cssi/SciSciGPT-SciSciNet huggingface dataset:
Magnetically Induced Current Piston for Generating Extreme-ultraviolet Fronts in the Solar Corona

Single-pulse, globally propagating coronal fronts, called Extreme-ultraviolet (EUV) waves, were first observed in 1995 by the Extreme-ultraviolet Imaging Telescope and every observed EUV wave since has been associated with a coronal mass ejection (CME). The physical mechanism underlying these waves has been debated for two decades with wave or pseudo-wave theories being advocated. We propose a hybrid model where EUV waves are compressional fronts driven by a reverse electric current layer induced by the time-dependent CME core current. The reverse current layer flows in a direction opposite to the CME core current and is an eddy current layer necessary to maintain magnetic flux conservation above the layer. Repelled by the core current, the reverse current layer accelerates upward so it acts as a piston that drives a compressional perturbation in the coronal regions above. Given a sufficiently fast piston speed, the compressional perturbation becomes a shock that separates from the piston when the piston slows down. Since the model relates the motion of the EUV front to CME properties, the model provides a bound for the core current of an erupting CME. The model is supported and motivated by detailed results from both laboratory experiments and ideal 3D magnetohydrodynamic simulations. Overlaps and differences with other models and spacecraft observations are discussed.
Numerical Modeling of Frictional Contact Between a Blunt Tool and Quasi-Brittle Rock

Frictional contact is an important component of rock cutting with a blunt cutter. There has been a gap in knowledge of frictional contact between experimental tests conducted on quasi-brittle rocks and previous numerical and analytical analyses on elastoplastic rocks. The average contact stress between a sliding wear flat and a rock is generally overestimated in previous studies without considering material length scales. This study analyzes the contact stress using an elasto-plastic-damage model that accounts for the material length scales of quasi-brittle materials. The constitutive model is developed for quasi-brittle materials by incorporating fracture energy, and it is implemented in the commercial finite element software ABAQUS as a user-defined material model. The implemented constitutive model is verified under uniaxial tension and compression. The average contact stress in frictional contact is mainly governed by a dimensionless elastoplastic parameter $$ \eta $$ for an elastoplastic rock, while it is predominantly governed by two dimensionless parameters: an elastoplastic parameter $$ \eta $$ and a brittleness number $$ \xi $$ for a quasi-brittle rock. The dimensionless elastoplastic parameter $$ \eta $$ contrasts the magnitude of a characteristic elastic contact stress to the yield strength of a material, and the brittleness number $$ \xi $$ is the ratio of a geometrical length scale to a material length scale. The tool–rock interface can be approximately divided into an elastic zone and a damage process zone. The contact stress generally increases in the elastic zone and then decreases in the damage process zone towards the tip of the slider. The average contact stress generally increases with the dimensionless elastoplastic parameter $$ \eta $$ and then levels off at a limit value, and it generally decreases with the brittleness number $$ \xi $$ . This study reduces the gap in previous studies to some extent by introducing the brittleness number $$ \xi $$ in frictional contact. The current numerical results of the average contact stress are generally consistent with typical experimental results conducted on quasi-brittle rocks, despite limitations in the finite element modeling.
Node aware sparse matrix–vector multiplication

Abstract The sparse matrix–vector multiply (SpMV) operation is a key computational kernel in many simulations and linear solvers. The large communication requirements associated with a reference implementation of a parallel SpMV result in poor parallel scalability. The cost of communication depends on the physical locations of the send and receive processes: messages injected into the network are more costly than messages sent between processes on the same node. In this paper, a node aware parallel SpMV (NAPSpMV) is introduced to exploit knowledge of the system topology, specifically the node-processor layout, to reduce costs associated with communication. The values of the input vector are redistributed to minimize both the number and the size of messages that are injected into the network during a SpMV, leading to a reduction in communication costs. A variety of computational experiments that highlight the efficiency of this approach are presented.
Novel open technique for repair of endograft migration

Abstract Widespread adoption of endovascular aneurysm repair has led to increased incidence of late complications, such as endograft migration. Treatment options have to be tailored to the patient's health, quality of proximal aorta, and extent of migration. Complete or partial endograft removal is associated with significant morbidity and mortality. We describe a case in which open repair with endograft preservation was employed, with the additional benefit of a sutured proximal anastomosis.
Inhibition of EZH2 Ameliorates Lupus‐Like Disease in MRL/lpr Mice

Objective We previously identified a role for EZH2, a transcriptional regulator in inducing proinflammatory epigenetic changes in lupus CD4+ T cells. This study was undertaken to investigate whether inhibiting EZH2 ameliorates lupus-like disease in MRL/lpr mice. Methods EZH2 expression levels in multiple cell types in lupus patients were evaluated using flow cytometry and messenger RNA expression data. Inhibition of EZH2 in MRL/lpr mice was achieved by intraperitoneal 3'-deazaneplanocin (DZNep) administration using a preventative and a therapeutic treatment model. Effects of DZNep on animal survival, anti-double-stranded DNA (anti-dsDNA) antibody production, proteinuria, renal histopathology, cytokine production, and T and B cell numbers and percentages were assessed. Results EZH2 expression levels were increased in whole blood, neutrophils, monocytes, B cells, and CD4+ T cells in lupus patients. In MRL/lpr mice, inhibition of EZH2 by DZNep was confirmed by significant reduction of EZH2 and H3K27me3 in splenocytes. Inhibiting EZH2 with DZNep treatment before or after disease onset improved survival and significantly reduced anti-dsDNA antibody production. DZNep-treated mice displayed a significant reduction in renal involvement, splenomegaly, and lymphadenopathy. Lymphoproliferation and numbers of double-negative T cells were significantly reduced in DZNep-treated mice. Concentrations of circulating cytokines and chemokines, including tumor necrosis factor, interferon-γ, CCL2, RANTES/CCL5, interleukin-10 (IL-10), keratinocyte-derived chemokine/CXCL1, IL-12, IL-12p40, and CCL4/macrophage inflammatory protein 1β, were decreased in DZNep-treated mice. Conclusion EZH2 is up-regulated in multiple cell types in lupus patients. Therapeutic inhibition of EZH2 abrogates lupus-like disease in MRL/lpr mice, suggesting that EZH2 inhibitors may be repurposed as a novel therapeutic option for lupus patients.
SYNTHESIS OF THE D-3 SERIES OF PHOSPHATIDYLINOSITOL PHOSPHATES

The 3-mono-, 3,4-bis-, and 3,4,5-trisphosphates of l-α-phosphatidyl-d-myo-inositol have been synthesized in their optically active forms from the two enantiomers of 1,2:5,6-di-O-cyclohexylidene-myo...
Synthesis, structure, reactions, and photoelectron spectra of new mixed sulfur‐, selenium‐ or tellurium and silicon‐ or tin‐containing heterocycles

More than 40 new 4- to 12-membered ring heterocycles containing various combinations of Group 14 elements (Si and Sn) and Group 16 elements (S, Se, and Te) have been synthesized and fully characterized. Synthesis of these small-ring as well as medium-ring (mesocyclic) heterocycles from α, ω-dihalides was facilitated by the presence of gem-dialkylsilyl and gem-dialkylstannyl groups in the precursors. Solid-state conformations of the new ring systems have been determined by X-ray crystallography. Oxidation of mixed S(Se, Te)/Si eight-membered ring mesocycles as well as 1,5-dithia-, 1,5-diselena-, and 1,5-ditelluracyclooctane with NOPF6 gave dications, which can be characterized by NMR. On treatment with nucleophiles, mesocyclic dications or the corresponding radical cations underwent ring contraction to give five- or six-membered ring heterocycles. The ionization energies of the above conformationally constrained β-disilanyl sulfides and selenides were determined by photoelectron spectroscopy. These ionization energies reflect substantial (0.53--0.75 eV) orbital destabilizations. The basis for these destabilizations was investigated by theoretical calculations, which reveal geometry-dependent interaction between sulfur or selenium lone pair orbitals and σ-orbitals, especially Si–Si σ-orbitals. These results suggest facile redox chemistry for these compounds and significantly extend the concept of σ-stabilization of electron-deficient centers. © 2007 Wiley Periodicals, Inc. 18:509–515, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20333
Total Syntheses of FR901464

Three total syntheses of potent anticancer natural product FR901464 are described. The first total synthesis by the Jacobsen group used transition metal-catalyzed reactions to prepare their chiral fragments. Subsequently, the Kitahara group described their synthesis using the chiral pool to construct their building blocks. Finally, the Koide group published the most recent synthesis of FR901464 using both asymmetric reactions and the chiral pool for their chiral fragment syntheses. It is envisioned that these total syntheses will assist biological studies of FR901464 and its unique mode of action.
Highly efficient biphasic ozonolysis of alkenes using a high-throughput film-shear flow reactor

Abstract A new method for ozonolysis of alkenes using a continuous flow film-shear reactor was developed. The reactor uses a shearing microfluidic mixing chamber to provide biphasic mixing of an organic phase and aqueous phase with ozone gas. The H2O acts as an in situ reducing agent for the carbonyl oxide intermediate, providing ketones and aldehydes directly from the reaction mixture. Flow rates of up to 1.0 mmol/min (alkene) with an ozone reaction efficiency of >70% were achieved. Aryl conjugated olefins reacted to form carbonyl species in good yields on a multi-gram scale; however, alkyl olefins reacted with ozone to predominantly form secondary ozonides. The discrepancy in product distributions between alkyl and aryl olefins likely originates from the electronic stability of the carbonyl oxide intermediate, which is longer lived for aryl derivatives due to conjugation.
5-Bromo-DL-tryptophan and Protected Intermediates for Peptide Synthesis

Abstract A convenient synthesis of 5-bromotryptophan and protected intermediates for peptide synthesis is reported. Only three steps are required to convert ethyl pyruvate into 5-bromo-tryptophan ethyl ester.
Cell type-dependent effects of ellagic acid on cellular metabolism

Ellagic acid is a botanical polyphenol which has been shown to have numerous effects on cellular function. Ellagic acid can induce apoptosis and inhibit the proliferation of various cancer cell types in vitro and in vivo. As such, ellagic acid has attracted significant interest as a potential chemotherapeutic compound. One mechanism by which ellagic acid has been proposed to affect cellular physiology is by regulating metabolic pathways. Here we show the dose-dependent effects of ellagic acid on cellular energy production and downstream induction of the apoptotic program in HEK293, HeLa, MCF7, and HepG2 cells. At physiologically relevant doses, ellagic acid has pleiotropic and cell-type specific effects on mitochondrial function. At high doses ellagic acid can also influence glycolytic pathways and induce cell death. Our results demonstrate that ellagic acid can influence mitochondrial function at therapeutically relevant concentrations. The observed effects of ellagic acid on cellular respiration are complex and cell type-specific, which may limit the chemotherapeutic utility of this compound.
Integration of cell cycle signals by multi-PAS domain kinases

Spatial control of intracellular signaling relies on signaling proteins sensing their subcellular environment. In many cases, a large number of upstream signals are funneled to a master regulator of cellular behavior, but it remains unclear how individual proteins can rapidly integrate a complex array of signals within the appropriate spatial niche within the cell. As a model for how subcellular spatial information can control signaling activity, we have reconstituted the cell pole-specific control of the master regulator kinase/phosphatase CckA from the asymmetrically dividing bacterium Caulobacter crescentus CckA is active as a kinase only when it accumulates within a microdomain at the new cell pole, where it colocalizes with the pseudokinase DivL. Both proteins contain multiple PAS domains, a multifunctional class of sensory domains present across the kingdoms of life. Here, we show that CckA uses its PAS domains to integrate information from DivL and its own oligomerization state to control the balance of its kinase and phosphatase activities. We reconstituted the DivL-CckA complex on liposomes in vitro and found that DivL directly controls the CckA kinase/phosphatase switch, and that stimulation of either CckA catalytic activity depends on the second of its two PAS domains. We further show that CckA oligomerizes through a multidomain interaction that is critical for stimulation of kinase activity by DivL, while DivL stimulation of CckA phosphatase activity is independent of CckA homooligomerization. Our results broadly demonstrate how signaling factors can leverage information from their subcellular niche to drive spatiotemporal control of cell signaling.
In vitro reconstitution of T cell receptor-mediated segregation of the CD45 phosphatase

T cell signaling initiates upon the binding of peptide-loaded MHC (pMHC) on an antigen-presenting cell to the T cell receptor (TCR) on a T cell. TCR phosphorylation in response to pMHC binding is accompanied by segregation of the transmembrane phosphatase CD45 away from TCR-pMHC complexes. The kinetic segregation hypothesis proposes that CD45 exclusion shifts the local kinase-phosphatase balance to favor TCR phosphorylation. Spatial partitioning may arise from the size difference between the large CD45 extracellular domain and the smaller TCR-pMHC complex, although parsing potential contributions of extracellular protein size, actin activity, and lipid domains is difficult in living cells. Here, we reconstitute segregation of CD45 from bound receptor-ligand pairs using purified proteins on model membranes. Using a model receptor-ligand pair (FRB-FKBP), we first test physical and computational predictions for protein organization at membrane interfaces. We then show that the TCR-pMHC interaction causes partial exclusion of CD45. Comparing two developmentally regulated isoforms of CD45, the larger RABC variant is excluded more rapidly and efficiently (∼50%) than the smaller R0 isoform (∼20%), suggesting that CD45 isotypes could regulate signaling thresholds in different T cell subtypes. Similar to the sensitivity of T cell signaling, TCR-pMHC interactions with Kds of ≤15 µM were needed to exclude CD45. We further show that the coreceptor PD-1 with its ligand PD-L1, immunotherapy targets that inhibit T cell signaling, also exclude CD45. These results demonstrate that the binding energies of physiological receptor-ligand pairs on the T cell are sufficient to create spatial organization at membrane-membrane interfaces.
Synthesis and Conversions of Substituted o-[(Trimethylsilyl)methyl]benzyl-p-Tolyl Sulfones to o-Quinodimethanes and Products Thereof.

Use of o-[(trimethylsilyl)methyl]benzyl p-tolyl sulfone (3) for synthesis and cycloaddition of substituted o-quinodimethanes has been investigated. Sulfone 3 is prepared from 2-methylbenzyl alcohol (4) by reactions with n-BuLi and chlorotrimethylsilane to form o-[(trimethylsilyl)methyl]benzyl alcohol (7) which phosphorus tribromide converts to o-[(trimethylsilyl)methyl]benzyl bromide (8). Displacement of 8 with sodium p-toluenesulfinate yields 3. Sulfone 3 is alkylated at its α-sulfonyl position upon deprotonation with n-BuLi followed by methyl iodide, ethyl, butyl, allyl, and benzyl bromides, and 5-bromo-1-pentene, respectively. Acylations occur using acid chlorides. Dialkylation occurs upon further reaction with n-BuLi and an alkyl halide. 1,4-Eliminations of α,α-dialkyl sulfones 11 with tetrabutylammonium fluoride (TBAF) give α,α-dialkyl-o-quinodimethanes (29); 3 is therefore a synthon for the o-quinodimethane-α,α-dianion (34). o-Quinodimethanes 29 undergo (1) cycloaddition with acrylonitrile, acrylate...
Highly stereoselective syntheses of five- and seven-membered ring heterocycles from ylides generated by catalytic reactions of styryldiazoacetates with aldehydes and imines.

Styryldiazoacetates are effective reactants for ylide formation that results in the formation of dihydropyrroles and dihydroazepines with high stereocontrol and in high yields.
Ion-Tagged Phosphines as Ligands for Suzuki Coupling of Aryl Halides in a Phosphonium Ionic Liquid

Gramine-based N-substituted phosphines were synthesized and utilized as ligands in Suzuki–Miyaura coupling of aryl bromides and chlorides in the room temperature ionic liquid trihexyltetradecylphosphonium bis(trifluoromethanesulfonyl)imide. Increased yields were achieved with ion-tagged ligands compared to ligands bearing pendant amines, likely due to higher solubility of the former. Cyclohexyl groups on the phosphine moiety generally resulted in higher yields than tert-butyl groups. In addition, a biphasic ionic liquid/water system outperformed catalysis in neat ionic liquid and provided higher yields at lower temperatures.
Fast Na-Ion Conduction in a Chalcogenide Glass–Ceramic in the Ternary System Na2Se–Ga2Se3–GeSe2

All solid-state rechargeable sodium-ion batteries are of key importance for future energy storage applications and novel electrolytes with improved performance are continuously being sought after for such batteries. Here we report large sodium-ion conductivity (>10–5 S/cm) at ambient temperature in a layered chalcogenide compound of composition Na2(Ga0.1Ge0.9)2Se4.95, synthesized as a glass–ceramic composite in the ternary system Na2Se–Ga2Se3–GeSe2. Alkali-ion-containing crystalline chalcogenides are typically hygroscopic and consequently unstable in an ambient environment. However, in the present study the crystal phase is possibly stabilized against moisture via encapsulation in an inert glass matrix and forms a three dimensionally continuous percolation network for fast sodium-ion conduction. This result demonstrates that such layered chalcogenide compounds with planar pathways for alkali-ion diffusion can serve as viable alternatives to the conventional solid electrolytes.
Genomics of natural populations: Evolutionary forces that establish and maintain gene arrangements in Drosophila pseudoobscura.

The evolution of complex traits in heterogeneous environments may shape the order of genes within chromosomes. Drosophila pseudoobscura has a rich gene arrangement polymorphism that allows one to test evolutionary genetic hypotheses about how chromosomal inversions are established in populations. D. pseudoobscura has >30 gene arrangements on a single chromosome that were generated through a series of overlapping inversion mutations with >10 inversions with appreciable frequencies and wide geographic distributions. This study analyses the genomic sequences of 54 strains of Drosophila pseudoobscura that carry one of six different chromosomal arrangements to test whether (i) genetic drift, (ii) hitchhiking with an adaptive allele, (iii) direct effects of inversions to create gene disruptions caused by breakpoints, or (iv) indirect effects of inversions in limiting the formation of recombinant gametes are responsible for the establishment of new gene arrangements. We found that the inversion events do not disrupt the structure of protein coding genes at the breakpoints. Population genetic analyses of 2,669 protein coding genes identified 277 outlier loci harbouring elevated frequencies of arrangement-specific derived alleles. Significant linkage disequilibrium occurs among distant loci interspersed between regions with low levels of association indicating that distant allelic combinations are held together despite shared polymorphism among arrangements. Outlier genes showing evidence of genetic differentiation between arrangements are enriched for sensory perception and detoxification genes. The data presented here support the indirect effect of inversion hypothesis where chromosomal inversions are favoured because they maintain linked associations among multilocus allelic combinations among different arrangements.
Stereospecific Synthesis of Cryptophycin 1

A brief stereospecific synthesis of cryptophycin 1 is described in which (R)-mandelic acid serves as the sole source of asymmetry for unit A. The key step is a hetero-Diels−Alder cycloaddition.
Brain and psychological determinants of placebo pill response in chronic pain patients.

The placebo response is universally observed in clinical trials of pain treatments, yet the individual characteristics rendering a patient a ‘placebo responder’ remain unclear. Here, in chronic back pain patients, we demonstrate using MRI and fMRI that the response to placebo ‘analgesic’ pills depends on brain structure and function. Subcortical limbic volume asymmetry, sensorimotor cortical thickness, and functional coupling of prefrontal regions, anterior cingulate, and periaqueductal gray were predictive of response. These neural traits were present before exposure to the pill and most remained stable across treatment and washout periods. Further, psychological traits, including interoceptive awareness and openness, were also predictive of the magnitude of response. These results shed light on psychological, neuroanatomical, and neurophysiological principles determining placebo response in RCTs in chronic pain patients, and they suggest that the long-term beneficial effects of placebo, as observed in clinical settings, are partially predictable.
C–F Activation of hydrofluorocarbons (HFCs) mediated by aluminum reagents

Abstract In the presence of various aluminum reagents, the difluoromethylene group (CF 2 ) in selected hydrofluorocarbons (HFCs) undergoes a Friedel–Crafts type reaction with aromatic compounds in satisfactory yields.
CARTILAGINEOL, THE FOURTH LINEAGE OF LAURENCIA-DERIVED POLYHALOGENATED CHAMIGRENE

Abstract A sevised regiochemistry and the absolute configuration are established for cartilagineol (formerly allo-isoobtusol). This revised structure renders cartilagineol the first example of the fourth stereochemical type of Laurencia-derived polyhalogenated chamigrene in support of current biogenetic theory. Earlier misassigned NMR data for ma'ilione is corrected.
Universal Light-Sheet Generation with Field Synthesis

We introduce field synthesis, a theorem and method that can be used to synthesize any scanned or dithered light sheet, including those used in lattice light-sheet microscopy (LLSM), from an incoherent superposition of one-dimensional intensity distributions. Compared to LLSM, this user-friendly and modular approach offers a simplified optical design, higher light throughput and simultaneous multicolor illumination. Further, field synthesis achieves lower rates of photobleaching than light sheets generated by lateral beam scanning.
Effect of improving the lattice gauge action on QCD topology

We use lattice topology as a laboratory to-compare the Wilson action (WA) with the Symanzik-Weisz (SW) action constructed from a combination of (1 x 1) and (1 x 2) Wilson loops, and the estimate of the renormalization trajectory (RT)[1] from a renormalization group transformation (RGT) which also includes higher representations of the (1 x 1) loop. Topological charges are computed using the geometric (Luscher`s) and plaquette methods on the uncooled lattice, and also by using cooling to remove ultraviolet artifacts. We show that as the action improves by approaching the RT, the topological charges for individual configurations, computed using these three methods become more highly correlated, suggesting that artificial lattice renormalizations to the topological susceptibility can be suppressed by improving the action.
Total synthesis of (+/-)fasicularin via a 2-amidoacrolein cycloaddition.

The total synthesis of the cytotoxin fasicularin is described. The key steps include the following: (1) an intermolecular Diels−Alder cycloaddition of a 2-(triflamido)acrolein with the dioxolane ketal of trideca-1,3-dien-7-one to establish the trans-perhydroisoquinoline stereochemistry, (2) a stereoelectronically controlled hydride addition to a N(1)−C(2) iminium ion to introduce the equatorial hexyl substituent, and (3) elaboration of the pyrido ring by an internal aldol reaction.
Acid-catalyzed rearrangements of some 1,6-diketones

Abstract 2-(4-Ketoalkyl)cyclopentanones, when subjected to the action of 1 M H 2 SO 4 at reflux, undergo ring cleavage and formation reactions to give 4-(1-cyclopentenyl)butanoic acids. When the starting ring is six-membered instead, a bicyclic enone results. Mechanistic discussion and some experimental tests are put forth.
Constraints on the Early Terrestrial Surface UV Environment Relevant to Prebiotic Chemistry

Abstract The UV environment is a key boundary condition to abiogenesis. However, considerable uncertainty exists as to planetary conditions and hence surface UV at abiogenesis. Here, we present two-stream multilayer clear-sky calculations of the UV surface radiance on Earth at 3.9 Ga to constrain the UV surface fluence as a function of albedo, solar zenith angle (SZA), and atmospheric composition. Variation in albedo and latitude (through SZA) can affect maximum photoreaction rates by a factor of >10.4; for the same atmosphere, photoreactions can proceed an order of magnitude faster at the equator of a snowball Earth than at the poles of a warmer world. Hence, surface conditions are important considerations when computing prebiotic UV fluences. For climatically reasonable levels of CO2, fluence shortward of 189 nm is screened out, meaning that prebiotic chemistry is robustly shielded from variations in UV fluence due to solar flares or variability. Strong shielding from CO2 also means that the UV surface ...
Randomized Experimental Design via Geographic Clustering

Web-based services often run randomized experiments to improve their products. A popular way to run these experiments is to use geographical regions as units of experimentation, since this does not require tracking of individual users or browser cookies. Since users may issue queries from multiple geographical locations, geo-regions cannot be considered independent and interference may be present in the experiment. In this paper, we study this problem, and first present GeoCUTS, a novel algorithm that forms geographical clusters to minimize interference while preserving balance in cluster size. We use a random sample of anonymized traffic from Google Search to form a graph representing user movements, then construct a geographically coherent clustering of the graph. Our main technical contribution is a statistical framework to measure the effectiveness of clusterings. Furthermore, we perform empirical evaluations showing that the performance of GeoCUTS is comparable to hand-crafted geo-regions with respect to both novel and existing metrics.
Hydrothermal chemistry, structures, and luminescence studies of alkali hafnium fluorides.

This paper describes the hydrothermal chemistry of alkali hafnium fluorides, including the synthesis and structural characterization of five new alkali hafnium fluorides. Two ternary alkali hafnium fluorides are described: Li(2)HfF(6) in space group P31m with a = 4.9748(7) A and c = 4.6449(9) A and Na(5)Hf(2)F(13) in space group C2/m with a = 11.627(2) A, b = 5.5159(11) A, and c = 8.4317(17) A. Three new alkali hafnium oxyfluorides are also described: two fluoroelpasolites, K(3)HfOF(5) and (NH(4))(3)HfOF(5), in space group Fm3m with a = 8.9766(10) and 9.4144(11) A, respectively, and K(2)Hf(3)OF(12) in space group R3m with a = 7.6486(11) A and c = 28.802(6) A. Infrared (IR) spectra were obtained for the title solids to confirm the structure solutions. Comparison of these materials was made based on their structures and synthesis conditions. The formation of these species in hydrothermal fluids appears to be dependent upon both the concentration of the alkali fluoride mineralizer solution and the reaction temperature. Both X-ray and visible fluorescence studies were conducted on compounds synthesized in this study and showed that fluorescence was affected by a variety of factors, such as alkali metal size, the presence/absence of oxygen in the compound, and the coordination environment of Hf(4+).
Natural and Unnatural Terpenoid Precursors of Insect Juvenile Hormone

The biosynthesis of insect juvenile hormone (JH) is due, in part, to the precise head-to-tail coupling of allylic and homoallylic diphosphate substrates, as catalyzed by one or more prenyltransferases. To better understand this enzyme's role in JH production, homodimethylallyl diphosphate and both the natural and unnatural homologs of geranyl diphosphate have been prepared as potential substrates for insect prenyltransferase. These latter materials were constructed in a convergent manner by olefination of the corresponding trisnoraldehydes obtained from either terminal oxidative cleavage of geraniol or higher-order cuprate conjugate addition to acrolein. To aid in characterizing the nature of the terpenoid skeletons formed from our in vitro studies, homologous derivatives of farnesol were also prepared by anion coupling of the geranyl derivatives to either C5 or C6 allylic bromides. The preparation of these materials and the results of incubations with larval corpora allata homogenates of the lepidopteran...
Microwave Heating in Synthesis: Preparation of Allyldiphenylphosphine Oxide

Abstract A new one-pot synthesis of allyldiphenyl-phosphine oxide has been developed using a tandem Sn2′ / Michaelis-Arbuzov sequence. The application of microwave heating lowers the reaction time significantly.
cis-Enhanced cyclopropanation catalysts: reaction chemistry of three isomers of Rh2[N(C6H5)COCH3]4

Abstract The catalytic activities of three structural isomers of Rh 2 [N(C 6 H 5 )COCH 3 ] 4 in cyclopropanation reactions were surveyed. These studies showed cis cyclopropanation selectivity with bulky alkenes for 2,2- cis - and 2,2- trans -Rh 2 [N(C 6 H 5 )COCH 3 ] 4 .
Overfitting in Synthesis: Theory and Practice

In syntax-guided synthesis (SyGuS), a synthesizer’s goal is to automatically generate a program belonging to a grammar of possible implementations that meets a logical specification. We investigate a common limitation across state-of-the-art SyGuS tools that perform counterexample-guided inductive synthesis (CEGIS). We empirically observe that as the expressiveness of the provided grammar increases, the performance of these tools degrades significantly.
A maximum principle for Hermitian (and other) metrics

We consider homomorphisms of hermitian holomorphic Hilbert bundles. Assuming the homomorphism decreases curvature, we prove that its pointwise norm is plurisubharmonic.
Distributed Binary Detection Over Fading Channels: Cooperative and Parallel Architectures

This paper considers the problem of binary distributed detection of a known signal in correlated Gaussian sensing noise in a wireless sensor network, where sensors are restricted to using the likelihood ratio test (LRT) and communicating with the fusion center (FC) over bandwidth-constrained channels that are subject to fading and noise. To mitigate the deteriorating effect of fading encountered in the conventional parallel fusion architecture, in which sensors directly communicate with the FC, we propose new fusion architectures that enhance the detection performance, via harvesting cooperative gain (so-called “decision diversity gain”). In particular, we propose 1) cooperative fusion architecture with Alamouti's space–time coding scheme at sensors, 2) cooperative fusion architecture with signal fusion at sensors, and 3) parallel fusion architecture with local threshold changing at sensors. For these schemes, we derive the LRT and majority fusion rules at the FC and provide upper bounds on the average error probabilities for homogeneous sensors, subject to uncorrelated Gaussian sensing noise, in terms of signal-to-noise ratio (SNR) of communication and sensing channels. Our simulation results indicate that when the FC employs the LRT rule, except for low communication SNR and moderate/high sensing SNR, performance improvement is feasible with the new fusion architectures. When the FC utilizes the majority rule, such an improvement is possible, except for high sensing SNR.
Optimal Energy Consumption Forecast for Grid Responsive Buildings: A Sensitivity Analysis

It is envisioned that building systems will become active participants in the smart grid operation by controlling their energy consumption to optimize complex criteria beyond ensuring local end-use comfort satisfaction. A forecast of the building energy consumption will be necessary to enable integration between building and grid operation. Such forecast will be affected by parametric and measurement uncertainty. In this paper we develop a methodology for quantifying the sensitivity of optimal hourly energy consumption forecasts to various sources model and measurement uncertainty. We demonstrate the approach for a building heating ventilation and air conditioning (HVAC) system use-case.
Affine Type $A$ Geometric Crystal on the Grassmannian

Abstract We construct a type A n − 1 ( 1 ) geometric crystal on the variety Gr ( k , n ) × C × , and show that it tropicalizes to the disjoint union of the Kirillov-Reshetikhin crystals corresponding to rectangular tableaux with n − k rows. A key ingredient in our construction is the Z / n Z symmetry on the Grassmannian coming from cyclically shifting the basis of the underlying vector space. We show that a twisted version of this symmetry tropicalizes to combinatorial promotion. Additionally, we use the loop group GL n ( C ( λ ) ) to define a unipotent crystal which induces our geometric crystal. We use this unipotent crystal to study the geometric analogues of two symmetries of rectangular tableaux.
Translation invariant mean field games with common noise

This note highlights a special class of mean field games in which the coefficients satisfy a convolution-type structural condition. A mean field game of this type with common noise is related to a certain mean field game without common noise by a simple transformation, which permits a tractable construction of a solution of the problem with common noise from a solution of the problem without. This yields new existence results for common noise problems, notably allowing controlled volatility, as well as new uniqueness results for problems without common noise.
Quantum Supremacy and the Complexity of Random Circuit Sampling

A critical goal for the field of quantum computation is quantum supremacy - a demonstration of any quantum computation that is prohibitively hard for classical computers. It is both a necessary milestone on the path to useful quantum computers as well as a test of quantum theory in the realm of high complexity. A leading near-term candidate, put forth by the Google/UCSB team, is sampling from the probability distributions of randomly chosen quantum circuits, called Random Circuit Sampling (RCS). While RCS was defined with experimental realization in mind, we give strong complexity-theoretic evidence for the classical hardness of RCS, placing it on par with the best theoretical proposals for supremacy. Specifically, we show that RCS satisfies an average-case hardness condition - computing output probabilities of typical quantum circuits is as hard as computing them in the worst-case, and therefore #P-hard. Our reduction exploits the polynomial structure in the output amplitudes of random quantum circuits, enabled by the Feynman path integral. In addition, it follows from known results that RCS also satisfies an anti-concentration property, namely that errors in estimating output probabilities are small with respect to the probabilities themselves. This makes RCS the first proposal for quantum supremacy with both of these properties. We also give a natural condition under which an existing statistical measure, cross-entropy, verifies RCS, as well as describe a new verification measure which in some formal sense maximizes the information gained from experimental samples.
Interpretation of Neural Networks is Fragile

In order for machine learning to be trusted in many applications, it is critical to be able to reliably explain why the machine learning algorithm makes certain predictions. For this reason, a variety of methods have been developed recently to interpret neural network predictions by providing, for example, feature importance maps. For both scientific robustness and security reasons, it is important to know to what extent can the interpretations be altered by small systematic perturbations to the input data, which might be generated by adversaries or by measurement biases. In this paper, we demonstrate how to generate adversarial perturbations that produce perceptively indistinguishable inputs that are assigned the same predicted label, yet have very different interpretations. We systematically characterize the robustness of interpretations generated by several widely-used feature importance interpretation methods (feature importance maps, integrated gradients, and DeepLIFT) on ImageNet and CIFAR-10. In all cases, our experiments show that systematic perturbations can lead to dramatically different interpretations without changing the label. We extend these results to show that interpretations based on exemplars (e.g. influence functions) are similarly susceptible to adversarial attack. Our analysis of the geometry of the Hessian matrix gives insight on why robustness is a general challenge to current interpretation approaches.
Shared high value research resources: The CamCAN human lifespan neuroimaging dataset processed on the open science grid

The CamCAN Lifespan Neuroimaging Dataset [1,2], Cambridge (UK) Centre for Ageing and Neuroscience, was acquired and processed beginning in December, 2016. The referee consensus solver deployed to the Open Science Grid [3,4] was used for this task. The dataset includes demographic and screening measures, a high-resolution MRI scan of the brain, and whole-head magnetoencephalographic (MEG) recordings during eyes closed rest (560 sec), a simple task (540 sec), and passive listening/viewing (140 sec). The data were collected from 619 neurologically normal individuals, ages 18–87. The processed results from the resting recordings are completed and available for download at http://stash.osgconnect.net/+krieger/. These constitute ≈1.7 TBytes of data including the location within the brain (1 mm resolution), time stamp (1 msec resolution), and 80 msec time course for each of 3.7 billion validated neuroelectric events, i.e. mean 6.1 million events for each of the 619 participants. The referee consensus solver provides high yield (mean 11,000 neuroelectric currents/sec; standard deviation (sd): 3500/sec) high confidence (p < 10−12 for each identified current) measures of the neuroelectric currents whose magnetic fields are detected in the MEG recordings. We describe the solver, the implementation of the solver deployed on the Open Science Grid, the workflow management system, the opportunistic use of high performance computing (HPC) resources to add computing capacity to the Open Science Grid reserved for this project, and our initial findings from the recently completed processing of the resting recordings. This required ≈14 million core hours, i.e. ≈40 core hours per second of data.
Generalizing Hamiltonian Monte Carlo with Neural Networks

We present a general-purpose method to train Markov chain Monte Carlo kernels, parameterized by deep neural networks, that converge and mix quickly to their target distribution. Our method generalizes Hamiltonian Monte Carlo and is trained to maximize expected squared jumped distance, a proxy for mixing speed. We demonstrate large empirical gains on a collection of simple but challenging distributions, for instance achieving a 106x improvement in effective sample size in one case, and mixing when standard HMC makes no measurable progress in a second. Finally, we show quantitative and qualitative gains on a real-world task: latent-variable generative modeling. We release an open source TensorFlow implementation of the algorithm.
Multi-View Graph Convolutional Network and Its Applications on Neuroimage Analysis for Parkinson's Disease.

Parkinson’s Disease (PD) is one of the most prevalent neurodegenerative diseases that affects tens of millions of Americans. PD is highly progressive and heterogeneous. Quite a few studies have been conducted in recent years on predictive or disease progression modeling of PD using clinical and biomarkers data. Neuroimaging, as another important information source for neurodegenerative disease, has also arisen considerable interests from the PD community. In this paper, we propose a deep learning method based on Graph Convolutional Networks (GCN) for fusing multiple modalities of brain images in relationship prediction which is useful for distinguishing PD cases from controls. On Parkinson’s Progression Markers Initiative (PPMI) cohort, our approach achieved 0.9537±0.0587 AUC, compared with 0.6443±0.0223 AUC achieved by traditional approaches such as PCA.
Dynamic Conic Finance via Backward Stochastic Difference Equations

We present an arbitrage free theoretical framework for modeling bid and ask prices of dividend paying securities in a discrete time setup using the theory of dynamic acceptability indices. In the first part of the paper we develop the theory of dynamic subscale invariant performance measures, on a general filtered probability space. We prove a representation theorem for such measures in terms of a family of dynamic convex risk measures, and we provide a representation of dynamic risk measures in terms of $g$-expectations, and solutions of backward stochastic difference equations with convex drivers. In the second part of the paper we discuss a market model for dividend paying securities by introducing the pricing operators that are defined in terms of dynamic acceptability indices, and we study various properties of these operators. Using these pricing operators, we define the bid and ask prices for the underlying securities and then for derivatives in this market. We show that the obtained market model i...
Four Classes of Morphogenetic Collective Systems

We studied the roles of morphogenetic principles— heterogeneity of components, dynamic differentiation/redifferentiation of components, and local information sharing among components—in the self-organization of morphogenetic collective systems. By incrementally introducing these principles to collectives, we defined four distinct classes of morphogenetic collective systems. Monte Carlo simulations were conducted using an extended version of the Swarm Chemistry model that was equipped with dynamic differentiation/re-differentiation and local information sharing capabilities. Self-organization of swarms was characterized by several kinetic and topological measurements, the latter of which were facilitated by a newly developed network-based method. Results of simulations revealed that, while heterogeneity of components had a strong impact on the structure and behavior of the swarms, dynamic differentiation/re-differentiation of components and local information sharing helped the swarms maintain spatially adjacent, coherent organization.
On almost-Fuchsian manifolds

Almost-Fuchsian manifold is a class of complete hyperbolic threemanifolds. A such three-manifold is a quasi-Fuchsian manifold that contains a closed incompressible minimal surface with principal curvatures everywhere in the range of (−1, 1). In such a manifold, the minimal surface is unique and embedded, hence one can parametrize these hyperbolic three-manifolds by their minimal surfaces. In this paper we obtain estimates on several geometric and analytical quantities of an almost-Fuchsian manifold M in terms of the data on the minimal surface. In particular, we obtain an upper bound for the hyperbolic volume of the convex core of M , and an upper bound on the Hausdorff dimension of the limit set associated to M . We also constructed a quasi-Fuchsian manifold which admits more than one minimal surface, and it does not admit a foliation of closed surfaces of constant mean curvature.
Noncommutative complete intersections

Abstract Several generalizations of a commutative ring that is a graded complete intersection are proposed for a noncommutative graded k-algebra; these notions are justified by examples from noncommutative invariant theory.
ANSAC: Adaptive Non-minimal Sample and Consensus

While RANSAC-based methods are robust to incorrect image correspondences (outliers), their hypothesis generators are not robust to correct image correspondences (inliers) with positional error (noise). This slows down their convergence because hypotheses drawn from a minimal set of noisy inliers can deviate significantly from the optimal model. This work addresses this problem by introducing ANSAC, a RANSAC-based estimator that accounts for noise by adaptively using more than the minimal number of correspondences required to generate a hypothesis. ANSAC estimates the inlier ratio (the fraction of correct correspondences) of several ranked subsets of candidate correspondences and generates hypotheses from them. Its hypothesis-generation mechanism prioritizes the use of subsets with high inlier ratio to generate high-quality hypotheses. ANSAC uses an early termination criterion that keeps track of the inlier ratio history and terminates when it has not changed significantly for a period of time. The experiments show that ANSAC finds good homography and fundamental matrix estimates in a few iterations, consistently outperforming state-of-the-art methods.
Combat Models for RTS Games

Game-tree search algorithms, such as Monte Carlo tree search, require access to a forward model (or “simulator”) of the game at hand. However, in some games such forward model is not readily available. This paper presents three forward models for two-player attrition games, which we call “combat models,” and show how they can be used to simulate combat in real-time strategy games. We also show how these combat models can be learned from replay data. We use STARCRAFT as our application domain. We report experiments comparing our combat models predicting combat results and their impact when used for tactical decisions during a real game.
Distribution Systems Hardening Against Natural Disasters

Distribution systems are often crippled by catastrophic damage caused by a natural disaster. Well-designed hardening can significantly improve the performance of postdisaster restoration operations. Such performance is quantified by a resilience measure associated with the operability trajectory. The distribution system hardening problem can be formulated as a two-stage stochastic problem, where the inner operational problem addresses the proper scheduling of postdisaster repairs and the outer problem the judicious selection of components to harden. We propose a deterministic single crew approximation with two solution methods, a mixed integer linear programming (MILP) formulation and a heuristic approach. We provide computational evidence on various IEEE test feeders, which illustrates that the heuristic approach provides near-optimal hardening solutions efficiently.