cssi/SciSciGPT-SciSciNet huggingface dataset:
Genetic Inhibition of Nfatc2 Attenuates Asparaginase Hypersensitivity in Mice

The family of nuclear factor of activated T cells (NFAT) transcription factors plays a critical role in mediating immune responses. Our previous clinical pharmacogenetic studies suggested that NFATC2 is associated with the risk of hypersensitivity reactions to the chemotherapeutic agent L-asparaginase (ASNase) that worsen outcomes during the treatment of pediatric acute lymphoblastic leukemia. We therefore hypothesized that the genetic inhibition of NFATC2 would protect against the development of anti-ASNase antibodies and ASNase hypersensitivity. Our study demonstrates that ASNase-immunized NFATC2-deficient mice are protected against ASNase hypersensitivity and develop lower antigen-specific and total immunoglobulin E (IgE) levels compared with wild-type (WT) controls. Furthermore, ASNase-immunized NFATC2-deficient mice develop more CD4+ regulatory T cells, fewer CD4+ interleukin-4-positive (IL-4+) cells, higher IL-10/TGF-β1 levels, and lower IL-4/IL-13 levels relative to WT mice. Basophils and peritoneal mast cells from ASNase-immunized, but not naive, NFATC2-deficient mice had lower FceRI expression and decreased IgE-mediated mast cell activation than WT mice. Furthermore, ASNase-immunized, but not naive, NFATC2-deficient mice developed less severe shock than WT mice after induction of passive anaphylaxis or direct histamine administration. Thus, inhibition of NFATC2 protects against ASNase hypersensitivity by impairing T helper 2 responses, which may provide a novel strategy for attenuating hypersensitivity and the development of antidrug antibodies, including to ASNase.
Strategies for identifying dynamic regions in protein complexes: Flexibility changes accompany methylation in chemotaxis receptor signaling states

Abstract Bacterial chemoreceptors are organized in arrays composed of helical receptors arranged as trimers of dimers, coupled to a histidine kinase CheA and a coupling protein CheW. Ligand binding to the external domain inhibits the kinase activity, leading to a change in the swimming behavior. Adaptation to an ongoing stimulus involves reversible methylation and demethylation of specific glutamate residues. However, the exact mechanism of signal propagation through the helical receptor to the histidine kinase remains elusive. Dynamics of the receptor cytoplasmic domain is thought to play an important role in the signal transduction, and current models propose inverse dynamic changes in different regions of the receptor. We hypothesize that the adaptational modification (methylation) controls the dynamics by stabilizing a partially ordered domain, which in turn modulates the binding of the kinase, CheA. We investigated the difference in dynamics between the methylated and unmethylated states of the chemoreceptor using solid-state NMR. The unmethylated receptor (CF4E) shows increased flexibility relative to the methylated mimic (CF4Q). Methylation helix 1 (MH1) has been shown to be flexible in the methylated mimic receptor. Our analysis indicates that in addition to MH1, methylation helix 2 also becomes flexible in the unmethylated receptor. In addition, we have demonstrated that both states of the receptor have a rigid region and segments with intermediate timescale dynamics. The strategies used in this study for identifying dynamic regions are applicable to a broad class of proteins and protein complexes with intrinsic disorder and dynamics spanning multiple timescales.
Engaging with higher education back home: Experiences of African academic diaspora in the US

The research examines the transnational engagement of African born academics in the US. It explores the various dimensions of their multiple and complex constituencies as immigrant academics on one hand, and as academic diaspora on the other.
Decoupling at the Margin: The Threat to Monetary Policy from the Electronic Revolution in Banking

The threat to monetary policy from the electronic revolution in banking is the possibility of a decoupling' of the operations of the central bank from markets in which financial claims are created and transacted in ways that, at some operative margin, affect the decisions of households and firms on such matters as how much to spend (and on what), how much (and what) to produce, and what to pay or charge for ordinary goods and services. The object of this paper is to discuss how this possibility arises and what it implies, to dismiss as unessential to the argument various extreme characterizations that have arisen in the recent debate on this issue (for example, that no one will use money for ordinary economic transactions), and to address the specific arguments on the issue offered by Charles Goodhart, Charles Freedman and Michael Woodford.
Guiding ecological principles for marine spatial planning

Abstract The declining health of marine ecosystems around the world is evidence that current piecemeal governance is inadequate to successfully support healthy coastal and ocean ecosystems and sustain human uses of the ocean. One proposed solution to this problem is ecosystem-based marine spatial planning (MSP), which is a process that informs the spatial distribution of activities in the ocean so that existing and emerging uses can be maintained, use conflicts reduced, and ecosystem health and services protected and sustained for future generations. Because a key goal of ecosystem-based MSP is to maintain the delivery of ecosystem services that humans want and need, it must be based on ecological principles that articulate the scientifically recognized attributes of healthy, functioning ecosystems. These principles should be incorporated into a decision-making framework with clearly defined targets for these ecological attributes. This paper identifies ecological principles for MSP based on a synthesis of previously suggested and/or operationalized principles, along with recommendations generated by a group of twenty ecologists and marine scientists with diverse backgrounds and perspectives on MSP. The proposed four main ecological principles to guide MSP—maintaining or restoring: native species diversity, habitat diversity and heterogeneity, key species, and connectivity—and two additional guidelines, the need to account for context and uncertainty, must be explicitly taken into account in the planning process. When applied in concert with social, economic, and governance principles, these ecological principles can inform the designation and siting of ocean uses and the management of activities in the ocean to maintain or restore healthy ecosystems, allow delivery of marine ecosystem services, and ensure sustainable economic and social benefits.
Visualization of Unsteady Flow Using Heat Kernel Signatures

We introduce a new technique to visualize complex flowing phenomena by using concepts from shape analysis. Our approach uses techniques that examine the intrinsic geometry of manifolds through their heat kernel, to obtain representations of such manifolds that are isometry-invariant and multi-scale. These representations permit us to compute heat kernel signatures of each point on that manifold, and we can use these signatures as features for classification and segmentation that identify points that have similar structural properties. Our approach adapts heat kernel signatures to unsteady flows by formulating a notion of shape where pathlines are observations of a manifold living in a high-dimensional space. We use this space to compute and visualize heat kernel signatures associated with each pathline. Besides being able to capture the structural features of a pathline, heat kernel signatures allow the comparison of pathlines from different flow datasets through a shape matching pipeline. We demonstrate the analytic power of heat kernel signatures by comparing both (1) different timesteps from the same unsteady flow as well as (2) flow datasets taken from ensemble simulations with varying simulation parameters. Our analysis only requires the pathlines themselves, and thus it does not utilize the underlying vector field directly. We make minimal assumptions on the pathlines: while we assume they are sampled from a continuous, unsteady flow, our computations can tolerate pathlines that have varying density and potential unknown boundaries. We evaluate our approach through visualizations of a variety of two-dimensional unsteady flows.
The federal-private wage differential: how has it evolved?

This paper is the first to document and analyse the variation of the federal-private pay differential over time. We estimate the evolution of the federal-private pay differential from 1995 to 2017 ...
Inequality, Nonhomothetic Preferences, And Trade: A Gravity Approach

We construct the first direct classification of goods as luxuries or necessities that is compatible with international trade data. We then use it to test an idea that has not been tested directly in the literature: Countries' income distributions are important determinants of their import demand, and, in particular, of the difference in their import demands of luxuries versus necessities. We interpret this result with the aid of a model in which preferences are nonhomothetic, thus relaxing a long-held and standard?but empirically dubious?assumption in the theory of international trade. Our model is strongly borne out by the results: Imports of luxuries increase with the importing country's inequality, and imports of necessities decrease with it. Our calculations imply that if income distribution in the United States became as equal as in Canada, the United States would import about 9-13% fewer luxury goods and 13-19% more necessities.
Measurement Error in Monetary Aggregates: A Markov Switching Factor Approach

This paper compares the different dynamics of the simple sum monetary aggregates and the Divisia monetary aggregate indexes over time, over the business cycle, and across high and low inflation and interest rate phases. Although traditional comparisons of the series sometimes suggest that simple sum and Divisia monetary aggregates share similar dynamics, there are important differences during certain periods, such as around turning points. These differences cannot be evaluated by their average behavior. We use a factor model with regime switching. The model separates out the common movements underlying the monetary aggregate indexes, summarized in the dynamic factor, from individual variations in each individual series, captured by the idiosyncratic terms. The idiosyncratic terms and the measurement errors reveal where the monetary indexes differ. We find several new results. In general, the idiosyncratic terms for both the simple sum aggregates and the Divisia indexes display a business cycle pattern, especially since 1980. They generally rise around the end of high interest rate phases – a couple of quarters before the beginning of recessions – and fall during recessions to subsequently converge to their average in the beginning of expansions. We find that the major differences between the simple sum aggregates and Divisia indexes occur around the beginnings and ends of economic recessions, and during some high interest rate phases. We note the inferences’ policy relevance, which is particularly dramatic at the broadest (M3) level of aggregation. Indeed, as Belongia (1996) has observed in this regard, “measurement matters.”
$(1,1)$ forms with specified Lagrangian phase: a priori estimates and algebraic obstructions

Let $(X,\alpha)$ be a Kahler manifold of dimension n, and let $[\omega] \in H^{1,1}(X,\mathbb{R})$. We study the problem of specifying the Lagrangian phase of $\omega$ with respect to $\alpha$, which is described by the nonlinear elliptic equation \[ \sum_{i=1}^{n} \arctan(\lambda_i)= h(x) \] where $\lambda_i$ are the eigenvalues of $\omega$ with respect to $\alpha$. When $h(x)$ is a topological constant, this equation corresponds to the deformed Hermitian-Yang-Mills (dHYM) equation, and is related by Mirror Symmetry to the existence of special Lagrangian submanifolds of the mirror. We introduce a notion of subsolution for this equation, and prove a priori $C^{2,\beta}$ estimates when $|h|>(n-2)\frac{\pi}{2}$ and a subsolution exists. Using the method of continuity we show that the dHYM equation admits a smooth solution in the supercritical phase case, whenever a subsolution exists. Finally, we discover some stability-type cohomological obstructions to the existence of solutions to the dHYM equation and we conjecture that when these obstructions vanish the dHYM equation admits a solution. We confirm this conjecture for complex surfaces.
1 – Microcomputer Architecture

Publisher Summary The chapter recognizes that a designer must have a comprehensive knowledge about basic computer architecture and organization. The chapter trades the material devoted to the basics for material needed to design interface systems by offering a summary of the main ideas. It contains essential material on microcomputers and microprocessors needed as a basis for understanding the discussion of interfacing in hardware designing. It helps one to learn about the software view of microcomputers and embedded systems in general, and the MCORE embedded processor in particular. The chapter also describes a programmer's perspective of some of the hardware used in interfacing. It covers bare essentials about von Neumann computers, instructions and what they do, and microcomputers, by surveying the background in architecture that is needed for microcomputer interfacing.
Steiner transitive-closure spanners of low-dimensional posets

Given a directed graph G=(V, E) and an integer k ≥ 1, a k-transitive-closure spanner (k-TC-spanner) of G is a directed graph H=(V, E H ) that has (1) the same transitive closure as G and (2) diameter at most k. In some applications, the shortcut paths added to the graph in order to obtain small diameter can use Steiner vertices, that is, vertices not in the original graph G. The resulting spanner is called a Steiner transitive-closure spanner (Steiner TC-spanner). Motivated by applications to property reconstruction and access control hierarchies, we concentrate on Steiner TC-spanners of directed acyclic graphs or, equivalently, partially ordered sets. In these applications, the goal is to find a sparsest Steiner k-TC-spanner of a poset G for a given k and G. The focus of this paper is the relationship between the dimension of a poset and the size of its sparsest Steiner TC-spanner. The dimension of a poset G is the smallest d such that G can be embedded into a d-dimensional directed hypergrid via an order-preserving embedding. We present a nearly tight lower bound on the size of Steiner 2-TC-spanners of d- dimensional directed hypergrids. It implies better lower bounds on the complexity of local reconstructors of monotone functions and functions with small Lipschitz constant. The lower bound is derived from an explicit dual solution to a linear programming relaxation of the Steiner 2-TC-spanner problem. We also give an efficient construction of Steiner 2-TC-spanners, of size matching the lower bound, for all low-dimensional posets. Finally, we present a lower bound on the size of Steiner k-TC-spanners of d-dimensional posets. It shows that the best-known construction, due to De Santis et al., cannot be improved significantly.
A STUDY OF INTERPLY LAYER EFFECTS ON THE FREE EDGE STRESS FIELD OF ANGLEPLIED LAMINATES

Abstract The general purpose finite element program MSC/NASTRAN is used to study the interply layer effects on the free edge stress field of symmetric angleplied laminates subjected to uniform tensile stress. The free edge region is modeled as a separate substructure (superelement) which enables easy mesh refinement and provides the flexibility to move the superelement along the edge. The results indicated that the effect of interply layer is to reduce the stress intensity at the free edge significantly. Another important observation of the study is that the failures observed near free edges of these types of laminates could have been caused by the interlaminar shear stresses.
Plant Vintage, Technology, and Environmental Regulation

Abstract We use data on productivity and pollution abatement costs at individual pulp and paper mills to test whether the impact of environmental regulation on productivity differs by plant vintage and technology. Plants with higher pollution abatement costs have significantly lower productivity levels. This relationship differs greatly based on a plant's technology, with productivity at integrated mills being greatly affected by abatement costs, while the impact at non-integrated mills is negligible. Plant vintage does not seem to matter, with older and newer plants showing similar impacts. Reported abatement costs appear to substantially understate the true costs of abatement. Accounting for the impact of technology differences makes some difference in the estimated overall impact of environmental regulation.
Chapter 10 – Locomotor Systems

Anyone who has tried to catch a fly or swat a wasp will attest to the impressive accuracy and speed with which insects can maneuver. The investment made in the muscles that power this movement can be substantial: flight muscles alone can comprise as much as 65% of the total body mass of some insects. Compared to the modest five-fold increase in respiratory rates from rest to maximum work in vertebrate muscles, in insect flight muscles these rates can increase by 50–100 times and undergo rates of adenosine triphosphate (ATP) turnover that are triple that of hummingbirds, yet remain essentially aerobic as a result of their high concentrations of mitochondria and adequate supply of oxygen. At the same time, the muscular apparatus is minuscule compared to that of vertebrates. One of the smallest of all flying animals is a chalcid wasp, with a wing span of 1.4 mm and a total mass of 0.025 mg, yet it contains all the muscles and control mechanisms that enable it to fly with uncanny precision. Their efficient movement on land and in the air is a major factor in the domination of terrestrial ecosystems by insects.
Chapter 6 – Membrane Proteins

Membranes are composed primarily of lipids (Chapters 4 and 5 Chapter 4 Chapter 5) and proteins (Chapter 6) with a variable amount of carbohydrates ( Chapter 7) attached to the surface [1]. By number, lipids are the major component of all membranes where they exceed proteins by approximately 40 to 1 up to 200 to 1 and are responsible for the basic membrane structure and environment. Lipids however do not directly express any biochemical catalytic activity. The amount of proteins in a membrane varies over a wide range, depending on how biochemically active the membrane is ( Chapter 1). It has been estimated that more than half of all proteins have some association with a membrane. At the low extreme is the myelin sheath whose primary function is to insulate nerve cells. Approximately 20% of the myelin sheath by weight is protein. Myelin lipids outnumber the proteins by approximately 200 to 1. At the other extreme is the mitochondrial inner membrane that supports many complex functions, including electron transport, oxidative phosphorylation ( Chapter 18), and numerous trans-membrane transport systems. By weight this membrane is approximately 75% protein. But even here, lipids outnumber the proteins by more than 40 to 1. Since different types of membranes have very different functions but have similar basic physical properties, there is far more functional diversity observed in membrane proteins than is found in membrane lipids.
Income changes and consumption: Evidence from the 2013 federal government shutdown

Abstract We use the 2013 federal government shutdown and a rich data set from an online personal finance website to study the effects of changes in income on changes in consumption for thousands of affected workers. The 2013 shutdown represented a significant and unanticipated income shock for federal government workers, with no direct effect on permanent income. We exploit both the differences between unaffected state government employees and affected federal employees as well as between federal employees required to remain at work and those required to stay at home to generate variation in income and available time. We find strong evidence for excess sensitivity of consumption patterns, violating the permanent income hypothesis. We demonstrate that increased home production, changes in spending allocations, and credit constraints all play significant roles in driving spending. We discern detailed categories of household spending with widely varying elasticities. The results demonstrate the importance of household liquidity, leisure, and home production when constructing stimulus or social insurance policy.
Tumor Suppressor Gene Mutations in Mice

Over the past several years, a number of human tumor suppressor genes have been cloned and characterized. Germline mutations in tumor suppressor genes strongly predispose to cancer, and they are also mutated somatically in sporadic forms of the disease. In order to create animal models for the familial cancer syndromes caused by inherited mutations in these genes as well as to determine their role in embryogenesis, the homologues of several members of this class have been mutated in the mouse. The initial characterization of the heterozygous and homozygous phenotypes caused by these mutations has led to important insights into the mechanisms by which tumor suppressor genes participate in normal development and how their loss contributes to tumorigenesis.
Lusztig induction, unipotent supports, and character bounds

Recently, a strong exponential character bound has been established in [3] for all elements $g \in \mathbf{G}^F$ of a finite reductive group $\mathbf{G}^F$ which satisfy the condition that the centraliser $C_{\mathbf{G}}(g)$ is contained in a $(\mathbf{G},F)$-split Levi subgroup $\mathbf{M}$ of $\mathbf{G}$ and that $\mathbf{G}$ is defined over a field of good characteristic. In this paper, assuming a weak version of Lusztig's conjecture relating irreducible characters and characteristic functions of character sheaves holds, we considerably generalize this result by removing the condition that $\mathbf{M}$ is split. This assumption is known to hold whenever $Z(\mathbf{G})$ is connected or when $\mathbf{G}$ is a special linear or symplectic group and $\mathbf{G}$ is defined over a sufficiently large finite field.
Vertebra-Focused Landmark Detection for Scoliosis Assessment

Adolescent idiopathic scoliosis (AIS) is a lifetime disease that arises in children. Accurate estimation of Cobb angles of the scoliosis is essential for clinicians to make diagnosis and treatment decisions. The Cobb angles are measured according to the vertebrae landmarks. Existing regression-based methods for the vertebra landmark detection typically suffer from large dense mapping parameters and inaccurate landmark localization. The segmentation-based methods tend to predict connected or corrupted vertebra masks. In this paper, we propose a novel vertebra-focused landmark detection method. Our model first localizes the vertebra centers, based on which it then traces the four corner landmarks of the vertebra through the learned corner offset. In this way, our method is able to keep the order of the landmarks. The comparison results demonstrate the merits of our method in both Cobb angle measurement and landmark detection on low-contrast and ambiguous X-ray images. Code is available at: https://github.com/yijingru/Vertebra-Landmark-Detection.
Connectomic consistency: a systematic stability analysis of structural and functional connectivity.

Connectomics, the study of brain connectivity, has become an indispensable tool in neuroscientific research as it provides insights into brain organization. Connectomes are generated using different modalities such as diffusion MRI to capture structural organization of the brain or functional MRI to elaborate brain's functional organization. Understanding links between structural and functional organizations is crucial in explaining how observed behavior emerges from the underlying neurobiological mechanisms. Many studies have investigated how these two organizations relate to each other; however, we still lack a comparative understanding on how much variation should be expected in the two modalities, both between people and within a single person across scans. In this study, we systematically analyzed the consistency of connectomes, that is the similarity between connectomes in terms of individual connections between brain regions and in terms of overall network topology. We present a comprehensive study of consistency in connectomes for a single subject examined longitudinally and across a large cohort of subjects cross-sectionally, in structure and function separately. Within structural connectomes, we compared connectomes generated by different tracking algorithms, parcellations, edge weighting schemes, and edge pruning techniques. In functional connectomes, we compared full, positive, and negative connectivity separately along with thresholding of weak edges. We evaluated consistency using correlation (incorporating information at the level of individual edges) and graph matching accuracy (evaluating connectivity at the level of network topology) . We also examined the consistency of connectomes that are generated using different communication schemes. Our results demonstrate varying degrees of consistency for the two modalities, with structural connectomes showing higher consistency than functional connectomes. Moreover, we observed a wide variation in consistency depending on how connectomes are generated. Our study sets a reference point for consistency of connectome types, which is especially important for structure-function coupling studies in evaluating mismatches between modalities.
Automating Software Citation using GitCite

The ability to cite software and give credit to its authors and contributors is increasingly important. While the number of online open-source software repositories has grown rapidly over the past few years, few are being properly cited when used due to the difficulty of creating appropriate citations and the lack of automated techniques. This paper presents GitCite, a model for software citation with version control which enables citations to be inferred for any project component based on a small number of explicit citations attached to subdirectories/files, and an implementation that integrates with Git and GitHub. The implementation includes a browser extension and a local executable tool, which enable citations to be added/modified/deleted to software project repositories and managed through functions such as fork/merge/copy.
Adjustment Criteria for Recovering Causal Effects from Missing Data

Confounding bias, missing data, and selection bias are three common obstacles to valid causal inference in the data sciences. Covariate adjustment is the most pervasive technique for recovering casual effects from confounding bias. In this paper we introduce a covariate adjustment formulation for controlling confounding bias in the presence of missing-not-at-random data and develop a necessary and sufficient condition for recovering causal effects using the adjustment. We also introduce an adjustment formulation for controlling both confounding and selection biases in the presence of missing data and develop a necessary and sufficient condition for valid adjustment. Furthermore, we present an algorithm that lists all valid adjustment sets and an algorithm that finds a valid adjustment set containing the minimum number of variables, which are useful for researchers interested in selecting adjustment sets with desired properties.
Empirical Study of Effect of Dynamic Travel Time Information on Driver Route Choice Behavior

The objective of this paper is to study the effect of travel time information on day-to-day driver route choice behavior. A real-world experimental study is designed to have participants repeatedly choose between two alternative routes for five origin-destination pairs over multiple days after providing them with dynamically updated travel time information (average travel time and travel time variability). The results demonstrate that historical travel time information enhances behavioral rationality by 10% on average and reduces inertial tendencies to increase risk seeking in the gain domain. Furthermore, expected travel time information is demonstrated to be more effective than travel time variability information in enhancing rational behavior when drivers have limited experiences. After drivers gain sufficient knowledge of routes, however, the difference in behavior associated with the two information types becomes insignificant. The results also demonstrate that, when drivers lack experience, the faster less reliable route is more attractive than the slower more reliable route. However, with cumulative experiences, drivers become more willing to take the more reliable route given that they are reluctant to become risk seekers once experience is gained. Furthermore, the effect of information on driver behavior differs significantly by participant and trip, which is, to a large extent, dependent on personal traits and trip characteristics.
Using Markov Chains to Determine Expected Propagation Time for Probabilistic Zero Forcing

Zero forcing is a coloring game played on a graph where each vertex is initially colored blue or white and the goal is to color all the vertices blue by repeated use of a (deterministic) color change rule starting with as few blue vertices as possible. Probabilistic zero forcing yields a discrete dynamical system governed by a Markov chain. Since in a connected graph any one vertex can eventually color the entire graph blue using probabilistic zero forcing, the expected time to do this is studied. Given a Markov transition matrix for a probabilistic zero forcing process, an exact formula is established for expected propagation time. Markov chains are applied to determine bounds on expected propagation time for various families of graphs.
Genome-Wide Association Study in New York Phytophthora capsici Isolates Reveals Loci Involved in Mating Type and Mefenoxam Sensitivity.

Phytophthora capsici is a soilborne oomycete plant pathogen that causes severe vegetable crop losses in New York (NY) state and worldwide. This pathogen is difficult to manage, in part due to its p...
Tight Decomposition Functions for Continuous-Time Mixed-Monotone Systems With Disturbances

The vector field of a mixed-monotone system is decomposable via a decomposition function into increasing (cooperative) and decreasing (competitive) components, and this decomposition allows for, e.g., efficient computation of reachable sets and forward invariant sets. A main challenge in this approach, however, is identifying an appropriate decomposition function. In this letter, we show that any continuous-time dynamical system with a Lipschitz continuous vector field is mixed-monotone, and we provide a construction for the decomposition function that yields the tightest approximation of reachable sets when used with the standard tools for mixed-monotone systems. Our construction is similar to that recently proposed by Yang and Ozay for computing decomposition functions of discrete-time systems where we make appropriate modifications for the continuous-time setting and also extend to the case with unknown disturbance inputs. As in Yang's and Ozay's work, our decomposition function construction requires solving an optimization problem for each point in the state-space; however, we demonstrate through example how tight decomposition functions can sometimes be calculated in closed form. As a second contribution, we show how under-approximations of reachable sets can be efficiently computed via the mixed-monotonicity property by considering the backward-time dynamics.
Maximum Power Point Tracking for Wind Turbine Using Integrated Generator–Rectifier Systems

Offshore wind is a rapidly growing renewable energy resource. Harvesting offshore energy requires multimegawatt wind turbines and high efficiency, high power density, and reliable power conversion systems to achieve a competitive levelized cost of electricity. An integrated system utilizing one active and multiple passive rectifiers with a multiport permanent magnet synchronous generator is a promising alternative for an electromechanical power conversion system. Deployment of the integrated systems in offshore wind energy requires maximum power point tracking (MPPT) capability, which is challenging due to the presence of numerous uncontrolled passive rectifiers. This article shows feasibility of MPPT based on a finding that the active-rectifier $d$ -axis current can control the total system output power. The MPPT capability opens up opportunities for the integrated systems in offshore wind applications.
Life History Effects on Neutral Diversity Levels of Autosomes and Sex Chromosomes

Understanding the determinants of neutral diversity patterns on autosomes and sex chromosomes provides a bedrock for the interpretation of population genetic data; in particular, differences between the two informs our understanding of sex-specific demographic and mutation processes. While sex-specific age-structure and variation in reproductive success have long been known to affect neutral diversity, theoretical descriptions of these effects were complicated and lacking in generality, stymying attempts to relate diversity patterns of species with their life history. Here, we derive general yet simple expressions for these effects. In particular, we show that life history effects on X-to-autosome ratios of pairwise diversity levels (X:A diversity ratios) depend only on the male-to-female ratios of mutation rates, generation times, and reproductive variances. Our results reveal that changing the male-to-female ratio of generation times has opposite effects on X:A ratios of diversity and divergence. They also explain how sex-specific life histories modulate the response of X:A diversity ratios to changes in population size. More generally, they clarify that sex-specific life history—generation times in particular—should have marked effects on X:A diversity ratios in many taxa and enable further investigation of these effects.
Stokes Vector Spectroscopy of Nonlinear Depolarized Light

Experimental Stokes vector spectroscopy characterizes polarization state noise in nonlinear fiber transmission. Noise bandwidths of a few MHz are observed from XPM-blurred receive SOPs using a polarization scrambling interferometer. This method can detect data pattern correlations among WDM channels that contribute to performance degradations in signalling.
A Simple and Approximately Optimal Mechanism for an Additive Buyer

We consider a monopolist seller with n heterogeneous items, facing a single buyer. The buyer has a value for each item drawn independently according to (non-identical) distributions, and her value for a set of items is additive. The seller aims to maximize his revenue. We suggest using the a priori better of two simple pricing methods: selling the items separately, each at its optimal price, and bundling together, in which the entire set of items is sold as one bundle at its optimal price. We show that for any distribution, this mechanism achieves a constant-factor approximation to the optimal revenue. Beyond its simplicity, this is the first computationally tractable mechanism to obtain a constant-factor approximation for this multi-parameter problem. We additionally discuss extensions to multiple buyers and to valuations that are correlated across items.
On Emergent Communication in Competitive Multi-Agent Teams

Several recent works have found the emergence of grounded compositional language in the communication protocols developed by mostly cooperative multi-agent systems when learned end-to-end to maximize performance on a downstream task. However, human populations learn to solve complex tasks involving communicative behaviors not only in fully cooperative settings but also in scenarios where competition acts as an additional external pressure for improvement. In this work, we investigate whether competition for performance from an external, similar agent team could act as a social influence that encourages multi-agent populations to develop better communication protocols for improved performance, compositionality, and convergence speed. We start from Task & Talk, a previously proposed referential game between two cooperative agents as our testbed and extend it into Task, Talk & Compete, a game involving two competitive teams each consisting of two aforementioned cooperative agents. Using this new setting, we provide an empirical study demonstrating the impact of competitive influence on multi-agent teams. Our results show that an external competitive influence leads to improved accuracy and generalization, as well as faster emergence of communicative languages that are more informative and compositional.
Sentiment Paradoxes in Social Networks: Why Your Friends Are More Positive Than You?

Most people consider their friends to be more positive than themselves, exhibiting a Sentiment Paradox. Psychology research attributes this paradox to human cognition bias. With the goal to understand this phenomenon, we study sentiment paradoxes in social networks. Our work shows that social connections (friends, followees, or followers) of users are indeed (not just illusively) more positive than the users themselves. This is mostly due to positive users having more friends. We identify five sentiment paradoxes at different network levels ranging from triads to large-scale communities. Empirical and theoretical evidence are provided to validate the existence of such sentiment paradoxes. By investigating the relationships between the sentiment paradox and other well-developed network paradoxes, i.e., friendship paradox and activity paradox, we find that user sentiments are positively correlated to their number of friends but rarely to their social activity. Finally, we demonstrate how sentiment paradoxes can be used to predict user sentiments.
miR-206 enforces a slow muscle phenotype.

Striated muscle is a highly specialized collection of tissues with contractile properties varying according to functional needs. Although muscle fiber types are established postnatally, lifelong plasticity facilitates stimulus-dependent adaptation. Functional adaptation requires molecular adaptation, partially provided by miRNA-mediated post-transcriptional regulation. miR-206 is a muscle-specific miRNA enriched in slow muscles. We investigated whether miR-206 drives the slow muscle phenotype or is merely an outcome. We found that miR-206 expression increases in both physiologic (including female sex and endurance exercise) and pathologic conditions (muscular dystrophy and adrenergic agonism) that promote a slow phenotype. Consistent with that observation, the slow soleus muscle of male miR-206 knockout mice displays a faster phenotype than wild-type mice. Moreover, left ventricles of male miR-206 knockout mice have a faster myosin profile accompanied by dilation and systolic dysfunction. Thus, miR-206 appears necessary to enforce a slow skeletal and cardiac muscle phenotype and to play a key role in muscle sexual dimorphisms.
Fast fragmentation during surface-induced dissociation: An examination of peptide size and structure

Abstract We present the results of direct dynamics simulations of surface-induced dissociation for protonated versions of AnK, KAn (n = 1, 3, and 5), AcA7K, and AcKA7 for collisions with a fluorinated self-assembled monolayer surface. We focus on elucidating fast fragmentation events, which takes place in coincidence with the collision event. Such events generate a large number of products, and hence, are not easily understood through chemical intuition. Our simulations show distinct differences between the AnK/AcA7K and KAn/AcKA7 series of peptides, with the former being more reactive, and the latter more selective. Backbone rearrangements and sidechain fragmentation are also seen.
Adversarial Perturbations of Opinion Dynamics in Networks

In this paper, we study the connections between network structure, opinion dynamics, and an adversary's power to artificially induce disagreements. We approach these questions by extending models of opinion formation in the mathematical social sciences to represent scenarios, familiar from recent events, in which external actors have sought to destabilize communities through sophisticated information warfare tactics via fake news and bots. In many instances, the intrinsic goals of these efforts are not necessarily to shift the overall sentiment of the network towards a particular policy, but rather to induce discord. These perturbations will diffuse via opinion dynamics on the underlying network, through mechanisms that have been analyzed and abstracted through work in computer science and the social sciences. Here we investigate the properties of such attacks, considering optimal strategies both for the adversary seeking to create disagreement and for the entities tasked with defending the network from attack. By employing spectral techniques, we show that for different formulations of these types of objectives, different regimes of the spectral structure of the network will limit the adversary's capacity to sow discord; in fact, somewhat surprisingly, the entire spectrum can be relevant, rather than just the extreme eigenvectors. Via the strong connections between spectral and structural properties of graphs, we are able to qualitatively describe which networks are most vulnerable or resilient against these perturbations. We then consider the algorithmic task of a network defender to mitigate these sorts of adversarial attacks by insulating nodes heterogeneously; we show that, by considering the geometry of this problem, this optimization task can be efficiently solved via convex programming. Finally, we generalize these results to allow for two network structures, where the opinion dynamics process and the measurement of disagreement become uncoupled; for instance, this may arise when opinion dynamics are controlled by an online community via social media, while disagreement is measured along "real-world" connections. We characterize conditions on the relationship between these two graphs that will determine how much power the adversary gains when this occurs.
How nonlinear is it? A tutorial on nonlinearity of orbit and attitude dynamics

Some observations are made on coordinate selection for the two most fundamental problems of astrodynamics, namely orbit dynamics and attitude dynamics, and some interesting connections and analogies between the two problems are explored. While an infinity of coordinate choices are feasible for each of these problems, we review four coordinate choices for each problem, including several that lead to governing differential equations that are regular, and in some cases, rigorously linear. Some methodology is introduced that has a universal flavor with implications for dynamical systems broadly. We show how dramatic qualitative and quantitative alteration of the mathematical description of the motion can be accomplished by introduction of redundant coordinates to describe the evolution of the dynamics in a higher dimensioned space. Some observations are made on an analogy between the two central problems of interest. One of the regularizing transformations studied for orbital dynamics is motivated directly by this analogy. Finally broadly applicable analytical and computational developments are presented that provide a measure of nonlinearity over a worst-case region of state space in the vicinity of a reference trajectory; this measure is used to evaluate the several coordinate choices.
Assessing Atherosclerotic Cardiovascular Disease Risk with Advanced Lipid Testing: State of the Science

Cardiovascular disease is the number one cause of death and disability worldwide. While substantial gains have been made in reducing cardiovascular mortality, future projections suggest that we have reached a nadir and may be at an inflection point, given the rising tide of obesity and diabetes. Evaluation and management of plasma lipids is central to the prevention of atherosclerotic cardiovascular disease. Although the standard lipid panel represents a well-established platform to assess risk, this test alone can be insufficient and/or misleading. Advances in our understanding of atherosclerosis have led to the development of lipid-based biomarkers that help to discriminate the risk of cardiovascular disease when it is unclear. While these biomarkers provide novel information, their implementation into clinical medicine remains difficult given discrepancies in the literature, lack of assay standardisation, poor accessibility and high cost. However, additional measures of atherogenic lipoproteins or their surrogates may offer insight beyond the standard lipid panel, providing a more precise assessment of risk and more accurate assessment of lipid-lowering therapy.
Experimental Evaluation of Human Motion Prediction Toward Safe and Efficient Human Robot Collaboration

Human motion prediction is non-trivial in modern industrial settings. Accurate prediction of human motion can not only improve efficiency in human-robot collaboration, but also enhance human safety in close proximity to robots. Although many prediction models have been proposed with various parameterization and identification approaches, some fundamental questions remain unclear: what is the necessary parameterization of a prediction model? Is online adaptation of models necessary? Can a prediction model help improve safety and efficiency during human-robot collaboration? These unaddressed questions result from the difficulty of quantitatively evaluating different prediction models in a closed-loop fashion in real human-robot interaction. This paper develops a method to evaluate the closed-loop performance of different prediction models. In particular, we compare models with different parameterizations and models with or without online parameter adaptation. Extensive experiments were conducted on a human-robot collaboration platform. The experimental results demonstrate that human motion prediction significantly enhance the collaboration efficiency and human safety. Adaptable prediction models that are parameterized by neural networks achieve better performance.
Atomistic study of grain-boundary segregation and grain-boundary diffusion in Al-Mg alloys

Abstract Mg grain boundary (GB) segregation and GB diffusion can impact the processing and properties of Al-Mg alloys. Yet, Mg GB diffusion in Al has not been measured experimentally or predicted by simulations. We apply atomistic computer simulations to predict the amount and the free energy of Mg GB segregation, and the impact of segregation on GB diffusion of both alloy components. At low temperatures, Mg atoms segregated to a tilt GB form clusters with highly anisotropic shapes. Mg diffuses in Al GBs slower than Al itself, and both components diffuse slowly in comparison with Al GB self-diffusion. Thus, Mg segregation significantly reduces the rate of mass transport along GBs in Al-Mg alloys. The reduced atomic mobility can be responsible for the improved stability of the microstructure at elevated temperatures.
Democracy promotion and electoral quality: A disaggregated analysis

This research was supported, in part, by: National Science Foundation, Grant SES‐1423944; Riksbankens Jubileumsfond, Grant M13‐0559:1.