cssi/SciSciGPT-SciSciNet huggingface dataset:
Observations of V592 Cas -— an Outflow at Optical Wavelengths

We present new red optical spectra of V592 Cas aimed at exploring the properties of the outflow of this system in a spectral region where the underlying white dwarf and the accretion disk do not contribute significantly to the observed absorption components of the Hα and He I line profiles. We use the Hα emission line to study the wind, which appears as pronounced blueshifted P Cygni absorption troughs whose low velocity end contaminates the blue side of the emission line profile. The wind appears to be episodic in nature, with multiple events reaching velocities of 5000 km s^–1 in Hα. Similar (but weaker) wind signatures appear in the He I 5876 A line but are absent in He I 6678 A. Our data suggest that during wind episodes the wind is phase dependent and is visible for half of the orbit of the system. Considering that V592 Cas is viewed almost face-on, the symmetry axis of the outflow cannot be orthogonal to the disk and/or the outflow must have some other inherent asymmetry in outflow geometry. A possible origin of the wind is in a disk hotspot, either at the initial impact point of the accretion stream on the disk edge or as a result of disk overflow (similar to SW Sextantis stars). Simultaneous optical photometry during one night of our spectroscopic observations indicate that there is no clear relationship between the optical brightness variations and the strength of the outflow in this system.
Security, Privacy, Policy, and Dependability Roundup

IEEE Security a Privacy news briefs cover the latest in security, privacy, policy, and dependability.
Probing Polymer/Polymer Interfaces

Infrared-visible sum frequency generation spectroscopy (SFG) has been used to study the interface between poly(vinyl-N-octadecylcarbamate-co-vinyl acetate) (Comb) and deuterated or hydrogenated polystyrene (dPS or hPS) films. Strong methyl symmetric and Fermi resonance bands associated with the alkyl side chains of the Comb polymer are observed in the SFG spectra. In addition, for Comb/hPS spectra, symmetric and asymmetric vibration modes of phenyl groups are observed. The presence of asymmetric modes indicates the phenyl rings are tilted with respect to the interface normal.
Administration of LH-releasing hormone to selected subjects

Abstract Administration of highly purified porcine LH-releasing hormone (LRH) to 12 human beings caused a maximum mean increase in serum LH of 460 per cent. Lysine vasopressin, used as a control substance, had almost (10 per cent) no effect. The selected subjects were divided into several groups, so that specific aspects of the effects of LRH could be studied. Postmenopausal women were responsive to LRH regardless of whether or not their serum LH levels had been supressed by pretreatment with an oral contraceptive. Subcutaneous administration of LRH was at least as effective as the intravenous route of administration. Putrescine did not elevate serum FSH or LH levels and did not augment the response to LRH. This study demonstrates the effectiveness of LRH of porcine origin in releasing LH in the human being.
Decay modes of unstable strings in plane-wave string field theory

The cubic interaction vertex of light-cone string field theory in the plane-wave background has a simple effective form when considering states with only bosonic excitations. This simple effective interaction vertex is used in this paper to calculate the three string interaction matrix elements for states of arbitrary bosonic excitation and these results are used to examine certain decay modes on the mass-shell. It is shown that the matrix elements of one string to two string decays involving only bosonic excitations will vanish to all orders in 1/μ on the mass-shell when the number of excitations on the initial string is less than or equal to two, but in general will not vanish when the number of excitations is greater than two. Also, a truncated calculation of the mass-shell matrix elements for one string to three string decays of two excitation states is performed and suggests that these matrix elements do not vanish on the mass-shell. There is, however, a quantitative discrepancy between this last result and its (also non-vanishing) gauge theory prediction from the BMN correspondence.
Advanced Parental Age and the Risk of Autism Spectrum Disorder

Previous studies suggest that autism may be more common in the offspring of older parents. There is also a positive association between birth order, parental age, and autism, and a number of reports have shown firstborn children to be at increased risk. The aim of this prospective population-based cohort study was to determine whether advancing maternal and paternal ages were each independent risk factors for the development of autism spectrum disorder (ASD) in a large, population-based cohort of US children. Data were obtained from the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring Network, a group of 10 participating centers, which monitored 253,347 live births and had complete information from birth certificates on parental age, birth order, and other variables. The study group was comprised of 1251 children aged 8 years from this birth cohort who met the criteria for an ASD set forth in the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision. Following multivariable analysis to control for the other parent's age, birth order, and other covariables, maternal and paternal ages were each independently associated with autism: the adjusted odds ratio (aOR) for maternal age ≥35 versus 25 to 29 years was 1.3, with a 95% confidence interval (CI) of 1.1 to 1.6; the aOR for paternal age ≥40 years versus 25 to 29 years was 1.4, with a 95% CI of 1.1 to 1.8. There was a 3-fold greater likelihood of autism among firstborn offspring of 2 older parents compared to third- or later-born offspring of mothers aged 20 to 34 years and fathers aged <40 years (aOR, 3.1; 95% CI, 2.0-4.7). The investigators believe that this study is the most compelling evidence to date that the risk of ASD is associated with increases of both maternal and paternal age and decreases with birth order.
Effects of Unmixedness in Piloted-Lean Premixed Gas-Turbine Combustors

The characteristic time model (CTM) represents the dominant physical subprocesses related to combustor performance in terms of characteristic times. Properly formulated, these characteristic times account for variations in combustor geometry, fuel characteristics, and operating conditions. Here, a CTM for piloted–lean premixed combustor NOx emissions is used to investigate the sensitivity of NO formation in such combustors to fuel/air unmixedness and suggests an experimental method of evaluating premixed performance under fired conditions that is discussed in the companion paper.Copyright © 1997 by ASME
Absorption Spectra of Manganese and Silver in the Schumann Region

A method has been developed for observing absorption spectra of high melting point materials in the Schumann region. The absorption spectra of manganese and silver have been investigated in the region between $\ensuremath{\lambda}800\mathrm{A}$ and $\ensuremath{\lambda}1930\mathrm{A}$. Many new lines in MnI have been observed and it has been possible to link some of these with known levels in the Mn atom. A new sequence of terms, the ${d}^{9}\mathrm{snp}^{6}P^{0}$, has been found in AgI.
Flight, Wind Tunnel, and Numerical Experiments with a Slender Cone at Incidence

The three-dimensional leeward separation about a 5-deg semi-angle cone of 11 deg angle of incidence was Investigated in night, in the wind tunnel, and by numerical computations. The test conditions were Mach numbers of 0.6, 1.5, and 1.8 at Reynolds numbers between 7 and 10 million based on freestream conditions and a 76.2-cm (30-in.) length of surface. The surface pressure conditions measured included those of fluctuating and mean static, as well as recovery pressures generated by obstacle blocks to provide skin friction and separation-line locations. The mean static pressures from flight and wind tunnel were in reasonably good agreement. The computed results gave the same distributions, but were slightly more positive in magnitude. The experimentally measured primary and secondary separation line locations compared closely with computed results. There were substantial differences In level between the surface root-mean-square pressure fluctuations obtained in night and in the wind tunnel, due, It Is thought, to a relatively high acoustic disturbance level in the tunnel compared with the quiescent atmospheric conditions in night.
Lattice Supersymmetry via Twisting

We describe how the usual supercharges of extended supersymetry may be twisted to produce a BRST-like supercharge Q . The usual supersymmetry algebra is then replaced by a twisted algebra and the action of the twisted theory is shown to be generically Q -exact. In flat space the twisting procedure can be regared as a change of variables carrying no physical significance. However, the twisted theories can often be transferred to the lattice while preserving the twisted supersymmetry. As an example we construct a lattice version of the two-dimensional supersymmetry sigma model.
A generative CAI tutor for computer science concepts

Limited progress has been made in software for computer-assisted instruction. Frame-oriented CAI systems have dominated the field. These systems function as mechanized programmed texts and utilize the computational power of the computer to a minimal extent. In addition, they are difficult to modify and tend to provide a fairly fixed instructional sequence.
Development of a Theory-Based Assessment of Team Member Effectiveness

This article describes the development of the Comprehensive Assessment of Team Member Effectiveness. The authors used the teamwork literature to create potential items, which they tested using two surveys of college students (Ns = 2,777 and 1,157). The authors used exploratory factor analysis and confirmatory factor analysis to help them select items for the final instrument. The full instrument has 87 items that measure 29 types of team member contributions with 3 items each. These fall into five categories (contributing to the team's work; interacting with teammates; keeping the team on track; expecting quality; and having relevant knowledge, skills, and abilities). A short version of the instrument has 33 items. Potential uses for the instrument and suggestions for future research are discussed.
THE RELIGIOUS CONTEXT OF PREJUDICE

It is clear that these investigations, still in progress, tend to confirm demographic and sociological studies that we have also reviewed. Further, I believe they are compatible with our theological analysis, since it is clear that communal and extrinsic religion can draw strong support from the doctrines of revelation, election, and theocracy, which, as we have seen, provide the theological context of prejudice, so far as such exists. We can hope that this convergence of theological, sociological, and psychological analyses will lead to a further cooperation between behavioral and religious disciplines. We can also hope that our findings, when understood by clergy and laity, may lead to a decrease in bigotry and to an enhancement of charity in modern religious life. If I were asked what practical applications ensue from this analysis I would, of course, say that to reduce prejudice we need to enlarge the population of intrinsically religious people. There is no simple formula, for each personality is unique, and is stubbornly resistant to change. Yet precisely here lies the pastor's task, his opportunity, and his challenge.
Asset trading mechanisms and expansionary policy

Abstract Previous authors have argued that the otimal monetary policy is contractionary. If buyers value consumption substantially more than sellers, there is some randomness and informational constraints make asset trading useful, we show that there is an incentive compatible expansionary policy that dominates all incentive compatible contractionary policies.
Statistics of magnification perturbations by substructure in the cold dark matter cosmological model

We study the statistical properties of magnification perturbations by substructures in strong lensed systems using linear perturbation theory and an analytical substructure model including tidal truncation and a continuous substructure mass spectrum. We demonstrate that magnification perturbations are dominated by perturbers found within roughly a tidal radius of an image and that sizable magnification perturbations may arise from small, coherent contributions from several substructures within the lens halo. The rms fluctuation of the magnification perturbation is ~10%-20%, and both the average and rms perturbations are sensitive to the mass spectrum and density profile of the perturbers. Interestingly, we find that relative to a smooth model of the same mass, the average magnification in clumpy models is lower (higher) than that in smooth models for positive-parity (negative-parity) images. This is opposite from what is observed if one assumes that the image magnification predicted by the best-fit smooth model of a lens is a good proxy for what the observed magnification would have been if substructures were absent. While it is possible for this discrepancy to be resolved via nonlinear perturbers, we argue that a more likely explanation is that the assumption that the best-fit lens model is a good proxy for the magnification in the absence of substructure is not correct. We conclude that a better theoretical understanding of the predicted statistical properties of magnification perturbations by CDM substructure is needed in order to affirm that CDM substructures have been unambiguously detected.
Expanded Criteria Donor Kidney Allocation: Marked Decrease in Cold Ischemia and Delayed Graft Function at a Single Center

Expanded criteria donor (ECD) kidney allocation aims to increase utilization and facilitate placement. We implemented an ECD program for pre-consented candidates and studied whether ECD allocation decreased cold ischemia time and delayed graft function (DGF). We compared donor, recipient and transplant data for ECD transplants performed during the first year of our program to those performed in the preceding 5 1 years. Logistic regression identified risk factors for DGF. Of 356 candidates, 107 (30%) consented, 32 (9%) completed evaluation and 20 (6%) underwent ECD transplantation during the program’s first year. The recent and historical ECD cohorts had similar donor and recipient characteristics, except that recent ECD recipients were older. The rate of donor kidney biopsy dropped from 85% to 24% (p 4 HLA mismatches (OR 20.46; p = 0.0033) and cold ischemia time (OR 1.24/h; p = 0.0036). We conclude the ECD designation provides a description of kidney quality that may obviate biopsy. ECD allocation decreased cold ischemia time and DGF, which may improve graft survival.
The ‘new regionalism’ and foreign direct investment: the case of Mexico

The recent increase in foreign capital flows into developing countries has coincided with a new wave of regional trade agreements involving both developed and developing countries. This paper investigates the effect of the NorthAmerican Free TradeAgreement (NAFTA), a prime example of this new regionalism, on foreign direct investment in Mexico. Using data from the Mexican Ministry for Trade and Industrial Development (SECOFI), the major finding is that NAFTA has raised investment from the partner countries, the United States and Canada, but not from the rest of theworld. The increasing use of outsourcing and a commitment effect conveyed by the agreement are candidate explanations for a change in investors' sensitivity to the determinants of foreign direct investment.
A Critical Examination of the X-Wind Model for Chondrule and Calcium-rich, Aluminum-rich Inclusion Formation and Radionuclide Production

Meteoritic data, especially regarding chondrules and calcium-rich, aluminum-rich inclusions (CAIs), and isotopic evidence for short-lived radionuclides (SLRs) in the solar nebula, potentially can constrain how planetary systems form. Interpretation of these data demands an astrophysical model, and the 'X-wind' model of Shu et al. and collaborators has been advanced to explain the origin of chondrules, CAIs, and SLRs. It posits that chondrules and CAIs were thermally processed <0.1 AU from the protostar, then flung by a magnetocentrifugal outflow to the 2-3 AU region to be incorporated into chondrites. Here we critically examine key assumptions and predictions of the X-wind model. We find a number of internal inconsistencies: theory and observation show no solid material exists at 0.1 AU; particles at 0.1 AU cannot escape being accreted into the star; particles at 0.1 AU will collide at speeds high enough to destroy them; thermal sputtering will prevent growth of particles; and launching of particles in magnetocentrifugal outflows is not modeled, and may not be possible. We also identify a number of incorrect predictions of the X-wind model: the oxygen fugacity where CAIs form is orders of magnitude too oxidizing, chondrule cooling rates are orders of magnitude lower than those experienced bymore » barred olivine chondrules, chondrule-matrix complementarity is not predicted, and the SLRs are not produced in their observed proportions. We conclude that the X-wind model is not relevant to chondrule and CAI formation and SLR production. We discuss more plausible models for chondrule and CAI formation and SLR production.« less
Combinatorial solution of the two-matrix model

Abstract We write down and solve a closed set of Schwinger-Dyson equations for the two-matrix model in the large N limit. Our elementary method yields exact solutions for correlation functions involving angular degrees of freedom whose calculation was impossible with previously known techniques. The result sustains the hope that more complicated matrix models important for lattice string theory and QCD may also be solvable despite the problem of the angular integrations. As an application of our method we briefly discuss the calculation of wavefunctions with general matter boundary conditions for the Ising model coupled to 2D quantum gravity. Some novel insights into the relationship between lattice and continuum boundary conditions are obtained.
Line processor: a device for amplification of display terminal capabilities for text manipulation

The Line Processor is a microcomputer-based device that was developed at Stanford Research Institute's Augmentation Research Center (ARC). It was designed to make it possible to use inexpensive alphanumeric video display terminals with ARC's sophisticated interactive information manipulation system, NLS.
Bounded-influence estimators for the SURE model

Abstract This paper considers robust estimation of the seemingly unrelated regression equations (SURE) model. Following the infinitesimal approach to robustness, we characterize the class of optimal bounded-influence estimators and we propose two computationally simple estimators. We also present the results of a set of Monte Carlo experiments carried out to study the behavior of these estimators.
α-Metalation of 1-(tert-butoxycarbonyl)-1,2-dihydropyridines

Abstract The α-metalation-alkylation of 1-( tert -butoxycarbonyl)-1,2-dihydropyridines is described and utilized in the synthesis of (±)epi-myrtine.
TWO-DIMENSIONAL QUANTUM GRAVITY, MATRIX MODELS AND STRING THEORY

We review some results of the recent progress in understanding two-dimensional quantum gravity and low-dimensional string theories based on the lattice approach. The possibility to solve the lattice models exactly comes from their equivalence to large N matrix models. We describe various matrix models and their continuum limits, and discuss in some detail the phase structure of Hermitian one-matrix models. For the one-dimensional matrix model we discuss its field theoretic formulation through a collective field method and summarize some perturbative results. We compare the results obtained from matrix models to the results in the continuum approach to string theory.
A Remark on Solutions of the Pell Equation

The main purpose of this Note is to provide a non-trivial bound on certain Kloosterman sums as considered in the recent paper of E. Fouvry [F], leading to a small improvement of his result on the Pell equation.
Multiplicity of Generation, Selection, and Classification Procedures for Jammed Hard-Particle Packings †

Hard-particle packings have served as useful starting points to study the structure of diverse systems such as liquids, living cells, granular media, glasses, and amorphous solids. Howard Reiss has played a major role in helping to illuminate our understanding of hard-particle systems, which still offer scientists many interesting conundrums. Jammed configurations of hard particles are of great fundamental and practical interest. What one precisely means by a “jammed” configuration is quite subtle and considerable ambiguity remains in the literature on this question. We will show that there is a multiplicity of generation, selection, and classification procedures for jammed configurations of identical d-dimensional spheres. We categorize common ordered lattices according to our definitions and discuss implications for random disk and sphere packings. We also show how the concept of rigidity percolation (which has been used to understand the mechanical properties of network glasses) can be generalized to f...
Driven and Decaying Turbulence Simulations of Low-Mass Star Formation: From Clumps to Cores to Protostars

Molecular clouds are observed to be turbulent, but the origin of this turbulence is not well understood. As a result, there are two different approaches to simulating molecular clouds, one in which the turbulence is allowed to decay after it is initialized, and one in which it is driven. We use the adaptive mesh refinement (AMR) code, Orion, to perform high-resolution simulations of molecular cloud cores and protostars in environments with both driven and decaying turbulence. We include self-gravity, use a barotropic equation of state, and represent regions exceeding the maximum grid resolution with sink particles. We analyze the properties of bound cores such as size, shape, line width, and rotational energy, and we find reasonable agreement with observation. At high resolution the different rates of core accretion in the two cases have a significant effect on protostellar system development. Clumps forming in a decaying turbulence environment produce high-multiplicity protostellar systems with Toomre -->Q unstable disks that exhibit characteristics of the competitive accretion model for star formation. In contrast, cores forming in the context of continuously driven turbulence and virial equilibrium form smaller protostellar systems with fewer low-mass members. Our simulations of driven and decaying turbulence show some statistically significant differences, particularly in the production of brown dwarfs and core rotation, but the uncertainties are large enough that we are not able to conclude whether observations favor one or the other.
L-Selectride as a convenient reagent for the selective cleavage of carbamates

Abstract L-Selectride ® was shown to selectively cleave methyl carbamates in the presence of more sterically demanding carbamates, including the selective cleavage of a methyl carbamate in the presence of an N-Boc group.
A geometric approach to the Littlewood–Paley theory

We develop a geometric invariant Littlewood–Paley theory for arbitrary tensors on a compact 2 dimensional manifold. We show that all the important features of the classical LP theory survive with estimates which depend only on very limited regularity assumptions on the metric. We give invariant descriptions of Sobolev and Besov spaces and prove some sharp product inequalities. This theory has being developed in connection with the work of the authors on the geometry of null hypersurfaces with a finite curvature flux condition, see [KR1,2]. We are confident however that it can be applied, and extended, to many different situations.
Aspects of the physics, chemistry, and technology of high intensity heavy ion sources

Abstract Particular emphasis is placed on the technology of plasma discharge ion sources which utilize solid elemental or molecular compounds to produce vapor for the ionization process. A brief discussion is made of the elementary concepts underlying the formation and extraction of ion beams from plasma discharge sources. A limited review of low change state positive ion sources suitable for accelerator use is also given.
The Chemistry of Acetates on the Rh(111) Surface

Abstract The formation of acetates by the dissociation of acetic acid on the clean Rh(111) surface and by reactions of acetic acid, acetaldehyde, and ethanol with preadsorbed oxygen atoms was examined using HREELS and TPD. Acetate intermediates were identified by the characteristic vibrations of the OCO moiety symmetrically bonded to the surface via both oxygen atoms. Acetates formed from acetic acid on the clean Rh(111) surface decomposed via two pathways. CO scission by 278 K released adsorbed carbon monoxide and atomic oxygen; decarboxylation at 372 K liberated carbon dioxide and hydrogen. Acetates were formed after the adsorption of both ethanol and acetaldehyde on the Rh(111)-(2 × 2)O surface, as well as after the adsorption of acetic acid. For the alcohol and the aldehyde, the adsorbed intermediate involved in the reaction with atomic oxygen was likely η2(C,O)-acetaldehyde. For acetic acid on the Rh(111)-(2 × 2)O surface, acetates were formed via direct transfer of the acid hydrogens to the surface oxygen atoms to form surface hydroxyls. When oxygen atoms were present on the surface, the only pathway for acetate decomposition was decarboxylation at 430K. Thus coadsorbed oxygen atoms provide significant stabilization of acetates on Rh(111), as previously observed for formates on the same surface. In the presence of adsorbed oxygen, a portion of the methyl groups of surface acetates was oxidized to CO at temperatures below those expected for reactions of atomic carbon and oxygen species. This observation suggests that oxygen intervenes in the acetate decomposition pathway prior to the complete fragmentation of these intermediates.
Thermal properties of a hot pion gas beyond the quasiparticle approximation

Abstract Within the Matsubara formalism we derive expressions for the pion selfenergy and the two-pion propagator in a hot pion gas. These quantities are used to selfconsistently calculate the in-medium ππ amplitude beyond the quasiparticle approximation (QPA). The results are shown to differ significantly from QPA-based calculations. We also examine the impact of chiral constraints on the ππ interaction in a chirally improved version of the Julich ππ model.
Fractional statistics in one dimension: view from an exactly solvable model

Abstract One-dimensional fractional statistics is studied using the Calogero-Sutherland model (CSM) which describes a system of non-relativistic quantum particles interacting with an inverse-square two-body potential on a ring. The inverse-square exchange can be regarded as a pure statistical interaction and this system can be mapped to an ideal gas obeying the fractional exclusion and exchange statistics. The details of the exact calculations of the dynamical correlation functions or this ideal system is presented in this paper. An effective low-energy one-dimensional “anyon” model is constructed; and its correlation functions are found to be in agreement with those in the CSM; and this agreement provides an evidence for the equivalence of the first- and the second-quantized construction of the 1D anyon model at least in the long-wavelength limit. Furthermore, the finite-size scaling applicable to the conformally invariant systems is used to obtain the complete set of correlation exponents for the CSM.
Computer -controlled manipulator with visual inputs

A computer control algorithm utilizing the modern control theory and the heuristic artificial intelligence approach has been developed to control the MIT Scheinman electric arm. The control algorithm is task-oriented with the capabilities of accepting visual input coordination and discrete word voice commands in addition to the linguistic commands typed in by an operator at the remote terminal. The motion of the arm is considered to be composed of motion of the wrist and orientation of the hand. A human operator, always present in the control loop and interacting with the system, generates linguistic task-directed commands at the remote terminal. A task-directed command is recognized, interpreted, and decoded into sequence of subtasks. The first subtask corresponds to the motion of the wrist which is controlled by the suboptimal feedback controller. The remaining four subtasks are further broken down into combinations of six primitive movements which govern the position/orientation of the hand. The objective of the visual recognition algorithm is to identify ob-jects and their locations surrounding the arm from its environmental library or model. The library is then updated to initiate the arm to complete its execution of task. Areas and circumferences of the objects are the two features chosen for recognition. The recognition of an object is then based on the threshold value of the weighted sum of area and circumference of the object. The set of weights is trained again when a new object is introduced to the arm and incorporated into the library. The real-time implementation of the algorithm on AARL MIT arm connected to a PDP 11/45 computer shows that it can recognize the objects surrounding the arm within 50 seconds.
Highly stereoselective substitution reactions of functionalized η4-[3(E),5(E)-heptadien-2-ol]iron tricarbonyl complexes

Abstract Substituted η 4 -[3(E),5(E)-heptadien-2-ol)Fe(CO) 3 complexes 10a,b, 11a,b or the corresponding acetate derivatives 14, 20, 23, 25 and 28 undergo highly stereoselective Lewis acid mediated substitution reactions with various nucleophiles, including R 3 Al reagents, ketene silyl acetals, allyltributylstannane, allyltrimethylsilane, and trimethylsilylazide. Evidence is presented that these reactions proceed with retention of configuration.
The toric ideal of a graphic matroid is generated by quadrics

Describing minimal generating sets of toric ideals is a well-studied and difficult problem. Neil White conjectured in 1980 that the toric ideal associated to a matroid is generated by quadrics corresponding to single element symmetric exchanges. We give a combinatorial proof of White’s conjecture for graphic matroids.
Optimal growth with many consumers

Abstract A method is described for constructing all Pareto-optimal allocations for a dynamic economy with many heterogeneous consumers, under certainty, in which both the technology and consumer preferences are recursive but preferences need not be additively separable over time. Optimal (perfect foresight competitive equilibrium) allocations are obtained through the study of a dynamic program. For an economy with one consumption good, sufficient conditions are given for the existence of a unique interior stationary distribution of consumption and wealth. For a two-person exchange economy, sufficient conditions are given for the global asymptotic stability of the unique interior stationary point.
THE MULTIPLE SYSTEM HD 27638

We report spectroscopic observations of HD 27638 B, the secondary in a visual binary in which the physically associated primary (separation ~19'') is a B9 V star. The secondary shows strong Li λ6708 absorption, suggesting youth, and has attracted attention in the past as a candidate post-T Tauri star, although this has subsequently been ruled out. It was previously known to be a double-lined spectroscopic binary (F8+G6) with a period of 17.6 days and to show velocity residuals indicating a more distant massive third companion with a period of at least 8 yr. Based on our radial velocity measurements covering more than two cycles of the outer orbit, along with other measurements, we derive an accurate triple orbital solution giving an outer period of 9.447 ± 0.017 yr. The third object is more massive than either of the other two components of HD 27638 B but is not apparent in the spectra. We derive absolute visual magnitudes and effective temperatures for the three visible stars in HD 27638. Isochrone fitting based on those properties gives an age of 200 ± 50 Myr for the system. We also infer an inclination angle of ~533 for the inner orbit of HD 27638 B. We detect a near-infrared excess in HD 27638 B, which we attribute to the third star being a close binary composed of late-type stars. This explains its large mass and lack of a visible signature. Modeling of this excess allows us to infer not only the masses of the components of the unseen companion but also the inclination angle of the outer orbit (~73°). The HD 27638 system is thus at least quintuple.
A universal Polish G-space

Abstract If G is a Polish group, then the category of Polish G -spaces and continuous G -mappings has a universal object.
Magnified Effects of Changes in NIH Research Funding Levels

What happens within the university-based research enterprise when a federal funding agency abruptly changes research grant funding levels, up or down? We use simple difference equation models to show that an apparently modest increase or decrease in funding levels can have dramatic effects on researchers, graduate students, postdocs, and the overall research enterprise. The amplified effect is due to grants lasting for an extended period, thereby requiring the majority of funds available in one year to pay for grants awarded in previous years. We demonstrate the effect in various ways, using National Institutes of Health data for two situations: the historical doubling of research funding from 1998 to 2003 and the possible effects of “sequestration” in January 2013. We posit human responses to such sharp movements in funding levels and offer suggestions for amelioration.
Remote sensing through stratified random media using pupil-plane interferometry

We investigate a novel method for the retrieval of an arbitrary amplitude-object which is illuminated from the far-field and sampled through a stratified random medium of unknown statistics. The setup includes two observation paths, a CCD-based imaging system and a multiaperture interferometer placed in a plane conjugate to the entrance pupil of the imaging system. The interferometric baselines are arranged in closed loops to make the closure phase insensitive to random refractive fluctuations. The method may be beneficial to applications such as surveillance, speckle interferometry and biomedical imaging.
Mechanisms for the desorption of large organic molecules. Part 2

Abstract Models are reviewed for ejection of intact biomolecules and biomolecular ions in response to the electronic energy deposited by a fast heavy ion. These models are compared with laboratory data and molecular dynamics calculations. Over a limited range of electronic energy deposited per unit path length, the scaling of the total yield with energy deposition is understood, and it has been shown that, except for Langmuir-Blodgett films of fatty acids, the large intact ions are ejected primarily from the surface or adsorbed sites. The principal outstanding problems are a detailed description of the electronic energy conversion into molecular motion and the ion formation—neutralization process. An understanding of these is needed in order to improve sensitivity at the higher masses in PDMS.
Energy, central charge, and the BPS bound for 1 + 1-dimensional supersymmetric solitons

We consider one-loop quantum corrections to soliton energies and central charges in the supersymmetric θ4 and sine-Gordon models in 1 + 1 dimensions. In both models, we unambiguously calculate the correction to the energy in a simple renormalization scheme and obtain ΔH = −m/2π, in agreement with previous results. Furthermore, we show that there is an identical correction to the central charge, so that the BPS bound remains saturated in the one-loop approximation. We extend these results to arbitrary 1 + 1-dimensional supersymmetric theories.
The Formation of the First Stars. I. Mass Infall Rates, Accretion Disk Structure, and Protostellar Evolution

We present a theoretical model for primordial star formation. First we describe the structure of the initial gas cores as virialized, quasi-hydrostatic objects in accord with recent high-resolution numerical studies. The accretion rate can then be related to characteristic densities and temperatures that are set by the cooling properties of molecular hydrogen. We allow for rotation of the gas core, assuming angular momentum conservation inside the sonic point of the flow. In the typical case, most mass then reaches the star via an accretion disk. The structure of the inner region of this disk is described with the standard theory of viscous disks, but with allowance for the substantial energies absorbed in ionizing and dissociating the gas. The size of the protostar and its luminosity depend on the accretion rate, the energetics of the accreting gas, and the ability of the radiation to escape from the stellar accretion shock. We combine these models for the infall rate, inner disk structure, and protostellar evolution to predict the radiation field that is the basis for radiative feedback processes acting against infall (second paper in the series). For realistic initial angular momenta, the photosphere of the protostar is much smaller and hotter than in the spherical case, leading to stronger radiative feedback at earlier stages in the evolution. In particular, once the star is older than its Kelvin-Helmholtz time, contraction toward the main sequence causes a rapid increase in ionizing and far-ultraviolet luminosity at masses ~30 M? in the fiducial case. Since the cores out of which the first stars formed were much more massive than 30 M? and since feedback is dynamically unimportant at lower masses, we conclude that the first stars should have had masses 30 M?.
Laboratory-tutorial activities for teaching probability

We report on the development of students' ideas of probability and probability density in a University of Maine laboratory-based general education physics course called Intuitive Quantum Physics. Students in the course are generally math phobic with unfavorable expectations about the nature of physics and their ability to do it. We describe a set of activities used to teach concepts of probability and probability density. Rudimentary knowledge of mechanics is needed for one activity, but otherwise the material requires no additional preparation. Extensions of the activities include relating probability density to potential energy graphs for certain ``touchstone'' examples. Students have difficulties learning the target concepts, such as comparing the ratio of time in a region to total time in all regions. Instead, they often focus on edge effects, pattern match to previously studied situations, reason about necessary but incomplete macroscopic elements of the system, use the gambler's fallacy, and use expectations about ensemble results rather than expectation values to predict future events. We map the development of their thinking to provide examples of problems rather than evidence of a curriculum's success.
SYNTHESIS AND MOLECULAR STRUCTURE OF HYDROGEN-BONDED CYCLIC ANIONIC SILICATES ISOELECTRONIC WITH PHOSPHORANES. STRUCTURAL PRINCIPLES OF FIVE-COORDINATED SILICON

Abstract The new five-coordinated silicon compounds, pyridinium bis(2,3-naphthalenediolato)phenylsilicate(IV), [(C10H6O2)2SiPh][C5H6N], 11, pyridinium bis(1,2-benzenediolato)-1-naphthylsilicate(IV), [(C6H4O2)2SiC10H7][C5H6N], 12, and pyridinium bis(1,2-benzenediolato)(2- and 4-chlorophenyl)silicate(IV) (2-Cl, 0.85; 5-Cl, 0.15), [(C6H4O2)2SiC6H4Cl][C5H6N], 13, were synthesized and their X-ray structures determined. The structure of 11 is nearly an ideal rectangular pyramid (RP) and 12 is displaced about halfway between the RP and trigonal bipyramid (TBP), while 13 is closer to a TBP. A quantitative assessment of these and related pentacoordinated cyclic anionic silicate structures reveals a continuous change in ring Si[sbnd]O bond lengths that vary from 1.78 (axial) and 1.68 A (equatorial) for the idealized TBP to 1.73 A (basal) for the RP. The results for these compounds, all of which follow the Berry pseudorotational coordinate, suggest a structural nonrigidity at least as great as found for phosphoranes...
The student productivity paradox: technology mediated learning in schools

This is the author’s version of a work that was accepted for publication in the Communications of the ACM. Editorial and formatting changes may have been made to this version since it was submitted for publication. The final version of the article is available through licensed access provided by the publisher. Published in Communications of the ACM, 51(9), 128-131. doi: 10.1145/1378727.1389974. Members of the USF System may access the full-text of the article through the authenticated link provided below.
INCORPORATION OF SELENOCYSTEINE INTO PROTEINS USING PEPTIDE LIGATION

Expressed protein ligation has become a frequently used technique to insert non-standard amino acids into proteins. The technique has been adapted to insert selenocysteine residues in place of cysteine residue in proteins, taking advantage of the similarity in the chemistries of sulfur and selenium. This replacement can confer unique structural and catalytic properties to enzymes and proteins. The development of this technique also allows for naturally occurring selenoproteins to be produced semisynthetically.
Independent and combined effects of inhaled nitric oxide, liquid perfluorochemical, and high-frequency oscillatory ventilation in premature lambs with respiratory distress syndrome.

Acute lung injury caused by tidal volume ventilation in the premature lamb with respiratory distress syndrome (RDS) is characterized by progessive deterioration in gas exchange and lung inflammation. Inhaled nitric oxide (iNO) improves gas exchange and decreases lung neutrophil accumulation in premature lambs with RDS. Mechanical lung recruitment techniques such as high-frequency oscillatory ventilation (HFOV) and partial liquid ventilation (PLV) also decrease lung injury and improve gas exchange in experimental models of neonatal respiratory failure. We hypothesized that two lung recruitment strategies (HFOV and PLV) would have similar effects on gas exchange and lung inflammation, and would augment the response to iNO. We studied the individual and combined effects of iNO, HFOV, and PLV (perflubron) in 31 extremely premature lambs (115 d, 0.78 term) using seven mechanical ventilation protocols. Four groups were treated with conventional ventilation (control CV, CV + iNO, CV + PLV, and CV + PLV + iNO). T...
Separating Turbofan Engine Noise Sources Using Auto and Cross Spectra from Four Microphones

The study of core noise from turbofan engines has become more important as noise from other sources such as the fan and jet were reduced. A multiple-microphone and acoustic-source modeling method to separate correlated and uncorrelated sources is discussed. The auto- and cross spectra in the frequency range below 1000 Hz are fitted with a noise propagation model based on a source couplet consisting of a single incoherent monopole source with a single coherent monopole source or a source triplet consisting of a single incoherent monopole source with two coherent monopole point sources. Examples are presented using data from a Pratt& Whitney PW4098 turbofan engine. The method separates the low-frequency jet noise from the core noise at the nozzle exit. It is shown that at low power settings, the core noise is a major contributor to the noise. Even at higher power settings, it can be more important than jet noise. However, at low frequencies, uncorrelated broadband noise and jet noise become the important factors as the engine power setting is increased.
Molecular Dynamics Study of the Stabilization of the Silica Hexamer Si6O156- in Aqueous and Methanolic Solutions

We use molecular dynamics simulations to study the stabilization of the hexameric, cagelike silicate with double three-ring structure in aqueous and methanolic solutions. We find that in purely aqueous environments its stabilization requires the presence of both tetramethylammonium and tetraethylammonium (TEA) cations and involves the formation of a stable TMA layer which leads to a water-silicate heteronetwork clathrate. We also find that TEA alone can facilely stabilize the hexamer when methanol cosolvent is added, in accordance with experiment. The mechanism of this stabilization, however, differs from that in purely aqueous environments. Because of the unique properties of water-methanol mixtures, the organosilicate complex does not participate in heteronetwork clathrates but resides in a large solvent cavity; that is, it is forced out of true solution.
Stereochemistry of the 1,2-Wittig rearrangement: A synthesis of syn-1,3-diol monoethers

Abstract The [1,2] Wittig rearrangement of β-alkoxyalkyl allyl ethers has been studied and found to provide syn-1,3-diol derivatives in 14–32% yield and with useful levels of diastereoselection.
COBIOTECH's role in biotechnology worldwide.

Curious or skeptical friends often ask, “What and why is COBIOTECH? What is it doing?” After serving as president during its formative first years, I attempt here to provide information for the curious and allay concerns of the skeptics about COBIOTECH'S emerging role in biotechnology internationally.
SOLAR XUV LIMB BRIGHTENING OBSERVATIONS I: The Lithium-Like Ions

OSO-IV observations of the equatorial limb brightening of XUV resonance lines of Nv, O vi, Ne viii, Mg x and Si xii are interpreted with a modified version of a coronal model developed by Dupree and Goldberg (1967). Good agreement is obtained between the observed limb brightening and that predicted by the model. The sensitivity of the predicted limb-brightening curves to changes in parameters describing the model is discussed. Coronal abundances for N, O, Ne, Mg, and Si are obtained.
Dispersion And Gas Flow Effects In The Ring Laser Gyro

The effects of dispersion and gas flow on the operation of the ring laser gyro are summarized. The theory is shown to predict a dimple in the anomalous dispersion properties of the atomic transition. Experiments were carried out using a 43.4 cm and 21.7 cm visible laser gyro. Scale factor and nullshift results showed consistency and confirmed the existence of the dimple. The peak-peak relative magnitude of the scale factor dimple was found to be approximately 25 x 10-6. Gas flow was varied by unbalancing the discharge currents in the two legs of the laser gyro. A nullshift sensitivity of 0.0066 deg/hr/mamp of unbalance was found. Analysis of the data showed the nullshift sensitivity to velocity flow to be 4.4 deg/hr/cm/sec of velocity unbalance.
A framework for financial market development

A framework for examining the process of financial market development is proposed. The framework is anchored in studying the incentives facing the key players in financial markets – borrowers, lenders, liquidity providers, and regulators – whose actions determine whether and how markets develop. While different financial instruments embody different concessions by borrowers and lenders, the framework emphasizes two main compromises: the tradeoffs between maturity and collateral, and between seniority and control in the sequencing of market development.