cssi/SciSciGPT-SciSciNet huggingface dataset:
A SPITZER IRS SURVEY OF NGC 1333: INSIGHTS INTO DISK EVOLUTION FROM A VERY YOUNG CLUSTER

We report on the {lambda} = 5-36 {mu}m Spitzer Infrared Spectrograph (IRS) spectra of 79 young stellar objects in the very young nearby cluster NGC 1333. NGC 1333's youth enables the study of early protoplanetary disk properties, such as the degree of settling and the formation of gaps and clearings. We construct spectral energy distributions (SEDs) using our IRS data as well as published photometry and classify our sample into SED classes. Using 'extinction-free' spectral indices, we determine whether the disk, envelope, or photosphere dominates the spectrum. We analyze the dereddened spectra of objects that show disk-dominated emission using spectral indices and properties of silicate features in order to study the vertical and radial structure of protoplanetary disks in NGC 1333. At least nine objects in our sample of NGC 1333 show signs of large (several AU) radial gaps or clearings in their inner disk. Disks with radial gaps in NGC 1333 show more nearly pristine silicate dust than their radially continuous counterparts. We compare properties of disks in NGC 1333 to those in three other well-studied regions, Taurus-Auriga, Ophiuchus, and Chamaeleon I, and find no difference in their degree of sedimentation and dust processing.
CaCu3Ti4O12: Low-Temperature Synthesis by Pyrolysis of an Organic Solution

The giant-dielectric-constant material CaCu3Ti4O12 (CCTO) has been synthesized by pyrolyzing an organic solution containing stoichiometric amounts of the metal cations, which is done at lower temperature and shorter reaction time than the conventional solid-state reaction. A stable solution was prepared by dissolving calcium nitrate, copper(II) nitrate, and titanium(IV) isopropoxide in 2-methoxyethanol. This solution was pyrolyzed and heat-treated to achieve single-phase CCTO. The phases, microstructures, and dielectric properties of intermediate and final samples were characterized by X-ray diffraction, scanning electron microscopy, and dielectric spectroscopy.
Learning ontologies to improve the quality of automatic web service matching

This paper presents a novel technique that significantly improves the quality of semantic Web service matching by (1) automatically generating ontologies based on Web service descriptions and (2) using these ontologies to guide the mapping between Web services.
The preparation of isotopically labelled macrocyclic compounds by organic synthesis

The preparation of isotopically labelled macrocyclic compounds is reviewed with pertinent literature references through the end of 2000.
Inter-cell antenna calibration for coherent joint transmission in TDD system

In this work the modeling and calibration method of reciprocity error in a coherent TDD coordinated multi-point (CoMP) joint transmission (JT) system are addressed. The modeling includes parameters such as amplitude gains and phase differences of RF chains between the eNBs. The calibration method used for inter-cell antenna calibration is based on precoding matrix indicator (PMI) feedback by UE. Furthermore, we provide some simulation results for evaluating the performance of the calibration method in different cases such as varying estimation-period, cell-specific reference signals (CRS) ports configuration, signal to noise ratio (SNR), phase difference, etc. The main conclusion is that the proposed method for inter-cell antenna calibration has good performance for estimating the residual phase difference.
The scaling limits of planar LERW in finitely connected domains.

We define a family of stochastic Loewner evolution-type processes in finitely connected domains, which are called continuous LERW (loop-erased random walk). A continuous LERW describes a random curve in a finitely connected domain that starts from a prime end and ends at a certain target set, which could be an interior point, or a prime end, or a side arc. It is defined using the usual chordal Loewner equation with the driving function being $\sqrt{2}B(t)$ plus a drift term. The distributions of continuous LERW are conformally invariant. A continuous LERW preserves a family of local martingales, which are composed of generalized Poisson kernels, normalized by their behaviors near the target set. These local martingales resemble the discrete martingales preserved by the corresponding LERW on the discrete approximation of the domain. For all kinds of targets, if the domain satisfies certain boundary conditions, we use these martingales to prove that when the mesh of the discrete approximation is small enough, the continuous LERW and the corresponding discrete LERW can be coupled together, such that after suitable reparametrization, with probability close to 1, the two curves are uniformly close to each other.
Distributed fine grain adaptive-FEC scheme for scalable video streaming

In this paper, we investigate a distributed fine grain adaptive FEC (FGA-FEC) scheme for scalable video streaming to heterogeneous users over a congested multihop network, where we do FGA-FEC decode/recode at selected intermediate overlay nodes, and do FGA-FEC adaptation at remaining nodes. In order to reduce the overall computational burden, we propose two methods: (1) a coordination between optimization processes running at adjacent nodes to reduce the optimization computation, and (2) extension of our overlay multihop FEC (OM-FEC 1, 2 ) to reduce the number of FGA-FEC decode/recode nodes. Simulations show that the proposed scheme can greatly reduce computation, and can provide near best possible video quality to diverse users.
Theoretical analysis of time delays and streaking effects in XUV photoionization

We apply a recently proposed theoretical concept and numerical approach to obtain time delays in extreme ultraviolet (XUV) photoionization of an electron in a short- or long-range potential. The results of our numerical simulations on a space–time grid are compared to those for the well-known Wigner–Smith time delay and different methods to obtain the latter time delay are reviewed. We further use our numerical method to analyze the effect of a near-infrared streaking field on the time delay obtained in the numerical simulations.
ON MULTILINEAR SPECTRAL CLUSTER ESTIMATES FOR MANIFOLDS WITH BOUNDARY

We prove bilinear and trilinear estimates for the spectral cluster operator on two and three-dimensional compact manifolds with boundary. These are the natural analogs of earlier estimates for the boundaryless case of Burq, G\'erard, and Tzvetkov~\cite{bgtbilin}, \cite{bgtmultilin}. Our theorem reduces to establishing inequalities over small cubes whose size depends on frequency. After rescaling, these inequalities follow from mixed $L^p$ norm estimates on squarefunctions associated to the wave equation.
Accounting for price dependencies in simultaneous sealed-bid auctions

Current autonomous bidding strategies for complex auctions typically employ a two phased architecture: first, the agent predicts a distribution over good prices, and then the agent generates bids given those predictions, usually using a heuristic. For computational reasons, previous state-of-the-art methods assumed prices were independent across goods, and then bid based on marginal price distributions. However, prices for goods are typically dependent, especially for complements and substitutes. We examine and bound the potential error from bidding with respect to marginal price distributions when good prices are in fact correlated. Then, to mitigate this error, we develop computationally feasible methods for predicting joint price distributions, and employing such predictions in bidding strategies. We also demonstrate experimentally that the state-of-the-art heuristic for bidding in simultaneous second-price sealed-bid auctions is outdone by the analog of this same heuristic bidding with respect to joint instead of marginal price predictions.
The diversity-multiplexing tradeoff of the symmetric MIMO half-duplex relay channel

The diversity-multiplexing tradeoff (DMT) is obtained for the symmetric MIMO half-duplex (HD) relay channel where the source and the destination have n antennas each and the relay node has m antennas (hereafter, such a channel is referred to as an (n, m)-relay channel). The characterization of the DMT requires the joint eigenvalue distribution of three specially correlated central Wishart random matrices, which is derived using a related result in [1], [2]. The explicit characterization of the DMT, besides providing the theoretical benchmark for evaluating performance of practical cooperative protocols on this channel, reveals several interesting facts such as: a) the HD operation of the relay fundamentally limits relay channel performance in the sense that the DMT of the full-duplex (FD) relay channel can be strictly greater than that of the HD relay channel; b) an extra antenna at the relay node on a HD relay channel does not always improve the achievable diversity order, unlike that on an FD relay channel. While the fundamental DMTs of the two channels (FD and HD) coincide for a range of low multiplexing gains (MG), this range becomes smaller and the gap between the two (HD and FD) at higher MGs become larger with increasing number of antennas at the relay node, thus potentially justifying the extra cost of an FD relay. It is also proved that the DMTs of the HD and FD (n, 1)-relay channels are the same. Finally, it is shown that the DMT of the (1, m) relay channel can be achieved over different ranges of multiplexing gains by the dynamic decode-and-forward (DDF) and the quantize-andforward (QF) protocols.
The objective of a privately owned firm under imperfect competition

This paper proposes a model of imperfect competition among privately owned firms that act in the best interest of their shareholders. The existence of a solution for the model is proved under weaker conditions than the ones generally used in the literature. In particular, the results did not require the existence of a continuous equilibrium price selection or concavity assumptions on the profit function.
A view of genetics.

Joshua Lederberg's published version of his public lecture/acceptance speech given in Stockholm May 29, 1959 after being awarded of the Nobel Prize in 1958.
Optical spectra and exchange-correlation effects in molecular crystals

We report the first-principles $GW$-Bethe--Salpeter equation and quantum Monte Carlo calculations of the optical and electronic properties of molecular and crystalline rubrene $({\mathrm{C}}_{42}{\mathrm{H}}_{28})$. Many-body effects dominate the optical spectrum and quasiparticle gap of molecular crystals. We interpret the observed yellow-green photoluminescence in rubrene microcrystals as a result of the formation of intermolecular, charge-transfer, spin-singlet excitons. In contrast, spin-triplet excitons are localized and intramolecular with a predicted phosphorescence at the red end of the optical spectrum. We find that the exchange energy plays a fundamental role in raising the energy of intramolecular spin-singlet excitons above the intermolecular ones. Exciton binding energies are predicted to be around $0.5\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ (spin singlet) to $1\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ (spin triplet). The calculated electronic gap is $2.8\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$. The theoretical absorption spectrum agrees very well with recent ellipsometry data.
Pseudoholomorphic strips in symplectisations I: Asymptotic behavior

Abstract This paper is part of a larger program, the investigation of the Chord Problem in three dimensional contact geometry. The main tool will be pseudoholomorphic strips in the symplectisation of a three dimensional contact manifold with two totally real submanifolds L 0 , L 1 as boundary conditions. The submanifolds L 0 and L 1 do not intersect transversally. The subject of this paper is to study the asymptotic behavior of such pseudoholomorphic strips.
A Cross-Country Empirical Analysis of International Reserves

Using data from more than 100 economies for the period of 1975 to 2005, we conduct an extensive empirical analysis of the determinants of international reserve holdings. Four groups of determinants, namely, traditional macro variables, financial variables, institutional variables, and dummy variables that control for individual economies’ characteristics are considered. We find that the relationship between international reserves and their determinants is significantly different between developed and developing economies and is not stable over time. The estimation results indicate that, especially during the recent period, a developed economy tends to hold a lower level of international reserves than a developing one. Furthermore, there is only limited evidence that East Asian economies including China and Japan are accumulating an excessive amount of international reserves.
Synthesis of oligonucleotides via phosphoramidite approach utilizing 2-diphenylmethylsilylethyl (DPSE) as a phosphorus protecting group

Abstract 2-Diphenylmethylsilylethyl (DPSE) is a new protecting group for internucleotidic bonds in the synthesis of oligodeoxyribo nucleotides by the phosphoramidite approach. This group is stable to acidic conditions and can be removed under mild β-fragmentation conditions using aqueous ammonium hydroxide.
NORMALIZERS OF PARABOLIC SUBGROUPS OF COXETER GROUPS

We improve a bound of Borcherds on the virtual co- homological dimension of the non-reflection part of the normalizer of a parabolic subgroup of a Coxeter group. Our bound is in terms of the types of the components of the corresponding Coxeter sub- diagram rather than the number of nodes. A consequence is an extension of Brink's result that the non-reflection part of a re- flection centralizer is free. Namely, the non-reflection part of the normalizer of parabolic subgroup of type D5 or Am odd is either free or has a free subgroup of index 2. Supposeis a Coxeter diagram, J is a subdiagram and WJ ⊆ Wis the corresponding inclusion of Coxeter groups. The normalizer NW� (WJ) has been described in detail by Borcherds (3) and Brink- Howlett (5). Such normalizers have significant applications to working out the automorphism groups of Lorentzian lattices and K3 surfaces; see (3) and its references. NW� (WJ) falls into 3 pieces: WJ itself, another Coxeter group W, and a group of diagram automorphisms of W. The last two groups are called the "reflection" and "non-reflection" parts of the normalizer. Borcherds bounded the virtual cohomological dimension of by |J|. Our theorems 1, 3 and 4 give stronger bounds, in terms of the types of the components of J rather than the number of nodes. There are choices involved in the definition of W and , and our bound in theorem 3 applies regardless of how these choices are made (theorem 1 is a special case). Theorem 4 improves this bound when W is "maximal". In this case, when J = D5 or Amodd, turns out to either be free or have an index 2 subgroup that is free. This extends Brink's result (4) that is free when J = A1. The author is grateful to the Clay Mathematics Institute, the Japan Society for the Promotion of Science, and Kyoto University for their support and hospitality.
Analysis of the refractive indices of TiO2, TiOF2, and TiF4: concept of optical channel as a guide to understand and design optical materials.

In an effort to gain insight into how optical properties of insulating materials are affected by a change in chemical composition, we investigated the dielectric functions of titanium dioxide, TiO2...
High-Redshift Supernovae in the Hubble Deep Field

Two supernovae detected in the Hubble Deep Field (HDF) using the original 1995 December epoch and data from a shorter (63,000 s in F814W) 1997 December visit with {ital HST} are discussed. The supernovae (SNe) are both associated with distinct galaxies at redshifts of 0.95 (spectroscopic) from Cohen et al. and 1.32 (photometric) from the work of Fern{acute a}ndez-Soto, Lanzetta, & Yahil. These redshifts are near, in the case of 0.95, and well beyond, for 1.32, the greatest distance reported previously for SNe. We show that our observations are sensitive to supernovae to z{approx_lt}1.8 in either epoch for an event near peak brightness. Detailed simulations are discussed that quantify the level at which false events from our search phase would start to arise and the completeness of our search as a function of both SN brightness and host galaxy redshift. The number of Type Ia and Type II SNe expected as a function of redshift in the two HDF epochs are discussed in relation to several published predictions and our own detailed calculations. A mean detection frequency of one SN per epoch for the small HDF area is consistent with expectations from current theory. {copyright} {ital {copyright} 1999.} {ital Themore » American Astronomical Society}« less
Transistor Reset Preamplifier for High Rate High Resolution Spectroscopy

Pulsed transistor reset of high resolution charge sensitive preamplifiers used in cooled semiconductor spectrometers can sometimes have an advantage over pulsed light reset systems. Several versions of transistor reset spectrometers using both silicon and germanium detectors have been built. This paper discusses the advantages of the transistor reset system and illustrates several configurations of the packages used for the FET and reset transistor. It also describes the preamplifer circuit and shows the performance of the spectrometer at high rates.
Principal value resummation

Abstract We present a new resummation formula for the Drell-Yan cross section. The formal resummation of threshold corrections in Drell-Yan hard-scattering functions produces an exponent with singularities from the infrared pole of the QCD running coupling. Our reformulation treats such “infrared renormalons” by a principal value prescription, analogous to a modified Borel transform. The resulting expression includes all large threshold corrections to the hard-scattering function as an asymptotic series in αs, but is a finite function of Q2. We find that the ambiguities of the resummed perturbation theory imply the presence of higher twist corrections to quark-antiquark hard-scattering functions that begin at ʌ QCD /Q . This suggests an important role for higher twist in the phenomenology of hadron-hadron inclusive cross sections. We also discuss the numerical evaluation of the exponent and its asymptotic perturbation series for representative values of Q2.
The Cosmic Microwave Background spectrum from the full COBE FIRAS data set

We have refined the analysis of the data from the FIRAS (Far-InfraRed Absolute Spectrophotometer) on board the COBE (COsmic Background Explorer). The FIRAS measures the difference between the cosmic microwave background and a precise blackbody spectrum. We find new, tighter upper limits on general deviations from a blackbody spectrum. The rms deviations are less than 50 parts per million of the peak of the cosmic microwave background radiation. For the Comptonization and chemical potential, we find |y| < 15 × 10–6 and |μ| < 9 × 10–5 (95% confidence level [CL]). There are also refinements in the absolute temperature, 2.728 ± 0.004 K (95% CL), the dipole direction, (1, b)/(26414 ± 0.30, 4826 ± 0.30) (95% CL), and the amplitude, 3.372 ± 0.014 mK (95% CL). All of these results agree with our previous publications.
Instability mechanism at driven contact lines

An explanation of the mechanism for the fingering instability at driven contact lines is presented. Semiquantitative predictions for the growth of the fingers as a function of time, the most unstable wavelength, and the initial growth rate are deduced. These predictions are consistent with recent experiments of de Bruyn [Phys. Rev. A 46, R4500 (1992)].
Understanding galaxy outflows as the product of unstable turbulent support

The interstellar medium is a multiphase gas in which turbulent support is as important as thermal pressure. Sustaining this configuration requires both continuous turbulent stirring and continuous radiative cooling to match the decay of turbulent energy. While this equilibrium can persist for small turbulent velocities, if the one-dimensional velocity dispersion is larger than ≈ 35 km/s, the gas moves into an unstable regime that leads to rapid heating. I study the implications of this turbulent runaway, showing that it causes a hot gas outflow to form in all galaxies with a gas surface density above ≈ 50 M⊙ pc −2 , corresponding to a star formation rate per unit area of ≈ 0.1 M⊙ yr −1 kpc −2 . For galaxies with vesc ∼ 200 km/s, the sonic point of this hot outflow should lie interior to the region containing cold gas and stars, while for galaxies with smaller escape velocities, the sonic point should lie outside this region. This leads to efficient cold cloud acceleration in higher massgalaxies, while in lower mass galaxies, clouds may be ejected by random turbulent motions rather than accelerated by the wind. Finally, I show that energy balance cannot be achieved at all for turbulent media above a surface density of ≈ 10 5 M⊙ pc −2 . Subject headings: galaxies: starburst — ISM: jets and outflows — ISM: structure
Sepsis-Induced Tissue Hypoperfusion

The understanding of sepsis is continuously evolving. An overview of sepsis-induced tissue hypoperfusion has been provided herein. It is of critical importance that the clinician understands the pathophysiology of this emergent condition and is able to synthesize the available data in a rapid fashion so that tissue hypoperfusion is readily detected. Once detected, aggressive and endpoint-directed resuscitation should be implemented to reverse the hypoperfusion and to prevent further deterioration, organ dysfunction, and death.
Bullous pemphigoid autoantibodies reactive with intracellular basal keratinocyte antigens: Studies of subclass distribution and complement activation

Using immunofluorescence (IF) and monoclonal antibodies (MoAbs) to IgG subclasses, terminal complement components, and S-protein/vitronectin, we have extended recent observations concerning reactivity of bullous pemphigoid autoantibodies with intracellular antigens located on the polar tips of basal human keratinocytes (HuK). Using three purified bullous pemphigoid IgG fractions, autoantibody reactivity with these intracellular antigens was present in all four IgG subclasses. When skin sections were used as substrate, an identical IgG subclass distribution of autoantibodies for each bullous pemphigoid IgG fraction was observed, but reactive with the basement membrane zone. All three bullous pemphigoid IgG preparations contained IgG subclass autoantibodies capable of complement fixation. Each IgG fraction resulted in fixation of all of the terminal complement components (C5, C6, C7, C8, and C9) and assembly of the membrane attack complex (MAC) on the polar tips of basal HuK. S-protein/vitronectin was not bound in a similar fashion. Normal IgG fractions yielded consistently negative reactions. Thus, bullous pemphigoid autoantibodies, fixed to polar tips of basal HuK, are found in all four IgG subclasses and will activate complement resulting in generation of MAC.
Parity Nonconservation in Hydrogen Involving Magnetic/Electric Resonance

Abstract Parity nonconservation effects in the n =2 state of hydrogen involving a simultaneous magnetic and electric microwave resonance transition are discussed as a possible test of the Weinberg-Salam theory.
Polyoxoanion-supported organometallic complexes

Synthetic, spectroscopic and x-ray crystallographic research directed at assessing the steric and electronic factors which influence the chemical reactivity of polyoxoanions toward electrophiles is reviewed. Emphasis is placed on studies of hexametalate-and trimetaphosphate-supported organometallic complexes of octahedra d6 and square-planar d8 transition metals as well as actinide metals. The effects of metal-and-terminal-ligand substitution within the hexametalate cage are demonstrated through protonation and complexation studies.
Thermal migration of water on the Galilean satellites

We have modeled the thermal migration of water on the Galilean satellites under the assumption of ballistic molecular trajectories. It is found that water migrating owing to solar radiation on an ice-covered satellite will build up in temperate latitudes, in general not reaching the poles. As much as 50 m of ice may have been lost by this process from the equatorial regions of Europa over the age of the solar system. The disappearance of patches of ice - for instance, the bright rays surrounding some impact craters - from the equatorial regions of Ganymede and Callisto may approach a value (the irreversible evaporation rate) three orders of magnitude larger than the net equatorial loss rate for ice-covered Europa. The presence of water ice pole caps on Ganymede extending to the latitudes at which thermal migration becomes important suggests that some process distributed an extensive, thin covering of water on the satellite, and that the equatorial regions were subsequently cleared by the thermal process.
Dynamic stability of a rotor blade using finite element analysis

The aeroelastic stability of flap bending, lead-lag bending, and torsion of a helicopter rotor blade in hover is examined using a finite element formulation based on the principle of virtual work. Quasi-steady two-dimensional airfoil theory is used to obtain the aerodynamic loads. The rotor blade is discretized into beam elements, each with ten modal degrees of freedom. The resulting nonlinear equations of motion are solved for steady-state blade deflections through an iterative procedure. The flutter solution is calculated assuming blade motion to be a small perturbation about the steady solution. The normal mode method based on the coupled rotating natural modes about the steady deflections is used to reduce the number of equations in the flutter eigenanalysis. Results are presented for hingeless and articulated rotor blade configurations.
Basalts and related rocks from deep-sea drilling sites in the Central and Eastern Indian Ocean

Abstract Petrological and geochemical data are presented for basement rocks recovered from thirteen sites (211, 212, 213, 214, 215, 216, 253, 254, 256, 257, 259, 260 and 261) drilled on Legs 22, 26 and 27 of the Deep Sea Drilling Program. Basalts from Sites 212, 213, 253, 257, 259 and 261 have petrographic and geochemical characteristics of tholeiitic basalts from active spreading ridge axes in the major ocean basins. Except for the lower basalts at Site 253, all the basement rocks from four Ninetyeast Ridge sites (214, 216, 253, 254) are similar to oceanic island tholeiitic sequences such as on Amsterdam—St. Paul Islands. The geochemical data for the Ninetyeast Ridge rocks are consistent with the development of this ridge as a hot-spot trace. Basalts from deep ocean Sites 216 and 256 have geochemical characteristics more akin to tholeiitic basalts from spreading ridge axes close to major volcanic islands, i.e. they have high large ion lithophile element abundances relative to tholeiitic basalts found at spreading ridge axes away from islands. Alkali olivine basalts were recovered from Site 211 and they contain abundant amphibole. They are related to the volcanism which created the Cocos—Keeling—Christmas shoal areas.
A Stochastic Calculus Model of Continuous Trading: Optimal Portfolios

The problem of choosing a portfolio of securities so as to maximize the expected utility of wealth at a terminal planning horizon is solved via stochastic calculus and convex analysis. This problem is decomposed into two subproblems. With security prices modeled as semimartingales and trading strategies modeled as predictable processes, the set of terminal wealths is identified as a subspace in a space of integrable random variables. The first subproblem is to find the terminal wealth that maximizes expected utility. Convex analysis is used to derive necessary and sufficient conditions for optimality and an existence result. The second subproblem of finding the admissible trading strategy that generates the optimal terminal wealth is a martingale representation problem. The primary advantage of this approach is that explicit formulas can readily be derived for the optimal terminal wealth and the corresponding expected utility, as is shown for the case of an exponential utility function and a risky security modeled as geometric Brownian motion.
Integration and synchronization of input modes during multimodal human-computer interaction

Our ability to develop robust multimodal systems will depend on knowledge of the natural integration patterns that typify people's combined use of different input modes. To provide a foundation for theory and design, the present research analyzed multimodal interaction while people spoke and wrote to a simulated dynamic map system. Task analysis revealed that multimodal interaction occurred most frequently during spatial location commands, and with intermediate frequency during selection commands. In addition, microanalysis of input signals identified sequential, simultaneous, point-and-speak, and compound integration patterns, as well as data on the temporal precedence of modes and on inter-modal lags. In synchronizing input streams, the temporal precedence of writing over speech was a major theme, with pen input conveying location information first in a sentence. Linguistic analysis also revealed that the spoken and written modes consistently supplied complementary semantic information, rather than redundant. One long-term goal of this research is the development of predictive models of natural modality integration to guide the design of emerging multimodal architectures.
Receptors for intercellular messenger molecules in microbes: similarities to vertebrate receptors and possible implications for diseases in man.

Our focus is on the evolutionary origins of receptors for vertebrate hormones, neuroactive peptides, and related messengers. The first part will survey the possible evolutionary origins and phylogenetic distribution of the vertebrate-type messenger peptides providing a possible clue or guide to the same speculation for the receptor. Also, we will explain current data which suggest why receptors might need to be at least as old or as widely distributed as the messengers. In the latter part we will survey examples of materials in microbes that resemble vertebrate-type receptors and also highlight some possible applications to an understanding of human disease problems.
Cluster Chemistry in Electron-Poor Ae-Pt-Cd Systems (Ae=Ca, Sr, Ba): (Sr,Ba)Pt2Cd4, Ca6Pt8Cd16, and Its Known Antitype Er6Pd16Sb8

Three new ternary polar intermetallic compounds, cubic Ca6Pt8Cd16, and tetragonal (Sr, Ba)Pt2Cd4 have been discovered during explorations of the Ae–Pt–Cd systems. Cubic Ca6Pt8Cd16 (Fm-3m, Z = 4, a = 13.513(1) A) contains a 3D array of separate Cd8 tetrahedral stars (TS) that are both face capped along the axes and diagonally bridged by Pt atoms to generate the 3D anionic network Cd8[Pt(1)]6/2[Pt(2)]4/8. The complementary cationic surface of the cell consists of a face-centered cube of Pt(3)@Ca6 octahedra. This structure is an ordered ternary variant of Sc11Ir4 (Sc6Ir8Sc16), a stuffed version of the close relative Na6Au7Cd16, and a network inverse of the recent Er6Sb8Pd16 (compare Ca6Pt8Cd16). The three groups of elements each occur in only one structural version. The new AePt2Cd4, Ae = Sr, Ba, are tetragonal (P42/mnm,Z = 2, a ≈ 8.30 A, c ≈ 4.47 A) and contain chains of edge-sharing Cd4 tetrahedra along c that are bridged by four-bonded Ba/Sr. LMTO-ASA and ICOHP calculation results and comparisons show that the major bonding (Hamilton) populations in Ca6Pt8Cd16 and Er6Sb8Pd16 come from polar Pt–Cd and Pd–Sb interactions, that Pt exhibits larger relativistic contributions than Pd, that characteristic size and orbital differences are most evident for Sb 5s, Pt8, and Pd16,more » and that some terms remain incomparable, Ca–Cd versus Er–Pd.« less
EFFECTS OF CLAD SWELLING ON EMERGENCY CORE COOLING PERFORMANCE.

Rapid expansion of Zircaloy cladding has been shown to occur at the relatively high temperatures predicted in the unlikely event of a loss-of-coolant accident. Of primary concern to reactor safety ...
Hysteresis in the quantum Hall regimes in electron double quantum well structures

We present here experimental results on magnetotransport coefficients in electron double quantum well (DQW) structures. Consistent with previous studies, transport hysteresis is is observed in the electron DQWs. Furthermore, in our gated DQW samples, by varying the top layer Landau level filling $({\ensuremath{\nu}}_{\mathit{\text{top}}})$ while maintaining a relatively constant filling factor in the bottom layer $({\ensuremath{\nu}}_{\mathit{bot}})$, we are able to explain the sign of ${R}_{xx}(\text{up})\text{\ensuremath{-}}{R}_{xx}(\text{down})$, where ${R}_{xx}(\text{up})$ is the magnetoresistance when the gate voltage ${V}_{g}$ is swept up and ${R}_{xx}(\text{down})$ when ${V}_{g}$ is swept down. Interestingly, at small magnetic fields hysteresis is generally stronger when the top quantum well is in the even integer quantum Hall effect (IQHE) regime (e.g., ${\ensuremath{\nu}}_{\mathit{\text{top}}}=2$) than in the odd IQHE regime (e.g, ${\ensuremath{\nu}}_{\mathit{\text{top}}}=1$). While at higher $B$ fields, the hysteresis at ${\ensuremath{\nu}}_{\mathit{\text{top}}}=1$ becomes the strongest. The switching occurs around the $B$ field at ${\ensuremath{\nu}}_{\mathit{bot}}=3$.
Primary and secondary neopentyl arsines and their reactions with trimethylgallium. Crystal and molecular structure of [Me2GaAs(CH2CMe3)2]2

Abstract The primary and secondary neopentylarsines, NpAsH 2 and Np 2 AsH (Np  CH 2 CMe 3 ) have been prepared from the reaction of the corresponding bromide (NpAsBr 2 and Np 2 AsBr) with lithium aluminum hydride in ether or tetraglyme solution. Reaction of the primary or secondary arsine with GaMe 3 yielded a colorless, crystalline arsino(gallane) with empirical formula Me 2 GaAs(H)Np or Me 2 GaAsNp 2 , respectively. The new compounds have been fully characterized according to elemental analysis, physical and solubility properties, IR, 1 H and 13 C NMR spectroscopies. Single crystal X-ray diffraction studies of Me 2 GaAsNp 2 have shown the compound to be dimeric in the solid stare. The compound [Me 2 GaAsNp 2 ] 2 crystallized in the triclinic space group P 1 with unit cell parameters a =8.688(4), b =9.817(4), c =9.910(4) A, V =774.7(6) A 3 and Z =2. The planar (GaAs) 2 ring of the dimer lies on an inversion center with GaAs bond lengths of 2.529(1) and 2.532(1) A. The endocyclic angles at As and Ga are 94.3(1) and 85.7(1)°, respectively.
REVEALING THE YOUNG STARBURST IN HARO 3 WITH RADIO AND INFRARED IMAGING

The Wolf-Rayet galaxy Haro 3 (Mrk 35, NGC 3353) was observed at the near-IR and radio wavelengths as part of an ongoing program to study the earliest stages of starbursts. These observations confirm that the current episode of star formation is dominated by a single region (region A). While there are knots of recent (~10 Myr) star formation outside of region A, the sources of ionizing radiation as observed in both radio and Brγ observations are almost exclusively associated with region A. The derived ionizing flux implies a star formation rate of ≈0.6 M⊙ yr-1 localized within a radius of ~0.1 kpc. A comparison with HST observations indicates that one or more of the star clusters in region A are optically obscured. The star clusters in region A have ages at least as young as ~5 Myr, and possibly as young as ~0.1 Myr. The star cluster that appears to be the youngest also exhibits a near-IR excess in its colors, possibly indicating natal dust in very close proximity to the ionizing stars. The difference between optical- and radio-determined ionizing fluxes, as well as the near-IR colors, indicates an average extinction value of AV ≈ 2.5 in region A. The total stellar mass associated with the current starburst in region A is inferred from both the near-IR and radio observations to be ~106 M⊙. The other main stellar concentrations observed in the near-IR (regions B1 and B2) are somewhat older than region A, with ages ~8–10 Myr, and the near-IR observations indicate they have stellar masses of ~8 × 104 and ~2 × 104 M⊙, respectively.
The Low-Mass X-Ray Binary X1832–330 in the Globular Cluster NGC 6652: A Serendipitous ASCA Observation

The low-mass X-ray binary (LMXB) X1832-330 in NGC 6652 is one of 12 bright, or transient, X-ray sources to have been discovered in globular clusters. We report on a serendipitous ASCA observation of this globular cluster LMXB, during which a type I burst was detected and the persistent, nonburst emission of the source was at its brightest level recorded to date. No orbital modulation was detected, which argues against a high inclination for the X1832-330 system. The spectrum of the persistent emission can be fitted with a power law plus a partial covering absorber, although other models are not ruled out. Our time-resolved spectral analysis through the burst shows, for the first time, clear evidence for spectral cooling from kT = 2.4 ± 0.6 keV to kT = 1.0 ± 0.1 keV during the decay. The measured peak flux during the burst is ~10% of the Eddington luminosity for a 1.4 M☉ neutron star. These quantities are characteristic of a type I burst, in the context of the relatively low quiescent luminosity of X1832-330.
Constructing Protein Models for Ligand−Receptor Binding Thermodynamic Simulations: An Application to a Set of Peptidometic Renin Inhibitors

Structure-based design is the application of ligand−receptor modeling to predict the activity of a series of molecules that bind to a common receptor for which the molecular geometry is available. Successful structure-based design requires an accurate receptor model which can be economically employed in the design calculations. One goal of the work reported here has been to reduce the size of a model structure of a macromolecular receptor to allow multiple ligand−receptor molecular dynamic (MD) simulations to be computationally economical yet still provide meaningful binding thermodynamic data. A scaled-down 10 A receptor model of the enzyme renin, when subjected to an alternate atomic mass constraint, maintains the structural integrity of the composite parent crystal structure. A second goal of the work has been to develop schemes to explore and characterize the protonation states of receptors and ligand−receptor systems. Application of the charge state characterization schemes to the hydroxyethylene and...
A multiprocessor controlled data acquisition system

Abstract We have designed and constructed a multiprocessor controlled data acquisition system (DAS) to meet the requirements of an extensive air shower array cu
Vertical velocity in shallow convection for different plume types

This study investigates the bulk budgets of the vertical velocity and its parameterization in convective cores, convective updrafts, and clouds by using large-eddy simulation (LES) of four shallow convection cases in the Global Energy and Water Cycle Experiment (GEWEX) Cloud System Study (GCSS) programs. The relative magnitudes of the dominant momentum budget terms for the three types of plumes are presented. For all shallow cumulus except stratocumulus, the buoyancy force and the subplume transport in the core plume are the momentum source that offset the pressure gradient force. In the cloud updraft and cloud plumes, the buoyancy source is dominant in the lower and middle parts of the clouds, while the subgrid transport is a dominant source in the upper part, and the entrainment term is also a momentum source. For the stratocumulus, the subplume transport is a sink almost in the whole convective layer. For all types of plumes, the Simpson and Wiggert (1969) equation is found to be good paramaterization of the mean plume vertical velocity when appropriate scaling coefficients to buoyancy and entrainment terms are used. Optimal forms of the Simpson and Wiggert equation are given for convective cores, convective updrafts, and convective clouds. Results are compared with other studies published in the literature.
Spin correlations in the two-dimensional spin-5/2 Heisenberg antiferromagnet Rb2MnF4

We report a neutron scattering study of the instantaneous spin correlations in the two-dimensional spin S =5/2 square-lattice Heisenberg antiferromagnet Rb2MnF4. The measured correlation lengths are quantitatively described, with no adjustable parameters, by high-temperature series expansion results and by a theory based on the quantum self-consistent harmonic approximation. Conversely, we find that the data, which cover the range from about 1 to 50 lattice constants, are outside of the regime corresponding to renormalized classical behavior of the quantum non-linear model. In addition, we observe a crossover from Heisenberg to Ising critical behavior near the Neel temperature; this crossover is well described by a mean-field model with no adjustable parameters.
Variable threshold detection for 3D page-oriented optical data storage systems

We propose a new method to determine dynamically the threshold in volumetric (3D) page-oriented optical data storage (PODS) systems that use an incoherent (non-holographic) imaging format. In these systems, the inter-symbol interference (ISI) and inter-page interference (IPI) that occurs with very high data packing density are two major sources of error during data retrieval. Traditional readout systems based on a fixed binary decision threshold provide poor results. Our variable threshold detection method identifies the amount of interference from three dimensions for each data element (pixel) and adjusts the threshold value based on that information. In simulation results, the variable threshold method exhibits significant improvement over traditional detection methods.
Virtual zone Navier-Stokes computations for oscillating control surfaces

A new zoning method called 'virtual zones' has been developed for application to an unsteady finite difference Navier-Stokes code. The virtual zoning method simplifies the zoning and gridding of complex configurations for use with patched multi-zone flow codes. An existing interpolation method has been extensively modified to bring the run time for the interpolation procedure down to the same level as for the flow solver. Unsteady Navier-Stokes computations have been performed for transonic flow over a clipped delta wing with an oscillating control surface. The computed unsteady pressure and response characteristics of the control-surface motion compare well with experimental data.
Simple model of the transduction of cell-penetrating peptides

Cell-penetrating peptides (CPPs) such as HIV's trans-activating transcriptional activator (TAT) and polyarginine rapidly pass through the plasma membranes of mammalian cells by an unknown mechanism called transduction. They may be medically useful when fused to well-chosen chains of fewer than about 35 amino acids. The author offers a simple model of transduction in which phosphatidylserines and CPPs effectively form two plates of a capacitor with a voltage sufficient to cause the formation of transient pores (electroporation). The model is consistent with experimental data on the transduction of oligoarginine into mouse C2C12 myoblasts and makes three testable predictions. [Includes supplementary material]
The effect of decision costs on the formation of market-making intermediaries: a pilot experiment

Abstract An economy is presented where trade is beneficial but not assumed. If trade is to occur, it must arise endogenously as either barter or mediated trade. The role decision costs play in the development of trade is explicitly recognized. The theoretical model is examined in an experimental setting by imbedding it in a computer trading game. The data obtained from the experiments are used to examine the impact of decision costs on the development of trade and on the welfare of subjects in the experimental economy.
Formation of Fused Aromatic Architectures via an Oxidative Dearomatization - Radical Cyclization Rearomatization Approach.

Abstract A new mild C–C bond forming cyclization approach of catechol derivatives is reported. This approach relies on an initial dearomatization step using lead(IV) acetate followed by a carefully controlled radical cyclization step, which under the reaction conditions also facilitates rearomatization. Triethylborane is key to the success of this reaction as it enables the reaction to proceed at low temperatures and is also believed to aid rearomatization. The amount and ratio of triethylborane and reducing agent (tributyltinhydride) that is employed as well as the concentration the reaction is run at are all essential to the success of this new approach.
Coherent nuclear diffractive production of minijets — illuminating color transparency

Abstract The cross section for coherent nuclear processes in which an incident meson or photon dissociates diffractively into two jets of high relative transverse momentum (between about 1 and 3 GeV/c) is found to be proportional in QCD to A2 in a wide kinematical region. The leading correction to this is a significant positive term ∝ A 7 3 caused by nuclear multiple scattering. We find also that shadowing of hard diffractive processes reappears as a leading twist effect in the TeV energy range.
An asymptotic expansion related to the Dickman function

We prove a conjecture of Broadhurst on asymptotic expansions of certain polylogarithm type functions related to the Dickman function.
Measuring the Boundary Layer and Inner Accretion Disk Temperatures for WX Ceti During Superoutburst

We obtained EUV photometry, optical spectroscopy, and multicolor optical photometry for WX Cet during its 1998 November superoutburst. WX Cet is only the second short-period, low mass transfer cataclysmic variable (TOAD) to ever be observed in the EUV. Our determined superhump period is consistent with that found by Kato et al. (0.059 day), and we confirm that superhumps are gray in the optical. The optical spectra provide direct evidence that the line emission region is optically thick, and our multiwavelength photometric measurements are used to determine the inner accretion disk and boundary layer temperatures during superoutburst. Using a determined distance to WX Cet of ~130 pc, we find TID = 21,000 K and TBL ~ 72,500 K. Both values are in good agreement with that expected by models of the superoutburst continuum being produced by the inner disk and boundary layer.
High density patterned quantum dot arrays fabricated by electron beam lithography and wet chemical etching

The self-assembly method of forming QDs, although well established as a reliable growth technique, does not allow explicit control over the size and position of each QD. The large size variation of these QDs typically results in significant inhomogeneous broadening, diminishing the potential advantages of their use in optoelectronic devices such as low threshold current density, narrow gain bandwidth, and increased characteristic temperature [1]. Furthermore, the ability to control both the position and spectral properties of a single QD is of great importance for the next generation of nanophotonic devices integrating photonic crystal nanocavities with single QD emitters, which have potential applications in quantum optics and cavity quantum electrodynamics.
Vortical flow computations on swept flexible wings using Navier-Stokes equations

A procedure to couple the Navier-Stokes solutions with modal structural equations of motion is presented for computing aeroelastic responses of swept flexible wings. The Navier-Stokes flow equations are solved by a finite-difference scheme with dynamic grids. The coupled aeroelastic equations of motion are solved using the linear-acceleration method. The configuration-adaptive dynamic grids are time-accurately generated using the aeroelastically deformed shape of the wing. The calculations are compared with the experiment when available. Effects of flexibility, sweep angle, and pitch rate are demonstrated for flows with vortices.