cssi/SciSciGPT-SciSciNet huggingface dataset:
X-raying galaxies: A Chandra legacy

This presentation reviews Chandra’s major contribution to the understanding of nearby galaxies. After a brief summary on significant advances in characterizing various types of discrete x-ray sources, the presentation focuses on the global hot gas in and around galaxies, especially normal ones like our own. The hot gas is a product of stellar and active galactic nuclear feedback—the least understood part in theories of galaxy formation and evolution. Chandra observations have led to the first characterization of the spatial, thermal, chemical, and kinetic properties of the gas in our galaxy. The gas is concentrated around the galactic bulge and disk on scales of a few kiloparsec. The column density of chemically enriched hot gas on larger scales is at least an order magnitude smaller, indicating that it may not account for the bulk of the missing baryon matter predicted for the galactic halo according to the standard cosmology. Similar results have also been obtained for other nearby galaxies. The x-ray emission from hot gas is well correlated with the star formation rate and stellar mass, indicating that the heating is primarily due to the stellar feedback. However, the observed x-ray luminosity of the gas is typically less than a few percent of the feedback energy. Thus the bulk of the feedback (including injected heavy elements) is likely lost in galaxy-wide outflows. The results are compared with simulations of the feedback to infer its dynamics and interplay with the circumgalactic medium, hence the evolution of galaxies.
Multiwavelength properties of blazars

The multiwavelength spectra of blazars appear to be dominated by nonthermal emission from a relativistic jet oriented close to the line of sight. The recent detection of many blazars at gamma-ray energies strongly supports this scenario. High quality multiwavelength monitoring data for the brightest one or two blazars suggest the optical through X-ray continuum is synchrotron emission from an inhomogeneous jet. The gamma-rays are likely due to Compton scattering of lower energy photons, either from within the jet or from the surrounding gas. The physical properties of the jet and the way in which it is produced are still largely a mystery but are probably related in some way to accretion onto a central supermassive black hole. There is little direct observational evidence for accretion disks in blazars, although there is evidence for winds which might emanate from disks.
Roentgenographic method for measurement of the cross-sectional area of the aortic valve.

Abstract The aortic valve in living subjects can be viewed as if looding directly into the valvular orifice by obtaining roentgenograms directed through the heart on a line approximately from the right shoulder to the left iliac crest. This roentgenographic projection (45 degree superior elevation, 0 degree anterior elevation) was determined by trigonometrical calculations based upon the spacial orientation of aortic ball-valve prostheses in 31 patients. Calculations based on data from these patients indicated that the aortic valve can be shown on roentgenograms taken in this projection with less than 10 per cent distortion of the cross-sectional area of the valve orifice in 8 of 10 patients. Consequently, it was feasible to measure the cross-sectional area of the aortic valve by planimetry of the projected image on the roentgenograms. The method was tested in 18 patients with aortic ball-valve prostheses because in such patients the precise cross-sectional area of the valve orifice was known. The roentgenographic method was at least 80 per cent accurate in 15 of 18 patients. During cardiac catheterization in 21 patients, roentgenographic measurements of the cross-sectional area of the aortic valve, using this same projection, were made on serial films obtained during the injection of contrast material in the supra-aortic region. Roentgenographic measurements correlated well with clinical and hemodynamic data and direct measurements at surgery. These results indicate that the cross-sectional area of the aortic valvular orifice frequently can be measured in a meaningful fashion with this method. Orifice area can be measured roentgenographically in patients in whom hydraulic equations would not be applicable. Obviously, roentgenographic measurements are subject to interpretation in spite of theoretical considerations based upon trigonometrical calculations. Incomplete opening of the aortic valve, due to a low stroke volume, can simulate an apparently small orifice. Eddies of contrast in the sinus of Valsalva can simulate a larger than actual orifice. In the majority of patients, this roentgenographic method of visualization of the aortic valve gives useful information regarding the cross-sectional area of the valvular orifice and the configuration of the valvular leaflets.
Solving 2D QCD with an adjoint fermion analytically

We present an analytic approach to solving 1 + 1 dimensional QCD with an adjoint Majorana fermion. In the UV this theory is described by a trivial CFT containing free fermions. The quasi-primary operators of this CFT lead to a discrete basis of states which is useful for diagonalizing the Hamiltonian of the full strongly interacting theory. Working at large-N, we find that the decoupling of high scaling-dimension quasi-primary operators from the low-energy spectrum occurs exponentially fast in their scaling-dimension. This suggests a scheme, whereby, truncating the basis to operators of dimension below Δmax, one can calculate the low-energy spectrum, parametrically to an accuracy of e −Δmax (although the precise accuracy depends on the state). Choosing Δmax = 9.5 we find very good agreement with the known spectrum obtained earlier by numerical DLCQ methods. Specifically, below the first three-particle threshold, we are able to identify all six single-particle bound-states, as well as several two-particle thresholds.
Thermal modeling and analysis of laser calorimeters

We performed detailed thermal analysis and modeling of the C-series laser calorimeters at the National Institute of Standards and Technology for calibrating laser power or energy meters. A finite element method was employed to simulate the space and time dependence of temperature at the calorimeter receiver. The inequivalence hi the temperature response caused by different spatial distributions of the heating power was determined. The inequivalence between electrical power applied to the front and rear portions of the receiver is ^1.7%, and the inequivalence between the electrical and laser heating is estimated to be <0.05%. The computational results are hi good agreement with experiments at the 1% level. The effects of the deposited energy, power duration, and relaxation tune on the calibration factor and cooling constant were investigated. This article provides information for future design improvement on the laser calorimeters. Nomenclature A = area of the cavity aperture, m2 Ac = cross-sectional area of the wire, m2 b = thermopile responsivity, V/K C = heat capacity, J/K
HOW TO REGULATE MEDICAL TOURISM (AND WHY IT MATTERS FOR BIOETHICS)

A growing literature examines descriptive and normative questions about medical tourism such as: How does it operate? What are its effects? Are home country patients or their governments failing in moral duties by engaging in or permitting medical tourism? By contrast, much less has been written on the regulatory dimension: What might be done about medical tourism if we were convinced that it posed ethical issues and were motivated to act? I shall argue that this kind of regulatory analysis is essential for bioethical analysis of medical tourism. This article focuses on these regulatory questions more directly, evaluating available methods, restrictions, costs, and benefits of home and destination country unilateral regulatory moves. This article also discusses more briefly multilateral treaty and private sector responses.
Religion and Science: Beyond the Epistemological Conflict Narrative

Studies of the relationship between religion and science have traditionally assumed that any conflict that exists is based on epistemology. This assumption is built into the history of Western academic thought, the founding of sociology itself, as well as the common definitions of religion used by social scientists. This assumption has hindered the examination of the relationship between religion and science. We categorize studies of the relationship between science and religion into three groups: the symbolic epistemological conflict studies, the symbolic directional influence studies, and the social-institutional studies. We find that the social-institutional studies, which most closely examine actual public conflicts, do not presume that the conflict is over epistemological claims and offer a more general and fruitful approach to examining the relationship between religion and science.
High-Altitude Limit Cycle Flutter of Transonic Wings

In flutter testing, it is often implicitly assumed that the most critical case at any given Mach number will occur at sea level conditions. This is a reasonable expectation, as the highest dynamic pressure at a fixed Mach number will be encountered at sea level, where the air density is highest. In the present paper, a counterexample involving a generic swept wing representative of transport aircraft is presented in which transonic limit cycle flutter is predicted to occur at altitude rather than at sea level. The calculations are based on a time-accurate Eulerian-Lagrangian finite element scheme that fully accounts for both structural and aerodynamic nonlinearities arising from large deflections and shock motion. Flutter onset is around Mach 0.84 and the limit cycle amplitudes grow until Mach 0.95 is reached, at which point they start decreasing, vanishing abruptly around Mach 0.97. The limit cycle flutter persists down to very low air densities, corresponding to altitudes above 75,000 ft, and the maximum limit-cycle-oscillation flutter amplitude does not occur at sea level, but at altitude. If sufficient structural damping is added, the wing will be flutter-free at lower altitudes but not at higher (cruise) altitudes. At Mach 0.95, the wing is stable below about 15,000 ft, even in the absence of structural damping, but experiences strong limit cycle flutter at higher altitudes.
Online learning in opportunistic spectrum access: A restless bandit approach

We consider an opportunistic spectrum access (OSA) problem where the time-varying condition of each channel (e.g., as a result of random fading or certain primary users' activities) is modeled as an arbitrary finite-state Markov chain. At each instance of time, a (secondary) user probes a channel and collects a certain reward as a function of the state of the channel (e.g., good channel condition results in higher data rate for the user). Each channel has potentially different state space and statistics, both unknown to the user, who tries to learn which one is the best as it goes and maximizes its usage of the best channel. The objective is to construct a good online learning algorithm so as to minimize the difference between the user's performance in total rewards and that of using the best channel (on average) had it known which one is the best from a priori knowledge of the channel statistics (also known as the regret). This is a classic exploration and exploitation problem and results abound when the reward processes are assumed to be iid. Compared to prior work, the biggest difference is that in our case the reward process is assumed to be Markovian, of which iid is a special case. In addition, the reward processes are restless in that the channel conditions will continue to evolve independent of the user's actions. This leads to a restless bandit problem, for which there exists little result on either algorithms or performance bounds in this learning context to the best of our knowledge. In this paper we introduce an algorithm that utilizes regenerative cycles of a Markov chain and computes a samplemean based index policy, and show that under mild conditions on the state transition probabilities of the Markov chains this algorithm achieves logarithmic regret uniformly over time, and that this regret bound is also optimal. We numerically examine the performance of this algorithm along with a few other learning algorithms in the case of an OSA problem with Gilbert-Elliot channel models, and discuss how this algorithm may be further improved (in terms of its constant) and how this result may lead to similar bounds for other algorithms.
Status report on multi-cell superconducting cavity development for medium-velocity beams

The Rare Isotope Accelerator (RIA) is being designed to supply an intense beam of exotic isotopes for nuclear physics research. Superconducting cavities are to be used to accelerate the CW beam of heavy ions to 400 MeV per nucleon, with a beam power of up to 400 kW. Because of the varying beam velocity, several types of superconducting structures are needed. This paper covers the fabrication of three prototype RIA 6-cell /spl beta//sub g/ = 0.47 cavities and the RF tests on the first and second of these cavities.
Volumetric ray tracing

This paper presents an eficient ray tracing method for scenes containing volumetric as well as geometric data. A global illumination equation is developed for this method, which is able to capture in a single image both realistic eaects and practical volume rendering. In this method, ray-object intersection calculations result in standard intersection points, as well as intersection segments. For accuracy and eflciency, all objects along a ray are sorted according to distance and intersection classification before any intersection calculations are pelformed. The intersection results are then passed to a shaden which evaluates the intensity equation defined by the illumination model to determine the final pixel value.
Relationships between physician advice and tobacco and alcohol use during pregnancy.

Abstract Introduction: We sought to examine relationships between physician advice and use of tobacco and alcohol during pregnancy among 683 women in the upper Midwest. Methods: Data on risk of substance use during pregnancy were analyzed using logistic regression analysis. Results: A higher proportion of women used tobacco (34%) than alcohol (25%) during their most recent pregnancy. Women who received advice from a physician to abstain from alcohol reported a lower risk of smoking and drinking during pregnancy than women who did not receive such advice. Risk of smoking and drinking during pregnancy was also common among women who reported early onset of alcohol use. Conclusions: Results suggest that physician advice regarding alcohol use during pregnancy is protective against maternal smoking and drinking during pregnancy.
Cryogenic detectors of particles: hopes and challenges

The various methods proposed for cryogenic detection of particles, the current status of their development, and their potential applications are reviewed. The discussion covers quasiparticle detectors and phonon detectors. An extensive bibliography is included as well as a table summarizing cryogenic detector developments identifying institutions and their particular physics interests. >
Robust Hurwitz property of bivariate polynomials in the space of Markov parameters

A procedure is given to determine the interval within which the Markov parameters of a general polynomial, such as real and complex univariate as well as real bivariate, might be allowed to vary so that the strict Hurwitz property remains invariant. These results may be generalized to multivariable polynomials, with complex coefficients. Based on the fact that the space of Markov parameters is a convex one this method may be used to find a quick qualitative measure of the degree of stability robustness for a nominal polynomial of a general type, i.e. interval, polytopic, and multilinear, whose treatment in general is impractical in the space of polynomial coefficients, from a computational point of view. >
Pair correlations and merger bias

We analytically study the possibility that mergers of haloes are more highly clustered than the general population of haloes of comparable masses. We begin by investigating predictions for merger bias within the extended Press‐Schechter formalism and discuss the limitations and ambiguities of this approach. We then postulate that mergers occur whenever two objects form within a (small) fixed distance of each other. We therefore study the clustering of pairs of points for a highly biased population in the linear regime, for the overall mass distribution in the quasi-linear regime and (using the halo model of clustering) in the non-linear regime. Biasing, quasi-linear evolution and non-linear clustering all lead to non-zero reduced (or connected) three- and four-point correlation functions. These higher order correlation functions can in many cases enhance the clustering of close pairs of points relative to the clustering of individual points. If close pairs are likely to merge, then the clustering of mergers may be enhanced. We discuss implications for the observed clustering of luminous z = 3 galaxies and for correlations of active galactic nuclei and galaxy clusters.
Generating neural networks through the induction of threshold logic unit trees

Abstract This paper investigates the generation of neural networks through the induction of binary trees of threshold logic units (TL Us Initially, it describes the framework for a tree construction algorithm devised by the author, and shows how it helps to bridge the gap between pure connectionist (neural network) and symbolic (decision tree) paradigms. It also shows how the trees of threshold units that are induced can be transformed into an isomorphic neural-network topology. Several methods for learning the linear discriminant functions at each node of the tree structure are examined, and are shown to produce accuracy results that are comparable to classical information-theoretic methods for constructing decision trees (which use single feature tests at each node), but produce trees that are smaller and thus easier to understand. Moreover, the results also show that it is possible to simultaneously learn both the topology and weight settings of a neural network simply using the training data set that is initially given.
ELECTRON-ION RECOMBINATION RATE COEFFICIENTS AND PHOTOIONIZATION CROSS SECTIONS FOR ASTROPHYSICALLY ABUNDANT ELEMENTS. V. RELATIVISTIC CALCULATIONS FOR Fe XXIV AND Fe XXV FOR X-RAY MODELING

Photoionization and recombination cross sections and rate coefficients are calculated for Li-like Fe XXIV and He-like Fe XXV using the Breit-Pauli R-matrix (BPRM) method. A complete set of total and level-speci—c parameters is obtained to enable X-ray photoionization and spectral modeling. The ab initio calculations for the uni—ed (e ] ion) recombination rate coefficients include both the nonresonant and the resonant recombination (radiative and dielectronic recombination, RR and DR, respectively) for (e ] Fe XXV) ] Fe XXIV and (e ] Fe XXVI) ] Fe XXV. The level-speci—c rates are computed for all —nestructure levels up to n \ 10, enabling accurate computation of recombination-cascade matrices and eUective rates for the X-ray lines. The total recombination rate coefficients for both Fe XXIV and Fe XXV diUer considerably from the sum of RR and DR rates currently used to compute ionization fractions in astrophysical models. As the photoionization/recombination calculations are carried out using an identical eigenfunction expansion, the cross sections for both processes are theoretically self-consistent; the overall uncertainty is estimated to be about 10%¨20%. All data for Fe XXIV and Fe XXV (and also for H-like Fe XXVI, included for completeness) are available electronically.
Screening Factors in Late Stellar Evolution

Recent studies (DeWitt et al., 1973; Graboske et al., 1973) have modified the screening factors for nuclear reactions. The theory develops a general statistical mechanical framework within which the various analytical models of Salpeter are combined with Monte Carlo and perturbation calculations for specific mixtures. The result is a general effective screening function in terms of the reacting charges Z 1, Z 2 and the plasma properties ϱ, T and \( \bar {\rm Z}\) This screening function greatly enhances the screening effects for presupernova models (Couch and Arnett, 1973; Bruenn, 1973) reducing carbon ignition densities in the 4–8 M ⊙ range by a factor of two, and even more for degenerate O and Si burning.
Truth in Convicting: Understanding and Evaluating Apprendi

In Apprendi v. New Jersey,1 a closely divided Supreme Court held that a twelve-year prison term imposed under a New Jersey law that raised the maximum sen tence for the defendant's crime from ten to twenty years imprisonment upon a judge's post-conviction finding that the crime was committed "with a purpose to intim idate an individual ... because of race,"2 violated the Constitution. Apprendi is the most recent installment in a series of Supreme Court cases over the past thirty years addressing a core issue in criminal law: what are the constitutional limits on the legislature's discretion in defining crimes and their elements. Over the decades, the Court has famously zigzagged between tantalizing suggestions of broad constitutional limita tions and powerful endorsements of legislative primacy,3 with the latter position obtaining the upper hand at the end of each stage of development.4 These cases have closely divided the Court over the years, yielding unusual alliances5 and a murky jurisprudence. Apprendi is no exception. This essay examines Apprendi to determine the extent of the Court's holding and its immediate ramifications, including the effect on federal drug pros ecutions under 21U.S.C.I841. The essay concludes that Apprendi''s holding, which could be described as a "truth-in-convicting" rule, is modest in scope but nonetheless significant. The essay draws two further conclusions. First, in returning to this difficult area, the Court was wise to take a cautious, "rule-based" first step. Second, advocates of guidelines sentencing sys tems ought to welcome, rather than fear, Apprendi's gentle but important restriction on legislative power.
Higgs boson decay into Z bosons and a photon

We present a brief summary of our one-loop calculation of the width Γ(H→ZZγ) in the standard model for Higgs boson masses 195 GeV ≤ mH ≤ 250 GeV. The helicity amplitudes contain a contribution from the anomalous ZZγ triangle graph and the most dominant helicity combinations for the Z bosons and the photon are when one of the Z bosons is longitudinally polarized and the other has the same helicity as the photon. This decay is, however, highly suppressed. The ratios of Γ(H→ZZγ) to other one-loop Higgs decays are Γ(H→ZZγ)/Γ(H→γγ) ~ Γ(H→ZZγ)/Γ(H→γZ)10−7.
High Metallicity and Non-equilibrium Chemistry in the Dayside Atmosphere of hot-Neptune GJ 436b

We present a detailed analysis of the dayside atmosphere of the hot-Neptune GJ 436b, based on recent Spitzer observations. We report statistical constraints on the thermal and chemical properties of the planetary atmosphere, study correlations between the various molecular species, and discuss scenarios of equilibrium and non-equilibrium chemistry in GJ 436b. We model the atmosphere with a one-dimensional line-by-line radiative transfer code with parameterized molecular abundances and temperature structure. We explore the model parameter space with 10 6 models, using a Markov chain Monte Carlo scheme. Our results encompass previous findings, indicating a paucity of methane, an overabundance of CO and CO2, and a slight underabundance of H2O, as compared to equilibrium chemistry with solar metallicity. The concentrations of the species are highly correlated. Our best-fit, and most plausible, constraints require a CH4 mixing ratio of 10 7 to10 6 , with CO � 10 3 , CO2 � 10 6 to10 4 , and H2O � 10 4 ; higher CH4 would require much higher CO and CO2. Based on calculations of equilibrium and non-equilibrium chemistry, we find that the observed abundances can potentially be explained by a combination of high metallicity (� 10 × solar) and vertical mixing with Kzz � 10 6 10 7 cm 2 /s. The inferred metallicity is enhanced over that of the host star which is known to be consistent with solar metallicity. Our constraints rule out a dayside thermal inversion in GJ 436b. We emphasize that the constraints reported in this work depend crucially on the observations in the two Spitzer channels at 3.6 µm and 4.5 µm. Future observations with warm Spitzer and with the James Webb Space Telescope will be extremely important to improve upon the present constraints on the abundances of carbon species in the dayside atmosphere of GJ 436b. Subject headings: planetary systems — planets and satellites: general — planets and satellites: individual (GJ 436b) — radiative transfer
On the de Haas-Van Alphen Oscillation in 2D

The statistical weight W as a function of energy E for quasielectrons with mass m* subject to a fixed magnetic field B is $W/A = (m^*/ \pi \hbar^2)E + (eB/ \pi^2 \hbar) \Sigma_{\nu=1}^{\infty} (-1)^{\nu} \nu^{-1} \sin(2\pi \nu E/ \hbar \omega_c)$, where A is the sample area, and ωc ≡ eB/m* the cyclotron frequency. Significantly, there is no Landau term proportional to B2 in 2D. This leads to the conclusion that the 2D electron system is always paramagnetic, but shows a magnetic oscillation.
Sexual Orientation and Mental Health

This article provides an overview of current psychological research on mental health and sexual orientation, as well as clinical practice with sexual minorities. The historical context for current research questions and controversies is described, and the findings of recent empirical research on psychological well-being and distress among nonheterosexuals are summarized. The minority stress model is used to frame a discussion of stressors unique to sexual minorities and to consider their possible effects on psychological well-being. The possible ameliorative effects of adopting a sexual orientation identity are examined, followed by a discussion of how these ideas translate into contemporary clinical work with sexual minority clients. The review concludes with a brief discussion of priority areas for empirical research and clinical practice.
Supramolecular self-assembly directed by carborane C–H⋯F interactions

The synthesis and crystallization of 9,12-bis-(4-fluorophenyl)-1,2-carborane 1 and 9,12-bis-(3,5-difluorophenyl)-1,2-carborane 2 provide the first examples of a supramolecular assemblage directed by C–Hcarborane⋯F interactions.
Globalization and the Institutional Dynamics of Global Environmental Governance

This paper is concerned with globalization and the institutional dynamics of global environmental governance. How do the phenomena of globalization shape the study of the institutional dimensions of global environmental governance, and how do these phenomena influence the practicality of law and state-centric politics? These questions guide the direction of this paper and its aim to advance theories and research methods for the study of the dynamics of institutions for governance. By synthesizing the conceptual findings of the literature, this paper develops an analytical framework of globalization and analytical themes to advance the systematic study of the dynamics of institutions, which are inherent in the design, function, and effectiveness of international and global environmental institutions and governance.
Better off stateless: Somalia before and after government collapse

Could anarchy be good for Somalia's development? If state predation goes unchecked government may not only fail to add to social welfare, but can actually reduce welfare below its level under statelessness. Such was the case with Somalia's government, which did more harm to its citizens than good. The government's collapse and subsequent emergence of statelessness opened the opportunity for Somali progress. This paper investigates the impact of anarchy on Somali development. The data suggest that while the state of this development remains low, on nearly all of 18 key indicators that allow pre- and post-stateless welfare comparisons, Somalis are better off under anarchy than they were under government. Renewed vibrancy in critical sectors of Somalia's economy and public goods in the absence of a predatory state are responsible for this improvement. Journal of Comparative Economics35 (4) (2007) 689–710.
THE STELLAR HALOS OF MASSIVE ELLIPTICAL GALAXIES

We use the Mitchell Spectrograph (formerly VIRUS-P) on the McDonald Observatory 2.7 m Harlan J. Smith Telescope to search for the chemical signatures of massive elliptical galaxy assembly. The Mitchell Spectrograph is an integral-field spectrograph with a uniquely wide field of view (107'' × 107''), allowing us to achieve remarkably high signal-to-noise ratios of ~20-70 pixel–1 in radial bins of 2-2.5 times the effective radii of the eight galaxies in our sample. Focusing on a sample of massive elliptical galaxies with stellar velocity dispersions σ* > 150 km s–1, we study the radial dependence in the equivalent widths (EW) of key metal absorption lines. By twice the effective radius, the Mgb EWs have dropped by ~50%, and only a weak correlation between σ* and Mgb EW remains. The Mgb EWs at large radii are comparable to those seen in the centers of elliptical galaxies that are ~ an order of magnitude less massive. We find that the well-known metallicity gradients often observed within an effective radius continue smoothly to 2.5 Re , while the abundance ratio gradients remain flat. Much like the halo of the Milky Way, the stellar halos of our galaxies have low metallicities and high α-abundance ratios, as expected for very old stars formed in small stellar systems. Our observations support a picture in which the outer parts of massive elliptical galaxies are built by the accretion of much smaller systems whose star formation history was truncated at early times.
The Impact of Negativity on Separability Testing

During separability testing, it has not been common practice to verify if the data satisfy the negativity condition. The impacts of imposing negativity on separability test results are examined for two groups of commodities using Barten's generalized demand system and with Monte Carlo simulations. Results indicate that imposing negativity did not alter model estimates when negativity was spontaneously satisfied. Also, imposing negativity rarely altered separability test results when the data did not spontaneously satisfy negativity.
Synthesis and characterization of dibenzannulated silole dianions. The 1,1-dilithiosilafluorene and 1,1′-dilithiobis(silafluorene) dianions

Abstract Stirring of 1,1-dichloro-SiFl ( 1 ), (SiFl, silafluorene) in THF with excess lithium for 1 h gave a dark green solution of 1,1-dilithio-SiFl ( 2 ) in high yield. The dark red solution of the intermediate 1,1′-dilithio-(SiFl) 2 ( 3 ) was also observed from this reaction within 10 min. Treatment of 2 with excess trimethylchlorosilane gave the 1,1-bis(trimethylsilyl)-SiFl derivative ( 4 ) in 95% yield. Treatment of the dark red solution of 3 and 2 with excess methyliodide gave the 1,1′-dimethyl-bis(SiFl) ( 5 ) and 1,1-dimethyl-SiFl ( 6 ) derivatives in a 4:1 ratio. The upfield locations of the 29 Si resonances of dianions 2 and 3 (−1.09 ppm and −39.25 ppm, respectively) are consistent with π-electron localization on the silicon atoms.
Synthesis and Characterization of Di-[3-(Trimethylsilyl)-1-Propylene] Alkylenediphosphonic Acids

A homologous series of alkylenediphosphonic acids was successfully esterified with 3-(trimethylsilyl)-1-propanol to the symmetrically-substituted diesters. The procedure, which has general applicability for incorporating silicon heteroatoms into diphosphonic acids, utilizes the esterification reagent dicyclohexyl-carbodiimide (DCC) to activate the acid. The aggregation properties of the di-[3-(trimethylsilyl)-1-propylene] alkylenediphosphonic acids were measured in toluene and 1-decanol.
The response of a two-wire transmission line to incident field and voltage excitation, including the effects of higher order modes

The surface currents on a two-wire transmission line induced by incident field excitations are investigated using the spectral concept. A simple solution is obtained for plane wave excitation. A solution for voltage source excitation, in which the induced current may be given, at least approximately, by means of the so-called leaky-wave concept, is considered. The influence of the electrical dimensions of the structure on the currents and the relative importance of the higher modes are examined by numerical examples.
TENANCY RENT CONTROL AND CREDIBLE COMMITMENT IN MAINTENANCE

Under tenancy rent control, rents are regulated within a tenancy but not between tenancies. This paper investigates the eects of tenancy rent control on housing quality, maintenance, and rehabilitation. Since the discounted revenue received over a …xed-duration tenancy depends only on the starting rent, intuitively the landlord has an incentive to spruce up the unit between tenancies in order to "show"it well, but little incentive to maintain the unit well during the tenancy. The paper formalizes this intuition, and presents numerical examples illustrating the e¢ ciency loss from this eect.
Free Vibration of Stiffened Rectangular Plates Using Green's Functions and Integral Equations

A new method for the free-vibration analysis of stiffened rectangular plates based on the use of Green's functions and the solution of a system of Fredholm integral equations of the second kind is demonstrated. The lateral forces and twisting moments of constraint between the plate and beam stiffeners are accounted for. For plates with simply supported edges perpendicular to the stiffeners the integral equations are solved exactly to yield the characteristic equations for the natural frequencies. The characteristic equations are then solved to yield the exact natural frequencies (within the context of the mathematical model chosen). The pertinent parameters of the problem all appear explicitly in the characteristic equation which then has implications for its use as a mathematical design tool. The exact natural modes can be calculated and the orthogonality relation for the natural modes is given which implies that the forced response of the stiffened plate, including the effects of damping, can be determined by modal analysis. As an example, a table and figures show the natural frequencies for a stiffened simply supported rectangular plate with a single stiffener.
A New Discrete Quantitative Randomized Response Model

Abstract The Randomized Response Technique, which was originally developed for qualitative purposes, is being developed for quantitative purposes, and the current article presents a new discrete quantitative RRT model. This model uses a predetermined combination of balls in the randomizing device, instead of asking an innocuous question. It has been shown that the procedures of administering the model is simple and that its efficiency of estimate is higher than the other currently available models.
Can we derive general world knowledge from texts

As one attack on the "knowledge acquisition bottleneck", we are attempting to exploit a largely untapped source of general knowledge in texts, lying at a level beneath the explicit assertional content. This knowledge consists of relationships implied to be possible in the world, or, under certain conditions, implied to be normal or commonplace in the world. The goal of the work reported is to derive such general world knowledge (initially, from Penn Tree-bank corpora) in two stages: first, we derive general "possibilistic" propositions from noun phrases and clauses; then we try to derive stronger generalizations, based on the nature and statistical distribution of the possibilistic claims obtained in the first phase. Here we report preliminary results of the first phase, which indicate the feasibility of our project, and its likely limitations.
Mechanistic Organic Photochemistry

Organic photochemical reactions can be understood as transformations of the electronically excited states of the reactant molecules. By considering Lewis structure or molecular orbital representations of these excited states it is possible to outline the several possible reactions available in the case of a given reactant. A number of different types of photochemical transformations are now reasonably well understood. In these cases one finds the same common controlling feature, namely the tendency for an excited state species to follow mechanistic pathways of minimum energy and the requirement for continuous electron redistribution in following these pathways. These preferred transformations can often be selected by inspection of relative bond orders for different types of bonding, by comparison of the potential energy surfaces available to the excited state molecules, and by use of correlation diagrams. The reactions derive from both singlet and triplet states, and one of the more reliable methods now available for identifying excited states reacting is termed the “fingerprint method”. Examples of the author's mechanistic approach are given both for ketone and for hydrocarbon photochemistry.
Systematic defect identification through layout snippet clustering

Systematic defects due to design-process interactions are a dominant component of integrated circuit (IC) yield loss in nano-scaled technologies. Test structures do not adequately represent the product in terms of feature diversity and feature volume, and therefore are unable to identify all the systematic defects that affect the product. This paper describes a method that uses diagnosis to identify layout features that do not yield as expected. Specifically, clustering techniques are applied to layout snippets of diagnosis-implicated regions from (ideally) a statistically-significant number of IC failures for identifying feature commonalties. Experiments involving an industrial chip demonstrate the identification of possible systematic yield loss due to lithographic hotspots.
Degree Bounds for Polynomial Verification of the Matrix Cube Problem

In this paper we consider the problem of how to computationally test whether a matrix inequality is positive semidefinite on a semi-algebraic set. We propose a family of sufficient conditions using the theory of matrix Positivstellensatz refutations. When the semi-algebraic set is a hypercube, we give bounds on the degree of the required certificate polynomials.
The natural history of verb-stem reduplication in Bantu

In this study I present a comparative and historical analysis of “frequentative” Bantu verb-stem reduplication, many of whose variants have been described for a number of Eastern and Southern Bantu languages. While some languages have full-stem compounding, where the stem consists of the verb root plus any and all suffixes, others restrict the reduplicant to two syllables. Two questions are addressed: (i) What was the original nature of reduplication in Proto-Bantu? (ii) What diachronic processes have led to the observed variation? I first consider evidence that the frequentative began as full-stem reduplication, which then became restricted either morphologically (by excluding inflectional and ultimately derivational suffixes) and/or phonologically (by imposing a bisyllabic maximum size constraint). I then turn to the opposite hypothesis and consider evidence and motivations for a conflicting tendency to rebuild full-stem reduplication from the partial reduplicant. I end by attempting to explain why the partial reduplicant is almost always preposed to the fuller base.
Effects of sample handling temperatures on bovine skim milk progesterone concentrations

The effects of incubation of whole milk at various temperatures and times on the concentration of progesterone in the skim milk fraction was determined. For the study, milk samples were collected from 10 pregnant Holstein cows. The milk from each cow was transferred to culture tubes to provide 32 replicates of 3 ml volume. To begin the incubation study, all samples were placed in a 37 °C water bath for 4 h. The end of this incubation was designated as time 0 and a sample from each cow was centrifuged to harvest skim milk. At time 0, samples from each cow were divided among incubation temperatures of 0 °, 4 °, 20 ° and 37 °C. Samples were removed from each incubation group at 30, 60, 90 and 120 min. After 120 min, all remaining samples were returned to the 37 °C incubation and skim milk was collected at 30, 60 and 90 min. Progesterone was measured in skim milk by radioimmunoassay. The mean ± SE concentration of progesterone in skim milk at time 0 was 10.9 ± 1.1 nmolL. The mean concentration of progesterone in skim milk was higher (P < 0.05) in all samples incubated at 0 ° and 4 °C, with incremental increases ranging from 34% to 67% above time 0. Progesterone in skim milk returned to time 0 concentrations in milk samples transferred from 0 ° or 4 °C to 37 °C. There was no change in skim milk progesterone in whole milk samples incubated at 20 ° or 37 °C. From this study, it can be concluded that the concentration of progesterone in skim milk is temperature dependent. Inconsistency in handling whole milk samples can have a profound effect in the concentration of progesterone on skim milk. The temperature-dependent effect was reversible and may be related to solubility of progesterone in milk fat.
RNA methylation by the MIS complex regulates a cell fate decision in yeast

For the yeast Saccharomyces cerevisiae, nutrient limitation is a key developmental signal causing diploid cells to switch from yeast-form budding to either foraging pseudohyphal (PH) growth or meiosis and sporulation. Prolonged starvation leads to lineage restriction, such that cells exiting meiotic prophase are committed to complete sporulation even if nutrients are restored. Here, we have identified an earlier commitment point in the starvation program. After this point, cells, returned to nutrient-rich medium, entered a form of synchronous PH development that was morphologically and genetically indistinguishable from starvation-induced PH growth. We show that lineage restriction during this time was, in part, dependent on the mRNA methyltransferase activity of Ime4, which played separable roles in meiotic induction and suppression of the PH program. Normal levels of meiotic mRNA methylation required the catalytic domain of Ime4, as well as two meiotic proteins, Mum2 and Slz1, which interacted and co-immunoprecipitated with Ime4. This MIS complex (Mum2, Ime4, and Slz1) functioned in both starvation pathways. Together, our results support the notion that the yeast starvation response is an extended process that progressively restricts cell fate and reveal a broad role of post-transcriptional RNA methylation in these decisions.
Rule By Aesthetics: World-Class City Making in Delhi

This project addresses the cultural and environmental politics of slum demolitions in the making of a world-class city. If modern cities are supposed to be built through techno-scientific procedures of urban planning and government--such as maps, censuses, and surveys--the conspicuous absence of such techniques in the world-class redevelopment of Delhi raises the question of how rule there is achieved. Based on an ethnography of the judiciary, state, and property owners' associations, I find that what I call a world-class aesthetic--an idealized vision of a privatized, green, and slum-free city assembled from transnationally circulating images of global cities --has replaced these techniques as the key instrumentality of rule in contemporary Delhi. To explore how this aesthetic regime of planning operates, I begin by demonstrating how the city's new good governance initiative, called Bhagidari, has reconfigured state space, providing property owners' with privileged channels of access to the judiciary and bureaucracy. By tracing the circulation of key representations of the slum through and beyond these channels, I show how discourse depicting slums as nuisances --i.e., as illegal environments--constructs an aesthetic grid that demarcates the world-class on the one hand, and the polluting on the other. I further reveal how the judiciary has codified this world-class aesthetic through a reinterpretation of nuisance law, recalibrating the axes of legality and planning such that those spaces appearing polluting and dirty (e.g., slums) are deemed unplanned and illegal, regardless of their statutory basis in planning law or actual environmental impact. Conversely, spaces that have a world-class look (e.g., shopping malls, sports stadia), despite violating land-use codes and environmental standards, are deemed planned and legal. More than just reconfiguring state power, this aesthetic regime of planning alters how citizens see and engage the state, as well as how they envision their place in the city. Based on a year of ethnographic fieldwork in a Delhi slum, I show how residents have begun to shift the basis on which they advance citizenship claims away from an earlier idiom of historical entitlement to public land and toward one of potential self-improvement via home ownership. This shift, however, cannot be reduced to an overarching neoliberal rationality, but must rather be located in residents' changing affective ties to place and city. Specifically, I trace how a series of political technologies--including government-run slum surveys, media campaigns, and a broad set of changes in the meaning of landscape--train slum residents to see the city through the lens of world-class aesthetics. In arguing that projects of rule are secured as much through embodied practices and aesthetic dispositions as through reason or ideology, the dissertation argues for the importance of everyday aesthetic practices as a key terrain on which political possibilities and urban visions are produced.
Projected increase in lightning strikes in the United States due to global warming

Lightning plays an important role in atmospheric chemistry and in the initiation of wildfires, but the impact of global warming on lightning rates is poorly constrained. Here we propose that the lightning flash rate is proportional to the convective available potential energy (CAPE) times the precipitation rate. Using observations, the product of CAPE and precipitation explains 77% of the variance in the time series of total cloud-to-ground lightning flashes over the contiguous United States (CONUS). Storms convert CAPE times precipitated water mass to discharged lightning energy with an efficiency of 1%. When this proxy is applied to 11 climate models, CONUS lightning strikes are predicted to increase 12 ± 5% per degree Celsius of global warming and about 50% over this century.
Dynamic Compensation Contracts with Private Savings

This article studies a dynamic agency problem in which a risk-averse agent can save privately. In the optimal contract, (i) cash compensations exhibit downward rigidity to failures; (ii) permanent pay raises occur when the agent’s historical performance is sufficiently good; (iii) and when the agent is dismissed due to poor performance, he walks away with severance pay to support his post-firing consumption at the current compensation level. Thus, the theory can simultaneously explain the popularity of optionslike compensation contracts and the increasing incidence of forced turnovers with sizeable severance pay. (JEL D86, J31, J33)
DEFENSA JUDICIAL DE LOS DERECHOS HUMANOS EN LOS ESTADOS DE EXCEPCIÓN

Desde antiguo, en el curso de la historia, los estados han venido atravesando situaciones de crisis entre las que cabe mencionar la guerra externa o interna, las alteraciones graves al orden publico, el peligro para la seguridad interior y las calamidades o catastrofes. Tales situaciones habilitan a los Gobiernos para declarar el correspondiente Estado de Excepcion Constitucional (E.E.C.) y ejemplo de ellos es la Dictadura romana. En los E.E.C. algunos derechos fundamentales pueden ser limitados con el objeto de subsanar la crisis y volver a la normalidad. La Constitucion chilena regula cuatro E.E.C. y garantiza que solo en el curso de ellos pueden suspenderse o restringirse ciertos derechos fundamentales. Este estudio versa sobre la proteccion judicial de tales derechos durante los E.E.C.