cssi/SciSciGPT-SciSciNet huggingface dataset:
Self-Phase Modulation Compensation in a Regenerative Amplifier Using Cascaded Second-Order Nonlinearities

Cascaded nonlinearities are theoretically and experimentally investigated for intracavity nonlinearity compensation in a Nd:YLF regenerative amplifier. Spectral broadening is significantly reduced, in agreement with simulations, allowing for efficient amplification in a Nd:YLF power amplifier.
Solvent-dependent divergent functions of Sc(OTf)3 in stereoselective epoxide-opening spiroketalizations

A stereocontrolled synthesis of benzannulated spiroketals has been developed using solvent-dependent Sc(OTf)3-mediated spirocyclizations of exo-glycal epoxides having alcohol side chains. In THF, the reaction proceeds via Lewis acid catalysis under kinetic control with inversion of configuration at the anomeric carbon. In contrast, in CH2Cl2, Bronsted acid catalysis under thermodynamic control leads to retention of configuration. The reactions accommodate a variety of aryl substituents and ring sizes and provide stereochemically diverse spiroketals.
Total Synthesis, Stereochemical Assignment, and Biological Activity of All Known (−)-Trigonoliimines

A full account of our concise and enantioselective total syntheses of all known (−)-trigonoliimine alkaloids is described. Our retrobiosynthetic analysis of these natural products enabled identification of a single bistryptamine precursor as a precursor to all known trigonoliimines through a sequence of transformations involving asymmetric oxidation and reorganization. Our enantioselective syntheses of these alkaloids enabled the revision of the absolute stereochemistry of (−)-trigonoliimines A, B, and C. We report that trigonoliimines A, B, C and structurally related compounds showed weak anticancer activities against HeLa and U-937 cells.
Specific Treatment of the Pneumococcic Pneumonias; An Analysis of the Results of Serum Therapy and Chemotherapy at the Boston City Hospital from July 1938 through June 1939

Excerpt During the past few months, in accord with the general trend in the treatment of bacterial infections, the focus of attention in the literature dealing with the therapy of pneumonia has shi...
Speeding Up Sigmatropic Shifts-To Halve or to Hold.

ConspectusCatalysis is common. Rational catalyst design, however, is at the frontier of chemical science. Although the histories of physical organic and synthetic organic chemistry boast key chapters involving [3s,3s] sigmatropic shifts, catalysis of these reactions is much less common than catalysis of ostensibly more complex processes. The comparative dearth of catalysts for sigmatropic shifts is perhaps a result of the perception that transition state structures for these reactions, like their reactants, are nonpolar and therefore not amenable to selective stabilization and its associated barrier lowering. However, as demonstrated in this Account, transition state structures for [3s,3s] sigmatropic shifts can in fact have charge distributions that differ significantly from those of reactants, even for hydrocarbon substrates, allowing for barriers to be decreased and rates increased. In some cases, differences in charge distribution result from the inclusion of heteroatoms at specific positions in react...
The Effects of Public Information with Asymmetrically Informed Short-Horizon Investors

This paper analyzes the effects of public information in a perfect competition trading model populated by asymmetrically informed short-horizon investors with different levels of private information precision. We first show that information asymmetry reduces the amount of private information revealed by price in equilibrium (i.e., price informativeness) and can lead to multiple linear equilibria. We then demonstrate that the presence of both information asymmetry and short horizons provides a channel through which public information influences price informativeness and equilibrium uniqueness. We identify conditions under which public information increases or decreases price informativeness, and when multiple equilibria may arise. Our analysis shows that public information not only directly endows prices with more (public) information, it can also have an important indirect effect on the degree to which prices reveal private information.
Inflation and Compression of Rubber Tubes between Parallel Plates

Abstract When a thin-walled rubber tube containing an incompressible fluid is compressed between two parallel plates the internal pressure rise depends on the restraints in the contact regions. When there is no friction in the contact zone the pressure rise is lower than when slip is prevented, so that the tube, regarded as a spring, has a compression stiffness which depends on the frictional conditions. The same considerations apply to the inflation of a tube between fixed parallel plates. In this case unstable inflation sets in at a critical pressure when the interfaces are frictionless; the tube develops a pronounced bulge when this pressure is approached. Simple theoretical relations are derived for the internal pressure and compressive force for both these deformations, and for both boundary conditions, assuming that the rubber is neo-Hookean in elastic behavior. Experimental measurements on tubes of different dimensions are shown to be in reasonably good quantitative agreement with these theoretical...
Visible Photoluminescence and Microstructure of Annealed and Chemically Etched Amorphous Si

We have studied the visible photoluminescence (PL) and microstructure of porous Si layers (PSLs) fabricated by the chemical etching of annealed amorphous Si (a-Si). The a-Si layers were partially crystallized by annealing between 550°C-1150°C in N2 and the PSL formed by etching in a HF-HNO3-based solution. No visible PL was observed after etching of unannealed a-Si. Visible PL was detected after etching a-Si layers first annealed at temperatures ≥725°C, coinciding with the observation of Si microcrystallites in the annealed layer prior to etching. The results suggest that an initial crystalline structure is important for fabricating luminescent PSLs.
Stereoselective synthesis of quaternary carbons via the dianionic Ireland-Claisen rearrangement.

A dianionic Ireland–Claisen rearrangement of chiral, nonracemic α-methyl-β-hydroxy allylic esters has been developed that proceeds with high diastereoselectivity and provides products containing three contiguous stereogenic carbons, including a quaternary center. The potential utility of the rearrangement for complex molecule synthesis is also demonstrated.
An Umpolung Strategy for the Synthesis of β-Aminoketones via Copper-Catalyzed Electrophilic Amination of Cyclopropanols

A novel copper-catalyzed electrophilic amination of cyclopropanols with O-benzoyl-N,N-dialkylhydroxylamines to synthesize various β-aminoketones via a sequence that includes C–C bond cleavage and Csp3–N bond formation is reported. The reaction conditions are mild and tolerate a wide range of functional groups including benzoate, tosylate, expoxide, and α,β-unsaturated carbonyls, which are incompatible in the traditional amine nucleophilic conjugate addition and the Mannich reaction conditions. Preliminary mechanistic studies and a proposed catalytic cycle of this umpolung β-aminoketone synthesis process have been described as well.
Enantioselective A3 Reactions of Secondary Amines with a Cu(I)/Acid–Thiourea Catalyst Combination

Pyrrolidine and related amines undergo asymmetric A3 reactions in the presence of copper iodide and an easily accessible cocatalyst possessing both a carboxylic acid and a thiourea moiety. Propargylamines are obtained with up to 96% ee, and catalyst loadings can be as low as 1 mol %. Pyrrolidine-derived propargylamines, in the absence of directing groups, can be transformed to the corresponding allenes without loss of enantiopurity.
Knowledge will set you free: Enhancing the firm’s responsiveness to institutional change

Purpose – The purpose of this paper is to combine notions from the POST Model of Economic Geography and Learning Theory from International Business to study how firms may enhance their responsiveness to institutional processes and changes through different forms of international learning. Focussing on one form of institutional changes, namely pro-market reforms, the paper analyzes how firms may boost the potential benefits from such changes through international strategies that increase their access to knowledge spillovers and absorptive capacity. These strategies include international product diversification, enhancing innovation capabilities, informal institutional exposure, accumulated internationalization knowledge, and overall experiential knowledge. Design/methodology/approach – The hypotheses are tested using generalized least squares models with AR(1) panel-specific autocorrelation and heteroskedasticity correction. Based on the preliminary analyses performed in these studies, the author also exec...
Thoracolumbar Burst Fractures: CT Dimensions of the Spinal Canal Relative to Postsurgical Improvement

Cross-sectional spinal canal area was measured before and after surgery in 12 patients with thoracolumbar burst fractures and canal narrowing caused by retropulsed fragments, Patients were classified into Denis type A or type B. Denis type A fractures have comminution of both end-plates of the vertebral body creating multiple smaller fractures; Denis type B fractures have comminution of the superior end-plate only with a single vertical fracture line into the inferior end-plate creating larger fragments. The degree of neurologic impairment was assessed before and after surgery using the Frankel system. There was no correlation between degree of canal narrowing and degree of neurologic impairment. The degree of spinal canal narrowing reflects the final resting position of the vertebral body fragments after trauma; during trauma, greater degrees of canal impingement may have occurred. Also, significant canal narrowing may be present without pinching of the cord or cauda equina. All patients with Denis type A fractures had near-anatomic reduction of fragments out of the spinal canal by surgery; less than half of the patients with Denis type B had good reduction. There was no correlation between reduction of retropulsed fragments and subsequent neurologic improvement. However, this should not preclude surgery as a therapeutic option: Eight of 10 patients with neurologic impairment experienced some improvement in symptoms after surgery; the other two were unchanged.
Between a Rock and a Hard Place: Can Physicians Prescribe Opioids to Treat Pain Adequately While Avoiding Legal Sanction?

Prescription opioids are an important tool for physicians in treating pain but also carry significant risks of harm when prescribed inappropriately or misused by patients or others. Recent increases in opioid-related morbidity and mortality has reignited scrutiny of prescribing practices by law enforcement, regulatory agencies, and state medical boards. At the same time, the predominant 4D model of misprescribers is outdated and insufficient; it groups physician misprescribers as dated, duped, disabled, or dishonest. The weaknesses and inaccuracies of the 4D model are explored, along with the serious consequences of its application. This Article calls for development of an evidence base in this area and suggests an alternate model of misprescribers, the 3C model, which more accurately characterizes misprescribers as careless, corrupt, or compromised by impairment.
Selection and explosive growth alter genetic architecture and hamper the detection of causal rare variants

The role of rare alleles in complex phenotypes has been hotly debated, but most rare variant association tests (RVATs) do not account for the evolutionary forces that affect genetic architecture. Here, we use simulation and numerical algorithms to show that explosive population growth, as experienced by human populations, can dramatically increase the impact of very rare alleles on trait variance. We then assess the ability of RVATs to detect causal loci using simulations and human RNA-seq data. Surprisingly, we find that statistical performance is worst for phenotypes in which genetic variance is due mainly to rare alleles, and explosive population growth decreases power. Although many studies have attempted to identify causal rare variants, few have reported novel associations. This has sometimes been interpreted to mean that rare variants make negligible contributions to complex trait heritability. Our work shows that RVATs are not robust to realistic human evolutionary forces, so general conclusions about the impact of rare variants on complex traits may be premature.
Taurine transport by microvillous membrane vesicles and the perfused cotyledon of the human placenta

Human placental uptake and maternal-to-fetal (M-to-F) net transfer of taurine were evaluated in purified microvillous membrane vesicles (MMV) and the isolated perfused cotyledon. Taurine uptake by MMV was specifically stimulated by an inward Na+ gradient [maximum velocity (Vmax), 24.5 +/- 0.6 pmol.mg-1.30 s-1; Michaelis constant (Km), 6.2 +/- 0.7 microM], with uptake stoichiometry showing approximately 2 Na+/taurine molecule. In the presence or absence of Na+, Cl- did not stimulate uptake. Na(+)-stimulated uptake was enhanced by an outward K+ gradient. beta-Alanine and hypotaurine competitively inhibited uptake of taurine in MMV. Two-way uptake inhibition studies showed no interaction between taurine and non-beta-amino acids. When MMV were preloaded with taurine there was enhancement of Na(+)-stimulated uptake. In the perfused placentas, saturable M-to-F net transfer of taurine was not observed, despite saturation of tissue uptake from the maternal circulation. During 3 h of perfusion, no fetal-to-maternal (F-to-M) gradient formed for taurine; yet, a 2:1 gradient simultaneously occurred for histidine. This study demonstrates that taurine uptake by the microvillous membrane of the human placenta is highly specific, of high affinity, and Na+ coupled.
Expert system prototype of food aid distribution.

The aim of this study was to improve efficiency of the food aid distribution process of international food relief organizations. An overall objective of this study was to develop a prototype expert system for monitoring and evaluating food aid by international disaster relief organizations. The research identifies data related to monitoring and evaluation processes of various international food-aid organizations. It then applies an artificial intelligence-based expert system to develop a prototype for those processes. Existing data related to monitoring and evaluation program cycles were obtained. An expert system shell called CLIPS© (National Aeronautics Space Administration) was used to develop a prototype system named Food Aid Monitor, a rule-based expert system, which uses facts and heuristic rules to provide an adaptive feedback regarding monitoring and evaluating processes at various stages of food aid operation. The Food Aid Monitor was evaluated and validated by three expert panels checking the prototype system for completeness, relevancy, consistency, correctness, precision, and usability. Finally, the panels indicated a belief that the system could have an overall positive impact on the stages of monitoring and evaluating food aid processes of the food relief organizations.
Income Poverty and Multiple Deprivations in a High-Income Country: The Case of the United States

Objectives The objective of this study is to develop a measure of multiple deprivations for the United States that is similar to those used on the international stage as multidimensional poverty. The latter is understood broadly as a deprivation of well-being across multiple dimensions rather than purely as a lack of income or other financial resources. Methods Using Current Population Survey and American Community Survey data, this study develops a measure of the joint distribution of multiple deprivations in the United States, in other words, a measure of the extent to which different deprivations are experienced by the same individuals. Results The experience of multiple deprivations affects 15 percent of Americans. An estimated 17.1 million Americans, 5.5 percent of the population, experience multiple deprivations while they are not income poor. The odds of experiencing multiple deprivations are significantly higher for Hispanics, immigrants, and persons with disabilities. Conclusions Income poverty is not a reliable proxy to measure multiple deprivations. Further measurement efforts are needed on overlapping multiple deprivations in the United States as such measures can be used in policy evaluation and monitoring.
The Synthesis of Alkyl and (Hetero)aryl Sulfonamides From Sulfamoyl Inner Salts

An approach to the synthesis of sulfonamides from sulfamoyl inner salts and organometallic species is presented. A range of sulfamoyl carbamates, amines, and metals are explored. Primary, secondary, and tertiary alkyl-, aryl-, and heteroaryllitihium and magnesium nucleophiles were successful. This approach yields bench-stable intermediates and avoids many of the functional group incompatibilities, regioselectivity issues, and high-energy reagents generally associated with the synthesis of sulfonamides. Additionally, the products may be purified by basic extraction or salt formation, avoiding chromatography.
Myocardial Neovascularization by Adult Bone Marrow-Derived Angioblasts: Strategies for Improvement of Cardiomyocyte Function

In the pre-natal period, hemangioblasts derived from the human ventral aorta give rise to cellular elements involved in both hematopoiesis and vasculogenesis, resulting in formation of the primitive capillary network. Endothelial precursors with phenotypic and functional characteristics of embryonic hemangioblasts are also present in human adult bone marrow, and can be used to induce infarct bed vasculogenesis and angiogenesis after experimental myocardial infarction. The neovascularization results in decreased apoptosis of hypertrophied myocytes in the peri-infarct region, long-term salvage and survival of viable myocardium, reduction in collagen deposition, and sustained improvement in cardiac function. Autologous angioblasts may also be useful in cellular therapy strategies aiming to regenerate myocardial tissue after established heart failure. It is likely that protocols using cardiomyocyte/mesenchymal stem cells will require balanced co-administration of angioblasts to provide vascular structures for supply of oxygen and nutrients to both the chronically ischemic, endogenous myocardium and to the newly-implanted cardiomyocytes. Future studies will need to address the timing, relative concentrations, source and route of delivery of each of these cellular populations in animal models of acute and chronic myocardial ischemia.
One-pot synthesis of pyrroles using a titanium-catalyzed multicomponent coupling procedure

Abstract A simple one-pot procedure for the production of 2-carboxylpyrroles with 4-alkyl, 5-alkyl, 4-aryl, 4-aryl-5-alkyl, or 3,4-diaryl substitution patterns is presented. The procedure involves the titanium-catalyzed multicomponent coupling of alkynes, primary amines and isonitriles to give 1,3-diimines in situ; the multicomponent product is then treated with the ethyl ester of glycine hydrochloride to give the NH-pyrrole. The reaction can be carried out with the neutralized glycine ester or with the hydrochloride salt using DBU as a base. Yields of pyrrole based on starting alkyne varied from 25 to 65% over the one pot procedure, and in most cases only one regioisomer of the product is observed. Further, it is proposed that the regioselectivities of the reactions are a result of rate-determining ring closure after relatively fast transimination with glycine ethyl ester.
Dynamic ambidexterity: How innovators manage exploration and exploitation

Abstract Firms must excel at both exploration and exploitation to ensure long-term survival and prosperity. However, firms often have difficulties in doing so because they have to accommodate the contradictory logics of exploration and exploitation. This article examines the logics of exploration and exploitation, evaluates the difficulties of accommodating both logics, and identifies dynamic ambidexterity as a new way to overcome these difficulties. To achieve dynamic ambidexterity, firms need to support structural ambidexterity at the corporate level, contextual ambidexterity at the business-unit level, and sequential ambidexterity at the project level. I believe that the notion of dynamic ambidexterity and its managerial practices can help firms manage exploration and exploitation and ensure long-term survival and prosperity.
Plan for Closure of Old River

Project to maintain course of Mississippi River below Old River; it provides for construction of controlled diversion system north of Old River, completion of Mississippi River levee system, and closure dam in Old River adjacent to lock structure now under construction; main earth dam will be 1450 ft long, 99 ft high; details of design of structures, methods of construction, and aspects of hydraulics, settlement, and seepage.
State specific vibrational relaxation and dissociation models for nitrogen in shock wave regions

This work studies the interaction of the DSMC vibrational relaxation models and dissociation of molecular nitrogen at moderate Mach numbers where such processes are important. The total collision energy (TCE) and QCT models for the N2 dissociation reaction were considered and the dissociation from different N2 vibrational excited states was included in the simulations. It was found that the use of the QCT rates compared to the usual, TCE model gave a substantially higher degree of dissociation and smaller shock width due to the non-equilibrium distribution in the vibrational states.
Pointer networks

We introduce a new neural architecture to learn the conditional probability of an output sequence with elements that are discrete tokens corresponding to positions in an input sequence. Such problems cannot be trivially addressed by existent approaches such as sequence-to-sequence [1] and Neural Turing Machines [2], because the number of target classes in each step of the output depends on the length of the input, which is variable. Problems such as sorting variable sized sequences, and various combinatorial optimization problems belong to this class. Our model solves the problem of variable size output dictionaries using a recently proposed mechanism of neural attention. It differs from the previous attention attempts in that, instead of using attention to blend hidden units of an encoder to a context vector at each decoder step, it uses attention as a pointer to select a member of the input sequence as the output. We call this architecture a Pointer Net (Ptr-Net). We show Ptr-Nets can be used to learn approximate solutions to three challenging geometric problems - finding planar convex hulls, computing Delaunay triangulations, and the planar Travelling Salesman Problem - using training examples alone. Ptr-Nets not only improve over sequence-to-sequence with input attention, but also allow us to generalize to variable size output dictionaries. We show that the learnt models generalize beyond the maximum lengths they were trained on. We hope our results on these tasks will encourage a broader exploration of neural learning for discrete problems.
Standards for Waveform Metrology Based on Digital Techniques

Over the last decade the use of digital synthesis and sampling techniques for generating and measuring electrical waveforms has increased dramatically with the availability of improved digital-to-analog (D/A) and analog-to-digital (A/D) converters and related devices. With this evolution has come the need for physical laboratory standards and test methods to support the performance specifications of digital devices and the instruments in which they are used. This article describes the research and development at NIST of several laboratory standards and test systems that utilize "digital technology" for characterizing data converters and for implementing various waveform synthesis and sampling instruments.
An empirical analysis of on-demand ride sharing and traffic congestion

Sharing economy, which leverages information technology to re-distribute unused or underutilized assets to people who are willing to pay for the services, has received tremendous attention in the last few years. Its creative business model has disrupted many traditional industries (e.g., transportation, hotel) by fundamentally changing the mechanism to facilitate the matching of demand with supply in real time. In this research, we investigate how Uber, a peer-to-peer mobile ride-sharing platform, affects traffic congestion in the urban areas of the United States. Combining data from Uber and the Urban Mobility Report, we empirically examine whether and how the entry of Uber car services affect traffic congestion using a difference-in-difference framework. Findings from this research provide evidence on the potential effect of ride sharing services in the transportation industry, contributing to the understanding of the sharing economy and government policy decisions.
Electron correlation by polarization of interacting densities

Coulomb interactions that occur in electronic structure calculations are correlated by allowing basis function components of the interacting densities to polarize dynamically, thereby reducing the magnitude of the interaction. Exchange integrals of molecular orbitals are not correlated. The modified Coulomb interactions are used in single-determinant or configuration interaction calculations. The objective is to account for dynamical correlation effects without explicitly introducing higher spherical harmonic functions into the molecular orbital basis. Molecular orbital densities are decomposed into a distribution of spherical components that conserve the charge and each of the interacting components is considered as a two-electron wavefunction embedded in the system acted on by an average field Hamiltonian plus r12−1. A method of avoiding redundancy is described. Applications to atoms, negative ions, and molecules representing different types of bonding and spin states are discussed.
CoType: Joint Extraction of Typed Entities and Relations with Knowledge Bases

Extracting entities and relations for types of interest from text is important for understanding massive text corpora. Traditionally, systems of entity relation extraction have relied on human-annotated corpora for training and adopted an incremental pipeline. Such systems require additional human expertise to be ported to a new domain, and are vulnerable to errors cascading down the pipeline. In this paper, we investigate joint extraction of typed entities and relations with labeled data heuristically obtained from knowledge bases (i.e., distant supervision). As our algorithm for type labeling via distant supervision is context-agnostic, noisy training data poses unique challenges for the task. We propose a novel domain-independent framework, called CoType, that runs a data-driven text segmentation algorithm to extract entity mentions, and jointly embeds entity mentions, relation mentions, text features and type labels into two low-dimensional spaces (for entity and relation mentions respectively), where, in each space, objects whose types are close will also have similar representations. CoType, then using these learned embeddings, estimates the types of test (unlinkable) mentions. We formulate a joint optimization problem to learn embeddings from text corpora and knowledge bases, adopting a novel partial-label loss function for noisy labeled data and introducing an object "translation" function to capture the cross-constraints of entities and relations on each other. Experiments on three public datasets demonstrate the effectiveness of CoType across different domains (e.g., news, biomedical), with an average of 25% improvement in F1 score compared to the next best method.
An acquisition and analysis pipeline for scanning angle interference microscopy

We describe open source software and hardware tools for calibrating, acquiring, and analyzing images for scanning angle interference microscopy (SAIM) analysis. These tools make it possible for any user with a TIRF microscope equipped with a motorized illumination unit to generate reconstructed images with nanometer precision in the axial (z) direction and diffraction-limited resolution in the lateral (xy) plane.
Drag and Lift on Spheres within Cylindrical Tubes

Method for evaluating lift and drag forces that are exerted by moving fluid on spherical particle resting on bottom of cylindrical tube; experimental data presented show variation in lift and drag force with particle to pipe-diameter ratio and Reynolds number; it is concluded that for spheres near wall of tube lift force with magnitude comparable to that of drag force exists.
The Social Cost of Carbon Revisited

Abstract An estimate of the social cost of carbon (SCC) is crucial to climate policy. But how should we estimate the SCC? A common approach uses an integrated assessment model (IAM) to simulate time paths for the atmospheric CO2 concentration, its impact on temperature, and resulting reductions in GDP. I have argued that IAMs have deficiencies that make them poorly suited for this job, but what is the alternative? I present an approach to estimating an average SCC, which I argue can be a useful guide for policy. I rely on a survey of experts to elicit opinions regarding (1) probabilities of alternative economic outcomes of climate change, but not the causes of those outcomes; and (2) the reduction in emissions required to avert an extreme outcome, i.e., a large climate-induced reduction in GDP. The average SCC is the ratio of the present value of lost GDP from an extreme outcome to the total emission reduction needed to avert that outcome. I discuss the survey instrument, explain how experts were identified, and present results. I obtain SCC estimates of $200/mt or higher, but the variation across experts is large. Trimming outliers and focusing on experts who expressed a high degree of confidence in their answers yields lower SCCs, $80 to $100/mt, but still well above the IAM-based estimates used by the U.S. government.
Intertwining operators and vector-valued modular forms for minimal models

Using the language of vertex operator algebras (VOAs) and vector-valued modular forms we study the modular group representations and spaces of 1-point functions associated to intertwining operators for Virasoro minimal model VOAs. We examine all representations of dimension less than four associated to irreducible modules for minimal models, and determine when the kernel of these representations is a congruence or noncongruence subgroup of the modular group. Arithmetic criteria are given on the indexing of the irreducible modules for minimal models that imply the associated modular group representation has a noncongruence kernel, independent of the dimension of the representation. The algebraic structure of the spaces of 1-point functions for intertwining operators is also studied, via a comparison with the associated spaces of holomorphic vector-valued modular forms.
The fading American dream: Trends in absolute income mobility since 1940

The American dream promises that hard work and opportunity will lead to a better life. Although the specifics of what constitutes a better life vary from generation to generation, one constant is that children expect to do better—or at least to have a good chance at doing better—than their parents. Chetty et al. show that this dream did come true for children born in the middle of the 20th century, but only for half of children born in 1984 (see the Policy Forum by Katz and Krueger). A more even distribution of economic growth, rather than more growth, would allow more children to fulfill their dreams. Science , this issue p. [398][1]; see also p. [382][2] [1]: /lookup/doi/10.1126/science.aal4617 [2]: /lookup/doi/10.1126/science.aan3264
Coordinating locomotion and manipulation of a mobile manipulator

A mobile manipulator in this study is a manipulator mounted on a mobile platform. Assuming the end point of the manipulator is guided, e.g., by a human operator to follow an arbitrary trajectory, it is desirable that the mobile platform is able to move as to position the manipulator in certain preferred configurations. Since the motion of the manipulator is unknown a priori, the platform has to use the measured joint position information of the manipulator for its own motion planning. This paper presents a control algorithm for the platform so that the manipulator is always positioned at the preferred configurations measured by its manipulability. Simulation results are presented to illustrate the efficacy of the algorithm. The algorithm is also implemented and verified on a real mobile manipulator system. The use of the resulting algorithm in a number of applications is also discussed. >
Rehosting legacy test program sets from military ATE

This paper describes some of the key issues developers must address in a test program set (TPS) rehosting plan. Examples and success stories are used to describe the translation of three legacy test program sets onto modern board test equipment, thereby extending the useful life of fielded systems and preserving the considerable investment made in developing the TPSs.
Enhancing Li-Ion Battery Safety by Early Detection of Nascent Internal Shorts

Catastrophic failure concerns impede penetration of Li-ion batteries in electric vehicle and energy storage markets. Unfortunately, no fast method to forecast catastrophic failure has existed. This work presents a solution by very early detection of nascent internal shorts that are precursors of catastrophic failure. The new metric, the self-discharge current, which is determined under potentiostatic conditions at a slight discharge overvoltage, is proposed as a fast metric for detection of shorts and assessment of battery safety. The method is non-invasive and applicable to any battery chemistry or design. It is easily adaptable to any battery management system for monitoring battery state of health at any time and at any battery state of charge. The technology based on this method can be used in electric drive vehicles, stationary energy storage, military, aeronautic, as final control in battery production, for first responders in electric vehicle accidents, and many other applications.
Suppression of mode-beating in a saturated hole-coupled FEL oscillator

Abstract In a hole-coupled resonator, either empty or loaded with a linear FEL gain medium, the phenomenon of mode-degeneracy and mode-beating have been studied. When the magnitudes of the eigenvalues, derived from a linear analysis, are equal for two or more dominant eigenmodes, the system cannot achieve a stable beam-profile. We investigate this phenomenon when a saturated FEL is presented within the cavity, thus introducing nonlinearity. We use a three-dimensional FEL oscillator code, based on the amplifier code TDA, and show that mode-beating is suppressed in the nonlinear saturated regime. We suggest a simple, qualitative model for the mechanism responsible for this suppression.
Extubation Failure after Neonatal Cardiac Surgery: A Multicenter Analysis.

Objectives To describe the epidemiology of extubation failure and identify risk factors for its occurrence in a multicenter population of neonates undergoing surgery for congenital heart disease. Study design We conducted a prospective observational study of neonates ≤30 days of age who underwent cardiac surgery at 7 centers within the US in 2015. Extubation failure was defined as reintubation within 72 hours of the first planned extubation. Risk factors were identified with the use of multivariable logistic regression analysis and reported as OR with 95% CIs. Multivariable logistic regression analysis was conducted to examine the relationship between extubation failure and worse clinical outcome, defined as hospital length of stay in the upper 25% or operative mortality. Results We enrolled 283 neonates, of whom 35 (12%) failed their first extubation at a median time of 7.5 hours (range 1-70 hours). In a multivariable model, use of uncuffed endotracheal tubes (OR 4.6; 95% CI 1.8-11.6) and open sternotomy of 4 days or more (OR 4.8; 95% CI 1.3-17.1) were associated independently with extubation failure. Accordingly, extubation failure was determined to be an independent risk factor for worse clinical outcome (OR 5.1; 95% CI 2-13). Conclusions In this multicenter cohort of neonates who underwent surgery for congenital heart disease, extubation failure occurred in 12% of cases and was associated independently with worse clinical outcome. Use of uncuffed endotracheal tubes and prolonged open sternotomy were identified as independent and potentially modifiable risk factors for the occurrence of this precarious complication.
Gamma-Ray Line Afterglow from Burst Environments

We consider photoerosion and direct pair production in a medium surrounding a gamma-ray burst. The resulting secondary gamma-rays may provide diagnostic tools of these environments and, in turn, of the nature of the bursters themselves. In some instances short-lived nuclides are formed; the beta-delayed gamma-rays produced from their decays provide the signatures of the photoerosion. In addition, annihilation radiation produced from positrons resulting from direct pair production is related to the plasma conditions in the medium. We investigate the plausibility of detecting the various radiations. Under extremely favorable conditions, the photoerosion afterglow might be detectable with the present generation of detectors. However, the positron annihilation line should be detectable under a fairly wide range in the conditions of the medium.
Coflow scheduling in input-queued switches: Optimal delay scaling and algorithms

A coflow is a collection of parallel flows belonging to the same job. It has the all-or-nothing property: a coflow is not complete until the completion of all its constituent flows. In this paper, we focus on optimizing coflow-level delay, i.e., the time to complete all the flows in a coflow, in the context of an N × N input-queued switch. In particular, we develop a throughput-optimal scheduling policy that achieves the best scaling of coflow-level delay as N → ∞. We first derive lower bounds on the coflow-level delay that can be achieved by any scheduling policy. It is observed that these lower bounds critically depend on the variability of flow sizes. Then we analyze the coflow-level performance of some existing coflow-agnostic scheduling policies and show that none of them achieves provably optimal performance with respect to coflow-level delay. Finally, we propose the Coflow-Aware Batching (CAB) policy which achieves the optimal scaling of coflow-level delay under some mild assumptions.
MDPs with unawareness in robotics

We formalize decision-making problems in robotics and automated control using continuous MDPs and actions that take place over continuous time intervals. We then approximate the continuous MDP using finer and finer discretizations. Doing this results in a family of systems, each of which has an extremely large action space, although only a few actions are "interesting". We can view the decision maker as being unaware of which actions are "interesting". We an model this using MDPUs, MDPs with unawareness, where the action space is much smaller. As we show, MDPUs can be used as a general framework for learning tasks in robotic problems. We prove results on the difficulty of learning a near-optimal policy in an an MDPU for a continuous task. We apply these ideas to the problem of having a humanoid robot learn on its own how to walk.
Reforming village-level governance via horizontal pressure : evidence from an experiment in Zimbabwe

How can patrimonial local-level governance be reformed? Debates on this topic have focused largely on the possibility of reform via pressure from above (superordinate leaders) or below (citizens). This paper tests whether horizontal pressures from civil society leaders can reform local governance in a context where neither of these mechanisms operates effectively. The study analyzes an experimental intervention in Zimbabwe intended to reduce abuse of power by village heads. Analytic leverage comes from the fact that the 270 study villages were randomly assigned to two variants of the intervention, one in which only village heads were trained on the framework governing village leadership, and one in which civil society leaders were trained alongside village heads. The results suggest that horizontal pressure from civil society leaders increased village heads' knowledge of and compliance with regulated procedures, improved their management of issues and raised citizens' trust in their leadership. A quantitative and qualitative analysis of the mechanisms through which the trained civil society leaders had these effects suggests they accomplished reform by directly applying social pressure on village heads to abide by regulations.
MMI waveguide based multispectral detection of nucleic acids for analysis of drug-resistant bacteria

A multi-mode interference waveguide is used for creating distinct temporal fluorescence patterns at multiple excitation wavelengths. This allows for identification of bacterial nucleic acids labeled with molecular beacons in two colors.
Subwavelength resolution imaging by ultra-thin meta-lens

We demonstrate high numerical aperture (NA=0.8) transmissive metasurface-based lenses with efficiencies as high as 86% in the visible spectrum. Meta-lenses allow diffraction-limited focusing at red (λ=660 nm), green (λ=532 nm), and blue (λ=405 nm) wavelengths. They can resolve nanoscale features with sub-wavelength gaps.
BUCKLING-INDUCED KIRIGAMI

We investigate the mechanical response of thin sheets perforated with a square array of mutually orthogonal cuts, which leaves a network of squares connected by small ligaments. Our combined analytical, experimental and numerical results indicate that under uniaxial tension the ligaments buckle out of plane, inducing the formation of 3D patterns whose morphology is controlled by the load direction. We also find that by largely stretching the buckled perforated sheets, plastic strains develop in the ligaments. This gives rise to the formation of kirigami sheets comprising periodic distribution of cuts and permanent folds. As such, the proposed buckling-induced pop-up strategy points to a simple route for manufacturing complex morphable structures out of flat perforated sheets.
UCP2 Modulates Cell Proliferation through the MAPK/ERK Pathway during Erythropoiesis and Has No Effect on Heme Biosynthesis

UCP2, an inner membrane mitochondrial protein, has been implicated in bioenergetics and Reactive Oxygen Species (ROS) modulation. UCP2 has been previously hypothesized to function as a facilitator of heme synthesis and iron metabolism by reducing ROS production. While UCP2 has been found to be induced by GATA1 during erythroid differentiation its role in erythropoiesis in vivo or in vitro has not been reported thus far. Here we report on the study of UCP2 role in erythropoiesis and the hematologic phenotype of UCP2 deficient mouse. In vivo we found that UCP2 protein peaks at early stages of erythroid maturation when cells are not fully committed in heme synthesis and then becomes undetectable at the reticulocyte stage. Iron incorporation into heme was unaltered in erythroid cells from UCP2 deficient mice. While heme synthesis was not influenced by UCP2 deficiency, mice lacking UCP2 had a delayed recovery from chemically induced hemolytic anemia. Analysis of the erythroid lineage from bone marrow and fetal liver revealed that in the UCP2 deficient mice the R3 (CD71high/Ter119high) population was reduced by 24%. The count of BFU-E and CFU-E colonies, scored in an erythroid colony assay, was unaffected, indicating an equivalent number of early erythroid progenitor cells in both UCP2 deficient and control cells. Ex-vivo differentiation assay revealed that UCP2 deficient c-kit+ progenitor cells expansion was overall reduced by 14% with population analysis determining that the main effect is at the R3 stage. No increased rate of apoptosis was found indicating that expansion rather than cell death is being compromised. Reduced expansion of c-kit+ cells was accompanied by 30% reduction in the phosphorylated form of ERK, a ROS dependent cytosolic regulator of cell proliferation. Analysis of ROS in UCP2 null erythroid progenitors revealed altered distribution of ROS resulting in 14% decrease in cytosolic and 32% increase in mitochondrial ROS. Restoration of the cytosolic oxidative state of erythroid progenitor cells by the pro-oxidant Paraquat reversed the effect of UCP2 deficiency on cell proliferation in in vitro differentiation assays. Together, these results indicate that UCP2 is a regulator of erythropoiesis and suggests that inhibition of UCP2 function may contribute to the development of anemia.
Relative PBW Type Theorems for Symmetrically Braided Hopf Algebras

We show that, for any irreducible symmetrically braided Hopf algebra over a field of characteristic zero, the associated graded algebra with respect to the coradical filtration is a braided symmetric algebra. Consequently, we obtain conditions for a braided Hopf algebra to be of Poincare–Birkhoff–Witt (PBW) type as module over a braided Hopf subalgebra containing the coradical.
Achieving Non-Discrimination in Prediction

Discrimination-aware classification is receiving an increasing attention in data science fields. The pre-process methods for constructing a discrimination-free classifier first remove discrimination from the training data, and then learn the classifier from the cleaned data. However, they lack a theoretical guarantee for the potential discrimination when the classifier is deployed for prediction. In this paper, we fill this gap by mathematically bounding the probability of the discrimination in prediction being within a given interval in terms of the training data and classifier. We adopt the causal model for modeling the data generation mechanism, and formally defining discrimination in population, in a dataset, and in prediction. We obtain two important theoretical results: (1) the discrimination in prediction can still exist even if the discrimination in the training data is completely removed; and (2) not all pre-process methods can ensure non-discrimination in prediction even though they can achieve non-discrimination in the modified training data. Based on the results, we develop a two-phase framework for constructing a discrimination-free classifier with a theoretical guarantee. The experiments demonstrate the theoretical results and show the effectiveness of our two-phase framework.
Split Active Asteroid P/2016 J1 (PANSTARRS)

We present a photometric and astrometric study of the split active asteroid P/2016 J1 (PANSTARRS). The two components (hereafter J1-A and J1-B) separated either ~1500 days (2012 May to June) or 2300 days (2010 April) prior to the current epoch, with a separation speed V sep = 0.70 ± 0.02 m s−1 for the former scenario and 0.83 ± 0.06 m s−1 for the latter. Keck photometry reveals that the two fragments have similar, Sun-like colors that are comparable to the colors of primitive C- and G-type asteroids. With a nominal comet-like albedo, p R = 0.04, the effective, dust-contaminated cross sections are estimated to be 2.4 km2 for J1-A and 0.5 km2 for J1-B. We estimate that the nucleus radii lie in the range 140 R N 900 m for J1-A and 40 R N 400 m for J1-B. A syndyne–synchrone simulation shows that both components have been active for 3–6 months, by ejecting dust grains at speeds ~0.5 m s−1 with rates ~1 kg s−1 for J1-A and 0.1 kg s−1 for J1-B. In its present orbit, the rotational spin-up and devolatilization times of 2016 J1 are very small compared to the age of the solar system, raising the question of why this object still exists. We suggest that ice that was formerly buried within this asteroid became exposed at the surface, perhaps via a small impact, and that sublimation torques then rapidly drove it to breakup. Further disintegration events are anticipated owing to the rotational instability.