cssi/SciSciGPT-SciSciNet huggingface dataset:
PARAMETER CONSTRAINTS FOR HIGH-ENERGY MODELS OF COLLIDING WINDS OF MASSIVE STARS: THE CASE WR 147

We explore the ability of high-energy observations to constrain orbital parameters of long-period massive binary systems by means of an inverse Compton (IC) model acting in colliding wind environments. This is particularly relevant for (very) long-period binaries where orbital parameters are often poorly known from conventional methods, as is the case, e.g. for the Wolf-Rayet (W-R) star binary system WR 147, where INTEGRAL and MAGIC upper limits on the high-energy emission have recently been presented. We conduct a parameter study of the set of free quantities describing the yet vaguely constrained geometry and respective effects on the nonthermal high-energy radiation from WR 147. The results are confronted with the recently obtained high-energy observations and with sensitivities of contemporaneous high-energy instruments like Fermi-LAT. For binaries with sufficient long periods, like WR 147, γ-ray attenuation is unlikely to cause any distinctive features in the high-energy spectrum. This leaves the anisotropic IC scattering as the only process that reacts sensitively on the line-of-sight angle with respect to the orbital plane, and therefore allows the deduction of system parameters even from observations not covering a substantial part of the orbit. Provided that particle acceleration acts sufficiently effectively to allow the production of GeV photons through IC scattering, our analysis indicates a preference for WR 147 to possess a large inclination angle. Otherwise, for low inclination angles, electron acceleration is constrained to be less efficient as anticipated here.
Fundamentals of Large Sensor Networks: Connectivity, Capacity, Clocks, and Computation

Sensor networks potentially feature large numbers of nodes. The nodes can monitor and sense their environment over time, communicate with each other over a wireless network, and process information that they exchange with each other. They differ from data networks in that the network as a whole may be designed for a specific application. We study the theoretical foundations of such large-scale sensor networks. We address four fundamental organizational and operational issues related to large sensor networks: connectivity, capacity, clocks, and function computation. To begin with, a sensor network must be connected so that information can indeed be exchanged between nodes. The connectivity graph of an ad hoc network is modeled as a random graph and the critical range for asymptotic connectivity is determined, as well as the critical number of neighbors that a node needs to connect to. Next, given connectivity, we address the issue of how much data can be transported over the sensor network. We present fundamental bounds on capacity under several models, as well as architectural implications for how wireless communication should be organized. Temporal information is important both for the applications of sensor networks as well as their operation. We present fundamental bounds on the synchronizability of clocks in networks, and also present and analyze algorithms for clock synchronization. Finally, we turn to the issue of gathering relevant information, which sensor networks are designed to do. One needs to study optimal strategies for in-network aggregation of data, in order to reliably compute a composite function of sensor measurements, as well as the complexity of doing so. We address the issue of how such computation can be performed efficiently in a sensor network and the algorithms for doing so, for some classes of functions.
Finite element solution for the structural behavior of a scientific balloon

A finite element solution for the structural behavior of a scientific balloon has been obtained using a non-linear finite element code. The pneumatic skin is modelled by shell elements that are given a small artificial bending stiffness to overcome numerical problems yet the membrane solution remains unaffected. Validation of the analysis approach is provided through strain measurements on a small scale balloon that exhibits all essential features of a full scale balloon.
A three-objective social welfare function for cost–benefit analysis

This article presents a set of policy decisions where a three-objective social welfare function (SWF) was used. In addition to efficiency and distributional elements there is a third constituent: t...
Oxidation of hydrocarbons catalyzed by manganese carboxylate complexes

Abstract High-valent manganese carboxylates catalyze the hydroxylation of alkanes and epoxidation of cyclooctene under mild conditions. Up to 21 turnovers of alkane oxidation in 3 hours are observed.
A parallel finite volume algorithm for large-eddy simulation of turbulent flows

Abstract A parallel, finite-volume algorithm has been developed for large-eddy simulation (LES) of compressible turbulent flows. This algorithm includes piecewise linear least-square reconstruction, trilinear finite-element interpolation, Roe flux-difference splitting (FDS), and second-order MacCormack time marching. A systematic and consistent means of evaluating the surface and volume integrals of the control volume is described. Parallel implementation is done using the message-passing programming model. To validate the numerical method for turbulence simulation, LES of fully developed turbulent flow in a square duct is performed for a Reynolds number of 320 based on the average friction velocity and the hydraulic diameter of the duct. Direct numerical simulation (DNS) results are available for this test case, and the accuracy of this algorithm for turbulence simulations can be ascertained by comparing the LES solutions with the DNS results. For the first time, a finite volume method with Roe FDS was used for LES of turbulent flow in a square duct, and the effects of grid resolution, upwind numerical dissipation, and subgrid-scale dissipation on the accuracy of the LES are examined. Comparison with DNS results shows that the standard Roe FDS adversely affects the accuracy of the turbulence simulation. For accurate turbulence simulations, only 3–5% of the standard Roe FDS dissipation is needed.
Misbehavioral urban economics

Applications of the framework of behavioral economics to questions arising from urban economics are discussed. Directions for future research are outlined.
Distributed averaging in the presence of a sparse cut

We consider the question of averaging on a graph that has one sparse cut separating two subgraphs that are internally well connected. We exhibit a decentralized algorithm for such graphs that uses updates involving negative weights and has an averaging time that can be significantly shorter than the averaging time of known distributed averaging algorithms.
Diagnosis of Placental Abruption: Relationship between Clinical and Histopathological Findings

Objective We evaluated the extent to which histologic lesions bearing a diagnosis of abruption conform to a diagnosis based on established clinical criteria. We further examined the profile of chronic and acute histologic lesions associated with clinical abruption.
Absolute reference calorimeter for measuring high power laser pulses

A calorimeter for making absolute energy measurements of high power laser pulses is described. The calorimeter, based on volume absorption in a solid, is calibrated electrically and requires no window or vacuum environment. An error analysis is included giving the systematic and random errors of the instrument for a laser measurement. Briefly, the following performance is typical of the 32-mm x 32-mm aperture calorimeter: range 0.4-15-J; random error +/-0.2% (one standard deviation); systematic error +/-2.3%; and an upper operational limit of 3 J/cm(2). Most of the volume absorber documentation is applicable for 1.06 microm; however, the calorimeter should be useful from the near ir through the visible. Absorbers for use with CO(2) lasers in the 9-11-microm range are also discussed.
A duplex theory of pitch perception

In the theories of pitch perception now widely supported, pitch is regarded as a unitary attribute of auditory experience. There is good evidence, however, that there are actually two pitch‐like attributes, and it is reasonable to suppose that the duplexity of pitch is a reflection of duplexity in the auditory process. The first step in the process is analysis in frequency, performed by the cochlea, which distributes stimulus components of various frequencies to spatially separated channels. The second step, according to the scheme postulated here, is autocorrelational analysis, performed by the neural part of the auditory system, of the signal in each frequency channel. The basic operations of autocorrelational analysis are delay, multiplication, and integration. The nervous system is nicely set up to perform these operations. A chain of neurons makes an excellent delay line. The spatial aspect of synaptic summation provides something very close to multiplication. And the temporal aspect of synaptic summation is essentially running integration. The duplex theory suggests, therefore, that neural circuits following the autocorrelation model supplement the cochlear frequency analysis. The postulated neural autocorrelator of course does not compute autocorrelation functions of the acoustic stimulus: it operates upon afferent neural signals. Because the markedly non‐linear process of neural excitation intervenes between the stimulus and the autocorrelation, the latter gives rise in certain instances to pitches that are not readily explained if the relatively linear cochlear analysis is considered to be the only one. “The case of the missing fundamental” and Schouten's residue effect, for example, are readily accounted for by the duplex theory. In addition, the theory provides a rational basis for the octave relation and for the consonance of other simple harmonic relations.
Enforcing safety of cyberphysical systems using flatness and abstraction

The diffusion of cyberphysical systems acting in human-populated environments brings to the fore the problem of implementing provably safe control laws, to avoid potentially dangerous collisions between moving parts of the system, and with nearby obstacles, without compromising the system's functionality. The limiting factor in most implementations is the model's complexity, and a common workaround includes the reduction of the physical model, based on differential equations, to a finite symbolic model. Following this strategy, we are investigating ways to exploit the specific structure of many mechanical systems (the differentially flat systems) to achieve this simplification. Our objective is to construct a supervisor enforcing a given set of safety rules, while imposing as little constraints as possible on the system's functionality. In this paper, we outline our approach, and present an example -- a collision avoidance algorithm for a fleet of vehicles converging to an intersection. Our approach improves on previous results by providing a deterministic symbolic model for a class of system, regardless of their stability properties, and by addressing explicitly the problem of safety enforcing.
Specialists, Limit‐Order Traders, and the Components of the Bid‐Ask Spread

This study compares the components of the bid-ask spread estimated from quotes that reflect the trading interest of specialists with those estimated from limit-order quotes and all available quotes for a sample of New York Stock Exchange (NYSE) stocks. The results show that the adverse selection component of the spread estimated from specialist quotes is significantly smaller than the corresponding figures from limit-order quotes and entire quotes. We interpret this as evidence that NYSE specialists transfer at least a part of adverse selection costs to outsiders through the discretionary use of limit orders. Our results show that the estimation/interpretation of the components of the spread using quote data that include both specialist and limit-order interests is problematic.
Clinical and pathologic correlates of stillbirths in a single institution.

BACKGROUND To evaluate risk factors, placental and pathologic determinants of stillbirths. METHODS A retrospective analysis of stillbirths > or = 25 weeks was performed. Clinical data was compared to a randomized control group. Statistical analysis included chi square test, student t test, and logistic regression. RESULTS One hundred and fifteen stillbirths and 193 controls were analyzed. Maternal age, nulliparity, tobacco use, previous induced abortions, anticardiolipid antibodies, elevated maternal serum alpha feto protein, twins, and amniocentesis, were significantly associated with stillbirth. Logistic regression analysis showed only maternal age, tobacco use, small for gestational age (SGA), previous induced abortions, decreasing gestational age as independent significant variables. The stillbirth baby was 6.8 times more likely to be SGA and 11.9 times more likely to be preterm. Primary pathologic diagnoses were placental factors (37%), cord complications (28%), and fetal causes (15%), 17% had maternal risk factors only and 3% had no known risk factors. Diagnosis was suggested by pathology in 40% of cases. CONCLUSIONS Stillbirth delivery is associated with older, nulliparous patients with prenatal complications resulting in intrauterine growth retardation and prematurity. Perinatal histopathologic examination is important in diagnosis. Utilizing an extensive testing protocol will reduce the diagnosis of unexplained stillbirth.
Synthesizing switching logic using constraint solving

For a system that can operate in multiple different modes, we define the switching logic synthesis problem as follows: given a description of the dynamics in each mode of the system, find the conditions for switching between the modes so that the resulting system satisfies some desired properties. In this paper, we present an approach for solving the switching logic synthesis problem in the case when (1) the dynamics in each mode of the system are given using differential equations and, hence, the synthesized system is a hybrid system, and (2) the desired property is a safety property. Our approach for solving the switching logic synthesis problem, called the constraint-based approach, consists of two steps. In the first constraint generation step, the synthesis problem is reduced to satisfiability of a quantified formula over the theory of reals. In the second constraint solving step, the quantified formula is solved. This paper focuses on constraint generation. The constraint generation step is based on the concept of a controlled inductive invariant. The search for controlled inductive invariant is cast as a constraint solving problem. The controlled inductive invariant is then used to arrive at the maximally liberal switching logic. We prove that the synthesized switching logic always gives us a well-formed and safe hybrid system. When the system, the safety property, and the controlled inductive invariant are all expressed only using polynomials, the generated constraint is an $${\exists\forall}$$ formula in the theory of reals, whose satisfiability is decidable.
The nanometer age: Challenge and chance

The new players in the emerging nano-world are individual, selected objects of the size of some 50 nm down to molecules and atoms. The new aspect of science and technology on the nanometer scale is that these objects are treated as individuals, not as ensemble members. To a great extent, this requires real-space methods. Local probe methods, such as scanning tunneling microscopy and its derivates, are therefore a key to the nano-world. Major challenges of the new nanometer world are to exploit the new possibilities that arise from nanometer dimensions, to interface the macroscopic world to nano-individuals, to establish new concepts for working with very large numbers of nano-individuals and large sets of control parameters, to create the basis for broad interdisciplinarity, and to prepare society for the tremendous changes anticipated in a nanometer world.
HEAT KERNEL ANALYSIS ON SEMI-INFINITE LIE GROUPS

This paper studies Brownian motion and heat kernel measure on a class of infinite dimensional Lie groups. We prove a Cameron–Martin type quasi-invariance theorem for the heat kernel measure and give estimates on the Lp norms of the Radon–Nikodym derivatives. We also prove that a logarithmic Sobolev inequality holds in this setting.
Evaluation of hazard and integrity monitor functions for integrated alerting and notification using a sensor simulation framework

ABSTRACT This paper discusses the results of an initial evaluation study of hazard and integrity monitor functions for use with integrated alerting and notification. The Hazard and Integrity Monitor (HIM) (i) allocates in formation sources within the Integrated Intelligent Flight Deck (IIFD) to required functionality (like conflict detection and avoidance) and determines required performance of these information sources as part of that function; (ii) monitors or evaluates the required performance of the individual information sources and performs consistency checks among various information sources; (iii) integrates the information to establish tracks of potential hazards that can be used for the conflict probes or conflictprediction for various time horizons including the 10, 5, 3, and <3 minutes used in our scenario; (iv) detects and assesses the class of the hazard and provide possible resolutions. The HIM monitors the operation-dependent performance parameters related to the potential hazards in a manner similar to the Required Navigation Performance (RNP). Various HIM concepts have been implemented and evaluated using a previously developed sensor simulator/synthesizer. Within the simulation framework, various inputs to the IIFD and its subsystems are simulated, synthesized from actual collected data, or played back from actual flight test sensor data. The framework and HIM functions are implemented in Simulink®, a modeling language developed by The Mathworks. This modeling language allows for test and evaluation of various sensor and communication link configurations as well as the inclusion of feedback from the pilot on the performance of the aircraft. Keywords: Hazard and Integrity Monitor, Hazard Tracking, Simulink, Integrated Intelligent Flight Deck
The lower dimensional Busemann-Petty problem in the complex hyperbolic space

The lower dimensional Busemann-Petty problem asks whether origin-symmetric convex bodies in R^n with smaller volume of all k-dimensional sections necessarily have smaller volume. The answer is negative for k>3. The problem is still open for k=2,3. We study this problem in the complex hyperbolic n-space H"C^n and prove that the answer is affirmative only for sections of complex dimension one and negative for sections of higher dimensions.
What is the Best Solution to Improve Thermal Performance of Storage Tanks With Immersed Heat Exchangers: Baffles or a Divided Tank?

Prior studies of indirect water storage tanks that employ an immersed heat exchanger to discharge the stored energy identified two potential methods of improving the rate of energy extraction: (1) an internal baffle to increase the velocity across the heat exchanger and (2) a divided storage compartment to achieve thermal stratification. The relative benefits of the two options are compared and recommendations for implementation are provided based in part on measurements in a 350 l tank with a 10 m long, 0.3 m 2 coiled tubular heat exchanger.
Model-Based Adaptive Behavior Framework for Optimal Acoustic Communication and Sensing by Marine Robots

In this paper, a hybrid data- and model-based autonomous environmental adaptation framework is presented which allows autonomous underwater vehicles (AUVs) with acoustic sensors to follow a path which optimizes their ability to maintain connectivity with an acoustic contact for optimal sensing or communication. The adaptation framework is implemented within the behavior-based mission-oriented operating suite-interval programming (MOOS-IvP) marine autonomy architecture and uses a new embedded high-fidelity acoustic modeling infrastructure, the generic robotic acoustic model (GRAM), to provide real-time estimates of the acoustic environment under changing environmental and situational scenarios. A set of behaviors that combine adaptation to the current acoustic environment with strategies that extend the decision horizon beyond that of typical behavior-based systems have been developed, implemented, and demonstrated in a series of field experiments and virtual experiments in a MOOS-IvP simulation.
Development of an N-sulfinyl prolinamide for the asymmetric aldol reaction

Abstract A new class of organocatalysts is reported that incorporates an N-sulfinyl amide in place of the carboxylic acid of proline to serve as a hydrogen bond donor, chiral directing group, and solubilizing element. The successful application of this type of catalyst to the asymmetric aldol reaction of acetone and aryl aldehydes, for which proline performs poorly, is also described.
The unique mechanistic transformations involved in the biosynthesis of modular natural products from marine cyanobacteria

Cyanobacteria are abundant producers of natural products well recognized for their bioactivity and utility in drug discovery and biotechnology applications. In the last decade, characterization of several modular gene clusters that code for the biosynthesis of these compounds has revealed a number of unusual enzymatic reactions. In this article, we review several mechanistic transformations identified in marine cyanobacterial biosynthetic pathways, with an emphasis on modular polyketide synthase(PKS)/non-ribosomal peptide synthetase (NRPS) gene clusters. In selected instances, we also make comparisons between cyanobacterial gene clusters derived from marine and freshwater strains. We then provide an overview of recent developments in cyanobacterial natural products biosynthesis made available through genome sequencing and new advances in bioinformatics and genetics.
Modeling and in vitro and in vivo characterization of a tissue engineered pancreatic substitute

In designing appropriate devices for the development of a functional pancreatic substitute, computational models capable of accurately predicting cellular behavior constitute a critical aspect. This study investigated the model-based design, fabrication and in vitro and in vivo experimental characterization of a pancreatic substitute consisting of mouse insulinoma cells encapsulated in agarose in a disk-shaped construct. Two construct prototypes were examined: (i) a single disk construct comprised of agarose and βTC3 cells; and (ii) a buffered disk construct, consisting of agarose and βTC3 cells, coated with an additional layer of pure agarose. Diffusional studies of glucose and insulin were performed to characterize the transport properties of the material. Three dimensional oxygen diffusion-reaction models were used to predict the appropriate cell loadings for the two construct prototypes under varying external oxygen tensions. In vitro and in vivo experiments found the overall viable cell number for each construct prototype plateaued to the same value, regardless of the initial cell seeding number, when constructs were placed under identical environmental conditions. Furthermore, mathematical model calculations correlated well with experimental in vitro and in vivo results of cell viability, indicating oxygen tension to be the dominating factor in establishing total viable cell number in these constructs. These results indicate that the development of a computational model capable of accurately predicting overall cell viability is useful for the development of tissue engineered constructs, when permissive matrices and continuous cell lines are used. The applicability of this modeling and experimental methodology in the development of agarose-based constructs for use as a bioartificial pancreas is discussed.
Odor coding by a mammalian receptor repertoire

Deciphering olfactory encoding requires a thorough description of the ligands that activate each odorant receptor (OR). In mammalian systems, however, ligands are known for fewer than 50 of more than 1400 human and mouse ORs, greatly limiting our understanding of olfactory coding. We performed high-throughput screening of 93 odorants against 464 ORs expressed in heterologous cells and identified agonists for 52 mouse and 10 human ORs. We used the resulting interaction profiles to develop a predictive model relating physicochemical odorant properties, OR sequences, and their interactions. Our results provide a basis for translating odorants into receptor neuron responses and for unraveling mammalian odor coding.
Exercise prevents sleep deprivation-associated anxiety-like behavior in rats: Potential role of oxidative stress mechanisms

Our previous work suggests that pharmacological induction of oxidative stress causes anxiety-like behavior in rats. Interestingly, sleep deprivation is reported to cause oxidative damage in the brain and is also reported to be anxiogenic. Minimal mechanistic insights are available. In this study, using a behavioral and biochemical approach, we investigated involvement of oxidative stress mechanisms in sleep deprivation-induced anxiety-like behavior of rats and the protective role of treadmill exercise in this process. We report that acute sleep deprivation (SD) increases oxidative stress in the cortex, hippocampus and amygdala while prior treadmill exercise prevents this increase. Serum corticosterones also increase with SD but its levels are normalized in exercised sleep-deprived rats. Also, anxiety-like behavior of rats significantly increases with SD while prior treadmill exercise prevents this increase. Protein expression of two enzymes involved in antioxidant defense, glyoxalase (GLO)-1 and glutathione reductase (GSR)-1 increased after 24h SD in the hippocampus, cortex and amygdala while their levels were normalized in exercised sleep-deprived rats. It is plausible that oxidative stress via regulation of GLO1 and GSR1 is involved in sleep deprivation-induced anxiety-like behavior of rats.
Keynote address—Adjuvant chemotherapy and cancer cure

Abstract The use of chemotherapy as an adjuvant to surgery and/or radiotherapy is well founded in experimental tumor systems, and appears to be effective in patients in some circumstances. It is clear from both clinical and experimental studies that (1) the dose is important, (2) the earlier chemotherapy is started after primary therapy the better, and (3) combination chemotherapy may be more effective than single agent treatment. The better the risk of recurrence can be estimated, the better the risk-benefit ratio using adjuvant therapy can be assessed. Not only is the relative risk of recurrence to be considered in the decision as to what patients are to be treated, but also the success of “salvage” therapy. Finally, some evidence is presented to indicate that alkylating agents may not be necessary in combination regimens for adjuvant therapy if effective antimetabolite combinations are available.
Pion mass and decay constant

Independent of assumptions about the form of the quark-antiquark scattering kernel we derive the explicit relation between the pion Bethe-Salpeter amplitude, {Gamma}{pi}, and the quark propagator in the chiral limit; {Gamma}{pi} necessarily involves a non-negligible {gamma}{sub 5}{gamma} x P term (P is the pion four-momentum). We also obtain exact expressions for the pion decay constant, f{sub {pi}}, and mass, both of which depend on {Gamma}{sub {pi}}; and demonstrate the equivalence between f{sub {pi}} and the pion Bethe-Salpeter normalization constant in the chiral limit. We stress the importance of preserving the axial-vector Ward-Takahashi identity in any study of the pion itself, and in any study whose goal is a unified understanding of the properties of the pion and other hadronic bound states.
The precipitation of energetic heavy ions into the upper atmosphere of Jupiter

Evidence for auroral particle precipitation at Jupiter was provided by the ultraviolet spectrometers onboard the Voyagers 1 and 2 spacecraft and by the International Ultraviolet Explorer (IUE). Magnetospheric measurements made by instruments onboard the Voyager spacecraft show that energetic sulfur and oxygen ions are precipitating into the upper atmosphere of Jupiter. A theoretical model has been constructed describing the interaction of precipitating oxygen with the Jovian atmosphere. The auroral energy is deposited in the atmosphere by means of ionization, excitation, and dissociation and heating of the atmospheric gas. Energetic ion and electron precipitation are shown to have similar effects on the atmosphere and ionosphere of Jupiter.
Thermal Adaptation of Conformational Dynamics in Ribonuclease H

The relationship between inherent internal conformational processes and enzymatic activity or thermodynamic stability of proteins has proven difficult to characterize. The study of homologous proteins with differing thermostabilities offers an especially useful approach for understanding the functional aspects of conformational dynamics. In particular, ribonuclease HI (RNase H), an 18 kD globular protein that hydrolyzes the RNA strand of RNA:DNA hybrid substrates, has been extensively studied by NMR spectroscopy to characterize the differences in dynamics between homologs from the mesophilic organism E. coli and the thermophilic organism T. thermophilus. Herein, molecular dynamics simulations are reported for five homologous RNase H proteins of varying thermostabilities and enzymatic activities from organisms of markedly different preferred growth temperatures. For the E. coli and T. thermophilus proteins, strong agreement is obtained between simulated and experimental values for NMR order parameters and for dynamically averaged chemical shifts, suggesting that these simulations can be a productive platform for predicting the effects of individual amino acid residues on dynamic behavior. Analyses of the simulations reveal that a single residue differentiates between two different and otherwise conserved dynamic processes in a region of the protein known to form part of the substrate-binding interface. Additional key residues within these two categories are identified through the temperature-dependence of these conformational processes.
A taxonomy approach to simulation model documentation

In preparing this presentation I find myself in the ineluctable position of an applications-oriented practioners espousing a pedogical approach to simulation model documentation. Although theoretically cloistered in an academic environment, my teaching is applications-oriented and not theoretical, a reflection not only of my industrial background but also my lack of a formal theoretical education in computer science.
Human-computer dialogue design considerations☆

Abstract The three critical elements of quality human-computer dialogue design include a compilation of existing design guidelines, behavioral research to expand the general dialogue principles, and a computer-aided implementation for retrieval of the guidelines by dialogue authors. The need for empirically based dialogue guidelines relating to generic human-computer taks is stressed. The results of two studies dealing with interactive text editing are presented as examples of research directed toward specifying dialogue design principles and developing formal tools for human-computer dialogue research. One of these studies deals with a methodology for developing user models, and the second study deals with the design of HELP information. Computer-aiding in the form of rule-based systems for selecting appropriate dialogue guidelines and software tools for authoring dialogues are discussed as means for implementing these dialogue design considerations.
Application of a tandem metathesis to the synthesis of (+)-panepophenanthrin.

A novel total synthesis of (+)-panepophenanthrin (IV) via a tandem ring-closing metathesis/cross-metathesis sequence as key step is developed.
Application of the Tethered Biginelli Reaction for Enantioselective Synthesis of Batzelladine Alkaloids. Absolute Configuration of the Tricyclic Guanidine Portion of Batzelladine B.

Tethered Biginelli condensation of enantioenriched hexahydropyrrolopyrimidines 8 with β-ketoesters provides efficient asymmetric access to tricyclic guanidines 9 having a syn relationship of the angular C2a and C8a hydrogens. This reaction was employed to realize the first practical enantioselective access to this fragment of batzelladine alkaloids B (2) and E (5). The efficiency of this strategy is illustrated in the synthesis of the dextrorotatory enantiomer of batzelladine B methanolysis product 10 in 10 steps and 25% overall yield from 2-nonanone and methyl acetoacetate. The asymmetric synthesis of 10 establishes that the absolute configuration of the tricyclic portion of batzelladine B (2) is 25aR,28S,30R. The 4-methyl-7-alkyl-1,2,2a,3,4,5,6,7,8,8a-decahydro-5,6,8b-triazaacenaphthalene-3-carboxylic acid subunit, e.g., 29, of batzelladine alkaloids A (1), D (4), F (6), and G was also prepared for the first time by catalytic hydrogenation of tricyclic guanidines 26 having the 2a,8a-anti stereochemistry.
Efficient video sequence retrieval in large repositories

This paper presents algorithms to deal with problems associated with indexing high-dimensional feature vectors, which characterize video data. Indexing high-dimensional vectors is well known to be computationally expensive. Our solution is to optimally split the high dimensional vector into a few low dimensional feature vectors and querying the system for each feature vector. This involves solving an important subproblem: developing a model of retrieval which enables us to query the system efficiently. Once we formulate the retrieval problem in terms of a retrieval model, we present an optimality criterion to maximize the number of results using this model. The criterion is based on a novel idea of using the underlying probability distribution of the feature vectors. A branch-and-prune strategy optimized per each query, is developed. This uses the set of features derived from the optimality criterion. Our results show that the algorithm performs well, giving a speedup of a factor of 25 with respect to a linear search, while retaining the same level of recall.
Investigating technical and ecological efficiencies in the electricity generation industry: are there win-win opportunities?

Using data from the EPA's EGRID and Clean Air Markets databases, we investigate the energy (technical) and emissions (ecological) efficiencies of 437 of the largest US electricity generators. We focus on fossil-fuel-based electricity generating plants because of their significant impact on industry environmental performance, especially with respect to air media emissions. Data envelopment analysis is used to determine the relative technical and environmental performance of these plants and whether win-win opportunities and end-of-pipe versus in-process (reactive versus proactive) practices relate to these efficiencies. The results show that win-win opportunities in terms of simultaneous technical (operational) efficiency and ecological efficiency do not appear to exist.
A functional equation arising from multiplication of quantum integers

Abstract For the quantum integer [n]q=1+q+q2+⋯+qn−1 there is a natural polynomial multiplication such that [m]q⊗q[n]q=[mn]q. This multiplication leads to the functional equation fm(q)fn(qm)=fmn(q), defined on a given sequence F ={ f n (q)} n=1 ∞ of polynomials. This paper contains various results concerning the construction and classification of polynomial sequences that satisfy the functional equation, as well open problems that arise from the functional equation.
Time to step up to the plate: adopting the WHO 2006 growth curves for US infants.

Discusses the growth curves provided by the WHO, and the benefits and drawbacks for adopting there use for US infants.
Highly efficient hybrid fiber taper coupled microsphere laser

Summary form only given. High Q dielectric microcavities, in which light is trapped internally as whispering gallery mode (WGM) resonances, have attracted interest in applications as diverse as quantum optics and optical communications. Among these, rare-earth doped glass microsphere lasers have been demonstrated as potentially compact laser sources. We recently presented a fiber-taper coupled microsphere laser in the 1550-nm band, which exhibited efficient fiber to sphere coupling and the advantages of fiber compatibility. In this paper, we propose a novel hybrid-fiber-taper based laser coupling configuration, in which the microsphere is coupled using a single fiber taper that is a combination of 980-nm single mode fiber (SMF) and 1550-nm SMF. The pump source and the laser emission are then both guided in single mode fiber to or from the taper region. This structure has greatly improved the coupling of the fundamental pump mode to WGMs of the microsphere. In addition, the measured laser output power of 112-/spl mu/W is over an order of magnitude larger than our previous result. The differential quantum efficiency has been measured to be 12%.
Thermal Intramolecular (4 + 2) Cycloadditions of Allenamides: A Stereoselective Tandem Propargyl Amide Isomerization- Cycloaddition

A stereoselective intramolecular normal demand [4 + 2] cycloaddition of allenamides under thermal conditions without metal assistance is described. This work led to the development of a stereoselective tandem propargyl amide-isomerization−[4 + 2] cycloaddition sequence amenable for rapid assembly of complex nitrogen heterocycles.
Low energy electron diffraction and cyclic voltammetry studies of flame-annealed platinum single crystals

Abstract Low energy electron diffraction (LEED) and cyclic voltammetry were used to examine the surface structure of flame-annealed platinum (100), (110), and (111) electrodes. Well-defined LEED patterns were obtained for these surfaces but only after heat treatment in vacuo at 400°C in order to remove surface contaminants. The cyclic voltammograms correspond to those expected for these low index platinum surfaces from prior studies.
Defense Expenditures, Economic Growth, and The “Peace Dividend” A Longitudinal Analysis of 103 Countries

Despite the proliferation of studies on the impact of military spending on economic growth, it is still not known whether defense spending hinders or promotes growth. Most analysts attribute the lack of consistent/robust findings to three problems: the lack of a sound theory of defense-growth trade-offs, an inadequate research design, and a failure to account for the externality effects that defense spending might have on other parts of the economy. In this study, the authors try to remedy these problems by (1) relying on a model of the defense-growth trade-off that is grounded in the neoclassic theory of growth, (2) estimating this model using time-series data on 103 countries, and (3) explicitly accounting for the externality effects of defense spending by the use of a multisectorial model. The results show that, regardless of the specification of the models, and contrary to most cross-national studies, military expenditures have a significant positive effect on growth in only about 10% of the cases.
Demand and Supply Curves: Rotations versus Shifts

Virtually all principles and intermediate texts draw demand and supply curves as parallel shifts when a non-price variable changes its value, which implicitly assumes that the demand (or supply) relation is linear. But economists commonly speak of “the” income elasticity, as if it were constant (and not varying continuously as is the case with the linear specification). If the income elasticity is constant, then the demand curve must rotate when income changes.
Pd-catalyzed enantioselective allyl-allyl cross-coupling.

The Pd-catalyzed cross-coupling of allylic carbonates and allylB(pin) is described. The regioselectivity of this reaction is sensitive to the bite angle of the ligand, with small-bite-angle ligands favoring the branched substitution product. This mode of regioselection is consistent with a reaction that operates by a 3,3′ reductive elimination reaction. In the presence of appropriate chiral ligands, this reaction is rendered enantioselective and applies to both aromatic and aliphatic allylic carbonates.
Structural failure and nondestructive rheological analyses of frankfurter batters effects of heating rates and sugars

The effects of heating rate and sugar type and concentration on the values of frankfurter textural parameters at structural failure were evaluated by a torsion test and a two cycle uniaxial compression test. Structural failure tests indicated that heating rate and sugar concentration had major effects on shear stress; in addition to minor effects on true shear strain. In general, heating rate had a greater effect on stresses and strains than sugar. Torsion and compression tests yielded different values, however, trends due to treatment were similar. The method used for interpretation of texture profile analysis parameters from Instron force-deformation curves had an effect on the statistical analysis results. A thermal scanning rheology monitor nondestructively measured rheological changes during thermal processing. During thermal processing, the major modulus of rigidity increase started at 58°C and the major decrease in energy loss occurred in the 40–60°C range. Unlike structural failure rheological properties, rigidity at 70°C was not affected by heating rate.
How shall we go to Mars? A review of mission scenarios

Four scenarios for initial Mars missions are examined in this overview of strategies. The scenarios are compared to determine the most effective option with respect to the effects of reduced gravity, exposure to space radiation, and cost. Mission cost is evaluated based on initial mass in earth orbit for the four mission types: classes-opposition, conjunction, fast-transfer conjunction, and split sprint. The reduced gravitational force on the Martian surface is considered to be a critical factor because the physical deconditioning at 3/8 earth gravity is assumed to approximate that of zero gravity. Exposure to radiation is not determined to be a definite discriminator because none of the scenarios exceed established limits. The split sprint is championed based on the high energy transfers considered and with chemical propulsion (or preferably nuclear thermal propulsion) and aerobraking.
Settling Time and Noise Optimization of a Three-Stage Operational Transconductance Amplifier

This paper presents the design and optimization of a nested-Miller compensated, three-stage operational transconductance amplifier (OTA) for use in switched-capacitor (SC) circuits. Existing design methods for three-stage OTAs often lead to sub-optimal solutions because they decouple inter-related metrics like noise and settling performance. In our approach, the problem of finding an optimal design with the best total integrated noise and settling time has been cohesively solved by formulating a nonlinear constrained optimization program. Equality, inequality, and semi-infinite constraints are formed using closed form symbolic expressions obtained by a closed loop analysis of the SC gain stage and the optimization program is solved by using the interior-point algorithm. For the optimization routine, there is no need to interface with a circuit simulator because all significant device parasitics are included in the model. The optimization and modeling steps are general in nature and can be applied to any amplifier or filter topology. Simulation results show that a 90-nm prototype amplifier achieves a $\pm 0.1{\hbox{\%}}$ dynamic error settling time of 2.5 ns with a total integrated noise of 240 $\mu {\rm V}_{\rm rms}$ , while consuming 5.2 mW from a 1-V power supply.
Synchrotron radiation at radio frequencies from cosmic ray air showers

Abstract We review some of the properties of extensive cosmic ray air showers and describe a simple model of the radio-frequency radiation generated by shower electrons and positrons as they bend in the Earth’s magnetic field. We perform simulations by calculating the trajectory and radiation of a few thousand charged shower particles. The results are then transformed to predict the strength and polarization of the electromagnetic radiation emitted by the whole shower.
Myeloma bone disease: Pathophysiology and management

Multiple myeloma bone disease is marked by severe dysfunction of both bone formation and resorption and serves as a model for understanding the regulation of osteoblasts (OBL) and osteoclasts (OCL) in cancer. Myeloma bone lesions are purely osteolytic and are associated with severe and debilitating bone pain, pathologic fractures, hypercalcemia, and spinal cord compression, as well as increased mortality. Interactions within the bone marrow microenvironment in myeloma are responsible for the abnormal bone remodeling in myeloma bone disease. Myeloma cells drive bone destruction that increases tumor growth, directly stimulates the OCL formation, and induces cells in the marrow microenvironment to produce factors that drive OCL formation and suppress OBL formation. Factors produced by marrow stromal cells and OCL promote tumor growth through direct action on myeloma cells and by increasing angiogenesis. Current therapies targeting MMBD focus on preventing osteoclastic bone destruction; however regulators of OBL inhibition in MMBD have also been identified, and targeted agents with a potential anabolic effect in MMBD are under investigation. This review will discuss the mechanisms responsible for MMBD and therapeutic approaches currently in use and in development for the management of MMBD.
Dynamic Analysis of Turbulent Annular Seals Based On Hirs’ Lubrication Equation

Expressions are derived which define dynamic coefficients for high-pressure annular seals typical of neck-ring and interstage seals employed in multistage centrifugal pumps. Completely developed turbulent flow is assumed in both the circumferential and axial directions, and is modeled in this analysis by Hirs' turbulent lubrication equations. Linear zeroth and first-order 'short-bearing' perturbation solutions are developed by an expansion in the eccentricity ratio. The influence of inlet swirl is accounted for in the development of the circumferential flow field. Comparisons are made between the stiffness, damping, and inertia coefficients derived herein based on Hirs' model and previously published results based on other models. Finally, numerical results are presented for interstage seals in the Space Shuttle Main Engine High Pressure Fuel Turbopump and a water pump.
Relation of Structure to Properties in Polyurethanes. Effect of Branching

Abstract Attaching short N-arylurethane branches to a high molecular weight, linear polyether urethane introduces interchain forces—very likely arising from hydrogen bonding—which increase as the side chains become more polar. These forces are sufficiently strong to increase the bulk viscosity of the raw polymers and, with the more highly polar groups, are strong enough to impart an appreciable elastic memory. At slightly elevated temperatures (80° C) these forces are reduced considerably, which is to be expected if they arise through hydrogen bonding. However they are either not strong enough or are too limited in number to compete with the covalent crosslinks in the elastomer vulcanizates. Thus no significant alteration is observed in the vulcanizate properties which are customarily measured. The marked effect of these short aryl side chains to reduce crystallization tendencies can most likely be attributed to the bulkiness. of the pendant aryl moiety, which prevents—or slows down—the ordering of the po...