cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermospheric neutral density response to solar forcing

Abstract Recent measurements by the Solar EUV (Extreme Ultra Violet) Experiment (SEE) aboard the Thermosphere–Ionosphere–Mesosphere Energetics and Dynamics satellite (TIMED) provide solar EUV spectral irradiance with adequate spectral and temporal resolution, and thus the opportunity to use solar measurements directly in upper atmospheric general circulation models. Thermospheric neutral density is simulated with the NCAR Thermosphere–Ionosphere–Electrodynamic General Circulation Model (TIEGCM) using TIMED/SEE measurements and using the EUVAC solar proxy model. Neutral density is also calculated using the NRLMSISE-00 empirical model. These modeled densities are then compared to density measurements derived from satellite drag data. It is found that using measured solar irradiance in the general circulation model can improve density calculations compared to using the solar proxy model. It is also found that the general circulation model can improve upon the empirical model in simulating geomagnetic storm effects and the solar cycle variation of neutral density.
Reduction of Sodium Cyclotriphosphate by Metallic Molybdenum

The products of the reaction between sodium cyclotriphosphate and powder Mo in vacuum at temperatures up to 1000‡C were characterized by x-ray diffraction and31P nuclear magnetic resonance. Above 650–700‡C, the reaction yields MoP and amorphous sodium phosphates (orthophosphate, pyrophosphate, and cyclotetraphosphate) containing Mo in the oxidation state 5+. At the Mo content ensuring the largest percentage of sodium cyclotetraphosphate in the reaction products, these also contain a small amount of elemental phosphorus.
Control Authority of a Projectile Equipped with a Controllable Internal Translating Mass

control authority requirements. The work reported here considers a vibrating internal mass control mechanism applicableto both fin-and spin-stabilized configurations.To investigate the potential of this control mechanism, a7degree-of-freedom flight dynamic model of a projectile equipped with an internal translating mass is generated. By vibrating the internal translating mass normal to the axis of symmetry and at the roll rate frequency, significant control authority can be attained with a relatively small internal mass on the order of a percent or so of the total projectile mass. Interestingly, control authority increases proportionally with increasing roll rate and also with increasing station-line cavity offset from the mass center. Trajectory changes are not caused by lateral mass center offset and drag but rather by dynamic coupling between internal mass vibration and the projectile body. Nomenclature AT = internal translating mass oscillation amplitude aC=I = translational acceleration vector of the system center of mass with respect to the inertial frame aP=I = translational acceleration of the projectile center of mass with respect to the inertial frame aT=I = translational acceleration vector of the internal translating mass center of mass with respect to the inertial frame aT=P = translational acceleration of the internal translating mass with respect to the projectile reference frame B = point at center of internal translating mass cavity
Detection of Ni 2 lambda 7378 in six Seyfert galaxies

A line due to Ni 2 7378 in the Seyfert galaxies NGC 1068, 2110, 3227, 4151, 5506, and Arp 102 B was detected. The average Ni abundance is about 2 times solar, which is 5 times less than in the filaments of the Crab Nebula. This argues for nucleosynthetic processing in the latter. The Ni 2 line is spatially revolved in NGC 1068, and shows at least a factor of 4 enhancement in the Ni abundance away from the nucleus. The off-nuclear abundance of Ni in NGC 1068 approaches that of the Crab, which strongly suggests that type supernovae enriched the off-nuclear gas clouds.
Oxazoline-mediated biaryl coupling reactions. Stereocontrolled synthesis of 2,2′,6,6′-tetrasubstituted biphenyls.

Abstract High diastereoselectivities (93:7) were observed in the biaryl coupling of 2′,6′-disubstituted aryl Grignard reagents of 1 with aryloxazolines 2. The diastereoselectivities observed in the coupling reaction varied primarily as a function of the chelating properties of the ortho substituents on the aryl Grignard reagent.
Hydrogen–Helium Mixtures at High Pressure

The properties of hydrogen–helium mixtures at high pressure are crucial to address important questions about the interior of Giant planets e.g. whether Jupiter has a rocky core and did it emerge via core accretion? Using path integral Monte Carlo simulations, we study the properties of these mixtures as a function of temperature, density and composition. The equation of state is calculated and compared to chemical models. We probe the accuracy of the ideal mixing approximation commonly used in such models. Finally, we discuss the structure of the liquid in terms of pair correlation functions.
Apparatus and Procedures for Evaluating Dielectric Properties of Wire Enamels in Controlled Environments

Methods are described for measuring intrinsic dielectric properties of wire enamels and wire enamel-varnish combinations in controlled environments. Random wound bifilar coils serve as test specimens and environment control is achieved by suspending these coils in a pressure tube connected to a gas handling system. Dielectric properties have been measured at pressures ranging from vacuum to 32 atmospheres and at temperatures from -40° to 350°C. Typical results are reported which illustrate utility of the apparatus and procedures. The importance of measuring dielectric properties at elevated temperatures is stressed and a method for establishing a practical thermal limit tmax is described. It is demonstrated that in a controlled environment, tmax, is a characteristic intrinsic property of an insulating material. Interpretation of typical conductance-temperature data according to the theory of rate processes, suggests that tmax corresponds to a temperature at which the polymer undergoes significant changes in viscoelastic behavior. There is evidence that the mechanism of ac conductance below tmax is by polarization, while above tmax conductance results from ion movement. The influence on tmax of degree of cure, frequency of the applied voltage, and nature of the atmosphere surrounding the insulating material, is discussed.
STAT6-mediated keratitis and blepharitis: a novel murine model of ocular atopic dermatitis

PURPOSE Atopic dermatitis (AD) is a common inflammatory disease that can affect the eye, resulting in ocular pathologies, including blepharitis, keratitis, and uveitis; however, the pathogenic mechanisms underlying the ocular manifestations of AD are not well understood. METHODS In the present study, we characterized the ocular pathologies that develop in the Stat6VT mouse model of AD. We examined the cytokine profile of the eyelid lesions, measured the behavioral response, and documented the treatment response to topical steroids. RESULTS Our results show that Stat6VT mice spontaneously developed blepharitis, keratitis, and uveitis similar to that observed in patients with AD. Histologic findings of allergic inflammation in affected eyelids in this model include the presence of a lymphocyte-predominant infiltrate and tissue eosinophilia in the dermis. Gene expression analysis of affected eyelid tissue by quantitative PCR revealed increased amounts of mRNAs for the Th2 cytokines IL-4, IL-5, and IL-13. In addition, increased eyelid scratching was seen in Stat6VT mice with blepharitis. Topical treatment with the corticosteroid clobetasol reduced eyelid inflammation, tissue eosinophilia, and Th2 cytokine expression. CONCLUSIONS The development of AD-like ocular pathologies in this model supports the idea that in humans, AD-associated disease of the eye may be driven by Th2-mediated inflammation and demonstrates that the Stat6VT mouse may be a useful system in which to further investigate pathogenesis of and treatment strategies for blepharitis and other ocular diseases that develop in association with AD.
The term structure of real interest rates: theory and evidence from UK index-linked bonds

Abstract This paper studies the behavior of the default-risk-free real term structure and term premia in two general equilibrium endowment economies with complete markets but without money. In the first economy there are no frictions as in Lucas (Econometrica 46 (1978) 1429) and in the second risk-sharing is limited by the risk of default as in Alvarez and Jermann (Econometrica 68 (2000) 775; Rev. Financial Studies 14 (2001) 1117). Both models are solved numerically, calibrated to UK aggregate and household data, and the predictions are compared to data on real interest rates constructed from the UK index-linked data. While both models produce time-varying risk or term premia, only the model with limited risk-sharing can generate enough variation in the term premia to account for the rejections of expectations hypothesis.
You can have your trust and calculativeness, too: Uncertainty, trustworthiness and the Williamson thesis

Oliver Williamson argues that a principal will only trust an agent when there are safeguards to ensure the agent has an incentive for trustworthiness (Williamson, O. E. [1993]. Calculativeness, trust, and economic organization. The Journal of Law and Economics, 36, 453–486). However, such circumstances are devoid of vulnerability and possibility for betrayal. Williamson claims that this is not trust at all. I argue that a principal can be calculative in his/her decisions to trust an agent but be genuinely vulnerable to betrayal as well. The key is in distinguishing between an environment of risk and one of uncertainty. Uncertainty creates vulnerabilities for principals because of the difficulty in identifying and erecting safeguards that fully assure agent trustworthiness. In such conditions, a principal will also need to rely on the moral disposition of the agent to refrain from engaging in opportunistic behaviour. However, a reliance on moral dispositions creates the possibility of real betrayal. Thus, ...
A fractional Hardy-Sobolev-Maz’ya inequality on the upper halfspace

We prove several Sobolev inequalities, which are then used to establish a fractional Hardy-Sobolev- Maz'ya inequality on the upper halfspace.
Three-dimensional elastic-plastic finite-element analyses of constraint variations in cracked bodies

Three-dimensional elastic-plastic (small-strain) finite-element analyses were used to study the stresses, deformations, and constraint variations around a straight-through crack in finite-thickness plates for an elastic-perfectly plastic material under monotonic and cyclic loading. Middle-crack tension specimens were analyzed for thicknesses ranging from 1.25 to 20 mm with various crack lengths. Three local constraint parameters, related to the normal, tangential, and hydrostatic stresses, showed similar variations along the crack front for a given thickness and applied stress level. Numerical analyses indicated that cyclic stress history and crack growth reduced the local constraint parameters in the interior of a plate, especially at high applied stress levels. A global constraint factor alpha(sub g) was defined to simulate three-dimensional effects in two-dimensional crack analyses. The global constraint factor was calculated as an average through-the-thickness value over the crack-front plastic region. Values of alpha(sub g) were found to be nearly independent of crack length and were related to the stress-intensity factor for a given thickness.
A valuation formula for LDC debt

A large gap may lie between the amount of debt relief that is nominally granted to a debtor and that which is actually given up by the creditors. To help put that gap in perspective, the author proposes a valuation formula that provides: (i) the price at which a buy-back of the debt, on the secondary market, is advantageous to the country; (ii) the value to creditors of having the flows of payment guaranteed against factors that hinder a country in servicing its debt; and (iii) the degree of tradeoff between growth of payments and levels of payments. The author argues that it is not good business for a country to announce its intention to buy back debt, because doing so immediately raises the price. The value of guarantees, the author argues, cannot exceed 25 percent of the market price of the debt. Typically they're worth only about 10 percent. As for the degree of tradeoff, the author's formula finds that 1 percent additional growth rate is worth a 15 percent increase in the flows of payments. An assessment of the Mexican debt-relief agreement reached in 1990 is also offered.
Layer interdependence of transport in an undoped electron-hole bilayer

The layer interdependence of transport in an undoped electron-hole bilayer (UEHBL) device was studied as a function of carrier density, interlayer electric field, and temperature. The UEHBL device consisted of a density tunable, independently contacted two-dimensional electron gas (2DEG) and two-dimensional hole gas (2DHG) in distinct (100) GaAs quantum wells separated by a 30 nm ${\text{Al}}_{0.9}{\text{Ga}}_{0.1}\text{As}$ barrier. The 2DEG and 2DHG are induced via field effect by top and bottom gates, respectively. Transport measurements were made simultaneously on each layer using the van der Pauw method. An increase in 2DHG mobility with increasing 2DEG density was observed, while the 2DEG mobility showed minimal dependence on the 2DHG density. Changes in both surface-gate voltages for the mobility-density measurements were observed. Decreasing the interlayer electric field and thereby increasing interlayer separation also increased the 2DHG mobility with negligible effects on the 2DEG mobility. The change in interlayer separation as interlayer electric field changed was estimated using 2DHG Coulomb drag measurements. A general discussion of the results is given in which the possible sources for the apparent interlayer dependence of the hole transport are examined.
Metal Enrichment of the Intergalactic Medium in Cosmological Simulations

Observations have established that the diffuse intergalactic medium (IGM) at z ~ 3 is enriched to ~10-2.5 solar metallicity and that the hot gas in large clusters of galaxies (ICM) is enriched to - Z☉ at z = 0. Metals in the IGM may have been removed from galaxies (in which they presumably form) during dynamical encounters between galaxies, by ram-pressure stripping, by supernova-driven winds, or as radiation-pressure-driven dust efflux. This study develops a method of investigating the chemical enrichment of the IGM and of galaxies, using already completed cosmological simulations. To these simulations we add dust and (gaseous) metals, assuming instantaneous recycling and distributing the dust and metals in the gas according to three simple parameterized prescriptions, one for each enrichment mechanism. These prescriptions are formulated to capture the basic ejection physics, and calibrated when possible with empirical data. Our method allows exploration of a large number of models, yet for each model yields a specific (not statistical) realization of the cosmic metal distribution that can be compared in detail to observations. Our results indicate that dynamical removal of metals from 108.5 M☉ galaxies cannot account for the observed metallicity of low column density Lyα absorbers and that dynamical removal from 1010.5 M☉ galaxies cannot account for the ICM metallicities. Dynamical removal also fails to produce a strong enough mass-metallicity relation in galaxies. In contrast, either wind or radiation-pressure ejection of metals from relatively large galaxies can plausibly account for all three sets of observations (though it is unclear whether metals can be distributed uniformly enough in the low-density regions without overly disturbing the IGM and whether clusters can be enriched quite as much as observed). We investigate in detail how our results change with variations in our assumed parameters and how results for the different ejection processes compare.
Multi-Path TCP with Network Coding for Mobile Devices in Heterogeneous Networks

Existing mobile devices have the capability to use multiple network technologies simultaneously to help increase performance; but they rarely, if at all, effectively use these technologies in parallel. We first present empirical data to help understand the mobile environment when three heterogeneous networks are available to the mobile device (i.e., a WiFi network, WiMax network, and an Iridium satellite network). We then propose a reliable, multi-path protocol called Multi-Path TCP with Network Coding (MPTCP/NC) that utilizes each of these networks in parallel. An analytical model is developed and a mean-field approximation is derived that gives an estimate of the protocol's achievable throughput. Finally, a comparison between MPTCP and MPTCP/NC is presented using both the empirical data and mean-field approximation. Our results show that network coding can provide users in mobile environments a higher quality of service by enabling the use of multiple network technologies and the capability to overcome packet losses due to lossy, wireless network connections.
The identification of glycerol-3-yl 6-deoxy-6-C-sulfo-α-d-glucopyranoside (glyceryl α-sulfoquinovoside) as a metabolite in Rhizobium, a non-photosynthetic organism

Abstract We have isolated and characterized glycerol-3-yl 6-deoxy-6- C -sulfo- α - d -glucopyranoside (glyceryl α -sulfoquinovoside), a key metabolite involved in sulfoquinovosyl diacylglycerol (SQDG) biosynthesis in photosynthetic organisms, from the cellular metabolic pools of Rhizobium . The compound has not been found in any other non-photosynthetic organisms. This result suggests some commonalities between the biosynthesis of SQDG in Rhizobium and in plant organelles and photosynthetic organisms and further adds to the evolving picture that there is considerable gene overlap between Rhizobium and photosynthetic systems, including plants.
Diverse pathways for the palladium(II)-mediated oxidation of olefins by tert-butylhydroperoxide.

New procedures are described for the palladium-catalyzed oxidation of olefins by tert-butylhydroperoxide under slightly basic conditions in CH2Cl2 solution at 0−25 °C.
Neutron diffusion and nucleosynthesis in an inhomogeneous big bang model

This article presents an original code for big bang nucleosynthesis in a baryon inhomogeneous model of the Universe. In this code neutron diffusion between high and low baryon density regions is calculated simultaneously with the nuclear reactions and weak decays that compose the nucleosynthesis process. The size of the model determines the time when neutron diffusion becomes significant. This article describes in detail how the time of neutron diffusion relative to the time of nucleosynthesis affects the final abundances of $^{4}\mathrm{He}$, deuterium and $^{7}\mathrm{Li}$. These results will be compared with the most recent observational constraints of $^{4}\mathrm{He}$, deuterium and $^{7}\mathrm{Li}$. This inhomogeneous model has $^{4}\mathrm{He}$ and deuterium constraints in concordance for baryon-to-photon ratio $\ensuremath{\eta}=(4.3\ensuremath{-}12.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ $^{7}\mathrm{Li}$ constraints are brought into concordance with the other isotope constraints by including a depletion factor as high as 5.9. These ranges for the baryon-to-photon ratio and for the depletion factor are larger than the ranges from a standard big bang nucleosynthesis model.
Coordinating Multiple Robots with Kinodynamic Constraints Along Specified Paths

This paper focuses on the collision-free coordination of multiple robots with kinodynamic constraints along specified paths. We present an approach to generate continuous velocity profiles for multiple robots; these velocity profiles satisfy the dynamics constraints, avoid collisions, and minimize the completion time. The approach, which combines techniques from optimal control and mathematical programming, consists of identifying collision segments along each robot's path, and then optimizing the robots' velocities along the collision and collision-free segments. First, for each path segment for each robot, the minimum and maximum possible traversal times that satisfy the dynamics constraints are computed by solving the corresponding two-point boundary value problems. The collision avoidance constraints for pairs of robots can then be combined to formulate a mixed integer nonlinear programming (MINLP) problem. Since this nonconvex MINLP model is difficult to solve, we describe two related mixed integer linear programming (MILP) formulations, which provide schedules that give lower and upper bounds on the optimum; the upper bound schedule is designed to provide continuous velocity trajectories that are feasible. The approach is illustrated with coordination of multiple robots, modeled as double integrators subject to velocity and acceleration constraints. An application to coordination of nonholonomic car-like robots is described, along with implementation results for 12 robots.
Coupled-channels treatment of deformed proton emitters

The structure of deformed proton emitters is studied in a coupled-channels treatment. The wave function of a decaying state is determined as a standing wave, i.e., for an energy that is real. The decay rate is calculated from a Green's function method, treating the influence of the long-range Coulomb multipole interactions to first order. The results are compared to predictions made in the adiabatic limit and to measurements. It is shown that the decay of the ${}^{131}\mathrm{Eu}{(3/2}^{+})$ ground state to the ground state of ${}^{130}\mathrm{Sm}$ is quite sensitive to deformation in the spin-orbit force. It is found that the ground state decay of ${}^{141}\mathrm{Ho}{(7/2}^{\ensuremath{-}})$ is poorly described in the coupled-channels approach. This is ascribed to Coriolis mixing, which is too strong in the absence of pairing effects.
Synergy: A Framework for Leadership Development and Transformation

Given the current demands of the health care environment, the need for nurses minimally competent in clinical judgment, caring practice, advocacy and moral agency, collaboration, responsiveness to diversity, systems thinking, inquiry, and facilitation of learning is critical in light of ever-increasing contextual complexity and variability of patient needs. The Synergy Model provides an exemplary and relevant framework for clinical practice with the ultimate aim of improving patient outcomes. Tenets of accountability and professionalism are central to the model and, in its entirety, it provides a practical and useful approach for thinking about and redesigning educational products and processes in clinical settings.
The Prediction of Two-Phase Turbulence and Phase Distribution Phenomena Using a Reynolds Stress Model

The void fraction distribution for turbulent bubbly air/water upflows and downflows in a pipe was analyzed using a three-dimensional two-fluid model. A τ − e (i.e., Reynolds stress) turbulence model was used for the continuous (liquid) phase. The τ − e transport equations yield all components of the Reynolds stress tensor for the liquid phase momentum equations. The effect of these stresses is to create a lateral pressure gradient that acts on the bubbles and effects their distribution. The lateral lift force on the bubbles has also been modelled. This lift force arises due to the relative motion of the bubble with respect to a nonuniform liquid velocity field. It has been observed experimentally that for upflows the bubbles concentrate near the wall while for downflows they move toward the center of the conduit. The model presented herein predicts these trends.
Proper Motions and Origins of SGR 1806–20 and SGR 1900+14

We present results from high-resolution infrared observations of magnetars SGR 1806–20 and SGR 1900+14 over 5 years using laser-supported adaptive optics at the 10 m Keck Observatory. Our measurements of the proper motions of these magnetars provide robust links between magnetars and their progenitors and provide age estimates for magnetars. At the measured distances of their putative associations, we measure the linear transverse velocity of SGR 1806–20 to be 350 ± 100 km s^(–1) and of SGR 1900+14 to be 130 ± 30 km s^(–1). The transverse velocity vectors for both magnetars point away from the clusters of massive stars, solidifying their proposed associations. Assuming that the magnetars were born in the clusters, we can estimate the braking index to be ~1.8 for SGR 1806–20 and ~1.2 for SGR 1900+14. This is significantly lower than the canonical value of n = 3 predicted by the magnetic dipole spin-down suggesting an alternative source of dissipation such as twisted magnetospheres or particle winds.
Casimir effect in the presence of external fields

In this work the Casimir effect is studied for scalar fields in the presence of boundaries and under the influence of arbitrary smooth potentials of compact support. In this setting, piston configurations are analyzed in which the piston is modeled by a potential. For these configurations, analytic results for the Casimir energy and force are obtained by employing the zeta function regularization method. Also, explicit numerical results for the Casimir force are provided for pistons modeled by a class of compactly supported potentials that are realizable as delta-sequences. These results are then generalized to higher dimensional pistons by considering additional Kaluza–Klein dimensions.
Long-Term Effects on Sexual Function of Five Antihypertensive Drugs and Nutritional Hygienic Treatment in Hypertensive Men and Women: Treatment of Mild Hypertension Study (TOMHS)

Problems with sexual function have been a long-standing concern in the treatment of hypertension and may influence the choice of treatment regimens and decisions to discontinue drugs. The Treatment of Mild Hypertension Study (TOMHS) provides an excellent opportunity for examination of sexual function and effects of treatment on sexual function in men and women with stage I diastolic hypertension because of the number of drug classes studied, the double-blind study design, and the long-term follow-up. TOMHS was a double-blind, randomized controlled trial of 902 hypertensive individuals (557 men, 345 women), aged 45 to 69 years, treated with placebo or one of five active drugs (acebutolol, amlodipine maleate, chlorthalidone, doxazosin maleate, or enalapril maleate). All participants received intensive lifestyle counseling regarding weight loss, dietary sodium reduction, alcohol reduction (for current drinkers), and increased physical activity. Sexual function was ascertained by physician interviews at baseline and annually during follow-up. At baseline, 14.4% of men and 4.9% of women reported a problems with sexual function. In men, 12.2% had problems obtaining and/or maintaining an erection; 2.0% of women reported a problem having an orgasm. Erection problems in men at baseline were positively related to age, systolic pressure, and previous antihypertensive drug use. The incidences of erection dysfunction during follow-up in men were 9.5% and 14.7% through 24 and 48 months, respectively, and were related to type of antihypertensive therapy. Participants randomized to chlorthalidone reported a significantly higher incidence of erection problems through 24 months than participants randomized to placebo (17.1% versus 8.1%, P = .025). Incidence rates through 48 months were more similar among treatment groups than at 24 months, with nonsignificant differences between the chlorthalidone and placebo groups. Incidence was lowest in the doxazosin group but was not significantly different from the placebo group. Incidence for acebutolol, amlodipine, and enalapril groups was similar to that in the placebo group. In many cases, erection dysfunction did not require withdrawal of medication. Disappearance of erection problems among men with problems at baseline was common in all groups but greatest in the doxazosin group. Incidence of reported sexual problems in women was low in all treatment groups. In conclusion, long-term incidence of erection problems in treated hypertensive men is relatively low but is higher with chlorthalidone treatment. Effects of erection dysfunction with chlorthalidone appear relatively early and are often tolerable, and new occurrences after 2 years are unlikely. The rate of reported sexual problems in hypertensive women is low and does not appear to differ by type of drug. Similar incidence rates of erection dysfunction in placebo and most active drug groups caution against routine attribution of erection problems to antihypertensive medication.
Mixed norm estimates for certain generalized Radon transforms

We obtain essentially optimal local mixed norm inequalities for certain generalized Radon transforms defined by integration over curves.
A SENSITIVITY ANALYSIS OF THE GRAVITY MODEL

Abstract In this article, we examine the robustness of variables used in the gravity model literature. We use a variant of Leamer's extreme-bounds analysis, which tracks the sign and significance level of the variable of interest to changes in the conditioning set of variables. Of the 47 variables investigated, we find 20 measuring level of development, trade policy, linguistic and colonial ties, geographic factors, relative population density, common currency, and membership in the Central American Common Market (CACM), Caribbean Community (Caricom), Mercado Comun del Sur (Mercosur), Australia-New Zealand Closer Economic Relations Trade Agreement (ANZCERTA), and Asian Pacific Economic Cooperation (APEC) are robustly linked to trade. As a result, this study provides researchers with a suitable starting point in which to examine new potential determinants of international trade.
Gene therapy for phenylketonuria

Classical phenylketonuria (PKU) is an autosomal recessive disorder caused by a deficiency of hepatic phenylalanine hydroxylase (PAH). Limitations of the current dietary treatment for PKU have led to the development of potential treatments based on somatic gene transfer. Three different vector systems have been examined. Vectors derived from a recombinant retrovirus or a DNA/protein complex can efficiently transduce the PAH cDNA into PAH-deficient hepatocytes in vitro, but the application of these vector systems is presently limited by their low transduction efficiency in vivo. In contrast, a vector derived from a recombinant adenovirus can restore 10%–80% of normal hepatic PAH activity into PAH-deficient mice, which completely normalizes serum phenylalanine levels. This treatment is transient and cannot be effectively re-administered due to the presence of neutralizing antibodies directed against the recombinant adenoviral vector. However, these findings suggest that PKU can be completely corrected by somatic gene therapy, and provide some direction for the future development of adenoviral vectors.
Distributed ionosphere monitoring by collaborating mobile receivers

This paper presents a novel ionospheric anomaly monitoring method for ground-based augmentation systems, based on a network of collaborative airborne dual-frequency receivers. The method allows aircraft to navigate safely using a single frequency or divergence-free position solution, methods that are more accurate than the ionosphere-free position solution. Each receiver measures ionospheric delays; measurements are shared among collaborators to estimate the local ionospheric gradient, which may be different for each satellite during a storm.
Proline affects ACC to ethylene conversion under salt and water stresses in the halophyte, Allenrolfea occidentalis

Salt (NaCl) and water (partial dehydration) stresses applied to the halophyte, Allenrolfea occidentalis (S.Wats) Kuntze, increased the conversion of ACC (l-aminocyclopropane-l-carboxylic acid) to ethylene. Exposure of stressed tissue to exogenously applied proline (an osmoprotectant) completely neutralized the increased ethylene production induced by the NaCl and dehydration treatments.
Reactive Ion Etching of PECVD Amorphous Silicon and Silicon Nitride Thin Films with Fluorocarbon Gases

Plasma‐enhanced chemical vapor deposited (PECVD) amorphous silicon (α‐Si:H) and silicon nitride films have been reactive ion etched with fluorocarbon gases. Process parameters such as power, pressure, and gas flow rate have tremendous effects on etch rates and the etch selectivity. The film etch rate increases with the increase of the power under various pressure and flow rate conditions. Etching mechanisms of three gases (, , and ) are different. With the same gas and etching condition, etching mechanisms of α‐Si:H and nitride are also different. For the plasma, both the plasma‐phase chemistry and the self‐bias voltage control the etch rate and the etch selectivity of nitride to α‐Si:H. For the plasma, the self‐bias voltage dominates the etch rate and the etch selectivity. For the plasma, a self‐bias voltage higher than a threshold voltage is required before the film can be etched. The etch selectivity of nitride to α‐Si:H is greater than one with all etching conditions. An etch selectivity as high as 25 has been obtained with or . ESCA spectra show that the etched surface is clean, the etched surface is probably covered with a carbonaceous layer, and the etched surface is coated with the fluorocarbon polymer.
Impact of four-quark shape functions on inclusive B decay spectra

It has recently been pointed out that a new class of subleading shape functions involving B-meson matrix elements of non-local four-quark operators contributes at order $\Lambda_{\rm QCD}/m_b$ to $\bar{B}\to X_u l^-\bar{\nu}$ decay distributions in the endpoint region. The corresponding functions $f_u(\omega)$ and $f_v(\omega)$ are estimated using the vacuum-insertion approximation. A numerical analysis of various $\bar{B}\to X_u l^-\bar{\nu}$ decay spectra suggests that these power corrections are very small, below present theoretical uncertainties due to other subleading shape-function contributions.
The Hidden Subgroup Problem for Generalized Quaternions

The hidden subgroup problem is a pivotal problem in quantum computation since it reflects the structure of tasks for which quantum algorithms significantly outperform classical algorithms. In this paper, a quantum algorithm that solves the hidden subgroup problem over the generalized quaternion group is developed. The algorithm employs the abelian quantum Fourier transform and Kuperberg sieve to reveal the hidden subgroup.
Going Home after Hurricane Katrina: Determinants of Return Migration and Changes in Affected Areas

This article examines the decision of Hurricane Katrina evacuees to return to their pre-Katrina areas and documents how the composition of the Katrina-affected region changed over time. Using data from the Current Population Survey, we show that an evacuee’s age, family income, and the severity of damage in an evacuee’s county of origin are important determinants of whether an evacuee returned during the first year after the storm. Blacks were less likely to return than whites, but this difference is primarily related to the geographical pattern of storm damage rather than to race per se. The difference between the composition of evacuees who returned and the composition of evacuees who did not return is the primary force behind changes in the composition of the affected areas in the first two years after the storm. Katrina is associated with substantial shifts in the racial composition of the affected areas (namely, a decrease in the percentage of residents who are black) and an increasing presence of Hispanics. Katrina is also associated with an increase in the percentage of older residents, a decrease in the percentage of residents with low income/education, and an increase in the percentage of residents with high income/education.
Simultaneous motion estimation and image reconstruction (SMEIR) for 4D cone-beam CT

Image reconstruction and motion model estimation in four dimensional cone-beam CT (4D-CBCT) are conventionally handled as two sequential steps. Due to the limited number of projections at each phase, the image quality of 4D-CBCT is degraded by view aliasing artifacts, and the accuracy of subsequent motion modeling is decreased by the inferior 4DCBCT. The objective of this work is to enhance both the image quality of 4D-CBCT and the accuracy of motion model estimation with a novel strategy enabling simultaneous motion estimation and image reconstruction (SMEIR). The proposed SMEIR algorithm consists of two alternating steps: 1) model-based iterative image reconstruction to obtain a motion-compensated primary CBCT (m-pCBCT) and 2) motion model estimation to obtain an optimal set of deformation vector fields (DVFs) between the m-pCBCT and other 4D-CBCT phases. The motion-compensated image reconstruction is based on the simultaneous algebraic reconstruction (SART) technique coupled with total variation minimization. During the forward- and back-projection of SART, measured projections from an entire set of 4D-CBCT are used for reconstruction of the m-pCBCT by utilizing the updated DVF. The DVF is estimated by matching the forward projection of the deformed m-pCBCT and measured projections of other phases of 4D-CBCT. The performance of the SMEIR algorithm is quantitatively evaluated on a 4D NCAT phantom. The SMEIR algorithm improves image reconstruction accuracy of 4D-CBCT and tumor motion trajectory estimation accuracy as compared to conventional sequential 4D-CBCT reconstruction and motion estimation.
A Mariner/MESSENGER global catalog of mercurian craters

Abstract Using MESSENGER and Mariner 10 flyby images, we have compiled a global catalog of impact structures with diameters D > 10 km. The distribution of impact structures shows a factor of 10 range in areal crater density. Most regions of low crater density are located within large impact basins, consistent with the idea that these were low-lying areas that have been filled by subsequent volcanism over an extended period.
Properties of the Λ(1405) Measured at CLAS

Abstract Using the CLAS detector system in Hall B at Jefferson Lab, we have done a high statistics measurement of the photoproduction of K + Λ ( 1405 ) using a proton target. The reconstructed invariant mass seen in the various Σ π decay modes has been measured, as well as the differential cross section d σ d t . The nature of the Λ ( 1405 ) with its peculiar mass distribution is not well understood, and studies have shown that it may posess strong dynamical components, which could be extracted from our data. Various aspects of our analysis are discussed, as well as future prospects to further enhance the precision of the results.
The gabbro-eclogite phase transition and the elevation of mountain belts on Venus

Among the four mountain belts surrounding Lakshmi Planum, Maxwell Montes is the highest and stands up to 11 km above the mean planetary radius and 7 km above Lakshmi Planum. The bulk composition and radioactive heat production of the crust on Venus, where measured, are similar to those of terrestrial tholeiitic basalt. Because the thickness of the low-density crust may be limited by the gabbro-garnet granulite-eclogite phase transitions, the 7-11 km maximum elevation of Maxwell Montes is difficult to understand except in the unlikely situation that the crust contains a large volume of magma. A possible explanation is that the base of the crust is not in phase equilibrium. It has been suggested that under completely dry conditions, the gabbro-eclogite phase transition takes place by solid-state diffusion and may require a geologically significant time to run to completion. Solid-state diffusion is a strongly temperature-dependent process. In this paper we solve the thermal evolution of the mountain belt to attempt to constrain the depth of the gabbro-eclogite transition and thus to assess this hypothesis quantitatively. The one-dimensional heat equation is solved numerically by a finite difference approximation. The deformation of the horizontally shortening crustal and mantle portions of the thermal boundary layer is assumed to occur by pure shear, and therefore the vertical velocity is given by the product of the horizontal strain rate and depth.
Lower bounds on the performance of Analog to Digital Converters

This paper deals with the task of finding certified lower bounds for the performance of Analog to Digital Converters (ADCs). A general ADC is modeled as a causal, discrete-time dynamical system with outputs taking values in a finite set. We define the performance of an ADC as the worst-case average intensity of the filtered input matching error. The input matching error is the difference between the input and output of the ADC. This error signal is filtered using a shaping filter, the passband of which determines the frequency region of interest for minimizing the error. The problem of finding a lower bound for the performance of an ADC is formulated as a dynamic game problem in which the input signal to the ADC plays against the output of the ADC. Furthermore, the performance measure must be optimized in the presence of quantized disturbances (output of the ADC) that can exceed the control variable (input of the ADC) in magnitude. We characterize the optimal solution in terms of a Bellman-type inequality. A numerical approach is presented to compute the value function in parallel with the feedback law for generating the worst case input signal. The specific structure of the problem is used to prove certain properties of the value function that allow for iterative computation of a certified solution to the Bellman inequality. The solution provides a certified lower bound on the performance of any ADC with respect to the selected performance criteria.
SERS as a bioassay platform: fundamentals, design, and applications

Bioanalytical science is experiencing a period of unprecedented growth. Drivers behind this growth include the need to detect markers central to human and veterinary diagnostics at ever-lower levels and greater speeds. A set of parallel arguments applies to pathogens with respect to bioterrorism prevention and food and water safety. This tutorial review outlines our recent explorations on the use of surface enhanced Raman scattering (SERS) for detection of proteins, viruses, and microorganisms in heterogeneous immunoassays. It will detail the design and fabrication of the assay platform, including the capture substrate and nanoparticle-based labels. The latter, which is the cornerstone of our strategy, relies on the construction of gold nanoparticles modified with both an intrinsically strong Raman scatterer and an antibody. This labelling motif, referred to as extrinsic Raman labels (ERLs), takes advantage of the well-established signal enhancement of scatterers when coated on nanometre-sized gold particles, whereas the antibody imparts antigenic specificity. We will also examine the role of plasmon coupling between the ERLs and capture substrate, and challenges related to particle stability, nonspecific adsorption, and assay speed.
Optimal time bounds for approximate clustering

Clustering is a fundamental problem in unsupervised learning, and has been studied widely both as a problem of learning mixture models and as an optimization problem. In this paper, we study clustering with respect to the k-median objective function, a natural formulation of clustering in which we attempt to minimize the average distance to cluster centers. One of the main contributions of this paper is a simple but powerful sampling technique that we call successive sampling that could be of independent interest. We show that our sampling procedure can rapidly identify a small set of points (of size just O(k log \frac{n}{k})) that summarize the input points for the purpose of clustering. Using successive sampling, we develop an algorithm for the k-median problem that runs in O(nk) time for a wide range of values of k and is guaranteed, with high probability, to return a solution with cost at most a constant factor times optimal. We also establish a lower bound of Ω(nk) on any randomized constant-factor approximation algorithm for the k-median problem that succeeds with even a negligible (say \frac{1}{100}) probability. The best previous upper bound for the problem was O(nk), where the O-notation hides polylogarithmic factors in n and k. The best previous lower bound of Ω(nk) applied only to deterministic k-median algorithms. While we focus our presentation on the k-median objective, all our upper bounds are valid for the k-means objective as well. In this context our algorithm compares favorably to the widely used k-means heuristic, which requires O(nk) time for just one iteration and provides no useful approximation guarantees.
Turbulent Boundary Layer and Heat Transfer Measurements Along a Convergent-Divergent Nozzle

Turbulent boundary layer and heat transfer measurements along cooled conical convergent- divergent nozzle
Solar energy storage reactions involving metal complexes

Photochemical properties of transition metal complexes are discussed as they relate to possible schemes for energy storage. Complexes of copper(I) with π-acceptor ligands have been used to sensitize isomerizations of organic molecules, and there is room for considerable further investigation in this area. Electron transfer reactions have been more intensively studied. These reactions fall into three broad categories: ionization, oxidative addition/reductive elimination, and excited state electron transfer. Experiments in the first two categories have generally led to rather poor storage efficiency and have required ultraviolet light. But long-lived excited states of coordination compounds can participate in chemical reactions with high efficiency, and such systems are promising for solar energy storage. Specific systems of this type that are discussed in detail involve electron transfer quenching of the lowest emissive excited states of Ru(2, 2′-bipyridine) 3 2+ , M 2 (diisocyanoalkane) 4 2+ (M=Rh, Ir), and Mo 6 Cl 14 2− .
Analytical Asymptotic Structure of the Slater Exchange and Kohn-Sham Exchange and Correlation Potentials at a Metal Surface

Abstract In this paper we consider the semi-infinite jellium and structureless pseudopotential models of a metal surface and derive the exact analytical asymptotic structure in the classically forbidden region of (i) the Slater exchange potentialVsx(r), (ii) the Kohn–Sham exchange potentialνx(r), and thus of the optimized potential method exchange potentialνOPMx(r), and show these latter potentials to decay as 1 2 Vsx(r). With the assumption that the Kohn–Sham exchange-correlation potentialνxc(r) decays asymptotically as the image potential, we thereby derive (iii) the analytical asymptotic structure of the Kohn–Sham correlation potentialνc(r). These potentials all decay as −x−1with coefficients which depend upon the Fermi energy and surface barrier height. However, it is onlyνx(r) that is image-potential-like, the coefficient being 1 4 for stable jellium. Thus, with exchange and correlation effects considered separately, the principal contribution to the asymptotic image potential structure arises due to Pauli correlations, the Coulomb correlation contribution being weak. We also show (iv) analytically that for a slab-metal geometry, the potentialνx(r) decays as −x−2and explain why this is the case. Finally, we show (v) analytically that two approximate Kohn–Sham exchange potentials in the literature possess the correct 1 2 Vsx(r) asymptotic structure in the vacuum. With exchange and correlation considered together, the assumption that the asymptotic image potential structure ofνxc(r) is independent of metal parameters provides an alternate “classical” interpretation of the physical origin of this structure. It is due to those Coulomb correlations which contribute to that part of the Coulomb hole (of charge −e) localized to the surface region, the component (of charge +e) delocalized in the metal bulk screening out the corresponding delocalized Fermi hole distribution (of charge −e).