cssi/SciSciGPT-SciSciNet huggingface dataset:
Computing Spatial Information from Fourier Coefficient Distributions

The spatial relationships between molecules can be quantified in terms of information. In the case of membranes, the spatial organization of molecules in a bilayer is closely related to biophysically and biologically important properties. Here, we present an approach to computing spatial information based on Fourier coefficient distributions. The Fourier transform (FT) of an image contains a complete description of the image, and the values of the FT coefficients are uniquely associated with that image. For an image where the distribution of pixels is uncorrelated, the FT coefficients are normally distributed and uncorrelated. Further, the probability distribution for the FT coefficients of such an image can readily be obtained by Parseval’s theorem. We take advantage of these properties to compute the spatial information in an image by determining the probability of each coefficient (both real and imaginary parts) in the FT, then using the Shannon formalism to calculate information. By using the probability distribution obtained from Parseval’s theorem, an effective distance from the uncorrelated or most uncertain case is obtained. The resulting quantity is an information computed in k-space (kSI). This approach provides a robust, facile and highly flexible framework for quantifying spatial information in images and other types of data (of arbitrary dimensions). The kSI metric is tested on a 2D Ising model, frequently used as a model for lipid bilayer; and the temperature-dependent phase transition is accurately determined from the spatial information in configurations of the system.
Electronic aroma detection technology for forensic and law enforcement applications

A major problem hindering criminal investigations is the lack of appropriate tools for proper crime scene investigations. Often locating important pieces of evidence means relying on the ability of trained detection canines. Development of analytical technology to uncover and analyze evidence, potentially at the scene, could serve to expedite criminal investigations, searches, and court proceedings. To address this problem, a new technology based on gas sensor arrays was investigated for its applicability to forensic and law enforcement problems. The technology employs an array of sensors that respond to volatile chemical components yielding a characteristic 'fingerprint' pattern representative of the vapor-phase composition of a sample. Sample aromas can be analyzed and identified using artificial neural networks that are trained on known aroma patterns. Several candidate applications based on known technological needs of the forensic and law enforcement communities have been investigated. These applications have included the detection of aromas emanating from cadavers to aid in determining time since death, drug detection for deterring the manufacture, sale, and use of drugs of abuse, and the analysis of fire debris for accelerant identification. The result to date for these applications have been extremely promising and demonstrate the potential applicability of this technology for forensic use.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The interaction of uterine estrogen receptors with DNA.

The binding of estrogen to specific cytoplasmic and nuclear “receptor” proteins in the uterus is now well established. Temporal analyses of nuclear and cytoplasmic receptor forms following the administration of estradiol indicate that, after its formation in the cell, the cytoplasmic hormone-receptor complex is transferred to the nucleus where it is associated with chromatin material (1–4).
Sub-dekahertz spectroscopy of 199Hg+

Using a laser that is frequency-locked to a Fabry-Perot etalon of high finesse and stability, we probed the 5d106s 2S1/2(F equals O, mF equals O) $ARLR 5d96s22D5/2 (F equals 2, mF equals O) electric-quadrupole transition of a single laser-cooled 199Hg+ ion stored in a cryogenic radio-frequency ion trap. We observed Fourier-transform limited linewidths as narrow as 6.7 Hz at 282 nm (1.06 X 1015 Hz). The functional form and estimated values of some of the frequency shifts of the 2S1/2 $ARLR 2D5/2 clock transition (including the quadrupole shift), which have been calculated using a combination of measured atomic parameters and ab initio calculations, are given.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Stereo 3-D and non-stereo presentations of a computer-generated pictorial primary flight display with pathway augmentation

Stereo 3-D was researched as a means to present cockpit displays which enhance a pilot's situational awareness while maintaining a desirable level of mental workload. The initial study at the NASA Langley Research Center used two different pathways-in-the-sky to augment a computer-generated pictorial primary flight display. One pathway resembled the outline of signposts, while the other pathway resembled a monorail. That display was configured for a curved approach to a landing such as could be used in a Microwave Landing System (MLS) approach. It could also be used for military transports which would have to fly a precision curved pathway. Each trial was initialized with the pilot on the desired flight path. After 2 seconds, he suddenly was shifted to one of eight flight path offsets. The pilot was then required to make the initial pitch and/or roll input to correct back to the nominal flight path. As soon as the input was made, the trial was over. No input was required for control trials with no flight path offset. Pilots responded statistically significantly faster when the display was presented in the stereo version than when it was presented in the nonstereo version.
Enabling Scientific Collaboration and Discovery Through the Use of Data Standardization

The Railgun Data Format Standard (RDFS) provides a flexible format for the archival of electromagnetic railgun (EMRG) laboratory test data. This effort utilizes the hierarchical data format version 5 for the data model and file format, as well as extensible markup language for data structure and data type encapsulation. The RDFS was developed through a collaborative effort within the Office of Naval Research (ONR) EMRG program, including members from the Naval Surface Warfare Center Dahlgren, the Naval Research Laboratory, and the Institute for Advanced Technology. The intent behind the RDFS is to facilitate collaborative data sharing among EMRG researchers through the standardization of EMRG test data archives. The structure of the RDFS is discussed, along with details on its implementation and use within the ONR EMRG community.
Tomographic inversion by matrix transformation

We have developed a new method to build seismic velocity models for complex structures. In our approach, we use a spatially nonuniform parameterization of the velocity model in tomography and a uniform grid representation of the same velocity model in ray tracing to generate the linear system of tomographic equations. Subsequently, a matrix transformation is applied to the system of equations to produce a new linear system of tomographic equations using nonuniform parameterization. In this way, we improved the stability of tomographic inversion without adding computing costs. We tested the effectiveness of our process on a 3D synthetic data example.
Information leakage forces cooperation

Abstract This paper considers a two-person repeated game in which there is a small probability of espionage, i.e., that one or both of the players will be informed of the other's supergame strategy and have a chance to revise his strategy on the basis of this information before the game begins. It is shown that in such a game any subgame perfect equilibrium pair of payoffs is Pareto efficient provided that the probability of espionage is sufficiently small. Different from preceding studies, the present paper assumes neither “collective deviation” nor “bounded rationality” in deriving the result.
Identification of the Diffusion Parameter in Nonlocal Steady Diffusion Problems

The problem of identifying the diffusion parameter appearing in a nonlocal steady diffusion equation is considered. The identification problem is formulated as an optimal control problem having a matching functional as the objective of the control and the parameter function as the control variable. The analysis makes use of a nonlocal vector calculus that allows one to define a variational formulation of the nonlocal problem. In a manner analogous to the local partial differential equations counterpart, we demonstrate, for certain kernel functions, the existence of at least one optimal solution in the space of admissible parameters. We introduce a Galerkin finite element discretization of the optimal control problem and derive a priori error estimates for the approximate state and control variables. Using one-dimensional numerical experiments, we illustrate the theoretical results and show that by using nonlocal models it is possible to estimate non-smooth and discontinuous diffusion parameters.
The Action of the Mapping Class Group on Maximal Representations

Let Γ g be the fundamental group of a closed oriented Riemann surface Σ g , g ≥ 2, and let G be a simple Lie group of Hermitian type. The Toledo invariant defines the subset of maximal representations Repmax(Γ g , G) in the representation variety Rep(Γ g , G). Repmax(Γ g , G) is a union of connected components with similar properties as Teichmuller space $$\mathcal{T}(\Sigma_g) = {\rm Rep}_{\max}(\Gamma_g, {\rm PSL}(2,\mathbb{R}))$$ . We prove that the mapping class group $$Mod_{\Sigma_g}$$ acts properly on Repmax(Γ g , G) when $$G= {\rm Sp}(2n,\mathbb{R})$$ , SU(n,n), SO*(4n), Spin(2,n).
Interaction between Productivity and Measurement

INTRODUCTION Measurement often appears far from benign. Close to home we have the systemwide, at times corrosive effects of student evaluations and popular press rankings. Modern medicine exhibits cycles of advances in measurement, e.g., blood chemistry, followed by development of pharmaceuticals designed to improve those measures. Many are the stories of the athlete more interested in personal than team glory. And then there is the unfolding case of earnings, where we encounter developments in financial engineering and organizational arrangements that seem to have no purpose beyond improving the earnings measure. Economically, we are accustomed to measures being simply a source of information, where Bayesian revision in decision making or valuation and optimal contracting in trading arrangements determine the information’s effect on organizational and individual behavior. Although subtleties surface in a multitask setting, and we know ‘‘bad’’ information can drive out ‘‘good’’ information (e.g., Holmstrom and Milgrom 1991), it seems the story is deeper. A commitment to produce a particular set of measures has the potential to affect the organization’s behavior, to affect productivity, in ways that go beyond traditional information effects. Here we put forward and analyze one such setting. Exactly how the act of measurement produces effects beyond mere information effects is an open question. Our approach is to look to the physical sciences, where measurement is far from benign, and to import the natural effect of measurement in that setting to a human organization. We do not claim this
Dahlberg’s bilinear estimate for solutions of divergence form complex elliptic equations

We consider divergence form elliptic operators L = -div A(x)∇, defined in R n+1 = {(x, t) ∈ R n x R}, n ≥ 2, where the L ∞ coefficient matrix A is (n + 1) x (n + 1), uniformly elliptic, complex and t-independent. Using recently obtained results concerning the boundedness and invertibility of layer potentials associated to such operators, we show that if Lu = 0 in R n+1 + , then for any vector-valued v ∈ W 1,2 loc , we have the bilinear estimate |∫∫ R n+1 + ∇u·vdxdt| ≤ Csup t>0 ∥u(·, t)∥L 2 (R n ) (∥|t∇v∥| + ∥N*v∥L 2 (R n )), where ∥|F∥| ≡ (∫∫ R n+1 + |F(x, t)| 2 t -1 dxdt) 1/2 , and where N* is the usual non-tangential maximal operator. The result is new even in the case of real symmetric coefficients and generalizes an analogous result of Dahlberg for harmonic functions on Lipschitz graph domains. We also identify the domain of the generator of the Poisson semigroup for the equation Lu = 0 in R n+1 + .
On a hidden symmetry of quantum harmonic oscillators

We consider a six-parameter family of the square integrable wave functions for the simple harmonic oscillator, which cannot be obtained by the standard separation of variables. They are given by the action of the corresponding maximal kinematical invariance group on the standard solutions. In addition, the phase space oscillations of the electron position and linear momentum probability distributions are computer animated and some possible applications are briefly discussed. A visualization of the Heisenberg uncertainty principle is presented.
An approach to the segmentation of textured dynamic scenes

An approach to the segmentation of dynamic scenes containing textured objects moving against a textured background is presented. This multistage approach first uses differencing to obtain active regions in the frame which contain moving objects. In the next stage, a Hough transform technique is used to determine the motion parameters associated with each active region. Finally, the intensity changes and the motion parameters are combined to obtain the masks of the moving objects. Our experiments illustrate the efficacy of the approach for moving textured objects even in the presence of occlusion. An indicator that signals the presence of the rotational component of the object motion can also be extracted.
Temperature dependence of exciton Auger decay process in cuprous oxide

Abstract We report a theoretical and experimental study on Auger decay of excitons in Cu 2 O at a wide range of temperatures, from 2 to 325 K, in single-photon surface excitation. We find that the Auger constant linearly increases with temperature above 100 K. This constant is important for experiments on Bose condensation of excitons.
Manganese triacetate mediated oxidation of Hantzsch 1,4-dihydropyridines to pyridines

Abstract A general and practical route for the high yield oxidative conversion of readily accessible 1,4-dihydropyridines to the corresponding pyridines is described using a relatively benign oxidant, manganese triacetate.
An interpretation of the O2 Auger electron spectrum

Abstract The Auger electron spectrum of O 2 is interpreted by comparing with other spectra, such as the photoelectron spectrum, the electron impact mass spectrum, and the double charge transfer spectrum. Each of these four spectra obeys its own selection rule; the difference in the selection rules plays a key role in our interpretation. Auger decays following a core shake-up excitation are identified in the O 2 spectrum for the first time. Many of the previous assignments are revised.
Structural Variation Provided by Sulfur, Sulfinyl, and Sulfonyl Groups in Cyclic Silanes and Phosphoranes

A series of new monocyclic diorganosilanes were prepared by condensation reactions of the appropriate diorganodichlorosilane with sulfur containing diols.1-3 The eight-membered rings containing bridging sulfinyl groups2 are positioned in anti chair-like conformations which precluded any additional coordination at silicon. This contrasts with silanes having sulfur1 or sulfonyl3 groups in place of sulfinyl in the ring system where Si–S or Si–O coordination was evident. In these molecules, X-ray studies showed1,3 that the rings has syn boat-like conformations.
Bordism invariance of the coarse index

We prove bordism invariance of the coarse index of complex elliptic pseudodifferential operators. In our discussion we introduce directed $c$-bordisms, whose usefulness is illustrated in the context of existence of uniformly positive scalar curvature metrics on open manifolds.
Photoferroelectric effects in BaTiO3 crystals

Abstract Intrinsic photo-induced changes in the hysteresis response in BaTiO3 single crystals have been observed by the application of ultra-violet (UV) light in combination with an applied bias. This UV/bias treatment suppresses the amount of switchable polarization by over 90%. The photoferroelectric effects observed are reproducible, reversible, and stable. Electron paramagnetic resonance measurements were also made to characterize the charge trapping associated with these hysteresis effects. The EPR results suggest that isolated Fe impurity sites are charge trapping centers in these crystals, and follow trends similar to those measured electrically. These results also re-enforce the idea that charge trapping centers can lock certain domain configurations.
Anatomy of Female Continence

Abstract Various muscle, connective tissue, and neurologic structures within the pelvic floor play critical roles in the maintenance of both urinary and fecal continence. Recent advances in technology, combined with greater precision during anatomic study, have expanded our understanding of the role played by the pelvic floor in maintaining continence. The goal of this article is to summarize recent research on female pelvic anatomy, with a particular emphasis on the evidence base related to urinary incontinence. The content is organized to accomplish three aims: (1) Identify, within the context of pelvic floor anatomy, the structures that comprise the urinary continence system, (2) Describe the functional dynamics of urinary continence, including factors in resting urethral pressure and pressure transmission, and (3) Present the rationale, technique, and interpretation of various methods of measuring pelvic floor function.
A Helly-Type Theorem for Hyperplane Transversals to Well-Separated Convex Sets

Let S be a finite collection of compact convex sets in \R d . Let D(S) be the largest diameter of any member of S . We say that the collection S is ?-separated if, for every 0 < k < d , any k of the sets can be separated from any other d-k of the sets by a hyperplane more than ? D(S)/2 away from all d of the sets. We prove that if S is an ? -separated collection of at least N(?) compact convex sets in \R d and every 2d+2 members of S are met by a hyperplane, then there is a hyperplane meeting all the members of S . The number N(?) depends both on the dimension d and on the separation parameter ? . This is the first Helly-type theorem known for hyperplane transversals to compact convex sets of arbitrary shape in dimension greater than one.
Oxidations of 3,6‐diamino‐1,2,4,5‐tetrazine and 3,6‐bis(s,s‐dimethylsulfilimino)‐1,2,4,5‐tetrazine

Oxidation of 3,6-diamino-1,2,4,5-tetrazine (1) with most peracids gave 3,6-diamino-1,2,4,5-tetrazine 1,4-dioxide (3) as the major product; however, treatment of (1) with peroxytrifluoroacetic acid (PTFA) gave 3,6-diamino-1,2,4,5-tetrazine 1-oxide (4) as the major product along with a small amount of 3-amino-6-nitro-1,2,4,5-tetrazine 2,4-dioxide (5). Oxidation of 3,6-bis(S,S-dimethylsulfilimino)-1,2,4,5-tetrazine (6) with 3-chloroperoxybenzoic acid (MCPBA) gave 3-S,S-(dimethylsulfili- mino)-6-nitroso-1,2,4,5-tetrazine (7), which was oxidized further with dimethyldioxirane to 3-(S,S-dimethylsulfoximino)-6-nitro-1,2,4,5-tetra- zine (8). All attempts to obtain 3,6-dinitro-1,2,4,5-tetrazine (2) by further oxidation of (7) or (8) failed
IDENTIFICATION OF N-NITROSO- AND NITRODIPHENYLAMINES BY TWO-DIMENSIONAL THIN-LAYER CHROMATOGRAPHY.

Abstract A two-dimensional thin-laye chromatographic method, capable of separating and identifying nineteen N-nitroso- and nitrodiphenylamines, is described. The method is applied to the analysis of diphenylamine/N2O4 an d2-nitroDPA/N2O4 reaction products and the stabilizer fraction of a plastic bonded explosive. A spray reagent, p-diethylaminozaldehyde, used in conjunction with silica gel G/Zn plates, offers a sensitive detection method for each diphenylamine derivative.
Molecular signature of organic nitrogen in septic-impacted groundwater

Dissolved inorganic and organic nitrogen levels are elevated in aquatic systems due to anthropogenic activities. Dissolved organic nitrogen (DON) arises from various sources, and its impact could be more clearly constrained if specific sources were identified and if the molecular-level composition of DON were better understood. In this work, the pharmaceutical carbamazepine was used to identify septic-impacted groundwater in a coastal watershed. Using ultrahigh resolution mass spectrometry data, the nitrogen-containing features of the dissolved organic matter in septic-impacted and non-impacted samples were compared. The septic-impacted groundwater samples have a larger abundance of nitrogen-containing formulas. Impacted samples have additional DON features in the regions ascribed as ‘protein-like’ and ‘lipid-like’ in van Krevelen space and have more intense nitrogen-containing features in a specific region of a carbon versus mass plot. These features are potential indicators of dissolved organic nitrogen arising from septic effluents, and this work suggests that ultrahigh resolution mass spectrometry is a valuable tool to identify and characterize sources of DON.
[2 + 2] Photochemical Cycloaddition/Ring Opening of 6-Alkenyl-2,3-dihydro-4-pyridones

During the course of a study aimed at constructing azaspirocycles from 2,3-dihydro-4-pyridones, an unexpected product was obtained in the SET ring-opening reaction of photocycloadduct 1. Differences in reactivity between homologues 1 and 2 were observed in the presence of SmI2. Tricyclic ketone 2 afforded azaspiro[5.5]undecane 15 when treated with SmI2; however, when ketone 1 was submitted to similar reaction conditions a double ring-opening/reduction sequence gave cis-piperidinol 10.
Advances in f element reductive reactivity as a paradigm for expanding lanthanide and actinide science and technology

Abstract Although f element chemistry has progressed enormously since the time when it was investigated by F.H. Spedding, much still remains to be discovered in this area. This address will describe some recent developments in a fundamental type of f element reaction, reduction, that show just how much new chemistry is still to be discovered in a heavily studied area of f element chemistry that was thought to be mature. This lecture should serve to encourage new efforts to challenge conventional ideas in other “mature” areas of f element science and technology. For 90 years, lanthanide-based reduction chemistry was accomplished with just three divalent ions, Eu 2+ , Yb 2+ , and Sm 2+ . Now there are many new ways to accomplish molecular reductive chemistry equivalent to that of the traditional Ln 2+ ions, but with all the metals in the lanthanide series, La–Lu. Several years ago such an idea would have been unthinkable. This lecture will describe the development of these new types of reduction and their implications in both lanthanide and actinide chemistry.
On the breakdown criterion in general relativity

We give a geometric criterion for the breakdown of an Einstein vacuum space-time foliated by a constant mean curvature, or maximal, foli- ation. More precisely we show that the foliated space-time can be extended as long as the the second fundamental form and the first derivatives of the logarithm of the lapse of the foliation remain uniformly bounded. We make no restrictions on the size of the initial data.
Identifying codes of the direct product of two cliques

An identifying code in a graph is a dominating set that also has the property that the closed neighborhood of each vertex in the graph has a distinct intersection with the set. The minimum cardinality of an identifying code in a graph G is denoted @c^I^D(G). It was recently shown by Gravier, Moncel and Semri that @c^I^D(K"[email protected]?K"n)[email protected][email protected]?. Letting n,m>=2 be any integers, we consider identifying codes of the direct product K"nxK"m. In particular, we answer a question of Klavzar and show the exact value of @c^I^D(K"nxK"m).
Type of Work Matters: Women's Labor Force Participation and the Child Sex Ratio in Turkey

Abstract Province-level census data for 1985 and 1990 from Turkey are used to examine the effect of the economic value of women on the 0–9 cohort population sex ratio. The sex ratio is interpreted as an indicator of the relative life chances of girls, reflecting their relative neglect in the household. We test two hypotheses: women’s labor force participation lowers the sex ratio, and women’s “gainful work outside” is more effective than the not-directly remunerative work in an integrated family production system in lowering the sex ratio. We find an inverse relationship between women’s labor force participation and the sex ratio, but this effect is present only where women engage in unpaid family labor.
A class of perverse sheaves on framed representation varieties of the Jordan quiver

Abstract We study a class of simple perverse sheaves on framed representation varieties of the Jordan quiver in analogy with the one in Li (2013) [17] . We show that the associated local systems are always trivial. We use this class and the top Borel–Moore homology of certain related Steinberg-type varieties to give a geometric realization of the group algebra of a product of symmetric groups, a tensor product of Schur algebras, and a tensor product of Fock spaces.
The structures of 1-, 2- and 3-pyrroline

Abstract The equilibrium structures of 1-, 2- and 3-pyrrolines (C4H7N) have been evaluated by complete geometry optimization using the ab initio gradient method at the Hartree—Fock level with a 4-21 basis set augmented by the addition of polarization functions to the nitrogen atom. The 3-isomer is most stable, with the 2- and 1-pyrrolines being less stable by 3 and 16 kcal mol−1, respectively. There is only one stable conformation for 3-pyrroline, an envelope form with the NH group in the axial position, contrary to a previous conclusion from a far-infrared study which suggested that there is also a less stable equatorial form. Both 1-pyrroline and 2-pyrroline are completely asymmetric, but the ring in the 1-isomer differs only slightly from being completely planar. The ring in the 2-isomer approximates an envelope with a carbon adjacent to the nitrogen atom slightly raised. Variations among the bond lengths and other structural details of the various isomers are discussed.
A Geographic Study of Cosmic Rays

Data are given from measurements of the intensity of cosmic rays by 8 different expeditions at 69 stations distributed at representative points over the earth's surface. Each set of apparatus consisted of a 10 cm spherical steel ionization chamber filled with argon at 30 atmospheres, connected to a Lindemann electrometer, and shielded with 2.5 cm of bronze plus 5.0 cm of lead. Measurements were made by comparing the ionization current due to the cosmic rays with that due to a capsule of radium at a measured distance, the radium standards used with the several sets of apparatus having been intercompared. The method of detecting and correcting for the following disturbing effect is discussed: insulation leak and absorption, local gamma-radiation, radioactive contamination of the ionization chamber, and shielding from cosmic rays by roof and horizon. Intensity vs. barometer (altitude) curves are given for various latitudes. These show not only the rapid increase with altitude noted by previous observers, but also the fact that at each altitude the intensity is greater for high latitudes than near the equator. At sea level the intensity at high latitudes is 14\ifmmode\pm\else\textpm\fi{}0.6 percent greater than at the equator; at 2000 m elevation, 22 percent greater; and at 4360 m, 33 percent greater. This variation follows the geomagnetic latitude more closely than the geographic or the local magnetic latitude, and is most rapid between geomagnetic latitudes 25 and 40 degrees. Consideration of the conditions necessary for deflection of high-speed electrified particles by the earth's magnetic field indicates that if the cosmic rays are electrons, they must originate not less than several hundred kilometers above the earth. The data can be quantitatively explained on the basis of Lemaitre and Vallarta's theory of electrons approaching the earth from remote space. Acknowledgment is made of the cooperation of more than 60 physicists in this program, 25 of whom are named.
United States Department of Energy solar receiver technology development

The United States Department of Energy (DOE), through Sandia National Laboratories, has been conducting a solar thermal receiver technology development program, which maintains a balance between analytical modeling, bench and small-scale testing, and experimentation conducted at scales representative of commercial-size equipment. Central receiver activities emphasize both molten salt-based systems and volumetric air devices. These receivers are expected to be utilized in solar power plants rated between 100 and 200 MWe. Distributed receiver research focuses on liquid metal refluxing devices. These are intended to mate parabolic dish concentrators with Stirling-cycle engines in the 5 to 25 kWe power range. This paper describes recent progress in this development program and discusses future plans.
Determination of internal wave properties from X-Band radar observations

Abstract The application of nautical X-Band radars to measure internal wave (IW) properties is investigated. A methodology based on the use of Radon transform (RT) techniques to detect internal wave related features from backscatter image sequences is introduced to compute properties such as direction of propagation, non-linear velocity ( c 0 ), distance between solitons ( L cc ) and number of solitons per packet. The proposed methodology was applied to several events recorded by a ship-mounted X-Band radar system (WaMoS) during the NLIWI experiment in 2006. Results from the comparisons to simultaneous measurements taken at neighboring oceanographic moorings indicated that c 0 can be estimated with a RMS error of 0.06 m s −1 , which corresponds to a mean relative error of −1.4%. Similarly, L cc can be estimated with a RMS error of 98 m, which is associated with a mean relative error of 14.6%. This latter error estimate however is likely to be overestimated, because it reflects strongly the separation between sampling stations as L cc was shown to be highly dependent on propagation distance. The accuracy of the results shows that X-Band systems are well suited to measure internal wave properties offering some advantages over SAR and other in situ devices.
A 12 Bit 1.6 GS/s BiCMOS 2×2 Hierarchical Time-Interleaved Pipeline ADC

This paper describes a 12 bit 1.6 GS/s pipeline ADC realized in a 0.18 μm complementary BiCMOS SiGe process. The ADC consists of a four-way time-interleaved hierarchical structure and a master-slave T&H to improve the dynamic performance of the individual sub-ADCs and to reduce both the converter error rate and the complexity of the required interleaving background calibration algorithms. It achieves an SFDR of 79 dBc and 66 dBc at low and high frequency inputs, respectively and an error rate of less than 10 -9 , and has a power consumption of 1.15 W for the core ADC.
Surface rheology of hydrophobically modified PEG polymers associating with a phospholipid monolayer at the air-water interface.

Surface rheology of irreversibly bound hydrophobically modified poly(ethylene glycol) (PEG) polymers (HMPEG) on a dipalmitoylphosphatidylcholine (DPPC) monolayer is investigated to determine attributes that may contribute to immune recognition. Previously, three comb-graft polymers (HMPEG136-DP3, HMPEG273-DP2.5, and HMPEG273-DP5) adsorbed on liposomes were examined for their strength of adsorption and protection from complement binding. The data supported an optimal ratio between the hydrophilicity of the PEG polymer and the number of hydrophobic anchors. The HMPEG polymers have different polymer brush thicknesses (4.2−5.9 nm) and levels of cooperativity (2.5−5 hydrophobes). The results indicate that an increased viscous force (above 0.25 mN s/m) at the surface may enable the polymers to shield liposomes from protein interactions. Similar rheological behavior is shown for all polymer architectures at low polymer surface coverage (0.5 mg/m2, in the mushroom regime), whereas at high surface coverage (>0.5 m...
The use of Markov Random Fields as models of texture

Abstract We propose Markov Random Fields (MRFs) as probabilistic models of digital image texture where a textured region is viewed as a finite sample of a two-dimensional random process describable by its statistical parameters. MRFs are multidimensional generalizations of Markov chains defined in terms of conditional probabilities associated with spatial neighborhoods. We present an algorithm that generates an MRF on a finite toroidal square lattice from an independent identically distributed (i.i.d.) array of random variables and a given set of independent real-valued statistical parameters. The parametric specification of a consistent collection of MRF conditional probabilities is a general result known as the MRF-Gibbs Random Field (GRF) equivalence. The MRF statistical parameters control the size and directionality of the clusters of adjacent similar pixels which are basic to texture discrimination and thus seem to constitute an efficient model of texture. In the last part of this paper we outline an MRF parameter estimation method and goodness of fit statistical tests applicable to MRF models for a given unknown digital image texture on a finite toroidal square lattice. The estimated parameters may be used as basic features in texture classification. Alternatively these parameters may be used in conjunction with the MRF generation algorithm as a powerful data compression scheme.
Finite-Temperature Density Instability at High Landau Level Occupancy

We study here the onset of charge density wave instabilities in quantum Hall systems at finite temperature for Landau level filling nu>4. Specific emphasis is placed on the role of disorder as well as on an in-plane magnetic field. Beyond some critical value, disorder is observed to suppress the charge density wave melting temperature to zero. In addition, we find that a transition from perpendicular to parallel stripes (relative to the in-plane magnetic field) exists when the electron gas thickness exceeds approximately 60 A. The perpendicular alignment of the stripes is in agreement with the experimental finding that the easy conduction direction is perpendicular to the in-plane field.
Ion beam sputter deposited zinc telluride films

Zinc telluride is of interest as a potential electronic device material, particularly as one component in an amorphous superlattice, which is a new class of interesting and potentially useful materials. Some structural and electronic properties of ZnTe films deposited by argon ion beam sputter depoairion are described. Films (up to 3000 angstroms thick) were deposited from a ZnTe target. A beam energy of 1000 eV and a current density of 4 mA/sq. cm. resulted in deposition rates of approximately 70 angstroms/min. The optical band gap was found to be approximately 1.1 eV, indicating an amorphous structure, as compared to a literature value of 2.26 eV for crystalline material. Intrinsic stress measurements showed a thickness dependence, varying from tensile for thicknesses below 850 angstroms to compressive for larger thicknesses. Room temperature conductivity measurement also showed a thickness dependence, with values ranging from 1.86 x to to the -6/ohm. cm. for 300 angstrom film to 2.56 x 10 to the -1/ohm. cm. for a 2600 angstrom film. Measurement of the temperature dependence of the conductivity for these films showed complicated behavior which was thickness dependent. Thinner films showed at least two distinct temperature dependent conductivity mechanisms, as described by a Mott-type model. Thicker films showed only one principal conductivity mechanism, similar to what might be expected for a material with more crystalline character.
Analysis of dynamic systems with periodically varying parameters via chebyshev polynomials

A method for the analysis of multidimensional second order dynamic systems with periodically varying parameters is presented. The state vector and the periodic matrices appearing in the equations are expanded in Chebyshev polynomials over the principal period and the original differential problem is reduced to a set of linear algebraic equations. As an example, approximate analytical expressions for the Floquet characteristic exponents of Mathieu's equation are obtained. Numerical solutions for the flap-lag motion of a three bladed helicopter rotor are constructed
Smooth global Lagrangian flow for the 2D Euler and second-grade fluid equations

Abstract We present a very simple proof of the global existence of a C ∞ Lagrangian flow map for the 2D Euler and second-grade fluid equations (on a compact Riemannian manifold with boundary) which has C ∞ dependence on initial data u 0 in the class of H s divergence-free vector fields for s > 2.
Accumulation of PCBs, mercury and cadmium by Nereis virens, Mercenaria mercenaria and Palaemonetes pugio from contaminated harbor sediments

Abstract Accumulation of polychlorinated biphenyls (PCBs), mercury, and cadmium by sandworms ( Nereis virens ), hard clams ( Mercenaria mercenaria ) and grass shrimp ( Palaemonetes pugio ) exposed to contaminated sediments from four sites in New York Harbor was studied for a 100-day period. Of the three contaminants monitored, only PCBs were found to bioaccumulate above background (control) concentrations. Small increases in PCB body burden were detected in M. mercenaria and P. pugio , whereas higher concentrations were measured in N. virens . Uptake was affected by the organic content of the sediment. Bioaccumulation factors (concentration in tissue/concentration in sediment) for N. virens ranged from 1.59 in a low organic sediment to 0.15 in a high organic sediment. Results from this study support the contention that sediment concentration alone does not reflect bioavailability and that toxicity tests (bioassays) and field monitoring remain the most direct method for estimating bioaccumulation potential of sediment-bound contaminants.
JORDAN GROUPS AND ELLIPTIC RULED SURFACES

We prove that an analogue of Jordan’s theorem on finite subgroups of general linear groups holds for the groups of biregular automorphisms of elliptic ruled surfaces. This gives a positive answer to a question of Vladimir L. Popov.
Enhanced gauge symmetry in M(atrix) theory

We discuss the origin of enhanced gauge symmetry in ALE (and K3) compactification of M theory, either defined as the strong coupling limit of the type IIa superstring, or as defined by Banks et al. In the D-brane formalism, wrapped membranes are D0 branes with twisted string boundary conditions, and appear on the same footing with the Kaluza-Klein excitations of the gauge bosons. In M(atrix) theory, the construction appears to work for arbitrary ALE metric.
Modular invariance and characteristic numbers

We prove that a general miraculous cancellation formula, the divisibility of certain characteristic numbers, and some other topological results related to the generalized Rochlin invariant, the η-invariant and the holonomies of certain determinant line bundles, are consequences of the modular invariance of elliptic operators on loop space.
Planar Nets of Ti Atoms Comprising Squares and Rhombs in the New Binary Antimonide Ti2Sb

The new binary antimonide Ti(2)Sb was found to crystallize in a distorted variant of the La(2)Sb type, which contains a square planar La net with short La-La bonds. In the Ti(2)Sb structure, the corresponding Ti net is deformed to squares and rhombs in order to enhance Ti-Ti bonding, as proven by single-crystal X-ray investigation in combination with the real-space pair distribution function technique utilizing both X-ray and neutron powder diffraction data. Electronic structure calculations revealed a lowering of the total energy caused by the disorder, the major driving force being strengthened Ti-Ti interactions along the diagonal of the Ti(4) rhombs.
Foreign activities of U.S. banks since 1997: The roles of regulations and market conditions in crises and normal times

Abstract Using a unique newly constructed dataset on U.S. banks' foreign activities since 1997, this paper examines how bank, market and regulatory conditions in the U.S. and host countries affect U.S. banks' choices of which foreign markets to enter and how much claims and liabilities to take on there. Using a two-stage structural estimation framework, the determinants of foreign market entry/exit, cross-border claims, and foreign affiliate claims and liabilities choices are examined in 107 host countries around the world. It is shown that (1) the health of the balance sheet is the primary driver of foreign market entry/exit choices (especially so during the Subprime crisis), while host market and regulatory conditions play important roles in the choice of claims/liabilities volumes; (2) banks choose their foreign activities during banking and market crises differently than they do in ‘normal’ times; and (3) in addition to bank size, previous experience with managing a global lending network significantly increases the intensity of banks' foreign involvement. Structural estimates of the costs of foreign market entry/exit and host market regulatory stringency are also derived.
The small-world effect: The influence of macro-level properties of developer collaboration networks on open-source project success

In this study we investigate the impact of community-level networks—relationships that exist among developers in an OSS community—on the productivity of member developers. Specifically, we argue that OSS community networks characterized by small-world properties would positively influence the productivity of the member developers by providing them with speedy and reliable access to more quantity and variety of information and knowledge resources. Specific hypotheses are developed and tested using longitudinal data on a large panel of 4,279 projects from 15 different OSS communities hosted at Sourceforge. Our results suggest that significant variation exists in small-world properties of OSS communities at Sourceforge. After accounting for project, foundry, and time-specific observed and unobserved effects, we found a statistically significant relationship between small-world properties of a community and the technical and commercial success of the software produced by its members. In contrast to the findings of prior research, we also found the lack of a significant relationship between closeness and betweenness centralities of the project teams and their success. These results were robust to a number of controls and model specifications.
Crystal Structure, Charge Transport, and Magnetic Properties of MnSb2Se4†

A single phase of MnSb2Se4 was synthesized by combining high-purity elements at 773 K. Single-crystal X-ray diffraction revealed that MnSb2Se4 is isostructural with FeSb2Se4 crystallizing in the monoclinic space group C2/m with a = 13.076(3) A, b = 3.965(2) A, c = 15.236(4) A, β = 115.1(2)°, Z = 4. MnSb2Se4 melts congruently at 790 K and is thermally stable up to 1000 K. Electronic band structure calculations, infrared diffuse reflectance spectroscopy, and low-temperature electronic transport data indicate that MnSb2Se4 is a narrow-bandgap p-type semiconductor with an energy bandgap of approximately 0.31 eV and exhibits a sharp increase in the resistivity near 230 K. A large Seebeck coefficient (S = +945 μV K–1), high electrical resistivity (ρ ≈ 9 Ω m), and low thermal conductivity (κ = 1.4 W m–1 K–1) were observed at 300 K. Direct current (DC) magnetic-susceptibility measurements indicated that MnSb2Se4 is paramagnetic at 300 K and undergoes an order/disorder antiferromagnetic transition with a Neel temperature of approximately 20 K. Alternating current (AC) susceptibility at various frequencies suggested a spin-glass-like behavior.
DNA Structure Selectivity of Escherichia coli versus Thermus aquaticus DNA Polymerase I

Understanding substrate selection by DNA Polymerase I is important for characterizing the balance between DNA replication and repair for this enzyme in vivo. Due to their sequence and structural similarities, Klenow and Klentaq, the “large fragments” of the Pol I DNA polymerases from Escherichia coli and Thermus aquaticus, are considered functional homologues. We have examined the DNA binding thermodynamics of Klenow and Klentaq to different DNA structures: single-stranded DNA (ss-DNA), primer-template DNA (pt-DNA), and double-stranded DNA (ds-DNA). The DNA binding affinity trend for Klenow from weakest to tightest binding is ds-DNA < pt-DNA < ss-DNA. This is in contrast to Klentaq's DNA binding trend: ss-DNA < pt-DNA ≈ ds-DNA. Both Klenow and Klentaq released more ions when binding to pt-DNA and ds-DNA than when binding to ss-DNA in KCl buffer. ΔCp is the temperature dependence of the enthalpy of a reaction. Both of these non-sequence specific binding proteins exhibit relatively large heat capacity changes (ΔCp) upon DNA binding. ΔCp values for binding of Klenow and Klentaq to the different DNA structures do not follow the same patterns as the ΔG values for binding, suggesting the balance of electrostatic versus hydrophobic interactions in the binding interfaces also differ between the two species of polymerase. It is also found that Mg2+ significantly shifts the ds-DNA binding affinity of Klenow, but not Klentaq. Mg2+ may be shifting the partitioning between the polymerization and editing sites on Klenow. The differences in DNA structural selectivity of the two polymerases suggest that the in vivo functions of these two supposedly homologous polymerases are different, and that Taq polymerase is more likely to be involved in ds-break repair and end-preservation in vivo. Funded by the NSF and the Louisiana Biomedical Research Network.
Search for positively charged strangelets and other related results with E864 at the AGS

We report on the latest results in the search for positively charged strangelets from the E864 96/97 run at the AGS with sensitivity of about 8 × 10−9 per central collision. This contribution also contains new results of a search for highly charged strangelets with Z = +3. Production of light nuclei, such as 6He and 6Li, is presented as well. Measurements of yields of these rarely produced isotopes near midrapidity will help constrain the production levels of strangelets via coalescence. E864 also measures antiproton production which includes decays from antihyperons. Comparisons with antiproton yields measured by E878 as a function of centrality indicate a large antihyperon-to-antiproton ratio in central collisions.
The Gospel According to Mormon

Although scholarly investigation of the Book of Mormon has increased significantly over the last three decades, only a tiny portion of that effort has been focused on the theological or doctrinal content of this central volume of Latter-day Saints (LDS) scripture. This article identifies three inclusios which promise definitions of the doctrine or gospel of Jesus Christ and proposes a cumulative methodology to explain how these definitions work. This approach reveals a consistently presented, six-part formula defining ‘the way’ by which mankind can qualify for eternal life. In this way the article provides a starting point for scholarly examinations of the theological content of this increasingly influential religious text. While the names of the six elements featured in Mormon's gospel will sound familiar to students of the New Testament, the meanings he assigns to these may differ substantially from traditional Christian discourse in ways which make Mormon's characterization of the gospel or doctrine of Christ unique. (1) Faith is understood primarily as action displaying complete trust or reliance on Christ and the power of his atonement. (2) Repentance requires turning away