cssi/SciSciGPT-SciSciNet huggingface dataset:
The architecture of the protein domain universe

Understanding the design of the universe of protein structures may provide insights into protein evolution. We study the architecture of the protein domain universe, which has been found to poses peculiar scale-free properties [Dokholyan, N.V., Shakhnovich, B., Shakhnovich, E.I., 2002b. Expanding protein universe and its origin from the biological Big Bang. Proceedings of the National Academy of Sciences of the United States of America 99, 14132–14136]. We examine the origin of these scale-free properties of the graph of protein domain structures (PDUG) and determine that that the PDUG is not modular, i.e. it does not consist of modules with uniform properties. Instead, we find the PDUG to be self-similar at all scales. We further characterize the PDUG architecture by studying the properties of the hub nodes that are responsible for the scale-free connectivity of the PDUG. We introduce a measure of the betweenness centrality of protein domains in the PDUG and find a power-law distribution of the betweenness centrality values. The scale-free distribution of hubs in the protein universe suggests that a set of specific statistical mechanics models, such as the self-organized criticality model, can potentially identify the principal driving forces of protein evolution. We also find a gatekeeper protein domain, removal of which partitions the largest cluster into two large sub-clusters. We suggest that the loss of such gatekeeper protein domains in the course of evolution is responsible for the creation of new fold families.
List decoding: algorithms and applications

Over the years coding theory and complexity theory have benefited from a number of mutually enriching connections. This article focuses on a new connection that has emerged between the two topics in the recent years. This connection is centered around the notion of “list-decoding” for error-correcting codes. In this survey we describe the list-decoding problem, the algorithms that have been developed, and a diverse collection of applications within complexity theory.
Tinkertoys for Gaiotto duality

We describe a procedure for classifying $ \mathcal{N} = 2 $ superconformal theories of the type introduced by Davide Gaiotto. Any curve, C, on which the 6D A N−1 SCFT is compactified, can be decomposed into 3-punctured spheres, connected by cylinders. We classify the spheres, and the cylinders that connect them. The classification is carried out explicitly, up through N = 5, and for several families of SCFTs for arbitrary N. These lead to a wealth of new S-dualities between Lagrangian and non-Lagrangian $ \mathcal{N} = 2 $ SCFTs.
2 P2P or not 2 P2P

In the hope of stimulating discussion, we present a heuristic decision tree that designers can use to judge how suitable a P2P solution might be for a particular problem. It is based on characteristics of a wide range of P2P systems from the literature, both proposed and deployed. These include budget, resource relevance, trust, rate of system change, and criticality.
Optical spectroscopy of a brown dwarf candidate

We have used the Low-Resolution Imaging Spectrograph on the Keck II telescope to observe the brown dwarf candidate D04. The spectrum matches that of a spectral type M7 dwarf, implying a photospheric temperature of ≈ 2600 K. This is consistent with the available (R-I)C and (I-K) colours. If the parallax measured by Hawkins et al. is correct, then the implication is that D04 has a radius of ∼ 0.035 Rodot;, or one-third that of Jupiter. This contradicts the predictions made by current stellar models that electron degeneracy leads to nearly constant radii for stars and brown dwarfs at masses below 0.1 Modot;. We suggest that an equally valid interpretation of the data is that D04 is a VB8 analogue at a distance of ≈ 150 pc.
Tax Reforms and Evidence of Transfer Pricing

The manipulation of transfer prices changes the relative tax burdens multinational firms face in their different countries of operation. Transfer price manipulation also triggers changes in the tar...
Redox-triggered chiroptical molecular switches

Efficient chiroptical molecular redox switches have been engineered that display multiple stable optically active forms, chemically reversible redox processes, and highly sensitive chiroptical responses. Systems that have been studied in this context include electro-active organic polymers, redox-active coordination complexes, and certain organic compounds that may be oxidized or reduced reversibly. Studies in this field have yielded diverse platforms that benefit from dynamic stereochemical and electronic phenomena. This tutorial review introduces basic design criteria for chiroptical molecular switches, summarizes examples, and provides an outlook for future work in the area.
Processing Data in Bits and Pieces

A data-handling unit is described which permits binary or decimal arithmetic to be performed on data fields of any length from one to sixty-four bits. Within the field, character structure can be further specified: these processing entities, called bytes, may be from one to eight bits long. Fields may be stored with or without algebraic sign. On all operations, the relative offset or shift between the operand from memory and that from the accumulator can be specified. Besides the arithmetic operations, three new logical instructions allow any of the sixteen logical connectives of two variables to operate upon each pair of bits in the memory and accumulator operands. The variable field length, variable byte-size features, extend the use of connective operations to a surprisingly wide variety of logical, house-keeping, and editing tasks. These arithmetic and connective instructions are general and powerful programming tools which greatly simplify complex manipulations. Programming of typical tasks, with both the new instructions and with the instruction set of a conventionally-organized computer, has shown that the new set requires substantially fewer instructions to be written, stored, and executed. Furthermore, the new instruction set has considerably fewer distinct operations than the more conventional set. This is possible because the general-purpose instructions of the new set replace many ad hoc instructions which deal with pieces of instructions or data words, or which perform shifting, packing, or editing functions. The initial application of the variable field length data-processing unit is in the IBM Stretch computer.
New physics signals in longitudinal gauge boson scattering at the LHC

We introduce a novel technique designed to look for signatures of new physics in vector boson fusion processes at the TeV scale. This functions by measuring the polarization of the vector bosons to determine the relative longitudinal to transverse production. In studying this ratio we can directly probe the high energy E 2-growth of longitudinal vector boson scattering amplitudes characteristic of models with non-Standard Model (SM) interactions. We will focus on studying models parameterized by an effective Lagrangian that include a light Higgs with non-SM couplings arising from TeV scale new physics associated with the electroweak symmetry breaking, although our technique can be used in more general scenarios. We will show that this technique is stable against the large uncertainties that can result from variations in the factorization scale, improving upon previous studies that measure cross section alone.
Joint spatial and frequency domain motion analysis

Traditionally, motion estimation and segmentation have been performed mostly in the spatial domain, i.e., using the luminance information in the video sequence. Frequency domain representation offers an alternative, rich source of motion information, which has been used to a very limited extent in the past, and on relatively simple problems such as image registration. We review our work during the last few years on an approach to video motion analysis that combines spatial and Fourier domain information. We review our methods for (1) basic (translation and rotation) motion estimation and segmentation, for multiple moving objects, with constant as well as time varying velocities; and (2) more complicated motions, such as periodic motion, and periodic motion superposed on translation. The joint space analysis leads to more compact and computationally efficient solutions than existing techniques.
Time-Frequency Analysis of Rocket Nozzle Wall Pressures during Start-up Transients

Surveys of the fluctuating wall pressure were conducted on a sub-scale, thrust- optimized parabolic nozzle in order to develop a physical intuition for its Fourier-azimuthal mode behavior during fixed and transient start-up conditions. These unsteady signatures are driven by shock wave turbulent boundary layer interactions which depend on the nozzle pressure ratio and nozzle geometry. The focus however, is on the degree of similarity between the spectral footprints of these modes obtained from transient start-ups as opposed to a sequence of fixed nozzle pressure ratio conditions. For the latter, statistically converged spectra are computed using conventional Fourier analyses techniques, whereas the former are investigated by way of time-frequency analysis. The findings suggest that at low nozzle pressure ratios -- where the flow resides in a Free Shock Separation state -- strong spectral similarities occur between fixed and transient conditions. Conversely, at higher nozzle pressure ratios -- where the flow resides in Restricted Shock Separation -- stark differences are observed between the fixed and transient conditions and depends greatly on the ramping rate of the transient period. And so, it appears that an understanding of the dynamics during transient start-up conditions cannot be furnished by a way of fixed flow analysis.
Carbon nanotube–nanocrystal heterostructures

The importance of generating carbon nanotube–nanoparticle heterostructures is that these composites ought to take advantage of and combine the unique physical and chemical properties of both carbon nanotubes and nanoparticles in one discrete structure. These materials have potential applicability in a range of diverse fields spanning heterogeneous catalysis to optoelectronic device development, of importance to chemists, physicists, materials scientists, and engineers. In this critical review, we present a host of diverse, complementary strategies for the reliable synthesis of carbon nanotube–nanoparticle heterostructures using both covalent as well as non-covalent protocols, incorporating not only single-walled and multi-walled carbon nanotubes but also diverse classes of metallic and semiconducting nanoparticles (221 references).
An Efficient Method for the Chemoselective Synthesis of Acylals from Aromatic Aldehydes Using Bismuth Triflate

Abstract Aromatic aldehydes are smoothly converted into the corresponding acylals in good yields in the presence of 0.10 mol% Bi(OTf)3·xH2O. Ketones are not affected under the reaction conditions. The highly catalytic nature of bismuth triflate and the fact that it is relatively non-toxic, easy to handle and insensitive to small amounts of air and moisture makes this procedure especially attractive for large-scale synthesis.
A new multigrid approach to convection problems

Abstract A new multigrid method for convection problems is presented. It is designed to overcome the problem of alignment, the flow being aligned with the grid. The technique employs semi-coarsening in several directions simultaneously and gives rise to multiple coarser grids with the same total number of points per grid-level, but with different sizes in each co-ordinate direction. The amount of work per multigrid cycle is still O(N). As an example, the method is applied to the nonlinear upwind-differenced Euler equations of gas dynamics in two dimensions. Convergence rates are estimated by two-level Fourier analysis for the linearised equations. Numerical experiments on the nonlinear equations confirm these estimates.
Are Volatility Estimators Robust with Respect to Modeling Assumptions

We consider microstructure as an arbitrary contamination of the underlying latent securities price, through a Markov kernel Q. Special cases include additive error, rounding and combinations thereof. Our main result is that, subject to smoothness conditions, the two scales realized volatility is robust to the form of contamination Q. To push the limits of our result, we show what happens for some models that involve rounding (which is not, of course, smooth) and see in this situation how the robustness deteriorates with decreasing smoothness. Our conclusion is that under reasonable smoothness, one does not need to consider too closely how the microstructure is formed, while if severe non-smoothness is suspected, one needs to pay attention to the precise structure and also the use to which the estimator of volatility will be put.
Does a Legal Ban on Sex-Selective Abortions Improve Child Sex Ratios? Evidence from a Policy Change in India

Abstract Despite strong recent economic growth, gender inequality remains a major concern for India. This paper examines the effectiveness of a public policy geared towards the reduction of gender inequality. The national Pre-Conception and Pre-Natal Diagnostics Techniques (PNDT) Act of 1994, implemented in 1996, banned sex-selective abortions in India. Although demographers frequently mention the futility of the Act, we are among the first to evaluate the law using a treatment-effect analysis framework. Using village and town level longitudinal data from the 1991 and 2001 censuses, we find a significantly positive impact of the PNDT Act on female-to-male child sex ratio. Given the almost ubiquitous decline in the observed child sex ratio during this period, we argue that the law was successful in preventing any further worsening of the gender imbalance. We find that a possible absence of the law would have led to at least 106,000 fewer female children.
The impact of memory models on software reliability in multiprocessors

The memory consistency model is a fundamental system property characterizing a multiprocessor. The relative merits of strict versus relaxed memory models have been widely debated in terms of their impact on performance, hardware complexity and programmability. This paper adds a new dimension to this discussion: the impact of memory models on software reliability. By allowing some instructions to reorder, weak memory models may expand the window between critical memory operations. This can increase the chance of an undesirable thread-interleaving, thus allowing an otherwise-unlikely concurrency bug to manifest. To explore this phenomenon, we define and study a probabilistic model of shared-memory parallel programs that takes into account such reordering. We use this model to formally derive bounds on the vulnerability to concurrency bugs of different memory models. Our results show that for 2 concurrent threads, weaker memory models do indeed have a higher likelihood of allowing bugs. On the other hand, we show that as the number of parallel, buggy threads increases, the gap between the different memory models becomes proportionally insignificant, and thus the importance of using a strict memory model diminishes.
Winning quick and dirty: the greedy random walk

As a strategy to complete games quickly, we investigate one-dimensional random walks where the step length increases deterministically upon each return to the origin. When the step length after the kth return equals k, the displacement of the walk x grows linearly in time. Asymptotically, the probability distribution of displacements is a purely exponentially decaying function of |x|/t. The probability E(t, L) for the walk to escape a bounded domain of size L at time t decays algebraically in the long-time limit, E(t, L) ~ L/t2. Consequently, the mean escape time t ~ Lln L, while tn ~ L2n−1 for n > 1. Corresponding results are derived when the step length after the kth return scales as kα for α > 0.
Model-set sequence conditioned estimation for variable-structure MM estimation

The most important, natural and practical approach to variable-structure multiple-model estimation is the recursive adaptive model-set (RAMS) approach. It consists of two functional components: model-set adaptation and model- set sequence conditioned estimation. This paper makes contribution to the second component. Specifically, a general, optimal single-step and highly efficient recursion for model-set sequence conditioned estimation based on an arbitrary time-varying model-set sequence is obtained by an extension of the well-known interacting multiple-model (IMM) algorithm. This recursion provides a natural and systematic algorithm, which is optimal within the RAMS approach, for assigning the probabilities to newly activated models and initializing the filters based on these models. In addition, an optimal and highly efficient fusion method is presented for obtaining the overall estimate from these based on two arbitrary model sets, not necessarily disjoint. The optimal recursion and fusion provide a solution to the problem of model-set sequence conditioned estimation that is fairly satisfactory for most practical situations. The results presented here have been employed in the recent development of two variable-structure MM estimators, the likely-mode set and the model-group switching algorithms, that are generally applicable, easily implementable, and significantly superior the best fixed-structure MM estimators available.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Dynamic Routing of Time-Sensitive Air Cargo using Real-Time Information

Abstract The route planning of time-sensitive air-cargo is becoming more important with the growing air-network congestion and delays. We consider a freight forwarder’s routing of a time-sensitive air-cargo in the presence of real-time and historical information regarding flight availability, departure delays and travel times. A departure delay estimation model is developed to account for real-time information inaccuracy. A novel Markov decision model is formulated and solved with online backward induction. Through synthetic experiments and case studies, we demonstrate that dynamic routing with real-time information can improve delivery reliability and reduce expected cost.
How Housing Booms Unwind: Income Effects, Wealth Effects, and Feedbacks through Financial Markets

This paper considers dynamics in the reversal of booms in the housing market. We analyze three related mechanisms which govern the propagation of changes in the housing market throughout the rest of an advanced economy: wealth effects, income effects, and effects through financial markets. As the decade-long boom in the US housing market unwinds, we anticipate that there will be small wealth effects transmitted to the economy, but there will be large income effects affecting the rest of the economy and substantial financial market effects. If the current decline in housing starts and residential investment echoes the declines of the last three housing downturns, we estimate that gross national product (GNP) growth will be reduced by close to 3 per cent. Beyond the decline in housing investment, the recent turmoil in financial markets makes a recession induced by housing market conditions increasingly likely.
Hybrid protein-polymer biomimetic membranes

Protein-functionalized polymers retain dramatically increased stability over lipid membranes and the unique ability to be deposited on solid substrates in the ABA complex. Furthermore, since these polymers can mimic hydrophilic/hydrophobic biological environments in a single molecular chain, direct adsorption of protein-functionalized biomembrane films is enabled, which is a significant advantage over conventional lipid systems. Following the demonstration of protein mutagenesis and nanoscale biomimetic membrane fabrication, monolayer arrays of pore proteins have been deposited onto silicon wafers for applications in sensing nanomolecules such as conjugated quantum dots and colloidal gold beads. Furthermore, we have characterized monolayer surface properties of custom tailored polymers with varied block length for biomimetic membrane applications, as well as developed a multiwell microelectromechanical-system-based membrane testing platform for enhanced versatility in film deposition. We have successfully demonstrated the reconstitution of a genetically engineered OmpF porin in block copolymer-based biomembranes, fabrication of large-area hybrid protein-polymer Langmuir-Blodgett films, as well as protein insertion via macromolecule detection using protein-polymer active materials with the goal of buildup toward a multicomponent microsystem while preserving inherent molecular function.
The Corrosion of Carbon Black Anodes in Alkaline Electrolyte I . Acetylene Black and the Effect of Cobalt Catalyzation

14C labeling of acetylene black was used together with mass spectroscopic analysis of the gas evolved to determine the current efficiencies for oxygen evolution, carbon dissolution, and carbon gasification (to carbon monoxide). The current efficiencies were found to depend dramatically on potential, temperature, and the presence of an evolution catalyst like . On uncatalyzed black, three regimes could be distinguished: (i) at potentials below 500 mV vs. and temperatures below 50°C, carbon dissolution is the primary anodic process, (ii) at 500–600 mV and 50°C or lower, carbon dissolution and oxygen evolution occur at equivalent rates, and (iii) above ca. 600 mV or above ca. 60°C, oxygen evolution and gasification of the carbon to carbon monoxide are the dominant processes. Catalyzation with collapsed these regimes so that all three anodic processes are concurrent throughout the potential region of interest, and the overall rate of corrosion increased significantly. In addition, catalyzation caused the production of organic products (ca. 5% current efficiency) in a potential region where none is produced from acetylene black alone. The mechanism of action of on the acetylene black corrosion is not yet understood, but there is evidence that direct physical contact between the particles and carbon particles is not required to produce accelerated corrosion of the carbon.
Implementing real-time robotic systems using CHIMERA II

A description is given of the CHIMERA II programming environment and operating system, which was developed for implementing real-time robotic systems. Sensor-based robotic systems contain both general- and special-purpose hardware, and thus the development of applications tends to be a time-consuming task. The CHIMERA II environment is designed to reduce the development time by providing a convenient software interface between the hardware and the user. CHIMERA II supports flexible hardware configurations which are based on one or more VME-backplanes. All communication across multiple processors is transparent to the user through an extensive set of interprocessor communication primitives. CHIMERA II also provides a high-performance real-time kernel which supports both deadline and highest-priority-first scheduling. The flexibility of CHIMERA II allows hierarchical models for robot control, such as NASREM, to be implemented with minimal programming time and effort. >
Rate-maximizing power allocation in OFDM based on partial channel knowledge

Power loading algorithms improve the data rates of orthogonal frequency division multiplexing (OFDM) systems. However, they require the transmitter to have perfect channel state information, which is impossible in most wireless systems. We investigate the effects of imperfect (and thus partial) channel feedback on the throughput of OFDM systems. Two channel uncertainty models are studied: 1) the ergodic model, where average rate is the figure of merit and 2) the quasi-static model, where outage rate is relevant. Rate-power allocation algorithms are developed. The throughput achieved by these algorithms and the effects of channel multipath are investigated analytically and with simulations.
Infrared photochemistry of cyclobutyl chloride

The decomposition of cyclobutyl chloride following multiple infraredphoton excitation has been investigated. The primary photolysis products are butadiene, from elimination of HCl, and ethylene and vinyl chloride, fromring scission. The vinyl chloride undergoes secondary decomposition to acetylene and HCl. In addition to these products, known from thermal VLPP experiments, we also find 1-butene, which may arise from a higher energy CCl homolysis channel. Collisions with either reactant molecules oradded buffer gas lead to cooling of the laser-produced vibrational energy distributions. The average amount of energy removed per collision is 15–20 kcal/mol for self-collisions and 2–4 kcal/mol with argon.
Active internet traffic filtering: real-time response to denial-of-service attacks

This paper describes Active Internet Traffic Filtering (AITF), a mechanism for blocking highly distributed denial-of-service (DDoS) attacks. These attacks are an acute contemporary problem, with few practical solutions available today; we describe in this paper the reasons why no effective DDoS filtering mechanism has been deployed yet. We show that the current Internet's routers have sufficient filtering resources to thwart such attacks, with the condition that attack traffic be blocked close to its sources; AITF leverages this observation. Our results demonstrate that AITF can block a million-flow attack within seconds, while it requires only tens of thousands of wire-speed filters per participating router -- an amount easily accommodated by today's routers. AITF can be deployed incrementally and yields benefits even to the very first adopters.
Low Level of Brain Dopamine D2 Receptors in Methamphetamine Abusers: Association With Metabolism in the Orbitofrontal Cortex

OBJECTIVE: The role of dopamine in the addictive process (loss of control and compulsive drug intake) is poorly understood. A consistent finding in drug-addicted subjects is a lower level of dopamine D2 receptors. In cocaine abusers, low levels of D2 receptors are associated with a lower level of metabolism in the orbitofrontal cortex. Because the orbitofrontal cortex is associated with compulsive behaviors, its disruption may contribute to compulsive drug intake in addicted subjects. This study explored whether a similar association occurs in methamphetamine abusers. METHOD: Fifteen methamphetamine abusers and 20 non-drug-abusing comparison subjects were studied with positron emission tomography (PET) and [11C]raclopride to assess the availability of dopamine D2 receptors and with [18F]fluorodeoxyglucose to assess regional brain glucose metabolism, a marker of brain function. RESULTS: Methamphetamine abusers had a significantly lower level of D2 receptor availability than comparison subjects (a differenc...
Preparation of C9-aldehyde via aldol condensation reactions in ionic liquid media

C9-aldehyde has been prepared via aldol condensation reactions in ionic liquid media; catalyst investigation showed enhanced product selectivity for the desired aldehyde in ionic liquid media than in conventional solvent systems.
How Changes In Washington University’s Medicare Coordinated Care Demonstration Pilot Ultimately Achieved Savings

As one of the initial fifteen participants in the Medicare Coordinated Care Demonstration, the Washington University School of Medicine in St. Louis was not able to demonstrate any reduction in hospitalizations or Medicare spending for the patients it served. In fact, the Washington University program increased total Medicare spending by 12 percent. But after a redesign, the results changed. The program stopped conducting care management of most of its patients via telephone from a remote site in California and, instead, served all patients through frequent phone and occasional in-person contact from local care managers in St. Louis. Care management efforts were focused especially on patients deemed at greatest risk of hospitalization, and stronger hospital transition planning and medication reconciliation were provided, among other changes. After that point, the program reduced hospitalizations by 12 percent and monthly Medicare spending by $217 per enrollee—more than offsetting the program’s monthly $15...
A data-driven statistical framework for post-grasp manipulation

Grasping an object is usually only an intermediate goal for a robotic manipulator. To finish the task, the robot needs to know where the object is in its hand and what action to execute. This paper presents a general statistical framework to address these problems. Given a novel object, the robot learns a statistical model of grasp state conditioned on sensor values. The robot also builds a statistical model of the requirements for a successful execution of the task in terms of uncertainty in the state of the grasp. Both of these models are constructed by offline experiments. The online process then grasps objects and chooses actions to maximize likelihood of success. This paper describes the framework in detail, and demonstrates its effectiveness experimentally in placing, dropping, and insertion tasks. To construct statistical models, the robot performed over 8,000 grasp trials, and over 1,000 trials each of placing, dropping, and insertion.
The bricklayer problem and the Strong Cycle Lemma

1. THE PROBLEM. One of the most familiar brand names in the world of toys is LegoTM; the name immediately brings interlocking building blocks to mind. Interlocking blocks fit together in restricted ways. Typically, a block of order q (length q + 1) has q + 1 protrusions on its top and q + 1 indentations on its bottom, so that the indentations on the bottom of one block can lock on to the protrusions on the top of another. Here q is a positive integer, and the width and height of a block are unimportant. For q = 1 and q = 2, Figure 1 shows the q ways in which one block can sit on top of two others.
A case for water utilities as cooperatives and the UK experience

This article explores the creation of consumer cooperatives as a means of privatizing water utilities. The first section examines the structure of ownership and sets out Hansmann's theoretical basis for determining which category of persons is most efficiently assigned ownership. The section extends the discussion of market contracting costs by considering the externalities and social costs associated with a water utility. The heart of the paper is the second section which applies the theory of efficiently assigned ownership to the case of water utilities. The third section briefly reviews the literature on the relative efficiency of private and public utilities and also succinctly applies the theory of the firm to the question of vertical integration in the case of water utilities. The fourth section discusses the UK's experience with water utilities. The final section draws together the paper's conclusions. The application of Hansmann's general theoretical scheme for assigning ownership leads to the conclusion that water utilities should be consumer cooperatives. Consumer-owned utilities would confront lower market contracting and ownership costs, than would investor-owned utilities. Additionally, the social costs and externalities that are particular to water are better left to consumers who are more prone to take them into account in their decisions.
Microstructural Analysis in Processing of the High‐Tc Superconductor Ba2YCu3O7‐x in Air

In the synthesis of the superconducting compound Ba2YCu3O7-x from a stoichiometric mixture containing BaCO3, Y2O3, and CuO In air, a low-melting liquid phase is formed at about 890°C. The liquid phase was identified as a ternary eutectic located within the compatibility triangle Ba2YCu3O7-x–BaCuO2–CuO. The implication of this finding for the processing of Ba2YCu3O7-x is discussed.
Stereoselective Synthesis of Photoreactive Peptidomimetic γ-Secretase Inhibitors

The first asymmetric synthesis of novel, potent photoreactive γ-secretase inhibitors 2 and 3 has been accomplished. Two stereoselective methods for the preparation of lactone 9 are described. Protected benzophenone intermediate 19 is prepared via an aldol-elimination reaction followed by a PtO2-catalyzed asymmetric hydrogenation. Two routes leading from 19 to compounds 2 and 3 are evaluated. The application of 3 as an activity-based probe has been demonstrated by localizing γ-secretase activity in the plasma membrane of intact cells.
Exemplification effects: responses to perceptions of risk

Exemplification theory asserts that message components that are iconic and emotionally arousing are easily accessed, and are therefore relied upon when making subsequent behavioral decisions. A reanalysis of data from three studies collected at different times, unrelated experimental stimuli (terrorism, food ingredients, and bed bugs), different media (visual and print), varying geographic locations, different experimental conditions (laboratory and online), and diverse participants suggests that these processes work differently for men and women. Results suggest that the medium through which an exemplar is presented and/or experienced may be fairly inconsequential, but there are underlying processes which may determine the extent to which individuals will modify behavioral intentions related to risks. After witnessing exemplified portrayals, women were more likely than men to express a desire to modify behavior, perceive themselves as more susceptible to the risk, and perceive the risk as being more seve...
3-D statistical channel model for millimeter-wave outdoor mobile broadband communications

This paper presents an omnidirectional spatial and temporal 3-dimensional statistical channel model for 28 GHz dense urban non-line of sight environments. The channel model is developed from 28 GHz ultrawideband propagation measurements obtained with a 400 megachips per second broadband sliding correlator channel sounder and highly directional, steerable horn antennas in New York City. A 3GPP-like statistical channel model that is easy to implement in software or hardware is developed from measured power delay profiles and a synthesized method for providing absolute propagation delays recovered from 3-D ray-tracing, as well as measured angle of departure and angle of arrival power spectra. The extracted statistics are used to implement a MATLAB-based statistical simulator that generates 3-D millimeter-wave temporal and spatial channel coefficients that reproduce realistic impulse responses of measured urban channels. The methods and model presented here can be used for millimeter-wave system-wide simulations, and air interface design and capacity analyses.
Polymer-Supported Synthesis of Non-Oligomeric Natural Products.

The importance of natural product synthesis to the development of new synthetic methodology is well established. If the power of combinatorial chemistry is to be fully developed, solid-phase synthesis technology must be advanced. The recent polymer-supported synthesis of a series of natural products has paved the way for more complex reactions and the construction of molecules on the solid phase.
A unified filter for simultaneous input and state estimation of linear discrete-time stochastic systems

In this paper, we present a unified optimal and exponentially stable filter for linear discrete-time stochastic systems that simultaneously estimates the states and unknown inputs in an unbiased minimum-variance sense, without making any assumptions on the direct feedthrough matrix. We also provide the connection between the stability of the estimator and a system property known as strong detectability, and discuss the global optimality of the proposed filter. Finally, an illustrative example is given to demonstrate the performance of the unified unbiased minimum-variance filter.
Imperfect Information and Investor Inferences From Housing Price Dynamics

We examine characteristics of housing price dynamics that may be consistent with rational learning and not simply irrational feedback trading. We find significant patterns of temporal and spatial diffusion that are more amenable to explanations that allow for rational components. First, we execute our tests not simply on housing price changes, but on town-by-town differentials from regional average price changes. Second, we find significant relationships with own and neighboring town differentials, but not with control groups of non-neighboring towns. Third, we find that population density, a proxy for scale economies in information production, accelerates the diffusion process. Test were performed on quarterly data for large samples from Connecticut and the San Francisco area, employing method of moments estimators.
Absorption coefficients of quantum dot intermediate band material with negligible valence band offsets

Solar cells with quantum dot nanostructure absorbing medium have a potential to overcome single junction limit and achieve the solar energy conversion efficiency as high as 63%. The confined energy states in quantum dots can mediate the absorption of photons with energy lower than the band gap of the barrier material. Closely spaced array of quantum dots (QDs) can form a mini band due to electronic coupling of the confined states among the neighboring dots. Absorption properties of the quantum dot nanostructaures are different from that of a bulk material. For the detailed balance efficiency calculations, the absorption coefficients of the QD nanostructures are required for realistic QD structures. After finding out material combinations with negligible valence band offset for quantum dot intermediate band solar cells(QDIBSCs), present work is focused on the calculation of absorption coefficients of QD arrays. The confined electronic states are calculated with the effective mass theory for single and coupled quantum dots. The electronic coupling of the ground states of an array of quantum dots is calculated for negligible valence band offset material combinations (especially InAs dots in GaAs (0.84) Sb (0.16) matrix grown on [001] GaAs substrate). The intermediate bandwidth vs the veretical interdot separation is presented. For some suitable interedot separation, the absorption coefficients are calculated for valence band to intermediate band, Intermediate band to conduction band transitions.
Are the Bankrupt Skies the Friendliest

Abstract We use data from the US airline industry to investigate whether firms that are under bankruptcy protection, as well as these firm's product market rivals, change the quality of the products they offer. We measure the quality of the services offered by a carrier using flight cancelations and delays, and the age of the aircraft used by the carrier. We find that delays and cancelations are less frequent during bankruptcy filings but return to their pre-bankruptcy levels once the bankrupt firm emerges from bankruptcy. We also find that firms use Chapter 11 filings to permanently reduce the age of their fleet. We do not find evidence of statistically and economically significant changes by the airline's competitors along any of the dimensions above.
Patents and Appropriation: Concerns and Evidence

For over the past twenty years, the United States has witnessed a pro-patent movement. In response, numerous concerns have been raised, including possible impediments to innovation in cumulative technologies, emergence of anti-commons, barriers to entry and an elevation of costs of innovation associated with defensive patenting, growth in patent litigation and poor quality patents. Although there is little systematic evidence that these concerns have materialized in any substantial way, vigilance is nonetheless warranted.
Evolution favors protein mutational robustness in sufficiently large populations

An important question is whether evolution favors properties such as mutational robustness or evolvability that do not directly benefit any individual, but can influence the course of future evolution. Functionally similar proteins can differ substantially in their robustness to mutations and capacity to evolve new functions, but it has remained unclear whether any of these differences might be due to evolutionary selection for these properties. Here we use laboratory experiments to demonstrate that evolution favors protein mutational robustness if the evolving population is sufficiently large. We neutrally evolve cytochrome P450 proteins under identical selection pressures and mutation rates in populations of different sizes, and show that proteins from the larger and thus more polymorphic population tend towards higher mutational robustness. Proteins from the larger population also evolve greater stability, a biophysical property that is known to enhance both mutational robustness and evolvability. The excess mutational robustness and stability is well described by mathematical theory, and can be quantitatively related to the way that the proteins occupy their neutral network. Our work is the first experimental demonstration of the general tendency of evolution to favor mutational robustness and protein stability in highly polymorphic populations. We suggest that this phenomenon could contribute to the mutational robustness and evolvability of viruses and bacteria that exist in large populations.
Acceleration of multiple‐scattering, hyperspectral radiative transfer calculations via low‐streams interpolation

[1] A new generation of near-infrared instruments, such as the Greenhouse Gases Observing Satellite (GOSAT) and the ill-fated Orbiting Carbon Observatory (OCO), aims to measure concentrations of trace gases through the high-resolution measurements of spectra of reflected sunlight. Accurate retrievals of trace gas amounts from these data present a computational challenge for the underlying radiative transfer algorithms because these algorithms must simulate the angle-dependent radiances at high spectral resolution within near-infrared gas absorption bands in scattering atmospheres. Such calculations can be prohibitively expensive for certain applications. Building upon previous work by others, we describe a simple yet accurate technique to accelerate the radiative transfer of many monochromatic wavelengths in the visible and near infrared. It is tested over a large variety of profile types, including cases with high solar zenith angle, large amounts of atmospheric scattering, highly polarizing, non-Lambertian surfaces, and bands with overlapping gases. Speed gains of 1–2 orders of magnitude are demonstrated, with typical errors less than 0.1% for most atmospheres and less than 0.5% for even the most challenging cases.
Normal-coordinate structural decomposition and the vibronic spectra of porphyrins

The connection is made between macrocycle deformations obtained from normal-coordinate structural decomposition (NSD) and the vibronic molecular states and spectra of porphyrins. NSD is a procedure that provides a description of the time-averaged distortion of a porphyrin in terms of normal-coordinate displacements from a D4h symmetric reference structure. Expressions for the optical absorption spectra with vibrational structure are developed with these NSD-determined deformations as parameters. Using these expressions, the effects of macrocycle distortion on the UV-vis absorption spectra of porphyrins are determined.
Bromolactonization of alkenoic acids mediated by V2O5 via bromide to bromenium in situ oxidation

Abstract An efficient protocol for the bromolactonization of alkenoic acids is presented that obviates the use of molecular bromine or exogenous bromenium sources. Vanadium (V) oxide catalyzes the in situ oxidation of bromide salts to bromenium (Br + ) in a process mediated by urea–hydrogen peroxide complex. Initial mechanistic investigations indicate that the presence of urea does not accelerate the halolactonization reaction.
Formal verification of the NASA runway safety monitor

The runway safety monitor (RSM) designed by Lockheed Martin is part of NASA’s effort to reduce aviation accidents. We developed a Petri net model of the RSM protocol and used the model checking functions of our tool (stochastic and model checking analyzer for reliability and timing) SMART (Stochestic and model checking analyses for seliability and tunnig) to investigate a number of safety properties for the RSM. To mitigate the impact of state-space explosion, we built a highly discretized model of the system, obtained by partitioning the monitored runway zone into a grid of smaller volumes and by considering scenarios involving only two aircraft. The model also assumes that there are no communication failures, such as bad input from radar or lack of incoming data, thus it relies on a consistent view of reality by all participants. In spite of these simplifications, we were able to expose potential problems in the conceptual design of RSM. Our findings were forwarded to the design engineers, who undertook corrective action. Additionally, the results stress the efficiency attained by the new model checking algorithms implemented in SMART, and demonstrate their applicability to real-world systems. Attempts to verify RSM with similar NuSMV and SPIN models have failed due to excessive memory consumption.
A novel minimal in vitro system for analyzing HIV-1 Gag mediated budding

A biomimetic minimalist model membrane was used to study the mechanism and kinetics of cell-free in vitro HIV-1 Gag budding from a giant unilamellar vesicle (GUV). Real-time interaction of Gag, RNA, and lipid, leading to the formation of mini-vesicles, was measured using confocal microscopy. Gag forms resolution-limited punctae on the GUV lipid membrane. Introduction of the Gag and urea to a GUV solution containing RNA led to the budding of mini-vesicles on the inside surface of the GUV. The GUV diameter showed a linear decrease in time due to bud formation. Both bud formation and decrease in GUV size were proportional to Gag concentration. In the absence of RNA, addition of urea to GUVs incubated with Gag also resulted in subvesicle formation. These observations suggest the possibility that clustering of GAG proteins leads to membrane invagination even in the absence of host cell proteins. The method presented here is promising, and allows for systematic study of the dynamics of assembly of immature HIV and help classify the hierarchy of factors that impact the Gag protein initiated assembly of retroviruses such as HIV.
Generation and manipulation of squeezed states of light in optical networks for quantum communication and computation

We analyse a fiber-optic component which could have multiple uses in novel information processing systems utilizing squeezed states of light. Our approach is based on the phenomenon of photon-number squeezing of soliton noise after the soliton has propagated through a nonlinear optical fiber. Application of this component in optical networks for quantum computation and quantum cryptography are discussed.
Beyond the National Narrative: Implications of Reunification for Recent German History

This essay addresses the interpretative implications of German unification. It first suggests that the explanatory challenge is to trace the precise interaction between the international framework of detente and the internal dynamics of the democratic awakening. It then posits that part of the history of the years 1990–2010 in Germany, sometimes referred to as the ‘Berlin Republic’, can be understood as working out the consequences of unification; but a growing part is also composed of other issues such as globalization, immigration and educational reform. And it finally argues that the resumption of the national narrative is a backward-looking perspective that blocks the recognition of more recent problem areas that cannot be dealt with by telling a success story about the Federal Republic, but require an engagement with issues of postmodern modernity.