cssi/SciSciGPT-SciSciNet huggingface dataset:
The r-Process in the Early Galaxy

We report Sr, Pd, and Ag abundances for a sample of metal-poor field giants and analyze a larger sample of Y, Zr, and Ba abundances. The [Y/Zr] and [Pd/Ag] abundance ratios are similar to those measured for the r-process-rich stars CS 22892-052 and CS 31082-001. The [Pd/Ag] ratio is larger than predicted from the solar system r-process abundances. The constant [Y/Zr] and [Sr/Y] values in the field stars place strong limits on the contributions of the weak s-process and the main s-process to the light neutron-capture elements. Stars in the globular cluster M15 possess lower [Y/Zr] values than the field stars. There is a large dispersion in [Y/Ba]. Because the r-process is responsible for the production of the heavy elements in the early Galaxy, these dispersions require varying light-to-heavy ratios in r-process yields.
Surface-Functionalized CdSe Nanorods for Assembly in Diblock Copolymer Templates

Poly(ethylene oxide)-covered CdSe nanorods were prepared and assembled in diblock copolymer templates by floating the block copolymer templates onto aqueous nanorod solutions. The assembly was enabled by consideration of the surface ligand coverage of the nanorods. Alkane-covered CdSe nanorods prepared by state-of-the-art techniques are not compatible with this assembly process. However, poly(ethylene oxide) (PEO)-functionalized CdSe nanorods were successfully used to assemble the nanorods into the channels and pores of diblock copolymer templates. Other water-dispersible CdSe nanorods, such as those covered with 11-mercaptoundecanoic acid (MUA), did not give the desired assemblies. These results are understood by considering the surface energies of the PEO-covered CdSe nanorods in this interfacial assembly process.
The Science Case for STEP

Abstract The Satellite Test of the Equivalence Principle (STEP) will advance experimental limits on violations of Einstein’s Equivalence Principle (EP) from their present sensitivity of 2 parts in 10 13 to 1 part in 10 18 through multiple comparison of the motions of four pairs of test masses of different compositions in an earth-orbiting drag-free satellite. Dimensional arguments suggest that violations, if they exist, should be found in this range, and they are also suggested by leading attempts at unified theories of fundamental interactions (e.g., string theory) and cosmological theories involving dynamical dark energy. Discovery of a violation would constitute the discovery of a new force of nature and provide a critical signpost toward unification. A null result would be just as profound, because it would close off any possibility of a natural-strength coupling between standard-model fields and the new light degrees of freedom that such theories generically predict (e.g., dilatons, moduli, quintessence). STEP should thus be seen as the intermediate-scale component of an integrated strategy for fundamental physics experiments that already includes particle accelerators (at the smallest scales) and supernova probes (at the largest). The former may find indirect evidence for new fields via their missing-energy signatures, and the latter may produce direct evidence through changes in cosmological equation of state—but only a gravitational experiment like STEP can go further and reveal how or whether such a field couples to the rest of the standard model. It is at once complementary to the other two kinds of tests, and a uniquely powerful probe of fundamental physics in its own right.
Clathrin heavy chain is required for TNF-induced inflammatory signaling.

Background Tumor necrosis factor receptor I recruits tumor necrosis factor receptor-associated death domain (TRADD) and multiple kinases that ultimately phosphorylate inhibitor kappa B (IKBα). Degradation of phospho-IKBα (p-IKBα) frees nuclear factor kappa B (NFKB) to be active and phosphorylated. Many receptors require clathrin-mediated endocytosis to provide the scaffolds necessary for signaling. Therefore, we investigated the role of clathrin heavy chain (CHC) in tumor necrosis factor α (TNF-α)–induced IKBα phosphorylation and NFKB activation. We hypothesized that CHC was required for TNF-α–induced inflammatory signaling. Methods We treated human pulmonary epithelial cells with small interfering RNA to knock down intracellular CHC (CHCsil). TRADD and scrambled (noncoding) small interfering RNA sequences were used as positive and negative controls, respectively. Treatment groups were exposed to 10 ng/mL of TNF-α. Total IκBα, p-IκBα, and phosphorylated P65 (a subunit of NFKB) were determined by immunoblot staining. Densitometry was normalized to controls for the analysis of the stains. TNF-α–induced release of monocyte chemoattractant protein 1 (MCP-1) was determined by enzyme-linked immunosorbent assay. Statistical analyses were determined by analysis of variance or paired t test as appropriate. Results TNF-α−induced IκBα phosphorylation and degradation at 5 and 30 minutes, respectively, and induced P65 phosphorylation. CHCsil diminished p-IκBα by 91% (P Conclusions CHCsil significantly impairs phosphorylation of both IκBα and P65. CHCsil also significantly decreased MCP-1 production. These data suggest that CHC is required for certain TNF-α–induced, inflammatory signaling pathways.
A possible solution to the tritium endpoint problem

Abstract Scalar or right-chiral interaction currents may be expected to produce a neutrino coupled to the electron which is different from, and perhaps even orthogonal to, that coupled to the electron by the standard model weak interaction. We show that, using reasonable parameter values for such additional interactions, it is possible to generate a spectrum which, if analyzed in the manner commonly employed by experimental groups, produces a negative neutrino mass-squared.
Reactions of TCNE with isomeric 2,4-hexadienes

Abstract The reactivities of the isomeric 2,4-hexadienes with tetracyanocthylene (TCNE) differ enormously, in the order E,E ⪢ E,Z ⪢ Z,Z . The inertness of the Z,Z isomer allows complete removal of the other isomers by formation of adducts.
From the Peaks to the Valleys: Cross-State Evidence on Income Volatility over the Business Cycle

Abstract Countercyclical variation in individuals' idiosyncratic labor income risk could generate substantial welfare costs. Following past research, we infer income volatility—the variance of permanent income shocks, a standard proxy for income risk—from the rate at which cross-sectional variances of income rise over the life cycle for a given cohort. Our novelty lies in exploiting cross-state variation in state economic conditions or state sensitivity to national economic conditions. We find that income volatility is higher in good state times than bad; during good national times, we find volatility is higher in states that are more sensitive to national conditions.
Effect of Nonaxisymmetric Forcing on a Swirling Jet With Vortex Breakdown

The helical mode instability (which is related to the centrifugal instability) may be a key aspect of the enhanced mixing and entrainment mechanism in strongly swirling jets. The purpose of the present investigation is to excite the helical mode instability of the vortex breakdown flow field. It is expected that this excitation may affect the development of the flow field and enhance the mixing and entrainment. Nonaxisymmetric forcing was applied to the breakdown flow field of a strongly swirling jet. This led to excitation of the helical mode at any desired frequency. Effects of forcing on the flow field were investigated.
Selected risk and protective factors associated with two or more lifetime sexual intercourse partners and non-condom use during last coitus among U.S rural high school students

Abstract This analysis determined the association between 13 selected health risk and protective factors and reporting two or more lifetime sexual intercourse partners and non-condom use for last coitus among sexually experienced U.S. rural high school students. The sample was 569 sexually experienced adolescent females and 561 sexually experienced adolescent males who participated in the national 1999 Youth Risk Behavior Survey and who attended rural high schools. For females, coital debut before age 15, forced sexual intercourse, physical abuse, and marijuana use were associated with having two or more lifetime sexual intercourse partners. Coital debut before 15, binge drinking, and marijuana use were associated with having two or more sexual intercourse partners for males. Coital debut before age 15, forced sexual intercourse, and regular cigarette smoking were associated with non-condom use at last coital episode for females. Forced sexual intercourse and cocaine use were associated with non-condom us...
Modeling of Processing for Slot and Discrete Port Tapered Resin Injection Pultrusion

Pultrusion is a very cost-effective method for manufacturing structural components of constant cross sections for aerospace applications and for a broad range of other engineering applications. The quality and mechanical strength of the pultruded part depends on the wet out of the fiber reinforcement by the liquid resin; the strength and, thus, the quality of the composite are superior when the fiber reinforcement is fully impregnated (complete wet out) with liquid resin. This work explores the wet-out characteristics in the injection pultrusion process. Complete wet out of the dry fiber matrix with liquid resin depends significantly on the processing parameters. The process parameters, fiber pull speed, fiber volume fraction, and resin viscosity are explored in this study. The finite volume technique is employed to simulate the flow of polyester resin through the fiber matrix (glass rovings), and the impact of the process parameters on the injection pressure required to achieve complete fiber wet out is investigated. The location of the liquid resin flow front is predicted for the discrete port injection and the slot injection configurations. The results show the impact of the tapering of the injection chamber walls on the minimum injection pressure required to achieve complete fiber wet out and the corresponding resin pressure at the injection chamber exit. A small taper on the walls of the injection chamber was found to have a significant impact on the minimum injection pressure necessary to achieve complete fiber matrix wet out.
U(1) gauge invariance from open string field theory

The naive low energy effective action of the tachyon and the U(1) gauge field obtained from string field theory does not correspond to the world volume action of unstable branes in bosonic string theory. We show that there exists a field redefinition which relates the gauge field and the tachyon of the string field theory action to the fields in the world volume action of unstable branes. We identify a string gauge symmetry which corresponds to the U(1) gauge transformation. This is done to the first non linear order in the fields. We examine the vector fluctuations at the tachyon condensate till level (4,8).
Breakfast Cereals: The Extreme Food Industry

By nearly all indicators employed by industrial-organization economists to measure market structure, company conduct, and social performance, the ready-to-eat cereals industry ranks at the extreme end of the range of food industries. As the quintessential shared monopoly, renewed attention by the antitrust agencies might yield economic benefits for consumers. [EconLit cites: L100, L410, L660] © 1999 John Wiley & Sons, Inc.
Simulating the effect of nepotism on political risk taking and social unrest

Nepotism has been the primary influence on political behavior throughout human history. Despite the spread of democracy in the 20th century, nepotistic regimes have hardly disappeared. Nepotism heavily influences political activity throughout the developing world, Middle East, and central Asia where family ties are essential for gaining access to power, state resources, and privileges. Rebelling against such nepotistic regimes is difficult and risky. RiskTaker is an agent-based model we developed for testing the influences of various social forces on risk taking behavior, including the formulation of rebellious coalitions. We use RiskTaker to examine the influence of nepotism on the distribution of wealth and social status. Nepotism heavily skews the distribution of wealth and status, leading to the formation of opposing coalitions and exacerbating social unrest.
Effects of Crossflow Temperature on Heat Transfer Within an Array of Impinging Jets

Two-dimensional arrays of circular air jets impinging on a heat transfer surface parallel to the jet orifice plate are considered. In the experimental model the jet flow, after impingement, was constrained to exit in a single direction along the channel formed by the jet orifice plate and heat transfer surface. In addition to the crossflow that originated from the jets following impingement, an initial crossflow was present that approached the array through an upstream extension of the channel. By varying the initial crossflow temperature, the mixed-mean crossflow temperature approching each spanwise jet row n (Tm,n ) was varied independently of the jet temperature (Tj ). For each row, the effect of Tm,n relative to Tj on the heat flux opposite the row was determined. Results are formulated in terms of parameters defined for each individual spanwise row domain: a crossflow-to-jet temperature difference influence factor (ηr ) and a Nusselt number (Nur ) as functions of jet Reynolds number, crossflow-to-jet mass flux ratio, and geometric parameters. Effects of row position within the array are also considered. It was found that ηr and Nur are nominally independent of row position after the first two rows.
Why Store Genetic Stocks

National Seed Storage Laboratory Crops Research Division ARS, USDA Fort Collins, Colorado One of the functions of the National Seed Storage Laboratory is the preservation of genetic stocks. The 52,000 accessions now in storage include only 932 lots of seed which fall into this category. These are: 310 barley lines, 112 tomato mutants, 110 red pericarp lines of corn, and 400 radiation-induced mutants of oats. In the near future we should receive for storage 150 translocation stocks of barley. These total only a small fraction of such materials held at various locations throughout the country. The conditions under which the genetic stocks are stored at various institutions may or may not be favorable for prolonged preservation. Where poor storage conditions exist, there is a definite possibility that much valuable material will lose viability. The well documented Datura collection of A. F. Blakeslee of Smith College in Massachusetts is a striking example. This collection was transferred in 1966 to the National Seed Storage Laboratory. Sixty-nine lines were discarded due to lack of viability. An additional 243 lines require immediate reincrease because they have very low germination percentages or because the quantities are so small that future distribution would be extremely limited. Fortunately, a number of people are interested in this collection and a reincrease program is proposed for the summer of 1967. After the collection is brought up to satisfactory standards, it will be officially accepted by the National Seed Storage Laboratory, which will then have the responsibility for maintenance. We have recently been advised of the possible disposal of an Oenothera collection of historical as well as current interest to geneticists. Most of the seeds will probably be deposited in the National Seed Storage Laboratory rather than distributed to various individuals interested in the species. This will become a central source of supply from which researchers may obtain seeds, and those interested in a few specific genetic characters will not have to maintain their own seed stocks. Since the establishment of the National Seed Storage Laboratory, we have given priority to seeds of economic importance. Collections of this type are now limited to varieties currently being released by Federal and State experiment stations and commercial firms. To be of additional service to researchers, we will include the procurement and storage of basic genetic collections. There are several advantages in storing such collections in the National Seed Storage Laboratory: 1) If research is discontinued on a specific collection, or if an individual who is primarily interested in the collection retires, it will be preserved intact and its viability maintained. 2) Seeds at the National Seed Storage Laboratory are available to all researchers and, on request, they can obtain an inventory of seed stocks on hand.
Evaluation and control of hot working environments: Part II -- The scientific basis (knowledge base) for the guide

This chapter discusses the evaluation and control of hot working environments. Heat stress and the resulting heat strain are well recognized hazards in the workplace. Although tolerance to heat stress and the risk for heat-related disorders are affected by personal factors, the population risk increases as the level of stress increases. The successful evaluation of heat stress requires a quantitative basis to make decisions about the level of heat stress present. The three most obvious responses to heat stress exposures are increases in body temperature, heart rate, and sweating. Fluid replacement is a fundamental heat stress hygiene practice. The first step to an evaluation scheme is to have a goal of controlling core temperature. There is a transition zone where body core temperature starts increasing with increasing environmental heat, which means that there is an increased risk that a worker under those conditions will be unable to maintain the thermal equilibrium. Evaluation of heat stress requires information on metabolic heat, as well as environmental heat. The methods to estimate metabolic rate include the measurement of oxygen consumption, estimation by task analysis, and estimation by activity analysis.
Amplified spontaneous emission in a single pass free electron laser

Abstract We discuss the relationship of the effective start-up noise in a single pass free electron laser to the spontaneous radiation emitted in the initial gain length of the wiggler magnet. Also, it is noted that the number of modes in the output is related to the phase space volume occupied by the spontaneous radiation emitted in the first gain length.
Does Forecast Accuracy Matter to Security Analysts

We investigate if earnings forecast accuracy matters to security analysts by examining its association with analyst turnover. Controlling for firm‐ and time‐period effects, forecast horizon and industry forecasting experience, we find that an analyst is more likely to turn over if his forecast accuracy is lower than his peers. We find no association between an analyst's probability of turnover and his absolute forecast accuracy. We also investigate another observable measure of the analyst's performance, the profitability of his stock recommendations. There is no statistical relation between the absolute or relative profitability of an analyst's stock recommendations and his probability of turnover. We interpret our findings as indicating that forecast accuracy is important to analysts.
Stimulation of goblet cell mucous secretion by activation of nerves in rat conjunctiva

An epithelial debridement wound, as a stimulus to the cornea, causes conjunctival goblet cell mucous secretion in that eye. To determine if this stimulation of secretion is neurally mediated, rats were anesthetized and the local anesthetic lidocaine (1%) or buffer alone was administered topically and/or subconjunctivally for 15 min. A corneal epithelial debridement wound was made in one eye. The contralateral eye served as the control. After 5-120 min, animals were sacrificed and inferior bulbar conjunctival buttons removed. Mucus in the goblet cells was stained with Alcian blue and periodic acid-Schiff's reagent to indicate mucin-containing goblet cells. The number of mucin-containing goblet cells/0.16 mm2 was determined by light microscopy; a decrease in number indicated an increase in mucous secretion. Stimulation by corneal wounding induced goblet cell mucous secretion in that eye. Secretion was observed as rapidly as 5 min after stimulus and for as long as 120 min. Topical application of lidocaine, subconjunctival injection of lidocaine, or a combination of both inhibited wound-induced stimulation of mucous secretion. We conclude that conjunctival goblet cell mucous secretion can be neurally mediated and could serve as an immediate response to protect the ocular surface.
Quantitative photothermal deflection spectroscopy in a flowing stream of gas.

In this paper photothermal deflection spectroscopy (PDS) is used to measure ethylene in nitrogen in a flowing stream with velocities high enough (>100 cm/sec) that forced convection dominates over thermal conduction in the heat flow. The PDS signal was found to be linear in ethylene concentration and pump laser power and varied inversely with gas velocity. It was also measured as a function of the relative position of the laser beam waists with respect to each other and with respect to the position of the tube from which the gas flowed. The energy equation for this system was solved analytically for the case of a steady-state temperature and numerically for the more general time-dependent case. The resulting calculations of signal as a function of time compare very well with experiment. This technique has the advantages of high sensitivity (1 ppm in the present conditions), good spatial resolution, and is nonintrusive.
Improved Precursor Chemistry for the Synthesis of III–V Quantum Dots

The synthesis of III–V quantum dots has been long known to be more challenging than the synthesis of other types of inorganic quantum dots. This is attributed to highly reactive group-V precursors. We synthesized molecules that are suitable for use as group-V precursors and characterized their reactivity using multiple complementary techniques. We show that the size distribution of indium arsenide quantum dots indeed improves with decreased precursor reactivity.
A new class of C-nucleoside analogues. 1-(S)-aryl-1,4-dideoxy-1,4-imino-D-ribitols, transition state analogue inhibitors of nucleoside hydrolase

Abstract The first members of a new class of N-glycohydrolase transition state analogue inhibitors, 1,4-dideoxy-1,4-imino-1-(S)-phenyl-D-ribitol, 1, and 1,4-dideoxy-1,4-imino-1-(S)-(4-imidazolyl)-D-ribitol, 2, have been synthesized. These compounds represent a new type of C-nucleoside analogue in which the endocyclic ribosyl ring oxygen has been replaced with nitrogen. The key synthetic step involves reaction of a protected ribosylimine with a metallated aryl species. The compounds are transition state analogues for enzymes which catalyzed CN glycosidic bond hydrolyses of nucleosides and have transition states with oxocarbenium ion character. Compounds 1 and 2 are potent competitive inhibitors with dissociation constants of 0.03 and 2.5 μM, for nucleoside hydrolase from the trypanosome Crithidia fasciculata. The highly effective inhibition observed demonstrates the importance of including both charge and aglycon mimicry in a glycosylase transition state analogue and differentiates it from simpler analogues.
Macroeconomic policies and participation in IMF programs

Abstract This paper poses the question whether and to what extent developing countries’ macroeconomic policies affect their participation in IMF programs. The data contain 91 developing countries that received four types of IMF programs during the period 1967–1996. Using survival analysis and generalized least squares, we examine the characteristics of interprogram years (years without any IMF program). The results suggest that the average number of years that countries spend without an IMF program is affected by their macroeconomic policies and exchange rate regimes. Policy combinations that prevent the reduction in reserves lengthen the average interprogram period.
Control of Squeezed Phonon and Spin States

In this paper, we analyze the quantum control of squeezed states of harmonic oscillators as well as spin squeezing and its relationship to quadrature squeezed states of other bosonic fields. Squeezing provides a method for reducing noise below the quantum limit and provides an example of the control of under-actuated control systems in the stochastic and quantum context. We consider also the interaction of a squeezed quantum oscillator with an external heat bath and the problem of cancellation of squeezed states. Our controls consist of single or multiple pulses.
Challenge to the Charging Model of Semiconductor-Nanocrystal Fluorescence Intermittency from Off-State Quantum Yields and Multiexciton Blinking

Semiconductor nanocrystals emit light intermittently; i.e., they “blink,” under steady illumination. The dark periods have been widely assumed to be due to photoluminescence (PL) quenching by an Auger-like process involving a single additional charge present in the nanocrystal. Our results challenge this long-standing assumption. Close examination of exciton PL intensity time traces of single CdSe(CdZnS) core (shell) nanocrystals reveals that the dark state PL quantum yield can be 10 times less than the biexciton PL quantum yield. In addition, we observe spectrally resolved multiexciton emission and find that it also blinks with an on/off ratio greater than 10:1. These results directly contradict the predictions of the charging model.
Acoustic Testing of High-Temperature Panels

Results are presented of a series of thermal-acoustic tests conducted on the NASA Langley Research Center Thermal-Acoustic Test Apparatus to (1) investigate techniques for obtaining strain measurements on metallic and carbon-carbon materials at elevated temperature; (2) document the dynamic strain response characteristics of several superalloy honeycomb thermal protection system panels at elevated temperatures of up to 1200 F; and (3) determine the strain response and sonic fatigue behavior of four carbon-carbon panels at both ambient and elevated temperatures. A second study tested four carbon-carbon panels to document panel dynamic response characteristics at ambient and elevated temperature, determine time to failure and faliure modes, and collect continuous strain data up to panel failure. Strain data are presented from both types of panels, and problems encountered in obtaining reliable strain data on the carbon-carbon panels are described. The failure modes of the carbon-carbon panels are examined.
Cu(I)-catalyzed Huisgen azide-alkyne 1,3-dipolar cycloaddition reaction in nucleoside, nucleotide, and oligonucleotide chemistry.

Pioneered by Huisgen in the 1960’s1, the 1,3-dipolar cycloaddition reaction between acetylenes and azides was brought back into focus by Sharpless and others2 when they developed the concept of “click chemistry”. This approach, based on the joining of smaller units mimics the approach used by nature to generate substances. This concept takes advantage of reactions that are modular, wide in scope, stereospecific, high yielding, and generate only non-offensive by-products to efficiently access new useful compounds. Moreover, to be completely “click”, the process must involve simple reaction conditions, readily available starting materials and reagents, the use of no solvent, or a benign or easily removable solvent.3 At first, the classical Huisgen 1,3-dipolar cycloaddition did not fall into the above definition, but the discovery of copper (I) salts catalyzing the reaction first by Medal and then by Sharpless4 allowed chemists to evolve from harsh reaction conditions that lead to a mixture of 1,4- and 1,5- regio-isomers to a regioselective reaction which can be performed at room temperature in very short reaction times (Scheme 1). The Cu alkyne-azide cycloaddition (CuAAC) fit so well into the above definition that it has become almost synonymous of “click chemistry” itself. Open in a separate window Scheme 1 1,3-Dipolar Cycloaddition Between Azides and Alkynes
R-matrix analysis of reactions in the 9B compound system

Abstract Recent activity in solving the ‘lithium problem’ in big bang nucleosynthesis has focused on the role that putative resonances may play in resonance-enhanced destruction of 7 Li. Particular attention has been paid to the reactions involving the 9 B compound nuclear system, d+ 7 Be→ 9 B. These reactions are analyzed via the multichannel, two-body unitary R -matrix method using the code EDA developed by Hale and collaborators. We employ much of the known elastic and reaction data, in a four-channel treatment. The data include elastic 3 He+ 6 Li differential cross sections from 0.7 to 2.0 MeV, integrated reaction cross sections for energies from 0.7 to 5.0 MeV for 6 Li( 3 He,p) 8 Be * and from 0.4 to 5.0 MeV for the 6 Li( 3 He,d) 7 Be reaction. Capture data have been added to an earlier analysis with integrated cross section measurements from 0.7 to 0.825 MeV for 6 Li( 3 He, γ ) 9 B. The resulting resonance parameters are compared with tabulated values, and previously unidentified resonances are noted. Our results show that there are no near d+ 7 Be threshold resonances with widths that are 10's of keV and reduce the likelihood that a resonance-enhanced mass-7 destruction mechanism, as suggested in recently published work, can explain the 7 Li problem.
Comments on Long Trains

In this paper, equations of motion appropriate to long trains are derived which include the effects of undulating terrain. The formulation of a nonlinear dynamic programming problem to be applied to "programmed braking" is presented and the class of problems within the capability of available computing equipment is discussed. An analysis of the effect of undulating terrain on the operational response of long travelling at constant speed is presented in detail and numerical results for particular train configurations are given. In particular, the critical velocity for longitudinal resonance as a function of train length and terrain characteristic is given, and from the specialized results for the uniform train it is possible to discern the influence of changes in car mass, coupling stiffness, and so on.
KNOT GROUP EPIMORPHISMS

Let G be a finitely generated group, and let λ ∈ G. If there exists a knot k such that πk = π1(S3\k) can be mapped onto G sending the longitude to λ, then there exists infinitely many distinct prime knots with the property. Consequently, if πk is the group of any knot (possibly composite), then there exists an infinite number of prime knots k1, k2, … and epimorphisms ⋯ → πk2 → πk1 → πk each perserving peripheral structures. Properties of a related partial order on knots are discussed.
Chronic Granulomatous Disease

Chronic granulomatous disease (CGD) was first described in the 1950s and has become a paradigm for genetic neutrophil diseases. It is characterized by recurrent infections with a narrow spectrum of bacteria and fungi as well as a common set of inflammatory complications most notably including inflammatory bowel disease. Over the last half century major advances in management have profoundly altered the major clinical issues and the life expectancy of CGD. With X-linked and autosomal recessive forms, it has been an important disease for the development of bone marrow transplantation and gene therapy. Some of the recent developments in infectious syndromes, inflammatory complications, and curative approaches are discussed in this review.
Current degradation due to electromechanical coupling in GaN HEMT's

Abstract In this work we first report on a theoretical model which provides the gate voltage dependence of the piezoelectric polarization charge in GaN HEMT devices. The model utilizes a generalization of Gauss' law, imposing constraints on the electric displacement vector D. The constraint on D is given by the continuity of the perpendicular component of the displacement vector across an interface. Poisson's equation is then solved across various layers under proper boundary conditions for the applied bias. The piezoelectric polarization charge is reduced due to the electromechanical coupling compared to the uncoupled case. Under high sheet electron densities, the correction in the piezoelectric polarization charge is also lower due to smaller electric fields. The theoretical model is then incorporated in the particle-based device simulator and device transfer and output characteristics are calculated without and with the bias dependent polarization charge. We find that percentage change in drain current increases with larger negative bias on the gate, due to the larger vertical electric fields.
Z-axis anisotropic electrical conductor films in adhesive and standalone forms for electrical interconnection

Z-axis electrical conductor films in adhesive and standalone forms were made from nickel particles (one per conduction path) and a polymer matrix (polyvinylidene fluoride for the standalone film and epoxy for the adhesive film). The standalone film was found to exhibit resilience, conducting path pitch 125 µm and z-axis resistance 2 Ω. 4 Ω, 17, 48 Ω, and 160 Ω per connection at z-axis pressures of 1.39 MPa, 0.037 MPa, 0.0046 MPa, and 0 MPa respectively; each connection consisted of one nickel particle, which protruded from both sides of the film; the film exhibited no stress relaxation due to the absence of polymer deformation under z-axis pressure. The adhesive film exhibited pitch 64 µm and z-axis resistance 52 Ω per connection at zero pressure.
Mars Pathfinder Atmospheric Entry Navigation Operations

On July 4, 1997, after traveling close to 500 million km, the Pathfinder spacecraft successfully completed entry, descent, and landing, coming to rest on the surface of Mars just 27 km from its target point. In the present paper, the atmospheric entry and approach navigation activities required in support of this mission are discussed. In particular the flight software parameter update and landing site prediction analyses performed by the Pathfinder operations navigation team are described. A suite of simulation tools developed during Pathfinder''s design cycel, but extendible to Pathfinder operations, are also presented. Data regarding the accuracy of the primary parachute deployemnt algorithm is extracted from the Pathfinder flight data, demonstrating that this algorithm performed as predicted. The increased probability of mission success through the software parameter update process is discussed. This paper also demonstrates the importance of modeling atmospheric flight uncertainties in the estimation of an accurate landing site. With these atmospheric effects included, the final landed ellipse prediction differs from the post-flight determined landing site by less than 0.5 km in downtrack.
Sonar echo analysis

Pulse mode sonar operation is analyzed under the assumption that the scattering object Γ lies in the far fields of both the transmitter and the receiver. It is shown that, in this approximation, the sonar signal is a plane wave s(x · θ0 – t) near Γ, where θ0 is a unit vector directed from the transmitter toward Γ, and similarly the echo is a plane wave e(x · θ – t) near the receiver, where θ is a unit vector directed from Γ toward the receiver. Moreover, if Γ is stationary with respect to the sonar system then it is shown that where s(ω) is the Fourier transform of S(τ) and T+(ωθ,ωθ0) is the scattering amplitude in the direction θ due to the scattering by Γ of a time-harmonic plane wave with frequence ω and propagation direction θ0. A generalization of this relation is derived for moving scatterers.
Testing the reality of strong magnetic fields on T Tauri stars: The naked T Tauri star Hubble 4

High-resolution optical and infrared (IR) echelle spectra of the naked (diskless) T Tauri star Hubble 4 are presented. The K-band IR spectra include four Zeeman-sensitive Ti I lines along with several magnetically insensitive CO lines. Detailed spectrum synthesis combined with modern atmospheric models is used to fit the optical spectra of Hubble 4 in order to determine its key stellar parameters: Teff = 4158 ± 56 K; log g = 3.61 ± 0.50; [M/H] = -0.08 ± 0.05; v sin i = 14.6 ± 1.7 km s-1. These stellar parameters are used to synthesize K-band spectra to compare with the observations. The magnetically sensitive Ti I lines are all significantly broadened relative to the lines produced in the nonmagnetic model, while the magnetically insensitive CO lines are well matched by the basic nonmagnetic model. Models with magnetic fields are synthesized and fitted to the Ti I lines. The best-fit models indicate a distribution of magnetic field strengths on the stellar surface characterized by a mean magnetic field strength of 2.51 ± 0.18 kG. The mean field is a factor of 2.0 greater than the maximum field strength predicted by pressure equipartition arguments. To confirm the reality of such strong fields, we attempt to refit the observed profiles using a two-component magnetic model in which the field strength is confined to the equipartition value representing plagelike regions in one component and the field is allowed to vary in a cooler component representing spots. It is shown that such a model is inconsistent with the optical spectrum of the TiO bandhead at 7055 A.
Ergonomics in a world of new values.

Our perceptions of the world have changed dramatically since the usaional Ergonomics Association was founded in 1959, In the past 17 years, we have come to realize that our energy and mineral resources are exhaustible, that environmental pollution may annihilate us, and that we have to be protected against the technology that we have created for our own benefit. Those 17 years have also soon a marked decrease in satisfaction with the quality of life, and an increase in expectations that life can and should be made safer, richer, and generally better. In many countries, these rising expectations have led to the enactment of laws governing conditions of work, opportunities for employment, and consumer product safety. Most important of all, society is finally beginning to understand that the world constitutes one enormous system, and that changes proposed anywhere have to be evaluated in terms of their long-term effects on that system. This old world with its new values offers important opportunities and cha...
Calculation of Turbulent Boundary Layers Using Equilibrium Thermal Wakes

The combined thermal law of the wall and wake is used as the approximating sequence for the boundary layer temperature profile to solve an integral thermal energy equation for the local Stanton number distribution. The velocity profile in the turbulent boundary layer was taken to be the combined law of the wall and wake of Coles. This allows the solution of an integral form of the x-momentum equation to give the skin friction coefficient distribution. This, along with the velocity profile, is used to solve the thermal energy equation using inner coordinates. The strength of the thermal wake was found by analysis of earlier research results, in the literature, for equilibrium, constant property, turbulent boundary layers. Solutions for the Stanton number distribution with position are found for some adverse pressure gradient boundary layers as well as for those having zero pressure gradient
Studies of the effects of Diapulse treatment of various aspects of wound healing in experimental animals.

A NUMBER OF HOSPITAL and laboratory studies have suggested that the application of pulsed high-frequency electromagnetic energy dramatically reduces the time required for complete healing of many wounds [l, 2, 3, 5, 61. These reports indicated that this treatment might have a beneficial effect upon the healing of burn wounds [2,4,8]. Therapeutic pulsed high-frequency energy is generated by the Diapulse machine, manufactured by the Diapulse Corporation of America [S]. In an attempt to more precisely delineate the nature of the effect of Diapulse treatment and the site of its action in the complex process of wound healing, it was decided in this laboratory to test the effect of Diapulse treatment on three different aspects of skin wound healing: epithelial ingrowth, the healing of an experimental burn wound, and wound tensile strength development. The most frequent injury in human burns is the destruction of an area of skin. First and second degree burned areas are capable of regenerating new skin from remaining deep epithelial remnants, but areas with third degree burns cannot do so. Hence closure of such areas can only occur by ingrowth of epithelial elements from the edges toward the center of the wounds or by wound contraction. Under optimal conditions epithelialization occurs at’ the rate of about 1 mm/day in humans so there would be obvious advantages in any therapeutic modality that significantly accelerated the rate of reepithelialization, no
The role of exciplexes in the photoreduction of quinolinemethanols

The photoreduction of a family of quinolinemethanols has been examined both in the presence and absence of exciplex-forming additives. Photoreduction of the alcohol group and cleavage of the side chain occurs on direct photolysis. However, irradiation with triethylamine led to predominant cleavage of the side chain while irradiation with 1,3-dicyanobenzene predominantly led to photoreduction of the alcohol functionality. A variety of other experiments supported the involvement of exciplexes in these transformations.
Insights into adenosine deaminase deficiency provided by murine fetal thymic organ culture with 2'-deoxycoformycin.

Adenosine deaminase (ADA) deficiency as a cause of severe combined immunodeficiency (SCID) was first described twenty-five years ago.1 One striking feature of this disease is that although the enzyme is missing in every cell in the body, the immune system is most severely affected. There is an almost complete absence of T cells and a variable decrease in the number of B cells. Gene therapy trials for ADA deficiency are well underway,2,3 and ADA knockout mice have been generated by two groups4,5 as a model to study this disease. Yet even after twenty-five years, the selective lymphotoxicity of ADA deficiency is still not understood. Understanding the mechanism of lymphotoxicity will not only teach us about the pathophysiology of this uncommon disease, but may lend insights into the therapy of this disease and the therapy of other lymphoid developmental defects. It may also give us clues to the design of new therapeutic options for more common lymphoid diseases such as malignancies, and will certainly teach us more about normal lymphocyte development.
Past, present and future of biohydrometallurgy

The history of sulfidic ore leaching and the relatively recent discovery of microbial involvement in the process and its commercial exploitation are summarized. A possible future developmental direction is indicated.
Generalized-ensemble simulations of the human parathyroid hormone fragment PTH(1-34).

A generalized-ensemble technique, multicanonical sampling, is used to study the folding of a 34-residue human parathyroid hormone fragment. An all-atom model of the peptide is employed and the protein–solvent interactions are approximated by an implicit solvent. Our results demonstrate that generalized-ensemble simulations are well suited to sample low-energy structures of such large polypeptides. Configurations with a root-mean-square deviation to the crystal structure of less than 1 A are found. Finally, we discuss limitations of our implicit solvent model.
On the Extension of 2-Polynomials

Let $X$ be a three dimensional real Banach space. Benitez and Otero \cite {BeO} showed that if the unit ball of $X$ is is an intersection of two ellipsoids, then every 2-polynomial defined in a linear subspace of $X$ can be extended to $X$ preserving the norm. In this article, we extend this result to any finite dimensional Banach space.
Alkene Chemoselectivity in Ruthenium‐Catalyzed Z‐Selective Olefin Metathesis

Chelated ruthenium catalysts can facilitate highly chemoselective olefin metathesis. Terminal and internal Z olefins reacted selectively to form new Z olefins in the presence of internal E olefins. Chemoselectivity for terminal olefins was also observed over both sterically hindered and electronically deactivated alkenes.
Cointegration and Long-Run Asset Allocation

We show that economic restrictions of cointegration between asset cash flows and aggregate consumption have important implications for return dynamics and optimal portfolio rules, particularly at long investment horizons. When cash flows and consumption share a common stochastic trend (i.e., are cointegrated), temporary deviations between their levels forecast long-horizon dividend growth rates and returns, and consequently, alter the term profile of risks and expected returns. We show that the optimal asset allocation based on the error-correction vector autoregression (EC-VAR) specification can be quite different relative to a traditional VAR that ignores the cointegrating relation. Unlike the EC-VAR, the commonly used VAR approach to model expected returns focuses on short-run forecasts and can considerably miss on long-horizon return dynamics, and hence, the optimal portfolio mix in the presence of cointegration. We develop and implement methods to account for parameter uncertainty in the EC-VAR setup...
Neonatal herpes simplex virus infections

Neonatal herpes simplex virus infections are a common problem in the United States, occurring at an incidence of one in approximately 3,500 deliveries. In the absence of antiviral therapy significant morbidity and mortality is attendant with disease. Disease manifestations in the newborn include multiorgan involvement (disseminated disease), encephalitis, and/or infection limited to the skin, eye, or mouth. These three broad classifications provide distinctions in severity of disease for evaluation of outcome following antiviral therapy. The availability of antiviral therapy for life-threatening disease, particularly that which is disseminated or involves the brain, has been of particular benefit for children with neonatal herpes. Both acyclovir and vidarabine have proven effective in the management of neonatal herpes simplex virus infection. With current therapeutic modalities, mortality from disease localized to the skin, eye, and mouth is virtually non-existent, yet a few children (approximately 5%) are still at risk for a long-term neurologic sequelae. For babies with encephalitis, the mortality has been reduced to approximately 15% and nearly 50% of survivors develop normally 3 years after treatment. Outcome with disseminated infection is of less value as mortality remains high (50%), but the number of survivors who develop normally is approximately 85%. The introduction of new antivirals with enhanced lipophilicity and, potentially, greater activity in the central nervous system may further improve outcome from this devastating disease.
Bounds and asymptotic minimal growth for Gorenstein Hilbert functions

Abstract We determine new bounds on the entries of Gorenstein Hilbert functions, both in any fixed codimension and asymptotically. Our first main theorem is a lower bound for the degree i + 1 entry of a Gorenstein h-vector, in terms of its entry in degree i. This result carries interesting applications concerning unimodality: indeed, an important consequence is that, given r and i, all Gorenstein h-vectors of codimension r and socle degree e ⩾ e 0 = e 0 ( r , i ) (this function being explicitly computed) are unimodal up to degree i + 1 . This immediately gives a new proof of a theorem of Stanley that all Gorenstein h-vectors in codimension three are unimodal. Our second main theorem is an asymptotic formula for the least value that the ith entry of a Gorenstein h-vector may assume, in terms of codimension, r, and socle degree, e. This theorem broadly generalizes a recent result of ours, where we proved a conjecture of Stanley predicting that asymptotic value in the specific case e = 4 and i = 2 , as well as a result of Kleinschmidt which concerned the logarithmic asymptotic behavior in degree i = ⌊ e 2 ⌋ .