cssi/SciSciGPT-SciSciNet huggingface dataset:
Sequelae of recurrent laryngeal nerve injury after patent ductus arteriosus ligation

Summary Objectives To prospectively study the clinical course of neonates with vocal cord paralysis (VCP) after patent ductus arteriosus (PDA) ligation. Methods A prospective cohort study of all premature infants undergoing PDA ligation from March 2001 to February 2004. Flexible laryngoscopy was performed after extubation to assess vocal cord function. Data regarding patient characteristics, operative findings, post-operative endoscopic findings, and the subsequent clinical course were collected. Results One hundred patients were enrolled. Flexible laryngoscopy was performed on 61 patients. Median birth weight was 740 g, gestational age 25 weeks, and age at operation 23 days. Flexible laryngoscopy was performed at an average of 8 days after extubation. Seven cases of vocal cord paralysis were identified. Two had stridor and feeding difficulty requiring nasogastric feeding. Five of the seven had an average follow-up of 9 months after surgery. At last follow-up, endoscopically satisfactory compensation by the normal vocal cord was observed in all five patients. No patient had feeding problems. Conclusions The majority of infants who can be successfully extubated after PDA ligation tend to be asymptomatic despite vocal cord paralysis. Compensation appears to occur rapidly, and patients generally have no *long-term problems with the airway or feeding.
Linked by loops: Network structure and switch integration in complex dynamical systems

Abstract Simple nonlinear dynamical systems with multiple stable stationary states are often taken as models for switchlike biological systems. This paper considers the interaction of multiple such simple multistable systems when they are embedded together into a larger dynamical “supersystem.” Attention is focused on the network structure of the resulting set of coupled differential equations, and the consequences of this structure on the propensity of the embedded switches to act independently versus cooperatively. Specifically, it is argued that both larger average and larger variance of the node degree distribution lead to increased switch independence . Given the frequency of empirical observations of high variance degree distributions (e.g., power-law) in biological networks, it is suggested that the results presented here may aid in identifying switch-integrating subnetworks as comparatively homogenous, low-degree, substructures. Potential applications to ecological problems such as the relationship of stability and complexity are also briefly discussed.
Fluorous synthesis of disubstituted pyrimidines.

The fluorous synthesis of disubstituted pyrimidines is carried out by attaching 2,4-dichloro-6-methylpyrimidine with 1H,1H,2H,2H-perfluorodecanethiol. The tagged substrate is substituted with 3-(trifluoromethyl)pyrazole followed by thioether oxidation and tag displacement with amines or thiols. The fluorous chain serves as a phase tag for intermediate and product purification over FluoroFlash SPE cartridges.
Gait Recovery in Healthy Subjects : Perturbations to the Knee Motion with a Smart Knee Brace

The Smart Knee Brace (SKB) is designed to provide controlled perturbations to the human knee during walking. A motion capture system records the gait movement before and after these perturbations t...
Minimum product set sizes in nonabelian groups of order pq

Article history: Let G be a nonabelian group of order pq ,w herep and q are distinct odd primes. We analyze the minimum product set cardinality μG (r, s) = min| AB | ,w here A and B range over all subsets of G of cardinalities r and s, respectively. In this paper, we completely determine μG (r, s) in the case where G has order 3p and conjecture that this result can be extended to all nonabelian groups of order pq. We also prove that for every nonabelian group of order pq there exist 1 r, s pq such that μG (r, s )>
Automatic differentiation tools in optimization software

We discuss the role of automatic differentiation tools in optimization software. We emphasize issues that are important to large-scale optimization and that have proved useful in the installation of nonlinear solvers in the NEOS Server. Our discussion centers on the computation of the gradient and Hessian matrix for partially separable functions and shows that the gradient and Hessian matrix can be computed with guaranteed bounds in time and memory requirements.
Predictions of Melt-through Times for Laser Heating

Theme principal effect of high intensity continuous laser radiation on a metallic target is a temperature rise leading to melting, and possibly vaporization. Times required for complete melt-through of metal sheets are considered. A numerical method for predicting the thermal response is applied to obtain general conclusions on the influence of radial conduction and melt removal on the melting time. New variables which lead to a means of quickly estimating meltthrough times from a given curve and formulas, are introduced.
GENETIC FACTORS IN HUMAN OBESITY

Demonstration of the hereditary nature of familial obesity in man is difficult. Cultural background acts with genetics to determine the incidence of overweight. Studies have indicated that overweight per se is probably an unsatisfactory phenotype in the study of the genetics of obesity. The approaches used thus far in determining hereditary obesity will have to be pursued until specific inborn errors of the regulation of food intake or of fat metabolism are recognized and identified in man.
Spin and charge dynamics of chromium alloys

Abstract Both the spin- and charge-density waves of Cr alloys are produced by the Coulomb attraction between electrons and holes on nearly nested Fermi surfaces. Driven by quasiparticle transitions, transverse spin-wave and longitudinal phason modes are associated with the rotational and translational symmetries of pure Cr and its dilute alloys. At low frequencies, both spin and charge phasons have a nearly linear dispersion with a mode velocity which approaches the spin-wave velocity as T approaches TN or as the mismatch between the Fermi surfaces increases.
High voltage thin film transistors integrated with MEMS

Abstract The integration of high voltage thin film transistors with a released MEMS process onto the same substrate is demonstrated. High voltage transistors capable of 800 V actuation voltage are used to actuate released metal cantilevers and membranes with a low temperature fabrication process (
Potential biases in inferring Holocene temperature trends from long‐term borehole information

[1] We use a set of global coupled ocean-atmosphere general circulation (OAGCM) experiments for timeslices over the Holocene from 9K Yr BP onwards to examine differences in Northern Hemisphere Ground Surface Temperature (GST) and Surface Air Temperature (SAT) trends. The model results are driven mainly by the orbitally-forced changes in seasonal insolation, and in particular, the increase in northern hemisphere seasonality in the early-to-mid Holocene. The model reproduces qualitatively presumed past trends in NH temperatures, though it may underestimate their magnitude. For this period, we see on average a significant increase in GST relative to SAT as a result of a competition between the effects of changing seasonal insolation, and the varying extent of insulating seasonal snow cover. The model shows a mid-Holocene peak in annual mean terrestrial Northern Hemisphere GST, but not in annual Surface Air Temperatures (SAT). We conclude that the factors influencing long-term GST trends are potentially quite complex, and that considerable care must be taken in interpreting SAT changes from the GST evidence when there is the possibility of substantial seasonal variation in warmth and snow cover.
The Role of Adsorbed Water on the Friction of a Layer of Submicron Particles

Anomalously low values of friction observed in layers of submicron particles deformed in simple shear at high slip velocities are explained as the consequence of a one nanometer thick layer of water adsorbed on the particles. The observed transition from normal friction with an apparent coefficient near μ = 0.6 at low slip speeds to a coefficient near μ = 0.3 at higher slip speeds is attributed to competition between the time required to extrude the water layer from between neighboring particles in a force chain and the average lifetime of the chain. At low slip speeds the time required for extrusion is less than the average lifetime of a chain so the particles make contact and lock. As slip speed increases, the average lifetime of a chain decreases until it is less than the extrusion time and the particles in a force chain never come into direct contact. If the adsorbed water layer enables the otherwise rough particles to rotate, the coefficient of friction will drop to μ = 0.3, appropriate for rotating spheres. At the highest slip speeds particle temperatures rise above 100°C, the water layer vaporizes, the particles contact and lock, and the coefficient of friction rises to μ = 0.6. The observed onset of weakening at slip speeds near 0.001 m/s is consistent with the measured viscosity of a 1 nm thick layer of adsorbed water, with a minimum particle radius of approximately 20 nm, and with reasonable assumptions about the distribution of force chains guided by experimental observation. The reduction of friction and the range of velocities over which it occurs decrease with increasing normal stress, as predicted by the model. Moreover, the analysis predicts that this high-speed weakening mechanism should operate only for particles with radii smaller than approximately 1 μm. For larger particles the slip speed required for weakening is so large that frictional heating will evaporate the adsorbed water and weakening will not occur.
INCLUDING ROADWAY AND TREAD FACTORS IN A SEMI-EMPIRICAL MODEL OF TRUCK TYRES

Abstract A semi-empirical tire model is described here and used in examining the influences of changes in (a) tire tread depth and (b) pavement mean texture depth and skid number on tire forces. Test results show that changes in tread depth lead to changes in cornering stiffness and the form of the pressure distribution. The ways in which these factors are included in the model and their influences on lateral force characteristics of truck tires are presented and discussed. The influences of tread depth, mean texture depth, and skid number on die sliding friction of truck tires are discussed and equations for representing the frictional characteristics of a worn tire operating on a wet surface (not flooded to a level well over the tops of the road asperities) are presented in an appendix. The body of the paper concludes with a discussion of future approaches for representing frictional effects.
COMPARATIVE STUDIES ON SYNTHESIS AND PROPERTIES OF PHOSPHORUS AND SULFUR HETEROCYCLES: THE HETERONIN OXIDE SYSTEM

Abstract Phosphonin oxides are the first recognizable product on reaction of 9-phosphabicyclo[6.1.0]nona-2,4,6-trienes with peroxides at −15°C. These compounds (R = C6H5 or t-C4H9) are stable below −15°C, but undergo intramolecular cycloaddition to give trans-3a,7a-dihydrophosphindoles on warming to room temperature. The reaction applied to the sulfur counterpart of the phosphine gave only the 9-thiabicyclo[4.2.1]nonatriene system, but oxidation with sodium periodate at −15°C gave a 34% yield of a product identified conclusively as cis-3a,7a-dihydrobenzo[b]thiophene oxide, which must have arisen from a thionin oxide. This is the first evidence for the formation of a noncyclic thionin derivative.
Laser-evaporated aluminum atom reactions with halogen molecules. Infrared spectra of AlXn (X = F, Cl, Br, I; n = 1-3) in solid argon

Reactions of laser-evaporated aluminum atoms with molecular fluorine, chlorine, bromine, and iodine in excess argon during condensation onto a CsI window at 11 ± 1 K produced the AlXn (X = F, Cl, Br, I and n = 1−3) and Al2X6 molecules, which were characterized by infrared absorption spectroscopy. Low laser power favored the primary reaction product AlX and AlX2 transient species over the more stable secondary reaction product AlX3 molecules. Chlorine and bromine isotopic structures substantiated the molecular identifications and vibrational assignments. DFT calculations were done for the AlCln and AlBrn series to support the vibrational assignments. Possible Al2Cl4 structures were also explored by DFT calculations, and evidence is presented for a distorted Cl2AlCl2Al structure. The present study provides further evidence for transient aluminum dihalide radicals for the four halogens.
MEAN CURVATURE MOTION OF GRAPHS WITH CONSTANT CONTACT ANGLE AT A FREE BOUNDARY

We consider the motion by mean curvature of an n-dimensional graph over a time-dependent domain in ℝn intersecting ℝn at a constant angle. In the general case, we prove local existence for the corresponding quasilinear parabolic equation with a free boundary and derive a continuation criterion based on the second fundamental form. If the initial graph is concave, we show this is preserved and that the solution exists only for finite time. This corresponds to a symmetric version of mean curvature motion of a network of hypersurfaces with triple junctions with constant contact angle at the junctions.
Focal Plane Architecture: An Overview

The advent of mosaic focal planes, with their accompanying complexity, demands a clear delineation and a wide perspective of architectural levels for the optimum design and integration of focal planes. This overview describes the important characteristics of the various architectural levels, pinpoints the main constraints on focal plane architecture, and highlights the major issues and trends in focal plane technology.
Realizations and LP

Abstract LP can be seen as a logic of knowledge with justifications. See [S. Artemov, The logic of justification, The Review of Symbolic Logic 1 (4) (2008) 477–513] for a recent comprehensive survey of justification logics generally. Artemov’s Realization Theorem says justifications can be extracted from validities in the more conventional Hintikka-style logic of knowledge S4 , in which they are not explicitly present. Justifications, however, are far from unique. There are many ways of realizing each theorem of S4 in the logic LP . If the machinery of justifications is to be applied to artificial intelligence, or better yet, to everyday reasoning, we will need to work with whatever justifications we may have at hand—one version may not be interchangeable with another, even though they realize the same S4 formula. In this paper we begin the process of providing tools for reasoning about justifications directly. The tools are somewhat complex, but in retrospect this should not be surprising. Among other things, we provide machinery for combining two realizations of the same formula, and for replacing subformulas by equivalent subformulas. (The second of these is actually weaker than just stated, but this is not the place for a detailed formulation.) The results are algorithmic in nature—semantics for LP plays no role. We apply our results to provide a new algorithmic proof of Artemov’s Realization Theorem itself. This paper is a much extended version of [M.C. Fitting, Realizations and LP, in: S. Artemov, A. Nerode (Eds.), Logical Foundations of Computer Science—New York ’07, in: Lecture Notes in Computer Science, vol. 4514, Springer-Verlag, 2007, pp. 212–223].
Gravitons and the Drell–Hearn–Gerasimov sum rule

Abstract One-loop diagrams containing a graviton provide a finite contribution to the anomalous magnetic moment a l of a lepton, whether or not the graviton propagates in n large extra compact dimensions. In the present work, the tree graph photoproduction of a graviton, integrated up to an arbitrary cutoff, is shown to violate the Drell–Hearn–Gerasimov sum rule for a l 2 . The possibility of resurrecting the sum rule from high energy contributions originating in string excitations is discussed in a qualitative manner, and various problems associated with such a program are pointed out.
Thermal Inspection of Composite Honeycomb Structures

Composite honeycomb structures continue to be widely used in aerospace applications due to their low weight and high strength advantages. Developing nondestructive evaluation (NDE) inspection methods are essential for their safe performance. Pulsed thermography is a commonly used technique for composite honeycomb structure inspections due to its large area and rapid inspection capability. Pulsed thermography is shown to be sensitive for detection of face sheet impact damage and face sheet to core disbond. Data processing techniques, using principal component analysis to improve the defect contrast, are presented. In addition, limitations to the thermal detection of the core are investigated. Other NDE techniques, such as computed tomography X-ray and ultrasound, are used for comparison to the thermography results.
Interference Alignment as a Rank Constrained Rank Minimization

We show that the maximization of the sum degrees-of-freedom for the static flat-fading multiple-input multiple-output (MIMO) interference channel (IC) is equivalent to a rank constrained rank minimization problem (RCRM), when the signal subspaces span all available dimensions. The rank minimization corresponds to maximizing interference alignment (IA) so that interference spans the lowest dimensional subspace possible. The rank constraints account for the useful signal subspaces spanning all available spatial dimensions. That way, we reformulate the IA requirements to requirements involving ranks. Then, we present a convex relaxation of the RCRM problem inspired by recent results in compressed sensing and low-rank matrix completion theory that rely on approximating rank with the nuclear norm. We show that the convex envelope of the sum of ranks of the interference matrices is the normalized sum of their corresponding nuclear norms and replace the rank constraints with asymptotically equivalent and tractable ones. We then tune our heuristic relaxation for the multicell interference channel. We experimentally show that in many cases the proposed algorithm attains perfect interference alignment and in some cases outperforms previous approaches for finding precoding and receive matrices for interference alignment.
New synthetic technology for the construction of N-hydroxyindoles and synthesis of nocathiacin I model systems

A new synthetic method providing expedient access to a wide range of polyfunctionalized N-hydroxyindoles (IV) is reported. These unique constructs are assembled by nucleophilic additions to in situ generated α,β-unsaturated nitrones (III) through carbon–carbon and carbon–heteroatom bond formation. The new synthetic technology was applied to the synthesis of nocathiacin I (1) model systems (2 and 3a–c) containing the N-hydroxyindole structural motif.
Advances in the chemistry of oxaziridines.

Oxaziridines constitute a subset of a class of versatile oxidants whose characteristic feature is the presence of two electronegative heteroatoms within a strained three-membered ring (Figure ​(Figure1).1). Other small organic heterocycles in this class include diaziridines1 and dioxiranes,2 which have been developed as reagents for a variety of oxidative transformations. η2-Peroxo and η2-hydroperoxy complexes of various transition metals are also members of this class,3 and these structures are the active oxidizing species in a broad range of synthetically useful oxidative transformations, including the Sharpless asymmetric epoxidation,4 VO(acac)2-catalyzed epoxidations,5 and MeReO3-catalyzed hydroxylation of unactivated alkanes.6 Peroxometal complexes are relevant in biological systems as well; dinuclear μ-η2:η2-peroxodicopper(II) complexes found within the active sites of metalloenzymes such as hemocyanin and tyrosinase have been extensively studied for their role in oxygen metabolism.7 Figure 1 Representative oxidizing heterocycles with two electrophilic heteroatoms within a three-membered ring.
Dear Santa: heavy flavour physics at neutrino factories—desires from theory

Abstract Even in 2010, the CKM parameters V cs , V cd and V ub will be known with less than desirable accuracy; the discovery potential for New Physics in charm decays—in particular, their CP asymmetries—will be far from exhausted; important tests of our theoretical tools will not have been performed. I sketch the impact a ν fact could have in these areas.
Regularization dependence of the Higgs mass triviality bound

Abstract We calculate the triviality bound on the Higgs mass in scalar field theory models whose global symmetry group SU(2)L × SU(2)custodial ≈ O(4) has been replaced by O(N) and N has been taken to infinity. Limits on observable cutoff effects at four percent in several regularized models with tunable couplings in the bare action yield triviality bounds displaying a large degree of universality. Extrapolating from N = ∞ to N = 4 we conservatively estimate that a Higgs particle with mass up to 0.750 TeV and width up to 0.290 TeV is realizable without large cutoff effects, indicating that strong scalar self interactions in the standard model are not ruled out. We also present preliminary numerical results of the physical N = 4 case for the F4 lattice that are in agreement with the large N expectations.
Alkene-directed, nickel-catalyzed alkyne coupling reactions.

In alkene-directed, nickel-catalyzed coupling reactions of 1,3-enynes with aldehydes and epoxides, the conjugated alkene dramatically enhances reactivity and uniformly directs regioselectivity, independent of the nature of the other alkyne substituent (aryl, alkyl (1°, 2°, 3°)) or the degree of alkene substitution (mono-, di-, tri-, and tetrasubstituted). These observations are best explained by a temporary interaction between the alkene and the transition metal center during the regioselectivity-determining step. The highly substituted 1,3-diene products are useful in organic synthesis and, in conjunction with a Rh-catalyzed, site-selective hydrogenation, afford allylic and homoallylic alcohols that previously could not be prepared in high regioselectivity (or at all) with related Ni-catalyzed alkyne coupling reactions.
International Trade and Currency Exchange

On the international scene, away from national legal rules, the use of different currencies is largely due to the operation of the "Invisible Hand". The paper develops a three-country model of the world economy. This links real trade patterns with currency exchange structures in a general equilibrium framework which includes transaction costs on foreign exchange markets. In the presence of strategic complementarities, there are multiple equilibrium structures of currency exchange for a given underlying real trade pattern. The existence conditions of these different equilibria are characterized, using the trade links between countries as the key parameters. Finally, repercussions on world output of the choice of a currency exchange structure are analysed.
Generation of Light from Free Electrons

Experimental study of the Purcell effect shows that the radiance and character of the light generated by free electrons interacting with a metallic diffraction grating are not compatible with a simple electrostatic-image theory. A variety of experiments indicates other possibilities for theoretical explanation and shows how new experiments are expected to determine a more compatible theory of operation. Although light has been produced throughout the wavelength range from 4 to 0.2 μm, quantum effects appear to be unnecessary in describing the results. Rather, an extension of high-frequency electron-tube theory into multiwavelength three-dimensional optics is indicated.
Ammine Magnesium Borohydride Complex as a New Material for Hydrogen Storage: Structure and Properties of Mg(BH4)2·2NH3

The ammonia complex of magnesium borohydride Mg(BH4)2·2NH3 (I), which contains 16.0 wt % hydrogen, is a potentially promising material for hydrogen storage. This complex was synthesized by thermal decomposition of a hexaaammine complex Mg(BH4)2·6NH3 (II), which crystallizes in the cubic space group Fm3m with unit cell parameter a = 10.82(1) A and is isostructural to Mg(NH3)6Cl2. We solved the structure of I that crystallizes in the orthorhombic space group Pcab with unit cell parameters a = 17.4872(4) A, b = 9.4132(2) A, c = 8.7304(2) A, and Z = 8. This structure is built from individual pseudotetrahedral molecules Mg(BH4)2·2NH3 containing one bidentate BH4 group and one tridentate BH4 group that pack into a layered crystal structure mediated by N−H···H−B dihydrogen bonds. Complex I decomposes endothermically starting at 150 °C, with a maximum hydrogen release rate at 205 °C, which makes it competitive with ammonia borane BH3NH3 as a hydrogen storage material.
How do migrants fare in a post-apartheid South African labor market?

South African policies have historically emphasized employment as the reason for immigration. In post-apartheid South Africa, stories about how “immigrants take away our jobs” abound in the mass media, yet few empirical studies have been undertaken to examine the validity of this claim. This study looks at the relationship between migration status, nativity and labor force outcomes in the post-apartheid labor market. Our results suggest that migrants are more likely to participate in the labor force and to be gainfully employed than the indigenous population. Foreign migrants enjoy the highest labor force participation rates and employment rates in South Africa. South African-born internal migrants also have significantly higher labor force outcomes than do nonmigrants.
Fast and Numerically Stable Circle Fit

We develop a new algorithm for fitting circles that does not have drawbacks commonly found in existing circle fits. Our fit achieves ultimate accuracy (to machine precision), avoids divergence, and is numerically stable even when fitting circles get arbitrary large. Lastly, our algorithm takes less than 10 iterations to converge, on average.
Rayleigh Laser Guide Star Systems: UnISIS Bow-Tie Shutter and CCD39 Wavefront Camera

Laser guide star systems based on Rayleigh scattering require some means to deal with the flash of low-altitude laser light that follows immediately after each laser pulse. These systems also need a fast shutter to isolate the high-altitude portion of the focused laser beam to make it appear starlike to the wavefront sensor. We describe how these tasks are accomplished with UnISIS, the Rayleigh laser-guided adaptive optics system at the Mount Wilson Observatory 2.5 m telescope. We use several methods: a 10,000 revolution per minute rotating disk, dichroics, a fast sweep and clear mode of the CCD readout electronics on a 10 μs timescale, and a Pockel's cell shutter system. The Pockel's cell shutter would be conventional in design if the laser light were naturally polarized, but the UnISIS 351 nm laser is unpolarized. Therefore, we have designed and put into operation a dual Pockel's cell shutter in a unique bow-tie arrangement.
Optimization-based influencing of village social networks in a counterinsurgency

This article considers the nonlethal targeting assignment problem in the counterinsurgency in Afghanistan, the problem of deciding on the people whom U.S. forces should engage through outreach, negotiations, meetings, and other interactions in order to ultimately win the support of the population in their area of operations. We propose two models: (1) the Afghan counterinsurgency (COIN) social influence model, to represent how attitudes of local leaders are affected by repeated interactions with other local leaders, insurgents, and counterinsurgents, and (2) the nonlethal targeting model, a NonLinear Programming (NLP) optimization formulation that identifies a strategy for assigning k U.S. agents to produce the greatest arithmetic mean of the expected long-term attitude of the population. We demonstrate in an experiment the merits of the optimization model in nonlethal targeting, which performs significantly better than both doctrine-based and random methods of assignment in a large network.
Optomechanical crystals and their quantum optical applications

In the last several years, rapid advances have been made in the field of cavity optomechanics, in which the usually feeble radiation pressure force of light is used to manipulate (and precisely monitor) mechanical motion [1–3]. These advances have moved the field from the multi-km interferometer of a gravitational wave observatory, to the optical table top, and now all the way down to a silicon microchip [4]. In this talk I will describe these advances, and discuss our own work to realize radiation pressure within nanoscale structures in the form of coupled photonic and phononic crystals (dubbed optomechanical crystals; see Figure 1 below) [5]. Applications of these new nano-opto-mechanical systems include: all-optically tunable photonics, optically powered RF and microwave oscillators, and precision force/acceleration and mass sensing. Additionally there is the potential for these systems to be used in hybrid quantum networks, enabling storage or transfer of quantum information between disparate quantum systems. I will introduce several conceptual ideas regarding phonon-photon translation [6] and slow light effects [7] which may be used in such quantum settings, and discuss recent experiments to realize them in practice [8].
A Lewis Acid-Catalyzed Procedure for the Conversion of 2-Methoxyethoxymethyl Ethers to Carboxylic Esters

Abstract A procedure for the conversion of 2-methoxy-ethoxymethyl (MEM) ethers to carboxylic esters employed ferric chloride (0.4 equivalents) and a carboxylic anhydride (14 equivalents) and exhibited selectivity for the MEM ether functionality in the presence of benzyl ethers.
A stochastic model for change in group structure

Abstract This paper develops and tests a continuous time discrete state Markov Chain as a model for change in group structure. Movement of triads among different states is focused upon. It is shown formally that a triad cannot move to a state where all the pair relationships are mutual without incurring intransitivity. An empirical test on the change in sociometric structures provides support for the model.
Link Floer homology and the Thurston norm

We show that link Floer homology detects the Thurston norm of a link complement. As an application, we show that the Thurston polytope of an alternating link is dual to the Newton polytope of its multi-variable Alexander polynomial. To illustrate these techniques, we also compute the Thurston polytopes of several specific link complements.
A PROGRAM OF HUMAN ENGINEERING

Summary A resume of the manner in which the field of “human engineering” arose is presented together with a specification of what is encompassed by the term. This is followed by an outline of major topics of the field and representative experiments for each topic. These researches indicate that human engineering is not a science or field of endeavor unto itself. Rather it is a technical service which our society now demands. Recent interest in the phrase merely indicates that individuals from many professions, particularly the engineering and biological sciences, have discovered that they can and should be of mutual assistance in solving the problems of fitting man to the complexities of his contemporary work situation.
Synthesis of a close analog of the repeating unit of the antifreeze glycoproteins of polar fish

Abstract The protected glycopeptide N -(benzyloxycarbonyl)- l -alanyl-[ O -(2,3,4,6-tetra- O -benzoyl-β- d -galactopyranosyl)-(1→3)- O - (2,4,6-tri- O -benzyl-α- d -galactopyranosyl)-(1→3)]- l -threonyl- l -alanine 2,2,2-trichloroethyl ester ( 21 ) was made by coupling the respective disaccharide and tripeptide blocks. The disaccharide block was generated by coupling tetra- O -benzoyl-α- d -galactopyranosyl bromide to allyl 2,4,6-tri- O -benzyl-α- d -galactopyranoside and converting the product into O -(2,3,4,6-tetra- O -benzoyl-β- d -galactopyranosyl)-(1→3)-2,4,6-tri- O -benzyl-α- d -galactopyranosyl chloride ( 6 ) via the 1-propenyl glycoside and the free (1-OH) sugar. Alternatively, the 1-propenyl intermediate was obtained directly by using 1-propenyl 2,4,6-tri- O -benzyl-α- d -galactopyranoside ( 10 ) as the acceptor in the initial coupling reaction. An efficient 3-step synthesis of 10 was accomplished by the dibutyltin oxide-assisted, selective crotylation of allyl α- d -galactopyranoside at O-3, followed by benzylation and treatment of the product with potassium tert -butoxide. The N -benzyloxycarbonyl (Z) and N-tert -butoxycarbonyl (Boc) 2,2,2-trichloroethyl esters of Thr-Ala and Ala-Thr-Ala were formed by sequential coupling. The silver triflate-promoted glycosylation of the Z-protected dipeptide and tripeptide by 2,3,4,6-tetra- O -benzyl-α- d -galactopyranosyl chloride, and of the tripeptide by 6 , proceeded with excellent α-stereoselectivity. From the disaccharide tripeptide 21 , the carboxyl-deprotected and fully deprotected derivatives were prepared.
Tricritical behavior in the ferromagnetic superconductor ErRh4B4

Abstract A new tricritical point on the phase boundary between the superconducting vortex phase and the normal paramagnetic phase of ErRh 4 B 4 is presented. The microscopic origin of the tricritical point and the expected tricritical behavior are briefly discussed.
Information-preserving image data compression

This paper deals with both the theoretical and the practical aspects of information preserving image data compression. The concept of entropy and the common effective compression algorithms are first reviewed. The first-order, second-order and the conditional entropies of images are calculated and compared to the compression level of some existing algorithms. A set of reversible transformation techniques are then introduced and applied to the referenced images. The purpose of these transformations is to lower the entropy in order to improve the compression ratio of the compression algorithms. The effect of the transformations on the compression algorithms are examined. Finally, suggestions for further research in lossless compression are given.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A finite element study of the deformations, forces, stress formations, and energy losses in sliding cylindrical contacts

Abstract This work presents the results of a finite element analysis (FEA) used to simulate two-dimensional (2D) sliding between two interfering elasto-plastic cylinders. The material for the cylinders is modeled as elastic-perfectly plastic and follows the von Mises yield criterion. The FEA provides trends in the deformations, reaction forces, stresses, and net energy losses as a function of the interference and sliding distance between the cylinders. Results are presented for both frictionless and frictional sliding and comparisons are drawn. The effects of plasticity and friction on energy loss during sliding are isolated. This work also presents empirical equations thatt relate the net energy loss due to sliding under an elasto-plastic deformation as a function of the sliding distance. Contour plots of the von Mises stresses are presented to show the formation and distribution of stresses with increasing plastic deformation as sliding progresses. This work shows that for the plastic loading cases the ratio of the horizontal force to the vertical reaction force is non-zero at the point where the cylinders are perfectly aligned about the vertical axis. In addition, a “load ratio” of the horizontal tugging force to the vertical reaction force is defined. Although this is analogous to the common definition of the coefficient of friction between sliding surfaces, it just contains the effect of energy loss in plasticity. The values of the contact half-width are obtained for different vertical interferences as sliding progresses.
Efficient in vivo catheter-based pericardial gene transfer mediated by Adenoviral vectors

Adenoviral vectors are promising agents for a number of in vivo gene therapy applications including diseases of the heart and coronary vessels. Efficient intravascular gene transfer to specific sites has been achieved in occluded vessels, but otherwise is hampered by the effect of blood flow on localized vector uptake in the vessel wall. An alternative delivery approach to coronary arteries is the expression of diffusible gene products into the pericardial space surrounding the heart and coronary arteries. However, in vivo pericardial access is comparatively difficult and has been limited to surgical approaches. We hypothesized that efficient adenovirus-mediated gene expression in pericardial lining mesothelium could be achieved by transmyocardial vector delivery to the pericardium. To evaluate this concept, a hollow, helical-tipped penetrating catheter was used to deliver vector-containing fluid directly into the intrapericardial space. The catheter was introduced percutaneously in anesthetized mongrel dogs, advanced into the right ventricle, and the tip passed through the apical right ventricular myocardium under direct radiographic visualization until the open end of the catheter tip resided in the intrapericardial space. Adenoviral vectors expressing either nuclear-localizing beta-galactosidase, cytoplasmic luciferase, or secreted human alpha 1AT reporters (Av1nBg, Av1Lu, or Av1Aa, respectively) were instilled through the catheter into the intrapericardial space. Three days later the animals were sacrificed and reporter gene expression was evaluated in pericardium, epicardium, and multiple other tissues. In animals receiving Av1nBg, beta-galactosidase activity was evident in most of the pericardial lining endothelium, up to 100% in many areas. In animals receiving Av1Lu, luciferase reporter activity was abundant in pericardial tissues, but near-background levels were observed in other organs. In animals receiving Av1Aa, human alpha 1AT was abundant (16-29 mg/ml) in pericardial fluid, but was undetectable in serum. All animals tolerated the procedure well with no electrocardiographic changes and no clinical sequelae. These observations demonstrate highly efficient adenovirus vector delivery and gene transfer and expression in the pericardium and support the feasibility of localized gene therapy via catheter-based pericardial approaches. We suggest that the pericardial sac may serve as a sustained-release protein delivery system for the generation of desired gene products or their metabolites for diffusion into the epicardial region.
A mountain-scale thermal-hydrologic model for simulating fluid flow and heat transfer in unsaturated fractured rock

A multidimensional, mountain-scale, thermal-hydrologic (TH) numerical model is presented for investigating unsaturated flow behavior in response to decay heat from the radioactive waste repository in the Yucca Mountain unsaturated zone (UZ), Nevada. The model, consisting of both two-dimensional (2-D) and three-dimensional (3-D) representations of the UZ repository system, is based on the current repository design, drift layout, thermal loading scenario, and estimated current and future climate conditions. This mountain-scale TH model evaluates the coupled TH processes related to mountain-scale UZ flow. It also simulates the impact of radioactive waste heat release on the natural hydrogeological system, including heat-driven processes occurring near and far away from the emplacement tunnels or drifts. The model simulations predict thermally perturbed liquid saturation, gas- and liquid-phase fluxes, and water and rock temperature elevations, as well as the changes in water flux driven by evaporation/condensation processes and drainage between drifts. These simulations provide mountain-scale thermally perturbed flow fields for assessing the repository performance under thermal loading conditions.
Finite Time Blow Up for a 1D Model of 2D Boussinesq System

The 2D conservative Boussinesq system describes inviscid, incompressible, buoyant fluid flow in a gravity field. The possibility of finite time blow up for solutions of this system is a classical problem of mathematical hydrodynamics. We consider a 1D model of the 2D Boussinesq system motivated by a particular finite time blow up scenario. We prove that finite time blow up is possible for the solutions to the model system.
Alternative model of thrust-fault propagation

A widely accepted explanation for the geometry of thrust faults is that initial failures occur on deeply buried planes of weak rock and that thrust faults propagate toward the surface along a staircase trajectory. We propose an alternative model that applies Gretener's beam-failure mechanism to a multilayered sequence. Invoking compatibility conditions, which demand that a thrust propagate both upsection and downsection, we suggest that ramps form first, at shallow levels, and are subsequently connected by flat faults. This hypothesis also explains the formation of many minor structures associated with thrusts, such as backthrusts, wedge structures, pop-ups, and duplexes, and provides a unified conceptual framework in which to evaluate field observations.
GeoSTAR: a synthetic aperture microwave sounder for geostationary missions

The Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) is a new microwave atmospheric sounder under development. It will bring capabilities similar to those now available on low-earth orbiting environmental satellites to geostationary orbit - where such capabilities have not been available. GeoSTAR will synthesize the multi-meter aperture needed to achieve the required spatial resolution, which will overcome the obstacle that has prevented a GEO microwave sounder from being implemented until now. The synthetic aperture approach has until recently not been feasible, due to the high power needed to operate the on-board high-speed massively parallel processing system required for 2D-synthesis, as well as a number of system and calibration obstacles. The development effort under way at JPL, with important contributions from the Goddard Space Flight Center and the University of Michigan, is intended to demonstrate the measurement concept and retire much of the technology risk. To that purpose a small ground based demo version of GeoSTAR is being constructed, which will be used to characterize system performance and test various calibration methods. This prototype development, which is being sponsored by NASA through its Instrument Incubator Program, will be completed in 2005. A GeoSTAR space mission can then be initiated. In parallel with the technology development, mission architecture studies are also under way in collaboration with the NOAA Office of System Development. In particular, the feasibility of incorporating GeoSTAR on the next generation of the geostationary weather satellites, GOES-R, is being closely examined. That would fill a long standing gap in the national weather monitoring capabilities.
A comment on non-chiral operators in SQCD and its dual

Abstract We match a few non-chiral operators in the electric and magnetic descriptions of SQCD, suggesting the first evidence of electric-magnetic duality outside the chiral ring. Algebraically, these non-chiral operators are a module of the chiral ring. Physically, the suggested correspondence essentially transforms certain electric gauge invariant composites containing the electric field strength into magnetic matter composites.
Heuristic algorithms for task assignment in distributed systems

Investigate the problem of static task assignment in distributed computing systems, i.e. given a set of k communicating tasks to be executed on a distributed system of n processors, to which processor should each task be assigned? The author proposes a family of heuristic algorithms for Stone's classic model of communicating tasks whose goal is the minimization of the total execution and communication costs incurred by an assignment. In addition, she augments this model to include interference costs which reflect the degree of incompatibility between two tasks. Whereas high communication costs serve as a force of attraction between tasks, causing them to be assigned to the same processor, interference costs serve as a force of repulsion between tasks, causing them to be distributed over many processors. The inclusion of interference costs in the model yields assignments with greater concurrency, thus overcoming the tendency of Stone's model to assign all tasks to one or a few processors. Simulation results show that the algorithms perform well and in particular, that the highly efficient Simple Greedy Algorithm performs almost as well as more complex heuristic algorithms. >
An Overview of Dry Etching Damage and Contamination Effects

Plasma or dry etching techniques, such as reactive ion etching, magnetron reactive ion etching, electron cyclotron resonance etching, ion beam etching, and plasma etching, can result in damage and contamination of the materials used in device structures and interconnects. The damage that can take place occurs because of ion bombardment, radiation‐induced bonding changes, and charge buildup. If not removed, damage can have effects which vary from gettering to creating traps in insulators and gap states in semiconductors. The contamination that can take place can have two forms: residue layers and permeation. The former are ultrathin layers of reaction products that can coat surfaces whereas the latter is the embedding or implantation, and perhaps subsequent diffusion, of impurities. These impurities can range from metals whose source is the processing chamber to hydrogen which is often found in the etch recipe or may even be found due to the presence of water in the processing chamber. If not removed, residues can interfere with subsequent processing such as oxidation and can cause series resistance in contacts. Impurities, if not removed, can have a range of effects from modifying carrier lifetimes to interfering with subsequent processing. Hydrogen, in particular, can affect materials in a number of ways including modifying doping activation.
Quark stars: features and findings

Under extreme conditions of temperature and/or density, quarks and gluons are expected to undergo a deconfinement phase transition. While this is an ephemeral phenomenon at the ultra-relativistic heavy-ion collider (BNL-RHIC), quark matter may exist naturally in the dense interior of neutron stars. Here, we present an appraisal of the possible phase structure of dense quark matter inside neutron stars, and the likelihood of its existence given the current status of neutron star observations. We conclude that quark matter inside neutron stars cannot be dismissed as a possibility, although recent observational evidence rules out most soft equations of state.
Intersecting line segments in parallel with an output-sensitive number of processors

An efficient parallel algorithm is given for constructing the arrangement of n line segments in the plane, i.e., the planar graph determined by the segment endpoints and intersections. This algorithm is efficient relative to three efficiency measures—it is an NC algorithm, it has a small time-processor product, and it is output-size sensitive. In particular, it runs in $O(\log n)$ time using $O(n\log n + k)$ processors, where k is the size of the output (which is $\Omega (n^2 )$ in the worst case). The algorithm does not receive the value of k as input, it determines it on-line. A method or solving an important special case of the segment arrangement problem is also shown, namely, when each input segment is parallel to one of the coordinate axes (i.e., iso-oriented). The algorithm for this problem runs in $O(\log n)$ time using an optimal $O(n + k / \log n)$ processors. The model of computation is the CREW PRAM model, where processor allocation must be explicit and global.