cssi/SciSciGPT-SciSciNet huggingface dataset:
Efficient spectroscopy of single embedded emitters using optical fiber taper waveguides.

A technique based on using optical fiber taper waveguides for probing single emitters embedded in thin dielectric membranes is assessed through numerical simulations. For an appropriate membrane geometry, photoluminescence collection efficiencies in excess of 10 % are predicted, exceeding the efficiency of standard free-space collection by an order of magnitude. Our results indicate that these fiber taper waveguides offer excellent prospects for performing efficient spectroscopy of single emitters embedded in thin films, such as a single self-assembled quantum dot in a semiconductor membrane.
A Core Curriculum for Medical Students in Clinical Pharmacology and Therapeutics

The Council for Medical Student Education in Clinical Pharmacology and Therapeutics organized a workshop for faculty members who were interested in improving instruction in the area of clinical pharmacology in their own medical schools. The workshop was designed with three objectives in mind: 1) to introduce participants to political problems and practical solutions to curriculum change; 2) to help participants formulate an essential core curriculum for clinical pharmacology instruction; and 3) to encourage participants to consider educational problems that hinder appropriate teaching of clinical pharmacology, and begin to develop practical solutions to these problems
Toward a global magnetospheric equilibrium model

[1] In this paper we take a first step toward the development of a realistic global magnetospheric model in which the magnetic forces are equilibrated by plasma pressure forces. Such a model describes a “quasi-static” equilibrium, a condition valid at most times in the Earth's magnetosphere. The work reported here involves the coupling in two dimensions of a numerical inner/middle magnetosphere model in flux coordinates, which solves the Grad-Shafranov equation in “inverse” form, with an asymptotic magnetotail model farther away from Earth. We discuss the obtained configurations (including the resulting magnetic fields and electric currents) under different observation-based inputs (parameters include plasma and total pressures, as well as the magnetic flux boundary). In particular, we focus on the boundary value problem, in which we take realistic shapes for the outer magnetic flux surface (close to the magnetopause) and plasma pressure distributions as model inputs and obtain the total pressure variation in the tail as a by-product of the model.
The Gamma Ray Pulsar Population

We apply a likelihood analysis to pulsar detections, pulsar upper limits, and diffuse background measurements from the OSSE and EGRET instruments on the Compton Gamma Ray Observatory to constrain the luminosity law for gamma-ray pulsars and some properties of the gamma-ray pulsar population. We find that the dependence of luminosity on spin period and dipole magnetic field is much steeper at OSSE than at EGRET energies (50-200 keV and >100 MeV, respectively), suggesting that different emission mechanisms are responsible for low- and high-energy gamma-ray emission. Incorporating a spin-down model and assuming a pulsar spatial distribution, we estimate the fraction of the Galactic gamma-ray background due to unidentified pulsars and find that pulsars may be an important component of the OSSE diffuse flux but are most likely not important at EGRET energies. Using measurements of the diffuse background flux from these instruments, we are able to place constraints on the braking index, initial spin period, and magnetic field of the Galactic pulsar population and are also able to constrain the pulsar birthrate to be between 1/25 yr-1 and 1/500 yr-1. Our results are based on a large gamma-ray beam, but they do not scale in a simple way with beam size. We estimate that about 20 of the 169 unidentified EGRET sources are probably gamma-ray pulsars. We use our model to predict the pulsar population that will be seen by future gamma-ray instruments and estimate that Gamma Ray Large Area Space Telescope will detect roughly 750 gamma-ray pulsars as steady sources, only 120 of which are currently known radio pulsars.
Computation of mini-jet inclusive cross sections☆

Abstract We apply the theory of parton-parton total cross sections at large s , due to Lipatov and collaborators, to compute the inclusive cross section for jets which accompany a large s parton scattering process.
Proof-carrying code

This paper describes proof-carrying code (PCC), a mechanism by which a host system can determine with certainty that it is safe to execute a program supplied (possibly in binary form) by an untrusted source. For this to be possible, the untrusted code producer must supply with the code a safety proof that attests to the code's adherence to a previously defined safety policy. The host can then easily and quickly validate the proof without using cryptography and without consulting any external agents.In order to gain preliminary experience with PCC, we have performed several case studies. We show in this paper how proof-carrying code might be used to develop safe assembly-language extensions of ML programs. In the context of this case study, we present and prove the adequacy of concrete representations for the safety policy, the safety proofs, and the proof validation. Finally, we briefly discuss how we use proof-carrying code to develop network packet filters that are faster than similar filters developed using other techniques and are formally guaranteed to be safe with respect to a given operating system safety policy.
Stability of a rigid rotor supported on flexible oil journal bearings

This investigation deals with the stability characteristics of oil journal bearings, including the effect of elastic distortions in the bearing liner. Graphical results are presented for (1) steady-state load, (2) stiffness and damping coefficients, and (3) the stability. These results are given for various slenderness ratios, eccentricity ratios, and elasticity parameters. The lubricant is first assumed to be isoviscous. The analysis is then extended to the case of a pressure-dependent viscosity. It has been found that stability decreases with increase of the elasticity parameter of the bearing liner for heavily loaded bearings.
On geometric entropy

Abstract We show that a geometrical notion of entropy, definable in flat space, governs the first quantum correction to the Bekenstein-Hawking black hole entropy. We describe two methods for calculating this entropy - a straightforward Hamiltonian approach, and a less direct but more powerful Euclidean (heat kernel) method. The entropy diverges in quantum field theory in the absence of an ultraviolet cutoff. Various related finite quantities can be extracted with further work. We briefly discuss the corresponding question in string theory.
Using stochastic acceleration to place experimental limits on the charge of antihydrogen

Assuming hydrogen is charge neutral, CPT invariance demands that antihydrogen also be charge neutral. Quantum anomaly cancellation also demands that antihydrogen be charge neutral. Standard techniques based on measurements of macroscopic quantities of atoms cannot be used to measure the charge of antihydrogen. In this paper, we describe how the application of randomly oscillating electric fields to a sample of trapped antihydrogen atoms, a form of stochastic acceleration, can be used to place experimental limits on this charge.
Organocatalytic Enantioselective Synthesis of α-Hydroxy Phosphonates

Tertiary alpha-hydroxy phosphonates have been synthesized in good yields and high enantiomeric purity (up to 99% ee) through a novel l-proline-catalyzed cross aldol reaction of alpha-keto phosphonates and ketones.
The Urban Atmosphere as a Non-Point Source for the Transport of MTBE and Other Volatile Organic Compounds (VOCs) to Shallow Groundwater

Infiltration and dispersion (including molecular diffusion) can transport volatile organic compounds (VOCs) from urban air into shallow groundwater. The gasoline additive methyl-tert-butyl ether (MTBE) is of special interest because of its (1) current levels in some urban air, (2) strong partitioning from air into water, (3) resistance to degradation, (4) use as an octane-booster since the 1970s, (5) rapidly increasing use in the 1990s to reduce CO and O3 in urban air, and (6) its frequent detection at low microgram per liter levels in shallow urban groundwater in Denver, New England, and elsewhere. Numerical simulations were conducted using a 1-D model domain set in medium sand (depth to water table = 5 m) to provide a test of whether MTBE and other atmospheric VOCs could move to shallow groundwater within the 10−15 y time frame over which MTBE has now been used in large amounts. Degradation and sorption were assumed negligible. In case 1 (no infiltration, steady atmospheric source), 10 y was not long en...
Optical-phonon modes in a double heterostructure of polar crystals

The equation of motion for the polarization vector for a double heterostructure of polar crystals is solved exactly within the framework of the continuum model. There exist only two types of phonon modes, the interface modes and the confined bulk modes, whose eigenvectors are obtained explicitly. Dispersion relations are derived analytically for the interface modes, while the confined bulk modes are dispersionless, a fact consistent with the model. It is also found that in Raman scattering experiments the symmetric interface modes are predominantly longitudinal optical (LO) and the antisymmetric interface modes transverse optical (TO). In the central region of the Brillouin zone, however, they both split into two branches oscillating at LO and TO frequencies, respectively. Possible reinterpretation of various experiments is briefly discussed.
CATALYTIC ASYMMETRIC AMINOHYDROXYLATION WITH AMINO-SUBSTITUTED HETEROCYCLES AS NITROGEN SOURCES

The suprafacial, vicinal addition of a heterocyclic moiety and a hydroxyl group is achieved by the osmium-catalyzed asymmetric aminohydroxylation (AA) of olefins with amino-substituted heterocycles as the nitrogen sources. Amino alcohols are obtained in up to 97 % yield and with up to 99 % ee when a ligand derived from dihydroquinidine (DHQD-L) is used [Eq. (1); R(i) indicates the remaining portion of the heterocycle (Het); H2 O is the O source]. The AA can now be considered as a means to directly introduce complex, biologically relevant substructures to hydrocarbon backbones.
Using Experimental Asset Markets to Illustrate the Value of Auditing

This article provides a description of (and guidance for implementing) a classroom exercise in which experimental asset markets are used to illustrate the economic impact that auditing can have on a market economy and its participants. In particular, the exercise entails creating two actual microeconomies in the classroom. In one microeconomy, participants produce, trade, and consume generic assets in an environment in which the underlying asset quality is not readily observable to consumers. In the second microeconomy, there is one principal difference: asset quality is verified via an independent audit, and the results are reported to the marketplace. Comparison of the two microeconomies allows students and instructors to identify, measure, and explain the impact of auditing on individual decisions, individual profits, and overall market performance. The exercise can serve as a platform for classroom discussion on a variety of topics pertaining to the value of auditing in a market economy. As such, the ...
Stereoselective Construction of Functionalized, Trisubstituted (Z)-Allylsilanes and (Z)-Iodoalkenes

Methodology for the stereoselective construction of functionalized, trisubstituted (Z)-allylsilanes and (Z)-iodoalkenes has been developed.
SOD1G93A transgenic mouse CD4+ T cells mediate neuroprotection after facial nerve axotomy when removed from a suppressive peripheral microenvironment

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease involving motoneuron (MN) axonal withdrawal and cell death. Previously, we established that facial MN (FMN) survival levels in the SOD1(G93A) transgenic mouse model of ALS are reduced and nerve regeneration is delayed, similar to immunodeficient RAG2(-/-) mice, after facial nerve axotomy. The objective of this study was to examine the functionality of SOD1(G93A) splenic microenvironment, focusing on CD4(+) T cells, with regard to defects in immune-mediated neuroprotection of injured MN. We utilized the RAG2(-/-) and SOD1(G93A) mouse models, along with the facial nerve axotomy paradigm and a variety of cellular adoptive transfers, to assess immune-mediated neuroprotection of FMN survival levels. We determined that adoptively transferred SOD1(G93A) unfractionated splenocytes into RAG2(-/-) mice were unable to support FMN survival after axotomy, but that adoptive transfer of isolated SOD1(G93A) CD4(+) T cells could. Although WT unfractionated splenocytes adoptively transferred into SOD1(G93A) mice were able to maintain FMN survival levels, WT CD4(+) T cells alone could not. Importantly, these results suggest that SOD1(G93A) CD4(+) T cells retain neuroprotective functionality when removed from a dysfunctional SOD1(G93A) peripheral splenic microenvironment. These results also indicate that the SOD1(G93A) central nervous system microenvironment is able to re-activate CD4(+) T cells for immune-mediated neuroprotection when a permissive peripheral microenvironment exists. We hypothesize that a suppressive SOD1(G93A) peripheral splenic microenvironment may compromise neuroprotective CD4(+) T cell activation and/or differentiation, which, in turn, results in impaired immune-mediated neuroprotection for MN survival after peripheral axotomy in SOD1(G93A) mice.
Digital voice processing with a wave function representation of speech

Digital voice processing has advanced to a relatively high level of sophistication due to the development of the fast Fourier transform (FFT) algorithm. Complete vocoder systems have been developed around the FFT and with the advent of high-speed integrated circuits and read-only memories to implement sine and cosine tables for the FFT, actual real-time hardware processing has been accomplished.
Improving the Asmussen-Kroese Type Simulation Estimators

Author(s): Ghamami, Samim; Ross, Sheldon M. | Abstract: Asmussen-Kroese [1] Monte Carlo estimators of P(Sn g u) and P(SN g u) are known to work well in rare event settings when Sn is the sum of n i.i.d. heavy-tailed random variables, and N is a non-negative integer-valued random variable independent of the Xi. In this paper we show how to improve the Asmussen-Kroese estimators of both probabilities when the Xi are non-negative. We also apply our ideas to estimate the quantity E[(SN ? u)+].
An efficient route to functionalized dienes for decalin synthesis

Abstract Reaction of the trimethylsilyl (TMS) enol ethers 6 derived from the conjugate addition of organo-copper reagents to 3,4-dimethylcyclopentenone with dimethyl dioxirane (DMDO) leads to α-hydroxy ketones 7 with predominantly the syn -methyl orientation. Exposure of these systems to methanolic lead tetraacetate (Pb(OAc) 4 ) delivers aldehydic esters 8 which are homologated to the desired E -dienes 9 using Yamamoto's allylic phosphine oxide reagent.
Information theoretic bounds for low-rank matrix completion

This paper studies the low-rank matrix completion problem from an information theoretic perspective. The completion problem is rephrased as a communication problem of an (uncoded) low-rank matrix source over an erasure channel. The paper then uses achievability and converse arguments to present order-wise optimal bounds for the completion problem.
Oppolzer-Type Intramolecular Diels–Alder Cycloadditions via Isomerizations of Allenamides

A new approach to Oppolzer’s intramolecular Diels–Alder cycloaddition (IMDA) through γ-isomerization of readily available N-tethered allenamides is described. These IMDA reactions are carried out in tandem with the allenamide isomerization or 1,3-H shift, leading to complex nitrogen heterocycles in a highly stereoselective manner.
AN OOSTERHOFF ANALYSIS OF THE GALACTIC BULGE FIELD RR LYRAE STARS: IMPLICATIONS ON THEIR ABSOLUTE MAGNITUDES

We present an analysis of the period-V-amplitude plane for RR0 Lyrae stars (fundamental mode pulsators) with 'normal' light curves in the bulge using the MACHO bulge fields. Although bulge globular clusters (GCs) have RR Lyraes that divide into two reasonable distinct groups according to the average period of the RR0 Lyraes, there is no evidence of a gap between Oosterhoff I (OoI) and II (OoII) stars in the bulge field star sample. The majority of the bulge RR0 Lyrae field star population have a difference in period compared to the OoI cluster M3 ({delta}log P) that is shifted by about 0.02 days with regard to the Milky Way OoI population, and the sample includes stars with {delta}log P > 0.06 days, a characteristic hardly seen in Milky Way GCs. The metal-rich RR0 Lyrae stars in the Galactic bulge sample have {delta}log P values on the other side of the spectrum as those in the metal-rich GCs NGC 6388 and NGC 6441. We find that the V amplitude for a given period is a function of {delta}log P, and not of metal abundance, similar to the result found by Clement and Shelton for RR Lyrae stars in Milky Way GCs. Amore » comparative study of the bulge field stars with similar metallicities but different Oosterhoff types is carried out. Bulge field RR0 Lyrae variables with {delta}log P values similar to OoII clusters are about 0.2 mag brighter than RR0 Lyrae variables with {delta}log P similar to OoI clusters. Reliance upon a single M {sup RR} {sub V}-[Fe/H] relation may be inappropriate when considering populations with different {delta}log P.« less
Measuring absolute branching ratios of charmed baryons in B decays

The B factories are expected to provide huge samples of single B decay events with little background by reconstructing one of the B mesons produced in $\Upsilon (4S)$ decays. This represents a new experimental paradigm: such samples will allow to make measurements of a quality previously thought unrealistic. As example we discuss how absolute branching ratios for exclusive as well as inclusive charm baryon decays can be extracted. One starts out by observing decays like $B^- \to \bar p X$ as a signature for $B^- \to \Lambda _c \bar p X$ etc. and then exploits various correlations of the flavour of the B meson with the baryon number of the (anti)proton and other observables like the charge of a lepton, baryon number of another baryon etc. An integrated luminosity of about 500 fb-1 as could be available by 2005 should be sufficient for the task.
Multicointegration analysis of the sustainability of foreign debt

Using the multicointegration framework suggested by Granger and Lee, 1989 , Granger and Lee, 1990 and developed in Engsted, Gonzalo and Haldrup (1997) and Haldrup (1997) this study explores the long-run relationship between components of the U.S. current account during two periods 1947:i–1973:iv and 1974:i–1994:ii. The paper develops the concept of sustainability of external imbalances in an environment that is non-deterministic and characterized by uncertainty. The sustainability criteria are related to multicointegration. Evidence consistent with sustainable intertemporal external budgeting in the fixed exchange rate era is presented. In the post Bretton Woods period there is no support for sustainable external budgeting. Policy issues and factors that affect sustainability are discussed.
Predicted oxidation of CO catalyzed by Au nanoclusters on a thin defect-free MgO film supported on a Mo(100) surface.

With the use of first-principles simulations, low barrier CO oxidation reactions are predicted to occur via a Langmuir−Hinshelwood or an Eley−Rideal mechanism, on two-dimensional gold nanocluster islands adsorbed on two-layer MgO films that are supported on Mo(100). Underlying the emergent catalytic activity, predicted to occur even in the absence of oxygen vacancy F-center defects, is the excess electronic charge at the gold cluster/magnesia interface originating from the penetration of metal states through the thin magnesia film. This excess charge stabilizes the planar structure of the gold cluster and activates the oxygen molecules adsorbed at the interfacial periphery of the gold islands.
Micro-Foundations of Firm-Specific Human Capital: When Do Employees Perceive Their Skills to be Firm-Specific?

Drawing on human capital theory, strategy scholars have emphasized firm-specific human capital as a source of sustained competitive advantage. In this study, we begin to unpack the micro-foundation...
Coupled Electromagnetic–Thermal Analysis of Electric Machines Including Transient Operation Based on Finite-Element Techniques

Since the mass and volume of electric machines are heavily dependent on their thermal constraints, it is important to find ways to analyze and simultaneously optimize their electromagnetic (EM) and thermal performances. This paper presents an approach for coupling the finite-element EM and thermal analyses of electrical machines using temperature-dependent material properties, so that temperatures inside a candidate machine can be predicted simultaneously with its EM performance. In addition to steady-state conditions, the coupled analysis has been extended in this paper to transient operation for machines that are required to deliver high torque/power for short intervals. Three 30-kW 10-pole 12-slot surface permanent magnet machines optimized for maximum torque density, minimum cost, and maximum efficiency, respectively, have been investigated. This coupled EM–thermal analysis makes it easier for designers to maximize the winding current density to achieve the highest possible torque/power ratings within thermal limits set by the winding insulation or demagnetization limits.
A model of learning and emulation with artificial adaptive agents

We study adaptive learning in a sequence of overlapping generations economies in which agents live for n periods. Agents initially have heterogeneous beliefs, and form multi-step-ahead forecasts using a forecast rule chosen from a vast set of candidate rules. Agents learn in every period by creating new forecast rules and by emulating the forecast rules of other agents. Computational experiments show that systems so defined can yield three qualitatively different types of long-run outcomes: (1) coordination on a low inflation, stationary perfect foresight equilibrium; (2) persistent currency collapse; and (3) coordination failure within the allotted time frame.
Fluid-induced propulsion of rigid particles in wormlike micellar solutions

In the absence of inertia, a reciprocal swimmer achieves no net motion in a viscous Newtonian fluid. Here, using tracking methods and birefringence imaging, we investigate the ability of a reciprocally actuated particle to translate through a complex fluid that possesses a network. A geometrically polar particle, a rod with a bead on one end, is reciprocally rotated using magnetic fields. The particle is immersed in a wormlike micellar (WLM) solution that is known to be susceptible to the formation of shear bands and other localized structures due to shear-induced remodeling of its microstructure. Results show that the nonlinearities present in this WLM solution break time-reversal symmetry under certain conditions, and enable propulsion of an artificial “swimmer.” We find three regimes dependent on the Deborah number (De): net motion towards the bead-end of the particle at low De, net motion towards the rod-end of the particle at intermediate De, and no appreciable propulsion at high De. At low De, where the particle time scale is longer than the fluid relaxation time, we believe that propulsion is caused by an imbalance in the fluid first normal stress differences between the two ends of the particle (bead and rod). At De ∼ 1, however, we observe the emergence of a region of network anisotropy near the rod using birefringence imaging. This anisotropy suggests alignment of the micellar network, which is “locked in” due to the shorter time scale of the particle relative to the fluid.
One-Dimensional Silicon/PLZT Spatial Light Modulators

One-dimensional, optically addressed silicon/PLZT spatial light modulators (SLMs) have been fabricated and tested. A study of theoretical and measured performance, design configurations, and functional flexibility leads to the conclusion that 1-D silicon/PLZT SLMs will find application in optical linear algebra processors, neural network systems, and multiplex holography.
Theoretical implications of the combined solar neutrino observations

Abstract Constraints on the core temperature of the Sun and on neutrino-oscillation parameters are obtained by comparing the combined Homestake, Kamiokande, SAGE and GALLEX solar neutrino data with Standard Solar Models (SSM) and with non-standard solar models parameterized by a phenomenological central temperature (Tc). If the Sun is 2% cooler of 3% warmer than predicted by SSMs, the MSW parameters we determine are consistent with different grand unified theories.
Project DARE: Differential Analyzer REplacement by on-line digital simulation

While batch-processed applications of convenient, highly developed digital continuous-system simulation languages are now commonplace, such systems do not provide the intimate man-machine intercourse cherished in analog/hybrid simulation. The DES-I system, which combined a special simulation console and a digital plotter with an SDS 9300 (medium-sized) computer was, then, a pioneering effort, unfortunately abandoned by its manufacturer. The only commercially available interactive system appears to be the IBM CSMP 1130 system which, like its predecessor PACTOLUS, can be programmed from a simple typewriter terminal. This is an interpreter system implemented on a small computer and thus yields relatively quite slow execution.
Climate change and water desalination in MENA — World Bank involvement

This paper presents the water sector challenges and the expected impact due to climate change in the Middle East and North Africa (MENA) region. The World Bank and other international funding agencies recognized the already existing water crisis in many places around the world. As an outcome to an integrated water resources management there will be a need for proper supply and demand management. However, the enhancement of the existing water resources via wastewater reuse and brackish and seawater desalination is eminent. It will be even applied at a larger scale when the adverse effect of the climate change on water resources will be considered. The World Bank is allocating billions of dollars to mitigate for the climate change and reduce the global warming effects via the improvement in the energy efficiency, energy conservation and enhancement of renewable energy resources. Some mechanisms where established that the water resources enhancement can benefit from. These include the Clean Development Mecha...
On the interpretation of Chinese loess as a paleoclimate indicator

The records of wind-blown dust (i.e., loess) in China are some of the most important terrestrial records of past climate changes, stretching back over the last 10 Ma. In the paleoclimate literature, intervals of increased dust generation have been almost always interpreted as being associated with more intense or prolonged wintertime conditions. Here it is shown that, in accordance with modern observations, dust outbreaks in Asia are predominantly springtime phenomena. During spring, frequent cyclogenesis in the lee of the Mongolian Altai and the passage of strong cold fronts produce the intense windstorms that loft and entrain dust into the air. The meteorology governing such outbreaks is likely robust in past climates. Contrary to the common paleoclimate presumption, it is actually the breakdown of the Siberian High that permits the dust-producing windstorms to occur. The importance of cold fronts in generating such windstorms suggests that cooling of high-latitude climate during the Miocene, or during glacial intervals, might play a significant role in the signal recorded in the loess deposits. The unique springtime factors that generate dust storms are an example of why the common partitioning of Asian climate into a ‘winter’ and ‘summer’ monsoon is oversimplified and can be misleading.
Quantum aspects of massive gravity

We consider the effect of quantum interactions on Pauli–Fierz massive gravity. With generic graviton cubic interactions, we observe that the 1-loop counterterms do not conform to the tree level structure of Pauli–Fierz action, resulting in the reappearance of the sixth mode ghost. Then to explore the quantum effects to the full extent, we calculate the resummed graviton propagator with an arbitrary interaction and analyze its complete structure, from which a minimal condition for the absence of the ghost is obtained.
Parenting Practices of Resident Fathers: The Role of Marital and Biological Ties

This paper uses data from the Fragile Families and Child Wellbeing Study (N ¼ 2,098) to examine differences in the parenting practices of four types of resident fathers, defined by their biological relationship to a focal child and their marital status with regard to the focal child’s mother. Regression results suggest that biological fathers and social fathers (i.e., stepfathers or mothers’ cohabiting partners) differ significantly, and in some unexpected ways, on most measures of parenting. A considerable portion of these differences, however, can be explained by variation in the background characteristics of the individuals and families in each group. Additionally, difference-in-difference analyses reveal a stronger link between marriage and higher quality parenting practices among social fathers than among biological fathers.
A fast algorithm for approximating the ground state energy on a quantum computer

Estimating the ground state energy of a multiparticle system with relative error " using deterministic classical algorithms has cost that grows exponentially with the number of particles. The problem depends on a number of state variablesd that is proportional to the number of particles and suers from the curse of dimensionality. Quantum computers can vanquish this curse. In particular, we study a ground state eigenvalue problem and exhibit a quantum algorithm that achieves relative error " using a number of qubits C 0 d log" 1 with total cost (number of queries plus other quantum operations) Cd" (3+ ) , where > 0 is arbitrarily small and C and C 0 are inde
The Capacity Region of the MIMO Interference Channel and Its Reciprocity to Within a Constant Gap

The capacity region of the two-user multi-input multioutput (MIMO) Gaussian interference channel (IC) is characterized to within a constant gap that is independent of the channel matrices for the general case of the MIMO IC with an arbitrary number of antennas at each node. An achievable rate region and an outer bound to the capacity region of a class of interference channels were obtained in previous work by Telatar and Tse as unions over all possible input distributions. In contrast to that previous work on the MIMO IC, a simple and an explicit achievable coding scheme are obtained here and shown to have the constantgap-to-capacity property and in which the sub-rates of the common and private messages of each user are explicitly specified for each achievable rate pair. The constant-gap-to-capacity results are thus proved in this work by first establishing explicit upper and lower bounds to the capacity region. A reciprocity result is also proved which is that the capacity of the reciprocal MIMO IC is within a constant gap of the capacity region of the forward MIMO IC.
Analytic solutions to the ignition kinetics of the hydrogen-oxygen reaction.

Solutions have been obtained assuming isothermal conditions and negligible depletion of reactants during the induction period for the following scheme of reactions: O H + H 2 → k 1 H 2 O + H , H + O 2 → k 2 O H + O , O + H 2 → k 3 O H + H , H + O 2 + M → k 6 H O 2 + M , H O + H 2 → k 11 H 2 O 2 + H Three types of solutions have been deduced, corresponding to k 6 c M >2 k 2 (a low-temperature-high-pressure region of long ignition delays), 2 k 2 > k 6 c M (a high-temperature-low-pressure region of short delays), and 2 k 2 = k 6 c M (the boundary between the two regions). Experimental ignition delays in both long- and short-delay regions are adequately explained, and ignition delays computed by numerical integration of the rate equations are reproduced to within a few per cent. Finally, ignition delays for the Von Neumann spike condition in Chapman-Jouguet detonations in the neighborhood of the lean limit of detonability in air have been calculated. These delays decrease by two orders of magnitude as the hydrogen mole fraction increases from 0.135 to 0.145. This is very close to the experimental limit (hydrogen mole fraction 0.14 to 0.15) and thus supports the notion that the condition 2 k 2 > k 6 C M must be satisfied for a stable detonation.
The Preparation of 4,5-Dihydro-5-Phenyl-5-(2-Phenylethenyl)Isoxazoles, 4,5-Dihydro-5-Methyl-5-(2-Phenylethenyl)Isoxazoles, or 4,5-Dihydro-5,5-DI-(2-Phenylethenyl)Isoxazoles from Dilithiated C(α),O-Oximes and Select α,β–-Unsaturated Ketones

Abstract C(α),O-oximes were dilithiated with lithium diisopropylamide and condensed with three α,β-unsaturated ketones: (2E)-1,3-diphenyl-2-propen-1-one, or (1E, 4E)-1,5-diphenyl-1,4-pentadien-3-one, or (3E)-4-phenyl-3-buten-2-one, followed by immediate acid cyclization to variously substituted 4,5-dihydroisoxazoles: 4,5-dihydro-5-phenyl-5-(2-phenylethenyl)isoxazoles, 4,5-dihydro-5-methyl-5-(2-phenylethenyl)isoxazoles, or 4,5-dihydro-5,5-di-(2-phenylethenyl)-isoxazoles.
Three-Dimensional Profiling with the Sandia Nuclear Microprobe

A nuclear microprobe analysis system attached to Sandia's EN tandem Van de Graaff accelerator is described. A magnetic quadrupole doublet lens is used for the final focus and 2 ?m beam diameters have been obtained. Several illustrative applications of the microprobe, including the first three-dimensional concentration profiles using Rutherford backscattering and elastic recoil detection ever measured, are given.
Thermal management of integrated microsensors

Abstract Thermal modeling techniques are demonstrated as they apply to a generic integrated microsensor with a heat source located on an anisotropically etched silicon diaphragm. One- and two-dimensional conduction formulas, boundary-layer convective heat transfer, a method of images approach for chip-level conduction, and the finite-element method are discussed, with examples, as they apply to the generic microsensor.
Analytic Sensitivities and Approximations in Supersonic and Subsonic Wing/Control Surface Unsteady Aerodynamics

Development of efe cient, design-oriented analysis techniques and associated approximations for wing/ control surface unsteady aerodynamics is crucial to the success of any multidisciplinary aeroservoelastic optimization of airplanes including active control technology. A design-oriented capability for unsteady supersonic aerodynamics for planar wing/control surface cone gurations is presented here. Explicit expressions for aerodynamic ine uence coefe cients make it possible to efe ciently obtain analytic sensitivities of generalized aerodynamic loads with respect to planform shape. Examination of the mathematical structure of the discretization used, similar to other aerodynamic panel methods, reveals sources of discontinuity of derivatives with respect to shape in the supersonic case. Sources of nonsmooth behavior of the unsteady aerodynamic loads in subsonic e ow are identie ed and eliminated. The accuracy and computational cost of alternative approximation techniques are studied. A second-order approximation technique based on the direct and adjoint solutions at a reference cone guration is presented. Experience and insight are gained in the area of design-oriented and approximate unsteady aerodynamics, to be used in the nonlinear programming/approximation concepts approach to engineering optimization.
Unstable optical resonators

This paper reviews the current level of theoretical understanding and experimental confirmation of the properties of unstable optical resonators for laser oscillators. A primary conclusion is that for any laser system characterized by a moderate gain per pass and a Fresnel number greater than a few times unity the unstable resonator provides the best practical resonator design for obtaining a high-quality near-diffraction-limited output laser beam combined with efficient energy extraction from the laser medium.
Growth of attached actin filaments.

In several studies of actin-based cellular motility, the barbed ends of actin filaments have been observed to be attached to moving obstacles. Filament growth in the presence of such filament-obstacle interactions is studied via Brownian dynamics simulations of a three-dimensional energy-based model. We find that with a binding energy greater than 24kBT and a highly directional force field, a single actin filament is able to push a small obstacle for over a second at a speed of half of the free filament elongation rate. These results are consistent with experimental observations of plastic beads in cell extracts. Calculations of an external force acting on a single-filament-pushed obstacle show that for typical in vitro free-actin concentrations, a 3pN pulling force maximizes the obstacle speed, while a 4pN pushing force almost stops the obstacle. Extension of the model to treat beads propelled by many filaments suggests that most of the propulsive force could be generated by attached filaments.
Bath salts intoxication: a case series.

Abstract Background Bath salts commonly contain multiple synthetic drugs, and their toxic effects are largely the same as those seen in patients who have taken large doses of amphetamines. Bath salts can be ingested, smoked, or administered intravenously. Their use is on the rise and is responsible for a large number of emergency department visits. Case Report Our case series involved five patients (six hospital courses) who presented after ingesting bath salts. The presentations involved signs and symptoms of intense sympathetic response. All patients had a history of drug abuse, and most had psychiatric disorders as well. Treatments included benzodiazepines, mechanical ventilation, and intravenous hydration. Conclusion Bath salts are available for approximately $20 (USD) in packets at truck stops and on the Internet, usually marketed with the disclaimer, “not for human consumption.” Their presentation mimics other sympathetic drugs and causes a significant amount of delirium, hallucinogenic-delusional symptoms, extreme agitation, combativeness, and rhabdomyolysis, often leading to hospitalizations and intensive care unit (ICU) stays. Management is largely supportive and includes aggressive intravenous hydration, dampening of the excessive sympathetic outflow with benzodiazepines, and close monitoring in the ICU setting. The U.S. Drug Enforcement Administration (DEA) recently invoked its emergency scheduling authority to control these synthetic stimulants. The DEA plans to make possessing and selling these chemicals, or products that contain them, illegal in the United States
The singularities of the wave trace of the basic Laplacian of a Riemannian foliation

Abstract We apply techniques of microlocal analysis to the study of the transverse geometry of Riemannian foliations in order to analyze spectral invariants of the basic Laplacian acting on functions on a Riemannian foliation with a bundle-like metric. In particular, we consider the trace of the basic wave operator when the mean curvature form is basic. We extend the concept of basic functions to distributions and demonstrate the existence of the basic wave kernel. The singularities of the trace of this basic wave kernel occur at the lengths of certain geodesic arcs which are orthogonal to the closures of the leaves of the foliation. In cases when the foliation has regular closure, a complete representation of the trace of the basic wave kernel can be computed for t ≠ 0 . Otherwise, a partial trace formula over a certain set of lengths of well-behaved geodesic arcs is obtained.
Deflection Measurements with Weak Values

We report an interferometric weak-value technique to amplify transverse beam deflections. The utility is quantified through an investigation of the signal to noise ratio along with the experimental results.
A Search for Lyman Break Galaxies at z > 8 in the NICMOS Parallel Imaging Survey

We have selected 14 J-dropout Lyman break galaxy (LBG) candidates with J110 - H160 ≥ 2.5 from the NICMOS Parallel Imaging Survey. This survey consists of 135 arcmin2 of imaging in 228 independent sight lines, reaching average 5 σ sensitivities of J110 = 25.8 and H160 = 25.6 (AB). Distinguishing these candidates from dust-reddened star-forming galaxies at z ~ 2-3 is difficult and will require longer wavelength observations. We consider the likelihood that any J-dropout LBGs exist in this survey and find that if L is significantly brighter than L (a factor of 4), then a few J-dropout LBGs are likely. A similar increase in luminosity has been suggested by Eyles et al. and Yan et al., but the magnitude of this increase is uncertain.
Re-preparing the secondary physics teacher

Adequate preparation of secondary physics teachers is vital to ensuring good teaching of physics in schools. This US case study describes an on-going program involving close collaboration between university science and education departments and also involving local schools. A new project, PhysTEC, will extend these ideas nationwide.
The impact of biofuels policy on agribusiness stock prices

Corn markets are important for many industries, including the seed, fertilizer, meat production/processing, and agricultural machinery sectors, all of which are highly concentrated. Oligopoly theory suggests that corn input and field equipment suppliers likely benefit from policies that support corn markets, such as U.S. biofuels policy, whereas meat companies likely lose. This study investigates the impact of biofuels policy on U.S. agribusiness stock prices. Corn futures prices are found to have had a structural change in November 2006, consistent with the expansion of U.S. biofuels policy support. A linear two-factor (SP L13; Q14]. © 2010 Wiley Periodicals, Inc.
Analysis of energy spectra with low photon counts via Bayesian posterior simulation

Over the past 10 years Bayesian methods have rapidly grown more popular in many scientific disciplines as several computationally intensive statistical algorithms have become feasible with increased computer power. In this paper we begin with a general description of the Bayesian paradigm for statistical inference and the various state-of-the-art model-fitting techniques that we employ (e.g., the Gibbs sampler and the Metropolis-Hastings algorithm). These algorithms are very flexible and can be used to fit models that account for the highly hierarchical structure inherent in the collection of high-quality spectra and thus can keep pace with the accelerating progress of new space telescope designs. The methods we develop, which will soon be available in the Chandra Interactive Analysis of Observations (CIAO) software, explicitly model photon arrivals as a Poisson process and thus have no difficulty with high-resolution low-count X-ray and γ-ray data. We expect these methods to be useful not only for the recently launched Chandra X-Ray Observatory and XMM but also for new generation telescopes such as Constellation X, GLAST, etc. In the context of two examples (quasar S5 0014+813 and hybrid-chromosphere supergiant star α TrA), we illustrate a new highly structured model and how Bayesian posterior sampling can be used to compute estimates, error bars, and credible intervals for the various model parameters. Application of our method to the high-energy tail of the ASCA spectrum of α TrA confirms that even at a quiescent state, the coronal plasma on this hybrid-chromosphere star is indeed at high temperatures (>10 MK) that normally characterize flaring plasma on the Sun. We are also able to constrain the coronal metallicity and find that although it is subject to large uncertainties, it is consistent with the photospheric measurements.
Input DNA Ratio Determines Copy Number of The 33 kb Factor IX Gene on De Novo Human Artificial Chromosomes

Human artificial chromosomes (ACs) are non-integrating vectors that may be useful for gene therapy. They assemble in cultured cells following transfection of human centromeric α -satellite DNA and segregate efficiently alongside the host genome. In the present study, a 33 kilobase (kb) Factor IX (FIX) gene was incorporated into mitotically stable ACs in human HT1080 lung derived cells using co-transfection of a bacterial artificial chromosome (BAC) harboring synthetic α -satellite DNA and a P1 artificial chromosome(PAC) that spans the FIX locus. ACs were detected in ≥90% of chromosome spreads in 8 of 19 lines expanded from drug resistant colonies. FIX transgene copy number on ACs was determined by input DNA transfection ratios. Furthermore, a low level of FIX transcription was detected from ACs with multiple transgenes but not from those incorporating a single transgene, suggesting that reducing transgene number may limit misexpression. Their potential to segregate cross species was measured by transferring ACs into mouse and hamster cell lines using microcell-mediated chromosome transfer. Lines were obtained where ACs segregated efficiently. The stable segregation of ACs in rodent cells suggests that it should be possible to develop animal models to test the capacity of ACs to rescue FIX deficiency.
Comparison of Free Radical Generation by Pre- and Post-Sintered Cemented Carbide Particles

Rapid generation of reactive oxygen species (ROS) may occur in response to cellular contact with metal particles. Generation of ROS by cobalt and/or tungsten carbide is implicated in causing hard metal lung disease (HMD) and allergic contact dermatitis (ACD). In this study, ROS generation and particle properties that influence radical generation were assessed for three sizes of tungsten, tungsten carbide, cobalt, admixture (tungsten carbide and cobalt powders), spray dryer, and post-sintered chamfer grinder powders using chemical (H2O2 plus phosphate buffered saline, artificial lung surfactant, or artificial sweat) and cellular (RAW 264.7 mouse peritoneal monocytes plus artificial lung surfactant) reaction systems. For a given material, on a mass basis, hydroxyl (·OH) generation generally increased as particle size decreased; however, on a surface area basis, radical generation levels were more, but not completely, similar. Chamfer grinder powder, polycrystalline aggregates of tungsten carbide in a metall...
Products of nearly holomorphic eigenforms

We prove that the product of two nearly holomorphic Hecke eigenforms is again a Hecke eigenform for only finitely many choices of factors.
Application of composite materials for fabrication of spacecraft communication antennas

Abstract The mechanical design of five different spacecraft communication antennas built of graphite-epoxy and Kevlar-epoxy materials is described. These antennas include straight and folded horns and large (3.7 m diameter) and small (0.3 m diameter) paraboloidal reflectors. To perform successfully during launch and on-orbit, space antennas must be strong, stiff, and lightweight with small thermal distortions. The graphite and Kevlar materials have attractive mechanical properties for this application. Their properties are reviewed and compared with competitive materials. Careful design and analysis procedures are required to make effective use of composite materials. This is illustrated by five hardware antenna examples.