cssi/SciSciGPT-SciSciNet huggingface dataset:
Conversion of Phosphatidylcholine to Phosphatidylglycerol with Phospholipase D and Glycerol

When phosphatidylcholine (PtdCho) is acted upon by the enzyme phospholipase D (PLD) in the presence of glycerol and water, at least two products can arise: phosphatidic acid (PtdOH) from hydrolysis and PtdGly from transphosphatidylation. Commercial PLD preparations from Streptomyces chromofuscus, Streptomyces sp., and cabbage were examined for their ability to selectively promote PtdGly formation in a two phase aqueous-organic solvent system. Factors examined were enzyme amount, pH, glycerol concentration, and the type of organic solvent. The reaction of PtdCho to give products such as PtdGly was followed by HPLC using a stationary phase consisting of a polymerized poly (vinyl alcohol) on silica gel with ELSD. The identities of all products were confirmed by retention times and HPLC-MS analyses. Under all tested conditions PLD from S. chromofuscus gave at most a 15% yield of PtdGly. Higher amounts of added glycerol inhibited this PLD. Nearly quantitative conversion to PtdGly was obtained with cabbage PLD when the mol ratio of glycerol to PtdCho was at least 64 (mol water/glycerol = 105). With PLD from Streptomyces sp. a nearly quantitative yield of PtdGly was obtained when the mol ratio of glycerol to PtdCho was at least 5.3 (mol water/glycerol = 1,266), demonstrating that this PLD had a higher selectivity for glycerol than cabbage PLD. When the glycerol concentration was very low, the level of PtdOH increased, and cardiolipin (diphosphatidylglycerol) was generated. The highest mol ratio PtdGly to PtdOH was observed when the solvents isopropyl ether or dichloromethane were used.
Design and performance analysis of an adaptive FIR Kalman equalizer

Abstract In this paper a discrete-time model of a communication channel is developed and the parameters of the channel are updated as operating conditions change. The Stochastic Newton Algorithm (SNA) is employed in the adaptation process, which is a stabilized version of the Extended Kalman Filter (EKF). The performances of the SNA and EKF are compared through a number of computer simulation studies, in terms of their accuracy, speed and memory requirements. The SNA's performance is superior, compared to the EKF, but the design procedure of the SNA is fairly complicated. The algorithm also requires somewhat difficult tuning procedures, additional memory space and computation time.
Volcanic sequence in the Marysvale region in southwest‐central Utah

As a consequence of the detailed investigation of the alunite and other mineral deposits of the Marysvale Region in southwest-central Utah, opportunity was afforded to map and study the succession of volcanic rocks that underlie most of this area. The Marysvale Region is part of a large area of volcanic rocks, which occupies much of the High Plateaus of Utah (Fig. 1). It is believed that the Marysvale Region covers sufficient area to furnish an adequate sample of this volcanic area, and, though horizontal variations are known to occur, the study may serve as a guide as to what may be expected in other parts of the area. The chemical analyses are the most completely representative of any ever taken in this part of Utah, and they furnish a basis of comparison within the High Plateaus and with other areas in Utah.
Multi-label literature classification based on the Gene Ontology graph.

Background The Gene Ontology is a controlled vocabulary for representing knowledge related to genes and proteins in a computable form. The current effort of manually annotating proteins with the Gene Ontology is outpaced by the rate of accumulation of biomedical knowledge in literature, which urges the development of text mining approaches to facilitate the process by automatically extracting the Gene Ontology annotation from literature. The task is usually cast as a text classification problem, and contemporary methods are confronted with unbalanced training data and the difficulties associated with multi-label classification.
Further examples of endocardial cushion defect in production of a cardiac anomaly complex

Summary Three cases of congenital heart diseasemanifesting a complex which has been accounted for as a failure or delay in endocardial cushion development have been described anatomically and discussed. This discussion has tended to point to (1) the critical period in development of basic structural anomalies of the heart, (2) the anatomical and embryologic explanation of the three cases presented, and (3) the need of careful post-mortem examination of specimens, particularly in those cases where a history or suggestion of cardiac or cardiovascular irregularity has existed.
Effects of iron impurities in mechanical alloying using steel media

Mechanical alloying, a high-energy ball-milling technique, is now widely used for preparing alloy powders with metastable phases (crystalline or amorphous). The technique, however, may contaminate the powder with material eroded from the vial and milling media. We report on the analysis and effects of iron contamination on Al[sub 25]Ge[sub 75] powders that we prepared by mechanically alloying mixtures of aluminum and germanium powders, using different mechanical alloying apparatuses.
Tumor necrosis factor‐α: A potentially neurodestructive cytokine produced by glia in the human glaucomatous optic nerve head

Tumor necrosis factor-alpha (TNF-alpha) mediates a range of cellular responses, which have potentially detrimental consequences that affect multiple cell types. To determine whether TNF-alpha contributes to glaucomatous optic neuropathy, we have studied the expression of this cytokine and its receptor, tumor necrosis factor receptor-1 (TNF- R1), in human glaucomatous optic nerve heads from patients with different stages of disease using double labeling fluorescence immunohistochemistry. We have also investigated the ability of this cytokine to induce nitric oxide synthase (NOS-2) in cultured human optic nerve astrocytes by immunocytochemistry and immunoblot. Normal tissue showed constitutive expression of TNF-R1 in the vasculature of the optic nerve heads but no positive labeling for TNF-alpha. In the glaucomatous optic nerve heads, the expression of both TNF-alpha and TNF-R1 were apparently upregulated, primarily in glial fibrillary acidic protein (GFAP)-positive astrocytes, and appeared to parallel the progression of optic nerve degeneration. In eyes with severe glaucomatous damage, some HLA-DR positive microglia also contained TNF-alpha and TNF-R1. In the most severely damaged optic nerve heads, the axons of the retinal ganglion cells contained TNF-R1 and, therefore, are direct targets for neurodegeneration caused by TNF-alpha. In vitro astrocytes constitutively express TNF-R1 and TNF-alpha stimulation induces expression of NOS-2. We hypothesize that TNF-alpha contributes to the progression of optic nerve degeneration in glaucoma by both a direct effect on the axons of the retinal ganglion cells and by inducing NOS-2 in astrocytes.
Influence of algal and suspended sediment concentrations on the feeding physiology of the hard clam Mercenaria mercenaria

Short-term laboratory feeding experiments were conducted to determine the response of the hard clam Mercenaria mercenaria (L.) (32 mm in mean shell length) to increasing sediment concentrations. Clams were fed mixed suspensions of Pseudoisochrysis paradoxa (50 and 150 cells μl-1) and bottom sediments (0 to 44 mg l-1). Algal ingestion rate deelined with increasing sediment loads. This resulted primarily from a reduction in clearance rate, which declined by 0.08 l h-1 g-1 (1.3%) for every 1 mg l-1 increase in sediment load. This reduction was of similar magnitude for juvenile (13 mm) clams. At the algal concentrations tested, pseudofaeces production was intermittent and inconspicuous below about 10 mg silt l-1. Loss of algae in pseudofaeces increased with increasing sediment loads; however, even at the highest silt and algal concentrations, clams lost a maximum of only 18% of the algae cleared from suspension. Thus, pseudofaeces production is not expected to cause significant loss of algal food at the sediment concentrations normally encountered in the natural environment (≦ ca 40 mg silt l-1). Absorption rate of total organic matter remained constant, at least up to silt concentrations of 20 mg l-1. Experiments using dual 51Cr:14C-formaldehyde-labelled sediment indicated that clams were able to counteract the dilution of algae by absorbing a considerable fraction (21 to 22%) of detrital sedimentary organics. Absorption efficiency of pure P. paradoxa ranged from 82% at 50 cells μl-1 to 58% at 150 cells μl-1. Integration of physiological rate measurements suggests that at moderate to high algal concentrations (≧300 μg Cl-1), growth improvement by the addition of silt, documented in mussels, surf clams and oysters, is unlikely to occur in M. mercenaria. It is suggested that a suspension-feeding bivalve's success in maximizing its energy gain in a turbid environment depends on the combination of two features: a high selection efficiency and a high rate of pseudofaeces production. It is proposed that species which regulate ingestion primarily by producing pseudofaeces are better adapted to cope with high suspended sediment loads than species such as M. mercenaria, which control ingestion mainly by reducing clearance rate.
DFT Study of the Adsorption of Chlorosilanes on the Si(100)-2 × 1 Surface

We have used density functional theory along with the cluster approximation to investigate the adsorption of chlorinated silanes on the Si(100)-2 × 1 surface. We have calculated the energetics for ...
Theoretical Models for the Specific Adhesion of Cells to Cells or to Surfaces

There are many examples in which the adhesion of cell to cell or of cell to substrate is mediated by bonds between specific molecules. In some cases, the molecules are well understood. Consider, for example, a solution containing cells such as red blood cells which do not ordinarily stick to one another. Suppose that molecules, such as antibody molecules, which have two or more sites for binding to specific determinants on the cell surface are introduced into the solution. A single molecule may be able to bind simultaneously to determinants on two cells and thus a sufficient concentration of such molecules may agglutinate the cells. Such agglutination of red cells by specific antibodies is commonly used for determining blood types. In other experiments the agglutination of various cells by protein molecules called lectins1 has been analysed. These studies generated considerable excitement about a decade ago when it was found that tumor cells are more readily agglutinated2 than normal cells.
Preliminary examination of oxidative stress in juvenile spring Chinook salmon Oncorhynchus tshawytscha of wild origin sampled from transport barges

Migrating juvenile wild Chinook salmon Oncorhynchus tshawytscha, collected and loaded onto transport barges at Lower Granite Dam on the Snake River, were sampled from barges at John Day Dam, 348 km downstream, at 5 day intervals beginning in late April and ending in late May. An increase in lipid peroxidation and decrease in vitamin E in liver were observed from early to late in the barge transportation season. These changes seemed unrelated to changes in plasma cortisol or corresponding glucose levels, which declined from early to late in the season, or the concentration of n-3 highly unsaturated fatty acid (HUFA) concentrations in tissue but may be related to water temperature, which increased during the transport season, or other changes associated with the parr–smolt transformation. Journal compilation © 2009 The Fisheries Society of the British Isles No claim to original US government works
Tyrosine Phosphorylation-Mediated Signaling Pathways in Dictyostelium

While studies on metazoan cell proliferation, cell differentiation, and cytokine signaling laid the foundation of the current paradigms of tyrosine kinase signaling, similar studies using lower eukaryotes have provided invaluable insight for the understanding of mammalian pathways, such as Wnt and STAT pathways. Dictyostelium is one of the leading lower eukaryotic model systems where stress-induced cellular responses, Wnt-like pathways, and STAT-mediated pathways are well investigated. These Dictyostelium pathways will be reviewed together with their mammalian counterparts to facilitate the comparative understanding of these variant and noncanonical pathways.
Adaptive multivariable closed-loop control of blood glucose concentration in patients with Type 1 Diabetes

Closed-loop control of blood glucose concentration is an alternative treatment for Diabetes patients by automatically controlling their blood glucose level. Recursive time-series models are found to be powerful tool for prediction and control of glucose concentration. However, the stability of such models cannot be guaranteed by regular identification methods. In this paper, we use a constrained optimization method for stability of models. Generalized predictive controller (GPC) is used to close the loop. Physiological signals are used and a multivariable model is created that also includes insulin on-board information to prevent hypoglycemia events. Seven experiments with 3 different patients are done. Results show GPC with constrained identification method and physiological signals can regulate blood glucose concentration successfully.
Geomagnetic data safely stored

A recent article in Eos (May 13, 1997, p. 199), “Conference on the Magnetization of the Oceanic Crust Steers Future Research,” made reference to certain geomagnetic data held by the U.S. Navy. The authors expressed concern for the safekeeping of the data mentioned above. Their concern was apparently predicated on the belief that these data are being stored only on aging magnetic tapes. This is not the case. The geomagnetic data, held by the Naval Oceanographic Office, are stored in multiple copies on several different stable media, including on-line storage in our relatively new Integrated Database Management System.
Application of the RADPEER™ Scoring Language to Interpretation Discrepancies Between Diagnostic Radiology Residents and Faculty Radiologists

Purpose The objectives of this study were to assess the rate of discrepancies between radiology residents and faculty radiologists at an academic hospital using the RADPEER ™ scoring language and to determine if a correlation existed between assigned RADPEER score (2, 3, or 4) and the clinical significance of the error. Methods Over 19 months, preliminary resident interpretations were graded using the RADPEER scoring system. A retrospective review of discrepant cases was performed to assess the percentage of discrepancy, change in clinical management, and identification of error patterns. Results Of 2,255 preliminary interpretations, 29 discrepancies (1.29%) were judged to be potentially clinically significant. Of these, 14 (0.62%) resulted in immediate changes in clinical management. Discrepancies assigned RADPEER scores of 3 or 4 were significantly more likely to be judged clinically significant than those assigned scores of 2 (54.5% of 33 studies graded 3 or 4 and 7.7% of 142 studies graded 2, P Conclusions Discrepancy rates in this study are comparable with previously reported data for discrepancies between attending radiologists and those between attending radiologists and residents data. A significant correlation was observed between increasing RADPEER scores and the clinical significance of discrepancies. This study supports the use of the RADPEER scoring language as both a resident quality assurance measure and an educational tool for quality improvement.
An Investigation of the Effect of Graphite Degradation on Irreversible Capacity in Lithium-ion Cells

An Investigation of the Effect of Graphite Degradation on the Irreversible Capacity in Lithium-ion Cells Laurence J. Hardwick * , Marek Marcinek a* , Leanne Beer, John B. Kerr*, Robert Kostecki b,* Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA a Electrochemical Society Active Member Present address: The Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland b Corresponding author: r_kostecki@lbl.gov, tel: (1) 510 486 6002, fax: (1) 510 486 7303
The kinetics of electrocrystallization of tellurium and cadmium telluride at the glassy carbon surface

Abstract This article describes the first comparative examination of the kinetics of nucleation/growth of Te and CdTe at a glassy carbon electrode surface. A TeO2/H2SO4 electrodeposition matrix, to which requisite amounts of Cd2+ were added, was utilized for this study. Cyclic voltammetry, with scan rate as a variable, permitted examination of changes in the fine-structure of the Te deposition peak as Cd2+ ions were introduced. Using the voltammograms as a reference point, a series of potential-jump experiments were conducted from +0.50 V (vs. Ag/AgCl) to final potentials spanning the −0.22 to −0.35 V range. Thesei-t transients were compared for the Cd2+-absent and Cd2+-present Te deposition systems respectively. Concurrent coulometry was also conducted to enable comparison of i,Q and t at various characteristic points of thei-t profiles in the two cases. An initial current decay to a minimum comprised both double-layer charging and Te nucleation. The rising portion of the i-t transients could be fitted to an instantaneous nucleation/2-D growth model in both cases. In this model, the Cd was viewed as being assimilated at the periphery of the expanding Te nuclei. At longer times, nuclei overlap and the onset of diffusion control gave rise to a current maximum and subsequent t −1 2 decay. Reduced-variable plots enabled differentiation of the nucleation mechanism. These new results are finally discussed within the framework of previous fragmentary data for Te nucleation/growth as well as the more detailed studies that exist for anodic semiconductor growth mechanisms.
Leak behaviors of steam generator tube-to-tubesheet joints from room temperature to 320 °C

Abstract To address concerns about excessive leakage from throughwall cracks in nuclear reactor tube-to-tubesheet joints under accident conditions, leak rates were measured experimentally by using tube-to-collar joint specimens and nitrogen gas. Rates were dependent on differential pressure between the tube internal surface and the crevice (i.e., the tube-to-collar interface region) and on temperature. As specimen temperature was raised to 320 °C, leak rates decreased gradually due to changes in gas properties and to differential thermal expansion between the Alloy 600 tubes and the SA508 collars. The leak rates did not change even after repeated temperature excursions to 320 °C, suggesting that thermally induced creep and subsequent contact pressure relaxation is negligible below that temperature. When considering factors that could increase flow resistance, such as oxidation, or debris on top of the tubesheet, the measured leak rates in this work are considered to be conservative. The test results were further used to validate the contact pressure calculation and a leak rate model.
The distribution of disturbance-dependent rare plants in a coastal Massachusetts sandplain : Implications for conservation and management

Abstract Rare plants in coastal New England sandplains are often restricted to anthropogenically disturbed sites including plowed and mowed firelanes at the Manuel F. Correllus State Forest on Martha’s Vineyard. Little is known about pre-colonial rare plant habitat or how modern management impacts these species. To understand the factors influencing rare plant distribution, we examined the influence of vegetation structure, species composition, environmental characteristics and disturbance history on rare plant populations and potential natural habitat in the 2100-ha Forest. We sampled >100, 100 m 2 plots – in firelanes and forested/shrubland areas – and conducted extensive searches for rare plants. Linum intercursum and Scleria pauciflora var. caroliniana were frequent in firelanes including in recently plowed areas, whereas Nabalus serpentarius , Sisyrinchium fuscatum , and Aristida purpurascens generally occurred in isolated, locally-abundant patches in firelanes not plowed for many decades. The former group may be characterized by an ability to rapidly establish following disturbances while the latter may take longer to establish and develop large populations. In some respects, rare plants were associated with environmental conditions reflecting the disturbance histories of sites they occupied (e.g., L. intercursum with lower duff depth and N. serpentarius with greater litter cover/depth). In forests and shrublands undisturbed for decades, rare plants only occurred on well-worn paths. Although scrub oak stands supported conditions more similar to those found in firelanes than other native vegetation types, disturbances – far more severe than those in forests/shrublands of the past century – are probably required to create suitable rare plant habitat in sandplain forests and shrublands.
Asymmetric permeability of vectorized membranes

A membrane with composition gradient shows directionality of transport properties if the local permeability is nonideal and can be represented by an irreducible function of location and pressure or concentration. The diffusion current is larger if the side with larger deviation from ideality is exposed to higher pressure or concentration. According to the theory, asymmetriesΔ up to one and even a little more can be achieved. The rapid saturation, however, very soon sets such a low limit toΔ that even with most extreme composition variation of a continuous membrane no efficient valve action can be expected. As a by-product of the investigation one also finds thatFicks first law is inapplicable to permeant diffusion in nonideal membranes.
Discrete variable representations and sudden models in quantum scattering theory

Abstract An exact formalism in which the scattering problem may be described by sets of coupled equations labeled either by basis functions or quadrature points is presented. Use of each frame and the simply evaluated unitary transformation which connects them results in an efficient procedure for performing quantum scattering calculations. Two approximations are compared with the IOS.
Nuclear magnetic resonance spectra for l > 1 spins in dynamically heterogeneous systems with chemical exchange among environments

Nuclear magnetic resonance spectra for nuclei with spin l > 1 are considered in cases in which the observed nucleus may sample a rotationally immobilized and an isotropic environment that are coupled by a chemical exchange process. Spectra are simulated for the central (1/2, -1/2) transition for a 3/2 nucleus as a function of the concentrations of the two environments and as a function of the exchange rate between them. It is shown that a crucial feature determining the shape of the observable spectra is the spatial extent or the local order in the immobilized phase. In the case for which all rotationally immobilized sites sampled by the exchanging nucleus are identically oriented but where there is a distribution of these microdomain orientations with respect to the magnetic field direction, a powder pattern for the central transition is observed that carries whatever dynamic information may be derived from it. In the fast exchange limit, the width of the powder pattern scales inversely with the concentration of the isotropic environment as usual. In the intermediate exchange regimes, a complex line shape results that may mask the anisotropic character of the spectrum. In the slow exchange limit, superposition of the spectral contributions results; however, if the isotropic environment concentration is significantly larger than the anisotropic environment concentration, the anisotropic contribution is very difficult to detect because of the dynamic range problem and the possibly large difference in the effective line widths. In the case for which the exchanging nucleus samples a considerable distribution of rotationally immobilized site orientations, the anisotropic character of the spectrum is lost and a super-Lorentzian line shape results. These effects are demonstrated experimentally by 35Cl nuclear magnetic resonance spectra obtained on a lamellar liquid crystal that is modified with the addition of a thiolmercurate to provide a site of large quadrupole coupling constant and with cross-linked bovine serum albumin gels.
Irregularities in the X-Ray Background

The X-ray background is a unique tool in having its origin in the redshift range of about unity, and in the availability of all sky coverage. The paper reviews the measurements of isotropy and compares them to what is known about the origin of the X-ray background in terms of discrete sources, a galactic component, and a possible 'truly diffuse' metagalactic emission. Only the 2-10 keV X-ray range is considered in detail. Four irregularities in the distribution of the 2-10 keV X-ray background are identified, three of them being in the angular distribution of surface brightness. Recent results from the Einstein X-ray Observatory have revealed the fourth irregularity, namely, that the extragalactic sources evolve strongly so that half the background arises from beyond a redshift of unity.
Stable transformation of maize: the impact of feeder cells on protoplast growth and transformation efficiency

The importance of cell culture conditions, including the use of feeder cells, on protoplast growth and transformation in maize (Zea mays L.) was investigated. Total GUS activity, measured two days after transformation, was five-fold higher in protoplasts cultured on feeder cells compared to those grown in the absence of feeder cells. Since the specific activity of GUS was only slightly higher in the transformed protoplasts plated over feeder cells, the stimulation in transient gene expression resulted mainly from the improved environment provided by the feeder system. For stable transformation, either PEG treatment or electroporation of protoplasts was used to introduce the neo gene. When PEG was used, over 85% of the putative transformants (resistant to kanamycin) contained the neo gene. The combination of PEG transformation and the optimized cell culture protocol using feeder cells enabled the selection of about 100 stably transformed lines per gFW of cells. Electroporation was less efficient.
Development and psychometric evaluation of the Endometriosis Treatment Satisfaction Questionnaire

To develop and psychometrically evaluate the Endometriosis Treatment Satisfaction Questionnaire, a patient-reported assessment of satisfaction with endometriosis treatment. The Endometriosis Treatment Satisfaction Questionnaire was developed based on the results of five focus groups and three iterative sets of cognitive interviews along with expert opinion and a review of the literature. The psychometric properties were assessed using data collected during a multicenter, randomized, proof-of-concept trial. The development and validation processes followed the guidance recommended by the United States FDA for patient-reported outcome instruments. The Endometriosis Treatment Satisfaction Questionnaire’s reliability, validity, and utility as a measure of patient satisfaction with their endometriosis treatment were supported. The results of the item-level analyses showed no evidence of distributional anomalies or response scale biases. The Endometriosis Treatment Satisfaction Questionnaire is unidimensional, has excellent internal consistency reliability, and discriminates well between known groups. Scores correlated well with other patient-reported outcome measures of endometriosis without being redundant. The Endometriosis Treatment Satisfaction Questionnaire has utility for assessing patient satisfaction with endometriosis treatment and may be useful in clinical trials that are assessing new treatments for endometriosis, especially when deciding between competing treatments or regimens that are found to have similar tolerability and efficacy.
Detoxification with hemabsorption after cardiac arrest does not improve neurologic recovery. Review and outcome study in dogs

We and others hypothesized that noxious substances released after prolonged cardiac arrest from malfunctioning liver, kidneys, or intestine (e.g. bacterial toxins, aromatic amino acids), might hamper recovery of the brain. The highly detoxifying effect of hemabsorption (i.e. hcmoperfusion) with microen-capsulated activated carbon has been demonstrated in other diseases. We used our dog model of ventricular fibrillation cardiac arrest of 15 min (n = 2 × 4) or 12.5 min (n = 2 × 6), reversed by brief (high flow) cardiopulmonary bypass (CPB). In half of the dogs in each insult group, a charcoal filter (HemoKart®) was inserted into the circuit of CPB at low flow, from start of reperfusion to 4 h. Intermittent positive pressure ventilation was to 20 h and intensive care to 96 h after cardiac arrest. Bacterial blood cultures were positive in most of the dogs in both groups 30 min to 20 h after cardiac arrest (but not later) and were uninfluenced by hemabsorption. In the control groups to 4 h after cardiac arrest, serum levels of potentially injurious aromatic amino acids (e.g. phenylalanine, tyrosine) and of branched-chain/aromatic amino acid ratios, remained unchanged. From 12 to 48 h after cardiac arrest, aromatic amino acid levels increased (worsened). The branched-chain/aromatic amino acid ratios changed accordingly in the opposite direction. In the hemabsorption groups to 4 h after cardiac arrest, all amino acid levels were reduced, aromatic amino acids more so than branched-chain amino acids, thus increasing (improving) the ratio, compared with controls (P < 0.01). There was no group difference after discontinuance of hemabsorption at 4 h. Outcome in terms of overall performance categories and neurologic deficit scores from 24 to 96 h and brain histopathologic damage scores 96 h after cardiac arrest, were not significantly different between groups. The lack of a beneficial outcome effect of hemabsorption to 4 h after cardiac arrest does not support the self-intoxication hypothesis. The amino acid levels later after cardiac arrest suggest that more prolonged hemabsorption and more encompassing detoxification treatments, such as plasma phoresis or total body blood washout, might be evaluated.
The effect of a new emergency medicine residency program on patient length of stay in a community hospital emergency department.

Objectives: It is not clear how emergency medicine residents affect emergency department (ED) efficiency. The objective of this study was to determine whether a new emergency medicine residency program affected the lengthof stay (LOS) of patients in a community hospital ED. Methods: A before-anti-after observational study was conducted during a one-year period prior to, and for three years after, the start of a new residency. An additional year's worth of data were collected during the fifth year after the residency started. Patients were excluded if their LOS was less than 30 minutes and they were admitted directly to the hospital. Explanatory variables included scheduled resident and student hours/day; scheduled faculty hours/day; nursing plus clerk hours/day; patients/day; ambulances/ day; and admissions/day. The data were analyzed using descriptive and correlation statistics and regression analysis. Results: Average patient LOS prior to the residency was 122.9 minutes. During the first year of residency, it was 126.6 minutes; second year, 129.9 minutes; third year, 158.9 minutes; and fifth year, 162.4 minutes. There was a positive correlation between LOS and third-postgraduate-year resident (PGY-3) hours (rho = 0.43), and between LOS and PGY-3 hours/patients/day (rho = 0.42). All other correlations were poor [rho < 0.4). Conclusions: In this ED, there was a weak, positive correlation between ED patient length of stay and the presence of PGY-3 emergency medicine residents.
Associative ternary cache for IP routing

A study of a prefix routing cache for Internet IP routing is presented. An output port assignment requires one cache memory access when the assignment is found in cache. The cache array is divided into sets that are of variable size; all entries within a set have the same prefix size. The cache is based on a ternary content addressable memory that matches ones, zeroes and don't care values. Our study shows that an associative ternary cache provides an output port at the speed of one memory access with a very high hit rate. For an 8K entry cache the hit rate ranges from 97.62 to 99.67% on traces of 0.2 to 3.5 million addresses. A port error occurs when the port selected by the cache differs from the port that would have been selected from the routing table. A sampling technique is introduced that reduces the worst port error rate by an order of magnitude (from 0.52 to 0.05%).
Exploring the Elements of Culturally Relevant Service Delivery

This qualitative study included demographic questionnaires, focus groups, and in-depth interviews to gain an understanding of what groups of African American and Caucasian consumers of the Head Start and Fatherhood programs perceived as valued and culturally relevant elements of service delivery. The programs are administered by Total Action Against Poverty in Roanoke, Virginia. Findings include that support, mentorship-role modeling, education, and structure were of particular merit. Implications for culturally congruent service delivery and the need to use this information to inform curriculum development are discussed.
Mechanism of action of thrombin on fibrinogen. On the role of the A chain of bovine thrombin in specificity and in differentiating between thrombin and trypsin.

Abstract Bovine thrombin was immobilized on sepharose 4B through an oxidized sialic acid group on its B chain. The immobilized thrombin was reduced with β-mercaptoethanol in 8 m urea under conditions that were shown to be sufficient to reduce the disulfide bond connecting the A and B chains. The immobilized B chain that remained after the A chain was washed away was allowed to refold, and the disulfide bonds were reoxidized with a mixture of oxidized and reduced glutathione under anaerobic conditions. The refolded immobilized B chain exhibited 15–25% of the tosyl- l -arginine methyl ester esterase activity of the immobilized thrombin and a significant amount of fibrinogen clotting activity. The immobilized B chain behaved qualitatively like immobilized thrombin towards two oligopeptide fibrinogen-like substrates and showed no activity towards lysine or arginine peptide bonds in a fragment of ribonuclease. Since the recovered activity was greater than that computed for a random refolding of seven -SH groups to form three SS bonds, it is concluded that the B chain retains a sufficient number of interacting groups to refold correctly, and it is suggested that prothrombin might fold in localized domains with only weak interactions between domains. The behavior of the B chain towards the substrates tested suggests that the A chain does not play a significant role in determining the catalytic specificity of thrombin or in distinguishing its specificity from that of trypsin.
A comparison of parametric, semi-parametric, and non-parametric approaches to selectivity in age-structured assessment models

Abstract Integrated assessment models frequently track population abundance at age, and hence account for fishery removals using a function representing fishery selectivity at age. However, fishery selectivity may have an unusual shape that does not match any parametric function. For this reason, previous research has developed flexible ‘non-parametric’ models for selectivity that specify a penalty on changes in selectivity as a function of age. In this study, we describe an alternative ‘semi-parametric’ approach to selectivity, which specifies a penalty on differences between estimated selectivity at age and a pre-specified parametric model whose parameters are freely estimated, while also using cross-validation to select the magnitude of penalty in both semi- and non-parametric models. We then compare parametric, semi-parametric, and non-parametric models using simulated data and evaluate the bias and precision of estimated depletion and fishing intensity. Results show that semi- and non-parametric models result in little decrease in precision relative to the parametric model when the parametric model matches the true data-generating process, but that the semi- and non-parametric models have less bias and greater precision when the parametric function is misspecified. As expected, the semi-parametric model reverts to its pre-specified parametric form when age-composition sample size is low but performs similarly to the non-parametric model when sample size is high. Overall, results indicate few disadvantages to using the non-parametric model given the range of simulation scenarios explored here, and that the semi-parametric model provides a selectivity specification that is intermediate between parametric and non-parametric forms.
Comparison of NIR/RED ratio and first derivative of reflectance in estimating algal-chlorophyll concentration: A case study in a turbid reservoir

Abstract The objective of this research was to test the use of the well-documented ratio of near-infrared (NIR; 705 nm) to red (670 nm) reflectance in estimating chlorophyll content in a relatively turbid midwestern reservoir. The results were compared with those obtained by analyzing the first derivative of reflectivity near 690 nm. Data were collected in three different months over a 2-year period, and the characteristic spectral features of surface reflectance associated with algal chlorophyll were analyzed. Results indicated that the NIR/red ratio was not an effective predictor of algal-chlorophyll concentration in our case, except on one occasion. The first derivative of reflectance, on the other hand, was better correlated with chlorophyll concentration than the 705/670 band ratio. The highest correlation between the first derivative and chlorophyll was at 690.7 nm.
Fraudulent Financial Reporting Detection: Key Ratios Plus Corporate Governance Factors

Prior research studies have examined the detection of fraudulent financial reporting using either financial ratios or nonfinancial factors relating to corporate governance. Are both types of factors relevant for such fraud detection? In this paper, we consider both types of factors, using experiences of fraudulent financial reporting companies as a learning opportunity for management, government regulators, investors, and auditors to develop early warning systems or red flags for fraudulent financial reporting.
Tracking kidney volume in mice with polycystic kidney disease by magnetic resonance imaging

Polycystic kidney disease is characterized by the progressive enlargement of kidneys due to expanding fluid-filled cysts with the rate of renal volume increase held to be a marker of disease progression. Magnetic resonance imaging (MRI) is used to monitor changes in renal volume in patients with polycystic kidney disease; however, it has not been effectively used in mice to monitor changes in kidney volume during drug treatment studies. We used a powerful 9.4-T horizontal bore magnetic resonance scanner to track changes in kidney volume in pcy/pcy mice, an ortholog of nephronophthisis type 3. Mice were sequentially scanned from 4 to 30 weeks of age and kidney volumes determined from high-resolution images. Kidney volume and maximal cross-sectional surface area correlated positively with kidney weight and the histologic determination of surface area. The increase in kidney volume was exponential up to 20 weeks of age, after which there was a plateau consistent with the replacement of normal parenchyma by fibrotic tissue. Our study demonstrates that MRI accurately determines the rate of kidney volume increase in mice with polycystic kidney disease and hence may be useful in assessing the effectiveness of therapeutic agents to slow disease progression.
New system for preparative electrochromatography of proteins.

Electrochromatography employs an axial electric field across a chromatographic stationary phase to separate proteins and other molecules based on differences in electrophoretic mobility. Because the separation is electrically driven, the need for additional chemical reagents is reduced. Two major impediments to scale-up of electrochromatography columns, removal of heat and electrolysis gases, have historically limited the diameter of packed columns to 2.5 cm ID with volumes of approximately 55 mL. We report a novel electrochromatography column that effectively removes electrolysis gases and minimizes heating. A vital component of this system is a new electrode design that couples a platinum gauze with an ultrafiltration membrane across both ends of the column. Use of a methacrylate base stationary phase enabled axial voltage gradients of 10 to 20 V/cm. Thermocouples inserted radially in the column at four axial positions showed that the flow of a 4°C mobile phase coupled with heat conduction through the column walls controlled the temperature to 28°C. The new column design, with dimensions of 3.81 cm ID × 38.1 cm long and bed volume of 400 mL, was demonstrated by separating mixtures of BSA and myoglobin. The column was operated in a horizontal position with radial sample injection and withdrawal at the ends of the packed bed. These experiments are a first step in demonstrating that scale-up of electrochromatography columns can be achieved by choosing appropriate flow rates, voltage gradients, and stationary phase. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 70: 72–81, 2000.
The Application of Silicon Detectors to Alpha Particle Spectroscopy

The sensitivity for detection of low abundance groups in an alpha spectrum was found to be limited primarily by a low energy tail in the pulse height distribution. The effects of scattering and source preparation on the magnitude of this tail were experimentally investigated. A theoretical lower limit of sensitivity for low abundance groups was calculated from consideration of scattering processes in the crystal. Background contamination in new detectors and the increase in background due to the collection of recoil nuclei was studied. Methods for minimizing the increase in background are suggested. A chamber, designed from a consideration of the above results, was constructed and used for the detection and measurement of low abundance groups in the alpha spectra of U234 and the actinium decay series.
Restoration of membrane excitability of calcium-deficient muscles by anodal polarization.

IT is well known that marked electrophysiological and biochemical disturbances occur in nerve and muscle immersed in calcium-free Ringer's solution1. In the present experiment, isolated frog (Rana pipiens) sartorius muscles were used. When they were soaked in calcium-free Ringer solution (112 mM sodium chloride ; 2 mM potassium chloride ; 2.4 mM sodium bicarbonate), initial hyper-excitability was followed by a loss of excitability. This effect of calcium deficiency was enhanced by adding ethylene-diaminetetraacetic acid to the medium. In calcium-free Ringer containing 4 mM ethylenediaminetetra-acetic acid, muscles twitch while the resting potential rapidly drops to 50–30 mV. within an hour. As usual, the electrical activity which ordinarily accompanies stimulation was completely but reversibly eliminated in the 60–120 min. following immersion. This loss of excitability cannot be explained simply by the reduction of the resting potential, since a number of fibres showed, transiently, a relatively high resting potential in spite of a loss of excitability2. Whether excitability was maintained depended on the susceptibility of individual fibres; even a seasonal variation being apparent. For example, the electrical activity of some muscles disappeared instantaneously in calcium-free Ringer, particularly in spring frogs. This seems to suggest that excitability depends on the properties of the membrane per se, which may be altered by the presence or absence of calcium ions.
Electronic Structure of Neighboring Extein Residue Modulates Intein C-Terminal Cleavage Activity

Protein splicing is an autocatalytic reaction where an intervening element (intein) is excised and the remaining two flanking sequences (exteins) are joined. The reaction requires specific conserved residues, and activity may be affected by both the intein and the extein sequence. Predicting how sequence will affect activity is a challenging task. Based on first-principles density functional theory and multiscale quantum mechanics/molecular mechanics, we report C-terminal cleavage reaction rates for five mutations at the first residue of the C-extein (+1), and describe molecular properties that may be used as predictors for future mutations. Independently, we report on experimental characterization of the same set of mutations at the +1 residue resulting in a wide range of C-terminal cleavage activities. With some exceptions, there is general agreement between computational rates and experimental cleavage, giving molecular insight into previous claims that the +1 extein residue affects intein catalysis. These data suggest utilization of attenuating +1 mutants for intein-mediated protein manipulations because they facilitate precursor accumulation in vivo for standard purification schemes. A more detailed analysis of the “+1 effect” will also help to predict sequence-defined effects on insertion points of the intein into proteins of interest.
The Long‐Term Effects of Parental Divorce in Childhood on Adult Adjustment

Relationships between experiencing a parental divorce or separation prior to age 16 and a variety of measures of adult adjustment and psychological functioning are examined using data from two national cross-sectional surveys conducted nearly 20 years apart. Although few differences between adults from parentally-divorced and intact family backgrounds persist when controls for contemporary life circumstances and other social background factors were included, two modest trends are still evident. First, although associations between psychological distress and early experience with parental divorce have weakened somewhat over the past two decades, coming from a non-intact family of origin still has some significance for adult psychological well-being. Second, men and women from non-intact families of origin display different patterns of adjustment to and valuation of the major life roles of spouse and parent. Nevertheless, because such relationships are not very powerful, it is concluded that contrary to much of the literature and popular thought, these early experiences have, at most, a modest effect on adult adjustment.
Comparison of the metabolism of [1,2,6,7-3H(N)]cholesteryl oleate, cholesteryl [9,10-3H]oleate, and cholesteryl [1-14C]oleate labeled lipoproteins in the rat

The intravascular metabolism of sterol labeled [1,2,6,7-3H(N)]cholesteryl oleate and acyl labeled cholesteryl [9,10-3H]oleate and cholesteryl [1-14C]oleate was compared in the rat, an animal species without plasma cholesteryl ester transfer activity (CETA). In a first series of studies, the metabolism of sterol labeled [1,2,6,7-3H(N)]cholesteryl oleate and acyl labeled cholesteryl [1-14C]oleate was compared, and the two tracers had identical plasma clearance rates when incorporated into human low density lipoproteins (LDL). The 3H sterol labeled cholesteryl ester (CE), however, had a plasma clearance rate lower than the 14C acyl labeled CE when incorporated into rat alpha- and beta-migrating LDL and human or rat high density lipoproteins (HDL). Unesterified 3H cholesterol reappeared in the plasma whereas the 14C radioactivity in the plasma remained associated with the CE. In a second set of studies, LDL and HDL were radiolabeled with cholesteryl [9,10-3H]oleate and cholesteryl [1-14C]oleate. Large amounts of 3H radioactivity that were dialyzable and not associated with the lipoprotein CE reappeared in the plasma during the kinetic studies. The two tracers had identical plasma disappearance rates when the plasma samples were dialyzed. The results of these studies indicate that the nature of the tracer used to trace lipoprotein CE can affect the estimated kinetic parameters of plasma CE.