cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis of anthraquinonyl glucosaminosides and studies on the influence of aglycone hydroxyl substitution on superoxide generation, DNA binding, and antimicrobial properties

A series of anthraquinonyl glucosaminosides (10a-e) were synthesized by Koenigs-Knorr glycosidation of the corresponding aglycones (11a-e) with bromo sugar 12 followed by saponification. These glycosides were intended to serve as models to study the role played by the hydroxyl substituents on the aglycone portion of the antitumor anthracycline antibiotics. Superoxide generation as measured in rat heart sarcosomes was found to increase with the addition of successive hydroxyl groups to the anthraquinone nucleus. The 1,8-dihydroxy pattern was determined to generate significantly less superoxide than the 1,4-dihydroxy pattern. Hydroxyl substitution was also observed to stabilize the complex formed between the anthraquinones and DNA and was required for antibacterial activity against a number of Gram-positive organisms.
Telescopes versus Microscopes: the puzzle of iron-60

The discovery that the short-lived radionucleide 60Fe was present in the oldest meteorites suggests that the formation of the Earth closely followed the death of a massive star. I discuss three astrophysical origins: winds from an AGB star, injection of supernova ejecta into circumstellar disks, and induced star formation on the boundaries of HII regions. I show that the first two fail to match the solar system 60Fe abundance in the vast majority of star forming systems. The cores and pillars on the edges of HII regions are spectacular but rare sites of star formation and larger clumps with masses 103-4 M๏ at tens of parsec from a supernova are a more likely birth environment for our Sun. I also examine γ-ray observations of 60Fe decay and show that the Galactic background could account for the low end of the range of meteoritic measurements if the massive star formation rate was at least a factor of 2 higher 4.6 Gyr ago.
Alkali Metal Space Power Technology Applicable to National Energy Research and Development

The nation's space power program developed an alkali metal technology potentially applicable to its future energy needs. The space power system was designed to utilize a nuclear reactor with a primary lithium loop and a secondary boiling/condensing potassium loop driving a potassium vapor turbine/electrical generator. Considerable design, manufacture, test, and evaluation efforts were expended in the successful demonstration of the boilers, condensers, turbines, seals, valves, pumps, and other components. Much of that high-temperature, Rankine cycle technology can be used as a basis for advanced power conversion systems; these might include fossil and nuclear fueled plants, central solar power systems or solar power satellites.
Synthesis of chiral carbocyclic ribonucleotides.

Abstract The carbocyclic analogs of CMP, UMP, GMP, IMP, and ribo-TMP, of the same absolute configuration as the naturally occurring β- D-ribofuranose-based ribonucleoside monophosphates, have been synthesized. The synthetic route employed Mitsunobu coupling of the heterocycles, appropriately protected where necessary, with a differentially protected, chiral carbocyclic core.
New Year's res-illusions: food shopping in the new year competes with healthy intentions.

Objective How do the holidays – and the possible New Year’s resolutions that follow – influence a household’s purchase patterns of healthier foods versus less healthy foods? This has important implications for both holiday food shopping and post-holiday shopping. Methods 207 households were recruited to participate in a randomized-controlled trial conducted at two regional-grocery chain locations in upstate New York. Item-level transaction records were tracked over a seven-month period (July 2010 to March 2011). The cooperating grocer’s proprietary nutrient-rating system was used to designate “healthy,” and “less healthy” items. Calorie data were extracted from online nutritional databases. Expenditures and calories purchased for the holiday period (Thanksgiving-New Year’s), and the post-holiday period (New Year’s-March), were compared to baseline (July-Thanksgiving) amounts. Results During the holiday season, household food expenditures increased 15% compared to baseline ($105.74 to $121.83; p<0.001), with 75% of additional expenditures accounted for by less-healthy items. Consistent with what one would expect from New Year’s resolutions, sales of healthy foods increased 29.4% ($13.24/week) after the holiday season compared to baseline, and 18.9% ($9.26/week) compared to the holiday period. Unfortunately, sales of less-healthy foods remained at holiday levels ($72.85/week holiday period vs. $72.52/week post-holiday). Calories purchased each week increased 9.3% (450 calories per serving/week) after the New Year compared to the holiday period, and increased 20.2% (890 calories per serving/week) compared to baseline. Conclusions Despite resolutions to eat more healthfully after New Year’s, consumers may adjust to a new “status quo” of increased less-healthy food purchasing during the holidays, and dubiously fulfill their New Year’s resolutions by spending more on healthy foods. Encouraging consumers to substitute healthy items for less-healthy items may be one way for practitioners and public health officials to help consumers fulfill New Year’s resolutions, and reverse holiday weight gain.
Single Molecule Kv2.1 Channel Dynamics in Live Mammalian Cells

Neuronal Kv2.1 potassium channels localize into micron-sized clusters which are regulated by extracellular glutamate and intracellular Ca2+ levels. The physical mechanisms underlying the formation and maintenance of these unique structures are largely unknown. We are investigating the dynamics of clustered Kv2.1 channels using high resolution total internal reflection fluorescence microscopy (TIRFM) to track single molecules with 8 nm accuracy.Transfected human embryonic kidney (HEK) cells expressing biotinylated and GFP-tagged Kv2.1 channels are detected with streptavidin-conjugated red quantum dots (QD). While the red QDs enable tracking of individual channels, GFP fluorescence provides characteristics of clusters as an ensemble. The channel dynamics inside Kv2.1 clusters are analyzed in the membrane of live cells in terms of their mean square displacement (MSD) and cumulative distribution function (CDF).In our current model, the actin cytoskeleton plays a dominant role in Kv2.1 cluster formation and maintenance. To test this model we are studying the effects of depolymerization agents such as Cytochalasin and Swinholide A on the individual channel dynamics.Clustered channels remain confined within the cluster perimeter throughout the entire imaging time, up to 25 minutes. MSD analysis indicates similar diffusion constants for clustered and non-clustered channels, D = 0.013 ± 0.017 μm2/s and 0.014 ± 0.011 μm2/s respectively. The CDF of all analyzed trajectories (n=900) deviates from a monoexponential, indicating a discrepancy with Brownian diffusion. Instead, the data can be accurately fit to a double exponential.Our results show a bimodal distribution of channels (clustered and non-clustered) and indicate that both populations experience anomalous subdiffusion. The double exponential term of the CDF suggests two stochastic processes which have slow and fast mobility respectively. Single molecule tracking with simultaneous channel cluster imaging is shown to be an effective way to study the mechanisms underlying clustering phenomena.
Site selectivity in reactions of metal hydride halide complexes with acids

Abstract Protonolysis. protonation and hydrogen bond-formation reactions with metal hydride halide (L n MHX) complexes are reviewed. The site selectivity (hydride vs halide) for these reactions is found to be highly variable, with many examples of either case. In fact, several systems are in equilibrium between protonated (or hydrogen-bonded) hydride and halide ligands. The more reactive site depends primarily on the accessibility of the hydride ligands and the polarity of the metal hydride bonds. Protonation at hydride is a common synthetic method for metal halide dihydrogen complexes. M(H 2 )X, which are rather well represented. In contrast, halide protonation gives metal hydride (hydrogen halide) complexes. MH(XH), for which only a few examples are established. However, H…X bonding in M(H 2 )X complexes, “invisible” to NMR techniques, has generally not been ruled out. The lighter halides form stronger hydrogen bonds, and are more prone to protonation than the heavier halides. Thus, fluoride is the best halide ligand for electrophilic removal, while iodide ligands are best suited to withstand acidic conditions.
Periodic Optimal Hypersonic Scramjet Cruise

Fuel-optimal periodic cruise paths are determined numerically for a hypersonic vehicle with more realistic aerodynamic and scramjet engine models than used in previous work. A modification of the shooting method, called the minimizing-boundary-condition method, is used to increase the region of convergence of the solution to the two-point boundary-value problem required to satisfy the first-order necessary conditions. The resulting extremal trajectories are shown to be locally minimizing by a second-order sufficiency condition. Little fuel improvement is obtained over the full-throttle steady-state cruise if the model with an engine-off-drag penalty is used. However, altitude changes of over 25 per cent from its lowest value on the periodic path are obtained. If the model without engine-off-drag penalty is used, the fuel improvement for the optimal periodic cruise is 5 per cent over the full-throttle steady-state cruise.
Anodically enhanced diffusion in Cu/Ag thin film couples

Thin, 100-nm films of first silver and then copper were deposited consecutively onto pure single-crystal (111) silicon substrates by magneton sputter deposition. Controlled anodic current density was applied at room temperature to dissolve the outer copper film to varying depths approaching the copper/silver interface. Profiles of copper and silver concentration vs. depth below the anodically dissolved surfaces were subsequently obtained by argon ion sputtering and simultaneous Auger Electron Spectroscopy. Despite some intrinsic mixing during the profile analysis, there is clear evidence that diffusion of copper and silver into one another is enhanced by anodic currents at the outer copper surface. Preliminary interpretation leads the authors to believe that the effect is caused by surface formation of vacancies during anodic dissolution. The anodically generated vacancies can migrate as divacancies to the copper/silver interface where they enhance diffusion by the usual vacancy exchange mechanism.
A simple derivation of the JIMWLK equation

A simple derivation of the Jalilian-Marian, Iancu, McLerran, Weigert, Leonidov and Kovner (JIMWLK) equation for the evolution of small-x QCD wavefunctions is given. The derivation makes use of the equivalence between the evolution of a (in general complicated) small x wavefunction with that of the evolution of the (simple) dipole probing the wavefunction in a high energy scattering.
Pharmaceutical‐embodied technical progress, longevity, and quality of life: drugs as ‘Equipment for Your Health’

Several econometric studies have concluded that technical progress embodied in equipment is a major source of manufacturing productivity growth. Other research has suggested that, over the long run, growth in the US economy's ‘health output’ has been at least as large as the growth in non-health goods and services. One important input in the production of health—pharmaceuticals—is even more R&D-intensive than equipment. In this paper, we test the pharmaceutical-embodied technical progress hypothesis—the hypothesis that newer drugs increase the length and quality of life—and estimate the rate of progress. To do this, we estimate health production functions, in which the dependent variables are various indicators of post-treatment health status (such as survival, perceived health status, and presence of physical or cognitive limitations), and the regressors include drug vintage (the year in which the FDA first approved a drug's active ingredient(s)) and indicators of pre-treatment health status. We estimate these relationships using extremely disaggregated—prescription-level—cross-sectional data derived primarily from the 1997 Medical Expenditure Panel Survey. We find that people who used newer drugs had better post-treatment health than people using older drugs for the same condition, controlling for pre-treatment health, age, sex, race, marital status, education, income, and insurance coverage: they were more likely to survive, their perceived health status was higher, and they experienced fewer activity, social, and physical limitations. The estimated cost of the increase in vintage required to keep a person alive is lower than some estimates of the value of remaining alive for 1 month. One estimate of the cost of preventing an activity limitation is $1745, and the annual rate of technical progress with respect to activity limitations is 8.4%. People consuming newer drugs tend to experience greater increases (or smaller declines) in physical ability than people consuming older drugs. Most of the health measures indicate that the effect of drug vintage on health is higher for people with low initial health than it is for people with high initial health. Therefore in contrast to equipment-embodied technical progress, which tends to increase economic inequality, pharmaceutical-embodied technical progress has a tendency to reduce inequality as well as promote economic growth, broadly defined. Copyright © 2007 John Wiley & Sons, Ltd.
Negative Binomial Process Count and Mixture Modeling

The seemingly disjoint problems of count and mixture modeling are united under the negative binomial (NB) process. A gamma process is employed to model the rate measure of a Poisson process, whose normalization provides a random probability measure for mixture modeling and whose marginalization leads to an NB process for count modeling. A draw from the NB process consists of a Poisson distributed finite number of distinct atoms, each of which is associated with a logarithmic distributed number of data samples. We reveal relationships between various count- and mixture-modeling distributions and construct a Poisson-logarithmic bivariate distribution that connects the NB and Chinese restaurant table distributions. Fundamental properties of the models are developed, and we derive efficient Bayesian inference. It is shown that with augmentation and normalization, the NB process and gamma-NB process can be reduced to the Dirichlet process and hierarchical Dirichlet process, respectively. These relationships highlight theoretical, structural, and computational advantages of the NB process. A variety of NB processes, including the beta-geometric, beta-NB, marked-beta-NB, marked-gamma-NB and zero-inflated-NB processes, with distinct sharing mechanisms, are also constructed. These models are applied to topic modeling, with connections made to existing algorithms under Poisson factor analysis. Example results show the importance of inferring both the NB dispersion and probability parameters.
On a Quaternionic Analogue of the Cross-Ratio

In this article we study an exact analogue of the cross-ratio for the algebra of quaternions \({\mathbb{H}}\) and use it to derive several interesting properties of quaternionic fractional linear transformations. In particular, we show that there exists a fractional linear transformation T on \({\mathbb{H}}\) mapping four distinct quaternions q1, q2, q3 and q4 into \({q^{\prime}_{1}, q^{\prime}_{2}, q^{\prime}_{3}}\) and \({q^{\prime}_{4}}\) respectively if and only if the quadruples (q1, q2, q3, q4) and (\({q^{\prime}_{1}, q^{\prime}_{2}, q^{\prime}_{3}, q^{\prime}_{4}}\)) have the same cross-ratio. If such a fractional linear transformation T exists it is never unique. However, we prove that a fractional linear transformation on \({\mathbb{H}}\) is uniquely determined by specifying its values at five points in general position. We also prove some properties of the cross-ratio including criteria for four quaternions to lie on a single circle (or a line) and for five quaternions to lie on a single 2-sphere (or a 2-plane). As an application of the cross-ratio, we prove that fractional linear transformations on \({\mathbb{H}}\) map spheres (or affine subspaces) of dimension 1, 2 and 3 into spheres (or affine subspaces) of the same dimension.
Liver Laceration with Hemoperitoneum after Cardiopulmonary Resuscitation

It is well known that external chest compression during cardiopulmonary resuscitation is frequently associated with various complications. These complications predominantly involve trauma to the heart, lungs, and chest wall, whereas cases involving intra-abdominal injury are much less frequent. The present report describes a rare case of a female patient with severe hemoperitoneum associated with liver injury after cardiopulmonary resuscitation. Although emergent angiography and embolization of the hepatic artery were performed and transfusion of various kinds of blood products was done continuously, the patient expired the next day.
A Survey of Chromospheric Activity in the Solar-Type Stars in the Open Cluster M67*

We present the results of a spectroscopic survey of the Ca II H and K core strengths in a sample of 60 solar-type stars that are members of the solar-age and solar-metallicity open cluster M67. We adopt the HK index, defined as the summed H+K core strengths in 1 A bandpasses centered on the H and K lines, respectively, as a measure of the chromospheric activity that is present. We compare the distribution of mean HK index values for the M67 solar-type stars with the variation of this index as measured for the Sun during the contemporary solar cycle. We find that the stellar distribution in our HK index is broader than that for the solar cycle. Approximately 17% of the M67 Sun-like stars exhibit average HK indices that are less than solar minimum. About 7%-12% are characterized by relatively high activity in excess of solar maximum values, while 72%-80% of the solar analogs exhibit Ca II H+K strengths within the range of the modern solar cycle. The ranges given reflect uncertainties in the most representative value of the maximum in the HK index to adopt for the solar cycle variations observed during the period AD 1976-2004. Thus, ~20%-30% of our homogeneous sample of Sun-like stars have mean chromospheric H+K strengths that are outside the range of the contemporary solar cycle. Any cycle-like variability that is present in the M67 solar-type stars appears to be characterized by periods greater than ~6 yr. Finally, we estimate a mean chromospheric age for M67 in the range of 3.8-4.3 Gyr.
S-Adenosyl-l-methionine: Beyond the universal methyl group donor

S-Adenosyl-l-methionine (AdoMet or SAM) is a substrate in numerous enzyme-catalyzed reactions. It not only provides methyl groups in many biological methylations, but also acts as the precursor in the biosynthesis of the polyamines spermidine and spermine, of the metal ion chelating compounds nicotianamine and phytosiderophores, and of the gaseous plant hormone ethylene. AdoMet is also the source of catalytic 5'-deoxyadenosyl radicals, produced as reaction intermediates by the superfamily of radical AdoMet enzymes. This review aims to summarize the present knowledge of catalytic roles of AdoMet in plant metabolism.
Comparison of etching tools for resist pattern transfer

Several etching tools are evaluated for the oxygen-based plasma pattern transfer step in surface imaging and multilayer resist processes. These tools include a conventional parallel-plate reactive ion etcher, a magnetically enhanced reactive ion etcher, an electron cyclotron resonance reactor, and an rf helical resonator (Helicon) reactor. The performance of each tool is examined with respect to etch rate, etch profile, selectivity between the imaging layer and the pattern transfer layer, etch uniformity, etching residue, linewidth uniformity, and process latitude.
Low-Dimensional Complex Characters of the Symplectic and Orthogonal Groups

We classify the irreducible complex characters of the symplectic groups Sp 2n (q) and the orthogonal groups , Spin 2n+1(q) of degrees up to the bound D, where D = (q n − 1)q 4n−10/2 for symplectic groups, D = q 4n−8 for orthogonal groups in odd dimension, and D = q 4n−10 for orthogonal groups in even dimension.
Status and performance of the CDF Run 2 silicon detectors

Abstract In 2001, an upgraded silicon detector system was installed in the CDF II experiment on the Tevatron at Fermilab. The complete system consists of three silicon micro-strip detectors: SVX II with five layers for precision tracking, Layer 00 with one beampipe-mounted layer for vertexing, and two Intermediate Silicon Layers located between SVX II and the main CDF II tracking chamber. Currently all detectors in the system are operating at or near design levels. The performance of the combined silicon system is excellent in the context of CDF tracking algorithms, and the first useful physics results from the innermost Layer 00 detector have been recently documented. Operational and monitoring efforts have also been strengthened to maintain silicon efficiency through the end of Run 2 at the Tevatron.
Structure and Photoluminescence of a Benzil Nanocolumn in a C-Methylcalix[4]resorcinarene-Based Framework

A new framework based on C-methylcalix[4]resorcinarene and the flexible nonconjugated spacer 1,4-bis(imidazol-1yl-methyl)benzene encloses a large one-dimensional channel, containing benzil nanocolumns. Unlike in a previously reported series of benzil-containing supramolecular solids with conjugated linker molecules, benzil luminescence is observed, but the lifetime of 580 ns at 77 K is considerably shorter than the 145 μs reported for neat benzil at room temperature.
Realistic matched filter performance prediction for hyperspectral target detection

The linear matched filter is widely used in hyperspectral target detection applications. Its detection performance is typically evaluated based on Gaussian (or normal) probability density models. However, it is well known that hyperspectral backgrounds exhibit "long-tail" behavior, which cannot be accurately modeled by normal distributions. In this work, we model the distribution of hyperspectral backgrounds using a more accurate model based on elliptically contoured multivariate t distributions. For the target class, we still use a normal distribution model, because the body of the distribution is important for detection applications. We show that the tails of the background distribution deteriorate the performance of the matched filter. In this sense, performance predictions based exclusively on normal models, which ignore the long tails, can be inaccurate and overly optimistic. The proposed technique, which allows for an easy control of the tail's heaviness, can be a very useful tool for evaluating target detection performance for backgrounds with both light and heavy tails.
Targeted drug delivery to chemoresistant cells: folic acid derivatization of FdUMP[10] enhances cytotoxicity toward 5-FU-resistant human colorectal tumor cells.

Current chemotherapy protocols that include fluoropyrimidines, such as 5-fluorouracil (5-FU), are limited by the development of chemoresistance during the course of treatment. Our laboratory has de...
Detailed Models of Super-Earths: How Well Can We Infer Bulk Properties?

The field of extrasolar planets has rapidly expanded to include the detection of planets with masses smaller than that of Uranus. Many of these are expected to have little or no hydrogen and helium gas, and we might find Earth analogs among them. In this paper we describe our detailed interior models for a rich variety of such massive terrestrial and ocean planets in the 1-10 M⊕ range (super-Earths). The grid presented here allows the characterization of the bulk composition of super-Earths detected in transit and with a measured mass. We show that, on average, planet radius measurements to better than 5%, combined with mass measurements to better than 10%, would permit us to distinguish between an icy or rocky composition. This is due to the fact that there is a maximum radius a rocky terrestrial planet may achieve for a given mass. Any value of the radius above this maximum terrestrial radius implies that the planet contains a large (>10%) amount of water (ocean planet).
Novel applications of alkyl fluorides in organic synthesis: Versatile nitrogen protecting groups

Abstract The potential of the 2-fluoroethyl group as a nitrogen protecting group was demonstrated. The stability of alkyl fluorides, such as 2-fluoroethyl, to a variety of reaction conditions, makes them attractive nitrogen protecting groups. The 2-fluoroethyl group was easily introduced, in good yields, by the treatment of the NH group with potassium carbonate and 2-bromo-1-fluoroethane. Reaction of the 2-fluoroethyl group with boron tribromide resulted in the replacement of fluorine by bromine, to give the corresponding 2-bromoethyl group which was easily removed by known methods.
The Hammer QSD-Quick Stop Device for High Speed Machining and Rubbing

A quick stop device (QSD) was designed for use in orthogonal machining and rubbing experiments. QSD's are used to obtain chip root samples that are representative of the deformation taking place during dynamic (actual) cutting conditions. These 'frozen' specimens are helpful in examining the plastic deformation that occurs in the regions of compression and shear which form the chip; the secondary shear at the tool-chip interface; and the nose ploughing/flank rubbing action which operates on the newly machined surface. The Hammer QSD employs a shear pin mechanism, broken by a flying hammer, which is traveling at the same velocity as the workpiece. The device has been successfully tested up to 6000 sfpm (30.48 m/sec).
Diels―Alder Reactions of Cyclopentadienones with Aryl Alkynes To Form Biaryl Compounds

Diels−Alder reactions of cyclopentadienones, to afford substituted biaryls, were studied using an expanded substrate base. Electron-withdrawing groups on the aryl alkyne dienophile facilitated the reaction, and these substrates gave better yields than those with electron-donating substituents. Steric effects were also found to be important, and o,o′-dimethylphenylacetylene gave much poorer yield of biaryl product.
Fully resolved simulations of particle-turbulence interaction

The interaction between a fixed particle and decaying homogeneous isotropic turbulence is studied numerically using an overset grid that provides resolution of all scales of fluid motion. A description of the numerical technique and validation of the solution procedure are presented. An ensemble of 64 simulations with the particle in different regions of the flow is computed. The particle diameter in the simulations is approximately twice the size of the unladen Kolmogorov length scale, and the maximum value of the particle Reynolds numbers due to the turbulent fluctuations is close to 20. Ensemble averages of quantities from the numerical solutions are used to investigate the turbulence modification and the fluid forces on the particle. Volume-averaged profiles of the turbulent kinetic energy and dissipation rate from the overset grid simulations reveal that the displacement of fluid by the particle and the formation of the boundary layer at the particle surface lead to turbulence modification in a local region. Time histories of the force applied to the particle from each overset grid simulation are compared to those predicted by a particle equation of motion. The particle equation of motion is shown to underpredict the root mean square (RMS) force applied to the particle by the turbulence. RMS errors between the forces from the overset grid simulation and those predicted by the particle equation of motion are shown to be between 15% and 30% of the RMS force on the particle. The steady viscous drag force is shown to be the dominant term in the particle equation of motion while the history integral term is negligible.
Aloe vera: an in vitro study of effects on corneal wound closure and collagenase activity

Purpose To evaluate the in vitro effects of an aloe vera solution on (i) the viability and wound healing response of corneal cells and (ii) the ability to alter collagenase and gelatinase activities. Methods Primary cultures of corneal epithelial cells and fibroblasts were prepared from grossly normal enucleated canine globes and treated with an aloe solution (doses ranging from 0.0–2 mg/mL). Cellular viability was evaluated using a colorimetric assay. A corneal wound healing model was used to quantify cellular ingrowth across a defect made on the confluent surface. Anticollagenase and antigelatinase activities were evaluated by incubating a bacterial collagenase/gelatinase with aloe solution (doses ranging from 0.0–500 μg/mL) and comparing outcome measures to a general metalloproteinase inhibitor, 1, 10-phenanthroline, and canine serum (doses ranging from 0.0–100%). Results None of the concentrations of aloe solution tested significantly affected the viability of corneal epithelial cells or fibroblasts. Concentrations ≤175 μg/mL slightly accelerated corneal epithelial cell wound closure; this change was not significant. Concentrations ≥175 μg/mL significantly (P ≤ 0.001) slowed the rate of corneal fibroblast wound closure, while aloe concentrations <175 μg/mL did not significantly alter fibroblast wound closure. Aloe solution did not alter the ability for collagenase to degrade gelatin or collagen Type I but increased the ability for collagenase to degrade Type IV collagen. Conclusions Although additional experiments are required, lower concentrations of aloe solution may be beneficial in healing of superficial corneal wounds to help decrease fibrosis and speed epithelialization. An increase in collagenase activity with aloe vera warrants further testing before considering in vivo studies.
Intronic deletions in the SLC34A3 gene: A cautionary tale for mutation analysis of hereditary hypophosphatemic rickets with hypercalciuria

Abstract Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a rare metabolic disorder, characterized by hypophosphatemia, variable degrees of rickets/osteomalacia, and hypercalciuria secondary to increased serum 1,25-dihydroxyvitamin D [1,25(OH)2D] levels. HHRH is caused by mutations in the SLC34A3 gene, which encodes sodium-phosphate co-transporter type IIc. A 6-1/2-year-old female presented with a history of nephrolithiasis. Her metabolic evaluation revealed increased 24-hour urine calcium excretion with high serum calcium, low intact parathyroid hormone (PTH), and elevated 1,25(OH)2D. In addition, the patient had low to low-normal serum phosphorus with high urine phosphorus. The patient had normal stature; without rachitic or boney deformities or a history of fractures. Genetic analysis of SLC34A3 revealed the patient to be a compound heterozygote for a novel single base pair deletion in exon 12 (c.1304delG) and 30-base pair deletion in intron 6 (g.1440–1469del). The single-base pair mutation causes a frameshift, which results in premature stop codon. The intronic deletion is likely caused by misalignment of the 4-basepair homologous repeats and results in the truncation of an already small intron to 63 bp, which would impair proper RNA splicing of the intron. This is the fourth unique intronic deletion identified in patients with HHRH, suggesting the frequent occurrence of sequence misalignments in SLC34A3 and the importance of screening introns in patients with HHRH.
The (limited) role of regulatory harmonization in international goods and services markets

With the conclusion of the Uruguay Round and its agreements relating to technical barriers, much attention has been devoted to the possibility of harmonizing international regulatory policies to reduce the impediments to commerce that result from regulatory heterogeneity. This paper argues that, as a normative matter, harmonization is inferior to a legal system that tolerates regulatory differences subject to legal constraints, and that relies on mutual recognition where appropriate (the exception to this claim being matters of technical compatibility between products). Related, as a positive manner, harmonization will often lack any political constituency and thus instances of true harmonization will be rare. To develop these claims, the paper carefully elucidates the unnecessary trade impediments that may result from regulatory heterogeneity, and shows how measures short of harmonization can usually address them adequately. Copyright 1999 by Oxford University Press.
Ceramic-Metal Composite Produced by Melt Infiltration

A new ceramic-metal composite with continuous interconnected ceramic and metal phases has been fabricated from sintered aluminum nitride infiltrated with aluminum metal. A dense, lightweight, hard material with high strength has been obtained. Advance of the infiltration front was linear with time. The activation energy of the process was very high (330 kJ/mol), suggesting that a chemical interaction rather than viscous flow was rate-controlling. The infiltration rate was observed to be inversely proportional to the pore size. Thermal and mechanical properties of the composite were promising.
A signal subspace approach for speech enhancement

A comprehensive approach for nonparametric speech enhancement is developed. The underlying principle is to decompose the vector space of the noisy signal into a signal-plus-noise subspace and a noise subspace. Enhancement is performed by removing the noise subspace and estimating the clean signal from the remaining signal subspace. The decomposition can theoretically be performed by applying the Karhunen-Loeve transform (KLT) to the noisy signal. Linear estimation of the clean signal is performed using two perceptually meaningful estimation criteria. First, signal distortion is minimized while the residual noise energy is maintained below some given threshold. This criterion results in a Wiener filter with adjustable input noise level. Second, signal distortion is minimized for a fixed spectrum of the residual noise. This criterion enables masking of the residual noise by the speech signal. It results in a filter whose structure is similar to that obtained in the first case, except that now the gain function which modifies the KLT coefficients is solely dependent on the desired spectrum of the residual noise. The popular spectral subtraction speech enhancement approach is shown to be a particular case of the proposed approach. It is proven to be a signal subspace approach which is optimal in an asymptotic (large sample) linear minimum mean square error sense, assuming the signal and noise are stationary. Our listening tests indicate that 14 out of 16 listeners strongly preferred the proposed approach over the spectral subtraction approach. >
Embedding, compression and fiberwise homotopy theory

Given Poincar e spaces M and X , we study the possibility of compressing embeddings of MI in XI down to embeddings of M in X. This results in a new approach to embedding in the metastable range both in the smooth and Poincar e duality categories.
A constraint satisfaction approach to the resolution of uncertainty in image interpretation

A technique for image interpretation based on the constraint satisfaction methodology is described. The technique uses an intelligent backtracking algorithm to solve the constraint satisfaction problem and also analyzes failures of the backtracking routine to suggest modifications to help locate a solution. This technique is able to overcome uncertainties in image interpretation by generating partial solutions and inferring values for the missing objects. An outline of this processing is presented and an application of this technique is also given. The technique is compared to another approach in the same domain. Preliminary results on over 1000 test images are included. >
Nash equilibrium in strictly competitive games: live play in soccer

Abstract I model a scoring situation that arises frequently during soccer matches. The Nash equilibrium solution is shown to be broadly consistent with the conventional wisdom of experts. Data on goals scored over an entire season in Italy's soccer league provide statistical support for a prediction of the model's Nash equilibrium.
Efficient and General Synthesis of 3-Aminoindolines and 3-Aminoindoles via Copper-Catalyzed Three-Component Coupling Reaction

An efficient three-component coupling (TCC) reaction toward a variety of 3-aminoindoline and 3-aminoindole derivatives has been developed. This cascade transformation proceeds via the copper-catalyzed coupling reaction between 2-aminobenzaldehyde, a secondary amine, and an alkyne leading to a propargylamine intermediate which, under the reaction conditions, undergoes cyclization into the indoline core. The latter, upon treatment with a base, smoothly isomerizes into the indole. Alternatively, the indole can directly be synthesized in a one-pot sequential reaction.
Visual Function and Cortical Organization in Carriers of Blue Cone Monochromacy

Carriers of blue cone monochromacy have fewer cone photoreceptors than normal. Here we examine how this disruption at the level of the retina affects visual function and cortical organization in these individuals. Visual resolution and contrast sensitivity was measured at the preferred retinal locus of fixation and visual resolution was tested at two eccentric locations (2.5° and 8°) with spectacle correction only. Adaptive optics corrected resolution acuity and cone spacing were simultaneously measured at several locations within the central fovea with adaptive optics scanning laser ophthalmoscopy (AOSLO). Fixation stability was assessed by extracting eye motion data from AOSLO videos. Retinotopic mapping using fMRI was carried out to estimate the area of early cortical regions, including that of the foveal confluence. Without adaptive optics correction, BCM carriers appeared to have normal visual function, with normal contrast sensitivity and visual resolution, but with AO-correction, visual resolution was significantly worse than normal. This resolution deficit is not explained by cone loss alone and is suggestive of an associated loss of retinal ganglion cells. However, despite evidence suggesting a reduction in the number of retinal ganglion cells, retinotopic mapping showed no reduction in the cortical area of the foveal confluence. These results suggest that ganglion cell density may not govern the foveal overrepresentation in the cortex. We propose that it is not the number of afferents, but rather the content of the information relayed to the cortex from the retina across the visual field that governs cortical magnification, as under normal viewing conditions this information is similar in both BCM carriers and normal controls.
Neutron Star Kicks and Asymmetric Supernovae

Observational advances over the last decade have left little doubt that neutron stars received a large kick velocity (of order a few hundred to a thousand kms?1) at birth. The physical origin of the kicks and the related supernova asymmetry is one of the central unsolved mysteries of supernova research. We review the physics of different kick mechanisms, including hydrodynamically driven, neutrino— magnetic field driven, and electromagnetically driven kicks. The viabilities of the different kick mechanisms are directly related to the other key parameters characterizing nascent neutron stars, such as the initial magnetic field and the initial spin. Recent observational constraints on kick mechanisms are also discussed.
THE SPACE MOTION OF LEO I: THE MASS OF THE MILKY WAY'S DARK MATTER HALO

We combine our Hubble Space Telescope measurement of the proper motion of the Leo I dwarf spheroidal galaxy (presented in a companion paper) with the highest resolution numerical simulations of Galaxy-size dark matter halos in existence to constrain the mass of the Milky Way's dark matter halo (M vir, MW). Despite Leo I's large Galactocentric space velocity (200 km s–1) and distance (261 kpc), we show that it is extremely unlikely to be unbound if Galactic satellites are associated with dark matter substructure, as 99.9% of subhalos in the simulations are bound to their host. The observed position and velocity of Leo I strongly disfavor a low-mass Milky Way: if we assume that Leo I is the least bound of the Milky Way's classical satellites, then we find that M vir, MW > 1012 M ☉ at 95% confidence for a variety of Bayesian priors on M vir, MW. In lower mass halos, it is vanishingly rare to find subhalos at 261 kpc moving as fast as Leo I. Should an additional classical satellite be found to be less bound than Leo I, this lower limit on M vir, MW would increase by 30%. Imposing a mass-weighted ΛCDM prior, we find a median Milky Way virial mass of M vir, MW = 1.6 × 1012 M ☉, with a 90% confidence interval of [1.0-2.4] × 1012 M ☉. We also confirm a strong correlation between subhalo infall time and orbital energy in the simulations and show that proper motions can aid significantly in interpreting the infall times and orbital histories of satellites.
Hydrolysis and condensation of silicates: Effects on structure

Abstract The hydrolysis and condensation reactions of monomeric alkoxysilanes and organylalkoxysilanes utilized in sol-gel processing are reviewed. Both reactions occur by acid or base-catalyzed bimolecular displacement reactions. The acid-catalyzed mechanisms are preceded by protonation of OH or OR substituents attached to Si, whereas under basic conditions hydroxyl or silanolate anions attack Si directly. Many of the observed structural trends are understood on the basis of the pH and [H2O] dependence of the hydrolysis, condensation, and dissolution reactions.
Representing braids by automorphisms

Based on a normal form for braid group elements suggested by Dehornoy, we prove several representations of braid groups by automorphisms of a free group to be faithful. This includes a simple proof of the standard Artin's representation being faithful.
A Probabilistic Inequality with Applications to Threshold Direct-Product Theorems

We prove a simple concentration inequality, which is an extension of the Chernoff bound and Hoeffding's inequality for binary random variables. Instead of assuming independence of the variables we use a slightly weaker condition, namely bounds on the co-moments. This inequality allows us to simplify and strengthen several known direct-product theorems and establish new threshold direct-product theorems. Threshold direct-product theorems are statements of the following form: If one instance of a problem can be solved with probability at most p, then solving significantly more than a p-fraction among multiple instances has negligible probability. Results of this kind are crucial when distinguishing whether a process succeeds with probability s or c, for 0 ≪ s ≪ c ≪ 1. Here standard direct-product theorems are of no help since even a process which can solve one instance with probability c will only be able to solve all k instances withe exponentially small probability.
Quasi-periodic Occultation by a Precessing Accretion Disk and Other Variabilities of SMC X-1

We have investigated the variability of the binary X-ray pulsar SMC X-1 in data from several X-ray observatories. We confirm the ~60 day cyclic variation of the X-ray flux in the long-term monitoring data from the RXTE and CGRO observatories. X-ray light curves and spectra from the ROSAT, Ginga, and ASCA observatories show that the uneclipsed flux varies by as much as a factor of 20 between a high-flux state when 0.71 s pulses are present and a low-flux state when pulses are absent. In contrast, during eclipses when the X-rays consist of radiation scattered from circumsource matter, the fluxes and spectra in the high and low states are approximately the same. These observations prove that the low state of SMC X-1 is not caused by a reduction in the intrinsic luminosity of the source or a spectral redistribution thereof, but rather by a quasi-periodic blockage of the line of sight, most likely by a precessing tilted accretion disk. In each of two observations in the midst of low states a brief increase in the X-ray flux and reappearance of 0.71 s pulses occurred near orbital phase 0.2. A similar brief flux increase near orbital phase 0.2 was observed during a low-state observation that did not have sufficient time resolution to detect 0.71 s pulses. These brief increases result from an opening of the line of sight to the pulsar that may be caused by wobble in the precessing accretion disk. The records of spin-up of the neutron star and decay of the binary orbit are extended during 1991-1996 by pulse-timing analysis of ROSAT, ASCA, and RXTE PCA data. The pulse profiles in various energy ranges from 0.1 to greater than 21 keV are well represented as a combination of a pencil beam and a fan beam. Finally, there is a marked difference between the power spectra of random fluctuations in the high-state data from the RXTE PCA below and above 3.4 keV. In the higher energy range the spectrum has a sharp break at 3.3 Hz, with fitted power-law indices of 0.45 and 1.76 below and above the break. No break is evident in the power spectrum below 3.4 keV, and the fitted power-law index is 0.51. In both spectra there is a positive deviation from the fitted power law around 0.06 Hz that may be quasi-periodic oscillation.
Throughput Analysis of Multiple-Bus Multiprocessor Systems with Simultaneous Possession of Common Resources

To answer the questions for the performance issues of multiple-bus multiprocessor systems under general conditions, a discrete-event simulation model has been developed. This model has been analyzed for different types of probability distributions for random variables A = processing times and B = memory access times for processors. For variables A and B, the following types of distributions are employed: exponential, Erlang, hypoexponential, hyperexponential, normal and constant. Simulation experiments show that the coefficient of variation of B, CBhas a significant effect on the system performance, especially for CB>1, but the effect of CA is negligible if A is either hypo- or hyperexponentially distributed. However, this is not the case for a normal distribution.Processing efficiency, memory utilization and the percent of queued processors are some of the performance metrics used in our simulation model. We simulated several multiprocessor configurations and reach the conclusion that if the number of bu...
Synthesis of benzimidazoles from 1,1-dibromoethenes

A mild and efficient method for the preparation of substituted benzimidazoles from 1,1-dibromoethenes and o-diaminobenzenes is described. The reaction employs DABCO as the base and NMP as the solvent. A variety of substitutions on both 2-aryl-1,1-dibromoethenes and o-diaminobenzenes are tolerated. This new procedure is carried out under mildly basic conditions, which may provide a complementary route to the existing preparations of benzimidazoles.
Perceptual image distortion

In this paper, we present a perceptual distortion measure that predicts image integrity far better than mean-squared error. This perceptual distortion measure is based an a model of human visual processing that fits empirical measurements of the psychophysics of spatial pattern detection. The model of human visual processing proposed involves two major components: a steerable pyramid transform and contrast normalization. We also illustrate the usefulness of the model in predicting perceptual distortion in real images. >