cssi/SciSciGPT-SciSciNet huggingface dataset:
Informed Trading and Portfolio Returns

We solve a multi-period model of strategic trading with long-lived information in multiple assets with correlated innovations in fundamental values. Market makers in each asset can only condition their price functions on trading in the that asset (but not on trading in the other asset). Using daily non-public data from the New York Stock Exchange we test the model’s predictions on the lead-lag relations of institutional order ∞ows and returns within portfolios. We flnd support for the model prediction of positive autocorrelations in portfolio returns as well as the predictions for how informed order ∞ow positively predicts future returns and future informed order ∞ow. As the model predicts we flnd these relations strengthen for portfolios formed from assets with higher correlation of fundamental values.
Electronic journals and legitimate media in the systems of scholarly communication

While the number of electronic scholarly journals is growing steadily, these journals have not yet been accepted as legitimate publication outlets by the scholarly communities. This article examines how moving from paper to electronic distribution alters the legitimacy and perceived quality of journals. It also examines the prospects for creating diverse high‐quality electronic journals in the next two decades.
Force-induced denaturation of RNA.

Abstract We quantitatively describe an RNA molecule under the influence of an external force exerted at its two ends as in a typical single-molecule experiment. Our calculation incorporates the interactions between nucleotides by using the experimentally determined free energy rules for RNA secondary structure and models the polymeric properties of the exterior single-stranded regions explicitly as elastic freely jointed chains. We find that despite complicated secondary structures, force-extension curves are typically smooth in quasi-equilibrium. We identify and characterize two sequence/structure-dependent mechanisms that, in addition to the sequence-independent entropic elasticity of the exterior single-stranded regions, are responsible for the smoothness. These involve compensation between different structural elements on which the external force acts simultaneously and contribution of suboptimal structures, respectively. We estimate how many features a force-extension curve recorded in nonequilibrium, where the pulling proceeds faster than rearrangements in the secondary structure of the molecule, could show in principle. Our software is available to the public through an "RNA-pulling server."
Indium/Ammonium Chloride Mediated Selective Reduction of Aromatic Nitro Compounds: Practical Synthesis of 6-AminoChrysene

Abstract Reduction of aromatic and heteroaromatic nitro compounds to the corresponding amino compounds was achieved by indium/ammonium chloride induced reaction in aqueous ethanol. This method was extended for the preparation of large quantities of 6-aminochrysene in excellent yield.
An adaptive maximally decimated channelized UWB receiver with cyclic prefix

The frequency channelized receiver based on hybrid filter bank is a promising receiver structure for ultra-wideband (UWB) radio because of its relaxed circuit requirements and robustness to interference. The uncertainties in the analog analysis filters and the time varying nature of the propagation channels necessitate adaptive methods in practical frequency channelized receivers. Adaptive synthesis filters, however, suffer from slow convergence speed especially when maximally decimated to reduce the analog-digital converter sampling frequency. To improve the convergence speed, the cyclic prefix is applied to the transmitted data. The propagation channel and the channelizer can then be modeled as a circulant matrix and block CM, respectively. Such matrix representation enables the transmitted data to be recovered by two cascaded one-tap equalizers, one of which corresponds to the channelizer and the other to the propagation channel. The cascaded structure is attractive as it allows the estimation of the propagation channel and the channelizer, which vary at vastly different rates, to be updated separately. Adaptive algorithms for both the fractionally spaced equalizer and the symbol spaced equalizer are derived. After initial convergence during startup, the adaptive performance of the channelized receiver to different propagation channels is similar to that of an ideal full band receiver.
Using revealed and stated preference data to estimate the scope and access benefits associated with cave diving

In a single-site travel cost model framework, revealed and stated preference data are jointly estimated to provide the first use-value estimate associated with recreational cave diving. Focusing on one of Florida's first magnitude springs, we estimate average per-person per-trip use values of approximately $155, generating annual cave diving use values in the region of $1075. Further, in an investigation of potential site quality changes, we find that divers are sensitive to scope effects with an additional cave system increasing annual per-person use values by approximately $100, while improved access yields an additional $50 in per-person annual consumer surplus. Finally, three additional model specifications are estimated and indicate that divers use different travel cost preferences when assessing their revealed and stated preference trip counts but a single preference structure to evaluate site quality changes.
An Analysis of the Source and Nature of Technical Change: The Case of U.S. Agriculture

This paper proposes a methodology to investigate the process of technical change with a focus on the dynamic effects of R&D investments on productivity, and on the induced innovation hypothesis for both inputs and outputs. The approach builds on a nonparametric representation of the underlying technology. An application to U.S. agriculture is presented. By distinguishing between private and public R&D investments, the analysis provides useful insights into the source and the dynamic nature of technical progress.
Split-step complex Padé-Fourier depth migration

SUMMARY We present a split-step complex Pade-Fourier migration method based on the one-way wave equation. The downward-continuation operator is split into two downward-continuation operators: one operator is a phase-shift operator and the other operator is a finite-difference operator. A complex treatment of the propagation operator is applied to mitigate inaccuracies and instabilities due to evanescent waves. It produces high-quality images of complex structures with fewer numerical artefacts than those obtained using a real approximation of a square-root operator in the one-way wave equation. Tests on zero-offset data from the SEG/EAGE salt data show that the method improves the image quality at the cost of an additional 10 per cent computational time compared to the conventional Fourier finite-difference method.
Inflation, symmetry, and B-modes

Abstract We examine the role of using symmetry and effective field theory in inflationary model building. We describe the standard formulation of starting with an approximate shift symmetry for a scalar field, and then introducing corrections systematically in order to maintain control over the inflationary potential. We find that this leads to models in good agreement with recent data. On the other hand, there are attempts in the literature to deviate from this paradigm by envoking other symmetries and corrections. In particular: in a suite of recent papers, several authors have made the claim that standard Einstein gravity with a cosmological constant and a massless scalar carries conformal symmetry. They claim this conformal symmetry is hidden when the action is written in the Einstein frame, and so has not been fully appreciated in the literature. They further claim that such a theory carries another hidden symmetry; a global SO ( 1 , 1 ) symmetry. By deforming around the global SO ( 1 , 1 ) symmetry, they are able to produce a range of inflationary models with asymptotically flat potentials, whose flatness is claimed to be protected by these symmetries. These models tend to give rise to B-modes with small amplitude. Here we explain that standard Einstein gravity does not in fact possess conformal symmetry. Instead these authors are merely introducing a redundancy into the description, not an actual conformal symmetry. Furthermore, we explain that the only real (global) symmetry in these models is not at all hidden, but is completely manifest when expressed in the Einstein frame; it is in fact the shift symmetry of a scalar field. When analyzed systematically as an effective field theory, deformations do not generally produce asymptotically flat potentials and small B-modes as suggested in these recent papers. Instead, deforming around the shift symmetry systematically, tends to produce models of inflation with B-modes of appreciable amplitude. Such simple models typically also produce the observed red spectral index, Gaussian fluctuations, etc. In short: simple models of inflation, organized by expanding around a shift symmetry, are in excellent agreement with recent data.
Genetic Adverse Selection: Evidence from Long-Term Care Insurance and Huntington Disease

Abstract Individual, personalized genetic information is increasingly available, leading to the possibility of greater adverse selection over time, particularly in individual-payer insurance markets. We use data on individuals at risk for Huntington disease (HD), a degenerative neurological disorder with significant effects on morbidity, to estimate adverse selection in long-term care insurance. We find strong evidence of adverse selection: individuals who carry the HD genetic mutation are up to 5 times as likely as the general population to own long-term care insurance. This finding is supported both by comparing individuals at risk for HD to those in the general population and by comparing across tested individuals in the HD-risk population with and without the HD mutation.
GTPases and the origin of the ribosome.

Background This paper is an attempt to trace the evolution of the ribosome through the evolution of the universal P-loop GTPases that are involved with the ribosome in translation and with the attachment of the ribosome to the membrane. The GTPases involved in translation in Bacteria/Archaea are the elongation factors EFTu/EF1, the initiation factors IF2/aeIF5b + aeIF2, and the elongation factors EFG/EF2. All of these GTPases also contain the OB fold also found in the non GTPase IF1 involved in initiation. The GTPase involved in the signal recognition particle in most Bacteria and Archaea is SRP54.
The Effect of Void Area on Brick Masonry Performance

Higher void (hollow) brick offer the potential for energy savings, decreased raw material usage and reduced environmental impact. These advantages are related to the movement toward “green” building materials. The National Brick Research Center has performed an extensive study comparing the wall system performance of hollow and solid brick. Hollow masonry units are defined by ASTM C 652 while solid masonry units are specified in ASTM C 216. The key differences between these two specifications are related to the permissible void area and face shell thickness. The objective of this work was to determine what effect, if any, increasing void area might have on important aspects of the performance of brick masonry. The effect of decreasing face shell thickness was also evaluated. For this study, the performance of several sets of comparison extruded brick was measured. These sets of comparison brick represent a range of manufacturers and, thus, a range of physical properties. Water penetration, flexural bond strength, and compressive strength were measured on each type of brick and used as indicators of potential performance in a wall. Additionally, mortar usage as a function of void area was studied. Based on the results of testing from these sets of comparison brick, increasing void area or decreasing face shell thickness did not result in increased water penetration or decreased flexural bond strength.
A simple route to acylsilane enol esters from enol esters

Abstract A new methodology is described for the synthesis of enol esters of acylsilanes, from readily available vinyl esters. A solution of LDA is added to a mixture of an enol ester (preferably sterically congested, with only one α- carboxyl proton, eg 2-ethylhexanoate) and a chlorosilane at −78°C to afford the product.
Microwave-Mediated Nickel-Catalyzed Cyclotrimerization Reactions: Total Synthesis of Illudinine

Rapid and efficient [2 + 2 + 2] cyclotrimerization reactions were discovered through the application of microwave irradiation in conjunction with a Ni(CO)2(PPh3)2 catalyst. This enables the facile ...
International production, technology diffusion, and trade

The paper develops a general equilibrium model of international production and trade. Technology is carried across borders by multinational producers and the set of technologies being used in a particular country is endogenous. Production locations are chosen based on the costs of production and getting the product to market. A producer may manufacture its product in its home country, target market country, or a third country. Estimated model parameters describe the states of technology in different countries, barriers to international investment, and trade costs. It is found that the barriers to international trade and investment are highly correlated. The model is used to measure the extent of technology diffusion across countries, study the relationship between international production and trade, investigate the effects of free-trade agreements (FTAs) on offshoring, and to quantify the welfare effects of international production and trade.
Domain wall fermions and applications

Abstract Domain wall fermions provide a complimentary alternative to traditional lattice fermion approaches. By introducing an extra dimension, the amount of chiral symmetry present in the lattice theory can be controlled in a linear way. This results in improved chiral properties as well as robust topological zero modes. A brief introduction on the subject and a discussion of chiral properties and applications, such as zero and finite temperature QCD, N = 1 Super Yang-Mills, and four-fermion theories, is presented.
Effect of solution medium on the rate constants of excited-state electron-transfer quenching reactions of ruthenium(II)-diimine photosensitizers

Abstract In this paper, we review the effects of solution medium (pH, solvent, temperature, ionic strength, specific electrolytes) on the oxidative and reductive quenching rate constants k q of the excited states of Ru(II)-diimine photosensitizers. Diffusion of the donor and acceptor species together to form the precursor complex ( k et ) and electron transfer within the complex ( k et ) contribute to the value of k q . Values of k d vary with bulk solution properties; variations of k et can be described within the context of Marcus theory, wherein dynamic solvent effects influence the nuclear frequency factor and electronic coupling, and static properties cause changes in the driving force of electron transfer ΔG et o and the reorganization energy λ. The pH can affect the state of protonation of the excited photosensitizer and/or the quencher, thereby altering k et through changes in ΔG ct o and k d through changes in the charges of the reactants. Ionic species are ion-paired by the dominant counterion; the Olson-Simonson treatment allows the electron transfer components of quenching for ion-paired ( k ip ) and nonion-paired ( k mp ) species to be extracted. The quenching of ∗ Ru(bpy) 3 2+ by methylviologen is used to demonstrate specific salt effects, which result in variations in λ; λ is lowest, and k q highest, for the anions with the most weakly-held hydration spheres and the strongest structure-breaking abilities (e.g. ClO 4 − , I − ). Quenching rate constants can be fine-tuned through the variation of solvent, pH, electrolyte, ionic strength, and temperature.
A Variational Technique for Smoothing Flight-Test and Accident Data

The problem of determining aircraft motions along a trajectory is solved using a variational algorithm that generates unmeasured states and forcing functions, and estimates instrument bias and scale-factor errors. The problem is formulated as a nonlinear fixed-interval smoothing problem, and is solved as a sequence or linear two-point boundary value problems, using a sweep method. The algorithm has been implemented for use in flight-test and accident analysis. Aircraft motions are assumed to be governed by a six-degree-of-freedom kinematic model; forcing functions consist of body accelerations and winds, and the measurement model includes aerodynamic and radar data. Examples of the determination of aircraft motions from typical flight-test and accident data are presented.
Effects of Syngas Ash Particle Size on Deposition and Erosion of a Film Cooled Leading Edge

The paper investigates the deposition and erosion caused by Syngas ash particles in a film cooled leading edge region of a representative turbine vane. The carrier phase is predicted using large eddy simulation for three blowing ratios of 0.4, 0.8, and 1.2. Ash particle sizes of I μm, 3 μm, 5 μm, 7 μm, and 10 μm are investigated using La-grangian dynamics. The 1 μm particles with momentum Stokes number, St p =0.03 (based on approach velocity and leading edge diameter), follow the flow streamlines around the leading edge and few particles reach the blade surface. The 10 μm particles, on the other hand with a high momentum Stokes number, St p = 0. 03, directly impinge on the surface, with blowing ratio having a minimal effect. The 3 μm, 5 μm, and 7 μm particles with St p = 0.03, 0.8 and 1.4, respectively, show some receptivity to coolant flow and blowing ratio. On a number basis, 85―90% of the 10 μm particles, 70―65% of 7 μm particles, 40―50% of 5 μm particles, 15% of 3 μm particles, and less than 1% of I μm particles deposit on the surface. Overall there is a slight decrease in percentage of particles deposited with increase in blowing ratio. On the other hand, the potential for erosive wear is highest in the coolant hole and is mostly attributed to 5 μm and 7 μm particles. It is only at BR = 1.2 that 10 μm particles contribute to erosive wear in the coolant hole.
An Analysis of Gamma-Ray Burst Spectral Break Models

Typical � -ray burst (GRB) spectra are characterized by a spectral break Ep, which for bright BATSE bursts is found to be narrowly clustered around 300 keV. Recently identified X-ray flashes, which may account for a significant portion of the whole GRB population, seem to extend the Ep distribution to a broader range below 40 keV. Positive correlations among Ep and some other observed parameters have been noticed. On the other hand, within the cosmological fireball model, the issues concerning the dominant energy ingredient of the fireball as well as the location of the GRB emission site are still unsettled, leading to several variants of the fireball model. Here we analyze these models within a unified framework and critically reexamine the Ep predictions in the various model variants. Attention is focused on the predictions of the narrowness of the Ep distribution in different models and the correlations among Ep and other measurable observables. These model properties can be tested against the current and upcoming GRB data, through which the nature of the fireball as well as the mechanism and site of the GRB emission will be identified. In view of the current data, various models are appraised through a simple Monte Carlo simulation, and a tentative discussion about the possible nature of X-ray flashes is presented. Subject headings: gamma rays: bursts — radiation mechanisms: nonthermal — shock waves — stars: magnetic fields
The Added Complexity of Social Entrepreneurship: A Knowledge-Based Approach

Abstract Social entrepreneurship evades easy definition and conceptualization. In this paper, we attempt to advance social entrepreneurship theoretically by examining it conceptually, from a ‘theory of the firm’ perspective. If social entrepreneurship entails pursuit of a double bottom line (Dees, Harvard Business Review, 76 (1), 54–67, 1998), the added complexity of the social entrepreneurial venture identified by Tracey and Phillips (Academy of Management Learning & Education, 6, 264–71, 2007) should be discoverable from a ‘theory of the firm’ perspective. Applying the knowledge-based theory of the firm to social entrepreneurship, we aver that social entrepreneurship's added complexity is manifest when social entrepreneurial ventures make decisions about protecting their knowledge. Social entrepreneurial ventures manifest this added complexity in all three ways Tracey and Phillips identify: managing accountability, managing identity, and managing the double bottom line. In contrast to ordinary entrepren...
Cosmic Ray Origin, Acceleration and Propagation

This paper summarizes highlights of the OG3.1, 3.2 and 3.3 sessions of the XXVIth International Cosmic Ray Conference in Salt Lake City, which were devoted to issues of origin/composition, acceleration and propagation.
Superacidity of Boron Acids H2(B12X12) (X=Cl, Br)

Acid remarks: The anhydrous diprotic boron acids H(2)(B(12)X(12)) (X = Cl, Br; see picture, B orange, X green) are the first examples of diprotic superacids and may be the strongest acids yet isolated. Both protons protonate benzene to give benzenium ion salts that are stable at room temperature. These acids owe their existence to the stability of the icosahedral B(12) cluster with its dinegative charge buried beneath a layer of halide substituents.
Global Savings and Global Investment: The Transmission of Identified Fiscal Shocks

This paper examines the effect of exogenous shocks to savings on world capital markets. Exogenous tax increases in the United States (from Romer and Romer 2010) are only partially offset by changes in domestic private savings, and only a small amount is absorbed by increased domestic investment (contra Feldstein and Horioka 1980). Almost half the change in taxes is transmitted abroad through a change in the US current account. Other countries experience decreases in current accounts and increases in investment in response to exogenous US tax increases. We cannot reject symmetric responses across countries with different currency regimes and levels of development. (JEL E21, E22, E23, E62, F32, F42)
What is a Beverage Worth? Arbitrage Pricing and the Value of New Products: An Attribute-Space Approach

We empirically estimate the valuation of new carbonated soft drink products within a model of market value maximization. We show that equity value is an important consideration in the firm decision to differentiate or imitate in new product introductions. Our results indicate that differentiation is a marginally better strategy for new product introductions as opposed to imitation of existing products. This finding is quite logical given the already high levels of imitative competition existing in the carbonated soft drink category.
What Goes Up Must Come Down? Experimental Evidence on Intuitive Forecasting

Do laboratory subjects correctly perceive the dynamics of a mean-reverting time series? In our experiment, subjects re- ceive historical data and make forecasts at dif- ferent horizons. The time series process that we use features short-run momentum and long-run partial mean reversion. Half of the subjects see a version of this process in which the momentum and partial mean reversion un- fold over 10 periods ('fast'), while the other subjects see a version with dynamics that un- fold over 50 periods ('slow'). Typical subjects recognize most of the mean reversion of the fast process and none of the mean reversion of the slow process.
The maximum number of complete subgraphs in a graph with given maximum degree

Extremal problems involving the enumeration of graph substructures have a long history in graph theory. For example, the number of independent sets in a d-regular graph on n vertices is at most (2^d^+^1-1)^n^/^2^d by the Kahn-Zhao theorem [7,13]. Relaxing the regularity constraint to a minimum degree condition, Galvin [5] conjectured that, for n>=2d, the number of independent sets in a graph with @d(G)>=d is at most that in K"d","n"-"d. In this paper, we give a lower bound on the number of independent sets in a d-regular graph mirroring the upper bound in the Kahn-Zhao theorem. The main result of this paper is a proof of a strengthened form of Galvin@?s conjecture, covering the case n=<2d as well. We find it convenient to address this problem from the perspective of G@?. From this perspective, we show that the number of complete subgraphs of a graph G on n vertices with @D(G)=
A general SNP-based molecular barcode for Plasmodium falciparum identification and tracking

Background: Single nucleotide polymorphism (SNP) genotyping provides the means to develop a practical, rapid, inexpensive assay that will uniquely identify any Plasmodium falciparum parasite using a small amount of DNA. Such an assay could be used to distinguish recrudescence from re-infection in drug trials, to monitor the frequency and distribution of specific parasites in a patient population undergoing drug treatment or vaccine challenge, or for tracking samples and determining purity of isolates in the laboratory during culture adaptation and sub-cloning, as well as routine passage. Methods: A panel of twenty-four SNP markers has been identified that exhibit a high minor allele frequency (average MAF > 35%), for which robust TaqMan genotyping assays were constructed. All SNPs were identified through whole genome sequencing and MAF was estimated through Affymetrix array-based genotyping of a worldwide collection of parasites. These assays create a "molecular barcode" to uniquely identify a parasite genome. Results: Using 24 such markers no two parasites known to be of independent origin have yet been found to have the same allele signature. The TaqMan genotyping assays can be performed on a variety of samples including cultured parasites, frozen whole blood, or whole blood spotted onto filter paper with a success rate > 99%. Less than 5 ng of parasite DNA is needed to complete a panel of 24 markers. The ability of this SNP panel to detect and identify parasites was compared to the standard molecular methods, MSP-1 and MSP-2 typing. Conclusion: This work provides a facile field-deployable genotyping tool that can be used without special skills with standard lab equipment, and at reasonable cost that will unambiguously identify and track P. falciparum parasites both from patient samples and in the laboratory.
Optimal constrained graph exploration

We address the problem of constrained exploration of an unknown graph G = (V, E) from a given start node s with either a tethered robot or a robot with a fuel tank of limited capacity, the former being a tighter constraint. In both variations of the problem, the robot can only move along the edges of the graph, for example, it cannot jump between nonadjacent nodes. In the tethered robot case, if the tether (rope) has length l, then the robot must remain within distance l from the start node s. In the second variation, a fuel tank of limited capacity forces the robot to return to s after traversing C edges. The efficiency of algorithms for both variations of the problem is measured by the number of edges traversed during the exploration. We present an algorithm for a tethered robot that explores the graph in Θ(vEv) edge traversals. The problem of exploration using a robot with a limited fuel tank capacity can be solved with a simple reduction from the tethered robot case and also yields a Θ(vEv) algorithm. This improves on the previous best-known bound of O(vEv p vVvlog2vVv). Since the lower bound for the graph exploration problems is o(vEv), our algorithm is optimal within a constant factor.
Statistics of cosmological inhomogeneities

This contribution to the Proceedings is based on the talk given at the Conference on Birth of the Universe and Fundamental Physics, Rome, May 18-21, 1994. Some selected topics of the subject are reviewed: Models of Primordial Fluctuations; Reconstruction of the Cosmological Density Probability Distribution Function (PDF) from Cumulants; PDFs from the Zel'dovich Approximation and from Summarizing Perturbation Series; Fitting by the Log-normal Distribution.
Dimerization of cycloproparenes by silver ion

Abstract Cycloproparenes react with silver ion in chloroform to yield dimers which can be aromatized by dichlorodicyanoquinone in benzene to give the corresponding acene.
Fully Integrated AC Coupled Interconnect Using Buried Bumps

Presented is the complete demonstration of an assembled system using AC coupled interconnect (ACCI) and buried solder bumps. In this system, noncontacting input/output (I/O) are created by using half-capacitor plates on both a chip and a substrate, while buried solder bumps are used to provide power/ground distribution and physical alignment of the coupling plates. ACCI using buried bumps is a technology that provides a manufacturable solution for noncontacting I/O signaling by integrating high-density, low inductance power/ground distribution with high-density, high-speed I/O. The demonstration system shows two channels operating simultaneously at 2.5 Gb/s/channel with a bit error rate less than 10-12, across 5.6 cm of transmission line on a multichip module (MCM). Simple transceiver circuits were designed and fabricated in a 0.35 -mum complementary metal-oxide-semiconductor (CMOS) technology, and for PRBS-127 data at 2.5 Gb/s transmit and receive circuits consumed 10.3 mW and 15.0 mW, respectively. This work illustrates the increasing importance of chip and package co-design for high-performance systems.
The performance of the Cedar multistage switching network

While multistage switching networks for vector multiprocessors have been studied extensively, detailed evaluations of their performance are rare. Indeed, analytical models, simulations with pseudosynthetic loads, studies focused on average-value parameters, and measurements of networks disconnected from the machine, all provide limited information. In this paper, instead, we present an in-depth empirical analysis of a multistage switching network in a realistic setting: We use hardware probes to examine the performance of the omega network of the Cedar shared-memory machine executing real applications. The machine is configured with 16 vector processors. The analysis suggests that the performance of multistage switching networks is limited by traffic nonuniformities. We identify two major nonuniformities that degrade Cedar's performance and are likely to slow down other networks too. The first one is the contention caused by the return messages in a vector access as they converge from the memories to one processor port. This traffic convergence penalizes vector reads and, more importantly, causes tree saturation. The second nonuniformity is the uneven contention delays induced by a relatively fair scheme to resolve message collisions. Based on our observations, we argue that intuitive optimizations for multistage switching networks may not be the most cost-effective ones. Instead, we suggest changes to increase the network bandwidth at the root of the traffic convergence tree and to delay traffic convergence up until the final stages of the network.
Traffic grooming in an optical WDM mesh network

In wavelength-division multiplexing (WDM) optical networks, the bandwidth request of a traffic stream can be much lower than the capacity of a lightpath. Efficiently grooming low-speed connections onto high-capacity lightpaths will improve the network throughput and reduce the network cost. In WDM/SONET ring networks, it has been shown in the optical network literature that by carefully grooming the low-speed connection and using wavelength-division multiplexer (OADM) to perform the optical bypass at intermediate nodes, electronic ADMs can be saved and network cost will be reduced. In this study, we investigate the traffic-grooming problem in a WDM-based optical mesh topology network. Our objective is to improve the network throughput. We study the node architecture for a WDM mesh network with traffic-grooming capability. A mathematical formulation of the traffic-grooming problem is presented in this study and several fast heuristics are also proposed and evaluated.
A theoretical investigation of the rectangular microstrip antenna element

A theoretical treatment of the rectangular microstrip radiating element has been performed. The element has been modeled as a line resonator with radiation taking place at the open-circuited ends. This has been verified by using a liquid crystal visual detector. With the simplified model, the input impedance and the far fields have been calculated for different resonant modes. The interaction between the radiating ends will effect the input impedance, and this has been considered by defining a mutual conductance. Also, a mutual conductance between microstrip elements has been expressed in far-field quantities and plotted as a function of spacing along the E - and H - planes. The directivity of an isolated element has been calculated as the directivity of one radiating end times the contribution due to the array factor.
Circumstellar Dust Disks in Taurus-Auriga: The Submillimeter Perspective

We present a sensitive, multiwavelength submillimeter continuum survey of 153 young stellar objects in the Taurus-Auriga star formation region. The submillimeter detection rate is 61% to a completeness limit of � 10 mJy (3 � )at850� m.Theinferredcircumstellardiskmassesarelognormallydistributedwithameanmassof � 5 ; 10 � 3 M� and a large dispersion (0.5 dex). Roughly one-third of the submillimeter sources have disk masses larger than the minimalnebulafromwhichthesolarsystemformed.Themediandisk-to-starmassratiois0.5%.Theempiricalbehavior of the submillimeter continuum is best described as F� / � 2:0� 0:5 between 350 � m and 1.3 mm, which we argue is duetothecombinedeffectsofthefractionofopticallythickemissionandaflatterfrequencybehavioroftheopacity compared to the interstellar medium. The latter effect could be due to a substantial population of large dust grains, which presumably would have grown through collisional agglomeration. In this sample, the only stellar property that is correlated with the outer disk is the presence of a companion. We find evidence for significant decreases in submillimeterfluxdensities,diskmasses,andsubmillimetercontinuumslopesalongthecanonicalinfraredspectral energy distribution evolution sequence for young stellar objects. The fraction of objects detected in the submillimeter isessentially identicalto the fractionwith excessnear-infrared emission,suggestingthatdustin the inner and outer disks is removed nearly simultaneously.
The versatile synchronous observer

A synchronous observer is an adjunct to a system model that monitors its state variables and raises a signal when some condition is satisfied. Synchronous observers provide an alternative to temporal logic as a means to specify safety properties but have the benefit that they are expressed in the same notation as the system model. Model checkers that do use temporal logic can nonetheless employ synchronous observers by checking for properties such as "never (signal raised)." The use of synchronous observers to specify properties is well-known; rather less well-known is that they can be used to specify assumptions and axioms, to constrain models, and to specify test cases. The idea underlying all these applications is that the basic model generates more behaviors than are desired, the synchronous observer recognizes those that are interesting, and the model checker is constrained to just the interesting cases. The value in this approach is that it is usually much easier to write recognizers than generators. The approach is best exploited in languages such as SAL that provide explicit first class operators for synchronous and asynchronous composition. The paper describes and illustrates these applications of synchronous observers.
Spectral K-way ratio-cut partitioning and clustering

Recent research on partitioning has focused on the ratio-cut cost metric, which maintains a balance between the cost of the edges cut and the sizes of the partitions without fixing the size of the partitions a priori. Iterative approaches and spectral approaches to two-way ratio-cut partitioning have yielded higher quality partitioning results. In this paper, we develop a spectral approach to multi-way ratio-cut partitioning that provides a generalization of the ratio-cut cost metric to L-way partitioning and a lower bound on this cost metric. Our approach involves finding the k smallest eigenvalue/eigenvector pairs of the Laplacian of the graph. The eigenvectors provide an embedding of the graph's n vertices into a k-dimensional subspace. We devise a time and space efficient clustering heuristic to coerce the points in the embedding into k partitions. Advancement over the current work is evidenced by the results of experiments on the standard benchmarks. >
Who Wants a Good Reputation

We examine a market in which long-lived firms face a short-term incentive to exert low effort, but could earn higher profits if it were possible to commit to high effort. There are two types of firms, "inept" firms who can only exert low effort, and "competent" firms who have a choice between high and low effort. There is occasional exit, and competent and inept potential entrants compete for the right to inherit the departing firm's reputation. Consumers receive noisy signals of effort choice, and so competent firms choose high effort in an attempt to distinguish themselves from inept firms. A competent firm is most likely to enter the market by purchasing an average reputation, in the hopes of building it into a good reputation, than either a very low reputation or a very high reputation. Inept firms, in contrast, find it more profitable to either buy high reputations and deplete them or buy low reputations.
Enumeration of One-Nodal Rational Curves in Projective Spaces

We give a formula computing the number of one-nodal rational curves that pass through an appropriate collection of constraints in a complex projective space. The formula involves intersections of tautological classes on moduli spaces of stable rational maps. We combine the methods and results from three different papers.
Multivalent, bifunctional dendrimers prepared by click chemistry

Unsymmetrical dendrimers, containing both mannose binding units and coumarin fluorescent units, have been prepared using click chemistry and shown to be highly efficient, dual-purpose recognition/detection agents for the inhibition of hemagglutination.
Examining routing solutions

A visualization tool, Examine, is presented to aid router development. Examine has the ability to display routing operations in a variety of ways (e.g., selective display of layers and nets). In addition, Examine has rudimentary animation facilities that enable a router developer to view a sequence of routing frames or a routing frame composite. >
A Convenient Synthesis of (R)-(+)-Perillaldehyde

Abstract A short and efficient synthesis of the commercially unavailable (R)-(+) isomer of perillaldehyde from (+)-limonene oxide has been developed.
Cosmic-Ray Scattering and Streaming in Compressible Magnetohydrodynamic Turbulence

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for revisions in the picture of cosmic-ray transport. In this paper we use recently obtained scaling laws for MHD modes to obtain the scattering frequency for cosmic rays. Using quasi-linear theory, we calculate gyroresonance with MHD modes (Alfvenic, slow, and fast) and transit-time damping (TTD) by fast modes. We provide calculations of cosmic-ray scattering for various phases of interstellar medium with realistic interstellar turbulence driving that is consistent with the velocity dispersions observed in diffuse gas. We account for the turbulence cutoff arising from both collisional and collisionless damping. We obtain analytical expressions for diffusion coefficients that enter the Fokker-Planck equation describing cosmic-ray evolution. We obtain the scattering rate and show that fast modes provide the dominant contribution to cosmic-ray scattering for the typical interstellar conditions in spite of the fact that fast modes are subjected to damping. We determine how the efficiency of the scattering depends on the characteristics of ionized media, e.g., plasma β. We calculate the range of energies for which the streaming instability is suppressed by the ambient MHD turbulence.
Tight bounds for prefetching and buffer management algorithms for parallel I/O systems

The I/O performance of applications in multiple-disk systems can be improved by overlapping disk accesses. This requires the use of appropriate prefetching and buffer management algorithms that ensure the most useful blocks are accessed and retained in the buffer. In this paper, we answer several fundamental questions on prefetching and buffer management for distributed-buffer parallel I/O systems. First, we derive and prove the optimality of an algorithm, P-min, that minimizes the number of parallel I/Os. Second, we analyze P-con, an algorithm that always matches its replacement decisions with those of the well-known demand-paged MIN algorithm. We show that P-con can become fully sequential in the worst case. Third, we investigate the behavior of on-line algorithms for multiple-disk prefetching and buffer management. We define and analyze P-Iru, a parallel version of the traditional LRU buffer management algorithm. Unexpectedly, we find that the competitive ratio of P-Iru is independent of the number of disks. Finally, we present the practical performance of these algorithms on randomly generated reference strings. These results confirm the conclusions derived from the analysis on worst case inputs.
Scoliosis in patients with Charcot-Marie-Tooth disease.

Background: Scoliosis appears to occur in approximately one-third of patients with Charcot-Marie-Tooth disease. Little is known about the response of these curves to treatment. The purpose of this study was to establish the prevalence of scoliosis in a large population of children and adolescents with Charcot-Marie-Tooth disease, to evaluate factors linked with curve progression, and to assess the response to orthotic and surgical treatment. Methods: The medical records of 298 patients were retrospectively reviewed. Radiographs were reviewed for patients identified as having spinal deformity. The type, size, and progression of the scoliotic curve were measured, and the effectiveness of bracing and surgical treatment was assessed. Results: Forty-five patients with scoliosis associated with Charcot-Marie-Tooth disease were identified. The average age at the diagnosis of the spinal deformity was 12.9 years, and the average curve magnitude at the time of diagnosis was 27.6°. One-third of the curves were left thoracic, and 49% were associated with increased thoracic kyphosis. Twenty-four of the thirty-four curves that were followed for more than one year progressed. Brace treatment was successful in only three of sixteen patients. Surgery was performed in fourteen of the forty-five patients. Long posterior spinal fusions were performed most often, with an average of 13.1 spinal segments fused. Instrumentation was used in all posterior fusions. Intraoperative neurologic monitoring was possible for only three of the twelve patients for whom it was attempted during surgery, but there were no intraoperative neurologic complications. Conclusions: Scoliosis in patients with Charcot-Marie-Tooth disease differs from that in patients with idiopathic scoliosis. Thoracic hyperkyphosis is common, and bracing is usually unsuccessful. Surgical fusion does not appear to be associated with a high rate of complications, although it is often impossible to perform intraoperative neurologic monitoring. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.
Hadronic Parity Violation in Few-Nucleon Systems

The weak interaction between quarks induces a parity-violating component in the interactions between nucleons, which is typically suppressed by a factor of $${\approx 10^{-7}}$$ compared to the dominant parity-conserving part. Because of the short range of the weak interactions, it provides a unique probe of the strong dynamics that confine quarks into nucleons. An experimental program to map out this weak component of the nuclear force is underway at a number of facilities, including the Spallation Neutron Source at Oak Ridge National Laboratory. The corresponding observables are related to few-nucleon processes at very low energies, at which pionless effective field theory provides a reliable and model-independent theoretical approach to hadronic parity violation. Results in two- and three-nucleon systems, the role of parity-violating three-nucleon forces, and possible extensions to other few-nucleon systems are discussed.
The Diffusion of Development

This paper provides a framework relating the vertical transmission of characteristics across generations - such as the transmission of culture, language, norms and values - to differences in income per capita across countries. We propose a novel way to measure cultural barriers using genetic distance, i.e. coancestor coefficients from population genetics. Our econometric methodology addresses the problem of spatial correlation inherent in having pairwise income differences as our dependent variable. We find a significant effect of genetic distance on income differences, even when controlling for geographical distance, differences in latitude, and other cultural and geographic distance measures. These results hold not only for contemporary income differences, but also for income differences measured as of 1500 and 1700. We uncover similar patterns of coefficients for the proximate determinants of income differences (differences in human capital, institutions, investment rates and population growth). Our results suggest an important role for vertically transmitted characteristics in the diffusion of development.
Use of volume-rendered images in registration of nuclear medicine studies

A simple operator-guided alignment technique based on volume-rendered images was developed to register tomographic nuclear medicine studies, For each of 2 three-dimensional data sets to be registered, volume-rendered images were generated in 3 orthogonal projections (x,y,z) using the method of maximum-activity projection. Registration was achieved as follows: a) One of the rendering orientations (e.g. x) was chosen for manipulation; b) The two-dimensional rendering was translated and rotated under operator control to achieve the best alignment as determined by visual assessment; c) This rotation and translation was then applied to the underlying three-dimensional data set, with updating of the rendered images in each of the orthogonal projections; d) Another orientation was chosen, and the process repeated. Since manipulation was performed on the small two-dimensional rendered image, feedback was instantaneous. To aid in the visual alignment, difference images and flicker images (toggling between the two data sets) were displayed. Accuracy was assessed by analysis of separate clinical data sets acquired without patient movement. After arbitrary rotation and translation of one of the two data sets, the 2 data sets were registered. Mean registration error was 0.36 pixels, corresponding to a 2.44 mm registration error. Thus, accurate registration can be achieved in under 10 minutes using this simple technique. >