cssi/SciSciGPT-SciSciNet huggingface dataset:
Pd-Catalyzed Aldehyde to Ester Conversion: A Hydrogen Transfer Approach

Aliphatic and aromatic aldehydes are successfully converted into their corresponding esters using Pd(OAc)2 and XPhos. This approach utilizes a hydrogen transfer protocol: concomitant reduction of acetone to isopropanol provides an inexpensive and sustainable approach that mitigates the need for other oxidants.
Unsteady transonic algorithm improvements for realistic aircraft applications

Improvements to a time-accurate approximate factorization (AF) algorithm have been implemented for steady and unsteady transonic analysis of realistic aircraft configurations. The algorithm improvements include: an Engquist-Osher (E-O) type-dependent switch to more accurately and efficiently treat regions of supersonic flow, extension of the E-O switch for second-order spatial accuracy in these regions, nonreflecting far field boundary conditions for more accurate unsteady applications, and several modifications which accelerate convergence to steady-state. Calculations are presented for several configurations to evaluate the algorithm modifications. The modifications have significantly improved the stability of the AF algorithm and hence the reliability of the CAP-TSD code in general.
Quantitative studies of elastin in the optic nerve heads of persons with primary open-angle glaucoma.

Purpose: To compare quantitative and qualitative differences in elastin content in the optic nerve heads of glaucomatous and control human eyes. Methods: Transmission electron microscopy and quantitative histomorphometry on ten control and ten glaucomatous eyes. Results: Elastin fiber complexes in the control lamina cribrosa were smaller and more numerous than in the insertion zone of the sclera immediately surrounding the lamina. Although the density of elastin fibers in the normal lamina was twice that of the insertion zone ( P = 0.004), the percent area of the connective tissue matrix occupied by elastin was the same for both zones ( P > 0.4). There was no difference between control and glaucomatous eyes in the quantified parameters of elastin content or in the ultrastructure of elastin between control and glaucomatous eyes. Conclusions: The authors demonstrated for the first time that elastin in the normal lamina consists of fibers of smaller diameter than in the adjacent sclera, although the total amount of elastin is similar in both locations. This may provide maximum viscoelasticity within the limited connective tissue beam area of the lamina. Despite using a large number of specimens, the authors again found no differences between normal and glaucomatous eyes in the number or ultrastructural appearance of elastin fibers.
Sedation and analgesia for brief diagnostic and therapeutic procedures in children

The number of diagnostic and therapeutic procedures done outside of the operating room and the intensive care unit has increased substantially in recent years. In parallel, the management of acute pain and anxiety in children undergoing therapeutic and diagnostic procedures has developed considerably in the past two decades. The primary goal of procedural sedation and analgesia is the safe and efficacious control of emotional distress and pain. The availability of non-invasive monitoring, short-acting opioids and sedatives has broadened the possibilities of sedation and analgesia in children in diverse settings. While most of these procedures themselves pose little risk to the child, the administration of sedation or analgesia may add substantial risk to the patient. This article reviews the current status of sedation and analgesia for invasive and non-invasive procedures in children providing an evidence-based approach to several topics of importance, including patient assessment, personnel requirements, equipment, monitoring, and drugs.
Using Web services to integrate heterogeneous simulations in a grid environment

The distributed information technologies collectively known as Web services recently have demonstrated powerful capabilities for scalable interoperation of heterogeneous software across a wide variety of networked platforms. This approach supports a rapid integration cycle and shows promise for ultimately supporting automatic composability of services using discovery via registries. This paper presents a rationale for extending Web services to distributed simulation environments, together with a description and examples of the integration methodology used to develop significant prototype implementations, and argues for combining the power of Grid computing with Web services to further expand this demanding computation and database access environment.
Collaborative Ontological Design of a Web Portal

The paper describes the collaborative development of an ontology for designing a web portal as part of a system development life cycle. Starting with the problem statement of the sponsors, the paper discusses the induction of the ontology from the requirements and the articulation of the ontology in wire frames for the system. Subsequently, the paper describes the multiple methods of external and internal validation of the ontology. The paper concludes with a discussion of future application of the ontology and recommendations for improvement. Thus it highlights the value of combining ontological analysis with the system development lifecycle (SDLC), conceptual modeling, and collaboration engineering.
Regioselectivity in palladium-catalyzed C-H activation/oxygenation reactions.

Palladium-catalyzed directed C−H activation/oxygenation reactions have been explored in a series of meta-substituted aryl pyridine and aryl amide derivatives. These transformations tolerate a diverse array of electron-donating and electron-withdrawing meta-substituents and generally proceed with high levels of regioselectivity for functionalization of the less sterically hindered ortho-C−H bond.
Convergences and divergences: anthropology and sociology in health care.

Abstract Historical and social influences have shaped medical sociology and medical anthropology in similar ways, yet have produced different emphases within these disciplines. Medical sociology, in particular, bears the imprint of sociology departments where most of its practitioners, scholars and teachers have been trained. Eight major substantive problems are noted as areas where the disciplines could profitably work together.
Robust gamma oscillations in networks of inhibitory hippocampal interneurons.

Recent experiments suggest that inhibitory networks of interneurons can synchronize the neuronal discharge in in vitro hippocampal slices. Subsequent theoretical work has shown that strong synchronization by mutual inhibition is only moderately robust against neuronal heterogeneities in the current drive, provided by activation of metabotropic glutamate receptors. In vivo neurons display greater variability in the interspike intervals due to the presence of synaptic noise. Noise and heterogeneity affect synchronization properties differently. In this paper we study, using model simulations, how robust synchronization can be in the presence of synaptic noise and neuronal heterogeneity. We find that stochastic weak synchronization (SWS) (i.e. when neurons spike within a short interval from each other, but not necessarily at each period) is produced with at least a minimum amount of noise and that it is much more robust than strong synchronization (i.e. when neurons spike at each period). The statistics prod...
Robert E. Holzer in celebration of his 80th birthday

On December 5, 1986, some of Robert E. Holzer's friends, colleagues, family, and former students gathered at the University of California, Los Angeles (UCLA), to celebrate his 80th birthday and to reminisce about events and experiences covering 5 decades of his career. Four speakers presented vignettes of their days with Holzer. Marx Brook (New Mexico Institute of Mining and Technology, Socorro) told of the early years in New Mexico. Stan Ruttenburg (University Corporation for Atmospheric Research, Boulder, Colo.) covered the move to California. Ed Smith (Jet Propulsion Laboratory, Pasadena, Calif.) recalled the early years in space research. And Jim Slavin (National Aeronautics and Space Administration (NASA) Goddard Space Flight Center, Greenbelt, Md.) described the postretirement years, when Bob became a very active researcher once again. To put the vignettes that follow in perspective, we briefly summarize Bob Holzer's career to date.
Entropic Elasticity of Lamellar Tethered Membrane Phases

Entropic elastic constants of lamellar tethered membrane phases are considered both in the vicinity of and at temperatures well below the membrane crumpling transition critical point. We calculate entropic forces acting on boundaries of these systems. Various predictions of the statistical physics of tethered membranes, such as the breakdown of the classical membrane elasticity theory at low temperatures or the existence of the crumpling transition, can be tested experimentally by using our results.
The Text and Cultural Politics

The school curriculum is not neutral knowledge. Rather, what counts as legitimate knowledge is the result of complex power relations, struggles, and compromises among identifiable class, race, gender, and religious groups. A good deal of conceptual and empirical progress has been made in the last 2 decades in answering the question of whose knowledge becomes socially legitimate in schools. Yet, little attention has actually been paid to that one arti-fact that plays such a major role in defining whose culture is taught–the textbook. In this article, I discuss ways of approaching texts as embodiments of a larger process of cultural politics. Analyses of them must focus on the complex power relationships involved in their production, contexts, use, and reading. I caution us against employing overly reductive kinds of perspectives and point to the importance of newer forms of textual analysis that stress the politics of how students actually create meanings around texts. Finally, I point to some of the impli...
Synthesis of a Model Compound of Corydendramine A via a Julia Coupling

The synthesis of the tetraenylpiperidine 12, which has the same core structure as the natural product corydendramine A, has been completed in eight steps starting from 2-piperidinemethanol 3 and trans,trans-2,6-nonadienal 6. The key step of the synthesis was a Julia coupling of sulfone (10) with aldehyde (5) to form a conjugated triene.
Bounds on the regularity and projective dimension of ideals associated to graphs

In this paper, we give new upper bounds on the regularity of edge ideals whose resolutions are k-step linear; surprisingly, the bounds are logarithmic in the number of variables. We also give various bounds for the projective dimension of such ideals, generalizing other recent results. By Alexander duality, our results also apply to unmixed square-free monomial ideals of codimension two. We also discuss and connect these results to more classical topics in commutative algebra.
A mild method for protodesilylation of α-dimethylphenylsilyl ester substrates

Mild conditions (1.2 eq. Hg(OAc)2, 1.2 eq. TBAF in 1:1 MeOH/THF; 35 min at 0 °C) have been developed for the protodesilylation of α-dimethylphenylsilyl esters. An enolate-dependent mechanism for the reaction was supported through studies indicating the clean incorporation of deuterium. To further investigate the mechanism, the optimal conditions as well as the kinetics of the reaction were explored.
Energy conservation and Onsager's conjecture for the Euler equations

Onsager conjectured that weak solutions of the Euler equations for incompressible fluids in conserve energy only if they have a certain minimal smoothness (of the order of 1/3 fractional derivatives) and that they dissipate energy if they are rougher. In this paper we prove that energy is conserved for velocities in the function space . We show that this space is sharp in a natural sense. We phrase the energy spectrum in terms of the Littlewood?Paley decomposition and show that the energy flux is controlled by local interactions. This locality is shown to hold also for the helicity flux; moreover, every weak solution of the Euler equations that belongs to conserves helicity. In contrast, in two dimensions, the strong locality of the enstrophy holds only in the ultraviolet range.
Master equation approach to spontaneous emission

A general theory for the treatment of spontaneous emission from a system of N identical two-level atoms or molecules is developed. The master equation for the reduced density operator of the atomic system alone is obtained and is used to derive an expression for the radiation rate. Both exact and approximate solutions are discussed.
New oligomeric catalyst for the hydrolytic kinetic resolution of terminal epoxides under solvent-free conditions

The solvent-free hydrolytic kinetic resolution of terminal epoxides catalyzed by a new oligomeric (salen)Co complex 2 is described. Extremely low loadings of catalyst were used to provide all epoxides examined in good yields and >99% ee under ambient conditions within 24 h.
Peculiar Hubble Flows in Our Local Universe

A formalism that simultaneously searches for monopolar and dipolar peculiar velocities is presented. The formalism is applied to (1) the Mark III Catalog of Galaxy Peculiar Velocities, (2) Lauer & Postman's Abell cluster catalog, and (3) Riess et al.'s Type Ia supernova sample. The emphasis is drawn to the monopolar peculiar velocities, i.e., peculiar Hubble flows, within these samples. The samples show inconsistent peculiar Hubble flows within a depth of ~60 h-1 Mpc. Beyond a depth of ~80 h-1 Mpc, the Hubble flows of all samples converge to the global Hubble flow to better than 10% at the 2 σ level. The results are compared with theoretical predictions. They at face value disfavor models that predict smaller peculiar velocities, such as the tilted cold dark matter model. Limitations of the catalogs are discussed, and so are ways to improve the catalogs so that an accurate map of Hubble flows in our local universe can be drawn and be compared with theoretical predictions.
Does Marginal Price Matter? A Regression Discontinuity Approach to Estimating Water Demand

Although complex pricing schedules are increasingly common in utility billing, it is difficult to determine whether consumers respond to complicated marginal prices because price changes are often confounded with simultaneous demand shocks or non-price policies. To overcome this challenge, we exploit a natural experiment - the introduction of a third price block in an increasing block pricing schedule for water - in Santa Cruz, California. Using a regression discontinuity design, we find that consumers do respond to changes in marginal price. Doubling marginal price led to a 12% decrease in water use (500 cubic feet per bill) among high-use households.
Participation of Immunoglobulin and the Alternative Complement Pathway in Opsonization of Bacteroides fragilis and Bacteroides thetaiotaomicron

Studies were conducted to determine the requirements for immunoglobulin and complement for opsonization of Bacteroides fragilis and Bacteroides thetaiotaomicron. The ability of human sera depleted of immunoglobulin or complement components to promote phagocytosis and intracellular killing of the strains of Bacteroides by human leukocytes was measured in vitro under anaerobic conditions. Neither hypogammaglobulinemic sera nor pooled normal human serum (PNHS) heated at 56 C for 30 min supported phagocytosis and killing of the strains of Bacteroides. Sera depleted of terminal complement components by treatment with inulin or cobra venom factor and C8-deficient human serum did not support phagocytosis of the test strains. PNHS depleted of C3, factor B, or factor D also did not support phagocytosis of either strain. Dose-dependent restoration of the opsonic activity of factor B-depleted serum was accomplished by purified human factor B but not by human C2. The results indicated that immunoglobulin and components of the alternative complement pathway participate in opsonization of the strains of Bacteroides tested in this study.
Electron thermochemical nonequilibrium effects in re-entry boundary layers

Results of calculated nonequilibrium electron temperature and concentration characteristics in boundary layers are presented for re-entry conditions: Um = 27,500-34,000 fps and altitude 110,000-150,000 ft. These results show the effects of reactions, collisions, electrical current, and electron reflection on the electron heat transfer and temperature. The electron conservation equations in boundary-layer form were solved in the quasi-neutral region with collisionless sheath boundary conditions or approximate boundary conditions derived from the collisionless sheath expressions and valid with collisions in the sheath. A numerical solution was obtained by a finite difference technique after a similarity transformation arid quasilinearization of the equations. The solutions show significant temperature nonequilibrium. Electron current and reflection, combined into a single parameter, reduces electron temperature and increases conduction of energy but does not explicitly affect electron concentration or diffusion of ionization energy.
Optimal Inverse Littlewood-Offord theorems

Abstract Let η i , i = 1 , … , n , be iid Bernoulli random variables, taking values ±1 with probability 1 2 . Given a multiset V of n integers v 1 , … , v n , we define the concentration probability as ρ ( V ) : = sup x P ( v 1 η 1 + ⋯ + v n η n = x ) . A classical result of Littlewood–Offord and Erdős from the 1940s asserts that, if the v i are non-zero, then ρ ( V ) is O ( n − 1 / 2 ) . Since then, many researchers have obtained improved bounds by assuming various extra restrictions on V. About 5 years ago, motivated by problems concerning random matrices, Tao and Vu introduced the inverse Littlewood–Offord problem. In the inverse problem, one would like to characterize the set V, given that ρ ( V ) is relatively large. In this paper, we introduce a new method to attack the inverse problem. As an application, we strengthen the previous result of Tao and Vu, obtaining an optimal characterization for V. This immediately implies several classical theorems, such as those of Sarkozy and Szemeredi and Halasz. The method also applies to the continuous setting and leads to a simple proof for the β-net theorem of Tao and Vu, which plays a key role in their recent studies of random matrices. All results extend to the general case when V is a subset of an abelian torsion-free group, and η i are independent variables satisfying some weak conditions.
The Organometallic Chemistry of Carbon Dioxide.

The possibility of recycling CO{sub 2} from industrial emissions and of removing some of this greenhouse gas, an environmental pollutant, is receiving increased attention. Also, the possibility of using CO{sub 2} as the starting material for the synthesis of fine chemicals provides an attractive alternative to compounds presently derived from petroleum. Efforts to convert CO{sub 2} to useful chemicals will inevitably center on transition metal catalysts. Furthermore, efforts to enhance the yield of hydrogen in water gas shift reactions are also centered on carbon dioxide interactions with transition metal catalysts. For all these reasons, a broader understanding of the organometallic chemistry of CO{sub 2} is being sought. In this article, only those compounds that can be clearly identified as having carbon dioxide bound to metal centers through carbon will be considered. Thus the discussions will not include metal formate complexes whose chemistry has been reviewed recently. Also, the discussions will not include metallocarboxylic acids or metallocarboxylate esters except where these compounds have been used as reagents for the synthesis of CO{sub 2} complexes or result from reactions of these compounds. 111 refs.
Enantioselective Synthesis of Pactamycin, a Complex Antitumor Antibiotic

Medicinal application of many complex natural products is precluded by the impracticality of their chemical synthesis. Pactamycin, the most structurally intricate aminocyclopentitol antibiotic, displays potent antiproliferative properties across multiple phylogenetic domains, but it is highly cytotoxic. A limited number of analogs produced by genetic engineering technologies show reduced cytotoxicity against mammalian cells, renewing promise for therapeutic applications. For decades, an efficient synthesis of pactamycin amenable to analog derivatizations has eluded researchers. Here, we present a short asymmetric total synthesis of pactamycin. An enantioselective Mannich reaction and symmetry-breaking reduction sequence was designed to enable assembly of the entire carbon core skeleton in under five steps and control critical three-dimensional (stereochemical) functional group relationships. This modular route totals 15 steps and is immediately amenable for structural analog synthesis.
Quality Assurance of U.S. Geological Survey Water-Quality Field Measurements

Each year many thousands of water-quality measurements are made in the field by personnel of the US Geological Survey's Water Resources Division. To insure the accuracy of these measurements, an external quality assurance program was officially established in March 1979. The initial phase of this program was concerned with specific conductance and pH measurements. Reference samples are submitted semiannually to field analysts for measurement of these parameters with the same techniques and instruments used in the field. Both the personnel and the instruments involved in making the determinations are recorded. When the data are complete, a report defining the quality of the analytical results is prepared and circulated to appropriate District, Regional, and National offices. Field data, in addition to their immediate use, are normally placed in a national data base and are available to all hydrologists. As a result, the quality of field measurements can have a profound effect on their investigations. The quality assurance program described is designed to insure that the field data of the Water Resources Division are highly accurate. 1 figure, 4 tables.
Relativistic Self-similar Disks

We formulate and solve by semianalytic means the axisymmetric equilibria of relativistic self-similar disks of infinitesimal vertical thickness. These disks are supported in the horizontal directions against their self-gravity by a combination of isothermal (two-dimensional) pressure and a flat rotation curve. The dragging of inertial frames restricts possible solutions to rotation speeds that are always less than 0.438 times the speed of light, a result first obtained by Lynden-Bell & Pineault in 1978 for a cold disk. We show that prograde circular orbits of massive test particles exist and are stable for all of our model disks but that retrograde circular orbits cannot be maintained with particle velocities less than the speed of light once the disk develops an ergoregion. We also compute photon trajectories, planar and nonplanar, in the resulting spacetime for disks with and without ergoregions. We find that all photon orbits, except for a set of measure zero, tend to be focused by the gravity of the flattened mass-energy distribution toward the plane of the disk. This result suggests that strongly relativistic, rapidly rotating, compact objects may have difficulty ejecting collimated beams of matter or light along the rotation axes until the flows get well beyond the flattened parts of the relativistic mass distribution (which cannot happen in the self-similar models considered in this paper).
A Note on Lower Bounds Estimates for the Neumann Eigenvalues of Manifolds with Positive Ricci Curvature

We study new heat kernel estimates for the Neumann heat kernel on a compact manifold with positive Ricci curvature and convex boundary. As a consequence, we obtain lower bounds for the Neumann eigenvalues which are consistent with Weyl’s asymptotics.
Tidal dissipation and the strength of the Earth’s internal magnetic field

Magnetic fields at the Earth's surface represent only a fraction of the field inside the core. The strength and structure of the internal field are poorly known, yet the details are important for our understanding of the geodynamo. Here I obtain an indirect estimate for the field strength from measurements of tidal dissipation. Tidally driven flow in the Earth's liquid core develops internal shear layers, which distort the internal magnetic field and generate electric currents. Ohmic losses damp the tidal motions and produce detectable signatures in the Earth's nutations. Previously reported evidence of anomalous dissipation in nutations can be explained with a core-averaged field of 2.5 mT, eliminating the need for high fluid viscosity or a stronger magnetic field at the inner-core boundary. Estimates for the internal field constrain the power required for the geodynamo.
How large is the Government Spending Multiplier? Evidence from World Bank Lending

This paper proposes a novel method of isolating fluctuations in public spending that are likely to be uncorrelated with contemporaneous macroeconomic shocks and can be used to estimate government spending multipliers. The approach relies on two features unique to many low-income countries: (1) borrowing from the World Bank finances a substantial fraction of public spending, and (2) actual spending on World Bank-financed projects is typically spread out over several years following the original approval of the project. These two features imply that fluctuations in spending on World Bank projects in a given year are in large part determined by fluctuations in project approval decisions made in previous years, and so are unlikely to be correlated with shocks to output in the current year. World Bank project-level disbursement data are used to isolate the component of public spending associated with project approvals from previous years, which in turn can be used to estimate government spending multipliers, in a sample of 29 aid-dependent low-income countries. The estimated multipliers are small, reasonably precisely estimated, and rarely significantly different from zero.
Universal relations for the strongly-interacting Fermi gas

Shina Tan has derived some universal relations that hold for any state of a system consisting of fermions with two spin states that have a large scattering length. These relations involve an intensive quantity called the contact that measures the number of pairs of atoms that are very close together. We show how these relations can be derived in the framework of quantum field theory using standard renormalization methods and the operator product expansion. They allow the contact density to be identified as the expectation value of a local operator constructed out of quantum fields.
Advances in gamma-ray line astronomy

Gamma ray line observations of solar flares, gamma ray transients, and the galactic center are reviewed and interpreted. Prospects of future line detections are discussed.
CHIRAL BIS(OXAZOLINE)COPPER(II) COMPLEXES AS LEWIS ACID CATALYSTS FOR THE ENANTIOSELECTIVE DIELS-ALDER REACTION

Bis(oxazoline)copper(II) complexes are highly enantioselective catalysts in Diels−Alder reactions involving bidentate dienophiles. Cationic [Cu((S,S)-t-Bu-box)]X2 complexes with different counterions have been used as catalysts, revealing a profound influence of the counterion on the rate and stereoselectivity of the catalyst. A square-planar catalyst−substrate complex is proposed to account for the high diastereo- and enantioselectivities observed. Three bis(oxazoline)−Cu(II) X-ray structures have been obtained that support this model. Double-stereodifferentiating experiments, performed employing chiral dienophiles, afforded results that are fully consistent with the proposed square-planar transition-state assemblage. In addition to imide-based substrates, α,β-unsaturated thiazolidine-2-thiones have been introduced as a new class of dienophiles with enhanced reactivity. Kinetics experiments were performed to quantify the role that product inhibition plays in the course of the reaction. Rate and equilibri...
The Future of Indirect Evidence

Familiar statistical tests and estimates are obtained by the direct observation of cases of interest: a clinical trial of a new drug, for instance, will compare the drug’s effects on a relevant set of patients and controls. Sometimes, though, indirect evidence may be temptingly available, perhaps the results of previous trials on closely related drugs. Very roughly speaking, the difference between direct and indirect statistical evidence marks the boundary between frequentist and Bayesian thinking. Twentieth-century statistical practice focused heavily on direct evidence, on the grounds of superior objectivity. Now, however, new scientific devices such as microarrays routinely produce enormous data sets involving thousands of related situations, where indirect evidence seems too important to ignore. Empirical Bayes methodology offers an attractive direct/indirect compromise. There is already some evidence of a shift toward a less rigid standard of statistical objectivity that allows better use of indirect evidence. This article is basically the text of a recent talk featuring some examples from current practice, with a little bit of futuristic speculation.
Sentence paraphrasing from a conceptual base

A model of natural language generation based on an underlying language-free representation of meaning is described. A program based on this model is able to produce sentence paraphrases which demonstrate understanding with respect to a given context. This generator operates in conjunction with a natural language analyzer and a combined memory and inference model. In generating sentences from meaning structures, the program employs both the information retrieval and deduction capabilities of the memory model.The model encompasses several diverse classes of linguistic knowledge, which include: (1) executable tests of conceptual properties stored in discrimination nets; (2) information relating conceptual to syntactic roles, stored in a word-sense dictionary, and (3) surface grammatical knowledge, stored in a formal grammar.
Influence of the continuous and dispersed phases on the symmetry of a gas turbine air-blast atomizer

Current trends in liquid-fueled practical combustion systems are leaving less tolerance for fuel injection deficiencies such as poor spray field symmetry. The present paper evaluates the symmetry of the flowfield produced by a practical airblast atomizer. Specifically, the influence of both the continuous phase and dispersed phase on the spray field symmetry is assessed. In the present case, asymmetry in volume flux is associated principally with disparities in the injection of the dispersed phase, which is manifested by a maldistribution of larger drops. Asymmetries observed in the continuous phase without the dispersed phase are reduced in magnitude by the presence of the dispersed phase, but still contribute to asymmetry in radial spread of the dispersed phase.
ON LOCALITY OF DOMINATING SET IN AD HOC NETWORKS WITH SWITCH-ON/OFF OPERATIONS

Efficient routing among a set of mobile hosts is one of the most important functions in ad hoc wireless networks. Routing based on a connected dominating set is a promising approach, where the search space for a route is reduced to the hosts in the set. A set is dominating if all the hosts in the system are either in the system are either in the set or neighbors of hosts in the set. In this paper, we first review a distributed formation of a connected dominating set called marking process and dominating-set-based routing. Then we propose several ways to reduce the size of the dominating set and study the locality of dominating set and study the locality of dominating set in ad hoc wireless networks with switch-on/off operations. Results show that the dominating set derived from the marking process exhibits good locality properties; i.e., the change of a host status, gateway (dominating) or non-gateway (dominated), affects only the status of hosts in a restricted vicinity. In addition, locality of host status updated is also verified through simulation.
Measurements of scalar power spectra in high Schmidt number turbulent jets

Single-point, jet-fluid concentration measurements obtained from high Schmidt number (Sc ≃ 1.9 x 10^3) turbulent jets permit an investigation of temporal scalar power spectra, for jet Reynolds numbers in the range of 1.25 ≤ Re x 10^(-4)≤ 7.2. At intermediate scales, we find a spectrum with a logarithmic derivative (slope) that is increasing with Reynolds number, in absolute value, but less than 5/3 at the highest Reynolds number in our experiments. At the smallest scales, our spectra exhibit no k^(-1) power-law behavior, possessing a log-normal region over a range of scales exceeding a factor of 40, in some cases.
Nonlinear microrheology of wormlike micelle solutions using ferromagnetic nanowire probes.

Ferromagnetic nanowires were employed to investigate the microrheology of wormlike micelle solutions composed of equimolar cetylpyridinium chloride--sodium salicylate. For a wire rotated about a short axis, the drag at low rotation rate ${\ensuremath{\omega}}_{R}$ is independent of ${\ensuremath{\omega}}_{R}$ and strongly temperature dependent, consistent with the macroscopic shear viscosity. Above a critical rotation rate ${\ensuremath{\omega}}_{c}$, the drag is independent of temperature and decreases as a power law with increasing rate. The onset of nonlinear drag is characterized by a peak associated with contributions from extensional flow. Above ${\ensuremath{\omega}}_{c}$, the fluid generates an additional torque that tilts the wire out of regions of high shear flow and that is interpreted as a consequence of a shear-induced transition to nematic order among the micelles. Rotation of the wire in response to this torque reveals directly the anisotropy of the drag in the nonlinear state.
Electronic correlations and midgap absorption in polyacetylene

Electronic correlations are important when they lift degeneracies of Huckel models. Standard Pariser–Parr–Pople (PPP) parameters split the degenerate midgap absorption of neutral solitons in undoped trans polyacetylene (CH)x. The dipole intensity goes entirely to the upper state close to the optical gap Eg. PPP correlations lower slightly the nondegenerate transition at Eg/2 of charged solitons, which consequently provide all the E∼Eg/2 intensity. Exact symmetries of correlated states and finite‐chain computations are exploited in associating the midgap absorption of neat and lightly doped (CH)x entirely with charged solitons.
Witten's SU(2) anomaly on the lattice

Abstract Witten's anomaly for SU (2) with a single I= 1 2 Weyl fermion in four dimension is shown to be reproduced by the lattice overlap. The mechanism is based on Berry's phase, and on the analyticity of the matrix H by which the overlap is defined.
Gender differences in Type 1 credit rationing of small businesses in the US

AbstractThis paper explores Type 1 credit rationing by gender using data from the 1998 and 2003 Survey of Small Business Finances (SSBF). Type 1 credit rationing occurs when borrowers receive a smaller loan than they requested. We use two measures of Type 1 credit rationing to examine whether it is related to gender discrimination in lending. Our results show that women business owners are not likely to be Type 1 rationed. However, newer female-owned firms receive significantly lower loan amounts than requested compared to their male-owned counterparts. We also find that less experienced women receive significantly lower loan amounts compared to less experienced men.
Nucleophilic Di- and Tetrafluorination of Dicarbonyl Compounds

Reactions of various diketo compounds with Deoxofluor [(CH3OCH2CH2)2NSF3] have been investigated. When reacted with Deoxofluor, α-diketones, R1COCOR2 (R1 = R2 = Ph; R1 = R2 = 4-Me-C6H4; R1 = Ph, R2 = Me; R1 = Me, R2 = Et) (1a−d) formed difluoro derivatives (2a−d) in the presence of a catalytic amount of HF and/or tetrafluoro (3a−d) products depending on the reaction conditions and stoichiometry used. Reactions of β-diketones, R3COCH2COR4 (R3 = R4 = Ph; R3 = R4 = Me; R3 = Me, R4 = Ph) (4e−g), with Deoxofluor in the presence of a catalytic amount of HF led to the formation of difluoroalkenones as a mixture of E (5e−g) and Z (6e−g) isomers in good yield. Reaction of other diones, R5CO-X-COR6 (R5 = R6 = Ph, X = −CHCH−; R5 = R6 = Me, X = −C6H4C6H4−; R5 = R6 = Ph, X = −CH2CH2CH2−; R5 = R6 = Me, X = −CH2CH2−) (7h−k) with Deoxofluor produced mainly difluoro products (8h−k) with low yields of tertrafluoro derivatives (9h−k). Acyclic α-keto amides react poorly to give the corresponding difluoro derivatives, whereas...
Auto-tuning unit norm frames

Abstract Finite unit norm tight frames provide Parseval-like decompositions of vectors in terms of redundant components of equal weight. They are known to be robust against additive noise and erasures, and as such, have great potential as encoding schemes. Unfortunately, up to this point, these frames have proven notoriously difficult to construct. Indeed, though the set of all unit norm tight frames, modulo rotations, is known to contain manifolds of nontrivial dimension, we have but a small finite number of known constructions of such frames. In this paper, we present a new iterative algorithm—gradient descent of the frame potential—for increasing the degree of tightness of any finite unit norm frame. The algorithm itself is easy to implement, and it preserves certain group structures present in the initial frame. In the special case where the number of frame elements is relatively prime to the dimension of the underlying space, we show that this algorithm converges to a unit norm tight frame at a linear rate, provided the initial unit norm frame is already sufficiently close to being tight. By slightly modifying this approach, we get a similar, but weaker, result in the non-relatively-prime case, providing an explicit answer to the Paulsen problem: “How close is a frame which is almost tight and almost unit norm to some unit norm tight frame?”
Exchange rate dynamics in a multilateral target zone.

This paper presents a model of exchange rate behaviour in a multilateral target zone. The model produces new economic insights beyond the well-known bilateral model of Krugman (1991), which is obtained as a special case. The paper also introduces a new class of stochastic processes in economics, namely multidimensional reflected diffusion processes. Two main features characterize the economics of exchange rates in a multilateral target zone. (i) The restrictions on interventions imposed by cross-currency constraints: when one country changes its money supply, say because its exchange rate with a second country has hit its band, all exchange rates involving the currency of that particular country will be affected, regardless of their position within their respective bands, (ii) Cooperation in sharing the intervention burden: in general, the exchange rate between any two countries will depend on the fundamentals of third countries in a multilateral target zone. This is because if the monetary authorities intervene together, a shock in the fundamentals of any country will induce a revision of the expectation of future interventions of other countries. The model reverts the counterfactual predictions of the bilateral model that the exchange rate steady-state density should be U-shaped and that its volatility should be a decreasing function of the distance of the exchange rate to the limits of its band. Thus, accounting for the multilateral feature of real-world target zones allows us to reconcile target zone models with the most salient empirical features of exchange rate behaviour.
A Freestream-Preserving High-Order Finite-Volume Method for Mapped Grids with Adaptive-Mesh Refinement

A fourth-order accurate finite-volume method is presented for solving time-dependent hyperbolic systems of conservation laws on mapped grids that are adaptively refined in space and time. Novel considerations for formulating the semi-discrete system of equations in computational space combined with detailed mechanisms for accommodating the adapting grids ensure that conservation is maintained and that the divergence of a constant vector field is always zero (freestream-preservation property). Advancement in time is achieved with a fourth-order Runge-Kutta method.
Correspondence principle for a brane in Minkowski space and vector mesons

We consider a 3-brane in D-dimensional Minkowski space and discuss a correspondence principle analogous to the AdS/CFT correspondence. For a 3-brane of finite thickness in the transverse directions, we obtain a spectrum for vector gravitational perturbations which correspond to vector mesons. The spectrum agrees with the one obtained in truncated AdS space by de Teramond and Brodsky provided D = 10 and the bulk mass scale M is of order the geometric mean of the Planck mass () on the brane and ΛQCD (M ~ (ΛQCD)1/2 ~ 109 GeV).
Family Firm Resource Management: Commentary and Extensions

The family firm resource–divestment model by Sharma and Manikutty (2004) is extended into a longitudinal model of family firm resource management. Resource accumulation is included as an additional...
Synthesis of a Photoreactive Taxol Side Chain

Abstract The photoreactive taxol side chain, (2 R ,3 S )-(−)-N-(4′-azido-benzoyl-3-phenylisoserine methyl ester ( 6 ), was prepared in four steps from (2 R ,3 R )-(+)-methyl 3-phenylglycidate ( 2 ).
Borel-Cantelli sequences

A sequence {x n } 1 ∞ in the unit interval [0, 1) = ℝ/ℤ is called Borel-Cantelli, or BC, if for all non-increasing sequences of positive real numbers {a n } with 48001013 1. $$\sum\nolimits_{i = 1}^\infty {} {a_i} = \infty $$ , the set $$\{ x \in [0,1)\left| {\left| {x - {x_n}} \right|} \right. < {a_n}{\rm{for infinitely many }}n \ge 1\} $$ has full Lebesgue measure. (Speaking informally, BC sequences are sequences for which a natural converse to the Borel-Cantelli Theorem holds). The notion of BC sequences is motivated by the monotone shrinking target property for dynamical systems, but our approach is from a geometric rather than dynamical perspective. A sufficient condition, a necessary condition and a necessary and sufficient condition for a sequence to be BC are established. A number of examples of BC sequences and sequences that are not BC are also presented. The property of a sequence to be BC is a delicate Diophantine property. For example, the orbits of a pseudo-Anosoff IET (interval exchange transformation) are BC, while the orbits of a “generic” IET are not. The notion of BC sequences is extended from [0, 1) to sequences in Ahlfors regular spaces.
Covariance calculation for floating-point state-space realizations

This paper provides a new method for analyzing floating-point roundoff error for digital filters by using "finite signal-to-noise" models whose noise sources have variances proportional to the variance or power of the corrupted signals. With this model, a new expression for output error covariance of floating-point arithmetic is derived the in case of double or extended precision accumulation. The output error covariance shows that the optimal state space realization for floating point is the same as that of the fixed-point case, except for two cases: when the filter has poles extremely close to the unit circle or when final quantization to precisions shorter than single precision is employed. An explicit formula is found for determining the minimum number of mantissa bits for stable realization.
A conformally invariant holographic two-point function on the Berger sphere

We apply our previous work on Green's functions for the four-dimensional quaternionic Taub-NUT manifold to obtain a scalar two-point function on the homogeneously squashed three-sphere (otherwise known as the Berger sphere), which lies at its conformal infinity. Using basic notions from conformal geometry and the theory of boundary value problems, in particular the Dirichlet-to-Robin operator, we establish that our two-point correlation function is conformally invariant and corresponds to a boundary operator of conformal dimension one. It is plausible that the methods we use could have more general applications in an AdS/CFT context.
POWER SPECTRUM SENSITIVITY AND THE DESIGN OF EPOCH OF REIONIZATION OBSERVATORIES

Recent theoretical developments for observing the epoch of reionization (EOR) have concentrated on the power spectrum signature of redshifted 21 cm emission. These studies have demonstrated the great potential of statistical EOR observations; however, the sensitivity calculations for proposed low-frequency radio arrays have been highly approximate. The formalism developed for interferometric measurements of the cosmic microwave background can be extended to three dimensions to naturally incorporate the line-of-sight information inherent in the EOR signal. In this paper we demonstrate how to accurately calculate the EOR power spectrum sensitivity of an array and develop scaling relationships that can be used to guide the design of EOR observatories. The implications for antenna distribution, antenna size, and correlator requirements on the EOR sensitivity are detailed.
Continued Radio Monitoring of the Gamma-Ray Burst 991208

We present radio observations of the afterglow of the bright γ-ray burst GRB 991208 at frequencies of 1.4, 4.9, and 8.5 GHz, taken between two weeks and 300 days after the burst. The well-sampled radio light curve at 8.5 GHz shows that the flux density peaked about 10 days after the burst and decayed thereafter as a power law FR ∝ t-1.07±0.09. This decay rate is more shallow than the optical afterglow of GRB 991208 with F0 ∝ t-2.2, which was measured during the first week. These late-time data are combined with extensive optical, millimeter, and centimeter measurements and fitted to the standard relativistic blast wave model. In agreement with previous findings, we find that an isotropic explosion in a constant-density or wind-blown medium cannot explain these broadband data without modifying the assumption of a single power-law slope for the electron energy distribution. A jetlike expansion provides a reasonable fit to the data. In this case, the flatter radio light curve compared to the optical may be due to emission from an underlying host galaxy, or due to the blast wave making a transition to nonrelativistic expansion. The model that best represents the data is a free-form model in which it is assumed that the broadband emission originates from a synchrotron spectrum, while the time evolution of the break frequencies and peak flux density are solved for explicitly. Although the decay indices for most of the synchrotron parameters are similar to those for the jet model, the evolution of the cooling break is unusually rapid (νc ∝ t-2) and therefore requires some nonstandard evolution in the shock.
The Pitfalls of Subsystem Integration: When Less Is More

In various industries end-product manufacturers acquire core subsystems from upstream technology provider firms and focus primarily on efficient end-product integration. We examine the strategic interactions between a technology firm that introduces a new subsystem and the respective end-product manufacturers “integrators”. We analyze how the fraction of end-product functionalities prepackaged into the subsystem impacts the optimal introduction strategy and the relative value appropriation power across the industries. Offering a subsystem that performs many end-product functions has a dual effect on the provider's profits. On the positive side, the provider extracts a higher ease-of-use rent from the integrators because of the easier/cheaper integration. On the negative side, such subsystems may curtail the adopters' ability for competitive differentiation and render adoption less valuable. We discuss the role of subsystem functionality in value appropriation in technology markets, and we highlight the perils of subsystem overintegration. This paper was accepted by Kamalini Ramdas, entrepreneurship and innovation.