cssi/SciSciGPT-SciSciNet huggingface dataset:
Options for financing lifelong learning

How should lifelong learning be financed? The author attempts to answer the question by creating a framework for analyzing different education financing mechanisms in light of particular characteristics of lifelong learning. The framework compares the different financing alternatives on four dimensions: (1) who ultimately pays for the education, (2) who finances its immediate costs, (3) how payments are made, and (4) who collects the payments. The author uses specific characteristics of lifelong learning to determine which among the financing alternatives are most useful. The characteristics are that the individual should decide what and where to study, carry a significant part of the financial burden, and be encouraged to continue learning through all life stages. The author analyzes the financing alternatives according to who ultimately pays for the education. Hence, the alternatives are classified either as cost-recovery or cost-subsidization alternatives. Cost-recovery alternatives include traditional loans, a graduate tax, human capital contracts, and income-contingent loans. Subsidization alternatives are those in which the state directly subsidizes institutions or in which the state gives vouchers to students. The author concludes that combining income-contingent loans and human capital contracts with vouchers is the most efficient and equitable method for financing lifelong learning. The author discusses the role of governments and multilateral organizations in improving the financing of lifelong learning. He assesses shifting toward cost-recovery alternatives, focusing on collection of payments, and aiming for the involvement of private capital as key issues that should be addressed to ensure that lifelong learning will be available for all equitably and efficiently.
Alternative synthetic routes to 2′,3′-didehydro-2′,3′-dideoxy-5-hydroxymethyluridine

Abstract Alternative syntheses for the nucleoside analogue 2′,3′-didehydro-2′,3′-dideoxy-5-hydroxymethyluridine starting from 5-methyluridine and uridine are described.
Synthesis and monoamine transporter affinity of new 2β-carbomethoxy-3β-[4-(substituted thiophenyl)]phenyltropanes: discovery of a selective SERT antagonist with picomolar potency

Abstract Preparation of cocaine analogues has been aimed largely at development of stable compounds with high affinity and selectivity for the dopamine transporter (DAT). We now report the synthesis and monoamine transporter affinity of 10 new 2β-carbomethoxy-3β-[4-(substituted thiophenyl)]phenyltropanes. Among these, compound 4b exhibited very high affinity for the serotonin transporter (SERT: Ki = 17 pM) and good selectivity over dopamine (DAT: 710-fold) and norepinephrine transporters (NET: 11,100-fold).
Java Virtual Machine support for object serialization

Distributed computing has become increasingly popular in the high-performance community. Java's remote method invocation (RMI) provides a simple, yet powerful method for implementing parallel algorithms. The performance of RMI has been less than adequate, however, and object serialization is often identified as a major performance inhibitor. We believe that object serialization is best performed in the Java Virtual Machine (JVM), where information regarding object layout and hardware communication resources are readily available. We implement a subset of Java's object serialization protocol in native code, using the Java Native Interface (JNI) and JVM internals. Experiments show that our approach is up to eight times faster than Java's original object serialization protocol for array objects. Also, for linked data structures our approach obtains a moderate speedup and better scalability. Evaluation of our object serialization implementation in an RMI framework indicates that a higher throughput can be obtained. Parallel applications, written using RMI, obtain better speedups and scalability when this more efficient object serialization is used. Copyright © 2003 John Wiley & Sons, Ltd.
Multidisciplinary design optimization of dynamic engineering systems

Dynamic engineering systems are playing an increasingly important role in society, especially as active and autonomous dynamic systems become more mature and prevalent across a variety of domains. Successful design of complex dynamic systems requires multidisciplinary analysis and design techniques. While multidisciplinary design optimization has been used successfully for the development of many dynamic systems, the established multidisciplinary design optimization formulations were developed around fundamentally static system models. General multidisciplinary design optimization approaches that address the specific needs of dynamic system design are still lacking. In this article, the use of multidisciplinary design optimization for dynamic system design is reviewed, associated challenges are identified, related efforts such as optimal control are discussed, and a vision for fully integrated design approaches is presented. Finally, a set of exciting new directions that provide an opportunity for fundame...
Rapid synthesis of substituted 5-phenyl-1,3-dioxolan-4-ones under microwave-induced solvent-free conditions

Under microwave irradiation and without solvent, racemic and optically pure mandelic acid readily condenses with aldehydes and ketones to give 2-alkyl substituted 5-phenyl-1,3-dioxolan-4-ones in good yield.
Synthesis of Nτ-arylhistidine derivatives via direct N-arylation

Abstract N τ -Aryl-histidine derivatives were synthesized using a modified one-step Cu-catalyzed coupling of aryl halides and N -acetylhistidine methyl ester. The latter is much less reactive than imidazole toward aryl halides. p -Chloroiodobenzene coupled with iodine displacement only, whereas m - and p -bromoiodobenzene both gave mixtures of bromo- and iodophenyl products.
Autoencoders, Unsupervised Learning, and Deep Architectures

Autoencoders play a fundamental role in unsupervised learning and in deep architectures for transfer learning and other tasks. In spite of their fundamental role, only linear autoencoders over the real numbers have been solved analytically. Here we present a general mathematical framework for the study of both linear and non-linear autoencoders. The framework allows one to derive an analytical treatment for the most non-linear autoencoder, the Boolean autoencoder. Learning in the Boolean autoencoder is equivalent to a clustering problem that can be solved in polynomial time when the number of clusters is small and becomes NP complete when the number of clusters is large. The framework sheds light on the different kinds of autoencoders, their learning complexity, their horizontal and vertical composability in deep architectures, their critical points, and their fundamental connections to clustering, Hebbian learning, and information theory.
Catalyst-Free Preparation of Heterocyclic Thienyl Sulfides

AbstractDescribed in this work is a catalyst-free, in most cases neat, preparation of heterocyclic thienyl sulfides. This method utilizes 2-thiophenethiol and various activated halogenated heterocycles in a substitution-type reaction to form an interesting array of sulfides. Yields obtained are comparable to other published methods, and the reaction requires milder conditions, has shorter reaction times, and most times eliminates the need for column chromatography during workup.
Low SNR signal processing for head/media contact detection in HDD

A new methodology for processing a grossly undersampled hard disk drive (HDD) position error signal (PES) is proposed to improve the head-disk contact detection process. The proposed method is a combination of compressive sampling (CS) and adaptive discrete wavelet transform (ADWT) techniques. Here, CS is employed to reconstruct the PES information from very few revolutions of data sampled with the HDD servo system while ADWT is utilized for extracting head-disk interface (HDI) modulation changes during thermal protrusion of the read/write element. An example of HDD level signal processing is provided where CS synthesized PES is processed using a discrete wavelet transform embedded into an entropy minimization and statistical characterization framework.
AN ECONOMIC ANALYSIS OF NANOFOOD LABELING

Abstract The paper examines the economic effects of labeling food nanotechnology products using an analytical framework of heterogeneous consumers and imperfectly competitive suppliers. Labeling results in increased costs for nanofood producers (the cost effect of the labeling policy), reduced consumer uncertainty regarding the nature of the food product (certainty effect), and can affect consumer attitudes towards nanofoods by being perceived as a warning signal (stigma effect). In this context, nanofood labeling can change the perceived quality differences between nanofoods and their conventional and organic counterparts, with such changes being more salient when the stigma effect is large, when consumers have low awareness of food nanotechnology in the absence of labeling, and/or when competition among nanofood suppliers is more intense. Despite its empirical relevance, the impact of a labeling policy on consumer preferences (and the economic ramifications of such impact) has largely been ignored by the theoretical literature on the economics of labels. Our analysis shows that it matters. Specifically, our study shows that the market and welfare effects of labeling are case-specific and dependent on consumer awareness of, and attitudes towards food nanotechnology before and after the introduction of the policy as well as the relative magnitude of the cost, certainty and stigma effects of nanofood labeling. Our analytical findings also suggest that the effects of nanofood labels on consumer welfare are asymmetric with certain groups of consumers benefiting even when labeling has a stigma effect on nanofoods.
Atlantic Generating Station

Studies have indicated that ∼1000 MW(e) of base-load generation must be installed each year, beginning in the early 1980’s, if the demand for power in New Jersey is to be met.Nuclear power is the p...
Penalized maximum likelihood estimation of multi-layered Gaussian graphical models

Analyzing multi-layered graphical models provides insight into understanding the conditional relationships among nodes within layers after adjusting for and quantifying the effects of nodes from other layers. We obtain the penalized maximum likelihood estimator for Gaussian multi-layered graphical models, based on a computational approach involving screening of variables, iterative estimation of the directed edges between layers and undirected edges within layers and a final refitting and stability selection step that provides improved performance in finite sample settings. We establish the consistency of the estimator in a high-dimensional setting. To obtain this result, we develop a strategy that leverages the biconvexity of the likelihood function to ensure convergence of the developed iterative algorithm to a stationary point, as well as careful uniform error control of the estimates over iterations. The performance of the maximum likelihood estimator is illustrated on synthetic data.
Measuring experimental error in microprocessor simulation

We measure the experimental error that arises from the use of non-validated simulators in computer architecture research, with the goal of increasing the rigor of simulation-based studies. We describe the methodology that we used to validate a microprocessor simulator against a Compaq DS-10L workstation, which contains an Alpha 21264 processor. Our evaluation suite consists of a set of 21 microbenchmarks that stress different aspects of the 21264 microarchitecture. Using the microbenchmark suite as the set of workloads, we describe how we reduced our simulator error to an arithmetic mean of 2%, and include details about the specific aspects of the pipeline that required extra care to reduce the error. We show how these low-level optimizations reduce average error from 40% to less than 20% on macrobenchmarks drawn from the SPEC2000 suite. Finally, we examine the degree to which performance optimizations are stable across different simulators, showing that researchers would draw different conclusions, in some cases, if using validated simulators.
Tax Policy and Heterogeneous Investment Behavior

Abstract We estimate the effect of temporary tax incentives on equipment investment using shifts in accelerated depreciation. Analyzing data for over 120,000 firms, we present three findings. First...
A nonparametric comparison of conditional distributions with nonnegligible cure fractions.

Survival data with nonnegligible cure fractions are commonly encountered in clinical cancer clinical research. Recently, several authors (e.g. Kuk and Chen, Biometrika 79 (1992) 531; Maller and Zhou, Journal of Applied Probability, 30 (1993) 602; Peng and Dear, Biometrics, 56 (2000) 237; Sy and Taylor, Biometrics 56 (2000) 227) have proposed to use semiparametric cure models to analyze such data. Much of the existing work has been emphasized on cure detections and regression techniques. In contrast, this project focuses on the hypothesis testing in the presence of a cure fraction. Specifically, our interest lies in detecting whether there exists survival differences among noncured patients between treatment arms. For this purpose, we investigate the use of a modified Cramer-von Mises statistic for two-sample survival comparisons within the framework of cure models. Such a test has been studied by Tamura et al., (Statistics in Medicine 19, 2000, 2169) using bootstrap procedure. We will focus on developing asymptotic theory and convergent algorithms in this paper. We show that the limiting distributions of the Cramer-von Mises statistic under the null hypothesis can be represented by stochastic integrals and a weighted noncentral chi-squares. Both representations lead to concrete numerical schemes for computing the limiting distributions. The algorithms can be easily implemented for data analysis and significantly reduce computing time compared to the bootstrap approach. For illustrative purposes, we apply the proposed test to a published clinical trial.
Reaction-Based Probes for Imaging Mobile Zinc in Live Cells and Tissues

Chelatable, or mobile, forms of zinc play critical signaling roles in numerous biological processes. Elucidating the action of mobile Zn(II) in complex biological environments requires sensitive tools for visualizing, tracking, and manipulating Zn(II) ions. A large toolbox of synthetic photoinduced electron transfer (PET)-based fluorescent Zn(II) sensors are available, but the applicability of many of these probes is limited by poor zinc sensitivity and low dynamic ranges owing to proton interference. We present here a general approach for acetylating PET-based probes containing a variety of fluorophores and zinc-binding units. The new sensors provide substantially improved zinc sensitivity and allow for incubation of live cells and tissue slices with nM probe concentrations, a significant improvement compared to the μM concentrations that are typically required for a measurable fluorescence signal. Acetylation effectively reduces or completely quenches background fluorescence in the metal-free sensor. Bi...
Extended Local Cohomology and Local Homology

We present an in-depth exploration of the module structures of local (co)homology modules (moreover, for complexes) over the completion \(\widehat {R}^{\mathcal {a}}\) of a commutative noetherian ring R with respect to a proper ideal \(\mathcal {a}\). In particular, we extend Greenlees-May Duality and MGM Equivalence to track behavior over \(\widehat {R}^{\mathcal {a}}\), not just over R. We apply this to the study of two recent versions of homological finiteness for complexes, and to certain isomorphisms, with a view toward further applications. We also discuss subtleties and simplifications in the computations of these functors.
Even-denominator fractional quantum Hall effect at a Landau level crossing

The fractional quantum Hall effect (FQHE), observed in two-dimensional (2D) charged particles at high magnetic fields, is one of the most fascinating, macroscopic manifestations of a many-body state stabilized by the strong Coulomb interaction. It occurs when the filling factor ($\ensuremath{\nu}$) of the quantized Landau levels (LLs) is a fraction, which, with very few exceptions, has an odd denominator. In 2D systems with additional degrees of freedom it is possible to cause a crossing of the LLs at the Fermi level. At and near these crossings, the FQHE states are often weakened or destroyed. Here we report the observation of an unusual crossing of the two lowest-energy LLs in high-mobility GaAs 2D hole systems, which brings to life a new even-denominator FQHE at $\ensuremath{\nu}=1/2$.
The Difference Between a Discrete and Continuous Harmonic Measure

We consider a discrete-time, continuous-state random walk with steps uniformly distributed in a disk of radius h. For a simply connected domain D in the plane, let \(\omega _h(0,\cdot ;D)\) be the discrete harmonic measure at \(0\in D\) associated with this random walk, and \(\omega (0,\cdot ;D)\) be the (continuous) harmonic measure at 0. For domains D with analytic boundary, we prove there is a bounded continuous function \(\sigma _D(z)\) on \(\partial D\) such that for functions g which are in \(C^{2+\alpha }(\partial D)\) for some \(\alpha >0\) we have $$\begin{aligned} \lim _{h\downarrow 0} \frac{\int _{\partial D} g(\xi ) \omega _h(0,|\mathrm{d}\xi |;D) -\int _{\partial D} g(\xi )\omega (0,|\mathrm{d}\xi |;D)}{h} = \int _{\partial D}g(z) \sigma _D(z) |\mathrm{d}z|. \end{aligned}$$ We give an explicit formula for \(\sigma _D\) in terms of the conformal map from D to the unit disk. The proof relies on some fine approximations of the potential kernel and Green’s function of the random walk by their continuous counterparts, which may be of independent interest.
Ando dilations and inequalities on noncommutative varieties

Ando proved a dilation result that implies his celebrated inequality which says that if T1 and T2 are commuting contractions on a Hilbert space, then for any polynomial p in two variables, ‖p(T1,T2)‖≤‖p‖D2, where D2 is the bidisk in C2. The main goal of the present paper is to find analogues of Ando's results for the elements of the bi-ball Pn1,n2 which consists of all pairs (X,Y) of row contractions X:=(X1,…,Xn1) and Y:=(Y1,…,Yn2) which commute, i.e. each entry of X commutes with each entry of Y. The results are obtained in a more general setting, namely, when X and Y belong to noncommutative varieties V1 and V2 determined by row contractions subject to constraints such as q(X1,…,Xn1)=0andr(Y1,…,Yn2)=0,q∈P,r∈R, respectively, where P and R are sets of noncommutative polynomials. We obtain dilation results which simultaneously generalize Sz.-Nagy dilation theorem for contractions, Ando's dilation theorem for commuting contractions, Sz.-Nagy–Foias commutant lifting theorem, and Schur's representation for the unit ball of H∞, in the framework of noncommutative varieties and Poisson kernels on Fock spaces. This leads to one of the main results of the paper, an Ando type inequality on noncommutative varieties, which, in the particular case when n1=n2=1 and T1 and T2 are commuting contractive matrices with spectrum in the open unit disk D:={z∈C:|z|<1}, takes the form ‖p(T1,T2)‖≤min⁡{‖p(B1⊗ICd1,φ1(B1))‖,‖p(φ2(B2),B2⊗ICd2)‖}, where (B1⊗ICd1,φ1(B1)) and (φ2(B2),B2⊗ICd2) are analytic dilations of (T1,T2) while B1 and B2 are the universal models associated with T1 and T2, respectively. In this setting, the inequality is sharper than Ando's inequality and Agler–McCarthy's inequality. We obtain more general inequalities for arbitrary commuting contractive matrices and improve Ando's inequality for commuting contractions when at least one of them is of class C0. We prove that there is a universal model (S⊗Il2,φ(S)), where S is the unilateral shift and φ(S) is an isometric analytic Toeplitz operator on H2(D)⊗l2, such that ‖[prs(T1,T2)]k‖≤‖[prs(S⊗Il2,φ(S))]k‖, for any commuting contractions T1 and T2 on Hilbert spaces, any k×k matrix [prs]k of polynomials in C[z,w], and any k∈N. Analogues of this result for the bi-ball Pn1,n2 and for a class of noncommutative varieties are also considered.
On the Hardness of SAT with Community Structure

Recent attempts to explain the effectiveness of Boolean satisfiability (\(\mathsf {SAT}\)) solvers based on conflict-driven clause learning (CDCL) on large industrial benchmarks have focused on the concept of community structure. Specifically, industrial benchmarks have been empirically found to have good community structure, and experiments seem to show a correlation between such structure and the efficiency of CDCL. However, in this paper we establish hardness results suggesting that community structure is not sufficient to explain the success of CDCL in practice. First, we formally characterize a property shared by a wide class of metrics capturing community structure, including “modularity”. Next, we show that the \(\mathsf {SAT}\) instances with good community structure according to any metric with this property are still \(\mathsf {NP}\)-hard. Finally, we also prove that with high probability, random unsatisfiable modular instances generated from the “pseudo-industrial” community attachment model of Giraldez-Cru and Levy have exponentially long resolution proofs. Such instances are therefore hard for CDCL on average, indicating that actual industrial instances easily solved by CDCL may have some other relevant structure not captured by this model.
Where Chicagoans tweet the most: Semantic analysis of preferential return locations of Twitter users

Recent studies on human mobility show that human movements are not random and tend to be clustered. In this connection, the movements of Twitter users captured by geo-located tweets were found to follow similar patterns, where a few geographic locations dominate the tweeting activity of individual users. However, little is known about the semantics (landuse types) and temporal tweeting behavior at those frequently-visited locations. Furthermore, it is generally assumed that the top two visited locations for most of the users are home and work locales (Hypothesis A) and people tend to tweet at their top locations during a particular time of the day (Hypothesis B). In this paper, we tested these two frequently cited hypotheses by examining the tweeting patterns of more than 164,000 unique Twitter users whom were residents of the city of Chicago during 2014. We extracted landuse attributes for each geo-located tweet from the detailed inventory of the Chicago Metropolitan Agency for Planning. Top-visited locations were identified by clustering semantic enriched tweets using a DBSCAN algorithm. Our results showed that although the top two locations are likely to be residential and occupational/educational, a portion of the users deviated from this case, suggesting that the first hypothesis oversimplify real-world situations. However, our observations indicated that people tweet at specific times and these temporal signatures are dependent on landuse types. We further discuss the implication of confounding variables, such as clustering algorithm parameters and relative accuracy of tweet coordinates, which are critical factors in any experimental design involving Twitter data.
List-Coloring the Squares of Planar Graphs without 4-Cycles and 5-Cycles

Let G be a planar graph without 4-cycles and 5-cycles and with maximum degree Δi¾ź32. We prove that i¾źi¾źG2i¾źΔ+3. For arbitrarily large maximum degree Δ, there exist planar graphs GΔ of girth 6 with i¾źGΔ2=Δ+2. Thus, our bound is within 1 of being optimal. Further, our bound comes from coloring greedily in a good order, so the bound immediately extends to online list-coloring. In addition, we prove bounds for Lp,q-labeling. Specifically, λ2,1Gi¾źΔ+8 and, more generally, λp,qGi¾ź2q-1Δ+6p-2q-2, for positive integers p and q with pi¾źq. Again, these bounds come from a greedy coloring, so they immediately extend to the list-coloring and online list-coloring variants of this problem.
Karen Refugees Describe Peace within the Context of Displacement

Displaced populations are often the most vulnerable and at-risk people in our world today. Many end up becoming victims of human smuggling and trafficking, and they are often subjected to intolerable living conditions and uncertainty regarding their future. What can displaced populations teach us about peace? Using a storytelling method, Karen refugees along the Thai-Burmese border describe peace as encompassing, embodying quality of life, both social and personal. It comprises an interdisciplinary spectrum of socioeconomic, political, psychosocial, and educational elements. Peace for Karen refugees requires a collaborative action among government and nongovernment organizations.
Determination of Polystyrene in GR-S Rubber

A convenient procedure for the determination of polystyrene in GR-S is given. The method depends upon degradation of the GR-S by tert-butyl hydroperoxide in the presence of a trace of osmium tetroxide. Polystyrene is not attacked and is separated by precipitation with ethanol.
Multifocal Atrial Tachycardia

Abstract Multifocal atrial tachycardia was seen in 32 elderly and severely ill patients, with a high prevalence of acute and chronic pulmonary disease and cor pulmonale. Twelve patients (37.5 per cent) died. Bronchodilators were used frequently and contributed to the rapid heart rates. The arrhythmia itself was rarely due to digitalis intoxication. Serious arrhythmias did not arise in patients receiving maintenance doses of digitalis. Increments of digitalis often produced high-grade atrioventricular block, atrial tachycardia with block, nodal rhythms and ventricular irritability. Multifocal atrial tachycardia should be carefully distinguished from other atrial arrhythmias, especially atrial fibrillation. This is particularly important for rational digitalis therapy. Control of the arrhythmia paralleled improvement in ventilation and oxygenation, control of sepsis, correction of metabolic and electrolyte derangements and reduction in chronotropic drugs used as bronchodilators. The role of antiarrhythmic a...
The structure of water-saturated carbonate melts

The structure of water-saturated Ca- and Mg-bearing carbonate melts under reducing and oxidizing conditions was investigated in a series of hydrothermal anvil cell experiments conducted at 400–1100 °C and 442–2839 MPa. Equilibria were investigated in the calcite-H 2 O, calcite-CaO-H 2 O, magnesite-H 2 O, and magnesite-MgO-H 2 O systems, with redox conditions controlled by Re/ReO 2 and Ti/TiO 2 assemblages. Melting relationships and the C-O-H speciation of the coexisting aqueous fluid and melt were assessed in situ by Raman vibrational spectroscopy. Hydrous melting of MgCO 3 -MgO occurred at ~850 °C, 1.5–2 GPa. In the CaCO 3 -CaO-H 2 O system, melt was formed at 600–900 °C and pressures of 0.5–1.5 GPa because of melting-point depression imposed by the presence of CaO. The C-O-H speciation of the carbonate melts and coexisting supercritical aqueous solutions was mainly H 2 O and CO 3 2− , with traces of CO 2(aq) and CH 4(aq) in the fluid phase. The melt-fluid H 2 O partition coefficients attained in the Mg-bearing melt (median 0.5) were higher than in the Ca-bearing melt (median 0.3). Under oxidizing redox conditions, dissolved ReO 2 − was present in all phases, underscoring the enhanced solubility of metals in carbonate-bearing melts and carbonatites. In effect, the enhanced solubility of H 2 O along with the ionic nature of the carbonate melts may promote the solvation of ionic species in the melt structure. From in situ vibrational spectroscopy, the v 1 -CO 3 2− vibration recorded in the melt spectra suggests the presence of intermolecular interactions between the oxygen of the carbonate ion with water dissolved in the melt. The thermodynamic properties of this water appear to be similar to the supercritical aqueous phase. For example, the estimated enthalpy for the breakage of the hydrogen bonding between water molecules attained values of 6.8 ± 1.5 kcal/mol and 8.4 ± 1.3 kcal/mol in the melt and fluid phase, respectively. The calculated partial molar volume of H 2 O in the melt (~48 ± 6 cm 3 /mol) is also comparable to the partial molar volume of supercritical water at similar conditions. Interestingly, this value is considerably greater than published partial molar volume values for H 2 O in silicate melts (10–12 cm 3 /mol). The pressure-temperature melting relationships of the CaO-CO 2 -H 2 O and MgO-CO 2 -H 2 O systems highlight the important role of water and alkaline earth oxides on the hydrous melting of the carbonate-bearing subducting oceanic crust. Carbonates present in marine sediments or serpentinized peridotites may melt before complete dehydration at the slab-mantle wedge transition zone, and thus, never reach sub-arc depths. To this end, melting of carbonate minerals at crustal temperatures and pressure can contribute to the volcanic CO 2 flux at the arc through melt/fluid interactions.
Competitiveness, convergence, and international specialization

David Dollar and Edward Wolff look at claims that a deindustrialized United States is on the road to secondrate status in the global marketplace and find them to be both unfounded and simplistic. Their systematic and empirical investigation of the mechanisms through which countries like Japan and Germany have caught up with the United States in terms of productivity and standard of living will inform public debate about which government policies are likely to improve a nation's competitiveness.Looking at productivity convergence from the industry and subindustry level, Dollar and Wolff also examine questions of the relationship of productivity growth in individual industries to convergence of overall productivity in developed countries, the identification of industries crucial for aggregate productivity growth, the sources of productivity growth within industries, the relationship between international trade and productivity convergence, and whether the same mechanics of convergence are at work in developing countries.The authors' findings reveal, among other things, that the slowness of U.S. productivity growth relative to other nations is largely due to forces pushing for convergence of aggregate productivity levels. Although other countries have been catching up with the U.S., there is no evidence that they will surpass the US. or that the U.S. has deindustrialized.Perhaps most important, Dollar and Wolff find that countries catch up by raising their productivity levels in all manufacturing industries, not by large shifts of their employment and output from low- to high-value-added sectors. The growing similarity of advanced economies in terms of overall productivity masks a continued high degree of specialization in particular industries. Today different countries are the productivity leaders in different industries. Accordingly, the authors recommend that public policy focus on institutions and policies to promote innovation in general, rather than in key industries, and on free trade rather than protectionism.David Dollar is Senior Economist at the World Bank. Edward N. Wolff is Professor of Economics at New York University.
The Role of Neoadjuvant Chemotherapy in the Management of Patients With Advanced Stage Ovarian Cancer: Survey Results From Members of the Society of Gynecologic Oncologists

•NACT use among SGO members for ovarian cancer is explored given recent trials.•Fewer SGO members feel they can't predict optimal cytoreduction pre-operatively.•Laparoscopy use has increased both for diagnosis and treatment of ovarian cancer.•Very high optimal cytoreduction rates are reported from SGO members.•Despite recent studies, SGO members don't regularly treat patients with NACT/ID.
Atomic-Scale Evidence for Potential Barriers and Strong Carrier Scattering at Graphene Grain Boundaries: A Scanning Tunneling Microscopy Study

We use scanning tunneling microscopy and spectroscopy to examine the electronic nature of grain boundaries (GBs) in polycrystalline graphene grown by chemical vapor deposition (CVD) on Cu foil and transferred to SiO2 substrates. We find no preferential orientation angle between grains, and the GBs are continuous across graphene wrinkles and SiO2 topography. Scanning tunneling spectroscopy shows enhanced empty states tunneling conductance for most of the GBs and a shift toward more n-type behavior compared to the bulk of the graphene. We also observe standing wave patterns adjacent to GBs propagating in a zigzag direction with a decay length of ∼1 nm. Fourier analysis of these patterns indicates that backscattering and intervalley scattering are the dominant mechanisms responsible for the mobility reduction in the presence of GBs in CVD-grown graphene.
Nickel(0)-Catalyzed Heck Cross-Coupling via Activation of Aryl C–OPiv Bonds

Using a Ni(dppf) catalyst generated in situ, Heck cross-coupling of aryl pivalates with a variety of olefin partners has been accomplished. This method represents one of the first examples of a C–C cross-coupling via activation of a strong C–O bond with a nonorganometallic coupling partner. It enables the transformation of phenol-based substrates into styrenyl products without generation of a halogenated byproduct or the use of expensive triflate groups.
Regioselective Silyl/Acetate Exchange of Disaccharides Yields Advanced Glycosyl Donor and Acceptor Precursors

Glycoconjugates are composed of carbohydrate building blocks linked together in a multitude of ways giving rise to diverse biological functions. Carbohydrates are especially difficult to synthetically manipulate because of the similar reactivity of their numerous and largely equivalent hydroxyl groups. Hence, methodologies for both the efficient protection and selective modification of carbohydrate alcohols are considered important synthetic tools in organic chemistry. When per-O-TMS protected mono- or disaccharides in a mixture of pyridine and acetic anhydride are treated with acetic acid, regioselective exchange of silicon for acetate protecting groups occurs. Acid concentration, thermal conditions, and microwave assistance mediate the silyl/acetate exchange reaction. Regiocontrol is achieved by limiting the equivalents of acetic acid, and microwave irradiation hastens the process. We coined the term Regioselective Silyl Exchange Technology (ReSET) to describe this process, which essentially sets the pr...
Recent Advances in Avalanche Photodiodes

Until the early 2000's, the avalanche photodiode (APD) was widely deployed in high-performance optical receivers that operated up to 10 Gb/s. In subsequent years, the use of APDs for high-capacity systems declined as a result of their limited gain bandwidth, the transition to coherent detection, and the development of high-efficiency modulation techniques. Recently, the rapid growth of optical-fiber communications systems that utilize baud rates up to 25 Gb/s represented by a 100-Gb/s Ethernet has led to a resurgence of research on APDs and the development of low-noise APDs with enhanced gain bandwidth. This paper presents a brief review of APD fundamentals and describes some of the recent advances.
An Integrated Circuit for Radio Astronomy Correlators Supporting Large Arrays of Antennas

Radio telescopes that employ arrays of many antennas are in operation, and ever larger ones are being designed and proposed. Signals from the antennas are combined by cross-correlation. While the cost of most components of the telescope is proportional to the number of antennas N, the cost and power consumption of cross-correlationare proportional to N2 and dominate at sufficiently large N. Here we report the design of an integrated circuit (IC) that performs digital cross-correlations for arbitrarily many antennas in a power-efficient way. It uses an intrinsically low-power architecture in which the movement of data between devices is minimized. In a large system, each IC performs correlations for all pairs of antennas but for a portion of the telescope's bandwidth (the so-called "FX" structure). In our design, the correlations are performed in an array of 4096 complex multiply-accumulate (CMAC) units. This is sufficient to perform all correlations in parallel for 64 signals (N=32 antennas with 2 opposite-polarization signals per antenna). When N is larger, the input data are buffered in an on-chipmemory and the CMACs are re-used as many times as needed to compute all correlations. The design has been synthesized and simulated so as to obtain accurate estimates of the IC's size and power consumption. It isintended for fabrication in a 32 nm silicon-on-insulator process, where it will require less than 12mm2 of silicon area and achieve an energy efficiency of 1.76 to 3.3 pJ per CMAC operation, depending on the number of antennas. Operation has been analyzed in detail up to N = 4096. The system-level energy efficiency, including board-levelI/O, power supplies, and controls, is expected to be 5 to 7 pJ per CMAC operation. Existing correlators for the JVLA (N = 32) and ALMA (N = 64) telescopes achieve about 5000 pJ and 1000 pJ respectively usingapplication-specific ICs in older technologies. To our knowledge, the largest-N existing correlator is LEDA atN = 256; it uses GPUs built in 28 nm technology and achieves about 1000 pJ. Correlators being designed for the SKA telescopes (N = 128 and N = 512) using FPGAs in 16nm technology are predicted to achieve about 100 pJ.
Social Groups Prioritize Selective Attention to Faces: How Social Identity Shapes Distractor Interference.

Human faces automatically attract visual attention and this process appears to be guided by social group memberships. In two experiments, we examined how social groups guide selective attention toward in-group and out-group faces. Black and White participants detected a target letter among letter strings superimposed on faces (Experiment 1). White participants were less accurate on trials with racial out-group (Black) compared to in-group (White) distractor faces. Likewise, Black participants were less accurate on trials with racial out-group (White) compared to in-group (Black) distractor faces. However, this pattern of out-group bias was only evident under high perceptual load—when the task was visually difficult. To examine the malleability of this pattern of racial bias, a separate sample of participants were assigned to mixed-race minimal groups (Experiment 2). Participants assigned to groups were less accurate on trials with their minimal in-group members compared to minimal out-group distractor faces, regardless of race. Again, this pattern of out-group bias was only evident under high perceptual load. Taken together, these results suggest that social identity guides selective attention toward motivationally relevant social groups—shifting from out-group bias in the domain of race to in-group bias in the domain of minimal groups—when perceptual resources are scarce.
Microbial interactions and community assembly at microscales

In most environments, microbial interactions take place within microscale cell aggregates. At the scale of these aggregates (∼100μm), interactions are likely to be the dominant driver of population structure and dynamics. In particular, organisms that exploit interspecific interactions to increase ecological performance often co-aggregate. Conversely, organisms that antagonize each other will tend to spatially segregate, creating distinct micro-communities and increased diversity at larger length scales. We argue that, in order to understand the role that biological interactions play in microbial community function, it is necessary to study microscale spatial organization with enough throughput to measure statistical associations between taxa and possible alternative community states. We conclude by proposing strategies to tackle this challenge.
Triplication of the Ureter

Case history An eight-year-old girl was referred for intravenous pyelography because of repeated bouts of urinary tract infection. These episodes were associated with frequency, fever and chills. There was no incontinence or flank pain. The patient was of average height and weight for her age. Physical findings were within normal limits. Pertinent laboratory results were limited to the urinary findings where 30-40 W.B.C. per centrifuged high power field were noted and cultures yielded abundant growth of E. coli. An intravenous pyelogram revealed complete triplication on the left (Fig. 1). There were no radiographic findings of chronic pyelonephritis or other abnormality. A cystoscopic examination was subsequently performed and revealed three separate left ureteral orifices within the bladder. The patient was treated with appropriate antibiotics for one
Comparison of metal-hydrogen, -oxygen, -nitrogen and -carbon bond strengths and evaluation of functional group additivity principles for organoruthenium and organoplatinum compounds

Abstract The equilibria: LnMX + HY ⇁ LnMY + HX (LnM = (DPPE)MePt or Cp(PMe3)2Ru; X, Y = hydride, alkoxide, hydroxide, amide, alkyl, alkynyl, hydrosulphide, cyanide) have been examined. The equilibrium constants allow for the determination of relative MX, MY bond dissociation energies (BDEs) for each series of compounds. A linear correlation of LnMX to HX BDEs is found for the two dissimilar metal centres. Activation barriers for phosphine dissociation from Cp(PMe3)2RuX complexes have been measured and suggest the principle of functional group additivity has limited applicability in organometallic thermochemistry. The generality and predictive value of this correlation and the observations on functional group additivity are discussed.
Pathway to oxide photovoltaics via band-structure engineering of SnO

All-oxide photovoltaics could open rapidly scalable manufacturing routes, if only oxide materials with suitable electronic and optical properties were developed. SnO has exceptional doping and transport properties among oxides, but suffers from a strongly indirect band gap. Here, we address this shortcoming by band-structure engineering through isovalent but heterostructural alloying with divalent cations (Mg, Ca, Sr, and Zn). Using first-principles calculations, we show that suitable band gaps and optical properties close to that of direct semiconductors are achievable, while the comparatively small effective masses are preserved in the alloys. Initial thin film synthesis and characterization support the feasibility of the approach.
Are mosquitoes gourmet or gourmand

Resume des contributions scientifiques de B.Hocking, en particulier ses ecrits sur la specificite de l'hematophagie. Le comportement de recherche de l'hote par les moustiques et le succes de la prise de nourriture sont discutees.
Superradiance in spherical layered nanostructures

We propose a design of a spherically symmetric nanostructure consisting of alternate concentric semiconductor and dielectric layers. The exciton states in different semiconductor layers of such a structure interact via the common electromagnetic field of light. We show that, if the exciton states in $N$ semiconductor layers are in resonance with one another, then a superradiant state emerges under optical excitation of such a structure. We discuss the conditions under which superradiance can be observed and show that they strongly depend on the valence-band structure of the semiconductor layers.
Pilot Randomized Trial of Active Music Engagement Intervention Parent Delivery for Young Children With Cancer

Objectives To examine the feasibility/acceptability of a parent-delivered Active Music Engagement (AME + P) intervention for young children with cancer and their parents. Secondary aim to explore changes in AME + P child emotional distress (facial affect) and parent emotional distress (mood; traumatic stress symptoms) relative to controls. Methods A pilot two-group randomized trial was conducted with parents/children (ages 3-8 years) receiving AME + P ( n = 9) or attention control ( n = 7). Feasibility of parent delivery was assessed using a delivery checklist and child engagement; acceptability through parent interviews; preliminary outcomes at baseline, postintervention, 30 days postintervention. Results Parent delivery was feasible, as they successfully delivered AME activities, but interviews indicated parent delivery was not acceptable to parents. Emotional distress was lower for AME + P children, but parents derived no benefit. Conclusions Despite child benefit, findings do not support parent delivery of AME + P.
Screening for type 2 diabetes mellitus in adults: recommendations and rationale.

This statement summarizes the current U.S. Preventive Services Task Force (USPSTF) recommendations on screening for type 2 diabetes in adults and updates the 1996 recommendations on this topic. The complete USPSTF recommendation and rationale statement on this topic, which includes a brief review of the supporting evidence, is available through the USPSTF Web site ( http://www.preventiveservices.ahrq.gov ) and the National Guideline Clearinghouse ( http://www.guideline.gov ) and in print through the Agency for Healthcare Research and Quality (AHRQ) Publications Clearinghouse (call 800-358-9295 or e-mail mailto:ahrqpubs@ahrq.gov ). The complete information on which this statement is based, including evidence tables and references, is available in the accompanying article in this issue and in the summary of the evidence and systematic evidence review on this topic on the Web sites already mentioned. The summary of the evidence is also available in print through the AHRQ Publications Clearinghouse.
Modern advances in heterocyclic chemistry in drug discovery

New advances in synthetic methodologies that allow rapid access to a wide variety of functionalized heterocyclic compounds are of critical importance to the medicinal chemist as it provides the ability to expand the available drug-like chemical space and drive more efficient delivery of drug discovery programs. Furthermore, the development of robust synthetic routes that can readily generate bulk quantities of a desired compound help to accelerate the drug development process. While established synthetic methodologies are commonly utilized during the course of a drug discovery program, the development of innovative heterocyclic syntheses that allow for different bond forming strategies are having a significant impact in the pharmaceutical industry. This review will focus on recent applications of new methodologies in C–H activation, photoredox chemistry, borrowing hydrogen catalysis, multicomponent reactions, regio- and stereoselective syntheses, as well as other new, innovative general syntheses for the formation and functionalization of heterocycles that have helped drive project delivery. Additionally, the importance and value of collaborations between industry and academia in shaping the development of innovative synthetic approaches to functionalized heterocycles that are of greatest interest to the pharmaceutical industry will be highlighted.
Fetal sacrococcygeal teratoma

The fetus with sacrococcygeal teratoma (SCT) is at high risk for prenatal and perinatal complications. The natural history and pathophysiology of fetal SCT is different than that of postnatally diagnosed SCT, and has only recently been defined. Survival of fetuses with SCT is dependent on anticipation and recognition of pathophysiologic events, and optimal obstetric and surgical management. In a subset of fetuses with SCT, fetal resection of tumor may offer the only hope for survival.
Stereoselection in Intramolecular Diels-Alder Reactions of 2-Cyano-1-azadienes: Indolizidine and Quinolizidine Synthesis.

Progress toward understanding the scope and diastereoselectivity of intramolecular Diels–Alder reactions using 2-cyano-1-azadienes is described herein. The resulting cyanoenamine products are underutilized intermediates in organic synthesis. Assembly of the Diels–Alder precursors was achieved using an improved imine condensation/oxidative cyanation protocol. By this method, several highly substituted indolizidine and quinolizidine architectures were constructed. Quantum mechanical DFT calculations at the B3LYP/6-31+G(d) level of theory were performed for these cyclizations and provide insights into the origins of the observed diastereoselectivities.