cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis and characterization of higher generation dendrons based on melamine using p-aminobenzylamine. Evidence for molecular recognition of Cu(II)

Abstract The difference in nucleophilicity between the amines of p -aminobenzylamine can be used to synthesize dendrimers based on melamine using a convergent, orthogonal approach. The resulting molecules comprise groups that donate and accept hydrogen-bonds, limiting synthetic accessibility due to intermolecular aggregation. Dendrons with molecular weights exceeding 10 kDa can be prepared by this strategy, but yields drop off significantly at the highest generation (D5) due to difficulties in purification. The addition of Cu(II) reduces the extent of aggregation as evident in SEC traces. UV–vis spectroscopy confirms recognition.
Crystalline Protein Domains and Lipid Bilayer Vesicle Shape Transformations

Cellular membranes can take on a variety of shapes to assist biological processes including endocytosis. Membrane-associated protein domains provide a possible mechanism for determining membrane curvature. We study the effect of tethered streptavidin protein crystals on the curvature of giant unilamellar vesicles (GUVs) using confocal, fluorescence, and differential interference contrast microscopy. Above a critical protein concentration, streptavidin domains align and percolate as they form, deforming GUVs into prolate spheroidal shapes in a size-dependent fashion. We propose a mechanism for this shape transformation based on domain growth and jamming. Osmotic deflation of streptavidin-coated GUVs reveals that the relatively rigid streptavidin protein domains resist membrane bending. Moreover, in contrast to highly curved protein domains that facilitate membrane budding, the relatively flat streptavidin domains prevent membrane budding under high osmotic stress. Thus, crystalline streptavidin domains are shown to have a stabilizing effect on lipid membranes. Our study gives insight into the mechanism for protein-mediated stabilization of cellular membranes.
Reconstruction of an Obstacle Inside a Planar Domain from Boundary Measurements

Abstract We reconstruct a two-dimensional obstacleDfrom knowledge of its Dirichlet-to-Neumann map on the boundary of a domain enclosingD. To do so, we first prove existence and uniqueness of exponentially growing solutions to an exterior problem which is of independent interest.
Preservation of viable corneal tissue.

Advances in corneal transplantation have created a demand for increasing numbers of donor corneas. The organization of eye banks has aided in overcoming this need, but the rigid time requirements placed on donor corneas have hampered efforts to utilize all of the donor material available, and to supply it to remote areas. Dead tissue can be used for lamellar transplants and can be stored by dehydration and other techniques, but most patients require penetrating keratoplasties and, for this, the endothelium must be alive. The development of a practical method for preserving corneal cells alive, for extended periods, at low temperatures, will eliminate the time requirement and enable more tissue to be used for penetrating keratoplasty both in this country, and in areas where corneal tissue is now unavailable. In addition, studies of donor endothelium in bank eyes indicate a high proportion of abnormalities in the older age group, and tissue
Structure and high-temperature thermoelectric properties of SrAl2Si2

Single crystals of SrAl_2Si_2 were synthesized by reaction of the elements in an aluminum flux at 1000 °C. SrAl_2Si_2 is isostructural to CaAl2Si2 and crystallizes in the hexagonal space group P–3m1 (90 K, a=4.1834 (2), c=7.4104 (2) A, Z=1, R1=0.0156, wR2=0.0308). Thermal analysis shows that the compound melts at 1020 °C. Low-temperature resistivity on single crystals along the c-axis shows metallic behavior with room temperature resistivity value of 7.5 mΩ cm. High-temperature Seebeck, resistivity, and thermal conductivity measurements were made on hot-pressed pellets. The Seebeck coefficient shows negative values in entire temperature range decreasing from −78 μV K^(−1) at room temperature to −34 μV K^(−1) at 1173 K. Seebeck coefficients are negative indicating n-type behavior; however, the temperature dependence is consistent with contribution from minority p-type carriers as well. The lattice contribution to the thermal conductivity is higher than for clathrate structures containing Al and Si, approximately 50 mW cm^(−1) K, and contributes to the overall low zT for this compound.
Dynamic traffic grooming algorithms for reconfigurable SONET over WDM networks

The emergence of wavelength-division multiplexing (WDM) technology provides the capability for increasing the bandwidth of synchronous optical network (SONET) rings by grooming low-speed traffic streams onto different high-speed wavelength channels. Since the cost of SONET add-drop multiplexers (SADM) at each node dominates the total cost of these networks, how to assign the wavelength, groom the traffic, and bypass the traffic through the intermediate nodes has received a lot of attention from researchers recently. Moreover, the traffic pattern of the optical network changes from time to time. How to develop dynamic reconfiguration algorithms for traffic grooming is an important issue. In this paper, two cases (best fit and full fit) for handling reconfigurable SONET over WDM networks are proposed. For each approach, an integer linear programming model and heuristic algorithms (TS-1 and TS-2, based on the tabu search method) are given. The results demonstrate that the TS-1 algorithm can yield better solutions but has a greater running time than the greedy algorithm for the best fit case. For the full fit case, the tabu search heuristic yields competitive results compared with an earlier simulated annealing based method and it is more stable for the dynamic case.
The Minimum Universal Metal Density between Redshifts of 1.5 and 5.5

It appears that the Lyα forest is becoming thick at a redshift of about 5.5, cutting off the higher redshift intergalactic medium from view in neutral hydrogen. However, the effects of star formation at higher redshift are still readable in the intergalactic metal lines. In this Letter, I use observations of 32 quasars with emission redshifts in the range 2.31-5.86 to study the evolution of the intergalactic metal density from z = 1.5 to z = 5.5. The C IV column density distribution function is consistent with being invariant throughout this redshift range. From direct integration, I determine ΩC iv to be in the range (2.5-7) × 10-8 and ΩSi iv in the range (0.9-3) × 10-8 between z = 1.5 and z = 5. The metallicity at z = 5 exceeds 3.5 × 10-4, which in turn implies that this fraction of the universal massive star formation took place beyond this redshift. This is sufficient to have ionized the intergalactic medium.
Re-inventing Willis

Scientists often re-invent things that were long known. Here we review these activities as related to the mechanism of producing power law distributions, originally proposed in 1922 by Yule to explain experimental data on the sizes of biological genera, collected by Willis. We also review the history of re-invention of closely related branching processes, random graphs and coagulation models.
A theory of computer instructions

Just as there is a theory of groups, or rings, or fields, or topological spaces, so there is presented here a theory of computer instructions. These are functions from S to S, where S is the set of states of a computer. Here S is a set of functions from M to B, where M is the memory (the set of variables) and B is a set of values; or alternatively, S is a cartesian product, over M as an index set, of the sets of values of all variables in M. For each instruction I there are defined the input region IR(I) and the output region OR(I); these are subsets of M. An instruction takes data from its input region and places data in its output region. Here OR(I) may be decomposed further into regions affected by subsets of M, which may be defined in either of two alternative ways. The theory presented here includes theorems concerning composition of instructions, decomposition of instructions, and the existence of instructions with specified regions. Many examples are given.
Transition to Traveling Waves from Standing Waves in a Rectangular Container Subjected to Horizontal Excitations

We report an unexpected observation of a transition to traveling waves from standing waves. The waves are two dimensional and generated in a rectangular container excited by a horizontal sinusoidal motion along its length. The transition to traveling waves clearly indicates coupling between modes whose natural frequencies do not satisfy obvious resonance conditions. The observed phenomenon is beyond our current understanding of surface waves based on low-dimensional models and demands further study. It implies that care must be taken in developing approximate low-dimensional models for continuous systems in the presence of nonlinearity.
Active control of oxygen in molten lead–bismuth eutectic systems to prevent steel corrosion and coolant contamination

The thermodynamic basis for controlling oxygen level in lead–bismuth to prevent steel corrosion and coolant contamination is examined. The operational conditions, including the thermodynamic activity of oxygen, cover gas oxygen partial pressure, mixtures of H2 and H2O (steam) to obtain such low oxygen partial pressure (<10−24 atm or around 10−6 wt% in lead–bismuth), and the voltage signals of one type of oxygen sensors (with a solid electrolyte and molten bismuth reference electrode) are calculated. These results provide the guidance to implement the oxygen control technique.
Small carbon clusters: spectroscopy, structure, and energetics.

III. Formation of Carbon Clusters 2317 IV. Thermodynamic Properties 2319 V. C2 2319 A. Structure and Spectroscopy 2319 B. C2 2320 C. C2 2321 VI. C3 2321 A. Early Experimental Work 2321 B. Mid-IR and Far-IR Spectroscopy 2321 C. Electronic Spectroscopy 2323 1. The Σu + Ground State 2323 2. The AΠu State 2324 3. The Σu + State 2324 4. The aΠu and bΠg States 2325 5. Other Band Systems 2326 D. C3 in the Interstellar Medium 2326 E. C3 2326 F. C3 2327 VII. C4 2327 A. Theory 2327 B. Experiment 2328 1. The Rhombic Isomer 2328 2. The Linear Isomer 2328 C. Excited Electronic States 2330 D. C4 2331 E. C4 2332 VIII. C5 2332 A. Theory 2332 B. Experiment 2332 C. Excited Electronic States 2334 D. C5 2334 E. C5 2335 IX. C6 2335 A. Theory 2335 B. Experiment 2336 1. The Cyclic Isomer 2336 2. The Linear Isomer 2336 C. Excited Electronic States 2337 D. C6 2338 E. C6 2338 X. C7 2338 A. Theory 2338 B. Experiment 2338 C. Excited Electronic States 2340 D. C7 2340 E. C7 2340 XI. C8 2341 A. Theory 2341 B. Experiment 2342 1. The Cyclic Isomer 2342 2. The Linear Isomer 2342 C. Excited Electronic States 2342 D. C8 2342 E. C8 2342 XII. C9 2343 A. Theory 2343 B. Experiment 2343 C. Excited Electronic States 2345 D. C9 2345 E. C9 2345 XIII. C1
Resolving the p + = 0 ambiguity in a homogeneous electric background

Abstract I present an exact solution for the Heisenberg picture, Dirac electron in the presence of an electric field which depends arbitrarily upon the light cone time parameter x+ = (t + x)/√2. This is the largest class of background fields for which the mode functions have ever been obtained. The solution applies to electrons of any mass and in any spacetime dimension. The traditional ambiguity at p+ = 0 is explicitly resolved. It turns out that the initial value operators include not only (I + γ0γ1)ψ at x+ = 0 but also (I − γ0γ1)ψ at x− = −L. Pair creation is a discrete and instantaneous event on the light cone, so one can compute the particle production rate in real time. In D = 1 + 1 dimensions one can also see the anomaly. Another novel feature of the solution is that the expectation value of the current operators depends nonanalytically upon the background field. This seems to suggest a new, strong phase of QED.
Pedogenesis and paleoclimatic implications of the Chamberlain Pass Formation, Basal White River Group, Badlands of South Dakota

Abstract The Chamberlain Pass Formation is a new lithostratigraphic unit representing the first phase of deposition of the Paleogene White River Group in western South Dakota. Analysis of pedogenic features within the channel and overbank deposits of the Chamberlain Pass Formation allows for a refinement of Middle to Late Eocene paleoclimates of this area. Pedogenic features within distal overbank deposits of the Chamberlain Pass Formation have long been recognized and classified as the Interior Paleosol Series ( Retallack, 1983 ). Previous interpretations held that distal overbank sediments and soils of this time were deposited and formed under humid, acidic environments. This research demonstrates that, while this interpretation is correct, soils of the Chamberlain Pass Formation were also subjected to periods of dryness. Pedogenic features preserved within the channel sandstone and proximal overbank deposits (which include root traces, peds, cutans, glaebules, Bt, Btc and Bc horizons, silcretes and altered detrial sandstone mineralogy) suggest the formation of Aqualfs, Aquults and Durixerults. Soils appear to have been acidic to slightly alkaline, oxidizing and moderately-to well-drained, depending upon the physiographic position of the soil and the prevailing climate at the time of formation. Soils formed within the channel and proximal overbank deposits represent a new soil series, herein designated as the Weta Paleosol Series. The Weta and Interior Paleosol Series have a catenary soil relationship, based on differences in parent material and soil moisture conditions. Middle to Late Eocene paleoclimate appears to have fluctuated between humid and dry conditions. Within the Weta Paleosol Series, soils formed within one physiographic and climatic regime were successively overprinted by pedogenic features of soils formed during later periods under different physiographic and climatic regimes. This has resulted in the presence of humid climate soil pedorelicts in dry climate soils, dry climate pedorelicts within humid climate soils and the overlapping of various physiogrpahically controlled pedogenic processes as baselevels changed. Sediments of similar pedostratigraphic and lithostratigraphic arrangement can be found in Nebraska, northern South Dakota and North Dakota. The recognition of these similar sediments in different basins across the northern Great Plains may allow for an increased understanding of regional tectonic, depositional, climatic and geomorphic events during the Paleogene.
Laboratory stabilization/solidification of surrogate and actual mixed-waste sludge in glass and grout

Abstract Grout and glass formulations were developed for the stabilization of highly radioactive tank sludges. These formulations were tested in the laboratory with a surrogate and with a sample of an actual mixed waste tank sludge. The grout formulation was tested at wet-sludge loadings of 50–60 wt%, giving a volume increase of about 40–50 vol%. Dried sludge was vitrified into glass at waste oxide loadings of 40–50 wt%, giving a volume decrease of about 50–60 vol%. The Resource Conservation and Recovery Act (RCRA) metals included in surrogate testing were Ag, Ba, Cd, Cr, Ni, Pb, Se, Tl and Hg. Since vitrification would volatilize, not stabilize mercury, it was not included in the surrogates vitrified. The actual sludge sample was only characteristically hazardous for mercury by the toxic characteristic leaching procedure (TCLP) but exceeded the Universal Treatment Standard (UTS) limit for chromium. The grout and glass formulations stabilized these RCRA metals within UTS limits. In addition, a grout leachability index of about 9–10 was measured for both 85 Sr and 137 Cs, meeting the recommended requirement of >6. The glass leachability index was estimated to be >18 for cold cesium and strontium.
Benzannulation via the Reaction of Ynamides and Vinylketenes. Application to the Synthesis of Highly Substituted Indoles

A two-stage “tandem strategy” for the synthesis of indoles with a high level of substitution on the six-membered ring is described. Benzannulation based on the reaction of cyclobutenones with ynamides proceeds via a cascade of four pericyclic reactions to produce multiply substituted aniline derivatives in which the position ortho to the nitrogen can bear a wide range of functionalized substituents. In the second stage of the tandem strategy, highly substituted indoles are generated via acid-, base-, and palladium-catalyzed cyclization and annulation processes.
A traveling wave approach to plasma pumping for X-ray sources

Progress in high-brightness excimer lasers and in optical angular multiplexing of excimer lasers presents an opportunity to provide very intense pumping of X-ray sources, both in favorable geometry and in traveling waves, all at low cost. The traveling-wave strategy can be tailored to the parameters of the system to be pumped. This design option can be of great importance for systems lasing at wavelengths in the kilovolt regime where upper level lifetimes are short, and where mirror technology is presently tenuous. Features of several design strategies are explored.
Advances in understanding Alzheimer's disease, and the contributions of current Alzheimer research: ten years on and beyond.

The initial issue of Current Alzheimer Research (CAR) was first published in 2004, a year marked by the glories of the Athens Summer Olympics as well as the destruction of the Asian Tsunami[1]. Over the last decade, scientific knowledgehas moved rapidly forward across numerous disciplines,marked by the discovery of the potential for water and life on Mars [2,3], the generation of the first induced pluripotent stem cells [4], the creation of the first cell controlled by a synthetic genome [5], and genome editing [6].In the realm of dementia -now, beyond the centennial of the first presentation by Alois Alzheimer on the disease that bears his name [7]–important changes too have occurred in the past decade. Whereas the exact prevalence of dementia remains unknown, it is crystal clear that dementia is a common, devastating and costly condition amongst the elderly. The WHO 2012 Report “Dementia: a public health priority” [8] estimatesthat 35.6 million people suffered with dementia worldwide in 2010. An estimated incidence that is much higher than that approximatedin 2004 (18 million people [9]),and this value has undoubtedly grown still more in 2014.
Differentiation of SRB states for hyperbolic flows

Let the ${\cal C}^3$ vector field ${\cal X}+aX$ on $M$ define a flow $(f^t_a)$ with an Axiom A attractor $\Lambda_a$ depending continuously on $a\in(-\epsilon,\epsilon)$. Let $\rho_a$ be the SRB measure on $\Lambda_a$ for $(f^t_a)$. If $A\in{\cal C}^2(M)$, then $a\mapsto\rho_a(A)$ is ${\cal C}^1$ on $(-\epsilon,\epsilon)$ and $d\rho_a(A)/da$ is the limit when $\omega\to0$ with ${\rm Im}\omega>0$ of $$ \int_0^\infty e^{i\omega t}dt \int\rho_a(dx) X(x)\cdot\nabla_x(A\circ f_a^t) $$
Pitt’s inequality with sharp convolution estimates

Sharp L P extensions of Pitt's inequality expressed as a weighted Sobolev inequality are obtained using convolution estimates and Stein-Weiss potentials. Optimal constants are obtained for the full Stein-Weiss potential as a map from L P to itself which in turn yield semi-classical Rellich inequalities on R n . Additional results are obtained for Stein-Weiss potentials with gradient estimates and with mixed homogeneity. New proofs are given for the classical Pitt and Stein-Weiss estimates.
One-stage-push-back operation for congenital insufficiency of the palate.

Abstract An additional operative step in the technique of the push-back operation for congenitally short palate is described. This step consists of the removal of a portion of the posterior wall of the bony pterygopalatine canal, thus permitting easy backward displacement of the mucoperiosteal flap and the soft palate. By this step the blood supply and inervation of the palate are preserved. The procedure permits satisfactory lengthening of the palate by a one-stage operation. The operation may be applied to cases in which there is congenital insufficiency of the palate without cleft as well as to cases in which there is shortening of the palate in association with incomplete or complete clefts.
Exchange-correlation functional based on the density matrix

I present an exchange-correlation functional which incorporates the off-diagonal components of the one-electron density matrix. The functional is derived within tight-binding theory from interpolation between well-established limits, using a rigorous inequality. The functional, unlike the local-density approximation, obtains charge quantization for isolated atoms, fluctuating-dipole interactions, and Hubbard-gap effects. The results should greatly expand the range of problems treatable by ab initio simulations.
β-Silyl carbenes

Abstract β-Trimethylsilyl carbenes rearrange to form alkenes by facile migration of the β-silyl group. In the norbornyl system, β-hydrogen migration can also compete with silyl migration.
Structure‐Property Relations in Lanthanide Borate Glasses

Glass formation in the system Ln2O3-B2O3 (Ln = Nd, Sm) was studied. Glasses could be formed in the range from 0 to 28 mol pct rare-earth oxide (Ln2O3), but liquid immiscibility in these systems limits the range of homogeneous glasses to 0 to 1.5 and 25 to 28 mol pct Ln2O3. The infrared spectra indicate that the rare-earth-rich glasses are structurally similar to rare-earth metaborates (LnB3O6) which contain (B3O6)-infinity chains. The variation in density, transformation temperature, thermal expansion coefficient, and transformation-range viscosity of these glasses with the size of the rare-earth ion is discussed. Glasses near the metaborate composition have a transformation temperature of about 700 C, which is high for binary borate glasses. Glasses could not be formed in the systems Eu2O3-, Gd2O3-, Ho2O3-, and Er2O3-B2O3, even by quenching at 1300 C/s. The sudden lack of glass formation in the system Ln2O3-B2O3 with Ln(3+) ions smaller than Sm(3+) is explained on the basis of the size effect of the Ln(3+) ion on the stability of (B3O6)-infinity chains in these metaborates.
Two-photon excitation of atomic oxygen

A standard perturbation expansion in the atom-radiation field interaction is used to calculate the two photon excitation cross section for 1s(2) 2s(2) 2p(4) p3 to 1s(2) 2s(2) 2p(3) (s4) 3p p3 transition in atomic oxygen. The summation over bound and continuum intermediate states is handled by solving the equivalent inhomogeneous differential equation. Exact summation results differ by a factor of 2 from a rough estimate obtained by limiting the intermediate state summation to one bound state. Higher order electron correlation effects are also examined.
A geometric consistency theorem for a symbolic perturbation scheme

Abstract In a previous paper, we introduced a generic solution to the problem of data degeneracy in geometric algorithms. The scheme is simple to use: algorithms qualifying under our requirements just have to use a prescribed blackbox for polynomial evaluation in order to achieve a symbolic perturbation of data. In this paper, we introduce the concept of an infinitesimal perturbation and show that our method is consistent relative to such perturbations.
Direct forecasting of subsurface flow response from non-linear dynamic data by linear least-squares in canonical functional principal component space

Abstract Inverse modeling is widely used to assist with forecasting problems in the subsurface. However, full inverse modeling can be time-consuming requiring iteration over a high dimensional parameter space with computationally expensive forward models and complex spatial priors. In this paper, we investigate a prediction-focused approach (PFA) that aims at building a statistical relationship between data variables and forecast variables, avoiding the inversion of model parameters altogether. The statistical relationship is built by first applying the forward model related to the data variables and the forward model related to the prediction variables on a limited set of spatial prior models realizations, typically generated through geostatistical methods. The relationship observed between data and prediction is highly non-linear for many forecasting problems in the subsurface. In this paper we propose a Canonical Functional Component Analysis (CFCA) to map the data and forecast variables into a low-dimensional space where, if successful, the relationship is linear. CFCA consists of (1) functional principal component analysis (FPCA) for dimension reduction of time-series data and (2) canonical correlation analysis (CCA); the latter aiming to establish a linear relationship between data and forecast components. If such mapping is successful, then we illustrate with several cases that (1) simple regression techniques with a multi-Gaussian framework can be used to directly quantify uncertainty on the forecast without any model inversion and that (2) such uncertainty is a good approximation of uncertainty obtained from full posterior sampling with rejection sampling.
Vacuum Tunneling by Cosmic Strings

Abstract We consider vacuum tunneling of a new kind where the false vacua are not translationally invariant, but have topological defects that break some of their translational symmetries. In the particular case where the topological defects are cosmic strings, we show the existence of an O (2) × O (2) symmetric bounce configuration that allows a semiclassical estimate of the rate of cosmic string induced tunneling. A method of reduction is then suggested for simplifying the computation of the bounce action. Some phenomenological applications are described.
The science and politics of ecological risk: bioinvasions policies in the US and Australia

The US and Australia – western democracies with similar histories of public awareness on environmental issues and broadly comparable records of policy and regulatory action to safeguard environmental quality – have responded differently to one of the newest and most significant threats to marine bioidiversity: that of biological invasions mediated by the ballast water of commercial shipping. Each country has framed the same invasion risks differently for the purposes of policy and regulation: Australia has decided to use a more narrowly circumscribed, target-species-based approach whereas US policy and regulation takes a more comprehensive and precautionary approach. These somewhat surprising national regulatory choices are traced to differences in the structure of each country's process for ballast policy decision making and most importantly to the policy role of ecological expertise within this process.
High performance nanophotonic circuits based on partially buried horizontal slot waveguides

We present a novel platform to construct high-performance nanophotonic devices in low refractive index dielectric films at telecoms wavelengths. The formation of horizontal slots by PECVD deposition of high index amorphous silicon provides a convenient and low-cost way to tailor nanophotonic devices to application needs. Low propagation loss of less than 2 dB/cm is obtained allowing us to fabricate optical resonators with measured high optical quality factors exceeding 105. We design and experimentally demonstrate on-chip grating couplers to efficiently couple light into integrated circuitry with coupling loss of 4 dB and optical bandwidth exceeding 110 nm. The entire on-chip circuitry consisting of input/output couplers, Mach-Zehnder interferometers with high extinction ratio and ring, racetrack resonators are designed, fabricated and characterized.
Dealing with logical omniscience: Expressiveness and pragmatics

We examine four approaches for dealing with the logical omniscience problem and their potential applicability: the syntactic approach, awareness, algorithmic knowledge, and impossible possible worlds. Although in some settings these approaches are equi-expressive and can capture all epistemic states, in other settings of interest (especially with probability in the picture), we show that they are not equi-expressive. We then consider the pragmatics of dealing with logical omniscience-how to choose an approach and construct an appropriate model.
Dual-action inhibitors of proteolytic enzymes: potential therapeutic agents for cystic fibrosis and related ailments

Abstract The design, synthesis and in vitro inhibitory activity toward human leukocyte elastase of a series of dual action saccharin derivatives are described.
MEASUREMENT OF MAGNETIC FLUCTUATION INDUCED ENERGY TRANSPORT

The local electron energy flux produced by magnetic fluctuations has been measured directly in the MST reversed field pinch (over the radial range r/a > 0.75). The flux, produced by electrons traveling parallel to a fluctuating magnetic field, is obtained from correlation between the fluctuations in the parallel heat flux and the radial magnetic field. The fluctuation induced flux is large (100 kW/cm{sup 2}) in the ``core`` (r/a < 0.85) and small (< 10--30 kW/cm{sup 2}) in the edge.
Intra-Endodermal Interactions Are Required for Pancreatic β Cell Induction

The cellular origin of signals that regulate pancreatic β cell induction is not clearly defined. Here, we investigate the seeming paradox that Hedgehog/Smoothened signaling functions during gastrulation to promote pancreatic β cell development in zebrafish, yet has an inhibitory role during later stages of pancreas development in amniotes. Our cell transplantation experiments reveal that in zebrafish, Smoothened function is not required in β cell precursors. At early somitogenesis stages, when the zebrafish endoderm first forms a sheet, pancreatic β cell precursors lie closest to the midline; however, the requirement for Smoothened lies in their lateral neighbors, which ultimately give rise to the exocrine pancreas and intestine. Thus, pancreatic β cell induction requires Smoothened function cell-nonautonomously during gastrulation, to allow subsequent intra-endodermal interactions. These results clarify the function of Hedgehog signaling in pancreas development, identify an unexpected cellular source of factors that regulate β cell specification, and uncover complex patterning and signaling interactions within the endoderm.
Cytogenetic and clinical features of placental moles: synopsis and update.

Abstract Abnormalities of fertilization are responsible for two types of placental moles. This synopsis of the two syndromes includes definition, relative incidence, mechanism of fertilization, and clinical course. Controversy regarding the comparative course has diminished with the recognition that partial moles can have sequelae requiring chemotherapy, although less frequently than complete moles. An important subgroup of complete moles is dispermic and heterozygous (usually 46, XY), and these have a disproportionately high rate of postmolar complications. Recommendations are made for routine cytogenetic study of moles in order to foster precision in classification and search for heterozygosity in complete moles. A technique is given for isolation and promotion of growth in vitro of molar trophoblastic cells. Additional information about the two syndromes is needed, a challenge for cytogeneticists.
AN ASSESSMENT OF A METRIC SPACE DATABASE INDEX TO SUPPORT SEQUENCE HOMOLOGY

Hierarchical metric-space clustering methods have been commonly used to organize proteomes into taxonomies. Consequently, it is often anticipated that hierarchical clustering can be leveraged as a basis for scalable database index structures capable of managing the hyper-exponential growth of sequence data. M-tree is one such data structure specialized for the management of large data sets on disk. We explore the application of M-trees to the storage and retrieval of peptide sequence data. Exploiting a technique first suggested by Myers, we organize the database as records of fixed length substrings. Empirical results are promising. However, metric-space indexes are subject to "the curse of dimensionality" and the ultimate performance of an index is sensitive to the quality of the initial construction of the index. We introduce new hierarchical bulk-load algorithm that alternates between top-down and bottom-up clustering to initialize the index. Using the Yeast Proteomes, the bi-directional bulk load produces a more effective index than the existing M-tree initialization algorithms.
Near-wall turbulence structures in three-dimensional boundary layers

We examine the structure of near-wall turbulence in three-dimensional boundary layers (3DBLs), which we approximate by applying an impulsive spanwise motion to the lower wall of a turbulent channel flow. Direct numerical simulation (DNS) data are analysed using probability density functions (PDFs), conditional-averaged quadrant analysis about Reynolds-stress-producing events, and visualization of vortices with the ?2-criterion. The evidence suggests that mean three-dimensionality breaks up the symmetry and alignment of near-wall structures, disrupting their self-sustaining mechanisms, and thereby causing a reduction in the turbulence kinetic energy (TKE).
Regionalism in the Western Hemisphere and Its Impact on U.S. Agricultural Exports: A Gravity-Model Analysis

The last fifteen years of the twentieth century were marked by important achievements in the area of agricultural trade liberalization in the Western Hemisphere. In North America, Canada, Mexico, and the United States forged the North American Free Trade Agreement (NAFTA). This accord, which took effect on 1 January 1994, is dismantling most tariff and non-tariff barriers for trading between its members. NAFTA also incorporates the Canada-U.S. Free Trade Agreement (CFTA), an accord similar to NAFTA that took effect
SDAFT: A novel scalable data access framework for parallel BLAST

Abstract In order to run tasks in a parallel and load-balanced fashion, existing scientific parallel applications such as mpiBLAST introduce a data-initializing stage to move database fragments from shared storage to local cluster nodes. Unfortunately, with the exponentially increasing size of sequence databases in today’s big data era, such an approach is inefficient. In this paper, we develop a scalable data access framework to solve the data movement problem for scientific applications that are dominated by “read” operation for data analysis. SDAFT employs a distributed file system (DFS) to provide scalable data access for parallel sequence searches. SDAFT consists of two interlocked components: (1) a data centric load-balanced scheduler (DC-scheduler) to enforce data-process locality and (2) a translation layer to translate conventional parallel I/O operations into HDFS I/O. By experimenting our SDAFT prototype system with real-world database and queries at a wide variety of computing platforms, we found that SDAFT can reduce I/O cost by a factor of 4–10 and double the overall execution performance as compared with existing schemes.
Quantum Particle Swarm Optimization for Electromagnetics

A new particle swarm optimization (PSO) technique for electromagnetic applications is proposed. The method is based on quantum mechanics rather than the Newtonian rules assumed in all previous versions of PSO, which we refer to as classical PSO. A general procedure is suggested to derive many different versions of the quantum PSO algorithm (QPSO). The QPSO is applied first to linear array antenna synthesis, which is one of the standard problems used by antenna engineers. The performance of the QPSO is compared against an improved version of the classical PSO. The new algorithm outperforms the classical one most of the time in convergence speed and achieves better levels for the cost function. As another application, the algorithm is used to find a set of infinitesimal dipoles that produces the same near and far fields of a circular dielectric resonator antenna (DRA). In addition, the QPSO method is employed to find an equivalent circuit model for the DRA that can be used to predict some interesting parameters like the Q-factor. The QPSO contains only one control parameter that can be tuned easily by trial and error or by suggested simple linear variation. Based on our understanding of the physical background of the method, various explanations of the theoretical aspects of the algorithm are presented
Precipitation and Condensation of Organic Particles

The precipitation and condensation of submicron organic particles are reviewed. The importance of physical state effects is discussed, and the role of compartmentalization in controlling particle s...
Deficiency of decidual IL-10 in first trimester missed abortion: a lack of correlation with the decidual immune cell profile.

PROBLEM: To determine if first trimester missed abortion decidua is characterized by an altered immune cell profile and/or a modified interleukin (I L)-10 and interferon (IFN)-gamma production pattern compared with decidua from elective termination. METHOD OF STUDY: Flow cytometry and immunohistochemistry techniques were used to determine the decidual immune cell phenotypic profile and production pattern of IL-10 and IFN-gamma in cases of elective termination (n = 14) and missed abortion (n = 12). RESULTS: Both groups had a similar proportion of CD56(+) CD16(-),CD56(+) CD16(+), CD19(+), CD3(+), CD4(+), CD8(+), alphabeta T cells and gammadelta T cells. The majority of alphabeta and gammadelta positive T cells in both groups coexpressed the natural killer (NK) cell marker CD56, but lacked cell surface expression of CD3. Diminished decidual IL-10 staining was noted in 7/10 missed abortion cases compared with none of the elective termination cases (n = 12) (P = 0.007). A uniform decidual IFN-gamma staining pattern was observed in both groups. CONCLUSION: Decreased IL-10 production coupled with a sustained IFN-gamma presence noted in missed abortion compared with elective termination cases suggest that these cytokines may be important determinants in pregnancy outcome. In contrast, differences in the proportion of immune cells between both groups may not be a critical factor in early pregnancy loss. In normal pregnancy, decidual alphabeta and gammadelta positive T cells with reduced CD3 on their cell surface may be intrinsically restricted in T-cell receptor (TCR)-mediated activation.
Preparation and Characterization of Aluminum Borate

Aluminum borate, 9Al2O3·2B2O3 or Al18B4O33, was synthesized by the reaction of stoichiometric amounts of α-Al2O3 and B2O3. The Al18B4O33 material was formed into a dense ceramic by pressureless sintering with CaO, MgO, or CaAl2B2O7 additives. The material was characterized by low bulk density, moderate coefficient of thermal expansion (3 × 10−6/°C to 5 × 10−6/°C), moderate strength (210 to 324 MPa), and low dielectric constant.
A parallel implementation of a multi-state Kalman filtering algorithm to detect ECG arrhythmias.

Detecting arrhythmias from the electrocardiogram (EGG) is of great importance for the continued development of intelligent cardiovascular monitors (ICM). An ICM's main goal is to present to the clinician a ‘high-level’ analysis of the patient's condition (e.g., the patient is slightly hypovolemic) based upon ‘lowlevel’ physiologic signals (e.g., blood pressure, heart rate, etc.). This paper reports on a parallel implementation of a multi-state Kalman filtering algorithm, within a prototype ICM, to help detect ECG arrhythmias. Preliminary test results show that the parallel, multi-state implementation performed exactly as the original sequential version. Several different rhythm disturbances were correctly identified after 3–5 beats. We conclude that our parallel implementation of the multi-state Kalman filter provides a faster and still reliable means of accurately detecting ECG arrhythmias in real-time.
Space-time singularities and the axion in the Poincaré coset models ISO(2,1)/H

Abstract By promoting an invariant subgroup H of ISO (2, 1) to a gauge symmetry of a WZWN action, we obtain the description of a bosonic string moving either in a curved 4-dimensional space-time with an axion field and curvature singularities or in 3-dimensional Minkowski space-time.
Surfacing by numbers

We present a novel technique for surface modelling by example called surfacing by numbers. Our system allows easy detail reuse from existing 3D models or images. The user selects a source region and a target region, and the system transfers detail from the source to the target. The source may be elsewhere on the target surface, on another surface altogether, or even part of an image. As transfer is formulated as synthesis with a novel surface-based adaptation of graph cuts, the source and target regions need not match in size or shape, and details can be geometric, textural or even user-defined in nature.A major contribution of our work is our fast, graph cut-based interactive surface segmentation algorithm. Unlike approaches based on scissoring, the user loosely strokes within the body of each desired region, and the system computes optimal boundaries between regions via minimum-cost graph cut. Thus, less precision is required, the amount of interaction is unrelated to the complexity of the boundary, and users do not need to search for a view of the model in which a cut can be made.
Parametric Study of a Gas Turbine

Gas Turbine Laboratories and Texas A and M University demonstrated how to evaluate a gas turbine by analyzing the basic cycle and developing techniques to evaluate field performance and plan maintenance scheduling. The evaluation begins by outlining the various cycles available and the performance of each, and continues with techniques and equations which can be used in the field to provide a fast and accurate check on the performance of these units. The diagnostic methods presented identified the parameters to be monitored in the combustor section as turbine exhaust temperature and in the compressor and turbine sections as inlet and exhaust temperature and pressure, temperature and pressure of the lube system, and shaft vibrations. The report covers problems such as compressor approaching surge, surging, fouling, and inspection and maintenance scheduling, as well as turbine inspection, fouling, blade damage, nozzle bowing, cooling-air flow rate, and maintenance scheduling, and their effect on the above parameters. Analysis of each method shows that the concept of equivalent engine hours should help maintenance, and phase shift calculation should allow users to pinpoint combustor problems.
SHRIMP U-Pb dating of zircon from the Xugou UHP eclogite, Sulu terrane, eastern China

Eclogites, together with garnet clinopyroxenites, occur as lenses within the Xugou garnet peridotite body in the southern Sulu ultrahigh-pressure (UHP) terrane. Combined cathodoluminescence (CL) imaging and SHRIMP U-Pb dating of zircon from two Xugou mafic eclogites provide added constraints on the timing of UHP metamorphism in this area. Zircons from both samples show subrounded to rounded shapes and patchy CL patterns without inherited igneous cores, indicating that they are metamorphic zircons. SHRIMP U-Pb analyses of these zircons yielded apparent U-Pb ages of 214-280 Ma, with a weighted mean age of 237 ± 8 Ma, which is consistent with previous reported UHP metamorphic ages from eclogite pods and country-rock gneisses. The Xugou mafic lenses may have formed by partial melting of the enclosing peridotites in the mantle before subduction (Zhang et al., 2003); then these eclogites, together with the host peridotites, were tectonically emplaced into the subduction zone and subjected to UHP metamorphism at...
Smoothness of Loewner slits

In this paper, we show that the chordal Loewner differential equation with $C^{\beta}$ driving function generates a $C^{\beta + 1/2}$ slit for $1/2 < \beta \leq 2$, except when $\beta = 3/2$ the slit is only proved to be weakly $C^{1,1}$.
An Insider View: Knowledge and Opinions of Welfare From African American Girls in Poverty

This article presents African American adolescent girls' views of welfare and welfare reform at the cusp of welfare legislation in 1996. Interview data from a random sample of poor and low-income families indicate that adolescents have a limited knowledge of basic welfare rules. Low-income girls see welfare as an important safety net, yet they also have negative views of welfare recipients and the effects of welfare on recipients. The vast majority express agreement with work requirements, and about half believe that a discontinuation of welfare would change adolescent sexual and childbearingbehaviors. These results raise the possibility that adolescents are responding to the rhetoric and “signals” of welfare reform; alternatively, they may simply be expressing typical adolescent egocentrism and optimism.
Simultaneous microscopic imaging of elastic and thermal anisotropy

Simultaneous imaging of elastic and thermal properties of anisotropic materials with micron (lateral) and nanometer (depth) resolution is presented. This approach employs an ultrafast laser for the generation and detection of thermal and acoustic waves. Demonstrations involving the visualization of thermal waves and surface acoustic waves are presented for single crystal quartz and fused silica substrates sputter coated with chromium films. These images dramatically reveal and contrast the symmetry of thermal and elastic properties and compare favorably with theoretical prediction. This hybrid approach shows great promise to investigate fundamental properties of materials and interfaces on both a low-frequency (elastic wave) and a high-frequency (phonon diffusion) scale.
Key Durability Issues With Mullite-Based Environmental Barrier Coatings for Si-Based Ceramics

Plasma-sprayed mullite (3Al2O3.2SiO2) and mullite/yttria-stabilized-zirconia (YSZ) dual layer coatings have been developed to protect silicon -based ceramics from environmental attack. Mullite-based coating systems show excellent durability in air. However, in combustion environments, corrosive species such as molten salt or water vapor penetrate through cracks in the coating and attack the Si-based ceramics along the interface. Thus the modification of the coating system for enhanced crack-resistance is necessary for long-term durability in combustion environments. Other key durability issues include interfacial contamination and coating/substrate bonding. Interfacial contamination leads to enhanced oxidation and interfacial pore formation, while a weak coating/substrate bonding leads to rapid attack of the interface by corrosive species, both of which can cause a premature failure of the coating. Interfacial contamination can be minimized by limiting impurities in coating and substrate materials. The interface may be modified to improve the coating/substrate bond.
Selective oxoammonium salt oxidations of alcohols to aldehydes and aldehydes to carboxylic acids.

The oxidation of alcohols to aldehydes using stoichiometric 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (1) in CH2Cl2 at room temperature is a highly selective process favoring reaction at the carbinol center best able to accommodate a positive charge. The oxidation of aldehydes to carboxylic acids by 1 in wet acetonitrile is also selective; the rate of the process correlates with the concentration of aldehyde hydrate. A convenient and high yield method for oxidation of alcohols directly to carboxylic acids has been developed.