cssi/SciSciGPT-SciSciNet huggingface dataset:
A Chiral effective Lagrangian for nuclei

Abstract An effective hadronic lagrangian consistent with the symmetries of quantum chromodynamics and intended for applications to finite-density systems is constructed. The degrees of freedom are (valence) nucleons, pions and the low-lying non-Goldstone bosons, which account for the intermediate-range nucleon-nucleon interactions and conveniently describe the nonvanishing expectation values of nucleon bilinears. Chiral symmetry is realized nonlinearly, with a light scalar meson included as a chiral singlet to describe the mid-range nucleon-nucleon attraction. The low-energy electromagnetic structure of the nucleon is described within the theory using vector-meson dominance, so that external form factors are not needed. The effective lagrangian is expanded in powers of the fields and their derivatives, with the terms organized using Georgi's “naive dimensional analysis”. Results are presented for finite nuclei and nuclear matter at one-baryon-loop order, using the single-nucleon structure determined within the model. Parameters obtained from fits to nuclear properties show that naive dimensional analysis is a useful principle and that a truncation of the effective lagrangian at the first few powers of the fields and their derivatives is justified.
Viscosity and thermalization

I solve the relativistic Navier stokes equations assuming boost invariance and rotational symmetry. I compare the resulting numerical solutions for two limiting models of the shear viscosity. In the first model the shear viscosity is made proportional to the temperature. Thus, η ∝ T/σ0 where σ0 is some fixed cross section (perhaps σ0 ~ Λ−2QCD). This viscosity model is typical of the classical Boltzmann simulations of Gyulassy and Molnar. In the second model the shear viscosity is made proportional to T3. This model is typical of high temperature QCD. When the initial mean free path of the T3 model is four times larger than the T/σ0 model, the two models of viscosity produce the same radial flow. This result can be understood with simple scaling arguments. Thus, the large transport opacity needed in classical Boltzmann simulations is in part an artefact of the fixed scale σ0 in these models.
Typology of delivery quality: latent profile analysis of teacher engagement and delivery techniques in a school-based prevention intervention, keepin’ it REAL curriculum

Enhancing the delivery quality of school-based, evidence-based prevention programs is one key to ensuring uniform program effects on student outcomes. Program evaluations often focus on content dosage when implementing prevention curricula, however, less is known about implementation quality of prevention content, especially among teachers who may or may not have a prevention background. The goal of the current study is to add to the scholarly literature on implementation quality for a school-based substance use prevention intervention. Twenty-five schools in Ohio and Pennsylvania implemented the original keepin' REAL (kiR) substance use prevention curriculum. Each of the 10, 40-45 min lessons of the kiR curriculum was video recorded. Coders observed and rated a random sample of 276 videos reflecting 78 classes taught by 31 teachers. Codes included teachers' delivery techniques (e.g., lecture, discussion, demonstration and role play) and engagement with students (e.g. attentiveness, enthusiasm and positivity). Based on the video ratings, a latent profile analysis was run to identify typology of delivery quality. Five profiles were identified: holistic approach, attentive teacher-orientated approach, enthusiastic lecture approach, engaged interactive learning approach and skill practice-only approach. This study provides a descriptive typology of delivery quality while implementing a school-based substance use prevention intervention.
Collision‐induced dissociation of aluminum cluster ions: Fragmentation patterns, bond energies, and structures for Al+2–Al+7

Collision‐induced dissociation (CID) of cooled, mass selected aluminum cluster ions (Al+2–7) by xenon, has been studied over an energy range of 0–10 eV (center of mass). These experiments were carried out in a new apparatus which is described in detail. From the product branching ratios and cross section magnitudes we derive qualitative structural information about the cluster ions. The fragmentation thresholds are analyzed to yield dissociation energies, approximate ionization potentials, and further structural information about the cluster ions and their neutral counterparts. Cluster stabilities range from 0.85±0.40 eV for Al+4 to 2.25±0.70 eV for Al+7. The results provide a stringent test for recent calculations on Al2–6.
Pulsed laser triggered high speed microfluidic fluorescence activated cell sorter

We report a high speed and high purity pulsed laser triggered fluorescence activated cell sorter (PLACS) with a sorting throughput up to 20 000 mammalian cells s−1 with 37% sorting purity, 90% cell viability in enrichment mode, and >90% purity in high purity mode at 1500 cells s−1 or 3000 beads s−1. Fast switching (30 μs) and a small perturbation volume (∼90 pL) is achieved by a unique sorting mechanism in which explosive vapor bubbles are generated using focused laser pulses in a single layer microfluidic PDMS channel.
Incident dispatching, clearance and delay

This paper models response times and delays for highway incidents, accounting for spacing between interchanges and the time penalty for changing directions, enabling a response vehicle to reach an incident on the opposite side of the highway. A fundamental question in dispatching incident crews is whether to send the closest vehicle that is currently available or to wait for another vehicle to become available that is even closer. Waiting for a closer vehicle is advantageous because service time is effectively reduced, adding to capacity and providing stability at higher levels of utilization. But waiting for a vehicle to become available adds uncertainty, which contributes to expected traffic delay. As a consequence, any reasonably robust dispatch strategy must provide for a hybridization of the two objectives, trading-off greater certainty in response time against stability at higher utilization levels.
Michael-Simon inequalities for k-th mean curvatures

This paper continues the study of Alexandrov–Fenchel inequalities for quermassintegrals for \(k\)-convex domains. It focuses on the application to the Michael–Simon type inequalities for \(k\)-curvature operators. The proof uses optimal transport maps as a tool to relate curvature quantities defined on the boundary of a domain.
Serving content with unknown demand: the high-dimensional regime

In this paper, we look at content placement in the high-dimensional regime: there are $$n$$n servers, and $${\mathrm {O}}(n)$$O(n) distinct types of content. Each server can store and serve $${\mathrm {O}}(1)$$O(1) types at any given time. Demands for these content types arrive and have to be served in an online fashion; over time, there are a total of $${\mathrm {O}}(n)$$O(n) of these demands. We consider the algorithmic task of content placement: determining which types of content should be on which server at any given time, in the setting where the demand statistics (i.e., the relative popularity of each type of content) are not known a-priori, but have to be inferred from the very demands we are trying to satisfy. This is the high-dimensional regime because this scaling (everything being $${\mathrm {O}}(n)$$O(n)) prevents consistent estimation of demand statistics; it models many modern settings where large numbers of users, servers, and videos/webpages interact in this way. We characterize the performance of any scheme that separates learning and placement (i.e., which uses a portion of the demands to gain some estimate of the demand statistics, and then uses the same for the remaining demands), showing it is order-wise strictly suboptimal. We then study a simple adaptive scheme--which myopically attempts to store the most recently requested content on idle servers--and show it outperforms schemes that separate learning and placement. Our results also generalize to the setting where the demand statistics change with time. Overall, our results demonstrate that separating the estimation of demand, and the subsequent use of the same, is strictly suboptimal.
Structure and ion exchange properties of tunnel type titanium silicates

Abstract A large number of titanium silicates are known to exist in the mineral realm and recently a considerable literature has developed concerned with the synthesis and properties of these and related compounds. This paper describes two such families that have tunnel structures filled with cations that may easily be exchanged. A sodium titanosilicate of ideal formula, Na2Ti2O3(SiO4)2·2H2O, is tetragonal and built up of Ti4O4 cubane-like structures linked together by silicate groups in the a and b directions in the form of a square. In the c-axis direction, the cubane groups are linked by oxo-groups to form a framework enclosing tunnels parallel to the c-axis direction. The several ion exchange sites were identified based upon X-ray diffraction studies and the reason for the great affinity of this compound for Cs+ elucidated. The second family of compounds have the general composition M3H(TiO)4(SiO4)3·4H2O (M=alkali metal cation) and have the pharmacosiderite structure. The sodium or potassium phases are selective for Sr2+ and Cs+. These compounds are cubic and have similar Ti4O4 cubane-like groups. In this case, the connectivity via silicate groups extends along all three crystallographic axes equally. This change in crystal system has a profound effect upon the ion exchange behavior. This effect, as well as the effect of germanate substitutions for silicate, will be described.
Anomalous Arsenic Diffusion in Silicon Dioxide

The diffusion of ion‐implanted arsenic in thermally grown silicon dioxide is examined as a function of temperature, arsenic concentration, and ambient. Diffusion coefficients are calculated from profiles obtained by secondary ion mass spectroscopy (SIMS) analysis. At relatively low concentrations—below approximately —the activation energy of the diffusion coefficient in nitrogen atmosphere between 1000° and 1200°C is 4.7 eV. At high concentrations—above —it is found that arsenic practically does not diffuse under the above conditions. This phenomenon might be attributed to arsenic‐silicon‐oxygen complex formation. However, if annealed in a dry oxygen atmosphere, arsenic diffuses at both high and low concentrations with an activation energy of 3.7 eV. It is determined that it is necessary that oxidation of underlying silicon must be taking place for such an enhanced diffusion to occur. The mere presence of oxygen in the annealing ambient, without silicon oxidation, does not have any effect.
Casting light on BSM physics with SM standard candles

The Standard Model (SM) has had resounding success in describing almost every measurement performed by the ATLAS and CMS experiments. In particular, these experiments have put many beyond the SM models of natural Electroweak Symmetry Breaking into tension with the data. It is therefore remarkable that it is still the LEP experiment, and not the LHC, which often sets the gold standard for understanding the possibility of new color-neutral states at the electroweak (EW) scale. Recently, ATLAS and CMS have started to push beyond LEP in bounding heavy new EW states, but a gap between the exclusions of LEP and the LHC typically remains. In this paper we show that measurements of SM Standard Candles can be repurposed to set entirely complementary constraints on new physics. To demonstrate this, we use W + W −cross section measurements to set bounds on a set of slepton-based simplified models which fill in the gaps left by LEP and dedicated LHC searches. Having demonstrated the sensitivity of the W + W −measurement to light sleptons, we also find regions where sleptons can improve the fit of the data compared to the NLO SM W + W −prediction alone. Remarkably, in those regions the sleptons also provide for the right relic-density of Bino-like Dark Matter and provide an explanation for the longstanding 3σ discrepancy in the measurement of (g − 2)μ.
The chemistry of vicinal tricarbonyls a total synthesis of prodigiosin

Abstract The addition of primary amines to alkenyl vicinal tricarbonyls leads to 5-substituted-3-hydroxypyrroles. This reaction has been employed in a synthesis of the 2-formyl-3-methoxy-α,α′-bipyrrole precursor of the prodigiosin family of natural products.
GEOMETRY OF THE MODULI OF HIGHER SPIN CURVES

This article treats various aspects of the geometry of the moduli of r-spin curves and its compactification . Generalized spin curves, or r-spin curves, are a natural generalization of 2-spin curves (algebraic curves with a theta-characteristic), and have been of interest lately because of the similarities between the intersection theory of these moduli spaces and that of the moduli of stable maps. In particular, these spaces are the subject of a remarkable conjecture of E. Witten relating their intersection theory to the Gelfand–Dikii (KdVr) heirarchy. There is also a W-algebra conjecture for these spaces [16] generalizing the Virasoro conjecture of quantum cohomology. For any line bundle on the universal curve over the stack of stable curves, there is a smooth stack of triples (X, ℒ, b) of a smooth curve X, a line bundle ℒ on X, and an isomorphism . In the special case that is the relative dualizing sheaf, then is the stack of r-spin curves. We construct a smooth compactification of the stack , describe the geometric meaning of its points, and prove that its coarse moduli is projective. We also prove that when r is odd and g>1, the compactified stack of spin curves and its coarse moduli space are irreducible, and when r is even and is the disjoint union of two irreducible components. We give similar results for n-pointed spin curves, as required for Witten's conjecture, and also generalize to the n-pointed case the classical fact that when is the disjoint union of d(r) components, where d(r) is the number of positive divisors of r. These irreducibility properties are important in the study of the Picard group of [15], and also in the study of the cohomological field theory related to Witten's conjecture [16, 34].
Preparing for Ignition Experiments on the National Ignition Facility

Abstract The National Ignition Facility (NIF) is a 192 beam Nd-glass laser facility presently under construction at Lawrence Livermore National Laboratory (LLNL) for performing ignition experiments for inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. NIF will produce 1.8 MJ, 500 TW of ultraviolet light ( λ = 351 nm) making it the world's largest and most powerful laser system. NIF will be the world's preeminent facility for the study of matter at extreme temperatures and densities producing and for developing ICF. The ignition studies will an essential step in developing inertial fusion energy. The NIF Project is over 93% complete and scheduled for completion in 2009. Experiments using one beam have demonstrated that NIF can meet all of its performance goals. A detailed plan called the National Ignition Campaign (NIC) has been developed to begin ignition experiments in 2010. The plan includes the target physics and the equipment such as diagnostics, cryogenic target manipulator and user optics required for the ignition experiment. Target designs have been developed that calculate to ignite at energy as low as 1 MJ. Plans are underway to make NIF a national user facility for experiments on HED physics and nuclear science, including experiments relevant to the development of IFE.
The strong exponential hierarchy collapses

Abstract Composed of the levels E (i.e., ∪ c DTIME[2 cn ]), NE, P NE , NP NE , etc., the strong exponential hierarchy is an exponential-time analogue of the polynomial-time hierarchy. This paper shows that the strong exponential hierarchy collapses to P NE , its Δ 2 level. E ≠ p NE = NP NE ∪ NP NP NE ∪ … The proof stresses the use of partial census information and the exploitation of nondeterminism. Extending these techniques, we derive new quantitative relativization results: if the weak exponential hierarchy's Δ J + 1 and Σ j + 1 levels, respectively E Σ j p and NE Σ j p , do separate, this is due to the large number of queries NE makes to its Σ j p database. Our techniques provide a successful method of proving the collapse of certain complexity classes.
Atmospheric Cloud Physics Laboratory Thermal Control

The paper presents the development background and the present status of the Atmospheric Cloud Physics Laboratory (ACPL) thermal control capability. The ACPL, a Spacelab payload, is currently in the initial flight hardware development phase for a first flight scheduled in June 1981. The ACPL is intended as a facility for conducting a wide variety of cloud microphysics experimentation under zero gravity conditions. The cloud chambers, which are key elements of the ACPL, have stringent thermal requirements. Thus the expansion chamber inner walls must be uniform to within + or - 0.1 C during both steady-state and transient operation over a temperature range of +30 to -25 C. Design progression of the expansion chamber, from early in-house NASA-MSFC concepts (including test results of a prototype chamber) to a thermal control concept currently under development, is discussed.
Dynamic Template Tracking and Recognition

In this paper we address the problem of tracking non-rigid objects whose local appearance and motion changes as a function of time. This class of objects includes dynamic textures such as steam, fire, smoke, water, etc., as well as articulated objects such as humans performing various actions. We model the temporal evolution of the object’s appearance/motion using a linear dynamical system. We learn such models from sample videos and use them as dynamic templates for tracking objects in novel videos. We pose the problem of tracking a dynamic non-rigid object in the current frame as a maximum a-posteriori estimate of the location of the object and the latent state of the dynamical system, given the current image features and the best estimate of the state in the previous frame. The advantage of our approach is that we can specify a-priori the type of texture to be tracked in the scene by using previously trained models for the dynamics of these textures. Our framework naturally generalizes common tracking methods such as SSD and kernel-based tracking from static templates to dynamic templates. We test our algorithm on synthetic as well as real examples of dynamic textures and show that our simple dynamics-based trackers perform at par if not better than the state-of-the-art. Since our approach is general and applicable to any image feature, we also apply it to the problem of human action tracking and build action-specific optical flow trackers that perform better than the state-of-the-art when tracking a human performing a particular action. Finally, since our approach is generative, we can use a-priori trained trackers for different texture or action classes to simultaneously track and recognize the texture or action in the video.
Internet and Personal Computing Fads

Internet and Personal Computing Fads Mary Ann Bell, Mary Ann Berry, and James L. Van Roekel. New York: Haworth Press, 2004. This wide-ranging, -well-researched book attempts to give an overview of the world created by computers, and the obvious advantages and frightening problems that came with it. Their history can be traced back as early as 450 BC and the abacus. The first mechanical computer was developed by Wilhelm Schikard, a German, in the early seventeenth century. Britain's Charles Babbage invented his "analytical machine" and the card system in 1834; his assistant, Lady Lovelace, Lord Byron's daughter, wrote directions from which "programs" were developed. From the early history, women played a vital role in developing computer technology and our move into Cyberspace. The history of the Internet began when the Soviets launched Sputnik in 1957, and in 1972, Ray Tomlinson created the first e-mail program. The World Wide Web (WWW) was released to the world in 1992. Today we see people carrying and using pagers, cell phones, PDAs, laptops, CD players, and many new items. In his book What Will Be (1997), Michael Dertouzos described a world in which people will not wear conventional clothes but techno-bodysuits. The book is not divided into conventional chapters, but alphabetical topics, beginning with "Acceptable Use Policy" and concluding with "Y2K." Included are items that many never have heard of-or at least never used. Examples are Power Point Poisoning, Shareware, Spamming, Twain, URL, Usenet, Webcams, and Webquests. The goal is to include as much data as possible. Two of the three editors are assistant professors of library science, and the third (James Van Roekel) is the director of academic instruction technology and distance learning. All see this as a handbook that takes a practical look into the computer world. They employ short, jargon-free explanations of terms often used but not always understood. They want to show us how to deal with all of these culture benders. The editors make no value judgments, but some of us floating about (often lost) in the world of computers, Internet, e-mail, and indigestible spam think that we should and must take value judgments and ask, Where are we going? Do we want to be there? Will all of this enhance our lives? Is a little learning a dangerous thing, as Alexander Pope warned? New computer worries emerged in 2004 when the Silicon Valley Toxics Coalition issued a warning about e-waste. Now e-mail isn't alone as a problem. …
Radiation therapy in the last month of life.

Abstract Aim We sought to survey a large, multi-center patient sample to better characterize/quantify RT utilization at the end of life. Background Few objective data exist for radiation therapy (RT) delivery at end of life (EOL). Materials and methods Data were retrieved for all patients receiving RT in calendar year 2010 in the Department of Radiation Oncology at Indiana University (IU) and Howard University (HU) hospitals. Specific attention was made of the group of patients receiving RT in the last 30 days of life. Results A total of 852 patients received all or part of their RT during 2010 (HU: 139, IU: 713). At time of analysis in early 2012, 179 patients had died (21%). Fifty-four patients (6.3% of total; 30% of expired patients) died within 30 days of receiving their last treatment. Twenty patients (2.3% of total; 11.2% of expired patients) received RT within their last week of life. For both sites, the median time until death from completion of therapy was 12.5 days (range 2–30 days). Conclusions Radiation in the last month of life is likely to provide minimal palliation or survival benefit. This, coupled with the financial implications, time investment, and physical costs, suggests that physicians and patients should more strongly consider hospice, and minimize duration of palliative RT courses as far as possible. As with chemotherapy, RT utilization at EOL should be considered for collection as an overuse metric.
Developing a facility for magnetoaerodynamic experiments

Significant progress has been made in researching key components for a magnetoaerodynamic hypersonic experimental facility. A wind tunnel, which operates at a nominal Mach number of 6, has been restored to running condition and yielded preliminary data on aerodynamic drag and shock bifurcation for a jet spike. Plasma generation via radio-frequency (RF) radiation has also shown promise in providing a fairly uniform field around the RF-signal-carrying electrode. A technique for measuring temperature of weakly ionized air has been accomplished based on rotational spectra of vibrionic excitation of nitrogen. These newly acquired techniques are being integrated to create an interdisciplinary simulation facility
Quantum singularity of Levi-Civita spacetimes

Quantum singularities in general relativistic spacetimes are determined by the behaviour of quantum test particles. A static spacetime is quantum mechanically singular if the spatial portion of the wave operator is not essentially self-adjoint. Here Weyl's limit point–limit circle criterion is used to determine whether a wave operator is essentially self-adjoint. This test is then applied to scalar wave packets in Levi-Civita spacetimes to help elucidate the physical properties of the spacetimes in terms of their metric parameters.
Memory-based parsing

Robust text understanding systems can be developed by focusing on the application of memory-based parsing techniques. This paper describes an experiment in extending these techniques as far as possible. Described here are the parsing methods used by the Integrated Partial Parser (IPP), a computer system designed to read and generalize from large numbers of news stories. These methods include top-down, <
Nash equilibria equal competitive equilibria

Abstract With strictly monotone preferences and a continuum of traders, there is a game in which the set of Nash equilibria is exactly the same as the set of competitive equilibria.
Large-Scale Automatic Reconstruction of Neuronal Processes from Electron Microscopy Images

Abstract Automated sample preparation and electron microscopy enables acquisition of very large image data sets. These technical advances are of special importance to the field of neuroanatomy, as 3D reconstructions of neuronal processes at the nm scale can provide new insight into the fine grained structure of the brain. Segmentation of large-scale electron microscopy data is the main bottleneck in the analysis of these data sets. In this paper we present a pipeline that provides state-of-the art reconstruction performance while scaling to data sets in the GB-TB range. First, we train a random forest classifier on interactive sparse user annotations. The classifier output is combined with an anisotropic smoothing prior in a Conditional Random Field framework to generate multiple segmentation hypotheses per image. These segmentations are then combined into geometrically consistent 3D objects by segmentation fusion. We provide qualitative and quantitative evaluation of the automatic segmentation and demonstrate large-scale 3D reconstructions of neuronal processes from a 27 , 000 μ m 3 volume of brain tissue over a cube of 30 μ m in each dimension corresponding to 1000 consecutive image sections. We also introduce Mojo, a proofreading tool including semi-automated correction of merge errors based on sparse user scribbles.
The number of nowhere-zero flows on graphs and signed graphs

A nowhere-zero k-flow on a graph @C is a mapping from the edges of @C to the set {+/-1,+/-2,...,+/-(k-1)}@?Z such that, in any fixed orientation of @C, at each node the sum of the labels over the edges pointing towards the node equals the sum over the edges pointing away from the node. We show that the existence of an integral flow polynomial that counts nowhere-zero k-flows on a graph, due to Kochol, is a consequence of a general theory of inside-out polytopes. The same holds for flows on signed graphs. We develop these theories, as well as the related counting theory of nowhere-zero flows on a signed graph with values in an abelian group of odd order. Our results are of two kinds: polynomiality or quasipolynomiality of the flow counting functions, and reciprocity laws that interpret the evaluations of the flow polynomials at negative integers in terms of the combinatorics of the graph.
Why isn’t growth making us happier? Utility on the hedonic treadmill

Abstract A preference structure is constructed, grounded in psychological evidence, with well-being a function of the consumption level and the growth of the variety of goods consumed. Such preferences are analyzed in an endogenous variety growth model. The implications are consistent with the increase in income and the variety of goods consumed in developed economies in the post-war period that have not been accompanied by an increase in reported well-being. Moreover, the results suggest a connection between the stagnancy of reported well-being and diminishing returns in technological change, despite an increase in the variety of goods available over time.
Zero-dimensional organic-based magnets possessing decamethylmetallocene

Magnets composed of organic components that provide both spin and spin coupling to stabilize ferromagnetic ordering were first realized with the ionic, electron transfer salt [Fe(C5Me5)2]+[TCNE]˙− (TCNE = tetracyanoethylene), which orders at 4.8 K (Tc). After more than two decades of study, its structure, as well as the magnetic behaviour and structures of its solvates, have been recently established. All structurally characterized members of this family of organic-based magnets have the same structural motif of parallel chains of alternating radical [M(C5Me5)2]+ cations and planar radical organic anions with intrachain M⋯M separations of 10.7 ± 0.3 A, and lack any sub van der Waals interactions. In this Feature article the chemical and magnetic properties of the growing family of [M(C5Me5)2][acceptor] (M = Cr, Mn, Fe) materials is described with emphasis on the recent developments, common trends, and outstanding problems and opportunities.
Neutron activation analysis for assessing the concentrations of trace elements in laboratory detergents

Abstract Nondestructive instrumental neutron activation analysis was used to assess the concentration of 20 elements in the following laboratory detergents: Micro, Cavi-Clean liquid, RBS-35, Liqui-Nox, Treg-A-Zyme, Alcojet, Alconox, Alcotabs and Radiacwash; and a detergent additive: Cavi-Clean additive. The upper detected limits or the concentration ranges for the detergents are (element concentration in μg/g): Ba,
A complete mapping of the density matrix of a qubit in a single quantum dot

The off-diagonal density matrix elements of a single qubit system in a single quantum dot can be obtained by an optical pi/2 rotation, leading to a complete mapping of the complex density matrix
Synthesis and analysis of oligonucleotides containing abasic site analogues.

DNA damage results in the formation of abasic sites from the formal hydrolysis of the glycosidic bond (AP) and several oxidized abasic lesions. Previous studies on AP sites revealed that DNA polyme...
A study of the data commutation problems in a self-repairable multiprocessor

In recent years significant effort has been devoted to the development of techniques for realizing computer systems for which a significant problem of design arises from the unreliability of components and assembly as well as from special constraints on construction and operation. Examples of such systems are computers for aerospace missions and on-line process control.
Curvature and torsion of material lines in chaotic flows

The deformation of a material line as it evolves in a chaotic flow is considered. Of particular interest are the curvature and torsion as a function of arclength or material coordinate along the line and their near singular behavior that develops as the deformation proceeds. Recent work [Thiffeault 2004. Physica D 198, 169–181] has established an interesting connection between local line stretch and curvature for regions of high curvature. The present effort confirms this connection and develops a similar relation between torsion and curvature for regions of high absolute torsion. In addition it is shown that certain properties of the strain tensor play a key role in the location and structure of the near singular behavior in curvature.
An improved method for the assay of platelet pyruvate dehydrogenase

An improved method for the assay of human platelet pyruvate dehydrogenase is described. By generating the substrate [1-14C]pyruvate in situ from [1-14C]lactate plus l-lactate dehydrogenase, the rate of spontaneous decarboxylation is dramatically reduced, allowing far greater sensitivity in the assay of low activities of pyruvate dehydrogenase. In addition, no special precautions are required for the storage and use of [1-14C]lactate, in contrast to those for [1-14C] pyruvate. These factors allow a 5–10-fold increase in sensitivity compared with current methods. The pyruvate dehydrogenase activity of normal subjects as determined by the [1-14C]lactate system was 215 ± 55 pmol · min−1 · mg−1 protein (n = 18). The advantages of this assay system are discussed.
Exponential iterated integrals and the relative solvable completion of the fundamental group of a manifold

We develop a class of integrals on a manifold M called exponential iterated integrals, an extension of K.T. Chen's iterated integrals. It is shown that the matrix entries of any upper triangular representation of π1(M,x) can be expressed via these new integrals. The ring of exponential iterated integrals contains the coordinate rings for a class of universal representations, called the relative solvable completions of π1(M,x). We consider exponential iterated integrals in the particular case of fibered knot complements, where the fundamental group always has a faithful relative solvable completion.
A Bmp/Admp Regulatory Circuit Controls Maintenance and Regeneration of Dorsal-Ventral Polarity in Planarians

Animal embryos have diverse anatomy and vary greatly in size. It is therefore remarkable that a common signaling pathway, BMP signaling, controls development of the dorsoventral (DV) axis throughout the Bilateria. In vertebrates, spatially opposed expression of the BMP family proteins Bmp4 and Admp (antidorsalizing morphogenetic protein) can promote restoration of DV pattern following tissue removal. bmp4 orthologs have been identified in all three groups of the Bilateria (deuterostomes, ecdysozoans, and lophotrochozoans). By contrast, the absence of admp orthologs in ecdysozoans such as Drosophila and C. elegans has suggested that a regulatory circuit of oppositely expressed bmp4 and admp genes represents a deuterostome-specific innovation. Here we describe the existence of spatially opposed bmp and admp expression in a protostome. An admp ortholog (Smed-admp) is expressed ventrally and laterally in adult Schmidtea mediterranea planarians, opposing the dorsal-pole expression of Smed-bmp4. Smed-admp is required for regeneration following parasagittal amputation. Furthermore, Smed-admp promotes Smed-bmp4 expression and Smed-bmp4 inhibits Smed-admp expression, generating a regulatory circuit that buffers against perturbations of Bmp signaling. These results suggest that a Bmp/Admp regulatory circuit is a central feature of the Bilateria, used broadly for the establishment, maintenance, and regeneration of the DV axis.
The Discovery of an Active Galactic Nucleus in the Late-Type Galaxy NGC 3621: Spitzer Spectroscopic Observations

We report the discovery of an active galactic nucleus (AGN) in the nearby SAd galaxy NGC 3621 using Spitzer high spectral resolution observations. These observations reveal the presence of [Ne V] 14 and 24 ?m emission that is centrally concentrated and peaks at the position of the near-infrared nucleus. Using the [Ne V] line luminosity, we estimate that the nuclear bolometric luminosity of the AGN is ~5 ? 1041 ergs s-1, which, based on the Eddington limit, corresponds to a lower mass limit of the black hole of ~4 ? 103 M?. Using an order-of-magnitude estimate for the bulge mass based on the Hubble type of the galaxy, we find that this lower mass limit does not put a strain on the well-known relationship between the black hole mass and the host galaxy's stellar velocity dispersion established in predominantly early-type galaxies. Multiwavelength follow-up observations of NGC 3621 are required to obtain more precise estimates of the bulge mass, black hole mass, accretion rate, and nuclear bolometric luminosity. The discovery reported here adds to the growing evidence that a black hole can form and grow in a galaxy with no or minimal bulge.
Application of Dispersion Relations to Meson-Nucleon Scattering

Relativistic nonforward scattering dispersion relations are used to obtain information about low-energy meson-nucleon scattering. It is determined which of the $s$-, $p$-, and $d$-wave phase shifts are predicted by dispersion theory. Charge independence is assumed. The form of the dispersion relations used is justified by relating the asymptotic energy dependence of the dispersion relation amplitudes to the assumption of a finite range of interaction and to the choice of a particular meson current and the usual equal time commutation relations. The relevence of the analytic properties of the scattering amplitude as a function of momentum transfer is discussed in connection with the partial wave expansion of the dispersion amplitudes. The contribution to the dispersion integrals from energies above the 33 resonance is estimated.
A Syntactic Approach to Foundational Proof-Carrying Code

Proof-carrying code (PCC) is a general framework for verifying the safety properties of machine-language programs. PCC proofs are usually written in a logic extended with language-specific typing rules; they certify safety but only if there is no bug in the typing rules. In foundational proof-carrying code (FPCC), on the other hand, proofs are constructed and verified by using strictly the foundations of mathematical logic, with no type-specific axioms. FPCC is more flexible and secure because it is not tied to any particular type system and it has a smaller trusted base. Foundational proofs, however, are much harder to construct. Previous efforts on FPCC all required building sophisticated semantic models for types. Furthermore, none of them can be easily extended to support mutable fields and recursive types. In this article, we present a syntactic approach to FPCC that avoids all of these difficulties. Under our new scheme, the foundational proof for a typed machine program simply consists of the typing derivation plus the formalized syntactic soundness proof for the underlying type system. The former can be readily obtained from a type-checker, while the latter is known to be much easier to construct than the semantic soundness proofs. We give a translation from a typed assembly language into FPCC and demonstrate the advantages of our new system through an implementation in the Coq proof assistant.
Phase transitions in M-theory and F-theory

Abstract Phase transitions are studied in M -theory and F -theory. In M -theory compactification to five dimensions on a Calabi-Yau, one can find topology-changing transitions similar to those seen in conformal field theory, but the non-geometrical phases known in conformal field theory are absent. At boundaries of moduli space where such phases might have been expected, the moduli space ends, by a conventional or unconventional physical mechanism. The unconventional mechanisms, which roughly involve the appearance of tensionless strings, can sometimes be better understood in F -theory.
The nitrosation of imidazolines and oxazolines

Abstract Nitrosation ( HOAc NaNO 2 ) of 1-methyl-2-phenyl-2-imidazoline 8 results in cleavage of only the CN single bond and production of N-(2-methylnitrosaminoethyl)-N-nitrosobenzamide 10. In contrast, 2-phenyl-2-oxazoline 9 nitrosates very rapidly to give products (13–16) derived from a diazonium ion arsing from the exclusive cleavage of the CN.
Optical and X-Ray Observations of GRB 060526: A Complex Afterglow Consistent with an Achromatic Jet Break

We obtained 98 R-band and 18 B, r', i' images of the optical afterglow of GRB 060526 (z = 3.21) with the MDM 1.3 m, 2.4 m, and the PROMPT telescopes at CTIO over the five nights following the burst trigger. Combining these data with other optical observations reported in GCN and the Swift XRT observations, we compare the optical and X-ray afterglow light curves of GRB 060526. Both the optical and X-ray afterglow light curves show rich features, such as flares and breaks. The densely sampled optical observations provide very good coverage at T > 10(exp 4) s. We observed a break at 2.4 x 10(exp 5) sin the optical afterglow light curve. Compared with the X-ray afterglow light curve, the break is consistent with an achromatic break supporting the beaming models of GRBs. However, the prebreak and postbreak temporal decay slopes are difficult to explain in simple afterglow models. We estimated a jet angle of theta(sub j) approx. 7deg and a prompt emission size of R(sub prompt) approx. 2 x 10(exp 14) cm. In addition, we detected several optical flares with amplitudes of (Delta)m approx. 0.2,0.6, and 0.2 mag. The X-ray afterglows detected by Swift have shown complicated decay patterns. Recently, many well-sampled optical afterglows also show decays with flares and multiple breaks. GRB 060526 provides an additional case of such a complex, well-observed optical afterglow. The accumulated well-sampled afterglows indicate that most of the optical afterglows are complex.
Kaon condensation in neutron star matter with hyperons

Abstract Based on the Kaplan-Nelson Lagrangian, we investigate kaon condensation in dense neutron star matter allowing for the explicit presence of hyperons. Using various models we find that the condensate threshold is sensitive to the behavior of the scalar density; the more rapidly it increases with baryon density, the lower is the threshold for condensation. The presence of hyperons, particularly the Σ − , shifts the threshold for K − condensation to a higher density. In the mean field approach, with hyperons, the condensate amplitude grows sufficiently rapidly that the nucleon effective mass vanishes at a finite density and a satisfactory treatment of the thermodynamics cannot be achieved. Thus, calculations of kaon-baryon interactions beyond the mean field level appear to be necessary.
Poisson-Lie group of pseudodifferential symbols

We introduce a Lie bialgebra structure on the central extension of the Lie algebra of differential operators (with scalar or matrix coefficients) on the line and on the circle. This defines a Poisson-Lie structure on the dual group of pseudodifferential symbols of an arbitrary real (or complex) order. We show that the usual (second) Benney, GL n -KdV (or GL n -Adler-Gelfand-Dickey) and KP Poisson structures are naturally realized as restrictions of this Poisson structure to submanifolds of this “universal” Poisson-Lie group. Moreover, the reduced (=SL n ) versions of these manifolds (orW n -algebras in physical terminology) can be viewed as certain subspaces of the quotient of this Poisson-Lie group by the dressing action of the group of functions on the circle (or as a result of a Poisson reduction). Finally we define an infinite set of commuting functions on the Poisson-Lie group that give the standard families of Hamiltonians when restricted to the submanifolds mentioned above. The Poisson structure and Hamiltonians on the whole group interpolate between the Poisson structures and Hamiltonians of Benney, KP and KdV flows. We also discuss the geometrical meaning ofW ∞ as a limit of Poisson algebrasW e as e→0.
Computer loss experience and predictions

The types of losses organizations must anticipate have become more difficult to predict because of the eclectic nature of computers and the data communications and the decrease in news media reporting of computer-related losses as they become commonplace. Total business crime is conjectured to be decreasing in frequency and increasing in loss per case as a result of increasing computer use. Computer crimes are probably increasing, however, as their share of the decreasing business crime rate grows. Ultimately all business crime will involve computers in some way, and we could see a decline of both together. The important information security measures in high-loss business crime generally concern controls over authorized people engaged in unauthorized activities. Such controls include authentication of users, analysis of detailed audit records, unannounced audits, segregation of development and production systems and duties, shielding the viewing of screens, and security awareness and motivation controls in high-value transaction areas. Computer crimes that involve highly publicized intriguing computer misuse methods, such as privacy violations, radio frequency emanations eavesdropping, and computer viruses, have been reported in waves that periodically have saturated the news media during the past 20 years. We must be able to anticipate such highly publicized crimes and reduce the impact and embarrassment they cause. On the basis of our most recent experience, I propose nine new types of computer crime to be aware of: computer larceny (theft and burglary of small computers), automated hacking (use of computer programs to intrude), electronic data interchange fraud (business transaction fraud), Trojan bomb extortion and sabotage (code security inserted into others' systems that can be triggered to cause damage), LANarchy (unknown equipment in use), desktop forgery (computerized forgery and counterfeiting of documents), information anarchy (indiscriminate use of crypto without control), Internet abuse (antisocial use of data communications), and international industrial espionage (governments stealing business secrets). A wide variety of safeguards are necessary to deal with these new crimes. The most powerful controls include (1) carefully controlled use of cryptography and digital signatures with good key management and overriding business and government decryption capability and (2) use of tokens such as smart cards to increase the strength of secret passwords for authentication of computer users. Jewelry-type security for small computers--including registration of serial numbers and security inventorying of equipment, software, and connectivity--will be necessary. Other safeguards include automatic monitoring of computer use and detection of unusual activities, segmentation and filtering of networks, special paper and ink for documents, and reduction of paper documents. Finally, international cooperation of governments to create trusted environments for business is essential.
Spatially adaptive local feature-driven total variation minimizing image restoration

Total variation (TV) minimizing image restoration is a fairly new approach to image restoration, and has been shown both analytically and empirically to be quite effective. Our primary concern here is to develop a spatially adaptive TV minimizing restoration scheme. One way of accomplishing this is to locally weight the measure or computation of the total variation of the image. The weighting factor is chosen to be inversely proportional to the likelihood of the presence of an edge at each discrete location. This allows for less regularization where edges are present and more regularization where there are no edges, which results in a spatially varying balance between noise removal and detail preservation, leading to better overall image restoration. In this paper, the likelihood of edge presence if determined from a partially restored image. The results are best for images with piecewise constant image features.
Identification of a series of PPARγ/δ dual agonists via solid-phase parallel synthesis

We have developed a general solid-phase synthesis for identification of PPAR ligands. Synthesis of a 480-member library led to the identification of a potent PPAR gamma/delta dual agonist 23. Compound 23 showed good plasma exposure in rats and demonstrated antihyperglycemic and antihyperlipidemic efficacy in diabetic fatty Zucker rats.
Systems analysis of a low-acceleration research facility

The Low-Acceleration Research Facility (LARF), an unmanned free-flier that is boosted from low-earth orbit to a desired altitude using an orbital transfer vehicle is discussed. Design techniques used to minimize acceleration-causing disturbances and to create an ultra-quiet workshop are discussed, focusing on residual acceleration induced by the environment, the spacecraft and experiments. The selection and integration of critical subsystems, such as electrical power and thermal control, that enable the LARf to accomodate sub-microgravity levels for extended periods of time are presented, including a discussion of the Low-Acceleration Module, which will supply the payload with 25.0 kW of power, and up to 11.8 kW in the low-power mode. Also, the data management, communications, guidance, navigation and control, and structural features of supporting subsystems are examined.