cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis of β-Alkoxy Ketones and α‘-Functionalized β-Alkoxy Ketones Utilizing Benzotriazole-Stabilized Acyl Anion Synthons

1-(α-Alkoxyalkyl)benzotriazoles 1a−d add to phenyl vinyl ether to form key intermediates 4a−d, which readily undergo lithiation and subsequent trapping by a variety of electrophiles to give the expected substituted derivatives 7a−d, 9a−c, 11, 13, 15, and 18 in high yields. Subsequent hydrolysis of these compounds provides a novel high-yield acyl anion synthon approach for the synthesis of β-alkoxy ketones 8 or α‘-functionalized β-alkoxy ketones 10, 12, 14, 16, and 19 by short procedures from readily available starting materials.
Synthesis of the dichlorobisoxazole-indole portion of the antitumor agent diazonamide by a putative biogenetic strategy

Abstract Chlorination of the bis-oxazole-indole 16 using N -chlorosuccinimide gave the dichloride 13 (86%) and the trichloride 12 (5%) thus completing the synthesis of the CDEF rings of diazonamide.
Design and synthesis of a tridentate ligand for asymmetric bifunctional catalysis

Abstract Covalent attachment of a quinine moiety to a Schiff base ligand through an ester linkage generates a novel tridentate ligand that gives a new Lewis acid–Lewis base (LA–LB ∗ ) bifunctional catalyst having a mixture of the LA configurations. The LB ∗ -dependent asymmetric bifunctional catalysis was demonstrated using the addition of diethylzinc to 2-methoxybenzaldehyde as a test reaction and the substrate scope of the new catalyst was illustrated using aromatic aldehydes.
Preparation of 2‐, 4‐, 5‐, and 6‐aminonicotinic acid tert‐butyl esters

Procedures are reported to prepare the tert-butyl esters of 2-aminonicotinic acid, 4-aminonicotinic acid, 5-aminonicotinic acid, and 6-aminonicotinic acid from 2-chloronicotinic acid, 4-chloronicotinic acid, 5-bromonicotinic acid, and 6-chloronicotinic acid, respectively, without need for purification of intermediates. J. Heterocyclic Chem., (2012).
Polyselenide chemistry of indium and thallium in dimethylformamide, acetonitrile, and water. Syntheses, structures, and properties of the new complexes [In2(Se4)4(Se5)]4-, [In2Se2(Se4)2]2-, [In3Se3(Se4)3]3-, and [Tl3Se3(Se4)3]3-

The reaction of InCl 3 with Na 2 Se 5 in dimethylformamide (DMF) in the presence of Ph 4 PCl gave (Ph 4 P) 4 [In 2 (Se 4 ) 4 (Se 5 )] in 75% yield. Under the same conditions, InCl 3 reacted with Na 2 Se 5 in the presence of Pr 4 NBr or Et 4 NBr and afforded (Pr 4 N) 4 [In 2 (Se 4 ) 4 (Se 5 )] in 65% yield and (Et 4 N 4 )[In 2 (Se 4 ) 4 (Se 5 )] in 72% yield respectively.
Chemistry of anti-o,o‘-Dibenzene

A new and efficient preparation of anti-o,o‘-dibenzene 1 has been achieved in three steps from cis-3,5-cyclohexadiene-1,2-diol 25. Utilizing a method for deoxygenation of 1,2-diols developed in our...
Enantioselective Diene Cyclization/Hydrosilylation Catalyzed by Optically Active Palladium Bisoxazoline and Pyridine−Oxazoline Complexes

A 1:1 mixture of (N−N)Pd(Me)Cl [N−N = (S,S)-4,4‘-dibenzyl-4,5,4‘,5‘-tetrahydro-2,2‘-bisoxazoline] (S,S-4a) and NaBAr4 [Ar = 3,5-C6H3(CF3)2] (5 mol %) catalyzed the asymmetric cyclization/hydrosilylation of dimethyl diallylmalonate (2) and triethylsilane at −30 °C for 48 h to form an 8.1:1 mixture of the silylated carbocycle (S,S)-trans-1,1-dicarbomethoxy-4-methyl-3-[(triethylsilyl)methyl]cyclopentane (S,S-3) (95% de, 72% ee) and dimethyl 3,4-dimethylcyclopentane-1,1-dicarboxylate (S,S-6) in 64% combined yield. In comparison, a 1:1 mixture of the palladium pyridine−oxazoline complex (N−N)Pd(Me)Cl [N−N = (R)-(+)-4-isopropyl-2-(2-pyridinyl)-2-oxazoline] (R-5b) and NaBAr4 (5 mol %) catalyzed the asymmetric cyclization/hydrosilylation of 2 and triethylsilane at −32 °C for 24 h to form carbocycle S,S-3 in 82% yield (>95% de, 87% ee) as the exclusive product. Asymmetric diene cyclization catalyzed by complex R-5b was compatible with a range of functional groups and produced carbocycles with up to 91% ee. The pro...
A direct copper-catalyzed route to pyrrolo-fused heterocycles from boronic acids

Abstract A convenient route to prepare azaindoles and related pyrrolo-fused heterocycles from boronic acids, DBAD (di-tert-butyl-diazodicarboxylate) and enolizable aldehydes and ketones is presented. The reaction proceeds via a one-pot four-step cascade sequence with key steps involving a copper-catalyzed boronic acid coupling to DBAD and a Fischer indolization providing access to a variety of pharmaceutically interesting heterocycles including pyrrolo-pyridines, -pyrimidines, -quinolines, and -isoquinolines from readily available aza–aryl boronic acid precursors.
A Multiscale Scan Statistic for Adaptive Submatrix Localization

We consider the problem of localizing a submatrix with larger-than-usual entry values inside a data matrix, without the prior knowledge of the submatrix size. We establish an optimization framework based on a multiscale scan statistic, and develop algorithms in order to approach the optimizer. We also show that our estimator only requires a signal strength of the same order as the minimax estimator with oracle knowledge of the submatrix size, to exactly recover the anomaly with high probability. We perform some simulations that show that our estimator has superior performance compared to other estimators which do not require prior submatrix knowledge, while being comparatively faster to compute.
Variational autoencoder: An unsupervised model for encoding and decoding fMRI activity in visual cortex

Goal-driven and feedforward-only convolutional neural networks (CNN) have been shown to be able to predict and decode cortical responses to natural images or videos. Here, we explored an alternative deep neural network, variational auto-encoder (VAE), as a computational model of the visual cortex. We trained a VAE with a five-layer encoder and a five-layer decoder to learn visual representations from a diverse set of unlabeled images. Using the trained VAE, we predicted and decoded cortical activity observed with functional magnetic resonance imaging (fMRI) from three human subjects passively watching natural videos. Compared to CNN, VAE could predict the video-evoked cortical responses with comparable accuracy in early visual areas, but relatively lower accuracy in higher-order visual areas. The distinction between CNN and VAE in terms of encoding performance was primarily attributed to their different learning objectives, rather than their different model architecture or number of parameters. Despite lower encoding accuracies, VAE offered a more convenient strategy for decoding the fMRI activity to reconstruct the video input, by first converting the fMRI activity to the VAE's latent variables, and then converting the latent variables to the reconstructed video frames through the VAE's decoder. This strategy was more advantageous than alternative decoding methods, e.g. partial least squares regression, for being able to reconstruct both the spatial structure and color of the visual input. Such findings highlight VAE as an unsupervised model for learning visual representation, as well as its potential and limitations for explaining cortical responses and reconstructing naturalistic and diverse visual experiences.
The Olefin Metathesis Approach to Epothilone A and Its Analogues

The olefin metathesis approach to epothilone A (1) and several analogues (39−41, 42−44, 51−57, 58−60, 64−65, and 67−69) is described. Key building blocks 6−8 were constructed in optically active form and were coupled and elaborated to olefin metathesis precursor 4 via an aldol reaction and an esterification coupling. Olefin metathesis of compound 4, under the catalytic influence of RuCl2(CHPh)(PCy3)2, furnished cis- and trans-cyclic olefins 3 and 48. Epoxidation of 49 gave epothilone A (1) and several analogues, whereas epoxidation of 50 resulted in additional epothilones. Similar elaboration of isomeric as well as simpler intermediates resulted in yet another series of epothilone analogues and model systems.
Measures of decoherence

Methods for quantifying environmentally induced decoherence in quantum systems are investigated. We formulate criteria for measuring the degree of decoherence and consider several representative examples, including a spin interacting with the modes of a bosonic, e.g., phonon, bath. We formulate an approach based on the operator norm measuring the deviation of the actual density matrix from the ideal one which would describe the system without environmental interactions.
B-Chlorodialkylboranes for the enolboration of 3,3,3-trifluoropropionates

The increased acidity of the α-protons of 3,3,3-trifluoropropionates was exploited to achieve the enolboration of these esters using dialkylchloroboranes.
CHIRAL PERTURBATION THEORY, NON-LEPTONIC KAON DECAYS, AND THE LATTICE

In this talk, I rst motivate the use of Chiral Perturbation Theory in the context of Lattice QCD. In particular, I explain how partially quenched QCD, which has, in general, unequal valence- and sea-quark masses, can be used to obtain real-world (i.e. unquenched) results for low-energy constants. In the second part, I review how Chiral Perturbation Theory may be used to overcome theoretical diculties which aict the computation of non-leptonic kaon decay rates from Lattice QCD. I argue that it should be possible to determine at least the O(p 2 )w eak low-energy constants reliably from numerical computations of the K ! and K ! vacuum matrix elements of the corresponding weak operators. Ideally, Lattice QCD should lead to the unambiguous, rst-principle determination of hadronic quantities. However, it does not work that way in practice, basically because of limits on available computational power. Because of these limits, approximations are needed which lead to systematic errors, and we need a theoretical understanding of these in order to obtain estimates of hadronic quantities with known and controlled errors. This talk addresses some of the limitations of Lattice QCD with respect to the physics of Goldstone Bosons (GBs), and explains how Chiral Perturbation Theory (ChPT) can be used to extract physical quantities from the often unphysical results of lattice computations. The basic idea is that ChPT parametrizes QCD correlation functions involving GBs in terms of a number of parameters, the low-energy constants (LECs). To a given order in the chiral expansion, physical quantities are determined completely in terms of a nite number of LECs, and these LECs can then be obtained from (possibly other) correlation functions at often unphysical choices of masses and momenta which are more easily accessible to numerical computation. Such a program only works if the chiral expansion converges in the regions of interest (both physical and on the lattice), but this can in principle be checked by considering successive terms in the chiral expansion, once the LECs have been determined from ts to lattice results. Obviously, for such checks at least two orders in the chiral expansion need to be considered, and one-loop ChPT is essential.
Synthesis and stability of 2-(1,1-difluoroalkyl) thiophenes and related 1,1-difluoroalkyl benzenes: fluorinated building blocks for liquid crystal synthesis

Abstract The synthesis of a series of 2-(1,1-difluoroalkyl) thiophenes, including some biphenylthienyl liquid crystalline materials, was examined using a variety of fluorination approaches. For comparison purposes, a series of 1,1-difluoroalkyl benzene analogs were also prepared. The direct fluorodeoxygenation of alkyl thienyl ketones and alkyl phenyl ketones using various aminofluorosulfuranes proceeded in only moderate to poor yields. In contrast, fluorodesulfurization of the corresponding 1,3-dithiolanes using NOBF4/PPHF cleanly afforded the desired 2-(1,1-difluoroalkyl) thiophenes (and analogous 1,1-difluoroalkyl benzenes) in high yields. Fluorodesulfurization of 2-alkyl-2-thienyl-1,3-dithiolanes using NBS (or DBH)/PPHF was complicated by competing ring and/or side chain bromination pathways. These problems were avoided when using NIS/PPHF. Although the various 1,1-difluoroalkyl arene products were sensitive to hydrolytic decomposition on prolonged exposure to silica, the purified products proved quite stable and were well suited for use as building blocks for liquid crystal synthesis.
PRESSURE-INDUCED PHASE TRANSITION IN PRALO3

PrAlO3 is shown to undergo a rhombohedral (R3c) to orthorhombic (Imma) phase transition upon application of pressures of up to 9.1 GPa. The structures in both phases have been refined from high-re...
Kinetics of the Reaction Al + SF6 in the Temperature Range 499−813 K

Rate constants as a function of temperature for the reaction Al + SF6 have been measured under pseudo-first-order conditions. Laser-induced fluorescence was used to monitor the relative concentrations of either the reactant Al or the primary product AlF. The measured rate constants are described by the expression k(T) = 6.8 (± 2.2) × 10-10 exp(−(4780 ± 200 K)/T) cm3 molecule-1 s-1 over the range 499−813 K. Ab initio and density functional calculations at the MP2(FC) and BH&HLYP levels have been used to model the potential energy surface for this reaction. Calculated rate constants are in good agreement with experimental observations.
Formation of Naphthoquinone Oxo-Pyridinium Inner Salts

Abstract When 2-chloro-3-(substitued phenoxy)naphthazarine (1) was treated with pyridine or substituted pyridine at elevated temperature, an unexpected reaction took place. The product was identified as 5,8-Dihydroxy-1,4-dioxo-3-(substituted pyridinium)-2-naphthoxide (3, 4). A reaction mechanism for the formation of this product was postulated.
Complete Genome Sequence of the Wolbachia wAlbB Endosymbiont of Aedes albopictus.

Wolbachia, an alpha-proteobacterium closely related to Rickettsia, is a maternally transmitted, intracellular symbiont of arthropods and nematodes. Aedes albopictus mosquitoes are naturally infected with Wolbachia strains wAlbA and wAlbB. Cell line Aa23 established from Ae. albopictus embryos retains only wAlbB and is a key model to study host-endosymbiont interactions. We have assembled the complete circular genome of wAlbB from the Aa23 cell line using long-read PacBio sequencing at 500× median coverage. The assembled circular chromosome is 1.48 megabases in size, an increase of more than 300 kb over the published draft wAlbB genome. The annotation of the genome identified 1,205 protein coding genes, 34 tRNA, 3 rRNA, 1 tmRNA, and 3 other ncRNA loci. The long reads enabled sequencing over complex repeat regions which are difficult to resolve with short-read sequencing. Thirteen percent of the genome comprised insertion sequence elements distributed throughout the genome, some of which cause pseudogenization. Prophage WO genes encoding some essential components of phage particle assembly are missing, while the remainder are found in five prophage regions/WO-like islands or scattered around the genome. Orthology analysis identified a core proteome of 535 orthogroups across all completed Wolbachia genomes. The majority of proteins could be annotated using Pfam and eggNOG analyses, including ankyrins and components of the Type IV secretion system. KEGG analysis revealed the absence of five genes in wAlbB which are present in other Wolbachia. The availability of a complete circular chromosome from wAlbB will enable further biochemical, molecular, and genetic analyses on this strain and related Wolbachia.
Tight Turns of Outer Membrane Proteins: An Analysis of Sequence, Structure, and Hydrogen Bonding

As a structural class, tight turns can control molecular recognition, enzymatic activity, and nucleation of folding. They have been extensively characterized in soluble proteins but have not been characterized in outer membrane proteins (OMPs), where they also support critical functions. We clustered the 4 to 6 residue tight turns of 110 OMPs to characterize the phi/psi angles, sequence, and hydrogen bonding of these structures. We find significant differences between reports of soluble protein tight turns and OMP tight turns. Since OMP strands are less twisted than soluble strands, they favor different turn structures types. Moreover, the membrane localization of OMPs yields different sequence hallmarks for their tight turns relative to soluble protein turns. We also characterize the differences in phi/psi angles, sequence, and hydrogen bonding between OMP extracellular loops and OMP periplasmic turns. As previously noted, the extracellular loops tend to be much longer than the periplasmic turns. We find that this difference in length is due to the broader distribution of lengths of the extracellular loops not a large difference in the median length. Extracellular loops also tend to have more charged residues as predicted by the charge-out rule. Finally, in all OMP tight turns, hydrogen bonding between the side chain and backbone 2 to 4 residues away from that side chain plays an important role. These bonds preferentially use an Asp, Asn, Ser, or Thr residue in a beta or pro phi/psi conformation. We anticipate that this study will be applicable to future design and structure prediction of OMPs.
Optoelectronic Properties and Memories Based on Organic Single-Crystal Thin Films

Organic and organometallic materials are promising candidates for molecular electronic devices. In addition to the currently commercialized liquid crystal displays, there are light-emitting diodes and other displays, transistors, memories, and photoelectric devices on the horizon.1-10 Interest in organic materials for these applications arises from the huge number of structures available in this class of compounds and the possibility of tuning electrical and optical properties over a wide region by purposeful design. Encouragement for these views comes from the fact that conductivities in organic materials (crystals, polymers) vary by over more than 20 orders of magnitude (from TTF-TCNQ to Teflon) and that complex biological systems utilize organics. Before such devices can be realized, however, a better understanding of the structural factors that control the electrical and optical properties of organic solids is needed. These include studies of the nature of charge carriers and the factors that control their mobility. Especially important are the effects of traps (crystal defects, grain boundaries, impurities) on the electrical properties. The nature of contacts to the organic devices and the factors that control charge transfer at the metal contact/organic crystal interface are also of importance in device fabrication. In this Account we deal with single-crystal thin films and their electric and spectroscopic properties and discuss their potential application in memory devices for reversible, high-density optoelectronic data storage.
Mechanical and tactile incompatibilities cause reproductive isolation between two young damselfly species

External male reproductive structures have received considerable attention as a cause of reproductive isolation (RI), because the morphology of these structures often evolves rapidly between populations. This rapid evolution presents the potential for mechanical incompatibilities with heterospecific female structures during mating and could thus prevent interbreeding between nascent species. Although such mechanical incompatibilities have received little empirical support as a common cause of RI, the potential for mismatch of reproductive structures to cause RI due to incompatible species-specific tactile cues has not been tested. We tested the importance of mechanical and tactile incompatibilities in RI between Enallagma anna and E. carunculatum, two damselfly species that diverged within the past ∼250,000 years and currently hybridize in a sympatric region. We quantified 19 prezygotic and postzygotic RI barriers using both naturally occurring and lab-reared damselflies. We found incomplete mechanical isolation between the two pure species and between hybrid males and pure species females. Interestingly, in species pairs for which mechanical isolation was incomplete, females showed greater resistance and refusal to mate with hybrid or heterospecific males compared to conspecific males. This observation suggests that tactile incompatibilities involving male reproductive structures can influence female mating decisions and form a strong barrier to gene flow in early stages of speciation. This article is protected by copyright. All rights reserved
Indel-correcting DNA barcodes for high-throughput sequencing.

Many large-scale, high-throughput experiments use DNA barcodes, short DNA sequences prepended to DNA libraries, for identification of individuals in pooled biomolecule populations. However, DNA synthesis and sequencing errors confound the correct interpretation of observed barcodes and can lead to significant data loss or spurious results. Widely used error-correcting codes borrowed from computer science (e.g., Hamming, Levenshtein codes) do not properly account for insertions and deletions (indels) in DNA barcodes, even though deletions are the most common type of synthesis error. Here, we present and experimentally validate filled/truncated right end edit (FREE) barcodes, which correct substitution, insertion, and deletion errors, even when these errors alter the barcode length. FREE barcodes are designed with experimental considerations in mind, including balanced guanine-cytosine (GC) content, minimal homopolymer runs, and reduced internal hairpin propensity. We generate and include lists of barcodes with different lengths and error correction levels that may be useful in diverse high-throughput applications, including >106 single-error–correcting 16-mers that strike a balance between decoding accuracy, barcode length, and library size. Moreover, concatenating two or more FREE codes into a single barcode increases the available barcode space combinatorially, generating lists with >1015 error-correcting barcodes. The included software for creating barcode libraries and decoding sequenced barcodes is efficient and designed to be user-friendly for the general biology community.
Cyanthiwigin AC and AD, two novel diterpene skeletons from the Jamaican sponge Myrmekioderma styx.

Three novel diterpenes, called cyanthiwigins AB (1), AC (2), and AD (3), were isolated from the Jamaican sponge Myrmekioderma styx. Their structures were elucidated by means of 1D and 2D NMR spectroscopic methods. Cyanthiwigin AC (2) and AD (3) represent novel diterpene-type skeletons.
Nanosized AlPO4-5 Molecular Sieves and Ultrathin Films Prepared by Microwave Synthesis

Nanosized AlPO{sub 4}-5 molecular sieves and submicron AlPO{sub 4}-5 films were synthesized by microwave treatment of aluminophosphate precursors. The effects of the chemical composition of the initial solution and the conditions of microwave treatment of aluminophosphate precursors on the synthesis of nanosized AlPO{sub 4}-5 molecular sieves were investigated. The syntheses were performed under hydrothermal conditions in a microwave oven at temperatures ranging from 90 to 160 C, using various concentrations of H{sub 2}O and organic template and varying aging times. The resulting bulk products were analyzed using X-ray diffraction, scanning electron microscopy, thermogravimetry, dynamic light scattering, and nitrogen sorption. Optimal conditions for the preparation of nanosized molecular sieve crystals were found. Thin films of AlPO{sub 4}-5 on acoustic wave devices were also prepared, composed of a molecular coupling layer, AlPO{sub 4}-5 seed crystals, and a homogeneous porous film formed by microwave treatment of an aluminophosphate precursor. The initial mixture composition and microwave conditions affect the thickness and the orientation of the zeolite crystals in the films. Sorption isotherms for n-hexane and cyclohexane in these AlPO{sub 4}5 films are reported.
Nucleophilic fluorination of amino alcohols and diols using Deoxofluor

Abstract Various fluorinated chiral compounds were synthesized using bis(2-methoxyethyl)aminosulfur trifluoride (Deoxofluor) as a nucleophilic fluorinating reagent. Reactions of Deoxofluor (1) with amino alcohols (2a–d) and diols (2e–g) in methylene chloride at room temperature led to the formation of the corresponding fluoro derivatives (3a–g) in good yields.
Synthesis of (-)-epibatidine.

The synthesis of (−)-epibatidine has been accomplished utilizing a highly exo-selective asymmetric hetero Diels−Alder reaction. The key steps employed to transform the resulting bicycle into the na...
N-Heterocyclic Carbene Catalyzed Asymmetric Hydration: Direct Synthesis of α-Protio and α-Deuterio α-Chloro and α-Fluoro Carboxylic Acids

Asymmetric hydration of α,α-dichloro aldehydes and α-halo enals via a NHC-catalyzed redox process to yield enantioenriched α-chloro and α-fluoro carboxylic acids is described herein. The developed reaction allows for installation of an α-deuterium to give rise to enantioenriched α-deutero α-halo acids using D2O as the deuteron source.
Outcomes research shifting the dominant research paradigm in physical therapy

This article discusses outcomes research in physical therapy and places its conceptual roots within the work on quality-of-care assessment. An argument is advanced that the outcomes research movement in medicine has stimulated clinical researchers in physical therapy to address disability outcomes in addition to traditional impairment outcomes. If physical therapy clinical research moves beyond this broadening of clinical outcomes to investigate explicitly the hypothesized relationship between impairment and disability, outcomes research will have stimulated a shift in the dominant research paradigm in the profession. The development and testing of theory regarding the pathogenesis of disability will be needed to guide the direction of this type of physical therapy research. Such a shift in the dominant research paradigm in physical therapy could produce dramatic findings that have direct impact on clinical practice.
A simply exponential upper bound on the maximum number of stable matchings

Stable matching is a classical combinatorial problem that has been the subject of intense theoretical and empirical study since its introduction in 1962 in a seminal paper by Gale and Shapley. In this paper, we provide a new upper bound on f(n), the maximum number of stable matchings that a stable matching instance with n men and n women can have. It has been a long-standing open problem to understand the asymptotic behavior of f(n) as n→∞, first posed by Donald Knuth in the 1970s. Until now the best lower bound was approximately 2.28n, and the best upper bound was 2nlogn− O(n). In this paper, we show that for all n, f(n) ≤ cn for some universal constant c. This matches the lower bound up to the base of the exponent. Our proof is based on a reduction to counting the number of downsets of a family of posets that we call “mixing”. The latter might be of independent interest.
Cartan subalgebras for quantum symmetric pair coideals

There is renewed interest in the coideal subalgebras used to form quantum symmetric pairs because of recent discoveries showing that they play a fundamental role in the representation theory of quantized enveloping algebras. However, there is still no general theory of finite-dimensional modules for these coideals. In this paper, we establish an important step in this direction: we show that every quantum symmetric pair coideal subalgebra admits a quantum Cartan subalgebra which is a polynomial ring that specializes to its classical counterpart. The construction builds on Kostant and Sugiura's classification of Cartan subalgebras for real semisimple Lie algebras via strongly orthogonal systems of positive roots. We show that these quantum Cartan subalgebras act semisimply on finite-dimensional unitary modules and identify particularly nice generators of the quantum Cartan subalgebra for a family of examples.
Employing Coded Relay in multi-hop wireless networks

In this paper, we propose Coded Relay (Crelay) for multi-hop wireless networks. Crelay exploits both the partial packets and the overhearing capabilities of wireless nodes, and uses an error correction code in packet forwarding. When a node overhears a partial packet from an upstream node, it estimates the number of errors in the packet and informs the upstream node. The upstream node calculates the number of parity bytes required to correct the errors and can usually send only a small amount parity bytes instead of sending the complete packet, hence improving the network efficiency. We propose a novel protocol for packet forwarding with partial packets and overhearing, which forwards individual packets and will work seamlessly with upper layers. We also propose a practical algorithm for finding the packet forwarding path. We implement Crelay within the Click modular router and our experiments show that it can significantly improve the performance of wireless networks.
Nearly optimal sample size in hypothesis testing for high-dimensional regression

We consider the problem of fitting the parameters of a high-dimensional linear regression model. In the regime where the number of parameters p is comparable to or exceeds the sample size n, a successful approach uses an l1-penalized least squares estimator, known as Lasso. Unfortunately, unlike for linear estimators (e.g. ordinary least squares), no well-established method exists to compute confidence intervals or p-values on the basis of the Lasso estimator. Very recently, a line of work [8], [7], [13] has addressed this problem by constructing a debiased version of the Lasso estimator. We propose a special debiasing method that is well suited for random designs with sparse inverse covariance. Our approach improves over the state of the art in that it yields nearly optimal average testing power if sample size n asymptotically dominates s0(logp)2, with s0 being the sparsity level (number of non-zero coefficients). Earlier work achieved similar performances only for much larger sample size, namely it requires n to asymptotically dominates (s0 log p)2. We evaluate our method on synthetic data, and compare it with earlier proposals.
Subsampling in Smoothed Range Spaces

We consider smoothed versions of geometric range spaces, so an element of the ground set e.g. a point can be contained in a range with a non-binary value in [0,i¾?1]. Similar notions have been considered for kernels; we extend them to more general types of ranges. We then consider approximations of these range spaces through $$\varepsilon $$-nets and $$\varepsilon $$-samples aka $$\varepsilon $$-approximations. We characterize when size bounds for $$\varepsilon $$-samples on kernels can be extended to these more general smoothed range spaces. We also describe new generalizations for $$\varepsilon $$-nets to these range spaces and show when results from binary range spaces can carry over to these smoothed ones.
Spectropolarimetry of the WR + O Binary WR42

We present new spectropolarimetric data for WR 42 collected over 6 months at the 11-m Southern African Large Telescope (SALT) using the Robert Stobie Spectrograph.
Structured Analysis Dictionary Learning for Image Classification

We propose a computationally efficient and high-performance classification algorithm by incorporating class structural information in analysis dictionary learning. To achieve more consistent classification, we associate a class characteristic structure of independent subspaces and impose it on the classification error constrained analysis dictionary learning. Experiments demonstrate that our method achieves a comparable or better performance than the state-of-the-art algorithms in a variety of visual classification tasks. In addition, our method greatly reduces the training and testing computational complexity.
What Game Are We Playing? End-to-end Learning in Normal and Extensive Form Games

Although recent work in AI has made great progress in solving large, zero-sum, extensive-form games, the underlying assumption in most past work is that the parameters of the game itself are known to the agents. This paper deals with the relatively under-explored but equally important "inverse" setting, where the parameters of the underlying game are not known to all agents, but must be learned through observations. We propose a differentiable, end-to-end learning framework for addressing this task. In particular, we consider a regularized version of the game, equivalent to a particular form of quantal response equilibrium, and develop 1) a primal-dual Newton method for finding such equilibrium points in both normal and extensive form games; and 2) a backpropagation method that lets us analytically compute gradients of all relevant game parameters through the solution itself. This ultimately lets us learn the game by training in an end-to-end fashion, effectively by integrating a "differentiable game solver" into the loop of larger deep network architectures. We demonstrate the effectiveness of the learning method in several settings including poker and security game tasks.
Nonexpanding attractors: Conjugacy to algebraic models and classification in 3-manifolds

We prove a result motivated by Williams's classification of expanding attractors and the Franks--Newhouse Theorem on codimension-$1$ Anosov diffeomorphisms: If $\Lambda$ is a topologically mixing hyperbolic attractor such that $\dim\E^u$| $\Lambda$ = 1, then either $\Lambda$ is expanding or is homeomorphic to a compact abelian group (a toral solenoid ). In the latter case, $f$| $\Lambda$ is conjugate to a group automorphism. As a corollary, we obtain a classification of all $2$-dimensional basic sets in $3$-manifolds. Furthermore, we classify all topologically mixing hyperbolic attractors in $3$-manifolds in terms of the classically studied examples, answering a question of Bonatti in [1].
Hierarchical CVAE for Fine-Grained Hate Speech Classification

Existing work on automated hate speech detection typically focuses on binary classification or on differentiating among a small set of categories. In this paper, we propose a novel method on a fine-grained hate speech classification task, which focuses on differentiating among 40 hate groups of 13 different hate group categories. We first explore the Conditional Variational Autoencoder (CVAE) as a discriminative model and then extend it to a hierarchical architecture to utilize the additional hate category information for more accurate prediction. Experimentally, we show that incorporating the hate category information for training can significantly improve the classification performance and our proposed model outperforms commonly-used discriminative models.
Power systems data fusion based on belief propagation

The increasing complexity of the power grid, due to higher penetration of distributed resources and growing availability of interconnected, distributed metering devices requires novel tools for providing a unified, consistent view of the system. A computational framework for power systems data fusion, based on probabilistic graphical models, capable of combining heterogeneous data sources with classical state estimation nodes and other customised computational nodes, is proposed. The framework allows flexible extension of the notion of grid state beyond the view of flows and injection in bus-branch models, and an efficient, naturally distributed inference algorithm can be derived. An application of the data fusion model to the quantification of distributed solar energy is proposed through numerical examples based on semi-synthetic simulations of the standard IEEE 14-bus test case.
Distances and Intersections of Curves

We obtain a coarse relationship between geometric intersection numbers of curves and the sum of their subsurface projection distances with explicit quasi-constants. By using this relationship, we give applications in the studies of the curve graphs and the mapping class groups.
Conformal Grushin spaces

We introduce a class of metrics on $\mathbb{R}^n$ generalizing the classical Grushin plane. These are length metrics defined by the line element $ds = d_E(\cdot,Y)^{-\beta}ds_E$ for a closed nonempty subset $Y \subset \mathbb{R}^n$ and $\beta \in [0,1)$. We prove that, assuming a Holder condition on the metric, these spaces are quasisymmetrically equivalent to $\mathbb{R}^n$ and can be embedded in some larger Euclidean space under a bi-Lipschitz map. Our main tool is an embedding characterization due to Seo, which we strengthen by removing the hypothesis of uniform perfectness. In the two-dimensional case, we give another proof of bi-Lipschitz embeddability based on growth bounds on sectional curvature.
Randomness of character sums modulo m

Abstract Using a probabilistic model, based on random walks on the additive group Z / m Z , we prove that the values of certain real character sums are uniformly distributed in residue classes modulo m.
Optimal Nested Test Plan for Combinatorial Quantitative Group Testing

We consider the quantitative group testing problem where the objective is to identify defective items in a given population based on results of tests performed on subsets of the population. Under the quantitative group testing model, the result of each test reveals the number of defective items in the tested group. The minimum number of tests achievable by nested test plans was established by Aigner and Schughart in 1985 within a minimax framework. The optimal nested test plan offering this performance, however, was not obtained. In this paper, we establish the optimal nested test plan in a closed form. This optimal nested test plan is also order optimal among all test plans as the population size approaches infinity. Using heavy-hitter detection as a case study, we show via simulation examples orders of magnitude improvement of the group testing approach over two prevailing sampling-based approaches in detection accuracy and counter consumption. Other applications include anomaly detection and wideband spectrum sensing in cognitive radio systems.
Zooming in on NYC taxi data with portal

In this paper we develop a methodology for analyzing transportation data at different levels of temporal and geographic granularity, and apply our methodology to the TLC Trip Record Dataset, made publicly available by the NYC Taxi & Limousine Commission. This data is naturally represented by a set of trajectories, annotated with time and with additional information such as passenger count and cost. We analyze TLC data to identify hotspots, which point to lack of convenient public transportation options, and popular routes, which motivate ride-sharing solutions or addition of a bus route. Our methodology is based on using a system called Portal, which implements efficient representations and principled analysis methods for evolving graphs. Portal is implemented on top of Apache Spark, a popular distributed data processing system, is inter-operable with other Spark libraries like SparkSQL, and supports sophisticated kinds of analysis of evolving graphs efficiently. Portal is currently under development in the Data, Responsibly Lab at Drexel. We plan to release Portal in the open source in Fall 2017.
On the cardinality of Hausdorff spaces and H-closed spaces

Abstract We introduce the cardinal invariant a L ′ ( X ) and show that | X | ≤ 2 a L ′ ( X ) χ ( X ) for any Hausdorff space X (a corollary of Theorem 4.4 ). This invariant has the properties a) a L ′ ( X ) = ℵ 0 if X is H-closed, and b) a L ( X ) ≤ a L ′ ( X ) ≤ a L c ( X ) . Theorem 4.4 then gives a new improvement of the well-known Hausdorff bound 2 L ( X ) χ ( X ) from which it follows that | X | ≤ 2 ψ c ( X ) if X is H-closed (Dow/Porter [5] ). The invariant a L ′ ( X ) is constructed using convergent open ultrafilters and an operator c ˆ : P ( X ) → P ( X ) with the property c l A ⊆ c ˆ ( A ) ⊆ c l θ ( A ) for all A ⊆ X . As a comparison with this open ultrafilter approach, in § 3 we additionally give a κ-filter variation of Hodel's proof [8] of the Dow–Porter result. Finally, for an infinite cardinal κ, in § 5 we introduce κwH-closed spaces, κ H ′ -closed spaces, and κ H ″ -closed spaces. The first two notions generalize the H-closed property. Key results in this connection are that a) if κ is an infinite cardinal and X a κwH-closed space with a dense set of isolated points such that χ ( X ) ≤ κ , then | X | ≤ 2 κ , and b) if X is κ H ′ -closed or κ H ″ -closed then a L ′ ( X ) ≤ κ . This latter result relates these notions to the invariant a L ′ ( X ) and the operator c ˆ .
The Persistence of Apparent Non-Magnetostatic Equilibrium in NOAA 11035

NOAA 11035 was a highly sheared active region that appeared in December 2009 early in the new activity cycle. The leading polarity sunspot developed a highly unusual feature in its penumbra, an opposite polarity pore with a strong magnetic field in excess of 3500 G along one edge, which persisted for several days during the evolution of the region. This region was well observed by both space- and ground-based observatories, including Hinode, FIRS, TRACE, and SOHO. These observations, which span wavelength and atmospheric regimes, provide a complete picture of this unusual feature which may constitute a force-free magnetic field in the photosphere which is produced by the reconnection of magnetic loops low in the solar atmosphere.
Irreducible Representations of the Quantum Weyl Algebra at Roots of Unity Given by Matrices

To describe the representation theory of the quantum Weyl algebra at an lth primitive root γ of unity, Boyette, Leyk, Plunkett, Sipe, and Talley found all nonsingular irreducible matrix solutions to the equation yx − γxy = 1, assuming yx ≠ xy. In this note, we complete their result by finding and classifying, up to equivalence, all irreducible matrix solutions (X, Y), where X is singular.
Quantitative logarithmic equidistribution of the crucial measures

Let K be an algebraically closed field of characteristic 0 that is complete with respect to a non-Archimedean absolute value, and let $$\phi \in K(z)$$ with $$\deg (\phi )\ge 2$$ . Recently, Rumely introduced a family of discrete probability measures $$\{\nu _{\phi ^n}\}$$ on the Berkovich line $$\mathbf{P }^1_{\text {K}}$$ over K which carry information about the reduction of conjugates of $$\phi $$ . In a previous article, the author showed that the measures $$\nu _{\phi ^n}$$ converge weakly to the canonical measure $$\mu _\phi $$ . In this article, we extend this result to allow test functions which may have logarithmic singularities at the boundary of $$\mathbf{P }^1_{\text {K}}$$ . These integrands play a key role in potential theory, and we apply our main results to show the potential functions attached to $$\nu _{\phi ^n}$$ converge to the potential function attached to $$\mu _\phi $$ , as well as an approximation result for the Lyapunov exponent of $$\phi $$ .
A proof of the peak polynomial positivity conjecture

Abstract We say that a permutation π = π 1 π 2 ⋯ π n ∈ S n has a peak at index i if π i − 1 π i > π i + 1 . Let P ( π ) denote the set of indices where π has a peak. Given a set S of positive integers, we define P ( S ; n ) = { π ∈ S n : P ( π ) = S } . In 2013 Billey, Burdzy, and Sagan showed that for subsets of positive integers S and sufficiently large n, | P ( S ; n ) | = p S ( n ) 2 n − | S | − 1 where p S ( x ) is a polynomial depending on S. They proved this by establishing a recursive formula for p S ( x ) involving an alternating sum, and they conjectured that the coefficients of p S ( x ) expanded in a binomial coefficient basis centered at max ⁡ ( S ) are all nonnegative. In this paper we introduce a new recursive formula for | P ( S ; n ) | without alternating sums and we use this recursion to prove that their conjecture is true.
Closed-form learning of Markov networks from dependency networks

Markov networks (MNs) are a powerful way to compactly represent a joint probability distribution, but most MN structure learning methods are very slow, due to the high cost of evaluating candidates structures. Dependency networks (DNs) represent a probability distribution as a set of conditional probability distributions. DNs are very fast to learn, but the conditional distributions may be inconsistent with each other and few inference algorithms support DNs. In this paper, we present a closed-form method for converting a DN into an MN, allowing us to enjoy both the efficiency of DN learning and the convenience of the MN representation. When the DN is consistent, this conversion is exact. For inconsistent DNs, we present averaging methods that significantly improve the approximation. In experiments on 12 standard datasets, our methods are orders of magnitude faster than and often more accurate than combining conditional distributions using weight learning.
An Incidence Geometry Approach to Dictionary Learning.

We study the Dictionary Learning (aka Sparse Coding) problem of obtaining a sparse representation of data points, by learning dictionary vectors upon which the data points can be written as sparse linear combinations. We view this problem from a geometry perspective as the spanning set of a subspace arrangement, and focus on understanding the case when the underlying hypergraph of the subspace arrangement is specified. For this Fitted Dictionary Learning problem, we completely characterize the combinatorics of the associated subspace arrangements (i.e. their underlying hypergraphs), using incidence geometry. Specifically, a combinatorial rigidity-type theorem is proven that characterizes the hypergraphs of subspace arrangements that generically yield (a) at least one dictionary (b) a locally unique dictionary (i.e. at most a finite number of isolated dictionaries) of the specified size. We are unaware of prior application of combinatorial rigidity techniques in the setting of Dictionary Learning, or even in machine learning. We also provide a systematic classification of problems related to Dictionary Learning together with various approaches, assumptions required and performance.
VARIOUS COVERING SPECTRA FOR COMPLETE METRIC SPACES

Here we study various covering spectra for complete noncompact length spaces with universal covers (including Riemannian manifolds and the pointed Gromov Hausdorff limits of Riemannian manifolds with lower bounds on their Ricci curvature). We relate the covering spectrum to the (marked) shift spectrum of such a space. We define the slipping group generated by elements of the fundamental group whose translative lengths are 0. We introduce a rescaled length, the rescaled covering spectrum and the rescaled slipping group. Applying these notions we prove that certain complete noncompact Riemannian manifolds with nonnegative or positive Ricci curvature have finite fundamental groups. Throughout we suggest further problems both for those interested in Riemannian geometry and those interested in metric space theory.
A Sparse Linear Model and Significance Test for Individual Consumption Prediction

Accurate prediction of user consumption is a key part not only in understanding consumer flexibility and behavior patterns, but in the design of robust and efficient energy saving programs as well. Existing prediction methods usually have high relative errors that can be larger than 30% and have difficulties accounting for heterogeneity between individual users. In this paper, we propose a method to improve prediction accuracy of individual users by adaptively exploring sparsity in historical data and leveraging predictive relationship between different users. Sparsity is captured by popular least absolute shrinkage and selection estimator, while user selection is formulated as an optimal hypothesis testing problem and solved via a covariance test. Using real-world data from PG&E, we provide extensive simulation validation of the proposed method against well-known techniques such as support vector machine, principle component analysis combined with linear regression, and random forest. The results demonstrate that our proposed methods are operationally efficient because of linear nature, and achieve optimal prediction performance.