cssi/SciSciGPT-SciSciNet huggingface dataset:
Enhanced harmonic generation in gases using an all-dielectric metasurface

Strong field-confinement, long-lifetime resonances, and slow-light effects suggest that meta surfaces are a promising tool for nonlinear optical applications. These nanostructured devices have been utilized for relatively high efficiency solid-state high-harmonic generation platforms, four-wave mixing, and Raman scattering experiments, among others. Here we report the first all-dielectric metasurface to enhance harmonic generation from a surrounding gas, achieving as much as a factor of 45 increase in the overall yield for Argon atoms. When compared to metal nanostructures, dielectrics are more robust against damage for high power applications such as those using atomic gases. We employ dimerized high-contrast gratings fabricated in silicon-on-insulator that support bound states in the continuum, a resonance feature accessible in broken-symmetry planar devices. Our 1D gratings maintain large mode volumes, overcoming one of the more severe limitations of earlier device designs and greatly contributing to enhanced third- and fifth- harmonic generation. The interaction lengths that can be achieved are also significantly greater than the 10's of nm to which earlier solid-state designs were restricted. We perform finite-difference time-domain simulations to fully characterize the wavelength, linewidth, mode profile, and polarization dependence of the resonances. Our experiments confirm these predictions and are consistent with other nonlinear optical properties. The tunable wavelength dependence and quality-factor control we demonstrate in these devices make them an attractive tool for the next generation of high-harmonic sources, which are anticipated to be pumped at longer wavelengths and with lower peak power, higher repetition rate lasers.
Visualizing dissipative charge-carrier dynamics at the nanoscale with superconducting-charge-qubit microscopy

The author proposes scanning charge qubit microscopy as a way to visualize dissipative charge carrier dynamics in low-dimensional quantum materials.
STAMP: a multiplex sequencing method for simultaneous evaluation of mitochondrial DNA heteroplasmies and content

Human mitochondrial genome (mtDNA) variations, such as mtDNA heteroplasmies (the co-existence of mutated and wild-type mtDNA), have received increasing attention in recent years for their clinical relevance to numerous diseases. But large-scale population studies of mtDNA heteroplasmies have been lagging due to the lack of a labor- and cost-effective method. Here, we present a novel human mtDNA sequencing method called STAMP (sequencing by targeted amplification of multiplex probes) for measuring mtDNA heteroplasmies and content in a streamlined workflow. We show that STAMP has high-mapping rates to mtDNA, deep coverage of unique reads and high tolerance to sequencing and polymerase chain reaction errors when applied to human samples. STAMP also has high sensitivity and low false positive rates in identifying artificial mtDNA variants at fractions as low as 0.5% in genomic DNA samples. We further extend STAMP, by including nuclear DNA-targeting probes, to enable assessment of relative mtDNA content in the same assay. The high cost-effectiveness of STAMP, along with the flexibility of using it for measuring various aspects of mtDNA variations, will accelerate the research of mtDNA heteroplasmies and content in large population cohorts, and in the context of human diseases and aging.
Noninvasive Ultrasonic Glymphatic Induction Enhances Intrathecal Drug Delivery

Summary Intrathecal drug delivery is routinely used to bypass the blood-brain barrier in treating varied central nervous system conditions. However, the utility of intrathecal delivery is limited by poor parenchymal uptake of agents from the cerebrospinal fluid. We demonstrate that a simple noninvasive transcranial ultrasound protocol significantly increases the brain parenchymal uptake of intrathecally administered drugs and antibodies. Essentially, we show that our protocol of transcranial ultrasound can accelerate glymphatic fluid transport from the cisternal space into the parenchymal compartment. Specifically, we administered small (∼1kDa) and large (∼150 kDa) molecule agents into the cisterna magna of rats and then applied low, diagnostic-intensity focused ultrasound in a scanning protocol throughout the brain. Using both real-time magnetic resonance imaging and ex vivo histologic analyses, we observed significantly increased uptake of each agent into the brain parenchyma from the cisternal cerebrospinal fluid, notably with no brain parenchymal damage. The low intensity of the ultrasound and its noninvasiveness underscores the ready path to clinical translation of this technique for whole-brain delivery of a variety of agents. Furthermore, this technique can be used as a means to probe the causal role of the glymphatic system in the variety of disease and physiologic processes to which it has been correlated. eTOC Summary A translation-ready ultrasound technique enhances the brain penetration of intrathecally delivered agents via upregulating the glymphatic pathway.
An approach for long-term, multi-probe Neuropixels recordings in unrestrained rats

The use of Neuropixels probes for chronic neural recordings is in its infancy and initial studies leave questions about long-term stability and probe reusability unaddressed. Here, we demonstrate a new approach for chronic Neuropixels recordings over a period of months in freely moving rats. Our approach allows multiple probes per rat and multiple cycles of probe reuse. We found that hundreds of units could be recorded for multiple months, but that yields depended systematically on anatomical position. Explanted probes displayed a small increase in noise compared to unimplanted probes, but this was insufficient to impair future single-unit recordings. We conclude that cost-effective, multi-region, and multi-probe Neuropixels recordings can be carried out with high yields over multiple months in rats or other similarly sized animals. Our methods and observations may facilitate the standardization of chronic recording from Neuropixels probes in freely moving animals.
Efficient Knowledge Graph Validation via Cross-Graph Representation Learning

Recent advances in information extraction have motivated the automatic construction of huge Knowledge Graphs (KGs) by mining from large-scale text corpus. However, noisy facts are unavoidably introduced into KGs that could be caused by automatic extraction. To validate the correctness of facts (i.e., triplets) inside a KG, one possible approach is to map the triplets into vector representations by capturing the semantic meanings of facts. Although many representation learning approaches have been developed for knowledge graphs, these methods are not effective for validation. They usually assume that facts are correct, and thus may overfit noisy facts and fail to detect such facts. Towards effective KG validation, we propose to leverage an external human-curated KG as auxiliary information source to help detect the errors in a target KG. The external KG is built upon human-curated knowledge repositories and tends to have high precision. On the other hand, although the target KG built by information extraction from texts has low precision, it can cover new or domain-specific facts that are not in any human-curated repositories. To leverage external KG for validation, one intuitive approach is to find matched triplets between the target KG and the external KG. However, this approach can only apply to the small portion of triplets that are covered by both external and target KGs and is not useful for the validation of majority of the triplets. To tackle this challenging task, we propose a cross-graph representation learning framework, i.e., CrossVal, which can leverage an external KG to validate the facts in the target KG efficiently. This is achieved by embedding triplets based on their semantic meanings, drawing cross-KG negative samples and estimating a confidence score for each triplet based on its degree of correctness. We evaluate the proposed framework on datasets across different domains. Experimental results show that the proposed framework achieves the best performance compared with the state-of-the-art methods on large-scale KGs.
Computability, orders, and solvable groups

The main objective of this paper is the following two results. (1) There exists a computable bi-orderable group that does not have a computable bi-ordering; (2) there exists a bi-orderable, two-generated computably presented solvable group with undecidable word problem. Both of the groups can be found among two-generated solvable groups of derived length .(1) [a]nswers a question posed by Downey and Kurtz; (2) answers a question posed by Bludov and Glass in Kourovka Notebook.One of the technical tools used to obtain the main results is a computational extension of an embedding theorem of B. Neumann that was studied by the author earlier. In this paper we also compliment that result and derive new corollaries that might be of independent interest.
Contextual cueing in preview search

Frequently finding a target in the same location within a familiar context reduces search time, relative to search for objects appearing in novel contexts. This learned association between a context and a target location requires several blocks of training and has long-term effects. Short-term selection history also influences search, where previewing a subset of a search context shortly before the appearance of the target and remaining distractors speeds search. Here we explored the interactions between contextual cueing and preview benefit using a modified version of a paradigm from Hodsoll and Humphreys (Journal of Experimental Psychology: Human Perception and Performance, 31(6), 1346–1358, 2005). Participants searched for a T target among L distractors. Half of the distractors appeared 800 ms before the addition of the other distractors and the target. We independently manipulated the repetition of the previewed distractors and the newly added distractors. Though the previewed set never contained the target, repetition of either the previewed or the newly added context yielded contextual cueing, and the effect was greater when the previewed context repeated. Another experiment trained participants to associate the previewed context with a target location, then disrupted the association in a testing phase. This disruption eliminated contextual cueing, suggesting that learning of the previewed context was associative. These findings demonstrate an important interaction between distinct kinds of selection history effects.
Design and characteristics of a WEP test in a sounding-rocket payload

We describe SR-POEM, a Galilean test of the weak equivalence principle that is to be conducted during the free fall portion of the flight of a sounding rocket payload. This test of a single pair of substances will have a measurement uncertainty of σ(η) < 2×10−17 after averaging the results of eight separate drops, each of 120 s duration. The entire payload is inverted between successive drops to cancel potential sources of systematic error. The weak equivalence principle measurement is made with a set of four of the SAO laser gauges, which have achieved an Allan deviation of 0.04 pm for an averaging time of 30 s. We discuss aspects of the current design with an emphasis on those that bear on the accuracy of the determination of η. The discovery of a violation(η ≠ 0) would have profound implications for physics, astrophysics and cosmology.
Test ideals of non-principal ideals: Computations, Jumping Numbers, Alterations and Division Theorems

Abstract Given an ideal a ⊆ R in a (log) Q -Gorenstein F-finite ring of characteristic p > 0 , we study and provide a new perspective on the test ideal τ ( R , a t ) for a real number t > 0 . Generalizing a number of known results from the principal case, we show how to effectively compute the test ideal and also describe τ ( R , a t ) using (regular) alterations with a formula analogous to that of multiplier ideals in characteristic zero. We further prove that the F-jumping numbers of τ ( R , a t ) as t varies are rational and have no limit points, including the important case where R is a formal power series ring. Additionally, we obtain a global division theorem for test ideals related to results of Ein and Lazarsfeld from characteristic zero, and also recover a new proof of Skoda's theorem for test ideals which directly mimics the proof for multiplier ideals.
Stability and Hydrolyzation of Metal Organic Frameworks with Paddle-Wheel SBUs upon Hydration

Instability of most prototypical metal organic frameworks (MOFs) in the presence of moisture is always a limitation for industrial scale development. In this work, we examine the dissociation mechanism of microporous paddle wheel frameworks M(bdc)(ted)0.5 [M = Cu, Zn, Ni, Co; bdc = 1,4-benzenedicarboxylate; ted = triethylenediamine] in controlled humidity environments. Combined in situ IR spectroscopy, Raman, and Powder X-ray diffraction measurements show that the stability and modification of isostructual M(bdc)(ted)0.5 compounds upon exposure to water vapor critically depend on the central metal ion. A hydrolysis reaction of water molecules with Cu–O–C is observed in the case of Cu(bdc)(ted)0.5. Displacement reactions of ted linkers by water molecules are identified with Zn(bdc)(ted)0.5 and Co(bdc)(ted)0.5. In contrast,. Ni(bdc)(ted)0.5 is less susceptible to reaction with water vapors than the other three compounds. In addition, the condensation of water vapors into the framework is necessary to initia...
Direct Determination of the HF/H2 Abundance Ratio in Interstellar Gas

We report the first detection of the v = 1-0, R(0) ro-vibrational transition of HF at 2.499385 ?m arising from interstellar gas. The line is seen in absorption toward three background sources?HD 154368, Elias 29, and AFGL 2136 IRS 1?all of which have reported H2 column densities determined from observations of H2. This allows for the first direct determination of the HF/H2 abundance ratio. We find values of N(HF)/N(H2) = 1.15 ? 10?8 and 0.69 ? 10?8 for HD 154368 and Elias 29, respectively. The sight line toward AFGL 2136 IRS 1 also shows absorption from the v = 1-0, R(1) transition of HF, indicating warm, dense (n H 109?cm?3) gas, likely very close to the central protostar. Ascribing portions of the HF absorption to warm and cold gas, we find N(HF)/N(H2) = (1.7-2.9) ? 10?8 and (0.33-0.58) ? 10?8 for the two components, respectively. Except for the warm component toward AFGL 2136 IRS 1, all observed HF/H2 ratios are well below N(HF)/N(H2) = 3.6 ? 10?8, the value predicted if nearly all gas phase fluorine is in the form of HF. Models of fluorine chemistry that account for depletion onto grains are able to reproduce the results toward HD 154368, but not in the cold, dense gas toward AFGL 2136 IRS 1 and Elias 29. Most likely, some combinations of simplifying assumptions made in the chemical models are responsible for these discrepancies.
TIME-DEPENDENT TURBULENT HEATING OF OPEN FLUX TUBES IN THE CHROMOSPHERE, CORONA, AND SOLAR WIND

We investigate several key questions of plasma heating in open-field regions of the corona that connect to the solar wind. We present results for a model of Alfven-wave-driven turbulence for three typical open magnetic field structures: a polar coronal hole, an open flux tube neighboring an equatorial streamer, and an open flux tube near a strong-field active region. We compare time-steady, one-dimensional turbulent heating models against fully time-dependent three-dimensional reduced-magnetohydrodynamic modeling of BRAID. We find that the time-steady results agree well with time-averaged results from BRAID. The time dependence allows us to investigate the variability of the magnetic fluctuations and of the heating in the corona. The high-frequency tail of the power spectrum of fluctuations forms a power law whose exponent varies with height, and we discuss the possible physical explanation for this behavior. The variability in the heating rate is bursty and nanoflare-like in nature, and we analyze the amount of energy lost via dissipative heating in transient events throughout the simulation. The average energy in these events is 10{sup 21.91} erg, within the “picoflare” range, and many events reach classical “nanoflare” energies. We also estimated the multithermal distribution of temperatures that would result from the heating-rate variability, andmore » found good agreement with observed widths of coronal differential emission measure distributions. The results of the modeling presented in this paper provide compelling evidence that turbulent heating in the solar atmosphere by Alfven waves accelerates the solar wind in open flux tubes.« less
VARIABILITY OF SURFACE FLOWS ON THE SUN AND THE IMPLICATIONS FOR EXOPLANET DETECTION

The published Mount Wilson Doppler-shift measurements of the solar velocity field taken in 1967-1982 are revisited with a more accurate model, which includes two terms representing the meridional flow and three terms corresponding to the convective limb shift. Integration of the recomputed data over the visible hemisphere reveals significant variability of the net radial velocity at characteristic time scales of 0.1-10 years, with a standard deviation of 1.4 m s^(–1). This result is supported by independent published observations. The implications for exoplanet detection include reduced sensitivity of the Doppler method to Earth-like planets in the habitable zone, and an elevated probability of false detections at periods of a few to several years.
Chern-Simons matrix models and unoriented strings

For matrix models with measure on the Lie algebra of SO/Sp, the sub-leading free energy is given by F 1(S) = ±(1/4)∂ F0(S)/∂ S. Motivated by the fact that this relationship does not hold for Chern-Simons theory on S 3 , we calculate the sub-leading free energy in the matrix model for this theory, which is a gaussian matrix model with Haar measure on the group SO/Sp. We derive a quantum loop equation for this matrix model and then find that F 1 is an integral of the leading order resolvent over the spectral curve. We explicitly calculate this integral for quadratic potential and find agreement with previous studies of SO/Sp Chern-Simons theory.
Scalar vortex coronagraph mask design and predicted performance

Vortex coronagraphs are an attractive solution for imaging exoplanets with future space telescopes due to their relatively high throughput, large spectral bandwidth, and low sensitivity to low-order aberrations compared to other coronagraphs with similar inner working angles. Most of the vortex coronagraph mask development for space applications has focused on generating a polychromatic, vectorial, optical vortex using multiple layers of liquid crystal polymers. While this approach has been the most successful thus far, current fabrication processes achieve retardance errors of 0.1-1.0°, which causes a nonnegligible fraction of the starlight to leak through the coronagraph. Circular polarizers are typically used to reject the stellar leakage reducing the throughput by a factor of two. Vector vortex masks also complicate wavefront control because they imprint conjugated phase ramps on the orthogonal circular polarization components, which may need to be split in order to properly sense and suppress the starlight. Scalar vortex masks can potentially circumvent these limitations by applying the same phase shift to all incident light regardless of the polarization state and thus have the potential to significantly improve the performance of vortex coronagraphs. We present scalar vortex coronagraph designs that make use of focal plane masks with multiple layers of dielectrics that (a) produce phase patterns that are relatively friendly to standard manufacturing processes and (b) achieve sufficient broadband starlight suppression, in theory, for imaging Earth-like planets with future space telescopes.
Diophantine properties of IETs and general systems: quantitative proximality and connectivity

Three properties of dynamical systems (recurrence, connectivity and proximality) are quantified by introducing and studying the gauges (measurable functions) corresponding to each of these properties. The properties of the proximality gauge are related to the results in the active field of shrinking targets. The emphasis in the present paper is on the IETs (interval exchange transformations) $( \mathcal {I},T)$ , $\mathcal {I}=[0,1)$ . In particular, we prove that if an IET T is ergodic (relative to the Lebesgue measure λ), then the equality A1 $$ \liminf_{n\to\infty} \, n\, \bigl|T^n(x)-y \bigr|=0 $$ holds for λ×λ-a.a. $(x,y)\in \mathcal {I}^{2}$ . The ergodicity assumption is essential: the result does not extend to all minimal IETs. Also, the factor n in (A1) is optimal (e.g., it cannot be replaced by n ln(ln(lnn))). On the other hand, for Lebesgue almost all 3-IETs $( \mathcal {I},T)$ we prove that for all ϵ>0 A2 $$ \liminf_{n\to\infty} \, n^ \epsilon \bigl |T^n(x)-T^n(y)\bigr| = \infty,\quad\text{for Lebesgue a.a.} \ (x,y)\in \mathcal {I}^2. $$ This should be contrasted with the equality lim inf n→∞ |T n (x)−T n (y)|=0, for a.a. $(x,y)\in \mathcal {I}^{2}$ , which holds since $( \mathcal {I}^{2}, T\times T)$ is ergodic (because generic 3-IETs $( \mathcal {I},T)$ are weakly mixing). We introduce the notion of τ-entropy of an IET which is related to obtaining estimates of type (A2). We also prove that no 3-IET is strongly topologically mixing.
Robust high-fidelity DFT study of the lithium-graphite phase diagram

Lithium intercalation in graphite is an important process in the context of anodes for lithium ion batteries. With increasing demands on lithium ion batteries to operate at lower temperatures and higher currents, it is crucial to understand lithium intercalation in graphite due to issues associated with lithium plating. Lithium intercalation into graphite has been extensively studied theoretically using density functional theory (DFT) calculations, complemented by experimental studies through x-ray diffraction, spectroscopy, optical imaging, and other techniques. In this work, we present a first-principles-based model using DFT calculations, employing the Bayesian error estimation functional van der Waals (BEEF-vdW) as the exchange correlation functional, and Ising model to determine the phase transformations and, subsequently, the thermodynamic intercalation potential diagram. We explore a configurational phase space of about $1\ifmmode\times\else\texttimes\fi{}{10}^{9}$ structures by accurately determining the important interactions for the Ising model. The BEEF-vdW exchange correlation functional employed accurately captures a range of interactions including vdW, covalent, and ionic interactions. We incorporate phonon contributions at finite temperatures and configurational entropy to get high accuracy in free energy and potentials. We utilize the built-in error estimation capabilities of the BEEF-vdW exchange correlation functional and develop a methodological framework for determining the uncertainty associated with DFT calculated phase diagrams and intercalation potentials. The framework also determines the confidence of each predicted stable phase. The confidence value of a phase can help us to identify regions of solid solutions and phase transformations accurately. Given the subtle differences in energy between lithium intercalation into graphite and lithium plating $(l0.1\phantom{\rule{0.16em}{0ex}}\mathrm{eV})$, we believe such an error estimation framework is crucial to know the reliability of DFT predictions.
HAZMAT. I. THE EVOLUTION OF FAR-UV AND NEAR-UV EMISSION FROM EARLY M STARS*

The spectral energy distribution, variability, and evolution of the high-energy radiation from an M dwarf planet host is crucial in understanding the planet's atmospheric evolution and habitability and in interpreting the planet's spectrum. The star's extreme-UV (EUV), far-UV (FUV), and near-UV (NUV) emission can chemically modify, ionize, and erode the atmosphere over time. This makes determining the lifetime exposure of such planets to stellar UV radiation critical for both the evolution of a planet's atmosphere and our potential to characterize it. Using the early M star members of nearby young moving groups, which sample critical ages in planet formation and evolution, we measure the evolution of the GALEX NUV and FUV flux as a function of age. The median UV flux remains at a 'saturated' level for a few hundred million years, analogous to that observed for X-ray emission. By the age of the Hyades Cluster (650 Myr), we measure a drop in UV flux by a factor of 2-3 followed by a steep drop from old (several Gyrs) field stars. This decline in activity beyond 300 Myr follows roughly t {sup –1}. Despite this clear evolution, there remains a wide range, of 1-2 orders of magnitude, in observed emission more » levels at every age. These UV data supply the much-needed constraints to M dwarf upper-atmosphere models, which will provide empirically motivated EUV predictions and more accurate age-dependent UV spectra as inputs to planetary photochemical models. « less
A Fast Chi-Squared Technique for Period Search of Irregularly Sampled Data

A new, computationally and statistically efficient algorithm, the Fast χ2 algorithm (Fχ2), can find a periodic signal with harmonic content in irregularly sampled data with nonuniform errors. The algorithm calculates the minimized χ2 as a function of frequency at the desired number of harmonics, using fast Fourier transforms to provide O(Nlog N) performance. The code for a reference implementation is provided.
KINETIC TOMOGRAPHY. I. A METHOD FOR MAPPING THE MILKY WAY’S INTERSTELLAR MEDIUM IN FOUR DIMENSIONS

We have developed a method for deriving the distribution of the Milky Way's interstellar medium as a function of longitude, latitude, distance, and line-of-sight velocity. This method takes as input maps of reddening as a function of longitude, latitude, distance, and maps of line emission as a function of longitude, latitude, and line-of-sight velocity. We have applied this method to data sets covering much of the Galactic plane. The output of this method correctly reproduces the line-of-sight velocities of high-mass star-forming regions with known distances from Reid et al. and qualitatively agrees with results from the Milky Way kinematics literature. These maps will be useful for measuring flows of gas around the Milky Way's spiral arms and into and out of giant molecular clouds.
Berry Fermi liquid theory

Abstract We develop an extension of the Landau Fermi liquid theory to systems of interacting fermions with non-trivial Berry curvature. We propose a kinetic equation and a constitutive relation for the electromagnetic current that together encode the linear response of such systems to external electromagnetic perturbations, to leading and next-to-leading orders in the expansion over the frequency and wave number of the perturbations. We analyze the Feynman diagrams in a large class of interacting quantum field theories and show that, after summing up all orders in perturbation theory, the current–current correlator exactly matches with the result obtained from the kinetic theory.
Nonparaxial Near-Nondiffracting Accelerating Optical Beams

We show that new families of accelerating and almost nondiffracting beams (solutions) for Maxwell’s equations can be constructed. These are complex geometrical optics (CGO) solutions to Maxwell’s equations with nonlinear limiting Carleman weights. They have the form of wave packets that propagate along circular trajectories while almost preserving a transverse intensity profile. We also show similar waves constructed using the approach combining CGO solutions and the Kelvin transform.
AN ALTERNATIVE STRING LANDSCAPE COSMOLOGY: ELIMINATING BIZARRENESS

In what has become a standard eternal inflation picture of the string landscape there are many problematic consequences and a difficulty defining probabilities for the occurrence of each type of universe. One feature in particular that might be philosophically disconcerting is the infinite cloning of each individual and each civilization in infinite numbers of separated regions of the multiverse. Even if this is not ruled out due to causal separation one should ask whether the infinite cloning is a universal prediction of string landscape models or whether there are scenarios in which it is avoided. If a viable alternative cosmology can be constructed one might search for predictions that might allow one to discriminate experimentally between the models. We present one such scenario although, in doing so, we are forced to give up several popular presuppositions including the absence of a preferred frame and the homogeneity of matter in the universe. The model also has several ancillary advantages. We also consider the future lifetime of the current universe before becoming a light trapping region.
A generalization of Mathieu subspaces to modules of associative algebras

We first propose a generalization of the notion of Mathieu subspaces of associative algebras \( \mathcal{A} \), which was introduced recently in [Zhao W., Generalizations of the image conjecture and the Mathieu conjecture, J. Pure Appl. Algebra, 2010, 214(7), 1200–1216] and [Zhao W., Mathieu subspaces of associative algebras], to \( \mathcal{A} \)-modules \( \mathcal{M} \). The newly introduced notion in a certain sense also generalizes the notion of submodules. Related with this new notion, we also introduce the sets σ(N) and τ(N) of stable elements and quasi-stable elements, respectively, for all R-subspaces N of \( \mathcal{A} \)-modules \( \mathcal{M} \), where R is the base ring of \( \mathcal{A} \). We then prove some general properties of the sets σ(N) and τ(N). Furthermore, examples from certain modules of the quasi-stable algebras [Zhao W., Mathieu subspaces of associative algebras], matrix algebras over fields and polynomial algebras are also studied.
X-ray temperatures, luminosities, and masses from XMM-Newton follow-up of the first shear-selected galaxy cluster sample

Author(s): Deshpande, AJ; Hughes, JP; Wittman, D | Abstract: We continue the study of the first sample of shear-selected clusters from the initial 8.6 square degrees of the Deep Lens Survey (DLS); a sample with well-defined selection criteria corresponding to the highest ranked shear peaks in the survey area. We aim to characterize the weak lensing selection by examining the sample's X-ray properties. There are multiple X-ray clusters associated with nearly all the shear peaks: 14 X-ray clusters corresponding to seven DLS shear peaks. An additional three X-ray clusters cannot be definitively associated with shear peaks, mainly due to large positional offsets between the X-ray centroid and the shear peak. Here we report on the XMM-Newton properties of the 17 X-ray clusters. The X-ray clusters display a wide range of luminosities and temperatures; the L X-T X relation we determine for the shear-associated X-ray clusters is consistent with X-ray cluster samples selected without regard to dynamical state, while it is inconsistent with self-similarity. For a subset of the sample, we measure X-ray masses using temperature as a proxy, and compare to weak lensing masses determined by the DLS team. The resulting mass comparison is consistent with equality. The X-ray and weak lensing masses show considerable intrinsic scatter (∼48%), which is consistent with X-ray selected samples when their X-ray and weak lensing masses are independently determined.
Controlling the shape of membrane protein polyhedra

Membrane proteins and lipids can self-assemble into membrane protein polyhedral nanoparticles (MPPNs). MPPNs have a closed spherical surface and a polyhedral protein arrangement, and may offer a new route for structure determination of membrane proteins and targeted drug delivery. We develop here a general analytic model of how MPPN self-assembly depends on bilayer-protein interactions and lipid bilayer mechanical properties. We find that the bilayer-protein hydrophobic thickness mismatch is a key molecular control parameter for MPPN shape that can be used to bias MPPN self-assembly towards highly symmetric and uniform MPPN shapes. Our results suggest strategies for optimizing MPPN shape for structural studies of membrane proteins and targeted drug delivery.
Galactic rotation curves in conformal gravity

We review some recent work by Mannheim and O'Brien on the systematics of galactic rotation curves in the conformal gravity theory. In this work the conformal theory was applied to a comprehensive, high quality sample of spiral galaxies whose rotation curves extend well beyond the galactic optical disks. On galactic scales the conformal gravitational theory departs from the standard Newtonian theory in two distinct ways. One is a local way in which local matter sources within galaxies generate not just Newtonian potentials but linear potentials as well. The other is a global way in which two universal global potentials, one linear the other quadratic, are generated by the rest of the matter in the universe. The study involves a broad set of 138 spiral galaxies of differing luminosities and sizes, and is augmented here through the inclusion of an additional three tidal dwarf galaxies. With its linear and quadratic potentials the conformal theory can account for the systematics of an entire 141 galaxy sample without any need for galactic dark matter, doing so with only one free parameter per galaxy, namely the visible galactic mass to light ratio.
Learning Guidance Rewards with Trajectory-space Smoothing

Long-term temporal credit assignment is an important challenge in deep reinforcement learning (RL). It refers to the ability of the agent to attribute actions to consequences that may occur after a long time interval. Existing policy-gradient and Q-learning algorithms typically rely on dense environmental rewards that provide rich short-term supervision and help with credit assignment. However, they struggle to solve tasks with delays between an action and the corresponding rewarding feedback. To make credit assignment easier, recent works have proposed algorithms to learn dense "guidance" rewards that could be used in place of the sparse or delayed environmental rewards. This paper is in the same vein -- starting with a surrogate RL objective that involves smoothing in the trajectory-space, we arrive at a new algorithm for learning guidance rewards. We show that the guidance rewards have an intuitive interpretation, and can be obtained without training any additional neural networks. Due to the ease of integration, we use the guidance rewards in a few popular algorithms (Q-learning, Actor-Critic, Distributional-RL) and present results in single-agent and multi-agent tasks that elucidate the benefit of our approach when the environmental rewards are sparse or delayed.
End-To-End Alzheimer's Disease Diagnosis and Biomarker Identification.

As shown in computer vision, the power of deep learning lies in automatically learning relevant and powerful features for any perdition task, which is made possible through end-to-end architectures. However, deep learning approaches applied for classifying medical images do not adhere to this architecture as they rely on several pre- and post-processing steps. This shortcoming can be explained by the relatively small number of available labeled subjects, the high dimensionality of neuroimaging data, and difficulties in interpreting the results of deep learning methods. In this paper, we propose a simple 3D Convolutional Neural Networks and exploit its model parameters to tailor the end-to-end architecture for the diagnosis of Alzheimer’s disease (AD). Our model can diagnose AD with an accuracy of 94.1% on the popular ADNI dataset using only MRI data, which outperforms the previous state-of-the-art. Based on the learned model, we identify the disease biomarkers, the results of which were in accordance with the literature. We further transfer the learned model to diagnose mild cognitive impairment (MCI), the prodromal stage of AD, which yield better results compared to other methods.
Resonant Bound-Free Contributions to Thomson Scattering of X-rays by Warm Dense Matter

Abstract Recent calculations [Nilsen et al. arXiv:1212.5972 ] predict that contributions to the scattered photon spectrum from 3s and 3p bound states in chromium (Z = 24) at metallic density and T = 12 eV resonate below the respective bound-state thresholds. These resonances are shown to be closely related to continuum lowering, where 3d bound states in the free atom dissolve into a resonant l = 2 partial wave in the continuum. The resulting d-state resonance dominates contributions to the bound-free dynamic structure function, leading to the predicted resonances in the scattered X-ray spectrum. Similar resonant features are shown to occur in all elements in the periodic table between Ca and Mn (20 ≤ Z ≤ 25).
More Exotic Field Theories in 3+1 Dimensions

We continue the exploration of nonstandard continuum field theories related to fractons in 3+1 dimensions. Our theories exhibit exotic global and gauge symmetries, defects with restricted mobility, and interesting dualities. Depending on the model, the defects are the probe limits of either fractonic particles, strings, or strips. One of our models is the continuum limit of the plaquette Ising lattice model, which features an important role in the construction of the X-cube model.
Analogue to Digital and Digital to Analogue Converters (ADCs and DACs): A Review Update

This is a review paper updated from that presented for CAS 2004. Essentially, since then, commercial components have continued to extend their performance boundaries but the basic building blocks and the techniques for choosing the best device and implementing it in a design have not changed. Analogue to digital and digital to analogue converters are crucial components in the continued drive to replace analogue circuitry with more controllable and less costly digital processing. This paper discusses the technologies available to perform in the likely measurement and control applications that arise within accelerators. It covers much of the terminology and ‘specmanship’ together with an application-oriented analysis of the realisable performance of the various types. Finally, some hints and warnings on system integration problems are given.
Enzymatic AND Logic Gate with Sigmoid Response Induced by Photochemically Controlled Oxidation of the Output

We report a study of a system which involves an enzymatic cascade realizing an AND logic gate, with an added photochemical processing of the output, allowing the gate’s response to be made sigmoid in both inputs. New functional forms are developed for quantifying the kinetics of such systems, specifically designed to model their response in terms of signal and information processing. These theoretical expressions are tested for the studied system, which also allows us to consider aspects of biochemical information processing such as noise transmission properties and control of timing of the chemical and physical steps.
Scl in graphs of groups

Let G be a group acting on a tree with cyclic edge and vertex stabilizers. Then stable commutator length (scl) is rational in G. Furthermore, scl varies predictably and converges to rational limits in so-called “surgery” families. This is a homological analog of the phenomenon of geometric convergence in hyperbolic Dehn surgery.
Low energy probes of physics beyond the standard model

Low-energy tests of fundamental symmetries and studies of neutrino properties provide a powerful window on physics beyond the Standard Model (BSM). In this article, we provide a basic theoretical framework for a subsequent set of articles that review the progress and opportunities in various aspects of the low-energy program. We illustrate the physics reach of different low-energy probes in terms of an effective BSM mass scale and illustrate how this reach matches and, in some cases, even exceeds that accessible at the high energy frontier.
Observations of dark and luminous matter: the radial distribution of satellite galaxies around massive red galaxies

We study the projected radial distribution of satellite galaxies around more than 28,000 luminous red galaxies (LRGs) at 0.28 25 kpc whereas baryons account for more than 50% of the mass at smaller radii. We calculate the total dark-to-baryonic mass ratio and show that it is consistent with measurements from weak lensing for environments dominated by massive early-type galaxies. Finally, we divide the satellite galaxies in our sample into three luminosity bins and show that the satellite light profiles of all brightness levels are consistent with each other outside of roughly 25 kpc. At smaller radii we find evidence for a mild mass segregation with an increasing fraction of bright satellites close to the central LRG.
Volumetric Medical Image Segmentation: A 3D Deep Coarse-to-Fine Framework and Its Adversarial Examples

Although deep neural networks have been a dominant method for many 2D vision tasks, it is still challenging to apply them to 3D tasks, such as medical image segmentation, due to the limited amount of annotated 3D data and limited computational resources. In this chapter, by rethinking the strategy to apply 3D Convolutional Neural Networks to segment medical images, we propose a novel 3D-based coarse-to-fine framework to efficiently tackle these challenges. The proposed 3D-based framework outperforms their 2D counterparts by a large margin since it can leverage the rich spatial information along all three axes. We further analyze the threat of adversarial attacks on the proposed framework and show how to defend against the attack. We conduct experiments on three datasets, the NIH pancreas dataset, the JHMI pancreas dataset and the JHMI pathological cyst dataset, where the first two and the last one contain healthy and pathological pancreases, respectively, and achieve the current state of the art in terms of Dice-Sorensen Coefficient (DSC) on all of them. Especially, on the NIH pancreas dataset, we outperform the previous best by an average of over \(2\%\), and the worst case is improved by \(7\%\) to reach almost \(70\%\), which indicates the reliability of our framework in clinical applications.
THE COLORS OF EXTREME OUTER SOLAR SYSTEM OBJECTS

Extreme outer solar system objects have possible origins beyond the Kuiper Belt edge, high inclinations, very large semimajor axes, or large perihelion distances. Thirty-three such objects were observed in this work to determine their optical colors. All three objects that have been dynamically linked to the inner Oort Cloud by various authors ((90377) Sedna, 2006 SQ372, and (87269) 2000 OO67) were found to have ultra-red surface material (spectral gradient, S ~ 25). Ultra-red material is generally associated with rich organics and the low inclination "cold" classical Kuiper Belt objects (KBOs). The observations detailed here show that very red material may be a more general feature for objects kept far from the Sun. The recently discovered retrograde outer solar system objects (2008 KV42 and 2008 YB3) and the high inclination object (127546) 2002 XU93 show only moderately red surfaces (S ~ 9) very similar to known comets, suspected dead comets, Jupiter and Neptune Trojans, irregular satellites, D-type asteroids, and damocloids. The extended or detached disk objects, which have large perihelion distances and are thus considered to be detached from the influence of the giant planets but yet have large eccentricities, are found to have mostly moderately red colors (10 S 18). The colors of the detached disk objects, including the dynamically unusual 2004 XR190 and (148209) 2000 CR105, are similar to the scattered disk and Plutino populations. Thus the detached disk, scattered disk, Plutino, and high inclination "hot" classical objects likely have a similar mix of objects from the same source regions. Outer classical KBOs, including (48639) 1995 TL8, were found to have very red surfaces (18 S 30). The low inclination "cold" classical KBOs, outer classical KBOs and possibly the inner Oort Cloud appear to be dominated by ultra-red objects (S 25) and thus do not likely have a similar mix of objects as the other outer solar system reservoirs such as the scattered disk, detached disk, and Trojan populations. A possible trend was found for the detached disk and outer classical Kuiper Belt in that objects with smaller eccentricities have redder surfaces irrespective of inclinations or perihelion distances. There is also a clear trend that objects more distant appear redder.
CIRCUMSTELLAR SHELLS IN ABSORPTION IN TYPE Ia SUPERNOVAE

Progenitors of Type Ia supernovae (SNe) have been predicted to modify their ambient circumstellar (CSM) and interstellar environments through the action of their powerful winds. While there is X-ray and optical evidence for circumstellar interaction in several remnants of Type Ia SNe, widespread evidence for such interaction in Type Ia SNe themselves has been lacking. We consider prospects for the detection of CSM shells that have been predicted to be common around Type Ia SNe. Such shells are most easily detected in Na I absorption lines. Variable (declining) absorption is expected to occur soon after the explosion, primarily during the SN rise time, for shells located within ~1-10 pc of a SN. The distance of the shell from the SN can be determined by measuring the timescale for line variability.
Fermionization, Convergent Perturbation Theory, and Correlations in the Yang–Mills Quantum Field Theory in Four Dimensions

We show that the Yang–Mills quantum field theory with momentum and spacetime cutoffs in four Euclidean dimensions is equivalent, term by term in an appropriately resummed perturbation theory, to a Fermionic theory with nonlocal interaction terms. When a further momentum cutoff is imposed, this Fermionic theory has a convergent perturbation expansion. To zeroth order in this perturbation expansion, the correlation function E(x,y) of generic components of pairs of connections is given by an explicit, finite-dimensional integral formula, which we conjecture will behave as $$ E(x,y) \sim |x - y|^{-2 - 2 d_G}, $$ for \({|x-y|\gg 0}\), where dG is a positive integer depending on the gauge group G. In the case where G = SU(N), we conjecture that $$ d_G = {\rm dim}\;SU(N) - {\rm dim}\;S(U(N-1) \times U(1)), $$ so that the rate of decay of correlations increases as N → ∞.
Diffraction imaging for in situ characterization of double-crystal X-ray monochromators

Imaging of the Bragg-reflected X-ray beam is proposed and validated as an in situ method for characterization of the performance of double-crystal monochromators under the heat load of intense synchrotron radiation. A sequence of images is collected at different angular positions on the reflectivity curve of the second crystal and analyzed. The method provides rapid evaluation of the wavefront of the exit beam, which relates to local misorientation of the crystal planes along the beam footprint on the thermally distorted first crystal. The measured misorientation can be directly compared with the results of finite element analysis. The imaging method offers an additional insight into the local intrinsic crystal quality over the footprint of the incident X-ray beam.
Reduced-order modeling using Dynamic Mode Decomposition and Least Angle Regression

Dynamic Mode Decomposition (DMD) yields a linear, approximate model of a system's dynamics that is built from data. We seek to reduce the order of this model by identifying a reduced set of modes that best fit the output. We adopt a model selection algorithm from statistics and machine learning known as Least Angle Regression (LARS). We modify LARS to be complex-valued and utilize LARS to select DMD modes. We refer to the resulting algorithm as Least Angle Regression for Dynamic Mode Decomposition (LARS4DMD). Sparsity-Promoting Dynamic Mode Decomposition (DMDSP), a popular mode-selection algorithm, serves as a benchmark for comparison. Numerical results from a Poiseuille flow test problem show that LARS4DMD yields reduced-order models that have comparable performance to DMDSP. LARS4DMD has the added benefit that the regularization weighting parameter required for DMDSP is not needed.