cssi/SciSciGPT-SciSciNet huggingface dataset:
STABILITY and OCCURRENCE RATE CONSTRAINTS on the PLANETARY SCULPTING HYPOTHESIS for "tRANSITIONAL" DISKS

Transitional disks, protoplanetary disks with deep and wide central gaps, may be the result of planetary sculpting. By comparing numerical planet-opening-gap models with observed gaps, we find systems of 3-6 giant planets are needed in order to open gaps with the observed depths and widths. We explore the dynamical stability of such multi-planet systems using N-body simulations that incorporate prescriptions for gas effects. We find they can be stable over a typical disk lifetime, with the help of eccentricity damping from the residual gap gas that facilitates planets locking into mean motion resonances. However, in order to account for the occurrence rate of transitional disks, the planet sculpting scenario demands gap-opening-friendly disk conditions, in particular, a disk viscosity $\alpha\lesssim0.001$. In addition, the demography of giant planets at $\sim 3-30$ AU separations, poorly constrained by current data, has to largely follow occurrence rates extrapolated outward from radial velocity surveys, not the lower occurrence rates extrapolated inward from direct imaging surveys. Even with the most optimistic occurrence rates, transitional disks cannot be a common phase that most gas disks experience at the end of their life, as popularly assumed, simply because there are not enough planets to open these gaps. Finally, as consequences of demanding almost all giant planets at large separations participate in transitional disk sculpting, the majority of such planets must form early and end up in a chain of mean motion resonances at the end of disk lifetime.
Escell: Emergent Symbolic Cellular Language

We present ESCELL, a method for developing an emergent symbolic language of communication between multiple agents reasoning about cells. We show how agents are able to cooperate and communicate successfully in the form of symbols similar to human language to accomplish a task in the form of a referential game (Lewis‘ signaling game). In one form of the game, a sender and a receiver observe a set of cells from 5 different cell phenotypes. The sender is told one cell is a target and is allowed to send one symbol to the receiver from a fixed arbitrary vocabulary size. The receiver relies on the information in the symbol to identify the target cell. We train the sender and receiver networks to develop an innate emergent language between themselves to accomplish this task. We observe that the networks are able to successfully identify cells from 5 different phenotypes with an accuracy of 93.2%. We also introduce a new form of the signaling game where the sender is shown one image instead of all the images that the receiver sees. The networks successfully develop an emergent language to get an identification accuracy of 77.8%.
Difficulties of quantitative tests of the Kerr-hypothesis with X-ray observations of mass accreting black holes

X-ray studies of stellar mass black holes in X-ray binaries and mass-accreting supermassive black holes in Active Galactic Nuclei have achieved a high degree of maturity and have delivered detailed information about the astrophysical sources and the physics of black hole accretion. In this article, I review recent progress made towards using the X-ray observations for testing the “Kerr hypothesis” that the background spacetimes of all astrophysical quasi-stationary black holes are described by the Kerr metric. Although the observations have indeed revealed clear evidence for relativistic effects in strong-field gravity, quantitative tests of the Kerr hypothesis still struggle with theoretical and practical difficulties. In this article, I describe several recently introduced test metrics and review the status of constraining the background spacetimes of mass accreting stellar mass and supermassive black holes with these test metrics. The main conclusion of the discussion is that astrophysical uncertainties are large compared to the rather small observational differences between the Kerr and non-Kerr metrics precluding quantitative constraints on deviations from the Kerr metric at this point in time. I conclude with discussing future progress enabled by more detailed numerical simulations and by future X-ray spectroscopy, timing, polarimetry, and interferometry missions.
The theory of braids

The theory of braids shows the interplay of two disciplines of pure mathematics? topology, used in the definition of braids, and the theory of groups, used in their treatment. The fundamentals of the theory can be understood without too much technical knowledge. It originated from a much older problem in pure mathematics?the classification of knots. Much progress has been achieved in this field ; but all the prog ress seems only to emphasize the extreme difficulty of the problem. Today we are still very far from a complete solution. In view of this fact it is advisable to study objects that are in some fashion similar to knots, yet simple enough so as to make a complete classification possible. Braids are such objects. In order to develop the theory of braids we first explain what we call a weaving pat tern of order ( being an ordinary inte gral number which is taken to be 5 in Fig. 1). Let Li and L2 be two parallel straight lines in space with given orientation in the same sense (indicated by arrows). If is a point on Lh Q a point on L2, we shall sometimes join and Q by a curve c. In our drawings we can only indicate the pro jection of c onto the plane containing L\
Space-efficient knot mosaics for prime knots with mosaic number 6

In 2008, Kauffman and Lomonaco introduced the concepts of a knot mosaic and the mosaic number of a knot or link K, the smallest integer n such that K can be represented on an n-mosaic. In 2018, the authors of this paper introduced and explored space-efficient knot mosaics and the tile number of K, the smallest number of nonblank tiles necessary to depict K on a knot mosaic. They determine bounds for the tile number in terms of the mosaic number. In this paper, we focus specifically on prime knots with mosaic number 6. We determine a complete list of these knots, provide a minimal, space-efficient knot mosaic for each of them, and determine the tile number (or minimal mosaic tile number) of each of them.
On moduli spaces of flat connections with non-simply connected structure group

Abstract We consider the moduli space of flat G-bundles over the two-dimensional torus, where G is a real, compact, simple Lie group which is not simply connected. We show that the connected components that describe topologically non-trivial bundles are isomorphic as symplectic spaces to moduli spaces of topologically trivial bundles with a different structure group. Some physical applications of this isomorphism which allows one to trade topological non-triviality for a change of the gauge group are sketched.
Quantile regression for mixed models with an application to examine blood pressure trends in China

Cardiometabolic diseases have substantially increased in China in the past 20 years and blood pressure is a primary modifiable risk factor. Using data from the China Health and Nutrition Survey we examine blood pressure trends in China from 1991 to 2009, with a concentration on age cohorts and urbanicity. Very large values of blood pressure are of interest, so we model the conditional quantile functions of systolic and diastolic blood pressure. This allows the covariate effects in the middle of the distribution to vary from those in the upper tail, the focal point of our analysis. We join the distributions of systolic and diastolic blood pressure using a copula, which permits the relationships between the covariates and the two responses to share information and enables probabilistic statements about systolic and diastolic blood pressure jointly. Our copula maintains the marginal distributions of the group quantile effects while accounting for within-subject dependence, enabling inference at the population and subject levels. Our population level regression effects change across quantile level, year, and blood pressure type, providing a rich environment for inference. To our knowledge, this is the first quantile function model to explicitly model within-subject autocorrelation and is the first quantile function approach that simultaneously models multivariate conditional response. We find that the association between high blood pressure and living in an urban area has evolved from positive to negative, with the strongest changes occurring in the upper tail. The increase in urbanization over the last twenty years coupled with the transition from the positive association between urbanization and blood pressure in earlier years to a more uniform association with urbanization suggests increasing blood pressure over time throughout China, even in less urbanized areas. Our methods are available in the R package BSquare.
SUDDEN PHOTOSPHERIC MOTION AND SUNSPOT ROTATION ASSOCIATED WITH THE X2.2 FLARE ON 2011 FEBRUARY 15

The Helioseismic and Magnetic Imager provides 45 s cadence intensity images and 720 s cadence vector magnetograms. These unprecedented high-cadence and high-resolution data give us a unique opportunity to study the change of photospheric flows and sunspot rotations associated with flares. By using the differential affine velocity estimator method and the Fourier local correlation tracking method separately, we calculate velocity and vorticity of photospheric flows in the flaring NOAA AR 11158, and investigate their temporal evolution around the X2.2 flare on 2011 February 15. It is found that the shear flow around the flaring magnetic polarity inversion line exhibits a sudden decrease, and both of the two main sunspots undergo a sudden change in rotational motion during the impulsive phase of the flare. These results are discussed in the context of the Lorentz-force change that was proposed by Hudson et al. and Fisher et al. This mechanism can explain the connections between the rapid and irreversible photospheric vector magnetic field change and the observed short-term motions associated with the flare. In particular, the torque provided by the horizontal Lorentz force change agrees with what is required for the measured angular acceleration.
Switching Time of Spin-Torque-Driven Magnetization in Biaxial Ferromagnets

We analytically model the magnetization switching time of a biaxial ferromagnet driven by an antidampinglike spin torque. The macrospin magnetization dynamics is mapped to an energy-flow equation, wherein a rational-function approximation for the elliptic integrals for moderate spin current and small damping results in a closed-form expression for the switching time. The randomness in the initial angle of magnetization gives the distribution function of the switching time. The analytical model conforms to results obtained from Monte Carlo simulation for a broad range of material parameters. Our results can improve the design and benchmarking of in-plane spin-torque magnetic memory by obviating the need for expensive numerical computation.
Trouble with the Lorentz law of force: response to critics

In a recent paper, we questioned the validity of the Lorentz law of force in the presence of material media that contain electric and/or magnetic dipoles. A number of authors have criticized our methods and conclusions. This paper is an attempt at answering the critics and elaborating the relevant issues in some detail.
Ultra-high spatial resolution BOLD fMRI in humans using combined segmented-accelerated VFA-FLEET with a recursive RF pulse design.

PURPOSE To alleviate the spatial encoding limitations of single-shot echo-planar imaging (EPI) by developing multi-shot segmented EPI for ultra-high-resolution functional MRI (fMRI) with reduced ghosting artifacts from subject motion and respiration. THEORY AND METHODS Segmented EPI can reduce readout duration and reduce acceleration factors, however, the time elapsed between segment acquisitions (on the order of seconds) can result in intermittent ghosting, limiting its use for fMRI. Here, "FLEET" segment ordering, where segments are looped over before slices, was combined with a variable flip angle progression (VFA-FLEET) to improve inter-segment fidelity and maximize signal for fMRI. Scaling a sinc pulse's flip angle for each segment (VFA-FLEET-Sinc) produced inconsistent slice profiles and ghosting, therefore, a recursive Shinnar-Le Roux (SLR) radiofrequency (RF) pulse design was developed (VFA-FLEET-SLR) to generate unique pulses for every segment that together produce consistent slice profiles and signals. RESULTS The temporal stability of VFA-FLEET-SLR was compared against conventional-segmented EPI and VFA-FLEET-Sinc at 3T and 7T. VFA-FLEET-SLR showed reductions in both intermittent and stable ghosting compared to conventional-segmented and VFA-FLEET-Sinc, resulting in improved image quality with a minor trade-off in temporal SNR. Combining VFA-FLEET-SLR with acceleration, we achieved a 0.6-mm isotropic acquisition at 7T, without zoomed imaging or partial Fourier, demonstrating reliable detection of blood oxygenation level-dependent (BOLD) responses to a visual stimulus. To counteract the increased repetition time from segmentation, simultaneous multi-slice VFA-FLEET-SLR was demonstrated using RF-encoded controlled aliasing. CONCLUSIONS VFA-FLEET with a recursive RF pulse design supports acquisitions with low levels of artifact and spatial blur, enabling fMRI at previously inaccessible spatial resolutions with a "full-brain" field of view.
Hyperbolicity of the trace map for the weakly coupled Fibonacci Hamiltonian

We consider the trace map associated with the Fibonacci Hamiltonian as a diffeomorphism on the invariant surface associated with a given coupling constant and prove that the non-wandering set of this map is hyperbolic if the coupling is sufficiently small. As a consequence, for these values of the coupling constant, the local and global Hausdorff dimension and the local and global box counting dimension of the spectrum of the Fibonacci Hamiltonian all coincide and are smooth functions of the coupling constant.
Grand unification in higher dimensions with split supersymmetry

We investigate gauge coupling unification in higher dimensional GUT models with split supersymmetry. We focus on 5d and 6d orbifold GUTs, which permit a simple solution to several problems of 4D GUTs as well as control over GUT scale threshold corrections. In orbifold GUTs, calculable threshold corrections can raise or lower the prediction for αs(MZ) in a way that depends on the location of Higgs fields. On the other hand, split supersymmetry lowers the prediction for αs(MZ). Consequently, split supersymmetry changes the preferred location of the Higgs fields in orbifold GUTs. In the simplest models, we find that gauge coupling unification favors higgs doublets that live on the orbifold fixed points instead of in the bulk. In addition, relatively high scales of supersymmetry breaking of 1010±2 GeV are generically favored.
Finite approximations of p–local compact groups

In view of the many classes of groups and other mathematical objects that p-local compact groups model, it is no surprise that this theory is not very well understood yet. Nevertheless several structural results have already been conjectured since its introduction in [7], of which two are of special relevance in this work. The first conjecture asks about the existence of a version of the Stable Elements Theorem by H. Cartan and S. Eilenberg [10, Theorem 10.1] for p-local compact groups, while the second conjecture suggests the extension of the classic result of W. Dwyer and A. Zabrodsky [17, Theorem 1.1] on mapping spaces to p-local compact groups.
Magnetic Nanoparticles in the Interstellar Medium: Emission Spectrum and Polarization

The presence of ferromagnetic or ferrimagnetic nanoparticles in the interstellar medium would give rise to magnetic dipole radiation at microwave and submillimeter frequencies. Such grains may account for the strong millimeter-wavelength emission observed from a number of low-metallicity galaxies, including the Small Magellanic Cloud. We calculate the absorption and scattering cross sections for such grains, with particular attention to metallic Fe, magnetite Fe{sub 3}O{sub 4}, and maghemite {gamma}-Fe{sub 2}O{sub 3}, all potentially present in the interstellar medium. The rate of Davis-Greenstein alignment by magnetic dissipation is also estimated. We determine the temperature of free-flying magnetic grains heated by starlight and calculate the polarization of the magnetic dipole emission from both free-fliers and inclusions. For inclusions, the magnetic dipole emission is expected to be polarized orthogonally relative to the normal electric dipole radiation. Magnetic dipole radiation will contribute significantly to the 20-40 GHz anomalous microwave emission only if a large fraction of the Fe is in metallic Fe iron nanoparticles with extreme elongations. Finally, we present self-consistent dielectric functions for metallic Fe, magnetite Fe{sub 3}O{sub 4}, and maghemite {gamma}-Fe{sub 2}O{sub 3}, enabling calculation of absorption and scattering cross sections from microwave to X-ray wavelengths.
Bridging Soft-Hard Transport Properties of Quark-Gluon Plasmas with CUJET3.0

A new model (CUJET3.0) of jet quenching in nuclear collisions coupled to bulk data constrained (VISH2+1D) viscous hydrodynamic backgrounds is constructed by generalizing the perturbative QCD based (CUJET2.0) model to include two complementary non-perturbative chromodynamical features of the QCD con_nement cross-over phase transition near Tc ≈ 160 MeV: (1) the suppression of quark and gluon chromo-electric-charged (cec) degrees of freedom and (2) the emergence of chromo-magnetic-monopole (cmm) degrees of freedom. Such a semi Quark Gluon Monopole Plasma (sQGMP) microscopic scenario is tested by comparing predictions of the leading hadron nuclear modification factors, R (pT > 10GeV=c; $$ \sqrt{s} $$ ), and their azimuthal elliptic asymmetry v 2 (pT > 10GeV=c; $$ \sqrt{s} $$ ) with available data on h =π, D;B jet fragments from nuclear collisions at RHIC ( $$ \sqrt{s} = 0.2 $$ ATeV) and LHC( $$ \sqrt{s}=2.76 $$ ATeV). The cmm degrees of freedom in the sQGMP model near T c are shown to solve robustly the long standing R AA vs v 2 puzzle by predicting a maximum of the jet quenching parameter field ĝ(E; T)/T 3 near T c . The robustness of CUJET3.0 model to a number of theoretical uncertainties is critically tested. Moreover the consistency of jet quenching with observed bulk perfect uidity is demonstrated by extrapolating the sQGMP $$ \widehat{q} $$ down to thermal energy E ~ 3T scales and showing that the sQGMP shear viscosity to entropy density ratio $$ \eta /s\approx {T}^3/\widehat{q} $$ falls close to the unitarity bound, 1/4 $$ \pi $$ , in the range (1–2)Tc. Detailed comparisons of the CUJET2.0 and CUJET3.0 models reveal the fact that remarkably different $$ \widehat{q}(T) $$ dependence could be consistent with the same R AA data and could only be distinguished by anisotropy observables. These _ndings demonstrate clearly the inadequacy of focusing on the jet path averaged quantity $$ \left\langle \widehat{q}\right\rangle $$ as the only relevant medium property to characterize jet quenching, and point to the crucial roles of other essential factors beyond just the $$ \left\langle \widehat{q}\right\rangle $$ , such as the chromo electric and magnetic composition of the plasma, the screening masses and the running couplings at multiple scales which all strongly influence jet energy loss.
Constraints on Supernova Kicks from the Double Neutron Star System PSR B1913+16

We use recent information on geodetic precession of the binary pulsar B1913+16 along with measurements of its orbital parameters and proper motion to derive new constraints on the immediate progenitor of this double neutron star system. As part of our analysis, we model the motion of the binary in the Galaxy after the second supernova explosion, and we derive constraints on the unknown radial velocity. We also obtain limits on the magnitude and direction of the kick velocity imparted to the pulsar companion during the second supernova explosion. We consider the complete set of possible cases, depending on the kinematic age of the system and the 180° ambiguity in the pulsar spin orientation. Most interestingly, we find that the natal kick must have been directed almost perpendicular to the spin axis of the neutron star progenitor, independent of the specific presupernova configuration. Such a tight constraint on the kick direction has important implications for the physical mechanism responsible for the kick.
Network Community Detection on Small Quantum Computers

In recent years a number of quantum computing devices with small numbers of qubits became available. We present a hybrid quantum local search (QLS) approach that combines a classical machine and a small quantum device to solve problems of practical size. The proposed approach is applied to the network community detection problem. QLS is hardware-agnostic and easily extendable to new quantum computing devices as they become available. We demonstrate it to solve the 2-community detection problem on graphs of size up to 410 vertices using the 16-qubit IBM quantum computer and D-Wave 2000Q, and compare their performance with the optimal solutions. Our results demonstrate that QLS perform similarly in terms of quality of the solution and the number of iterations to convergence on both types of quantum computers and it is capable of achieving results comparable to state-of-the-art solvers in terms of quality of the solution including reaching the optimal solutions.
Weak Gravitational Lensing of High-Redshift 21 cm Power Spectra

We describe the effects of weak gravitational lensing by cosmological large-scale structure on the diffuse emission of 21 cm radiation from high-redshift neutral hydrogen during the era of reionization. The ability to observe three-dimensional information suggests that 21 cm studies may provide a useful context for weak-lensing studies. We focus on the gravitational lensing effects on both the angular power spectra and the intrinsic, three-dimensional power spectra. We present a new approach for calculating the weak-lensing signature that reduces to coupled systems of differential equations in a lensing cutoff scale, which are solved by approximating the magnification matrix. This method is applied to reionization models of the 21 cm background spectra up to small angular scales over a range in redshift. The effect on the angular power spectrum is typically less than 1% on small angular scales, and very small on scales corresponding to the feature imprinted by reionization bubbles, due to the near-scale invariance of the 21 cm angular power spectrum on these scales. We describe the expected effect of weak lensing on three-dimensional 21 cm power spectra, and show that lensing creates aspherical perturbations to the intrinsic power spectrum that depend on the polar angle of the wavevector. The effect on the three-dimensional power spectrum is less than 1% on scales k 0.1 h Mpc-1, but can be 1% for highly inclined modes for k 1 h Mpc-1. The angular variation of the lensing effect on these scales is well described by a quartic polynomial in the cosine of the polar angle. The detection of the gravitational lensing effects on 21 cm power spectra will require very sensitive, high-resolution observations by future low-frequency radio arrays.
Fusion Rules for the Virasoro Algebra of Central Charge 25

Let $\mathcal {F}_{25}$ be the family of irreducible lowest weight modules for the Virasoro algebra of central charge 25 which are not isomorphic to Verma modules. Let L(25,0) be the Virasoro vertex operator algebra of central charge 25. We prove that the fusion rules for the L(25,0)-modules in $\mathcal {F}_{25}$ are in correspondence with the tensor rules for the irreducible finite dimensional representations of $sl(2, \mathbb {C})$ , extending the known correspondence between modules for the Virasoro algebras of dual central charges 1 and 25.
Quantifying Density Fluctuations in Volumes of All Shapes and Sizes Using Indirect Umbrella Sampling

Water density fluctuations are an important statistical mechanical observable that is related to many-body correlations, as well as hydrophobic hydration and interactions. Local water density fluctuations at a solid-water surface have also been proposed as a measure of it's hydrophobicity. These fluctuations can be quantified by calculating the probability, P(v)(N), of observing N waters in a probe volume of interest v. When v is large, calculating P(v)(N) using molecular dynamics simulations is challenging, as the probability of observing very few waters is exponentially small, and the standard procedure for overcoming this problem (umbrella sampling in N) leads to undesirable impulsive forces. Patel et al. [J. Phys. Chem. B, 114, 1632 (2010)] have recently developed an indirect umbrella sampling (INDUS) method, that samples a coarse-grained particle number to obtain P(v)(N) in cuboidal volumes. Here, we present and demonstrate an extension of that approach to volumes of other basic shapes, like spheres and cylinders, as well as to collections of such volumes. We further describe the implementation of INDUS in the NPT ensemble and calculate P(v)(N) distributions over a broad range of pressures. Our method may be of particular interest in characterizing the hydrophobicity of interfaces of proteins, nanotubes and related systems.
Anabelian geometry and descent obstructions on moduli spaces

In this talk we study the section conjecture of anabelian geometry and the sufficiency of the finite descent obstruction to the Hasse principle for the moduli spaces of principally polarized abelian varieties and of curves over number fields. For the former we show that both the section conjecture and the finite descent obstruction fail in a very controlled way. For the latter, we prove some partial results that indicate that the finite descent obstruction suffices. We also show how this sufficiency implies the same for all hyperbolic curves. 3 Anabelian geometry Grothendieck’s anabelian program: The class of “anabelian” varieties can be recovered from their etale fundamental group plus Galois action of the absolute Galois group of the ground field. Problem: Which varieties are “anabelian”? Hyperbolic curves are anabelian. What else?
Link invariants of finite type and perturbation theory

The Vassiliev-Gusarov link invariants of finite type are known to be closely related to perturbation theory for Chern-Simons theory. In order to clarify the perturbative nature of such link invariants, we introduce an algebra V x containing elements g i satisfying the usual braid group relations and elements a i satisfying g i−g infi sup-1 =ea i, where e is a formal variable that may be regarded as measuring the failure of g infi sup2 to equal 1. Topologically, the elements a i signify intersections. We show that a large class of link invariants of finite type are in one-to-one correspondence with homogeneous Markov traces on V x. We sketch a possible application of link invariants of finite type to a manifestly diffeomorphisminvariant perturbation theory for quantum gravity in the loop representation.
Depth of $F$-singularities and base change of relative canonical sheaves

Reference EPFL-ARTICLE-231108doi:10.1017/S1474748013000066 URL: http://dx.doi.org/10.1017/S1474748013000066 Record created on 2017-09-19, modified on 2017-09-19
Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions

The effect of interfacial slip on steady-state and time-periodic flows of monatomic liquids is investigated using non-equilibrium molecular dynamics simulations. The fluid phase is confined between atomically smooth rigid walls, and the fluid flows are induced by moving one of the walls. In steady shear flows, the slip length increases almost linearly with shear rate. We found that the velocity profiles in oscillatory flows are well described by the Stokes flow solution with the slip length that depends on the local shear rate. Interestingly, the rate dependence of the slip length obtained in steady shear flows is recovered when the slip length in oscillatory flows is plotted as a function of the local shear rate magnitude. For both types of flows, the friction coefficient at the liquid–solid interface correlates well with the structure of the first fluid layer near the solid wall.
The Future of Compute: How the Data Transformation is Reshaping VLSI

The digital transformation continues to gain momentum, as businesses offer consumers increasingly distributed services, and industry pursues improvements across the extent of the electronics ecosystem. This transformation is characterized by continued strong demand for compute at all points in the network - at the core, the edge, and at the endpoints. Data continues to grow at an exponential rate and not only drives the compute requirements, but also requires efficient solutions for movement and storage of data that is critical for overall performance. From device to cloud, new applications and use cases are continuously emerging. This transformation demands that we adapt our thinking and move from a hardware/program centric to a data/information centric approach, and to embrace new ways to compute. To keep pace in this dynamic environment, Moore's Law and its impact have become more relevant than ever. The continued scaling of dimensions, materials and devices drives a renewed focus on the fundamental physics of devices and materials, while novel architecture schemes and system design innovation motivate a more comprehensive understanding of large-scale integration at all levels of the system.
Are granulins copper sequestering proteins

Granulins (GRN 1-7) are short (~6 kDa), cysteine-rich proteins that are generated upon the proteolytic processing of progranulin (PGRN). These peptides, along with their precursor, have been implicated in multiple pathophysiological roles, especially in neurodegenerative diseases. Previously we showed that GRN-3 and GRN-5 are fully disordered in the reduced form implicating redox sensitive attributes to the proteins. Redox-based modulations are often carried out by metalloproteins in mitigating oxidative stress and maintaining metal-homeostasis within cells. To probe whether GRNs play a role in metal sequestration, we tested the metal binding propensity of the reduced forms of GRNs -3 and - 5 under neutral and acidic pH mimicking cytosolic and lysosomal conditions, respectively. We found, at neutral pH, both GRNs selectively bind Cu and no other divalent metal cations, with a greater specificity for Cu(I). Binding of Cu did not result in a disorder-to-order structural transition but partly triggered the multimerization of GRNs via uncoordinated cystines at both pH conditions. Overall, the results indicate that GRNs -3 and - 5 have surprisingly strong affinity for Cu in the pM range, comparable to other known copper sequestering proteins. The results also hint at a potential of GRNs to reduce Cu(II) to Cu(I), a process that has significance in mitigating Cu-induced ROS cytotoxicity in cells. Together, this report uncovers metal-coordinating property of GRNs for the first time, which may have profound significance in their structure and pathophysiological functions.
Phased: Phase-Aware Submodularity-Based Energy Disaggregation

Energy disaggregation is the task of discerning the energy consumption of individual appliances from aggregated measurements, which holds promise for understanding and reducing energy usage. In this paper, we propose PHASED, an optimization approach for energy disaggregation that has two key features: PHASED (i) exploits the structure of power distribution systems to make use of readily available measurements that are neglected by existing methods, and (ii) poses the problem as a minimization of a difference of sub-modular functions. We leverage this form by applying a discrete optimization variant of the majorization-minimization algorithm to iteratively minimize a sequence of global upper bounds of the cost function to obtain high-quality approximate solutions. PHASED improves the disaggregation accuracy of state-of-the-art models by up to 61% and achieves better prediction on heavy load appliances.
A Behavioral Cascade of HIV Seroadaptation Among US Men Who Have Sex with Men in the Era of PrEP and U = U

Seroadaptive behaviors help reduce HIV risk for some men who have sex with men (MSM), and have been well documented across MSM populations. Advancements in biomedical prevention have changed the contexts in which seroadaptive behaviors occur. We thus sought to estimate and compare the prevalence of four stages of the "seroadaptive cascade" by PrEP use in the recent era: knowledge of own serostatus, knowledge of partner serostatus; serosorting (matching by status), and condomless anal intercourse. Serosorting overall appeared to remain common, especially with casual and one-time partners. Although PrEP use did not impact status discussion, it did impact serosorting and the likelihood of having condomless anal intercourse. For respondents not diagnosed with HIV and not on PrEP, condomless anal intercourse occurred in just over half of relationships with HIV-positive partners who were not on treatment. Biomedical prevention has intertwined with rather than supplanted seroadaptive behaviors, while contexts involving neither persist.
Casimir force on a light front

Abstract Depending on the point of view, the Casimir force arises from variation in the energy of the quantum vacuum as boundary conditions are altered or as an interaction between atoms in the materials that form these boundary conditions. Standard analyses of such configurations are usually done in terms of ordinary, equal-time (Minkowski) coordinates. However, physics is independent of the coordinate choice, and an analysis based on light-front coordinates, where x + ≡ t + z ∕ c plays the role of time, is equally valid. After a brief historical introduction, we illustrate and compare equal-time and light-front calculations of the Casimir force.
Helium and neon isotopes in stratospheric particles

— Helium and neon isotope ratios were determined for 16 interplanetary dust particles (IDPs) collected in the stratosphere. The concentration of helium observed varied greatly from particle to particle, with the highest values approaching those found for lunar surface fines and some gas-rich meteorites. With the exception of one particle, for which the 3He/4He was (1.45 ± 0.05) × 10−3, the remainder of the particles had ratios falling between 1.4 and 3.1 × 10−4, with an average of (2.4 ± 0.3) × 10−4, substantially less than is associated with the solar wind or observed in average lunar fines or in lunar fines having sizes comparable to those of the IDPs studied. The average 20Ne/22Ne found was 12.0 ± 0.5. Only three reasonably reliable 21Ne/22Ne ratios could be determined, and for these the average was 0.035 ± 0.006. The isotopic ratios appear to preclude the presence of any appreciable amount of cosmic ray-produced spallogenic products. The high 4He concentrations observed for some of the particles, approaching those observed for lunar surface grains, suggest they were not heated to high temperatures and degassed as they descended in the earth's atmosphere. From Flynn's study of the dynamics of IDPs entering the earth's atmosphere this could mean they entered the atmosphere at relatively low velocities, and hence may be primarily of asteroidal rather than cometary origin.
Piecewise visual, linearly connected metrics on boundaries of relatively hyperbolic groups

Suppose a finitely generated group G is hyperbolic relative to &#x1d4ab; a set of proper finitely generated subgroups of G. Established results in the literature imply that a “visual” metric on ∂(G,&#x1d4ab;) is “...
Unsupervised Sketch to Photo Synthesis.

Humans can envision a realistic photo given a free-hand sketch that is not only spatially imprecise and geometrically distorted but also without colors and visual details. We study unsupervised sketch to photo synthesis for the first time, learning from unpaired sketch and photo data where the target photo for a sketch is unknown during training. Existing works only deal with either style difference or spatial deformation alone, synthesizing photos from edge-aligned line drawings or transforming shapes within the same modality, e.g., color images.
Generating EEG features from Acoustic features

In this paper we demonstrate predicting electroencephalography (EEG) features from acoustic features using recurrent neural network (RNN) based regression model and generative adversarial network (GAN). We predict various types of EEG features from acoustic features. We compare our results with the previously studied problem on speech synthesis using EEG and our results demonstrate that EEG features can be generated from acoustic features with lower root mean square error (RMSE), normalized RMSE values compared to generating acoustic features from EEG features (ie: speech synthesis using EEG) when tested using the same data sets.
Deep Learning Predictive Band Switching in Wireless Networks

In cellular systems, the user equipment (UE) can request a change in the frequency band when its rate drops below a threshold on the current band. The UE is then instructed by the base station (BS) to measure the quality of candidate bands, which requires a measurement gap in the data transmission, thus lowering the data rate. We propose an online-learning based band switching approach that does not require any measurement gap. Our proposed classifier-based band switching policy instead exploits spatial and spectral correlation between radio frequency signals in different bands based on knowledge of the UE location. We focus on switching between a lower (e.g., 3.5 GHz) band and a millimeter wave band (e.g., 28 GHz), and design and evaluate two classification models that are trained on a ray-tracing dataset. A key insight is that measurement gaps are overkill, in that only the relative order of the bands is necessary for band selection, rather than a full channel estimate. Our proposed machine learning-based policies achieve roughly 30% improvement in mean effective rates over those of the industry standard policy, while achieving misclassification errors well below 0.5% and maintaining resilience against blockage uncertainty.
Distributed Optimization Using Reduced Network Equivalents for Radial Power Distribution Systems

The limitations of centralized optimization methods for power systems operation have led to the distributed computing paradigm, particularly in power distribution systems. The existing techniques reported in recent literature for solving distributed optimization problems are not viable for power distribution systems applications. The essential drawback remains a large number of required communication rounds, i.e., macro-iterations among the computing agents to solve one instance of the optimization problem; the typical number of macro-iterations are in the order of $10^2\sim 10^3$ . In this paper, a new and scalable distributed optimization method based on Equivalent Network Approximation (ENApp) is proposed to solve optimal power flow (OPF) for a balanced radial distribution system. Specifically, the distribution system's radial topology is leveraged to reduce the decomposed systems into upstream and downstream network equivalents. The proposed innovations reduce the required number of macro-iterations/communication-rounds for convergence by order of magnitude. The approach is validated using IEEE 123-bus and IEEE 8500-node test systems and is shown to converge to the same optimal solution as obtained using an equivalent centralized OPF (C-OPF) model.
Friedman’s plucking model: New international evidence from Maddison Project data

Abstract Milton Friedman’s plucking model of business cycles hypothesizes that deeper recessions forecast larger booms while stronger booms do not necessarily forecast deeper recessions. While most previous past empirical work is limited to post-war data in the US, this paper tests the plucking model using Maddison Project growth data for 169 countries across several centuries. We find that the plucking property is broadly evident across time and countries. Plucking is particularly strong in advanced economies in East Asia (Japan), Europe (Western Europe) and North America (US and Canada) while to a lesser extent elsewhere in emerging economies. The overall strength of the plucking property globally also appears to have increased during the 20th century with the rise of widespread industrialized economies.
End-to-end nanophotonic inverse design for imaging and polarimetry

By co-designing a meta-optical front end in conjunction with an image-processing back end, we demonstrate noise sensitivity and compactness substantially superior to either an optics-only or a computation-only approach, illustrated by two examples: subwavelength imaging and reconstruction of the full polarization coherence matrices of multiple light sources. Our end-to-end inverse designs couple the solution of the full Maxwell equations---exploiting all aspects of wave physics arising in subwavelength scatterers---with inverse-scattering algorithms in a single large-scale optimization involving $\gtrsim 10^4$ degrees of freedom. The resulting structures scatter light in a way that is radically different from either a conventional lens or a random microstructure, and suppress the noise sensitivity of the inverse-scattering computation by several orders of magnitude. Incorporating the full wave physics is especially crucial for detecting spectral and polarization information that is discarded by geometric optics and scalar diffraction theory.
Privacy, Neuroscience, and Neuro-Surveillance

The beliefs, feelings, and thoughts that make up our streams of consciousness would seem to be inherently private. Nevertheless, modern neuroscience is offering to open up the sanctity of this domain to outside viewing. A common retort often voiced to this worry is something like, ‘Privacy is difficult to define and has no inherent moral value. What’s so great about privacy?’ In this article I will argue against these sentiments. A definition of privacy is offered along with an account of why privacy is morally valuable. In the remaining sections, several privacy protecting principles are defended that would limit various sorts of neuro-surveillance promised by advancements in neuroscience.
Health Insurance Eligibility, Utilization of Medical Care, and Child Health

Two economists applied data from the Current Population Survey and the National Health Interview Survey and state-level data on child mortality to a simulation model of utilization of medical care that varies only with the states legislative environment to examine the utilization of medical care and health effects of Medicaid eligibility on low income children. The models took into consideration the recent expansions of Medicaid to low income children. 38% of those ineligible for Medicaid in 1984 who became eligible due to changes during 1984-1992 were uninsured. Between 1984 and 1992 expansions of the Medicaid program increased the proportion of children eligible for Medicaid almost two-fold (16.1% vs. 31.2%); yet coverage rates were always lower than eligibility rates (13.2% vs. 16.1% in 1984 and 20.3% vs. 31.2% in 1992) and the increase in coverage rates was only about 50% of the increase in eligibility rates. During 1984-1992 the probability that a child was eligible for Medicaid increased the probability of health insurance coverage by 29.77%. When the model considered bias in variables (e.g. a recession in a state) the take-up rate was only 22.73%. Nevertheless Medicaid markedly increased use of medical care. For example eligibility for Medicaid increased the likelihood of making a visit to a physicians office in the last two weeks by about 50%. It also increased the probability of a child visiting the hospital suggesting inefficiency in the way that providers deliver care to Medicaid enrollees. Medicaid eligibility had a significant effect on reducing child mortality. The 15.1 percentage point increase in eligibility during 1984-1992 reduced child mortality by 4.5%. When the researchers examined parent-assessed subjective health measures Medicaid eligibility had no effect on child health. Medicaid eligibility reduced race and education-based disparities in the number of visits and racial differences in mortality; yet it may actually intensify current disparities in health care delivery site.
Optimal Lending Contracts and Firm Dynamics

We develop a general model of lending in the presence of endogenous borrowing constraints. Borrowing constraints arise because borrowers face limited liability and debt repayment cannot be perfectly enforced. In the model, the dynamics of debt are closely linked with the dynamics of borrowing constraints. In fact, borrowing constraints must satisfy a dynamic consistency requirement: the value of outstanding debt restricts current access to short-term capital, but is itself determined by future access to credit. This dynamic consistency is not guaranteed in models of exogenous borrowing constraints, where the ability to raise short-term capital is limited by some prespecified function of debt. We characterize the optimal default-free contract—which minimizes borrowing constraints at all histories—and derive implications for firm growth, survival, leverage and debt maturity. The model is qualitatively consistent with stylized facts on the growth and survival of firms. Comparative statics with respect to technology and default constraints are derived. Borrowing constraints are an important determinant of firm growth and survival. 1 Such constraints may arise in connection to the financing of investment opportunities faced by firms or temporary liquidity needs, such as those required to survive a recession. This paper develops a theory of endogenous borrowing constraints and studies its implications for firm dynamics. In our model, debt is constrained by the firm’s limited liability and option to default. A lending contract specifies an initial loan size, future financing, and a repayment schedule. The choice of these variables in turn determines future growth, the firm’s future borrowing capacity, and its ability and willingness to repay. Hence, borrowing constraints and firm dynamics are jointly determined. We study this dynamic design problem. Our model builds on Thomas and Worral’s (1994) model of foreign direct investment. At time zero a risk neutral borrower (firm or entrepreneur) has a project which requires a fixed initial set-up cost. Every period the project yields revenues that increase with the amount of 1. There is considerable evidence suggesting that financing constraints are important determinants of firm dynamics. Gertler and Gilchrist (1994) argue that liquidity constraints may explain why small manufacturing firms respond more to a tightening of monetary policy than do larger manufacturing firms. Perez-Quiros and Timmermann (2000) show that in recessions smaller firms are more sensitive to the worsening of credit market conditions as measured by higher interest rates and default premia. Evans and Jovanovic (1989) show that the liquidity constraints are essential in the decision to become an entrepreneur. Fazzari, Hubbard and Petersen (1988), among others, view financial constraints as an explanation for the dynamic behaviour of aggregate investment, and Cabral and Mata (1996) are able to fit reasonably well the size distribution of Portuguese manufacturing firms by estimating a simple model of financing constraints. For surveys see Hubbard (1998) and Stein (2003).