cssi/SciSciGPT-SciSciNet huggingface dataset:
THE DEPENDENCE OF GALAXY SHAPE ON LUMINOSITY AND SURFACE BRIGHTNESS PROFILE

For a sample of 96,951 galaxies from the Sloan Digital Sky Survey Data Release 3, we study the distribution of apparent axis ratios as a function of r-band absolute magnitude and surface brightness profile type. We use the parameter fracDeV to quantify the profile type (fracDeV = 1 for a pure de Vaucouleurs profile; fracDeV = 0 for a pure exponential profile). When the apparent axis ratio qam is estimated from the moments of the light distribution, the roundest galaxies are very bright (Mr ~ -23) de Vaucouleurs galaxies and the flattest are modestly bright (Mr ~ -18) exponential galaxies. When the axis ratio q25 is estimated from the axis ratio of the 25 mag arcsec-2 isophote, we find that de Vaucouleurs galaxies, at this low surface brightness, are flatter than exponential galaxies of the same absolute magnitude. For a given surface brightness profile type, very bright galaxies are rounder, on average, than fainter galaxies. We deconvolve the distributions of apparent axis ratios to find the distribution of the intrinsic short-to-long axis ratio ?, making the assumption of constant triaxiality T. For all profile types and luminosities, the distribution of axis ratios is inconsistent with a population of oblate spheroids, but is usually consistent with a population of prolate spheroids. Bright galaxies with a de Vaucouleurs profile (Mr ? -21.84, fracDeV > 0.9) have a distribution of qam that is consistent with triaxiality in the range 0.4 T 0.8, with mean axis ratio 0.66 ? 0.69. The fainter de Vaucouleurs galaxies are best fit with prolate spheroids (T = 1) with mean axis ratio ? ? 0.51.
Corporate spin-offs, bankruptcy, investment, and the value of debt

Abstract In a risk-neutral stochastic environment where bankruptcy is possible, it is well-established that coinsurance incentives may lead creditors to prefer mergers over spin-offs, while shareholders may prefer spin-offs. This paper shows that there are two distinct reasons for this. One is due to the concavity of the debt payoff function in the face value of the debt, while the other arises from imperfect covariation in ultimate firm values. For the latter reason, conventional measures of covariation are not sufficient to evaluate the impact on ex-ante debt value. Also considered are the effects of mergers and spin-offs on investment decisions.
Degeneracy between Abelian and Non-Abelian Strings

In a model that supports both Abelian (Abrikosov–Nielsen–Olesen) and non-Abelian strings we analyze the parameter space to find examples in which these strings not only coexist but are degenerate in tension. We prove that both solutions are locally stable, i.e. there are no negative modes in the string background. The tension degeneracy is achieved at the classical level and is expected to be lifted by quantum corrections. The setup of the model, analogous to that of Witten's superconducting cosmic strings, had been extended to include non-Abelian strings previously [M. Shifman, Phys. Rev. D87, 025025 (2013), arXiv:1212.4823 [hep-th]].
Privacy and Security Aspects of Social Media: Institutional and Technological Environment

Legitimate as well as illegitimate organizations and entities are gaining access to information about social media (SM) users through illegal, extralegal, and quasi-legal means. Worse still, many organizations and individuals using SM have become targets and victims of cybercrimes. SM have also led to an exposure of unethical and illegal conducts within some organizations. One estimate suggested that 36% of social networking users have reported experiencing malware attacks through their profiles. Another study suggested that one in four companies have become cybercrime victims via social networking sites. Likewise, about a quarter of employers surveyed by the Society of Corporate Compliance and Ethics in 2009 had disciplined an employee for improper activities on social networking sites. Organizations that fail to take appropriate technological and behavioral measures related to SM are likely to suffer reputation damages, loss of customers' confidence, and other types of economic losses. The goal of this paper is to develop a framework that provides a simple, explicit mechanism for understanding privacy and security issues associated with SM. To achieve this goal, we draw upon literatures on diverse areas such as institutional theory, marketing and criminology. Specifically, we examine how various institutions from the standpoint of SM superimpose in a unique interaction with SM related technologies’ natures that influence businesses’ and consumers’ privacy and security. We discuss how various features of SM related technologies such as newness (leading to ineffectiveness of existing IT security products), complexity (difficulty to understand SM’s functioning) and attractiveness of SM as a cybercrime target (availability of information with superior targetability and huge size and rapid growth of SM). We also examine how regulative institutions (lack of laws to deal with SM as well as lack of enforcement of existing laws), normative institutions (lack of ethical and professional guidelines) and cognitive institutions (lack of precautionary measures and lack of defensive measures or counterpoison) have contributed to a lack of behavioral and attitudinal measures to ensure privacy and security.
Determining Acceptance Possibility for a Quantum Computation is Hard for the Polynomial Hierarchy

Abstract It is shown that determining whether a quantum computation has a non-zero probability of accepting is at least as hard as the polynomial time hierarchy. This hardness result also applies to determining in general whether a given quantum basis state appears with nonzero amplitude in a superposition, or whether a given quantum bit has positive expectation value at the end of a quantum computation. This result is achieved by showing that the complexity class NQP of Adleman, Demarrais, and Huang, a quantum analog of NP, is equal to the counting class $co-C equals P$.
Probing the spectral and temporal structures of high-order harmonic generation in intense laser pulses

We present an ab initio three-dimensional quantum study of high-order harmonic generation ~HHG! of atomic H in intense pulsed laser fields. Accurate time-dependent wave functions are obtained by means of the time-dependent generalized pseudospectral method recently developed and wavelet transform is used to perform time-frequency analysis of the resulting HHG power spectra. The results reveal striking details of the spectral and temporal fine structures of HHG, providing insights regarding HHG mechanisms in different energy regimes and benchmark data for testing the validity of existing HHG models. PACS number~s!: 42.65.Ky, 32.80.Wr, 42.50.Hz Recently a great deal of attention has been devoted to the study of multiple high-order harmonic generation ~HHG! processes in intense short laser pulses @1‐3#. Besides its fundamental interest for strong-field atomic and molecular physics, the HHG provides a potential tunable coherent light source in the extreme ultraviolet ~XUV! region, a so-called ‘‘tabletop synchrotron’’ @2#. Further, the HHG may lead to a promising way for generating subfemtosecond ~attosecond! pulses of radiation of high frequency @4,5#. For optimal control of the HHG processes, it is essential to have a thorough understanding of the spectral and temporal structures of the high-order harmonics and the detailed underlying mechanisms for HHG. The first experimental observation of the temporal coherence of HHG has recently been reported @6#. In this Rapid Communication, we present an ab initio threedimensional ~3D! precision quantum calculation of the time
Synthesis of E and Z Diastereoisomers of Benzyl Methyl-2-[3-(N-Substituted)indolyl] Cyclopropane-1,1-dicarboxylates and Their Stereoselective Reductive Cleavage

Abstract A synthesis and separation procedure is described for the E and Z diastereoisomers of indolyl-cyclopropane dicarboxylates, IV and V, potential intermediates in the synthesis of the corresponding E and Z cyclopropyl analogs of the amino acid tryptophan and for other ring expansion reactions bearing the indole moiety. Also we have observed a stereoselective cleavage of the benzyl group of the E isomer, without affecting the cyclopropane ring.
Design of structure/control systems with transient response constraints exhibiting relative minima

Structural optimization problems involving dynamic behaviour constraints often exhibit nonconvex design spaces. The direct application of a global optimization algorithm requires a large number of function evaluations which in turn require a large number of dynamic structural analyses. This work presents a strategy aimed at finding the global optimum for problems with transient dynamic behaviour constraints based on approximation concepts. The method consists of generating and solving a sequence of approximate problems using a global optimizer. The approximations are explicit and capture most of the inherent nonconvexity of the exact functions. A simple example. problem is presented to illustrate the procedure set forth.
Adaptive Fuzzy Function Approximation for Multi-agent Reinforcement Learning

Reinforcement learning has difficulties in solving multi-agent problems because of the inefficiency of function approximation. Sparse distributed memories, which is implemented using Radial Basis Functions or Kanerva Coding, can be used to improve the efficiency. But this approach still often give poor performance when applied to large-scale multi-agent systems. In this paper, we attempt to solve a collection of instances in the predator-prey pursuit domain and argue that the poor performance that we observe is caused by frequent prototype collisions. We show that dynamic prototype allocation and adaptation can give better results by reducing these collisions. We then describe our novel approach, fuzzy Kanerva-based function approximation, that uses a fine-grained fuzzy membership grade to describe a state-action pair's adjacency with respect to each prototype. This approach completely eliminates prototype collisions. We further show that prototype density varies widely across the state-action space and that this variation causes prototypes' receptive fields to be unevenly distributed. This distribution limits the ability of fuzzy Kanerva Coding to achieve better results. We demonstrate that another advantage of fuzzy Kanerva Coding is that it allows prototypes to tune their receptive fields for a target application. We conclude that fuzzy Kanerva Coding with prototype tuning and adaptation can significantly improve a reinforcement learner's ability to solve large-scale multi-agent problems.
Grain‐Growth Kinetics for Alumina in the Absence of a Liquid Phase

The kinetics of grain growth in fully dense Al2O3 with and without MgO solute additions were measured for high-purity samples containing no liquid phases. The MgO was found to suppress the grain-boundary migration rate by a factor of 50. Compensating lattice defects are suggested to play a role in grain-growth inhibition. Implications of these results to the sintering of Al2O3 are discussed.
The political economy of mass printing: Legitimacy and technological change in the Ottoman Empire

Abstract New technologies have not always been greeted with full enthusiasm. Although the Ottomans were quick to adopt advancements in military technology, they waited almost three centuries to sanction printing in Ottoman Turkish (in Arabic characters). Printing spread relatively rapidly throughout Europe following the invention of the printing press in 1450 despite resistance by interest groups and temporary restrictions in some countries. We explain differential reaction to technology through a political economy approach centered on the legitimizing relationships between rulers and their agents (e.g., military, religious, or secular authorities). The Ottomans regulated the printing press heavily to prevent the loss it would have caused to the ruler’s net revenue by undermining the legitimacy provided by religious authorities. On the other hand, the legitimizing relationship between European religious and political authorities was undermined over a century prior to the invention of the press. European rulers thus had little reason to stop the spread of printing as public policy, nor could the Church have stopped it had it wanted to. The Ottomans eventually sanctioned printing in Arabic script in the 18th century after alternative sources of legitimacy emerged.
Why Ada is not just another programming language

Ada's importance goes far beyond its initial limited goals. The worldwide interest in the usage of Ada is one of many reasons for its uniqueness.
Diastereoselective synthesis of l-(+)-homolamivudine

l-homolamivudine (2a, (2R,5R)-(+)-cis-5-(1-cytosinylmethyl)-2-hydroxymethyl-1,3-oxathiolane) and its 5-fluoro congener (2b, l-homoFTC) have been prepared from (R)-glycidol by diastereoselective synthesis. Enantioselectivity resulted from stereoselective cyclothioacetalization that preferentially gave the (2R,5R)-cis-2,5-disubstituted-1,3-oxathiolane (5), cistrans = 5.7.
What in the world is weakness of will

At least since the middle of the twentieth century, philosophers have tended to identify weakness of will with akrasia—i.e. acting, or having a disposition to act, contrary to one’s judgments about what is best for one to do. However, there has been some recent debate about whether this captures the ordinary notion of weakness of will. Richard Holton claims that it doesn’t, while Alfred Mele argues that, to a certain extent, it does. As Mele recognizes, the question about an ordinary concept here is one apt for empirical investigation. We evaluate Mele’s studies and report some experiments of our own in order to investigate what in the world the ordinary concept of weakness of will is. We conclude that neither Mele nor Holton (previously) was quite right and offer a tentative proposal of our own: the ordinary notion is more like a prototype or cluster concept whose application is affected by a variety of factors.
Prognostic value of changes in quality of life scores in prostate cancer

Several studies in the oncology literature have demonstrated the prognostic value of baseline quality of life (QoL). We investigated whether changes in QoL could predict survival in prostate cancer patients. We evaluated 250 prostate cancer patients treated at our institution between Jan 2001 and Dec 2009 who were available for a minimum follow-up of 3 months. QoL was evaluated at baseline and after 3 months of treatment initiation using EORTC-QLQ-C30. Cox regression evaluated the prognostic significance of baseline and changes in QoL scores after adjusting for relevant clinical and demographic variables. Median overall survival was 89.1 months (95% CI: 56.5-121.7). Baseline QoL scale predictive of survival upon multivariate analysis was fatigue (p = 0.001). Associations between changes in QoL and survival, upon multivariate analysis, were observed for dyspnea and cognitive functioning. Every 10-point increase (worsening) in dyspnea was associated with a 16% increased risk of death (HR = 1.16; 95% CI = 1.02 to 1.30, p = 0.02), and every 10-point increase (improvement) in cognitive functioning was associated with a 24% decreased risk of death (HR = 0.76; 95% CI = 0.54 to 0.98, p = 0.04). This study provides preliminary evidence to indicate that prostate cancer patients with better baseline fatigue and patients whose dyspnea and cognitive functioning improves within 3 months of treatment are at a significantly decreased risk of mortality.
Efficient Querying of Periodic Spatiotemporal Objects

In this paper we propose a new data model called periodic spatiotemporal objects (PSOs) databases. We show that relational algebra can be extended to PSO databases and any fixed relational algebra queries can be evaluated in PTIME in the size of any input database. We also describe a database system implementation of the PSO model and several sample queries.
Recent development of thin film materials for magnetic heads

Recent developments of soft magnetic film materials in the past decade are reviewed. Approximately 20 kinds of alloy systems with high saturation induction of more than 10 kG have been reported in the last decade, although there were only three conventional head materials: Mn-Zn ferrite, Permalloy, and Sendust. A particular focus of the review is nanocrystalline films and multilayer films. Also reviewed are improvements in single-layer homogeneous films of Fe, Fe-Si, Sendust, and Fe/sub 16/N/sub 2/. Almost all the materials reported are Fe-based alloys, and some alloys are nitrogen related: iron-nitride compounds or nitrogen-containing alpha -Fe or Sendust. >
Forcing of oceanic mean flows by dissipating internal tides

We present a theoretical and numerical study of the effective mean force exerted on an oceanic mean flow due to the presence of small-amplitude internal waves that are forced by the oscillatory flow of a barotropic tide over undulating topography and are also subject to dissipation. This extends the classic lee-wave drag problem of atmospheric wave‐mean interaction theory to a more complicated oceanographic setting, because now the steady lee waves are replaced by oscillatory internal tides and, most importantly, because now the three-dimensional oceanic mean flow is defined by time averaging over the fast tidal cycles rather than by the zonal averaging familiar from atmospheric theory. Although the details of our computation are quite different, we recover the main action-at-a-distance result from the atmospheric setting, namely that the effective mean force that is felt by the mean flow is located in regions of wave dissipation, and not necessarily near the topographic wave source. Specifically, we derive an explicit expression for the effective mean force at leading order using a perturbation series in small wave amplitude within the framework of generalized Lagrangian-mean theory, discuss in detail the range of situations in which a strong, secularly growing mean-flow response can be expected, and then compute the effective mean force numerically in a number of idealized examples with simple topographies.
Quantifying offshore wind resources from satellite wind maps: study area the North Sea

Offshore wind resources are quantified from satellite synthetic aperture radar (SAR) and satellite scatterometer observations at local and regional scale respectively at the Horns Rev site in Denmark. The method for wind resource estimation from satellite observations interfaces with the wind atlas analysis and application program (WAsP). An estimate of the wind resource at the new project site at Horns Rev is given based on satellite SAR observations. The comparison of offshore satellite scatterometer winds, global model data and in situ data shows good agreement. Furthermore, the wake effect of the Horns Rev wind farm is quantified from satellite SAR images and compared with state-of-the-art wake model results with good agreement. It is a unique method using satellite observations to quantify the spatial extent of the wake behind large offshore wind farms. Copyright © 2006 John Wiley & Sons, Ltd.
Use of a chelating agent to determine the metal availability for leaching from soils and wastes

Abstract Constituent availability, or the potentially mobile fraction of the total content, is an important characterization parameter for waste materials and soils. The availability of inorganic species is often evaluated from the results of a sequential extraction procedure at a high liquid-to-solid (LS) ratio using pH control. Several tests maintain pH at 4 and 7 to maximize the solubility of cations and anions, respectively. An alternative procedure for measuring inorganic availability was developed using ethylene diamine tetraacetic acid (EDTA) as a chelating agent to eliminate the need for rigorous pH control. Analysis of variance was used to optimize the conditions of the EDTA availability procedure with respect to LS ratio, contact time and the concentration of EDTA in the leachant. The optimized procedure is a single batch extraction of particle size reduced material at near-neutral pH that may be used to determine the availability of both cations and anions. Optimized test conditions were determined to consist of a solution of 50 mM EDTA at an LS ratio of 100 ml/g dry for a contact time of 48 h. Availability values of arsenic, cadmium, copper, manganese and lead from four solid materials were determined in parallel using the optimized EDTA method and a two-step, static pH extraction at pH 7.0 and 4.0. The characterized waste materials represent common waste types in both treated and untreated forms. As determined by the EDTA procedure, the entire total content of contamination elements such as As, Cd, and Pb was found available for release whereas only a fraction of typical mineral substitution elements like Cu and Mn was found to be available. Comparison to the two-step static pH approach showed that significantly greater availability was observed using the EDTA method for all test cases. Since the extraction conditions under which availability was measured differed greatly between the protocols and to a large extent “availability” is operationally defined, it was impossible to conclude that one method was more rigorous than the other. Thus, it could be said that both approaches measure a different operationally defined availability of inorganic constituents in the tested materials.
Synthesis of unexpected nitrogen heterocycles via Pd-catalyzed cross-coupling of o-isopropenyl and methallyl anilides with vinylic halides

Abstract The palladium-catalyzed cross-coupling of o -isopropenyl and o -methallyl- N -tosylanilides with vinylic halides affords good yields of unexpected substituted dihydroquinolines and dihydroindoles respectively, apparently via vinylpalladium addition to the olefin and an unusual rearrangement to a π-allylpalladium intermediate.
Effect of electron energy distribution function on the global model for high power microwave breakdown at high pressures

Most volume-averaged global models assume a Maxwellian distribution for the electron energy distribution function (EEDF) in plasma discharges. The electrons, however, are not in the equilibrium in most discharges unless the electron-electron collision is dominant. The assumption of a Maxwellian EEDF can result in inaccurate reaction rate coefficients for the plasma discharge and lead to the wrong breakdown behavior prediction. Since the collisional plasma properties strongly depend on those coefficients, they are important to predict the plasma breakdown properly. This work will demonstrate the effect of the EEDF on the global model and propose a method to find an approximation of the EEDF that can improve the fidelity of the global model for prediction of high power microwave (HPM) breakdown in the high pressure regime.
Jockeying for Position: Strategic High School Choice Under Texas' Top Ten Percent Plan

Abstract Beginning in 1998, all students in the state of Texas who graduated in the top 10% of their high school classes were guaranteed admission to any in-state public higher education institution, including the flagships. While the goal of this policy is to improve college access for disadvantaged and minority students, the use of a school-specific standard to determine eligibility could have unintended consequences. Students may increase their chances of being in the top 10% by choosing a high school with lower-achieving peers. Our analysis of students' school transitions between 8th and 10th grade three years before and after the policy change reveals that this incentive influences enrollment choices in the anticipated direction. Among the subset of students with both motive and opportunity for strategic high school choice, at least 5% enroll in a different high school to improve the chances of being in the top 10%. These students tend to choose the neighborhood high school in lieu of transferring to more competitive schools and, regardless of own race, typically displace minority students from the top 10% pool. Relatively few students have both the motive and opportunity to behave strategically in the short run, so systemic effects are inherently slight. Our finding of sizable take-up in the face of costly strategizing, however, suggests that endogenous group membership may be important in the longer run and in other settings where individuals can select their peers and are then “graded on a curve.”
The design and performance of Mobile TCP for wireless networks

In this paper, we propose a novel approach to reduce the wireless communication overhead associated with the transport layer. Portability is a key element of mobile computing. As mobile devices shrink in terms of size and weight, their computing capabilities are also reduced, constrained by battery capacity. To sustain a good performance level of mobile applications, we devise a solution that reduces the processing complexity on computing-limited mobile devices. Additionally, we aim to minimize the use of wireless resources to further improve performance. Specifically, we develop a streamlined protocol architecture, Mobile TCP (MTCP), that achieves the elimination of IP processing on the wireless segment of the TCP connection. MTCP operates over a single hop wireless link, and, consequently, it eliminates the unnecessary overhead placed on mobile devices, such as the TCP congestion control mechanisms. In addition, we investigate the impact of streamlining the socket layer on offloading the processing overhead. Our experimental results indicate a substantial improvement in the efficiency of protocol processing. For instance, results show that the MTCP processing time per packet is approximately only one fourth that of TCP and the use of CPU resources is reduced by up to 50p. Furthermore, the protocol incorporates various robust, yet simple, loss recovery techniques to considerably improve the throughput in lossy wireless conditions.
A Portfolio of Nutrients: Soil and Sustainability

A Portfolio of Nutrients: Soil and Sustainability Craig A. Bond Department of Agricultural and Resource Economics University of California, Davis Davis, CA 95616 bond@primal.ucdavis.edu Y. Hossein Farzin Department of Agricultural and Resource Economics University of California, Davis Davis, CA 95616 farzin@primal.ucdavis.edu Selected Paper prepared for presentation at the American Agricultural Economics Association Annual Meeting, Denver, Colorado, August 1-4, 2004 Copyright 2004 by Bond and Farzin. All rights reserved. Readers may make verbatim copies of this document for non-commercial purposes by any means, provided that this copyright notice appears on all such copies.
Broadband coherent light generation in a Raman-active crystal driven by two-color femtosecond laser pulses

We demonstrate broadband light generation by focusing two-color ultrashort laser pulses into a Raman-active crystal, lead tungstate (PbWO4). As many as 20 anti-Stokes and 2 Stokes fields are generated due to strong near-resonant excitation of a Raman transition. The generated spectrum extends from the infrared, through the visible region, to the ultraviolet, and it consists of discrete spatially separated sidebands. Our measurements confirm good mutual spatial and temporal coherence among the generated fields and open possibilities for synthesis of subfemtosecond light waveforms.
Short and long-term mortality with nesiritide

Background Nesiritide (recombinant human B-type natriuretic peptide) has been shown to provide symptomatic and hemodynamic improvement in acute decompensated heart failure. A previous meta-analysis of 3 randomized controlled trials has suggested an increased short-term risk of death with nesiritide use. We performed a meta-analysis of 7 available randomized controlled trials to evaluate the short- and long-term risk of death with nesiritide use for acute decompensated heart failure. Methods Seven large randomized controlled nonmortality trials on nesiritide with available data on 30-day mortality were included. Data on 180-day mortality were available only in 4 trials. Mortality data in nesiritide and control arms were extracted from the selected trials and the nesiritide database (Scios Inc, Fremont, CA). Results The pooled estimate of the relative risks (RRs) for unadjusted 30- and 180-day mortality revealed no significant differences between the nesiritide arm (RR 1.243, 95% CI 0.798-1.935) and control arm (RR, 0.002, 95% CI 0.798-1.259), respectively). Conclusions Unlike a previous analysis, our meta-analysis indicates that nesiritide is not associated with a higher 30- or 180-day mortality. Further analysis of mortality adjusted for confounding variables such as nesiritide dose, duration of infusion, concurrent use of inotropes, heart failure stage, and arrhythmias may reveal subgroups in jeopardy. Large-scale randomized controlled trials powered to evaluate mortality are required to conclusively address these findings.
Combinatorial complexity and dynamical restriction of network flows in signal transduction

The activities and interactions of proteins that govern the cellular response to a signal generate a multitude of protein phosphorylation states and heterogeneous protein complexes. Here, using a computational model that accounts for 307 molecular species implied by specified interactions of four proteins involved in signalling by the immunoreceptor FcepsilonRI, we determine the relative importance of molecular species that can be generated during signalling, chemical transitions among these species, and reaction paths that lead to activation of the protein tyrosine kinase (PTK) Syk. By all of these measures and over two- and ten-fold ranges of model parameters--rate constants and initial concentrations--only a small portion of the biochemical network is active. The spectrum of active complexes, however, can be shifted dramatically, even by a change in the concentration of a single protein, which suggests that the network can produce qualitatively different responses under different cellular conditions and in response to different inputs. Reduced models that reproduce predictions of the full model for a particular set of parameters lose their predictive capacity when parameters are varied over two-fold ranges.
Nonlinear dynamics of ion concentration polarization in porous media: The leaky membrane model

The conductivity of highly charged membranes is nearly constant, due to counterions screening pore surfaces. Weakly charged porous media, or “leaky membranes,” also contain a significant concentration of coions, whose depletion at high current leads to ion concentration polarization and conductivity shock waves. To describe these nonlinear phenomena in the absence of electro-osmotic flow, a simple leaky membrane model is formulated, based on macroscopic electroneutrality and Nernst–Planck ionic fluxes. The model is solved in cases of unsupported binary electrolytes: steady conduction from a reservoir to a cation-selective surface, transient response to a current step, steady conduction to a flow-through porous electrode, and steady conduction between cation-selective surfaces in cross flow. The last problem is motivated by separations in leaky membranes, such as shock electrodialysis. The article begins with a tribute to Neal Amundson, whose pioneering work on shock waves in chromatography involved similar mathematics. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3539–3555, 2013
Nonblocking and Orphan-Free Message Logging Protocols

Currently existing message logging protocols demonstrate a classic pessimistic vs. optimistic tradeoff. It is shown that the optimistic-pessimistic tradeoff is not inherent to the problem of message logging. The authors construct a message-logging protocol that has the positive features of both optimistic and pessimistic protocols: the protocol prevents orphans and allows simple failure recovery; however, it requires no blocking in failure-free runs. Furthermore, this protocol does not introduce any additional message overhead as compared to one implemented for a system in which messages may be lost but processes do not crash.
Effect of various surface-height-distribution properties on acoustic backscattering statistics

A problem of interest to underwater acousticians is understanding the relationship between ocean-bottom characteristics and acoustic backscattering statistics. This experimental work focused on examining surface roughness characteristics that cause backscattering strength statistics to deviate from the Rayleigh distribution. Several different scattering surfaces with known height distributions were designed for this study. The surfaces were modeled using a technique that allowed for different height-distribution functions and correlation lengths to be prescribed. Isotropic and anisotropic surfaces were fabricated having both Gaussian and non-Gaussian surface-height distributions. Many independent backscattering measurements were made for different aspects of each surface using a computer-controlled transducer-positioning system. Acoustic backscattering statistics were non-Rayleigh for the anisotropic surfaces when combining measurements from different aspects. Mean scattering strength was found to be dependent on both the surface-height distribution and correlation length. In addition, backscattering strength showed a dependence on the surface-height power distribution.
Placental Alkaline Phosphatase Appearance in Murine Lymphomas

Alkaline phosphatase (APase) has been shown to have a membrane-bound localization in the murine fetal thymus, murine thymic lymphoma and in areas of lymphoproliferation of the adult spleen. A detailed biochemical comparison of the lymphoma APase with the fetal thymus, placenta, and spleen APases was performed. The parameters investigated were pH optimum, activation, inhibition, heat inactivation and substrate ratio with the substrate α-naphthyl phosphate. All four murine APase activities have a pH optimum of 10 and were activated by magnesium and nucleophilic buffers to the same extent. The APase activities tested were all inhibited by ethylenediamine tetraacetic acid, L-phenylalanine and L-homoarginine at the same levels, approximately 97%, 8% and 81%, respectively. Substrate ratios indicate that all four APases hydrolyzed both p-nitrophenyl phosphate and α-naphthyl phosphate at the same rate. These data lead one to conclude that the APase of murine thymic lymphoma may represent a cell membrane carcinofetal enzyme.
Estimates and existence results for a fully nonlinear Yamabe problem on manifolds with boundary

In this paper we consider a fully nonlinear version of the Yamabe problem on compact Riemannian manifold with boundary. Under various conditions we derive local estimates for solutions and establish some existence results.
Performance analysis of server sharing collectives for content distribution

Demand for content served by a provider can fluctuate with time, complicating the task of provisioning serving resources so that requests for its content are not rejected. One way to address this problem is to have providers form a collective in which they pool together their serving resources to assist in servicing requests for one another's content. In this paper, we determine the conditions under which a provider's participation in a collective reduces the rejection rate of requests for its content - a property that is necessary for such a provider to justify its participation within the collective. We show that all request rejection rates are reduced when the collective is formed from a homogeneous set of providers, but that some rates can increase within heterogeneous sets. We also show that, asymptotically, growing the size of the collective will sometimes, but not always, resolve this problem. We explore the use of thresholding techniques, where each collective participant sets aside a portion of its serving resources to serve only requests for its own content. We show that thresholding allows a more diverse set of providers to benefit from the collective model, making collectives a more viable option for content delivery services.
Fluctuation-theory constraint for extensive entropy in Monte-Carlo simulations

The entropy per particle in most Monte-Carlo simulations is size dependent due to correlated energy fluctuations. Guided by nanothermodynamics, we find a constraint for the Ising model that enhances the fluctuations and lowers the free energy, while making the entropy homogeneous, additive, and extensive. Although the average interaction energy becomes size dependent, the resulting distribution of energies provides a mechanism for the heterogeneity found in the dynamics of many materials.
Mechanism of Strength Degradation for Hot Corrosion of α‐SiC

Sintered alpha SiC was corroded by thin films of Na2SO4 and Na2CO3 molten salts at 1000 percent. This hot corrosion attack reduced room temperature strengths by as much as 50 percent. Strength degradation was proportional to the degree and uniformity of corrosion pitting attack as controlled by the chemistry of the molten salt. Extensive fractography identified corrosion pits as the most prevalent source of failure. A fracture mechanics treatment of the strength/pit depth relationship produced an average K sub IC equal to 2.6 MPa sub m 1/2, which is cnsistent ith published values.
Microwave Properties of Ba2Ti9O20 Doped with Zirconium and Tin Oxides

The effects of solid-solution additives, their concentration, and the thermal processing schedule on the microstructure evolution and microwave properties of Ba2Ti9O20 were studied. The solubility of tin in Ba2Ti9O20 was higher than that of zirconium. Both elements facilitated the formation of phase-pure Ba2Ti9O20 resonators. Ba2Ti9O20 formed most easily with low dopant concentrations (0.82 mol%) (most impressively for ZrO2 substitutions). Extended heat treatment (16 h versus 6 h at a temperature of 1390°C) resulted in volatilization of the grain-boundary liquid phase, which leads to more-porous resonators that have correspondingly lower permittivities. Increasing the dopant concentration resulted in minor increases in the quality factor; doping with zirconium led to slightly higher values (a maximum of 13900 at a frequency of 3 GHz). Increasing the measurement temperature degraded the quality factor (most precipitously for BaTi4O9). The temperature coefficient decreased as the ZrO2 substitution increased but was largely unaffected by the SnO2 concentration. Excess TiO2 in a batch with no other dopants demonstrated degraded microwave properties.
Arc-second alignment of International X-Ray Observatory mirror segments in a fixed structure

The optics for the International X-Ray Observatory (IXO) require alignment and integration of about fourteen thousand thin mirror segments to achieve the mission goal of 3.0 square meters of effective area at 1.25 keV with an angular resolution of five arc-seconds. These mirror segments are 0.4 mm thick, and 200 to 400 mm in size, which makes it hard to meet the strict angular resolution requirement of 5 arc-seconds for the telescope. This paper outlines the precise alignment, verification testing, and permanent bonding techniques developed at NASA's Goddard Space Flight Center (GSFC). These techniques are used to overcome the challenge of transferring thin mirror segments from a temporary mount to a fixed structure with arc-second alignment and minimal figure distortion. Recent advances in technology development in addition to the automation of several processes have produced significant results. Recent advances in the mirror fixture process known as the suspension mount has allowed for a mirror to be mounted to a fixture with minimal distortion. Once on the fixture, mirror segments have been aligned to around 5 arc-seconds which is halfway to the goal of 2.5 arc-seconds per mirror segment. This paper will highlight the recent advances in alignment, testing, and permanent bonding techniques as well as the results they have produced. 12
Comparing Gains and Losses

Loss aversion in choice is commonly assumed to arise from the anticipation that losses have a greater effect on feelings than gains, but evidence for this assumption in research on judged feelings is mixed. We argue that loss aversion is present in judged feelings when people compare gains and losses and assess them on a common scale. But many situations in which people judge and express their feelings lack these features. When judging their feelings about an outcome, people naturally consider a context of similar outcomes for comparison (e.g., they consider losses against other losses). This process permits gains and losses to be normed separately and produces psychological scale units that may not be the same in size or meaning for gains and losses. Our experiments show loss aversion in judged feelings for tasks that encourage gain-loss comparisons, but not tasks that discourage them, particularly those using bipolar scales.
Bounded gaps between primes in Chebotarev sets

A new and exciting breakthrough due to Maynard establishes that there exist infinitely many pairs of distinct primes p1, p2 with |p1-p2| ≤ 600 as a consequence of the Bombieri-Vinogradov Theorem. In this paper, we apply his general method to the setting of Chebotarev sets of primes. We use recent developments in sieve theory due to Maynard and Tao in conjunction with standard results in algebraic number theory. Given a Galois extension , we prove the existence of bounded gaps between primes p having the same Artin symbol . We study applications of these bounded gaps with an emphasis on ranks of prime quadratic twists of elliptic curves over , congruence properties of the Fourier coefficients of normalized Hecke eigenforms, and representations of primes by binary quadratic forms. Primary 11N05; 11N36; Secondary 11G05
Individual teacher incentives and student performance

This paper is the first to systematically document the relationship between individual teacher performance incentives and student achievement using the United States data. We combine data from the National Education Longitudinal Survey on schools, students, and their families with our own survey conducted in 2000 regarding the use of teacher incentives. This survey on teacher incentives has unique data on frequency and magnitude of merit raises and bonuses, teacher evaluation, and teacher termination. We find that test scores are higher in schools that offer individual financial incentives for good performance. Moreover, the estimated relationship between the presence of merit pay in teacher compensation and student test scores is strongest in schools that may have the least parental oversight. The association between teacher incentives and student performance could be due to better schools adopting teacher incentives or to teacher incentives eliciting more effort from teachers; it is impossible to rule out the former explanation with our cross sectional data.
Dark Matter and the LHC

An abundance of astrophysical evidence indicates that the bulk of matter in the universe is made up of massive, electrically neutral particles that form the dark matter (DM). While the density of DM has been precisely measured, the identity of the DM particle (or particles) is a complete mystery. In fact, within the laws of physics as we know them (the Standard Model, or SM), none of the particles have the right properties to make up DM. Remarkably, many new physics extensions of the SM — designed to address theoretical issues with the electroweak symmetry breaking sector — require the introduction of new particles, some of which are excellent DM candidates. As the LHC era begins, there are high hopes that DM particles, along with their associated new matter states, will be produced in pp collisions. We discuss how the LHC experiments, along with other DM searches, may serve to determine the identity of DM particles and elucidate the associated physics. Most of our discussion centres around theories with weak-scale supersymmetry, and allows for several different DM candidate particles.
Development of an in vitro clonogenic assay for the R3327 rat prostatic adenocarcinoma permits comparison of the proliferative potential of the R3327, R3327A, and R3327AT tumors

The R3327 class of rat prostate tumors consists of both the androgen-dependent R3327 adenocarcinoma and androgen-independent sublines, the R3327At spindle cell tumor, and the R3327A, a squamous cell carcinoma. We have developed in vitro clonogenic cell assays to measure and compare systematically the proliferative potential of these tumors following various monodispersion techniques. Linear relationships between the number of monodispersed tumor cells cultured at low cell density and the number of colonies formed 10 days later establish these assays as the first quantitative cellular approach to those proliferative subpopulations ultimately responsible for the growth of these tumors. We have chosen the name colony forming cell-prostatic adenocarcinoma (CFC-PA) to refer to the members of the proliferative subpopulation of the R3327 tumor. An ultrastructurd comparison of R3327 adenocarcinoma tissue sections with the cells produced during culture provides evidence that the cells of the proliferative subpopulation may be derived from the acinar epithelium of the tumor.
Surface tension prediction for pure fluids

In this paper we propose the following expression for surface tension of organic compounds: σ = [P . (ρ l - ρ v )] 4 where P = P o . (1-Tr) 0.37. Tr . Exp(0.30066/Tr + 0.86442 . Tr9) In this equation ρl and ρv are the molar densities of liquid and vapor, respectively, Tr=T/Tc, Po is a temperature-independent compound-dependent constant similar to the Sugden's parachor. This new expression, originally derived from the statistical-mechanics is shown to represent the experimental surface tension data of 94 different organic compounds within 1.05 AAD%. We also propose P o = 39.6431.[0.22217 - 2.91042 x 10-3.(R*/Tbr2)].Tc13/12 /Pc5/6
Optimization of importance factors and desired doses in a quadratic dose objective function

The Least Square dose Objective function (LSO) is widely used in radiotherapy optimization. In LSO optimization, usually importance factors are assigned to individual regions of interest (ROI). The relative values of importance factors directly affect results of LSO optimization and thus It is important to find proper importance factors. Here, a method of searching optimum voxel based importance factors is introduced. First, each voxel is assigned with its own importance factor. Then the whole set of importance factors is updated systematically to generate better optimization results. The method was tested in a simplified 3D setup. It is shown by comparison with DVHs and isodose plots that the updating importance factor method has potential of improving optimized dose distribution significantly. In order to improve the method's computational efficiency, an equivalent computational efficient algorithm is proposed. In the equivalent algorithm, the desired doses in LSO objective function are updated while importance factors are kept fixed. The authors expect to see similar optimized dose distribution improvement from implementation of this equivalent algorithm.
Historical Demography and the Crisis of the Seventeenth Century

The seventeenth century, broadly conceived, marks an important turning point in the history of European population movements. Long cycles characterized, first, by population expansion and subsequently by mortality contractions due to famine or disease held long-term population growth largely in check. The subsistence and mortality crises of the middle decades of the seventeenth century and the fundamental shift in the capacity of the European population to grow after 1750 together suggest that the case for a “general crisis of the seventeenth century” has strong demographic support.