cssi/SciSciGPT-SciSciNet huggingface dataset:
Phase-Only Image Reconstruction From Offset Fourier Data

In a recent paper we investigated the problem of reconstructing the magnitude of a 2-D complex signal f from samples of the Fourier transform of f lying in a small region offset from the origin. The primary application of interest was synthetic aperture radar. We showed that high quality speckle reconstructions are possible so long as the phase of f is highly random. In this paper we explore the possibility of Fourier-offset reconstruction from just the phase of the Fourier transform. We provide and compare a large number of computer-simulated image reconstructions from phase plus magnitude, phase only (constant magnitude), magnitude only (zero phase), and magnitude plus quantized phase. A number of conclusions are drawn regarding Fourier offset phase-only reconstruction, and several topics are suggested for further research.
Sensory behavior of ionic polymer metal composite

The sensor/transducer of interest here is the Ionic Polymer-Metal Composite (IPMC). In this paper, we attempt to model the IPMC as a parallel connected RC circuit ascertaining that the charges generated out of IPMC are proportional to the velocity on each capacitor. A damped electric response is observed which is highly repeatable. This also makes IPMCs effective for large motion sensors. Experiments were conducted using IPMC samples with various lengths, width of 10 mm and various thicknesses. The cations used for these experiments were Na+, Li+, and K+. IPMCs have been shown to be an attractive solution for unique problems requiring a transducer for sensing in applications such as large motion sensing or damping.
Applications of peptide and protein-based materials in bionanotechnology

In this critical review we highlight recent advances in the use of peptide- and protein-related materials as smart building blocks in nanotechnology. Peptides and proteins can be very practical for new material synthesis and device fabrications. For example, peptides and proteins have superior specificity for target binding as seen in the antibody recognition and this biological recognition function can be used to assemble them into specific structures and shapes in large scale, as observed in the S-layer protein assembly. Collagens are assembled from triple helix peptides in micron-size with precise recognition between peptides and these biological assemblies can undergo smart structural change with pH, ionic strength, temperature, electric/magnetic fields. In addition, assemblies of peptides can template complex 3D crystallization processes with catalytic function, thus enabling to grow various materials in physiological conditions at low temperature in aqueous solution. The biomimetic growth of nanomaterials in aqueous solution is extremely useful when they are applied to therapeutics and medical imaging in vivo since these nanomaterials will be well dispersed in bodies. Peptides also play significant roles in signal transduction pathways in cells. For example, neuropeptides are used as neurotransmitters between synapses and these peptides bind receptors on the surface of cells to cascade the signal transduction. These versatile functions of peptides are extremely practical and here we discuss them with examples of relevant applications such as nanoreactors, sensors, electronics, and stimulus-responsive materials. It should be noted that peptide/protein assemblies can be applied to build up micron-scale materials that still feature excellent nano-scale ensembles, which essentially bridges the nano-world and the micro-world (86 references).
Methyl 2,3,4,6-tetra-O-(4-methoxybenzyl)-1-thio-β-D-glucopyranoside-a novel reagent for α-glycosylation towards nitrophenyl or benzyl glycosides

Abstract A stereoselective synthesis of α-D-glucopyranosyl linked oligosaccharides containing a anomeric 4-nitrophenyl or benzyl group was accomplished through the use of methyl 2,3,4,6-tetra-O-(4-methoxybenzyl-1-thio-β-D-glucopyranoside ( 4 ) as a key glycosyl donor.
Using Preimplantation Genetic Diagnosis to Create a Stem Cell Donor: Issues, Guidelines & Limits:

Successful preimplantation genetic diagnosis (PGD) to avoid creating a child affected by a genetically-based disorder was reported in 1989. Since then PGD has been used to biopsy and analyze embryos created through in viuo fertilization (IVF) to avoid transferring to the mother’s uterus an embryo affected by a mutation or chromosomal abnormality associated with serious illness. PGD to avoid serious and early-onset illness in the child-to-be is widely accepted. PGD prevents gestation of an affected embryo and reduces the chance that the parents will be faced with a difficult decision of whether to terminate the pregnancy. More controversial have been PGD to select the sex of the child-to-be for “family balancing” (rather than to avoid a sex-linked disorder), PGD for mere susceptibility to disease and for late-onset disorders such as Alzheimer diseas, and most controversially, PGD to create a donor child who is Human Leukocyte Antigen (HLA-matched with a preexisting sibling in need of stem cell transplant.
Free meixner states

Free Meixner states are a class of functionals on non-commutative polynomials introduced in [Ans06]. They are characterized by a resolvent-type form for the generating function of their orthogonal polynomials, by a recursion relation for those polynomials, or by a second-order non-commutative differential equation satisfied by their free cumulant functional. In this paper, we construct an operator model for free Meixner states. By combinatorial methods, we also derive an operator model for their free cumulant functionals. This, in turn, allows us to construct a number of examples. Some of these examples are shown to be trivial, in the sense of being free products of functionals which depend on only a single variable, or rotations of such free products. On the other hand, the multinomial distribution is a free Meixner state and is not a product. Neither is a large class of tracial free Meixner states which are analogous to the simple quadratic exponential families in statistics.
Network Localization on Unit Disk Graphs

We study the problem of cooperative localization of a large network of nodes in integer-coordinated unit disk graphs, a simplified but useful version of general random graph. Exploiting the property that the radius $r$ sets clear cut on the connectivity of two nodes, we propose an essential philosophy that ``no connectivity is a useful information'' in unit disk graphs. Exercising this philosophy, we show that the conventional network localization problem can be re-formulated to significantly reduce the search space, and that global rigidity, a necessary and sufficient condition for the existence of unique solution in general graphs, is no longer necessary. While the problem is still NP-hard, we show that a (depth-first) tree-search algorithm with memory $O(N)$ ($N$ is the network size) can be developed, and for practical setups, the search complexity and speed is very manageable, and is magnitudes less than the conventional problem, especially when the graph is sparse or when only very limited anchor nodes are available.
Learning temporal patterns by redistribution of synaptic efficacy

Abstract Recent experiments have shown that neocortical synapses exhibit both short-term plasticity and spike-timing dependent long-term plasticity. It has been suggested that changes in short-term plasticity are mediated by a redistribution of synaptic efficacy. Here we propose a simple model of the interaction between spike-timing dependent plasticity and short-term plasticity. We show that the model captures the synaptic behavior seen in experiments on redistribution of synaptic efficacy. Results from our simulations suggest that spike-timing dependent redistribution of synaptic efficacy offers neocortical neurons a potentially powerful mechanism for learning spatiotemporal patterns in the input stream.
Anomalous behavior of the upper critical field in extreme type-II superconductors at low temperatures

Abstract We present a detailed numerical calculation of the upper critical field H c 2 ( T ) for a bulk extreme type-II superconductor. Particular emphasis is placed on the high-field, low-temperature regime of the HT -phase diagram. In this regime, it is necessary to go beyond the standard semi-classical theory and include the effects of Landau quantization of the electronic motion on the superconducting state. The presence of Landau level quantization induces an upward curvature in H c 2 ( T ) at ∼10% of T c 0 for those superconducting systems in which the slope of H c 2 ( T ) at T c 0 is ≥0.2 T/K. We construct a simple analytical model that can account for this behavior based on the renormalization of the BCS coupling constant by the off-diagonal pairing of electrons on Landau levels.
The emerging migration state

Since 1945, immigration in the core industrial democracies has been increasing. The rise in immigration is a function of market forces (demand-pull and supply-push) and kinship networks, which reduce the transaction costs of moving from one society to another. These economic and sociological forces are the necessary conditions for migration to occur, but the sufficient conditions are legal and political. States must be willing to accept immigration and to grant rights to outsiders. How then do states regulate migration in the face of economic forces that push them toward greater openness, while security concerns and powerful political forces push them toward closure? States are trapped in a liberal paradox - in order to maintain a competitive advantage, governments must keep their economies and societies open to trade, investment, and migration. But unlike goods, capital, and services, the movement of people involves greater political risks. In both Europe and North America, rights are the key to regulating migration as states strive to fulfill three key functions: maintaining security; building trade and investment regimes; and regulating migration. The garrison state was linked with the trading state in the eighteenth and nineteenth centuries. The twentieth and twenty-first centuries have seen the emergence of the migration state, where regulation of international migration is as important as providing for the security of the state and the economic well being of the citizenry
Bioaccumulation of mercury and methylmercury

The factors controlling the accumulation of mercury in fish are poorly understood. The oil invoked lipid solubility of MMHg is an inadequate explanation because inorganic Hg complexes, which are not bioaccumulated, are as lipid soluble as their MMHg analogs and, unlike other hydrophobic compounds, MMHg in fish resides in protein rather than fat tissue. We show that passive uptake of the lipophilic complexes (primarily HgCl2 and CH3HgCl) results in high concentrations of both inorganic and MMHg in phytoplankton. However, differences in partitioning within phytoplankton cells between inorganic mercury — which is principally membrane bound — and MMHg — which accumulates in the cytoplasm — lead to a greater assimilation of MMHg during zooplankton grazing. Most of the discrimination between inorganic and MMHg thus occurs during trophic transfer while the major enrichment factor is between water and phytoplankton. As a result, MMHg concentrations in fish are ultimately determined by water chemistry which controls MMHg speciation and uptake at the base of the food chain.
Predicting the Entropy of Boiling for Organic Compounds

This study aims to predict the entropy of boiling (ΔSb) for organic compounds by considering parameters that are indicative of both molecular geometry and molecular association. The proposed method is a modification of Trouton's rule. It utilizes three geometric parameters, σ, τ, and ω, that address molecular symmetry, flexibility, and planarity, respectively, as well as a set of group contributors that focus on hydrogen-bonding and strong dipolar interactions. The molecular geometry parameters are unique in that they reflect the ordering of molecules in the liquid that cannot be described by group contribution. The database of 903 organic compounds covers a broad array of structural categories. The root mean square error for the prediction is 2.12 J/mol·K, which is very low given the diversity of the database. An independent entropy dataset of 31 compounds was used to show that the proposed method is more accurate than four published methods. The success of this approach illustrates the need for nonaddit...
Modeling of surface tension effects in venturi scrubbing

Abstract A modified model of venturi scrubber performance has been developed that addresses two effects of liquid surface tension: its effect on droplet size and its effect on particle penetration into the droplet. The predictions of the model indicate that, in general, collection efficiency increases with a decrease in liquid surface tension, but the range over which this increase is significant depends on the particle size and on the scrubber operating parameters. The predictions further indicate that the increases in collection efficiency are almost totally due to the effect of liquid surface tension on the mean droplet size, and that the collection efficiency is not significantly affected by the ability of the particle to penetrate the droplet.
Diagnostic reasoning with A-Prolog

In this paper, we suggest an architecture for a software agent which operates a physical device and is capable of making observations and of testing and repairing the device's components. We present simplified definitions of the notions of symptom, candidate diagnosis, and diagnosis which are based on the theory of action language ${\cal AL}$. The definitions allow one to give a simple account of the agent's behavior in which many of the agent's tasks are reduced to computing stable models of logic programs.
Synthesis of zinc, cadmium, tin, and silicon derivatives of cubane

Abstract Metallocubanes are shown to be available by a transmetalation procedure in which amide-activated cubanes are treated with LiTMP and a metal chloride. They are excellent precursors for new subsituted cubanes.
Some Examples of Pilot/Vehicle Dynamics Identified from Flight Test Records

This communication illustrates a simple technique for identifying the pilot/vehicle describing functions from routine flight test records. This technique provides a straightforward method of analyzing and comparing the dynamics of closed-loop attitude control tasks from actual flight test operations. Some results from the Gemini and X-15 flight test records tend to confirm previous findings that the pilot tries to adjust his dynamics such that the combined pilot/vehicle describing function can be described by a simple crossover model.
Quantum computing with magnetically interacting atoms

We propose a scalable quantum-computing architecture based on cold atoms confined to sites of a tight optical lattice. The lattice is placed in a nonuniform magnetic field and the resulting Zeeman sublevels define qubit states. Microwave pulses tuned to space-dependent resonant frequencies are used for individual addressing. The atoms interact via magnetic-dipole interactions allowing implementation of a universal controlled-NOT gate. The resulting gate operation times for alkalis-metals are on the order of milliseconds, much faster then the anticipated decoherence times. Single qubit operations take about $10\phantom{\rule{0.3em}{0ex}}\mathrm{\ensuremath{\mu}s}$. Analysis of motional decoherence due to NOT operations is given. We also comment on the improved feasibility of the proposed architecture with complex open-shell atoms, such as Cr, Eu, and metastable alkaline-earth atoms with larger magnetic moments.
A Data Structure for Dynamically Maintaining Rooted Trees

The directed topology tree data structure is developed for maintaining binary trees dynamically. Each of a certain set of tree operations is shown to takeO(logn) time, wherenis the number of vertices in the trees. The directed topology trees are used to implement link?cut trees and dynamic expression trees. The results of experimental comparisons with the dynamic trees of Sleator and Tarjan are presented.
Multiwavelength Observations of GX 339–4 in 1996. II. Rapid X-Ray Variability

As part of our multiwavelength campaign of GX 339-4 observations in 1996, we present the rapid X-ray variability observed on July 26 using the Rossi X-Ray Timing Explorer (RXTE) when the source was in a hard state (=soft X-ray low state). We found that the source was extremely variable, with many bright flares. The flares have relatively symmetric time profiles. There are a few time intervals in which the flux rises steadily and then drops suddenly, sometimes to a level lower than the average before the increase. Hardness ratios showed that the source was slightly softer when the flux was brighter. The power density spectra (PDS) were also complicated, and we found that broken power laws do not provide adequate fits to any of them. Instead, a pair of zero-centered Lorentzians gives a good general description of the shape of the PDS. We found several quasi-periodic oscillations (QPOs), including some that are harmonically spaced, with the most stable frequency at 0.35 Hz. While the overall rms variability of the source was close to being constant throughout the observation (~29% integrating between 0.01 and 50 Hz), there is a small but significant change in the PDS shape with time. More importantly, we show that the soft 2-5 keV band is more variable than the harder 5-10 and 10-40 keV bands, which is unusual for this source and for other black hole candidates. Cross-correlation functions (CCFs) between these bands show that the light curve for the 10-40 keV band lags that of the 2-5 keV band by ~5 ms.
Preferential uptake of estradiol by the anterior hypothalamus of the rat.

Adult ovariectomized rats were injected with a small dose of tritium-labeled estradiol and the uptake and retention of radioactivity in various parts of the brain were measured. The anterior hypothalamus and median eminence showed a characteristic pattern of uptake and retention of radioactivity similar to that shown by the uterus and vagina. The radioactivity taken up was extracted and shown to be largely estradiol itself. Other parts of the brain, which did not selectively take up and retain radioactivity, either converted a relatively larger fraction of the estradiol to estrone and other products or took up estrone made elsewhere in the body from the injected estradiol. The anterior hypophysis was also shown in these experiments to take up and retain estradiol and to convert only a small fraction of it to estrone. The selective uptake and retention of estradiol by the anterior hypothalamus and median eminence suggests a means by which the hormone could initiate the sequence of reactions by which it exe...
Ablative material response to CO2 laser radiation

Ablative materials performance in high radiative heat flux environments produced by CW carbon dioxide laser
Simulation of a Moving Elastic Beam Using Hamilton's Weak Principle

A proof-of-concept algorithm for calculating the general motion of elastic beams in the context of a multibody system analysis has been developed and validated. The governing equations for moving elastic beams with closed cross sections have been formulated using Hamilton’s law of varying action. They are then discretized with a mixed space–time finite element scheme, which results in a system of nonlinear algebraic equations. These equations are solved using unconstrained optimization techniques, thereby obtaining steady-state and time-accurate solutions for linear and nonlinear structural dynamics problems. Solutions obtained for a variety of static, steady-state, and transient test cases have demonstrated the accuracy of the formulation. Illustrative examples, including the cantilever elastica problem, rotation of a beam at a constant angular velocity, and prescribed flapping motion of a beam, are presented.
The Allyl Leaving Group Approach to Tricoordinate Silyl, Germyl, and Stannyl Cations

A group 14 atom bonded to three mesityl groups (2,4,6-trimethylphenyl) and to one allyl group serves as a novel precursor to tricoordinate group 14 cations, the analogues of the carbocation. The double bond of the allyl group provides an accessible reaction site that is located beyond the ortho methyl groups. Reaction of various electrophiles with the double bond releases the allyl group and leads to formation of the group 14 cations. The mesityl groups then are of sufficient steric bulk to protect the tricoordinate metal center from attack by nucleophiles. This approach is used herein with silicon, germanium, and tin as the central atom. The 29Si chemical shift (δ 225) indicates full cationic character for the silicon system. The 119Sn chemical shift (δ 806) indicates less than full cationic character for the tin system. The positive charge for the germanium system has been assessed by examination of the aromatic 13C chemical shifts. These results provide the highest current cationic character for silyli...
Synthesis and transporter binding properties of bridged piperazine analogues of 1-[2-[bis(4-fluorophenyl)methoxy]ethyl]-4-(3-phenylpropyl)piperazine (GBR 12909).

A series of analogues related to 1-[2-(diphenylmethoxy)ethyl]-4-(3-phenylpropyl)piperazine (2) and 1-?2-[bis(4-fluorophenyl)methoxy]ethyl?-4-(3-phenylpropyl)piperazine (3) (GBR 12935 and GBR 12909, respectively), in which the piperazine moiety was replaced by bridged piperazines for structural rigidity, has been designed, synthesized, and evaluated for their ability to bind to the dopamine transporter (DAT) and to inhibit the uptake of (3)H-labeled dopamine (DA). The binding data indicated that compounds 7 and 11, the N-methyl- and N-propylphenyl-3,8-diaza[3.2. 1]bicyclooctane analogues of 3, showed high affinity for the DAT (IC(50) = 8.0 and 8.2 nM, respectively), and 7 had high selectivity at the DAT relative to the serotonin transporter (SERT) (88- and 93-fold for binding and reuptake, respectively). They also displayed linear activity in DA uptake inhibition, possessing a similar binding and reuptake inhibition profile to 3. The N-indolylmethyl analogue 16 showed the highest affinity (IC(50) = 1.4 nM) of the series, with a 6-fold increase over its corresponding N-phenypropyl derivative 11. Interestingly, this compound exhibited a high ratio (29-fold) of IC(50) for the inhibition of DA reuptake versus binding to the DAT. Replacing the piperazine moiety of 2 and 3 with (1S, 4S)-2,5-diazabicyclo[2.2.1]heptane resulted in compounds 23-26, which showed moderate to poor affinity (IC(50) = 127-1170 nM) for the DAT. Substitution of the homopiperazine moiety of 4 with a more rigid 3,9-diazabicyclo[4.2.1]nonane gave compounds 28-33. However, the binding data showed that compound 32 displayed a 10-fold decrease in affinity at the DAT and a 100-fold decrease in selectivity at the DAT relative to the SERT compared to its corresponding homopiperazine compound 4.
Optimal finite-thrust rendezvous trajectories found via particle swarm algorithm

The particle swarm optimization technique is a population-based stochastic method developed in recent years and successfully applied in several fields of research. The particle swarm optimization methodology aims at taking advantage of the mechanism of information sharing that affects the overall behavior of a swarm, with the intent of determining the optimal values of the unknown parameters of the problem under consideration. This research applies the technique to determining optimal continuous-thrust rendezvous trajectories in a rotating Euler–Hill frame. Five distinct applications, both in two dimensions and in three dimensions, are considered. Hamiltonian methods are employed to translate the related optimal control problems into parameter optimization problems. The transversality condition, which is an analytical condition that arises from the calculus of variations, is proven to be ignorable for these problems, and this property greatly simplifies the solution process. For each of the five applicati...
New chemistry of cyclic, s-trans-enaminones: Addition of grignard reagents to enaminones derived from 2-methylcyclohexane-1,3-dione

Abstract Grignard reagents add to cyclic s-trans enaminones to give the cycloalkenone after aqueous hydrolysis. In some cases a competitive double addition takes place. These reactions have been found to be solvent- and reagent-selective.
Aging and holography

Aging phenomena are examples of ‘non-equilibrium criticality’ and can be exemplified by systems with Galilean and scaling symmetries but no time translation invariance. We realize aging holographically using a deformation of a non-relativistic version of gauge/gravity duality. Correlation functions of scalar operators are computed using holographic real-time techniques, and agree with field theory expectations. At least in this setup, general aging phenomena are reproduced holographically by complexifying the bulk space-time geometry, even in Lorentzian signature.
Black holes, wormholes, and the disappearance of global charge

Abstract One of the paradoxes associated with the theory of the formation and subsequent Hawking evaporation of a black hole is the disappearance of conserved global charges. It has long been known that metric fluctuations at short distances (wormholes) violate global-charge conservation; if global charges are apparently conserved at ordinary energies, it is only because wormhole-induced global-charge-violating terms in the low-energy effective Lagrangian are suppressed by large mass denominators. However, such suppressed interactions can become important at the high energy densities inside a collapsing star. We analyze this effect for a simple model of the black-hole singularity. (Our analysis is totally independent of any detailed theory of wormhole dynamics; in particular it does not depend on the wormhole theory of the vanishing of the cosmological constant.) We find that in general all charge is extinguished before the infalling matter crosses the singularity. No global charge appears in the outgoing Hawking radiation because it has all gone down the wormholes.
The correlation between parity and quadratic polynomials mod 3

We prove exponentially small upper bounds on the correlation between parity and quadratic polynomials mod 3. One corollary of this is that in order to compute parity, circuits consisting of a threshold gate at the top, mod 3 gates in the middle, and AND gates of fan-in two at the inputs must be of size 2Ω(n). This is the first result of this type for general mod 3 subcircuits with ANDs of fan-in greater than 1. This yields an exponential improvement over a long-standing result of Smolensky, answering a question recently posed by Alon and Beigel. The proof uses a novel inductive estimate of the relevant exponential sums introduced by Cai. Green and Thierauf. The exponential sum and correlation bounds presented here are tight.
Donor-specific transfusions in living-related transplantation.

Two-hundred thirty-nine transplants have been performed following donor-specific blood transfusions (DSTs) from 1978 through 1984 at the University of California, San Francisco (UCSF). The results of this experience show that DST provides excellent long-term graft survival in 1-haplotype mismatched pairs. Excellent graft survival has also been obtained in a limited 0-haplotype matched experience. These results are comparable to those achieved with concurrent HLA-identical sibling transplants. Azathioprine coverage during DST administration does appear to decrease DST sensitization to the blood donor in unsensitized patients undergoing a first transplant, encouraging early DST and transplantation in this group. The majority of patients formerly excluded from transplantation because of a post-DST positive B-warm crossmatch can now be successfully transplanted with the use of flow cytometry analysis to rule out previously undetectable low levels of anti-class I antigen activity. The DST protocol by itself does not appear to preclude subsequent cadaveric transplantation in patients sensitized to their blood donor by the DST procedure. Preliminary results of cyclosporin treatment in 1-haplotype matched living-related donor-recipient pairs is reported with a 1-year graft survival rate that is similar to that obtained following cadaveric transplantation at this same center. In summary, the long-term immunologic effect of DST has been confirmed, and the indications and considerations for the optimum use of the DST protocol appear to be more clearly defined.
Variations in the Use of Prostate Cancer Staging Tests: Results From One NCCN Institution

Medical care for prostate cancer accounts for as much as $26 billion in medical expenditures. There is debate about whether urologists who treat a large number of cases of prostate cancer use medical resources more efficiently than do urologists who treat fewer patients. This study focuses on one aspect of this debate by addressing the following issue: Are men with prostate cancer more likely to undergo noninvasive staging tests when they are treated by urologists who have higher caseloads than urologists with lower caseloads? Our study identified variations in patterns of ordering staging tests for prostate cancer. The finding supports the use of guidelines. Adherence to the guidelines is likely to be associated with more efficient use of medical resources by physicians with lower caseloads of prostate cancer.
An Eulerian–Lagrangian Approach¶to the Navier–Stokes Equations

We present a formulation of the incompressible viscous Navier–Stokes equation based on a generalization of the inviscid Weber formula, in terms of a diffusive “back-to-labels” map and a virtual velocity. We derive a generalization of the inviscid Cauchy formula and obtain certain bounds for the objects introduced.
Relation of a Contracting Earth to the Apparent Accelerations of the Sun and Moon

The tidal theory of the evolution of the lunar orbit has remained inconsistent with the observational values of the apparent secular accelerations of the Sun and Moon since it was first developed by Jeffreys in 1920. Allowance for a changing moment of inertia of the Earth enables the discrepancy to be completely removed if a decrease is occurring at a rate of just about the amount already required by the phase-change theory of the nature of the terrestrial core. The agreement of the resulting theory with the latest determinations of the lunar acceleration increases confidence in the phase-change hypothesis. On the other hand the theory renders it most unlikely that a changing constant of gravitation will prove necessary to account for the observations. On the present theory of itself the Moon would have been extremely close to the Earth only about 109 years ago which suggests that some additional process may at times have influenced the lunar orbit.
Cell decomposition for semibounded p-adic sets

We study a reduct $${\mathcal{L}_*}$$ of the ring language where multiplication is restricted to a neighbourhood of zero. The language is chosen such that for p-adically closed fields K, the $${\mathcal{L}_*}$$ -definable subsets of K coincide with the semi-algebraic subsets of K. Hence structures (K, $${\mathcal{L}_*}$$ ) can be seen as the p-adic counterpart of the o-minimal structure of semibounded sets. We show that in this language, p-adically closed fields admit cell decomposition, using cells similar to p-adic semi-algebraic cells. From this we can derive quantifier-elimination, and give a characterization of definable functions. In particular, we conclude that multiplication can only be defined on bounded sets, and we consider the existence of definable Skolem functions.
Search for Patterns of Functional Specificity in the Brain: A Nonparametric Hierarchical Bayesian Model for Group fMRI Data

Functional MRI studies have uncovered a number of brain areas that demonstrate highly specific functional patterns. In the case of visual object recognition, small, focal regions have been characterized with selectivity for visual categories such as human faces. In this paper, we develop an algorithm that automatically learns patterns of functional specificity from fMRI data in a group of subjects. The method does not require spatial alignment of functional images from different subjects. The algorithm is based on a generative model that comprises two main layers. At the lower level, we express the functional brain response to each stimulus as a binary activation variable. At the next level, we define a prior over sets of activation variables in all subjects. We use a Hierarchical Dirichlet Process as the prior in order to learn the patterns of functional specificity shared across the group, which we call functional systems, and estimate the number of these systems. Inference based on our model enables automatic discovery and characterization of dominant and consistent functional systems. We apply the method to data from a visual fMRI study comprised of 69 distinct stimulus images. The discovered system activation profiles correspond to selectivity for a number of image categories such as faces, bodies, and scenes. Among systems found by our method, we identify new areas that are deactivated by face stimuli. In empirical comparisons with previously proposed exploratory methods, our results appear superior in capturing the structure in the space of visual categories of stimuli.
Evaluating Micromechanical Properties at Surfaces Using Nanoindentation with Finite-Element Modeling:

Detailed finite-element modeling of nanoindentation data is used to obtain accurate mechanical properties of very thin films or surface-modified layers independently of the properties of the underlying substrates. These procedures accurately deduce the yield strength, elastic modulus, and layer hardness, and greatly increase the usefulness of indentation testing with very thin surface layers. Moreover, extraction of the effective Young's modulus in the near surface region should enable mechanical damage studies on a small scale. This paper presents a brief overview of the procedures involved and illustrates them with He-implanted Ni.
Traffic assignment considering air quality

This paper presents a methodology of assigning traffic in a network with the consideration of air quality. Traffic assignment is formulated as an optimization problem considering travel cost and on-road emissions. It introduces a cell-based approach to model emission concentrations so that either the average or maximum emissions in a network can be considered in the optimization process. The emissions in a cell are modeled taking into consideration the influence of the emission sources from all cells in the network. A case study demonstrates that minimizing travel cost and reducing air pollutants may not be always achieved simultaneously. The traffic assignment procedure can effectively reduce emission concentrations at those locations with the worst air quality conditions, with only a marginal increase in travel time and average emission concentration in the network.
SYNTHESIS OF AROMATIC ALDEHYDES BY LACCASE-MEDIATOR ASSISTED OXIDATION

Abstract Aromatic aldehydes can be prepared in aqueous medium by oxidation of the corresponding methyl aromatic compounds in the presence of oxygen, the enzyme laccase and catalytic amounts of various N-hydroxy compounds. Allylic alcohols also gave the corresponding aldehydes in good yield. Competing reactions reveal that the N-hydroxy compounds is involved in the rate determining step of the reaction.
A gateway placement algorithm in wireless mesh networks

An innovative gateway placement scheme is proposed for wireless mesh networks (WMNs) in this paper. In the WMN model, a regular grid backbone network comprising of mesh routers overlays on an ad hoc network comprising of mesh clients; a certain amount of gateways is chosen among mesh routers to provide Internet access. Thus, given the number of gateways, the proposed gateway placement scheme provides a framework of maximizing the throughput of WMNs through proper placement of these gateways. The location of a gateway is determined based on a new performance metric called multi-hop traffic-flow weight (MTW). The MTW computation takes into account many factors that impact the throughput of WMNs, i.e., the number of mesh routers, the number of mesh clients, the number of gateways, traffic demand from mesh clients, locations of gateways, and possible interference among gateways. The performance of the proposed gateway placement scheme is evaluated through simulations. Experimental results show that it constantly outperforms other schemes with a large margin.
Organic Synthesis in the Age of Computers

The computer affords four areas of interest to synthetic chemists: (1) storage and retrieval of information; (2) complex calculations of shape and reaction dynamics; (3) artificial intelligence (AI) to solve synthetic and analytical problems; (4) overall direction of multiple laboratory experiments. Our work began 30 years ago initiating molecular geometry calculations to match experimental results. The explosive growth of computer power since will be illustrated. Synthesis design (as AI) requires an efficient protocol to search huge trees. The SYNGEN program is based on simplification and systematization, first of skeletal dissection, then of structure and reaction characterization, for generation of optimal synthesis routes. The program will be be described and its future development outlined. Finally, a perspective on the future of all four areas will be sketched, noting the necessary attendant growth in systematic use by chemists and in sympathetic interfaces by software designers.
Measurements of the Diffuse Ultraviolet Background and the Terrestrial Airglow with the Space Telescope Imaging Spectrograph

Far-UV observations in and near the Hubble Deep Fields demonstrate that the Space Telescope Imaging Spectrograph (STIS) may obtain unique and precise measurements of the diffuse far-ultraviolet background. Although STIS is not the ideal instrument for such measurements, high-resolution images allow Galactic and extragalactic objects to be masked to very faint magnitudes, thus ensuring a measurement of the truly diffuse UV signal. The programs we have analyzed were not designed for this scientific purpose, but they would be sufficient to obtain a very sensitive measurement if it were not for a weak but larger than expected signal from airglow in the STIS 1450?1900 ? bandpass. Our analysis shows that STIS far-UV crystal quartz observations taken near the limb during orbital day can detect a faint airglow signal, most likely from N I ?1493, that is comparable to the dark rate and inseparable from the far-UV background. Discarding all but the night data from these data sets yields the diffuse far-ultraviolet background measurement 501 ? 103 photons cm-2 s-1 sr-1 ?-1, along a line of sight with very low Galactic neutral hydrogen column (NH I = 1.5 ? 1020 cm-2) and extinction [E(B-V) = 0.01 mag]. This result is in good agreement with earlier measurements of the far-UV background and should not include any significant contribution from airglow. We present our findings as a warning to other groups who may use the STIS far-UV camera to observe faint extended targets and to demonstrate how this measurement may be properly obtained with STIS.
Effects of Canopy-Payload Relative Motion on Control of Autonomous Parafoils

An eight-degree-of-freedom model is developed that accurately models relative pitching and yawing motion of a payload with respect to a parafoil. Constraint forces and moments are found analytically rather than using artificial constraint stabilization. A turn rate controller common in precision placement algorithms is used to demonstrate that relative yawing motion of the payload can result in persistent oscillations of the system. A model neglecting relative payload yawing failed to predict the same oscillations. It is shown that persistent oscillations can be eliminated by reduction of feedback gains; however, resulting tracking performance is poor. A reduced-order linear model is shown to be able to adequately predict relative payload dynamics for the proposed turn rate controller on the full eight-degree-of-freedom system.
Synthesis and Characterization of 4′-Amino and 4′-Nitro Derivatives of 4-N,N-Dimethylaminotriphenylmethane as Precursors for a Proximate Malachite Green Metabolite

Abstract This paper describes the preparation of 4′-amino ( 2 ) and 4′-nitro ( 3 ) derivatives of 4- N , N -dimethylaminotriphenylmethane as precursors for presumed DNA-binding metabolites of malachite green. The primary amine 2 was synthesized via a condensation of 4-lithiated bis-( N , N -trimethylsilyl)aniline and 4-(dimethylamino)benzophenone. A simple nitro-dediazoniation reaction of 2 failed to afford 3 , but gave exclusively a mixture derived from hydro-dediazoniation followed by nitration and N -dealkylative- N -nitrosation. Direct nitration of N , N -dimethylaminotriphenylmethane, however, afforded 3 as well as other nitro isomers.
Can Gravitational Instability Form Planetesimals

Abstract Gravitational instability of a particle layer in the solar nebula is inhibited by effects of the nebular gas. Particles must grow to at least meter size in order to decouple from shear-generated turbulence and allow the layer to reach critical density. The radial velocity dispersion induced by drag further delays onset of instability until the mean size is ∼10-100 m. This velocity dispersion, with the lack of damping in a layer of bodies this size, prevents instabilities of scales that could collapse to solid planetesimals. Collisional coagulation is the dominant growth mechanism for bodies of all sizes.
On Titanium Carbide Nanoparticles as the Origin of the 21 Micron Emission Feature in Post-asymptotic Giant Branch Stars

Titanium carbide (TiC) nanocrystals were recently proposed as the carrier of the mysterious 21 μm emission feature observed in post-asymptotic giant branch stars, based on their close spectral match and the presolar nature of meteoritic TiC nanograins (which reveals their stellar ejecta origin). But we show in this Letter that the Kramers-Kronig dispersion relations, which relate the wavelength-integrated extinction cross section to the total dust mass, would impose a lower bound on the TiC mass. This Kramers-Kronig lower limit exceeds the maximum available TiC mass by a factor of at least ~50, independent of the absolute value of the (unknown) ultraviolet/visible absorptivity of nano-TiC. The TiC model is therefore readily ruled out by the Kramers-Kronig physical principle.
A Procedure for Determining the Nature of Mercury's Core

We review the assertion that the precise measurement of the second degree gravitational harmonic coefficients, the obliquity, and the amplitude of the physical libration in longitude, C20, C22, θ, and Φ, for Mercury are sufficient to determine whether or not Mercury has a molten core. The conditions for detecting the signature of the molten core are that such a core not follow the 88-day physical libration of the mantle induced by periodic solar torques, but that it does follow the 250,000-year precession of the spin axis that tracks the orbit precession within a Cassini spin state. These conditions are easily satisfied if the coupling between the liquid core and solid mantle is viscous in nature. The alternative coupling mechanisms of pressure forces on irregularities in the core-mantle boundary (CMB), gravitational torques between an axially asymmetric mantle and an assumed axially asymmetric solid inner core, and magnetic coupling between the conducting molten core and a conducting layer in the mantle at the CMB are shown for a reasonable range of assumptions not to frustrate the first condition while making the second condition more secure. Simulations have shown that the combination of spacecraft tracking and laser altimetry during the planned MESSENGER orbiter mission to Mercury will determine C20, C22, and theta to better than 1% and Φ to better than 8%-sufficient precision to distinguish a molten core and constrain its size. The possible determination of the latter two parameters to 1% or less with Earth-based radar experiments and MESSENGER determination of C20 and C22 to 0.1% would lead to a maximum uncertainty in the ratio of the moment of inertia of the mantle to that of the whole planet, Cm/C, of ~2% with comparable precision in characterizing the extent of the molten core.
Anthropogenic renourishment feedback on shorebirds: A multispecies Bayesian perspective

Abstract In this paper, the realized niche of the Snowy Plover (Charadrius alexandrinus), a primarily resident Florida shorebird, is described as a function of the scenopoetic and bionomic variables at the nest-, landscape-, and regional-scale. We identified some possible geomorphological controls that influence nest-site selection and survival using data collected along the Florida Gulf coast. In particular, we focused on the effects of beach replenishment interventions on the Snowy Plover (SP), and on the migratory Piping Plover (PP) (Charadrius melodus) and Red Knot (RK) (Calidris canutus). Additionally, we investigated the potential differences between the SP breeding and wintering distributions using only regional-scale physiognomic variables and the recorded occurrences. To quantify the relationship between past renourishment projects and shorebird species we used a Monte Carlo procedure to sample from the posterior distribution of the binomial probabilities that a region is not a nesting or a wintering ground conditional on the occurrence of a beach replenishment intervention in the same and the previous year. The results indicate that it was 2.3, 3.1, and 0.8 times more likely that a region was not a wintering ground following a year with a renourishment intervention for the SP, PP and RK respectively. For the SP it was 2.5. times more likely that a region was not a breeding ground after a renourishment event. Through a maximum entropy principle model we observed small differences in the habitat use of the SP during the breeding and the wintering season. However, the habitats where RK was observed appeared quite different. While ecological niche models at the macro-scale are useful for determining habitat suitability ranges, the characterization of the species’ local niche is fundamentally important for adopting concrete multispecies management scenarios. Maintaining and creating optimal suitable habitats for SP characterized by sparse low vegetation in the foredunes areas, and uneven/low-slope beach surfaces, is the proposed conservation scenario to convert anthropic beach restorations and SP populations into a positive feedback without impacting other threatened shorebird species.
Computation of high Reynolds number internal/external flows

A general, user oriented computer program, called VNAF2, developed to calculate high Reynolds number internal/external flows is described. The program solves the two dimensional, time dependent Navier-Stokes equations. Turbulence is modeled with either a mixing length, a one transport equation, or a two transport equation model. Interior grid points are computed using the explicit MacCormack scheme with special procedures to speed up the calculation in the fine grid. All boundary conditions are calculated using a reference plane characteristic scheme with the viscous terms treated as source terms. Several internal, external, and internal/external flow calculations are presented.