cssi/SciSciGPT-SciSciNet huggingface dataset:
Adaptive multiconfigurational wave functions

A method is suggested to build simple multiconfigurational wave functions specified uniquely by an energy cutoff Λ. These are constructed from a model space containing determinants with energy relative to that of the most stable determinant no greater than Λ. The resulting Λ-CI wave function is adaptive, being able to represent both single-reference and multireference electronic states. We also consider a more compact wave function parameterization (Λ+SD-CI), which is based on a small Λ-CI reference and adds a selection of all the singly and doubly excited determinants generated from it. We report two heuristic algorithms to build Λ-CI wave functions. The first is based on an approximate prescreening of the full configuration interaction space, while the second performs a breadth-first search coupled with pruning. The Λ-CI and Λ+SD-CI approaches are used to compute the dissociation curve of N2 and the potential energy curves for the first three singlet states of C2. Special attention is paid to the issue of energy discontinuities caused by changes in the size of the Λ-CI wave function along the potential energy curve. This problem is shown to be solvable by smoothing the matrix elements of the Hamiltonian. Our last example, involving the Cu2O2(2+) core, illustrates an alternative use of the Λ-CI method: as a tool to both estimate the multireference character of a wave function and to create a compact model space to be used in subsequent high-level multireference coupled cluster computations.
Subtypes of the Muscarinic Receptor in Smooth Muscle

Muscarinic receptors are expressed in smooth muscle throughout the body. In most instances, the muscarinic receptor population in smooth muscle is composed of mainly the M2 and M3 subtypes in an 80% to 20% mixture. The M3 subtype mediates phosphoinositide hydrolysis and calcium mobilization, whereas the M2 subtype mediates an inhibition of cAMP accumulation. In addition, a variety of ionic conductances are elicited by muscarinic receptors. Muscarinic agonists stimulate a nonselective cation conductance that is pertussis toxin-sensitive and dependent on calcium. The pertussis toxin-sensitivity of this response suggests that it is mediated by M2 receptors. Following agonist induced depolarization of smooth muscle, voltage dependent calcium channels are activated to enable an influx of calcium. In some instances, muscarinic agonists enhance this conductance through a mechanism involving protein kinase C, whereas in other instances, muscarinic agonists suppress this calcium conductance. Smooth muscle often contains calcium activated potassium channels that tend to repolarize the membrane following calcium influx. Activation of muscarinic receptors suppresses this potassium conductance in some smooth muscles. Under standard conditions, muscarinic agonists elicit pertussis toxin-insensitive contractions through activation of the M3 receptor. When most of the M3 receptors are inactivated, it is possible to measure a pertussis toxin-sensitive contractile response to muscarinic agonists that is most likely mediated through M2 receptors. M2 receptors also cause an indirect contraction by inhibiting the relaxant effects of agents that increase cAMP (e.g., forskolin and isoproterenol).
UNDERSTANDING THE PARTICLE PRODUCTION MECHANISM WITH CORRELATION STUDIES USING LONG AND SHORT RANGE CORRELATIONS

Long range forward-backward multiplicity correlations have been measured with the STAR detector for Au+Au collisions at $\sqrt{s_{NN}} = 200\, {\rm GeV}$. Strong long range correlations are observed in central Au+Au collisions. Based on the Dual Parton model and Color Glass Condensate considerations the data suggests that these long range correlations are due to multiple parton interactions. This suggests that dense partonic matter is created in central Au+Au collisions at $\sqrt{s_{NN}} = 200\, {\rm GeV}$.
Phonon laser action in a tunable, two-level system

We demonstrate a compound optical microcavity system, coupled to a radio-frequency mechanical mode, operating in close analogy to a two-level laser. Inversion produces gain, causing phonon laser action above a pump threshold of 7 µW.
Visible continuous emission from a silica microphotonic device by third-harmonic generation

Visible continuous emission from a silica microphotonic device by third-harmonic generation
Spatial patterns of sound propagation in sand.

This paper addresses the problem of how sound propagates in a granular medium composed of noncohesive particles. This propagation has many unusual aspects which are due to the fragile nature of the contacts between grains. Sound propagation in a granular material is very sensitive to the exact position of each of the grains. The thermal expansion of a single bead of about 3000 \AA{} can produce a change as large as 25% in the total transmission of the sound even though this expansion is 4 to 5 orders of magnitude smaller than the wavelength of the sound or the size of a bead (5 mm). I interpret this as being due to sound propagating predominantly along force chains within the medium. By replacing some of the beads with local heaters, I have used this effect to investigate the spatial properties of the low-amplitude vibrations. The disturbance of a single heater can be characterized by a time scale ${\mathrm{\ensuremath{\tau}}}_{\mathit{h}}$ which reveals the elapsed time of the signal traveling along a path via the heater. Two heaters placed symmetrically with respect to the source and detector can produce very different disturbances. Finally, I show that the spatial pattern caused by heaters placed at different positions within the medium is very irregular in that two adjacent heaters can give very different responses. These experiments all indicate the presence of strong inhomogeneities and the existence of force chains within the medium along which the sound predominantly travels.
Roche's Clinical Trials with Organs from Prisoners: Does Profit Trump Morals?

This case study discusses the economic, legal, and ethical considerations for conducting clinical trials in a controversial context. In 2010, pharmaceutical giant Roche received a shame award by the Swiss non-governmental organization Berne Declaration and Greenpeace for conducting clinical trials with organs taken from executed prisoners in China. The company respected local regulations and industry ethical standards. However, medical associations condemned organs from executed prisoners on moral grounds. Human rights organizations demanded that Roche ended its clinical trials in China immediately. Students are expected to review the economic and ethical issues regarding the outsourcing of clinical trials to controversial human rights contexts, and discuss how to make business decisions when there are conflicts between making profit and ethical considerations. Was Roche complicit in the human rights violations that were related to its clinical trials? Future patients might benefit from these clinical trials. Do profit and the greater good, in general, trump morals?
Preparation of Annulated 2,4-Dioxygenated-5-Methylfurans

Abstract A concise route from dihydropyran to the furans 12 and 13 has been developed that takes advantage of the regioselective Baeyer-Villiger oxidation of bicyclic ketone 6.
Internal flow characteristics of simplex swirl atomizers

The influences of main dimensions and operating conditions of simplex swirl atomizers on the thickness of the annular liquid film formed at the discharge orifice are examined. A general expression for film thickness is derived which, when compared with the experimental measurements reported in the literature, shows very satisfactory agreement over wide ranges of atomizer dimensions and liquid injection pressures. When measured values of Sauter mean diameter (SMD) are plotted against the corresponding values of liquid film thickness t, a relationship between SMD and t is obtained which corresponds closely to the results of previous studies on both airblast and simplex atomizers. The analysis also leads to the development of correlations for flow number and discharge coefficient in terms of the main nozzle dimensions. Predictions of flow number and discharge coefficient based on these equations show satisfactory agreement with the experimental results reported in the literature.
The Effects of Monetary Policy “News” and “Surprises”

There is substantial agreement in the monetary policy literature over the effects of exogenous monetary policy shocks. The shocks that are investigated, however, almost exclusively represent unanticipated changes in policy, which surprise the private sector and which are typically found to have a delayed and sluggish effect on output. In this paper, we estimate a New Keynesian model that incorporates news about future policies to try to disentangle the anticipated and unanticipated components of policy shocks. The paper shows that the conventional estimates confound two distinct effects on output: an effect due to unanticipated or “surprise” shocks, which is smaller and more short-lived than the response usually obtained in the literature, and a large, delayed, and persistent effect due to anticipated policy shocks or “news.” News shocks play a larger role in influencing the business cycle than unanticipated policy shocks, although the overall fraction of economic fluctuations that can be attributed to monetary policy remains limited.
Comments on Hydrophile–Lipophile Balance Systems

Griffin established the hydrophile-lipophile balance (HLB) system to classify nonionic surfactants and to select them as emulsifiers. For surfactants whose only hydrophilic moiety is polyoxyethylene, he developed the following relationship: HLB G =E/5 where E is the weight percent of ethylene oxide of the surfactant molecule and subscript G refers to Griffin
Are Supershells Powered by Multiple Supernovae? Modeling the Radio Pulsar Population Produced by OB Associations

Traditional searches for radio pulsars have targeted individual small regions such as supernova remnants or globular clusters or have covered large contiguous regions of the sky. None of these searches have been specifically directed toward giant supershells, some of which are likely to have been produced by multiple supernova (SN) explosions from an OB association. Here we perform a Monte Carlo simulation of the pulsar population associated with supershells powered by multiple SNe. We predict that several tens of radio pulsars associated with the largest Galactic supershells (with kinetic energies 1053 ergs) could be detected with current instruments and a few pulsars associated with the smaller supershells. We test these predictions for some of the supershells that lie in regions covered by past pulsar surveys. For the smaller supershells, our results are consistent with the few detected pulsars per bubble. For the giant supershell GSH 242-03+37, we find the multiple SN hypothesis inconsistent with current data at the ~95% level. We stress the importance of undertaking deep pulsar surveys in correlation with supershells. Failure to detect any pulsar enhancement in the largest of them would put serious constraints on the multiple SN origin for them. Conversely, the discovery of the pulsar population associated with a supershell would allow a different, independent approach to the study of pulsar properties.
Velocity reversal and the arrows of time

Agendanken experiment is proposed for distinguishing between two models accounting for the macroscopic arrow of time. The experiment involves the veloeity revesal of components of an isolated system, and the two models give contrasting predictions as to its behavior.
Thorn-forking in continuous logic

We study thorn forking and rosiness in the context of continuous logic. We prove that the Urysohn sphere is rosy (with respect to finitary imaginaries), providing the first example of an essentially continuous unstable theory with a nice notion of independence. In the process, we show that a real rosy theory which has weak elimination of finitary imaginaries is rosy with respect to finitary imaginaries, a fact which is new even for discrete first-order real rosy theories.
Amaranzoles B-F, imidazole-2-carboxy steroids from the marine sponge Phorbas amaranthus. C24-N- and C24-O-analogues from a divergent oxidative biosynthesis.

Five new steroidal imidazoles, amaranzoles B−F, were isolated from extracts of the marine sponge Phorbas amaranthus along with the known amaranzole A. The C24-N-(4-p-hydroxyphenyl)imidazol-5-yl constitution found in amaranzoles A, C, and D is replaced by a C24-O-(4-p-hydroxyphenyl)imidazole-2-carboxylate motif in amaranzoles B, E, and F. The structures were elucidated by interpretation of spectroscopic data. The C24 side chain configuration was assigned by synthesis of a model ester followed by chiroptical comparisons of its CD spectrum with that of an amaranzole B derivative.
Entanglement entropy of nontrivial states

Abstract We study the entanglement entropy arising from coherent states and one-particle states. We show that it is possible to define a finite entanglement entropy by subtracting the vacuum entropy from that of the considered states, when the unobserved region is the same.
LINEAR STABILITY OF RING SYSTEMS

We give a self-contained modern linear stability analysis of a system of n equal-mass bodies in circular orbit about a single more massive body. Starting with the mathematical description of the dynamics of the system, we form the linear approximation, compute all of the eigenvalues of the linear stability matrix, and finally derive inequalities that guarantee that none of these eigenvalues have a positive real part. In the end we rederive the result that Maxwell found for large n in his seminal paper on the nature and stability of Saturn's rings, which was published 150 years ago. In addition, we identify the exact matrix that defines the linearized system even when n is not large. This matrix is then investigated numerically (by computer) to find stability inequalities. Furthermore, using properties of circulant matrices, the eigenvalues of the large 4n × 4n matrix are computed by solving n quartic equations, which further facilitates the investigation of stability. Finally, we implement an n-body simulator, and we verify that the threshold mass ratios that we derive mathematically or numerically do indeed identify the threshold between stability and instability. Throughout the paper we consider only the planar n-body problem so that the analysis can be carried out purely in complex notation, which makes the equations and derivations more compact, more elegant, and therefore, we hope, more transparent. The result is a fresh analysis that shows that these systems are always unstable for 2 ≤ n ≤ 6, and for n > 6 they are stable provided that the central mass is massive enough. We give an explicit formula for this mass-ratio threshold.
Severe thunderstorms and climate change

As the planet warms, it is important to consider possible impacts of climate change on severe thunderstorms and tornadoes. To further that discussion, the current distribution of severe thunderstorms as a function of large-scale environmental conditions is presented. Severe thunderstorms are much more likely to form in environments with large values of convective available potential energy (CAPE) and deep-tropospheric wind shear. Tornadoes and large hail are preferred in high-shear environments and non-tornadic wind events in low shear. Further, the intensity of tornadoes and hail, given that they occur, tends to be almost entirely a function of the shear and only weakly depends on the thermodynamics. Climate model simulations suggest that CAPE will increase in the future and the wind shear will decrease. Detailed analysis has suggested that the CAPE change will lead to more frequent environments favorable for severe thunderstorms, but the strong dependence on shear for tornadoes, particularly the strongest ones, and hail means that the interpretation of how individual hazards will change is open to question. The recent development of techniques to use higher-resolution models to estimate the occurrence of storms of various kinds is discussed. Given the large interannual variability in environments and occurrence of events, caution is urged in interpreting the observational record as evidence of climate change.
Performance of an adaptive coding scheme in a fixed wireless cellular system working in millimeter-wave bands

This paper presents a solution to problem of providing bit- error rate performance guarantees in a fixed millimeter-wave wireless system, such as local multi-point distribution system in line-of-sight or nearly line-of-sight applications. The basic concept is to take advantage of slow-fading behavior of fixed wireless channel by changing the transmission code rate. Rate compatible punctured convolutional codes are used to implement adaptive coding. Cochannel interference analysis is carried out for downlink direction; from base station to subscriber premises. Cochannel interference is treated as a noise-like random process with a power equal to the sum of the power from finite number of interfering base stations. Two different cellular architectures based on using single or dual polarizations are investigated. Average spectral efficiency of the proposed adaptive rate system is found to be at least 3 times larger than a fixed rate system with similar outage requirements.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Cardiovascular disease in the elderly.

The current worldwide explosive increase in the numbers of older persons is unprecedented in history. In the 1990s and beyond, the preponderance of patients with cardiovascular illness will be elderly, with a substantial subset among the frail elderly, 85 years old and older. Cardiovascular disease remains the leading cause of death and disability in this population, and cardiovascular risk increases steadily with age. Pascal defined old age as "just a time that is farther from the beginning and nearer to the end." Elderly persons, with and without cardiovascular disease, vary widely in their physical, behavioral, cognitive, and emotional functioning; severity of illness; and expectations from medical care. The challenge to the clinical and research communities alike is to delineate the appropriate components of preventive, diagnostic, and therapeutic care for elderly cardiac patients in our society, interventions that are likely to relieve suffering, restore function so as to limit disability and dependency, and maintain a dignified and meaningful life-style for the end years of life. Major societal strides have been made in redefining both the onset of old age and its limitations. The eighteenth century poet, Robert Burns, wrote of his fears that he would be 45 years old at a time when life expectancy was 40 years; he saw himself as being weary, wrinkled, creeping, and joyless. For, ance that five-and-forty's speel'd, See crasy, weary, joyless Eild, Wi' wrinkled face, Comes hostin', hirplin', owre the field, Wi' creepin' pace. Burns died at the age of 37 years. A more attractive option is offered by Abraham Joshua Heschel, 1907-1972. According to all the standards we employ ... the aged person is condemned as inferior. ... Conditioned to operating as a machine for making and spending money, with all other relationships dependent upon its efficiency, the moment the machine is out of order and beyond repair, one begins to feel like a ghost without a sense of reality. ... Regarding himself as a person who has outlived his usefulness, he feels as if he has to apologize for being alive. May I suggest that ... old age be regarded not as the age of stagnation but as the age of opportunities for inner growth. ... The years of old age ... are indeed formative years, rich in possibilities to unlearn the follies of a lifetime, to see through inbred deceptions, to deepen understanding and compassion, to widen the horizon of honesty, to refine the sense of fairness.
Rough Gauge Fields, Smearing and Domain Wall Fermions

At a fixed lattice spacing, as determined by say m ρ , adding additional fermion flavors to a dynamical simulation produces rougher gauge field configurations at the lattice scale. For domain wall fermions, these rough configurations lead to larger residual chiral symmetry breaking and larger values for the residual masses, m res . We discuss ongoing attempts to reduce chiral symmetry breaking for N f = 3 dynamical domain wall fermion simulations by different smoothing choices for the gauge fields.
A numerical model for supersonic reacting mixing layers

A current research effort is underway at the NASA Langley Research Center to achieve a detailed understanding of important phenomena present when a supersonic flow undergoes a chemical reaction. A computer program has been developed to study the details of such flows. The program has been constructed to consider the multicomponent diffusion and convection of important species, the finite-rate reaction of these species, and the resulting interaction between the fluid mechanics and chemistry. Code results from the analysis of a spatially developing and reacting mixing layer are presented, and conclusions are drawn regarding the structure of the evolving layer and its associated flame.
Transitions in glasses at low temperatures.

Transitions in glasses at low temperatures, noting molecular relaxation dependence on copolymer composition
Decentralized Anonymous Credentials

Anonymous credentials provide a powerful tool for making assertions about identity while maintaining privacy. However, a limitation of today's anonymous credential systems is the need for a trusted credential issuer — which is both a single point of failure and a target for compromise. Furthermore, the need for such a trusted issuer can make it challenging to deploy credential systems in practice, particularly in the ad hoc network setting (e.g., anonymous peer-to-peer networks) where no single party can be trusted with this responsibility. In this work we propose a novel anonymous credential scheme that eliminates the need for a trusted credential issuer. Our approach builds on recent results in the area of electronic cash that, given a public append-only ledger, do not need a trusted credential issuer. Furthermore, given a distributed public ledger, as in, e.g., Bitcoin, our system requires no credential issuer at all and hence is decentralized. Using such a public ledger and standard cryptographic primitives, we propose and provide a proof of security for a basic anonymous credential system that allows users to make flexible identity assertions with strong privacy guarantees without relying on trusted parties. Finally, we discuss a number of practical applications for our techniques, including resource management in ad hoc networks and prevention of Sybil attacks. We implement our scheme and measure its efficiency.
Size-velocity distribution of large ejecta fragments

The characteristics of three primary extraterrestrial craters and the associated craters were examined to generate a size-velocity distribution for large ejecta fragments. The lunar craters Copernicus and Aristillus and the Martian crater Dv on Olympus Mons were used. Attention was focused on the radial distances between the primary and secondary crater centers and the diameters of the secondaries. The primary craters selected are all relatively young, which avoided contamination of the data from secondaries from other primaries. Attempts were made to account for the speed of the hypervelocity impacts and the elemental compositions of the impactors. An apparent velocity cutoff of about 1 km/sec was observed for the secondaries, which implies that no meteoroid impacts can accelerate ejecta to escape velocities from the moon or Mars.
Intermittent turbulence and turbulent structures in a linear magnetized plasma

Strongly intermittent turbulence is observed in the shadow of a limiter in the large plasma device at UCLA [W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)]. The amplitude probability distribution function of the turbulence is strongly skewed, with density depletion events (or “holes”) dominant in the high-density region and density-enhancement events (or “blobs”) dominant in the low-density region. Two-dimensional cross-conditional averaging shows that the blobs are detached, outward-propagating filamentary structures with a clear dipolar potential, while the holes appear to be part of a more extended turbulent structure. A statistical study of the blobs reveals a typical size of ten times the ion sound gyroradius and a typical velocity of one-tenth the sound speed.
High Speed Photography for Plasma Physics Research

For short duration plasmas, such as high-current theta and zeta pinches, it is necessary to use very short exposures to photograph the plasmas. These plasmas are very luminous, so there is sufficient light for sub-microsecond exposures. Several types of cameras were used. These include Kerr cell, image converter, framing and streak cameras. The Kerr cell camera takes only one picture, while the framing camera can take 25 pictures at the rate of 4x 10'6 per second. Examples of plasma photography will be shown, and the unique advantages and problems with each type of camera will be discussed.
Do Asset Fire Sales Exist? An Empirical Investigation of Commercial Aircraft Transactions

This paper uses commercial aircraft transactions to determine whether capital constraints cause firms to liquidate assets at discounts to fundamental values. Results indicate that financially constrained airlines receive lower prices than their unconstrained rivals when selling used narrow-body aircraft. Capital constrained airlines are also more likely to sell used aircraft to industry outsiders, especially during market downturns. Further evidence that capital constraints affect liquidation prices is provided by airlines' asset acquisition activity. Unconstrained airlines significantly increase buying activity when aircraft prices are depressed; this pattern is not observed for financially constrained airlines.
The Large Scale X-Ray Emission from M87

We describe asymmetrical features in a long exposure X-ray map of M87 made with the ROSAT High Resolution Imager (HRI). A bright triangular region is marked by a linear 'spur' along one edge. The structure of this spur suggests an interpretation of a tangential view of a shock front 18 kpc long. None of the brighter features are spatially coincident with radio or optical structures so we concur with earlier investigators that most of the emission arises from thermal processes.
Imaging and differentiation of mouse embryo tissues by ToF-SIMS

Abstract Time-of-flight secondary ion mass spectrometry (ToF-SIMS) equipped with a gold ion gun was used to image mouse embryo sections and differentiate tissue types (brain, spinal cord, skull, rib, heart and liver). Embryos were paraffin-embedded and then deparaffinized. The robustness and repeatability of the method was determined by analyzing ten tissue slices from three different embryos over a period of several weeks. Using principal component analysis (PCA) to reduce the spectral data generated by ToF-SIMS, histopathologically identified tissue types of the mouse embryos can be differentiated based on the characteristic differences in their mass spectra. These results demonstrate the ability of ToF-SIMS to determine subtle chemical differences even in fixed histological specimens.
Gulf Views: Toward A Better Understanding Of Viewshed Scope In Hedonic Property Models

This study examines the influence of Gulf of Mexico views on residential home sales prices in Pinellas County, Florida. We utilize Light Detection and Ranging (lidar) data to construct four continuous measures of Gulf of Mexico views—the total view, the maximum view segment, the mean view segment, and proximity to view content. Our results illustrate that residential property owners have a higher marginal willingness-to-pay for larger total views and larger continuous view segments. Results also indicate that the proximity of homes to the view content influences view valuations.
Subleading soft factor for string disk amplitudes

We investigate the behavior of superstring disk scattering amplitudes in the presence of a soft external momentum at finite string tension. We prove that there are no α′-corrections to the field theory form of the subleading soft factor S (1). At the end of this work, we also comment on the possibility to find the corresponding subleading soft factors in closed string theory using our result and the KLT relations.
Quantum dot cavity-QED in the presence of strong electron-phonon interactions

A quantum dot strongly coupled to a single high-finesse optical microcavity mode constitutes a new fundamental system for quantum optics. Here, the effect of exciton-phonon interactions on reversible quantum dot cavity coupling is analyzed without making a Born-Markov approximation. The analysis is based on a polaron operator technique that has been used to study the ``spin-boson'' Hamiltonian. For bulk acoustic phonons and for a large class of confined phonon models, we find that vacuum-Rabi splitting persists even in the presence of a large Stokes shift and at an appreciable temperature, but its magnitude is exponentially suppressed by the electron-phonon coupling strength.
A splitting theorem for holomorphic Banach bundles

This paper is motivated by Grothendieck’s splitting theorem. In the 1960s, Gohberg generalized this to a class of Banach bundles. We consider a compact complex manifold X and a holomorphic Banach bundle E → X that is a compact perturbation of a trivial bundle in a sense recently introduced by Lempert. We prove that E splits into the sum of a finite rank bundle and a trivial bundle, provided \({H^{1}(X, \mathcal {O})=0}\) .
A Novel Method for Sampling Alpha-helical Protein Backbones

Abstract We present a novel technique of sampling the configurations of helical proteins. Assuming knowledge of native secondary structure, we employ assembly rules gathered from a database of existing structures to enumerate the geometrically possible three-dimensional arrangements of the constituent helices. We produce a library of possible folds for 25 helical protein cores. In each case, our method finds significant numbers of conformations close to the native structure. In addition, we assign coordinates to all atoms for four of the 25 proteins and show that this has a small effect on the number of near-native conformations. In the context of database driven exhaustive enumeration our method performs extremely well, yielding significant percentages of conformations (between 0.02 % and 82 %) within 6 A of the native structure. The method's speed and efficiency make it a valuable tool for predicting protein structure.
Linear system identification via atomic norm regularization

This paper proposes a new algorithm for linear system identification from noisy measurements. The proposed algorithm balances a data fidelity term with a norm induced by the set of single pole filters. We pose a convex optimization problem that approximately solves the atomic norm minimization problem and identifies the unknown system from noisy linear measurements. This problem can be solved efficiently with standard, free software. We provide rigorous statistical guarantees that explicitly bound the estimation error (in the ℌ 2 -norm) in terms of the stability radius, the Hankel singular values of the true system and the number of measurements. These results in turn yield complexity bounds and asymptotic consistency. We provide numerical experiments demonstrating the efficacy of our method for estimating linear systems from a variety of linear measurements.
Complexity: a philosopher's reflections

It is sometimes thought that philosophers have little to offer those who think about the science of complex systems. There are, however, two philosophical ideas that seem crucial in considering the very definition of complexity. The first is the distinction between "ontology" and "epistemology", wherein one recognizes the difference between limits provided by reality versus those provided by our knowledge of reality. The second concerns the debate over "non-reductive materialism" in the philosophy of mind, wherein philosophers have discovered a way to defend non-reductive explanations of emergent phenomena, even though they are materially dependent upon causal relations at lower levels. In my paper, I argue that we may defend the science of complex systems as a project involving the explanation of non-reductive phenomena that are epistemically emergent.
Toward an integrated model of protein-DNA recognition as inferred from NMR studies on the Lac repressor system.

Sequence-specific protein-DNA interactions are responsible for the regulation of key biological functions such as replication of the genome, initiation of transcription, and repair of damaged DNA. All of these regulatory pathways are built on the foundation that proteins are able to bind selectively to a particular DNA site in the genome. The most challenging issue for specific protein-DNA recognition is that the target sequence is immersed in a huge molar excess of nonspecific DNA sequences, which also compete for the same protein. The distribution of protein between regulatory and nonspecific sequences determines the occupancy of the target site in the cell and, hence, the transcriptional activity of the corresponding promoter. The problem is much more acute than it is for other protein-ligand interactions, because obviously the protein cannot differentiate between these sites on the basis of their size or shape.1 For repressor molecules, such as the lactose (lac) repressor, the problem of finding the correct site is even more severe, as only a few copies ( 10) of the protein exist in the cell. Thus, to compete with the large excess of nonspecific genomic DNA, these proteins have evolved to bind with a very high specificity ratio ( 107).
Materials chemistry issues related to advanced materials applications in the automotive industry

The driving force behind the research on advanced materials has largely been aerospace and defense applications. In such applications the customer-induced limitations and infrastructural economic factors are secondary to the application-oriented parameters. Automobiles, on the other hand, represent the primary consumers of advanced materials in civilian applications. Automobiles are high-technology, low-cost machines which need to be robust for various climatic conditions and driver behavior. Advanced materials play an important role in the design and fabrication of various components of automobiles, and the use of new materials continues to increase. Recent interest in developing highly fuel efficient vehicles with low emissions has focused efforts toward materials, designs, and devices and is spurring research into advanced materials for weight reduction. The goal is to achieve fuel efficiency by weight reduction and a more efficient powertrain. In this review article, we summarize the efforts of the 19...
Derivation of remote sensing cut points for the screening of high-emitting vehicles

Remote sensing devices (RSDs) are considered supplementary tools to enhance existing inspection and maintenance (I/M) programs. Emission compliance is determined by comparing the concentration of pollutants measured by an RSD to on-road remote sensing (RS) emission standards. The literature shows that RS emission standards are insensitive to vehicle speed and acceleration levels even though vehicle emissions are highly affected by the engine load. Consequently, this study firstly proposes a procedure for constructing on-road remote-sensing emission standards that are sensitive to vehicle speed and acceleration levels using the VT-Micro models and the Comprehensive Modal Emission Models (CMEMs). Given the proposed remote-sensing cut points, a comparison to the existing cut points is presented as well as sample tests. The results of the sample tests demonstrate that the approach is effective for HE (high-emitting) 3 and 4 vehicles of the VT-Micro emission models and requires further enhancements for HE-1 and -2 vehicles.
Financial reporting and auditing under alternative damage apportionment rules

This article analyzes the impacts that three alternative damage apportionment rules have on an owner's financial‐reporting decision, an auditor's audit‐quality choice, and investors' pricing decisions within the context of a perfectly competitive securities market and owner solvency constraints. The strategic interactions between the players' strategies are analyzed within a setting where payoffs are endogenously determined and vary with the damage apportionment rule. These comparisons speak to potential changes resulting from the Private Securities Litigation Reform Act of 1995 which replaced joint‐and‐several liability with a proportionate liability rule. The main finding is that the audit failure rate can decrease when there is a switch from a joint‐and‐several to a proportional liability rule despite the fact that audit quality has also declined. This result occurs when there are strategic interactions between the owner's reporting strategy and the auditor's quality decision.
A "Second Coming"? The Return of German Political Theory

This article examines the political theories of Theodor Adorno and Hannah Arendt in light of shared theoretical concerns and the discussion generated by their recent centenaries (2003 and 2006, respectively). I argue that Adorno's tremendously influential critique of identity philosophies is of limited value when it comes to political thinking, in large part because he neglects to give serious thought to the problem of institutionalizing freedom. In contrast, the notion of human “plurality” is central to Arendt's political thought and is set within a rich conceptualization of the public realm and its legal and institutional preconditions.
Efficient two-step synthesis of methylphytylbenzoquinones: precursor intermediates in the biosynthesis of vitamin E

Abstract Methylphytylbenzoquinone was synthesized from δ-tocopherol by a simple two-step sequence. Oxidative cleavage of the benzopyran ring with cerium sulfate followed by dehydration using Burgess reagent afforded the methylphytylbenzoquinone as a mixture of positional and geometric isomers which were separated by HPLC. The biological activity of the product corresponds to the natural biosynthetic precursor of vitamin E. The above method is a general procedure applicable to the preparation of any of the tocopherol derivatives.
Nerve Injury Induces Gap Junctional Coupling among Axotomized Adult Motor Neurons

Neonatal spinal motor neurons are electrically and dye-coupled by gap junctions, but coupling is transient and disappears rapidly after birth. Here we report that adult motor neurons become recoupled by gap junctions after peripheral nerve injury. One and 4–6 weeks after nerve cut, clusters of dye-coupled motor neurons were observed among axotomized, but not control, lumbar spinal motor neurons in adult cats. Electrical coupling was not apparent, probably because of the electrotonic distance between dendrodendritic gap junctions and the somatic recording location. Analyses of gap junction protein expression in cat and rat showed that the repertoire of connexins expressed by normal adult motor neurons, Cx36, Cx37, Cx40, Cx43, and Cx45, was unchanged after axotomy. Our results suggest that the reestablishment of gap junctional coupling among axotomized adult motor neurons may occur by modulation of existing gap junction proteins that are constitutively expressed by motor neurons. After injury, interneuronal gap junctional coupling may mediate signaling that maintains the viability of axotomized motor neurons until synaptic connections are reestablished within their targets.
Asymmetric synthesis of 1,4-cycloheptadienes and bicyclo[3.2.1]octa-2,6-dienes by rhodium(II) N-(p-(tert-butyl)phenylsulfonyl)prolinate catalyzed reactions between vinyldiazomethanes and dienes

Rhodium(II) (S)-(N-p(tertbutyl)phenylsulfonyl)prolinate catalyzed decomposition of vinyldiazomethanes in the presence of dienes results in a tandem cyclopropanation/Cope rearrangement, leading to a general and enantioselective approach for the construction of seven-membered carbocycles.
Transfer efficiencies in guided wave electrooptic filters/mode converters

The influence of a spatially nonuniform electric field on the polarization Conversion efficiency of single- and multimode guided wave electrooptic filters is analyzed quantitatively, using coupled-mode theory. A single-mode graded-index surface waveguide filter is capable of essentially 100-percent transfer efficiency, with overlap integrals of field and a single TE, TM mode pair approaching 0.6 in Ti: LiNbO 3 . The thicker multi-mode slab waveguides require that spatial periods of applied field be considerably greater than the guide thickness to achieve high transfer efficiency, though never quite 100 percent; The best performance also requires focused coupling into the lowest order mode only. Experimental results with a LiTaO 3 slab waveguide filter show reasonable agreement with a multiple-coupled-mode solution.
Learning Mixtures of Ranking Models

This work concerns learning probabilistic models for ranking data in a heterogeneous population. The specific problem we study is learning the parameters of a Mallows Mixture Model. Despite being widely studied, current heuristics for this problem do not have theoretical guarantees and can get stuck in bad local optima. We present the first polynomial time algorithm which provably learns the parameters of a mixture of two Mallows models. A key component of our algorithm is a novel use of tensor decomposition techniques to learn the top-k prefix in both the rankings. Before this work, even the question of identifiability in the case of a mixture of two Mallows models was unresolved.
A general approach to the enantioselective α-oxidation of aldehydes via synergistic catalysis

A new enantioselective α-oxidation of aldehydes has been accomplished using TEMPO and a synergistic combination of copper and organic catalysis. Expanding upon recently reported mechanistic studies, these mild catalytic conditions provide stable aldehyde products bearing a wide array of electronically and sterically diverse substructures. The utility of these oxidized products is highlighted by subsequent derivatization to a variety of common chiral synthons, without loss in enantiopurity.
Negishi coupling in the synthesis of advanced electronic, optical, electrochemical, and magnetic materials

Negishi coupling is one of the most important modern organic synthetic methods for selective C–C bond formation, and has been extensively applied in the synthesis of organic electronic, optical, electrochemical, and magnetic materials. This report provides a critical overview of the efficiency and versatility of Negishi coupling as applied for synthesizing polymers, oligomers, and small molecules with a wide variety of structural features and various desirable functions for organic electronic, optoelectronic, and other advanced technologies.
Upregulation of zinc transporter 2 in the blood-CSF barrier following lead exposure.

Zinc (Zn) is an essential element for normal brain function; an abnormal Zn homeostasis in brain and the cerebrospinal fluid (CSF) has been implied in the etiology of Alzheimer's disease (AD). However, the mechanisms that regulate Zn transport in the blood- brain interface remain unknown. This study was designed to investigate Zn transport by the blood-CSF barrier (BCB) in the choroid plexus, with a particular focus on Zn transporter-2 (ZnT2), and to understand if lead (Pb) accumulation in the choroid plexus disturbed the Zn regulatory function in the BCB. Confocal microscopy, quantitative PCR and western blot demonstrated the presence of ZnT2 in the choroidal epithelia; ZnT2 was primarily in cytosol in freshly isolated plexus tissues but more toward the peripheral membrane in established choroidal Z310 cells. Exposure of rats to Pb (single ip injection of 50mg Pb acetate/kg) for 24h increased ZnT2 fluorescent signals in plexus tissues by confocal imaging and protein expression by western blot. Similar results were obtained by in vitro experiments using Z310 cells. Further studies using cultured cells and a two-chamber Transwell device showed that Pb treatment significantly reduced the cellular Zn concentration and led to an increased transport of Zn across the BCB, the effect that may be due to the increased ZnT2 by Pb exposure. Taken together, these results indicate that ZnT2 is present in the BCB; Pb exposure increases the ZnT2 expression in choroidal epithelial cells by a yet unknown mechanism and as a result, more Zn ions may be deposited into the intracellular Zn pool, leading to a relative Zn deficiency state in the cytoplasm at the BCB.
MPI and OpenMP Paradigms on Cluster of SMP Architectures: The Vacancy Tracking Algorithm for Multi-Dimensional Array Transposition

We investigate remapping multi-dimensional arrays on cluster of SMP architectures under OpenMP, MPI, and hybrid paradigms. Traditional method of array transpose needs an auxiliary array of the same size and a copy back stage. We recently developed an in-place method using vacancy tracking cycles. The vacancy tracking algorithm outperforms the traditional 2-array method as demonstrated by extensive comparisons. The independence of vacancy tracking cycles allows efficient parallelization of the in-place method on SMP architectures at node level. Performance of multi-threaded parallelism using OpenMP are tested with different scheduling methods and different number of threads. The vacancy tracking method is parallelized using several parallel paradigms. At node level, pure OpenMP outperforms pure MPI by a factor of 2.76. Across entire cluster of SMP nodes, the hybrid MPI/OpenMP implementation outperforms pure MPI by a factor of 4.44, demonstrating the validity of the parallel paradigm of mixing MPI with OpenMP.
Unveiling latent α-iminocarbene reactivity for intermolecular cascade reactions through alkyne oxidative amination.

The present protocol provides a metallonitrene/alkyne cascade which is terminated by ylide formation and [2,3] Wittig rearrangement.
Quantum shot noise in tunnel junctions

We present a model for shot noise in tunnel junctions, which is derived from the microscopic theory and fully contains quantum effects. In a simple limit of weak dissipation we can work out several experimentally observable quantities without any further approximation. We compare our results with those obtained from Gaussian-noise models, and with those derived from Langevin descriptions generalized to account for shot noise.
Generalization of Newton-Euler Formulation of Dynamic Equations to Nonrigid Manipulators

Generalisation de la formulation de Newton-Euler aux equations de la dynamique d'un manipulateur non rigide
Caution, Drivers! Children Present: Traffic, Pollution, and Infant Health

Abstract We investigate the effects of automobile congestion on ambient air pollution and local infant mortality rates using data from California spanning 2002 to 2007. Constructing instrumental variables (IV) using the relationship of traffic, weather conditions, and pollutants, we show that particulate matter, even at modern levels, has large marginal effects on weekly infant mortality rates, especially for premature or low birthweight infants. We also find suggestive evidence of large effects for carbon monoxide, though results are imprecise. Finally, we check estimate sensitivity to nonclassical measurement error in local pollution and show that our IV results are robust to such concerns.
Arbitrated address-event representation digital image sensor

An 80 × 60 pixels arbitrated address-event imager has been designed and fabricated in a 0.6 µm CMOS process. The output bandwidth is allocated according to the pixel's demand. The imager has a large dynamic range: 200 dB (pixel) and 120 dB (array). The power consumption is 3.4 mW in uniform indoor light. The imager is capable of 8.3K effective frames per second.