cssi/SciSciGPT-SciSciNet huggingface dataset:
Superior vena cava syndrome in a patient with locally advanced lung cancer with good response to definitive chemoradiation: a case report.

The incidence of superior vena cava syndrome within the United States is roughly 15,000 cases per year. Superior vena cava syndrome is a potentially life-threatening medical condition; however, superior vena cava syndrome is not fatal in the majority of cases. Superior vena cava syndrome encompasses a collection of signs and symptoms resulting from obstruction of the superior vena cava, including swelling of the upper body of the head, neck, arms, and/or breast. It is also associated with cyanosis, plethora, and distended subcutaneous vessels. Lung cancer, including both non-small cell lung cancer and small cell lung cancer, is the most common extrinsic cause of superior vena cava syndrome. Intrinsic disruption of superior vena cava flow can also precipitate superior vena cava syndrome. This case report describes an unusual presentation and potential etiology of superior vena cava syndrome. Our patient was a 51-year-old black woman with locally advanced, stage IIIB non-small cell lung cancer who had no clinical symptoms of superior vena cava syndrome at the time of diagnosis. However, she did have radiographic evidence of superior vena cava stenosis caused by extrinsic compression from her large right hilar primary tumor. She was treated with definitive chemoradiation, receiving 60 Gy of external beam radiation therapy given concurrently with chemotherapy. Three months after completion of radiotherapy, she developed signs of superior vena cava syndrome, including breast and supraclavicular swelling. She had a chest computed tomography scan showing over 50% reduction in the size of a right hilar mass; however, she had continued radiographic stenosis of the superior vena cava. The distribution of stenosis appeared to be inferior to the caudal extent of pretreatment tumor volume. She had no other radiographic indications for superior vena cava syndrome. Generally, superior vena cava syndrome is the result of extrinsic compression of the superior vena cava by tumor. Our patient’s case represents the development of superior vena cava syndrome after an excellent response of tumor with near-complete tumor response. We suspect chemoradiation therapy as a potential etiology for the precipitation of the superior vena cava syndrome, which is currently not well reported in the medical literature.
Computer Model Calibration Based on Image Warping Metrics: An Application for Sea Ice Deformation

Arctic sea ice plays an important role in the global climate. Sea ice models governed by physical equations have been used to simulate the state of the ice including characteristics such as ice thickness, concentration, and motion. More recent models also attempt to capture features such as fractures or leads in the ice. These simulated features can be partially misaligned or misshapen when compared to observational data, whether due to numerical approximation or incomplete physics. In order to make realistic forecasts and improve understanding of the underlying processes, it is necessary to calibrate the numerical model to field data. Traditional calibration methods based on generalized least-square metrics are flawed for linear features such as sea ice cracks. We develop a statistical emulation and calibration framework that accounts for feature misalignment and misshapenness, which involves optimally aligning model output with observed features using cutting-edge image registration techniques. This work can also have application to other physical models which produce coherent structures. Supplementary materials accompanying this paper appear online.
Preexisting Simian Immunodeficiency Virus Infection Increases Susceptibility to Tuberculosis in Mauritian Cynomolgus Macaques.

ABSTRACT Tuberculosis (TB), caused by Mycobacterium tuberculosis, is the leading cause of death among human immunodeficiency virus (HIV)-positive patients. The precise mechanisms by which HIV impairs host resistance to a subsequent M. tuberculosis infection are unknown. We modeled this coinfection in Mauritian cynomolgus macaques (MCM) using simian immunodeficiency virus (SIV) as an HIV surrogate. We infected seven MCM with SIVmac239 intrarectally and 6 months later coinfected them via bronchoscope with ∼10 CFU of M. tuberculosis. Another eight MCM were infected with M. tuberculosis alone. TB progression was monitored by clinical parameters, by culturing bacilli in gastric and bronchoalveolar lavages, and by serial [18F]fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging. The eight MCM infected with M. tuberculosis alone displayed dichotomous susceptibility to TB, with four animals reaching humane endpoint within 13 weeks and four animals surviving >19 weeks after M. tuberculosis infection. In stark contrast, all seven SIV+ animals exhibited rapidly progressive TB following coinfection and all reached humane endpoint by 13 weeks. Serial PET/CT imaging confirmed dichotomous outcomes in MCM infected with M. tuberculosis alone and marked susceptibility to TB in all SIV+ MCM. Notably, imaging revealed a significant increase in TB granulomas between 4 and 8 weeks after M. tuberculosis infection in SIV+ but not in SIV-naive MCM and implies that SIV impairs the ability of animals to contain M. tuberculosis dissemination. At necropsy, animals with preexisting SIV infection had more overall pathology, increased bacterial loads, and a trend towards more extrapulmonary disease than animals infected with M. tuberculosis alone. We thus developed a tractable MCM model in which to study SIV-M. tuberculosis coinfection and demonstrate that preexisting SIV dramatically diminishes the ability to control M. tuberculosis coinfection.
An equivalence class for orthogonal vectors

The Orthogonal Vectors problem (OV) asks: given n vectors in {0,1}O(log n), are two of them orthogonal? OV is easily solved in O(n2 log n) time, and it is a central problem in finegrained complexity: dozens of conditional lower bounds are based on the popular hypothesis that OV cannot be solved in (say) n1.99 time. However, unlike the APSP problem, few other problems are known to be non-trivially equivalent to OV.We show OV is truly-subquadratic equivalent to several fundamental problems, all of which (a priori) look harder than OV. A partial list is given below:1. (Min-IP/Max-IP) Find a red-blue pair of vectors with minimum (respectively, maximum) inner product, among n vectors in {0,1}O(log n).2. (Exact-IP) Find a red-blue pair of vectors with inner product equal to a given target integer, among n vectors in {0, 1}O(log n).3. (Apx-Min-IP/Apx-Max-IP) Find a red-blue pair of vectors that is a 100-approximation to the minimum (resp. maximum) inner product, among n vectors in {0, 1}O(log n).4. (Approximate Bichrom.-lp-Closest-Pair) Compute a (1+ Ω(1))-approximation to the lp-closest red-blue pair (for a constant pe [1, 2]), among n points in Rd, d≤no(1).5. (Approximate lp-Furthest-Pair) Compute a (1 + Ω(1))-approximation to the lp-furthest pair (for a constant pe [1, 2]), among n points in Rd, d≤no(1).Therefore, quick constant-factor approximations to maximum inner product imply quick exact solutions to maximum inner product, in the O(log n)-dimensional setting. Another consequence is that the ability to find vectors with zero inner product suffices for finding vectors with maximum inner product.Our equivalence results are robust enough that they continue to hold in the data structure setting. In particular, we show that there is a poly(n) space, n1-e query time data structure for Partial Match with vectors from {0,1}O(log n) if and only if such a data structure exists for 1 + Ω(1) Approximate Nearest Neighbor Search in Euclidean space.To establish the equivalences, we introduce two general frameworks for reductions to OV: one based on ∑2 communication protocols, and another based on locality-sensitive hashing families.In addition, we obtain an n2-1/O(log c) time algorithm for Apx-Min-IP with n vectors from {0, 1}c log n, matching state-of-the-art algorithms for OV and Apx-Max-IP. As an application, we obtain a faster algorithm for approximating "almost solvable" MAX-SAT instances.
Improving Management with Individual and Group-Based Consulting : Results from a Randomized Experiment in Colombia

Differences in management quality are an important contributor to productivity differences across countries. A key question is how to best improve poor management in developing countries. This paper tests two different approaches to improving management in Colombian auto parts firms. The first uses intensive and expensive one-on-one consulting, while the second draws on agricultural extension approaches to provide consulting to small groups of firms at approximately one-third of the cost of the individual approach. Both approaches lead to improvements in management practices of a similar magnitude (8-10 percentage points), so that the new group-based approach dominates on a cost-benefit basis. Moreover, the paper finds some evidence that the group-based intervention led to increases in firm size over the next three years, while the impacts on firm outcomes are smaller and statistically insignificant for the individual consulting. The results point to the potential of group-based approaches as a pathway to scaling up management improvements.
A Tangled Web: Should Online Review Portals Display Fraudulent Reviews?

Consumers rely on review platforms when deciding where to stay, where to eat, what movies to watch, or even which doctor to use. This is great for consumers, but it has makes online review platform...
An overview of methodologies for cybersecurity vulnerability assessments conducted in nuclear power plants

Abstract Cyber-attacks against critical energy infrastructure have gone from possible to eventual to actual. With electrical generation sources in the United States changing under a wide range of pressures, the current fleet of nuclear power plants in the United States provides a reliable and sustainable source of electrical generation capacity. However, in order to extend the lifetime of the fleet, modernization upgrades to digital instrumentation and control systems are required. While this produces many opportunities for increased efficiency, it introduces a new level of complexity for securing and reliably operating reactors in the presence cyber-threats. The United States Nuclear Regulatory Commission recently began urging stronger cybersecurity efforts at nuclear power plants. As upgrades at nuclear power plants begin, the implementation of digital instrumentation and control systems to monitor and run the power plant introduces new vulnerabilities that must be addressed. This necessitates a more modern discussion of risk. Within this context, we critically review past cyber-vulnerability incidents at nuclear installations and other critical facilities. We then analyze challenges to vulnerabilities within the context of modernization of the current nuclear fleet and propose future research directions needed to resolve these issues.
Gotcha: An Function-Wrapping Interface for HPC Tools

This paper introduces Gotcha, a function wrapping interface and library for HPC tools. Many HPC tools, and performance analysis tools in particular, rely on function wrapping to integrate with applications. But existing mechanisms, such as LD_PRELOAD on Linux, have limitations that lead to tool instability and complexity. Gotcha addresses the limitations in existing mechanisms, provides a programmable interface for HPC tools to manage function wrapping, and supports function wrapping across multiple tools. In addition, this paper introduces the idea of interface-independent function wrapping, which makes it possible for tools to wrap arbitrary application functions.
Letter to the Editor - Detecting HTS Barcode Contamination.

Abstract DNA barcoding enables multiple samples to be characterized in parallel with high throughput sequencing (HTS) experiments for cost efficiencies. Cross-contamination of DNA barcode reagents can result in the detection of HTS sequences for barcodes that were not originally added to a particular sample. Cross-contamination of data between multiplexed samples can also occur. Avoidance and detection of contaminated barcodes is relevant for DNA forensic samples analysis, accurate cancer diagnosis, clinical research applications, metagenomic analysis, etc. We present recommendations for the avoidance of contamination and a tool, TallyBarcodes, to aid in the detection of DNA barcode contamination.
Building Scholars and Communities of Practice in Digital Heritage and Archaeology

As the role of digital methods in heritage and archaeology has increased in prominence, so has the question of capacity and community building. Who should receive training in digital methods? How should training take place? What concepts, platforms, technologies should be taught? These are relevant questions requiring careful planning and thoughtful implementation; yet beyond these questions, there is an issue of even greater importance: the planned development of communities of practice. The teaching of digital methods has a greater chance of success if it takes place in an ecosystem of scholars who are connected to one another through shared perspectives on those methods. This article presents and discusses the details of a model developed at Michigan State University that speaks to teaching digital archaeology and heritage methods, and to the development of communities of practice in which those methods are shared and relevant. The model is driven and informed by the activities of three projects: the National Endowment for the Humanities-funded Institute on Digital Archaeology Method & Practice, the Cultural Heritage Informatics Graduate Fellowship Program, and the Department of Anthropology Digital Cultural Heritage Fieldschool.
Neuropathological correlates and genetic architecture of microglial activation in elderly human brain.

Microglia, the resident immune cells of the brain, have important roles in brain health. However, little is known about the regulation and consequences of microglial activation in the aging human brain. Here we report that the proportion of morphologically activated microglia (PAM) in postmortem cortical tissue is strongly associated with β-amyloid, tau-related neuropathology, and the rate of cognitive decline. Effect sizes for PAM measures are substantial, comparable to that of APOE e4, the strongest genetic risk factor for Alzheimer’s disease, and mediation models support an upstream role for microglial activation in Alzheimer’s disease via accumulation of tau. Further, we identify a common variant (rs2997325) influencing PAM that also affects in vivo microglial activation measured by [11C]-PBR28 PET in an independent cohort. Thus, our analyses begin to uncover pathways regulating resident neuroinflammation and identify overlaps of PAM’s genetic architecture with those of Alzheimer’s disease and several other traits. The consequences of microglial activation in the aging human brain remain unknown. This study quantified microglial morphology and density in the elderly human brain to show that cortical microglial activation strongly associates with AD pathogenesis and may be an upstream contributor to cognitive decline via the accumulation of tau pathology.
Self-assembly of a polar open-framework uranyl vanadyl hexaoxoiodate(VII) constructed entirely from distorted octahedral building units in the first uranium hexaoxoiodate: K2[(UO2)2(VO)2(IO6)2O].H2O

The reaction of UO3 with V2O5 and KIO4 under mild hydrothermal conditions produces K2[(UO2)2(VO)2(IO6)2O]·H2O (1) in the form of orange acicular crystals. The structure of 1 consists of UO6, VO6, and IO6 distorted octahedra that are assembled into a polar, open-framework structure. The distorted VO6 and IO6 octahedra edge-share to form chains that run down the c-axis. Each VO6 octahedron also shares a vertex with an adjacent vanadium atom to link the chains together into a ribbon. The IO6 units also partake in corner-sharing with the UO6 units to create interconnected elliptical tubes. The major channels in 1 are filled with K+ cations and water molecules. The polarity of this compound is caused by alignment of distorted vanadyl hexaoxoiodate ribbons and UO6 trapezoidal bipyramids resulting in a large second-harmonic generation response of 300 times that of α-quartz. Crystallographic data: 1, orthorhombic, space group Pba2, a = 9.984(2) A, b = 16.763(3) A, c = 4.977(1) A, Z = 4 (T = 193 K).
The use of supercritical fluids as solvents for NMR spectroscopy

The goal of this article is to introduce the reader to the use of supercritical fluids as solvents in high-pressure NMR experiments and present some of the interesting research currently being pursued using the technique of high-pressure NMR and the applications of supercritical fluids in this dynamic area. A supercritical fluid can be readily defined for a single component as a solvent above its critical temperature and critical pressure such that no change in pressure can introduce a phase transition in the single fluid phase. While these temperature and pressure conditions are well established for a pure solvent system, for binary and ternary solvents the supercritical conditions and phase behavior are sometimes difficult to determine. Therefore, not only can the physical properties of the solvent be altered with pressure and temperature, but the phase equilibria in supercritical fluid solvents must also be considered. The goal of this article is not to present an in-depth discussion of the different physical states involved in the phase behavior of high-pressure, high-temperature solvents, such as supercritical fluids. There have been numerous reviews of the different properties and behaviors of fluids phases and the interested reader is referred to the excellent recent review by Grunwaldtmore » et al..1 The literature in this article referenced generally covers the time period from 2000 to early 2005.« less
Facile palladium-mediated substitution of chlorine in 2-chloroquinolines

Abstract Unlike ordinary aryl chlorides, the title hererocycles participate readily in Castro-Stephens, Stille, Suzuki, and carbonylation reactions under the catalytic influence of Pd(0).
Convergent and Stereospecific Synthesis of Molecules Containing α-Functionalized Guanidiniums via α-Guanidino Acids

To introduce chirality and functional groups adjacent to guanidiniums to modulate specificity and affinity in recognition, N,N‘-bis(Boc)-α-guanidino acids were synthesized from α-amino acid methyl esters. Protected α-guanidino acids coupled to cyclohexylamine and trans-1,4-diaminocyclohexane in good yield and with retention of stereochemistry. Boc deprotection was conducted under mild acidic conditions (0.5 M HCl/EtOAc) to minimize epimerization. The deprotected guanidinium is configurationally stable under more acidic conditions. This approach represents a practical, convergent, stereospecific methodology to introduce chiral α-substituted guanidinium groups into molecules.
Asymmetric synthesis of non-natural homologues of lysine

Abstract A series of non-natural amino acid homologues of l - and d -lysine have been synthesized and protected for use in solid-phase peptide synthesis. With these residues, electrostatics and hydrophobicity of peptides can be enhanced or altered.
Quarkonium in a Non-Ideal Hot QCD Plasma

Substantial anisotropies should occur in the hot expanding QCD plasma produced in relativistic heavy-ion collisions due to non-vanishing shear viscosity. We discuss the form of the real-time, hard thermal loop resummed propagator for static gluons in the presence of such anisotropies and the consequences for quarkonium binding. It has been predicted that the propagator develops an imaginary part due to Landau damping at high temperature. This should generate a much larger width of quarkonium states than the Appelquist-Politzer vacuum estimate corresponding to decay into three gluons. We argue that this might be
Mild and efficient synthesis of thiocarbonates and thiocarbamates via a three-component coupling utilizing Cs2CO3 and TBAI

Abstract The presence of cesium carbonate and tetrabutylammonium iodide (TBAI) facilitated efficient thiocarbonylation of alcohols, and thiocarbamation of amines, using carbon disulfide with alkyl halides. This protocol was mild, chemoselective, and efficient, compared to the existing methods.
Enteral Activation of WR-2721 Mediates Radioprotection and Improved Survival from Lethal Fractionated Radiation

Unresectable pancreatic cancer is almost universally lethal because chemotherapy and radiation cannot completely stop the growth of the cancer. The major problem with using radiation to approximate surgery in unresectable disease is that the radiation dose required to ablate pancreatic cancer exceeds the tolerance of the nearby duodenum. WR-2721, also known as amifostine, is a well-known radioprotector, but has significant clinical toxicities when given systemically. WR-2721 is a prodrug and is converted to its active metabolite, WR-1065, by alkaline phosphatases in normal tissues. The small intestine is highly enriched in these activating enzymes, and thus we reasoned that oral administration of WR-2721 just before radiation would result in localized production of the radioprotective WR-1065 in the small intestine, providing protective benefits without the significant systemic side effects. Here, we show that oral WR-2721 is as effective as intraperitoneal WR-2721 in promoting survival of intestinal crypt clonogens after morbid irradiation. Furthermore, oral WR-2721 confers full radioprotection and survival after lethal upper abdominal irradiation of 12.5 Gy × 5 fractions (total of 62.5 Gy, EQD2 = 140.6 Gy). This radioprotection enables ablative radiation therapy in a mouse model of pancreatic cancer and nearly triples the median survival compared to controls. We find that the efficacy of oral WR-2721 stems from its selective accumulation in the intestine, but not in tumors or other normal tissues, as determined by in vivo mass spectrometry analysis. Thus, we demonstrate that oral WR-2721 is a well-tolerated, and quantitatively selective, radioprotector of the intestinal tract that is capable of enabling clinically relevant ablative doses of radiation to the upper abdomen without unacceptable gastrointestinal toxicity.
P(i-PrNCH2CH2)3N as a Lewis Base Catalyst for the Synthesis of β-Hydroxynitriles Using TMSAN

Proazaphosphatrane 1a was found to be an efficient catalyst for synthesis of beta-hydroxynitriles via the reaction of trimethylsilylacetonitrile (TMSAN) with aldehydes under mild reaction conditions and typically low catalyst loading (ca. 2 mol %). A variety of functional groups were tolerated, and good to excellent product yields were obtained.
An oxepinone route to carbohydrate based oxepines

Oxepines are ring expanded analogs of glycals that can be used to prepare septanose carbohydrates. A route to carbohydrate based oxepines that utilizes oxepinones as a key intermediate has been developed. The oxepinone intermediates were prepared via an amine catalyzed cycloisomerization of furanose hemi-ketals. 1,2-Reduction of the oxepinones followed by acetylation provided the novel ring expanded enol ether products. Moderate diastereoselectivity was observed for the reduction based on the starting oxepinone. 1,4-Addition onto the oxepinones was also demonstrated. Overall, the syntheses reported here will allow for ready access to novel ring expanded carbohydrate analogs.
What controls the rates of interprotein electron-transfer reactions.

Rates of electron-transfer (ET) reactions are dependent on driving force, reorganizational energy, distance, and the nature of the medium which the electron must traverse. In kinetically complex biological systems, non-ET reactions may be required to activate the system for ET and may also influence the observed rates. Studies of ET from tryptophan tryptophylquinone to copper to heme in the methylamine dehydrogenase−amicyanin−cytochrome c-551i ET complex, as well as studies of other physiologic redox protein complexes, are used to illustrate the combination of factors which control rates of interprotein ET reactions.
A general method for the preparation of 1,1-bis(trifluoromethyl)substituted olefins

Abstract The title compounds are prepared by treatment of 1,1-difluoro-2-trifluoromethyl-1-alken-3-ols ( 1 ) with diethylaminosulfur trifluoride (DAST) with high regioselectivity. The alcohols ( 1 ) are obtained by the reaction of 2-pentafluoropropenyllithium with aldehydes and ketones.
Room temperature synthesis of glycerol carbonate catalyzed by N-heterocyclic carbenes

Abstract N -Heterocyclic carbenes were used as efficient organocatalysts for the synthesis of glycerol carbonate from glycerol and dimethyl carbonate. The reaction takes place in a liquid mixture of reactants without solvent at room temperature. It provides glycerol carbonate in high yield using 2.6–4 mol % of catalyst in a reaction period of 20–30 min.
Weighted Sparse Bayesian Learning (WSBL) for Basis Selection in Linear Underdetermined Systems

We propose Weighted SBL (WSBL) for sparse signal recovery, inspired by the Sparse Bayesian Learning (SBL) method. Unlike SBL, where all hyperparameter priors follow Gamma distributions with identical parameters, in WSBL, the hyperparameters are Gamma distributed with distinct parameters. These parameters, guided by some known weights, give more importance to some hyperparameters over others, thus introducing more degrees of freedom to the problem and leading to better recovery performance. The weights can be determined based on a low-resolution estimate of the sparse vector, for example, an estimate obtained via a method that does not encourage sparsity. The choice of the MUSIC estimate as weight is analyzed. Unlike in SBL, the WSBL hyperparameters are upper bounded; this makes it easy to select a threshold to separate zero from non-zero elements in the recovered sparse vector, which makes the iterative recovery process converge faster. Theoretical analysis based on variational approximation theory and also simulation results demonstrate that WSBL results in substantial improvement in terms of probability of detection and probability of false alarm, especially in the low signal to noise ratio regime , as compared to existing approaches, such as SBL, Sparse Bayesian Support knowledge (BSN), and Multiple response Sparse Bayesian Learning (MSBL). The performance of WSBL is evaluated for Direction of Arrival (DOA) estimation in colocated Multiple Input Multiple Output (MIMO) radar.
The reaction of dimethyltitanocene with N-substituted-β-lactams

Abstract 2-Methyleneazetidines have been synthesized and isolated by the reaction of β-lactams with dimethyltitanocene, followed by chromatography on deactivated silica. Efficient conversion required that the lactam nitrogen be strongly deactivated. Methyl transfer predominated in reactions with phenyl and benzyl on the lactam nitrogen.
Possibility of the Existence of Non-Carbon Fullerenes: Ab Initio HF and DFT/B3LYP Studies of the IV Main Group Fullerene-Like Species

A comprehensive investigation of the equilibrium geometries, cohesive energies, and electronic properties of the IV main group fullerene-like compounds C60, Si60, Ge60, Sn60, and Pb60, has been performed by ab initio molecular modeling at the HF/Lanl1DZ and B3LYP/Lanl1DZ levels. In addition, the effect of the basis set on the structure and properties of C60 and Si60 has been examined at the STO-3G, Lanl1DZ, and 6-31G(d) levels. Our calculations confirmed the possibility of the existence of these species. It was found that the values of the relative bond alternation, cohesive energy, HOMO−LUMO gap, and the ionization potential of the molecules decrease monotonically in going down the IVth group from C60 to Pb60. The obtained data for Ge60 is rather similar to the one for Si60, and also the molecular parameters for Sn60 are close to the appropriate values both for Si60 and Ge60.
A new indole synthesis via [3+3] annulation of 2-(benzotriazol-1-ylmethyl)-pyrroles with α,β-unsaturated aldehydes and ketones

Abstract Poly-substituted indoles are readily accessible from substituted 2-(benzotriazol-1-ylmethyl)pyrrobles by lithiation, reaction with α,β-unsaturated aldehydes and ketones, and subsequent facile dehydrobenzotriazolylation-cyclodehydration. The substituted 2-(benzotriazol-1-ylmethyl)-pyrrole precursors are obtained by reacting α-bromoketones with terminally lithiated propargylbenzotriazole, and treating the resulting epoxide with a primary amine.
Ruthenium-catalyzed alkene-alkyne coupling of disubstituted olefins: application to the stereoselective synthesis of trisubstituted enecarbamates.

The Ru-catalyzed alkene–alkyne coupling reaction has been demonstrated to be an enabling methodology for the synthesis of complex molecules. However, to date, it has been limited to monosubstituted olefins. Herein we report the first general utilization of disubstituted olefins in the Ru-catalyzed alkene–alkyne coupling reaction by employing carbamate directing groups. The products are stereodefined trisusbstituted enecarbamates. The elaboration of these structures toward the asymmetric synthesis of complex aminocyclopentitols and 1,2-amino alcohols is discussed.
An efficient and practical direct resolution of racemic 1,1′-bi-2-naphthol to both of its pure enantiomers

Abstract An efficient and practical method to directly resolve racemic 1,1′-bi-2-naphthol, rac- 1 , into optically pure R and S- 1 has been developed by modification of a N-benzylcinchonidinium chloride resolution procedure. In a typical experiment, 60 g of rac- 1 is resolved to give 22.5 g of R- 1 (75%, >99% ee) and 21 g of S- 1 (70%, >99% ee). The chiral resolving agent, (8S, 9R)-(−)-N-benzylcinchonidinium chloride, 2 , is recovered in 80% yield.
Efficient synthesis of substituted benzenes from 1,3-dienes or 1,4-cyclohexadienes with KMnO4 under mild conditions

Abstract Potassium permanganate absorbed on alumina is used to oxidize 1,4-cyclohexadienes to the corresponding aromatic compounds. Intermolecular Diels-Alder reactions followed by dehydrogenation of the products with potassium permanganate supported on alumina gives an efficient two step synthesis of highly substituted aromatic compounds from acyclic precursors.
Convenient synthesis of primary sulfonamides

An efficient protocol for a one-pot synthesis of mono-sulfonamides has been developed. It features utilization of excess of sulfonylating agent followed by base mediated recovery of the primary sulfonamide.
Hydrodynamic cavitation as an energy efficient process to increase biochar surface area and porosity: A case study

Abstract The effectivity of biochar as soil amendment depends on its physical and chemical characteristics, related to the type and features of the thermal production process, such as peak temperature, heating rate, holding time, as well as on the used feedstock. The textural characteristics of biochar in terms of surface area, pore size and pore volume distribution, important for its physicochemical properties, are critically dependent on the feedstock type, the production process, and possible further activation methods. This study was based on a single biochar type, resulting from slow pyrolysis at the working temperature of 550 °C of raw material from coppiced woodlands, as well as on a single experiment. For the first time, controlled hydrodynamic cavitation was proven as a fast and effective way to enhance the surface area of biochar by as much as 120%, while preserving or improving the respective chemical composition. The introduced technique, while easily applicable and scalable, showed far higher efficiency than the conventional method of increasing the working temperature of the pyrolysis process, with higher process yields by at least an order of magnitude. Moreover, hydrodynamic cavitation processes could be straightforwardly integrated with other consolidated methods, such as hydrothermal carbonization and chemical activation, possibly leading to effective synergism.
Stereoselective preparation of (Z)-2-(trialkylsilyloxy)-2-alkenals by retrocycloaddition reactions of 4H-4-Alkyl-5-(trialkylsilyloxy)-1,3-dioxins. Useful reactants for Lewis acid catalyzed [4 + 3] cyclizations.

Retrocycloadditions of 4H-4-alkyl-5-(trialkylsilyloxy)-1,3-dioxins proceed smoothly in refluxing toluene to afford (Z)-2-(trialkylsilyloxy)-2-alkenals with complete stereoselectivity. These enals undergo Sasaki-type [4 + 3] cyclizations with dienes in the presence of Lewis acids, in many instances with excellent regio- and/or stereoselectivity.
Divergent Pathways in the Intramolecular Reactions between Rhodium-Stabilized Vinylcarbenoids and Pyrroles: Construction of Fused Tropanes and 7-Azabicyclo[4.2.0]octadienes

The rhodium(II)-catalyzed intramolecular reaction between vinyldiazomethanes and pyrroles leads to a novel synthesis of fused tropanes. The reaction occurs by a stepwise 3 + 4 annulation mechanism between a rhodium-stabilized vinylcarbenoid intermediate and the pyrrole rather than by the typical tandem cyclopropanation/Cope rearrangement sequence. The outcome of the reaction is very sensitive to the vinylcarbenoid structure. In particular, the presence of a 2-siloxy substituent on the vinylcarbenoid strongly favors the formation of fused tropanes. In the absence of such functionality, the formation of fused 7-azabicyclo[4.2.0]octadienes becomes the dominant reaction pathway.
The reductive Nazarov cyclization

Abstract Tri- and tetrasubstituted 1,4-dien-3-ones 1 were treated with Lewis acid in the presence of triethylsilane, furnishing either silyl enol ethers 4 or cyclopentanones 5 in good yields, depending upon work-up conditions. This reaction is presumed to occur through oxyallyl intermediate 3 , which undergoes intermolecular hydride transfer and O-silylation to give 4 . In most cases, only 2 equiv. of silane was required, and catalytic amounts of Lewis acid could be used. Trienone substrate 7 was found to undergo clean conversion to tricyclic ether 8 , indicating fast capture of the oxyallyl intermediate by the pendant olefin.
Instanton induced large N phase transitions in two and four dimensional QCD

Abstract The 1/ N expansion of the weak coupling phase of two-dimensional QCD on a sphere is constructed. It is demonstrated that the phase transition from the weak to the strong coupling phase is induced by instantons. A double scaling limit of the theory at the point of the phase transition is constructed, the value of string susceptibility is determined to be γ str = −1. The possibility of instanton induced large N phase transitions in four-dimensional QCD is explored.
Photoionization of Galactic Halo Gas by Old Supernova Remnants

We present new calculations on the contribution from cooling hot gas in old supernova remnants to the photoionization of warm ionized gas in the Galaxy. We show that the emission from the hot gas in cooling supernova remnants (SNRs) is soft ( E 20 eV) and, as a result, the eciency of conversion of supernova explosion energy into ionizing photons is high, 30 { 40%. Given this high eciency , supernova remnants could be responsible for up to 50% of the emission measure observed for the warm ionized medium in the Galaxy. Our model ux is also consistent with the diuse soft X-ray background at high latitude and with soft X-ray observations of external galaxies. We consider the ionization of the clouds observed towards the halo star HD 93521, for which there are no O stars close to the line of sight. We nd that the observed ionization can be explained successfully by our model ux.
Benzilic acid rearrangements in the reactions of aryl vicinal tricarbonyl derivatives with aldehyde schiff bases

Abstract Reactions of aryl and hetero vicinal tricarbonyl derivatives with aldehyde Schiff bases of the general structure RCH2CHO lead to pyrrolinone derivatives by benzilic acid-related rearrangements, driven, most probably, by iminium ion intermediates.
Historian: accurate reconstruction of ancestral sequences and evolutionary rates

Motivation Reconstruction of ancestral sequence histories, and estimation of parameters like indel rates, are improved by using explicit evolutionary models and summing over uncertain alignments. The previous best tool for this purpose (according to simulation benchmarks) was ProtPal, but this tool was too slow for practical use. Results Historian combines an efficient reimplementation of the ProtPal algorithm with performance-improving heuristics from other alignment tools. Simulation results on fidelity of rate estimation via ancestral reconstruction, along with evaluations on the structurally informed alignment dataset BAliBase 3.0, recommend Historian over other alignment tools for evolutionary applications. Availability and implementation Historian is available at https://github.com/evoldoers/historian under the Creative Commons Attribution 3.0 US license. Contact ihholmes+historian@gmail.com.
Highly selective syn glycolate aldol reactions with boron enolates of Masamune norephedrine esters

Abstract Boron enolates of norephedrine-based glycolate esters reacted with various aldehydes to produce syn aldol products in high yield and selectivity. The outcome is consistent with a Z enolate reacting through a closed transition state with reversal of the enolate facial selectivity relative to the propionate enolates.
Synthesis of fluorosugar analogues of 2,5,6-trichloro-1-(β-D-ribofuranosyl)benzimidazole as antivirals with potentially increased glycosidic bond stability

The metabolic instability in vivo of the glycosidic bond of 2,5,6-trichloro-1-(β-d-ribofuranosyl)benzimidazole (TCRB) prompted us to design and synthesize the hitherto unreported fluorinated benzimidazole nucleosides 2,5,6-trichloro-1-(2-deoxy-2-fluoro-β-d-arabinofuranosyl)benzimidazole, 2,5,6-trichloro-1-(3-deoxy-3-fluoro-β-d-xylofuranosyl)benzimidazole, and 2-bromo-5,6-dichloro-1-(2-deoxy-2-fluoro-β-d-ribofuranosyl)benzimidazole. TCRB was converted into the 2‘,5‘-ditrityl and 3‘,5‘-ditrityl derivatives, which were fluorinated with DAST and deprotected to yield 2,5,6-trichloro-1-(2-deoxy-2-fluoro-β-d-arabinofuranosyl)benzimidazole and 2,5,6-trichloro-1-(3-deoxy-3-fluoro-β-d-xylofuranosyl)benzimidazole. The resulting low overall yield (5%) of 2,5,6-trichloro-1-(2-deoxy-2-fluoro-β-d-arabinofuranosyl)benzimidazole encouraged us to develop an alternative route. The heterocycle 2,5,6-trichlorobenzimidazole was condensed with 1-bromo-3,5-di-O-benzoyl-2-deoxy-2-fluoro-α-d-arabinofuranose to give, after deprotec...
On Benjamini–Hochberg procedure applied to mid p-values

Abstract Multiple testing with discrete p -values routinely arises in various scientific endeavors. However, procedures, including the false discovery rate (FDR) controlling Benjamini–Hochberg (BH) procedure, often used in such settings, being developed originally for p -values with continuous distributions, are too conservative, and so may not be as powerful as one would hope for. Therefore, improving the BH procedure by suitably adapting it to discrete p -values without losing its FDR control is currently an important path of research. This paper studies the FDR control of the BH procedure when it is applied to mid p -values and derive conditions under which it is conservative. Our simulation study reveals that the BH procedure applied to mid p -values may be conservative under much more general settings than characterized in this work, and that an adaptive version of the BH procedure applied to mid p -values is as powerful as an existing adaptive procedure based on randomized p -values.
Synthesis of cyclopentenones via intramolecular HWE and the palladium-catalyzed reactions of allylic hydroxy phosphonate derivatives.

Palladium-catalyzed decarboxylative rearrangement of nonracemic phosphono allylic acetoacetates, or the intermolecular allylic substitution of nonracemic phosphono allylic carbonates with tert-butyl acetoacetate followed by hydrolysis and decarboxylation, gave ω-ketovinyl phosphonates. A highly regioselective Wacker oxidation gave the ω,β-diketophosphonates which underwent intramolecular HWE reaction to give nonracemic cyclopentenones. An aldol condensation leading to phosphonocyclopentenones was competitive with the HWE reaction. The stereochemistry of the cyclopentenone and the ratio of HWE to aldol products were dependent upon the choice of base used in the reaction.
Total synthesis of (-)-and ent-(+)-4 -desacetoxy -5 -desethylvindoline

A concise synthesis of (-)- and ent-(+)-4-desacetoxy-5-desethylvindoline (2), a key analogue of vindoline, is disclosed enlisting an intramolecular tandem [4+2]/[3+2] cycloaddition cascade of 1,3,4-oxadiazole (5) to assemble the pentacyclic skeleton of 2 in a single step that forms three new rings, four C-C bonds, and sets all five key stereocenters. The subsequent efforts on the elaboration of 6 to 2 revealed two subtle features key to our recent total syntheses of vindoline, vindorosine, and related natural products based on this strategy.
Submodular Optimization for Coupled Task Allocation and Intermittent Deployment Problems

In this letter, we demonstrate a formulation for optimizing coupled submodular maximization problems with provable sub-optimality bounds. In robotics applications, it is quite common that optimization problems are coupled with one another and therefore cannot be solved independently. Specifically, we consider two problems coupled if the outcome of the first problem affects the solution of a second problem that operates over a longer time scale. For example, in our motivating problem of environmental monitoring, we posit that multi-robot task allocation will potentially impact environmental dynamics and thus influence the quality of future monitoring, here modeled as a multi-robot intermittent deployment problem. The general theoretical approach for solving this type of coupled problem is demonstrated through this motivating example. Specifically, we propose a method for solving coupled problems modeled by submodular set functions with matroid constraints. A greedy algorithm for solving this class of problem is presented, along with sub-optimality guarantees. Finally, practical optimality ratios are shown through Monte Carlo simulations to demonstrate that the proposed algorithm can generate near-optimal solutions with high efficiency.
State statutes and regulations related to human papillomavirus vaccination

A cross-sectional analysis of human papillomavirus (HPV) vaccine statutes and regulations from states and the District of Columbia in the United States (U.S.) was conducted from September–November ...
Asymptotic behavior of flows by powers of the Gaussian curvature

We consider a $1$-parameter family of strictly convex hypersurfaces in $\mathbb{R}^{n+1}$ moving with speed $-K^{\alpha} ν$, where ν denotes the outward-pointing unit normal vector and $\alpha \geqslant 1 / (n+2)$. For $\alpha \gt 1 / (n+2)$, we show that the flow converges to a round sphere after rescaling. In the affine invariant case $\alpha = 1 / (n+2)$, our arguments give an alternative proof of the fact that the flow converges to an ellipsoid after rescaling.
Learning Sample-Efficient Target Reaching for Mobile Robots

In this paper, we propose a novel architecture and a self-supervised policy gradient algorithm, which employs unsupervised auxiliary tasks to enable a mobile robot to learn how to navigate to a given goal. The dependency on the global information is eliminated by providing only sparse range-finder measurements to the robot. The partially observable planning problem is addressed by splitting it into a hierarchical process. We use convolutional networks to plan locally, and a differentiable memory to provide information about past time steps in the trajectory. These modules, combined in our network architecture, produce globally consistent plans. The sparse reward problem is mitigated by our modified policy gradient algorithm. We model the robots uncertainty with unsupervised tasks to force exploration. The novel architecture we propose with the modified version of the policy gradient algorithm allows our robot to reach the goal in a sample efficient manner, which is orders of magnitude faster than the current state of the art policy gradient algorithm. Simulation and experimental results are provided to validate the proposed approach.
Tracking Dynamic Point Processes on Networks

Cascading chains of events are a salient feature of many real-world social, biological, and financial networks. In social networks, social reciprocity accounts for retaliations in gang interactions, proxy wars in nation-state conflicts, or the Internet memes shared via social media. Neuron spikes stimulate or inhibit spike activity in other neurons. Stock market shocks can trigger a contagion of volatility throughout a financial network. In these and other examples, only individual events associated with network nodes are observed, usually without the knowledge of the underlying dynamic relationships between nodes. This paper addresses the challenge of tracking how events within such networks stimulate or influence future events. The proposed approach is an online learning framework well-suited to streaming data, using a multivariate Hawkes point process model to encapsulate autoregressive features of observed events within the social network. Recent work on online learning in dynamic environments is leveraged not only to exploit the dynamics within the underlying network, but also to track the network structure as it evolves. Regret bounds and experimental results demonstrate that the proposed method performs nearly as well as an oracle or batch algorithm.
Learning Word-Like Units from Joint Audio-Visual Analysis

Given a collection of images and spoken audio captions, we present a method for discovering word-like acoustic units in the continuous speech signal and grounding them to semantically relevant image regions. For example, our model is able to detect spoken instances of the word ‘lighthouse’ within an utterance and associate them with image regions containing lighthouses. We do not use any form of conventional automatic speech recognition, nor do we use any text transcriptions or conventional linguistic annotations. Our model effectively implements a form of spoken language acquisition, in which the computer learns not only to recognize word categories by sound, but also to enrich the words it learns with semantics by grounding them in images.
node2vec: Scalable Feature Learning for Networks

Prediction tasks over nodes and edges in networks require careful effort in engineering features used by learning algorithms. Recent research in the broader field of representation learning has led to significant progress in automating prediction by learning the features themselves. However, present feature learning approaches are not expressive enough to capture the diversity of connectivity patterns observed in networks. Here we propose node2vec, an algorithmic framework for learning continuous feature representations for nodes in networks. In node2vec, we learn a mapping of nodes to a low-dimensional space of features that maximizes the likelihood of preserving network neighborhoods of nodes. We define a flexible notion of a node's network neighborhood and design a biased random walk procedure, which efficiently explores diverse neighborhoods. Our algorithm generalizes prior work which is based on rigid notions of network neighborhoods, and we argue that the added flexibility in exploring neighborhoods is the key to learning richer representations. We demonstrate the efficacy of node2vec over existing state-of-the-art techniques on multi-label classification and link prediction in several real-world networks from diverse domains. Taken together, our work represents a new way for efficiently learning state-of-the-art task-independent representations in complex networks.