cssi/SciSciGPT-SciSciNet huggingface dataset:
DDoS defense by offense

This article presents the design, implementation, analysis, and experimental evaluation of speak-up, a defense against application-level distributed denial-of-service (DDoS), in which attackers cripple a server by sending legitimate-looking requests that consume computational resources (e.g., CPU cycles, disk). With speak-up, a victimized server encourages all clients, resources permitting, to automatically send higher volumes of traffic. We suppose that attackers are already using most of their upload bandwidth so cannot react to the encouragement. Good clients, however, have spare upload bandwidth so can react to the encouragement with drastically higher volumes of traffic. The intended outcome of this traffic inflation is that the good clients crowd out the bad ones, thereby capturing a much larger fraction of the server's resources than before. We experiment under various conditions and find that speak-up causes the server to spend resources on a group of clients in rough proportion to their aggregate upload bandwidths, which is the intended result.
Superalgebras in N=1 gauge theories

Abstract N = 1 supersymmetric gauge theories with global flavor symmetries contain a gauge invariant W-superalgebra which acts on its moduli space of gauge invariants. With adjoint matter, this superalgebra reduces to a graded Lie algebra. When the gauge group is SO ( n c ), with vector matter, it is a W-algebra, and the primary invariants form one of its representation. The same superalgebra exists in the dual theory, but its construction in terms of the dual fields suggests that duality may be understood in terms of a charge conjugation within the algebra. We extend the analysis to the gauge group E 6 .
HOW BLACK HOLES GET THEIR KICKS: GRAVITATIONAL RADIATION RECOIL REVISITED

Gravitational waves from the coalescence of binary black holes carry away linear momentum, causing center of mass recoil. This "radiation rocket" effect has important implications for systems with escape speeds of order the recoil velocity. We revisit this problem using black hole perturbation theory, treating the binary as a test mass spiraling into a spinning hole. For extreme mass ratios (q ≡ m1/m2 1), we compute the recoil for the slow in-spiral epoch of binary coalescence very accurately; these results can be extrapolated to q ~ 0.4 with modest accuracy. Although the recoil from the final plunge contributes significantly to the final recoil, we are only able to make crude estimates of its magnitude. We find that the recoil can easily reach ~100-200 km s-1 but most likely does not exceed ~500 km s-1. Although much lower than previous estimates, this recoil is large enough to have important astrophysical consequences. These include the ejection of black holes from globular clusters, dwarf galaxies, and high-redshift dark matter halos.
Embedded computer architectures in the MPSoC age

Embedded computers are no longer used as simple controllers. Instead, high-performance embedded processors perform complex algorithms and are linked together to form multiprocessors. Embedded computing provides students different take on computer system design because of the requirements imposed on these systems:• Embedded computing systems generally require real-time performance. Real-time and average-time performance are very different animals.• Battery-powered embedded systems must meet very stringent energy requirements [Aus04].• Although the software in embedded systems can be changed to optimize the overall system, the software must also meet the specifications of the application.
Temperature dependence of radial breathing mode Raman frequency of single-walled carbon nanotubes

Recent high-temperature studies of Raman-active modes in single-walled carbon nanotube (SWNT) bundles report a softening of the radial and tangential band frequencies with increasing sample temperature. A few speculations have been proposed in the past to explain the origin of these frequency downshifts. In the present study, based on experimental data and the results of molecular dynamics simulations, we estimate the contributions from three factors that may be responsible for the observed temperature dependence of the radial breathing mode frequency $[{\ensuremath{\omega}}_{\mathrm{RBM}}(T)].$ These factors include thermal expansion of individual SWNTs in the radial direction, softening of the C-C (intratubular) bonds, and softening of the van der Waals intertubular interactions in SWNT bundles. Based on our analysis, we find that the first factor plays a minor role due to the very small value of the radial thermal expansion coefficient of SWNTs. On the contrary, the temperature-induced softening of the intra- and intertubular bonds contributes significantly to the temperature-dependent shift of ${\ensuremath{\omega}}_{\mathrm{RBM}}(T).$ For nanotubes with diameters $(d)g~1.34\mathrm{nm},$ the contribution due to the radial thermal expansion is \ensuremath{\leqslant}4% over the temperature range used in this study. Interestingly, this contribution increases to \ensuremath{\geqslant}10% in the case of nanotubes having $dl~0.89\mathrm{nm}$ due to the relatively larger curvature of these nanotubes. The contributions from the softening of the intra- and intertubular bonds are approximately equal. These two factors together contribute a total of about \ensuremath{\sim}95% and 90%, respectively, for SWNTs having $dg~1.34\mathrm{nm}$ and \ensuremath{\leqslant}0.89 nm.
Prejudice, Black Threat, and the Racist Voter in the 2008 Presidential Election

We show evidence of prejudiced voting in the 2008 presidential election. We then go deeper to test whether black threat theory explains some of this behavior. The theory finds empirical support, especially in the South. We also show that black concentration in an area works interactively with the socioeconomic status of that area when eliciting white animosity against blacks. In richer areas, black threat theory finds little support, while in poorer areas it is evident.
Recent development on the modeling of electrical contact

Summary form only given. Electrical contact is an important issue to high power microwave sources, pulsed power systems, field emitters, thin film devices and integrated circuits, and interconnects, etc. Current crowding, which leads to intense local heating, is a well known phenomenon associated with contact resistance for the above areas. This paper summarizes recent development on the accurate evaluation of contact resistance for both horizontal [1-3] and vertical [3,4] contacts. By horizontal (vertical), we mean a current flow that is parallel (perpendicular) to the base of a contact member. The contact members may possess vastly different electrical resistivities, and arbitrary aspect ratios. The analytic calculations are validated by the MAXWELL codes. Current partitions in different regions are displayed. Current crowding is shown to occur within a distance of 0.44h of the rim of an electrode that is made in horizontal contact with a thin film of thickness h, regardless of the electrode shape [1,3]. A novel relation between AC bulk contact resistance and DC thin film contact resistance was discovered [3]. General scaling laws are presented.
Computing the Ehrhart quasi-polynomial of a rational simplex

We present a polynomial time algorithm to compute any fixed number of the highest coefficients of the Ehrhart quasi-polynomial of a rational simplex. Previously such algorithms were known for integer simplices and for rational polytopes of a fixed dimension. The algorithm is based on the formula relating the kth coefficient of the Ehrhart quasi-polynomial of a rational polytope to volumes of sections of the polytope by affine lattice subspaces parallel to k-dimensional faces of the polytope. We discuss possible extensions and open questions.
How to locate the electrically conducting fluid core of a planet from external magnetic observations

A NEW method is proposed here for locating the electrically conducting fluid core of a planet from external magnetic observations. When tested with the aid of geomagnetic data, the method gives for the radius of the Earth's liquid metallic core a value which differs insignificantly from the accepted value (based on seismic data). These findings have important implications for future investigations of the magnetic fields and internal structure and dynamics of the Earth, Jupiter, and other magnetic planets.
APPROXIMATELY INDEPENDENT FEATURES OF LANGUAGES

To facilitate the testing of models for the evolution of languages, the present paper offers a set of linguistic features that are approximately independent of each other. To find these features, the adjusted Rand index (R′) is used to estimate the degree of pairwise relationship among 130 linguistic features in a large published database. Many of the R′ values prove to be near zero, as predicted for independent features, and a subset of 47 features is found with an average R′ of -0.0001. These 47 features are recommended for use in statistical tests that require independent units of analysis.
Experimental investigation into passive damping enhancement for space structures

This work presents experiments conducted to verify kineticand strain-energy damping enhancement schemes for large/precision space structures. Two types of damping mechanisms were applied to a 5-m-long, 10-bay aluminum cubic box truss with a quasi-free-free suspension. Tunable proof-mass dampers were implemented with space-realizable linear electromechanical drivers. Tunable piezoelectric truss members were designed and constructed for the demonstration of resonant shunted piezoelectric damping concepts. The truss damping was measured and compared with analytical predictions. The proof-mass damper implementation was found to increase the first mode damping ratio from 0.6% of critical to 6.4% of critical with a 2.7% system mass increase. The resonant shunted piezoelectric implementation increased the first mode damping ratio to 6.0%, with a 1.9% increase in system mass.
Distinguishing particle-hole conjugated fractional quantum Hall states using quantum-dot-mediated edge transport

We study theoretically edge transport of a fractional quantum Hall liquid, in the presence of a quantum dot inside the Hall bar with well controlled electron density and Landau level filling factor \nu, and show that such transport studies can help reveal the nature of the fractional quantum Hall liquid. In our first example we study the \nu=1/3 and \nu=2/3 liquids in the presence of a \nu=1 quantum dot. When the quantum dot becomes large, its edge states join those of the Hall bar to reconstruct the edge states configuration. Taking randomness around the edges into account, we find that in the disorder-irrelevant phase the two-terminal conductance of the original \nu=1/3 system vanishes at zero temperature, while that of the \nu=2/3 case remains finite. This distinction is rooted in the fact that the \nu=2/3 state is built upon the \nu=1 state. In the disorder-dominated phase, the two-terminal conductance of \nu=1/3 system is (1/5)\frac{e^2}{h} and that of \nu=2/3 system is (1/2)\frac{e^2}{h}. We further apply the same idea to the \nu=5/2 system which realizes either the Pfaffian or the anti-Pfaffian states. In this case we study the edge transport in the presence of a central \nu=3 quantum dot. If the quantum dot is large enough for its edge states joining those of the Hall bar, in the disorder-irrelevant phase the total two-terminal conductance in the Pfaffian case is G^{Pf}_{tot}\rightarrow 2 \frac{e^2}{h} while that of anti-Pfaffian case is higher but not universal, G^{aPf}_{tot}> 2 \frac{e^2}{h}. This difference can be used to determine which one of these two states is realized at \nu=5/2. In the disorder-dominated phase, however, the total two-terminal conductances in these two systems are exactly the same, G^{Pf/aPf}_{tot}=(7/3)\frac{e^2}{h}.
Lower Bounds on Near Neighbor Search via Metric Expansion

In this paper we show how the complexity of performing nearest neighbor (NNS) search on a metric space is related to the expansion of the metric space. Given a metric space we look at the graph obtained by connecting every pair of points within a certain distance $r$ . We then look at various notions of expansion in this graph relating them to the cell probe complexity of NNS for randomized and deterministic, exact and approximate algorithms. For example if the graph has node expansion $\Phi$ then we show that any deterministic $t$-probe data structure for $n$ points must use space $S$ where $(St/n)^t > \Phi$. We show similar results for randomized algorithms as well. These relationships can be used to derive most of the known lower bounds in the well known metric spaces such as $l_1$, $l_2$, $l_\infty$, and some new ones, by simply computing their expansion. In the process, we strengthen and generalize our previous results~\cite{PTW08}. Additionally, we unify the approach in~\cite{PTW08} and the communication complexity based approach. Our work reduces the problem of proving cell probe lower bounds of near neighbor search to computing the appropriate expansion parameter. In our results, as in all previous results, the dependence on $t$ is weak, that is, the bound drops exponentially in $t$. We show a much stronger (tight) time-space tradeoff for the class of \emph{dynamic} \emph{low contention} data structures. These are data structures that supports updates in the data set and that do not look up any single cell too often. A full version of the paper could be found in [19].
First, second, and third order finite-volume schemes for advection-diffusion

In this paper, we present first, second, and third order implicit finite-volume solvers for advection-diffusion problems based on the first-order hyperbolic system method. In particular, we demonstrate that the construction of a uniformly accurate third-order advection-diffusion scheme is made trivial by the hyperbolic method while a naive construction of adding a third-order diffusion scheme to a third-order advection scheme can fail to yield third-order accuracy. We demonstrate also that the gradients are computed simultaneously to the same order of accuracy as that of the solution variable on irregular triangular grids: first, second and third order accurate gradients by the first, second, and third order schemes, respectively. Furthermore, the first and second order schemes are shown to achieve one order higher accuracy for the solution variable in the advection limit. It is also shown that these schemes are capable of producing highly accurate and smooth solution gradients along the boundary in a highly-skewed anisotropic irregular triangular grid while conventional schemes suffer from oscillations on such a grid. Numerical results show that these schemes are capable of delivering high accuracy over conventional schemes at a significantly reduced cost.
The homogeneous weight partition and its character-theoretic dual

The homogeneous weight on a finite Frobenius ring naturally induces a partition which is invariant under left and right multiplication by units. It is shown that the character-theoretic left-sided dual of this partition coincides with the right-sided dual, and even more, the left- and right-sided Krawtchouk coefficients coincide. An example is provided showing that this is not the case for general invariant partitions if the ring is not semisimple.
Function-oriented synthesis, step economy, and drug design.

This Account provides an overview and examples of function-oriented synthesis (FOS) and its increasingly important role in producing therapeutic leads that can be made in a step-economical fashion. Biologically active natural product leads often suffer from several deficiencies. Many are scarce or difficult to obtain from natural sources. Often, they are highly complex molecules and thus not amenable to a practical synthesis that would impact supply. Most are not optimally suitable for human therapeutic use. The central principle of FOS is that the function of a biologically active lead structure can be recapitulated, tuned, or greatly enhanced with simpler scaffolds designed for ease of synthesis and also synthetic innovation. This approach can provide practical access to new (designed) structures with novel activities while at the same time allowing for synthetic innovation by target design. This FOS approach has been applied to a number of therapeutically important natural product leads. For example, b...
Theoretical studies of brush-type chiral stationary phases

Atomistic molecular modeling techniques are described. A review of these methods directed toward understanding the origins of enantioselective binding on brush-type stationary phases used in chiral chromatography is presented.
Pharmacological class data representation in the Web Ontology Language (OWL)

Dozens of drug terminologies and resources capture drug and/or drug class information; they range greatly in their coverage and their adequacy of representation. However, there are no transformative ways to link these resources together in a standard and formal fashion, which hinders data integration and data representation for supporting drug-related clinical and translational studies. In this study, we generated a standardized Pharmacological Class Profile Ontology, named PCPO, which integrates multiple drug resources in the Web Ontology Language (OWL). More specifically, we mapped two well-known drug class resources, Anatomical Therapeutic Chemical classification system (ATC) and National Drug File Reference Terminology (NDF-RT), as the pharmacological class backbone. Furthermore we extended the PCPO with individual clinical drug information extracted from RxNorm and Structured Product Labeling. In parallel, we calculated and compared chemical structure similarity for each drug pair from ATC and NDF-RT, and re-grouped drugs with a similar structure into a same drug class. PCPO will not only present big drug data into well-organized formal form, OWL with possible inference capability, but also potentially support computational drug repurposing application development.
Systematics for Elastic Scattering of Elementary Particles

Abstract The function (do/dlnt)½ against (t)½ gives rise to a scaling law for elastic scattering of elementary particles on protons, for barycentral angles from 0 to 90°, and for laboratory momenta from 5 to 25 GeV/c.
The International Geophysical Year

December 31, 1958 saw the end of the great enterprise of geophysical and solar observation known as the International Geophysical Year (IGY). As it began on July 1, 1957, the “Year” was of generous length, eighteen months. The scope of the enterprise was immense, and its success was remarkable. It engaged the co-operation of sixty-seven nations, of diverse race, color, religion, and political organization. All these joined freely and harmoniously together in the scientific study of the Earth and the Sun. It gave proof that however many and serious are the political problems that trouble the human race, it is possible for the nations to work together in a great enterprise planned for the common good. Thus by example it was an encouragement to peaceful cooperation also in other fields of activity. The simplicity of the essential purpose of the IGY made a strong appeal to the many governments throughout the world, and gained for it generous financial support. It received wide publicity by press, radio, and television, and caught the imagination of a considerable part of the general public. It led to scientific study and exploration of the Antarctic Continent on a scale beyond all previous endeavor. It opened a new era in the history of humanity, by stimulating the launching of earth satellites. This undoubtedly marked a notable step towards space travel, and a beginning of great new advances in the scientific study of the cosmos.
Optical determination of the effects of a microminiature accelerometer on resonance of a small airfoil

Abstract An experiment determining the influence of a microminiature accelerometer on the resonance of a small, NACA 0015 blade is discussed. Time-average holographic interferometry and an optical proximity sensor were used to record the resonance frequency and amplitude of the blade with and without the accelerometer while the blade was excited acoustically.
Parametrized Stochastic Grammars for RNA Secondary Structure Prediction

We propose a two-level stochastic context-free grammar (SCFG) architecture for parametrized stochastic modeling of a family of RNA sequences, including their secondary structure. A stochastic model of this type can be used for maximum a posteriori estimation of the secondary structure of any new sequence in the family. The proposed SCFG architecture models RNA subsequences comprising paired bases as stochastically weighted Dyck-language words, i.e., as weighted balanced- parenthesis expressions. The length of each run of unpaired bases, forming a loop or a bulge, is taken to have a phase-type distribution: that of the hitting time in a finite-state Markov chain. Without loss of generality, each such Markov chain can be taken to have a bounded complexity. The scheme yields an overall family SCFG with a manageable number of parameters.
The Pseudo-evolution of Halo Mass

A dark matter halo is commonly defined as a spherical overdensity of matter with respect to a reference density, such as the critical density or the mean matter density of the universe. Such definitions can lead to a spurious pseudo-evolution of halo mass simply due to redshift evolution of the reference density, even if its physical density profile remains constant over time. We estimate the amount of such pseudo-evolution of mass between z = 1 and 0 for halos identified in a large N-body simulation, and show that it accounts for almost the entire mass evolution of the majority of halos with M{sub 200{rho}-bar} Less-Than-Or-Equivalent-To 10{sup 12} h{sup -1} M{sub Sun} and can be a significant fraction of the apparent mass growth even for cluster-sized halos. We estimate the magnitude of the pseudo-evolution assuming that halo density profiles remain static in physical coordinates, and show that this simple model predicts the pseudo-evolution of halos identified in numerical simulations to good accuracy, albeit with significant scatter. We discuss the impact of pseudo-evolution on the evolution of the halo mass function and show that the non-evolution of the low-mass end of the halo mass function is the result of a fortuitous cancellationmore » between pseudo-evolution and the absorption of small halos into larger hosts. We also show that the evolution of the low-mass end of the concentration-mass relation observed in simulations is almost entirely due to the pseudo-evolution of mass. Finally, we discuss the implications of our results for the interpretation of the evolution of various scaling relations between the observable properties of galaxies and galaxy clusters and their halo masses.« less
Synthesis of the four enantiomerically-pure isomers of 15-F2t-isoprostane

Abstract Syntheses of the four enantiomerically-pure isomers of 15-F2t-isoprostane are described. The key step is the lipase-mediated resolution of a pseudo-meso diol, to give the regioisomeric acetates in high enantiomeric purity. Improved procedures for the preparation of the pseudo-meso diol are also reported.
Filament instability and rotational tissue anisotropy: A numerical study using detailed cardiac models

The role of cardiac tissue anisotropy in the breakup of vortex filaments is studied using two detailed cardiac models. In the Beeler-Reuter model, modified to produce stable spiral waves in two dimensions, we find that anisotropy can destabilize a vortex filament in a parallelepipedal slab of tissue. The mechanisms of the instability are similar to the ones reported in previous work on a simplified cardiac model by Fenton and Karma [Chaos 8, 20 (1998)]. In the Luo-Rudy model, also modified to produce stable spiral waves in two dimensions, we find that anisotropy does not destabilize filaments. A possible explanation for this model-dependent behavior based on spiral tip trajectories is offered. (c) 2001 American Institute of Physics.
Pulling out all the stops: searching for RPV SUSY with stop-jets

If the lighter stop eigenstate decays directly to two jets via baryonic R-parity violation, it could have escaped existing LHC and Tevatron searches in four-jet events, even for masses as small as 100 GeV. In order to recover sensitivity in the face of increasingly harsh trigger requirements at the LHC, we propose a search for stop pairs in the highly-boosted regime, using the approaches of jet substructure. We demonstrate that the four-jet triggers can be completely bypassed by using inclusive jet-H T triggers, and that the resulting QCD continuum background can be processed by substructure methods into a featureless spectrum suitable for a data-driven bump-hunt down to 100 GeV. We estimate that the LHC 8 TeV run is sensitive to 100 GeV stops with decays of any flavor at better than 5σ-level, and could place exclusions up to 300 GeV or higher. Assuming Minimal Flavor Violation and running a b-tagged analysis, exclusion reach may extend up to nearly 400 GeV. Longer-term, the 14 TeV LHC at 300 fb−1 could extend these mass limits by a factor of two, while continuing to improve sensitivity in the 100 GeV region.
The production of narrow Σ-hypernuclear states

Abstract It has been suggested that some of the observed narrow Σ hypernuclear states may be “bound states in the continuum” of the Σ interacting with the host nucleus formed when that interaction is strongly absorptive. It is shown that the S matrix for such a process vanishes at the complex energy of such a bound state. Some general properties of the S matrix in the presence of absorption are derived.
A fast recursive algorithm for computing the discrete cosine transform

The discrete cosine transform (DCT) is widely applied in various fields, including image data compression, because it operates like the Karhunen-Loeve transform for stationary random data. This paper presents a recursive algorithm for DCT with a structure that allows the generation of the next higher order DCT from two identical lower order DCT's. As a result, the method for implementing this recursive DCT requires fewer multipliers and adders than other DCT algorithms.
Fluoroalkane aromatization over hot sodium oxalate

Abstract Hot sodium oxalate (465°C) aromatizes perfluorodecalin to give perfluorotetralin and perfluoronaphthalene. Decomposition of solid sodium oxalate at temperatures above 450°C involves initial formation of elemental carbon that catalyzes the subsequent decomposition of oxalate, leading to the presence of an induction period in the overall decomposition reaction. Prior incipient decomposition of sodium oxalate to carbon and sodium carbonate is necessary for this reagent to effect aromatization.
Antiferromagnetism in metals

Neutron diffraction studies of chromium and manganese by Shull & Wilkinson have disclosed the existence of a partial antiferromagnetic ordering in these metals, dissimilar in several respects from the antiferromagnetism which occurs in compounds such as MnF$_{2}$ and MnO. The present paper proposes a simple formulation of an energy-band theory of antiferro-magnetism based on the assumption that the magnetically effective electrons are in non-localized states. It is shown how this approach leads to an understanding of the differences between antiferromagnetic metals and antiferromagnetic compounds, which are better treated by assuming that the electrons are in localized states. In particular, it is shown why Cr and Mn do not present observable anomalies in specific heat and susceptibility at the Curie point. Finally, it is pointed out that the occurrence of antiferromagnetism in palladium may be the explanation of the gentle susceptibility maximum at 80 degrees K observed by Hoare & Mathews.
Disposing dictators, demystifying voting paradoxes

A description outlines how the material in a forthcoming book, with the same title, complements the material discussed in my article ''Complexity and the Geometry of Voting'' that appears in this issue. Book topics include explaining why several of the well-known ''impossibility'' results do not mean as previously believed, a listing of all possible positional voting paradoxes, and how to understand voting paradoxes.
Outlier Respecting Points Approximation

In this paper, we consider a generalized problem formulation of computing a functional curve to approximate a point set in the plane with outliers. The goal is to seek a solution that not only optimizes its original objectives, but also somehow accommodates the impact of the outliers. Based on a new model of accommodating outliers, we present efficient geometric algorithms for various versions of this problem (e.g., the approximating functions are step functions or piecewise linear functions, the points are unweighted or weighted, etc). All our results are first known. Our new model and techniques for handling outliers may be useful to other applications as well.
Uncertainty and the Effectiveness of Monetary and Fiscal Policies

This paper integrates the decision making of a firm facing production uncertainty into the theory of aggregate supply. This integration has two important policy implications. First, if the aggregate demand is not unitary price elastic, the presence of uncertainty reduces the aggregate supply, whether producers are risk neutral or risk averse. Second, given the assumption of decreasing absolute risk aversion an increase in interest rate reduces the aggregate supply, and hence the presence of production uncertainty reduces the effectiveness of fiscal policy whereas it increases that of monetary policy for affecting income.
Au25 nanocluster-catalyzed Ullmann-type homocoupling reaction of aryl iodides.

The Au25(SR)18/CeO2 nanocluster catalyst showed high activity in the homocoupling of aryl iodides (e.g. up to 99.8% yield with iodobenzene) and excellent recyclability.
First demonstration of a carbocation-olefin cyclization route to the lanosterol series

Abstract A silicon-assisted double carbocation-olefin cyclization reaction was used as the key step (10 → 11) in a simple, convergent and enantioselective total synthesis of lanostenol (1).
Synthesis of the carbocyclic skeleton of abyssomicins C and D.

Intramolecular Diels−Alder substrate trienyl methylenebutenolide 5 was prepared in six steps by coupling 3-methoxy-4-methylenebutenolide (6) with trienone keto aldehyde 7. Heating 5 in CHCl3 for 2 d at 70 °C afforded 80% of a single Diels−Alder adduct 4 with the complete carbon skeleton of abyssomicin C. Addition of thiophenoxide to the enone double bond of 4 followed by an intramolecular Michael addition afforded 15 with the abyssomicin D carbon skeleton.
Composition and structure of a new palladate Ca4−1.5xAuxPd4O8 (x∼0.54) synthesized at high pressure

Abstract A new palladate was synthesized at 100 kbar. Electron microprobe (EM) measurement gave the average composition as: Ca 3.20±0.15 Au 0.54±0.03 Pd 4.00±0.16 O 7.86±0.28 , suggesting Pd and Au are di- and tri-valent, respectively, in the formula of Ca 4−1.5 x Au x Pd 4 O 8 ( x ∼0.54). Rietveld refinement using powder X-ray diffraction data shows its tetragonal symmetry of space group P4 2 /mmc (No. 131), a =5.8484(2) A, c =5.5643(2) A, V =190.32(1) A 3 , and Z =1. This phase is closely related to the bronze, CaPd 3 O 4 , and the CaPt 2 O 4 phase. Structurally, Pd(II) and Au(III) ions are coordinated with nearly square-planar oxygens, while Ca atoms are located in nearly cubic oxygen environments. Au and some Ca atoms partially occupy interstitial sites in the proto-CaPt 2 O 4 -type framework. This is a typical high-pressure effect which stabilizes the first alkaline-earth-gold-palladate oxide ever reported.
Implications of a New Light Scalar Near the Bottomonium Regime

We study the decay modes of a new, light spin-0 particle, arguing that if the mass of the (pseudo)scalar is ~ 11–15 GeV, it can have an appreciable branching ratio into bottomonium, in particular the rare η b s. Using non-relativistic QCD (NRQCD), we calculate its decay rate to bottomonia for mass splittings greater than the typical momentum transfer within the bound state. It can exceed that of decays to other Standard Model fermions under the assumption of couplings proportional to those of the Standard Model. At smaller splittings, where our computational methods break down, we estimate the rate into bottomonia using data-driven methods. When the spin-0 state decays to bottomonia whose mass is too light to produce B-meson pairs, we get a qualitatively new experimental signature, decays to b-quarks invisible to b-tagging. Such a light, spinless particle can arise in extended Higgs sectors, making this channel potentially observable in decay chains initiated by the subdominant decay of a Standard Model-like Higgs to a pair of them.
Fitting the correlation function

The whole correlation function of the intensity of scattered light is usually determined from a single realization of the photocurrent. As a result, the values of the correlation function at different delay times are not statistically independent. A standard least-squares fitting procedure is not optimal for an analysis of such data. However, the benefits of mathematically rigorous but highly nonlinear and less stable methods are not known. We consider the test case of a Gaussian signal with a single-exponential correlation function without shot noise. In this case the fitting procedure, which is based on the maximum-likelihood principle for the observed signal, permits an analytical solution. We demonstrate that such a rigorous statistical analysis produces an approximately two times more-accurate result for the relaxation time than does the standard least-squares fit. This gain, however, is greatly reduced by the presence of shot noise, which introduces additional uncorrelated errors into the values of the correlation function.
A Clifford Algebra Realization of Supersymmetry and its Polyvector Extension in Clifford Spaces

It is shown explicitly how to construct a novel (to our knowledge) realization of the Poincare superalgebra in 2D. These results can be extended to other dimensions and to (extended) superconformal and (anti) de Sitter superalgebras. There is a fundamental difference between the findings of this work with the other approaches to Supersymmetry (over the past four decades) using Grassmannian calculus and which is based on anti-commuting numbers. We provide an algebraic realization of the anticommutators and commutators of the 2D super-Poincare algebra in terms of the generators of the tensor product \({Cl_{1,1}(R) \otimes \mathcal{A}}\) of a two-dim Clifford algebra and an internal algebra A whose generators can be represented in terms of powers of a 3 × 3 matrix \({\mathcal{Q}}\) , such that \({\mathcal{Q}^3 = 0}\) . Our realization differs from the standard realization of superalgebras in terms of differential operators in Superspace involving Grassmannian (anti-commuting) coordinates θ α and bosonic coordinates x μ . We conclude in the final section with an analysis of how to construct Polyvector-valued extensions of supersymmetry in Clifford Spaces involving spinor-tensorial supercharge generators \({{{\mathcal {Q}}_{{\alpha}}^{\mu_1\mu_2\ldots\mu_n}}}\) and momentum polyvectors \({P_{\mu_1\mu_2\ldots\mu_n}}\) . Clifford-Superspace is an extension of Clifford-space and whose symmetry transformations are generalized polyvector-valued supersymmetries.
User-driven sampling strategies in image exploitation:

Both visual analytics and interactive machine learning try to leverage the complementary strengths of humans and machines to solve complex data exploitation tasks. These fields overlap most significantly when training is involved: the visualization or machine learning tool improves over time by exploiting observations of the human–computer interaction. This article focuses on one aspect of the human–computer interaction that we call user-driven sampling strategies. Unlike relevance feedback and active learning sampling strategies, where the computer selects which data to label at each iteration, we investigate situations where the user selects which data are to be labeled at each iteration. User-driven sampling strategies can emerge in many visual analytics applications, but they have not been fully developed in machine learning. User-driven sampling strategies suggest new theoretical and practical research questions for both visualization science and machine learning. In this article, we identify and qua...
Enantioselective tandem O-nitroso Aldol/Michael reaction.

This communication presents studies that illustrated nitroso Diels−Alder adduct has been obtained in uniformly high enantioselectivity via a tandem nitroso aldol/Michael reaction using an amine catalyst. The regiochemical outcome of this construction is documented to be the opposite to that of the normal nitroso aldol reaction, which has been determined by X-ray analysis. The reaction of the enone with silver−BINAP catalyst has also been investigated in conjunction with the control of regiochemistry in a stepwise process.
Schubert complexes and degeneracy loci

The classical Thom-Porteous formula expresses the homology class of the degeneracy locus of a generic map between two vector bundles as an alternating sum of Schur polynomials. A proof of this formula was given by Pragacz by expressing this alternating sum as the Euler characteristic of a Schur complex, which gives an explanation for the signs. Fulton later generalized this formula to the situation of flags of vector bundles by using alternating sums of Schubert polynomials. Building on the Schubert functors of Kraand Pragacz, we introduce Schubert complexes and show that Fulton's alternating sum can be realized as the Euler characteristic of this complex, thereby providing a conceptual proof for why an alternating sum appears.
User interface design for military AR applications

Designing a user interface for military situation awareness presents challenges for managing information in a useful and usable manner. We present an integrated set of functions for the presentation of and interaction with information for a mobile augmented reality application for military applications. Our research has concentrated on four areas. We filter information based on relevance to the user (in turn based on location), evaluate methods for presenting information that represents entities occluded from the user’s view, enable interaction through a top-down map view metaphor akin to current techniques used in the military, and facilitate collaboration with other mobile users and/or a command center. In addition, we refined the user interface architecture to conform to requirements from subject matter experts. We discuss the lessons learned in our work and directions for future research.
The Witt Ring of a Curve with Good Reduction over a Non-dyadic Local Field

Abstract In this work, we present a generalization to varieties and sheaves of the fundamental ideal of the Witt ring of a field by defining a sheaf of fundamental ideals I ˜ and a sheaf of Witt rings W ˜ in the obvious way. The Milnor conjecture then relates the associated graded of W ˜ to Milnor K-theory and so allows the classical invariants of a bilinear space over a field to be extended to our setting using etale cohomology. As an application of these results, we calculate the Witt ring of a smooth curve with good reduction over a non-dyadic local field.
The essential role of information management in point-of-care/critical care testing

Laboratory medicine is undergoing tremendous change in recent years driven primarily by technology, regulations, reimbursement, and market forces. In this paradigm shift, the laboratory is under tremendous pressure to adapt to new requirements for critical care testing. Indeed, laboratories have entered the information age where chemical data is being extracted from specimens in totally automated fashion. In the past, laboratory data has played a more historical role in the care of critically ill patients, arriving at the bedside too late to be of significant use in the active, ongoing care of the patient. However, today's physicians taking care of critically ill patients now require that laboratory results are made available in real-time and, if possible, at the patient's point-of-care. Many new testing point-of-care testing (POCT) devices have been developed to address this need however often laboratories implement such distributed devices with little or no attention to the information technology requirements. In fact, as little as 10% of point-of-care testing is actually managed by the central laboratory computer hence critically importance results are not found on the patient's electronic medical record. In addition, the billing and management data for point-of-care testing is often handled manually with no plans to interface point-of-care devices to the laboratory billing and management systems. Because of recent improvements of information handling and interface capability, such shortcomings in data management are no longer acceptable. Indeed, the demands for laboratories to utilize information technology are such that those laboratories with no overall plan for data management of critical care testing will probably not survive this market-driven paradigm. We present a discussion of the various approaches to computerization of point-of-care testing including the advantages and the disadvantages of each approach.
Integration of Forward-looking Infrared (FLIR) and Traffic Information for Moving Obstacle Detection with Integrity

This paper discusses the integration of Forward-looking Infrared (FLIR) and traffic information from, for example, the Automatic Dependent Surveillance - Broadcast (ADS-B) or the Traffic Information Service-Broadcast (TIS-B). The goal of this integration method is to obtain an improved state estimate of a moving obstacle within the Field-of-View of the FLIR with added integrity. The focus of the paper will be on the approach phase of the flight. The paper will address methods to extract moving objects from the FLIR imagery and geo-reference these objects using outputs of both the onboard Global Positioning System (GPS) and the Inertial Navigation System (INS). The proposed extraction method uses a priori airport information and terrain databases. Furthermore, state information from the traffic information sources will be extracted and integrated with the state estimates from the FLIR. Finally, a method will be addressed that performs a consistency check between both sources of traffic information. The methods discussed in this paper will be evaluated using flight test data collected with a Gulfstream V in Reno, NV (GVSITE) and simulated ADS-B.
A general method for copper-catalyzed arylation of arene C-H bonds.

A general method for copper-catalyzed arylation of sp2 C−H bonds with pKaʼs below 35 has been developed. The method employs aryl halide as the coupling partner, lithium alkoxide or K3PO4 base, and DMF, DMPU, or mixed DMF/xylenes solvent. A variety of electron-rich and electron-poor heterocycles such as azoles, caffeine, thiophenes, benzofuran, pyridine oxides, pyridazine, and pyrimidine can be arylated. Furthermore, electron-poor arenes possessing at least two electron-withdrawing groups on a benzene ring can also be arylated. Two arylcopper−phenanthroline complex intermediates were independently synthesized.
How does initial public financing influence private incentives for follow-on investment in early-stage technologies?

One common rationale supporting public financing programs for small firms is that initial public investment creates incentives for follow-on private investment. However, there does not appear to be a unified statement in the literature describing how initial public investment creates incentives for follow-on private investment. Focusing on external private investors, we use a two-stage net present value model to identify four effects from initial public investment on the private decision for follow-on investment. Our empirical analysis uses a sample of non-venture backed firms entering the SBIR program to examine how reduced risk, the number of SBIR awards, and size of initial public investment influence the likelihood of follow-on venture capital investment. We find the probability of follow-on venture capital investment is more likely when firms reach Phase II of the program, is less likely as firms win multiple Phase I and Phase II awards, and is more likely as the size of initial public investment in Phase I increases.
Addition reactions of immonium benzotriazolates to acetylenic esters

Abstract 1-Dialkylaminomethylbenzotriazoles react with ethyl propiolate and dimethyl acetylenedicarboxylate by addition of the benzotriazole anion followed by the immonium cation. The benzotriazolyl group in the products undergoes facile nucleophilic displacement.
Range Counting over Multidimensional Data Streams

We consider the problem of approximate range counting over a stream of d-dimensional points. In the data stream model the algorithm makes a single scan of the data, which is presented in an arbitrary order, and computes a compact summary data structure. The summary, whose size depends on the approximation parameter e, can be used to count the number of points inside a query range within additive error en, where n is the size of the stream seen so far. We present several results, deterministic and randomized, for both rectangle and halfspace ranges.
A Random Walk with Collapsing Bonds and Its Scaling Limit

Abstract We introduce a new self-interacting random walk on the integers in a dynamic random environment and show that it converges to a pure diffusion in the scaling limit. We also find a lower bound on the diffusion coefficient in some special cases. With minor changes the same argument can be used to prove the scaling limit of the corresponding walk in ℤ d .
Fractionation of the insoluble material of Chlorella cells

Abstract A procedure is described for the fractionation of Chlorella cell material, labeled with 14C, based on solvent extraction followed by serial digestion with several enzymes, and extraction of the breakdown products following each enzymic treatment. The cell material was divided into fractions containing the following substances or their breakdown products: water- and ethanol-soluble metabolic intermediates; lipids and pigments; ribonucleic acid; deoxyribonucleic acid; proteins and polysaccharides; some radioactivity remained in the residue after extraction. There was some variation in the purity of the various fractions. Of the ethanol- and water-insoluble materials, the fractions prepared by the use of ribonuclease and proteolytic enzymes contained only those substances to be expected following treatment with these enzymes. The deoxyribonucleic acid fraction was contaminated with glucose and some unidentified substances. However, clear evidence was obtained for the incorporation of 14C into thymine, a substance characteristic of deoxyribonucleic acid. The polysaccharide fraction, after hydrolysis, contained some amino acids from residual protein, but these could easily be separated from the sugars by paper or column chromatography.