cssi/SciSciGPT-SciSciNet huggingface dataset:
Adverse Neonatal Outcomes Associated With Antenatal Dexamethasone Versus Antenatal Betamethasone

OBJECTIVE. Antenatal dexamethasone and betamethasone may not be equally efficacious in the prevention of adverse neonatal outcomes. We compared the risks of periventricular leukomalacia (PVL), intraventricular hemorrhage (IVH), retinopathy of prematurity (ROP), and neonatal death among very low birth weight infants who were exposed to dexamethasone, betamethasone, or neither steroid. METHODS. Infants (401–1500 g) in the National Institute of Child Health and Human Development Neonatal Research Network were studied. Multivariate logistic regression analyses compared the 3 groups with regard to PVL, IVH, ROP, and neonatal death, adjusting for network center and selected covariates. RESULTS. A total of 3600 infants met entry criteria. Compared with no antenatal steroids, there were trends for a reduced risk for PVL associated with dexamethasone and betamethasone but no difference in risk between dexamethasone and betamethasone. Dexamethasone reduced the risk for IVH and severe IVH, compared with no antenatal steroid exposure. Betamethasone reduced the risk for IVH, severe IVH, and neonatal death, compared with no antenatal steroids. Compared with betamethasone, dexamethasone had a statistically significant increased risk for neonatal death. There were trends for greater risks associated with dexamethasone compared with betamethasone for IVH and severe ROP. CONCLUSIONS. Betamethasone was associated with a reduced risk for neonatal death, with trends of decreased risk for other adverse neonatal outcomes, compared with dexamethasone. It may be in the best interest of neonates to receive betamethasone rather than dexamethasone when available.
Identification of incurred sulfonamide residues in eggs: methods for confirmation by liquid chromatography–tandem mass spectrometry and quantitation by liquid chromatography with ultraviolet detection

Abstract Two complementary methods for identifying and measuring sulfonamide residues in eggs were developed for use in surveying eggs for potential drug residues. The first method uses liquid chromatography–tandem mass spectrometry (LC–MS–MS) to confirm the presence of sulfonamide residues in eggs. During its validation the limit of confirmation was estimated to be 5–10 ng/g (ppb) depending on the drug. Also, a method for measuring residue level by liquid chromatography with ultraviolet detection (LC–UV) was validated using the same extraction procedure as the confirmatory method. The determinative method was validated over the 50–200 ppb range. Samples were prepared by homogenizing whole egg, extracting with acetonitrile, and cleaning up with a C18 solid-phase extraction cartridge. For confirmation, analytes were separated by gradient LC on a C18 column, ionized by electrospray ionization (ESI), and detected by MS–MS with an ion trap mass spectrometer. For determination, analytes were separated by a different gradient LC procedure and detected by UV at 287 nm. Fifteen drugs were dosed individually in laying hens, and residues of parent drug and/or metabolites were found in eggs for all the drugs. Validation was based on repetitive analyses of control samples, control samples fortified at 100 ppb sulfonamides, and samples of blended incurred eggs.
Testing Magnetic Star Formation Theory

Zeeman observations of molecular clouds yield the line-of-sight component B LOS of the magnetic vector B, which makes it possible to test the two major extreme-case theories of what drives star formation?ambipolar diffusion or turbulence. However, only one of the three components of B is measurable, so tests have been statistical rather than direct, and they have not been definitive. We report here observations of the Zeeman effect in the 18 cm lines of OH in the envelope regions surrounding four molecular cloud cores toward which detections of B LOS have been achieved in the same lines, and evaluate the ratio of mass-to-magnetic flux, M/?, between the cloud core and envelope. This relative M/? measurement reduces uncertainties in previous studies, such as the angle between B and the line of sight and the value of [OH/H]. Our result is that for all four clouds, the ratios of the core to the envelope values of M/? are less than 1. Stated another way, the ratios of the core to the total cloud M/? are less than 1. The extreme case or idealized (no turbulence) ambipolar diffusion theory of core formation requires the ratio of the central to total M/? to be approximately equal to the inverse of the original subcritical M/?, or 1$ SRC=http://ej.iop.org/images/0004-637X/692/1/844/apj296388ieqn3.gif/>. The probability that all four of our clouds have 1$ SRC=http://ej.iop.org/images/0004-637X/692/1/844/apj296388ieqn4.gif/> is 3 ? 10?7; our results are therefore significantly in contradiction with the hypothesis that these four cores were formed by ambipolar diffusion. Highly super-Alfv?nic turbulent simulations yield a wide range of relative M/?, but favor a ratio , as we observe. Our experiment is limited to four clouds, and we can only directly test the predictions of the extreme-case idealized models of ambipolar-diffusion driven star formation, which have a regular magnetic field morphology. Nonetheless, our experimental results are not consistent with the idealized strong field, ambipolar diffusion theory of star formation. Comparisons of our results with more realistic models and simulations that include both ambipolar diffusion and turbulence may help to refine our understanding of the relative importance of magnetic fields and turbulence in the star formation process.
Compression and localization of an atomic cloud in a time dependent optical lattice

We analyze a method of compressing a cloud of cold atoms by dynamic control of a far off-resonance optical lattice. We show that by reducing the lattice spacing either continuously or in discrete steps while cooling the atoms with optical molasses large compression factors can be achieved. Particle motion in the time-dependent lattice is studied numerically using a three-dimensional semiclassical model. Two experimentally realistic models are analyzed. In the first we continuously vary the lattice beam angles to compress atoms initially in a Gaussian distributed cloud with standard deviation of 250 µm into a single site of a two-dimensional lattice of area A ∼ 35 × 35λ2, with λ the wavelength of the lattice beams. This results in an optical depth for an on-resonant probe beam >80 which is an increase by a factor of about 1800 compared to the uncompressed cloud. In the second approach we use a discrete set of lattice beam angles to decrease the spatial scale of the cloud by a factor of 500, and localize a ...
Generalized feature detection using the Karhunen-Loeve transform and expansion matching

ABSTRACT This paper presents a novel generalized feature extraction method based on the Expansion Matching (EXM)method and the Karhunen-Loeve (KL) transform. This yields an efficient method to locate a large variety offeatures with reduced number of filtering operations. The EXM method is used to design optimal detectors fordifferent features. The KL representation is used to define an optimal basis for representing these EXM featuredetectors with minimum truncation error. Input images are then analyzed with the the resulting KL bases. The KL coefficients obtained from the analysis are used to efficiently reconstruct the response due to any combination of feature detectors. The method is applied to real images and successfully extracts a variety of arc and edge features as well as complex junction features formed by combining two or more arc or line features. 1 INTRODUCTION Feature extraction forms an important preprocessing step in many computer vision and image understandingtasks. The input to the feature extraction system is an image, and the output is the symbolic representations ofvarious features of the shapes in the image, such as the curvature, length, position, and orientation of boundarysegments. Generally, such pre-processing schemes consist of a serie of steps, including edge detection, edge
A FACILE AND SELECTIVE HIGH YIELD SYNTHESIS OF SYMMETRIC DIALKYL-SUBSTITUTED METHYLENEBISPHOSPHONIC ACIDS

ABSTRACT Symmetric P,P′-dialkyl partial esters of methylenebisphosphonic acid were prepared in high yield and high selectivity from the corresponding acid chloride via a facile two-step, one-pot process. The newly developed synthesis, which does not require chromatographic or acid–base extractive purification, offers substantial advantages over previously used procedures.
Sequential Decentralized Parameter Estimation Under Randomly Observed Fisher Information

We consider the problem of decentralized scalar parameter estimation using wireless sensor networks with Gaussian noise. Specifically, we propose a novel framework based on level-triggered sampling, a non-uniform sampling strategy, and sequential estimation. The proposed estimator can be used as an asymptotically optimal fixed-sample-size decentralized estimator when the observed Fisher information, i.e., Fisher information without expectation, is deterministic, as an alternative to the one-shot estimators commonly found in the literature. It can also be used as an asymptotically optimal sequential decentralized estimator when the observed Fisher information is random. We show that the optimal centralized estimator under Gaussian noise, which is the maximum likelihood estimator, is characterized by two processes, namely the observed Fisher information Ut and the observed correlation Vt. It is noted that Vt is always random even when Ut is not. In the proposed scheme, each sensor computes its local random processes, and sends a single bit to the fusion center (FC) whenever the local random processes passes certain predefined levels. The FC, upon receiving a bit from a sensor, updates its approximation to the corresponding global random process and, accordingly, its estimate. The sequential estimation process terminates when Ut (or the approximation to it) reaches a target value. We provide an asymptotic analysis for the proposed estimator and the one based on conventional uniform-in-time sampling under both deterministic and random Ut, and determine the conditions under which they are asymptotically optimal, consistent, and asymptotically unbiased. Analytical results, together with simulation results, demonstrate the superiority of the proposed estimator based on level-triggered sampling over the traditional decentralized estimator based on uniform sampling.
Fully 3D self-consistent quantum transport simulation of Double-gate and Tri-gate 10 nm FinFETs

We utilize a fully self-consistent 3D quantum mechanical simulator based on the Contact Block Reduction (CBR) method to investigate the effects of fin height and unintentional dopant on the device characteristics of a 10-nm FinFET device. The per-fin height off-current is found to be relatively insensitive to fin height while the corresponding per fin height on-current may significantly depend on fin height due to the stronger confinement with decreasing fin height. Also gate leakage is found to show similar behavior as device on-current with decreasing fin height. Tri-gate (TG) FinFET is found to show better performance compared to Double-gate (DG) FinFET, with the exception of gate leakage current. Simulation results show that an unintentional dopant within the channel can significantly alter device characteristics depending on its position and applied biases. In addition, the effects of unintentional dopant are found to be stronger at high drain bias than at low drain bias.
A new synthesis of spiropyrrolidine–tetralones via an unexpected formal ring-contraction of 4-disubstituted piperidine to 3-disubstituted pyrrolidine

Abstract We have developed an efficient synthesis of novel racemic spiropyrrolidine–tetralones via an unexpected ring-contraction reaction of a 4-disubstituted piperidine to 3-disubstituted pyrrolidine. We suggest that intramolecular quaternization of the piperidine nitrogen of compound 7 occurs to form a bridged bicyclic quaternary ammonium salt intermediate 10. The ring opening of 10 with cyanide resulted in pyrrolidine 9. The synthesis of racemic spiropyrrolidine–tetralone 15 is described as well as the related spiropiperidine–indanone, 1b.
NOISE-ENHANCED PARAMETRIC RESONANCE IN PERTURBED GALAXIES

This paper describes how parametric resonances associated with a galactic potential subjected to relatively low-amplitude, strictly periodic time-dependent perturbations can be impacted by pseudo-random variations in the pulsation frequency, modeled as colored noise. One aim thereby is to allow for the effects of a changing oscillation frequency as the density distribution associated with a galaxy evolves during violent relaxation. Another is to mimic the possible effects of internal substructures, satellite galaxies, and/or a high-density environment. The principal conclusions are that allowing for a variable frequency does not vitiate the effects of parametric resonance, and that, in at least some cases, such variations can increase the overall importance of parametric resonance associated with systematic pulsations.
Zeros of conformal fields in any metric signature

The connected components of the zero set of any conformal vector field, in a pseudo-Riemannian manifold of arbitrary signature, are shown to be totally umbilical conifold varieties, that is, smooth submanifolds except possibly for some quadric singularities. The singularities occur only when the metric is indefinite, including the Lorentzian case. This generalizes an analogous result for Riemannian manifolds, due to Belgun, Moroianu and Ornea (2011J. Geom. Phys. 61 589).
Chelating bis(thiophosphinic amidate)s as versatile supporting ligands for the group 3 metals. An application to the synthesis of highly active catalysts for intramolecular alkene hydroamination.

Bis(thiophosphinic amidate) complexes (i.e., 1) of representative group 3 and lanthanide metals have been quantiatively prepared in situ from the corresponding thiophosphinic amides and Ln[N(TMS)2]3. These unusual pentacoordinate complexes exhibit very high activity as catalysts for intramolecular alkene hydroamination.
A review of gas–solid dispersion and mass transfer coefficient correlations in circulating fluidized beds

Abstract It is increasingly more important to be able to predict the conversion and yield of reactant species given the ever rising cost of the reactants and the ever decreasing acceptable level of effluent contaminants. As such, the development and use of predictive models for the reactors is necessary for most processes today. These models all take into account in some manner the relative movement of the gas and of the solid species as well as the interphase mass transfer. The model developer, unless equipped with specific experimentally based empirical correlations for the reactor system under consideration, is required to go to the open literature to obtain correlations for the axial and radial gas dispersion coefficients, the solids axial and radial dispersion coefficients and the interphase mass transfer coefficient between the solid phase and the gas phase. This is a difficult task at present since these values differ by up to 7 orders of magnitude for the mass transfer coefficient and up to 5 orders of magnitude for dispersion coefficients. This paper presents a summary of the work in these areas as found in the literature dating back to 1949 and provides a critical review to guide the selection of the best correlation(s) in circulating fluidized bed reactors. The driver for this paper is the uncertainties due to hydrodynamics that effect conversion in CFBs and as such only reviews the mass transfer coefficient and the gas and solids dispersion coefficients. A comparison of heat transfer coefficients is therefore not included.
The Lazy Adversary Conjecture Fails

In the context of competitive analysis of online algorithms for the k-server problem, it has been conjectured that every randomized, memoryless online algorithm exhibits the highest competitive ratio against an offline adversary that is lazy, i.e., that will issue requests forcing it to move one of its own servers only when this is strictly necessary to force a move on the part of the online algorithm. We prove that, in general, this lazy adversary conjecture fails. Moreover, it fails in a very strong sense: there are adversaries which perform arbitrarily better than any other adversary which is even slightly “lazier.”
Theoretical Analysis of Parachute Inflation Including Fluid Kinetics

An analysis is presented for predicting parachute inflation. Equations of motion for the complete system are developed from first principles, and are solved with no experimental inputs. Ballistic equations of motion are derived for the canopy, payload, and suspension line masses. However, the enclosed fluid mass is not lumped with the canopy as an apparent mass term. Instead, the fluid conservation equations for a deforming, accelerating control volume are solved to determine the behavior of the captured fluid and its interaction with the canopy. Only first-order effects are included, and the analysis is limited to inviscid, incompressible flow. Results for both porous and nonporous canopies are compared with experimental data.
Universal lattices and unbounded rank expanders

We study the representations of non-commutative universal lattices and use them to compute lower bounds of the τ-constant for the commutative universal lattices G d,k =SL d (ℤ[x 1,...,x k ]), for d≥3 with respect to several generating sets. As an application we show that the Cayley graphs of the finite groups $\text{SL}_{3k}(\mathbb{F}_{p})$ can be made expanders with a suitable choice of generators. This provides the first example of expander families of groups of Lie type, where the rank is not bounded and provides counter examples to two conjectures of A. Lubotzky and B. Weiss.
Dental Biometrics: Alignment and Matching of Dental Radiographs

Dental biometrics utilizes the evidence revealed by dental radiographs for human identification. This evidence includes the tooth contours, the relative positions of neighboring teeth, and the shapes of the dental work (e.g., crowns, fillings and bridges). The proposed system has two main stages: feature extraction, and matching. The feature extraction stage uses anisotropic diffusion to enhance the images and a mixture of Gaussians model to segment the dental work. The matching stage has three sequential steps: shape registration, computation of image similarity, and subject identification. In shape registration, we align the tooth contours and obtain the distance between them. A second method based on overlapped areas is used to match the dental work. The distance between the shapes of the teeth and the distance between the shapes of the dental work are then combined using likelihood estimates to improve the retrieval accuracy. At the second step, the correspondence of teeth between two given images is established. A distance measure based on this correspondence is then used to represent the similarity between the two images. Finally, the distances are used to infer the subject's identity.
A Practical Titanium-Catalyzed Synthesis of Bicyclic Cyclopentenones and Allylic Amines.

A practical titanium-catalyzed synthesis of bicyclic cyclopentenones and allylic amines is described. The process converts enyne substrates to iminocyclopentenes using 10 mol % of the air- and moisture-stable precatalyst Cp2TiCl2 in the presence of n-BuLi and triethylsilyl cyanide. The resulting iminocyclopentenes can be hydrolyzed to cyclopentenones in good yields or reduced to allylic silylamines with Red-Al or DIBALH. Treatment of the crude silylamines with acetyl chloride allows isolation of allylic amides in excellent yields.
A dual description of decoherence in de Sitter space

Decoherence associated with super-Hubble modes in de Sitter space may have a dual description, in which it is attributed to interaction of sub-Hubble modes with an ``environment'' residing just inside the observer's horizon. We present a version of such description, together with some consistency checks, which it is shown to pass.
Construction of genetically marked Vibrio cholerae O1 vaccine strains.

Attenuated Vibrio cholerae O1 vaccine strains lacking the gene encoding the A subunit of cholera toxin have proven efficacious in preventing experimental cholera. As these strains move from closed, contained testing environment to large-scale field trials, a readily assayable phenotypic trait to distinguish a vaccine strain from wild-type V. cholerae O1 is desirable. We have constructed three derivatives of the attenuated V. cholerae strain CVD 103 which carry a mercury resistance or urease marker in the hlyA gene. CVD 103-HgR was constructed using a protracted marker-exchange procedure; this strain was found to have somewhat lowered colonisation efficiency in infant mice in comparison to its parent strain, CVD 103. The insertion of the resistance marker was repeated using a suicide vector system; CVD 103-HgR2 was found to colonise infant mice as efficiently as CVD 103. Strain CVD 103-UR, in which sequences encoding urease were inserted using a suicide vector, also colonised infant mice as well as CVD 103. The genetically marked strains CVD 103-HgR, CVD 103-HgR2 and CVD 103-UR form the basis for a generation of defined oral vaccines that may give single-dose, long-lasting protection to populations at risk from cholera.
The Critical Group of a Line Graph

The critical group of a graph is a finite abelian group whose order is the number of spanning forests of the graph. This paper provides three basic structural results on the critical group of a line graph. The first deals with connected graphs containing no cut-edge. Here the number of independent cycles in the graph, which is known to bound the number of generators for the critical group of the graph, is shown also to bound the number of generators for the critical group of its line graph. The second gives, for each prime p, a constraint on the p-primary structure of the critical group, based on the largest power of p dividing all sums of degrees of two adjacent vertices. The third deals with connected graphs whose line graph is regular. Here known results relating the number of spanning trees of the graph and of its line graph are sharpened to exact sequences which relate their critical groups. The first two results interact extremely well with the third. For example, they imply that in a regular nonbipartite graph, the critical group of the graph and that of its line graph determine each other uniquely in a simple fashion.
Clinical evaluation of a microleakage test

Abstract Microleakage of amalgam restorations traditionally has been carried out in the laboratory. The present study deals with use of calcium hydroxide as an agent to detect microleakage. This method provides a major difference from previous studies in that the detecting agent leaks from whithin to the outer environment. Forty amalgam restorations made with two different types of alloys were evaluated in the oral cavity. It was shown that calcium hydroxide can be used in vivo to monitor microleakage.
QUARK MATTER IN NEUTRON STARS: AN APERÇU

The existence of deconfined quark matter in the superdense interior of neutron stars is a key question that has drawn considerable attention over the past few decades. Quark matter can comprise an arbitrary fraction of the star, from 0 for a pure neutron star to 1 for a pure quark star, depending on the equation of state of matter at high density. From an astrophysical viewpoint, these two extreme cases are generally expected to manifest different observational signatures. An intermediate fraction implies a hybrid star, where the interior consists of mixed or homogeneous phases of quark and nuclear matter, depending on surface and Coulomb energy costs, as well as other finite size and screening effects. In this review, we discuss what we can deduce about quark matter in neutron stars in light of recent exciting developments in neutron star observations. We state the theoretical ideas underlying the equation of state of dense quark matter, including color superconducting quark matter. We also highlight recent advances stemming from re-examination of an old paradigm for the surface structure of quark stars and discuss possible evolutionary scenarios from neutron stars to quark stars, with emphasis on astrophysical observations.
Coronal holes, solar wind streams, and geomagnetic disturbances during 1978 and 1979

It was found that, during 1978 and 1979, coronal holes reflected the influence of differential rotation, and were present within a slowly evolving large-scale pattern in spite of the relatively high level of sunspot activity. The long-lived 28.5-day pattern is not produced by a rigidly rotating quasi-stationary structure on the sun, but appears to be produced by a nonstationary migratory process associated with solar differential rotation. The association between coronal holes and solar wind speed enhancements at earth continues to depend on the latitude of the holes (relative to the heliographic latitude of earth), but even the best associations since 1976 have speeds of only 500-600 km/s rather than the values of 600-700 km/s that usually occurred during the declining phase of sunspot cycle 20.
Superconformal coset equivalence from level rank duality

Abstract We construct a one-to-one map between the primary fields of the N = 2 superconformal Kazama-Suzuki models G ( m , n , k ) and G ( k , n , m ) based on complex Grassmannian cosets, using level-rank duality of Wess-Zumino-Witten models. We then show that conformal weights, superconformal U(I) charges, modular transformation matrices, and fusion rules are preserved under this map, providing strong evidence for the equivalence of these coset models.
Relating Edelman---Greene insertion to the Little map

The Little map and the Edelman---Greene insertion algorithm, a generalization of the Robinson---Schensted correspondence, are both used for enumerating the reduced decompositions of an element of the symmetric group. We show the Little map factors through Edelman---Greene insertion and establish new results about each map as a consequence. In particular, we resolve some conjectures of Lam and Little.
Photorefractivity in WGM resonators

We report on observation of photorefractive effects in whispering gallery mode resonators made of as-grown lithium niobate and lithium tantalate in the near as well as far infrared. The effects manifested themselves as dynamic modification of the spectra as well as quality factors of the resonators coupled to the laser radiation.
Performance of B + tree concurrency control algorithms

A number of algorithms have been proposed to access B+-trees concurrently, but they are not well understood. In this article, we study the performance of various B+-tree concurrency control algorithms using a detailed simulation model of B+-tree operations in a centralized DBMS. Our study covers a wide range of data contention situations and resource conditions. In addition, based on the performance of the set of B+-tree concurrency control algorithms, which includes one new algorithm, we make projections regarding the performance of other algorithms in the literature. Our results indicate that algorithms with updaters that lock-couple using exclusive locks perform poorly as compared to those that permit more optimistic index descents. In particular, the B-link algorithms are seen to provide the most concurrency and the best overall performance. Finally, we demonstrate the need for a highly concurrent long-term lock holding strategy to obtain the full benefits of a highly concurrent algorithm for index operations.
What makes an image memorable

When glancing at a magazine, or browsing the Internet, we are continuously being exposed to photographs. Despite of this overflow of visual information, humans are extremely good at remembering thousands of pictures along with some of their visual details. But not all images are equal in memory. Some stitch to our minds, and other are forgotten. In this paper we focus on the problem of predicting how memorable an image will be. We show that memorability is a stable property of an image that is shared across different viewers. We introduce a database for which we have measured the probability that each picture will be remembered after a single view. We analyze image features and labels that contribute to making an image memorable, and we train a predictor based on global image descriptors. We find that predicting image memorability is a task that can be addressed with current computer vision techniques. Whereas making memorable images is a challenging task in visualization and photography, this work is a first attempt to quantify this useful quality of images.
The mechanism of the depressor action of dog's urine with some observations on the antagonistic action of adrenalin:

SummaryThe intravenous injections of dog's urine into the dog causes an abrupt but transient lowering of blood pressure, varying from 20 to 90 mm. Hg (usually 40 to 70), not accompanied by disturbance of heart action and with little respiratory disturbance. Section of the spinal cord, vagi, cervical sympathetic and splanchnic nerves and destruction of cœliac ganglia and solar plexus individually or collectively does not abolish the depressor action. Physiological and pharmacological experiments based on Dixon's studies of the action of apocodeine show that when the nerve endings are so paralyzed by apocodeine that adrenalin causes little or no reaction, the urine also has no effect. Likewise, in normal animals, and in those with central vaso-motor influence eliminated, the action of urine is antagonistic to that of adrenalin and barium and during the increased pressure due to electrical stimulation of the nerves of the splanchnic area, the urine causes a fall in pressure.
The effects of hypophysectomy on the digestive glands of the mouse.

The objective was to observe the influence of hypophysectomy on the secretory cells of digestive glands in the mouse and to compare these findings with those reported for other mammalian species. Hypophysectomy of the mouse induced involutional changes in glandular cells concerned with secretion of proteins and mucins, and in those involved in ion transport or release. Gastric chief cells, pancreatic acinar cells, and serous cells of submandibular tubules were markedly involuted; acinar cells of the parotid gland were changed less significantly. Gastric mucous neck cells and mucous acinar cells of the submandibular and sublingual glands contained less secretory material. A colloidal iron-positive variety of mucous neck cell became dominant. These changes were less profound than those which occurred in most types of zymogenic cells. Parietal cells became atrophic and contained a greatly contracted intracellular canalicular system. Salivary ducts of the parotid and sublingual glands showed partial involution. It was concluded that, as in the rat and man, protein-secreting cells of the digestive tract of the mouse depend on the support of pituitary hormones. Those cells which secrete mucopolysaccharides or are involved in ion transport also require pituitary hormones for complete maintenance of their structure and function.
One-step formation of fused tetracyclic skeletons from cyclohexene-diynes and carbon monoxide through Rh(I)-catalyzed [2 + 2 + 2 + 1] cycloaddition reaction

Rapid construction of 5-7-6-5 fused tetracyclic carbocycles and heterocycles from cyclohexene-diynes and CO has been achieved in one step through a Rh(I)-catalyzed [2 + 2 + 2 + 1] cycloaddition process.
Molecular Beam Studies of Bimolecular Reactions: F + H2 and Li + HF

Using reactions of F + H2 HF + H and Li + HF LiF + H as examples, the application of the crossed molecular beams method in the investigation of dynamics of bimolecular chemical reactions is described. Most of the discussions are centered on the angular distributions of reaction products and their implication to the relation between potential energy surface and reaction dynamics.
Stereoselective Synthesis of γ-hydroxy-α-amino acids via intramolecular amidomercuration

Abstract A general method for the stereoselective conversion of homoallylic alcohols to erythro- or threo-β-hydroxy-α-amino acids is described. The key step is the stereoselective mercuric ion-initiated cyclofunctionalization of acylaminomethyl ether derivatives of the homoallylic alcohols (3 → 8). The stereochemistry of the products obtained from the cyclofunctionalization is controlled by the choice of reaction conditions. Reaction under conditions of kinetic control leads to predominant formation of cis 4,6-disubstituted tetrahydro-1,3-oxazines, while reaction under conditions which allow for equilibration of the organomercurial intermediates results in the formation of the trans stereoisomer with very high stereoselectivity. Oxidative demercuration and oxidation of the resulting alcohol produces a protected form of the title amino acids (8 → 9 → 10). Cleavage of the tetrahydrooxazine ring with hydrobromic acid then produces the amino acid products asγ-butyrolactone hydrobromides (11 and 12). This general method thus allows for stereoselective synthesis of either diastereomer of the amino acid product starting with a single homoallylic alcohol.
On Resource Allocation in Fading Multiple-Access Channels–An Efficient Approximate Projection Approach

In this paper, we consider the problem of rate and power allocation in a multiple-access channel (MAC). Our objective is to obtain rate and power allocation policies that maximize a general concave utility function of average transmission rates on the information-theoretic capacity region of the MAC without using queue-length information. First, we address the utility maximization problem in a nonfading channel and present a gradient projection algorithm with approximate projections. By exploiting the polymatroid structure of the capacity region, we show that the approximate projection can be implemented in time polynomial in the number of users. Second, we present optimal rate and power allocation policies in a fading channel where channel statistics are known. For the case that channel statistics are unknown and the transmission power is fixed, we propose a greedy rate allocation policy and characterize the performance difference of this policy and the optimal policy in terms of channel variations and structure of the utility function. The numerical results demonstrate superior convergence rate performance for the greedy policy compared to queue-length-based policies. In order to reduce the computational complexity of the greedy policy, we present approximate rate allocation policies which track the greedy policy within a certain neighborhood.
Analog optical processing of moire deflectometry using Fourier techniques

We demonstrate a new all-optical method of moire fringe analysis for the purpose of fast wavefront detection and correction of single ultrashort light pulses. The magnitude and sense of wavefront curvature is determined by fringe orientation. Single-shot fringe processing takes place at the Fourier plane of an imaging lens with an apodized slit as the transmission filter. The curvature (directional 2 nd derivative) of the wavefront shape is obtained as an image. Results imply the possibility of fast detection and correction of single pulses.
Synthesis of [1]benzothienonaphthyridines

3-Chlorobenzo[b]thiophene-2-carbonyl chloride reacted readily with 2-amino-, 3-amino-, or 4-aminopyridine to give the corresponding amides. Photocyclization of the amides afforded the following lactams: [1]ben-zothieno[2,3-c][1,5]naphthyridin-6(5H)-one (14), [1]benzothieno[2,3-c][1,6]naphthyridin-6(5H)-one (7), [1]benzo-thieno[2,3-c][1,7]naphthyridin-6(5H)-one (11), and [1]benzothieno[2,3-c][1,8]naphthyridin-6(5H)-one (3). These lactams have been converted to other derivatives including in two instances the unsubstituted ring system.
Aluminum- and boron-mediated c-glycoside synthesis from 1,2-anhydroglycosides.

This letter describes a single flask strategy to the synthesis of α-C-glycosides from glycals. This protocol couples a glycal epoxidation reaction with a C-2 alkoxy-directed carbon−carbon bond-forming reaction.
Kinetic stability of large-scale MHD modes☆

Abstract Two independent particle methods, which are based on the Vlasov fluid model, have been developed to examine the modification of magnetohydrodynamic instabillities due to finite orbit effects. The relative cost and accuracy of the methods, the dispersion functional analysis and initial value method, are discussed and the results of applying the methods to a field-reversed, magnetic confinement geometry are presented.
Transition from hexagonal to cubic structure and enhanced specific heat in CePt5−xAux

In our attempt to replace platinum successively by gold in CePt5−xAux, we have found that with increased Au content the initial hexagonal CaCu5 structure of CePt5 changes into the cubic AuBe5 structure for 1 < x ⩽ 3. Since this is the same lattice as in the heavy fermion system UPt4Au, with U replaced by Ce, we can now compare the role of the two different elements in this configuration. We have investigated the influence of the Au content on the low temperature specific heat and magnetic susceptibility, which both increase with increasing Au content, and discuss to what extent this enhancement might be created by the electronic density of states or by magnetic entropy. Furthermore, we have studied the transition from the U-based heavy fermion system into the Ce-based system in U1−yCeyPt4Au.
Brane localized curvature for warped gravitons

We study the effects of including brane localized curvature terms in the Randall-Sundrum (RS) model of the hierarchy. This leads to the existence of brane localized kinetic terms for the graviton. Such terms can be induced by brane and bulk quantum effects as well as Higgs-curvature mixing on the brane. We derive the modified spectrum of Kaluza-Klein (KK) gravitons and their couplings to 4-dimensional fields in the presence of these terms. We find that the masses and couplings of the KK gravitons have considerable dependence on the size of the brane localized terms; the weak-scale phenomenology of the model is consequently modified. In particular, the weak-scale spin-2 graviton resonances which generically appear in the RS model may be significantly lighter than previously assumed. However, they may avoid detection as their widths may be too narrow to be observable at colliders. In the contact interaction limit, for a certain range of parameters, the experimental reach for the scale of the theory is independent of the size of the boundary terms.
On correlation functions of Wilson loops, local and non-local operators

We discuss and extend recent conjectures relating partial null limits of correlation functions of local gauge invariant operators and the expectation value of null polygonal Wilson loops and local gauge invariant operators. We point out that a particular partial null limit provides a strategy for the calculation of the anomalous dimension of short twist- two operators at weak and strong coupling.
Thermal noise and stochastic strings in AdS/CFT

We clarify the structure of thermal noise in AdS/CFT by studying the dynamics of an equilibrated heavy quark string. Using the Kruskal extension of the correspondence to generate the dynamics of the field theory on the Keldysh contour, we show that the motion of the string is described by the classical equations of motion with a stochastic boundary condition on the stretched horizon. The form of the stochastic boundary condition is consistent with the dissipation on this surface and is found by integrating out the fluctuations inside of the stretched horizon. Solving the equations of motion for the fluctuating string we determine the full frequency dependence of the random force on the boundary quark and show that it is consistent with the frequency dependent dissipation. We show further that the stochastic motion reproduces the bulk to bulk two point functions of the Kruskal formalism. These turn out to be related to the usual retarded bulk to bulk propagator by KMS relations. Finally we analyze the stochastic equations and give a bulk picture of the random boundary force as a flip-flopping trailing string solution. The basic formalism can be applied to the fluctuations of gravitons, dilatons, and other fields.
Single molecule spectral diffusion in a solid detected via fluorescence spectroscopy

Abstract Recent advances in fluorescence excitation spectroscopy have produced significant increases in detection sensitivity for single pentacene molecules in crystals of p-terphenyl at low temperatures. With the increased signal to noise ratio, we have observed two classes of pentacene behavior. While some pentacene defects have fixed, lifetime limited Lorentzian excitation line shapes (7.8 MHz FWHM), other pentacene defects exhibit spontaneous shifts in resonance frequency of up to 100 MHz. Residence times between spectral jumps are on the order of seconds to minutes at 1.5 K. Increasing the temperature from 1.5 to 6 K appears to produce a faster-than-linear increase in jump rate with temperature; we suggest single pentacene defect spectral diffusion is due to thermally assisted structural changes in the p-terphenyl environment.
A hybrid FARA/CSMA-CD protocol for voice-data integration

Abstract A new hybrid packet switching protocol for voice-data integration is proposed and analysed. The protocol adapts to the changing traffic conditions of both voice and data. Network control is distributed over all nodes, thus eliminating the need for central switching or multiplexing. Voice users follow a modified version of FARA, whereas CSMA-CD is adopted by data users for their channel access policy. The analysis is based on the solution of a 2-state Markovian chain, after which the voice blocking probability, data packets delay and network throughputs are determined.
Molecular Rearrangements in the Ligand-Binding Domain of Cyclic Nucleotide–Gated Channels

Abstract Cyclic nucleotide–gated (CNG) channels are activated in response to the direct binding of cyclic nucleotides to an intracellular domain. This domain is thought to contain a β roll and two α helices, designated the B and C helices. To probe the conformational changes occurring in the ligand-binding domain during channel activation, we used the substituted cysteine accessibility method (SCAM). We found that a residue in the β roll, C505, is more accessible in unliganded channels than in liganded channels, whereas a residue in the C helix, G597C, is more accessible in closed channels than in open channels. These results support a molecular mechanism for channel activation in which the ligand initially binds to the β roll, followed by an opening allosteric transition involving the relative movement of the C helix toward the β roll.
The Reallocation of Compensation in Response to Health Insurance Premium Increases

Abstract We examine how employees reallocate compensation in response to increase in health insurance premiums. We find that a $1 increase in insurance premiums leads to a 52-cent increase in health insurance expenditures. Approximately 2/3 of this increase is financed through reduced wages and 1/3 through other benefits.
Decarboxylative Aldol Reactions of Allyl β-Keto Esters via Heterobimetallic Catalysis

Mild and selective heterobimetallic-catalyzed decarboxylative aldol reactions involving allyl β-keto esters have been developed. The reaction is promoted by Pd(0)− and Yb(III)−DIOP complexes at room temperature and involves the in situ formation of a ketone enolate from allyl β-keto esters followed by addition of the enolate to aldehydes. The reaction is a new example of heterobimetallic catalysis in which the optimized reaction conditions require the addition of both metals.
The Effect of Time-on-Market and Location on Search Costs and Anchoring: The Case of Single-Family Properties

Regarding single-family residential properties purchased for investment (non-owner occupied) we examine whether out-of-state buyers pay more than in-state buyers. We focus on the effects of search costs and anchoring. We use data on 2,828 Las Vegas non-owner occupied (investor) residences, 40% of which are purchased by non-local investors. We find that the location of the property affects the empirical results. Specifically, search cost and anchoring effects that appear significant when the location of the property is ignored disappear when location is introduced as an independent variable.
Dynamical fermions as a global correction

Abstract In the simplified setting of the Schwinger model we present a systematic study on the simulation of dynamical fermions by global accept/reject steps that take into account the fermion determinant. A family of exact algorithms is developed, which combine stochastic estimates of the determinant ratio with the exploitation of some exact extremal eigenvalues of the generalized problem defined by the ‘old’ and the ‘new’ Dirac operator. In this way an acceptable acceptance rate is achieved with large proposed steps and over a wide range of couplings and masses.
The Hausman-Taylor panel data model with serial correlation

Abstract This paper modifies the Hausman and Taylor (1981) panel data estimator to allow for serial correlation in the remainder disturbances. It demonstrates the gains in efficiency of this estimator versus the standard panel data estimators that ignore serial correlation using Monte Carlo experiments.
Double activation preparation of an acridinyl-isoxazolyl-lexitropsin

Abstract The coupling of a sterically hindered acridinyl isoxazole ester directly to the amine group of a lexitropsin is significantly improved by double activation, using trimethylaluminum to activate the amine portion and samarium (III) chloride to enhance the carboxylate reactivity.
The analysis of high pressure experimental data

This letter is concerned with the analysis of high pressure experimental data. It is demonstrated that ln H plots based on the Vinet et al. (1988) universal equation of state are a simple sensitive means for identifying anomalous P-V data in high pressure experiments and for detecting structural and phase transitions in solids subjected to high pressure.
Measurement and analysis of an online content voting network: a case study of Digg

In online content voting networks, aggregate user activities (e.g., submitting and rating content) make high-quality content thrive through the unprecedented scale, high dynamics and divergent quality of user generated content (UGC). To better understand the nature and impact of online content voting networks, we have analyzed Digg, a popular online social news aggregator and rating website. Based on a large amount of data collected, we provide an in-depth study of Digg. We study structural properties of Digg social network, revealing some strikingly distinct properties such as low link symmetry and the power-law distribution of node outdegree with truncated tails. We explore impact of the social network on user digging activities, and investigate the issues of content promotion, content filtering, vote spam and content censorship, which are inherent to content rating networks. We also provide insight into design of content promotion algorithms and recommendation-assisted content discovery. Overall, we believe that the results presented in this paper are crucial in understanding online content rating networks.