cssi/SciSciGPT-SciSciNet huggingface dataset:
Stability of a model β-sheet in water

Abstract We have used molecular dynamics simulations to determine the stability in water of a model β-sheet formed by two alanine dipeptide molecules with two intermolecular hydrogen bonds in the closely spaced antiparallel arrangement. In this paper we describe our computations of the binding free energy of the model sheet and a portion of the free energy surface as a function of a reaction co-ordinate for sheet formation. We used the free energy surface to identify stable conformations along the reaction co-ordinate. To determine whether or not the model sheet with two hydrogen bonds is more stable than a single amide hydrogen bond in water, we compared the results of the present calculations to results from our earlier study of linear hydrogen bond formation between two formamide molecules (the formamide “dimer”). The free energy surfaces for the sheet and formamide dimer each have two minima corresponding to locally stable hydrogen-bonded and solvent-separated configurations. The binding free energies of the model sheet and the formamide dimer are − 5.5 and − 0.34 kcal/mol, respectively. Thus, the model sheet with two hydrogen bonds is quite stable while the simple amide hydrogen bond is only marginally stable. To understand the relative stabilities of the model sheet and formamide dimer in terms of solute-solute and solute-water interactions, we decomposed the free energy differences between hydrogen-bonded and solvent-separated conformations into energetic and entropic contributions. The changes in the peptide-peptide energy and the entropy are roughly twice as large for the sheet as they are for the formamide dimer. The magnitude of the peptide-water energy difference for the sheet is less than twice (by about 3.5 kcal/mol) that for the formamide dimer, and this accounts for the stability of the sheet. The presence of the side-chains and/or blocking groups apparently prevents the amide groups in the sheet from being solvated as favorably in the separated arrangement as in the formamide dimer, where the amide groups are completely exposed to the solvent.
Cutaneous sarcoidosis in a patient with philadelphia-positive chronic myelogenous leukemia treated with interferon-α

A patient with Philadelphia-positive (Ph+) chronic myelogenous leukemia (CML) was diagnosed with cutaneous sarcoidosis after treatment with interferon-alpha (IFN-alpha). Following IFN-alpha dose reduction, the skin lesions disappeared. Few cases of sarcoidosis associated with IFN treatment have been reported, and only in one patient with pre-existing CML. Our patient was unique in that (1) the sarcoidosis was induced by the IFN-alpha treatment alone, (2) it developed de novo, and (3) it was confined to the skin.
Pure Mutant Clones Induced by Ultra-Violet Light in the Green Alga, Chlamydomonas Reinhardi

Cells of C. reinhardi were irradiated with uv light, plated immediately after irradiation, and the colonies on a portion of the plates broken up (spread) to determine whether mixed mutations were induced. The mutational system used was one using forward mutations to acetate dependence. The number of mutants recovered in the spread and unspread series was about the same, indicating that the majority of uv-induced mutations to acetate dependence in C. reinhardi arise only in pure clones and that uv light induces mutations by a mechanism directly affecting the parental DNA. (D.L.C.)
Human taxonomic diversity in the pleistocene: Does Homo erectus represent multiple hominid species?

Recently, nomina such as “Homo heidelbergensis” and “H. ergaster” have been resurrected to refer to fossil hominids that are perceived to be specifically distinct from Homo sapiens and Homo erectus. This results in a later human fossil record that is nearly as speciose as that documenting the earlier history of the family Hominidae. However, it is agreed that there remains only one extant hominid species: H. sapiens. Has human taxonomic diversity been significantly pruned over the last few hundred millennia, or have the number of taxa been seriously overestimated? To answer this question, the following null hypothesis is tested: polytypism was established relatively early and the species H. erectus can accommodate all spatio-temporal variation from ca. 1.7 to 0.5 Ma. A disproof of this hypothesis would suggest that modern human polytypism is a very recent phenomenon and that speciation throughout the course of human evolution was the norm and not the exception. Cranial variation in a taxonomically mixed sample of fossil hominids, and in a modern human sample, is analyzed with regard to the variation present in the fossils attributed to H. erectus. The data are examined using both univariate (coefficient of variation) and multivariate (determinant) analyses. Employing randomization methodology to offset the small size and non-normal distribution of the fossil samples, the CV and determinant results reveal a pattern and degree of variation in H. erectus that most closely approximates that of the single species H. sapiens. It is therefore concluded that the null hypothesis cannot be rejected. © 1993 Wiley-Liss, Inc.
Specific lethality of silica for human peripheral blood mononuclear phagocytes, in vitro

Human peripheral blood mononuclear cells, cultured in the presence of 100 microgram/ml protein-coated silica particles, were studied to determine changes in number and function of monocytes, immunoglobulin bearing (B), sheep red blood cell rosetting (T) lymphocytes and the effector cells of antibody dependent cell-mediated cytotoxicity (ADCC). After 24-48 h, phagocytic cells were effectively eliminated from culture but there was no significant reduction in number or function of T or B lymphocytes or in ADCC to cell line targets. ADCC to erythrocyte targets was inhibited but not completely blocked. It is concluded that silica is a specific toxin for human peripheral blood mononuclear phagocytes and may be useful in in vitro immunological studies as a means of eliminating or determining the role of these cells without resort to separation methods which result in losses of cells other than monocytes.
Determination of Umbilical Catheter Placement Using Anatomic Landmarks

Background: The placement of umbilical catheters is an essential part of initial newborn resuscitation and stabilization in the delivery room and later in the neonatal intensive car
Newly designed self-retaining contact lens for vitreous surgery.

Abstract Purpose Development of a new self-retaining acrylic contact lens for vitreous surgery. Design A standard −60 diopters plano concave lens with the radius of curvature 6.7 mm (less than the cornea curvature) was modified with addition of four foot plates to facilitate stability and centration. Method A drop of viscoelastic material placed between lens and cornea induces negative suction and helps retain the lens in position. Conclusion This specially designed lens eliminates the need for suturing on the sclera or dependence on the assistant to provide placement. It provides a stable well-centered view of the fundus during vitreous surgery.
THE RELATIVE EFFECTIVENESS OF ANDROSTENEDIONE, TESTOSTERONE, AND ESTRONE, PRECURSORS TO ESTRADIOL, IN SEX REVERSAL IN THE RED-EARED SLIDER (TRACHEMYS SCRIPTA), A TURTLE WITH TEMPERATURE-DEPENDENT SEX DETERMINATION

Abstract In many turtles the temperature during the middle of incubation determines the gonadal sex of the hatchling. Sex steroid hormones have been implicated in temperature-dependent sex determination in the red-eared slider turtle, Trachemys scripta ; androgen is involved in male sex determination and estradiol in female sex determination. Administration of exogenous estradiol and its agonists to eggs incubating at a male-producing temperature can overcome the effect of temperature and result in all-female offspring. Exogenous testosterone will also result in some female hatchlings if administered to eggs incubated at a male-producing temperature, an effect due to the aromatization of testosterone to estradiol. This study demonstrates that in the red-eared slider, androstenedione, the precursor to both testosterone and estradiol, has a similar effect. In addition, both testosterone and androstenedione synergize with incubation temperature to exert a greater effect at intermediate incubation temperatures that normally produce mixed sex ratios, indicating that as with estradiol, androstenedione and testosterone are involved in the final common pathway of sex determination in this species. At the single dosage administered, estrone and estradiol produced all females at a male-producing incubation temperature.
Application of Computational Kinetic Mechanism Generation to Model the Autocatalytic Pyrolysis of Methane

An automated computational mechanism-generation technique is applied to construct elementary-step chemical kinetic reaction models for the pyrolysis of methane at 1038 K and 0.58 atm. Under these conditions, the pyrolysis process is extremely complex and exhibits autocatalysis. The mechanism-generation approach constructs a detailed set of elementary reactions, retrieves or estimates required reaction rates and thermochemistry, and constructs a kinetic model that gives excellent agreement with experimental data for several species. Key to the success is a newly developed capability of the algorithm to identify pressure-dependent chemically activated reactions. A rate-based species-selection methodology is used to determine kinetically significant species, and the algorithm is demonstrated to identify critical low-concentration byproducts. Multistep chemically activated reactions involving the formation of cyclopentadiene and subsequent hydrogen atom production are found to be important reactions, agreeing...
Beam-column design in steel frameworks— insights on current methods and trends

Abstract The first part of the paper describes the background behind the development of the current AISC-LRFD beam-column interaction equations. This is followed by a rigorous evaluation of the LRFD procedures with a specific focus on the use of effective length factors for beam-column design. Various methods of computing effective length factors are reviewed, and characteristic values obtained from the different methods are demonstrated. Comparisons are made between ultimate strength curves represented by the LRFD beam-column equations and strength curves computed by second-order inelastic analysis. Lastly, the procedure in the current Canadian Standard CSA-S16.1-M89, which does not involve the use of effective length factors, is posed in LRFD format and compared to the current LRFD method, which requires the use of K factors. The goal is to illustrate the qualities and limitations of both types of design approaches.
Titrimetric determination of some organic acids by xenon trioxide oxidation.

Aqueous xenon trioxide in acidic or neutral solutions oxidises carboxylic acids quantitatively to carbon dioxide and water. Micro and semimicro amounts of carboxylic acids may be determined by the iodometric titration of the excess of xenon trioxide remaining in the reaction mixture. The optimum time and temperature for the reaction depend on the structure of the acid ; dicarboxylic and hydroxy-carboxylic acids react faster than corresponding monocarboxylic acids. Oxalic and polyhydroxy acids are oxidised within 20 min at room temperature while acetic, maleic, succinic, malonic acids require 2 hr at 40 degrees . Carboxylic acids in amounts less than 100 mug are determined with a coefficient of variation of 4%, which decreases to 1 % for amounts over 250 mug.
Space applications of superconductivity - Instrumentation for gravitational and related studies

Superconducting instruments for gravitational studies and their state of development are discussed. Consideration is given to accelerometers, gravimeters, superconducting gyroscopes, and inertial guidance and navigation systems. This is followed by discussion of applications to tests of gravitational theories, determination of elastic properties of planets, and navigation.
Examining the Effects of Planning and Empathic Accuracy on Communication in Relational and Nonrelational Conflict Interactions

Grounded in message production research, we considered the effects of planning (plan vs. not plan), discussion type (relational vs. nonrelational), and perceived empathic accuracy on the likelihood of conflict resolution in close relationships. Eighty-two “dating” couples from a southeastern university participated in two conflict discussions; one concerned a relational problem, while the other focused on a nonrelational problem-solving task. As predicted, individuals were more likely to report the nonrelational task as resolved, compared to the relational discussion. While discussion type was not associated with empathic accuracy, there was a positive association between perceived empathic accuracy and conflict resolution. Surprisingly, planning was not associated with perceived conflict resolution. Implications for message production and interpersonal conflict research are discussed.
The metal-insulator transition in VO2☆

Abstract A model of the phase transition in VO2 is presented which is based on phonon softening effects and gives quantitative agreement with experiment.
Mechanical and electromechanical behavior of oxide coatings grown on stainless steel 304L by nanosecond pulsed laser irradiation

Abstract Nanosecond-pulsed laser exposure of an austenitic stainless steel 304L in ambient atmosphere produces dielectric oxide coatings with characteristic colors. From an industrial perspective, these oxide layers are particularly interesting for use as unique authenticity identifiers on welded or sealed components. Processing parameters control oxide thickness and residual stresses. The combined properties of the oxide–substrate system control deformation, fracture, and electromechanical behavior. Instrumented nanoindentation indicates that oxide mechanical properties are dictated by film thickness. While elastic modulus is relatively insensitive to laser processing conditions and has an average value of ~ 150 GPa, hardness decreases sharply as film thickness decreases below 100 nm. Indentation coupled with electron microscopy as well as conducting nanoindentation suggest that both fracture behavior and electromechanical response are a function of laser processing; thick oxides fracture circumferentially upon indentation while thin oxides undergo radial cracking and thinner laser oxides are typically more conductive than their thicker counterparts.
The determinants of the oligomeric structure in Hsp16.5 are encoded in the α-crystallin domain

The determinants of the oligomeric assembly of Hsp16.5, a small heat-shock protein (sHSP) from Methanococcus jannaschii, were explored via site-directed truncation and site-directed spin labeling. For this purpose, subunit contacts around the two-, three- and four-fold symmetry axes were fingerprinted using patterns of proximities between nitroxide spin labels introduced at selected sites. The lack of change in this fingerprint in an N-terminal truncation of the protein demonstrates that the interactions are encoded in the α-crystallin domain. In contrast, the truncation of the N-terminal domain of Mycobacterium tuberculosis Hsp16.3, a bacterial sHSP with an equally short N-terminal region, results in the dissociation of the oligomer to a trimer. These results, in conjunction with those from previous truncation studies in mammalian sHSP, suggest that as the α-crystallin domain evolved to encode a smaller basic unit than the overall oligomer, the control of the assembly and dynamics of the oligomeric structure became encoded in the N-terminal domain.
Effect of high-temperature exposure on the structure of inertia-friction welds in RS/PM Al-8. 5Fe-1. 3V-1. 7Si

Abstract Isothermal elevated-temperature exposure of the inertia-friction welded AA-8009 showed negligible dispersoid coarsening in the base metal and weld HDZ and an absence of dispersoid transformation at 425°C for exposure times up to 500 h. Hardness of the base metal was unaffected by thermal exposure at this temperature. Although hardness of the central HDZ decreased slightly with increased exposure time, it remained higher than that of the base metal. Exposure at 500 and 575°C promoted dispersoid coarsening and the formation of acicular Al 13 (Fe,V) 4 intermetallic particles, primarily along RS particulate boundaries in the base metal and weld outer HDZ. The random distribution of these intermetallic particles in the central HDZ resulted from the redistribution during welding of the coarse base metal dispersoids from which these particles transform. Thermal exposure to 575°C also resulted in a significant decrease in base metal and weld zone hardness.
Watch out for the climate change deniers

In the media and the courts, the crusade to undermine climate science and its researchers doesn't miss a trick, warns climatologist Michael Mann
The development of children's knowledge of alcohol and the role of drinking

Eighty children in kindergarten and grades 3, 6, and 8 were interviewed regarding their understanding of adult drinking and their knowledge of the rules of drinking. Understanding of adult drinking motives was assessed by asking them to interpret drinking episodes portrayed in brief vignettes. Their knowledge of drinking rules was inferred from answers to questions on where people drink, who can drink, how much is a lot to drink, and who decides the age of legal drinking. Children were also given a series of questions to assess their knowledge of physical causality. In addition, their parents were interviewed to determine their drinking frequency (in view of the children) and their attempts to talk with their children about drinking. The results indicated that children's understanding of adults' drinking motives followed closely a developmental model. Their motive scores were correlated with physical causality scores and, in the third grade, with their parents' drinking frequency. Girls' motive scores were significantly and consistently more mature than boys' scores. Furthermore, there was a significant relationship between children's stated intentions to drink and their parents' drinking frequency. The results are discussed in terms of the complexity of the concept of drinking; different dimensions have different developmental functions. Some aspects of drinking knowledge conform to other cognitive developmental phenomena (e.g., physical causality) while others are related to specific social context (e.g., parental drinking).
A numerical simulation of auroral ionospheric electrodynamics

A computer simulation of auroral ionospheric electrodynamics in the altitude range 80 to 250 km has been developed. The routine will either simulate typical electron precipitation profiles or accept observed data. Using a model background ionosphere, ion production rates are calculated from which equilibrium electron densities and the Hall and Pedersen conductivities may be determined. With the specification of suitable boundary conditions, the entire three-dimensional current system and electric field may be calculated within the simulation region. The results of the application of the routine to a typical inverted-V precipitation profile are demonstrated. The routine is used to explore the observed anticorrelation between electric field magnitude and peak energy in the precipitating electron spectrum of an auroral arc.
Analysis of age-associated changes in collagen crosslinking in the skin and lung in monkeys and rats

Abstract The present study was designed to address a specific question: can we define collagen aging in vivo in terms of alterations in collagen crosslinking? In order to assess the complete spectrum of change throughout life, tissues from rats, monkeys and (where available) humans were examined at ages ranging from fetal to old. Skin and lung were selected in order to include all of the crosslinks derived from lysyl oxidase-generated aldehydes that have been identified thus far, both reducible and norreducible. Crosslinks analyzed included hydroxylysinonorleucine, dihydroxylysinonorleucine, histidinohydroxymerodesmosine, hydroxypyridinium, lysyl pyridinium, and a deoxy analogue of hydroxypyridium found in skin that differs structurally from lysyl pyridinium. Tissues from both a short-lived species (rats) and a long-lived species (monkeys) were analyzed to test further the hypothesis that changes in crosslinking are linked predominantly to biological age of the animal, rather than temporal aging. We found that biological aging seems to regulate certain predictable changes during the first part of the lifespan: the disappearance postnatally of dihydroxylysinonorleucine in skin, the rapid decrease in difunctional crosslink content in lung and skin during early growth and development, and the gradual rise in hydroxypyridinium and lysyl pyridinium in lung tissue. Changes in crosslinking were far less predictable during the second half of the lifespan. Although hydroxypyridinium content continued to rise or reached a plateau in rat and monkey lungs, respectively, it showed a decrease in human lungs. The analogous trifunctional crosslink in skin, the so-called ‘pyridinoline analogue’, decreased dramatically in both rats and monkeys in later life. Our data suggest that caution must be taken in drawing inferences about human connective tissue aging from experiments performed in short-lived species such as rodents. Furthermore, the finding that there may be fewer total lysyl oxidase-derived crosslinks per collagen molecule in very old animals as compared with young animals suggests that we may need to expand our concepts of collagen crosslinking.
Intrinsic and Rashba spin-orbit interactions in graphene sheets

Starting from a microscopic tight-binding model and using second-order perturbation theory, we derive explicit expressions for the intrinsic and Rashba spin-orbit interaction induced gaps in the Dirac-like low-energy band structure of an isolated graphene sheet. The Rashba interaction parameter is first order in the atomic carbon spin-orbit coupling strength $\ensuremath{\xi}$ and first order in the external electric field $E$ perpendicular to the graphene plane, whereas the intrinsic spin-orbit interaction which survives at $E=0$ is second order in $\ensuremath{\xi}$. The spin-orbit terms in the low-energy effective Hamiltonian have the form proposed recently by Kane and Mele. Ab initio electronic structure calculations were performed as a partial check on the validity of the tight-binding model.
Adeno-associated viruses containing bFGF or BDNF are neuroprotective against excitotoxicity.

Purpose. Brain-derived neurotrophic factor (BDNF) and basic fibroblast growth factor (bFGF) hold much promise for the protection of retinal ganglion cells against excitotoxic cell death. We tested the possibility of delivering these growth factors to retinal ganglion cells via an adeno-associated viral (AAV) vector and tested their efficacy in two models of excitotoxicity.Methods. Rat retinas were infected with AAV vectors encoding bFGF or BDNF. A control vector containing green fluorescent protein (GFP) was injected in the contralateral eye. Eyes were subjected to either an intravitreal injection of N-methyl-D-aspartate (NMDA) or optic nerve crush, and ganglion cell survival was evaluated.Results. AAV.CMV.bFGF and AAV.CBA.BDNF were neuroprotective against NMDA injection 1 month post-treatment. Additionally, AAV.CMV.bFGF was protective against optic nerve crush.Conclusion. AAV-mediated delivery of bFGF and BDNF can promote retinal cell survival following excitotoxic insult.
Modifying Achievement Test Items: A Theory-Guided and Data-Based Approach for Better Measurement of What Students With Disabilities Know

Federal regulations allow up to 2% of the student population of a state to achieve proficiency for adequate yearly progress by taking an alternate assessment based on modified academic achievement standards (AA-MAS). Such tests are likely to be easier, but as long as a test is considered a valid measure of grade level content, it is allowable as an AA-MAS (U.S. Department of Education, 2007b). In this article, we examine procedures for developing, modifying, and evaluating items and tests using an evolving modification paradigm, as well as a classic reliability and validity framework. Theoretical influences, such as principles of universal design, cognitive load theory, and item development research, are discussed. The Test Accessibility and Modification Inventory, a tool that provides systematic and comprehensive guidance to help educators modify grade-level tests, is introduced. Cognitive lab methods and experimental field tests are then described, along with examples and key findings from each, relevan...
Crystal graphs, Tokuyama's theorem, and the Gindikin---Karpelevič formula for G 2

We conjecture a deformation of the Weyl character formula for type $$G_{2}$$G2 in the spirit of Tokuyama's formula for type $$A$$A. Using our conjecture, we prove a combinatorial version of the Gindikin---Karpelevia? formula for $$G_{2}$$G2, in the spirit of Bump---Nakasuji's formula for type $$A$$A.
The Crisis in Area Programs: A Time for Innovation

This paper had its genesis in the soul-searching of the now-famous Montreal ASA annual meeting of 1969 and in constructive discussions at the Boston annual meeting of 1970. At the latter meeting, I chaired a panel discussion (under the rubric of “New Directions in Area Programs”) in which a troublesome topic was ably probed by Olu Fadahunsi of Nigeria, John Povey, and Rodger Yeager. Their insights, together with those of others, are here brought to bear on the very real crisis which confronts so-called area studies programs in general and so-called African studies programs in particular. As Gray Cowan (1970, pp. 346-347) has noted, “We are entering upon a decade, or perhaps longer, in which it has become clear that the resources and opportunities for area study in the United States will be undergoing substantial reduction from those of the previous decade.” He joins others in warning that both the Federal government and the foundations are curtailing their support levels and that other impediments are rising including the growing reluctance of African host governments to allow freewheeling research by expatriates. Far from being unsubstantiated cries of alarm, such warnings are prompted by trends which are all too real. Moreover, the trends may best be regarded as symptomatic of a much deeper crisis--a crisis of concepts much more than merely of such limitations as funding or access to the field.
Hyperkalemia in the elderly: drugs exacerbate impaired potassium homeostasis.

Objective To review the pathophysiology underlying the predisposition to hyperkalemia in the elderly; the medications that disrupt potassium balance and promote the development of hyperkalemia in the elderly; the prevention of hyperkalemia in elderly patients treated with potassium-altering medications; and the appropriate management of hyperkalemia when it develops.
Is the transglenoid suture technique recommendable for recurrent shoulder dislocation? A minimum 5-year follow-up in 59 non-athletic shoulders.

The aim of this retrospective study is to compare the clinical outcomes following arthroscopic Bankart repair employing the transglenoid technique versus suture anchors in non-athletic shoulders of patients 30 years or older at the time of surgery. Fifty-nine consecutive patients who were available for a minimum of 5 years follow-up after arthroscopic Bankart repair were included. The transglenoid technique was employed in 27 patients whose age and follow-up period were 37 years (range 30–58) and 82 (range 61–109) months. Suture anchor was used in 32 patients whose age and follow-up period were 38 years (range 30–62) and 72 months (range 65–89). The Rowe scores of the transglenoid and suture anchor groups were 90 (range 35–100) and 90 (range 35–100), respectively, and there was no statistically significant difference between the two groups (p > 0.05). The Constant score of both groups was 92 (range 64–100) and 95 (range 62–100) without a significant difference (p > 0.05). Moreover, there were no significant differences between the recurrence rates (7%-transglenoid, 6%-suture anchor) (p > 0.05) and positive apprehension signs (7%-transglenoid, 3%-suture anchor) (p > 0.05). In non-athletes over 30-years-old, the results of the transglenoid technique in arthroscopic Bankart repair were comparable to those of the suture anchor. We suggest that the transglenoid technique is a viable alternative for older, non-athletic shoulder if the suture anchors are not available.
Optimal complexity of deployable compressive structures

The usual use of fractals involves self-similar geometrical objects to fill a space, where the self-similar iterations may continue ad infinitum. This is the first paper to propose the use of self-similar mechanical objects that fill an alloted space, while achieving an invariance property as the self-similar iterations continue (e.g. invariant strength). Moreover, for compressive loads, this paper shows how to achieve minimal mass and invariant strength from self-similar structures. The topology optimization procedure uses self-similar iteration until minimal mass is achieved, and this problem is completely solved, with global optimal solutions given in closed form. The optimal topology remains independent of the magnitude of the load. Mass is minimized subject to yield and/or buckling constraints. Formulas are also given to optimize the complexity of the structure, and the optimal complexity turns out to be finite. That is, a continuum is never the optimal structural for a compressive load under any constraints on the physical dimension (diameter). After each additional self-similar iteration, the number of bars and strings increase, but, for a certain choice of unit topology shown, the total mass of bars and strings decreases. For certain structures, the string mass monotonically increases with iteration, while the bar mass monotonically reduces, leading to minimal total mass in a finite number of iterations, and hence a finite optimal complexity for the structure. The number of iterations required to achieve minimal mass is given explicitly in closed form by a formula relating the chosen unit geometry and the material properties. It runs out that the optimal structures produced by our theory fall in the category of structures we call tensegrity. Hence our self-similar algorithms can generate tensegrity fractals.
Resistive MHD studies of high β tokamak plasmas

Abstract Numerical calculations have been performed to study the MHD activity in high-β tokamaks such as ISX-B. These initial value calculations build on earlier low β techniques, but the β effects create several new numerical issues. These issues are discussed and resolved. In addition to time-stepping modules, our system of computer codes includes equilibrium solvers (used to provide an initial condition) and output modules, such as a magnetic field line follower and an X-ray diagnostic code. The transition from current driven modes at low β to predominantly pressure driven modes at high β is described. The nonlinear studies yield X-ray emissivity plots which are compared with experiment.
Memory propagator matrix for long-time dissipative charge transfer dynamics

Iterative path integral methods provide a numerically exact approach to the dynamics of a quantum system coupled to a dissipative bath. These methods involve step-by-step propagation of a generalized multi-time reduced density matrix with a propagator that includes influence functional interactions that span the bath-induced memory length. Low-frequency baths lead to long memory that can span many time steps, necessitating the use of filtering procedures that select and store only statistically significant path segments, avoiding storage of the entire sparse propagator. The present paper further enhances the iterative path integral methodology through a deterministic procedure that identifies at the start of the calculation all memory-length path segments whose weights exceed a chosen threshold and builds the propagator matrix for use in all propagation steps. A binning procedure allows efficient pairing of path segments required in the construction of the propagator. Additional savings are achieved via a...
Honest or Deceitful? A Study of Persons' Mental Models for Judging Veracity

This study focused on understanding the detailed and dynamic mental models that people develop for judging veracity. It was hypothesized that individual differences in such mental models, assessed by using Thagard's (1989) ECHO computer simulation program, would predict participants' attributions and confidence in making attributions. After watching videotapes of targets, 120 participants rated targets' veracity and their own confidence in making attributions. Half of these participants also provided “on-line” information that, in turn, was entered into ECHO. The two groups did not differ in their judgments of veracity, but the on-line group was significantly more confident. Results from ECHO and network analysis indicated not only that participants' mental models for detecting deception are detailed, changing, and idiosyncratic, varying in their structure and degree of coherence, but also that a number of previously unidentified cognitive structures are used for detecting deception. Results that confirm the hypotheses are also presented.
On the well-posedness of discrete-time systems with slow and fast modes

Linear shift-invariant discrete-time systems satisfying the two time-scale property are considered. Conditions for a complete separation of slow and fast subsystems are given. The composite controller will be formed from the slow and fast subsystem controllers. The slow and fast subsystem trajectories will be obtained and they will be shown to approximate those of the original system. Conditions for existence of the solutions of the subsystem regulator problems will also be given
Dicarboxylic acid concentration trends and sampling artifacts

Abstract Dicarboxylic acids associated with airborne particulate matter were measured during a summer period in Philadelphia that included multiple air pollution episodes. Samples were collected for two 10 h periods each day using a high-volume sampler with two quartz fiber filters in series, and analyzed by gas chromatography mass spectrometry (GCMS) with diazomethane derivatization. Among the dicarboxylic acids investigated, phthalic acid and adipic acid exhibited the greatest diurnal variations and the strongest linear relationship with maximum daily ozone concentration. Dicarboxylic acids and ozone concentration exhibited a poor linear relationship with organic to elemental carbon ratio. All species investigated were affected by significant sampling artifact errors at low concentrations, but sampling errors were negligible at high concentrations observed during ozone episodes.
Measuring complexity using information fluctuation

Abstract A method for analyzing deterministic dynamical systems is presented. New measures of complexity are proposed, based on fluctuation in net information gain and its dependence on system size. These measures are applied to one-dimensional cellular automata and shown to be useful in selecting rules that support slow-moving gliders in quiescent backgrounds.
Designing Research-Based Instruction for Story Problems

Despite current research efforts in mathematics and science problem solving that emphasize situated and socially mediated approaches to solving authentic, complex problems, story problems remain the most common form of problem solving in K-12 schools and universities. Story problems typically present a quantitative solution problem embedded within a shallow story context. Most often, students use a procedural approach to their solution, directly translating story values into solvable algorithms. Research shows that this direct translation strategy results in a lack of conceptual understanding and the inability to transfer any problem-solving skills that are developed. Because traditional approaches to story problem-solving instruction do not support conceptual understanding of problem structures during their solution, more effective instructional approaches are needed for supporting story problems. This research review shows that solving story problems requires that learners construct a conceptual model of the problem that integrates the situational (story) content with an understanding of the semantic structure of the problem based on the principles of mathematics or science being practiced in the problem. The model also contains the processing operations required to solve the problem quantitatively. Constructing such a conceptual model enables learners to classify story problems before attempting any solution, a step essential to transfer. Based on research findings, I propose a model for 1 The reader may note that a substantial portion of the references in this article are dated. Most of the foundational research on story problems was conducted in the 1980s. The 1990s witnessed efforts to implement computer-based tools to support story problem learning. This article focuses on the processes for solving story problems and my own model for designing instruction to support those processes.
Emergency medical technician treatment of hypoglycemia without transport.

Objectives: We examine the safety and efficacy of emergency medical technicians (EMTs) providing treatment to stable hypoglycemic patients without transport or paramedic involvement, which is currently beyond their scope of practice. Methods: All hypoglycemic patients treated in the field without transport for 12 months were included. We used a patient follow-up survey to compare the outcomes of EMT and paramedic-treated patients on the occurrence of repeat hypoglycemic episodes, 911 calls, and/ or in-hospital reevaluation within 48 hours; patients' adhering to the provided instructions; and patient satisfaction. Results: Of 402 cases identified, we were able to contact and survey 203 (51%). There were no statistically significant differences for any of the outcome measures studied. Patients treated by EMTs (110) and paramedics (93) had 8 (7%) and 7 (8%) episodes of repeat hypoglycemia, 3 (3%) and 5 (5%) repeat 911 calls, and 9 (8%) and 10 (11%) hospital evaluations, respectively. Conclusions: Emergency medical technicians performed comparably with paramedics treating hypoglycemia without transport.
Quantitative image analysis of filament coupling and grain size in ITER Nb(Ti)/sub 3/Sn strand manufactured by the internal Sn process

Excellent images of Nb/sub 3/Sn filaments and their grain structure can be obtained from high resolution scanning electron microscopy of filamentary Nb/sub 3/Sn strands. Our aim has been to explore the detailed macro- and micro-structural characterization that can been achieved using image analysis of such micrographs. We have quantitatively characterized the filament size, shape and separation by digital image analysis. We have also used fracture surfaces to quantify both grain boundary density and morphology. Grain size and morphology varies not only from filament to filament but within the same filament too. We quantify here, for the first time, clear trends in the variation of both grain size and morphology, as well as local grain boundary density with respect to position within the filaments.
High-efficiency and side-viewing micro fiber optic probe for in-vivo diffuse reflectance measurements of human epithelial tissues

In this paper, we present a new micro fiber optic probe for in-vivo diffuse reflectance measurents of human epithelial tissues. The probe consists of seven, 120×120 μm collection fibers and one 200 μm incidence source fiber, arranged into a side-viewing configuration by using curved air-core waveguides with high optical transmittance. The outer dimension of the probe is 2×8mm2. The extremely small size, high transmission efficiency and side-viewing capability of the new probe make it suitable for endoscopic spectroscopic applications inside the human body.
Real-time automatic target location by template matching on blurred images

High precision manufacturing is dependent on the accurate positioning of the part prior to each processing step. The part is typically held in a transfer fixture which may be used either simply as a part holder or as an alignment reference. A typical application is explored in this work, grinding of slots in a thick ceramic wafer mounted on a part fixture. A 1 micron slot is located with a position tolerance of 10 microns in the nickel-zinc-ferrite wafer. Part location is determined by means of a 50.8 by 1 micron target deposited onto the ceramic during an earlier process. In the current process, the target is magnified by a 250X vision system and the machine operator manually aligns the part using a set of cross hairs overlaid on the image. A high precision x-y stage is used to adjust the part location. However, the use of a fixed focal distance camera combined with part mounting variation results in an unfocused image for the operator. Manual alignment of the unfocused image leads to target location error during centering of the target in the cross hairs. The misalignment, in turn, results in process variation. The location of the slots varies based on alignment and reduces the process capability. To reduce process variation, an automated target location algorithm has been applied. The algorithm uses template matching to detect the target. This simple algorithm has been shown to locate the target within the required tolerance in spite of image blur. Using low cost processing, the system is able to determine the target location in real-time. For real-time control, the algorithm must determine the x-y coordinate of the target in 10 seconds or less. This effort shows the potential for a simple location algorithm to be implemented in a manner which can significantly decrease process variation in a precision fabrication process.
Midterm patency rate after saphenous vein grafting with a PAS-Port device.

Recently, a new proximal anastomosis device of a saphenous vein graft (SVG) to the aorta, the PAS-Port device (Cardica, Redwood City, Calif) has been introduced and yielded encouraging results in terms of neurologic complications and early patency. However, there is a concern about the midterm (at least 1 year after surgical intervention) patency rate. The aim of this study was to evaluate the midterm patency rate of SVGs whose proximal anastomosis was performed with the PAS-Port device.
A SIMPLIFIED THEORY OF TENSE REPRESENTATIONS AND CONSTRAINTS ON THEIR COMPOSITION

This paper proposes a set of representations for tenses and a set of constraints on how they can be combined in adjunct clauses. The semantics we propose explains the possible meanings of tenses in a variety of sentential contexts. It also supports an elegant constraint on tense combination in adjunct clauses. These semantic representations provide insights into the interpretations of tenses, and the constraints provide a source of syntactic disambiguation that has not previously been demonstrated. We demonstrate an implemented disambiguator for a certain class of three-clause sentences based on our theory.
Tillage and Nitrogen Source and Rate Effects on Corn Response in Corn–Soybean Rotation

Conservation tillage systems present a challenge for integrating an efficient fertilizer program for corn (Zea mays L.) production in the U.S. Midwest and elsewhere. The objective of this study was to evaluate corn response to three tillage systems (no-tillage, strip-tillage, and chisel plow) and four N rates (0, 85, 170, and 250 kg N ha 21 )o f liquid swine manure and commercial fertilizer in a corn–soybean [Glycine max (L.) Merr.] rotation. A 3-yr study from 2002 to 2004 was conductedonaKenyonsoil(fine-loamy,mixed,mesicTypicHapludoll) at the Iowa State University Northeast Research and Demonstration Farm near Nashua, IA. The experimental design was a randomized complete block with split plots. Tillage and N rates were randomly assigned as main plot and subplot treatments, respectively. Corn grain yield and aboveground biomass response to different tillage systems were not significantly different for all N rates of both N sources; however, the biomass yield at different growth stages with different N sources, tillage, and N rates were inconsistent. There were no interaction effects of tillage and N rates on yields, except in a few cases. The 3-yr average of maximum (MNR) and economic optimal (EONR) N rates (182 and 174 kg N ha 21 , respectively) across all tillage systems with liquid manure produced identical maximum (MGY) and economic optimum (EOGY) grain yields of 11.7 Mg ha 21 . In contrast, the MNR and EONR (176 and 144 kg N ha 21 , respectively) with commercialfertilizerNproducedaMGYandanEOGYof11.2and11.1Mg ha 21 , respectively.
Alternating multiple tributaries + deltas

This work addresses the problem of trading off the latency in delivering the answer to the sink at the benefit of balancing the spatial dispersion of the energy consumption among the nodes and, consequently, prolonging the lifetime in sensor networks. Typically, in response to a query that pertains to the data from some geographic region, a tree structure is constructed and, when possible, some in-network aggregation is performed. On the other hand, in order to increase the robustness and/or balance the load, multipath routing is employed. Motivated by earlier work that combined trees and multipaths [19], in this paper we explore the possibility, and the impact, of combining multiple trees and multiple multipaths for routing, when processing a query with respect to a given region of interest. We present and evaluate two approaches that enable load-balancing in terms of alternating among a collection of routing structures.
The Management Ethics “Crisis”: An Organizational Perspective

The article focuses on business ethics in the United States and suggests there is an ethical lag in bureaucracy and business organizations. Scandals such as Watergate indicate that ethical standards have not been internalized from Judaic-Christian belief systems or civil religion. Managerial ethics should not be based on theistic individualism or ethical legalism. Executive codes of ethics should be based on three principles that foster ethical behavior throughout the organization, including the concept that cooperative social relations lead to moral action.
Memory and Forgetting in a Time of Violence: Brian Friel’s Meta-History Plays

In the 1980s, Brian Friel, one of Ireland's most successful twentieth century dramatists, authored two plays - Translations and Making History - which were concerned with major events in colonial history. Given the context in which the plays were written - Northern Ireland was in a state of war at the time - the playwright's choice of topics (the introduction of the National Schools and the Ordnance Survey in the nineteenth century and the failed Gaelic revolt against English rule and the Flight of the Earls in the sixteenth and seventeenth centuries) was both pointed and politically contentious. Yet, the argument of this essay is that rather than presenting versions of the past which conform to the ideological imperatives of a particular political stance, Friel's plays are much more interesting and significant in that they provoke a whole series of questions around the issue of historical representation. One of the most important of those questions is the applicability of the criteria truth and falsity in historical and other modes of interpretation. The essay concludes with a consideration of the politics of memory and forgetting in contemporary Northern Ireland.
What is measured by digital revenue meters

Digital revenue meters are now commonly used in power systems. Lately this technology is being applied in the residential sector. It is therefore important to know what impacts any new meter design has on the rate structures and billing charges, particularly when these new meters are applied to existing clients. This paper outlines the performance of some digital revenue meters based on different definitions when applied to non-linear loads.