cssi/SciSciGPT-SciSciNet huggingface dataset:
SPITZER SPECTROSCOPY OF CIRCUMSTELLAR DISKS IN THE 5 Myr OLD UPPER SCORPIUS OB ASSOCIATION

We present mid-infrared spectra between 5.2 and 38 μm for 26 disk-bearing members of the ~5 Myr old Upper Scorpius OB association obtained with the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope. We find clear evidence for changes in the spectral characteristics of dust emission between the early-type (B+A) and late-type (K+M) infrared excess stars. The early-type members exhibit featureless continuum excesses that become apparent redward of ~8 μm. In contrast, 10 and 20 μm silicate features or polycyclic aromatic hydrocarbon emission are present in all but one of the late-type excess members of Upper Scorpius. The strength of silicate emission among late-type Upper Scorpius members is spectral-type dependent, with the most prominent features being associated with K5-M2-type stars. By fitting the spectral energy distributions (SED) of a representative sample of low-mass stars with accretion disk models, we find that the SEDs are consistent with models having inner disk radii ranging from ~0.2 to 1.2 AU. Complementary high-resolution (R ~ 33,000) optical (λλ4800-9200) spectra for the Upper Scorpius excess stars were examined for signatures of gaseous accretion. Of the 35 infrared excess stars identified in Upper Scorpius, only seven (all late-type) exhibit definitive signatures of accretion. Mass-accretion rates (M) for these stars were estimated to range from 10^–11 to 10^–8.9 M⊙ yr^–1. Compared to Class II sources in Taurus-Auriga, the disk population in Upper Scorpius exhibits reduced levels of near- and mid-infrared excess emission and an order of magnitude lower mass-accretion rates. These results suggest that the disk structure has changed significantly over the 2-4 Myr in age separating these two stellar populations. The ubiquity of depleted inner disks in the Upper Scorpius excess sample implies that such disks are a common evolutionary pathway that persists for some time.
Brittle Failure of Ice

Ice exhibits either ductile or brittle behavior, depending upon the conditions under which it is loaded. Glaciers, for instance, are loaded by gravity, under deviatoric stresses of ~0.1 MPa or lower. At temperatures of interest, they flow through dislocation creep at strain rates of the order of 10−9 s−1 or lower (Patterson 1994). Sheets of sea ice—another terrestrially important ice feature—are loaded predominantly by wind, under global compressive stresses similar in magnitude to the shear stresses within glaciers (Richter-Menge and Elder 1998). These bodies deform through a combination of creep and fracture, the latter process manifested by oriented leads or open cracks and by compressive shear faults which often form as conjugate sets that traverse a large fraction of the Arctic Basin (Kwok 1999; Schulson 2002). The cold, icy crust of Europa, an extraterrestrial feature which may shield an ocean beneath within which a form of life may exist or may once have existed (Reynolds et al. 1987; Hoppa et al. 1999; Pappalardo et al. 1999; Greenberg et al. 2000; Kargel et al. 2000), is loaded by the motion of diurnal tides and by non-synchronous rotation (Greenberg and Weidenschilling 1984). The crust deforms in a brittle manner, as evident from the networks of cracks that lace through it (Greeley et al. 2000). Of the two kinds of ice deformation, creep is probably the better known by readers of the geological and geophysical literature, and is certainly the more fully explored and better understood. The interested reader may wish to consult a number of excellent reviews of the subject (e.g., see Duval et al. 1983; Weertman 1983; Durham and Stern 2001). Fracture, in comparison, has only recently been systematically examined. The motivation with respect to terrestrial mechanics (Schulson 2001) comes largely …
Optimization of Geoscience Laser Altimeter System waveform metrics to support vegetation measurements

Abstract The Geoscience Laser Altimeter System (GLAS) has collected over 250 million measurements of vegetation height over forests globally. Accurate vegetation heights can be determined using waveform metrics that include vertical extent and extent of the waveform's trailing and leading edges. All three indices are highly dependent upon the signal strength, background noise and signal-to-noise ratio of the waveform, as the background noise contribution to the waveforms has to be removed before their calculation. Over the last six years, GLAS has collected data during thirteen observation periods using illumination from three different lasers. The power levels of these lasers have changed over time, resulting in variable signal power and noise characteristics. Atmospheric conditions vary continuously, also influencing signal power and noise. To minimize these effects, we optimized a noise coefficient which could be constant or vary according to observation period or noise metric. This parameter is used with the mean and standard deviation of the background noise to determine a noise level threshold that is removed from each waveform. An optimization analysis was used with a global dataset of waveforms that are near-coincident with waveforms from other observation periods; the goal of the optimization was to minimize the difference in vertical extent between spatially overlapping GLAS observations. Optimizations based on absolute difference in height led to situations in which the total extent was minimized as well; further optimizations reduced a normalized difference in height extent. The simplest optimizations were based on a constant value to be applied to all observations; noise coefficients of 2.7, 3.2, 3.4 and 4.0 were determined for datasets consisting of global forests, global vegetation, forest in the legal Amazon basin and boreal forests respectively. Optimizations based on the power level or the signal-to-noise ratio of waveforms best minimized differences in waveform extent, decreasing the percent root mean squared height difference by 25–54% over the constant value approach. Further development of methods to ensure temporal consistency of waveform indices will be necessary to support long-term satellite lidar missions and will result in more accurate and precise estimates of canopy height.
PROCYCLICAL AND COUNTERCYCLICAL FISCAL MULTIPLIERS: EVIDENCE FROM OECD COUNTRIES

Abstract Using non-linear methods, we argue that existing estimates of government spending multipliers in expansion and recession may yield biased results by ignoring whether government spending is increasing or decreasing. In the case of OECD countries, the problem originates in the fact that, contrary to one's priors, it is not always the case that government spending is going up in recessions (i.e., acting countercyclically). In almost as many cases, government spending is actually going down (i.e., acting procyclically). Since the economy does not respond symmetrically to government spending increases or decreases, the “true” long-run multiplier for bad times (and government spending going up) turns out to be 2.3 compared to 1.3 if we just distinguish between recession and expansion. In extreme recessions, the long-run multiplier reaches 3.1.
Gaze-directed volume rendering

We direct our gaze at an object by rotating our eyes or head until the object's projection falls on the fovea, a small region of enhanced spatial acuity near the center of the retina. In this paper, we explore methods for encorporating gaze direction into rendering algorithms. This approach permits generation of images exhibiting continuously varying resolution, and allows these images to be displayed on conventional television monitors. Specifically, we describe a ray tracer for volume data in which the number of rays cast per unit area on the image plane and the number of samples drawn per unit length along each ray are functions of local retinal acuity. We also describe an implementation using 2D and 3D mip maps, an eye tracker, and the Pixel-Planes 5 massively parallel raster display system. Pending completion of Pixel-Planes 5 in the spring of 1990, we have written a simulator on a Stellar graphics supercomputer. Preliminary results indicate that while users are aware of the variable-resolution structure of the image, the high-resolution sweet spot follows their gaze well and promises to be useful in practice.
Plasmon resonant Au nanospheres and nanorods in anodic alumina matrix

This paper discusses theoretical studies of optical properties of gold nanospheres and nanorods with various aspect ratios, embedded in porous anodic alumina matrix. We show in this study that when the alumina template is made under certain conditions, nanostructures with diameters in the 15-25nm range can be synthesized. Embedding gold particles of nanometer dimensions into a dielectric matrix provides a simple way to study the optical properties of the particles. Plasmon resonance wavelength for gold nanospheres and nanorods with different aspect ratios embedded in porous anodic alumina matrix are computed and discussed in this study. Recently, the plasmons in porous anodic alumina matrix have been considered for quasi-non-diffractive nano-optics applications. Other potential applications of the noble metal nanoparticles include optical filters and sensors.
Nature of metal catalyst precursors adsorbed onto oxide supports

Abstract In this work, three sets of experiments were conducted to investigate the nature of adsorbed catalyst precursor complexes during and after drying. In the first, PdCl 2− 4 was adsorbed onto a positively charged Al 2 O 3 surface and (NH 3 ) 4 Pd 2+ onto negatively charged SiO 2 . It is shown that there is a maximum adsorption density and that the anion adsorbs with at least one hydration sheath intact while the cation appears to retain two hydration sheaths. These results are supported by a comparison of adsorption density (μmole/m 2 ) with literature values. In the second, the stability of the precursor was studied as a function of drying temperature. Both the electrostatically adsorbed chloride and ammine precursors could be induced to desorb after drying at room temperature. At elevated temperatures, desorption of the chloride precursor could not be induced at 60°C or higher (presumably the adsorbed precursor had decomposed and become anchored to the surface), while the ammine precursor could be induce to desorb to a significant extent from silica up to calcination temperatures of 185°C. In the final experiment, migration through pellets during drying of an initially homogeneously dispersed precursor (AHM) was studied. If electrostatics are favorable (oppositely charged precursor and support) then there is strong adsorption and no migration. If the precursor and support have like charges, migration occurs during drying. In sum, the maximum adsorption density of Pd and Pt precursors can be calculated by a steric monolayer of hydrated complexes, and these adsorbed precursors appear to maintain their aqueous-like environment in which electrostatic effects persist, even through the drying step.
Speech Analysis using Modulation-Based Features for Detecting Deception

This paper reports on the initial results of analysis of speech features for detecting deception from speech utterances. The features are derived from the amplitude- and frequency-modulation (AM and FM) behavior of speech centered at different nominal formant frequencies. Analysis of truthful and deceptive speech, both established a posteriori, by a male speaker under jeopardy shows that Teager energy-related features, amplitude envelope-based parameters, and formant variations and bandwidths at selected frequencies have a potential to show subtle variations indicative of deception. For comparison, trajectory of the fundamental frequency of voicing was found to show relatively minor variations between truthful and deceptive speech.
Does legislative turnover adversely affect state expenditure policy? Evidence from Indian state elections

The effect of legislative turnover on the size and composition of government expenditures in Indian states over the 1980–2000 period is examined. The paper finds that excessive turnover in Indian state elections results in inefficient government expenditure policy. First, the higher the turnover, the larger the government size. Second, excessive turnover affects the allocative efficiency of government expenditures by skewing the composition of government spending toward pure consumption and away from more productive investment expenditures. Third, the effect of turnover on fiscal policy is not linear; public consumption expenditure is convex in turnover, while public investment expenditure is concave in turnover.
Diastereoselective metal-catalyzed [4 + 2 + 2] carbocyclization reactions utilizing a rhodium N-heterocyclic carbene (NHC) complex: the first example of a rhodium NHC-catalyzed [m+n+o] carbocyclization

The air and moisture stable rhodium N-heterocyclic carbene (NHC) complex, RhCl(IMes)(COD) (IMes = N,N′-bis(2,4,6-trimethylphenyl)imidazole-2-ylidine; COD = 1,5-cyclooctadiene), facilitates a diastereoselective metal-catalyzed [4 + 2 + 2] carbocyclization of 1,6-enynes in the presence of silver triflate and 1,3-butadiene.
Chiral Molecular Clefts For Dicarboxylic Acid Complexation

Three efficient cleft-type receptors, 3,5, and 6 have been prepared by attachment of two amidopyridine units as hydrogen bonding centers to either the 2,2′-positions of 9, 9′-spirobifluorene or the 6,6′-positions of 1,1′-binaphthyl spacers. The easy availability of these compounds in short synthetic routes make them attractive complexing agents for aliphatic and aromatic dicarboxylic acids which undergo bidentate binding in chloroform solution. 1H NMR binding studies show that substrates of different size can be accommodated into the clefts and form 1:1 complexes that are predominantly stabilized by multiple host-guesthydrogen bonds. The flexible aliphatic substrates diethylmalonic, 2,2-diphenylsuccinic, glutaric, and pimelic acid form complexes with association constants Ka ranging from 103 to 104 L mol−1. Significantly more stable complexes (Ka > 105 L mol−1) are obtained with the more rigid, preorganized substrate 5-dodecyloxyisophthalic acid.
Study of a 10-MW continuous Spallation Neutron Source

This paper reports on the feasibility study of a proton superconducting linac as the driver for an Accelerator-based Continuous Neutron Source (ACNS) to be located at Brookhaven National Laboratory (BNL). The Linac is to be operated in the continuous wave (CW) mode to produce an average 10 MW of beam power. The linac beam energy is taken to be 1.25 GeV. The required average proton beam intensity in exit is then 8 mA.
The Worldwide Movement in Private Universities: Revolutionary Growth in Post‐Secondary Higher Education

The end of the Cold War, which resulted from the collapse of communism and the spread of free market ideas in the former Soviet Union, China, and nations in Eastern Europe, has brought about many dramatic and momentous changes on the world scene. One remarkable development not widely recognized outside specialized academic circles is the emergence of new institutions of higher learning in the private sector of previously command economies and also in many developing countries that had been wedded to a culture of socialism for decades. The “privatization” of higher education is by all accounts a global phenomenon. Very few systematic studies of these new trends in private post-secondary education exist to date, although the impact of this development could be far-reaching not only for higher education but also for the social and economic development of many societies in the world. In this paper we attempt to analyze the phenomenon of new private universities in non-Western nations, focusing on the developing world in general, and Asia in particular. What missions have these institutions chosen? Which models are these institutions following? What challenges do they face? How are they coping with their relationship to existing public universities? How are they dealing with tuition and budgetary issues? What sources of funding are they tapping into? How are they dealing with issues of equity, excellence, and access? In the composition of their faculty, student body, and curriculum, are these institutions sufficiently international? How are the funding institutions and universities in the West helping these fledgling universities? Are these trends expected to accelerate in the future? We attempt to answer these questions within the context of a few case studies that reflect the breadth and diversity of this revolutionary growth in post-secondary higher education.
Parent stars of extrasolar planets – XI. Trends with condensation temperature revisited

We report the results of abundance analyses of new samples of stars with planets and stars without detected planets. We employ these data to compare abundance-condensation temperature trends in both samples. We find that stars with planets have more negative trends. In addition, the more metal-rich stars with planets display the most negative trends. These results confirm and extend the findings of Ramirez et al. and Melendez et al., who restricted their studies to solar analogues. We also show that the differences between the solar photospheric and CI meteoritic abundances correlate with condensation temperature.
The Division of Gains from Complementarities in Human-Capital-Intensive Activity

This study uses data from the National Basketball Association to explore organizational mechanisms that affect the division of firm surplus in human-capital-intensive activity. It builds on the idea that reciprocal interdependence among team members creates the potential for complementarity. Complementarity, in turn, translates into higher firm surplus. The division of this surplus is subject to bargaining between the firm owner and labor. We argue that when complementarity increases, the firm owner's share of surplus will grow if interdependence among team members is symmetric. Furthermore, we identify three levers that make complementarity amenable to managerial design: the nature of interaction among team members, the relative dominance of team members, and the composition of a team. We find that greater interaction among team members and higher recruitment of team-oriented individuals are associated with increased complementarity, whereas dominant team members are associated with reduced complementarity. The study contributes to the literature on organization design by extending its implications to the division of surplus in human-capital-intensive activity.
Integrated GDP-Productivity Accounts

Two of the most important statistical tools for analysis of macroeconomics and growth are the national accounts (encompassing gross domestic product, or GDP) and the multifactor productivity (MFP) statistics, which measure output per unit of combined inputs. Although they share a common accounting framework, in the United States these statistics are compiled by separate agencies—the national accounts by the Bureau of Economic Analysis (BEA) and the productivity statistics by the Bureau of Labor Statistics (BLS). Dale W. Jorgenson and J. Steven Landefeld (2006) identified the expansion and improved integration of the nation’s national accounts and productivity statistics as a high priority of their “new architecture” for the US national accounts. Barbara M. Fraumeni, et al. (2006) developed the first steps toward integrating the national accounts with the productivity statistics by describing the conceptual framework, developing illustrative accounts, and describing differences in source data and methods that require resolution. Our paper builds on that work; we develop a prototype integrated production account for the private business sector. We also discuss the issues that arise in extending the integrated production account to the total US economy, including nonmarket government and nonprofit sectors, and provide illustrative accounts for these sectors. Integration of the national accounts with the MFP statistics will provide data users with a Integrated GDP-Productivity Accounts
International linkages and productivity at the plant level: Foreign direct investment, exports, imports and licensing

Abstract Productivity growth may be affected particularly for developing countries by international linkages or technology transfer. We evaluate relationships between productivity and FDI, exports, imports and licensing for Turkish manufacturing plants in the apparel, textiles, and motor vehicles industries. We assess performance premia associated with these international technology transfer channels that control for plant size and location. We then use a structural model to allow for plant-specific input composition and interactions, estimated alternatively by quantile regression and semi-parametric techniques to recognize plant heterogeneity and to accommodate simultaneity and selection issues. Overall, we find that productivity is most closely related to foreign ownership, especially for larger plants and in combination with other forms of technology transfer, followed by exporting and then licensing.
Feminist Theory, Embodiment, and the Docile Agent: Some Reflections on the Egyptian Islamic Revival

In the last two decades one of the key questions that has occupied many feminist theorists is how should issues of historical and cultural specificity inform both the analytics and politics of any feminist project. Although this questioning has resulted in serious attempts at integrating issues of sexual, racial, class, and national difference within feminist theory, questions of religious difference have remained relatively unexplored in this scholarship. The vexed relationship between feminism and religious traditions is perhaps most manifest in discussions on Islam. This is due in part to the historically contentious relationship that Islamic societies have had with what has come to be called "the West," but in part to the challenges contemporary Islamic movements pose to secular-liberal politics of which feminism has been an integral (if critical) part. In particular, women's active support for a movement that seems to be inimical to their own interests and agendas, at a historical moment when more emancipatory possibilities would appear to be available to women, raises fresh dilemmas for feminists.' In this essay, I will probe some of the conceptual challenges that women's participation in the Islamic movement poses to feminist theorists and gender analysts through an ethnographic account of an urban women's mosque movement that is part of the larger Islamic revival in Cairo, Egypt. In this movement women from a variety of socioeconomic backgrounds provide lessons to each other that focus on the teaching and studying of Islamic scriptures, social practices, and forms of bodily comportment considered germane to the cultivation of the ideal virtuous self.2 Even though Egyptian Muslim women have always had some measure of informal training in piety, the mosque movement represents an unprecedented engagement with scholarly materials and theological reasoning that had to date been the purview of learned men. Movements such as this one, if they do not provoke a yawning boredom among secular intellectuals, certainly conjure up a whole host of uneasy associations such as fundamentalism, the subjugation of women, social conservatism, reactionary atavism,
Commitment in sequential auctioning: advance listings and threshold prices

This paper models sequential auctioning of two perfect substitutes by a strategic seller, who learns about demand from the first-auction price. The seller holds the second auction only when the remaining demand is strong enough to cover her opportunity cost. Bidding in anticipation of such a contingent future auction is characterized, including a sufficient condition for existence of an invertible (increasing symmetric pure-strategy) bidding equilibrium that facilitates the seller’s learning. A unique invertible bidding equilibrium exists for the Dutch auction format, but only when the second auction is sufficiently discounted by the bidders. In the equilibrium, high-valuation bidders shade their bids down as if the second auction were guaranteed. To counter such strategic bidding, the seller would value ex-ante commitment to hold the second auction less often. Three forms of such commitment are analyzed: commitment to list future auctions in advance, commitment to not hold the second auction unless the first price exceeds a publicly announced threshold, and commitment to a reserve-price in the second auction.
An unexpected retro-aldol–aldol in the AB-ring in the synthesis of (±)-arisugacin A

Abstract Endeavors including an unexpected retro-aldol–aldol process that proved to be critical for our eventual total synthesis of arisugacin A are described here.
Product Improvement and Technological Tying in a Winner-Take-All Market

In a winner-take-all duopoly market for systems in which firms invest to improve their products, a vertically integrated monopoly supplier of an essential system component may have an incentive to advantage itself by technological tying; that is, by designing the component to work better in its own system. If the vertically integrated firm is prevented from technologically tying, then there is an equilibrium in which the more efficient firm invests and serves the entire market. However, another equilibrium may exist in which the less efficient firm invests and captures the market. Technological tying enables a vertically integrated firm to foreclose its rival. The welfare implications of technological tying are ambiguous and depend on the asymmetric qualities of the system suppliers and on equilibrium selection.
On participation games with complete information

We analyze a class of two-candidate voter participation games under complete information that encompasses as special cases certain public good provision games. We characterize the Nash equilibria of these games as stationary points of a non-linear programming problem, the objective function of which is a Morse function (onethat does not admit degenerate critical points) for almost all costs of participation. We use this fact to establish that, outside a closed set of measure zero of participation costs, all equilibria of these games are regular (an alternative to the result of De Sinopoli and Iannantuoni in Econ Theory 25(2):477–486, 2005). One consequence of regularity is that the equilibria of these games are robust to the introduction of (mild) incomplete information. Finally, we establish the existence of monotone Nash equilibria, such that players with higher participation cost abstain with (weakly) higher probability.
Amendments to Organizational Theorizing

Somerset Maugham has written a chilling description that applies to many social scientists. It reads, "She plunged into a sea of platitudes, and with the powerful breast stroke of a channel swimmer made her confident way towards the white cliffs of the obvious" (19, p. 174). More often than not most of us stroke powerfully toward the white cliffs of the obvious. In this article several ways will be suggested in which we can change ways of theorizing, improve theories, and discover something besides the obvious. The argument, in a nutshell, is this: If you want to improve organizational theory, quit studying organizations. Nothing special happens in organizations that does not also happen elsewhere in a more visible form. The problem then is to locate these "elsewheres"and know what to do with them. If this can be done, then it may be possible to improve the theories; if the theories can be improved, then when finally an attempt is made to understand organizations, for once it may prove to be the case that predictions work. It seems odd to tout the importance of organizational theory by claiming that people are never outside of organizations; yet, having said that, organizational scholars then choose the most opaque instance conceivable in which to gather data, the big business organization. Tackling such an opaque unit has some clear and demonstrable effects on the concepts that they become attached to; and there is reason to believe these effects have
Single isolated macromolecules at surfaces

A new class of direct experiments has begun to address the structure, dynamics, and chemical responsiveness of isolated macromolecules at the solid-liquid interface. New fluorescence-based and atomic force microscopy-based methods provide the needed sensitivity, which formerly was unavailable. The initial findings have begun to pose a family of new questions that are practical as well as fundamental. Directions of research opportunity are surveyed. © 2001 Elsevier Science Ltd. All rights reserved.
Vertex operators for AdS3 background with Ramond-Ramond flux

In order to study vertex operators for the Type IIB superstring on AdS space, we derive supersymmetric constraint equations for the vertex operators in AdS3 × S3 backgrounds with Ramond-Ramond flux, using Berkovits-Vafa-Witten variables. These constraints are solved to compute the vertex operators and show that they satisfy the linearized D = 6, N = (2,0) equations of motion for a supergravity and tensor multiplet expanded around the AdS3 × S^3 spacetime.
Essential Spectrum of the Linearized 2D Euler Equation and Lyapunov–Oseledets Exponents

The linear stability of a steady state solution of 2D Euler equations of an ideal fluid is being studied. We give an explicit geometric construction of approximate eigenfunctions for the linearized Euler operator L in vorticity form acting on Sobolev spaces on two dimensional torus. We show that each nonzero Lyapunov–Oseledets exponent for the flow induced by the steady state contributes a vertical line to the essential spectrum of L. Also, we compute the spectral and growth bounds for the group generated by L via the maximal Lyapunov–Oseledets exponent. When the flow has arbitrarily long orbits, we show that the essential spectrum of L on L2 is the imaginary axis.
The tide of computer technology

Advances in computer technology mark the beginning of an information revolution which will provide new challenges for human factors. Some of the new application areas that need to be considered include education, the working environment, and consumer services. Professional implications of computer technology for the Human Factors Society involve technical information exchange, professional training, and public awareness.
Robust Estimation of Inequality from Binned Incomes

Researchers often estimate income inequality by using data that give only the number of cases (e.g., families or households) whose incomes fall in “bins” such as $ 0 to $9,999, $10,000 to $14,999, . . . , ≥$200,000. We find that popular methods for estimating inequality from binned incomes are not robust in small samples, where popular methods can produce infinite, undefined, or arbitrarily large estimates. To solve these and other problems, we develop two improved estimators: a robust Pareto midpoint estimator (RPME) and a multimodel generalized beta estimator (MGBE). In a broad evaluation using U.S. national, state, and county data from 1970 to 2009, we find that both estimators produce very good estimates of the mean and Gini coefficient but less accurate estimates of the Theil index and mean log deviation. Neither estimator is uniformly more accurate, but the RPME is much faster, which may be a consideration when many estimates must be obtained from many data sets. We have made the methods available a...
The Migration Response to Increasing Temperatures

Climate change, especially the warming trend experienced in recent years by several countries, could affect agricultural productivity. As a consequence the income of rural populations will change, and with it the incentives for people to remain in rural areas. Using data from 115 countries between 1960 and 2000, we analyze the effect of differential warming trends across countries on the probability of either migrating out of the country or from rural to urban areas. We find that higher temperatures in middle-income economies increased migration rates to urban areas and to other countries. In poor countries, higher temperatures reduced the probability of migration to cities and to other countries, consistently with the presence of severe liquidity constraints. In middle-income countries, migration represents an important margin of adjustment to global warming, potentially contributing to structural change and even increasing income per worker. Such a mechanism, however, does not seem to work in poor economies.
Operator Sequence Alters Gene Expression Independently of Transcription Factor Occupancy in Bacteria

A canonical quantitative view of transcriptional regulation holds that the only role of operator sequence is to set the probability of transcription factor binding, with operator occupancy determining the level of gene expression. In this work, we test this idea by characterizing repression in vivo and the binding of RNA polymerase in vitro in experiments where operators of various sequences were placed either upstream or downstream from the promoter in Escherichia coli. Surprisingly, we find that operators with a weaker binding affinity can yield higher repression levels than stronger operators. Repressor bound to upstream operators modulates promoter escape, and the magnitude of this modulation is not correlated with the repressor-operator binding affinity. This suggests that operator sequences may modulate transcription by altering the nature of the interaction of the bound transcription factor with the transcriptional machinery, implying a new layer of sequence dependence that must be confronted in the quantitative understanding of gene expression.
Identification of nonpeptidic small-molecule inhibitors of interleukin-2

Abstract The identification, design, and synthesis of a series of novel sulfamide- and urea-based small-molecule antagonists of the protein–protein interaction IL-2/IL-2Rα are described. Installation of a furan carboxylic acid fragment onto a low-micromolar sulfamide resulted in a 23-fold improvement in activity, providing a sub-micromolar, nonpeptidic IL-2 inhibitor (IC50 = 0.60 μM).
The irregular set for maps with the specification property has full topological pressure

Let (X, d) be a compact metric space, f : X ↦ X be a continuous map with the specification property and ϕ : X ↦ ℝ a continuous function. We consider the set of points for which the Birkhoff average of ϕ does not exist (which we call the irregular set for ϕ) and show that this set is either empty or carries full topological pressure (in the sense of Pesin and Pitskel see, for example [Y.B. Pesin, Dimension Theory in Dimensional Systems: Contemporary Views and Applications, University of Chicago Press, Chicago, 1997]). We formulate various equivalent natural conditions on ϕ that completely describe when the latter situation holds and give examples of interesting systems to which our results apply but were not previously known. As an application, we show that for a suspension flow over a continuous map with specification, the irregular set carries full topological entropy.
Car ownership, employment, and earnings

Abstract We assess whether the positive relationship between car ownership and employment outcomes reflects a causal effect of auto ownership. We match state-level data on car insurance premiums and gas taxes to a microdata sample containing information on car-ownership and employment outcomes. In OLS regressions that control for observable covariates, we find large differences in employment rates, weekly hours worked, and hourly earnings between those with and without cars. Instrumenting for car ownership with insurance and gas taxes yields estimates of the employment and hours effects that are quite close to the OLS estimates. Concerning wages, instrumenting eliminates the positive impact of auto ownership.
Fabrication and properties of gallium metallic photonic crystals

Abstract Gallium metallic photonic crystals with 100% filling factor have been fabricated via infiltration of liquid gallium into opals of 300-nm silica spheres using a novel high pressure–high temperature technique. The electrical resistance of the Ga-opal crystals was measured at temperatures from 10 to 280 K. The data obtained show that Ga-opal crystals are metallic network with slightly smaller temperature coefficient of resistivity than that for bulk gallium. Optical reflectivity of bulk gallium, plain opal and several Ga-opal crystals were measured at photon energies from 0.3 to 6 eV. A pronounced photonic stop band in the visible spectral range was found in both the plain and Ga infiltrated opals. The reflectivity spectra also show increase in reflectivity below 0.6 eV; which we interpret as a significantly lower effective plasma frequency of the metallic mesh in the infiltrated opal compare to the plasma frequency in the pure metal.
Job Shop Scheduling with Unit Processing Times

We consider randomized algorithms for the preemptive job shop problem, or equivalently, the case in which all operations have unit length. We give an α-approximation for the case of two machines where α < 1.45, an improved approximation ratio of O(log m/log log m) for an arbitrary number m of machines, and the first (2 + e)-approximation for a constant number of machines. The first result is via an approximation algorithm for a string matching problem that is of independent interest.
Synthesis, structure, and optical properties of CsU2(PO4)3

CsU2(PO4)3 was synthesized in highest yield by the reaction in a fused-silica tube of U, P, and Se in a CsCl flux at 1273 K. It crystallizes with four formula units in space group P21/n of the monoclinic system in a new structure type. The structure of CsU2(PO4)3 is composed of U and Cs atoms coordinated by PO4� units in distorted octahedral arrangements. Each U atom corner shares with six PO4 � units. Each
Tail Current-Shaping to Improve Phase Noise in LC Voltage-Controlled Oscillators

This paper introduces a tail current-shaping technique in LC-VCOs to increase the amplitude and to reduce the phase noise while keeping the power dissipation constant. The tail current is made large when the oscillator output voltage reaches its maximum or minimum value and when the sensitivity of the output phase to injected noise is the smallest; the tail current is made small during the zero crossings of the output voltage when the phase noise sensitivity is large. The phase noise contributions of the active devices are decreased and the VCO has a larger oscillation amplitude and thus better DC to RF conversion compared to a standard VCO with equal power dissipation. A circuit design to implement tail current-shaping is presented that does not dissipate any extra power, does not use additional (noisy) active devices and occupies a small area. The operation and performance of the presented circuit is extensively analyzed and compared to an ideal pulse biased technique. The presented analysis is confirmed by measurement results of two 2-GHz differential nMOS VCOs fabricated in 0.25-mum BiCMOS process
Pirational choice: The economics of infamous pirate practices

Abstract This paper investigates the economics of infamous pirate practices. Two closely related economic theories—the theory of signaling and the theory of reputation building—explain these practices. First, I examine the pirate flag, “Jolly Roger,” which pirates used to signal their identity as unconstrained outlaws, enabling them to take prizes without costly conflict. Second, I consider how pirates combined heinous torture, public displays of “madness,” and published advertisement of their fiendishness to establish a reputation that prevented costly captive behaviors. Pirates’ infamous practices reduced their criminal enterprise’s costs and increased its revenues, enhancing the profitability of life “on the account.”
Double-gate SOI devices for low-power and high-performance applications

Double-gate (DG) transistors have emerged as promising devices for nano-scale circuits due to their better scalability compared to bulk CMOS. Among the various types of DG devices, quasi-planar SOI FinFETs are easier to manufacture compared to planar double-gate devices. DG devices with independent gates (separate contacts to back and front gates) have recently been developed. DG devices with symmetric and asymmetric gates have also been demonstrated. Such device options have direct implications at the circuit level. Independent control of front and back gate in DG devices can be effectively used to improve performance and reduce power in sub-50nm circuits. Independent gate control can be used to merge parallel transistors in non-critical paths. This results in reduction in the effective switching capacitance and hence power dissipation. We show a variety of circuits in logic and memory that can benefit from independent gate operation of DG devices. As examples, we show the benefit of independent gate operation in circuits such as dynamic logic circuits, Schmitt triggers, sense amplifiers, and SRAM cells. In addition to independent gate option, we also investigate the usefulness of asymmetric devices and the impact of width quantization and process variations on circuit design.
Convenient syntheses of N-[2-(2-hydroxyethoxy)ethyl]-substituted polyaza-crown ethers and cyclams without the need for a hydroxy blocking group

Abstract Short three or four step syntheses of N-[2-(2-hydroxyethoxy)ethyl]-substituted polyaza-crowns and cyclams without the need for a hydroxy blocking group are presented. Cyclization of a hydroxy-substituted diamine took place on the two amine nitrogen atoms because sodium carbonate does not ionize the hydroxy group.
How Economic Contractions and Expansions Affect Expenditure Patterns

In this study, we attempt to understand how household budget allocations across various expenditure categories change when the economy is in recession or expansion. The common assumption is that a household’s tastes would not change as a function of economic conditions and therefore any adjustments in expenditure patterns during economic contractions/expansions would simply be due to changes in the consumption budget. Standard economic models translate these budgetary effects into lateral movements along a set of fixed Engel curves, which relate category expenditure shares to total expenditures. We propose and test a conceptual framework based on the notion of relative consumption, which prescribes that, for any given total consumption budget, expenditure shares for positional goods/services will decrease during a recession, while shares for nonpositional goods/services will increase (i.e., shifting the entire Engel curve upward or downward, depending on the nature of the expenditure category and the economic conditions).
Are the Nuclei of Seyfert 2 Galaxies Viewed Face-On?

We show from modeling the Fe Kα line in the ASCA spectra of four X-ray-bright narrow emission line galaxies (Seyfert types 1.9 and 2) that two equally viable physical models can describe the observed line profile. The first is discussed by Turner et al. and consists of emission from a nearly pole-on accretion disk. The second, which is statistically preferred, is a superposition of emission from an accretion disk viewed at an intermediate inclination of ~48° and a distinct, unresolved feature that presumably originates some distance from the galaxy nucleus. The intermediate inclination is entirely consistent with unified schemes, and our findings challenge recent assertions that Seyfert 2 galaxies are preferentially viewed with their inner regions face-on. We derive mean equivalent widths for the narrow and disk lines of EWN=60 eV and EWD=213 eV, respectively. The X-ray data are well described by a geometry in which our view of the active nucleus intersects and is blocked by the outer edges of the obscuring torus and therefore do not require severe misalignments between the accretion disk and the torus.
Coding sequence density estimation via topological pressure.

We give a new approach to coding sequence (CDS) density estimation in genomic analysis based on the topological pressure, which we develop from a well known concept in ergodic theory. Topological pressure measures the ‘weighted information content’ of a finite word, and incorporates 64 parameters which can be interpreted as a choice of weight for each nucleotide triplet. We train the parameters so that the topological pressure fits the observed coding sequence density on the human genome, and use this to give ab initio predictions of CDS density over windows of size around 66,000 bp on the genomes of Mus Musculus, Rhesus Macaque and Drososphilia Melanogaster. While the differences between these genomes are too great to expect that training on the human genome could predict, for example, the exact locations of genes, we demonstrate that our method gives reasonable estimates for the ‘coarse scale’ problem of predicting CDS density. Inspired again by ergodic theory, the weightings of the nucleotide triplets obtained from our training procedure are used to define a probability distribution on finite sequences, which can be used to distinguish between intron and exon sequences from the human genome of lengths between 750 and 5,000 bp. At the end of the paper, we explain the theoretical underpinning for our approach, which is the theory of Thermodynamic Formalism from the dynamical systems literature. Mathematica and MATLAB implementations of our method are available at http://sourceforge.net/projects/topologicalpres/.
Intermolecular [4+2] Cycloadditions of a Reactive Cyclopentadienone

A reactive cyclopentadienone gives Diels–Alder cycloadducts with a variety of dienes in high yield and often with extremely high levels of regio- and stereoselectivity. The high degree of generality of this reaction suggests it will be of use in organic synthesis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
The anarchy of numbers : aid, development, and cross-country empirics

The recent literature contains many stories of how foreign aid affects economic growth. Aid raises growth in countries with good policies, or with difficult economic environments, or outside the tropics, or on average but with diminishing returns. The diversity of the results suggests that many are fragile. Seven important aid-growth papers are tested for robustness, using 14 minimally arbitrary tests deriving mainly from differences among the studies themselves. This approach investigates the importance of potentially arbitrary specification choices while minimizing the arbitrariness in testing choices. All of the results appear fragile, especially to sample expansion.
Online scheduling on identical machines using SRPT

Due to its optimality on a single machine for the problem of minimizing average flow time, Shortest-Remaining-Processing-Time (SRPT) appears to be the most natural algorithm to consider for the problem of minimizing average flow time on multiple identical machines. It is known that SRPT achieves the best possible competitive ratio on multiple machines up to a constant factor. Using resource augmentation, SRPT is known to achieve total flow time at most that of the optimal solution when given machines of speed 2 − 1/m. Further, it is known that SRPT's competitive ratio improves as the speed increases; SRPT is s-speed 1/s-competitive when s ≥ 2--1/m.However, a gap has persisted in our understanding of SRPT. Before this work, the performance of SRPT was not known when SRPT is given (1 + e)-speed when 0 0. We complement this by showing that SRPT is (1 + e)-speed O(1/e2)-competitive for the objective of minimizing the lk-norms of flow time on m identical machines. Both of our results rely on new potential functions that capture the structure of SRPT. Our results, combined with previous work, show that SRPT is the best possible online algorithm in essentially every aspect when migration is permissible.