cssi/SciSciGPT-SciSciNet huggingface dataset:
Estimating the Costs and Benefits of Cattle Traceability: the Case of the Quebec Cattle Traceability System

Animal identification and animal traceability have lept to the front of the food policy agenda. The ongoing implementation of the National Animal Identification System in United States has raised concerns over the costs and benefits of implementing and maintaining such a system. In this paper, we lay the foundations for estimating the costs and benefits of implementing cattle traceability in Quebec. Our results could eventually be used to estimate the costs and benefits of adopting a similar system in the United States.
Stochastic trade policy with asset markets: The role of tariff structure

Abstract This paper uses a Stockman-Dellas type two-country, two-good, stochastic general equilibrium model to consider the effects of commercial policy when asset markets are complete. We show that: (i) import and export tariffs do not have symmetric effects because interstate relative prices depend on the entire tariff structure; (ii) when commercial policy is random and exogenously determined, the ex post comparison of utility across states depends upon whether import or export tariffs are used; and (iii) when endowments are random, implying the optimal tariff varies across states, the introduction of asset markets may be welfare-reducing when only import tariffs are used.
Curious and creative machines

Can machines ask questions and generate hypotheses? Despite the prevalence of big data, the process of distilling data into scientific laws has resisted automation. Particularly challenging are situations with small amounts of data that is difficult or expensive to collect, such as in robotics and other physical sciences. This talk will outline a series of recent research projects, starting with self-reflecting robotic systems, and ending with machines that can formulate hypotheses, design experiments, and interpret the results, to discover new scientific laws. We will see examples from geology to cosmology, from classical physics to modern physics, from big science to small science.
Measuring the Significance of Diversification Gains

This article investigates whether investing in alternative investment media provides statistically significant increases in portfolio performance. Employing methodology introduced by Kandel and Stambaugh (1987) and Gibbons, Ross and Shanken (1989), we measure the statistical significance of diversification gains for portfolios containing real and financial domestic assets, as well as international debt and equity issues. The NCREIF real estate series is further examined using the Geltner (1993) adjustment to the risk measure. In the 1978-93 sample period, neither international assets nor unadjusted real estate ever result in statistically significant increases in portfolio performance. When the Geltner adjustment is made, the allocation to real estate is substantially reduced in the expanded portfolio and also fails to result in a statistically significant increase in portfolio performance. These results may help to resolve the paradox between current portfolio allocations to real estate in practice and t...
Data placement in widely distributed environments

The increasing computation and data requirements of scientific applications, especially in the areas of bioinformatics, astronomy, high energy physics, and earth sciences, have necessitated the use of distributed resources owned by collaborating parties. While existing distributed systems work well for compute-intensive applications that require limited data movement, they fail in unexpected ways when the application accesses, creates, and moves large amounts of data over wide-area networks. Existing systems closely couple data movement and computation, and consider data movement as a side effect of computation. In this chapter, we propose a framework that de-couples data movement from computation, allows queuing and scheduling of data movement apart from computation, and acts as an I/O subsystem for distributed systems. This system provides a uniform interface to heterogeneous storage systems and data transfer protocols; permits policy support and higher-level optimization; and enables reliable, efficient scheduling of compute and data resources.
Wavelength division multiplexed systems and networks

Summary form only given. Optical Wavelength Division Multiplexing (WDM) has emerged as an extremely flexible and efficient technique for accessing the vast optical fiber bandwidth. It also allows the provision of various services and flexible upgrading in optical networks. Furthermore, there is emerging technology for high-capacity wavelength routing dynamically reconfigurable network applications. In this presentation, we cover topics related to some of the recently proposed architectures, and network components suitable for this important application area. >
Accessibility dynamics and location premia: Do land values follow accessibility changes?

The structure of transportation networks and the patterns of accessibility they give rise to are an important determinant of land prices, and hence urban spatial structure. While there is ample evidence on the cross-sectional relationship between location and land value (usually measured from the value of improved property), there is much less evidence available on the changes in this relationship over time, especially where location is represented using a disaggregate measure of urban accessibility. This paper provides evidence of this dynamic relationship using data on home sales in the Minneapolis-St Paul, MN, USA metropolitan area, coupled with disaggregate measures of urban accessibility for multiple modes, for the period from 2000 to 2005. Our investigation tracks the effects of marginal changes in accessibility over time, as opposed to static, cross-sectional relationships, by using an approach in which the unit of observation is a ‘representative house’ for each transportation analysis zone in the...
Zinc-Zinc Bonds: A New Frontier

Some metals readily form bonds to other atoms of the same element in molecular compounds, but others, such as zinc, are not known to do so. In his Perspective, [Parkin][1] highlights the discovery of a molecular compound with a zinc-zinc bond by [ Resa et al .][2] and places the discovery in the context of the other two elements in group 12 of the periodic table, cadmium and mercury. [1]: http://www.sciencemag.org/cgi/content/full/305/5687/1117 [2]: http://www.sciencemag.org/cgi/content/short/305/5687/1136
Multispectral discrimination of possible Martian surface constituents

In the 1970s attempts will be made to soft-land scientific instruments on the surface of Mars. The question of the employment of several spectral bands to improve discrimination is investigated. The studies conducted are concerned with the development of a technique for selecting color bands for a lander imaging system. Other study objects include the investigation of certain solid state detectors and the determination of the feasibility of minimizing the total number of telemetry bits from the lander by various means.
Dynamical systems method (DSM) for unbounded operators

Let L be an unbounded linear operator in a real Hilbert space H, a generator of a C 0 semigroup, and let g: H → H be a C 2 loc nonlinear map. The DSM (dynamical systems method) for solving equation F(v):= Lv + g(v) = 0 consists of solving the Cauchy problem u = Φ(t,u), u(0) = n 0 , where Φ is a suitable operator, and proving that i) 3u(t) Vt > 0, ii) 3u(oo), and iii) F(u(∞)) = 0. Conditions on L and g are given which allow one to choose Φ such that i), ii), and iii) hold.
VOLUME-COLLAPSE TRANSITIONS IN THE RARE EARTH METALS

We describe current experimental and theoretical understanding of the pressure-induced volume collapse transitions occurring in the early trivalent rare earth metals. General features of orbitally realistic mean-field based theories used to calculate these transitions are discussed. Potential deficiencies of these methods are assessed by comparing mean field and exact Quantum Monte Carlo solutions for the one-band Hubbard and two-band periodic Anderson lattice models. Relevant parameter regimes for these models are determined from local density constrained occupation calculations.
Trade and human capital accumulation: evidence from U.S. immigrants

This study provides empirical evidence that trade increases on-the-job human capital accumulation by estimating the effect of home country openness on estimated returns to home country experience of U.S. immigrants. The positive effect of trade on on-the-job human capital accumulation remains significant when controlling for GDP, educational attainment, and institutional quality. It is not the result of self-selection, heterogeneity in returns to experience, English-speaking origin, or cultural background. The effect persists when restricting the sample to non-OECD countries, thereby resolving the theoretical ambiguity of whether trade increases or decreases learning-by-doing. The role of trade in generating economic growth is therefore likely to be more important than generally considered.
SynchNet: a Petri net based coordination language for distributed objects

We present SynchNet, a compositional meta-level language for coordination of distributed. Its design is based on the principle of separation of concerns, namely separation of the coordination from computational aspects. SynchNet can be used in combination with any object-based language capable of expressing sequential behavior of objects. SynchNet, which is inspired by Petri nets, has a simple syntax and semantics, but is expressive enough to code many of the commonly used coordination patterns. The level of abstraction that it provides allows tools and techniques developed for Petri nets to be readily applied to analysis and verification of the specified coordination patterns.
The scientific community metaphor

Scientific communities have proven to be extremely successful at solving problems. They are inherently parallel systems and their macroscopic nature makes them amenable to careful study. In this paper the character of scientific research is examined drawing on sources in the philosophy and history of science. We maintain that the success of scientific research depends critically on its concurrency and pluralism. A variant of the language Ether is developed that embodies notions of concurrency necessary to emulate some of the problem solving behavior of scientific communities. Capabilities of scientific communities are discussed in parallel with simplified models of these capabilities in this language.
PEERING THROUGH THE MUCK: NOTES ON THE INFLUENCE OF THE GALACTIC INTERSTELLAR MEDIUM ON EXTRAGALACTIC OBSERVATIONS

This paper considers some effects of foreground Galactic gas on radiation received from extragalactic objects, with an emphasis on the use of the 21cm line to determine the total N HI . In general, the opacity of the 21cm line makes it impossible to derive an accurate value of N HI by simply applying a formula to the observed emission, except in directions where there is very little interstellar matter. The 21cm line can be used to estimate the likelihood that there is significant if H 2 in a particular direction, but carries little or no information on the amount of ionized gas, which can be a major source of foreground effects. Considerable discussion is devoted to the importance of small-scale angular structure in HI, with the conclusion that it will rarely contribute significantly to the total error compared to other factors (such as the effects of ionized gas) for extragalactic sight lines at high Galactic latitude. The direction of the Hubble/Chandra Deep Field North is used as an example of the complexities that might occur even in the absence of opacity or molecular gas.
How Can We Make Sure We Detect Dark Matter

More and more claims of having detected WIMP dark matter are being put forward. Some are discussed here, stressing the importance of exploiting distinctive signatures to ascertain their WIMP origin. The best signals for WIMP discovery are characterized by special features that make them recognizable as due to WIMPs and nothing else. Sometimes, however, a single feature, although accountable for in theoretical models, may not be enough to make sure that we have detected WIMPs. This is because the theory of WIMPs and their distribution in the galaxy is still very uncertain, and allows for many possibilities. What are needed are experimental verifications of the claimed signals, either by discovering unmistakable features, or by detecting several kinds of signals that can all be explained by the same WIMP model.
Detection of two binary trans-Neptunian objects, 1997 CQ29 and 2000 CF105 with the Hubble Space Telescope

Images of the trans-Neptunian objects 1997 CQ29 and 2000 CF105 obtained with the Hubble Space Telescope WFPC2 camera show them to be binary. The two components of 1997 CQ29 were separated in our images by 020 ± 003 in 2001 November and by 033 ± 001 in 2002 June/July. The corresponding minimum physical distances are 6100 and 10,200 km. The companion to 2000 CF105 was 078 ± 003 from the primary, at least 23,400 km. Six other objects in the trans-Neptunian region, including Pluto and its moon Charon, are known to be binaries; 1997 CQ29 and 2000 CF105 are the seventh and eighth known pair. Binarity appears to be a not uncommon characteristic in this region of the solar system, with detectable companions present in 4% ± 2% of the objects we have examined.
On Quantum de Rham Cohomology Theory

We define quantum exterior product wedge_h and quantum exterior differential d_h on Poisson manifolds (of which symplectic manifolds are an important class of examples). Quantum de Rham cohomology, which is a deformation quantization of de Rham cohomology, is defined as the cohomology of d_h. We also define quantum Dolbeault cohomology. A version of quantum integral on symplectic manifolds is considered and the correspoding quantum Stokes theorem is proved. We also derive quantum hard Lefschetz theorem. By replacing d by d_h and wedge by wedge_h in the usual definitions, we define many quantum analogues of important objects in differential geometry, e.g. quantum curvature. The quantum characteristic classes are then studied along the lines of classical Chern-Weil theory. Quantum equivariant de Rham cohomology is defined in the similar fashion.
The Saxl conjecture and the dominance order

In 2012 Jan Saxl conjectured that all irreducible representations of the symmetric group occur in the decomposition of the tensor square of the irreducible representation corresponding to the staircase partition. We make progress on this conjecture by proving the occurrence of all those irreducibles which correspond to partitions that are comparable to the staircase partition in the dominance order. Moreover, we use our result to show the occurrence of all irreducibles corresponding to hook partitions. This generalizes results by Pak et?al. (2013).
Counterexamples to Kalai's conjecture C

We provide two simple counterexamples to Kalai's Conjecture C and discuss our perspective on the implications for the prospect of large-scale fault-tolerant quantum computation.
Pointwise Asymptotic Behavior of Perturbed Viscous Shock Profiles

We consider the asymptotic behavior of perturbations of Lax and overcompressive-type viscous shock profiles arising in systems of regularized conservation laws with strictly parabolic viscosity, and also in systems of conservation laws with partially parabolic regularizations such as arise in the case of the compressible Navier--Stokes equations and in the equations of magnetohydrodynamics. Under the necessary conditions of spectral and hyperbolic stability, together with transversality of the connecting profile, we establish detailed pointwise estimates on perturbations from a sum of the viscous shock profile under consideration and a family of diffusion waves which propagate perturbation signals along outgoing characteristics. Our approach combines the recent $L^p$-space analysis of Raoofi [33] with a straightforward bootstrapping argument that relies on a refined description of nonlinear signal interactions, which we develop through convolution estimates involving Green's functions for the linear evolutionary PDE that arises upon linearization of the regularized conservation law about the distinguished profile. Our estimates are similar to, though slightly weaker than, those developed by Liu in his landmark result on the case of weak Lax-type profiles arising in the case of identity viscosity [21].
The Lazy Bureaucrat scheduling problem

We introduce a new class of scheduling problems in which the optimization is performed by the worker (single "machine") who performs the tasks. A typical worker's objective is to minimize the amount of work he does (he is "lazy"), or more generally, to schedule as inefficiently (in some sense) as possible. The worker is subject to the constraint that he must be busy when there is work that he can do; we make this notion precise both in the preemptive and nonpreemptive settings. The resulting class of "perverse" scheduling preblems, which we denote "Lazy Bureaucrat Problems," gives rise to a rich set of new questions that explore the distinction between maximization and minimization in computing optimal schedules.
Resource Allocation in Multiple Access Channels

We consider the problem of rate allocation in a Gaussian multiple-access channel, with the goal of maximizing a utility function over transmission rates. In contrast to the literature which focuses on linear utility functions, we study general concave utility functions. We present a gradient projection algorithm for this problem. Since the constraint set of the problem is described by exponentially many constraints, methods that use exact projections are computationally intractable. Therefore, we develop a new method that uses approximate projections. We use the polymatroid structure of the capacity region to show that the approximate projection can be implemented by a recursive algorithm in time polynomial in the number of users. We further propose another algorithm for implementing the approximate projections using rate-splitting and show improved bounds on its convergence time.
Line Versus Flux Statistics-Considerations for the Low Redshift Lyman-Alpha Forest

The flux/transmission power spectrum has become a popular statistical tool in studies of the high redshift (z > 2) Lyman-alpha forest. At low redshifts, where the forest has thinned out into a series of well-isolated absorption lines, the motivation for flux statistics is less obvious. Here, we study the relative merits of flux versus line correlations, and derive a simple condition under which one is favored over the other on purely statistical grounds. Systematic errors probably play an important role in this discussion, and they are outlined as well.
Isolation and characterization of the [Ga2Al18O8(OH)36(H2O)12]8+ cluster: cationic variations on the Wells–Dawson topology

The structural chemistry of Group 13 polyoxometalates lags far behind related negatively charged transition metal species and limits the development of advanced materials. A novel heterometallic cluster [Ga2Al18O8(OH)36(H2O)12]8+ (Ga2Al18) has been isolated using a supramolecular approach and structurally characterized using single-crystal X-ray diffraction. Ga2Al18 represents the Wells–Dawson structure polycations and variations in the structural topology may be related to the initial stabilization of the Keggin isomer. DFT calculations on the related e-Keggins (GaAl12 and Al13), Ga2Al18, and theoretical Al2Al18 clusters reveal similar features of electronic structure, suggesting additional heteroatom substitution in other isostructural clusters should be possible.
Synthesis of O- and N-alkylated products of 1,2,3,4-tetrahydrobenzo[c][2,7]naphthyrin-5(6H)-one

Efficient syntheses of O- and N-alkylated products of 1,2,3,4-tetrahydrobenzo[c][2,7]naphthyrin-5(6H)-one are presented. The O-alkylated analogues were synthesized through a reduction-cyclization cascade and a selective O-alkylation reaction; whereas the N-alkylated analogues were obtained through a key Buchwald coupling.
A World Without Privacy: Why Property Does Not Define the Limits of the Right Against Unreasonable Searches and Seizures

Imagine for a moment that it is the year 2020. An American company has developed a mind-reading device, called the "brain wave recorder" ("BWR"). The BWR is a highly sensitive instrument that detects electrical impulses from any brain within ten feet of the machine. Though previously thought impossible, the BWR can discern the following information about the target individual: (1) whether he or she is happy, sad, anxious, depressed, or irritable; (2) whether he or she is even slightly sexually aroused; (3) whether he or she is taking any medication (and if so, what the medication is); (4) if a female subject, whether she is pregnant; (5) whether he or she is experiencing a feeling of guilt or remorse; and (6) whether he or she is having aggressive impulses toward another person or persons. At this stage in its development, we do not know whether or not the BWR will advance beyond detection of this information and whether or not it will become generally available to the public. It is currently a technology that belongs exclusively to the government and to extremely wealthy private collectors. Under Professor Orin Kerr's provocative and interesting thesis,1 federal or state police could use the BWR on innocent people without implicating their Fourth Amendment rights against unreasonable
Interlacement in 4-regular graphs: a new approach using nonsymmetric matrices

Let $F$ be a 4-regular graph with an Euler system $C$. We introduce a simple way to modify the interlacement matrix of $C$ so that every circuit partition $P$ of $F$ has an associated modified interlacement matrix $M(C,P)$. If $C$ and $C^{\prime}$ are Euler systems of $F$ then $M(C,C^{\prime})$ and $M(C^{\prime},C)$ are inverses, and for any circuit partition $P$, $M(C^{\prime},P)=M(C^{\prime},C)\cdot M(C,P)$. This machinery allows for short proofs of several results regarding the linear algebra of interlacement.
A simple method for finding the scattering coefficients of quantum graphs

Quantum walks are roughly analogous to classical random walks, and similar to classical walks they have been used to find new (quantum) algorithms. When studying the behavior of large graphs or combinations of graphs, it is useful to find the response of a subgraph to signals of different frequencies. In doing so, we can replace an entire subgraph with a single vertex with variable scattering coefficients. In this paper, a simple technique for quickly finding the scattering coefficients of any discrete-time quantum graph will be presented. These scattering coefficients can be expressed entirely in terms of the characteristic polynomial of the graph’s time step operator. This is a marked improvement over previous techniques which have traditionally required finding eigenstates for a given eigenvalue, which is far more computationally costly. With the scattering coefficients we can easily derive the “impulse response” which is the key to predicting the response of a graph to any signal. This gives us a powerful set of tools for rapidly understanding the behavior of graphs or for reducing a large graph into its constituent subgraphs regardless of how they are connected.
Acute Isodense Subdural Hematomas: A Problem in Anemic Patients

Although numerous articles have appeared in the literature on chronic isodense subdural hematomas, acute isodense subdural hematomas have received little attention. An experimental model was developed that demonstrated that blood with reduced hemoglobin concentration, 8–10 g/dI, is isodense with the brain. Two anemic patients with acute isodense subdural hematomas are reported.
On the Accuracy and Running Time of GSAT

Randomized algorithms for deciding satisfiability were shown to be effective in solving problems with thousands of variables. However, these algorithms are not complete. That is, they provide no guarantee that a satisfying assignment, if one exists, will be found. Thus, when studying randomized algorithms, there are two important characteristics that need to be considered: the running time and, even more importantly, the accuracy -- a measure of likelihood that a satisfying assignment will be found, provided one exists. In fact, we argue that without a reference to the accuracy, the notion of the running time for randomized algorithms is not well-defined. In this paper, we introduce a formal notion of accuracy. We use it to define a concept of the running time. We use both notions to study the random walk strategy GSAT algorithm. We investigate the dependence of accuracy on properties of input formulas such as clause-to-variable ratio and the number of satisfying assignments. We demonstrate that the running time of GSAT grows exponentially in the number of variables of the input formula for randomly generated 3-CNF formulas and for the formulas encoding 3- and 4-colorability of graphs.
Some applications of polynomial optimization in operations research and real-time decision making

We demonstrate applications of algebraic techniques that optimize and certify polynomial inequalities to problems of interest in the operations research and transportation engineering communities. Three problems are considered: (1) wireless coverage of targeted geographical regions with guaranteed signal quality and minimum transmission power, (2) computing real-time certificates of collision avoidance for a simple model of an unmanned vehicle (UV) navigating through a cluttered environment, and (3) designing a nonlinear hovering controller for a quadrotor UV, which has recently been used for load transportation. On our smaller-scale applications, we apply the sum of squares (SOS) relaxation and solve the underlying problems with semidefinite programming. On the larger-scale or real-time applications, we use our recently introduced “SDSOS Optimization” techniques which result in second order cone programs. To the best of our knowledge, this is the first study of real-time applications of sum of squares techniques in optimization and control. No knowledge in dynamics and control is assumed from the reader.
Interferons Exhibit Temporally Distinct Regulation of Two Bovine Macrophage Fc Receptors

Interferon (IFN)-induced modulation of two distinct types of Fc receptors (FcR) on bovine bone marrow culture-derived macrophages was quantified by flow cytometry. We have established the presence of separate FcR for monomeric and aggregated IgG on these cells, equivalent to the FcRI and FcRII of mice, respectively. These two kinds of FcR differed in protease sensitivity, hierarchy of preferential binding of immunoglobulin sub-class, and cross-inhibition. Treatment of macrophages with either recombinant bovine IFN-gamma (rBoIFN gamma) or rBoIFN alpha I1 produced a dose-dependent increase in the expression of both types of FcR; however, expression of the FcR for aggregated IgG was increased a full 24 h prior to that for monomeric antibody. Further, expression of the FcRII-equivalent declined substantially by 48 h of IFN exposure, while the presence of the FcRI-equivalent receptor was still enhanced. Finally, low doses (1 unit/ml) of either rBoIFN gamma or rBoIFN alpha I1 failed to alter FcR expression, yet mixtures of IFNs at this concentration were able to potentiate FcR expression. This is the first time that a differential time course of induction of FcR types by IFNs and the effects of mixtures of IFNs on FcR expression has been described in any species.
Global Income Distribution and Poverty in the Absence of Agricultural Distortions

This paper assesses the potential impacts of the removal of agriculture trade distortions using a newly developed dataset and methodological approach for evaluating the global poverty and inequality effects of policy reforms. It finds that liberalization of agriculture and food could increase global extreme poverty (US$1 a day) by 0.2 percent and lower moderate poverty (US$2 a day) by 0.3 percent. Beneath these small aggregate changes, most countries witness a substantial reduction in poverty while South Asia-where half of the world's poor reside-experiences an increase in extreme poverty incidence due to high rates of protection afforded to unskilled-intensive agricultural sectors. The distributional changes are likely to be mild, but exhibit a strong regional pattern. Inequality is likely to fall in regions such as Latin America, which are characterized by high initial inequality, and rise in regions like South Asia, characterized by low initial inequality.
MONETARY POLICY WITH A WIDER INFORMATION SET: A BAYESIAN MODEL AVERAGING APPROACH

Monetary policy has been usually analyzed in the context of small macroeconomic models where central banks are allowed to exploit a limited amount of information. Under these frameworks, researchers typically derive the optimality of aggressive monetary rules, contrasting with the observed policy conservatism and interest rate smoothing. This paper allows the central bank to exploit a wider information set, while taking into account the associated model uncertainty, by employing Bayesian model averaging with Markov chain model composition. In this enriched environment, we derive the optimality of smoother and more cautious policy rates, together with clear gains in macroeconomic efficiency.
Response of California Current forcing to mid-Holocene insolation and sea surface temperatures

[1] We find that mid-Holocene insolation causes systematic changes in wind forcing of the California Current system, suppressing wind stress in the spring and enhancing wind stress in the summer and autumn. Both large- and regional-scale processes play an important role in the insolation enhancement of wind stress, with elevated summer insolation magnifying both large-scale sea level pressure gradients and regional-scale land-sea thermal contrast. We find that prescribed changes in large-scale sea surface temperatures (SSTs) amplify the response of nearshore wind stress to mid-Holocene insolation, with SST magnification of changes in large-scale sea level pressure gradients overcoming SST muting of changes in regional-scale land-sea thermal contrast. The climate model simulations are supported by proxy-inferred cooler-than-present sea surface temperatures in the northern California Current system, as well as by high nitrogen isotope values in the southern California Current system. Our results highlight the importance of multiscale dynamical interactions in regulating the response of regional environments to global-scale changes in radiative forcing.
The Strategist's Curse: A Theory of False Optimism as a Cause of War

This article proposes a new theory of false optimism as a cause of war. Named for its similarity to the winner's curse in auctions, this theory explains how and why established sources of misperception (cognitive, psychological, bureaucratic, and organizational) interact with the selection of one military strategy from a set of alternatives to produce a surprising amount of additional false optimism. Even if a state's general perceptions of how well it will fare in a potential war are not biased toward optimism, this theory explains why its perceptions of the particular strategy on which it will base its plans for fighting that war will be systematically biased toward optimism. Simulations and formal modeling confirm the logic of the theory and suggest that the strategist's curse can sharply increase the probability of war due to false optimism.
Direct Democracy and Local Public Goods: Evidence from a Field Experiment in Indonesia

This brief summarizes the direct democracy and local public goods: evidence from a field experiment in Indonesia for September 2005-January 2006. This article presents an experiment in which 49 Indonesian villages were randomly assigned to choose development projects through either representative-based meetings or direct election-based plebiscites. Plebiscites resulted in dramatically higher satisfaction among villagers, increased knowledge about the project, greater perceived benefits, and higher reported willingness to contribute. Changing the political mechanism had much smaller effects on the actual projects selected, with some evidence that plebiscites resulted in projects chosen by women being located in poorer areas. The results suggest that direct participation in political decision making can substantially increase satisfaction and legitimacy.
Evaluating prior learning assessment programs: A suggested framework

Over the past two decades, American institutions have been expected to include systematic program reviews to meet accrediting standards, either by independent or governmental review agencies. Program evaluation is critical for several reasons: it provides systematic ways to assess what needs improvement or what needs changing and it provides ways to validate practices, whether to internal or external audiences (Mishra, 2007). Most program evaluative models are focused on academic programs, which don’t fit the uniqueness of prior learning assessment programs. This paper proposes an evaluative framework for prior learning assessment programs, which takes into account the type of work within prior learning assessment programs and uses program portfolios, similar to how students are asked to document their work.
Is Accra a Superstar City

A recent study of house price behavior in U.S. cities by Gyourko, Mayer, and Sinai (2006) raises questions about so-called superstar cities in which housing is so inelastically supplied that it becomes unaffordable, as higher-income families outbid residents. We consider the case of Accra, Ghana, in this light, estimating the elasticity of housing supply and discussing the implications for growth and income distribution. There is not a great deal of data available to examine trends in Accra, so our method is indirect. First, we use a variant of the traditional monocentric city model to calculate the elasticity of Accra's housing supply relative to those of other similarly-sized African cities. This suggests that housing supply responsiveness is much higher elsewhere. This muted supply responsiveness is consistent with the observed higher housing prices. Second, we estimate a number of traditional housing demand equations and reduced form equations. Placing a number of restrictions on the equations allows us to infer Accra's housing supply elasticity. Taken together, our approaches suggest that lower-income families in Accra have such poor housing conditions because the market is extremely unresponsive to demand. Although the outcomes we have traced-high housing prices and low quality-are not unusual relative to the other developed country superstar cities, they are extreme. The welfare costs are considerable, so much so that in addition to direct housing market effects, these policies also appear to have potentially significant implications for the achievement of more equitable growth.
Mesoscale modelling of environmentally responsive hydrogels: emerging applications

Stimuli-sensitive hydrogels are an exciting class of materials with widespread potential for use in engineering and biomedical applications. The design of advanced functional devices using hydrogels requires an in-depth understanding of the physics and behaviour of such materials. While theoretical tools exist, they are often limited to simple cases. Thus, computational methods are necessary to model the complex unsteady physics of hydrogels with high fidelity. Mesoscale modelling is an emerging approach that enables simulations of polymeric structures at length and time scales in between those of molecular dynamics and continuum methods. In this feature article, we review various computational approaches to model responsive hydrogels and specifically focus on dissipative particle dynamics (DPD), a particle-based mesoscale method. We discuss several approaches for modelling cross-linked polymer networks in DPD, and describe recent applications of DPD to modelling hydrogel systems.
Synthesis, Structure, Thermoelectric Properties, and Band Gaps of Alkali Metal Containing Type I Clathrates: A8Ga8Si38 (A = K, Rb, Cs) and K8Al8Si38

A series of alkali metal containing compounds with type I clathrate structure, A8Ga8Si38 (A = K, Rb, Cs) and K8Al8Si38, were synthesized and characterized. Room temperature lattice parameters of A8Ga8Si38 (A = K, Rb, Cs) and K8Al8Si38 were determined to be 10.424916(10), 10.470174(13), 10.535069(15), and 10.48071(2) A, respectively. The type I clathrate structure (cubic, Pm3n) was confirmed for all phases, and in the case of K8Al8Si38 and K8Ga8Si38, the structures were also refined using synchrotron powder diffraction data. The samples were consolidated by Spark Plasma Sintering (SPS) for thermoelectric property characterization. Electrical resistivity was measured by four probe AC transport method in the temperature range of 30 to 300 K. Seebeck measurements from 2 to 300 K were consistent with K8Al8Si38 and K8Ga8Si38 being n-type semiconductors, while Rb8Ga8Si38 and Cs8Ga8Si38 were p-type semiconductors. K8Al8Si38 shows the lowest electrical resistivity and the highest Seebeck coefficient. This phase a...
Characterizing the U–Pb systematics of baddeleyite through chemical abrasion: application of multi-step digestion methods to baddeleyite geochronology

U–Pb baddeleyite geochronology has become a major tool for dating mafic rocks, especially dikes associated with Large Igneous Provinces. However, in many cases, post-crystallization Pb-loss and intergrowth of baddeleyite and zircon limit the precision and/or accuracy of crystallization ages. We present results from multi-step digestion experiments designed to understand and reduce these effects. Experiments were carried out on Neoproterozoic baddeleyites with zircon inter- and over-growths from the Gannakouriep dike swarm, Namibia, and on fragments of a large Paleoproterozoic baddeleyite from the Phalaborwa carbonatite, South Africa. Multi-step digestion experiments on annealed Phalaborwa baddeleyite were designed to test whether the recently developed chemical abrasion technique for U–Pb zircon geochronology can be applied to baddeleyite. The experiments generated complex results—individual digestion steps were both normally and reversely discordant suggesting that U and Pb were decoupled in the multi-step digestions—and indicate that the current form of multi-step chemical abrasion is not an effective method for reducing the impact of Pb-loss in baddeleyite. A separate set of experiments on the Gannakouriep baddeleyite focused on isolating the zircon and baddeleyite components in composite grains. Conventional single-step digestion experiments for this sample resulted in a discordant suite of analyses with significant scatter attributed to inter- and over-grown zircon and highlight the difficulty of obtaining precise and accurate ages from composite grains. To isolate the baddeleyite and zircon in these grains, a two-step HCl–HF chemical abrasion procedure for annealed grains was developed. This technique was successful at selectively dissolving the baddeleyite and zircon components. Secondary zircon inter- and over-growths of baddeleyite can occur in samples affected by low-temperature alteration to granulite facies metamorphism, and the new HCl–HF chemical abrasion procedure provides a method for resolving both the igneous and metamorphic history of these composite grains.
Viscous, Resistive Magnetorotational Modes

We carry out a comprehensive analysis of the behavior of the magnetorotational instability (MRI) in viscous, resistive plasmas. We find exact, nonlinear solutions of the nonideal magnetohydrodynamic (MHD) equations describing the local dynamics of an incompressible, differentially rotating background threaded by a vertical magnetic field when disturbances with wavenumbers perpendicular to the shear are considered. We provide a geometrical description of these viscous, resistive MRI modes and show how their physical structure is modified as a function of the Reynolds and magnetic Reynolds numbers. We demonstrate that when finite dissipative effects are considered, velocity and magnetic field disturbances are no longer orthogonal (as is the case in the ideal MHD limit) unless the magnetic Prandtl number is unity. We generalize previous results found in the ideal limit and show that a series of key properties of the mean Reynolds and Maxwell stresses also hold for the viscous, resistive MRI. In particular, we show that the Reynolds stress is always positive and the Maxwell stress is always negative. Therefore, even in the presence of viscosity and resistivity, the total mean angular momentum transport is always directed outward. We also find that, for any combination of the Reynolds and magnetic Reynolds numbers, magnetic disturbances dominate both the energetics and the transport of angular momentum and that the total mean energy density is an upper bound for the total mean stress responsible for angular momentum transport. The ratios between the Maxwell and Reynolds stresses and between magnetic and kinetic energy densities increase with decreasing Reynolds numbers for any magnetic Reynolds number; the lowest limit of both ratios is reached in the ideal MHD regime. The analytical results presented here provide new benchmarks for the various algorithms employed to solve the viscous, resistive MHD equations in the shearing box approximation.
Defining the mechanism(s) of protection by cytolytic CD8 T cells against a cryptic epitope derived from a retroviral alternative reading frame.

The biological significance of protective CD8 T-cell-mediated responses against non-traditional alternative reading frame epitopes remains relatively unknown. Cytolytic CD8 T cells (CTL) specific for a non-traditional cryptic MHC class I epitope, SYNTGRFPPL, are critically involved in the protection of mice during infection with the LP-BM5 murine retrovirus. The goal of this study was to determine the functional properties of the protective SYNTGRFPPL-specific CTL during LP-BM5 infection of susceptible BALB/c CD8−/− mice. Direct infection experiments and adoptive transfer of CD8 T cells derived from perforin (pfp)−/−, IFNγ−/−, FasL−/− and, as a positive control, wild-type BALB/c mice, were utilized to assess the effector mechanisms responsible for protection. Our results indicate that SYNTGRFPPL-specific effector CTL preferentially utilize perforin-mediated cytolysis to provide protection against LP-BM5-induced pathogenesis, whereas CTL production of IFNγ is not required. Our results also suggest a minimal contribution of FasL/Fas-mediated lysis during the effector response. Collectively, these results provide insight into effector mechanisms utilized by protective CTL directed against non-traditional cryptic epitopes during disease protection.
X-Ray Processing of ChaMPlane Fields: Methods and Initial Results for Selected Anti-Galactic Center Fields

We describe the X-ray analysis procedure of the ongoing Chandra Multiwavelength Plane (ChaMPlane) Survey and report the initial results from the analysis of 15 selected anti-Galactic center observations (90° < l < 270°). We describe the X-ray analysis procedures for ChaMPlane using custom-developed analysis tools appropriate for Galactic sources but also of general use: optimum photometry in crowded fields using advanced techniques for overlapping sources, rigorous astrometry and 95% error circles for combining X-ray images or matching to optical/IR images, and application of quantile analysis for spectral analysis of faint sources. We apply these techniques to 15 anti-Galactic center observations (of 14 distinct fields), in which we have detected 921 X-ray point sources. We present log N-log S distributions and quantile analysis to show that in the hard band (2-8 keV) active galactic nuclei dominate the sources. Complete analysis of all ChaMPlane anti-Galactic center fields will be given in a subsequent paper, followed by papers on sources in the Galactic center and bulge regions.
Models for X-Ray Emission from Isolated Pulsars

A model is proposed for the observed combination of power-law and thermal X-rays from rotationally powered pulsars. For gamma-ray pulsars with accelerators very many stellar radii above the neutron star surface, 100 MeV curvature gamma-rays from e(-) or e(+) flowing starward out of such accelerators are converted to e1 pairs on closed field lines all around the star. These pairs strongly affect X-ray emission from near the star in two ways. (1) The pairs are a source of synchrotron emission immediately following their creation in regions where B approx. 10(exp 10) G. This emission, in the photon energy range 0.1 keV less than E(sub X) less than 5 MeV, has a power-law spectrum with energy index 0.5 and X-ray luminosity that depends on the back-flow current, and is typically approx. 10(exp 33) ergs/ s. (2) The pairs ultimately a cyclotron resonance "blanket" surrounding the star except for two holes along the open field line bundles which pass through it. In such a blanket the gravitational pull on e(+,-) pairs toward the star is balanced by the hugely amplified push of outflowing surface emitted X-rays wherever cyclotron resonance occurs. Because of it the neutron star is surrounded by a leaky "hohlraum" of hot blackbody radiation with two small holes, which prevents direct X-ray observation of a heated polar cap of a gamma-ray pulsar. Weakly spin modulated radiation from the blanket together with more strongly spin-modulated radiation from the holes through it would then dominate observed low energy (0.1-10 keV) emission. For non-y-ray pulsars, in which no such accelerators with their accompanying extreme relativistic back-flow toward the star are expected, optically thick e1 resonance blankets should not form (except in special cases very close to the open field line bundle). From such pulsars blackbody radiation from both the warm stellar surface and the heated polar caps should be directly observable. In these pulsars, details of the surface magnetic field evolution, especially of polar cap areas, become relevant to observations. The models are compared to X-ray data from Geminga, PSR 1055-52, PSR 0656+14, PSR 1929+10, and PSR 0950+08.
Expansion Rates at RHIC

A detailed description of the temporal evolution of the thermodynamic fields in heavy ion collisions is presented within a hydrodynamic framework. Particular attention is devoted to the evolution of the collective flow fields and their space-time gradients.
Persistence of tumor-infiltrating CD8 T cells is tumor-dependent but antigen-independent

How tumor-infiltrating lymphocytes (TILs) that are tumor-specific but functionally tolerant persist in the antigen-expressing tumor tissue is largely unknown. We have previously developed a modified TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) model where prostate cancer cells express the T-cell epitope SIYRYYGL (SIY) recognized by CD8 T cells expressing the 2C T-cell receptor (TCR) (referred to as TRP-SIY mice). In TRP-SIY mice, activated 2C T cells rapidly become tolerant following infiltration into the prostate tumor. In this study, we show that tolerant 2C T cells persist in the prostate tumor of TRP-SIY mice by proliferating slowly in a tumor-dependent, but antigen-, interleukin (IL)-7- and IL-15-independent manner. We also show that disappearance of 2C T cells from the lymphoid organs of TRP-SIY mice are due to antigen-induced T-cell contraction rather than altered trafficking or generalized T-cell depletion in the mice. Finally, we show that clonal T cells unreactive to SIY are equally capable of persisting in the prostate tumor. These findings suggest that while functional tolerance of TILs is induced by antigen, persistence of tolerant TILs in the tumor tissue is mediated by a novel mechanism: slow proliferation independent of antigen and homeostatic cytokines. These results also allow CD8 T-cell survival in the tumor environment to be compared with T-cell survival in chronic infection.