cssi/SciSciGPT-SciSciNet huggingface dataset:
A method for the reduction of bluff body drag

Abstract Although several techniques for the reduction of bluff body drag have been proposed in the literature by previous investigators, most of these investigations did not estimate the drag of the entire system consisting of bluff body and drag-reducing device. In the present study, we have devised a method of not only reducing the drag of the bluff body, but reducing the drag of the entire system to values well below that of the bluff body alone. Our method, which utilizes a small flat plate placed upstream of and parallel to the cylinder (with the plate oriented normal to the free stream), has yielded an optimal geometrical configuration consisting of a plate height one-third the cylinder diameter placed 1.5 diameters upstream of the cylinder, and produces a system drag that is 38% that of the bare cylinder alone. The reduction in drag is manifested through two distinct modes of the flow — a cavity mode observed for small values of the plate-cylinder gap, and a wake-impingement mode observed for larger values of this gap. The cavity mode is found to deliver a larger reduction in drag due to a substantial increase in thrust associated with the front surface of the cylinder.
Antibiotic Prophylaxis in Orthopedic Surgery

This review covers four areas: the use of prophylactic antibiotics in orthopedic surgery not involving prosthetic devices; the use of prophylactic antibiotics in prosthetic joint implantation; the use of antibiotic-containing cement in prosthetic joint surgery; and the use of prophylactic antibiotics for dental procedures in individuals with implanted prosthetic joints. The major conclusions are as follows: (1) Prophylactic antimicrobial agents lower the rate of wound infection following surgery for closed hip fractures. (2) Antimicrobial prophylaxis reduces the frequency of deep wound infection following total joint replacement; operating rooms with ultraclean air have a similar effect. (3) Antibiotic-impregnated cement is as effective as systemic antibiotics in preventing early infection following total joint replacement. (4) For routine dental work in most patients with total joint replacement, there is insufficient evidence to support antibiotic prophylaxis; for such individuals with periodontal disease or potential dental infection, antimicrobial prophylaxis seems indicated.
The Zeno argumentation framework

The Zeno Argumentation Framework is a formal model of argumentation based on the informal models of Toulmin and Rittel. Its main feature is a labelling function using arguments to compute heuristic information about the relative quality of the alternative positions proposed as solutions for some practical issue. The Zeno Argumentation Framework was designed to be used in mediation systems, an advanced kind of electronic discussion forum with special support for argumentation, negotiation and other structured forms of group decision-making.
Statistical Entry, Descent, and Landing Performance Reconstruction of the Mars Science Laboratory

The Mars Science Laboratory spacecraft landed an approximately 900 kg rover on Mars on 5 August 2012. Similar to past Mars missions, the spacecraft recorded inertial measurement unit data and radar altimeter measurements, but its aeroshell was also instrumented with flush atmospheric data system sensors that captured the pressure distribution on the vehicle during hypersonic and supersonic flight regimes. The rich data set enables a comprehensive postflight analysis of the vehicle’s trajectory, atmosphere, and aerodynamics. This paper demonstrates a comprehensive statistical estimation methodology and applies it to the large but disparate data set to reconstruct the vehicle’s entry performance, while using several statistical estimation methods, specifically the extended Kalman filter, unscented Kalman filter, and adaptive filter, which concurrently estimate both the state and the uncertainties. The results of the analysis shows good agreement between the estimated states, preflight predictions, and indep...
New Charged Dilaton Solutions in 2+1 Dimensions and Solutions with Cylindrical Symmetry in 3+1 Dimensions

We report a new family of solutions to Einstein-Maxwell-dilaton gravity in 2+1 dimensions and Einstein-Maxwell gravity with cylindrical symmetry in 3+1 dimensions. A set of static charged solutions in 2+1 dimensions are obtained by a compactification of charged solutions in 3+1 dimensions with cylindrical symmetry. These solutions contain naked singularities for certain values of the parameters considered. New rotating charged solutions in 2+1 dimensions and 3+1 dimensions are generated treating the static charged solutions as seed metrics and performing SL(2;R) transformations.
Intramolecular diamination and alkoxyamination of alkenes with N-sulfonyl ureas employing N-iodosuccinimide

Reaction of N-δ-alkenyl-N'-sulfonyl urea 1 with N-iodosuccinimde (NIS; 2 equiv) and a catalytic amount of AgOTf (20 mol %) at room temperature led to intramolecular alkoxyamination to form bicyclic isourea 2a in 95% isolated yield. In comparison, reaction of 1 with NIS and sodium bicarbonate (1 equiv) at room temperature led to isolation of bicyclic imidazolidin-2-one 2b in 91% yield. These NIS-mediated alkoxyamination and diamination protocols were effective for a range of N-δ-alkenyl-N'-sulfonyl ureas to form the corresponding heterobicyclic compounds in good yield with high chemoselectivity and good to excellent diastereoselectivity.
Alternative strategies for controlling rising cesarean section rates

Cesarean section rates in the United States have increased from 5.5% in 1970 to 24.4% in 1987. This dramatic increase has generated considerable concern, leading to a variety of proposals to control rising use of cesarean section. Six strategies have been adopted or proposed to reduce cesarean section use: (1) education and peer evaluation, (2) external review, (3) public dissemination of cesarean section rates, (4) changes in physician payment, (5) changes in hospital payment, and (6) medical malpractice reform. These strategies differ in their specific assumptions regarding the process of clinical decision making, implications for physician autonomy, and methods of implementation. Educational efforts have been the most widely promoted. Of these, formal programs aimed at modifying practices within individual hospitals appear to be the most successful. However, insufficient research has been conducted to compare conclusively the impact and feasibility of these six strategies, pointing to the need for further study. (JAMA. 1990;263:683-687)
Exciton kinetics in poly(di-n-hexylsilane)

Abstract We have previously shown that charge carriers are generated by exciton-exciton annihilation in solid films of poly(di-n-hexylsilane). Using this phenomenon we show that the exciton-exciton annihilation rate constant γ at ambient temperature is not a function of the photon energy used to create the excitons even at energies well out into the long wavelength tail of the exciton absorption band. We also show that the excitons remain highly mobile throughout their 600 ps lifetime and that they diffuse distance comparable to the crystallite size in the film. The value of γ obtained in these studies is in excellent agreement with that obtained previously in fluorescence intensity studies.
Do Donors Discount Low-Quality Accounting Information?

ABSTRACT: Prior research finds that donors reward nonprofits that report larger program ratios with more donations and that program ratios frequently are subject to intentional manipulation as well as unintentional errors. We examine how donors react to low-quality ratios. We find that the average donor discounts ratios that are inflated by only the simplest and most observable of methods. We then examine the effect of financial data availability on the average donor's ability to unravel inflated ratios by using the historical shift in data availability that occurred in 1997 and 1998. We find that donors began to discount ratios only after 1998. Finally, we examine whether the discount applied to program ratios varies across donor sophistication (measured as the percentage of fund balances with restrictions) and find that sophisticated donors apply incrementally larger discounts to inflated ratios and discount ratios that are inflated by more complex methods. JEL Classifications: G1; G18; G3; G38; L3; L30...
A cycloaddition strategy directed toward the spiro ring system of the ginkgolides

Abstract A diastereocontrolled [3+2] cycloaddition to a sterically congested γ-alkoxy-β,β-disubstituted-α,β-unsaturated sulfone combined with a thiomethylenation of an enol silyl ether provides the core spirocarbocyclic rings of the ginkgolides.
Numerical Analysis of a Vortex Controlled Diffuser

A numerical study of a prototypical vortex controlled diffuser is performed. The basic diffuser geometry consists of a step expansion in a pipe of area ratio 2.25:1. The incompressible Reynolds averaged Navier-Stokes equations, employing the RNG based K − e turbulence model, are solved. Results are presented for bleed rates ranging from 1 to 7 percent. Diffuser efficiencies in excess of 80 percent were obtained. These results are in good qualitative agreement with previous experimental work. The results do not confirm previous suggestions that the increases in effectiveness of the VCD over a step expansion result from an inhibition of flow separation due to the generation and downstream convection of extremely high levels of turbulence generated in the region of the bleed gap. The results do indicate that the effectiveness of the diffuser is a consequence of the turning of the flow toward the outer wall due to the influence of the low pressure vortex chamber. Calculations employing the RNG based turbulence model were able to capture the abrupt increase in diffuser effectiveness that has been shown experimentally to occur at low bleed rates. Calculations employing the standard K - e model were unable to predict this occurrence
Reaction kinetics and kinetic processes in modern liquid chromatographic reactors

Abstract The analysis and use of liquid chromatographic columns as chemical reactors are explained. Multifold applications of liquid chromatographic reactors with a wide range of materials are described and illustrated. Means for extracting chemical kinetic rate data from liquid chromatographic reactor experiments in the presence of other dynamic processes are emphasized. Techniques for controlling reactivity and selectivity are explained. It is also shown that useful information about the stationary phase and protein interaction with the stationary phase can be accessible from these experiments. Several explanations for multiple zone formation including results from interconversion studies are presented. It appears that a broader awareness of chromatographic reactor applications would be beneficial to workers in a variety of different fields. There are a number of additional possibilities for the future including the removal and detoxification through transformation of environmentally undesirable materials.
Evaluation of factors controlling long-range transport of black carbon to the Arctic

[1] This study evaluates the sensitivity of long-range transport of black carbon (BC) from midlatitude and high-latitude source regions to the Arctic to aging, dry deposition, and wet removal processes using the Geophysical Fluid Dynamics Laboratory (GFDL) coupled chemistry and climate model (AM3). We derive a simple parameterization for BC aging (i.e., coating with soluble materials) which allows the rate of aging to vary diurnally and seasonally. Slow aging during winter permits BC to remain largely hydrophobic throughout transport from midlatitude source regions to the Arctic. In addition, we apply surface-dependent dry deposition velocities and reduce the wet removal efficiency of BC in ice clouds. The inclusion of the above parameterizations significantly improves simulated magnitude, seasonal cycle, and vertical profile of BC over the Arctic compared with those in the base model configuration. In particular, wintertime concentrations of BC in the Arctic are increased by a factor of 100 throughout the tropospheric column. On the basis of sensitivity tests involving each process, we find that the transport of BC to the Arctic is a synergistic process. A comprehensive understanding of microphysics and chemistry related to aging, dry and wet removal processes is thus essential to the simulation of BC concentrations over the Arctic.
The Sensitivity of Capital Use to Price in Higher Education

We test whether U.S. colleges and universities adjust their physical capital intensity to differences in factor prices by regressing the square feet of space per student on construction prices across institutions. The results indicate that physical space at selective liberal arts colleges and private comprehensive universities is unresponsive to relative factor prices but do reflect differences in institutional wealth. At public comprehensive universities and two-year colleges the evidence suggests that students enjoy more space per student where building costs are lower.
Financial Innovation and the Role of Derivative Securities: An Empirical Analysis of the Treasury STRIPS Program

The role that financial innovation plays in financial markets is very controversial. To provide insight into this role, we examine how market participants use the highly successful Treasury STRIPS program. We find that investors use the option to create Treasury-derivative STRIPS primarily to make markets more complete and take advantage of tax and accounting asymmetries. Although liquidity-related factors help explain differences in the prices of Treasury bonds and STRIPS, we find little evidence that the option to strip and reconstitute securities is used for speculative or arbitrage-related purposes. THE ROLE OF FINANCIAL INNOVATION is a central issue for both policymakers and researchers in finance.1 Critics argue that financial innovations often have no economic role beyond allowing some investors to take highly leveraged speculative or arbitrage-related positions. In contrast, advocates argue that the introduction of new products makes financial markets more complete, reduces frictions and transaction costs, and leads to a more optimal allocation of risk in the economy. To better understand the role played by financial innovation, this paper examines how investors use the successful Separate Trading of Registered Interest and Principal of Securities (STRIPS) program of the U.S. Treasury. This program allows investors to strip Treasury notes and bonds to create separate discount bonds, and to reconstitute previously stripped notes and
Gauge fields and D-branes

Abstract We prove that self-dual gauge fields in type I superstring theory are equivalent to configurations of Dirichlet 5-branes, by showing that the world-sheet theory of a Dirichlet 1-brane moving in a background of 5-branes includes an “ADHM sigma model”. This provides an explicit construction of the equivalent self-dual gauge field. We also discuss type II.
Production of ultrashort FEL XUV pulses via a reverse undulator taper

Abstract We adapt the “reverse taper” scheme presented by Saldin et al. (Phys. Rev. ST Accel. Beams 9 (2006) 050702) for attosecond pulse production to the XUV/soft-X-ray regime. We find that GW-level pulses of a few femtosecond duration or shorter can be produced using electron beams of quite moderate parameters and undulators of 20-m length or shorter. The output pulse is significantly shifted in wavelength relative to the main background which permits a further increase in contrast ratio via simple monochromatization. Moreover, the output pulse has a natural wavelength chirp that allows further temporal compression, if wanted. Both positive and negative chirps can be produced depending upon the sign of the undulator taper.
Historic District Influence on House Prices and Marketing Duration

Historic property designations have been lauded for spurring renovation beyond the historic structures themselves through positive externalities in surrounding neighborhoods. Previous historic district research focuses on whether historic designation results in a price premium. This paper takes a more comprehensive look at the buying process, which must consider marketing duration within the historic district as well as influences on the sale of properties adjacent to the historic district. We examine how historic district designation in Baton Rogue, Louisiana is capitalized either through a price premium or marketing duration and how that mechanism differs between neighborhoods inside and outside the historic district boundaries. We employ a three stage least square, 3SLS, model to account for the effects of endogenous marketing duration on price capitalization estimates. The estimates are consistent with search-market theory in that marketing duration absorbs part of the capitalization of historic designation. We find that the more certain benefits from historic designation within the district are reflected in a price premium while the reduced regulation coupled with the cachet of being located near but not inside the district result in shorter marketing duration.
Interferon Tau: A Novel Pregnancy Recognition Signal

PROBLEM: Trophectoderm of ruminant conceptuses (embryo and associated membranes) secretes tau interferons (IFNτ) as the pregnancy recognition signal. How does it act? METHOD: Review of current data. RESULTS: IFNt acts on uterine epithelium to suppress transcription of the genes for estrogen receptor and oxytocin receptor. This blocks development of the uterine luteolytic mechanism and, therefore, release of luteolytic pulses of prostaglandin F 2α , but it has no effect on expression of the progesterone receptor. Maintenance of progesterone secretion by the corpus luteum ensures establishment and maintenance of pregnancy. Secretion of IFNτ on days 12-15 for sheep and days 14-17 for cows and goats is essential for pregnancy recognition. CONCLUSION: We propose that IFNτ affects endometrial gene expression by activating the Jak/Stat pathway, which results in formation of the ISGF3α transcription factor complex. ISGF3α binds to interferon-stimulated response elements and activates transcription of interferon-responsive genes such as interferon regulatory factor-1 (IRF-1) which, in turn, activates expression of the negative-acting transcription factor IRF-2. Pregnancy (or intrauterine injection of roIFNτ) results in a transient increase in endometrial IRF-1 expression followed 36-48 hr later by a sustained increase in IRF-2. We propose that IRF-2, or an IFNτ-induced negative regulatory factor like IRF-2, suppresses expression of the estrogen receptor gene and directly or indirectly blocks expression of the gene for oxytocin receptor to abrogate the uterine luteolytic mechanism and ensure the establishment of pregnancy.
Lidar method of measurement of atmospheric extinction and ozone profiles.

A description of a method of measurement of atmospheric extinction and of ozone profiles by use of the backscatter signal from a monostatic lidar is given. The central feature of the procedure involves a measurement of the ratio of the Raman backscatter returns of both the oxygen and nitrogen atmospheric content. Because the ratio of the number density of both species is known to high accuracy, the measurement itself becomes a measure of the ratio of two transmissions to altitude along with a ratio of the two system constants. The calibration measurement for determining the value of the ratio of the two system constants or electro-optical conversion constants is accomplished by a lidar measurement of identical atmospheric targets while at the same time interchanging the two optical filters in the two optical channels of the receiver. More details of the procedure are discussed. Factoring this calibrated value into the measured O2/N2 profile ratio provides a measured value of the ratio of the two transmissions. Or equivalently, it provides a measurement of the difference of the two extinction coefficients at the O2 and N2 Raman wavelengths as a function of the height.
ANGULAR MOMENTUM TRANSPORT IN PROTOPLANETARY AND BLACK HOLE ACCRETION DISKS: THE ROLE OF PARASITIC MODES IN THE SATURATION OF MHD TURBULENCE

The magnetorotational instability (MRI) is considered a key process for driving efficient angular momentum transport in astrophysical disks. Understanding its nonlinear saturation constitutes a fundamental problem in modern accretion disk theory. The large dynamical range in physical conditions in accretion disks makes it challenging to address this problem only with numerical simulations. We analyze the concept that (secondary) parasitic instabilities are responsible for the saturation of the MRI. Our approach enables us to explore dissipative regimes that are relevant to astrophysical and laboratory conditions that lie beyond the regime accessible to current numerical simulations. We calculate the spectrum and physical structure of parasitic modes that feed off the fastest, exact (primary) MRI mode when its amplitude is such that the fastest parasitic mode grows as fast as the MRI. We argue that this saturation amplitude provides an estimate of the magnetic field that can be generated by the MRI before the secondary instabilities suppress its growth significantly. Recent works suggest that the saturation amplitude of the MRI depends mainly on the magnetic Prandtl number. Our results suggest that, as long as viscous effects do not dominate the fluid dynamics, the saturation level of the MRI depends only on the Elsasser number Λη. We calculate the ratio between the stress and the magnetic energy density, αsatβsat, associated with the primary MRI mode. We find that for Ληgt;1 Kelvin-Helmholtz modes are responsible for saturation and αsatβsat = 0.4, while for Λη < 1 tearing modes prevail and αsatβsat 0.5 Λη. Several features of numerical simulations designed to address the saturation of the MRI in accretion disks surrounding young stars and compact objects can be interpreted in terms of our findings.
Structure and complexity of relational queries

Abstract This paper is an attempt at laying the foundations for the classification of queries on relational data bases according to their structure and their computational complexity. Using the operations of composition and fixpoints, a Σ-π hierarchy of height ω2, called the fixpoint query hierarchy, is defined, and its properties investigated. The hierarchy includes most of the queries considered in the literature including those of Codd and Aho and Ullman. The hierarchy to level ω characterizes the first-order queries, and the levels up to ω are shown to be strict. Sets of queries larger than the fixpoint query hierarchy are obtained by considered the queries computable in polynomial time, queries computable in polynomial space, etc. It is shown that classes of queries defined from such complexity classes behave (with respect to containment) in a manner very similar to the corresponding complexity classes. Also, the set of second-order queries turns out to be the same as the set of queries defined from the polynomial-time hierarchy. Finally, these classes of queries are used to analyse a set of queries defined from language considerations: those expressible in a programming language with only typed (or ranked) relation variables.
Measurement of synchrotron pulse durations using surface photovoltage transients

Abstract We report results on experiments using combined laser and synchrotron radiation. Picosecond laser pulses at 800 nm are used to induce surface photovoltage transients in p-type Si samples. A two-component decay is observed. The fast component of decay provides a direct measure of synchrotron soft X-ray pulse durations.
Synthesis of β-heteroaryl propionates via trapping of carbocations with π-nucleophiles

A variety of heterocyclic alcohols and acetates were coupled with silyl ketene acetals and other π-nucleophiles in the presence of trimethylsilyl trifluoromethanesulfonate to provide an array of substituted β-heteroaryl propionates, including those with contiguous quaternary centers, as well as vinylogs thereof. This reaction also proceeds with high diastereoselectivity when the π-nucleophile bears a chiral auxiliary.
A class of sheaves satisfying Kodaira's vanishing theorem

This paper contains a Kawamata-Viehweg-Koll\'ar type vanishing theorem for vector bundles. In order to formulate and prove this cleanly, we introduce a class of sheaves that automatically satisfies a vanishing theorem. This is obtained by closing up the subclass of sheaves of adjoint type under extensions, direct images, and taking direct summands.
Convenient synthesis, properties and the structure of tetramethylammonium tris(pyrimidine-2-thiolato)ferrate(II): an iron complex with three stable four-membered N,S-chelate rings

Abstract Reaction of iron(II) chloride with sodium pyrimidine-2-thiolate in ethanol or methanol followed by addition of R4NBr affords (R4N)[Fe(SC4H3N2)3] (R = Me, Et) in high yields. (Me4N)[Fe(SC4H3N2)3] crystallizes in the triclinic space group P 1 with a = 7.163(2), b = 10.002(3), c = 15.456(3) A, α = 103.23(1)°, β = 91.25(1)°, γ = 92.09(1)° and Z = 2. The structure was refined to R = 2.9% on the basis of 5663 unique data (Fo2>2.5σ(Fo2)). The octahedral geometry about iron is highly distorted due to the presence of three four-membered chelate rings with an exceptionally small bite angle of ca. 67°. Average FeN and FeS distance are 2.163 and 2.529 A respectively. The complex is isolated as the mer isomer. Mossbauer studies in polycrystalline state together with UVVis and magnetic susceptibility measurement in acetonitrile solution demonstrate that the iron is in +2 oxidation state with a high-spin electronic configuration.
Social Visibility and the Gifting of Digital Goods

One of the defining features of online social networks is that users' actions are visible to other users. In this paper, we argue that such social visibility has a detrimental effect on users' willingness to gift digital goods. The gift giving process often generates substantial anxiety, and social visibility exacerbates this anxiety to the point that it can deter gifting altogether. To study the effect of social visibility on the decision to gift, we analyze a unique dataset from a large online social network that offers users the option of buying a digital gifting service. We find that purchase rates of the service increased with the number of social ties that users kept on the network, but decreased with the extent to which those ties were tied to each other. We argue that the latter effect is due to the fact that, when a user's ties are tied themselves, any gift sent between the user and one tie is visible to their mutual contacts. This argument is bolstered by a stronger negative effect of social visibility for users with larger, less intimate, and categorically diverse networks.
Single Close Encounters Do Not Make Eccentric Planetary Orbits

The recent discovery of a planet in an orbit with eccentricity e = 0.63 +/- 0.08 around the solar-type star 16 Cyg B, together with earlier discoveries of other planets in orbits of significant eccentricity, raises the question of the origin of these orbits, so unlike the nearly circular orbits of our solar system. In this paper I consider close encounters between two planets, each initially in a nearly circular orbit (but with sufficient eccentricity to permit the encounter). Such encounters are described by a two-body approximation, in which the effect of the attracting star is neglected, and by the approximation that their separation vector follows a nearly parabolic path. A single encounter cannot produce the present state of these systems, in which one planet is in an eccentric orbit and the other has apparently been lost. Even if the requirement that the second planet be lost is dropped, nearly circular orbits cannot scatter into eccentric ones.
Interaction of conduction and radiation in anisotropically scattering, spherical media

Steady-state heat transfer by simultaneous conduction and radiation in absorbing, emitting, linear anisotropically scattering spherical media occupying the region 0 £ r R is analyzed. The medium, which contains continuous heat-generating sources, is confined within a gray, diffuse spherical boundary. To obtain a rigorous solution to the nonlinear heat-transfer problem, the integral form of the equation of transfer is utilized. This integral form is solved in a highly accurate manner by first expanding the unknown functions in power series and then employing the Galerkin method for generating a system of linear algebraic equations, which is then solved by standard methods. The energy equation for the temperature is discretized according to a standard finite-difference approach, and the resulting nonlinear system of equations is linearized utilizing the Newton-Raphson method and solved iteratively by standard routines. A comprehensive parametric study is performed in order to examine the interaction between the radiation and conduction.
Three political realities in expanding coverage for the working poor: one state's experience.

In recent years, states have experimented with innovative approaches to expand coverage for underserved persons. Yet lack of health insurance among low income workers remains a problem. A 1997 survey reported that more than half of adults in low income, working families have been uninsured sometime in the previous two years. This group is likely to increase in the future as states implement time-limited welfare benefits and if employer-sponsored health coverage continues to decrease as in recent years. This paper describes the bipartisan effort of the Indiana Commission on Health Care for the Working Poor to design coverage expansions for uninsured, low income workers and families in Indiana. Initially, legislators challenged the state's insurance industry to develop a private health insurance plan that the state might subsidize to make it affordable to low income workers and/or their employers. However, based on findings from Indiana focus groups of working poor that the Commission conducted, the Commission recommended strategies to mobilize existing safety net providers into networks to provide comprehensive and coordinated care to low income workers and families in designated service areas. Specifically, the state would pay direct subsidies for primary and preventive care to community health centers that participate in networks with safety net hospitals. Also, the state would establish a state-sponsored stop loss fund to protect network hospitals against expenses incurred in the care of catastrophically ill network clients. These strategies reflect three realities that face states as they craft health coverage expansions for uninsured low income workers and families in today's health policy environment. First, in a conservative state, policy makers are unwilling to pay the cost of even limited coverage for low income workers and families. Second, the uninsured poor already obtain care from safety net providers that are programmatically constituted and ideologically committed to serve them. Third, this lack of demand for health coverage with minimum benefits threatens voluntary participation in a subsidized private program. The findings of the focus groups confirmed that, unless heavily subsidized, it is unlikely that low income workers are going to purchase even heavily subsidized health insurance to finance their health care. Given the constraints of the day, addressing the need for health coverage for the remaining uninsured calls for innovative thinking beyond conventional paradigms. Direct subsidies for community health centers and subsidized stop loss protection for safety net hospitals to facilitate the development of networks are promising strategies for extending coverage to uninsured, low income workers and families. While not a substitute for enrollment in a fully-paid health plan, these strategies do promise real improvement in access to high quality health care services for this group of vulnerable Americans.
THE BLACK HOLE MASS DISTRIBUTION IN THE GALAXY

We use dynamical mass measurements of 16 black holes in transient low-mass X-ray binaries to infer the stellar black hole mass distribution in the parent population. We find that the observations are best described by a narrow mass distribution at 7.8 {+-} 1.2 M{sub sun}. We identify a selection effect related to the choice of targets for optical follow-ups that results in a flux-limited sample. We demonstrate, however, that this selection effect does not introduce a bias in the observed distribution and cannot explain the absence of black holes in the 2-5 M{sub sun} mass range. On the high-mass end, we argue that the rapid decline in the inferred distribution may be the result of the particular evolutionary channel followed by low-mass X-ray binaries. This is consistent with the presence of high-mass black holes in the persistent, high-mass X-ray binary sources. If the paucity of low-mass black holes is caused by a sudden decrease of the supernova explosion energy with increasing progenitor mass, this would have observable implications for ongoing transient surveys that target core-collapse supernovae. Our results also have significant implications for the calculation of event rates from the coalescence of black hole binaries for gravitational wave detectors.
On the Conversion Between Number Systems

This brief revisits the problem of conversion between number systems and asks the following question: given a nonnegative decimal number d, what is the value of the digit at position j in the corresponding base b number? Thus, we do not require the knowledge of other digits except the one we are interested in. Accordingly, we present a conversion function that relates each digit in a base b system to the decimal value that is equal to the base b number in question. We also show some applications of this new algorithm in the areas of parallel computing and cryptography
The connection between maternal employment and childhood obesity: Inspecting the mechanisms

This paper investigates the channels through which maternal employment affects childhood obesity. We use time diaries and interview responses from the Child Development Supplement of the Panel Study of Income Dynamics which combines information on children’s time allocation, children’s BMI, and mother’s labor force participation. We find some evidence that supervision and nutrition play significant but small roles in the relationship between maternal employment and childhood obesity. Although the difference in the effect of maternal employment varies by mother’s education, we find few differences in the mechanisms by mother’s education.
Long-chain (polyfluoroalkyl)oxacarbenes

Abstract 3-Chloro-3-(1 H ,1 H )-pentadecafluorooctoxy)diazirine ( 7a ) and 3,3-bis(1 H ,1 H -pentadecafluorooctoxy)diazirine ( 8 ) have been prepared via several steps from 1H,1H- pentadecafluorooctanol ( 3 ) . Photolysis or thermolysis of these diazirines generated the corresponding carbenes ( 1 or 2 ), which underwent intermolecular reactions with HCl, alcohol 3 and acrylonitrile.
Generation of tunable laser sidebands in the far‐infrared region

Continuously tunable laser sidebands have been generated by mixing radiation from an optically pumped far infrared (FIR) molecular laser, operated at 693, 762, 1627, and 1839 GHz, with that from millimeter‐wave klystrons in a Schottky‐barrier diode. An enhancement in conversion efficiency over similar systems reported previously is obtained by using a Michelson interferometer to separate the sidebands from the carrier and by placing the Schottky diode in an open structure corner cube mount. With 4 mW of laser power at 693 and 762 GHz the sideband power was measured to be 3.0 μW. This is at least an order of magnitude better than the previously reported results. At higher frequencies, 22 mW of 1627‐GHz laser power produced about 2.5 μW of sideband output, while 3mW of 1839‐GHz laser power generated about 100 nW of sideband radiation. The lower efficiency at the higher frequencies is due primarily to the mismatch between the laser radiation and the fixed‐length diode antenna. To demonstrate the tunability of the generated far‐infrared radiation, the laser sidebands were swept through absorption lines of HDO and H_2CO near 600 and 800 GHz. The absorption signals were easily seen, using either video or lock‐in detection techniques.
Economic structure, policy objectives, and optimal interest rate policy at low inflation rates

Abstract In this article, the optimal interest-rate rule generated by Svensson’s (1997) dynamic model is used to determine the impact of a number of key structural characteristics on the downward flexibility of interest rates at low rates of inflation. The potential impact of preferences for inflation stability, relative to output stability on the monetary authority’s ability to use expansionary interest-rate policy is also considered. Estimates of the model for six countries provide evidence of the quantitative significance of the theoretical results. The empirical results are used to identify which monetary authorities are likely to be the most severely constrained in the event of an economic downturn. The size of the contraction that would be required for the interest-rate constraint to bind is estimated for each country in the sample.
Issues in M(atrix) theory compactification

We discuss issues concerning M(atrix) theory compactifications on curved spaces. We argue from the form of the graviton propagator on curved space that excited string states do not decouple from the annulus D0-brane υ^4 amplitude, unlike the flat space case. This argurment shows that a large class of quantum mechanical systems with a finite number of degrees of freedom cannot reproduce supergravity answers. We discuss the specific example of an ALE space and suggest sources of possible higher derivative terms that might help reproduce supergravity results.
Interplay between Size and Electronic Effects in Determining the Homogeneity Range of the A9Zn4+xPn9 and A9Cd4+xPn9 Phases (0 ≤ x ≤ 0.5), A = Ca, Sr, Yb, Eu; Pn = Sb, Bi

Seven cadmium- and zinc-containing Zintl phases, A9Zn(4+x)Pn9 and A9Cd(4+x)Pn9 (0 < or = x < or = 0.5), A = Ca, Sr, Yb, Eu; Pn = Sb, Bi, have been synthesized, and their structures have been determined by single-crystal X-ray diffraction. All compounds are isostructural and crystallize in the centrosymmetric orthorhombic space group Pbam (no. 55, Z = 2), and their structures feature tetrahedra of the pnicogens, centered by the transition metal. The tetrahedra are not isolated but are connected through corner sharing to form ribbons, which are separated by the divalent cations. The occurrence of a small phase width and its variation across this family of compounds has been systematically studied by variable temperature crystallography, resistivity, and magnetic susceptibility measurements, and these results have been reconciled with electronic structure calculations performed using the tight-binding linear muffin-tin orbital (TB-LMTO-ASA) method. These analyses of the crystal and electronic structure indicate that the polyanionic subnetwork requires 19 additional electrons, whereas only 18 electrons are provided by the cations. Such apparent "electron deficiency" necessitates the presence of an interstitial atom in order for an optimal bonding to be achieved; however, an interplay between the sizes of the cations and anions and the total valence electron concentration (governed by the stoichiometry breadth) is suggested as a possible mechanism for achieving structure stability. The structural relationship between these and some known structures with two-dimensional layers are discussed as well.
Minimal size of basic families

Abstract A family Φ of continuous real-valued functions on a space X is said to be basic if every f ∈ C ( X ) can be represented f = ∑ i = 1 n g i ∘ ϕ i for some ϕ i ∈ Φ and g i ∈ C ( R ) ( i = 1 , … , n ). Define basic ( X ) = min { | Φ | : Φ is a basic family for X } . If X is separable metrizable then either X is locally compact and finite-dimensional, and basic ( X ) ℵ 0 , or basic ( X ) = c . If K is compact and finite-dimensional then basic ( K ) ⩽ cof ( [ w ( K ) ] ℵ 0 , ⊆ ) , and if K contains a discrete subset D with | D | = w ( K ) , then either K is finite-dimensional, and basic ( K ) = cof ( [ w ( K ) ] ℵ 0 , ⊆ ) or basic ( K ) = | C ( K ) | = w ( K ) ℵ 0 .
Dnase2a Deficiency Uncovers Lysosomal Clearance of Damaged Nuclear DNA via Autophagy

Deficiencies in DNA-degrading nucleases lead to accumulation of self DNA and induction of autoimmunity in mice and in monogenic and polygenic human diseases. However, the sources of DNA and the mechanisms that trigger immunity remain unclear. We analyzed mice deficient for the lysosomal nuclease Dnase2a and observed elevated levels of undegraded DNA in both phagocytic and nonphagocytic cells. In nonphagocytic cells, the excess DNA originated from damaged DNA in the nucleus based on colocalization studies, live-cell imaging, and exacerbation by DNA-damaging agents. Removal of damaged DNA by Dnase2a required nuclear export and autophagy-mediated delivery of the DNA to lysosomes. Finally, DNA was found to accumulate in Dnase2a(-/-) or autophagy-deficient cells and induce inflammation via the Sting cytosolic DNA-sensing pathway. Our results reveal a cell-autonomous process for removal of damaged nuclear DNA with implications for conditions with elevated DNA damage, such as inflammation, cancer, and chemotherapy.
Quantitative phase contrast imaging of THz electric fields in a dielectric waveguide.

We apply phase contrast imaging to enable, sharply focused visualization of terahertz waves in electro-optic media. The approach allows quantitative characterization of THz waves in the 60 GHz – 4.5 THz frequency range in a thin dielectric slab and in-focus observation of THz waves in polaritonic structures.
Impact of Next-Generation Synchrotron Radiation Sources on Materials Research

Abstract Three generations of synchrotron radiation sources have revolutionized our understanding of various correlations in the equilibrium phase of materials through X-ray imaging, spectroscopy and scattering techniques. It is anticipated that new sources based on energy-recovery linacs and X-ray free-electron lasers will deliver X-ray pulses that are below a few-hundred femtoseconds in length and have very high coherence. These sources will extend and broaden our current knowledge of materials science. But more importantly, it is expected that these sources will provide the first glimpse of nonequilibrium processes in materials, including nonthermal melting, metal–insulator transitions involving nonequilibrium phases, laser-induced catalytic oxidation, and determining the structure of imperfect nanoparticles lacking crystalline structure.
Nonlinear Deformation Behavior of Bolted Flanges Under Tensile, Torsional, and Bending Loads

This paper investigates the nonlinear deformation behavior of bolted flanges under tensile, torsional and bending loads, using Finite Element Analysis (FEA). Even though the bolted flange may still deform elastically, the variation in contact area due to the external loading will cause nonlinear deformation. In this study, finite element simulation is used for investigating the respective non-linear deformation behavior of a preloaded bolted flange under tensile, torsional and bending loads, and to determine the corresponding stiffness values for each loading.Copyright © 2010 by ASME
The first discovery of a wide binary brown dwarf

I present observations of a new faint double, 2MASS J11011926-7732383AB, toward the Chamaeleon I star-forming region. From optical and near-infrared images of the pair, I measure a separation of 144 and extract RIJHKs photometry of the components (IA = 17.21, ΔI = 1.07, Ks,A = 11.97, ΔKs = 0.84). I use resolved optical spectroscopy to derive spectral types of M7.25 and M8.25 for the A and B components, respectively. Based on the strengths of gravity-sensitive features in these data, such as the Na I and K I absorption lines, I conclude that these objects are young members of Chamaeleon I rather than field stars. The probability that this pair is composed of unrelated late-type members of Chamaeleon I is low enough (~5 × 10-5) to definitively establish it as a binary system. After estimating extinctions, effective temperatures, and bolometric luminosities for the binary components, I place them on the H-R diagram and infer their masses with the evolutionary models of Chabrier and Baraffe, arriving at substellar values of 0.05 and 0.025 M☉. The projected angular separation of this system corresponds to 240 AU at the distance of Chamaeleon I, making it the first known binary brown dwarf with a separation greater than 20 AU. This demonstration that brown dwarfs can form in fragile, easily disrupted configurations is direct evidence that the formation of brown dwarfs does not require ejection from multiple systems or other dynamical effects. It remains possible that ejection plays a role in the formation of some brown dwarfs, but it is not an essential component according to these observations.
Inhibition of Oleamide Hydrolase Catalyzed Hydrolysis of the Endogenous Sleep-Inducing Lipid cis-9-Octadecenamide

Oleamide (1, cis-9-octadecenamide) is a naturally occurring brain constituent that has been shown to accumulate and disappear under conditions of sleep deprivation and sleep recovery, respectively. Synthetic 1 has been found to induce sleep in a structurally specific manner at nanomolar quantities. Hydrolysis of 1 by an enzyme (oleamide hydrolase) present in the cell membrane rapidly degrades oleamide to oleic acid (cis-9-octadecenoic acid). Such observations suggest 1 may constitute a prototypical member of a class of fatty acid primary amide biological signaling molecules in which the diversity and selectivity of function are derived from the length of the alkane chain as well as the position, stereochemistry, and degree of unsaturation. A series of inhibitors of oleamide hydrolase were designed and prepared which were expected to derive their properties through interactions with the putative active site cysteine residue within oleamide hydrolase. This approach yielded a series of rapid, selective, and ...
Transport and equilibrium uptake of a peptide inhibitor of PACE4 into articular cartilage is dominated by electrostatic interactions.

Abstract The availability of therapeutic molecules to targets within cartilage depends on transport through the avascular matrix. We studied equilibrium partitioning and non-equilibrium transport into cartilage of Pf-pep, a 760 Da positively charged peptide inhibitor of the proprotein convertase PACE4. Competitive binding measurements revealed negligible binding of Pf-pep to sites within cartilage. Uptake of Pf-pep depended on glycosaminoglycan charge density, and was consistent with predictions of Donnan equilibrium given the known charge of Pf-pep. In separate transport experiments, the diffusivity of Pf-pep in cartilage was measured to be ∼1 × 10−6 cm2/s, close to other similarly-sized non-binding solutes. These results suggest that small positively charged therapeutics will have a higher concentration within cartilage than in the surrounding synovial fluid, a desired property for local delivery; however, such therapeutics may rapidly diffuse out of cartilage unless there is additional specific binding to intra-tissue substrates that can maintain enhanced intra-tissue concentration for local delivery.