cssi/SciSciGPT-SciSciNet huggingface dataset:
Chapter 19 – Viscous and Non-Newtonian Flows

The solutions to viscous and non-Newtonian fluid flow problems are presented. The basic equations governing two-dimensional steady incompressible Newtonian flow and its boundary conditions are stated in terms of the pressure, velocity, and velocity gradient, along with possible solution methods. The solution methods are based on the use of the stream function formulation, which treats the stream function as an unknown, the velocity–pressure formulation with velocity components and the pressure as unknowns, and the stream function–vorticity formulation with the stream function and vorticity as unknowns. The stream function formulation is outlined using a variational approach. Because no universally accepted variational principle is available for solving Navier–Stokes equations, the pseudovariational principle, given by Olson, is used to present the finite element solution, based on an 18 degrees of freedom–conforming triangular element. The velocity–pressure formulation, based on the Galerkin method, is outlined by developing the finite element equations. An iterative solution is given for solving full Navier–Stokes equations. The stream function–vorticity formulation, coupled with the variational approach, is used to derive the finite element equations. Finally, the finite element solution to non-Newtonian fluid flow problems is presented using the Galerkin method along with an iterative method for the solution.
Screening for neurotoxic potential of 15 flame retardants using freshwater planarians.

Abstract Asexual freshwater planarians are an attractive invertebrate model for high-throughput neurotoxicity screening, because they possess multiple quantifiable behaviors to assess distinct neuronal functions. Planarians uniquely allow direct comparisons between developing and adult animals to distinguish developmentally selective effects from general neurotoxicity. In this study, we used our automated planarian screening platform to compare the neurotoxicity of 15 flame retardants (FRs), consisting of representative phased-out brominated (BFRs) and replacement organophosphorus FRs (OPFRs). OPFRs have emerged as a proposed safer alternative to BFRs; however, limited information is available on their health effects. We found 11 of the 15 FRs (3/6 BFRs, 7/8 OPFRs, and Firemaster 550) caused adverse effects in both adult and developing planarians with similar nominal lowest-effect-levels for BFRs and OPFRs. This suggests that replacement OPFRs are comparably neurotoxic to the phased-out compounds. BFRs were primarily systemically toxic, whereas OPFRs, except Tris(2-chloroethyl) phosphate, shared a behavioral phenotype in response to noxious heat at sublethal concentrations, indicating specific neurotoxic effects. We found this behavioral phenotype was correlated with cholinesterase inhibition, thus linking behavioral outcomes to molecular targets. By directly comparing effects on adult and developing planarians, we further found that one BFR (3,3′,5,5′-Tetrabromobisphenol A) caused a developmental selective defect. Together, these results demonstrate that our planarian screening platform yields high content data from various behavioral and morphological endpoints, allowing us to distinguish selective neurotoxic effects and effects specific to the developing nervous system. Ten of these 11 bioactive FRs were previously found to be bioactive in other models, including cell culture and alternative animal models (nematodes and zebrafish). This level of concordance across different platforms emphasizes the urgent need for further evaluation of OPFRs in mammalian systems.
Electromagnetic Wave Scattering

Electromagnetic wave scattering is the reradiation of electromagnetic energy that results when an electromagnetic field encounters an abrupt change in electrical parameters. Typically, this occurs when an electromagnetic field is incident on a structure or scattering object. When the original electromagnetic field crosses the boundary between two regions of different materials, each with different electrical properties, the field will change as it enters the second region. Sources, including conduction, displacement, and polarization currents, will be induced at the discontinuity between the two regions. These currents act as sources of electromagnetic radiation, much like the sources of the original incident electromagnetic field. This reradiation is called electromagnetic scattering because it scatters the incident electromagnetic field from its original propagation path. Keywords: propagation; scattering; diffraction; reflection; refraction
CEO/CFO Resignations and the Market's Reaction to Violations of the Foreign Corruption Practices Act

ABSTRACT I examine CEOs' and CFOs' forced resignations after violations of the Foreign Corruption Practices Act (FCPA). My findings show that firms that adhere to the FCPA (FCPA firms) discipline C...
Understanding how a falling ball chain can be speeded up by impact onto a surface

When a falling ball chain strikes a surface, a tension is created that pulls the chain downward. This causes a downward acceleration that is larger than free-fall, which has been observed by recent...
Diastereoselectivity in the Carroll rearrangement of β-keto esters of tertiary allylic alcohols

Carroll rearrangement of β-keto esters derived from tertiary allylic alcohols, for example, 7, under basic conditions followed by decarboxylation of the resulting β-keto acids yielded the expected γ,δ-unsaturated methyl ketones 8 with a range of olefin geometries from 100:0 to 1:1.8 E/Z, depending on the relative steric requirements of the two groups at the allylic center.
Novel and efficient synthesis of 4-sulfonyl-2-pyridones

Abstract Heterocyclic 4-sulfonyl-2-pyridones represent useful scaffolds for drug discovery, and are also versatile synthetic building blocks. Herein, we describe a novel and efficient synthesis of this heterocyclic ring system utilizing an acid-mediated cyclo-condensation reaction. This synthetic method affords convenient access to structurally diverse N-substituted 4-sulfonyl-2-pyridones in moderate to good yields.
Ultraaccurate genome sequencing and haplotyping of single human cells

Accurate detection of variants and long-range haplotypes in genomes of single human cells remains very challenging. Common approaches require extensive in vitro amplification of genomes of individual cells using DNA polymerases and high-throughput short-read DNA sequencing. These approaches have two notable drawbacks. First, polymerase replication errors could generate tens of thousands of false-positive calls per genome. Second, relatively short sequence reads contain little to no haplotype information. Here we report a method, which is dubbed SISSOR (single-stranded sequencing using microfluidic reactors), for accurate single-cell genome sequencing and haplotyping. A microfluidic processor is used to separate the Watson and Crick strands of the double-stranded chromosomal DNA in a single cell and to randomly partition megabase-size DNA strands into multiple nanoliter compartments for amplification and construction of barcoded libraries for sequencing. The separation and partitioning of large single-stranded DNA fragments of the homologous chromosome pairs allows for the independent sequencing of each of the complementary and homologous strands. This enables the assembly of long haplotypes and reduction of sequence errors by using the redundant sequence information and haplotype-based error removal. We demonstrated the ability to sequence single-cell genomes with error rates as low as 10-8 and average 500-kb-long DNA fragments that can be assembled into haplotype contigs with N50 greater than 7 Mb. The performance could be further improved with more uniform amplification and more accurate sequence alignment. The ability to obtain accurate genome sequences and haplotype information from single cells will enable applications of genome sequencing for diverse clinical needs.
A diastereoselective synthesis of (2S, 3R, 4S)-2-amino-1-cyclohexyl-6-methylheptane-3,4-diol, the Abbott aminodiol

Abstract An efficient asymmetric synthesis of the Abbott aminodiol, 1, is described beginning with the readily-available starting material, L-phenylalanine.
Partition of a Set which Contains an Infinite Arithmetic (Respectively Geometric) Progression

We prove that for any partition of a set which contains an infinite arithmetic (respectively geometric) progression into two subsets, at least one of these subsets contains an infinite number of triplets such that each triplet is an arithmetic (respectively geometric) progression.
Conformationally constrained substance P analogues: the total synthesis of a constrained peptidomimetic for the Phe7-Phe8 region.

A lactam-based peptidomimetic for the Phe7-Phe8 region of substance P has been synthesized. The synthesis used an anodic amide oxidation to selectively functionalize the C5-position of a 3-phenylproline derivative. The resulting proline derivative was coupled to a Cbz-protected phenylalanine, and an intramolecular reductive amination strategy used to convert the coupled material into a bicyclic piperazinone ring skeleton. The net result was a dipeptide building block that imbedded one of two proposed receptor bound conformations for the Phe7-Phe8 region of substance P into a bicyclic ring skeleton. The building block was then converted into a constrained substance P analogue with the use of solid-phase peptide synthesis. A similar intramolecular reductive amination strategy was used to synthesize a substance P analogue having only Phe7 constrained, and the original 3-phenylproline was converted into a substance P analogue having only Phe8 constrained. All of the analogues were examined for their ability t...
Copper, gold and nickel clusters with and without metal–metal bonds in 50 years of Fackler group chemistry

Abstract Clusters have played a strong role in the chemistry of the Fackler group for about 50 years (Fackler 1989) [1]. This paper reviews some of the chemistry we have uncovered with copper, gold and nickel which have produced several unanswered questions. Although electron-pair bonding between the metal atoms in these clusters is present only in the gold(II) compounds described, cuprophilic and aurophilic metal–metal interactions are present in the compounds described for copper and gold. In the tri-i-butyl aluminum reduced nickel catalyst system which leads to the formation of cis -polybutadiene, the role of any metal–metal interactions is unknown.
Synthesis, Structure Determination, and Reactivity of C2-Symmetrical Ethylene-Bridged ansa-Bis(DiMeBCOCp)titanium Dichlorides

The bridging of C2-symmetric 8,10-dimethyltricyclo[5.2.2.02,6]-2,5-undecadiene (DMeBCOCpH) by silicon, methylene, and ethylene was investigated. The dimethylsilyl-bridged bis(BCOCp) ligand was accessible but could not be converted to its titanium, zirconium, or niobium chloride complexes. 8,10-Dimethyl-4-(1-methylethylidene)tricyclo[5.2.2.02,6]-2,5-undecadiene (DMeBCOCp-dimethylfulvene) was formed, but did not react with cyclopentadienyl anions. A regioisomeric mixture of 1,2-bis[(1R,7R,8R,10R)-8,10-dimethyltricyclo[5.2.2.02,6]-2,5-undecadienyl]ethane [en(DMeBCOCpH)] ligands could be formed and metalated to form (+)-[ethylene-1,2-bis[η5-(1R,7R,8R,10R)-8,10-dimethyltricyclo[5.2.2.02,6]-2,5-undecadien-4-yl]]titanium dichloride [(+)-β,β-en(DMeBCOCp)2TiCl2, (+)-11] along with its α,α- and α,β-bridged regioisomeric titanocene dichlorides. (+)-11 is unique in that it is a chiral ethylene-bridged ansa-metallocene which contains only homotopic cyclopentadienyl faces. (+)-11 was characterized by X-ray crystallogra...
Transition from Actin-Driven to Water-Driven Cell Migration Depends on External Hydraulic Resistance.

Abstract Cells in vivo can reside in diverse physical and biochemical environments. For example, epithelial cells typically live in a two-dimensional (2D) environment, whereas metastatic cancer cells can move through dense three-dimensional matrices. These distinct environments impose different kinds of mechanical forces on cells and thus potentially can influence the mechanism of cell migration. For example, cell movement on 2D flat surfaces is mostly driven by forces from focal adhesion and actin polymerization, whereas in confined geometries, it can be driven by water permeation. In this work, we utilize a two-phase model of the cellular cytoplasm in which the mechanics of the cytosol and the F-actin network are treated on an equal footing. Using conservation laws and simple force balance considerations, we are able to describe the contributions of water flux, actin polymerization and flow, and focal adhesions to cell migration both on 2D surfaces and in confined spaces. The theory shows how cell migration can seamlessly transition from a focal adhesion- and actin-based mechanism on 2D surfaces to a water-based mechanism in confined geometries.
Nafion®-catalyzed microwave-assisted Ritter reaction: an atom-economic solvent-free synthesis of amides

An atom-economic solvent-free synthesis of amides by the Ritter reaction of alcohols and nitriles under microwave irradiation is reported. This green protocol is catalyzed by solid-supported Nafion®NR50 with improved efficiency and reduced waste production.
Stereodirecting Effects in the Characterization of Ylide Intermediates in Reactions of Singlet Methylene with an Allylic Ether and an Allylic Chloride

Abstract The stereodirecting effects of substrate substituents were examined in addition of 1 :CH 2 to the double bonds of 3-methoxycyclohexene ( 3a ), 3-chlorocyclohexene ( 3b ), and 3-methylcyclohexene ( 3c ) in pentane solution at temperatures from 23°C to −50°C. A preference for addition syn to the directing substituent was observed in reactions of 3a and 3b and was attributed to a reversible interaction of carbene and substituent. In the reaction with 3a this interaction was not obviously ylide formation. © 1997 Elsevier Science Ltd.
A Neural Population Mechanism for Rapid Learning

Long-term learning of language, mathematics, and motor skills likely requires cortical plasticity, but behavior often requires much faster changes, sometimes even after single errors. Here, we propose one neural mechanism to rapidly develop new motor output without altering the functional connectivity within or between cortical areas. We tested cortico-cortical models relating the activity of hundreds of neurons in the premotor (PMd) and primary motor (M1) cortices throughout adaptation to reaching movement perturbations. We found a signature of learning in the "output-null" subspace of PMd with respect to M1 reflecting the ability of premotor cortex to alter preparatory activity without directly influencing M1. The output-null subspace planning activity evolved with adaptation, yet the "output-potent" mapping that captures information sent to M1 was preserved. Our results illustrate a population-level cortical mechanism to progressively adjust the output from one brain area to its downstream structures that could be exploited for rapid behavioral adaptation.
Source Depth for Solar p-Modes

Theoretically calculated power spectra are comparable with observed solar p-mode velocity power spectra over a range of mode, degree, and frequency. The depth for the sources responsible for exciting p-modes of frequency 2.0 mHz is determined from the asymmetry of their power spectra and found to be about 800 km below the photosphere for quadrupole sources and 150 km if sources are dipole. The source depth for high-frequency oscillations greater than ~6 mHz is 180 (50) km for quadrupole (dipole) sources.
Synthesis and biological evaluation of 5‐substituted‐4‐nitroimidazole ribonucleosides

The imidazole nucleosides, 4(5)-bromo-5(4)-nitro-1-β-D-ribofuranosylimidazoles, have been prepared via glycosylation of the trimethylsilylated aglycone, 4(5)-bromo-5(4)-nitroimidazole, with tetra-O-acetyl-β-D-ribo-furanose followed by removal of the acetyl protecting groups. The 5-bromo-4-nitro-1-β-D-ribofuranosylimidazole nucleoside was acetonated to produce 5-bromo-4-nitro-1-(2,3-O-isopropylidene-β-D-ribofuranosyl)-imidazole which was cyclized to provide the corresponding anhydronucleoside 5,5′-anhydro-4-nitro-5-oxo-1-(2,3-O-isopropylidene-β-D-ribofuranosyl)imidazole. Sodium hydrosulfide treatment of 5-bromo-4-nitroimidazole nucleoside provided 5-mercapto-4-nitro-1-β-D-ribofuranosylimidazole 5-sodium salt which was alkylated with E-1,5-diiodopent-1-ene to yield 5-(E-1-iodo-1-penten-5-yl)thio-4-nitro-1-β-D-ribofuranosylimidazole. The corresponding iodine-125-labeled compound was prepared similarly using radiolabeled diiodopentene. The 5-bromo-4-nitroimidazole, 5-mercapto-4-nitroimidazole, and 5-iodopentenylthio-4-nitroimidazole nucleosides were cytotoxic to Molt-3 cells in vitro at concentrations higher than 10 μg/mL. The radiolabeled 5-iodopentenylthio-4-nitroimidazole nucleoside showed 2-fold higher uptake in a rapidly growing tumor as compared to uptake in a relatively slower growing tumor in mice.
RNAs as Proximity-Labeling Media for Identifying Nuclear Speckle Positions Relative to the Genome.

It remains challenging to identify all parts of the nuclear genome that are in proximity to nuclear speckles, due to physical separation between the nuclear speckle cores and chromatin. We hypothesized that noncoding RNAs including small nuclear RNA (snRNAs) and Malat1, which accumulate at the periphery of nuclear speckles (nsaRNA [nuclear speckle-associated RNA]), may extend to sufficient proximity to the genome. Leveraging a transcriptome-genome interaction assay (mapping of RNA-genome interactions [MARGI]), we identified clusters of nsaRNA-interacting genomic sequences (nsaPeaks). Posttranscriptional pre-mRNAs, which also accumulate to nuclear speckles, exhibited proximity to nsaPeaks but rarely to other genomic regions. Our combined DNA fluorescence in situ hybridization and immunofluorescence analysis in 182 single cells revealed a 3-fold increase in odds for nuclear speckles to localize near an nsaPeak than its neighboring genomic sequence. These data suggest a model that nsaRNAs are located in sufficient proximity to the nuclear genome and leave identifiable genomic footprints, thus revealing the parts of genome proximal to nuclear speckles.
Oxygen intercalation of two polymorphs of CuScO2

Abstract Both the 2H and 3R forms of CuScO 2 have been intercalated with oxygen to yield CuScO 2+ x , phases where x has been observed to range from 0.0 to 0.12 and 0.44 to 0.5. The position of the interstitial oxygen in the CuScO 2.5 phases was determined from powder neutron diffraction data. In both cases the interstitial oxygen resides in triangular sites in the Cu layer. However, in the 3R form the oxygen is displaced 0.3 A toward a Sc atom above or below the Cu plane. When heating the 2H form of CuScO 2 under oxygen, the oxygen initially absorbed is released at about 440 °C. The 3R form does not lose oxygen under these conditions but it does lose oxygen around 580 °C when heated in air. These are exceptionally low temperatures for the thermal reduction of Cu 2+ to Cu 1+ in an oxide system, but it is consistent with the low calculated bond valence sum of 1.7 for interstitial oxygen compared to 2.0 calculated for the network oxygen. The weak bond formed between the interstitial oxygen and Sc in 3R CuScO 2 is presumably the reason why this oxygen is more strongly held in the 3R form relative to the 2H form. On oxygen intercalation there is a 1.46% increase of the hexagonal a cell edge the 2H form and a 1.61% increase for the 3R form. The c cell edge expands by 0.23% on oxidation of the 2H form, but contracts by 0.30% on oxidation of the 3R form. This contraction of c and greater expansion for a for the 3R form can be attributed to the weak bond formed between Sc and the interstitial oxygen. Most synthesis routes to CuScO 2 give a mixture of the 2H and 3R forms, and this mixing can extend to the atomic level in the form of stacking faults.
Remarkably complex and unpredictable cyclization and rearrangement reactions of cations derived from unsaturated oxiranes

Abstract Lewis-acid catalyzed reactions of unsaturated epoxides 1 and 2 afford the unprecedented products 3 and 5, respectively. Mechanistic pathways for these reactions are presented (Schemes 2 and 4) along with a more fundamental analysis.
The cognitive dissonance between the rule of law and rural realities: Reading Gillian Hadfield’s Rules for a Flat World in the context of rural identity and politics

Rural communities – as well as other marginalized communities – see their access to legal infrastructure declining, so much so that they feel disconnected from the rule of law. Current complex law and legal infrastructure focus on big “I” innovation, which is hyper-transactional and benefits the few. Rural communities, and others, would find law and legal infrastructure more relevant if they focused more on small “i” innovation, which centers on negotiating real, societal relationships.
New Bis(Imino)Pyridine Complexes of Iron(II) and Iron(III), and Their Catalytic­ Activity in the Mukaiyama Aldol Reaction

New iron(II) and iron(III) complexes bearing bis(imino)pyridine ligands were synthesized and successfully applied to the Mukaiyama aldol reaction. The two complexes [FeCl2 L] (L = bis(imino)pyridine ligand, 55% isolated yield) and [LFe(μCl)3FeCl3] (76%) were obtained employing FeCl2 and FeCl3 iron sources, respectively, and characterized by elemental analyses, mass spectrometry, IR spectroscopy and, one example, by X-ray diffraction. The two new iron complexes were subsequently employed as catalysts in the Mukaiyama aldol reaction after abstraction of two chlorides by AgSbF6 to obtain the aldol products in 43% to virtually quantitative yield (CH2Cl2 solvent, room temperature, 3.5 to 16 h reaction time). The impact of the oxidation state of the iron center on the reaction rate and the diastereomeric ratios of the products was investigated.
N-O diheterocyclic nucleosides: Synthesis of 2′-n-methyl-3′-hydroxymethyl-1′,2′-isoxazolidinylthymidine

Abstract Isoxazolidine thymidine derivatives were synthesized by the condensation of silylated thymine with isoxazolidinyl acetate prepared by the Michael addition of an α,β-unsaturated ester with N-methylhydroxyamine followed by DIBAL reduction and acetate production.
Cyclizations in the Addition of Alkylmercury Halides to Dienes and Enynes

Photostimulated additions of tert-butylmercury halides to 1,6-dienes and enynes, including (CH2CHCH2)2X with X = CH2, C(COEt)2, O, or NCH2CHCH2, form the primary alkylmercury halides resulting from 5-exo-cyclizations of the adduct radicals, t-BuCH2CH•CH2XCH2CHCH2. The kinetic chain lengths of these free-radical processes are low and in the range of 3−7 at 35 °C in Me2SO. 5-Exo-cyclizations with kinetic chain lengths of ∼100 are observed in the photostimulated addition of t-BuHgI to CH2CHP(O)(OR)OCH2CHCH2 (R = H or allyl), CH2CHC(O)N(R)CH2CHCH2 (R = Me, Ph, or CH2CHCH2), or CH2CHC(O)OC(Me)2CHCH2. The radicals t-BuCH2CH•C(O)C(Me)2(CH2)nCHCH2 cyclize mainly in the 6-endo mode for n = 1 and more rapidly in the 6-exo mode for n = 2, while the radicals t-BuCH2CH•C(O)OC(Me)2(CH2)nCHCH2 cyclize only in the exo mode for n = 0 or 1 but with a faster rate for 5-exo-cyclization. Gem-dimethyl substitution adjacent to the alkyl oxygen accelerates the 5-exo-cyclization of the ester radicals because of rotamer population...
Subjective Questions and Answers for a Mathematics Instructor of Higher Education

This article of mathematical education reflects author's experience with job applications and teaching methods and procedures to employ in the American Higher Education. It is organized as a standard questionnaire.
Rearrangement of the trans-Tricyclo[4.2.0.01,3]oct-4-enyl Skeleton

Abstract The acetolysis of a tosylate with a novel tricyclic skeleton was examined. Two major products (a tosylate and an acetate) are formed and both are the result of a skeletal rearrangement. A mechanism to account for the observed products is proposed and preliminary kinetic data are reported.
A comparative study of endoderm differentiation in humans and chimpanzees

There is substantial interest in the evolutionary forces that shaped the regulatory framework in early human development. Progress in this area has been slow because it is difficult to obtain relevant biological samples. Induced pluripotent stem cells (iPSCs) may provide the ability to establish in vitro models of early human and non-human primate developmental stages. Using matched iPSC panels from humans and chimpanzees, we comparatively characterize gene regulatory changes through a four-day time course differentiation of iPSCs into primary streak, endoderm progenitors, and definitive endoderm. As might be expected, we find that differentiation stage is the major driver of variation in gene expression levels, followed by species. We identify thousands of differentially expressed genes between humans and chimpanzees in each differentiation stage. Yet, when we consider gene-specific dynamic regulatory trajectories throughout the time course, we find that at least 75% of genes, including nearly all known endoderm developmental markers, have similar trajectories in the two species. Interestingly, we observe a marked reduction of both intra- and inter-species variation in gene expression levels in primitive streak samples compared to the iPSCs, with a recovery of regulatory variation in endoderm progenitors. The reduction of variation in gene expression levels at a specific developmental stage, paired with overall high degree of conservation of temporal gene regulation, is consistent with the dynamics of a conserved developmental process.
Enantioselective Synthesis of Salmeterol via Asymmetric Borane Reduction.

Abstract Enantioselective syntheses of both enantiomers of salmeterol are accomplished using asymmetric borane reductions with chiral oxazaborolidines as catalysts.
Vilsmeier methodology for the synthesis of 3-(2-N-phthaloylacyl)indole derivatives, and its application to the synthesis of the GCDEF rings of diazonamide

Abstract The synthesis of the GCDEF fragment of diazonamide was achieved using a modified Vilsmeier procedure that allows ready access to 3-(2- N -phthaloylacyl)indole derivatives.
Thermochemical insights into rapid solid-state reaction synthesis of β-sialon

Sialons (Si−Al−O−N) are useful as engineering components because they combine the toughness of silicon nitride with phase stability. Competing reactions occur during conventional processing, making...
A Diastereoselective Intermolecular Heck Reaction of 1,3-Dioxepins

A highly diastereoselective intermolecular Heck reaction of 1,3-dioxepins is reported. Substitution at both the 2- and 4-positions of the dioxepin directs the Pd coordination and subsequent olefin insertion to provide the trans-disubstituted adduct in good yield and high diastereoselectivity. Chemoselective Heck reaction occurs at the dioxepin alkene in the presence of other olefinic functional groups. A labeling study has been conducted which suggests that the reaction is under kinetic control.
Conversion of α,β-unsaturated ketones into α-hydroxy ketones using an MnIII catalyst, phenylsilane and dioxygen: acceleration of conjugate hydride reduction by dioxygen

Abstract Treatment of a variety of α,β-unsaturated ketones with Mn(dpm)3 (3 mol%)/PhSiH3 (1.3 equiv.)/isopropyl alcohol/O2, followed by reductive work-up with P(OEt)3 resulted in the formation of α-hydroxyketones.
The Effect of Instruction Differentiation in Preventive Classroom Management Strategies on Early Childhood and Elementary Preservice Teachers’ Selected Behaviors in a Music Integration Course:

The purpose of this pilot study was to investigate the effect of instruction differentiation in preventive classroom management strategies on preservice teachers’ selected behaviors. Results indica...
Stillbirths: how should its rate be reported, its disability-adjusted-life-years (DALY), and stillbirths adjusted life expectancy.

A 2016 study standardized the definition of stillbirths. It estimated the rate as a proportion of total births. A 2015 paper addressed the problem of disability-adjusted life-years (DALY) for stillbirths. There has been no adjustment of life expectancy at birth to account for stillbirths. We follow mathematical and computational methods, use algebra to derive relationships, and large databases. We express the rate as a proportion of live births and use this rate to adjust life expectancy at birth for stillbirths. We then use the difference between the traditional life expectancy and stillbirths adjusted life expectancy (SALE) to obtain DALY for stillbirths for 194 countries, the Millennium Development Goal regions, and income groups. We show defining stillbirths’ rate as a proportion of live births enhances stillbirths’ importance, especially in poorer countries; negates some of its under-statement vis-a-vis neonatal mortality rate, accentuates its decrease; and permits inference about relative magnitudes of stillbirths and neonatal mortality from the two rates. Using it, we derive stillbirths adjusted life expectancy, and suggest it reflects a more complete and accurate measure of comparative life expectancies of different countries. Its difference from the traditional life expectancy is used to measure DALY for stillbirths that totals 165.3 million years worldwide. Stillbirths almost equals neonatal mortality yet have not received almost equal attention. We hope highlighting them and adjusting life expectancy for it will spur health interventions so that grand convergence of health outcomes in different countries can be more rapidly achieved. We also believe SALE is a more complete and accurate measure of comparative life expectancies.
Multiplicative groups of fields and hereditarily irreducible polynomials

Abstract In this paper we explore the concept of good heredity for fields from a group theoretic perspective. Extending results from [8] , we show that several natural families of fields are of good heredity, and some others are not. We also construct several examples to show that various wishful thinking expectations are not true.
Energy Efficiency of Hybrid-ARQ Under Statistical Queuing Constraints

In this paper, energy efficiency of hybrid automatic repeat request (HARQ) schemes with statistical queuing constraints is studied for both constant-rate and random Markov arrivals by characterizing the minimum energy per bit and wideband slope. In particular, two queuing models are considered. Specifically, when outage occurs, the transmitter keeps the packet, lowers its priority, and attempts to retransmit it later in the first queue model, while the packet is discarded and removed from the buffer in the second queue model. For both models, energy efficiency is investigated when outage constraints, statistical queuing constraints, and deadline constraints are imposed. The deadline constraint provides a limitation on the number of retransmissions or equivalently the number of HARQ rounds. Under these assumptions, closed-form expressions are obtained for the minimum energy per bit and wideband slope for HARQ with chase combining, and comparisons among different arrival models are made. For instance, it is shown that stricter queuing constraints and more bursty sources degrade the energy efficiency by lowering the wideband slope. In the numerical results, analytical characterizations are verified through simulations. Moreover, the impact of source variations/burstiness, deadline constraints, outage probability, and queuing constraints on the energy efficiency is analyzed.
Radiometric actuators for spacecraft attitude control

CubeSats and small satellites are emerging as low-cost tools to perform astronomy, exoplanet searches and earth observation. These satellites can be dedicated to pointing at targets for weeks or months at a time. This is typically not possible on larger missions where usage is shared. Current satellites use reaction wheels and where possible magneto-torquers to control attitude. However, these actuators can induce jitter due to various sources. In this work, we introduce a new class of actuators that exploit radiometric forces induced by gasses on surface with a thermal gradient. Our work shows that a CubeSat or small spacecraft mounted with radiometric actuators can achieve precise pointing of few arc-seconds or less and avoid the jitter problem. The actuator is entirely solid-state, containing no moving mechanical components. This ensures high-reliability and long-life in space. A preliminary design for these actuators is proposed, followed by feasibility analysis of the actuator performance.
Paley–Wiener theorem for line bundles over compact symmetric spaces and new estimates for the Heckman–Opdam hypergeometric functions

Paley–Wiener type theorems describe the image of a given space of functions, often compactly supported functions, under an integral transform, usually a Fourier transform on a group or homogeneous space. In this article we proved a Paley–Wiener theorem for smooth sections f of homogeneous line bundles on a compact Riemannian symmetric space U/K. It characterizes f with small support in terms of holomorphic extendability and exponential growth of their χ‐spherical Fourier transforms, where χ is a character of K. An important tool in our proof is a generalization of Opdam's estimate for the hypergeometric functions associated to multiplicity functions that are not necessarily positive. At the same time the radius of the domain where this estimate is valid is increased. This is done in an appendix.
Structural results and explicit solution for two-player LQG systems on a finite time horizon

It is well-known that linear dynamical systems with Gaussian noise and quadratic cost (LQG) satisfy a separation principle. Finding the optimal controller amounts to solving separate dual problems; one for control and one for estimation. For the discrete-time finite-horizon case, each problem is a simple forward or backward recursion. In this paper, we consider a generalization of the LQG problem with two controllers and a partially nested information structure. Each controller is responsible for one of two system inputs, but has access to different subsets of the available measurements. Our paper has three main contributions. First, we prove a fundamental structural result: sufficient statistics for the controllers can be expressed as conditional means of the global state. Second, we give explicit state-space formulae for the optimal controller. These formulae are reminiscent of the classical LQG solution with dual forward and backward recursions, but with the important difference that they are intricately coupled. Lastly, we show how these recursions can be solved efficiently, with computational complexity comparable to that of the centralized problem.
Finite groups with a prescribed number of cyclic subgroups

Marius Tarnauceanu described the finite groups G having |G|−1 cyclic subgroups. We describe the finite groups G having |G|−Δ cyclic subgroups for Δ=2,3,4, and 5.
Coordinated Exploration in Concurrent Reinforcement Learning

We consider a team of reinforcement learning agents that concurrently learn to operate in a common environment. We identify three properties - adaptivity, commitment, and diversity - which are necessary for efficient coordinated exploration and demonstrate that straightforward extensions to single-agent optimistic and posterior sampling approaches fail to satisfy them. As an alternative, we propose seed sampling, which extends posterior sampling in a manner that meets these requirements. Simulation results investigate how per-agent regret decreases as the number of agents grows, establishing substantial advantages of seed sampling over alternative exploration schemes.
Recurrent Segmentation for Variable Computational Budgets

State-of-the-art systems for semantic image segmentation use feed-forward pipelines with fixed computational costs. Building an image segmentation system that works across a range of computational budgets is challenging and time-intensive as new architectures must be designed and trained for every computational setting. To address this problem we develop a recurrent neural network that successively improves prediction quality with each iteration. Importantly, the RNN may be deployed across a range of computational budgets by merely running the model for a variable number of iterations. We find that this architecture is uniquely suited for efficiently segmenting videos. By exploiting the segmentation of past frames, the RNN can perform video segmentation at similar quality but reduced computational cost compared to state-of-the-art image segmentation methods. When applied to static images in the PASCAL VOC 2012 and Cityscapes segmentation datasets, the RNN traces out a speed-accuracy curve that saturates near the performance of state-of-the-art segmentation methods.
Thrifty approximations of convex bodies by polytopes

Given a convex body C in R^d containing the origin in its interior and a real number tau > 1 we seek to construct a polytope P in C with as few vertices as possible such that C in tau P. Our construction is nearly optimal for a wide range of d and tau. In particular, we prove that if C=-C then for any 1>epsilon>0 and tau=1+epsilon one can choose P having roughly epsilon^{-d/2} vertices and for tau=sqrt{epsilon d} one can choose P having roughly d^{1/epsilon} vertices. Similarly, we prove that if C in R^d is a convex body such that -C in mu C for some mu > 1 then one can choose P having roughly ((mu+1)/(tau-1))^{d/2} vertices provided (tau-1)/(mu+1) << 1.
Hydrodynamic limit with geometric correction of stationary Boltzmann equation

Abstract We consider the hydrodynamic limit of a stationary Boltzmann equation in a unit plate with in-flow boundary. The classical theory claims that the solution can be approximated by the sum of interior solution which satisfies steady incompressible Navier–Stokes–Fourier system, and boundary layer derived from Milne problem. In this paper, we construct counterexamples to disprove such formulation in L ∞ both for its proof and result. Also, we show the hydrodynamic limit with a different boundary layer expansion with geometric correction.
Accelerate stochastic subgradient method by leveraging local growth condition

In this paper, a new theory is developed for first-order stochastic convex optimization, showing that the global convergence rate is sufficiently quantified by a local growth rate of the objective ...
THE BETTI NUMBERS OF REGULAR HESSENBERG VARIETIES ARE PALINDROMIC

Recently Brosnan and Chow have proven a conjecture of Shareshian and Wachs describing a representation of the symmetric group on the cohomology of regular semisimple Hessenberg varieties for GL n (ℂ). A key component of their argument is that the Betti numbers of regular Hessenberg varieties for GL n (ℂ) are palindromic. In this paper, we extend this result to all complex reductive algebraic groups, proving that the Betti numbers of regular Hessenberg varieties are palindromic.
A Design Principle for Actuation of Nematic Glass Sheets

A continuum mechanical framework is developed for determining (a) the class of stress-free deformed shapes and corresponding director distributions on the undeformed configuration of a nematic glass membrane that has a prescribed spontaneous stretch field and (b) the class of undeformed configurations and corresponding director distributions on it resulting in a stress-free given deformed shape of a nematic glass sheet with a prescribed spontaneous stretch field. The proposed solution rests on an understanding of how the Lagrangian dyad of a deformation of a membrane maps into the Eulerian dyad in three dimensional ambient space. Interesting connections between these practical questions of design and the mathematical theory of isometric embeddings of manifolds, deformations between two prescribed Riemannian manifolds, and the slip-line theory of plasticity are pointed out.
Monocular SLAM Supported Object Recognition

In this work, we develop a monocular SLAM-aware object recognition system that is able to achieve considerably stronger recognition performance, as compared to classical object recognition systems that function on a frame-by-frame basis. By incorporating several key ideas including multi-view object proposals and efficient feature encoding methods, our proposed system is able to detect and robustly recognize objects in its environment using a single RGB camera in near-constant time. Through experiments, we illustrate the utility of using such a system to effectively detect and recognize objects, incorporating multiple object viewpoint detections into a unified prediction hypothesis. The performance of the proposed recognition system is evaluated on the UW RGB-D Dataset, showing strong recognition performance and scalable run-time performance compared to current state-of-the-art recognition systems.
Combining trajectory optimization, supervised machine learning, and model structure for mitigating the curse of dimensionality in the control of bipedal robots:

To overcome the obstructions imposed by high-dimensional bipedal models, we embed a stable walking motion in an attractive low-dimensional surface of the system’s state space. The process begins wi...
Approximating the permanent with fractional belief propagation

We discuss schemes for exact and approximate computations of permanents, and compare them with each other. Specifically, we analyze the belief propagation (BP) approach and its fractional belief propagation (FBP) generalization for computing the permanent of a non-negative matrix. Known bounds and Conjectures are verified in experiments, and some new theoretical relations, bounds and Conjectures are proposed. The fractional free energy (FFE) function is parameterized by a scalar parameter γ ∈ [-1;1], where γ = -1 corresponds to the BP limit and γ = 1 corresponds to the exclusion principle (but ignoring perfect matching constraints) mean-field (MF) limit. FFE shows monotonicity and continuity with respect to γ. For every non-negative matrix, we define its special value γ* ∈ [-1;0] to be the γ for which the minimum of the γ-parameterized FFE function is equal to the permanent of the matrix, where the lower and upper bounds of the γ-interval corresponds to respective bounds for the permanent. Our experimental analysis suggests that the distribution of γ* varies for different ensembles but γ* always lies within the [-1;-1/2] interval. Moreover, for all ensembles considered, the behavior of γ* is highly distinctive, offering an empirical practical guidance for estimating permanents of non-negative matrices via the FFE approach.
Unsupervised learning of noisy-or Bayesian networks

This paper considers the problem of learning the parameters in Bayesian networks of discrete variables with known structure and hidden variables. Previous approaches in these settings typically use expectation maximization; when the network has high treewidth, the required expectations might be approximated using Monte Carlo or variational methods. We show how to avoid inference altogether during learning by giving a polynomial-time algorithm based on the method-of-moments, building upon recent work on learning discrete-valued mixture models. In particular, we show how to learn the parameters for a family of bipartite noisy-or Bayesian networks. In our experimental results, we demonstrate an application of our algorithm to learning QMR-DT, a large Bayesian network used for medical diagnosis. We show that it is possible to fully learn the parameters of QMR-DT even when only the findings are observed in the training data (ground truth diseases unknown).
SybilBlind: Detecting Fake Users in Online Social Networks Without Manual Labels

Detecting fake users (also called Sybils) in online social networks is a basic security research problem. State-of-the-art approaches rely on a large amount of manually labeled users as a training set. These approaches suffer from three key limitations: (1) it is time-consuming and costly to manually label a large training set, (2) they cannot detect new Sybils in a timely fashion, and (3) they are vulnerable to Sybil attacks that leverage information of the training set. In this work, we propose SybilBlind, a structure-based Sybil detection framework that does not rely on a manually labeled training set. SybilBlind works under the same threat model as state-of-the-art structure-based methods. We demonstrate the effectiveness of SybilBlind using (1) a social network with synthetic Sybils and (2) two Twitter datasets with real Sybils. For instance, SybilBlind achieves an AUC of 0.98 on a Twitter dataset.
Detecting community structures in Hi-C genomic data

Community detection (CD) algorithms are applied to Hi-C data to discover new communities of loci in the 3D conformation of human and mouse DNA. We find that CD has some distinct advantages over pre-existing methods: (1) it is capable of finding a variable number of communities, (2) it can detect communities of DNA loci either adjacent or distant in the 1D sequence, and (3) it allows us to obtain a principled value of k, the number of communities present. Forcing k = 2, our method recovers earlier findings of Lieberman-Aiden, et al. (2009), but letting k be a parameter, our method obtains as optimal value k* = 6, discovering new candidate communities. In addition to discovering large communities that partition entire chromosomes, we also show that CD can detect small-scale topologically associating domains (TADs) such as those found in Dixon, et al. (2012). CD thus provides a natural and flexible statistical framework for understanding the folding structure of DNA at multiple scales in Hi-C data.
Thinking Outside the Pool: Active Training Image Creation for Relative Attributes

Current wisdom suggests more labeled image data is always better, and obtaining labels is the bottleneck. Yet curating a pool of sufficiently diverse and informative images is itself a challenge. In particular, training image curation is problematic for fine-grained attributes, where the subtle visual differences of interest may be rare within traditional image sources. We propose an active image generation approach to address this issue. The main idea is to jointly learn the attribute ranking task while also learning to generate novel realistic image samples that will benefit that task. We introduce an end-to-end framework that dynamically "imagines" image pairs that would confuse the current model, presents them to human annotators for labeling, then improves the predictive model with the new examples. On two datasets, we show that by thinking outside the pool of real images, our approach gains generalization accuracy on challenging fine-grained attribute comparisons.
Towards reliable online clickbait video detection: A content-agnostic approach

Abstract Online video sharing platforms (e.g., YouTube, Vimeo) have become an increasingly popular paradigm for people to consume video contents. Clickbait video, whose content clearly deviates from its title/thumbnail, has emerged as a critical problem on online video sharing platforms. Current clickbait detection solutions that mainly focus on analyzing the text of the title, the image of the thumbnail, or the content of the video are shown to be suboptimal in detecting the online clickbait videos. In this paper, we develop a novel content-agnostic scheme, Online Video Clickbait Protector (OVCP), to effectively detect clickbait videos by exploring the comments from the audience who watched the video. Different from existing solutions, OVCP does not directly analyze the content of the video and its pre-click information (e.g., title and thumbnail). Therefore, it is robust against sophisticated content creators who often generate clickbait videos that can bypass the current clickbait detectors. We evaluate OVCP with a real-world dataset collected from YouTube. Experimental results demonstrate that OVCP is effective in identifying clickbait videos and significantly outperforms both state-of-the-art baseline models and human annotators.