cssi/SciSciGPT-SciSciNet huggingface dataset:
Single cell RNA-seq study of wild type and Hox9,10,11 mutant developing uterus

The uterus is a remarkable organ that must guard against infections while maintaining the ability to support growth of a fetus without rejection. The Hoxa10 and Hoxa11 genes have previously been shown to play essential roles in uterus development and function. In this report we show that the Hoxa9,10,11, Hoxc9,10,11, Hoxd9,10,11 genes play a redundant role in the formation of uterine glands. In addition, we use single cell RNA-seq to create a high resolution gene expression atlas of the developing wild type mouse uterus. Cell types and subtypes are defined, for example dividing endothelial cells into arterial, venous, capillary, and lymphatic, while epithelial cells separate into luminal and glandular subtypes. Further, a surprising heterogeneity of stromal and myocyte cell types are identified. Transcription factor codes and ligand/receptor interactions are characterized. We also used single cell RNA-seq to globally define the altered gene expression patterns in all developing uterus cell types for two Hox mutants, with 8 or 9 mutant Hox genes. The mutants show a striking disruption of Wnt signaling as well as the Cxcl12/Cxcr4 ligand/receptor axis.
Diastereoselective synthesis of the trans-anti-cis-decahydro-as-indacene ring system via the transannular Diels-Alder reaction of a functionalized (E,E,E)-cyclododeca-1,6,8-triene

Abstract A stereoselective synthesis of trans-anti-cis decahydro-as-indacene 5 is described. The key step of this synthesis is the tandem Claisen ring contraction of the 16-membered macrolactone 3 followed by the transannular Diels-Alder reaction of the resulting (E,E,E)-cyclododeca-1,6,8-triene 4 .
How Rapidly Does the SH Radical React with N2O

The reaction of SH radical with N{sub 2}O was investigated by using two complementary experimental methods: (1) a pulsed photolysis apparatus where SH was detected via laser-induced fluorescence and (2) a discharge flow tube where SH was detected via chemical ionization mass spectrometry. The rate coefficient for this reaction, {kappa}{sub 1}, was found to be less than 5 x 10{sup {minus}16} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} at 298 K, in contrast to the large value reported in the literature. Secondary reactions were deduced to be unimportant in the system. Some possible reasons for the previously reported high value are presented. The low value of {kappa}{sub 1} makes the oxidation of SH by N{sub 2}O and removal of N{sub 2}O by SH unimportant in the earth's atmosphere.
Formation of retinal direction-selective circuitry initiated by starburst amacrine cell homotypic contact.

Our experience of the world relies on circuits spanning the sense organs and the brain that process information received through our senses. These circuits are made up of many different types of nerve cells that form connections with each other while the brain is developing. For these circuits to be set up properly, nerve cells have to be selective about how they connect with each other. However, researchers know little about how exactly nerve cells form the right connections, or about which genes and proteins are involved. One of the better understood circuits in the body is known as the ‘direction-selective circuit’. Found in the retina at the back of the eye of all backboned animals, this circuit’s task is to detect the direction that objects are moving. In the case of mice, scientists have identified all of the cells that make up the circuit, and know how they are all supposed to be connected together. This is a useful starting point for researchers to look in more detail at how nerve cells make the right connections during development to set up a working circuit. Ray et al. looked at how the direction-selective circuit forms in the retinas of young mice by genetically engineering cells to carry fluorescent proteins, or staining them with chemicals. This allowed the cells to be examined under a microscope at different points in their development. It turns out that one type of cell, known as the ‘starburst amacrine cell’ because of its firework-like shape, coordinates the formation of the whole direction-selective circuit. First, starburst cells branch out and touch each other. Next, they build a scaffold for the circuit with their branch-like extensions. Finally, other cell types follow this scaffold to form connections and complete the circuit. Ray et al. identified a protein called MEGF10 on the surface of starburst cells that tells the cells when they have made contact with each other. When starburst cells had MEGF10 taken away, or were prevented from contacting each other, they did not build a scaffold properly, and the circuit was less effective at detecting movement. It is possible that cells in other brain circuits use a similar method to form connections. Understanding more about how nerve cells form circuits will help researchers to work out what goes wrong in developmental disorders that affect vision, memory and learning. This knowledge would be helpful for designing new treatments for these conditions.
The enzymatic Baeyer-Villiger oxidation: synthesis of the C11–C16 subunit of ionomycin

Abstract An efficient synthesis of the C 11 –C 16 subunit of ionomycin from cis -3,5-dimethyl cyclohexanone using as the enzymatic Baeyer-Villiger oxidation to establish the correct absolute stereochemistry at C 12 and C 14 is reported.
Genome‐wide patterns of regulatory divergence revealed by introgression lines

Understanding the genetic basis for changes in transcriptional regulation is an important aspect of understanding phenotypic evolution. Using interspecific introgression lines, we infer the mechanisms of divergence in genome-wide patterns of gene expression between the nightshades Solanum pennellii and S. lycopersicum (domesticated tomato). We find that cis- and trans-regulatory changes have had qualitatively similar contributions to divergence in this clade, unlike results from other systems. Additionally, expression data from four tissues (shoot apex, ripe fruit, pollen, and seed) suggest that introgressed regions in these hybrid lines tend to be downregulated, while background (nonintrogressed) genes tend to be upregulated. Finally, we find no evidence for an association between the magnitude of differential expression in NILs and previously determined sterility phenotypes. Our results contradict previous predictions of the predominant role of cis- over trans-regulatory divergence between species, and do not support a major role for gross genome-wide misregulation in reproductive isolation between these species.
[HP(HNCH2CH2)3N]NO3 : an efficient homogeneous and solid-supported promoter for aza and thia-Michael reactions and for Strecker reactions

Abstract In the presence of a catalytic amount of an azaphosphatrane nitrate salt, amines and thiols react readily with Michael acceptors. The salt is also an efficient promoter for the one pot synthesis of α-amino and α-amidonitriles. By anchoring the salt to Merrifield Resin, a reusable heterogeneous catalyst is obtained for these reactions. Evidence is presented for catalysis being attributable solely to the NO3− ion.
Benzothiazines in organic synthesis: formation of a cyclopropane via neighboring group participation

Abstract In the course of a synthesis of the antitubercular natural product pseudopteroxazole, we discovered a highly diastereoselective cyclopropanation process. The reaction involved participation of a diene in the departure of a leaving group and could be conducted in high yield after optimization.
Salt-Templated Open Frameworks (CU-2): Novel Phosphates and Arsenates Containing M3(X2O7)22- (M = Mn, Cu; X = P, As) Micropores 5.3 Å and 12.7 Å in Diameter

We have recently isolated a novel family of salt-templated phosphates and arsenates, A2M3(X2O7)2·(salt) [where A = K, Rb, Cs; M = Mn, Cu; X = P, As]. The space-filling, charge-compensation alkali metal chloride salts can be removed conveniently without destroying the MXO framework. These materials (designated as CU-2-MXO) exhibit microporous structures (ca. 5.3 and 12.7 A in diameter) in which the active transition metal sites are distributed in a spatially uniform manner throughout the bulk. The salt lattice functions as a structure-directing template. The single-crystal structure shows that the large pore contains a remarkable ACl/CsCl lattice that consists of two interpenetrating, square antiprismatic columns of ions. In contrast to organically templated microporous solids, these new materials were synthesized by conventional solid-state reactions at high temperatures. Consequently, the resulting compounds can endure extensive heating to ca. 650 °C. These materials, in fact, possess the highest thermal...
Highly Stereoselective Formation of Cp*IrCl Complexes of N,N-Dimethylamino Acids

N,N-Dimethylamino acids serve as (N, O)-chelating monoanionic ligands to the prochiral fragment Cp*IrCl. A series of four such complexes and one Rh analog all were formed with diastereoselectivity of ≥50:≤1. The structure of the valine complex 5d (C17H29ClIrNO2) was analyzed at 298 K, from which a cis-arrangement of Cp* and valine side chain (i-Pr) was revealed. Solution NMR studies of 5d, aided by an unusual zero coupling between the two methine protons of the amino acid, showed that the structures in solution and the solid were very similar. The preference for the cis-oriented Cp* and amino acid side chain in 5 is attributed to a maximum number of gauche interactions in the metallacycle and its substituents, especially pronounced for N,N-disubstituted amino acids.
Acyclic Diastereoselection in Prochiral Radical Addition to Prochiral Olefins

The stereochemical preference (syn or anti) when prochiral radicals add to prochiral acceptors is of fundamental interest. The primary focus of this research was to determine which factors influence the relative stereochemistry between the β and γ chiral centers when these are formed concurrently. While moderate diastereoselectivity was found for addition of alkyl (6a−d) and α-alkoxy radicals (16a−c) (≤6:1 syn) to acceptors 4, 7, 8, 10, and 14, consistently high selectivity was observed with less reactive halogenated radicals (6f,g) (>15:1 anti). Steric influence in alkyl radical additions was difficult to evaluate due to decreased reactivity when using bulky reaction partners; however, more reactive α-alkoxy radicals, it was found that increasing steric bulk leads to moderate increases in selectivity. In addition, higher selectivity was observed when employing lanthanide Lewis acids whose environment (reactivity) was modified using achiral additives, suggesting a potentially simple means for selectivity ...
Palladium-catalyzed cyanation reactions of aryl chlorides

Abstract We have discovered an efficient cyanation of aryl chlorides which employs Pd 2 (dba) 3 , dppf and Zn as the catalyst and Zn(CN) 2 as the cyanide source. Both electron-deficient and electron-rich aryl chlorides are effectively cyanated under these conditions. This discovery represents the first successful palladium-catalyzed cyanation of both electron-deficient and electron-rich aryl chlorides.
Microtubules Provide a Viscoelastic Resistance to Myocyte Motion.

Abstract Background: Microtubules (MTs) buckle and bear load during myocyte contraction, a behavior enhanced by post-translational detyrosination. This buckling suggests a spring-like resistance against myocyte shortening, which could store energy and aid myocyte relaxation. Despite this visual suggestion of elastic behavior, the precise mechanical contribution of the cardiac MT network remains to be defined. Methods: Here we experimentally and computationally probe the mechanical contribution of stable MTs and their influence on myocyte function. We use multiple approaches to interrogate viscoelasticity and cell shortening in primary murine myocytes in which either MTs are depolymerized or detyrosination is suppressed and use the results to inform a mathematical model of myocyte viscoelasticity. Results: MT ablation by colchicine concurrently enhances both the degree of shortening and speed of relaxation, a finding inconsistent with simple spring-like MT behavior and suggestive of a viscoelastic mechanism. Axial stretch and transverse indentation confirm that MTs increase myocyte viscoelasticity. Specifically, increasing the rate of strain amplifies the MT contribution to myocyte stiffness. Suppressing MT detyrosination with parthenolide or via overexpression of tubulin tyrosine ligase has mechanical consequences that closely resemble colchicine, suggesting that the mechanical impact of MTs relies on a detyrosination-dependent linkage with the myocyte cytoskeleton. Mathematical modeling affirms that alterations in cell shortening conferred by either MT destabilization or tyrosination can be attributed to internal changes in myocyte viscoelasticity. Conclusions: The results suggest that the cardiac MT network regulates contractile amplitudes and kinetics by acting as a cytoskeletal shock-absorber, whereby MTs provide breakable cross-links between the sarcomeric and nonsarcomeric cytoskeleton that resist rapid length changes during both shortening and stretch.
Isomerization of 2-(2-Propenoxy)phenyllithium: Tandem anionic cyclization-γ-elimination

Abstract 2-(2-Propenoxy)phenyllithium ( 1 ), which may be prepared from the corresponding iodide by low-temperature lithium-iodine exchange, rearranges on warming in the presence of TMEDA via 5-exo cyclization to (2,3-dihydrobenzofuranyl)methyllithium ( 2 ) followed by γ-elimination to give variable amounts of the lithium salt of 2-(cyclopropyl)phenol ( 3 ).
Hypervalent Iodine-Mediated Vicinal Syn Diazidation: Application to the Total Synthesis of (±)-Dibromophakellstatin

The total synthesis of (±)-dibromophakellstatin is described. The molecule is constructed from a key syn-diazide, formed by a hypervalent iodine-mediated diazidation of a dihydrodipyrrolopyrazinone ring structure.
The Di-Photon Background to a Light Higgs Boson at the LHC

Abstract Recent years have seen a significant advance in our ability to calculate two-loop matrix elements. In this talk we describe an application of this breakthrough to improve our understanding of the background to the search for a light Higgs boson at the LHC. In particular, we focus on the QCD corrections to the gluon fusion subprocess gg → γγ , which forms an important component of the background in the di-photon channel. We find that the K factor for this subprocess is significantly smaller than estimated previously.
On the Design of LIL Tests for (Pseudo) Random Generators and Some Experimental Results

Random numbers have been one of the most useful objects in statistics, computer science, cryptography, modeling, simulation, and other applications though it is very difficult to construct true randomness. Many solutions (e.g., cryptographic pseudorandom generators) have been proposed to harness or simulate randomness and many statistical testing techniques have been proposed to determine whether a pseudorandom generator produces high quality randomness. NIST SP800-22 (2010) proposes the state of art testing suite for (pseudo) random generators to detect deviations of a binary sequence from randomness. On the one hand, as a counter example to NIST SP800-22 test suite, it is easy to construct functions that are considered as GOOD pseudorandom generators by NIST SP800-22 test suite though the output of these functions are easily distinguishable from the uniform distribution. Thus these functions are not pseudorandom generators by definition. On the other hand, NIST SP800-22 does not cover some of the important laws for randomness. Two fundamental limit theorems about random binary strings are the central limit theorem and the law of the iterated logarithm (LIL). Several frequency related tests in NIST SP800-22 cover the central limit theorem while no NIST SP800-22 test covers LIL. This paper proposes techniques to address the above challenges that NIST SP800-22 testing suite faces. Firstly, we propose statistical distance based testing techniques for (pseudo) random generators to reduce the above mentioned Type II errors in NIST SP800-22 test suite. Secondly, we propose LIL based statistical testing techniques, calculate the probabilities, and carry out experimental tests on widely used pseudorandom generators by generating around 30TB of pseudorandom sequences. The experimental results show that for a sample size of 1000 sequences (2TB), the statistical distance between the generated sequences and the uniform distribution is around 0.07 (with 0 for statistically indistinguishable and 1 for completely distinguishable) and the root-mean-square deviation is around 0.005. Though the statistical distance 0.07 and RMSD 0.005 are acceptable for some applications, for a cryptographic “random oracle”, the preferred statistical distance should be smaller than 0.03 and RMSD be smaller than 0.001 at the sample size 1000. These results justify the importance of LIL testing techniques designed in this paper. The experimental results in this paper are reproducible and the raw experimental data are available at author’s website.
Remote chiral induction in the thio-Claisen rearrangement of bicyclic thiolactams

Abstract A remote steric effect in the bicyclic lactam oxazolidine ring has been shown to affect the stereochemical outcome in the thio-Claisen rearrangement taking place in the piperidone ring.
A One-Step Synthesis of 2,3-Dihydro-4H-pyran-4-ones from 3-Ethoxy α,β-Unsaturated Lactones

Addition of diverse nucleophiles to the unsaturated lactone 2 that results from hetero Diels−Alder reaction of Brassard's diene 1 with aldehydes leads to an efficient and general approach to the synthesis of 2,3-dihydro-4H-pyran-4-ones 3.
Total Synthesis of Spirotryprostatin A, Leading to the Discovery of Some Biologically Promising Analogues

The total synthesis of the title compound has been accomplished. A key step involves the oxidative rearrangement of the β-carboline derivative to an oxindole via the action of N-bromosuccinimide. From this point, a diketopiperazine was introduced. A thiophenyl group served as a precursor of the isopropylidene function. Implementation of the same sort of chemistry starting with a methoxytryptophan derivative led to the parent structures. Furthermore, it was shown that the difficultly accessible isopropylidene side chain of spirotryprostatin A is not necessary for biological activity. Moreover, three analogues lacking the diketopiperazine system were shown to be quite active as cell cycle inhibitors.
Influence of the Lattice Parameter Difference between the Two Cubic Phases Formed in the 4 V Region on the Capacity Fading of Spinel Manganese Oxides

To develop a better understanding of the capacity-fading mechanisms of spinel lithium manganese oxides, the electrochemical properties, degree of manganese dissolution, and crystal chemistry of a number of singly substituted LiMn2-yMyO4 (M = Li, Al, Ti, Co, and Ni and 0 ≤ y ≤ 0.2) and doubly substituted LiMn2-y-zMyLizO4 (M = Ti, Co, and Ni, 0 ≤ y ≤ 0.1, and 0 ≤ z ≤ 0.1) oxides have been compared with those of LiMn2O4. The cation-substituted spinel manganese oxides show better electrochemical performances than LiMn2O4. Especially, the doubly substituted LiMn1.85Ni0.075Li0.075O4 exhibits excellent cyclability at both ambient and elevated temperatures with a capacity of around 100 mAh/g. It also exhibits remarkable rate capability and excellent capacity retention (>95%) after storage at 60 °C at various depths of discharge (DOD). Although the degree of manganese dissolution does not vary significantly, the spinel manganese oxides show a clear relationship between the percent capacity fade and the lattice par...
1-Mesityl-2,2,2-trifluoroethanol, an outstanding new chiral controller for catalyzed diels-alder reactions

Abstract The R2AlCl-catalyzed Diels-Alder reactions of cyclopentadiene with the (R)-1-mesityl-2,2,2-trifluoroethyl esters of acrylic and fumaric acid proceed with ⪢ 97:3 diastereoselectivity.
Challenges in the development of an efficient enzymatic process in the pharmaceutical industry

Despite the unparalleled opportunities that have emerged for biocatalysis over the last few years, there still exist challenges that will hinder the development of an efficient enzymatic process in the pharmaceutical industry. The challenges that will be described in this report include the throughput of an enzymatic process, downstream processing issues, and competition from other toolboxes. Perspectives on economic and intellectual property issues as well as the dynamics surrounding drug intermediates that fall into different stages of the overall drug development process will also be highlighted. Finally, literature examples will be used to offer solutions to those barriers faced by enzymatic processes attempting to transition into manufacturing scale.
A simple synthesis of 2,2′-bipyrroles from pyrrole

Abstract 2,2′-Bipyrroles, which are obvious precursors for the synthesis of 2,2′-bipyrrole-based natural products, are synthesized in three steps from pyrrole employing known pyrrolyl ketoalcohols by a sequential alcohol oxidation and Paal-Knorr pyrrole synthesis.
Phase Width and Site Preferences in the EuMgxGa4−x Series

A series of EuMgxGa4−x compounds were synthesized using high temperature, solid-state methods and characterized by both powder and single crystal X-ray diffraction. All compounds crystallize in the tetragonal BaAl4-type structure (space group I4/mmm, Z = 2, Pearson symbol tI10) with full occupancy of Ga at the apical atom (4e) site and mixed-occupancy of Mg and Ga at the basal atom (4d) site. Six compositions were analyzed by single crystal X-ray diffraction: EuMg0.21(1)Ga3.79(1), EuMg0.91(1)Ga3.09(1), EuMg1.22(1)Ga2.78(1), EuMg1.78(1)Ga2.22(1), EuMg1.84(1)Ga2.16(1), and EuMg1.94(1)Ga2.06(1). As the larger Mg atoms increasingly replace Ga atoms at the basal site in EuMgxGa4−x, the a-axis lengths at first decrease and then increase, while the c-axis lengths increase monotonically along the series. The phase width of the BaAl4-type EuMgxGa4−x series is identified to be 0 ≤ x ≤ 1.94(1), a range which corresponds to 12.06(1)-14 valence electrons per formula unit, and can be understood by their electronic structures using density of states (DOS) curves calculated by tight-binding calculations. Mg substitution for Ga at the basal site is consistent with the site preferences for mixed metals on the three-dimensional framework of the BaAl4-structure based on both electronegativities and sizes, and provides the rationale for the unusual behavior in lattice parameters. The observed site preference was also rationalized by total electronic energies calculated for two different coloring schemes.
Asymmetric Synthesis of Chiral Fluorinated Compounds Using N-Acyloxazolidinones

A variety of optically active fluorinated molecules have been prepared by diastereoselective reactions of chiral N-acyloxazolidinones. The trifluoromethyl radical generated from iodotrifluoromethane with a radical initiator, triethylborane, reacts on the si-face of the lithium enolates of the oxazolidinones with good diastereomeric excess. The perfluoroalkylation and ethoxycarbonyldifluoromethylation of the lithium enolates mediated by triethylborane also proceeds diastereoselectively via a radical mechanism. The bromodifluoromethylation of the lithium enolates proceeds not via a radical mechanism involving bromodifluoromethyl radical but via an ionic chain mechanism involving the insertion of difluorocarbene. The Evans aldol reaction of hexafluoroacetone and trifluoroacetaldehyde causes complete reversal of diastereofacial selectivity. The boron enolate derived from chiral N-acyloxazolidinones reacts with trifluoroacetaldehyde to give anti and “non-Evans” syn aldols with stereoselectivity in the range of 7 : 317 : 3. This unexpected and usual reversal of π-face selectivity was reproduced by semiempirical molecular orbital calculations.
Total Synthesis of the Four Enantiomerically Pure Diastereomers of 8-F2t-Isoprostane

Syntheses of the four enantiomerically pure diastereomers of 8-F2t-isoprostane (5−8) are described. The key to this approach was to prepare the racemic alcohol 9 in high diastereomeric purity and t...
A fast and integrative algorithm for clustering performance evaluation in author name disambiguation

Clustering results in author name disambiguation are often evaluated by measures such as Cluster-F, K-metric, Pairwise-F, Splitting and Lumping Error, and B-cubed. Although these measures have different evaluation approaches, this paper shows that they can be calculated in a single framework by a set of common steps that compare truth and predicted clusters through two hash tables recording information about name instances with their predicted cluster indices and frequencies of those indices per truth cluster. This integrative calculation reduces greatly calculation runtime, which is scalable to a clustering task involving millions of name instances within a few seconds. During the integration process, B-cubed and K-metric are shown to produce the same precision and recall scores. In addition, name instance pairs for Pairwise-F are counted using a heuristic, which enables the proposed method to surpass a state-of-the-art algorithm in speedy calculation. Details of the integrative calculation are described with examples and pseudo-code to assist scholars to implement each measure easily and validate the correctness of implementation. The integrative calculation will help scholars compare similarities and differences of multiple measures before they select ones that characterize best the clustering performances of their disambiguation methods.
Total synthesis of (-)-salicylihalamide A.

A 16-step synthesis of the novel cytotoxin salicylihalamide A (1E) has been achieved in 3.3% overall yield using ring closing metathesis to generate the macrolide and addition of (1Z,3Z)-hexadienylcuprate (2), which was generated in situ from ethylcuprate and acetylene, to alkenyl isocyanate 3 to form the side chain.
Tempo of gene regulation in wild and cultivated Vitis species shows coordination between cold deacclimation and budbreak

Abstract Dormancy release, loss of cold hardiness and budbreak are critical aspects of the annual cycle of deciduous perennial plants. Molecular control of these processes is not fully understood, and genotypic variation may be important for climate adaptation. To gain greater understanding of these processes, single-node cuttings from wild (Vitis amurensis, V. riparia) and cultivated Vitis genotypes (V. vinifera ‘Cabernet Sauvignon’, ‘Riesling’) were collected from the vineyard during winter and placed under forcing conditions. Cold hardiness was measured daily, and buds were collected for gene expression analysis until budbreak. Wild Vitis genotypes had faster deacclimation and budbreak than V. vinifera. Temperature-sensing related genes were quickly and synchronously differentially expressed in all genotypes. Significant changes in the pattern of expression changes for eight major metabolic and hormone related pathways were seen across all genotypes. Downregulation of ABA synthesis appears to play an important role in loss of cold hardiness and budbreak in all genotypes. This role was validated through an observed halt in cold hardiness loss of ‘Riesling’ buds treated with exogenous ABA. The gene expression cascade that occurs during deacclimation and budbreak phenology of fast (wild) and slow (cultivated) grapevines appears coordinated and temporally conserved within these phenotypes.
Investor reaction to economic sanctions: the case of Russian Global Depositary Receipts

We examine the impact that the economic sanctions imposed by the Western community on the Russian economy in March 2014 have had on the pricing of Global Depositary Receipts (GDRs) traded in London. We document that following the first announcement of the imposition of sanctions, the returns of Russian GDRs increased in the case of both the Moscow Exchange and London listings, indicating an enhanced risk of trading with Russian securities. This effect was more pronounced in the case of London listings compared to local listings, which resulted in an overall decrease in the returns spread between the GDR and underlying home market shares. In contrast, we do not find evidence that imposition of sanctions affected turnover by volume of home or London-based GDR trades around the sanctions announcement, suggesting that investors did not pull out of Russian GDRs, but instead, reassessed investment risks associated with Russian securities. Last, our findings provide no evidence of a moderating impact on pricing of Russian GDRs by the two mechanisms that are expected to be indicative of enhanced (decreased) risks for GDRs, namely, state ownership (presence of foreign nationals on boards of directors). Our study contributes to the debate on the importance of complex assessment of outcomes of international sanctions on individual economies and firms.
The Kinetics of Nucleotide Binding to Isolated Chlamydomonas Axonemes Using UV-TIRF Microscopy.

Abstract Cilia and flagella are long, slender organelles found in many eukaryotic cells, where they have sensory, developmental, and motile functions. All cilia and flagella contain a microtubule-based structure called the axoneme. In motile cilia and flagella, which drive cell locomotion and fluid transport, the axoneme contains, along most of its length, motor proteins from the axonemal dynein family. These motor proteins drive motility by using energy derived from the hydrolysis of ATP to generate a bending wave, which travels down the axoneme. As a first step toward visualizing the ATPase activity of the axonemal dyneins during bending, we have investigated the kinetics of nucleotide binding to axonemes. Using a specially built ultraviolet total internal reflection fluorescence microscope, we found that the fluorescent ATP analog methylanthraniloyl ATP (mantATP), which has been shown to support axonemal motility, binds all along isolated, immobilized axonemes. By studying the recovery of fluorescence after photobleaching, we found that there are three mantATP binding sites: one that bleaches rapidly (time constant ≈ 1.7 s) and recovers slowly (time constant ≈ 44 s), one that bleaches with the same time constant but does not recover, and one that does not bleach. By reducing the dynein content in the axoneme using mutants and salt extraction, we provide evidence that the slow-recovering component, but not the other components, corresponds to axonemal dyneins. The recovery rate of this component, however, is too slow to be consistent with the activation of beating observed at higher mantATP concentrations; this indicates that the dyneins may be inhibited due to their immobilization at the surface. The development of this method is a first step toward direct observation of the traveling wave of dynein activity.
Identifying the Effect of Political Rumor Diffusion Using Variations in Survey Timing

Despite growing concerns about the diffusion of political rumors, researchers often lack the means to estimate their effects. Field experiments seem infeasible due to ethical issues. Survey experiments typically invoke strong assumptions about homogeneous treatment effects across subjects and settings. We argue that exploiting temporal overlap between rumor circulations and survey interviews can be a useful alternative. We focus on an accidental and sudden spread of “Obama-is-a-Muslim” myths in September 2008. Using a difference-in-difference strategy that compares over-time belief changes of those interviewed for the September wave of the 2008–2009 American National Election Studies surveys before the rumor circulation and afterwards, we find that this event increased people’s belief that Barak Obama is a Muslim by 4 to 8 percentage points. To rule out various alternative explanations, we show that the treatment and control groups changed in parallel across waves in terms of an extensive set of placebo variables including political knowledge, other political misperception, and general attitudes toward Obama.
Codegree Conditions for Tiling Complete k-Partite k-Graphs and Loose Cycles

Given two k-graphs (k-uniform hypergraphs) F and H, a perfect F-tiling (or F-factor) in H is a set of vertex-disjoint copies of F that together cover the vertex set of H. For all complete k-partite k-graphs K, Mycroft proved a minimum codegree condition that guarantees a K-factor in an n-vertex k-graph, which is tight up to an error term o(n). In this paper we improve the error term in Mycroft’s result to a sublinear term that relates to the Turan number of K when the differences of the sizes of the vertex classes of K are co-prime. Furthermore, we find a construction which shows that our improved codegree condition is asymptotically tight in infinitely many cases, thus disproving a conjecture of Mycroft. Finally, we determine exact minimum codegree conditions for tiling K(k)(1, … , 1, 2) and tiling loose cycles, thus generalizing the results of Czygrinow, DeBiasio and Nagle, and of Czygrinow, respectively.
The Return on Sustainability Investment (ROSI): Monetizing Financial Benefits of Sustainability Actions in Companies

Practitioners and researchers struggle with valuing the return on sustainability investment (ROSI). We apply a five-step methodology that systematically monetizes sustainability actions to answer a key question: Do sustainable practices lead to a positive financial return for the business? We demonstrate the versatility of this methodology by monetizing potential and realized financial benefits via mediating factors (i.e., financial drivers) across two types of industries: Brazilian beef supply chains that committed to deforestation-free beef and the automotive industry, where companies were working to make manufacturing operations more sustainable. The companies participating in our cases generated substantial value from implementing sustainability strategies. The beef supply chain yielded a potential net present value (NPV) between 0.01 to 12% of annual revenue, depending on the supply chain segment. For one automotive company, the five-year NPV based on realized benefits was 12% of annual revenue. Our ROSI methodology guides managers to better value sustainability’s financial benefits. Ultimately, monetizing sustainability can lead to a competitive advantage and shared value for multiple stakeholders.
Provable Efficient Online Matrix Completion via Non-convex Stochastic Gradient Descent

Matrix completion, where we wish to recover a low rank matrix by observing a few entries from it, is a widely studied problem in both theory and practice with wide applications. Most of the provable algorithms so far on this problem have been restricted to the offline setting where they provide an estimate of the unknown matrix using all observations simultaneously. However, in many applications, the online version, where we observe one entry at a time and dynamically update our estimate, is more appealing. While existing algorithms are efficient for the offline setting, they could be highly inefficient for the online setting. In this paper, we propose the first provable, efficient online algorithm for matrix completion. Our algorithm starts from an initial estimate of the matrix and then performs non-convex stochastic gradient descent (SGD). After every observation, it performs a fast update involving only one row of two tall matrices, giving near linear total runtime. Our algorithm can be naturally used in the offline setting as well, where it gives competitive sample complexity and runtime to state of the art algorithms. Our proofs introduce a general framework to show that SGD updates tend to stay away from saddle surfaces and could be of broader interests to other non-convex problems.
Two families of monogenic $S_4$ quartic number fields

Consider the integral polynomials $f_{a,b}(x)=x^4+ax+b$ and $g_{c,d}(x)=x^4+cx^3+d$. Suppose $f_{a,b}(x)$ and $g_{c,d}(x)$ are irreducible, $b\mid a$, and the integers $b$, $d$, $256d-27c^4$, and $\dfrac{256b^3-27a^4}{\gcd(256b^3,27a^4)}$ are all square-free. Using the Montes algorithm, we show that a root of $f_{a,b}(x)$ or $g_{c,d}(x)$ defines a monogenic extension of $\mathbb{Q}$ and serves as a generator for a power integral basis of the ring of integers. In fact, we show monogeneity for slightly more general families. Further, we obtain lower bounds on the density of polynomials generating monogenic $S_4$ fields within the families $f_{b,b}(x)$ and $g_{1,d}(x)$.
Interpolating conditional density trees

Joint distributions over many variables are frequently modeled by decomposing them into products of simpler, lower-dimensional conditional distributions, such as in sparsely connected Bayesian networks. However, automatically learning such models can be very computationally expensive when there are many datapoints and many continuous variables with complex nonlinear relationships, particularly when no good ways of decomposing the joint distribution are known a priori. In such situations, previous research has generally focused on the use of discretization techniques in which each continuous variable has a single discretization that is used throughout the entire network. In this paper, we present and compare a wide variety of tree-based algorithms for learning and evaluating conditional density estimates over continuous variables. These trees can be thought of as discretizations that vary according to the particular interactions being modeled; however, the density within a given leaf of the tree need not be assumed constant, and we show that such nonuniform leaf densities lead to more accurate density estimation. We have developed Bayesian network structure-learning algorithms that employ these tree-based conditional density representations. and we show that they can be used to practically learn complex joint prob ability models over dozens of continuous variables from thousands of datapoints. We focus on finding models that are simultaneously accurate, fast to learn, and fast to evaluate once they are learned.
Bounds on eigenfunctions of semiclassical operators with double characteristics

Author(s): Krupchyk, Katya; Uhlmann, Gunther | Abstract: We obtain sharp uniform bounds on the low lying eigenfunctions for a class of semiclassical pseudodifferential operators with double characteristics and complex valued symbols, under the assumption that the quadratic approximations along the double characteristics are elliptic.
Local times of stochastic differential equations driven by fractional Brownian motions

Abstract In this paper, we study the existence and (Holder) regularity of local times of stochastic differential equations driven by fractional Brownian motions. In particular, we show that in one dimension and in the rough case H 1 / 2 , the Holder exponent (in t ) of the local time is 1 − H , where H is the Hurst parameter of the driving fractional Brownian motion.
The Wedge-of-the-edge Theorem: Edge-of-the-wedge Type Phenomenon Within the Common Real Boundary

The edge-of-the-wedge theorem in several complex variables gives the analytic continuation of functions defined on the poly upper half plane and the poly lower half plane, the set of points in that are positively oriented with some small overlap, the functions must analytically continue to a neighborhood of that overlap of a fixed size not depending of the size of the overlap.
Tractable Learning and Inference for Large-Scale Probabilistic Boolean Networks

Probabilistic Boolean networks (PBNs) have previously been proposed so as to gain insights into complex dynamical systems. However, identification of large networks and their underlying discrete Markov chain which describes their temporal evolution still remains a challenge. In this paper, we introduce an equivalent representation for PBNs, the stochastic conjunctive normal form network (SCNFN), which enables a scalable learning algorithm and helps predict long-run dynamic behavior of large-scale systems. State-of-the-art methods turn out to be 400 times slower for middle-sized networks (i.e., containing 100 nodes) and incapable of terminating for large networks (i.e., containing 1000 nodes) compared to the SCNFN-based learning, when attempting to achieve comparable accuracy. In addition, in contrast to the currently used methods which introduce strict restrictions on the structure of the learned PBNs, the hypothesis space of our training paradigm is the set of all possible PBNs. Moreover, SCNFNs enable efficient sampling so as to statistically infer multistep transition probabilities which can provide information on the activity levels of individual nodes in the long run. Extensive experimental results showcase the scalability of the proposed approach both in terms of sample and runtime complexity. In addition, we provide examples to study large and complex cell signaling networks to show the potential of our model. Finally, we suggest several directions for future research on model variations, theoretical analysis, and potential applications of SCNFNs.
Global viscosity solutions of generalized Kähler-Ricci flow

We apply ideas from viscosity theory to establish the existence of a unique global weak solution to the generalized Kahler-Ricci flow in the setting of commuting complex structures. Our results are restricted to the case of a smooth manifold with smooth background data. We discuss the possibility of extending these results to more singular settings, pointing out a key error in the existing literature on viscosity solutions to complex Monge-Ampere equations/Kahler-Ricci flow.
Unbounded topologies and uo-convergence in locally solid vector lattices

Abstract Suppose X is a vector lattice and there is a notion of convergence x α → σ x in X. Then we can speak of an “unbounded” version of this convergence by saying that x α → u σ x if | x α − x | ∧ u → σ 0 for every u ∈ X + . In the literature, the unbounded versions of the norm, order and absolute weak convergence have been studied. Here we create a general theory of unbounded convergence but with a focus on uo-convergence and those convergences deriving from locally solid topologies. We will see that, not only do the majority of recent results on unbounded norm convergence generalize, but they do so effortlessly. Not only that, but the structure of unbounded topologies is clearer without a norm. We demonstrate this by removing metrizability, completeness, and local convexity from nearly all arguments, while at the same time making the proofs simpler and more general. We also give characterizations of minimal topologies in terms of unbounded topologies and uo-convergence.
On characters of inductive limits of symmetric groups

Abstract In the paper we completely describe characters (central positive-definite functions) of simple locally finite groups that can be represented as inductive limits of (products of) symmetric groups under block diagonal embeddings. Each such group G defines an infinite graded graph that encodes the embedding scheme. The group G acts on the space X of infinite paths of the associated graph by changing initial edges of paths. Assuming the finiteness of the set of ergodic measures for the system ( X , G ) , we establish that each non-regular indecomposable character χ : G → C is uniquely determined by the formula χ ( g ) = μ 1 ( Fix ( g ) ) α 1 ⋯ μ k ( Fix ( g ) ) α k , where μ 1 , … , μ k are G-ergodic measures, Fix ( g ) = { x ∈ X : g x = x } , and α 1 , … , α k ∈ { 0 , 1 , … } . We illustrate our results on the group of rational permutations of the unit interval.
Peak Nothing: Recent Trends in Mineral Resource Production

The Hubbert-type analysis used to analyze the production history of oil is applied here to other raw materials. Many resources commonly thought of as being close to “peaking” such as lithium, helium, copper, and the rare earth elements, show no evidence of logistic behavior at any point in their production histories. Although many resources have exhibited logistic behavior in the past, many now show exponential or superexponential growth. In most cases, the transition has occurred in the last ten to twenty years.
Breaking Locality Accelerates Block Gauss-Seidel

Recent work by Nesterov and Stich showed that momentum can be used to accelerate the rate of convergence for block Gauss-Seidel in the setting where a fixed partitioning of the coordinates is chosen ahead of time. We show that this setting is too restrictive, constructing instances where breaking locality by running non-accelerated Gauss-Seidel with randomly sampled coordinates substantially outperforms accelerated Gauss-Seidel with any fixed partitioning. Motivated by this finding, we analyze the accelerated block Gauss-Seidel algorithm in the random coordinate sampling setting. Our analysis captures the benefit of acceleration with a new data-dependent parameter which is well behaved when the matrix sub-blocks are well-conditioned. Empirically, we show that accelerated Gauss-Seidel with random coordinate sampling provides speedups for large scale machine learning tasks when compared to non-accelerated Gauss-Seidel and the classical conjugate-gradient algorithm.
Solution of Linear Ill-Posed Problems Using Random Dictionaries

In the present paper, we consider an application of overcomplete dictionaries to the solution of general ill-posed linear inverse problems. In the context of regression problems, there has been an enormous amount of effort to recover an unknown function using such dictionaries. One of the most popular methods, lasso, and its versions, is based on minimizing the empirical likelihood and unfortunately, requires stringent assumptions on the dictionary, the so-called, compatibility conditions. Though compatibility conditions are hard to satisfy, it is well known that this can be accomplished by using random dictionaries. In the present paper, we show how one can apply random dictionaries to the solution of ill-posed linear inverse problems. We put a theoretical foundation under the suggested methodology and study its performance via simulations and real-data example.
OCGAN: One-Class Novelty Detection Using GANs With Constrained Latent Representations

We present a novel model called OCGAN for the classical problem of one-class novelty detection, where, given a set of examples from a particular class, the goal is to determine if a query example is from the same class. Our solution is based on learning latent representations of in-class examples using a de-noising auto-encoder network. The key contribution of our work is our proposal to explicitly constrain the latent space to exclusively represent the given class. In order to accomplish this goal, firstly, we force the latent space to have bounded support by introducing a tanh activation in the encoder's output layer. Secondly, using a discriminator in the latent space that is trained adversarially, we ensure that encoded representations of in-class examples resemble uniform random samples drawn from the same bounded space. Thirdly, using a second adversarial discriminator in the input space, we ensure all randomly drawn latent samples generate examples that look real. Finally, we introduce a gradient-descent based sampling technique that explores points in the latent space that generate potential out-of-class examples, which are fed back to the network to further train it to generate in-class examples from those points. The effectiveness of the proposed method is measured across four publicly available datasets using two one-class novelty detection protocols where we achieve state-of-the-art results.
Pricing in non-convex markets with quadratic deliverability costs

Abstract This article studies the problem of obtaining equilibrium clearing prices for markets with non-convexities when it is relevant to account for convex quadratic deliverability costs and constraints. In a general market, such a situation arises when quadratic commodity or transactions costs are relevant. In the particular case of electricity markets, there is a mix of resources including dispatchable and renewable energy sources, leading to the presence of integer variables and quadratic costs reflecting ramping needs. To illustrate our results, we compute and analyze the equilibrium clearing prices of the Scarf’s classical market problem with the addition of ramping costs.