cssi/SciSciGPT-SciSciNet huggingface dataset:
Green’s-function approach to quantum confinement

We present a rigorous means of computing the electronic properties of a confined system by perturbing the electronic properties of an unconfined, bulk system. Our approach focuses on the Green's function of the confined system. We explain why it is preferable to consider the confined Green's function rather than the confined energy eigenfunctions, and an expression for the change in the Green's function produced by quantum confinement is derived. Finally, we shift our focus to the eigenfunctions and derive approximate results for a spherical nanocrystal with a Green's function methodology.
Levels of 48Ti observed by the (d, α) reaction on 50V

Abstract The 50 V(d, α ) 48 Ti reaction was examined at 7.50 MeV bombarding energy with a resolution of 15 to 25 keV. Measurements were performed at several angles between 30° and 165°. Energy levels, several of which are new, up to 5.7 MeV of excitation were identified. The relation between observed (d, α ) cross sections and final state spins is examined. It is suggested that those 48 Ti levels which are strongly excited in the (d, α ) reaction have spins between 6 and 10.
Coadministration of Oral Levofloxacin With Agents That Impair Absorption: Impact on Antibiotic Resistance

Coadministration of oral divalent or trivalent cation-containing compounds with oral fluoroquinolones may impair fluoroquinolone absorption. Among 3,134 patients who received a course of oral levofloxacin, coadministration was significantly associated with subsequent identification of a levofloxacin-resistant isolate. Strategies to curb the emergence of fluoroquinolone resistance should include avoiding the coadministration of divalent or trivalent cation-containing compounds and fluoroquinolone.
Feminizing sex cord tumor with annular tubules in a boy with Peutz-Jeghers syndrome

tetralogy of Fallot and followed in most cases for 15 years, there were three malignancies, three benign tumors, and two hamartomas. Al though this incidence does not significantly exceed the expected number, two possibly radiogenic neoplasms did develop, i.e., acute myeloblastic leukemia and enchondroma of the sternum. Until we have more information from long-term followup studies, we recommend that steps be taken to shield as far as possible the thyroid and breast tissues of infants undergoing cardiac catheterization, by use of small-field, coned-down viewing instrumentation and lead shields where direct exposure cannot be avoided.
Temperature-induced incorporation of gramicidin A into lysolecithin micelles demonstrated by 13C NMR.

Lipid-protein interactions play a fundamental role in the organization and function of biological membranes. Gramicidin A, a pentadecapeptide, forms a transmembrane channel by adopting a singlestranded P-helical structure whose helix axis coincides with the channel axis [l-3]. It was proposed [4] that gramicidin A first forms large aggregates at the interface of the lipid bilayer then releases the aggregates that necessarily penetrate the lipid layer in order to form active channels. This aggregation could be viewed as the hydrophobic association of gramicidin A sidechains in an aqueous phase. Being familiar with elevated temperature inducing hydrophobic association in elastin peptides [5,6], it was our purpose to investigate whether or not elevated temperatures could drive the gramicidin A molecules to incorporate into micelles and result in transmembrane channels. Simple 13C spectra of lipid molecules could be utilized to monitor changes in chemical shifts and/or signal intensities of carbon resonances, if such changes were concurrent with the incorporation of gramicidin A molecules in the membrane systems. Therefore, we undertook to study the incorporation of gramicidin A in a micellar system of L-cr-lysolecithin in deuterated water as a function of temperature. The results are reported here.
Influence of Angler Exploitation on Black Crappie Population Structure in a Rural South Dakota Impoundment

ABSTRACT Anglers harvested approximately 122 black crappies (Pomoxis nigromaculatus)/ha at 18-ha Murdo Lake, South Dakota, in 1992. Based on a mean length of 26.2 cm for harvested black crappies, anglers likely harvested 36.1 kg/ha. The following spring (1993), proportional stock density (PSD) for black crappies collected with trap nets was 10—far lower than for any of the previous four years. Thus, we conclude that angling can have a substantial effect on the black crappie population in a small impoundment.
Socialism and Indian Economic Policy

Abstract This paper examines the interaction of socialist ideas and doctrines with Indian economic policy-making in the last three decades. It concludes with an analysis of the differences between ex-ante aspirations and the ex-post outcomes in regard to these socialist objectives.
Dietary curcumin post-treatment enhances the disappearance of B(a)P-derived DNA adducts in mouse liver and lungs

To study the post-treatment effects of dietary curcumin on the levels of benzo(a)pyrene [B(a)P]-induced DNA adducts, mice were administered oil or B(a)P and randomized into 7 subgroups after 24 h. One of the subgroups from both the oil and B(a)P groups was killed at 24 h while the remaining 6 subgroups were shifted to powdered control or 0.05% curcumin diet and killed after 24, 72 and 120 h (experiment 1), and 7, 14, and 28 days (experiment 2). Quantitative comparisons of BPDE-DNA nuclear adducts (area and intensity) in immunohistochemically stained lungs and liver sections was carried out by IHC profiler. A time-dependent decrease in the levels of adducts in B(a)P-treated animals was further enhanced by curcumin exposure compared to the levels in time-matched controls. To assess the contribution of apoptosis and cell proliferation in observed curcumin-mediated enhanced decrease of BPDE-DNA adducts, comparative evaluation of apoptosis and cell proliferation markers was undertaken. Results suggested enhancement of B(a)P-induced apoptosis in liver and lungs by curcumin during 24-120 h while no such enhancement was observed at 7-28 days. Results suggest curcumin-mediated enhancement in apoptosis (experiment 1) and adduct dilution (experiment 2) to be the reason for the observed higher decrease of BPDE-DNA adducts.
Metastable Superheated Ice in Liquid-Water Inclusions under High Negative Pressure.

In some microscopic inclusions (consisting of aqueous liquid and vapor) in minerals, freezing eliminates the vapor phase because of greater volume occupied by the resulting ice. When vapor fails to nucleate again on partial melting, the resulting negative pressure (hydrostatic tension) inside the inclusions permits the existence of ice I crystals under reversible, metastable equilibrium, at temperatures as high as +6.5°C and negative pressures possibly exceeding 1000 bars.
Zero Poisson’s Ratio Cellular Honeycombs for Flex Skins Undergoing One-Dimensional Morphing

Cellular honeycomb cores with overlying flexible face sheets have been proposed for use as flex skins for morphing aircraft. The cellular cores, which provide underlying support to the face sheets for carrying aerodynamic loads, must have low in-plane stiffness and high in-plane strain capability. For one-dimensional morphing applications such as span-, chord-, or camber-change, restraining the Poisson’s contraction (or bulging) that a conventional cellular honeycomb core would otherwise experience in the non-morphing direction results in a substantial increase in the effective modulus in the morphing direction. To overcome this problem, this article develops zero Poisson’s ratio hybrid and accordion cellular honeycombs. Cellular Material Theory is extended, and analytical solutions for the mechanical properties and global strains of the hybrid and accordion cellular honeycombs are developed. The analytical results show excellent agreement with ANSYS finite element results. Comparing the properties shows ...
Hydroelastic response of a circular tube in eccentric annular flows

This paper describes an experimental study of the hydroelastic response of a tube located concentrically and eccentrically, respectively, in a circular water-flow channel. Acceleration components in two orthogonal directions were measured at the midpoint of the test element by using a pair of accelerometers. The investigation included determination of natural frequencies, damping factors, rms displacements, and the variations of these dynamic quantities with eccentricity and mean axial flow velocity. The experimental data were processed into statistical forms, including power spectral density function and rootmean-square values. The results show that the natural frequency of the tube shifts as the eccentricity or flow velocity increases, that the damping in flowing water is greater than that in stationary water, and increases with increasing flow velocity and eccentricity, and that the rms displacement increases as the eccentricity and/or flow velocity increases.
The effects of temperature acclimation on the fatty acid composition of the nerve cord and fat body of the American cockroach, Periplaneta Americana

Abstract 1. 1. Fatty acid composition of the nerve cord and fat body of American cockroaches acclimated to 14, 22 or 30°C was determined by gas-liquid chromatography. 2. 2. Fifteen fatty acids were detected in the nerve cord; 10 were significantly affected by 7 days of temperature acclimation. 3. 3. Seventeen fatty acids were detected in the fat body; 5 were significantly affected by temperature acclimation. 4. 4. Low temperature acclimation resulted in an increase in weight % of 3 unsaturated fatty acids and a decrease in weight % of 3 saturated fatty acids in the nerve cord, but not in the fat body. 5. 5. The physiological significance of these fatty acid changes is discussed, including possible effects on insecticide toxicity.
Enhancement by food restriction of liver protein synthesis in the aging Fischer 344 rat

Age-related changes in liver protein synthesis of ad libitum fed and food-restricted SPF Fischer 344 rats have been measured. In ad libitum fed animals, valine incorporation increased from 3 to 6 mo of age, decreased to the 3-mo level at 12 mo, remained relatively constant through 18 mo, and then declined further at 24 mo of age. By 24 mo valine incorporation was 30% of the 6-mo value. Food restriction had no effect at 3 mo of age (6 wk of restriction) but at 6 mo the rate of valine incorporation was 35% greater than the control, an increment that was maintained throughout the life of the animal. Therefore, although food restriction does not prevent the age-related decline in protein synthesis, it does maintain the rate of liver valine incorporation at levels greater than those observed in the liver of the ad libitum fed animal.
Microstructure and properties of nanostructured thick CrN coatings

Abstract Thick polycrystalline CrN coatings (20 μm) were deposited at a high deposition rate (10 μm/h) using a highly ionized plasma generated by modulated pulsed power magnetron sputtering. The microstructure of the thick CrN coating was characterized using transmission electron microscopy. The coating exhibited a super dense microstructure with a grain size in the nanometer range of 100–150 nm. The thick CrN coating showed an average high hardness of 24 GPa, excellent adhesion and wear resistant.
Decision and information structures in regret models of judgment and choice

The use of the preference relation `selection of A and rejection of B is preferable to selection of B and rejection of A' is discussed. This contextual relation yields descriptive models of choice under uncertainty that explain many observed violations of classical single attribute utility theory. It is shown that successful use of this relation, for descriptive purposes, requires careful attention to elicitation of realistic decision situation structural models and pre- and post-decision information availability conditions within these models. Reservations with respect to use of the regret model for normative purposes, due to potential nontransitivities of the contextual relation, are discussed.
Trivalent Ion Hydrolysis Reactions: A Linear Free-Energy Relationship Based on Density Functional Electronic Structure Calculations

Metal ion hydrolysis is fundamental in aqueous chemistry because of the influence of coordinating hydroxide ions on reaction rates; examples include enhanced labilization of coordinating water molecules in hydrolyzed complexes and stabilization of oxidized products in electron-transfer reactions involving hydrolyzed reductants. Moreover, the role of metal hydrolysis reactions in defining a baseline for establishing trends in metal-ligand binding has motivated efforts toward comprehensive integration of M{sup z+}{sub x}OH{sub y} stability constants.
Far-Infrared Dielectric Function of Zincblende ZnS

The complex dielectric response function of zincblende ZnS is determined at 300 K by dispersive Fourier transform spectroscopy. The frequency range studied, 150 to 450 cm−1, spans the frequency of the q = O transverse optic (TO) phonon mode. The frequency dependence of the anharmonic self-energy function Γ(ν) of the q = 0 TO phonon is calculated from these data. The features observed in the spectrum of Γ(ν) are satisfactorily assigned to multi-phonon processes by comparison to theoretical lattice dynamics calculations for cubic ZnS. Par la methode de spectroscopie dispersive utilisant la transformee de Fourier, nous avons determine la fonction complexe de response dielectrique du ZnS a 300 K. La gamme de frequences etudiees, 150 a 450 cm−1, encadre la frequence du mode phonon optique transverse a q = 0. Les caracteristiques observees dans le spectre of Γ(ν) peuvent etre attribuees de maniere satisfaisante processus multi-phonon par comparaison avec les calculs de dynamique du reseau pour la forme cubique du ZnS.
A neutral trianionic pincer [NCN]CrIV–Me complex as a highly active ethylene polymerization precatalyst

Abstract Trianionic pincer ligands are a new class of ligands that constrain three anionic metal–ligand bonds to the meridional plane and are capable of supporting highly reactive metal species exploitable for alkene polymerization. The previously reported NCN3- trianionic pincer CrIV–Me complex [2,6-iPrNCN]CrIV(Me)THF (1), upon activation by triisobutylaluminum (TIBA), catalyzes the polymerization of ethylene. Complex 1 (1 μmol) in the presence of 35 equiv. of TIBA polymerizes ethylene with an activity of 7.02 × 106 g PE(molCr)−1 h−1 (75 °C).
OGTT‐derived Measures of Insulin Sensitivity Are Confounded by Factors Other Than Insulin Sensitivity Itself

Insulin resistance is an important risk factor for diabetes and other diseases. It has been important to estimate insulin resistance in epidemiological and genetic studies involving significant number of individuals. Complex and invasive protocols are impractical. Therefore, insulin sensitivity indices based on the oral glucose-tolerance test (OGTT) have been introduced. The aim of the present study was to assess the accuracy with which OGTT-derived indices would reflect changes in insulin sensitivity in the face of changes in other factors, such as rate of glucose absorption and/or B-cell function. A computer model was employed to predict excursions of plasma glucose and insulin after a 75-g oral glucose load. The model was then used to predict changes in these excursions, which would be observed with altered insulin resistance, with alterations in beta-cell sensitivity to glucose and/or alterations in glucose absorption rates. Published indices of insulin sensitivity could then be calculated from the predicted curves, to ask whether changes in beta-cell function or glucose absorptions rates might be misinterpreted (using the indices) as changes in insulin sensitivity. The model accurately represented OGTT data for a normal glucose tolerant subject, closely matching published data. Imposed 50% reductions or increases in insulin sensitivity alone in the model were reflected in only small changes in OGTT-derived insulin sensitivity values. More important, imposed alterations in beta-cell sensitivity and glucose absorption without simulated changes in insulin sensitivity did change insulin sensitivity indices. These results indicate that caution is required for the interpretation of differences in OGTT-derived values of insulin sensitivity, because variation in factors other than insulin sensitivity per se appear to have the greatest effects on indices calculated from the OGTT alone.
Seroprevalence of antibodies against Neospora caninum in diagnostic equine serum samples and their possible association with fetal loss.

Abstract A case–control study of the association between the presence of serum antibodies against Neospora spp. and fetal loss was performed on serum samples submitted to a veterinary diagnostic laboratory in northwestern United States. Control sera were randomly selected from those submitted from healthy horses for routine equine infectious anemia testing required for regulatory health certification. Case sera were randomly selected from those submitted from aborting mares for diagnostic workup. Based on a 1:50 or greater titer on the indirect fluorescent antibody test, 8% of the 160 control sera and 13% of the 140 case sera were titer positive. The association odds ratio of 1.67 fell short of statistical significance ( p =0.124).
Collisional excitation and alignment of np5(n+1)s2 autoionizing states of the alkali-metal atoms.

The excitation cross sections and the alignment of the lowest autoionizing states, np/sup 5/(n+1)s/sup 2/, of Na, K, Rb, and Cs, induced by impact of various projectiles, have been calculated. The alignment by projectiles heavier than electrons is seen to exhibit a rich structure as a function of impact energy and it is anticipated that its overall behavior should be observable by experiment. Good agreement is found with the available data on sodium.
AUTOMATIC-CONTROL-SYSTEM DESIGN FOR THE BERKELEY 88-INCH CYCLOTRON

Abstract The automatic-control requirements of the 88-inch cyclotron at the Lawrence Radiation Laboratory are analogous to the requirements of many process controls in industry. The system being designed will reduce setup time from twenty to five minutes and will be capable of being overridden manually. Although the system is primarily analog, the input is on punched tape or IBM cards in order to make it compatible with eventual beam optimization when digital-computer techniques will be used.
Fracture Toughness of Amorphous Metals and Composites

The effects of changes in notch radius on the toughness of two different Zr-based bulk metallic glasses have been determined. It is shown that increases in notch radius produce large increases to the toughness, accompanied by extensive shear banding and crack bifurcation. The fracture toughness of twenty (20) fatigue precracked specimens exhibiting planar crack growth were in the range 20.3 ± 6.7 MPa√m for the two Zr-based glasses. Increasing the notch radius to 110 μm produced notch toughness in the range 95.3 ± 8.3 MPa√m for nine (9) tests on Vitreloy I, well in excess of that typically observed in most structural materials. Toughness tests conducted on two fatigue precracked specimens of Vitreloy I at 77 K produced values for fracture toughness that were in the range 17.9 ± 2.7 MPa√m, similar to that obtained at 298 K. The fatigue precracked fracture toughness of metallic glass composites containing large crystalline regions of a body centered cubic Zr-Ti-Nb alloy were in the range 29–42 MPa√m, but the values were temperature dependent over the range 148 K to 500 K. Fracture surfaces were analyzed via Scanning Electron Microscopy (SEM).
A knowledge-based architecture for implementing military geographical intelligence system on Intranet

Abstract Military geographical intelligence analysis in support of both tactical and strategic operation is a process that is associated with data gathering, processing, analyzing, and distribution. It is an important activity, carried out before the preparation of a military operation. A system that can assist in arranging support, exercise analysis training, and manage knowledge on military geographical intelligence have always been ultimate goals for both military intelligence units and intelligence officers alike. Therefore, it can be seen that research into the military geographical intelligence system is a critical and important research subject. This research investigates military geographical intelligence systems as a problem-solving procedure in terms of observing the military geographical intelligence operational procedure, generating situation analysis, and generating planning process. This paper intends to present a knowledge-based architecture that incorporates the function of case base, heuristic base, and rule base for implementing the military geographical intelligence system on Intranet.
Direct observation of intramolecular energy transfer from a β-diketonate to terbium (III) ion encapsulated in a cryptand

Abstract The kinetics and pathway for the energy transfer from acetylacetonate (acac) to Tb3+ encapsulated in the macrocyclic cage of a cryptand in aqueous solution is established by time-resolved picosecond laser spectroscopy. The direct energy transfer from the 3ππ* state of acac to the Tb3+ ion has been confirmed by monitoring the luminescence decay of acac and the concomitant appearance of Tb3+ luminescence at 546 nm. An intramolecular energy transfer rate of 9.7×109s−1 is observed.
A salivary gland-specific, maltase-like gene of the vector mosquito, Aedes aegypti.

Abstract Genomic and cDNA clones of a gene expressed specifically in the salivary glands of adult Aedes aegypti have been isolated and sequenced. This gene encodes an abundant mRNA that is transcribed throughout the male salivary gland but only in the cells of the proximal lateral lobes of the female gland. The deduced protein has many basic amino acids, several possible sites for N -glycosylation, and displays striking similarities with the products of a yeast maltase gene and three previously unidentified genes from Drosophila melanogaster . We propose the name ‘Maltase-like I’ ( MalI ) to designate this gene. The presumed function of this gene product is to assist the mosquito in its sugar-feeding capabilities. The mosquito and fruitfly genes have similar structural features 5' to the protein coding regions, indicating that these genes may share common control mechanisms.
Delayed ophthalmoplegia following head trauma

Abstract An eleven-year-old boy presented to the emergency room following frontal head trauma with injury to the right optic nerve. Two weeks later he developed progressive right ophthalmoplegia. The patient's ophthalmoplegia resolved following an operation. The differential diagnosis of this entity is discussed in detail.
Sex, Drugs, and Heavy Metal: Transnational Threats and National Vulnerabilities

Technological innovations over the past fifty years have had a profound and varied impact on the security of people worldwide. As this impact increases, weaknesses in conventional security thinking and behavior become apparent. Traditional understandings of security remain relevant in the post Cold War era, and policy-makers must continue to monitor and respond to threats posed by regional powers and rogue states.ii But today we must broaden our perspective to encompass neglected areas in which new threats are intensifying, vulnerabilities are real, and forward-looking policies are required.Many contemporary threats -- such as infectious disease, terrorism, and drug trafficking -- are transnational: they cross state borders but generally cannot be linked directly to the foreign policies or behavior of other states. Rather than being created and controlled by national governments, these threats are situated in a complex, dynamic, and global web created by modern communication, transportation, and information technologies. This web offers a vast array of incentives, opportunities, and capabilities to individuals and groups whose activities, intentionally or not, can threaten the core values of national security: territorial integrity and political independence; preservation of the well being, freedom, and property of citizens; and national culture.Transnational threats are difficult to neutralize. A terrorist may be trained in Libya, receive funds from a religious sect in the United States via a Caribbean bank, purchase weapons from a Russian crime organization, travel on a Canadian passport, and attack British tourists in Germany. Sever one of the links in this chain and he or she will quickly find a replacement. Even if governments in all the relevant countries can be persuaded to intervene, they may not be able to control the fluid criminal elements and black markets at work in their own jurisdictions. The transnational character of these actors and phenomena make them relatively impervious to traditional state-centric means of enforcement. Only by a concerted effort, involving the support of non-state actors from weapons manufacturers to commercial banks, can one hope to disrupt the transnational web of incentives, opportunities, and capabilities enough to discourage terrorism. A similar logic holds for many other transnational problems.In the following pages we discuss the increasing vulnerability of states to transnational threats and the sort of response strategies that might be effective. As numerous historians have made clear, how societies fare is closely linked to their ability to adapt to the diffusion of technology, the spread of disease, and environmental change. The failure to recognize and respond to the negative aspect of these changes in the past might explain why much of humankind lives in despair today. If, as we believe, the rate and magnitude of these transnational forces have grown, our understanding of them has improved, and the stakes are higher than ever, then much may depend on how well we respond to them today.
FROM TRAINING TO TESTING: DETAILS OF AN AGGRESSIVE DRILL AND EXERCISE PROGRAM

ABSTRACT With 1997 comes a second triennial period of exercises following the implementation of the Oil Pollution Act of 1990 (OPA 90). Exercises should now be performed in more of a testing environment than in a training environment. Aggressive exercises seek to test response plans and spill management teams rather than to provide opportunities for training. Aggressive exercises also require that one learn by taking risks and making mistakes. Consequently, for this aggressive style of drills and exercises to succeed, regulatory authorities must acknowledge risk taking when they are evaluating exercises. Though training will always be a focus, at least in some elements of response exercises, it should become more specific and compartmentalized while the remaining bulk of the response is being tested. Because aggressive exercises require full agency representation, joint exercises should be considered a way of reducing the number of industry-led drills while achieving credit for multiple plan holders.
COMPUTATION OF MAXIMUM LIKELIHOOD ESTIMATES OF GRAVITY MODEL PARAMETERS

. This paper presents the derivations of several new algorithms for the computation of maximum likelihood estimates of the parameters of a very general form of the gravity model. The algorithms are then compared with previously available algorithms including GLIM and that given in Sen (1986). One of the new algorithms emerges as far superior in just about every way to its competitors. In particular, it is usually much more than an order of magnitude faster than the GLIM procedure and that given in Sen (1986). It is also not substantially affected by pitfalls such as multicollinearity and (unlike the GLIM procedure) is capable of comfortably handling large O-D matrices.
The Biologic Clock: The Mitochondria?

: The author suggests that the maximal life span of a given mammalian species is largely an expression of genetic control over the rate of oxygen utilization. The latter determines the rate of accumulation of mitochondrial damage produced by free radical reactions, the rate increasing with the rate of oxygen consumption, which ultimately causes death.
Close-Coupling Calculations of Spin-Polarized Hydrogen-Deuterium Collisions

Close-coupling calculations on the atomic collisions at cryogenic energies in a 100-kG magnetic field between spin-polarized hydrogen (H\ensuremath{\uparrow}) and deuterium (D\ensuremath{\uparrow}) have demonstrated the resonant spin-flip process postulated by Stwalley and the importance of minimizing the presence of D\ensuremath{\uparrow} in the experimental preparations of bulk H\ensuremath{\uparrow} currently in progress. Other interesting features are presented and briefly discussed including multiple Ramsauer-Townsend effects and direct electron and nuclear single- and double-spin-flip processes.
Operation of General Purpose Stepping Motor Controllers at the National Synchrotron Light Source

A prototype and four copies of a general purpose subsystem for mechanical positioning of detectors, samples, and beam line optical elements which constitute experiments at the National Synchrotron Light Source facility of Brookhaven National Laboratory have been constructed and placed into operation. Construction of a sixth subsystem is nearing completion. The subsystems effect mechanical positioning by controlling a set of stepping motors and their associated position encoders. The units are general purpose in the sense that they receive commands over a standard 9600 baud asynchronous serial line compatible with the RS-232-C electrical signal standard, generate TTL-compatible streams of stepping pulses which can be used with a wide variety of stepping motors, and read back position values from a number of different types and models of position encoder. The basic structure of the motor controller subsystem will be briefly reviewed. Short descriptions of the positioning apparatus actuated at each of the test and experiment stations employing a motor control unit are given. Additions and enhancements to the subsystem made in response to problems indicated by actual operation of the four installed units are described in more detail.
The approximability of NP-hard problems

Many problems in combinatorial optimization are NP-hard (see [60]). This has forced researchers to explore techniques for dealing with NP-completeness. Some have considered algorithms that solve “typical” or “average” instances instead of worst-case instances [86, 100]. In practice, however, identifying “typical” instances is not easy. Other researchers have tried to design approximation algorithms. An algorithm achieves an approximation ratio α for a maximization problem if, for every instance, it produces a solution of value at least OPT/α, where OPT is the value of the optimal solution. (For a minimization problem, achieving a ratio α involves finding a solution of cost at most αOPT .) Note that the approximation ratio is ≥ 1 by definition. After twenty-five years of research, approximation algorithms is a major research area with deep techniques (see [75] for a detailed survey). Nevertheless, researchers have failed to design good approximation algorithms for a wide variety of NPhard optimization problems. Recent developments in complexity theory —specifically, in the area of probabilistically checkable proofs or PCPs— suggest a reason for this failure: for many NP-hard problems, including MAX-CLIQUE, CHROMATIC NUMBER, MAX-3SAT, and SET-COVER, achieving certain reasonable approximation ratios is no easier than computing optimal solutions. In other words, approximation is NP-hard. These negative
Institutional Power: Identity, Politics, and Lived Experiences in the Dance License via Portfolio Process

In this research study, I examined how institutional power affected the experiences of two dance educators attempting to gain their K–12 dance teaching license in Minnesota. My research analyzed the ways in which candidates applying for the portfolio review process constructed, amended, or abandoned their identities as teachers/artists/individuals while completing the process. Using critical discourse analysis to examine interview data collected in the study, I sought to better understand how institutional power disrupted the experiences of candidates completing their license via portfolio. My results suggest that participants in the study delegitimized their teaching experience outside of the K–12 context, which challenged their teaching identities and left them feeling powerless during the license via portfolio process. Confusing, inconsistent, and incorrect information provided by the Minnesota Department of Education combined with a lack of support from the state also contributed to their feelings of ...
Models for MIMD Machines

This paper describes two simple models for estimating the processing times of algorithms run on MIMD (Multiple Instruction Multiple Data) machines. The first model is developed from very elementary queueing concepts. The second uses the critical path through a PERT-diagram-arrangement of the algorithm's tasks. The models require far less effort than either benchmarking or detailed simulations. We envision them being used in all but the very final stages of the search for, and design of, good combinations of algorithms and MIMD machines.
Fabrication and characterization of joined silicon carbide cylindrical components for nuclear applications

Abstract The use of silicon carbide (SiC) composites as structural materials in nuclear applications necessitates the development of a viable joining method. One critical application for nuclear-grade joining is the sealing of fuel within a cylindrical cladding. This paper demonstrates cylindrical joint feasibility using a low activation nuclear-grade joint material comprised entirely of β-SiC. While many papers have considered joining material, this paper takes into consideration the joint geometry and component form factor, as well as the material performance. Work focused specifically on characterizing the strength and permeability performance of joints between cylindrical SiC–SiC composites and monolithic SiC endplugs. The effects of environment and neutron irradiation were not evaluated in this study. Joint test specimens of different geometries were evaluated in their as-fabricated state, as well as after being subjected to thermal cycling and partial mechanical loading. A butted scarf geometry supplied the best combination of high strength and low permeability. A leak rate performance of 2 × 10 −9 mbar l s −1 was maintained after thermal cycling and partial mechanical loading and sustained applied force of 3.4 kN, or an apparent strength of 77 MPa. This work shows that a cylindrical SiC–SiC composite tube sealed with a butted scarf endplug provides out-of-pile strength and permeability performance that meets light water reactor design requirements.
Transitivity of fuzzy relations and rational choice

An attempt is made to explore the implications of weakening the transitivity condition used in defining a fuzzy preference ordering for various results established in the literature.
A monte carlo study on two methods of calculating the mle's covariance matrix in a seemingly unrelated nonlinear regression. *

Econometric techniques to estimate output supply systems, factor demand systems and consumer demand systems have often required estimating a nonlinear system of equations that have an additive error structure when written in reduced form. To calculate the ML estimate's covariance matrix of this nonlinear system one can either invert the Hessian of the concentrated log likelihood function, or invert the matrix calculated by pre-multiplying and post multiplying the inverted MLE of the disturbance covariance matrix by the Jacobian of the reduced form model. Malinvaud has shown that the latter of these methods is the actual limiting distribution's covariance matrix, while Barnett has shown that the former is only an approximation. In this paper, we use a Monte Carlo simulation study to determine how these two covariance matrices differ with respect to the nonlinearity of the model, the number of observations in the dataet, and the residual process. We find that the covariance matrix calculated from the Hessia...
The centered lateral fluoroscopic image of the knee: The key to safe tensioned wire placement in periarticular fractures of the proximal tibia

The importance of using the centered lateral view of the knee for placement of tensioned wires during the treatment of periarticular fractures of the proximal tibia is illustrated. The technique of using a horizontal reference wire as a landmark for subsequent wire placement is described for circular fixators and hybrid fixators.
A System, Society, and Community Perspective on Genocide

The question of why the international community continually fails to prevent genocide remains an ever-present concern. Genocide scholars question how the political will of the politically unwilling remains unaltered by the genocides in Rwanda and Darfur. However, it appears that little consideration has been given to the fact that genocide is open to interpretation. By this I mean that all scholars and policy makers have a view of the world which shapes their understanding of genocide within it. This is important because it helps explain why actors at the international level perceive genocide prevention in a radically different light from one another. With this in mind, the article uses the concepts of an international system, an international society, and an international community to demonstrate how one’s worldview has implications on how one understands genocide. These three perspectives help underline the complexities involved as genocide prevention remains dependent on a consensus being forged among ...
Maximum Entropy Principle with General Deviation Measures

An approach to the Shannon and Renyi entropy maximization problems with constraints on the mean and law-invariant deviation measure for a random variable has been developed. The approach is based on the representation of law-invariant deviation measures through corresponding convex compact sets of nonnegative concave functions. A solution to the problem has been shown to have an alpha-concave distribution (log-concave for Shannon entropy), for which in the case of comonotone deviation measures, an explicit formula has been obtained. As an illustration, the problem has been solved for several deviation measures, including mean absolute deviation (MAD), conditional value-at-risk (CVaR) deviation, and mixed CVaR-deviation. Also, it has been shown that the maximum entropy principle establishes a one-to-one correspondence between the class of alpha-concave distributions and the class of comonotone deviation measures. This fact has been used to solve the inverse problem of finding a corresponding comonotone deviation measure for a given alpha-concave distribution.
Factors influencing human visitation of southern California rocky intertidal ecosystems

Abstract In highly urbanized regions, rocky intertidal habitats attract a large number of visitors for recreation, education, and subsistence harvesting. The collecting, trampling, and handling activities of visitors can have detrimental impacts on intertidal flora and fauna, including reduced abundances and biodiversity and alteration of community structure and function. Despite the large human population in southern California, USA, the level of visitor use at accessible rocky intertidal locations can vary greatly. The goal of this study was to investigate a suite of factors that may influence the number of visitors a site receives. Thirty-two rocky intertidal sites interspersed along ∼175 km of shoreline between Los Angeles and San Diego County in southern California were established and the relative visitor use intensity determined during four aerial surveys conducted during low tide periods. Site-specific characteristic, including cost and availability of parking, physical exertion in reaching a site, popularity of site for educational field trips, density of local human population, and the presence of local attractions, were examined and related to relative use intensity. Popularity of a site for educational field trips was the most significant driver, followed by physical exertion and presence of non-tidepooling attractions. Results from this study may be used as a potential management tool to reduce use and protect anthropogenically-disturbed rocky shores by, for example, regulating educational field trips and manipulating attributes that could alter the degree of physical exertion needed to reach a site.
Geometrical Frustration and Glass Formation

The effect of geometrical frustration in the atomic structure on the formability of bulk metallic glasses is discussed from a general point of view. It is pointed out that there are two distinct and complementing pathways to easy glass formation: stabilizing the glass itself and destabilizing the corresponding crystalline state. While the discussions in the field tend to focus on the first one, the second in fact is a more effective approach. Examples of both will be discussed using soft-sphere, rather than hard-sphere, packing concepts.
Implementation Outcomes of Multidimensional Family Therapy–Detention to Community: A Reintegration Program for Drug-Using Juvenile Detainees

Responding to urgent calls for effective interventions to address young offenders' multiple and interconnected problems, a new variant of an existing empirically-validated intervention for drug-using adolescents, Multidimensional Family Therapy (MDFT)-Detention to Community (DTC) was tested in a two-site controlled trial. This article (a) outlines the rationale and protocol basics of the MDFT-DTC intervention, a program for substance-using juvenile offenders that links justice and substance abuse treatment systems to facilitate adolescents' post-detention community reintegration; (b) presents implementation outcomes, including fidelity, treatment engagement and retention rates, amount of services received, treatment satisfaction, and substance abuse-juvenile justice system collaboration outcomes; and (c) details the implementation and sustainability challenges in a cross-system (substance abuse treatment and juvenile justice) adolescent intervention. Findings support the effectiveness of the MDFT-DTC intervention, and the need to develop a full implementation model in which transfer and dissemination issues could be explored more fully, and tested experimentally.
Algorithms for Fault-Tolerant Topology in Heterogeneous Wireless Sensor Networks

This paper addresses fault-tolerant topology control in a heterogeneous wireless sensor network consisting of several resource-rich supernodes, used for data relaying, and a large number of energy-constrained wireless sensor nodes. We introduce the k-degree anycast topology control (fc-ATC) problem, with the objective of selecting each sensor's transmission range such that each sensor is k-vertex supernode connected and the total power consumed by sensors is minimized. Such topologies are needed for applications that support sensor data reporting, even in the event of failures of up to k - 1 sensor nodes. We propose three solutions for the k-ATC problem: a k-approximation algorithm, a greedy centralized algorithm that minimizes the maximum transmission range between all sensors, and a distributed and localized algorithm that incrementally adjusts sensors' transmission range such that the k-vertex supernode connectivity requirement is met. Extended simulation results are presented to verify our approaches.
Expressing and verifying probabilistic assertions

Traditional assertions express correctness properties that must hold on every program execution. However, many applications have probabilistic outcomes and consequently their correctness properties are also probabilistic (e.g., they identify faces in images, consume sensor data, or run on unreliable hardware). Traditional assertions do not capture these correctness properties. This paper proposes that programmers express probabilistic correctness properties with probabilistic assertions and describes a new probabilistic evaluation approach to efficiently verify these assertions. Probabilistic assertions are Boolean expressions that express the probability that a property will be true in a given execution rather than asserting that the property must always be true. Given either specific inputs or distributions on the input space, probabilistic evaluation verifies probabilistic assertions by first performing distribution extraction to represent the program as a Bayesian network. Probabilistic evaluation then uses statistical properties to simplify this representation to efficiently compute assertion probabilities directly or with sampling. Our approach is a mix of both static and dynamic analysis: distribution extraction statically builds and optimizes the Bayesian network representation and sampling dynamically interprets this representation. We implement our approach in a tool called Mayhap for C and C++ programs. We evaluate expressiveness, correctness, and performance of Mayhap on programs that use sensors, perform approximate computation, and obfuscate data for privacy. Our case studies demonstrate that probabilistic assertions describe useful correctness properties and that Mayhap efficiently verifies them.
Positive uncertain systems with one-sided robust control

We consider a control design problem for a class of uncertain systems. The salient features of the problem are fourfold. First, the uncertainty is time-varying. Second, the system is nonlinear. Third, the state is constrained to be only positive. Fourth, the control input may be constrained to be one-sided (i.e., either positive or negative). We start with a state transformation to release the state constraint. A partial sign-definiteness knowledge of the uncertainty is then shown to be critical to meet the control constraint. Three classes of controls are constructed: one for state constraint and two for the additional control constraint. They render the system globally practically stable.
Intracranial EEG analysis in tumor-related epilepsy: Evidence of distant epileptic abnormalities.

Abstract Objective In patients with tumor-related epilepsy (TRE), surgery traditionally focuses on tumor resection; but identification and removal of associated epileptogenic zone may improve seizure outcome. Here, we study spatial relationship of tumor and seizure onset and early spread zone (SOSz). We also perform quantitative analysis of interictal epileptiform activities in patients with both TRE and non-lesional epilepsy in order to better understand the electrophysiological basis of epileptogenesis. Methods Twenty-five patients (11 with TRE and 14 with non-lesional epilepsy) underwent staged surgery using intracranial electrodes. Tumors were outlined on MRI and images were coregistered with post-implantation CT images. For each electrode, distance to the nearest tumor margin was measured. Electrodes were categorized based on distance from tumor and involvement in seizure. Quantitative EEG analysis studying frequency, amplitude, power, duration and slope of interictal spikes was performed. Results At least part of the SOSz was located beyond 1.5 cm from the tumor margin in 10/11 patients. Interictally, spike frequency and power were higher in the SOSz and spikes near tumor were smaller and less sharp. Interestingly, peritumoral electrodes had the highest spike frequencies and sharpest spikes, indicating greatest degree of epileptic synchrony. A complete resection of the SOSz resulted in excellent seizure outcome. Conclusions Seizure onset and early spread often involves brain areas distant from the tumor. Significance Utilization of epilepsy surgery approach for TRE may provide better seizure outcome and study of the intracranial EEG may provide insight into pathophysiology of TRE.