cssi/SciSciGPT-SciSciNet huggingface dataset:
UNIDENTIFIED FEATURES IN THE ULTRAVIOLET SPECTRUM OF X Per

High-resolution ultraviolet spectra from the Space Telescope Imaging Spectrograph (STIS) were used to search for unidentified interstellar absorption features in the well studied sight line toward X Per (HD 24534). The significance of features detected was determined from Gaussian fits to the data, as well as the features' persistence in multiple observations. Fixed pattern noise characteristics were studied in STIS echelle data to distinguish between interstellar and instrumental features. We report the detection of two unidentified features that stand out from the more common fixed pattern noise features. Both features have depths of >3% of the continuum level making them very likely of interstellar origin. Lastly, we comment on possible carriers, and discuss future prospects for studying these and perhaps other unidentified lines in larger samples of sight lines.
Maze hypothesis development in assessing robot performance during teleoperation

National Institute of Standards and Technology (NIST) personnel had the opportunity to assess 14 prospective Urban Search and Rescue (USAR) robots, for the purposes of developing performance standards which currently do not exist. During this exercise, a maze configuration -- hypothesized as potentially valid test methodology -- was assessed. Among the findings, resultant significant differences in completion and decision making times facilitated classifying platforms based on performance. Also revealed was that errors in navigation and encounters with walls correlated with times taken in making decisions... the longer it took to make a decision, the greater the chance this decision was incorrect. Results validated the hypothesis of a maze as beneficial in eliciting data necessary for human controlled robot performance assessment.
Synthesis of phenylurethans of 1,2-dialkyl-4-pyrazolidinols as anticonvulsant agents

Twelve phenylurethans of 1,2-dialkyl-4-pyrazolidinols were synthesized and tested for anticonvulsant activity. Several compounds exhibited activity.
Strong and uniform equivalence of nonmonotonic theories: an algebraic approach

We show that the concepts of strong and uniform equivalence of logic programs can be generalized to an abstract algebraic setting of operators on complete lattices. Our results imply characterizations of strong and uniform equivalence for several nonmonotonic logics including logic programming with aggregates, default logic and a version of autoepistemic logic.
Transport in a spin-polarized Luttinger liquid in the presence of a single impurity

Abstract The conductance for a single impurity in a one-dimensional gas with electron–electron interaction and Zeeman splitting v F ↑ − v F ↓ = Δ ≠ 0 is considered. The presence of the Zeeman splitting gives rise to a non-diagonal bosonic model for the densities and canonical momenta conjugated to the densities. As a result the bosonic Hamiltonian cannot be diagonalized by a simple unitary transformation. To deal with the problem, we transform our model into the Lagrangian formalism. We find that for an extended Hubbard model controlled by the nearest neighbor interaction with a strength V gives rise to a term ρ ↑ R ρ ↑ L + ρ ↓ R ρ ↓ L . As a result, two Luttinger liquids for spin-up and spin-down electrons are obtained. We find the conductances for spin-up G ↑ and spin-down G ↓ are not equal. The anisotropy in the conductances G ↑ ≠ G ↓ gives rise to a spin-polarized wire.
Tensor products of $A_\infty $-algebras with homotopy inner products

We show that the tensor product of two cyclic $A_\infty$-algebras is, in general, not a cyclic $A_\infty$-algebra, but an $A_\infty$-algebra with homotopy inner product. More precisely, we construct an explicit combinatorial diagonal on the pairahedra, which are contractible polytopes controlling the combinatorial structure of an $A_\infty$-algebra with homotopy inner products, and use it to define a categorically closed tensor product. A cyclic $A_\infty$-algebra can be thought of as an $A_\infty$-algebra with homotopy inner products whose higher inner products are trivial. However, the higher inner products on the tensor product of cyclic $A_\infty$-algebras are not necessarily trivial.
Integrated AlGaInAs-silicon evanescent racetrack laser and photodetector

Recently, AlGaInAs-silicon evanescent lasers have been demonstrated as a method of integrating active photonic devices on a silicon based platform. This hybrid waveguide architecture consists of III-V quantum wells bonded to silicon waveguides. The self aligned optical mode leads to a bonding process that is manufacturable in high volumes. Here give an overview of a racetrack resonator laser integrated with two photo-detectors on the hybrid AlGaInAs-silicon evanescent device platform. Unlike previous demonstrations of hybrid AlGaInAs-silicon evanescent lasers, we demonstrate an on-chip racetrack resonator laser that does not rely on facet polishing and dicing in order to define the laser cavity. The laser runs continuous-wave (c.w.) at 1590 nm with a threshold of 175 mA, has a maximum total output power of 29 mW and a maximum operating temperature of 60 C. The output of this laser light is directly coupled into a pair of on chip hybrid AlGaInAs-silicon evanescent photodetectors used to measure the laser output.
An iterative action minimizing method for computing optimal paths in stochastic dynamical systems

Abstract We present a numerical method for computing optimal transition pathways and transition rates in systems of stochastic differential equations (SDEs). In particular, we compute the most probable transition path of stochastic equations by minimizing the effective action in a corresponding deterministic Hamiltonian system. The numerical method presented here involves using an iterative scheme for solving a two-point boundary value problem for the Hamiltonian system. We validate our method by applying it to both continuous stochastic systems, such as nonlinear oscillators governed by the Duffing equation, and finite discrete systems, such as epidemic problems, which are governed by a set of master equations. Furthermore, we demonstrate that this method is capable of dealing with stochastic systems of delay differential equations.
TRANSITS OF EARTH-LIKE PLANETS

Transmission spectroscopy of Earth-like exoplanets is a potential tool for habitability screening. Transiting planets are present-day "Rosetta Stones" for understanding extrasolar planets because they offer the possibility to characterize giant planet atmospheres and should provide an access to biomarkers in the atmospheres of Earth-like exoplanets, once they are detected. Using the Earth itself as a proxy we show the potential and limits of the transiting technique to detect biomarkers on an Earth-analog exoplanet in transit. We quantify the Earth's cross section as a function of wavelength, and show the effect of each atmospheric species, aerosol, and Rayleigh scattering. Clouds do not significantly affect this picture because the opacity of the lower atmosphere from aerosol and Rayleigh losses dominates over cloud losses. We calculate the optimum signal-to-noise ratio for spectral features in the primary eclipse spectrum of an Earth-like exoplanet around a Sun-like star and also M stars, for a 6.5 m telescope in space. We find that the signal-to-noise values for all important spectral features are on the order of unity or less per transit—except for the closest stars—making it difficult to detect such features in one single transit, and implying that coadding of many transits will be essential.
Divergence instability of reinforced composite circular cylindrical shells

Abstract Divergence instability of a simply supported orthotropic composite shell reinforced in both axial and circumferential directions is considered. The shell is subject to an axial static load and to the action of an external supersonic gas flow in the direction parallel to the shell axis. Two variants of the solution considered in the paper include discrete widely spaced stiffeners and closely spaced stiffeners; the latter case can be treated using a smeared stiffeners technique.
Credit Counseling and Mortgage Termination by Low-Income Households

Published research on credit counseling and mortgage termination is surprisingly scarce, despite substantial growth in this industry. While the purpose of counseling is to assist low-income borrowers to improve their handling of debt and thereby reduce default, counseling may also improve the borrowers’ understanding of their financial position and thus induce optimal mortgage termination. Using a competing-risks framework, we study the effects on default and prepayment of a counseling program implemented in several Midwest states. We find weak evidence of that the default hazard was lower for graduates of the counseling program, but that their default behavior was more optimal. The prepayment hazard was higher for counseled borrowers, but their prepayment behavior was not more optimal. Overall, counseling seems to affect the lenders’ profits, but the net effect should be evaluated both in terms of prepayment and default.
BULK BAND GAPS IN DIVALENT HEXABORIDES: A SOFT X-RAY EMISSION STUDY

Boron K-edge soft X-ray emission and absorption are used to address the fundamental question of whether divalent hexaborides are intrinsic semimetals or defect-doped band gap insulators. These bulk-sensitive measurements, complementary and consistent with surface-sensitive angle-resolved photoemission experiments, confirm the existence of a bulk band gap and the location of the chemical potential at the bottom of the conduction band.
Methyl (2E,4Z,6Z)-Deca-2,4,6-trienoate, a Thermally Unstable, Sex-Specific Compound from the Stink Bug Thyanta pallidovirens

Abstract Sexually mature male stink bugs, Thyanta pallidovirens , release a male-specific blend of volatiles, including several sesquiterpene hydrocarbons, and the highly conjugated ester methyl (2 E ,4 Z ,6 Z )-deca-2,4,6-trienoate 1 . The latter compound was synthesized, and found to rearrange under GC conditions via a 1,7 sigmatropic rearrangement. © 1997 Elsevier Science Ltd.
Synthesis of (3R)-carboxy pyrrolidine (a β-proline analogue) and its oligomer

Abstract A decamer of a β-amino acid analogue of l -proline, (3R)-carboxy pyrrolidine (β-proline), was synthesized from a readily available (R)-glycidol. It was found to possess a rigid secondary structure, as evidenced by its CD spectrum. The β-proline decamer, however, failed to bind to profilin, whereas the corresponding α- l -proline decamer bound tightly to this protein.
A ROBUST MEASURE OF TIDAL CIRCULARIZATION IN COEVAL BINARY POPULATIONS: THE SOLAR-TYPE SPECTROSCOPIC BINARY POPULATION IN THE OPEN CLUSTER M35

We present a new homogeneous sample of 32 spectroscopic binary orbits in the young (~150 Myr) main-sequence open cluster M35. The distribution of orbital eccentricity versus orbital period (e- log P) displays a distinct transition from eccentric to circular orbits at an orbital period of ~10 days. The transition is due to tidal circularization of the closest binaries. The population of binary orbits in M35 provide a significantly improved constraint on the rate of tidal circularization at an age of 150 Myr. We propose a new and more robust diagnostic of the degree of tidal circularization in a binary population based on a functional fit to the e- log P distribution. We call this new measure the tidal circularization period. The tidal circularization period of a binary population represents the orbital period at which a binary orbit with the most frequent initial orbital eccentricity circularizes (defined as e = 0.01) at the age of the population. We determine the tidal circularization period for M35, as well as for seven additional binary populations spanning ages from the pre-main sequence (~3 Myr) to the late main sequence (~10 Gyr), and use Monte Carlo error analysis to determine the uncertainties on the derived circularization periods. We conclude that current theories of tidal circularization cannot account for the distribution of tidal circularization periods with population age.
A highly active and magnetically retrievable nanoferrite–DOPA–copper catalyst for the coupling of thiophenols with aryl halides

Diaryl sulfides were synthesized using a magnetically recoverable heterogeneous Cu catalyst via one-pot multi component reaction using MW irradiation; the use of isopropanol as a benign reaction medium, easy recovery of the catalyst using an external magnet, efficient recycling, and the high stability of the catalyst render the protocol economic and sustainable.
c < 1 string from two dimensional black holes

We study a topological string description of the c < 1 non-critical string whose matter part is defined by the time-like linear dilaton CFT. We show that the topologically twisted N=2 SL(2,R)/U(1) model (or supersymmetric 2D black hole) is equivalent to the c < 1 non-critical string compactified at a specific radius by comparing their physical spectra and correlation functions. We examine another equivalent description in the topological Landau-Ginzburg model and check that it reproduces the same scattering amplitudes. We also discuss its matrix model dual description.
PRECISION MEASUREMENT BASED ON ULTRACOLD ATOMS AND COLD MOLECULES

Ultracold atoms and molecules provide ideal stages for precision tests of fundamental physics. With microkelvin neutral strontium atoms confined in an optical lattice, we have achieved a fractional resolution of 4 × 10-15 on the 1S0–3P0 doubly forbidden 87Sr clock transition at 698 nm. Measurements of the clock line shifts as a function of experimental parameters indicate systematic errors below the 10-15 level. The ultrahigh spectral resolution permits resolving the nuclear spin states of the clock transition at small magnetic fields, leading to measurements of the 3P0 magnetic moment and metastable lifetime. In addition, photoassociation spectroscopy performed on the narrow 1S0–3P1 transition of 88Sr shows promise for efficient optical tuning of the ground state scattering length and production of ultracold ground state molecules. Lattice-confined Sr2 molecules are suitable for constraining the time variation of the proton–electron mass ratio. In a separate experiment, cold, stable, ground state polar molecules are produced from Stark decelerators. These cold samples have enabled an order-of-magnitude improvement in the measurement precision of ground state, Λ doublet microwave transitions in the OH molecule. Comparing the laboratory results to those from OH megamasers in interstellar space will allow a sensitivity of 10-6 for measuring the potential time variation of the fundamental fine structure constant Δα/α over 1010 years. These results have also led to improved understandings of the molecular structure. The study of the low magnetic field behavior of OH in its 2Π3/2 ro-vibronic ground state precisely determines a differential Lande g factor between opposite parity components of the Λ doublet.
A note on D-spaces☆

We introduce notions of nearly good relations and N-sticky modulo a relation as tools for proving that spaces are D-spaces. As a corollary to general results about such relations, we show that Cp(X) is hereditarily a D-space whenever X is a Lindelof Σ-space. This answers a question of Matveev, and improves a result of Buzyakova, who proved the same result for X compact. We also prove that if a space X is the union of finitely many D-spaces, and has countable extent, then X is linearly Lindelof. It follows that if X is in addition countably compact, then X must be compact. We also show that Corson compact spaces are hereditarily D-spaces. These last two results answer recent questions of Arhangel'skii. Finally, we answer a question of van Douwen by showing that a perfectly normal collectionwise-normal non-paracompact space constructed by R. Pol is a D-space.
Differentiation of receptor systems activated by sympathomimetic amines.

CLASSIFICATION of receptor systems which are activated by sympathomimetic amines has engaged the attention of many investigators. Ahlquist1–3 has suggested the convenient designations of alpha (α) and beta (β) to distinguish major differences in the responses elicited in various organ systems. Our investigations have provided results which cannot be explained easily on the assumption that the β-type designates a single receptor population4–6. We now report additional studies which show that two distinct receptor types are at present included within this group.
An elective course on current concepts in adult ambulatory care.

Objective. To design and evaluate a doctor of pharmacy course exploring disease states commonly encountered in ambulatory care, while applying literature to clinical practice and promoting a continual learning mindset. Design. This elective incorporated a learner-centered teaching approach. Each week, 2 groups of students were assigned a clinical trial to present to their peers. The focus was on clinical application and impact, rather than literature evaluation. A social networking group on Facebook was used to expose students to pharmacy information outside the classroom. Assessment. Student grades were determined by multiple activities: presentations, participation and moderation of the Facebook group, class participation, quiz scores, and quiz question development. Course evaluations served as a qualitative assessment of student learning and perceptions, quizzes were the most objective assessment of student learning, and presentation evaluations were the most directed assessment of course goals. Conclusion. This elective was an innovative approach to teaching ambulatory care that effectively filled a curricular void. Successful attainment of the primary course goals and objectives was demonstrated through course evaluations, surveys, and quiz and presentation scores.
Scattering Theory for Dissipative Hyperbolic Systems

An abstract theory of scattering is developed for dissipative hyperbolic systems, a typical example of which is the wave equation: utt = Δu in an exterior domain with lossy boundary conditions: un ∓ αut = 0, α ≥ 0. In this theory, as in an earlier theory developed by the authors for conservative systems, a central role is played by two distinguished subspaces of data common to both the perturbed and unperturbed problems. Associated with each sub-space is a translation representation of the unperturbed system. When these representations coincide they provide a convenient tool for extending the data so as to include a large class of generalized eigenfunctions for both the perturbed and unperturbed generators. The scattering matrix is characterized in terms of these generalized eigenfunctions; it is shown to be meromorphic in the whole complex plane and holomorphic in the lower half plane. The zeros and poles of the scattering matrix correspond, respectively, to incoming and outgoing generalized eigenfunctions of the perturbed generator.
Spectra and symmetric spectra in general model categories

Abstract We give two general constructions for the passage from unstable to stable homotopy that apply to the known example of topological spaces, but also to new situations, such as the A 1 -homotopy theory of Morel and Voevodsky (preprint, 1998) and Voevodsky (Proceedings of the International Congress of Mathematicians, Vol. I, Berlin, Doc. Math. Extra Vol. I, 1998, pp. 579–604 (electronic)). One is based on the standard notion of spectra originated by Vogt (Boardman's Stable Homotopy Category, Lecture Notes Series, Vol. 21, Matematisk Institut Aarhus Universitet, Aarhus, 1970). Its input is a well-behaved model category D and an endofunctor T, generalizing the suspension. Its output is a model category Sp N ( D ,T) on which T is a Quillen equivalence. The second construction is based on symmetric spectra (Hovey et al., J. Amer. Math. Soc. 13(1) (2000) 149–208) and applies to model categories C with a compatible monoidal structure. In this case, the functor T must be given by tensoring with a cofibrant object K. The output is again a model category Sp Σ ( C ,K) where tensoring with K is a Quillen equivalence, but now Sp Σ ( C ,K) is again a monoidal model category. We study general properties of these stabilizations; most importantly, we give a sufficient condition for these two stabilizations to be equivalent that applies both in the known case of topological spaces and in the case of A 1 -homotopy theory.
A local Langevin equation for slow long-distance modes of hot non-Abelian gauge fields

Abstract The effective theory for the dynamics of hot non-Abelian gauge fields with spatial momenta of order of the magnetic screening scale g 2 T is described by a Boltzmann equation. The dynamical content of this theory is explored. There are three relevant frequency scales, gT , g 2 T and g 4 T , associated with plasmon oscillations, multipole fluctuations of the charged particle distribution, and with the nonperturbative gauge field dynamics, respectively. The frequency scale gT is integrated out. The result is a local Langevin-type equation. It is valid to leading order in g and to all orders in log(1/ g ), and it does not suffer from the hard thermal loop divergences of classical thermal Yang–Mills theory. We then derive the corresponding Fokker–Planck equation, which is shown to generate an equilibrium distribution corresponding to 3-dimensional Yang–Mills theory plus a Gaussian free field.
Experimental guidance to the template of neutrino mass

Abstract There are now several experimental indications that neutrinos, which are massless in the standard model, may indeed possess mass. These observations can be fit into two possible patterns, both with a light ν e . One has a light ν μ to accommodate and MSW solution to the solar neutrino deficit (SνD), and a heavier ν τ which might either be an important component of dark matter, or possibly account for the atmospheric deficit of ν μ 's (AνD). The other pattern has a ν μ and a ν τ near 17 keV (with ν μ → ν τ giving the AνD) and a light sterile neutrino, ν s (for a ν e → ν s explanation of the SνD). In the latter case the ν e and ν s c ould contribute importantly to, but not be the dominant component of, dark matter. These two neutrino mass possibilities can be tested soon, providing a rigid template to which any more comprehensive theory must conform.
Statistical Properties of Quantum Graph Spectra

A general analytical approach to the statistical description of quantum graph spectra based on the exact periodic orbit expansions of quantum levels is discussed. The exact and approximate expressions obtained in [5] for the probability distribution functions using the spectral hierarchy method are analyzed. In addition, the mechanism of appearance of the universal statistical properties of spectral fluctuations of quantum-chaotic systems is considered in terms of the semiclassical theory of periodic orbits.
Should Asians demand both entrepreneurship and human rights

Abstract Local entrepreneurs, essential for creation of sustainable broad-based wealth, can provide countervailing power against local human rights violators. Our statistically testable hypothesis is that joint advocacy by promoters of entrepreneurship on the right side of the political spectrum and human rights advocates on the left side will not be at cross-purposes. Analysis of eight variables dealing with governance, corruption, entrepreneurship activity, human rights, capital markets and economic freedom finds significant correlations between left and right side variables. Since the left and the right can agree on 40 out of 50 economic freedom items, Asians should demand both, even in China.
Partial purification and characterization of a nerve growth factor-sensitive kinase and its substrate from PC12 cells

The cell-free, nerve growth factor-sensitive incorporation of radioactive phosphate into a 100,000-dalton protein (Nsp100), observed in a previous study (End,D., Tolson, N., Hashimoto, S., and Guroff, G. (1983) J. Biol. Chem. 258, 6549-6555), has been characterized and the system fractionated. It is shown here that the decrease in incorporation due to treatment of the cells with nerve growth factor is transient, even in the continued presence of nerve growth factor. The decrease in radioactive phosphate incorporation is due to an inhibition of phosphorylation, not to a stimulation of a dephosphorylation. Evidence is presented to suggest that no soluble cofactors are needed for the phosphorylation and no soluble second messengers are responsible for the inhibition. It is demonstrated that the phosphorylation requires divalent cations; both Mg2+ and Mn2+ are effective in this regard. ATP is the preferred phosphate donor, the phosphorylation is maximal at pH values between 5 and 6, and Na+, K+, and Zn2+ are rather specific inhibitors. The system has been partially purified and the resolved components have been used to show that the kinase and the substrate are separate molecules, that the kinase, not the substrate, is the heat-labile portion, and that the kinase has a molecular weight of 110,000-130,000. Finally, evidence is presented to indicate that the kinase, not the substrate, is the component responsible for the decrease in phosphorylation seen after treatment of the cells with nerve growth factor.
Renal Cell Carcinoma Metastatic to the Thumb: A Case Report and Review of Subungual Metastases From All Primary Sites

Subungual metastatic cancer from any primary site is rare. Only seven cases from primary renal cell carcinoma have previously been reported. We now describe a further example of this condition and review its clinical features, radiographic findings and pathological changes. The diagnosis of subungual metastasis should be considered in any patient with metastatic cancer who develops a new lesion of the distal phalanx.
Truncated determinant approach to light dynamical quarks

Abstract Virtual quark effects in lattice QCD are studied in an approach where the infrared modes are included in a precise and gauge-invariant manner. At fixed physical volume the required number of modes does not increase in the continuum limit, and the acceptance is tolerable even for very light quark masses. Topological charge distributions at varying quark mass, and the static quark potential, showing the onset of string-breaking, are presented in both QED2 and QCD4.
A link between reactivity and local structure in acid catalysis on zeolites.

The extent to which spatial constraints influence rates and pathways in catalysis depends on the structure of intermediates, transition states, and active sites involved. We aim to answer, as we seek insights into catalytic mechanisms and site requirements, persistent questions about the potential for controlling rates and selectivities by rational design of spatial constraints around active sites within inorganic structures useful as catalysts. This Account addresses these matters for the specific case of reactions on zeolites that contain Bronsted acid sites encapsulated within subnanometer channels. We compare and contrast here the effects of local zeolite structure on the dynamics of the carbonylation of surface methyl groups and of the isotopic exchange of CD4 with surface OH groups on zeolites. Methyl and hydroxyl groups are the smallest monovalent cations relevant in catalysis by zeolites. Their small size, taken together with their inability to desorb except via reactions with other species, allowed us to discriminate between stabilization of cationic transition states and stabilization of adsorbed reactants and products by spatial constraints. We show that apparent effects of proton density and of zeolite channel structure on dimethyl ether carbonylation turnover rates reflect instead the remarkable specificity of eight-membered ring zeolite channels in accelerating kinetically relevant steps that form *COCH3 species via CO insertion into methyl groups. This specificity reflects the selective stabilization of cationic transition states via interactions with framework oxygen anions. These findings for carbonylation catalysts contrast sharply the weak effects of channel structure on the rate of exchange of CD4 with OH groups. This latter reaction involves concerted symmetric transition states with much lower charge than that required for CH3 carbonylation. Our Account extends the scope of shape selectivity concepts beyond those reflecting size exclusion and preferential adsorption. Our ability to discriminate among various effects of spatial constraints depends critically on dissecting chemical conversions into elementary steps of kinetic relevance and on eliminating secondary reactions and accounting for the concomitant effects of zeolite structure on the stability of adsorbed reactants and intermediates.
Inflation from warped space

A long period of inflation can be triggered when the inflaton is held up on the top of a steep potential by the infrared end of a warped space. We first study the field theory description of such a model. We then embed it in the flux stabilized string compactification. Some special effects in the throat reheating process by relativistic branes are discussed. We put all these ingredients into a multi-throat brane inflationary scenario. The resulting cosmic string tension and a multi-throat slow-roll model are also discussed.
Stomahesive as a tracheostomy dressing

Seven patients had occlusive stomahesive dressings placed on their tracheostomies. These patients were compared with four patients managed with standard tracheostomy care. Stomahesive was applied using a defined technique and all seven patients were followed until tracheostomy closure. The average duration of stomahesive care was 26 days and the dressings remained occlusive for an average of 4 days. Photographic evidence revealed that skin changes were less in patients treated with stomahesive dressings.
Propagation of a shock wave front across a curved fluid-solid interface

Abstract : Geometric optics, or the ray theory, is used to investigate the effect of pulse reflection and transmission at a curved fluid-solid interface. In particular, the problem of a plane pressure pulse, supported by an acoustic fluid, impinging on a plane symmetrical elastic body whose cross-section is delineated by circular arcs is considered. The response of the solid is determined along its center line to reflection at the back interface with another fluid. Consideration of the special case in which the fluid densities are zero indicates that special care must be exercised in dealing with the in vacuo problem, and particularly in specifying the boundary conditions in that instance. (Author)
Better Pseudorandom Generators from Milder Pseudorandom Restrictions

We present an iterative approach to constructing pseudorandom generators, based on the repeated application of mild pseudorandom restrictions. We use this template to construct pseudorandom generators for combinatorial rectangles and read-once CNFs and a hitting set generator for width-3 branching programs, all of which achieve near-optimal seed-length even in the low-error regime: We get seed-length $\tilde{O}(\log (n/\epsilon))$ for error $\epsilon$. Previously, only constructions with seed-length $O(\log^{3/2} n)$ or $O(\log^2 n)$ were known for these classes with error $\epsilon = 1/\poly(n)$. The (pseudo)random restrictions we use are milder than those typically used for proving circuit lower bounds in that we only set a constant fraction of the bits at a time. While such restrictions do not simplify the functions drastically, we show that they can be derandomized using small-bias spaces.
A facile synthesis of chiral ω-allyl- and ω-n-propyllactones via asymmetric allylboration of formyl esters with B-allyldiisopinocampheylborane

Abstract Asymmetric allylboration of aldehydes containing an adjacent ester group with B -allyldiisopinocampheylborane, followed by hydrolysis and cyclization, provides the corresponding allyl substituted lactones in high yields and ≥92% enantiomeric excess. Hydrogenation of these lactones provides the corresponding propyl substituted lactones without any loss of optical purity.
Topological entropy of free product automorphisms

Using free probability constructions involving Cuntz-Pimsner C*-algebras we show that the topological entropy of the free product of two automorphisms is equal to the maximum of the individual entropies. As applications we show that general free shifts have entropy zero. We show that any nuclear C*-dynamical system admits an entropy preserving covariant embedding into the Cuntz algebra on infinitely many generators. It follows that any simple nuclear purely infinite C*-algebra admits an automorphism with any given value of entropy. As a final application we show that if two automorphisms satisfy a CNT-variational principle then so does their free product.
Intramolecular azide-diene cycloadditions. An approach to fused bicyclic 3-pyrrolines based on a one-pot nitrene-diene cycloaddition equivalent.

Abstract Cyclization of heterosubstituted ω-azidodienes 11 provides fused bicyclic 3-pyrrolines 12 in one operation. These pyrrolines are potentially useful intermediates for natural products synthesis, as illustrated by further functionalization.
DISCOVERY OF A VERY LOW MASS TRIPLE WITH LATE-M AND T DWARF COMPONENTS: LP 704-48/SDSS J0006–0852AB*

We report the identification of the M9 dwarf SDSS J000649.16?085246.3 as a spectral binary and radial velocity (RV) variable with components straddling the hydrogen-burning mass limit. Low-resolution near-infrared spectroscopy reveals spectral features indicative of a T dwarf companion, and spectral template fitting yields component types of M8.5 ? 0.5 and T5 ? 1. High-resolution near-infrared spectroscopy with Keck/NIRSPEC reveals pronounced RV variations with a semi-amplitude of 8.2 ? 0.4?km?s?1. From these we determine an orbital period of 147.6 ? 1.5?days and eccentricity of 0.10 ? 0.07, making SDSS J0006?0852AB the third tightest very low mass binary known. This system is also found to have a common proper motion companion, the inactive M7 dwarf LP 704-48, at a projected separation of 820 ??120?AU. The lack of H? emission in both M dwarf components indicates that this system is relatively old, as confirmed by evolutionary model analysis of the tight binary. LP 704-48/SDSS J0006?0852AB is the lowest-mass confirmed triple identified to date, and one of only seven candidate and confirmed triples with total masses below 0.3 M ? currently known. We show that current star and brown dwarf formation models cannot produce triple systems like LP 704-48/SDSS J0006?0852AB, and we rule out Kozai-Lidov perturbations and tidal circularization as a viable mechanism to shrink the inner orbit. The similarities between this system and the recently uncovered low-mass eclipsing triples NLTT 41135AB/41136 and LHS 6343ABC suggest that substellar tertiaries may be common in wide M dwarf pairs.
Supergravity Solution of Intersecting Branes and AdS/CFT with Flavor

We construct the supergravity solution for fully localized D2/D6 intersection. The near horizon limit of this solution is the supergravity dual of supersymmetric Yang-Mills theory in 2+1 dimensions with flavor. We use this solution to formulate mirror symmetry of 2+1 dimensional gauge theories in the language of AdS/CFT correspondence. We also construct the supergravity dual of a non-commutative gauge theory with fundamental matter.
Land development and amenities: A predator-prey interaction

How land development in the form of land improvements and locational amenities interact in time, at any point in space characterized as a tourist area, is the topic of this rather brief investigation. The strong, non linear, interactive dynamics between the two entities is viewed in a general ecological predator-prey formulation, under a series of scenarios. Mildly cyclical and eventually unstable dynamics are portrayed under numerical simulation to be perhaps the most likely of the various scenarios explored. Windows of opportunity for governmental intervention are shown to exist, in the case where complex scale effects and significant externalities take place between the two. This paper presents an effective framework to fruitfully examine issues of sustainable development.
Why Do Programmers Earn More in Houston Than Hyderabad? Evidence from Randomized Processing of US Visas

Abstract Why do workers earn so much more in the United States than in India? This study compares the earnings of workers in the two countries in a unique setting. The product is perfectly tradable (software), technology differences are nil (they are members of the same work team), and the workers are identical in expectation (those who enter the United States are chosen by natural randomization). The results suggest that output tradability, technology, and human capital together explain much less than half of the earnings gap. Location itself may have large effects on individual workers' wages and productivity, for reasons poorly understood.
Singular perturbation equations for flexible satellites

Force equations of motion of the individual flexible elements of a satellite were obtained in a previous paper. Moment equations of motion of the composite bodies of a flexible satellite are to be developed using two sets of equations which form the basic system for any dynamic model of flexible satellites. This basic system consists of a set of N-coupled, nonlinear, ordinary, or partial differential equations, for a flexible satellite with n generalized, structural position coordinates. For single composite body satellites, N is equal to (n + 3); for dual-spin systems, N is equal to (n + 9). These equations involve time derivatives up to the second order. The study shows a method of avoiding this linearization by reducing the N equations to 3 or 9 nonlinear, coupled, first order, ordinary, differential equations involving only the angular velocities of the composite bodies. The solutions for these angular velocities lead to linear equations in the n generalized structural position coordinates, which can be solved by known methods.
ENDOGENOUS FORMATION OF COALITIONS

We develop a model of coalition formation based on personal proximities among the players of an n-person game. Several examples are worked out in detail, showing that certain coalitions are much more stable than others, and/or much more likely to form than others. We also consider the dynamics of such coalition-formation. By a numerical example, we show that small changes in the initial conditions can lead to very different results in the coalitions formed in a given game.
Pointless Hyperelliptic Curves

In this paper we consider the question of whether there exists a hyperelliptic curve of genus g which is defined over Fq but has no rational points over Fq for various pairs (g,q). As an example of such a result, we show that if p is a prime such that q=p−12 is also prime then there will be pointless hyperelliptic curves over Fp of every genus g⩾q−1.
A self-organized approach for detecting communities in networks

The community structure of networks reveals hidden information about the whole network structure that cannot be discerned using other topological properties. Yet, the importance of identifying community structure in networks to many fields such as medicine, social sciences and national security, calls for better approaches for performing the identification. The prevalent community detection algorithms utilize a centralized approach that is unlikely to scale to very large networks and does not handle dynamic networks. We propose a self-organized approach to community detection which utilizes a newly introduced concept of node entropy to allow individual nodes to make decentralized and independent decisions concerning the community to which they belong; we call our approach Self- O rganized C ommunity I dentification AL gorithm ( SOCIAL ). Node entropy is a mathematical expression of an individual node’s satisfaction with its current community. As nodes become more “satisfied”, i.e., entropy is low, the community structure of a network is emergent. Our algorithm offers several advantages over existing algorithms including near-linear performance, identification of partial community overlaps, and handling of dynamic changes in the network in a local manner.
On the ultimate complexity of factorials

It has long been observed that certain factorization algorithms provide a way to write the product of many different integers succinctly. In this paper, we study the problem of representing the product of all integers from 1 to n (i.e. n!) by straight-line programs. Formally, we say that a sequence of integers an is ultimately f(n)-computable, if there exists a nonzero integer sequence mn such that for any n, anmn can be computed by a straight-line program (using only additions, subtractions and multiplications) of length at most f(n). Shub and Smale [12] showed that if n! is ultimately hard to compute, then the algebraic version of NP ≠ P is true. Assuming a widely believed number theory conjecture concerning smooth numbers in a short interval, a subexponential upper bound (exp(c√log n log log n)) for the ultimate complexity of n! is proved in this paper, and a randomized subexponential algorithm constructing such a short straight-line program is presented as well.
Testing Two Nuclear Physics Approximations Used in the Standard Leaky-Box Model for the Spallogenic Production of LiBeB

The spallative production rates of lithium, beryllium, and boron (LiBeB) are a necessary component in any calculation of the evolution of these nuclei in the Galaxy. Previous calculations of these rates relied on two assumptions relating to the nuclear physics aspects: the straight-ahead approximation that describes the distribution of fragment energies and the assumption that the major contributor to the production rate arises from single-step reactions between primary cosmic-ray projectiles and interstellar medium targets. We examine both assumptions by using a semiempirical description for the spall's energy distribution and by including the reactions that proceed via intermediary fragments. After relaxing the straight-ahead approximation, we find that the changes in the production rates and emerging fluxes are small and do not warrant rejection of this approximation. In contrast, we discover that two-step reactions can alter the production rate considerably, leading to noticeable increases in the efficiency of producing the LiBeB nuclei. Motivated by this result, we introduce a cascade technique to compute the production rates exactly and find that the results differ only slightly from those of our two-step calculations. We thus conclude that terminating the reaction network at the two-step order is sufficiently accurate for current studies of spallation.
Correlation of meteoroid environments in the solar system.

Meteoroid masses cannot be inferred from the observed decelerations of meteors in the Earth's atmosphere. Moreover, the effects of solar electromagnetic radiation on the smaller meteoroids cannot be related to their mass alone. The name "mass concentration" and symbol C* are proposed for the pertinent property, essentially the mass per unit projected area, g cm~. The radiation pressure limit may be designated as C* = 10~ without reference to meteoroid density, porosity, or size. The name "meteoroid perforation capability" and symbol C are proposed for a similar property, directly measureable in space experiments, regardless of statistical variations in meteoroid density and velocity. Meteor observations, space experiments, and hypervelocity impact data are analyzed in terms of C* and C, and a log-normal form for the mean cumulative flux of meteoroids at 1 a.u. is derived. The influences of heliocentric longitude and of unknown meteoroid streams in the interplanetary environment are treated statistically for space missions to Venus and Mars.
High-Flux Hyperentangled Photon-Pairs from a Microstructure-Fiber Sagnac Interferometer

We generate hyperentangled (time-bin and polarization) photon-pairs using a microstructure-fiber Sagnac interferometer. Two-photon-interference visibilities in both degrees of freedom are >83%, and the Bell’s inequality is violated by 25 σ at a 1-kHz coincidence rate.
Chloride ion pairs in water

The study of ions in water by statistical mechanical methods has made a significant contribution to the authors understanding of solution chemistry and biological processes in saline solutions. Integral equation methods have been used recently by Pettitt and Rossky to study solvent-averaged forces and the effective interactions or the potentials of mean force (PMF) for the alkali halides in water at infinite dilution. In this communication, they report a quantitative study of the Cl/sup -/-Cl/sup -/ PMF in water with use of an umbrella sampling method and the same Hamiltonian as that used in the integral equation study. The system studied here consists of two chloride ions and 295 water molecules in a rectangular box with periodic boundary conditions and lengths of 25.4, 18.6, and 18.6 A in the x,y,z directions, respectively.
X-ray diffraction cell for Debye-Scherrer and Guinier (Huber) cameras at pressure and temperature

Abstract A gas high-pressure cell for X-ray diffraction studies was developed. It is capable of 2700 atm hydrogen pressure at ambient temperature, when used in a Debye-Scherrer camera, and 1020 atm to at least 300°C, when used in a Guinier (Huber) camera. It is suitable for weakly scattering materials.
The Critical Value of the Contact Process with Added and Removed Edges

We show that the critical value for the contact process on a vertex-transitive graph $$\mathcal{G}$$ with finitely many edges added and/or removed is the same as the critical value for the contact process on $$\mathcal{G}$$ . This gives a partial answer to a conjecture of Pemantle and Stacey.
Global Forces in Eruptive Solar Flares: The Lorentz Force Acting on the Solar Atmosphere and the Solar Interior

We compute the change in the Lorentz force integrated over the outer solar atmosphere implied by observed changes in vector magnetograms that occur during large, eruptive solar flares. This force perturbation should be balanced by an equal and opposite force perturbation acting on the solar photosphere and solar interior. The resulting expression for the estimated force change in the solar interior generalizes the earlier expression presented by Hudson, Fisher, and Welsch (Astron. Soc. Pac. CS-383, 221, 2008), providing horizontal as well as vertical force components, and provides a more accurate result for the vertical component of the perturbed force. We show that magnetic eruptions should result in the magnetic field at the photosphere becoming more horizontal, and hence should result in a downward (toward the solar interior) force change acting on the photosphere and solar interior, as recently argued from an analysis of magnetogram data by Wang and Liu (Astrophys. J. Lett. 716, L195, 2010). We suggest the existence of an observational relationship between the force change computed from changes in the vector magnetograms, the outward momentum carried by the ejecta from the flare, and the properties of the helioseismic disturbance driven by the downward force change. We use the impulse driven by the Lorentz-force change in the outer solar atmosphere to derive an upper limit to the mass of erupting plasma that can escape from the Sun. Finally, we compare the expected Lorentz-force change at the photosphere with simple estimates from flare-driven gasdynamic disturbances and from an estimate of the perturbed pressure from radiative backwarming of the photosphere in flaring conditions.