cssi/SciSciGPT-SciSciNet huggingface dataset:
Probing Interstellar Dust with Space-based Coronagraphs

We show that space-based telescopes such as the proposed Terrestrial Planet Finder Coronagraph will be able to detect the light scattered by the interstellar grains along lines of sight passing near stars in our Galaxy. The relative flux of the scattered light within 1 -->'' of a star at 100 pc in a uniform interstellar medium of 0.1 H atoms cm−3 is about 10−7. The halo increases in strength with the distance to the star and is unlikely to limit the coronagraphic detection of planets around the nearest stars. Grains passing within 100 AU of Sun-like stars are deflected by radiation, gravity, and magnetic forces, leading to features in the scattered light that can potentially reveal the strength of the stellar wind, the orientation of the stellar magnetic field and the relative motion between the star and the surrounding interstellar medium.
White dwarf models for type I supernovae and quiet supernovae, and presupernova evolution

Supernova mechanisms in accreting white dwarfs (WDs) are presented, i.e., the carbon deflagration as a plausible mechanism for producing Type I supernovae and electron captures to form quiet supernovae leaving neutron stars. These outcomes depend on accretion rate of helium, initial mass and composition of the WD. The various types of hydrogen shell-burning in the presupernova stage are also discussed.
Comment on "Generation of electromagnetic pulses from plasma channels induced by femtosecond light strings".

In a recent Letter, Cheng et al. calculated/predicted several new effects: that (a) fraction of the short laser pulse momentum can be imparted to plasma electrons via collisional damping of the laser, thereby exciting a long-lived (longer than an oscillation period) plasma wave, which (b) gives rise to a spatially uniform dipole moment of a plasma, which (c) emits far-field narrow-band radiation at the plasma frequency omega subscript ''p'' over the recombination time of the plasma. We claim that the calculation of the effect (a) is in error and the predicted effects (b,c) do not occur as described. In fact, predicted narrow-band emission at omega subscript ''p'' would not occur even if the momentum transfer and the dipole excitation were calculated correctly.
Catalytic asymmetric intramolecular aminopalladation: enantioselective synthesis of vinyl-substituted 2-oxazolidinones, 2-imidazolidinones, and 2-pyrrolidinones.

A new catalytic asymmetric synthesis of five-membered nitrogen heterocycles is reported. This synthesis employs ferrocenyloxazoline palladacycles (FOP trifluoroacetate catalysts) 2 and 4 and proceeds by a catalytic cycle involving Pd(II) intermediates. For example, prochiral (Z)-4-acetoxy-2-buten-1-ols are condensed with an arylsulfonyl isocyanate and the derived allylic N-arylsulfonylcarbamates cyclize in situ upon addition of 0.5−5 mol % of 2 or 4 to form 4-vinyloxazolidin-2-ones 6, 13, and 15 in high yield and 89−99% ee. The related 2-pyrrolidinone 19 and 2-imidazolidinone 18 are prepared in similar fashion. Pyrrolidinone 19 can be converted in two steps to the unnatural enantiomer of the GABA inhibitor vigabatrin 20.
Quantum mechanics of electrons in crystals with graded composition.

Abstract : We construct the effective Hamiltonian describing the motion of electrons in compositionally graded crystals which is valid throughout a given energy band and part way into the gaps. The effective Hamiltonian, constructed from the band structures of uniform crystals, also includes the effects of a slowly varying applied scalar potential U(r). Near the edges of a nondegenerate band, this effective Hamiltonian reduces to an effective mass Hamiltonian with position dependent mass (one of several forms previously appearing in the literature): H sub eff = 1/2 pi(1/m*(r)) sub ij pj + Epsilon(r) + U(r), where Epsilon(r) is the energy of the band edge as a function of position. The analogous effective mass Hamiltonian for degenerate bands is also derived. Next, we examine more general states-not restricted to the vicinity of a band edge in crystals with composition and applied potential variation in one direction. We obtain a WKB-type solution for the envelope functions, as well as the appropriate turning point connection rules.
REVISITING THE SCALING RELATIONS OF BLACK HOLE MASSES AND HOST GALAXY PROPERTIES

New kinematic data and modeling efforts in the past few years have substantially expanded and revised dynamical measurements of black hole masses (M ?) at the centers of nearby galaxies. Here we compile an updated sample of 72 black holes and their host galaxies, and present revised scaling relations between M ? and stellar velocity dispersion (?), V-band luminosity (L), and bulge stellar mass (M bulge), for different galaxy subsamples. Our best-fitting power-law relations for the full galaxy sample are log10(M ?) = 8.32 + 5.64log10(?/200 km s?1), log10(M ?) = 9.23 + 1.11log10(L/1011 L ?), and log10(M ?) = 8.46 + 1.05log10(M bulge/1011 M ?). A log-quadratic fit to the M ?-? relation with an additional term of ?2 [log10(?/200 km s?1)]2 gives ?2 = 1.68 ? 1.82 and does not decrease the intrinsic scatter in M ?. Including 92 additional upper limits on M ? does not change the slope of the M ?-? relation. When the early- and late-type galaxies are fit separately, we obtain similar slopes of 5.20 and 5.06 for the M ?-? relation but significantly different intercepts?M ? in early-type galaxies are about two times higher than in late types at a given sigma. Within early-type galaxies, our fits to M ?(?) give M ? that is about two times higher in galaxies with central core profiles than those with central power-law profiles. Our M ?-L and M ?-M bulge relations for early-type galaxies are similar to those from earlier compilations, and core and power-law galaxies yield similar L- and M bulge-based predictions for M ?. When the conventional quadrature method is used to determine the intrinsic scatter in M ?, our data set shows weak evidence for increased scatter at M bulge < 1011 M ? or LV < 1010.3 L ?, while the scatter stays constant for 1011 < M bulge < 1012.3 M ? and 1010.3 < LV < 1011.5 L ?. A Bayesian analysis indicates that a larger sample of M ? measurements would be needed to detect any statistically significant trend in the scatter with galaxy properties.
Beyond nature's chiral pool: Enantioselective catalysis in industry

Enantioselective catalysts produce organic compounds in enantiomerically enriched form. They are highly efficient tools for the synthesis of biologically active materials, such as pharmaceuticals and crop-protection chemicals, in which enantiomeric purity can be critical. The design of chiral ligands is the key to developing new enantioselective catalysts. Three unusual families of ligands have been used to develop practical technology for enantioselective hydrocyanation of olefins, ring-opening of epoxides, and hydrogenation of various compounds.
Universality of transition temperatures in families of copper-oxide superconductors: interlayer tunneling redux

We revisit the interlayer tunneling theory of high temperature superconductors and formulate it as a mechanism by which the striking systematics of the transition temperature within a given homologous series can be understood. We pay attention not only to the enhancement of pairing, as was originally suggested, but also to the role of competing order parameters that tend to suppress superconductivity, and to the charge imbalance between inequivalent outer and inner CuO 2 planes in a unit cell. Calculations based on a generalized Ginzburg-Landau theory yield results that bear robust and remarkable resemblance to experimental observations.
Heterogeneous photocatalytic oxidation of gas-phase organics for air purification: Acetone, 1-butanol, butyraldehyde, formaldehyde, and m-xylene oxidation

Abstract Photocatalyzed degradations of trace levels of various oxygenates and an aromatic in air were carried out using near-UV-illuminated titanium dioxide (anatase) powder. The initial rates of degradation for acetone, 1-butanol, formaldehyde, and m-xylene were well described by Langmuir-Hinshelwood rate forms. No reaction intermediates were detected for acetone oxidation at conversions of 5–20%. Butyraldehyde was the main product of 1-butanol oxidation for conversions of 20–30%. The influence of 5% water (simulating partial humidification) in the feedstream varied strongly: water vapor inhibited acetone oxidation, but had no influence on the 1-butanol conversion rate. m-Xylene conversion was enhanced by trace water addition, but inhibited at higher water levels. Some catalyst deactivation was detected between 1-butanol runs; the activity could be easily recovered by illuminating the catalyst in fresh air. Formaldehyde was also successfully oxidized. These results, taken together with earlier literature citations for photocatalyzed total oxidation of methane, ethane, trichloroethylene (but see (27)), toluene, and a very recent report for oxidation of odor compounds, indicate a favorable technical potential for photocatalyzed treatment of air in order to degrade and remove all major classes of oxidizable air contaminants.
Nonparametric hazard estimation with time-varying discrete covariates

Abstract The traditional one-sample nonparametric estimator of the cumulative hazard function is extended to allow for time-varying discrete covariates. A proof for the consistency and asymptotic normality of the estimator, as well as a derivation of the asymptotic standard error, is provided. Numerical results show that the estimator performs reasonably well.
Second generation synthesis of the quartromicin spirotetronic acid subunits via a Claisen rearrangement-intramolecular aldol sequence

Abstract Spirotetronate 4 needed for the assignment of stereochemistry to the quartromicins has been synthesized from 9 and 10 by a route featuring a Claisen rearrangement and intramolecular aldol reaction to establish the stereochemistry of the carbon framework.
Backscattering of secondary electrons to the cathode in the oblique electric field in dielectric barrier discharge systems

In dielectric barrier discharge systems, where the cathode is covered with the dielectric layer, electric field lines may cross the cathode surface at an oblique angle θ. The secondary electrons emitted from this surface either return to the cathode due to collisions with atoms of the background gas or escape from the cathode vicinity. Using the two-term approximation to the Boltzmann equation for electrons, we have found that, for Ramsauer gases, the electron escape factor fes as a function of the angle θ unexpectedly exhibits non-monotonic behaviour. Monte Carlo simulations of backscattering of electrons performed for xenon and argon have confirmed the theoretical results and shown similar trends for non-Ramsauer gases.
Fluctuating Strings in the Universal Confining String Theory and Gluodynamics

An effective string theory emerging from the bilocal approximation to the method of vacuum correlators in gluodynamics is shown to be well-described by the 4D theory of the massive Abelian Kalb–Ramond field interacting with the string, which is known to be the low energy limit of the universal confining string theory. This correspondence follows from the agreement of the behavior of the coefficient functions, which parametrize the gauge-invariant correlator of two gluonic field strength tensors, known from the lattice data, with their values obtained from the propagator of the Kalb–Ramond field. We discuss this correspondence in several aspects and demonstrate that the mass of the Kalb–Ramond field in this approach plays the role of the inverse correlation length of the vacuum, so that in the massless limit string picture disappears. Next, we apply the background field method, known in the theory of nonlinear sigma models, to obtain the action, which is quadratic in quantum fluctuations around a given (e....
Nongeometric flux compactifications

We investigate a simple class of type-II string compactifications which incorporate nongeometric ``fluxes'' in addition to ``geometric flux'' and the usual H-field and R-R fluxes. These compactifications are nongeometric analogues of the twisted torus. We develop T-duality rules for NS-NS geometric and nongeometric fluxes, which we use to construct a superpotential for the dimensionally reduced four-dimensional theory. The resulting structure is invariant under T-duality, so that the distribution of vacua in the IIA and IIB theories is identical when nongeometric fluxes are included. This gives a concrete framework in which to investigate the possibility that generic string compactifications may be nongeometric in any duality frame. The framework developed in this paper also provides some concrete hints for how mirror symmetry can be generalized to compactifications with arbitrary H-flux, whose mirrors are generically nongeometric.
Homotopy classes that are trivial mod F

IfF is a collection of topological spaces, then a homotopy class in (X;Y ) is called F -trivial if =0:( A;X)! (A;Y ) for all A2F. In this paper we study the collection ZF (X;Y )o f all F - trivial homotopy classes in (X;Y )w hen F = S, the collection of spheres, F = M, the collection of Moore spaces, and F = , the collection of suspensions. Clearly Z(X;Y )ZM(X;Y )ZS(X;Y ); and we nd examples of nite complexes X and Y for which these inclu- sions are strict. We are also interested in ZF(X )= ZF (X;X), which under composition has the structure of a semigroup with zero. We show that if X is a nite dimensional complex and F =S , M or , then the semigroup ZF (X) is nilpotent. More precisely, the nilpotency of ZF (X) is bounded above by theF -killing length of X , a new numerical invariant which equals the number of steps it takes to make X contractible by successively attach- ing cones on wedges of spaces in F , and this in turn is bounded above by the F -cone length of X. We then calculate or estimate the nilpotency of ZF (X )w hen F = S , Mor for the following classes of spaces: (1) projective spaces (2) certain Lie groups such as SU(n )a ndSp(n). The paper concludes with several open problems. AMS Classication 55Q05; 55P65, 55P45, 55M30
Tissue distribution and developmental expression of type XVI collagen in the mouse

Abstract The expression of a recently identified collagen, α1(XVI), in adult mouse tissue and developing mouse embryo was examined by immunohistochemistry and in situ hybridization. A polyclonal antiserum was raised against a recombinant fusion protein, which contained a segment of 161 amino acids in the N-terminal noncollagenous domain of the human α1(XVI) collagen. Immunoprecipitation of metabolically labelled human or mouse fibroblast cell lysates with this antibody revealed a major, bacterial collagenase sensitive polypeptide of ∼210 kDa. The size agrees with the prediction from the full-length cDNA. Immunofluorescence examination of adult mouse tissues using the affinity purified antibody revealed a rather broad distribution of the protein. The heart, kidney, intestine, ovary, testis, eye, arterial walls and smooth muscles all exhibited significant levels of expression, while the skeletal muscle, lung and brain showed very restricted and low signals. During development, no significant expression of the mRNA or protein was observed in embryo of day 8 of gestation, but strong signals was detected in placental trophoblasts. Expression in embryos was detectable first after day 11 of gestation with weak positive signals appearing in the heart. In later stages of development, stronger RNA hybridizations were observed in a variety of tissues, particularly in atrial and ventricular walls of the developing heart, spinal root neural fibers and skin. These data demonstrate that type XVI collagen represents another collagenous component widely distributed in the extracellular matrix and may contribute to the structural integrity of various tissues.
Cryogenic transfer options for exploration missions

The literature of in-space cryogenic transfer is reviewed in order to propose transportation concepts to support the Space Exploration Initiative (SEI). Forty-nine references are listed and key findings are synopsized. An assessment of the current maturity of cryogenic transfer system technology is made. Although the settled transfer technique is the most mature technology, the No-Vent Fill technology is maturing rapidly. Future options for development of cryogenic transfer technology are also discussed.
Intelligent structures for aerospace - A technology overview and assessment

HIS article presents an overview and assessment of the technology leading to the development of intelligent structures. Intelligent structures are those which incorporate actuators and sensors that are highly integrated into the structure and have structural functionality, as well as highly integrated control logic, signal conditioning, and power amplification electronics. Such actuating, sensing, and signal processing elements are incorporated into a structure for the purpose of influencing its states or characteristics, be they mechanical, thermal, optical, chemical, electrical, or magnetic. For example, a mechanically intelligent structure is capable of altering both its mechanical states (its position or velocity) or its mechanical characteristics (its stiffness or damping). An optically intelligent structure could, for example, change color to match its background.17 Definition of Intelligent Structures Intelligent structures are a subset of a much larger field of research, as shown in Fig. I.123 Those structures which have actuators distributed throughout are defined as adaptive or, alternatively, actuated. Classical examples of such mechanically adaptive structures are conventional aircraft wings with articulated leading- and trailing-edge control surfaces and robotic systems with articulated manipulators and end effectors. More advanced examples currently in research include highly articulated adaptive space cranes. Structures which have sensors distributed throughout are a subset referred to as sensory. These structures have sensors which might detect displacements, strains or other mechanical states or properties, electromagnetic states or properties, temperature or heat flow, or the presence or accumulation of damage. Applications of this technology might include damage detection in long life structures, or embedded or conformal RF antennas within a structure. The overlap structures which contain both actuators and sensors (implicitly linked by closed-loop control) are referred to as controlled structures. Any structure whose properties or states can be influenced by the presence of a closed-loop control system is included in this category. A subset of controlled structures are active structures, distinguished from controlled structures by highly distributed actuators which have structural functionality and are part of the load bearing system.
Beating the adaptive bandit with high probability

We provide a principled way of proving O(√T) high-probability guarantees for partial-information (bandit) problems over arbitrary convex decision sets. First, we prove a regret guarantee for the full-information problem in terms of “local” norms, both for entropy and self-concordant barrier regularization, unifying these methods. Given one of such algorithms as a black-box, we can convert a bandit problem into a full-information problem using a sampling scheme. The main result states that a high-probability O(√T) bound holds whenever the black-box, the sampling scheme, and the estimates of missing information satisfy a number of conditions, which are relatively easy to check. At the heart of the method is a construction of linear upper bounds on confidence intervals. As applications of the main result, we provide the first known efficient algorithm for the sphere with an O(√T) high-probability bound. We also derive the result for the n-simplex, improving the O(√nT log(nT)) bound of Auer et al [3] by replacing the log T term with log log T and closing the gap to the lower bound of Ω(√nT). While O(√T) high-probability bounds should hold for general decision sets through our main result, construction of linear upper bounds depends on the particular geometry of the set; we believe that the sphere example already exhibits the necessary ingredients. The guarantees we obtain hold for adaptive adversaries (unlike the in-expectation results of [1]) and the algorithms are efficient, given that the linear upper bounds on confidence can be computed.
Comparison of biparental and melting pot methods of crossing sugarcane in Hawaii

Sugarcane (Saccharum hybrid spp.) breeders at the Hawaiian Sugar Planters’ Association used biparental and melting pot (modified polycross) crossing methods concurrently from 1935 to 1985. While the annual effort expended to make biparental crosses exceeded the effort to make melting pot crosses over this 50-year period, annual viable seed yield from biparental crosses was usually less than 15% of that from melting pot crosses and hence, the numbers of seedlings planted to the field from those crosses usually accounted for less than 20% of the total seedling population. In 1985, nine of the 10 sugarcane cultivars listed in Hawaii’s variety census originated from melting pot crosses; only one originated from a biparental cross. In the face of a shrinking sugar industry in Hawaii and a smaller work force in the breeding program, the decision was made in 1985 to rely primarily on melting pot crosses for the production of commercial cultivars. From 1985 to 2005, twelve additional clones that were bred prior to 1985 eventually attained “commercial cultivar” status by exceeding 1% of the total cane growing area. All twelve originated from melting pot crosses. Over the 50-year period that the two crossing methods were used, the melting pot method proved to be more labour efficient and ultimately contributed more than the biparental crossing procedure toward the development of new commercial cultivars for the Hawaiian sugar industry. From 1985 forward, the biparental crossing method was used more for introgressing desired traits from exotic germplasm than for the development of commercial cultivars.
Shrinkage Estimation of Price and Promotional Elasticities: Seemingly Unrelated Equations

Abstract Consider the problem where a retailer or manufacturer wants to estimate product price and promotional elasticities based on supermarket scanner data. Classical linear modeling suffers from the following aggregation dilemma. Price and promotional elasticities appear to vary considerably among chains and brands so that one overall model is too restrictive. Alternatively, the use of a different model for each chain and brand leads to noisy and often nonsensical estimates of separate elasticities because of excessive data variation. To resolve this dilemma, shrinkage estimation procedures are proposed. By borrowing strength across chains and brands, these procedures reduce variability while providing flexibility that allows for separate elasticity estimates. Application of these procedures to a large data set yields not only more reasonable model estimates but also improved predictive power.
Room temperature syntheses of entirely diverse substituted β-fluorofurans

Synthesis of highly substituted 3-fluorofurans is reported. The sequence began with preparation of tert-butyldimethylsilyl alk-1-en-3-yn-1-yl ethers from 1,4-disubstituted alk-3-yn-1-ones. Subsequent fluorination of alkenynyl silyl ethers with Selectfluor gave 2-fluoroalk-3-yn-1-ones in almost quantitative yield. Subsequent 5-endo-dig cyclizations using chlorotriphenylphosphine gold(I)/silver trifluoromethanesulfonate (5/5 mol%), N-bromo- or N-iodosuccinimide and gold(I) chloride/zinc bromide (5/20 mol%), all at room temperature, provided a facile method for the generation of substituted 3-fluoro-, 3-bromo-4-fluoro-, and 3-fluoro-4-iodofurans in good yields. Also, 2,2-difluoroalk-3-yn-1-ones were prepared by fluorination of alk-3-yn-1-ones under organocatalytic conditions. The structures of (Z)-tert-butyldimethylsilyl but-1-en-3-yn-1-yl ether, 3-bromo-4-fluorofuran, and 3-fluoro-4-(phenylethynyl)furan were confirmed by X-ray crystallography.
Recognizing s-star polygons

Abstract We consider the problem of recognizing star-polygons under staircase visibility (s-visibility). We show that the s-visibilitypolygon from a point inside a simple orthogonal polygon of n sides can be computed in O(n) time. When the polygon contains holes the algorithm runs in O(n log n) time, which we prove to be optimal by linear time reduction from sorting. We present an algorithm for computing the s-kernel of a polygon in O(n) time for simple orthogonal polygons and in O(n2) time for orthogonal polygons with holes; both complexities are optimal in the worst case. Finally, we report the main result of this paper: we show that even though the s-kernel of a polygon with holes may have Ω(n 2 ) components it is possible to recognize such polygons in O(n log n) time.
Traces in symmetric monoidal categories

Abstract The purpose of this expository note is to describe duality and trace in a symmetric monoidal category, along with important properties (including naturality and functoriality), and to give as many examples as possible. Among other things, this note is intended as background for the generalizations to the context of bicategories and indexed monoidal categories.
The Dahlia mosaic virus gene VI product N-terminal region is involved in self-association.

Abstract The genome of the floriculture pathogen Dahlia mosaic caulimovirus (DMV) encodes six open reading frames. Generally, caulimovirus gene VI products (P6s) are thought to be multifunctional proteins required for viral infection and it is likely that self-association is required for some of these functions. In this study, yeast two-hybrid and maltose binding protein (MBP) pull-down assays indicated that full-length DMV P6 specifically self-associates. Further analyses indicated that only the DMV P6 N-terminal region, consisting of 115 amino acids, interacts with full-length P6 and with itself. This distinguishes the DMV P6 from its Cauliflower mosaic virus counterpart, which contains four regions involved in self-association. Thus, our results suggest that each caulimovirus P6 may possess a unique pattern of protein–protein interactions. Bioinformatic tools identified a putative nuclear exclusion signal located between amino acid residues 10–20, suggesting another possible function for the P6 N-terminal region.
On the robustness of output feedback control methods to modeling errors

Singular perturbation analysis is employed to study the robustness of output feedback control schemes for linear time-invariant systems. The effect of designing the control strategy using a model that neglects unknown parasitic elements is considered. It is shown that such a strategy may, in general, be destabilizing even when the neglected modes are asymptotically stable. Special structures that will not permit this situation and will guarantee asymptotic stability are illustrated.
A Computer Model of Magnetic Saturation and Hysteresis for Use on SPICE2

Magnetic saturation and hysteresis are simulated on SPICE2 using a model containing two nonlinear controlled sources. The model is applied to inductors and transformers made from a variety of core materials, and procedures are given for determining the model parameters directly from magnetic core catalog data. Four examples of circuit applications are given: a saturating instrumentation transformer, a saturating snubber inductor, a ferroresonant regulator transformer, and a Royer saturation oscillator.
Reagent-controlled asymmetric homologation of boronic esters by enantioenriched main-group chiral carbenoids.

Putative enantioenriched carbenoid species, (R)-1-chloro-2-phenylethylmagnesium chloride (9) and (S)-1-chloro-2-phenylethyllithium (26), generated in situ by sulfoxide ligand exchange from (−)-(RS,R)-1-chloro-2-phenylethyl p-tolyl sulfoxide (8), effected the stereocontrolled homologation of boronic esters. sec-Alcohols derived from the product boronates by oxidation with basic hydrogen peroxide exhibited % ee closely approaching that of sulfoxide 8 in examples employing Li-carbenoid 26.
Intramolecular ortho [2+2] photocycloaddition of 5-(p-acylphenyl)-1-pentenes

Abstract The title compounds undergo intramolecular 2+2 ortho photocycloadditions to generate tricycloundecadienes 4 and 5. These are formed stereoselectively, with the four and five-membered rings anti to each other. Compounds 4 undergo low temperature Cope rearrangements to generate epimers of 5 and also open to equilibrium mixtures of bicycloundecatrienes and tricycloundecadienes 7. The latter revert photochemically to the original phenyl ketones.
A Refined Ephemeris and Phase-resolved X-Ray Spectroscopy of the Geminga Pulsar

We present a refined, phase-connected, postglitch ephemeris for the Geminga pulsar that is a good fit to all the postglitch data from EGRET, ASCA, and XMM-Newton. We also present the results of phase-resolved spectroscopy of two XMM-Newton X-ray observations of the Geminga pulsar obtained in 2002 and 2004. An investigation is made into a previously claimed existence of a small hot spot on the neutron star surface. We conclude that that interpretation was more likely an artifact of an overly restrictive assumption used to fit the phase-resolved spectra: namely, that the spectral index of the nonthermal component is constant. When we allow the spectral index to vary as a function of rotation phase, we find systematic variations in spectral index, and such fits do not require an additional hot blackbody component.
Motion segmentation by SCC on the hopkins 155 database

We apply the Spectral Curvature Clustering (SCC) algorithm to a benchmark database of 155 motion sequences, and show that it outperforms all other state-of-the-art methods. The average misclassification rate by SCC is 1.41% for sequences having two motions and4.85% for three motions.
Integral generators for the cohomology ring of moduli spaces of sheaves over Poisson surfaces

Abstract Let M be a smooth and compact moduli space of stable coherent sheaves on a projective surface S with an effective (or trivial) anti-canonical line bundle. We find generators for the cohomology ring of M , with integral coefficients. When S is simply connected and a universal sheaf E exists over S × M , then its class [ E ] admits a Kunneth decomposition as a class in the tensor product K top 0 ( S ) ⊗ K top 0 ( M ) of the topological K-rings. The generators are the Chern classes of the Kunneth factors of [ E ] in K top 0 ( M ) . The general case is similar.
Anomalies on orbifolds

We discuss the form of the chiral anomaly on an S1/Z2 orbifold with chiral boundary conditions. We find that the 4-divergence of the higher-dimensional current evaluated at a given point in the extra dimension is proportional to the probability of finding the chiral zero mode there. Nevertheless the anomaly, appropriately defined as the five dimensional divergence of the current, lives entirely on the orbifold fixed planes and is independent of the shape of the zero mode. Therefore long distance four dimensional anomaly cancellation ensures the consistency of the higher dimensional orbifold theory.
On the spatial representation of preference profiles

Given a set of alternatives with multiple attributes, I characterize the set of preference profiles that are representable by weighted versions of a class of utility functions indexed by a parameter δ > 0, where δ ≥ 1 corresponds to the set of Minkowski’s (1886) metric functions. In light of the starkly different consequences between representability with δ ≤ 1 or with δ > 1, I propose a test to empirically estimate δ and I discuss the theoretical and empirical implications for spatial models of political competition.
Maximum Entropy Reconstruction of the Interstellar Medium. I. Theory

We have developed a technique to map the three-dimensional structure of the local interstellar medium using a maximum entropy reconstruction technique. A set of column densities to stars of known distance can in principle be used to recover a three-dimensional density field , since the two quantities are related by simple geometry through the equation = , where is a matrix characterizing the stellar spatial distribution. In practice, however, there are an infinite number of solutions to this equation. We use a maximum entropy reconstruction algorithm to find the density field containing the least information which is consistent with the observations. The solution obtained with this technique is, in some sense, the model containing the minimum structure. We apply the algorithm to several simulated data sets to demonstrate its feasibility and success at recovering "real" density contrasts. This technique can be applied to any set of column densities whose endpoints are specified. In a subsequent paper we shall describe the application of this method to a set of stellar color excesses in order to derive a map of the dust distribution and to soft X-ray absorption columns to hot stars in order to derive a map of the total density of the interstellar medium.
Laser cladding of Mg-Al alloys

Among rapid solidification processing methods, laser cladding is a unique and promising technique which can be used to increase the corrosion resistance of materials. This paper describes the improvement of the laser-cladding process for magnesium-based alloys and an investigation of the effect of the laser-cladding technique upon the microstructure and the corrosion resistance of magnesium-based alloys. The cladding apparatus and techniques have been adapted for magnesium cladding to overcome the oxidation and high vapour pressurerelated problems. Laser-clad Mg27Al73, Mg53Al47, and Mg72Al28 have been obtained. Eutectic phases were observed in the two magnesium-rich alloys and in the interface of the aluminiumrich alloy. Polycrystalline structure was formed in Mg27Al73. Laser-clad Mg27Al73 was found to be superior to laser-clad Mg-5 wt% Zr, Mg-2 wt% Zr, cast AZ91 B and cast magnesium in corrosion properties.
Cooling of an atomic beam with frequency-sweep techniques

Abstract We review the ideas of velocity-modifying an atomic beam by resonant scattering of intense light from a frequency-swept laser source. Some of the realistic parasitic effects, particularly fluctuations and residual transverse heating are considered. A computer Monte-Carlo simulation program is described which provides encouragement and insights useful in the design of a real atomic beam apparatus. We described a new rf/optical modulation method to generate the desired laser optical frequency and intensity profiles versus time. This digital method provides the necessary sweep accuracy and program flexibility in a convenient and powerful way.
Monodispersed Colloidal Spheres: Old Materials with New Applications

This article presents an overview of current research activities that center on monodispersed colloidal spheres whose diameter falls anywhere in the range of 10 nm to 1 μm. It is organized into three parts: The first part briefly discusses several useful methods that have been developed for producing monodispersed colloidal spheres with tightly controlled sizes and well-defined properties (both surface and bulk). The second part surveys some techniques that have been demonstrated for organizing these colloidal spheres into two- and three-dimensionally ordered lattices. The third part highlights a number of unique applications of these crystalline assemblies, such as their uses as photonic bandgap (PBG) crystals; as removable templates to fabricate macroporous materials with highly ordered and three-dimensionally interconnected porous structures; as physical masks in lithographic patterning; and as diffractive elements to fabricate new types of optical sensors. Finally, we conclude with some personal perspectives on the directions towards which future research in this area might be directed.
Incentive-Centered Design for Security

Security problems are incentives problems: we build defenses because people want to do things that (intentionally or inadvertently) cause harm. Yet, much research disregards systematic study of the motivations of smart, responsive, autonomous humans in the loop. Meanwhile, the maturing sciences of motivated behavior offer a growing body of theoretical, statistical, and laboratory evidence on systematic responses to motivations that can be incorporated in the system design toolkit. By adjusting incentives, it's sometimes possible to induce bad guys to stay out, encourage good guys to improve secure practices, and discourage otherwise good guys with system access from becoming delinquent.
Encoding types in ML-like languages

This article presents several general approaches to programming with type-indexed families of values within a Hindley-Milner type system. A type-indexed family of values is a function that maps a family of types to a family of values. The function performs a case analysis on the input types and returns values of possibly different types. Such a case analysis on types seems to be prohibited by the Hindley-Milner type system. Our approaches solve the problem by using type encodings. The compile-time types of the type encodings reflect the types themselves, thereby making the approaches type-safe, in the sense that the underlying type system statically prevents any mismatch between the input type and the function arguments that depend on this type.A type encoding could be either value-dependent, meaning that the type encoding is tied to a specific type-indexed family, or value-independent, meaning that the type encoding can be shared by various type-indexed families. Our first approach is value-dependent: we simply interpret a type as its corresponding value. Our second approach provides value-independent type encodings through embedding and projection functions; they are universal type interpretations, in that they can be used to compute other type interpretations. We also present an alternative approach to value-independent type encodings, using higher-order functors.We demonstrate our techniques through applications such as C printf-like formatting, type-directed partial evaluation, and subtype coercions.
An ultra stable optical bench for the magnetic survey satellite

Abstract An optical bench has been designed and built that must hold the alignment of five optical elements to deflections of 1–2 arc s during orbital operation. In addition, it must suffer no alignment changes during the launch and prestabilization phase of the mission. Severe weight constraints, in conjunction with the thermal and structural requirements, led to the choice of graphite fiber reinforced epoxy egg crate core and face sheets for the bench construction. Active temperature control was necessary to meet thermal deflection objectives, and novel kinematic mountings were required to prevent spacecraft bending from deflecting the bench. The structural and thermal analyses both show that the mission objectives can be met with margin by the present design. No adverse effects from launch are expected, and the maximum thermal bending is expected to be less than 2 arc s.
Trajectory design for the Mariner-Mars 1964 mission.

Mariner IV trajectory analysis and importance of flight-path selection in construction of basic mission profile
Synthesis of (1-S) and (1-R) cis 2-methylcyclopentanols through lipase mediated resolution

Abstract The lipase catalyzed enantioselective transacylation of (±) cis-2-methylcyclopentanol is described.
Further Synthetic Studies on the Conversion of Alcohols into Phenylthio Ethers

Abstract The conversion of sterically encumbered alcohols into their corresponding phenylthio ethers employing phenyl disulfide and tri-n-butylphosphine was investigated.
Alterations in brain structure related to breast cancer and its treatment: chemotherapy and other considerations.

Cognitive effects of cancer and its treatment have been a topic of increasing investigation over the past ~30 years. Recent studies have focused on better understanding the neural correlates of these effects, with an emphasis on post-chemotherapy effects in breast cancer patients. Structural MRI studies have utilized both automated and manual approaches to quantify gray and white matter characteristics (e.g., regional volume and density) in breast cancer patients treated with chemotherapy relative to patients who did not receive chemotherapy and/or healthy controls. While most work to date has been retrospective, a small number of baseline (pre-systemic therapy) and prospective longitudinal studies have been conducted. Data have consistently shown lower gray and white matter volume and density in patients treated with chemotherapy, particularly in frontal and temporal brain regions. Host factors and/or the cancer disease process and other therapies (e.g., antiestrogen treatment) also seem likely to contribute to the observed differences, though the relative contributions of these effects have not yet been investigated in detail. These structural abnormalities have been shown to relate to subjective and objective cognitive functioning, as well as to biological factors that may help to elucidate the underlying mechanism(s). This review examines the currently available published observations and discusses the major themes and promising directions for future studies.
A semiclassical reactive flux method for the calculation of condensed phase activated rate constants

Abstract A semi classical reactive flux algorithm for calculating thermally activated rate constants is presented which is based on a semi-classical transition state theory due to Chapman, Garrett and Miller [J. Chem. Phys. 63 (1975) 2710]. This reactive flux technique, when combined with the semiclassical TST, enables one to describe dynamical recrossings of the transition state on the same footing as tunneling effects. Most importantly, the method is readily applied to nonlinear multidimensional systems over a wide range of temperatures. It will be shown that the method works very well for a variety of existing models.
Soliton Formation in Whispering-Gallery-Mode Resonators via Input Phase Modulation

We propose a systematic method for soliton formation in whispering-gallery-mode (WGM) resonators through input phase modulation. Our numerical simulations of a variant of the Lugiato–Lefever equation (LLE) suggest that modulating the input phase at a frequency equal to the resonator free spectral range and at modest modulation depths provides a deterministic route toward soliton formation in WGM resonators without undergoing a chaotic phase. We show that the generated solitonic state is sustained when the modulation is turned off adiabatically. Our results support parametric seeding as a powerful means of control, in addition to input pump power and pump-resonance detuning, over frequency comb generation in WGM resonators. Our findings also help pave the way toward ultrashort pulse formation on a chip.
An efficient method for the incompressible Navier-Stokes equations on irregular domains with no-slip boundary conditions, high order up to the boundary

Common efficient schemes for the incompressible Navier-Stokes equations, such as projection or fractional step methods, have limited temporal accuracy as a result of matrix splitting errors, or introduce errors near the domain boundaries (which destroy uniform convergence to the solution). In this paper we recast the incompressible (constant density) Navier-Stokes equations (with the velocity prescribed at the boundary) as an equivalent system, for the primary variables velocity and pressure. equation for the pressure. The key difference from the usual approaches occurs at the boundaries, where we use boundary conditions that unequivocally allow the pressure to be recovered from knowledge of the velocity at any fixed time. This avoids the common difficulty of an, apparently, over-determined Poisson problem. Since in this alternative formulation the pressure can be accurately and efficiently recovered from the velocity, the recast equations are ideal for numerical marching methods. The new system can be discretized using a variety of methods, including semi-implicit treatments of viscosity, and in principle to any desired order of accuracy. In this work we illustrate the approach with a 2-D second order finite difference scheme on a Cartesian grid, and devise an algorithm to solve the equations on domains with curved (non-conforming) boundaries, including a case with a non-trivial topology (a circular obstruction inside the domain). This algorithm achieves second order accuracy in the L^~ norm, for both the velocity and the pressure. The scheme has a natural extension to 3-D.
Multiple-size divide-and-conquer recurrences

This short note reports a master theorem on tight asymptotic solutions to divide-and-conquer recurrences with more than one recursive term: for example, T(n) = 1/4 T(n/16) + 1/3 T(3n/5) + 4 T(n/100) + 10 T(n/300) + n^2.
Kullback–Leibler entropy and Penrose conjecture in the Lemaître–Tolman–Bondi model

Our universe hosts various large-scale structures from voids to galaxy clusters, so it would be interesting to find some simple and reasonable measure to describe the inhomogeneities in the universe. We explore two different methods for this purpose: the Kullback–Leibler entropy and the Weyl curvature tensor. These two quantities characterize the deviation of the actual distribution of matter from the unperturbed background. We calculate these two measures in the spherically symmetric Lemaitre–Tolman–Bondi model in the dust universe. Both exact and perturbative calculations are presented, and we observe that these two measures are in proportion up to second order.
STEPWISE SQUARE INTEGRABLE REPRESENTATIONS FOR LOCALLY NILPOTENT LIE GROUPS

In a recent paper we found conditions for a nilpotent Lie group N to have a filtration by normal subgroups whose successive quotients have square integrable representations, and such that these square integrable representations fit together nicely to give an explicit construction of Plancherel for almost all representations of N. The prototype for this sort of group is the group of upper triangular real matrices with 1’s down the diagonal. More generally, this class of groups contains the nilradicals of minimal parabolic subgroups of all (finite-dimensional) reductive real or complex Lie groups, in other words, all groups N in Iwasawa decompositions of reductive real or complex Lie groups.
Constructible sheaves and the Fukaya category

Let $X$ be a compact real analytic manifold, and let $T^*X$ be its cotangent bundle. Let $Sh(X)$ be the triangulated dg category of bounded, constructible complexes of sheaves on $X$. In this paper, we develop a Fukaya $A_\infty$-category $Fuk(T^*X)$ whose objects are exact, not necessarily compact Lagrangian branes in the cotangent bundle. We write $Tw Fuk(T^*X)$ for the $A_\infty$-triangulated envelope of $Fuk(T^*X)$ consisting of twisted complexes of Lagrangian branes. Our main result is that $Sh(X)$ quasi-embeds into $Tw Fuk(T^*X)$ as an $A_\infty$-category. Taking cohomology gives an embedding of the corresponding derived categories.