cssi/SciSciGPT-SciSciNet huggingface dataset:
Vacuum-ultraviolet instrumentation for solar irradiance and thermospheric airglow

A NASA sounding rocket experiment was developed to study the solar extreme ultraviolet (EUV) spectral irradiance and its effect on the upper atmosphere. Both the solar flux and the terrestrial molecular nitrogen via the Lyman-Birge-Hopfield bands in the far ultraviolet (FUV) were measured remotely from a sounding rocket on October 27, 1992. The rocket experiment also includes EUV instruments from Boston University (Supriya Chakrabarti), but only the National Center for Atmospheric Research (NCAR)/University of Colorado (CU) four solar instruments and one airglow instrument are discussed here. The primary solar EUV instrument is a 1/4 meter Rowland circle EUV spectrograph which has flown on three rockets since 1988 measuring the solar spectral irradiance from 30 to 110 nm with 0.2 nm resolution. Another solar irradiance instrument is an array of six silicon XUV photodiodes, each having different metallic filters coated directly on the photodiodes. This photodiode system provides a spectral coverage from 0.1 to 80 nm with about 15 nm resolution. The other solar irradiance instrument is a silicon avalanche photodiode coupled with pulse height analyzer electronics. This avalanche photodiode package measures the XUV photon energy providing a solar spectrum from 50 to 12,400 eV (25 to 0.1 nm) with an energy resolution of about 50 eV. The fourth solar instrument is an XUV imager that images the sun at 17.5 nm with a spatial resolution of 20 arc-seconds. The airglow spectrograph measures the terrestrial FUV airglow emissions along the horizon from 125 to 160 nm with 0.2 nm spectral resolution. The photon-counting CODACON detectors are used for three of these instruments and consist of coded arrays of anodes behind microchannel plates. The one-dimensional and two-dimensional CODACON detectors were developed at CU by Dr. George Lawrence. The pre-flight and post-flight photometric calibrations were performed at our calibration laboratory and at the Synchrotron Ultraviolet Radiation Facility (SURF) at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland.
Non-isothermal wetting during impact of millimeter-size water drop on a flat substrate: Numerical investigation and comparison with high-speed visualization experiments

Abstract The objective of this work is to develop and validate a numerical model to study wetting during the impact of millimeter-size drops on a flat, smooth, solid substrate under isothermal or non-isothermal conditions. A finite-element modeling is used to simulate the transient fluid dynamics and heat transfer, considering Laplace forces on the liquid–gas boundary. The Lagrangian scheme allows a very precise tracking of the free surface deformation. In this work, the numerical model is extended to account for a temperature-dependent viscosity and for dynamic wetting at the contact line. Numerical results are presented to study the influence of the kinetic wetting parameter on the wetting incipience and behavior. Our results show the influence of wetting on the spreading and the transient drop shape. Also, numerical results are compared with high-speed visualization, for cases of isothermal and non-isothermal impact. Matching between simulations and high-speed visualization allows the determination of the value of the kinetic wetting parameter. Our main finding is that warm drops spread more than cold drops because of a reduction of viscous forces, and not because of an increase of wetting.
A concise route to the tetracyclic core of phorbol

Abstract The tetracyclic ketone 17, which possesses a framework closely related to phorbol, has been prepared in enantiomerically pure condition. Condensation of the dichlorocerate derived from 3 with 2-chlorocyclohexanone leads to chlorohydrins 4 and 5 in a 1:1 ratio. Treatment of 5 with excess vinylmagnesium bromide delivers 7, thereby setting the stage for anionic oxy-Cope rearrangement to 9. Epoxidation of 9 and base-promoted cyclization of the α-isomer (15) under kinetically controlled conditions eventuates in the formation of 17. A companion set of reactions was performed on 4 with the result that hemiketal 11 is formed following transannular ring closure. Lastly, one of the first intramolecularly competitive anionic oxy-Cope rearrangements is described.
Additive closed symmetric monoidal structures on R-modules

Abstract In this paper, we classify additive closed symmetric monoidal structures on the category of left R -modules by using Watts’ theorem. An additive closed symmetric monoidal structure is equivalent to an R -module Λ A , B equipped with two commuting right R -module structures represented by the symbols A and B , an R -module K to serve as the unit, and certain isomorphisms. We use this result to look at simple cases. We find rings R for which there are no additive closed symmetric monoidal structures on R -modules, for which there is exactly one (up to isomorphism), for which there are exactly seven, and for which there are a proper class of isomorphism classes of such structures. We also prove some general structural results; for example, we prove that the unit K must always be a finitely generated R -module.
The new wave of computing in colleges and universities: a social analysis

North American colleges and universities have changed noticeably in the last five years. Undergraduates care more about jobs, grades and getting through quietly. Few faculty champion these changes. Many faculty and students have also gained access to a new array of computing equipment -- from microcomputers to supercomputers. Many campuses have some kind of rudimentary computer networking and some support electronic mail for faculty and staff. New technologies can be exciting. The press and institutional announcements often romanticize this new wave of academic computerization. Every campus has a cadre of students and faculty who value some of these computerization efforts and who hope for more.
Stochastic Dominance Approach to Evaluate Optimism Bias in Truck Toll Forecasts

Optimism bias is a consistent feature associated with truck toll forecasts, a la Standard & Poor's and the NCHRP synthesis reports. Given the persistent problem, two major sources of this bias are explored. In particular, the ignorance of operating cost as a demand-side factor and lack of attention to user heterogeneity are found to contribute to this bias. To address it, stochastic dominance analysis is used to assess the risk associated with toll revenue forecasts. For a hypothetical corridor, it is shown that ignorance of operating cost savings can lead to upward bias in the threshold value of time distribution. Furthermore, dominance analysis demonstrates that there is greater risk associated with the revenue forecast when demand heterogeneity is factored in. The approach presented is general and can be applied to all toll forecasts and is not restricted to trucks.
Using a Low-Cost SoC Computer and a Commercial RTOS in an Embedded Systems Design Course

This paper describes the author's experiences using a low-cost system-on-a-chip (SoC) embedded computer system and a commercial real-time operating system (RTOS) in the laboratory component of an undergraduate embedded system design class. The target hardware is a small low-cost X86 SoC computer system that has a wide range of I/O features. For software development, a popular commercial hard RTOS is used that has been designed for use in embedded devices. This course covers both hardware and software topics in embedded systems, and the course culminates in a final team-based design project. A full set of course materials including a textbook with laboratory tutorials, instructor slides, and code examples has been developed and is available online in electronic form.
The effect of decision makers’ time perspective on intention–behavior consistency

This research demonstrates that decision makers’ time perspective—a cognitive, temporal bias that leads people to overemphasize the past, present, or future in their decision making—systematically influences self-reported behavioral intentions and thus intention–behavior consistency for distant-future behaviors. Whereas present-hedonistic individuals overstate their intentions, present-fatalistic individuals understate theirs, so both types exhibit low intention–behavior consistency. Future time-oriented individuals instead exhibit high intention–behavior consistency because they are less likely to overstate their intentions. The findings are contributed to decision makers’ time perspective influencing the construal of distant-future behavior when reporting behavioral intentions. Accounting for decision makers’ time perspectives helps improve predictive accuracy and may change insights obtained from causal models that use self-reported intentions as a proxy for actual, distant-future behavior.
Quenched invariance principle for simple random walk on percolation clusters

We consider the simple random walk on the (unique) infinite cluster of super-critical bond percolation in ℤ d with d≥2. We prove that, for almost every percolation configuration, the path distribution of the walk converges weakly to that of non-degenerate, isotropic Brownian motion. Our analysis is based on the consideration of a harmonic deformation of the infinite cluster on which the random walk becomes a square-integrable martingale. The size of the deformation, expressed by the so called corrector, is estimated by means of ergodicity arguments.
Photochemistry of benzoin acetate in cyclodextrin media

Abstract Photolyses of benzoin acetate 1 in organic solvents produce a non-selective mixture of type I products ( 3/2-5 ) and photocyclization product 2 , while in aqueous cyclodextrin (CD) solutions and in solid CD complexes, a remarkable selectivity for photocyclization product 2 is observed. A Cage effect has been invoked to rationalize the unusual alteration of photobehaviour of 1 by CD.
Clustering time-series energy data from smart meters

Investigations have been performed into using clustering methods in data mining time-series data from smart meters. The problem is to identify patterns and trends in energy usage profiles of commercial and industrial customers over 24-h periods and group similar profiles. We tested our method on energy usage data provided by several U.S. power utilities. The results show accurate grouping of accounts similar in their energy usage patterns, and potential for the method to be utilized in energy efficiency programs.
The room temperature metastable/stable phase relationships in the pseudo-binary Gd5Si4–Gd5Ge4 system ☆

Abstract The phase relationships, crystallography and magnetic phase diagram of the pseudo-binary Gd5Si4–Gd5Ge4 system in the as-cast state is described. Three extended solid solution regions were confirmed: the Si-rich alloys which have the orthorhombic Gd5Si4-type structure, the intermediate region alloys with the monoclinic Gd5Si2Ge2-type structure and the Ge-rich alloys which have the orthorhombic Sm5Ge4-type structure. The sample preparation techniques and the methods used for determining the phase purity of the alloys are also discussed.
Multivalued attractors and their approximation: applications to the Navier---Stokes equations

This article is devoted to the study of multivalued semigroups and their asymptotic behavior, with particular attention to iterations of set-valued mappings. After developing a general abstract framework, we present an application to a time discretization of the two-dimensional Navier---Stokes equations. More precisely, we prove that the fully implicit Euler scheme generates a family of discrete multivalued dynamical systems, whose global attractors converge to the global attractor of the continuous system as the time-step parameter approaches zero.
Parallel solution-phase synthesis of mechanism-based cysteine protease inhibitors.

A seven-step parallel solution-phase synthesis has been developed for access to ketone-containing mechanism-based cysteine protease inhibitors. The use of liquid−liquid extractions, volatile or solid-supported reagents, and resin-bound scavengers eliminates the need for intermediate column chromatographic purification during this synthesis sequence.
Insurance as an Instrument of War in the 18th Century

In his famous essay on London's Royal Exchange, Joseph Addison marveled at the international concord produced when commercial men freely pursued their economic interests: “Factors in the trading world are what ambassadors are in the politic world; they negotiate affairs, conclude treaties, and maintain a good correspondence between those wealthy societies of men that are divided from one another by seas and oceans, or live on the different extremities of a continent.”1 But men with more than Addison's armchair experience of mercantile affairs had a less irenic view of international trade. Nicholas Magens, a merchant and insurer with a distinguished career and great authority among his fellows, argued that “the great object of a maritime nation should be, to take advantage of any rupture with another trading state, to destroy and distress their [sic] shipping, and commerce, and to cut off all resources for naval armaments.”2 Nowhere in 18th-century economic policy was the clash between the promotion of international trade and the beggaring of commercial rivals so keenly felt as in the British debate over the wisdom of insuring enemy ships in wartime. The controversy and the resulting parliamentary acts of 1746 and 1748 reveal a complicated and vacillating strategy by which the British sought to exploit their dominance of the international marine insurance industry for wartime advantage.
Thick Film Analysis of Radiative Transfer Between Parallel Metallic Surfaces

The radiative transfer between two infinite parallel metallic surfaces separated by a nonconducting ideal dielectric is calculated on the basis of electromagnetic wave theory. The solution is restricted to the case of large spacing (thick film) wherein the effects of interference and radiation tunneling can be neglected. The optical properties of the metals are predicted via the anomalous skin effect theory, the Drude single electron theory and the Hagen-Rubens relation. A comparison of the predicted radiative fluxes indicates the large disparities which result from the three different specifications of the optical properties of metals. For practical applications at cryogenic temperatures, approximations are obtained for the thick film solution using the anomalous skin effect theory of the optical properties.
Clique Partitions, Graph Compression and Speeding-Up Algorithms

We first consider the problem of partitioning the edges of a graph G into bipartite cliques such the total order of the cliques is minimized, where the order of a clique is the number of vertices in it. It is shown that the problem is NP-complete. We then prove the existence of a partition of small total order in a sufficiently dense graph and devise an efficient algorithm to compute such a partition and the running time. Next, we define the notion of a compression of a graph G and use the result on graph partitioning to efficiently compute an optimal compression for graphs of a given size. An interesting application of the graph compression result arises from the fact that several graph algorithms can be adapted to work with the compressed representation of the input graph, thereby improving the bound on their running times, particularly on dense graphs. This makes use of the trade-off result we obtain from our partitioning algorithm. The algorithms analyzed include those for matchings, vertex connectivity, edge connectivity, and shortest paths. In each case, we improve upon the running times of the best-known algorithms for these problems.
Effect of glutamine on preimplantation mouse embryo development in vitro

Abstract Objectives The purpose of this research was to study the independent effect of the amino acid glutamine on preimplantation mouse embryo development in vitro. Study design Two-cell stage mouse embryos were cultured in human tubal fluid medium in the presence and absence of 1 mmol/L of glutamine. Outcomes for morphology and cleavage rates were compared with Fisher's and Mann-Whitney's tests, respectively. Results Glutamine increased the proportion of embryos that developed to the blastocyst stage (86.4%) compared with those cultured without glutamine (59.1%) ( P =.052). The percentages of embryos developing to the morula or hatching blastocyst stages were comparable in the 2 groups. Blastocyst total cell numbers were significantly higher in the glutamine group (34±1.7 vs 18.5±3.5, respectively; values are mean±SEM, P =.044). Conclusion The amino acid glutamine independently improves preimplantation mouse embryo development in vitro. Further studies are needed to examine the applicability of these results to humans.
Quantal Response Equilibria for Extensive Form Games

This article investigates the use of standard econometric models for quantal choice to study equilibria of extensive form games. Players make choices based on a quantal-choice model and assume other players do so as well. We define an agent quantal response equilibrium (AQRE), which applies QRE to the agent normal form of an extensive form game and imposes a statistical version of sequential rationality. We also define a parametric specification, called logit-AQRE, in which quantal-choice probabilities are given by logit response functions. AQRE makes predictions that contradict the invariance principle in systematic ways. We show that these predictions match up with some experimental findings by Schotter et al. (1994) about the play of games that differ only with respect to inessential transformations of the extensive form. The logit-AQRE also implies a unique selection from the set of sequential equilibria in generic extensive form games. We examine data from signaling game experiments by Banks et al. (1994) and Brandts and Holt (1993). We find that the logit-AQRE selection applied to these games succeeds in predicting patterns of behavior observed in these experiments, even when our prediction conflicts with more standard equilibrium refinements, such as the intuitive criterion. We also reexamine data from the McKelvey and Palfrey (1992) centipede experiment and find that the AQRE model can account for behavior that had previously been explained in terms of altruistic behavior.
Structural Estimation of Rank-Order Tournament Games with Private Information

In this article we propose and solve a game-theoretic model of a rank-order tournament with private information. Using the contract settlement data from a poultry company, we estimate a fully structural model of a symmetric Nash equilibrium of this game. We show that growers’ equilibrium effort depends on four factors: the spread in piece rates between the performance brackets, the number of players in each tournament, the number of performance brackets used, and the density of growers’ private shocks. We use estimates to simulate how changes in the tournament characteristics affecting equilibrium effort impact the growers’ and the integrator’s welfare. In most sporting events, prizes are awarded not on basis of absolute performance but based on relative performance, or tournaments. Be­ sides sporting events, tournaments are also frequently used in labor contracts. The name “tournament” typically suggests a rank-order (ordinal) scheme such as is considered by Lazear and Rosen (1981), whereas a broader definition applies to any compensation scheme based on relative performance (e.g., Nalebuff and Stiglitz 1983; Tsoulouhas and Vukina 1999). Despite the sizeable theoretical litera­ ture on tournaments, empirical work related to these models remains rather limited. Most of the theoretical literature on tournaments (see McLaughlin 1988 for a survey) has been con­ cerned primarily with the comparison of tour­ naments against various independent reward structures under various assumptions about risk preferences, the number of participants and prizes, specifications of production shocks, and the asymmetry of information. Previous empirical work has largely focused on testing the predictions of the theoretical models. This includes articles on executive compensation (e.g., Main, O’Reilly and Wade 1993; Ericksson 1999; Gibbons and Murphy 1990), profes­ sional sports (e.g., Ehrenberg and Bognanno
Bi-local construction of Sp(2N)/dS higher spin correspondence

We derive a collective field theory of the singlet sector of the Sp(2N) sigma model. Interestingly the Hamiltonian for the bilocal collective field is the same as that of the O(N) model. However, the large-N saddle points of the two models differ by a sign. This leads to a fluctuation Hamiltonian with a negative quadratic term and alternating signs in the nonlinear terms which correctly reproduces the correlation functions of the singlet sector. Assuming the validity of the connection between O(N) collective fields and higher spin fields in AdS, we argue that a natural interpretation of this theory is by a double analytic continuation, leading to the dS/CFT correspondence proposed by Anninos, Hartman and Strominger. The bi-local construction gives a map into the bulk of de Sitter space-time. Its geometric pseudospin-representation provides a framework for quantization and definition of the Hilbert space. We argue that this is consistent with finite N Grassmannian constraints, establishing the bi-local representation as a nonperturbative framework for quantization of Higher Spin Gravity in de Sitter space.
Homologous Mechanisms of Visuospatial Working Memory Maintenance in Macaque and Human: Properties and Sources

Although areas of frontal cortex are thought to be critical for maintaining information in visuospatial working memory, the event-related potential (ERP) index of maintenance is found over posterior cortex in humans. In the present study, we reconcile these seemingly contradictory findings. Here, we show that macaque monkeys and humans exhibit the same posterior ERP signature of working memory maintenance that predicts the precision of the memory-based behavioral responses. In addition, we show that the specific pattern of rhythmic oscillations in the alpha band, recently demonstrated to underlie the human visual working memory ERP component, is also present in monkeys. Next, we concurrently recorded intracranial local field potentials from two prefrontal and another frontal cortical area to determine their contribution to the surface potential indexing maintenance. The local fields in the two prefrontal areas, but not the cortex immediately posterior, exhibited amplitude modulations, timing, and relationships to behavior indicating that they contribute to the generation of the surface ERP component measured from the distal posterior electrodes. Rhythmic neural activity in the theta and gamma bands during maintenance provided converging support for the engagement of the same brain regions. These findings demonstrate that nonhuman primates have homologous electrophysiological signatures of visuospatial working memory to those of humans and that a distributed neural network, including frontal areas, underlies the posterior ERP index of visuospatial working memory maintenance.
Constant-depth Frege systems with counting axioms polynomially simulate Nullstellensatz refutations

We show that constant-depth Frege systems with counting axioms modulo m polynomially simulate Nullstellensatz refutations modulo m. Central to this is a new definition of reducibility from propositional formulas to systems of polynomials. Using our definition of reducibility, most previously studied propositional formulas reduce to their polynomial translations. When combined with a previous result of the authors, this establishes the first size separation between Nullstellensatz and polynomial calculus refutations. We also obtain new upper bounds on refutation sizes for certain CNFs in constant-depth Frege with counting axioms systems.
Evolution in the Color-Magnitude Relation of Early-Type Galaxies in Clusters of Galaxies at z 1

We present a study of the color evolution of elliptical and S0 galaxies in six clusters of galaxies inside the redshift range 0.78 3. We find possible evolution in the scatter of the colors, with some high-redshift clusters showing scatter as small as the Coma Cluster but others showing much larger scatter. Those clusters with a small scatter imply either a formation redshift of at least z ~ 3 or a smaller spread in the range of formation redshifts at lower redshifts, assuming a Gaussian distribution of star formation around the mean epoch.
Computer applications in archaeology

In preparing this paper I have tried to give an accurate general picture of the kinds of things which have been done with computers by archaeologists and to give some of my own views about things which most need doing, but I have not tried to list every archaeological application of a computer ever made. The emphasis is mostly on work done in North America, and I believe that the coverage of significant work in this region is quite complete. I also include a good deal of what has been done in western and central Europe, but much less on eastern Europe and the Soviet Union. Gardin has recently cited several important Russian publications which so far as I know are not available in English.
Normative concepts analysis: unpacking the language of legitimation

How should we study the language of political legitimation? Incipient scholarship increasingly seeks to bridge the conceptual schism between the sociological is and the philosophical ought in the study of legitimacy, looking at public legitimating discourses to uncover the actual social attitudes toward prescriptive principles. And while this research agenda has recently gained traction, its methodology remains opaque. This paper suggests that normative concepts, central to the argumentations that hold common basic beliefs and discourse together, can allow us to tap into the language of legitimation. Normative concepts can be traced via mixed methods research, incorporating the quantitative method of corpus linguistics and the qualitative method of discourse-tracing – two techniques that mutually enrich and complement each other. By illuminating changes in the sort, scale, and scope of normative concepts, this mode of inquiry can explicate the language of legitimation and advance our understanding of soci...
The structural characteristics of chicken fibrinogen.

Abstract The structure and subunit composition of chicken fibrinogen have been investigated and compared with that of human origin. Dodecyl sulfate gel electrophoresis of unreduced specimens revealed a single fibrinogen band, representing core species with a molecular weight of approximately 320 000. Dodecyl sulfate gel electrophoresis of specimens reduced with dithiothreitol or of chromatographically separated S-sulfo chains indicated that chicken Aα chains, like those of mammalian origin, possessed a reptilase and thrombin sensitive site. These chains were considerably smaller than human Aα chains (54 500 vs. 70 900, respectively) but, like mammalian Aα chains, were periodic acid Schiff negative and could undergo factor XIIIa catalyzed α-polymer formation. The sizes of chicken Bβ and γ chains were nearly the same as their mammalian counterparts, (i.e. 60 000 and 49 000, respectively); both types of chains were periodic acid Schiff positive. Chicken Bβ chains possessed a thrombin sensitive site, but attack at this site proceeded relatively slowly; the chicken β chains, like mammalian β chains, did not undergo factor XIIIa catalyzed cross-linking. Like mammalian γ chains, chicken γ chains could undergo factor XIIIa catalyzed γ−γ dimerization and did not possess thrombin or reptilase sensitive sites. The chromatographic elution profile of the S-sulfo γ chains suggested the presence of a type of heterogeneity (termed ‘γ-1/γ-2’) also observed in mammalian γ chains. We conclude that the chicken fibrinogen molecule is composed of three pairs of disulfidebridged chains corresponding in most respects to mammalian fibrinogen chains.
Brazilian nationalism and the dynamics of its political development

As so often happens, nationalism appears in the social-historical picture as an entity in the dual garb of phenomenon and purpose. Referring to one of my earlier studies on the subject 1 and to certain wellknown texts such as The Idea of Nationalism, by Kohn =, or Hertz's study of nationality a, I think I can generalize this idea by saying that nationalism is a process both objective and subjective. This also applies to the particular social unit which we call nation, to the maintenance and furtherance of whose individual integrity nationalism is directed.
Identification of G1-regulated genes in normally cycling human cells.

Background Obtaining synchronous cell populations is essential for cell-cycle studies. Methods such as serum withdrawal or use of drugs which block cells at specific points in the cell cycle alter cellular events upon re-entry into the cell cycle. Regulatory events occurring in early G1 phase of a new cell cycle could have been overlooked. Methodology and Findings We used a robotic mitotic shake-off apparatus to select cells in late mitosis for genome-wide gene expression studies. Two separate microarray experiments were conducted, one which involved isolation of RNA hourly for several hours from synchronous cell populations, and one experiment which examined gene activity every 15 minutes from late telophase of mitosis into G1 phase. To verify synchrony of the cell populations under study, we utilized methods including BrdU uptake, FACS, and microarray analyses of histone gene activity. We also examined stress response gene activity. Our analysis enabled identification of 200 early G1-regulated genes, many of which currently have unknown functions. We also confirmed the expression of a set of genes candidates (fos, atf3 and tceb) by qPCR to further validate the newly identified genes. Conclusion and Significance Genome-scale expression analyses of the first two hours of G1 in naturally cycling cells enabled the discovery of a unique set of G1-regulated genes, many of which currently have unknown functions, in cells progressing normally through the cell division cycle. This group of genes may contain future targets for drug development and treatment of human disease.
Mig6 haploinsufficiency protects mice against streptozotocin-induced diabetes

Aims/hypothesis EGF and gastrin co-administration reverses type 1 diabetes in rodent models. However, the failure of this to translate into a clinical treatment suggests that EGF-mediated tissue repair is a complicated process and warrants further investigation. Thus, we aimed to determine whether EGF receptor (EGFR) feedback inhibition by mitogen-inducible gene 6 protein (MIG6) limits the effectiveness of EGF therapy and promotes type 1 diabetes development.
Scanning probe studies of water nucleation on aluminum oxide and gold surfaces

Abstract The nucleation of nanoscale water at surfaces in humid environments is sensitive to several factors, including the details of the surface morphology, ability of the surface to hydrate and the presence of contaminants. Tapping mode atomic force microscopy was used to investigate the nucleation process as a function of relative humidity (RH) on passive aluminum and gold thin films. Films exposed to the ambient environment prior to RH exposure showed discrete structures with lateral sizes ranging from 10 to 100 nm only at RH > 70%. These structures formed preferentially at grain boundaries, triple points and regions with significant topography such as protruding grains. The morphology of the passive aluminum surface is permanently altered at the sites where discrete structures were observed; nodules with heights ranging from 0.5 to 2 nm persist even after reducing the RH to
Trade liberalization and rising wage inequality in Latin America: Reconciliation with HOS theory

Abstract The paper puts forward the hypothesis that the transitory effects of trade liberalization on wage inequality can differ from the long-run outcome. In cases where the HOS theory predicts a decline in wage inequality in the long run, a temporary rise can, nevertheless, occur due to (i) the asymmetries in the speed of contraction in the import sector and expansion in other sectors, and (ii) the capital-skill complementarity in production. The asymmetric contraction and expansion causes a transitory capital accumulation that boosts the relative and the real wage of skilled labor due to capital-skill complementarity. Although the long-run HOS fundamentals are, therefore, dominated in the short run by the transient effects arising due to capital-skill complementarity, the observed rise in wage inequality is nonetheless consistent with the HOS theory appropriately extended to a dynamic setting.
The effect of beam energy and number of fields on photon-based IMRT for deep-seated targets.

To examine the influence of energy and number of beams on nontarget dose when using intensity-modulated radiation therapy (IMRT) to treat deep-seated targets. Ten patients with prostate cancer (36–226 cc) treated locally to 75.6 Gy were studied. IMRT plans were created for 6-, 10-, and 18-MV photons using 4, 6, 9, and 11 coplanar nonopposed fields. Plans, normalized to cover 95% of the target volume, were analyzed using: (a) conformity index (CI) at 105%, 100%, 95%, 90%, 80%, 70%, 50% of prescribed dose; (b) prescription isodose line (PI); (c) minimum dose to target (Tarmin); (d) maximum dose to tissue (Tismax); (e) dose to rectum/bladder/penis bulb; (f) integral nontarget dose (ID). Because CI evaluates dose independent of location, tissue also was divided into “near region” (NR: 1-cm-thick shell surrounding target) and “far region” (FR: tissue minus NR) volumes that were evaluated at the same levels as CI. The target and sensitive structure metrics were the same for all plans. However, although there was little difference in NR volume exposed to dose, regardless of energy or number of fields, there was a significant increase in FR volume exposed to dose, at all levels, for low energy/few field plans compared to high energy/many fields (e.g., > 50 cc ≥ 65 Gy). This effect disappeared with ≥ 9 fields regardless of energy. With IMRT, the use of 6 MV photons with less than 9 fields may result in an increase in dose in regions distant from the target volume (e.g., near the skin surface), even though the CI and sensitive structure metrics may indicate good conformance of high dose to the target volume itself. The clinical significance of this increased dose distant from the target, in terms of complications, remains to be determined.
Design and Ownership of Two-Sided Networks: Implications for Internet Platforms

Many Internet intermediaries operate two-sided networks, that is, they provide platforms to bring together two types of participants, or "sides," such as buyers and sellers. This paper develops a model that characterizes the intermediary's pricing in two-sided networks, the value created by these networks, and the allocation of that value across the two sides. It extends the two-sided networks literature by endogenizing the level of network effects as the result of relevant investments by the intermediary, which determine the design of the network. It shows that under certain assumptions about the available technologies, the design of the two-sided network is highly asymmetric independent of its ownership structure. The paper provides insight into design strategies for Internet platforms, and it discusses their welfare implications.
HIV, wages, and the skill premium.

Abstract The HIV epidemic has dramatically decreased labor supply among prime-age adults in Sub-Saharan Africa. Using within-country variation in regional HIV prevalence and a synthetic panel, I find that HIV significantly increases the capital–labor ratio in urban manufacturing firms. The impact of HIV on average wages is positive but imprecisely estimated. In contrast, HIV has a large positive impact on the skill premium. The impact of HIV on the wages of low skilled workers is insignificantly different from 0, and is strongly dampened by competition from rural migrants. The HIV epidemic disproportionately increases the incomes of high-skilled survivors, thus increasing inequality.
A Novel Reaction Path to BaTiO3 by the Oxidation of a Solid Metallic Precursor

Multilayer capacitors with thin, dielectric BaTiO3 layers can possess a relatively high capacitance per unit volume. A solid metallic precursor method has recently been developed for preparing thin BaTiO3/noble metal laminates. In the present paper, the phase and microstructural evolution of Ba-Ti metallic precursors were examined after oxidation at 300° to 900°C in pure oxygen at 1 atm pressure. Barium peroxide, BaO2, formed rapidly during oxidation at 300°C, with titanium largely remaining as unoxidized particles in the peroxide matrix. Between 375° and 500°C, the solidstate reaction of barium peroxide with metallic titanium yielded barium orthotitanate, Ba2TiO4. Further exposure to temperatures between 500° and 900°C resulted in the oxidation of residual metallic titanium. The oxidized titanium then reacted with the orthotitanate matrix to form barium metatitanate, BaTiO3. The rate of formation of BaTiO3 was found to be strongly dependent on the degree of milling of the Ba-Ti precursors and on the heating rate between 300° and 500°C.
The FDA's graphic tobacco warnings and the first amendment.

As the Supreme Court has broadened corporate freedom to advertise, it has narrowed governmental power to preserve the public's health. The fate of the FDA-mandated graphic cigarette warnings is illustrative.
A simple, combinatorial algorithm for solving SDD systems in nearly-linear time

In this paper, we present a simple combinatorial algorithm that solves symmetric diagonally dominant (SDD) linear systems in nearly-linear time. It uses little of the machinery that previously appeared to be necessary for a such an algorithm. It does not require recursive preconditioning, spectral sparsification, or even the Chebyshev Method or Conjugate Gradient. After constructing a "nice" spanning tree of a graph associated with the linear system, the entire algorithm consists of the repeated application of a simple update rule, which it implements using a lightweight data structure. The algorithm is numerically stable and can be implemented without the increased bit-precision required by previous solvers. As such, the algorithm has the fastest known running time under the standard unit-cost RAM model. We hope the simplicity of the algorithm and the insights yielded by its analysis will be useful in both theory and practice.
Accelerated Curing of Compacted Calcium Silicate Mortars on Exposure to CO2

The parameters affecting strength development in compacted cylinders of 3CaO- SiO2 and β-2CaO- SiO2 mortars exposed to CO2 were investigated. Strength increased with time up to 81 min, the duration of the longest detailed study. The β-2CaO- SiO2 develops strength more slowly initially, but both silicates achieved compressive strengths of 7,000 to 10,000 psi. The rate of increase in strength depends on both the amount of water used in molding the compact and the amount of water present in the CO2. Increasing CO2 pressures from 1 to 2 atm increased the rate of reaction, but a further increase to 4 atm had little additional effect. Carbonation occurs mainly in the outer portions of the cylindrical compacts. The initial reaction on exposure to CO2 appears to be accelerated hydration of the silicates to a CaO-SiO2-H2O-like gel and calcite. The gel has a stoichiometry similar to that found in conventional hydration. Further reaction results in progressive carbonation of the gel, which decreases its lime content. The reaction products appear to be intimately dispersed in the microstructure.
Non-perturbative Heat Kernel Asymptotics on Homogeneous Abelian Bundles

We study the heat kernel for a Laplace type partial differential operator acting on smooth sections of a complex vector bundle with the structure group G × U(1) over a Riemannian manifold M without boundary. The total connection on the vector bundle naturally splits into a G-connection and a U(1)-connection, which is assumed to have a parallel curvature F. We find a new local short time asymptotic expansion of the off-diagonal heat kernel U(t|x, x′) close to the diagonal of M × M assuming the curvature F to be of order t−1. The coefficients of this expansion are polynomial functions in the Riemann curvature tensor (and the curvature of the G-connection) and its derivatives with universal coefficients depending in a non-polynomial but analytic way on the curvature F, more precisely, on tF. These functions generate all terms quadratic and linear in the Riemann curvature and of arbitrary order in F in the usual heat kernel coefficients. In that sense, we effectively sum up the usual short time heat kernel asymptotic expansion to all orders of the curvature F. We compute the first three coefficients (both diagonal and off-diagonal) of this new asymptotic expansion.
String bit models for superstring

We extend the model of string as a polymer of string bits to the case of superstring. We mainly concentrate on type II-B superstring, with some discussion of the obstacles presented by not II-B superstring, together with possible strategies for surmounting them. As with previous work on bosonic string we work within the light-cone gauge. The bit model possesses a good deal less symmetry than the continuous string theory. For one thing, the bit model is formulated as a Galilei-invariant theory in [({ital D}{minus}2)+1]-dimensional space-time. This means that Poincare invariance is reduced to the Galilei subgroup in {ital D}{minus}2 space dimensions. Naturally the supersymmetry present in the bit model is likewise dramatically reduced. Continuous string can arise in the bit models with the formation of infinitely long polymers of string bits. Under the right circumstances (at the critical dimension) these polymers can behave as string moving in {ital D}-dimensional space-time enjoying the full {ital N}=2 Poincare supersymmetric dynamics of type II-B superstring.
Nonlinear Model-Based Control of an Experimental Reverse Osmosis Water Desalination System*

Abstract Abstract This work focuses on the design and implementation of a nonlinear model-based control system on an experimental reverse osmosis (RO) membrane water desalination system in order to deal with large set-point changes and variations in feed water salinity. A dynamic nonlinear lumped-parameter model is derived using first-principles and its parameters are computed from experimental data to minimize the error between model predictions and experimental RO system response. Then, this model is used as the basis for the design of a nonlinear control system using geometric control techniques. The nonlinear control system is implemented on the experimental RO system and its set-point tracking capabilities are successfully evaluated.
The strongly coupled quark―gluon plasma created at RHIC

The relativistic heavy-ion collider (RHIC) was built to re-create and study in the laboratory the extremely hot and dense matter that filled our entire universe during its first few microseconds. Its operation since June 2000 has been extremely successful, and the four large RHIC experiments have produced an impressive body of data which indeed provide compelling evidence for the formation of thermally equilibrated matter at unprecedented temperatures and energy densities—a 'quark–gluon plasma (QGP)'. A surprise has been the discovery that this plasma behaves like an almost perfect fluid, with extremely low viscosity. Theorists had expected a weakly interacting gas of quarks and gluons, but instead we seem to have created a strongly coupled plasma liquid. The experimental evidence strongly relies on a feature called 'elliptic flow' in off-central collisions, with additional support from other observations. This paper explains how we probe the strongly coupled QGP, describes the ideas and measurements which led to the conclusion that the QGP is an almost perfect liquid, and shows how they tie relativistic heavy-ion physics into other burgeoning fields of modern physics, such as strongly coupled Coulomb plasmas, ultracold systems of trapped atoms and superstring theory.
Phase changes in the niobium-hydrogen system—III. Acoustic studies of hydride phase transitions at H/Nb = 0.78

Abstract Ultrasonic techniques were used to measure the moduli and attenuation of single crystals of NbH0.78 composition over the temperature range 77–525 K. Sufficient acoustic modes were measured to allow determination of all of the cubic moduli for the α′ (b.c.c.) phase and the orthorhombic moduli for the β and e phases. Significant softening of the moduli and increases of the attenuation were observed near the α′-β transition. Discussion of these results is based on a Zener relaxation mechanism and on a Landau model for a second-order phase transition. The moduli and attenuation near the β-e transition did not exhibit any precursor behavior. Relaxations were seen above the β-e transition and these are interpreted on the basis of H density fluctuations in the β phase.
NEUROPROTECTION AGAINST ETHANOL MEDIATED OXIDATIVE STRESS AND APOPTOSIS VIA NRF2/ARE.

This study characterizes a neuroprotective pathway responsible for coordinated enhancement of astrocyte glutathione (GSH)-homeostatic machinery. Injuries in fetal rat cortical neurons associated with Fetal Alcohol Syndrome are correlated to ethanol (E) exposure leading to increased oxidative stress, GSH depletion, and ultimately neuroapoptosis. Our lab has previously published that astrocytes protect neurons from E mediated apoptosis, via maintenance of GSH homeostasis. We hypothesize that neuroprotection is regulated by the activation of the anti-oxidant response elements (ARE) contained in the 5’ regions of cytoprotective genes, via the master transcription factor Nrf2. To identify the role of E in astrocyte anti-oxidant defense induction, we first employed an E time course to investigate Nrf2 protein expression. Primary cultured rat neonatal astrocytes were treated with 4mg/ml E at various time points. There was increased nuclear Nrf2 expression within 15 minutes after E treatment, and lasted up to 4 hours. Immunohistochemical studies corroborate cytoplasmic to nuclear translocation. Enhanced nuclear Nrf2 expression was further augmented by BSO pre-treatment. In addition, the transcription factor Maf, which obligatorily dimerizes with Nrf2 to activate gene transcription, was increased by E or BSO. Known ARE inducers and oxidative stress mimicked the cytoplasmic to nuclear translocation seen in E treatment. To determine whether E increased GSH-homeostatic machinery at the transcriptional level, cells were pre-incubated with Actinomycin D, and subsequently treated with E. Nrf2 expression induced by E was abolished in the presence of AD suggesting that E increases Nrf2 by stimulating gene transcription. Transfection of Nrf2 siRNA completely ablated Nrf2 expression, and furthermore blocks the tert-butyl hydroquinone induced Nrf2, GGT, and Mrp1 expression. Finally, we examined E's effect on Nrf2 ubiquitination. E decreased Nrf2 ubiquitination at 4 and 24 hours while not effecting overall ubiquitin levels in the cell suggesting another possible mechanism for Nrf2 protein level increase and subsequent nuclear translocation to activate ARE. Taken together, this suggests that Nrf2 is required for activation of ARE. The role of E in Nrf2-ARE control of astrocyte neuroprotection needs to be further investigated. These points of regulation may allow for pharmacological augmentation of this crucial neuroprotective mechanism.