cssi/SciSciGPT-SciSciNet huggingface dataset:
Size of Spectroscopic Calibration Samples for Cosmic Shear Photometric Redshifts

Weak gravitational lensing surveys using photometric redshifts can have their cosmological constraints severely degraded by errors in the photo-z scale. We explore the cosmological degradation versus the size of the spectroscopic survey required to calibrate the photo-z probability distribution. Previous work has assumed a simple Gaussian distribution of photo-z errors; here, we describe a method for constraining an arbitrary parametric photo-z error model. As an example we allow the photo-z probability distribution to be the sum of NG Gaussians. To limit cosmological degradation to a fixed level, photo-z distributions comprised of multiple Gaussians require up to a 5 times larger calibration sample than one would estimate from assuming a single-Gaussian model. This degradation saturates at NG ≈ 4 in the simple case where the fiducial distribution is independent of NG. Assuming a single Gaussian when the photo-z distribution has multiple parameters underestimates cosmological parameter uncertainties by up to 35%. The size of required calibration sample also depends on the shape of the fiducial distribution, even when the rms photo-z error is held fixed. The required calibration sample size varies up to a factor of 40 among the fiducial models studied, but this is reduced to a factor of a few if the photo-z error distributions are forced to be slowly varying with redshift. Finally, we show that the size of the required calibration sample can be substantially reduced by optimizing its redshift distribution. We hope this study will help stimulate work on better understanding of photo-z errors.
SOME IMPLEMENTATIONAL ISSUES OF CONVECTION SCHEMES FOR FINITE-VOLUME FORMULATIONS

Two higher-order upwind schemes - second-order upwind and QUICK - are examined in terms of their interpretation, implementations, as well as performance for a recirculating flow in a lid-driven cavity, in the context of a control-volume formulation using the SIMPLE algorithm. The present formulation of these schemes is based on a unified framework wherein the first-order upwind scheme is chosen as the basis, with the remaining terms being assigned to the source term. The performance of these schemes is contrasted with the first-order upwind and second-order central difference schemes. Also addressed in this study is the issue of boundary treatment associated with these higher-order upwind schemes. Two different boundary treatments - one that uses a two-point scheme consistently within a given control volume at the boundary, and the other that maintains consistency of flux across the interior face between the adjacent control volumes - are formulated and evaluated.
Interfacial propulsion by directional adhesion

Abstract The rough integument of water-walking arthropods is well-known to be responsible for their water-repellency [1] , [2] , [3] , [4] ; however, water-repellent surfaces generally experience reduced traction at an air–water interface [5] , [6] , [7] , [8] . A conundrum then arises as to how such creatures generate significant propulsive forces while retaining their water-repellency. We here demonstrate through a series of experiments that they do so by virtue of the detailed form of their integument; specifically, their tilted, flexible hairs interact with the free surface to generate directionally anisotropic adhesive forces that facilitate locomotion. We thus provide new rationale for the fundamental topological difference in the roughness on plants and water-walking arthropods, and suggest new directions for the design and fabrication of unidirectional superhydrophobic surfaces.
Dislocation structure and energy of high angle [001] twist boundaries: A computer simulation study

High angle (001) twist boundaries have been frequently investigated experimentally and the presence of grain boundary dislocations (gbd's) and associated cusps in the dependence of the boundary energy on misorientation, is in this case well established. However, in previous computer simulations of these boundaries neither localised gbd's nor distinct energy cusps have been identified. The principal aim of the present study is to clarify this discrepancy between observations and computer modelling. For this urpose the structure and energy of a number of long period (high ∑) twist boundaries with misorientations very close to ∑ = 5 have been calculated using empirical pair and n-body potentials to describe interatomic forces. Furthermore, an isolated gbd embedded into a ∑ = 5 boundary has been modelled. Well defined cusps at ∑ = 5 misorientation and localised gbd's have been found but the reference ∑ = 5 structure is always the lowest energy structure which, in general, does not possess the symmetry of the coincidence site lattice. The misorientation dependence of the boundary energy is then discussed using a Read-Shockley type model. The cusps are always very shallow and may have an uncoventional shape which is related to the dependence of the elastic energy on misorientation that is not the same for twist and tilt boundaries, contrary to what is usually assumed. Finally, some remaining discrepancies between observed types of gbd's and those found in the present study are discussed in the light of the previously proposed multiplicities of boundary structures.
Methylated Tumor-Specific DNA as a Plasma Biomarker in Patients with Glioma

Objective: Patients with systemic malignancies have substantial quantities of tumor-specific DNA in their plasma which may serve as a potential biomarker for tumor burden. This approach has not been studied in gliomas. Methods: Methylation specific polymerase chain reaction (MSP) was used to determine the methylation status the promoters for p16/INK4a, MGMT, p73, and RARβ within glioma tissue and plasma. Blood was collected prior to craniotomy in 10 patients with glioma. DNA was extracted from tumor and plasma samples and assayed with MSP. Total plasma DNA also was quantified. Tumor-specific plasma DNA was defined as identification of the same methylated promoter (MP) in both tumor and plasma. Results: Total plasma DNA concentration was markedly elevated (mean 6,503 ng/ml, SEM 1,400 ng/ml). Glioma tissue contained methylation of at least one promoter in 9 out of 10 (90 percent) of patients studied. Of these patients, 6 out of 9 (67 percent) demonstrated methylation of at least one of the same promoters in...
Objects, interference, and the Yoneda embedding

Abstract We present a new semantics for Algol-like languages that combines methods from two prior lines of development: 1. the object-based approach of Reddy, where the meaning of an imperative program is described in terms of sequences of observable actions, and 2. the functor-category approach initiated by Reynolds, where the varying nature of the run-time stack is explained using functors from a category of store shapes to a category of cpos. The semantics gives an account of both the phemomena of local state and irreversibility of state change. As an indication of the accuracy obtained, we present a full abstraction result for closed terms of second-order type in a language containing active expressions, i.e. value-returning commands.
Effect of Interface Roughness on Fatigue Crack Growth in Sn-Pb Solder Joints

The effect of interface roughness on fatigue crack growth was studied by examining the contribution of crack-surface sliding to the fatigue crack growth resistance of the interface in 63Sn-37Pb solder joints. Model interfaces with different values of roughness were produced in Sn-Pb/Cu joints by systematically varying the morphology of the intermetallic phase at the interface. Fracture mechanics analysis was conducted to calculate the crack-sliding resistance as a function of interface roughness, contact zone length, the shear strength of the solder, and elastic properties of bi-materials. The results were compared to the variation of fatigue crack growth threshold with interface morphology.
Diastereoselective addition of organometallic reagents to chiral iminium ions: Synthesis of (S)-(+)-cryptostyline I.

Abstract Iminium ion 2c participates in stereoselective nucleophilic addition reactions with Grignard reagents. Analysis of the products from reaction of 5-hexenylmagnesium bromide with iminium ion 2a suggests that these reactions proceed by a polar (two electron) mechanism. The utility of this chemistry is demonstrated in a stereospecific synthesis of (S)-(+)-cryptostylina I.
Acylation-cyclization of allenes

Abstract Allenes bearing a nucleophilic group cyclize on treatment with acyltetracarbonyl cobalt complexes in the presence of mild bases. Various nucleophilic groups and cobalt complexes can be used to give highly functionalized pyrrolidines, cyclopentanes and tetrahydrofurans. Disubstituted allenes may be used in the reaction. 1,3-disubstituted allenes give products with high stereoselectivity.
High-order flux correction/finite difference schemes for strand grids

A novel high-order method combining unstructured flux correction along body surfaces and high-order finite differences normal to surfaces is formulated for unsteady viscous flows on strand grids. The flux correction algorithm is applied in each unstructured layer of the strand grid, and the layers are then coupled together via a source term containing derivatives in the strand direction. Strand-direction derivatives are approximated to high-order via summation-by-parts operators for first derivatives and second derivatives with variable coefficients. We show how this procedure allows for the proper truncation error canceling properties required for the flux correction scheme. The resulting scheme possesses third-order design accuracy, but often exhibits fourth-order accuracy when higher-order derivatives are employed in the strand direction, especially for highly viscous flows. We prove discrete conservation for the new scheme and time stability in the absence of the flux correction terms. Results in two dimensions are presented that demonstrate improvements in accuracy with minimal computational and algorithmic overhead over traditional second-order algorithms.
Spin-orbit density wave induced hidden topological order in URu2Si2.

The conventional order parameters in quantum matters are often characterized by ‘spontaneous’ broken symmetries. However, sometimes the broken symmetries may blend with the invariant symmetries to lead to mysterious emergent phases. The heavy fermion metal URu2Si2 is one such example, where the order parameter responsible for a second-order phase transition at Th = 17.5 K has remained a long-standing mystery. Here we propose via ab-initio calculation and effective model that a novel spin-orbit density wave in the f-states is responsible for the hidden-order phase in URu2Si2. The staggered spin-orbit order spontaneously breaks rotational, and translational symmetries while time-reversal symmetry remains intact. Thus it is immune to pressure, but can be destroyed by magnetic field even at T = 0 K, that means at a quantum critical point. We compute topological index of the order parameter to show that the hidden order is topologically invariant. Finally, some verifiable predictions are presented.
Coalescence of Thin Films of Gold Condensed on Glass

Thin films of gold were deposited by evaporation onto glass surfaces generated by slow fracture in a vacuum. Such films characteristically show an agglomerated or coalesced structure. Deliberate contamination of the substrate and growing films with O2, CO2, H2O, and Ar by exposure to a pressure of 0.0013 Pa (1×10−5 torr) of the gas had no effect on the structure of films of an average thickness of 5 nm (50 A). Similar treatment of the films with N2 resulted in a decrease in the extent of agglomeration of the gold. Treatment of the substrate with N2 prior to the deposition caused an even greater decrease in agglomeration. Films of an average thickness of 2 nm (20 A) were not affected detectably by the N2 treatment. The available evidence indicated that the N2 acted directly on the glass and that the structure of the films was unaffected by minor variations in the age of the surface or by differences in the speed of the fracture which generated the surface. The film structure was not changed by extended exposure to the atmosphere.
Palladium-Catalyzed Intramolecular α-Arylation of α-Amino Acid Esters

The Pd-catalyzed intramolecular α-arylation of α-amino acid esters is described. Starting from readily available amino acids, the synthesis of a variety of isoindolines and tetrahydroisoquinoline carboxylic acid esters has been accomplished. Additionally, fused tricyclic systems can be efficiently prepared from cyclic amino acid esters. Reaction conditions have been found that allow the use of tert-butyl ester and N-(benzyloxycarbonyl) protecting groups.
Crystal structure of osmylated c60: confirmation of the soccer ball framework.

An x-ray crystal structure that confirms the soccer ball-shaped carbon framework of C60 (buckminsterfullerene) is reported. An osmyl unit was added to C60 in order to break its pseudospherical symmetry and give an ordered crystal. The crystal structure of this derivative, C60(OsO4)(4-tert-butylpyridine)2, reveals atomic positions within the carbon cluster.
Relativistic Poynting Jets from Accretion Disks

A model is derived for relativistic Poynting jets from the inner region of a disk around a rotating black hole that is initially threaded by a dipole-like magnetic field. The model is derived from the special relativistic equation for a force-free electromagnetic field. The "head" of the Poynting jet is found to propagate outward with a velocity that may be relativistic. The Lorentz factor of the head is Γ = [B/(8π)2ρextc2]1/6 if this quantity is much larger than unity. For conditions pertinent to an active galactic nuclei, Γ ≈ 8(10/)1/3(B0/103 G)1/3(next/1 cm-3)-1/6, where B0 is the magnetic field strength close to the black hole, ρext = next is the mass density of the ambient medium into which the jet propagates, = r0/rg > 1, where rg is the gravitational radius of the black hole, and r0 is the radius of the O-point of the initial dipole field. This model offers an explanation for the observed Lorentz factors of ~10 of parsec-scale radio jets measured with very long baseline interferometry.
Legal ramifications of off-label filler use

Dermal fillers are often used in an off-label manner. Most off-label use is not only legal, but represents an appropriate physician standard of care. This chapter will first explore what is and what is not considered off-label. Then the chapter will explore manufacturer promotion of off-label use of both drugs and devices. Finally, the legal ramifications of off-label dermal filler use will be discussed.
Test of thick pixelated orbotech detectors with and without steering grids

We report here on the optimization of 0.5 cm thick pixelated Orbotech CZT detectors with regards to the best contacting materials and the use of steering grids. We evaluated the performance of different contacting materials. Our study differs from earlier ones in that we investigated the performance of different anode and cathode materials separately. We obtain the best performance with Au cathodes. For different anode materials Ti and In give the best energy resolutions. The detector (2.0×2.0×0.5 cm 3 , 8×8 pixels) shows excellent 59 keV, 122 keV and 662 keV energy resolutions of 1.4 keV, 1.9 keV, and 7.4 keV, respectively. Furthermore, we report on using steering grids to improve on the performance of the pixelated detectors. Previously, the benefit of steering grids had been limited by additional electronic noise associated with currents between the negatively biased steering grids and the anode pixels. We are currently exploring the possibility to isolate the steering grid from the CZT substrates by a thin layer of Al 2 O 3 . We performed a series of measurements to determine by how much the isolation layer reduces the grid-pixel currents. Comparing the currents between two Au contacts before and after isolating one of the two contacts from the CZT with a 700 nm thick layer of Al 2 O 3 , we measure that the isolation layer reduces the currents by a factor of about 10 at 500 V. We present some results from a detector before and after deposition of an isolated steering grid. The grid indeed improves on the detectors energy resolution and detection efficiency. We show that simulations can be used to model the anode to cathode charge correlation in excellent agreement with the experimental results.
Pathologic caveolin-1 regulation of PTEN in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive fibroproliferative disorder refractory to current pharmacological therapies. Fibroblasts isolated from IPF patients display pathological activation of PI3K/Akt caused by low PTEN phosphatase activity. This enables these cells to escape the negative proliferative properties of polymerized collagen. The mechanism underlying low PTEN activity in IPF fibroblasts is unclear, but our prior studies indicate that membrane-associated PTEN expression is decreased in these cells. Caveolin-1 is an integral membrane protein whose expression is decreased in IPF lung tissue, but how low caveolin-1 contributes to pathological fibrosis is incompletely understood. The objective of this study was to examine the hypothesis that caveolin-1 regulates PTEN function in IPF fibroblasts. Here we demonstrate that caveolin-1 expression is a determinant of membrane PTEN levels and show that PTEN interacts with caveolin-1 via its caveolin-1–binding sequence. We demonstrate that caveolin-1 expression is low in IPF fibroblasts and that this correlates with low membrane PTEN levels, whereas overexpression of caveolin-1 restores membrane PTEN levels, inhibits Akt phosphorylation, and suppresses proliferation. We demonstrate that caveolin-1 and PTEN expression are low in myofibroblasts within IPF fibroblastic foci. These data indicate that IPF fibroblasts display low caveolin-1 expression, which results in low membrane-associated PTEN expression. This creates a membrane microenvironment depleted of inhibitory phosphatase activity, facilitating the aberrant activation PI3K/Akt and pathological proliferation.
Ergodic capacity analysis in cognitive radio systems under channel uncertainty

In this paper, pilot-symbol-assisted transmission in cognitive radio systems over time selective flat fading channels is studied. It is assumed that causal and noncausal Wiener filter estimators are used at the secondary receiver with the aid of training symbols to obtain the channel side information (CSI) under an interference power constraint. Cognitive radio model is described together with detection and false alarm probabilities determined by using a Neyman-Person detector for channel sensing. Subsequently, for both filters, the variances of estimate errors are calculated from the Doppler power spectrum of the channel, and achievable rate expressions are provided considering the scenarios which are results of channel sensing. Numerical results are obtained in Gauss-Markov modeled channels, and achievable rates obtained by using causal and noncausal filters are compared and it is shown that the difference is decreasing with increasing signal-to-noise ratio (SNR).Moreover, the optimal probability of detection and false alarm values are shown, and the tradeoff between these two parameters is discussed. Finally, optimal power distributions are provided.
The subject-researcher relationship: in defense of contracting around default rules.

Does an absolute standard of minimal risk always do a better job than a relative standard of minimal risk in regard to protecting and promoting the benefit of populations that are entitled to be pr...
Total synthesis of calebin-A, preparation of its analogues, and their neuronal cell protectivity against β-amyloid insult

A total synthesis of Calebin-A (1), a novel curcuminoid isolated from turmeric (Curcuma longa, Zingiberaceae) that has been demonstrated to protect neuronal cells from beta-amyloid insult, was successfully achieved in four steps. Elaborating on this synthetic route, 13 analogues were prepared for a structure-activity relationship (SAR) study. It was found that the parent compound 1 and derivatives 21, 28, and 30 protect PC12 rat pheocromocytoma and IMR-32 human neuroblastoma cells from beta-amyloid(25-35) insult. These results suggest that hydroxy group at para-position is most critical for the expression of biological activity.
Proper actions of lattices on contractible manifolds

Every lattice Γ in a connected semi-simple Lie group G acts properly discontinuously by isometries on the contractible manifold G/K (K a maximal compact subgroup of G). We prove that if Γ acts on a contractible manifold W and if either¶1) the action is properly discontinuous, or¶2) W is equipped with a complete Riemannian metric, the action is by isometries and with unbounded orbits, G is simple with finite center and rank >1,¶then dimW≥dimG/K.
Discovery of A Young L Dwarf Binary, SDSS J224953.47+004404.6AB

We report discovery of a young 0.''32 L dwarf binary, SDSS J2249+0044AB, found as the result of a Keck laser guide star adaptive optics imaging survey of young field brown dwarfs. Weak K I, Na I, and FeH features as well as strong VO absorption in the integrated-light J-band spectrum indicate a low surface gravity and hence young age for the system. From spatially resolved K-band spectra we determine spectral types of L3 {+-} 0.5 and L5 {+-} 1 for components A and B, respectively. SDSS J2249+0044A is spectrally very similar to G196-3B, an L3 companion to a young M2.5 field dwarf. Thus, we adopt 100 Myr (the age estimate of the G196-3 system) as the age of SDSS J2249+0044AB, but ages of 12-790 Myr are possible. By comparing our photometry to the absolute magnitudes of G196-3B, we estimate a distance to SDSS J2249+0044AB of 54 {+-} 16 pc and infer a projected separation of 17 {+-} 5 AU for the binary. Comparison of the luminosities to evolutionary models at an age of 100 Myr yields masses of 0.029 {+-} 0.006 and 0.022{sup +0.006}{sub -0.009} M{sub sun} for SDSS J2249+0044A and B, respectively. Over the possible ages of the systemmore » (12-790 Myr), the mass of SDSS J2249+0044A could range from 0.011 to 0.070 M{sub sun} and the mass of SDSS J2249+0044B could range from 0.009 to 0.065 M{sub sun}. Evolutionary models predict that either component could be burning deuterium, which could result in a mass ratio as low as 0.4, or alternatively, a reversal in the luminosities of the binary. We find a likely proper motion companion, GSC 00568-01752, which lies 48.''9 away (a projected separation of 2600 AU) and has Sloan Digital Sky Survey and Two Micron All Sky Survey colors consistent with an early M dwarf. We calculate a photometric distance to GSC 00568-01752 of 53 {+-} 15 pc, in good agreement with our distance estimate for SDSS J2249+0044AB. The space motion of SDSS J2249+0044AB shows no obvious coincidence with known young moving groups, though radial velocity and parallax measurements are necessary to refine our analysis. The unusually red near-IR colors, young age, and low masses of the binary make it an important template for studying planetary-mass objects found by direct imaging surveys.« less
Free radical-based annulation of alkenes yielding fused cycloheptanones

Abstract Stereospecific annulation of cyclic alkenes for the preparation of cis-fused seven-membered ring systems was accomplished by sequential [2 + 2] cycloaddition, exo-allylation, hydrohalogenation, and free radical ring expansion. The new strategy extends our recently developed cyclobutanone-based ring expansion reactions.
Referendum Contingent Valuation Estimates: Sensitivity to the Assignment of Offered Values

Abstract Contingent valuation methods (CVM) are becoming increasingly popular for assessing the value of nonmarket resources and public goods. In particular, CVM “willingness to pay” estimates are gaining currency for the assessment of damages in environmental litigation. Several studies have compared the value estimates resulting from alternative formats used for CVM survey questions and have speculated on the reasons for observed discrepancies. These reasons now include a whole taxonomy of possible biases. We take a closer look at one CVM format—the referendum—and demonstrate that simply the “luck of the draw” in assigning the referendum thresholds on individual questionnaires can produce a surprisingly wide variety of value estimates. We control for the behavioral biases that confound other comparison studies by using one sample of “payment card” CV data and simulating 200 samples of consistent referendum responses. Due to the inefficiency of the referendum format, we conclude that, where referendum qu...
Customers improve the quality of training

Customers are learning that the quality of training DCS vendors provide is an important product differentiator. DCS vendors who provide high quality training institute fundamental processes to (1) identify and analyze customer training requirements, (2) develop “lean” training that is specifically directed to meet the customer's requirements, (3) ensure that what is developed actually meets the identfied requirements, and (4) monitor the quality of training and implement prevention-based corrective action where appropriate to continuously improve the quality of their training.
High-redshift voids in the excursion set formalism

Voids are a dominant feature of the low-redshift galaxy distribution. Several recent surveys have found evidence for the existence of large-scale structure at high redshifts as well. We present analytic estimates of galaxy void sizes at redshifts z ∼ 5-10 using the excursion set formalism. We find that recent narrow-band surveys at z ∼ 5-6.5 should find voids with characteristic scales of roughly 20 comoving Mpc and maximum diameters approaching 40 Mpc. This is consistent with existing surveys, but a precise comparison is difficult because of the relatively small volumes probed so far. At z ∼ 7-10, we expect characteristic void scales of ∼ 14-20 comoving Mpc assuming that all galaxies within dark matter haloes more massive than 10 10 M ⊙ are observable. We find that these characteristic scales are similar to the sizes of empty regions resulting from purely random fluctuations in the galaxy counts. As a result, true large-scale structure will be difficult to observe at z ∼ 7-10, unless galaxies in haloes with masses ≤10 9 M ⊙ are visible. Galaxy surveys must be deep and only the largest voids will provide meaningful information. Our model provides a convenient picture for estimating the 'worst-case' effects of cosmic variance on high-redshift galaxy surveys with limited volumes.
Palladium-Catalyzed γ-Arylation of α,β-Unsaturated Esters from Silyl Ketene Acetals

The palladium-catalyzed coupling of enolates with aryl and vinyl electrophiles has become a useful method for the construction of carbon–carbon bonds.[1] Although many palladium complexes have been identified that catalyze the coupling of enolates of ketones, esters, amides, and aldehydes with haloarenes, the vinylogous coupling of dienolates of α,β-unsaturated carbonyl compounds with haloarenes (γ-arylation) has been less studied. γ-Aryl α,β-unsaturated carbonyl compounds are useful building blocks because they can be further functionalized at the carbonyl or olefinic positions.[2]
Photochemistry of trivinylboranes: Preparation of anti-adducts of hydroboranes and alkynes☆

Abstract Trivinylboranes, which are conveniently prepared from the addition of diborane to acetylenes, are found to readily undergo photochemical Z/E isomerization. Since the chromaphore of the E-isomer is highly twisted by steric strain, photochemical conditions can completely convert the Z-isomer to the E-isomer. This high yield, two step process, provides an efficient procedure to bring about an anti-addition of hydroboranes to acetylenes.
Development of a compact X-ray linear light source and FEL at UCLA

Abstract There is a need for a new type of light source that provides subpicosecond, extremely intense X-ray burst for biological and chemical studies. The development of a system that uses a very bright electron source, bunch rotation, a high-gradient accelerating structure and an advanced undulator to produce this light source (LLS) is described. The possibility of operating the LLS in an FEL mode and present calculations on the required performance of each component in the LLS for this purpose is illustrated. The construction of the components at UCLA is outlined. This article concludes with a discussion of the high-gradient accelerator structure and undulator system being developed jointly with Pulse Sciences Incorporated and Rocketdyne and the prospects for future compact X-ray FEL light sources using this technique.
Topography of small Martian valleys

Abstract Small valleys are common in the ancient highlands of Mars. Valley widths are typically a few kilometers and are independent of length for valleys longer than about 50 km. Topographic profiles across several representative small valleys, produced using one-dimensional photoclinometry, have smoothly curved shapes and valley-side slopes of 10°-20°. Profiles of unusual valleys from Maumee Valles, the flanks of Alba Patera, and "softened" terrain also have slopes of 10°-20°, but the profiles of Maumee Valles are more V-shaped than those of the typical small valleys, while the profiles of the "softened" valley have proportionately longer upslope convexities. Depths from 15 to 800 m are measured for the small martian valleys and most valleys have depths between 20 and 250 m. The mean depth-to-width ratio from 135 measurements of 45 different valleys is 0.08 (standard deviation 0.04). When valley profiles with uneven rims are excluded, the mean depth-to-width ratio is 0.07 (standard deviation 0.03). Applying the lower ratio to the widths of a larger sample of small valleys yields depths that are almost all between 40 and 300 m. The majority of the small valleys we have studied are probably the result of groundwater sapping, and in this context the measured valley depths imply that liquid water was often less than a few hundred meters below the surface in the vicinity of these valleys at the time early in martian history when the valleys formed.
Neutrino astronomy: An update

Abstract Detecting neutrinos associated with the still enigmatic sources of cosmic rays has reached a new watershed with the completion of IceCube, the first detector with sensitivity to the anticipated fluxes. In this review, we will briefly revisit the rationale for constructing kilometer-scale neutrino detectors and summarize the status of the field.
An asymmetric oxazoline ketenimine rearrangement. Construction of chiral α-quaternary carbon ketones

Abstract A novel asymmetric oxazoline ketenimine rearrangement has been observed to construct α-quaternary substituted ketones. Levels of asymmetric induction in the ketones, of up to 87% ee, were observed for this unusual rearrangement.
Syntheses of highly-functionalized polyhedral oligosilsesquioxanes

Abstract The hydrolytic condensation of p-ClCH2C6H4SiCl3 in aqueous acetone affords [p-ClCH2C6H4SiO3/2]8 (1), a synthetically useful precursor for the syntheses of octafunctional polyhedral oligosilsesquioxanes [p-XCH2C6H4SiO1.5]8, including 2 (X = I), 3 (X = OH), 4 (X = ONO2), 5 (X = OAc), 6 (X = p-nitrobenzoyl), and 7 (X = methylterephthaloyl).
Image retrieval via isotropic and anisotropic mappings

Abstract This paper presents an approach for content-based image retrieval via isotropic and anisotropic mappings. Isotropic mappings are defined as mappings invariant to the action of the planar Euclidean group on the image space—invariant to the translation, rotation and reflection of image data, and hence, invariant to orientation and position. Anisotropic mappings, on the other hand, are defined as those mappings that are correspondingly variant. Structure extraction (via a perceptual grouping process) and color histogram are shown to be representations of isotropic mappings. Texture analysis using a channel energy model comprised of even-symmetric Gabor filters is considered to be a representation of anisotropic mapping. An integration framework for these mappings is developed. Results of retrieval of outdoor images by query and by classification using a nearest neighbor classifier are presented.
Operating characteristics and a priori probability of the signal

Two experiments in auditory signal detection produced changes in the operating characteristic as the a priori probability of signal occurrence, p(SN), was varied. The signal was a sinusoid of 1,000 Hz presented for 250 msec against a continuous background of noise. In Experiment 1 three values of p(SN)—0.25, 0.50, and 0.75—were paired with each of three signal intensities. In Experiment 2 the signal intensity was fixed and p(SN) was assigned values of 0.10, 0.25, 0.50, 0.75, and 0.90. On normal-normal coordinates, operating characteristics were fitted to the points obtained from the 4-point rating scale used by the listeners. Such operating characteristics may be specified by two parameters: ds, an index of detectability related to d’, and m, its slope. While ds was found to be independent ofp(SN), m was found to be a joint function of p(SN) and signal intensity. These results are discussed against the background of the theory of signal detectability.
Case Studies in U. S. Distance Education: Implications for Ghana's Under-Served High Schools

Ghana, like many other nations in recent years, has made education a top priority for national development. Despite newly developed policies, however, there remains a significant quality gap among high schools; due largely to an inequitable ratio of government’s educational spending by geographic area. While most urban schools flourish with better funding and more resources, many rural schools are substandard due to funding inequity, inadequate infrastructure, and lack of logistical support, material input, and qualified teachers. These problems call for attention and resolution and distance education is considered a panacea to these problems. To achieve this objective, three distance education sites/cases—two parochial schools and one large state-supported public school were studied. Using a variety of data collection interview methods—video conferencing, Skype, face-to-face conversations, and e-mail—interviews were conducted with individuals representing various roles at the three case study sites in the United States: teachers, principals, local and district administrators, and technical and program directors. Effective and ineffective practices at these focus sites provided contextual referencing for future program development/replication in Ghana. Interviews revealed many common issues and themes for success in facilities/program development, program management, and instructional delivery. Recommendations and a model for online distributed education emerged to aid in addressing Ghana’s educational needs. The study findings can inform other systems, nationally and internationally, though the study specifically emphasized concerns in Ghana—where quality education is needed to better prepare under-served school populations for higher education and for further contribution to the development and prosperity of that nation.
Prevention of cardiovascular outcomes in type 2 diabetes mellitus: trials on the horizon

This article focuses on the continuing clinical trials in patients who have diabetes mellitus and pre-diabetes mellitus in which cardiovascular disease outcomes-specifically, myocardial infarction, stroke, and cardiovascular death-are examined as primary outcomes.
First order semianalytic satellite theory with recovery of the short period terms due to third body and zonal perturbations

Perturbation theory is applied to the satellite orbit problem to recover in an analytic method the short period terms due to perturbations by the Sun, Moon and the zonal harmonics of the Earth. The perturbation analysis is carried out by means of Lie series and is developed through the first order only. The Hamiltonian is obtained, the short period terms are eliminated and the generating function W is found by integration. From W the coordinates are defined from the Lie series by a transformation equation. These coordinates are nonsingular for small eccentricity. Secular, long and medium period effects are treated using the method of averaging. The singly averaged equations are expanded to high order in the parallax factor. Motion of the third body is included in the analysis. The result is a very fast and accurate semianalytic ephemeris generator. Numerical examples are given.
Multi-core implementation of decomposition-based packet classification algorithms

Multi-field packet classification is a network kernel function where packets are classified based on a set of predefined rules. Decomposition-based classification approaches are of major interest to the research community because of the parallel search in each packet header field. This paper presents four decomposition-based approaches on multi-core processors. We search in parallel for all the fields using linear search or range-tree search; we store the partial results in a linked list or a bit vector. The partial results are merged to produce the final packet header match. We evaluate the performance with respect to latency and throughput varying the rule set size (1---64 K). Experimental results show that our approaches can achieve 128 ns latency per packet and 11.5 Gbps throughput on state-of-the-art 16-core platforms.
High-nuclearity oxomolybdenum(V) complexes

Abstract During the past decade, a new family of high nuclearity oxometalates has emerged, oxomolybdenum(V) complexes whose d-electrons are localized in Mov-Mov bonds. The structure types of all known complexes in this family are reviewed, including nine different (Mov-Mov monomer, dimer, trimer, tetramer, hexamer, and octadecamer structures, with an emphasis on high-nuclearity structures. In each case, oxomolybdenum(V) core structures are identified and analyzed with regard to degree of polymerization, degree of condensation, and oxygen packing, and an effort is made to identify smaller complexes as subunits of larger structures.
A vortex-lattice method for calculating longitudinal dynamic stability derivatives of oscillating delta wings

A nonsteady vortex-lattice method is introduced for predicting the dynamic stability derivatives of a delta wing undergoing an oscillatory motion. The analysis is applied to several types of small oscillations in pitch. The angle of attack varied between + or - 1 deg, with the mean held at 0 deg when the flow was assumed to be attached and between + or - 1 deg and the mean held at 15 deg when both leading-edge separation and wake roll-up were included. The computed results for damping in pitch are compared with several other methods and with experiments, and are found to be consistent and in good agreement.
Outer Approximation of the Spectrum of a Fractal Laplacian

We present a new method to approximate the Neumann spectrum of a Laplacian on a fractal K in the plane as a renormalized limit of the Neumann spectra of the standard Laplacian on a sequence of doma...
Radiotherapy Planning Complexity and Survival after Treatment of Advanced Stage Lung Cancer in the Elderly.

BACKGROUND: Complex radiotherapy (RT) planning is increasingly common in the treatment of lung cancer, although it remains unclear if these treatments are associated with better outcomes. The authors evaluated the association between the complexity of RT planning simulation and survival among elderly patients with stage IIIB non-small-cell lung cancer (NSCLC). METHODS: The authors included all patients aged >65 years with histologically confirmed stage IIIB NSCLC diagnosed between 1992 and 2002 who were receiving chemotherapy and RT from the Surveillance, Epidemiology, and End Results registry linked to Medicare claims. Patients were divided into simple, intermediate, and complex RT planning groups using Medicare physician codes. Kaplan-Meier curves and Cox regression were used to compare overall and lung cancer-specific survival rates across groups. RESULTS: The authors identified 1733 patients: 148 (8%), 1138 (66%), and 447 (26%) were classified as having received simple, intermediate, and complex RT planning, respectively. Baseline characteristics were similar across groups. Increasing complexity of RT planning was significantly associated with better overall survival (P = .0002). Multivariate analyses showed that intermediate (hazards ratio [HR], 0.75; 95% confidence interval [95% CI], 0.62-0.91) and complex planning (HR, 0.69; 95% CI, 0.55-0.86) were associated with better overall survival compared with simple RT planning. Similar results were observed for lung cancer-specific survival analyses. Toxicities were comparable across groups. CONCLUSIONS: The use of more complex RT planning and simulation methods is associated with better survival in elderly patients with stage IIIB NSCLC. Although these results should be further validated in prospective clinical trials, these data suggest that complex planning may improve the outcomes of these patients. Cancer 2009. © 2009 American Cancer Society.
Gallium Arsenide Integrated Optical Devices In Adverse Environments

We discuss preliminary measurements of the response of gallium arsenide integrated optical waveguides to radiation from a Febetron. The Febetron produces electrons in the 300-700 keV rangelA in approximately 3-ns FWHM pulses, with a maximum dose rate of approximately 10 rad/sec. "Prompt" radiation effects were monitored on a streak camera recording system.
Diabetes and peripheral arterial disease in men: trends in prevalence, mortality, and effect of concomitant coronary disease.

Background Recent data on trends in diabetes mellitus (DM) prevalence and long-term effect on mortality in peripheral arterial disease (PAD) subjects is lacking. Methods All subjects discharged from any VA medical center between October 1990 to September 1997 with an International Classification of Diseases (ICD)-9 code for PAD and DM in the discharge summary were retrospectively identified. Demographic data were extracted from the database. Mortality data were obtained from the Beneficiary Information and Resource Locator. Outcome measures were age specific DM prevalence over time, and short-term and long-term mortality. Results Of 33, 629 patients with PAD, 9474 (29%) had DM. Diabetes mellitus subjects were less likely to be white and had more comorbidities. Mean length of hospital stay was greater for DM (22.3 d vs 18.7 days, P < 0.001). Mortality was higher for DM at 180 days (9.8% vs 8.4%, P < 0.001), 1 year (16.4% vs 13.7%, P < 0.001), and continues to increase at 8 years of follow-up. Logistic regression analysis showed no interaction between DM and coronary artery disease (CAD). Conclusions Diabetes mellitus increases all-cause mortality in subjects with PAD starting at 6 months post-discharge and continues to be higher even at 8 years of follow-up. There was a lack of interaction of DM and CAD on mortality in this cohort of subjects with PAD. Copyright © 2009 Wiley Periodicals, Inc.
Federal Administrative and Judicial Oversight of Medicaid: Policy Legacies and Tandem Institutions under the Boren Amendment

Because of the active role assumed by the courts in Medicaid nursing facility reimbursement, and because that role changed over time, federal intervention in this area provides a useful window through which to examine the role of the federal judiciary in oversight of state health policy making. Findings support the proposition that because judicial influence extends beyond program outcomes to include the organizational structure and beliefs of key stakeholder groups, the effects of case decisions, and the statutes under which they are litigation, may be deeper and longer lasting than their usefulness as a litigation tool. Findings also support the proposition that neither the executive nor the judiciary acts in isolation but instead they serve as tandem institutions guiding federal oversight of state policy making. Data for this analysis derive from archival documents, secondary sources, and 101 in-depth interviews.
Effects of natural aging on the tensile properties of water-quenched U-6%Nb alloy

Abstract Uranium–6 wt% niobium (U–6%Nb) alloy has been in use for many years in the water-quenched (WQ) condition. The purpose of this work was to determine the effect of natural aging on tensile properties of the WQ U–6%Nb alloy. The materials studied were hemispherical shells after 15 and 20 years in storage. The alloy was successfully tested in the original curved configuration, using the specially designed tensile test apparatus. Finite element analysis confirmed the validity of the test method. The results of the tensile tests clearly indicated that in the WQ condition, the material is changing and after 15 and 20 years, the yield strength exceeds the original maximum allowable specification. The fracture mode transitions from highly ductile, microvoid coalescence in new material to a mixed mode of shallow dimples and inclusion-induced voids in the naturally aged material.
Evidence on the returns to secondary vocational education

Vocational education in high schools has frequently been stigmatized as an anachronistic, dead-end path for students. We use data from the National Education Longitudinal Survey of 1988 to examine claims that students on a vocational track would benefit from a more academically rigorous education. Clearly, selection bias confounds attempts to untangle the effects of academic tracking on income after high school. Using an econometric framework that accounts for this bias, we find evidence of comparative advantage in tracking.
Testing The Consistency of Nested Logit Models with Utility Maximization

Abstract This paper provides simple necessary conditions for testing the local consistency of nested logit models with stochastic utility maximization. A graphical analysis illustrates the extent to which these conditions extend the range of admissible dissimilarity coefficients beyond the unit interval.
Noncircular pores on the surface of asymmetric polymer membranes: evidence of pore formation via spinodal demixing

Abstract To investigate the origin of noncircular pores in the selective layer of asymmetric poly(vinylidene fluoride) (PVDF), membranes cast by immersion precipitation, the mass transfer kinetics were controlled by casting membranes at different temperatures and casting solution concentrations. Interconnected surface pore morphologies were observed by scanning electron microscopy (SEM) for membranes cast at high concentration and/or temperature, supporting a mechanism of liquid–liquid demixing at the membrane surface by spinodal decomposition. The coarsening of this highly porous, interconnected morphology leads first to chain-like formations of discreet, noncircular pores and ultimately to scattered pores of circular shape and large size dispersity. Similar results for poly(sulfone) (PSF), membranes, which solidify via vitrification rather than crystallization, suggest a degree of universality in the mechanism of morphological development of asymmetric membrane surfaces. This new understanding of pore formation kinetics opens the possibility of tailoring membrane surfaces to achieve a high degree of porosity and pore size uniformity.
OH Masers in G11.904–0.141

The massive star-forming region G11.904-0.141 is one of only 11 sources to show maser emission in the highly excited 13441 MHz transition of OH. VLBA observations of the 1665, 1667, 4765, and 13441 MHz transitions of OH toward G11.904-0.141 are presented. Masers are detected at 1665, 1667, and 4765 MHz, but the 13441 MHz masers are not detected. Consistent magnetic field strengths of approximately +3.5 mG are detected in the ground-state masers, in contrast with a possible -3.0 mG magnetic field previously detected at 13441 MHz. The variable 13441 MHz masers may be associated with an outflow.