cssi/SciSciGPT-SciSciNet huggingface dataset:
Misremembering pain: A memory blindness approach to adding a better end

How people remember feeling in the past informs future decisions; however, memory for past emotion is subject to a number of biases. Previous research on choice blindness has shown that people often fail to notice when they are exposed to misinformation about their own decisions, preferences, and memories. This type of misinformation can influence how they later remember past events. In the present study, we examined the memory blindness effect in a new domain: memory for pain. Participants (N = 269) underwent a cold-pressor task and rated how much pain, distress, and positive and negative affect they had experienced. Later, participants were shown their pain ratings and asked to explain them. Some of the participants were shown lower pain ratings than they had actually made. In a second session, participants recalled how painful the task had been and how much distress and positive and negative affect they remembered experiencing. The results indicated that the majority of participants who were exposed to misinformation failed to detect the manipulation, and subsequently remembered the task as being less painful. The participants in the misinformation condition were not overall more willing to repeat the study tasks, but the participants who recalled less distress, less negative affect, and more positive affect were more willing to repeat the study tasks again in a future experiment. These results demonstrate the malleability of memory for painful experiences and that willingness to repeat aversive experiences may depend more on memory for affective reactions to the original experience than on memory for the physical pain itself.
Convenient Interface to Inverse Ising (ConIII): A Python 3 Package for Solving Ising-Type Maximum Entropy Models

ConIII (pronounced CON-ee) is an open-source Python project providing a simple interface to solving the pairwise and higher order Ising model and a base for extension to other maximum entropy models. We describe the maximum entropy problem and give an overview of the algorithms that are implemented as part of ConIII ( https://github.com/eltrompetero/coniii ) including Monte Carlo histogram, pseudolikelihood, minimum probability flow, a regularized mean field method, and a cluster expansion method. Our goal is to make a variety of maximum entropy techniques accessible to those unfamiliar with the techniques and accelerate workflow for users. Funding Statement: EDL was supported by an NSF Graduate Fellowship under grant no. DGE-1650441. This research was supported in part by a congressional research grant provided by the Dirksen Congressional Center.
Diversifying Reply Suggestions using a Matching-Conditional Variational Autoencoder

We consider the problem of diversifying automated reply suggestions for a commercial instant-messaging (IM) system (Skype). Our conversation model is a standard matching based information retrieval architecture, which consists of two parallel encoders to project messages and replies into a common feature representation. During inference, we select replies from a fixed response set using nearest neighbors in the feature space. To diversify responses, we formulate the model as a generative latent variable model with Conditional Variational Auto-Encoder (M-CVAE). We propose a constrained-sampling approach to make the variational inference in M-CVAE efficient for our production system. In offline experiments, M-CVAE consistently increased diversity by ∼30−40% without significant impact on relevance. This translated to a ∼5% gain in click-rate in our online production system.
Chemical Potential of Nitrogen at High Pressure and High Temperature: Application to Nitrogen and Nitrogen-Rich Phase Diagram Calculations

The chemical potential change of nitrogen at high pressure/high temperature is a crucial ingredient for predicting the formation of nitrogen-rich compounds. Here, we provide intelligible data for t...
An empirical study of the economic effects of climate change on world agriculture

The economic effects of a doubling of atmospheric carbon dioxide concentration on world agriculture under two alternative crop response scenarios are empirically estimated. These effects include both changes in the prices of agricultural commodities as a result of changes in domestic agricultural yields, and changes in economic welfare following altered world patterns of consumption and production of agricultural commodities. Under both scenarios, with a few exceptions, the effects on national economic welfare are found to be quite modest. However, prices of agricultural commodities are estimated to rise considerably under the more pessimistic scenario. Increased agricultural prices reduce consumer surplus and diminish the benefits from climate change that some countries with predicted positive yield effects would otherwise receive.
Simultaneous Mapping of Coastal Topography and Bathymetry From a Lightweight Multicamera UAS

A low-cost multicamera Unmanned Aircraft System (UAS) is used to simultaneously estimate open-coast topography and bathymetry from a single longitudinal coastal flight. The UAS combines nadir and oblique imagery to create a wide field of view (FOV), which enables collection of mobile, long dwell timeseries of the littoral zone suitable for structure-from-motion (SfM), and wave speed inversion algorithms. Resultant digital surface models (DSMs) compare well with terrestrial topographic lidar and bathymetric survey data at Duck, NC, USA, with roor-mean-square error (RMSE)/bias of 0.26/–0.05 and 0.34/–0.05 m, respectively. Bathymetric data from another flight at Virginia Beach, VA, USA, demonstrates successful comparison (RMSE/bias of 0.17/0.06 m) in a secondary environment. UAS-derived engineering data products, total volume profiles and shoreline position, were congruent with those calculated from traditional topo-bathymetric surveys at Duck. Capturing both topography and bathymetry within a single flight, the presented multicamera system is more efficient than data acquisition with a single camera UAS; this advantage grows for longer stretches of coastline (10 km). Efficiency increases further with an on-board Global Navigation Satellite System–Inertial Navigation System (GNSS-INS) to eliminate ground control point (GCP) placement. The Appendix reprocesses the Virginia Beach flight with the GNSS–INS input and no GCPs. The resultant DSM products are comparable [root-mean-squared difference (RMSD)/bias of 0.62/−0.09 m, and processing time is significantly reduced.
Cyclobutenedione-Based Method for the Synthesis of Substituted 2-Pyridinones and Dihydro-2-pyridinones

1,2-Addition of N-Boc-protected α-amino carbanions to cyclobutenediones followed by methylation of the resulting alkoxides generated 4-(1-N-Boc-aminoalkyl)-4-methoxy-3-cyclobutenones. Removal of the Boc protecting group and thermal ring expansion gave dihydro-2-pyridinones in good yields. Treatment of the dihydro-2-pyridinones with NBS/pyridine led to the formation of the corresponding 2-pyridinones. This methodology proved general with regard to both the cyclobutenediones and α-amino carbanions.
Induced sensitivity of Bacillus subtilis colony morphology to mechanical media compression

Bacteria from several taxa, including Kurthia zopfii, Myxococcus xanthus, and Bacillus mycoides, have been reported to align growth of their colonies to small features on the surface of solid media, including anisotropies created by compression. While the function of this phenomenon is unclear, it may help organisms navigate on solid phases, such as soil. The origin of this behavior is also unknown: it may be biological (that is, dependent on components that sense the environment and regulate growth accordingly) or merely physical. Here we show that B. subtilis, an organism that typically does not respond to media compression, can be induced to do so with two simple and synergistic perturbations: a mutation that maintains cells in the swarming (chained) state, and the addition of EDTA to the growth media, which further increases chain length. EDTA apparently increases chain length by inducing defects in cell separation, as the treatment has only marginal effects on the length of individual cells. These results lead us to three conclusions. First, the wealth of genetic tools available to B. subtilis will provide a new, tractable chassis for engineering compression sensitive organisms. Second, the sensitivity of colony morphology to media compression in Bacillus can be modulated by altering a simple physical property of rod-shaped cells. And third, colony morphology under compression holds promise as a rapid, simple, and low-cost way to screen for changes in the length of rod-shaped cells or chains thereof.
Impact of Rapid Susceptibility Testing and Antibiotic Selection Strategy on the Emergence and Spread of Antibiotic Resistance in Gonorrhea

Background Increasing antibiotic resistance limits treatment options for gonorrhea. We examined the impact of a hypothetical point-of-care (POC) test reporting antibiotic susceptibility profiles on slowing resistance spread. Methods A mathematical model describing gonorrhea transmission incorporated resistance emergence probabilities and fitness costs associated with resistance based on characteristics of ciprofloxacin (A), azithromycin (B), and ceftriaxone (C). We evaluated time to 1% and 5% prevalence of resistant strains among all isolates with the following: (1) empiric treatment (B and C), and treatment guided by POC tests determining susceptibility to (2) A only and (3) all 3 antibiotics. Results Continued empiric treatment without POC testing was projected to result in >5% of isolates being resistant to both B and C within 15 years. Use of either POC test in 10% of identified cases delayed this by 5 years. The 3 antibiotic POC test delayed the time to reach 1% prevalence of triply-resistant strains by 6 years, whereas the A-only test resulted in no delay. Results were less sensitive to assumptions about fitness costs and test characteristics with increasing test uptake. Conclusions Rapid diagnostics reporting antibiotic susceptibility may extend the usefulness of existing antibiotics for gonorrhea treatment, but ongoing monitoring of resistance patterns will be critical.
Statistical assertions for validating patterns and finding bugs in quantum programs

In support of the growing interest in quantum computing experimentation, programmers need new tools to write quantum algorithms as program code. Compared to debugging classical programs, debugging quantum programs is difficult because programmers have limited ability to probe the internal states of quantum programs; those states are difficult to interpret even when observations exist; and programmers do not yet have guidelines for what to check for when building quantum programs. In this work, we present quantum program assertions based on statistical tests on classical observations. These allow programmers to decide if a quantum program state matches its expected value in one of classical, superposition, or entangled types of states. We extend an existing quantum programming language with the ability to specify quantum assertions, which our tool then checks in a quantum program simulator. We use these assertions to debug three benchmark quantum programs in factoring, search, and chemistry. We share what types of bugs are possible, and lay out a strategy for using quantum programming patterns to place assertions and prevent bugs.
The developing premature infant gut microbiome is a major factor shaping the microbiome of neonatal intensive care unit rooms

The neonatal intensive care unit (NICU) contains a unique cohort of patients with underdeveloped immune systems and nascent microbiome communities. Patients often spend several months in the same room, and it has been previously shown that the gut microbiomes of these infants often resemble the microbes found in the NICU. Little is known, however, about the identity, persistence, and absolute abundance of NICU room-associated bacteria over long stretches of time. Here, we couple droplet digital PCR (ddPCR), 16S rRNA gene surveys, and recently published metagenomics data from infant gut samples to infer the extent to which the NICU microbiome is shaped by its room occupants. Over 2832 swabs, wipes, and air samples were collected from 16 private-style NICU rooms housing very low birth weight (< 1500 g), premature (< 31 weeks’ gestation) infants. For each infant, room samples were collected daily, Monday through Friday, for 1 month. The first samples from the first infant and the last samples from the last infant were collected 383 days apart. Twenty-two NICU locations spanning room surfaces, hands, electronics, sink basins, and air were collected. Results point to an incredibly simple room community where 5–10 taxa, mostly skin-associated, account for over 50% of the amplicon reads. Biomass estimates reveal four to five orders of magnitude difference between the least to the most dense microbial communities, air, and sink basins, respectively. Biomass trends from bioaerosol samples and petri dish dust collectors suggest occupancy to be a main driver of suspended biological particles within the NICU. Using a machine learning algorithm to classify the origin of room samples, we show that each room has a unique microbial fingerprint. Several important taxa driving this model were dominant gut colonizers of infants housed within each room. Despite regular cleaning of hospital surfaces, bacterial biomass was detectable at varying densities. A room-specific microbiome signature was detected, suggesting microbes seeding NICU surfaces are sourced from reservoirs within the room and that these reservoirs contain actively dividing cells. Collectively, the data suggests that hospitalized infants, in combination with their caregivers, shape the microbiome of NICU rooms.
PREDICTD PaRallel Epigenomics Data Imputation with Cloud-based Tensor Decomposition.

The Encyclopedia of DNA Elements (ENCODE) and the Roadmap Epigenomics Project seek to characterize the epigenome in diverse cell types using assays that identify, for example, genomic regions with modified histones or accessible chromatin. These efforts have produced thousands of datasets but cannot possibly measure each epigenomic factor in all cell types. To address this, we present a method, PaRallel Epigenomics Data Imputation with Cloud-based Tensor Decomposition (PREDICTD), to computationally impute missing experiments. PREDICTD leverages an elegant model called “tensor decomposition” to impute many experiments simultaneously. Compared with the current state-of-the-art method, ChromImpute, PREDICTD produces lower overall mean squared error, and combining the two methods yields further improvement. We show that PREDICTD data captures enhancer activity at noncoding human accelerated regions. PREDICTD provides reference imputed data and open-source software for investigating new cell types, and demonstrates the utility of tensor decomposition and cloud computing, both promising technologies for bioinformatics. Assays to characterize the epigenome and interrogate chromatin state genome wide have so far been performed in a selected set of conditions. Here, Durham et al. develop a computational method based on tensor decomposition to impute missing experiments in collections of epigenomics experiments.
LMethyR-SVM: Predict Human Enhancers Using Low Methylated Regions based on Weighted Support Vector Machines.

Background The identification of enhancers is a challenging task. Various types of epigenetic information including histone modification have been utilized in the construction of enhancer prediction models based on a diverse panel of machine learning schemes. However, DNA methylation profiles generated from the whole genome bisulfite sequencing (WGBS) have not been fully explored for their potential in enhancer prediction despite the fact that low methylated regions (LMRs) have been implied to be distal active regulatory regions. Method In this work, we propose a prediction framework, LMethyR-SVM, using LMRs identified from cell-type-specific WGBS DNA methylation profiles and a weighted support vector machine learning framework. In LMethyR-SVM, the set of cell-type-specific LMRs is further divided into three sets: reliable positive, like positive and likely negative, according to their resemblance to a small set of experimentally validated enhancers in the VISTA database based on an estimated non-parametric density distribution. Then, the prediction model is obtained by solving a weighted support vector machine. Results We demonstrate the performance of LMethyR-SVM by using the WGBS DNA methylation profiles derived from the human embryonic stem cell type (H1) and the fetal lung fibroblast cell type (IMR90). The predicted enhancers are highly conserved with a reasonable validation rate based on a set of commonly used positive markers including transcription factors, p300 binding and DNase-I hypersensitive sites. In addition, we show evidence that the large fraction of the LMethyR-SVM predicted enhancers are not predicted by ChromHMM in H1 cell type and they are more enriched for the FANTOM5 enhancers. Conclusion Our work suggests that low methylated regions detected from the WGBS data are useful as complementary resources to histone modification marks in developing models for the prediction of cell-type-specific enhancers.
The trimethylsilyl xylyl (TIX) ether: a useful protecting group for alcohols

A new protecting group for alcohols, the p-trimethylsilyl xylyl (TIX) group has been developed. The TIX group is used to protect various alcohols under acidic as well as basic conditions. The protected ethers thus formed had noteworthy chemoselectivity upon deprotection in the presence of other benzyl ethers and commonly used protecting groups. The stability of the TIX group towards various reagents has also been examined.
Tuning of Vinylborane Dienophilicity. Optimization of Reactivity, Regioselectivity, endo-Stereoselectivity, and Reagent Stability

Abstract Simple syntheses of some vinylboranes are reported, and their properties in Diels-Alder reactions are compared. Vinyl-3,6-dimethylborepane was the most stable simple vinylborane examined, and appears to be indefinitely stable at 25°C. Surprisingly, trivinylborane is the most reactive, and reacts about 18 times faster than the vinyldialkylboranes with cyclopentadiene. Vinyl-9-BBN is the most regioselective dienophile, in keeping with principally steric control of regioselectivity in Diels-Alder reactions of vinylboranes. All the dienophiles display high endo-stereoselectivity with piperylene, but vinyl-3,6-dimethylborepane displays significantly improved stereoselectivity with cyclopentadiene. In general, by choice of alkyl-substituents on boron, the reactivity, regioselectivity, endo-stereoselectivity, and stability of vinylboranes can be optimized.
Kinetics and Mechanisms of Aqueous Ozone Reactions with Bromide, Sulfite, Hydrogen Sulfite, Iodide, and Nitrite Ions

Reactions of ozone with Br-, SO32-, HSO3-, I-, and NO2-, studied by stopped-flow and pulsed-accelerated-flow techniques, are first order in the concentration of O3(aq) and first order in the concentration of each anion. The rate constants increase by a factor of 5 × 106 as the nucleophilicities of the anions increase from Br- to SO32-. Ozone adducts with the nucleophiles are proposed as steady-state intermediates prior to oxygen atom transfer with release of O2. Ab initio calculations show possible structures for the intermediates. The reaction between Br- and O3 is accelerated by H+ but exhibits a kinetic saturation effect as the acidity increases. The kinetics indicate formation of BrOOO- as a steady-state intermediate with an acid-assisted step to give BrOH and O2. Temperature dependencies of the reactions of Br- and HSO3- with O3 in acidic solutions are determined from 1 to 25 °C. These kinetics are important in studies of annual ozone depletion in the Arctic troposphere at polar sunrise.
Defining the core essential genome of Pseudomonas aeruginosa.

Genomics offered the promise of transforming antibiotic discovery by revealing many new essential genes as good targets, but the results fell short of the promise. While numerous factors contributed to the disappointing yield, one factor was that essential genes for a bacterial species were often defined based on a single or limited number of strains grown under a single or limited number of in vitro laboratory conditions. In fact, the essentiality of a gene can depend on both the genetic background and growth condition. We thus developed a strategy for more rigorously defining the core essential genome of a bacterial species by studying many pathogen strains and growth conditions. We assessed how many strains must be examined to converge on a set of core essential genes for a species. We used transposon insertion sequencing (Tn-Seq) to define essential genes in nine strains of Pseudomonas aeruginosa on five different media and developed a statistical model, FiTnEss, to classify genes as essential versus nonessential across all strain–medium combinations. We defined a set of 321 core essential genes, representing 6.6% of the genome. We determined that analysis of four strains was typically sufficient in P. aeruginosa to converge on a set of core essential genes likely to be essential across the species across a wide range of conditions relevant to in vivo infection, and thus to represent attractive targets for novel drug discovery.
Applications of deuterium isotope effects for probing aspects of reactions involving oxidative addition and reductive elimination of H-H and C-H bonds

The various types of deuterium isotope effects that are observed for reactions involving oxidative addition and reductive elimination reactions of H–H and C–H bonds with a transition metal center are reviewed. Copyright © 2007 John Wiley & Sons, Ltd.
Familiarity modulates social approach toward stressed conspecifics in female rats.

Familiarity between conspecifics may influence how social affective cues shape social behaviors. In a social affective preference test, experimental rats, when given the choice to explore an unfamiliar stressed or a naive adult, will avoid interaction with a stressed conspecific. To determine if familiarity would influence social interactions with stressed conspecifics, male and female test rats underwent 2 social affective preference tests in isosexual triads where an experimental rat was presented with a naive and a stressed target conspecific who were either familiar (cagemate) or unfamiliar. Male and female experimental rats avoided stressed unfamiliar conspecifics. However, experimental female rats demonstrated a preference to interact with their stressed, familiar cagemates. Male and female rats exhibited more self-grooming and immobility behavior in the presence of stressed conspecifics, which may indicate emotion contagion. These findings suggest a sex-specific role of familiarity in social approach and avoidance, and warrant further mechanistic exploration.
Stereospecific Entry to [4.5]Spiroketal Glycosides Using Alkylidenecarbene C−H Insertion

A novel method for the stereospecific preparation of [4.5]spiroketal glycosides utilizing the 1,5 C−H bond insertion of alkylidenecarbenes is described. Treatment of 2-oxopropyl β-pyranosides A wit...
One-pot synthesis of 2-substituted furo[3,2-c]quinolines via tandem coupling–cyclization under Pd/C-copper catalysis

Abstract Pd/C–Cu catalyzed coupling reactions of 3-iodo-1 H -quinolin-4-ones with a variety of terminal alkynes afforded furo[3,2- c ]quinolines regioselectively in good to excellent yields. 3-Alkynyl quinolones were isolated under the same reaction conditions when the nitrogen of 3-iodo-1 H -quinolin-4-one was substituted with an alkyl group.
Synthesis of 4′-substituted 2,2′:6′,2″-terpyridines via a Mitsunobu reaction

Abstract Treatment of 2,6-di(pyridin-2-yl)pyridin-4(1H)-one with various appropriately protected ω-substituted primary alcohols or a nucleoside (3,3′-O-diBz-dUrd) in dry THF in the presence of triphenylphosphine and diisopropylazodicarboxylate gives the corresponding 4′-substituted terpyridines in high yield.
Synthesis of (−)-7-Epiaustraline and (−)-1-Epicastanospermine

Highly efficient and selective syntheses of the title compounds are described. The cornerstone of the synthetic plan is the tandem inter [4 + 2]/inter [3 + 2] cycloaddition process. These syntheses differ from previous applications of this strategy in that they incorporate an alkylation in the hydrogenolysis step to close the second ring of the azabicyclic systems. Notable features of the sequence are (1) the highly regio- and stereoselective [3 + 2] cycloaddition of nitronate 15 with siloxymethyl (Z)-β-silylvinyl ketone (Z)-22b and (2) the highly selective reduction of the resulting ketone 24a with L-Selectride. A single-crystal X-ray structure analysis of synthetic (−)-7-epiaustraline confirmed that the targeted structure was successfully synthesized. This stimulated a reexamination of the structural assignment of the natural product. (−)-1-Epicastanospermine was synthesized in four steps from the common intermediate 27a. The absolute configuration of (−)-1-epicastanospermine was assured by single-cryst...
Fullerene oxides and ozonides

Abstract Oxygen adducts were among the first reported fullerene derivatives, and they have continued to be the subject of many subsequent investigations by experimental and theoretical researchers. A literature survey is presented summarizing the preparation, purification, characterization, and stabilities of fullerene oxides and ozonides. Published data on the 13C NMR spectra, thermal dissociation reaction products and kinetics, and photolysis products of these compounds are compiled and presented in tabular form. To cite this article: D. Heymann and R.B. Weisman, C. R. Chimie 9 (2006).
Novel 3',5'-cyclic nucleotide analogue: adenosine 3',5'-cyclic boranomonophosphate.

A general procedure for the first synthesis of a 3‘,5‘-cyclic boranomonophosphate was established. Specifically, adenosine 3‘,5‘-cyclic boranomonophosphosphate (cyclic AMPB, 4c), a P-borane (BH3) analogue of adenosine 3‘,5‘-cyclic monophosphate (cAMP), was synthesized via a phosphite approach in good yield. The method is also applicable for syntheses of natural cAMP and its phosphorothioate analogue. The two diasteromers of cyclic AMPB 4c were separated, and their chemical structures were established via spectroscopic methods.
Consecutive carbon-carbon bond formation via the π-allylpalladium variant of the Heck reaction

Abstract Two CC bonds are readily formed by nucleophilic addition of stabilized carbanions to the π-allylpalladium intermediate regioselectively produced by the Heck reaction of a vinyl bromide and an unactivated olefin. An intramolecular version of this condensation gives functionalized carbobicyclic compounds as products.
Optimality of linear sketching under modular updates

We study the relation between streaming algorithms and linear sketching algorithms, in the context of binary updates. We show that for inputs in n dimensions, the existence of efficient streaming algorithms which can process Ω(n2) updates implies efficient linear sketching algorithms with comparable cost. This improves upon the previous work of Li, Nguyen and Woodruff [23] and Ai, Hu, Li and Woodruff [3] which required a triple-exponential number of updates to achieve a similar result for updates over integers. We extend our results to updates modulo p for integers p ≥ 2, and to approximation instead of exact computation.
Mechanistic Basis for Decreased Antimicrobial Susceptibility in a Clinical Isolate of Neisseria gonorrhoeae Possessing a Mosaic-Like mtr Efflux Pump Locus.

ABSTRACT Recent reports suggest that mosaic-like sequences within the mtr (multiple transferable resistance) efflux pump locus of Neisseria gonorrhoeae, likely originating from commensal Neisseria sp. by transformation, can increase the ability of gonococci to resist structurally diverse antimicrobials. Thus, acquisition of numerous nucleotide changes within the mtrR gene encoding the transcriptional repressor (MtrR) of the mtrCDE efflux pump-encoding operon or overlapping promoter region for both along with those that cause amino acid changes in the MtrD transporter protein were recently reported to decrease gonococcal susceptibility to numerous antimicrobials, including azithromycin (Azi) (C. B. Wadsworth, B. J. Arnold, M. R. A. Satar, and Y. H. Grad, mBio 9:e01419-18, 2018, https://doi.org/10.1128/mBio.01419-18). We performed detailed genetic and molecular studies to define the mechanistic basis for why such strains can exhibit decreased susceptibility to MtrCDE antimicrobial substrates, including Azi. We report that a strong cis-acting transcriptional impact of a single nucleotide change within the −35 hexamer of the mtrCDE promoter as well gain-of-function amino acid changes at the C-terminal region of MtrD can mechanistically account for the decreased antimicrobial susceptibility of gonococci with a mosaic-like mtr locus. IMPORTANCE Historically, after introduction of an antibiotic for treatment of gonorrhea, strains of N. gonorrhoeae emerge that display clinical resistance due to spontaneous mutation or acquisition of resistance genes. Genetic exchange between members of the Neisseria genus occurring by transformation can cause significant changes in gonococci that impact the structure of an antibiotic target or expression of genes involved in resistance. The results presented here provide a framework for understanding how mosaic-like DNA sequences from commensal Neisseria that recombine within the gonococcal mtr efflux pump locus function to decrease bacterial susceptibility to antimicrobials, including antibiotics used in therapy of gonorrhea.
Cobalt(II) chloride catalyzed syntheses of acid anhydrides from acid chlorides

Abstract Acid anhydrides were synthesized by reacting acid chlorides with car☐ylic acids in the presence of catalytic quantities of cobalt(II) chloride.
Fluoro-β-lactams: Synthesis and application in asymmetric synthesis

Publisher Summary The incorporation of fluorine atom into organic molecules results in drastic changes of their properties. Especially, fluorinated natural products are of great interest because of their enhanced biological activity. Among them fluoro-β-lactams became new targets because they are proved to be effective β-lactamase and human leukocyte elastase inhibitors. This chapter reviews the fluorinated penicillins and cephalosporins and their biological activity are described as well. The chapter focuses on synthesis of the β-lactams with fluorine atom in the ring and transformations on fluoro-β-lactam molecules leading to another fluorinated material. This approach, known as the “β-Lactam Method,” has been successfully used in the synthesis of aminoacids and sugars. The fluorination of the β-lactam ring and construction of the β-lactam molecule from fluorinated building blocks represent two strategies used for the preparation of fluoroazetidinones. The fluorination procedure is thoroughly reviewed. The most frequently used fluorination agents are diethylaminosulfur trifluoride (DAST), tetrabutylammonium dihydrogen trifluoride, and pyridinium polyhydrogen fluoride.
The Solid-State Polymerization of 3,5-Dihalo-4-aminobenzoylchlorides: New Structural Perspectives

Abstract Heating 3,5-dihalo-4-aminobenzoylchlorides affords the analogous solid polybenzamides. X-Ray structure determinations of 3,5-dichloro-, 3,5-dibromo- and 3,5-diiodo-4-aminobenzoylchlorides reveal that all three structures contain infinite hydrogen-bonded chains of monomers in a head-to-tail arrangement (graph set notation C(8)), with amine-to-carbonyl carbon atom distances
Diastereoselective synthesis of pyrroloindolines using α,β-unsaturated N-aryl ketonitrones and activated alkynes

Abstract A synthetic method has been developed for diastereoselective de novo synthesis of pyrroloindolines using readily available α,β-unsaturated N-aryl ketonitrones and amino acid derived activated alkynes. The reaction likely proceeded by initial formation of C3-quaternary indolenines followed by N-cyclization of the pendent nitrogen atom to give the complex heterocyclic system from simple starting materials in one step. Pyrroloindolines with substituents that may be difficult to introduce via other approaches have been prepared using this method.
Molten Ga as a Solvent for Exploratory Synthesis: The New Ternary Polygallide Sm2NiGa12

Molten Ga is an excellent solvent for the preparation of the polygallide Sm2NiGa12. The compound is metallic and adopts an unusual three-dimensional structure composed of two different kinds of alternating segments. One segment has Ni and Ga atoms and is reminiscent of the KCu4S3 structure type. The other has only Ga atoms and adopts an elaborate Ga network.
Species- And C-terminal linker-dependent variations in the dynamic behavior of FtsZ on membranes in vitro

Bacterial cell division requires the assembly of FtsZ protofilaments into a dynamic structure called the 'Z-ring'. The Z-ring recruits the division machinery and directs local cell wall remodeling for constriction. The organization and dynamics of protofilaments within the Z-ring coordinate local cell wall synthesis during cell constriction, but their regulation is largely unknown. The disordered C-terminal linker (CTL) region of Caulobacter crescentus FtsZ (CcFtsZ) regulates polymer structure and turnover in solution in vitro, and regulates Z-ring structure and activity of cell wall enzymes in vivo. To investigate the contributions of the CTL to the polymerization properties of FtsZ on its physiological platform, the cell membrane, we reconstituted CcFtsZ polymerization on supported lipid bilayers (SLB) and visualized polymer dynamics and structure using total internal reflection fluorescence microscopy. Unlike Escherichia coli FtsZ protofilaments that organized into large, bundled patterns, CcFtsZ protofilaments assembled into small, dynamic clusters on SLBs. Moreover, CcFtsZ lacking its CTL formed large networks of straight filament bundles that underwent slower turnover than the dynamic clusters of wildtype FtsZ. Our in vitro characterization provides novel insights into species- and CTL-dependent differences between FtsZ assembly properties that are relevant to Z-ring assembly and function on membranes in vivo.
The aluminum amalgam reduction of 2-nitroalkanols promoted by ultrasound

Abstract The sonochemical promoted aluminum amalgam reduction of 2-nitroalkanols provides an improved yield and accelerated conversion to the corresponding amino alcohols when compared to the nonultrasound (benchtop) reductions. The appearance of by-product hydroxylamines is minimized during the ultrasound promoted reaction. The product amino alcohols were conveniently acylated in situ with promotion by ultrasound thus affording the N-acyl derivatives in the same operation.
Silver(I)-Catalyzed Addition of Zirconocenes to Epoxy Esters: A New Entry to 1,4-Dicarbonyl Compounds and Pyridazinones

The Ag(I)-catalyzed tandem epoxy ester rearrangement−dioxycarbenium ion addition reaction with alkenyl zirconocenes provides 1,4-keto esters that can be further converted to substituted pyridazinones. The use of a fluorous tag in a cyclization-assisted cleavage strategy demonstrates the feasibility of extending this methodology to high-throughput organic synthesis.
Early ictal recruitment of midline thalamus in mesial temporal lobe epilepsy.

The causal role of midline thalamus in the initiation and early organization of mesial temporal lobe seizures is studied. Three patients undergoing stereoelectroencephalography were enrolled for the placement of an additional depth electrode targeting the midline thalamus. The midline thalamus was recruited in all three patients at varying points of seizure initiation (0-13 sec) and propagation (9-60 sec). Stimulation of either thalamus or hippocampus induced similar habitual seizures. Seizure-induced in the hippocampus rapidly recruited the thalamus. Evoked potentials demonstrated stronger connectivity from the hippocampus to the thalamus than in the opposite direction. The midline thalamus can be within the seizure initiation and symptomatogenic circuits.
The Political Economy of Redistributive Social Security

Population aging puts significant pressure on social security systems that are based mainly on a pay-as-you-go (PAYG) formula and determined by the political process in which both retirees and future retirees participate. This paper demonstrates that in an economic and demographic steady state, majoritarian democracy overspends on social security. It then shows that in case of demographic shock, the regular majority process can be paralyzed by the development of entrenched interest groups that could lose from majority decisions. Depending on the way these entrenched interests operate, they can be judged more or less desirable from the viewpoint of social justice.
The empirical likelihood approach to quantifying uncertainty in sample average approximation

Abstract We study the empirical likelihood approach to construct confidence intervals for the optimal value and the optimality gap of a given solution, henceforth quantify the statistical uncertainty of sample average approximation, for optimization problems with expected value objectives and constraints where the underlying probability distributions are observed via limited data. This approach relies on two distributionally robust optimization problems posited over the uncertain distribution, with a divergence-based uncertainty set that is suitably calibrated to provide asymptotic statistical guarantees.
On Conway mutation and link homology

Abstract We give a new, elementary proof that Khovanov homology with Z / 2 Z –coefficients is invariant under Conway mutation. This proof also gives a strategy to prove Baldwin and Levine's conjecture that δ–graded knot Floer homology is mutation–invariant. Using the Clifford module structure on HFK ˜ induced by basepoint maps, we carry out this strategy for mutations on a large class of tangles. Let L ′ be a link obtained from L by mutating the tangle T. Suppose some rational closure of T corresponding to the mutation is the unlink on any number of components. Then L and L ′ have isomorphic δ–graded HFK ˆ groups over Z / 2 Z as well as isomorphic Khovanov homology over Q . We apply these results to establish mutation–invariance for the infinite families of Kinoshita-Terasaka and Conway knots. Finally, we give sufficient conditions for a general Khovanov-Floer theory to be mutation–invariant.
GRADED SUPER DUALITY FOR GENERAL LINEAR LIE SUPERALGEBRAS

We provide a new proof of the super duality equivalence between infinite-rank parabolic BGG categories of general linear Lie (super) algebras conjectured by Cheng and Wang and first proved by Cheng and Lam. We do this by establishing a new uniqueness theorem for tensor product categorifications motivated by work of Brundan, Losev, and Webster. Moreover we show that these BGG categories have Koszul graded lifts and super duality can be lifted to a graded equivalence.
Khovanov homology and knot Floer homology for pointed links

A well-known conjecture states that for any l-component link L in S3, the rank of the knot Floer homology of L (over any field) is less than or equal to 2l−1 times the rank of the reduced Khovanov homology of L. In this paper, we describe a framework that might be used to prove this conjecture. We construct a modified version of Khovanov homology for links with multiple basepoints and show that it mimics the behavior of knot Floer homology. We also introduce a new spectral sequence converging to knot Floer homology whose E1 page is conjecturally isomorphic to our new version of Khovanov homology; this would prove that the conjecture stated above holds over the field ℤ2.
A new family of links topologically, but not smoothly, concordant to the Hopf link

We give new examples of 2-component links with linking number one and unknotted components that are topologically concordant to the positive Hopf link, but not smoothly so – in addition, they are not smoothly concordant to the positive Hopf link with a knot tied in the first component. Such examples were previously constructed by Cha–Kim–Ruberman–Strle; we show that our examples are distinct in smooth concordance from theirs.
Temporal Hierarchical Clustering

We study hierarchical clusterings of metric spaces that change over time. This is a natural geometric primitive for the analysis of dynamic data sets. Specifically, we introduce and study the problem of finding a temporally coherent sequence of hierarchical clusterings from a sequence of unlabeled point sets. We encode the clustering objective by embedding each point set into an ultrametric space, which naturally induces a hierarchical clustering of the set of points. We enforce temporal coherence among the embeddings by finding correspondences between successive pairs of ultrametric spaces which exhibit small distortion in the Gromov-Hausdorff sense. We present both upper and lower bounds on the approximability of the resulting optimization problems.
A Nonlinear Stationary Phase Method for Oscillatory Riemann–Hilbert Problems

We study the asymptotic behavior of oscillatory Riemann–Hilbert problems (RHPs) arising in the Ablowitz-Kaup-Newell-Segur hierarchy of integrable nonlinear partial differential equations. Our method is based on the Deift–Zhou nonlinear steepest descent method in which the given RHP localizes to small neighborhoods of stationary phase points. In their original work, Deift and Zhou only considered analytic phase functions. Subsequently, Varzugin extended the Deift–Zhou method to a certain restricted class of nonanalytic phase functions. In this paper, we extend Varzugin’s method to a substantially more general class of nonanalytic phase functions. In our work, real variable methods play a key role.
A New Approach to Analyzing Robin Hood Hashing

Robin Hood hashing is a variation on open addressing hashing designed to reduce the maximum search time as well as the variance in the search time for elements in the hash table. While the case of insertions only using Robin Hood hashing is well understood, the behavior with deletions has remained open. Here we show that Robin Hood hashing with random hash functions can be analyzed under the framework of finite-level finitedimensional jump Markov chains. This framework allows us to re-derive some past results for the insertiononly case with some new insight, as well as provide new analyses for a standard deletion model, where we alternate between deleting a random old key and inserting a new one.
A complete complex hypersurface in the ball of C^N

In 1977, P. Yang asked whether there exist complete immersed complex submanifolds ’: M k ! C N with bounded image. A positive answer is known for holomorphic curves (k = 1) and partial answers are known for the case when k > 1. The principal result of the present paper is a construction of a holomorphic function on the open unit ball BN of C N whose real part is unbounded on every path in BN of nite length that ends on bBN . A consequence is the existence of a complete, closed complex hypersurface in BN . This gives a positive answer to Yang’s question in all dimensions k; N; 1 k < N, by providing properly embedded complete complex manifolds.
Topological protection of perturbed edge states

This paper proposes a quantitative description of the low energy edge states at the interface between two-dimensional topological insulators. They are modeled by continuous Hamiltonians as systems of Dirac equations that are amenable to a large class of random perturbations. We consider general as well as fermionic time reversal symmetric models. In the former case, Hamiltonians are classified using the index of a Fredholm operator. In the latter case, the classification involves a ${\mathbb Z}_2$ index. These indices dictate the number of topologically protected edge states. A remarkable feature of topological insulators is the asymmetry (chirality) of the edge states, with more modes propagating, say, up than down. In some cases, backscattering off imperfections is prevented when no mode can carry signals backwards. This is a desirable feature from an engineering perspective, which raises the question of how back-scattering is protected topologically. A major motivation for the derivation of continuous models is to answer such a question. We quantify how backscattering is affected but not suppressed by the non-trivial topology by introducing a scattering problem along the edge and describing the effects of topology and randomness on the scattering matrix. Explicit macroscopic models are then obtained within the diffusion approximation of field propagation to show the following: the combination of topology and randomness results in un-hindered transport of the protected modes while all other modes (Anderson) localize.
Optimization and testing in linear non‐Gaussian component analysis

Independent component analysis (ICA) decomposes multivariate data into mutually independent components (ICs). The ICA model is subject to a constraint that at most one of these components is Gaussian, which is required for model identifiability. Linear non-Gaussian component analysis (LNGCA) generalizes the ICA model to a linear latent factor model with any number of both non-Gaussian components (signals) and Gaussian components (noise), where observations are linear combinations of independent components. Although the individual Gaussian components are not identifiable, the Gaussian subspace is identifiable. We introduce an estimator along with its optimization approach in which non-Gaussian and Gaussian components are estimated simultaneously, maximizing the discrepancy of each non-Gaussian component from Gaussianity while minimizing the discrepancy of each Gaussian component from Gaussianity. When the number of non-Gaussian components is unknown, we develop a statistical test to determine it based on resampling and the discrepancy of estimated components. Through a variety of simulation studies, we demonstrate the improvements of our estimator over competing estimators, and we illustrate the effectiveness of the test to determine the number of non-Gaussian components. Further, we apply our method to real data examples and demonstrate its practical value.
On Geometric Prototype and Applications

In this paper, we propose to study a new geometric optimization problem called the "geometric prototype" in Euclidean space. Given a set of patterns, where each pattern is represented by a (weighted or unweighted) point set, the geometric prototype can be viewed as the "average pattern" minimizing the total matching cost to them. As a general model, the problem finds many applications in real-world, such as Wasserstein barycenter and ensemble clustering. The dimensionality could be either constant or high, depending on the applications. To our best knowledge, the general geometric prototype problem has yet to be seriously considered by the theory community. To bridge the gap between theory and practice, we first show that a small core-set can be obtained to substantially reduce the data size. Consequently, any existing heuristic or algorithm can run on the core-set to achieve a great improvement on the efficiency. As a new application of core-set, it needs to tackle a couple of challenges particularly in theory. Finally, we test our method on both image and high dimensional clustering datasets; the experimental results remain stable even if we run the algorithms on core-sets much smaller than the original datasets, while the running times are reduced significantly.
Residual automorphic forms and spherical unitary representations of exceptional groups

Arthur has conjectured that the unitarity of a number of representations can be shown by nding appropriate automorphic realizations. This has been veried for classical groups by Mglin and for the exceptional Chevalley group G2 by Kim. In this paper we extend their results on spherical representations to the remaining exceptional groups E6, E7, E8, and F4. In particular, we prove Arthur’s conjecture that the spherical constituent of an unramied principal series of a Chevalley group over any local eld of characteristic zero is unitarizable if its Langlands parameter coincides with half the weighted marking of a coadjoint nilpotent orbit of the Langlands dual Lie algebra.