cssi/SciSciGPT-SciSciNet huggingface dataset:
Brane networks in AdS space

Abstract We present static solutions to Einstein's equations corresponding to the most general network of N orthogonal families of (2+ N )-branes in (4+ N )-dimensional AdS spacetimes. The bulk cosmological constant can take a different value in each cell enclosed by intersecting branes and the extra dimensions can be compact or noncompact. In each family of branes the inter-brane spacing is arbitrary. The extra dimensions may be any or all of the manifolds, R 1 , R 1 / Z 2 , S 1 and S 1 / Z 2 . Only when the extra dimensions are R 1 or/and R 1 / Z 2 , can networks consisting solely of positive tension branes be constructed. Such configurations may find application in models with localized gravity and symmetry breaking by shining.
Secretly Eccentric: The Giant Planet And Activity Cycle Of GJ 328

We announce the discovery of a ~2 Jupiter-mass planet in an eccentric 11?yr orbit around the K7/M0 dwarf GJ 328. Our result is based on 10?years of radial velocity (RV) data from the Hobby-Eberly and Harlan J. Smith telescopes at McDonald Observatory, and from the Keck Telescope at Mauna Kea. Our analysis of GJ 328's magnetic activity via the Na I D features reveals a long-period stellar activity cycle, which creates an additional signal in the star's RV curve with amplitude 6-10?m?s?1. After correcting for this stellar RV contribution, we see that the orbit of the planet is more eccentric than suggested by the raw RV data. GJ 328b is currently the most massive, longest-period planet discovered around a low-mass dwarf.
Li I AND K I SCATTER IN COOL PLEIADES DWARFS

We utilize high-resolution (R {approx} 60,000), high signal-to-noise ratio ({approx}100) spectroscopy of 17 cool Pleiades dwarfs to examine the confounding star-to-star scatter in the lambda6707 Li I line strengths in this young cluster. Our Pleiades, selected for their small projected rotational velocity and modest chromospheric emission, evince substantial scatter in the line strengths of lambda6707 Li I feature that is absent in the lambda7699 K I resonance line. The Li I scatter is not correlated with that in the high-excitation lambda7774 O I feature, and the magnitude of the former is greater than the latter despite the larger temperature sensitivity of the O I feature. These results suggest that systematic errors in line strength measurements due to blending, color (or color-based T{sub eff}) errors, or line formation effects related to an overlying chromosphere are not the principal source of Li I scatter in our stars. There do exist analytic spot models that can produce, via line formation effects, the observed Li scatter without introducing scatter in the K I line strengths or the color-magnitude diagram. However, these models predict factor of >=3 differences in abundances derived from the subordinate lambda6104 and resonance lambda6707 Li I features; we find no differencemore » in the abundances determined from these two features. These analytic spot models also predict CN line strengths significantly larger than we observe in our spectra. The simplest explanation of the Li, K, CN, and photometric data is that there must be a real abundance component to the Pleiades Li dispersion. We suggest that this real abundance component is the manifestation of relic differences in erstwhile pre-main-sequence Li burning caused by effects of surface activity on stellar structure. We discuss observational predictions of these effects, which may be related to other anomalous stellar phenomena.« less
A Note on the Determinants of AFDC Policies

The above results may be interpreted, as follows: political pressure to raise welfare (AFDC) levels is greater in those states where the population actually receiving welfare (AFDC) is greater and where unemployment among adult non-welfare recipients (who may expect to become welfare-eligible) is greater.
Latest results on the hot dense partonic matter at RHIC

At the Relativistic Heavy-Ion Collider (RHIC) collisions of heavy ions at nucleon-nucleon energies of 200 GeV appear to have created a new form of matter thought to be a deconfined state of the partons that ordinarily are bound in nucleons. We discuss the evidence that a thermalized partonic medium, usually called a Quark Gluon Plasma (QGP), has been produced. Then, we discuss the effect of this high-density medium on the production of jets and their pair correlations. Next, we look at direct photons as a clean electro-magnetic probe to constrain the initial hard scatterings. Finally, we review the developing picture for the effect of this medium on the production of open heavy quarks and on the screening by the QGP of heavy-quark bound states.
Optimal design and placement of pilot symbols for channel estimation

The problem of designing and placing pilot symbols for the estimation of frequency-selective random channels is considered. The channel is assumed to be a block-fading model with finite impulse response (FIR). For both single-input single-output (SISO) and multiple-input multiple-output (MIMO) channels, under the assumption of independent and identical distributed channel taps, the Cramer-Rao bound (CRB) on the mean square error (MSE) of semi-blind channel estimators is derived and minimized with respect to pilot symbols and their placement. It is shown that the optimal strategy is to place pilot symbols satisfying certain orthogonality condition in such a way that data and pilot symbols with higher power are in the middle of the packet. The results also indicate that the optimal pilot placements are independent of channel probability distribution. For constant modulus symbols, we show that the quasi-periodic placement and its generalization in the multiuser case turn out to be optimal. We further consider estimating channels with correlated taps and show that the previous placement strategy is also optimal among orthogonal pilot sequences.
Thermal rearrangements of 7,7-dihalo-trans-bicyclo[4.1.0]hept-3-enes

Abstract Derivatives of trans -bicyclo[4.1.0]hept-3-ene with chlorine and bromine substituents the 7 position were synthesized and their thermal rearrangements were examined. Thermolysis of the dichloride leads to the formation of the cis-fused isomer, while heating the dibromide results in ring-expanded products. Thermal rearrangement of the bromochloro derivative provided a mixture of ring-isomerized and ring-expanded products. The halogenated compounds are very labile relative to the unsubstituted molecule with rate accelerations on the order of 1000 or more at 120 °C. When solvents of widely varying polarity were employed, the isomerization rate coefficients for the halogenated derivatives vary by a factor of 1.0–3.2. Therefore, it is unlikely that these compounds rearrange via ionic intermediates.
Racemization of Meteoritic Amino Acids

Abstract Meteorites may have contributed amino acids to the prebiotic Earth, affecting the global ratio of right-handed to left-handed (D/L) molecules. We calculate D/L ratios for seven biological, α-hydrogen, protein amino acids over a variety of plausible parent body thermal histories, based on meteorite evidence and asteroid modeling. We show that amino acids in meteorites do not necessarily undergo complete racemization by the time they are recovered on Earth. If the mechanism of amino acid formation imposes some enantiomeric preference on the amino acids, a chiral signature can be retained through the entire history of the meteorite. Original enantiomeric excesses in meteorites such as Murchison, which have undergone apparently short and cool alteration scenarios, should have persisted to the present time. Of the seven amino acids for which relevant data are available, we expect glutamic acid, isoleucine, and valine, respectively, to be the most likely to retain an initial enantiomeric excess, and phenylalanine, aspartic acid, and alanine the least. Were the D/L ratio initially identical in each amino acid, final D/L ratios could be used to constrain the initial ratio and the thermal history experienced by the whole suite.
Why are Californian Farmers Adopting more (and Larger) Renewable Energy Operations

The paper examines the renewable energy adoption and system size determinants for Californian farmers. We utilize a double-hurdle methodology where system size is determined through a heteroskedastic ordered binary variable model for four size categories. Our results for system size show that determinants of technology adoption differ from size determinants. For example, environmental practices, Internet connection, and electricity price influence adoption, while, total value of production and acre value impact the size of the installed system. Surprisingly, the price of electricity bears no impact on the size category chosen. Renewable energy adoption and system size have been increasing over time, thus our insights about the interplay of the determinants for adoption and size choice, will assist policy formation.
The conformational composition of cis-1,4-dichloro-2-butene as determined by gas phase electron diffraction

Abstract The molecular structure of cis -1,4-dichloro-2-butene has been determined by gas phase electron diffraction at a nozzle temperature of 70°C. The molecules exist predominantly in a form where one of the carbonchlorine bonds nearly eclipses the CC bond while the other carbonchlorine bond rotates 114° away from the CC bond. The values of the principal distances ( r α ) and angles are: r (CH) av = 1.077(7) A, r (CC) = 1.351(6) A, r (CC) = 1.501(4) A, r (CCl) = 1.804(2) A, ∠ClCC = 112.0(5)°, ∠CCC = 125(1)° and τ(C 1 C 2 ) = 1(20)° and τ(C 4 C 3 ) = 114(13)°.
Effect of inflation on anisotropic cosmologies

We study the effects of anisotropic cosmologies on inflation. By properly formulating the field equations it is possible to show that any model that undergoes sufficient inflation will become isotropic on scales greater than the horizon today. Furthermore, we shall show that it takes a very long time for anisotropies to become visible in the observable part of the Universe. It is interesting to note that the time scale will be independent of the Bianchi model and of the initial anisotropy.
Fluoride release from fluoride varnishes under acidic conditions.

Objective: The aim was to investigate the in vitro fluoride release from fluoride varnishes under acidic conditions. Study design: Poly(methyl methacrylate) blocks (Perspex, n=3 per group) were painted with 80±5 mg fluoride varnish (n=10) and placed into artificial saliva for 30min. Then, blocks were placed into either 1% citric acid (pH 2.27) or 0.3% citric acid (pH 3.75) solutions (n=3 per solution and varnish) for 30min with the solutions being replaced every 5min. Saliva and acid solutions were analyzed for fluoride content. Data were analyzed using three-way ANOVA (varnish, solution, time). Results: The three-way interaction was significant (p>0.0001). Fluoride release and release patterns varied considerably between varnishes. Fluoride release in saliva varied by a factor of more than 10 between varnishes. Some varnishes (CavityShield, Nupro, ProFluorid, Vanish) showed higher fluoride release in saliva than during the first 5min of acid exposure, whereas other varnishes (Acclean, Enamel-Pro, MI Varn...
Optical Clock Distribution To Silicon Chips

Timing constraints for state-of-the-art very large scale integrated circuits (VLSI) in silicon are rapidly approaching communication limits available with layered two-dimensional metal and polysilicon wiring approaches. For such communication-limited systems, reliable clock distribution is a key concern. The range of finite differences in signal delays over clock wires of various lengths for large chips creates a timing skew that is significant when compared to the switching time of transistors in the circuit. The high bandwidth and three-dimensionality of imaging optical systems suggest that optical clock distribution systems have the potential to overcome the timing barriers presented by planar wiring. Clock signals can be holographically mapped to detector sites within small functional cells on a chip surface. Within each functional cell, the clock is distributed with negligible delays via surface wires, reducing skew effects to the variation in reaction times of the photodetectors on the chip. This paper includes the presentation of an optical clock distribution system assuming holographic mapping of beams from an off-chip optical source. Computer simulations of the electronic response of optical clock detection circuits in standard 4 µm CMOS technology have been performed.
Repeat endoscopic transsphenoidal surgery for acromegaly: remission and complications

Reported biochemical remission rates following surgical intervention for acromegaly range from 38 to 83 %. In patients not achieving surgical remission, few options remain, mostly limited to medical management and radiation therapy. There is debate over whether or not to offer reoperation to patients in whom surgical remission is not achieved with initial resection. Retrospective chart review was undertaken to determine all patients having acromegaly with persistently elevated GH and/or IGF-1 levels after initial pituitary adenoma resection, and who underwent reoperation using endoscopic endonasal approach at a single institution. Biochemical remission was defined as a postoperative GH level <1 ng/mL and a normal postoperative IGF-1 level in the absence of any medical therapy. In total, 14 patients underwent repeat surgical intervention for acromegaly via endoscopic transsphenoidal approach. Of the 14 patients, 8 (57 %) achieved biochemical remission following repeat surgical intervention. Lower preoperative GH levels were associated with greater chance of biochemical remission (P = 0.048). New endocrinopathies were seen in 2 patients (14 %), and both were transient diabetes insipidus. Meningitis occurred in 2 patients (14 %); both were aseptic meningitis with no sequelae. No mortality was encountered. Repeat surgical intervention for acromegaly via endoscopic transsphenoidal approach appears safe and effective. With no mortality and minimal morbidity, repeat surgical intervention via endoscopic transsphenoidal approach appears a reasonable option for these hard-to-treat patients and should be considered for patients in whom surgical remission is not achieved with initial surgery.
On the Error Term in Duke's Estimate for the Average Special Value of L-Functions

Let F be an orthonormal basis for weight 2 cusp forms of level N. We show that various weighted averages of special values L( f ⊗ χ,1) over f ∈ F are equal to 4πc+ O(N 1+ǫ ), where c is an explicit nonzero constant. A previous result of Duke gives an error term of O(N 1/2 log N).
Cross-population joint analysis of eQTLs: fine mapping and functional annotation.

Mapping expression quantitative trait loci (eQTLs) has been shown as a powerful tool to uncover the genetic underpinnings of many complex traits at molecular level. In this paper, we present an integrative analysis approach that leverages eQTL data collected from multiple population groups. In particular, our approach effectively identifies multiple independent cis-eQTL signals that are consistent across populations, accounting for population heterogeneity in allele frequencies and linkage disequilibrium patterns. Furthermore, by integrating genomic annotations, our analysis framework enables high-resolution functional analysis of eQTLs. We applied our statistical approach to analyze the GEUVADIS data consisting of samples from five population groups. From this analysis, we concluded that i) jointly analysis across population groups greatly improves the power of eQTL discovery and the resolution of fine mapping of causal eQTL ii) many genes harbor multiple independent eQTLs in their cis regions iii) genetic variants that disrupt transcription factor binding are significantly enriched in eQTLs (p-value = 4.93 × 10-22).
Boundary S matrix and boundary state in two-dimensional integrable quantum field theory

We study integrals of motion and factorizable S matrices in two-dimensional integrable field theory with boundary. We propose the "boundary cross-unitarity equation," which is the boundary analog of the crossing-symmetry condition of the "bulk" S matrix. We derive the boundary S matrices for the Ising field theory with boundary magnetic field and for the boundary sine–Gordon model.
Corrective lenses for high-redshift supernovae

Weak lensing of high-redshift Type Ia supernovae induces an external dispersion in their observed standard candle brightnesses, comparable in magnitude to the intrinsic dispersion for redshifts z > 1. The same matter fluctuations responsible for the magnification of distant supernovae also generate shear in the images of background galaxies. We investigate the possibility of using lensing shear maps constructed from galaxies surrounding the supernovae as a means of correcting the lensing-induced magnification dispersion. We find that a considerable fraction of the lensing dispersion derives from subarcminute scales, which are not probed by shear maps smoothed on arcminute scales. We thus find that weak-lensing shear maps will be of only limited value in reducing the weak-lensing magnification fluctuations of supernovae.
Positive commutators at the bottom of the spectrum

Abstract Bony and Hafner have recently obtained positive commutator estimates on the Laplacian in the low-energy limit on asymptotically Euclidean spaces; these estimates can be used to prove local energy decay estimates if the metric is non-trapping. We simplify the proof of the estimates of Bony–Hafner and generalize them to the setting of scattering manifolds (i.e. manifolds with large conic ends), by applying a sharp Poincare inequality. Our main result is the positive commutator estimate χ I ( H 2 Δ g ) i 2 [ H 2 Δ g , A ] χ I ( H 2 Δ g ) ⩾ C χ I ( H 2 Δ g ) 2 , where H ↑ ∞ is a large parameter, I is a compact interval in ( 0 , ∞ ) , and χ I its indicator function, and where A is a differential operator supported outside a compact set and equal to ( 1 / 2 ) ( r D r + ( r D r ) ∗ ) near infinity. The Laplacian can also be modified by the addition of a positive potential of sufficiently rapid decay—the same estimate then holds for the resulting Schrodinger operator.
FILL RADIUS AND THE FUNDAMENTAL GROUP

In this note we relate the geometric notion of fill radius with the fundamental group of the manifold. We prove: Suppose that a closed Riemannian manifold M satisfies the property that its universal cover has bounded fill radius. Then the fundamental group of M is virtually free. We explain the relevance of this theorem to some conjectures on positive isotropic curvature and 2-positive Ricci curvature.
Optimal load sharing in distributed real-time systems

Abstract The main goal of this paper is to derive an approximate, closed-form solution for the decentralized, dynamic load sharing (LS) problem treated in an earlier paper. In that paper, whenever the load state of a node changes from underloaded to fully loaded and vice versa, the node broadcasts this change to a set of nodes in its physical proximity, called a buddy set. An overloaded node can select, without probing other nodes, the first available node from its preferred list , an ordered buddy set. Preferred lists are so constructed that the probability of more than one overloaded node sending tasks to an underloaded node may be made very small. In hard real-time systems, the problem of scheduling periodic tasks to meet their deadlines has been studied extensively, but scheduling aperiodic tasks has been addressed far less, due mainly to their random arrivals. We show that the proposed LS method can be used to effectively handle aperiodic tasks in distributed real-time systems. The probability of missing task deadlines can be kept below a specified level by choosing appropriate threshold patterns and buddy set sizes which are derived from the approximate closed-form solution. Specifically, "optimal" threshold patterns and buddy set sizes are derived for different system loads by minimizing the communication overhead subject to a constraint of keeping the probability of missing task deadlines below any given level. (One can also derive optimal solutions by minimizing the probability of missing deadlines while keeping the communication overhead below a specified level.) Several examples are presented to demonstrate the power and utility of the proposed LS approach.
HOLOMORPHIC FUNCTIONS ON SUBSETS OF C

Let i be a C 1 curve in C containing 0; it becomes iµ after rotation by angle µ about 0. Suppose a C 1 function f can be extended holo- morphically to a neighborhood of each element of the family fiµg. We prove that under some conditions on i the function f is necessarily holomorphic in a neighborhood of the origin. In case i is a straight segment the well known Bochnak-Siciak Theorem gives such a proof for real analyticity. We also pro- vide several other results related to testing holomorphy property on a family of certain subsets of a domain in C.
SYNTHETIC STUDIES ON THE ERYTHRINA ALKALOIDS. PREPARATION OF ()-2-EPI-ERYTHRINITOL

Abstract The erythrina alkaloid, 1,3,4,6-tetrahydro-3,15,16-trimethoxyerythrinan-2-ol (2-epi-erythrinitol), has been synthesized by a sequence featuring a [1+4] vinyl isocyanate-isocyanide cycloaddition followed by an intramolecular Heck reaction for assembly of the erythrinan ring system.
The effect of different nutrient concentrations on the growth rate and nitrogen storage of watercress (Nasturtium officinale R. Br.)

The mechanisms that allow broadly distributed aquatic plants to inhabit variable resource environments are unclear, yet understanding these mechanisms is important because broad environmental tolerance is often linked to invasiveness in terrestrial and aquatic plants. In an experimental stream, we examined the effects of different nutrient concentrations on the growth rate, biomass, and foliar nutrient concentrations of a cosmopolitan and potentially invasive aquatic plant, Nasturtium officinale (R. Br.). Nasturtium seedlings were grown under six nutrient treatment levels ranging from 0.64 μm N:0.09 μm P to 1531 μm N:204.13 μm P, for 8 weeks. Absolute and relative growth rates, and biomass of seedlings increased along a gradient of increasing nutrient concentrations but the effect of nutrient concentration was dependent on growing time. Seedling biomass varied among nutrient treatments in weeks 4 through 8 of the experiment, but did not differ in week 2. By week 8, the two highest nutrient treatments had greater biomass than the two lowest nutrient treatments. Foliar nitrogen concentration increased, whereas carbon concentration and C:N ratios decreased in response to increasing nutrients. Nasturtium grows slowly in nutrient-poor conditions but rapidly increases its growth, biomass accrual, and nitrogen storage as conditions become nutrient-rich. The response of Nasturtium to enhanced nutrient conditions may indicate how aquatic nuisance species successfully invade and dominate plant communities in streams, where resources often vary both temporally and spatially.
Changes in the Nikkei 500: New Evidence for Downward Sloping Demand Curves for Stocks

This study investigates the price and trading volume effects of changes in the Nikkei 500. On average, prices increase (decrease) significantly for stocks added (deleted) with no significant post-event reversals. Trading volume, on average, increases significantly for both stocks added and deleted in the short run. In the long run, however, trading volume falls (rises) significantly for stocks added (deleted), contrary to previous findings. These results support the hypothesis of downward sloping demand curves for stocks and refute three competing hypotheses. Finally, the Nikkei 500 changes cause considerably less pronounced price changes than do the S&\amp;P 500 changes.
Acetylphosphonate as a Surrogate of Acetate or Acetamide in Organocatalyzed Enantioselective Aldol Reactions

Highly enantioselective aldol reactions of acetylphosphonates and activated carbonyl compounds was realized with cinchona alkaloid derived catalysts, in which the acetylphosphonate was directly used as an enolate precursor for the first time. The aldol product obtained was converted in situ to its corresponding ester or amide through methanolysis or aminolysis. The overall process may be viewed as formal highly enantioselective acetate or acetamide aldol reactions, which are very difficult to achieve directly with organocatalytic methods.
Are All Security Analysts Equal

We examine the extent to which security analysts are homogeneous in their effect on firm valuation as measured by Tobin's Q. Earlier research documents a significant and positive relation between analyst coverage and firm valuation. We identify three classes of equity analysts and examine their differential effect on firm valuation associated with their coverage and their information production. We find that equity analysts are not homogeneous in their effect on firm valuation. The presence of analysts at national securities firms have the strongest effect on firm valuation followed by analysts at regional securities firms and finally analysts at nonbrokerage, or research, firms. We attribute this result to the differential monitoring and information dissemination function rendered by the analysts. Information produced by analysts, however, does not share the same credibility. Specifically, we find brokerage firms' buy recommendations are discounted by the market and have a weak effect on firm valuation. The results can be supported by arguments that brokerage firm analysts' recommendations are contaminated by their firms' investment banking relations with corporations.
Non-relativistic effective theory of dark matter direct detection

Dark matter direct detection searches for signals coming from dark matter scattering against nuclei at a very low recoil energy scale ~ 10 keV. In this paper, a simple non-relativistic effective theory is constructed to describe interactions between dark matter and nuclei without referring to any underlying high energy models. It contains the minimal set of operators that will be tested by direct detection. The effective theory approach highlights the set of distinguishable recoil spectra that could arise from different theoretical models. If dark matter is discovered in the near future in direct detection experiments, a measurement of the shape of the recoil spectrum will provide valuable information on the underlying dynamics. We bound the coefficients of the operators in our non-relativistic effective theory by the null results of current dark matter direct detection experiments. We also discuss the mapping between the non-relativistic effective theory and field theory models or operators, including aspects of the matching of quark and gluon operators to nuclear form factors.
Tritium retention in tungsten exposed to intense fluxes of 100 eV tritons

Abstract Tungsten is a candidate material for the International Thermonuclear Experimental Reactor (ITER) as well as other future magnetic fusion energy devices. Tungsten is well suited for certain fusion applications in that it has a high threshold for sputtering as well as a very high melting point. As with all materials to be used on the inside of a tokamak or similar device, there is a need to know the behavior of hydrogen isotopes embedded in the material. With this need in mind, the Tritium Plasma Experiment (TPE) has been used to examine the retention of tritium in tungsten exposed to very high fluxes of 100 eV tritons. Both tungsten and tungsten containing 1% lanthanum oxide were used in these experiments. Measurements were performed over the temperature range of 423–973 K. After exposure to the tritium plasma, the samples were transferred to an outgassing system containing an ionization chamber for detection of the released tritium. The samples were outgassed using linear ramps from room temperature up to 1473 K. Unlike most other materials exposed to energetic tritium, the tritium retention in tungsten reaches a maximum at intermediate temperatures with low retention at both high and low temperatures. For the very high triton fluences used (>10 25 T/m 2 ), the fractional retention of the tritium was below 0.02% of the incident particles. This report presents not only the results of the tritium retention, but also includes the modeling of the results and the implication for ITER and other future fusion devices where tungsten is used.
Nanoskiving: A New Method To Produce Arrays of Nanostructures

This Account reviews nanoskiving--a new technique that combines thin-film deposition of metal on a topographically contoured substrate with sectioning using an ultramicrotome--as a method of fabricating nanostructures that could replace conventional top-down techniques in selected applications. Photolithography and scanning beam lithography, conventional top-down techniques to generate nanoscale structures and nanostructured materials, are useful, versatile, and highly developed, but they also have limitations: high capital and operating costs, limited availability of the facilities required to use them, an inability to fabricate structures on nonplanar surfaces, and restrictions on certain classes of materials. Nanoscience and nanotechnology would benefit from new, low-cost techniques to fabricate electrically and optically functional structures with dimensions of tens of nanometers, even if (or perhaps especially if) these techniques have a different range of application than does photolithography or scanning beam lithography. Nanoskiving provides a simple and convenient procedure to produce arrays of structures with cross-sectional dimensions in the 30-nm regime. The dimensions of the structures are determined by (i) the thickness of the deposited thin film (tens of nanometers), (ii) the topography (submicrometer, using soft lithography) of the surface onto which the thin film is deposited, and (iii) the thickness of the section cut by the microtome (> or =30 nm by ultramicrotomy). The ability to control the dimensions of nanostructures, combined with the ability to manipulate and position them, enables the fabrication of nanostructures with geometries that are difficult to prepare by other methods. The nanostructures produced by nanoskiving are embedded in a thin epoxy matrix. These epoxy slabs, although fragile, have sufficient mechanical strength to be manipulated and positioned; this mechanical integrity allows the nanostructures to be stacked in layers, draped over curved surfaces, and suspended across gaps, while retaining the in-plane geometry of the nanostructures embedded in the epoxy. After removal of the polymer matrix by plasma oxidation, these structures generate suspended and draped nanostructures and nanostructures on curved surfaces. Two classes of applications, in optics and in electronics, demonstrate the utility of nanostructures fabricated by nanoskiving. This technique will be of primary interest to researchers who wish to generate simple nanostructures, singly or in arrays, more simply and quickly than can be accomplished in the clean-room. It is easily accessible to those not trained in top-down procedures for fabrication and those with limited or no access to the equipment and facilities needed for photolithography or scanning-beam fabrication. This Account discusses a new fabrication method (nanoskiving) that produces arrays of metal nanostructures. The defining process in nanoskiving is cutting slabs from a polymeric matrix containing embedded, more extended metal structures.
Hard scattering in QCD with polarized beams

Abstract I show that factorization for hard processes in QCD is also valid when the detected particles are polarized, and that the proof of the theorem determines the operator formthe parton densities. Particular attention is given to the case of transversely polarized incoming hadrons.
Analysis and simulation of hypervelocity gouging impacts for a high speed sled test

Abstract An analysis and simulation of the gouging impact phenomenon which occurs at the Holloman Air Force Base High Speed Test Track (HHSTT) during hypervelocity impact testing is presented. Simulations of the sled/rail interactions were conducted using the hydrocode, CTH. These simulations utilize the most accurate and validated material models for the sled shoes (VascoMax 300) and rail (1080 steel) – which were recently developed. Sled shoe impacts with the rail were evaluated using various geometries possible in the field. The conditions leading to hypervelocity gouging were identified, as well as the condition which resulted in rail wear. The CTH simulations match results observed in the field extremely well. Recommendations are made, based on the latest material models and simulations, which should significantly reduce the occurrences of hypervelocity gouging at the HHSTT.
Selecting and Developing Advanced Alloys for Creep-Resistance for Microturbine Recuperator Applications

Recuperators are considered essential hardware to achieve the efficiencies desired for advanced microturbines. Compact recuperator technologies, including primary surface, plate and fin, and spiral, all require thin section materials that have high-temperature strength and corrosion resistance up to 750°C or above, and yet remain as low cost as possible. The effects of processing and microstructure on creep-rupture resistance at 750°C and 100 MPa were determined for a range of austenitic stainless alloys made into 0.1-mm foils. Two groups of alloys were identified with regard to improved creep resistance relative to type 347 stainless steel. Alloys with better creep-rupture resistance included alloys 120, 230, modified 803 arid alloy 740 (formerly thermic-alloy), while alloy 214 and 625 exhibited much better creep strength. Alloys 120 and modified 803 appeared to have the most cost-effective improvements in creep strength relative to type 347 stainless steel, and should be attractive for advanced microturbine recuperator applications.
Exceptional surgeries on knots with exceptional classes

We survey the aspects of classical combinatorial sutured manifold theory and show how they can be adapted to study exceptional Dehn fillings and 2-handle additions. As a consequence, we show that if a hyperbolic knot $$\beta $$ in a compact, orientable, hyperbolic 3-manifold, $$M$$ has the property that winding number and wrapping number are not equal with respect to a non-trivial class in $$H_2(M,\partial M)$$ , and then, with only a few possible exceptions, every 3-manifold $$M'$$ obtained by Dehn surgery on $$\beta $$ with surgery distance $$\Delta \ge 2$$ will be hyperbolic.
Mariner Jupiter/Saturn 1977 Navigation Strategy

This paper presents selected navigational aspects of the Mariner Jupiter/Saturn 1977 mission. Emphasis is given to the trajectory correction strategy. In addition to science return and propellant costs, specific considerations affecting the strategy include a large number of candidate trajectories, relatively close satellite flybys, use of trajectory correction maneuvers for trajectory shaping, and the requirement for an optical data type to achieve precision satellite encounters. Finally, important error sources and mission constraints are identified, and their impact on the strategy is discussed.
Deformations of Galois representations arising from degenerate extensions

Nigel Boston and Barry Mazur have shown how to determine the natural subspaces of certain S_3-extensions of the rationals, which they term "generic". We extend some of their results to another class of extensions, called "degenerate".
When Polarizations Generate

Let G be a reductive complex algebraic group and V a finite-dimensional G-module. From elements of the invariant algebra C[V]G we obtain, by polarization, elements of C[kV]G, where k ≥ 1 and kV denotes the direct sum of k copies of V. For G simple, our main result is the classification of the G-modules V and integers k ≥ 2 such that polarizations generate C[kV]G.
Accidental vaccinia: Report of two cases in infants, with eczema vaccinatum in one case

Summary The two cases of accidental vaccinia presented in this paper consist of (1)a case of uncomplicated inoculation of the cheek of a child 18 months old and (2) a severe case of eczema vaccinatum in a child 6 1/2 months old. Both children recovered. The complications of vaccination are many but occur infrequently. Probably the most common are benign exanthems and multiform eruptions. Accidental vaccinia may result from vaccination. One of the most serious complications of this is the development of eczema vaccinatum in an eczematous child. The relationship between eczema vaccinatum and Kaposi's varicelliform eruption is reviewed. The two cases reported indicate the dangers of accidental vaccinia and make clear the need for protection to prevent the accidental vaccination of nonimmunized individuals by a recently vaccinated person.
Using item-specific instructional information in achievement modeling

The problem of detecting instructional sensitivity (“item basis”) in test items is considered. An illustration is given which shows that for tests with many biased items, traditional item bias detection schemes give a very poor assessment of bias. A new method is proposed instead. This method extends item response theory (IRT) by including item-specific auxiliary measurement information related to opportunity-to-learn. Item-specific variation in measurement relations across students with varying opportunity-to-learn is allowed for.
Residual-Mean Solutions for the Antarctic Circumpolar Current and Its Associated Overturning Circulation

Abstract Residual-mean theory is applied to the streamwise-averaged Antarctic Circumpolar Current to arrive at a concise description of the processes that set up its stratification and meridional overturning circulation on an f plane. Simple solutions are found in which transfer by geostrophic eddies colludes with applied winds and buoyancy fluxes to determine the depth and stratification of the thermocline and the pattern of associated (residual) meridional overturning circulation.
Operator methods in physical optics

This paper is devoted to the exposition of operator algebraic methods that can be usefully applied to many areas of physical optics. These methods exploit the structural similarity between physical optics and quantum mechanics and make use of operator techniques widely used in quantum theory. We develop the basic approach here and illustrate its power by giving a compact derivation of the Fourier properties and the imaging properties of an ideal lens. We also use the operator approach to introduce and discuss operators and fields that are unaltered by passage through an optical system.
Decision-Making Process for Developing Urban Freight Consolidation Centers: Analysis with Experimental Economics

AbstractThe concept of freight consolidation center (FCC) has emerged in recent years. Although several case studies have indicated that FCCs are beneficial to the operation of urban transportation systems, the implementation of this concept has proven difficult because the construction and operation of a FCC involves the coordination of different, and conflicting, stakeholders. Unlike other traditional approaches, this paper investigates the FCC development issue using experimental economics. First, profit functions are defined for involved stakeholders; based on those profit functions, four players—carriers, operators, government, and residents—bid on rent, financial incentives, and wages to maximize their own profits. Eight scenarios are analyzed and compared to determine potential influential factors and appropriate conditions for FCC decision making. Results show that public–private partnership lowers rent and increases wages, which leads to higher carrier, operator, and resident profits. A central l...
Allergic fungal sinusitis with cranial base erosion.

Background Allergic fungal sinusitis (AFS) usually follows a slow, nonaggressive course. However, massive bone destruction can occur, with extension of the disease process outside of the confines of the sinuses. Methods Our series of 28 cases of AFS was reviewed. We identified 6 cases of AFS with definite radiographic evidence of skull base erosion. Results Histologic diagnostic criteria for AFS were present in all 6 cases. All patients were managed with surgery, most recently conservative endoscopic surgery. An earlier patient underwent dural resection. Antibiotics were used in all patients, but no antifungal agents were administered. No patient has had a permanent neurologic complication, although one was seen with abducens palsy. There have been no cerebrospinal fluid (CSF) leaks. All 6 cases also had orbital bone erosion, but none has had permanent ophthalmologic sequelae. All patients were initially suspected to have a neoplastic disease. Conclusions We propose a new diagnostic entity, “skull base allergic fungal sinusitis” (SBAFS), which incorporates the histologic diagnostic criteria of AFS with the computed tomographic (CT) criteria of bone erosion. Biopsy is necessary to rule out invasive fungus or tumor. Otolaryngologists, ophthalmologists, and neurosurgeons should be familiar with SBAFS so that systemic antifungal agents, craniotomy, and dural resection—which might initially appear necessary—can be avoided. Endoscopic surgical debridement and drainage combined with topical steroids can lead to resolution of disease, even in the presence of marked bone erosion and cranial neuropathy. © 1996 John Wiley & Sons, Inc.
Kinetic and Thermodynamic Approaches for the Efficient Formation of Mechanical Bonds

Among the growing collection of molecular systems under consideration for nanoscale device applications, mechanically interlocked compounds derived from electrochemically switchable bistable [2]rotaxanes and [2]catenanes show great promise. These systems demonstrate dynamic, relative movements between their components, such as shuttling and circumrotation, enabling them to serve as stimuli-responsive switches operated via reversible, electrochemical oxidation−reduction rather than through the addition of chemical reagents. Investigations into these systems have been intense for a number of years, yet limitations associated with their synthesis have hindered incorporation of their mechanical bonds into more complex architectures and functional materials. We have recently addressed this challenge by developing new template-directed synthetic protocols, operating under both kinetic and thermodynamic control, for the preparation of bistable rotaxanes and catenanes. These methodologies are compatible with the ...
Scaled telerobotic control of a manipulator in real time with laser assistance for ADL tasks

Abstract In this paper we present a novel concept of shared autonomous and teleoperation control of a remote manipulator with a laser-based assistance in a hard real-time environment for people with disabilities to perform activities of daily living (ADL). The laser pointer enables the user to make high-level decisions, such as target object selection, and it enables the system to generate a trajectories and virtual constraints to be used for autonomous motion or scaled teleoperation. Autonomous, position-teleoperation and velocity-teleoperation control methods have been implemented in the control code. Scaling and virtual fixtures have been used in the teleoperation based control depending on the user preference. A real-time QNX operating system has been used to control a PUMA 560 robotic arm using a Phantom Omni master through a TCP/IP port. A SICK laser range finder was used to for the telerobotic control. The system was implemented with different control modes, and three healthy human subjects were trained to use the system for a pick-and-place task. Data were collected and presented for different control modes, and a comparison between these modes based on the time to complete the task was presented.
Repeated exposure of adult rats to Aroclor 1254 causes brain region-specific changes in intracellular Ca2+ buffering and protein kinase C activity in the absence of changes in tyrosine hydroxylase.

Abstract Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants, some of which may be neurotoxic.In vitrostudies from this laboratory indicated that noncoplanar PCBs perturbed intracellular signal transduction mechanisms including Ca2+homeostasis, receptor-mediated inositol phosphate production, and translocation of protein kinase C (PKC). In the present study, we examined the effects of PCBsin vivoby dosing adult male Long–Evans rats orally with Aroclor 1254 (0, 10, or 30 mg/kg/day; 5 days/week for 4 weeks) in corn oil. At 24 h after the last dose, rats were tested for motor activity in a photocell device for 30 min. Immediately, the rats were euthanized, blood was collected for thyroid hormone analysis, and brains were removed, dissected into regions (cerebellum, frontal cortex, and striatum), and subcellular fractions were obtained for neurochemical analysis. Following Aroclor 1254 treatment, body weight gain in the high-dose group was significantly lower than the control and low-dose groups. Horizontal motor activity was significantly lower in rats dosed with 30 mg/kg Aroclor 1254. Ca2+buffering by microsomes was significantly lower in all three brain regions from the 30 mg/kg group. In the same dose group, mitochondrial Ca2+buffering was affected in cerebellum but not in cortex or striatum. Similarly, total cerebellar PKC activity was decreased significantly while membrane-bound PKC activity was significantly elevated at 10 and 30 mg/kg. PKC activity was not altered either in cortex or the striatum. Neurotransmitter levels in striatum or cortex were slightly altered in PCB-exposed rats compared to controls. Furthermore, repeated oral administration of Aroclor 1254 to rats did not significantly alter forebrain tyrosine hydroxylase immunoreactivity or enzymatic activity. Circulating T4(total and free) concentrations were severely depressed at both doses in Aroclor 1254-exposed rats compared to control rats, suggesting a severe hypothyroid state. These results indicate that (1)in vivoexposure to a PCB mixture can produce changes in second messenger systems that are similar to those observed afterin vitroexposure of neuronal cell cultures; (2) second messenger systems seem to be more sensitive than alterations in neurotransmitter levels or tyrosine hydroxylase involved in dopamine synthesis during repeated exposure to PCBs; and (3) the observed motor activity changes were independent of changes in striatal dopamine levels.
Instrument requirements for a next generation 1km resolution hyperspectral imaging spectrometer

The combined performance of the Atmospheric Infrared Sounder (AIRS) and the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Earth Observing System (EOS) Aqua spacecraft is possible in a single instrument with today's technology. Combining the capability allows better accuracy and resolution of products produced by both instruments. This paper describes the top level requirements expected from such an instrument, the types of products anticipated, and discusses technology readiness.
Double implementation in economies with production technologies unknown to the designer

This paper considers double implementation of Walrasian allocations and Lindahl allocations in Nash and strong Nash equilibria for both private and public goods economies when preferences, initial endowments, production technologies, and coalition patterns are all unknown to the designer. It will be noted that the mechanisms presented here are feasible and continuous. In addition, unlike most mechanisms proposed in the literature, our mechanism works not only for three or more agents, but also for two-agent economies, and thus it is a unified mechanism which is irrespective of the number of agents.