cssi/SciSciGPT-SciSciNet huggingface dataset:
Algorithmic computation of de Rham cohomology of complements of complex affine varieties

Abstract Let X = C n . In this paper we present an algorithm that computes the de Rham cohomology groups H dR i ( U , C ) where U is the complement of an arbitrary Zariski-closed set Y in X . Our algorithm is a merger of the algorithm given inOaku and Takayama (1999), who considered the case where Y is a hypersurface, and our methods from Walther (1999) for the computation of local cohomology. We further extend the algorithm to compute de Rham cohomology groups with supports H dR , Z i ( U , C ) where again U is an arbitrary Zariski-open subset of X and Z is an arbitrary Zariski-closed subset of U . Our main tool is a generalization of the restriction process from Oaku and Takayama (in press) to complexes of modules over the Weyl algebra. The restriction rests on an existence theorem on V d -strict resolutions of complexes that we prove by means of an explicit construction via Cartan–Eilenberg resolutions. All presented algorithms are based on Grobner basis computations in the Weyl algebra and the examples are carried out using the computer system Kan by Takayama (1999).
Optimal tooth numbers for compact standard spur gear sets

The design of a standard gear mesh is treated with the objective of minimizing the gear size for a given ratio, pinion torque, and allowable tooth strength. Scoring, pitting fatigue, bending fatigue, and the kinematic limits of contact ratio and interference are considered. A design space is defined in terms of the number of teeth on the pinion and the diametral pitch. This space is then combined with the objective function of minimum center distance to obtain an optimal design region. This region defines the number of pinion teeth for the most compact design. The number is a function of the gear ratio only. A design example illustrating this procedure is also given.
Applications of oxaziridines in organic synthesis

Cet article de synthese, sur les N-aryl- et N-alkyl oxaziridines, rapporte la preparation de ces composes et leurs reactivites lors de reactions de transfert d'oxygene, de reactions nucleophiles et de transpositions chimiques; l'oxydation de sulfonyl-1 oxaziridines est egalement etudiee
Thermal effects of insolation propagation into the regoliths of airless bodies

The planetary surface thermal models used in the present study are composed of particles which, while bright and optically thin in the visual, are dark and opaque in the thermal IR. It is assumed that insolation is absorbed over a finite regolith distance whose scale length relative to diurnal skin depth for thermal diffusion can be substantial. Attention is given to the lower daytime and higher nighttime temperatures predicted by comparison with models assuming absorption only at the surface. It is noted that, with sufficiently deep penetration of insulation and high thermal IR particle opacity, a solid-state greenhouse can result.
Palladium and nickel catalyzed thio-Claisen rearrangements of chiral bicyclic thiolactams (via N,S-ketene acetals)

Abstract Pd, Ni, and Lewis acid catalyzed rearrangements occur under milder conditions than the thermal version of the titled rearrangements.
Do Teaser-Rate Adjustable-Rate Mortgages Make Owner-Occupied Housing More Affordable?

Abstract In this paper, we estimate the structural parameters of an aggregate housing demand curve and the relationship between ARM teaser rates and house prices using a simultaneous-equation Tobit model. The data come primarily from the Federal Housing Finance Board monthly interest rate survey in May of 1987-1989. The empirical results suggest that teaser ARMs produce significant price distortions in local housing markets. These price distortions ameliorate housing affordability for teaser ARM borrowers and worsen affordability problems for all other homebuyers.
Synthesis and Polymerization of a Chiral Liquid Crystal Diacrylate Exhibiting Smectic A* and C* Phases

The alignment and cross-linking of chiral liquid crystal (LC) phases has been used to generate ordered noncentrosymmetric polymer networks with a variety of interesting optical and transducer prope...
Training feed-forward neural networks using conjugate gradients

Neural networks for optical character recognition are still being trained using back propagation, even though conjugate gradient methods have been shown to be much faster. Most multilayer perceptron network training results in the literature are obtained for small and unrealistic problems or from data sets that are proprietary and not available for comparison testing. We present results on a large realistic pattern set containing 2000 training and 1434 testing exemplars. Each pattern is composed of 32 Gabor coefficients obtained from a 32 by 32 pixel binary image of a handwritten digit segmented from the NIST Handwriting Image Data Base. These sets are believed to have approximately 1 segmentation errors. Comparative results for Moller''s scaled conjugate gradient method and for standard back propagation are presented for runs on a serial scientific workstation and a highly parallel computer. Typical training on a network with 32 inputs, 32 hidden nodes, and 10 output nodes gives a 98 recognition for the training set and 95 for the test set. Training with conjugate gradients requires fewer than 200 iterations; times are about 20 to 40 minutes on a scientific workstation and 6 minutes on the highly parallel computer. Testing (classification) is done at the rate of 600 to 1600 patterns per second on the scientific workstation and on the highly parallel computer respectively. These results suggest that commercial handwritten character recognition systems with great economic potential are feasible.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Performance Analysis of Multiuser Selection Diversity

In this paper, the authors study the performance of scheduling algorithms exploiting the multiuser selection diversity. Schedulers with affordable-rate transmission and adaptive transmission based on the absolute signal-to-noise ratio (SNR) and the normalized SNR are considered. In contrast to previous studies on the multiuser-diversity systems, the channel dynamics is taken into consideration in this paper by a novel formulation based on the level crossing analysis of stochastic processes. Then, the authors make the connection between the Doppler frequency shift, which indicates the channel temporal correlation, and the average (channel) access time, the average waiting time (AWT) between accesses, and the average access rate (AAR) of active users. These properties are important for the scheduler design, especially for applications where delay is a concern. In addition, analytical expressions for the system throughput and the degree of fairness (DOF) when users have nonidentical average channel conditions are presented. These expressions quantify the effect of disparateness in users' average channel conditions on the system performance
Confronting catastrophe: norms, efficiency and the evolution of the AIDS battle in the UN

Social environments played a powerful role in the institutional adaptations of the AIDS fighting agencies within the United Nations system. Since its AIDS apparatus has become operational, the UN has undertaken two major strategic shifts. The first shift saw the dissolution of the GPA, a small subunit of the WHO in favour of UNAIDS, a dedicated agency engaged in global advocacy. This shift involved a controversial bureaucratic process that led, finally, to a more human rights-based approach to the disease. The second shift saw an increased emphasis on ground-level efficiency. What caused these changes? Contributions in the rationalist tradition expect the UN to act as a multilateral goal-seeker looking to optimally address a major gap in global governance. A sociological framework sees normative changes within the UN as catalysts for change in its goals and structure. A synthesis of these traditions conceptualizes the UN's strategic shifts more clearly, capturing the interactive process between the organi...
Astrometric effects of a stochastic gravitational wave background

A stochastic gravitational wave background causes the apparent positions of distant sources to fluctuate, with angular deflections of order the characteristic strain amplitude of the gravitational waves. These fluctuations may be detectable with high precision astrometry, as first suggested by Braginsky et al. in 1990. Several researchers have made order of magnitude estimates of the upper limits obtainable on the gravitational wave spectrum Ω_(gw)(f), at frequencies of order f~1 yr^(-1), both for the future space-based optical interferometry missions GAIA and SIM, and for very long baseline interferometry in radio wavelengths with the SKA. For GAIA, tracking N~10^6 quasars over a time of T~1 yr with an angular accuracy of Δθ∼10μ as would yield a sensitivity level of Ω_(gw)~(Δθ)^2/(NT^2H_0^2)~10^(-6), which would be comparable with pulsar timing. In this paper we take a first step toward firming up these estimates by computing in detail the statistical properties of the angular deflections caused by a stochastic background. We compute analytically the two-point correlation function of the deflections on the sphere, and the spectrum as a function of frequency and angular scale. The fluctuations are concentrated at low frequencies (for a scale invariant stochastic background), and at large angular scales, starting with the quadrupole. The magnetic-type and electric-type pieces of the fluctuations have equal amounts of power.
A game theoretic model for the Gaussian broadcast channel

The strategic behavior of receivers (players) in a multiple-input multiple-output Gaussian broadcast channel is investigated using the framework of non-cooperative game theory. In contrast to the non-cooperative Gaussian multiple access channel game in which each player's feasible set of actions is independent of the actions of other players, the action space of receivers in the Gaussian broadcast channel is mutually coupled, usually by a sum power or joint covariance constraint, and hence cannot be treated using traditional Nash equilibrium solution concepts. To characterize the strategic behavior of receivers in a broadcast channel game, this paper treats the broadcast channel power allocation (or covariance matrix selection) as a generalized Nash equilibrium problem with common constraints. The concept of normalized equilibrium (NoE) is used to characterize the equilibria and the existence and uniqueness of NoEs are proven for key scenarios.
Interference Alignment with Analog Channel State Feedback

Interference alignment (IA) is a multiplexing gain optimal transmission strategy for the interference channel. While the achieved sum rate with IA is much higher than previously thought possible, the improvement comes at the cost of requiring network channel state information at the transmitters. This can be achieved by explicit feedback, a flexible yet potentially costly approach that incurs large overhead. In this paper we propose analog feedback as an alternative to limited feedback or reciprocity based alignment. We show that the full multiplexing gain observed with perfect channel knowledge is preserved by analog feedback and that the mean loss in sum rate is bounded by a constant when signal-to-noise ratio is comparable in both forward and feedback channels. When signal-to-noise ratios are not quite symmetric, a fraction of the multiplexing gain is achieved. We consider the overhead of training and feedback and use this framework to numerically optimize the system's effective throughput. We present simulation results to demonstrate the performance of IA with analog feedback, verify our theoretical analysis, and extend our conclusions on optimal training and feedback length.
Random surfaces and lattice gravity

Abstract In this talk I review some of the recent developments in the field of random surfaces and the Dynamical Triangulation approach to simplicial quantum gravity. In two dimensions I focus on the c = 1 barrier and the fractal dimension of two-dimensional quantum gravity coupled to matter with emphasis on the comparison of analytic predictions and numerical simulations. Next is a survey of the current understanding in 3 and 4 dimensions. This is followed by a discussion of some problems in the statistical mechanics of membranes. Finally I conclude with a list of problems for the future.
Aerodynamic requirements of a manned Mars aerobraking transfer vehicle

In this investigation, entry corridor analyses are performed to identify the aerodynamic requirements of a manned Mars aerobraking transfer vehicle. The major emphasis is on identifying the required aerobrake hypersonic L/D to insure a successful aerocapture. Aerobraking entry requirements are also imposed on a set of interplanetary mission opportunities to demonstrate their effect on mission flexibility. Based on the requirements of a 1 deg corridor width, deceleration into a parking orbit witn an apoapsis altitude of 32,972 km, and a 5-g deceleration limit, a manned Mars aerobrake characterized by an L/D of at least 1.5 is required for entry velocities as high as 10.0 km/sec. Limiting the Mars entry velocity to values below 8.5 km/sec is shown to induce a minor restriction on mission flexibility while alleviating aerothermodynamic and vehicle packaging concerns; hence, Mars entry velocities in the range of 6.0-8.5 km/sec are suggested, and a manned Mars aerobrake characterized by an L/D between 0.3 and 0.5 is recommended.
The ratchet effect and bargaining power in a two-stage model of competitive bidding*

In the model presented, a buyer uses competitive bidding to facilitate her purchase of a good (the primary good of the exchange). Not included in the original purchase is the possible procurement of a good related to the original purchase: the supplementary good. The primary and supplementary goods are closely related; knowing a bidder's cost of producing the primary good implies that the buyer can infer the bidder's cost of producing the supplementary good. I show that a bidding mechanism for the primary good will fail to ensure an efficient allocation if the buyer learns the bid of the winner and the price of the supplementary good is determined through sequential bargaining.
Pressure fluctuations in pneumatic conveying systems

Abstract The pressure fluctuations generated in pneumatic conveying of solids in a horizontal piping arrangement have been studied in order to provide a technique for flow pattern identification and control of the pneumatic conveying operation. Practitioners of pneumatic conveying have used flow noise production in pneumatic conveying as a technique to diagnose the operation of such systems. The pressure fluctuations measured were placed in power spectral density function (PSDF) format and related to the flow patterns, visually observed. Distinguishing PSDFs were observed for the various flow pattern regimes. The effect of particle size, system configuration, pressure transducer type and acquisition parameters were explored. The analysis was carried out on-line so that control strategies can be employed. The pressure tap spacing did not influence the spectra generated at the various flow regimes. Static pressure transducers proved more reliable for homogeneous and stratified flows detection while differential pressure transducers were preferred for the dune/slug flow condition.
Studies on the effects of substituents on rate enhancements in intramolecular diels-alder reactions: Reasons for the gem-dimethyl effect

Comparison of the rates of cyclization of a series of 2-furfuryl methyl fumarates leads to the conclusion that the gem-dimethyl effect is due primarily to higher population of reactive rotamers.
Message and state cooperation in a relay channel when the relay has strictly causal state information

A state-dependent relay channel is studied in which strictly causal channel state information is available at the relay and no state information is available at the source and destination. Source and relay are connected via two unidirectional out-of-band orthogonal links of finite capacity, and a state-dependent memoryless channel connects source and relay, on one side, and the destination, on the other. Via the orthogonal links, the source can convey information about the message to be delivered to the destination to the relay while the relay can forward state information to the source. This exchange enables cooperation between source and relay on both transmission of message and state information to the destination. First, an achievable scheme, inspired by noisy network coding, is proposed that exploits both message and state cooperation. Next, based on the given achievable rate and appropriate upper bounds, capacity results are identified for some special cases. Finally, a Gaussian model is studied, along with corresponding numerical results that illuminate the relative merits of state and message cooperation.
Properties of the working-set model

A program's working set W(t, T) at time t is the set of distinct pages among the T most recently referenced pages. Relations between the average working-set size, the missing-page rate, and the interreference-interval distribution may be derived both from time-average definitions and from ensemble-average (statistical) definitions. An efficient algorithm for estimating these quantities is given. The relation to LRU (lease recently used) paging is characterized. The independent-reference model, in which page references are statistically independent, is used to assess the effects of interpage dependencies on working-set size observations. Under general assumptions, working-set size is shown to be normally distributed.
The asymptotic behavior of minimum buffer size requirements in large P2P streaming networks

The growth of real-time content streaming over the Internet has resulted in the use of peer-to-peer (P2P) approaches for scalable content delivery. In such P2P streaming systems, each peer maintains a playout buffer of content chunks which it attempts to fill by contacting other peers in the network. The objective is to ensure that the chunk to be played out is available with high probability while keeping the buffer size small. Given that a particular peer has been selected, a policy is a rule that suggests which chunks should be requested by the peer from other peers. We consider consider a number of recently suggested policies consistent with buffer minimization for a given target of skip free playout. We first study a rarest-first policy that attempts to obtain chunks farthest from playout, and a greedy policy that attempts to obtain chunks nearest to playout. We show that they both have similar buffer scalings (as a function of the number of peers and the target skip-free probability). We then study a hybrid policy which achieves order sense improvements over both policies and can achieve order optimal performance. We validate our results using simulations.
Quasi Stationary States in the Southern Hemisphere

Pattern correlations between daily anomalies have been used to study the persistence of the Southern Hemisphere circulations. The dataset consists of daily Australian analyses of 500 mb heights and sea level pressure for the period from 1972 to 1983. Compared to the Northern Hemisphere, the pattern correlations are much lower and more variable in the Southern Hemisphere. The mean one-day lag autocorrelation is only 0.57, compared to 0.81 in the Northern Hemisphere. The correlations increase significantly for the filtered anomalies, which consist of the planetary wavenumbers from 0 to 4. Subjective criteria based on the pattern correlations are used to select quasi-stationary events. A series of 5 or more daily maps is defined to be quasi-stationary if the pattern correlations between all pairs of five consecutive maps in this time series are larger than or equal to 0.5. In winter, quasi-stationary events can be classified in terms of wavenumbers. Waves 3 and 4 are by far the dominant waves. More than half of the events have large wave 3 amplitude with geographically fixed orientations.
What have we learned and want to learn from heavy ion collisions at CERN SPS

Abstract The talk is a mini-review of current status of the field, with emphasis on SPS heavy ion program, now and beyond 2000 (as asked by the organizers). The main question is, of course, whether we can convince ourselves and community at large that the QGP is in fact produced at SPS. We came a long way toward the positive answer, and are definitely on strongly rising part of the learning curve. Still, in few key directions we lack important pieces of evidences.
An algebraic geometry algorithm for scheduling in presence of setups and correlated demands

We study here a problem of schedulingn job types onm parallel machines, when setups are required and the demands for the products are correlated random variables. We model this problem as a chance constrained integer program. Methods of solution currently available—in integer programming and stochastic programming—are not sufficient to solve this model exactly. We develop and introduce here a new approach, based on a geometric interpretation of some recent results in Grobner basis theory, to provide a solution method applicable to a general class of chance constrained integer programming problems. Out algorithm is conceptually simple and easy to implement. Starting from a (possibly) infeasible solution, we move from one lattice point to another in a monotone manner regularly querying a membership oracle for feasibility until the optimal solution is found. We illustrate this methodology by solving a problem based on a real system.
Panspermia: Unlikely, unsupported, but just possible

Abstract The question—are we alone in the Universe?—has been discussed for at least 2500 years. Initially philosophical and religious beliefs were used as arguments, but for over 100 years the possible transfer of bacteria and other microorganisms from planets, comets or meteroids to other planets—panspermia—has been seriously considered. Possible mechanisms for this transfer exist and some microorganisms are known to be extremely resistant to very low temperatures, very high vacuum and intense high-energy radiation. Hoyle and his colleagues have published many claims that interstellar grains are partly, or even wholly, bacteria and or diatoms and that life, evolution and many diseases would not have occurred on Earth without panspermia. The evidence and interpretations presented have not been accepted by the genral body of biologists or astronomers. The present situation is that panspermia is unlikely, so far completely unsupported, but is just possible for viable, and somewhat more so for dead, microorganisms, so it should be investigated.
Synthesis of benzopurpurins, isobacteriobenzopurpurins and bacteriobenzopurpurins

Abstract Cyclization of porphyrins substituted at the meso position(s) with acrylate or acrolein groups leads to the formation of benzopurpurin derivatives at the oxidation state of a chlorin, bacteriochlorin or isobacteriochlorin, depending upon reaction conditions.
Financial Innovation in a General Equilibrium Model

Abstract We develop a model of financial innovation, in which intermediaries can issue new financial securities against collateral in the form of standard securities. Intermediaries have to market their innovations and marketing is costly. We show that the equilibrium asset structure may exhibit redundancies as frequently observed on financial markets. We give conditions for efficiency of financial innovation and show that with small innovation costs the indeterminacy of equilibrium allocations has small utility consequences. Journal of Economic Literature Classification Numbers: D52, G10.
Rearrangement Invariant Norms of Symmetric Sequence Norms of Independent Sequences of Random Variables

LetX 1,X 2, …,X n be a sequence of independent random variables, letM be a rearrangement invariant space on the underlying probability space, and letN be a symmetric sequence space. This paper gives an approximate formula for the quantity ‖‖(X i )‖ N ‖ M wheneverL q embeds intoM for some 1≤q<∞. This extends work of Johnson and Schechtman who tackled the case whenN=l p , and recent work of Gordon, Litvak, Schutt and Werner who obtained similar results for Orlicz spaces.
Simultaneous determination of hydrocodone and hydromorphone in human plasma by liquid chromatography with tandem mass spectrometric detection.

Abstract A rapid, sensitive and specific liquid chromatography–tandem mass spectrometry (LC–MS–MS) method has been developed and validated for the simultaneous analysis of hydrocodone (HYC) and its metabolite hydromorphone (HYM) in human plasma. A robotic liquid handler and a 96-channel liquid handling workstation were used to aliquot samples, to add internal standard (I.S.), and to extract analytes of interest. A 96-well mixed-mode solid-phase cartridge plate was used to extract the analytes and I.S. The chromatographic separation was on a silica column (50×3 mm, 5-μm) with a mobile phase consisting of acetonitrile, water and trifluoroacetic acid (TFA) (92:8:0.01, v/v). The run time for each injection was 2.5 min with the retention times of approximately 2.1 and 2.2 min for HYC and HYM, respectively. The tandem mass spectrometric detection was by monitoring singly charged precursor→product ion transition 300→199 ( m/z ) for HYC, and 286→185 ( m/z ) for HYM. The validated calibration curve range was 0.100–100 ng/ml, based on a plasma volume of 0.3 ml. The correlation coefficients were greater than or equal to 0.9996 for both HYC and HYM. The low limit of quantitation (LLOQ) was 0.100 ng/ml for both HYC and HYM with signal-to-noise ratio ( S/N ) of 50 and 10, respectively. The deuterated analytes, used as internal standards, were monitored at mass transitions 303→199 ( m/z ) for HYC- d 3 and 289→185 ( m/z ) for HYM- d 3 . The inter-day ( n =17) precision of the quality control (QC) samples were ≤3.5% RSD (relative standard deviation) for HYC and ≤4.7% RSD for HYM, respectively. The inter-day accuracy of the QC samples were ≤2.1% RE (relative error) for HYC and ≤1.8% RE for HYM. The intra-day ( n =6) precision and accuracy of the QC samples were ≤2.6% RSD and ≤3.0% RE for HYC, and ≤4.7% RSD and ≤2.4% RE for HYM. There was no significant deviation from the nominal values after a 5-fold dilution of high concentration QC samples by blank matrix. The QC samples were stable when kept at room temperature for 24-h or experienced three freeze–thaw cycles. The extraction recoveries were 86% for HYC and 78% for HYM. No detectable carryover was observed when a blank sample was injected immediately after a 2500 ng/ml sample that was 25-fold more concentrated than the upper limit of quantitation (ULOQ).
Expeditious oligosaccharide synthesis via selective, semi-orthogonal, and orthogonal activation

Traditional strategies for oligosaccharide synthesis often require extensive protecting and/or leaving group manipulations between each glycosylation step, thereby increasing the total number of synthetic steps while decreasing the efficiency of the synthesis. In contrast, expeditious strategies allow for the rapid chemical synthesis of complex carbohydrates by minimizing extraneous chemical manipulations. Oligosaccharide synthesis by selective activation of one leaving group over another is one such expeditious strategy. Herein, the significant improvements that have recently emerged in the area of the selective activation are discussed. The development of orthogonal strategy further expands the scope of the selective activation methodology. Surveyed in this article, are representative examples wherein these excellent innovations have been applied to the synthesis of various oligosaccharide sequences.
INTRAMOLECULAR PALLADIUM CATALYZED ALKOXY CARBONYLATION OF 6-HYDROXY-1-OCTENES. STEREOSELECTIVE SYNTHESIS OF SUBSTITUTED TETRAHYDROPYRANS

The reaction of hydroxy alkenes 5, 7, and 8 with CO and MeOH in the presence of PdCl2 and CuCl2 gave tetrahydropyrans 9, 11, and 12, respectively. Yields were dependent upon the configuration of substituents in the hydroxy alkene; in all cases, the tetrahydropyran was produced with 2,6-cis configuration.
Extension of Lyapunov’s convexity theorem to subranges

Consider a measurable space with a finite vector measure. This measure defines a mapping of the σ-field into a Euclidean space. According to Lyapunov’s convexity theorem, the range of this mapping is compact and, if the measure is atomless, this range is convex. Similar ranges are also defined for measurable subsets of the space. We show that the union of the ranges of all subsets having the same given vector measure is also compact and, if the measure is atomless, it is convex. We further provide a geometrically constructed convex compactum in the Euclidean space that contains this union. The equality of these two sets, that holds for two-dimensional measures, can be violated in higher dimensions.
Rainbows, Halos, and Glories

Over 200 illustrations, many in full colour, capture for both the layman and scientist the beautiful optical effects that we see in the sky. The author describes and explains these effects in non-technical language.
One-millimeter brightness temperatures of the planets

New values for the 1 mm brightness temperatures of Mercury, Venus, Jupiter, Saturn, Uranus and Neptune were determined using Mars as the absolute photometric standard.
Probing the evolution of the dark energy density with future supernova surveys

The time dependence of the dark energy density can be an important clue to the nature of dark energy in the universe. We show that future supernova data from dedicated telescopes (such as SNAP), when combined with data of nearby supernovae, can be used to determine how the dark energy density ρX(z) depends on redshift, if ρX(z )i s not too closeto a constant. For quantitative comparison, we have done an extensive study of a number of dark energy models. Based on these models we have simulated data sets in order to show that we can indeed reconstruct the correct sign of the time dependence of the dark energy density, outside of a degeneracy region centred on 1 + w0 �− w1zmax/ 3( where zmax is the maximum redshift of the survey; for example, zmax =1 . 7f or SNAP).
Expression Signature of the Mouse Prostate

Genetically engineered mice are being used increasingly for delineating the molecular mechanisms of prostate cancer development. Epithelium-stroma interactions play a critical role in prostate development and tumorigenesis. To better understand gene expression patterns in the normal sexually mature mouse prostate, epithelium and stroma were laser-capture microdissected from ventral, dorsolateral, and anterior prostate lobes. Genome-wide expression was measured by DNA microarrays. Our analysis indicated that the gene expression pattern in the mouse dorsolateral lobe was closest to that of the human prostate peripheral zone, supporting the hypothesis that these prostate compartments are functionally equivalent. Stroma from a given lobe had closer gene expression patterns with stroma from other lobes than epithelium from the same lobe. Stroma appeared to have higher expression complexity than epithelium. Specifically, stromal cells had higher expression levels of genes implicated in cell adhesion, muscle development, and contraction, in structural constituents of cytoskeleton and actin binding, and in components such as sarcomere and extracellular matrix collagen. Among the genes that were enriched in the epithelium were secretory proteins, including seminal vesicle protein secretion 2 and 5. Surprisingly, prostate stroma expressed many osteogenic molecules, as confirmed by immunohistochemistry. A "bone-like" environment in the prostate may predispose prostate cells for survival in the bone. Chemokine Cxcl12 but not its receptor, Cxcr4, was expressed in normal prostate. In prostate tumors, interestingly, Cxcl12 was up-regulated in epithelial cells with a concomitant expression of Cxcr4. Expression of both the receptor and ligand may provide an autocrine mechanism for tumor cell migration and invasion.
Emission spectra of fallback disks around young neutron stars

The nature of the energy source powering anomalous X-ray pulsars (AXPs) is uncertain. Proposed scenarios involve either an ultramagnetized neutron star or accretion onto a neutron star. We consider the accretion model proposed recently by Chatterjee, Hernquist, & Narayan, in which a disk is fed by fallback material following a supernova. We compute the optical, infrared, and submillimeter emission expected from such a disk, including both viscous dissipation and reradiation of X-ray flux impinging on the disk from the pulsar. We find that it is possible with current instruments to put serious constraints on this and on other accretion models of AXPs. Fallback disks could also be found around isolated radio pulsars, and we compute the corresponding spectra. We show that the excess emission in the R and I bands observed for the pulsar PSR 0656+14 is broadly consistent with emission from a disk.
Treatment with CBA-NP a novel chimeric natriuretic peptide attenuates cardiorenal fibrosis and improves diastolic dysfunction in diabetic rat model

Diabetes is a major risk factor for left ventricular dysfunction with cardiac and renal fibrosis. C-type natriuretic peptide (CNP) is a 22 amino-acid peptide produced mainly in the cardiac endothelium with potent cardiac unloading, anti-fibrotic and antihypertensive effects, but minimal renal actions. Using this knowledge we designed a natriuretic peptide CBA-NP by fusing a 6 AA sequence (KVLRRH) from BNP to the C-terminus and a 5 AA sequence (RMDRI) from ANP to the N-terminus of CNP to enhance beneficial renal effects while maintaining CNP’s inherent cardioprotective properties.
A new adaptive learning rule

A method is presented for nonlinear function identification and application to learning control. The control objective is to identify and compensate for a nonlinear disturbance function. The nonlinear disturbance function is represented as an integral of a predefined kernel function multiplied by an unknown influence function. Sufficient conditions for the existence of such a representation are provided. Similarly, the nonlinear function estimate is generated by an integral of the predefined kernel multiplied by an influence function estimate. Using the time history of the plant, the learning rule indirectly estimates the unknown function by updating the influence function estimate. It is shown that the estimate function converges to the actual disturbance asymptotically. Consequently, the controller achieves the disturbance cancellation asymptotically. The method is extended to repetitive control applications. It is applied to the control of robot manipulators. Simulation and actual real-time implementation results using the Berkeley/NSK robot arm show that the proposed learning algorithm is more robust and converges at a faster rate than conventional repetitive controllers. >
Radiative Transfer on Perturbations in Protoplanetary Disks

We present a method for calculating the radiative transfer on a protoplanetary disk perturbed by a protoplanet. We apply this method to determine the effect on the temperature structure within the photosphere of a passive circumstellar disk in the vicinity of a small protoplanet of up to 20 Earth masses. The gravitational potential of a protoplanet induces a compression of the disk material near it, resulting in a decrement in the density at the disk's surface. Thus, an isodensity contour at the height of the photosphere takes on the shape of a well. When such a well is illuminated by stellar irradiation at grazing incidence, it results in cooling in a shadowed region and heating in an exposed region. For typical stellar and disk parameters relevant to the epoch of planet formation, we find that the temperature variation due to a protoplanet at 1 AU separation from its parent star is about 4% (5 K) for a planet of 1 Earth mass, about 14% (19 K) for planet of 10 Earth masses, and about 18% (25 K) for planet of 20 Earth masses, We conclude that even such relatively small protoplanets can induce temperature variations in a passive disk. Therefore, many of the processes involved in planet formation should not be modeled with a locally isothermal equation of state.
Nearly Coherent Oscillations in Type I X-Ray Bursts from KS 1731-260

We present an analysis of the full set of Rossi X-Ray Timing Explorer (RXTE) observations of KS 1731-260 made between 1996 August and 1999 February, concentrating on the nine type I X-ray bursts that were observed. We find that the bursts divide naturally into two populations: "fast bursts" occur on the Banana Branch when the accretion rate is high and exhibit short decay times, high peak fluxes, and radius expansion episodes. "Slow bursts" occur in the Island State at lower accretion rates, have lower peak fluxes, higher fluences, longer decay times, and show no evidence of radius expansion. All five of the fast bursts, and none of the four slow bursts, show coherent oscillations near 524 Hz. Thus, the mechanism that produces the burst pulsations may well be related to the helium-rich burning process indicated by the other properties of the fast bursts. We perform in-burst phase connection of the burst pulsations, which allows us to unambiguously characterize their frequency evolution. That evolution exhibits a variety of behaviors, including a sharp spin-down during one burst. The frequency evolution exhibited by two bursts that occurred 2.6 yr apart is consistent with nearly the same exponential-relaxation model; in particular, the asymptotic frequencies of the two bursts differ by only 0.13 ± 0.09 Hz. The evolution during another burst, not modeled as exponential, shows a maximum frequency which is 0.6 ± 0.2 Hz greater than the smaller of these asymptotic frequencies. Applying our phase models, we find that the pulsations are spectrally harder than the burst emission, with the strength of the pulsations increasing monotonically with photon energy. Coherently summing all of the burst signals, we find upper limits of ~5% relative to the power of the main pulse on any modulation at 1/2 or 3/2 the main pulse frequency. We discuss our results in the context of models in which the burst pulsations are produced by a hot spot on the surface of a spinning neutron star.
Conformational analysis of Asn-linked oligosaccharides: implications in biological processes

Abstract Molecular dynamics simulations of several Asn-linked oligosaccharides carried out recently have been summarized. These oligosaccharides are flexible and the core α1 → 3- and α1 → 6-linkages play important roles in determining the overall shape of the molecule. The orientation of the 1 → 6-arm is affected not only by changes in χ but also by changes in φ and ψ around the α1 → 6-linkage. The processing of Man9GlcNAc2 to Man5GlcNAc2 during the biosynthesis of Asn-linked oligosaccharides proceeds in well-defined ‘conformation driven’ pathways. These molecular dynamics studies rationalize spectroscopic and biochemical observations such as the rate of cleavage of α1 → 2-linked mannoses by α-mannosidases, the action of β-1 → 4-galactosyltransferase on biantennary oligosaccharides, and the binding affinities of oligosaccharide ligands to the asialoglycoprotein receptor.
A Bellman function proof of the L 2 bump conjecture

We approach the problem of finding the sharp sufficient condition for boundedness of all two weight Calderon-Zygmund operators. We solve this problem in L2 by writing a formula for a Bellman function of the problem.
Beyond the bulge: a fundamental relation between supermassive black holes and dark matter halos

The possibility that the masses MBH of supermassive black holes (SBHs) correlate with the total gravitational mass of their host galaxy, or the mass MDM of the dark matter halo in which they presumably formed, is investigated using a sample of 16 spiral and 20 elliptical galaxies. The bulge velocity dispersion σc, typically defined within an aperture of size R 0.5 kpc, is found to correlate tightly with the galaxy's circular velocity vc, the latter measured at distances from the Galactic center at which the rotation curve is flat, R ~ 20-80 kpc. By using the well-known MBH-σc relation for SBHs and a prescription to relate vc to the mass of the dark matter halo MDM in a standard ΛCDM cosmology, the correlation between σc and vc is equivalent to one between MBH and MDM. Such a correlation is found to be nonlinear, with the ratio MBH/MDM decreasing from 2 × 10-4 for MDM ~ 1014 M☉ to 10-5 for MDM ~ 1012 M☉. Preliminary evidence suggests that halos of mass smaller than ~5 × 1011 M☉ are increasingly less efficient at forming SBHs—perhaps even unable to form them.
Sparse potentials with fractional Hausdorff dimension

Abstract We construct non-random bounded discrete half-line Schrodinger operators which have purely singular continuous spectral measures with fractional Hausdorff dimension (in some interval of energies). To do this we use suitable sparse potentials. Our results also apply to whole line operators, as well as to certain random operators. In the latter case we prove and compute an exact dimension of the spectral measures.
Symmetry, stability, and diffraction properties of icosahedral crystals

In a remarkable experiment on an Mn-A1 alloy Shechtman et al. observed a diffraction spectrum with icosahedral symmetry. This is inconsistent with discrete translational invariance since the symmetry includes a five-fold axis. In this paper it will be shown that the crystallography and diffraction pattern can be described by a six-dimensional space group. The crystal structure in 3d is obtained as a cut along a 3d hyperplane in a regular 6d crystal. Displacements of the 6d crystal along 6 orthogonal directions define 6 continuous symmetries for the icosahedral crystal, three of which are phase symmetries describing internal rearrangements of the atoms.
A Bayesian Inference Analysis of the X-Ray Cluster Luminosity-Temperature Relation

We present a Bayesian inference analysis of the Markevitch and Allen & Fabian cooling flow-corrected X-ray cluster temperature catalogs that constrains the slope and the evolution of the empirical X-ray cluster luminosity-temperature (L-T) relation. We find that for the luminosity range 1044.5 ergs s-1 Lbol 1046.5 ergs s-1 and the redshift range z 0.5, Lbol∝T(1-z). We also determine the L-T relation that one should use when fitting the Press-Schechter mass function to X-ray cluster luminosity catalogs such as the Einstein Medium Sensitivity Survey (EMSS) and the Southern Serendipitous High-Redshift Archival ROSAT Catalog (Southern SHARC), for which cooling flow-corrected luminosities are not determined and a universal X-ray cluster temperature of T=6 keV is assumed. In this case, Lbol∝T(1+z) for the same luminosity and redshift ranges.
Real and Spurious Long-Memory Properties of Stock-Market Data

We test for the presence of long memory in daily stock returns and their squares using a robust semiparametric procedure of Lobato and Robinson. Spurious results can be produced by nonstationarity and aggregation. We address these problems by analyzing subperiods of returns and using individual stocks. The test results show no evidence of long memory in the returns. By contrast, there is strong evidence in the squared returns.
Framed knot contact homology

We extend knot contact homology to a theory over the ring Z[λ±1,μ±1] with the invariant given topologically and combinatorially. The improved invariant, which is defined for framed knots in S3 and can be generalized to knots in arbitrary manifolds, distinguishes the unknot and can distinguish mutants. It contains the Alexander polynomial and naturally produces a two-variable polynomial knot invariant that is related to the A-polynomial
Control of Platoons of Nonholonomic Vehicles Using Redundant Manipulator Analogs

in this work, we consider the control of platoons of cooperating nonholonomic vehicles. Using techniques based on redundant manipulator control, the platoon is treated as a single entity with a set of platoon-level objectives. The class of tricyclelike robots, with limits on steering and speed, is chosen because it represents a vast class of real, nonholonomic vehicles beyond the basic differential drive. The method presented uses platoon redundancy to limit the impact of vehicle constraints on the platoon-level objectives. A simulation study is presented to show the efficacy of the method.
Terrorism, Trade and Public Policy

Are bigger markets safer? How should government policy respond to terrorist threats? Trade draws potential terrorists and economic predators into productive activity, but trade also draws terrorist attacks. Larger trade reduces the risk of terrorist attack when the wage elasticity is high, associated with low ratios of predators to prey and high wages; but it may increase the risk of terrorist attack when the wage elasticity is low, associated with high ratios of predators to prey. Anti-terrorist trade policy should always promote trade in simultaneous play. Government first mover advantage and inelastic wage may imply trade restriction. Tolerance of smuggling may improve security. Better enforcement should ordinarily be provided for bigger, inherently safer and higher wage markets.
Exploring QCD: from LEAR to GSI

In this invited contribution I briefly review some of the principal topics in hadron spectroscopy that were studied at the CERN low-energy antiproton facility LEAR, from its beginnings in the early 1980s to the present. These topics include the nature of multiquark systems, the short-ranged nuclear force, and gluonic hadrons, including glueballs and hybrids. Lessons we have learned from the LEAR program that are relevant to the future GSI project are given particular emphasis.
Effects of catalyst composition on dual site zeolite catalysts used in chlorinated hydrocarbon oxidation

Abstract Cobalt exchanged and chromia impregnated Y zeolite catalysts (Co-Y/CA ) have been found to show good activity and selectivity for low-molecular-weight chlorohydrocarbon (CH 2 Cl 2 , C 2 HCl 3 , CCl 4 , etc.) oxidation in the range of 250–350°C. For such dual site catalysts, the effects of cobalt and chromia composition on the catalytic properties were investigated. Higher cobalt exchange increased the acidity and the oxygen adsorption capacity of the Co-Y zeolite without affecting the surface area, whereas increasing Cr 2 O 3 impregnation caused increased dealumination and consequent loss of acidity. Higher loading of Cr 2 O 3 also reduced catalyst surface area by combination of structural loss and pore/channel blockage. Increasing cobalt exchange produced improved conversion of methylene chloride (CH 2 Cl 2 ) while higher loading of impregnated Cr 2 O 3 was detrimental for methylene chloride conversion due to the associated loss of surface area and acidity. Methylene chloride conversion appeared to be primarily controlled by carbonium ion formation at the acidic sites followed by oxidation with the oxygen adsorbed at the cationic sites. Conversely, trichloroethylene (C 2 HCl 3 ) oxidation was primarily determined by the impregnated Cr 2 O 3 sites; low or no Cr 2 O 3 produced poor conversion while increasing Cr 2 O 3 loading increased the conversion. However, an optimum impregnation level (⋍5%) seemed to be necessary to avoid poor activity either due to lack of sites or due to structural damage by overloading. Additionally, increasing cobalt exchange level in the Co-Y/CA catalysts also showed improved TCE conversion probably due to the increasing acidity. Therefore, TCE conversion seemed to be controlled by the initial adsorption at the Cr 2 O 3 sites with subsequent reactions which may involve the acidic and/or cationic sites.