cssi/SciSciGPT-SciSciNet huggingface dataset:
Data Mining Behavioral Transitions in Open Source Repositories

Open-source repository data can be automatically mined using sequence mining methods to provide high-level feedback on project status. GitHub.com projects are acquired, sequence-mined, clustered, and regressed to analyze project characteristics. Such results can be presented to project managers, as part of a display generated by an automated monitoring system. Such monitoring systems provide high-level feedback in real-time. This project is a preliminary step in a larger research project aimed at understanding and monitoring FLOSS projects using this process modeling approach.
Peroxidase-catalysed rupture of the CF bond as and indicator reaction for enzyme immunoassay

Abstract A fluoride ion-selective electrode is utilized as a sensor for the kinetic determination of peroxidase label in enzyme immunoassays. The method is based on a sandwich enzyme-linked immunosorbent assay (ELISA) technique, the peroxidase-catalysed rupture of the covalent CF bond in 4-fluorophenol and the subsequent release of fluoride ions. The determination of human immunoglobulin G (lgG), human α-fetoprotein (AFP) and human placental lactogen (HPL) was investigated. The potentiometric measurement of the rate of release of fluoride ion within 5 min provided a direct correlation with the concentration of analyte present in the sample. The concentration ranges investigated for the analytes were IgG 30 μg l−1–10mg l−1, AFP 5–500 μg l−1 and HPL 60 ng l−1–1 mg l−1. Under the given experimental conditions, the detection limits were IgG 30, AFP 12.8 and HPL 1 μg l−1. Replacing the rate method with the fixed-time mode (15–30 min) did not improve the detection limits. The performance of the present method was found to be comparable to that of the spectrophotometric detection technique.
Matrix-Assisted Laser Desorption Fourier Transform Mass Spectrometry for Biological Compounds

The recent development of matrix-assisted UV laser desorption (LD) mass spectrometry has made possible the ionization and detection of extremely large molecules (with molecular weights exceeding 100,000 Daltons) [1,2]. This technique has generated enormous interest in the biological community for the direct examination of large peptides and oligonucleotides. Although this matrix-assisted ionization method has been developed and used almost exclusively with time-of-flight (TOF) mass spectrometers, research is currently in progress to demonstrate this technique with trapped ion mass spectrometers, such as Fourier transform ion cyclotron resonance mass spectrometry (FTMS). The potential capabilities of FTMS for wide mass range, high resolution measurements, and ion trapping experiments (for ion-molecule reactions and MSn experiments) suggest that this instrumental technique should be useful for the detailed structural characterization of large ions generated by the matrix-assisted technique. We have recently demonstrated that matrix-assisted ultraviolet laser desorption, with either 266 or 355 nm radiation, can be successfully used with FTMS for the ionization of small peptides [3]. The objective of this report is to summarize the application and current limitations of matrix-assisted laser desorption FTMS for the characterization of peptides and oligonucleotides.
Developing Leadership Skills in Software Engineering Students Through an Undergraduate Research Program

This paper describes an undergraduate research program with a strong software engineering component that has been in place at Illinois Institute of Technology for the last several years. The program model is applicable to a variety of educational institutions, and can serve as a powerful tool for preparing undergraduates to become effective leaders in industry and academia. Success metrics include: the high percentages of participants (including a substantial number of women and minority students) who have enrolled in graduate school, obtained software engineering positions with industry leaders, and co-authored published research papers. We report on the program and its mechanisms for leadership skill development. We also discuss the software engineering component of the program, the impact of the program on software engineering education in our department, and the effects of the program on student development and career goals.
Serum lipoproteins; chemical and enzymatic studies.

The larger lipoproteins of Sf greater than 10 also contain triglycerides. The action of lipases on these lipoproteins, either heparin-induced clearing factor, pancreatic lipase, or gastric lipase, yields fatty acids, glycerol, and smaller lipoproteins. Crude clearing factor attacks monoglycerides and triglycerides and is inactiveagainst several esters which plasma esterases attack. Albumin, plasma esterases, and probably other components are needed for optimal clearing factor activity. Low concentrations of diisopropyl fluorophosphate (DFP), a substance inhibiting most hydrolytic enzymes, inactivate crude clearing factor. Stoicheometric calculations made from this experiment indicate further the enzymatic nature of clearing factor. Evidence that clearing factor is different from other lipases and from esterases found in plasma is presented. Studies with purified lipoproteins are needed to determine what alterations, if any, occur in smaller lipoproteins. The separation and purification of lipoproteins by chemical and ultracentrifugal means are described. Whole human plasma separated by Cohn9s methods 6 and 9 serves as starting material for the preparation of α1 α2 β and Sf 10 and greater lipoproteins. Studies of lipoproteins may give clues to the varied diseases associated with deranged lipid metabolism, such as xanthomatosis and atherosclerosis.
A twisted base? The role of arginine in enzyme-catalyzed proton abstractions

Abstract Arginine residues are generally considered poor candidates for the role of general bases because they are predominantly protonated at physiological pH. Nonetheless, Arg residues have recently emerged as general bases in several enzymes: IMP dehydrogenase, pectate/pectin lyases, fumarate reductase, and l -aspartate oxidase. The experimental evidence suggesting this mechanistic function is reviewed. Although these enzymes have several different folds and distinct evolutionary origins, a common structural motif is found where the critical Arg residue is solvent accessible and adjacent to carboxylate groups. The chemistry of the guanidine group suggests unique strategies to lower the p K a of Arg. Lastly, the presumption that general bases must be predominantly deprotonated is revisited.
Solving nonlinear optimization problems with fuzzy relation equation constraints

Abstract An optimization model with a nonlinear objective function subject to a system of fuzzy relation equations is presented. Since the solution set of the fuzzy relation equations is in general a non-convex set, when it is not empty, conventional nonlinear programming methods are not ideal for solving such a problem. In this paper, a genetic algorithm (GA) is proposed. This GA is designed to be domain specific by taking advantage of the structure of the solution set of fuzzy relation equations. The individuals from the initial population are chosen from the feasible solution set and are kept within the feasible region during the mutation and crossover operations. The construction of test problems is also developed to evaluate the performance of the proposed algorithm.
Semiparametric inference with a functional-form empirical likelihood

A functional-form empirical likelihood method is proposed as an alternative method to the empirical likelihood method. The proposed method has the same asymptotic properties as the empirical likelihood method but has more flexibility in choosing the weight construction. Because it enjoys the likelihood-based interpretation, the profile likelihood ratio test can easily be constructed with a chi-square limiting distribution. Some computational details are also discussed, and results from finite-sample simulation studies are presented.
GABA-to-ACh ratio in basal forebrain and cerebral cortex varies significantly during sleep.

Study objectives GABAergic and cholinergic transmission within the basal forebrain and cerebral cortex contribute to the regulation of sleep and wakefulness. In contrast to levels of acetylcholine (ACh), levels of endogenous GABA in basal forebrain and cortex during sleep and wakefulness have not previously been quantified. This study (1) tested the hypothesis that there are differential, state-specific changes in GABA levels within the substantia innominata (SI) region of the basal forebrain and somatosensory cortex; and (2) quantified the ratio of GABAergic to cholinergic transmission in the SI, cortex, and pontine reticular formation during rapid eye movement sleep (REM), non-REM sleep (NREM), and wakefulness. Design Within/between subjects. Setting University of Michigan. Patients or participants Adult, male, purpose bred cats (n = 5). Interventions In vivo microdialysis, high performance liquid chromatography, electrophysiological recordings. Measurements and results In the SI, GABA levels were significantly greater during NREM (17%) than during REM. In the cortex, GABA levels were significantly greater during NREM than during wakefulness (39%) and REM (63%). During prolonged wakefulness, there was a linear increase in cortical GABA levels, and the amount of time spent awake accounted for 87% of the variance in GABA. The GABA-to-ACh ratio was largest during NREM for all brain regions. REM was characterized by a 68% decrease in the GABA-to-ACh ratio across brain regions, always due to a decrease in GABA levels. Conclusion Three of the brain regions that comprise the anatomically distributed, sleep-generating network have in common a GABA-mediated, sleep-dependent decrease in the GABA-to-ACh ratio.
Structural alloys for superconducting magnets in fusion energy systems

Abstract The behaviour of selected alloys for superconducting magnet structures in fusion energy systems is reviewed with emphasis on the following austenitic stainless steels (AISI grades 304, 310S and 316), nitrogen-strengthened austenitic stainless steels (types 304LN, 316 LN and 21Cr6Ni9Mn) and aluminum alloys (grades 5083, 6061 and 2219). The mechanical and physical properties of the selected alloys at 4 K are reviewed. Welding, the properties of weldments, and other fabrication considerations are briefly discussed. The available information suggests that several commercial alloys have adequate properties at 4 K and sufficient fabrication characteristics for the large magnet structures needed for fusion energy systems.
765 ASSOCIATION OF PLASMID-MEDIATED ANTIBIOTIC RESISTANCE AND ENTEROTOXIN PRODUCTION IN AN ESCHERICHIA COLI ENTEROPATHOGFNIC FOR CHILDREN

Enterotoxigenic Escherichia coli (tox+ E. coli) isolated from children in the Philippines are frequently resistant to multiple antibiotics. In bacterial conjugation experiments a heat-labile (LT) tox+ E. coli 719B5 (018 ab:H27) transfered resistance to streptomycin and tetracycline to an E. coli K12 recipient; all of the transconjugants selected for streptomycin resistance were also resistant to tetracycline and LT+; ninety percent of transconjugants selected for tetracycline resistance were LT+ but only 20 percent were resistant to streptomycin. Resistant and LT+ transconjugants contained plasmids of approximately 120 and 60 megadaltons whereas resistant but LT− transconjugants contained only one plasmid of 60 megadaltons as determined by agrose gel electrophoresis. In P1 transduction experiments resistance to streptomycin and tetracycline and the ability to produce LT were transduced together, suggesting that the genes coding for antibiotic resistance and enterotoxigenicity are on the same plasmid. Resistant streptomycin and tetracycline and LT+ transductants contain plasmids of 60 megadaltons. These experiments suggest that the genes coding for LT production, and resistance to streptomycin and tetracycline are located on a 60 megadalton segment of DNA which may associate with a larger plasmid during bacterial conjugation.
S K-Edge X-ray Absorption Spectroscopic Investigation of the Ni-Containing Superoxide Dismutase Active Site: New Structural Insight into the Mechanism

Superoxide dismutases protect cells from the toxic effects of reactive oxygen species derived from superoxide. Nickel-containing superoxide dismutases (NiSOD), found in Streptomyces species and in cyanobacteria, are distinct from Mn-, Fe-, or Cu/Zn-containing SODs in amino acid sequence and metal ligand environment. Sulfur K-edge X-ray absorption spectroscopic investigations were carried out for a series of mono- and binuclear Ni model compounds with varying sulfur ligation, and for oxidized and reduced NiSOD to elucidate the types of Ni-S interactions found in the two oxidation states. The S K-edge XAS spectra clearly indicate the presence of Ni(III)-bound terminal thiolate in the oxidized enzyme and the absence of such coordination to Ni(II) in the peroxide-reduced enzyme. This striking change in the S ligation for Ni with redox suggests that, upon peroxide reduction, an electron is transferred to the Ni(III) site and the terminal thiolate becomes protonated, providing an efficient mechanism for proton-coupled electron transfer.
Shawl lapel aortoplasty

We describe a simple method of remodeling an ascending aorta that has dilated in response to a stenotic aortic valve. It provides excellent exposure for valve replacement and avoids the use of substantial prosthetic material in effecting a secure, facile closure.
Some New Values of Atomic Masses, Principally in the Region of 82 Neutrons

Some new mass comparisons are described which lead to atomic mass values for twenty-nine stable nuclides. There is shown to be a definite mass effect associated with the closing of the 82 neutron shell and probably also with the closing of the 58 proton shell. There is evidence that the minimum of the packing fraction curve occurs at $_{28}\mathrm{Ni}^{62}$. Recent microwave data are used to obtain the masses of ${\mathrm{Ge}}^{74}$ and ${\mathrm{Ge}}^{76}$ from the mass spectrographically determined masses of ${\mathrm{Ge}}^{70}$ and ${\mathrm{Ge}}^{72}$.
Packaging of the bacteriophage λ chromosome: Effect of chromosome length

We performed helper-packaging experiments to investigate the relation between chromosome length and efficiency of packaging of the bacteriophage λ chromosome. In these experiments, repressed tandem prophages were packaged during lytic growth of a heteroimmune helper phage. The prophage chromosome from which packaging was initiated contained a cohesive end site (cos) duplication so that depending on which of the two sites is attacked, either a duplication or haploid chromosome was packaged. With random initiation at cos sites, the yield of duplication and haploid chromosomes is a measure of the relative efficiency of packaging of the two lengths. A number of such comparisons resulted in several conclusions. In the length range from 1.05 to 0.80, where the λ+ length is 1.00, chromosomes were packaged with constant efficiency. There was an upper limit to efficient packaging: Chromosomes with a length of 1.088 were packaged with decreased efficiency (ca. 20%). Physical studies showed that the phage particles with oversized chromosomes were fully infectious. In the vicinity of length = 0.75, there was a lower limit below which efficiency of packaging also decreased. A fraction of the particles bearing short chromosomes was not infectious, perhaps due to an injection defect. The relevance of these observations to λ DNA packaging and evolution is discussed.
Toll price elasticities estimated from a sample of U.S. residential telephone bills

Abstract Demand models for four categories of toll calls are estimated from a sample of U.S. residential telephone bills. Besides the novelty of the data set, innovations in the analysis include the use of a call concentration index constructed from a household's itemized individual calls, plus variables representing choice of IX carrier and the presence or absence of an optional calling plan. A principal finding is that price elasticity and call concentration are inversely related.
Distortional Energy of Composite Materials

IT IS THE PURPOSE of this communication to reflect on a quantity idly referred to as “distortional energy” in contemporary composites technology. While the use of this term to generically classify quadratic failure surfaces has become so prevalent that compilation of literature citations is unnecessary, one can cite specific references in which the quantity has been employed in relation to studies of material failure, e.g., [1, 2, 3]. We shall argue that the term “distortional energy” discussed in the latter references is a complete misnomer and has no physical significance except when used in connection with isotropic material behavior. We shall also suggest a more satisfying definition of the distortional energy of an orthotropic medium.
Significance of Computed Tomography Pathology in Chronic Rhinosinusitis

Objectives/Hypothesis Multiple reports show that the extent of disease on computer tomography (CT) of the sinuses does not correlate with patients' subjective sinus symptom scores. In the current study, sinus symptom scores of patients with normal findings on sinus CT scans are compared with sinus symptom scores of patients with chronic rhinosinusitis and with disease on CT of the sinuses. The objective is to determine the significance of CT disease in patients with chronic rhinosinusitis. Study Design Prospective collection of data of consecutive patients seen for possible sinusitis. Methods Prospective data at a tertiary medical center were collected over an 8-month period. Computed tomography scans were graded according to Lund and MacKay, and patients were asked to grade each of the major and minor rhinosinusitis symptoms listed by the Rhinosinusitis Task Force from 0 to 10. A score of 0 was given for no symptom at all, and 10 indicated the most severe extent of a symptom. Results Twenty-seven patients with sinus complaints had normal findings on sinus CT scans. The average scores for major and minor rhinosinusitis symptoms were 18.6 and 15, respectively. Twenty-six patients with sinus complaints had disease on CT of their sinuses. The average scores for major and minor rhinosinusitis symptoms for these patients were 42.9 and 22, respectively. Higher symptom scores were seen in the patients with CT disease, and the differences between these two groups were statistically significant (major symptom, P = .000001; minor symptom, P = .02). Patient symptom scores did not correlate with extent of disease on CT as previously reported (r = 0.16). Conclusion The presence of CT disease translates to higher patient symptom scores compared with symptom scores of patients without CT disease.
Application of full wave analyses to electromagnetic scattering by multiple-scale anisotropic models of rough surfaces for industrial and climatic remote sensing

For industrial and weather forecasting purposes it is often necessary to employ electromagnetic waves (optical to microwave wavelengths) to remotely sense manmade or naturally generated rough surfaces. These surfaces are generally anisotropic and contain multiple scales of roughness. For example sheet metal used in industrial applications are usually sandblasted before painting, while rough sea surfaces with swell are generated by fully developed local winds as well as high intensity winds from more remote sources. Several hybrid analytical techniques based on small perturbation and physical/geometrical optics approaches have been used to determine the scatter cross sections for these multiple scale anisotropic models of rough surfaces. However, these hybrid solutions critically depend on the choices of the spatial wave numbers where spectral splitting is assumed between the different scales of rough surfaces. Fully polarimetric unified full wave solutions have been derived for the scattered fields from these multiple scale anisotropic models of rough surfaces. The rough surfaces are regarded as large (compared to correlation length) patches of rough surfaces with arbitrary orientations and the scattering cross sections are shown to be stationary over a wide range of patch (pixel) sizes. Unlike the perturbation solution the full wave solutions are invariant to coordinate transformations (translations and rotations) and are not restricted to surfaces with small mean square heights (compared to wavelength).© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Least squares fitting of planes to surfaces using dynamic programming

Dynamic programming has recently been used by Stone, by Bellman and by Gluss to determine the closest fit of broken line segments to a curve in an interval under the constraint that the number of segments is fixed. In the present paper successive models are developed to extend the method to the fitting of broken plane segments to surfaces z = g(x, y) defined over certain types of subareas of the (x, y)-space. The first model considers a rectangular area, with the constraint that the plane segments are defined over a grid in the (x, y)-space. It is then shown how this model may be incorporated into an algorithm that provides successive approximations to optimal fits for any type of closed area. Finally, applications are briefly described.
The effect of high ambient temperature on timing behavior in rats.

The present experiments demonstrated a reliable within-session increase in rectal temperature (Tre) at 25° C during stable differential-reinforcement-of-low-rate (DRL) performance. The thermal response was found to be independent of the DRL value and reinforced DRL performance, but dependent on the state of the animal's deprivation. Exposure to a 35°-C environment increased the post-session Tre significantly above the 25°-C post-session Tre for seven of eight subjects. Response and reinforcement rate at 35° C was found to be independent of DRL value, although it decreased as DRL value increased at 25° C. A discriminative stimulus used to mark the end of the interval increased the reinforcement rate at 25° C but provided no advantage at 35° C. Measurement of the pattern of responding during DRL performance revealed increases in the proportion of long interresponse times at 35° C. Reinforcement rate was found to decrease progressively at 35° C, reaching a minimum within 40 to 50 min of the 90-min session. Visual observation of overt behaviors during DRL performance at 35° C revealed a reduction in the frequency of overt behavior, characteristic of 25°-C performance, and a time-dependent increase in the probability of an alternative set of behaviors.
Impulse-mowing anisotropic diffusion filter for image denoising

Image denoising is still a challenging problem, particularly when the noise is made combining Gaussian noise and random-valued impulses. This article is concerned with diffusion-based denoising methods which can suppress such complicated noises effectively, preserving fine structures. We introduce a novel impulse-mowing anisotropic diffusion (IMAD) filter to cut out impulses and local maxima/minima without affecting surrounding pixel values. It has been numerically verified that the suggested mean filter carries out both mowing impulses and restoring fine structures satisfactorily. It outperforms nonlinear median filters, measured in PSNR and visual inspection.
Treatment of inflammatory arthritis by synovial ablation: a comparison of the holmium: YAG laser, electrocautery, and mechanical ablation in a rabbit model.

Background and Objective Although the majority of patients with immune-mediated inflammatory arthritis are managed conservatively, some patients may require synovectomy if they have persistent pain secondary to chronic unresponsive swelling of a joint. In this study, three methods of synovial ablation using laser energy, electrocautery, and mechanical debridement were compared in an in vivo chronic synovitis rabbit model. Study Design/Materials, and Methods: In the first phase of this study, the optimal laser energy/pulse frequency combination for synovial ablation in this model was determined. In the study's second phase, 48 mature rabbits were then divided into four equal groups: laser synovectomy, electrocautery synovectomy, mechanical synovectomy, and control. Chronic synovitis was induced in both stifles of all treatment groups and in the right stifle of the control rabbits. Synovectomy was performed on one stifle of each rabbit; the contralateral stifle served as a sham-operated control. Six rabbits per group were euthanized 2 weeks and 3 months after surgery, respectively. Results There were no differences among groups in synovial fluid parameters, except at 2 weeks, when the electrocautery group had significantly more white blood cells than the laser and mechanical debridement groups. Histologic examination revealed that mechanical debridement resulted in significantly more synovial hemorrhage, capillary dilatation, plasma cell infiltration, lymphocyte infiltration, joint capsular defects, and poorer synovial ablation than ablation achieved with either laser energy or electrocautery. Conclusions Laser energy and electrocautery achieved similar results when used for ablative purposes, although electrocautery did not achieve the same degree of synovial ablation as laser energy. © 1996 Wiley-Liss, Inc.
The Moberg volar advancement flap for digital reconstruction.

The volar advancement flap described by Moberg in 1964 has been used to restore normal sensation to soft tissue deficits of the thumb. Application of this same technique for finger tip injuries was later suggested by Snow, but differences in digital blood supply led to dorsal tip necrosis and selection of other reconstructive techniques by many surgeons. Other methods have the disadvantages of widened two-point discrimination, a tender pulp scar, or an unacceptable donor site. The volar advancement flap applied to fingers restores normal to nearly normal sensation, an adequate pulp with minimal deformity. Our experience with the volar advancement flap in 69 digits from 1969 to 1978 is reviewed. Preservation of the dorsal perforating vessels is most important in successfully executing this procedure. No dorsal tip or flap necrosis occurred. Two-point discrimination was normal or within 2 mm of contralateral values in every digit. Full range of motion, or less than 5° extension loss, was recorded in all fingers that were normal prior to operation. Our results suggest this to be a safe as well as effective adjunct in the treatment of finger tip injuries.
Calculation of K-vacancy production by relativistic projectiles

Cross sections for the production of K vacancies by relativistic projectiles are calculated using the plane-wave Born approximation. Electronic 1s and continuum states are represented using semirelativistic Darwin wave functions. The calculated cross sections are in good agreement with measurements using 4.88-GeV protons, and also very high-energy (50--900-MeV) electrons. Simple formulas are given to calculate the cross section for projectile energies greater than approx. 3Mc/sup 2/.
Allocation, distribution, and scale: towards an economics that is efficient, just, and sustainable

Abstract The practical policy of issuing tradeable permits for depletion and pollution requires for its implementation the clear separation of the three basic economic goals of efficient allocation, equitable distribution, and sustainable scale. Economic theory needs to catch up with policy in recognizing that scale issues cannot be reduced to either allocation or distribution.
Integrating Data, Resources, and Capabilities in the Great Lakes: Impacting Federal, State, Tribal, Local, and Private Partnerships through the Area Committee

ABSTRACT The Great Lakes of the United States and Canada comprise, essentially, a closed freshwater system in which over 31 million individuals coexist within the industrial, agricultural, and recreational economies of the region. With annual replacement rates of less than one percent, pollutants introduced into the Great Lakes can, over time, concentrate, resuspend, and infiltrate the biologic system through annual lake turnover, navigational dredging, and cycling through the food web. Past spills of oil and hazardous substances resulted in highly elevated levels of byproducts such as polycyclic aromatic hydrocarbons (PAHs), heavy metals like mercury, and toxics including polychlorinated biphenyls (PCBs). These have resulted in stream degradation, fish consumption advisories, fish kills, and beach closures, with impacts felt at the local, watershed, regional, and binational levels. Traditionally, in the Great Lakes, local and regional policy groups have interacted with the Federal government through such...
Radionuclide Mineral Studies,4. Studies on the Metabolism of Ca45 by the Chick

Abstract INTRODUCTION THE metabolism of calcium by chicks has been studied by many investigators. Through these studies major contributions have been made to the overall picture of calcification, but many important areas remain obscure. The absorption of calcium by the chick is influenced by vitamin D3 (Migicovsky and Emslie, 1950; Patrick and Bacon, 1957) and vitamin D has been suggested as an activator of the enzyme alkaline phosphatase (Zetterstrom and Ljunggren, 1951). This enzyme is found in several body tissues, including the intestinal mucosa, but has not yet been shown to be implicated with calcium absorption. These experiments were made to study the absorption of Ca45 by various breeds of chicks as influenced by vitamin D3, age, and certain intermediates of normal metabolism. EXPERIMENTAL PROCEDURE The experimental chicks were hatched from New Hampshire (N. H.), New Hampshire X White Leghorn (N. H. X W. L.), and White Leghorn (W. L.) breeding …
Some calculations in lattice gauge theory

Abstract We look at the action proposed by Wilson on a lattice and calculate static constants like f π and two-body decay amplitudes in a certain approximation. Results are good to factors of four to six. There is good agreement for some of the predicted meson masses.
Spectral Models of Kuiper Belt Objects and Centaurs

We present models of the spectral reflectances of groups of outer Solar System objects defined primarily by their colors in the spectral region 0.4–1.2 µm, and which have geometric albedo ~0.04 at wavelength 0.55 µm. Our models of the groups with the strongest reflectance gradients (reddest colors) use combinations of organic tholins. We test the hypothesis that metal-reddened igneous rock-forming minerals contribute to the red colors of Centaurs and KBOs by using the space-weathered lunar soil as one of the components of our models. We find that our models can admit the presence of moderate amounts of space-weathered (metal-reddened) minerals, but that they do not require this material to achieve the red colors of the reddest outer Solar System bodies. Our models with organic tholins are consistent with the results of other investigators.
Observation of a vortex-glass phase in polycrystalline YBa 2 Cu 3 O 7-x in a magnetic field

We report the results of temperature- and field-dependent transport measurements on sintered, polycrystalline samples of ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathit{x}}$. A study of the E-J curves indicates a second-order phase transition, at low current density in the coupling of the grains, that exhibits the scaling behavior predicted for a vortex glass. The ohmic resistance at low current is observed to vanish at a nonzero temperature, and the E-J curves exhibit power-law behavior at that temperature. Below this temperature the E-J curves are consistent with a true critical current with zero linear resistance. The qualitative features of the data and the values of the critical exponents are consistent with the predictions of the vortex-glass theory. Our findings cannot be explained by the predictions of conventional flux-creep models.
The Development of the STEM Career Interest Survey (STEM-CIS)

Internationally, efforts to increase student interest in science, technology, engineering, and mathematics (STEM) careers have been on the rise. It is often the goal of such efforts that increased interest in STEM careers should stimulate economic growth and enhance innovation. Scientific and educational organizations recommend that efforts to interest students in STEM majors and careers begin at the middle school level, a time when students are developing their own interests and recognizing their academic strengths. These factors have led scholars to call for instruments that effectively measure interest in STEM classes and careers, particularly for middle school students. In response, we leveraged the social cognitive career theory to develop a survey with subscales in science, technology, engineering, and mathematics. In this manuscript, we detail the six stages of development of the STEM Career Interest Survey. To investigate the instrument's reliability and psychometric properties, we administered this 44-item survey to over 1,000 middle school students (grades 6–8) who primarily were in rural, high-poverty districts in the southeastern USA. Confirmatory factor analyses indicate that the STEM-CIS is a strong, single factor instrument and also has four strong, discipline-specific subscales, which allow for the science, technology, engineering, and mathematics subscales to be administered separately or in combination. This instrument should prove helpful in research, evaluation, and professional development to measure STEM career interest in secondary level students.
Trade-offs among the elements of flexibility: a comparison from the automotive industry

Abstract Flexibility has long been recognized as a manufacturing capability that has the potential to impact the competitive position and the business performance of an organization ( [1] : Cox Jr, T. Toward the measurement of manufacturing flexibility. Production and Inventory Management Journal 1989; First Quarter:68–72, [2] : De Meyer A, Nakane J, Miller JG, Ferdows K. Flexibility: the next competitive battle. Strategic Management Journal 1989;10:135–144). This recognition, however, has not led to a unanimous approach to flexibility. For example, Japanese manufacturers emphasize flexibility more than North American or European manufacturers ( [2] : De Meyer A, Nakane J, Miller JG, Ferdows K. Flexibility: the next competitive battle. Strategic Management Journal 1989;10:135–144). While this finding provides insight into the strategic choices made by these organizations in these countries, it does not provide an in-depth comparison of specific aspects of flexibility that are leveraged and emphasized differently. Such a comparison is necessary, however, if flexibility is to be more fully understood. This paper takes a step in that direction by first breaking down the concept of flexibility into its constituent elements and dimensions. Then we introduce the notion of looking at flexibility as a capability that must be planned for and built by a firm over a period of time along these constituent elements and dimensions. Questions are subsequently raised regarding whether trade-offs occur among different elements for a given flexibility dimension. We use industry wide as well as firm-specific qualitative data from the automotive industry to answer these questions, and show that several key aspects of manufacturing flexibility have been acquired and leveraged differently by American and Japanese producers. While linkages to business performance are not directly explored, our analysis reveals that even within the same industry, firms from different countries do indeed follow different strategies to developing their flexibility capability. Implications of these results for managerial practice, along with avenues for further research in this area, are also presented.
Complexes of carbohydrates with aluminate ion. Aldose-ketose interconversion on anion-exchange resin (aluminate and hydroxide forms)☆

Kinetic parameters for aldose and ketose transformations in the d-glucose-d-mannose-d-fructose system at 27° on aluminate resin and hydroxide resin were obtained. On both resins, hydroxide ion functions as the catalyst for isomerization. By forming a complex with d-fructose, resin-bound aluminate ion stabilizes the ketose and permits high yields (up to 72%) of d-fructose from d-glucose. The effect of temperature on d-glucose-to-d-fructose conversion was studied; lower temperatures give the higher maximum yields. Maltose is converted into maltulose in moderately high yield (63%) at 24° on aluminate resin; higher yields are not possible at this temperature because of a marked tendency for maltulose to undergo elimination of d-glucose at C-4.
Multidimensional nuclear magnetic resonance methods for protein studies

Abstract Nuclear magnetic resonance (NMR) technology has advanced significantly over the past few years. After the initial development of three- and four-dimensional NMR spectroscopy, several important improvements on these experiments have been made; these offer significantly higher sensitivity and improved resolution, resulting in additional structural constraints. Other methodological improvements now make it possible to obtain complete resonance assignments, even in partially denatured proteins, opening new windows for studying the protein folding problem.
A rapamycin-sensitive signaling pathway contributes to long-term synaptic plasticity in the hippocampus

Many forms of long-lasting behavioral and synaptic plasticity require the synthesis of new proteins. For example, long-term potentiation (LTP) that endures for more than an hour requires both transcription and translation. The signal-transduction mechanisms that couple synaptic events to protein translational machinery during long-lasting synaptic plasticity, however, are not well understood. One signaling pathway that is stimulated by growth factors and results in the translation of specific mRNAs includes the rapamycin-sensitive kinase mammalian target of rapamycin (mTOR, also known as FRAP and RAFT-1). Several components of this translational signaling pathway, including mTOR, eukaryotic initiation factor-4E-binding proteins 1 and 2, and eukaryotic initiation factor-4E, are present in the rat hippocampus as shown by Western blot analysis, and these proteins are detected in the cell bodies and dendrites in the hippocampal slices by immunostaining studies. In cultured hippocampal neurons, these proteins are present in dendrites and are often found near the presynaptic protein, synapsin I. At synaptic sites, their distribution completely overlaps with a postsynaptic protein, PSD-95. These observations suggest the postsynaptic localization of these proteins. Disruption of mTOR signaling by rapamycin results in a reduction of late-phase LTP expression induced by high-frequency stimulation; the early phase of LTP is unaffected. Rapamycin also blocks the synaptic potentiation induced by brain-derived neurotrophic factor in hippocampal slices. These results demonstrate an essential role for rapamycin-sensitive signaling in the expression of two forms of synaptic plasticity that require new protein synthesis. The localization of this translational signaling pathway at postsynaptic sites may provide a mechanism that controls local protein synthesis at potentiated synapses.
Vertical Migration and Mortality of Marine Benthos in Dredged Material: A Synthesis

This account describes the comparative response of four species of benthic invertebrates to burial in terms of vertical migration and mortality, and provides a synthesis of studies and recommendations upon which to assess future impacts. The species featured were the bivalve Mercenaries mercenaria, the amphipod crustacean Parahaustorius longimerus, and the polychaetes Scoloplos fragilis and Nereis succinea. There was evidence of synergistic effects on burrowing activity and mortality with changes in time of burial, sediment depth, sediment type and temperature. In sediment with silt-clay, N. succinea was the most resistant species followed by M. mercenaria, S. fragilis and P. longimerus. In sediment without silt-clay the order of percent mortality was reversed. Studies of surface water chemistry and sediment geochemistry showed that dissolved oxygen decreased significantly and ammonia and sulfide increased significantly between the surface and below 2.0 cm within a 15-day period. Based on these results and physiological tolerances from the literature it was concluded that M. mercenaria and N. succinea would be relatively resistant to chemical effects of spoil disposal, whereas S. fragilis and P. longimerus would be less resistant to such effects. Vertical migration of benthic invertebrates through dredge disposal can be a viable mechanism of recolonization under certain conditions. Some effects of burial of benthos can be predicted based on morphology, behavior and physiology. These biological features were discussed with examples dealing with molluscs, crustaceans, and polychaetes. Finally, recommendations were made concerning the type of studies to provide additional data to aid management agencies in decision making about future dredging and disposal practices.
MD1 - The transfer chemical laser: A review of recent research

Processes of collisional redistribution of vibrational energy prevail over specific chemical reaction mechanisms in the determination of vibrational energy distributions in present hydrogen halide CW chemical lasers. Despite the resultant relatively modest departures from the Maxwell-Boltzmann form for the distribution of energy among the vibrational levels of product molecules, selective vibrational energy transfer to a second molecule (e.g., CO 2 ) can be an effective method for the production of complete population inversion by the energy release of chemical reactions. This concept has been the basis for the development of the transfer chemical laser (TCL) during the past three years. A summary of recent progress in the development of CW and pulsed DF-CO 2 transfer chemical lasers is presented. An experiment designed to produce multikilowatt supersonic DF-CO 2 chemical laser operation with full atmospheric recovery in the exhaust gases is discussed. Recent measurements of key vibrational energy transfer processes are reviewed; such measurements have greatly clarified the kinetic aspects of the HF, DF, HF-CO 2 , DF-CO 2 , HCl-CO 2 and HBr-CO 2 chemical lasers. The very large values for these key rates (corresponding to about 20 to 200 collisions) can be attributed to energy transfer to rotation under the influence of a sizable attractive intermolecular potential well and enhanced repulsion at close range.
Response to Comment on ``Rapid Uplift of the Altiplano Revealed Through 13 C- 18 O Bonds in Paleosol Carbonates''

Clumped-isotope thermometry measurements of carbonate samples deposited in the Bolivian Altiplano as early as 28.5 million years ago and buried up to ~5000 meters deep exhibit no relationship between burial depth and apparent temperature, and largely yield temperatures within error of plausible Earth-surface conditions. These results counter the predictions of Sempere et al. and support our previous conclusions regarding the uplift of the Altiplano.
Sharing experiences to learn user characteristics in dynamic environments with sparse data

This paper investigates the problem of estimating the value of probabilistic parameters needed for decision making in environments in which an agent, operating within a multi-agent system, has no a priori information about the structure of the distribution of parameter values. The agent must be able to produce estimations even when it may have made only a small number of direct observations, and thus it must be able to operate with sparse data. The paper describes a mechanism that enables the agent to significantly improve its estimation by augmenting its direct observations with those obtained by other agents with which it is coordinating. To avoid undesirable bias in relatively heterogeneous environments while effectively using relevant data to improve its estimations, the mechanism weighs the contributions of other agents' observations based on a real-time estimation of the level of similarity between each of these agents and itself. The "coordination autonomy" module of a coordination-manager system provided an empirical setting for evaluation. Simulation-based evaluations demonstrated that the proposed mechanism outperforms estimations based exclusively on an agent's own observations as well as estimations based on an unweighted aggregate of all other agents' observations.
Saturn's Rings II. Particle Sizes Inferred from Stellar Occultation Data

Abstract We derive power-law particle size distributions for each of Saturn's main ring regions, using observations of the 3 July 1989 stellar occultation of 28 Sgr from Palomar, McDonald, and Lick observatories. We use the Voyager PPS δ Sco optical depth profile to estimate and then remove the directly transmitted signal from the 28 Sgr observations, leaving high SNR scattered light profiles at wavelengths of 3.9, 2.1, and 0.9 μm. The angular distribution of this diffracted signal depends on the ring particle size distribution: the sharpness of the forward lobe is set by the largest particles, while the overall breadth and amplitude of the scattered signal reflect the abundance of smaller, cm-sized particles. From a simple one-dimensional scattering model, we estimate characteristic particle sizes in the A, B, and C rings, and obtain a good match to the detailed structure of the observed scattered light profiles. To accommodate more realistic particle size distributions and to take proper account of the geometry of the occultation, we then develop a two-dimensional forward-scattering model. We assume for simplicity a single power law particle size distribution for each major ring region, and we determine the index q and lower and upper size cutoffs a min and a max that provide the best match to all three data sets in each region. Our results in the A and C rings are fairly consistent with values of q and a max derived from Voyager radio occultation (RSS) measurements (Zebker et al. 1985). We extend their results by determining lower limits to the particle size distributions and by probing the B Ring. We find a rather flat ( q =2.75) and narrow size distribution for both the inner A Ring and the B Ring, with a surprisingly large a min =30 cm. From the detailed shape of the scattered signal in the A and B rings, we find a max =20 m, a factor of two larger than the RSS result. The fraction of cm-sized particles increases between the inner and outer A Ring and is greatest in the C Ring, where a min =1 cm and q =3.1. Our upper size cutoffs are in excellent agreement with Showalter and Nicholson's (1990) estimates based on the statistical properties of the Voyager PPS occultation data, but the implied surface mass densities significantly exceed those derived from studies of density and bending waves, if the ring particles are made of solid ice.
The wave structure function in weak to strong fluctuations: an analytic model based on heuristic theory

The Rytov perturbation method can be used to derive analytic expressions governing statistical quantities of an optical wave propagating through the Earth's atmosphere. It is generally accepted that the validity of these expressions is restricted to the weak fluctuation regime, and that the wave structure function for plane and spherical waves obtained via the Rytov method is valid in all fluctuation regimes, for sufficiently small separation distances. Data from experimental results for the wave structure function as a function of the fluctuation strength for a fixed value of the separation distance indicate that the Rytov method does not accurately model the behaviour of the wave structure function in moderate to strong fluctuation regimes. This is similar to what is observed for the scintillation index. Recently, however, it was shown that the integral definition of the scintillation index obtained via the Rytov perturbation yields analytic expressions that are valid in all fluctuation regimes when a f...