cssi/SciSciGPT-SciSciNet huggingface dataset:
Personality Moderates Intervention Effects on Cognitive Function: A 6-Week Conversation-Based Intervention

BACKGROUND AND OBJECTIVES Social isolation is associated with a higher risk of dementia. We previously conducted and showed the efficacy of an intervention which uses conversation (the core component of social interactions) as a tool to enhance cognitive function. We now explore whether cognitive improvements through conversation-based intervention depend on an individual's personality. RESEARCH DESIGN AND METHODS We reexamined data from a 6-week randomized controlled trial (ClinicalTrials.gov Number: NCT01571427) to determine whether conversation-based intervention effects were moderated by personality traits in 83 older adults (mean age = 80.51 years, 49 cognitively intact, 34 individuals with mild cognitive impairment). The intervention group participated in daily 30-min face-to-face semi-structured conversations with trained interviewers through a web-enabled system for 6 weeks. At baseline, psychosocial questionnaires and a neuropsychological battery were completed. RESULTS Intervention group participants with high agreeableness, conscientiousness, and extraversion exhibited significant improvements in language-based executive function tasks beyond changes in the control group (ps < .05). An opposite pattern for delayed recall memory and working memory tasks emerged among highly extraverted participants (ps < .05). DISCUSSION AND IMPLICATIONS Our exploratory findings suggest the adaptive role of personality traits in conversation-based cognitive interventions may be limited to tasks incorporating a language component, and offer initial evidence for personalized approaches to cognitive health in late life.
Pheromones and Nutritional Signals Regulate the Developmental Reliance on let-7 Family MicroRNAs in C. elegans.

Summary Adverse environmental conditions can affect rates of animal developmental progression and lead to temporary developmental quiescence (diapause), exemplified by the dauer larva stage of the nematode Caenorhabditis elegans (C. elegans). Remarkably, patterns of cell division and temporal cell-fate progression in C. elegans larvae are not affected by changes in developmental trajectory. However, the underlying physiological and gene regulatory mechanisms that ensure robust developmental patterning despite substantial plasticity in developmental progression are largely unknown. Here, we report that diapause-inducing pheromones correct heterochronic developmental cell lineage defects caused by insufficient expression of let-7 family microRNAs in C. elegans. Moreover, two conserved endocrine signaling pathways, DAF-7/TGF-β and DAF-2/Insulin, that confer on the larva diapause and non-diapause alternative developmental trajectories interact with the nuclear hormone receptor, DAF-12, to initiate and regulate a rewiring of the genetic circuitry controlling temporal cell fates. This rewiring includes engagement of certain heterochronic genes, lin-46, lin-4, and nhl-2, that are previously associated with an altered genetic program in post-diapause animals, in combination with a novel ligand-independent DAF-12 activity, to downregulate the critical let-7 family target Hunchback-like-1 (HBL-1). Our results show how pheromone or endocrine signaling pathways can coordinately regulate both developmental progression and cell-fate transitions in C. elegans larvae under stress so that the developmental schedule of cell fates remains unaffected by changes in developmental trajectory.
Aminosugar motifs via an allene aziridination strategy

Abstract Aminosugar motifs occur in many biologically active natural products and pharmaceuticals; however, stereocontrolled access to diverse structures with minimal use of protecting groups and oxidation state changes is challenging. This paper describes a chemo-, regio-, and stereoselective approach to aminosugar motifs that utilizes an allene aziridination strategy to rapidly install three of the contiguous heteroatom-bearing carbons with stereochemical flexibility.
Palladium-Catalyzed Heteroannulation of 1,3-Dienes To Form α-Alkylidene-γ-butyrolactones

α-Alkylidene-γ-butyrolactones are readily prepared by the palladium-catalyzed heteroannulation of a variety of 1,3-dienes by α-iodo and α-bromo acrylic acids. The best results are obtained by employing a catalytic amount of the sterically hindered chelating alkyl phosphine D-t-BPF [(di-tert-butylphosphino)ferrocene]. In most cases, this process is highly regioselective. The reaction is believed to proceed via (1) oxidative addition of the vinylic halide to Pd(0), (2) organopalladium addition to the less hindered end of the 1,3-diene to form a π-allylpalladium intermediate, and (3) nucleophilic displacement of the palladium by the carboxylate ion.
An Escherichia coli Nitrogen Starvation Response Is Important for Mutualistic Coexistence with Rhodopseudomonas palustris

Microbial mutualistic cross-feeding interactions are ubiquitous and can drive important community functions. Engaging in cross-feeding undoubtedly affects the physiology and metabolism of individual species involved. However, the nature in which an individual species' physiology is influenced by cross-feeding and the importance of those physiological changes for the mutualism have received little attention. We previously developed a genetically tractable coculture to study bacterial mutualisms. The coculture consists of fermentative Escherichia coli and phototrophic Rhodopseudomonas palustris In this coculture, E. coli anaerobically ferments sugars into excreted organic acids as a carbon source for R. palustris In return, a genetically engineered R. palustris strain constitutively converts N2 into NH4+, providing E. coli with essential nitrogen. Using transcriptome sequencing (RNA-seq) and proteomics, we identified transcript and protein levels that differ in each partner when grown in coculture versus monoculture. When in coculture with R. palustris, E. coli gene expression changes resembled a nitrogen starvation response under the control of the transcriptional regulator NtrC. By genetically disrupting E. coli NtrC, we determined that a nitrogen starvation response is important for a stable coexistence, especially at low R. palustris NH4+ excretion levels. Destabilization of the nitrogen starvation regulatory network resulted in variable growth trends and, in some cases, extinction. Our results highlight that alternative physiological states can be important for survival within cooperative cross-feeding relationships.IMPORTANCE Mutualistic cross-feeding between microbes within multispecies communities is widespread. Studying how mutualistic interactions influence the physiology of each species involved is important for understanding how mutualisms function and persist in both natural and applied settings. Using a bacterial mutualism consisting of Rhodopseudomonas palustris and Escherichia coli growing cooperatively through bidirectional nutrient exchange, we determined that an E. coli nitrogen starvation response is important for maintaining a stable coexistence. The lack of an E. coli nitrogen starvation response ultimately destabilized the mutualism and, in some cases, led to community collapse after serial transfers. Our findings thus inform on the potential necessity of an alternative physiological state for mutualistic coexistence with another species compared to the physiology of species grown in isolation.
New A2/3-xRh2O4 compounds with the CaFe2O4 structure where A is a rare earth or Bi.

New compounds of the type R2/3−xRh2O4 with the CaFe2O4 structure have been prepared, where R is a rare earth. For crystals grown in a Bi/V/O flux, the rare earth was partially replaced by Bi. No evidence of ordering of the A cation vacancies is found, but the A cations are displaced from the ideal A cation site by about 0.24 A. Electrical conductivity measurements on crystals suggest that the materials are degenerate semiconductors with Seebeck measurements showing p-type behavior. This is consistent with our observation that x in R2/3−xRh2O4 ranges up to about 0.09. The compounds were also characterized by magnetic susceptibility and diffuse reflectance measurements.
Phase transfer catalysis and ultrasound in tandem alkylation of azo dyes for bifunctional molecules

Abstract Ultrasound has been found to enhance N -substitution against elimination in the reaction of carbazole-containing bromide with disperse orange 3 derivative under PTC conditions.
Gold catalyzed synthesis of fluorinated tetrahydrofurans and lactones

Abstract The gold catalyzed tandem cycloisomerization/fluorination of alkynylic alcohols gives difluoro hydroxyl tetrahydrofurans at room temperature in moderate to good yields. The gold catalyzed monofluorolactonization of alkynylic acids to the corresponding fluoro lactones was also explored.
High-Temperature Solution-Phase Syntheses of Metal-Oxide Nanocrystals

This review highlights the recent progress in synthesizing some representative metal-oxide nanocrystals (MONCs) with controlled magnetic, electronic, and optical properties for potentially importan...
Cell cycle entry triggers a switch between two modes of Cdc42 activation during yeast polarization

Living cells are not always symmetrical. Instead they are often polarized, with a distinct front and back or top and bottom. Cell polarization influences many processes, including how a cell moves and grows, and where it will divide. Breaking symmetry – in other words, making one part of a cell different from the rest – regularly involves a small protein called Cdc42, which can switch between an active and inactive form. This protein is found in a range of organisms from fungi to animals. Budding yeast is a valuable model to study cell polarization. This single-celled fungus polarizes in order to produce a daughter cell or ‘bud’ that emerges out of one end of the mother cell. To become polarized, the mother cell accumulates active Cdc42 in a small area of the cell membrane. This region then becomes the front of the cell, from where the future bud will emerge. However, it is not fully understood how active Cdc42 accumulates at only one place. One model proposed that some molecules of active Cdc42 that are already present on the membrane, recruit polarity proteins that in turn activate other, inactive Cdc42 molecules. This self-amplifying loop could eventually build up a local pool of active Cdc42. However, it has proved challenging to directly test this model. Optogenetics is a technique in which a beam of light is used to manipulate proteins inside cells in a precise manner. The method was first developed in the field of neuroscience over a decade ago, and has more recently been applied to cell biology. Now, Witte et al. have used optogenetics to move polarity proteins to defined places on the membrane of yeast cells and analyse how this change affected the pattern of Cdc42 activation. The experiments showed that polarity proteins not only activate Cdc42 but they also recruit more polarity proteins to the same place. The resulting positive feedback loop leads to active Cdc42 accumulating at one site on the membrane. Further work showed that this mechanism only operates in this manner just before the mother cell replicates its DNA, which is when a yeast cell will normally polarize. These results provide a new perspective on how cells can make one part of the cell different from the rest. Beyond yeast, cell polarization plays a major role when animals, including humans, are developing as embryos or healing wounds. These processes are often controlled by a protein that is equivalent to Cdc42 or by other highly related switch-like proteins. This means that yeast will continue to provide a useful model to study these processes in the laboratory. Lastly, the optogenetics approach developed Witte et al. will be useful to dissect other processes that involve molecules being located at specific place in a cell at specific time.
2-alkylidene oxetanes by stereospecific elimination of mesylates

α-Mesyloxyoxetanes undergo stereospecific elimination to 2-alkylidene oxetanes upon treatment with potassium t-butoxide.
Coarse-grained simulation reveals key features of HIV-1 capsid self-assembly

The maturation of HIV-1 viral particles is essential for viral infectivity. During maturation, many copies of the capsid protein (CA) self-assemble into a capsid shell to enclose the viral RNA. The mechanistic details of the initiation and early stages of capsid assembly remain to be delineated. We present coarse-grained simulations of capsid assembly under various conditions, considering not only capsid lattice self-assembly but also the potential disassembly of capsid upon delivery to the cytoplasm of a target cell. The effects of CA concentration, molecular crowding, and the conformational variability of CA are described, with results indicating that capsid nucleation and growth is a multi-stage process requiring well-defined metastable intermediates. Generation of the mature capsid lattice is sensitive to local conditions, with relatively subtle changes in CA concentration and molecular crowding influencing self-assembly and the ensemble of structural morphologies.
Engineering Transcriptional Regulator Effector Specificity Using Computational Design and In Vitro Rapid Prototyping: Developing a Vanillin Sensor.

The pursuit of circuits and metabolic pathways of increasing complexity and robustness in synthetic biology will require engineering new regulatory tools. Feedback control based on relevant molecules, including toxic intermediates and environmental signals, would enable genetic circuits to react appropriately to changing conditions. In this work, variants of qacR, a tetR family repressor, were generated by computational protein design and screened in a cell-free transcription–translation (TX-TL) system for responsiveness to a new targeted effector. The modified repressors target vanillin, a growth-inhibiting small molecule found in lignocellulosic hydrolysates and other industrial processes. Promising candidates from the in vitro screen were further characterized in vitro and in vivo in a gene circuit. The screen yielded two qacR mutants that respond to vanillin both in vitro and in vivo. While the mutants exhibit some toxicity to cells, presumably due to off-target effects, they are prime starting points...
Intramolecular Olefin Diamination for the Stereoselective Synthesis of 3-Aminopiperidines

A general method for the direct intramolecular diamination of terminal olefins is presented. The reaction, mediated by hypervalent iodine oxidants, produces substituted 3-aminopiperidine scaffolds with high regio- and stereoselectivity, rendering this process relevant to both medicinal chemistry and natural products synthesis.
Phyllolactones A–E: new bishomoscalarane sesterterpenes from the marine sponge Phyllospongia lamellosa

Abstract Five new bishomoscalarane sesterterpenes, phyllolactones A–E ( 1 – 5 ), have been isolated from the marine sponge Phyllospongia lamellosa . The structures were elucidated by 1D and 2D 1 H and 13 C NMR, unambiguous assignments of overlapping 1 H and 13 C resonances were made by analysis of an HSQC–TOCSY spectrum, and relative stereochemistry established by analysis of coupling constants and ROESY and NOESY spectra. A summary of previously reported carbolactone-containing bishomoscalarane structures and the range of 13 C chemical shifts arising from the various oxy substituents at C-3, C-12, C-16, C-20 and C-24 is included. Phyllolactones A–E modestly inhibit HIV-1 envelope-mediated fusion in vitro with IC 50 s of ∼2 μM, and show negligible cytotoxicity toward the cell lines used in the fusion assay (BS-C-1 and NIH 3T3).
Synthesis of substituted cyclobutenediones by the palladium catalyzed cross-coupling of halocyclobutenediones with organostannanes.

Abstract Halo-substituted cyclobutenediones undergo palladium catalyzed cross-coupling with organostannanes providing a mild method for the synthesis of substituted cyclobutenediones.
Sulfinimine-Mediated Asymmetric Synthesis of (R)-(4-Methoxy-3,5-dihydroxyphenyl)glycine: The Central Amino Acid of Vancomycin and Related Agents

The sulfinimine asymmetric Strecker synthesis, the addition of ethyl aluminum cyano alkoxide, “EtAl(OR)CN”, to sulfinimine 10, has been applied to a concise highly efficient four-step enantioselective synthesis of (R)-(4-methoxy-3,5-dihydroxyphenyl)glycine (3) and its derivatives in >97% ee. These epimerization-sensitive arylglycines are precursors of the key central amino acid of vancomycin and related glycopeptide antibiotics.
Na2Ln2Ti3-xMnxO10 (Ln = Sm, Eu, Gd, and Dy; 0 ⩽ x ⩽ 1): A New Series of Ion-Exchangeable Layered Perovskites Containing B-Site Manganese

Na2Ln2Ti3-xMnxO10 (Ln = Sm, Eu, Gd, and Dy; 0 ≤ x ≤ 1), a new series of triple-layer Ruddlesden−Popper phases, were synthesized by direct solid-state reaction. The smaller lanthanides enhance manga...
Selective esterification of the polyphenol resveratrol at the 4′-position

Abstract Selective esterification of the polyphenol resveratrol was performed under thermodynamic conditions using NaH and acid anhydrides to directly access 4′-esters. Standard conditions with acetyl chloride and pyridine showed poor selectivity, favoring esterification at the 3-position. The extended 4′-phenolate anion is generated in preference to the 3-phenolate under the new anhydride-sodium hydride-DMSO conditions. Acylation occurs to access the 4′-ester products with modest selectivity and yield with minimal formation of the 3-monoester, 3,5-diester, and triester products.
Diphenyl methylphosphonate as a phosphonylation reagent with high diastereoselectivity at phosphorus

Abstract Reaction of diphenyl methylphosphonate with lithium alkoxides generated in situ from alcohols and butyllithium gives phenyl alkyl methylphosphonate diesters even with hindered alcohols and with high diastereoselectivity at phosphorus.
Benzothiazines in synthesis. Eight-membered ring formation in an intramolecular Friedel–Crafts reaction

Treatment of certain benzothiazines bearing allylic bromides side chains with indium tribromide resulted in the formation of eight-membered rings in addition to the expected six-membered rings.
Hole-transfer catalyzed reaction: One-electron oxidation as a strategy for the selective cyclopropanation of π bonds

Abstract The cyclopropanation of alkenes, dienes and trienes with ethyl diazoacetate catalyzed by tris(4-bromophenyl)aminium hexachloroantimonate have been studied. The efficiency and selectivity of cyclopropanation is based solely upon, and is highly sensitive to, the ease of ionization of π bonds in the substrate. Simple double bonds such as norbornene and 1-octene are not amenable to cyclopropanation via this method.
FusoPortal: an Interactive Repository of Hybrid MinION-Sequenced Fusobacterium Genomes Improves Gene Identification and Characterization

Here we present FusoPortal, an interactive repository of Fusobacterium genomes that were sequenced using a hybrid MinION long-read sequencing pipeline, followed by assembly and annotation using a diverse portfolio of predominantly open-source software. Significant efforts were made to provide genomic and bioinformatic data as downloadable files, including raw sequencing reads, genome maps, gene annotations, protein functional analysis and classifications, and a custom BLAST server for FusoPortal genomes. FusoPortal has been initiated with eight complete genomes, of which seven were previously only drafts that ranged from 24 to 67 contigs. We have showcased that the genomes in FusoPortal provide accurate open reading frame annotations and have corrected a number of large (>3-kb) genes that were previously misannotated due to contig boundaries. In summary, FusoPortal (http://fusoportal.org) is the first database of MinION-sequenced and completely assembled Fusobacterium genomes, and this central Fusobacterium genomic and bioinformatic resource will aid the scientific community in developing a deeper understanding of how this human pathogen contributes to an array of diseases, including periodontitis and colorectal cancer.IMPORTANCE In this report, we describe a hybrid MinION whole-genome sequencing pipeline and the genomic characteristics of the first eight Fusobacterium strains deposited in the FusoPortal database. This collection of highly accurate and complete genomes drastically improves upon previous multicontig assemblies by correcting and newly identifying a significant number of open reading frames. We believe that the availability of this resource will result in the discovery of proteins and molecular mechanisms used by an oral pathogen, with the potential to further our understanding of how Fusobacterium nucleatum contributes to a repertoire of diseases, including periodontitis, preterm birth, and colorectal cancer.
Rate coefficients for the reaction of OH with HONO between 298 and 373 K

Rate coefficients, k1, for the reaction OH + HONO H2O + NO2, have been measured over the temperature range 298 to 373 K. The OH radicals were produced by 266 nm laser photolysis of O3 in the presence of a large excess of H2O vapor. The temporal profiles of OH were measured under pseudo-first-order conditions, in an excess of HONO, using time resolved laser induced fluorescence. The measured rate coefficient exhibits a slight negative temperature dependence, with k1 = (2.8 ± 1.3) × 10−12 exp((260 ± 140)/T) cm3 molecule−1 s−1. The measured values of k1 are compared with previous determinations and the atmospheric implications of our findings are discussed.
Age-related Differences in Prestimulus Subsequent Memory Effects Assessed with Event-related Potentials.

Prestimulus subsequent memory effects (preSMEs)—differences in neural activity elicited by a task cue at encoding that are predictive of later memory performance—are thought to reflect differential engagement of preparatory processes that benefit episodic memory encoding. We investigated age differences in preSMEs indexed by differences in ERP amplitude just before the onset of a study item. Young and older adults incidentally encoded words for a subsequent memory test. Each study word was preceded by a task cue that signaled a judgment to perform on the word. Words were presented for either a short (300 msec) or long (1000 msec) duration with the aim of placing differential benefits on engaging preparatory processes initiated by the task cue. ERPs associated with subsequent successful and unsuccessful recollection, operationalized here by source memory accuracy, were estimated time-locked to the onset of the task cue. In a late time window (1000–2000 msec after onset of the cue), young adults demonstrated frontally distributed preSMEs for both the short and long study durations, albeit with opposite polarities in the two conditions. This finding suggests that preSMEs in young adults are sensitive to perceived task demands. Although older adults showed no evidence of preSMEs in the same late time window, significant preSMEs were observed in an earlier time window (500–1000 msec) that was invariant with study duration. These results are broadly consistent with the proposal that older adults differ from their younger counterparts in how they engage preparatory processes during memory encoding.
Synthesis and structure of pyrazolo[5,1-a]isoindol-8-ones from Aromatic Ortho Diesters†

The title compounds 2, have now been shown to arise in certain cases from condensation of aromatic ortho-diesters with ketone, where formerly only indeno[1,2-c]pyrazol-4(1H)-ones 3 have been reported from such reaction. Heretofore 2 was obtained in a less direct fashion from phthalaldehydic acid esters. When hetero-aromatic diesters were employed, new heterocyclic ring systems as represented by 2a,b,c were prepared for the first time. Structures of 2 have been verified from detailed 1H and 13C nmr studies, while representative intermediates 4–9 in the condensation of diesters to 2 have been isolated and identified.
A ring-closing yne-carbonyl metathesis of ynamides.

An acid-catalyzed ring-closing ynamide-carbonyl metathesis is described here. This hetero RCM methodology is applicable to the construction of carbocycles as well as heterocycles such as chromenes,...
An approach toward the total synthesis of subergorgic acid

Abstract Ireland–Claisen rearrangement of a substituted alkenyl cyclopentanecarboxylate provided a monocyclic isomer containing the proper stereochemistry for four of the five stereogenic centers in subergorgic acid. Efforts to construct the additional rings in the molecule were thwarted as a result of steric and other factors. The results provide insights regarding the Ireland–Claisen rearrangement in five-membered ring systems. The formation of spiro-compounds from sterically and stereoelectronically demanding systems as reported herein has the potential to serve as a general strategy for the synthesis of such sub-units in both natural and unnatural products.
Statistical Local Binary Patterns (SLBP): Application To Prostate Cancer Gleason Score Prediction From whole Slide Pathology Images

Computerized whole slide image analysis is important for assisting pathologists in cancer grading and predicting patient clinical outcomes. However, it is challenging to analyze whole slide image (WSI) at cellular level due to its huge size and nuclear variations. For efficient WSI analysis, this paper presents a general texture descriptor, statistical local binary patterns (SLBP), which is applied to prostate cancer Gleason score prediction from WSI. Unlike traditional local binary patterns (LBP) and many its variants, the presented SLBP encodes local texture patterns via analyzing both median and standard deviation over a regional sampling scheme, so that it can capture more micro-and macro-structure information in the image. Experiments on Gleason score prediction have been performed on 317 different patient cases selected from the cancer genome atlas (TCGA) dataset. The presented SLBP descriptor provides over 80% accuracy on two-class (grade $\leq 7$ vs grade $\geq 8$) distinction, which is superior to traditional texture descriptors such as histogram, Haralick and other state-of-the-art LBP variants.
Generalized Linear Models for Aggregated Data

Databases in domains such as healthcare are routinely released to the public in aggregated form. Unfortunately, nave modeling with aggregated data may signicantly diminish the accuracy of inferences at the individ- ual level. This paper addresses the scenario where features are provided at the individual level, but the target variables are only avail- able as histogram aggregates or order statis- tics. We consider a limiting case of gener- alized linear modeling when the target vari- ables are only known up to permutation, and explore how this relates to permutation test- ing; a standard technique for assessing statis- tical dependency. Based on this relationship, we propose a simple algorithm to estimate the model parameters and individual level in- ferences via alternating imputation and stan- dard generalized linear model tting. Our re-
Interpolation for Brill-Noether space curves

In this note we compute the number of general points through which a general Brill–Noether space curve passes.
Towards Geo-Distributed Machine Learning.

In large organizations, data is “born” in data centers all around the world. Learning requires a global view of such data. This new class of geo-distributed machine learning (GDML) applications need to cope with: 1) scarce and expensive cross-data center bandwidth, and 2) growing privacy concerns that are pushing for stricter data sovereignty regulations. In this paper, we formalize this problem, show that the current state-of-the-art lacks proper support for GDML applications, and propose an initial system and algorithm that perform training in a geo-distributed fashion. Our empirical evaluation confirms the general validity of our approach, but many research challenges remain open.
Constraining strong c-Wilf equivalence using cluster poset asymptotics

Abstract Let π ∈ S m and σ ∈ S n be permutations. An occurrence of π in σ as a consecutive pattern is a subsequence σ i σ i + 1 ⋯ σ i + m − 1 of σ with the same order relations as π. We say that patterns π , τ ∈ S m are strongly c-Wilf equivalent if for all n and k, the number of permutations in S n with exactly k occurrences of π as a consecutive pattern is the same as for τ. In 2018, Dwyer and Elizalde [6] conjectured (generalizing a conjecture of Elizalde [8] from 2012) that if π , τ ∈ S m are strongly c-Wilf equivalent, then ( τ 1 , τ m ) is equal to one of ( π 1 , π m ) , ( π m , π 1 ) , ( m + 1 − π 1 , m + 1 − π m ) , or ( m + 1 − π m , m + 1 − π 1 ) . We prove this conjecture using the cluster method introduced by Goulden and Jackson in 1979 [12] , which Dwyer and Elizalde used to prove that | π 1 − π m | = | τ 1 − τ m | . A consequence of our result is the full classification of c-Wilf equivalence for a special class of permutations, the non-overlapping permutations. Our approach uses analytic methods to approximate the number of linear extensions of the “cluster posets” defined by Elizalde and Noy in 2012 [11] .
Twin Primes and the Zeros of the Riemann Zeta Function

The Legendre-type relation for the counting function of ordinary twin primes is reworked in terms of the inverse of the Riemann zeta function. Its analysis sheds light on the distribution of the zeros of the Riemann zeta function in the critical strip and their link to the twin prime problem.
Normal 0-1 Polytopes

We study the question of when 0-1 polytopes are normal or, equivalently, have the integer decomposition property. In particular, we shall associate to each 0-1 polytope a labeled hypergraph, and examine the equality between its Ehrhart and polytopal rings via the combinatorial structures of the labeled hypergraph.
Derived Koszul duality and TQ-homology completion of structured ring spectra

Abstract Working in the context of symmetric spectra, we consider algebraic structures that can be described as algebras over an operad O . Topological Quillen homology, or TQ -homology, is the spectral algebra analog of Quillen homology and stabilization. Working in a framework for homotopical descent, the associated TQ -homology completion map appears as the unit map of an adjunction comparing the homotopy categories of O -algebra spectra with coalgebra spectra over the associated comonad via TQ -homology. We prove that this adjunction between homotopy categories can be turned into an equivalence by replacing O -algebras with the full subcategory of 0-connected O -algebras. We also construct the spectral algebra analog of the unstable Adams spectral sequence that starts from the TQ -homology groups TQ ⁎ ( X ) of an O -algebra X, and prove that it converges strongly to π ⁎ ( X ) when X is 0-connected.
A categorification of the chromatic symmetric function

Abstract The Stanley chromatic symmetric function X G of a graph G is a symmetric function generalization of the chromatic polynomial and has interesting combinatorial properties. We apply the ideas from Khovanov homology to construct a homology theory of graded S n -modules, whose graded Frobenius series Frob G ( q , t ) specializes to the chromatic symmetric function at q = t = 1 . This homology theory can be thought of as a categorification of the chromatic symmetric function, and it satisfies homological analogues of several familiar properties of X G . In particular, the decomposition formula for X G discovered recently by Orellana, Scott, and independently by Guay-Paquet, is lifted to a long exact sequence in homology.
An algebraic-combinatorial proof technique for the GM-MDS conjecture

This paper considers the problem of designing maximum distance separable (MDS) codes over small fields with constraints on the support of their generator matrices. For any given m χ n binary matrix M, the GM-MDS conjecture, due to Dau et al., states that if M satisfies the so-called MDS condition, then for any field F of size q ≥ n + m − 1, there exists an [n, m] q MDS code whose generator matrix G, with entries in F, fits M (i.e., M is the support matrix of G). Despite all the attempts by the coding theory community, this conjecture remains still open in general. It was shown, independently by Yan et al. and Dau et al., that the GM-MDS conjecture holds if the following conjecture, referred to as the TM-MDS conjecture, holds: if M satisfies the MDS condition, then the determinant of a transformation matrix T, such that TV fits M, is not identically zero, where V is a Vandermonde matrix with distinct parameters. In this work, we generalize the TM-MDS conjecture, and present an algebraic-combinatorial approach based on polynomial-degree reduction for proving this conjecture. Our proof technique's strength is based primarily on reducing inherent combinatorics in the proof. We demonstrate the strength of our technique by proving the TM-MDS conjecture for the cases where the number of rows (m) of M is upper bounded by 5. For this class of special cases of M where the only additional constraint is on m, only cases with m 4.
Deep Reinforcement Learning Based Resource Allocation for V2V Communications

In this paper, we develop a novel decentralized resource allocation mechanism for vehicle-to-vehicle (V2V) communications based on deep reinforcement learning, which can be applied to both unicast and broadcast scenarios. According to the decentralized resource allocation mechanism, an autonomous “agent,” a V2V link or a vehicle, makes its decisions to find the optimal sub-band and power level for transmission without requiring or having to wait for global information. Since the proposed method is decentralized, it incurs only limited transmission overhead. From the simulation results, each agent can effectively learn to satisfy the stringent latency constraints on V2V links while minimizing the interference to vehicle-to-infrastructure communications.
Latent contextual bandits and their application to personalized recommendations for new users

Personalized recommendations for new users, also known as the cold-start problem, can be formulated as a contextual bandit problem. Existing contextual bandit algorithms generally rely on features alone to capture user variability. Such methods are inefficient in learning new users' interests. In this paper we propose Latent Contextual Bandits. We consider both the benefit of leveraging a set of learned latent user classes for new users, and how we can learn such latent classes from prior users. We show that our approach achieves a better regret bound than existing algorithms. We also demonstrate the benefit of our approach using a large real world dataset and a preliminary user study.
On estimating multi-attribute choice preferences using private signals and matrix factorization

Revealed preference theory studies the possibility of modeling an agent's revealed preferences and the construction of a consistent utility function. However, modeling agent's choices over preference orderings is not always practical and demands strong assumptions on human rationality and data-acquisition abilities. Therefore, we propose a simple generative choice model where agents are assumed to generate the choice probabilities based on latent factor matrices that capture their choice evaluation across multiple attributes. Since the multi-attribute evaluation is typically hidden within the agent's psyche, we consider a signaling mechanism where agents are provided with choice information through private signals, so that the agent's choices provide more insight about his/her latent evaluation across multiple attributes. We estimate the choice model via a novel multi-stage matrix factorization algorithm that minimizes the average deviation of the factor estimates from choice data. Simulation results are presented to validate the estimation performance of our proposed algorithm.
Three-term polynomial progressions in subsets of finite fields

Bourgain and Chang recently showed that any subset of $$\mathbb{F}_p$$ of density ≫p−1/15 contains a nontrivial progression x, x + y, x + y2. We answer a question of theirs by proving that if P1, P2 ∈ ℤ[y] are linearly independent and satisfy P1(0) = P2(0) = 0, then any subset of $$\mathbb{F}_p$$ of density ≫P1,P2p−1/24 contains a nontrivial polynomial progression x, x + P1(y), x + P2(y).
Completion of tree metrics and rank 2 matrices

Abstract Motivated by applications to low-rank matrix completion, we give a combinatorial characterization of the independent sets in the algebraic matroid associated to the collection of m × n rank-2 matrices and n × n skew-symmetric rank-2 matrices. Our approach is to use tropical geometry to reduce this to a problem about phylogenetic trees which we then solve. In particular, we give a combinatorial description of the collections of pairwise distances between several taxa that may be arbitrarily prescribed while still allowing the resulting dissimilarity map to be completed to a tree metric.
Discrepancy properties for random regular digraphs

For the uniform random regular directed graph we prove concentration inequalities for (1) codegrees and (2) the number of edges passing from one set of vertices to another. As a consequence, we can deduce discrepancy properties for the distribution of edges essentially matching results for Erdős–Renyi digraphs obtained from Chernoff-type bounds. The proofs make use of the method of exchangeable pairs, developed for concentration of measure by Chatterjee in (Chatterjee, Probab Theory and Relat Fields 138 (2007), 305–321). Exchangeable pairs are constructed using two involutions on the set of regular digraphs: a well-known “simple switching” operation, as well as a novel “reflection” operation. © 2016 Wiley Periodicals, Inc. Random Struct. Alg., 2016
Estimation in the Group Action Channel

We analyze the problem of estimating a signal from multiple measurements on a group action channel that linearly transforms a signal by a random group action followed by a fixed projection and additive Gaussian noise. This channel is motivated by applications such as multi-reference alignment and cryo-electron microscopy. We focus on the large noise regime prevalent in these applications. We give a lower bound on the mean square error (MSE) of any asymptotically unbiased estimator of the orbit in terms of the signal's moment tensors, which implies that the MSE is bounded away from 0 when $N/\sigma^{2d}$ is bounded from above, where $N$ is the number of observations, $\sigma$ is the noise standard deviation, and $d$ is the so-called moment order cutoff. In contrast, the maximum likelihood estimator is shown to be consistent if $N/\sigma^{2d}$ diverges.
Neural Models of Factuality

We present two neural models for event factuality prediction, which yield significant performance gains over previous models on three event factuality datasets: FactBank, UW, and MEANTIME. We also present a substantial expansion of the It Happened portion of the Universal Decompositional Semantics dataset, yielding the largest event factuality dataset to date. We report model results on this extended factuality dataset as well.
Why is posterior sampling better than optimism for reinforcement learning

Computational results demonstrate that posterior sampling for reinforcement learning (PSRL) dramatically outperforms existing algorithms driven by optimism, such as UCRL2. We provide insight into the extent of this performance boost and the phenomenon that drives it. We leverage this insight to establish an O(H√SAT) Bayesian regret bound for PSRL in finite-horizon episodic Markov decision processes. This improves upon the best previous Bayesian regret bound of O(HS √AT) for any reinforcement learning algorithm. Our theoretical results are supported by extensive empirical evaluation.
Algorithms for Lipschitz Learning on Graphs

We develop fast algorithms for solving regression problems on graphs where one is given the value of a function at some vertices, and must find its smoothest possible extens ion to all vertices. The extension we compute is the absolutely minimal Lipschitz extension, and is the limit for large p of p-Laplacian regularization. We present an algorithm that computes a minimal Lipschitz extension in expected linear time, and an algorithm that computes an absolutely minimal Lipschitz extension in expected time e O(mn). The latter algorithm has variants that seem to run much faster in practice. These extensions are particularly amenable to regularization: we can perform l0regularization on the given values in polynomial time and l1-regularization on the initial function values and on graph edge weights in time e O(m 3/2 ). Our definitions and algorithms naturally extend to directed graphs.
SparsityBoost: a new scoring function for learning Bayesian network structure

We give a new consistent scoring function for structure learning of Bayesian networks. In contrast to traditional approaches to score-based structure learning, such as BDeu or MDL, the complexity penalty that we propose is data-dependent and is given by the probability that a conditional independence test correctly shows that an edge cannot exist. What really distinguishes this new scoring function from earlier work is that it has the property of becoming computationally easier to maximize as the amount of data increases. We prove a polynomial sample complexity result, showing that maximizing this score is guaranteed to correctly learn a structure with no false edges and a distribution close to the generating distribution, whenever there exists a Bayesian network which is a perfect map for the data generating distribution. Although the new score can be used with any search algorithm, we give empirical results showing that it is particularly effective when used together with a linear programming relaxation approach to Bayesian network structure learning.
On the fifth-order KdV equation: Local well-posedness and lack of uniform continuity of the solution map

Abstract In this paper we prove that the following fifth-order equation arising from the KdV hierarchy { ∂ t u + ∂ x 5 u + c 1 ∂ x u ∂ x 2 u + c 2 u ∂ x 3 u = 0 , u : R t × R x → R , u ( 0 , x ) = u 0 ( x ) , u 0 ∈ H s ( R ) is locally well-posed in H s ( R ) for s > 5 2 . Also, we prove the solution map of the equation is not uniformly continuous on a bounded set.
Big Data on the Rise? - Testing Monotonicity of Distributions.

The field of property testing of probability distributions, or distribution testing, aims to provide fast and (most likely) correct answers to questions pertaining to specific aspects of very large datasets. In this work, we consider a property of particular interest, monotonicity of distributions. We focus on the complexity of monotonicity testing across different models of access to the distributions; and obtain results in these new settings that differ significantly from the known bounds in the standard sampling model.
A Constant-Factor Bi-Criteria Approximation Guarantee for k-means++

This paper studies the $k$-means++ algorithm for clustering as well as the class of $D^\ell$ sampling algorithms to which $k$-means++ belongs. It is shown that for any constant factor $\beta > 1$, selecting $\beta k$ cluster centers by $D^\ell$ sampling yields a constant-factor approximation to the optimal clustering with $k$ centers, in expectation and without conditions on the dataset. This result extends the previously known $O(\log k)$ guarantee for the case $\beta = 1$ to the constant-factor bi-criteria regime. It also improves upon an existing constant-factor bi-criteria result that holds only with constant probability.
Analysis of equilibria and strategic interaction in complex networks

This paper studies n-person simultaneous-move games with linear best response function, where individuals interact within a given network structure. This class of games have been used to model various settings, such as, public goods, belief formation, peer effects, and oligopoly. The purpose of this paper is to study the effect of the network structure on Nash equilibrium outcomes of this class of games. Bramoulle et al. derived conditions for uniqueness and stability of a Nash equilibrium in terms of the smallest eigenvalue of the adjacency matrix representing the network of interactions. Motivated by this result, we study how local structural properties of the network of interactions affect this eigenvalue, influencing game equilibria. In particular, we use algebraic graph theory and convex optimization to derive new bounds on the smallest eigenvalue in terms of the distribution of degrees, cycles, and other relevant substructures. We illustrate our results with numerical simulations involving online social networks.
Submanifolds of Hermitian Symmetric Spaces

We study the problem of non-relativity for a complex Euclidean space and a bounded symmetric domain equipped with their canonical metrics. In particular, we answer a question raised by Di Scala. This paper is dedicated to the memory of Salah Baouendi, a great teacher and a close friend to many of us.
Two examples of unbalanced Wilf-equivalence

We prove that the set of patterns {1324,3416725} is Wilf-equivalent to the pattern 1234 and that the set of patterns {2143,3142,246135} is Wilf-equivalent to the set of patterns {2413,3142}. These are the first known unbalanced Wilf-equivalences for classical patterns between finite sets of patterns. A pattern is an equivalence class of sequences under order-isomorphism. Two sequences �1 and �2 over totally ordered alphabets are order-isomorphic if, for any pair of positions i and j, we have �1(i) < �1(j) if and only if �2(i) < �2(j). We identify a pattern with its canonical representative, in which the kth smallest letter is k. We say that a permutation � contains a patternifhas a subsequence order-isomorphic to �, otherwise we say that � avoids �. We denote the set of permutations of length n by Sn, the set of permutations in Sn avoiding patternby Avn(�), and the set of permutations in Sn avoiding every pattern in a setby Avn(�). We say that two (sets of) patterns � ' and � '' are Wilf-equivalent, denoted � ' ∼ � '' , if |Avn(� ' )| = |Avn(� '' )| for all n ∈ N. We call a Wilf-equivalence unbalanced if the two sets of patterns do not contain the same number of patterns of each length. We will sometimes talk about the type of an unbalanced Wilf-equivalence, defined by the lengths of the patterns: for example, the two Wilf-equivalences proved in this paper have types (4) ∼ (4,7) and (4,4) ∼ (4,4,6). In Section 1, we prove that {1324,3416725} ∼ 1234. In Section 2, we prove that {2143,3142,246135} ∼ {2413,3142}. In Section 3, we conjecture a few other unbalanced Wilf-equivalences.
The Neumann problem and Helmholtz decomposition in convex domains

We show that the Neumann problem for Laplace's equation in a convex domain Ω with boundary data in Lp(∂Ω) is uniquely solvable for 1<p<∞. As a consequence, we obtain the Helmholtz decomposition of vector fields in Lp(Ω,Rd).
A bridge between Sobolev and Escobar inequalities and beyond

Abstract The classical Sobolev and Escobar inequalities are embedded into the same one-parameter family of sharp trace-Sobolev inequalities on half-spaces. Equality cases are characterized for each inequality in this family by tweaking a well-known mass transportation argument and lead to a new comparison theorem for trace Sobolev inequalities. The case p = 2 corresponds to a family of variational problems on conformally flat metrics which was previously settled by Carlen and Loss with their method of competing symmetries. In this case minimizers interpolate between conformally flat spherical and hyperbolic geometries, passing through the Euclidean geometry defined by the fundamental solution of the Laplacian.
Generating Graphs with Symmetry

In the field of complex networks and graph theory, new results are typically tested on graphs generated by a variety of algorithms such as the Erdős-Renyi model or the Barabasi-Albert model. Unfortunately, most graph generating algorithms do not typically create graphs with symmetries, which have been shown to have an important role on the network dynamics. Here, we present an algorithm to generate graphs with prescribed symmetries. The algorithm can also be used to generate graphs with a prescribed equitable partition but possibly without any symmetry. We also use our graph generator to examine the recently raised question about the relation between the orbits of the automorphism group and a graph's minimal equitable partition.