cssi/SciSciGPT-SciSciNet huggingface dataset:
Inferring Admixture Histories of Human Populations Using Linkage Disequilibrium

Long-range migrations and the resulting admixtures between populations have been important forces shaping human genetic diversity. Most existing methods for detecting and reconstructing historical admixture events are based on allele frequency divergences or patterns of ancestry segments in chromosomes of admixed individuals. An emerging new approach harnesses the exponential decay of admixture-induced linkage disequilibrium (LD) as a function of genetic distance. Here, we comprehensively develop LD-based inference into a versatile tool for investigating admixture. We present a new weighted LD statistic that can be used to infer mixture proportions as well as dates with fewer constraints on reference populations than previous methods. We define an LD-based three-population test for admixture and identify scenarios in which it can detect admixture events that previous formal tests cannot. We further show that we can uncover phylogenetic relationships among populations by comparing weighted LD curves obtained using a suite of references. Finally, we describe several improvements to the computation and fitting of weighted LD curves that greatly increase the robustness and speed of the calculations. We implement all of these advances in a software package, ALDER, which we validate in simulations and apply to test for admixture among all populations from the Human Genome Diversity Project (HGDP), highlighting insights into the admixture history of Central African Pygmies, Sardinians, and Japanese.
Female Labor Force Participation: The Origin of Black and White Differences, 1870 and 1880

Although white women have only recently entered the work force, their black counterparts have participated throughout American history. Differences between their rates of participation have been recorded only for the post-1890 period and analyzed only for the post-1940 period due to a lack of available data. To remedy this deficiency my work explores female labor supply at the dawn of emanicipation, 1870 and 1880, in seven southern cities, using data drawn from the manuscripts of the population census. Probit regression techniques demonstrate that economic and demographic variables explain only part of the difference between black and white women and, as in the findings of contemporary research, race is shown to be an important factor. Several explanations are discussed, in particular one relying on socialization differences which are termed a “legacy of slavery.”
Electron Beam Machining of Nanometer-Sized Tips from Multiwalled Boron Nitride Nanotubes

We report here that high energy electron irradiation of multiwalled boron nitride nanotubes can be used to form sharp, crystalline, conical tips, or to cut boron nitride nanotubes by controlling the electron beam size. Electron beam cutting is observed when a focused electron beam with a diameter much smaller than the tube diameter is used. The tip formation is observed when a shaped, disklike, electron beam is used to irradiate the tube; the diameter of the beam in this case is similar to the tube diameter. In situ electron microscopy observation shows that the tip formation effect is driven by layer peeling and the collapse of the inner walls of the nanotube. This is very different from the formation of nanoarches observed during cutting. The combination of shaping and cutting can be used to fabricate atomically sharp tips for field emitters, nanoimaging, and manipulations.
New estimates for solutions of Lyapunov equations

Results for estimating the solution of differential and algebraic Lyapunov matrix equations are obtained, and some of the well-known results are generalized.
Risk premia and term premia in general equilibrium

Abstract The equity premium consists of a term premium reflecting the longer maturity of equity relative to short-term bills, and a risk premium reflecting the stochastic nature of equity payoffs and the deterministic nature of payoffs on riskless bills. This paper analyzes term premia and risk premia in a general equilibrium model with catching up with the Joneses preferences and a novel formulation of leverage. Closed-form solutions for moments of asset returns are derived. First-order approximations illustrate the effects of parameters and provide an algorithm to match the means and variances of the riskless rate and the rate of return on equity.
Accretion to stars with non-dipole magnetic fields

ABSTRACT Disc accretion to a rotating star with a non-dipole magnetic ﬁeld is investigatedfor the ﬁrst time in full three-dimensional (3D) magnetohydrodynamic (MHD) simula-tions. We investigated the cases of (1) pure dipole, (2) pure quadrupole, and (3) dipoleplus quadrupole ﬁelds. The quadrupole magnetic moment D is taken to be parallelto the dipole magnetic moment µ, and both are inclined relative to the spin axis ofthe star Ω at an angle Θ. Simulations have shown that in each case the structure ofthe funnel streams and associated hot spots on the surface of the star have speciﬁcfeatures connected with the magnetic ﬁeld conﬁguration. In the pure dipole case mat-ter accretes in two funnel streams which form two arch-like spots near the magneticpoles. In the case of a pure quadrupole ﬁeld, most of the matter ﬂows through thequadrupole “belt” forming a ring-shaped hot region on the magnetic equator. In thecase of a dipole plus quadrupole ﬁeld, magnetic ﬂux in the northern magnetic hemi-sphere is larger than that in the southern, and the quadrupole belt and the ring aredisplaced to the south. The stronger the quadrupole, the closer the ring is to the mag-netic equator. At suﬃciently large Θ, matter also ﬂows to the south pole, forming a hotspot near the pole. The light curves have a variety of diﬀerent features which makesit diﬃcult to derive the magnetic ﬁeld conﬁguration from the light curves. There arespeciﬁc features which are diﬀerent in cases of dipole and quadrupole dominated mag-netic ﬁeld: (1) Angular momentum ﬂow between the star and disc is more eﬃcient inthe case of the dipole ﬁeld; (2) Hot spots are hotter and brighter in case of the dipoleﬁeld because the matter accelerates over a longer distance compared with the ﬂow ina quadrupole case.Key words: accretion, accretion discs - magnetic ﬁelds - MHD - stars: magneticﬁelds.
Derived Categories and Zero-Brane Stability

We define a particular class of topological field theories associated to open strings and prove the resulting D-branes and open strings form the bounded derived category of coherent sheaves. This derivation is a variant of some ideas proposed recently by Douglas. We then argue that any 0-brane on any Calabi-Yau threefold must become unstable along some path in the Kahler moduli space. As a byproduct of this analysis we see how the derived category can be invariant under a birational transformation between Calabi-Yaus.
The impact of message-buffer alignment on communication performance

Of the many factors that contribute to communication performance, perhaps one of the least investigated is that of message-buffer alignment. Although the generally accepted practice is to page-align buffer memory for best performance, our studies show that the actual relationship of buffer alignment to communication performance cannot be expressed with such a simple formula. This paper presents a case study in which porting a simple network performance test from one language to another resulted in a large performance discrepancy even though both versions of the code consist primarily of calls to messaging-layer functions. Careful analysis of the two code versions revealed that the discrepancy relates to the alignment in memory of the message buffers. Further investigation revealed some surprising results about the impact of message-buffer alignment on communication performance: (1) different networks and node architectures prefer different buffer alignments; (2) page-aligned memory does not always give the best possible performance, and, in some cases, actually yields the worst possible performance; and, (3) on some systems, the most significant factor affecting network performance is the relative alignment of send and receive buffers with respect to each other.
Robust Failure Compensation for a Morphing Aircraft Model Using a Probabilistic Approach

We present a probabilistic robust control design for a morphing aircraft model subject to uncertain actuator failure. The morphing aircraft model has multiple distributed arrays of shape-change devices that are used to generate moments for stabilization and low-rate maneuvering, augmenting conventional control surfaces. Each actuator operates at either on or off state; failure of each actuator could cause uncertainty in the applied control input. We characterize the morphing aircraft's actuation failure in a probabilistic way. In particular, each shape-change device within an actuator array is assumed to have certain probability to fail while devices from different arrays may have different failure probabilities. Consequently, we model the uncertain actuator failure as a random parametric uncertainty in the input matrix of the morphing aircraft model. A probabilistic robust explicit-model-following controller is then designed to stabilize the closed-loop system and to satisfy tracking performance subject to uncertain actuator failure. Simulation results are presented and evaluated for the application of this probabilistic robust failure compensation design to lateral dynamics of an Innovative Control Effector morphing aircraft model
Spousal mobility and earnings.

An important finding in the literature on migration has been that the earnings of married women typically decrease with a move, while the earnings of married men often increase with a move, suggesting that married women are more likely to act as the “trailing spouse.” This article considers a related but largely unexplored question: what is the effect of having an occupation that is associated with frequent migration on the migration decisions of a household and on the earnings of the spouse? Further, how do these effects differ between men and women? The Public Use Microdata Sample from the 2000 U.S. decennial census is used to calculate migration rates by occupation and education. The analysis estimates the effects of these occupational mobility measures on the migration of couples and the earnings of married individuals. I find that migration rates in both the husband’s and wife’s occupations affect the household migration decision, but mobility in the husband’s occupation matters considerably more. For couples in which the husband has a college degree (regardless of the wife’s educational level), a husband’s mobility has a large, significant negative effect on his wife’s earnings, whereas a wife’s mobility has no effect on her husband’s earnings. This negative effect does not exist for college-educated wives married to non-college-educated husbands.
Effects of dissolved gases on subcooled flow boiling from small heated regions with and without streamwise concave curvature

Coolants such as fluorocarbon liquids usually contain high levels of dissolved gases. When heated, these gases are liberated from the liquid; if the liquid is boiling, these gases may influence the supply of liquid to the boiling surface. In this study, the effects of dissolved air in perfluorinated hydrocarbon, FC-72, on flow boiling heat transfer characteristics were experimentally investigated over a range of heat flux from the onset of nucleate boiling (ONB) to the critical heat flux (CHF). The experiments were conducted in both straight and curved channels. The boiling surface was a 3 mm/spl times/3 mm patch located on the channel wall. In the curved flow, it was located at the 90/spl deg/ position of a U-bend on the concave wall. Gas content was varied from 1.16/spl times/10/sup -5/ to 2.55/spl times/10/sup -3/ mole/mole, velocity ranged from 0.8 to 6.9 m/s, and pressure was controlled to either 1.41 or 1.92 atm. Subcooling, based on total pressure, was maintained at 27.5/spl deg/C. The data show that reduction of incipience superheat at ONB due to dissolved gases under these forced-convection conditions is much less than with pool boiling or low-velocity flow boiling. Boiling curves for gassy and degassed cases differ at low heat flux levels but merge at higher heat fluxes. The merging may indicate that the near-wall liquid layer is being degassed at higher heat fluxes. Though the high-heat-flux portions of the boiling curves were apparently unaffected by the content of dissolved gas in the approaching liquid stream, the critical heat flux was decreased by as much as 10%. Explanations of this behavior are presented in terms of the two mechanisms for the liquid supply to the macrolayer. >
The concept of a generalized constraint - a bridge from natural languages to mathematics

The concept of a generalized constraint was introduced close to two decades ago. For a number of years, it lay dormant and unused. But then, in the mid-nineties, it found an important application as a basis for the methodology of computing with words (CW). More recently, an idea which began to crystallize is that the concept of a generalized constraint may serve an important function as a bridge from natural languages to mathematics. In the role, it may find many applications, ranging from formalization of legal reasoning to enhancement of Web intelligence and natural language understanding. The basis for the expectation is that as we move further into the age of machine intelligence and mechanized reasoning, the problem of natural language understanding looms larger and larger in importance and visibility. Traditional approaches to natural language understanding are based on classical, Aristotelian, bivalent logic. So far, use of traditional approaches has met with limited successes. The principal problem is that, basically, natural languages are systems for describing perceptions, and as such are intrinsically imprecise in ways that put them beyond the reach of bivalent logic and probability theory.
Advances in multichannel MultiGbytes/s bit-parallel WDM single fiber link

For ultra-high-speed single media parallel interconnects, an all optical single fiber WDM format of transmitting parallel bits rather than a fiber ribbon format-where parallel bits are sent through corresponding parallel fibers in a ribbon format, can be the media of choice. Here, we discuss the realization of a multi-km/spl times/Gb/s bit-parallel WDM (BP-WDM) single fiber link. The distance-speed product of this single fiber link is more than several orders of magnitude higher than that of a fiber ribbon link. The design of a 12 b parallel channels WDM system operating at 1 Gb/s per channel rate through a single fiber is first presented. Experimental results for a two channel system operating at that rate are given. Further improvement of distance-speed product for the BP-WDM link can be obtained with JPL's newly developed 20 Gb/s per channel laser diode array transmitter. Also, new computer simulation results on how a large amplitude co-propagating pulse may induce pulse compression on all the co-propagating data pulses, thereby improving the shaping of these pulses for a WDM system, are presented and discussed. The existence of WDM solitons is also shown.
Relative income concerns and the rise in married women's employment

Abstract We ask whether women's decisions to be in the workforce may be affected by the decisions of other women in ways not captured by standard models. We develop a model that augments the simple neoclassical framework by introducing relative income concerns into women's (or families') utility functions. In this model, the entry of some women into paid employment can spur the entry of other women, independently of wage and income effects. We show that relative income concerns can help to explain why, over some periods, women's employment rose faster than can be accounted for by the simple neoclassical model. We test the model by asking whether women's decisions to seek paid employment depend on the employment or incomes of other women with whom relative income comparisons might be important, including sisters and sisters-in-law. The evidence is largely supportive of the relative income hypothesis.
Ultrafast Dynamics of 1,3-Cyclohexadiene in Highly Excited States

The ultrafast dynamics of 1,3-cyclohexadiene has been investigated via structurally sensitive Rydberg electron binding energies and shown to differ upon excitation to the 1B state and the 3p Rydberg state. Excitation of the molecule with 4.63 eV photons into the ultrashort-lived 1B state yields the well-known ring opening to 1,3,5-hexatriene, while a 5.99 eV photon lifts the molecule directly into the 3p-Rydberg state. Excitation to 3p does not induce ring opening. In both experiments, time-dependent shifts of the Rydberg electron binding energy reflect the structural dynamics of the molecular core. Structural distortions associated with 3p-excitation cause a dynamical shift in the p𝑥- and p𝑦-binding energies by 10 and 26 meV/ps, respectively, whereas after excitation into 1B, more severe structural transformations along the ring-opening coordinate produce shifts at a rate of 40 to 60 meV/ps. The experiment validates photoionization-photoelectron spectroscopy via Rydberg states as a powerful technique to observe structural dynamics of polyatomic molecules.
A Note on the Adjustment of Fourfold Tables for "Curvilinearity"

In Psychometric Methods Guilford reports a method of correcting fourfold tables for “curvilinearity” for the purpose of computing tetrachoric correlations. It is pointed out here that the notion of correcting such tables is erroneous in view of the restrictions on the table and the nature of the tetrachoric correlation. It is also demonstrated that the “correction” can, and in common cases will, have a profound effect on the value of the observed correlation.
Tiling simply connected regions with rectangles

Abstract In 1995, Beauquier, Nivat, Remila, and Robson showed that tiling of general regions with two bars is NP-complete, except for a few trivial special cases. In a different direction, in 2005, Remila showed that for simply connected regions by two rectangles, the tileability can be solved in quadratic time (in the area). We prove that there is a finite set of at most 106 rectangles for which the tileability problem of simply connected regions is NP-complete, closing the gap between positive and negative results in the field. We also prove that counting such rectangular tilings is #P-complete, a first result of this kind.
The Silicon Valley-Hsinchu Connection: Technical Communities and Industrial Upgrading

Silicon Valley in California and the Hsinchu-Taipei region of Taiwan are among the most frequently cited ‘miracles’ of industrialization in the information technology era. Since the region’s transformation from an agricultural valley into the birthplace of the semiconductor industry in the 1950s, Silicon Valley firms have pioneered a wide range of technology-related industries. The regional economy has adapted flexibly to fast changing markets, and local producers continue to define the state-of-the-art in successive generations of technology—from semiconductor equipment, personal and handheld computers, and networking hardware and software, to biotechnology, multimedia software, and internet-related infrastructure and services. Taiwan’s technology achievements are more recent, but no less impressive. The Taipei area, which served as a source of low cost labor for consumer electronics production as late as the 1970s, is known today for the speed and flexibility of its personal computer manufacturers. These firms dominate the markets for a large and growing range of computer-rela ted products, from motherboards and monitors to optical scanners and power supplies. Meanwhile, the Hsinchu Science-based Industrial Park, established in 1980, is now a state-of-the art manufacturer of semiconductor s, on par with the world market leaders in the US and Japan. Taiwan’s total information technology output is now greater than that of larger nations like Korea; in fact it is larger than the output of Germany and France combined (Anderson 1998.)
Feasibility of near-field ODR imaging of multi-GeV electron beams at CEBAF

We have evaluated the feasibility of using the optical diffraction radiation (ODR) generated as a 1- to 6-GeV CW electron beam passes nearby the edge of a single metal conducting plane as a nonintercepting (NI) relative beam size monitor for CEBAF. Previous experiments were successfully done using near-field imaging on the lower-current, 7-GeV beam at APS, and an analytical model was developed for near-field imaging. Calculations from this model indicate sufficient beam size sensitivity in the ODR profiles for beam sizes in the 30- to 50- micron regime as found in the transport lines of CEBAF before the experimental targets. With anticipated beam currents of 100 muA, the ODR signal from the charge integrated over the video field time should be -500 times larger than in the APS case. These signal strengths will allow a series of experiments to be done on beam energy dependencies, impact parameters, polarization effects, and wavelength effects that should further elucidate the working regime of this technique and test the model. Plans for the diagnostics station that will provide reference optical transition radiation (OTR) images will also be described.
Unfolding Manhattan Towers

We provide an algorithm for unfolding the surface of any orthogonal polyhedron that falls into a particular shape class we call Manhattan Towers, to a nonoverlapping planar orthogonal polygon. The algorithm cuts along edges of a 4x5x1 refinement of the vertex grid.
Catalytic hydroamination of alkynes and norbornene with neutral and cationic tantalum imido complexes.

Several tantalum imido complexes have been synthesized and shown to efficiently catalyze the hydroamination of internal and terminal alkynes. An unusual hydroamination/hydroarylation reaction of norbornene catalyzed by a highly electrophilic cationic tantalum imido complex is also reported. Factors affecting catalyst activity and selectivity are discussed along with mechanistic insights gained from stoichiometric reactions.
A BRACKET POLYNOMIAL FOR GRAPHS, III: VERTEX WEIGHTS

In earlier work the Kauffman bracket polynomial was extended to an invariant of marked graphs, i.e., looped graphs whose vertices have been partitioned into two classes (marked and not marked). The marked-graph bracket polynomial is readily modified to handle graphs with weighted vertices. We present formulas that simplify the computation of this weighted bracket for graphs that contain twin vertices or are constructed using graph composition, and we show that graph composition corresponds to the construction of a link diagram from tangles.
Regulation of NF-κB by NSD1/FBXL11-dependent reversible lysine methylation of p65

NF-κB, a central coordinator of immune and inflammatory responses, must be tightly regulated. We describe a NF-κB regulatory pathway that is driven by reversible lysine methylation of the p65 subunit, carried out by a lysine methylase, the nuclear receptor–binding SET domain-containing protein 1 (NSD1), and a lysine demethylase, F-box and leucine-rich repeat protein 11 (FBXL11). Overexpression of FBXL11 inhibits NF-κB activity, and a high level of NSD1 activates NF-κB and reverses the inhibitory effect of FBXL11, whereas reduced expression of NSD1 decreases NF-κB activation. The targets are K218 and K221 of p65, which are methylated in cells with activated NF-κB. Overexpression of FBXL11 slowed the growth of HT29 cancer cells, whereas shRNA-mediated knockdown had the opposite effect, and these phenotypes were dependent on K218/K221 methylation. In mouse embryo fibroblasts, the activation of most p65-dependent genes relied on K218/K221 methylation. Importantly, expression of the FBXL11 gene is driven by NF-κB, revealing a negative regulatory feedback loop. We conclude that reversible lysine methylation of NF-κB is an important element in the complex regulation of this key transcription factor.
Role of Nonfluorescent Twisted Intramolecular Charge Transfer State on the Photophysical Behavior of Aminophthalimide Dyes

Photophysical behavior of 4-aminophthalimide and its N,N-dimethyl derivative is studied in a series of solvents. A comparison of the fluorescence properties of the two compounds reveals that they behave quite differently despite their structural similarity. The efficient nonradiative decay of the dimethyl derivative in polar media is interpreted in terms of a nonemitting twisted state. Semiempirical calculations based on the AM1 method have been performed, and the results support the twisting mechanism. Calculations of the ground and excited state profiles as a function of torsion angle provide a clear picture of whether the twisting can influence the photophysical behavior of this class of dyes. The results provide insight into the design of efficient dye systems.
Eigenvalues and forbidden subgraphs I

Abstract Suppose a graph G have n vertices, m edges, and t triangles. Letting λ n ( G ) be the largest eigenvalue of the Laplacian of G and μ n ( G ) be the smallest eigenvalue of its adjacency matrix, we prove that λ n ( G ) ⩾ 2 m 2 - 3 nt m ( n 2 - 2 m ) n , μ n ( G ) ⩽ 3 n 3 t - 4 m 3 nm ( n 2 - 2 m ) , with equality if and only if G is a regular complete multipartite graph. Moreover, if G is K r +1 -free, then λ n ( G ) ⩾ 2 mn ( r - 1 ) ( n 2 - 2 m ) with equality if and only if G is a regular complete r -partite graph.
Large-scale parallel data clustering

Algorithmic enhancements are described that enable large computational reduction in mean square-error data clustering. These improvements are incorporated into a parallel data-clustering tool, P-CLUSTER, designed to execute on a network of workstations. Experiments involving the unsupervised segmentation of standard texture images were performed. For some data sets, a 96 percent reduction in computation was achieved.
Using magnetic resonance microscopy to study the growth dynamics of a glioma spheroid in collagen I: A case study

Background Highly malignant gliomas are characterized by rapid growth, extensive local tissue infiltration and the resulting overall dismal clinical outcome. Gaining any additional insights into the complex interaction between this aggressive brain tumor and its microenvironment is therefore critical. Currently, the standard imaging modalities to investigate the crucial interface between tumor growth and invasion in vitro are light and confocal laser scanning microscopy. While immensely useful in cell culture, integrating these modalities with this cancer's clinical imaging method of choice, i.e. MRI, is a non-trivial endeavour. However, this integration is necessary, should advanced computational modeling be able to utilize these in vitro data to eventually predict growth behaviour in vivo. We therefore argue that employing the same imaging modality for both the experimental setting and the clinical situation it represents should have significant value from a data integration perspective. In this case study, we have investigated the feasibility of using a specific form of MRI, i.e. magnetic resonance microscopy or MRM, to study the expansion dynamics of a multicellular tumor spheroid in a collagen type I gel.
Restructuring Charges and CEO Cash Compensation: A Reexamination

Prior research generally concludes that compensation committees completely shield executive compensation from the effect of restructuring charges on earnings. In contrast, we find that after controlling for the growth in annual inflation‐adjusted CEO cash compensation, compensation committees only partially shield CEO compensation from the adverse effect of restructuring charges on earnings, on average. In further analyses, we identify factors associated with cross‐sectional differences in the extent of shielding. Specifically, we find that compensation committees appear to: (1) completely shield initial and subsequent restructuring charges for CEOs with long tenure, provided that the firm had not recorded a charge in the two immediately prior years; (2) provide no shielding of subsequent restructuring charges taken by short‐tenured CEOs if the firm reported a prior restructuring charge within two years of the current charge; (3) and partially shield the other categories of restructuring charges. Overall,...
Application Experiments: MPPA and FPGA

This paper describes the mapping approach, programmability, and performance of the Ambric Massively Parallel Processor Array (MPPA), and compares these aspects to an FPGA. Two application kernels, a trellis decoder, and n-gram frequency counter, were ported to the Ambric development system and an Altera Stratix II. We find that the mapping strategies to Ambric and FPGAs are similar at the high level, but diverge quite a bit in implementation due to differences in granularity between the basic compute units of the two devices. Both require substantial refactoring from the baseline sequential algorithm. The FPGA proved superior in terms of performance, but the Ambric fares significantly better than the FPGA in programmability and ease of application development.
Creating a Truly Multidisciplinary Entrepreneurial Educational Environment

In our age of technological growth and change, the role of the engineer has evolved from lone specialist to team player, from internally focused to globally aware, from reactionary to entrepreneur. The entrepreneur has created much of our social wealth. The characteristics of the entrepreneur transcend academic disciplines, and social as well as economic status. To foster these characteristics among its students, Lehigh University is developing a multidisciplinary educational environment where entrepreneurial spirit can flourish. Lehigh's academic programs in Integrated Product Development (IPD), Integrated Business and Engineering (IBE), and Integrated Design Arts (IDA) integrate across Engineering, Business and Design Arts through sponsored projects and entrepreneurial teams, or E-Teams, consisting of students, faculty advisors, staff support and company mentors. Project sponsors include the full range from student entrepreneurs and other start-up companies, to established small, medium and large corporations. The multi-level approach to curricular integration includes pre-college outreach, freshman projects, curricula support, capstone projects and graduate projects. The educational environment includes a Campus Center; an entire building designed to support students project teams. This paper will discuss the design and implementation of these programs, our assessment and evaluation methods, lessons learned and future plans for improving this environment.
Dendrimers as guests in molecular recognition phenomena.

Dendrimers are highly branched macromolecules which may engage in host–guest interactions, acting as either hosts or guests; this review is specifically concerned with the binding behavior of dendrimers containing single or multiple guest residues interacting with individual, freely diffusing hosts.
The development and scope of a versatile tandem Stille-oxa-electrocyclization reaction

A palladium-catalyzed tandem Stille-oxa-electrocyclization reaction has been developed for the convergent preparation of highly substituted polycyclic pyran systems. The strategy presented in this letter is an alternative to the known methods for constructing similar pyran systems. The substrate scope of this diastereoselective transformation is explored.
Female leadership raises aspirations and educational attainment for girls: a policy experiment in India.

): Exploiting a randomized natural experiment in India, we show that female leadership influences adolescent girls’career aspirations and educational attainment. A 1993 law reserved leadership positions for women in randomly selected village councils. Using 8453 surveys of adolescents aged 11 to 15 and their parents in 495 villages, we found that, relative to villages in which such positions were never reserved, the gender gap in aspirations closed by 20% in parents and 32% in adolescents in villages assigned a female leader for two election cycles. The gender gap in adolescent educational attainment was erased, and girls spent less time on household chores. We found no evidence of changes in young women’ sl abor market opportunities, which suggests that the impact of women leaders primarily reflects a role model effect.
HPV Vaccine Hesitancy: Findings From a Statewide Survey of Health Care Providers

Abstract Introduction Health care provider recommendations are critical for human papillomavirus (HPV) vaccine uptake. We sought to describe providers' HPV vaccine recommendation practices and explore their perceptions of parental hesitancy. Method A statewide sample (n = 575) of Minnesota health care providers (20% pediatricians, 47% family medicine physicians, and 33% nurse practitioners) completed our online survey in April 2013. Results Only 76% of health care providers reported routinely recommending HPV vaccine for girls ages 11 to 12 years, and far fewer (46%) did so for boys (p Discussion Findings suggest that providers' perceptions of hesitancy may discourage them from routinely recommending the HPV vaccine. Improving providers' self-efficacy to address hesitancy may be important for improving vaccination rates.
Computational Science and Innovation

Simulations – utilizing computers to solve complicated science and engineering problems – are a key ingredient of modern science. The U.S. Department of Energy (DOE) is a world leader in the development of high-performance computing (HPC), the development of applied math and algorithms that utilize the full potential of HPC platforms, and the application of computing to science and engineering problems. An interesting general question is whether the DOE can strategically utilize its capability in simulations to advance innovation more broadly. In this article, I will argue that this is certainly possible.
Testing for ARCH in the presence of a possibly misspecified conditional mean

Abstract Ever since the development of the Autoregressive Conditional Heteroskedasticity (ARCH) model ( Engle, 1982 ), testing for the presence of ARCH has become a routine diagnostic. One popular method of testing for ARCH is T times the R2 from a regression of the squared residuals on p of its lags. This test has been shown to have a lagrange multiplier interpretation and is asymptotically distributed as a χ2(p) random variable. Underlying this test is the assumption of a correctly specified conditional mean. In this paper, we consider the properties of the ARCH test when there is a possibly misspecified conditional mean. Examples of misspecification include omitted variables, structural change, and parameter instability. We show that, in general, misspecification will lead to overrejection of the null hypothesis of conditional homoskedasticity. We demonstrate the use of recursive residuals to improve the fit of a first-stage conditional mean regression. We illustrate these results via Monte Carlo simulations and consider two empirical examples.
Experimental Attenuation of Rectangular Waveguides at Millimeter Wavelengths

The experimental values of attenuation of commercially available rectangular waveguides were determined at frequencies between 25 and 200 GHz with emphasis on high accuracy. They were compared with the theoretical values computed from the dc conductivities, taking into consideration temperature effects, work hardening, size effects, surface roughness, and a room-temperature anomaly of the skin effect. A new way to express the excess attenuation due to these effects was fomulated. Excess ratios of attenuation of coin-silver waveguides were found to be well below the values used in engineering in the past. They can satisfactorily be explained by surface roughness. The normalized excess attenuations of copper guides are higher than those of guides made of silver but lower than cited in the literature.
Model and parameter dependence of heavy quark energy loss in a hot and dense medium

Within the framework of the Langevin equation, we study the energy loss of heavy quarks due to quasi-elastic multiple scatterings in a quark–gluon plasma created by relativistic heavy-ion collisions. We investigate how the initial configuration of the quark–gluon plasma as well as its properties affect the final state spectra and elliptic flow of D-mesons and non-photonic electrons. We find that both the geometric anisotropy of the initial quark–gluon plasma and the flow profiles of the hydrodynamic medium play important roles in the heavy quark energy loss process and the development of elliptic flow. The relative contribution from charm and bottom quarks is found to affect the transverse momentum dependence of the quenching and flow patterns of heavy flavor decay electron; such influence depends on the interaction strength between heavy quarks and the medium.
Shapes and sizes from non-identical-particle correlations

I review the prospects for measuring source characteristics from correlations other than those involving identical pions. Correlations generated from Coulomb and strong interactions are shown to provide remarkable resolving power for determining three-dimensional information, in some cases accessing more detail than can be represented by Gaussian fits.
Feedback control of atomic motion in optical lattices

Summary form only given. Atoms in an optical lattice, though very slow, perform a slight random motion that reflects the non-zero temperature of the trapped atoms. We are proposing a way of reducing such random motion using real-time feedback. The method is related to the stochastic cooling used to transversely cool particle beams. Another stochastic cooling method for laser-cooled atoms has been proposed in "Stochastic cooling of atoms using lasers," see Phys. Rev. A, vol. 58, p. 4757 (1998). Our scheme involves a measurement of the coherent redistribution of photons between different laser beams of the optical lattice.
Limitation of entanglement due to spatial qubit separation

We consider spatially separated qubits coupled to a thermal bosonic field that causes pure dephasing. Our focus is on the entanglement of two Bell states which for vanishing separation are known as robust and fragile entangled states. The reduced two-qubit dynamics is solved exactly and explicitly. Our results allow us to gain information about the robustness of two-qubit decoherence-free subspaces with respect to physical parameters such as temperature, qubit-bath coupling strength and spatial separation of the qubits. Moreover, we clarify the relation between single-qubit coherence and two-qubit entanglement and identify parameter regimes in which the terms robust and fragile are no longer appropriate.
Block copolymer based composition and morphology control in nanostructured hybrid materials for energy conversion and storage: solar cells, batteries, and fuel cells

The development of energy conversion and storage devices is at the forefront of research geared towards a sustainable future. However, there are numerous issues that prevent the widespread use of these technologies including cost, performance and durability. These limitations can be directly related to the materials used. In particular, the design and fabrication of nanostructured hybrid materials is expected to provide breakthroughs for the advancement of these technologies. This tutorial review will highlight block copolymers as an emerging and powerful yet affordable tool to structure-direct such nanomaterials with precise control over structural dimensions, composition and spatial arrangement of materials in composites. After providing an introduction to materials design and current limitations, the review will highlight some of the most recent examples of block copolymer structure-directed nanomaterials for photovoltaics, batteries and fuel cells. In each case insights are provided into the various underlying fundamental chemical, thermodynamic and kinetic formation principles enabling general and relatively inexpensive wet-polymer chemistry methodologies for the efficient creation of multiscale functional materials. Examples include nanostructured ceramics, ceramic–carbon composites, ceramic–carbon–metal composites and metals with morphologies ranging from hexagonally arranged cylinders to three-dimensional bi-continuous cubic networks. The review ends with an outlook towards the synthesis of multicomponent and hierarchical multifunctional hybrid materials with different nano-architectures from self-assembly of higher order blocked macromolecules which may ultimately pave the way for the further development of energy conversion and storage devices.
Syntactic Closed-cell Foams Based on Silicon Carbide

Closed cell foams were fabricated by incorporating two different grades of hollow aluminosilicate spheres (cenospheres) into a silicon carbide matrix. The silicon carbide matrix was formed by the pyrolysis of a preceramic polymer, and multiple polymer infiltration and pyrolysis (PIP) cycles were employed to minimize the open voids in the material. The physical, mechanical and thermal properties of the fabricated foams were characterized as functions of the number of reinfiltration cycles. The open- and closed-void volume fractions were determined by measurements of bulk and skeletal densities. Mechanical properties, including strength and modulus, were evaluated using four-point bend and compression tests. Finally, thermophysical (thermal conductivity) values of the material were determined using laser-flash technique. This processing technique results in closed-cell syntactic foams with low density (≤ 1.8g/cm3), reasonable mechanical strength (~ 30 MPa) and very low thermal conductivity (≤ 1 W/m-K). In this manner, this process can be used for the low-cost and net-shape fabrication of closed-cell silicon carbide syntactic foams for high temperature applications.
On the economic incentives for taking bribes

This paper presents an empirical analysis of the factors affecting bribe taking by public officials. Factors influencing the acceptance of bribes include: the probability of being convicted, severity of punishment, government salary relative to private sector income, the demonstration effect, and the unemployment rate. Our results indicate that higher probability of being convicted discourages the acceptance of bribes as does more severe punishment. Low relative earnings, high unemployment, and the demonstration effect of aggregate advertising all lead to increased bribe taking.
From Conception to Realization: An Historial Account of Graphene and Some Perspectives for Its Future

There has been an intense surge in interest in graphene during recent years. However, graphene-like materials derived from graphite oxide were reported in 1962, and related chemical modifications of graphite were described as early as 1840. In this detailed account of the fascinating development of the synthesis and characterization of graphene, we hope to demonstrate that the rich history of graphene chemistry laid the foundation for the exciting research that continues to this day. Important challenges remain, however; many with great technological relevance.
MAGELLANIC CLOUD GRAVITATIONAL MICROLENSING RESULTS : WHAT DO THEY MEAN?

Abstract Recent results from gravitational microlensing surveys of the Large Magellanic Cloud are reviewed. The combined microlensing optical depth of the MACHO and EROS-1 surveys is τLMC=2.1−0.8+1.3×10−7 which is substantially larger than the background of τback≤0.5×10−7 from lensing by known stellar populations although it is below the expected microlensing optical depth of τ=4.7×10−7 for a halo composed entirely of Machos. The simplest interpretation of these results is that nearly half of the dark halo is composed of Machos with a typical mass of order 0.5 M ⊙ . This could be explained if these Machos are old white dwarfs, but it is not obvious that the generation of stars that preceded these white dwarfs could have gone undetected. It is also possible that Machos are not made of baryons, but there is no compelling model for the formation of non-baryonic Machos. Therefore, a number of authors have been motivated to develop alternative models which attempt to explain the LMC microlensing results with non-halo populations. Many of these alternative models postulate previously unknown dark stellar populations which contribute significantly to the total mass of the Galaxy and are therefore simply variations of the dark matter solution. However, models which postulate an unknown dwarf galaxy along the line of site to the LMC or a distortion of the LMC which significantly enhances the LMC self-lensing optical depth can potentially explain the LMC lensing results with only a small amount of mass, so these can be regarded as true non-dark matter solutions to the Macho puzzle. All such models that have been proposed so far have serious problems, so there is, as yet, no compelling alternative to the dark matter interpretation. However, the problem can be solved observationally with a second generation gravitational microlensing survey that is significantly more sensitive than current microlensing surveys.
On the complexity of decentralized decision making and detection problems

We study the computational complexity of the discrete versions of some simple but basic decentralized decision problems. These problems are variations of the classical "team decision problem" and include the problem of decentralized detection whereby a central processor is to select one of two hypotheses, based on l-bit messages from two noncommunicating sensors. Our results point to the inherent difficulty of decentralized decision making and suggest that optimality may be an elusive goal.
Endogenous growth through investment-specific technological change

Abstract This paper examines a model in which growth takes place through investment-specific technological change, which in turn is determined endogenously through research spending. In particular, the role of the degree of substitutability between research spending and new capital construction is explored. It is shown that the effect of a change in the capital tax rate on the growth rate can depend on the degree of substitutability between research spending and new capital construction. Research subsidies tend to have a larger impact on the growth rate than would an investment tax credit of the same magnitude. Increases in the capital tax rate can increase the growth rate of the economy, even in the absence of externalities. In contrast to the existing literature, the welfare cost of capital taxation in this model can be negligible. There may be multiple tax rates on capital that achieve the same growth rate. It is demonstrated that in the presence of certain types of positive externalities, the optimal growth rate can be attained through the use of capital taxes—rather than subsidies.
Diels–Alder approaches to ring-functionalized cyclic β-amino acids

Catalytic asymmetric Diels–Alder reactions with aminodiene 1 and desymmetrized fumarate 8 were used for efficient access to dihydroxylated cis- and trans-aminocyclohexane β-amino acids.