cssi/SciSciGPT-SciSciNet huggingface dataset:
Supported Gold Nanoparticle-Catalyzed Hydration of Alkynes under Basic Conditions

TiO2-supported nanosize gold particles catalyze the hydration of alkynes using morpholine as a basic cocatalyst. Unlike most homogeneous cationic gold catalysts, the TiO2–Au/morpholine system is weakly basic and is compatible with acid-sensitive functional groups (e.g., silyl ethers, ketals) or with a strongly coordinating group such as pyridine. What’s more, this gold catalyst can be recycled by simple filtration and works well in flow reactors.
Highly efficient syntheses of azetidines, pyrrolidines, and indolines via palladium catalyzed intramolecular amination of C(sp3)-H and C(sp2)-H bonds at γ and δ positions.

Efficient methods have been developed to synthesize azetidine, pyrrolidine, and indoline compounds via palladium-catalyzed intramolecular amination of C–H bonds at the γ and δ positions of picolinamide (PA) protected amine substrates. These methods feature relatively a low catalyst loading, use of inexpensive reagents, and convenient operating conditions. Their selectivities are predictable. These methods highlight the use of unactivated C–H bond, especially the C(sp3)–H bond of methyl groups, as functional groups in organic synthesis.
Structure and Dynamics of a Fusion Peptide Helical Hairpin on the Membrane Surface: Comparison of Molecular Simulations and NMR

The conserved N-terminal residues of the HA2 subunit of influenza hemagglutinin (fusion peptide) are essential for membrane fusion and viral entry. Recent NMR studies showed that the 23-residue fusion peptide forms a helical hairpin that undergoes rocking motion relative to the membrane surface on a nanosecond time scale. To compare with NMR and to obtain a detailed molecular picture of the peptide–membrane interaction, we performed molecular dynamics simulations of the fusion peptide in explicit dimyristoylphosphatidylcholine and with the IMM1 implicit membrane model. To account for low and neutral pH conditions, simulations were performed with acidic groups (E11 and D19) protonated and unprotonated, respectively. The hairpin structure was stable in the simulations, with the N-terminal helix buried more deeply into the hydrophobic membrane interior than the C-terminal helix. Interactions between the tryptophans in the fusion peptide and phospholipid residues contribute to peptide orientation. Higher flex...
A Primary Cause of Partisanship? Nomination Systems and Legislator Ideology

Many theoretical and empirical accounts of representation argue that primary elections are a polarizing influence. Likewise, many reformers advocate opening party nominations to nonmembers as a way of increasing the number of moderate elected officials. Data and measurement constraints, however, have limited the range of empirical tests of this argument. We marry a unique new data set of state legislator ideal points to a detailed accounting of primary systems in the United States to gauge the effect of primary systems on polarization. We find that the openness of a primary election has little, if any, effect on the extremism of the politicians it produces.
Heterogeneous Asymmetric Dynamic Conditional Correlation Model with Stock Return and Range

The paper considers the return and range model with dynamic conditional correlations (DCC). The paper suggests the new specifications for the asymmetric effects on log-volatilities and dynamic correlations, combined with long-run dependences. The new DCC model can be estimated by the quasi-maximum likelihood method. Empirical analysis on Nikkei 225, Hang Seng and Straits Times indices shows the daily, weekly and monthly pattern of asymmetric effects. For the period including the global financial crisis, the new DCC model provides plausible one-step-ahead forecasts of the VaR thresholds, and yields positive economic values of switching from other DCC models. Copyright © 2013 John Wiley & Sons, Ltd.
Unburdening America's Middle Class

Debt will be the story of the coming decade. How quickly we reduce the burden, says the author, will determine how fast the United States can return to full use of its resources, including labor. This comprehensive piece provides a guide to how we can deal with that sooner, rather than later.
Robust Differentiation of mRNA-Reprogrammed Human Induced Pluripotent Stem Cells Toward a Retinal Lineage

UNLABELLED The derivation of human induced pluripotent stem cells (hiPSCs) from patient-specific sources has allowed for the development of novel approaches to studies of human development and disease. However, traditional methods of generating hiPSCs involve the risks of genomic integration and potential constitutive expression of pluripotency factors and often exhibit low reprogramming efficiencies. The recent description of cellular reprogramming using synthetic mRNA molecules might eliminate these shortcomings; however, the ability of mRNA-reprogrammed hiPSCs to effectively give rise to retinal cell lineages has yet to be demonstrated. Thus, efforts were undertaken to test the ability and efficiency of mRNA-reprogrammed hiPSCs to yield retinal cell types in a directed, stepwise manner. hiPSCs were generated from human fibroblasts via mRNA reprogramming, with parallel cultures of isogenic human fibroblasts reprogrammed via retroviral delivery of reprogramming factors. New lines of mRNA-reprogrammed hiPSCs were established and were subsequently differentiated into a retinal fate using established protocols in a directed, stepwise fashion. The efficiency of retinal differentiation from these lines was compared with retroviral-derived cell lines at various stages of development. On differentiation, mRNA-reprogrammed hiPSCs were capable of robust differentiation to a retinal fate, including the derivation of photoreceptors and retinal ganglion cells, at efficiencies often equal to or greater than their retroviral-derived hiPSC counterparts. Thus, given that hiPSCs derived through mRNA-based reprogramming strategies offer numerous advantages owing to the lack of genomic integration or constitutive expression of pluripotency genes, such methods likely represent a promising new approach for retinal stem cell research, in particular, those for translational applications. SIGNIFICANCE In the current report, the ability to derive mRNA-reprogrammed human induced pluripotent stem cells (hiPSCs), followed by the differentiation of these cells toward a retinal lineage, including photoreceptors, retinal ganglion cells, and retinal pigment epithelium, has been demonstrated. The use of mRNA reprogramming to yield pluripotency represents a unique ability to derive pluripotent stem cells without the use of DNA vectors, ensuring the lack of genomic integration and constitutive expression. The studies reported in the present article serve to establish a more reproducible system with which to derive retinal cell types from hiPSCs through the prevention of genomic integration of delivered genes and should also eliminate the risk of constitutive expression of these genes. Such ability has important implications for the study of, and development of potential treatments for, retinal degenerative disorders and the development of novel therapeutic approaches to the treatment of these diseases.
Rubber Elasticity in the Range of Small Uniaxial Tensions and Compressions. Results for Poly(Dimethylsiloxane)

Abstract Results of uniaxial tension and compression experiments are reported on crosslinked poly(dimethylsiloxane) networks in the unswollen state over the range 0.5 1 region with decreasing slope. These results are in agreement with the predictions of recent elasticity theories that incorporate the effect of junction-chain entanglements in the elastic free energy.
Organocatalyzed Direct Glycosylation of Unprotected and Unactivated Carbohydrates

Organocatalyzed direct glycosylation of unprotected and unactivated carbohydrates is reported. This process is catalyzed by triphenylphosphine and tetrabromomethane at room temperature under neutral conditions. With this operationally simple protocol thermodynamically favored, glycosides were obtained in a very straightforward reaction.
Electron and energy transfer modulation with photochromic switches.

This tutorial review illustrates how work on the reversible interconversion between the colorless and colored forms of photochromic compounds can be exploited to modulate electron and energy transfer processes. Indeed, a photochrome can be designed to accept electrons or energy from a complementary donor in one of its two states only. Alternatively, the photoinduced transformations associated with a photochromic switch can be engineered to control the relative orientation and distance of donor–acceptor pairs. If either the donor or the acceptor is fluorescent, the photoregulated transfer of energy or electrons results in the modulation of the emission intensity. Thus, these fascinating molecular and supramolecular systems can advance the basic understanding of electron and energy transfer processes, while leading to viable operating principles to control light with light.
Optimal Energy Management in an Industrial Plant Using On-Site Generation and Demand Scheduling

Fierce global competition and reduced profit margins are forcing many manufacturing plants to maximize their operational efficiency. This includes the consumption of energy across the plant as well as the inventory buildup. To reduce the cost of energy purchased from the electric utility, the plant operator may use the available on-site generation or reschedule the operation of one or more workstations so that the plant is less heavily operational during peak-load hours when the price of electricity is high. All this must be done while considering the interdependencies between various workstations as well as the target production level (and possible penalties in case it is not met). These factors turn the energy management problem into a constrained optimization one where the operational constraints of the workstations, the capacity limits of available energy resources, and the financial information are all taken into account. Developing such a solution is the focus of this current paper. A nonlinear mixed-integer optimization problem is formulated here that tries to optimize the performance of an industrial plant subject to the above operational and technical constraints. The problem is solved for two scenarios, when the reverse power injection by the plant is allowed and when it is not.
Configurational entropy of polar glass formers and the effect of electric field on glass transition.

A model of low-temperature polar liquids is constructed that accounts for the configurational heat capacity, entropy, and the effect of a strong electric field on the glass transition. The model is based on the Pade-truncated perturbation expansions of the liquid state theory. Depending on parameters, it accommodates an ideal glass transition of vanishing configurational entropy and its avoidance, with a square-root divergent enumeration function at the point of its termination. A composite density-temperature parameter ργ/T, often used to represent combined pressure and temperature data, follows from the model. The theory is in good agreement with the experimental data for excess (over the crystal state) thermodynamics of molecular glass formers. We suggest that the Kauzmann entropy crisis might be a signature of vanishing configurational entropy of a subset of degrees of freedom, multipolar rotations in our model. This scenario has observable consequences: (i) a dynamical crossover of the relaxation tim...
Tug-of-war between driver and passenger mutations in cancer and other adaptive processes.

Cancer progression is an example of a rapid adaptive process where evolving new traits is essential for survival and requires a high mutation rate. Precancerous cells acquire a few key mutations that drive rapid population growth and carcinogenesis. Cancer genomics demonstrates that these few driver mutations occur alongside thousands of random passenger mutations—a natural consequence of cancer’s elevated mutation rate. Some passengers are deleterious to cancer cells, yet have been largely ignored in cancer research. In population genetics, however, the accumulation of mildly deleterious mutations has been shown to cause population meltdown. Here we develop a stochastic population model where beneficial drivers engage in a tug-of-war with frequent mildly deleterious passengers. These passengers present a barrier to cancer progression describable by a critical population size, below which most lesions fail to progress, and a critical mutation rate, above which cancers melt down. We find support for this model in cancer age–incidence and cancer genomics data that also allow us to estimate the fitness advantage of drivers and fitness costs of passengers. We identify two regimes of adaptive evolutionary dynamics and use these regimes to understand successes and failures of different treatment strategies. A tumor’s load of deleterious passengers can explain previously paradoxical treatment outcomes and suggest that it could potentially serve as a biomarker of response to mutagenic therapies. The collective deleterious effect of passengers is currently an unexploited therapeutic target. We discuss how their effects might be exacerbated by current and future therapies.
Photo-modulation of the spin Hall conductivity of mono-layer transition metal dichalcogenides

We report on a possible optical tuning of the spin Hall conductivity in mono-layer transition metal dichalcogenides. Light beams of frequencies much higher than the energy scale of the system (the off-resonant condition) do not excite electrons but rearrange the band structure. The rearrangement is quantitatively established using the Floquet formalism. For such a system of mono-layer transition metal dichalcogenides, the spin Hall conductivity (calculated with the Kubo expression in presence of disorder) exhibits a drop at higher frequencies and lower intensities. Finally, we compare the spin Hall conductivity of the higher spin-orbit coupled WSe2 to MoS2; the spin Hall conductivity of WSe2 was found to be larger.
Rh(II)-Catalyzed Reactions of Diazoesters with Organozinc Reagents

Rh(II)-catalyzed reactions of diazoesters with organozinc reagents are described. Diorganozinc reagents participate in reactions with diazo compounds by two distinct, catalyst-dependent mechanisms. With bulky diisopropylethyl acetate ligands, the reaction mechanism is proposed to involve initial formation of a Rh-carbene and subsequent carbozincation to give a zinc enolate. With Rh2(OAc)4, it is proposed that initial formation of an azine precedes 1,2-addition by an organozinc reagent. This straightforward route to the hydrazone products provides a useful method for preparing chiral quaternary α-aminoesters or pyrazoles via the Paul–Knorr condensation with 1,3-diketones. Crossover and deuterium labeling experiments provide evidence for the mechanisms proposed.
Parallel Algorithms for Summing Floating-Point Numbers

The problem of exactly summing n floating-point numbers is a fundamental problem that has many applications in large-scale simulations and computational geometry. Unfortunately, due to the round-off error in standard floating-point operations, this problem becomes very challenging. Moreover, all existing solutions rely on sequential algorithms which cannot scale to the huge datasets that need to be processed. In this paper, we provide several efficient parallel algorithms for summing n floating point numbers, so as to produce a faithfully rounded floating-point representation of the sum. We present algorithms in PRAM, external-memory, and MapReduce models, and we also provide an experimental analysis of our MapReduce algorithms, due to their simplicity and practical efficiency.
Ethics in Human Experimentation: Examples in Aeromedical Research

The existence of ethical standards directing how humans are utilized in clinical and human-use research have a significant impact on the conduct and outcome of aeromedical research. The validity of the data generated by human research is a direct result of the application of these ethical guidelines. The risk/benefit ratio evaluation can terminate a project even before its initiation. New technology, individual beliefs, and a changing society will continue to guarantee controversy over how human subjects should be screened and evaluated as well as how research should utilize them. Ethical guidelines are not cast in stone. Their interpretation is influenced by new experimental results, the individual researcher, the intended subject, the composition of human use committees, and the social environment. How we address new and old concerns alike will dictate the research environment of the future.
Endocrine Changes in Alzheimer’s Disease

Mild hypercortisolemia and dexamethasone suppression test nonsuppression have been reported in a subgroup of patients suffering from Alzheimer’s disease. Although no endocrine abnormalities can be consistently detected in patients with Alzheimer’s disease, assessment of neuroendocrine function might help identify subpopulations of patients with particular neurotransmission abnormalities who are likely to benefit from a specific pharmacologic strategy. For example, patients with Alzheimer’s disease, in whom cholinomimetic drugs produce the greatest elevation in plasma cortisol concentrations, appear to derive most symptomatic benefit from these drugs.
Clustered linear precoding for downlink network MIMO systems with partial CSI

We propose two novel clustered linear precoding schemes applicable to network multi-input multi-output systems using only partial channel state information to enhance the sum-rate of the system. Using a channel model that decomposes a multi-input multi-output channel matrix into transmit and receive steering vectors and assuming that only transmit steering vectors are available at the base transmit stations, we, first, propose a regularized channel inversion precoding scheme to enhance the sum-rate assuming only single-antenna users are available in the system. Next, because of the limitation of regularized channel inversion to handle users with multiple receive antennas, a novel block diagonalization method is proposed. We construct the precoding matrices that jointly eliminate inter-cell interference and maximize the sum-rate for a given input covariance matrix. Assuming total power constraint and per-base-station power constraints, optimal power allocation schemes are further developed to optimize the sum-rate. We analytically show that the sum-rate increases linearly with the number of users when only single-antenna users are present in the system. Numerical results show that at low signal-to-noise ratios, the block diagonalization precoding outperforms the regularized channel inversion in terms of the bit error rate; while at high signal-to-noise ratios, the regularized channel inversion provides a better performance. Copyright © 2016 John Wiley & Sons, Ltd.
Security Assessment of Electricity Distribution Networks Under DER Node Compromises

This paper focuses on the security assessment of electricity distribution networks (DNs) with vulnerable distributed energy resource (DER) nodes. The adversary model is a simultaneous compromise of DER nodes by strategic manipulation of generation setpoints. The loss to the defender (DN operator) includes loss of voltage regulation and cost of induced load control under supply-demand mismatch caused by the attack. A three-stage defender-attacker-defender (DAD) game is formulated: in Stage 1, the defender chooses a security strategy to secure a subset of DER nodes; in Stage 2, the attacker compromises a set of vulnerable DERs and injects false generation setpoints; in Stage 3, the defender responds by controlling loads and non-compromised DERs. Solving this trilevel optimization problem is hard due to nonlinear power flows and mixed-integer decision variables. To address this challenge, the problem is approximated by a tractable formulation based on an $\epsilon$ -linear power-flow model. The set of critical DER nodes and the setpoint manipulations characterizing the optimal attack strategy are computed. An iterative greedy approach to computing attacker-defender strategies for the original nonlinear problem is proposed. These results provide guidelines for optimal security investment and defender response in preattack and postattack conditions, respectively.
CT screening for lung cancer.

The Early Lung Cancer Action Project (ELCAP) recently demonstrated that earlier diagnosis of lung cancer can be achieved with CT, and these results have led to considerable demand for CT screening. The advisability of screening seems obvious, as screening has been shown to provide for lung cancer treatment at a relatively early stage, leading to a better chance to avert death from lung cancer than when treatment is prompted by symptoms and/or signs. There are, however, countervailing ideas that CT lung cancer screening has not yet been demonstrated to 'save lives." Further, it has been stated that CT screening has a notable problem of "overdiagnosis," meaning that screening finds lesions that are not life threatening, leading to unnecessary surgery. These concerns have led to the argument that assessing "lives saved," as well as the effects of overdiagnosis, can only be achieved with a randomized, controlled trial comparing CT screening with no screening, using a mortality endpoint. To this end, the National Lung Screening Trial (NLST) has been funded. This randomized, controlled trial is the most expensive screening study ever proposed. It compares CT screening with chest X-ray screening, and its designers envision that it will provide an answer about the benefit of CT screening, or lack thereof, in about 10 years. We do not question the value of the randomized design of 'treatment' trials for comparing competing interventions (treatments), but we have serious concerns about the use of randomization in the evaluation of a diagnostic test, such as CT. We feel that randomization is not necessary for evaluating a diagnostic test and may generate misleading results. Rather, we feel that the desired information is how often and how early is the disease diagnosed using that test. The purpose of this article is to raise the general level of concern about the underpinnings of such randomized 'screening' trials, and to convey some of the evidence that led to our pessimism about the NLST. Copyright 2003, Elsevier Science (USA). All rights reserved. onsiderable screening with chest X-ray has con
Purification and properties of short-chain acyl-CoA, medium-chain acyl-CoA, and isovaleryl-CoA dehydrogenases from human liver.

Short chain acyl-CoA (SCA), medium chain acyl-CoA (MCA), and isovaleryl-CoA (IV) dehydrogenases were purified to homogeneity from human liver using ammonium sulfate fractionation followed by DEAE-Sephadex A-50, hydroxyapatite, Matrex Gel Blue A, agarose-hexane-CoA, and Bio-Gel A-0.5 column chromatographies. The specific activities of the final preparations were enriched 507-, 750-, and 588-fold over those from the second ammonium sulfate fractionation step. The native molecular weights were estimated to be 168,000, 178,000, and 172,000, respectively, by gel filtration. Each of them exhibited, on sodium dodecyl sulfate/polyacrylamide gel electrophoresis, a single protein band with molecular weights of 41,000, 44,000, and 42,000, respectively, indicating a homotetrameric structure. UV/visual spectra, fluorescence spectra, and other evidence indicated that each contains 1 mol of FAD per subunit. They all utilized electron transfer flavoprotein (ETF) or phenazine methosulfate (PMS) as an electron acceptor. The products of SCA dehydrogenase/butyryl-CoA, MCA dehydrogenase/octanoyl-CoA, and IV dehydrogenase/isovaleryl-CoA reactions were identified as crotonyl-CoA, 2-octenoyl-CoA, and 3-methylcrotonyl-CoA, respectively, using gas chromatography. Kinetic parameters Vappmax and Kappm) of these enzymes for various acyl-CoA substrates, as well as Kappm values for ETF and PMS are presented. In general, the substrate specificities of human SCA, MCA, and IV dehydrogenases are slightly less stringent than those of their rat counterparts and resemble those of their bovine and porcine counterparts. The pattern of substrate specificity for these enzymes determined using ETF as electron acceptor significantly differed from that determined using PMS. All of them were severely inhibited by (methylenecyclopropyl)acetyl-CoA.
A Genetic Animal Model of Alcoholism for Screening Medications to Treat Addiction

The purpose of this review is to present up-to-date pharmacological, genetic, and behavioral findings from the alcohol-preferring P rat and summarize similar past work. Behaviorally, the focus will be on how the P rat meets criteria put forth for a valid animal model of alcoholism with a highlight on its use as an animal model of polysubstance abuse, including alcohol, nicotine, and psychostimulants. Pharmacologically and genetically, the focus will be on the neurotransmitter and neuropeptide systems that have received the most attention: cholinergic, dopaminergic, GABAergic, glutamatergic, serotonergic, noradrenergic, corticotrophin releasing hormone, opioid, and neuropeptide Y. Herein, we sought to place the P rat's behavioral and neurochemical phenotypes, and to some extent its genotype, in the context of the clinical literature. After reviewing the findings thus far, this chapter discusses future directions for expanding the use of this genetic animal model of alcoholism to identify molecular targets for treating drug addiction in general.
Decarboxylative Anti-Michael Addition to Olefins Mediated by Photoredox Catalysis

Decarboxylative coupling of carboxylic acids with activated olefins has been accomplished using visible light photoredox catalysis. The strategic placement of a radical-stabilizing aromatic group at the β-position of the olefin component biases the regioselectivity of the addition, allowing reliable, facile access to anti-Michael-type products from readily available precursors. The scope of this methodology was demonstrated with a range of carboxylic acids and appropriately substituted olefins and was applied toward a two-step synthesis of the antiarrhythmic agent encainide.
Silylaryl Halides Can Replace Triflates as Aryne Precursors

Silylaryl bromides and iodides can be prepared in one step from commercially available starting materials. Arynes can be generated from these compounds under conditions nearly identical to those employed for silylaryl triflates. Three distinct transformations, ortho-arylation of N-tritylanilines, intermolecular addition of arynes to amides, and reaction of ureas with arynes, were shown to be successful for the new aryne precursors. The main advantage of silylaryl halides relative to silyl aryl triflates is their one-step preparation from commercially available starting materials.
Economic Management in the General Theory

Keynes insisted, ‘An excessive output of consumption goods is not expansive’ (Keynes to Harrod, 17 August 1938, CW XIV, p. 324). The chapter of the General Theory devoted to the marginal propensity to consume ended with the assertion that stimulating consumption is useful because it results in a disproportionate increase in investment (Keynes, 1936, pp. 104–6).
Using Calibration Weighting to Adjust for Nonresponse Under a Plausible Model (with full appendices)

Calibration forces the weighted estimates of certain variables to match known or alternatively estimated population totals called benchmarks. It can be used to correct for sample-survey nonresponse or for coverage error resulting from frame undercoverage or unit duplication. The quasi-randomization theory supporting its use in nonresponse adjustment treats response as an additional phase of random sampling. The functional form of a quasi-random response model is assumed to be known, its parameter values estimated implicitly through the creation of calibration weights. Unfortunately, calibration depends upon known benchmark totals
‘So many books they don’t even all fit on the bookshelf’: An examination of low-income mothers’ home literacy practices, beliefs and influencing factors:

Given the need to enhance the academic language and early literacy skills of young children from low-income homes and the importance of the home literacy environment in supporting children’s develo...
Search Costs, Behavioral Biases, and Information Intermediary Effects

In many markets, buyers, sellers, and their agents have differential information about the quality of heterogeneous assets. We study negotiated transaction prices in the commercial real estate market, which is characterized by heterogeneous assets, illiquidity, and highly segmented local markets, all of which increase the importance of asymmetric information in negotiated pricing outcomes. Using 114,588 industrial, multi-family and office sale transactions that occurred during 1997–2011, we document that distant commercial real estate buyers pay, on average, premiums of 4 % to 15 % relative to local buyers, controlling for individual property characteristics as well as time fixed-effects. We also examine the extent to which the sources of these observed premiums are a product of higher search costs/information asymmetry problems associated with distance (search cost channel) or a result of reference-dependence preference/anchoring based on the price levels in the investors’ local market (behavioral biases channel). Our results suggest the observed price premiums are explained by distant investors who face higher search costs and are at an information disadvantage compared to investors located in closer proximity to the property. In contrast, anchoring plays a more muted role in explaining observed premiums. The use of an intermediary (broker) increases, on average, the acquisition prices of buyers and decreases the disposition prices of sellers by 3 % to 8 %. This result is consistent with the incentive real estate agents have to convince sellers to dispose of their properties too quickly and to convince buyers to search less and therefore pay higher prices.
CATASTROPHIC MOM WEAR TRIGGERED IN A HIP SIMULATOR STUDY BY INTRUSION OF METAL PARTICLES

Introduction One unpredictable clinical risk with THA may be impingement of a metal cup rim against a metal femoral-neck, with concomitant release of metal particles. Our objective was to determine if metal debris could be one trigger for catastrophic MOM wear. Patients/Materials & Methods To simulate release of metal debris, we added metal particles (CoCr #230, Ti6Al4V #340) to six 38mm MOM bearings at beginning of each simulator test interval. The weekly 500,000 cycle intervals were replicated 10 times to acquire 5-million duty cycles. Flakes of polymerized bone cement (PMMA) were scraped from a retrieved TKR and used as control debris (N = 1,300 particles; 3 MOM). Results Metal debris turned all lubricants black within first hour of test, and consistently over the study. Cement flakes elicited no such lubricant changes. MOM wear-rates using PMMA, CoCr, and Ti64 debris were 0.3, 4.1, and 6.4 cubic millimetes per million cycles, respectively, revealing statistically significant differences. The CoCr debris allotment produced ×30 times its weight in surface wear; the Ti6Al4V debris produced ×50 times its weight in CoCr wear. Discussion Successful MOM bearings were reputed to have low friction due to fluid-film lubrication. Nevertheless, any THA impingement that can release metal debris may compromise such thin films. This simulator study of MOM bearings running under abrasive conditions revealed that MOM wear-rates with CoCr and Ti6Al4V debris were raised ×14 and ×23 times greater than that of PMMA debris. Conclusion The insertion of metal debris, simulating just one impingement episode in 500,000 gait cycles, created a ×30–50 times multiplier effect in production of CoCr debris. The resulting black lubricants may be directly analogous to the black tissues noted around high-wearing MOM bearings. Thus the nemesis of MOM THA may be an extreme sensitivity to 3rd-body wear particles.
The James Webb Space Telescope

The James Webb Space Telescope (JWST) will extend the discoveries of the Hubble Space Telescope by deploying a large cooled infrared telescope at the Sun-Earth Lagrange point L2. It will have a 6 m aperture and three instruments covering the wavelength range from 0.6 to 28 µm.
Lessons learned from comparing molecular dynamics engines on the SAMPL5 dataset

We describe our efforts to prepare common starting structures and models for the SAMPL5 blind prediction challenge. We generated the starting input files and single configuration potential energies for the host-guest in the SAMPL5 blind prediction challenge for the GROMACS, AMBER, LAMMPS, DESMOND and CHARMM molecular simulation programs. All conversions were fully automated from the originally prepared AMBER input files using a combination of the ParmEd and InterMol conversion programs. We find that the energy calculations for all molecular dynamics engines for this molecular set agree to better than 0.1 % relative absolute energy for all energy components, and in most cases an order of magnitude better, when reasonable choices are made for different cutoff parameters. However, there are some surprising sources of statistically significant differences. Most importantly, different choices of Coulomb's constant between programs are one of the largest sources of discrepancies in energies. We discuss the measures required to get good agreement in the energies for equivalent starting configurations between the simulation programs, and the energy differences that occur when simulations are run with program-specific default simulation parameter values. Finally, we discuss what was required to automate this conversion and comparison.
Commentary on the New Charity Undertakings Law: Socialist Modernization through Collective Organizations

China’s new Charity Law represents the culmination of over a decade of planning for the appropriate development of the productive forces of the charity sector in aid of socialist modernization. Together with the related Foreign NGO Management Law, it represents an important advance in the organization of the civil society sector within emerging structures of Socialist Rule of Law principles. While both Charity and Foreign NGO Management Laws could profitably be considered as parts of a whole, each merits discussion for its own unique contribution to national development. Moreover, while analysis tends to focus on legal conformity of the Charity Law to the state constitution, little work has been done to analyze the relationship of the Charity Law to the political constitution of China. This essay seeks to fill that gap by considering the role of the Charity Law through the lens of the Constitution of the Communist Party of China. More specifically, the essay examines the extent to which the provisions of the Charity Law, and its underlying policies, contribute to the implementation and realization of the Chinese Communist Party ( CCP ) Basic Line and in the context of the overall political policy of “socialist modernization which has served as the core of the political line of the CCP since the last decades of the 20th century. The essay is organized as follows: Section II considers the specific provisions of the Charity Law, with some reference to changes between the first draft and the final version of the Charity Law. Section III then considers some of the more theoretical considerations that suggest a framework for understanding the great contribution of the Charity Law as well as the challenges that remain for the development of the productive forces of the civil society sector at this historical stage of China’s development.
Justice Reinvestment and the State of State Sentencing Reform

Part of the Law Commons Publication Information Published as Michael M. O'Hear, Justice Reinvestment and the State of State Sentencing Reform, 29 Fed. Sent'g Rep. 1 (2016). © 2016 by the Regents of the University of California on behalf of the Vera Institute of Justice. Copying and permissions notice: Authorization to copy this content beyond fair use (as specified in Sections 107 and 108 of the U. S. Copyright Law) for internal or personal use, or the internal or personal use of specific clients, is granted by the Regents of the University of California on behalf of the Vera Institute of Justice for libraries and other users, provided that they are registered with and pay the specified fee via Rightslink® on Caliber (http://caliber.ucpress.net/) or directly with the Copyright Clearance Center, http://www.copyright.com.
A complete characterization of statistical query learning with applications to evolvability

Statistical query (SQ) learning model of Kearns is a natural restriction of the PAC learning model in which a learning algorithm is allowed to obtain estimates of statistical properties of the examples but cannot see the examples themselves (Kearns, 1998 [29]). We describe a new and simple characterization of the query complexity of learning in the SQ learning model. Unlike the previously known bounds on SQ learning (Blum, et al., 1994; Bshouty and Feldman, 2002; Yang, 2005; Balcazar, et al., 2007; Simon, 2007 [9,11,42,3,37]) our characterization preserves the accuracy and the efficiency of learning. The preservation of accuracy implies that our characterization gives the first characterization of SQ learning in the agnostic learning framework of Haussler (1992) [23] and Kearns, Schapire and Sellie (1994) [31]. The preservation of efficiency is achieved using a new boosting technique and allows us to derive a new approach to the design of evolution algorithms in [email protected]?s model of evolvability (Valiant, 2009 [40]). We use this approach to demonstrate the existence of a large class of monotone evolution algorithms based on square loss performance estimation. These results differ significantly from the few known evolution algorithms and give evidence that evolvability in [email protected]?s model is a more versatile phenomenon than there had been previous reason to suspect.
After the tide: Commodity currencies and global trade

Abstract The decade prior to the Great Recession saw a boom in global trade and rising transportation costs. High-yielding commodity exporters׳ currencies appreciated, boosting carry trade profits. The Global Recession sharply reversed these trends. We interpret these facts with a two-country general equilibrium model that features specialization in production and endogenous fluctuations in trade costs. Slow adjustment in the shipping sector generates boom–bust cycles in freight rates and, as a consequence, in currency risk premia. We validate these predictions using global shipping data. Our calibrated model explains about 57% of the narrowing of interest rate differentials post-crisis.
Generative Multi-Adversarial Networks

Generative adversarial networks (GANs) are a framework for producing a generative model by way of a two-player minimax game. In this paper, we propose the \emph{Generative Multi-Adversarial Network} (GMAN), a framework that extends GANs to multiple discriminators. In previous work, the successful training of GANs requires modifying the minimax objective to accelerate training early on. In contrast, GMAN can be reliably trained with the original, untampered objective. We explore a number of design perspectives with the discriminator role ranging from formidable adversary to forgiving teacher. Image generation tasks comparing the proposed framework to standard GANs demonstrate GMAN produces higher quality samples in a fraction of the iterations when measured by a pairwise GAM-type metric.
Warmth and Demand: The Relation Between Students' Perceptions of the Classroom Environment and Achievement Growth

Theory suggests that African American students benefit from warm and demanding teachers. This study examines the relation between students' perceptions of 634 teachers' warm demander characteristics and achievement growth in fourth and fifth grades (Mstudent age = 9–11.5 years). Analyses explored whether relations were moderated by the proportion of African American students in the classroom or the ethnic match or mismatch between African American students and their teachers. Results indicated that students' perceptions of teachers' demand (challenge and control) related to student achievement growth. Findings showed a stronger relation between challenge and academic growth in classrooms with more African American students, but no significant findings were identified for ethnic match or mismatch.
Parallel computation using active self-assembly

We study the computational complexity of the recently proposed nubots model of molecular-scale self-assembly. The model generalises asynchronous cellular automata to have non-local movement where large assemblies of molecules can be moved around, analogous to millions of molecular motors in animal muscle effecting the rapid movement of macroscale arms and legs. We show that nubots is capable of simulating Boolean circuits of polylogarithmic depth and polynomial size, in only polylogarithmic expected time. In computational complexity terms, we show that any problem from the complexity class NC is solved in polylogarithmic expected time on nubots that use a polynomial amount of workspace. Along the way, we give fast parallel algorithms for a number of problems including line growth, sorting, Boolean matrix multiplication and space-bounded Turing machine simulation, all using a constant number of nubot states (monomer types). Circuit depth is a well-studied notion of parallel time, and our result implies that nubots is a highly parallel model of computation in a formal sense. Asynchronous cellular automata are not capable of such parallelism, and our result shows that adding a movement primitive to such a model, to get the nubots model, drastically increases parallel processing abilities.
A Statistical Approach to Continuous Self-Calibrating Eye Gaze Tracking for Head-Mounted Virtual Reality Systems

We present a novel, automatic eye gaze tracking scheme inspired by smooth pursuit eye motion while playing mobile games or watching virtual reality contents. Our algorithm continuously calibrates an eye tracking system for a head mounted display. This eliminates the need for an explicit calibration step and automatically compensates for small movements of the headset with respect to the head. The algorithm finds correspondences between corneal motion and screen space motion, and uses these to generate Gaussian Process Regression models. A combination of those models provides a continuous mapping from corneal position to screen space position. Accuracy is nearly as good as achieved with an explicit calibration step.
The Spatial Segregation of Ethnic and Demographic Groups: Comparative Evidence from Stockholm and San Francisco

Abstract This paper compares the level of spatial segregation by race or ethnicity with the level of spatial segregation by household type in two metropolitan areas with similar incomes and demographic compositions, but with very different racial proportions. We compare census tract data for the San Francisco Bay area for 1980, a region with six large ethnic divisions, with analogous data for the Stockholm metropolitan area, a region with a much more homogeneous racial composition. An extensive comparison of entropy measures of segregation in the two regions is presented, including for Stockholm, an analysis, replicated in two very different metropolitan regions, is that spatial segregation by race or ethnicity is unrelated to the principal economic factors which presumably underlie spatial segregation by income class or demographic grouping.
Quasi-Spectral Sparse Bi-Global Stability Analysis of Compressible Channel Flow over Complex Impedance

We have developed a fully sparse, compact-scheme based biglobal stability analysis numerical solver applied, for the scope of the current paper, to the investigation of the effects of impedance boundary conditions (IBCs) on the structure of a fully developed compressible turbulent channel flow. A sixth-order compact finite difference scheme is used to discretize the linearized Navier-Stokes equations leading to a Generalized Eigenvalue Problem (GEVP). Sparsity is retained by explicitly introducing derivatives of the perturbation as additional unknowns, increasing the overall problem size (number of columns $\times$ number of rows) while significantly reducing the number of non-zeros and the computational cost with respect to traditional implementations yielding otherwise dense matrix blocks. The resulting GEVP is coded in Python and solved employing an Message Passing Interface (MPI) parallelized PETSc-based sparse eigenvalue solver adopting a modified Arnoldi algorithm. Base flow is taken from impermeable isothermal-wall turbulent channel flow simulations at bulk Reynolds number, $Re_b= 6900$ and Mach number, $M_b = 0.85$. The eigenvalue spectrum calculated in the biglobal stability analysis shows distinct groups of modes associated with a discrete set of streamwise wave numbers accommodated by computational domain. An iterative strategy for the imposition of the complex IBCs, which are a nonlinear function of the real-valued (Fourier) frequency in the GEVP, has been devised. The adopted IBC specifically represents an array of sub-surface-mounted Helmholtz cavities with resonant frequency, $f_{res}$, covered by a porous sheet with permeability inversely proportional to the impedance resistance $R$. The tunable resonant frequency has been shown to be an attractor for the instability, yielding a single unstable mode at that frequency.
X-Ray and Optical Study of the Gamma-ray Source 3FGL J0838.8-2829: Identification of a Candidate Millisecond Pulsar Binary and an Asynchronous Polar

We observed the field of the Fermi source 3FGL J0838.8−2829 in optical and X-rays, initially motivated by the cataclysmic variable (CV) 1RXS J083842.1−282723 that lies within its error circle. Several X-ray sources first classified as CVs have turned out to be γ-ray emitting millisecond pulsars (MSPs). We find that 1RXS J083842.1−282723 is in fact an unusual CV, a stream-fed asynchronous polar in which accretion switches between magnetic poles (that are ≈120° apart) when the accretion rate is at minimum. High-amplitude X-ray modulation at periods of 94.8 ± 0.4 minutes and 14.7 ± 1.2 hr are seen. The former appears to be the spin period, while the latter is inferred to be one-third of the beat period between the spin and the orbit, implying an orbital period of 98.3 ± 0.5 minutes. We also measure an optical emission-line spectroscopic period of 98.413 ± 0.004 minutes, which is consistent with the orbital period inferred from the X-rays. In any case, this system is unlikely to be the γ-ray source. Instead, we find a fainter variable X-ray and optical source, XMMU J083850.38−282756.8, that is modulated on a timescale of hours in addition to exhibiting occasional sharp flares. It resembles the black widow or redback pulsars that have been discovered as counterparts of Fermi sources, with the optical modulation due to heating of the photosphere of a low-mass companion star by, in this case, an as-yet undetected MSP. We propose XMMU J083850.38−282756.8 as the MSP counterpart of 3FGL J0838.8−2829.
Backward Raman Amplification in the Long-wavelength Infrared

The wealth of work in backward Raman amplification in plasma has focused on the extreme intensity limit; however, backward Raman amplification may also provide an effective and practical mechanism for generating intense, broad bandwidth, long-wavelength infrared radiation (LWIR). An electromagnetic simulation coupled with a relativistic cold fluid plasma model is used to demonstrate the generation of picosecond pulses at a wavelength of 10 μm with terawatt powers through backward Raman amplification. The effects of collisional damping, Landau damping, pump depletion, and wave breaking are examined, as well as the resulting design considerations for an LWIR Raman amplifier.