cssi/SciSciGPT-SciSciNet huggingface dataset:
Sieve, Incubator, Temple, Hub: Empirical and Theoretical Advances in the Sociology of Higher Education

Higher education lacks an intellectually coherent sociology; varied research on colleges and universities is dispersed widely throughout the discipline. This review initiates a critical integration of this scholarship. We argue that sociologists have conceived of higher education systems as sieves for sorting and stratifying populations, incubators for the development of competent social actors, temples for the legitimation of official knowledge, and hubs connecting multiple institutional domains. Bringing these lines of scholarship together facilitates new theoretical insights and research questions.
Tensor Regression with Applications in Neuroimaging Data Analysis

Classical regression methods treat covariates as a vector and estimate a corresponding vector of regression coefficients. Modern applications in medical imaging generate covariates of more complex form such as multidimensional arrays (tensors). Traditional statistical and computational methods are proving insufficient for analysis of these high-throughput data due to their ultrahigh dimensionality as well as complex structure. In this article, we propose a new family of tensor regression models that efficiently exploit the special structure of tensor covariates. Under this framework, ultrahigh dimensionality is reduced to a manageable level, resulting in efficient estimation and prediction. A fast and highly scalable estimation algorithm is proposed for maximum likelihood estimation and its associated asymptotic properties are studied. Effectiveness of the new methods is demonstrated on both synthetic and real MRI imaging data. Supplementary materials for this article are available online.
Low complexity soft-input soft-output block decision feedback equalization

A low complexity soft-input soft-output (SISO) block decision feedback equalizer (BDFE) is presented for turbo equalization. The proposed method employs a sub-optimum sequence-based detection, where the soft-output of the equalizer is calculated by evaluating an approximation of the sequence-based a posteriori probability (APP) of the data symbol. The sequence-based APP approximation is enabled by the adoption of both soft a priori information and soft decision feedback, and it leads to better performance and faster convergence compared to symbol-based detection methods as used by most other low complexity equalizers. The performance and convergence property of the proposed algorithm is analyzed by using extrinsic information transfer (EXIT) chart. Both analytical and simulation results show that the new equalizer can achieve a performance similar to that of trellis-based equalization algorithms, with a complexity similar to linear SISO minimum mean square error equalizers.
Chiral Silanediols in Anion‐Binding Catalysis

A perfect pair: Silanediols are effective catalysts for the addition of silyl ketene acetals to N-acylisoquinolinium ions. Importantly, this is the first example of a silanediol plausibly participating in anion-binding catalysis, a relatively new direction in the field of hydrogen-bond-donor catalysis. The chiral, enantiopure C2 -symmetric silanediol 1 catalyzes enantioselective transformations.
Heavy ion physics at the LHC with the ATLAS detector

The ATLAS detector at CERN will provide a high-resolution longitudinally segmented calorimeter and precision tracking for the upcoming study of heavy ion collisions at the LHC ( GeV). The calorimeter covers |η| < 5 with both electromagnetic and hadronic sections, while the inner detector spectrometer covers |η| < 2.5. ATLAS will study a full range of observables necessary to characterize the hot and dense matter formed at the LHC. Global measurements (particle multiplicities, collective flow) will provide access into its thermodynamic and hydrodynamic properties. Measuring complete jets out to 100's of GeV will allow detailed studies of energy loss and its effect on jets. Quarkonia will provide a handle on deconfinement mechanisms. ATLAS will also study the structure of the nucleon and nucleus using forward physics probes and ultraperipheral collisions, both enabled by segmented zero degree calorimeters.
Intramolecular anodic olefin coupling reactions: the use of allylsilanes

Abstract The use of allylsilanes as directing groups in the intramolecular electrochemical coupling of electron rich olefins has been examined. The allylsilanes were shown to provide an effective means for controlling product selectivity, and led to the formation of five- and six-membered ring products in 59–84% isolated yields.
Collision Helps - Algebraic Collision Recovery for Wireless Erasure Networks

Current medium access control mechanisms are based on collision avoidance and collided packets are discarded. The recent work on ZigZag decoding departs from this approach by recovering the original packets from multiple collisions. In this paper, we present an algebraic representation of collisions which allows us to view each collision as a linear combination of the original packets. The transmitted, colliding packets may themselves be a coded version of the original packets. We propose a new acknowledgment (ACK) mechanism for collisions based on the idea that if a set of packets collide, the receiver can afford to ACK exactly one of them and still decode all the packets eventually. We analytically compare delay performance of such collision recovery schemes with other collision avoidance approaches in the context of a single hop wireless erasure network. From the delay perspective, our scheme, without any coordination, outperforms not only ALOHA-type random access mechanisms, but also centralized scheduling.
A High-Performance Position Control

The position control described has been designed to achieve an accuracy of plus or minus 1 part in 4000. The control is part of the positioning mechanism for the read-write heads in a random-access magnetic-drum memory; it can position the heads to any 1 of 200 track locations, on command, in less than 100 milliseconds.
What determines the profitability of foreign direct investment? A subsidiary‐level analysis of Japanese multinationals

This article identifies key factors that determine the profitability of Japanese firms abroad by using panel-data regression models on new, large-scale, subsidiary-level data over the 1990–1996 period. The results show that the determinants of subsidiary profits differ across host regions, suggesting that the economic and institutional factors specific to host regions influence significantly the profit performances of overseas subsidiaries. While the size effect on the subsidiary profitability is present in all the regions, other effects, such as experience, local supplier networks, local sales and macroeconomic conditions affect the performance of subsidiaries in a different manner by region. Copyright © 2008 John Wiley & Sons, Ltd.
Heating distribution of multipolar radiofrequency ablation catheters

Radiofrequency (RF) catheter ablation therapy has been recognized as an effective treatment for a variety of cardiac arrhythmias. In fact, for several arrhythmias, including Wolf-Parkinson-White Syndrome, this technique is greater than 95% curative. However, when applied for the treatment of ventricular tachycardia or atrial fibrillation, RF catheter ablation has been far less successful. It is believed that the small lesions produced by current RF catheters are not sufficient to reliably treat these disorders. This study presents experimental measurements of heating patterns of commercially available multipolar RF ablation catheters. Three different electrode configurations were investigated. Results revealed significant differences in the catheter specific absorption rate pattern across the different configurations. Further in vitro and in vivo studies are underway to investigate these effects on actual lesion formation.
Sums of entire functions having only real zeros

We show that certain sums of products of Hermite-Biehler entire functions have only real zeros, extending results of Cardon. As applications of this theorem, we construct sums of exponential functions having only real zeros, we construct polynomials having zeros only on the unit circle, and we obtain the three-term recurrence relation for an arbitrary family of real or- thogonal polynomials. We discuss a similarity of this result with the Lee-Yang circle theorem from statistical mechanics. Also, we state several open prob- lems.
Face recognition through pose estimation and fringe-adjusted joint transform correlation

We describe a simple pose estimation-based optoelectronic system for the recognition of facial images. The pose estimation de- scribed is a simple digital algorithm that is used to replace the composite image generation techniques while maintaining a low interclass cross- correlation. The optoelectronic fringe-adjusted joint transform correlator (FJTC) is then used to provide correlation. A description of the optoelec- tronic system and the entire process is presented. In addition, simulation results and comparison to synthetic discriminant function (SDF)-based recognition are provided to prove the effectiveness of the proposed sys- tem. © 2003 Society of Photo-Optical Instrumentation Engineers.
Medication Treatment of Different Types of Alcoholism

Alcoholism remains a serious cause of morbidity and mortality despite progress through neurobiological research in identifying new pharmacological strategies for its treatment. Drugs that affect neural pathways that modulate the activity of the cortico-mesolimbic dopamine system have been shown to alter drinking behavior, presumably because this dopaminergic system is closely associated with rewarding behavior. Ondansetron, naltrexone, topiramate, and baclofen are examples. Subtyping alcoholism in adults into an early-onset type, with chronic symptoms and a strong biological predisposition to the disease, and a late-onset type, typically brought on by psychosocial triggers and associated with mood symptoms, may help in the selection of optimal therapy. Emerging adults with binge drinking patterns also might be aided by selective treatments. Although preliminary work on the pharmacogenetics of alcoholism and its treatment has been promising, the assignment to treatment still depends on clinical assessment. Brief behavioral interventions that encourage the patient to set goals for a reduction in heavy drinking or abstinence also are part of optimal therapy.
New algorithms for digital convolution

It is shown how the Chinese Remainder Theorem (CRT) can be used to convert a one-dimensional cyclic convolution to a multi-dimensional convolution which is cyclic in all dimensions. Then, special algorithms are developed which, compute the relatively short convolutions in each of the dimensions. The original suggestion for this procedure was made in order to extend the lengths of the convolutions which one can compute with number-theoretic transforms. However, it is shown that the method can be more efficient, for some data sequence lengths, than the fast Fourier transform (FFT) algorithm. Some of the short convolutions are computed by methods in an earlier paper by Agarwal and Burrus. Recent work of Winograd, consisting of theorems giving the minimum possible numbers of multiplications and methods for achieving them, are applied to these short convolutions.
Implementation Theory with Incomplete Information

This paper surveys implementation theory when players have incomplete or asymmetric information, especially in economic environments. After the basic problem is introduced, the theory of implementation is summarized. Some coalitional considerations for implementation problems are discussed. For economies with asymmetric information, cooperative games based on incentive compatibility constraints or Bayesian incentive compatible mechanisms are derived and examined.
A MODIFIED FRW METRIC TO EXPLAIN THE COSMOLOGICAL CONSTANT

One of the most outstanding problems of the standard model of cosmology today is the problem of cosmological constant/dark energy. It corresponds to about 73% of the energy content of the universe gone missing. I hereby postulate a modified FRW metric for our universe, which animates a universe spinning very slowly with an angular frequency that is equal to the Hubble's constant. It is shown by a simple argument that in such a universe there will be an overlooked rotational energy whose average value is identically equal to the matter-energy content of this universe as observed by a coordinate observer. The corresponding Friedmann equation is derived, whereby the overlooked rotational energy naturally becomes the cosmological constant/dark energy term without artificially/mysteriously adding any such term, as is commonly done. The proposed model also produces Hubble's law naturally.
The performance of noncoherent orthogonal M-FSK in the presence of timing and frequency errors

Practical M-FSK systems experience a combination of time and frequency offsets (errors). The paper assesses the deleterious effect of these offsets, first individually and then combined, on the average bit error probability performance of the system. Exact expressions for these various error probability performances are derived and evaluated numerically for system parameters of interest. Both continuous and discontinuous phase M-FSK cases are considered when timing error is present, the latter being much less robust to this type of offset.
Use of InCl3 as a Cocatalyst and a Cl2Pd(DPEphos)−P(2-Furyl)3 Catalyst System for One-Pot Hydrometalation−Cross-Coupling and Carbometalation−Cross-Coupling Tandem Processes

One-pot conversion of alkynes to regio- and stereodefined alkenylmetals containing Al and Zr via hydrometalation or carbometalation followed by their Pd-catalyzed cross-coupling with (E)-ICHCHBr or (E)-ICHCHCl proceeds cleanly and selectively to give the corresponding 1-halo-1,3-dienes in excellent yields using a catalyst system consisting of Cl2Pd(DPEphos), DIBAL-H, and TFP (catalyst A) with InCl3 as a cocatalyst.
The European agricultural trade policies and poverty

This paper tries to estimate the effects of reforming European agricultural trade policy on poverty in Europe and in the developing world. After setting out a conceptual framework linking trade and poverty, it describes a detailed computable general equilibrium modelling exercise showing the effects on poverty of a possible agreement in the Doha Round of the World Trade Organization. It then conducts a global simulation on European agricultural liberalisation and by comparing it with the Doha simulations infers the poverty effects in the developing world. These are benign but not very large. This does not change the case for reform, however; the Common Agricultural Policy harms trade relations with developing countries and causes poverty in Europe.
SybilControl: practical sybil defense with computational puzzles

Many distributed systems are subject to the Sybil attack, where an adversary subverts system operation by emulating the behavior of multiple distinct nodes. Most recent works addressing this problem leverage social networks to establish trust relationships between users. However, social networks are not appropriate in all systems. They can be subverted by social engineering techniques, require nodes to maintain and be aware of social network information, and may require overly optimistic assumptions about the fast-mixing nature of social links.This paper explores an alternate approach. We present SybilControl, a novel decentralized scheme for controlling the extent of Sybil attacks. It is an admission and retainment control scheme for nodes in a distributed system that requires them to periodically solve computational puzzles. SybilControl consists of a distributed protocol to allow nodes to collectively verify the computational work of other nodes, and mechanisms to prevent the malicious influence of misbehaving nodes that do not perform the computational work. We investigate the practical issues involved with deploying SybilControl into existing DHTs, particularly with handling churn. SybilControl is shown to provide strict bounds on the size of Sybil attacks, given adversaries with finite resources. We also show through simulations that the performance overhead of enabling SybilControl is manageable using commonplace DHT churn-handling techniques. This provides strong evidence that SybilControl can be practically deployed.
Ni(II) Tol-BINAP-catalyzed enantioselective orthoester alkylations of N-acylthiazolidinethiones.

The development of a Ni(II) (S)-Tol-BINAP-catalyzed enantioselective alkylation of N-acylthiazolidinethiones with trimethyl orthoformate is described. The reaction is general with respect to the thiazolidinethione, providing the desired adducts in good to excellent yield and with high levels of enantioselectivity (11 examples, 51−92% yield, 90−99% ee). The products are readily converted into a variety of synthetically useful derivatives in a straightforward manner.
Quantum K-theory on flag manifolds, finite-difference Toda lattices and quantum groups

Let (x : y) be homogeneous coordinates on CP . A degree d holomorphic map CP 1 → CP is uniquely determined, up to a constant scalar factor, by N + 1 relatively prime degree d binary forms (f0(x : y) : ... : fN(x : y)). Omitting the condition that the forms are relatively prime we compactify the space of degree d holomorphic maps CP 1 → CP to a complex projective space of dimension (N +1)(d+1)− 1. We denote this compactification of the space of maps by CP d . This construction defines the compactification Πd = Π r i=1CP ni−1 di of the space of degree d = (d1, ..., dr) maps from CP 1 to Π. Composing degree d holomorphic maps from CP 1 to the flag manifold X with the Plucker embedding, we embed the space of such maps into Πd. The closure QMd of this space in Πd is often referred to as the Drinfeld’s compactification of the space of degree d maps from CP 1 to X and will be called the space of quasimaps (following [14]). It is a (generally speaking — singular) irreducible projective variety of complex dimension dimX + 2d1 + ...+ 2dr. The flag manifold is a homogeneous space of the group SLr+1(C) and of its maximal compact subgroup SUr+1. The action of these groups on X lifts naturally to the spaces Π, Πd, and QMd. In addition to this action the spaces Πd and the subspaces QMd carry the circle action induced by the rotation of CP 1 defined by (x : y) 7→ (x : ey). Thus the product group G = S × SUr+1 and its complex version GC = C ∗ × SLr+1(C) act on the quasimap spaces. We will see later that QMd have G-equivariant desingularizations QMd.
Unitarity and Holography in Gravitational Physics

Because the gravitational Hamiltonian is a pure boundary term on shell, asymptotic gravitational fields store information in a manner not possible in local field theories. This fact has consequences for both perturbative and nonperturbative quantum gravity. In perturbation theory about an asymptotically flat collapsing black hole, the algebra generated by asymptotic fields on future null infinity within any neighborhood of spacelike infinity contains a complete set of observables. Assuming that the same algebra remains complete at the nonperturbative quantum level, we argue that either (1) the $S$ matrix is unitary or (2) the dynamics in the region near timelike, null, and spacelike infinity is not described by perturbative quantum gravity about flat space. We also consider perturbation theory about a collapsing asymptotically anti-de Sitter (AdS) black hole, where we show that the algebra of boundary observables within any neighborhood of any boundary Cauchy surface is similarly complete. Whether or not this algebra continues to be complete nonperturbatively, the assumption that the Hamiltonian remains a boundary term implies that information available at the AdS boundary at any one time ${t}_{1}$ remains present at this boundary at any other time ${t}_{2}$.
Huntington's Disease: Can Mice Lead the Way to Treatment?

Mouse models for Huntington's Disease (HD) and HD patients demonstrate motor and behavioral dysfunctions, such as progressive loss of coordination and memory, and share similar transcriptional profiles and striatal neuron atrophy. Clear differences between the mouse and human diseases include almost complete striatal degeneration and rarity of intranuclear inclusions in HD, and the fact that mice expressing full-length mutant huntingtin do not demonstrate a shortened life span characteritstic of HD. While no clinical interventions tested in mouse models to date have delayed disease progression, the mouse models provide an invaluable tool for both investigating the underlying pathogenic processes and developing new effective therapies. Inherent differences between humans and mice must be considered in the search for efficacious treatments for HD, but the striking similarities between human HD and mouse models support the view that these models are a biologically relevant system to support the identification and testing of potential clinical therapies.
Structural subband decomposition: a new concept in digital signal processing

Summary form only given, as follows. Polyphase decomposition of a sequence was advanced to develop computationally efficient interpolators and decimators, and has also been used to design computationally efficient quadrature-mirror filter banks. The polyphase decomposition represents a sequence into a set of sub-sequences, called polyphase components. However, the polyphase components do not exhibit any spectral separation. In this presentation, we first review the concept of structural subband decomposition, generalization of the polyphase decomposition, which decomposes a sequence into a set of sub-sequences with some spectral separation that can be exploited advantageously in many digital signal processing applications. We then outline some of the applications of the structural subband decomposition, such as efficient design and implementation of FIR digital filters, development of computationally efficient decimators and interpolators, subband adaptive filtering, and fast computation of discrete transforms.
Biosensor Systems in Standard CMOS Processes: Fact or Fiction?

In this paper, we discuss the advantages and limitations of using standard complementary metal-oxide-semiconductor (CMOS) fabrication processes for the design of integrated affinity-based biosensor systems. In particular, we examine the compatibility of CMOS with various assaying techniques, detection modalities, and the possibility of fabricating their transducer structures on-chip.
A Comparison of Copper Abundances in Globular Cluster and Halo Field Giant Stars

We derive [Cu/Fe] for 117 giant stars in 10 globular clusters (M3, M4, M5, M10, M13, M15, M71, NGC 7006, NCG 288, and NGC 362) and find that globular cluster Cu abundances appear to follow [Cu/Fe] trends found in the field. This result is interesting in light of recent work, which indicates that the globular cluster ω Centauri shows no trend in [Cu/Fe] with [Fe/H] over the abundance range -2.0<[Fe/H]<-0.8. Of particular interest are the two clusters M4 and M5. While at a similar metallicity ([Fe/H]~-1.2), they differ greatly in some elemental abundances: M4 is largely overabundant in Si, Ba, and La compared with M5. We find that it is also overabundant in Cu with respect to M5, although this overabundance is in accord with [Cu/Fe] ratios found in the field. (Less)
Catalytic cyclopropanation with transition metal salts of soluble polyethylene carboxylates

Abstract Syntheses of Rh(II) carboxylate salts of terminally funcfionalized polyethylene carboxylic acids arc described. These polymer-bound transition metals are homogeneous catalysts for cyclopropanation of alkenes at 100°C and have activities and selectivities like transition metal acetates but are quantitatively recoverable at 25°C.
Predicting cancer drug mechanisms of action using molecular network signatures

Molecular signatures are a powerful approach to characterize novel small molecules and derivatized small molecule libraries. While new experimental techniques are being developed in diverse model systems, informatics approaches lag behind these exciting advances. We propose an analysis pipeline for signature based drug annotation. We develop an integrated strategy, utilizing supervised and unsupervised learning methodologies that are bridged by network based statistics. Using this approach we can: 1, predict new examples of drug mechanisms that we trained our model upon; 2, identify “New” mechanisms of action that do not belong to drug categories that our model was trained upon; and 3, update our training sets with these “New” mechanisms and accurately predict entirely distinct examples from these new categories. Thus, not only does our strategy provide statistical generalization but it also offers biological generalization. Additionally, we show that our approach is applicable to diverse types of data, and that distinct biological mechanisms characterize its resolution of categories across different data types. As particular examples, we find that our predictive resolution of drug mechanisms from mRNA expression studies relies upon the analog measurement of a cell stress-related transcriptional rheostat along with a transcriptional representation of cell cycle state; whereas, in contrast, drug mechanism resolution from functional RNAi studies rely upon more dichotomous (e.g., either enhances or inhibits) association with cell death states. We believe that our approach can facilitate molecular signature-based drug mechanism understanding from different technology platforms and across diverse biological phenomena.
An Experimental Test of an Optimal Growth Model

This paper describes the design and behavior of an experimental economy with the structure of the Ramsey-Cass-Koopmans model of optimal growth. The experiment includes three different implementations of the model: a decentralized implementation with multiple agents and a market for capital, a treatment where individual subjects are placed in the role of social planners, and a treatment where the social planner consists of five agents making a joint decision. The findings highlight the role of market institutions in facilitating convergence to the optimal steady state. (JEL C91, C92, O40)
Multi-Placement Structures for Fast and Optimized Placement in Analog Circuit Synthesis

The paper presents the novel idea of multi-placement structures, for a fast and optimized placement instantiation in analog circuit synthesis. These structures need to be generated only once for a specific circuit topology. When used in synthesis, these pre-generated structures instantiate various layout floorplans for the various sizes and parameters of a circuit. Unlike procedural layout generators, they enable fast placement of circuits while keeping the quality of the placements at a high level during the synthesis process. The fast placement is a result of high speed instantiation resulting from the efficiency of the multi-placement structure. The good quality of placements derives from the extensive and intelligent search process that is used to build the multi-placement structure. The target benchmarks of these structures are analog circuits in the vicinity of 25 modules. An algorithm for the generation of such multi-placement structures is presented. Experimental results show placement execution times with an average of a few milliseconds making them usable during layout-aware synthesis for optimized placements.
Executive Power in American Institutional Development

In striking contrast to the legislatures in most modern democracies, Congress retains an important place in American politics and policy making. Especially in recent years, this has led many observers to question the importance of the presidency and bureaucracy to the real work of American governance and the extent to which political actors in the executive branch generally exercise power. This narrative of congressional dominance has been particularly bolstered by recent scholarly interest in principal-agent models of interbranch relations. The assumption of congressional centrality, however, obscures many important features of American politics. Over the course of American history, institutional development in particular has often been driven by either autonomous executive action or conflicts between Congress and the executive. We develop an approach for assessing executive power in institutional politics and illustrate the logic of executive influence with three cases: the rise of federal food-and-drug and forestry regulation, and the growth of the federal farm extension service in the early twentieth century; the rise of the national security state in the mid-twentieth century; and the evolution of budgeting and spending practices over the course of the twentieth century.
Spatial evolutionary games with small selection coefficients

Here we will use results of Cox, Durrett, and Perkins [56] for voter model perturbations to study spatial evolutionary games on Z d , d 3 when the interaction kernel is finite range, symmetric, and has covariance matrix 2 I. The games we consider have payoff matrices of the form 1 + wG where 1 is matrix of all 1’s and w is small and positive. Since our population size N = 1, we call our selection small rather than weak which usually means w = O(1/N).
The Impact of Pulsed RFI on the Coded BER Performance of the Nonlinear Satellite Communication Channel

The coded bit error rate (BER) performance of a satellite communications system, wherein the satellite repeater contains an arbitrary nonlinearity and the system operates in the presence of pulsed radio frequency interference (RFI), is examined. A major result is an analytic method for determining soft decision statistics of the receiver demodulator output in which pulsed RFI effects are accounted for. It is further demonstrated how this result can be analytically applied to the approximate determination of the BER at the output of the Viterbi decoder when convolutional coding is employed. Computed results specialize the nonlinearity to either a hard limiter or clipper, in conjunction with an arbitrarily specified AM/PM characteristic. Performance curves examine BER sensitivity to RFI duty cycle, form of RFI (CW or noise), and various coding/decoding conditions.
Effect of adaptive cruise control systems on mixed traffic flow near an on-ramp

Abstract Mixed traffic flow consisting of vehicles equipped with adaptive cruise control (ACC) and manually driven vehicles is analyzed using car-following simulations. Simulations of merging from an on-ramp onto a freeway reported in the literature have not thus far demonstrated a substantial positive impact of ACC. In this paper cooperative merging for ACC vehicles is proposed to improve throughput and increase distance traveled in a fixed time. In such a system an ACC vehicle senses not only the preceding vehicle in the same lane but also the vehicle immediately in front in the other lane. Prior to reaching the merge region, the ACC vehicle adjusts its velocity to ensure that a safe gap for merging is obtained. If on-ramp demand is moderate, cooperative merging produces significant improvement in throughput (20%) and increases up to 3.6 km in distance traveled in 600 s for 50% ACC mixed flow relative to the flow of all-manual vehicles. For large demand, it is shown that autonomous merging with cooperation in the flow of all ACC vehicles leads to throughput limited only by the downstream capacity, which is determined by speed limit and headway time.
Youth Violence Prevention Comes of Age: Research, Training and Future Directions

Youth violence is recognized as a major public health problem in the United States and the world. Over the past ten years, progress has been made in documenting the factors that contribute to violent behavior. Emerging research is deepening our understanding of the individual and societal influences that contribute to and protect against youth violence. However, much work still remains to be done in this field, both in examining potential causes and in designing effective intervention strategies. This chapter highlights specific dimensions of youth violence prevention selected by the authors because these dimensions are the focus of public attention, are emerging as critical issues in the study of youth violence, or have a unique place in the current political and social context. We focus on the developmental pathways to violence, factors that mediate and moderate youth violence, the role of culture and media in youth violence, school-based violence such as school shootings and bullying, and the training of health care professionals.
First-principles theory of magnetically induced ferroelectricity in TbMnO3

We study the polarization induced via spin-orbit interaction by a magnetic cycloidal order in orthorhombic TbMnO3 using first-principle methods. The case of magnetic spiral lying in the b-c plane is analyzed, in which the pure electronic contribution to the polarization is shown to be small. We focus our attention on the lattice-mediated contribution, and study it’s dependence on the Coulomb interaction parameter U in the LDA+U method and on the wave-vector of the spin spiral. The role of the spin-orbit interaction on different sites is also analyzed.
Asymptotically optimal downlink scheduling over Markovian fading channels

We consider the scheduling problem in downlink wireless networks with heterogeneous, Markov-modulated, ON/OFF channels. It is well-known that the performance of scheduling over fading channels heavily depends on the accuracy of the available Channel State Information (CSI), which is costly to acquire. Thus, we consider the CSI acquisition via a practical ARQ-based feedback mechanism whereby channel states are revealed at the end of only scheduled users' transmissions. In the assumed presence of temporally-correlated channel evolutions, the desired scheduler must optimally balance the exploitation-exploration trade-off, whereby it schedules transmissions both to exploit those channels with up-to-date CSI and to explore the current state of those with outdated CSI. In earlier works, Whittle's Index Policy had been suggested as a low-complexity and high-performance solution to this problem. However, analyzing its performance in the typical scenario of statistically heterogeneous channel state processes has remained elusive and challenging, mainly because of the highly-coupled and complex dynamics it possesses. In this work, we overcome these difficulties to rigorously establish the asymptotic optimality properties of Whittle's Index Policy in the limiting regime of many users. More specifically: (1) we prove the local optimality of Whittle's Index Policy, provided that the initial state of the system is within a certain neighborhood of a carefully selected state; (2) we then establish the global optimality of Whittle's Index Policy under a recurrence assumption that is verified numerically for the problem at hand. These results establish, for the first time to the best of our knowledge, that Whittle's Index Policy possesses analytically provable optimality characteristics for scheduling over heterogeneous and temporally-correlated channels.
Theoretical modeling of star-forming galaxies. I. Emission-line diagnostic grids for local and low-metallicity galaxies

We use the newest generation of the Starburst99/Mappings code to generate an extensive suite of models to facilitate detailed studies of star-forming galaxies and their interstellar medium properties, particularly at low metallicities. The new models used include a rigorous treatment of metal opacities in the population synthesis modeling and more detailed dust physics in the photoionization code. These models span a wide range of physical parameters including metallicity, ionization parameter, and the adoption of both an instantaneous burst and continuous star formation history (SFH). We examine the agreement between our models and local (z < 0.1) star-forming galaxy populations from several large data sets, including the Sloan Digital Sky Survey, the Nearby Field Galaxy Survey, and samples of blue compact galaxies and metal-poor galaxies. We find that models adopting a continuous SFH reproduce the metallicity-sensitive line ratios observed in the local population of star-forming galaxies, including the low-metallicity sample. However, we find that the current codes generate an insufficiently hard ionizing radiation field, leading to deficiencies in the [S II] fluxes produced by the models. We consider the advantages and shortcomings of this suite of models, and discuss future work and improvements that can be applied to the modeling of star-forming galaxies.
Energetics Of Peptide (pHLIP) Binding To And Folding Across A Lipid Bilayer Membrane

The pHLIP peptide (pH Low Insertion Peptide) serves as a model system for peptide insertion and folding across a lipid bilayer. It has three general states: (I) soluble in water or (II) bound to the surface of a lipid bilayer as an unstructured monomer, and (III) inserted across the bilayer as a monomeric α-helix. We used fluorescence spectroscopy and isothermal titration calorimetry to study the interactions of pHLIP with a POPC lipid bilayer and to calculate the transition energies between states. We found that the Gibbs Free Energy of binding to a POPC surface at low pHLIP concentration (state I - state II transition) at 37°C is about -7 kcal/mol near neutral pH and that the free energy of insertion and folding across a lipid bilayer at low pH (state II - state III transition) is nearly -2 kcal/mol. We plan to discuss a number of related thermodynamic parameters from our measurements. Besides its fundamental interest as a model system for the study of membrane protein folding, pHLIP has utility as an agent to target diseased tissues and translocate molecules through the membrane into the cytoplasm of cells in environments with elevated levels of extracellular acidity, as in cancer and inflammation. The results give the amount of energy that might be used to move cargo molecules across a membrane.
Linear Feedback Control Using Quasi Velocities

A novel approach for designing feedback controllers for natural mechanical systems using quasi velocities is presented. The approach is relevant to the stabilization and regulation of finite-dimensional multibody systems. In particular the globally asymptotically stable linear feedback of Rodrigues parameters and angular velocity is taken from spacecraft attitude control and applied to a broader class of problems. This controller is shown to have good performance due to the sensitivity of the rotational kinematics to small motions near the reference configuration. Additionally, the concept is extended to systems with more than three degrees of freedom by generalizing the functional form of the three-dimensional rotational kinematics. This defines a new set of quasi velocities that allow globally asymptotically stable linear feedback for any number of degrees of freedom. Anexample shows that the use of these variables in controller design can lead to improved performance.
Dynamics of an Erupting Arched Magnetic Flux Rope in a Laboratory Plasma Experiment

A laboratory plasma experiment has been built to study the eruption of arched magnetic flux ropes (AMFRs) in the presence of a large magnetized plasma. This experiment simulates the eruption of solar AMFRs in two essential steps: i) it produces an AMFR (n=6.0×1012 cm−3, \(T_{\rm e} = 14~\mathrm{eV}\), B≈1 kilo-gauss, L=0.51 m) with a persistent appearance that lasts several Alfven transit times using a lanthanum hexaboride (LaB6) plasma source, and ii) it generates controlled plasma flows from the footpoints of the AMFR using laser beams. An additional LaB6 plasma source generates a large magnetized plasma in the background. The laser-generated flows trigger the eruption by injecting dense plasma and magnetic flux into the AMFR. The experiment is highly reproducible and runs continuously with a 0.5 Hz repetition rate; hence, several thousand identical loop eruptions are routinely generated and their spatio-temporal evolution is recorded in three-dimensions using computer-controlled movable probes. Measurements demonstrate striking similarities between the erupting laboratory and solar arched magnetic flux ropes.
Watching corn grow: a hedonic study of the Iowa landscape.

Landscape amenities can be scarce in places with large areas of open space. Intensely farmed areas with high levels of monocropping and livestock production are akin to developed open space areas and do not provide many services in terms of landscape amenities. Open space in the form of farmland is plentiful, but parks and their services are in short supply. This issue is of particular importance for public policy because it is closely linked to the impact of externalities caused by agricultural activities and to the indirect effects of land use dynamics. This study looks at the impact of landscape amenities on rural residential property values in five counties in North Central Iowa using a hedonic pricing model based on geographic information systems. The effect of cropland, pasture, forest, and developed land as land uses surrounding the property is considered, as well as the impact of proximity to recreational areas. The study also includes the effect of other disamenities, such as livestock facilities and quarries, which can be considered part of the developed open space and are a common feature of the Iowa landscape.
Conflicts of Interest and Market Illiquidity in Bankruptcy Auctions: Theory and Tests

I develop and estimate a model of cash auction bankruptcy using data on 205 Swedish firms. The results challenge arguments that cash auctions, as compared to reorganizations, are immune to conflicts of interest between claimholders but lead to inefficient liquidations. I show that a sale of the assets back to incumbent management is a common bankruptcy outcome. Sale-backs are more likely when they favor the bank at the expense of other creditors. On the other hand, inefficient liquidations are frequently avoided through sale-backs when markets are illiquid, that is, when industry indebtedness is high and the firm has few nonspecific assets. THE PROBLEM OF DESIGNING an efficient bankruptcy law has received considerable attention in the last decade. Much of the debate has centered around the optimality of two different stylized bankruptcy procedures: cash auctions, such as the U.S. Chapter 7 code, and structured bargaining, represented by the U.S. Chapter 11 reorganization code. Recently, several European countries (including France, Germany, and Great Britain) have changed their bankruptcy regulation by introducing reorganization procedures similar to Chapter 11. At the same time, the Chapter 11 code has been criticized by academics, including Baird (1986), emphasizing that the bargaining procedure frequently results in long and wasteful negotiations. These critics argue that Chapter 11 should instead be replaced with a mandatory auction procedure. Other researchers, such as Aghion, Hart, and Moore (1992) and Shleifer and Vishny (1992), have pointed out that a cash auction is likely to suffer from considerable inefficiencies arising from transaction costs and market illiquidity. The nature and costs of the Chapter 11 procedure are
The geometric interpretation of Fröberg–Iarrobino conjectures on infinitesimal neighbourhoods of points in projective space

Abstract The study of infinitesimal deformations of a variety embedded in projective space requires, at ground level, that of deformation of a collection of points, as specified by a zero-dimensional scheme. Further, basic problems in infinitesimal interpolation correspond directly to the analysis of such schemes. An optimal Hilbert function of a collection of infinitesimal neighbourhoods of points in projective space is suggested by algebraic conjectures of R. Froberg and A. Iarrobino. We discuss these conjectures from a geometric point of view. They give, for each such collection, a function (based on dimension, number of points, and order of each neighbourhood) which should serve as an upper bound to its Hilbert function (Weak Conjecture). The Strong Conjecture predicts when the upper bound is sharp, in the case of equal order throughout. In general we refer to the equality of the Hilbert function of a collection of infinitesimal neighbourhoods with that of the corresponding conjectural function as the Strong Hypothesis. We interpret these conjectures and hypotheses as accounting for the infinitesimal neighbourhoods of projective subspaces naturally occurring in the base locus of a linear system with prescribed singularities at fixed points. We develop techniques and insight toward the conjectures' verification and refinement. The main result gives an upper bound on the Hilbert function of a collection of infinitesimal neighbourhoods in P n based on Hilbert functions of certain such subschemes of P n − 1 . Further, equality occurs exactly when the scheme has only the expected linear obstructions to the linear system at hand. It follows that an infinitesimal neighbourhood scheme obeys the Weak Conjecture provided that the schemes identified in codimension one satisfy the Strong Hypothesis. This observation is then applied to show that the Weak Conjecture does hold valid in P n for n ⩽ 3 . The main feature here is that the result is obtained although the Strong Hypothesis is not known to hold generally in P 2 and, further, P 2 presents special exceptional cases. Consequences of the main result in higher dimension are then examined. We note, then, that the full weight of the Strong Conjecture (and validity of the Strong Hypothesis) are not necessary toward using the main theorem in the next dimension. We end with the observation of how our viewpoint on the Strong Hypothesis pertains to extra algebraic information: namely, on the structure of the minimal free resolution of an ideal generated by linear forms.
The Individual in Recent Economics: Internalist and Externalist Conceptions

The Individual in Recent Economics: Internalist and Externalist Conceptions (by John B. Davis) - This paper examines different conceptions of the individual in a number of recent new approaches in economics, including prospect theory, market experimentalism, social preferences views, the game theoretic approaches of Michael Bacharach and Don Ross, and civil happiness views. These conceptions are classified as internalist or externalist according to whether they explain individuals by reference to their own characteristics or in terms of their relations to other individuals. It is argued that the task any particular conception of the individual in economics encounters is to explain how the individual concept applies at one and the same time to single persons, any of a person’s different selves, and collections of persons. The internalist conceptions reviewed are argued to ultimately be circular, and either fail to explain how individuals have multiple selves or how individuals can be part of collective individuals. The externalist conceptions reviewed offer potentially viable conceptions of individuals in both respects, but do not explain how individuals thus understood endure through processes of change. Keywords: Individual conception; Prospect theory; Market experimentalism; Social preferences; Michael Bacharach; Don Ross; Civil happiness.
An accurate waveguide port boundary condition for the time-domain finite-element method

This paper presents an accurate time-domain waveguide port boundary condition (WPBC) that can be used as a mesh truncation boundary condition to terminate a finite-element mesh. The formulation for deriving the boundary condition is based on multimodal expansion, and thus is related to the modal absorbing boundary conditions developed for the finite-difference time-domain method. The boundary condition is formulated for the general three-dimensional analysis of waveguides with an arbitrary cross section. All waveguide modes, including transverse electromagnetic, transverse electric, and transverse magnetic modes, are accounted for in the boundary condition in a unified formulation. Both propagating and evanescent modes can be properly absorbed. The proposed formulation is validated by numerical examples, and the accuracy and stability of the algorithm are investigated.