cssi/SciSciGPT-SciSciNet huggingface dataset:
Age-Dependent Assessment of Genes Involved in Cellular Senescence, Telomere, and Mitochondrial Pathways in Human Lung Tissue of Smokers, COPD, and IPF: Associations With SARS-CoV-2 COVID-19 ACE2-TMPRSS2-Furin-DPP4 Axis

Background: Aging is one of the key contributing factors for chronic obstructive pulmonary diseases (COPD) and other chronic inflammatory lung diseases. Here we determined how aging contributes to the altered gene expression related to mitochondrial function, cellular senescence, and telomeric length processes that play an important role in the progression of COPD and idiopathic pulmonary fibrosis (IPF). Methods: Total RNA from the human lung tissues of non-smokers, smokers, and patients with COPD and IPF were processed and analyzed using a Nanostring platform based on their ages (younger: 55 yrs). Results: Several genes were differentially expressed in younger and older smokers, and patients with COPD and IPF compared to non-smokers which were part of the mitochondrial biogenesis/function (HSPD1, FEN1, COX18, COX10, UCP2 & 3), cellular senescence (PCNA, PTEN, KLOTHO, CDKN1C, TNKS2, NFATC1 & 2, GADD45A), and telomere replication/maintenance (PARP1, SIRT6, NBN, TERT, RAD17, SLX4, HAT1) target genes. Interestingly, NOX4 and TNKS2 were increased in the young IPF as compared to the young COPD patients. Genes in the mitochondrial dynamics and quality control mechanisms like FIS1 and RHOT2 were decreased in young IPF compared to their age matched COPD subjects. ERCC1 and GADD45B were higher in young COPD as compared to IPF. Aging plays an important role in various infectious diseases including the SARS-CoV-2 infection. Lung immunoblot analysis of smokers, COPD and IPF subjects revealed increased abundance of proteases and receptor/spike protein like TMPRSS2, furin and DPP4 in association with a slight increase in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor ACE2 levels. Conclusions: Overall, these findings suggest that altered transcription of target genes that regulate mitochondrial function, cellular senescence, and telomere attrition in the pathobiology of lung aging in COPD and IPF in associated with alterations in SARS-CoV-2 ACE2-TMPRSS2-Furin-DPP4 axis as pharmacological targets for COVID-19.
The association of weather, temperature, and holidays on pediatric maxillofacial trauma.

Objective To evaluate the association of weather, seasons, months and holidays on the frequency and pattern of pediatric facial fractures. Methods Retrospective review of pediatric patients treated for facial fractures at two Level I trauma centers in a midsize Midwestern US city over a 5-year period. Patients were included only if presentation was within 3 hours of inciting trauma, transfers from other facilities were excluded. Demographic characteristics, fracture patterns, operative interventions, weather data, and local public school schedules were acquired and associations were analyzed with unpaired t tests, χ2, multivariate and binomial regression model analyses. Results Two hundred and sixty patients were included. The average age (SD) was 11.8 (5.0) years, with 173 males and 87 females. The highest distribution of presentations occurred in the summer season (35.0%), on weekends and holidays (58.1%), and when the weather was described as clear (48.5%). The most common mechanisms of injury were motor vehicle collisions (25.8%), followed by sports-(21.5%) and assault-(16.5%) related injuries. Mechanisms were significantly associated with certain fracture patterns. Older age was associated with fewer orbital fractures (P < .01). Seventy-five patients (28.8%) required operative intervention. Age was found to impact the likelihood of operative intervention (Exp(β) = 1.081, P = .03) while weather, temperature, and mechanism did not. Conclusion Pediatric facial fractures are linked to warmer weather with clear skies and warmer season. Age predicts some fracture patterns and need for operative intervention. These results can be used to inform public health interventions, policymaking, and trauma staffing.Level of Evidence: Level 2b (retrospective cohort).
Avian Pathogenic Escherichia coli and Clostridium perfringens : Challenges in No Antibiotics Ever Broiler Production and Potential Solutions

United States is the largest producer and the second largest exporter of broiler meat in the world. In the US, broiler production is largely converting to antibiotic-free programs which has caused an increase in morbidity and mortality within broiler farms. Escherichia coli and Clostridium perfringens are two important pathogenic bacteria readily found in the broiler environment and result in annual billion-dollar losses from colibacillosis, gangrenous dermatitis, and necrotic enteritis. The broiler industry is in search of non-antibiotic alternatives including novel vaccines, prebiotics, probiotics, and housing management strategies to mitigate production losses due to these diseases. This review provides an overview of the broiler industry and antibiotic free production, current challenges, and emerging research on antibiotic alternatives to reduce pathogenic microbial presence and improve bird health.
Sars-Cov-2 Spike Protein Induces Cellular Changes in Primitive and Mature Hematopoietic Cells

The devastating effects of SARS-CoV-2 infection (which causes COVID-19) highlight the need for a deeper understanding of the virus, host response, and the tissues affected by infection, including the hematopoietic stem cells (HSC), hematopoietic progenitors (HPC), and more mature blood cells including immune cells. While other coronavirus infections have been associated with hematopoietic or immune cell complications (Chu et al., J Infect Dis 2016), the effects of SARS-CoV-2 infection on HSC/HPC and mature immune cells are not yet understood. We performed studies to examine the potential susceptibility of HSC/HPC subpopulations and immune cells to infection and functional studies to explore if exposure to SARS-CoV-2 proteins impacts these cells. The most well-studied receptor for SARS-CoV-2 is ACE2 (Hoffmann et al., Cell 2020), a cell surface protein to which SARS-CoV-2 spike protein (S protein) binds to facilitate viral entry to host cells. We explored expression of ACE2 in primitive and mature blood cells. We demonstrated using RT-qPCR as well as western blotting that ACE2 is expressed at both the mRNA and protein levels in pooled low-density peripheral blood cells (PB) from healthy donors (n=5); pooled CD34+ cells from cord blood (CB) enriched for HSC/HPC (n=7); lineage+ (lin+) low density CB cells (n=7), and high density polymorphonuclear leukocytes (PMN) from CB (n=3). We then determined ACE2 expression on specific subpopulations of HSC/HPC and immune cells. Flow cytometry analysis (FACS) demonstrated that ACE2 is expressed on the cell surface of small subpopulations of PB immune cells, including 1-2% of T-cells, 2-4% of B-cells, and Disclosures No relevant conflicts of interest to declare.
Mixing Times for the Commuting Chain on CA Groups

Let G be a finite group. The commuting chain on G moves from an element x to y by selecting y uniformly amongst those which commute with x. The t-step transition probabilities of this chain converge to a distribution uniform on the conjugacy classes of G. We provide upper and lower bounds for the mixing time of this chain on a CA group (groups with a “nice” commuting structure) and show that cutoff does not occur for many of these chains. We also provide a formula for the characteristic polynomial of the transition matrix of this chain. We apply our general results to explicitly study the chain on several sequences of groups, such as general linear groups, Heisenberg groups, and dihedral groups. The commuting chain is a specific case of a more general family of chains known as Burnside processes. Few instances of the Burnside processes have permitted careful analysis of mixing. We present some of the first results on mixing for the Burnside process where the state space is not fully specified (i.e., not for a particular group). Our upper bound shows our chain is rapidly mixing, a topic of interest for Burnside processes.
Magnetorotational-instability-driven Accretion in Protoplanetary Disks

Non-ideal MHD effects play an important role in the gas dynamics in protoplanetary disks (PPDs). This paper addresses the influence of non-ideal MHD effects on the magnetorotational instability (MRI) and angular momentum transport in PPDs using the most up-to-date results from numerical simulations. We perform chemistry calculations using a complex reaction network with standard prescriptions for X-ray and cosmic-ray ionizations. We first show that whether or not grains are included, the recombination time is at least one order of magnitude less than the orbital time within five disk scale heights, justifying the validity of local ionization equilibrium and strong coupling limit in PPDs. The full conductivity tensor at different disk radii and heights is evaluated, with the MRI active region determined by requiring that (1) the Ohmic Elsasser number {Lambda} be greater than 1 and (2) the ratio of gas to magnetic pressure {beta} be greater than {beta}{sub min}(Am) as identified in the recent study by Bai and Stone, where Am is the Elsasser number for ambipolar diffusion. With full flexibility as to the magnetic field strength, we provide a general framework for estimating the MRI-driven accretion rate M-dot and the magnetic field strength in the MRI active layer. Wemore » find that the MRI active layer always exists at any disk radius as long as the magnetic field in PPDs is sufficiently weak. However, the optimistically predicted M-dot in the inner disk (r = 1-10 AU) appears insufficient to account for the observed range of accretion rates in PPDs (around 10{sup -8} M{sub sun} yr{sup -1}) even in the grain-free calculation, and the presence of solar abundance sub-micron grains further reduces M-dot by one to two orders of magnitude. Moreover, we find that the predicted M-dot increases with radius in the inner disk where accretion is layered, which would lead to runaway mass accumulation if disk accretion is solely driven by the MRI. Our results suggest that stronger sources of ionization and/or additional mechanisms such as magnetized wind are needed to explain the observed accretion rates in PPDs. In contrast, our predicted M-dot is on the order of 10{sup -9} M{sub sun} yr{sup -1} in the outer disk, consistent with the observed accretion rates in transitional disks.« less
Non-simply-connected gauge groups and rational points on elliptic curves

We consider the F-theory description of non-simply-connected gauge groups appearing in the E8 × E8 heterotic string. The analysis is closely tied to the arithmetic of torsion points on an elliptic curve. The general form of the corresponding elliptic fibration is given for all finite subgroups of E8 which are applicable in this context. We also study the closely-related question of point-like instantons on a K3 surface whose holonomy is a finite group. As an example we consider the case of the heterotic string on a K3 surface having the E8 gauge symmetry broken to SU(9)/3 or (E6 × SU(3))/3 by point-like instantons with 3 holonomy.
Quasi-states, quasi-morphisms, and the moment map

We prove that symplectic quasi-states and quasi-morphisms on a symplectic manifold descend under symplectic reduction on a superheavy level set of a Hamiltonian torus action. Using a construction due to Abreu and Macarini, in each dimension at least four we produce a closed symplectic toric manifold with infinite dimensional spaces of symplectic quasi-states and quasi-morphisms, and a one-parameter family of non-displaceable Lagrangian tori. By using McDuff's method of probes, we also show how Ostrover and Tyomkin's method for finding distinct spectral quasi-states in symplectic toric Fano manifolds can also be used to find different superheavy toric fibers.
Carbon and Oxygen in Nearby Stars: Keys to Protoplanetary Disk Chemistry

We present carbon and oxygen abundances for 941 FGK stars—the largest such catalog to date. We find that planet-bearing systems are enriched in these elements. We self-consistently measure NC /NO , which is thought to play a key role in planet formation. We identify 46 stars with NC /NO ≥ 1.00 as potential hosts of carbon-dominated exoplanets. We measure a downward trend in [O/Fe] versus [Fe/H] and find distinct trends in the thin and thick disks, supporting the work of Bensby et al. Finally, we measure sub-solar NC /NO = 0.40+0.11 – 0.07, for WASP-12, a surprising result as this star is host to a transiting hot Jupiter whose dayside atmosphere was recently reported to have NC /NO ≥ 1 by Madhusudhan et al. Our measurements are based on 15,000 high signal-to-noise spectra taken with the Keck 1 telescope as part of the California Planet Search. We derive abundances from the [O I] and C I absorption lines at λ = 6300 and 6587 A using the SME spectral synthesizer.
A- and B-exciton photoluminescence intensity ratio as a measure of sample quality for transition metal dichalcogenide monolayers

The photoluminescence (PL) in monolayer transition metal dichalcogenides (TMDs) is dominated by the recombination of electrons in the conduction band with holes in the spin-orbit split valence bands, and there are two distinct emission features referred to as the A-peak (ground state exciton) and B-peak (higher spin-orbit split state). The intensity ratio of these two features varies widely, and several contradictory interpretations have been reported. In this work, we analyze the room temperature PL from MoS2, MoSe2, WS2, and WSe2 monolayers and identify the underlying cause of observed variations in emission profile. We determine that PL variations arise from differences in the non-radiative recombination associated with defect densities. Therefore, the relative intensities of the A- and B-emission features can be used to qualitatively assess the non-radiative recombination and a low B/A ratio is indicative of low defect density and high sample quality. We also performed polarization-resolved PL measurements. Emission from TMD monolayers is governed by unique optical selection rules which make them promising materials for valleytronic operations. We observe a notably higher valley polarization in the B-exciton relative to the A-exciton. The high polarization is a consequence of the shorter B-exciton lifetime resulting from rapid relaxation of excitons from the B-exciton to the A-exciton of the valence band. Our work clarifies disparities reported in the literature relating to the emission profile and provides a straightforward means to assess sample quality.
THE ONSET OF SPIRAL STRUCTURE IN THE UNIVERSE

The onset of spiral structure in galaxies appears to occur between redshifts 1.4 and 1.8 when disks have developed a cool stellar component, rotation dominates over turbulent motions in the gas, and massive clumps become less frequent. During the transition from clumpy to spiral disks, two unusual types of spirals are found in the Hubble Ultra Deep Field that are massive, clumpy, and irregular like their predecessor clumpy disks, yet spiral-like or sheared like their descendants. One type is woolly with massive clumpy arms all over the disk and is brighter than other disk galaxies at the same redshift, while another type has irregular multiple arms with high pitch angles, star formation knots, and no inner symmetry like today's multiple-arm galaxies. The common types of spirals seen locally are also present in a redshift range around z ~ 1, namely grand design with two symmetric arms, multiple arm with symmetry in the inner parts and several long, thin arms in the outer parts, and flocculent, with short, irregular, and patchy arms that are mostly from star formation. Normal multiple-arm galaxies are found only closer than z ~ 0.6 in the Ultra Deep Field. Grand design galaxies extend furthest to z ~ 1.8, presumably because interactions can drive a two-arm spiral in a disk that would otherwise have a more irregular structure. The difference between these types is understandable in terms of the usual stability parameters for gas and stars, and the ratio of the velocity dispersion to rotation speed.
A new method for calculating the primordial bispectrum in the squeezed limit

In 2004, Creminelli and Zaldarriaga proposed a consistency relation for the primordial curvature perturbation of all single-field inflation models; it related the bispectrum in the squeezed limit to the spectral tilt. We have developed a technique, based in part on the Creminelli and Zaldarriaga argument, that can greatly simplify the calculation of the squeezed-limit bispectrum using the in-in formalism; we were able to arrive at a generic formula that does not rely on a slow-roll approximation. Using our formula, we explicitly tested the consistency relation for power-law inflation and for an exactly scale-invariant model by Starobinsky; for the latter model, Creminelli and Zaldarriaga's argument predicts a vanishing bispectrum whereas our quantum calculation shows a non-zero bispectrum that approaches zero in the long-wavelength limit and for inflation with a large number of e-folds.
Natural commuting of vanishing cycles and the Verdier dual

We prove that the shifted vanishing cycles and nearby cycles commute with Verdier dualizing up to a natural isomorphism, even when the coefficients are not in a field.
VisionISP: Repurposing the Image Signal Processor for Computer Vision Applications

Traditional image signal processors (ISPs) are primarily designed and optimized to improve the image quality perceived by humans. However, optimal perceptual image quality does not always translate into optimal performance for computer vision applications. We propose a set of methods, which we collectively call VisionISP, to re-purpose the ISP for machine consumption. VisionISP significantly reduces data transmission needs by reducing the bit-depth and resolution while preserving the relevant information. The blocks in VisionISP are simple, content-aware, and trainable. Experimental results show that VisionISP boosts the performance of a subsequent computer vision system trained to detect objects in an autonomous driving setting. The results demonstrate the potential and the practicality of VisionISP for computer vision applications.
A tale of two Liouville closures

An $H$-field is a type of ordered valued differential field with a natural interaction between ordering, valuation, and derivation. The main examples are Hardy fields and fields of transseries. Aschenbrenner and van den Dries proved in~\cite{MZ} that every $H$-field $K$ has either exactly one or exactly two Liouville closures up to isomorphism over $K$, but the precise dividing line between these two cases was unknown. We prove here that this dividing line is determined by $\uplambda$-freeness, a property of $H$-fields that prevents certain deviant behavior. In particular, we show that under certain types of extensions related to adjoining integrals and exponential integrals, the property of $\uplambda$-freeness is preserved. In the proofs we introduce a new technique for studying $H$-fields, the \emph{yardstick argument} which involves the rate of growth of pseudoconvergence.
Cluster Cosmology with the Velocity Distribution Function of the HECS-SZ Sample

We apply the Velocity Distribution Function (VDF) to a sample of Sunyaev-Zel'dovich (SZ)-selected clusters, and we report preliminary cosmological constraints in the $\sigma_8$-$\Omega_m$ cosmological parameter space. The VDF is a forward-modeled test statistic that can be used to constrain cosmological models directly from galaxy cluster dynamical observations. The method was introduced in Ntampaka et al. (2017) and employs line-of-sight velocity measurements to directly constrain cosmological parameters; it is less sensitive to measurement error than a standard halo mass function approach. The method is applied to the Hectospec Survey of Sunyaev-Zeldovich-Selected Clusters (HeCS-SZ) sample, which is a spectroscopic follow up of a Planck-selected sample of 83 galaxy clusters. Credible regions are calculated by comparing the VDF of the observed cluster sample to that of mock observations, yielding $\mathcal{S}_8 \equiv \sigma_8 \left(\Omega_m/0.3\right)^{0.25} = 0.751\pm0.037$. These constraints are in tension with the Planck Cosmic Microwave Background (CMB) TT fiducial value, which lies outside of our 95% credible region, but are in agreement with some recent analyses of large scale structure that observe fewer massive clusters than are predicted by the Planck fiducial cosmological parameters.
The Dynamics of Message Passing on Dense Graphs, with Applications to Compressed Sensing

“Approximate message passing” (AMP) algorithms have proved to be effective in reconstructing sparse signals from a small number of incoherent linear measurements. Extensive numerical experiments further showed that their dynamics is accurately tracked by a simple one-dimensional iteration termed state evolution. In this paper, we provide rigorous foundation to state evolution. We prove that indeed it holds asymptotically in the large system limit for sensing matrices with independent and identically distributed Gaussian entries. While our focus is on message passing algorithms for compressed sensing, the analysis extends beyond this setting, to a general class of algorithms on dense graphs. In this context, state evolution plays the role that density evolution has for sparse graphs. The proof technique is fundamentally different from the standard approach to density evolution, in that it copes with a large number of short cycles in the underlying factor graph. It relies instead on a conditioning technique recently developed by Erwin Bolthausen in the context of spin glass theory.
Landau ordering phase transitions beyond the Landau paradigm

Continuous phase transitions associated with the onset of a spontaneously broken symmetry are thought to be successfully described by the Landau-Ginzburg-Wilson-Fisher theory of fluctuating order parameters. In this work, we show that such transitions can admit new universality classes which cannot be understood in terms of a theory of order parameter fluctuations. We explicitly demonstrate continuous time reversal symmetry breaking quantum phase transitions of 3+1-D bosonic systems described by critical theories expressed in terms of a deconfined gauge theory with massless Dirac fermions instead of the fluctuating Ising order parameter. We dub such phase transitions “Landau transitions beyond Landau description” (LBL). A key feature of our examples is that the stability of the LBL fixed points requires a crucial global symmetry, which is nonanomalous, unbroken, and renders no symmetry protected topological phase throughout the phase diagram. Despite this, there are elementary critical fluctuations of the phase transition that transform projectively under this symmetry group. We also construct examples of other novel quantum critical phenomena, notably a continuous Landau-forbidden deconfined critical point between two Landau-allowed phases in 3+1-D.
Does Scope of Practice Affect Mobility of Nurse Practitioners Serving Medicare Beneficiaries

The shortage of nurse practitioners in the United States has broadly decreased access, decreased quality, and increased care costs. In some states, policymakers are trying to address such shortages by expanding nurse practitioners’ scope of practice or extending autonomy for nurses to order tests, prescribe medications, diagnose patients, and initiate and manage treatments. We exploit the state-level variations in the nurse practitioner’s scope of practice laws to estimate the impact on the mobility decisions of the nurse who serve Medicare beneficiaries. We identify nurse’s practice locations from 2013 to 2017 by gleaning their National Provider Identifiers from Part D Prescriber Public Use File data. We find that nurses in full-practice states are 0.41 percent less likely to move out of the state compared to nurses in restrictive-practice states. Also, nurses who move are 5.70 percent more likely to move to full-practice states than restrictive-practice states. Our estimates demonstrate nurses’ preference for practicing in states with the full scope of practice.
Testing Gaugino Mass Unification Directly at the LHC

We report on the first step of a systematic study of how gaugino mass unification can be probed at the CERN LHC in a quasi-model independent manner. Here we focus our attention on the theoretically well-motivated mirage pattern of gaugino masses, a one-parameter family of models of which universal (high scale) gaugino masses are a limiting case. Using a statistical method to optimize our signature selection we arrive at three ensembles of observables targeted at the physics of the gaugino sector, allowing for a determination of this non-universality parameter without reconstructing individual mass eigenvalues or the soft supersymmetry-breaking gaugino masses themselves. In this controlled environment we find that approximately 80% of the supersymmetric parameter space would give rise to a model for which our method will detect non-universality in the gaugino mass sector at the 10% level with O ( 10 fb − 1 ) of integrated luminosity.
On the K-Theoretic Hall Algebra of a Surface

In this paper, we define the $K$-theoretic Hall algebra for $0$-dimensional coherent sheaves on a smooth projective surface, prove that the algebra is associative and construct a homomorphism to a redefined shuffle algebra analogous to Negut.
Galactic Cosmic Ray Origins and OB Associations: Evidence from SuperTIGER Observations of Elements _(26)Fe through _(40)Zr

We report abundances of elements from _(26)Fe to _(40)Zr in the cosmic radiation measured by the SuperTIGER (Trans-Iron Galactic Element Recorder) instrument during 55 days of exposure on a long-duration balloon flight over Antarctica. These observations resolve elemental abundances in this charge range with single-element resolution and good statistics. These results support a model of cosmic ray origin in which the source material consists of a mixture of 19_(-6^(+11)% material from massive stars and ~81% normal interstellar medium material with solar system abundances. The results also show a preferential acceleration of refractory elements (found in interstellar dust grains) by a factor of ~4 over volatile elements (found in interstellar gas) ordered by atomic mass (A). Both the refractory and volatile elements show a mass-dependent enhancement with similar slopes.
Evaluating Rapid Application Development with Python for Heterogeneous Processor-Based FPGAs

As modern FPGAs evolve to include more heterogeneous processing elements, such as ARM cores, it makes sense to consider these devices as processors first and FPGA accelerators second. As such, the conventional FPGA development environment must also adapt to support more software-like programming functionality. While high-level synthesis tools can help reduce FPGA development time, there still remains a large expertise gap in order to realize highly performing implementations. At a system-level the skill set necessary to integrate multiple custom IP hardware cores, interconnects, memory interfaces, and now heterogeneous processing elements is complex. Rather than drive FPGA development from the hardware up, we consider the impact of leveraging Python to accelerate application development. Python offers highly optimized libraries from an incredibly large developer community, yet is limited to the performance of the hardware system. In this work we evaluate the impact of using PYNQ, a Python development environment for application development on the Xilinx Zynq devices, the performance implications, and bottlenecks associated with it. We compare our results against existing C-based and hand-coded implementations to better understand if Python can be the glue that binds together software and hardware developers.
The physical mechanism behind M dwarf metallicity indicators and the role of C and O abundances

We present NIR synthetic spectra based on PHOENIX stellar atmosphere models of typical early and mid M dwarfs with varied C and O abundances. We apply multiple recently published methods for determining M dwarf metallicity to our models to determine the effect of C and O abundances on metallicity indicators. We find that the pseudo-continuum level is very sensitive to C/O and that all metallicity indicators show a dependence on C and O abundances, especially in lower Teff models. In some cases the inferred metallicity ranges over a full order of magnitude (>1 dex) when [C/Fe] and [O/Fe] are varied independently by +/-0.2. We also find that [(O-C)/Fe], the difference in O and C abundances, is a better tracer of the pseudo-continuum level than C/O. Models of mid-M dwarfs with [C/Fe], [O/Fe], and [M/H] that are realistic in the context of galactic chemical evolution suggest that variation in [(O-C)/Fe] is the primary physical mechanism behind the M dwarf metallicity tracers investigated here. Empirically calibrated metallicity indicators are still valid for most nearby M dwarfs due to the tight correlation between [(O-C)/Fe] and [Fe/H] evident in spectroscopic surveys of solar neighborhood FGK stars. Variations in C and O abundances also affect the spectral energy distribution of M dwarfs. Allowing [O/Fe] to be a free parameter provides better agreement between synthetic spectra and observed spectra of metal-rich M dwarfs. We suggest that flux-calibrated, low-resolution, NIR spectra can provide a path toward measuring C and O abundances in M dwarfs and breaking the degeneracy between C/O and [Fe/H] present in M dwarf metallicity indicators.
Winning Arguments: Interaction Dynamics and Persuasion Strategies in Good-faith Online Discussions

Changing someone's opinion is arguably one of the most important challenges of social interaction. The underlying process proves difficult to study: it is hard to know how someone's opinions are formed and whether and how someone's views shift. Fortunately, ChangeMyView, an active community on Reddit, provides a platform where users present their own opinions and reasoning, invite others to contest them, and acknowledge when the ensuing discussions change their original views. In this work, we study these interactions to understand the mechanisms behind persuasion. We find that persuasive arguments are characterized by interesting patterns of interaction dynamics, such as participant entry-order and degree of back-and-forth exchange. Furthermore, by comparing similar counterarguments to the same opinion, we show that language factors play an essential role. In particular, the interplay between the language of the opinion holder and that of the counterargument provides highly predictive cues of persuasiveness. Finally, since even in this favorable setting people may not be persuaded, we investigate the problem of determining whether someone's opinion is susceptible to being changed at all. For this more difficult task, we show that stylistic choices in how the opinion is expressed carry predictive power.
On the Age of the TRAPPIST-1 System

The nearby (d = 12 pc) M8 dwarf star TRAPPIST-1 (2MASS J23062928-0502285) hosts a compact system of at least seven exoplanets with sizes similar to Earth. Given its importance for testing planet formation and evolution theories, and for assessing the prospects for habitability among Earth-size exoplanets orbiting the most common type of star in the Galaxy, we present a comprehensive assessment of the age of this system. We collate empirical age constraints based on the color-absolute magnitude diagram, average density, lithium absorption, surface gravity features, metallicity, kinematics, rotation, and magnetic activity; and conclude that TRAPPIST-1 is a transitional thin/thick disk star with an age of 7.6$\pm$2.2 Gyr. The star's color-magnitude position is consistent with it being slightly metal-rich ([Fe/H] $\simeq$ +0.06), in line with its previously reported near-infrared spectroscopic metallicity; and it has a radius (R = 0.121$\pm$0.003 R$_{\odot}$) that is larger by 8-14% compared to solar-metallicity evolutionary models. We discuss some implications of the old age of this system with regard to the stability and habitability of its planets.
Exact solutions and physical analogies for unidirectional flows

Following Stokes' ``extremely easy'' solution for Poiseuille flow in a circular pipe, Saint-Venant solved the analogous problem of beam torsion for arbitrary shapes. This paper explains the mathematics of unidirectional flow and applies it to some new problems, extending the number of analogies to seventeen.
Unitary conjugation channels with continuous random phases

We consider unitary conjugation channels with continuous random phases. The spectral properties of the channel average are examined, thereby the asymptotic behaviors of the repeated quantum interactions of the motion are derived. We then study the channels with uniformly distributed continuous phases on an interval. In this context, it is shown that discrete phases are sufficient to achieve the channel average.
Heegaard Floer homology of spatial graphs

We extend the theory of combinatorial link Floer homology to a class of oriented spatial graphs called transverse spatial graphs. To do this, we define the notion of a grid diagram representing a transverse spatial graph, which we call a graph grid diagram. We prove that two graph grid diagrams representing the same transverse spatial graph are related by a sequence of graph grid moves, generalizing the work of Cromwell for links. For a graph grid diagram representing a transverse spatial graph f : G → S3, we define a relatively bigraded chain complex (which is a module over a multivariable polynomial ring) and show that its homology is preserved under the graph grid moves; hence it is an invariant of the transverse spatial graph. In fact, we define both a minus and hat version. Taking the graded Euler characteristic of the homology of the hat version gives an Alexander type polynomial for the transverse spatial graph. Specifically, for each transverse spatial graph f, we define a balanced sutured manifold (S3 ∖ f(G),γ(f)). We show that the graded Euler characteristic is the same as the torsion of (S3 ∖ f(G),γ(f)) defined by S Friedl, A Juhasz, and J Rasmussen.
lp-Recovery of the Most Significant Subspace among Multiple Subspaces with Outliers

We assume data sampled from a mixture of $$d$$ -dimensional linear subspaces with spherically symmetric distributions within each subspace and an additional outlier component with spherically symmetric distribution within the ambient space (for simplicity, we may assume that all distributions are uniform on their corresponding unit spheres). We also assume mixture weights for the different components. We say that one of the underlying subspaces of the model is most significant if its mixture weight is higher than the sum of the mixture weights of all other subspaces. We study the recovery of the most significant subspace by minimizing the $$l_p$$ -averaged distances of data points from $$d$$ -dimensional subspaces of $$\mathbb R^D$$ , where $$0 < p \in \mathbb R$$ . Unlike other $$l_p$$ minimization problems, this minimization is nonconvex for all $$p>0$$ and thus requires different methods for its analysis. We show that if $$0<p \le 1$$ , then for any fraction of outliers, the most significant subspace can be recovered by $$l_p$$ minimization with overwhelming probability (which depends on the generating distribution and its parameters). We show that when adding small noise around the underlying subspaces, the most significant subspace can be nearly recovered by $$l_p$$ minimization for any $$0<p \le 1$$ with an error proportional to the noise level. On the other hand, if $$p>1$$ and there is more than one underlying subspace, then with overwhelming probability the most significant subspace cannot be recovered or nearly recovered. This last result does not require spherically symmetric outliers.
What is 3C 324

We report ground based and HST observations of the z=1.206 radio galaxy 3C 324, a prototypical example of the radio-optical ``alignment effect.'' While infrared images shows a simple, round object reminiscent of a giant elliptical galaxy, the HST images reveal a spectacular, linear chain of UV-bright subcomponents closely aligned with the radio axis. In light of the available data, we consider various scenarios to explain the properties of 3C 324, as well as evidence for the presence of dust which may obscure the central active nucleus and scatter its light to produce the polarized, aligned continuum seen in the rest-frame UV.
ResilientDB: global scale resilient blockchain fabric

Recent developments in blockchain technology have inspired innovative new designs in resilient distributed and database systems. At their core, these blockchain applications typically use Byzantine fault-tolerant consensus protocols to maintain a common state across all replicas, even if some replicas are faulty or malicious. Unfortunately, existing consensus protocols are not designed to deal with geo-scale deployments in which many replicas spread across a geographically large area participate in consensus.To address this, we present the Geo-Scale Byzantine Fault-Tolerant consensus protocol (GeoBFT). GeoBFT is designed for excellent scalability by using a topological-aware grouping of replicas in local clusters, by introducing parallelization of consensus at the local level, and by minimizing communication between clusters. To validate our vision of high-performance geo-scale resilient distributed systems, we implement GeoBFT in our efficient ResilientDB permissioned blockchain fabric. We show that GeoBFT is not only sound and provides great scalability, but also outperforms state-of-the-art consensus protocols by a factor of six in geo-scale deployments.
Endurance-write-speed tradeoffs in nonvolatile memories

We derive phenomenological model for endurance-write time switching tradeoff for nonvolatile memories with thermally activated switching mechanisms. The model predicts linear to cubic dependence of endurance on write time for metal oxide memristors and flash memories, which is partially supported by experimental data for the breakdown of metal oxide thin films.
Secondary characteristic classes of surface bundles

The Miller–Morita–Mumford classes associate to an oriented surface bundle E! B a class i.E/ 2H .BIZ/ . It was proved in [1] that the mod p reduction i.E/ 2 H .BIZ=p/ vanishes when i C 1 is divisible by .p 1/ . In this note we prove that the p reduction i.E/ 2H .BIZ=p/ vanishes when i C 1 is divisible by p.p 1/ . We also define for each integer i 1 a characteristic class i.E/ 2 H 2i.p 1/ .BIZ=p/ which satisfies p i.E/D i.p 1/ 1.E/ 2H .BIZ=p/ .
THE CORONAL SOURCE OF EXTREME-ULTRAVIOLET LINE PROFILE ASYMMETRIES IN SOLAR ACTIVE REGION OUTFLOWS

High-resolution spectra from the Hinode EUV Imaging Spectrometer have revealed that coronal spectral line profiles are sometimes asymmetric, with a faint enhancement in the blue wing on the order of 100 km s{sup -1}. These asymmetries could be important since they may be subtle yet diagnostically useful signatures of coronal heating or solar wind acceleration processes. It has also been suggested that they are signatures of chromospheric jets supplying mass and energy to the corona. Until now, however, there have been no studies of the physical properties of the plasma producing the asymmetries. Here we identify regions of asymmetric profiles in the outflows of AR 10978 using an asymmetric Gaussian function and extract the intensities of the faint component using multiple Gaussian fits. We then derive the temperature structure and chemical composition of the plasma producing the asymmetries. We find that the asymmetries are dependent on temperature, and are clearer and stronger in coronal lines. The temperature distribution peaks around 1.4-1.8 MK with an emission measure at least an order of magnitude larger than that at 0.6 MK. The first ionization potential bias is found to be 3-5, implying that the high-speed component of the outflows may also contribute to more » the slow-speed wind. Observations and models indicate that it takes time for plasma to evolve to a coronal composition, suggesting that the material is trapped on closed loops before escaping, perhaps by interchange reconnection. The results, therefore, identify the plasma producing the asymmetries as having a coronal origin. « less
Monopole annihilation in cosmic necklaces

A sequence of two symmetry breaking transitions in the early universe may produce monopoles whose flux is confined into two strings each, which thus assemble into ``necklaces'' with monopoles as beads. Such ``cosmic necklaces'' have been proposed as a source of ultra-high-energy cosmic rays. We analyze the evolution of these systems and show that essentially all monopoles annihilate or leave the string at early times, after which cosmic necklaces evolve in a similar way to a network of ordinary cosmic strings. We investigate several modifications to the basic picture, but in nearly all cases we find that too few monopoles remain on the necklaces to produce any observable cosmic rays. There may be a small window for superconducting condensates to prevent annihilations, but only if both the string and the condensate scale are very high.
A Century of gravity: 1901 - 2000 (plus some 2001)

This lecture consists of two parts. The first is a (totally unsystematic) survey of some of the high points in the evolution of gravity and its successors, primarily in the course of the past century. The second summarizes some new work on surprising properties of higher (> 1) spin fields in cosmological backgrounds: the presence of Λ gives rise to discrete sets of massive models endowed with gauge invariances, that divide the (m2, Λ) plane into unitary and non-unitary phases. The unitary region common to fermions and bosons shrinks to flat space (Λ → 0) as their spins increase.
Network assembly of scientific communities of varying size and specificity

Abstract How does the collaboration network of researchers coalesce around a scientific topic? What sort of social restructuring occurs as a new field develops? Previous empirical explorations of these questions have examined the evolution of co-authorship networks associated with several fields of science, each noting a characteristic shift in network structure as fields develop. Historically, however, such studies have tended to rely on manually annotated datasets and therefore only consider a handful of disciplines, calling into question the universality of the observed structural signature. To overcome this limitation and test the robustness of this phenomenon, we use a comprehensive dataset of over 189,000 scientific articles and develop a framework for partitioning articles and their authors into coherent, semantically related groups representing scientific fields of varying size and specificity. We then use the resulting population of fields to study the structure of evolving co-authorship networks. Consistent with earlier findings, we observe a global topological transition as the co-authorship networks coalesce from a disjointed aggregate into a dense giant connected component that dominates the network. We validate these results using a separate, complimentary corpus of scientific articles, and, overall, we find that the previously reported characteristic structural evolution of a scientific field's associated co-authorship network is robust across a large number of scientific fields of varying size, scope, and specificity. Additionally, the framework developed in this study may be used in other scientometric contexts in order to extend studies to compare across a larger range of scientific disciplines.
Low-damping sub-10-nm thin films of lutetium iron garnet grown by molecular-beam epitaxy

We analyze the structural and magnetic characteristics of (111)-oriented lutetium iron garnet (Lu3Fe5O12) films grown by molecular-beam epitaxy, for films as thin as 2.8 nm. Thickness-dependent measurements of the in- and out-of-plane ferromagnetic resonance allow us to quantify the effects of two-magnon scattering, along with the surface anisotropy and the saturation magnetization. We achieve effective damping coefficients of 11.1(9)×10−4 for 5.3 nm films and 32(3)×10−4 for 2.8 nm films, among the lowest values reported to date for any insulating ferrimagnetic sample of comparable thickness.
Finetuned Cancellations and Improbable Theories

It is argued that the $$x-y$$ cancellation model (XYCM) is a good proxy for discussions of finetuned cancellations in physical theories. XYCM is then analyzed from a statistical perspective, where it is argued that a finetuned point in the parameter space is not abnormal, with any such point being just as probable as any other point. However, landing inside a standardly defined finetuned region (i.e., the full parameter space of finetuned points) has a much lower probability than landing outside the region, and that probability is invariant under assumed ranges of parameters. This proposition requires asserting also that the finetuned target region is a priori established. Therefore, it is surmised that a highly finetuned theory (i.e., remaining parameter space is finetuned) is generally expected to be highly improbable. An actionable implication of this moderate naturalness position is that the search for a non-finetuned explanation to supplant an apparently finetuned theory is likely to be a valid pursuit, but not guaranteed to be. A statistical characterization of this moderate position is presented, as well as those of the extreme pro-naturalness and anti-naturalness positions.
Optimal Local Well-Posedness for the Periodic Derivative Nonlinear Schrödinger Equation

We prove local well-posedness for the periodic derivative nonlinear Schrodinger equation, which is $$L^2$$ critical, in Fourier-Lebesgue spaces which scale like $${H}^s({\mathbb {T}})$$ for $$s>0$$ . Our result is optimal in the sense that it covers the full subcritical regime. In particular we close the existing gap in the subcritical theory by improving the result of Grunrock and Herr (SIAM J Math Anal 39(6):1890–1920, 2008), which established local well-posedness in Fourier-Lebesgue spaces which scale like $${H}^s({\mathbb {T}})$$ for $$s >\frac{1}{4}$$ . We achieve this result by a delicate analysis of the structure of the solution and the construction of an adapted nonlinear submanifold of a suitable function space. Together these allow us to construct the unique solution to the given subcritical data. This constructive procedure is inspired by the theory of para-controlled distributions developed by Gubinelli et al. (Forum Math Pi, 3:75, 2015) and Catellier and Chouk (Ann Probab 46(5):2621–2679, 2018) in the context of stochastic PDE. Our proof and results however, are purely deterministic.
Proof simplification and automated theorem proving

The proofs first generated by automated theorem provers are far from optimal by any measure of simplicity. In this paper, I describe a technique for simplifying automated proofs. Hopefully, this discussion will stimulate interest in the larger, still open, question of what reasonable measures of proof simplicity might be. This article is part of the theme issue 'The notion of 'simple proof' - Hilbert's 24th problem'.
Stability of pulsar rotational and orbital periods

Millisecond and binary pulsars are the most stable astronomical standards of frequency. They can be applied to solving a number of problems in astronomy and time-keeping metrology including the search for a stochastic gravitational wave background in the early universe, testing general relativity, and establishing a new time-scale. The full exploration of pulsar properties requires that proper unbiased estimates of spin and orbital parameters of the pulsar be obtained. These estimates depend essentially on the random noise components present in pulsar timing residuals. The instrumental white noise has predictable statistical properties and makes no harm for interpretation of timing observations, while the astrophysical/geophysical low-frequency noise corrupts them, thus, reducing the quality of tests of general relativity and decreasing the stability of the pulsar time scale.