cssi/SciSciGPT-SciSciNet huggingface dataset:
No skew branes on non-degenerate hyperquadrics

We show that non-degenerate hyperquadrics in Rn+2 admit no skew n-branes. Stated more traditionally, a compact codimension-one immersed submanifold of a non-degenerate hyperquadric of euclidean space must have parallel tangent spaces at two distinct points. Similar results have been proven by others, but (except for ellipsoids in R3, Proc. Amer. Math. Soc. 133:3687–3690, 2005) always under C2 smoothness and genericity assumptions. We use neither assumption here.
Gravitational Lorentz violations and adjustment of the cosmological constant in asymmetrically warped spacetimes

Abstract We investigate spacetimes in which the speed of light along flat 4D sections varies over the extra dimensions due to different warp factors for the space and the time coordinates (“asymmetrically warped” spacetimes). The main property of such spaces is that while the induced metric is flat, implying Lorentz invariant particle physics on a brane, bulk gravitational effects will cause apparent violations of Lorentz invariance and of causality from the brane observer's point of view. An important experimentally verifiable consequence of this is that gravitational waves may travel with a speed different from the speed of light on the brane, and possibly even faster. We find the most general spacetimes of this sort, which are given by AdS–Schwarzschild or AdS–Reissner–Nordstrom black holes, assuming the simplest possible sources in the bulk. Due to the gravitational Lorentz violations these models do not have an ordinary Lorentz invariant effective description, and thus provide a possible way around Weinberg's no-go theorem for the adjustment of the cosmological constant. Indeed we show that the cosmological constant may relax in such theories by the adjustment of the mass and the charge of the black hole. The black hole singularity in these solutions can be protected by a horizon, but the existence of a horizon requires some exotic energy densities on the brane. We investigate the cosmological expansion of these models and speculate that it may provide an explanation for the accelerating Universe, provided that the timescale for the adjustment is shorter than the Hubble time. In this case the accelerating Universe would be a manifestation of gravitational Lorentz violations in extra dimensions.
Prototyping in ADA: a case study

Prototypes provide a means for obtaining rapid feedback concerning the design of a system. Ideally, a prototype system should be easy to implement and modify; moreover, it should implement enough of the system's functionality to allow an evaluation of the design.The Ada programming language, with emphasis on modularity and well-defined module interfaces, appears suitable for implementing prototype systems. This paper describes how one could develop a prototype in Ada for a small real-time control program and then successively enhance the prototype to produce the final production version.
Evaluation of a novel design for an electrostatic quadrupole triplet ion beam lens

We describe the design and evaluation of an electrostatic quadrupole triplet lens constructed to focus ion beams of up to 200 keV in energy. The lens is very compact and incorporates a feature to induce octupole fields that can correct for spherical and other octupole-order aberrations. Two methods were used to evaluate the lens: observation of the focused beam spot on a specially fabricated target while systematically varying lens voltages, and the grid-shadow technique. The latter demonstrated that octupole-order aberrations were completely corrected in one direction when the lens quadrupoles were operated individually and excited to produce an appropriate octupole component of the electric field.
Noncompact lattice simulations of SU(2) gauge theory

Abstract Wilson loops have been measured at strong coupling, β =0.5, on a 12 4 lattice in noncompact simulations of pure SU(2) without gauge fixing. There is no sign of quark confinement.
Modeling of a Steam Turbine Including Partial Arc Admission for Use in a Process Simulation Software Environment

A dynamic process model of a steam turbine, including partial arc admission operation, is presented. Models were made for the first stage and last stage, with the middle stages presently assumed to have a constant pressure ratio and efficiency. A condenser model is also presented. The paper discusses the function and importance of the steam turbines entrance design and the first stage. The results for steam turbines with a partial arc entrance are shown, and compare well with experimental data available in the literature, in particular, the “valve loop” behavior as the steam flow rate is reduced. This is important to model correctly since it significantly influences the downstream state variables of the steam, and thus the characteristic of the entire steam turbine, e.g., state conditions at extractions, overall turbine flow, and condenser behavior. The importance of the last stage (the stage just upstream of the condenser) in determining the overall flowrate and exhaust conditions to the condenser is described and shown via results.
Compact, tunable large group delay line

In this paper, we present a compact, tunable delay line based on left-handed nonlinear transmission line (LH NLTL). The widely tunable range of the large group delay is achieved by controlling a reverse bias voltage of series varactors in the LH NLTL. The proposed tunable delay line can be made in a very compact form because its size is dominated by the cascaded varactors. Our experiment shows that the fabricated prototype exhibits tunable group delay between 1.2 and 2.2 ns at a frequency of 1.42 GHz and good return loss. The circuit size is merely 1.6 cm in length. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2893–2895, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24747
A community of individuals: Cooperation and individualization in computer science education

Abstract A model of education based on cooperation among responsible individuals is presented. Earlier models are discussed which involve traditional competitive-based courses as well as the more recent individualized mode. The latter has been used by the author for several years, utilizing both a personalized system of instruction (PSI) and computer-based education (CBE). Now, however, cooperation has been introduced as an explicit and integral part of education. This was done in the belief that most serious problems of our day are amenable to a cooperative problem-solving process. The techniques utilized in an introductory computer science course include: study partners for PSI units, computerized personal data base design by a small group, mutual design and use of interactive programs, use of cooperative exercises (computer and otherwise) and parties. The future of these efforts remains unknown, but there is a strong belief that cooperation is a preferable model to competition in the world to come.
What makes a currency procyclical? An empirical investigation

This paper looks at the correlation between the cyclical components of gross domestic product and the exchange rate and classifies countries' currencies as procyclical if they appreciate in good times, countercyclical if they appreciate in bad times, and acyclical otherwise. With this classification, the paper shows that: (i) the countries that are commodity exporters and experience procyclical capital flows tend to have procyclical currencies; (ii) countries with procyclical currencies tend to restrict their capital accounts, perhaps as an attempt to reduce the degree of procyclicality; (iii) countries with procyclical currencies pursue procyclical monetary policy; (iv) however, in the last decade, there is a disconnect between the cyclicality of currency and monetary policy; and (v) the disconnect may reflect a decline in the fear of floating, which can be partially attributed to an improvement in countries' net foreign asset positions.
Transient loads on buildings in microburst and tornado winds

This paper presents both quasi-steady and transient wind load effects on a cubic building in a microburst and a tornado. Large eddy simulation (LES) was used to simulate the loading effects of a translating microburst with a 0.20-m-diameter jet at four different translating velocities on a 25 mm cube. The results of the numerical simulation were compared with data from a laboratory microburst simulator. The numerical simulation predicted an increase in drag forces with increase in microburst translation speed. The transient loading effects on a 229 mm cubic building from a translating tornado were also simulated in a laboratory for two different vortex core diameters and two translating speeds and the peak loads were studied. Results for the cubic building were compared with that of a tall building under the same loading conditions. Finally, peak loads and peak moments measured in this study were compared to the corresponding values specified in ASCE 7-05 [2006. Minimum Design Loads for Buildings and Other Structures, 2006. ASCE Standard, SEI/ASCE 7-05, American Society of Civil Engineers] and found to exceed them by a factor of 1.5 or more for buildings located in tornado alley of the United States subjected to tornadoes of F2 or higher intensity.
Ginzburg–Landau model for a long-pulse low-gain free-electron laser oscillator

Abstract The Ginzburg–Landau model for the radiation field of a free-electron laser (FEL) was originally derived for a high-gain amplifier (S.Y. Cai and A. Bhattacharjee, Phys. Rev. A 43 (1991) 6934). With a view to making precise comparisons with experimental data from the long-pulse FEL oscillator at the University of California at Santa Barbara (UCSB) (L.R. Elias, G. Ramian, J. Hu, A. Amir, Phys. Rev. Lett. 57 (1986) 424), we have developed a new formulation of the Ginzburg–Landau model starting from the low-gain oscillator equations. We implement a small-amplitude expansion of the radiation field, and derive the coefficients of the Ginzburg–Landau equation by analysis as well as by Mathematica. Stability analysis of the Ginzburg–Landau equation produces results similar to those obtained by T.M. Antonsen and B. Levush (Phys. Fluids B 1 (1989) 1097). These include the stability of the main mode (no Benjamin–Feir instability), phase-unstable off-centered modes (Eckhaus instability), as well as relaxation to the single mode which occurs much faster in amplitude than in phase. We obtain the saturated radiation amplitude a0 as functions of the detuning parameter pinj and cavity loss, and determine the phase instability boundary in the a0−pinj plane. The probability of realizing a single mode starting with random initial conditions is calculated and compared with spectral measurements from the UCSB FEL.
Panal: A possible precursor of fungal luciferin

Abstract A new sesquiterpene named panal was isolated from the luminous mushroom Panellus stipticus . Upon treatment with salts of ammonia or primary amines, panal yields a substance(s) which emits light in the presence of Fe2+, H2O2, and surfactants. On the basis of chemical and spectroscopic data, the structure 1 was assigned to panal,excluding the absolute configuration.
The rise and decline of managerial development

Alfred D. Chandler's work highlighted the complicated interplay between markets and firms, especially the arrangements created by firms to buffer and manage market forces. Arguably his most important work examines one aspect of firms, organizational structure, and how it changed in response to the competitive needs of growing businesses. Much the same approach can be applied to understanding other aspects of firms such as the structure of the most important jobs in corporations, executive positions, and how those positions have been filled over time. Here the interplay includes a different market, the labor market. The arguments that follow trace the evolution of executive roles from the early days of corporations, where executive jobs were largely shaped by the labor market, to internalized and bureaucratized arrangements consistent with the idea of an integrated "Chandlerian" firm after the 1950s, back to something much closer to the market-dominated approach following the 1982 recession. In large measure, the change seems driven by the different context that business faced and the interplay with labor markets that made internal development more difficult. The implications for the future of large-scale Chandlerian firms may be considerable. Copyright 2010 The Author 2010. Published by Oxford University Press on behalf of Associazione ICC. All rights reserved., Oxford University Press.
Thermal Resistance of Particle Laden Polymeric Thermal Interface Materials

Particle laden polymers are one of the most prominent thermal interface materials (TIM) used in electronics cooling. Most of the research has primarily dealt with the understanding of the thermal conductivity of these types of TIMs. For thermal design, reduction of the thermal resistance is the end goal. Thermal resistance is not only dependent on the thermal conductivity, but also on the bond line thickness (BLT) of these TIMs. It is not clear which material property(s) of these particle laden TIMs affects the BLT and eventually the thermal resistance. This paper introduces a rheology based semiempirical model for the prediction of the BLT of these TIMs. BLT depends on the yield stress of the particle laden polymer and the applied pressure. The BLT model combined with the thermal conductivity model can he used for modeling the thermal resistance of these TIMs for factors such as particle volume faction, particle shape, base polymer viscosity, etc.
Simulation of mercury emission control by activated carbon under confined-bed operations

Mercury emissions from coal-fired power plants have been a great environmental and regulatory concern due to the toxic nature of mercury and the significant amount of emissions from these plants. An effective method for controlling mercury emission is to employ activated carbon to adsorb mercury from the combustion flue gas. In this study, an activated carbon mercury sorption model was applied to simulate a confined-bed mercury emission control process. Model simulations were performed to generate dynamic mercury concentration profiles and the corresponding profiles of mercury uptake by activated carbon at various bed locations under various process conditions. The simulation parameters included flue gas flow rate, inlet mercury concentration, and adsorption bed temperature. The study has demonstrated the applicability of the model for simulating the process and provided insights into the mercury control process especially the effects of flue gas flow rate, inlet mercury concentration, and activated carbon bed temperature on the process. Such information is critically needed in the design and operation of a mercury emission control process involving activated carbon adsorption.
Numerical simulation of turbulent cylinder juncture flowfields

Steady high-Reynolds-number subsonic and supersonic flowfields about a circular cylinder mounted upright on a flat plate were simulated numerically by integration of the time-dependent three-dimensional compressible mass-averaged Navier-Stokes equations. Effects of turbulence were represented by a two-equation (k-e) closure model that included a generalized formulation and low-Reynolds-number terms. For the supersonic case, the turbulence equations incorporated a compressibility correction. Grid mesh step-size studies were performed to assess resolution requirements of the solutions. Comparison is made with experimental data in terms of static pressure and total pressure loss coefficients, velocity distributions, and surface limiting streamline patterns
Interstellar organic matter in meteorites

Hydrogen which is highly enriched in deuterium is present in organic matter in a variety of meteorites including non-carbonaceous chondrites. The concentrations of this hydrogen are quite large. For example Renazzo contains 140 μmoles/g of the 10,000‰ δD hydrogen. The D/H ratios of hydrogen in the organic matter vary from 8 × 10^(−5) to 170 × 10^(−5) (δD ranges from − 500‰ to 10,000‰) as compared to 16 × 10^(−5) for terrestrial hydrogen and 2 × 10^(−5) for cosmic hydrogen. The majority of the unequilibrated primitive meteorites contain hydrogen whose D/H ratios are greater than 30 × 10^(−5). If the D/H ratios in these compounds were due to enrichment relative to cosmic hydrogen by isotope exchange reactions, it would require that these reactions take place below 150 K. In addition the organic compounds having D/H ratios above 50 × 10^(−5) would require temperatures of formation of < 120 K. These types of deuterium enrichments must take place by ion-molecule reactions in interstellar clouds where both ionization and low temperatures exist. Astronomically observed D/H ratios in organic compounds in interstellar clouds are typically 180 × 10^(−5) and range between about 40 × 10^(−50 and 5000 × 10^(−5). The D/H values we have determined are the lower limits for the organic compounds derived from interstellar molecules because all processes subsequent to their formation, including terrestrial contamination, decrease their D/H ratios. In contrast, the D/H ratios of hydrogen associated with hydrated silicates are relatively uniform for the meteorites we have analyzed with an average value of 14 × 10^(−5); very similar to the terrestrial value. These phyllosilicates values suggest equilibration of H_2O with H_2 in the solar nebula at temperatures of about 200 K and higher. The ^(13)C/^(12)C ratios of organic matter, irrespective its D/H ratio, lie well within those observed for the earth. If organic matter originated in the interstellar medium, our data would indicate that the ^(13)C/^(12)C ratio of interstellar carbon five billion years ago was similar to the present terrestrial value. Our findings suggest that other interstellar material, representing various inputs from various stars, in addition to the organic matter is preserved and is present in the meteorites which contain the high D/H ratios. We feel that some elements existing in trace quantities which possess isotopic anomalies in the meteorites may very well be such materials.
Structural Polarity Induced by Cooperative Hydrogen Bonding and Lone-Pair Alignment in the Molecular Uranyl Iodate Na2[UO2(IO3)4(H2O)]

Na2[UO2(IO3)4(H2O)] has been synthesized under mild hydrothermal conditions. Its structure consists of Na+ cations and [UO2(IO3)4(H2O)](2-) anions. The [UO2(IO3)4(H2O)](2-) anions are formed from the coordination of a nearly linear uranyl, UO2(2+), cation by four monodentate IO(3-) anions and a coordinating water molecule to yield a pentagonal bipyramidal environment around the uranium center. The water molecules form intermolecular hydrogen bonds with the terminal oxo atoms of neighboring [UO2(IO3)4(H2O)](2-) anions to yield one-dimensional chains that extend down the b axis. There are two crystallographically unique iodate anions in the structure of Na2[UO2(IO3)4(H2O)]. One of these anions is aligned so that the lone-pair of electrons is also directed along the b axis. The overall structure is therefore polar, owing to the cooperative alignment of both the hydrogen bonds and the lone-pair of electrons on iodate. The polarity of the monoclinic space group C2 (a = 11.3810(12) A, b = 8.0547(8) A, c = 7.6515(8) A, beta = 90.102(2) degrees , Z = 2, T = 193 K) found for this compound is consistent with the structure. Second-harmonic generation of 532 nm light from a 1064 nm laser source yields a response of approximately 16x alpha-SiO2.
Receiver design considerations for solar central receiver hydrogen production

Abstract The status of the Solar Central Receiver or Power Tower developments is briefly reviewed. with particular consideration given to the application of this technology to thermochemical hydrogen production. Emphasis is on the general considerations in the receiver-chemical reactor interface. High solar flux densities of 1.5–3 MW M −2 must be transformed to 50–100 kW M −2 for catalytic decomposition of sulfuric acid such as in the General Atomic (GA) water-splitting reactions. The different methods considered to accomplish such reactions include cavities, external heat pipe receivers, a falling curtain of particles, and other direct absorption media coupled to chemical reactions.
Benefits of in-Vehicle Consolidation in Less than Truckload Freight Transportation Operations

Abstract Researchers and public agencies have proposed consolidation policies as an alternative to increase truck payload utilization and mitigate externalities produced by freight transportation. Understanding and enhancing the economic mechanisms that lead to freight consolidation can ease the implementation of these strategies, increase profits for shippers and carriers, and reduce freight-related negative externalities. An important mechanism that has recently been studied for cost reduction in the freight industry is combinatorial auctions. In these auctions, a shipper invites a set of carriers to submit bids for freight lane contracts. Carriers can bid for individual lanes or bundles of them according to their operational characteristics. These bids are constructed considering direct shipments (Truckload operations) and several biding advisory models have been proposed for this purpose. However, there are economies of scale that can be achieved if shipments are consolidated inside vehicles, which have not been explored in the construction of competitive bids. This paper investigates such benefits and provides insights on the competitiveness and challenges associated to the development of consolidated bids (suitable for Less-than-Truckload operations). Consolidated bids are constructed using a multi-commodity one-to-one pickup-and-delivery vehicle routing problem that is solved using a branch-and-price algorithm. The numerical experiment shows that non-consolidated bids are dominated by consolidated bids, which implies that this type of operation can increase the likelihood of a carrier to win auctioned lanes, while increasing its profits margins over truckload companies (non-consolidated bids), and keeping the reported benefits that combinatorial auctions represent for shippers.
Are There Incongruent Ground States in 2D Edwards–Anderson Spin Glasses?

We present a detailed proof of a previously announced result [1] supporting the absence of multiple (incongruent) ground state pairs for 2D Edwards–Anderson spin glasses (with zero external field and, e.g., Gaussian couplings): if two ground state pairs (chosen from metastates with, e.g., periodic boundary conditions) on ℤ2 are distinct, then the dual bonds where they differ form a single doubly-infinite, positive-density domain wall. It is an open problem to prove that such a situation cannot occur (or else to show – much less likely in our opinion – that it indeed does happen) in these models. Our proof involves an analysis of how (infinite-volume) ground states change as (finitely many) couplings vary, which leads us to a notion of zero-temperature excitation metastates, that may be of independent interest.
DECONSTRUCTION AND OTHER APPROACHES TO SUPERSYMMETRIC LATTICE FIELD THEORIES

This paper contains both a review of recent approaches to supersymmetric lattice field theories and some new results on the deconstruction approach. The essential reason for the complex phase problem of the fermion determinant is shown to be derivative interactions that are not present in the continuum. These irrelevant operators violate the self-conjugacy of the fermion action that is present in the continuum. It is explained why this complex phase problem does not disappear in the continuum limit. The fermion determinant suppression of various branches of the classical moduli space is explored, and found to be supportive of previous claims regarding the continuum limit.
Adversarial Deletion in a Scale-Free Random Graph Process

We study a dynamically evolving random graph which adds vertices and edges using preferential attachment and is ‘attacked by an adversary’. At time $t$, we add a new vertex $x_t$ and $m$ random edges incident with $x_t$, where $m$ is constant. The neighbours of $x_t$ are chosen with probability proportional to degree. After adding the edges, the adversary is allowed to delete vertices. The only constraint on the adversarial deletions is that the total number of vertices deleted by time $n$ must be no larger than $\delta n$, where $\delta$ is a constant. We show that if $\delta$ is sufficiently small and $m$ is sufficiently large then with high probability at time $n$ the generated graph has a component of size at least $n/30$.
Role of ortho-substituents on rhodium-catalyzed asymmetric synthesis of β-lactones by intramolecular C-H insertions of aryldiazoacetates.

A rhodium-catalyzed asymmetric synthesis of β-lactones via intramolecular C–H insertion into the ester group of aryldiazoacetates has been developed. The β-lactones were synthesized in high yields and with high levels of diastereo- and enantioselectivity. Halo and trifluoromethyl substituents at the ortho position of the aryldiazoacetates enhance intramolecular C–H insertions over intermolecular reactions, allowing C–H insertion of even methyl C–H bonds.
Total Syntheses of the Elusive Welwitindolinones with Bicyclo[4.3.1] Cores

The welwitindolinones with bicyclo[4.3.1] cores are a class of natural products that have attracted tremendous interest from the synthetic community because of their fascinating structures and promising biological profiles. More than 15 research groups worldwide have reported progress toward these elusive natural products. This Minireview describes contemporary studies aimed at the total synthesis of these challenging targets, in addition to the two recently completed syntheses of welwitindolinones with bicyclo[4.3.1] cores reported by Rawal and Garg in 2011. Both of the completed efforts rely on C4-C11 bond constructions to access the congested bicyclic framework of these elusive natural products.
Polynomial algorithms for linear programming over the algebraic numbers

We derive a bound on the computational complexity of linear programs whose coefficients are real algebraic numbers. Key to this result is a notion of problem size that is analogous in function to the binary size of a rational-number problem. We also view the coefficients of a linear program as members of a finite algebraic extension of the rational numbers. The degree of this extension is an upper bound on the degree of any algebraic number that can occur during the course of the algorithm, and in this sense can be viewed as a supplementary measure of problem dimension. Working under an arithmetic model of computation, and making use of a tool for obtaining upper and lower bounds on polynomial functions of algebraic numbers, we derive an algorithm based on the ellipsoid method that runs in time bounded by a polynomial in the dimension, degree, and size of the linear program. Similar results hold under a rational number model of computation, given a suitable binary encoding of the problem input.
Active Cavity Radiometer Type IV

A new cavity pyrheliometer, the active cavity radiometer type IV (ACR IV), has been developed for the measurement of total solar optical irradiance. Analysis predicts its ability to measure at the solar constant level with 0.1% uncertainty in SI units. In comparison tests ACR IVs have consistently demonstrated 0.5% higher results than the World Radiometrie Reference scale. A prototype has been tested, and a flight instrument has been developed and flown in a sounding rocket experiment to determine the solar constant. ACR IV instrumentation is being developed for flight experiments on the Spacelab 1 and Solar Maximum Missions to monitor the total solar output of optical radiation as part of a long-term program to detect variations of climatological significance.
Active cooling control of the CLEO detector using a hydrocarbon coolant farm

Abstract We describe a novel approach to particle-detector cooling in which a modular farm of active coolant-control platforms provides independent and regulated heat removal from four recently upgraded subsystems of the CLEO detector: the ring-imaging Cherenkov detector, the drift chamber, the silicon vertex detector, and the beryllium beam pipe. We report on several aspects of the system: the suitability of using the aliphatic-hydrocarbon solvent PF TM -200IG as a heat-transfer fluid, the sensor elements and the mechanical design of the farm platforms, a control system that is founded upon a commercial programmable logic controller employed in industrial process-control applications, and a diagnostic system based on virtual instrumentation. We summarize the system's performance and point out the potential application of the design to future high-energy physics apparatus.
Discovery of a Nuclear X-Ray Source in NGC 7331: Evidence for a Massive Black Hole

Using ROSAT, we have made the first deep X-ray observations of NGC 7331, discovering a nuclear X-ray source coincident with the previously determined radio and optical nuclear centers. The positions, luminosities, and fluxes of X-ray sources in the field are compared with previously identified radio and optical sources. The nucleus of NGC 7331 has been analyzed to discern any new evidence supporting the presence of a massive black hole, and comparisons are made with other low-ionization nuclear emission-line region (LINER) galaxies. The flux ratio of core radio to soft X-ray emission in NGC 7331 is lower than in other LINERs included in our sample.
Nutritional Aspects of Cancer-Related Fatigue

Abstract Fatigue, which may well be the most common experience of patients with cancer, remains underappreciated by health care professionals. Perhaps one reason is that because of its complexity and many components, fatigue is not completely understood. Knowledge of fatigue models, such as the Integrated Fatigue Model of Piper, can help dietitians identify potential causes of fatigue such as activity-rest patterns, and identification can lead dietitians to early intervention. Understanding cancer treatment factors, such as nausea and decreased participation in activities of daily living, that are believed to play a part in fatigue form another level on which dietitians can provide intervention. Through intervention, dietitians, working with patients and other members of the multidisciplinary team, may increase the understanding and appreciation of fatigue as well as provide relief from it. Efforts to maintain nutritional status can decrease or prevent some of the fatigue associated with cancer and its treatment. Therefore, the goal of clinical dietitians who work with a fatigued patient with cancer is to use nutrition management to minimize therapeutic side effects and maximize the patient's nutritional parameters.
Structure of (-)-neodysidenin from Dysidea herbacea. Implications for biosynthesis of 5,5,5-trichloroleucine peptides.

Neodysidenin was isolated from the marine sponge Dysidea herbacea (Keller 1889) collected on the Great Barrier Reef. The complete configuration was obtained from a combination of methods, including capillary electrophoresis of Marfey's derivatives. Neodysidenin belongs to the l-series of trichloroleucine peptides, and the configuration of the N-methyl thiazolyl alanine residue (13R) is opposite to that of dysidenin.
A classification of hidden-variable properties

Hidden variables are extra components added to try to banish counterintuitive features of quantum mechanics. We start with a quantum-mechanical model and describe various properties that can be asked of a hidden-variable model. We present six such properties and a Venn diagram of how they are related. With two existence theorems and three no-go theorems (EPR, Bell and Kochen?Specker), we show which properties of empirically equivalent hidden-variable models are possible and which are not. Formally, our treatment relies only on classical probability models, and physical phenomena are used only to motivate which models to choose.
Synthesis of selenium-derivatized cytidine and oligonucleotides for X-ray crystallography using MAD.

Synthesis of the novel 2‘-Se-cytidine phosphoramidite was achieved via transformation of the uridine analogue to the cytidine derivative in high yield. This 2‘-Se-cytidine phosphoramidite was used to synthesize selenium-derivatized DNA and RNA oligonucleotides for X-ray crystallography using MAD. The nucleotide coupling yield using this novel phosphoramidite was over 99% when 5-benzylmercaptotetrazole (5-BMT) was used as the coupling reagent.
Classical Information Capacity of the Bosonic Broadcast Channel

We show that when coherent-state encoding is employed in conjunction with coherent detection, the Bosonic broadcast channel is equivalent to a classical degraded Gaussian broadcast channel whose capacity region is dual to that of the classical Gaussian multiple-access channel. We further show that if a minimum output-entropy conjecture holds true, then the ultimate classical information capacity of the Bosonic broadcast channel can be achieved by a coherent-state encoding. We provide some evidence in support of the conjecture.
A Fully Three-Dimensional Inverse Method for Turbomachinery Blading in Transonic Flows

This paper presents a procedure to extend a recently developed fully three-dimensional inverse method for highly loaded turbomachine blades into the transonic-flow regime. In this inverse method, the required three-dimensional blade profile to produce a prescribed swirl schedule is determined iteratively using the blade boundary conditions. In the present implementation, the flow is assumed to be inviscid and the blades are assumed to be infinitely thin. The relevant equations are solved in the conservative forms and are discretized in all three directions using a finite-volume technique. Calculations are carried out for the design of high-pressure axial- and centrifugal-compressor rotors. These examples include prescribed swirl schedules corresponding to blade designs that are shock-free and blade designs that have rapid compression regions in the blade passage.
Model Geometries for sickled erythrocytes

Abstract Proposed model geometries are described for three types of axisymmetric and four types of flattened sickled erythrocytes. The axisymmetric types are designated as concave–convex, convex–convex and parabolic, while the flattened types carry designations of concave–convex, convex–convex, parabolic and S-shaped. Formulae are provided for the volume and surface area of each type and a figure showing the profile of each is included. Measurements of actual sickled cells in vitro could be used to find values for the volume and surface area of each type of cell by using parameter values for the appropriate model geometry. These would give close approximations that could be useful in clinical therapies and laboratory investigations for sickle cell anemia. Surface area to volume ratios can also be found to a close approximation for each cell type.
Convolution, filtering, linear systems, the Wiener-Khinchin theorem: generalizations

A simple formulation is given for generating convolution theorems in any representation. Using this method we obtain the convolution theorem for the scale representation. We generalize the concept of invariance to any basis set and devise a method for handling linear invariant systems for arbitrary quantities. The Wiener-Khinchin theorem is generalized to arbitrary power energy densities. Also, we show how standard probability theory can be formulated in terms of signals.
Isopiestic determination of the osmotic and activity coefficients of ZnCl2(aq) at 298.15 K

Abstract Isopiestic vapor-pressure measurements were performed at 83 molalities of ZnCl 2 (aq) from 0.31358 to 13.134 mol · kg −1 at 298.15 K. Measurements were made by using high-purity ZnCl 2 adjusted to its stoichiometric pH value. Our results are critically compared with previous isopiestic, direct vapor-pressure, and e.m.f. measurements, and recommended values are reported for osmotic coefficients, water activities, solute activity coefficients, and chemical-potential derivatives. Published isopiestic values for ZnCl 2 (aq) up to 10 mol · kg −1 and most e.m.f. values up to about 6 mol · kg −1 generally agree well with our experimental results, but some e.m.f. results and direct vapor-pressure measurements appear to have been inaccurate.
Interaction of radiation with turbulence - application to a combustion system

Turbulence/radiation interaction is examined in order to provide better fundamental understanding of temporal aspects of radiative transfer in combustion systems. Two aspects of radiative transfer in a turbulent medium are considered in this paper. In the first, transfer of radiation along a path with turbulent concentration and temperature fluctuations is calculated for the time-mean irradiance at a combustion chamber wall due to random concentration of absorbing species and emission with Gaussian probability density functions. In the second, turbulence/radiation interaction and the effect of radiation transfer on the fully coupled structure and mean properties are assessed for an industrial natural gas-fired furnace. The results of calculations based on the approximate formulation utilized here show that the effects of turbulence/radiation interaction on combustion and flow properties is relatively small for a preheated methane-air mixture. The interaction is greater when the oxidant is cold and the flame is relatively long. 24 references.
Malmquist Bias and the Distance to the Virgo Cluster

This paper investigates the impact of Malmquist bias on the distance to the Virgo cluster determined by the H0 Key Project using M100, and consequently on the derived value of H0. Malmquist bias is a volume-induced statistical effect which causes the most probable distance to be different from the raw distance measured. Consideration of the bias in the distance to the Virgo cluster raises this distance and lowers the calculated value of H0. Monte Carlo simulations of the cluster have been run for several possible distributions of spirals within the cluster and of clusters in the local universe. Simulations consistent with known information regarding the cluster and the errors of measurement result in a bias of about 6.5%-8.5%. This corresponds to an unbiased distance of 17.2-17.4 Mpc and a value of H0 in the range 80-82 km s-1 Mpc-1. The problem of determining the bias to Virgo illustrates several key points regarding Malmquist bias. Essentially all conventional astonomical distance measurements are subject to this bias. In addition, the bias accumulates when an attempt is made to construct "distance ladders" from measurements which are individually biased. As will be shown in the case of Virgo, the magnitude and direction of the bias are sensitive to the spatial distribution of the parent population from which the observed object is drawn—a distribution which is often poorly known. This leads to uncertainty in the magnitude of the bias, and adds to the importance of minimizing the number of steps in "distance ladders."
High frequency compensated current-mode ladder filters using multiple output OTAs

A methodology to implement compensated current-mode filters using multiple output OTAs and based on RLC ladder filter prototypes is presented. The resulting structures are very compact and share the low sensitivity characteristics of the passive RLC prototypes. They can be realized as CMOS circuits since they use only grounded capacitors and OTAs with one of the input terminals grounded. Compensation techniques to minimize degradation in the filter response due to excess phase of OTA parasitic poles are discussed. Simulations with CMOS OTAs and experimental results from discrete circuit implementations using bipolar OTAs are presented that verify the proposed approach. >
Gravity independent subcooled flow boiling heat transfer regime

Abstract Using an existing model for vapor bubble detachment, a subcooled flow boiling regime was identified where vapor bubble dynamics are independent of the gravitational field. The Jakob number and a dimensionless flow parameter were used to identify the boundaries of this regime. This work describes an experimental investigation of subcooled flow boiling heat transfer using FC-87 that was conducted with Jakob number ranging from 16–40, bulk flow velocity ranging from 0.39 to 1.17 m/s, and test section orientations of 0° horizontal flow, 45° upflow, 90° upflow, 315° downflow, and 270° downflow. The differences in the Nusselt number with different flow orientations are elucidated over the parameter space considered. Flow conditions where the heat transfer is independent of gravity have been identified and compared with the gravity dependent/independent regime map. It has been observed that at a particular Jakob number, the heat transfer is gravity independent at a lower bulk flow velocity than what is predicted by the theoretically based gravity dependent/independent regime map. Thus for design purposes, the regime map gives a conservative estimate for when the flow transitions into the gravity independent parameter space.
Autocratic, Democratic, And Optimal Government

All types of government face two major fiscal decisions: the level of government services and the average tax rate. This paper develops models of autocratic, democratic, and optimal government. The effects of alternative government structures are estimated using a common set of parameters based on US. data. Output and government services are higher in u democracy than in an autocracy, but the tax rate is lower. Output is even higher with an optimal government and both government services and the tax rate are lower. The relative outcomes in any government depend strongly on the fiscal horizon of those who govern. (JEL H11)
Coupled photonic crystal nanobeam cavities

We describe the design, fabrication, and spectroscopy of coupled, high quality (Q) factor silicon nanobeam photonic crystal cavities. We show that the single nanobeam cavity modes are coupled into even and odd superposition modes, and we simulate the frequency and Q factor as a function of nanobeam spacing, demonstrating that a differential wavelength shift of 70 nm between the two modes is possible while maintaining Q factors greater than 106. For both on substrate and freestanding nanobeams, we experimentally monitor the response of the even mode as the gap is varied, and measure Q factors as high as 2×105.
Low-Level Cloud Variability over the Equatorial Cold Tongue in Observations and Models

A fourth paper now in press is, Low-level cloud variability over the equatorial cold tongue in observations and models, by D. K. Mansbach and J. R. Norris (2007, J. Climate). This study examined cloud and meteorological observations from satellite, surface, and reanalysis datasets and fount that monthly anomalies in low-level cloud amount and near-surface temperature advection are strongly negatively correlated on the southern side of the equatorial Pacific cold tongue. This inverse correlation occurs independently of relationships between cloud amount and sea surface temperature (SST) or lower tropospheric static stability (LTS) and the combination of advection plus SST or LTS explains significantly more interannual cloud variability in a multilinear regression than does SST or LTS alone. Warm anomalous advection occurs when the equatorial cold tongue is well defined and the southeastern Pacific trade winds bring relatively warm air over colder water. Ship meteorological reports and soundings show that the atmospheric surface layer becomes stratified under these conditions, thus inhibiting the upward mixing of moisture needed to sustain cloudiness against subsidence and entrainment drying. Cold anomalous advection primarily occurs when the equatorial cold tongue is weak or absent and the air-sea temperature difference is substantially negative. These conditions favor a more convective atmospheric boundary layer, greater cloud amount, and less frequent occurrence of clear sky. Examination of output from global climate models developed by the Geophysical Fluid Dynamics Laboratory (GFDL) and the National Center for Atmospheric Research (NCAR) indicates that both models generally fail to simulate the cloud-advection relationships observed on the northern and southern sides of the equatorial cold tongue. Although the GFDL atmosphere model does reproduce the expected signs of cloud-advection correlations when forced with prescribed historical SST variations, it does not consistently do so when coupled to an ocean model. The NCAR model has difficulty reproducing the observed correlations in both atmosphere-only and coupled versions. This suggests that boundary layer cloud parameterizations could be improved through better representation of the effects of advection over varying SST.
The missing log in large deviations for triangle counts

This paper solves the problem of sharp large deviation estimates for the upper tail of the number of triangles in an Erdős-Renyi random graph, by establishing a logarithmic factor in the exponent that was missing till now. It is possible that the method of proof may extend to general subgraph counts. © 2011 Wiley Periodicals, Inc. Random Struct. Alg., 40, 437–451, 2012 © 2012 Wiley Periodicals, Inc.
Diagnosing Intrinsic Sphincteric Deficiency: Comparing Urethral Closure Pressure, Urethral Axis, and Valsalva Leak Point Pressures

OBJECTIVES: Our purpose was to compare three measures proposed to diagnose intrinsic sphincteric deficiency: maximum urethral closure pressure, Valsalva leak point pressure, and straining urethral axis. STUDY DESIGN: A total of 159 women with pure genuine stress incontinence had the three measures determined in a standardized fashion. Critical cutoff values for the Valsalva leak point pressure (52 cm) and urethral axis (22 degrees) were established by examining relative frequency distribution curves, using closure pressure of 20 as the arbitrary benchmark value for the prevalence of intrinsic sphincteric deficiency. The distribution of cutoff values is described and differences among the measures with respect to risk factors for intrinsic sphincteric deficiency and incontinence severity were determined. RESULTS: Half the subjects fell below at least one cutoff value, but only 10% fell below all three. Sixtyfour percent of subjects with either low closure pressure or leak point pressure had low values for the other, whereas 21% had discordance between them. Only 53% of subjects with low closure pressure and 40% with low leak point pressure had an axis -<22 degrees. Conversely, a substantial portion (36%) of subjects with pure genuine stress incontinence without urethral hypermobility had neither low urethral or leak point pressures. All three cutoff values were associated with risk factors for intrinsic sphincteric deficiency, but only low closure and leak point pressures had significant associations with the severity of incontinence. CONCLUSIONS: Intrinsic sphincteric deficiency should be diagnosed by a composite of historic, urodynamic, anatomic, and clinical severity criteria. We would include a maximum urethral closure pressure -<20, a Valsalva leak point pressure -<50, and a stress urethral axis -<20 in this composite. (Am J Obstet Gynecol 1997;177:303-10.)