have used to observe the kinetics of hydolysis and polymerization of TEOS in aqueous ethanol solutions containing NH3. Our results show that there are three distinct reaction regions. By combining these results with determinations of change in reaction medium conductivity and average particle size, we are able to link the short and long time regions to TEOS hydrolysis and particle growth respectively. The intermediate reaction time region is not associated with hydrolysis, loss of ionic species due to condensation or to particle growth.
Use of mycorrhizae for land rehabilitation

Utilization of vesicular-arbuscular mycorrhizae (VAM) markedly increases the success of rehabilitation of disturbed and degraded lands, either in mesic or in moisture-deficient zones. It has been demonstrated that the presence of VAM is critical for the regeneration of natural ecosystems in arid lands. Inoculation techniques for rehabilitation have been tested and are considered highly valuable for the purpose, but until improved inocula production methods are developed, the best alternative is a proper management of a site, preventing loss and assuring maintenance of an appropriate plant cover, where the roots serve as an energy source and medium for VAM proliferation. Re-establishment of plant cover on denuded lands has been tested by using succession theory by priming natural processes and thereby enhancing the rate of succession. The introduction and appropriate management of VAM in these tests has shown highly positive effects on the results. The international concern and support for such activities has been expressed by the UNEP-ISEB Workshop, 1983, recommending immediate applications of available VAM technologies in rehabilitation, and extensive further research efforts for the utilization of VA mycorrhizae.
Critique of exact linearization strategies for process control

Abstract During the last decade significant progress has been made in the control of non-linear systems. Some of the most promising controller design techniques are based on exact linearization theory. In this paper, exact linearization strategies for process control are critically evaluated. It is shown that many design techniques recently developed for non-linear process control are based, either implicitly or explicitly, on exact linearization of the input-output map. Extensions of basic techniques that are especially pertinent for process control problems are reviewed and evaluated. A thorough survey of applications to process control problems is included. Finally, an input-output linearizing controller is designed for a different process control problem, pH neutralization, and simulation results are presented. This example demonstrates that input-output linearization can be extended to the class of problems where the output equation is an implicit rather than explicit function of the state variables.
A Sampling Bias in Identifying Children in Foster Care Using Medicaid Data

Background.—Prior research identified foster care children using Medicaid eligibility codes specific to foster care, but it is unknown whether these codes capture all foster care children. Objectives.—To describe the sampling bias in relying on Medicaid eligibility codes to identify foster care children. Methods.—Using foster care administrative files linked to Medicaid data, we describe the proportion of children whose Medicaid eligibility was correctly encoded as foster child during a 1-year follow-up period following a new episode of foster care. Sampling bias is described by comparing claims in mental health, emergency department (ED), and other ambulatory settings among correctly and incorrectly classified foster care children. Results.—Twenty-eight percent of the 5683 sampled children were incorrectly classified in Medicaid eligibility files. In a multivariate logistic regression model, correct classification was associated with duration of foster care (>9 vs 3 vs 1 placement, OR 4.20, 95% CI 3.14–5.64), and placement in a group home among adjudicated dependent children (OR 1.87, 95% CI 1.33–2.63). Compared with incorrectly classified children, correctly classified foster care children were 3 times more likely to use any services, 2 times more likely to visit the ED, 3 times more likely to make ambulatory visits, and 4 times more likely to use mental health care services (P Conclusions.—Identifying children in foster care using Medicaid eligibility files is prone to sampling bias that overrepresents children in foster care who use more services.
Statistical counterpoint: knowledge discovery of choreographic information using spatio-temporal analysis and visualization

Abstract Temporal GIS has rapidly moved from concepts and methods that took its inspiration based on theories largely developed in a data-poor setting, to a situation where tools and theories are needed for large, individual-level, spatio-temporally detailed data sets. We present work to develop a rich data base on choreographic information and use it as a test-bed for existing geovisual approaches to temporal data. Our visual analysis demonstrates the ability of linked, multivariate displays to pull out distinct differences and similarities in activity patterns and temporal clustering. We also include illustrative animations that identify some practical limitations of existing exploratory software in dealing with large volumes of spatio-temporal data.
Parallel Acceleration of Evolutionary Rates in Symbiont Genes Underlying Host Nutrition

The overproduction of essential amino acids by Buchnera aphidicola, the primary bacterial mutualist of aphids, is considered an adaptation for increased production of nutrients that are lacking in aphids' diet of plant sap. Given their shared role in host nutrition, amino acid biosynthetic genes of Buchnera are expected to experience parallel changes in selection that depend on host diet quality, growth rate, and population structure. This study evaluates the hypothesis of parallel selection across biosynthetic pathways by testing for correlated changes in evolutionary rates at biosynthetic genes of Buchnera. Previous studies show fast evolutionary rates at tryptophan biosynthetic genes among Buchnera associated with the aphid genus Uroleucon and suggest reduced purifying selection on symbiont nutritional functions in this aphid group. Here, we test for parallel rate acceleration at other amino acid biosynthetic genes of Buchnera-Uroleucon, including those for leucine (leuABC) and isoleucine/valine biosynthesis (ilvC). Ratios of nonsynonymous to synonymous substitutions (d(N)/d(S)) were estimated using codon-based maximum-likelihood methods that account for the extreme AT compositional bias of Buchnera sequences. A significant elevation in d(N)/d(S) at biosynthetic loci but not at two housekeeping genes sampled (dnaN and tuf) suggests reduced host-level selection on biosynthetic capabilities of Buchnera-Uroleucon. In addition, the discovery of trpEG pseudogenes in Buchnera-U. obscurum further supports reduced selection on amino acid biosynthesis.
Multispin correlations and pseudothermalization of the transient density matrix in solid-state NMR: Free induction decay and magic echo

Quantum unitary evolution typically leads to thermalization of generic interacting many-body systems. There are very few known general methods for reversing this process, and we focus on the magic echo, a radio-frequency pulse sequence known to approximately ``rewind'' the time evolution of dipolar coupled homonuclear spin systems in a large magnetic field. By combining analytic, numerical, and experimental results, we systematically investigate factors leading to the degradation of magic echoes, as observed in reduced revival of mean transverse magnetization. Going beyond the conventional analysis based on mean magnetization, we use a phase-encoding technique to measure the growth of spin correlations in the density matrix at different points in time following magic echoes of varied durations and compare the results to those obtained during a free induction decay. While considerable differences are documented at short times, the long-time behavior of the density matrix appears to be remarkably universal among the types of initial states considered: simple low-order multispin correlations are observed to decay exponentially at the same rate, seeding the onset of increasingly complex high-order correlations. This manifestly athermal process is constrained by conservation of the second moment of the spectrum of the density matrix and proceeds indefinitely, assuming unitary dynamics.
Substance-Abusing Women and Their Children: A Cost-Effective Treatment Option to Incarceration

ABSTRACT Low-level drug offenses are presently the top reason women are sent to jail. Because more than 70% of these incarcerated women are the primary caretakers of children, incarceration has resulted in a sharp rise in foster care demand. Research suggests that incarcerated women who remain with their children are more likely to enter and complete treatment. This paper reviews the effects of incarceration and the available treatment options for substance-abusing women with children. A self-supported, self-run, alternative treatment model known as Oxford House is suggested as an option for women with children to gain financial and emotional stability.
On Convection in the Upper Mantle

Summary Present estimates of viscosity and other pertinent parameters make it unlikely that thermal convection exists in the lower mantle. Convection may be considered from the point of view of an instability process for the upper mantle but the probable non-Newtonian nature of viscosity in the upper mantle makes this problem difficult to solve. Criteria are suggested which evaluate the pertinence of the convection current hypothesis to the upper mantle, and which are formally independent of the viscosity. Estimates of these quantities can be obtained from the model in which Newtonian viscosity is used. The postulate is introduced that, since these quantities are independent of the viscosity, their estimates will apply, to order of magnitude, to other models of viscosity. The estimates of (1) the time necessary to set up stable convection and (2) the gravity anomaly expected over a convecting mantle are consistent with the hypothesis of convection in the upper mantle. The estimates (3) of the depression of the geoid over a rising current and (4) of the horizontal scale of the convection cells appear to yield results inconsistent with convection in the upper mantle.
Low voltage ride through capability enhancement of grid connected PV system by SDBR

Penetration of Photovoltaic (PV) power to the grid is increasing very rapidly. Energy regulatory body is imposing much stricter grid code due to this high penetration of the PV power. Grid connected PV system encounters different types of abnormalities during grid faults. When the fault appears in the grid side, the point of common coupling (PCC) voltage will go very low which will cause the DC link voltage very high for power balancing. This high DC link voltage may damage the inverter. Also, the voltage sag will force the PV system to be disconnected from the grid according to grid code. And shutdown of large PV plant may have adverse effect in power system operation. This study proposes series dynamic braking resistor (SDBR) to counteract the effect of faults in the grid side and hence prevents the voltage sag in grid side. Improving voltage sag by the proposed method will enhance the low voltage ride through (LVRT) capability of the PV plant. The effectiveness of the proposed method is verified by applying the most severe fault (three-phase-to-ground fault). The terminal voltage obtained with proposed protection scheme maintains the grid code, and hence the PV systems need not to be disconnected from the grid during fault.
Activation of Hydrogen Peroxide by an Fe-TAML Complex in Strongly Alkaline Aqueous Solution: Homogeneous Oxidation Catalysis with Industrial Significance

Hydrogen peroxide is activated by homogeneous Fe-TAML catalysts in aqueous solutions containing very high levels of sodium hydroxide, sodium aluminate, and other inorganic salts. Under these conditions, the Fe-TAML catalyst system facilitates oxidation of humic and humic-derived compounds under ambient conditions and efficiently uses catalyst and oxidant. Darkly colored process liquor from aluminum refining (Bayer liquor) is decolorized by 40−70% (in the wavelength range 450−650 nm) in just 5 min. Humic substances and phenolic species were targeted by the oxidation process. In addition to color reduction, Fe-TAML/H2O2 in 5 M NaOH can also extensively degrade the five- or six-carbon polyols, mannitol, sorbitol, dulcitol, xylitol, and adonitol. This is the first time Fe-TAML catalysts have been shown to activate degradation of carbohydrate alcohols. We show that mannitol, a nuisance contaminant in alumina production, can be oxidized at millimolar levels in process liquor containing a wide variety of other o...
Modeling of electron mobility in gated silicon nanowires at room temperature: Surface roughness scattering, dielectric screening, and band nonparabolicity

We present a theoretical study of electron mobility in cylindrical gated silicon nanowires at 300 K based on the Kubo-Greenwood formula and the self-consistent solution of the Schrodinger and Poisson equations. A rigorous surface roughness scattering model is derived, which takes into account the roughness-induced fluctuation of the subband wave function, of the electron charge, and of the interface polarization charge. Dielectric screening of the scattering potential is modeled within the random phase approximation, wherein a generalized dielectric function for a multi-subband quasi-one-dimensional electron gas system is derived accounting for the presence of the gate electrode and the mismatch of the dielectric constant between the semiconductor and gate insulator. A nonparabolic correction method is also presented, which is applied to the calculation of the density of states, the matrix element of the scattering potential, and the generalized Lindhard function. The Coulomb scattering due to the fixed i...
EpoDB: a database of genes expressed during vertebrate erythropoiesis.

EpoDB is a database designed for the study of gene regulation during differentiation and development of vertebrate red blood cells. In building EpoDB, we have taken the in advance approach to the data integration problem: we have extracted data relevant to red blood cells from GenBank, SWISS-PROT, TRRD (transcriptional regulation data) and GERD (expression levels data) to create a single integrated, highly curated view. Tools have been developed to automate data extraction from online resources, cleanse data of errors, enter information manually from the primary literature, generate a uniform, canonical representation of information and maintain data currency. The database is organized around biological features, e.g., genes, rather than sequences, which are supported by a controlled and consistent vocabulary for gene names and gene family names. Beyond the standard database queries, the functionality of EpoDB includes the ability to extract features and subsequences, display sequences and features graphically using bioWidget viewers and integrated analysis tools. EpoDB may be accessed at: http://cbil.humgen.upenn.edu/epodb/
Flow Duration Curve Using Entropy Theory

AbstractUsing the entropy theory, this study derives a function for modeling the flow duration curve (FDC) based on two equations that form simple constraints: (1) the total probability of all flow discharges, and (2) the mean discharge. Parameters of the derived curve are determined from the entropy theory with the use of these two constraints. For deriving the flow duration curve by the entropy theory, a nonlinear cumulative distribution function is assumed, which is tested using observed flow data. The derived flow duration curves are tested using field data and are found to be in agreement with observed curves. With the entropy parameter determined for each station, the flow duration curve can also be forecasted for different recurrence intervals. The main advantage of the use of the entropy theory–based FDCs is that the parameters are based on observations, and hence no fitting is needed. Second, the theory permits a probabilistic characterization of the flow duration curve and hence the probability ...
The connection between centrifugal instability and Tollmien Schlichting-like instability for spiral Poiseuille flow

For spiral Poiseuille flow with radius ratio η ≡ R i /R o = 0.5, we have computed complete linear stability boundaries for several values of the rotation rate ratio μ ≡ Ω o /Ω i , where R i and R o are the inner and outer cylinder radii, respectively, and Ω i and Ω o are the corresponding (signed) angular speeds. The analysis extends the previous range of Reynolds number Re studied computationally by more than eightyfold, and accounts for arbitrary disturbances of infinitesimal amplitude over the entire range of Re for which spiral Poiseuille flow is stable for some range of the Taylor number Ta
Outgassing measurements on actuator used for solar array deployment

Experimental studies on the silicone oil-damped actuators used to deploy solar panels on satellites were performed under a variety of thermal conditions. The studies were performed in order to determined if material, detrimental to the performance of the panels or other similar equipment, emanated from the actuators. It was observed that volatile components present in the silicon oil were not released from the interior of the device during thermal cycling. It was observed, however, that the surface of the test actuator examined was contaminated with a volatile hydrocarbon(s) as a consequence of an inadequate cleaning process. This process was modified and flight actuators were found to be adequately free of this contamination.
Psychological patterns and coronary heart disease: an appraisal of the determination of etiology by means of a stochastic process.

Abstract The question of whether a selected psychological pattern precedes or follows the onset of coronary heart disease has served as a vehicle for a discussion of the fundamental issue, namely, the ability to draw causal inferences from observed associations in cross-sectional studies. The possibility of an independent contribution of the psychological pattern to the development of coronary disease, hence a possible etiological role, has been clarified and its implications have been illustrated The crucial distinctions between “predictive” and “etiologic” stochastic models have been reviewed. When such models are used to predict phenomena, the validity of their underlying assumptions is not mandatory. However, when stochastic models are used to explore etiologic relationships, their value depends on the validity of the underlying assumptions. In addition, the users of formal mathematical models must exercise caution to avoid the pitfall of excluding relevant knowledge available from epidemiologic observation. To do so may prevent selection of the most likely inferences to explain particular causal mechanisms.
GLUTATHIONE S-TRANSFERASE IN HORMONAL CARCINOGENESIS

Abstract Treatment with testosterone propionate (TP) and diethylstilbestrol (DES) or TP and estradiol (E2) for 8–9 months causes development of leiomyosarcomas in the vas deferens or uterus of Golden Syrian hamsters at a frequency of 100%. In males, treatment with estrogens alone results in renal tumors, fatal within 6 months. No leiomyosarcomas have been detected after treatment with estrogens alone, perhaps due to this high mortality rate. In tissue culture, treatment with the glucocorticoid (GC) triamcinolone acetonide (TA) results in an increased expression of a μ-class glutathione S-transferase (GST) (hGSTYBX). We have characterized this induction as a secondary response, i.e. requiring new protein synthesis. Here we describe homologies to known transcription factor-binding sites in the hGSTYBX promoter which may be involved in the induction event. hGSTYBX is a member of a superfamily of detoxification enzymes, induced by genotoxic compounds and reactive oxygen species (ROS). We also describe the effects of several known inducers of other GST family members on hGSTYBX. While implicated in many chemotherapeutic-resistant tumors, GST enzymes have not yet been characterized as a functional agent in hormonal carcinogenesis. This latter possibility is the focus of our investigations. To study the effects of hormone treatment on GST levels in vivo, we have developed a polyclonal antibody to hGSTYBX, and conducted immunohistochemistry on tissues from control and treated animals. Treatment with TP and E2 causes a loss of hGSTYBX expression in the epithelium of the vas deferens. We hypothesize that the loss of this protective enzyme leaves the cells vulnerable to the genotoxic effects of estrogen or estrogenic metabolites.
Studies on the influence of sulfur compounds on molybdenum toxicity in rats.

Abstract 1. 1. The influence of methionine, cystine, sodium thiosulfate, and sodium sulfate on molybdenum toxicity in rats was studied. 2. 2. When the sulfur-containing compounds were included in the toxic diet, there was a definite improvement of the enzymatic anomaly observed in molybdenum toxicity. 3. 3. Growth was also improved by the incorporation of these compounds in the toxic diet.
The shift-effect in retinal ganglion cells of the rhesus monkey

McIlwain's periphery effect [7, 1, 5, 6] and the shift-effect of Krfiger and Fischer [2, 4, 6] are elicited by moving patterns, projected outside and at a long distance from the receptive field of retinal ganglion cells. The shift effects studied in the cat's retinal ganglion cells [4, 6] and lateral geniculate neurons [2] point to a visual information processing which is different from that performed by the classical receptive field mechanism and requires long range neuronal connections in the retina. So far, these effects were reported for cats only. This research report gives the first description of the shift effect in the monkey's retinal neurons. In the present experiments the monkeys faced a projection screen. Artificial pupils 5 mm in diameter and contact lenses checked by retinoscopy were used. During the recordings both eyes were open. Extracellular spikes from axons of retinal ganghon cells have been recorded in the optic tract using the same surgical preparation, anesthetics, muscle relaxation and optical stimulation as in cats (for detailed description see [4]). 79 optic tract fibres have been recorded from two adult rhesus monkeys and in 63 of these the receptive fields could be located and classified as 40 on-center and 23 off-center neurons: In all these 63 neurons we observed phasic discharges following grating shifts in the periphery. These responses were elicited by eae displacement of a grating well outside the receptive field. An example is shown in Fig. la. The receptive field of this on-center neuron was adequately illuminated by a steady bright spot of 1.8 deg. in diameter separated by a large dark surround from the moving grating as indicated at the right of Fig. la. (Stationary area 40 deg. in diameter; amplitude of displacement, 2 deg. ; velocity of displacement, 400 deg./see). Under these conditions the response latencies were about 50 ms. In most neurons an adequate steady visual stimulus was necessary to obtain the shift-effect, i.e7 bright spots of suitably chosen size against a dark surround for on-center neurons, dark spots against a bright surround for off-center neurons, provided a steady background activation on which the shift response appears. In a homogeneous field of brightness or darkness the shift-effect was almost absent or at least weak. Reversing brightness and darkness in the stationary field illumination ("inadequate illumination") abolished the shift-effect in all units tested and in two neurons we observed a weak inhibitory shift-effect. Thirteen neurons whose receptive fields could not be located and which therefore could not be activated showed no shift-effect under homogeneous illumination. This does not prove, however, that they had no shift-effect.
Biogenesis and characterization of histone messenger RNA in HeLa cells.

Abstract Histone messenger RNA in HeLa cells does not contain the large poly(A) segment found in the majority of mRNA molecules. Associated perhaps causally with this finding, the exit time from nucleus to cytoplasm is less for histone mRNA than for the generality of mRNA. Although the histone mRNA has these differences from other mRNA molecules, it may still derive from a higher molecular-weight precursor since it continues to increase in cytoplasmic polyribosomes for several minutes after the cessation of RNA synthesis.
A Validated System for Simulating Common Carotid Arterial Flow In Vitro: Alteration of Endothelial Cell Response

Pulsations in blood flow alter gene and protein expressions in endothelial cells (EC). A computer-controlled system was developed to mimic the common carotid artery flow waveform and shear stress levels or to provide steady flow of the same mean shear stress in a parallel plate flow chamber. The pseudo-steady state shear stress was determined from real-time pressure gradient measurements and compared to the Navier–Stokes equation solution. Following 24 h of steady flow (SF: 13 dyne/cm2), pulsatile arterial flow (AF: average=13 dyne/cm2, range=7–25 dyne/cm2) or static conditions, heme oxygenase-1 (HO-1) and prostaglandin H synthase-2 (PGHS-2) mRNA and protein expressions from human umbilical vein endothelial cells were measured. Relative to steady flow, pulsatile arterial flow significantly attenuated mRNA upregulation of HO-1 (SF: 7.26±2.70-fold over static, AF: 4.84±0.37-fold over static; p < 0.01) and PGHS-2 (SF: 6.11±1.79-fold over static, AF: 3.54±0.79-fold over static; p < 0.001). Pulsatile arterial flow (4.57±0.81-fold over static, p < 0.01) also significantly reduced the steady-flow-induced HO-1 protein upregulation (7.99±1.29-fold over static). These findings reveal that EC can discriminate between different flow patterns of the same average magnitude and respond at the molecular level.
Some physical and chemical properties of albumin esterase and albumin from mouse serum

Abstract 1. 1. A pH and ionic strength gradient over DEAE-cellulose is described for the separation of the principal arylesterase (aryl-ester hydrolase, EC 3.1.1.2) (albumin esterase) from mouse serum. Rechromatography over Sephadex G-200 was done to remove some small polypeptides and macromolecules which eluted coincidently with albumin esterase on DEAE-cellulose. 2. 2. Microdensitometer tracings of acrylamide gels showed that such preparations contained less than 5% other serum proteins. At pH 8.9 the electrophoretic mobility of albumin esterase in acrylamide gel is slightly greater than that of mouse albumin. 3. 3. The s 20 value of albumin esterase is approx. 4.4. S. This data, as well as the chromatographic property of albumin esterase in Sephadex, suggested that the molecular weight of albumin esterase is approx. 70 000. 4. 4. The amino acid compositions of mouse albumin and albumin esterase were determined. They differ significantly in their content of cysteine, glycine, alanine, methionine, and isoleucine.
The long-term outcome of a personal network-oriented HIV prevention intervention for injection drug users: The SAFE study

Social influence processes have been found to affect numerous drug and health-related behaviors. We postulated that by using a network-oriented intervention it may be possible to capitalize on social influence processes to reduce human immunodeficiency virus (HIV) risk behaviors. The present study used an experimental study design for delivering a psychoeducational acquired immunodeficiency syndrome (AIDS) preventive intervention to injection drug sharing networks. Participants were recruited from the ALIVE study, an epidemiological study in Baltimore. In the present paper we examine the self-reported behavioral outcomes of 117 injection drug users 18 months after the baseline interview. HIV seronegative experimental participants reported significantly less frequent needle sharing and less injecting of heroin and cocaine than controls. In multiple logistic regression models of HIV seronegative participants, there was a significant negative association between assignment to the experimental group and the HIV-related behaviors of needle sharing and sharing of cookers in the prior 6 months; controls were 2.8 times more likely than experimentals to report needle sharing and were 2.7 times more likely to report sharing cookers. The results of this 18-month follow-up suggest that among injection drug users network-oriented interventions may be a promising approach to HIV prevention.
Srcasm Modulates EGF and Src-kinase Signaling in Keratinocytes

The Src-activating and signaling molecule (Srcasm) is a recently described activator and substrate of Src-family tyrosine kinases (SFKs). When phosphorylated at specific tyrosines, Srcasm associates with Grb2 and p85, the regulatory subunit of phosphoinositide 3-kinase; however, little is known about the role of Srcasm in cellular signaling. Data presented here demonstrate that epidermal growth factor (EGF) receptor ligands promote the tyrosine phosphorylation of endogenous and adenovirally transduced Srcasm in keratinocytes, and that increased levels of Srcasm activate endogenous SFKs, with a preference for Fyn and Src. In addition, Srcasm potentiates EGF-dependent signals transmitted by SFKs in keratinocytes. Tyrosine phosphorylation of Srcasm is dependent on growth factors and the activity of EGFR and SFKs. Increased Srcasm expression enhances p44/42 mitogen-activated protein kinase activity and Elk-1-dependent transcriptional events. Elevated Srcasm levels inhibit keratinocyte proliferation while promoting specific aspects of keratinocyte differentiation. Lastly, Srcasm levels are decreased in human cutaneous neoplasia. Collectively, these data demonstrate that Srcasm plays a role in linking EGF receptor- and SFK-dependent signaling to differentiation in keratinocytes.
GROWTH AND SURVIVAL OF Clostridium perfringens DURING CONSTANTLY RISING TEMPERATURES

Growth and survival of a composite of various strains of Clostridium perfringens was monitored in autoclaved ground beef exposed to constantly rising temperatures increased at rates analogous to those used in beef cookery. Cooking rates from 4.1°C/hr to 12.5°C/hr were examined. Mean generation times (MGT35-52) were determined between 35° and 52°C. the temperature range at which most growth took place. The MGT35-52°C values ranged from 13 min (6.0°C/hr) to 30 min (12.5°C/hr). The most rapid growth rates (MGTmrg) at the rising temperature rates examined were essentially identical at about 8 min. At a constant temperature of 41°C, strain NCTC 8238 exhibited a generation time of 7.1 min. Data characterized growth and survival of C. perfringens during rising temperatures. These data can be used for future growth studies in particular food systems.
Flows of concentrated suspensions through an asymmetric bifurcation

Flows of concentrated suspensions at low Reynolds number through an asymmetric T-junction bifurcation composed of rectangular channels are studied experimentally using nuclear magnetic resonance imaging. In contrast to the unequal division of a uniform concentration material, the suspension and the neutrally buoyant, noncolloidal particles are almost equally partitioned between downstream branches, and motion of particles across the dividing stream surface is deduced to occur at the bifurcation. We attribute the rearrangement of particles to enhanced spreading of high concentration (and therefore high local viscosity) regions of the suspension toward the side branch. The partitioning is accompanied by lateral asymmetry in the concentration and velocity profiles of the downstream branches, although the inlet profiles are symmetric. In the spanwise direction, inhomogeneous concentration distributions that develop upstream persist throughout the inlet and downstream channels. Overall, the fractions of the flow rate and cross-sectional area flowing into the side branch vary slightly with bulk particle volume fraction. Also, inertial effects likely cause an observed shift of the dividing streamline toward the side branch as the flow rate increases, while the flow rate and particle flux fractions entering the side branch hardly change. Finally, directional asymmetry is observed between diverging and converging flows.
Amphetamine response and relapse risk after depot neuroleptic discontinuation.

Twenty-five schizophrenic outpatient subjects in a depot neuroleptic discontinuation study received an amphetamine challenge approximately 6 weeks after their last dose. Only five of these showed greater than three-point increases in positive symptoms on the BPRS, and all five relapsed within 30 days of the challenge. The 20 with less than three-point increases in positive symptoms showed extremely variable stability, relapsing from 20–>600 days after the challenge. Thus, increase in positive symptoms after amphetamine may identify a group at risk for rapid relapse after neuroleptic discontinuation, but lack of such a response gives little prognostic information.
A cost and outcomes comparison of a novel integrated pediatric air and ground transportation system.

Abstract Background The purpose of this study is to compare air transportation of critically ill pediatric patients with a mixed air-ground transportation system by evaluating timeliness, safety, and cost. The setting was a tertiary care "hub" center with three outlying-referral "spoke" facilities. Study design Our study included 96 children transported between June and December 1997, with 45% constituting surgical admissions and 55% medical admissions. Data collected at the outlying facilities, en route, and at our institution included vital signs, laboratory values, and Glasgow coma scores. We evaluated transport time, transport cost, Pediatric Risk of Mortality scores, and Pediatric Index of Mortality of the children during transportation using ANOVA statistical analysis. We also compared adverse events in transportation, total hospital length of stay, and mortality at 24 and 72 hours in both the air and ground transport groups to determine differences in predicted and observed mortality. Results A total of 96 children were transported (48% by ground and 52% by air) between June and December 1997. The time at the referring facility was significantly shorter in the ground group than in the air group (air, 55.4 minutes versus ground, 36.7 minutes, p Conclusions We have demonstrated that a "hub-and-spoke" ground transportation system supplements air transportation in a safe, timely, and cost-effective manner.
Brain-derived neurotrophic factor conditional knockouts show gender differences in depression-related behaviors.

Background Indirect evidence suggests that loss of brain-derived neurotrophic factor (BDNF) from forebrain regions contributes to an individual's vulnerability for depression, whereas upregulation of BDNF in these regions is suggested to mediate the therapeutic effect of antidepressants. Methods We have tested this hypothesis by generating two independent lines of conditional BDNF knockout mice in which the BDNF gene is deleted selectively in forebrain. Results We show that male conditional knockouts exhibit hyperactivity but normal depression-related behaviors. In contrast, female conditional knockouts display normal locomotor activity but a striking increase in depression-like behavior. We also demonstrate that loss of BDNF in both male and female mice attenuates the actions of the antidepressant desipramine in the forced swim test. Conclusions These gender differences in depression-related behaviors in BDNF conditional knockout mice provide direct evidence for a role of BDNF in depression. The results also support the view that forebrain BDNF may be essential in mediating antidepressant efficacy.
Angiotensin II receptor antagonists: A new approach to blockade of the renin-angiotensin system

A-II exerts its activity on various target tissues by binding to its receptors. The discovery of local RASs and A-II receptors within various tissues has generated interest in the clinical usefulness of RAS inhibition by directly blocking the action of A-II at the receptor level. Different A-II receptor subtypes have been identified and subsequently termed AT1 and AT2. AT1-receptor subtypes are the predominant receptor subtypes existing in most organs and, by coupling to a transmembrane G protein, seem to be the main subtypes participating in the vasoactive responses of A-II. Saralasin, a peptide with specific A-II receptor-antagonistic activity, had limited practical long-term usefulness as a result of its short half-life, significant agonistic properties, and lack of oral bioavailability. The discovery of simple benzyl-substituted imidazoles, which possess weak but highly selective A-II receptor antagonistic properties, led to the development of losartan (DuP 753). Losartan is a potent, orally active, specific, competitive nonpeptide A-II receptor antagonist that appears to be an effective antihypertensive agent both in animal studies and in preliminary clinical trials. The therapeutic usefulness of losartan, however, is not limited to its antihypertensive effects. The potential benefits of A-II receptor antagonists include roles in postmyocardial infarction therapy, slowing A-II-induced cardiac hypertrophy, 154, 155 slowing the progression of heart failure, preventing postangioplasty restenosis, and in slowing the progression of renal disease. Furthermore, losartan, a selective A-II type 1 (AT1) receptor antagonist, has also been a valuable pharmacologic probe for studying the mechanism of A-II stimulation of its receptors. A-II receptor antagonism appears to be as effective as ACE inhibition in the treatment of hypertension and other pathologic processes that involve the RAS and may offer an alternative to those patients who cannot tolerate ACE inhibitors because of their side effects.
An In-Water Contrast Measuring Device

AN IN -WATER CONTRAST MEASURING DEVICER. B. Patterson and F. W. HeemstraNaval Research LaboratoryCode 8420Washington, D. C. 20375AbstractThe depth at which a Secchi disc disappears provides a measure of visible range which is not appli-cable to many practical situations. Most other methods of determining in -water visibility measure oneor more water parameters, which are used in a theoretical or empirical model to predict visible range.The proposed Contrast Meter measures the apparent contrast of a known target at a fixed distance andrelates the loss of contrast to visible range by empirical measurements. This instrument lends itselfto remote sensing and could be adapted for measuring contrast loss in other turbid mediums. A prototypeinstrument has been built and tested.IntroductionThe problems of measuring and predicting the range of visibility in water are not simple. Some ofthe difficulties encountered are enumerated by Sorenson and Honey.(1) "It should be noted that the prob-lem of visibility through the atmosphere has been investigated for more than 300 years without achieve-ment of either generally accepted definitions - e.g., visibility, contrast - or convenient instrumentationfor the measurement and prediction of visibility. Probably the underwater visibility and instrumentationproblem will not be soon solved in a completely general way." The problem of in -water visibility has beenstudied for over 100 years, during which time there have been numerous attempts to provide usable measure-ment systems. This paper discusses some of these attempts and then describes an instrument which ap-proaches the problem differently.BackgroundIn order to be visible an object must exhibit contrast. That is, the object must emit or reflecteither more, less, or a different colored light than the background against which it is to be seen.
Cytotoxicity of a New Root Canal Filling Material on Human Gingival Fibroblasts

This study evaluated the cytotoxicity of the root canal sealing materials Resilon and Epiphany versus gutta-percha, Grossman's sealer, Thermaseal, and Sealapex. Using human gingival fibroblasts the fibroblasts cultures were incubated for either 1 or 24 h to test the cytotoxicity after freshly mixing or after 24 h of setting. Fibroblasts were then stained with trypan blue, to determine number of dead cells. Data were analyzed using ANOVA and t tests. Resilon was similar to gutta-percha and the control. Epiphany was less cytotoxic than Grossman's sealer at both the 1 and 24 h time periods. Epiphany was more cytotoxic than Sealapex at the 1-h time period but less cytotoxic at the 24 h time period. These results indicated that Resilon had a lower cytotoxicity and that Epiphany was more cytotoxic than conventional materials.
Extending the Television Brand: An Examination of Why Consumers Use Broadcast Network Web Sites

Framed by the technology acceptance and customer-based brand equity (CBBE) models, this study investigated how audiences intend to use broadcast television network Web sites. Drawing upon the results of a survey (N = 178), this research found that perceived ease of use and perceived enjoyment significantly influence intent to use broadcast Web sites. Findings also reveal that CBBE plays a significant role as a mediator between motivations and behavioral intention to use broadcast networks' Web sites. It is concluded that as the medium of television evolves, networks' Web sites should be conduits for sustained brand allegiance and broadcasters should make more strategic use of their Web sites.
Training and assessment in obstetrics: the role of simulation

Simulation is becoming an integral part of the training and assessment of obstetricians. Given the variety of manual skills that must be learned, awake patients and high-risk environment, obstetrics is uniquely suited for simulation. Simulation provides opportunities to rehearse and learn from mistakes without risks to patients. The use of simulation can help overcome some limitations of the current medical education and practice environment, including work-hour limitations and concerns for patient safety. Both low- and high-fidelity simulation models can be used to accomplish educational goals. Basic and advanced skills as well as the management of obstetric emergencies are amenable to simulation. For a simulation programme to be successful, one must identify the learner and the skills that are to be learned. In the future, simulation will be more available and realistic and will be used not only for education, but also for ongoing assessment of providers.
Lipid monolayer dilatational mechanics during microbubble gas exchange

Lipid-coated microbubbles are being developed for a variety of biomedical applications in imaging and therapy. In order to better understand microbubble stability and in vivo fate, it is important to elucidate the mechanical properties of the phospholipid monolayer shell. Here, a gas exchange method was used to probe the monolayer dilatational properties of individual microbubbles. The microbubbles were observed to grow and then dissolve back to the initial diameter in a manner that depended on both microbubble size and lipid composition. The experimental diameter–time curves were analyzed with a gas transport model employing the energy barrier theory for monolayer permeation to account for gas species, acyl-chain length and variable surface pressure. Model analysis allowed computation of apparent surface tension as a function of area, which exhibited a characteristic “flag-shaped” curve comprising three regimes: (i) linear elastic expansion, (ii) nonlinear relaxation during expansion and (iii) linear elastic compression. A comparison of fitted model parameters suggested a molecular mechanism involving expansion, rupture and lipid lateral diffusion in the monolayer shell during growth and lipid domain growth and packing during dissolution. Overall, these results provide new physical insights into lipid monolayer behavior that are relevant to understanding microbubble stability and medical performance.