cssi/SciSciGPT-SciSciNet huggingface dataset:
Fault analysis of the semi-insulated voltage transformer of distribution network caused by ferroresonance

This paper Initial on the solar parabolic trough collectors…Semi-insulated voltage transformers are widely used in power distribution network. The safety of their own equipment directly affects the safe and stable operation of power system. In this paper, the fault diagnosis and analysis process of a semi-insulated voltage transformer is described in detail. In this paper, the fault course and the condition of the fault equipment are introduced at first, and then the cause of the fault is clarified through the electrical test and disassembly analysis combined with the action protection condition. Finally, the preventive measures for the daily operation and maintenance of the equipment are put forward.
Time Domain Continuous-Time Model of Current Mode Buck Converter for Power Delivery Network Design

Proper power integrity (PI) analysis is essential for modem electronics devices to minimize voltage noise. The low- frequency response of a power distribution network (PDN) is determined by the voltage regulator modules (VRMs) installed on the board. However, the conventional VRM model is either represented by an over-simplified passive circuit or an encrypted model provided by then vendor. These models can only work for limited operating conditions. In this paper, a generic average model for up-to-date DC converter is proposed. Both time and frequency domain responses of a current-mode buck converter with adaptive on-time control (AOT) method are captured by the proposed model. This cycle-by-cycle averaged model can be extended for converters with other control methods.
Design Considerations of Three Phase Active Front End Converter for 13.8 kV Asynchronous Microgrid Power Conditioning System enabled by Series Connection of Gen-3 10 kV SiC MOSFETs

The recent growth in power generation using renewable energy sources has led to extensive research and development of robust and resilient power converters, which can integrate them with the medium voltage (MV) grids (13.8 kV,60Hz). Conventional power converters need a line frequency transformer for their integration to the MV grid, which increases the overall footprint and installation cost of the system. Therefore, a compact and lightweight alternative are required for largescale integration of the renewable energy source to the MV grid. With the advent of high voltage SiC MOSFETs, the operating frequency of grid converter can be increased up to 10-20 kHz, thus significantly reducing the size of filter inductors. The use of these devices in multi-level configurations with series-connected devices facilitates the design of power converters that can interface directly with MV grid, eliminating the need for line frequency transformers. The converter presented in this paper is designed to interface a 13.8 kV three-phase grid to a dc link of 24 kV. A three-level neutral point clamped (3L-NPC) topology enabled by series-connected 10 kV 15 A SiC MOSFETs and 10 kV 15 A SiC JBS diodes is presented. This paper focuses on the advantages, design considerations, and challenges associated with a medium voltage 3L-NPC converter. Experimental results show the successful operation of series-connected 10 kV 15 A SiC MOSFETs and JBS Diodes at medium voltage levels and highlights the series connection that is realized with snubber circuits for voltage balancing.
Secondary Bone Reconstruction

Secondary reconstruction of craniofacial skeletal defects represents a particularly challenging subset of maxillofacial surgery. Whether planned as part of multistage procedures or to address complications from primary reconstructive procedures that result in full-thickness bone defects or other suboptimal outcomes, secondary cases of maxillofacial reconstruction are typically more complicated than the initial reconstructive procedure. These surgeries are often associated with hostile wound environments that may be characterized by hypoxia, poorly compliant soft tissue envelopes (e.g., restrictive scar tissue burden), and, in certain cases, radiation injury. Not uncommonly, complex defects of the craniofacial skeleton require recruitment of soft tissue as well as bone to reestablish stable form and function.
Inhibitory deficits in rats rendered “mentally retarded” by early brain damage

Young rats with lesions to the parietal cortex, globus pallidus, or median raphe have previously been reported to be deficient in learning a wide variety of laboratory tasks. The purpose of the current study was to determine whether weanling rats with similarly placed lesions (or with hippocampal or amygdaloid lesions) would subsequently manifest a global deficit in behavioral inhibition (as evidenced by abnormalities on activity, extinction, spontaneous alternation, go/no-go discrimination, passive avoidance, spatial reversal, and visual reversal tests), and whether the degree of this inhibitory deficit would correlate with an independent assessment of learning ability (as gauged by performance on three distinct detour problems). The parietal and median raphe groups showed losses on at least six of the seven tests of inhibition, whereas the remaining groups showed losses on no more than three tests. However, the correlations between overall inhibition scores and learning scores did not exceed.43. Based on a key cluster analysis, two factors were extracted from the data on the inhibition tests. Inhibition related to Factor I (which was strongly associated with learning ability) appeared to underlie the suppression of an initially preferred response in the face of nonreinforcement or punishment. Inhibition related to Factor II appeared to underlie the suppression of an approach response to the negative cue in approach-avoidance and go/no-go discrimination situations. These results are discussed in relation to certain theories of intelligence and mental retardation.
Adolescent drinking and brain morphometry: A co-twin control analysis

Developmental changes in structure and functioning are thought to make the adolescent brain particularly sensitive to the negative effects of alcohol. Although alcohol use disorders are relatively rare in adolescence, the initiation of alcohol use, including problematic use, becomes increasingly prevalent during this period. The present study examined associations between normative drinking (alcohol initiation, binge drinking, intoxication) and brain morphometry in a sample of 96 adolescent monozygotic twins. A priori regions of interest included 11 subcortical and 20 cortical structures implicated in the existing empirical literature as associated with normative alcohol use in adolescence. In addition, co-twin control analyses were used to disentangle risk for alcohol use from consequences of alcohol exposure on the developing brain. Results indicated significant associations reflecting preexisting vulnerability toward problematic alcohol use, including reduced volume of the amygdala, increased volume of the cerebellum, and reduced cortical volume and thickness in several frontal and temporal regions, including the superior and middle frontal gyri, pars triangularis, and middle and inferior temporal gyri. Results also indicated some associations consistent with a neurotoxic effect of alcohol exposure, including reduced volume of the ventral diencephalon and the middle temporal gyrus.
A multimechanistic multicontinuum model for simulating shale gas reservoir with complex fractured system

Abstract Unconventional shale gas reservoirs have become the focus of considerable attention as primary energy resource over the past decades worldwide. Economic gas rate requires the creation of complex fracture networks which could be characterized by the stimulated reservoir volume (SRV) concept. Micro-seismic mapping technique could provide a measurement of the overall SRV and an estimate of the fracture patterns. Accurate and efficient numerical simulation of these reservoirs is challenging. There is substantial physical complexity involving a number of tightly coupled mechanisms in the modeling of gas production. The fabric of shale system with multicontinuum nature comprises organic material, inorganic matrix and natural fracture. The complexity is further amplified by the complex fracture networks with a wide range of fracture length scales and topologies. In this work, we develop a comprehensive physics-based, multicontinuum model to predict shale gas reservoir performance. The model is designed to incorporate the spectrum of known physics inherent in shale system, such as multiphase behavior, desorption, non-Darcy transport in ultra-tight porous media, high-velocity turbulent flow and rock un-consolidation within natural fractures. We also implement a novel hybrid fracture model (UDFM-MINC) that effectively integrates discrete fracture-matrix model (DFM) with continuum type of approach for simulating the multiscaled stimulated shale formations. Primary fractures are described using DFM with unstructured triangular grids (UDFM), and small-scale fractures are handled by the multiple interacting continua (MINC) model in a fully coupled manner. Optimized local grid refinement (LGR) technique is employed to accurately capture the transient flow regime around the primary fractures. We discuss the numerical implementation for the developed model, and present simulation results to demonstrate the model applicability. We also conduct preliminary sensitivity studies to determine the key factors of reservoir and fracture that affect the production performance of unconventional gas wells.
Influence of Direct Chill Casting Process Variables on Surface Quality of Aluminum Alloy Sheet Ingots

Surface defects formation and their effects on the surface quality of aluminum direct-chill cast sheet ingots have been investigated by metallographic examinations and mathematical modeling. The influence of process variables such as alloy composition, casting speed and lubricant on the surface defects especially extruded surface segregation layer has been determined. The metallographic study for collected samples of plant trials involved visual, micro-examinations and macrosegregation analysis. A 2-D mathematical model has been developed to characterize the thermal, solidification, interdendritic strain and macrosegregation distributions. Also, the model contained a new approach to evaluate qualitatively the macrosegregation formed during dendritic solidification. The model predications were compared to measurements from collected samples to verify the model, where a good agreement was obtained. The model predications illustrate that all the process variables tested have an observed effect on the surface quality by different levels. The mathematical analysis of strain fields as well as metallographic study has been used to explain and discuss the effects of different process variables on the surface quality.
The BPX radiation environment

Extensive neutronics analyses have been carried out to quantify and characterize the radiation environment of the Burning Plasma Experiment (BPX) device. The authors present the modeling approaches taken and the results obtained for the important radiation quantities. Attention is given to prompt neutron and gamma fluxes, lifetime insulation dose and helium production, nuclear heating distribution, and activation characteristics. It is noted that the BPX radiation environment has been analyzed with sufficient accuracy and depth to enable major project decisions to be made intelligently. It is found that the environment, though hostile, does not present insurmountable obstacles to the operation and maintenance of the facility, nor does it present unacceptable health or environmental hazards to the public. >
Global Warming and the Population Externality

Author(s): Stuart, Charles; Bohn, Henning | Abstract: We calculate the harm a birth imposes on others when greenhouse gas emissions are a problem and a cap limits emissions damage. This negative population externality, which equals the corrective Pigovian tax on having a child, is substantial in calibrations. In our base case, the Pigovian tax is 21 percent of a parent's lifetime income in steady state and 5 percent of lifetime income immediately after imposition of a cap, per child. The optimal population in steady state, which maximizes utility taking account of the externality, is about one quarter of the population households would choose voluntarily
Sugar level, fermentability, and acceptability of straw treated with different acids.

The sugar level, fermentability, and acceptability by voles of ryegrass straw treated with different acids were compared. Sugar release was highest with HCl, but acceptability was best with H3PO4 treatment. Candida utilis grew about equally well on all of the treated samples, except the one treated with 0.5 N HCl. That sample supported no growth, possibly because the level of chloride or degradation products of monomeric sugars was too high. Fermentability and palatability of straw were highest when treated with a combination of 0.23 N HCl and 0.15 N H3PO4. Fermentation with Aureobasidium pullulans further increased the palatability of the acid-treated straw.
Public Key Systems

This chapter contains sections titled: Introduction Merkle-Hellman Knapsack Diffie-Hellman Key Exchange Arithmetica Key Exchange RSA Rabin Cipher NTRU Cipher ElGamal Signature Scheme Summary Problems ]]>
The use of Saccharomyces cerevisiae proteomic libraries to identify RNA-modifying proteins.

Biochemical assay of proteomic libraries derived from the S. cerevisiae genome provides a powerful new tool for the assignment of activities to proteins. Particular advantages of this approach include the speed with which a protein can be identified, and the generality for any biological activity for which an assay can be developed. We discuss the utility of this approach for the identification of RNA modifying enzymes using a yeast proteomic library derived from a genomic set of strains expressing GST-ORF fusion proteins. This technique is also broadly applicable to other classes of RNA-protein interactions, including RNA binding and RNA degradation, and can be used with any of the proteomic libraries that are available.
Inflammatory Bowel Disease and Pancreatitis: A Review.

Background and aims: Pancreatic abnormalities are common in inflammatory bowel disease (IBD) patients and represent a heterogeneous group of conditions that include acute pancreatitis, chronic pancreatitis, autoimmune pancreatitis and asymptomatic abnormalities. We sought to review the available evidence concerning the aetiology, clinical presentation, diagnosis and treatment of pancreatic conditions in IBD patients. Methods: A PubMed/Medline query was conducted addressing pancreatic disorders in IBD. Reference lists from studies selected were manually searched to identify further relevant reports. Relevant manuscripts about pancreatic disorders in patients with IBD were selected and reviewed. Results: Thiopurines and gallstones are the most frequent causes of acute pancreatitis in IBD patients. Thiopurine-induced acute pancreatitis is usually uncomplicated and self-limited. Some evidence suggests that chronic pancreatitis may be more common in IBD. Most cases are idiopathic, affecting young males and patients with ulcerative colitis. Autoimmune pancreatitis is a relatively newly recognized disease and is increasingly diagnosed in IBD, particularly for type 2 autoimmune pancreatitis in ulcerative colitis patients. Asymptomatic exocrine insufficiency, pancreatic duct abnormalities and hyperamylasaemia have been identified in up to 18% of IBD patients, although their clinical significance and relationship with IBD remain undefined. Conclusions: The wide spectrum of pancreatic manifestations in IBD is growing and may represent a challenge to the clinician. A collaborative approach with a pancreas specialist may be the most productive route to determine aetiology, guide additional diagnostic workup, illuminate the aetiology and define the treatment and follow-up of these patients.
Description of the topological entanglement of DNA catenanes and knots by a powerful method involving strand passage and recombination.

Abstract We utilize a recently discovered, powerful method to classify the topological state of knots and catenanes. In this method, each such form is associated with a unique polynomial. These polynomials allow a rigorous determination of whether knotted or catenated DNA molecules that appear distinct actually are, and indicate the structure of related molecules. A tabulation is given of the polynomials for all possible stereoisomers of many of the knotted and catenated forms that are found in DNA. The polynomials for a substrate DNA molecule and the products obtained from it by either recombination or strand passage by a topoisomerase are related by a simple theorem. This theorem affords natural applications of the polynomial method to these processes. Examples are presented involving site-specific recombination by the transposon Tn3-encoded resolvase and the phage λ integrase, in which product structure is predicted as a function of crossover mechanism.
Cartalk! Conversational Topics of Preschool Children En Route Home from Preschool.

The conversations of 9 preschool-age children (chronological age [CA] 4:0 to 5:2, years:months) were tape-recorded as they traveled home from school with their parent in the family car. The speech ...
Effect of temperature on metabolism and hemolymph pH in the crab Stoliczia abbotti

1. 1.|Oxygen consumption, hemolymph pH and total CO2 were measured in the crab Stoliczia abbotti following short-term acclimation to temperatures between 10 and 35°C. 2. 2.|Crabs maintained at 25°C had an oxygen consumption of 797.7 μl O2·h−1. Q10s between 20 and 35°C varied between 1.22 and 2.4. The Q10 between 15 and 20°C showed a significant increase to 6.03. 3. 3.|Hemolymph pH decreased from 7.695 to 7.243 between 17 and 35°C (−0.025 ΔpH/Δ°C). Between 10 and 17°C hemolymph pH did not change significant (−0.004 ΔpH/Δ°C). Hemolymph CCO2 did not change significantly with temperature. 4. 4.|The correlation between the temperature (15–20°C) at which crabs no longer maintain a constant relative alkalinity and experience a greater than normal reduction in oxygen consumption is consistent with predictions of the constant charge state hypothesis.
IMPLANTED TUMOUR GROWTH IN MICE EXPOSED TO CONTINUOUS CENTRIFUGATION.

BECAUSE of the known effects of high gravity on normal growth, and of other associated effects which might influence a tumour-host relationship, 5-week-old, Swiss Webster mice bearing transplanted sarcoma 180 tumours were subjected to continuous centrifugation simulating high-intensity gravitational fields. Experiments with several living forms have demonstrated that a gravitational field influences growth mechanisms and their control1,2. Continuous exposure of mice to centrifugation can produce a retardation of normal growth. Initial exposure induces a decrement in food intake3 and in body mass followed by a gradual but usually incomplete recovery4. There are other effects such as changes in relative dimensions of the adrenal gland, spleen, and femur bone1,2,5. (It should be appreciated, however, that some of these changes might not be meaningful as relative organ sizes vary with stage of development6.) Both the spleen and the adrenal gland have been implicated in the tumour–host relationship7. Also a decreased caloric intake, characteristic of animals exposed to centrifugation, has been reported by many workers to retard the growth of transplanted tumours in experimental animals. This is reviewed by White8.
The mechanism of the cycloaddition reaction of 1,3-dipole molecules with acetylene: an investigation with the unified reaction valley approach

The unified reaction valley approach (URVA) is used in connection with a dual-level approach to describe the mechanism of ten different cycloadditions of 1,3- dipoles XYZ (diazonium betaines, nitrilium betaines, azomethines, and nitryl hydride) to acetylene utilizing density functional theory for the URVA calculations and CCSD(T)-F12/aug-cc-pVTZ for the determination of the reaction energetics. The URVA results reveal that the mechanism of the 1,3-dipolar cycloadditions is determined early in the van der Waals range where the mutual orientation of the reactants (resulting from the shape of the enveloping exchange repulsion spheres, electrostatic attraction, and dispersion forces) decides on charge transfer, charge polarization, the formation of radicaloid centers, and the asynchronicity of bond formation. All cycloadditions investigated are driven by charge transfer to the acetylene LUMO irrespective of the electrophilic/nucleophilic character of the 1,3-dipole. However, an insufficient charge transfer typical of an electrophilic 1,3- dipole leads to a higher barrier. Energy transfer and energy dissipation as a result of curvature and Coriolis couplings between vibrational modes lead to an unusual energy exchange between just those bending modes that facilitate the formation of radicaloid centers. The relative magnitude of the reaction barriers and reaction energies is rationalized by determining reactant properties, which are responsible for the mutual polarization of the reactants and the stability of the bonds to be broken or formed.
Photostationary state deviation–estimated peroxy radicals and their implications for HOx and ozone photochemistry at a remote northern Atlantic coastal site

[1] Measurements of NO, NO2, O3, and ultraviolet irradiance made at Cape Norman, Newfoundland (51.6°N, 55.9°W), during February–April 1996 were used to examine peroxy radical photochemistry and the local photochemical ozone tendency. Deviations from NO-NO2-O3 photostationary state (the PSSD method) were used to estimate peroxy radical (PO2) mixing ratios. Potential biases in the PSSD method and the methods used to apply it in an unbiased manner are discussed. PO2 levels reached 77 ± 8 pptv (midday mean ±2σ of the mean), significantly higher than observed in previous studies at remote marine locations. [PO2] was well correlated with ()1/2, indicating that the dominant radical source was photolysis by ultraviolet radiation in the wavelength region of O3 photolysis and the dominant sink of PO2 was recombination. However, the variation of [PO2] with ()1/2 (d[PO2]/d()1/2) was significantly higher than expected at this site during spring. Significant radical production in addition to that from net O3 photolysis, possibly related to snow photochemistry in the upwind region, is suggested as the cause. However, the measurements needed to test this hypothesis were not made in this study, and we suggest future HOx measurements in remote midlatitude, snow-covered regions. The net photochemical ozone production at this site during springtime was calculated to be minimal (generally small and negative, and always less than or equal to +0.1 ppbv/h). These small values indicate that in situ photochemical ozone production is negligible at this site during spring; if [HO2]/[PO2] is large, net ozone destruction may contribute up to ∼10% of mean ozone levels per day.
Parent Education as a Mandatory Component of Preschool: Effects on Middle-Class, Educationally Advantaged Parents and Children.

Data from 127 middle-class, educationally advantaged parents and their preschool children were used to explore the effects of participation in a mandatory parent education component of a university preschool program. Employing four conditions of parent education participation and preschool attendance, the study assessed parental attitude, parents' involvement in 20-min, one-on-one activities with their preschool child, and child outcome measures of IQ and social competency. Findings indicated that (a) the majority of the parents in the sample already possessed attitudes consistent with those espoused by the parent education program; (b) significantly more parents who had participated in parent education engaged in weekly 20-min, one-on-one activities with their preschool child; (c) participation in parent education was associated with an increase in the number of parent-child 20-min, one-on-one activities for fathers and a decrease for mothers; and (d) preschool, but not parent, education was linked to gains on child competency measures.
Circadian organization of an animal lacking a pineal organ; the young American alligator,Alligator mississippiensis

Circadian rhythms were examined in young American alligators,Alligator mississippiensis, an animal that naturally lacks a pineal organ. Individual alligators displayed persistent, stable, free-running circadian activity rhythms under both constant darkness and constant illumination. Free-running activity was entrained by 24 h light-dark cycles. The circadian period length was also temperature compensated, with Q10's of 1.0–1.40 obtained for a 22–32 °C interval. The presence of this quite ‘normal’ circadian rhythmicity in alligators indicates that the pineal organ is not always essential for the expression of circadian rhythms in lower vertebrates.
Stimulation of HCO3- excretion in frog skin by urinary and adrenal cortical extracts.

Abstract 1. 1. There is a substance extractable from human urine which stimulates frog skin to excrete bicarbonate. The response to this extract is delayed, taking 4–9 hr, depending upon the dosage. 2. 2. The amount of this substance varies with the bicarbonate intake of the urine donor. 3. 3. This is a reasonable dose-response curve to the extract. 4. 4. A substance with the same solubility characteristics, and which stimulates bicarbonate excretion with a similar time response is present in adrenal cortical extracts.
On the moduli spaces of multipolygonal linkages in the plane

Abstract One can form a polygonal linkage by identifying initial and terminal points of two free linkages. Likewise, one can form a multipolygonal linkage by identifying initial and terminal points of three free linkages. The geometric and topological properties of moduli spaces of multipolygonal linkages in the plane are studied. These spaces are compact algebraic varieties. Some conditions under which these spaces are smooth manifolds, cross products or disjoint unions of moduli spaces of polygonal linkages, or connected, are determined. Dimensions in smooth manifold cases and some Euler characteristics are computed. A classification of generic multiquadrilateral linkages is also made.
Themes and Issues in Chinese Business History

This chapter examines the major themes and issues in Western literature on Chinese business history since the late Ming period. As an area of academic inquiry, Chinese business history is relatively new, being a subfield of America's postwar China studies, and less developed, reflecting the peripheral role of the bourgeoisie in Chinese history. There are limitations in doing research on this field, partly because of scarcity of materials in the official history, and partly because it does not have a clearly focused scope for study. Indeed, there is no generally accepted definition of business history, even in the United States, where this discipline started and has thrived. The amorphous nature of this field is further indicated by the fact that it does not have a counterpart on the Chinese side.
Enhanced solar wind geoeffectiveness after a sudden increase in dynamic pressure during southward IMF orientation

[1] It is well known that a persistent southward Interplanetary Magnetic Field (IMF) produces increased geomagnetic activity. It has recently been shown that a sudden increase in solar wind pressure results in poleward expansion of the auroral oval and closing of the polar cap over a wide range of MLTs, and this effect is more pronounced under southward IMF orientation. We show that southward IMF conditions combined with high solar wind dynamic pressure immediately after a pressure front impact lead to enhanced coupling between the solar wind and the terrestrial magnetosphere, significantly increasing the geoeffectiveness of the solar wind. We evaluate geoeffectiveness by the coupling efficiency, defined as the ratio of the cross-polar-cap potential measured by Defense Meteorological Satellite Program (DMSP) spacecraft to the cross-magnetospheric potential calculated using solar wind parameters. We examine changes in the size of the polar cap and the coupling efficiency for a number of solar wind pressure enhancements under southward IMF configuration. We confirm the previously observed closing of the polar cap and show that there is a simultaneous increase of the coupling efficiency. This increase is measured for all cases, despite the fact that the magnetosphere is greatly compressed, and the increase is measured even when the solar wind electric field is reduced.
Intensity calibrated hydrogen flame spectrum

Abstract The detection of hydrogen fires is important to the aerospace community. The National Aeronautics and Space Administration (NASA) has devoted significant effort to the development, testing, and installation of hydrogen fire detectors based on ultraviolet, near-infrared, mid-infrared, and/or far-infrared flame emission bands. Yet, there is no intensity calibrated hydrogen-air flame spectrum over this range in the literature and consequently, it can be difficult to compare the merits of different radiation-based hydrogen fire detectors. In this paper we present an intensity calibrated irradiance spectrum for a low pressure hydrogen flame burning in air from 200 nm to 13.5 microns that varies by more than six orders of magnitude. The results resolve relative intensity errors between spectral bands that appear within the literature. The impact of the measured spectrum on the choice of radiation-based hydrogen fire detectors is discussed.
Prevention of secondary stroke and resolution of transfusional iron overload in children with sickle cell anemia using hydroxyurea and phlebotomy

Abstract Objective Transfusions prevent secondary stroke in children with sickle cell anemia (SCA) but also cause iron overload. Alternatives for stroke prophylaxis with effective therapy to reduce iron burden are needed. Study design For 35 children with SCA and stroke, transfusions were prospectively discontinued. Hydroxyurea was prescribed for stroke prophylaxis, and phlebotomy removed excess iron. Initial patients discontinued transfusions before hydroxyurea therapy, but later patients overlapped transfusions with hydroxyurea until tolerating full-dose therapy. Results Children received hydroxyurea for 42 ± 30 months (range, 3-104 months). Hydroxyurea (26.7 ± 4.8 mg/kg per day) led to mild neutropenia (3.9 ± 2.3 × 10 9 /L) with significant increases in hemoglobin concentration, mean corpuscular volume, and fetal hemoglobin. Stroke recurrence rate was 5.7 events per 100 patient-years, but children receiving overlapping hydroxyurea therapy had only 3.6 events per 100 patient-years. For 26 children with >6 months of phlebotomy, 14,311 ± 12,459 mL blood (315 ± 214 mL/kg) was removed, with serum ferritin decreasing from a median of 2722 to 298 ng/mL. Among patients completing phlebotomy, liver biopsy documented normal histology and no excess iron deposition. Conclusions For children with SCA and stroke, hydroxyurea effectively prevents secondary stroke and serial phlebotomy leads to complete resolution of transfusional iron overload.
Periodic lattices in Minkowski space

We describe a set of periodic lattices in (1+1)-dimensional Minkowski space, where each lattice has an associated symmetry group consisting of inhomogeneous Lorentz transformations that map the lattice onto itself. Our results show how ideas of crystal structure in Euclidean space generalize to Minkowski space and provide an example that illustrates basic concepts of spacetime symmetry.
Schrödinger operators with complex-valued potentials and no resonances

In dimension d≥3, we give examples of nontrivial, compactly supported, complex-valued potentials such that the associated Schrodinger operators have neither resonances nor eigenvalues. If d=2, we show that there are potentials with no resonances or eigenvalues away from the origin. These Schrodinger operators are isophasal and have the same scattering phase as the Laplacian on Rd. In odd dimensions d≥3, we study the fundamental solution of the wave equation perturbed by such a potential. If the space variables are held fixed, it is superexponentially decaying in time
Communication during intraorganizational innovation adoption: Predicting users' behavioral coping responses to innovations in organizations

Much empirical evidence suggests that explanations for innovation outcomes should be located in an understanding of users' responses to innovations (Ashford, 1988; Fulk, 1993; Lewis & Seibold, 1993; Miller, Johnson, & Grau, 1994; Poole & DeSanctis, 1990). Unfortunately, researchers have neglected to pursue systematic studies of behavioral responses to innovations in accounting for particular innovation outcomes. The investigation reported draws on previous research that isolated three dimensions of interaction‐based coping responses: favorableness, decidedness, and focus (self vs. other). The present study tests the relative effects of several antecedents to users' (N= 216) behavioral coping responses to quality programs in four organizations. Results of hierarchical regression analyses indicated that users' attitudes, concerns for performance, normative influence, and uncertainty, and their perceptions of the context of change affect each of the three dimensions of their behavioral coping responses.
Optical absorption microscopy and spectroscopy with nanometre resolution

SEVERAL variants of the scanning tunnelling microscope (STM) have been developed since its invention1. Here we present the first demonstration of a new type of microscope, based on the STM, that is capable of recording optical absorption spectra with nanometre (that is, molecular) resolution. Our starting point is conventional photothermal spectroscopy, in which the temperature rise owing to the absorption of tunable monochromatic light is measured, giving a direct measurement of the absorption spectrum of a sample as a function of illuminating wavelength. The spatial resolution of such measurements is determined by the sizes of the pump beam or detector, whichever is smaller. We use the STM to measure the 'thermoelectric' tunnelling voltage due to absorption. Conventional photothermal measurements2,3 have been limited to a resolution of ∼1 μm, although we have recently developed a thermal sensor with a spatial resolution of ∼50 nm (ref. 4), and suggested its use for spectroscopy on that scale5. The STM, however, permits resolution of about 1 nm, and as the image is controlled by the thermal properties of the sample, our technique can image variations in the thickness of surface films, and changes in sub-surface characteristics, as well as chemical variations.
DNA methylation of liver and HTC cells during corticosteroid induction.

Abstract The status of DNA methylation, as measured by m5C 2 content of nuclear DNA, was examined during corticosteroid mediated TAT induction in rat liver and in dividing and nondividing HTC cells. The m5C content, determined by HPLC, was not significantly altered in HTC cells during TAT induction whether the cells were in the logarithmic or stationary growth phase. In the liver of adrenalectomized rats where the range of corticosteroid effects is greater than in HTC cells, a small but significant decline in genomic levels of m5C was detected between 1 to 8 hr post-induction. The alterations in DNA methylation did not fluctuate during induction by more than 8% in the liver or 7.5% in HTC cells. These results demonstrate that no gross change or elevation in m5C content is detected in two, different, hormonally responsive hepatocellular systems during gene activation.
Comparative analysis of chromatography peaks by computer and disc-integrator.

Abstract A reliability study was conducted to compare a new, computerized method of measuring the areas under chromatographic curves with the traditional hand method of determining the areas. Three runs of 30 separate injections of standard inorganic phosphate were made using the chromatographic and dry-ashing procedure developed in the laboratory of the Department of Pharmacology of the USC School of Medicine. Results indicate that there is no statistically significant difference between the traditional method and the new computer method for amounts greater than 10 nm, and the computer method is more precise for amounts less than 10 nm. Hence, great savings in time and an increase in precision can be made by using a computer for these analyses.
Emergency related video streaming in VANET using network coding

Multimedia (e.g., video) information exchange in VANET, if feasible, will help enhance vehicle navigation safety. We show that network coding allows very reliable and efficient data dissemination and thus is suitable for multimedia safety information dissemination. If the vehicle column has gaps, network coding jointly with "data muling" on vehicles in the opposite direction can deliver the multimedia files to disconnected components faster than other known schemes.
Hydrocarbons in the water and sediment of wilderness lake II

Abstract Hydrocarbons are reported for another wilderness lake including polynuclear aromatics. All hydrocarbons appear to be of natural origin.
Rapid transitions among functional states support efficient osmoregulatory acclimation: focus on “Functional plasticity of mitochondrion-rich cells in the skin of euryhaline medaka larvae (Oryzias latipes) subjected to salinity changes”

there is a decades-long history of research to understand the biology of mitochondrion-rich cells (MRCs; ionocytes) in the gills, skin, and other integumentary tissues of fishes that bear direct contact with the external environment. Beginning in the 1930s, experiments to partition whole-animal salt
Knotted periodic orbits in suspensions of smale's horseshoe: Extended families and bifurcation sequences

Abstract We consider knotted periodic orbits in the “natural” suspension of Smale's horseshoe map as constructed by Holmes and Williams (1985) and Holmes (1986). We identify quartets and octets of periodic orbits which are isotopic knots and indicate how they are related via the sequences of bifurcations in which they are created in two-parameter families such as the Henon map.
The influence of protein aggregates on the fouling of microfiltration membranes during stirred cell filtration

Abstract Although macromolecular fouling of microfiltration membranes is one of the critical factors governing the performance of these filtration processes, there is still little fundamental understanding of the underlying phenomena that influence the initiation, rate, and extent of fouling. We have obtained experimental data for the flux decline during the stirred cell filtration of different commercial preparations of bovine serum albumin (BSA) through asymmetric polyethersulfone microfiltration membranes. The fouling characteristics of these commercial solutions varied substantially, with the flux decline directly related to the technique utilized to initially precipitate and prepare the BSA. Prefiltration of BSA solutions prior to microfiltration substantially reduced their fouling tendency, with the degree of improvement increasing as the prefiltration was performed through smaller molecular weight cut-off membranes. The protein solutions were also characterized using gel permeation chromatography (GPC), with the fouling tendency of the different BSA preparations highly correlated with the concentration of BSA dimers and other high molecular weight species present in these BSA solutions. These results suggest that BSA fouling of these microfiltration membranes is associated with the deposition of trace quantities of aggregated and/or denatured BSA, with these fouling species serving as initiation sites for the continued deposition of bulk protein.
Modifying Locus of Control Scores Through Mnemonic Training

Summary The purpose of this study was to determine if academic performance affects locus of control scores. Twenty-one college students were randomly assigned to either a treatment or control group by sex. The treatment group received mnemonic training enabling them to score better than the control group. The treatment group had significantly more internal scores than the control group with the Rotter Locus of Control Scale but not with the Nowicki-Strickland I-E Scale.
Relationship between suboptimal cognitive effort and the clinical scales of the Personality Assessment Inventory.

Little research has examined the relationship between the Personality Assessment Inventory (PAI) and cognitive effort. The current study extends the research on personality assessment and suboptimal cognitive effort by evaluating the relationship between the PAI clinical scales and the Test of Memory Malingering (TOMM) in a neuropsychological population. Utilizing corrections for multiple comparisons, rank-order correlations with the TOMM Trial 2 (T2) and the PAI clinical scales indicated a significant relationship with the SOM (rho = −.26, p <.001), with additional scales (SCZ, ANX, and DEP) trending toward significance. Analysis of SOM subscales indicated a significant relationship between SOM-C and T2 as well. To further explore the relationship between SOM and the TOMM, ANOVA results indicated that individuals scoring within normal limits on the SOM had higher mean TOMM scores than those with extremely elevated SOM. Additional analyses indicated that utilizing the cut-off for extreme responding on the...
Role of Electrostatics in Modulating Hydrophobic Interactions and Barriers to Hydrophobic Assembly

Hydrophobic effects continue to be an active area of research due to implications for a wide range of physicochemical phenomena. Molecular dynamics simulations have been used extensively in the study of such effects using various water potential models, with few studies addressing the differences between models. In particular, studies considering the explicit treatment of water polarizability are underrepresented in the literature. We present results from molecular dynamics simulations that systematically compare the dependence of large-scale hydrophobic effects on the water model. We consider three common nonpolarizable models (SPC/E, TIP3P, and TIP4P) and two common polarizable models (TIP4P-FQ and SWM4-NDP). Results highlight the similarities and differences of the different water models in the vicinity of two large hydrophobic plates. In particular, profiles of average density, density fluctuations, orientation, and hydrogen bonding show only minor differences among the water models studied. However, the potential of mean force for the hydrophobe dimerization is significantly reduced in the polarizable water systems. TIP4P-FQ shows the deepest minimum of approximately -54(+/-3) kcal/mol compared to -40(+/-3), -40(+/-2), -42(+/-3), and -45(+/-5) kcal/mol for TIP4P, TIP3P, SPC/E, and SWM4-NDP (all relative to the dissociated state). We discuss the relationship between hydrophobic association and the strength of water-water interactions in the liquid phase. Results suggest that models treating polarizability (both implicitly and explicitly) influence a stronger driving force toward hydrophobic assembly. Implications of these results, as well as prospectives on future work, are discussed.
Efficient Global Optimization with Adaptive Target Setting

S URROGATE-BASED optimization is becoming increasingly popular due to savings in computational time [1–12]. Surrogatebased optimization proceeds through cycles, selecting new sampling points that contribute toward global optimization in each cycle. Algorithms like the popular efficient global optimization (EGO) of Jones et al. [11,12] use both the surrogate prediction and its error estimates. The most common EGO variant uses prediction and prediction variance to seek the point of maximum expected improvement (EI) [12]. Jones [12] also discusses a version of EGO that uses the probability of improvement (PI) beyond a given target as the selection criterion. The use of PI was first introduced by Kushner in 1964 [13] for a one-dimensional algorithm. It was extended heuristically to higher dimensions by Stuckman [14], Elder [15], and Mockus [16]. Maximizing PI can balance local and global searches, but its performance can be sensitive to the target value [12]. If the target is too ambitious, the search is excessively global and slow to focus on promising areas. If the target is too modest, there is exhaustive search around the present best solution (PBS) before moving to global search. This issuemay account for the lack of popularity of EGOwith PI. Jones [12] proposed to address the issue of target setting by considering several target values to add multiple points per cycle, calling the method “a highly promising approach”. Queipo et al. [17] proposed away to estimate the optimum that could be used as a target. In this work, we propose an adaptive target method that adapts the target for each EGO cycle according to the success of meeting the target in the previous cycle. We dub this variant EGO-AT (for “adaptive target”). EGO-AT learns from the history of progress to predict what to expect in the next cycle. Traditionally, EGO-like algorithms add one point per cycle. When simulations take long to complete, it is attractive to run in parallel multiple simulations per cycle. Consequently, there has beenwork on including multiple points [18–21]. Selecting multiple points to maximize EI is computationally expensive [20]. However, there are methods such as kriging believer [20] and constant liar [20] to moderate the expense of multipoint EI. Using PI for finding multiple points using a single surrogate has been shown to be quite cheap [12,22]. The joint probability of all the points being added can also be easily calculated for a single target [22]. The major objective of this work is to bring PI on equal footing with EI and remove issues with using EGO-PI. In addition, EGO-AT provides two ingredients that may be useful for decisions on stopping: amount of improvement to target and the probability of targeted improvement [23,24].
Charge‐exchange in the nonadiabatic Na/W gas‐surface reaction using a diabatic representation

=A theoretical description of near-resonant charge exchange is presented for gas-surface collisions, based on the eikonal formalism, short wavelength approximation, and diabatic representation. The dynamics of the charge transfer is analyzed for the Na/W system. Accurate model diabatic potential surfaces are used to compute the charge exchange during scattering and desorption. The Pad6 method is applied to approximate the charge exchange probability. The derivations, developments, and comparisons of approximations of the charge-exchange probability are discussed. These approximations are useful in experimental surface analysis to estimate the integral value of diabatic coupling between the atomic and ionic states. The frequency of oscillation during the chargeexchange process is also discussed. Model diabatic potentials in analytic forms for the Na/W system are reported. 0 1995 John Wiley & Sons, Inc.