cssi/SciSciGPT-SciSciNet huggingface dataset:
Atmospheric Neutrinos and the Oscillations Bonanza

New observations with atmospheric neutrinos from the underground experiments SuperKamiokande, Soudan 2, and MACRO, together with earlier results from Kamiokande and IMB, are reviewed. The most recent observations reconfirm aspects of atmospheric flavor content and of zenith angle distributions which appear anomalous in the context of null oscillations. The anomalous trends, exhibited with high statistics in both sub-GeV and multi-GeV data of the SuperKamiokande water Cherenkov experiment, occur also in event samples recorded by the tracking calorimeters. The data are well-described by disappearance of �µ flavor neutrinos arising in oscillations with dominant two-state mixing, for which there exists a region in (sin 2 2�, �m 2 ) allowed by all experiments. In a new analysis by SuperKamiokande, �µ → �� is favored over �µ → �sterile as the dominant oscillation based upon absence of oscillation suppression from matter effects at high energies. The possibility for sub-dominant �µ → �e oscillations in atmospheric neutrinos which arises with three-flavor mixing, is reviewed, and intriguing possibilities for amplification of this oscillation by terrestrial matter-induced resonances are discussed. Developments and future measurements which will enhance our knowledge of the atmospheric neutrino fluxes are briefly noted.
On some generalizations of Batalin-Vilkovisky algebras

Abstract We define the concept of higher-order differential operators on a general noncommutative, nonassociative superalgebra A , and show that a vertex operator superalgebra (VOSA) has plenty of them, namely modes of vertex operators. A linear operator Δ is a differential operator of order ≤ r if an inductively defined ( r +1)-linear form Φ r +1 Δ with values in A is identically zero. These forms resemble the multilinear string products of Zwiebach. When A is a “classical” (i.e. supercommutative, associative) algebra, and Δ is an odd, square zero, second order differential operator on A , Φ 2 Δ defines a “Batalin-Vilkovisky algebra” structure on A . Now that a second order differential operator makes sense, we generalize this notion to any superalgebra with such an operator, and show that all properties of the classical BV bracket but one continue to hold “on the nose”. As special cases, we provide several examples of classical BV algebras, vertex operator BV algebras, and differential BV algebras. We also point out connections to Leibniz algebras and the noncommutative homology theory of Loday. Taking the generalization process one step further, we remove all conditions on the odd operator Δ to examine the changes in the basic properties of the bracket. We see that a topological chiral algebra with a mild restriction yields a classical BV algebra in the cohomology. Finally, we investigate the quantum BV master equation for 1. (i) classical BV algebras, 2. (ii) vertex operator BV algebras, and 3. (iii) generalized BV algebras, relating it to deformations of differential graded algebras.
Transductive neural decoding for unsorted neuronal spikes of rat hippocampus

Neural decoding is an important approach for extracting information from population codes. We previously proposed a novel transductive neural decoding paradigm and applied it to reconstruct the rat's position during navigation based on unsorted rat hippocampal ensemble spiking activity. Here, we investigate several important technical issues of this new paradigm using one data set of one animal. Several extensions of our decoding method are discussed.
Scattering of Superfluid Vortex Rings

The time evolution and scattering interactions of supersuid vortex rings are studied using the Gross-Pitaevskii model, in order to consider the maintenance and generation of vorticity in supersuid sows,and to compare ring dynamics in Navier-Stokes and supersuids. For a single ring, we verify previousanalytic results on stability and the value of the translation velocity. When two vortex rings scatter,we generically observe merger and subsequent breakup in cases of close approach. Depending on theinitial conditions, the Þnal state can contain zero, two, or more Þnal rings. [S0031-9007(96)00396-1]
A bureaucratic theory of flypaper effects

Abstract One well-documented pattern in local public finance is that, in comparison with what is spent out of residents' private income, a disproportionate amount of lump-sum intergovernmental aid is used to increase expenditures rather than to reduce local taxes. This paper shows how a bureaucratic model of the type suggested by Niskanen [“Bureaucracy and Representative Government,” Aldine-Atherton, Chicago, 1971 ] can be used to explain this behavior. An empirical test of the model using 115 small governments in Michigan suggests that this bureaucratic model explains capital expenditures well, while operating expenditures appear to be better explained by the standard median voter model.
NC-Audit: Auditing for network coding storage

Network coding-based storage has recently received a lot of attention in the network coding community. Independently, another body of work has proposed integrity checking schemes for cloud storage, none of which, however, is customized for network coding storage or can efficiently support repair. In this work, we bridge the gap between these currently disconnected bodies of work, and we focus on the (novel) advantage of network coding for integrity checking. We propose NC-Audit — a remote data integrity checking scheme, designed specifically for network coding-based storage cloud. NC-Audit provides a unique combination of desired properties: (i) efficient checking of data integrity (ii) efficient support for repairing failed nodes (iii) full support for modification of outsourced data and (iv) protection against information leakage when checking is performed by a third party. The key ingredient of the design of NC-Audit is a novel combination of SpaceMac, a homomorphic MAC scheme for network coding, and NCrypt, a novel CPA-secure encryption scheme that is compatible with SpaceMac. Our evaluation of a Java implementation of NC-Audit shows that an audit costs the storage node and the auditor only a few milliseconds of computation time, and lower bandwidth than prior work.
On Markov Jump Processes Imbedded at Jump Epochs and Their Queueing-Theoretic Applications

Let {Xt}t>0 be a Markov jump process and {Tn}n=0∞ a subset of the jump epochs of the process {Xt}t>0. The main results of this paper are computable formulae for the transient and invariant distributions of {XTn}n=0∞ and {XTnI}n=0∞. We also characterize when the invariant distributions of {Xt}t>0 and {XTn}n=0∞ are the same and show that in this case {Tn}n=0∞ is a Poisson process. The results are applied to a variety of discrete-slate queueing networks to obtain their state distribution as seen by customers in arrival streams, departure streams, and traffic streams on the arcs. The main conclusion drawn is that for many traffic streams, the invariant distribution seen by customers in that stream coincides with the invariant distribution of {Xt}t>0 provided the customer in motion is excluded.
A Cautionary Note on the Use of Matching to Estimate Causal Effects: An Empirical Example Comparing Matching Estimates to an Experimental Benchmark:

In recent years, social scientists have increasingly turned to matching as a method for drawing causal inferences from observational data. Matching compares those who receive a treatment to those w...
Cyclopropanes as conformationally restricted peptide isosteres. Design and synthesis of novel collagenase inhibitors

Abstract The 1,2,3-trisubstituted cyclopropane derivatives 9 and 10 were prepared as conformationally constrained analogues of the known collagenase inhibitor 8. The syntheses of 9 and 10 featured the highly enantioselective Rh2[S-MEPY]4 catalyzed cyclization of the allylic diazo ester 11 to give the lactone 13. Opening of the lactone ring of 13 with N,O-di-(p-methoxybenzyl)hydroxylamine under Weinreb conditions followed by refunctionalization, coupling of the intermediate acid 16 with 17 and deprotection led to the dipeptide analogue 9. Alternatively, the lactone ring of 13 could be opened with the protected tyrosine 21 by a novel variant of the Weinreb protocol to give directly the dipeptide analogue 22 which was then converted into 10.
Constant-round non-malleable commitments from any one-way function

We show unconditionally that the existence of commitment schemes implies the existence of constant-round non-malleable commitments; earlier protocols required additional assumptions such as collision resistant hash functions or subexponential one-way functions. Our protocol also satisfies the stronger notions of concurrent non-malleability and robustness. As a corollary, we establish that constant-round non-malleable zero-knowledge arguments for NP can be based on one-way functions and constant-round secure multi-party computation can be based on enhanced trapdoor permutations; also here, earlier protocols additionally required either collision-resistant hash functions or subexponential one-way functions.
Determinants of Board Participation in the Strategic Decisions of Small Corporations

Agency, strategic choice, and cognitive perspectives are used to examine the conditions under which chief executive officers (CEOs) of small private corporations involve the board of directors in s...
Two new approximate methods for analyzing free vibration of structural components

Two approximate methods, which have not previously been used for structural dynamics problems, are applied to the free vibration analysis of various structural components. The first method is a new version of the complementary energy method. It is shown to be considerably more accurate than the conventional Rayleigh and Rayleigh-Schmidt methods when applied to spatially one-dimensional free vibration problems: prismatic and tapered bars, prismatic beams, and axisymmetric motion of circular membranes. The second method is the differential quadrature method introduced by Bellman and his associates. It is applied successfully here to all of the problems mentioned plus square membranes and circular and square plates.
Quasi-exactly solvable quartic potential

A new two-parameter family of quasi-exactly solvable quartic polynomial potentials is introduced. Heretofore, it was believed that the lowest-degree one-dimensional quasi-exactly solvable polynomial potential is sextic. This belief is based on the assumption that the Hamiltonian must be Hermitian. However, it has recently been discovered that there are huge classes of non-Hermitian, -symmetric Hamiltonians whose spectra are real, discrete, and bounded below. Replacing hermiticity by the weaker condition of symmetry allows for new kinds of quasi-exactly solvable theories. The spectra of this family of quartic potentials discussed here are also real, discrete and bounded below and the quasi-exact portion of the spectra consists of the lowest J eigenvalues. These eigenvalues are the roots of a Jth-degree polynomial.
Transition State Spectroscopy

Before reactants become products in a chemical reaction, they pass through an intermediate condition called the transition state. Because it lasts for a short time, the transition state is hard to observe. In his Perspective, Neumark describes results reported by Wenthold et al ., on page 1456, in which lasers were used to create the transition state and probe its energy level.
Rhodopsin photoactivation dynamics revealed by quasi-elastic neutron scattering

Rhodopsin is a G-protein-coupled receptor (GPCR) responsible for vision under dim light conditions. During rhodopsin photoactivation, the chromophore retinal undergoes cis-trans isomerization, and subsequently dissociates from the protein yielding the opsin apoprotein [1]. What are the changes in protein dynamics that occur during the rhodopsin photoactivation process? Here, we studied the microscopic dynamics of the dark-state rhodopsin and the ligand-free opsin using quasi-elastic neutron scattering (QENS). The QENS technique tracks the individual hydrogen atom motions in the protein molecules, because the neutron scattering cross-section of hydrogen is much higher than other atoms [2-4]. We used protein (rhodopsin/opsin) samples with CHAPS detergent hydrated with heavy water. The solvent signal is suppressed due to the heavy water, so that only the signals from proteins and detergents are detected. The activation of proteins is confirmed at low temperatures up to 300 K by the mean-square displacement (MSD) analysis. Our QENS experiments conducted at temperatures ranging from 220 K to 300 K clearly indicate that the protein dynamic behavior increases with temperature. The relaxation time for the ligand-bound protein rhodopsin was longer compared to opsin, which can be correlated with the photoactivation. Moreover, the protein dynamics are orders of magnitude slower than the accompanyingmore » CHAPS detergent, which forms a band around the protein molecule in the micelle. Unlike the protein, the CHAPS detergent manifests localized motions that are the same as in the bulk empty micelles. Furthermore QENS provides unique understanding of the key dynamics involved in the activation of the GPCR involved in the visual process.« less
Direct Observations of Sigma Phase Formation in Duplex Stainless Steels Using In-Situ Synchrotron X-Ray Diffraction

The formation and growth of sigma (σ) phase in 2205 duplex stainless steel (DSS) was observed and measured in real time using synchrotron radiation during 10 hour isothermal heat treatments at temperatures between 700 °C and 850 °C. Sigma formed in near-equilibrium quantities during the isothermal holds, starting from a microstructure which contained a balanced mixture of metastable ferrite and austenite. In-situ synchrotron diffraction continuously monitored the transformation, and these results were compared to those predicted by thermodynamic calculations. The data were further analyzed using a modified Johnson–Mehl–Avrami–Kolmogrov (JMAK) approach to determine kinetic parameters for sigma formation over this temperature range. The initial JMAK exponent, n, at low fractions of sigma was found to be approximately 7.0; however, toward the end of the transformation, n decreased to values of approximately 0.75. The change in the JMAK exponent was attributed to a change in the transformation mechanism from discontinuous precipitation with increasing nucleation rate, to growth of the existing sigma phase after nucleation site saturation occurred. Because of this change in mechanism, it was not possible to determine reliable values for the activation energy and pre-exponential terms for the JMAK equation. While cooling back to room temperature, the partial transformation of austenite resulted in a substantial increase in the ferrite content, but sigma retained its high-temperature value to room temperature.
Direct, Stereoselective Substitution in [Rh(CO)2Cl]2-Catalyzed Allylic Alkylations of Unsymmetrical Substrates

[Rh(CO)2Cl]2 has been found to possess the unusual property of catalyzing allylic alkylations of unsymmetrical allylic carbonates with high levels of regioselectivity to provide products arising from substitution at the carbon atom bearing the leaving group, irrespective of the structure of the starting carbonate. The substitution reaction occurs with retention of stereochemistry at the reacting center, and the carbon−carbon double-bond stereochemistry of primary (Z)-allylic carbonates is maintained.
Commitment Mechanisms and Compliance with Health-Protecting Behavior: Preliminary Evidence from Orissa, India

This paper presents results that are part of a larger study carried out in five districts of the eastern Indian state of Orissa, where endemic malaria represents one of the most serious public health concerns. One of the Study's objectives, designed in collaboration with the micro-lender Bharat Integrated Social Welfare Agency, was to evaluate the possibility of using specifically designed consumer loan contracts to increase ownership and retreatment rates for insecticide-treated bednets.
Lumped parameter modeling of the actuator behavior of ferrogels

Ferrogels are compliant composite materials formed of a soft polymer matrix with a filler of magnetic powder. The interaction of the magnetic filler with an applied magnetic field causes the deformation of the ferrogel. Strains of up to 40% have been measured with load capabilities of up to four times the sample's weight. As these materials move toward application it is important to capture the actuator behavior in mathematical models so that materials can be designed and the behavior predicted. In this work experimental testing captures the strain and strain rate behavior of these materials at fields up to 0.5 T. A lumped parameter model is then developed that is much less computationally intensive than existing modeling approaches. The ability of this model to capture the behavior of interest will be assessed.
Modulation of Ligand Fluorescence by the Pt(II)/Pt(IV) Redox Couple

Abstract The dangling carboxylic acid moiety of the known platinum(II) complex, [Pt(edma)Cl2] (edma = ethylenediaminemonoacetic acid), was functionalized via amide coupling chemistry with benzyl amine and dansyl ethylenediamine to afford the derivatives [Pt(edBz)Cl2] (1) and [Pt(edDs)Cl2] (2). Subsequent oxidation of these platinum(II) complexes with iodobenzene dichloride in DMF yielded the respective platinum(IV) analogs, [Pt(edBz)Cl4] (3) and [Pt(edDs)Cl4] (4). All four platinum complexes were characterized by multinuclear NMR spectroscopy, IR spectroscopy, electrospray ionization mass spectrometry, and elemental analysis. In addition, compounds 1 and 3 were structurally characterized by X-ray crystallography. The photophysical properties of the compounds bearing the fluorescent dansyl moiety, 2 and 4, were evaluated. The emission quantum yields of 2 and 4 in DMF are 27% and 1.6%, respectively. This large difference in emission efficiency indicates that the platinum(IV) center in 4 is more effective at quenching the dansyl-based fluorescence than the platinum(II) center in 2. Time-dependent density functional theory calculations indicate that 4 has several low-lying singlet excited states that energetically lie below the primary radiation-accessible excited state of the dansyl fluorophore. These low-energy excited states may offer non-radiative decay pathways that lower the overall emission quantum yield. Treatment of 4 with biologically relevant reducing agents in pH 7.4 phosphate-buffered saline induces a 6.3-fold increase in emission intensity. These results demonstrate that 4 and future derivatives thereof may be useful for imaging the reduction of platinum(IV) complexes in living systems, chemistry of importance for evolving platinum-based anticancer drug strategies.
Wolverines: standard cell placement on a network of workstations

The authors point out that a typical computer-aided design environment consists of a number of workstations connected together by a high-speed local area network. A placement program that makes use of this distributed computing environment to achieve linear speedup without sacrificing the quality of the results obtained by the serial version of the program is presented. The placement program is based on the genetic algorithm, which is a heuristic search method inspired by biological evolution models. The parallel implementation has other desirable features such as the ability to operate in a heterogeneous network environment and dynamic and static load balancing. The implementation of the placement program and detailed experimental studies of the behavior of the algorithm with various parameter settings, network capabilities, and communication patterns are described. >
A practical stereoselective synthesis of (2R,3S)-alloisoleucine

Abstract An efficient asymmetric Strecker synthesis of the unnatural α-amino acid, d -alloisoleucine (3), from commercially available and inexpensive (S)-2-methyl-1-butanol (4) was accomplished in four steps.
Dietary Antioxidant Vitamins and Death from Coronary Heart Disease in Postmenopausal Women

Background The role of dietary antioxidant vitamins in preventing coronary heart disease has aroused considerable interest because of the knowledge that oxidative modification of low-density lipoprotein may promote atherosclerosis. Methods We studied 34,486 postmenopausal women with no cardiovascular disease who in early 1986 completed a questionnaire that assessed, among other factors, their intake of vitamins A, E, and C from food sources and supplements. During approximately seven years of follow-up (ending December 31, 1992), 242 of the women died of coronary heart disease. Results In analyses adjusted for age and dietary energy intake, vitamin E consumption appeared to be inversely associated with the risk of death from coronary heart disease. This association was particularly striking in the subgroup of 21,809 women who did not consume vitamin supplements (relative risks from lowest to highest quintile of vitamin E intake, 1.0, 0.68, 0.71, 0.42, and 0.42; P for trend = 0.008). After adjustment for p...
Radioactive heat sources in the lunar interior

Published models for the moon's thermal history typically imply present day central temperatures far too high to be consistent with the recently proposed lunar temperature profile of Sonett et al. (1971). Furthermore, chemical data on Apollo samples show that the moon is depleted relative to chondrites in volatile elements, and possibly enriched relative to chondrites in refractory elements. Additional thermal models have therefore been investigated in order to set upper limits on lunar radioactivity consistent with the proposed temperature distribution. For an initially cold, uniform moon, devoid of potassium, a maximum uranium content of 23 parts per billion is inferred.
Inequality averse collective choice

Abstract The Lorenz–Pareto optimal frontier of a collective choice problem identifies a subset of all Pareto optimal outcomes which are not inegalitarian according to the Lorenz criterion. An inequality averse choice function must thus be Lorenz–Pareto optimal in the sense that it should never `choose' an outcome outside the Lorenz–Pareto frontier of any choice problem. We study the basic properties of the Lorenz–Pareto optimal choice functions and, in particular, obtain necessary and sufficient conditions for rationalizability and representability of such choice functions. Several applications to the theory of Nash bargaining are also outlined.
INTERPRETING NEAR-INFRARED HYDROGEN LINE RATIOS IN T TAURI STARS

In accreting young stars, one of the prominent spectral features in the near-infrared is the Paschen and Brackett series in emission. We examine hydrogen line ratios for 16 classical T Tauri stars from SpeX spectra and assess the trends with veiling and accretion. The observed line ratios are compared with two theoretical models for line formation: (1) Baker & Menzel's Case B for radiative ionization and recombination and (2) a set of local line excitation calculations designed to replicate the conditions in T Tauri winds and magnetic accretion columns (KF). While the comparison between Case B and observed line ratios implies a wide range in electron density and temperature among the hydrogen line formation regions in T Tauri stars, the predictions of the local line excitation models give consistent results across multiple diagnostics. Under the assumptions of the local line excitation calculations, we find that n_H in the hydrogen line formation region is constrained to 2 × 10^(10)-2 × 10^(11) cm^(–3), where stars with higher accretion rates have densities at the higher end of this range. Because of uncertainties in extinction, temperature is not well delineated, but falls within the range expected for collisional excitation to produce the line photons. We introduce new diagnostics for assessing extinction based on near-infrared hydrogen line ratios from the local line excitation calculations.
Fibered Transverse Knots and the Bennequin Bound

We prove that a nicely fibered link (by which we mean the binding of an open book) in a tight contact manifold (M, ξ) with zero Giroux torsion has a transverse representative realizing the Bennequin bound if and only if the contact structure it supports (since it is also the binding of an open book) is ξ. This gives a geometric reason for the non-sharpness of the Bennequin bound for fibered links. We also give the classification, up to contactomorphism, of maximal self-linking number links in these knot types. Moreover, in the standard tight contact structure on S 3 we classify, up to transverse isotopy, transverse knots with maximal self-linking number in the knot types given as closures of positive braids and given as fibered strongly quasi-positive knots. We derive several braid theoretic corollaries from this. In particular, we give conditions under which quasi-positive braids are related by positive Markov stabilizations and when a minimal braid index representative of a knot is quasi-positive. Finally, we observe that our main result can be used to show, and make rigorous the statement, that contact structures on a given manifold are in a strong sense classified by the transverse knot theory they support.
Commercializing the laboratory: Faculty patenting and the open science environment

This paper investigates the relationship between patenting and publication of research results by university faculty members. Our study adds to the limited evidence on this topic with an empirical investigation based on a panel data set for a broad sample of university researchers. Results suggest that publication and patenting are complementary, not substitute, activities for faculty members. This is not consistent with recent concerns regarding deleterious effects of patenting on the research output of faculty members. Average citations to publications, however, appear to decline for repeat patenters, suggesting either a decrease in quality or restrictions on use associated in patent protection.
Au/Cr Sputter Coating for the Protection of Alumina During Sliding at High Temperatures

A sputter-deposited bilayer coating of gold and chromium was investigated as a potential solid lubricant to protect alumina substrates in applications involving sliding at high temperatures. The lubricant was tested in a pin-on-disk tribometer with coated alumina disks sliding against uncoated alumina pins. Three test parameters—temperature, load and sliding velocity—were varied over a wide range in order to determine the performance envelope of the Au/Cr solid lubricant film. The tribo-tests were run in air at temperatures of 25° to 1000°C, under loads of 4.9 to 49.0 N and at sliding velocities from 1 to 15 ms−1. Posttest analyses included surface profilometry, wear factor determination and SEM/EDS examination of worn surfaces. Compared to unlubricaled Al2O3 sliding, the use of the Au/Cr film reduced friction by 30 to 50 percent and wear by one to two orders of magnitude. Increases in test temperature resulted in lower friction and the Au/Cr film continued to provide low friction, about 0.3, even at 1000...
Convergence of frozen Gaussian approximation for high-frequency wave propagation

The frozen Gaussian approximation provides a highly efficient computational method for high-frequency wave propagation. The derivation of the method is based on asymptotic analysis. In this paper, for general linear strictly hyperbolic systems, we establish the rigorous convergence result for frozen Gaussian approximation. As a byproduct, higher-order frozen Gaussian approximation is developed. © 2011 Wiley Periodicals, Inc.
Integration on Artin toric stacks and Euler characteristics

There is a well developed intersection theory on smooth Artin stacks with quasi-affine diagonal. However, for Artin stacks whose diagonal is not quasi-finite the notion of the degree of a Chow cycle is not defined. In this paper we propose a definition for the degree of a cycle on Artin toric stacks whose underlying toric varieties are complete. As an application we define the Euler characteristic of an Artin toric stack with complete good moduli space - extending the definition of the orbifold Euler characteristic. An explicit combinatorial formula is given for 3-dimensional Artin toric stacks.
A bit of secrecy for Gaussian source compression

In this paper, the compression of an independent and identically distributed Gaussian source sequence is studied in an unsecure network. Within a game theoretic setting for a three-party noiseless communication network (sender Alice, legitimate receiver Bob, and eavesdropper Eve), the problem of how to efficiently compress a Gaussian source with limited secret key in order to guarantee that Bob can reconstruct with high fidelity while preventing Eve from estimating an accurate reconstruction is investigated. It is assumed that Alice and Bob share a secret key with limited rate. Three scenarios are studied, in which the eavesdropper ranges from weak to strong in terms of the causal side information she has. It is shown that one bit of secret key per source symbol is enough to achieve perfect secrecy performance in the Gaussian squared error setting, and the information theoretic region is not optimized by joint Gaussian random variables.
ROBUST FAULT DETECTION AND ISOLATION IN MOBILE ROBOT

Abstract Robust nonlinear analytical redundancy (RNLAR) technique is used to detect and isolate actuator and sensor faults in a mobile robot. Both model-plant-mismatch (MPM) and process disturbance are considered during fault detection. The RNLAR is used to design primary residual vectors (PRV), which are highly sensitive to the faults and less sensitive to MPM and process disturbance, for sensor and actuator fault detection. The PRVs are transformed into set of structured residual vectors (SRV) for fault isolation. Experimental results on a Pioneer 3-DX are presented to justify the effectiveness of the RNLAR scheme.
A magnetic device for computer graphic input

Recent work on systems to facilitate the input of graphical information to a computer has resulted in the development of the light pen and the Rand tablet. Both of these devices allow a user to "write" on a flat surface with a special, hand-held electronic pen. Periodically, the pen position is detected and converted into a machine-readable address. In this way, the pattern which is traced out by the pen is directly converted into binary code and stored in the machine. Devices such as these promote the easy input of graphical data such as curves, maps, diagrams, and other drawings. They should also be of interest to many researchers concerned with character and pattern recognition.
Towards a Real-time Transient Classification Engine

Temporal sampling does more than add another axis to the vector of observables. Instead, under the recognition that how objects change (and move) in time speaks directly to the physics underlying astronomical phenomena, next-generation wide-field synoptic surveys are poised to revolutionize our understanding of just about anything that goes bump in the night (which is just about everything at some level). Still, even the most ambitious surveys will require targeted spectroscopic follow-up to fill in the physical details of newly discovered transients. We are now building a new system intended to ingest and classify transient phenomena in near real-time from high-throughput imaging data streams. Described herein, the Transient Classification Project at Berkeley will be making use of classification techniques operating on"features" extracted from time series and contextual (static) information. We also highlight the need for a community adoption of a standard representation of astronomical time series data (i.e.,"VOTimeseries").
Feedbacks affecting the response of the thermohaline circulation to increasing CO2: a study with a model of intermediate complexity

A three-dimensional ocean model with an idealized geometry and coarse resolution coupled to a two-dimensional (zonally averaged) statistical-dynamical atmospheric model is used to simulate the response of the thermohaline circulation to increasing CO2 concentration in the atmosphere. The relative roles of different factors in the slowing down and recovery of the thermohaline circulation were studied by performing simulations with ocean only and partially coupled models. The computational efficiency of the model allows an extensive and thorough study of the causes of changes in the strength of the thermohaline circulation, through a large number of extended runs. The evolution of the atmosphere-to-ocean surface heat fluxes is shown to be the dominant factor in causing the weakening of the circulation in response to an increasing external forcing as well as in controlling the subsequent recovery. The feedback between heat flux and the sea surface temperature is necessary for the ocean circulation to recover. The rate of the recovery, however, is not sensitive to the magnitude of the feedback, and changes in the atmosphere, while contributing to the recovery, play a secondary role. In the case of very strong feedback, substantial changes in the SST structure are shown not to be a necessary condition for the recovery of the circulation. Subsurface changes in the density structure accompany recovery despite nearly fixed SST in one of the uncoupled experiments. Changes in the zonal distribution of heat fluxes serve as a positive feedback for both decrease and recovery of the meridional overturning, and are as important as changes in the zonal-mean values of heat fluxes. The secondary role of the moisture fluxes is explained by a smaller magnitude of their contribution to the surface buoyancy flux. Imposing amplified changes in the moisture fluxes leads to a significant slow down of the circulation, accompanied, however, by changes in the heat flux. The changed heat flux, in its turn, makes a significant contribution to the future slow down. This feedback complicates the evaluation of the relative roles of the different fluxes.
Strings and D-branes at high temperature

Abstract The thermodynamics of a gas of strings and D-branes near the Hagedorn transition is described by a coupled set of Boltzmann equations for weakly interacting open and closed long strings. The resulting distributions are dominated by the open string sector, indicating that D-branes grow to fill space at high temperature.
Enantioselective synthesis of α-hydroxy phosphonates via oxidation with (camphorsulfonyl)oxaziridines

Abstract Reaction of phosphonate anions with enantiomerically pure (camphorsulfonyl)oxaziridines results in formation of nonracemic α-hydroxy phosphonates. This enantioselective hydroxylation methodology provides convenient access to optically active α-hydroxy phosphonates and their corresponding phosphonic acids.
Synthesis of a novel series of topographically constrained amino acids: Benzo-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acids

Abstract A novel series of benzo-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acids (benzoTic, Figure 1), designed by extending the aromatic system of Tic (Tic = 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) in three different orientations, has been synthesized.
Monte Carlo simulations of an impurity-band model for III-V diluted magnetic semiconductors

We report the results of a Monte Carlo study of a model of (III,Mn)V diluted magnetic semiconductors which uses an impurity band description of carriers coupled to localized Mn spins and is applicable for carrier densities below and around the metal-insulator transition. In agreement with mean-field studies, we find a transition to a ferromagnetic phase at low temperatures. We compare our results for the magnetic properties with the mean-field approximation, as well as with experiments, and find favorable qualitative agreement with the latter. The local Mn magnetization below the Curie temperature is found to be spatially inhomogeneous, and strongly correlated with the local carrier charge density at the Mn sites. The model contains fermions and classical spins, and hence we introduce a perturbative Monte Carlo scheme to increase the speed of our simulations.
Slum Clearance and Urban Renewal in the United States

Abstract We study the local effects of a federal program that helped cities clear areas for redevelopment, rehabilitate structures, complete city plans, and enforce building codes. We use an instru...
Polaron-like vortices, dissociation transition, and self-induced pinning in magnetic superconductors

Vortices in magnetic superconductors polarize spins nonuniformly and repolarize them when moving. At a low spin relaxation rate and at low bias currents, vortices carrying magnetic polarization clouds become polaron-like and their velocities are determined by the effective drag coefficient that is significantly bigger than the Bardeen-Stephen (BS) one. As the current increases, vortices release polarization clouds and the velocity as well as the voltage in the I–V characteristics jump to values corresponding to the BS drag coefficient at a critical current Jc. The nonuniform components of the magnetic field and magnetization drop as the velocity increases, resulting in weaker polarization and a discontinuous dynamic dissociation depinning transition. Experimentally, the jump shows up as a depinning transition and the corresponding current at the jump is the depinning current. As the current decreases, on the way back, vortices are retrapped by polarization clouds at the current Jr < Jc. As a result, the polaronic effect suppresses dissipation and enhances the critical current. Borocarbides (RE)Ni2B2C with a short penetration length and highly polarizable rare earth spins seem to be optimal systems for a detailed study of vortex polaron formation by measuring I–V characteristics. We also propose to use a superconductor-magnet multilayer structure to study polaronic mechanism of pinning with the goal to achieve high critical currents. The magnetic layers should have large magnetic susceptibility to enhance the coupling between vortices and magnetization in magnetic layers while the relaxation of the magnetization should be slow. For Nb and a proper magnet multilayer structure, we estimate the critical current density Jc ∼ 109 A/m2 at the magnetic field B ≈ 1 T.
The roles of artificial intelligence in information systems

By classifying information processing tasks which are suitable for artificial intelligence approaches we determine an architectural structure for large systems. We visualize a three-layer architecture of private applications, mediating information servers, and an infrastructure which provides information resources. The base information resources are likely to use algorithmic techniques, since they will deal with many similar base objects. Their results are at higher level of abstraction, diverse, and fewer in number. The information servers must consider the scope, assumptions, and meaning of those intermediate results. Such processing will require techniques grounded in artificial intelligence concepts. Applications will need artificial intelligence techniques to augment the human interface and provide high-level decision support. Information processing in the intermediate layer is domain-specific and a module is constrained to a single ontology. Processing here is comprised of search and control of search, focusing, pruning, fusion, and other means of data reduction. There are also control tasks associated with effective resource management. Their results are then composable by higher-level applications, which have to solve problems involving multiple subtasks. The architecture presented here is a generalization of a server-client model. The mediating server modules will need a machine-friendly interface to support the application layer. The partitioning enhances maintainability, but raises questions of effectiveness and efficiency. Without new and composable structures we will be stuck with a mixture of obsolete large systems and isolated new applications. A formal partitioning provides a model where subproblems become accessible to research. Interoperation is now a distinct source of research problems. We identify some of these issues, and hope that composability of solutions will permit progress in building effective large systems.
THE ASSEMBLY OF SUPERMASSIVE BLACK HOLES AT HIGH REDSHIFTS

The supermassive black holes (SMBHs) massive enough ( few ×109 M ☉) to power the bright redshift z ≈ 6 quasars observed in the Sloan Digital Sky Survey (SDSS) are thought to have assembled by mergers and/or gas accretion from less massive "seed" BHs. If the seeds are the ~102 M ☉ remnant BHs from the first generation of stars, they must be in place well before redshift z = 6, and must avoid being ejected from their parent protogalaxies by the large (several ×102 km s–1) kicks they suffer from gravitational-radiation-induced recoil during mergers with other BHs. We simulate the SMBH mass function at redshift z > 6 using dark matter halo merger trees, coupled with a prescription for the halo occupation fraction, accretion histories, and radial recoil trajectories of the growing BHs. Our purpose is (1) to map out plausible scenarios for successful assembly of the z ≈ 6 quasar BHs by exploring a wide region of parameter space, and (2) to predict the rate of low-frequency gravitational wave events detectable by the Laser Interferometer Space Antenna (LISA) for each such scenario. Our main findings are as follows: (1) ~100 M ☉ seed BHs can grow into the SDSS quasar BHs without super-Eddington accretion, but only if they form in minihalos at z 30 and subsequently accrete 60% of the time; (2) the scenarios with optimistic assumptions required to explain the SDSS quasar BHs overproduce the mass density in lower mass (few ×105 M ☉ M bh few × 107 M ☉) BHs by a factor of 102-103, unless seeds stop forming, or accrete at a severely diminished rates or duty cycles (e.g., due to feedback), at z 20-30. We also present several successful assembly models and their LISA detection rates, including a "maximal" model that gives the highest rate (~30 yr–1 at z = 6) without overproducing the total SMBH density.
Cancellation of infrared divergences in thermal QED

Abstract As a preliminary step, the radiation produced by a classical charged current coupled to a quantized A μ is solved. To each order in α, all infrared divergences cancel between the virtual γ'3 and the real γ's absorbed from the plasma or emitted into the plasma. When all orders of perturbation theory are summed, the finite answer predicts a suppression of radiation with ω αtT . The analysis of QED then consists of two steps. First, a general probability at T ≠ 0 is organized so that all the virtual e ± , γ are in the amplitudes and all the real e ± , γ are in the phase space integrations. Next, the cancellations of IR divergences between virtual and real are demonstrated.
Synthesis and structure of a 5,15-bis(4-pyridyl)purpurin

Abstract Base catalyzed cyclization of a 5,15-di(4-pyridyl)octaalkylporphyrin-5-acrylate 6 yields smoothly the corresponding purpurin 2 . Quaternization with methyl iodide yielded the corresponding cationic N,N′-dimethylpyridiniumpurpurin 3 ; X-ray crystallography of purpurin 2 , the first purpurin to be studied crystallographically, shows the two β-alkyl groups on the saturated ring of the purpurin have a syn configuration, and the macrocycle to have a slight saddle shape with a mean deviation of 0.230 A from the least-squares plane calculated for the core atoms.
Summary talk at the 3rd KEK topical conference on CP violation

Abstract A summary of the contributions to this topical conference is presented. The topics discussed ranged from detailing what we know about CP violation, to what we hope to learn in the future, to still unsolved mysteries in the subject.
The gluon propagator

Abstract We discuss the current state of what is known non-perturbatively about the gluon propagator in QCD, with emphasis on the information coming from lattice simulations. We review specification of the lattice Landau gauge and the procedure for calculating the gluon propagator on the lattice. We also discuss some of the difficulties in non-perturbative calculations – especially Gribov copy issues. We trace the evolution of lattice simulations over the past dozen years, emphasizing how the improvement in computations has led not only to more precise determinations of the propagator, but has allowed more detailed information about it to be extracted.
Semiclassical description of inelastic atom scattering by surfaces

Inelastic scattering of atoms of moderate energies (say<5 eV) by solid surfaces is almost entirely due to energy exchange with lattice vibrations. It can give valuable information about the atom-surface interaction potential and the vibrational dynamics at surfaces. Theoretically this process represents a challenging many-body problem, calling for suitable approximation methods. Work in progress (K. Burke, L. D. Chang, and W. Kohn) is described. (1) We have solved a simple model problem in which the normal modes of the lattice are schematized by a single one-dimensional harmonic oscillator, initially in its ground state (T=0). The classical solution gives a unique energy loss. We have calculated the leading quantum correction and find a Gaussian final energy distribution whose width is proportional toh1/2. Our exact results are in general different from the so-called trajectory approximation. (2) We are about to propose a new type of atom-surface scattering experiment, which will provide a direct measure of the quantum corrections to classical scattering.
Selective, chemical epilation in the treatment of tinea capitis as contrasted with the diffuse x-ray epilation.

After almost a decade of practical experience with the selective, chemical epilation as a most advanced method in the treatment of tinea capitis, a progress report is presented. The author's additional material covered 153 more cases of tinea microsporina, while DoctorGimby's material encompassed 849 cases during an epidemic of tinea microsporina at Sault St. Marie, Ontario, Canada.
Nebular or parent body alteration of chondritic material: Neither or both?

— Discussions of meteorite properties often concern whether they are the result of “nebular” or “parent body” processes, but several decades of research have not resolved the issue. Part of the problem is that any gas-phase reaction involving meteoritic materials thought to have occurred is automatically assumed to be nebular, even though the most primitive solar system objects are water- and volatile-rich and could easily generate vapors. Reactions important in meteorite genesis are those involving (1) oxidation of Fe, (2) oxidation of other cations, (3) reduction, (4) olivine-pyroxene equilibria, and (5) hydration of silicates. The P-T-x conditions required are almost invariably incompatible with standard models for the early solar nebula, but clearly many of these reactions occurred prior to final agglomeration. Most of the reactions require high pressures (>10−3 atm) or, more importantly, major departures from cosmic composition, even though the final rocks are remarkably cosmic in elemental proportions. We suggest that most of these reactions occurred in a regolith rendered “dynamic” by the flow of copious volatiles. In such a scenario, liquid and gas phase reactions can occur at elevated temperatures and pressures relative to the nebula and with noncosmic gas phase compositions; but the system is “closed” to most components, so that cosmic proportions are essentially preserved.
Remarkably facile hexatriene electrocyclizations as a route to functionalized cyclohexenones via ring expansion of cyclobutenones.

This Communication describes a cascade reaction sequence that leads to highly functionalized cyclohexenones starting from reaction of cyclobutenones with α-lithio-α,β-unsaturated sulfones and amides. The hexatriene−cyclohexadiene cyclization steps presumed to be involved in these transformations are among the most facile hexatriene electrocyclizations reported thus far.