cssi/SciSciGPT-SciSciNet huggingface dataset:
A DEEP XMM-NEWTON OBSERVATION OF THE QUASAR 3C 287

We report on an XMM-Newton observation of the z = 1.055 quasar and Gigahertz Peaked Spectrum (GPS) source 3C 287. Our 62.3 ks observation provides an exceptional X-ray view of a prominent member of this important subclass of active galactic nuclei (AGNs). The X-ray spectra of 3C 287 are consistent with a simple absorbed power law with a spectral index of Γ = 1.72 ± 0.02. Our fits imply a bolometric luminosity of L = 5.8 ± 0.2 × 1045 erg s–1 over the 0.3-10.0 keV band; this gives a mass lower limit of M BH min ≥ 4.6 × 107 M ☉ assuming X-rays contribute 10% of the bolometric luminosity and radiation at the Eddington limit. Iron emission lines are common in the X-ray spectra of many AGNs, but the observed spectra appear to rule out strong emission lines in 3C 287. The simple power-law spectrum and the absence of strong emission lines may support a picture where our line of sight intersects a relativistic jet. Milliarcsecond radio imaging of 3C 287 appears to support this interpretation. We discuss our results in the context of different AGNs subclasses and the possibility that GPS sources harbor newly formed black hole jets.
Linoleic Acid Suppresses Cholesterol Efflux and ATP-Binding Cassette Transporters in Murine Bone Marrow-Derived Macrophages

Individuals with type 2 diabetes mellitus (T2DM) are at increased risk of developing cardiovascular disease (CVD), possibly associated with elevated plasma free fatty acid concentrations. Paradoxically, evidence suggests that unsaturated, compared to saturated fatty acids, suppress macrophage cholesterol efflux, favoring cholesterol accumulation in the artery wall. Murine bone marrow-derived macrophages (BMDM) were used to further explore the relationship between saturated and unsaturated fatty acids, and cholesterol efflux mediated by ATP-binding cassette transporters (ABCA1 and ABCG1) through transcription factors liver-x-receptor-alpha (LXR-α) and sterol receptor element binding protein (SREBP)-1. BMDM isolated from C57BL/6 mice were exposed to 100 μM linoleic acid (18:2) or palmitic acid (16:0) for 16 h, and 25 μg/mL oxidized low density lipoprotein for an additional 24 h. ABCA1 and ABCG1 mRNA expression was suppressed to a greater extent by 18:2 (60 % and 54 %, respectively) than 16:0 (30 % and 29 %, respectively) relative to the control (all p < 0.01). 18:2 decreased ABCA1 protein levels by 94 % and high density lipoprotein (HDL) mediated cholesterol efflux by 53 % (both p < 0.05), and had no significant effect on ABCG1, LXR-α or SREBP-1 protein levels. 16:0 had no effect on ABCA1, ABCG1, LXR-α or SREBP-1 protein expression or HDL-mediated cholesterol efflux. These results suggest that 18:2, relative to 16:0, attenuated macrophage HDL-mediated cholesterol efflux through down regulation of ABCA1 mRNA and protein levels but not through changes in LXR-α or SREBP-1 expression. The effect of 18:2 relative to 16:0 on macrophages cholesterol homeostasis may exacerbate the predisposition of individuals with T2DM to increased CVD risk.
Oxidative deiodination of cubyl iodides: A tactic for the nucleophilic introduction of substituents onto the cubane framework

Abstract Iodocubanes are oxidized by peracids, etc. to relatively stable hypervalent iodine species which upon mild, thermally-induced decomposition produce new cubanes in which the original iodide substituent is replaced.
EFFECT OF CORTISOL TREATMENT ON HORMONAL RELATIONSHIPS IN CONGENITAL ADRENAL HYPERPLASIA

SUMMARY The temporal relationship between administration of cortisol and serum 17ahydroxyprogesterone was investigated in five patients aged 9-19 years with congenital adrenal hyperplasia due to 21-hydroxylase deficiency. There was marked variability in the 17a-hydroxyprogesterone response (determined hourly for 24 h) of individual patients to administration of cortisol. Mean concentration was less than 0.030 pmol/l in one patient but 0.519 pmol/l in another. Levels were higher in all patients while off treatment, and were greatest in those with salt-losing adrenal hyperplasia. Growth hormone secretion was not suppressed by treatment with cortisol. Withdrawal of cortisol for 3 days resulted in a significant decrease in the mean serum FSH/LH ratio and a rise in serum testosterone in all subjects. Episodic release of gonadotrophins persisted in the adolescent patients. Abnormalities of growth occur in patients with congenital adrenal hyperplasia (CAH). Excessive glucocorticoid treatment causes stunting, whereas inadequate therapy results in a rapid increase in height. It is frequently difficult to determine the precise regimen which will suppress androgen secretion without inhibiting linear growth. Recommended doses of cortisol* vary from 15 to 40 mg/m2/day (Laron & Pertzelan, 1968; Rappaport eta!., 1968). In the present study the temporal relationship between oral administration of cortisol and the serum concentration of 17a-hydroxyprogesterone (17-OHP) was studied during a 24 h period to determine if the typical every-8-h dosage schedule provides adequate adrenal suppression. Serum concentrations of growth hormone (GH), total corticoids, follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone were also determined.
THE GREAT MEXICAN EMIGRATION

Abstract In this paper, we examine net emigration from Mexico over the period 1960 to 2000. The data are consistent with labor supply shocks having made a substantial contribution to Mexican emigration, accounting for two-fifths of Mexican labor flows to the United States over the last two decades of the twentieth century. Net emigration rates by Mexican state birth year cohort display a strong positive correlation with the initial size of the Mexican cohort relative to the corresponding U.S. cohort. In states with long histories of emigration, the effects of cohort size on emigration are relatively strong, consistent with the existence of preexisting networks.
An algorithm for computing the integral closure

We present an algorithm for computing the integral closure of a reduced ring that is finitely generated over a finite field. Leonard and Pellikaan [2003] devised an algorithm for computing the integral closure of weighted rings that are finitely generated over finite fields. Previous algorithms proceed by building successively larger rings between the original ring and its integral closure [de Jong 1998; Seidenberg 1970; 1975; Stolzenberg 1968; Vasconcelos 1991; 2000]; the Leonard‐Pellikaan algorithm instead starts with the first approximation being a finitely generated module that contains the integral closure, and successive steps produce submodules containing the integral closure. The weights in [Leonard and Pellikaan 2003] impose strong restrictions, and play a crucial role in various steps of their algorithm; see Remark 1.7. We present a modification of the Leonard‐Pellikaan algorithm that works in much greater generality: it computes the integral closure of a reduced ring that is finitely generated over a finite field. We discuss an implementation of the algorithm in Macaulay 2, and provide comparisons with de Jong’s algorithm [1998].
How Surprising is a New Record

This article presents a novel and simple way to assess the exceptionality of a new record. We illustrate the use of this measure in two examples, one from archaeology and the other from athletics.
Almost Extrinsically Homogeneous Submanifolds of Euclidean Space

Consider a closed manifold M immersed in R m . Suppose that the trivial bundle M × R m = T M ⊗ ν M is equipped with an almost metric connection ~ ∇ which almost preserves the decomposition of M × R m into the tangent and the normal bundle. Assume moreover that the difference Γ = ∂~∇ with the usual derivative ∂ in R m is almost ~∇-parallel. Then M admits an extrinsically homogeneous immersion into R m . Mathematics Subject Classifications (2000): 53C20, 53C24, 53C30, 53C42, 53C40.
Investigation of porphyrin-forming reactions. Part 2. Examination of the reaction course in two-step, one-flask syntheses of meso-substituted porphyrins

The reaction course leading to meso-substituted porphyrins was examined for reversibility (formation of oligomers, formation of α- and β-pyrrole linkages), inactivation of the acid catalyst, homogeneity of the reaction medium, and the pathway of oligomer formation. The methodology employed enabled characterization of the oligomer composition (LD-MS), yield of porphyrin (UV–Vis), yield of N-confused porphyrin (HPLC), and level of unreacted aldehyde (TLC). Experiments were performed with benzaldehyde and pyrrole with catalysis by TFA or BF3–Et2O. Key observations include the following. (1) Reactions with BF3–Et2O exhibited reversible exchange of oligomers throughout the reaction. With TFA, the oligomer exchange processes were reversible at short reaction times, but became largely irreversible over the course of several hours. (2) The BF3–Et2O activity declined during the course of the reaction, whereas that of TFA was little changed. (3) The reaction medium remained homogeneous at 10 mM pyrrole + aldehyde. (4) Dipyrromethanes comprised of α- but not β-linkages underwent cleavage with either TFA or BF3–Et2O. (5) Condensations with carbinol intermediates (pyrrole-carbinol, dipyrromethane-monocarbinol, dipyrromethane-dicarbinol) provided rapid reactions, lower yields of porphyrin, and longer oligomers than typical in reactions of pyrrole + benzaldehyde. Higher porphyrin yields were obtained with BF3–Et2O than TFA, which is attributed to the more facile recovery from longer oligomers with the former versus the latter catalyst. Collectively, these and other observations lead to a model for the aldehyde + pyrrole condensation comprised of a combination of irreversible and reversible reactions in oligomer formation, irreversible side reactions (formation of dipyrrins, β-linkages), and slow inactivation of the catalyst (BF3–Et2O).
Computer‐assisted synthetic analysis. Quantitative assessment of transform utilities

A novel scheme for assigning initial, or substrate-independent, ratings for transforms (retroreactions) in the chemical knowledge base for the LHASA program for computer-assisted synthetic analysis is described. The new rating scheme is based on keyword scales defined for eight rating criteria. Initial ratings are calculated as weighted averages of the ratings in the eight categories. Various applications of initial ratings in LHASA are outlined.
Prediction of Turbulent Flow and Heat Transfer in a Radially Rotating Square Duct

The present study deals with the numerical prediction of turbulent flow and heat transfer in a rotating duct of square cross section. The axis of rotation is normal to the axis of the duct, and the flow is radially outward. The duct is smooth, of finite length, and the walls are isothermal at a temperature greater than the temperature of the incoming fluid. Both the Coriolis and the centrifugal-buoyancy effects are considered; the problem is three dimensional and fully elliptic. The predicted flow field is found to be quite complex, consisting of secondary cross-stream flows due to the Coriolis effects
Financial performance of publicly‐traded agribusinesses

Purpose – Agribusinesses represent a fundamental link in connecting farmers with retailers and consumers, yet little research has been done to examine the historical financial performance of these food processing firms. This paper aims to address this issue.Design/methodology/approach – The authors' research examines how publicly‐traded agribusinesses perform financially compared to all firms over the period from 1961 to 2011. The authors utilize several indicators of company success, including financial ratios and balance sheet/income statement items, to compare agribusiness firms to all firms in the market. The authors perform the analysis over time and also for companies with low, median, and high performance. They also perform Du Pont analysis to compare return on equity components between agribusinesses and all firms.Findings – The authors find that agribusinesses outperform at the median the sample of all firms in terms of financial ratios related to profitability, liquidity, and market ratios, but ...
Termination of systemic immunity in the presence of intraocular tumors: influence of ocular immune privilege on tumor vaccines.

Ocular immune privilege preserves the visual axis by preventing the induction of sight-threatening nonspecific inflammation. Although privilege is essential for maintaining visual integrity, intraocular tumors exploit the privileged environment and grow progressively within the anterior chamber of the eye. Recently, a large number of laboratories have constructed genetically engineered tumor cell vaccines that express high levels of costimulatory signals. These vaccines are designed to bypass the normal pathways of T-cell activation and directly activate CD8+ tumor-specific T cells. In the following series of experiments, we determined whether a tumor cell vaccine that uses costimulatory signals (CD80 and IL-12) is capable of eliminating tumors within the immune-privileged anterior chamber. As expected, vaccine-immunized mice rejected subcutaneous flank tumors (a non-privileged site). However, the vaccine failed to protect mice from even a small number of tumor cells transplanted into the immune-privilege...
Communication Network Characteristics of Open Source Communities

Empirical research has shown that social network structure is a critical success factor for various kinds of work groups. The authors extended this research to a new type of work groupâthe open source software project communityâwith the objective of exploring the role of communication networks within these intriguing projects. Using archival data from 143 open source project groups, the authors compiled six measures of social network structure and analyzed these in relation to four measures of group success. This study found that the social network structures of these project communities did not appear to be critical success factors at all, but rather they had no significant impact on success or their effect was opposite of that seen in prior studies of work groups. Various conjectures were suggested that might explain these results, offering opportunities for further research.
Tetrahydropyran rings from a Mukaiyama-Michael cascade reaction.

A new annulation reaction leading to tetrahydropyrans has been discovered. The reaction of homoallylic enol ethers (e.g., 1) with α,β-unsaturated ketones or esters begins with a Mukaiyama−Michael addition. The intermediate oxocarbenium ion undergoes a rapid 2-oxonia-Cope rearrangement, and the resulting zwitterion collapses to form a tetrahydropyran. The reaction is stereoselective with 3-butene-2-one, but leads to diastereomeric mixtures with ethyl acrylate. More complex enones, such as cyclohexenone, also undergo the reaction to produce fused ring products. The optical activity of the substrates is relayed in the tetrahydropyran products.
Integral representation of renormalized self-intersection local times

In this paper we apply Clark–Ocone formula to deduce an explicit integral representation for the renormalized self-intersection local time of the d-dimensional fractional Brownian motion with Hurst parameter H∈(0,1). As a consequence, we derive the existence of some exponential moments for this random variable.
The psychological experience of security officers who work with executions.

The Louisiana and Alabama “Execution Teams” were interviewed in order to understand the roles, experiences, and effects of carrying out the death penalty. One hundred twenty out of a possible one hundred twenty-four correctional officers were interviewed. Of those questioned, one hundred fifteen completed mental health inventories. The subjects were grouped based on their roles in order to gain a broade r picture of the steps and their impact in carrying out the death penalty. Our results show that participants in the execution process stress “caring professionalism.” There is an overwhelming emphasis on carrying out one ’s job at a high level. At the same time, officers are neither dehumanized nor callous, describing acting with respect and decency toward all involved. While their job is their prima facie duty, they experience stress an d emotional reactions, frequently having a hard time carrying out society’s “ultimate punishment.”
SOBOLEV REGULARITY OF WEIGHTED BERGMAN PROJECTIONS ON THE UNIT DISC

We show that weighted Bergman projections corresponding to radially symmetric weights on &#x1d53b; are bounded on Sobolev spaces.
“Instant Methylide” Modification of the Corey–Chaykovsky Epoxide Synthesis

Abstract We report that Me3S(O)+I− (1) and Me3S+I− (2) form stable, dry mixtures with KOt-Bu and NaH, respectively, which remain stable upon prolonged storage (>1 year). The corresponding methylides (Me2SO=CH2 and Me2S=CH2) are generated upon addition of DMSO or DMSO/THF solutions of carbonyl compounds, cleanly affording epoxides via the Corey–Chaykovsky reaction in good yields and short reaction times (as short as 20 min when 1–2 mmol of various ketones and aldehydes were treated with a mixture of 1 and KOt-Bu at 50–60°C).
Boolean Function Monotonicity Testing Requires (Almost) n 1/2 Non-adaptive Queries

We prove a lower bound of Ω(n1/2-c), for all c> 0, on the query complexity of (two-sided error) non-adaptive algorithms for testing whether an n-variable Boolean function is monotone versus constant-far from monotone. This improves a ~Ω(n1/5) lower bound for the same problem that was obtained in [6], and is very close to the recent upper bound of ~O(n1/2/e2) by Khot et al. [13].
Electron Transfer and Molecular Recognition in Metallocene‐Containing Dendrimers

This manuscript provides a summary of the relatively large body of research on the preparation and characterization of dendrimers containing (1) multiple copies of metallocene residues on their surfaces or (2) a single metallocene residue at their core. Special emphasis is placed on dendrimers functionalized with either ferrocene or cobaltocenium groups, because their reversible electrochemistry makes them particularly attractive to the author's group. Dendrimers containing multiple, peripheral metallocene residues are of interest to develop multivalent interactions with suitable receptors or receptor assemblies. With dendrimers containing a single metallocene at their cores, the key questions relate to the effects of the dendritic mass on their properties and degree of encapsulation or site isolation. We focused our work on the electrochemical properties of these dendrimers as well as on their use as guests in molecular recognition processes with freely diffusing hosts.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
On the Consequences of the Symmetry of the Nuclear Hamiltonian on the Spectroscopy of Nuclei

The structure of the multiplets of nuclear terms is investigated, using as first approximation a Hamiltonian which does not involve the ordinary spin and corresponds to equal forces between all nuclear constituents, protons and neutrons. The multiplets turn out to have a rather complicated structure, instead of the $S$ of atomic spectroscopy, one has three quantum numbers $S$, $T$, $Y$. The second approximation can either introduce spin forces (method 2), or else can discriminate between protons and neutrons (method 3). The last approximation discriminates between protons and neutrons in method 2 and takes the spin forces into account in method 3. The method 2 is worked out schematically and is shown to explain qualitatively the table of stable nuclei to about Mo.
Morphology and motion of the interface between amorphous and crystalline cobalt disilicide

Abstract Amorphous CoSi2 films were prepared by codeposition onto electron-transparent silicon nitride window substrates. The deposits were crystallized in situ without further processing. Two sets of experiments were done: thermal crystallization and thermal crystallization with additional ion-irradiation treatments before or during crystallization. The interface between the amorphous and crystalline material is rough on the scale of 20 nm with some tendency to facet. Irradiation by 1.5 MeV Kr ions stimulates both nucleation and growth at room temperature. Prior ion-irradiation followed by heating in the absence of an ion-flux also enhances the nucleation and growth kinetics relative to a purely thermal treatment.
Modeling combustion of hydrazinium nitroformate

Combustion of hydrazinium nitroformate (HNF), N2H5C(NO2)3, has been modeled and the resultscompared with experimental observations including steady regression rate (pressure, initial temperature, and radiant flux sensitivities), surface temperature, and linear frequency response to radiation. The underlying philosophy of the approach is to compare HNF combustion with a wide range of experimental conditions as much as possible. The results indicate that HNF condensed-phase decomposition is overall slightly exothermic (increasing with pressure) with activation energy similar to that for proton transfer between hydrazinium and nitroformate ions. The gas-phase flame is highly exothermic (also slightly increasing with pressure) with low-activation energy, suggesting the gas-phase process is more like a lowenergy barrier (low Eg), chain-carrier process than a high-energy thermal process, similar to what has been suggested for nitrocellulose-nitroglycerine double-based propellant and for cyclo-tetramethylene-tetranitramine. For both of these materials, and now for HNF, the low-Eg model has been shown to be in good agreement with experimental data for both steady and unsteady burning rate. The model also demonstrates the ability to capture an importants manifestation of nonlinear combustion. The prediction of a stronginitial pressurization spike in a low L* (high dP/dt) end-burning (no cross-flow) motor with HNF propellant confirms our recent hypothesis that initial pressurization spikes may be due to nonlinear dynamic combustion in addition to (or instead of) erosive burning.
Novel neutron focusing mirrors for compact neutron sources

Abstract We demonstrated neutron beam focusing and neutron imaging using axisymmetric optics, based on pairs of confocal ellipsoid and hyperboloid mirrors. Such systems, known as Wolter mirrors, are commonly used in x-ray telescopes. A system containing four nested Ni mirror pairs was implemented and tested by focusing a polychromatic neutron beam at the MIT Reactor and conducting an imaging experiment at HFIR. The major advantage of the Wolter mirrors is the possibility of nesting for large angular collection. Using nesting, the relatively short optics can be made comparable to focusing guides in flux collection capabilities. We discuss how such optics can be used as polychromatic lenses to improve the performance of small-angle-scattering, imaging, and other instruments at compact neutron sources.
UHV piezoelectric translator

Abstract A UHV compatible piezoelectric translator has been developed to correct for angular misalignments in the crystals of a UHV X-ray monochromator. The unit is small, bakeable to 150°C, and use only ceramic materials for insulation. We report on the construction details, vacuum compatibility, mechanical properties, and uses of the device.
Catalytic nucleophilic glyoxylation of aldehydes.

β-Silyloxy-α-keto esters are prepared through a cyanide-catalyzed benzoin-type reaction with silyl glyoxylates and aldehydes. The products undergo a dynamic kinetic resolution to provide enantioenriched orthogonally protected alcohols and can be converted to the corresponding β-silyloxy-α-amino esters.
Preparation and facile cyclization of 5-alkyn-1-yllithiums

Abstract Primary 5-hexyn-1-yllithiums, which may be generated in virtually quantitative yield by low-temperature lithium-iodine interchange, undergo regiospecific 5-exo-dig cyclization via stereoselectively syn-addition of CH 2 Li to the alkyne moiety to give vinyllithiums that may be trapped with any of a variety of electrophiles to deliver functionalized cyclopentylidene- containing products.
Economic crisis and mental health

Purpose of reviewLiterature from the past year was examined to learn whether economic recessions have an effect on mental disorders including depression and suicides.Recent findingsEconomic recessions and crises have a context-dependent negative impact on mental health disorders. These appear in low
Constructing piecewise-polynomial lyapunov functions for local stability of nonlinear systems using Handelman's theorem

In this paper, we propose a new convex approach to stability analysis of nonlinear systems with polynomial vector fields. First, we consider an arbitrary convex polytope that contains the equilibrium in its interior. Then, we decompose the polytope into several convex sub-polytopes with a common vertex at the equilibrium. Then, by using Handelman's theorem, we derive a new set of affine feasibility conditions -solvable by linear programming- on each sub-polytope. Any solution to this feasibility problem yields a piecewise polynomial Lyapunov function on the entire polytope. This is the first result which utilizes Handelman's theorem and decomposition to construct piecewise polynomial Lyapunov functions on arbitrary polytopes. In a computational complexity analysis, we show that for large number of states and large degrees of the Lyapunov function, the complexity of the proposed feasibility problem is less than the complexity of certain semi-definite programs associated with alternative methods based on Sum-of-Squares or Polya's theorem. Using different types of convex polytopes, we assess the accuracy of the algorithm in estimating the region of attraction of the equilibrium point of the reverse-time Van Der Pol oscillator.
Diffuse scattering measurements of static atomic displacements in crystalline binary solid solutions

Diffuse x-ray scattering from crystalline solid solutions is sensitive to both local chemical order and local bond distances. In short-range ordered alloys, fluctuations of chemistry and bond distances break the long-range symmetry of the crystal within a local region and contribute to the total energy of the alloy. Recent use of tunable synchrotron radiation to change the x-ray scattering contrast between elements has greatly advanced the measurement of bond distances between the three kinds of atom pairs found in crystalline binary alloys. The estimated standard deviation on these recovered static displacements approaches ± 0.001 a (± 0.0001 nm), which is an order of magnitude more precise than obtained with extended x-ray absorption fine structure measurement. In addition, both the radial and tangential displacements can be recovered to five near neighbors and beyond. These static displacement measurements provide new information that challenges the most advanced theoretical models of binary crystalline alloys.
Remote power systems with advanced storage technologies for Alaskan villages

Abstract This paper presents an analytical optimization of a remote power system for a hypothetical Alaskan village. The analysis considers the potential of generating renewable energy (e.g., wind and solar), along with the possibility of using energy storage to take full advantage of the intermittent renewable sources available to these villages. Storage in the form of either compressed hydrogen or zinc pellets can then provide electricity from hydrogen or zinc–air fuel cells whenever wind or sunlight are low. The renewable system is added on to the existing generation system, which is based on diesel engines. Results indicate that significant reductions in fossil fuel consumption in these remote communities are cost effective using renewable energy combined with advanced energy storage devices. A hybrid energy system for the hypothetical village can reduce consumption of diesel fuel by about 50% with annual cost savings of about 30% by adding wind turbines to the existing diesel generators. Adding energy storage devices can further reduce fuel use, and depending on the economic conditions potentially reduce life-cycle costs. With optimized energy storage, use of the diesel gensets can be reduced to almost zero, with the existing equipment only maintained for added reliability. However, about one quarter of the original fuel is still used for heating purposes.
Refinement of the crystal structure of NdGe2Ni2

Abstract The structure of NdGe 2 Ni 2 was refined using single-crystal X-ray data. The refinement shows the crystal structure of NdGe 2 Ni 2 is tetragonal with the Al 4 Ba-type structure with the space group I4/mmm (No. 139), a =4.123(4) A, c =9.841(2) A, V =167.3(2) A 3 and Z =2 at room temperature.
Smooth submanifolds intersecting any analytic curve in a discrete set

We construct examples of C∞ smooth submanifolds in ℂn and ℝn of codimension 2 and 1, which intersect every complex, respectively real, analytic curve in a discrete set. The examples are realized either as compact tori or as properly imbedded Euclidean spaces, and are the graphs of quasianalytic functions. In the complex case, these submanifolds contain real n-dimensional tori or Euclidean spaces that are not pluripolar while the intersection with any complex analytic disk is polar.
Constraints on the Cosmic Near Infrared Background Excess from NICMOS Deep Field Observations

NICMOS observations of the resolved object fluxes in the Hubble Deep Field-North and the Hubble Ultra Deep Field are significantly below the fluxes attributed to a 1.4-1.8 μm near-infrared background excess (NIRBE) from previous low spatial resolution NIRS measurements. Tests placing sources in the NICMOS image with fluxes sufficient to account for the NIRBE indicate that the NIRBE flux must be either flat on scales greater than 100'' or clumped on scales of several arcminutes to avoid detection in the NICMOS image. A fluctuation analysis of the new NICMOS data shows a fluctuation spectrum consistent with that found at the same wavelength in deep 2MASS calibration images. The fluctuation analysis shows that the majority of the fluctuation power comes from resolved galaxies at redshifts of 1.5 and less and that the fluctuations observed in the earlier deep 2MASS observations can be completely accounted for with normal low-redshift galaxies. Neither the NICMOS direct flux measurements nor the fluctuation analysis require an additional component of near-infrared flux other than the flux from normal resolved galaxies in the redshift range between 0 and 7. The residual fluctuations in the angular range between 1'' and 10'' is 1-2 nW m-2 sr-1, which is at or above several predictions of fluctuations from high redshift Population III objects, but inconsistent with attributing the entire NIRBE to high-redshift galaxies.
Algorithms and experiments for structural mechanics on high-performance architectures

Abstract Given a finite element model of a structure and a set of external loads, one of the primary objectives of elastic analysis and structural dynamics is to determine the internal forces, leading to the resulting stresses, strains, and displacements. Considering the increasing demands upon the structural engineer to analyze larger and more complex structures, the need for multiprocessing and/or vectorization of the numerical schemes being used is substantial if time-to-solution reductions are desired. The simplest approach to structural mechanics computations is the formation and Cholesky factorization of the global stiffness matrix K . On the other hand, inherent ill-conditioning in K often requires extended precision computations. As a result, alternatives to the formation of K , such as orthogonal factorization and preconditioned conjugate gradient techniques, have gained in popularity. Presented here is a detailed study of the performance of some promising alternative algorithms to the stiffness equations approach on high-performance architectures. Implementations of direct and iterative methods for the solution of structural mechanics problems have been made on the Alliant FX/8 and Cray X-MP systems. The direct methods include the classical Cholesky factorization of the stiffness matrices, the natural factor method of Argyris, and a weighted least-squares method with iterative improvement of Van Loan. The iterative methods include new preconditioned conjugate gradient methods for weighted least-squares problems by Freund and for least squares with equality constraints by Barlow, Nichols, and Plemmons. Such alternatives can be, of course, more computation intensive. Thus the need for efficient algorithms for high-speed architectures is apparent. Performance issues discussed here include the speedups obtained for vectorization on a Cray X-MP as well as the speedups for vectorization and concurrency on an Alliant FX/8.
Early tracheostomy for primary airway management in the surgical critical care setting

During a 12-month period, 264 patients with multiple injuries who required mechanical ventilation were admitted to the surgical intensive care unit. One hundred twenty patients (46%) were disengaged from the ventilator, and 38 patients (14%) died. Of the remaining 106 patients (40%) 51 patients (group I) were to receive tracheostomy within 1 to 7 days, and 55 patients (group II) underwent late (8 or more days after admission) tracheostomy. Multiple variables in four categories (admission, operative, ventilatory, and outcome) were analyzed prospectively to define the impact that early tracheostomy had on duration of mechanical ventilation, intensive care stay, and hospital stay. Morbidity and mortality rates of the procedures were assessed. Early tracheostomy, in a homogeneous group of critically ill patients, is associated with a significant decrease in duration of mechanical ventilation, as well as shorter intensive care unit and hospital stays, compared with translaryngeal endotracheal intubation. There were no deaths attributable to tracheostomy, and overall morbidity of the procedures was 4%. We conclude that early tracheostomy has an overall risk equivalent to that of endotracheal intubation. Furthermore, early tracheostomy shortens days on the ventilator and intensive care unit and hospital days and should be considered for patients in the intensive care unit at risk for more than 7 days of intubation.
Aspects of fractional superstrings

We investigate some issues relating to recently proposed fractional superstring theories withDcritical<10. Using the factorization approach of Gepner and Qiu, we systematically rederive the partition functions of theK=4, 8, and 16 theories and examine their spacetime supersymmetry. Generalized GSO projection operators for theK=4 model are found. Uniqueness of the twist field,φK/4K/4, as source of spacetime fermions is demonstrated.
Supersymmetric black holes

Abstract The effective action of d=4, N=2 supergravity is shown to acquire no quantum corrections in background metrics admitting supercovariantly constant spinors. In particular, these metrics include the Robinson-Bertotti metric (product of two two-dimensional spaces of constant curvature) with all eight supersymmetries unbroken. Another example is a set of arbitrary number of extreme Reissner-Nodstrom black holes break four of eight supersymmetries, leaving the other four unbroken. We have found manifestly supersymmetric black holes, which are non-trivial solutions of the flatness condition D2=0 of the corresponding (shortened) superspace. Their bosonic part describes a set of extreme Reissner-Nordstrom black hole solutions are exact even when all quantum supergravity corrections are taken into account.
AN ERROR CORRECTION ANALYSIS OF U.S.-MEXICO TRADE FLOWS

Abstract Estimation of bilateral trade elasticities is less well documented than is the case for aggregate trade flows. This study estimates bilateral trade equations for Mexico and the United States. The empirical analysis is carried out using an error correction approach that allows imports and exports to adjust over time to changes in the independent variables that affect the demand for them. Results obtained indicate that imports and exports between the two neighbors react heterogeneously to variations in domestic prices, foreign prices, and currency values. Lag structures between the two trade equations also differ from each other.
Generalized Konishi anomaly, Seiberg duality and singular effective superpotentials

Using the generalized Konishi anomaly (GKA) equations, we derive the effective superpotential of four-dimensional N = 1 supersymmetric SU(Nc) gauge theory with Nf = Nc + 2 fundamental flavors. We find, however, that the GKA equations are only integrable in the Seiberg dual description of the theory, but not in the direct description of the theory. The failure of integrability in the direct, strongly coupled, description suggests the existence of non-perturbative corrections to the GKA equations.
Catalytic Asymmetric Synthesis of Diarylacetates and 4,4-Diarylbutanoates. A Formal Asymmetric Synthesis of (+)-Sertraline

The intermolecular C−H insertion chemistry of phenyldiazoacetates catalyzed by dirhodium tetrakis((S)-N-(dodecylbenzenesulfonyl)prolinate) (Rh2(S-DOSP)4) can be effectively carried out on cyclohexadienes, leading to the asymmetric synthesis of diarylacetates. The reaction of vinyldiazoacetates with cyclohexadienes results in an unprecedented carbenoid reaction that is formally a combined C−H insertion/Cope rearrangement. The synthetic utility of this novel transformation was demonstrated by its utilization in a formal asymmetric synthesis of (+)-sertraline.
Choosing to keep up with the Joneses and income inequality

We study a variant of the conventional keeping-up-with-the-Joneses setup, in which heterogeneous-ability agents care both about consumption and leisure and receive an utility premium if their consumption exceeds that of the Joneses’. Unlike the conventional setup in which all agents are assumed to want to participate in the rat race of staying ahead of the Joneses, our formulation explicitly permits the option to drop out. Mean-preserving changes in the spread of the underlying ability distribution, via its effect on the economy-wide composition of rat-race participants and drop-outs, have important consequences for induced distributions of leisure and income, consequences that are unobtainable using conventional keeping-up preferences.
Standard modules for tabular algebras

We introduce cell modules for the tabular algebras defined in a previous work; these modules are analogous to the representations arising from left Kazhdan–Lusztig cells. The standard modules of the title are constructed in an elementary way by suitable tensoring of the cell modules. We show how a certain extended affine Hecke algebra of type A equipped with its Kazhdan–Lusztig basis is an example of a tabular algebra, and verify that in this case our standard modules coincide with other standard modules defined in the literature.
Integrated Velocity Model Estimation For Accurate Imaging

Surface seismic reflections, surface seismic direct arrivals, well data and prior geologic information can be used to constrain a subsurface velocity model. These various sources of subsurface velocity information have different strengths and weaknesses. Integrating all available velocity information into a velocity model increases the accuracy of the model by offsetting the weakness of one data type with the strengths of another. We call the process of building a model that integrates all data integrated velocity model estimation.
Unitarity relations in c=1 Liouville theory

We consider the S-matrix of c=1 Liouville theory with vanishing cosmological constant. We examine some of the constraints imposed by unitarity. These completely determine (N,2) amplitudes at tree level in terms of the (N,1) amplitudes when the "plus" tachyon momenta take generic values. A surprising feature of the matrix model results is the lack of particle creation branch cuts in the higher genus amplitudes. In fact, we show that the naive field theory limit of Liouville theory would predict such branch cuts. However, unitarity in the full string theory ensures that such cuts do not appear in genus one (N,1) amplitudes. We conclude with some comments about the genus one (N,2) amplitudes.
Efficient reduction of sulfoxides with 2,6-dihydroxypyridine

Abstract 2,6-Dihydroxypyridine was found to be an efficient reagent in the deoxygenation of sulfoxides. The mild reaction conditions were compatible with functional groups such as ester and carbamate. It was also found that approximately 0.25 equivalents of 2,6-dihydroxypyridine was required for effective reduction.
Copper-catalyzed synthesis of 1,3-enynes.

We report a copper(I)-catalyzed procedure for the synthesis of 1,3-enynes. This method affords a variety of enynes in good to excellent yields. This method can tolerate a variety of functional groups, does not require the use of expensive additives, and is palladium-free.
Spectral response of Cantor multilayers made of materials with negative refractive index

Abstract Whereas Cantor multilayers made of an isotropic dielectric–magnetic material with positive refractive index will show power-law characteristics, low-order Cantor multilayers made of materials with negative refractive index will not exhibit the power-law nature. A reason for this anomalous behavior is presented.
Quasi-efficient revocation of group signatures

Several interesting group signature schemes have been proposed to-date. However, in order for the entire group signature concept to become practical and credible, the problem of secure and efficient group member revocation must be addressed. In this paper, we construct a new revocation method for group signatures based on the signature scheme by Ateniese et al. [ACJT]. This new method represents an advance in the state-of-the-art since the only revocation schemes proposed thus far are either: 1) based on implicit revocation and the use of fixed time periods, or 2) require the signature size to be linear in the number of revoked members. Our method, in contrast, does not rely on time periods, offers constant-length signatures and constant work for the signer.
The fate of dark energy

Abstract By studying the present cosmological data, particularly on CMB, SNeIA and LSS, we find that the future fate of the universe, for simple linear models of the dark energy equation-of-state, can vary between the extremes of (I) a divergence of the scale factor in as little as 7 Gyr; (II) an infinite lifetime of the universe with dark energy dominant for all future time; (III) a disappearing dark energy where the universe asymptotes as t →∞ to a ( t )∼ t 2/3 , i.e., matter domination. Our dreadful conclusion is that no amount of data from our past light-cone can select between these future scenarios.
The 2002 outburst of the black hole X-ray binary 4U 1543-47: Optical and infrared light curves

We obtained simultaneous optical and near-infrared observations of 4U 1543-47 during its 2002 outburst. The most striking feature of the outburst light curve is the secondary maximum, which appears after the object transitions into the low-hard state. This secondary maximum is much stronger in the infrared bands than in the optical. We suggest that the origin of the secondary maximum flux may be synchrotron radiation associated with a jet. Close infrared monitoring may lead to reliable triggers for simultaneous multiwavelength campaigns to study jet formation processes.
Atmospheric variations and meteorite production on Mars

Abstract Through a combination of aerobraking (drag deceleration) and ablation, meteoroids which enter planetary atmospheres may be slowed sufficiently to soft-land as meteorites. Results of an earlier study suggest that the current 6 mbar atmosphere of Mars is sufficient to aerobrake significant numbers of small (
The case for open source appropriate technology

Much of the widespread poverty, environmental desecration, and waste of human life seen around the globe could be prevented by known (to humanity as a whole) technologies, many of which are simply not available to those that need it. This lack of access to critical information for sustainable development is directly responsible for a morally and ethically unacceptable level of human suffering and death. A solution to this general problem is the concept of open source appropriate technology or OSAT, which refers to technologies that provide for sustainable development while being designed in the same fashion as free and open source software. OSAT is made up of technologies that are easily and economically utilized from readily available resources by local communities to meet their needs and must meet the boundary conditions set by environmental, cultural, economic, and educational resource constraints of the local community. This paper explores both the open source and appropriate technology aspects of OSAT to create a paradigm, in which anyone can both learn how to make and use needed technologies free of intellectual property concerns. At the same time, anyone can also add to the collective open source knowledge ecosystem or knowledge commons by contributing ideas, designs, observations, experimental data, deployment logs, etc. It is argued that if OSAT continues to grow and takes hold globally creating a vibrant virtual community to share technology plans and experiences, a new technological revolution built on a dispersed network of innovators working together to create a just sustainable world is possible.
A 'sidewinding' locomotion gait for hyper-redundant robots

This paper considers a novel form of hyper-redundant mobile robot locomotion which is analogous to the 'sidewinding' locomotion gait employed by several species of snake. It is shown that this gait can be generated by a repetitive traveling wave of mechanism deformation. This paper considers primarily the kinematics of the sidewinding gait. The kinematic analysis is based on a continuous 'backbone curve' model which captures the robot's important macroscopic features. Using this continuous model, we first develop algorithms which enable travel in a uniform direction. We subsequently extend this basic gait pattern to enable changes in the direction of travel.
Microstructure-Level Force Prediction Model for Micro-milling of Multi-Phase Materials

A mechanistic model for the micro-endmilling process is developed that explicitly accounts for the different phases while machining heterogeneous materials. It is shown that frequencies in the cutting force signal higher than those that can be explained by the kinematics of the process can be explained by considering the multiple phases in the material. Experiments are performed on two compositions of ductile iron, pure ferrite and pearlite workpieces. These experiments show that the nature of the variation in the ductile iron cutting force signals can be attributed to the mixture of the phases. Additionally, simulation studies show that the frequency component of the variation is related to the spacing of the secondary (ferrite) phase and the magnitude of this component is determined by the size of the secondary phase particles.
The Magnitude, Destinations, and Determinants of Mathematics and Science Teacher Turnover

This study examines the magnitude, destinations, and determinants of mathematics and science teacher turnover. The data are from the nationally representative Schools and Staffing Survey and the Te...
Damage mechanics in the post-failure regime

Abstract A continuum damage model for the deformation of brittle materials, based on the mechanics of microcrack nucleation and growth, is extended to include the effect of interaction among neighboring microcracks on the evolution of damage. As a result, the range of validity of the model is extended to include a limited region of homogeneous softening just beyond the point of maximum stress. With the inclusion of interaction effects, a variety of non-linear, time-dependent behavior can be realistically modeled. Examples of the response of rock subjected to a variety of deformation histories such as constant stress rate loading, creep, and uniaxial strain are presented and the results are compared to experimental results where possible.