cssi/SciSciGPT-SciSciNet huggingface dataset:
Crystal and molecular structures of native and CTP-liganded aspartate carbamoyltransferase from Escherichia coli

Atomic models representing the electron density of two crystalline forms of aspartate carbamoyltransferase from Escherichia coli are reported here. The unliganded form (R32 crystal symmetry) and the CTP-liganded form (P321 crystal symmetry) have been refined independently at resolutions of 3.0 a and 2.8 A, respectively, each to a crystallographic R-factor of 27%. The molecular models include at least 95% of the theoretical number of atoms for the aspartate Carbamoyltransferase molecule based on chemical sequence information. We provide details of the refinement process for the two structures, and an evaluation of the accuracy of the molecular models. For the most part, the regulatory and catalytic chains of the unliganded enzyme and the CTP-liganded form are in similar conformations. Large conformational differences in the CTP and native forms exist, however, specifically in the region of CTP binding to the regulatory chain. In addition, a segment of ten amino acid residues, which includes Lys83 and Lys84 of the catalytic chain, is disordered in the CTP-liganded form, in contrast to the native structure, where the same residues have refined well into density. Each catalytic monomer of aspartate carbamoyltransferase is in contact with three catalytic chains and two regulatory monomers. Each regulatory monomer borders on one other regulatory chain and two catalytic chains. The catalytic trimera are in contact in the hexamer; residues important to homotropic effects and catalysis (Tyr165 and Tyr232) are integral parts of the interface. We present a thorough survey of interface regions, cataloging polar interactions between sidechains throughout the molecule. We discuss, in context with the present structures, the chemical modifications and mutations of the enzyme. Highlighted specifically are Cys47, Tyr165 and Tyr232, Lys83, Lys84, Trp209 and Trp279 and Gly128, residues of demonstrated importance to the catalytic of regulatory function or aspartate carbamoyltransferase. The spatial arrangement of “active site” residues argues for a catalytic pocket shared between two monomers within catalytic subunit.
The Role of Anthropology in Nursing Education

I see the principal role of anthropology in nursing as expanding the way nurses view their subject matter: humans. I work toward that goal at the University of Washington School of Nursing through my faculty duties, and at other schools, hospitals, and community agencies through giving lectures and consulting. In addition, 43 nurses have graduated with Master's degrees from the program in cross-cultural nursing at the University of Washington; I expect that through teaching and role modeling in their various positions they convey anthropology's unique perspective in nursing to their students and colleagues.
DENDRITIC CRYSTAL GROWTH DYNAMICS

With considerable NASA support, the scientific community has learned much in recent decades about the process of dendritic crystal formation, particularly as an example of steady-state pattern formation. Recently, efforts here and elsewhere have shifted towards the study of the timevarying aspects of the process. This paper will discuss the recent observations of the Transient Dendritic Solidification Experiment (TDSE). Data will be presented on the differences and similarities in the process by which two critical growth parameters, the growth rate and the tip radius of curvature, evolve as they approach steady state. This transient stage in the growth process is integral to many real-world industrial processes, and therefore a better understanding of it will serve as an important element of future industrial process models.
Crisis theory, the application for treatment, and dependency.

Abstract The application for treatment was defined as a crisis—a period of psychological disequilibrium and high anxiety—in that it is an application for a major role change affecting the core self. Crisis theory predicts that the closer the intervention is to the crisis, the greater the success of the intervention. Specifically, it was predicted that the shorter the delay between the client's application for treatment and the first scheduled interview, the more successful the intervention in terms of the interview's actually taking place and the likelihood of the client's improving at the termination of therapy. Using the first definition of success, the prediction was confirmed in three different types of treatment agencies. With improvement as the definition of success, the prediction was given encouraging support in two types of agencies. An argument was made that a necessary but not sufficient condition for a successful crisis intervention is that a client's dependency and affiliative needs be satisfied. Research directions for understanding dependency and affiliation in relation to crisis interventions and the intake process were indicated.
Harnessing frequency diversity in wi-fi networks

Wireless multicarrier communication systems transmit data by spreading it over multiple subcarriers and are widely used today owing to their robustness to multipath fading, high spectrum efficiency, and ease of implementation. In this paper, we use real measurements to show there is significant frequency diversity in Wi-Fi channels, and propose a series of techniques to explicitly harness such frequency diversity. In particular, we leverage the Channel State Information (CSI), which captures the SNR on each subcarrier to (i) map symbols to subcarriers according to their importance, (ii) effectively recover partially corrupted FEC groups and facilitate FEC decoding, and (iii) develop MAC-layer FEC to offer different degrees of protection to the symbols according to their error rates at the PHY layer. We further develop a rate adaptation approach that works together with these optimization schemes. Our trace-driven simulation and testbed experiments based on USRP clearly demonstrate the effectiveness of our approaches.
Efficient Stochastic Modeling for Large and Consolidated Insurance Business: Interest Rate Sampling Algorithms

Abstract One of the challenges of stochastic asset/liability modeling for large insurance businesses is the run time. Using a complete stochastic asset/liability model to analyze a large block of business is often too time consuming to be practical. In practice, the compromises made are reducing the number of runs or grouping assets into asset categories. This paper focuses on the strategies that enable efficient stochastic modeling for large and consolidated insurance business blocks. Efficient stochastic modeling can be achieved by applying effective interest rate sampling algorithms that are presented in this paper. The algorithms were tested on a simplified asset/liability model ASEM (Chueh 1999) as well as a commercial asset/liability model using assets and liabilities of the Aetna Insurance Company of America (AICA), a subsidiary of Aetna Financial Services. Another methodology using the New York 7 scenarios is proposed and could become an enhancement to the Model Regulation on cash flow testing, th...
Regulated release of multiple peptides from the bag cell neurons ofAplysia californica

The bag cell neurons of Aplysia californica synthesize and store large amounts of peptides derived from the egg-laying-hormone (ELH) neuropeptide precursor. Different sets of peptides derived from the amino- and carboxyl-terminal regions of the prohormone possess unique biological activities, and are packaged in distinct sets of secretory granules. We report here quantitative measurements of the amounts of the peptide products stored in and released from the bag cell neurons using high pressure liquid chromatography (HPLC) and amino acid composition analysis. These studies demonstrate that both the autocrine acting bag cell peptides (BCPs) and ELH are released coincident with electrical activity in the bag cell cluster. The composition of the released peptide mixture is similar to that stored in the bag cells. ELH and other carboxy-terminal derived peptides are most often present at 5-fold greater levels than the BCPs. These results provide further insight into the use of multiple chemical messengers by the bag cell neurons.
Gamma-secretase: from pathogenesis to therapeutics.

Background Presenilin (PS) is the catalytic subunit of g-secretase and mutations in this protein cause familial Alzheimer’s Disease (FAD). Moreover, g-secretase has emerged as an appealing drug target for Alzheimer’s disease (AD) and cancer due to its central role in the generation of Ab peptides and the regulation of Notch signaling. g-Secretase is composed of at least four subunits: PS, Nicastrin, Aph1 and Pen2; with a total of 19 putative transmembrane domains.
RENAL TUBULAR ACIDOSTS (RTA) IN A PATIENT WITH PARTIAL PERIHERAL RESISTANCE TO THYROID HORMONES (TV)

RENAL TUBULAR ACIDOSTS (RTA) IN A PATIENT WITH PARTIAL PERIHERAL RESISTANCE TO THYROID HORMONES (TV)
Technology agreements and industrial relations in Belgium

Belgium has a very developed system of national collective bargaining and as a result, it is one of the few countries with a national technology agreement. An analysis revealed that this agreement was not used very much. This article looks at the use and importance of technology agreements for unions.
Cf‐252 particle desorption mass spectrometry of photo‐oxidized polystyrene

Cf-252 particle (plasma) desorption mass spectra are presented for polystyrene surfaces before and after exposure in air to UV light. The photo-oxidation produces changes observed in both positive and negative ion spectra. Oxygen incorporation produces a slight increase in intensity of m/z+ 18 and 19 (H2O+ and H3O+) and m/z− 16 and 17 (O− and OH−). Also, the relative intensity of m/z+ 91 decreases after photo-oxidation and is interpreted as the formation of a bond alpha to the benzene ring. New peaks are detected at m/z+ 226, 227 and 331, and are tentatively assigned to hydroperoxide-containing structures. Other changes in the spectrum include the increase in intensity of m/z+ 77 and 105 arising from easily ionized fragments of the oxidation products of polystyrene.
Reciprocity Law Failure In Green Sensitive X-Ray Films

Reciprocity law failure was measured for four brands of medical X-ray films exposed with intensifying screens. Three of the films are green light sensitized for use in combination with green light emitting rare-earth screens. These films showed larger reciprocity failure effects than one conventional blue sensitive film, Dupont Cronex-2. The development conditions had a small effect on reciprocity failure. The effect of reciprocity failure on the measurements of physical image quality parameters is discussed.© (1977) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Chloride attachment negative chemical ionization mass spectra of organophosphate pesticides

This paper reports the dichloromethane-mediated negative chemical ionization mass spectra of 17 organophosphorus pesticides having the general structure (RO)2P(S)S(CH2)nR (R = Me, Et or iso-Pr; n = 0, 1, or 2; R′ contains one or more heteroatoms) and demeton-O (O, O, S-triethylphosphorothioate). In all cases the spectra are simple and characteristic of the compound in question. In general, the [(RO)2PS2]− anion was the base peak, and a chloride attachment ion was invariably present; this ion allows molecularly specific confirmation of the compound. Molecules having stable potential anions in the R′ moiety, e.g. carbophenthion and phencapton, selectively form the stable anion. Dissociative capture or nucleophilic displacement on the R group of methyl and ethyl esters increased in prominence at higher temperatures; [M – R]− was the base peak in the negative chemical ionization mass spectrum of dimethoate (R = Me, n = 1, R′ = C(O) NHMe) above 200°C.
Ascidian prickle regulates both mediolateral and anterior-posterior cell polarity of notochord cells.

Abstract The ascidian notochord follows a morphogenetic program that includes convergent extension (C/E) followed by anterior-posterior (A/P) elongation [1–4]. As described here, developing notochord cells show polarity first in the mediolateral (M/L) axis during C/E, and subsequently in the A/P axis during elongation. Previous embryological studies [3] have shown that contact with neighboring tissues is essential for directing M/L polarity of ascidian notochord cells. During C/E, the planar cell polarity (PCP) gene products prickle ( pk ) and dishevelled ( dsh ) show M/L polarization. pk and dsh colocalize at the notochord cell membranes, with the exception of those in contact with neighboring muscle cells. In the mutant aimless ( aim ), which carries a deletion in pk , notochord morphogenesis is disrupted, and cell polarization is lost. After C/E, there is a dynamic relocalization of PCP proteins in the notochord cells with dsh localized to the lateral edges of the membrane, and pk and strabismus ( stbm ) at the anterior edges. An A/P polarity is present in the extending notochord cells and is evident by the position of the nuclei, which in normal embryos are invariably found at the posterior edge of each cell. In the aim mutant, all appearances of A/P polarity in the notochord are lost.
Variations in plasma zinc in older men and women

The study evaluated the biological and analytical variance in plasma zinc from 36 adults 60–88 yr of age. Blood samples were taken by finger-prick from each subject on d 1, 2, 3, 8, and 15. Days 1, 2, and 3 were selected to describe daily variation; 1, 8, and 15 were selected to describe weekly variation. Plasma Zn was analyzed by flame atomic absorption using a microinjection technique. Variation was partitioned into analytical, intraindividual, and interindividual components using analysis of variance. The interindividual variability was generally greater than the intraindividual variability. The variability for plasma zinc was about 30% and was substantially greater than reported for younger populations. This variability could not be attributed to the covariates examined, including zinc intake from food and supplements, serum albumin, and C-reactive protein. The variability would affect the accuracy of plasma zinc status based on a blood sample collected on a single day. With the microtechnique used in this study, 8 sample days would be needed to estimate plasma Zn with 95% confidence level and 20% level of accuracy.
Relaxation of catch in a molluscan smooth muscle. II. Effects of serotonin, dopamine and related compounds.

Abstract 1. 1. Serotonin analogs and certain catecholamines were tested on thin muscle bundles isolated from the anterior byssus retractor muscle of Mytilus edulis L. 2. 2. By comparing the structure of agents which relaxed catch with that of agents which had no relaxing action in any concentration it is possible to clarify the general structural requirements for agents mediating relaxation.
Nocturnal blood pressure non-dipping, posttraumatic stress disorder, and sleep quality in women.

Women with posttraumatic stress disorder (PTSD) have poor sleep quality and increased risk of cardiovascular disease (CVD). Non-dipping of nocturnal blood pressure may be an explanatory factor for the relationship between sleep and CVD found in previous research. The current study was designed to determine if non-dipping nocturnal blood pressure was associated with trauma exposure, PTSD diagnosis, PTSD symptoms, and sleep quality in a sample of women. Participants completed 24 hours of ABPM and self-report questionnaires. Non-dipping was defined as less than 10% reduction in blood pressure during sleep. The frequency of non-dippers did not differ by diagnostic status (d = .15). However, non-dippers endorsed more traumatic event categories (d = .53), more PTSD hyperarousal symptoms (d = .53), poorer overall sleep quality (d = .59), more frequent use of sleep medication (d = .62), greater sleep-related daytime dysfunction (d = .58), and longer sleep onset latencies (d = .55) than dippers. Increased attentio...
Effects of confinement on relaxation in glass-formers : Magnitude, trends and dependence on the Kohlrausch exponent

We show that the Adam-Gibbs theory cannot by itself explain the reduction of τ α and T g when a supercooled liquid is confined in nano-meter pores. However, when combined with the coupling model, the modified theory can explain the finite-size effects of small molecule glass-formers in pores and ultra thin polymer films. The modified theory also predicts two additional behaviors. First, magnitude of the finite-size effect is larger in liquids that have smaller exponent, β, in the Kohlrausch expression for the structural relaxation of the unconfined liquid at Tg. Second, the dependence of the structural relaxation time of the liquid on T g /T becomes increasingly weaker with decreasing pore size. These predicted behaviors are found in the experimental data. A previously proposed mechanism for the glass transition reduction in thin freely-standing polymer films [K.L. Ngai et al., J.NonCryst.Solids 235-237, 435 (1998)] is revisited. Recent Monte Carlo simulation results support the mechanism.
Management of candiduria.

Abstract Candiduria, due to Candida albicans, Candida glabrata and other organisms, has increased in frequency due the use of broad-spectrum antibacterials, immunosuppressive agents and other factors. The optimal management of candiduria is unknown due to an undlear definition of fungal urinary tract infection and the lack of well-designed clinical trials. Removal of urinary catheters, ruling out obstruction/stones and documenting presence of post-void residuals are useful in the management of candiduria. Amphotericin B bladder irrigants and oral fluconazole may be used in certain patients who are high risk or with persistence of candiduria after removal of the urinary catheter.
Hydrogen-Bond Directed Structural Selectivity in Asymmetric Heterocyclic Cations

The notion that the best hydrogen-bond donor preferentially interacts with the best hydrogen-bond acceptor has been explored in the synthesis and structural characterization of 12 salts based on asymmetric 2-aminopyrimidinium cations: 2-amino-4-methoxy-6-methylpyrimidinium 2-fluorobenzoate, 2-amino-4-methoxy-6-methylpyrimidinium 3-chlorobenzoate, 2-amino-4-methoxy-6-methylpyrimidinium 3-nitrobenzoate, 2-amino-4-methoxy-6-methylpyrimidinium benzoate, 2-amino-4-methoxy-6-methylpyrimidinium 3-N,N ‘(dimethyl)aminobenzoate, 2-amino-4-methoxy-6-methylpyrimidinium methylene-hydrogensuccinate hydrate, bis(2-amino-4-methylpyrimidinium) fumarate, 2-amino-4-methylpyrimidinium 3-fluorobenzoate, 2-amino-4-methylpyrimidinium nitrate, 2-amino-4-methylpyrimidinium 3-chlorobenzoate, 2-amino-4-methylpyrimidinium 2-methyl-hydrogenmaleate, and 2-amino-4-chloro-6-methylpyrimidinium 3,5-dinitrobenzoate toluene0.4. In each structure, the −COO- acceptor consistently seeks out the −N−H+ donor generating the most important interm...
A standard to calibrate γ-ray spectrometers for gaseous samples

Abstract A standard is described which can be used to calibrate Ge(Li) detectors for measuring radioactive gaseous samples in 33-mL glass spheres. The method of source preparation can be applied to other types of counting bottles. The γ-ray energies of this source, 226 Ra plus progeny, range from 46 to 1765 keV. The uncertainties in the emission rates for the various γ rays in the source are estimated to be about 3%. (6) The source has a half life of 1600 y and coincidence-summing corrections are minor.
People with heart failure and home health care resource use and outcomes

Aims and objectives. Patients with heart failure represent a common patient population in home health care, yet little is known about their outcomes. Background. Patients with heart failure, regardless of site of care, experience substantial numbers of rehospitalisations in the United States. Home health care is a common postacute care service for patients with heart failure. Design. Retrospective analysis. Methods. The study employed a large administrative data base from 2003 – the Outcomes and Assessment Information Set, which is required for all US Medicare and Medicaid patients receiving home health care. Participants. There were 145 191 patients with a primary diagnosis of heart failure represented in the data set. The outcomes of interest were the trajectory of care (point of entry and discharge from home health care), hospitalisation, length of stay and change in functional status. Results. Almost three-quarters (73·9%) of patients entered home health care following a hospital stay. Nearly two-thirds (64%) remained at home at discharge from home health care. Approximately 15% of patients are hospitalised during the home health care episode, most often for symptoms consistent with exacerbation of the heart failure, if a reason could be identified. The average length of stay in home health care was 44 days. There was only a small improvement in functional status: 0·50 points for activities of daily living and 0·57 points for instrumental activities of daily living. Similar small improvement occurred in depressive symptoms, 0·68. Relevance to clinical practice. There may be room for improvement in these outcomes with more recent evidence that suggests strategies for reducing hospitalisation and improving patient functional status abilities. Yet, the chronic progressive nature of heart failure may also provide a limiting factor in the outcomes that can be attained.
A study of metabolic cooperation utilizing human mutant fibroblasts

Abstract Incubation of HGPRT− (hypoxanthine guanine phosphoribosyltransferase) and BCD− (branched chain amino acid decarboxylase) human cells with sonicate prepared from normal cells resulted in partial restoration of the activity in the deficient cells. The data suggest that the restoration is due to the absorption of factors of proteinaceous nature, presumably the appropriate enzymes. The absorption is dependent on time after transfer and on concentration. The half-life of the absorbed activity is similar to the half-life of the comparable activity in normal cells. The use of the phenomenon to various enzymatic studies as well as its possible in vivo role is discussed.
Cardiac myocyte remodeling mediated by N-cadherin-dependent mechanosensing

Cell-to-cell adhesions are crucial in maintaining the structural and functional integrity of cardiac cells. Little is known about the mechanosensitivity and mechanotransduction of cell-to-cell interactions. Most studies of cardiac mechanotransduction and myofibrillogenesis have focused on cell-extracellular matrix (ECM)-specific interactions. This study assesses the direct role of intercellular adhesion, specifically that of N-cadherin-mediated mechanotransduction, on the morphology and internal organization of neonatal ventricular cardiac myocytes. The results show that cadherin-mediated cell attachments are capable of eliciting a cytoskeletal network response similar to that of integrin-mediated force response and transmission, affecting myofibrillar organization, myocyte shape, and cortical stiffness. Traction forces mediated by N-cadherin were shown to be comparable to those sustained by ECM. The directional changes in predicted traction forces as a function of imposed loads (gel stiffness) provide the added evidence that N-cadherin is a mechanoresponsive adhesion receptor. Strikingly, the mechanical sensitivity response (gain) in terms of the measured cell-spread area as a function of imposed load (adhesive substrate rigidity) was consistently higher for N-cadherin-coated surfaces compared with ECM protein-coated surfaces. In addition, the cytoskeletal architecture of myocytes on an N-cadherin adhesive microenvironment was characteristically different from that on an ECM environment, suggesting that the two mechanotransductive cell adhesion systems may play both independent and complementary roles in myocyte cytoskeletal spatial organization. These results indicate that cell-to-cell-mediated force perception and transmission are involved in the organization and development of cardiac structure and function.
Primitive ultrafine matrix in ordinary chondrites

Ultrafine matrix material has been concentrated by sieving and filtering disaggregated samples of six ordinary chondrites of different classes. This component(s), 'Holy Smoke' (HS), is enriched in both volatile, e.g. Na, K, Zn, Sb, and Pb, as well as refractory elements, e.g. W and REE; however, the element ratios vary greatly among the different chondrites. SEM studies show that HS contains fragile crystals, differing in composition, and apparently in gross disequilibrium not only among themselves but also with the major mineral phases and consequently thermodynamic equilibration did not occur. Thus HS must have originated from impacting bodies and/or was inherent in the 'primitive' regolith. Subsequent impact brecciation and reheating appears to have altered, to varying degrees, the original composition of this ultrafine matrix material. Recent 'cosmic dust' studies may indicate that HS still exists in the solar system. Survival of such delicate material must be considered in all theories for the origin of chondrites.
Ozone-induced inhibition of theophylline elimination in rabbits: Effect of age and sex

The effect of age and sex on the elimination of theophylline in New Zealand White rabbits was investigated following exposure to 0.3 ppm of ozone (O3) for 3.75 hr/day over 5 consecutive days. Animals were given air alone 5 to 7 days before and after the 5 days of O3 exposure. The elimination half-life of theophylline was significantly (p = 0.004) prolonged on Days 1 and 5 of O3 exposure in the rabbits greater than 2 years old, with no effect being seen in those 3 to 4 months old. No O3-induced change was seen in the apparent volume of distribution to account for the observed change in theophylline elimination half-life. The female rabbit in particular demonstrated this age-related effect; while in the male, variability prevented the observed difference from reaching significance. The results indicated inhibition of theophylline elimination by O3 in the rabbit depends on age and sex.
Rate of respiratory excretion of dimethylsulfide in cats given dimethylsulfoxide.

Abstract Cats given dimethylsulfoxide intravenously exhale 3% of the administered dose as the volatile metabolite dimethylsulfide within 5 hours. The rate of respiratory excretion of dimethylsulfide appears to be limited by the rate of its metabolic production, rather than by respiratory factors. The liver does not appear to be a major site of the reduction of dimethylsulfoxide to dimethylsulfide because hepatectomy does not significantly affect the rate of dimethylsulfide excretion. Dimethylsulfoxide is reduced in vitro to dimethylsulfide by cysteine and glutathione, suggesting a nonenzymatic conversion.
Effect of Flood on Agricultural Wages in Bangladesh: An Empirical Analysis

Summary This paper analyzes the effects of riverine floods on agricultural wages in Bangladesh. Drawing upon the district-wise monthly data over 1979–2000, we model wages as a dynamic process. We find that floods have positive implications for wages in the long run. In flood months, however, agricultural wages decline in the inundated districts. We obtain difference-in-difference estimates to show that the magnitude of impact of flood depends on the relative flood proneness of a district and the relative severity of flood conditions. Our results indicate that favorable demand and supply conditions in the agricultural labor market can mitigate the impact of disasters on wages in Bangladesh.
MEGACOLON ASSOCIATED WITH ADMINISTRATION OF AN ANTICHOLINERGIC DRUG IN A PATIENT WITH ULCERATIVE COLITIS: REPORT OF A CASE.

In treating patients with megacolon, the clinician must first consider the various conditions that predispose to this complication, including a drug effect. Although not common, severe dilatation of the colon has been reported in association with administration of certain anticholinergic agents, particularly in patients with acute ulcerative colitis. This report describes the onset of megacolon and megaloureters in a patient treated for diarrhea with an anticholinergic drug (Sorboquel). Subsequently, the patient was found to have ulcerative colitis. The case is unusual, in that the presence of ulcerative colitis was unsuspected and the megacolon was “nontoxic.”
A reevaluation of the cause of acute hypercalcemia following intravenous administration of lead acetate.

The effect of intravenous (i.v.) injection of lead acetate (15 or 30 mg/kg) was studied in young adult male rats. The reaction of lead with rat plasma to produce colloidal material containing both calcium and phosphate was demonstrated both in vitro and in vivo. This material could be centrifuged down at 25,000 ×g from plasma aliquots to which lead had been added or from plasma samples obtained as early as 5 min after i.v. lead injection. The hypercalcemia and hyperphosphatemia reached their peak rapidly after lead injection, and even at the higher dose level these lasted less than 6 h.45Ca and32P were injected at times varying from 1 to 8 days prior to lead administration. Plasma radioactivity levels rose with their stable counterparts without affecting plasma nuclide specific activity. Lead uptake on bone surfaces could be detected within 5 min of injection, and continued to accumulate for at least 6 h. It is concluded that although lead attaches to bone surfaces, the hypercalcemia and hyperphosphatemia are caused by the direct interaction of lead with calcium and phosphate in solution in plasma. The formation of the colloidal material lowers ionic calcium and phosphate. In vivo, calcium and phosphate are immediately withdrawn from extravascular sources returning plasma concentrations to their initial value. The source of at least the calcium is believed to be bone. The attachment of lead to bone surfaces does not in itself release significant amounts of calcium and phosphate into blood.
The Late Open-Coronary Artery Hypothesis: Dead, or Not Definitively Tested?

Continued controversy surrounds the optimal therapeutic approach to the patient who does not undergo percutaneous coronary intervention (PCI) early during acute myocardial infarction, when ischemic myocardium could still be salvaged, and who presents days to weeks after the acute event with persistent total occlusion of the infarct-related coronary artery. The Occluded Artery Trial (OAT) demonstrated no measurable effect of PCI on outcome. There were trends, however, for more frequent reinfarctions and a higher estimated 4-year cumulative primary event rate. Because patient selection included only patients with 1- or 2-vessel coronary disease, and because interventionalists were permitted to perform PCI on the noninfarct-related arteries, >85% of patients in the intervention group had no coronary arteries with significant obstructions after PCI, a situation that would cause the functional regression of existing collaterals. If subsequent plaque rupture and total occlusion of any of the 3 coronary arteries occurred (expected in 5% to 15% of patients with acute coronary syndromes over the first 1 to 2 years), the impaired collateral flow immediately after new acute occlusion would predispose to greater myocardial injury and therefore greater patient risk, which could explain the negative effects of the OAT study, and which raises the disturbing possibility that complete revascularization in patients with recent acute coronary syndromes could possibly lead to greater risks in the following 1 to 2 years in those patients who experience recurrent acute coronary occlusion. Conversely, late opening of the culprit artery in patients with multivessel coronary disease, without all arteries being patent, may favorably alter late outcomes. In conclusion, the therapeutic implications of the OAT study apply to a specific patient cohort; whether late opening of the culprit artery improves or impairs outcome appears critically to depend on the specific cohort treated.
Thermochemical Investigations of Associated Solutions: Comparison of PAH-chlorobutane Versus PAH-dichlorobutane Equilibrium Constants calculated from Solubility Data

Abstract Experimental solubilities are reported for anthracene dissolved in binary solvent mixtures containing 1,4-dichlorobutane with n-heptane, n-octane, cyclohexane and methylcyclohexane at 25°C. Results of these measurements, combined with estimates for the excess Gibbs free energies of the binary solvents, are used to evaluate the equilibrium for a presumed anthracene-dichlorobutane molecular complex using the Extended NIBS model. The calculated equilibrium constant is compared to published values for anthracene-chlorobutane and pyrene-dichlorobutane. Differences in the values for the various polycyclic aromatic hydrocarbons (PAHs) and mono/dichlorobutanes are rationalized at the molecular level in terms of individual microscopic equilibrium constants for distinguishable association species.
Error-rate analysis for multirate DS-CDMA transmission schemes

We analyze and compare the error performance of a dual-rate direct-sequence code-division multiple-access (DS-CDMA) system using multicode (MCD) and variable-spreading gain (VSG) transmission in the uplink. Specifically, we present two sets of results. First, we consider an ideal additive white Gaussian noise channel. We show that the bit-error rate (BER) of VSG users is slightly lower than that of MCD users if the number of low-rate interferers is smaller than a specific threshold. Otherwise, they exhibit similar error performance. Second, we look at multipath fading channels. We show that with diversity RAKE reception, the VSG user suffers from a larger interference power than the MCD user if the channel delay spread is small. The reverse is true for a large delay spread. However, a larger interference power in this case does not necessarily lead to higher error probability. Essentially, our results for both cases show that: 1) in addition to the signal-to-interference ratio (SIR), the difference in error performance between the two systems strongly depends on the distributions of multiple-access and multipath interference; 2) for practical cellular communications, performances for both systems are expected to be similar most of the time.
Personal computers and behavioral observation: An introduction

Some fundamental aspects of observational data are outlined, and some basic issues in implementation of small computers in observational research are discussed.
Psoriasis and Cardiovascular Risk: Strength in Numbers Part 3.

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."
Nonlinear feedback systems perturbed by noise: steady-state probability distributions and optimal control

We describe a class of nonlinear feedback systems perturbed by white noise for which explicit formulas for steady-state probability densities can be found. We show that this class includes what has been called monotemperaturic systems in earlier work and establish relationships with Lyapunov functions for the corresponding deterministic systems. We also treat a number of stochastic optimal control problems in the case of quantized feedback, with performance criteria formulated in terms of the steady-state probability density.
Producers' complex risk management choices

Producers have a wide variety of risk management instruments available, making their choice(s) complex. The way producers deal with this complexity can vary and may influence the impact that the determinants, such as risk aversion, have on their choices. A recently developed choice bracketing framework recognizes that producers are unable to evaluate all alternatives simultaneously and that to manage a complex task, they often group or bracket individual alternatives and their consequences together in choice sets. Data on 1,105 U.S. producers show that producers do not use all available combinations of risk management tools and that the influence of the determinants of producer’s risk management decisions are not necessarily the same across risk management strategies within and across bracketing levels. The findings may help resolve puzzling results on the role that well-known determinants of risk management behavior have on producers’ choices, extending knowledge on producers’ risk management behavior. Further, the findings have managerial implications for policy makers and agribusiness companies that provide risk management services. [EconLit citations: M000, G1000, Q130] � c 2008 Wiley-Liss, Inc.
Determine the quality of human embryonic stem colonies with laser light scattering patterns

With the prompt developments of regenerative medicine, the potential clinical applications of human embryonic stem cells have attracted intense attention. However, the labor-intensive and complex manual cell selection processes required during embryonic stem cell culturing have seriously limited large-scale production and broad applications. Thus, availability of a label-free, non-invasive platform to replace the current cumbersome manual selection has become a critical need. A non-invasive, label-free, and time-efficient optical platform for determining the quality of human embryonic stem cell colonies was developed by analyzing the scattering signals from those stem cell colonies. Additionally, confocal microscopy revealed that the cell colony morphology and surface structures were correlated with the resulting characteristic light scattering patterns. Standard immunostaining assay (Oct-4) was also utilized to validate the quality-determination from this light scattering protocol. The platform developed here can therefore provide identification accuracy of up to 87% for colony determination. Our study here demonstrated that light scattering patterns can serve as a feasible alternative approach to replace conventional manual selection for human embryonic stem cell cultures.
Antibiotic prescribing and outcomes following treatment of symptomatic urinary tract infections in older women.

Objective To describe antibiotic prescribing patterns for the treatment of urinary tract infections (UTI) among older women female long-term care facility residents and evaluate factors associated with adverse outcomes Methods Study Design: Population-based retrospective cohort study. Population and sampling frame: All female residents of Olmsted County, Minnesota, aged 65 years and older, who were treated for urinary tract infections during calendar year 1996 were included in the study. Data collection: Subjects’ complete medical records were reviewed and abstracted. Data collected included age, weight, serum creatinine, antibiotic treatment including dosage and duration, as well as retreatment and adverse drug events. Results A total of 196 subjects, ranging in age from 65 to 98 years, were diagnosed with UTI during calendar year 1996. Forty-four subjects were nursing home residents, and 152 resided in the community. The odds of prolonged antibiotic therapy (7 days or more) were 83 times higher among nursing home residents (Odds ratio = 82.7, 95% Confidence Interval, 11.1–617.7). The odds of receiving treatment for 10 days or longer were 5 times higher among nursing home residents compared to community subjects. The odds of underlying renal impairment necessitating dosage reduction were 3.6 times higher among nursing facility residents. Nursing facility residents were 7.3 times more likely to be treated with excessive dosages of antibiotics, 9.6 times more likely to experience adverse drug events, and 2.6 times more likely to receive retreatment for persistent or recurrent symptoms within one week of antibiotic discontinuation, compared to community subjects with UTI. Conclusions Nursing home residents with UTI are treated for longer durations than community elderly. They experience a greater likelihood of receiving antibiotics in excessive dosage, a greater likelihood of adverse drug events, and a greater likelihood of retreatment compared with community subjects with UTI.
Stages of oocyte development in the pipefish, Syngnathus scovelli.

Oocyte development occurs in a temporal and spatial pattern in the ovary of the pipefish, Syngnathus scovelli. Cytological observations combined with [3 H]thymidine uptake and cell culture were used as criteria to identify six stages of oocyte development in this species. Stage I-Oogonia, found within the germinal ridge. Stage II-Oocytes in primary growth, subdivided into (1) chromatin-nucleolus oocytes in early prophase I of meiosis, also found within the germinal ridge, and (2) perinucleolar oocytes, which possess multiple nucleoli and are within definitive follicles (the Balbiani vitelline body is the main cytoplasmic component in these latter oocytes). Stage III-Oocytes distinguished by the appearance of cortical alveoli, the vitelline envelope, and lipid. Stage IV-Vitellogenic oocytes, which accumulate yolk proteins and possess primary, transitional, and mature yolk spheres. Stage V-Maturational oocytes, which are competent to undergo final meiotic maturation in vivo and in response to the steroid 17 α-hydroxy-20β-dihydroprogesterone in vitro. Stage VI-Ovulated mature eggs, which are present in the ovary lumen and are capable of being fertilized. These studies provide a staging series for oogenesis and oocyte development in the pipefish and relate these stages to the unusual ovary in this animal.
Cultures, computers, and communication: evaluating models of international online production

The spread of online communication technologies has brought with it new perspectives on international communication. Now, with the Internet, email, and application service providers, interacting with coworkers an entire hemisphere away can be almost as easy as interacting with coworkers in the same building. As a result of the "leveling of distance" created by online communication technologies, new kinds of international business models have been proposed; models that attempt to reduce production costs while maintaining product quality. However, some of these models fail to account for cultural differences that could cause communication problems in international online exchanges. The article examines how one particular international online production model, production facilities that never close, could encounter cultural communication problems if participants involved were not aware of certain cultural communication expectations, specifically those related to the cultural concept of "face".
That Enlightenment Question Again

Sandall’s complaint that the Enlightenment is in danger is not new as it repeats a long standing complaint about “the betrayal of the intellectuals”. But the danger today is not from either the Muslim world or from the marginalized academics who pursue an anti-liberal multicultural agenda that belittles the Western liberal tradition. In the United States the menace comes from the much more powerful far right that has abandoned America’s Enlightenment tradition. It is time for academics to start teaching students what that tradition is all about, and why it needs to be defended, but spreading fear about weak and divided Muslim societies is not the way.
High-resolution structures of the Landers fault zone inferred from aftershock waveform data

SUMMARY High-frequency body waves recorded by a temporary seismic array across the surface rupture trace of the 1992 Landers, California, earthquake were used to determine fault-zone structures down to the seismogenic depth. We first developed a technique to use generalized ray theory to compute synthetic seismograms for arbitrarily oriented tabular low-velocity fault-zone models. We then generated synthetic waveform record sections of a linear array across a vertical fault zone. They show that both arrival times and waveforms of P and S waves vary systematically across the fault due to transmissions and reflections from boundaries of the low-velocity fault zone. The waveform characteristics and arrival-time patterns in the record sections allow us to locate the boundaries of the fault zone and to determine its P- and S-wave velocities independently as well as its depth extent. Therefore, the trade-off between the fault-zone width and velocities can be avoided. Applying the method to the Landers waveform data reveals a low-velocity zone with a width of 270‐360 m and a 35‐60 per cent reduction in P and S velocities relative to the host rock. The analysis suggests that the low-velocity zone extends to a depth of ∼7 km. The western boundary of the low-velocity zone coincides with the observed main surface rupture trace.
Online high‐precision δ2H and δ18O analysis in water by pyrolysis

A method for online simultaneous delta(2)H and delta(18)O analysis in water by high-temperature conversion is presented. Water is injected by using a syringe into a high-temperature carbon reactor and converted into H(2) and CO, which are separated by gas chromatography (GC) and carried by helium to the isotope ratio mass spectrometer for hydrogen and oxygen isotope analysis. A series of experiments was conducted to evaluate several issues such as sample size, temperature and memory effects. The delta(2)H and delta(18)O values in multiple water standards changed consistently as the reactor temperature increased from 1150 to 1480 degrees C. The delta(18)O in water can be measured at a lower temperature (e.g. 1150 degrees C) although the precision was relatively poor at temperatures <1300 degrees C. Memory effects exist for delta(2)H and delta(18)O between two waters, and can be reduced (to <1%) with proper measures. The injection of different amounts of water may affect the isotope ratio results. For example, in contrast to small injections (100 nL or less) from small syringes (e.g. 1.2 microL), large injections (1 microL or more) from larger syringes (e.g. 10 microL) with dilution produced asymmetric peaks and shifts of isotope ratios, e.g. 4 per thousand for delta(2)H and 0.4 per thousand for delta(18)O, probably resulting from isotope fractionation during dilution via the ConFlo interface. This method can be used to analyze nanoliter samples of water (e.g. 30 nL) with good precision of 0.5 per thousand for delta(2)H and 0.1 per thousand for delta(18)O. This is important for geosciences; for instance, fluid inclusions in ancient minerals may be analyzed for delta(2)H and delta(18)O to help understand the formation environments.