cssi/SciSciGPT-SciSciNet huggingface dataset:
ZRT1 Harbors an Excess of Nonsynonymous Polymorphism and Shows Evidence of Balancing Selection in Saccharomyces cerevisiae.

Estimates of the fraction of nucleotide substitutions driven by positive selection vary widely across different species. Accounting for different estimates of positive selection has been difficult, in part because selection on polymorphism within a species is known to obscure a signal of positive selection among species. While methods have been developed to control for the confounding effects of negative selection against deleterious polymorphism, the impact of balancing selection on estimates of positive selection has not been assessed. In Saccharomyces cerevisiae, there is no signal of positive selection within protein coding sequences as the ratio of nonsynonymous to synonymous polymorphism is higher than that of divergence. To investigate the impact of balancing selection on estimates of positive selection, we examined five genes with high rates of nonsynonymous polymorphism in S. cerevisiae relative to divergence from S. paradoxus. One of the genes, the high-affinity zinc transporter ZRT1 showed an elevated rate of synonymous polymorphism indicative of balancing selection. The high rate of synonymous polymorphism coincided with nonsynonymous divergence among three haplotype groups, among which we found no detectable differences in ZRT1 function. Our results implicate balancing selection in one of five genes exhibiting a large excess of nonsynonymous polymorphism in yeast. We conclude that balancing selection is a potentially important factor in estimating the frequency of positive selection across the yeast genome.
A unique current-controlled negative resistance generator

THE PHENOMENON of negative resistance is so well known that it requires only a cursory review. Negative resistance elements or networks are distinguished by driving-point resistance characteristics which exhibit, at least over a limited portion of the current-voltage (i-v) plane, a falling voltage with increasing current. In general, devices which exhibit a negative resistance region over some portion of their i-v characteristic curve may be separated into two classes. The first class includes all elements with an inherent negative resistance region, such as the point-contact transistor, unijunction transistor, p-n-p-n transistor, tetrode vacuum tube, and tunnel diode. The second class includes all the networks in which one or more active elements are used in conjunction with passive elements arranged to maintain a predetermined function of current and voltage. This group includes all the devices which may be synthesized by utilizing positive feedback and such circuits as the complementary transistor cascade and the negative impedance converter. It should be understood that a physically realizable negative resistance is not the opposite of a positive resistance. For a positive resistance, the i-v relationship is an interdependent one, but for a negative resistance, the element utilizes an internal phenomenon which depends only on the potential or only on the current. Therefore, a 2-terminal negative resistance device comprises an internal energy source which is controlled either by the current through or the potential across its terminals, but not by both.
Performance evaluation of CPU isolation mechanisms in a multimedia OS kernel

To allow continuous media applications fine-grained control over their CPU allocations, and to protect these allocations from each other, thread priorities must have quality-of- service (QoS) interpretation. To this end, we present a CPU scheduler based on the well-defined resource specification of service curve. Service curve is distinguished from the traditional notion of rate by its ability to flexibly decouple delay and rate performance. Apart from how we compute thread priorities, predictable performance is hard to achieve also because threads can interact with each other and contend for synchronization resources. Such interactions can contribute to various forms of priority inversion. We discuss a new approach of dynamic priority inheritance in our CPU scheduler that solves priority inversion due to lock contention. To solve priority inversion arising from incompatible client/server resource specifications, we employ a train abstraction that allows a thread of control to visit multiple protection domains while carrying its resource and scheduling state intact. Train has been applied to real applications like a Solaris X window server. Finally, we present a mechanism for Internet flow specifications to reserve CPU time for network receive interrupt processing. We demonstrate an experimental system in which the combined techniques provide effective CPU isolation under various conditions of lock contention, client/server programming, and network processing.
Assisting whole-farm decision-making through stochastic budgeting ∗

Abstract Stochastic budgeting is used to simulate the business and financial risk and the performance over a 6-year planning horizon on a Norwegian dairy farm. A major difficulty with stochastic whole-farm budgeting lies in identifying and measuring dependency relationships between stochastic variables. Some methods to account for these stochastic dependencies are illustrated. The financial feasibility of different investment and management strategies is evaluated. In contrast with earlier studies with stochastic farm budgeting, the option aspect is included in the analysis.
New York Bight fault

High-resolution, single-channel and multichannel seismic-reflection profiles in the New York Bight provide 7 crossings of a 50-km-long fault that trends north-northeast for 30 km from its southern end, then bends northeast, and may continue northward beneath Long Island. Displacement, which is consistently down to the west, decreases upsection and suggests a growth fault. Dip of the fault is near vertical. Its maximum offset of 109 m is the largest offset at the base of the Coastal Plain known for any Cretaceous and younger fault along the East Coast. Seismic stratigraphic controls constrain motion on the fault between Late Cretaceous (95 m.y. B.P.) and middle Oligocene (30 m.y. B.P.). The evidence for Quaternary activity is ambiguous. The fault parallels a magnetic low to the east, interpreted as a buried Mesozoic rift basin from seismic-reflection data, and a gravity low to the west, interpreted as a structure within Paleozoic rocks from well data. Whether these structures control the location of, or movement on, the fault is not clear.
The Education of Dyslexic Children from Childhood to Young Adulthood

The past two decades have witnessed an explosion in our understanding of dyslexia (or specific reading disability), the most common and most carefully studied of the learning disabilities. We first review the core concepts of dyslexia: its definition, prevalence, and developmental course. Next we examine the cognitive model of dyslexia, especially the phonological theory, and review empiric data suggesting genetic and neurobiological influences on the development of dyslexia. With the scientific underpinnings of dyslexia serving as a foundation, we turn our attention to evidence-based approaches to diagnosis and treatment, including interventions and accommodations. Teaching reading represents a major focus. We first review those reading interventions effective in early grades, and then review interventions for older students. To date the preponderance of intervention studies have focused on word-level reading; newer studies are beginning to examine reading interventions that have gone beyond word reading to affect reading fluency and reading comprehension. The article concludes with a discussion of the critical role of accommodations for dyslexic students and the recent neurobiological evidence supporting the need for such accommodations.
Multigraph Sampling of Online Social Networks

State-of-the-art techniques for probability sampling of users of online social networks (OSNs) are based on random walks on a single social relation (typically friendship). While powerful, these methods rely on the social graph being fully connected. Furthermore, the mixing time of the sampling process strongly depends on the characteristics of this graph. In this paper, we observe that there often exist other relations between OSN users, such as membership in the same group or participation in the same event. We propose to exploit the graphs these relations induce, by performing a random walk on their union multigraph. We design a computationally efficient way to perform multigraph sampling by randomly selecting the graph on which to walk at each iteration. We demonstrate the benefits of our approach through (i) simulation in synthetic graphs, and (ii) measurements of Last.fm- an Internet website for music with social networking features. More specifically, we show that multigraph sampling can obtain a representative sample and faster convergence, even when the individual graphs fail, i.e., are disconnected or highly clustered.
Titanocene-Catalyzed Asymmetric Ketone Hydrosilylation: The Effect of Catalyst Activation Protocol and Additives on the Reaction Rate and Enantioselectivity

The efficient asymmetric hydrosilylation of ketones with a chiral titanocene catalyst has been realized. In this procedure, (R,R)-ethylenebis(tetrahydroindenyl) titanium difluoride (1) was used as the precatalyst, and alcohol additives were employed. Aromatic and α,β-unsaturated ketones were reduced to the corresponding alcohols with a high level of enantioselectivity.
The Effect of Gas Physics on the Halo Mass Function

Cosmological tests based on cluster counts require accurate calibration of the space density of massive haloes, but most calibrations to date have ignored complex gas physics associated with halo baryons. We explore the sensitivity of the halo mass function to baryon physics using two pairs of gas-dynamic simulations that are likely to bracket the true behaviour. Each pair consists of a baseline model involving only gravity and shock heating, and a refined physics model aimed at reproducing the observed scaling of the hot, intracluster gas phase. One pair consists of billion-particle resimulations of the original 500 h−1 Mpc Millennium Simulation of Springel et al., run with the smoothed particle hydrodynamics (SPH) code gadget-2 and using a refined physics treatment approximated by pre-heating (PH) at high redshift. The other pair are high-resolution simulations from the adaptive-mesh refinement code art, for which the refined treatment includes cooling, star formation and supernova feedback (CSF). We find that, although the mass functions of the gravity-only (GO) treatments are consistent with the recent calibration of Tinker et al. (2008), both pairs of simulations with refined baryon physics show significant deviations. Relative to the GO case, the masses of ∼1014 h−1 M⊙ haloes in the PH and CSF treatments are shifted by the averages of −15 ± 1 and +16 ± 2 per cent, respectively. These mass shifts cause ∼30 per cent deviations in number density relative to the Tinker function, significantly larger than the 5 per cent statistical uncertainty of that calibration.
Analysis and Design of Repetitive Control Systems Using the Regeneration Spectrum

The absolute and relative stability of continuous-time SISO repetitive control systems is examined here using a function of frequency termed the regeneration spectrum. The regeneration spectrum is easily computed and is related to important of the characteristic root distribution of such systems, for large values of the time delay. The regeneration spectrum is combined with other frequency domain measures of control system performance such as the sensitivity and complementary sensitivity functions to obtain improved insight into the trade-offs in repetitive control system design. The result is a more rational approach to repetitive control system design and is illustrated by an example.
An Improved Procedure for the Conversion of Alkenes and Glycals to 1,2-Diazides Using Mn(OAc)3·2H2O in Acetonitrile Containing Trifluoroacetic Acid

Abstract Alkenes and Glycals react with Mn(OAc3)·2H2O and NaN3 in 9:1 acetonitrile-trifluoroacetic acid to give 1,2-diazides in >80% yield. Allylic azides are formed by slow addition of NaN3 to a mixture of alkene, Mn(OAc)3·2H2O and Cu(OAc)2.
Nanosecond MOSFET gun pulser for the CESR high intensity linac injector

A fast solid-state pulser (PFH) for the Cornell CESR linac injector system is described. Stripline-packaged high-voltage power MOSFET devices are arranged in a novel cascade output topology to achieve extremely low transition times. In the present CESR injector, the PFH driver outputs pulses of 3 nanoseconds FNHM and 20 amperes peak current through an Eimac Y-796 cathode-grid assembly. Recovery time is approximately 10 nsec. Advantages of the MOSFET pulser over its hard-tube predecessor include a substantial increase in peak beam current, an order-of-magnitude reduction of gun interpulse recovery time and precise control of the unequal output pulse amplitudes required for e/sup +/ vs e/sup /njection modes. Reduction of physical size permits collocating the pulser with the linac electron gun assembly to minimize transmission line artifacts arising from unavoidable impedance mismatch over the gun's bias range. Successful implementation of the MOSFET linac gun pulser is an initial step to a future CESR B-factory injector. >
Advances in borehole seismic fracture diagnostics

Recent redesign of the hardware, software and data-reduction techniques associated with a triaxial borehole seismic system (BSS) have made possible better estimates of hydraulic fracture geometry. The redesigned triaxial system now incorporates three geophones per axis and proves 30 times the downhole gain of the replaced system, resulting in improved signal-to-noise ratios. This stronger signal, with an increased digitization rate for each of the six simultaneously digitized channels from two borehole seismic tools, has made possible the acquisition and processing of data that previously were inaccessible. The new electronics makes use of a null system and an improved calibration system that includes a synthetic event generator to produce sinusoidal signals of specified amplitude, frequency, and phase. These make readjustments to maintain system balance while the tool is in place downhole. A maximum likelihood event location scheme, incorporating an algorithm based on the use of directional statistics, is used to compute the location of microseisms and error estimates for these locations. Based on the ability to locate perforation shots, a 25-ft (7.6-m) uncertainty in the location of individual microseisms is the estimated accuracy of the redesigned system. This resulted in a fairly high level of confidence in the determination of themore » azimuth of the Nov. 1, 1986, hydraulic fracture in the fluvial zone at DOE's Multiwell Experiment (MWX) site.« less
Sedation and analgesia in the pediatric intensive care unit following laryngotracheal reconstruction

Summary Background: Children undergoing laryngotracheal reconstruction (LTR) may remain electively intubated in the pediatric intensive care unit (PICU) for several days following surgery to facilitate wound healing. These patients require sedation and analgesia with or without neuromuscular blockade inorder to prevent excessive head and neck movement with resultant tension on the tracheal anastomosis. Achieving this level of immobility features in caring for these children. Aim: The aims of this article are to describe a variety of commonly used sedation and analgesic agents and to provide guidance as to their optimal use following LTR.
Reflected Diffusions Defined via the Extended Skorokhod Map

This work introduces the extended Skorokhod problem (ESP) and associated extended Skorokhod map (ESM) that enable a pathwise construction of reflected diffusions that are not necessarily semimartingales. Roughly speaking, given the closure $G$ of an open connected set in ${\mathbb R}^J$, a non-empty convex cone $d(x) \subset {\mathbb R}^J$ specified at each point $x$ on the boundary $\partial G$, and a cadlag trajectory $\psi$ taking values in ${\mathbb R}^J$, the ESM $\bar \Gamma$ defines a constrained version $\phi$ of $\psi$ that takes values in $G$ and is such that the increments of $\phi - \psi$ on any interval $[s,t]$ lie in the closed convex hull of the directions $d(\phi(u)), u \in (s,t]$. When the graph of $d(\cdot)$ is closed, the following three properties are established: (i) given $\psi$, if $(\phi,\eta)$ solve the ESP then $(\phi,\eta)$ solve the corresponding Skorokhod problem (SP) if and only if $\eta$ is of bounded variation; (ii) given $\psi$, any solution $(\phi,\eta)$ to the ESP is a solution to the SP on the interval $[0,\tau_0)$, but not in general on $[0,\tau_0]$, where $\tau_0$ is the first time that $\phi$ hits the set ${\cal V}$ of points $x \in \partial G$ such that $d(x)$ contains a line; (iii) the graph of the ESM $\bar \Gamma$ is closed on the space of cadlag trajectories (with respect to both the uniform and the $J_1$-Skorokhod topologies). The paper then focuses on a class of multi-dimensional ESPs on polyhedral domains with a non-empty ${\cal V}$-set. Uniqueness and existence of solutions for this class of ESPs is established and existence and pathwise uniqueness of strong solutions to the associated stochastic differential equations with reflection is derived. The associated reflected diffusions are also shown to satisfy the corresponding submartingale problem. Lastly, it is proved that these reflected diffusions are semimartingales on $[0,\tau_0]$. One motivation for the study of this class of reflected diffusions is that they arise as approximations of queueing networks in heavy traffic that use the so-called generalised processor sharing discipline.
Sociological theories of human emotions

Over the past three decades, five general theoretical approaches to understanding the dynamics of human emotions have emerged in sociology: dramaturgical theories, symbolic interactionist theories, interaction ritual theories, power and status theories, and exchange theories. We review each of these approaches. Despite the progress made by these theories, several issues remain unresolved: the nature of emotions, feeling, and affect; the degree to which emotions are biologically based or socially constructed; the gap between social psychological theories on emotions and macrostructural theorizing; and the relatively narrow range of emotions theorized, coupled with an equally narrow focus on the structural and cultural conditions producing these emotions.
Forest Density Estimation

We study graph estimation and density estimation in high dimensions, using a family of density estimators based on forest structured undirected graphical models. For density estimation, we do not assume the true distribution corresponds to a forest; rather, we form kernel density estimates of the bivariate and univariate marginals, and apply Kruskal's algorithm to estimate the optimal forest on held out data. We prove an oracle inequality on the excess risk of the resulting estimator relative to the risk of the best forest. For graph estimation, we consider the problem of estimating forests with restricted tree sizes. We prove that finding a maximum weight spanning forest with restricted tree size is NP-hard, and develop an approximation algorithm for this problem. Viewing the tree size as a complexity parameter, we then select a forest using data splitting, and prove bounds on excess risk and structure selection consistency of the procedure. Experiments with simulated data and microarray data indicate that the methods are a practical alternative to Gaussian graphical models.
The Sensitivity of Economic Statistics to Coding Errors in Personal Identifiers

In this article we describe the sensitivity of small-cell flow statistics to coding errors in the identity of the underlying entities. Specifically, we present results based on a comparison of the U.S. Census Bureau's Quarterly Workforce Indicators before and after correcting for such errors in Social Security Number-based identifiers in the underlying individual wage records. The correction used involves a novel application of existing statistical matching techniques. It is found that even a very conservative correction procedure has a sizable impact on the statistics. The average bias ranges from .25% up to 15% for flow statistics, and up to 5% for payroll aggregates.
Application of Model Order Reduction to Compressor Aeroelastic Models

A model order reduction technique that yields low-order models of blade row unsteady aerodynamics is introduced. The technique is applied to linearized unsteady Euler CFD solutions in such a way that the resulting blade row models can be linked to their surroundings through their boundary conditions. The technique is applied to a transonic compressor aeroelastic analysis, in which the high-fidelity CFD forced-response results are better captured than with models that use single-frequency influence coefficients. A low-speed compressor stage is also modeled to demonstrate the multistage capability of the method. These examples demonstrate how model order reduction can be used to systematically improve the versatility, fidelity, and range of applicability of the low-order aerodynamic models typically used for incorporation of CFD results into aeroelastic analyses.
Highly selective synthesis of vitamin A and its derivatives. Critical comparison of some known palladium-catalyzed alkenyl-alkenyl coupling reactions

Abstract Vitamin A has been synthesized cleanly and selectively with essentially complete control of stereo- and regiochemistry in four linear and six overall steps from β-ionone and ( E )-3-methyl-2-penten-4-yn-1-ol via Pd-catalyzed cross coupling of an alkenylzinc with an alkenyl iodide; the use of other metals, such as Al, Zr, Mg, B, Cu, and Sn, being inferior to that of Zn.
MEMS resonators that are robust to process-induced feature width variations

A stability analysis and design method for MEMS resonators is presented. The frequency characteristics of a laterally vibrating resonator are analyzed. With the fabrication error on the sidewall of the structure being considered, the first and second order frequency sensitivities to the fabrication error are derived. A simple relationship between the proof mass area and perimeter, and the beam width, is developed for single material structures, which expresses that the proof mass perimeter times the beam width should equal six times the area of the proof mass. Design examples are given for the single material and multi-layer structures. The results and principles presented in the paper can be used to analyze and design other MEMS resonators.
Efficient Inference in Fully Connected CRFs with Gaussian Edge Potentials

Most state-of-the-art techniques for multi-class image segmentation and labeling use conditional random fields defined over pixels or image regions. While region-level models often feature dense pairwise connectivity, pixel-level models are considerably larger and have only permitted sparse graph structures. In this paper, we consider fully connected CRF models defined on the complete set of pixels in an image. The resulting graphs have billions of edges, making traditional inference algorithms impractical. Our main contribution is a highly efficient approximate inference algorithm for fully connected CRF models in which the pairwise edge potentials are defined by a linear combination of Gaussian kernels. Our experiments demonstrate that dense connectivity at the pixel level substantially improves segmentation and labeling accuracy.
Bayesian approach to cluster expansions

Cluster expansions have proven to be a valuable tool in alloy theory and other problems in materials science but the generation of cluster expansions can be a computationally expensive and time-consuming process. We present a Bayesian framework for developing cluster expansions that explicitly incorporates physical insight into the fitting procedure. We demonstrate how existing methods fit within this framework and use the framework to develop methods that significantly improve the predictive power of cluster expansions for a given training set size. The key to the methods is to apply physical insight and cross validation to develop physically meaningful prior probability distributions for the cluster expansion coefficients. We use the Bayesian approach to develop an efficient method for generating cluster expansions for low-symmetry systems such as surfaces and nanoparticles.
WASTE TREATMENT AT THE RADIOCHEMICAL ENGINEERING DEVELOPMENT CENTER

ABSTRACT At the Radiochemical Engineering Development Center (REDC), irradiated targets are processed for the recovery of valuable radioisotopes, principally transuranium nuclides. A system was recently installed for treating the various liquid alkaline waste streams for removal of excess radioactive contaminants at REDC. Radionuclides that are removed will be stored as solids, and thus the future discharge of radionuclides to liquid-low level waste tank storage will be greatly reduced. The treatment system is of modular design and is installed in a hot cell at REDC, where preliminary testing is in progress. The module incorporates the following: (1) a resorcinol-formaldehyde resin column for cesium removal, (2) a cross-flow filtration unit for removal of rare earths and actinides as hydroxide, and (3) a waste solidification unit. Process flowsheets for operation of the module, key features of the module design, and its computer-assisted control system are presented. Good operability of the cross-flow fil...
The joint development of hemispheric lateralization for words and faces

Consistent with long-standing findings from behavioral studies, neuroimaging investigations have identified a region of the inferior temporal cortex that, in adults, shows greater face selectivity in the right than left hemisphere and, conversely, a region that shows greater word selectivity in the left than right hemisphere. What has not been determined is how this pattern of mature hemispheric specialization emerges over the course of development. The present study examines the hemispheric superiority for faces and words in children, young adolescents and adults in a discrimination task in which stimuli are presented briefly in either hemifield. Whereas adults showed the expected left and right visual field superiority for face and word discrimination, respectively, the young adolescents demonstrated only the right-field superiority for words and no field superiority for faces. Although the children’s overall accuracy was lower than that of the older groups, like the young adolescents, they exhibited a right visual field superiority for words but no field superiority for faces. Interestingly, the emergence of face lateralization was correlated with reading competence, measured on an independent standardized test, after regressing out age, quantitative reasoning scores, and face discrimination accuracy. Taken together, these findings suggest that the hemispheric organization of face and word recognition do not develop independently and that word lateralization, which emerges earlier, may drive later face lateralization. A theoretical account in which competition for visual representations unfolds over the course of development is proposed to account for the findings.
A product study of the gas-phase reaction of Isoprene with the OH radical in the presence of NOx

The gas-phase reaction of isoprene with the OH radical, in the resence of NOx, was investigated at 298 ± 2 K and atmospheric pressure of air by long path length FT-IR spectroscopy. The primary products identified and their formation yields were: methacrolein, 0.21 ± 0.05; methyl vinyl ketone, 0.29 ± 0.07; and HCHO, with the observed yield being consistent with the sum of the methacrolein and methyl vinyl ketone yields. Combined with the previously reported yield of 0.044 ± 0.006 for 3-methylfuran, these products accounted for 55 ± 9% of the isoprene which reacted. Under conditions where the dark reaction of isoprene with NO2is not significant, the balance of the isoprene consumed could possibly be accounted for by the “organic nitrates” and “other carbonyl compounds” formed in estimated overall yields of ca. 12% and ca. 25%, respectively.
Selecting the "best" using data envelopment analysis

One of the most important strengths of data envelopment analysis, (DEA), is that it allows almost complete freedom in the way that each decision making unit, (DMU), evaluates itself relative to its peers. This tends to result in many DMUs receiving a high efficiency score. Particularly when DEA is applied in a decision making context, it may be desirable to select a single option rather than determining the set of efficient alternatives in ranking efficient DMU or to assist selecting a "best" DMU. Several extensions to DEA have been proposed and used. This paper examines, compares and integrates a variety of these methods. A less complicated application area is used to investigate the subtleties of DEA cross-efficiency.
Biradical and zwitterionic cyclizations of oxy-substituted enyne-allenes.

Oxyanion substitution of enyne-allenes causes both Myers−Saito and Schmittel cyclizations to switch their product formation preferences from diradicals to polar, closed-shell singlets. The oxyanion stabilization is larger for the Schmittel products than the Myers−Saito products because the latter must sacrifice aromaticity to maximize interaction. The changing character of the different reaction paths is reflected in their activation energies.
Arc flash boundary calculations using computer software tools

Arc flash protection boundary calculations have become easier to perform with the availability of personal computer software. These programs incorporate arc flash protection boundary formulas for different voltage and current levels, calculate the bolted fault current at each bus, and use built in time-current coordination curves to determine the clearing time of protective devices in the system. Results of the arc flash protection boundary calculations can be presented in several different forms - as an annotation to the one-line diagram, as a table of arc flash protection boundary distances, and as printed placards to be attached to the appropriate equipment. Basic arc flash protection boundary principles are presented in this paper along with several helpful suggestions for performing arc flash protection boundary calculations.
Intensity estimation from shot-noise data

The estimation of the intensity function of a Poisson-driven shot-noise process is addressed using a regularization technique, where the data is modeled as a signal term plus a signal-dependent noise term. A new data-based method for selecting a pair of regularization parameters is presented and compared with the minimum unbiased risk method. The detail in the intensity function can be recovered by both methods, but the new method does a better job at suppressing spurious oscillations. >
Symmetry Protected Topological phases of Quantum Matter

We describe recent progress in our understanding of the interplay between interactions, symmetry, and topology in states of quantum matter. We focus on a minimal generalization of the celebrated topological band insulators to interacting many particle systems, known as Symmetry Protected Topological (SPT) phases. In common with the topological band insulators these states have a bulk gap and no exotic excitations but have non-trivial surface states that are protected by symmetry. We describe the various possible such phases and their properties in three dimensional systems with realistic symmetries. We develop many key ideas of the theory of these states using simple examples. The emphasis is on physical rather than mathematical properties. We survey insights obtained from the study of SPT phases for a number of other theoretical problems.
Group secret handshakes or affiliation-hiding authenticated group key agreement

Privacy concerns in many aspects of electronic communication trigger the need to re-examine – with privacy in mind – familiar security services, such as authentication and key agreement. An Affiliation-Hiding Group Key Agreement (AH-AGKA) protocol (also known as Group Secret Handshake) allows a set of participants, each with a certificate issued by the same authority, to establish a common authenticated secret key. In contrast to standard AGKA protocols, an AH-AGKA protocol has the following privacy feature: If Alice, who is a member of a group G, participates in an AH-AGKA protocol, none of the other protocol participants learn whether Alice is a member of G, unless these participants are themselves members of group G. Such protocols are useful in suspicious settings where a set of members of a (perhaps secret) group need to authenticate each other and agree on a common secret key, without revealing their affiliations to outsiders. In this paper we strengthen the prior definition of AH-AGKA so that the security and privacy properties are maintained under any composition of protocol instances. We also construct two novel AH-AGKA protocols secure in this new and stronger model under the RSA and Gap Diffie-Hellman assumptions, respectively. Each protocol involves only two communication rounds and few exponentiations per player (e.g., no bilinear map operations). Interestingly, these costs are essentially the same as those of the underlying (unauthenticated) group key agreement protocol. Finally, our protocols, unlike prior results, retain their security and privacy properties without the use of one-time certificates.
Automatic caption localization in compressed video

We present a method to automatically localize captions in JPEG compressed images and the I-frames of MPEG compressed videos. Caption text regions are segmented from background images using their distinguishing texture characteristics. Unlike previously published methods which fully decompress the video sequence before extracting the text regions, this method locates candidate caption text regions directly in the DCT compressed domain using the intensity variation information encoded in the DCT domain. Therefore, only a very small amount of decoding is required. The proposed algorithm takes about 0.006 second to process a 240/spl times/350 image and achieves a recall rate of 99.17 percent while falsely accepting about 1.87 percent nontext DCT blocks on a variety of MPEG compressed videos containing more than 2,300 I-frames.
Opposing Gradients of Ribbon Size and AMPA Receptor Expression Underlie Sensitivity Differences among Cochlear-Nerve/Hair-Cell Synapses

The auditory system transduces sound-evoked vibrations over a range of input sound pressure levels spanning six orders of magnitude. An important component of the system mediating this impressive dynamic range is established in the cochlear sensory epithelium, where functional subtypes of cochlear nerve fibers differ in threshold sensitivity, and spontaneous discharge rate (SR), by more than a factor of 1000 (Liberman, 1978), even though, regardless of type, each fiber contacts only a single hair cell via a single ribbon synapse. To study the mechanisms underlying this remarkable heterogeneity in threshold sensitivity among the 5–30 primary sensory fibers innervating a single inner hair cell, we quantified the sizes of presynaptic ribbons and postsynaptic AMPA receptor patches in >1200 synapses, using high-power confocal imaging of mouse cochleas immunostained for CtBP2 (C-terminal binding protein 2, a major ribbon protein) and GluR2/3 (glutamate receptors 2 and 3). We document complementary gradients, most striking in mid-cochlear regions, whereby synapses from the modiolar face and/or basal pole of the inner hair cell have larger ribbons and smaller receptor patches than synapses located in opposite regions of the cell. The AMPA receptor expression gradient likely contributes to the differences in cochlear nerve threshold and SR seen on the two sides of the hair cell in vivo (Liberman, 1982a); the differences in ribbon size may contribute to the heterogeneity of EPSC waveforms seen in vitro (Grant et al., 2010).
A new route to 6-substituted 2,3-diaminopyridines

Abstract 2,3-Diaminopyridine reacts with cyclohexanone to form dihydro-4-azabenzimidazole-2-spirocyclohexane. Reaction of this intermediate with a variety of nucleophiles (e.g., water, phenylmercaptan, ethanol, dimethylamine, and diethylmalonate) in the presence of MnO 2 results in addition to the 5-position. Subsequent acidic hydrogenation affords 6-substituted-2,3-diaminopyridines, key synthons for the synthesis of bicyclic heterocycles.
Position, rotation, and scale invariant recognition of images using higher-order spectra

A new approach to recognition of images using invariant features based on higher-order spectra is presented. Higher-order spectra are translation invariant because translation produces linear phase shifts which cancel. Scale and amplification invariance are satisfied by the phase of the integral of a higher-order spectrum along a radial line in higher-order frequency space because the contour of integration maps onto itself and both the real and imaginary parts are affected equally by the transformation. Rotation invariance is introduced by deriving invariants from the Radon transform of the image and using the cyclic-shift invariance property of the discrete Fourier transform magnitude. Results on synthetic and actual images show isolated, compact clusters in feature space and high classification accuracies. >
The Red Queen, Success Bias, and Organizational Inertia

Why do successful organizations often move in new directions and then fail? We propose that this pattern is especially likely among organizations that have survived a history of competition. Such experience adapts organizations to their environment, through so-called “Red Queen” evolution, but being well adapted for one context makes moving into new contexts more hazardous. Meanwhile, managers in such organizations infer from their histories of competitive success a biased assessment of their organization's ability to change. Consequently, although surviving competition makes organizational change especially hazardous, managers in surviving organizations are especially inclined to such initiatives. We develop these ideas in an empirically testable model, and find supportive evidence in estimates of the model using data from the history of the U.S. computer industry.
Explosive ray solutions of nonlinear wave-wave interacting systems

Sufficient conditions for the existence of ray solutions of nonlinear wave-wave interacting systems are established. It is shown that, along these solutions, the phases of the waves are time invariant and the wave-energy transfer is always unidirectional or irreversible. Also, under certain conditions, the ray solutions are explosive. The applications of the main results to specific forms of two-wave and three-wave nonlinear interacting systems are discussed.
An essay on real wage index numbers

Real wage index numbers have been used to measure movements in the standard of living of the typical worker. This paper describes some of these indicators for the United States and England. A new real wage index is proposed that resembles the sliding scale used to adjust wages in certain industries years ago. This new index is applied to U.S. manufacturing industry and it suggests a fall in real wages by about 40 percent since 1960. Workers’ distributional position in U.S. manufacturing has deteriorated considerably.
Catalytic enantioselective stereoablative alkylation of 3-halooxindoles: facile access to oxindoles with C3 all-carbon quaternary stereocenters.

From 2 to 1! Racemic tertiary halooxindoles proceed to enantioenriched oxindoles bearing all-carbon quaternary stereocenters as a result of a catalytic enantioselective stereoablative process (see scheme). The application of this procedure allows for the rapid asymmetric construction of biologically significant alkaloid core motifs.
Methanol steam reforming for hydrogen production.

Review article covering developments in methanol steam reforming in the context of PEM fuel cell power systems. Subjects covered include methanol background, use, and production, comparison to other fuels, power system considerations, militrary requirements, competing technologies, catalyst development, and reactor and system development and demonstration.
Robust Wireless Servo Control Using a Discrete-Time Uncertain Markovian Jump Linear Model

This brief proposes a robust control synthesis technique for wireless servo applications modeled as an uncertain discrete-time Markovian jump linear system. It is desired to find mean square stabilizing state feedback controllers with upper bounded quadratic cost when the transition probabilities of the Markov chain describing the network conditions, the state space dynamics, and the initial condition are unknown but belong to known convex polytopic sets. Under appropriate assumptions, these parametric uncertainties can be examined simultaneously, and controllers can be synthesized using linear matrix inequalities (LMIs). The LMIs utilize extended parameters to reduce conservativeness due to initial condition and plant uncertainty. The proposed method is used to design and demonstrate a robust wireless servo controller for an inverted pendulum system.
Transitional Flow over an Elliptic Cone at Mach 8

The k‐‡ transitional/turbulence model is used to study the transitional e ow over an elliptic cone of aspect ratio of 2:1 at Mach 8 and a range of Reynolds numbers. Although the cone guration has been the subject of detailed experimental and computational investigations, it has not been possible to determine with certainty the instability mechanisms responsible for transition. The present analysis suggests that none of the obvious mechanisms, i.e., second-mode or crosse ow, are responsible for the transition. Instead, a form of bypass transition resulting from large-amplitudedisturbancesappearsto reproducequitewell theexperimentally measured heat-transferdata and the onset and the extent of transition over a wide range of Reynolds numbers.
Theia: visual signatures for problem diagnosis in large hadoop clusters

Diagnosing performance problems in large distributed systems can be daunting as the copious volume of monitoring information available can obscure the root-cause of the problem. Automated diagnosis tools help narrow down the possible root-causes--however, these tools are not perfect thereby motivating the need for visualization tools that allow users to explore their data and gain insight on the root-cause. In this paper we describe Theia, a visualization tool that analyzes application-level logs in a Hadoop cluster, and generates visual signatures of each job's performance. These visual signatures provide compact representations of task durations, task status, and data consumption by jobs. We demonstrate the utility of Theia on real incidents experienced by users on a production Hadoop cluster.
In Situ Measurements of Stress-Potential Coupling in Lithiated Silicon

An analysis of the dependence of electric potential on the state of stress of a lithiated-silicon electrode is presented. Based on the Larche and Cahn chemical potential for a solid solution, a thermodynamic argument is made for the existence of the stresspotential coupling in lithiated silicon; based on the known properties of the material, the magnitude of the coupling is estimated to be 60 mV/GPa in thin-film geometry. An experimental investigation is carried out on silicon thin-film electrodes in which the stress is measured in situ during electrochemical lithiation and delithiation. By progressively varying the stress through incremental delithiation, the relation between stress change and electric-potential change is measured to be 100–120 mV/GPa, which is of the same order of magnitude as the prediction of the analysis. The importance of the coupling is discussed in interpreting the hysteresis observed in the potential vs state-of-charge plots and the role of stress in modifying the maximum charge capacity of a silicon electrode under stress.
An Sp1 transcription factor coordinates caspase-dependent and -independent apoptotic pathways

During animal development, the proper regulation of apoptosis requires the precise spatial and temporal execution of cell-death programs, which can include both caspase-dependent and caspase-independent pathways. Although the mechanisms of caspase-dependent and -independent cell killing have been examined extensively, how these pathways are coordinated within a single cell that is fated to die is unknown. Here we show that the Caenorhabditis elegans Sp1 transcription factor SPTF-3 specifies the programmed cell deaths of at least two cells-the sisters of the pharyngeal M4 motor neuron and the AQR sensory neuron-by transcriptionally activating both caspase-dependent and -independent apoptotic pathways. SPTF-3 directly drives the transcription of the gene egl-1, which encodes a BH3-only protein that promotes apoptosis through the activation of the CED-3 caspase. In addition, SPTF-3 directly drives the transcription of the AMP-activated protein kinase-related gene pig-1, which encodes a protein kinase and functions in apoptosis of the M4 sister and AQR sister independently of the pathway that activates CED-3 (refs 4, 5). Thus, a single transcription factor controls two distinct cell-killing programs that act in parallel to drive apoptosis. Our findings reveal a bivalent regulatory node for caspase-dependent and -independent pathways in the regulation of cell-type-specific apoptosis. We propose that such nodes might act as features of a general mechanism for regulating cell-type-specific apoptosis and could be therapeutic targets for diseases involving the dysregulation of apoptosis through multiple cell-killing mechanisms.
Multi-time scale zero-sum differential games with perfect state measurements

We obtain necessary and sufficient conditions for the existence of “approximate” saddle-point solutions in linear-quadratic zero-sum differential games when the state dynamics are defined on multiple (three) time scales. These different time scales are characterized in terms of two small positive parameters ∈1, and ∈2, and the terminology “approximate saddle-point solution” is used to refer to saddle-point policies that do not depend on ∈1 and ∈2, while providing cost levels withinO(∈1) of the full-order game. It is shown in the paper that, under perfect state measurements, the original game can be decomposed into three subgames-slow, fast and fastest, the composite saddle-point solution of which make up the approximate saddle-point solution of the original game. Specifically, for the minimizing player, it is necessary to use a composite policy that uses the solutions of all three subgames, whereas for the maximizing player, it is sufficient to use a slow policy. In the finite-horizon case this slow policy could be a feedback policy, whereas in the infinite-horizon case it has to be chosen as an open-loop policy that is generated from the solution and dynamics of the slow subgame. These results have direct applications in theH ∞-optimal control of three-time scale singularly perturbed linear systems under perfect state measurements.
Polynomial methods for the structured singular value with real parameters

We consider the structured singular value problem with real parametric uncertainty only. Using techniques from algebraic geometry, we propose two algorithms that in principle can yield the precise value of the structured singular value at a fixed frequency. Their ability to do so depends upon their ability to find all common roots to a system of polynomial equations. The first algorithm is applicable to problems with two real parameters each of multiplicity two. The second algorithm is applicable to problems with n distinct real parameters. These algorithms have proved useful in applications to aerospace control law analysis.